Numerical studies of collapsing interstellar clouds

Numerical simulation of the structure and evolution of interstellar clouds was conducted. Steps were taken toward an integrated treatment of the dynamical, thermal, and chemical processes entering model calculations, and a detailed study was made of radiative transfer in molecular lines to allow model predictions to be tested against empirical data. It is shown that the shapes of molecular lines are sensitive to details of the cloud structure and evolutionary state and are thus useful in inferring the cloud density, temperature, chemical composition, age, and initial conditions. The calculations have successfully reproduced and explained several observed cloud properties, including abundances of complex molecular species and the apparent depletion of CO in dense cores

Surf zone currents and influence on surfability

Surfing headlands are shallow and exposed coastal features that provide a specific form of breaking wave allowing a board-rider to ride on the unbroken wave face. The seabed shape and refraction of the waves in relation to depth contours provide the greatest influence on the quality of the surf break. The large scale and orientation of the Raglan headland allows only the low frequency swells to refract around the headland to create seven different surfing breaks. Each represents a compartmentalization of the shoreline along the headland. This creates variability in wave and current characteristics depending on the orientation and bathymetry at different locations. This provides not only potential access points through the surf-zone (ie: smaller currents), but greater surfability in a range of conditions that is not possible on small scale headlands. Headlands with surfing waves can be classified as mis-aligned sections of the coast, where the higher oblique angle of the breaking surf generates strong wave-driven currents. These currents are far greater than that found on coastlines in equilibrium with the dominant swell direction, where comparatively insignificant longshore drift is found. The strength and direction of wave-driven currents in the surf zone can influence the surfability of a break. At a surfing headland strong currents flowing downdrift along the shoreline make it difficult for a paddling surfer to get to the "take-off" location of the break, or maintain position in the line-up. In comparison currents flowing updrift along headlands makes getting "out the back" relatively easy, although surfers can be taken out to sea past the "take-off" point by a fast flowing current. Field experiments at Raglan, on the west coast of New Zealand have been conducted to measure current speed and direction during a large swell event. Observations of surfers attempting to paddle through the breaking-wave zone, confirms the strength of the wave-driven currents with surfers being swept rapidly down the headland. Results from the experiments at Raglan, have shown strong currents in the inshore breaking wave zone with burst-averaged velocities attaining 0.8 ms-1, and maximum bed orbital velocities of up to 2.0 ms-1. Interestingly, further offshore the currents have been found to flow in a re-circulating gyre back up the headland. Comparisons are made from observations of waves and currents found at other surfing headlands around the world. The effect that strong currents may have on the surfability of artificial surfing reefs needs to be considered in the design process, if the surfing amenity is to be maximised for large surf conditions

Effect of excess iron on oxidative dehydrogenation of 1-butene over a series of zinc ferrite catalysts

The influence of excess Fe3+ in ZnFe2O4 for the catalytic oxidative dehydrogenation of 1-butene to 1, 3-butadiene was investigated to try to clarify inconsistencies in the existing literature. A series of nanoscale zinc ferrite powders were produced with increasing Fe: Zn ratios. The materials were characterized by a range of techniques, which showed the presence of α-Fe2O3 as a distinct phase with an increasing excess of Fe3+ and SEM highlighted the increased presence of surface structures on the ferrites at higher Fe: Zn ratios. Reaction testing showed α-Fe2O3to be virtually inactive for the oxidative dehydrogenation of 1-butene. Results for the ferrite catalysts showed a significant decrease in both conversion and yield with an increasing excess of Fe3+. Therefore an excess of Fe3+ has a negative effect on catalytic activity and selectivity of zinc ferrite for the oxidative dehydrogenation of 1-butene, but acts as a promoter for competing hydrogenation and combustion side reactions

Physical Activity Belief Scales for Diabetes Risk: Development and Psychometric Testing

This article describes the development and psychometric evaluation of behavioral belief, normative belief, and control belief scales, derived from the theory of planned behavior to predict physical activity intentions of persons at risk for diabetes. In Study 1, belief statements from interviews were categorized, ranked, and evaluated for item construction. Content validity was established by 96. 1 % agreement among a five-member expert panel. In Study 2, items developed from the belief statements were administered to 106 adults at risk for diabetes. Psychometric analyses provided evidence of construct validity and reliability of the three scales. Internal consistency was sufficient (α = .76-.95), and test-retest evaluations indicated scale stability (r = .79- .91). Factor analyses and confirmatory factor analysis using structural equation modeling provided evidence that the items were appropriately grouped under each construct. Researchers and practitioners can use these measures to assess behavioral, normative, and control beliefs about physical activity among persons at risk for diabetes

Physiological health parameters among college students to promote chronic disease prevention and health promotion

This study aimed to provide physiologic health risk parameters by gender and age among college students enrolled in a U.S. Midwestern University to promote chronic disease prevention and ameliorate health. A total of 2615 college students between 18 and 25 years old were recruited annually using a series of cross-sectional designs during the spring semester over an 8-year period. Physiologic parameters measured included body mass index (BMI), percentage body fat (%BF), blood serum cholesterol (BSC), and systolic (SBP) and diastolic (DBP) blood pressure. These measures were compared to data from NHANES to identify differences in physiologic parameters among 18-25 year olds in the general versus college-enrolled population. A quantitative instrument assessed health behaviors related to physical activity, diet, and licit drug use. Results suggest that average physiologic parameters from18 to 25 year olds enrolled in college were significantly different from parameters of 18-25 year olds in the general population. Generally, men reported higher percentiles for BMI, SBP, and DBP than women, but lower %BF and BSC percentiles than women at each age. SBP and DBP significantly increased with age and alcohol use. Students in the lowest (5th) and highest percentiles (95th and 75th), for most age groups, demonstrated DBP, BMI, and %BF levels potentially problematic for health and future development of chronic disease based on percentiles generated for their peer group. Newly identified physiologic parameters may be useful to practitioners serving college students 18–25 years old from similar institutions in determining whether behavior change or treatment interventions are appropriate

Advice from the Bench (Memo): Clerk Influence on Supreme Court Oral Arguments

Scholars of the U.S. Supreme Court have long debated the role, and possible influence, of clerks on the decisions their Justices make. In this Paper, we take a novel approach to analyze this phenomenon. We utilize pre-oral argument bench memos sent to Justice Harry A. Blackmun from his clerks. Specifically, we use these memos to determine whether Justice Blackmun asked questions of counsel that were recommended by his clerks in the memos. Our data indicate Justice Blackmun often followed his clerks’ advice. Accordingly, we provide another important link to demonstrate Supreme Court clerks can and do affect how their Justices evaluate cases

Ionic relationships of enteromorpha intestinnalis l.

The green alga Enteromorpha intestinalis (L. Link) has been observed to grow over a wide range of salinities, from 0.1% to 100% sea water, the optimum grown range being between about 30% and 70% sea water. The range of salinities in which the alga occurs is unusually wide for a marine alga, and an investigation of its ionic relationships was therefore undertaken. Measurements have therefore been made of concentrations of the major ions (Na, K and C1) in the plant cells and in sea water together with measurements of cell membrane potential and ion flux rates. Measurements of the electrical potential difference across the plasmalemma and the influx and efflux of each ion indicate that K and C1 are actively imported and Na actively exported over the whole salinity range. Estimates of cell permeability to the passive diffusive fluxes of these three ions alone have been used to explain the origin of the cell membrane potentials over the range of salinities. Tracer ion kinetics are taken as showing that the tonoplast is more permeable than the plasmalemma to each ion. The ion fluxes against their electro-chemical potential gradients consist of at least two components, one active, the other passive, the passive component has been calculated, for each ion, from the Goldman flux equations. The remaining putative active flux components have been compared with the measured active fluxes and the interlinkages of the latter have been determined. None of the active transport mechanisms for each ion appear to be electrogenic neither do they appear to be 1:1 coupled exchange transport as all the active fluxes are affected by the lowering of temperature and by certain metabolic inhibitors. Use of such inhibitors has enabled division of the fluxes into their component parts. A component of the active K influx and a component of the active Na efflux are linked through a ouabain sensitive transport mechanism. A further component of the active K influx is ouabain insensitive but is dependent upon c1, and further, a part of this C1 dependent K influx requires light while the remainder does not. the active C1 influx has a light dependent component, part of which appears to require both K and Na specifically, the remainder being cation independent. This interlinkage of active fluxes appears to be maintained at all dilutions of sea water as the influxes and effluxes of each ion remain in constant proportion to one another and to the fluxes of other ions over the whole salinity range investigated. The ratio of internal concentration to external concentration, for each ion, increases with increasing dilution although the rations of the internal ions to one another remain reasonably constant. When plants are maintained in solutions of varying sodium to potassium ratio the internal sodium to potassium ratio differs markedly from that found in plants growing in sea water; the plants in such experimental solutions, however, appear to be able to tolerate these internal ionic rations and have remained healthy in such solutions for at least seven days. The majority of plants require a constant internal ionic environment for efficient functioning of their metabolism. This does not appear to be the case with D. intestinalis which may account for its ability to inhabit regions of widely varying salinity

Civil Society and the Promotion of Human Security : Achievements, Limits, and Prospects

In the years immediately before and after the 1998 Lysøen Declaration, a striking feature of the initiatives associated with the human security agenda was the prominent role of civil society coalitions, which was widely regarded as indispensible to the signal successes of this period. However, the dramatic breakthroughs of this new diplomacy were the products of a propitious conjuncture of conditions that contained the seeds of their subsequent loss of momentum. Yet the human security work of civil society organizations (CSOs) continues, in less prominent but still important ways, to be woven into the fabric of the more cosmopolitan practices promoted by the agenda. In the meantime, their setbacks contain important lessons—both for CSOs and for the policymakers inclined to collaborate with them

Dietary Intake and Energy Expenditure of Female Collegiate Swimmers During Decreased Training Prior to Competition

Swimmers, like all athletes, require a well-balanced diet with adequate energy intake for normal daily activities and the demands of training and competition. Investigators have typically studied nutritional status of athletes during heavy or peak training (1), (2). These studies generally show low levels of energy intake relative to expenditure, and carbohydrate intake also well below recommendations. However, several studies of the effects of exercise on energy intake have shown that as exercise energy expenditure increases or decreases, dietary intake tends to remain the same (3), (4), (5). Because training volume varies with the competitive season, it is important to investigate dietary intake at different levels of training. One period of training during which nutritional intake has not been studied is during taper, a period of decreased training before an athletic event to improve mental and physical readiness for competition (6). An important issue during this period is whether the discrepancy between energy intake and expenditure previously reported during heavy training is maintained during a period of reduced training. Another consideration is the number of reduced-fat food products consumed by female athletes. (In recent years, there has been an overwhelming increase in the availability of low-fat and fat-free food products.) Increased use of these foods may contribute to the increased carbohydrate intake observed in some recent studies of female athletes (7), (8), (9), which contrasts with earlier studies suggesting that carbohydrate intakes of female endurance athletes are 14% to 24% lower than recommended (1)