Numerical implementation of some reweighted path integral methods

The reweighted random series techniques provide finite-dimensional approximations to the quantum density matrix of a physical system that have fast asymptotic convergence. We study two special reweighted techniques that are based upon the Levy-Ciesielski and Wiener-Fourier series, respectively. In agreement with the theoretical predictions, we demonstrate by numerical examples that the asymptotic convergence of the two reweighted methods is cubic for smooth enough potentials. For each reweighted technique, we propose some minimalist quadrature techniques for the computation of the path averages. These quadrature techniques are designed to preserve the asymptotic convergence of the original methods.Comment: 15 pages, 10 figures, submitted to JC

Participation in college sports and protection from sexual victimization

Some sociologists have argued that sport is a male-dominated institution and sexist culture in which female athletes experience various forms of discrimination, including sexual harassment from coaches and male athletes. Some research does indicate that female athletes suffer higher rates of sexual victimization from authority figures in sport than their nonathletic counterparts in education and the workplace. In contrast, researchers have also speculated that athletic participation can protect female athletes from sexual victimization through a variety of social-psychological mechanisms such as team membership, physical strength, and self-confidence. This paper reports on the first descriptive analysis to test the “sport protection hypothesis” among both female and male athletes, using cross-tabulation secondary analyses of data from the National College Health Risk Behavior Survey, conducted in 1995 by the U.S. Centers for Disease Control and Prevention (N=4814). USA college students of traditional undergraduate age (aged 18-24) were included in the sample (N=2903). Some limited support for the protection hypothesis was found, and student athletes were significantly less likely to report sexual victimization during their late high school and early college years than their nonathletic counterparts. A gender gap in the pattern of sexual victimization also appeared between males and females across all student age groups, with females experiencing more sexual victimization than males. However, no significant gender gap was found among athletes. The results are discussed in relation to previous studies of campus athletes and to college prevention policy

Taming the rugged landscape: production, reordering, and stabilization of selected cluster inherent structures in the X_(13-n)Y_n system

We present studies of the potential energy landscape of selected binary Lennard-Jones thirteen atom clusters. The effect of adding selected impurity atoms to a homogeneous cluster is explored. We analyze the energy landscapes of the studied systems using disconnectivity graphs. The required inherent structures and transition states for the construction of disconnectivity graphs are found by combination of conjugate gradient and eigenvector-following methods. We show that it is possible to controllably induce new structures as well as reorder and stabilize existing structures that are characteristic of higher-lying minima. Moreover, it is shown that the selected structures can have experimentally relevant lifetimes.Comment: 12 pages, 14 figures, submitted to J. Chem. Phys. Reasons for replacing a paper: figures 2, 3, 7 and 11 did not show up correctl

Energy estimators for random series path-integral methods

We perform a thorough analysis on the choice of estimators for random series path integral methods. In particular, we show that both the thermodynamic (T-method) and the direct (H-method) energy estimators have finite variances and are straightforward to implement. It is demonstrated that the agreement between the T-method and the H-method estimators provides an important consistency check on the quality of the path integral simulations. We illustrate the behavior of the various estimators by computing the total, kinetic, and potential energies of a molecular hydrogen cluster using three different path integral techniques. Statistical tests are employed to validate the sampling strategy adopted as well as to measure the performance of the parallel random number generator utilized in the Monte Carlo simulation. Some issues raised by previous simulations of the hydrogen cluster are clarified.Comment: 15 pages, 1 figure, 3 table

Heat capacity estimators for random series path-integral methods by finite-difference schemes

Previous heat capacity estimators used in path integral simulations either have large variances that grow to infinity with the number of path variables or require the evaluation of first and second order derivatives of the potential. In the present paper, we show that the evaluation of the total energy by the T-method estimator and of the heat capacity by the TT-method estimator can be implemented by a finite difference scheme in a stable fashion. As such, the variances of the resulting estimators are finite and the evaluation of the estimators requires the potential function only. By comparison with the task of computing the partition function, the evaluation of the estimators requires k + 1 times more calls to the potential, where k is the order of the difference scheme employed. Quantum Monte Carlo simulations for the Ne_13 cluster demonstrate that a second order central-difference scheme should suffice for most applications.Comment: 11 pages, 4 figure

Differential in University Academic Performance of Students from Public and Private Secondary Schools Studying in Federal University Dutsin-Ma

There exists a serious controversy over the University performance of students attending public and private secondary schools. This study aimed to assess the differential in university academic performance of students from public and private secondary schools studying in Federal University Dutsin-Ma. The research design of this study is an ex post facto research design. The population is made up of all 300 level students of Federal University Dutsin-Ma, Katsina, Katsina State during the 2020/2021 academic session. The sample size was 183 (Male 120 & Female 63) students, simple random sampling technique was used to select sample from each programme in Science Education Department, Federal University Dutsin-Ma, Katsina State. The students’ cumulative grade point average (CGPA) at the end of the 300 level 2020/2021 academic session was collected. The data collected were analyzed using t-test inferential statistic. Results obtained showed that there is no difference between university academic performance of private and public secondary school students in Federal university Dutsin-Ma., and recommended that, parents could take their children to any school type irrespective of public or private secondary school

Aspects of Thule Culture Adaptations in Southern Baffin Island

An archaeological sequence of Neo-Eskimo occupations, based upon excavations of eight Thule winter houses near Lake Harbour, Baffin Island, is outlined, beginning around A.D. 1100 and extending into the present century. Relationships between past climatic events, local environmental characteristics, and the organization of Neo-Eskimo subsistence-settlement systems are traced throughout this period of time, based on analysis of artifactual, faunal, and midden deposit data. A rescheduling of procurement systems, coupled with a shift in the emphasis of fall/winter settlement options, is seen in response to climatic/ecological changes, commencing after A.D. 1250, which affected the accessibility of bowhead whales, ringed seal, and caribou. It is suggested that flexibility in the organization of domestic units and demographic arrangements was an important cultural mechanism permitting Thule and recent Inuit populations to respond effectively to changes in their biophysical environments

Environmental and Public Health Perspective of the Prevalence of Intestinal Helminths Infection of Cattle in Gubi and Galambi Ranches in Bauchi, Nigeria

Faecal samples were collected from cattle in Gubi and Galambi cattle ranches and examined for eggs of intestinal helminths. The ages of the cattle ranged from 1-10 years and were grouped into two - 1-4 years and 5-10 years representing younger and older cattle respectively. A total number of 600 cattle (300 from each farm) were examined for intestinal parasites out of which 355 cattle were found to be infected in the two cattle ranches. Out of the 355 infected cattle, 50.99% were from Galambi, while Gubi had slightly lower cases of 49.01%. Out of the 10 helminths species identified in the two cattle ranches the most prevalent was Oesophagostomum radiatum. Female cattle were more infected (60.66%) in Gubi than their male counterparts in which 55.32% infection rate was recorded. Similar trend was also observed in Galambi where the rate of infection recorded in the female (62.00%) was higher than 58.62% recorded in the male cattle. Among the younger cattle aged 1-4 years, 29.36% were infected in Gubi while 26.00% of the same age group were harbouring the parasites in Galambi. It is recommended among others that penn should not be overstocked and cattle farmers should be educated on the importance of environmental sanitation and hygiene in cattle ranches management. Key words: Intestinal, Helminths, Cattle Ranches, Bauch