ABSTRACT
Physiologically based stress detection systems have proven to be effective in identifying different stress conditions in the body to determine the source of stress and be able to counteract it. However, some stress conditions have not been widely studied, including thermal stress, cognitive stress, and combined (thermal-cognitive) stress conditions, which are frequently encountered in work or school environments. In order to develop systems to detect and differentiate these conditions, it is necessary to identify the physiological indicators that characterize each of them. The present research aims to identify which physiological indicators (heart rate, respiratory rate, galvanic skin response, and local temperature) could differentiate different stress conditions (no-stress, cognitive stress, thermal stress, and combined (thermal-cognitive) stress conditions). Thirty participants were exposed to cognitive, thermal, and combined stress sources while recording their physiological signals. The findings indicate that both mean heart rate and mean galvanic skin response identify moderate thermal and cognitive stress conditions as distinct from a no-stress condition, yet they do not differentiate between the two stress conditions. Additionally, heart rate uniquely identifies the cognitive-thermal stress condition, effectively distinguishing this combined stress condition from the singular stress conditions and the no-stress condition. Mean local temperature specifically signals thermal stress conditions, whereas mean respiratory rate accurately identifies cognitive stress conditions, with both indicators effectively separating these conditions from each other and from the no-stress condition. This is the first basis for differentiating thermal and cognitive stress conditions through physiological indicators.
Subject(s)
Galvanic Skin Response , Heart Rate , Respiratory Rate , Stress, Psychological , Humans , Heart Rate/physiology , Galvanic Skin Response/physiology , Male , Female , Stress, Psychological/physiopathology , Respiratory Rate/physiology , Young Adult , Adult , Cognition/physiology , Stress, Physiological/physiology , Body Temperature/physiologyABSTRACT
Introducción: a pesar del empleo de indicadores fisiológicos, psicofisiológicos y psicológicos asociados al estrés académico, la comunidad científica no ha logrado definir con total claridad qué comportamiento debe seguir. Objetivo: analizar el comportamiento de indicadores relacionados con el estrés académico en estudiantes universitarios. Materiales y métodos: están referidos a la aplicación de un procedimiento que consta de tres etapas: preparatoria, experimental y resultados. Se evaluaron los indicadores variabilidad de la frecuencia cardiaca, umbral de discriminación táctil, percepción de profundidad, tiempo de reacción simple y Prueba de Yoshitake. Como herramienta para el procesamiento de la información se utilizó el software Statgraphic Centurion 15.0. Resultados: existen diferencias significativas entre el antes y el después para la muestra examinada, además de diferencias entre las variaciones obtenidas de los indicadores entre los grupos. Se detectaron discrepancias entre los resultados obtenidos en el indicador tiempo de reacción simple, en presencia de estrés académico, y los obtenidos por otros investigadores. Conclusiones: fue demostrada la presencia de diferencias significativas en el comportamiento de los indicadores seleccionados ante la presencia de estrés académico en estudiantes universitarios, al menos bajo condiciones experimentales.
Introduction: in spite of the use of physiological, psycho-physiological and psychological indicators associated to academic stress, the scientific community has not been able to totally clear define what behavior should be followed. Objective: to analyze the behavior of indicators related to academic stress in university students. Materials and methods: they refer to the application of a procedure consisting in three stages: preparatory, experimental and results. The indicators heart frequency variability, tactile discrimination threshold, depth perception, simple reaction time and Yoshitake test were evaluated. The Statgraphic Centurion 15.0 software was used as a tool for information processing. Results: there are significant differences between before and after for the examined sample, in addition to differences between the variations obtained from indicators between the groups. Discrepancies were detected between the results obtained in the indicator simple reaction time, in the presence of academic stress, and those obtained by other researchers. Conclusions: the existence of significant differences in the behavior of chosen indicators in the presence of academic stress in university students was demonstrated, at least under experimental conditions.
ABSTRACT
This study aimed to determine the effects of dietary digestible protein (DP) on growth and physiological indicators in piapara. Three hundred piapara juveniles (24.0 ± 1.3 g) were distributed in 20 tanks of 130 L (15 fish/tank) with continuous aeration and water. Five isoenergetic diets (14.0 MJ·kg-1) were formulated to contain increasing levels of DP (21, 24, 27, 30 and 33%). After 77 days of feeding, increasing levels of digestible protein influenced final weight, specific growth rate and weight gain linearly (p < 0.05). Water ammonia concentration and liver alanine aminotransferase activity also showed a linear effect with an increasing DP level (p < 0.05), but no relationship was found between DP level and serum ammonia (p > 0.05). There was no linear and quadratic effect for hepatosomatic index, liver glycogen and liver lipid content (p > 0.05). On the other hand, the muscle lipid content decreased linearly with the increase in the DP level (p < 0.05), while the mesenteric fat index showed a linear and quadratic effect (p < 0.05) with an increasing curve until the peak of 25.77% DP. The activity of the hepatic malic enzyme also followed a quadratic pattern (p < 0.05) with a maximum point of 27.08% of DP. This contrasts with the hepatic enzyme glucose-6-phosphate dehydrogenase, which increased linearly with the increase in the DP level (p < 0.05). The results showed better productive performance for fish fed with the highest levels of DP, though greater excretion of ammonia in the water was also shown. Diets below 27% DP resulted in greater energy reserve, amino acid catabolism and lipogenesis. Therefore, the inclusion of 28 to 30% DP in the diet will be ideal for growth and physiological responses in piapara.(AU)
Este estudo teve como objetivo determinar os efeitos da proteína digestível (PD) da dieta sobre o crescimento e indicadores fisiológicos em piapara. Trezentos juvenis de piapara (24 ± 1,3 g) foram distribuídos em 20 tanques de 130 L (15 peixes/tanque) com aeração contínua e água. Cinco dietas isoenergéticas (14,0 MJ·kg-1) foram formuladas para conter níveis crescentes de PD (21, 24, 27, 30 e 33%). Após 77 dias de alimentação, níveis crescentes de proteína digestível influenciaram o peso final, taxa de crescimento específico e ganho de peso de forma linear (p<0,05). A concentração de amônia na água e a atividade hepática da alanina aminotransferase também apresentaram efeito linear com o aumento do nível de PD (p < 0,05), mas não foi encontrada relação entre o nível de PD e amônia sérica (p > 0,05). Não houve efeito linear nem quadrático no índice hepatossomático, no glicogênio hepático e na concentração de lipídios hepáticos (p > 0,05). Por outro lado, o conteúdo de lipídio muscular diminuiu de forma linear com o aumento do nível de PD (p < 0,05), enquanto o índice de gordura mesentérica apresentou efeito linear e quadrático (p < 0,05) com curva crescente até o ponto máximo em 25,77% de PD. A atividade hepática da enzima málica também seguiu um padrão quadrático (p < 0,05) com ponto máximo em 27,08% de PD, diferentemente da enzima glicose-6-fosfato desidrogenase hepática, que aumentou linearmente com o aumento do nível de PD (p < 0,05). Os resultados mostraram melhor desempenho produtivo para os peixes alimentados com os maiores níveis de PD. Por outro lado, também proporcionaram maior excreção de amônia na água. Dietas abaixo de 27% PD resultaram em maior reserva energética, catabolismo de aminoácidos e lipogênese. Portanto, a inclusão de 28 a 30% PD na dieta será ideal para o crescimento e respostas fisiológicas em piaparas.(AU)
Subject(s)
Animals , Proteins/physiology , Digestive System Physiological Phenomena , Characiformes/metabolism , Weight Gain/physiology , Alanine Transaminase/adverse effects , Eating/physiologyABSTRACT
Dissolved oxygen (DO) and water temperature vary in coastal environments. In tropical regions, the ability of aquatic ectotherms to cope with hypoxia and high-temperature interactive effects is fundamental for their survival. The mechanisms underlying both hypoxia and thermal tolerance are known to be interconnected, therefore, the idea of cross-tolerance between both environmental stressors has been put forward. We investigated the combined role of hypoxia and temperature changes on the physiological responses of blue crab Callinectes sapidus living in the southern Gulf of Mexico. We measured oxygen consumption, plasmatic biochemical indicators, total hemocyte count (THC), and antioxidant activity biomarkers in muscle and gill tissues of blue crab acclimated to moderate hypoxia or normoxia and exposed to a thermal fluctuation or a constant temperature, the former including a temperature beyond the optimum range. Animals recovered their routine metabolic rate (RMR) after experiencing thermal stress in normoxia, reflecting physiological plasticity to temperature changes. In hypoxia, the effect of increasing temperature was modulated as reflected in the RMR and plasmatic biochemical indicators concentration, and the THC did not suggest significant alterations in the health status. In both DO, the antioxidant defense system was active against oxidative (OX) damage to lipids and proteins. However, hypoxia was associated with an increase in the amelioration of OX damage. These results show that C. sapidus can modulate its thermal response in a stringent dependency with DO, supporting the idea of local acclimatization to tropical conditions, and providing insights into its potential as invasive species.
ABSTRACT
The aim of this study was to apply a protocol based on the Animal Welfare Indicators (AWIN) protocols for small ruminants in Brazilian Northeast farms to evaluate the welfare of meat goat, comparing animals kept on semi-intensive (S) and extensive (E) farms. Fifteen farms located in the Metropolitan Region of Quixadá and Quixeramobim, Ceará, Brazilian Northeast, were recruited. Assessments were performed at group and individual level. Significant differences between S and E farms was set at P 0.05 to all tests. At group level, there was a significant difference between groups, with more goats from E farms affected by heat stress and more animals from S farms presenting oblivion. Resource-based indicators, type of drinkers and access to shelter, differed significantly between S and E systems, with goats on S farms allocated in places with access to water more frequently during night period and protected from wind. Type of facility was more complex for animals on S farms (n=2) than on all E farms due to internal divisions, with S farms presenting feeders, drinking fountains, salt shakers, and slatted or cemented floor. At individual level, abscess and ocular discharge were more frequently observed on S farms and ears lesions were more frequent on E farms, probably due to distinct management of goats. Similarities between results showed that farmers in both production systems faced problems related to heat stress, lack of forage and health issues.(AU)
O objetivo deste estudo foi aplicar um protocolo baseado nos protocolos Animal Welfare Indicators (AWIN) de pequenos ruminantes em fazendas do nordeste brasileiro para avaliar o bem-estar de cabras de corte, comparando animais mantidos em fazendas semi-intensivas (S) e extensivas (E). Quinze fazendas localizadas na Região Metropolitana de Quixadá e Quixeramobim, no Ceará, Nordeste do Brasil, foram recrutadas. As avaliações foram realizadas no nível de grupo e individual. A diferença significativa entre as fazendas S e E foi estabelecida em P 0,05 para todos os testes. No nível de grupo, houve diferença significativa, com mais cabras do grupo E afetadas por estresse térmico e do grupo S apresentando apatia. Indicadores baseados em recursos, tipo de bebedores e acesso a abrigos diferiram significativamente entre os sistemas S e E, com cabras em fazendas S alocadas em locais com acesso à água durante o período noturno mais frequentemente e protegidas do vento. O tipo de instalação era mais complexo para os animais nas fazendas S (n=2) do que nas fazendas E, devido as divisões internas, com a presença de comedouros, bebedouros, saleiros, piso ripado ou cimentado em fazendas S. A nível individual, abscesso e secreção ocular foram observados mais frequentemente nas fazendas S, e lesões nas orelhas, nas fazendas E, provavelmente devido ao manejo distinto das cabras. Semelhanças entre os resultados mostraram que os fazendeiros de ambos os sistemas de produção enfrentam problemas relacionados ao estresse térmico, falta de forragem e problemas de saúde.(AU)
Subject(s)
Animals , Animal Welfare , Farms , Goats , Semi-Arid Zone , Guidelines as TopicABSTRACT
ABSTRACT: The aim of this study was to apply a protocol based on the Animal Welfare Indicators (AWIN) protocols for small ruminants in Brazilian Northeast farms to evaluate the welfare of meat goat, comparing animals kept on semi-intensive (S) and extensive (E) farms. Fifteen farms located in the Metropolitan Region of Quixadá and Quixeramobim, Ceará, Brazilian Northeast, were recruited. Assessments were performed at group and individual level. Significant differences between S and E farms was set at P<0.05 to all tests. At group level, there was a significant difference between groups, with more goats from E farms affected by heat stress and more animals from S farms presenting oblivion. Resource-based indicators, type of drinkers and access to shelter, differed significantly between S and E systems, with goats on S farms allocated in places with access to water more frequently during night period and protected from wind. Type of facility was more complex for animals on S farms (n=2) than on all E farms due to internal divisions, with S farms presenting feeders, drinking fountains, salt shakers, and slatted or cemented floor. At individual level, abscess and ocular discharge were more frequently observed on S farms and ears lesions were more frequent on E farms, probably due to distinct management of goats. Similarities between results showed that farmers in both production systems faced problems related to heat stress, lack of forage and health issues.
RESUMO: O objetivo deste estudo foi aplicar um protocolo baseado nos protocolos Animal Welfare Indicators (AWIN) de pequenos ruminantes em fazendas do nordeste brasileiro para avaliar o bem-estar de cabras de corte, comparando animais mantidos em fazendas semi-intensivas (S) e extensivas (E). Quinze fazendas localizadas na Região Metropolitana de Quixadá e Quixeramobim, no Ceará, Nordeste do Brasil, foram recrutadas. As avaliações foram realizadas no nível de grupo e individual. A diferença significativa entre as fazendas S e E foi estabelecida em P<0,05 para todos os testes. No nível de grupo, houve diferença significativa, com mais cabras do grupo E afetadas por estresse térmico e do grupo S apresentando apatia. Indicadores baseados em recursos, tipo de bebedores e acesso a abrigos diferiram significativamente entre os sistemas S e E, com cabras em fazendas S alocadas em locais com acesso à água durante o período noturno mais frequentemente e protegidas do vento. O tipo de instalação era mais complexo para os animais nas fazendas S (n=2) do que nas fazendas E, devido as divisões internas, com a presença de comedouros, bebedouros, saleiros, piso ripado ou cimentado em fazendas S. A nível individual, abscesso e secreção ocular foram observados mais frequentemente nas fazendas S, e lesões nas orelhas, nas fazendas E, provavelmente devido ao manejo distinto das cabras. Semelhanças entre os resultados mostraram que os fazendeiros de ambos os sistemas de produção enfrentam problemas relacionados ao estresse térmico, falta de forragem e problemas de saúde.
ABSTRACT
O consumo alimentar residual é uma medida de eficiência alimentar independente do crescimento e do peso à maturidade. O melhoramento genético, ao utilizar o consumo alimentar residual como critério de seleção, poderia reduzir os custos com alimentação, haja vista as diferenças existentes na ingestão de matéria seca dos animais com o mesmo ganho médio diário em peso. Frente às vantagens da sua utilização em programas de melhoramento genético, o alto custo para sua determinação limita sua adoção, pois é necessária a coleta individual dos dados de ingestão de alimentos dos animais. Além disso, o conhecimento incompleto dos mecanismos biológicos relacionados ao aumento da eficiência alimentar dificulta a identificação e posterior seleção dos animais de genética superior. Esta revisão aborda aspectos gerais do consumo alimentar residual enfocando as metodologias de predição do consumo de matéria seca e a utilização dos hormônios leptina e IGF-I como indicadores fisiológicos e marcadores moleculares na tentativa de identificar animais eficientes.(AU)
The residual feed intake is a measure of feed efficiency independent growth and weight at maturity. Genetic improvement by using the residual feed intake as a selection criterion, could to reduce feed costs, due differences in dry matter intake of animals with the same average daily gain in weight. Against the advantages of its use in breeding programs, the high cost for their determination limits its adoption, it is necessary to collect data from individual feed intake of animals. Furthermore, the incomplete knowledge of biological mechanisms related to increase feed efficiency complicates the identification and subsequent selection of animals for genetic studies. This review covers general aspects of residual feed intake focusing on the methodologies for predicting dry matter intake and the use of leptin and IGF-I as indicators of physiological and molecular markers in an attempt to identify efficient animals.(AU)
Subject(s)
Animals , Eating , Animal Feed/economics , Leptin , Insulin-Like Growth Factor I , Weight Gain , Cost-Benefit Analysis , Forecasting/methodsABSTRACT
O consumo alimentar residual é uma medida de eficiência alimentar independente do crescimento e do peso à maturidade. O melhoramento genético, ao utilizar o consumo alimentar residual como critério de seleção, poderia reduzir os custos com alimentação, haja vista as diferenças existentes na ingestão de matéria seca dos animais com o mesmo ganho médio diário em peso. Frente às vantagens da sua utilização em programas de melhoramento genético, o alto custo para sua determinação limita sua adoção, pois é necessária a coleta individual dos dados de ingestão de alimentos dos animais. Além disso, o conhecimento incompleto dos mecanismos biológicos relacionados ao aumento da eficiência alimentar dificulta a identificação e posterior seleção dos animais de genética superior. Esta revisão aborda aspectos gerais do consumo alimentar residual enfocando as metodologias de predição do consumo de matéria seca e a utilização dos hormônios leptina e IGF-I como indicadores fisiológicos e marcadores moleculares na tentativa de identificar animais eficientes.
The residual feed intake is a measure of feed efficiency independent growth and weight at maturity. Genetic improvement by using the residual feed intake as a selection criterion, could to reduce feed costs, due differences in dry matter intake of animals with the same average daily gain in weight. Against the advantages of its use in breeding programs, the high cost for their determination limits its adoption, it is necessary to collect data from individual feed intake of animals. Furthermore, the incomplete knowledge of biological mechanisms related to increase feed efficiency complicates the identification and subsequent selection of animals for genetic studies. This review covers general aspects of residual feed intake focusing on the methodologies for predicting dry matter intake and the use of leptin and IGF-I as indicators of physiological and molecular markers in an attempt to identify efficient animals.