Characteristics of GaInNAsSb VCSELs operating near 1.55µm

A detailed study of the high-power pulsed operation of C-band optically-pumped GaInNAsSb vertical cavity surface emitting lasers is reported. The devices employ a resonant periodic gain structure grown by molecular beam epitaxy on a GaAs substrate with a 31-pair GaAs/AlAs bottom distributed Bragg reflector and a 4-λ, GaAs-based resonant cavity containing 10 GaInNAsSb quantum wells distributed among the 7 antinodes of the electric field. A dual-pump-band SiO2/TiO2 dielectric top mirror allows efficient optical pumping via low reflectivities at 808nm and 1064nm while providing very high reflectivity at the 1.55μm target emission wavelength. The laser characteristics were evaluated using both a Q-switched Nd:YAG 1064nm pump and a 20W-peak 180ns-pulsed 850nm diode laser. The importance of the gain-cavity detuning was evident from time-dependent spectral measurements of laser material subjected to post-growth annealing at different temperatures between 725 and 775°C. The highest annealing temperature produces the largest blue shift of the gain peak relative to the cavity resonance, resulting in the best power transfer characteristics as well as reduced temperature sensitivity

Physiotherapy practice in the private sector: organizational characteristics and models.

BACKGROUND: Even if a large proportion of physiotherapists work in the private sector worldwide, very little is known of the organizations within which they practice. Such knowledge is important to help understand contexts of practice and how they influence the quality of services and patient outcomes. The purpose of this study was to: 1) describe characteristics of organizations where physiotherapists practice in the private sector, and 2) explore the existence of a taxonomy of organizational models. METHODS: This was a cross-sectional quantitative survey of 236 randomly-selected physiotherapists. Participants completed a purpose-designed questionnaire online or by telephone, covering organizational vision, resources, structures and practices. Organizational characteristics were analyzed descriptively, while organizational models were identified by multiple correspondence analyses. RESULTS: Most organizations were for-profit (93.2%), located in urban areas (91.5%), and within buildings containing multiple businesses/organizations (76.7%). The majority included multiple providers (89.8%) from diverse professions, mainly physiotherapy assistants (68.7%), massage therapists (67.3%) and osteopaths (50.2%). Four organizational models were identified: 1) solo practice, 2) middle-scale multiprovider, 3) large-scale multiprovider and 4) mixed. CONCLUSIONS: The results of this study provide a detailed description of the organizations where physiotherapists practice, and highlight the importance of human resources in differentiating organizational models. Further research examining the influences of these organizational characteristics and models on outcomes such as physiotherapists' professional practices and patient outcomes are needed

La preuve psychologique devant les tribunaux : barrières communicationnelles et épistémiques = Psychological evidence in court: communicational and epidemic barriers

Le présent article vise à documenter les défis liés à la communication entre décideurs judiciaires et psychologues experts, leurs rôles différents et besoins respectifs de même que les difficultés des psychologues experts à traduire les connaissances en psychologie au profit de meilleures décisions judiciaires. Trois concepts psychologiques seront examinés plus attentivement : la dangerosité, la capacité parentale et le meilleur intérêt de l’enfant. Nous rappellerons les besoins de formation spécialisée à la lumière des défis identifiés ainsi que l’importance d’une utilisation éthique des connaissances dans le domaine de la psychologie pour éclairer les tribunaux. The present article discusses some pitfalls in regards to the communication between legal decision makers and forensic psychologists, their respective roles and needs and the difficulty in translating psychological knowledge in the courtroom. Three psychological concepts will be discussed in greater detail: dangerousness, best interests of the child and parenting capacity. We underline the importance of specialized training in regard to the pitfalls discussed in this article and of an ethical use of the knowledge in psychology to assist the court

Rare-earth monosulfides as durable and efficient cold cathodes

In their rocksalt structure, rare-earth monosulfides offer a more stable alternative to alkali metals to attain low or negative electron affinity when deposited on various III-V and II-VI semiconductor surfaces. In this article, we first describe the successful deposition of Lanthanum Monosulfide via pulsed laser deposition on Si and MgO substrates and alumina templates. These thin films have been characterized by X-ray diffraction, atomic force microscopy, high resolution transmission electron microscopy, ellipsometry, Raman spectroscopy, ultraviolet photoelectron spectroscopy and Kelvin probe measurements. For both LaS/Si and LaS/MgO thin films, the effective work function of the submicron thick thin films was determined to be about 1 eV from field emission measurements using the Scanning Anode Field Emission Microscopy technique. The physical reasons for these highly desirable low work function properties were explained using a patchwork field emission model of the emitting surface. In this model, nanocrystals of low work function materials having a orientation perpendicular to the surface and outcropping it are surrounded by a matrix of amorphous materials with higher work function. To date, LaS thin films have been used successfully as cold cathode emitters with measured emitted current densities as high as 50 A/cm2. Finally, we describe the successful growth of LaS thin films on InP substrates and, more recently, the production of LaS nanoballs and nanoclusters using Pulsed Laser Ablation.Comment: 61 pages, 24 figure

Detection of Hepatitis E virus in swine using real-time RT-PCR

The zoonotic transmtsswn potential of Hepatitis E virus (HEY) is now widely recognized. Swine represents the main animal reservoir for this virus in many countries, including Canada. In recent years, different real-time RT-PCR assays were developed and proposed as reliable and sensitive detection methods. However, the quality of extracted RNA, presence of inhibitors and RN ase contamination of the samples may impact on the detection results obtained with these molecular methods. The aim of this study was to evaluate the use of a sample process control (SPC) within a real-time RT-PCR assay for the detection ofHEV. This TaqMan multiplex assay was afterwards used to evaluate the viral load ofHEV in organs, tissues and excreta of normal pigs at slaughter. HEY RNA was detected in at least one sample from 14 out of the 43 animals tested (32.6 %). HEV was present in lymph nodes (25.6%), bladder (23.3%), liver (20.9%), bile (18.6%), feces (13.9%), tonsils (7.0%) and plasma (2.3%) but was undetected in loins

Oceans and human health : navigating changes on Canada’s coasts

Ocean conditions can affect human health in a variety of ways that are often overlooked and unappreciated. Oceans adjacent to Canada are affected by many anthropogenic stressors, with implications for human health and well-being. Climate change further escalates these pressures and can expose coastal populations to unique health hazards and distressing conditions. However, current research efforts, education or training curriculums, and policies in Canada critically lack explicit consideration of these ocean–public health linkages. The objective of this paper is to present multiple disciplinary perspectives from academics and health practitioners to inform the development of future directions for research, capacity development, and policy and practice at the interface of oceans and human health in Canada. We synthesize major ocean and human health linkages in Canada, and identify climate-sensitive drivers of change, drawing attention to unique considerations in Canada. To support effective, sustained, and equitable collaborations at the nexus of oceans and human health, we recommend the need for progress in three critical areas: (i) holistic worldviews and perspectives, (ii) capacity development, and (iii) structural supports. Canada can play a key role in supporting the global community in addressing the health challenges of climate and ocean changes

Reciprocity as a foundation of financial economics

This paper argues that the subsistence of the fundamental theorem of contemporary financial mathematics is the ethical concept ‘reciprocity’. The argument is based on identifying an equivalence between the contemporary, and ostensibly ‘value neutral’, Fundamental Theory of Asset Pricing with theories of mathematical probability that emerged in the seventeenth century in the context of the ethical assessment of commercial contracts in a framework of Aristotelian ethics. This observation, the main claim of the paper, is justified on the basis of results from the Ultimatum Game and is analysed within a framework of Pragmatic philosophy. The analysis leads to the explanatory hypothesis that markets are centres of communicative action with reciprocity as a rule of discourse. The purpose of the paper is to reorientate financial economics to emphasise the objectives of cooperation and social cohesion and to this end, we offer specific policy advice

Physician Attitudes towards Pharmacological Cognitive Enhancement: Safety Concerns Are Paramount

The ethical dimensions of pharmacological cognitive enhancement have been widely discussed in academic circles and the popular media, but missing from the conversation have been the perspectives of physicians - key decision makers in the adoption of new technologies into medical practice. We queried primary care physicians in major urban centers in Canada and the United States with the aim of understanding their attitudes towards cognitive enhancement. Our primary hypothesis was that physicians would be more comfortable prescribing cognitive enhancers to older patients than to young adults. Physicians were presented with a hypothetical pharmaceutical cognitive enhancer that had been approved by the regulatory authorities for use in healthy adults, and was characterized as being safe, effective, and without significant adverse side effects. Respondents overwhelmingly reported increasing comfort with prescribing cognitive enhancers as the patient age increased from 25 to 65. When asked about their comfort with prescribing extant drugs that might be considered enhancements (sildenafil, modafinil, and methylphenidate) or our hypothetical cognitive enhancer to a normal, healthy 40 year old, physicians were more comfortable prescribing sildenafil than any of the other three agents. When queried as to the reasons they answered as they did, the most prominent concerns physicians expressed were issues of safety that were not offset by the benefit afforded the individual, even in the face of explicit safety claims. Moreover, many physicians indicated that they viewed safety claims with considerable skepticism. It has become routine for safety to be raised and summarily dismissed as an issue in the debate over pharmacological cognitive enhancement; the observation that physicians were so skeptical in the face of explicit safety claims suggests that such a conclusion may be premature. Thus, physician attitudes suggest that greater weight be placed upon the balance between safety and benefit in consideration of pharmacological cognitive enhancement

Caribou, Petroleum, and the Limits of Locality in the Canada–US Borderlands

his article discusses Karsten Heuer’s 2006 book Being Caribou in light of debates in ecocriticism and border studies about how to define the local in the context of environmental problems of vast range and uncertain temporality. It explores how Heuer’s book about following the Porcupine Caribou herd’s migration engages in multiple forms of boundary crossing—between countries, between hemispheric locations, and between species—and shows how insights from Indigenous storytelling complicate the book’s appeal to environmentalist readers by asserting a prior, transnational Indigenous presence in the transboundary landscapes of present-day Alaska and the Yukon