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131.
132.
133.
Goldizen et al. (1988) reported that wild saddle-back tamarins (Saguinus fuscicollis, Callitrichidae) show birth seasonality that is correlated with food supply and body weight. They suggested a sequence of
ultimate causality in which shortage of food leads to reduced body weight which leads to timing of weaning and lactation when
resources are more abundant. Cotton-top tamarins in captivity show birth seasonality despite constant food supply and body
weight. Although natural availability of fruit and insects (which are key foods for tamarins) is related to rainfall, birth
seasonality and body weight in captive cotton-top tamarins are unrelated to rainfall. The most likely proximate mechanism
for seasonality of births in tamarins is photo-period, given existing data on populations living in natural and artificial
lighting. 相似文献
134.
Linda F. Marchant William C. McGrew Irenus Eibl-Eibesfeldt 《Ethology : formerly Zeitschrift fur Tierpsychologie》1995,101(3):239-258
Right-handedness in Homo sapiens is claimed to be qualitatively different from that of other primates, at species level, and to be universal across all cultures. Ethnographic indicators are sparse, however, being mostly indirect rather than direct observations of selected motor patterns. Ethological study of hand use, i.e. observation of a wide range of everyday behavioural patterns performed spontaneously, is missing. We coded such manual activity from cinematic archives of three traditional societies: G/wi San of Botswana, Himba of Namibia and Yanomamö of Venezuela. Results showed a consistent but weak right-hand dominance across these three preliterate cultures. Most individuals showed mixed-, rather than right-handedness, irrespective of whether or not object manipulation was involved. The notable exception was tool use, which was markedly right-handed, and only precision-gripping tool use was normally performed exclusively with the right hand. Most questionnaires that measure handedness focus on precision tool use (and so are likely to be biased accordingly) rather than on more comprehensive ethological measures that include non-object-manipulatory, self-directed and socially communicative patterns of behaviour. 相似文献
135.
136.
Lathe WC rd; Burke WD; Eickbush DG; Eickbush TH 《Molecular biology and evolution》1995,12(6):1094-1105
R1 is a non-long terminal repeat (non-LTR) retrotransposable element that
inserts into a specific sequence of insect 28S ribosomal RNA genes. We have
previously shown that this element has been maintained through vertical
transmission in the melanogaster species subgroup of Drosophila. To address
whether R1 elements have been vertically transmitted for longer periods of
evolutionary time, the analysis has been extended to 11 other species from
four species groups of the genus Drosophila (melanogaster, obscura,
testecea, and repleta). All sequenced elements appeared functional on the
basis of the preservation of their open-reading frames and consistently
higher rate of substitution at synonymous sites relative to replacement
sites. The phylogenetic relationships of the R1 elements from all species
analyzed were congruent with the species phylogenies, suggesting that the
R1 elements have been vertically transmitted since the inception of the
Drosophila genus, an estimated 50-70 Mya. The stable maintenance of R1
through the germ line appears to be the major mechanism for the widespread
distribution of these elements in Drosophila. In two species, D.
neotestecea of the testecea group and D. takahashii of the melanogaster
group, a second family of R1 elements was also present that differed in
sequence by 46% and 31%, respectively, from the family that was congruent
with the species phylogeny. These second families may represent occasional
horizontal transfers or, alternatively, they could reflect the ability of
R1 elements to diverge into new families within a species and evolve
independently.
相似文献
137.
Five types of introductory university textbooks (N=37) were analyzed for references and citations pertaining to research on
wild chimpanzees. Jane Goodall's publications were cited about three times as often as the publications from field sites other
than Gombe and approximately five times more often than other Gombe researchers. Biological anthropology textbooks cited Goodall's
work most often, followed by textbooks in general anthropology and cultural anthropology. Psychology and biology textbooks
cited Goodall least often. Goodall's most comprehensive work, The Chimpanzees of Gombe: Patterns of Behavior (1986), was the
most often cited publication about Gombe's apes, and tool-use was the most cited topic. The number of citations to wild chimpanzees
tripled from publications in the 1960s to those in the 1980s, suggesting a growing recognition of primatology in the teaching
of science. 相似文献
138.
A 4-year study of the ecology and ethology of wild chimpanzees (Pan troglodytes verus)was carried out in far western Africa. Contacts with chimpanzees and the locations of their nests were noted to determine
which types of habitat were most used and to estimate the density of the population and the size of its home range. The results
show that this community has one of the lowest densities and largest home ranges of all populations of chimpanzees studied
so far. As such, it may provide a useful model for the reconstruction of hominid evolution in the Plio-Pleistocene. 相似文献
139.
Destruction of the CDC28/CLB mitotic kinase is not required for the metaphase to anaphase transition in budding yeast. 总被引:55,自引:19,他引:36
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It is widely assumed that degradation of mitotic cyclins causes a decrease in mitotic cdc2/CDC28 kinase activity and thereby triggers the metaphase to anaphase transition. Two observations made on the budding yeast Saccharomyces cerevisiae are inconsistent with this scenario: (i) anaphase occurs in the presence of high levels of kinase in cdc15 mutants and (ii) overproduction of a B-type mitotic cyclin causes arrest not in metaphase as previously reported but in telophase. Kinase destruction is therefore implicated in the exit from mitosis rather than the entry into anaphase. The behaviour of esp1 mutants shows in addition that kinase destruction can occur in the absence of anaphase completion. The execution of anaphase and the destruction of CDC28 kinase activity therefore appear to take place independently of one another. 相似文献
140.
C E Tutin M Fernandez M E Rogers E A Williamson W C McGrew 《Philosophical transactions of the Royal Society of London. Series B, Biological sciences》1991,334(1270):179-85; discussion 185-6
Comparison of the diets of sympatric gorillas and chimpanzees allows an analysis of niche separation between these two closely related species. Qualitatively, their diets are similar, being dominated by an equally diverse array of fruit species complemented with vegetative plant parts, seeds and insects. Gorillas eat more vegetative plant parts than do chimpanzees, but niche separation is most obvious in periods of fruit scarcity when the two species show different strategies that reduce competition for food. Their abilities to overcome mechanical and physical plant defences appear to differ, as gorillas are able to subsist entirely on abundant vegetative foods. Chimpanzees show social adjustment, foraging alone or in small groups, to reduce intra-specific competition for scarce fruit resources. Thus it seems that subtle physiological differences have far-reaching repercussions, defining potential evolutionary pathways for social organization and allowing sufficient niche separation between species. 相似文献