Converting energy from fusion into useful forms

If fusion power reactors are to be feasible, it will still be necessary to convert the energy of the nuclear reaction into usable form. The heat produced will be removed from the reactor core by a primary coolant, which might be water, helium, molten lithium-lead, molten lithium-containing salt, or CO2. The heat could then be transferred to a conventional Rankine cycle or Brayton (gas turbine) cycle. Alternatively it could be used for thermochemical processes such as producing hydrogen or other transport fuels. Fusion presents new problems because of the high energy neutrons released. These affect the selection of materials and the operating temperature, ultimately determining the choice of coolant and working cycle. The limited temperature ranges allowed by present day irradiated structural materials, combined with the large internal power demand of the plant, will limit the overall thermal efficiency. The operating conditions of the fusion power source, the materials, coolant, and energy conversion system will all need to be closely integrated.Comment: 22 pages, 4 figures, Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy December 11, 201

Toward an Expanded Conceptualization of Transformative Learning: A Case Study of International Service-Learning in Nicaragua

This dissertation research stems from both practical and theoretical problems related to understanding the nature of transformation in international service-learning. In terms of the practical problems, the primary motivation for conducting this study had to do with pedagogical challenges associated with fostering adult college students\u27 transformational learning as the coordinator and instructor of Tompkins Cortland Community College\u27s international service learning program (TC3-NICA)1 over the past eight years. A review of theoretical and empirical literature in the fields of adult learning, service-learning, and intercultural learning did not adequately address the concerns that ( had about the significant and problematic nature of change TC3-NICA students were experiencing as a result of their participation in service in Nicaragua

Quantitative sensory testing in painful hand osteoarthritis demonstrates features of peripheral sensitisation.

Hand osteoarthritis (HOA) is a prevalent condition for which treatments are based on analgesia and physical therapies. Our primary objective was to evaluate pain perception in participants with HOA by assessing the characteristics of nodal involvement, pain threshold in each hand joint, and radiological severity. We hypothesised that inflammation in hand osteoarthritis joints enhances sensitivity and firing of peripheral nociceptors, thereby causing chronic pain. Participants with proximal and distal interphalangeal (PIP and DIP) joint HOA and non-OA controls were recruited. Clinical parameters of joint involvement were measured including clinical nodes, VAS (visual analogue score) for pain (0-100 mm scale), HAQ (health assessment questionnaire), and Kellgren-Lawrence scores for radiological severity and pain threshold measurement were performed. The mean VAS in HOA participants was 59.3 mm ± 8.19 compared with 4.0 mm ± 1.89 in the control group (P < 0.0001). Quantitative sensory testing (QST) demonstrated lower pain thresholds in DIP/PIP joints and other subgroups in the OA group including the thumb, metacarpophalangeal (MCPs), joints, and wrists (P < 0.008) but not in controls (P = 0.348). Our data demonstrate that HOA subjects are sensitised to pain due to increased firing of peripheral nociceptors. Future work to evaluate mechanisms of peripheral sensitisation warrants further investigation

« Prévention primaire des psychopathologies » : appellation contrôlée

La prévention psychosociale est souvent une notion galvaudée et abordée avec une familiarité trompeuse. Plusieurs facteurs peuvent expliquer en partie ce mauvais usage : réactions confuses au modèle médical, association inopportune des termes "préventif" et "communautaire", distinction plus ou moins claire entre trois niveaux de prévention, malentendu autour du concept de facteur de risque et définition trop générale du concept de promotion. Une des spécificités du fait psychopathologique est qu'il se prête mal à une dichotomie "avant /après" l'apparition des symptômes. C'est pourquoi le champ préventif devrait identifier ses cibles en fonction de facteurs étiologiques plutôt que symptomatologiques. Ainsi, pour nous, la véritable prévention ne devrait comprendre que des interventions proactives destinées, soit à la neutralisation d'influences pathogènes, soit à la promotion de compétences susceptibles de rendre la population plus robuste.Psychosocial prevention is often, and mistakenly, disparaged or approached with unwarranted familiarity. A number of factors could provide a partial explanation for this mistake: confused rea-tions to the medical model, an unfortunate association of the terms "preventive" and "community," lack of distinction between three levels of prevention, misunderstandings around the concept of risk factor, and an overly general definition of the concept of promotion. One specific fact about psychopathology is that it does not fit well into the dichotomous "before / after" appearance of symptoms. This is why the preventive field must identify its targets in terms of etiological rather than symptomological factors. Thus, for us, true prevention must include only proactive interventions meant either for neutralization of pathological influences, or for promotion of areas that are aimed at making the population healthier

Towards a Critical Theory of Adult Learning/Education: Transformational Theory and Beyond

Given the great promise of critical theory to transform the field of adult education and its understanding of adult learning, indeed, to create, as Mezirow boldly proclaimed two decades ago, a critical theory of adult learning, where are we now

L’après-suicide, une expérience unique de deuil?

Le groupe d'étude national sur le suicide au Canada suggère que les personnes qui vivent un deuil suite à un suicide forment un groupe à risque suicidaire. La littérature rapporte que ces endeuillés ont un taux de suicide neuf fois plus élevé que la population générale. Des auteurs suggèrent que ce type de deuil est plus intense et plus long que d'autres formes de deuil, constat que d'autres ont remis en doute. Qu'en est-il? Le deuil suite à un suicide est-il différent? S'agit-il d'une expérience unique de deuil? Un examen attentif de l'ensemble des études nous apprend que le deuil suite à un suicide présente des caractéristiques particulières, qui se manifestent davantage chez des personnes plus vulnérables.Canada's national task force on suicide suggests that people who mourn a suicide make up a group that is itself at risk. Literature shows that mourners of a suicide have a suicide rate that is nine times higher than average. While some authors suggest that this type of mourning is more intense and of a longer duration that for other types of mourning, other authors doubt this hypothesis. But what happens in reality ? Is suicide mourning truly different from other types of mourning? Is it really a unique mourning experience? These are some of the questions the authors of this article have attempted to answer. Following an in-depth review of studies on the matter, the authors conclude that the mourning of a suicide encompasses certain characteristics that manifest themselves especially in more vulnerable people

BNP/NT-proBNP in pulmonary arterial hypertension: time for point-of-care testing?

Despite the advent of new therapies and improved outcomes in patients with pulmonary arterial hypertension (PAH), it remains a life-shortening disease and the time to diagnosis remains unchanged. Strategies to improve outcomes are therefore currently focused on earlier diagnosis and a treatment approach aimed at moving patients with PAH into a category of low-risk of 1-year mortality. B-type natriuretic peptide (BNP; or brain natriuretic peptide) and N-terminal prohormone of BNP (NT-proBNP) are released from cardiac myocytes in response to mechanical load and wall stress. Elevated levels of BNP and NT-proBNP are incorporated into several PAH risk stratification tools and screening algorithms to aid diagnosis of systemic sclerosis. We have undertaken a systematic review of the literature with respect to the use of BNP and NT-proBNP in PAH and the use of these biomarkers in the diagnosis and risk stratification of PAH, their relation to pulmonary haemodynamics and the potential for point-of-care testing to improve diagnosis and prognosis

Gender, education, and cohort differences in healthy working life expectancy at age 50 years in Australia: a longitudinal analysis

Background: We aimed to estimate healthy working life expectancy (HWLE) at age 50 years by gender, cohort, and level of education in Australia. Methods: We analysed data from two nationally representative cohorts in the Household Income and Labour Dynamics in Australia survey. Each cohort was followed up annually from 2001 to 2010 and from 2011 to 2020. Poor health was defined by a self-reported, limiting, long-term health condition. Work was defined by current employment status. HWLEs were estimated with Interpolated Markov Chain multi-state modelling. Findings: We included data from 4951 participants in the cohort from 2001 to 2010 (2605 [53%] women and 2346 [47%] men; age range 50–100 years) and 6589 participants in the cohort from 2011 to 2020 (3518 [53%] women and 3071 [47%] men; age range 50–100 years). Baseline characteristics were similar between groups. Working life expectancy increased over time for all groups, regardless of gender or educational attainment. However, health expectancies only increased for men and people of either gender with higher education. Years working in good health at age 50 years for men were 9·9 years in 2001 (95% CI 9·3–10·4) and 10·8 years (10·4–11·3) in 2011. The corresponding HWLEs for women were 7·9 years (7·3–8·5) and 9·0 years (8·5–9·6). For people with low education level, HWLE was 7·9 years (7·3–8·5) in 2001 and 8·4 years (7·9–8·9) in 2011, and for those with high education level, HWLE rose from 9·6 years in 2001 (9·1–10·1) to 10·5 years in 2011 (10·2–10·9). Across all groups, there were at least 2·5 years working in poor health and 6·7 years not working in good health. Interpretation: Increases in length of working life have not been accompanied by similar gains in healthy life expectancy for women or people of any gender with low education, and it is not unusual for workers older than 50 years to work with long-term health limitations. Strategies to achieve longer working lives should address life-course inequalities in health and encourage businesses and organisations to recruit, train, and retain mature-age workers. Funding: Australian Research Council

Biomineralization of PbS and PbS-CdS core-shell nanocrystals and their application in quantum dot sensitized solar cells

Biomineralization utilizes biological systems to synthesize functional inorganic materials for application in diverse fields. In the current work, we enable biomineralization of quantum confined PbS and PbS–CdS core–shell nanocrystals and demonstrate their application in quantum dot sensitized solar cells (QDSSCs). An engineered strain of Stenotrophomonas maltophilia is utilized to generate a cystathionine γ-lyase that is active for the biomineralization of metal sulfide nanocrystals from a buffered aqueous solution of metal salts and L-cysteine. In the presence of lead acetate, this enzymatic route generates rock salt structured PbS nanocrystals. Controlling the growth conditions yields ∼4 nm PbS crystals with absorption and photoluminescence peaks at 910 nm and 1080 nm, respectively, consistent with the expected strong quantum confinement of PbS at this size. Quantum yields (QY) of the biomineralized PbS quantum dots, determined after phase transfer to the organic phase, range between 16 and 45%. These are the highest reported QY values for any biomineralized quantum dot materials to date and are comparable with QYs reported for chemically synthesized materials. Subsequent exposure to cadmium acetate results in the biomineralization of a thin CdS shell on the PbS core with a resultant blue-shift in optical properties. The photoluminescence peak shifts to 980 nm, consistent with the expected decrease in band gap energy of a PbS–CdS core–shell heterostructured quantum dot. HAADF-STEM imaging confirms the crystalline structure and size of the particles with complimentary XEDS analysis confirming the presence of Cd, Pb, and S in individual nanocrystals. Integration of these QDs into QDSSCs yields open circuit potentials of 0.43 V and 0.59 V for PbS and PbS–CdS, respectively, consistent with expectations for these materials and previously reported values for chemically synthesized QDs

Severe acute respiratory syndrome coronavirus 2 and blood safety : an updated review

Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a novel human coronavirus first identified in late 2019 and subsequently declared a worldwide pandemic in March 2020. In this review, we provide an overview of the implications of SARS-CoV-2 for blood safety and sufficiency. Summary: Approximately one-third of SARS-CoV-2 infections are asymptomatic. The reported mean incubation period typically varies from 2 to 11 days, but longer periods up to 22 days have been reported. The blood phase of SARS-CoV-2 appears to be brief and low level, with RNAaemia detectable in only a small proportion of patients, typically associated with more severe disease and not demonstrated to be infectious virus. A small number of presymptomatic and asymptomatic blood phase cases have been reported. Transfusion-transmission (TT) of SARS-CoV-2 has not been reported. Therefore, the TT risk associated with SARS-CoV-2 is currently theoretical. To mitigate any potential TT risk, but more importantly to prevent respiratory transmission in donor centers, blood services can implement donor deferral policies based on travel, disease status, or potential risk of exposure and encourage staff vaccination. Key Messages: The TT risk of SARS-CoV-2 appears to be low. The biggest risk to blood services in the current COVID-19 pandemic is to maintain the sufficiency of the blood supply while minimizing respiratory transmission of SARS-CoV-2 to donors and staff while donating blood