منابع مشابه
Protected Areas in Tropical Africa: Assessing Threats and Conservation Activities
Numerous protected areas (PAs) have been created in Africa to safeguard wildlife and other natural resources. However, significant threats from anthropogenic activities and decline of wildlife populations persist, while conservation efforts in most PAs are still minimal. We assessed the impact level of the most common threats to wildlife within PAs in tropical Africa and the relationship of con...
متن کاملCardiomegaly in tropical Africa.
The term "cardiomegaly" is found in 5-7% of chest X-ray film evaluations in tropical Africa. However, "cardiomegaly" is a descriptive term, devoid of any aetiological meaning. Therefore, providing information about the aetiological factors leading to heart enlargement in a group of Africans (Nigerians) was the purpose of this study. In the years 2002-2011, 170 subjects (aged 17-80 years, mean a...
متن کاملVenereal syphilis in tropical Africa.
A steady decline in the incidence of positive results to the Kahn test is reported in Malawian patients during the period 1968-75. Other studies have shown that the incidence of early and late syphilis in sub-Saharan Africa has dropped considerably over the past few decades. The number of reported cases of early syphilis in certain urban areas, however, appears to be high. It is suggested that ...
متن کاملBiodiversity conservation in tropical agroecosystems: a new conservation paradigm.
It is almost certainly the case that many populations have always existed as metapopulations, leading to the conclusion that local extinctions are common and normally balanced by migrations. This conclusion has major consequences for biodiversity conservation in fragmented tropical forests and the agricultural matrices in which they are embedded. Here we make the argument that the conservation ...
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ژورنال
عنوان ژورنال: Nature
سال: 1938
ISSN: 0028-0836,1476-4687
DOI: 10.1038/141268a0