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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.
21

Behavioural responses in mice exposed to predator odour components

Sjöström, Desirée January 2014 (has links)
It is essential for prey species to be able to detect predators to avoid them. The sense of smell is used by a number of prey species for this purpose. The aim of the present study was to assess if one of the odourants that make up a predator odour is sufficient to induce a behavioural response in mice (Mus musculus). Two predator odourants were used, 2,2-dimethylthietane and methyl-2-phenylethyl sulfide, which are both found in the secretions of natural predators of mice. An odourant found in fruits, n-pentyl acetate, was also used. All three odourants were presented at a concentration that was a factor of 100 above the olfactory detection threshold of mice. Ten adult predator-naïve CD-1 mice were individually put in a two-compartment chamber one of which contained an odourant while the other contained a near-odourless solvent (diethyl phthalate). The results indicated that methyl-2-phenylethyl sulfide was actively avoided by the mice. Towards 2,2-dimethylthietane and n-pentyl acetate, in contrast, the mice behaved indifferent. Further, the results suggest a significant correlation between the number of switches between the two compartments of the test chamber and the test sessions when the animals were presented with n-pentyl acetate, but not when they were presented with the predator odourants. The results support the notion of an innate fear response towards the predator odourant methyl-2-phenylethyl sulfide in mice, but further studies with more animals and different concentrations of the odourants are necessary.
22

Adolescent stress and social experiences : developmental antecedents of adult behavioural responses to unfamiliar stimuli and the underlying neuroendocrine mechanisms

Emmerson, Michael George January 2017 (has links)
During adolescence, animals leave the natal home and interact with potentially threatening stimuli (i.e. stressors), e.g. unfamiliar environments and conspecifics. Adolescent stressors can result in fewer interactions with unfamiliar stimuli in adulthood, plausibly due to sustained effects of glucocorticoid exposure on stress physiology (e.g. glucocorticoid secretion and receptor expression). The current thesis tested the hypothesis that adolescent glucocorticoid exposure and social experiences act as stressors by quantifying the effects of the adolescent experiences on behavioural responses to unfamiliar stimuli and the underlying neuroendocrine mechanisms when in adulthood using two captive species, zebra finches and rats. In study one, adolescent zebra finches were dosed with the glucocorticoid corticosterone. In adulthood, birds dosed with corticosterone in early adolescence took longer to enter an unfamiliar environment when tested individually and had lower expression of the glucocorticoid receptor GR in the hippocampus and hypothalamus, brain regions that regulate stress responses. Glucocorticoids therefore appear to be an endocrine mechanism behind the long-term effects of adolescent stress. Subsequent studies explored whether higher social density and more unfamiliar social interactions during adolescence act as stressors. In study two, early adolescent zebra finches were housed in groups varying in conspecific number and density. In adulthood, females raised in larger groups secreted a higher stressor-induced corticosterone concentration and, if raised at lower density, spent more time in an unfamiliar environment when group housed. In study three, adolescent female rats were housed in familiar pairs or exposed to unfamiliar conspecifics. Unfamiliar adolescent interactions had no effects on responses to unfamiliar environments or stress physiology in adulthood, but heightened ultrasonic call rates. In this thesis, adolescent social experiences do not act like stressors, but modulate (especially female) social behaviour. Adolescent stressors and social experiences therefore have distinct effects on responses to unfamiliar stimuli and stress physiology that are maintained into adulthood.
23

Cognition in narrow-striped mongooses, Mungotictis decemlineata, a Malagasy carnivore species

Rasolofoniaina, Bako Nandrianina 13 February 2020 (has links)
No description available.
24

Consumer associations and preferences surrounding insects as food : a descriptive study of South Africa and Sweden / Konsumenters associationer och preferenser kring insekter som mat : en beskrivande studie om Sydafrika och Sverige

Hallin, Fredrik January 2020 (has links)
Insects as food is a subject that has gained a lot of attention in recent time. In order for insect-food to become popular in the west, where insects are currently not consumed, research has to be done on how consumers perceive insect-food, and which consumer groups that eat insects in other countries. This will give a picture of how insects can and should be used on the Swedish market. The purpose of the thesis is to research consumer associations and preferences of insect consumption in Sweden and South Africa. The study examines the question of which consumer groups that eat insects in either country, what associations and preferences consumers have of insect-eating, and how insects can be used in food in the future. An online questionnaire concerning associations, preferences and experiences of insect consumption was distributed in both countries, and was answered by 73 participants. Three producers of insects were interviewed in Sweden and South Africa to get an understanding of the production stage of insects and their experiences of the industry and the consumers, now and in the future. Entomophagy was not found to be more prevalent in any group in neither Sweden nor South Africa. When used in food, consumers prefer insects to be ground into a powder. The South African respondents who had previously eaten insects mainly as an everyday meal preferred the insects to be served whole while the others preferred the insects to be ground into a powder. Insects are often associated with being nutritious, cheap, and being environmentally friendly, as well as with unfamiliarity and disgust. / Insekter som mat är ett ämne som fått mycket uppmärksamhet på senare tid. För att insektsmat ska kunna slå igenom i västvärlden, där insekter i nuläget inte konsumeras, måste man ta reda på hur insektsmat uppfattas av konsumenter, och vilka konsumentgrupper som äter insekter i andra länder. Detta ger en bild av hur insekter kan och bör användas på den svenska marknaden. Syftet med denna uppsats är att undersöka associationer och preferenser rörande insektsmat i Sverige och Sydafrika. Studien undersöker vilka konsumentgrupper som äter insekter i de två länderna, vad konsumenterna har för associationer och preferenser för insektsätande, och hur insekter kan användas i mat i framtiden. En webbaserad enkät skickades ut till konsumenter i vardera land, och besvarades av totalt 73 deltagare. Frågorna handlade om associationer, preferenser och erfarenhet i förhållande till insektsätande. Tre insektsproducenter intervjuades i Sverige och Sydafrika för att ge en förståelse för produktionen samt deras tankar och erfarenheter av branschen och konsumenterna, nu och i framtiden. Oberoende av i vilket land undersökningen genomfördes var det inte möjligt att karaktärisera några konsumentgrupper där entomofagi var mer vanligt förekommande. När insekter används i mat föredrar konsumenter att dessa mals ned till ett pulver. Insekter associeras ofta med att vara näringsrikt, billigt och miljövänligt, samt med ovana och äckel.
25

Understanding the role of human microbiota on sensory perception

Menghi, Leonardo 06 June 2023 (has links)
While consumer awareness of benefits of adequate nutrition has noticeably surged in recent years, developing countermeasures against improper eating habits still represents a public health priority in view of the growing prevalence of diet-related diseases. Eating behaviours are complex phenomena driven by a spectrum of biological and environmental factors, wherein (chemo)sensory perception is reckoned amongst the most influential. Analogously, chemosensation is affected by a myriad of determinants, and this warrants the commonly observed large variation in how tastes and smells are perceived among individuals. Given how such variability intimately relates to dietary habits, deciphering its underlying mechanisms is paramount to promoting healthier food choices. In this vein, emerging evidence suggests that human eating behaviours can also be affected by interactions between the gastrointestinal microbiota and the chemosensory systems. Despite growing interest, the sensory-oriented microbiome field suffers from obvious limitations due to its recent emergence. As a result, little efforts has been devoted to elucidating: a) the associations between the oral microbiota and olfaction or known psychological mediators of sensory perception; b) the links between the distal gut microbiota and taste functioning; c) the consequences of interactions between chemosensation and the gastrointestinal microbiota on dietary intakes. Against this backdrop, this thesis aimed at expanding the current knowledge on the interplays between domains of sensory perception and the gastrointestinal microbiota and how these might mirror variations in habitual food habits. In detail, four studies probing the associations a) between a psychosocial correlate of sensory perception (food neophobia), olfaction (Chapter 2) and the oral microbiota (Chapter 3); and b) between distal gut (Chapter 4) or oral (Chapter 5) microbiota, taste functioning and dietary intakes are here presented. In Chapter 2 and 3, a healthy cohort of 83 individuals (57.8 % women; aged 22-68 yo) remotely filled out the common Food Neophobia Scale and the trait anxiety subscale of the State-Trait Anxiety Inventory prior to providing a salivary sample for subsequent metataxonomic analysis (16S rRNA gene sequencing). Next, volunteers were tested for orthonasal olfactory functioning via the Sniffin’ Sticks battery, and monitored for retronasal aroma release while consuming a strawberry jelly candy by nose-space analysis (Selected-Ion Flow-Tube Mass Spectrometry). In Chapter 4 and 5, instead, 100 young adult volunteers (52 % women; aged 18-30 yo) attended a 7-day lasting remote protocol where responsiveness to genetically-mediated bitterness of 6-n-propylithiuracil (PROP), hedonics and intensity of oral sensations elicited by ten commercially-available food products, a battery of food-related psychological traits, a 4-day food record, and one salivary and one stool sample (sequenced by targeting the 16s rRNA gene) were collected. Overall, results substantially strengthen past evidence suggesting: a) that pronounced neophobic tendencies translate into higher levels of (negative) emotional activation or arousal towards foods; b) the existence of homogenous groups of individuals with generalized hypergeusia towards oral stimulations; c) that hyperresponsiveness to a peculiar taste quality is a barrier to the intake of foods evoking such sensation; d) that habitual consumption of dietary fibers and simple carbohydrates can shape both the gut and oral microbial ecology, respectively. Intriguingly, food neophobia and poor olfaction were positively associated with oral microbial markers of dysbiosis (e.g., Porphyromonas gingivalis), whilst a Clostridia-enriched salivary microbiota co-occurred with low responsiveness to alarming oral sensations (astringency, bitter, sour) elicited by real foods. Similarly, an ample panel of commensal gut bacterial genera mainly allocated to the families Lachnospiraceae and Ruminococcaceae was found to be enriched in individuals exhibiting lower acuity to both tastes (bitter, salty, sour, sweet) and trigeminal sensations (astringent, pungent). Besides taxonomically annotating a range of microbial taxa tied to sensory perception, putative metabolic pathways used by salivary and gut microbial communities to modulate taste perception were inferred and discussed. To conclude, this thesis supports the notion that the gastrointestinal microbiota is an additional candidate to explain interindividual variations in taste and smell perception, and provides novel important insights into the aetiology of eating behaviours. More importantly, this work also offers methodological cues to robustly assess the associations between chemosensation and host-related non genetic factors, and paves the way for future interventional studies targeting the efficacy of sensory-related microbial taxa as potential modulators of dietary habits.
26

Stálost objektu jako metoda pro výzkum vyšších kognitivních funkcí primátů / Object permanence as a method to study higher cognitive functions of primates

Englerová, Kateřina January 2014 (has links)
Object permanence is a cognitive ability, which allows individual to realize the existence of an object even it is not directly accessible to its senses. This ability is essential for successful using of complex cognitive operations. Object permanence is qualitatively and gradually change throughout the development of a child. Congruently, it is not developed to the same level in various species of animals. The aim of this study is to study object permanence in naive rhesus monkeys (Macaca mulatta), because there is still some uncertainty about the development of this ability in macaques. Our results show that the naive subjects do not have the highest stage of object permanence (and they do not use representative strategy to solve the tasks), however, other results of our team suggest that more experienced individuals are able to achieve the highest stage under certain circumstances. We show that experimental design used to test object permanence can be modified and used also for studying of other cognitive abilities. We test the preferences of macaque monkeys toward novel non-food stimuli. The reactions of different species of animals can vary. The reactions depend on the type of stimuli (food or non-food), but also on the ecology and ethology of the species. Age, sex and personality of the...
27

Explorace, neofobie a potravní konzervatismus u sýkor / Exploration, neophobia and dietary conservatism in tits (Paridae)

Beranová, Eliška January 2012 (has links)
Neophobia and exploratory behaviour are two processes applied in great measure in birds' reactions towards novel stimuli. The specific demonstration of these two processes may differ between different species of birds as well as within them. We compared neophobia and exploratory behaviour in two species of tits (Paridae). Adult Great tits (Parus major) and Blue tits (Cyanistes caeruleus) did not differ neither in exploring novel environment and novel object nor in neophobia towards novel object near food. We have found great differences between juveniles of these two species. Juvenile Blue tits were more neophobic towards both novel objects. Age, sex and personality affected some differences within tested species. We tested whether there exist any differences in reactions towards novel food between and within species. We used red painted mealworm (larvae of Tenebrio molitor), house cricket (Acheta domestica) and aposematic bug (Pyrrhocoris apterus) as novel food. Adult wild-caught tits with plentiful experience with various feeds did not differ in reaction towards these types of novel food. In contrast hand-reared juvenile tits differed quite a lot. Juvenile Blue tits were more neophobic than juvenile Great tits towards all three types of novel food. We found dieraty conservatism, phenomenon...
28

Interaction entre dispersion et syndromes comportementaux : causes et conséquences : approche empirique dans une population fragmentée de passereaux / Interaction between dispersal and behavioural syndromes : causes and consequences : empirical approch in a fragmented population of passerine birds

Daniel, Grégory 15 December 2015 (has links)
La dispersion est un trait d'histoire de vie clé pour les processus écologiques et évolutifs dans les populations naturelles. Les dernières recherches se sont notamment focalisées sur les corrélations entre traits comportementaux et la dispersion, ceci afin de mettre en évidence des syndromes comportementaux de dispersion, tout en démontrant la base génétique de la dispersion. Les dispersants ne seraient donc pas une part aléatoire d'une population, mais des individus montrant des stratégies particulières qui augmenteraient leur chances de succès. Cette thèse s'est orientée vers trois objectifs de recherche majeurs. Le premier est la mise en évidence d'une base génétique de la probabilité de disperser dans une population fragmentée de gobe-mouches à collier Ficedula albicollis. Les résultats nous ont montré, au-delà de l'estimation de la base génétique de la dispersion, une distribution spatiale non aléatoire de l'apparentement dans cette population, qui pourrait être dû à des effets génétiques sur les règles de décision de choix de l'habitat. Le deuxième s'intéresse à la corrélation phénotypique et génétique entre le comportement de dispersion natale et le comportement de défense du nid, chez le martinet alpin Tachymarpis melba. Nous avons montré que la dispersion natale et le comportement de défense du nid sont négativement corrélés au niveau phénotypique mais aussi génétique dans ces populations. Enfin, le troisième nous à conduit à tester l'existence de syndromes comportementaux de dispersion, c'est-à-dire si les dispersants présentent un profil comportemental particulier, leur permettant en particulier de coloniser de nouveaux sites, chez le gobe-mouche à collier / Dispersal is a key like history trait for ecological and evolutionary processes in wild population. The last researching particularly focused on the correlation between behavioural trait and dispersal, in order to emphasize the existence of behavioural syndromes of dispersal, and on the estimation of the genetic basis of the dispersal behaviour. Dispersant individuals could not be a random part of the population, but individuals showing particular strategies, that help them to succeed in their dispersal attempt. This thesis has three main aims of research. The first is to show a genetic basis of the dispersal propensity in a fragmented population of collared flycatchers (Ficedulla albicollis). We shown not only the genetic bases of the dispersal, but also a non-random spatial distribution of relationship between individuals in this population, that might be due to genetic effects on the decision rules of habitat choice in this population. The second aim concerns phenotypic and genetic correlation between the natal dispersal and a behavioural trait, the nest-defense behaviour, in the alpin swift (Tachymarpis melba). We shown that natal dispersal and nest-defense behaviour are negatively correlated at a phenotypic level, but also at a genetic level in theses populations. Finally, the third aim attempt to test the existence of behavioural syndrome of dispersal, that is if dispersant individuals have a particular behavioural profile, which enable them to colonize new sites, in the collared flycatcher
29

Interaction between dispersal and behavioural syndromes - empirical approach in a fragmented population of passerine birds

Daniel, Gregory January 2015 (has links)
Dispersal is a key life history trait for ecological and evolutionary processes in wild populations. The latest research has particularly focused on the correlation between behavioural traits and dispersal, in order to emphasize the existence of behavioural syndromes of dispersal, and on the estimation of the genetic basis of the dispersal behaviour. Dispersing individuals are not a random part of the population, but are individuals showing particular strategies, that help them to succeed in their dispersal attempt. This thesis has three main aims of research. The first is to show a genetic basis of the dispersal propensity in a fragmented population of collared flycatchers (Ficedulla albicollis). We show, not only, the genetic bases of the dispersal, but also a non-random spatial distribution of relationship between individuals in this population, that might be due to genetic effects on the decision rules of habitat choice in this population. The second aim concerns phenotypic and a genetic correlation between the natal dispersal and a behavioural trait, the nest-defense behaviour, in the alpin swift (Tachymarptis melba). We showed that natal dispersal and nest-defense behaviour were negatively correlated at a phenotypic level, but also at a genetic level in these populations. Finally, the third aim attempts to test the existence of a behavioural syndrome of dispersal, that is if dispersing individuals have a particular behavioural profile, which enable them to colonize new sites, in the collared flycatcher. / <p>The exmination will be videolinked to seminar room 1003 Evolutionary Biology Centre, EBC, Uppsala University.</p>
30

Caracteriza??o da neofobia alimentar em crian?as de tr?s a seis anos

Medeiros, Rodrigo Tavares Pinheiro de 23 January 2008 (has links)
Made available in DSpace on 2014-12-17T15:36:52Z (GMT). No. of bitstreams: 1 RodrigoTPM.pdf: 546581 bytes, checksum: cb4f6e4119e4c8484b61656898e881ae (MD5) Previous issue date: 2008-01-23 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Alimentation is essential in life. Concerning omnivores, characterized by the necessity of a varied diet to satisfy their metabolic needs, it is extremely advantageous the assumption of new foods. However, the assumption of new unknown foods is, potentially dangerous, because of possible intoxications. In this sense, one of the most important behaviors related to reducing risks is the so called food neophobia, characterized by the rejection of new foods and/or an ingestion of very little amounts. The aim of the present study was to investigate if age, sex and socio-economical status were able to influence food neophobia. The neophobia has been described in a range of 3-6 years old children taken both from public and private schools within the city of Natal-RN. Four different type of ice-creams, each one characterized by a different flavor, have been utilized. Two flavors were known to the young and the remaining two flavor were new. We didn't find significant differences between the investigated variables. However, the exploitation of data from the survey conducted showed that the ease or not to accept new foods obtained, was correlated with the variables under the same guidelines observed in literature. Aspects related to the stimulus used probably eased the neophobic answer. Then, it is suggested that the food neophobia can be influenced by sex, age and socioeconomic factors of individuaIs. Neophobia tends to be more common in girls, with ages between three to four years old and with a low leveI socioeconomic. In this sense, given the importance of kid neophobic reaction to the development of dietary patterns of other life's stages, it is necessary to make further studies to better explain this phenomenon. Given the pivotal role of food neophobia to the development of alimentary habits within all ages of life, other studies will be necessary for a better comprehension of such phenomena. Key-words: food neophobia; Evolutionary Psychology;children food intake; diet restriction; children's diet development / A alimenta??o ? essencial para a vida. Para os on?voros, que necessitam de uma dieta variada para conseguir suprir suas necessidades nutricionais, ? extremamente vantajoso incluir novos itens ? dieta. Contudo, ingerir alimentos desconhecidos pode ser perigoso, em raz?o da possibilidade de intoxica??o. Neste sentido, um dos comportamentos que auxiliam na redu??o dos riscos decorrentes da ingest?o de itens alimentares desconhecidos ? a neofobia alimentar, caracterizada pelo ato de recusar ou ingerir pequenas quantidades de um alimento novo. Este trabalho teve por objetivo investigar a influ?ncia da idade, do sexo e das caracter?sticas socioecon?micas dos indiv?duos na neofobia alimentar. Para isto, buscamos caracterizar o fen?meno neof?bico em crian?as de tr?s a seis anos de idade, oriundas de escolas p?blicas e particulares de Natal-RN. O alimento escolhido para o experimento foi sorvete, em quatro sabores distintos, sendo dois sabores conhecidos pelas crian?as e dois novos. Os resultados demonstraram n?o haver diferen?as em fun??o das vari?veis de sexo, idade e fatores socioecon?micos, quando avaliamos a escolha dos sabores do sorvete. Entretanto, a explora??o dos dados do question?rio realizado com os pais demonstrou que a facilidade ou n?o em aceitar novos alimentos obtida, se correlacionava com as vari?veis nas mesmas orienta??es observadas na literatura. Aspectos ligados ao alimento-est?mulo utilizado provavelmente atenuaram a resposta neof?bica. Com base neste ?ltimo dado, sugere-se que a neofobia alimentar pode ser prevista em fun??o de caracter?sticas de sexo, idade e fatores socioecon?micos dos indiv?duos, tendendo o fen?meno neof?bico a ser mais freq?ente em meninas, de tr?s a quatro anos e com um n?vel socioecon?mico mais baixo. Neste sentido, dada a import?ncia da rea??o neof?bica infantil para o desenvolvimento do padr?o alimentar das demais fases da vida, faz-se necess?ria a realiza??o de novos estudos para que possam a esclarecer melhor este fen?meno. Palavras-chave: neofobia alimentar, Psicologia Evolucionista; alimenta??o infantil; restri??o da dieta; forma??o da dieta infantil

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