Doctor of Philosophy / Curriculum and Instruction Programs / Steven R. Harbstreit / There has been little research conducted related to the National FFA Alumni Association since its establishment in 1971. The purposes of this study were to determine the demographic characteristics of the membership of the National FFA Alumni Association, determine whether differences exist regarding members’ motivation to join and engage themselves in the local FFA Alumni affiliate, and whether differences exist in members’ loyalty to the FFA Alumni at the national and local levels based on their level of engagement. This descriptive study utilized survey research to accomplish the purpose, assessing the motivational functions for volunteering and measuring loyalty to the local FFA Alumni affiliate and the National FFA Alumni Association. The population of this study was the membership of the National FFA Alumni Association for the 2009-2010 membership year (N = 49,589). A proportional stratified random sample (n = 1,000) was used to identify study participants and ensure representation from the four membership regions of the National FFA Alumni Association. Based on a final usable sample (n = 913), the researcher obtained a final response rate of 43.7% (n = 399). The National FFA Alumni Association is comprised of predominantly white, male, college-educated, actively engaged former FFA members with an average age of 49.6 years. The results of independent sample t-tests indicated a significant difference between male and female members in the importance they place on six motivations for volunteering. Female members were considerably higher in the motivational functions of values, understanding, enhancement, social, career, and protective. A correlation analysis also indicated that age of the respondents played a role in the motivation to volunteer. Older members were less motivated in the areas of career, understanding, values, and enhancement. Paired samples t-tests determined members were significantly more loyal to the local FFA Alumni affiliate than the National FFA Alumni Association. There was also a significant difference in the loyalty of members based on their level of engagement with a local FFA Alumni affiliate with more highly engaged members expressing more loyalty to the association.

No description available.

Synchronized oscillations of ensembles of neurons in the brain underlie human cognition and behaviors. Neuronal network oscillations can be described by the physics of coupled dynamical systems. This dissertation examines the dynamic network activities in two distinct neurocognitive networks, the salience network (SN) and the ventral temporal cortex-dorsolateral prefrontal cortex (VTC-DLPFC) network, during perceptual decision-making (PDM). The key nodes of the SN include the right anterior insula (rAI), left anterior insula (lAI), and dorsal anterior cingulate cortex (dACC) in the brain. When and how a sensory signal enters and organizes within the SN before reaching the central executive network including the prefrontal cortex has been a mystery. Second, prior studies also report that perception of visual objects (face and house) involves a network of the VTC—the fusiform face area (FFA) and para-hippocampal place area (PPA)—and the DLPFC. How sensory information enters and organizes within the VTC-DLPFC network is not well understood, in milliseconds time-scale of human’s perception and decision-making. We used clear and noisy face/house image categorization tasks and scalp electroencephalography (EEG) recordings to study the dynamics of these networks. We demonstrated that beta (13–30 Hz) oscillation bound the SN, became most active around 100 ms after the stimulus onset, the rAI acted as a main outflow hub within the SN, and the SN activities were negatively correlated with the difficult tasks. We also uncovered that the VTC-DLPFC network activities were mediated by beta (13-30 Hz) and gamma (30-100 Hz) oscillations. Beta activities were enhanced in the time frame 125-250 ms after stimulus onset, the VTC acted as main outflow hub, and network activities were negatively correlated with the difficult tasks. In contrast, gamma activities were elevated in the time frame 0-125 ms, the DLPFC acted as a main outflow hub, and network activities—specifically the FFA-PPA pair—were positively correlated with the difficult tasks. These findings significantly enhance our understanding of how sensory information enters and organizes within the SN and the VTC-DLPFC network, respectively in PDM.

No description available.

<div>The purpose of this research was to develop and validate an instrument designed to assess programming of youth development organizations. The instrument can be used by leaders of youth development organizations to monitor the organization’s performance in developing productive and engaged citizens. This research viewed youth development organizations as a microsystem that youth interact with (Bronfenbrenner & Morris, 2006). A complete review of the literature on youth development organizations was conducted to determine the components of positive youth development organizations. The resulting conceptual framework consisted of project, skills and knowledge, community contribution, high-density experiences, environment, non-parental adult, and near-peer role models.</div><div><br></div><div>An item pool was developed based on the literature available on youth development organization programming. This item pool was reviewed by experts in youth development organization programming and inclusion. Then the items were entered into two tools to assess grammar and concise language. Third, the items were administered to a small sample then analyzed for correlations and contributions to reliability. Items were eliminated if they correlated too highly with other items and if they did not contribute to the reliability of the scale. Fourth, the items were administered to a broader sample and correlations and reliability measures were analyzed again with more items removed. Finally, the items were administered to another sample and analyzed for multicollinearity and reliability. The final sample took the survey a second time and responses were compared based on paired t-tests to establish test-retest reliability.<br></div><div><br></div><div>The 15-item instrument exhibits appropriate measures of validity and reliability to recommend its usage by youth development organization leaders to evaluation programming. The instrument is parsimonious so leaders can add program-specific questions while avoiding participant fatigue. A complete version of the instrument is available in the appendices.</div>

Die therapeutische Beeinflußbarkeit einer Leberverfettung gilt weltweit als unbefriedigend ge-löst, so daß ein letaler Ausgang besonders bei Wiederkäuern teilweise nicht zu verhindern ist. Die Nutzung von beta-Rezeptorenblockern hat bisher mit dieser Indikation keinen Eingang in die Veterinärmedizin gefunden. In den vorliegenden Untersuchungen wurden deshalb die Auswirkungen einer unspezifischen Blockade der beta-adrenergen Rezeptoren auf die Lipolyse, die klinischen und hämatologi-schen Funktionen sowie Leber-, Eiweiß- und Mineralstoffwechsel bei fastenden Schafen ge-prüft. Insbesondere wurde dabei die Wirkung einer Propranololapplikation auf die Lipolyse in der frühen Phase des Fastens untersucht. Zu diesem Zweck wurden insgesamt 15 weiblichen, klinisch gesunden, güsten Schafen der Rasse Merino-Fleisch während eines dreitägigen Futterentzuges mit Hilfe einer Dauertropfinfu-sion mit zwei 8stündigen Pausen 0,5 bzw. 1 mg Propranolol/kg KM/d bzw. den Tieren der Kontrollgruppe ein vergleichbares Volumen einer NaCl-Lösung appliziert. Neben der klini-schen Kontrolle von Puls- und Atemfrequenz, Körpertemperatur und Pansenaktivität erfolgte über die wiederholte Gewinnung von Blutproben aus der Vena jugularis externa eine Erfassung der Konzentrationen von Glucose, FFS, Bilirubin, BHB, K, Na, Mg, Gesamteiweiß und Albu-min im Blutserum. Zur Kontrolle der Leberfunktion wurden die Aktivitäten der GLDH und ASAT bestimmt. Die Wirkung des beta-Rezeptor-Antagonisten Propranolol auf die hämatolo-gischen Parameter wurde durch die Kontrolle der Leukozyten-, Erythrozyten- und Hämoglo-binkonzentrationen und den Hämatokrit der Schafe im Versuchsverlauf überprüft. In Übereinstimmung mit bisherigen Untersuchungen an Wiederkäuern und Nichtwiederkäuern kam es aufgrund der dreitägigen Futterdeprivation in allen Tiergruppen zu einer signifikanten Verminderung des Körpergewichtes um bis zu 9,8 %. Die Zahl der Pansenbewegungen redu-zierte sich bei allen Tieren signifikant bereits innerhalb der ersten 48 Stunden der Futterdepri-vation. Der stärkste Abfall der Pansenaktivität ließ sich bei den Schafen, denen 1 mg Propra-nolol/kg KM/d infundiert wurde, nachweisen. Puls- und Atemfrequenz, die Konzentrationen von Na, K, Mg, Gesamteiweiß und Albumin sowie die Aktivitäten von GLDH und ASAT im Blutserum blieben im Versuchsverlauf ohne signifikante Veränderungen. Eine Beeinflussung der hämatologischen Parameter ließ sich we-der bei den Schafen der Kontrollgruppe noch bei denen der Versuchsgruppen nachweisen. Während der Futterentzug in allen Tiergruppen zu einer tendenziellen Abnahme der Blut-serumkonzentration an Glucose führte, stiegen die Konzentrationen an FFS, Bilirubin und BHB im Blutserum aller Tiere an. Damit weisen die Veränderungen in den Konzentrationen von FFS, BHB und Bilirubin im Blutserum der Schafe der Kontrollgruppe die typischen Merkmale einer Fastenstoffwechsellage auf. In beiden Versuchsgruppen fielen diese Konzen-trationserhöhungen gegenüber denen der Kontrollgruppe statistisch gesichert niedriger aus. Unter Berücksichtigung der dabei erreichten Niveaus ließ sich für die Versuchsgruppen eine geringere Belastung von Energie- und Leberstoffwechsel als in der Kontrollgruppe feststellen. Der Übergang von der ersten in die zweite Phase des Fastenstoffwechsels ist in allen Tiergrup-pen, besonders deutlich in beiden Versuchsgruppen, zum Zeitpunkt um 48 h nach Versuchsbe-ginn an der Erhöhung der Körpertemperatur sowie den stärkeren Anstiegen der FFS-Konzentrationen erkennbar. Die besondere klinische und labordiagnostische Bedeutung der Änderungen der FFS-Konzentration im Blutserum zeigte sich in der zeitlich früheren und ausgeprägteren Reaktion als die Konzentrationsänderungen von Bilirubin und BHB. Bereits nach 24stündigem Fasten waren in allen Schafgruppen signifikant gegenüber den Ausgangswerten erhöhte FFS-Konzentrationen nachweisbar. In beiden Versuchsgruppen war bis zum Erreichen der Maxi-malwerte 48 h nach Beginn des Fastens ein geringerer Anstieg der FFS-Konzentration im Blut-serum als in der Kontrollgruppe nachzuweisen. Nach dem Erreichen der Maximalkonzentration kam es unter dem Propranololeinfluß in beiden Versuchsgruppen zu einem raschen, signifi-kantem Abfall der FFS-Konzentration um 44,7 bzw. 63,5 %. Die Abnahme der FFS-Konzentration im Blutserum vom Maximalwert bis zum Versuchsende betrug in der Kontroll-gruppe lediglich 8,6 %. und lag damit signifikant unter den Vergleichswerten der Versuchstie-re. Für die Konzentration der FFS fanden sich zum Versuchsende zwischen allen Gruppen si-gnifikante Unterschiede. Damit läßt sich eine dosisabhängige Wirkung einer Propranololappli-kation auf die Freisetzung von FFS aus den körpereigenen Fettdepots ableiten. Als Besonderheit war zu beobachten, daß sich die Konzentration der FFS in der Kontrollgrup-pe in den Zeiträumen der Infusion der NaCl-Lösung vermindert. Möglicherweise spielt hierbei der säuernde Einfluß des NaCl auf den pH-Wert im Blut eine Rolle. Unter dem Einfluß einer pH-Verminderung kommt es dabei zu einer Absenkung der Lipolyserate. Der zwischen den Infusionszeiten starke Konzentrationsanstieg der FFS in der Kontrollgruppe führt in dieser zu signifikant höheren FFS-Konzentrationen als in den Versuchsgruppen. Die Konzentrationsänderungen von direkt reagierendem und Gesamtbilirubin fielen bei den Schafen der Kontrollgruppe höher aus als bei den Tieren der Versuchsgruppen. Während die Maximalkonzentrationen für das Gesamtbilirubin in den Versuchsgruppen mit Dosierungen von 0,5 bzw. 1 mg Propranolol/kg KM/d 48 h nach Versuchsbeginn erreicht werden, ließen sich die maximalen Gesamtbilirubinkonzentrationen in der Kontrollgruppe erst 56 h nach Versuchsbe-ginn nachweisen. Die dabei vorhandenen Konzentrationsunterschiede zwischen den einzelnen Gruppen weisen auf eine geringere Belastung der Leber bei den Schafen der Versuchsgruppen hin. Auch die BHB-Konzentrationen im Blutserum der Schafe der Versuchsgruppen lagen zum Versuchsende unter denen der Tiere in der Kontrollgruppe. Damit liegt ein weiterer Indikator auf eine geringere Leberbelastung der Tiere in den Versuchsgruppen gegenüber den Schafen der Kontrollgruppe vor. Die absolut niedrigsten BHB-Konzentrationen waren bei den Schafen der Versuchsgruppe mit einer Propranololgabe von 1 mg/kg KM/d nachweisbar. In dieser Gruppe wurde die maximale BHB-Konzentration 32 h nach Fastenbeginn erreicht. Die vorliegenden Ergebnisse zeigen, daß sich mit Propranololgaben in Höhe von 0,5 bzw. 1 mg/kg KM/d beim Schaf eine Hemmung der Lipolyse innerhalb der ersten 64 Stunden eines Futterentzuges erreichen läßt, ohne dabei nachweisbaren Einfluß auf hämatologische Parameter auszuüben. Insbesondere weisen die zwischen Versuchs- und Kontrollgruppe vergleichbaren Anstiege der FFS-Konzentrationen in den infusionsfreien Zeiträumen auf den Einfluß des beta-adrenergen Antagonisten auf die Lipolyse während der Infusion hin. Die Konzentrationsände-rungen von Bilirubin und BHB in den Versuchsgruppen erfolgen in deutlich geringerem Um-fang als in der Kontrollgruppe. Damit läst sich auf eine geringere Belastung von Energie- und Leberstoffwechsel bei den Versuchstieren schließen. Die nicht signifikanten Veränderungen der Enzymaktivitäten von GLDH und ASAT bestätigen, daß durch die Anwendung von Propra-nolol keine negative Beeinflussung der Leberfunktion erfolgt. Aufgrund der stärkeren Reduzie-rung der Zahl der Pansenbewegungen und des verminderten Konzentrationsanstieges von FFS im Blutserum der Schafe, denen 1 mg Propranolol/kg KM/d appliziert wurde, gegenüber denen die 0,5 mg Propranolol/kg KM/d erhielten, ist von einer Dosisabhängigkeit der Propranolol-wirkung auszugehen. Die Applikation von Propranolol in einer Dosis von 0,5 bzw. 1 mg/kg KM/d stellt beim Schaf eine geeignete Methode dar, frühzeitig eine Verminderung der fasten-induzierten Lipolyse zu erreichen. / The treatment of the fatty liver disease is world-wide regarded as unsatisfactory, so that death of the affected ruminants is partly unavoidable. The administration of beta receptor blockers in such cases has not found its way into veterinary medicine until now. In this study, the effects of a nonspecific blockade of the beta adrenoceptors on lipolysis, clinical and hematological parameters as well as on the metabolism of the liver, proteins and minerals in fasting sheep were therefore tested. Especially, the effect of a Propranolol administration on the lipolysis in the early stage of fasting was examined. During a three-day period of food deprivation, 15 female, clinically healthy and non-pregnant sheep (Merino-Fleisch) were given 0.5 or 1 mg Propranolol/kg body weight per day via a continuous infusion with two interruptions of eight hours. During the experiment, pulse, respiration rate, body temperature and rumen activity were checked. The serum concentrations of glucose, FFA, bilirubin, beta-hydroxybutyrate, potassium, sodium, magnesium, total protein and albumin were controlled by repeatedly taking blood samples from the vena jugularis externa. The activity of the enzymes GLDH and AST were determined to check the liver function. The effect of the beta-receptor antagonist Propranolol on the hematological parameters was checked by examining the WBC, RBC, the hemoglobin concentrations and the packed cell volume. All test groups showed significant decrease in body weigth of up to 9.8 %, due to the three-day food deprivation. Even within the first 48 hours of food deprivation, rumen motility of all animals was decreasing significantly. Those sheep which received 1 mg Propranolol/kg body weight per day showed the strongest decrease in rumen activity. Pulse and respiration rate, the concentrations of potassium, sodium, magnesium, total protein and albumin as well as the activity of GLDH and AST in blood serum remained without significant changes during the experiment. Neither the sheep of the control group nor those of the experimental groups showed any influence on the hematological parameters. While the blood glucose concentration tended to be lower during the food deprivation in all groups, the concentrations of FFA, bilirubin and beta-hydroxybutyrate in blood serum were increasing. Thus, the changes of FFA, bilirubin and beta-hydroxybutyrate concentrations in the control group showed the typical characteristics of fasting metabolism. These absolute increases in concentrations were significantly lower in both experimental groups than those in the control group. With regard to the levels reached and compared to the control group, a smaller load of energy and liver metabolism could be determined in the experimental groups. The transition from the first to the second stage of the fasting metabolism in all groups (but especially in the experimental groups) was clearly discernible in the rises of body temperature and in the stronger increases of the FFA concentrations approximately 48 hours after the experiment started. The special clinical and diagnostic importance of the FFA concentration was indicated in an earlier and stronger change of the FFA concentration in the blood serum, compared to the changes of bilirubin and beta-hydroxybutyrate. As early as 24 hours after the beginning of the fasting, a significant rise of the FFA concentration in comparison to the initial concentration could be proved. In contrast to the control group the two experimental groups showed a smaller increase in the FFA concentration. All groups reached their maxima of FFA concentration 48 hours after the beginning of the experiment. Afterwards FFA concentrations in the two experimental groups were sinking fast and significantly by 44.7 % and 63.5 % respectively. In the control group, the decrease of the FFA concentration from the maximum until the end of the experiment was only 8.6 % and thus significantly lower than the comparative results. At the end of the experiment, significant differences in FFA concentrations between all groups could be proved. So, it can be assumed that there is a dose-dependent effect of Propranolol on the FFA release from the bodyŽs own fat depots. The FFA concentration in the control group was decreasing during the NaCl-infusion. This could be due to NaClŽs influence on the pH value of the blood. The reduction of the pH causes a decreasing rate of the lipolysis. The strong rise of FFA concentration between the infusion in the control group, lead to significantly higher results compared to the experimental groups. The changes of total and direct reacting bilirubin in the control group were higher than in the experimental groups. While maximum concentrations of total bilirubin acid in the experimental groups (which got 0.5 and 1 mg Propranolol/kg body weigth per day respectively) could be determined 48 hours after the experimentŽs start, maximum concentrations in the control group could be found only 56 hours after beginning of the fasting. Beta-hydroxybutyrate concentrations in the experimental groups were also lower than in the control group. These differences between the groups indicate a smaller strain of the liver in the experimental groups. The lowest beta-hydroxybutyrate concentrations could be proved in the experimental group with a dose of 1 mg Propranolol/kg body weight per day. In this group, the maximum beta-hydroxybutyrate concentration was reached 32 hours after the beginning of the fasting. These results suggest that by the administration of Propranolol at doses of 0.5 mg and 1 mg/kg body weigth per day respectively it is possible to inhibit the lipolysis within the first 64 hours after a food deprivation without effecting the hematological parameters. Particularly, the comparable increases in FFA concentrations in the experimental and control groups between the infusions indicate a direct effect of the beta-adrenergic antagonist on the lipolysis during the infusions. The changes of bilirubin and beta-hydroxybutyrate concentrations in the experimental groups were smaller than those in the control group. This suggests a smaller strain on the energy and liver metabolism in the experimental groups compared to the control group. The nonsignificant changes of the activity of GLDH and AST indicate no negative influence on the liver function after applicating Propranolol. The stronger reduction of rumen motility and the smaller increase of the FFA concentration in the group with 1 mg Propranolol/kg body weigth per day compared to the group with 0.5 mg Propranolol/kg body weigth per day shows the dose-dependent effect of Propranolol. The application of Propranolol at a dose of 0.5 mg or 1 mg/kg body weigth per day is a suitable method to early inhibit fasting-induced lipolysis in sheep.

In this study, the effect of a passive trapped-vortex cell on lift to drag (L/D) ratio of an FFA-W3-301 airfoil is studied. The upper surface of the airfoil was modified to incorporate a cavity defined by seven parameters. The L/D ratio of the airfoil is modeled using a radial basis function metamodel. This model is used to find the optimal design parameter values that give the highest L/D. The numerical results indicate that the L/D ratio is most sensitive to the position on an airfoil’s upper surface at which the cavity starts, the position of the end point of the cavity, and the vertical distance of the cavity end point relative to the airfoil surface. The L/D ratio can be improved by locating the cavity start point at the point of separation for a particular angle of attack. The optimal cavity shape (o19_aXX) is also tested for a NACA0024 airfoil.

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No description available.