Authors of the article assert that public speaking, especially in a foreign language, is associated with increased anxiety. The authors found that VR technology had a positive effect on practicing public speaking in a foreign language, the research findings have practical implications for professionals and curriculum designers in various domains where public speaking skills are essential.

We examine the mechanics of the send and receive mechanism of MPI and in particular how we can implement message passing in a robust way so that our performance is not significantly affected by changes to the MPI system. This leads us to using the Isend/Irecv protocol which will entail sometimes significant algorithmic changes. We discuss this within the context of two different algorithms for sparse Gaussian elimination that we have parallelized. One is a multifrontal solver called MUMPS, the other is a supernodal solver called SuperLU. Both algorithms are difficult to parallelize on distributed memory machines. Our initial strategies were based on simple MPI point-to-point communication primitives. With such approaches, the parallel performance of both codes are very sensitive to the MPI implementation, the way MPI internal buffers are used in particular. We then modified our codes to use more sophisticated nonblocking versions of MPI communication. This significantly improved the performance robustness (independent of the MPI buffering mechanism) and scalability, but at the cost of increased code complexity.

Before small-angle neutron scattering (SANS), chain conformation studies were limited to light and small angle x-ray scattering techniques, usually in dilute solution. SANS from blends of normal and labeled molecules could give direct information on chain conformation in bulk polymers. Water-soluble polymers may be examined in H/sub 2/O/D/sub 2/O mixtures using contrast variation methods to provide further information on polymer structure. This paper reviews some of the information provided by this technique using examples of experiments performed at the National Center for Small-Angle Scattering Research (NCSASR).

Although it has been recognized for some time that the rate of reactive uptake of gases in cloudwater can depend on the value of the mass-accommodation coefficient (..cap alpha..) describing interfacial mass transport (MT), definitive evaluation of such rates is only now becoming possible with the availability of measurements of ..cap alpha.. for gases of atmospheric interest at air-water interfaces. Examination of MT limitation to the rate of in-cloud aqueous-phase oxidation of SO/sub 2/ by O/sub 3/ and H/sub 2/O/sub 2/ shows that despite the low value of ..cap alpha../sub O3/ (5 /times/ 10/sup /minus/4/), interfacial MT of this species is not limiting under essentially all conditions of interest; the high values of ..cap alpha.. for SO/sub 2/ (greater than or equal to 0.2) and H/sub 2/O/sub 2/ (greater than or equal to 0.08) indicate no interfacial MT limitation for these species also. Although gas- and aqueous-phase MT can be limiting under certain extremes of conditions, treating the system as under chemical kinetic control is generally an excellent approximation. Interfacial MT limitation also is found not to hinder the rate of H/sub 2/O/sub 2/ formation by aqueous-phase disproportionation of HO/sub 2/. Finally, the rapid uptake of N/sub 2/O/sub 5/ by …

Landscape pattern can be modelled on a grid with polygons constructed from cells that share edges. Although this model only allows connections in four directions, programming is convenient because both coordinates and attributes take discrete integer values. A typical raster land-cover data set is a multimegabyte matrix of byte values derived by classification of images or gridding of maps. Each matrix may have thousands of raster polygons (patches), many of them islands inside other larger patches. These data sets have complex topology that can overwhelm vector geographic information systems. The goal is to develop tools to quantify change in the landscape structure in terms of the shape and spatial distribution of patches. Three milestones toward this goal are (1) creating polygon topology on a grid, (2) visualizing patches, and (3) analyzing shape and pattern. An efficient algorithm has been developed to locate patches, measure area and perimeter, and establish patch topology. A powerful visualization system with an extensible programming language is used to write procedures to display images and perform analysis.

This article compares Bayesian, Robust maximum likelihood, and asymptotically generalized least squares interval estimates of factor correlations in ordinal confirmatory factor analysis models for small sample data.

To manage forests as ecosystems, the many values they hold for different users must be recognized, and they must be used so that those assets are not destroyed. Important ecosystem features of forests include nutrient cycling, habitat, succession, and water quality. Over time, the ways in which humans value forests have changed as forest uses have altered and as forests have declined in size and quality. Both ecosystem science and forest ecology have developed approaches that are useful to manage forests to retain their value. A historical perspective shows how changes in ecology, legislation, and technology have resulted in modern forest-management practices. However, current forest practices are still a decade or so behind current ecosystem science. Ecologists have done a good job of transferring their theories and approaches to the forest manager classroom but have done a poor job of translating these concepts into practice. Thus, the future for ecosystem management requires a closer linkage between ecologists and other disciplines. For example, the changing ways in which humans value forests are the primary determinant of forest-management policies. Therefore, if ecologists are to understand how ecosystem science can influence these policies, they must work closely with social scientists trained to assess …

Article presenting a curriculum mapping study of noncore course offerings in political science curricula by an early-career librarian. It combines syllabi study and curriculum mapping methods to analyze the language of student learning objectives (SLOs) from course syllabi and to integrate SLOs with threshold concepts from the ACRL Framework for Information Literacy for Higher Education and the AAC&U Information Literacy VALUE Rubric. The methods produce two sample sets: one of core concept representation and the other of additional observances for syllabi improvements. Results analyze the frequency and percentage distributions of threshold concepts in SLOs. The author outlines strategies for engaging faculty in information literacy and suggests how librarians and faculty might inform information literacy teaching in the department.

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In a nuclear reactor, tubes are pressurized from interior by coolant, while externally no pressure is applied on them. The pressure that causes any of the tubes to burst is random and has certain distribution. By using the presently available data from stress-strain experiment, mathematical procedure for finding the distribution form of the ultimate stress is made and is justified theoretically and empirically. The distribution function obtained is important in analyzing the problem of loss of coolant in the reactor.

This article studies special infinite iterated function systems derived from complex continued fraction expansions with restricted entries.

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Article discussing research on L- and M-shell x-ray production cross sections of Nd, Gd, Ho, Yb, Au, and Pb by 25-MeV carbon and 32-MeV oxygen ions.

This article discusses electron localization in a two-channel tight-binding model with correlated disorder.

This report documents maximum scan speeds to maintain the minimum detectable activity (MDA) of Hanford contamination survey instruments at one times or three times the total contamination value. Scan speeds are interpolated from empirically derived minimum detectable count rates (MDCR) for beta/gamma and alpha contamination survey instruments. The MDCRs were measured using distributed contamination sources. The instruments tested were a 15.5-cm{sup 2} pancake Geiger-Mueller (GM) detector, a 100-cm{sup 2} gas proportional detector, and a 50-cm{sup 2} Hanford portable alpha meter (PAM). The MDCR for a scanning survey is highly dependent on survey technique. Scanning surveys at Hanford are performed by scanning the surface with the probe held a maximum of 6 mm (1/4 in.) away from the surface. If an increase above background is noted, the technician pauses for 5 to 10 seconds. For this evaluation, any counts detected with an alpha survey instrument are treated as an increase above background (assumed to be 0 cpm). During the 5- to 10-second count, if additional counts are detected, the area is assumed to be contaminated. Methods for calculating the MDA were previously developed and reported in Goles et al. (1991). This report also provides MDAs for a 5-second static count with …

The author gives a detailed introduction into the theoretical formalism for {epsilon}{prime}/{epsilon}, which measures direct CP-violation in K {yields} {pi}{pi} decays. The current status of hadronic matrix elements and the strange quark mass is discussed. Several possible explanations of the unexpectedly high experimental results for {epsilon}{prime}/{epsilon} are pointed out: A small strange quark mass, an enhancement of the hadronic parameter B{sub 6}{sup (1/2)} from the {sigma} resonance, an underestimate of isospin breaking and possible new physics contributions in the {bar s}dZ-vertex and the {bar s}d-gluon-vertex.

Article discusses how the child-caregiver relationship is the foundation for which intervention occurs. The purpose of this study is to explore how researchers and clinicians might collect direct data on IOH to assess the acceptability of an intervention.

The National Institute of Justice has tasked their Satellite Facility at Sandia National Laboratories and their Southeast Regional Technology Center in Charleston, South Carolina to devise new procedures and tools for helping correctional facilities to assess their security vulnerabilities. Thus, a team is visiting selected correctional facilities and performing vulnerability assessments. A vulnerability assessment helps to identi~ the easiest paths for inmate escape, for introduction of contraband such as drugs or weapons, for unexpected intrusion fi-om outside of the facility, and for the perpetration of violent acts on other inmates and correctional employees, In addition, the vulnerability assessment helps to quantify the security risks for the facility. From these initial assessments will come better procedures for performing vulnerability assessments in general at other correctional facilities, as well as the development of tools to assist with the performance of such vulnerability assessments.

Some data sets dealing with the hazards of low-level radiation are discussed. It is concluded that none of these reports, individually or collectively, changes appreciably or even significantly the evaluations of possible low-level radiation effects that have been made by several authoritative national and international groups. (ACR)

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Hydrocodes or more accurately, shock physics analysis packages, have been widely used in the US Department of Energy (DOE) laboratories and elsewhere around the world for over 30 years. Initial applications included weapons effects studies where the pressure levels were high enough to disregard the material strength, hence the term hydrocode. Over the last 30 years, Sandia has worked extensively to develop and apply advanced hydrocodes to armor/anti-armor interactions, warhead design, high explosive initiation, and nuclear weapon safety issues. The needs of the DOE have changed over the last 30 years, especially over the last decade. A much stronger emphasis is currently placed on the details of material deformation and high explosive initiation phenomena. The hydrocodes of 30 years ago have now evolved into sophisticated analysis tools that can replace testing in some situations and complement it in all situations. A brief history of the development of hydrocodes in the US will be given. The author also discusses and compares the four principal methods in use today for the solution of the conservation equations of mass, momentum, and energy for shock physics applications. The techniques discussed are the Eulerian methods currently employed by the Sandia multi-dimensional shock physics analysis package …

This article contains an analysis of 16 microstatellite loci from 300 Greater Sage-Grouse individuals to assess genetic structure among populations in Wyoming and southeast Montana.

Article reports that the massive amount of available neurodata suggests the existence of a mathematical backbone underlying neuronal oscillatory activities. The authors assert that the Monge’s theorem might contribute to our visual ability of depth perception and the brain connectome can be tackled in terms of tunnelling nanotubes.

Article describes how taxonomic profiling of ancient metagenomic samples is challenging due to the accumulation of specific damage patterns on DNA over time. The authors performed a comprehensive evaluation on simulated metagenomes representing human dental calculus microbiome, with the level of DNA damage successively raised to mimic modern to ancient metagenomes.