Global population profile of tropical cyclone exposure from 2002 to 2019.

Tropical cyclones have far-reaching impacts on livelihoods and population health that often persist years after the event1-4. Characterizing the demographic and socioeconomic profile and the vulnerabilities of exposed populations is essential to assess health and other risks associated with future tropical cyclone events5. Estimates of exposure to tropical cyclones are often regional rather than global6 and do not consider population vulnerabilities7. Here we combine spatially resolved annual demographic estimates with tropical cyclone wind fields estimates to construct a global profile of the populations exposed to tropical cyclones between 2002 and 2019. We find that approximately 560 million people are exposed yearly and that the number of people exposed has increased across all cyclone intensities over the study period. The age distribution of those exposed has shifted away from children (less than 5 years old) and towards older people (more than 60 years old) in recent years compared with the early 2000s. Populations exposed to tropical cyclones are more socioeconomically deprived than those unexposed within the same country, and this relationship is more pronounced for people exposed to higher-intensity storms. By characterizing the patterns and vulnerabilities of exposed populations, our results can help identify mitigation strategies and assess the global burden and future risks of tropical cyclones.

Scrotal thermographic profile and seminal characteristics of Mangalarga Marchador stallions bred in the Atlantic Rainforest biome / [Perfil termográfico escrotal e características seminais de garanhões Mangalarga Marchador criados no bioma Mata Atlântica]

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.

Changes in the structure and composition of the 'Mexical' scrubland bee community along an elevational gradient.

'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.

Warming from tropical deforestation reduces worker productivity in rural communities.

The accelerating loss of tropical forests in the 21st century has eliminated cooling services provided by trees in low latitude countries. Cooling services can protect rural communities and outdoor workers with little adaptive capacity from adverse heat exposure, which is expected to increase with climate change. Yet little is still known about whether cooling services can mitigate negative impacts of heat on labor productivity among rural outdoor workers. Through a field experiment in Indonesia, we show that worker productivity was 8.22% lower in deforested relative to forested settings, where wet bulb globe temperatures were, on average, 2.84 °C higher in deforested settings. We demonstrate that productivity losses are driven by behavioral adaptations in the form of increased number of work breaks, and provide evidence that suggests breaks are in part driven by awareness of heat effects on work. Our results indicate that the cooling services from forests have the potential for increasing resilience and adaptive capacity to local warming.

Heat-stability study of various insulin types in tropical temperature conditions: New insights towards improving diabetes care.

Strict storage recommendations for insulin are difficult to follow in hot tropical regions and even more challenging in conflict and humanitarian emergency settings, adding an extra burden to the management of people with diabetes. According to pharmacopeia unopened insulin vials must be stored in a refrigerator (2-8°C), while storage at ambient temperature (25-30°C) is usually permitted for the 4-week usage period during treatment. In the present work we address a critical question towards improving diabetes care in resource poor settings, namely whether insulin is stable and retains biological activity in tropical temperatures during a 4-week treatment period. To answer this question, temperature fluctuations were measured in Dagahaley refugee camp (Northern Kenya) using log tag recorders. Oscillating temperatures between 25 and 37°C were observed. Insulin heat stability was assessed under these specific temperatures which were precisely reproduced in the laboratory. Different commercialized formulations of insulin were quantified weekly by high performance liquid chromatography and the results showed perfect conformity to pharmacopeia guidelines, thus confirming stability over the assessment period (four weeks). Monitoring the 3D-structure of the tested insulin by circular dichroism confirmed that insulin monomer conformation did not undergo significant modifications. The measure of insulin efficiency on insulin receptor (IR) and Akt phosphorylation in hepatic cells indicated that insulin bioactivity of the samples stored at oscillating temperature during the usage period is identical to that of the samples maintained at 2-8°C. Taken together, these results indicate that insulin can be stored at such oscillating ambient temperatures for the usual four-week period of use. This enables the barrier of cold storage during use to be removed, thereby opening up the perspective for easier management of diabetes in humanitarian contexts and resource poor settings.

Environmental neurology in the tropics.

We address the impact of the tropical environment on the human nervous system using the multifaceted approach characteristic of environmental neurology. First, environmental factors are examined according to their nature (physical, chemical and biological) and in relation to human activity and behavior. Some factors are specific to the tropics (climate and infections), while others are non-specific (chemicals, human communities and their way of life). Second, we examine the major role of human adaptation to the success of Homo sapiens, with emphasis on the linkage between thermoregulation and sleep-wake regulation. Third, we examine the performance of environmental neurology as a clinical discipline in tropical climates, with focus on the diagnostic and therapeutic challenges posed by human African trypanosomiasis. Finally, the prevention, early detection and monitoring of environmental neurological diseases is examined, as well as links with political and economic factors. In conclusion, practitioners of environmental neurology seek a global, multidisciplinary and holistic approach to understanding, preventing and treating neurological disorders within their purview. Environmental neurology integrates an expanded One Health concept by linking health and wellness to the interaction of plants, animals, humans and the ecosystem. Recent epidemics and the current COVID-19 pandemic exemplify the need for worldwide action to protect human health and biodiversity.

Dynamic symbioses reveal pathways to coral survival through prolonged heatwaves.

Prospects for coral persistence through increasingly frequent and extended heatwaves seem bleak. Coral recovery from bleaching is only known to occur after temperatures return to normal, and mitigation of local stressors does not appear to augment coral survival. Capitalizing on a natural experiment in the equatorial Pacific, we track individual coral colonies at sites spanning a gradient of local anthropogenic disturbance through a tropical heatwave of unprecedented duration. Unexpectedly, some corals survived the event by recovering from bleaching while still at elevated temperatures. These corals initially had heat-sensitive algal symbiont communities, endured bleaching, and then recovered through proliferation of heat-tolerant symbionts. This pathway to survival only occurred in the absence of strong local stressors. In contrast, corals in highly disturbed areas were already dominated by heat-tolerant symbionts, and despite initially resisting bleaching, these corals had no survival advantage in one species and 3.3 times lower survival in the other. These unanticipated connections between disturbance, coral symbioses and heat stress resilience reveal multiple pathways to coral survival through future prolonged heatwaves.

Influence of climate on the number of hospitalizations for nephrolithiasis in urban regions in Brazil / Influência do clima sobre o número de internações por nefrolitíase em regiões urbanas no Brasil

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.

Influence of climate on the number of hospitalizations for nephrolithiasis in urban regions in Brazil.

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.

Comparison of fungal and bacterial keratitis between tropical and subtropical Taiwan: a prospective cohort study.

BACKGROUND: Fungal keratitis (FK) has been shown to be a climate-sensitive disease. The differentiation between FK from bacterial keratitis (BK) was difficult. The purpose of this study was to compare the bacteriology and mycology between tropical and subtropical Taiwan and to investigate the independent risk factors for identification of fungi from bacteria. METHODS: Two hundred ninety-seven patients with clinical suspected microbial keratitis were prospectively enrolled. A fungal to bacteria rate (FBR), the number of fungi divided by bacteria identified, was determined to estimate the prevalence of fungi and bacteria. Clinical presentation, profiles of microorganisms, and predisposing risk factors were determined. Univariate and multivariate logistic regression analysis were used to investigate the independent risk factors. RESULTS: A total of 82 fungi and 143 bacteria were laboratory confirmed. The identification rate of fungus was higher in tropical Taiwan (p = 0.010). Among the fungi and bacteria confirmed, the FBR was 0.29 (22.4% vs. 77.6%) in subtropical Taiwan, and 0.70 (41.3% vs. 58.7%) in tropical Taiwan. Samples obtained in tropical area (p = 0.019), ocular trauma (p = 0.019), and plant exposure (p = 0.003) were independent risk factors for identification of fungus from bacteria. The predominant fungus isolated from corneal scraping were Fusarium solani (25%) and Trichosporon faecale (25%) in subtropical Taiwan; in tropical Taiwan was Fusarium spp. (50%). CONCLUSIONS: The identification rate of fungus was higher in tropical Taiwan than subtropical Taiwan. Awareness of the local epidemiology is crucial for early diagnosis of fungal keratitis in tropical area.

Severe below-maintenance feed intake increases methane yield from enteric fermentation in cattle.

The relationship between feed intake at production levels and enteric CH4 production in ruminants consuming forage-based diets is well described and considered to be strongly linear. Unlike temperate grazing systems, the intake of ruminants in rain-fed tropical systems is typically below maintenance requirements for part of the year (dry seasons). The relationship between CH4 production and feed intake in animals fed well below maintenance is unexplored, but changes in key digestive parameters in animals fed at low levels suggest that this relationship may be altered. We conducted a study using Boran yearling steers (n 12; live weight: 162·3 kg) in a 4 × 4 Latin square design to assess the effect of moderate to severe undernutrition on apparent digestibility, rumen turnover and enteric CH4 production of cattle consuming a tropical forage diet. We concluded that while production of CH4 decreased (1133·3-65·0 g CH4/d; P < 0·0001), over the range of feeding from about 1·0 to 0·4 maintenance energy requirement, both CH4 yield (29·0-31·2 g CH4/kg DM intake; P < 0·001) and CH4 conversion factor (Ym 9·1-10·1 MJ CH4/MJ gross energy intake; P < 0·01) increased as intake fell and postulate that this may be attributable to changes in nutrient partitioning. We suggest there is a case for revising emission factors of ruminants where there are seasonal nutritional deficits and both environmental and financial benefits for improved feeding of animals under nutritional stress.

Ambulance Services Associated with Extreme Temperatures and Fine Particles in a Subtropical Island.

This study evaluated the association between the risk of events requiring ambulance services and the ambient temperature and particulate matter of 2.5 µm (PM2.5) and 10 µm (PM10) for populations living in subtropical Taiwan. We used a distributed lag nonlinear model with a quasi-Poisson function to assess the roles of ambient temperature, PM10 and PM2.5 in the use of ambulance services for respiratory distress, coma and unconsciousness, chest pain, lying down in public, headaches/dizziness/vertigo/fainting/syncope and out-of-hospital cardiac arrest (OHCA). The relative risk (RR) and 95% confidence interval (CI) of each specific event were calculated in association with the ambient conditions. In general, the events that required ambulance services had a V-shaped or J-shaped association with the temperature, where the risks were higher at extreme temperatures. The RR of each event was significant when the patients were exposed to temperatures in the 5th percentile (<15 °C); patients with OHCA had the highest adjusted RR of 1.61 (95% CI = 1.47-1.77). The risks were also significant for coma/unconsciousness, headaches/dizziness/vertigo/fainting/syncope, and OHCA but not for respiratory distress, chest pain and lying down in public, after exposure to the 99th percentile temperatures of >30 °C. The risks for use of ambulance services increased with PM exposure and were significant for events of respiratory distress, chest pain and OHCA after exposure to the 99th percentile PM2.5 after controlling for temperatures. Events requiring ambulance services were more likely to occur when the ambient temperature was low than when it was high for the population on the subtropical island of Taiwan. The association of the risk of events requiring ambulance services with PM were not as strong as the association with low temperatures.

High heat tolerance in plants from the Andean highlands: Implications for paramos in a warmer world.

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.

[Meteorological variables and air pollution and their association with hospitalizations due to respiratory diseases in children: a case study in São Paulo, Brazil]. / Variáveis meteorológicas e poluição do ar e sua associação com internações respiratórias em crianças: estudo de caso em São Paulo, Brasil.

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.

Temperature rising would slow down tropical forest dynamic in the Guiana Shield.

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.

Two different types of botulinum toxins: Is there a difference in efficacy and longevity?

BACKGROUND: OnabotulinumtoxinA and incobotulinumtoxinA are two botulinum toxin A (BoNT-A) formulations commonly used in esthetic medicine. They are distinguished by whether complexing proteins are included with the active neurotoxin. While OnabotulinumtoxinA has complexing proteins, incobotulinumtoxinA does not; yet, it is unclear whether these differences affect their efficacy, longevity, and immunogenicity, especially in practices with high ambient temperatures. OBJECTIVES: To assess the efficacy and longevity of unreconstituted incobotulinumtoxinA with unreconstituted OnabotulinumtoxinA when stored and transported in a cold box to areas with high external ambient temperatures and to understand the implications of storing and transporting botulinum toxin to tropical areas with high ambient temperatures. METHODS: A prospective, randomized, and evaluator-blinded split-face trial was conducted in 30 patients with symmetrical, moderate-to-severe forehead lines. Following routine transportation and storage in thermocol cold boxes, OnabotulinumtoxinA or incobotulinumtoxinA was injected into corresponding sides of the frontalis to facilitate analysis within the same patient. Using a 4-point facial wrinkling grading scale and a clinical improvement scale, patients' outcomes were assessed over 24 weeks. RESULTS: Forehead lines reappeared in OnabotulinumtoxinA-treated patients after 8.3 weeks, compared to 10.1 weeks in incobotulinumtoxinA-treated patients. While side-vs-side improvements in forehead lines were observed for both toxins, after 8 weeks, improvements from were diminished relative to incobotulinumtoxinA, indicating that incobotulinumtoxinA was more effective at prolonged wrinkle relief. CONCLUSIONS: These results suggest that incobotulinumtoxinA is more stable at higher ambient temperatures, thus contributing to its better efficacy and longevity. IncobotulinumtoxinA is therefore more appropriate for practices in tropical climates.

Impact of Weather Conditions on Atopic Dermatitis Prevalence in Abuja, Nigeria.

BACKGROUND: Climatic conditions may trigger subclinical disease in predisposed individuals and also exacerbate eczematous symptoms resulting in persistence or increased frequency of atopic dermatitis (AD) flares. The aim of this study is to assess the impact of tropical weather conditions on the frequency at which atopic dermatitis patients present at the dermatology clinic of a tertiary hospital in Abuja, Nigeria; and, to find out which component of these conditions exerts the most significant effects. METHODS: Medical records of all new patients seen at the clinic within July 2015 and June 2017 was obtained. Data for monthly temperature, humidity, precipitation, cloud cover and UV index of Abuja during this period was obtained from worldweatheronline. Univariate analyses and multiple regressions were used to assess the associations between monthly prevalence of AD and the above-mentioned meteorological variables. RESULTS: Patients had a 1.6 times odds (95% CI: 1.03-2.56, p = 0.038) of presenting with AD in the dry season as compared to wet season. Dry season was associated with higher temperatures and UV index and lower precipitation, humidity and cloud cover, p<0.001. Multivariate logistic regression modelling adjusting for precipitation, humidity, cloud cover and age group demonstrated that precipitation (OR = 1.01, 95% CI: 1.00-1.02, p = 0.002), humidity (OR = 1.03, 95% CI:1.01-1.05, p = 0.015) and cloud cover (OR = 0.92, 95% CI: 0.88-1.02, p = 0.002) exert the most significant effects. Also infants had 4.4 times odds of AD than adults (95% CI: 2.04-9.69, p<0.001). CONCLUSION: Exposure to tropical season meteorological variables can influence the presentation of AD.

Seasonal aggravation of acne in summers and the effect of temperature and humidity in a study in a tropical setting.

BACKGROUND: Effect of seasonality on acne and acne flare has varied interpretations depending on the geographical area of study. In tropical areas, factors like high temperature and humidity may cause acne flares. AIMS: To assess the seasonal variation of acne in patients and to correlate it with the monthly temperature and humidity over a period of 1 year. METHODS: A cross-sectional study of acne patients was conducted for one year. The patient's acne was graded. Patients were specifically questioned about aggravation, improvement, or no change in their acne with respect to the seasons. The mean temperature and humidity of each month in Delhi were compared with grade of acne. This variation in acne was correlated with the temperature and humidity. A P-value < 0.05 was considered as statistically significant. RESULTS: Out of 171 patients, 82 (47.95%) patients reported seasonal variation in their acne. Among them, 69 patients (40.4%) reported aggravation in summer. Eleven (6.42%) and 2 (1.16%) patients reported aggravation in winter and rainy season, respectively. The aggravation in summer as compared to rainy and winter season was statistically significant. The mean temperature and mean humidity significantly varied with seasonal aggravation of acne. CONCLUSIONS: Both temperature and humidity have a contributing role in pathogenesis of acne and are causes of acne flare. In our study, aggravation of acne was more in summer and rainy season.

Beta-Expansin of Bermuda, Johnson, and Para grass pollens, is a major cross-reactive allergen for Allergic Rhinitis patients in subtropical climate.

BACKGROUND: Subtropical grass pollens of Bermuda (BGP), Johnson (JGP), and Para or buffalo grass (PGP), are common causes of pollen allergies in warm climate area. Allergic rhinitis (AR) patients had positive skin prick test (SPT) to extract of these 3 grass pollens. However, no allergenic proteins of 3 grass pollens have never been studied. OBJECTIVE: To identify major allergens of BGP, JGP, and PGP in Thai grass pollen-allergic patients and to examine their sIgE cross-reactivity. METHODS: Serum of nine AR patients with positive SPT to at least 2 of 3 studied pollens were collected. Based on availability, only ImmunoCAP of BGP and JGP were available to determine a level of sIgE. Profiles of sIgE bound proteins from BGP, JGP, and PGP, were obtained by immunoblot. Major IgE bound protein was identified by liquid chromatography-tandem mass spectrophotometry (LC-MS/MS). Cross-reactivity of purified major allergen of the 3 grass pollens was determined by inhibition of sIgE in both ELISA and immunoblot. RESULTS: AR patients who have positive SPT to extract of BGP, JGP, and PGP, were 9, 8, and 6, respectively. Positive sIgE (> 0.35 kUA/L) to BGP and JGP were found in 9 and 8 patients, respectively. Eight profiles of IgE bound proteins of the 3 grass pollens showed 29-30 kDa pollen protein as major allergen and was identified as beta-expansin (ExpB). Moreover, purified ExpB of the 3 grass pollens cross-inhibited serum sIgE. CONCLUSION: ~30 kDa ExpB of BGP, JGP, and PGP, is major cross-reactive allergen for AR Thai patients.

A cross-sectional study of sweat-induced dermatitis during a South Indian summer: a glimpse of sweat gland-mediated cutaneous inflammation.

BACKGROUND: The role of sweat gland in inflammation has not received sufficient attention. The thermal stress during the summer months in tropical areas provides an opportunity to study the morphological patterns of inflammation produced primarily by the sweat gland. AIM: To collect clinical data on sweat-induced dermatitis during the summer months. METHODS: A hospital-based descriptive cross-sectional study was done during the hot and humid summer months of April to June in a tertiary care institute in Puducherry. Patients clinically diagnosed with sweat-induced dermatitis (dermatitis primarily due to retention or extravasation of sweat) were included in the study. A detailed history was taken, and clinical examination was done. RESULTS: One hundred and fifty patients were included in the study. Various typical and atypical manifestations of sweat-induced dermatitis were seen. "Sweat dermatitis" presenting with dry, hyperpigmented, fissured "parchment"-like skin, shiny "crinkled cellophane paper"-like skin, or asymptomatic hyperpigmented macules was seen. Other atypical presentations included miliaria pustulosa with "hypopyon sign" and "linear and parallel ridge pattern" of dermatitis in patients with miliaria rubra affecting the lower neck and upper chest. CONCLUSION: A wide spectrum of sweat-induced dermatitis was seen during the summer months in a tropical region. It reflects the role of the sweat gland in cutaneous inflammation. An increased awareness of atypical manifestations is needed.