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1.
It can be shown that considerable common ground exists between indigenous or traditional theories of contagious disease in Africa, and modern medicine, whether human or veterinary. Yet this is not recognized because of the generally low regard in which the medically trained – whether African or expatriate – hold African traditional medicine. This attitude seems to result from the assumption that African health beliefs are based on witchcraft and related supernatural thinking. I argue that this may not be so in the important domain of diseases biomedically classified as contagious; such diseases tend to be understood naturalistically. An accurate understanding of how Africans traditionally interpret contagious diseases of humans and livestock is the foundation for the design and implementation of more effective health programs.  相似文献   

2.
Perforated marine gastropod shells at the western Asian site of Skhul and the North African site of Oued Djebbana indicate the early use of beads by modern humans in these regions. The remoteness of these sites from the seashore and a comparison of the shells to natural shell assemblages indicate deliberate selection and transport by humans for symbolic use. Elemental and chemical analyses of sediment matrix adhered to one Nassarius gibbosulus from Skhul indicate that the shell bead comes from a layer containing 10 human fossils and dating to 100,000 to 135,000 years ago, about 25,000 years earlier than previous evidence for personal decoration by modern humans in South Africa.  相似文献   

3.
We characterized Apis mellifera in both native and introduced ranges using 1136 single-nucleotide polymorphisms genotyped in 341 individuals. Our results indicate that A. mellifera originated in Africa and expanded into Eurasia at least twice, resulting in populations in eastern and western Europe that are geographically close but genetically distant. A third expansion in the New World has involved the near-replacement of previously introduced "European" honey bees by descendants of more recently introduced A. m. scutellata ("African" or "killer" bees). Our analyses of spatial transects and temporal series in the New World revealed differential replacement of alleles derived from eastern versus western Europe, with admixture evident in all individuals.  相似文献   

4.
Genomic heterogeneity of AIDS retroviral isolates from North America and Zaire   总被引:54,自引:0,他引:54  
In an analysis of the genomic variation of AIDS retroviral isolates from patients living in New York, Alabama, and Zaire, restriction maps were constructed by using seven enzymes, each known to cleave the proviral DNA more than once, in conjunction with Southern blot analysis. The maps of LAV, HTLV-III, and ARV-2 as deduced from their published nucleotide sequences were included in this analysis. The results demonstrated that (i) several "signature" restriction sites were common to all isolates; (ii) with the exception of LAV and HTLV-III, the North American and European isolates were all different from one another and showed no geographical specificity; (iii) the African isolates as a group were more diverse than those from North America and Europe; and (iv) the genomic variability was concentrated within the env gene.  相似文献   

5.
This review provides a summary of botanicals and plant strengtheners that have potential uses for disease and pest management in potato and tomato cultivation in African. We discuss their possible use to prevent major diseases and pests which infest potato and tomato, such as early and late blight, bacterial wilt, potato tuber moth, and tomato leafminer. There are several examples of the successful uses of botanicals for pathogen and pest control relevant for different African climatic conditions; however, most of these studies have been conducted in vitro and often lack field verification. Plant strengtheners(substances that induce and improve crop resistance, yield, and quality) are little studied and used in Africa in comparison to North America and Europe. The possible benefits of using botanicals and plant strengtheners instead of conventional pesticides are discussed here in relation to human health and the environment as well as their modes of action and accessibility to farmers. Lack of knowledge of the composition and active ingredients of extracts, environmental concerns, uncertainties regarding stability and formulation, lack of legislation and limited support from governments, hamper the development of botanicals and plant strengtheners for use in sustainable African agriculture.  相似文献   

6.
Biotic recovery patterns after the end-Cretaceous mass extinction differ among the molluscan faunas of the North American Gulf Coast, northern Europe, northern Africa, and Pakistan and northern India. In contrast to the Gulf Coast, the other three regions lack a rapid expansion and decline of "bloom taxa" and have lower proportions of invaders early in the recovery phase. The anomalous Gulf Coast patterns, distinct from extratropical Europe and the tropical regions, provide evidence for the biogeographic and macroevolutionary complexity of biotic recoveries and may have implications for present-day biotas.  相似文献   

7.
A recent dispersal of modern humans out of Africa is now widely accepted, but the routes taken across Eurasia are still disputed. We show that mitochondrial DNA variation in isolated "relict" populations in southeast Asia supports the view that there was only a single dispersal from Africa, most likely via a southern coastal route, through India and onward into southeast Asia and Australasia. There was an early offshoot, leading ultimately to the settlement of the Near East and Europe, but the main dispersal from India to Australia approximately 65,000 years ago was rapid, most likely taking only a few thousand years.  相似文献   

8.
Traditional forms of farming, herding, and fishing are remarkably adapted to African conditions but these traditional approaches are being overtaken by modern pressures, particularly population growth. According to a report published by the Office of Technology Assessment (OTA), a nonpartisan analytical support agency of the U. S. Congress, one promising way to help African farmers and herders would be for development assistance organizations to focus more attention on the various forms of low-resource agriculture that predominate in Africa. In keeping with OTA's mission and primary audience, “Enhancing Agriculture in Africa: A Role for U. S. Development Assistance” (1988) is a policy-oriented synthesis of available technical information. The report provides Congress with a range of options that, if pursued, could help Africans enhance agriculture, increase their food security, and improve their lives. This paper is drawn from the larger OTA report, and it focuses on the role technology might play in enhancing low-resource agriculture. Readers should see the full assessment (OTA, 1988) for more information on policy considerations; the specific technologies mentioned; or a complete list of advisory panel members, workshops and participants, and commissioned papers. OTA's report comes at a critical time: for a variety of reasons—ranging from changing values to increased budget constraints—U. S. foreign assistance policy is undergoing a fundamental reevaluation. This review of the potential of low-resource agriculture, and options the United States might pursue to enhance this approach, was intended to aid in this reevaluation.  相似文献   

9.
The replacement theory of modern human origins stipulates that populations outside of Africa were replaced by a new African species of modern humans. Here we test the replacement theory in two peripheral areas far from Africa by examining the ancestry of early modern Australians and Central Europeans. Analysis of pairwise differences was used to determine if dual ancestry in local archaic populations and earlier modern populations from the Levant and/or Africa could be rejected. The data imply that both have a dual ancestry. The diversity of recent humans cannot result exclusively from a single Late Pleistocene dispersal.  相似文献   

10.
Traditional African American foods, also referred to as “soul food,” are often given a blanket label of “poor food choices.” The cultural value of these ethnic foods may be disregarded without sufficient study of their nutrient content. This study showed that of the various foods perceived as traditionally African American by the local sampled population, greens were the most often identified as such by 78% and the most frequently consumed (22%) by the subjects. 37% perceived chitterlings as a traditional food, yet only 30% consumed them, and only on an occasional basis. Okra, yams, and black-eyed peas had relatively high consumptions but were not often perceived as traditional African American foods. The latter may suggests a lack of historical food facts, relating to indigenous African foods or may indicate the mainstreaming of these foods. Cowpeas or black-eyed peas, okra, sesame seeds, and watermelon seeds were originally brought to North America from Africa. The literature contains scant information on this particular topic, which leaves unanswered: (1) the current consumption of traditional foods by African Americans, (2) certain availability of these foods; and (3) the positive contributions to the diet that these foods may contribute. The author recognizes that “African American” is the most appropriate and preferred term used widely today, to refer to African descendants in North America, however “Black” and “Black American” will be used interchangeably, to reflect consistency of literature cited herein. First, this article will define traditional African American foods and relate their historical significance. Secondly, it will present data on current food consumption from a sample population of African Americans surveyed in San Diego. Lastly, this article will explore possible applications of the research itself.  相似文献   

11.
为全面评价引进的欧洲、北美啤酒大麦种质在甘肃省的育种潜力,选取来自欧洲、北美的26份啤酒大麦及甘肃省自育的7份啤酒大麦种质为试验材料,采用随机区组设计,鉴定了33份材料的农艺、产量和品质性状.结果 表明,不同地区来源的参试品种间在农艺性状上具有显著差异,其中,欧洲啤酒大麦品种间差异最大,其次为北美啤酒大麦,甘肃啤酒大麦...  相似文献   

12.
Human genetic and phenotypic diversity declines with distance from Africa, as predicted by a serial founder effect in which successive population bottlenecks during range expansion progressively reduce diversity, underpinning support for an African origin of modern humans. Recent work suggests that a similar founder effect may operate on human culture and language. Here I show that the number of phonemes used in a global sample of 504 languages is also clinal and fits a serial founder-effect model of expansion from an inferred origin in Africa. This result, which is not explained by more recent demographic history, local language diversity, or statistical non-independence within language families, points to parallel mechanisms shaping genetic and linguistic diversity and supports an African origin of modern human languages.  相似文献   

13.
One of the largest earthquakes ever recorded in Africa (surface wave magnitude M(s) = 7.2) occurred about 50 kilometers east of the Upper River Nile on 20 May 1990. Four days later, two more large earthquakes (M(s) = 6.4 and 7.0) occurred about 50 kilometers to the northwest in the Nile Valley. In the following months, a further 60 events were recorded by seismic stations worldwide. The earthquakes are associated with two fault systems: one east of the Nile with azimuth southeast and one along the Nile Valley with azimuth north-northeast. The activity alternated between the two fault systems and indicates that the northern extremity of the western branch of the East African Rift System extends at least 350 kilometers north of Lake Albert.  相似文献   

14.
The origin of the Andaman "Negrito" and Nicobar "Mongoloid" populations has been ambiguous. Our analyses of complete mitochondrial DNA sequences from Onges and Great Andaman populations revealed two deeply branching clades that share their most recent common ancestor in founder haplogroup M, with lineages spread among India, Africa, East Asia, New Guinea, and Australia. This distribution suggests that these two clades have likely survived in genetic isolation since the initial settlement of the islands during an out-of-Africa migration by anatomically modern humans. In contrast, Nicobarese sequences illustrate a close genetic relationship with populations from Southeast Asia.  相似文献   

15.
Crop-livestock farms across Africa are highly variable due to in agroecological and socioeconomic factors, the latter shaping the demand and supply of livestock products. Crop-livestock farms in Africa in the 20-first century are very different from most mixed farms elsewhere in the world. African crop-livestock farms are smaller in size, have fewer livestock, lower productivity and less dependency on imported feed than farms in most countries of Europe, the Americas and the intensive agricultural systems of Asia. This paper discusses the role African crop-livestock farms have in the broader socio-agricultural economy, and how these are likely to change adapting to pressures brought on by the intensification of food systems. This intensification implies increasing land productivity (more food per hectare), often leading to more livestock heads per farm, producing fertilized feeds in croplands and importing feed supplements from the market. This discussion includes (1) the links between crop yields, soil fertility and crop-livestock integration, (2) the increasing demand for livestock products and the land resources required to meet to this demand, and (3) the opportunities to integrate broader societal goals into the development of crop-livestock farms. There is ample room for development of crop-livestock farms in Africa, and keeping integration as part of the development will help prevent many of the mistakes and environmental problems related to the intensification of livestock production observed elsewhere in the world. This development can integrate biodiversity, climate change adaptation and mitigation to the current goals of increasing productivity and food security. The inclusion of broader goals could help farmers access the level of finance required to implement changes.  相似文献   

16.
Africa, the second largest continent in the world, has achieved remarkable economic and political results through exploration and positive development. Ecological security comprehensively reflects the health and integrity of an ecosystem, and it is broadly defined as the security state of a complex artificial ecosystem composed of natural, economic and social factors. Ecological security determines the potential for sustainable development in Africa, especially with its rapidly developing economies. However, there is a lack of information on the ecological security state of the continent as a whole. In this study, we constructed an evaluation system based on a pressure-state-response model and evaluated the ecological security state of all 54 African countries. The results showed that, at the national level, the ecological security state of the countries in Africa differed, as did their spatial and temporal variations from 1995 to 2016. In general, African countries showed relatively good ecological security. The years 2007 and 2001 were the worst and best years, respectively, in terms of ecological security during the study period. At the regional level, North Africa and West Africa had the best and worst ecological security, respectively.  相似文献   

17.
Palanichamy MG  Agrawal S  Yao YG  Kong QP  Sun C  Khan F  Chaudhuri TK  Zhang YP 《Science (New York, N.Y.)》2006,311(5760):470; author reply 470
On the basis of mitochondrial DNA sequence analyses, Thangaraj et al. (Brevia, 13 May 2005, p. 996) proposed that Andaman islanders descended from the first humans to migrate out of Africa. We identified mitochondrial DNA from two northeast Indian Rajbanshi individuals that shares three specific mutations with the M31a lineage observed in the Great Andamanese, which suggests that the predecessor of haplogroup M31 originated on the Indian subcontinent.  相似文献   

18.
合作猪、迪庆藏猪和成华猪的血清运铁蛋白多型性   总被引:2,自引:1,他引:1  
采用水平板淀粉凝胶电泳法测定了55头合作猪、52头迪庆藏猪和40头成华猪的皿清运铁蛋白座位的多型性,将所测结果与其它39个亚欧非地方猪群体相比较发现,TfB基因在所有地方猪群体中都存在,TfA基因在中国地方猪群体中常见,TfC基因在亚洲地方猪群体中有从北到南逐渐增多的趋势。  相似文献   

19.
全面综述了槭菌刺孢(M.acerina)真菌的分布与危害、分类与形态、生理与生态、致病性与寄主范围、侵染机制与抗菌物质等方面的研究概况.槭菌刺孢是菌刺孢属(Mycocentrospora)真菌的模式种,也是我国真菌新记录种.主要分布于欧洲和北美洲,在低温高湿条件下引致多种蔬菜和观赏植物病害.我国以前无该种真菌的记载和研究,近年来发现该菌侵染药用植物细辛引致叶枯病,造成毁灭性损失.  相似文献   

20.
This report describes serologic evidence for a virus similar to that known as simian T-lymphotropic virus type III of African Green monkeys (STLV-IIIAGM) infecting apparently healthy people in Senegal, West Africa, and the isolation of virus from these individuals. Serum samples from selected healthy West African people showed unusual serologic profiles when tested with antigens of HTLV-III/LAV, the etiologic agent of AIDS, and of STLV-IIIAGM. The samples reacted strongly with all of the major viral antigens of STLV-IIIAGM but showed variable or no reactivity with the major viral antigens of HTLV-III/LAV by radioimmunoprecipitation and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. A new human T-lymphotropic virus (HTLV-IV) isolated from these people was grown in vitro and shown to have retroviral type particles, growth characteristics, and major viral proteins similar to those of the STLV-III and HTLV-III/LAV group of retroviruses. The gp120/160, gp32, p64, p55, p53, p24, and p15 proteins precipitated were the same size as and reactive with STLV-IIIAGM proteins. The serologic data suggest that this virus shares more common epitopes with STLV-IIIAGM than with the prototype HTLV-III/LAV that infects people in the United States and Europe. Further study of this virus and of the origin of the HTLV-III/LAV group of viruses may expand our understanding of the human AIDS virus.  相似文献   

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