Spin rate and seam orientation as visual cues in baseball

This study investigated the viability of baseball spin direction and seam orientation as visual cues in predicting the flight path of pitched baseballs and thus increasing hitting accuracy. Ten male Optometry students served as subjects. Using an instrument designed to minimize all visual cues associated with a simulated pitched baseball aside from spin direction and seam orientation, the subjects viewed a striped ball with three possible seam orientations at varying spin rates. Viewing distance, time, and stripe size were chosen to closely simulate the parameters of professional pitches. Results indicated that subjects were able to accurately resolve the stripe orientation and spin direction at an average maximum spin rate of 490 RPM, with a range of resolvable spin rates between 355-800 RPM. As professional fastball spin rates vary between approximately 1500-1800 RPM, we have concluded that the visual systems of average young healthy males are not capable of resolving seam orientation and spin direction of professional fastball pitches. Further studies testing professional or high level amateur baseball players are required to determine the viability of using these visual cues as a training technique to improve hitting percentage

Projections des ménages selon la taille : Une méthode applicable au Québec

Nous désirons élaborer des perspectives de ménages qui serviront pour une étude des besoins de logements. Il fallait donc inclure dans nos résultats la caractéristique de la taille des ménages. La méthode des rapports aurait pu être utilisée en extrapolant les pourcentages des ménages selon le nombre de personnes. Ceci s’avérait trop complexe à manipuler. Nous avons donc cherché une méthode simple d’extrapolation. Une méthode mise au point par M.F. BAMAS et N. TRIBALLAT1 a déjà été vérifiée en France, et elle s’est avérée suffisamment juste pour être utilisée comme méthode de projection des ménages selon la taille. Nous avons donc vérifié cette méthode pour le Québec, ses quasi-régions administratives et ses principales villes.La méthode qui reconstitue la distribution des ménages selon la taille à partir de deux paramètres (moyenne et variance de la distribution), s’est avérée suffisamment fidèle aux observations des recensements antérieurs pour être applicable au Québec. Nous avons cependant noté un problème pour les ménages de taille 2 et 3. Un ajustement a posteriori semble résoudre ce problème d’incohérence entre les observations des recensements et la distribution théorique.Cette méthode d’ajustement statistique nous permettra d’obtenir la ventilation du nombre des ménages selon la taille en faisant une hypothèse sur les paramètres du modèle : la moyenne et la variance de la distribution des ménages selon la taille. La moyenne sera connue pour les années futures (étant un résultat intermédiaire de nos perspectives par la méthode des taux de chefs); il n’y aura plus qu’à extrapoler les valeurs de la variance.Cette méthode sera utile en ce sens qu’elle simplifie de beaucoup les étapes de calculs et d’extrapolations complexes où les risques d’erreur se multiplient. (1) M.F. BAMAS et N. TRIBALLAT, "Perspectives de ménages par nombre de personnes, essais méthodologiques", in Etude et Conjoncture, Vol. 22, no 12, Décembre 1967, pp. 3-24

Chickadees Faced with Unpredictable Food Increase Fat Reserves but Certain Components of Their Immune Function Decline

In winter, temperate resident birds are often faced with periodic low natural food availability. This reduction or unpredictability in resource availability might then have a negative impact on immune function, given that immune system support is highly resource dependent. We investigated the balance between energetic and immune management in captive black-capped chickadees (Poecile atricapilus) by manipulating the predictability of resources. The control group received food ad lib. every day, while the experimental group received a reduced amount of food on random days and food ad lib. on all other days. We measured two key metrics of energetic management (body and fat mass) as well as a suite of immune system components. Compared with control birds, experimental birds maintained significantly higher total body and fat mass, had lower acute phase protein concentrations, and had decreased body temperature and lost more body mass during the fever response following injection with lipopolysaccharides. Interestingly, birds in both groups had similar levels of complement lysis, delayed-type hypersensitivity response (phytohemagglutinin), and primary antibody production (keyhole limpet hemocyanin). This experiment demonstrates that black-capped chickadees strategically increase their fat mass in response to decreased food availability and that this might allow the birds to maintain most of the immune system unaltered, except some of the most costly immune components

Chickadees faced with unpredictable food increase fat reserves but certain components of their immune function decline

In winter, temperate resident birds are often faced with periodic low natural food availability. This reduction or unpredictability in resource availability might then have a negative impact on immune function, given that immune system support is highly resource dependent. We investigated the balance between energetic and immune management in captive black-capped chickadees (Poecile atricapilus) by manipulating the predictability of resources. The control group received food ad lib. every day, while the experimental group received a reduced amount of food on random days and food ad lib. on all other days. We measured two key metrics of energetic management (body and fat mass) as well as a suite of immune system components. Compared with control birds, experimental birds maintained significantly higher total body and fat mass, had lower acute phase protein concentrations, and had decreased body temperature and lost more body mass during the fever response following injection with lipopolysaccharides. Interestingly, birds in both groups had similar levels of complement lysis, delayed-type hypersensitivity response (phytohemagglutinin), and primary antibody production (keyhole limpet hemocyanin). This experiment demonstrates that black-capped chickadees strategically increase their fat mass in response to decreased food availability and that this might allow the birds to maintain most of the immune system unaltered, except some of the most costly immune components

Teacher working : conditions in Alberta during the Klein regime

77 leaves ; 29 cm. --The thrust of this research project was to examine how educational reform in Alberta, under the Klein regime, has affected teacher workloads and morale. The first section of this project establishes a political context and examines how the Klein government's neoconservative ideology has permeated educational discourse, policy and reform. The second section is the interview portion of the study and is designed to help the reader gain a better understanding of current teacher working conditions in the province of Alberta. The inquiry adopted a qualitative approach and the data was collected through semistructured interviews. The research will show that educational reform in Alberta is more about balancing budgets and eliminating deficits, in view of competing in the global marketplace, rather than improving the quality of education for students. The research will also attempt to show that the alleged crisis in public education was artificially created to orchestrate a massive and unprecedented restructuring of public education in Alberta

What do Canadian managers do : a study of their roles, views, and perspectives

x, 73 leaves ; 29 cm.This study presents a different perspective that strives to achieve a better understanding of “What do managers do.” The present work divides the role of a manager in two major ways: 1) through an analysis of the characteristics of successful and effective managers; and 2) through an assessment of the different attitudes and perspectives of Canadian managers. The data were collected from a sample of 186 Canadian managers in which the participants completed a paper and pencil questionnaire. The data were analyzed using both descriptive and inferential statistics. A major finding from this study was that successful Canadian managers used multiple roles including human resource management, traditional management, and networking whereas effective managers used predominantly the human resource management role. As well, the issues of professionalism and unionization stood out for this sample of Canadian managers

Early life neonicotinoid exposure results in proximal benefits and ultimate carryover effects

Neonicotinoids are insecticides widely used as seed treatments that appear to have multiple negative effects on birds at a diversity of biological scales. Adult birds exposed to a low dose of imidacloprid, one of the most commonly used neonicotinoids, presented reduced fat stores, delayed migration and potentially altered orientation. However, little is known on the effect of imidacloprid on birds growth rate despite studies that have documented disruptive effects of low imidacloprid doses on thyroid gland communication. We performed a 2 × 2 factorial design experiment in Zebra finches, in which nestling birds were exposed to a very low dose (0.205 mg kg body mass - 1) of imidacloprid combined with food restriction during posthatch development. During the early developmental period, imidacloprid exposure resulted in an improvement of body condition index in treated nestlings relative to controls. Imidacloprid also led to compensatory growth in food restricted nestlings. This early life neonicotinoid exposure also carried over to adult age, with exposed birds showing higher lean mass and basal metabolic rate than controls at ages of 90–800 days. This study presents the first evidence that very low-dose neonicotinoid exposure during early life can permanently alter adult phenotype in birds

MUC1 alters oncogenic events and transcription in human breast cancer cells

INTRODUCTION: MUC1 is an oncoprotein whose overexpression correlates with aggressiveness of tumors and poor survival of cancer patients. Many of the oncogenic effects of MUC1 are believed to occur through interaction of its cytoplasmic tail with signaling molecules. As expected for a protein with oncogenic functions, MUC1 is linked to regulation of proliferation, apoptosis, invasion, and transcription. METHODS: To clarify the role of MUC1 in cancer, we transfected two breast cancer cell lines (MDA-MB-468 and BT-20) with small interfering (si)RNA directed against MUC1 and analyzed transcriptional responses and oncogenic events (proliferation, apoptosis and invasion). RESULTS: Transcription of several genes was altered after transfection of MUC1 siRNA, including decreased MAP2K1 (MEK1), JUN, PDGFA, CDC25A, VEGF and ITGAV (integrin α(v)), and increased TNF, RAF1, and MMP2. Additional changes were seen at the protein level, such as increased expression of c-Myc, heightened phosphorylation of AKT, and decreased activation of MEK1/2 and ERK1/2. These were correlated with cellular events, as MUC1 siRNA in the MDA-MB-468 line decreased proliferation and invasion, and increased stress-induced apoptosis. Intriguingly, BT-20 cells displayed similar levels of apoptosis regardless of siRNA, and actually increased proliferation after MUC1 siRNA. CONCLUSION: These results further the growing knowledge of the role of MUC1 in transcription, and suggest that the regulation of MUC1 in breast cancer may be more complex than previously appreciated. The differences between these two cell lines emphasize the importance of understanding the context of cell-specific signaling events when analyzing the oncogenic functions of MUC1, and caution against generalizing the results of individual cell lines without adequate confirmation in intact biological systems