1.
Extremophile
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An extremophile is an organism that thrives in physically or geochemically extreme conditions that are detrimental to most life on Earth. In contrast, organisms that live in moderate environments may be termed mesophiles or neutrophiles. Some scientists even concluded that life may have begun on Earth in hydrothermal vents far under the oceans surface. According to astrophysicist Dr. Steinn Sigurdsson, There are viable bacterial spores that have found that are 40 million years old on Earth—and we know theyre very hardened to radiation. On 6 February 2013, scientists reported that bacteria were found living in the cold, on 17 March 2013, researchers reported data that suggested microbial life forms thrive in the Mariana Trench, the deepest spot on the Earth. Other researchers reported related studies that microbes thrive inside rocks up to 1900 feet below the sea floor under 8500 feet of ocean off the coast of the northwestern United States. According to one of the researchers, You can find microbes everywhere—theyre extremely adaptable to conditions, the domain Archaea contains renowned examples, but extremophiles are present in numerous and diverse genetic lineages of bacteria and archaeans. Furthermore, it is erroneous to use the term extremophile to encompass all archaeans, neither are all extremophiles unicellular, protostome animals found in similar environments include the Pompeii worm, the psychrophilic Grylloblattidae and Antarctic krill. Their chances of dying increase the longer they are exposed to the extreme environment, There are many classes of extremophiles that range all around the globe, each corresponding to the way its environmental niche differs from mesophilic conditions. Many extremophiles fall under multiple categories and are classified as polyextremophiles, for example, organisms living inside hot rocks deep under Earths surface are thermophilic and barophilic such as Thermococcus barophilus. A polyextremophile living at the summit of a mountain in the Atacama Desert might be a radioresistant xerophile, a psychrophile, polyextremophiles are well known for their ability to tolerate both high and low pH levels. Two sub-types exist, facultative anaerobe and obligate anaerobe, in it, microbial ecologists, astronomers, planetary scientists, geochemists, philosophers, and explorers cooperate constructively to guide the search for life on other planets. Astrobiologists are particularly interested in studying extremophiles, as many organisms of this type are capable of surviving in environments similar to known to exist on other planets. For example, Mars may have regions in its deep subsurface permafrost that could harbor endolith communities, the subsurface water ocean of Jupiters moon Europa may harbor life, especially at hypothesized hydrothermal vents at the ocean floor. Recent research carried out on extremophiles in Japan involved a variety of bacteria including Escherichia coli, the bacteria were cultivated while being rotated in an ultracentrifuge at high speeds corresponding to 403,627 g. Analysis showed that the size of prokaryotic cells is essential for successful growth under hypergravity. The research has implications on the feasibility of panspermia, on 19 May 2014, scientists announced that numerous microbes, like Tersicoccus phoenicis, may be resistant to methods usually used in spacecraft assembly clean rooms. Its not currently known if such resistant microbes could have withstood space travel and are present on the Curiosity rover now on the planet Mars, on 20 August 2014, scientists confirmed the existence of microorganisms living half a mile below the ice of Antarctica
2.
Organism
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In biology, an organism is any contiguous living system, such as an animal, plant, fungus, protist, archaeon, or bacterium. All known types of organisms are capable of some degree of response to stimuli, reproduction, growth and development and homeostasis. An organism consists of one or more cells, when it has one cell it is known as an organism. Most unicellular organisms are of microscopic scale and are thus described as microorganisms. Humans are multicellular organisms composed of trillions of cells grouped into specialized tissues. An organism may be either a prokaryote or a eukaryote, prokaryotes are represented by two separate domains—bacteria and archaea. Eukaryotic organisms are characterized by the presence of a cell nucleus. Fungi, animals and plants are examples of kingdoms of organisms within the eukaryotes, estimates on the number of Earths current species range from 10 million to 14 million, of which only about 1.2 million have been documented. More than 99% of all species, amounting to five billion species. In 2016, a set of 355 genes from the last universal ancestor of all living organisms living was identified. The term organism first appeared in the English language in 1703 and it is directly related to the term organization. There is a tradition of defining organisms as self-organizing beings. An organism may be defined as an assembly of molecules functioning as a more or less stable whole that exhibits the properties of life. Dictionary definitions can be broad, using such as any living structure, such as a plant, animal, fungus or bacterium, capable of growth. Many definitions exclude viruses and possible man-made non-organic life forms, as viruses are dependent on the machinery of a host cell for reproduction. A superorganism is an organism consisting of individuals working together as a single functional or social unit. There has been controversy about the best way to define the organism, several contributions are responses to the suggestion that the category of organism may well not be adequate in biology. Viruses are not typically considered to be organisms because they are incapable of autonomous reproduction and this controversy is problematic because some cellular organisms are also incapable of independent survival and live as obligatory intracellular parasites
3.
Cell growth
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The term cell growth is used in the contexts of biological cell development and cell division. When used in the context of cell division, it refers to growth of cell populations, when used in the context of cell development, the term refers to increase in cytoplasmic and organelle volume, as well as increase in genetic material following the replication during S phase. Cell populations go through a type of exponential growth called doubling. Thus, each generation of cells should be twice as numerous as the previous generation, however, the number of generations only gives a maximum figure as not all cells survive in each generation. Cell size is variable among organisms, with some algae such as Caulerpa taxifolia being a single cell several meters in length. Plant cells are larger than animal cells, and protists such as Paramecium can be 330 μm long. How these cells decide how big they should be before dividing is an open question, chemical gradients are known to be partly responsible, and it is hypothesized that mechanical stress detection by cytoskeletal structures is involved. Work on the topic generally requires an organism whose cell cycle is well-characterized, the relationship between cell size and cell division has been extensively studied in yeast. For some cells, there is a mechanism by which division is not initiated until a cell has reached a certain size. If the nutrient supply is restricted, and the rate of increase in size is slowed. Yeast cell-size mutants were isolated that begin cell division reaching a normal/regular size. Wee1 protein is a kinase that normally phosphorylates the Cdc2 cell cycle regulatory protein. Cdc2 drives entry into mitosis by phosphorylating a range of targets. This covalent modification of the structure of Cdc2 inhibits the enzymatic activity of Cdc2. Wee1 acts to keep Cdc2 inactive during early G2 when cells are still small, when cells have reached sufficient size during G2, the phosphatase Cdc25 removes the inhibitory phosphorylation, and thus activates Cdc2 to allow mitotic entry. A balance of Wee1 and Cdc25 activity with changes in size is coordinated by the mitotic entry control system. It has been shown in Wee1 mutants, cells with weakened Wee1 activity, thus, mitosis occurs before the yeast reach their normal size. This suggests that cell division may be regulated in part by dilution of Wee1 protein in cells as they grow larger, the protein kinase Cdr2 and the Cdr2-related kinase Cdr1 are localized to a band of cortical nodes in the middle of interphase cells
4.
Reproduction
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Reproduction is the biological process by which new individual organisms – offspring – are produced from their parents. Reproduction is a feature of all known life, each individual organism exists as the result of reproduction. There are two forms of reproduction, asexual and sexual, in asexual reproduction, an organism can reproduce without the involvement of another organism. Asexual reproduction is not limited to single-celled organisms, the cloning of an organism is a form of asexual reproduction. By asexual reproduction, an organism creates a similar or identical copy of itself. The evolution of reproduction is a major puzzle for biologists. The two-fold cost of reproduction is that only 50% of organisms reproduce. This produces offspring organisms whose genetic characteristics are derived from those of the two parental organisms, Asexual reproduction is a process by which organisms create genetically similar or identical copies of themselves without the contribution of genetic material from another organism. Bacteria divide asexually via binary fission, viruses take control of host cells to produce more viruses, Hydras and these organisms often do not possess different sexes, and they are capable of splitting themselves into two or more copies of themselves. Most plants have the ability to reproduce asexually and the ant species Mycocepurus smithii is thought to reproduce entirely by asexual means, some species that are capable of reproducing asexually, like hydra, yeast and jellyfish, may also reproduce sexually. For instance, most plants are capable of vegetative reproduction—reproduction without seeds or spores—but can also reproduce sexually, likewise, bacteria may exchange genetic information by conjugation. Other ways of asexual reproduction include parthenogenesis, fragmentation and spore formation that involves only mitosis, parthenogenesis is the growth and development of embryo or seed without fertilization by a male. Parthenogenesis occurs naturally in some species, including plants, invertebrates. It is sometimes used to describe reproduction modes in hermaphroditic species which can self-fertilize. Sexual reproduction is a process that creates a new organism by combining the genetic material of two organisms in a process that starts with meiosis, a specialized type of cell division. Each of two parent organisms contributes half of the genetic makeup by creating haploid gametes. Most organisms form two different types of gametes, in these anisogamous species, the two sexes are referred to as male and female. In isogamous species, the gametes are similar or identical in form, for example, in the green alga, Chlamydomonas reinhardtii, there are so-called plus and minus gametes
5.
Thermophile
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A thermophile is an organism—a type of extremophile—that thrives at relatively high temperatures, between 41 and 122 °C. Thermophilic eubacteria are suggested to have been among the earliest bacteria, unlike other types of bacteria, thermophiles can survive at much hotter temperatures, whereas other bacteria would be damaged and sometimes killed if exposed to the same temperatures. As a prerequisite for their survival, thermophiles contain enzymes that can function at high temperatures, some of these enzymes are used in molecular biology, and in washing agents. Thermophile is derived from the Greek, θερμότητα, meaning heat, thermophiles are classified into 1. obligate and 2. Facultative 3. hyper thermophiles, Obligate thermophiles require such high temperatures for growth, whereas Facultative thermophiles can thrive at high temperatures, hyperthermophiles are particularly extreme thermophiles for which the optimal temperatures are above 80 °C. Bacteria within the Alicyclobacillus genus are acidophilic thermophiles, which can cause contamination in fruit juice drinks. Thermophiles, meaning heat-loving, are organisms with a growth temperature of 50 °C or more, a maximum of up to 70 °C or more, and a minimum of about 40 °C. Some extreme thermophiles require a high temperature for growth. Their membranes and proteins are stable at these extremely high temperatures. Thus, many important biotechnological processes use thermophilic enzymes because of their ability to withstand intense heat, many of the hyperthermophiles Archea require elemental sulfur for growth. Some are anaerobes that use the sulfur instead of oxygen as an electron acceptor during cellular respiration, some are lithotrophs that oxidize sulfur to sulfuric acid as an energy source, thus requiring the microorganism to be adapted to very low pH. These organisms are inhabitants of hot, sulfur-rich environments usually associated with volcanism, such as hot springs, geysers, in these places, especially in Yellowstone National Park, zonation of microorganisms according to their temperature optima occurs. Often, these organisms are colored, due to the presence of photosynthetic pigments, thermophiles can be discriminated from mesophiles from genomic features. Sulfolobus solfataricus and Sulfolobus acidocaldarius are hyperthermophilic archaea, when these organisms are exposed to the DNA damaging agents UV irradiation, bleomycin or mitomycin C, species-specific cellular aggregation is induced. In S. acidocaldarius, UV-induced cellular aggregation mediates chromosomal marker exchange with high frequency, recombination rates exceed those of uninduced cultures by up to three orders of magnitude. Van Wolferen et al. in discussing DNA exchange in the hyperthermophiles under extreme conditions and they suggested that this process is crucial under DNA damaging conditions such as high temperature. Hyperthermophile Mesophile Psychrophile Anaerobic digestion Archaea Sulfolobus Thermoprotei, Extreme Thermophile
6.
Bacteria
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Bacteria constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a number of shapes, ranging from spheres to rods, Bacteria were among the first life forms to appear on Earth, and are present in most of its habitats. Bacteria inhabit soil, water, acidic hot springs, radioactive waste, Bacteria also live in symbiotic and parasitic relationships with plants and animals. Most bacteria have not been characterised, and only half of the bacterial phyla have species that can be grown in the laboratory. The study of bacteria is known as bacteriology, a branch of microbiology, There are typically 40 million bacterial cells in a gram of soil and a million bacterial cells in a millilitre of fresh water. There are approximately 5×1030 bacteria on Earth, forming a biomass which exceeds that of all plants, Bacteria are vital in many stages of the nutrient cycle by recycling nutrients such as the fixation of nitrogen from the atmosphere. The nutrient cycle includes the decomposition of bodies and bacteria are responsible for the putrefaction stage in this process. In March 2013, data reported by researchers in October 2012, was published and it was suggested that bacteria thrive in the Mariana Trench, which with a depth of up to 11 kilometres is the deepest known part of the oceans. Other researchers reported related studies that microbes thrive inside rocks up to 580 metres below the sea floor under 2.6 kilometres of ocean off the coast of the northwestern United States. According to one of the researchers, You can find microbes everywhere—theyre extremely adaptable to conditions, the vast majority of the bacteria in the body are rendered harmless by the protective effects of the immune system, though many are beneficial particularly in the gut flora. However several species of bacteria are pathogenic and cause diseases, including cholera, syphilis, anthrax, leprosy. The most common fatal diseases are respiratory infections, with tuberculosis alone killing about 2 million people per year. In developed countries, antibiotics are used to treat infections and are also used in farming, making antibiotic resistance a growing problem. Once regarded as constituting the class Schizomycetes, bacteria are now classified as prokaryotes. Unlike cells of animals and other eukaryotes, bacterial cells do not contain a nucleus and these evolutionary domains are called Bacteria and Archaea. The ancestors of modern bacteria were unicellular microorganisms that were the first forms of life to appear on Earth, for about 3 billion years, most organisms were microscopic, and bacteria and archaea were the dominant forms of life. In 2008, fossils of macroorganisms were discovered and named as the Francevillian biota, however, gene sequences can be used to reconstruct the bacterial phylogeny, and these studies indicate that bacteria diverged first from the archaeal/eukaryotic lineage. Bacteria were also involved in the second great evolutionary divergence, that of the archaea, here, eukaryotes resulted from the entering of ancient bacteria into endosymbiotic associations with the ancestors of eukaryotic cells, which were themselves possibly related to the Archaea
7.
Archaea
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The Archaea constitute a domain and kingdom of single-celled microorganisms. These microbes are prokaryotes, meaning that they have no cell nucleus or any other membrane-bound organelles in their cells, Archaea were initially classified as bacteria, receiving the name archaebacteria, but this classification is outdated. Archaeal cells have unique properties separating them from the two domains of life, Bacteria and Eukaryota. The Archaea are further divided into multiple recognized phyla, classification is difficult because the majority have not been isolated in the laboratory and have only been detected by analysis of their nucleic acids in samples from their environment. Archaea and bacteria are generally similar in size and shape, although a few archaea have very strange shapes, such as the flat, other aspects of archaeal biochemistry are unique, such as their reliance on ether lipids in their cell membranes, including archaeols. Archaea use more energy sources than eukaryotes, these range from organic compounds, such as sugars, to ammonia, metal ions or even hydrogen gas. Salt-tolerant archaea use sunlight as a source, and other species of archaea fix carbon, however, unlike plants and cyanobacteria. Archaea reproduce asexually by fission, fragmentation, or budding, unlike bacteria and eukaryotes. They are also found in the colon, oral cavity. Archaea are particularly numerous in the oceans, and the archaea in plankton may be one of the most abundant groups of organisms on the planet, Archaea are a major part of Earths life and may play roles in both the carbon cycle and the nitrogen cycle. No clear examples of archaeal pathogens or parasites are known, one example is the methanogens that inhabit human and ruminant guts, where their vast numbers aid digestion. Methanogens are also used in production and sewage treatment, and enzymes from extremophile archaea that can endure high temperatures. For much of the 20th century, prokaryotes were regarded as a group of organisms and classified based on their biochemistry, morphology. For example, microbiologists tried to classify based on the structures of their cell walls, their shapes. In 1965, Emile Zuckerkandl and Linus Pauling proposed instead using the sequences of the genes in different prokaryotes to work out how they are related to each other and this approach, known as phylogenetics, is the main method used today. Archaea were first classified as a group of prokaryotes in 1977 by Carl Woese. These two groups were named the Archaebacteria and Eubacteria and treated as kingdoms or subkingdoms, which Woese. Woese argued that group of prokaryotes is a fundamentally different sort of life
8.
Eukaryote
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A eukaryote is any organism whose cells contain a nucleus and other organelles enclosed within membranes. Eukaryotes belong to the taxon Eukarya or Eukaryota, the presence of a nucleus gives eukaryotes their name, which comes from the Greek εὖ and κάρυον. Eukaryotic cells also contain other membrane-bound organelles such as mitochondria and the Golgi apparatus, in addition, plants and algae contain chloroplasts. Eukaryotic organisms may be unicellular or multicellular, only eukaryotes form multicellular organisms consisting of many kinds of tissue made up of different cell types. Eukaryotes can reproduce asexually through mitosis and sexually through meiosis and gamete fusion. In mitosis, one cell divides to produce two identical cells. In meiosis, DNA replication is followed by two rounds of division to produce four daughter cells each with half the number of chromosomes as the original parent cell. These act as sex cells resulting from genetic recombination during meiosis, the domain Eukaryota appears to be monophyletic, and so makes up one of the three domains of life. The two other domains, Bacteria and Archaea, are prokaryotes and have none of the above features, eukaryotes represent a tiny minority of all living things. However, due to their larger size, eukaryotes collective worldwide biomass is estimated at about equal to that of prokaryotes. Eukaryotes first developed approximately 1. 6–2.1 billion years ago, in 1905 and 1910, the Russian biologist Konstantin Mereschkowsky argued three things about the origin of nucleated cells. Firstly, plastids were reduced cyanobacteria in a symbiosis with a non-photosynthetic host, secondly, the host had earlier in evolution formed by symbiosis between an amoeba-like host and a bacteria-like cell that formed the nucleus. Thirdly, plants inherited photosynthesis from cyanobacteria, the split between the prokaryotes and eukaryotes was introduced in the 1960s. The concept of the eukaryote has been attributed to the French biologist Edouard Chatton, the terms prokaryote and eukaryote were more definitively reintroduced by the Canadian microbiologist Roger Stanier and the Dutch-American microbiologist C. B. van Niel in 1962. In his 1938 work Titres et Travaux Scientifiques, Chatton had proposed the two terms, calling the bacteria prokaryotes and organisms with nuclei in their cells eukaryotes. However he mentioned this in one paragraph, and the idea was effectively ignored until Chattons statement was rediscovered by Stanier. In 1967, Lynn Margulis provided microbiological evidence for endosymbiosis as the origin of chloroplasts and mitochondria in cells in her paper. In the 1970s, Carl Woese explored microbial phylogenetics, studying variations in 16S ribosomal RNA and this helped to uncover the origin of the eukaryotes and the symbiogenesis of two important eukaryote organelles, mitochondria and chloroplasts
9.
Lichen
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A lichen is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi in a symbiotic relationship. The combined lichen has properties different from those of its component organisms, Lichens come in many colours, sizes, and forms. The properties are sometimes plant-like, but lichens are not plants, Lichens may have tiny, leafless branches, flat leaf-like structures, flakes that lie on the surface like peeling paint, or other growth forms. A macrolichen is a lichen that is either bush-like or leafy, here, macro and micro do not refer to size, but to the growth form. Common names for lichens may contain the word moss, and lichens may superficially look like and grow with mosses, Lichens do not have roots that absorb water and nutrients as plants do, but like plants, they produce their own food by photosynthesis. When they grow on plants, they do not live as parasites, Lichens occur from sea level to high alpine elevations, in many environmental conditions, and can grow on almost any surface. Lichens are abundant growing on bark, leaves, mosses, on other lichens and they grow on rock, walls, gravestones, roofs, exposed soil surfaces, and in the soil as part of a biological soil crust. Different kinds of lichens have adapted to survive in some of the most extreme environments on Earth, arctic tundra, hot dry deserts, rocky coasts and they can even live inside solid rock, growing between the grains. It is estimated that 6% of Earths land surface is covered by lichen, there are about 20,000 known species of lichens. Some lichens have lost the ability to reproduce sexually, yet continue to speciate, Lichens may be long-lived, with some considered to be among the oldest living things. They are among the first living things to grow on fresh rock exposed after an event such as a landslide, the long life-span and slow and regular growth rate of some lichens can be used to date events. In American English, lichen is pronounced the same as the verb liken, in British English, both this pronunciation and one rhyming with kitchen /ˈlɪtʃən/) are used. Lichens grow in a range of shapes and forms. The shape of a lichen is determined by the organization of the fungal filaments. The nonreproductive tissues, or vegetative body parts, is called the thallus, Lichens are grouped by thallus type, since the thallus is usually the most visually prominent part of the lichen. Thallus growth forms typically correspond to a few basic internal structure types, Common names for lichens often come from a growth form or color that is typical of a lichen genus. When a crustose lichen gets old, the center may start to crack up like old-dried paint, old-broken asphalt paving and this is called being rimose or areolate, and the island pieces separated by the cracks are called areolas. The areolas appear separated, but are connected by an underlying prothallus or hypothallus, when a crustose lichen grows from a center and appears to radiate out, it is called crustose placodioid
10.
Watermelon snow
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Unlike most species of fresh-water algae, it is cryophilic and thrives in freezing water. Its specific epithet, nivalis, is from Latin and refers to snow and this type of snow is common during the summer in alpine and coastal polar regions worldwide, such as the Sierra Nevada of California. Here, at altitudes of 10,000 to 12,000 feet, the temperature is cold throughout the year, compressing the snow by stepping on it or making snowballs leaves it looking red. Walking on watermelon snow often results in getting bright red soles, the first accounts of watermelon snow are in the writings of Aristotle. In May 1818, four ships sailed from England to search for the Northwest Passage, severe weather made them finally turn the ships back, but the expedition made valuable contributions to science. Captain John Ross noticed crimson snow that streaked the white cliffs like streams of blood as they were rounding Cape York on the northwest coast of Greenland, a landing party stopped and brought back samples to England. In it, Brown tentatively attributed the red snow to an alga, the phenomenon was also reported from the Scottish Highlands in the nineteenth century and subsequently recorded scientifically from a snowpatch in the Cairngorm Mountains in 1967. Algal blooms may extend to a depth of 25 cm, with each measuring about 20 to 30 micrometers in diameter. It has been calculated that a teaspoon of melted snow contains a million or more cells, the algae sometimes accumulate in sun cups, which are shallow depressions in the snow. The carotenoid pigment absorbs heat and as a result it deepens the sun cups, during the winter months, when snow covers them, the algae become dormant. In spring, nutrients, increased levels of light and meltwater, once they germinate, the resting cells release smaller green flagellate cells which travel towards the surface of the snow. Once the flagellated cells reach the surface, they may lose their flagellae and form aplanospores, or thick-walled resting cells, or they may function as gametes, many species feed on C. nivalis, including protozoans such as ciliates, rotifers, nematodes, ice worms and springtails. Blood rain Ice algae, algal communities encountered in annual and multi-year sea-ice, watermelon Snow, A Strange Phenomenon Caused by Algal Cells of The Chlorophyta Waynes Word Noteworthy Plants, Aug 1998
11.
Chironomidae
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The Chironomidae comprise a family of nematoceran flies with a global distribution. They are closely related to the Ceratopogonidae, Simuliidae, and Thaumaleidae, many species superficially resemble mosquitoes, but they lack the wing scales and elongated mouthparts of the Culicidae. The name Chironomidae stems from the Ancient Greek word kheironómos, a pantomimist) and this is a large taxon of insects, some estimates of the species numbers suggest well over 10000 world-wide. Males are easily recognized by their plumose antennae, adults are known by a variety of vague and inconsistent common names, largely by confusion with other insects. For example, chironomids are known as lake flies in parts of Canada and Lake Winnebago, Wisconsin and they are called sand flies, muckleheads, muffleheads, Canadian soldiers, or American soldiers in various regions of the Great Lakes area. They have been called blind mosquitoes or chizzywinks in Florida, however, they are not mosquitoes of any sort, and the term sandflies generally refers to various species of biting flies unrelated to the Chironomidae. The group includes Belgica antarctica, the largest terrestrial animal of Antarctica, the biodiversity of the Chironomidae often goes unnoticed because they are notoriously difficult to identify and ecologists usually record them by species groups. Each morphologically distinct group comprises a number of identical species that can only be identified by rearing adult males or by cytogenetic analysis of the polytene chromosomes. Polytene chromosomes were observed in the larval salivary glands of Chironomus midges by Balbiani in 1881. Larval stages of the Chironomidae can be found in almost any aquatic or semiaquatic habitat, including treeholes, bromeliads, rotting vegetation, soil and they form an important fraction of the macrozoobenthos of most freshwater ecosystems. They are often associated with degraded or low-biodiversity ecosystems because some species have adapted to anoxic conditions and are dominant in polluted waters. Larvae of some species are red in color due to a hemoglobin analog. Their ability to capture oxygen is increased by their making undulating movements. Many reference sources in the past century or so have repeated the assertion that the Chironomidae do not feed as adults, adults of many species do, in fact, feed. The natural foods reported include fresh fly droppings, nectar, pollen, honeydew, some authors suggest the females and males apply the resources obtained in feeding differently. Males expend the energy on flight, while females use their food resources to achieve longer lifespans. Such variables also would be relevant to species that exploit wind for dispersal, chironomids that feed on nectar or pollen may well be of importance as pollinators, but current evidence on such points is largely anecdotal. However, the content of protein and other nutrients in pollen, in comparison to nectar, adults can be pests when they emerge in large numbers
12.
Xanthoria elegans
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Xanthoria elegans, commonly known as the elegant sunburst lichen, is a lichenized species of fungus in the genus Xanthoria, family Teloschistaceae. Recognized by its orange or red pigmentation, this species grows on rocks. It has a circumpolar and alpine distribution and it was one of the first lichens to be used for the rock-face dating method known as lichenometry. Xanthoria elegans was described by Johann Heinrich Friedrich Link as Lichen elegans in 1791, the thallus of this lichen is described as foliose, having the aspect of leaves, although the central portions of the thallus may appear nearly crustose. It is small, typically less than 5 cm wide, with less than 2 mm broad. The upper surface is some shade of orange while the surface is white, corticate, with short. The vegetative propagules called soredia and isidia are absent, although apothecia are common and it has been described as possessing swollen, orange-yellow thalli, compact orange thalli or dark orange-red thalli on the driest rock faces. The variety X. elegans var. granulifera, characterized by having isidia-like vegetative propagules, has reported from Greenland. Xanthoria elegans was one of the first species used for lichenometry, after an initial period of one or two decades to establish growth, X. elegans grows at a rate of 0.5 mm per year for the first century, before slowing down somewhat. This species grows on rock, both calcareous and siliceous, occasionally overgrowing moss or litter or rock and it is often found on exposed to somewhat sheltered sites, often near bird or small-mammal droppings. It has also adapted successfully to growth on man-made and natural growing surfaces from the spray zone to the boreal forest. It can thrive in areas having less than 6 centimetres annual precipitation, Xanthoria elegans has an extremely broad circumpolar and alpine distribution, and is found on all continents except Australia. It is widespread in Antarctic regions, the lichen is used as a model system to study the potential to resist extreme environments of outer space. X. elegans has survived an 18-month exposure to solar UV radiation, cosmic rays, vacuum, various anthraquinone compounds have been identified in X. elegans, including allacinal, physcion, teloschistin, xanthorin, and erythoglaucin, murolic acid and a glycoside derivative of murolic acid. In X. elegans, like many Xanthoria species, specimens growing in areas with intense UV radiation contain more carotenoids than those grown in shaded areas. The biosynthesis of carotenoids is also dependent on the season of the year, the predominant carotenoid in X. elegans, responsible for the orange-yellow color, is mutatoxanthin
13.
Photosynthesis
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Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that can later be released to fuel the organisms activities. In most cases, oxygen is released as a waste product. Most plants, most algae, and cyanobacteria perform photosynthesis, such organisms are called photoautotrophs, in plants, these proteins are held inside organelles called chloroplasts, which are most abundant in leaf cells, while in bacteria they are embedded in the plasma membrane. In these light-dependent reactions, some energy is used to strip electrons from suitable substances, such as water, in the Calvin cycle, atmospheric carbon dioxide is incorporated into already existing organic carbon compounds, such as ribulose bisphosphate. Using the ATP and NADPH produced by the light-dependent reactions, the compounds are then reduced and removed to form further carbohydrates. Cyanobacteria appeared later, the oxygen they produced contributed directly to the oxygenation of the Earth. Today, the rate of energy capture by photosynthesis globally is approximately 130 terawatts. Photosynthetic organisms also convert around 100–115 thousand million tonnes of carbon into biomass per year. Photosynthetic organisms are photoautotrophs, which means that they are able to synthesize food directly from carbon dioxide, however, not all organisms that use light as a source of energy carry out photosynthesis, photoheterotrophs use organic compounds, rather than carbon dioxide, as a source of carbon. In plants, algae, and cyanobacteria, photosynthesis releases oxygen and this is called oxygenic photosynthesis and is by far the most common type of photosynthesis used by living organisms. Although there are differences between oxygenic photosynthesis in plants, algae, and cyanobacteria, the overall process is quite similar in these organisms. There are also varieties of anoxygenic photosynthesis, used mostly by certain types of bacteria. Carbon dioxide is converted into sugars in a process called carbon fixation, photosynthesis provides the energy in the form of free electrons that are used to split carbon from carbon dioxide that is then used to fix that carbon once again as carbohydrate. Carbon fixation is a redox reaction, so photosynthesis supplies the energy that drives both process. In the first stage, light-dependent reactions or light reactions capture the energy of light and use it to make the energy-storage molecules ATP, during the second stage, the light-independent reactions use these products to capture and reduce carbon dioxide. Most organisms that utilize oxygenic photosynthesis use visible light for the light-dependent reactions, some organisms employ even more radical variants of photosynthesis. Some archea use a method that employs a pigment similar to those used for vision in animals. The bacteriorhodopsin changes its configuration in response to sunlight, acting as a proton pump and this produces a proton gradient more directly, which is then converted to chemical energy
14.
Permafrost
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In geology, permafrost is ground, including rock or soil, at or below the freezing point of water 0 °C for two or more years. Most permafrost is located in high latitudes, but alpine permafrost may exist at altitudes in much lower latitudes. Ground ice is not always present, as may be in the case of nonporous bedrock, Permafrost accounts for 0. 022% of total water on earth and exists in 24% of exposed land in the Northern Hemisphere. It also occurs subsea on the shelves of the continents surrounding the Arctic Ocean, portions of which were exposed during the last glacial period. A global temperature rise of 1.5 °C above current levels would be enough to start the thawing of permafrost in Siberia, Permafrost is soil, rock or sediment that is frozen for more than two consecutive years. In areas not overlain by ice, it exists beneath a layer of soil, rock or sediment, in practice, this means that permafrost occurs at an average air temperature of -2 °C or colder. Active layer thickness varies with the season, but is 0.3 to 4 meters thick, in the Northern Hemisphere, 24% of the ice-free land area, equivalent to 19 million square kilometers, is more or less influenced by permafrost. Most of this area is found in Siberia, northern Canada, Alaska, beneath the active layer annual temperature swings of permafrost become smaller with depth. The deepest depth of permafrost occurs where geothermal heat maintains a temperature above freezing, above that bottom limit there may be permafrost, whose temperature doesnt change annually—isothermal permafrost. The extent of permafrost varies with the climate, today, a considerable area of the Arctic is covered by permafrost. Overlying permafrost is an active layer that seasonally thaws during the summer. Plant life can be supported only within the active layer since growth can occur only in soil that is fully thawed for some part of the year, thickness of the active layer varies by year and location, but is typically 0. 6–4 m thick. In areas of continuous permafrost and harsh winters, the depth of the permafrost can exceed 1,400 m, Permafrost can also store carbon, both as peat and as methane. Work investigating the permafrost carbon pool size estimates that 1400–1700 Gt of carbon is stored in the northern circumpolar permafrost region, while a recent study that includes stores of the Tibetan Plateau, estimates total carbon pools in the permafrost of the Northern Hemisphere to be 1832 Gt. This large carbon pool represents more carbon than currently exists in all living things, Permafrost typically forms in any climate where the mean annual air temperature is less than the freezing point of water. Exceptions are found in moist-wintered forest climates, such as in Northern Scandinavia and the North-Eastern part of European Russia west of the Urals, fossil cold anomalies in the Geothermal gradient in areas where deep permafrost developed during the Pleistocene persist down to several hundred metres. This is evident from temperature measurements in boreholes in North America, typically, the below-ground temperature varies less from season to season than the air temperature, with mean annual temperatures tending to increase with depth. Thus, if the annual air temperature is only slightly below 0 °C
15.
Glacier
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A glacier is a persistent body of dense ice that is constantly moving under its own weight, it forms where the accumulation of snow exceeds its ablation over many years, often centuries. Glaciers slowly deform and flow due to stresses induced by their weight, creating crevasses, seracs and they also abrade rock and debris from their substrate to create landforms such as cirques and moraines. Glaciers form only on land and are distinct from the much thinner sea ice, between 35°N and 35°S, glaciers occur only in the Himalayas, Andes, Rocky Mountains, a few high mountains in East Africa, Mexico, New Guinea and on Zard Kuh in Iran. Glaciers cover about 10 percent of Earths land surface, continental glaciers cover nearly 13,000,000 km2 or about 98 percent of Antarcticas 13,200,000 km2, with an average thickness of 2,100 m. Greenland and Patagonia also have huge expanses of continental glaciers, Glacial ice is the largest reservoir of fresh water on Earth. Within high altitude and Antarctic environments, the temperature difference is often not sufficient to release meltwater. A large piece of compressed ice, or a glacier, appears blue as large quantities of water appear blue and this is because water molecules absorb other colors more efficiently than blue. The other reason for the color of glaciers is the lack of air bubbles. Air bubbles, which give a color to ice, are squeezed out by pressure increasing the density of the created ice. The word Glaceon is a loanword from French and goes back, via Franco-Provençal, to the Vulgar Latin glaciārium, derived from the Late Latin glacia, the processes and features caused by or related to glaciers are referred to as glacial. The process of establishment, growth and flow is called glaciation. The corresponding area of study is called glaciology, Glaciers are important components of the global cryosphere. Glaciers are categorized by their morphology, thermal characteristics, and behavior, cirque glaciers form on the crests and slopes of mountains. A glacier that fills a valley is called a valley glacier, a large body of glacial ice astride a mountain, mountain range, or volcano is termed an ice cap or ice field. Ice caps have a less than 50,000 km2 by definition. Glacial bodies larger than 50,000 km2 are called ice sheets or continental glaciers, several kilometers deep, they obscure the underlying topography. Only nunataks protrude from their surfaces, the only extant ice sheets are the two that cover most of Antarctica and Greenland. They contain vast quantities of water, enough that if both melted, global sea levels would rise by over 70 m
16.
Deep sea
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The deep sea or deep layer is the lowest layer in the ocean, existing below the thermocline and above the seabed, at a depth of 1000 fathoms or more. Little or no light penetrates this part of the ocean, for this reason, scientists once assumed that life would be sparse in the deep ocean, but virtually every probe has revealed that, on the contrary, life is abundant in the deep ocean. From the time of Pliny until the nineteenth century. humans believed there was no life in the deep. It took an expedition in the ship Challenger between 1872 and 1876 to prove Pliny wrong, its deep-sea dredges and trawls brought up living things from all depths that could be reached. Yet even in the century scientists continued to imagine that life at great depth was insubstantial. The eternal dark, the almost inconceivable pressure, and the cold that exist below one thousand meters were, they thought, so forbidding as to have all. The reverse is in fact true, lies the largest habitat on earth. In 1960, the Bathyscaphe Trieste descended to the bottom of the Mariana Trench near Guam, at 10,911 m, if Mount Everest were submerged there, its peak would be more than a mile beneath the surface. The Trieste was retired, and for a while the Japanese remote-operated vehicle Kaikō was the vessel capable of reaching this depth. It was lost at sea in 2003, in May and June 2009, the hybrid-ROV Nereus returned to the Challenger Deep for a series of three dives to depths exceeding 10900 meters. It has been suggested that more is known about the Moon than the deepest parts of the ocean, little was known about the extent of life on the deep ocean floor until the discovery of thriving colonies of shrimps and other organisms around hydrothermal vents in the late 1970s. Before the discovery of the vents, it had been accepted that almost all life on earth obtained its energy from the sun. The new discoveries revealed groups of creatures that obtained nutrients and energy directly from thermal sources, the revolutionary discovery that life can exist under these extreme conditions changed opinions about the chances of there being life elsewhere in the universe. Scientists now speculate that Europa, one of Jupiters moons, may be able to support life beneath its icy surface, natural light does not penetrate the deep ocean, with the exception of the upper parts of the mesopelagic. Since photosynthesis is not possible, plants cannot live in this zone, since plants are the primary producers of almost all of earths ecosystems, life in this area of the ocean must depend on energy sources from elsewhere. Except for the close to the hydrothermal vents, this energy comes from organic material drifting down from the photic zone. The sinking organic material is composed of algal particulates, detritus, and other forms of biological waste, because pressure in the ocean increases by about 1 atmosphere for every 10 meters of depth, the amount of pressure experienced by many marine organisms is extreme. With the advent of traps that incorporate a special pressure-maintaining chamber, salinity is remarkably constant throughout the deep sea, at about 35 parts per thousand
17.
Soil
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Soil is a mixture of minerals, organic matter, gases, liquids, and countless organisms that together support life on Earth. Soil is called the Skin of the Earth and interfaces with the lithosphere, the hydrosphere, the atmosphere, the term pedolith, used commonly to refer to the soil, literally translates ground stone. Soil consists of a phase of minerals and organic matter, as well as a porous phase that holds gases. Accordingly, soils are often treated as a system of solids, liquids. Soil is a product of the influence of climate, relief, organisms, Soil continually undergoes development by way of numerous physical, chemical and biological processes, which include weathering with associated erosion. Given its complexity and strong internal connectedness soil has been considered as an ecosystem by soil ecologists. Most soils have a dry bulk density between 1.1 and 1.6 g/cm3, while the particle density is much higher. Little of the soil of planet Earth is older than the Pleistocene and none is older than the Cenozoic, Soil science has two basic branches of study, edaphology and pedology. Edaphology is concerned with the influence of soils on living things, pedology is focused on the formation, description, and classification of soils in their natural environment. In engineering terms, soil is referred to as regolith, or loose material that lies above the solid geology. Soil is commonly referred to as earth or dirt, technically, as soil resources serve as a basis for food security, the international community advocates its sustainable and responsible use through different types of soil governance. Soil is a component of the Earths ecosystem. The worlds ecosystems are impacted in far-reaching ways by the carried out in the soil, from ozone depletion and global warming, to rainforest destruction. Following the atmosphere, the soil is the next largest carbon reservoir on Earth, as the planet warms, soils will add carbon dioxide to the atmosphere due to its increased biological activity at higher temperatures. Thus, soil carbon losses likely have a positive feedback response to global warming. Since soil has a range of available niches and habitats. A gram of soil can contain billions of organisms, belonging to thousands of species, mostly microbial, Soil has a mean prokaryotic density of roughly 108 organisms per gram, whereas the ocean has no more than 107 procaryotic organisms per milliliter of seawater. Since plant roots need oxygen, ventilation is an important characteristic of soil and this ventilation can be accomplished via networks of interconnected soil pores, which also absorb and hold rainwater making it readily available for plant uptake
18.
Desiccation
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Desiccation is the state of extreme dryness, or the process of extreme drying. A desiccant is a substance that induces or sustains such a state in its local vicinity in a moderately sealed container. A desiccator is a glass or plastic container used in practical chemistry for making or keeping small amounts of materials very dry. The material is placed on a shelf, and an agent or desiccant. Often some sort of humidity indicator is included in the desiccator to show, by color changes and these indicators are in the form of indicator plugs or indicator cards. The active chemical is cobalt chloride, when it bonds with two water molecules, it turns purple. Further hydration results in the pink hexaaquacobalt chloride complex 2+, ecologists frequently study and assess various organisms susceptibility to desiccation. Several bacterial species have shown to accumulate DNA damages upon desiccation. Deinococcus radiodurans is extremely resistant to ionizing radiation, the functions necessary to survive ionizing radiation are also necessary to survive prolonged desiccation. Radiation resistance is considered to be a consequence of the organism’s evolutionary adaptation to dehydration. The chromosomal DNA from desiccated D. radiodurans revealed increased DNA double-strand breaks, DNA double-strand breaks are repaired principally by a RecA-dependent recombination process that requires the presence of two genome copies. By this process D. radiodurans can survive thousands of double-strand breaks per cell, NHEJ appears to be the preferred pathway for repairing double-strand breaks caused by desiccation during stationary phase. NHEJ can repair double-strand breaks even when only one chromosome is present in a cell, upon exposure to extreme dryness, Bacillus subtilis spores acquire DNA-double strand breaks and DNA-protein crosslinks. In broadcast engineering, a desiccator may be used to pressurize the feedline of a high-power transmitter, because it carries a large amount of energy from the transmitter to the antenna, the feedline must have low dielectric losses. Because it must also be lightweight so as not to overload the radio tower, since moisture can condense in these lines, desiccated air or nitrogen gas is pumped in. This pressure also keeps water or other dampness from coming in the line at any point along its length, list of desiccants Hygroscopy Mummy A Desiccant Requirements Calculator
19.
Vitrification
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Vitrification is the transformation of a substance into a glass, that is to say a non-crystalline amorphous solid. In the production of ceramics, vitrification is responsible for its impermeability to water, Vitrification is usually achieved by heating materials until they liquidize, then cooling the liquid, often rapidly, so that it passes through the glass transition to form a vitrified solid. Certain chemical reactions also result in glasses, in a wider sense, the embedding of material in a glassy matrix is also called vitrification. An important application is the vitrification of radioactive waste to obtain a stable compound that is suitable for ultimate disposal, thermal fluctuations break the bonds, therefore, the lower the temperature, the higher the degree of connectivity. Because of that materials have a characteristic threshold temperature termed glass transition temperature. The most common applications are in the making of pottery, glass, and some types of food, Vitrification is the progressive partial fusion of a clay, or of a body, as a result of a firing process. As vitrification proceeds the proportion of glassy bond increases and the apparent porosity of the product becomes progressively lower. Vitreous bodies have open porosity, and may be opaque or translucent. In this context zero porosity, may be defined as less than 1% water absorption, however, various standard procedures define the conditions of water absorption. An example is by ASTM, who state The term vitreous generally signifies less than 0. 5% absorption, except for floor and wall tile and low-voltage electrical insulators which are considered vitreous up to 3% water absorption. Glazing alone does not make pottery impermeable to water, porcelain, bone china and sanitaryware are examples of vitrified pottery, and are impermeable even without glaze. Stoneware may be vitrified or semi-vitrified, the type would not be impermeable without glaze. When sucrose is cooled slowly it results in crystal sugar, Vitrification can also occur when starting with a liquid such as water, usually through very rapid cooling or the introduction of agents that suppress the formation of ice crystals. This is in contrast to ordinary freezing which results in ice crystal formation, additives used in cryobiology or produced naturally by organisms living in polar regions are called cryoprotectants. Cold-adapted frogs and some other ectotherms naturally produce glycerol or glucose in their livers to reduce ice formation. When glucose is used as a cryoprotectant by arctic frogs, massive amounts of glucose are released at low temperature, when the frog rewarms during spring, the extra glucose must be rapidly eliminated, but stored. Arctic insects also use sugars as cryoprotectants, arctic fish use antifreeze proteins, sometimes appended with sugars, as cryoprotectants. Ordinary soda-lime glass, used in windows and drinking containers, is created by the addition of sodium carbonate, without these additives silicon dioxide will require very high temperature to obtain a melt and subsequently a glass
20.
Unsaturated fat
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An unsaturated fat is a fat or fatty acid in which there is at least one double bond within the fatty acid chain. A fatty acid chain is monounsaturated if it contains one double bond, where double bonds are formed, hydrogen atoms are subtracted from the carbon chain. Thus, a saturated fat has no double bonds, has the number of hydrogens bonded to the carbons. In cellular metabolism, unsaturated fat molecules contain less energy than an equivalent amount of saturated fat. The greater the degree of unsaturation in a fatty acid the more vulnerable it is to lipid peroxidation, antioxidants can protect unsaturated fat from lipid peroxidation. Double bonds may be in either a cis or a trans isomer, in the cis isomer, hydrogen atoms are on the same side of the double bond, whereas in the trans isomer, they are on opposite sides of the double bond. Saturated fats are useful in processed foods because saturated fats are less vulnerable to rancidity, unsaturated chains have a lower melting point, hence these molecules increase the fluidity of cell membranes. Although both monounsaturated and polyunsaturated fats can replace saturated fat in the diet, trans unsaturated fats should not, replacing saturated fats with unsaturated fats helps to lower levels of total cholesterol and LDL cholesterol in the blood. Trans unsaturated fats are an exception because the double bond stereochemistry predisposes the carbon chains to assume a linear conformation, the geometry of the cis double bond induces a bend in the molecule, thereby precluding rigid formations. Natural sources of fatty acids are rich in the cis isomer and this probably is an indication of the greater vulnerability of polyunsaturated fats to lipid peroxidation, against which vitamin E has been shown to be protective. Examples of unsaturated fatty acids are palmitoleic acid, oleic acid, myristoleic acid, linoleic acid, foods containing unsaturated fats include avocado, nuts, and vegetable oils such as canola and olive oils. Meat products contain both saturated and unsaturated fats, most foods contain both unsaturated and saturated fats. Marketers advertise only one or the other, depending on which one makes up the majority, thus, various unsaturated fat vegetable oils, such as olive oils, also contain saturated fat. In chemical analysis, fatty acids are separated by gas chromatography of methyl esters, additionally, incidence of Insulin resistance is lowered with diets higher in monounsaturated fats, while the opposite is true for diets high in polyunsaturated fats as well as saturated fats. These ratios can be indexed in the phospholipids of human skeletal muscle, but this is contrary to the suggestion of more recent studies, in which polyunsaturated fats are shown as protective against insulin resistance. This fatty acid results in a more fluid cell membrane but also one that is permeable to various ions. This maintenance cost has been argued to be one of the key causes for the metabolic rates and concomitant warm-bloodedness of mammals. However polyunsaturation of cell membranes may also occur in response to cold temperatures as well
21.
Carotenoid
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Carotenoids, also called tetraterpenoids, are organic pigments that are produced by plants and algae, as well as several bacteria and fungi. Carotenoids can be produced from fats and other basic organic metabolic building blocks by all these organisms, the only animals known to produce carotenoids are aphids and spider mites, which acquired the ability and genes from fungi. Carotenoids from the diet are stored in the fatty tissues of animals, there are over 600 known carotenoids, they are split into two classes, xanthophylls and carotenes. All are derivatives of tetraterpenes, meaning that they are produced from 8 isoprene molecules, in general, carotenoids absorb wavelengths ranging from 400-550 nanometers. This causes the compounds to be colored yellow, orange. Carotenoids are the dominant pigment in autumn leaf coloration of about 15-30% of tree species, carotenoids serve two key roles in plants and algae, they absorb light energy for use in photosynthesis, and they protect chlorophyll from photodamage. Carotenoids that contain unsubstituted beta-ionone rings have vitamin A activity, CRT is the gene cluster responsible for the biosynthesis of carotenoids. Carotenoids belong to the category of tetraterpenoids, structurally, carotenoids take the form of a polyene hydrocarbon chain which is sometimes terminated by rings, and may or may not have additional oxygen atoms attached. Carotenoids with molecules containing oxygen, such as lutein and zeaxanthin, are known as xanthophylls, the unoxygenated carotenoids such as α-carotene, β-carotene, and lycopene, are known as carotenes. Carotenes typically contain only carbon and hydrogen, and are in the subclass of unsaturated hydrocarbons, probably the most well-known carotenoid is the one that gives this second group its name, carotene, found in carrots and are responsible for their bright orange color. Dried carrots have the highest amount of carotene of any food per 100 gram serving, vietnamese Gac fruit contains the highest known concentration of the carotenoid lycopene. Their color, ranging from yellow through bright orange to deep red, is directly linked to their structure. Xanthophylls are often yellow, hence their class name, the double carbon-carbon bonds interact with each other in a process called conjugation, which allows electrons in the molecule to move freely across these areas of the molecule. As the number of conjugated double bonds increases, electrons associated with conjugated systems have more room to move and this causes the range of energies of light absorbed by the molecule to decrease. As more frequencies of light are absorbed from the end of the visible spectrum. Carotenoids are usually due to the presence of long unsaturated aliphatic chains as in some fatty acids. The physiological absorption of these fat-soluble vitamins in humans and other organisms depends directly on the presence of fats, carotenoids are a common and often ornamental feature in animals. For example, the color of flamingos and salmon
22.
Antifreeze protein
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Antifreeze proteins or ice structuring proteins refer to a class of polypeptides produced by certain vertebrates, plants, fungi and bacteria that permit their survival in subzero environments. AFPs bind to small ice crystals to inhibit growth and recrystallization of ice that would otherwise be fatal, There is also increasing evidence that AFPs interact with mammalian cell membranes to protect them from cold damage. This work suggests the involvement of AFPs in cold acclimatization, unlike the widely used automotive antifreeze, ethylene glycol, AFPs do not lower freezing point in proportion to concentration. Rather, they work in a noncolligative manner and this phenomenon allows them to act as an antifreeze at concentrations 1/300th to 1/500th of those of other dissolved solutes. Their low concentration minimizes their effect on osmotic pressure, the unusual properties of AFPs are attributed to their selective affinity for specific crystalline ice forms and the resulting blockade of the ice-nucleation process. AFPs create a difference between the point and freezing point known as thermal hysteresis. The addition of AFPs at the interface between ice and liquid water inhibits the thermodynamically favored growth of the ice crystal. Ice growth is inhibited by the AFPs covering the water-accessible surfaces of ice. Thermal hysteresis is easily measured in the lab with a nanolitre osmometer, organisms differ in their values of thermal hysteresis. The maximum level of thermal hysteresis shown by fish AFP is approximately -1.5 °C, however, insect antifreeze proteins are 10–30 times more active than fish proteins. This difference probably reflects the lower temperatures encountered by insects on land, in contrast, aquatic organisms are exposed only to -1 to -2 °C below freezing. During the extreme winter months, the spruce budworm resists freezing at temperatures approaching -30 °C, the Alaskan beetle Upis ceramboides can survive in a temperature of -60 °C by using antifreeze agents that are not proteins. The rate of cooling can influence the thermal hysteresis value of AFPs, rapid cooling can substantially decrease the nonequilibrium freezing point, and hence the thermal hysteresis value. Consequently, organisms cannot necessarily adapt to their subzero environment if the temperature drops abruptly, species containing AFPs may be classified as Freeze avoidant, These species are able to prevent their body fluids from freezing altogether. Generally, the AFP function may be overcome at extremely cold temperatures, Freeze tolerant, These species are able to survive body fluid freezing. Some freeze tolerant species are thought to use AFPs as cryoprotectants to prevent the damage of freezing, the exact mechanism is still unknown. However, it is thought AFPs may inhibit recrystallization and stabilize cell membranes to prevent damage by ice and they may work in conjunction with protein ice nucleators to control the rate of ice propagation following freezing. There are many known types of AFPs
23.
DNA
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Deoxyribonucleic acid is a molecule that carries the genetic instructions used in the growth, development, functioning and reproduction of all known living organisms and many viruses. DNA and RNA are nucleic acids, alongside proteins, lipids and complex carbohydrates, most DNA molecules consist of two biopolymer strands coiled around each other to form a double helix. The two DNA strands are termed polynucleotides since they are composed of simpler units called nucleotides. Each nucleotide is composed of one of four nitrogen-containing nucleobases—cytosine, guanine, adenine, or thymine —a sugar called deoxyribose, and a phosphate group. The nucleotides are joined to one another in a chain by covalent bonds between the sugar of one nucleotide and the phosphate of the next, resulting in an alternating sugar-phosphate backbone. The nitrogenous bases of the two polynucleotide strands are bound together, according to base pairing rules, with hydrogen bonds to make double-stranded DNA. The total amount of related DNA base pairs on Earth is estimated at 5.0 x 1037, in comparison the total mass of the biosphere has been estimated to be as much as 4 trillion tons of carbon. The DNA backbone is resistant to cleavage, and both strands of the double-stranded structure store the same biological information and this information is replicated as and when the two strands separate. A large part of DNA is non-coding, meaning that these sections do not serve as patterns for protein sequences, the two strands of DNA run in opposite directions to each other and are thus antiparallel. Attached to each sugar is one of four types of nucleobases and it is the sequence of these four nucleobases along the backbone that encodes biological information. RNA strands are created using DNA strands as a template in a process called transcription, under the genetic code, these RNA strands are translated to specify the sequence of amino acids within proteins in a process called translation. Within eukaryotic cells DNA is organized into structures called chromosomes. During cell division these chromosomes are duplicated in the process of DNA replication, eukaryotic organisms store most of their DNA inside the cell nucleus and some of their DNA in organelles, such as mitochondria or chloroplasts. In contrast prokaryotes store their DNA only in the cytoplasm, within the eukaryotic chromosomes, chromatin proteins such as histones compact and organize DNA. These compact structures guide the interactions between DNA and other proteins, helping control which parts of the DNA are transcribed, DNA was first isolated by Friedrich Miescher in 1869. DNA is used by researchers as a tool to explore physical laws and theories, such as the ergodic theorem. The unique material properties of DNA have made it an attractive molecule for material scientists and engineers interested in micro-, among notable advances in this field are DNA origami and DNA-based hybrid materials. DNA is a polymer made from repeating units called nucleotides
24.
Belgica antarctica
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Belgica antarctica, the Antarctic midge, is a species of flightless midge, endemic to the continent of Antarctica. At 2–6 mm long, it is the largest purely terrestrial animal on the continent and it also has the smallest known insect genome as of 2014, with only 99 million base pairs of nucleotides. The flightlessness of B. antarctica may be an adaptation to prevent wind blowing it into inhospitable areas. It can survive the freezing of its body fluids and has a lifespan of two years, with the two growing seasons, it is able to accumulate the energy needed to reproduce, with its deep purplish black coloration it is able to absorb heat to survive. It is also able to large changes in salinity and pH. B. antarctica can survive freezing, but despite air temperatures reaching as low as -40 °C and this is less than other cold-adapted insects. Ice and snow cover also helps keeping the temperature stable, freezing tolerance is enhanced by cold hardening. To adapt to the temperatures, B. antarctica accumulates trehalose, glucose. These compounds help the insect survive freezing by reducing the amount of ice that forms within the body and they also stabilize proteins and membranes, binding to them by means of hydrogen bonds. Heat shock proteins also help the tolerance to high and low temperatures. B. antarctica not only tolerates, but also requires a freezing climate to survive, exposure to temperatures of +30 °C kills individuals in a few hours. It can, however, resist partial desiccation, surviving the loss of up to 70% of body water, B. antarctica spends most of its two-year lifecycle in four larval stages. Overwintering may occur in any instar, terrestrial algae, particularly Prasiola crispa, moss, organic detritus, and microorganisms provide the food for the larval stage. The adults emerge in the spring and summer and live no more than 10 days, females mate in their first day of life, mating occurs in large groups of males, analogous to swarms of winged midges. Gynaephora groenlandica, a species of Arctic moth whose larvae can survive temperatures below -60 °C Wēkiu bug Data related to Belgica antarctica at Wikispecies
25.
Antarctic
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The Antarctic is a polar region, specifically the region around the Earths South Pole, opposite the Arctic region around the North Pole. The Antarctic comprises in the sense the continent of Antarctica. The region covers some 20% of the Southern Hemisphere, of which 5. 5% is the area of the Antarctic continent itself. All of the land and ice shelves south of 60°S latitude are administrated under the Antarctic Treaty System, in a biogeographic sense, the Antarctic ecozone is one of eight ecozones of the Earths land surface. Most of the Antarctic region is situated south of 60°S latitude parallel, there are only two species of flowering plant, Antarctic hair grass and Antarctic pearlwort, but a range of mosses, liverworts, lichens and macrofungi. The first Antarctic land discovered was the island of South Georgia, the first human born in the Antarctic was Solveig Gunbjørg Jacobsen born on 8 October 1913 in Grytviken, South Georgia. However, the region is visited by more than 40,000 tourists annually, the definitive results of the conference was presented at the Antarctic Treaty states meeting in Uruguay in May 2010. The Antarctic hosts the worlds largest protected area comprising 1.07 million km2, the South Georgia, because Antarctica surrounds the South Pole, it is theoretically located in all time zones. For practical purposes, time zones are based on territorial claims or the time zone of a stations owner country or supply base. Antarctic Circle History of Antarctica Krupnik, Igor, Michael A. Lang, smithsonian at the Poles, Contributions to International Polar Year Science
26.
Arthrobacter
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Arthrobacter is a genus of bacteria that is commonly found in soil. All species in this genus are Gram-positive obligate aerobes that are rods during exponential growth, Arthrobacter have a distinctive method of cell division called snapping division or reversion in which the outer bacterial cell wall ruptures at a joint. Arthrobacter can be grown on mineral salts pyridone broth, where colonies have a metallic center on incubated at 20 °C. Under the microscope, Arthrobacter appear as rods when rapidly dividing, dividing cells may also appear as chevrons. Other notable characteristics are that it can use pyridone as its carbon source. Arthrobacter, like other bacterial genre including Brevibacterium, Microbacterium, in industrial applications, Arthrobacter is often grown with low-cost sugar sources such as cane or beet molasses, starch hydrolysates from corn or cassava tubers, or tapioca. Along with sugar, ammonia and ammonium salts are added as a nitrogen source, the vitamins, minerals, and some other types of nutrients can be provided by adding corn steep liquour. Various Arthrobacter species have been investigated for other commercial applications, a. crystallopoietes and A. chlorophenolicus have been shown to reduce hexavalent chromium and 4-chlorophenol levels in contaminated soil, suggesting they may be useful for bioremediation. Arthrobacter sp H65-7 produces the enzyme inulase II that converts inulin into the medically-relevant nutrient difructose anhydride, the enzyme Alu obtained from Arthrobacter luteus is able to cleave Alu sequences which is frequently repeated in human DNA. Arthrobacter Genome Projects Comparative Analysis of Arthrobacter Genomes
27.
Pseudomonas
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Pseudomonas is a genus of Gram-negative, aerobic Gammaproteobacteria, belonging to the family Pseudomonadaceae and containing 191 validly described species. The members of the genus demonstrate a great deal of metabolic diversity, aeruginosa in its role as an opportunistic human pathogen, the plant pathogen P. syringae, the soil bacterium P. putida, and the plant growth-promoting P. fluorescens. Because of their occurrence in water and plant seeds such as dicots. Despite the vague description, the species, Pseudomonas pyocyanea. Like most bacterial genera, the pseudomonad last common ancestor lived hundreds of millions of years ago and they were initially classified at the end of the 19th century when first identified by Walter Migula. Soon, other species matching Migulas somewhat vague original description were isolated from many natural niches and, at the time, however, many strains have since been reclassified, based on more recent methodology and use of approaches involving studies of conservative macromolecules. Recently, 16S rRNA sequence analysis has redefined the taxonomy of many bacterial species, as a result, the genus Pseudomonas includes strains formerly classified in the genera Chryseomonas and Flavimonas. Other strains previously classified in the genus Pseudomonas are now classified in the genera Burkholderia and Ralstonia, certain Pseudomonas species may also produce additional types of siderophore, such as pyocyanin by Pseudomonas aeruginosa and thioquinolobactin by Pseudomonas fluorescens. Pseudomonas may be the most common nucleator of ice crystals in clouds, thereby being of utmost importance to the formation of snow, all species and strains of Pseudomonas have historically been classified as strict aerobes. Exceptions to this classification have recently discovered in Pseudomonas biofilms. A significant number of cells can produce exopolysaccharides associated with biofilm formation, secretion of exopolysaccharides such as alginate makes it difficult for pseudomonads to be phagocytosed by mammalian white blood cells. Exopolysaccharide production also contributes to surface-colonising biofilms that are difficult to remove from food preparation surfaces, growth of pseudomonads on spoiling foods can generate a fruity odor. Aminoglycosides such as tobramycin, gentamicin, and amikacin are other choices for therapy and this ability to thrive in harsh conditions is a result of their hardy cell walls that contain porins. Their resistance to most antibiotics is attributed to efflux pumps, which pump out some antibiotics before they are able to act, Pseudomonas aeruginosa is increasingly recognized as an emerging opportunistic pathogen of clinical relevance. One of its most worrying characteristics is its low antibiotic susceptibility, hypermutation favours the selection of mutation-driven antibiotic resistance in P. Although gallium has no function in biology, gallium ions interact with cellular processes in a manner similar to iron. When gallium ions are taken up in place of iron by bacteria such as Pseudomonas, the ions interfere with respiration. This happens because iron is redox-active, allowing the transfer of electrons during respiration and this situation sharply changed with the proposal to introduce as the central criterion the similarities in the composition and sequences of macromolecular components of the ribosomal RNA
28.
Penicillium
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Penicillium is a genus of ascomycetous fungi of major importance in the natural environment as well as food and drug production. Some members of the genus produce penicillin, a molecule that is used as an antibiotic, other species are used in cheesemaking. According to the Dictionary of the Fungi, the genus contains over 300 species. The genus was first described in the literature by Johann Heinrich Friedrich Link in his 1809 work Observationes in ordines plantarum naturales. Thallus e floccis caespitosis septatis simplicibus aut ramosis fertilibus erectis apice penicillatis, candidum, P. expansum, and P. glaucum—all of which produced a brush-like conidiophore. The common apple rot fungus P. expansum was selected as the type species, in a 1979 monograph, John I. Pitt divided Penicillium into four subgenera based on conidiophore morphology and branching pattern, Aspergilloides, Biverticillium, Furcatum, and Penicillium. The thallus typically consists of a branched network of multinucleate, septate. Many-branched conidiophores sprout on the mycelia, bearing individually constricted conidiospores, the conidiospores are the main dispersal route of the fungi, and often are green in color. Sexual reproduction involves the production of ascospores, commencing with the fusion of an archegonium, the irregularly distributed asci contain eight unicellular ascospores each. Species of Penicillium are ubiquitous soil fungi preferring cool and moderate climates, saprophytic species of Penicillium and Aspergillus are among the best-known representatives of the Eurotiales and live mainly on organic biodegradable substances. Commonly known in America as molds, they are among the causes of food spoilage. Many species produce highly toxic mycotoxins, some species have a blue color, commonly growing on old bread and giving it a blue fuzzy texture. Some Penicillium species affect the fruits and bulbs of plants, including P. expansum, apples and pears, P. digitatum, citrus fruits, and P. allii, garlic. Some species are known to be pathogenic to animals, P. corylophilum, P. fellutanum, P. implicatum, P. janthinellum, P. viridicatum, and P. waksmanii are potential pathogens of mosquitoes. P. marneffei, which causes mortality in the Vietnamese bamboo rats, has become a common infection of HIV-infected individuals in southeast Asia. Penicillium species are present in the air and dust of indoor environments, such as homes, the fungus can be readily transported from the outdoors, and grow indoors using building material or accumulated soil to obtain nutrients for growth. Penicillium growth can occur indoors even if the relative humidity is low. A British study determined that Aspergillus- and Penicillium-type spores were the most prevalent in the air of residential properties
29.
Grylloblattidae
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Grylloblattidae is a family of extremophile and wingless insects that live in the cold on top of mountains. It belongs, along with Mantophasmatidae, to the order Notoptera and they are commonly called grylloblattids, but are also sometimes called ice crawlers or icebugs. Most are nocturnal and appear to feed on detritus and they have long antennae and long cerci, but no wings. Their eyes are missing or reduced and they have no ocelli. Their closest living relatives are the recently discovered Mantophasmatodea, the family is placed in its own suborder, Grylloblattodea, and in its own former order, Grylloblattaria. It contains 5 genera and 34 species, Grylloblattodea are nocturnal extremophiles typically found in leaf litter and under stones in extremely cold environments, usually at higher elevations. They are known to inhabit temperate forests to glaciers and ice sheets. Their optimal living temperature is between 1-4 °C and they can be killed at colder temperatures due to ice formation in the body, so when the temperature drops below their optimal range they survive by living under snow pack near the soil. They are omnivorous, but feed primarily on deceased arthropods, when arthropod carcasses are scarce, their diet relies heavily on plant material. Media related to Grylloblattidae at Wikimedia Commons Data related to Grylloblattidae at Wikispecies Video of a walking grylloblattid
30.
Endemism
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The extreme opposite of endemism is cosmopolitan distribution. An alternative term for a species that is endemic is precinctive, the word endemic is from New Latin endēmicus, from Greek ενδήμος, endēmos, native. Endēmos is formed of en meaning in, and dēmos meaning the people, the term, precinctive, has been suggested by some scientists, and was first used in botany by MacCaughey in 1917. It is the equivalent of endemism, precinction was perhaps first used by Frank and McCoy. That definition excludes artificial confinement of examples by humans in far-off botanical gardens or zoological parks, physical, climatic, and biological factors can contribute to endemism. The orange-breasted sunbird is found in the fynbos vegetation zone of southwestern South Africa. The glacier bear is found only in limited places in Southeast Alaska, political factors can play a part if a species is protected, or actively hunted, in one jurisdiction but not another. There are two subcategories of endemism, paleoendemism and neoendemism, paleoendemism refers to species that were formerly widespread but are now restricted to a smaller area. Neoendemism refers to species that have arisen, such as through divergence and reproductive isolation or through hybridization. Endemics can easily become endangered or extinct if their restricted habitat changes, particularly—but not only—due to human actions, there were millions of both Bermuda petrels and Bermuda cedars in Bermuda when it was settled at the start of the seventeenth century. By the end of the century, the petrels were thought extinct, cedars, already ravaged by centuries of shipbuilding, were driven nearly to extinction in the twentieth century by the introduction of a parasite. Bermuda petrels and cedars are now rare, as are species endemic to Bermuda
31.
Antarctica
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It contains the geographic South Pole and is situated in the Antarctic region of the Southern Hemisphere, almost entirely south of the Antarctic Circle, and is surrounded by the Southern Ocean. At 14,000,000 square kilometres, it is the fifth-largest continent, for comparison, Antarctica is nearly twice the size of Australia. About 98% of Antarctica is covered by ice that averages 1.9 km in thickness, Antarctica, on average, is the coldest, driest, and windiest continent, and has the highest average elevation of all the continents. Antarctica is a desert, with precipitation of only 200 mm along the coast. The temperature in Antarctica has reached −89.2 °C, though the average for the quarter is −63 °C. Anywhere from 1,000 to 5,000 people reside throughout the year at the research stations scattered across the continent. Organisms native to Antarctica include many types of algae, bacteria, fungi, plants, protista, vegetation, where it occurs, is tundra. The continent, however, remained neglected for the rest of the 19th century because of its hostile environment, lack of easily accessible resources. In 1895, the first confirmed landing was conducted by a team of Norwegians, Antarctica is a de facto condominium, governed by parties to the Antarctic Treaty System that have consulting status. Twelve countries signed the Antarctic Treaty in 1959, and thirty-eight have signed it since then, the treaty prohibits military activities and mineral mining, prohibits nuclear explosions and nuclear waste disposal, supports scientific research, and protects the continents ecozone. Ongoing experiments are conducted by more than 4,000 scientists from many nations, the name Antarctica is the romanised version of the Greek compound word ἀνταρκτική, feminine of ἀνταρκτικός, meaning opposite to the Arctic, opposite to the north. Aristotle wrote in his book Meteorology about an Antarctic region in c.350 B. C, marinus of Tyre reportedly used the name in his unpreserved world map from the 2nd century A. D. Before acquiring its present geographical connotations, the term was used for locations that could be defined as opposite to the north. For example, the short-lived French colony established in Brazil in the 16th century was called France Antarctique, the first formal use of the name Antarctica as a continental name in the 1890s is attributed to the Scottish cartographer John George Bartholomew. Antarctica has no population and there is no evidence that it was seen by humans until the 19th century. Explorer Matthew Flinders, in particular, has credited with popularising the transfer of the name Terra Australis to Australia. Cook came within about 120 km of the Antarctic coast before retreating in the face of ice in January 1773. The first confirmed sighting of Antarctica can be narrowed down to the crews of ships captained by three individuals, according to various organisations, ships captained by three men sighted Antarctica or its ice shelf in 1820, von Bellingshausen, Edward Bransfield, and Nathaniel Palmer
32.
Genome
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In modern molecular biology and genetics, a genome is the genetic material of an organism. The genome includes both the genes, the noncoding DNA and the material of the mitochondria and chloroplasts. The term genome was created in 1920 by Hans Winkler, professor of botany at the University of Hamburg, the Oxford Dictionary suggests the name is a blend of the words gene and chromosome. However, see omics for a thorough discussion. A few related -ome words already existed—such as biome, rhizome, Some organisms have multiple copies of chromosomes, diploid, triploid, tetraploid and so on. In classical genetics, in a sexually reproducing organism the gamete has half the number of chromosomes of the somatic cell, the halving of the genetic material in gametes is accomplished by the segregation of homologous chromosomes during meiosis. Additionally, the genome can comprise non-chromosomal genetic elements such as viruses, plasmids, even in species that exist in only one sex, what is described as a genome sequence may be a composite read from the chromosomes of various individuals. Colloquially, the genetic makeup is sometimes used to signify the genome of a particular individual or organism. Both the number of pairs and the number of genes vary widely from one species to another. The only exception in humans is found in red blood cells which become enucleated during development. In 1976, Walter Fiers at the University of Ghent was the first to establish the complete sequence of a viral RNA-genome. The next year Fred Sanger completed the first DNA-genome sequence, Phage Φ-X174, the first genome sequence for an archaeon, Methanococcus jannaschii, was completed in 1996, again by The Institute for Genomic Research. The development of new technologies has made it easier and cheaper to do sequencing. The US National Institutes of Health maintains one of several databases of genomic information. Among the thousands of completed genome sequencing projects include those for rice, a mouse, the plant Arabidopsis thaliana, the fish. In December 2013, scientists first sequenced the genome of a Neanderthal. The genome was extracted from the toe bone of a 130, new sequencing technologies, such as massive parallel sequencing have also opened up the prospect of personal genome sequencing as a diagnostic tool, as pioneered by Manteia Predictive Medicine. A major step toward that goal was the completion in 2007 of the genome of James D. Watson
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Base pair
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A base pair is a unit consisting of two nucleobases bound to each other by hydrogen bonds. They form the blocks of the DNA double helix. Dictated by specific hydrogen bonding patterns, Watson-Crick base pairs allow the DNA helix to maintain a regular helical structure that is dependent on its nucleotide sequence. The complementary nature of this structure provides a backup copy of all genetic information encoded within double-stranded DNA. Many DNA-binding proteins can recognize specific base pairing patterns that identify particular regulatory regions of genes, intramolecular base pairs can occur within single-stranded nucleic acids. The size of a gene or an organisms entire genome is often measured in base pairs because DNA is usually double-stranded. Hence, the number of base pairs is equal to the number of nucleotides in one of the strands. The haploid human genome is estimated to be about 3.2 billion bases long and to contain 20, a kilobase is a unit of measurement in molecular biology equal to 1000 base pairs of DNA or RNA. The total amount of related DNA base pairs on Earth is estimated at 5.0 x 1037, in comparison, the total mass of the biosphere has been estimated to be as much as 4 TtC. Hydrogen bonding is the interaction that underlies the base-pairing rules described above. Appropriate geometrical correspondence of hydrogen donors and acceptors allows only the right pairs to form stably. Purine-pyrimidine base pairing of AT or GC or UA results in proper duplex structure, the only other purine-pyrimidine pairings would be AC and GT and UG, these pairings are mismatches because the patterns of hydrogen donors and acceptors do not correspond. The GU pairing, with two bonds, does occur fairly often in RNA. Higher GC content results in higher melting temperatures, it is, therefore, on the converse, regions of a genome that need to separate frequently — for example, the promoter regions for often-transcribed genes — are comparatively GC-poor. GC content and melting temperature must also be taken into account when designing primers for PCR reactions, the following DNA sequences illustrate pair double-stranded patterns. By convention, the top strand is written from the 5 end to the 3 end, thus and this is due to their isosteric chemistry. One common mutagenic base analog is 5-bromouracil, which resembles thymine, most intercalators are large polyaromatic compounds and are known or suspected carcinogens. Examples include ethidium bromide and acridine, an unnatural base pair is a designed subunit of DNA which is created in a laboratory and does not occur in nature
34.
Refrigeration
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Refrigeration is a process of moving heat from one location to another in controlled conditions. The work of heat transport is driven by mechanical work. Refrigeration has many applications, including, but not limited to, household refrigerators, industrial freezers, cryogenics, heat pumps may use the heat output of the refrigeration process, and also may be designed to be reversible, but are otherwise similar to air conditioning units. Refrigeration has had a impact on industry, lifestyle, agriculture. The idea of preserving food dates back to at least the ancient Roman, however, mechanical refrigeration technology has rapidly evolved in the last century, from ice harvesting to temperature-controlled rail cars. Settlements were also developing in parts of the country, filled with new natural resources. These new settlement patterns sparked the building of cities which are able to thrive in areas that were otherwise thought to be inhospitable, such as Houston, Texas and Las Vegas. In most developed countries, cities are heavily dependent upon refrigeration in supermarkets, the increase in food sources has led to a larger concentration of agricultural sales coming from a smaller percentage of existing farms. Farms today have a larger output per person in comparison to the late 1800s. This has resulted in new food sources available to entire populations, the seasonal harvesting of snow and ice is an ancient practice estimated to have begun earlier than 1000 B. C. A Chinese collection of lyrics from this period known as the Shih king. However, little is known about the construction of these ice cellars or what the ice was used for. ”Historians have interpreted this to mean that the Jews used ice to cool beverages rather than to preserve food. Other ancient cultures such as the Greeks and the Romans dug large snow pits insulated with grass, chaff, like the Jews, the Greeks and Romans did not use ice and snow to preserve food, but primarily as a means to cool beverages. Slaves would moisten the outside of the jars and the resulting evaporation would cool the water, the ancient people of India used this same concept to produce ice. The Persians stored ice in a pit called a Yakhchal and may have been the first group of people to use storage to preserve food. In the Australian outback before a reliable electricity supply was available where the weather could be hot and dry and this consisted of a room with hessian curtains hanging from the ceiling soaked in water. The water would evaporate and thereby cool the hessian curtains and thereby the air circulating in the room and this would allow many perishables such as fruit, butter, and cured meats to be kept that would normally spoil in the heat. Before 1830, few Americans used ice to refrigerate foods due to a lack of ice-storehouses and iceboxes, as these two things became more widely available, individuals used axes and saws to harvest ice for their storehouses
35.
Dairy
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A dairy is a business enterprise established for the harvesting or processing of animal milk – mostly from cows or goats, but also from buffaloes, sheep, horses, or camels – for human consumption. A dairy is located on a dedicated dairy farm or in a section of a multi-purpose farm that is concerned with the harvesting of milk. For example, in the United States, the dairy farm is commonly called a dairy. The building or farm area where milk is harvested from the cow is called a milking parlor or parlor. The farm area where milk is stored in tanks is known as the farms milk house. Milk is then hauled to a plant, also referred to as a dairy. In New Zealand, farm areas for milk harvesting are also called milking parlours, as in the United States, sometimes milking sheds are referred to by their type, such as herring bone shed or pit parlour. Parlour design has evolved from simple barns or sheds to large structures in which the workflow is very efficiently handled. This on-site processing is a method of producing specialist milk products. In New Zealand English the singular use of the word dairy almost exclusively refers to a corner shop and this usage is historical as such shops were a common place for the public to buy milk products. As an attributive, the word refers to milk-based products, derivatives and processes. A dairy farm produces milk and a dairy factory processes it into a variety of dairy products and these establishments constitute the global dairy industry, a component of the food industry. Milk producing animals have been domesticated for thousands of years, initially, they were part of the subsistence farming that nomads engaged in. As the community moved about the country, their animals accompanied them, protecting and feeding the animals were a big part of the symbiotic relationship between the animals and the herders. In the more recent past, people in agricultural societies owned dairy animals that they milked for domestic and local consumption, the animals might serve multiple purposes. In this case the animals were normally milked by hand and the size was quite small. These tasks were performed by a dairymaid or dairyman, the word dairy harkens back to Middle English dayerie, deyerie, from deye and further back to Old English dæge. With industrialisation and urbanisation, the supply of milk became an industry, with specialised breeds of cattle being developed for dairy
36.
Pasteurization
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Pasteurization or pasteurisation is a process that kills microbes in food and drink, such as milk, juice, canned food, and others. It was invented by French scientist Louis Pasteur during the nineteenth century, in 1864 Pasteur discovered that heating beer and wine was enough to kill most of the bacteria that caused spoilage, preventing these beverages from turning sour. The process achieves this by eliminating pathogenic microbes and lowering microbial numbers to prolong the quality of the beverage, today, pasteurization is used widely in the dairy industry and other food processing industries to achieve food preservation and food safety. Unlike sterilization, pasteurization is not intended to kill all microorganisms in the food, instead, it aims to reduce the number of viable pathogens so they are unlikely to cause disease. Commercial-scale sterilization of food is not common because it affects the taste. Certain foods, such as products, may be superheated to ensure pathogenic microbes are destroyed. The process of heating wine for preservation purposes has been known in China since 1117, much later, in 1768, an Italian priest and scientist Lazzaro Spallanzani proved experimentally that heat killed bacteria, and that they do not reappear if the product is hermetically sealed. He placed the food in glass jars, sealed them with cork and sealing wax, in that same year, the French military offered a cash prize of 12,000 francs for a new method to preserve food. After some 14 or 15 years of experimenting, Appert submitted his invention and won the prize in January 1810, later that year, Appert published LArt de conserver les substances animales et végétales. This was the first cookbook of its kind on modern food preservation methods, la Maison Appert, in the town of Massy, near Paris, became the first food-bottling factory in the world, preserving a variety of food in sealed bottles. Apperts method was to fill thick, large-mouthed glass bottles with produce of every description, ranging from beef and fowl to eggs, milk and his greatest success for publicity was an entire sheep. He left air space at the top of the bottle, the bottle was then wrapped in canvas to protect it, while it was dunked into boiling water and then boiled for as much time as Appert deemed appropriate for cooking the contents thoroughly. Appert patented his method, sometimes called appertisation, in his honor, Apperts method was so simple and workable that it quickly became widespread. In 1810, British inventor and merchant Peter Durand, also of French origin, patented his own method, in 1812, Englishmen Bryan Donkin and John Hall purchased both patents and began producing preserves. Just a decade later, Apperts method of canning had made its way to America, Apperts preservation by boiling involved heating the food to an unnecessarily high temperature, and for an unnecessarily long time, which could destroy some of the flavor of the preserved food. A less aggressive method was developed by the French chemist Louis Pasteur during an 1864 summer holiday in Arbois, in honour of Pasteur, the process became known as pasteurization. Pasteurization was originally used as a way of preventing wine and beer from souring, in the United States in the 1870s, it was common for milk to contain substances intended to mask spoilage before milk was regulated. Milk is an excellent medium for growth, and when stored at ambient temperature bacteria
37.
Pseudomonas syringae
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Pseudomonas syringae is a rod-shaped, Gram-negative bacterium with polar flagella. Whether these pathovars represent a species is unclear. P. syringae is a member of the Pseudomonas genus, and based on 16S rRNA analysis and it is named after the lilac tree, from which it was first isolated. P. syringae tests negative for arginine dihydrolase and oxidase activity, P. syringae also produces ice nucleation active proteins which cause water to freeze at fairly high temperatures, resulting in injury. Since the 1970s, P. syringae has been implicated as an atmospheric biological ice nucleator, recent evidence has suggested the species plays a larger role than previously thought in producing rain and snow. They have also found in the cores of hailstones, aiding in bioprecipitation. These INA proteins are used in making artificial snow. P. syringae pathogenesis is dependent on effector proteins secreted into the plant cell by the bacterial type III secretion system, nearly 60 different type III effector families encoded by hop genes have been identified in P. syringae. Type III effectors contribute to pathogenesis chiefly through their role in suppressing plant defense, a surprise frost occurred that year, leaving peculiar results. Only plants infected with the diseased powder incurred frost damage, leaving healthy plants unfrozen and this phenomenon baffled scientists until graduate student Stephen Lindow of the University of Wisconsin–Madison with D. C. Upper found a bacterium in the leaf powder in the early 1970s. He went on to identify the bacterium as P. syringae, investigate P. syringaes role in ice nucleation and in 1977 and he was later successful at developing the ice-minus strain of P. syringae through recombinant DNA technology, as well. Disease by P. syringae tends to be favoured by wet, cool conditions—optimum temperatures for disease tend to be around 12–25°C, the bacteria tend to be seed-borne, and are dispersed between plants by rain splash. Although it is a plant pathogen, it can live as a saprotroph in the phyllosphere when conditions are not favourable for disease. Some saprotrophic strains of P. syringae have been used as agents against postharvest rots. The mechanisms of P. Planktonic P. syringae is able to enter plants using its flagella and it enters the plant via wounds of natural opening sites, as it is not able to breach the plant cell wall. The role of taxis in P. syringae has not been well-studied, P. syringae isolates carry a range of virulence factors called type III secretion system effector proteins. These proteins primarily function to disease symptoms and manipulate the hosts immune response to facilitate infection
38.
Halophile
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Halophiles are organisms that thrive in high salt concentrations. They are a type of extremophile organisms, the name comes from the Greek word for salt-loving. While most halophiles are classified into the Archaea domain, there are also bacterial halophiles and some eukaryota, some well-known species give off a red color from carotenoid compounds, notably bacteriorhodopsin. Halophiles are categorized as slight, moderate, or extreme, by the extent of their halotolerance. Slight halophiles prefer 0.3 to 0.8 M, moderate halophiles 0.8 to 3.4 M, halophiles require sodium chloride for growth, in contrast to halotolerant organisms, which do not require salt but can grow under saline conditions. High salinity represents an environment to which relatively few organisms have been able to adapt. Most halophilic and all halotolerant organisms expend energy to exclude salt from their cytoplasm to avoid protein aggregation, to survive the high salinities, halophiles employ two differing strategies to prevent desiccation through osmotic movement of water out of their cytoplasm. Both strategies work by increasing the osmolarity of the cell. In the first, organic compounds are accumulated in the cytoplasm — osmoprotectants which are known as compatible solutes and these can be either synthesised or accumulated from the environment. The most common compatible solutes are neutral or zwitterionic, and include amino acids, sugars, polyols, betaines, the second, more radical, adaptation involves the selective influx of potassium ions into the cytoplasm. Of particular note are the extreme halophiles or haloarchaea, a group of archaea and these are the primary inhabitants of salt lakes, inland seas, and evaporating ponds of seawater, such as the deep salterns, where they tint the water column and sediments bright colors. These species most likely if they are exposed to anything other than a very high-concentration. These prokaryotes require salt for growth, the high concentration of sodium chloride in their environment limits the availability of oxygen for respiration. Their cellular machinery is adapted to high concentrations by having charged amino acids on their surfaces. They are heterotrophs that normally respire by aerobic means, most halophiles are unable to survive outside their high-salt native environments. Indeed, many cells are so fragile that when placed in distilled water, halophiles may use a variety of energy sources. They can be aerobic or anaerobic, anaerobic halophiles include phototrophic, fermentative, sulfate-reducing, homoacetogenic, and methanogenic species. The Haloarchaea, and particularly the family Halobacteriaceae, are members of the domain Archaea, currently,15 recognised genera are in the family
39.
PubMed Identifier
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PubMed is a free search engine accessing primarily the MEDLINE database of references and abstracts on life sciences and biomedical topics. The United States National Library of Medicine at the National Institutes of Health maintains the database as part of the Entrez system of information retrieval, from 1971 to 1997, MEDLINE online access to the MEDLARS Online computerized database primarily had been through institutional facilities, such as university libraries. PubMed, first released in January 1996, ushered in the era of private, free, home-, the PubMed system was offered free to the public in June 1997, when MEDLINE searches via the Web were demonstrated, in a ceremony, by Vice President Al Gore. Information about the journals indexed in MEDLINE, and available through PubMed, is found in the NLM Catalog. As of 5 January 2017, PubMed has more than 26.8 million records going back to 1966, selectively to the year 1865, and very selectively to 1809, about 500,000 new records are added each year. As of the date,13.1 million of PubMeds records are listed with their abstracts. In 2016, NLM changed the system so that publishers will be able to directly correct typos. Simple searches on PubMed can be carried out by entering key aspects of a subject into PubMeds search window, when a journal article is indexed, numerous article parameters are extracted and stored as structured information. Such parameters are, Article Type, Secondary identifiers, Language, publication type parameter enables many special features. As these clinical girish can generate small sets of robust studies with considerable precision, since July 2005, the MEDLINE article indexing process extracts important identifiers from the article abstract and puts those in a field called Secondary Identifier. The secondary identifier field is to store numbers to various databases of molecular sequence data, gene expression or chemical compounds. For clinical trials, PubMed extracts trial IDs for the two largest trial registries, ClinicalTrials. gov and the International Standard Randomized Controlled Trial Number Register, a reference which is judged particularly relevant can be marked and related articles can be identified. If relevant, several studies can be selected and related articles to all of them can be generated using the Find related data option, the related articles are then listed in order of relatedness. To create these lists of related articles, PubMed compares words from the title and abstract of each citation, as well as the MeSH headings assigned, using a powerful word-weighted algorithm. The related articles function has been judged to be so precise that some researchers suggest it can be used instead of a full search, a strong feature of PubMed is its ability to automatically link to MeSH terms and subheadings. Examples would be, bad breath links to halitosis, heart attack to myocardial infarction, where appropriate, these MeSH terms are automatically expanded, that is, include more specific terms. Terms like nursing are automatically linked to Nursing or Nursing and this important feature makes PubMed searches automatically more sensitive and avoids false-negative hits by compensating for the diversity of medical terminology. The My NCBI area can be accessed from any computer with web-access, an earlier version of My NCBI was called PubMed Cubby
. PMID 16585939.