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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.
651

One step at a time: analysis of neural responses during multi-state tasks

Grey, Talora Bryn 28 April 2020 (has links)
Substantial research has been done on the electroencephalogram (EEG) neural signals generated by feedback within a simple choice task, and there is much evidence for the existence of a reward prediction error signal generated in the anterior cingulate cortex of the brain when the outcome of this type of choice does not match expectations. However, less research has been done to date on the neural responses to intermediate outcomes in a multi-step choice task. Here, I investigated the neural signals generated by a complex, non-deterministic task that involved multiple choices before final win/loss feedback in order to see if the observed signals correspond to predictions made by reinforcement learning theory. In Experiment One, I conducted an EEG experiment to record neural signals while participants performed a computerized task designed to elicit the reward positivity, an event-related brain potential (ERP) component thought to be a biological reward prediction error signal. EEG results revealed a difference in amplitude of the reward positivity ERP component between experimental conditions comparing unexpected to expected feedback, as well as an interaction between valence and expectancy of the feedback. Additionally, results of an ERP analysis of the amplitude of the P300 component also showed an interaction between valence and expectancy. In Experiment Two, I used machine learning to classify epoched EEG data from Experiment One into experimental conditions to determine if individual states within the task could be differentiated based solely on the EEG data. My results showed that individual states could be differentiated with above-chance accuracy. I conclude by discussing how these results fit with the predictions made by reinforcement learning theory about the type of task investigated herein, and implications of those findings on our understanding of learning and decision-making in humans. / Graduate
652

Distinctive striatal dopamine signaling after dieting and gastric bypass

Hankir, Mohammed K., Ashrafian, Hutan, Hesse, Swen, Horstmann, Annette, Fenske, Wiebke K. January 2015 (has links)
Highly palatable and/or calorically dense foods, such as those rich in fat, engage the striatum to govern and set complex behaviors. Striatal dopamine signaling has been implicated in hedonic feeding and the development of obesity. Dieting and bariatric surgery have markedly different outcomes on weight loss, yet how these interventions affect central homeostatic and food reward processing remains poorly understood. Here, we propose that dieting and gastric bypass produce distinct changes in peripheral factors with known roles in regulating energy homeostasis, resulting in differential modulation of nigrostriatal and mesolimbic dopaminergic reward circuits. Enhancement of intestinal fat metabolism after gastric bypass may also modify striatal dopamine signaling contributing to its unique long-term effects on feeding behavior and body weight in obese individuals.
653

Distinctive striatal dopamine signaling after dieting and gastric bypass

Hankir, Mohammed K., Ashrafian, Hutan, Hesse, Swen, Horstmann, Annette, Fenske, Wiebke K. January 2015 (has links)
Highly palatable and/or calorically dense foods, such as those rich in fat, engage the striatum to govern and set complex behaviors. Striatal dopamine signaling has been implicated in hedonic feeding and the development of obesity. Dieting and bariatric surgery have markedly different outcomes on weight loss, yet how these interventions affect central homeostatic and food reward processing remains poorly understood. Here, we propose that dieting and gastric bypass produce distinct changes in peripheral factors with known roles in regulating energy homeostasis, resulting in differential modulation of nigrostriatal and mesolimbic dopaminergic reward circuits. Enhancement of intestinal fat metabolism after gastric bypass may also modify striatal dopamine signaling contributing to its unique long-term effects on feeding behavior and body weight in obese individuals.
654

Implicit and Explicit Appetitive Outcome-Learning in Obesity

Meemken, Marie-Theres 25 September 2020 (has links)
No description available.
655

Investigation into changes of the serotonin transporter (5-HTT) gene promoter in association with in vivo prefrontal 5-HTT availability and reward function in human obesity

Drabe, Mandy 24 September 2018 (has links)
A polymorphism in the promoter region of the human serotonin transporter (5-HTT)-coding SLC6A4 gene (5-HTTLPR) has been implicated in moderating susceptibility to stress-related psychopathology and to possess regulatory functions on human in vivo 5-HTT availability. However, data on a direct relation between 5-HTTLPR and in vivo 5-HTT availability have been inconsistent. Additional factors such as epigenetic modifications of 5-HTTLPR might contribute to this association. This is of particular interest in the context of obesity, as an association with 5-HTTLPR hypermethylation has previously been reported. Here, we tested the hypothesis that methylation rates of 14 cytosine-phosphate-guanine (CpG) 5-HTTLPR loci, in vivo central 5-HTT availability as measured with [11C]DASB positron emission tomography (PET) and body mass index (BMI) are related in a group of 30 obese (age: 36±10 years, BMI>35 kg/m2) and 14 normal-weight controls (age 36±7 years, BMI<25 kg/m2). No significant association between 5-HTTLPR methylation and BMI overall was found. However, site-specific elevations in 5-HTTLPR methylation rates were significantly associated with lower 5-HTT availability in regions of the prefrontal cortex (PFC) specifically within the obese group when analyzed in isolation. This association was independent of functional 5-HTTLPR allelic variation. In addition, negative correlative data showed that CpG10-associated 5-HTT availability determines levels of reward sensitivity in obesity. Together, our findings suggest that epigenetic mechanisms rather than 5-HTTLPR alone influence in vivo 5-HTT availability, predominantly in regions having a critical role in reward processing, and this might have an impact on the progression of the obese phenotype.:Introduction ............................................................................................................. 3 Homeostatic and hedonic control of food intake...................................................... 3 The obesity epidemic .............................................................................................. 4 The role of 5-HT in energy balance......................................................................... 5 The role of 5-HT in the PFC function....................................................................... 6 The role of the PFC in food intake .......................................................................... 7 The association between central 5-HT transporter (5-HTT) availability and obesity ..................................................................................................................................7 Genetics of obesity ................................................................................................. 8 Epigenetics of obesity ............................................................................................. 9 Objectives and hypothesis of the present work...................................................... 11 Manuscript ..... ....................................................................................................... 12 Summary ............................................................................................................... 20 References ............................................................................................................ 22 Appendices ............................................................................................................I Glossary ................................................................................................................ I Publications ........................................................................................................... IV Selbstständigkeitserklärung................................................................................... V Danksagung .......................................................................................................... VI
656

Klara, färdiga, generation Z : Akta så de inte springer ifrån er! / Ready, set, generation Z! : Watch out so that they don’t outrun you!

Broström, Madeleine, Larsson, Emelie January 2020 (has links)
Bakgrund: Ett effektivt styrverktyg många organisationer använder sig av är belöningssystem, i syfte att motivera och behålla sina medarbetare. En ny generation, Generation Z är på väg att inta arbetsmarknaden, vilket innebär nya karaktärsdrag, egenskaper och attityder mot arbetet och arbetsplatsen. Det är således viktigt att organisationer tar hänsyn till Generation Zs styrkor och motivationsfaktorer, för att kunna styra och motivera dem till att uppnå organisationens mål och behålla dem i organisationen. Med omotiverade och missnöjda medarbetare kan organisationen öka sin personalomsättning, och därmed förlora viktig kunskap och kompetens, vilket utgör en stor kostnad för organisationen. En av de branscher svenska Generation Z kommer arbeta inom är bankbranschen och är den bransch den här studien har fokuserat på. Syfte: Studiens syfte är att bidra med en djupare kunskap och förståelse om vad som driver och motiverar svenska Generation Z i arbetslivet. Organisationer inom bankbranschen kan utifrån informationen i den här studien, utforma och anpassa sina belöningssystem för att på bästa sätt motivera Generation Z. Genom att lyckas med det, kan organisationer behålla Generation Z i företaget och därmed minska sin kostnad för personalomsättning. Teoretisk referensram: Studiens teori inleds med generationsteorin av Mannheim (1970) och en definition av Generation Z. Vidare presenteras två motivationsteorier: behovshierarkin av Maslow (1987) och tvåfaktorsteorin av Hertzberg et al. (1959), vilka underlättar förståelsen kring vad som skapar motivation. Avslutningsvis behandlas teorier om belöningssystem, finansiella och icke-finansiella belöningar. Metod: Studien utgår ifrån en fallstudiedesign som grundar sig på en kvantitativ enkätundersökning med individer som ingår i Generation Z och som studerade någon form av ekonomi på högskolenivå. Enkätundersökningen kompletterades med fyra kvalitativa intervjuer med individer inom Generation Z, som arbetade inom bankbranschen. De två insamlingsmetoderna utgjorde tillsammans en triangulering. Slutsatser: De faktorer som är mest motiverande i ett belöningssystem för Generation Z är de icke-finansiella belöningarna: karriärmässig utveckling, kompetensutveckling och inflytande över arbetsuppgifter. Dessutom ansågs anställningstrygghet, uppmärksamhet från chefer och bra relation till kollegor som viktiga parametrar för att stanna på en arbetsplats. / Background: To motivate and retain employees, reward systems are used in many organizations as an effective management tool. A new generation, Generation Z is about to enter the labor market, which means new traits, characteristics and attitudes towards work and the workplace. It is therefore important that organizations take Generations Z’s strengths and motivational factors into account, in order to guide and motivate them to achieve the organization’s goals and keep them in the organization. With unmotivated and dissatisfied employees, organizations can lose important skills and increase their labor turnover, which is a huge expense for organizations. One industry that Swedish Generation Z will be working within is the banking industry, which is the industry this study will focus on. Purpose: The purpose of the study is to contribute with a deeper knowledge and understanding of what motivates Swedish Generation Z in working life. Organizations within the banking industry can, based on the information in this study, design and adapt their reward systems in the most efficient way to motivate Generation Z. By succeeding in this, organizations can keep Generation Z in the company and thereby reduce their labor turnover to the better. Theory: The theory of the study starts with the generation theory by Mannheim (1970) and a definition of Generation Z. Furthermore, two motivation theories, the hierarchy of needs by Maslow (1987) and the two-factor theory by Hertzberg et al. (1959) which facilitates the understanding of what creates motivation. Finally, theories of reward systems, financial and non-financial rewards are discussed. Method: This study is based on a case study performed as a quantitative survey with individuals within Generation Z, who studied some form of economics at the university level. The survey was supplemented by four qualitative interviews with individuals within Generation Z, who worked in the banking industry. The two collection methods together constituted a triangulation. Conclusions: The factors that are the most motivating in a Generation Z reward system are the non-financial rewards: career development, skills development, and influence over tasks. In addition, job security, attention from managers and a good relationship with colleagues were considered important parameters for staying in a workplace.
657

Må bra på heltid! : En studie om bemanningsanställdas upplevda välmående i den svenska ekonomisektorn.

Lazem, Rashad, Brindstedt, Patrik, Nordström, Mattias January 2022 (has links)
Forskningsfrågor: Vilka arbetsfaktorer anser personer anställda genom bemanningsföretag påverka deras välmående och varför? Hur skiljer välmående sig mellan deltid- och heltidsanställda inom bemanningsföretag i förhållande till identifierade arbetsfaktorer? Syfte: Syftet med denna studie är att undersöka det upplevda välmåendet hos personer som är anställda genom bemanningsföretag i ekonomisektorn samt vilka faktorer som har en påverkan på det upplevda välmåendet. En jämförelse kommer att göras mellan personer som arbetar heltid och de som arbetar deltid via ett bemanningsföretag. Metod: Studien är en kvalitativ studie. Data samlades in med hjälp av semistrukturerade intervjuer, som hölls med åtta respondenter. Intervjuerna hölls via Microsoft Teams. Hälften av respondenterna var heltidsanställda och andra hälften var deltidsanställda.  Slutsats: Många av de identifierade faktorerna är sammankopplade. Jobbsäkerhet, karriärutveckling, inkludering/exkludering och arbetsutveckling har alla en central del för välmåendet. Anledningen till detta är bland annat att jobbsäkerhet har stora konsekvenser även utanför jobbet och påverkar även andra faktorer som ekonomisk kompensation, förväntningar och möjligheter till karriärutveckling. / Research questions: What work factors do people employed within staffing companies deem affects their wellbeing and how?How does wellbeing differ between part- and full-time employees within staffing companies in relation to the work factors? Purpose: The purpose of this study is to examine the perceived well-being of people who are employed through staffing companies in the financial sector and which factors have an impact on the perceived well-being. A comparison will be made between people who work full time and those who work part time through a staffing company. Method: The study is a qualitative study. Data were collected using semi-structured interviews, which were conducted with eight respondents. The interviews were conducted via Microsoft Teams. Half of the respondents were full-time employees while the other half were part-time employees. Conclusion: Many of the identified factors are interconnected. Job security, career development, inclusion / exclusion and job development all have a central part to well-being. The reason for this is, among other things, that job security also has major consequences outside of work and also affects other factors such as financial compensation, expectations and opportunities for career development.
658

Psykiskt välbefinnande : En kvantitativ studie inom IT-förvaltning på en statlig myndighet / Psychological well-being : A quantitative study conducted within IT management at a government authority

Kerr, Jenny January 2021 (has links)
Denna studie syftade till att undersöka psykiskt välbefinnande bland statligt anställda män och kvinnor med eller utan ledarskapsansvar. En enkät innehållande frågor om bakgrundsvariabler; kön, ledarskapsansvar samt upplevd ansträngning och belöning skickades ut till 210 anställda. Frågorna om ansträngning och belöning utgick från den så kallade ansträngning- och belöningsmodellen. Femtiotre respondenter, 27 män (51%) och 26 kvinnor (49%), besvarade enkäten. Resultatet visade att 76% (n=40) av respondenterna upplevde enpositiv obalans mellan ansträngning och belöning medan 24% (n=13) upplevde en negativ obalans. Upplevd ansträngning uppvisade en signifikant korrelation med upplevd belöning, rs = -0.458, p&lt;0.05. Dock uppvisade varken kön eller anställningsposition en signifikant association med obalans mellan ansträngning och belöning. Kön: Chi2 (1, n=53) = 0.158, p&gt;0.05. Anställningsposition: Chi2 (1, n=53) = 0.2, p&gt;0.05. Det psykiska välbefinnandet kan påverkas negativt om en obalans mellan upplevelsen av ansträngning och belöning föreligger. På grund av låg sampelstorlek och begränsningar i statistisk styrka kan föreliggande studie inte dra några definitiva slutsatser om balansenmellan ansträngning och belöning samvarierar med kön och/eller anställningsposition i studiepopulationen. / The purpose of this study was to investigate psychological well-being amongst government employees consisting of men and women with or without staff responsibility. A survey, consisting of questions regarding background variables; gender, staff responsibility and experienced effort and reward, was distributed to 210 employees. The questions regarding effort and reward were based on the Effort and Reward Imbalance Model. Fifty-three respondents, 27 men (51%) and 26 women (49%), took part. Results showed that 76% (n=40) of the respondents experienced a positive imbalance between effort and reward while 24% (n=13) experienced a negative imbalance thereof. Experienced effort showed a significant correlation with experienced reward, rs = -0.458, p&lt;0.05. Neither gender nor employment category, however, showed a significant association with effort and reward imbalance. Gender: Chi2 (1, n=53) = 0.158, p&gt;0.05. Employment category: Chi2 (1, n=53) = 0.2, p&gt;0.05. The psychological well-being can be affected negatively if an imbalance between effort and reward occurs. This study cannot draw any firm conclusions of a potential associationbetween gender and employment category within the study population due to low sample size and limitations in statistical power.
659

Medarbetarskap inom dagligvaruhandel : Hur icke-finansiella belöningar kan inverka på medarbetarskapet / Empowerment/employeeship in the Grocery trade : Non-financial rewards and its impact on employeeship

Petrusson, Isabell, Obberson, Emma January 2021 (has links)
Idag finns det en stor konkurrens mellan butiker inom dagligvaruhandel, varav ledningen är i ett stort behov av sin arbetskraft. Medarbetarskap är ett begrepp som belyser medarbetarnas engagemang och ansvarstagande på arbetsplatsen. I dagsläget finns det en medvetenhet om att cheferna bör kunna påverka medarbetarskapet, däremot finns det inte några konkreta metoder eller verktyg för hur medarbetarskapet kan bli inverkat på. I samband med att det finns en vetskap om att icke-finansiella belöningar kan påverka anställdas beteende på arbetsplatsen, väcks intresset för om de här även kan ha en inverkan på medarbetarskapet. Studiens syfte är att redogöra kring förutsättningar som behövs för att uppnå ett gott medarbetarskap och att ta reda på ifall icke-finansiella belöningar kan inverka på medarbetarskapet. I den teoretiska referensramen beskrivs teorier om medarbetarskap och belöningar, däribland förklaras medarbetarskapshjulet och icke-finansiella belöningar. Datainsamlingen baseras på en kvalitativ metod, där sju butiksmedarbetare har intervjuats. Av studien framgick öppenhet och förtroende mellan medarbetarna vara faktorer som bidrog till ett gott medarbetarskap. Det framkom att ansvarsfördelning var en viktig aspekt för medarbetarna, både för skapandet av engagemang men också för att få medarbetarna att stanna kvar på arbetsplatsen. Därav kunde det konstateras att icke-finansiella belöningar i form av arbetsberikning och utveckling i form av varierade arbetsuppgifter kunde vara avgörande för medarbetarskapet. Olika former av erkännande och positiv återkoppling kunde användas för att skapa öppenhet och engagemang hos medarbetarna. Sociala aktiviteter kunde användas för att belöna medarbetarna och kunde konstateras inverka på medarbetarskapet i form av gemenskap. På grund av studiens begränsningar kan inga säkra slutsatser dras. Förslag till fortsatt forskning är exempelvis att studera medarbetarskapet utifrån butikernas storlek, studera medarbetarskapet utifrån chefernas perspektiv och studera medarbetarskapet i förhållande till lönsamheten. / Today, there is a great deal of competition between stores in the grocery trade, of which the management is in great need of its labor. Empowerment/employeeship is a concept that highlights employees' commitment and responsibility in the workplace. At present, there is an awareness that managers should be able to influence employeeship, however, there are no concrete methods or tools for how employeeships can be affected. In connection with the knowledge that non-financial rewards can affect employees' behavior in the workplace, it arouses interest in whether they can have an impact on employeeship. The purpose of the study is to report on the conditions needed to achieve good employeeship and to find out if non-financial rewards can affect employeeship. The theoretical frame of reference describes theories about employeeship and rewards, including explaining the ‘’employeeship wheel’’ and non-financial rewards. Data collection is based on a qualitative method, where seven store employees have been interviewed. The study showed that openness and trust between employees were factors that contributed to good employeeship. It emerged that responsibility was an important aspect for the employees, both for the creation of commitment but also for getting the employees to stay in the workplace. From this, it could be stated that non-financial rewards in the form of work enrichment and development in the form of varied tasks could be decisive for the employees. Various forms of recognition and positive feedback could be used to create openness and commitment among employees. Social activities could be used to reward employees and could be found to affect employeeship in the form of community. Due to the limitations of the study, no definite conclusions can be drawn. Suggestions for further research are, for example, to study the employeeship based on the size of the stores, study the employeeship from the managers' perspective and study the employeeship in relation to profitability.
660

FÖRÄNDRING, PÅ GOTT OCH ONT : En fallstudie av omstruktureringen av ett belöningssystem i en decentraliserad bank

Effort, Evelina, Näsberg Hallqvist, Hanna January 2021 (has links)
Banksektorn har under de senaste decennierna blivit allt mer kunskapsintensiv och en förståelse för det skifte som sker för framtidens medarbetare blir allt mer essentiell. Strategiska förändringar medför krav på ledningen att tillvarata sina medarbetares intressen genom att bland annat skapa incitament för att bibehålla gamla och skapa nya konkurrensfördelar. Syftet med vår studie är att beskriva en pågående förändringsprocess för att skapa en förståelse för hur ett generationsskifte influerar en decentraliserad organisations omstrukturering av belöningssystem. Genom detta avser vi fylla ett kunskapsgap avseende hur organisationer hanterar processen kring och utformningen av belöningssystem.  Studiens metod har utgått från en kvalitativ fallstudie. Genom 6 intervjuer på ett utvalt fallföretag har empiri insamlats för att skapa en förståelse för hur en decentraliserad organisation hanterar ett förändringsarbete i praktiken samt hur det påverkar hur ett belöningssystem moderniseras. Respondenterna är noga utvalda bland anställda från både ledande befattningar och inom kontorsrörelsen för att möjliggöra en bred förståelse för organisationsstrukturen samt dess respektive insyn i det fortskridande arbetet. Utifrån resultatet av studien kan slutsatsen dras att fallföretagets förändringsarbete har präglats av en stark top-downstyrning. En bristande medarbetarinvolvering har påvisat brister i processen och paradoxer gentemot organisationens starkt decentraliserade kultur. Vidare visar studien på att belöningssystem vid bemötande av generationsskifte är ett effektivt instrument. Emellertid kan den önskade effekten av omstruktureringen bli kortvarig om organisationen inte vidtar ytterligare åtgärder. En komplettering av instrumentet kan hjälpa företaget att uppnå en attraktivare arbetsmiljö, för alla. / The banking sector has become increasingly knowledge-intensive in recent decades, and an understanding of the shift that is taking place for future employees is becoming increasingly essential. Strategic changes entail demands on management to safeguard the interests of its employees by, among other things, creating incentives to maintain old ones and create new competitive advantages. The purpose of this study is to explain an ongoing change process to create a deep understanding of how social progress affects a decentralized organization's modernization and restructuring of incentive programs. Through this, we intend to fill the current knowledge gap regarding how organizations should handle the change process and design of reward systems. The study has been based on a qualitative case study. Through 6 interviews at a selected case company, empirical data has been collected to create an understanding for how a decentralized organization handles change management in practice and how this affects the outcome of a restructured reward system. The respondents are carefully selected among employees from both management positions and within the business field to enable a broad understanding of the organization. The study has resulted in the conclusion that the company's change management has been characterized by strong top-down control. A lack of employee involvement has shown shortcomings in the change process and paradoxes towards the organization's highly decentralized culture. Furthermore, the study shows that reward systems as a tool in dealing with generational change are an effective instrument. However, the desired effect of the restructuring may be short-lived if the organization does not take further action. Complementing the instrument can help the company attain a more attractive work environment, for everyone.

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