816 resultados para Afro-Asian solidarity
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EXTRACT (SEE PDF FOR FULL ABSTRACT): Whole-core magnetic susceptibility can sometimes be used as a rapid and sensitive indicator of variations in the concentration of terrigenous material. We apply this approach to study the evolution of Plio-Pleistocene climatic cycles of terrigenous sedimentation at Ocean Drilling Program Site 721, on the Owen Ridge in the Arabian Sea.
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The stable isotopic composition of buried soil carbonate and organic matter from northern Pakistan and Nepal can be used to reconstruct aspects of the paleoecology of riverine floodplain ecosystems over the past 17 Myr. Probable dry woodland dominated the floodplain biomass of large rivers ancestral to the modern Indus and Ganges up to 7.3 Myr. Between 7.3 and about 6 Myr, tropical grasses gradually displaced woodland and have dominated floodplain biomasses to the present. The paleovegetational transition beginning about 7.3 Myr likely signals the onset of the strongly seasonal precipitation pattern that typifies the monsoonal climate of the region today. One possible analog to the dry woodland soils of the Miocene are found under the Sal woodlands of the northern Indian subcontinent, while undisturbed modern analogs to the Plio-Pleistocene floodplain grasslands can still be found in the Chitwan area of southern Nepal.
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EXTRACT (SEE PDF FOR FULL ABSTRACT): Recent analyses of terrestrial (pollen) and marine microfossils (foraminifera and radiolaria) in cores V28-204 and RC14-99 from the northwest Pacific Ocean extend the continuous, chronostratigraphically-controlled records of the regional vegetation of the Pacific coast of Japan and offshore marine environments through three full glacial cycles. The high-resolution pollen time series show systematic relationships between fluctuations in Japanese vegetation and global ice volume over the last 350 kyr. ... Comparison with solar insolation at 30°N and with an index of orbital parameters suggests that variation in northeast Asian summer monsoon intensity is related to orbital forcing.
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How do tropical heating fluctuations create North American climate anomalies? We propose some answers using the results from a simplified global atmospheric model. We find that the South Asian-tropical west Pacific area is especially effective at stimulating North American responses. The relatively strong tropical/extratropical interaction between these two areas is the result of two major processes acting on the Rossby wave signal induced by the tropical heating fluctuations. These factors are: 1) Wave guiding by the Asian-north Pacific subtropical jet; and 2) Wave amplification within unstable regions of the jet flank. These factors allow relatively small, remote, and short-term tropical fluctuations to have relatively large impacts on North American climate.
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Asian seabass, Lates calcarifer (Bloch) - a catadromous centropomid perch, is a good candidate species for brackishwater aquaculture in India. The length-weight relationship and the relative condition of L. calcarifer were assessed under culture condition. The length of the fish samples ranged from 25 to 240 mm and the relative condition (w sub(r)) of the fish for different length groups ranged from 99.54 to 104.39, indicating the good condition of the fish. The regression analysis of log-transformed length-weight data was carried out and the 'b' coefficient indicates the good condition of fish showing an isometric growth in the juvenile phase under culture condition.
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Aquatic insects are relatively common at artificial lights and are often taken in light traps operated for catching other insects. They are however seldom recorded. These records are however of importance in understanding their distribution and abundance. Aquatic Coleoptera and Hemiptera are of importance in fisheries because some of them are predators on small fish whilst others serve as food for fishes of all sizes. Some like the Corixidae are of special interest because they can utilize the bottom ooze which is abundant especially in small habitats. Fernando (1961a) gave a comprehensive bibliography of records at light. In the present paper a number of records are given from various parts of Asia, where in the past records were very few. They are based on collections made by the author and also on material in the Zoological Survey of India, Calcutta. Amongst specimens sent for study by the Bernice P. Bishop Museum, Honolulu, were a few specimens which had been recorded at light.
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The prehistoric peopling of East Asia by modern humans remains controversial with respect to early population migrations. Here, we present a systematic sampling and genetic screening of an East Asian-specific Y-chromosome haplogroup (O3-M122) in 2,332 individuals from diverse East Asian populations. Our results indicate that the O3-M122 lineage is dominant in East Asian populations, with an average frequency of 44.3%. The microsatellite data show that the O3-M122 haplotypes in southern East Asia are more diverse than those in northern East Asia, suggesting a southern origin of the O3-M122 mutation. It was estimated that the early northward migration of the O3-M122 lineages in East Asia occurred similar to 25,000-30,000 years ago, consistent with the fossil records of modern humans in East Asia.
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Background: The emergence of agriculture about 10,000 years ago marks a dramatic change in human evolutionary history. The diet shift in agriculture societies might have a great impact on the genetic makeup of Neolithic human populations. The regionally restricted enrichment of the class I alcohol dehydrogenase sequence polymorphism (ADH1BArg47His) in southern China and the adjacent areas suggests Darwinian positive selection on this genetic locus during Neolithic time though the driving force is yet to be disclosed. Results: We studied a total of 38 populations (2,275 individuals) including Han Chinese, Tibetan and other ethnic populations across China. The geographic distribution of the ADH1B*47His allele in these populations indicates a clear east-to-west cline, and it is dominant in south-eastern populations but rare in Tibetan populations. The molecular dating suggests that the emergence of the ADH1B*47His allele occurred about 10,000 similar to 7,000 years ago. Conclusion: We present genetic evidence of selection on the ADH1BArg47His polymorphism caused by the emergence and expansion of rice domestication in East Asia. The geographic distribution of the ADH1B*47His allele in East Asia is consistent with the unearthed culture relic sites of rice domestication in China. The estimated origin time of ADH1B*47His allele in those populations coincides with the time of origin and expansion of Neolithic agriculture in southern China.
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Some lepidopteran lysozymes have been reported to display activity against Gram-positive and Gram-negative bacteria, in contrast to most lysozymes that are active only against Gram-positive bacteria. OstrinLysC, a c-type lysozyme, was purified from the As
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The classification and phylogenetic relationships of the Old World monkeys are still controversial. For Asian colobines, from three to nine genera were recognized by different primatologists. In the present study, we have sequenced a 424 bp mitochondrial tRNA(Thr) gene and cytochrome b gene fragment from Macaca mulatta, Mandrillus sphinx, Mandrillus leucophaeus, Semnopithecus entellus, Trachypithecus vetulus, T. johnii, T. phayrei, T. francoisi, Pygathrix nemaeus, Rhinopithecus roxellanae, R. bieti, R. avunculus, Nasalis larvatus, and Colobus polykomos in order to gain independent information on the classification and phylogenetic relationships of those species. Phylogenetic trees were constructed with parsimony analysis by weighting transversions 5 or 10 fold greater than transitions. Our results support the following conclusions: (1) the Old World monkeys are divided into two subfamilies; (2) that among the colobines, Colobus, the African group, diverged first, and Nasalis and Rhinopithecus form a sister clade to Pygathrix; (3) that there are two clades within leaf monkeys, i.e. 1) S. entellus, T. johnii, and T. vetulus, and 2) T, phayrei and T. francoisi; (4) that Rhinopithecus avunculus, R. roxellanae, and R. bieti are closely related to each other, and they should be placed into the same subgenus; (5) that Rhinopithecus is a distinct genus; and (6) that the ancestors of Asian colobines migrated from Africa to Asia during the late Pliocene or early Pleistocene.
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The origin of the domestic dog from wolves has been established, but the number of founding events, as well as where and when these occurred, is not known. To address these questions, we examined the mitochondrial DNA (mtDNA) sequence variation among 654
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The now-emerging mitochondrial DNA ( mtDNA) population genomics provides information for reconstructing a well-resolved mtDNA phylogeny and for discerning the phylogenetic status of the subcontinentally specific haplogroups. Although several major East Asian mtDNA haplogroups have been identified in studies elsewhere, some of the most basal haplogroups, as well as numerous minor subhaplogroups, were not yet determined or fully characterized. To fill the lacunae, we selected 48 mtDNAs from >2,000 samples across China for complete sequencing that cover virtually all ( sub) haplogroups discernible to date in East Asia. This East Asian mtDNA phylogeny can henceforth serve as a solid basis for phylogeographic analyses of mtDNAs, as well as for studies of mitochondrial diseases in East and Southeast Asia.