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1.
Bioaccumulation models take various elimination and uptake processes into account, estimating rates from chemical lipophilicity, expressed as the octanol-water partition ratio (Kow). Here, we focussed on metabolism, which transforms parent compounds into usually more polar metabolites, thus enhancing elimination. The aim of this study was to quantify the change in lipophilicity of relevant organic pollutants undergoing various biotransformation reactions in mammals. We considered oxidation reactions catalyzed by three enzyme groups: cytochrome P450 (CYP), alcohol dehydrogenase (ADH), and aldehyde dehydrogenase (ALDH). Estimated log Kow values of a selected dataset of parent compounds were compared with the log Kow of their first metabolites. The log Kow decreased by a factor that varies between 0 and −2, depending on the metabolic pathway. For reactions mediated by CYP, the decrease in Kow was one order of magnitude for hydroxylated and epoxidated compounds and two orders of magnitude for dihydroxylated and sulphoxidated xenobiotics. On the other hand, no significant change in lipophilicity was observed for compounds N-hydroxylated by CYP and for alcohols and aldehydes metabolized by ADH and ALDH. These trends could be anticipated by the calculus method of log Kow. Yet, they were validated using experimental log Kow values, when available. These relationships estimate the extent to which the elimination of pollutants is increased by biotransformation. Thus, the quantification of the Kow reduction can be considered as a first necessary step in an alternative approach to anticipate biotransformation rates, which are hard to estimate with existing methods. 相似文献
2.
Sorace A 《Environmental management》2001,28(4):547-560
Urban-agricultural parks could have some advantages to wildlife because of less intensive agricultural procedures, absence
of hunting pressure, and reduced human disturbance. In this study, the breeding and wintering bird communities and the small
mammal community in an urban-agricultural park of Rome were compared to those of a close urban park and a close agricultural
area just outside the city. The aim was to assess the best destination and management of wildlife in natural areas at the
urban–rural interface. Richness and diversity of bird communities were higher in the urban-agricultural park. Due to habitat
features and probably human disturbances, but not to urbanization, predation, and competition factors, the urban park drastically
reduces the abundance of decreasing open-land bird species. Abundance of these species was not significantly different in
the urban-agricultural park and in the agricultural area. In the urban-agricultural and urban park, bird and mammal pest species
were more abundant than they were in the agricultural area. Regarding decreasing abundance of small mammal species, no significant
difference among the study areas was observed. Urban-agricultural park is a better choice than urban park for wildlife. Thus,
a higher number of preserved urban natural areas should be devoted to urban-agricultural parks. However, to increase the abundance
of open-land species and in general wildlife, a less intensive management of cultivated and pasture patches is necessary. 相似文献
3.
Major fluorinated chemical manufacturers have developed new short-chain per- and polyfluorinated substances with more favorable environmental, health and safety profiles. This study provides the first evaluation of the elimination half-life of perfluorohexanoic acid (PFHxA) from the blood of humans. PFHxA biomonitoring data were obtained from a recently published study of professional ski wax technicians. These data were analyzed to provide estimates of the apparent half-life of PFHxA from humans, and comparisons were made with kinetic studies of PFHxA elimination from mice, rats and monkeys. The apparent elimination half-life of PFHxA in highly exposed humans ranged between 14 and 49 d with a geomean of 32 d. The half-lives of PFHxA in mice, rats, monkeys and humans were proportional to body weight with no differences observed between genders, indicating similar volumes of distribution and similar elimination mechanisms among mammalian species. Compared to long-chain perfluoroalkyl acid analogs, PFHxA is rapidly cleared from biota. The consistent weight-normalized elimination half-lives for PFHxA in mammalian species indicates that results obtained from animal models are suitable for establishment of PFHxA benchmark dose and reference dose hazard endpoints for use in human risk assessments. 相似文献
4.
Many vertebrates grow up in the company of same or different-age siblings, and relations among them can be expected to significantly
influence individual life histories and the development of individual morphological, physiological, and behavioral phenotypes.
Although studies in birds still dominate and have stimulated most theoretical considerations, the increasing number of mammalian
studies promises to broaden our understanding of this complex field by enabling interesting comparisons with the rather different
bird system. It therefore seems timely to bring together recent studies of sibling relations in mammals and to demonstrate
what these can offer in the way of fresh insights. In this brief review, intended to accompany a series of papers on a diverse
range of mammals, we outline the current state of sibling research in mammals, comparing it to the better studied birds. Most
obviously, in mammals, mother and young are in much closer contact during early life than in birds, and siblings can influence
each other’s development as well as the mother’s physiology while still in utero. During nursing, mammalian young also encounter
a very different feeding situation to bird siblings. These contrasts should help stimulate further debate, as well as provide
further opportunities to study the relative importance of maternal versus sibling effects on individual development. Finally,
we discuss the need to balance studies of sibling competition and conflict with a consideration of the benefits accruing to
individuals from sibling presence and the need for long-term studies of the influence of early sibling relations on individual
development and life histories.
This contribution represents the introduction to the special issue “Sibling competition and cooperation in mammals”. 相似文献
5.
Luciana M. Möller Luciano B. Beheregaray Simon J. Allen Robert G. Harcourt 《Behavioral ecology and sociobiology》2006,61(1):109-117
Kinship has been shown to be an important correlate of group membership and associations among many female mammals. In this study, we investigate association patterns in female Indo-Pacific bottlenose dolphins (Tursiops aduncus) inhabiting an embayment in southeastern Australia. We combine the behavioral data with microsatellite DNA and mitochondrial DNA data to test the hypotheses that genetic relatedness and maternal kinship correlate with associations and social clusters. Mean association between females was not significantly different from a random mean, but the standard deviation was significantly higher than a random standard deviation, indicating the presence of nonrandom associates in the dataset. A neighbor-joining tree, based on the distance of associations between females, identified four main social clusters in the area. Mean genetic relatedness between pairs of frequent female associates was significantly higher than that between pairs of infrequent associates. There was also a significant correlation between mtDNA haplotype sharing and the degree of female association. However, the mean genetic relatedness of female pairs within and between social clusters and the proportion of female pairs with the same and different mtDNA haplotypes within and between clusters were not significantly different. This study demonstrates that kinship correlates with associations among female bottlenose dolphins, but that kinship relations are not necessarily a prerequisite for membership in social clusters. We hypothesize that different forces acting on female bottlenose dolphin sociality appear to promote the formation of flexible groups which include both kin and nonkin. 相似文献
6.
A.C. Anderson 《Journal of environmental science and health. Part. B》2013,48(1):129-130
Chemical Hazards to Human Reproduction by Ian C. Nisbet and Nathan J. Karch, Noyes Data Corp., Park Ridge, N.J. (1983), 245 pp., $28.00. 相似文献
7.
Birth sex ratios in toque macaques and other mammals: integrating the effects of maternal condition and competition 总被引:2,自引:0,他引:2
Wolfgang P. J. Dittus 《Behavioral ecology and sociobiology》1998,44(3):149-160
Mammalian life histories suggest that maternal body condition and social dominance (a measure of resource-holding potential)
influence the physical and social development of offspring, and thereby their reproductive success. Predictably, a mother
should produce that sex of offspring which contributes most to her fitness (as measured by the number of her grandchildren)
and that she is best able to raise within the constraints imposed by her condition, social rank, and environment. Such combined
effects were investigated by monitoring variations in body condition (weight) and behavior of female toque macaques, Macaca sinica of Sri Lanka, in a changing forest environment over 18 years. Maternal rank, by itself, had no influence on offspring sex,
but did affect maternal body condition. The combined effects of rank and condition indicated the following: mothers in robust
condition bore more sons, whereas those in moderate condition bore more daughters, but both effects were expressed most strongly
among mothers of high rank. Where the consequences of low rank were felt most acutely, as shown by poor condition, mothers
underproduced daughters. Environmental quality directly influenced rank and condition interactions, and thus sex ratios. These
relationships, and data from other mammals suggest an empirically and theoretically consistent pattern of sex allocation in
mammals. New predictions integrate effects, proposed by Trivers and Willard, that are rooted in male mate competition, which
is universal among polygynous mammals, with those of local resource competition (and/or female reproductive competition),
which are not universal and differ in intensity between the socioecologies and local environments of different species.
Received: 30 May 1998 / Accepted after revision: 29 August 1998 相似文献
8.
A procedure for the assessment of emissions of nitrogen (N) species (ammonia, nitrous oxide, nitric oxide, di-nitrogen) from the manure management system is developed, which treats N pools and flows including emissions strictly according to conservation of mass criteria. As all relevant flows in the husbandry of mammals are depicted, the methodology is considered a Tier 3 approach in IPCC terminology or a detailed methodology in UN ECE terminology. The importance of accounting for all N species is illustrated by comparing emission estimates obtained using this approach with those obtained from the application the present detailed/Tier 2 methodology. 相似文献
9.
Amando Bautista Esmeralda García-Torres Margarita Martínez-Gómez Robyn Hudson 《Behavioral ecology and sociobiology》2008,62(3):331-339
Competition among mammalian siblings for scarce resources can be severe. Whereas research to date has focused on competition
for the mother’s milk, the young of many (particularly altricial) species might also be expected to compete for thermally
favorable positions within the nest, den, or litter huddle. We investigated this in newborn pups of the European rabbit Oryctolagus cuniculus, a species in which the altricial young are not brooded by the mother, and in which competition for milk is severe. In eight
unculled litters (N = 86 pups) of a domestic chinchilla strain, we calculated huddling indexes for individual pups on postnatal days 2–5 as a
measure of the degree of insulation they received from littermates. Pups maintained almost constant physical contact with
the litter huddle. They performed brief but frequent rooting and climbing behaviors, which usually improved their huddling
index, interspersed with longer periods of quiescence during which their huddling index declined. As expected, we found a
significant positive relation between pups’ mean huddling index and body temperature. Unexpectedly, however, we did not find
a relation between huddling index and pups’ birth weight, survival, milk intake, or efficiency of converting milk to body
mass. We conclude that rather than competing for thermally advantageous positions within the huddle newborn rabbits share
out thermally advantageous positions as they move in a continual dynamic flow through it. Thus, in newborn rabbits, competition
for the mother’s milk exists alongside mutual “cooperative” benefits of littermate presence.
This contribution is part of the special issue “Sibling competition and cooperation in mammals” (guest editors: Robyn Hudson
and Fritz Trillmich). 相似文献
10.
Albrecht?I.?Schulte-HosteddeEmail author John?S.?Millar 《Behavioral ecology and sociobiology》2004,55(3):272-277
Comparative analyses have found that relative testis size is a strong predictor of the prevalence of sperm competition for many taxa, including mammals, yet underlying this pattern is the assumption that intraspecific variation in testis size is related to individual fitness. Because intraspecific variation in ejaculate investment underlies interspecific patterns, it is critical to understand the causes and consequences of intraspecific variation in ejaculate investment. We examined relationships between ejaculate investment (testis size and sperm length) and reproductive success, body size and condition in the yellow-pine chipmunk (Tamias amoenus), a small ground squirrel in which sperm competition occurs. We examined genetic estimates of male reproductive success from a wild population of yellow-pine chipmunks and determined that males with large testes had higher annual reproductive success than males with small testes. This result provides empirical support for the numerous comparative studies that indicate testis size is associated with the intensity of sperm competition. In addition, males in good condition had relatively larger testes than males in poor condition, but there was no evidence of sperm length being dependent on condition. Finally, contrary to many predictions, males that invested more in sperm production (relatively heavy testes) produced shorter sperm, not longer sperm, than males that invested less.Communicated by P.M. Kappeler 相似文献