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Pyxine Lilacina
''Pyxine lilacina'' is a rare species of saxicolous (rock-dwelling), foliose lichen in the family Caliciaceae. Found in East Africa, it was scientifically described as a new species in 1975 by lichenologists Dougal Swinscow and Hildur Krog. The lichen has a brownish-grey to lilac-grey thallus that is tightly appressed to its substrate. The comprising the thallus are flat, and have pseudocyphellae (tiny pores for air exchange) as well as patches of pruina. The thallus underside is black; the internal medulla is white. The lichen contains triterpenoid compounds as well as lichexanthone; the latter substance causes the lichen to fluoresce when lit with a long-wavelength UV light. ''Pyxine lilacina'' is only known to occur in Uganda and Kenya ) , national_anthem = "Ee Mungu Nguvu Yetu"() , image_map = , map_caption = , image_map2 = , capital = Nairobi , coordinates = , largest_city = Nairobi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thomas Douglas Victor Swinscow
Thomas Douglas (Dougal) Victor Swinscow (1917 - 1992) was the founder of the British Lichen Society and the scientific journal ''The Lichenologist''. He was also a member of the editorial team of the British Medical Journal and deputy editor from 1964 until 1977. Early life and education Swinscow's parents were Nellie (née Alleyne) and William Sprague Swinscow. As a child Swinscow explored his home area of Devon and developed his interest in natural history. He was educated at the private boys school Kelly College, Tavistock, Devon. He completed a bachelor degree in medicine at St Thomas's Hospital Medical School in 1939 and subsequently became a licentiate of the Royal College of Physicians, London and was registered as a member of the Royal College of Surgeons. In 1962 he was awarded an M. Sc degree University of London for his studies on the lichen ''Porina''. Career After finishing his medical qualification, and working as a house surgeon at Woking Hospital he joined the Roy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lichexanthone
Lichexanthone is an organic compound in the structural class of chemicals known as xanthones. Lichexanthone was first isolated and identified by Japanese chemists from a species of leafy lichen in the 1940s. The compound is known to occur in many lichens, and it is important in the taxonomy of species in several genera, such as ''Pertusaria'' and ''Pyxine''. More than a dozen lichen species have a variation of the word lichexanthone incorporated as part of their binomial name. The presence of lichexanthone in lichens causes them to fluoresce a greenish-yellow colour under long-wavelength UV light; this feature is used to help identify some species. Lichexanthone is also found in several plants (many are from the families Annonaceae and Rutaceae), and some species of fungi that do not form lichens. In lichens, the biosynthesis of lichexanthone occurs through a set of enzymatic reactions that start with the molecule acetyl-CoA and sequentially add successive units, forming a longe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lichens Of East Tropical Africa
A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship.Introduction to Lichens – An Alliance between Kingdoms . University of California Museum of Paleontology. Lichens have properties different from those of their component organisms. They come in many colors, sizes, and forms and are sometimes plant-like, but are not s. They may have tiny, leafless branches (); flat leaf-like structures ( |
Lichens Described In 1975
A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship.Introduction to Lichens – An Alliance between Kingdoms . University of California Museum of Paleontology. Lichens have properties different from those of their component organisms. They come in many colors, sizes, and forms and are sometimes plant-like, but are not s. They may have tiny, leafless branches (); flat leaf-like structures ( |
Lichen Species
A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship.Introduction to Lichens – An Alliance between Kingdoms . University of California Museum of Paleontology. Lichens have properties different from those of their component organisms. They come in many colors, sizes, and forms and are sometimes plant-like, but are not s. They may have tiny, leafless branches (); flat leaf-like structures ( |
Pyxine
''Pyxine'' is a genus of foliose lichens in the family Caliciaceae. The genus has a widespread distribution in tropical regions. The presence or absence of the compound lichexanthone is a character Character or Characters may refer to: Arts, entertainment, and media Literature * ''Character'' (novel), a 1936 Dutch novel by Ferdinand Bordewijk * ''Characters'' (Theophrastus), a classical Greek set of character sketches attributed to The ... used in classifying ''Pyxine '' species; about 20 species contain this compound. This represents the largest group of foliose lichens with the compound. Species *'' Pyxine albovirens'' *'' Pyxine astipitata'' – Brazil *'' Pyxine astridiana'' – neotropical *'' Pyxine australiensis'' – Asia; Australia *'' Pyxine berteriana'' – pantropical *'' Pyxine boonpragobiana'' – Thailand *'' Pyxine coccifera'' *'' Pyxine cocoes'' *'' Pyxine cognata'' - pantropical *'' Pyxine consocians'' *'' Pyxine convexior'' *'' Pyxine copela ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kenya
) , national_anthem = "Ee Mungu Nguvu Yetu"() , image_map = , map_caption = , image_map2 = , capital = Nairobi , coordinates = , largest_city = Nairobi , official_languages = Constitution (2009) Art. 7 ational, official and other languages"(1) The national language of the Republic is Swahili. (2) The official languages of the Republic are Swahili and English. (3) The State shall–-–- (a) promote and protect the diversity of language of the people of Kenya; and (b) promote the development and use of indigenous languages, Kenyan Sign language, Braille and other communication formats and technologies accessible to persons with disabilities." , languages_type = National language , languages = Swahili , ethnic_groups = , ethnic_groups_year = 2019 census , religion = , religion_year = 2019 census , demonym = ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Uganda
}), is a landlocked country in East Africa East Africa, Eastern Africa, or East of Africa, is the eastern subregion of the African continent. In the United Nations Statistics Division scheme of geographic regions, 10-11-(16*) territories make up Eastern Africa: Due to the historical .... The country is bordered to the east by Kenya, to the north by South Sudan, to the west by the Democratic Republic of the Congo, to the south-west by Rwanda, and to the south by Tanzania. The southern part of the country includes a substantial portion of Lake Victoria, shared with Kenya and Tanzania. Uganda is in the African Great Lakes region. Uganda also lies within the Nile, Nile basin and has a varied but generally a modified equatorial climate. It has a population of around 49 million, of which 8.5 million live in the Capital city, capital and largest city of Kampala. Uganda is named after the Buganda kingdom, which encompasses a large portion of the south of the country, includi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
UV Light
Ultraviolet (UV) is a form of electromagnetic radiation with wavelength from 10 nm (with a corresponding frequency around 30 PHz) to 400 nm (750 THz), shorter than that of visible light, but longer than X-rays. UV radiation is present in sunlight, and constitutes about 10% of the total electromagnetic radiation output from the Sun. It is also produced by electric arcs and specialized lights, such as mercury-vapor lamps, tanning lamps, and black lights. Although long-wavelength ultraviolet is not considered an ionizing radiation because its photons lack the energy to ionize atoms, it can cause chemical reactions and causes many substances to glow or fluoresce. Consequently, the chemical and biological effects of UV are greater than simple heating effects, and many practical applications of UV radiation derive from its interactions with organic molecules. Short-wave ultraviolet light damages DNA and sterilizes surfaces with which it comes into contact. For huma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fluoresce
Fluorescence is the emission of light by a substance that has absorbed light or other electromagnetic radiation. It is a form of luminescence. In most cases, the emitted light has a longer wavelength, and therefore a lower photon energy, than the absorbed radiation. A perceptible example of fluorescence occurs when the absorbed radiation is in the ultraviolet region of the electromagnetic spectrum (invisible to the human eye), while the emitted light is in the visible region; this gives the fluorescent substance a distinct color that can only be seen when the substance has been exposed to UV light. Fluorescent materials cease to glow nearly immediately when the radiation source stops, unlike phosphorescent materials, which continue to emit light for some time after. Fluorescence has many practical applications, including mineralogy, gemology, medicine, chemical sensors (fluorescence spectroscopy), fluorescent labelling, dyes, biological detectors, cosmic-ray detection, vacuu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triterpenoid
Triterpenes are a class of chemical compounds composed of three terpene units with the molecular formula C30H48; they may also be thought of as consisting of six isoprene units. Animals, plants and fungi all produce triterpenes, including squalene, the precursor to all steroids. Structures Triterpenes exist in a great variety of structures. Nearly 200 different skeletons have been identified. These skeletons may be broadly divided according to the number of rings present. In general pentacyclic structures (5 rings) tend to dominate. Squalene is biosynthesized through the head-to-head condensation of two farnesyl pyrophosphate units. This coupling converts a pair of C15 components into a C30 product. Squalene serves as precursor for the formation of many triterpenoids, including bacterial hopanoids and eukaryotic sterols. Triterpenoids By definition triterpenoids are triterpenes that possess heteroatoms, usually oxygen. The terms ''triterpene'' and ''triterpenoid'' ofte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hildur Krog
Hildur Krog (22 March 1922 – 25 August 2014) was a Norwegian botanist. She was born in Modum. She took the dr.philos. degree in 1968 with a thesis on Alaskan lichens, was hired as a curator at the Botanical Museum of Oslo in 1971 and served as professor at the University of Oslo from 1987 to 1992. For 15 year from 1969 she collaborated with the British amateur lichenologist Dougal Swinscow to study the macrolichen flora of East Africa. They undertook field collections as well as characterisation and revision of the limited existing lichen knowledge of the region, presented in 33 scientific publications and a book ''The Macrolichens of East Africa'', British Museum (Natural History) in 1988. In 1992 Hildur Krog was awarded the Acharius Medal by the International Association for Lichenology She was a fellow of the Norwegian Academy of Science and Letters. She died in 2014. Several lichen are named in her honour, including ''Krogia'' which a genus of corticolous lichens in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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