31 research outputs found
Camera-independent learning and image quality assessment for super-resolution
An increasing number of applications require high-resolution images in situations where the access to the sensor and the knowledge of its specifications are limited. In this thesis, the problem of blind super-resolution is addressed, here defined as the estimation of a high-resolution image from one or more low-resolution inputs, under the condition that the degradation model parameters are unknown. The assessment of super-resolved results, using objective measures of image quality, is also addressed.Learning-based methods have been successfully applied to the single frame super-resolution problem in the past. However, sensor characteristics such as the Point Spread Function (PSF) must often be known. In this thesis, a learning-based approach is adapted to work without the knowledge of the PSF thus making the framework camera-independent. However, the goal is not only to super-resolve an image under this limitation, but also to provide an estimation of the best PSF, consisting of a theoretical model with one unknown parameter.In particular, two extensions of a method performing belief propagation on a Markov Random Field are presented. The first method finds the best PSF parameter by performing a search for the minimum mean distance between training examples and patches from the input image. In the second method, the best PSF parameter and the super-resolution result are found simultaneously by providing a range of possible PSF parameters from which the super-resolution algorithm will choose from. For both methods, a first estimate is obtained through blind deconvolution and an uncertainty is calculated in order to restrict the search.Both camera-independent adaptations are compared and analyzed in various experiments, and a set of key parameters are varied to determine their effect on both the super-resolution and the PSF parameter recovery results. The use of quality measures is thus essential to quantify the improvements obtained from the algorithms. A set of measures is chosen that represents different aspects of image quality: the signal fidelity, the perceptual quality and the localization and scale of the edges.Results indicate that both methods improve similarity to the ground truth and can in general refine the initial PSF parameter estimate towards the true value. Furthermore, the similarity measure results show that the chosen learning-based framework consistently improves a measure designed for perceptual quality
Consommation et agressions sexuelles : évaluation d’une intervention préventive en milieu collégial
La littĂ©rature Ă©tablit un lien entre la consommation de drogues et d’alcool et les agressions sexuelles. Ă€ cet effet, l’alcool constitue la substance la plus utilisĂ©e lors d’une agression sexuelle. Cependant, la perception des jeunes reste associĂ©e au GHB lorsqu’on aborde la thĂ©matique des drogues du viol. L’étude vise Ă examiner les effets d’une intervention prĂ©ventive quant au changement dans les connaissances d’étudiants de niveau collĂ©gial face aux substances pouvant faciliter une agression. En tout, 623 étudiants ont participĂ© Ă l’intervention et ont rĂ©pondu Ă des questionnaires de prĂ©test et de post-test, tandis que 247 étudiants composaient le groupe contrĂ´le. Les rĂ©sultats indiquent un effet positif de l’intervention en post-test, de sorte que les participants ciblent davantage l’alcool comme Ă©tant la première substance reliĂ©e aux agressions sexuelles. De plus, ils reconnaissent davantage le rĂ´le de la consommation en tant que facteur de risque Ă une agression. Par ailleurs, les rĂ©sultats indiquent Ă©galement que l’alcool seul ne fait pas l’unanimitĂ© en tant que substance la plus utilisĂ©e pour faciliter une agression. Les participants tendent Ă mentionner d’autres substances telles que certains mĂ©dicaments mĂ©langĂ©s avec l’alcool. Les rĂ©sultats suscitent la rĂ©flexion quant Ă l’utilitĂ© d’aborder plusieurs substances qui pourraient, au dire des jeunes, ĂŞtre utilisĂ©es dans un contexte d’agression sexuelle. Il semble que l’intervention aurait plutĂ´t intĂ©rĂŞt Ă dĂ©tailler le rĂ´le de l’alcool et le contexte de son utilisation dans la crĂ©ation d’une dynamique d’agression. De plus, l’information devrait porter sur la relation sexuelle sans consentement ou forcĂ©e pour correspondre Ă la rĂ©alitĂ© des jeunes auprès desquels l’intervention a lieu. Les nuances pourraient alors ĂŞtre mises en Ă©vidence pour aborder le niveau de consommation d’alcool en fonction de la quantitĂ© ingĂ©rĂ©e, le sexe du consommateur et les contextes de consommation.The literature establishes a link between drug and alcohol consumption and sexual assault. Alcohol is the substance most often used during a sexual assault. However, the perception of young people remains associated with GHB when addressing the issue of date rape drugs. The main goal of the study was to examine the effects of a preventive intervention on the knowledge of college students concerning substances that can facilitate a sexual assault. 623 students participated in the intervention and completed the pre- and post-test questionnaires, while 247 students were in the control group. The results showed that the intervention had a positive effect on the post-test results. Participants focused more on alcohol as the substance the most often used to facilitate sexual assaults. Moreover, they recognized the role of the consumption as a risk factor to such assault. The results also indicated that participants in the intervention group were not unanimous in referring to alcohol as the substance most often used to facilitate an assault. They tended to mention other substances such as certain medications combined with alcohol. The results suggest considering the utility of addressing several substances which could, according to the participants, be used in a context of sexual assault. It appears that, in the intervention, it would be better to detail the role of alcohol and the context of its use in creating a dynamic of assault. In addition, information should cover a sexual relationship without consent or forced, so that it corresponds to the reality of youth at the college level. These distinctions could then be highlighted to discuss the level of alcohol consumption according to the quantity ingested, the consumer’s gender and the context of the consumption.La bibliografĂa establece un vĂnculo entre el consumo de alcohol y de drogas y las agresiones sexuales. El alcohol es la sustancia más utilizada en las agresiones sexuales. Sin embargo, cuando se trata el tema de las drogas y la violaciĂłn, la percepciĂłn de los jĂłvenes asocia esta Ăşltima al Ă©xtasis lĂquido (GHB). El estudio tiene como objetivo examinar los efectos de una intervenciĂłn preventiva para cambiar el conocimiento de los estudiantes de nivel colegial postsecundario sobre las sustancias que pueden facilitar una agresiĂłn. En total, 623 estudiantes participaron de la intervenciĂłn y respondieron a los cuestionarios previos y posteriores a la misma, mientras que 247 estudiantes integraron el grupo de control. Los resultados de los cuestionarios posteriores a la intervenciĂłn demuestran un efecto positivo de la misma, puesto que los participantes consideran en mayor medida al alcohol como la primera sustancia relacionada con las agresiones sexuales. Además, los resultados señalan tambiĂ©n en mayor medida el papel del consumo como un factor de riesgo para una agresiĂłn. Por otra parte, los resultados indican asimismo que el alcohol solo no está considerado de manera unánime como la sustancia más utilizada para facilitar una agresiĂłn. Los participantes tienden a mencionar otras sustancias, como ciertos medicamentos mezclados con el alcohol. Estos resultados llaman a la reflexiĂłn en cuanto a la utilidad de tratar muchas sustancias que podrĂan, segĂşn los jĂłvenes, utilizarse en un contexto de agresiĂłn sexual. ParecerĂa que la intervenciĂłn deberĂa detallar el papel del alcohol y del contexto de su uso en la creaciĂłn de una dinámica de agresiĂłn. Además, la informaciĂłn deberĂa referirse a la relaciĂłn sexual sin consentimiento o forzada, para que corresponda con la realidad de los jĂłvenes con los cuales tuvo lugar la intervenciĂłn. PodrĂan ponerse en evidencia entonces los matices que permitan tratar el nivel de consumo de alcohol en funciĂłn de la cantidad ingerida, del sexo del consumidor y de los contextos de consumo
Drogues du viol et agression sexuelle : perception de jeunes en milieu collégial
La littĂ©rature scientifique indique que l’usage de substances (alcool et drogues), particulièrement chez les jeunes, peut gĂ©nĂ©rer un Ă©tat de vulnĂ©rabilitĂ© propice Ă l’agression sexuelle, notamment Ă cause de pĂ©riodes de blackout, et que l’alcool serait surtout en cause. Cependant, l’oubli pouvant dĂ©couler d’une consommation abusive a Ă©tĂ© mĂ©diatisĂ© et prĂ©sentĂ© comme rĂ©sultant de la consommation de « drogues du viol », notamment le GHB. La littĂ©rature rapporte Ă©galement des relations entre l’adhĂ©sion Ă de fausses croyances entourant le viol (mythes) et l’agression sexuelle elle-mĂŞme. L’étude vise Ă vĂ©rifier les liens possibles entre la prĂ©sence de mythes entourant le viol et la frĂ©quence d’épisodes de consommation menant Ă l’oubli chez des Ă©tudiants de niveau collĂ©gial de la rĂ©gion de MontrĂ©al. La perception des substances pouvant ĂŞtre liĂ©es Ă l’agression sexuelle chez les jeunes est Ă©galement explorĂ©e. Les rĂ©sultats indiquent que, pour les Ă©tudiants, le GHB constitue la drogue la plus souvent associĂ©e au viol, mĂŞme si l’alcool est Ă©galement identifiĂ©. On observe aussi que ceux qui rapportent le plus frĂ©quemment avoir eu une pĂ©riode d’oubli Ă cause d’une consommation d’alcool ou de drogue adhèrent davantage Ă de fausses croyances reliĂ©es au viol que les autres. Il serait souhaitable d’explorer davantage les liens entre la consommation de substances et l’agression sexuelle en vue d’établir un lien de causalitĂ© entre les deux. De mĂŞme, compte tenu des statistiques disponibles, il serait important d’intĂ©grer de l’information concernant la consommation de substances dans les programmes de prĂ©vention des agressions sexuelles.Current literature indicates that the use of substances such as drugs and alcohol, particularly by youths, can lead to a state of vulnerability propitious to sexual assault, but that it is alcohol that has generally been linked to abuse. However, lack of recollection that can result from excessive consumption has been portrayed in the media as an effect of “date rape drugs”, such as GHB. Studies also suggest some links between rape myths acceptance and sexual assault. Therefore, the goals of the current study were to verify the perceptions held by college level students from the Montreal area in regards to substances linked to sexual assault. Possible relations between the existing rape myths and the frequency of substance abuse leading to amnesia were also explored. According to the youths who participated in the current study, GHB represent the drug most often linked to rape, even if alcohol was also identified. Moreover, results revealed that the group of youths who acknowledged often forgetting parts of an evening due to excessive use of drugs or alcohol tended to hold a greater amount of false beliefs regarding rape, in comparison to the others. Among our recommendations, we should explore the links between substance use and sexual assault to establish a causal relation between the two factors. Also, it would be beneficial to include information regarding the use of substances within the sexual assault prevention programs.La bibliografĂa cientĂfica indica que el uso de sustancias psicotrĂłpicas (alcohol y drogas), particularmente entre los jĂłvenes, puede generar un estado de vulnerabilidad propicio para la agresiĂłn sexual, principalmente a causa de los perĂodos de blackout que generan, y que el alcohol serĂa el principal cuestionado. Sin embargo, el olvido que puede resultar de un consumo abusivo ha sido mediatizado y presentado como el resultado del consumo de “drogas de la violaciĂłn”, principalmente GHB. La bibliografĂa informa asimismo sobre la relaciĂłn existente entre la adhesiĂłn a falsas creencias en torno a la violaciĂłn (mitos) y la agresiĂłn sexual misma. El estudio apunta a verificar los vĂnculos posibles entre la presencia de mitos en torno a la violaciĂłn y la frecuencia de episodios de consumo de sustancias psicotrĂłpicas que producen olvido entre los estudiantes de los colegios postsecundarios de enseñanza general y profesional de Montreal. Se analiza tambiĂ©n la percepciĂłn de las sustancias que pueden estar relacionadas con la agresiĂłn sexual entre los jĂłvenes. Los resultados indican que la GHB es la droga que los estudiantes asocian con más frecuencia a las violaciones, aun cuando el alcohol tambiĂ©n está identificado. Se observa además que aquĂ©llos que declaran más a menudo haber tenido un perĂodo de olvido a causa del consumo de alcohol o de drogas son más propensos que los demás a adherir a las falsas creencias relacionadas con la violaciĂłn. SerĂa deseable explorar aĂşn más los vĂnculos entre el consumo de sustancias psicotrĂłpicas y la agresiĂłn sexual, con el objetivo de establecer una relaciĂłn de causalidad entre ambos. Asimismo, teniendo en cuenta las estadĂsticas disponibles, serĂa importante integrar en los programas de prevenciĂłn de agresiones sexuales la informaciĂłn concerniente al consumo de sustancias psicotrĂłpicas
Effects of protection and sediment stress on coral reefs in Saint Lucia
The extent to which Marine Protected Areas (MPAs) benefit corals is contentious. On one hand, MPAs could enhance coral growth and survival through increases in herbivory within their borders; on the other, they are unlikely to prevent disturbances, such as terrestrial runoff, that originate outside their boundaries. We examined the effect of spatial protection and terrestrial sediment on the benthic composition of coral reefs in Saint Lucia. In 2011 (10 to 16 years after MPAs were created), we resurveyed 21 reefs that had been surveyed in 2001 and analyzed current benthic assemblages as well as changes in benthic cover over that decade in relation to protection status, terrestrial sediment influence (measured as the proportion of terrigenous material in reef-associated sediment) and depth. The cover of all benthic biotic components has changed significantly over the decade, including a decline in coral and increase in macroalgae. Protection status was not a significant predictor of either current benthic composition or changes in composition, but current cover and change in cover of several components were related to terrigenous content of sediment deposited recently. Sites with a higher proportion of terrigenous sediment had lower current coral cover, higher macroalgal cover and greater coral declines. Our results suggest that terrestrial sediment is an important factor in the recent degradation of coral reefs in Saint Lucia and that the current MPA network should be complemented by measures to reduce runoff from land
Guide de lutilisation pédagogique des médias sociaux
Titre de l'écran-titre (visionné le 24 jan. 2013)Cette publication est mise à disposition selon les termes de la licence "Créative Commons". Vous êtes libres de l'utiliser, en tout ou en partie en citant l'auteur, vous ne pouvez pas l'utiliser pour un usage commercial et vous n'êtes pas autorisés à la modifier
Substantially improved pharmacokinetics of recombinant human butyrylcholinesterase by fusion to human serum albumin
<p>Abstract</p> <p>Background</p> <p>Human butyrylcholinesterase (huBChE) has been shown to be an effective antidote against multiple LD<sub>50 </sub>of organophosphorus compounds. A prerequisite for such use of huBChE is a prolonged circulatory half-life. This study was undertaken to produce recombinant huBChE fused to human serum albumin (hSA) and characterize the fusion protein.</p> <p>Results</p> <p>Secretion level of the fusion protein produced <it>in vitro </it>in BHK cells was ~30 mg/liter. Transgenic mice and goats generated with the fusion constructs expressed in their milk a bioactive protein at concentrations of 0.04–1.1 g/liter. BChE activity gel staining and a size exclusion chromatography (SEC)-HPLC revealed that the fusion protein consisted of predominant dimers and some monomers. The protein was confirmed to have expected molecular mass of ~150 kDa by Western blot. The purified fusion protein produced <it>in vitro </it>was injected intravenously into juvenile pigs for pharmacokinetic study. Analysis of a series of blood samples using the Ellman assay revealed a substantial enhancement of the plasma half-life of the fusion protein (~32 h) when compared with a transgenically produced huBChE preparation containing >70% tetramer (~3 h). <it>In vitro </it>nerve agent binding and inhibition experiments indicated that the fusion protein in the milk of transgenic mice had similar inhibition characteristics compared to human plasma BChE against the nerve agents tested.</p> <p>Conclusion</p> <p>Both the pharmacokinetic study and the <it>in vitro </it>nerve agent binding and inhibition assay suggested that a fusion protein retaining both properties of huBChE and hSA is produced <it>in vitro </it>and <it>in vivo</it>. The production of the fusion protein in the milk of transgenic goats provided further evidence that sufficient quantities of BChE/hSA can be produced to serve as a cost-effective and reliable source of BChE for prophylaxis and post-exposure treatment.</p
Drogues du viol et agression sexuelle : perception de jeunes en milieu collégial1
La littĂ©rature scientifique indique que l’usage de substances (alcool et drogues), particulièrement chez les jeunes, peut gĂ©nĂ©rer un Ă©tat de vulnĂ©rabilitĂ© propice Ă l’agression sexuelle, notamment Ă cause de pĂ©riodes de blackout, et que l’alcool serait surtout en cause. Cependant, l’oubli pouvant dĂ©couler d’une consommation abusive a Ă©tĂ© mĂ©diatisĂ© et prĂ©sentĂ© comme rĂ©sultant de la consommation de « drogues du viol », notamment le GHB. La littĂ©rature rapporte Ă©galement des relations entre l’adhĂ©sion Ă de fausses croyances entourant le viol (mythes) et l’agression sexuelle elle-mĂŞme. L’étude vise Ă vĂ©rifier les liens possibles entre la prĂ©sence de mythes entourant le viol et la frĂ©quence d’épisodes de consommation menant Ă l’oubli chez des Ă©tudiants de niveau collĂ©gial de la rĂ©gion de MontrĂ©al. La perception des substances pouvant ĂŞtre liĂ©es Ă l’agression sexuelle chez les jeunes est Ă©galement explorĂ©e. Les rĂ©sultats indiquent que, pour les Ă©tudiants, le GHB constitue la drogue la plus souvent associĂ©e au viol, mĂŞme si l’alcool est Ă©galement identifiĂ©. On observe aussi que ceux qui rapportent le plus frĂ©quemment avoir eu une pĂ©riode d’oubli Ă cause d’une consommation d’alcool ou de drogue adhèrent davantage Ă de fausses croyances reliĂ©es au viol que les autres. Il serait souhaitable d’explorer davantage les liens entre la consommation de substances et l’agression sexuelle en vue d’établir un lien de causalitĂ© entre les deux. De mĂŞme, compte tenu des statistiques disponibles, il serait important d’intĂ©grer de l’information concernant la consommation de substances dans les programmes de prĂ©vention des agressions sexuelles.Current literature indicates that the use of substances such as drugs and alcohol, particularly by youths, can lead to a state of vulnerability propitious to sexual assault, but that it is alcohol that has generally been linked to abuse. However, lack of recollection that can result from excessive consumption has been portrayed in the media as an effect of “date rape drugs”, such as GHB. Studies also suggest some links between rape myths acceptance and sexual assault. Therefore, the goals of the current study were to verify the perceptions held by college level students from the Montreal area in regards to substances linked to sexual assault. Possible relations between the existing rape myths and the frequency of substance abuse leading to amnesia were also explored. According to the youths who participated in the current study, GHB represent the drug most often linked to rape, even if alcohol was also identified. Moreover, results revealed that the group of youths who acknowledged often forgetting parts of an evening due to excessive use of drugs or alcohol tended to hold a greater amount of false beliefs regarding rape, in comparison to the others. Among our recommendations, we should explore the links between substance use and sexual assault to establish a causal relation between the two factors. Also, it would be beneficial to include information regarding the use of substances within the sexual assault prevention programs.La bibliografĂa cientĂfica indica que el uso de sustancias psicotrĂłpicas (alcohol y drogas), particularmente entre los jĂłvenes, puede generar un estado de vulnerabilidad propicio para la agresiĂłn sexual, principalmente a causa de los perĂodos de blackout que generan, y que el alcohol serĂa el principal cuestionado. Sin embargo, el olvido que puede resultar de un consumo abusivo ha sido mediatizado y presentado como el resultado del consumo de “drogas de la violaciĂłn”, principalmente GHB. La bibliografĂa informa asimismo sobre la relaciĂłn existente entre la adhesiĂłn a falsas creencias en torno a la violaciĂłn (mitos) y la agresiĂłn sexual misma. El estudio apunta a verificar los vĂnculos posibles entre la presencia de mitos en torno a la violaciĂłn y la frecuencia de episodios de consumo de sustancias psicotrĂłpicas que producen olvido entre los estudiantes de los colegios postsecundarios de enseñanza general y profesional de Montreal. Se analiza tambiĂ©n la percepciĂłn de las sustancias que pueden estar relacionadas con la agresiĂłn sexual entre los jĂłvenes. Los resultados indican que la GHB es la droga que los estudiantes asocian con más frecuencia a las violaciones, aun cuando el alcohol tambiĂ©n está identificado. Se observa además que aquĂ©llos que declaran más a menudo haber tenido un perĂodo de olvido a causa del consumo de alcohol o de drogas son más propensos que los demás a adherir a las falsas creencias relacionadas con la violaciĂłn. SerĂa deseable explorar aĂşn más los vĂnculos entre el consumo de sustancias psicotrĂłpicas y la agresiĂłn sexual, con el objetivo de establecer una relaciĂłn de causalidad entre ambos. Asimismo, teniendo en cuenta las estadĂsticas disponibles, serĂa importante integrar en los programas de prevenciĂłn de agresiones sexuales la informaciĂłn concerniente al consumo de sustancias psicotrĂłpicas
Le passage du secondaire au collégial et les départs des étudiants en sciences de la nature
Comprend des références bibliographique
Évaluation de l’implantation initiale d’un protocole d’évaluation des troubles du comportement à l’école primaire pour les psychoéducateurs
Occupant une place de plus en plus grande parmi les professionnels qui oeuvrent dans les écoles primaires au Québec, les psychoéducateurs sont souvent mandatés pour évaluer les élèves qui présentent des difficultés d’adaptation d’ordre comportemental. À l’heure actuelle, peu de pratiques rigoureuses d’évaluation ont été développées pour ces psychoéducateurs. Cette étude vise à évaluer l’implantation initiale d’un protocole d’évaluation d’élèves ayant des troubles du comportement proposé à des psychoéducateurs d’école primaire. Au total, 22 psychoéducateurs ainsi que cinq acteurs clefs de commission scolaire ont participé à une entrevue téléphonique visant à recueillir l’appréciation de cette pratique novatrice. Les résultats ont permis de faire ressortir les forces, les limites, les contraintes liées à son utilisation ainsi que les retombées du protocole sur la pratique des psychoéducateurs.Psychoeducators are playing an increasing role among professionals in primary schools, and they are often mandated to assess students with behavioral disorders. Until now, however, few rigorous evaluation practices have been developed for psychoeducators. This study aims to evaluate the initial implementation of an assessment protocol for behavioral disorders that has been proposed for primary school psychoeducators. A total of 22 psychoeducators and five school board administrators were interviewed to understand their appreciation of this innovative practice. Results were used to highlight the strengths, limits and constraints of use as well as benefits of the protocol on the psychoeducators’ evaluation practices