Bioscience Journal
Not a member yet
3143 research outputs found
Sort by
Markers of mitochondrial energy metabolism and their potential relationships with fatigue in human adults: a scoping review
Get PDFThis scoping review aimed to synthesize the best available evidence of the associations between molecular and genetic markers of mitochondrial metabolism and fatigue in human adults. The research question guiding this review was, “Are there potential relationships between mitochondrial metabolism markers and fatigue?” The literature search used three terms (mitochondria; fatigue; energy metabolism), which yielded 263 manuscripts and 22 theses/dissertations. The studies included in the review had to meet three criteria: (1) Include adult participants (≥18 years of age); (2) Show a relationship between mitochondrial energy metabolism and fatigue; (3) Be published in English, Spanish, or Portuguese. Of the 17 articles included for a full-text review, some had a cross-sectional design (6/17, 35%), and more than half (12/17, 70%) were published between 2015 and 2020. The predominant population studied were patients diagnosed with chronic fatigue syndrome (9/17, 53%). Most studies (15/17, 88%) assessed fatigue with validated instruments. Mitochondrial markers associated with fatigue are a) mitochondrial transport pathways and respiratory chain, b) mutations in mitochondrial DNA, and c) energy disorders in cells of the immune system, such as natural killer cells. Mitochondrial metabolic activities, such as the production and transport of ATP, are significant components that may help understand the etiology of fatigue. Future directions should include longitudinal study designs, characterization of fatigue phenotypes, and the identification of markers involved in production and transport pathways. The clinical relevance in this field can lead to interventions targeting mitochondrial markers to reduce or prevent fatigue
Phytosociological survey of weeds in the grapevine
Get PDFViticulture is expanding in the state of Espírito Santo, Brazil. Weed management is essential for the crop, so knowing the floristic composition of weeds in the vineyards makes this practice sustainable. This study aimed to evaluate the floristic composition of weed populations in grape crops in two seasons, considering different altitudes. The experiment was performed in four properties located in Santa Teresa, ES, Brazil, two of which were at altitudes above 500 m of and two below 500 m, in the winter (2018) and summer (2019) seasons. Weeds were identified with the square inventory method. The phytosociological analysis was based on absolute and relative parameters of frequency, density, dominance, importance value index, and relevance index, besides the diversity, evenness, and similarity indices. Fifty species, 41 genera, and 19 families were identified. The most representative families regarding the number of species were Asteraceae, Poaceae, and Malvaceae. In properties with higher altitudes, the species with the highest IVI was Pilea microphylla (L.) Liebm., in both seasons. In properties with lower altitudes, the highest IVI values were found for Malvastrum coromandelianum L. in the winter and Commelina benghalensis and Portulaca oleracea L. in the summer. The areas below 500 m of altitude showed the highest diversity and evenness indices. The proximity between the areas in both regions contributed to the increased similarity index. Altitude and time of the year contribute to the composition of the infesting community
Biophysical characteristics of soybean estimated by remote sensing associated with artificial intelligence
Get PDFThe biophysical characteristics of vegetative canopies, such as biomass, height, and canopy diameter, are of paramount importance for the study of the development and productive behavior of crops. Faced with a scarcity of studies aimed at estimating these parameters, the objective of this study was to evaluate the performance of artificial neural networks (ANNs) applied to Proximal Remote Sensing (PRS) to estimate biophysical characteristics of soybean culture. The data used to train and validate the ANNs came from an experiment composed of 65 plots with 30 x 30 m mesh, its development was carried out in the 2016/2017 crop in the Brazilian agricultural area. The evaluations were carried out at 30, 45, 60, and 75 days after sowing (DAS), monitoring the spatial and temporal variability of the biophysical characteristics of the soybean crop. Vegetation indexes were collected using canopy sensors. The accuracy and precision were determined by the coefficient of determination (R2) and the error of the forecasts by MAPE (Mean Absolute Percentage Error). PRS and ANNs showed high potential for application in agriculture, since they obtained good performance in the estimation of height (R2 = 0.89) and canopy diameter (R2 = 0.96), being fresh biomass (R2 =0.98) and dry biomass (R2 = 0.97) were the best-estimated variables.As características biofísicas dos dosséis vegetativos, como biomassa, altura e diâmetro da copa, são ligadas à eficiência fotossintética e de uso da água, relacionadas ao desenvolvimento e comportamento produtivo dos cultivos. Diante da escassez de trabalhos que visam a estimação dos parâmetros, objetivou-se avaliar o desempenho das redes neurais artificiais (RNAs) aplicada ao Sensoriamento Remoto Proximal (SRP) para estimar características biofísicas da cultura da soja. O SRP e as RNAs apresentaram alto potencial de aplicação na agricultura, uma vez que obtiveram bom desempenho na estimação de altura (R2=0.89) e diâmetro do dossel (R2=0.96), sendo fresca biomassa (R2 = 0,98) e biomassa seca (R2 = 0,97) foram as melhores variáveis estimadas
Blood glucose kinetics during concentric and eccentric muscle contractions
Get PDFStudies comparing the two classes of stimuli (concentric and eccentric) have shown differences in the improvement of cardiovascular, metabolic, and muscle strength gain. This is an experimental, quantitative, and prospective study that aimed to verify the effect of eccentric exercise on glycolytic consumption and kinetics. The blood glucose kinetics of 17 male subjects was evaluated during a treadmill exercise with a 10% declined floor and velocity that required a 60% metabolic activity of VO2max, for 30 minutes. Seventy-two hours later, the same subjects exercised on the treadmill with a 10% inclined floor and 60% VO2max, for 30 minutes. To quantify glucose, blood samples were collected before the exercise, every three minutes along the 30 minutes of physical activity, and five and 10 minutes after finishing the exercise. For the downward slope, there was a homogeneous group behavior for blood glucose dynamics during the exercise, which was characterized by a monotonic decrease of glucose levels until reaching a minimum value at experimental times between 20 and 30 min, followed by a progressive recovery toward initial values. For the acclivity condition, blood glucose dynamics did not follow such a homogeneous behavior. A set of different types of dynamics could be identified. Experimental data showed that the type of dynamics could be predicted, to some extent, by the basal blood glucose level of subjects. The type of floor slope (upward or downward) directly affected glycolytic consumption and kinetics for the individuals analyzed
O papel das enzimas na atividade angiogênica do látex de Hancornia speciosa
No full textThe Hancornia speciosa latex has shown angiogenic activity. Angiogenesis plays a major role in wound healing, and materials that stimulate this process could be used to develop drugs. This study aimed to explain the role of proteins in the H. speciosa serum fraction latex in angiogenesis. Hence, this material was treated with proteinase K and the proteins were inactivated. After protein inactivation, angiogenic activity was assessed with the chick chorioallantoic membrane assay. The result showed that the proteins in the serum fraction are responsible for angiogenic activity. Then, the total protein content in the serum fraction and its enzymatic activity were investigated. The low protein content observed in the H. speciosa serum fraction latex suggests that this biomaterial could be used to develop new drugs with a hypoallergenic response. Despite the low protein content, there was a significant enzymatic activity of at least three enzymes in the serum fraction latex: β-1,3 glucanase, β-glucosidase, and proteases. These enzymes seem to influence the healing process, assisting debridement, extracellular matrix remodeling, and collagen deposition, and decreasing the chances of contamination by microorganisms. In conclusion, the enzymes in the H. speciosa serum latex are associated with the angiogenic activity of this biomaterial and may be used to assist the wound healing process.O látex de Hancornia speciosa possui atividade angiogênica, antiinflamatória e antioxidante. Essas propriedades são desejáveis para medicamentos usados para auxiliar na cicatrização de feridas. A angiogênese, foco desta pesquisa, é uma etapa crucial do processo de cicatrização dos tecidos. O objetivo deste trabalho foi compreender o papel das proteínas da fração soro do látex de H. speciosa na angiogênese. Para isso, esse material foi tratado com proteinase K e as proteínas inativadas. Após a inativação, a atividade angiogênica foi avaliada com o uso do ensaio da membrana corioalantóide de embrião de galinha. Como resultado, foi observado que as proteínas presentes na fração soro são responsáveis pela angiogênese. Como as proteínas mostraram importante papel na angiogênese, foi investigado o teor de proteínas totais presentes na fração soro, bem como sua atividade enzimática. O baixo teor de proteína observado no látex da fração sérica de H. speciosa sugere que esse biomaterial possa ser utilizado para o desenvolvimento de novos medicamentos com resposta hipoalergênica. Apesar do baixo teor de proteína, foi identificada atividade enzimática significativa de pelo menos 3 enzimas na fração sérica do látex: β-1,3 glucanase, β-glucosidase e proteases. Em geral, essas enzimas parecem influenciar o processo de cicatrização, auxiliando no desbridamento, ajudando na remodelação da matriz extracelular e deposição de colágeno, diminuindo as chances de contaminação por microrganismos. Em conclusão, o processo de cicatrização de feridas depende não apenas das células e dos fatores de crescimento disponíveis no tecido, mas também de enzimas do microambiente da matriz extracelular
Spray volumes for agrochemicals applied to soybean and wheat crops
Get PDFThe question of the spray volume for applying agrochemicals to plants has and still demands studies to continuously search for guiding parameters for technicians due to the several variables involving application technology. This experiment aimed to determine the best spray volume for applying pesticides with a boom sprayer to soybean (Glycine max) and wheat (Triticum aestivum) crops. The experiment had a completely randomized blocks design with five treatments and five replications. In soybean (crop year 2011/12), the treatments were the control (no pesticide application) and spray volume applications of 50, 100, 150, and 200 L ha-1. For wheat (crop year 2012), the treatments were the control and spray volumes of 75, 100, 125, and 150 L ha-1. The variables analyzed were the yield components. The study concluded the need for applying foliar fertilizers and performing the chemical control of diseases and pests in soybean and wheat crops. The spray volumes of 50 L ha-1 for soybeans and 75 L ha-1 for wheat were satisfactory for spraying agrochemicals with a ground bar sprayer on plants
The sward height at the early stockpiling period modifies the structural characteristics of marandu palisadegrass under continuous stocking
Get PDFThe control of sward height at the early stockpiling period influences the structural characteristics of stockpiled sward in winter. So, we conducted this work on the Cerrado region of Brazil based on the hypothesis that the reduction of pasture height at the beginning of stockpiling period results in: (i) lower stock of forage mass; and (ii) higher live leaf mass, but lower stem mass in stockpiled pasture during the winter. The treatments were four sward heights (15, 25, 35, and 45 cm) at early stockpiling period of marandu palisadegrass (Brachiaria brizantha syn. Urochloa brizantha cv. Marandu). The experiment was conducted in a completely randomized design, with three replications (paddocks with 800 m²). The stockpiled swards were evaluated during the grazing period in winter on days 7 (beginning), 45 (middle) and 90 (end). The vegetative tiller number (VEGT), live leaf mass (LLM) and leaf area index (LAI) were greater in the 15 cm stockpiled pasture than the other treatments. Greater heights (35 and 45 cm) at stockpiling resulted in greater forage mass than lower heights (15 and 25 cm). The VEGT, LLM, number of reproductive tillers, live stem mass, forage mass and LAI values were higher at the beginning than at the end of the grazing period. Our hypothesis has been proven, so that the reduction of sward height of the marandu palisadegrass at the beginning of the stockpiling period results in lesser forage mass, but with better structural characteristics.O controle da altura do pasto no período inicial de diferimento influencia as características estruturais do pasto no inverno, o que afeta o desempenho dos animais. Assim, realizamos este trabalho na região do Cerrado do Brasil para testar a seguinte hipótese: a redução da altura do pasto no início do período de estocagem resulta em um menor estoque de massa de forragem, no entanto, melhora as características estruturais do pasto armazenado no inverno. Os tratamentos foram quatro alturas de pasto (15, 25, 35 e 45 cm) no início do período de diferimento do capim-marandu (Brachiaria brizantha cv. Marandu). O experimento foi conduzido em delineamento inteiramente casualizado, com três repetições (piquetes com 800 m²). As pastagens armazenadas foram avaliadas durante o período de pastejo no inverno nos dias 7 (início), 45 (meio) e 90 (final). O número de perfilhos vegetativos (VEGT), a massa foliar viva (MFV) e o índice de área foliar (IAF) foram maiores no pasto de 15 cm do que nos demais tratamentos. Maiores alturas (35 e 45 cm) no armazenamento resultaram em maior massa de forragem do que alturas mais baixas (15 e 25 cm). Os valores de VEGT, MFV, número de perfilhos reprodutivos (REPT), massa viva do caule, massa forrageira e IAF foram maiores no início do que no final do pastejo. Nossa hipótese foi comprovada, de modo que a redução da altura da pastagem de capim-marandu no início do período de armazenamento resulta em menor massa de forragem, mas com melhores características estruturais
The use of light-transparent acetate sheet to measure canopy height of marandu palisadegrass: the influence of development stage and sward height
Get PDFThe use of light-transparent acetate sheet (LAS) may generate variations in the height measured in the sward. However, we compared the use or non-use of LAS to measure the average sward height of marandu palisadegrass (Urochloa brizantha syn. Brachiaria brizantha cv. Marandu) pastures. In the first experiment, the methods were applied in pastures with different average heights (15, 25, 35, and 45 cm), managed under continuous stocking with sheep, and with predominance of vegetative tillers. The shorter pastures (15 and 25 cm) had similar heights with or without the use of the LAS. However, in the taller pastures (35 and 45 cm), the use of LAS resulted in lower height values, compared with its absence. In the second experiment, we compared both methods for measuring the height of deferred marandu palisadegrass and fertilized with two nitrogen levels (50 and 200 kg ha-1) and with high presence of reproductive tillers. A completely randomized design with four replicates was adopted. With 200 kg ha-1 of N, the canopy height was greater than when it was fertilized with 50 kg ha-1 of N. With the use of LAS, the height of deferred and reproductive canopy was greater than without it. In a taller marandu palisadegrass pasture with predominance of vegetative tillers, the use of LAS results in smaller height, contrary to what occurs in deferred swards with reproductive tillers.O uso da lâmina de acetato leve e transparente (LALT) pode gerar variações na altura medida no pasto. Assim, comparamos o uso ou não do LALT para medir a altura média do pasto de capim-marandu (Urochloa brizantha syn. Brachiaria brizantha cv. Marandu). No primeiro experimento, os métodos foram empregados em pastos com diferentes alturas médias (15, 25, 35 e 45 cm), manejados sob lotação contínua com ovinos e com predominância de perfilhos vegetativos. Os pastos mais baixos (15 e 25 cm) apresentaram alturas semelhantes, com ou sem o uso da LALT. No entanto, nos pastos mais altos (35 e 45 cm), o uso do LALT resultou em menores valores de altura, em comparação com a sua ausência. No segundo experimento, comparamos os dois métodos para medir a altura do capim-marandu diferido e fertilizado com dois níveis de nitrogênio (50 e 200 kg ha-1) e com alta presença de perfilhos reprodutivos. O delineamento experimental foi o inteiramente casualizado, com quatro repetições. Com 200 kg ha-1 de N, a altura do dossel foi maior do que quando foi fertilizado com 50 kg ha-1 de N. Com o uso de LALT, a altura do dossel diferido e em estádio reprodutivo foi maior do que sem ela. Em pastos de capim-marandu mais altos e com predominância de perfilhos vegetativos, o uso de LALT resulta em menor altura, ao contrário do que ocorre em pastos diferidos e com perfilhos reprodutivos
Influence of spatial variability of soil chemical attributes on the nutritional status and growth of the rubber tree
Get PDFThe productive potential of the rubber tree (Hevea brasiliensis) is dependent on its genetic composition, in addition to edaphoclimatic factors and management practices. However, as soil properties are not homogenous, knowing the spatial variability of soil attributes would be important to increase productivity and reduce production costs. In this context, the objective of this study was to determine the spatial variability of chemical attributes of the soil and its influence on the nutritional status and growth of rubber tree clones. Clones FX 3864, FDR 5788, CDC 312, and RRIM 600 were planted at Jaturnaíba Farm, in the municipality of Silva Jardim, Rio de Janeiro State, Brazil. The sampling sites were distributed at a spacing of 20 × 20 m on the northern and southern sides of the relief. The chemical attributes of the soil (pH, Ca2+, Mg2+, K+, P, Al3+, H+Al, sum of bases, cation exchange capacity, and base saturation) were evaluated at a depth of 0–20 cm in the different clone plantations. Additionally, the N, P, K, Ca, and Mg content as well as trunk circumference and total plant height, were also evaluated. Geostatistics was used to determine the spatial variability of the soil and clone attributes, while Ordinary Kriging was used to draw variability maps of the variables. A difference in the distribution of the variables, which was dependent on the slope of the relief, was detected through the maps. The southern side presented better conditions as some degradation was observed on the northern side. Certain soil characteristics influenced the distribution of the attributes of the planted clones; for example, the low concentration of Ca2+ in the soil caused Ca deficiency in the FX clone on the southern slope, indicating that liming did not supply enough nutrients for this clone. Our results showed that the variability in soil attributes influenced the nutritional status and growth of the rubber tree clones, indicating that variability maps can guide the planting and management of the rubber tree, providing more efficient management.O potencial produtivo da seringueira (Hevea brasiliensis) depende do seu potencial genético aliado aos fatores edafoclimáticos e as práticas de manejo. No entanto, como as propriedades do solo não são homogêneas, o conhecimento da variabilidade espacial dos atributos do solo é importante para aumentar a produtividade e reduzir os custos de produção. Neste contexto, o objetivo deste estudo foi determinar a variabilidade espacial dos atributos químicos do solo e sua influência no estado nutricional e no crescimento de clones de seringueira. Os clones FX 3864, FDR 5788, CDC 312 e RRIM 600 foram plantados na Fazenda Jaturnaíba, no município de Silva Jardim, estado do Rio de Janeiro, Brasil. Os pontos amostrais foram distribuídos com espaçamento de 20 x 20 m em duas faces do relevo, norte e sul. Foram avaliados os atributos químicos do solo (pH, Ca2+, Mg2+, K+, P, Al3+, H+Al, soma de bases, capacidade de troca de cátions e saturação por bases) na profundidade de 0-20 cm nos diferentes plantios dos clones. Foram avaliados os teores de N, P, K, Ca e Mg dos clones, bem como a circunferência do tronco e a altura total das plantas. A geoestatística foi utilizada para a determinação da variabilidade espacial dos atributos do solo e dos clones, em que a Krigagem Ordinária foi utilizada na construção dos mapas de variabilidade das variáveis. Por meio dos mapas foi possível verificar que houve diferença na distribuição das variáveis de acordo com a face do relevo, na qual a face sul apresentou melhores condições, pois foi observado na face norte níveis de degradação. Alguns atributos do solo influenciaram a distribuição dos atributos dos clones implantados, como por exemplo, a baixa concentração de Ca2+ no solo causou uma deficiência de Ca no clone FX na face sul, indicando que a calagem não está sendo suficiente para nutrir esse clone em níveis adequados. Nossos resultados mostraram que a variabilidade dos atributos do solo influenciou o estado nutricional e o crescimento dos clones de seringueira, indicando que os mapas de variabilidade podem orientar o plantio e o manejo da seringueira, proporcionando um manejo mais eficiente
Contribution of the carbonized rice husk added to the substrate in the production of vegetable seedlings
Get PDFThe carbonized rice husk (CRH) is an agro-industrial residue with great potential for use in mixtures with other substrates for the production of vegetable seedlings. Thus, the purpose of this study was to evaluate the effect of the addition of CRH to the commercial substrate for the production of greenhouse seedlings. The evaluated vegetables were lettuce, broccoli and mustard, cultivated in polystyrene foam (Styrofoam®) trays. Five treatments were evaluated: 100% of the commercial substrate (CS); 25% of CRH + 75% of CS; 50% of CRH + 50% of CS; 75% CRH + 25% CS; and 100% CRH, in a completely randomized design with twelve replicates. The substrates were evaluated for their physical and chemical characteristics. The morphometric evaluations were: number of leaves per plant, plant height, shoot fresh matter yield, root length, and shoot and root dry matter yield. The data were submitted to regression analysis, and the homogeneity of the variance between the experiments was confirmed by the Cochran test. With the addition of CRH to the substrate, there was an increase in total porosity and P content and a reduction in density, water holding capacity, cation exchange capacity, electrical conductivity, and N, K, S, Ca and Mg contents. The carbonized rice husk added to the commercial substrate is a viable alternative for the production of lettuce, broccoli and mustard seedlings. The quality of the vegetable seedlings was higher when there was a 25% CRH + 75% CS mixture.A casca de arroz carbonizada (CAC) é um resíduo agroindustrial com grande potencial para uso em misturas com outros substratos para produção de mudas vegetais. Assim, o objetivo deste estudo foi avaliar o efeito da adição de CAC à um substrato comercial para produção de mudas em casa de vegetação. Os vegetais avaliados foram alface, brócolis e mostarda, cultivados em bandejas de isopor (Styrofoam®). Cinco tratamento foram avaliados: 100 % de substrato comercial (SC); 25 % de CAC + 75 % de SC; 50 % de CAC + 50 % de SC; 75 % de CAC e 25 % de SC; e 100 % de CAC, em delineamento inteiramente casualizado com 20 replicatas. Foram avaliadas as características físicas e químicas dos substratos. E avaliações morfométricas das mudas: número de folhas por planta, altura da planta, massa fresca da parte aérea, comprimento de raiz, massa seca da parte aérea e a massa seca da raiz. Os dados foram submetidos à análise de regressão e a homogeneidade de variâncias entre os experimentos foi confirmada pelo teste Cochran. Com a adição de CAC ao substrato, houve um aumento da porosidade total e teor de P e redução da densidade, capacidade de retenção de água, capacidade de troca catiônica, condutividade elétrica e teores de N, K, S, Ca e Mg. A casa de arroz carbonizada adicionada ao substrato comercial é uma alternativa viável para a produção de mudas de alface, brócolis e mostarda. A qualidade das mudas foi maior com a mistura de 25 % de CAC e 75 % de SC