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1.
There is now a substantial body of literature documenting the detectability of plants and animals under standard survey conditions. Despite the evidence that many flora and fauna species have detection probabilities of less than one, it is still the default assumption of most environmental impact assessment processes that if a species is present, it will be detected. Here we briefly review a number of existing studies that have estimated the survey effort necessary to detect animal species, based on what is known about their detection rates in standard surveys. We then propose a novel method, based on failure‐time analysis, for quantifying the detectability of and determining appropriate survey effort for plant species during flora surveys. We provide computer code for implementing the method in the Bayesian freeware WinBUGS. Methods for estimating detectability can be used to inform minimum survey requirements and have important applications in environmental impact assessment and monitoring.  相似文献   
2.
Experimental evidence on the determinants of prey vulnerability is scarce, especially for vertebrates in the field. Invasive species offer robust opportunities to explore prey vulnerability, because the intensity of predation on or by such animals has not been eroded by coevolution. Around waterbodies in tropical Australia, native meat ants (Iridomyrmex reburrus) consume many metamorph cane toads (Bufo marinus, an invasive anuran). We document the determinants of toad vulnerability, especially the roles of toad body size and ant density. Larger metamorphs were attacked sooner (because they attracted more ants), but escaped more often. Overall, smaller toads were more likely to be killed. Ant densities influenced toad responses, as well as attack rate and success. Data on the immediate outcomes of attacks underestimate mortality: more than 73% of apparent ‘escapees’ died within 24 h. Because mortality during this period was independent of toad size, predation was less size selective than suggested by immediate outcomes. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 99 , 738–751.  相似文献   
3.
The characteristics of a good psychiatrist practising in the UK health services have been described in policy but not in practice. We set out to determine what key characteristics are required for an individual to be identified as a good psychiatrist to become a member of the Royal College of Psychiatrists. A postal survey of all clinical tutors responsible for psychiatric training in the UK and Eire was carried out. These tutors are approved by the Royal College of Psychiatrists. 113 tutors responded (out of 163, 69.3% return). The most important identified characteristic was overall competency in diagnosis, management and investigations (98%) and the least desirable was ability to appraise staff (13%). With recent changes in training and assessment in the UK, further surveys of this kind are indicated to understand the trainers’ views, and should be extended also to trainees  相似文献   
4.
Protein patterns and synthetic profiles were examined during distal regeneration in Hydraoligactis . Electrophoretic and radioactive tracer analyses revealed qualitative changes in the general protein profile during regeneration, with a heightened period of protein synthesis between 27–30 hr of regeneration, immediately preceding emergence of the first pair of tentacles. Following this, an increase in collagen-rich mesogleal protein secretion was observed coincident with tentacle initiation. Inhibition of collagen secretion with the proline analog L-azetidine-2-carboxylic acid (LACA) inhibited tentacle formation, and resulted in the development of unique "hypostome buds" at the distal regeneration surface. At the cellular level LACA did not inhibit the nerve cell differentiation that normally precedes tentacle growth, although some predicted decline in cnidocyte production was noted. It is proposed that mesogleal collagen secretion and structural organization may play a major role in the mechanical aspects of Hydra tentacle morphogenesis.  相似文献   
5.
The genus Bellevalia is represented in Greece by eight taxa, three of which are endemic. Bellevalia brevipedicellata (2n = 8) and B. sitiaca (2n = 16) are restricted to the island of Kriti, while B. hyacinthoides (2n = 8, 12) is distributed in the Kiklades Islands, the central and southern mainland and the Ionian Islands. Four taxa, i.e. B. dubia subsp. boissieri (2n = 8), B. trifoliata (2n = 8), B. romana (2n = 8) and B. ciliata (2n = 8, 16) are Mediterranean elements. The presence of B. edirnensis (2n = 24) is reported as new for the Greek flora. New ploidy levels of three Bellevalia species (triplo‐, tetra‐ and hexaploids) are reported for the first time. The main morphological features, the chromosome numbers, the karyotype morphology, as well as the geographical distribution and further issues of taxonomy and conservation of all Bellevalia taxa in Greece are presented and discussed. © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 157 , 723–739.  相似文献   
6.
The Eurasian black vulture (Aegypius monachus) has experienced a severe decline during the last two centuries and is globally classified as near‐threatened. This has led to the extinction of many traditional breeding areas in Europe and resulted in the present patchy distribution (Iberian and Balkan peninsulas) in the Western Palearctic. In the present study, we describe the current genetic status of the European populations using both mitochondrial cytochrome b sequences and nuclear microsatellite markers, comparing with those found in Asia (Mongolia and Caucasus region). Although, mitochondrial (mt)DNA revealed a relatively low genetic variability (haplotype diversity), no evidence of genome‐wide genetic erosion exists because nuclear diversity exhibits normal levels and strong differentiation. A highly philopatric dispersal behaviour must be invoked to explain the existence of a clear pattern that revealed by the phylogeographic analysis, which indicates a sharp East–West clinal distribution and an allopatric differentiation. The distribution of mtDNA haplotypes one in the Iberian population and two in Balkan population and the significance divergence at nuclear loci fulfill the definitions of those populations as evolutionary significant units. We discuss how management strategies should aim at the maintenance (or increase) of current genetic variability levels, suggesting that independent conservation plans are urgently required to protect these two breeding European populations from extinction. © 2008 The Linnean Society of London, Biological Journal of the Linnean Society, 2008, 95 , 859–872.  相似文献   
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8.
The prevalence of genetic variants associated to cutaneous melanoma (CM) has never been determined within Cypriot melanomas. This study evaluates the frequency of variants in cyclin-dependent kinase inhibitor 2A (CDKN2A) and melanocortin-1 receptor (MC1R) in 32 patients diagnosed with CM. Other characteristics and risk factors were also assessed. CDKN2A p.Ala148Thr was detected in three of 32 patients, while the control group revealed no variations within CDKN2A. MC1R screening in 32 patients revealed the following variations: p.Val60Leu in 11 patients, p.Arg142His in four patients, p.Thr314Thr in one patient, p.Arg160Trp in one patient, p.Val92Met/p.Thr314Thr in one patient and p.Val92Met/p.Arg142His/p.Thr314Thr in one patient. The control group revealed only p.Val60Leu (in 10 of 45 individuals), which is frequently found in general populations. Two unrelated patients carried CDKN2A p.Ala148Thr in combination with MC1R p.Arg142His, suggesting digenic inheritance that may provide evidence of different gene variants acting synergistically to contribute for CM development. This study confirms the presence of CDKN2A and MC1R variants among Cypriot melanomas and supports existing evidence of a role for these variants in susceptibility to melanoma.  相似文献   
9.
For the past 25 years we have used a comparative strategy designedto identify anddescribe the endocrine parameters of the oviparous-vivparoustransition and subsequent gradual reduction in hepatic yolkprotein precursor (vitellogenin) synthesis associated with placentalviviparity. Our approach has been to study vertebrate groupsin which both oviparous and viviparous modes are common (reptiles,elasmobranchs). We have provided evidence for the control offollicular (granulosa/theca) and luteal steroidogenesis, andthe cellular basis of gonadal steroid hormone action on thekey target tissues (oviduct, liver). Our results, some of whichare summarized below, have led us to suggest that ovarian progesterone(follicular or luteal in origin) has a dual role in the evolutionof viviparity: 1. To inhibit myometrial contractions, thus providinga primary condition for egg retention and viviparity. 2. Toinhibit estrogen-induced hepatic vitellogenin synthesis as partof both normal oviparous cycles and as a concomitant of placentalevolution.  相似文献   
10.
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