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1.
The author has surveyed the diversity of lichen biota of West Siberia and distribution of lichens over its two geographic parts: the West Siberian Plain and the mountain frame in the south of West Siberia. The diversity of lichen biota in entire West Siberia is currently estimated at 1845 species in 325 genera and 95 families. The diversity of the West Siberian Plain is estimated at 1421 species in 271 genera and 86 families, and that of the southern mountains of West Siberia, at 1682 species in 312 genera and 94 families.  相似文献   

2.
Western Europe is a reinvasion zone for the riverine dragonfly genus Calopteryx (Insecta: Odonata). Reinvasion may have been from central West Asia or from the West Mediterranean refugium. Phylogenetic relationships of West Mediterranean and West European taxa of the genus Calopteryx from different localities were inferred from sequences of the internal transcribed spacers (ITS1 and ITS2) of the nuclear ribosomal RNA genes. Twenty-six taxa belonging to the species groups C. splendens, C. meridionalis, C. haemorrhoidalis, C. virgo, C. xanthostoma, and C. exul were analyzed, with two North American species, C. amata and C. aequabilis, as outgroup. Sequence data and phylogenetic analyses were used to infer biogeographical patterns. The ribosomal spacers (ITS1 and ITS2) and the intervening 5.8S rDNA gene were amplified by PCR and sequenced. The ITS2 sequences of the West Mediterranean and West European calopterygids show no length variation but the ITS1 region was slightly variable in length. The sequence variation for ITS1 and ITS2 regions between different West Mediterranean and West European calopterygids was 14.5 and 6.1%, respectively. Phylogenetic relationships inferred from ITS sequences only partly confirm morphological data. A monophyletic origin of all West Mediterranean and West European species emerged. They are separated into two main clades; the splendens-like forms and the virgo/meridionalis/haemorrhoidalis group. Intraspecific variability, indicating different stages of speciation, was detected only in West Mediterranean representatives (e.g., C. xanthostoma) but not in invasive representatives in West Europe. The North African endemic C. exul is more closely related to the Italian C. s. caprai than to C. splendens sensu strictu. Based on the present information, Cretan populations are the only splendens-like taxa in addition to C. s. caprai that deserve subspecies status.  相似文献   

3.
West Nile virus, which was recently introduced to North America, is a mosquito-borne pathogen that infects a wide range of vertebrate hosts, including humans. Several species of birds appear to be the primary reservoir hosts, whereas other bird species, as well as other vertebrate species, can be infected but are less competent reservoirs. One hypothesis regarding the transmission dynamics of West Nile virus suggests that high bird diversity reduces West Nile virus transmission because mosquito blood-meals are distributed across a wide range of bird species, many of which have low reservoir competence. One mechanism by which this hypothesis can operate is that high-diversity bird communities might have lower community-competence, defined as the sum of the product of each species’ abundance and its reservoir competence index value. Additional hypotheses posit that West Nile virus transmission will be reduced when either: (1) abundance of mosquito vectors is low; or (2) human population density is low. We assessed these hypotheses at two spatial scales: a regional scale near Saint Louis, MO, and a national scale (continental USA). We found that prevalence of West Nile virus infection in mosquito vectors and in humans increased with decreasing bird diversity and with increasing reservoir competence of the bird community. Our results suggest that conservation of avian diversity might help ameliorate the current West Nile virus epidemic in the USA  相似文献   

4.
Museums and Archaeology in West Africa. Claude Daniel Ardouin. ed. Washington, DC: Smithsonian Institution Press, 1998.178 pp.  相似文献   

5.
Floristic Richness and Affinities in the West Indies   总被引:1,自引:0,他引:1  
Comparison of the common floristic elements between the West Indies and the surrounding continents shows a mosaic of affinities that are stronger to Central America and South America as a whole than with either one of them separately or with North America. However, since only 28% of the total West Indian seed plant flora is shared with other geographic regions of the world, the referred exercise is of limited value. Numerous tables are provided to show the distribution of genera throughout the archipelago. The application of phylogenetic studies into the service of biogeography is herein regarded as the next necessary step in elucidating the origins and affinities of the West Indian flora.
Pedro Acevedo-RodríguezEmail:
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6.
Remotely Global: Village Modernity in West Africa. Charles Piot. Chicago: University of Chicago Press, 1999. 220 pp.  相似文献   

7.
Kurane I 《Uirusu》2005,55(1):63-68
West Nile virus maintains natural infection cycle between birds and mosquitoes. It has been known that about 200 species of birds are infected with West Nile virus and the virus is isolated from more than 40 species of mosquitoes. This suggests that West Nile virus has an ability to be transmitted by many species of mosquitoes and infect many kinds of animals. Approximately 20% of infected humans develop symptoms. West Nile fever, an acute febrile illness, is the main disease, and meningitis and encephalitis (meningoencephalitis) occasionally occur. Cases with flaccid paralysis or polyneuritis have been recently reported. Thus, West Nile virus causes multiple types of symptoms in humans. The endemic area has expanded in North America and Siberia. West Nile virus may enter Japan in the near future; therefore, we should keep paying attention to the endemic and epidemic situations in the world.  相似文献   

8.
研究通过问卷法,调查了四川、重庆、贵州、新疆、内蒙、甘肃、宁夏、陕西等西部地区的民众在西部大开发中可能采取的应对方式。结果表明:在精神文明建设等九个典型问题上,不同年龄、不同职业以及不同文化程度的民众在西部大开发中的应对方式都有所不同。但是总的来说,民众应对方式倾向都是积极适应的,这对顺利开展西部大开发是有利的。  相似文献   

9.
Aim Since the opening of the Suez Canal in 1869, many tropical taxa from the Indo‐West Pacific (IWP) realm have entered the Mediterranean Sea, which is experiencing rising temperatures. My aims are: (1) to compare biogeographically this tropical transformation of the Mediterranean biota with the tropical faunas of the Mediterranean and adjacent southern European and West African seas during the Late Oligocene to Pliocene interval; (2) to infer the relative contributions of the tropical eastern Atlantic and IWP to the tropical component of the marine biota in southern Europe; and (3) to understand why West Africa is not now a major source of warm‐water species. Location Southern Europe, including the Mediterranean Sea, and the coast of tropical West Africa. Methods I surveyed the literature on fossil and living shell‐bearing molluscs to infer the sources and fates of tropical subgenus‐level taxa living in southern Europe and West Africa during the Late Oligocene to Pliocene interval. Results Ninety‐four taxa disappeared from the tropical eastern Atlantic (including the Mediterranean) but persisted elsewhere in the tropics, mainly in the IWP (81 taxa, 86%) and to a lesser extent in tropical America (36 taxa, 38%). Nine taxa inferred to have arrived in the tropical eastern Atlantic from the west after the Pliocene did not enter the Mediterranean. The modern West African fauna is today isolated from that of other parts of the marine tropics. Main conclusions Taxa now entering the Mediterranean through the Suez Canal are re‐establishing a link with the IWP that last existed 16 million years ago. This IWP element, which evolved under oligotrophic conditions and under a regime of intense anti‐predatory selection, will continue to expand in the increasingly warm and increasingly oligotrophic Mediterranean. The IWP source fauna contrasts with the tropical West African biota, which evolved under productive conditions and in a regime of less anti‐predatory specialization. Until now, the post‐Pliocene West African source area has been isolated from the Mediterranean by cold upwelling. If further warming should reduce this barrier, as occurred during the productive and warm Early Pliocene, the Mediterranean could become a meeting place for two tropical faunas of contrasting source conditions.  相似文献   

10.
Embodying Colonial Memories: Spirit Possession, Power, and the Hauka in West Africa. Paul Stoller New York: Routledge, 1995. 226 pp.  相似文献   

11.
The evolutionary history of a species is key for understanding the taxonomy and for the design of effective management strategies for species conservation. The knowledge about the phylogenetic position of the lion (Panthera leo) in West/Central Africa is largely based on mitochondrial markers. Previous studies using mtDNA only have shown this region to hold a distinct evolutionary lineage. In addition, anthropogenic factors have led to a strong decline in West/Central African lion numbers, thus, the conservation value of these populations is particularly high. Here, we investigate whether autosomal markers are concordant with previously described phylogeographic patterns, and confirm the unique position of the West/Central African lion. Analysis of 20 microsatellites and 1,454 bp of the mitochondrial DNA in 16 lion populations representing the entire geographic range of the species found congruence in both types of markers, identifying four clusters: 1) West/Central Africa, 2) East Africa, 3) Southern Africa and 4) India. This is not in line with the current taxonomy, as defined by the IUCN, which only recognizes an African and an Asiatic subspecies. There are no indications that genetic diversity in West/Central Africa lions is lower than in either East or Southern Africa, however, given this genetic distinction and the recent declines of lion numbers in this region, we strongly recommend prioritization of conservation projects in West/Central Africa. As the current taxonomic nomenclature does not reflect the evolutionary history of the lion, we suggest that a taxonomic revision of the lion is warranted.  相似文献   

12.
Metallurgy first appeared in Mesoamerica at about A.D. 800, introduced via a maritime route from Central and South America into West Mexico. During the initial period of the establishment of the technology (approximately A.D. 800 to between A.D. 1200 and 1300) technical links were closest with the metallurgies of Ecuador, Colombia, and lower Central America. During the second period of West Mexican metallurgy (A.D. 1200–1300 to the Spanish invasion) new elements from these same regional metallurgies were introduced, in addition to technical components from the metallurgy of southern Peru. Although the roots of West Mexican metallurgy lay in the metallurgies to the south, the elements that had been introduced from those areas were reinterpreted and transformed, resulting in the development of a technically original, highly inventive regional technology in West Mexico.  相似文献   

13.
Thirty-two species of Cladocera and 27 species of free-living copepods were identified in a series of samples collected in 25 localities in and around the Fouta Djalon mountains, West Africa. Beside great richness in numbers of species, the nature of the fauna is noteworthy: at least 20% of the Cladocera and 50% of the copepods are endemic to West Africa. Possible palaeoclimatological reasons for this are discussed. The cladoceran genus Streblocerus is recorded from Africa for the first time. It is an element of northern origin in the fauna of West Africa. More examples of this kind are documented among the Copepoda Cyclopoida and Harpacticoida, but the bulk of the fauna is evidently of tropical origin. In particular, great adaptive radiation is occurring in the local representatives of the genus Tropocyclops. Three new species of Parastenocaris are described; they are the first representatives of this genus found in West Africa.  相似文献   

14.
Toads of the Bufo peltocephalus Group (Anura: Bufonidae) occur throughout the Greater Antilles (Cuba to the Virgin Islands), a geographic region of relatively high endemicity. Previous morphological and immunological studies suggested that the West Indian toads are a monophyletic lineage derived from Neotropical Bufo but were unable to clarify relationships within the group. We examined the evolutionary relationships and biogeography of this group of frogs by collecting approximately 2 kb of mitochondrial DNA sequence data from eight West Indian species and selected non-West Indian species from the New World and the Old World. Our analyses support the monophyly of native West Indian toads and a New World origin for the group. Relationships among the West Indian species are less certain, but a Cuban lineage is defined in most analyses.  相似文献   

15.
Will Cresswell 《Ostrich》2018,89(2):123-129
West Africa has high bird diversity and is a crucial non-breeding area for over one-third of European breeding species, yet local capacity for ornithological research and so targeted bird conservation is perceived to be limited. I reviewed all the published literature on the Web of Science? classified as ‘ornithology’ with an accompanying keyword of a country’s name, over the last three decades, from the 16 countries within West Africa and compared it with that from 16 Western European countries. Inclusion of the country’s name as a search term identified any papers produced by local authors, and so should provide an index of local ornithological capacity. Overall only 129 papers were produced from 1987 to 2016 with West African authors (range: zero Burkina Faso to 45 Nigeria), significantly fewer compared with 12 380 with European authors (range: 71 Greece to 2 745 England). The number of papers produced increased significantly at similar rates over the three-decade period in both continents. The number of papers produced by local authors in West Africa and Europe approximately doubled each decade, but variation between countries was large, particularly in West Africa. The results are broadly the same when paper output is adjusted for the population of each country. Of the three West African countries that showed a consistent increase in numbers of locally authored ornithological papers, only Nigeria showed a highly significant increase and this increase was down to a single ornithological research institute established there in 2002. The results confirm that there is little local ornithological capacity in West Africa and this is not changing except in Nigeria, where even a single new research institute can make a significant difference because of the very low baseline.  相似文献   

16.
Mande Potters and Leatherworkers: Art and Heritage in West Africa. Barbara E. Frank. Washington, DC: Smithsonian Institution Press, 1998. 192 pp.  相似文献   

17.
In this article, I examine West African foods sold mainly in specialty grocery stores, focusing on how technologies used in food production in West Africa are referenced in the brand names and packaging of processed African foods sold in the United States. Through their association with "timeless" West African food-processing techniques, such foods evoke memories of childhood and home. Yet the transformation of West African foods through new technologies of processing, packaging, and branding reflects different time and health concerns of West African immigrants living in the United States. Through their purchase of time-saving, mass-produced, and hygienically packaged foodstuffs, which are ideologically similar to but technologically very different from the production processes and cooking in Africa, West Africans in the United States use food to maintain social relations with their particular families, hometown associations, and religious groups, while also constituting national, regional, and global connections through the reinvention of food traditions.  相似文献   

18.
A Rouamba  T Robert  A Sarr  A Ricroch 《Génome》1996,39(6):1128-1132
Genetic erosion is observed in traditional populations of onion in West Africa. The present study aimed to assess the agronomical potential for six important traits of 14 landraces collected in West Africa. A multivariate procedure was used to establish a classification within this germplasm on the basis of these traits. The phenotypic variability both within and between landraces is considerable but could be due to traditional agricultural practices still occurring in this area. Three statistically coherent clusters have been identified despite the great phenotypic variation between landraces and could be a basis for building a core collection of West African onion germplasm. This first analysis of traditional onion landraces provides convincing information regarding their agronomic potential. Key words : Allium cepa L., onion, genetic resources, diversity.  相似文献   

19.
An extant population of the long-stalked pondweed Potamogeton praelongus is reported from West Greenland for the first time. However, endocarps of the species have been recovered from up to 3500 years old lake sediments, so the species has a long history in this region. The species must have arrived in West Greenland by long distance dispersal, probably by geese migrating from NW Europe.  相似文献   

20.
The 3-aryl-2-cyanoacrylamide scaffold was designed as core pharmacophore for inhibitors of the Dengue and West Nile virus serine proteases (NS2B-NS3). A total of 86 analogs was prepared to study the structure–activity relationships in detail. Thereby, it turned out that the electron density of the aryl moiety and the central double bond have a crucial influence on the activity of the compounds, whereas the influence of substituents of the amide residue is less relevant. The para-hydroxy substituted analog was found to be the most potent inhibitor in this series with a Ki-value of 35.7 μM at the Dengue and 44.6 μM at the West Nile virus protease. The aprotinin competition assay demonstrates a direct interaction of the inhibitor molecule with active centre of the Dengue virus protease. The target selectivity was studied in a counterscreen with thrombin and found to be 2.8:1 in favor of DEN protease and 2.3:1 in favor of WNV protease, respectively.  相似文献   

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