1,438 research outputs found
Geologic applications of thermal-inertia mapping from satellite
In the Powder River Basin, Wyo., narrow geologic units having thermal inertias which contrast with their surroundings can be discriminated in optimal images. A few subtle thermal inertia anomalies coincide with areas of helium leakage believed to be associated with deep oil and gas concentrations. The most important results involved delineation of tectonic framework elements some of which were not previously recognized. Thermal and thermal inertia images also permit mapping of geomorphic textural domains. A thermal lineament appears to reveal a basement discontinuity which involves the Homestake Mine in the Black Hill, a zone of Tertiary igneous activity and facies control in oil producing horizons. Applications of these data to the Cabeza Prieta, Ariz., area illustrate their potential for igneous rock type discrimination. Extension to Yellowstone National Park resulted in the detection of additional structural information but surface hydrothermal features could not be distinguished with any confidence. A thermal inertia mapping algorithm, a fast and accurate image registration technique, and an efficient topographic slope and elevation correction method were developed
Pressure Calculation in Polar and Charged Systems using Ewald Summation: Results for the Extended Simple Point Charge Model of Water
Ewald summation and physically equivalent methods such as particle-mesh
Ewald, kubic-harmonic expansions, or Lekner sums are commonly used to calculate
long-range electrostatic interactions in computer simulations of polar and
charged substances. The calculation of pressures in such systems is
investigated. We find that the virial and thermodynamic pressures differ
because of the explicit volume dependence of the effective, resummed Ewald
potential. The thermodynamic pressure, obtained from the volume derivative of
the Helmholtz free energy, can be expressed easily for both ionic and rigid
molecular systems. For a system of rigid molecules, the electrostatic energy
and the forces at the atom positions are required, both of which are readily
available in molecular dynamics codes. We then calculate the virial and
thermodynamic pressures for the extended simple point charge (SPC/E) water
model at standard conditions. We find that the thermodynamic pressure exhibits
considerably less system size dependence than the virial pressure. From an
analysis of the cross correlation between the virial and thermodynamic
pressure, we conclude that the thermodynamic pressure should be used to drive
volume fluctuations in constant-pressure simulations.Comment: RevTeX, 19 pages, 2 EPS figures; in press: Journal of Chemical
Physics, 15-August-199
Comparing injunctive marijuana use norms of salient reference groups among college student marijuana users and nonusers
Marijuana is the most commonly used illicit drug among college students and has the potential for various negative outcomes. Perceptions of what constitutes typical approval/acceptability of a reference group (i.e. injunctive social norms) have been shown to have strong utility as predictors of health-risk behaviors in the college context, yet this construct remains significantly understudied for marijuana use despite its potential for use in social norms-based interventions. The current research evaluated individuals’ marijuana approval level and their perceptions of others’ marijuana approval level (i.e. injunctive norms) for various reference groups (typical student on campus, one’s close friends, one’s parents) as a function of individual user status (abstainers, experimenters, occasional users, regular users). A diverse sample of 3553 college students from two universities completed an online survey. Among all user status groups, individual approval yielded mean scores paralleling that of perceived close friends’ approval and all groups were relatively uniform in their perception of typical students’ approval. Higher levels of marijuana use tended to produce higher endorsements of individual approval, perceived close friends’ approval, and perceived parental approval. Among occasional and regular users, there were no differences between one’s own approval level for use and the perceptions of close friends’ approval, nor did they think the typical student was more approving than themselves. Abstainers and experimenters, however, perceived typical students and close friends to have more permissive attitudes than themselves. Implications and future directions for research regarding the role of injunctive marijuana use norms in the development of social norms intervention are discussed
“This would be better drunk”: Alcohol expectancies become more positive while drinking in the college social environment
The current study examined whether drinking and/or presence in the college social environment led to augmented positive alcohol expectancies among college students (N = 225). Participants were approached during popular drinking nights as they exited events at which alcohol was consumed or in front of their residence as they returned home. Participants completed a brief questionnaire that included an assessment of demographics, breath alcohol concentration (BrAC), and positive expectancies. Within 48 hours of baseline assessment, participants received via email a follow-up survey that re-assessed positive expectancies while sober. Positive sexual expectancies were more strongly endorsed while drinking in the college social environment for both males and females, while males also reported heightened liquid courage expectancies. In addition, positive expectancies were more strongly endorsed at higher doses of alcohol for males but not females. These findings suggest that interventions which seek to prevent alcohol abuse by targeting alcohol expectancies may wish to challenge positive expectancies in naturalistic college social settings
Inconsistency in Fermi's probability of the quantum states
We point out an important hidden inconsistency in Fermi's probability of the
quantum states that engendered inconsistent/inaccurate equations-of-state
extensively used in the literature to model nonideal plasma systems. The
importance of this amendment goes beyond rectifying our comprehension and
foundation of an important physical problem to influencing contemporary
research results.Comment: Accepted for Publicatio
Self-Consciousness Moderates the Relationship between Perceived Norms and Drinking in College Students
The current research examines whether self-consciousness subscales have prognostic value in the relationship between perceived norms and drinking and if that differs among college men and women. Results indicate that self-consciousness moderates gender differences in the relationship between perceived social norms and drinking. A strong positive relationship was found between perceived norms (descriptive and injunctive) and drinking for men relative to women and this was more pronounced among individuals who were lower in public self-consciousness. Similarly, the relationship between perceived injunctive norms and drinking was significantly stronger among men than women and this was more pronounced among individuals who were higher in private self-consciousness or social anxiety. These results highlight the important influence of social factors in salient peer reference groups. This is promising information for future research attempting to identify useful indicators of candidates who would most benefit from social norms interventions. This also underscores the relevance of future norms based interventions using self-consciousness as a potential moderator of intervention efficacy
The prognostic power of normative influences among NCAA student-athletes
This study evaluated the predictive power of perceived descriptive and injunctive norms on intercollegiate student-athlete alcohol consumption and attitudes toward drinking-related behaviors. The sample consisted of 594 NCAA student-athletes from two geographically opposite sites. Norms variables utilized a school and gender-specific athletic peer reference group. Results indicate that respondents reported greater perceived injunctive norms than actual attitudes, and greater perceived descriptive norms than actual alcohol use. Further, after accounting for demographics and alcohol motivations, perceived injunctive norms were the strongest predictors of athletes\u27 attitudes with the final model explaining 54% of the variance. Similarly, perceived descriptive norms were among the strongest predictors of alcohol use with the final model explaining 69% of the variance. Future research may want to use both of these perceived norms constructs to create a more salient and targeted social norms intervention aimed at reducing risky behavior and permissive alcohol-related attitudes among this population. Utilizing this strong peer reference group as well as targeting both injunctive and descriptive norms may increase the power and saturation of prevention and intervention strategies
Effect of Reclamation Technique on Mammal Communitites Inhabiting Wetlands on Mined Lands in East-Central Ohio
Author Institution: Department of Forestry, University of Kentucky; Wildlife Technology Program and Department of Biology, The Pennsylvania State UniversityMammal communities were studied from May through August, 1988 to 1990, at four wetland sites in Coshocton and Muskingum counties, OH. Sites represented varying degrees of disturbance from mining activity and subsequent reclamation techniques, including a wetland constructed to treat mine water drainage. Each site was composed of a series of three cattail (Typba latifolid) cells for a balanced experimental design. Mammals were inventoried with snap trap removal grids and midday surveys for signs of activity. Mammal diversity and richness was highest at the constructed wetland and lowest at the site established with traditional reclamation procedures. Predictable patterns of land use disturbance for species presence/absence were observed with some alpha diversity (habitat specific) species being absent (i.e., tree squirrels) and gamma diversity (wide-ranging) species such as mustelids occurring rarely. Beta diversity species (habitat generalists) like woodchucks (Marmota monax) and white-tailed deer (Odocoileus virginianus) were common at all sites. The white-footed mouse (Peromyscus leucopus) was the small mammal captured most frequently, being the most abundant small mammal at the constructed wetland and the undisturbed site, with meadow voles (Microtus pennsylvanicus) most prevalent at the remaining sites. These results suggest that a wetland constructed for the treatment of mine water drainage can provide secondary benefits as habitat for a variety of mammal species
Are they all the same? An exploratory, categorical analysis of drinking game types
Drinking games have become a ubiquitous part of the college student drinking culture and are associated with drinking to intoxication and increased alcohol consequences. Contemporary research commonly considers drinking games holistically, with little to no consideration to the different drinking game types. The current study describes the creation of a novel DG categorization scheme and reports differences between DG categories. Participants were 3421 college students (58% female) who completed online surveys. Based on participant responses, 100 distinct drinking games were identified and defined. Two student focus groups were conducted in which drinking game definitions and rules were verified by students. Drinking games were then categorized into five mutually exclusive categories: Targeted and Skill games, Communal games, Chance games, Extreme Consumption games, and Even Competition games. Finally, the frequency of games played in each category and typical player profiles were reported. Differences in peak drinks and frequency of specific alcohol consequences were documented according to game categories. The findings provide a novel drinking game categorization scheme and an exploratory analysis of basic differences between game categories
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