La actividad cerebral exhibe complejos fenómenos oscilatorios similares a los que se observan en modelos de redes artificiales con osciladores acoplados. Por un lado, estudios sobre la actividad cerebral durante el reposo han demostrado la presencia de fluctuaciones lentas estructuradas y modulaciones de potencia a distintas frecuencias. Simultáneamente, estudios teóricos en el ámbito de la física muestran dinámicas similares usando osciladores acoplados. En este trabajo, por primera vez, se usan modelos de osciladores de fase en redes inspiradas en la arquitectura real del cerebro. Los resultados muestran la aparición espontánea de una dinámica similar a la observada experimentalmente. Además, esta correspondencia es comparable cuantitativamente con datos de neuroimagen, lo que sugiere procesos generales de integración subyacentes a la cognición. Por otra parte, se propone que la actividad cerebral alterada observada en algunas enfermedades psiquiátricas podría tener su origen en desconexiones estructurales que afectarían el comportamiento cooperativo de regiones corticales. / Neural activity in the brain exhibits complex oscillatory phenomena that can be compared with the ones observed in artificial network models of coupled oscillators. In particular, neuroimaging studies of brain activity during rest have reported slow spatiotemporally organized fluctuations and correlated band-limited power modulations. Simultaneously, theoretical works on the area of physics have reported similar dynamic behaviours using simple models of coupled oscillators with intermittent modular synchronization. In this work, for the first time, we use models of phase oscillators in networks inspired in the brain’s wiring architecture. Results show the spontaneous emergence of a dynamics similar to the one observed experimentally. In addition, this correspondence is quantitatively comparable to neuroimaging data, which is suggestive of general integrative processes underlying cognition. Furthermore, we propose that altered brain activity observed in some psychiatric diseases might originate from structural disconnections, which affect the cooperative behaviour of coupled cortical regions.

Made available in DSpace on 2014-06-11T19:23:35Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-06-19Bitstream added on 2014-06-13T19:09:27Z : No. of bitstreams: 1 souza_cl_me_arafcf.pdf: 612007 bytes, checksum: 205b15eafb3b20ed92b7460fb74d2b3c (MD5) / Universidade Estadual Paulista (UNESP) / Unimep / A obesidade é uma doença estreitamente relacionada ao desenvolvimento da síndrome metabólica (SM) e é fundamentalmente um problema de balanço energético que se desenvolve quando a ingestão de energia proveniente dos alimentos é maior que o gasto energético total. O gasto energético total compreende a taxa metabólica de repouso, o efeito térmico dos alimentos e os gastos com atividade física e pode ser medido pela calorimetria indireta. O objetivo deste trabalho foi estudar a relação da taxa metabólica de repouso (TMR) em mulheres obesas com os componentes da SM e fatores relacionados. O grupo de estudo foi constituído por 35 mulheres com idade entre 18 e 40 anos, que apresentavam um índice de massa corporal (IMC) maior ou igual a 30 kg/m². Foram excluídas as mulheres portadoras de diabetes mellitus, hipotireoidismo, gestantes, lactantes e aquelas em tratamento (medicamentoso ou não) para obesidade e dislipidemias, além das portadoras de doenças graves. Foram aplicados um questionário para obtenção de dados sócio-demográficos, três recordatórios de 24 horas em dias não consecutivos sendo um final de semana e três diários de atividade física, aplicados no mesmo dia dos recordatórios. O comportamento alimentar foi avaliado pela escala de compulsão alimentar periódica (ECAP). Dentre as variáveis antropométricas foram avaliadas peso, estatura, circunferência de cintura, quadril e braço. A composição corporal (percentual de gordura e massa magra) foi avaliada pela bioimpedância elétrica e a TMR foi avaliada por meio do analisador de gases VO2000 MedGraphicsÒ. Foram ainda dosados em sangue o colesterol total e frações, glicose, insulina, proteína C reativa e triglicérides. As mulheres foram agrupadas quanto à presença ou não de SM e em tercil de TMR ajustada para a massa corporal (TMR/MC)... / It is known that obesity, a disease closely related to the development of the metabolic syndrome (MS), is basically a problem of energy balance and develops when energy intake exceeds total energy expenditure. Total energetic expenditure includes basal metabolic rate, the thermogenic effect of food and expenditures with physical activity and can be determined by indirect calorimetry. The objective of this study was to relate the basal metabolic rate (BMR) of obese women with MS components and related factors. The studied group included 35 women aged 18 to 40 years with a body mass index equal to or above 30 kg/m². Women with diabetes mellitus, hypothyroidism, severe diseases, women being treated for obesity and dyslipidemias and pregnant and lactating women were excluded from this study. A questionnaire to obtain sociodemographic data, three 24-hour dietary recalls in non-consecutive days one being during the weekend and three physical activity diaries administered on the same day as the 24-hour recalls were administered. Eating behavior was assessed by the binge eating scale (BES). The following anthropometric variables were assessed: weight, height and waist, hip and arm circumferences. Body composition (percentage of fat and lean mass) was determined by electrical bioimpedance and the basal metabolic rate was assessed by the gas exchange testing system MedGraphics VO2000®. The women were divided into groups with and without the MS and in BMR terciles adjusted for body mass (BMR/BM). The results showed that there was no significantly statistical difference between the groups with and without the MS regarding income, physical activity, presence of binge eating disorder, dietary macronutrient and micronutrient composition, energy intake, BMR, respiratory quotient (RQ), BMR/BM or MBR/LM. When the women were divided into BMR/BM terciles, BMR/BM was not associated with MS components... (Complete abstract click electronic access below)

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Around the world Alzheimer’s Disease (AD) is on the rise. Previous studies have shown the default mode network (DMN) sees changes with AD progression as the disease erodes away cortical areas. Aerobic exercise with significant increases to cardiorespiratory fitness could show neuro-protective changes to delay AD. This study will explore if functional connectivity changes in the DMN can be seen in a young adult sample by using group independent component analysis through FSL MELODIC. The young adult sample of 19 were selected from a larger study at the Brain Plasticity and Neuroimaging Laboratory at Boston University. The participants engaged in a twelve-week exercise intervention in either a strength training or aerobic training group. They also completed pre-intervention and post-intervention resting-state fMRI scans to evaluate change in functional connectivity in the default mode network. Cardiorespiratory fitness was assessed using a modified Balke protocol with pre-intervention and post-intervention VO2 max percentiles being used. Through two repeated-measure ANOVA analyses, this study found no significant increase in mean functional connectivity or cardiorespiratory fitness in the young adult sample. While improvements in mean VO2 max percentile and functional connectivity would have been seen with a larger sample size, this study adds to the literature by suggesting if fitness does not improve significantly, neither will functional connectivity in the default mode network.

Mole-rats are placental mammals which are perfectly adapted to subterranean life. In this thesis I present novel findings on working metabolism and thermoregulatory physiology of mole-rats. These animals cope with low availability of food and have thus employed multiple strategies how to conserve energy and/or use it more effectively. Among other adaptations this resulted in lower resting body temperature, tolerance to increase in body temperature during exercise or while at rest, surprisingly efficient cooling while digging and precise diurnal and seasonal timing of activity with regards to environmental conditions. My focus in this work is on the digging metabolic rate and thermoregulation of social Fukomys mechowii and solitary Heliophobius argenteocinereus in soft and hard substrate, thermoregulatory abilities of Fukomys darlingi, seasonal changes of activity in free living Heliophobius argenteocinereus measured as daily energy expenditure and, finally, energetic consequences of the daily activity patterns of Fukomys anselli.

This thesis was focused on determining the orientation of the body of domestic sheep while grazing or resting. Attention was also paid to the assessment of environmental conditions that may affect the position of animal behaviour. Data were collected through the direct observation compared to the previous studies, which have been based on satellite images from Google Earth. In this experiment, only selected designated individuals were evaluated. The direct observation detected the individual preferences of animals, not only the direction but also the location. The evaluating of photos of the animals found out, according to the time of day,north and west facing position of the body. The more significant directional preference was documented in resting individuals.

The current study explored how hot and cool executive functions (EF) could predict resting-state connectivity of the Default Mode Network (DMN) and Central Executive Network (CEN) in a mixed clinical and typically developing sample of adolescents. It was hypothesized that hot EF would predict a quadratic, inverted U-shaped, relationship between connectivity of the major regions of the DMN: the Posterior Cingulate Cortex (PCC) and the Medial Prefrontal Cortex (MPFC). It also was hypothesized that cool EF would predict a quadratic, inverted U-shaped, relationship between the connectivity of the major regions of the CEN: the right Posterior Parietal Cortex (right PPC) and the right Dorsal Lateral Prefrontal Cortex (right DLPFC). The results suggested that hot EF, specifically emotional regulation, predicted a quadratic relationship in DMN connectivity. However, this relationship was U-shaped instead of an inverted U-shaped. Thus, participants who scored well or poorly in emotional regulation generally had higher connectivity than those with average scores in emotional regulation. There were no significant results between cool EF and the CEN. Additional exploratory analysis suggested that the main hypotheses were not driven or suppressed by group differences. Further exploration observed other brain regions involved in resting-state activity that may play a role in hot or cool EF. Overall, findings support the Internal Mentation Hypothesis of DMN activity and are indicative of a relationship between emotional regulation and DMN resting-state connectivity.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Assim como na população geral, as necessidades energéticas diárias dos pacientes em tratamento crônico de hemodiálise (HD) podem ser calculadas multiplicando-se o gasto energético de repouso (GER) pelo nível de atividade física. Até o momento, não há estudos que avaliaram se as equações de predição são precisas para se estimar o GER de idosos em HD. O objetivo do presente estudo foi avaliar a concordância entre o GER obtido pela calorimetria indireta e as equações de predição de Harris&Benedict, Schofield e a proposta pelo documento da Organização Mundial de Saúde de 1985 (FAO 1985) nos pacientes idosos em HD. Tratou-se de um estudo transversal, onde foi avaliado o GER de 57 pacientes idosos não institucionalizados (> 60anos) em tratamento crônico de HD mensurado pela calorimetria indireta e comparado com as equações de predição de Harris&Benedict, Schofield e FAO 1985.A concordância entre o GER medido e as equações foi realizada pelo coeficiente de correlação intraclasse e pela análise de Bland-Altman. Neste estudo pode-se observar que o GER estimado pelas 3 equações foi significantemente maior do que o obtido pela calorimetria indireta. Um grau de reprodutibilidade moderado foi observado entre a calorimetria indireta e as equações. A superestimação foi o principal erro observado, sendo presente na metade dos pacientes. A subestimação foi vista em aproximadamente em 10 % dos pacientes. Com base nesses achados podemos concluir que as 3 equações tiveram uma performance similar ao estimar o GER. E estas podem ser utilizadas para calcular o GER de idosos em HD, na medida em que os nutricionistas reconheçam seus possíveis erros, principalmente quando as equações de predição subestimam o GER medido. / Objectives: The daily energy requirements of hemodialysis (HD) patients can be calculated by multiplying the resting energy expenditure (REE) by the physical activity level. Up to now, there are no studies assessing whether prediction equations are accurate to assess the REE in elderly HD. We aimed to evaluate the agreement between the REE obtained by indirect calorimetry and the prediction equations of Harris&Benedict, Schofield and World Health Organization 1985 (WHO 1985) in elderly patients on hemodialysis (HD). Design, setting and participants: This is a cross-sectional study. The REE of 57 elderly non-institutionalized patients (> 60 years) on HD was measured by indirect calorimetry and compared with the prediction equations of Harris&Benedict, Schofield and WHO 1985. The agreement between the REE and the equations were assessed by the intraclass correlation coefficient and by the Bland-Altman plot analysis. Results: The REE estimated by the 3 equations were significantly higher than that obtained by the indirect calorimetry. A moderate degree of reproducibility was observed between the indirect calorimetry and the equations. Overestimation was the main error observed, being present in half of the patients. Underestimation was seen in approximately 10% of the patients. Conclusion: These 3 equations performed similarly when estimating the REE. They can be used to calculate the REE in elderly HD, but clinicians should be aware of possible errors, mainly when prediction equations underestimate the measured REE.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Assim como na população geral, as necessidades energéticas diárias dos pacientes em tratamento crônico de hemodiálise (HD) podem ser calculadas multiplicando-se o gasto energético de repouso (GER) pelo nível de atividade física. Até o momento, não há estudos que avaliaram se as equações de predição são precisas para se estimar o GER de idosos em HD. O objetivo do presente estudo foi avaliar a concordância entre o GER obtido pela calorimetria indireta e as equações de predição de Harris&Benedict, Schofield e a proposta pelo documento da Organização Mundial de Saúde de 1985 (FAO 1985) nos pacientes idosos em HD. Tratou-se de um estudo transversal, onde foi avaliado o GER de 57 pacientes idosos não institucionalizados (> 60anos) em tratamento crônico de HD mensurado pela calorimetria indireta e comparado com as equações de predição de Harris&Benedict, Schofield e FAO 1985.A concordância entre o GER medido e as equações foi realizada pelo coeficiente de correlação intraclasse e pela análise de Bland-Altman. Neste estudo pode-se observar que o GER estimado pelas 3 equações foi significantemente maior do que o obtido pela calorimetria indireta. Um grau de reprodutibilidade moderado foi observado entre a calorimetria indireta e as equações. A superestimação foi o principal erro observado, sendo presente na metade dos pacientes. A subestimação foi vista em aproximadamente em 10 % dos pacientes. Com base nesses achados podemos concluir que as 3 equações tiveram uma performance similar ao estimar o GER. E estas podem ser utilizadas para calcular o GER de idosos em HD, na medida em que os nutricionistas reconheçam seus possíveis erros, principalmente quando as equações de predição subestimam o GER medido. / Objectives: The daily energy requirements of hemodialysis (HD) patients can be calculated by multiplying the resting energy expenditure (REE) by the physical activity level. Up to now, there are no studies assessing whether prediction equations are accurate to assess the REE in elderly HD. We aimed to evaluate the agreement between the REE obtained by indirect calorimetry and the prediction equations of Harris&Benedict, Schofield and World Health Organization 1985 (WHO 1985) in elderly patients on hemodialysis (HD). Design, setting and participants: This is a cross-sectional study. The REE of 57 elderly non-institutionalized patients (> 60 years) on HD was measured by indirect calorimetry and compared with the prediction equations of Harris&Benedict, Schofield and WHO 1985. The agreement between the REE and the equations were assessed by the intraclass correlation coefficient and by the Bland-Altman plot analysis. Results: The REE estimated by the 3 equations were significantly higher than that obtained by the indirect calorimetry. A moderate degree of reproducibility was observed between the indirect calorimetry and the equations. Overestimation was the main error observed, being present in half of the patients. Underestimation was seen in approximately 10% of the patients. Conclusion: These 3 equations performed similarly when estimating the REE. They can be used to calculate the REE in elderly HD, but clinicians should be aware of possible errors, mainly when prediction equations underestimate the measured REE.

Elevadas concentrações de tirglicerídeos (TAG) no período pós-prandial são associados com o desenvolvimento de doenças cardiovasculares (DCV), bem como são responsáveis por mais de 23% da mortalidade em mulheres na menopausa. O treinamento de força (TF) é uma intervenção não farmacológica impregada na prevenção e redução dos múltiplos fatores de risco para o desenvolvimento de DCV. O exercício de força realizado em alto volume vem sendo apresentado como estratégia efetiva na redução da lipemia pós-prandial (LPP) em jovens. No entanto, a comparação entre alto e baixo volume do TF não havia sido investigado. Por esse motivo, o objetivo deste estudo foi comparar a resposta aguda e de 11 semanas de TF realizado em baixo e alto volume na força dinâmica máxima, espessura muscular, gasto energético e perfil lipidico de mulheres pós-menopáusicas. Trinta e nove mulheres pós-menopausicas saudáveis e destreinadas (59,5±4,8 anos de idade, massa corporal 69,6±9,1 kg, estatura 157,9±7,2 cm; IMC 27,6±4,1 kg•m2; circunferência da cintura 76,1±9,7 cm; VO2pico 18,7±1,4 mL•kg•min) foram aleatóriamente distribuídas em três grupos que realizaram a sessão de exercícios de força em: baixo volume (uma série) (BVEF, n=12), alto volume (AVEF, n=14) e um grupo controle (GC, n = 13) que permaneceu em repouso. Os grupos experimentais (BVEF e AVEF) foram submetidos a uma sessão de exercícios de força (SEF), envolvendo oito exercícios. O grupo BVEF realizou uma série de 15 repetições máximas (RM), e o grupo AVEF realizou três séries de 15RM. Na SEF foram avaliados o gasto energético da sessão e o EPOC (excess post-exercise oxygen consumption). No teste de tolerancia oral a gordura (TTOG), ~16 horas após a SEF, todos os grupos receberam um refeição hiperlipidica a base de leite seguido por uma avaliação do perfil lipídico (colesterol total (CT), glicose (GLU), HDL, LDL e TAG) nos períodos basal, 1, 2, 3, 4 e 5 horas após o TTOG. Resultados: Não houve diferença significativa entre os grupos no perfil lipidico em nenhum dos períodos avaliados. O gasto energético total (SEF+EPOC) foi significativamente maior para AVEF em comparação ao BVEF (6,0±0,12 MJ e 3,1±1,1 MJ, respectivamente, p<0,001). No estudo com treinamento, foram avaliadas trinta e seis mulheres pós-menopáusicas com uma perda amostral de três mulheres, sendo estas submetidas a 11 semanas de TF. Os grupos AVEF e BVTF foram divididos em alto volume de treinamento de força (AVTF=13) e baixo volume de treinamento de força (BVTF=12), o GC (n=11) foi preservado. Neste estudo, todas as variáveis foram avaliadas pré e pós treinamento. Como resultados; nenhuma diferença significativa foi observada entre os grupos na LPP (mmol/L/5hs) para GLU, HDL, LDL e CT. Além disso, o AVTF vs BVTF foi significativamente maior após 11 semanas de TF nas variáveis taxa de oxidação de gordura (5,52±1,69 g/h vs 4,11±1,12 g/h), espessura muscular (VM, 21,4 ± 1,8 mm vs 18,4±1,2 mm e VL (22,3±1,2 mm vs 20,8±1,3 mm). Os pontos 0, 1, 2, 4 e 5 horas após TTOG para TAG e AUC de TAG (5,79±0,42 mmol/L/5hs vs 7,78±0,68 mmol/L/5hs), respectivamente, foram significativamente menores no grupo AVTF (p<0,05). Em conclusão, diferentes volumes de uma única sessão de exercícios de força não são capazes de reduzir a lipemia pós-prandial de mulheres pósmenopáusicas após teste de tolerância a gordura. Entretanto, os resultados desta investigação sugerem que a prescrição do alto volume de treinamento de força reduz a lipemia pós-prandial em mulheres pós-menopáusicas. / Elevated concentrations of triglycerides (TAG) in the postprandial period are associated with the development of cardiovascular disease (CVD) and are responsible for over 23 % mortality in postmenopausal women. Resistance training (RT) is a non-pharmacological strategy to reduce multiple risk factors for developing CVD. The RT performed at high volume has been shown to be effective for the reduction of postprandial lipemia (PPL) in young people. However, the RT regular and systematic comparing high and low volume training had not been investigated. Therefore, the aim of this study was to compare the response subacute and 11 weeks of RT in low volume and high in strength, muscle thickness, energy expenditure and lipid profile of postmenopausal women. In article acute, thirty-nine postmenopausal women and healthy untrained (59.5±4.8 years, body mass 69.6±9.1 kg, height 157.9±7.2 cm, BMI 27,6±4.1 kg•m-2, waist circumference 76.1±9.7 cm; VO2peak 18.7±1.4 mL•kg-1•min-1) were randomly divided into three groups: group that conducted the exercise session strength at low volume (one set) ( LVSE, n=12), high volume (HVSE, n=14) and a control group (CG, n=13) who did not perform any exercise session. The experimental groups (LVSE and HVSE) held a session of strength exercises (SSE), involving eight exercises. In LVSE held a series of 15 repetitions maximum (RM), and the HVSE group performed three sets of 15RM, SSE were evaluated in the energy expenditure of the session and the EPOC (excess post -exercise oxygen consumption). In the test of oral fat tolerance (OGTT), ~16 hours of the SSE, all groups were given a high-fat meal and the milk, were evaluate; lipid profile (total cholesterol (TC), glucose (GLU), HDL, LDL and TAG) in times baseline, 1, 2, 3, 4 and 5 hours after an OGTT. Results: No significant difference between groups in lipid profile in any of the periods. Total energy expenditure (SSE+EPOC) was significantly higher compared to HVSE vs LVSE (6.0±0.12 MJ and 3.1±1.1 MJ, respectively, p<0.001). In the third study was evaluated thirty-six postmenopausal women, with a sample loss of three women who underwent 11 weeks of ST, and HVSE and LVSE groups were divided into high-volume strength training (HVST=13) and low volume strength training (LVST=12), GC (n=11) was preserved. In this study, all variables were assessed before and after 11 weeks os ST. Results: no significant difference was observed among groups in LPP (mmol/L/5 hours) to GLU, HDL, LDL and TC, also the HVSE versus LVSE was significantly greater after 11 weeks of ST for variables; rate fat oxidation, 5.52±1.69 g/h vs. 4.11±1.12g/h), muscle thickness (VM 21.4±1.2 mm versus 18.4±1.8 mm and VL, 22.3±1.2 mm versus 20.8±1.3 mm). In points 0, 1, 2, 4 and 5 hours after OGTT for TAG and TAG AUC (5.79±0.42 versus 7.78±0.68), respectively, were significantly lower in group AVTF (p<0.05). In conclusion, different volumes of a session of strength exercises do not reduce the subacutely postprandial lipemia in postmenopausal women after oral fat tolerance test. The results of this investigation suggest that the prescription of high volume strength training reduces postprandial lipemia in postmenopausal women.