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81.
82.
Jessica L. Decker Sparks Bridget Camacho Philip Tedeschi 《Journal of applied animal welfare science : JAAWS》2018,21(2):120-129
A retrospective database analysis (2011–2015) evaluated associations between race and ethnicity and veterinary service utilization by sampling 83,260 companion animals whose guardians (owners) self-identified as White, Black, or Latino/a from 39 Humane Society of the United States Pets for Life (PFL) sites across the United States. Controlling for socioeconomic status, the percentage of nonhuman animals sterilized through PFL whose owners were Latino/a or Black was substantially higher than in previously reported findings. While Latinos/as had the highest mean number of days from first contact with the program to consent, they also had the highest percentage of owners accepting the voucher during initial contact. Logistic regression models suggested that although meaningful, race and ethnicity were not primary determinants of veterinary service utilization. When veterinary and animal welfare organizations deliberately remove structural barriers embedded with racial inequalities, individuals, regardless of race and ethnicity, proceed with companion-animal sterilization. Therefore, service providers must use unbiased, informed, and culturally competent practices to improve companion-animal welfare through the optimization of veterinary services, including spay and neuter. 相似文献
83.
The importance of shelter for butterflies in open landscapes 总被引:2,自引:0,他引:2
In Britain, much emphasis has been placed on conserving butterfly species in specialized habitats, since this is where most of its threatened butterflies exist, whilst the wider countryside has been largely overlooked. However, there is increasing awareness that small improvements to the dominant landscape could potentially reap huge benefits to the populations of many of Britains butterfly species. Recent studies have also stressed the importance of the landscape scale in the conservation of butterflies in small fragmented habitats. In this paper, we examine data from a variety of sources and conclude that the importance of shelter in open landscapes may be underestimated since recording is often restricted to the optimum conditions suggested by the Butterfly Monitoring Scheme. In less favourable conditions, butterflies may place greater reliance on those components of the landscape offering shelter. In light of the current policy of agricultural de-intensification we discuss how modifications to our current landscapes could benefit a wide range of species. 相似文献
84.
Buecher Emmanuelle; Sparks Conrad; Brierley Andrew; Boyer Helen; Gibbons Mark 《Journal of plankton research》2001,23(10):1073-1080
Novel data on the biometry, size distribution and parasitesof Aequorea aequorea and Chrysaora hysoscella are provided frominvestigations conducted during summer and winter in the northernBenguela ecosystem. The relationship between mass and diameterof C. hysoscella did not change on a seasonal basis, and thispossibly reflects the aseasonal nature of the food environment.The changes in the size structure of C. hysoscella across theshelf and with depth agree with postulated population maintenancestrategies in the region. Aequorea aequorea was not stronglyparasitized, butC. hysoscella was subject to occasional parasitismby Hyperia medusarum, especially in winter when C. hysoscellais thought to reproduce. Parasites were distributed in a typical,negative-binomial manner on their hosts, but load was independentof host size. As medusae increased in diameter so H. medusarumtended to move from other tissues to the gonads. 相似文献
85.
Juvenile hormone esterase titres were monitored in gate I and gate II last instar larvae of Trichoplusia ni using JH III as substrate. Two peaks of activity were observed for both gate I and gate II larvae, although the first and second juvenile hormone esterase peaks for the gate II larvae are extended and delayed one day, respectively. Head or thoracic ligations before the prepupal stage lower or block the appearance of both esterase peaks. Juvenile hormone I and II, as well as homo and dihomo juvenoids can induce the second juvenile hormone esterase peak in both normal and ligated larvae, and increase the esterase titre during the first peak in nonligated larvae. Induction of the juvenile hormone esterases is possible in non-ligated larvae as soon as the moult to the last instar has occurred and in ligated larvae as soon as the first esterase peak has started to decline. Distinct mechanisms of regulation are present for the first and second juvenile hormone esterase peaks. Juvenile hormone does not appear to be involved in regulating its own metabolism by directly inducing the first esterase peak; however, evidence is consistent with a brief burst of juvenile hormone which occurs prior to pupation inducing the production of the second peak of juvenile hormone esterase activity. 相似文献
86.
87.
Seston quality controls zebra mussel (Dreissena polymorpha ) energetics in turbid rivers 总被引:3,自引:1,他引:2
Daniel W. Schneider Sharook P. Madon James A. Stoeckel Richard E. Sparks 《Oecologia》1998,117(3):331-341
Feeding processes and energetic balance of zebra mussels were both related to the quantity and quality of natural seston.
Filtration rate and pseudofeces production increased while clearance rate remained constant with increasing seston concentration.
Ingestion rate, assimilation efficiency, and assimilation rate all increased with increasing food quality, measured as the
ratio of organic to inorganic material in the seston. Respiration rate did not change with either food quantity or quality.
As a result, scope for growth declined with decreasing food quality, and fell below 0 cal mg−1 h−1 at an organic:inorganic ratio of 0.5. The association between feeding processes and food quality appears related to a breakdown
in the ability of zebra mussels to selectively ingest high-quality organic particles when the organic content of the seston
is low. Ingestion, assimilation efficiency, assimilation rate and scope for growth were all higher when seston was amended
with an addition of a natural assemblage of algae. Food quality may be a better indicator of environmental conditions suitable
for growth than food quantity. These results suggest that the conditions of high suspended inorganic sediment concentrations
in large turbid rivers represent a difficult growth environment for the zebra mussel.
Received: 12 May 1997 / Accepted: 7 July 1998 相似文献
88.
Summary Measuring the cough frequency of bluegills by means of a cannula inserted through the snout into the buccal cavity is a good monitoring technique for zinc (and probably other heavy metals) because the response is quick, is proportional to the toxicant concentration and occurs at sublethal concentrations. 相似文献
89.
90.
DALDINIA CONCENTRICA ATTACKING THE WOOD OF FRAXINUS EXCELSIOR 总被引:1,自引:0,他引:1