An experimental investigation of laminar free convection heat transfer form the surface of a vertical circular cylinder

M.S.Charles W. Gorto

Exciting dark matter in the galactic center

We reconsider the proposal of excited dark matter (DM) as an explanation for excess 511 keV gamma rays from positrons in the galactic center. We quantitatively compute the cross section for DM annihilation to nearby excited states, mediated by exchange of a new light gauge boson with off-diagonal couplings to the DM states. In models where both excited states must be heavy enough to decay into e^+ e^- and the ground state, the predicted rate of positron production is never large enough to agree with observations, unless one makes extreme assumptions about the local circular velocity in the Milky Way, or alternatively if there exists a metastable population of DM states which can be excited through a mass gap of less than 650 keV, before decaying into electrons and positrons.Comment: Dedicated to the memory of Lev Kofman; 16 pages, 9 figures; v3 added refs, minor changes, accepted to PR

Process-based models in Eucalyptus plantation management : reality and perspectives

Yield prediction in commercial forestry has been dominated by empirical modelling. Increasingly, however, process-based models are finding application either in support or instead of these traditional models. In this paper we draw the new forestry demands and how these models can answer different kinds of questions such as forest productivity in planted areas and new plantation, water-use, carbon sequestration and effects of climate change on forest production. In this paper we review current performance against management needs, concentrating in particular on the application of the 3-PG (Landsberg and Waring, 1997) and CABALA (Battaglia et al., 2004) process-based models. In general we find that process-based models have met many of the expectations of a decade ago. The paper briefly indicates new opportunities of process-based models in the area of wood properties and wood products prediction and in the area of forest health assessment.___________________________________La predicción de rendimientos en la silvicultura comercial ha estado dominada hasta ahora por el empleo de técnicas de modelización empíricas. Sin embargo, los modelos basados en procesos se están utilizando cada vez más como suplementos o incluso sustitutos de los tradicionales. En este artículo apuntamos nuevas demandas forestales y la forma en que los nuevos modelos pueden dar respuesta a diferentes cuestiones como la productividad forestal tanto en zonas plantadas como en nuevas plantaciones, el uso del agua, el secuestro de carbono y los efectos del cambio climático en la producción forestal. Asimismo, valoramos la eficacia de los modelos frente a las necesidades actuales de gestión, sobre todo en lo relativo a la aplicación de dos modelos basados en procesos: 3-PG (Landsberg y Waring, 1997) y CABALA (Battaglia et al., 2004). En general, los modelos de este tipo han colmado muchas de las expectativas que suscitaron hace una década. En este artículo se esbozan nuevas aplicaciones para estos modelos en cuanto a la predicción de propiedades y productos de la madera, así como a la valoración de la salud de los bosques

Do Postsecondary Internships Address the Four Learning Modes of Experiential Learning Theory? An Exploration through Document Analysis

The educational benefits of embedding hands-on experience in higher education curriculum are widely recognized (Beard & Wilson, 2013). However, to optimize the learning from these opportunities, they need to be grounded in empirical learning theory. The purpose of this study was to examine the characteristics of internships in Ontario colleges and universities, and to assess the congruence between the components of these internships and Kolb’s (1984) experiential learning framework. Information from 44 Ontario universities and colleges, including 369 internship program webpages and 77 internship course outlines, was analyzed. The findings indicated that internship programs overemphasize the practical aspect of the experience at the expense of linking theory and practice. To optimize experiential education opportunities, recommendations include establishing explicit learning activities consistent with each experiential learning mode, including practice, reflection, connecting coursework and practical experience, and implementing creative ideas in practice.  Les avantages éducatifs de l’intégration d’une expérience pratique au sein du curriculum de l’éducation supérieure sont grandement reconnus (Beard et Wilson, 2013). Toutefois, afin d’optimiser les occasions d’apprentissage, celles-ci doivent être basées sur des théories d’apprentissage empiriques. Le but de cette étude était d’examiner les caractéristiques des stages dans des collèges et universités de l’Ontario, ainsi que d’évaluer la corrélation entre les composantes de ces stages et le cadre de travail de l’apprentissage par l’expérience selon Kolb (1984). L’information provenant de 44 universités et collèges ontariens, incluant les sites Internet de 369 programmes de stage et les plans de cours de 77 stages, a été analysée. Les résultats indiquent que les programmes de stage insistent trop sur les aspects pratiques de l’expérience plutôt que de lier la théorie à la pratique. Afin d’optimiser les possibilités éducatives d’apprentissage, les recommandations comprennent l’établissement d’activités d’apprentissage explicites qui soient compatibles avec chaque modèle d’apprentissage par l’expérience, incluant la pratique, la réflexion, des travaux liés à l’expérience pratique, et la mise en œuvre d’idées créatives dans la pratique

End to end simulator for the WIVERN W-band Doppler conically scanning spaceborne radar

The WIVERN (WInd VElocity Radar Nephoscope) mission, soon entering in Phase-0 of the ESA Earth Explorer program, promises to complement Doppler wind lidar by globally observing, for the first time, vertical profiles of winds in cloudy areas. This work describes an end to end simulator of the WIVERN conically scanning 94 GHz Doppler radar, the only payload of the mission. Specific features of the simulator are: the conically scanning geometry; the inclusion of cross-polarization effects and of the simulation of a radiometric mode; the applicability to global cloud model outputs via an orbital model; the incorporation of a mispointing model accounting for thermo-elastic distortions, microvibrations, startrackers uncertainties, etc.; the inclusion of the surface clutter. Some of the simulator capabilities are showcased for a case study involving a full rotational scan of the instrument. The simulator represents a very useful tool for studying the performances of the WIVERN concept and possible trade-offs for the different configurations (e.g. different antenna sizes, pulse lengths, antenna patterns, . . . ). Thanks to its modular structure the simulator can be easily adapted to different orbits, different scanning geometries and different frequencie

Characterization of surface radar cross sections at W-band at moderate incidence angles

This paper presents the results of a recent flight campaign conducted over the Great Lakes region and reports the first observations of the W-band normalized backscattered cross section ( σ0 ) for V and H polarization and the linear depolarization ratios (LDRs) from different types of surfaces at moderate incidence angles (<70°). For sea surfaces, while the observed σ0 behaves as previously reported at small incidence angles, it features a marked decrease with increasing incidence angles between 20° and 50°. There is a strong dependence of normalized backscattered cross sections both on the wind speed and on the wind direction, with larger values found in the presence of higher wind speeds and when the radar antenna is looking upwind. This is in line with theoretical models (though models tend to overpredict the range of variability at a given incidence angle) and with observations at lower frequencies. The LDRs are steadily increasing from values certainly lower than −30 dB, at vertical incidence, to the values of about −10 dB, at the incidence angles of about 60°–70°, with a good matching between observations and theoretical predictions. On the other hand, land surface backscattering properties are not characterized by a strong angular dependence: σ0 and LDR values typically range between −20 and 0 dB and between −15 and −5 dB, respectively. This paper is relevant for spaceborne concepts of W-band radars, which envisage moderate incidence angles to achieve a broad swath needed for global coverage

The Relationship Between Adverse Childhood Experiences and Moral Injury in the Canadian Armed Forces

Background: There is increasing evidence that moral injuries (MIs) may affect the mental health of Canadian Armed Forces (CAF) members and veterans. Despite knowledge suggesting that MIs are related to multiple negative mental health outcomes, including the onset of post-traumatic stress disorder (PTSD), it is unknown whether pre-traumatic variables, including the presence of childhood abuse, are related to MIs. Objective: This study seeks to investigate the potential relationship between adverse childhood experiences and later onset MI in military members. Methods: Thirty-three patients newly admitted to an inpatient unit for treatment of trauma-related disorders received a standardized self-assessment package, including the PTSD Checklist for DSM-5 (PCL-5), the Moral Injury Events Scale (MIES; adapted for the Canadian context), and the Adverse Childhood Experiences Questionnaire (ACE-Q), which is a retrospective measure of childhood abuse. Results: Analyses revealed a significant relation between childhood emotional abuse and the presence of MI in adulthood. Specifically, emotional abuse during childhood was correlated with total score on the MIES (p = 0.006) and with its two subscales, perceived betrayals (p = 0.022) and perceived transgressions (p = 0.016). These correlations remained significant when controlling for age and gender. Conclusions: Among CAF members and veterans, childhood events are related to the presence of MI during adulthood. These preliminary data are provocative in suggesting that emotional abuse during childhood may increase the likelihood of endorsing MI during adult military service. Further work is needed to identify pre-traumatic variables that may serve to increase risk or enhance resilience to the development of MI in military members

Colitis Induced Microvascular Leak Triggers Colonic Dysmotility

Graduate Basi

Polymorphisms in leucine-rich repeat genes are associated with autism spectrum disorder susceptibility in populations of European ancestry

BACKGROUND: Autism spectrum disorders (ASDs) are a group of highly heritable neurodevelopmental disorders which are characteristically comprised of impairments in social interaction, communication and restricted interests/behaviours. Several cell adhesion transmembrane leucine-rich repeat (LRR) proteins are highly expressed in the nervous system and are thought to be key regulators of its development. Here we present an association study analysing the roles of four promising candidate genes - LRRTM1 (2p), LRRTM3 (10q), LRRN1 (3p) and LRRN3 (7q) - in order to identify common genetic risk factors underlying ASDs. METHODS: In order to gain a better understanding of how the genetic variation within these four gene regions may influence susceptibility to ASDs, a family-based association study was undertaken in 661 families of European ancestry selected from four different ASD cohorts. In addition, a case-control study was undertaken across the four LRR genes, using logistic regression in probands with ASD of each population against 295 ECACC controls. RESULTS: Significant results were found for LRRN3 and LRRTM3 (P < 0.005), using both single locus and haplotype approaches. These results were further supported by a case-control analysis, which also highlighted additional SNPs in LRRTM3. CONCLUSIONS: Overall, our findings implicate the neuronal leucine-rich genes LRRN3 and LRRTM3 in ASD susceptibility