Nano-scale optical and electrical probes of materials and processes.

This report describes the investigations and milestones of the Nano-Scale Optical and Electrical Probes of Materials and Processes Junior/Senior LDRD. The goal of this LDRD was to improve our understanding of radiative and non-radiative mechanisms at the nanometer scale with the aim of increasing LED and solar cell efficiencies. These non-radiative mechanisms were investigated using a unique combination of optical and scanning-probe microscopy methods for surface, materials, and device evaluation. For this research we utilized our new near-field scanning optical microscope (NSOM) system to aid in understanding of defect-related emission issues for GaN-based materials. We observed micrometer-scale variations in photoluminescence (PL) intensity for GaN films grown on Cantilever Epitaxy pattern substrates, with lower PL intensity observed in regions with higher dislocation densities. By adding electrical probes to the NSOM system, the photocurrent and surface morphology could be measured concurrently. Using this capability we observed reduced emission in InGaN MQW LEDs near hillock-shaped material defects. In spatially- and spectrally-resolved PL studies, the emission intensity and measured wavelength varied across the wafer, suggesting the possibility of indium segregation within the InGaN quantum wells. Blue-shifting of the InGaN MQW wavelength due to thinning of quantum wells was also observed on top of large-scale ({micro}m) defect structures in GaN. As a direct result of this program, we have expanded the awareness of our new NSOM/multifunctional SPM capability at Sandia and formed several collaborations within Sandia and with NINE Universities. Possible future investigations with these new collaborators might include GaN-based compound semiconductors for green LEDs, nanoscale materials science, and nanostructures, novel application of polymers for OLEDs, and phase imprint lithography for large area 3D nanostructures

COMPUTER SIMULATIONS OF POSSIBLE FUTURES FOR TWO FLOCKS OF WHOOPING CRANES

We conducted computer simulations using the program VORTEX (version 7) to project population sizes, growth rates, genetic diversity, and probabilities of extinction over the next 100 years for 2 flocks of whooping cranes (Grus americana), the Aransas/Wood Buffalo population and the experimental Florida population. Standard runs based on best estimates of demographic. genetic, and environmental parameter values were used as a baseline to which several alternative scenarios were compared. Results generally supported the conclusion of the earlier Population Viability Assessment (Mirande et al. 1991) that the AransaslWood Buffalo population will continue to grow steadily with less than a 1 % probability of extinction. It was noted, however, that a combination of negative factors such as shrinking habitat and increased probabilities of catastrophes accompanied by increased mortality rates could put this population at risk. Results for the Florida population were less optimistic. The standard run produced a population growth rate (r) of only 0.0026 for the next 100 years, and this shifted down to -0.0001 over a 200-year time frame. Adult mortality in this flock would have to be about 20% lower than the predicted value (10%) in order to raise growth rates to above r = 0.02. Amount and duration of supplementation of the Florida flock had minimal impacts on the long-tenn growth rate of the flock. It is the enduring rates of mortality, breeding, and disease risk that will have major effects on this population. For example, if disease risks tum out to be greater than the best-estimate scenario, this population could face a relatively high risk of extinction (17%). The formula for success in Florida is lower adult mortality, lower age of first breeding, lower disease risk, and higher productivity than the best-guess estimates. Fortunately, there are some potential management interventions (e.g., predator control, vaccines and health monitoring, selective introductions to balance the sex ratio of the flock) that may be able to push the odds in favor of success

Final LDRD report : design and fabrication of advanced device structures for ultra high efficiency solid state lighting.

The goal of this one year LDRD was to improve the overall efficiency of InGaN LEDs by improving the extraction of light from the semiconductor chip. InGaN LEDs are currently the most promising technology for producing high efficiency blue and green semiconductor light emitters. Improving the efficiency of InGaN LEDs will enable a more rapid adoption of semiconductor based lighting. In this LDRD, we proposed to develop photonic structures to improve light extraction from nitride-based light emitting diodes (LEDs). While many advanced device geometries were considered for this work, we focused on the use of a photonic crystal for improved light extraction. Although resonant cavity LEDs and other advanced structures certainly have the potential to improve light extraction, the photonic crystal approach showed the most promise in the early stages of this short program. The photonic crystal (PX)-LED developed here incorporates a two dimensional photonic crystal, or photonic lattice, into a nitride-based LED. The dimensions of the photonic crystal are selected such that there are very few or no optical modes in the plane of the LED ('lateral' modes). This will reduce or eliminate any radiation in the lateral direction so that the majority of the LED radiation will be in vertical modes that escape the semiconductor, which will improve the light-extraction efficiency. PX-LEDs were fabricated using a range of hole diameters and lattice constants and compared to control LEDs without a photonic crystal. The far field patterns from the PX-LEDs were dramatically modified by the presence of the photonic crystal. An increase in LED brightness of 1.75X was observed for light measured into a 40 degree emission cone with a total increase in power of 1.5X for an unencapsulated LED

Proceedings of the 13th annual conference of INEBRIA

CITATION: Watson, R., et al. 2016. Proceedings of the 13th annual conference of INEBRIA. Addiction Science & Clinical Practice, 11:13, doi:10.1186/s13722-016-0062-9.The original publication is available at https://ascpjournal.biomedcentral.comENGLISH SUMMARY : Meeting abstracts.https://ascpjournal.biomedcentral.com/articles/10.1186/s13722-016-0062-9Publisher's versio

Mobile phone text message reminders of antipsychotic medication:is it time and who should receive them? A cross-sectional trust-wide survey of psychiatric inpatients

BACKGROUND: Poor adherence to antipsychotic medication is a widespread problem, and the largest predictor of relapse in patients with psychosis. Electronic reminders are increasingly used to improve medication adherence for a variety of medical conditions, but have received little attention in the context of psychotic disorders. We aimed to explore the feasibility and acceptability of including short message service (SMS) medication reminders in the aftercare plan of service users discharged from inpatient care on maintenance antipsychotic medication. METHODS: We conducted a cross-sectional, trust-wide survey in the inpatient units of the Oxleas National Health Service (NHS) Foundation Trust in the UK between June 29 and August 3, 2012. Using a self-report questionnaire and the Drug Attitude Inventory, we examined inpatient attitudes towards antipsychotic drugs, past adherence to antipsychotic medication, frequency of mobile phone ownership, and interest in receiving SMS medication reminders upon discharge from the ward. Predictors of a patient’s interest in receiving electronic reminders were examined using simple logistic regression models. RESULTS: Of 273 inpatients, 85 met eligibility criteria for the survey, showed decisional capacity, and agreed to participate. Of the 85 respondents, over a third (31-35%) admitted to have forgotten to take/collect their antipsychotic medication in the past, and approximately half (49%) to have intentionally skipped their antipsychotics or taken a smaller dose than prescribed. Male patients (55%), those with negative attitudes towards antipsychotics (40%), and those unsatisfied with the information they received on medication (35%) were approximately 3 to 4 times more likely to report past intentional poor adherence. The large majority of respondents (80-82%) reported having a mobile phone and knowing how to use SMS, and a smaller majority (59%) expressed an interest in receiving SMS medication reminders after discharge. No variable predicted a patient’s interest in receiving electronic reminders of antipsychotics. CONCLUSIONS: Automatic SMS reminders of antipsychotic medication were acceptable to the majority of the survey respondents as an optional service offered upon discharge from inpatient care. Automatic electronic reminders deserve further investigation as a flexible, minimally invasive, cost-effective and broadly applicable tool that can potentially improve antipsychotic adherence and clinical outcomes

Need for open data on COVID-19 vaccine uptake among pregnant people in the Caribbean: a call to action

Pregnant people with coronavirus disease 2019 (COVID-19) have a higher risk of adverse maternal and fetal outcomes compared with pregnant people without COVID-19. In 2021, large increases in maternal mortality were reported in Jamaica, almost half of which were attributable to COVID-19. COVID-19 vaccination has been shown to reduce these risks, but low- and middle-income countries lack free, publicly available data, known as open data, on COVID-19 vaccine uptake for their pregnant populations. The objectives of this paper were to: review how high-income countries use open data to detect trends in COVID-19 vaccine uptake among pregnant people and develop vaccination distribution strategies; outline barriers to making open data available for maternal COVID-19 vaccination in the Caribbean; and propose a multipronged strategy that would increase the availability of open data on maternal COVID-19 vaccination in the Caribbean. A multipronged strategy to fill the data void would involve: (i) utilizing existing Caribbean maternal immunization data collection entities; (ii) adapting digital software tools to establish maternal electronic immunization registries; and (iii) collaborating with local partners skilled in data analytics. Making open data available for COVID-19 vaccine uptake among pregnant people in the Caribbean could offer substantial benefits, including the development of measurable maternal COVID-19 vaccination goals and the facilitation of vaccine decision-making discussions between providers and pregnant people

Le financement des infrastructures de transport XVIIe-début XIXe siècle

Entre la fin du XVIIe siècle et le début du XIXe siècle, les États ont massivement encouragé la construction et l’entretien des infrastructures routières, fluviales et maritimes, pour des raisons tant politiques qu’économiques. Le financement de tels investissements, qui peuvent nécessiter d’importants capitaux, pose des problèmes spécifiques requérant l’intervention de l’État, et constitue un défi majeur dans les économies dites précapitalistes. L’objectif de ce livre, qui trouve un écho avec les enjeux actuels, est donc de comprendre comment certains États ont été en mesure, dans un contexte de fortes contraintes budgétaires, de financer d’ambitieuses politiques d’aménagement en mobilisant des ressources croissantes et diverses (péages, impôts, emprunts, réquisition de main-d'œuvre, dons…). À travers des contributions traitant de la France, de l’Angleterre, de la Suède, de l’Électorat de Trêves et de la Chine, cet ouvrage s’attache également à saisir l’évolution des circuits financiers, des dispositifs comptables et des procédures de contrôle. Il propose en outre une réflexion à différentes échelles, sur les relations entre l’État et ses administrés, le gouvernement et les pouvoirs locaux, les autorités publiques et les acteurs privés

A revolution in micropower : the catalytic nanodiode.

Our ability to field useful, nano-enabled microsystems that capitalize on recent advances in sensor technology is severely limited by the energy density of available power sources. The catalytic nanodiode (reported by Somorjai's group at Berkeley in 2005) was potentially an alternative revolutionary source of micropower. Their first reports claimed that a sizable fraction of the chemical energy may be harvested via hot electrons (a 'chemicurrent') that are created by the catalytic chemical reaction. We fabricated and tested Pt/GaN nanodiodes, which eventually produced currents up to several microamps. Our best reaction yields (electrons/CO{sub 2}) were on the order of 10{sup -3}; well below the 75% values first reported by Somorjai (we note they have also been unable to reproduce their early results). Over the course of this Project we have determined that the whole concept of 'chemicurrent', in fact, may be an illusion. Our results conclusively demonstrate that the current measured from our nanodiodes is derived from a thermoelectric voltage; we have found no credible evidence for true chemicurrent. Unfortunately this means that the catalytic nanodiode has no future as a micropower source