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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1041

Peripheral Dopamine 2 Receptors Both Modulate Central Dopamine Release and Adopt in a Similar Manner to that of Central Dopamine 2 Receptors

Obray, J. Daniel 24 April 2020 (has links)
Alcohol use disorder is a debilitating disorder affecting nearly 5% of people in the United States. Despite the prevalence of alcohol use disorder few affected individuals seek treatment and of those who do many will relapse. This highlights a need to develop new treatments for alcohol use disorder that are both more accessible and more effective. This dissertation characterizes a novel pathway involved in ethanol enhancement of dopamine levels in the nucleus accumbens as well as investigating alterations in dopamine 2 receptor expression and function following an acute dose of ethanol. This was done by using microdialysis to measure dopamine levels in the nucleus accumbens, single-unit recordings of dopamine neurons in the ventral tegmental area to measure dopamine neuron activity and place conditioning to measure the rewarding properties of the intravenous dopamine and ethanol. It was found that activation of peripheral dopamine 2 receptors by intravenous dopamine enhanced dopamine levels in the nucleus accumbens and dopamine neuron firing rate in the ventral tegmental area. Additionally, intravenous dopamine produced a modest conditioned place preference. Domperidone, a peripheral dopamine 2 receptor antagonist blocked each of these effects. Further, domperidone blocked ethanol enhancement of dopamine release in the nucleus accumbens and bidirectionally modulated the sedating effects of ethanol depending on the dose of ethanol administered. The involvement of peripheral dopamine 2 receptors in ethanol reward could not be ascertained in these studies as domperidone produced a weak conditioned place aversion. Finally, acute ethanol was found to enhance dopamine 2 receptor expression in the nucleus accumbens and medial prefrontal cortex while also enhancing dopamine 2 receptor expression on NK and B cells. Additionally, ethanol was found to reduce desensitization of dopamine 2 receptors in the ventral tegmental area. These results demonstrate that activation of peripheral dopamine 2 receptors can enhance dopamine levels in the nucleus accumbens and that this effect has relevance in understanding the effects of ethanol on dopamine release in the mesolimbic pathway. These results also provide evidence for transient upregulation of dopamine 2 receptors in the brain and on leukocytes suggesting that dopamine 2 receptor levels on leukocytes may be a useful biomarker for central dopamine function.
1042

Public Perception of Alternative Intersection Designs

Sarah E Adsit (10716579) 29 April 2021 (has links)
Improving intersection safety and efficiency are the primary goals of alternative intersection designs. These designs seek to improve on traditional traffic control methods, often by reducing intersection conflict points, reducing or eliminating time-wasting signal phases, or both. However, public opposition to these new designs can be a large barrier to implementation of alternative intersections despite their known safety and efficiency benefits.<br><br>This study evaluated current public perception and factors influencing that perception for four alternative intersection designs - the roundabout, the restricted crossing U-turn (also known as J-turn and reduced conflict intersection), the displaced left turn (also known as the continuous flow intersection), and the diverging diamond interchange (also known as the double crossover diamond interchange). <br><br>To achieve this objective, a survey instrument was designed and distributed to a target sample of 1,000 adults residing in the State of Indiana. The survey solicited participant awareness of these designs, acceptance of a potential implementation of the design in their community, and driver confidence using the design along with participant socio-demographic data. Descriptive and inferential statistical analysis was then conducted. <br><br>The survey results indicate that residents of Indiana are not aware of designs not currently widely implemented in the state, that opposition to these rarer designs is prominent, and that drivers were generally less confident in their ability to safely navigate these unfamiliar designs. Younger respondents, male respondents, more highly educated respondents, respondents who travel more often or for farther distances, and respondents who rate their own driving ability highly are more likely to be aware, accepting, and confident using alternative designs. <br><br>The results of this study will inform future outreach efforts pertaining to alternative intersections by improving transportation agency understanding of public opinions and primary concerns regarding these designs and provide potential paths for improving public perception. <br>
1043

Does Corporate Liquidity Affect Dividend Policy? : A Quantitative Study on Public European Firms

Johansson, Jakob, Martin, Hallberg January 2021 (has links)
This thesis examines the relationship between corporate liquidity and dividend policy. The corporate liquidity is measured by proven liquidity ratios and the dividend policy is divided into cash dividends and share repurchases. In order to examine the possible relationship between corporate liquidity and dividend policy, public European firms are examined. Denmark, France, Germany, Norway, Sweden, and the UK are selected based on the similarities in the regulation and market structure in the countries. The thesis aims at furthering the knowledge on the role played by corporate liquidity for dividend policy. In our ambition to investigate the before-mentioned relationship we use a panel data set over five years extracted from Datastream. Any newfound evidence on the subject can help investors, creditors, and other stakeholders in evaluating firms based on their liquidity.  We used a deductive quantitative method to analyse the chosen relationship. The study concluded a significant relationship between corporate liquidity and dividend, although negative as opposed to our expectations. With regards to share repurchase, no significant effect was found from corporate liquidity. Free cash flow on the other hand appears to have a positive effect on the amount of share repurchases carried through. We discuss mentioned relationships and attribute them to the mature firms in this sample and the liquidity levels of mature firms.The theories supporting these findings are Agency Theory, Pecking Order Theory, Shareholder Theory, Stakeholder Theory, Liquidity Preference Theory.
1044

Faktory ovlivňující hodnocení atraktivity mužské postavy / Factors affecting perception of human male body

Třebický, Vít January 2012 (has links)
According to previous research physical attractiveness plays an important role in our everyday life. People are treated differently on the basis of their physical appearance and from an evolutionary point of view physical attractiveness is a key factor in mate selection, being a cue of an individual's mate value and genetic qualities. Research shows that the highest attractiveness ratings tend to be given to physiques with a higher level of development of lean muscle mass and a V shaped upper body. Such a physique body constitution could indicates how a high level of physical fitness and a man's health of man and be a cue of the man's qualities as a mating partner. However, results of the previous studies are inconclusive due to the methods and stimuli employed. To address the shortcomings exhibited by the previous studies investigations, we ran two online studies. In the first study, women rated the attractiveness of a new and more extensive set of black and gray silhouettes derived from photos of the somatotypes. In the second study, we tested whether physical attractiveness of men can be increased by a voluntary change of their upper body shape. In both studies we were testing how interindividual differences of the female raters modulate the ratings of attractiveness. Results of the first study...
1045

Celková imigrační reforma zastavena Poučení z vývoje v americkém Senátu 2004-2010 / Comprehensive immigration reform suspended: Lessons from the U.S. Senate 2004-2010

Švajda, Michal January 2011 (has links)
The M.A. thesis "Comprehensive Immigration Reform Postponed: Lessons from the Senate 2004- 2010" elaborates upon the causes hindering in the years 2004 to 2010 the adoption of a comprehensive immigration reform in the United States of America. The main goal of the thesis is to assess the consequences of the polarization of the American political scene on the immigration reform and to evaluate the party divide on the matter upon the floor remarks made by the members of Senate Committee on the Judiciary taking in account the differences in between the 109th and 111th Senate. The focus on the Committee on the Judiciary is justified by the role played by its members in the drafting process of particular reform proposals. The scope of the polarization of the Committee is assessed upon the aggravated means attributed to the most dominant narratives used by the senators. The remarks used in the evaluation are addressed in the context of the most significant contemporary factors influencing the polarization of American political scene as well as under the light of the development surpassing the domestic affairs.
1046

Možné změny v partnerských preferencích transsexuálů female-to-male v průběhu procesu přeměny pohlaví / Possible changes in partner preferences of female-to-male transsexuals during the sex change process

Málková, Markéta January 2014 (has links)
The main topic of this thesis is investigation of partner preferences and sexual behavior of female-to-male transsexuals. Number of previous studies showed that on average several partner preferences differ between men and women, and our goal was to determine if these preferences vary in female-to-male transsexuals during the process of sex change. The process of sex change includes intensive exposures to external levels of sex hormones, psychological therapy, and the transformation of their social role and overall life changes. Based on reviewe of the the scientific literature dealing with transsexuality, partner preferences and the potential impact of hormone therapy on sexually dimorphic traits, we developed a questionnaire focusing on partner preference and behavior. We obtained data from 36 heterosexual men transsexual female -to -male (i.e., sexual orientation focused on women) who were divided into three groups according to whether they were prior hormonal therapy (N = 11), whether have already started hormone therapy sex but not yet surgical change ( N = 11) and whether they were already after hormonal and surgical gender conversion (N = 14). In addition, we obtained data from 16 heterosexual non-transsexual men as a control group. Based on my previous bachelor research and literature...
1047

The Effects of Body Position and Degree of Handedness on Cognitive Flexibility

Mason, Alyssa Marie January 2021 (has links)
No description available.
1048

Style Preference Survey: A Report on the Psychometric Properties and a Cross-Validation Experiment

Smith, Sherri L., Todd, Ricketts, McArdle, Rachel A., Chisolm, Theresa H., Alexander, Genevieve, Bratt, Gene 01 February 2013 (has links)
Background: Several self-report measures exist that target different aspects of outcomes for hearing aid use. Currently, no comprehensive questionnaire specifically assesses factors that may be important for differentiating outcomes pertaining to hearing aid style. Purpose: The goal of this work was to develop the Style Preference Survey (SPS), a questionnaire aimed at outcomes associated with hearing aid style differences. Two experiments were conducted. After initial item development, Experiment 1 was conducted to refine the items and to determine its psychometric properties. Experiment 2 was designed to cross-validate the findings from the initial experiment. Research Design: An observational design was used in both experiments. Study Sample: Participants who wore traditional, custom-fitted (TC) or open-canal (OC) style hearing aids from 3 mo to 3 yr completed the initial experiment. One-hundred and eighty-four binaural hearing aid users (120 of whom wore TC hearing aids and 64 of whom wore OC hearing aids) participated. A new sample of TC and OC users (n 5 185) participated in the cross-validation experiment. Data Collection and Analysis: Currently available self-report measures were reviewed to identify items that might differentiate between hearing aid styles, particularly preference for OC versus TC hearing aid styles. A total of 15 items were selected and modified from available self-report measures. An additional 55 items were developed through consensus of six audiologists for the initial version of the SPS. In the first experiment, the initial SPS version was mailed to 550 veterans who met the inclusion criteria. A total of 184 completed the SPS. Approximately three weeks later, a subset of participants (n 5 83) completed the SPS a second time. Basic analyses were conducted to evaluate the psychometric properties of the SPS including subscale structure, internal consistency, test-retest reliability, and responsiveness. Based on the results of Experiment 1, the SPS was revised. A cross-validation experiment was then conducted using the revised version of the SPS to confirm the subscale structure, internal consistency, and responsiveness of the questionnaire in a new sample of participants Results: The final factor analysis led to the ultimate version of the SPS, which had a total of 35 items encompassing five subscales: (1) Feedback, (2) Occlusion/Own Voice Effects, (3) Localization, (4) Fit, Comfort, and Cosmetics, and (5) Ease of Use. The internal consistency of the total SPS (Cronbach'sa5 .92) and of the subscales (each Cronbach'sa..75) was high. Intraclass correlations (ICCs) showed that the test-retest reliability of the total SPS (ICC5.93) and of the subscales (each ICC..80) also was high. TC hearing aid users had significantly poorer outcomes than OC hearing aid users on 4 of the 5 subscales, suggesting that the SPS largely is responsive to factors related to style-specific differences. Conclusions: The results suggest that the SPS has good psychometric properties and is a valid and reliable measure of outcomes related to style-specific, hearing aid preference.
1049

Style Preference Survey: A Report on the Psychometric Properties and a Cross-Validation Experiment

Smith, Sherri L., Todd, Ricketts, McArdle, Rachel A., Chisolm, Theresa H., Alexander, Genevieve, Bratt, Gene 01 February 2013 (has links)
Background: Several self-report measures exist that target different aspects of outcomes for hearing aid use. Currently, no comprehensive questionnaire specifically assesses factors that may be important for differentiating outcomes pertaining to hearing aid style. Purpose: The goal of this work was to develop the Style Preference Survey (SPS), a questionnaire aimed at outcomes associated with hearing aid style differences. Two experiments were conducted. After initial item development, Experiment 1 was conducted to refine the items and to determine its psychometric properties. Experiment 2 was designed to cross-validate the findings from the initial experiment. Research Design: An observational design was used in both experiments. Study Sample: Participants who wore traditional, custom-fitted (TC) or open-canal (OC) style hearing aids from 3 mo to 3 yr completed the initial experiment. One-hundred and eighty-four binaural hearing aid users (120 of whom wore TC hearing aids and 64 of whom wore OC hearing aids) participated. A new sample of TC and OC users (n 5 185) participated in the cross-validation experiment. Data Collection and Analysis: Currently available self-report measures were reviewed to identify items that might differentiate between hearing aid styles, particularly preference for OC versus TC hearing aid styles. A total of 15 items were selected and modified from available self-report measures. An additional 55 items were developed through consensus of six audiologists for the initial version of the SPS. In the first experiment, the initial SPS version was mailed to 550 veterans who met the inclusion criteria. A total of 184 completed the SPS. Approximately three weeks later, a subset of participants (n 5 83) completed the SPS a second time. Basic analyses were conducted to evaluate the psychometric properties of the SPS including subscale structure, internal consistency, test-retest reliability, and responsiveness. Based on the results of Experiment 1, the SPS was revised. A cross-validation experiment was then conducted using the revised version of the SPS to confirm the subscale structure, internal consistency, and responsiveness of the questionnaire in a new sample of participants Results: The final factor analysis led to the ultimate version of the SPS, which had a total of 35 items encompassing five subscales: (1) Feedback, (2) Occlusion/Own Voice Effects, (3) Localization, (4) Fit, Comfort, and Cosmetics, and (5) Ease of Use. The internal consistency of the total SPS (Cronbach'sa5 .92) and of the subscales (each Cronbach'sa..75) was high. Intraclass correlations (ICCs) showed that the test-retest reliability of the total SPS (ICC5.93) and of the subscales (each ICC..80) also was high. TC hearing aid users had significantly poorer outcomes than OC hearing aid users on 4 of the 5 subscales, suggesting that the SPS largely is responsive to factors related to style-specific differences. Conclusions: The results suggest that the SPS has good psychometric properties and is a valid and reliable measure of outcomes related to style-specific, hearing aid preference.
1050

Dispersal and habitat use of juvenile brown trout (Salmo trutta) following egg stocking : -A case study in the river Rotälven, Sweden / Spridning och habitatval av juvenil öring med ursprung från romutsättningar : -En fallstudie i Rotälven

Larsson, Jonathan January 2022 (has links)
Egg stocking in rivers and streams is a common measure to support and re-introduce salmonid populations. To ensure the success of egg stocking programs, knowledge of the early life stages of juveniles including dispersal ability and habitat preferences of fry is a prerequisite. This study was conducted to investigate downstream dispersal patterns and habitat use of young of the year brown trout in a mid-sized, channelized, boreal river in Sweden. Eyed trout eggs were stocked in February of 2021. During August of the same year, 2-3 months after emergence, trout were sampled by electrofishing within 1 km downstream of the stocking sites and each individual point of capture was recorded by GPS. In addition, data on riverbank slope, shoreline irregularity, stream bed substrate, water velocity and water depth were collected for each of the sampling sections. The results showed that trout fry were distributed throughout the 1 km long sampled sections and that the density of fry did not increase towards the stocking points. The observed variation in the distribution of trout fry was best explained by the riverbank slope. Approximately twice as high fry densities were found in reaches with gentle compared to medium and steep bank slopes. The differences are suggested to be an effect of 1) stream marginal water velocity differences during high flows affecting fry occupancy, and 2) that gentle slopes were often accompanied by shallow water, preferred by fry. These findings may provide helpful knowledge for fisheries managers to optimize the outcome of egg stocking and river restoration activities regarding fry recruitment. / Romutsättning i vattendrag är en vanlig åtgärd för att stärka och återetablera populationer av laxartade fiskar. För att lyckas med romutsättningar krävs kunskap om ynglens spridningsförmåga och habitatpreferenser. Denna studie genomfördes för att undersöka spridningsmönster och habitatval av ensomrig öring i en medelstor kanaliserad älv i Sverige. Ögonpunktad rom sattes ut i februari 2021. Under augusti samma år, 2-3 månader efter att ynglen lämnat lekgruset elfiskades 1 km långa sträckor direkt nedströms utsättningsplatserna. De fångade individernas position registrerades med GPS. Data över strandkantens lutning, strandzonens flikighet, bottensubstrat, vattenhastighet och djup samlades in för varje elfiskesträcka. Resultatet visade att öringyngel spridit sig över hela de 1 km långa elfiskesträckorna, och att tätheterna av yngel inte ökade med minskat avstånd till utsättningspunkterna. Den observerade variationen i fördelningen av öringyngel förklarades bäst av strandkantens lutning. Ungefär dubbelt så hög täthet av yngel förekom i sträckor med flack jämfört med medel och brant lutning. Skillnaderna föreslås vara en effekt av 1) skillnader i vattenhastighet under höga vattenflöden som påverkar ynglens möjligheter till att bibehålla sin position i habitatet, och 2) att flack lutning av strandkanten ofta åtföljdes av grunt vatten vilket föredras av yngel. Dessa upptäckter kan bidra med värdefull kunskap för att optimera romutsättningar och restaureringar i avseende på rekrytering av årsyngel.

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