Assessing the costs and benefits of an oral vaccine for raccoon rabies: a possible model.

Any cost-benefit analysis of the use of an oral vaccine to control raccoon rabies should include calculating both costs and benefits in terms of $/unit area. Further, cost savings must be adjusted to match the stages of an epizootic: pre-epizootic, epizootic, and post-epizootic. A generic model, which can be adapted to different sites, illustrates the use of threshold analysis to link distribution costs, cost savings, bait density, and vaccine price. Initial results indicate the need to lower the cost of the vaccine, continue research to determine optimal bait densities, and examine distribution plans that do not require continued protection of areas in which raccoon rabies was eliminated through previous vaccination programs

Scalable designs for quantum computing with rare-earth-ion-doped crystals

Due to inhomogeneous broadening, the absorption lines of rare-earth-ion dopands in crystals are many order of magnitudes wider than the homogeneous linewidths. Several ways have been proposed to use ions with different inhomogeneous shifts as qubit registers, and to perform gate operations between such registers by means of the static dipole coupling between the ions. In this paper we show that in order to implement high-fidelity quantum gate operations by means of the static dipole interaction, we require the participating ions to be strongly coupled, and that the density of such strongly coupled registers in general scales poorly with register size. Although this is critical to previous proposals which rely on a high density of functional registers, we describe architectures and preparation strategies that will allow scalable quantum computers based on rare-earth-ion doped crystals.Comment: Submitted to Phys. Rev.

Dynamic wetting with two competing adsorbates

We study the dynamic properties of a model for wetting with two competing adsorbates on a planar substrate. The two species of particles have identical properties and repel each other. Starting with a flat interface one observes the formation of homogeneous droplets of the respective type separated by nonwet regions where the interface remains pinned. The wet phase is characterized by slow coarsening of competing droplets. Moreover, in 2+1 dimensions an additional line of continuous phase transition emerges in the bound phase, which separates an unordered phase from an ordered one. The symmetry under interchange of the particle types is spontaneously broken in this region and finite systems exhibit two metastable states, each dominated by one of the species. The critical properties of this transition are analyzed by numeric simulations.Comment: 11 pages, 12 figures, final version published in PR

Indentation and self-healing mechanisms of a self-assembled monolayer:a combined experimental and modeling study

A combination of in situ vibrational sum-frequency generation (SFG) spectroscopy and molecular-dynamics (MD) simulations has allowed us to study the effects of indentation of self-assembled octadecylphosphonic acid (ODPA) monolayers on α-Al2O3(0001). Stress-induced changes in the vibrational signatures of C–H stretching vibrations in SFG spectra and the results of MD simulations provide clear evidence for an increase in gauche-defect density in the monolayer as a response to indentation. A stress-dependent analysis indicates that the defect density reaches saturation at approximately 155 MPa. After stress is released, the MD simulations show an almost instantaneous healing of pressure-induced defects in good agreement with experimental results. The lateral extent of the contact areas was studied with colocalized SFG spectroscopy and compared to theoretical predictions for pressure gradients from Hertzian contact theory. SFG experiments reveal a gradual increase in gauche-defect density with pressure before saturation close to the contact center. Furthermore, our MD simulations show a spatial anisotropy of pressure-induced effects within ODPA domains: molecules tilted in the direction of the pressure gradient increase in tilt angle while those on the opposite side form gauche-defects

Risk factors for vulnerable youth in urban townships in South Africa: the potential contribution of reactive attachment disorder

Reactive attachment disorder (RAD) is a psychiatric disorder developing in early or middle childhood as a consequence of significant failures in the caregiving environment. RAD results in children failing to relate socially, either by exhibiting markedly inhibited behaviour or by indiscriminate social behaviour and is associated with significant socio-behavioural problems in the longer term. This study examined RAD in South Africa, a setting with high environmental risks. We recruited a sub-sample of 40 10-year-old children from a cohort enrolled during pregnancy for whom early attachment status was known. Children were purposefully selected to represent the four attachment categories using the data available on the strange situation procedure (SSP) at 18 months. The Manchester Child Attachment Story Task (MCAST) assessed current attachment and RAD was diagnosed using a standardised assessment package. A high proportion of the children (5/40% or 12.5%) fulfilled diagnostic criteria for RAD; all were boys and were displaying the disinhibited type. SSP classification at 18 months was not significantly associated with RAD symptoms at age of 10 years, while current MCAST classifications were. This suggests that children in this sample are at much higher risk of RAD than in high-income populations, and despite a fairly typical attachment distribution in this population at 18 months, RAD was evidenced in later childhood and associated with current attachment disorganisation. The strengths of this research include its longitudinal nature and use of diagnostic assessments. Given increasing evidence that RAD is relatively stable over time and introduces longer term socio-behavioural risks; the high rate of RAD in this sample (12.5%) highlights potential developmental threats to children in low- and middle-income countries (LMICs). Our results should be interpreted with caution given sample size and risk of selection bias. Further research is needed to confirm these findings

Postpartum Mental Health and Breastfeeding Practices: An Analysis Using the 2010–2011 Pregnancy Risk Assessment Monitoring System

Evidence suggests that women with postpartum depression (PPD) are at risk for early breastfeeding cessation, but previous studies have been limited by small samples. The objective of this analysis is to estimate the association between PPD symptoms and breastfeeding using a national, stratified, random sample of U.S. mothers

Real-time cleaning performance feedback

Monitoring contamination levels on parts during cleaning operations will provide feedback that can be useful in reducing waste generation and air emissions caused by over- or under-cleaning. Such real-time process controls can help eliminate pollution in a wide variety of industries, including aerospace, electronics, and metal finishing

Collaborative Research: Research and Curriculum Development in Thermal Physics

This project is a continuation of an ongoing program of coordinated research and research-based curriculum development in thermal physics, primarily in the advanced-level undergraduate courses. Data are gathered using one-on-one student interviews, written pre- and post-test questions, and multiple-choice surveys. The research is then applied to the development of curricular materials intended to improve student understanding in a manner consistent with active-learning methods previously shown to be effective in physics instruction. Prior support has resulted in the development of several interview protocols, diagnostic questions, and survey questions. Project staff have identified several specific conceptual difficulties in thermal physics, and have developed some preliminary curricular materials that have been pilot tested at the home institutions to address these difficulties. This project is adding to the existing data corpus and extending existing work and products to new topics in thermal physics. Existing materials and materials being developed during this project are being evaluated for their effectiveness at addressing student difficulties identified through research. Ancillary materials that integrate our curricular materials more fully into courses and provide instructors with background information and assessment questions are being developed. A set of supporting materials, including pre- and post-tests, homework exercises, and a brief instructors\u27 guide with background on the content and our research findings as well as suggestions for implementation, are being prepared. Materials are applicable to courses taught from a classical thermodynamics and/or a statistical mechanics perspective. With its sharp focus on upper-division courses, this project is expanding the applicability of standard physics education research methods already widely used in introductory courses. Results from this aspect of the project are of great interest to the physics education research community and to instructors of advanced physics courses. The dissemination of both research results and of curricular materials in publications, in presentations at national and international meetings of physicists, physics educators and education researchers, and via pilot testing at participating institutions is contributing to the improvement of instruction in thermal physics nationally and internationally. There are additional interdisciplinary components to this work. One focus of both the research and the curricular materials is the connections between the physics and associated mathematics. In addition, results of the investigations in physics courses are being compared to the results from analogous courses in chemistry, engineering, and geological sciences. The aim is to compare the prevalence and persistence of specific difficulties or beliefs among these populations and to explore the extent to which the different discipline-specific approaches and instructional strategies affect student learning of thermodynamics