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Piotr Pavlovich Ivanov
Piotr Pavlovich Ivanov (russian: Петр Павлович Иванов; 9 April 1878 – 15 February 1942) was a Soviet embryologist and a professor. He studied segmentation in annelids and arthropods and proposed the differentiation of two kinds of segments in segmented organisms and the developmental (or ontogenetic) idea of heteronomous metamery where several segments fuse to perform a common function. Life and work Ivanov was born in St. Petersburg where his father Pavel worked in the Volga-Kama bank. He graduated from the 1st classical gymnasium in 1896 and joined St. Petersburg University where he studied zoology under Vladimir Shevyakov. His research was on the regeneration of segments in the worm ''Lumbriculus variegatus ''Lumbriculus variegatus'', also known as the blackworm or California blackworm, is a species of worm inhabiting North America and Europe. It lives in shallow-water marshes, ponds, and swamps, feeding on microorganisms and organic material. The ... ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ivanov Petr Pavlovich
Ivanov, Ivanoff or Ivanow (masculine, bg, Иванов, russian: ИвановSometimes the stress is on Ива́нов in Bulgarian if it is a middle name, or in Russian as a rare variant of pronunciation), or Ivanova (feminine, bg, Иванова, russian: Иванова) is one of the most common surnames in Russia and Bulgaria. The surname is derived from the male given name Ivan (related to John) and literally means "Ivan's". People with the surname * Alena Ivanova, Kazakhstani volleyball player *Alexander Ivanov (other) – several people * Alexey Ivanov (other) – several people *Alina Ivanova (born 1969), Russian race walker and long-distance runner * Allen Ivanov, American mass shooter, responsible for the 2016 Mukilteo shooting * Almaz Ivanov (died 1669), Russian statesman *Alexander Andreyevich Ivanov (1806-1858), Russian painter *Anatoli Ivanov (musician) (1934–2012), Russian solo-timpanist and percussionist with the Saint Petersburg Philharmonic Or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metamerism (biology)
In biology, metamerism is the phenomenon of having a linear series of body segments fundamentally similar in structure, though not all such structures are entirely alike in any single life form because some of them perform special functions. In animals, metameric segments are referred to as somites or metameres. In plants, they are referred to as metamers or, more concretely, phytomers. In animals In animals, zoologists define metamery as a mesodermal event resulting in serial repetition of unit subdivisions of ectoderm and mesoderm products. Endoderm is not involved in metamery. Segmentation is not the same concept as metamerism: segmentation can be confined only to ectodermally derived tissue, e.g., in the Cestoda tapeworms. Metamerism is far more important biologically since it results in metameres - also called somites - that play a critical role in advanced locomotion. One can divide metamerism into two main categories: * homonomous metamery is a strict serial succes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saint Petersburg
Saint Petersburg ( rus, links=no, Санкт-Петербург, a=Ru-Sankt Peterburg Leningrad Petrograd Piter.ogg, r=Sankt-Peterburg, p=ˈsankt pʲɪtʲɪrˈburk), formerly known as Petrograd (1914–1924) and later Leningrad (1924–1991), is the second-largest city in Russia. It is situated on the Neva River, at the head of the Gulf of Finland on the Baltic Sea, with a population of roughly 5.4 million residents. Saint Petersburg is the fourth-most populous city in Europe after Istanbul, Moscow and London, the most populous city on the Baltic Sea, and the world's northernmost city of more than 1 million residents. As Russia's Imperial capital, and a historically strategic port, it is governed as a federal city. The city was founded by Tsar Peter the Great on 27 May 1703 on the site of a captured Swedish fortress, and was named after apostle Saint Peter. In Russia, Saint Petersburg is historically and culturally associated with t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saint Petersburg State University
Saint Petersburg State University (SPBU; russian: Санкт-Петербургский государственный университет) is a public research university in Saint Petersburg, Russia. Founded in 1724 by a decree of Peter the Great, the university from the beginning has had a focus on fundamental research in science, engineering and humanities. During the Soviet period, it was known as Leningrad State University (russian: Ленинградский государственный университет). It was renamed after Andrei Zhdanov in 1948 and was officially called "Leningrad State University, named after A. A. Zhdanov and decorated with the Order of Lenin and the Order of the Red Banner of Labour." Zhdanov's was removed in 1989 and Leningrad in the name was officially replaced with Saint Petersburg in 1992. It is made up of 24 specialized faculties (departments) and institutes, the Academic Gymnasium, the Medical College, the College of Physical Culture ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vladimir Shevyakov
Vladimir Timofeyevich Shevyakov, in Russian Владимир Тимофеевич Шевяков (29 October 1859, St. Petersburg – 18 October 1930, Irkutsk) was a Russian biologist who worked on Protozoa. Shevyakov studied under Konstantin Mereschkowski in St. Petersburg and Otto Bütschli at the University of Heidelberg. He was married to Lydia Kowalevsky, the youngest daughter of Alexander Kovalevsky. He was a professor at St. Petersburg University until 1911 when he left science and became a vice-minister in the government of Tzar Nicholas. During the revolution he and his family moved first to Perm in Ural and in 1920 he became professor in Irkutsk. He is mainly known for his work on Radiolaria, Ciliata and Acantharea. He described many taxa. Most of his publications are under the German spelling of his name which is Schewiakoff. Works Über die karyokinetische Kerntheilung der ''Euglypha alveolata'' "Morphologische Jahrbuch" 13, ss. 193–258 (1888) * Man wüns ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lumbriculus Variegatus
''Lumbriculus variegatus'', also known as the blackworm or California blackworm, is a species of worm inhabiting North America and Europe. It lives in shallow-water marshes, ponds, and swamps, feeding on microorganisms and organic material. The maximum length of a specimen is 10 cm (4 in). Worms raised in laboratory environment are slightly shorter, with 4 to 6 cm (1.57 - 2.36 in) long bodies. An adult individual has approximately 150 to 250 1.5 mm wide segments, each of which has the ability to regenerate into a new individual when separated from the rest of the animal. In most populations, this is the primary mode of reproduction, and mature individuals are exceedingly rare; in large areas (including Asia, most of North America and the greater part of Europe) mature individuals have never been found. The name ''blackworm'' is given to at least three distinct species of worm that are identical in appearance and were once considered a single species. Characteristics Among th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stazione Zoologica Anton Dohrn
The Stazione Zoologica Anton Dohrn is a research institute in Naples, Italy, devoted to basic research in biology. Research is largely interdisciplinary involving the fields of evolution, biochemistry, molecular biology, neurobiology, cell biology, biological oceanography, marine botany, molecular plant biology, benthic ecology, and ecophysiology. Founded in 1872 as a private concern by Anton Dohrn, in 1982 the Stazione Zoologica came under the supervision and control of the Ministero dell'Università e della Ricerca Scientifica e Tecnologica (Ministry of Universities and Scientific and Technological Research) as a National Institute. History The idea Dohrn's idea was to establish an international scientific community provided with laboratory space, equipment, research material and a library. This was supported and funded by the German Government, Thomas Henry Huxley, Charles Darwin, Francis Balfour and Charles Lyell among others. Dohrn provided a substantial sum himself. Ru ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xiphosura
Xiphosura () is an order of arthropods related to arachnids. They are more commonly known as horseshoe crabs (a name applied more specifically to the only extant family, Horseshoe crab, Limulidae). They first appeared in the Hirnantian (Late Ordovician). Currently, there are only four living species. Xiphosura contains one suborder, Xiphosurida, and several stem-genera. The group has hardly changed in appearance in hundreds of millions of years; the modern horseshoe crabs look almost identical to prehistoric genera and are considered to be living fossils. The most notable difference between ancient and modern forms is that the abdominal segments in present species are fused into a single unit in adults. Xiphosura were historically placed in the class Merostomata, although this term was intended to encompass also the Eurypterida, eurypterids, whence it denoted what is now known to be an unnatural (paraphyletic) group (although this is a grouping recovered in some recent cladistic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scolopendra
''Scolopendra'' (through Latin from Greek , ''skolopendra'') is a species-rich genus of large tropical centipedes of the family Scolopendridae. Description The genus ''Scolopendra'' contains many species of centipedes found across the world's tropics and warmer temperate areas. The species vary considerably in coloration and size. ''Scolopendra'' are mostly very large centipedes. The largest species found in tropical climates can exceed and are the largest living centipedes in the world. All ''Scolopendra'' species can deliver a painful bite, injecting venom through their forcipules, which are not fangs or other mouthparts; rather, these are modified legs on the first body segment. Ecology ''Scolopendra'' are active predators, feeding primarily on insects and other invertebrates. Larger specimens have been observed preying on frogs, tarantulas, lizards, birds, snakes, rodents, and even bats. Two southeast Asian species, '' S. cataracta'' and '' S. paradoxa'', are amphibious, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Richard Hertwig
Richard Wilhelm Karl Theodor Ritter von Hertwig (23 September 1850 in Friedberg, Hesse – 3 October 1937 in Schlederloh, Bavaria), also Richard Hertwig or Richard von Hertwig, was a German zoologist and professor of 50 years, notable as the first to describe zygote formation as the fusing of spermatozoa inside the membrane of an egg cell during fertilization. "Richard von Hertwig – Wikipedia" (German), German Wikipedia, 2006-10-29, de.wikipedia.org webpage: GermanWP-Richard_von_Hertwig. Richard Hertwig was the younger brother of Oscar Hertwig, who also analyzed zygote formation. The two Hertwig brothers worked together until 1883 (more at: Oscar Hertwig). The Hertwig brothers were the most eminent scholars of Ernst Haeckel (and Carl Gegenbaur), each brother becoming a long-term professor in Germany. They were independent of Haeckel's philosophical speculations but took his ideas in a positive way to widen their concepts in zoology. Initially, between 18 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1878 Births
Events January–March * January 5 – Russo-Turkish War – Battle of Shipka Pass IV: Russian and Bulgarian forces defeat the Ottoman Empire. * January 9 – Umberto I becomes King of Italy. * January 17 – Battle of Philippopolis: Russian troops defeat the Turks. * January 23 – Benjamin Disraeli orders the British fleet to the Dardanelles. * January 24 – Russian revolutionary Vera Zasulich shoots at Fyodor Trepov, Governor of Saint Petersburg. * January 28 – ''The Yale News'' becomes the first daily college newspaper in the United States. * January 31 – Turkey agrees to an armistice at Adrianople. * February 2 – Greece declares war on the Ottoman Empire. * February 7 – Pope Pius IX dies, after a 31½ year reign (the longest definitely confirmed). * February 8 – The British fleet enters Turkish waters, and anchors off Istanbul; Russia threatens to occupy Istanbul, but does not carry out the threat. * Febru ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1942 Deaths
Year 194 ( CXCIV) was a common year starting on Tuesday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Septimius and Septimius (or, less frequently, year 947 ''Ab urbe condita''). The denomination 194 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years. Events By place Roman Empire * Emperor Septimius Severus and Decimus Clodius Septimius Albinus Caesar become Roman Consuls. * Battle of Issus: Septimius Severus marches with his army (12 legions) to Cilicia, and defeats Pescennius Niger, Roman governor of Syria. Pescennius retreats to Antioch, and is executed by Severus' troops. * Septimius Severus besieges Byzantium (194–196); the city walls suffer extensive damage. Asia * Battle of Yan Province: Warlords Cao Cao and Lü Bu fight for control over Yan Province; the battle lasts for over 100 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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