Obesity is a growing public health issue with few effective treatments. Many of the human genes involved in weight regulation have homologues in other species. In Drosophila melanogaster, 11-cis-vaccenyl acetate (cVA) is a pheromone shown to affect both aggression and feeding behaviour. The aim of this study was to investigate the effect of cVA exposure on gene expression in wild type flies and to confirm crosses with genetic knockouts in the cVA pathway. The genes studied in the wild type flies were Akh (homologue of glucagon), Dilp2,-3 and -5 (homologues of insulin), Dsk (homologue of cholecystokinin), sNPF (homologue of neuropeptide Y) and TβH. The knockout genes studied were Or65a, Or67d and TβH. RNA was extracted from whole heads, cDNA synthesis was performed and the cDNA was then used in SYBR Green RT-qPCR. The knockout genes were not confirmed, due to methodological problems. The expression of Dilp3, Dilp5 and Dsk were significantly lower in the experimental flies, the expression of the other genes where not affected. The results indicate that exposure to cVA affects the expression of some of the neuropeptides involved in weight regulation. Due to the methodological problems experienced, a recommendation is to confirm the data using different reagents.

Made available in DSpace on 2014-06-11T19:30:30Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-02-05Bitstream added on 2014-06-13T19:00:40Z : No. of bitstreams: 1 mendonca_fz_dr_jabo.pdf: 252500 bytes, checksum: 408129aa472ebef8a56e9b0e9cee1ef9 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Universidade Estadual Paulista (UNESP) / Tilápia-do-nilo, Oreochromis niloticus (Linnaeus, 1758), é uma das espécies de peixes que utilizam o substrato para construir ninho. Porém, muitas vezes são mantidas em tanques ou aquários sem substrato. Em estudo anterior, foi verificado que a presença de substrato reduz o desenvolvimento das gônadas, aumenta a agressividade, mas não afeta o crescimento. Assim, foi avaliada a escolha do peixe por diferentes substratos (areia, areia + concha, pedra e vazio – sem substrato removível) para medir o bem-estar e o efeito de tais substratos no comportamento reprodutivo e agressivo da tilápia-do-nilo. Os objetivos deste trabalho foram: testar a escolha de substrato para a construção de ninho na tilápia-do-nilo (Estudo I); testar o efeito do substrato sobre o desempenho reprodutivo (freqüência e latência para construção de ninho, freqüência e latência para a desova e índice gonadossomático) e indicadores bioenergéticos (taxa de crescimento específico e índice hepatossomático) (Estudo II); e testar o efeito do tipo de substrato no desafio social por meio dos níveis de esteróides sexuais (testosterona (T) e 11-cetotestosterona (11KT)), e no cortisol plasmático como um indicador de estresse (Estudo III). A escolha de substrato foi testada em grupos (1 macho e 2 fêmeas) formados por animais adultos. Os machos escolheram o substrato de areia para a construção do ninho. Os indicadores reprodutivos e bioenergéticos também foram avaliados nos mesmos substratos utilizados no Estudo I, mas cada tipo de substrato foi colocado em aquários separados, consistindo 4 tratamentos. Em cada réplica foram utilizados 2 machos e 3 fêmeas, mantidos durante 12 dias ou até 48 horas após a primeira desova. A freqüência de desova foi maior no substrato de areia do que no sem substrato removível. Já a freqüência de construção de ninho, foi menor no substrato... / The Nile tilapia, Oreochromis niloticus (Linnaeus, 1758), is one of fish species which use build nest on bottom substrate. However this species are usually reared in tanks or aquarium without substrate. We verified the influence of substrate on reducing of gonad development, enhance aggressiveness, but growth is not affected. Thus, we tested the fish choice for different substrates (sand, sand + shell, stone and empty - without substrate) in order to access welfare and the effects of such substrates on reproductive and aggressive behavior of Nile tilapia. Our goals in this study were: test the substrate choice to nest building (Study I); test the substrate effect on the reproductive fitness (frequency and latency to nest building, frequency and latency to spawning and gonadossomatic index) and on the bioenergetic indicators (specific growth rate and hepatossomatic index) (Study II); and test the influence of substrate type on the social challenge by analyzing sexual steroid levels (testosterone (T) and 11 – ketotestosterone (11KT)), and serum cortisol as a stress indicator (Study III). The substrate choice was tested in groups made by 1 male and 2 females adult fish. Sand substrate was significantly chosen by males to built nest. The reproductive and bioenergetics indicators were also evaluated for the same substrate used in the Study I, but each substrate type was kept in separated aquaria, performing 4 treatments. Groups of 2 males and 3 females were kept until 12 days or until 48 hours after the first spawning. The frequency of spawning was higher in the sand substrate than in no substrate treatment. The frequency of nesting was lower in the stone substrate than in sand and sand + shell substrates. The others reproductive and energetic indicators were similar between the treatments. The social contest and hormone levels were tested in the four substrates used in the former experiments... (Complete abstract click electronic access below)

The absence of a framework or policy to address bullying in South Africa compels the country to rely on pieces of legislation that are closely related to anti-bullying laws such as the Child Justice Act 75 of 2008 and Protection from Harassment Act 71 of 2011. Over-reliance on pieces of legislation creates challenges for victims of these bullying crimes because most of the relational aggression exerted towards victims goes unpunished. Some of the adolescents take the law into their own hands, thus, exacerbate and increases the complexity of bullying crimes. Due to advancements in Information and Communications Technology, bully-victim behaviour does not only take place in physical environments such as schools, but it takes place anywhere, anytime (24/7) on Mobile Social Networks. In 2011, a cyberbullying study by the Centre of Justice and Crime Prevention reported that 69.7% of the youth in South Africa falls in the category of bully-victims. This is alarming given that few studies focus on the role of bullyvictims in South Africa. The exact cause for mobile bully-victim behaviour is unclear, and previous studies have highlighted it is between aggressive behaviour and social integration. Therefore, this study examined aggressive behaviour and social integration to determine which of these two factors contribute the most to mobile bully-victim behaviour. Additionally, mobile social network features that enable this behaviour were investigated. The factors that lead to aggressive behaviour and social integration, resulting in mobile bully-victims, were identified through a literature review. Paper-based surveys were issued to Johannesburg high school adolescents. Johannesburg was mainly selected based on finding by previous studies, which highlighted that most of the online bullying and victimisation happens amongst adolescents in Johannesburg. After data was collected, the results were analysed using Statistica version 13.5. The analysis revealed that, indeed, both aggressive behaviour and social integration cause mobile bully-victim behaviour, however, social integration contributed more than aggressive behaviour. The findings also revealed that WhatsApp and Instagram were the most utilized social networks by mobile bullyvictims. There were no differences between males and females when it comes to mobile bullyvictim behaviour. The causes of mobile bully-victim behaviour that have been identified in this study can be used as a starting point to develop legislation/framework aimed at combating mobile bully-victim behaviour. Given that mobile bully-victims are more suicidal and suffer from depression, psychologists and therapists can use the knowledge obtained from this study to develop psychological treatments specifically for mobile bully-victims.

Title: The aggressive behaviour in the NHL. Objectives: The aim of this thesis is to describe and analyze NHL fighting phenomenon. The analysis will be realized as a research study. At first, sources of the thesis will be described. Then, there will be mentioned contemporary backgrounds and theoretical points included theory of aggressiveness in everyday sport. Complex view on the aggressive behaviour within the NHL will be assigned as a main part of whole thesis. Main part will contain historical view, ongoing trends of NHL and brief glance to rules of the NHL. Methods: Basic information from the field of NHL fighting was compiled by direct method of research and by method of induction. Research via comparative method was used marginally. Results: Results of my thesis will help to understand and to light up aggressive behaviour phenomenon in NHL. This issue is not published in European countries. Thesis will help to why hockey players do fight, where are roots of the NHL brawling or how is an attitude of officials in NHL. Keywords: NHL, aggressiveness, aggressive behavior, brawl, fight, delinquency

Bronfenbrenners Process-Person-Context-Time model was used to examine the relationships among the process of negative parenting, the person characteristics of child temperament and early aggressive behaviour and the contexts of family income (in)adequacy and maternal depression from infancy to school entry and their effects on the outcome of aggressive behaviour in boys at school entry. The sample included 361 boys in two-parent families who participated in the Canadian National Longitudinal Survey of Children and Youth (NLSCY). Structural equation modeling was used with a repeated measures longitudinal design. The model explained 43% of the variance in boys aggressive behaviour at school age. The results indicated that, by preschool age, boys and mothers behaviours are well established, and that process, person, and context variables all influence the persistence of boys aggressive behaviour. The strength of the effects of these variables increased with their proximity to the developing child and decreased over time. By school age, concurrent effects were not significant. The addition of the contextual variables resulted in ill-fitting models. Modification indices suggested the ill fit was localized in modeling the persistence of maternal depression, and not in the relationship between maternal depression and the other variables in the model. Modification indices also suggested there may be reciprocal effects between boys aggressive behaviour and both negative parenting and maternal depression, but this was not tested. Future research using a cross-lagged panel design could clarify these relationships. This study contributes to a growing body of research on the development of aggressive behaviour in children and underscores the importance of examining the contribution of the multiple levels of process, person, context, and time to the development of aggressive behaviour. Findings of this study provide evidence that the effects of proximal processes and proximal contexts on the development of boys aggressive behaviour are strongest in infancy and toddlerhood, and their consequences extend through to school entry. Initiating prevention and intervention efforts in early childhood that provide parents-to-be and parents of young children with practical direction in ways to engage in positive and responsive interactions with their children would do more to reduce the development of aggressive behaviour in children than would later interventions aimed at changing entrenched behaviours in both parents and children.

Not many children report relationships with friends that are both close and conflictual. There is a paucity of research examining the trajectory of children's relationship closeness and conflict together over time. This is unfortunate because contentious relationships are related to cardiovascular problems, at least in young adults and because the trajectories of these two aspects of children's relationship quality over time is not understood. Therefore, two longitudinal data sets with younger (mean age 7.5 years at Time 1; four data points over 2 years) and older (mean age 9.9 years at Time 1; two data points over 1 year) children were studied. In both cohorts, measures of friendship quality and peer nominations of liking/disliking as well as overt and relational (older cohort) aggression were completed. Children who reported relationships high in both closeness and conflict were generally satisfied with their friendships; they were not more likely to end their friendships than were children who reported different levels of closeness and conflict (younger cohort). Both boys' and girls' relationship closeness increased over time according to growth curve analyses. The relationships of girls who remained in the same friendship, and who therefore provided ratings on the same friend at each time point, tended to increase in closeness at a different rate over time than the relationships of girls who provided ratings on different friends (younger cohort). Children who reported relationships high in closeness and in conflict were not more aggressive over time than were children who reported different levels of relationship closeness and conflict. However, girls' closeness and overt aggression tracked each other (increased) over time (younger cohort). Girls who reported low social support and negative interactions in their friendships increased the most in overt aggression over time (older cohort). Aggressive and nonaggressive children generally reported similar friendship quality (both cohorts), but the friendship closeness of chronically aggressive boys decreased over time (younger cohort). There were negligible friendship quality differences amongst the sociometric groups. The discussion centers on friendship quality changes in children's continuing friendships, the potential dire effects of turbulent friendships and the friendships of aggressive as well as controversial children.

Not many children report relationships with friends that are both close and conflictual. There is a paucity of research examining the trajectory of children's relationship closeness and conflict together over time. This is unfortunate because contentious relationships are related to cardiovascular problems, at least in young adults and because the trajectories of these two aspects of children's relationship quality over time is not understood. Therefore, two longitudinal data sets with younger (mean age 7.5 years at Time 1; four data points over 2 years) and older (mean age 9.9 years at Time 1; two data points over 1 year) children were studied. In both cohorts, measures of friendship quality and peer nominations of liking/disliking as well as overt and relational (older cohort) aggression were completed. Children who reported relationships high in both closeness and conflict were generally satisfied with their friendships; they were not more likely to end their friendships than were children who reported different levels of closeness and conflict (younger cohort). Both boys' and girls' relationship closeness increased over time according to growth curve analyses. The relationships of girls who remained in the same friendship, and who therefore provided ratings on the same friend at each time point, tended to increase in closeness at a different rate over time than the relationships of girls who provided ratings on different friends (younger cohort). Children who reported relationships high in closeness and in conflict were not more aggressive over time than were children who reported different levels of relationship closeness and conflict. However, girls' closeness and overt aggression tracked each other (increased) over time (younger cohort). Girls who reported low social support and negative interactions in their friendships increased the most in overt aggression over time (older cohort). Aggressive and nonaggressive children generally reported similar friendship quality (both cohorts), but the friendship closeness of chronically aggressive boys decreased over time (younger cohort). There were negligible friendship quality differences amongst the sociometric groups. The discussion centers on friendship quality changes in children's continuing friendships, the potential dire effects of turbulent friendships and the friendships of aggressive as well as controversial children.

The study analyses harmful behaviour towards self and others among students studying in the 5th to 12th grades. Harmful behaviour towards self and others is defined as substance use, suicidal and aggressive behaviour. This study explores an assumption that tobacco, alcohol and other drug abuse, suicidal and aggressive behaviour constitute one problem behaviour syndrome, as they perform the same functions in the life of an adolescent. The study is aimed to determine whether harmful behaviour towards self and others can be identified with the same psychosocial factors. Due attention is focused in the study on the changes of this behaviour from grades 5 to 12, in the duration of three years in different student groups. The empirical part of the dissertation presents a study of a large group of secondary school students during a period of 3 years. The results illustrate that substance use, suicidal behaviour and aggressive behaviour can be understood as a problem behaviour syndrome, but only in the girls’ group. Depressive mood, poor relations with teachers and negative learning attitudes predict all three forms of harmful behaviour towards self and others. Prevalence of this behaviour becomes increasingly evident during adolescence, but its different forms undergo different transformation processes. Changes in harmful behaviour towards self and others occur due to the age effect, but not the cohort effect. / Disertacijoje nagrinėjamas 5 – 12 klasių mokinių save ir kitus žalojantis elgesys, kuris apibrėžiamas kaip tabako, alkoholio, kitų narkotinių medžiagų vartojimas, agresyvus ir savižudiškas elgesys. Darbe tikrinama prielaida, kad šios save ir kitus žalojančio elgesio formos paauglystėje sudaro vieną elgesio konstruktą, nes atlieka tas pačias funkcijas paauglio gyvenime. Siekiama įvertinti, ar save ir kitus žalojantis elgesys gali būti aprašytas tais pačiais psichosocialiniais veiksniais. Darbe didelis dėmesys skiriamas šio elgesio kitimams nuo 5 iki 12 klasės ir per tris tyrimo metus skirtingose mokinių amžiaus grupėse. Empirinėje darbo dalyje pristatomas 3 metus trukęs didelės mokinių grupės tyrimas. Išanalizavus rezultatus, nustatyta, kad tabako, alkoholio, kitų narkotinių medžiagų vartojimas, agresyvus ir savižudiškas elgesys gali būti suprantami kaip vieno elgesio konstrukto dalys, tačiau tik mergaitėms. Pablogėjusi nuotaika, prasti santykiai su mokytojais ir neigiamas požiūris į mokymąsi geriausiai nusako paauglių save ir kitus žalojantį elgesį. Šio elgesio kitimų analizė atskleidė, kad save ir kitus žalojančio elgesio paauglystės laikotarpiu daugėja, tačiau kinta jo pasireiškimo forma. Save ir kitus žalojančio elgesio kitimai atsiranda dėl amžiaus įtakos, bet ne dėl kohortos efekto.

Disertacijoje nagrinėjamas 5 – 12 klasių mokinių save ir kitus žalojantis elgesys, kuris apibrėžiamas kaip tabako, alkoholio, kitų narkotinių medžiagų vartojimas, agresyvus ir savižudiškas elgesys. Darbe tikrinama prielaida, kad šios save ir kitus žalojančio elgesio formos paauglystėje sudaro vieną elgesio konstruktą, nes atlieka tas pačias funkcijas paauglio gyvenime. Siekiama įvertinti, ar save ir kitus žalojantis elgesys gali būti aprašytas tais pačiais psichosocialiniais veiksniais. Darbe didelis dėmesys skiriamas šio elgesio kitimams nuo 5 iki 12 klasės ir per tris tyrimo metus skirtingose mokinių amžiaus grupėse. Empirinėje darbo dalyje pristatomas 3 metus trukęs didelės mokinių grupės tyrimas. Išanalizavus rezultatus, nustatyta, kad tabako, alkoholio, kitų narkotinių medžiagų vartojimas, agresyvus ir savižudiškas elgesys gali būti suprantami kaip vieno elgesio konstrukto dalys, tačiau tik mergaitėms. Pablogėjusi nuotaika, prasti santykiai su mokytojais ir neigiamas požiūris į mokymąsi geriausiai nusako paauglių save ir kitus žalojantį elgesį. Šio elgesio kitimų analizė atskleidė, kad save ir kitus žalojančio elgesio paauglystės laikotarpiu daugėja, tačiau kinta jo pasireiškimo forma. Save ir kitus žalojančio elgesio kitimai atsiranda dėl amžiaus įtakos, bet ne dėl kohortos efekto. / The study analyses harmful behaviour towards self and others among students studying in the 5th to 12th grades. Harmful behaviour towards self and others is defined as substance use, suicidal and aggressive behaviour. This study explores an assumption that tobacco, alcohol and other drug abuse, suicidal and aggressive behaviour constitute one problem behaviour syndrome, as they perform the same functions in the life of an adolescent. The study is aimed to determine whether harmful behaviour towards self and others can be identified with the same psychosocial factors. Due attention is focused in the study on the changes of this behaviour from grades 5 to 12, in the duration of three years in different student groups. The empirical part of the dissertation presents a study of a large group of secondary school students during a period of 3 years. The results illustrate that substance use, suicidal behaviour and aggressive behaviour can be understood as a problem behaviour syndrome, but only in the girls’ group. Depressive mood, poor relations with teachers and negative learning attitudes predict all three forms of harmful behaviour towards self and others. Prevalence of this behaviour becomes increasingly evident during adolescence, but its different forms undergo different transformation processes. Changes in harmful behaviour towards self and others occur due to the age effect, but not the cohort effect.

No description available.