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991.
Edward?A.?RoualdesEmail authorView authors OrcID profile
return OK on get Simon?J.?Bonner Thomas?D.?Whitney James?D.?Harwood 《Environmental and Ecological Statistics》2016,23(2):317-336
The literature on modelling a predator’s prey selection describes many intuitive indices, few of which have both reasonable statistical justification and tractable asymptotic properties. Here, we provide a simple model that meets both of these criteria, while extending previous work to include an array of data from multiple species and time points. Further, we apply the expectation–maximisation algorithm to compute estimates if exact counts of the number of prey species eaten in a particular time period are not observed. We conduct a simulation study to demonstrate the accuracy of our method, and illustrate the utility of the approach for field analysis of predation using a real data set, collected on wolf spiders using molecular gut-content analysis. 相似文献
992.
本文集中在横向分析近期波兰儿童铅暴露和铅暴露增加背后的社会经济因素。在上西里西亚工业区,铅是分布最广泛的有毒重金属之一。儿童血铅水平升高关系儿童幸福,不断引起严重关切。本研究涉及在1999 - 2013年间,上西里西亚地区3岁到18岁的4 882名儿童。记录了每一个孩子血液中铅的浓度。孩子的父母被要求回答关于儿童接触铅的环境和家庭社会经济条件的问卷调查。铅暴露增加的因素包括:父母受教育程度较低,父母失业、父母的职业铅暴,家庭的贫穷社会经济地位,在家吸烟,生活在建筑物底层,食用本地种植的蔬菜和水果,在污染环境中长期进行户外活动和男性性别。铅的环境暴露仍然是导致上西里西亚地区儿童慢性铅中毒的主要因素。与儿童血铅浓度关系最大的社会经济因素是儿童父母的低教育水平。
精选自Wojciech Pelc, Natalia Pawlas, Micha? Dobrakowski, S?awomir Kasperczyk. Environmental and socioeconomic factors contributing to elevated blood lead levels in children from industrial area of Upper Silesia. Environmental Toxicology and Chemistry: Volume 35, Issue 10, pages 2597–2603, October 2016.
DOI: 10.1002/etc.3429
详情请见http://onlinelibrary.wiley.com/doi/10.1002/etc.3429/full 相似文献
993.
Jacquelin DeFaveri Takahito Shikano Nurul Izza Ab Ghani Juha Meril? 《Marine Biology》2012,159(8):1659-1672
Detailed multispecies studies on the patterns of genetic variability and differentiation in marine environments are still rare. Using mitochondrial and nuclear genetic markers, we compared genetic variability and population structuring of threespine (Gasterosteus aculeatus) and ninespine (Pungitius pungitius) sticklebacks from the same eleven marine and six freshwater locations within the Baltic Sea basin. Analyses of both marker types revealed a significantly lower degree of genetic structuring in both marine and freshwater populations of threespine than those ninespine sticklebacks. Isolation-by-distance (IBD) was detected across the marine populations in both species, suggesting spatially limited gene flow. However, the levels of genetic diversity and differentiation across the localities were uncorrelated between the two species in both marine and freshwater environments. Accordingly, estimates of effective population sizes were larger and migration rates were higher for three- than for ninespine sticklebacks. Hence, ninespine stickleback populations from the Baltic Sea basin appear to be subject to stronger genetic drift than sympatric threespine sticklebacks, and the proximate reason for this difference is likely to be found from autecological differences between the two species. In accordance with the earlier studies, genetic variability was higher and the degree of genetic differentiation was lower in marine than in freshwater populations in both species. 相似文献
994.
Aurélie Pinto Rodrigues Patrícia Correia Oliveira Lúcia Guilhermino Laura Guimar?es 《Marine Biology》2012,159(9):2061-2074
This study investigated the effects of salinity on biomarkers of oxidative stress, energy metabolism, and neurotransmission of Carcinus maenas from an estuary low impacted by pollution and from an estuary under chemical stress in the NW Iberian Peninsula. Crabs were collected in the field and, following an acclimation period, they were exposed for 7 days to five salinity levels ranging from 4 to 45 psu. At the end of the exposure period, stress biomarkers were determined in samples of muscle and digestive gland. The biomarkers assessed in the muscle were the activities of the enzymes cholinesterases (ChE), of which acetylcholinesterase is involved in neurotransmission, and lactate dehydrogenase (LDH) and isocitrate dehydrogenase (IDH) that are involved in energy metabolism. The biomarkers assessed in the digestive gland were (1) the activities of the enzymes glutathione S-transferases (GST), glutathione reductase (GR), and glutathione peroxidase (GPx), involved in phase II biotransformation and the anti-oxidant defence system; (2) the levels of total glutathiones (TG), also belonging to the anti-oxidant system; and (3) the levels of lipid peroxidation as a measure of oxidative damage. The results showed a significant influence of salinity on neurotransmission, energy metabolism, anti-oxidant status, and oxidative damage of C. maenas. For some biomarkers, this influence was dependent on whether the crabs were collected at the low-polluted estuary or at the contaminated estuary. In particular, crabs collected at the low-polluted estuary showed altered neurotransmission and anti-oxidant defences (GR). Crabs collected at the impacted estuary showed alterations in neurotransmission, energy metabolism (IDH and LDH), biotransformation, and anti-oxidant defences (GST, GR, GPx, and TG), as well as in oxidative damage, indicating that salinity change superimposes higher stress on these organisms. For ChE, IDH, and TG, altered responses were induced by both hypo- and hypersalinity. 相似文献
995.
Simona?Kralj-Fi?erEmail author Jutta?M.?Schneider ?iva?Justinek Sabina?Kalin Matja??Gregori? Stano?Pekár Matja??Kuntner 《Behavioral ecology and sociobiology》2012,66(1):145-151
Sexual cannibalism particularly before mating is costly for the male victim but also for the female aggressor if she risks
remaining unmated. The aggressive spillover hypothesis explains the persistence of this behavior as a maladaptive side effect
of positive selection on aggressiveness in a foraging context. The hypothesis predicts that the occurrence of sexual cannibalism
is explained by female aggressiveness but is not related to male phenotype or behavioral type. An alternative hypothesis invokes
sexual selection and makes the opposite prediction namely that sexual cannibalism is an expression of female choice and should
hence mainly target males of low quality. We tested the above hypotheses on a sexually dimorphic nephilid spider Nephilengys livida, known for male monopolization of females via genital damage, female genital plugging, and mate guarding, by staging mating
trials during which we recorded mating behaviors and occurrences of pre- and postcopulatory cannibalism. We did not restrict
assessment of aggressiveness to the mating and foraging context but also included aggression against same sex conspecifics.
To assess female personalities, i.e., consistent individual differences in behavior including aggressiveness, we repeatedly
tested them for intra-sex aggression, voracity towards prey, locomotory activity, and boldness. Females exhibited consistent
differences in intra-sex aggressiveness, latency to attack prey, and boldness. Aggressive females had shorter latencies to
attack prey and were more active than non-aggressive ones. In contrast to the predictions of the aggressive spillover hypothesis,
females that were aggressive towards prey and towards other females were not more likely to attack a male than non-aggressive
females. In support of the mate choice hypothesis, less aggressive males were more likely attacked and cannibalized than more
aggressive ones. This hints at sexual selection for aggressiveness in males and raises the question of mechanisms that maintain
variation in male aggressiveness. 相似文献
996.
Dispersal attempts can be costly and may often end in failure. Individuals should therefore only disperse when the benefits
of dispersal outweigh the costs. While previous research has focussed on aspects of the individual that may affect dispersal
success, social factors may also influence dispersal outcomes. One way of achieving successful dispersal could be through
cooperative, or coalition dispersal. I investigated this possibility in the cooperatively breeding Arabian babbler Turdoides squamiceps. I found that coalition dispersal appears to be an effective strategy to ensure the success of dispersal attempts, with coalitions
more successful than lone individuals at taking over the breeding position in a new group. Lone dispersal was more costly
than coalition dispersal, with lone individuals suffering a greater loss of body mass during dispersal attempts. These results
suggest a substantial short-term benefit for this type of cooperative behaviour. There was no evidence for dispersal polymorphism
in the population, with no detectable phenotypic difference between dispersers and non-dispersers or those that dispersed
as part of a coalition compared with those that dispersed alone. 相似文献
997.
John?A.?VucetichEmail author Leah?M.?Vucetich Rolf?O.?Peterson 《Behavioral ecology and sociobiology》2012,66(2):295-303
For a wide range of taxa, partial prey consumption (PPC) is a frequent occurrence. PPC may arise from physiological constraints
to gut capacity or digestive rate. Alternatively, PPC may represent an optimal foraging strategy. Assessments that clearly
distinguish between these causes are rare and have been conducted only for invertebrate species that are ambush predators
with extra-intestinal digestion (e.g., wolf spiders). We present the first strong test for the cause of PPC in a cursorial
vertebrate predator with intestinal digestion: wolves (Canis lupus) feeding on moose (Alces alces). Previous theoretical assessments indicate that if PPC represents an optimal foraging strategy and is not caused by physiological
limitations, then mean carcass utilization is negatively correlated with mean kill rate and the utilization of individual
carcasses is uncorrelated with time between kills. Wolves exhibit exactly this pattern. We explore how the typical portrayal
of PPC by wolves has been not only misleading but also detrimental to conservation by promoting negative attitudes toward
wolves. 相似文献
998.
László?Zsolt?GaramszegiEmail author Anders?Pape?M?ller 《Behavioral ecology and sociobiology》2012,66(1):107-119
Hamilton and Zuk (Science 218:384–387, 1982) supported their influential hypothesis of parasite-mediated sexual selection based on a positive interspecific correlation
between the prevalence of blood parasites and the expression of male displays in birds. However, subsequent studies provided
mixed support for this relationship after considering several confounding factors. Here, we revisit this fundamental prediction
by refining the analyses through implementation of recent methodological advancements. First, we distinguish between prevalence
data obtained through microscopic and molecular tools, as PCR-based detection methods may be more sensitive for detecting
infection. Second, we use quantitative estimates of both acoustic and visual signals of males, in which color measurements
adopt the perspective of avian vision. Third, applying modern phylogenetic comparative approaches, we correct for phylogenetic
inertia as well as heterogeneity in sampling effort. Fourth, we distinguish between prevalence transition states, as we compare
species with and without evidence of infection and also monitor changes in parasite prevalence only in species in which blood
parasites are detected. We show that given the considerable variation among populations, the repeatability of prevalence at
the within-species level is modest. We failed to detect a strong interspecific relationship between the prevalence of blood
parasites and sexual traits. However, we found that an evolutionary increase from zero to non-zero prevalence is likely to
be accompanied by an increase in trait expression in males, but further increase from non-zero prevalence to a higher level
of infection tends to be associated with a reduced degree of trait elaboration. Our results provide some support to the Hamilton
and Zuk hypothesis, but the relationship between blood parasites and male displays varies among traits depending on degree
of infection. 相似文献
999.
Thomas?KlefothEmail author Christian?Skov Jens?Krause Robert?Arlinghaus 《Behavioral ecology and sociobiology》2012,66(4):547-559
To showcase the importance of genotype × environment interactions and the presence of predation risk in the experimental assessment
of boldness in fish, we investigated boldness in terms of feeding behavior and refuge use in two genetically different populations
of juvenile carp (Cyprinus carpio) in two replicated experimental conditions in ponds and laboratory tanks. The populations were expected to exhibit genetic
differences in boldness due to differential evolutionary adaptation to low-predation-risk pond aquaculture conditions. Boldness
was measured in variants of open-field trials with and without implementation of additional predation risk-stimuli by angling
on feeding spots. Without explicit implementation of risk, genotypes adapted to low-risk environments, i.e., domesticated
mirror carp behaved consistently bolder than their less domesticated scaled conspecifics in the pond environment, but not
in the laboratory environment. When we implemented artificial risk-stimuli by angling on previously safe feeding spots, boldness
differences among genotypes also emerged in the laboratory environment, indicating strong genotype × environment effects on
boldness behavior of carp. The expected genetic basis of boldness differences among genotypes was clearly supported in the
pond environment, while the laboratory study revealed these patterns only under inclusion of explicit risk-stimuli. Our study
thus underscores that boldness may involve both a basal component that is expressed independently of obvious predation risk
(e.g., in open fields) and a component revealed in relation to explicit predation risk, and both dimensions may respond differently
in behavioral tests. 相似文献
1000.
Radionuclides from the U and Th natural series are present in alkaline rocks, which are used as feedstock in Brazil for the
production of raw phosphoric acid, which can be considered as a NORM (naturally occurring radioactive material). As a result
of the purification of raw phosphoric acid to food-grade phosphoric acid, two by-products are generated, i.e., solid and liquid
wastes. Taking this into account, the main aim of this study was to evaluate the fluxes of natural radionuclide in the production
of food-grade phosphoric acids in Brazil, to determine the radiological impact caused by ingestion of food-grade phosphoric
acid, and to evaluate the solid waste environmental hazards caused by its application in crop soils. Radiological characterization
of raw phosphoric acid, food-grade phosphoric acid, solid waste, and liquid waste was performed by alpha and gamma spectrometry.
The 238U, 234U, 226Ra, and 232Th activity concentrations varied depending on the source of raw phosphoric acid. Decreasing radionuclides activity concentrations
in raw phosphoric acids used by the producer of the purified phosphoric acid were observed as follows: Tapira (raw phosphoric
acid D) > Catal?o (raw phosphoric acids B and C) > Cajati (raw phosphoric acid A). The industrial purification process produces
a reduction in radionuclide activity concentrations in food-grade phosphoric acid in relation to raw phosphoric acid produced
in plant D and single raw phosphoric acid used in recent years. The most common use of food-grade phosphoric acid is in cola
soft drinks, with an average consumption in Brazil of 72 l per person per year. Each liter of cola soft drink contains 0.5 ml
of food-grade phosphoric acid, which gives an annual average intake of 36 ml of food-grade phosphoric acid per person. Under
these conditions, radionuclide intake through consumption of food-grade phosphoric acid per year per person via cola soft
drinks is not hazardous to human health in Brazil. Considering these annual additions of 238U, 226Ra, 232Th and 40K, and since these radionuclide should be homogeneously distributed in the upper 10 cm of soils with an assumed apparent density
of 1.5 g/cm3, a maximum increase of 0.19 ± 0.03 Bq kg−1 of soil is expected for 238U and 234U. Thus, the addition of solid waste as phosphate fertilizers to Brazilian agricultural soils does not represent a hazard
to the ecosystem or to human health. 相似文献