A Sex-Linked Allele, Autosomal Modifiers and Temperature-Dependence Appear to Regulate Melanism in Male Mosquitofish (Gambusia holbrooki)

About 1% of male mosquitofish (Gambusia holbrooki) express melanic (mottled-black) body coloration, which differs dramatically from the wild-type, silvery-gray coloration. Here, I report on the genetic inheritance pattern of melanic coloration, which indicates Y-linkage, and at least one autosomal modifier. Phenotypic expression of melanism is also affected by temperature. Expression is constitutive ( temperature insensitive) in some populations, inducible ( temperature sensitive) in others. Constitutive and inducible expression occur among geographically proximal populations. However, males from any single population demonstrate the same constitutive or inducible expression pattern as one another. The F1 males from inter-population crosses demonstrate temperature-related expression patterns like their sires\u27. As well, the sex ratio of melanic males\u27 progeny differs among populations. Here, inter-population crosses demonstrate a sex-ratio bias in the same direction as intra-population crosses of the sire population. About 20% of the male progeny of melanic sires express the wild-type phenotype. These silver F1 males sire only silver offspring, suggestive of loss of the melanin gene in F1 males from crossover between sex chromosomes, or control by additional modifiers, or involvement of additional factors. In nature, melanic males persist at very low frequencies. The data collected here on heritability indicate that genetic factors contribute to the rarity of melanic male mosquitofish

Relationships and Mental Health: A Qualitative Perspective of Individuals within the Transgender Community

Trans individuals as a population are more likely to endure the effects of depression, anxiety, suicidal ideations as well as discrimination, violence, and traumatic experiences compared to the general population. To begin to understand these experiences, five trans women participated in this study in order to explore their mental health symptoms with the quality of their relationships with their family, friends, partners, and within the community, specifically counselors. As a result, participants grounded their identity in their religious or spiritual beliefs in order to counter their families’ dismissal of their identity. Participants disclosed the nature of their experiences regarding the pressure to meet societal expectations, dealing with their mental health, trauma, and social isolation as their identity development progressed. Implications for counseling are discussed as it relates to building resiliency and using the counseling relationship as a beginning to establish support

A Genetically Distinct Hybrid Zone Occurs for Two Globally Invasive Mosquito Fish Species with Striking Phenotypic Resemblance

Hybrid zones allow for the investigation of incipient speciation and related evolutionary processes of selection, gene flow, and migration. Interspecific dynamics, like competition, can impact the size, shape, and directional movement of species in hybrid zones. Hybrid zones contribute to a paradox for the biological species concept because interbreeding between species occurs while parental forms remain distinct. A long‐standing zone of intergradation or introgression exists for eastern and western mosquito fish (Gambusia holbrooki and G. affinis) around Mobile Bay, AL. The region has been studied episodically, over decades, making it perfect for addressing temporal dynamics and for providing a deeper understanding of the genetics of these periodically reclassified fishes (as species or subspecies). We used six microsatellite markers to assess the current population structure and gene flow patterns across 19 populations of mosquito fish and then compared our results with historical data. Genetic evidence demonstrates that the current hybrid zone is located in a similar geographic region as the historical one, even after three decades. Hybrid fish, however, demonstrate relatively low heterozygosity and are genetically distinct from western and eastern mosquito fish populations. Fin ray counts, sometimes used to distinguish the two species from one another, demonstrate more eastern (G. holbrooki) phenotype fish within the molecular genetic hybrid zone today. Mosquito fish are globally invasive, often found on the leading edge of flooded waters that they colonize, so the impact of hurricanes in the wake of climate change was also evaluated. An increase in the frequency and intensity of hurricanes in the hybrid region has occurred, and this point warrants further attention since hurricanes are known to move these aggressive, invasive species into novel territory. This work contributes to our classical understanding of hybrid zone temporal dynamics, refines our understanding of mosquito fish genetics in their native range, evaluates important genotype–phenotype relationships, and identifies a potential new impact of climate change

Heritable Melanism and Parasitic Infection Both Result in Black-Spotted Mosquitofish

Male Gambusia holbrooki (Eastern Mosquitofish) express a heritable pigmentation polymorphism: ≈99% of males are silver, and only ≈1% have a melanic, black-spotted pattern. Sex-linkage, an autosomal modifier, and temperature control the expression of this heritable melanism. In many teleosts, melanin also accumulates around the site of parasitic invasion. We have identified black-spot disease in wild mosquitofish from their native habitat. Here, we demonstrate convergence upon the black-pigmented phenotype through two means: 1) heritable melanism, and 2) melanic spotting on the silver genotype that results from infection with immature encysted trematodes. Females are silver and express greater avoidance ofmelanic males during mating attempts. The resemblance of the black-spotted pattern of the melanic genotype to that of silver genotype infected with trematodes may affect the fitness ofmelanic males if females perceive them as diseased. Alternatively, females may shun parasitized silverfish because they resemble the melanic genotype, which is larger and has a larger mating orga

A Recommended New Approach on Motorization Ratio Calculations of Stepper Motors

Stepper motors are widely used on most spacecraft mechanisms requiring repeatable and reliable performance. The unique detent torque characteristics of these type of motors makes them behave differently when subjected to low duty cycle excitations where the applied driving pulses are only energized for a fraction of the pulse duration. This phenomenon is even more pronounced in discrete permanent magnet stepper motors used in the space industry. While the inherent high detent properties of discrete permanent magnets provide desirable unpowered holding performance characteristics, it results in unique behavior especially in low duty cycles. Notably, the running torque reduces quickly to the unpowered holding torque when the duty cycle is reduced. The space industry's accepted methodology of calculating the Motorization Ratio (or Torque Margin) is more applicable to systems where the power is continuously applied to the motor coils like brushless DC motors where the cogging torques are low enough not to affect the linear performance of the motors as a function of applied current. This paper summarizes the theoretical and experimental studies performed on a number of space qualified motors under different pulse rates and duty cycles. It is the intention of this paper to introduce a new approach to calculate the Motorization Ratios for discrete permanent magnet steppers under all full and partial duty cycle regimes. The recommended approach defines two distinct relationships to calculate the Motorization Ratio for 100 percent duty cycle and partial duty cycle, when the motor detent (unpowered holding torque) is the main contributor to holding position. These two computations reflect accurately the stepper motor physical behavior as a function of the command phase (ON versus OFF times of the pulses), pointing out how the torque contributors combine. Important points highlighted under this study are the torque margin computations, in particular for well characterized mechanisms. The rationale at CDR level versus TRR/TRB level will be discussed, aiming at avoiding too much conservatism for units that have extensive test and in flight heritage. A critical topic is related to the magnetic losses and how to sort out such phenomena as a function of the motor type being used. For instance, detent torque is a major contributor that has no reason to evolve during life and is not an uncontrolled torque loss

Dire et montrer l'horreur : le sublime par l'ekphrasis au service du fantastique chez H.P. Lovecraft

L’étude de l’œuvre de l’auteur fantastique américain H.P. Lovecraft a souvent été mise de côté dans les études littéraires, où on qualifiait son style d’excessif et maladroit. Celui-ci a alimenté beaucoup de débats sur l’appartenance de Lovecraft au genre fantastique en général, duquel on l’excluait, prétextant qu’il rompait la traditionnelle hésitation typiquement fantastique. Dans ce mémoire, nous souhaitons nous interroger sur le rôle que peut jouer l’écriture particulière de Lovecraft dans la construction d’un univers narratif cohérent, malgré la crise du signe à laquelle font face ses personnages. Nous observerons comment l’écriture de Lovecraft, grâce à son recours à l’ekphrasis, parvient à susciter le sublime, d’abord chez ses narrateurs, mais également transcender le récit pour atteindre le lecteur. Nous montrerons comment le sublime vécu par ses personnages parvient, grâce à une esthétique de la présence du surnaturel, à faire douter le lecteur sur sa propre réalité

La conception de l'éthique dans le cadre du programme ministériel de formation à l'enseignement et dans la pratique d'enseignants au secondaire : une étude comparative

L'objet de notre mémoire tente de cerner ce qu'est l'éthique en éducation et dans quelle mesure la conception de l'éthique chez les enseignants du milieu scolaire rejoint celle de documents gouvernementaux qui traitent de la « compétence » éthique, plus précisément celle du nouveau programme, intitulé La formation à l'enseignement. Les orientations. Les compétences professionnelles (MÉLS, 2001a). Pour résoudre cette problématique, nous avons organisé un entretien de groupe de recherche formé d'enseignants au secondaire et nous avons analysé les données recueillies à l'aide de textes appartenant à la littérature concernée par le sujet. ______________________________________________________________________________ MOTS-CLÉS DE L’AUTEUR : Compétence, Compétence éthique, Éducation, Enseignement, Éthique, Formation des maîtres, Programme de formation à l'enseignement

Biologically meaningful expression profiling across species using heterologous hybridization to a cDNA microarray

BACKGROUND: Unravelling the path from genotype to phenotype, as it is influenced by an organism's environment, is one of the central goals in biology. Gene expression profiling by means of microarrays has become very prominent in this endeavour, although resources exist only for relatively few model systems. As genomics has matured into a comparative research program, expression profiling now also provides a powerful tool for non-traditional model systems to elucidate the molecular basis of complex traits. RESULTS: Here we present a microarray constructed with ~4500 features, derived from a brain-specific cDNA library for the African cichlid fish Astatotilapia burtoni (Perciformes). Heterologous hybridization, targeting RNA to an array constructed for a different species, is used for eight different fish species. We quantified the concordance in gene expression profiles across these species (number of genes and fold-changes). Although most robust when target RNA is derived from closely related species (<10 MA divergence time), our results showed consistent profiles for other closely related taxa (~65 MA divergence time) and, to a lesser extent, even very distantly related species (>200 MA divergence time). CONCLUSION: This strategy overcomes some of the restrictions imposed on model systems that are of importance for evolutionary and ecological studies, but for which only limited sequence information is available. Our work validates the use of expression profiling for functional genomics within a comparative framework and provides a foundation for the molecular and cellular analysis of complex traits in a wide range of organisms

La reconnaissance au Québec de la rechute, récidive ou aggravation psychologique découlant d'une lésion professionnelle de nature physique

Il n'est pas rare qu'un travailleur qui est victime d'une lésion professionnelle physique éprouve des problèmes psychologiques en raison des conséquences de cette lésion. Dans certains cas, il pourra se faire reconnaitre une rechute, récidive ou aggravation de sa condition et avoir droit aux prestations prévues par la Loi sur les accidents du travail et les maladies professionnelles. Toutefois, une pathologie psychologique est généralement multifactorielle, c'est-à-dire qu'elle est habituellement provoquée par plusieurs facteurs simultanés, certains étant indemnisables, alors que d'autres non. Par conséquent, il peut être difficile pour un tribunal de départager les facteurs ayant le plus d'importance dans le développement de la lésion psychologique du travailleur selon la preuve au dossier. Ainsi, l'appréciation du lien de causalité entre rechute, récidive ou aggravation psychologique et la lésion physique initiale s'avère une tâche ardue pour un décideur et le résultat de sa décision est généralement imprévisible pour les parties. Le but de ce mémoire consiste donc à proposer une liste de critères permettant aux juges administratifs, aux parties et à leurs représentants de faciliter leur analyse quant au lien de causalité entre une lésion professionnelle de nature physique et une rechute, récidive ou aggravation de nature psychologique. Pour ce faire, nous avons analysé 75 décisions rendues entre le 20 mai 2012 et le 20 mai 2016 par la Commission des lésions professionnelles et par le tribunal qui l'a remplacée, le Tribunal administratif du travail. Cette analyse a permis de cibler 11 critères qui pourront servir de guide ou d'outils dans l'appréciation de la preuve afin de se prononcer sur le bien-fondé de ce type de réclamation. Parmi ces critères nous retrouvons, notamment, les facteurs de stress concomitants aux premiers symptômes psychologiques, les opinions médicales motivées, les conditions physiques personnelles qui pourraient influencer la condition psychologique du travailleur, la gravité objective des conséquences de la lésion physique, etc. Par le fait même, cette recherche a permis de dresser l'état actuel du droit sur les rechutes récidives ou aggravations psychologiques et de vérifier, dans une moindre mesure, si certains critères extérieurs à la sphère juridique peuvent influencer la décision du juge administratif, comme la présence d'un assesseur médical, le sexe du travailleur ou de la travailleuse, etc.\ud ____________________________________________________________________________\ud MOTS-CLÉS DE L’AUTEUR : Rechute, récidive ou aggravation psychologique, lésion professionnelle; lien de causalité; critères; élément de preuve; fardeau de la preuve; crâne fragile; cohérence décisionnelle; Québec