Metabarcode insights into the airborne fungal diversity in the indoor and outdoor environments in archives from Yunnan, Southwestern China.

Monitoring dynamics of airborne fungal species and controlling of harmful ones are of vital importance to conservation of cultural relics. However, the evaluation of air quality and the community structure characteristics of microorganisms, especially fungi, in the atmosphere of archives is in a stage of continuous exploration though more than 4,000 archives were constructed in China. Seventy-two air samples were collected in this study under different spatial and weather conditions from the archives of Kunming Medical University, located in the Kunming metropolitan area, Yunnan province, southwestern China. A total of 22 airborne fungal classes, 160 genera and 699 ASVs were identified, the species diversity is on the rise with the strengthening of air circulation with the outside space, and thus the intensive energy metabolism and activity were found in the spaces with window and sunny weather, except for the higher lipid synthesis of indoor samples than that of outdoor ones. Furthermore, there were significant differences in fungal community composition and abundance between sunny and rainy weathers. A considerable number of species have been identified as indicator in various environmental and weather conditions of the archives, and temperature and humidity were thought to have significant correlations with the abundance of these species. Meanwhile, Cladosporium and Alternaria were the dominant genera here, which may pose a threat to the health of archive professionals. Therefore, monitoring and controlling the growth of these fungal species is crucial for both conservation of paper records and health of archive professionals.

Influence of Service Conditions and Mix Design on the Physical-Mechanical Properties of Roller-Compacted Concrete for Pavement.

This research focuses on the behavior of roller-compacted concrete (RCC) used in pavements, which are prone to deterioration affecting their performance. These deteriorations result from various causes, including traffic load, errors during construction, mix design, and ambient conditions. Among these, ambient conditions could lead to a marked variable impact on material behavior and durability depending on the conditions associated with each region. Accordingly, this study aims to deepen the understanding of the effect, which a broader range of ambient conditions and different mix designs have on the physical and mechanical properties of RCC. Measurements such as the amount of water vapor per kilogram of air were used to apply the findings comprehensively. The RCC analysis encompassed experimentation with different compositions, altering the cement water ratio amount, and adding a superplasticizer. The impact of curing on the materials was evaluated before subjecting them to various humidity and temperature conditions. Laboratory tests were conducted to measure performance, including moisture, shrinkage, compressive strength, and the progression of flexural fracture resistance over curing periods of up to 90 days. The results revealed a logarithmic correlation between shrinkage and ambient humidity, which is the most determining factor in performance. Mix optimization through increased cement and reduced water enhanced the tensile strength of the material. Furthermore, the curing process was confirmed to increase resistance to shrinkage, especially in the long term, establishing it as a crucial element for the structural stability of RCC, which is relatively insensitive to variations in ambient conditions.

Species-Specific Responses of Insectivorous Bats to Weather Conditions in Central Chile.

Insectivorous bats play a crucial role in agroecosystems by providing invaluable pest control services. With the escalating impacts of climate change, a comprehensive understanding of the environmental factors influencing bat activity becomes imperative for their conservation in agricultural landscapes. This study investigates the influence of weather conditions, specifically air temperature and relative humidity, on the timing activity and the relative abundance of five insectivorous bat species in central Chile. Data from automatic bat detectors and climatological stations are utilized for analysis. Our results unveil species-specific behaviors, with Tadarida brasiliensis exhibiting early emergence and extended activity periods compared to other bat species. Histiotus montanus and Lasiurus villosissimus display delayed onsets on more humid evenings, whereas Lasiurus varius and T. brasiliensis initiate activity earlier on colder nights compared to warmer ones. Relative humidity emerges as a key factor influencing relative abundance for all species, with more minutes with bat passes detected on drier nights. These findings suggest that global warming may influence observed bat behaviors, potentially altering foraging patterns and activity levels of these bat species. Moreover, as climate change continues, understanding the long-term impact on bat populations and their adaptive strategies is crucial for effective conservation measures. Further studies exploring these dynamics can provide valuable insights for shaping conservation efforts in the face of evolving environmental challenges.

Testosterone is closely related to Leydig cell activity, environmental factors, and androgen receptor distribution in adult male lizards of Liolaemus cuyanus (Reptilia: Liolaemidae) during the reproductive cycle.

Testosterone, the primary sex hormone in male lizards, is closely linked to Leydig cell activity (the cells where steroidogenesis occurs) throughout the reproductive cycle, but testosterone action is related to androgen receptors (ARs) distribution in the seminiferous epithelium. In temperate zones, environmental factors detected through the hypothalamic-pituitary-gonadal axis, downregulate plasma testosterone, resulting in a seasonal reproductive cycle. The aim of this work is to study plasma testosterone in adult male lizards of Liolaemus cuyanus, an oviparous species, throughout its reproductive cycle and its relationship with Leydig cell histology, TotalLeydigCell/ActiveLeydigCell (TLC/ALC) ratio, environmental factors (temperature, relative humidity and solar irradiation) and ARs distribution in seminiferous epithelium. Specimens (N = 27) were captured (October to March) in a semi-arid zone (Valle de Matagusanos, San Juan, Argentina) and grouped into three relevant reproductive periods: pre-reproductive (PrR), reproductive (R), and post-reproductive (PsR). Significant differences in plasma testosterone were found among these periods, highest during R than in PsR. A significant positive correlation between plasma testosterone and TLC/ALC ratio was also observed. Plasma testosterone has a significant positive correlation only with solar irradiation, but not with the other variables. In PrR and R, ARs distribution was cytoplasmic and nuclear, shifting to only cytoplasmic in PsR. These results highlight the close correspondence between plasma testosterone, Leydig cell histology and activity, environmental factors, and ARs distribution, resulting in a synchronization that allows males of L. cuyanus to coordinate their reproductive cycle with the most favorable environmental conditions, probably for mating and birth of offspring.

Preventive Conservation of a Short Theatre Skit (Valencian "Sainete") with Cloud Data Storage and Internet of Things.

Preventing the progressive deterioration of works of art over time is a topic of great interest to collectors and museums. With this aim, time capsules where environmental conditions remain unchanged are well known for preserving art. In this paper, a prototype of an IoT time capsule is presented with a focus on low cost in order to make it accessible to private collectors or small museums with tight budgets. Valencian 'sainetes' (small plays), which are considered materials of artistic interest, have been placed in a "time capsule", which is a manually made container with insulating materials for keeping small pieces for a long time. Environmental control has been performed with a low-cost microcontroller, sensors and actuators connected to a free online IoT platform. This platform recorded data and made decisions based on these data, sending cooling or heating orders to an environmental control system. The results obtained are very satisfactory and open interesting perspectives for future research. However, they also highlight some relevant technical and economic limitations that will have to be considered in the future.

Evaluación del Rendimiento y Producción de Humedad de los Humidificadores de Burbuja usados con Mascarillas Oxígeno de Concentración Variable / Evaluation of the Performance and Humidity Production of Bubble Humidifiers used with Variable Concentration Oxygen Masks

Introducción. Introducción. El uso de humidificadores de burbuja asociados a equipos de oxigenoterapia es una práctica común en los centros hospitalarios de nuestro país. Sin embargo, no se ha evaluado el aporte real de humedad que entregan estos equipos cuando son usados con sistemas de concentración variable a distintas concentraciones de oxígeno. Además, se han descrito problemas de funcionamiento en la entrega de oxígeno cuando se han ocupado este tipo de humidificador. Objetivo. Determinar el aporte real de humedad que entregan los humidificadores de burbuja al ser usados con sistemas de oxigenoterapia de concentración variable. Métodos. Se evaluaron 10 humidificadores de burbuja, marca Hudson RCI®, con válvula liberadora de presión, los cuales se conectaron a un sistema de oxigenoterapia de concentración variable (Marca Hudson RCI®, modelo MULTI-VENT). La medición de la humedad relativa (HR) se realizó en una cámara de acrílico, donde se conectó el inyector del sistema de oxigenoterapia. Para medir H.R. y temperatura se utilizó un higrómetro digital (Veto®, Italia) y un higrómetro análogo (Hygromat®, Alemania). Cada medición requirió un tiempo de 5 minutos para lograr un valor estable. Se realizaron mediciones de la humedad relativa y temperatura entregada por este sistema, con y sin humidificador, a concentraciones de oxígeno de 0.24, 0.26, 0.28, 0.3, 0.35, 0.4 y 0.5. Resultados. Para las la temperatura, no hubo diferencias entre las mediciones realizadas con y sin humidificador de burbuja. Para la humedad relativa, sólo hubo diferencias estadísticamente significativas a concentraciones de oxígeno altas (> 0.35), pero con escaso cambio en la entrega de humedad absoluta. Cuando se utilizó flujos operativos ≥ 6 L/min se activó la válvula liberadora de presión del humidificador. Conclusión. El uso de humidificadores de burbuja asociados a sistemas de oxigenoterapia de concentración variable no genera un aumento significativo de la humedad entregada a concentraciones bajas de oxigeno, por lo cual se podría prescindir de su uso.

Background. The use of bubble humidifiers associated with oxygen therapy equipment is a common practice in hospitals in our country. However, the real contribution of humidity delivered by these equipments when used with variable concentration systems at different oxygen concentrations has not been evaluated. In addition, operating problems have been described in the delivery of oxygen when this type of humidifier has been used. Objetive. Determine the real contribution of humidity delivered by bubble humidifiers when used with variable concentration oxygen therapy systems. Methods. 10 Hudson RCI® brand bubble humidifiers with a pressure release valve were evaluated, which were connected to a variable concentration oxygen therapy system (Hudson RCI® brand, MULTI-VENT model). The relative humidity (RH) was measured in an acrylic chamber, where the injector of the oxygen therapy system was connected. To measure R.H. and temperature, a digital hygrometer (Veto®, Italy) and an analog hygrometer (Hygromat®, Germany) were used. Each measurement required a time of 5 minutes to achieve a stable value. Measurements of the relative humidity and temperature delivered by this system were made, with and without a humidifier, at oxygen concentrations of 0.24, 0.26, 0.28, 0.3, 0.35, 0.4 and 0.5. Results. For temperature, there were no differences between the measurements made with and without a bubble humidifier. For relative humidity, there were only statistically significant differences at high oxygen concentrations (> 0.35), but with little change in absolute humidity delivery. When operating flows ≥ 6 L/min were used, the humidifier pressure relief valve was activated. Conclusion. The use of bubble humidifiers associated with variable concentration oxygen therapy systems does not generate a significant increase in the humidity delivered at low oxygen concentrations, so their use could be dispensed with.

Effects of air pollution and weather on the initial COVID-19 outbreaks in United States, Italy, Spain, and China: A comparative study.

Contrasting effects have been identified in association of weather (temperature and humidity) and pollutant gases with COVID-19 infection, which could be derived from the influence of lockdowns and season change. The influence of pollutant gases and climate during the initial phases of the pandemic, before the closures and the change of season in the northern hemisphere, is unknown. Here, we used a spatial-temporal Bayesian zero-inflated-Poisson model to test for short-term associations of weather and pollutant gases with the relative risk of COVID-19 disease in China (first outbreak) and the countries with more cases during the initial pandemic (the United States, Spain and Italy), considering also the effects of season and lockdown. We found contrasting association between pollutant gases and COVID-19 risk in the United States, Italy, and Spain, while in China it was negatively associated (except for SO2 ). COVID-19 risk was positively associated with specific humidity in all countries, while temperature presented a negative effect. Our findings showed that short-term associations of air pollutants with COVID-19 infection vary strongly between countries, while generalized effects of temperature (negative) and humidity (positive) with COVID-19 was found. Our results show novel information about the influence of pollution and weather on the initial outbreaks, which contribute to unravel the mechanisms during the beginning of the pandemic.

Estimating the relationship of sugarcane borer larvae and crop damage based on adult captures and climate variables

ABSTRACT: Sugarcane borer Diatraea saccharalis (F.) is the primary sugarcane pest in Brazil. To estimate the relationship between larvae in sugarcane stalks and captures of male adults of D. saccharalis, we collected samples weekly: (1) adults with one delta trap with three virgin females and three female pupae and (2) larvae in 120 stalks per plot of 12.6 hectares (355 × 355 m). The study was conducted in two sites with five plots each, in the municipalities of Nova Ponte and Tupaciguara, Minas Gerais State, Brazil, from July 2016 to May 2017. Relationships between (1) males trapped per week and the number of larvae outside of stalks (LOS) were estimated and (2) we evaluated climate variables, namely average temperature, average relative air humidity, hours with relative air humidity below 30 %, rainfall and number of rainy days, and adults and larvae of D. saccharalis. We obtained generalized linear models for LOS in autumn and for larvae inside the stalks (LIS) in spring and autumn and trapped males in both sites. A significant and direct relationship between LIS and males trapped allows predicting larvae density based on captures of males. In addition, plant damage can be estimated based on accumulated captures of males. There was a negative relationship between hours of air humidity < 30 % and larvae outside of stalks. Densities of LIS can be estimated from male captures and by the humidity variables in the trapping week. Nevertheless, the models require validation in the field.

Incidencia de la humedad relativa en la transmisión de la COVID-19 / Impact of relative humidity on COVID-19 transmission

Introducción: El nuevo patógeno SARS-CoV-2 presenta una rápida propagación, y es el causante de la enfermedad del Coronavirus 2019 (COVID-19). Dado que este virus es reciente, el aumento de los casos de la enfermedad COVID-19 ha sido una gran amenaza, a lo que le ha sumado la no existencia de información contundente sobre la enfermedad, su transmisión, y su relación con las distintas variables ambientales. Objetivo: Determinar la incidencia de la humedad relativa en la transmisión de la COVID-19 en las regiones tropicales de Colombia. Métodos: Se analizaron los datos de humedad relativa y número de contagios diarios de COVID-19 de siete ciudades de Colombia ubicadas en la Región Caribe (Barranquilla y Sincelejo), Región Andina (Medellín, Bucaramanga, Armenia y Cúcuta), además de la Región Amazónica (Leticia). Se utilizó un modelo logístico generalizado para analizar los datos existentes y diseñar las curvas epidemiológicas. Resultados: Para todas las ciudades, de acuerdo con el modelo se encontraron altas correlaciones entre la humedad relativa (variable observada) y COVID-19 (variable predicha) con un R2 > 0,90. No obstante, se determinó si existía asociación entre las variables comparando el valor p con el nivel de significancia α del 0,05, se encontró una asociación estadísticamente significativa en las ciudades de Leticia, Barranquilla y Cúcuta. Conclusiones: Los resultados indican que existe una relación directa entre la humedad relativa y la transmisión de COVID 19 en regiones tropicales de Colombia. De ahí que se plantee que el estudio aporta una herramienta importante para la toma de decisiones de las instituciones a cargo del control de la enfermedad, como los gobiernos nacionales y locales(AU)

Introduction: The new pathogen SARS-CoV-2 presents a rapid spread, and is the cause of the Coronavirus disease 2019 (COVID-19). Given that this virus is recent, the increase in cases of the COVID-19 disease has been a great threat, to which has been added the lack of conclusive information about the disease, its transmission, and its relationship with the different environmental variables. Objective: To determine the incidence of relative humidity in the transmission of COVID-19 in the tropical regions of Colombia. Methods: Relative humidity data and number of daily COVID-19 infections from seven cities in Colombia located in the Caribbean Region (Barranquilla and Sincelejo), Andean region (Medellín, Bucaramanga, Armenia and Cúcuta), as well as the Amazon Region (Leticia) were analyzed. A generalized logistic model was used to analyze existing data and design epidemiological curves. Results: For all cities, according to the model, high correlations were found between relative humidity (observed variable) and COVID-19 (predicted variable) with an R2 > 0.90. However, it was determined if there was an association between the variables by comparing the p-value with the level of significance α 0.05, a statistically significant association was found in the cities of Leticia, Barranquilla and Cúcuta. Conclusions: The results indicate that there is a direct relationship between relative humidity and the transmission of COVID 19 in tropical regions of Colombia. Hence, it is proposed that the study provides an important tool for the decision-making of the institutions in charge of the control of the disease, such as national and local governments(AU)

Relationship between temperature and relative humidity on initial spread of COVID-19 cases and related deaths in Brazil.

INTRODUCTION: Climate conditions may influence the transmission of COVID-19. Thus, the aim of this study was to evaluate the impact of temperature and relative humidity on COVID-19 cases and related deaths during the initial phase of the epidemic in Brazil. METHODOLOGY: An ecological study based on secondary data was conducted. Daily data on new COVID-19 cases, deaths, and climate indicators were collected from February 20 to April 18, 2020 (n = 59 days) for all state capital cities in Brazil and the Federal District (Brasília). The climate indicators included mean temperature, temperature amplitude, mean relative humidity, relative humidity amplitude, and percentage of days with mean relative humidity ≤ 65 %. Correlation and multiple linear regression analyses were performed for all cities and stratified by quintiles of the COVID-19 incidence rate. RESULTS: The mean daily temperature was positively correlated with the number of days until the first COVID-19 case was reported. A lower mean relative humidity was correlated with a lower number of cases and deaths in Brazil, especially when the relative humidity was ≤ 65 %. Higher temperatures and humidity amplitudes were correlated with lower COVID-19 mortality. Additionally, after controlling for humidity, cumulative cases of COVID-19 were inversely associated with temperature in cities with mean temperatures less than 25.8 °C. CONCLUSIONS: Variations in temperature and humidity across the Brazilian territory may have influenced the spread of the novel coronavirus during the initial phase of the epidemic.

Effect of the Rural and Urban Microclimate on Mosquito Richness and Abundance in Yucatan State, Mexico.

The objective of this study was to analyze the effect of the rural and urban microclimate on the presence of mosquitoes. Temperature (T) and relative humidity (RH; indoors and outdoors), as well as mosquito richness and abundance were measured in two sites (urban and rural) of the Yucatan State, Mexico. Species richness was higher in the urban site, whereas mosquito abundance was higher in the rural site. The microclimates of urban and rural housing differently affect mosquito richness and abundance. Mosquito richness and abundance were higher outdoors than indoors in the urban site, but they were higher indoors than outdoors in the rural site. For the urban site, analysis of the relation of T and RH with the registered parameters revealed that species richness increased with increasing indoor RH, and that mosquito abundance increased with increasing indoor T and RH. In the rural site, species richness was not affected, but abundance increased with increasing T and RH (indoors as well as outdoors). Results are discussed in the context of the management of mosquito transmitted diseases. No IRB approval was necessary since no ethical implications were identified to be reviewed by the ethical committee for the research of the ECOSUR Institution.

Survival Analysis to Predict How Color Influences the Shelf Life of Strawberry Leather.

Color change of fruit-based products during storage is an important quality parameter to determine their shelf life. In this study, a combination of relative humidity (RH) and illumination was evaluated on the stability of strawberry leathers. Samples were conditioned at 25 °C, in chambers with RH of 22.5% and 52.3% and under two levels of illumination (no illumination and with a light-emitting diode (LED) illumination at 1010 lx). Samples were analyzed during storage by instrumental color measurements, total anthocyanin content, and consumers' acceptance/rejection of the product color. Current-status survival analysis was performed to estimate the sensory-based shelf-life of the strawberry leather. The chromatic parameters (a* and ΔE* values) and anthocyanin content changed with increasing storage time and RH, fitting a first-order fractional conversion model. Samples conditioned at the higher RH showed a higher reduction of a* values and anthocyanins losses when stored under LED illumination than those without illumination. The increase of RH resulted in a faster increase of the consumer rejection probability and a shorter shelf life of the strawberry leather. For 50% of consumers' rejection, the sensory shelf life of the strawberry leather equilibrated at 22.5% RH was estimated as at least 54 days, while it was reduced to approximately 2 days at 52.3% RH. The red chromatic parameter (a* value) strongly correlated to the percentage of consumer rejection in all storage conditions, suggesting that this analytical parameter can be useful as a predictor of strawberry leather's shelf life. Therefore, the results of this study show the applicability of an approach that integrates instrumental and sensory data to acquire faster information on color changes during the storage of strawberry leather and product shelf-life prediction.

Leaf-cutting ants' critical and voluntary thermal limits show complex responses to size, heating rates, hydration level, and humidity.

Thermal variation has complex effects on organisms and they respond to these effects through combined behavioral and physiological mechanisms. However, it is less clear how these traits combine in response to changes in body condition (e.g., size, hydration) and environmental factors that surround the heating process (e.g., relative humidity, start temperatures, heating rates). We tested whether these body conditions and environmental factors influence sequentially measured Voluntary Thermal Maxima (VTmax) and Critical Thermal Maxima, (CTmax) in leaf-cutting ants (Atta sexdens rubropilosa, Forel, 1908). VTmax and CTmax reacted differently to changes in body size and relative humidity, but exhibited similar responses to hydration level, start temperature, and heating rate. Strikingly, the VTmax of average-sized workers was closer to their CTmax than the VTmax of their smaller and bigger sisters, suggesting foragers maintain normal behavior at higher temperatures than sister ants that usually perform tasks within the colony. Previous experiments based on hot plate designs might overestimate ants' CTmax. VTmax and CTmax may respond concomitantly or not to temperature rises, depending on body condition and environmental factors.

A Heuristic and Data Mining Model for Predicting Broiler House Environment Suitability.

The proper combination of environment and flock-based variables plays a critical role in broiler production. However, the housing environment control is mainly focused on temperature monitoring during the broiler growth process. The present study developed a novel predictive model to predict the broiler (Gallus gallus domesticus) rearing conditions' suitability using a data-mining process centered on flock-based and environmental variables. Data were recorded inside four commercial controlled environment broiler houses. The data analysis was conducted in three steps. First, we performed an exploratory and descriptive analysis of the environmental data. In the second step, we labeled the target variable that led to a specific broiler-rearing scenario depending on the age of the birds, the environmental dry-bulb temperature and relative humidity, the ammonia concentration, and the ventilation rate. The output (final rearing condition) was discretized into four categories ('Excellent', 'Good', 'Moderate', and 'Inappropriate'). In the third step, we used the dataset to develop tree models using the data-mining process. The random-tree model only presented accuracy for predicting the 'Excellent' and 'Moderate' rearing conditions. The decision-tree model had high accuracy and indicated that broiler age, relative humidity, and ammonia concentration play a critical role in proper rearing conditions. Using a large amount of data allows the data-mining approach to building up 'if-then' rules that indicate suitable environmental control decision-making by broiler farmers.

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.

Relative Humidity Predicts Day-to-Day Variations in COVID-19 Cases in the City of Buenos Aires.

Possible links between the transmission of COVID-19 and meteorology have been investigated by comparing positive cases across geographical regions or seasons. Little is known, however, about the degree to which environmental conditions modulate the daily dynamics of COVID-19 spread at a given location. One reason for this is that individual waves of the disease typically rise and decay too sharply, making it hard to isolate the contribution of meteorological cycles. To overcome this shortage, we here present a case study of the first wave of the outbreak in the city of Buenos Aires, which had a slow evolution of the caseload extending along most of 2020. We found that humidity plays a prominent role in modulating the variation of COVID-19 positive cases through a negative-slope linear relationship, with an optimal lag of 9 days between the meteorological observation and the positive case report. This relationship is specific to winter months, when relative humidity predicts up to half of the variance in positive case count. Our results provide a tool to anticipate possible local surges in COVID-19 cases after events of low humidity. More generally, they add to accumulating evidence pointing to dry air as a facilitator of COVID-19 transmission.

Principal component regression analysis demonstrates the collinearity-free effect of sub estimated climatic variables on tree growth in the central Amazon / El análisis de regresión por componentes principales muestra el efecto libre de colinealidad de variables climáticas subestimadas sobre el crecimiento de los árboles en la Amazonía central

Abstract Introduction: Climatic variables show a seasonal pattern in the central Amazon, but the intra-annual variability effect on tree growth is still unclear. For variables such as relative humidity (RH) and air vapor pressure deficit (VPD), whose individual effects on tree growth can be underestimated, we hypothesize that such influences can be detected by removing the effect of collinearity between regressors. Objective: This study aimed to determine the collinearity-free effect of climatic variability on tree growth in the central Amazon. Methods: Monthly radial growth was measured in 325 trees from January 2013 to December 2017. Irradiance, air temperature, rainfall, RH, and VPD data were also recorded. Principal Component Regression was used to assess the effect of micrometeorological variability on tree growth over time. For comparison, standard Multiple Linear Regression (MLR) was also used for data analysis. Results: Tree growth increased with increasing rainfall and relative humidity, but it decreased with rising maximum VPD, irradiance, and maximum temperature. Therefore, trees grew more slowly during the dry season, when irradiance, temperature and VPD were higher. Micrometeorological variability did not affect tree growth when MLR was applied. These findings indicate that ignoring the correlation between climatic variables can lead to imprecise results. Conclusions: A novelty of this study is to demonstrate the orthogonal effect of maximum VPD and minimum relative humidity on tree growth.

Resumen Introducción: Las variables climáticas muestran un patrón estacional en la Amazonía central, pero el efecto de la variabilidad intra-anual en el crecimiento de los árboles aún no está claro. Para variables como la humedad relativa (HR) y el déficit de presión de vapor (VPD), cuyo efecto individual en el crecimiento de los árboles puede ser subestimada, planteamos la hipótesis de que tales influencias pueden detectarse eliminando el efecto de colinealidad entre regresores. Objetivo: Este estudio tuvo como objetivo determinar el efecto libre de colinealidad de la variabilidad climática sobre el crecimiento de los árboles en la Amazonía central. Métodos: Se midió el crecimiento radial mensual en 325 árboles desde enero 2013 hasta diciembre 2017. También se registraron datos de irradiancia (PAR), temperatura del aire, lluvia, humedad relativa (RH) y déficit de presión de vapor de aire (VPD). Se utilizó la regresión de componentes principales para evaluar el efecto de la variabilidad micrometeorológica a lo largo del tiempo sobre el crecimiento de los árboles. Para comparación, también se utilizó la regresión lineal múltiple (MLR) estándar para el análisis de datos. Resultados: El crecimiento de los árboles incrementó con el aumento de las precipitaciones y la humedad relativa, y disminuyó con el aumento de la VPD máxima, la irradiancia y la temperatura máxima. Por lo tanto, los árboles crecieron más lentamente durante la estación seca, cuando la irradiancia, la temperatura y la VPD eran más altas. La variabilidad micrometeorológica no afectó el crecimiento de los árboles cuando se aplicó MLR. Estos hallazgos indican que ignorar la correlación entre las variables climáticas puede conducir a resultados imprecisos. Conclusiones: Una novedad de este estudio es demostrar el efecto ortogonal del VPD máximo y la humedad relativa mínima sobre el crecimiento de los árboles.

Susceptibility of All Nymphal Stages of Bemisia tabaci Biotype B (Hemiptera: Aleyrodidae) to Three Brazilian Isolates of Cordyceps sp. (Hypocreales: Cordycipitaceae) in a Screenhouse Under Variable Temperature and Moisture Conditions.

The susceptibility of 1st to 4th instars of Bemisia tabaci (Gennadius, 1989) (Hemiptera: Aleyrodidae) to three isolates of Cordyceps sp. (Hypocreales: Cordycipitaceae) was evaluated in screenhouse experiments under variable temperatures and moisture conditions. No differences in susceptibility to the Cordyceps sp. isolates were observed among 1st, 2nd, and 3rd instar nymphs with respect to median lethal time (LT50) values. Confirmed mortalities ranged from 63.7 to 87.8% when the isolates were tested at 5 × 107 conidia mL-1. The 4th instar was the least susceptible to the fungal isolates (≤ 36.6% mortality). However, 60.0 to 99.5% of the adults that emerged from 4th instar nymphs previously treated with the fungus succumbed to the infection. Temperature was more detrimental to Cordyceps sp. virulence towards B. tabaci nymphs than relative humidity (RH). At similar RH, median LT50 for 1st instar (9.4 days) was higher than for 3rd instar (5.3 days) when the fungus was tested at 5 × 107 conidia mL-1; minimal temperatures of ≥ 12.6°C compared to ≥ 17.0°C were registered for experiments with 1st and 3rd instars, respectively. However, temperatures ≥ 35°C for 4 to 6 h daily did not affect the efficacy of the fungus against nymphs. Cordyceps sp. showed high virulence to all life stages of B. tabaci at relatively low RH, and an ability to grow extensively over the leaf surface and to produce high amounts of conidia on infected hosts. These attributes certainly boost its potential as an important pest control component of B. tabaci biotype B, especially for management of populations resistant to synthetic insecticides.

The effects of time and relative humidity on dry-aged beef: Traditional versus special bag.

The objective of this study was to evaluate the effects of relative humidity (RH) and different dry aging methods on the quality of beef. Sixteen loins, from eight carcasses, were used in this experiment. Each pair of loin was cut into eight sections with equal size, which were evenly assigned to eight treatments, by the combination of two dry aging methods (traditional and highly moisture-permeable special bag), two relative humidity (65 and 85% RH) and two aging times (21 and 42 days). At 85% RH, neither special bag nor the traditional dry aging methods were viable, since samples presented high microbiological counts, mucus and bad odor. At 65% RH, Enterobacteriaceae and lactic acid bacteria were not detected in any treatment. The highest aerobic plate count and psychrotrophic count were observed in the samples of the traditional dry-aged process whereas the special bag showed the greatest mold and yeast count. Regarding dry aging in special bag, there was a reduction in the weight loss (P < 0.05) and no change in the physical-chemical characteristics (P > 0.05) compared to traditional dry aging. The values of pH, moisture and Warner-Bratzler shear force were not affected (P > 0.05) by aging method and relative humidity. Thus, the results indicate that high RH should be avoided for both dry aging methods. Furthermore, the special bag dry aging can be considered an alternative to produce dry-aged beef, as it reduces weight losses even at conditions of lower relative humidity.

Association of environmental and meteorological factors on the spread of COVID-19 in Victoria, Mexico, and air quality during the lockdown.

This study aims to analyze the correlation between environmental factors and confirmed cases of COVID-19 pandemic in Victoria, Mexico. The analysis is performed at the micro-level, filtering only confirmed cases of COVID-19 that are located near air quality monitoring stations, within an approximate coverage of 2.5 km, in order to identify a possible specific association between PM2.5, PM10, carbon monoxide (CO), relative humidity, temperature, absolute humidity, and total confirmed cases of COVID-19. The results evidenced that the cases of COVID-19 were very strongly associated with CO concentration. Our results also suggested that particulate matter pollution (PM2.5 and PM10) exposure have a significant correlation for confirmed cases of COVID-19. Furthermore, we studied the changes in air quality during the COVID-19 outbreak by comparing the average concentration of the four weeks before lockdown (February 16 to March 14, 2020) and the following twelve weeks during the partial lockdown (March 15 to June 06, 2020), revealing a very significant decrease of pollutants.