InGaN nano-ring structures for high-efficiency light emitting diodes

A technique based on the Fresnel diffraction effect for the fabrication of nano-scale site-controlled ring structures in InGaN/GaN multi-quantum well structures has been demonstrated. The ring structures have an internal diameter of 500 nm and a wall width of 300 nm. A 1 cm-1 Raman shift has been measured, signifying substantial strain relaxation from the fabricated structure. The 9 nm blueshift observed in the cathodoluminescence spectra can be attributed to band filling and/or screening of the piezoelectric field. A light emitting diode based on this geometry has been demonstrated. © 2005 American Institute of Physics.published_or_final_versio

Mechanical Properties of End-crosslinked Entangled Polymer Networks using Sliplink Brownian Dynamics Simulations

The mechanical properties of a polymeric network containing both crosslinks and sliplinks (entanglements) are studied using a multi-chain Brownian dynamics simulation. We coarse-grain at the level of chain segments connecting consecutive nodes (cross- or sliplinks), with particular attention to the Gaussian statistics of the network. Affine displacement of nodes is not imposed: their displacement as well as sliding of monomers through sliplinks is governed by force balances. The simulation results of stress in uniaxial extension and the full stress tensor in simple shear including the (non-zero) second normal stress difference are presented for monodisperse chains with up to 18 entanglements between two crosslinks. The cases of two different force laws of the subchains (Gaussian chains and chains with finite extensibility) for two different numbers of monomers in a subchain (no = 50 and no = 100) are examined. It is shown that the additivity assumption of slip- and crosslink contribution holds for sufficiently long chains with two or more entanglements, and that it can be used to construct the strain response of a network of infinitely long chains. An important consequence is that the contribution of sliplinks to the small-strain shear modulus is about ⅔ of the contribution of a crosslink

Advancing Marine Biogeochemical and Ecosystem Reanalyses and Forecasts as Tools for Monitoring and Managing Ecosystem Health

Ocean ecosystems are subject to a multitude of stressors, including changes in ocean physics and biogeochemistry, and direct anthropogenic influences. Implementation of protective and adaptive measures for ocean ecosystems requires a combination of ocean observations with analysis and prediction tools. These can guide assessments of the current state of ocean ecosystems, elucidate ongoing trends and shifts, and anticipate impacts of climate change and management policies. Analysis and prediction tools are defined here as ocean circulation models that are coupled to biogeochemical or ecological models. The range of potential applications for these systems is broad, ranging from reanalyses for the assessment of past and current states, and short-term and seasonal forecasts, to scenario simulations including climate change projections. The objectives of this article are to illustrate current capabilities with regard to the three types of applications, and to discuss the challenges and opportunities. Representative examples of global and regional systems are described with particular emphasis on those in operational or pre-operational use. With regard to the benefits and challenges, similar considerations apply to biogeochemical and ecological prediction systems as do to physical systems. However, at present there are at least two major differences: (1) biogeochemical observation streams are much sparser than physical streams presenting a significant hinderance, and (2) biogeochemical and ecological models are largely unconstrained because of insufficient observations. Expansion of biogeochemical and ecological observation systems will allow for significant advances in the development and application of analysis and prediction tools for ocean biogeochemistry and ecosystems, with multiple societal benefits

Oneida nation of New York: health needs assessment 1990

This is the report of a health needs assessment for the Oneida Indian Nation of New York (ONNY). This needs assessment was conducted in order to collect population-based data related to behavioral risks and reproductive health for Oneida males and females. The survey of the Oneida was initiated because there is almost no risk factor data available on Indian tribes of the northeast, and none available for the Oneida Nation of New York. There are four primary goals for the 1990 Oneida Nation Health Needs Assessment. They are 1) to collect behavioral risk factor and reproductive health data for adult Oneida Nation members living on or near Oneida Nation lands, 2) to assess the current basic health needs of the ONNY, 3) to document the medical providers and hospitals which are currently being utilized by the Nation members and. 4) to develop recommendations for use by health planners from this baseline data.The Oneida Nation Health Needs Assessment (ONHNA) was carried out among enrolled members of the Oneida Nation who were 18 years of age and older who lived in the six counties that are contiguous to the Oneida Nation lands. The Nation Enrollment List was used to identify the Oneida population located in the six-county area. The choice to interview only adults was made to avoid legal difficulties in interviewing minors. Interviewing was conducted in each household face-to-face rather than using mailed questionnaires or telephone contact. All interviewers were enrolled Oneida Nation members. Interviews were conducted by interviewers of the same sex as the respondent. All interviewers participated in one week of training prior to the start of the field work. Four types of data were collected. First, the behavioral risk factors surveyed were related to the 10 leading causes of death in the United States. Behavioral factors include seat belt usage, physical exercise, diet, cigarette and smokeless tobacco usage, alcohol consumption, and the existence of high blood pressure. The second data set included health needs. The survey questions dealt with the prevalence of current diseases and health problems among the Oneidas, and with whether the Oneida people have routine screening tests such as cholesterol, diabetes, and hypertension, and eye exams, pap smears, breast exams, and rectal exams. The third set of data questions focused on reproductive health factors. Questions covered topics such as fertility, contraception, and general maternal-child health conditions. The fourth and final set of questions gathered data on health care utilization. This data will be used to establish health provider contracts with physicians, dentists, pediatricians, and hospitals to provide quality health care for a more reasonable cost. For each risk factor, comparisons were made between the Oneida Nation and data from the 1988 New York State Behavioral Risk Factor Survey.The individual completion rates were 54% for females and 69% for males for a total of 211 respondents in all. The following is an abbreviated summary of selected data from the survey. Seat belt use was only slightly lower than for all New Yorkers. Non-use was highest among young drivers. Sixty percent of Oneida males and 78 percent of Oneida females reported having their blood pressure taken within a year of the survey. All Oneida members were more active physically than the general New York population. However, all Oneida members were more likely to be overweight by comparison Forty percent of all Oneida people are smokers compared to 25 percent of the New York population. Fifty-seven percent of Oneida males and 32 percent of Oneida females are classified as acute and heavy drinkers. Percentages for regular health checks across all factors vary considerably among the Oneida people. Several areas of concern were identified including cholesterol checks, diabetes screening, rectal exams and mammograms. The completed fertility of the Oneida women in this survey is 2.1 children which is lower than that of all U.S. women surveyed in the 1980 census. Female sterilization is the most prevalent contraceptive method among Oneida women. as it is among the general U.S. population.With respect to behavioral risks, cigarette smoking and alcohol consumption are of major concern. This impacts on concerns for overall reproductive health. The task now is to identify the highest priority objectives and to secure resources needed to accomplish these tasks

Ionic high-pressure form of elemental boron

Boron is an element of fascinating chemical complexity. Controversies have shrouded this element since its discovery was announced in 1808: the new 'element' turned out to be a compound containing less than 60-70 percent of boron, and it was not until 1909 that 99-percent pure boron was obtained. And although we now know of at least 16 polymorphs, the stable phase of boron is not yet experimentally established even at ambient conditions. Boron's complexities arise from frustration: situated between metals and insulators in the periodic table, boron has only three valence electrons, which would favour metallicity, but they are sufficiently localized that insulating states emerge. However, this subtle balance between metallic and insulating states is easily shifted by pressure, temperature and impurities. Here we report the results of high-pressure experiments and ab initio evolutionary crystal structure predictions that explore the structural stability of boron under pressure and, strikingly, reveal a partially ionic high-pressure boron phase. This new phase is stable between 19 and 89 GPa, can be quenched to ambient conditions, and has a hitherto unknown structure (space group Pnnm, 28 atoms in the unit cell) consisting of icosahedral B12 clusters and B2 pairs in a NaCl-type arrangement. We find that the ionicity of the phase affects its electronic bandgap, infrared adsorption and dielectric constants, and that it arises from the different electronic properties of the B2 pairs and B12 clusters and the resultant charge transfer between them.Comment: Published in Nature 453, 863-867 (2009

Outcome measurement in functional neurological disorder: a systematic review and recommendations.

OBJECTIVES: We aimed to identify existing outcome measures for functional neurological disorder (FND), to inform the development of recommendations and to guide future research on FND outcomes. METHODS: A systematic review was conducted to identify existing FND-specific outcome measures and the most common measurement domains and measures in previous treatment studies. Searches of Embase, MEDLINE and PsycINFO were conducted between January 1965 and June 2019. The findings were discussed during two international meetings of the FND-Core Outcome Measures group. RESULTS: Five FND-specific measures were identified-three clinician-rated and two patient-rated-but their measurement properties have not been rigorously evaluated. No single measure was identified for use across the range of FND symptoms in adults. Across randomised controlled trials (k=40) and observational treatment studies (k=40), outcome measures most often assessed core FND symptom change. Other domains measured commonly were additional physical and psychological symptoms, life impact (ie, quality of life, disability and general functioning) and health economics/cost-utility (eg, healthcare resource use and quality-adjusted life years). CONCLUSIONS: There are few well-validated FND-specific outcome measures. Thus, at present, we recommend that existing outcome measures, known to be reliable, valid and responsive in FND or closely related populations, are used to capture key outcome domains. Increased consistency in outcome measurement will facilitate comparison of treatment effects across FND symptom types and treatment modalities. Future work needs to more rigorously validate outcome measures used in this population

Evaluation of Phage Display Discovered Peptides as Ligands for Prostate-Specific Membrane Antigen (PSMA)

The aim of this study was to identify potential ligands of PSMA suitable for further development as novel PSMA-targeted peptides using phage display technology. The human PSMA protein was immobilized as a target followed by incubation with a 15-mer phage display random peptide library. After one round of prescreening and two rounds of screening, high-stringency screening at the third round of panning was performed to identify the highest affinity binders. Phages which had a specific binding activity to PSMA in human prostate cancer cells were isolated and the DNA corresponding to the 15-mers were sequenced to provide three consensus sequences: GDHSPFT, SHFSVGS and EVPRLSLLAVFL as well as other sequences that did not display consensus. Two of the peptide sequences deduced from DNA sequencing of binding phages, SHSFSVGSGDHSPFT and GRFLTGGTGRLLRIS were labeled with 5-carboxyfluorescein and shown to bind and co-internalize with PSMA on human prostate cancer cells by fluorescence microscopy. The high stringency requirements yielded peptides with affinities KD∼1 μM or greater which are suitable starting points for affinity maturation. While these values were less than anticipated, the high stringency did yield peptide sequences that apparently bound to different surfaces on PSMA. These peptide sequences could be the basis for further development of peptides for prostate cancer tumor imaging and therapy. © 2013 Shen et al

On the Generalizability of Experimental Results

The age-old question of the generalizability of the results of experiments that are conducted in artificial laboratory settings to more realistic inferential and decision making situations is considered in this paper. Conservatism in probability revision provides an example of a result that 1) has received wide attention, including attention in terms of implications for real-world decision making, on the basis of experiments conducted in artificial settings and 2) is now apparently thought by many to be highly situational and not at all a ubiquitous phenomenon, in which case its implications for real-world decision making are not as extensive as originally claimed. In this paper we consider the questions of generalizations from the laboratory to the real world in some detail, both within the context of the experiments regarding conservatism and within a more general context. In addition, we discuss some of the difficulties inherent in experimentation in realistic settings, suggest possible procedures for avoiding or at least alleviating such difficulties, and make a plea for more realistic experiments