RESUMO
The objective of this study was to determine the scrotal thermographic profile and to verify the influence of temperature and humidity of the humid tropical climate on testicular temperature and seminal quality of Mangalarga Marchador stallions. The thermal profiles of the proximal, middle, and distal zones of the testicles and total surface temperature (TSTT) were recorded using an FLIR E60bx thermal imager. The average air temperature (°C) and relative humidity (%) were obtained 1, 5, 9, 33, and 66 days before semen collection and showed a mean value of 26.5±2.4 and 80.4±6.0 respectively. The scrotal surface temperature was close to 34°C and there was no variation with the age of the stallion, reproductive activity, and characteristics of the ejaculate (P>0.05). The only significant correlations obtained were between TSTT and minor defects (R = 0.41; P<0.05), between TSTT and total defects (R = 0.46; P<0.01), and between TSTT and percentage of morphologically normal sperm (R = -0.46; P<0.05). It was concluded that the Mangalarga Marchador stallions maintained the testicular temperature within favorable conditions for spermatogenesis, demonstrating the efficiency of testicular thermoregulation mechanisms in the Atlantic Forest biome.
O objetivo deste estudo foi determinar o perfil termográfico escrotal e verificar a influência da temperatura e da umidade do clima tropical úmido na temperatura testicular e na qualidade seminal de garanhões Mangalarga Marchador. Os perfis térmicos das zonas proximal, média e distal dos testículos e a temperatura da superfície total (TSTT) foram registrados usando-se um termovisor FLIR E60bx. A temperatura média do ar (° C) e a umidade relativa (%) foram obtidas um, cinco, nove, 33 e 66 dias antes da coleta de sêmen e apresentaram valor médio de 26,5 ± 2,4 e 80,4 ± 6,0, respectivamente. A temperatura da superfície escrotal foi próxima a 34°C, e não houve variação com a idade do garanhão, a atividade reprodutiva e as características do ejaculado (P>0,05). As únicas correlações significativas obtidas foram entre TSTT e defeitos menores (R=0,41; P<0,05), entre TSTT e defeitos totais (R=0,46; P<0,01), e entre TSTT e porcentagem de espermatozoides morfologicamente normais (R=-0,46; P<0,05). Concluiu-se que os garanhões Mangalarga Marchador mantiveram a temperatura testicular dentro de condições favoráveis para a espermatogênese, demonstrando a eficiência dos mecanismos de termorregulação testicular no bioma Mata Atlântica.
Assuntos
Animais , Masculino , Espermatogênese/efeitos da radiação , Temperatura , Testículo , Regulação da Temperatura Corporal , Análise do Sêmen/veterinária , Cavalos/fisiologia , Umidade/efeitos adversos , Sêmen , Clima Tropical/efeitos adversos , Termografia/veterináriaRESUMO
'Mexical' scrubland is a sclerophyllous evergreen Mediterranean-like vegetation occurring in the leeward slopes of the main Mexican mountain ranges, under tropical climate. This biome occupies an elevational range approximately from 1900 to 2600 meters above sea level, which frequently is the upper-most part of the mountains range. This puts it at risk of extinction in a scenario of global warming in which an upward retraction of this type of vegetation is expected. The Mexical remains one of the least studied ecosystems in Mexico. For instance, nothing is known about pollinator fauna of this vegetation. Our main objective is to make a first insight into the taxonomic identity of the bee fauna that inhabits this biome, and to study how it is distributed along the elevational gradient that it occupies. Our results highlight that elevation gradient negatively affects bee species richness and that this relationship is strongly mediated by temperature. Bee abundance had no significant pattern along elevational gradient, but shows a significant relationship with flower density. Interestingly, and contrary to previous works, we obtained a different pattern for bee richness and bee abundance. Bee community composition changed strongly along elevation gradient, mainly in relation to temperature and flower density. In a global warming scenario, as temperatures increases, species with cold preferences, occupying the highest part of the elevation gradient, are likely to suffer negative consequences (even extinction risk), if they are not flexible enough to adjust their physiology and/or some life-story traits to warmer conditions. Species occupying mid and lower elevations are likely to extend their range of elevational distribution towards higher ranges. This will foreseeably cause a new composition of species and a new scenario of interactions, the adjustment of which still leaves many unknowns to solve.
Assuntos
Abelhas/fisiologia , Ecossistema , Flores/crescimento & desenvolvimento , Aquecimento Global , Altitude , Animais , Biodiversidade , México , Polinização/fisiologia , Temperatura , Clima Tropical/efeitos adversosRESUMO
Abstract Introduction: Nephrolithiasis has a worldwide prevalence of approximately 5 to 15%, and its occurrence is associated with age, sex, race, dietary habits, geographic location, climatic conditions, and other factors. The objective of the present study was to determine the association between climate and the number of hospitalizations for nephrolithiasis (NH) in Brazilian cities located in different climatic regions. Methods: We analyzed data from cities with tropical and subtropical climates. The effects of the lowest (LT), mean (MT), and highest (HT) monthly temperatures and relative humidity of the air (RH) were assessed. Results: A positive association was found between the number of hospitalizations for nephrolithiasis and temperature ((LT x NH; R2=0.218; P<0.0001) (MT x NH; R2=0.284; P<0.0001) (HT x NH; R2=0.317; P<0.0001)), and a negative association was found between the number of hospitalizations for nephrolithiasis and the relative humidity (RH x NH; R2=0.234; P<0.0001). Interactions were also observed between MT and RH with respect to their effects on the NH, as described by a linear model (NH = 4.688 + 0.296 x MT - 0.088 x RH). The NH was higher in cities with tropical climates than in cities with subtropical climates (82.4 ± 10.0 vs 28.2 ± 1.6; P<0.00001). Conclusion: There is an association between the NH and variations in temperature and relative humidity.
Resumo Introdução: A prevalência mundial da nefrolitíase situa-se entre 5% e 15%. Sua ocorrência está associada a idade, sexo, raça, hábitos alimentares, localização geográfica, condições climáticas e outros fatores. O objetivo do presente estudo foi determinar a associação entre clima e número de internações por nefrolitíase (IN) em cidades brasileiras localizadas em diferentes regiões climáticas. Métodos: Analisamos dados de cidades com climas tropicais e subtropicais. Nossa avaliação considerou os efeitos das temperaturas mensais mais baixas (TMB), sua média (TM) e mais altas (TMA) e da umidade relativa do ar (UR). Resultados: Foi identificada associação positiva entre o número de internações por nefrolitíase e temperatura ((TMB vs. IN; R2 = 0,218; P<0,0001) (TM vs. IN; R2 = 0,284; P<0,0001) (TMA vs. IN; R2 = 0,317; P<0,0001)) e associação negativa entre o número de internações por nefrolitíase e umidade relativa do ar (UR vs. IN; R2 = 0,234; P <0,0001). Também foram observadas interações entre TM e UR com relação aos seus efeitos sobre a IN, conforme descrito por um modelo linear (IN = 4,668 + 0,296 x TM - 0,088 x UR). IN foi mais acentuada nas cidades com climas tropicais do que nas cidades com climas subtropicais (82,4 ± 10,0 vs. 28,2 ± 1,6; P<0,00001). Conclusão: Existe associação entre IN e variações de temperatura e umidade relativa.
Assuntos
Humanos , Masculino , Feminino , Lactente , Pré-Escolar , Criança , Adolescente , Adulto , Pessoa de Meia-Idade , Adulto Jovem , Clima Tropical/efeitos adversos , Nefrolitíase/epidemiologia , Hospitalização/estatística & dados numéricos , Umidade/efeitos adversos , Temperatura , População Urbana , Mudança Climática/estatística & dados numéricos , Brasil/epidemiologia , Modelos Lineares , Prevalência , Estudos Retrospectivos , ClimaRESUMO
INTRODUCTION: Nephrolithiasis has a worldwide prevalence of approximately 5 to 15%, and its occurrence is associated with age, sex, race, dietary habits, geographic location, climatic conditions, and other factors. The objective of the present study was to determine the association between climate and the number of hospitalizations for nephrolithiasis (NH) in Brazilian cities located in different climatic regions. METHODS: We analyzed data from cities with tropical and subtropical climates. The effects of the lowest (LT), mean (MT), and highest (HT) monthly temperatures and relative humidity of the air (RH) were assessed. RESULTS: A positive association was found between the number of hospitalizations for nephrolithiasis and temperature ((LT x NH; R2=0.218; P<0.0001) (MT x NH; R2=0.284; P<0.0001) (HT x NH; R2=0.317; P<0.0001)), and a negative association was found between the number of hospitalizations for nephrolithiasis and the relative humidity (RH x NH; R2=0.234; P<0.0001). Interactions were also observed between MT and RH with respect to their effects on the NH, as described by a linear model (NH = 4.688 + 0.296 x MT - 0.088 x RH). The NH was higher in cities with tropical climates than in cities with subtropical climates (82.4 ± 10.0 vs 28.2 ± 1.6; P<0.00001). CONCLUSION: There is an association between the NH and variations in temperature and relative humidity.
Assuntos
Hospitalização/estatística & dados numéricos , Umidade/efeitos adversos , Nefrolitíase/epidemiologia , Clima Tropical/efeitos adversos , Adolescente , Adulto , Idoso , Brasil/epidemiologia , Criança , Pré-Escolar , Clima , Mudança Climática/estatística & dados numéricos , Feminino , Humanos , Lactente , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Prevalência , Estudos Retrospectivos , Temperatura , População Urbana , Adulto JovemRESUMO
Tropical plant species are expected to have high heat tolerance reflecting phenotypic adjustments to warm regions or their evolutionary adaptation history. However, tropical highland specialists adapted to the colder temperatures found in the highlands, where short and prostrated vegetation decouples plants from ambient conditions, could exhibit different upper thermal limits than those of their lowland counterparts. Here we evaluated leaf heat tolerance of 21 tropical alpine paramo species to determine: 1) whether species with restricted distribution (i.e., highland specialists) have lower heat tolerance and are more vulnerable to warming than species with widespread distribution; 2) whether different growth forms have different heat tolerance; and 3) whether species height (i.e., microhabitat) influences its heat tolerance. We quantified heat tolerance by evaluating T50, which is the temperature that causes a reduction in 50% of initial Fv/Fm values and reflects an irreversible damage to the photosynthetic apparatus. Additionally, we estimated the thermal safety margins as the difference between T50 and the maximum leaf temperature registered for the species. All species presented high T50 values ranging between 45.4°C and 53.9°C, similar to those found for tropical lowland species. Heat tolerance was not correlated with species distributions or plant height, but showed a strong relationship with growth form, with rosettes having the highest heat tolerance. Thermal safety margins ranged from 12.1 to 31.0°C. High heat tolerance and broad thermal safety margins suggest low vulnerability of paramo species to warming as long as plants are capable of regulating the leaf temperature within this threshold. Whether paramo plants would be able to regulate leaf temperature if drought episodes become more frequent and transpirational cooling is compromised is the next question that needs to be answered.
Assuntos
Mudança Climática , Folhas de Planta/fisiologia , Termotolerância/fisiologia , Clima Tropical/efeitos adversos , Tundra , Colômbia , Temperatura Alta/efeitos adversos , Dispersão Vegetal/fisiologiaRESUMO
Urban climate changes, excessive air pollution, and increasing social inequalities have become determinant factors in the high risk of hospitalizations due to respiratory diseases. The current study thus aimed to understand how meteorological factors (air temperature, relative humidity, and precipitation) and air pollution (particulate matter with aerodynamic diameter less than 10µm - PM10) are related to hospitalizations due to respiratory diseases in children in 14 districts in the city of São Paulo, Brazil. The combination of generalized linear models with a negative binomial distribution and distributed lag non-linear model (DLNM) were used as the statistical method to analyze the relationship between hospitalizations, climatic factors, and pollution from 2003 to 2013. The results show statistically significant association with high relative risk between mean air temperature (17.5ºC to 21ºC, for the total analyzed), relative humidity (84% to 98% for females), precipitation (0mm to 2.3mm for the total and both sexes and > 120mm for females), and PM10 (> 35µg/m³ for the total and for females). These results showed that environmental factors contribute to the high risk of hospitalizations.
As transformações no clima urbano das cidades, a excessiva poluição atmosférica e o aumento das desigualdades sociais tornaram-se fatores determinantes do alto risco de internações por doenças respiratórias. Dessa forma, o objetivo deste trabalho foi compreender como os atributos meteorológicos (temperatura do ar, umidade relativa do ar e precipitação) e a poluição do ar (material particulado com diâmetro aerodinâmico menor de 10µm - MP10) estão relacionados com as internações hospitalares por doenças respiratórias em crianças, em 14 distritos da cidade de São Paulo, Brasil. A combinação dos modelos lineares generalizados com uma distribuição binomial negativa e o modelo não linear distributed lag non-linear model (DLNM) foram utilizados como método estatístico para analisar a relação entre as internações, os atributos climáticos e a poluição no período de 2003 a 2013. Os resultados mostraram relações estatísticas significativas de alto risco relativo entre a temperatura média do ar (17,5ºC a 21ºC, para o total analisado), umidade relativa do ar (84% a 98% para o sexo feminino), precipitação (0mm a 2,3mm para o total e ambos os sexos e > 120mm para o sexo feminino) e MP10 (> 35µg/m³ para o total e para o sexo feminino). Com base nesses resultados, foi possível identificar que os atributos ambientais contribuem para o elevado risco de internações.
Las transformaciones en el clima urbano de las ciudades, la excesiva contaminación atmosférica y el aumento de las desigualdades sociales se convirtieron en factores determinantes para el alto riesgo de internamientos por enfermedades respiratorias. Por ello, el objetivo de este trabajo ha sido comprender cómo las condiciones meteorológicas (temperatura del aire, humedad relativa del aire y precipitaciones) y la contaminación del aire (material particulado con un diámetro aerodinámico menor de 10µm - MP10) están relacionados con internamientos hospitalarios por enfermedades respiratorias en niños, en 14 distritos de la ciudad de Sao Paulo. La combinación de los modelos lineales generalizados con una distribución binomial negativa y el modelo no lineal distributed lag non-linear model (DLNM) se utilizaron como método estadístico para analizar la relación entre los internamientos, atributos climáticos y la contaminación durante el período de 2003 a 2013. Los resultados mostraron relaciones estadísticas significativas de alto riesgo relativo entre la temperatura media del aire (17,5ºC a 21ºC, para el total analizado), humedad relativa del aire (84% a 98% para el sexo femenino), precipitaciones (0mm a 2,3mm para el total y ambos sexos y > 120mm para el sexo femenino) y MP10 (> 35µg/m³ para el total y sexo femenino). A partir de estos resultados, fue posible identificar que los atributos ambientales contribuyen al aumento del riesgo de internamientos.
Assuntos
Poluição do Ar/efeitos adversos , Hospitalização/estatística & dados numéricos , Transtornos Respiratórios/etiologia , Tempo (Meteorologia) , Poluentes Atmosféricos/análise , Poluição do Ar/análise , Brasil , Criança , Pré-Escolar , Cidades , Feminino , Humanos , Umidade/efeitos adversos , Lactente , Recém-Nascido , Masculino , Chuva , Temperatura , Clima Tropical/efeitos adversosRESUMO
Increasing evidence shows that the functioning of the tropical forest biome is intimately related to the climate variability with some variables such as annual precipitation, temperature or seasonal water stress identified as key drivers of ecosystem dynamics. How tropical tree communities will respond to the future climate change is hard to predict primarily because several demographic processes act together to shape the forest ecosystem general behavior. To overcome this limitation, we used a joint individual-based model to simulate, over the next century, a tropical forest community experiencing the climate change expected in the Guiana Shield. The model is climate dependent: temperature, precipitation and water stress are used as predictors of the joint growth and mortality rates. We ran simulations for the next century using predictions of the IPCC 5AR, building three different climate scenarios (optimistic RCP2.6, intermediate, pessimistic RCP8.5) and a control (current climate). The basal area, above-ground fresh biomass, quadratic diameter, tree growth and mortality rates were then computed as summary statistics to characterize the resulting forest ecosystem. Whatever the scenario, all ecosystem process and structure variables exhibited decreasing values as compared to the control. A sensitivity analysis identified the temperature as the strongest climate driver of this behavior, highlighting a possible temperature-driven drop of 40% in average forest growth. This conclusion is alarming, as temperature rises have been consensually predicted by all climate scenarios of the IPCC 5AR. Our study highlights the potential slow-down danger that tropical forests will face in the Guiana Shield during the next century.
Assuntos
Temperatura Alta/efeitos adversos , Floresta Úmida , Clima Tropical/efeitos adversos , Biomassa , Mudança Climática , Ecossistema , Florestas , Guiana , Modelos Biológicos , América do Sul , Temperatura , ÁrvoresRESUMO
Background: Thermal stress indices are important in predicting and choosing means for mitigating heat stress and defining critical environmental conditions for animal welfare and performance. The aim of this study was to determine theassociation between 16 thermal stress indices and thermophysiological variables in young Nellore bulls raised in a tropicalpasture to determine the most effective parameter of heat stress to assist in the management of the thermal environmentand animal welfare.Materials, Methods & Results: Seventy-eight young Nellore bulls (Bos taurus indicus), with a mean age of 10.5 monthsand mean body weight of 242.09 ± 32.17 kg at first collection, and 17.92 months and body weight 335.80 ± 39.02 kg atlast collection, were used. During the experimental period, rectal temperature (RT) and surface temperature at the forehead,scapula, and groin, from which the average surface temperature (AST) was calculated, were measured. The differencebetween the AST and air temperature (i.e., AST - AT) and between the RT and AST (i.e., RT - AST) defined the thermalgradient. For the evaluation of thermal environment, the dry bulb, wet bulb, and globe temperatures, and wind speed weremeasured. Relative humidity, mean radiant temperature, solar radiation, temperature humidity index (THI), black globaltemperature humidity index (BGHI), equivalent temperature index (ETI), environmental stress index (ESI), respiratory ratepredictor (PRR), heat load index (HLI), comprehensive climate index (CCI), and index of thermal stress for cows (ITSC)were calculated. The average and maximum air temperatures were above thermal comfort levels, while the average relativehumidity was within the ideal limit for cattle. The average globe temperature was higher than the air temperature. Solarradiation presented very high values and wind speeds were very low. RT indicated normothermia in the cattle, and ASTand thermal gradient (i.e., AST - AT) indicated thermal comfort...(AU)
Assuntos
Animais , Masculino , Bovinos , Transtornos de Estresse por Calor/classificação , Transtornos de Estresse por Calor/diagnóstico , Transtornos de Estresse por Calor/veterinária , Temperatura Corporal , Umidade , Clima Tropical/efeitos adversosRESUMO
As transformações no clima urbano das cidades, a excessiva poluição atmosférica e o aumento das desigualdades sociais tornaram-se fatores determinantes do alto risco de internações por doenças respiratórias. Dessa forma, o objetivo deste trabalho foi compreender como os atributos meteorológicos (temperatura do ar, umidade relativa do ar e precipitação) e a poluição do ar (material particulado com diâmetro aerodinâmico menor de 10μm - MP10) estão relacionados com as internações hospitalares por doenças respiratórias em crianças, em 14 distritos da cidade de São Paulo, Brasil. A combinação dos modelos lineares generalizados com uma distribuição binomial negativa e o modelo não linear distributed lag non-linear model (DLNM) foram utilizados como método estatístico para analisar a relação entre as internações, os atributos climáticos e a poluição no período de 2003 a 2013. Os resultados mostraram relações estatísticas significativas de alto risco relativo entre a temperatura média do ar (17,5ºC a 21ºC, para o total analisado), umidade relativa do ar (84% a 98% para o sexo feminino), precipitação (0mm a 2,3mm para o total e ambos os sexos e > 120mm para o sexo feminino) e MP10 (> 35µg/m³ para o total e para o sexo feminino). Com base nesses resultados, foi possível identificar que os atributos ambientais contribuem para o elevado risco de internações.
Urban climate changes, excessive air pollution, and increasing social inequalities have become determinant factors in the high risk of hospitalizations due to respiratory diseases. The current study thus aimed to understand how meteorological factors (air temperature, relative humidity, and precipitation) and air pollution (particulate matter with aerodynamic diameter less than 10µm - PM10) are related to hospitalizations due to respiratory diseases in children in 14 districts in the city of São Paulo, Brazil. The combination of generalized linear models with a negative binomial distribution and distributed lag non-linear model (DLNM) were used as the statistical method to analyze the relationship between hospitalizations, climatic factors, and pollution from 2003 to 2013. The results show statistically significant association with high relative risk between mean air temperature (17.5ºC to 21ºC, for the total analyzed), relative humidity (84% to 98% for females), precipitation (0mm to 2.3mm for the total and both sexes and > 120mm for females), and PM10 (> 35µg/m³ for the total and for females). These results showed that environmental factors contribute to the high risk of hospitalizations.
Las transformaciones en el clima urbano de las ciudades, la excesiva contaminación atmosférica y el aumento de las desigualdades sociales se convirtieron en factores determinantes para el alto riesgo de internamientos por enfermedades respiratorias. Por ello, el objetivo de este trabajo ha sido comprender cómo las condiciones meteorológicas (temperatura del aire, humedad relativa del aire y precipitaciones) y la contaminación del aire (material particulado con un diámetro aerodinámico menor de 10µm - MP10) están relacionados con internamientos hospitalarios por enfermedades respiratorias en niños, en 14 distritos de la ciudad de Sao Paulo. La combinación de los modelos lineales generalizados con una distribución binomial negativa y el modelo no lineal distributed lag non-linear model (DLNM) se utilizaron como método estadístico para analizar la relación entre los internamientos, atributos climáticos y la contaminación durante el período de 2003 a 2013. Los resultados mostraron relaciones estadísticas significativas de alto riesgo relativo entre la temperatura media del aire (17,5ºC a 21ºC, para el total analizado), humedad relativa del aire (84% a 98% para el sexo femenino), precipitaciones (0mm a 2,3mm para el total y ambos sexos y > 120mm para el sexo femenino) y MP10 (> 35µg/m³ para el total y sexo femenino). A partir de estos resultados, fue posible identificar que los atributos ambientales contribuyen al aumento del riesgo de internamientos.
Assuntos
Humanos , Masculino , Feminino , Recém-Nascido , Lactente , Pré-Escolar , Criança , Transtornos Respiratórios/etiologia , Poluição do Ar/efeitos adversos , Hospitalização/estatística & dados numéricos , Chuva , Temperatura , Clima Tropical/efeitos adversos , Brasil , Cidades , Poluentes Atmosféricos/análise , Poluição do Ar/análise , Umidade/efeitos adversosRESUMO
Background: Thermal stress indices are important in predicting and choosing means for mitigating heat stress and defining critical environmental conditions for animal welfare and performance. The aim of this study was to determine theassociation between 16 thermal stress indices and thermophysiological variables in young Nellore bulls raised in a tropicalpasture to determine the most effective parameter of heat stress to assist in the management of the thermal environmentand animal welfare.Materials, Methods & Results: Seventy-eight young Nellore bulls (Bos taurus indicus), with a mean age of 10.5 monthsand mean body weight of 242.09 ± 32.17 kg at first collection, and 17.92 months and body weight 335.80 ± 39.02 kg atlast collection, were used. During the experimental period, rectal temperature (RT) and surface temperature at the forehead,scapula, and groin, from which the average surface temperature (AST) was calculated, were measured. The differencebetween the AST and air temperature (i.e., AST - AT) and between the RT and AST (i.e., RT - AST) defined the thermalgradient. For the evaluation of thermal environment, the dry bulb, wet bulb, and globe temperatures, and wind speed weremeasured. Relative humidity, mean radiant temperature, solar radiation, temperature humidity index (THI), black globaltemperature humidity index (BGHI), equivalent temperature index (ETI), environmental stress index (ESI), respiratory ratepredictor (PRR), heat load index (HLI), comprehensive climate index (CCI), and index of thermal stress for cows (ITSC)were calculated. The average and maximum air temperatures were above thermal comfort levels, while the average relativehumidity was within the ideal limit for cattle. The average globe temperature was higher than the air temperature. Solarradiation presented very high values and wind speeds were very low. RT indicated normothermia in the cattle, and ASTand thermal gradient (i.e., AST - AT) indicated thermal comfort...