University of Tübingen
The University of Tübingen the Eberhard Karls University of Tübingen, is a public research university located in the city of Tübingen, Baden-Württemberg, Germany. It is a German Excellence University, Tübingen is ranked as one of the best universities in Germany and is known as a centre for the study of medicine and theology and religion; the university's noted alumni include numerous presidents, ministers, EU Commissioners and judges of the Federal Constitutional Court. The university is associated with eleven Nobel laureates in the fields of medicine and chemistry; the University of Tübingen was founded in 1477 by Count Eberhard V the first Duke of Württemberg, a civic and ecclesiastic reformer who established the school after becoming absorbed in the Renaissance revival of learning during his travels to Italy. Its first rector was Johannes Nauclerus, its present name was conferred on it in 1769 by Duke Karl Eugen who appended his first name to that of the founder. The university became the principal university of the kingdom of Württemberg.
Today, it is one of nine state universities funded by the German federal state of Baden-Württemberg. The University of Tübingen has a history of innovative thought in theology, in which the university and the Tübinger Stift are famous to this day. Philipp Melanchthon, the prime mover in building the German school system and a chief figure in the Protestant Reformation, helped establish its direction. Among Tübingen's eminent students have been the astronomer Johannes Kepler. "The Tübingen Three" refers to Hölderlin and Schelling, who were roommates at the Tübinger Stift. Theologian Helmut Thielicke revived postwar Tübingen when he took over a professorship at the reopened theological faculty in 1947, being made administrative head of the university and President of the Chancellor's Conference in 1951; the university rose to the height of its prominence in the middle of the 19th century with the teachings of poet and civic leader Ludwig Uhland and the Protestant theologian Ferdinand Christian Baur, whose circle and students became known as the "Tübingen School", which pioneered the historical-critical analysis of biblical and early Christian texts, an approach referred to as "higher criticism."
The University of Tübingen was the first German university to establish a faculty of natural sciences, in 1863. DNA was discovered in 1868 at the University of Tübingen by Friedrich Miescher. Christiane Nüsslein-Volhard, the first female Nobel Prize winner in medicine in Germany works at Tübingen; the faculty for economics and business was founded in 1817 as the "Staatswissenschaftliche Fakultät" and was the first of its kind in Germany. The University played a leading role in efforts to legitimize the policies of the Third Reich as "scientific". Before the victory of the Nazi Party in the general election in March 1933, there were hardly any Jewish faculty and a few Jewish students. Physicist Hans Bethe was dismissed on 20 April 1933 because of "non-Aryan" origin. Religion professor Traugott Konstantin Oesterreich and the mathematician Erich Kamke were forced to take early retirement in both cases the "non-Aryan" origin of their wives. At least 1158 people were sterilized at the University Hospital.
In 1966, Joseph Ratzinger, who would become Pope Benedict XVI, was appointed to a chair in dogmatic theology in the Faculty of Catholic Theology at Tübingen, where he was a colleague of Hans Küng. In 1967, Jürgen Moltmann, one of the most influential Protestant theologians of the 20th century, was appointed Professor of Systematic Theology in the Faculty of Protestant Theology. Drafted in 1944 by Nazi Germany, he was an Allied prisoner of war 1945-1948, he was influenced by friend Ernst Bloch, the Marxist philosopher. In 1970, the university was restructured into a series of faculties as independent departments of study and research after the manner of French universities; the university made the headlines in November 2009 when a group of left-leaning students occupied one of the main lecture halls, the Kupferbau, for several days. The students' goal was to protest tuition fees and maintain that education should be free for everyone. In May 2010, Tübingen joined the Matariki Network of Universities together with Dartmouth College, Durham University, Queen’s University, University of Otago, University of Western Australia and Uppsala University.
The University of Tübingen undertakes a broad range of research projects in various fields. Among the more prominent ones in the natural sciences are the Hertie Institute for Clinical Brain Research, which focuses on general and cellular neurology as well as neurodegeneration, the Centre for Interdisciplinary Clinical Research, which deals with cell biology in diagnostics and therapy of organ system diseases. In the liberal arts, the University of Tübingen is noteworthy for having the only faculty of rhetoric in Germany – the department was founded by Walter Jens, an important intellectual and literary critic; the university boasts continued pre-eminence in its centuries-old traditions of research in the fields of philosophy and philology. Since at least the nineteenth century, Tübingen has been the home of world-class research in prehistoric studies and the study of antiquity, including the study of the ancient Near East.
A geneticist is a biologist who studies genetics, the science of genes and variation of organisms. A geneticist can be employed as a lecturer. Geneticists perform general research on genetic processes as well as development of genetic technologies to aid in the medicine and agriculture industries; some geneticists perform experiments in model organisms such as Drosophila, C. elegans, rodents or Humans and analyze data to interpret the inheritance of biological traits. A geneticist can be a scientist who has earned a Ph. D in Genetics or a physician, trained in genetics as a specialization, they evaluate and manage patients with hereditary conditions or congenital malformations, genetic risk calculations, mutation analysis as well as refer patients to other medical specialties. The geneticist carries out studies and counsels patients with genetic disorders. Geneticists participate in courses from many areas, such as biology, physics, cell biology and mathematics, they participate in more specific genetics courses such as molecular genetics, transmission genetics, population genetics, quantitative genetics, ecological genetics, genomics.
Geneticists can work in many different fields, doing a variety of jobs. There are many careers for geneticists in medicine, wildlife, general sciences, or many other fields. Listed below are a few examples of careers a geneticist may pursue
Mirabilis jalapa, the marvel of Peru or four o'clock flower, is the most grown ornamental species of Mirabilis plant, is available in a range of colours. Mirabilis in Latin means wonderful and Jalapa is the state capital of Veracruz in México. Mirabilis jalapa was cultivated by the Aztecs for ornamental purposes; the flowers open from late afternoon or at dusk, giving rise to one of its common names. Flowers produce a strong, sweet-smelling fragrance throughout the night close for good in the morning. New flowers open the following day, it arrived in Europe in 1525. Today, it is common in many tropical regions and is valued in Europe as a ornamental plant; the name of Mirabilis jalapa given by Carl Von Linne in 1753 is formed from the scientific Latin Mirabilis meaning "admirable" by allusion to the remarkable colors of its flowers and the specific name jalapa that would refer to its origin in the Jalapa in Guatemala. But the epithet of jalapa could refer to the city of Xalapa in Mexico from which came a former purgative drug, named jalap, taken from the tubers of the tuberous jalap.
Linnaeus refers to all species of Jalapa described by Joseph Pitton de Tournefort who in 1694 wrote: "The Jalap, or Belle de Nuit is a kind of plant whose flower is a funnel-shaped flared pipe with a crenellated pavilion... Father Plumier assured me that the Jalap, brought to us with the root of America, was a true species of Belle de nuit. We have received the seed, which has produced in the Jardin Royal de Paris a plant quite like the common Belle de nuit, it is a perennial, bushy plant that reaches stature heights of 1 up to 2 meters in height. It may be grown as an annual in the temperate zone; the single-seeded fruits are spherical and black upon maturity, having started out greenish-yellow. The stems are thick, quadrangular with many ramifications and rooting at the nodes; the posture is prostrate. A curious aspect of M. jalapa is that flowers with different colors grow on the same plant. Additionally, an individual flower can be splashed with different colors. Flower patterns are referred to as sectors and spots.
A single flower can be plain yellow, magenta, pink, or white, or have a combination of sectors and spots. Furthermore, different combinations of flowers and patterns can occur on different flowers of the same plant; the flowers are yellow and white, but a different combination of flowers growing on the same single four o’clock plant can be found. Another interesting point is a color-changing phenomenon. For example, in the yellow variety, as the plant matures, it can display flowers that change to a dark pink colour. White flowers can change to light violet. Despite their appearance, the flowers are not formed from petals – rather they are a pigmented modification of the calyx. The'calyx' is an involucre of bracts; the flowers are funnel-shaped and pentalobed, they are made of a corolla. The inflorescences contain three to seven unpopped flowers. Earning the name "four-clock flower", the fragrant flowers open in the late afternoon or early evening, in overcast weather, exhale a scent reminiscent of the tobacco flower, attract moths for pollination.
The anthesis thus remains visible part of the day. The flowers are pollinated by long-tongued moths of the family Sphingidae, such as the sphinx moths or hawk moths and other nocturnal pollinators attracted by the fragrance; the plant does best in full sun. In the sun the leaves wither return vigorously in the evening, when temperatures start to fall and the sun sets, it can not stand the cold, the aerial part with the first frosts deteriorates and can die, but the underground part that can return to vegetate in spring remains vital. The plant will self-seed spreading if left unchecked in a garden; some gardeners recommend that the seeds should be soaked before planting, but this is not necessary. In North America, the plant perennializes in warm, coastal environments in USDA zones 7–10; the fragrance of the flower is more noticeable during the warm period of the day. The plant is easy to grow, as long as it is sunny or shaded. Under these conditions, it grows quickly, it grows preferably in light soil, rich in humus and well draining, it is neutral side acidity.
Pot cultivation is always possible with a mixture of 80% soil and 20% garden soil and a deep container with the tubers being put at a depth of 10 cm. It is sown from mid-February to May; the seeds germinate at a temperature of 18 °C. Mirabilis jalapa hails from tropical South America, but has become naturalized throughout tropical and temperate regions. In cooler subtropical and temperate regions, it will die back with the first frosts or as the weather cools, regrowing in the following spring from the tuberous roots. Mirabilis jalapa is native to the dry tropical regions of Central and South America: Guatemala, Mexico and Peru, it is naturalized in many countries in Asia, United States, Middle East and Europe. In Réunion, Mirabilis jalapa was an ornamental species, it occurs in a ruderal debris area, is common in weedy sugarcane fields on the west and south coasts. Its high seed production and rapid
The ribosome is a complex molecular machine, found within all living cells, that serves as the site of biological protein synthesis. Ribosomes link amino acids together in the order specified by messenger RNA molecules. Ribosomes consist of two major components: the small ribosomal subunits, which read the RNA, the large subunits, which join amino acids to form a polypeptide chain; each subunit consists of a variety of ribosomal proteins. The ribosomes and associated molecules are known as the translational apparatus; the sequence of DNA, which encodes the sequence of the amino acids in a protein, is copied into a messenger RNA chain. It may be copied many times into RNA chains. Ribosomes can bind to a messenger RNA chain and use its sequence for determining the correct sequence of amino acids for generating a given protein. Amino acids are selected and carried to the ribosome by transfer RNA molecules, which enter one part of the ribosome and bind to the messenger RNA chain, it is during this binding that the correct translation of nucleic acid sequence to amino acid sequence occurs.
For each coding triplet in the messenger RNA there is a distinct transfer RNA that matches and which carries the correct amino acid for that coding triplet. The attached amino acids are linked together by another part of the ribosome. Once the protein is produced, it can fold to produce a specific functional three-dimensional structure although during synthesis some proteins start folding into their correct form. A ribosome is therefore a ribonucleoprotein; each ribosome is divided into two subunits: a smaller subunit which binds to a larger subunit and the mRNA pattern, a larger subunit which binds to the tRNA, the amino acids, the smaller subunit. When a ribosome finishes reading an mRNA molecule, these two subunits split apart. Ribosomes are ribozymes, because the catalytic peptidyl transferase activity that links amino acids together is performed by the ribosomal RNA. Ribosomes are associated with the intracellular membranes that make up the rough endoplasmic reticulum. Ribosomes from bacteria and eukaryotes in the three-domain system, resemble each other to a remarkable degree, evidence of a common origin.
They differ in their size, sequence and the ratio of protein to RNA. The differences in structure allow some antibiotics to kill bacteria by inhibiting their ribosomes, while leaving human ribosomes unaffected. In bacteria and archaea, more than one ribosome may move along a single mRNA chain at one time, each "reading" its sequence and producing a corresponding protein molecule; the mitochondrial ribosomes of eukaryotic cells, are produced from mitochondrial genes, functionally resemble many features of those in bacteria, reflecting the evolutionary origin of mitochondria. Ribosomes were first observed in the mid-1950s by Romanian-American cell biologist George Emil Palade, using an electron microscope, as dense particles or granules; the term "ribosome" was proposed by scientist Richard B. Roberts in the end of 1950s: During the course of the symposium a semantic difficulty became apparent. To some of the participants, "microsomes" mean the ribonucleoprotein particles of the microsome fraction contaminated by other protein and lipid material.
The phrase "microsomal particles" does not seem adequate, "ribonucleoprotein particles of the microsome fraction" is much too awkward. During the meeting, the word "ribosome" was suggested, which has a satisfactory name and a pleasant sound; the present confusion would be eliminated if "ribosome" were adopted to designate ribonucleoprotein particles in sizes ranging from 35 to 100S. Albert Claude, Christian de Duve, George Emil Palade were jointly awarded the Nobel Prize in Physiology or Medicine, in 1974, for the discovery of the ribosome; the Nobel Prize in Chemistry 2009 was awarded to Venkatraman Ramakrishnan, Thomas A. Steitz and Ada E. Yonath for determining the detailed structure and mechanism of the ribosome; the ribosome is a complex cellular machine. It is made up of specialized RNA known as ribosomal RNA as well as dozens of distinct proteins; the ribosomal proteins and rRNAs are arranged into two distinct ribosomal pieces of different size, known as the large and small subunit of the ribosome.
Ribosomes consist of two subunits that fit together and work as one to translate the mRNA into a polypeptide chain during protein synthesis. Because they are formed from two subunits of non-equal size, they are longer in the axis than in diameter. Prokaryotic ribosomes are around 20 nm in diameter and are composed of 65% rRNA and 35% ribosomal proteins. Eukaryotic ribosomes are between 25 and 30 nm in diameter with an rRNA-to-protein ratio, close to 1. Crystallographic work has shown that there are no ribosomal proteins close to the reaction site for polypeptide synthesis; this suggests that the protein components of ribosomes do not directly participate in peptide bond formation catalysis, but rather that these proteins act as a scaffold that may enhance the ability of rRNA to synthesize protein. The ribosomal subunits of prokaryotes and eukaryotes are quite similar; the unit of measurement used to describe the ribosomal subunits and the rRNA fragments is the Svedberg unit, a measure of the rate of sedimentation in centrifugation rather than size.
This accounts for why fragment names do not add up: for example, prokaryotic 70S ribosomes are made of 50S and 30S subunits. Prokaryotes have 70
Royal Library of the Netherlands
The Royal Library of the Netherlands is based in The Hague and was founded in 1798. The mission of the Royal Library of the Netherlands, as presented on the library's web site, is to provide "access to the knowledge and culture of the past and the present by providing high-quality services for research and cultural experience"; the initiative to found a national library was proposed by representative Albert Jan Verbeek on August 17 1798. The collection would be based on the confiscated book collection of William V; the library was founded as the Nationale Bibliotheek on November 8 of the same year, after a committee of representatives had advised the creation of a national library on the same day. The National Library was only open to members of the Representative Body. King Louis Bonaparte gave the national library its name of the Royal Library in 1806. Napoleon Bonaparte transferred the Royal Library to The Hague as property, while allowing the Imperial Library in Paris to expropriate publications from the Royal Library.
In 1815 King William I of the Netherlands confirmed the name of'Royal Library' by royal resolution. It has been known as the National Library of the Netherlands since 1982, when it opened new quarters; the institution became independent of the state in 1996, although it is financed by the Department of Education and Science. In 2004, the National Library of the Netherlands contained 3,300,000 items, equivalent to 67 kilometers of bookshelves. Most items in the collection are books. There are pieces of "grey literature", where the author, publisher, or date may not be apparent but the document has cultural or intellectual significance; the collection contains the entire literature of the Netherlands, from medieval manuscripts to modern scientific publications. For a publication to be accepted, it must be from a registered Dutch publisher; the collection is accessible for members. Any person aged 16 years or older can become a member. One day passes are available. Requests for material take 30 minutes.
The KB hosts several open access websites, including the "Memory of the Netherlands". List of libraries in the Netherlands European Library Nederlandse Centrale Catalogus Books in the Netherlands Media related to Koninklijke Bibliotheek at Wikimedia Commons Official website
Chloroplasts are organelles that conduct photosynthesis, where the photosynthetic pigment chlorophyll captures the energy from sunlight, converts it, stores it in the energy-storage molecules ATP and NADPH while freeing oxygen from water in plant and algal cells. They use the ATP and NADPH to make organic molecules from carbon dioxide in a process known as the Calvin cycle. Chloroplasts carry out a number of other functions, including fatty acid synthesis, much amino acid synthesis, the immune response in plants; the number of chloroplasts per cell varies from one, in unicellular algae, up to 100 in plants like Arabidopsis and wheat. A chloroplast is a type of organelle known as a plastid, characterized by its two membranes and a high concentration of chlorophyll. Other plastid types, such as the leucoplast and the chromoplast, contain little chlorophyll and do not carry out photosynthesis. Chloroplasts are dynamic—they circulate and are moved around within plant cells, pinch in two to reproduce.
Their behavior is influenced by environmental factors like light color and intensity. Chloroplasts, like mitochondria, contain their own DNA, thought to be inherited from their ancestor—a photosynthetic cyanobacterium, engulfed by an early eukaryotic cell. Chloroplasts cannot be made by the plant cell and must be inherited by each daughter cell during cell division. With one exception, all chloroplasts can be traced back to a single endosymbiotic event, when a cyanobacterium was engulfed by the eukaryote. Despite this, chloroplasts can be found in an wide set of organisms, some not directly related to each other—a consequence of many secondary and tertiary endosymbiotic events; the word chloroplast is derived from the Greek words chloros, which means green, plastes, which means "the one who forms". The first definitive description of a chloroplast was given by Hugo von Mohl in 1837 as discrete bodies within the green plant cell. In 1883, A. F. W. Schimper would name these bodies as "chloroplastids".
In 1884, Eduard Strasburger adopted the term "chloroplasts". Chloroplasts are one of many types of organelles in the plant cell, they are considered to have originated from cyanobacteria through endosymbiosis—when a eukaryotic cell engulfed a photosynthesizing cyanobacterium that became a permanent resident in the cell. Mitochondria are thought to have come from a similar event, where an aerobic prokaryote was engulfed; this origin of chloroplasts was first suggested by the Russian biologist Konstantin Mereschkowski in 1905 after Andreas Schimper observed in 1883 that chloroplasts resemble cyanobacteria. Chloroplasts are only found in plants and the amoeboid Paulinella chromatophora. Cyanobacteria are considered the ancestors of chloroplasts, they are sometimes called blue-green algae though they are prokaryotes. They are a diverse phylum of bacteria capable of carrying out photosynthesis, are gram-negative, meaning that they have two cell membranes. Cyanobacteria contain a peptidoglycan cell wall, thicker than in other gram-negative bacteria, and, located between their two cell membranes.
Like chloroplasts, they have thylakoids within. On the thylakoid membranes are photosynthetic pigments, including chlorophyll a. Phycobilins are common cyanobacterial pigments organized into hemispherical phycobilisomes attached to the outside of the thylakoid membranes. Somewhere around 1 to 2 billion years ago, a free-living cyanobacterium entered an early eukaryotic cell, either as food or as an internal parasite, but managed to escape the phagocytic vacuole it was contained in; the two innermost lipid-bilayer membranes that surround all chloroplasts correspond to the outer and inner membranes of the ancestral cyanobacterium's gram negative cell wall, not the phagosomal membrane from the host, lost. The new cellular resident became an advantage, providing food for the eukaryotic host, which allowed it to live within it. Over time, the cyanobacterium was assimilated, many of its genes were lost or transferred to the nucleus of the host. From genomes that originally contained over 3000 genes only about 130 genes remain in the chloroplasts of contemporary plants.
Some of its proteins were synthesized in the cytoplasm of the host cell, imported back into the chloroplast. Separately, somewhere around 500 million years ago, it happened again and led to the amoeboid Paulinella chromatophora; this event is called endosymbiosis, or "cell living inside another cell with a mutual benefit for both". The external cell is referred to as the host while the internal cell is called the endosymbiont. Chloroplasts are believed to have arisen after mitochondria, since all eukaryotes contain mitochondria, but not all have chloroplasts; this is called serial endosymbiosis—an early eukaryote engulfing the mitochondrion ancestor, some descendants of it engulfing the chloroplast ancestor, creating a cell with both chloroplasts and mitochondria. Whether or not primary chloroplasts came from a single endosymbiotic event, or many independent engulfments across various eukaryotic lineages, has long been debated, it is now held that organisms with primary chloroplasts share a single ancestor that took in a cyanobacterium 600–2000 million years ago.
It has been proposed. The exception is the amoeboid Paulinella chromatophora, which descends from an ancestor that took in a Prochlorococcus cyanobacterium 90–500 million years ago; these chloroplasts
Carl Wilhelm von Nägeli was a Swiss botanist. He studied cell division and pollination but became known as the man who discouraged Gregor Mendel from further work on genetics, he rejected natural selection as a mechanism of evolution, favouring orthogenesis driven by a supposed "inner perfecting principle". Nägeli was born in Kilchberg near Zurich. From 1839, he studied botany under A. P. de Candolle at Geneva, graduated with a botanical thesis at Zurich in 1840. His attention having been directed by Matthias Jakob Schleiden professor of botany at Jena, to the microscopical study of plants, he engaged more in that branch of research, he coined term meristematic tissue in 1858. Soon after graduation he became Privatdozent and subsequently professor extraordinary, in the University of Zurich, it was thought that Nägeli had first observed cell division during the formation of pollen, in 1842. However, this is disputed by Henry Harris, who writes: "What Nägeli saw and did not see in plant material at about the same time is somewhat obscure...
I conclude... that, unlike Remak, he did not observe nuclear division... it is clear that Nägeli did not in 1844 have any idea of the importance of the nucleus in the life of the cell."In the 1857 that microsporidia where first described by the Nageli. This was due to them being the agent in causing pebrine disease of silkworms which devastated the silk industry in Europe. Among his other contributions to science were a series of papers in the Zeitschrift für wissenschaftliche Botanik; however Nägeli is best known nowadays for his unproductive correspondence with Gregor Mendel concerning the latter's celebrated work on Pisum sativum, the garden pea. The writer Simon Mawer, in his book Gregor Mendel: planting the seeds of genetics, gives us an interesting and detailed account of Nägeli's correspondence with Mendel. Mawer underlines that, at the time Nägeli was writing to the friar from Moravia, Nägeli "must have been preparing his great work entitled A mechanico-physiological theory of organic evolution in which he proposes the concept of the'idioplasm' as the hypothetical transmitter of inherited characters".
Mawer notes. That prompted him to write: "We can forgive von Nägeli for being obtuse and supercilious. We can forgive him for being ignorant, a scientist of his time who did not have the equipment to understand the significance of what Mendel had done despite the fact that he speculated extensively about inheritance, but omitting an account of Mendel's work from his book is unforgivable." Nägeli and Hugo von Mohl were the first scientists to distinguish the plant cell wall from the inner contents, named the protoplasm in 1846. Nägeli believed that cells receive their hereditary characters from a part of the protoplasm which he called the idioplasma. Nägeli was an opponent of Darwinism, he developed. He wrote that many evolutionary developments were nonadaptive and variation was internally programmed. Nägeli coined the terms'Meristem','Xylem' and'Phloem' while he and Hofmeister gave the'Apical Cell Theory' which aimed to explain origin and functioning of the shoot apex meristem in plants. University of Freiburg Faculty of Biology This article incorporates text from a publication now in the public domain: Chisholm, Hugh, ed..
"Naegeli, Karl Wilhelm von". Encyclopædia Britannica. Cambridge University Press. Short biography and bibliography in the Virtual Laboratory of the Max Planck Institute for the History of Science Biography and work Entire facsimile text of "Mechanisch-physiologische Theorie der Abstammungslehre" Works by Carl Nägeli at Project Gutenberg Works by or about Carl Nägeli at Internet Archive "Nägeli, Karl Wilhelm". Encyclopedia Americana. 1920