Abstract Soil organic matter is closely linked to the quality of Agroecosystems and directly influences the agricultural production and the environmental conditions. Understanding of soil organic matter dynamics in agroforestry systems requires studies with a temporal focus, since the changes in its chemical composition tend to follow a gradual behavior. The aim of this study was to investigate the dynamics of changes in stocks and chemical composition of soil organic matter under agroforestry, using systems in different stages of vegetation succession. The soil sampling was carried out from trenches, and litter fractions were also sampled. The samples were collected from different layers of the soil profile under the following conditions: Control; agroforestry with 1 year; agroforestry with 3 years; agroforestry with 7 years and Forest in natural regeneration. The following attributes/parameters were determined/calculated: i) C and N contents and stocks and C/N ratio; ii) C and N proportions in soil granulometric fractions and iii) kinetics of organic matter accumulation in soil with the time of systems evolution. The results showed: i) The C/N ratio tended to increase in depth but did not show a clear variation between the systems evaluated; ii) the adoption of successive agroforestry practices has the potential to increase the C and N stocks in soil; iii) the soil organic matter accumulation occurs gradually during the systems evolution and is mainly related to the particulate fraction (> 0.053 mm). conditions focus behavior succession trenches sampled Control year regeneration attributesparameters attributes parameters determined/calculated determinedcalculated determined calculated i CN ii iii showed evaluated > ( 0053 0 053 0.05 mm. mm . mm) 005 05 0.0 00 0.

Resumen Introducción. Los estudios de conocimientos, actitudes y prácticas (CAP) relacionados con la Covid-19 permiten establecer los conceptos erróneos y las prácticas inadecuadas en torno a esta enfermedad, información fundamental para diseñar estrategias eficaces y mejorar el cumplimiento de las medidas de prevención. Objetivo. Establecer los conocimientos, actitudes y prácticas relacionadas con la Covid-19 en pacientes venezolanos cribados en la carpa de triaje del Hospital Universitario de Caracas. Materiales y métodos. Se hizo un estudio transversal en 215 pacientes entre el 25 de abril y el 25 de mayo de 2020, mediante entrevistas personales y utilizando una encuesta sobre conocimientos, actitudes y prácticas. Resultados. La mayoría (53,5 %) de los pacientes encuestados se encontraba asintomática; los encuestados tenían un conocimiento adecuado sobre los síntomas y la transmisión de la enfermedad, sin distinción entre sintomáticos y asintomáticos. La mayoría de ellos indicó estar respetando las prácticas de cuarentena, lavado de manos frecuente y uso de tapabocas en público; sin embargo, el reemplazo diario de los tapabocas de tela fue más frecuente en el grupo de los asintomáticos, en tanto que el reemplazo cada tres días fue más común entre los sintomáticos. Por último, más de la mitad de los participantes admitió haber estado en lugares concurridos, siendo esta práctica más frecuente entre los sintomáticos que entre los asintomáticos. Conclusiones. Este es el primer estudio de conocimientos, actitudes y prácticas sobre la Covid-19 en Venezuela. El conocimiento y las prácticas de los venezolanos podrían mejorar mediante el fortalecimiento de los programas de educación y capacitación. Esta información, obtenida durante la fase inicial de la pandemia en Venezuela, podría contribuir al diseño de estrategias de promoción y prevención de la Covid-19.

Abstract Introduction: The studies on knowledge, attitudes, and practices (KAP) regarding COVID-19 help to identify erroneous concepts and inadequate practices related to the disease. This baseline information is essential to design effective strategies and improve adherence to prevention measures. Objective: To identify the COVID-19-related KAP in Venezuelan patients screened at the Hospital Universitario de Caracas triage tent. Materials and methods: We conducted a cross-sectional study among 215 patients between April 25th and May 25th, 2020, with in-person interviews using a KAP survey. Results: Most surveyed patients (53.5%) were asymptomatic. Most of them, both from the symptomatic and the asymptomatic groups, had adequate knowledge about the symptoms and transmission of the disease and the majority said they were practicing quarantine, frequent handwashing, and the use of face masks in public areas. However, the daily replacement of cloth face masks was more frequent in the asymptomatic group whereas replacement every three days was more frequent in the symptomatic group. Finally, more than half of the participants admitted having been in crowded places, a common practice among the symptomatic compared to the asymptomatic patients. Conclusions: This is the first KAP study in Venezuela about COVID-19. Knowledge and practices among Venezuelans could be improved by strengthening education and training programs. This information from the early phase of the pandemic in Venezuela may contribute to the design of COVID-19 promotion and prevention strategies.

O objetivo deste artigo é analisar as representações sociais em torno aos alimentos produzidos por agricultores familiares em três municípios do Rio Grande do Sul (Brasil), destinados à alimentação escolar. Realizamos uma pesquisa qualitativa, com entrevistas em profundidade com 23 agricultores familiares agroecologistas. Os resultados foram processados através de análise de conteúdo. As representações sociais dos agricultores em relação a um alimento saudável remetem ao não uso de agrotóxicos e que não faça mal a saúde, tanto de quem consome quanto de quem produz. Nesses termos, tais ações podem contribuir com a segurança alimentar e nutricional dos cidadãos.

The objective of this work was to analyze the social representations about food produced by family farmers in the three municipalities of Rio Grande do Sul (Brazil), intended for school meals. We conducted qualitative research with in-depth interviews and twenty-three family farmers. Results were processed through content analysis. Social representations of farmers regarding a healthy food refer to the non-use of pesticides for do not harm the health of both the consumer and the producer. In these terms, such actions can contribute to the food and nutritional security of population.

ABSTRACT Foliar diseases impose severe restrictions on the persistence and productivity of Medicago sativa, both of which may be increased by developing disease resistant and more competitive genotypes that can improve pasture quality. We found Curvularia geniculata as the principal alfalfa foliar pathogen in the Brazilian state of Rio Grande do Sul (RS). Growth chamber experiments evaluated the resistance of alfalfa genotypes ‘E1C4’, ‘CPPSul’, ‘ABT 805’ and ‘CUF-101’ to C. geniculata as compared the control ‘Crioula’ genotype. These genotypes were also evaluated in field trials at a sea level site in Eldorado do Sul in central RS and at two sites £200 m above sea level, one in Bagé municipality in south west RS and the other at a farm near the town of Alto Feliz in north east RS. Plants were spray-inoculated with 1.6 x 106 ml-1 of C. geniculata spores and visually evaluated for leaf damage 14 days later. The C. geniculata infection rates varied from zero to 100%. Alfalfa persistence and forage mean dry mass (DM) production at the Eldorado site were measured during different seasons from November 2013 to January 2015 by calculating the incidence of invasive plants and morphologically separating leaves from stems and calculating both leaf and stem DM. Data were analysed using mixed statistical models. The best results for persistence and forage DM were shown by the ‘CPPSul’ genotypes (DM = 16,600 kg ha-1) and ‘Crioula’ (DM = 15,750 kg ha-1). These two genotypes will be used for subsequent investigations and selection cycles.

CONTEXTUALIZAÇÃO: Sabe-se que o treino excêntrico aumenta a força muscular, promovendo uma maior ativação neural e, portanto, tem sido usado na recuperação do torque extensor. A hipótese deste estudo foi a de que possa existir uma forte correlação entre o torque extensor do joelho e os testes funcionais. OBJETIVOS: Correlacionar o torque extensor do joelho com os testes funcionais de agilidade (corridas) e impulsão (saltos em distância) após o treino isocinético excêntrico de curta duração. MÉTODOS: Vinte homens universitários, ativos e saudáveis (22,5±2,1 anos; 1,72±0,10 m; 67,8±9,5 kg; IMC 22,5±2,0 kg/m²), sem reportar anormalidades ou história de lesão no membro inferior, realizaram avaliação isocinética do torque extensor e flexor do joelho e testes funcionais antes e depois do treino isocinético que consistiu em três séries de 10 CEVM a 30º/s, com 3 minutos de repouso entre as séries, realizado duas vezes por semana, durante seis semanas. RESULTADOS: O torque extensor aumentou (16, 27 e 17%; P<0,01), a razão I/Q diminuiu (10, 20 e 13%; p<0,01) para os modos: isométrico e excêntrico a 30°/s e 120°/s, respectivamente; diminuiu o tempo em dois dos cinco testes de corridas (carioca e pivô diagonal; P<0,01) e aumentou a distância nos testes de saltos tanto para o membro dominante quanto para o não dominante (P<0,01). CONCLUSÕES: Embora o treino excêntrico tenha aumentado o torque dos extensores do joelho, bem como melhorado a maioria dos testes funcionais, a hipótese de uma forte correlação entre essas variáveis não se confirmou. Artigo registrado no Australian New Zealand Clinical Trials Registry (ANZCTR) sob o número 12607000590460.

BACKGROUND: It is well known that eccentric training increases muscle strength and promotes greater neural activation, and therefore has been used in the recovery of knee extensors. The hypothesis of this study was that there would be a strong correlation between knee extensor torque and functional tests. OBJECTIVES: To investigate the relationship between knee extensor peak torque and functional tests of agility (runs) and propulsion (hop for distance) after short-term isokinetic eccentric training. METHODS: Twenty healthy and active male undergraduate students (age 22.5±2.1 years; height 1.72±0.10 m; weight 67.8±9.5 kg; body mass index: 22.5±2.0 kg/m²), with no abnormalities or history of injury of the limbs, performed an isokinetic assessment of the knee extensors and flexors and also functional tests before and after isokinetic training, which consisted of 3 sets of 10 MVECs at 30º/s, with 3 minutes of rest between sets, twice a week for 6 weeks. RESULTS: The eccentric training increased the extensor peak torque (16, 27 and 17%; P<0.01) and decreased the H/Q ratio (10, 20 and 13%; P<0.01) for the isometric and eccentric modes at 30°/s and 120°/s, respectively. It also decreased the time in two of the five agility tests (carioca and pivot diagonal; P<0.01), and increased the distance in the hop tests, for both dominant and non-dominant limbs (P<0.01). CONCLUSIONS: Although the eccentric training led to an increase in extensor peak torques as well as an improvement in most of the functional tests, the hypothesis that a strong correlation would be observed between peak torques and functional tests was not confirmed. Article registered in the Australian New Zealand Clinical Trials Registry (ANZCTR) under the number 12607000590460.