Baboons (Papio cynocephalus) imported from Ethiopia were screened for antibodies to various primate retroviruses by immunoblotting. Antibodies that cross-reacted with SIV/Mne or with type D viral antigens were detected in approximately one-third of these animals. In addition, 20% of these baboons had antibodies that cross-reacted with HTLV-I viral antigens. These data suggest that wild-caught baboons are infected with retroviruses only partially related to known primate viral isolates. 相似文献
Macroinvertebrate communities sampled by a corer, plankton net and sweep net from five wetlands on the Swan Coastal Plain
were compared. The composition of the fauna collected in sweeps and tows was generally similar and differed from that collected
in the cores. Cores caught fewer species than tows and sweeps at all wetlands and did not capture fast swimming hemipterans
or less abundant taxa. The highest species richness was recorded in sweep samples in four out of the five wetlands. Classification
(TWIN-SPAN) and ordination (SSH) of the samples collected in sweeps and tows gave good separation of the wetlands, whereas
classification of core samples did not. Coring appeared to be the least suitable sampling method for describing the major
components of the macroinvertebrate communities of these wetlands. Plankton tows were useful if the time available for sorting
was limited as these samples were free of sediments and generally gave similar results to those obtained with sweeps. Sweeps
appeared to be the most useful method for a large classification study as they collected more species and resulted in the
best discrimination amongst wetlands. 相似文献
1. 1. The writers present the general theory of evaluation that is being developed by their group.
2. 2. The evaluation of a human environment is a complex mental process.
3. 3. In an effort to express numerically the quality of an environment, one tends to oversimplify the complex aspects of it and the entailing problems in relation to its inhabitants.
4. 4. In this paper, some examples are taken in the evaluation of thermal environments, wherein much has been said and done in setting up numerical scales to express human comfort, and yet neither clear-cut explanations nor convincing logic seem to exist to terminate the argument over the widely scattered and sometimes seemingly contradicting experimental data.
5. 5. The writers suggest that many of the reasons for this confusion may be traced back to the oversimplified notion of evaluation.
6. 6. It is shown that there are various possibilities when looking at the scales of evaluation.
7. 7.|The nominal scale, least studied of all the four traditional scales, may be given a prominent place in evaluating a thermal environment. The pseudo-interval order scale is another example.
Author Keywords: evaluation; scales; thermal environment; classification; pseudo-interval order 相似文献
The world's primates have been severely impacted in diverse and profound ways by anthropogenic pressures. Here, we evaluate the impact of various infrastructures and human-modified landscapes on spatial patterns of primate species richness, at both global and regional scales. We overlaid the International Union for the Conservation of Nature (IUCN) range maps of 520 primate species and applied a global 100 km2 grid. We used structural equation modeling and simultaneous autoregressive models to evaluate direct and indirect effects of six human-altered landscapes variables (i.e., human footprint [HFP], croplands [CROP], road density [ROAD], pasture lands [PAST], protected areas [PAs], and Indigenous Peoples' lands [IPLs]) on global primate species richness, threatened and non-threatened species, as well as on species with decreasing and non-decreasing populations. Two-thirds of all primate species are classified as threatened (i.e., Critically Endangered, Endangered, and Vulnerable), with ~86% experiencing population declines, and ~84% impacted by domestic or international trade. We found that the expansion of PAST, HFP, CROP, and road infrastructure had the most direct negative effects on primate richness. In contrast, forested habitat within IPLs and PAs was positively associated in safeguarding primate species diversity globally, with an even stronger effect at the regional level. Our results show that IPLs and PAs play a critical role in primate species conservation, helping to prevent their extinction; in contrast, HFP growth and expansion has a dramatically negative effect on primate species worldwide. Our findings support predictions that the continued negative impact of anthropogenic pressures on natural habitats may lead to a significant decline in global primate species richness, and likely, species extirpations. We advocate for stronger national and international policy frameworks promoting alternative/sustainable livelihoods and reducing persistent anthropogenic pressures to help mitigate the extinction risk of the world's primate species. 相似文献
ABSTRACT. The recently established protozoan phylum Opalozoa Cavalier-Smith 1991 includes all those zooflagellates with tubular mitochondrial cristae that never have cortical alveoli or rigid tubular ciliary hairs (retronemes), and also the opalinids, proteomyxids sensu stricto, and plasmodiophorids. Opalozoa totally lack plastids but usually (though not invariably) have peroxisomes. They always have well-developed Golgi dictyosomes. The trophic phase is a unicellular ciliated phagotroph except in the only intracellular parasites, the plasmodiophorids, where it is a non-phagotrophic and non-ciliated microplasmodium, and in the proteomyxids where it is an amoeboflagellate (which may sometimes be nonciliated) or a multicellular meroplasmodium. Unlike the phagotrophic Mycetozoa, opalozoans do not form aerial fruiting bodies, but encystation is common. The first detailed classification of the phylum is presented here. It is divided into four subphyla (three new), eight classes (four new, one emended), three subclasses (all new), three superorders (all new) and 22 orders of which 12 are new and one is emended. Diagnoses of these taxa are given, as well as lists of the 31 families (11 new) and 62 genera included within them. Opalozoa, which include Cercomonas and Heterornita , the commonest soil flagellates, are ecologically and evolutionarily important. 相似文献
The relationships within theAsteraceae-Asteroideae are scrutinized by means of cladistic analyses of morphological and chemical data. New data are presented, and novel interpretations of features previously used in cladistic analyses are made. Examples are insertion of anther filaments in the corolla, and morphology of disc floret styles, respectively. The results include a polyphyletic or paraphyleticInuleae s. l., and a paraphyleticHeliantheae s.l. in which theEupatorieae constantly form a subclade. Comparisons are made with previous cladistic analyses of morphological data, and those acquired from molecular data. Speculations about the evolution of certain organs are presented. 相似文献