Anopheles leucosphyrus, an important vector of human malaria in Sarawak, Borneo, was shown to be infected with Plasmodium inui in Malaya by the inoculation of sporozoites into an uninfected rhesus monkey. The mosquito was caught while biting a man, thus demonstrating that it would be possible for a monkey infection to be transmitted to man in nature.
Insufficient use has been made of ecological data concerning potential hosts in studies to determine the life cycles of zoonotic parasites and pathogens. Factors such as the geographical distribution of hosts, the altitudes at which they live, their affinities for specific habitats, their vertical distribution within the habitat, and the periodicity of their activities have bearing on the hosts' predisposition to involvement in disease cycles. Diets and feeding habits may determine the likelihood of acquiring infection. Reproductive characteristics determine whether a species is suitable as a reservoir or as an amplifying host. Behavioral factors, such as selection of a particular kind of nest site, may also predispose the involvement of the host with parasites and pathogens. Behavior patterns may determine the maximum population densities of hosts. Estimates of population sizes, of relative abundances of species, and of the involvement of species in disease cycles may be strongly influenced by the collecting and sampling methods that are used and also by the behavioral response of the mammals toward collecting devices, such as traps.
The sensitivity of tropical forest carbon to climate is a key uncertainty in predicting global climate change. Although short-term drying and warming are known to affect forests, it is unknown if such effects translate into long-term responses. Here, we analyze 590 permanent plots measured across the tropics to derive the equilibrium climate controls on forest carbon. Maximum temperature is the most important predictor of aboveground biomass (-9.1 megagrams of carbon per hectare per degree Celsius), primarily by reducing woody productivity, and has a greater impact per °C in the hottest forests (>32.2°C). Our results nevertheless reveal greater thermal resilience than observations of short-term variation imply. To realize the long-term climate adaptation potential of tropical forests requires both protecting them and stabilizing Earth's climate.
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.
Australian Academy of Sciences, Royal Flemish Academy of Belgium for Sciences and the Arts, Brazilian Academy of Sciences, Royal Society of Canada, Caribbean Academy of Sciences, Chinese Academy of Sciences, et al.
The Physics Interviewing Project assists graduate physics departments in evaluating foreign applicants. Supported by some 20 universities, two interviewers, both working scientists, travel abroad and interview students individually for about 1 hour each. Prospective teaching assistants are rated on physics knowledge, problem-solving ability, and English language proficiency. Ratings on all interviewees are sent to all supporting schools and other schools as requested. The Project aids able students from countries that have no physics Ph.D. programs (Indonesia, Malaysia, Thailand) to obtain assistantships and Ph.D.'s abroad, assists in the technological development of those countries, and helps U.S. schools in selecting the most promising foreign candidates. A similar program should be beneficial in other sciences.