321 research outputs found

    Challenges Facing the Religious Community in Addressing Global Climate Change

    Get PDF
    There are several key influences at play in the relationship between religion and a concern for nature and the environment, particularly as it relates to an issue like global climate change. These trends directly affect the ability of religion to influence public ideas, public policy, and political will. These situations and trends are particularly applicable to the situation in the United States

    Two Mechanical Engineering Students Named Inaugural Hino Motors Scholars

    Get PDF
    David Biggs and Manny Dhaliwal benefit from financial and professional suppor

    Identifying Determinants of Match Performance in Division I Women’s Collegiate Soccer Players

    Get PDF
    The purpose of this dissertation was to better understand position specific physical qualities and how they relate to high speed running performance throughout the course of a competitive collegiate soccer season. The amount of literature devoted to female soccer players is scarce when compared to the vast amount of literature associated with male soccer players. The objectives of this dissertation were: 1) to determine if playing position has an influence on physical qualities such as speed, change of direction ability, countermovement jump performance, relative strength, rate of force development, and intermittent endurance capacity, 2) investigate the differences between high and lower caliber players as defined by minutes played per match when considering the physical qualities mentioned previously, 3) and finally to assess the influence of physical qualities and playing position on high speed running performance throughout the course of a competitive season. Data from 57 Division I Women’s Collegiate soccer players from a single institution were used. The influence of playing position and caliber of play on physical qualities were assessed using both laboratory and field based testing assessments. It appears that attacking based players (forward, wide midfielder, and attacking midfielder) were faster compared to defensive based players (central defensive midfielder, central defender, and goalkeeper) when assessed during 20 m sprint assessments and change of direction ability assessments. The only variable to differentiate between caliber of play was the Yo-Yo Intermittent Recovery Test – Level 1 (YYIRT1), indicating that higher caliber players possess greater intermittent endurance capacity compared to lower caliber players. Playing position was the major contributor when assessing high speed running performance during competition, explaining almost 70% of the variance. These findings highlight the impact of tactical factors on physical performance during competition and the need for position based assessments to better identify relevant physical qualities with respect to playing position in Division I Women’s Collegiate Soccer players. Further research is needed with a wider range of players from various levels to determine if these findings exist across all levels or are unique to the institution used during these investigations

    Elevated temperature changes female costs and benefits of reproduction

    Get PDF
    Despite obvious benefits, reproduction also imposes severe costs on females. Such costs and benefits are highly sensitive to environmental factors. Rapidly changing conditions may thus disturb a finely poised balance between the two and pose a challenge to natural populations. A more complete understanding of reproduction and population fitness across different environments is, hence, crucial. In particular, sexual selection could either be beneficial or detrimental when conditions change abruptly. Here Tribolium castaneum females were subjected to mating treatments with or without sexual selection (virginity, monogamy, polyandry) replicated at standard versus elevated temperatures. We found a substantial survival cost of reproduction at the standard, but not at the elevated temperature. Reproductive success was similar across mating treatments at the standard temperature, but at elevated temperature we detected a significant benefit of polyandry compared to monogamy. These findings indicate that environmental heterogeneity can strongly influence the balance between costs and benefits when sexual selection is allowed to act. Furthermore, reproduction may be critically affected by changes in temperature with potentially profound consequences for population fitnes

    Experimental study of current ripples using medium silt

    Get PDF
    Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Earth and Planetary Science, 1982.MICROFICHE COPY AVAILABLE IN ARCHIVES AND LINDGRENBibliography: leaves 130-131.by Robert Anthony Grazer.M.S

    Environmental quality alters female costs and benefits of evolving under enforced monogamy

    Get PDF
    Background Currently many habitats suffer from quality loss due to environmental change. As a consequence, evolutionary trajectories might shift due to environmental effects and potentially increase extinction risk of resident populations. Nevertheless, environmental variation has rarely been incorporated in studies of sexual selection and sexual conflict, although local environments and individuals’ condition undoubtedly influence costs and benefits. Here, we utilise polyandrous and monogamous selection lines of flour beetles, which evolved in presence or absence of sexual selection for 39 generations. We specifically investigated effects of low vs. standard food quality (i.e. stressful vs. benign environments) on reproductive success of cross pairs between beetles from the contrasting female and male selection histories to assess gender effects driving fitness. Results We found a clear interaction of food quality, male selection history and female selection history. Monogamous females generally performed more poorly than polyandrous counterparts, but reproductive success was shaped by selection history of their mates and environmental quality. When monogamous females were paired with polyandrous males in the standard benign environment, females seemed to incur costs, possibly due to sexual conflict. In contrast, in the novel stressful environment, monogamous females profited from mating with polyandrous males, indicating benefits of sexual selection outweigh costs. Conclusions Our findings suggest that costs and benefits of sexually selected adaptations in both sexes can be profoundly altered by environmental quality. With regard to understanding possible impacts of environmental change, our results further show that the ecology of mating systems and associated selection pressures should be considered in greater detail

    REACTIVE STRENGTH INDEX-MODIFIED: A COMPARISON BETWEEN SIX U.S. COLLEGIATE ATHLETIC TEAMS

    Get PDF
    The purpose of this study was to compare reactive strength index-modified (RSImod) between six U.S. collegiate sport teams. One hundred six athletes performed maximum effort countermovement jumps during unloaded and loaded conditions. RSImod measures for each team were compared using one-way ANOVAs, and Bonferroni post hoc tests where warranted. Statistically significant differences in RSImod values existed between teams during both unloaded (< 1kg) and loaded (20kg) conditions. The greatest RSImod values during both conditions were produced by men’s soccer and followed in order by baseball, women’s volleyball, men’s tennis, women’s soccer, and women’s tennis. The data indicate that athletes from different sports possess different reactive strength characteristics

    A COMPARISON OF BASEBALL POSITIONAL DIFFERENCES WITH REACTIVE STRENGTH INDEX-MODIFIED

    Get PDF
    The purpose of this study was to examine positional differences amongst 29 baseball players using the Reactive Strength Index-modified (RSImod) values during unloaded and loaded countermovement jumps (CMJ). A secondary purpose was to determine the relationship between other jump performance characteristics and RSImod values. All athletes underwent CMJ testing and RSImod values were compared between pitchers and position players. The loaded condition CMJ produced statistically different RSImod values between the two groups. Scaled peak force was somewhat more strongly related to RSImod than rate of force development (RFD). The current study indicates that position players may possess higher reactive strength capabilities than pitchers and scaled peak force may be more important than RFD in determining reactive strength characteristics
    corecore