Seasonality of reproduction in an ever-wet lowland tropical forest in Amazonian Ecuador.

Flowering and fruiting phenology have been infrequently studied in the ever-wet hyperdiverse lowland forests of northwestern equatorial Amazonía. These Neotropical forests are typically called aseasonal with reference to climate because they are ever-wet, and it is often assumed they are also aseasonal with respect to phenology. The physiological limits to plant reproduction imposed by water and light availability are difficult to disentangle in seasonal forests because these variables are often temporally correlated, and both are rarely studied together, challenging our understanding of their relative importance as drivers of reproduction. Here we report on the first long-term study (18 years) of flowering and fruiting phenology in a diverse equatorial forest, Yasuní in eastern Ecuador, and the first to include a full suite of on-site monthly climate data. Using twice monthly censuses of 200 traps and >1000 species, we determined whether reproduction at Yasuní is seasonal at the community and species levels and analyzed the relationships between environmental variables and phenology. We also tested the hypothesis that seasonality in phenology, if present, is driven primarily by irradiance. Both the community- and species-level measures demonstrated strong reproductive seasonality at Yasuní. Flowering peaked in September-November and fruiting peaked in March-April, with a strong annual signal for both phenophases. Irradiance and rainfall were also highly seasonal, even though no month on average experienced drought (a month with <100 mm rainfall). Flowering was positively correlated with current or near-current irradiance, supporting our hypothesis that the extra energy available during the period of peak irradiance drives the seasonality of flowering at Yasuní. As Yasuní is representative of lowland ever-wet equatorial forests of northwestern Amazonía, we expect that reproductive phenology will be strongly seasonal throughout this region.

La fenología de floración y fructificación ha sido poco estudiada en los bosques bajos, lluviosos e hiperdiversos de la Amazonía noroccidental. Estos bosques neotropicales son típicamente llamados no estacionales debido a su clima siempre lluvioso y se asume que son no estacionales con respecto a la fenología. Los límites fisiológicos a la reproducción de las plantas impuestos por la disponibilidad de agua y luz en estos bosques son difíciles de desentrañar debido a que estas variables están a menudo correlacionadas temporalmente y las dos se estudian usualmente por separado, lo que desafía nuestra comprensión de su importancia relativa como desencadenantes de la reproducción. Este es el primer estudio de largo plazo (18 años) de la fenología de floración y fructificación en un bosque hiperdiverso de la Amazonía noroccidental ecuatorial, Yasuní, ubicado al este de Ecuador, y el primero en incluir un completo set de datos climáticos mensuales. Usando censos quincenales de 200 trampas y > 1000 especies, examinamos si la reproducción en Yasuní es estacional a nivel de comunidad y de especies y analizamos las relaciones de las variables ambientales con la fenología. También nos interesaba probar si la estacionalidad en la fenología, en caso de que esté presente está causada por la irradiancia. Tanto a nivel de comunidad como de especies, los datos demuestran una fuerte estacionalidad reproductiva en Yasuní. La floración alcanzó un máximo en septiembre-noviembre y la fructificación alcanzó un máximo en marzo-abril, con una fuerte y consistente señal anual en las dos fenofases. A su vez, la irradiancia y la lluvia fueron también marcadamente estacionales, aunque ningún mes en promedio experimentó sequía (i.e. <100 mm de lluvia). La floración fue positivamente correlacionada con la irradiación, apoyando nuestra hipótesis de que la energía extra disponible durante los periodos de mayor irradiación causa la estacionalidad de la floración en Yasuní. Debido a que Yasuní representa a los bosques ecuatoriales lluviosos de tierras bajas de la Amazonía noroccidental, esperamos que la fenología reproductiva sea fuertemente estacional a lo largo de esta región.

Photodegradation of Rituximab and Critical Evaluation of Its Sensibility to Electromagnetic Radiation.

Rituximab is a monoclonal antibody used in the treatment of lymphoma non-Hodgkin. This mAb is photosensitive as it is administrated to the patient by infusion/perfusion; therefore, photostability is a decisive factor in the efficacy of this biologic. To better understand the photodegradation mechanisms of Rituximab, this biologic was exposed to different irradiance conditions. We show in this study that this mAb photodegrade proportionally to irradiance intensities. The main modifications of Rituximab by irradiance correlate to the increase in aggregates, decrease in its Tm, acidic charge variants, oxidation of the Trp (36) in the heavy chain, and decrease in complement-dependent cytotoxicity (CDC) potency. To understand the relationship between real-life photo-exposition conditions and ICH standardized light tests, a full characterization was set up. Worst photo-stress cases were evaluated, 1 and 2 h under direct sunlight through a window, mimicking the ID65 electromagnetic radiation profile. Our results show that only exposition to direct sun irradiance during 2 h, (≈ 150 kluxes•h), increases critically soluble and insoluble aggregates, diminishing Tm, increasing acidic charge variants, and the photooxidation of the Trp (36) in the heavy chain measured by peptide mapping-RP-UPLC-MS. A decrease in CDC below 80% resulted under this condition, which correlates with physicochemical analyses. While inside light-room exposition (similar to ICH test) and ICH conditions do not have any contribution to the degradation of Rituximab measured by these physicochemical and biological analytical methods. These results indicate that exposition of Rituximab to below ≈ 75 kluxes•h of sun light cannot photodegrade critically this biologic inside of its primary container.

Instantaneous global horizontal irradiance and clearness index data with high temporal resolution for 1016 days.

Global Horizontal Irradiance was measured using a thermopile-type pyranometer during more than three years using a sample time of two seconds, with the purpose of capturing fast transient events of irradiance which are notable in tropical regions as the one where these data were collected: Bogotá, Colombia. The date and time of each measurement were registered along with the irradiance values. In addition, other related quantities were calculated and included for each one of the measurement instants: Optical Air Mass, Zenith angle, Extraterrestrial Solar Irradiance, and Clearness Index. Daily aggregated statistics of irradiance were calculated and are provided here too. Data points corresponding to nights were discarded. The raw data was analyzed to remove incomplete days, to guarantee that daily statistics are accurate and meaningful. After this data cleaning process, 1016 complete days remain, having a total of 21,959,912 data points. These data are useful for studying the effect of irradiance transients over photovoltaic systems, including power electronics, batteries and electric loads; it can also be used in studies about the stability of the radiative regime or the variability of irradiance such as Avila et al. (2019) (where part of these data was effectively used) and other related works cited there.

Experimental Application of Methods to Compute Solar Irradiance and Cell Temperature of Photovoltaic Modules.

solar irradiance and cell temperature are the most significant aspects when assessing the production of a photovoltaic system. To avoid the need of specific sensors for quantifying such parameters, recent literature presents methods to estimate them through electrical measurements, using the photovoltaic module itself as a sensor. This work presents an application of such methods to data recorded using a research platform at University of Corsica, in France. The methods and the platform are briefly presented and the results are shown and discussed in terms of normalized mean absolute errors (nMAE) and root mean square errors (nRMSE) for various irradiance and cell temperature levels. The nMAE (and nRMSE) for solar irradiance are respectively between 3.5% and 3.9% (4.2% and 4.7%). Such errors on computed irradiance are in the same order of magnitude as those found in the literature, with a simple implementation. For cell temperatures estimation, the nMAE and nRMSE were found to be in the range 3.4%-8.2% and 4.3%-10.7%. These results show that using such methods could provide an estimation for the values of irradiance and cell temperature, even if the modules are not new and are not regularly cleaned, but of course not partially shaded.

Effects of shade location and protection from direct solar radiation on the behavior of Holstein cows.

Two trials (E1 and E2) were performed to assess the behavior of eight Holstein dairy cows with 367 ± 58 kg of body weight and 10.52 ± 0.08 kg of milk yield. A 4 × 4 Latin square design (four periods of lactation and four levels of solar blockage) with four paddocks was used. Each paddock contained a wood shading structure covered with a cloth that blocked 30% (T1), 50% (T2), 70% (T3), or 100% (T4) of direct solar radiation. In the first trial (E1) each shade structure was located approximately 40 m from the feeder and water troughs; in the second trial (E2), the distance was reduced to 5 m. Air temperature (TA, °C), relative humidity (RH, %), wind speed (U, ms-1), black globe temperature (TG, K), mean radiant temperature (TMR, K), radiant heat load (RHL, W m-2), and local shortwave radiation (RS, W m-2) were recorded at 15-min intervals from 08:00 to 17:00 h. Four behavioral activities were recorded: grazing, eating at the feed trough, ruminating, and idling. For each of these activities, animal posture (lying or upright) and location (under shade or exposed to sunlight) were recorded. The meteorological conditions showed similar variations from 8:00 to 17:00 h between the two trials. However, the air temperatures in E1 were lower (± 2 °C) than those in E2. In a PCA analysis, the first and the second principal components explained 56.87% and 21.85%, respectively, of the total variation in the behavioral variables. Under the E1 conditions, the animals did not seek shade, whereas in E2, the dairy cows spent 35 ± 5% of their time lying and idling in the shade. At a solar radiation blockage of 100%, cows were in the shade more than 60% of the time due to the intensity of solar radiation, which was 722.19 ± 14.59 W m-2 at 11:45. In a PCA analysis, the first and the second principal components explained 65.18 and 22.3%, respectively, and 87.48% together, of the total variation in the original variables. Consequently, it was possible to develop a shade index (IST) based on the first two components. In E1, animals spent very little time in the shade, spending only 0.15% of total time under the shade, irrespective of blockage. However, E2 cows used shade, reaching almost 80% of time under the shade, at midday, when the blockage was 100%.

A Low-Cost, Stand-Alone Sensory Platform for Monitoring Extreme Solar Overirradiance Events.

In this paper, we present a low-cost, stand-alone sensory platform developed for in situ monitoring of environmental parameters, for use in the Amazon region in the north of Brazil. The mission of the platform is to perform monitoring and identification of overirradiance (solar irradiance > 1000 W/m²) and extreme overirradiance events (solar irradiance > 1300 W/m²) using a photovoltaic based irradiance sensor. The sensory platform was built using the ESP8266 microcontroller, an open embedded computer capable of Wi-Fi communication using the IEEE 802.11 standard, and small photovoltaic modules, air temperature, atmospheric pressure, voltage, and current sensors, enabling the development of a low-cost system (€70/R$350.00 BRL). Calibration and tests were conducted at the Federal University of Pará (UFPA), Belém campus, Pará, where the platform measured an extreme overirradiance of 1321 W/m² at a low-latitude (1 °S) and low altitude (7 m above sea level).

Estimativa da radiação solar global diária em função do potencial de energia solar na superfície do solo

The solar radiation received at the surface of the earth, apart from its relevance to several daily human activities, plays an important role in the growth and development of plants. The aim of the current work was to develop and gauge an estimation model for the evaluation of the global solar radiation flux density as a function of the solar energy potential at soil surface. Radiometric data were collected at Ponta Grossa, PR, Brazil (latitude 25º13' S, longitude 50º03' W, altitude 880 m). Estimated values of solar energy potential obtained as a function of only one measurement taken at solar noon time were confronted with those measured by a Robitzsch bimetalic actinograph, for days that presented insolation ratios higher than 0.85. This data set was submitted to a simple linear regression analysis, having been obtained a good adjustment between observed and calculated values. For the estimation of the coefficients a and b of Angström's equation, the method based on the solar energy potential at soil surface was used for the site under study. The methodology was efficient to assess the coefficients, aiming at the determination of the global solar radiation flux density, whith quickness and simplicity, having also found out that the criterium for the estimation of the solar energy potential is equivalent to that of the classical methodology of Angström. Knowledge of the available solar energy potential and global solar radiation flux density is of great importance for the estimation of the maximum atmospheric evaporative demand, of water consumption by irrigated crops, and also for building solar engineering equipment, such as driers, heaters, solar ovens, refrigerators, etc.

A radiação solar recebida na superfície do solo, além de sua relevância a diversas atividades humanas diárias, desempenha um papel importante no crescimento e desenvolvimento de plantas. Este trabalho teve por objetivo desenvolver e aferir um modelo de estimativa da densidade de fluxo de radiação solar global, em função do potencial de energia solar à superfície, no município de Ponta Grossa, PR, Brasil (latitude 25º13' S, longitude 50º03' W, altitude 880 m). Os valores estimados do potencial de energia solar obtidos em função de apenas uma medida realizada na passagem meridiana do sol foram confrontados com os valores medidos por um actinógrafo de placa bimetálica de Robitzsch para aqueles dias que apresentaram razão de insolação superior a 0,85. Este conjunto de dados foi submetido a uma análise de regressão linear simples, obtendo-se bom ajuste entre valores observados e calculados. Foi utilizado o método baseado no potencial de energia solar à superfície para estimativa dos coeficientes a e b da equação de Angström para a localidade em questão. A metodologia foi eficiente para quantificar a densidade de fluxo de radiação solar global, com rapidez e simplicidade, bem como revelaram que o critério de estimativa do potencial de energia solar gerou valores equivalentes aqueles obtidos pela metodologia clássica de Angström. O conhecimento do potencial de energia solar disponível e da densidade de fluxo de radiação global é de suma importância na estimativa da demanda máxima de evaporação, do consumo hídrico de culturas irrigadas e para o dimensionamento de artifícios de engenharia solar, tais como secadores, aquecedores, fogões solares, refrigeradores etc.

Estimativa da radiação solar global diária em função do potencial de energia solar na superfície do solo

The solar radiation received at the surface of the earth, apart from its relevance to several daily human activities, plays an important role in the growth and development of plants. The aim of the current work was to develop and gauge an estimation model for the evaluation of the global solar radiation flux density as a function of the solar energy potential at soil surface. Radiometric data were collected at Ponta Grossa, PR, Brazil (latitude 25º13' S, longitude 50º03' W, altitude 880 m). Estimated values of solar energy potential obtained as a function of only one measurement taken at solar noon time were confronted with those measured by a Robitzsch bimetalic actinograph, for days that presented insolation ratios higher than 0.85. This data set was submitted to a simple linear regression analysis, having been obtained a good adjustment between observed and calculated values. For the estimation of the coefficients a and b of Angström's equation, the method based on the solar energy potential at soil surface was used for the site under study. The methodology was efficient to assess the coefficients, aiming at the determination of the global solar radiation flux density, whith quickness and simplicity, having also found out that the criterium for the estimation of the solar energy potential is equivalent to that of the classical methodology of Angström. Knowledge of the available solar energy potential and global solar radiation flux density is of great importance for the estimation of the maximum atmospheric evaporative demand, of water consumption by irrigated crops, and also for building solar engineering equipment, such as driers, heaters, solar ovens, refrigerators, etc.

A radiação solar recebida na superfície do solo, além de sua relevância a diversas atividades humanas diárias, desempenha um papel importante no crescimento e desenvolvimento de plantas. Este trabalho teve por objetivo desenvolver e aferir um modelo de estimativa da densidade de fluxo de radiação solar global, em função do potencial de energia solar à superfície, no município de Ponta Grossa, PR, Brasil (latitude 25º13' S, longitude 50º03' W, altitude 880 m). Os valores estimados do potencial de energia solar obtidos em função de apenas uma medida realizada na passagem meridiana do sol foram confrontados com os valores medidos por um actinógrafo de placa bimetálica de Robitzsch para aqueles dias que apresentaram razão de insolação superior a 0,85. Este conjunto de dados foi submetido a uma análise de regressão linear simples, obtendo-se bom ajuste entre valores observados e calculados. Foi utilizado o método baseado no potencial de energia solar à superfície para estimativa dos coeficientes a e b da equação de Angström para a localidade em questão. A metodologia foi eficiente para quantificar a densidade de fluxo de radiação solar global, com rapidez e simplicidade, bem como revelaram que o critério de estimativa do potencial de energia solar gerou valores equivalentes aqueles obtidos pela metodologia clássica de Angström. O conhecimento do potencial de energia solar disponível e da densidade de fluxo de radiação global é de suma importância na estimativa da demanda máxima de evaporação, do consumo hídrico de culturas irrigadas e para o dimensionamento de artifícios de engenharia solar, tais como secadores, aquecedores, fogões solares, refrigeradores etc.