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151.
Robert O. Deaner David C. Geary David A. Puts Sandra A. Ham Judy Kruger Elizabeth Fles Bo Winegard Terry Grandis 《PloS one》2012,7(11)
Much evidence indicates that men experienced an evolutionary history of physical competition, both one-on-one and in coalitions. We thus hypothesized that, compared to girls and women, boys and men will possess a greater motivational predisposition to be interested in sports, especially team sports. According to most scholars, advocacy groups, and the United States courts, however, this hypothesis is challenged by modest sex differences in organized school sports participation in the contemporary U.S., where females comprise 42% of high school participants and 43% of intercollegiate participants. We conducted three studies to test whether organized school sports participation data underestimate the actual sex difference in sports participation. Study 1 analyzed the American Time Use Survey, which interviewed 112,000 individuals regarding their activities during one day. Females accounted for 51% of exercise (i.e., non-competitive) participations, 24% of total sports participations, and 20% of team sports participations. These sex differences were similar for older and younger age groups. Study 2 was based on systematic observations of sports and exercise at 41 public parks in four states. Females accounted for 37% of exercise participations, 19% of individual sports participations, and 10% of team sports participations. Study 3 involved surveying colleges and universities about intramural sports, which primarily consist of undergraduate participation in team sports. Across 34 institutions, females accounted for 26% of registrations. Nine institutions provided historical data, and these did not indicate that the sex difference is diminishing. Therefore, although efforts to ensure more equitable access to sports in the U.S. (i.e., Title IX) have produced many benefits, patterns of sports participation do not challenge the hypothesis of a large sex difference in interest and participation in physical competition. 相似文献
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153.
François Mesléard Laurine Tan Ham Vincent Boy Carla van Wijck Patrick Grillas 《Oecologia》1993,94(2):204-209
Paspalum paspalodes, an introduced grass species, and Aeluropus littoralis, an indigenous species, develop abundantly in seasonally-flooded marshes in the Camargue (Rhône Delta, France). Although they occur together in many multispecies communities, neither species occurs when the other is dominat. The cultivation of cuttings of P. paspalodes and A. littoralis in a replacement series in a combination of five proportions (0/100, 25/75, 50/50, 75/25 and 100/0) and four salinities (0,2 4, and 6 g Cl- · 1-1) gave contrasting results for the two species: (1) strong asymmetrical competition in favour of P. paspalodes at 0 g Cl- · 1-1, (2) no significant effect of salinity on the mean above-ground and underground yields per plant for A. littoralis over the range tested, (3) a major decrease in the mean above-ground and belowground yields per plant for P. paspalodes with increasing salinity, (4) a reversal of the competitive balance between the species with increasing salinity. The cultivation of cuttings at high temperatures in a greenhouse in a combination of the same five proportions at two salinities (0 and 4 g Cl- · 1-1) refuted the hypothesis that the introduced species is better adapted to summer temperatures. Because it is not salt-tolerant, P. paspalodes cannot be considered as a potentially invasive species in the Camargue. Its abundance depends on newly created and artificially maintained habitats. 相似文献
154.
Grégoire Moutardier Sompert Gereva Suzanne C. Mills Mehdi Adjeroud Ricardo Beldade Jayven Ham Rocky Kaku Pascal Dumas 《PloS one》2015,10(9)
Outbreaks of the corallivorous crown-of-thorns seastar Acanthaster planci (COTS) represent one of the greatest disturbances to coral reef ecosystems in the Indo-Pacific, affecting not only coral reefs but also the coastal communities which rely on their resources. While injection approaches are increasingly used in an attempt to control COTS densities, most of them display severe drawbacks including logistical challenges, high residual environmental impacts or low cost-effectiveness. We tested a new alternative control method based upon acidic injections of cheap, 100% natural products. We investigated the lethal doses, intra- and inter-specific disease transmission and immune responses of COTS when injected with fresh lime juice (extracted from local Citrus arantifolia) and white spirit vinegar. High COTS mortality was achieved with small volumes: 10–20 ml per seastar induced death in 89%/97% of injected specimens after an average 34.3 h/29.8 h for lime juice and vinegar respectively. Highest efficiency was reached for both solutions with double shots of (2 × 10 ml) in two different areas on the body: 100% mortality occurred within 12–24 h, which is similar or faster compared with other current injection methods. Multiple immune measures suggested that death was very likely caused by pH stress from the acidic solutions rather than a bacterial infection. Contagion to either conspecifics or a variety of other reef species was not observed, even at COTS densities 15 times higher than the highest naturally reported. 10 to 20 l lime juice/vinegar could kill up to a thousand COTS at a cost of less than 0.05 USD per specimen; no permits or special handling procedures are required. We conclude that injections of lime juice and vinegar offer great advantages when compared to current best practises and constitute a cheap and natural option for all reefs affected by COTS. 相似文献
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JH Lee VD Valeriano YR Shin JP Chae GB Kim JS Ham J Chun DK Kang 《Journal of bacteriology》2012,194(17):4766
Lactobacillus mucosae LM1, isolated from stool samples of a healthy piglet, displays good in vitro mucin adhesion and antimicrobial activity against pathogenic bacteria. To elucidate its antimicrobial effects and to find its epithelial cell and mucin adhesion genes, the genomic sequence of L. mucosae LM1 was investigated. 相似文献
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160.
Yim H Hwang IS Choi JS Chun KH Jin YH Ham YM Lee KY Lee SK 《The Journal of cell biology》2006,174(1):77-88
We show that caspase-3 cleaves Cdc6 at D(290)/S and D(442)/G sites, producing p32-tCdc6 (truncated Cdc6) and p49-tCdc6, respectively, during etoposide- or tumor necrosis factor (TNF)-alpha-induced apoptosis. The expression of these tCdc6 proteins, p32- and p49-tCdc6, promotes etoposide-induced apoptosis. The expression of tCdc6 perturbs the loading of Mcm2 but not Orc2 onto chromatin and activates ataxia telangiectasia mutated (ATM) and ATM and Rad-3 related (ATR) kinase activities with kinetics similar to that of the phosphorylation of Chk1/2. The activation kinetics are consistent with elevated cellular levels of p53 and mitochondrial levels of Bax. The tCdc6-induced effects are all suppressed to control levels by expressing a Cdc6 mutant that cannot be cleaved by caspase-3 (Cdc6-UM). Cdc6-UM expression attenuates the TNF-alpha-induced activation of ATM and caspase-3 activities. When ATM or ATR is down-expressed by using the small interfering RNA technique, the TNF-alpha- or tCdc6-induced activation of caspase-3 activities is suppressed in the cells. These results suggest that tCdc6 proteins act as dominant-negative inhibitors of replication initiation and that they disrupt chromatin structure and/or induce DNA damage, leading to the activation of ATM/ATR kinase activation and p53-Bax-mediated apoptosis. 相似文献