1.
Taxonomy (biology)
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Taxonomy is the science of defining groups of biological organisms on the basis of shared characteristics and giving names to those groups. The exact definition of taxonomy varies from source to source, but the core of the remains, the conception, naming. There is some disagreement as to whether biological nomenclature is considered a part of taxonomy, the broadest meaning of taxonomy is used here. The word taxonomy was introduced in 1813 by Candolle, in his Théorie élémentaire de la botanique, the term alpha taxonomy is primarily used today to refer to the discipline of finding, describing, and naming taxa, particularly species. In earlier literature, the term had a different meaning, referring to morphological taxonomy, ideals can, it may be said, never be completely realized. They have, however, a value of acting as permanent stimulants. Some of us please ourselves by thinking we are now groping in a beta taxonomy, turrill thus explicitly excludes from alpha taxonomy various areas of study that he includes within taxonomy as a whole, such as ecology, physiology, genetics, and cytology. He further excludes phylogenetic reconstruction from alpha taxonomy, thus, Ernst Mayr in 1968 defined beta taxonomy as the classification of ranks higher than species. This activity is what the term denotes, it is also referred to as beta taxonomy. How species should be defined in a group of organisms gives rise to practical and theoretical problems that are referred to as the species problem. The scientific work of deciding how to define species has been called microtaxonomy, by extension, macrotaxonomy is the study of groups at higher taxonomic ranks, from subgenus and above only, than species. While some descriptions of taxonomic history attempt to date taxonomy to ancient civilizations, earlier works were primarily descriptive, and focused on plants that were useful in agriculture or medicine. There are a number of stages in scientific thinking. Early taxonomy was based on criteria, the so-called artificial systems. Later came systems based on a complete consideration of the characteristics of taxa, referred to as natural systems, such as those of de Jussieu, de Candolle and Bentham. The publication of Charles Darwins Origin of Species led to new ways of thinking about classification based on evolutionary relationships and this was the concept of phyletic systems, from 1883 onwards. This approach was typified by those of Eichler and Engler, the advent of molecular genetics and statistical methodology allowed the creation of the modern era of phylogenetic systems based on cladistics, rather than morphology alone. Taxonomy has been called the worlds oldest profession, and naming and classifying our surroundings has likely been taking place as long as mankind has been able to communicate
2.
Tick
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Ticks are small arachnids, part of the order Parasitiformes. Along with mites, they constitute the subclass Acari, Ticks are ectoparasites, living by feeding on the blood of mammals, birds, and sometimes reptiles and amphibians. Ticks had evolved by the Cretaceous period, the most common form of fossilisation being immersed in amber, Ticks are widely distributed around the world, especially in warm, humid climates. Almost all ticks belong to one of two families, the Ixodidae or hard ticks, which are difficult to crush. Adults have ovoid or pear-shaped bodies which become engorged with blood when they feed, both families locate a potential host by odour or from changes in the environment. Ticks have four stages to their lifecycle, namely egg, larva, nymph, ixodid ticks have three hosts, taking at least a year to complete their lifecycle. Argasid ticks have up to seven stages, each one requiring a blood meal. Because of their habit of ingesting blood, ticks are vectors of at least twelve diseases that affect humans, fossilized ticks are known from the Cretaceous onwards, most commonly in amber. They most likely originated in the Cretaceous, with most of the evolution, the oldest example is an argasid bird tick from Cretaceous New Jersey amber. The younger Baltic and Dominican ambers have also yielded examples which can be placed in living genera, there are three families of ticks. The two large ones are the families of Ixodidae and Argasidae. The third is Nuttalliellidae, named for the bacteriologist George Nuttall and it comprises a single species, Nuttalliella namaqua, and is the most basal lineage. Ticks are closely related to the mites, within the subclass Acarina, RDNA analysis suggests that the Ixodidae are a clade, but that the Argasidae may be paraphyletic. The Ixodidae contains over 700 species of ticks with a scutum or hard shield. The Argasidae contains about 200 species, the genera accepted as of 2010 are Antricola, Argas, Nothoaspis, Ornithodoros and they have no scutum, and the capitulum is concealed beneath the body. The family Nuttalliellidae contains only a species, Nuttalliella namaqua. The phylogeny of the Ixodida within the Acari is shown in the cladogram, the Argasidae appear monophyletic in this study. Ticks are also distributed among host taxa, which include marsupial and placental mammals, birds, reptiles such as snakes, iguanas and lizards
3.
Air filter
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A particulate air filter is a device composed of fibrous materials which removes solid particulates such as dust, pollen, mould, and bacteria from the air. Filters containing an absorbent or catalyst such as charcoal may also remove odors, air filters are used in applications where air quality is important, notably in building ventilation systems and in engines. Some buildings, as well as aircraft and other human-made environments use foam, pleated paper, another method, air ionisers, use fibers or elements with a static electric charge, which attract dust particles. The air intakes of internal combustion engines and air compressors tend to use paper, foam. Oil bath filters have fallen out of favor, the cabin air filter is typically a pleated-paper filter that is placed in the outside-air intake for the vehicles passenger compartment. Some of these filters are rectangular and similar in shape to the air filter. Others are uniquely shaped to fit the space of particular vehicles outside-air intakes. The first automaker to include a disposable filter to clean the system was the Nash Motors Weather Eye. Being a relatively recent addition to equipment, this filter is often overlooked. Clogged or dirty cabin air filters can significantly reduce airflow from the cabin vents, the poor performance of these filters is obscured by manufacturers by not using the MERV rating system. Some people mistakenly believe that some of these are HEPA filters, the combustion air filter prevents abrasive particulate matter from entering the engines cylinders, where it would cause mechanical wear and oil contamination. Most fuel injected vehicles use a paper filter element in the form of a flat panel. This filter is placed inside a plastic box connected to the throttle body with ductwork. Older vehicles that use carburetors or throttle body fuel injection typically use an air filter, usually a few inches high. The overall unit is called the air cleaner, pleated paper filter elements are the nearly exclusive choice for automobile engine air cleaners, because they are efficient, easy to service, and cost-effective. The paper term is misleading, as the filter media are considerably different from papers used for writing or packaging. There is a persistent belief amongst tuners, fomented by advertising for aftermarket non-paper replacement filters, construction equipment engines also use this. Oil-wetted polyurethane foam elements are used in some aftermarket replacement automobile air filters, foam filters are still commonly used on air compressors for air tools up to 5Hp
4.
Hideyo Noguchi
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Hideyo Noguchi, also known as Seisaku Noguchi, was a prominent Japanese bacteriologist who in 1911 discovered the agent of syphilis as the cause of progressive paralytic disease. Noguchi Hideyo was born in Inawashiro, Fukushima prefecture in 1876, when he was one and a half years old, he fell into a fireplace and suffered a burn injury on his left hand. There was no doctor in the village, but one of the men examined the boy. The fingers of the hand are mostly gone, he said, and the left arm, the left foot. In 1883, Noguchi entered Mitsuwa elementary school, thanks to generous contributions from his teacher Kobayashi and his friends, he was able to receive surgery on his badly burned hand. He recovered about 70% mobility and functionality in his hand through the operation. Noguchi decided to become a doctor to help those in need and he apprenticed himself to Dr. Kanae Watanabe, the same doctor who had performed the surgery. He entered Saisei Gakusha, which later became Nippon Medical School and he passed the examinations to practice medicine when he was twenty years old in 1897. He showed signs of talent and was supported in his studies by Dr. Morinosuke Chiwaki. In 1898, he changed his first name to Hideyo after reading a novel about a doctor who had the same name—Seisaku—as him, the doctor in the story was intelligent like Noguchi but became lazy and ruined his life. At this time his work concerned venomous snakes, in part, his move was motivated by difficulties in obtaining a medical position in Japan, as prospective employers were concerned that his hand deformity would discourage potential patients. In a research setting, he did not have a handicap and he and his peers learned from their work and from each other. In this period, a research assistant in Flexners lab was Frenchman Alexis Carrel. Noguchis work later attracted the Prize committees scrutiny, in the 21st century, the Nobel Foundation archives were opened for public inspection and research. Historians found that Noguchi was nominated several times for the Nobel Prize in Physiology or Medicine, in 1913-1915,1920,1921, during the 1920s, his work was being increasingly criticized for inaccuracies. While working at the Rockefeller Institute of Medical Research in 1911 and he was acquitted of any wrongdoing at the time but, since the late 20th century, his conduct of the study has come to be considered an early instance of unethical human experimentation. At the time, society had not developed a consensus about how to conduct human experimentation, antivivisectionists linked their concerns for animals with concerns about humans. The American Society for the Prevention of Cruelty to Children was founded in the late 19th century after the American Society for the Prevention of Cruelty to Animals
5.
Frank Macfarlane Burnet
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Sir Frank Macfarlane Burnet, OM AK KBE FRS FAA FRSNZ, usually known as Macfarlane or Mac Burnet, was an Australian virologist best known for his contributions to immunology. He won the Nobel Prize in 1960 for predicting acquired immune tolerance and was best known for developing the theory of clonal selection, Burnet received his Doctor of Medicine degree from the University of Melbourne in 1924, and his PhD from the University of London in 1928. From 1965 until his retirement in 1978, Burnet worked at the University of Melbourne, modern methods for producing influenza vaccines are still based on Burnets work improving virus growing processes in hens eggs. Burnet was the most highly decorated and honoured scientist to have worked in Australia, for his contributions to Australian science, he was made the first Australian of the Year in 1960, and in 1978 a Knight of the Order of Australia. After a series of increasing problems in his final years. Burnet was born in Traralgon, Victoria, his father, Frank Burnet and his mother Hadassah Burnet was the daughter of a middle-class Scottish immigrant, and met his father when Frank was working in the town of Koroit. Frank was 36, and 14 years older than Hadassah when they married in 1893, the family was socially conservative Anglo-Saxon Protestant. Frank Macfarlane Burnet was the second of seven children and from childhood was known as Mac and he had an older sister, two younger sisters and three younger brothers. From his early years in Traralgon, Mac enjoyed exploring the environment around him and he first attended a private school run by a single teacher before starting at the government primary school at the age of 7. Mac was distant from his father—who liked to spend his time fishing and playing golf—from a young age. Hadassah was preoccupied with Doris, so Mac developed a rather solitary personality, the Burnets moved to Terang in 1909, when Frank was posted to be the bank manager there, having declined a post in London. Burnet was interested in the wildlife around the lake, he joined the Scouts in 1910. While living in Terang, he began to collect beetles and study biology and he read biology articles in the Chamberss Encyclopaedia, which introduced him to the work of Charles Darwin. During his early teens, the family took annual holidays to Port Fairy and he advised Frank to invest in Macs education and he won a full scholarship to board and study at Geelong College, one of Victorias most exclusive private schools. Starting there in 1913, Burnet was the only boarder with a full scholarship, during this period he kept his beetle-collecting and disapproval of his peers a secret and mixed with his schoolmates out of necessity. Nevertheless, his academic prowess gained him privileges, and he graduated in 1916, placing first in his school overall, the typical university path for a person of his social background was to pursue studies in theology, law or medicine. By this time, he was becoming disillusioned with religion and chose medicine, due to World War I, military service was a possibility and he felt that a medical background would increase his chances of being given a non-combat post. From 1918, Burnet attended the University of Melbourne, where he lived in Ormond College on a residential scholarship, there, he read more of Darwins work and was influenced by the ideas of science and society in the writings of H. G. Wells
6.
Biological warfare
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Biological weapons are living organisms or replicating entities that reproduce or replicate within their host victims. Entomological warfare is considered a type of biological weapon. None of these are conventional weapons, which are deployed primarily for their explosive, kinetic, Biological weapons may be employed in various ways to gain a strategic or tactical advantage over the enemy, either by threats or by actual deployments. Like some of the weapons, biological weapons may also be useful as area denial weapons. These agents may be lethal or non-lethal, and may be targeted against a single individual and they may be developed, acquired, stockpiled or deployed by nation states or by non-national groups. In the latter case, or if a nation-state uses it clandestinely, toxins and psychochemical weapons are often referred to as midspectrum agents. Unlike bioweapons, these agents do not reproduce in their host and are typically characterized by shorter incubation periods. Offensive biological warfare, including production, stockpiling and use of biological weapons, was outlawed by the 1972 Biological Weapons Convention. Many countries, including signatories of the BWC, currently pursue research into the defense or protection against BW, a nation or group that can pose a credible threat of mass casualty has the ability to alter the terms on which other nations or groups interact with it. Therefore, biological agents may be useful as strategic deterrents in addition to their utility as offensive weapons on the battlefield. As a tactical weapon for use, a significant problem with a BW attack is that it would take days to be effective. Some biological agents have the capability of person-to-person transmission via aerosolized respiratory droplets and this feature can be undesirable, as the agent may be transmitted by this mechanism to unintended populations, including neutral or even friendly forces. While containment of BW is less of a concern for criminal or terrorist organizations, it remains a significant concern for the military. Rudimentary forms of warfare have been practiced since antiquity. During the 6th century BC, the Assyrians poisoned enemy wells with a fungus that would render the enemy delirious, in 1346, the bodies of Mongol warriors of the Golden Horde who had died of plague were thrown over the walls of the besieged Crimean city of Kaffa. Specialists disagree over whether this operation may have been responsible for the spread of the Black Death into Europe, the British Army used smallpox against Native Americans during the Siege of Fort Pitt in 1763. An outbreak that left as many as one hundred Native Americans dead in Ohio Country was reported in 1764, the spread of the disease weakened the natives resistance to the British troops led by Henry Bouquet. It is not clear, however, whether the smallpox was a result of the Fort Pitt incident or the virus was present among the Delaware people
7.
Endosome
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In cell biology, an endosome is a membrane-bound compartment inside eukaryotic cells. It is a compartment of the membrane transport pathway originating from the trans Golgi membrane. Molecules or ligands internalized from the membrane can follow this pathway all the way to lysosomes for degradation. Molecules are also transported to endosomes from the network and either continue to lysosomes or recycle back to the Golgi. Endosomes can be classified as early, sorting, or late depending on their stage post internalization, endosomes represent a major sorting compartment of the endomembrane system in cells. In HeLa cells, endosomes are approximately 500 nm in diameter when fully mature, endosomes provide an environment for material to be sorted before it reaches the degradative lysosome. For example, LDL is taken into the cell by binding to the LDL receptor at the cell surface, upon reaching early endosomes, the LDL dissociates from the receptor, and the receptor can be recycled to the cell surface. The LDL remains in the endosome and is delivered to lysosomes for processing, LDL dissociates because of the slightly acidified environment of the early endosome, generated by a vacuolar membrane proton pump V-ATPase. On the other hand, EGF and the EGF receptor have a pH-resistant bond that persists until it is delivered to lysosomes for their degradation, the mannose 6-phosphate receptor carries ligands from the Golgi destined for the lysosome by a similar mechanism. Endosomes comprise three different compartments, early endosomes, late endosomes, and recycling endosomes and they are distinguished by the time it takes for endocytosed material to reach them, and by markers such as rabs. Once endocytic vesicles have uncoated, they fuse with early endosomes, early endosomes then mature into late endosomes before fusing with lysosomes. Early endosomes mature in several ways to form late endosomes and they become increasingly acidic mainly through the activity of the V-ATPase. Many molecules that are recycled are removed by concentration in the regions of early endosomes. Loss of these tubules to recycling pathways means that late endosomes mostly lack tubules and they also increase in size due to the homotypic fusion of early endosomes into larger vesicles. Removal of recycling molecules such as receptors and mannose 6-phosphate receptors continues during this period. Finally, the endosomes lose RAB5A and acquire RAB7A, making them competent for fusion with lysosomes, fusion of late endosomes with lysosomes has been shown to result in the formation of a hybrid compartment, with characteristics intermediate of the two source compartments. For example, lysosomes are more dense than late endosomes, lysosomes reform by recondensation to their normal, higher density. However, before this happens, more late endosomes may fuse with the hybrid, some material recycles to the plasma membrane directly from early endosomes, but most traffics via recycling endosomes
8.
Legionella pneumophila
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Legionella pneumophila is a thin, aerobic, pleomorphic, flagellated, nonspore-forming, Gram-negative bacterium of the genus Legionella. L. pneumophila is the human pathogenic bacterium in this group and is the causative agent of Legionnaires disease. L. pneumophila is a Gram-negative, nonencapsulated, aerobic bacillus with a single and it is aerobic and unable to hydrolyse gelatin or produce urease. L. pneumophila is neither pigmented nor does it autofluoresce and it is oxidase- and catalase-positive, and produces beta-lactamase. L. pneumophila colony morphology is gray-white with a textured, cut-glass appearance, it also requires cysteine and it grows on yeast extract in opal-like colonies. While L. pneumophila is categorized as a Gram-negative organism, it stains poorly due to its unique lipopolysaccharide content in the leaflet of the outer cell membrane. The bases for the antigen specificity of this organism are located on the side chains of its cell wall. At least 35 different serovars of L. pneumophila have been described, sera have been used both for slide agglutination studies and for direct detection of bacteria in tissues using fluorescent-labelled antibody. Specific antibody in patients can be determined by the fluorescent antibody test. ELISA and microagglutination tests have also successfully applied. Legionella stains poorly with Gram stain, stains positive with silver, in the USA, about 30 infections with L. pneumophila appear per 100,000 residents per year. The infections peak in the summer, within endemic regions, about 4% to 5% of pneumonia cases are caused by L. pneumophila. In humans, L. pneumophila invades and replicates inside macrophages, the internalization of the bacteria can be enhanced by the presence of antibody and complement, but is not absolutely required. Internalization of the bacteria appears to occur through phagocytosis, however, L. pneumophila is also capable of infecting nonphagocytic cells through an unknown mechanism. A rare form of known as coiling phagocytosis has been described for L. pneumophila. Once internalized, the bacteria surround themselves in a vacuole that does not fuse with lysosomes that would otherwise degrade the bacteria. In this protected compartment, the bacteria multiply, the bacteria use a type IVB secretion system known as Dot/Icm to inject effector proteins into the host. These effectors are involved in increasing the ability to survive inside the host cell
9.
Open reading frame
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In molecular genetics, an open reading frame is the part of a reading frame that has the potential to be translated. An ORF is a stretch of codons that do not contain a stop codon. An ATG codon within the ORF may indicate where translation starts, the transcription termination site is located after the ORF, beyond the translation stop codon. If transcription were to cease before the stop codon, a protein would be made during translation. In eukaryotic genes with multiple exons, ORFs span intron/exon regions, one common use of closed reading frames is as one piece of evidence to assist in gene prediction. Long ORFs are often used, along with evidence, to initially identify candidate protein-coding regions or functional RNA-coding regions in a DNA sequence. The presence of an CRF does not necessarily mean that the region is never translated, for example, in a randomly generated DNA sequence with an equal percentage of each nucleotide, a stop-codon would be expected once every 21 codons. By itself even an open reading frame is not conclusive evidence for the presence of a gene. On the other hand, it has proven that some short ORFs that lack the classical hallmarks of protein-coding genes can produce functional peptides. 5’NTR of about 50% of mammal mRNAs are known to one or several sORFs. 64-75% of experimentally found translation initiation sites of sORFs are conservative in the genomes of human, such kind of situation is characteristic of SLAMF1 gene, for example. Since DNA is interpreted in groups of three nucleotides, a DNA strand has three reading frames. The double helix of a DNA molecule has two anti-parallel strands so, with the two strands having three reading frames each, there are six possible frame translations. ORF Finder, The ORF Finder is an analysis tool which finds all open reading frames of a selectable minimum size in a users sequence or in a sequence already in the database. This tool identifies all open reading frames using the standard or alternative genetic codes, the deduced amino acid sequence can be saved in various formats and searched against the sequence database using the BLAST server. The ORF Finder should be helpful in preparing complete and accurate sequence submissions and it is also packaged with the Sequin sequence submission software. The tool efficiently finds the ORFs for corresponding amino acid sequences and converts them into their single letter amino acid code, the pairwise global alignment between the sequences makes it convenient to detect the different mutations, including single nucleotide polymorphism. Needleman and Wunsch algorithms are used for the gene alignment, the ORF Investigator is written in the portable Perl programming language, and is therefore available to users of all common operating systems
10.
Gram-negative bacteria
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Gram-negative bacteria are a group of bacteria that do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation. They are characterized by their cell envelopes, which are composed of a peptidoglycan cell wall sandwiched between an inner cytoplasmic cell membrane and a bacterial outer membrane. Gram-negative bacteria are spread worldwide, in all environments that support life. Several classes of antibiotics target gram-negative bacteria specifically, including aminoglycosides, historically, the kingdom Monera was divided into four divisions based on Gram staining, Firmacutes, Gracillicutes, Mollicutes and Mendocutes. Since 1987, the monophyly of the bacteria has been disproven with molecular studies. However some authors, such as Cavalier-Smith still treat them as a monophyletic taxon, bacteria are traditionally divided into the two groups, gram-positive and gram-negative, based on their Gram stain retention. These groups are thought of as lineages, with gram-negative bacteria more closely related to one another than to gram-positive bacteria. While this is true, the classification system breaks down in some cases. A given bacterias Gram stain result, bacterial membrane organization, as such, the Gram stain cannot be reliably used to assess familial relationships of bacteria. That said, Gram staining does often give information about the composition of the cell membrane. Of these two distinct groups of prokaryotic organisms, monoderm prokaryotes are indicated to be ancestral. In addition, a number of taxa that are either part of the phylum Firmicutes or branches in its proximity are also found to possess a diderm cell structure. Other notable groups of bacteria include the cyanobacteria, spirochaetes, green sulfur. Medically relevant gram-negative cocci include the four types that cause a sexually transmitted disease, a meningitis, medically relevant gram-negative bacilli include a multitude of species. Some of them cause primarily respiratory problems, primarily urinary problems, transformation is one of three processes for horizontal gene transfer, in which exogenous genetic material passes from bacterium to another, the other two being conjugation and transduction. In transformation, the material passes through the intervening medium. One of the unique characteristics of gram-negative bacteria is the structure of the bacterial outer membrane. The outer leaflet of this comprises a complex lipopolysaccharide whose lipid portion acts as an endotoxin
, PMID 19246385
