Nathanael Pringsheim was a German botanist. Nathanael Pringsheim was born at Landsberg, Prussian Silesia, studied at the universities of Breslau and Berlin successively, he graduated in 1848 as doctor of philosophy with the thesis De forma et incremento stratorum crassiorum in plantarum cellula, became a leader in the great botanical renaissance of the 19th century. His contributions to scientific phycology were of striking interest. Pringsheim was among the first to demonstrate the occurrence of a sexual process in this class of plants, he drew from his observations weighty conclusions as to the nature of sexuality. Together with the French investigators Gustave Adolphe Thuret and Jean-Baptiste Édouard Bornet, Pringsheim ranks as the founder of our scientific knowledge of the algae. Among his researches in this field may be mentioned those on Vaucheria, the Oedogoniaceae, the Coleochaeteae and Pandorina; this was a discovery of fundamental importance. A work on the course of morphological differentiation in the Sphacelariaceae, a family of marine algae, is of great interest, inasmuch as it treats of evolutionary questions.
Connected with Pringsheim's algological work was his long-continued investigation of the Saprolegniaceae, a family of algoid fungi, some of which have become notorious as the causes of disease in fish. Among his contributions to our knowledge of the higher plants, his exhaustive monograph on the curious genus of water-ferns, deserves special mention, his career as a morphologist culminated in 1876 with the publication of a memoir on the alternation of generations in thallophytes and mosses. From 1874 to the close of his life Pringsheim's activity was chiefly directed to physiological questions: he published, in a long series of memoirs, a theory of the carbon-assimilation of green plants, the central point of, the conception of the chlorophyll-pigment as a screen, with the main function of protecting the protoplasm from light-rays which would neutralize its assimilative activity by stimulating too active respiration; this view has not been accepted as offering an adequate explanation of the phenomena.
Pringsheim founded in 1858, edited till his death, the classical Jahrbücher für wissenschaftliche Botanik, which still bears his name. He was founder, in 1882, first president, of the German Botanical Society, his work was for the most part carried on in his private laboratory in Berlin. In early life he was a keen politician on the Liberal side, he died in Berlin. A fuller account of Pringsheim's career will be found in Nature, vol. Ii. and in the Berichte der deutschen botanischen Gesellschaft, vol. xiii. The latter is by Ferdinand Cohn; the standard botanical author abbreviation Pringsh. is applied to species he described. Pringsheim Attribution This article incorporates text from a publication now in the public domain: Scott, Dukinfield Henry. "Pringsheim, Nathanael". In Chisholm, Hugh. Encyclopædia Britannica. 22. Cambridge University Press. P. 350. A fuller account of Pringsheim's career will be found in: Nature, vol. Ii. Ferdinand Cohn Berichte der deutschen botanischen Gesellschaft, vol. xiii. Jewish Encyclopedia
Poland the Republic of Poland, is a country located in Central Europe. It is divided into 16 administrative subdivisions, covering an area of 312,696 square kilometres, has a temperate seasonal climate. With a population of 38.5 million people, Poland is the sixth most populous member state of the European Union. Poland's capital and largest metropolis is Warsaw. Other major cities include Kraków, Łódź, Wrocław, Poznań, Gdańsk, Szczecin. Poland is bordered by the Baltic Sea, Russia's Kaliningrad Oblast and Lithuania to the north and Ukraine to the east and Czech Republic, to the south, Germany to the west; the establishment of the Polish state can be traced back to AD 966, when Mieszko I, ruler of the realm coextensive with the territory of present-day Poland, converted to Christianity. The Kingdom of Poland was founded in 1025, in 1569 it cemented its longstanding political association with the Grand Duchy of Lithuania by signing the Union of Lublin; this union formed the Polish–Lithuanian Commonwealth, one of the largest and most populous countries of 16th and 17th century Europe, with a uniquely liberal political system which adopted Europe's first written national constitution, the Constitution of 3 May 1791.
More than a century after the Partitions of Poland at the end of the 18th century, Poland regained its independence in 1918 with the Treaty of Versailles. In September 1939, World War II started with the invasion of Poland by Germany, followed by the Soviet Union invading Poland in accordance with the Molotov–Ribbentrop Pact. More than six million Polish citizens, including 90% of the country's Jews, perished in the war. In 1947, the Polish People's Republic was established as a satellite state under Soviet influence. In the aftermath of the Revolutions of 1989, most notably through the emergence of the Solidarity movement, Poland reestablished itself as a presidential democratic republic. Poland is regional power, it has the fifth largest economy by GDP in the European Union and one of the most dynamic economies in the world achieving a high rank on the Human Development Index. Additionally, the Polish Stock Exchange in Warsaw is the largest and most important in Central Europe. Poland is a developed country, which maintains a high-income economy along with high standards of living, life quality, safety and economic freedom.
Having a developed school educational system, the country provides free university education, state-funded social security, a universal health care system for all citizens. Poland has 15 UNESCO World Heritage Sites. Poland is a member state of the European Union, the Schengen Area, the United Nations, NATO, the OECD, the Three Seas Initiative, the Visegrád Group; the origin of the name "Poland" derives from the West Slavic tribe of Polans that inhabited the Warta river basin of the historic Greater Poland region starting in the 6th century. The origin of the name "Polanie" itself derives from the early Slavic word "pole". In some languages, such as Hungarian, Lithuanian and Turkish, the exonym for Poland is Lechites, which derives from the name of a semi-legendary ruler of Polans, Lech I. Early Bronze Age in Poland begun around 2400 BC, while the Iron Age commenced in 750 BC. During this time, the Lusatian culture, spanning both the Bronze and Iron Ages, became prominent; the most famous archaeological find from the prehistory and protohistory of Poland is the Biskupin fortified settlement, dating from the Lusatian culture of the early Iron Age, around 700 BC.
Throughout the Antiquity period, many distinct ancient ethnic groups populated the regions of what is now Poland in an era that dates from about 400 BC to 500 AD. These groups are identified as Celtic, Slavic and Germanic tribes. Recent archeological findings in the Kujawy region, confirmed the presence of the Roman Legions on the territory of Poland; these were most expeditionary missions sent out to protect the amber trade. The exact time and routes of the original migration and settlement of Slavic peoples lacks written records and can only be defined as fragmented; the Slavic tribes who would form Poland migrated to these areas in the second half of the 5th century AD. Up until the creation of Mieszko's state and his subsequent conversion to Christianity in 966 AD, the main religion of Slavic tribes that inhabited the geographical area of present-day Poland was Slavic paganism. With the Baptism of Poland the Polish rulers accepted Christianity and the religious authority of the Roman Church.
However, the transition from paganism was not a smooth and instantaneous process for the rest of the population as evident from the pagan reaction of the 1030s. Poland began to form into a recognizable unitary and territorial entity around the middle of the 10th century under the Piast dynasty. Poland's first documented ruler, Mieszko I, accepted Christianity with the Baptism of Poland in 966, as the new official religion of his subjects; the bulk of the population converted in the course of the next few centuries. In 1000, Boleslaw the Brave, continuing the policy of his father Mieszko, held a Congress of Gniezno and created the metropolis of Gniezno and the dioceses of Kraków, Kołobrzeg, Wrocław. However, the pagan unrest led to the transfer of the capital to Kraków in 1038 by Casimir I the Restorer. In 1109, Prince Bolesław III Wrymouth defeated the King of Germany Henry V at the Battle of Hundsfeld, stopping the Ge
Cell biology is a branch of biology that studies the structure and function of the cell, the basic unit of life. Cell biology is concerned with the physiological properties, metabolic processes, signaling pathways, life cycle, chemical composition and interactions of the cell with their environment; this is done both on a microscopic and molecular level as it encompasses prokaryotic cells and eukaryotic cells. Knowing the components of cells and how cells work is fundamental to all biological sciences. Research in cell biology is related to genetics, molecular biology and cytochemistry. Cells, which were once invisible to the naked eye, were first seen in 17th century Europe with the invention of the compound microscope. Robert Hooke was the first person to term the building block of all living organisms as "cells" after looking at cork; the cell theory states. The theory states that both plants and animals are composed of cells, confirmed by plant scientist, Matthias Schleiden and animal scientist, Theodor Schwann in 1839.
19 years Rudolf Virchow contributed to the cell theory, arguing that all cells come from the division of preexisting cells. In recent years, there have been many studies. Scientists have struggled to decide. Viruses lack common characteristics of a living cell, such as membranes, cell organelles, the ability to reproduce by themselves. Viruses range from 0.005 to 0.03 micrometers in size. Modern day cell biology research looks at different ways to culture and manipulate cells outside of a living body to further research in human anatomy and physiology, to derive treatments and other medications, etc; the techniques by which cells are studied have evolved. Advancement in microscopic techniques and technology such as fluorescence microscopy, phase-contrast microscopy, dark field microscopy, confocal microscopy, transmission electron microscopy, etc. have allowed scientists to get a better idea of the structure of cells. There are two fundamental classifications of cells: eukaryotes; the major difference between the two is the absence of organelles.
Other factors such as size, the way in which they reproduce, the number of cells distinguish them from one another. Eukaryotic cells include animal, plant and protozoa cells which all have a nucleus enclosed by a membrane, with various shapes and sizes. Prokaryotic cells, lacking an enclosed nucleus, include bacteria and archaea. Prokaryotic cells are much smaller than eukaryotic cells, making prokaryotic cells the smallest form of life. Cytologists focus on eukaryotic cells whereas prokaryotic cells are the focus of microbiologists, but this is not always the case; the study of the cell is done on a molecular level. 75-85% of the cell's volume is due to water making it an indispensable solvent as a result of its polarity and structure. These molecules within the cell, which operate as substrates, provide a suitable environment for the cell to carry out metabolic reactions and signalling; the cell shape varies among the different types of organisms, are thus classified into two categories: eukaryotes and prokaryotes.
In the case of eukaryotic cells - which are made up of animal, plant and protozoa cells - the shapes are round and spherical or oval while for prokaryotic cells – which are composed of bacteria and archaea - the shapes are: spherical, rods and spirals. Cell biology focuses more on the study of eukaryotic cells, their signalling pathways, rather than on prokaryotes, covered under microbiology; the main constituents of the general molecular composition of the cell includes: proteins and lipids which are either free flowing or membrane bound, along with different internal compartments known as organelles. This environment of the cell is made up of hydrophilic and hydrophobic regions which allows for the exchange of the above-mentioned molecules and ions; the hydrophilic regions of the cell are on the inside and outside of the cell, while the hydrophobic regions are within the phospholipid bilayer of the cell membrane. The cell membrane consists of lipids and proteins which accounts for its hydrophobicity as a result of being non-polar substances.
Therefore, in order for these molecules to participate in reactions, within the cell, they need to be able to cross this membrane layer to get into the cell. They accomplish this process of gaining access to the cell via: osmotic pressure, concentration gradients, membrane channels. Inside of the cell are extensive internal sub-cellular membrane-bounded compartments called organelles. Cells contain specialized sub-cellular compartments including cell membrane, cytoplasm,mitochondria, ribosomes. See organelle; the growth process of the cell does not refer to the size of the cell, but instead the density of the number of cells present in the organism at a given time. Cell growth pertains to the increase in the number of cells present in an organism as it grows and develops. Cells are the foundation of all organisms, they are the fundamental unit of life; the growth and development of the cell are essential for the maintenance of the host, survival of the organisms. For this process the cell goes through the steps of
National Diet Library
The National Diet Library is the national library of Japan and among the largest libraries in the world. It was established in 1948 for the purpose of assisting members of the National Diet of Japan in researching matters of public policy; the library is similar in scope to the United States Library of Congress. The National Diet Library consists of two main facilities in Tōkyō and Kyōtō, several other branch libraries throughout Japan; the National Diet Library is the successor of three separate libraries: the library of the House of Peers, the library of the House of Representatives, both of which were established at the creation of Japan's Imperial Diet in 1890. The Diet's power in prewar Japan was limited, its need for information was "correspondingly small"; the original Diet libraries "never developed either the collections or the services which might have made them vital adjuncts of genuinely responsible legislative activity". Until Japan's defeat, the executive had controlled all political documents, depriving the people and the Diet of access to vital information.
The U. S. occupation forces under General Douglas MacArthur deemed reform of the Diet library system to be an important part of the democratization of Japan after its defeat in World War II. In 1946, each house of the Diet formed its own National Diet Library Standing Committee. Hani Gorō, a Marxist historian, imprisoned during the war for thought crimes and had been elected to the House of Councillors after the war, spearheaded the reform efforts. Hani envisioned the new body as "both a'citadel of popular sovereignty'", the means of realizing a "peaceful revolution"; the Occupation officers responsible for overseeing library reforms reported that, although the Occupation was a catalyst for change, local initiative pre-existed the Occupation, the successful reforms were due to dedicated Japanese like Hani. The National Diet Library opened in June 1948 in the present-day State Guest-House with an initial collection of 100,000 volumes; the first Librarian of the Diet Library was the politician Tokujirō Kanamori.
The philosopher Masakazu Nakai served as the first Vice Librarian. In 1949, the NDL became the only national library in Japan. At this time the collection gained an additional million volumes housed in the former National Library in Ueno. In 1961, the NDL opened at its present location in Nagatachō, adjacent to the National Diet. In 1986, the NDL's Annex was completed to accommodate a combined total of 12 million books and periodicals; the Kansai-kan, which opened in October 2002 in the Kansai Science City, has a collection of 6 million items. In May 2002, the NDL opened a new branch, the International Library of Children's Literature, in the former building of the Imperial Library in Ueno; this branch contains some 400,000 items of children's literature from around the world. Though the NDL's original mandate was to be a research library for the National Diet, the general public is the largest consumer of the library's services. In the fiscal year ending March 2004, for example, the library reported more than 250,000 reference inquiries.
As Japan's national library, the NDL collects copies of all publications published in Japan. Moreover, because the NDL serves as a research library for Diet members, their staffs, the general public, it maintains an extensive collection of materials published in foreign languages on a wide range of topics; the NDL has eight major specialized collections: Modern Political and Constitutional History. The Modern Political and Constitutional History Collection comprises some 300,000 items related to Japan's political and legal modernization in the 19th century, including the original document archives of important Japanese statesmen from the latter half of the 19th century and the early 20th century like Itō Hirobumi, Iwakura Tomomi, Sanjō Sanetomi, Mutsu Munemitsu, Terauchi Masatake, other influential figures from the Meiji and Taishō periods; the NDL has an extensive microform collection of some 30 million pages of documents relating to the Occupation of Japan after World War II. This collection include the documents prepared by General Headquarters and the Supreme Commander of the Allied Powers, the Far Eastern Commission, the United States Strategic Bombing Survey Team.
The Laws and Preliminary Records Collection consists of some 170,000 Japanese and 200,000 foreign-language documents concerning proceedings of the National Diet and the legislatures of some 70 foreign countries, the official gazettes, judicial opinions, international treaties pertaining to some 150 foreign countries. The NDL maintains a collection of some 530,000 books and booklets and 2 million microform titles relating to the sciences; these materials include, among other things, foreign doctoral dissertations in the sciences, the proceedings and reports of academic societies, catalogues of technical standards, etc. The NDL has a collection of 440,000 maps of Japan and other countries, including the topographica
University of Bonn
The University of Bonn is a public research university located in Bonn, Germany. It was founded in its present form as the Rhein University on 18 October 1818 by Frederick William III, as the linear successor of the Kurkölnische Akademie Bonn, founded in 1777; the University of Bonn offers a large number of undergraduate and graduate programs in a range of subjects and has 544 professors and 32,500 students. Its library holds more than five million volumes; as of August 2018, among its notable alumni and researchers are 10 Nobel Laureates, 4 Fields Medalists, twelve Gottfried Wilhelm Leibniz Prize winners as well as August Kekulé, Friedrich Nietzsche, Karl Marx, Heinrich Heine, Prince Albert, Pope Benedict XVI, Frederick III, Max Ernst, Konrad Adenauer, Joseph Schumpeter. The university's forerunner was the Kurkölnische Akademie Bonn, founded in 1777 by Maximilian Frederick of Königsegg-Rothenfels, the prince-elector of Cologne. In the spirit of the Enlightenment the new academy was nonsectarian.
The academy had schools for theology, law and general studies. In 1784 Emperor Joseph II granted the academy the right to award academic degrees, turning the academy into a university; the academy was closed in 1798 after the left bank of the Rhine was occupied by France during the French Revolutionary Wars. The Rhineland became a part of Prussia in 1815 as a result of the Congress of Vienna. King Frederick William III of Prussia thereafter decreed the establishment of a new university in the new province on 18 October 1818. At this time there was no university in the Rhineland, as all three universities that existed until the end of the 18th century were closed as a result of the French occupation; the Kurkölnische Akademie Bonn was one of these three universities. The other two were the Roman Catholic University of Cologne and the Protestant University of Duisburg; the new Rhein University was founded on 18 October 1818 by Frederick William III. It was the sixth Prussian University, founded after the universities in Greifswald, Berlin, Königsberg and Breslau.
The new university was shared between the two Christian denominations. This was one of the reasons why Bonn, with its tradition of a nonsectarian university, was chosen over Cologne and Duisburg. Apart from a school of Roman Catholic theology and a school of Protestant theology, the university had schools for medicine and philosophy. 35 professors and eight adjunct professors were teaching in Bonn. The university constitution was adopted in 1827. In the spirit of Wilhelm von Humboldt the constitution emphasized the autonomy of the university and the unity of teaching and research. Similar to the University of Berlin, founded in 1810, the new constitution made the University of Bonn a modern research university. Only one year after the inception of the Rhein University the dramatist August von Kotzebue was murdered by Karl Ludwig Sand, a student at the University of Jena; the Carlsbad Decrees, introduced on 20 September 1819 led to a general crackdown on universities, the dissolution of the Burschenschaften and the introduction of censorship laws.
One victim was the author and poet Ernst Moritz Arndt, freshly appointed university professor in Bonn, was banned from teaching. Only after the death of Frederick William III in 1840 was he reinstated in his professorship. Another consequence of the Carlsbad Decrees was the refusal by Frederick William III to confer the chain of office, the official seal and an official name to the new university; the Rhein University was thus nameless until 1840, when the new King of Prussia, Frederick William IV gave it the official name Rheinische Friedrich-Wilhelms-Universität. Despite these problems, the university attracted famous scholars and students. At the end of the 19th century the university was known as the Prinzenuniversität, as many of the sons of the king of Prussia studied here. In 1900, the university had 68 chairs, 23 adjunct chairs, two honorary professors, 57 Privatdozenten and six lecturers. Since 1896, women were allowed to attend classes as guest auditors at universities in Prussia. In 1908 the University of Bonn became coeducational.
The growth of the university came to a halt with World War I. Financial and economic problems in Germany in the aftermath of the war resulted in reduced government funding for the university; the University of Bonn responded by trying to find industrial sponsors. In 1930 the university adopted a new constitution. For the first time students were allowed to participate in the self-governing university administration. To that effect the student council Astag was founded in the same year. Members of the student council were elected in a secret ballot. After the Nazi takeover of power in 1933, the Gleichschaltung transformed the university into a Nazi educational institution. According to the Führerprinzip the autonomous and self-governening administration of the university was replaced by a hierarchy of leaders resembling the military, with the university president being subordinate to the ministry of education. Jewish professors and students and political opponents were ostracized and expelled from the university
Walther Flemming was a German biologist and a founder of cytogenetics. He was born in Sachsenberg as the fifth child and only son of the psychiatrist Carl Friedrich Flemming and his second wife, Auguste Winter, he graduated from the Gymnasium der Residenzstadt, where one of his colleagues and lifelong friends was writer Heinrich Seidel. Flemming trained in medicine at The University of Prague, graduating in 1868. Afterwards, he served in 1870–71 as a military physician in the Franco-Prussian War. From 1873 to 1876 he worked as a teacher at the University of Prague. In 1876 he accepted a post as a professor of anatomy at the University of Kiel, he stayed there until his death. With the use of aniline dyes he was able to find a structure which absorbed basophilic dyes, which he named chromatin, he identified that chromatin was correlated to threadlike structures in the cell nucleus – the chromosomes, which were named thus by German anatomist Wilhelm von Waldeyer-Hartz. The Belgian scientist Edouard Van Beneden had observed them, independently.
Flemming investigated the process of cell division and the distribution of chromosomes to the daughter nuclei, a process he called mitosis from the Greek word for thread. However, he did not see the splitting into identical halves, the daughter chromatids, he studied mitosis both in vivo and in stained preparations, using as the source of biological material the fins and gills of salamanders. These results were published first in 1878 and in 1882 in the seminal book Zellsubstanz, Kern und Zelltheilung. On the basis of his discoveries, Flemming surmised for the first time that all cell nuclei came from another predecessor nucleus. Flemming is famously known for the work outside of his work, he weekly fed those who were homeless, donating 20 % of his salary to homeless shelters. He taught young children who were too poor to attend school about mathematics and science. Flemming was unaware of the work of Gregor Mendel on heredity, so he did not make the connection between his observations and genetic inheritance.
Two decades would pass before the significance of Flemming's work was realized with the rediscovery of Mendel's rules. The Science Channel named Flemming's discovery of mitosis and chromosomes as one of the 100 most important scientific discoveries of all time, one of the 10 most important discoveries in cell biology. Flemming's name is honoured by a medal awarded by the German Society for Cell Biology. Lukács. "Walter Flemming, discoverer of chromatin and mitotic cell division". Orvosi hetilap. 122: 349–50. PMID 7015236. Latronico. "Heredity and diathesis". Minerva pediatrica. 52: 81–115. PMID 10829597. Breathnach. "Biographical sketches No. 18—Flemming". Irish Medical Journal. 75: 177. PMID 7050007. Paweletz. "Walther Flemming: pioneer of mitosis research". Nature Reviews. Molecular Cell Biology. 2: 72–5. Doi:10.1038/35048077. PMID 11413469. Flemming, Walther. "Beitrage zur Kenntniss der Zelle und ihrer Lebenserscheinungen". Archiv für Mikroskopische Anatomie. 16: 302. Doi:10.1007/BF02956386. and Flemming, Walther.
"Beiträge zur Kenntniss der Zelle und Ihrer Lebenserscheinungen". Archiv für Mikroskopische Anatomie. 18: 151. Doi:10.1007/BF02952594. Reprinted in J. Cell Biol. 25:581–589. Flemming, W. Zur Kenntniss der Zelle und ihrer Theilungs-Erscheinungen. In: Schriften des Naturwissenschaftlichen Vereins für Schleswig-Holstein 3, 23–27. Carlson, E. A; the Analysis of Mitosis Shifts Attention to the Chromosomes. In: Mendel's Legacy; the Origins of Classical Genetics. P. 24-5, CSHL Press, 2004. ISBN 0-87969-675-3. Walther Flemming Biography. Lasker Labs Zellsubstanz, Kern und Zelltheilung. Original text of the book, as PDF. Walter Flemming Medaille. In PDF, in German. Hardy, P. A. Zacharias, H.: Walther Flemming und die Mitose: Der Beitrag seiner ersten Kieler Jahre. Schr. Naturwiss. Ver. Schlesw.-Holst. 70, 3–15. Paper about his first description of mitosis. In German. "Walther Flemming und die Mitose: Der Beitrag seiner ersten Kieler Jahre". Retrieved 2010-03-16