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41.
Background
Norms clarification has been identified as an effective component of college student drinking interventions, prompting research on norms clarification as a single-component intervention known as Personalized Normative Feedback (PNF). Previous reviews have examined PNF in combination with other components but not as a stand-alone intervention.Objectives
To investigate the degree to which computer-delivered stand-alone personalized normative feedback interventions reduce alcohol consumption and alcohol-related harms among college students and to compare gender-neutral and gender-specific PNF.Data Sources
Electronic databases were searched systematically through November 2014. Reference lists were reviewed manually and forward and backward searches were conducted.Selection Criteria
Outcome studies that compared computer-delivered, stand-alone PNF intervention with an assessment only, attention-matched, or active treatment control and reported alcohol use and harms among college students.Methods
Between-group effect sizes were calculated as the standardized mean difference in change scores between treatment and control groups divided by pooled standard deviation. Within-group effect sizes were calculated as the raw mean difference between baseline and follow-up divided by pooled within-groups standard deviation.Results
Eight studies (13 interventions) with a total of 2,050 participants were included. Compared to control participants, students who received gender-neutral (d between = 0.291, 95% CI [0.159, 0.423]) and gender-specific PNF (d between = 0.284, 95% CI [0.117, 0.451]) reported greater reductions in drinking from baseline to follow-up. Students who received gender-neutral PNF reported 3.027 (95% CI [2.171, 3.882]) fewer drinks per week at first follow-up and gender-specific PNF reported 3.089 (95% CI [0.992, 5.186]) fewer drinks. Intervention effects were small for harms (d between = 0.157, 95% CI [0.037, 0.278]).Conclusions
Computer-delivered PNF is an effective stand-alone approach for reducing college student drinking and has a small impact on alcohol-related harms. Effects are small but clinically relevant when considered from a public health perspective. Additional research is needed to examine computer-delivered, stand-alone PNF as a population-level prevention program. 相似文献42.
Positive size assortative mating can arise if either one or both sexes prefer bigger mates or if the success of larger males
in contests for larger females leaves smaller males to mate with smaller females. Moreover, body size could not only influence
pairing patterns before copulation but also the covariance between female size and size of ejaculate (number of spermatophores)
transferred to a mate. In this field study, we examine the pre-copulatory mate choice, as well as insemination, patterns in
the Cook Strait giant weta (Deinacrida rugosa). D. rugosa is a large orthopteran insect that exhibits strong female-biased sexual dimorphism, with females being nearly twice as heavy
as males. Contrary to the general expectation of male preference for large females in insects with female-biased size dimorphism,
we found only weak support for positive size assortative mating based on size (tibia length). Interestingly, although there
was no correlation between male body size and the number of spermatophores transferred, we did find that males pass more spermatophores
to lighter females. This pattern of sperm transfer does not appear to be a consequence of those males that mate heavier females
being sperm depleted. Instead, males may provide lighter females with more spermatophores perhaps because these females pose
less of a sperm competition risk to mates. 相似文献
43.
Visual opsins bind 11-cis retinal at an orthosteric site to form rhodopsins but increasing evidence suggests that at least some are capable of binding an additional retinoid(s) at a separate, allosteric site(s). Microspectrophotometric measurements on isolated, dark-adapted, salamander photoreceptors indicated that the truncated retinal analog, β-ionone, partitioned into the membranes of green-sensitive rods; however, in blue-sensitive rod outer segments, there was an enhanced uptake of four or more β-ionones per rhodopsin. X-ray crystallography revealed binding of one β-ionone to bovine green-sensitive rod rhodopsin. Cocrystallization only succeeded with extremely high concentrations of β-ionone and binding did not alter the structure of rhodopsin from the inactive state. Salamander green-sensitive rod rhodopsin is also expected to bind β-ionone at sufficiently high concentrations because the binding site is present on its surface. Therefore, both blue- and green-sensitive rod rhodopsins have at least one allosteric binding site for retinoid, but β-ionone binds to the latter type of rhodopsin with low affinity and low efficacy. 相似文献
44.
Evelynne Tinkler W. Ian Montgomery & Robert W. Elwood 《Ethology : formerly Zeitschrift fur Tierpsychologie》2007,113(4):368-376
We examine brood size effects on the behaviour of wintering parent and juvenile brent geese (Branta bernicla hrota) to test predictions of shared and unshared parental care models. The behaviour of both parents and offspring appear to be influenced by declining food availability over the winter. Parental vigilance increased with brood size and may be explained by vigilance having functions in addition to antipredator behaviour where the benefits are shared among the brood. There was no increase in parental aggression with brood size and this does not fit the prediction of shared care. Nevertheless, large families are able to monopolize better feeding areas compared with smaller families and large families static feed more but walk feed less than do small families, the former apparently being the preferred mode. The presence of additional young, rather than increasing the amount of parental aggression, seems to enhance the family's competitive ability. Because parents with large broods benefit from enhanced access to resources there is likely to be no additional significant cost in the parental care of larger broods (sensu Trivers 1972 ). 相似文献
45.
John Prenter Robert W. Elwood W. Ian Montgomery 《Evolution; international journal of organic evolution》1999,53(6):1987-1994
We investigate the association between female reproductive investment, absolute size, and sexual size dimorphism in spiders to test the predictions of the fecundity-advantage hypothesis. The relationships between absolute size and sexual size dimorphism and aspects of female reproductive output are examined in comparative analyses using phylogenetically independent contrasts. We provide support for the idea that allometry for sexual dimorphism is the result of variation in female size more so than male size. Regression analyses suggest selection for increased fecundity in females. We argue that fecundity selection provides the only general explanation for the evolution of sexual size dimorphism in spiders. 相似文献
46.
Zhang J Dalal N Matthews MA Waller LN Saunders C Fox KF Fox A 《Journal of microbiological methods》2007,70(3):442-451
The present work examines chemical and structural response in B. anthracis spores killed by a mixture of supercritical carbon dioxide (SCCO2) and hydrogen peroxide (H2O2). Deactivation of 6-log of B. anthracis spores by SCCO2 + H2O2 was demonstrated, but changes in structure were observed in only a small portion of spores. Results from phase contrast microscopy proved that this treatment is mild and does not trigger germination-like changes. TEM imaging revealed mild damage in a portion of spores while the majority remained intact. Dipicolinic acid (DPA) analysis showed that < 10% of the DPA was released from the spore core into the external milieu, further demonstrating only modest damage to the spores. Confocal fluorescent microscopy, assessing uptake of DNA-binding dyes, directly demonstrated compromise of the permeability barrier. However, the magnitude of uptake was small compared to spores that had been autoclaved. This work suggests that SCCO2 + H2O2 is quite mild compared to other sterilization methods, which has major implications in its application. These results provide some insight on the possible interactions between spores and the SCCO2 + H2O2 sterilization process. 相似文献
47.
Shiina T Briles WE Goto RM Hosomichi K Yanagiya K Shimizu S Inoko H Miller MM 《Journal of immunology (Baltimore, Md. : 1950)》2007,178(11):7162-7172
MHC haplotypes have a remarkable influence on whether tumors form following infection of chickens with oncogenic Marek's disease herpesvirus. Although resistance to tumor formation has been mapped to a subregion of the chicken MHC-B region, the gene or genes responsible have not been identified. A full gene map of the subregion has been lacking. We have expanded the MHC-B region gene map beyond the 92-kb core previously reported for another haplotype revealing the presence of 46 genes within 242 kb in the Red Jungle Fowl haplotype. Even though MHC-B is structured differently, many of the newly revealed genes are related to loci typical of the MHC in other species. Other MHC-B loci are homologs of genes found within MHC paralogous regions (regions thought to be derived from ancient duplications of a primordial immune defense complex where genes have undergone differential silencing over evolutionary time) on other chromosomes. Still others are similar to genes that define the NK complex in mammals. Many of the newly mapped genes display allelic variability and fall within the MHC-B subregion previously shown to affect the formation of Marek's disease tumors and hence are candidates for genes conferring resistance. 相似文献
48.
Ermolenko DN Majumdar ZK Hickerson RP Spiegel PC Clegg RM Noller HF 《Journal of molecular biology》2007,370(3):530-540
Protein synthesis is believed to be a dynamic process, involving structural rearrangements of the ribosome. Cryo-EM reconstructions of certain elongation factor G (EF-G)-containing complexes have led to the proposal that translocation of tRNA and mRNA through the ribosome, from the A to P to E sites, is accompanied by a rotational movement between the two ribosomal subunits. Here, we have used F?rster resonance energy transfer (FRET) to monitor changes in the relative orientation of the ribosomal subunits in different complexes trapped at intermediate stages of translocation in solution. Binding of EF-G to the ribosome in the presence of the non-hydrolyzable GTP analogue GDPNP or GTP plus fusidic acid causes an increase in the efficiency of energy transfer between fluorophores introduced into proteins S11 in the 30 S subunit and L9 in the 50 S subunit, and a decrease in energy transfer between S6 and L9. Similar anti-correlated changes in energy transfer occur upon binding the GTP-requiring release factor RF3. These changes are consistent with the counter-clockwise rotation of the 30 S subunit relative to the 50 S subunit observed in cryo-EM studies. Reaction of ribosomal complexes containing the peptidyl-tRNA analogues N-Ac-Phe-tRNAPhe, N-Ac-Met-tRNAMet or f-Met-tRNAfMet with puromycin, conditions favoring movement of the resulting deacylated tRNAs into the P/E hybrid state, leads to similar changes in FRET. Conversely, treatment of a ribosomal complex containing deacylated and peptidyl-tRNAs bound in the A/P and P/E states, respectively, with EF-G.GTP causes reversal of the FRET changes. The use of FRET has enabled direct observation of intersubunit movement in solution, provides independent evidence that formation of the hybrid state is coupled to rotation of the 30 S subunit and shows that the intersubunit movement is reversed during the second step of translocation. 相似文献
49.
50.
Clint A. Penick Amy M. Savage Robert R. Dunn 《Proceedings. Biological sciences / The Royal Society》2015,282(1806)
The amount of energy consumed within an average city block is an order of magnitude higher than that consumed in any other ecosystem over a similar area. This is driven by human food inputs, but the consequence of these resources for urban animal populations is poorly understood. We investigated the role of human foods in ant diets across an urbanization gradient in Manhattan using carbon and nitrogen stable isotopes. We found that some—but not all—ant species living in Manhattan''s most urbanized habitats had δ13C signatures associated with processed human foods. In particular, pavement ants (Tetramorium sp. E) had increased levels of δ13C similar to δ13C levels in human fast foods. The magnitude of this effect was positively correlated with urbanization. By contrast, we detected no differences in δ15N, suggesting Tetramorium feeds at the same trophic level despite shifting to human foods. This pattern persisted across the broader ant community; species in traffic islands used human resources more than park species. Our results demonstrate that the degree urban ants exploit human resources changes across the city and among species, and this variation could play a key role in community structure and ecosystem processes where human and animal food webs intersect. 相似文献