共查询到20条相似文献,搜索用时 31 毫秒
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J. Mario Vargas Jesus Duarte Miguel Angel Farfán Rafael Villafuerte John E. Fa 《The Journal of wildlife management》2012,76(4):714-720
The red-legged partridge (Alectoris rufa) is abundant in a number of regions in Spain and one of the most commonly hunted small game species in the country. Partridge hunting generates substantial income in rural areas where agriculture is less profitable. A traditional hunting method, reclamo hunting, is currently under revision by the European Commission's (EC) Birds Directive because hunting may fall within the reproduction period of the species. So far, only limited data on the reproductive phenology of the species exist to inform a policy change. In this study, we present reproduction data for red-legged partridges from 9 hunting estates in Andalusia during 1 year, and over 3 consecutive seasons from a control estate. We used direct nest and partridge chick covey observations to estimate 165 egg-laying dates. We found significant differences between sites related to altitude during reproduction periods. Using our pooled data, we showed that reproduction occurred between the last 10 days in January and the middle of February; beyond 31 January we observed an exponential increase in birds reproduction. According to these data and current EC legislation, reclamo hunting should not extend beyond 31 January. © 2012 The Wildlife Society. 相似文献
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Colony size can be considered the analogue of the body size of a superorganism. Just as body size is important to the physiology of an individual animal, colony size correlates with the life-history and ecology of social insects. Although nest excavation and counting all individuals is the most accurate method for estimating colony size (or nest size), it has the major drawback of being destructive. Alternatively, mark–release–recapture (MRR) can be used repeatedly to measure the size of the same colony or nest. We compared the accuracy and feasibility of four MRR methods and a Mound-Volume method with complete counts from nest excavation for estimating the nest size of F. lugubris, a mound-building wood ant of the Formica rufa group, during the early spring in Scotland. We found that our After-Disturbing method, in which we performed marking and recapturing after gentle disturbance to the top of nest mound, has the best balance between accuracy, non-destructiveness, and time required. We also found that mound volume can be an index of ant nest size under certain conditions. Both non-destructive methods can be used on the same colony or nest repeatedly to monitor nest dynamics. 相似文献
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G Libertini 《Biochemistry. Biokhimii?a》2012,77(7):795-798
The classical approach of evolutionism is based on the concept of the survival of the fittest individuals. More and more data
indicate that natural selection often acts with supra-individual mechanisms favoring genes and actions harmful for the individual.
The most striking type of cases is when an individual kills himself or his offspring by actions genetically determined or
favored. The neologism “phenoptosis” describes these events and implicates that they are not evolutionary anomalies but physiological
phenomena determined by natural selection. The most important and familiar kind of phenoptosis, the “slow phenoptosis” or
aging, which is currently considered an inevitable and scarcely changeable event, is transformed by this different interpretation
into a function, in principle modifiable and manageable. Perhaps, the neologism “phenoptosis” will represent, together with
the term supra-individual selection, the mark of a vital enrichment of evolutionism, conceived in broader terms of which the
individual selection is just a particular case, and will be referred to as the brand and the standard for the start of a new
era. 相似文献
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Achiraman S Archunan G Abirami B Kokilavani P Suriyakalaa U SankarGanesh D Kamalakkannan S Kannan S Habara Y Sankar R 《Theriogenology》2011,76(9):1676-1683
Squalene in the rat clitoral gland is reported to be semi-volatile and may serve as a chemo-signal. The objective was to determine squalene concentrations in the clitoral gland throughout the reproductive cycle. Clitoral glands were extracted with dichloromethane; 23 compounds were identified with Gas Chromatography linked Mass Spectrometry (GC-MS). Since squalene concentrations were significantly higher during proestrus and estrus, and remarkably reduced during metestrus and diestrus, we inferred that it could be an ovulation-indicating chemosignal in the female rat, acting as a scent mark for the male. This hypothesis was tested by investigating its efficacy to attract males, including studying the role of the olfactory-vomeronasal system of the male in perceiving squalene. For detection of squalene, males used their conventional olfactory system when at a distance from the female, whereas the vomeronasal organ was used when they were in close proximity to the female. We concluded that squalene was a female-specific chemosignal that attracted males, and furthermore, that the olfactory-vomeronasal system had an important role in the perception of squalene. 相似文献
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The survival for adult loggerhead sea turtles from a saturation tagging study on Bald Head Island, NC, USA, was estimated
using a multistate model with unobservable states to relax assumptions that are violated when survival is estimated from multistate
models and produce more accurate estimates of survival, recapture, and breeding transition probabilities. The influence of
time, trap dependence, and low site fidelity to the study nesting beach on survival and recapture were examined. The best
model given the data included an imprecise site-fidelity effect on survival, constrained the reproductive cycle to 4 years,
and contained a time effect on recapture rates. The estimate of annual survival for adult females was of 0.85, producing the
highest estimate in the literature for loggerhead sea turtles. Multistate models should be applied to other nesting beach
data for sea turtles to improve survival estimates and in turn the ability to model and manage populations. 相似文献
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Magnetic resonance imaging is a diagnostic technique widely used in medicine and showing a growing impact in cardiology. Biological effects associated to magnetic resonance electromagnetic fields have received far little attention, but it cannot be ruled out that these fields can alter DNA structure. The present study aimed at to identify possible DNA damage induced by magnetic resonance scan in humans. Lymphocyte cultures from healthy subjects had been exposed into magnetic resonance device for different times and under different variable magnetic exposure in order to build dose-effect curves, using micronuclei induction as biological marker. Replicate cultures were also left for 24h at room temperature before stimulation, to verify possible damage recovery. Furthermore, micronuclei induction and recovery up to 120h have been also evaluated in circulating lymphocytes of individuals after cardiac scan. A dose-dependent increase of micronuclei frequency was observed in vitro. However after 24h, the frequency returns to control value when the exposure is within diagnostic dosage. After in vivo scan, a significant increase in micronuclei is found till 24h, after the frequencies slowly return to control value. 相似文献
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Roodman GD 《Nature medicine》2012,18(4):491-492
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Venkitaraman AR 《Cell》2011,145(3):337-338
Genome instability occurs early in the development of most cancers. Bester et?al. now provide evidence that oncogenic signals trigger cell division without coordinate nucleotide synthesis, engendering aberrant DNA replication and damage that could promote carcinogenesis. A mismatch between proliferation and metabolite production may characterize oncogenic cell cycles. 相似文献
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Vanessa Kloke Rebecca S. Schreiber Carina Bodden Julian M?llers Hanna Ruhmann Sylvia Kaiser Klaus-Peter Lesch Norbert Sachser Lars Lewejohann 《PloS one》2014,9(8)
Cognitive bias, the altered information processing resulting from the background emotional state of an individual, has been suggested as a promising new indicator of animal emotion. Comparable to anxious or depressed humans, animals in a putatively negative emotional state are more likely to judge an ambiguous stimulus as if it predicts a negative event, than those in positive states. The present study aimed to establish a cognitive bias test for mice based on a spatial judgment task and to apply it in a pilot study to serotonin transporter (5-HTT) knockout mice, a well-established mouse model for the study of anxiety- and depression-related behavior. In a first step, we validated that our setup can assess different expectations about the outcome of an ambiguous stimulus: mice having learned to expect something positive within a maze differed significantly in their behavior towards an unfamiliar location than animals having learned to expect something negative. In a second step, the use of spatial location as a discriminatory stimulus was confirmed by showing that mice interpret an ambiguous stimulus depending on its spatial location, with a position exactly midway between a positive and a negative reference point provoking the highest level of ambiguity. Finally, the anxiety- and depression-like phenotype of the 5-HTT knockout mouse model manifested - comparable to human conditions - in a trend for a negatively distorted interpretation of ambiguous information, albeit this effect was not statistically significant. The results suggest that the present cognitive bias test provides a useful basis to study the emotional state in mice, which may not only increase the translational value of animal models in the study of human affective disorders, but which is also a central objective of animal welfare research. 相似文献
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Age estimation of unknown skeletal remains is very important in forensic medicine. Morphologic methods are fast and easy to use for purpose of age determination. The sternal ends of the ribs are a reliable method of age estimation from late adolescence to old age. Iscan et al developed a phase analysis method for the right 4th rib that was sex and race specific. The purpose of this study is to determine the accuracy of the standards of age estimation from the right 4th and other rib using the phase analysis for the Turkish population. The sample consisted of right and left 3rd, 4th and 5th ribs from 34 Turkish women and 76 men. There were statistically significant variations found on the right 5th, left 3rd, 4th, and 5th ribs according to these standards in men for phases 5, 6, and 7. For women, all the right and left ribs included in this study were in concordance with right 4th rib standards in all phases. 相似文献
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Malnutrition, poor health, hunger, and even starvation are still the world's greatest challenges. Malnutrition is defined as deficiency of nutrition due to not ingesting the proper amounts of nutrients by simply not eating enough food and/or by consuming nutrient-poor food in respect to the daily nutritional requirements. Moreover, malnutrition and disease are closely associated and incidences of such diet-related diseases increase particularly in low- and middle-income states. While foods of animal origin are often unaffordable to low-income families, various neglected crops can offer an alternative source of micronutrients, vitamins, as well as health-promoting secondary plant metabolites. Therefore, agricultural and horticultural research should develop strategies not only to produce more food, but also to improve access to more nutritious food. In this context, one promising approach is to promote biodiversity in the dietary pattern of low-income people by getting access to nutritional as well as affordable food and providing recommendations for food selection and preparation. Worldwide, a multitude of various plant species are assigned to be consumed as grains, vegetables, and fruits, but only a limited number of these species are used as commercial cash crops. Consequently, numerous neglected and underutilized species offer the potential to diversify not only the human diet, but also increase food production levels, and, thus, enable more sustainable and resilient agro- and horti-food systems. To exploit the potential of neglected plant (NP) species, coordinated approaches on the local, regional, and international level have to be integrated that consequently demand the involvement of numerous multi-stakeholders. Thus, the objective of the present review is to evaluate whether NP species are important as “Future Food” for improving the nutritional status of humans as well as increasing resilience of agro- and horti-food systems. 相似文献
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Czodrowski P 《Bioorganic & medicinal chemistry》2012,20(18):5453-5460
It is tempting to use standard protonation states for the analysis of protein-ligand interactions. Two different pK(a) calculation methods, PROPKA (protein pK(a)) and MCCE (multi conformation continuum electrostatics), were applied to challenge this convenient behavior. As data basis, we selected five recently approved drugs for which structural information of the protein-drug complex is available. We analyzed the pK(a) calculations in terms of a measure termed BIPS (binary protonation states) recently introduced by us. Both methods agree in detecting the majority of the sites with atypical BIPS values. However, when using only one method, some of the atypcial BIPS value would have been missed. Therefore, we recommend using both methods to set such an interpretation on a solid basis. 相似文献
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'Statins' are 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors - oral cholesterol-lowering drugs that are used to treat hypercholesterolaemia. It is widely accepted that statins have anti-inflammatory effects that are independent of their ability to lower cholesterol. Animal studies and observational clinical studies have indicated that statins might also be effective in treating certain neurological diseases - in particular, multiple sclerosis, Alzheimer's disease and ischaemic stroke. At present, however, results from ongoing prospective, randomized clinical trials are not available. 相似文献
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Matthew Desmond 《Ethnic and racial studies》2015,38(8):1258-1263
This commentary articulates three perspectives on race in America: economic determinism, institutionalism and a field-theoretic approach. It argues that William Julius Wilson's masterwork, The Declining Significance of Race, was informed by the first and anticipated the latter two. Wilson's most profound and enduring legacy is his unwavering concern for the dispossessed. 相似文献