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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.
331

Impact of School-Wide Positive Behavior Intervention Supports for African American Males in American Public Schools

Luttrull, Pamelia D. 12 1900 (has links)
Research has shown that African American males are performing poorly in American public schools and are disciplined at a higher rate than other ethnic and gender groups. Positive Behavior Intervention Supports (PBIS) has a long history of success with individual students and more recently in school-wide settings. School-wide PBIS offers schools the ability to tailor their rules, rewards, and consequences to the specific needs and culture of a school. This descriptive and quantitative study sought to determine if implementation with fidelity of SWPBIS positively correlated to reduced disciplinary measures. The object of this study was to determine in what ways disciplinary rates for African American males differ in American public schools that identify as using SWPBIS with fidelity as compared to American public schools that do not implement SWPBIS with fidelity. Disciplinary rates examined included ISS, OSS single incident, and OSS multiple incidents. Descriptive findings indicated that schools that implement SWPBIS show a lower rate of ISS and OSS incidents for African American males. The quantitative findings did not yield a statistically significance between schools with fidelity of implementation of SWPBIS and schools without fidelity of implementation of SWPBIS.
332

Regenera??o ?ssea em camundongos : correla??o entre diabetes tipo 1 e menopausa experimental

Cignachi, Nat?lia Pradella 25 January 2018 (has links)
Submitted by PPG Odontologia (odontologia-pg@pucrs.br) on 2018-06-04T18:05:30Z No. of bitstreams: 1 NATALIA_PRADELLA_CIGNACHI_TES.pdf: 6840858 bytes, checksum: 8e5f3ae6a98395bf09135b6770903f35 (MD5) / Rejected by Sheila Dias (sheila.dias@pucrs.br), reason: Devolvido devido ? falta da capa institucional no arquivo em PDF. on 2018-06-14T14:34:13Z (GMT) / Submitted by PPG Odontologia (odontologia-pg@pucrs.br) on 2018-06-19T13:28:41Z No. of bitstreams: 1 NAT?LIA_PREDELLA_CIGNACHI_TES.pdf: 11102267 bytes, checksum: 121fbf4d2b9ae1c4a36e21d23ab3140d (MD5) / Approved for entry into archive by Sheila Dias (sheila.dias@pucrs.br) on 2018-06-27T14:32:32Z (GMT) No. of bitstreams: 1 NAT?LIA_PREDELLA_CIGNACHI_TES.pdf: 11102267 bytes, checksum: 121fbf4d2b9ae1c4a36e21d23ab3140d (MD5) / Made available in DSpace on 2018-06-27T14:43:00Z (GMT). No. of bitstreams: 1 NAT?LIA_PREDELLA_CIGNACHI_TES.pdf: 11102267 bytes, checksum: 121fbf4d2b9ae1c4a36e21d23ab3140d (MD5) Previous issue date: 2018-01-25 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / This thesis encompasses two parts: firstly, we compared the bone healing in female and male mice, after induction of type 1 diabetes (T1D); secondly, the bone regeneration was evaluated in a menopause model induced by bilateral ovariectomy (OVX), with or without T1D induction. For the part I, the animals (female and male) were initially assigned into two groups, namely control or T1D (elicited by streptozotocin; STZ). In the part II, the females were divided into four experimental groups: sham-operated or OVX, with or without STZ T1D induction. After T1D induction, a monocortical femoral defect was created. In either parts of the present study, we evaluated the effects of supplementation with vitamin D3 and/or insulin. In the second part, the effects of estrogen replacement were also analyzed. Following 21 days of bone defect creation, the animals were euthanized; the femurs and blood were collected for posterior analysis. Both T1D females and males presented a reduction in body weight gain, associated with hyperglycemia. There were no changes in the serum levels of the pro-inflammatory cytokines [interleukin-1? (IL-1?), tumor necrosis factor (TNF) and interferon-? (IFN-?)] in all the evaluated groups. T1D mice of both sexes presented a delayed bone regeneration, according to the histological and micro-CT assessment. The supplementation with vitamin D3 restored the bone healing in female and male T1D mice, reaching values close to controls. The insulin therapy improved the bone remodeling in T1D mice of both sexes, but the effects of this hormone were superior in males. The evaluation of osteoclast activity did not reveal significant differences among the experimental groups. Real time PCR revealed slight differences in the mRNA expression of two transcription factors related to osteoblast differentiation, namely runx2 and osterix, as measured in the area into the bone defect. A higher upregulation of both factors was seen in T1D males treated with vitamin D3. Conversely, vitamin D3-treated T1D females displayed an upregulation of insulin-like growth factor 1 (IGF-1), further indication sex-related differences for the treatments. Besides the experimental protocols described for the 12 part I of this thesis, in the part II, we also evaluated some behavioral locomotor parameters and serum levels of calcium and alkaline phosphatase. OVX animals presented increased body weight gain, accompanied by uterus atrophy. Otherwise, T1D induction elicited a reduction of body weight gain, which was more pronounced in OVX-T1D animals. Serum levels of alkaline phosphatase were divergent in the non-diabetic and T1D OVX animals. Calcium or cytokine levels were similar in all the experimental groups. The sham-operated T1D, the non-diabetic OVX and the OVX-T1D groups presented a delayed bone regeneration, as indicated by histological and micro-CT analysis. Estrogen replacement improved the bone healing in all OVX groups. There was a trend toward an upregulation of IGF-1 mRNA in non-diabetic OVX animals, which was not mirrored in OVX-T1D mice. Locomotor parameters remained unaltered, except by a general reduction of rearing numbers in T1D animals. / A presente tese est? dividida em duas partes: na parte I, comparou-se a regenera??o ?ssea em camundongos f?meas e machos, com diabetes do tipo 1 (T1D). Na parte II, foi avaliada a regenera??o ?ssea no modelo de menopausa experimental induzido por ovariectomia (OVX), com ou sem T1D. Na parte I, os animais (machos e f?meas) foram divididos em dois grandes grupos: controle e T1D (induzido por estreptozotocina; STZ). Na parte II, os animais foram divididos em quatro grandes grupos: f?meas falso-operadas e OVX, com ou sem T1D. Ap?s a indu??o do T1D, foi criado um defeito ?sseo monocortical no f?mur. Nas duas partes do trabalho, foram avaliados os efeitos da suplementa??o com vitamina D3 e/ou insulina. Na segunda parte, tamb?m se avaliou o efeito da reposi??o hormonal com estradiol. Decorridos 21 dias do procedimento da cria??o do defeito, os animais foram eutanasiados; o f?mur e o sangue foram coletados para an?lises posteriores. Tanto as f?meas, quanto os machos T1D, apresentaram uma redu??o do ganho de peso corporal, associado ? hiperglicemia. N?o houve altera??es nos n?veis s?ricos das citocinas pr?-inflamat?rias interleucina-1? (IL-1?), fator de necrose tumoral (TNF) ou interferon-? (IFN?). Os animais T1D, de ambos os sexos, apresentaram um comprometimento na regenera??o ?ssea, como demonstrado pelas an?lises histol?gicas e de micro-CT. A suplementa??o com vitamina D3 reestabeleceu a regenera??o ?ssea em f?meas e machos T1D, apresentando valores pr?ximos aos encontrados nos animais do grupo controle. A terapia com insulina melhorou a remodela??o ?ssea nas f?meas e machos T1D; por?m, os efeitos foram mais pronunciados nos machos. A avalia??o da atividade osteocl?stica n?o revelou diferen?as significativas entre os grupos experimentais, ap?s a indu??o de T1D, em machos ou f?meas. Os resultados do PCR em tempo real para runx2 e osterix (dois fatores de transcri??o relacionados aos osteoblastos), no tecido ?sseo, n?o demonstraram nenhuma diferen?a significativa, exceto por um aumento nos n?veis de RNAm dos dois fatores nos camundongos machos T1D, que receberam suplementa??o com vitamina 10 D3. Por outro lado, f?meas T1D que receberam vitamina D3 apresentaram um aumento na express?o dos n?veis de RNAm para o fator de crescimento semelhante ? insulina do tipo 1 (IGF-1), quando comparado com os machos que tiveram o mesmo tratamento, sugerindo assim, diferen?as relacionadas ao sexo. Al?m das an?lises j? mencionadas anteriormente, na parte II da tese, par?metros comportamentais e n?veis s?ricos de c?lcio e fosfatase alcalina tamb?m foram analisados. Os resultados da segunda parte do trabalho demonstraram que os animais submetidos a OVX tiveram um aumento do peso corporal, com atrofia uterina. Em contrapartida, quando foi induzido T1D, houve uma diminui??o do peso corporal mais acentuada no grupo OVX que no grupo falso-operado. Os animais falso-operados e OVX T1D apresentaram hiperglicemia, confirmando o desenvolvimento do diabetes. Os n?veis s?ricos de fosfatase alcalina foram divergentes entre os grupos n?o-diab?ticos OVX e OVX T1D. N?o houve varia??es dos n?veis de c?lcio. Os animais falso-operados T1D, n?o diab?ticos OVX e OVX T1D apresentaram preju?zos similares na regenera??o ?ssea, como observado pelas an?lises histol?gicas e imagens de micro-CT. A reposi??o com estradiol melhorou a cicatriza??o ?ssea nos animais n?o-diab?ticos OVX e OVX T1D. Houve uma tend?ncia ao aumento nos n?veis de RNAm de IGF-1 no grupo OVX, o que n?o foi observado quando da associa??o de T1D e menopausa. N?o foram observadas diferen?as na atividade locomotora dos animais com T1D e/ou OVX, a n?o ser por uma diminui??o no n?mero de rearings no grupo falso-operado T1D, independente do tratamento com vitamina D3, insulina e estradiol, de forma isolada ou em associa??o.
333

A expressão do medo condicionado em ratos com fenótipos de baixa e alta reatividade emocional: modulação serotoninérgica cortical e subcortical sobre as diferenças de gênero / The conditioned fear expression in rats with low- or high-anxiety phenotype: cortical and subcortical 5-HT influence on gender differences

Ferreira, Renata 08 August 2014 (has links)
Extensos dados na literatura têm assinalado a importância da serotonina (5-HT) na modulação de comportamentos de medo e ansiedade em roedores, a grande maioria utilizando ratos machos como sujeitos experimentais. No presente trabalho, foi analisada a influência da neurotransmissão 5-HT periférica e central sobre a expressão da resposta de medo condicionado e incondicionado de ratos machos e fêmeas, previamente selecionados pelo fenótipo como animais de baixa (BA) ou de alta (AA) reatividade emocional. Para este fim foi utilizado o teste do sobressalto potencializado pelo medo (SPM). A influência global e central de 5-HT foi avaliada pela utilização da administração sistêmica ou intraventricular aguda do inibidor irreversível da enzima triptofano hidroxilase PCPA (p-clorofenilalanina) nas doses de 200 mg/mL (i.p.) e 200 µg/5 µL (i.v.), ou através de infusões locais de 5-HT (10 nmol/0.2 µL) ou do agonista seletivo de receptores 5-HT1A 8-hidroxi-2-(di-n-propilamino)-tetralina (8-OH-DPAT) na dose de 0,3 µg/0.2 µL, diretamente em áreas encefálicas conhecidas por sua influência na modulação do medo e ansiedade a saber: o córtex pré-limbico (CPL), o núcleo basolateral da amígdala (BLA), e a substância cinzenta periaqueductal dorsal (SCPd) do mesencéfalo. As variáveis dependentes registradas foram a amplitude e a latência das respostas incondicionadas e condicionadas de sobressalto e a amplitude do SPM. / Extensive data in the literature have signaled the importance of serotonin (5-HT) on the modulation of fear and anxiety-like behaviors in rodents. In the present study, we have analyzed the influence of peripheral and central 5-HT neurotransmission on the expression of the conditioned and unconditioned fear, and on the fear-potentiated startle in male and female rats previously selected as low- (LA) or high-anxiety (HA). For this purpose, we used the fear-potentiated startle (FPS) test. The global and central influence of 5-HT was evaluated by using the acute systemic or intraventricular administration of the irreversible tryptophan hydroxylase inhibitor PCPA (p-chlorophenylalanine - 200 mg/mL i.p., or 200 µg/5 µL i.v.). Local effects were evaluated through local infusions of 5-HT itself (10 nmol/0.2 µL) or the selective 5-HT1A receptors agonist 8-hydroxy-2-(di-n-propylamino)-tetralin (8-OH-DPAT 0.3 µg/0.2 µL) in the prelimbic cortex (PrL), basolateral amygdala (BLA) or the dorsal periaqueductal gray (DPAG). These brain regions were chosen for the present study based on their great importance in the modulation and expression of conditioned and unconditioned fear. Dependent variables recorded were the amplitude and latency of unconditioned and conditioned fear, and fear-potentiated startle (FPS).
334

Experiences of Nonincarcerated African American Male Youth With an Incarcerated Male Sibling

Biney, Fred Nana 01 January 2016 (has links)
Approximately half of all incarcerated individuals in the United States are young African American men. Researchers have documented that nonincarcerated siblings may commit a crime when their sibling is in prison. The current study addressed literature regarding the experiences, and coping strategies of nonincarcerated young African American men who live in the inner city, and have a male sibling in prison. Guided by Bronfenbrenner's ecological systems theory, this interpretative phenomenological analysis (IPA) study explored the lived experiences and coping strategies of African American male youth with a brother in incarceration. Purposive sampling was used to select 3 nonincarcerated African American young men aged 18 to 24 years living in the inner city of a large city in southern Connecticut for in-depth interviews. Overall findings showed that while having an incarcerated sibling was a profoundly negative experience for study participants, and their families, the study participants also developed some positive coping strategies as a result of their experiences. These results could help policymakers, social workers, counselors, and criminal justice professionals understand the impacts of sibling incarceration, and learn how to deal more effectively with youth affected by it. .
335

Nunga rappin: talkin the talk, walkin the walk: Young Nunga males and Education

Rosas Blanch, Faye, faye.blanch@flinders.edu.au January 2009 (has links)
Abstract This thesis acknowledges the social and cultural importance of education and the role the institution plays in the construction of knowledge – in this case of young Nunga males. It also recognizes that education is a contested field. I have disrupted constructions of knowledge about young Nunga males in mainstream education by mapping and rapping - or mappin and rappin Aboriginal English - the theories of race, masculinity, performance, cultural capital, body and desire and space and place through the use of Nunga time-space pathways. Through disruption I have shown how the theories of race and masculinity underpin ways in which Blackness and Indignity are played out within the racialisation of education and how the process of racialisation informs young Nunga males’ experiences of schooling. The cultural capital that young Nunga males bring to the classroom and schooling environment must be acknowledged to enable performance of agency in contested time, space and knowledge paradigms. Agency privileges their understanding and desire for change and encourages them to apply strategies that contribute to their own journeys home through time-space pathways that are (at least in part) of their own choosing.
336

Serum Antibodies to Human Papillomavirus Type 6, 11, 16 and 18 and Their Role in the Natural History of HPV Infection in Men

Lu, Beibei 01 January 2010 (has links)
Our understanding of humoral immune response to human papillomavirus (HPV) infection has been mainly derived from studies in women. Very little is known about humoral immune response to HPV in men. There is also a growing interest in understanding the burden of HPV exposure in the subgroups of the male population, including men who have sex with women (MSW), men who have sex with men (MSM) and men who have sex with both men and women (MSMW). This dissertation was undertaken to understand and characterize humoral immune response, measured by detectable serum antibody IgG, to HPV 6, 11, 16 and 18 infection, to estimates seroprevalence of HPV 6, 11, 16 and 18, to determine the associations of sociodemographic and sexual behavioral factors with seroprevalence of individual HPV types, and to evaluate the role of serum antibodies in the subsequent acquisition of infection with the same HPV type, genetically related and un-related HPV types. Three studies that compose of this dissertation were conducted within the framework of two longitudinal studies of HPV infection in men: a single-site natural history study of male residents of Tucson, Arizona (the 1st study: N=285); and a multinational natural history study of healthy men residing in São Paulo, Brazil, Cuernavaca, Mexico, and Tampa, Florida (the 2nd study: N=1477; the 3rd study: N=2187). Men were recruited using similar eligibility criteria in both natural history studies and followed every 6 months for a maximum of 18 months in the single-site study and 48 months in the multi-national study. HPV DNA status was assessed using the PGMY09/11 L1 consensus primer system and the Linear Array HPV Genotyping Protocol. Testing of serum antibodies to HPV 6, 11, 16 and 18 was performed with virus-like particle-based ELISA assays. Data from our studies indicate that exposure to HPV 6, 11, 16 and 18, the four HPV types targeted in the currently license HPV vaccines, is common. Of 285 male residents of Tucson, Arizona, 28.8% of them were seropositive to HPV 16 and/or 18 at study entry. Similarly, approximately one third of 1477 participants of the multi-national male HPV natural history study were seropositive to at least one vaccine HPV type, with the percentage of 21.8% in U.S. site, 33.4% in Mexico site, and 49.1% in Brazil site. It is also noted that seroprevalence of individual vaccine HPV types is greatly elevated among men of different sexual practices. Seroprevalence of HPV 6, 11, 16 and/or 18 was twice as high among MSM and MSMW compared to MSW. Likewise, seroprevalence of individual HPV types was two fold or higher among MSW and MSMW. Our findings suggest that the predominant predictors of seropositivity to HPV 6, 11, 16 and 18 are age and same-sex sexual behaviors. Seroprevalence increased with age among young-to-middle-aged men with significant upward age trends observed for HPV 11, 16 and 18. MSM, compared to MSW, more likely to be seropositive to HPV 16 or 18. Similarly, men who practiced same-sex anal sex, compared to those who did not, were significantly more likely to be seropositive to HPV 6, 11, 16 and 18, respectively. Among 276 men free of HPV 16 at enrollment in Tucson, We did not detect statistically significant associations between the baseline serum antibodies to HPV 16 and/or 18 and subsequent risk of infection with homogeneous HPV types or related-HPV types. Of 2187 men residing in three countries who tested HPV 16 negative at enrollment, the risk of subsequent HPV 16 infection was not associated with enrollment HPV 16 serum antibodies status. Our data provide important estimates of population exposure to vaccine HPV types for future studies modeling potential vaccine impact and vaccine cost effectiveness in men. Our findings also support strategic vaccination of males as an effective preventive measure for HPV-related diseases and cancers in men and their sex partners, men and women alike.
337

Consuming and performing Black manhood : the Post Hip-Hop Generation and the consumption of popular media and cultural products / Post Hip-Hop Generation and the consumption of popular media and cultural products

Williams, Adam Clark 10 February 2012 (has links)
Thirty-three young Black men of the Post-Hip Hop Generation (ages 18-25) in Austin, TX, participated in a qualitative study centering on questions investigating Black manhood, media use, and the consumption of popular cultural products. Further, the researcher examined representations of Black men throughout music videos, films, and MySpace profiles. The purpose of this study was to enhance our knowledge about how Black manhood is being defined, conceptualized, and expressed by young Black men, and how significant media and cultural consumption plays a role in their lives. This study probes six questions: RQ1: How do young Black males interpret the images and messages about Black men from mainstream media? RQ2: What types of cultural products are being consumed by young Black men? Why do they consume them? RQ3: How do young Black males define Black manhood? RQ4: Do these cultural products influence the ways that young Black men define/express Black manhood? If so, how? Focus group sessions were conducted throughout the study, which were video recorded and transcribed. Transcriptions were then imported into a qualitative software program known as Atlas.ti, where statements related to the purpose of the study were coded and analyzed. These coded statements were then compared to observations made by the researcher from the examined media representations. / text
338

A Study of the Relationship between Key Influencers as Motivators to Attendance, Behavior, Engagement, and Academic Achievement among Middle School Students in Metropolitan Atlanta Georgia

Jackson, Ronnie 19 May 2014 (has links)
This study examines middle school students’ perceptions of the relationship between key influencers on student attendance, student behavior, student engagement, and academic achievement. Three hundred (300) survey participants were used in this mixed methods design, which consisted of an analysis of the independent variables affecting overall student motivation operationalized as Student Attendance, Student Behavior, Student Engagement, and Academic Achievement of eighth grade students. The survey participants were composed of two urban middle schools in a large public school system and a private middle school in the same county. African-American male students were isolated to analyze correlation relationships among variables. Findings of the study indicated that among other outcomes, African-American male students have definite perspectives about teacher quality and the impact of parental involvement.
339

Energia digestível para reprodutores de jundiá (Rhamdia quelen) / Digestible energy to silver catfish (Rhamdia quelen) broodstocks

Tessaro, Lucelia 15 February 2011 (has links)
Made available in DSpace on 2017-07-10T18:13:32Z (GMT). No. of bitstreams: 1 Lucelia Tessaro.pdf: 2574631 bytes, checksum: ca57438c0aba9b691b6d844030fa8eb8 (MD5) Previous issue date: 2011-02-15 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / It was studied the effect of the different digestible energy levels (DE) on reproductive and animal performance and gonads and livers histological aspects of silver catfish broodstocks (Rhamdia quelen). The treatments were digestible energy levels of 2.850, 3.100, 3.350, 3.600 e 3.850 kcal.kg feed, in diets containing 30% digestible protein (DP. The animals were stocked in tanks of 16m2 under conditions of light and temperature natural. The temperature water of the tanks was monitored daily. pH and oxygen dissolved were measured biweekly. The fish were feed during 210 days and were evaluated, initial and final, length, weight, weight gain and condition factor, separately to males and females. For the reproductive parameters, from October 2009 to February 2010 the males were induce, monthly, by carp pituitary extract (2,5mg.kg male) for collect milt samples. In the reproductive session, the females were induced by carp pituitary extract (5,5mg.kg female) for evaluation to number of spawn females (%) and absolute and relative fecundity. In the same period, six males and six females in each treatment were killed to obtained, visceral, gonad and hepatossomatic index, and to histological characterization of maturation stages and hepatic aspects. The water quality remained in the levels recommended for the species. Animal performances to males and females were not affected by feed. In relation to the hepatic aspects, were observed cytoplasmic vacuolation and steatosis in females. For the males this hepatic alteration were not observed. For the reproductive parameters, males and females were not influenced. The Monthly variations on seminal parameters were observed and indicated a reproductive pike in the spring. The feds containing 30% of digestible protein and energy levels from 2,850 to 3,850 kcal.kg were not affect reproductive parameters to males or females, however, females feed on 3,100 to 3,600kcal.kg showed cytoplasmic vacuolation in hepatocytes. / O estudo avaliou diferentes níveis de energia digestível (ED) sobre o desempenho zootécnico, reprodutivo e aspectos histológicos do tecido hepático e gonadal de machos e fêmeas de jundiá (Rhamdia quelen). As rações testadas foram isoproteicas contendo 30% proteína digestível (PD) e 2.850, 3.100, 3.350, 3.600 e 3.850 kcal de energia digestível (ED) (kcal.kg ração-1) Os peixes foram alojados em tanques escavados sob condições de fotoperíodo e temperatura natural. A água dos tanques foi monitorada diariamente quanto a temperatura e quinzenalmente quanto pH e oxigênio dissolvido. Os animais foram acompanhados durante 210 dias e foram avaliados, separadamente por sexo, ao início e ao término do experimento, quanto ao comprimento padrão, peso médio, ganho de peso e fator de condição, este último apenas para os machos. Para os parâmetros reprodutivos, entre os meses de outubro a fevereiro, os machos mensalmente foram submetidos às análises seminais e espermáticas. Para tanto, os machos foram submetidos ao protocolo de indução hormonal empregando extrato pituitário de carpa em dose única de 2,5 mg.kg-1. Dentro do período reprodutivo, as fêmeas foram induzidas hormonalmente com protocolo semelhante, contudo utilizando 5,5 mg.kg-1. Após a indução foram avaliados o percentual de fêmeas desovantes e as fecundidades absoluta e relativa. No mesmo período em que as fêmeas foram submetidas a reprodução artificial, foram selecionados aleatoriamente e abatidos seis machos e seis fêmeas de cada tratamento. Os reprodutores foram dissecados para mensuração dos índices víscerossomático, hepatossomático e gonadossomático, bem como para caracterização histológica do estágio de maturação gonadal e do tecido hepático. A qualidade da água permaneceu dentro dos níveis recomendados para a espécie. Não foi verificado efeito (p>0,05) das rações para os parâmetros zootécnicos seja para machos ou fêmeas. Quanto aos aspectos hepáticos, foi verificada a ocorrência de vacúolos citoplasmáticos e esteatose nas fêmeas. O mesmo não foi observado nos machos. Para os aspectos reprodutivos, machos e fêmeas não foram influenciados pelos níveis energéticos testados (p>0,05). Os machos apresentaram, ao longo dos meses, características seminais e espermáticas que sugerem a ocorrência de um pico reprodutivo no final da primavera. Rações contendo 30% de proteína digestível e níveis de energia entre 2.850 e 3.850 kcal.kg de ração-1 não afetam os parâmetros reprodutivos de machos e fêmeas de jundiá, contudo, em fêmeas, rações contendo entre 3.100 e 3.600 kcal causam vacuolização nos hepatócitos, possivelmente pela deposição lipídica.
340

A expressão do medo condicionado em ratos com fenótipos de baixa e alta reatividade emocional: modulação serotoninérgica cortical e subcortical sobre as diferenças de gênero / The conditioned fear expression in rats with low- or high-anxiety phenotype: cortical and subcortical 5-HT influence on gender differences

Renata Ferreira 08 August 2014 (has links)
Extensos dados na literatura têm assinalado a importância da serotonina (5-HT) na modulação de comportamentos de medo e ansiedade em roedores, a grande maioria utilizando ratos machos como sujeitos experimentais. No presente trabalho, foi analisada a influência da neurotransmissão 5-HT periférica e central sobre a expressão da resposta de medo condicionado e incondicionado de ratos machos e fêmeas, previamente selecionados pelo fenótipo como animais de baixa (BA) ou de alta (AA) reatividade emocional. Para este fim foi utilizado o teste do sobressalto potencializado pelo medo (SPM). A influência global e central de 5-HT foi avaliada pela utilização da administração sistêmica ou intraventricular aguda do inibidor irreversível da enzima triptofano hidroxilase PCPA (p-clorofenilalanina) nas doses de 200 mg/mL (i.p.) e 200 µg/5 µL (i.v.), ou através de infusões locais de 5-HT (10 nmol/0.2 µL) ou do agonista seletivo de receptores 5-HT1A 8-hidroxi-2-(di-n-propilamino)-tetralina (8-OH-DPAT) na dose de 0,3 µg/0.2 µL, diretamente em áreas encefálicas conhecidas por sua influência na modulação do medo e ansiedade a saber: o córtex pré-limbico (CPL), o núcleo basolateral da amígdala (BLA), e a substância cinzenta periaqueductal dorsal (SCPd) do mesencéfalo. As variáveis dependentes registradas foram a amplitude e a latência das respostas incondicionadas e condicionadas de sobressalto e a amplitude do SPM. / Extensive data in the literature have signaled the importance of serotonin (5-HT) on the modulation of fear and anxiety-like behaviors in rodents. In the present study, we have analyzed the influence of peripheral and central 5-HT neurotransmission on the expression of the conditioned and unconditioned fear, and on the fear-potentiated startle in male and female rats previously selected as low- (LA) or high-anxiety (HA). For this purpose, we used the fear-potentiated startle (FPS) test. The global and central influence of 5-HT was evaluated by using the acute systemic or intraventricular administration of the irreversible tryptophan hydroxylase inhibitor PCPA (p-chlorophenylalanine - 200 mg/mL i.p., or 200 µg/5 µL i.v.). Local effects were evaluated through local infusions of 5-HT itself (10 nmol/0.2 µL) or the selective 5-HT1A receptors agonist 8-hydroxy-2-(di-n-propylamino)-tetralin (8-OH-DPAT 0.3 µg/0.2 µL) in the prelimbic cortex (PrL), basolateral amygdala (BLA) or the dorsal periaqueductal gray (DPAG). These brain regions were chosen for the present study based on their great importance in the modulation and expression of conditioned and unconditioned fear. Dependent variables recorded were the amplitude and latency of unconditioned and conditioned fear, and fear-potentiated startle (FPS).

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