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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.
31

OPTIMAL GROUP SIZE IN HUMANS: AN EXPERIMENTAL TEST OF THE SIMPLE PER CAPITA MAXIMIZATION MODEL

Klotz, Jared Lee 01 December 2016 (has links)
The current study utilized two experiments to assess Smith's (1981) simple per capita-maximization model, which provides a quantitative framework for predicting optimal group sizes in social foraging contexts. Participants engaged in a social foraging task where they chose to forage for points exchangeable for lottery prizes either alone or in a group that has agreed to pool and share all resources equally. In Experiment 1, groups (“settlements”) of 10 or 12 participants made repeated group membership choices. Settlements were exposed to three conditions in which the optimal group size was either 2, 5, or 2 for the 10 person settlement or 3, 4, or 6 for the 12 person settlement. A linear regression of the data from Experiment 1 revealed a strong relationship between the observed group sizes and group sizes predicted by the simple per capita maximization model. Experiment 2 was a systematic replication of Experiment 1 in which single participants foraged for shared resources with groups of automated players in a computerized simulation. Automated player group choices mirrored group choices of participants in Experiment 1; excluding the data for the best performing participant. Thus, the participant acted essentially in the stead of the best performing participant for each condition. Two logistic regressions provided mixed support for the model, while failing to replicate the results of Experiment 1, providing mixed support for the use of the simple per capita maximization model in predicting group sizes in social foraging contexts.
32

Förskollärarnas upplevelser av att arbeta med stora barngrupper : Pilotstudie / Preschool teachers’ experiences of working with large groups of children

Miller, Sandra, Swén, Rebecca January 2020 (has links)
Alla barn som går på förskola har rätt att delta på lika villkor och ha samma rättigheter enligt Barnkonventionen och i alla åtgärder som görs ska barns bästa komma i första hand. Under de senaste 30 åren har barngrupperna blivit större och utbildade personal saknas för att möta behovet. Syftet med denna pilotstudie är att analysera och diskutera förskollärarnas upplevelser av att arbeta med stora barngrupper. För att ge stöd åt vår undersökning valde vi att samla in material i form av en enkät. Data samlades in som sedan analyserades och delade upp utifrån två olika teman. Resultatet visar att förskollärarna upplever svårigheter att se varje enskilt barn på grund av gruppernas storlek och där det kollegiala lärandet blir huvudfokus. Förskollärarna upplever vidare att det saknas tid och fler utbildade förskollärare för att kunna genomföra arbetet utifrån läroplanens intentioner. Strategierna som förskollärarna använder sig av för att kunna hantera den stora gruppen är att dela den så långt som möjligt samt anpassa den pedagogiska miljön. I resultatet upplever förskollärare att det krävs förutsättningar för att kunna arbeta med stora grupper genom att det finns tillräckligt med personal. Slutsatsen är att förskollärarna upplever att de behöver förutsättningar för att möta den stora barngruppen.
33

Health consequences of group living in wild Verreaux’s sifakas (Propithecus verreauxi)

Rudolph, Katja 07 February 2020 (has links)
No description available.
34

A Survey of Ranging Patterns and Micro-Habitat Preference of Saguinus midas in Berg en Dal, Suriname

Cherundolo, Gina Marie 15 August 2018 (has links)
No description available.
35

Stress i förskolan - ökade krav, ökade sjukskrivningar : En textanalys av C-uppsaster om stress i förskolan / Stress in kindergarten - higer demands, more sickleave

Borg, Mattias January 2022 (has links)
The purpose with this qualitative text analysis is to study entire written C-essays in Sweden,about stress published between 2017 and 2022. The essay is gathered from DIVA using thekeywords “stress + förskola” and “förskollärare + stress” and includes 26 essays.The result indicates that stress preschool staff experience is connected to, the high workload, thegroup size of children, the high demands on pedagogical documentation, staff loss, high noiselevel, untrained substitutes, lack of substitutes and poor organization. In order to reduce stress,the documents show that fewer children in the children's groups are required or increased staffdensity and an organization that is responsive and strives towards a common goal.The study indicates a connection between stress and increased demands on preschool teachers inthe revised curriculum in 2016 and onwards. The increased number of long-term sick leave dueto stress in recent years among preschool teachers, might be a consequence. / Syftet med denna kvalitativa textanalys är att studera samtliga examensarbete och C-uppsatser iSverige som behandlar stress i förskolan 2017-2022. Dokumenten är hämtade från DIVA medsökorden “stress+förskola” och “förskollärare+stress” och omfattar 26 uppsatser.Resultatet indikerar att förskolepersonalen är stressad över: höga krav, för många arbetsuppgifter,som pedagogisk dokumentation, personalbortfall, barngruppens storlek och längre vistelsetider,hög ljudnivå, outbildade vikarier, brist på vikarier och dålig organisation. För att minska stressenkrävs enligt de granskade dokumenten, ökad personaltäthet över hela dagen, en organisation somär lyhörd och strävar mot samma mål.Studien indikerar ett samband mellan de höjda kraven på förskollärarna i de revideradeläroplanerna från 2016 och framåt och den ökade stressen. Detta skulle kunna knytas till attantalet långtidssjukskrivningar under samma period har ökat inom denna yrkesgrupp.Nyckelord: stress, förskola, förskollärare, barngruppsstorlek, personaltäthet, läroplanskrav
36

Essays on Contest Theory Experiments and Revealed Time Preference Models

Zou, Yanyang 22 August 2022 (has links)
In this series of essays, we study the influence of weight and group size in the sequential multi-battle contest with laboratory experiences (Chapter 2 and Chapter 3). We then develop an empirical method to model perceptual present and time inconsistency (Chapter 4). Chapter 2 examines how the weight and the ordered weights in battles affect the behavior in sequential multi-battle contests with an experiment. We find robustly that the weight of the current battle consistently influences contestants' efforts. Additionally, we discover the math-point-oriented behavior despite differences in history. In other words, the weight effect is expressed in two ways: influencing the effort of the current battle and transferring a contest to the next battle with a designated intensity. Chapter 3 explores the group size effect and how the contest success functions influence the group size effect in sequential multi-battle contests with an experiment. We capture the negative group size effect on the leaders' efforts, participation and dropout rates; contrarily, the positive effect on the non-leaders' efforts. Compared to the Tullock lottery, the all-pay auction intensifies the group size effect of the high effort in the initial battle. It also enlarges the observed group size effects of the effort gaps between the leaders and the non-leaders. Chapter 4 develops the quasi-hyperbolic discounting model into the general beta-delta model to parametrically detect and measure the inconsistency in revealed time preference. This method empirically classifies time preference into four categories, i.e., time consistent, present bias, future bias, and mixed inconsistent. Then we applied this method to the convex time budget data of seven experiments, including 3670 subjects. We discover empirical evidence supporting perceptual differences in the present-future threshold. Traditional present bias models may interpret the time preference imprecisely. / Doctor of Philosophy / Competition and Time are two essential aspects of life. Many decisions are made in a competitive environment. Some other decisions are made when time serves as a critical factor. We divide this dissertation into two parts. In the first part, we study strategic behavior in competitions. Specifically, we examine how (1) the importance of each round (weight), (2) the number of competitors, and (3) the ambiguity of the rule affect the result of a multi-round competition. In the second part, we study people's subjective understanding of time, generally the personal beliefs and preferences of the present and future. In part one (Chapter 2 and Chapter 3), first, we find people are very responsive about the importance of a round in a multi-round competition. When a round is more important, people make more effort in such round. People are also sensible about the competition's current status (leading, behind, or tied) rather than the history. Second, at the beginning of a competition, we find an increase in the participation rate when fewer competitors exist. Suppose there are more competitors; the leading position players compete more brutally; on the contrary, the non-leading players are discouraged more. Third, people spend more energy when the rule is less ambiguous in a multi-round competition. In part two (Chapter 4), We find a very diversified subjective belief in the word "present." The concept of "now" lasts longer than we conventionally thought. When the subjective "present'' is captured at the individual level, we find the immediate now is not necessarily the best way to represent the "average present'' for the population.
37

The causes and consequences of individual differences in cognitive performances in relation to the social environment in pheasants

Langley, Ellis Jessica Grace January 2018 (has links)
Identifying the causes and consequences of intra-specific variation in cognitive abilities is fundamental to our understanding of the evolution of cognition. The social environment and cognitive abilities appear inextricably linked, yet evidence for how the social environment affects cognitive performances and further, how cognitive performances influence the social environment, has seldom been explored. Using the pheasant, Phasianus colchicus, I explore the relationships between individual variation in cognitive performances in relation to broad and fine-scale structure of the social environment and endeavour to separate cause and consequence. I demonstrate a positive causal effect of the broad-scale social environment on cognitive performances by observing increases in the accuracy of spatial discrimination performances when individuals are in larger groups (Chapter Two and Chapter Four). I show that the positive effects of larger group size occur over a relatively short period (less than one week), suggesting that cognitive performances are flexible in response to the social environment and I suggest four potential mechanisms. I show that while males are part of a social hierarchy, spatial discrimination performances are related to this fine-scale social structure and higher-ranking males outperform lower ranking males (Chapter Three). When attempting to determine cause and consequence, I found that spatial learning performances early in life did not predict adult cognitive performances on the same task or predict their adult social rank (Chapter Four). Hence, my results do not support that social rank is a consequence of spatial learning abilities in male pheasants. The relationship between spatial learning performances and social rank was found in adult males that had their social rank artificially elevated, suggesting that cognitive performances were not simply the result of the current social environment but remain closely related to past agonistic relationships. I did not find a relationship between early life aggression with performances on either a spatial or a non-spatial task in females or males (Chapter Five). This highlights the importance of investigating early life relationships and suggests that the relationship between spatial learning and aggression in adult males may become associated over time as a consequence of further spatial learning experiences, and, or, aggressive interactions. I then demonstrate a consequence of individual variation in cognitive abilities and show that adult foraging associations in the wild disassort by early life cognitive performances (Chapter Six). Individuals with good inhibitory control performance and poor visual discrimination performances were more central in social networks. I propose that differences in cognitive abilities manifest in foraging strategy and influence the resulting social structure. The implications of this predictable social structure remain to be explored. Finally, I discuss these results and how they contribute to our understanding of how the social environment causes individual differences in cognitive performances, as well as how variation in cognitive performances may shape the social environment. I suggest the potential implications of these findings and ideas for future work.
38

Fissão-fusão em Cebus nigritus : flexibilidade social como estratégia de ocupação de ambientes limitantes / Fission-fusion in cebus nigritus : social flexibility as occupation strategy in limitants environments

Nakai, Érica Silva 17 August 2007 (has links)
A ordem primata apresenta uma grande diversidade de modos de organização social, desde espécies consideradas solitárias até aquelas em que os indivíduos de um grupo permanecem o tempo todo juntos. Macacos-prego (Cebus spp.) geralmente vivem em grupos estáveis e coesos, sem a formação de subgrupos. No entanto, sua organização social pode ser mais flexível. Dois estudos anteriores, conduzidos com populações de Cebus nigritus da Mata Atlântica, indicaram a divisão de grupos em subgrupos, mas não concluíram se os processos que foram observados eram de divisão permanente de um grupo grande ou se essas populações assumiam a organização social do tipo de fissão-fusão. O objetivo deste estudo foi investigar se os grupos de macacos-prego do Parque Estadual Carlos Botelho (PECB) caracterizam-se como sociedades do tipo fissão-fusão ou se a formação de subgrupos ocorre apenas como um estágio temporário pré-divisão permanente. No período de Janeiro de 2003 a Março de 2006, foram acompanhados dois grupos sociais, com os indivíduos adultos reconhecidos. Dados de outros grupos foram coletados de forma oportunística. Para verificar se o grupo estava forrageando de forma coesa ou dividido em subgrupos, era feito um censo dos membros do grupo a cada hora e, para o registro da composição dos subgrupos foi contado o número de machos adultos, de fêmeas adultas e de juvenis. Para avaliar a disponibilidade de alimento foram distribuídas 153 armadilhas \"pitfall\" ao longo da área de uso dos animais. Os dados sobre comportamento (locomoção, descanso, forrageamento e locomoção mais forrageamento) e dieta (frutos, invertebrados e folhas) foram registrados por amostragem de varredura, a cada 5 minutos. Também foram anotados o tempo de depleção das fontes de frutos (FTFS) e o número de indivíduos que se alimentaram juntos na mesma árvore (tamanho da subunidade de alimentação). Todos os grupos de macacos-prego observados no PECB organizaram-se em sociedades de fissão-fusão, dividindo-se constantemente em subgrupos de tamanho e composição variável, com associações preferenciais entre pares de macho e fêmea, composição multi-macho/multi-fêmea e ausência de dominância entre as fêmeas. Todas essas características observadas se assemelham com as características de chimpanzés e de primatas neotropicais que se organizam em fissão-fusão. A principal diferença entre os macacos-prego e essas espécies é a dispersão sexual do grupo natal. Em macacos-prego os machos migram entre grupos, enquanto em sociedades de fissão-fusão os machos são filopátricos. Em relação aos dados ecológicos, o FTFS e o tamanho das subunidades de alimentação tiveram valores baixos para todos os grupos de macacos-prego, indicando que as fontes de frutos não sustentam todo o grupo por ter recursos de pobre qualidade. Houve uma relação entre tamanho de subgrupo e padrão da oferta de alimento: quanto maiores e mais uniformemente distribuídas as fontes de frutos no habitat das quais os animais estavam se alimentando, maior o subgrupo. Portanto, os macacos-prego do PECB ajustam o tamanho de grupo para reagir às variações ecológicas, em função de baixa disponibilidade de frutos e assim, essa grande flexibilidade permite que eles se adaptem a novos ambientes e se comportem de modo a aumentar sua aptidão. / The primate order presents a great diversity of social organization, from species considered solitary to those where the individuals of a group remain together all the time. Capuchin monkeys (Cebus spp.) generally live in stable and cohesive groups, without the formation of subgroups. However, their social organization can be more flexible. Two former studies on two populations of Cebus nigritus from the Atlantic Forest suggested the occurrence of subgrouping, but the authors could not conclude whether the observed processes were due to a permanent division of a large group or whether these populations were actually fission-fusion societies. The objective of this study was to investigate whether the capuchin monkey groups of the State Park Carlos Botelho (PECB) can be characterized as a fission-fusion society or subgrouping is a temporary strategy prior to a permanent division of a large group. From January 2003 to March 2006, two social groups were followed, with the adult individuals recognized. Data from other groups were collected in an opportunistic way. To verify whether the group was foraging in a cohesive way or divided in subgroups, a census of the group members was performed at each hour and, and the number of adult males, adult females and juveniles were counted to analyze the composition of the subgroups. In order to evaluate the food availability 153 pitfall traps were distributed along the long home range. Data about behavior (locomotion, rest, foraging and locomotion more foraging) and diet (fruits, invertebrates and leaves) were registered by scan sampling every 5 minutes. The depletion time of fruit sources (FTFS) and the number of individuals that fed together in the same tree (size of feeding subunity) were recorded. All the capuchin monkey groups observed in the PECB were organized as a fission-fusion society, splitting into subgroups of variable size and composition, with preferential associations between pairs of male and female, composition multi-male/multi-female and absence of dominance among females. All these observed characteristics are similar to chimpanzees and neotropical primates which present fission-fusion. The main difference among capuchin monkeys and these species are the sexual dispersion from natal group. In capuchin monkeys the males migrate among groups, while in fission-fusion societies the males are philopatric. In relation to the ecological data, the FTFS and the feeding subunity size had low values for all the capuchin monkey groups, indicating that the fruit sources at PECB are poor quality resources and do not support all group members. There was a relation between subgroup size and pattern of food availability: the largerer and more uniformly distributed the fruit sources the animals were feeding, the larger the subgroup. Therefore, capuchin monkeys at PECB adjust their group size in response to the ecological variations, due to the low fruit availability and thus, this great flexibility allows them to adapt to a new environment and to behave in order to increase their fitness.
39

En svår nöt att knäcka : Verksamma förskollärares upplevelser om vaken-vilan / A hard nut to crack : Preschool teachers´experiences about awake-rest

Ericsson, Therese, Wallberg, Rebecca January 2018 (has links)
Syftet med denna studie är att undersöka förskollärares upplevelser av vaken-vila. Kvalitativaintervjuer med tio förskollärare har genomförts och resultatet har analyserats med IPA. Tvåhuvudteman har framtolkats. Konceptet vaken-vila visar hur förskollärarna uttrycker att vaken-vilaska vara en stund för lugn och återhämtning samtidigt som deras upplevelser skiftar, den upplevs bådesom bra och trevlig men också som svår och stressframkallande. Organisation av vaken-vila handlarom förskollärarnas upplevelser av möjligheter och begränsningar för aktiviteten i relation tillbarngruppsstorlek, personaltäthet, lokal och material. Studiens slutsatser är att vaken-vilan upplevssom en aktivitet med många dimensioner. Strukturella svårigheter såsom brist på personal i relationtill antal barn i förskolan skapar organisatoriska begränsningar för vad aktiviteten vaken-vila kaninnehålla. Detta leder till att några av förskollärarna upplever stress i samband med aktiviteten. Vi kangenom tolkning av vårt resultat se att vaken-vilan verkligen är det vår rubrik påstår: en svår nöt attknäcka. / The purpose of this study is to examine preschool teachers experiences of awake-rest. Qualitativeinterviews with ten preschool teachers have been conducted and the results have been analyzed withIPA. Two main themes have been interpreted: The concept of awake-rest and The organization ofawake-rest. Our interviews revealed that the concept of awake-rest is a moment where preschoolteachers wants there to be calm while allowing for mental recovery. But their experiences of awakerestis of different character. Feeling the activity as both good and enjoyable but also as difficult andstress related. The organization of awake-rest regards preschool teachers experiences about therestrains and opportunities of the activity in relation to child group size, number of staff, environmentand materials. The study concludes that the awake-rest is experienced as an activity with manydimensions. Structural difficulties such as lack of staff in relation to the number of children createsorganizational limitations on what the activity awake-rest may contain. This leads to some of thepreschool teachers experiencing stress in connection with the activity. We can, by interpreting ourresults, see that the awake-rest is really what our headline claims: a hard nut to crack.
40

Uso de habitat e comportamento do boto-cinza sotalia guianensis em uma zona estuarina do estado de Sergipe, nordeste do Brasil a biotecnologia vegetal como alternativa para a cotonicu

Lima, Maisa de Souza 13 December 2010 (has links)
Made available in DSpace on 2014-12-17T15:37:03Z (GMT). No. of bitstreams: 1 MaisaSL_DISSERT.pdf: 2026475 bytes, checksum: e8193d7fef1558e71f648e1ff98597f9 (MD5) Previous issue date: 2010-12-13 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / To clarify the functional mechanisms of habitat use is necessary to analyze it in conjunction with the conduct performed by animals. The occurrence, distribution and use of space are characteristic of a species resulting from habitat selection that is in search of conditions favorable to its survival. One can relate the physical and biological factors of the environment with the ecological characteristics of the species, since these factors act by regulating the ecological success of organisms, and from there you can get important information about the habitat use and behavior of individuals. This study aimed to characterize the use of habitat and diurnal activity expressed by the Guiana dolphin, Sotalia guianensis in an estuarine area of Sergipe state, Brazil, analyzing the influence of tide and time days on the occurrence of animals and behavior s state, and group s size and composition in this cetacean species. From March 2009 to February 2010, focal groups observations of dolphins were made from fixed - point and records snapshots of data taken every 5 min. in the interval from 6 a.m to 6 p.m, in alternating shifts. The results showed that the constant presence of animals in the area of the Sergipe River estuary indicates that this is an important area of occurrence of S. guianensis, which use the region mainly in the morning, at low tide and as a feeding. As in other regions of northeastern Brazil, small groups formed 2-12 individuals were most common, with adults and immatures. The high frequency of immature animals may indicate that this area of the estuary is used as brood area and parental care of pups and young animals, since the immature animals were very associated with adults and monitoring the activities of foraging / feeding may be related to a form of learning or training of such behavior / Para esclarecer os mecanismos funcionais do uso do habitat ? preciso analis?-lo conjuntamente ao comportamento realizado pelos animais. A ocorr?ncia, distribui??o e uso do espa?o s?o caracter?sticas de uma esp?cie decorrentes da sele??o do habitat que esta faz em busca das condi??es favor?veis ? sua sobreviv?ncia. Podem-se relacionar os fatores f?sicos e biol?gicos do ambiente com as caracter?sticas ecol?gicas da esp?cie, j? que estes fatores atuam regulando o sucesso ecol?gico dos organismos, e a partir disso ? poss?vel obter importantes informa??es sobre o uso de habitat e do comportamento dos indiv?duos. Assim, este estudo objetivou caracterizar o uso de habitat e o comportamento diurno expresso pelo boto-cinza, Sotalia guianensis, na zona estuarina do Rio Sergipe, nordeste do Brasil, analisando a influ?ncia do estado da mar? e hora do dia sobre a ocorr?ncia dos animais e dos estados de comportamento, bem como verificar o tamanho e composi??o dos agrupamentos nesta esp?cie de cet?ceo. Para isso, de Mar?o de 2009 a Fevereiro de 2010, observa??es focais dos agrupamentos de botos foram feitas a partir de ponto - fixo e os registros instant?neos dos dados efetuados a cada 5 min., no intervalo das 6:00h as 18:00h, em turnos alternados. Os resultados mostraram que a constante presen?a dos animais na zona estuarina do Rio Sergipe indica que esta ? uma importante ?rea de ocorr?ncia de S. guianensis, os quais usam a regi?o principalmente no turno da manh?, em n?veis baixos de mar? e como ?rea de alimenta??o. Como em outras regi?es do nordeste do Brasil, pequenos agrupamentos foram mais comuns, formados por 2 a 12 indiv?duos de ambas as classes de idade, adultos e imaturos. A alta freq??ncia de animais imaturos pode indicar que esta ?rea do estu?rio seja utilizada como ?rea de cria e cuidado parental dos filhotes e animais jovens, j? que os imaturos estiveram bastante associados aos adultos e o acompanhamento nas atividades de forrageio/ alimenta??o pode estar relacionado a uma forma de aprendizagem ou treinamento desse comportamento

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