188 research outputs found
Possible effects of silicon on wheat black chaff development
No full textO presente trabalho avaliou o efeito do silício (Si) no desenvolvimento da estria bacteriana do trigo, causada pela bactéria Xanthomonas translucens pv. undulosa (Xtu), e investigou por meio de microscopia e de marcadores bioquímicos mecanismos de defesa possivelmente potencializados pelo elemento Si. Os experimentos foram conduzidos em casa de vegetação em delineamento inteiramente casualizado, com quatro repetições. Plantas de trigo da cultivar BR18 foram cultivadas em vasos plásticos contendo 1 kg de solo, ao qual adicionou-se 0,387 g de carbonato de cálcio p.a. (tratamento sem Si) ou 0,30 g Si kg-1 de solo (tratamento com Si) sob a forma de silicato de cálcio ou volastonita. Os ensaios foram conduzidos em duas etapas. Na primeira, plantas de trigo entre o 37o e o 41o dia após a semeadura (d.a.s) foram inoculadas com suspensão bacteriana (OD540 = 0,05 ou OD540 = 0,1) para avaliar os componentes de resistência período de incubação (PI), período latente (PL), dinâmica populacional da bactéria in planta (DP), extravasamento de eletrólitos (EE) e severidade real da doença. Estes ensaios foram conduzidos duas vezes. Na segunda etapa, plantas de trigo entre o 37o e o 41o d.a.s foram inoculadas com suspensão bacteriana (OD540 = 0,1) para quantificar a atividade enzimática das quitinases (QUI), peroxidases (POX) e polifenoloxidases (PFO). Determinou-se também a concentração dos compostos fenólicos solúveis totais (CFST) e dos derivados da lignina ácido tioglicólico (DLATG). Amostras para a análise microscópica e dos teores foliares de Si e de cálcio foram coletadas em ambas etapas do trabalho. Para os teores foliares de Si e cálcio verificou- se diferença significativa apenas para o fator Si. Plantas supridas ou não com o elemento Si não diferiram estatisticamente quanto aos componentes de resistência PI, PL, DP, EE e severidade. Diferenças significativas e pontuais entre plantas supridas e não supridas com Si foram obtidas na determinação da atividade enzimática das POX, PFO e DLATG. No que diz respeito à determinação das QUI, diferenças estatísticas foram obtidas ao longo de todo o período de avaliação. Neste caso, plantas de trigo não supridas com Si e infectadas pela Xtu foram as que apresentaram maior atividade. Observações ao microscópio eletrônico de varredura revelaram degradação de cutícula e viiicolapso do tecido parênquimático em folhas de trigo infectadas. Estas observações nos permitem concluir que tais danos estruturais ocorreram em função da presença do patógeno Xtu. Mecanismos de resistência potencializados pelo Si não foram observados.The present study evaluated the effects of silicon (Si) on wheat black chaff development, caused by Xanthomonas translucens pv. undulosa (Xtu), and the defense mechanisms enhanced by this element by microscopy and biologic markers. The experiments were conducted in greenhouse in a completely randomized design with four replications. Wheat plants (cultivar BR18) were grown on plastic pots containing 1 kg of soil with the addition of 0.387 g of calcium carbonate (treatment without Si) or 0.3 g Si (treatment with Si) using wollastonite as the source of this element. The essays were conducted in two steps. In the first, wheat plants between 37 and 41 days after seedling (d.a.s) were inoculated with a bacterial suspension (OD540 = 0.05 or OD540 = 0.1) to evaluate the following variables: incubation period (IP), latent period (LP), bacterial population dynamics in plant (BDP), electrolyte leakage (EE) and disease severity. The experiment was conducted once. In the second step, wheat plants between 37 and 41 d.a.s were inoculated with bacterial suspension (OD540 = 0.1) to quantify the activity of the enzymes chitinases (QUI), peroxydases (POX) and polyphenoloxydases (PFO). The concentration of total soluble phenolics (TSP) and lignin thioglycolic acid derivatives (LTAD) were also determined. Samples for microscopic analyses and also for Si and calcium concentration on leaves were collected for both assay steps. Foliar contents only differed significantly for Si variant. The variables IP, LP, BDP, EE, and disease severity did not differ significantly between plants supplied or not with Si. There were significant and punctual differences between plants supplied or not with Si regarding the enzymatic activity of POX, PFO and LTAD. Regarding the QUI activity, there were statistical differences between plants supplied or not with Si throughout the entire evaluation period. In this case, wheat plants not supplied with Si and infected with Xtu showed the highest enzyme activity. Scanning eletron microscopy observations showed cuticle degradation and parenchyma tissue collapse in infected wheat leaf tissues. The observations from this study allowed to conclude that such structural injuries occurred as a result of Xtu infection. Silicon had not a great impact on enhance the mechanisms of resistance examined on this study.Conselho Nacional de Desenvolvimento Científico e Tecnológic
Improved likelihood inference for the shape parameter in Weibull regression
No full textWe obtain adjustments to the profile likelihood function in Weibull regression models with and without censoring. Specifically, we consider two different modified profile likelihoods: (i) the one proposed by Cox and Reid [Cox, D.R. and Reid, N., 1987, Parameter orthogonality and approximate conditional inference. Journal of the Royal Statistical Society B, 49, 1-39.], and (ii) an approximation to the one proposed by Barndorff-Nielsen [Barndorff-Nielsen, O.E., 1983, On a formula for the distribution of the maximum likelihood estimator. Biometrika, 70, 343-365.], the approximation having been obtained using the results by Fraser and Reid [Fraser, D.A.S. and Reid, N., 1995, Ancillaries and third-order significance. Utilitas Mathematica, 47, 33-53.] and by Fraser et al. [Fraser, D.A.S., Reid, N. and Wu, J., 1999, A simple formula for tail probabilities for frequentist and Bayesian inference. Biometrika, 86, 655-661.]. We focus on point estimation and likelihood ratio tests on the shape parameter in the class of Weibull regression models. We derive some distributional properties of the different maximum likelihood estimators and likelihood ratio tests. The numerical evidence presented in the paper favors the approximation to Barndorff-Nielsen`s adjustment.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)CNPqFAPESPFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP
Health-related physical fitness in Brazilian adolescents from a small town of German colonization
No full textAbstractObjectiveTo identify the health-related physical fitness profile of Brazilian adolescents (10–17 years) living in a small town of German colonization and to describe the prevalence of those with low levels of physical fitness according to sex and age.MethodThis is a school-based cross-sectional epidemiological study conducted with all adolescents (10–17 years) enrolled in five public schools of São Bonifácio, Brazil. The study included 277 adolescents (145 boys and 132 girls). The FITNESSGRAM® test battery was applied for the assessment of percent body fat, flexibility, muscle strength/endurance and cardiorespiratory fitness.ResultsHigher mean values of percent body fat and flexibility (p<0.01) were found in girls; boys showed higher means (p<0.01) for pull-up and cardiorespiratory fitness tests. The prevalence of adolescents with low levels of physical fitness was high for percent body fat (boys: 29.3%, girls: 31.8%, p=0.75), flexibility (boys: 26.9%, girls: 54.5%, p<0.01), muscle strength/endurance (curl-up: 37.9% of boys and 45.5% of girls, p=0.25; modified pull-up: 47.6% of boys and 54.5% of girls, p=0.30) and cardiorespiratory fitness (boys: 28.0%, girls: 36.9%, p=0.15). As for the overall physical fitness, 75.7% of boys and 88.9% of girls did not meet the minimum recommended values (p=0.01).ConclusionEffective intervention programs are necessary to promote changes in the health-related physical fitness profile of adolescents from São Bonifácio, Brazil
Avaliação de parâmetros para o monitoramento da interferência de plantas daninhas na cultura de soja (Glycine max L.) Evaluating parameters for monitoring weed interference on soybean (Glycine max L.)
No full textO presente estudo visa fornecer subsídios para o processo de tomada de decisão de controle das plantas daninhas baseado em nível de dano na produtividade de culturas agrícolas. Com o objetivo de avaliar o aproveitamento de parâmetros das plantas e daninhas e das plantas de soja no monitoramento da interferência das plantas daninhas, foi realizado, em Botucatu (SP), um experimento sob condições de campo, com delineamento em blocos casualizados. A cultura foi mantida na presença ou ausência da comunidade vegetal infestante por diferentes períodos . O monitoramento da interferência das plantas daninhas na cultura da soja pode se dar através do acúmulo total de matéria seca da comunidade vegetal infestante e dos seguintes parâmetros de crescimento das plantas de soja: número de folhas trifolioladas, área da lâmina foliar, acúmulo de matéria seca de folhas e total. O acúmulo de matéria seca de cada espécie de planta daninha isoladamente, não foi parâmetros eficiente para determinar-se interferência (competição) na cultura da soja.This research aims to subsidize decision making for weed control based on crop yield threshold. Field experiment was conducted in Botucatu (São Paulo, Brazil), with the objective of evaluating the utilization of soybean and weed parameters for monitoring weed interference on soybean yield. The experiment was delineated in a randomized block design. The crop was kept weedy or weed-free for different periods. Total weed dry matter and soybean parameters, such as number of leaves, leaf area, leaf dry matter and total dry matter, can be used for monitoring weed interference on soybean yield. Dry matter of each species separately, had no importance as a competitive element
Ēngines of Ēternity: An Artistic Inquiry into Space Settlement Ideology Using Rotifer Experiments on Board the ISS
No full textĒngines of Ēternity is a transdisciplinary project that takes the biological phenomena of cloning and DNA repair as metaphorical departure points for an art installation about humanity’s enthrallment with cultural immortality. Cultural immortality has long fascinated humankind, with such diverse examples as Ancient Egypt, the Roman Empire, Hindu kingdoms, and Mayan civilization, all assuming perpetuity through monumental works in art and architecture. This aspiration of cultural immortality is also deeply embedded in the imaginary of space exploration. Space settlements are often presented as the culmination of technological and cultural evolution. However, the quest for cultural immortality is often imbued with conflict because of convictions of superiority and impulses of colonialism, and this will be no different in outer space. Ēngines of Ēternity explores these human tendencies through the lens of the smallest animals on Earth, rotifers. On the surface, rotifers seem an unchanging biological culture, perfected through evolution, cloning itself endlessly, and surviving extreme conditions such as complete drying or freezing. However, during drying and rehydration, genetic material gets broken and repaired again, and in the process, diversity is generated. Moreover, DNA from totally different organisms such as fungi, bacteria and plants were discovered inside the rotifer’s genome. This horizontal gene transfer is another mechanism through which rotifers seek out diversity. In Ēngines of Ēternity it’s precisely this contrast between stasis and flux that is used as a metaphorical device to reflect critically on the aspirations of humankind in space. What concept of culture and identity will we develop in space? Who will have a say in this? And if we end up with a rich diversity of cultures and identities, how will we maintain cohesion? Ēngines of Ēternity is a joint effort between SEADS and the laboratory of Karine Van Doninck (UNamur/ULB). In a series of space biology experiments, rotifers were sent to the ISS in 2019 and 2020. SEADS sent a series of thumb-printed glyphs along with the rotifers. This code formed the algorithmic seed for an evolving artwork. After each space mission genetic data of the rotifers was used to parametrically evolve the art. As such, Ēngines of Ēternity engenders new forms of co-creation between humans, biological organisms, algorithms, and outer space. In this paper, the core concepts of the Ēngines of Ēternity project are presented, together with reflections on transdisciplinary research and the need for a more holistic perspective on our future in outer space.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.System Engineerin
Moderator role of vitamin D concentrations on the association between metabolic syndrome and C-reactive protein among adults
No full textOBJECTIVE:To evaluate the association between MetS, its components and insulin resistance (IR) with 25(OH)D and hsCRP. The moderator role of 25(OH)D in the association of MetS, its diagnostic components and IR with hsCRP were also explored. MATERIALS AND METHODS:A cross-sectional study (2014/2015) with a population-based cohort in Southern Brazil (n = 605). Metabolic syndrome (MetS) diagnosis was defined based on the Joint Interim Statement, while the Homeostasis Model Assessment of insulin resistance (IR) (HOMA-IR) was used for determining IR. Serum concentrations of 25-hydroxy vitamin D [25(OH)D] (ng/mL) and high sensitivity C-reactive protein (hsCRP) (mg/L) were evaluated following standard protocols. 25(OH)D was categorized as sufficiency (>30 ng/mL), insufficiency (20-30 ng/mL) or deficiency (<20 ng/mL) to test its moderator role. Multiple linear regression was used to test the associations. The results were adjusted for possible confounders. RESULTS AND DISCUSSION:Hypertriglyceridemia and IR were associated with lower 25(OH)D concentrations. However, except for systolic blood pressure, other MetS components and IR were associated with higher hsCRP. The association between elevated waist circumference (WC) and hsCRP was moderated by the 25(OH)D concentrations. The hsCRP median concentrations were more than two times higher among those with elevated WC and 25(OH)D insufficiency or deficiency. In this study, inadequate concentrations of 25(OH)D increased the adverse relationship between elevated WC and inflammation. 25(OH)D concentrations could be incorporated into the clinical protocols for monitoring individuals with abdominal obesity to identify those at a higher risk of complications.Angelica Scherlowski Fassula, David Gonzalez-Chica, Marui Corseuil Giehl, Diego Augusto Santos Silva, Francieli Cembranel, Yara Maria Franco Moren
Instrumental para definição de zonas de amortecimento de unidades de conservação: o caso da estação ecológica de Carijós-Ibama, Florianópolis/SC
No full textDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Filosofia e Ciências Humanas. Programa de Pós-Graduação em Geografia.As zonas de amortecimento devem desempenhar papel crucial na manutenção dos processos de desenvolvimento e evolução das espécies abrangidas pelas unidades de conservação. O estudo de caso da Estação Ecológica de Carijós demanda uma abordagem que contemple especificidades da sobreposição de competências sobre sua área de entorno e da crescente pressão da urbanização sobre os remanescentes naturais. Este estudo objetivou a caracterização da paisagem atual e da paisagem prevista por normas de uso e ocupação do solo, quanto aos seus graus de fragmentação da cobertura vegetal "original" e, a comparação entre estas duas situações, de forma a propor-se a delimitação, zoneamento e diretrizes de gestão para esta zona de amortecimento. Com base em ferramentas de Sistemas de Informação Geográfica, utilizou-se para a análise comparativa entre as paisagens estudadas, índices ou métricas da paisagem, destacando as relacionadas com tamanho e forma dos fragmentos. A proposta de zoneamento e diretrizes de gestão foram balizadas pela legislação ambiental estudada e aspectos relacionados com a melhoria da conectividade entre os remanescentes e a mitigação de impactos ambientais das atividades humanas.O uso do solo atual ocupa áreas com restrições previstas pela legislação, causando uma maior fragmentação dos ecossistemas do que deveria. As APPs de margem de rio são as que são relativamente menos respeitadas, dificultando seu importante papel na qualidade ambiental da área de estudo. A quantidade de área urbanizada se constitui em cerca de 70% do que se prevê como áreas urbanizáveis, onde cerca de 15% desta urbanização incide sobre áreas com restrição. Esta situação caracteriza que a ocupação de áreas de preservação não pode ser considerada como um déficit de áreas urbanizáveis. Cerca de 90% das APPs descaracterizadas constituem ambientes não urbanizados, situação que permite medidas de intervenção mais eficientes para a recomposição da cobertura vegetal nativa. A proposta de zoneamento prevê um aumento das APPs definidas pelo município, de maneira a readequar os planos diretores à legislação federal e o contexto de uma unidade de conservação de proteção integral. A definição de zonas de amortecimento através da aplicação de indicadores da legislação ambiental se mostra como uma importante ferramenta para manutenção da conectividade entre esta unidade de conservação e habitats de seu entorno, promovendo o alcance dos seus objetivos de criação. O uso de sistemas de informação geográfica e de ferramentas da ecologia da paisagem, permitiu análises mais contextualizadas para o planejamento da conservação da biodiversidade e do uso e ocupação do solo, devendo otimizar a disponibilidade de recursos financeiros e humanos para o de gestão destas questões. O desenvolvimento de estudos nesta direção aponta para abordagens integradoras da paisagem, permitindo um processo de tomada de decisão melhor contextualizado do que as abordagens temáticas específicas
Stages of behavioral change and positive perception of the environment towards physical activity among urban park users
No full textThe objectives of this study were to identify the stages of behavioral change (SBC) towards physical activity (PA) among users of urban parks, to determine the association between socio-demographic and economic variables of users of urban parks in relation to physical activity (PA), and to analyze environmental indicators of the park perceived positively for PA. A total of 218 users of an urban park, who filled out a questionnaire regarding socio-demographic data, SBC and perception of the existing environment, participated in the study. The most prevalent SBC were maintenance (56.6%) and action (21.1%). Most park users (78.7%) presented an active behavior (maintenance + action) towards PA, with this behavior being prevalent among middle-aged individuals (p<0.05). The beauty and geographic location of the park, technological and architectonic factors, some normative policies (public services to the users’ disposition), and values and attitudes were perceived positively for PA, regardless of whether the users regularly performed PA or not. The study suggests that most public park users present an active behavior towards PA, especially middle-aged individuals. In addition, the perception of environmental indicators is positive among physically inactive and active park users, irrespective of SBC
Baixos níveis de atividade física em servidores públicos do sul do Brasil: associação com fatores sociodemográficos, hipercolesterolemia e diabetes
No full textResumoObjetivoEstimar a prevalência de baixos níveis de atividade física e a associação com fatores sociodemográficos, e a presença isolada e simultânea de hipercolesterolemia e diabetes em servidores de uma universidade pública do estado do Paraná, Brasil.MétodoO estudo é caracterizado como analítico transversal, compreendendo amostra de 345 servidores públicos. O nível de atividade física foi avaliado pelo Questionário Internacional de Atividade Física. Foram coletados dados sociodemográficos (sexo, idade, nível econômico, escolaridade, situação conjugal e jornada de trabalho) e o autorrelato de doenças crônicas não transmissíveis (hipercolesterolemia e diabetes). Utilizou‐se estatística descritiva, teste qui‐quadrado e regressão logística binária bruta e ajustada, para estimar odds ratio e intervalos de confiança de 95% (intervalo de confiança 95%).ResultadosA prevalência de baixos níveis de atividade física foi de 41.86%. Após análise ajustada, os servidores que estudaram mais de doze anos apresentaram maiores chances (Odds Ratio: 1.73; intervalo de confiança 95%: 1.02‐2.95) de serem insuficientemente ativos que aqueles de menor escolaridade. As pessoas que apresentavam simultaneamente hipercolesterolemia e diabetes tiveram maiores chances (Odds Ratio: 5.04; intervalo de confiança 95%: 1.31‐19.25) de serem insuficientemente ativos.ConclusõesOs servidores que apresentaram maiores chances de terem baixos níveis de atividade física foram aqueles com alta escolaridade e com presença simultânea de hipercolesterolemia e diabetes.AbstractObjectiveTo estimate the prevalence of low levels of physical activity and its association with sociodemographic factors and presence of hypercholesterolemia and diabetes among servers of a public university from State of Paraná, Brazil.MethodThe sample consisted of 345 public servants. The level of physical activity was assessed by the International Physical Activity Questionnaire. Socio‐demographic factors (sex, age, economic level, educational level, marital status, and working hours), presence of hypercholesterolemia and diabetes were collected through self‐administered questionnaires. We used descriptive statistics and Chi‐square test and binary logistic regression to estimate odds ratios and 95% confidence intervals.ResultsThe prevalence of low levels of physical activity was 41.86%. After adjusted analysis, the servers with twelve years or more of schooling presented more odds (Odds Ratio: 1.73; 95% confidence intervals: 1.02‐2.95) of being insufficiently active than those with less schooling. People who had both hypercholesterolemia and diabetes had higher odds (Odds Ratio: 5.04, 95% confidence intervals: 1.31‐19.25) of being insufficiently active.ConclusionThe servers were more likely to have low levels of physical activity were those with high education and had concomitant hypercholesterolemia and diabetes
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