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101.
ADAM J. VANBERGEN BEN A. WOODCOCK MATTI KOIVULA JARI NIEMELÄ D. JOHAN KOTZE TOM BOLGER VALERIE GOLDEN FLORENCE DUBS GUILLAUME BOULANGER JOSE SERRANO JOSÉ LUÍS LENCINA ARTUR SERRANO CARLOS AGUIAR ANNE‐CATHERINE GRANDCHAMP SILVIA STOFER GYÖZÖ SZÉL EVA IVITS PETRA ADLER JOCHUM MARKUS ALLAN D. WATT 《Ecological Entomology》2010,35(2):226-235
1. Anthropogenic pressures have produced heterogeneous landscapes expected to influence diversity differently across trophic levels and spatial scales. 2. We tested how activity density and species richness of carabid trophic groups responded to local habitat and landscape structure (forest percentage cover and habitat richness) in 48 landscape parcels (1 km2) across eight European countries. 3. Local habitat affected activity density, but not species richness, of both trophic groups. Activity densities were greater in rotational cropping compared with other habitats; phytophage densities were also greater in grassland than forest habitats. 4. Controlling for country and habitat effects, we found general trophic group responses to landscape structure. Activity densities of phytophages were positively correlated, and zoophages uncorrelated, with increasing habitat richness. This differential functional group response to landscape structure was consistent across Europe, indicated by a lack of a country × habitat richness interaction. Species richness was unaffected by landscape structure. 5. Phytophage sensitivity to landscape structure may arise from relative dependency on seed from ruderal plants. This trophic adaptation, rare in Carabidae, leads to lower phytophage numbers, increasing vulnerability to demographic and stochastic processes that the greater abundance, species richness, and broader diet of the zoophage group may insure against. 相似文献
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103.
DINESH BHUGRA SUSHAM GUPTA KAMALDEEP BHUI TOM CRAIG NISHA DOGRA J. DAVID INGLEBY JAMES KIRKBRIDE DRISS MOUSSAOUI JAMES NAZROO ADIL QURESHI THOMAS STOMPE RACHEL TRIBE 《World psychiatry》2011,10(1):2-10
The purpose of this guidance is to review currently available evidence
on mental health problems in migrants and to present advice to clinicians
and policy makers on how to provide migrants with appropriate and accessible
mental health services. The three phases of the process of migration and the
relevant implications for mental health are outlined, as well as the specific
problems of groups such as women, children and adolescents, the elderly, refugees
and asylum seekers, and lesbian, gay, bisexual and transgender individuals.
The concepts of cultural bereavement, cultural identity and cultural congruity
are discussed. The epidemiology of mental disorders in migrants is described.
A series of recommendations to policy makers, service providers and clinicians
aimed to improve mental health care in migrants are provided, covering the
special needs of migrants concerning pharmacotherapies and psychotherapies. 相似文献
104.
TOM S. SMITH STEPHEN HERRERO TERRY D. DEBRUYN JAMES M. WILDER 《The Journal of wildlife management》2008,72(3):640-645
Abstract: We present a comprehensive look at a sample of bear spray incidents that occurred in Alaska, USA, from 1985 to 2006. We analyzed 83 bear spray incidents involving brown bears (Ursus arctos; 61 cases, 74%), black bears (Ursus americanus; 20 cases, 24%), and polar bears (Ursus maritimus; 2 cases, 2%). Of the 72 cases where persons sprayed bears to defend themselves, 50 (69%) involved brown bears, 20 (28%) black bears, and 2 (3%) polar bears. Red pepper spray stopped bears' undesirable behavior 92% of the time when used on brown bears, 90% for black bears, and 100% for polar bears. Of all persons carrying sprays, 98% were uninjured by bears in close-range encounters. All bear—inflicted injuries (n = 3) associated with defensive spraying involved brown bears and were relatively minor (i.e., no hospitalization required). In 7% (5 of 71) of bear spray incidents, wind was reported to have interfered with spray accuracy, although it reached the bear in all cases. In 14% (10 of 71) of bear spray incidents, users reported the spray having had negative side effects upon themselves, ranging from minor irritation (11%, 8 of 71) to near incapacitation (3%, 2 of 71). Bear spray represents an effective alternative to lethal force and should be considered as an option for personal safety for those recreating and working in bear country. (JOURNAL OF WILDLIFE MANAGEMENT 72(3):640–645; 2008) 相似文献
105.
KINCHEL C. DOERNER WES BRADEN JENNIFER CORK TOM CUNNINGHAM AMANDA RICE BONNIE J. FURMAN DOUG McELROY 《The Journal of wildlife management》2005,69(1):345-355
Abstract: White-tailed deer (Odocoileus virginianus) in Kentucky represent an example of successful wildlife restoration. Eliminated from all but a few remnant areas by the early part of the twentieth century, the species is once again widely distributed and abundant as a result of intensive restocking efforts since the 1940s. Seven DNA microsatellite markers were used to survey the extent and pattern of genetic variation in 322 deer from multiple localities throughout the commonwealth. Six genetically homogeneous regions and 1 heterogeneous region were identified across Kentucky. High levels of allelic diversity were detected with no apparent reduction in heterozygosity, disproportionate loss of rare alleles, or shift in modal allele frequency class as might be expected if the severe historical population size reduction generated a concomitant genetic bottleneck. These results are consistent with predictions of founder-flush models: that rapid population growth may minimize the loss of genetic variability associated with a population bottleneck. Nevertheless, comparisons of our data to that derived from other imperiled taxa suggest that species demographics can also play an important role in determining the genetic consequences of population size reduction and subsequent recovery. Our data also illuminate the critical role of deer from Land Between the Lakes (LBL) as the initial source population from which all extant Kentucky deer are descended. While generally supporting current regional management perspectives, our results argue for recognition of the LBL herd as a distinct management island of genetic and historical value. 相似文献
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107.
BRENT J. SINCLAIR AMANDA BRETMAN TOM TREGENZA JOSEPH L. TOMKINS DAVID J. HOSKEN 《Physiological Entomology》2011,36(1):84-89
Many behavioural traits are considered to be condition‐dependent, reflecting the differential allocation of resources to fitness‐related traits and maintenance, although the physiological underpinnings of condition dependence are not well understood. In the present study, the hypothesis that condition dependence in male Gryllus bimaculatus De Geer is mediated by a decrease in metabolic rate with declining condition is tested. CO2 production is measured by flow‐through respirometry, with insect condition manipulated through starvation. Crickets starved for 7 days have lower CO2 emission rates than individuals starved for only 24 h. However, carbohydrate reserves are depleted in the first 3 days, suggesting that the initial metabolism is primarily fuelled by carbohydrate, with a shift to lipid stores after 3 days. If the metabolic rate is estimated using respiratory quotients reflecting this shift in fuels, there is no difference in metabolic rate between crickets starved for 24 h and 7 days, suggesting that metabolic rate does not decrease with declining condition. This implies that a decrease in metabolic rate during starvation may not be a general pattern in insects, and emphasizes the need to consider fuel use during metabolic rate estimation in starvation studies. 相似文献
108.
Riverine transport of organic carbon (OC) to the ocean is a significant component in the global carbon (C) cycle and the concentration of total organic carbon (TOC) in rivers and lakes is vital for ecosystem properties and water quality for human use. By use of a large dataset comprising chemical variables and detailed catchment information in ~1000 Norwegian pristine lakes covering a wide climatic range, we were able to predict TOC concentrations with high accuracy. We further predict, using a ‘space‐for‐time’ approach and a downscaled, moderate, climate change scenario, that northern, boreal regions likely will experience strong increases in OC export from catchments to surface waters. Median concentrations of OC in these lakes will increase by 65%, from the current median of 2.0–3.3 mg C L?1. This is a long‐term effect, primarily mediated by increased terrestrial vegetation cover in response to climate change. This increase OC will have severe impacts on food‐webs, productivity and human use. Given the robustness of the estimates and the general applicability of the parameters, we suggest that these findings would be relevant to boreal areas in general. 相似文献
109.
TOM J. CADE 《The Journal of wildlife management》2007,71(7):2125-2133
ABSTRACT The scientific evidence that California condors (Gymnogyps californianus) are frequently sickened and killed by lead poisoning from spent ammunition supports the conclusion that current levels of lead exposure are too high to allow reintroduced condors to develop self-sustaining populations in the wild in Arizona and, by inference, in California. The evidence for lead poisoning and its source comes from the following sorts of data: 1) 18 clinical necropsies revealing high levels of lead in body tissues and (or) presence of lead shotgun pellets and bullet fragments in digestive tracts; 2) moribund condors showing crop paralysis and impending starvation with toxic levels of lead in their blood; 3) widespread lead exposure among free-flying condors, many with clinically exposed or acute levels; 4) temporal and spatial correlations between big game hunting seasons and elevated lead levels in condors; and 5) lead isotope ratios from exposed condors showing close similarity to isotope ratios of ammunition lead but isotope ratios in less exposed condors being similar to environmental background sources, which are different from ammunition lead. Simple population models reveal harmful demographic impacts of unnatural mortality from lead on population trajectories of reintroduced condors. Recent innovations in the manufacture of nonlead shotgun pellets and bullets with superior ballistics now provide for a simple solution to the problem of lead ingestion by condors, many other species of wildlife, and human beings: substitute nontoxic forms of ammunition for traditional lead-based ammunition. The substitution of nontoxic ammunition would be highly efficacious for hunting, economically feasible, and the right thing to do. 相似文献
110.
Recently, contradicting evidence has been reported on the contribution of xylem and phloem influx into tomato fruits, urging the need for a better understanding of the mechanisms involved in fruit growth. So far, little research has been performed on quantifying the effect of light intensity on the different contributors to the fruit water balance. However, as light intensity affects both transpiration and photosynthesis, it might be expected to induce important changes in the fruit water balance. In this study, tomato plants (Solanum lycopersicum L.) were grown in light and shade conditions and the fruit water balance was studied by measuring fruit growth of girdled and intact fruits with linear variable displacement transducers combined with a model‐based approach. Results indicated that the relative xylem contribution significantly increased when shading lowered light intensity. This resulted from both a higher xylem influx and a lower phloem influx during the daytime. Plants from the shade treatment were able to maintain a stronger gradient in total water potential between stem and fruits during daytime, thereby promoting xylem influx. It appeared that the xylem pathway was still functional at 35 days after anthesis and that relative xylem contribution was strongly affected by environmental conditions. 相似文献