126 research outputs found

    Mechanisms and Variability of Glyphosate Resistance in Amaranthus Palmeri and Ipomoea Lacunosa

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    The resistance of Palmer amaranth (PA) and the tolerance (natural resistance) of pitted morningglory (PM) to glyphosate have made these species among the most common and troublesome weeds in the southeastern U.S. since the adoption of glyphosate-resistant (GR) crops. Populations of GR PA (R1 and R2) were identified in Mississippi. The inheritance of glyphosate resistance was examined in reciprocal crosses (RC) between glyphosate-resistant (R) and -susceptible (S) parents (Female-S × Male-R, S/R, and Female-R × Male-S, R/S), and second reciprocal crosses (2RC) (Female-S/R × Male-S/R, S/R//S/R, and Female-R/S × Male-R/S, R/S//R/S). Dose-response assays resulted in 17- to 4old resistance to glyphosate compared with S. Population S accumulated 325- and 8-times more shikimate at the highest glyphosate dose than in R1 and R2, respectively. cDNA sequence analysis of the 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) gene indicated no target site mutation. Genomes of R1, R2, RC, and 2RC contained from 1- to 59old more copies of EPSPS gene than S; EPSPS was highly expressed in R1 and R/S, but was poorly expressed in S, S/R, and R2. EPSPS activity was lower in S and S/R than in R and R/S, glyphosate absent; all were inhibited by glyphosate. Western Blot analysis confirmed an increased EPSPS protein level to EPSPS copy number correlation. Thus, the level of resistance was decidedly influenced by the direction of the cross. R and S female plants were reproductively isolated and seed were still produced, suggesting that PA can produce seed both apomictically and sexually (facultative apomixis). This mode of reproduction determined the low copy number inheritance, as well as guaranteeing the GR trait stability in the R populations. Dose-response assays resulted in 2.6old variability in tolerance to glyphosate between the most tolerant (MT) and the least tolerant (LT) PM populations. The level of tolerance positively correlated with the time of exposure to GR-crop system. Less shikimate was recovered in MT as compared to LT. Levels of aminomethylphosphonic acid (AMPA) were not different between populations and sarcosine was not present in either populations. Consequently, metabolism of glyphosate to AMPA or sarcosine is not a common factor in explaining natural resistance levels

    Síntese do glifosato marcado com nitrogênio-15 e sua eficiência prática

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    Glyphosate is the herbicide with the greatest participation in the world market, and it has been used intensively in agriculture for over 30 years, especially because of its relatively low cost and high effectiveness on different species. This study describes a synthesis method of glyphosate in the form of the isopropylamine salt enriched in the stable nitrogen isotope (15N). The 15N-herbicide synthesis was performed using a phosphomethylation reaction with dialkyl phosphite and 15N-glycine. The tests were conducted at a microscale and equimolar quantities. A 20% yield was obtained at the established conditions. To test the effectiveness of the synthesized glyphosate, an experiment was performed in a growth chamber with the weed Lolium multiflorum (ryegrass), which is mentioned to be effectively controlled as indicated in package inserts ofisopropylamine salt-based products (glyphosate). The experimental design was completely randomized, with four replicates, and treatments consisted of isopropylamine salt sources at the commercial dose recommended for the product (720 g a.i. ha-1). The production of green and dry phytomass of the above-ground part and roots was evaluated 21 days after application (DAA), and the treatment toxicity was evaluated 7, 14, and 21 DAA. The isopropylamine salt sources did not differ, recognizing them as useful isotopic tracers.O glifosato é o herbicida de maior participação no mercado mundial, sendo utilizado intensivamente na agricultura há mais de 30 anos, principalmente devido ao custo relativamente baixo e à alta eficiência sobre diferentes espécies. Descreve-se um método para a síntese do glifosato na forma do sal isopropilamina enriquecido no isótopo estável do nitrogênio (15N). A síntese do herbicida-15N foi realizada utilizando-se da reação de fosfometilação com diaquil fosfito e glicina-15N. Os testes foram realizados em microescala e em quantidades equimolares. Foi possível obter um rendimento de 20%. Para testar a eficiência do glifosato sintetizado, realizou-se experimento em câmara de crescimento com a planta daninha Lolium multiflorum (azevém), a qual é eficazmente controlada segundo à bula dos produtos a base do sal de isopropilamina (glifosato). O delineamento experimental foi inteiramente casualizado, com quatro repetições, sendo os tratamentos provenientes de fontes de sal de isopropilamina na dose comercial recomendada do produto (720 g i.a. ha-1). Avaliou-se a produção de fitomassa fresca e seca, da parte aérea e radicular, aos 21 dias após a aplicação (DAA), e a toxicidade dos tratamentos aos 7, 14 e 21 DAA. As fontes de sal de isopropilamina empregados não diferiram, o que deverá permitir sua utilização como traçador isotópico.FAPES

    Ocular dominance and visual function testing

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    To show the distribution of ocular dominance as measured with sensory and eye sighting methods and its potential relationship with high and low contrast LogMAR visual acuity in presbyopic subjects. Method. Forty-four presbyopes (48.5 ± 3.5 years) participated in this study. Ocular dominance was determined by eye sighting (hole-in-card) and sensorial (+1.50 D lens induced blur) methods. According to the dominance detected with each method (RE: right eye or LE: left eye), patients were classified in dominance type 1 (RE/RE), type 2 (RE/LE), type 3 (LE/RE) and type 4 (LE/LE). Results. Baseline refractive error (MSE) was RE:−0.36 ± 1.67 D and LE:−0.35 ± 1.85 D (P= 0.930). RE was the dominant eye in 61.4% and 70.5% of times as obtained from sensorial and sighting methods, respectively. Most frequent dominance was of type 1 (52.3%), in this case the RE showed statistically significant better distance low contrast LogMAR VA (0.04 LogMAR units) compared to the LE (P < 0.05 ). Conclusions. The dominance was more frequent in RE in this sample. The eye sighting and sensorial methods to define ocular dominance agreed in more than half of cases. Amount of MSE was not significantly different between dominant and non-dominant eye. But in case of right dominance, the RE presented better distance low contrast VA compared to the LE.Purpose. To show the distribution of ocular dominance as measured with sensory and eye sighting methods and its potential relationship with high and low contrast LogMAR visual acuity in presbyopic subjects. Method. Forty-four presbyopes (48.5 +/- 3.5 years) participated in this study. Ocular dominance was determined by eye sighting (hole-in-card) and sensorial (+1.50D lens induced blur) methods. According to the dominance detected with each method (RE: right eye or LE: left eye), patients were classified in dominance type 1 (RE/RE), type 2 (RE/LE), type 3 (LE/RE) and type 4 (LE/LE). Results. Baseline refractive error (MSE) was RE:-0.36 +/- 1.67D and LE:-0.35 +/- 1.85D (P = 0.930). RE was the dominant eye in 61.4% and 70.5% of times as obtained from sensorial and sighting methods, respectively. Most frequent dominance was of type 1 (52.3%), in this case the RE showed statistically significant better distance low contrast LogMAR VA (0.04 LogMAR units) compared to the LE (P < 0.05). Conclusions. The dominance was more frequent in RE in this sample. The eye sighting and sensorial methods to define ocular dominance agreed in more than half of cases. Amount of MSE was not significantly different between dominant and non-dominant eye. But in case of right dominance, the RE presented better distance low contrast VA compared to the LE.Present study has been supported by Fundacao para a Ciencia e Tecnologia (FCT) under Contract PTDC/SAU-BEB/098392/2008. The authors declare that they do not have any proprietary or financial interests in any of the materials mentioned in this paper. The present work has been presented in part at the 8th International Conference of Optometry (CIOCV'2011) at University of Minho (9-10 April, Braga, Portugal)

    ANÁLISE DOS TERMOS “DOR” E “GUAPO” PRESENTES NO ATLAS LINGUÍSTICO GALEGO E SUA VITALIDADE NO TWITTER: UMA PROPOSTA METODOLÓGICA

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    The article aims to present a comparative analysis, with a quantitative and diatopic approach, referring to terms registered in the Galician Linguistic Atlas in relation to those collected on Twitter. Specifically, it is intended to analyze the vitality of the terms contained in the ALGa (volume V), checking if these terms continue to be used to communicate in tweets. To achieve the objective, a specific methodology was determined and tested with the selected data. The results obtained reveal that it is possible to analyze the vitality of some terms, but that some methodological adjustments are made available in order to achieve the objective with the terms of the ALGa.O artigo tem por objetivo apresentar uma análise comparativa, com abordagem quantitativa e diatópica, referente a termos registrados no Atlas Linguístico Galego em relação aos coletados no Twitter. Especificamente, pretende-se analisar a vitalidade dos termos que constam no ALGa (volume V), verificando-se se tais termos continuam sendo utilizados para se comunicar nos tweets. Para concretização do objetivo, desenvolveu-se uma metodologia específica que foi testada com os dados selecionados. Os resultados obtidos revelam que é possível analisar a vitalidade de alguns termos, mas que alguns ajustes metodológicos são necessários a fim de alcançar o objetivo com os termos do ALGa

    Radiometric characterization of a novel LED array system for visual assessment

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    Light that enters the eye can be distorted due to several factors leading to a poor visual performance. The purpose of this paper is to describe and characterize the light-emitting diode (LED) display system to be used in a new device to assess visual quality under high glare conditions. The device has a central white LED and surrounding white LEDs distributed in a radial manner. Each LED is controlled independently using special designed software. The spectral power distribution and color of the LEDs were assessed at different voltage intensities to test the response in terms of output luminance and spectral distribution. It was found that the typical maximum luminance was about 2800 cd/m2 and 6 cd/m2 for the central and surrounding LEDs, respectively. Their color was found to be within the ΔE⁄ ab range of 2.6 and 0.23, respectively, if the minimum and maximum intensities are considered. The characterization of this device was proved successfully, which might indicate its usefulness in future visual assessments.This study has been funded by FEDER through the COMPTETE Program and by the Portuguese Foundation for Science and Technology (FCT) in the framework of projects PTDC/SAU-BEB/098391/2008, PTDC/SAU-BEB/098392/2008 and the Strategic Project PEST-C/FIS/UI607/2011

    Postural control parameters in elderly female fallers and non-fallers diagnosed or not with knee osteoarthritis

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    OBJECTIVES: To compare stabilometric parameters of elderly female fallers and non-fallers associated or not with knee osteoarthritis (OA). METHODS: Fifty-six elderly female fallers and non-fallers diagnosed or not with unilateral or bilateral knee OA were divided into the following groups: FOA (n = 10), elderly female fallers with knee OA; FNOA (n = 11), elderly female fallers without knee OA; NFOA (n = 14), elderly female non-fallers with knee OA; and NFNOA (n = 21), elderly female non-fallers without knee OA. For analyzing semi-static balance on a force platform with the elderly females standing, the following parameters were assessed in four conditions: center of pressure (COP), anterior-posterior and mediolateral displacements (APD and MLD, respectively); and COP anterior-posterior and mediolateral displacement velocities (APV and MLV, respectively). The following conditions were assessed: 1) standing on a firm wooden surface with eyes open (WSEO); 2) standing on a firm wooden surface with eyes closed (WSEC); 3) standing on a foam surface with eyes open (FSEO); 4) standing on a foam surface with eyes closed (FSEC). RESULTS: The elderly females with knee OA showed greater APD in all four conditions assessed (P < 0.05), while the elderly female fallers showed greater MLD (P < 0.05). No difference between the groups was observed for APV and MLV (P &gt; 0.05). CONCLUSIONS: Knee OA per se increases APD of the COP, while the history of falls, regardless of the presence of knee OA, hinders postural control in the ML direction.OBJETIVOS: Comparar parâmetros estabilométricos de mulheres idosas com ou sem histórico de quedas associadas ou não à osteoartrite (OA) de joelhos. MÉTODOS: Cinquenta e seis idosas apresentando ou não histórico de quedas (Q) e OA de joelho unilateral e bilateral foram distribuídas da seguinte maneira: grupo QOA (n = 10), idosas com histórico de queda e OA de joelho; grupo QSOA (n = 11), idosas com histórico de queda e sem OA de joelho; grupo SQOA (n = 14), idosas sem histórico de quedas (SQ) e com OA de joelho; e grupo SQSOA (n = 21), idosas sem histórico de quedas e sem OA de joelho. Para análise do equilíbrio semiestático usando uma plataforma de força, foram avaliados os deslocamentos anteroposterior (DAP) e mediolateral (DML), as velocidades de oscilação anteroposterior (VAP) e mediolateral (VML) em quatro situações na postura ereta. As situações avaliadas foram as seguintes: 1) PFOA: sobre superfície fixa e olhos abertos; 2) PFOF: sobre superfície fixa e olhos fechados; 3) PIOA: sobre superfície instável e olhos abertos; 4) PIOF: sobre superfície instável e os olhos fechados. RESULTADOS: As idosas com OA de joelho apresentaram maior DAP em todas as situações analisadas (P < 0,05), ao passo que idosas com histórico de quedas apresentaram maior DML (P < 0,05). Não houve diferenças entre os grupos para VAP e VML (P &gt; 0,05). CONCLUSÕES: A OA de joelho, por si, é um fator prejudicial no aumento de oscilação do centro de pressão (COP) na direção anteroposterior, enquanto o histórico de quedas, independente da presença de OA de joelhos, traz prejuízos ao controle postural na direção mediolateral.51251

    A transversalidade de Implementação da Supervisão Clínica em Enfermagem

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    A Supervisão Clínica em Enfermagem (SCE) é transversal a todos os contextos cuidativos, desde o. autocuidado, ao risco de queda, passando pelo desenvolvimento de competências parentais, ensino de estudantes e docência. Reconhecer a transversalidade da aplicação da SC em Enfermagem, e a consequente melhoria dos cuidados e da formação dos estudantes. Estudo de revisão sistemática da literatura baseada na estratégia PICO, efetuada em novembro de 2019, , nas bases de dados B-on, Rcaap, Scielo a partir dos descritores “supervisão clínica”, “enfermeiros”, “estudantes de enfermagem” e “enfermagem Selecionados 9 estudos (publicados entre 2014-2018) para análise, de entre 96 encontrados.Emergindo de diferentes áreas de cuidados, verificou-se: Em 100% dos estudos, defende-se que para o sucesso da implementação da SCE, é fundamental a formação do Supervisor e as respetivas competências, A SCE é perspetivada como uma mais-valia na implementação de qualquer processo formativo no ensino clínico, devendo reforçar-se a interação entre as Instituições de Formação e Saúde, Sugere-se o investimento num processo de diagnóstico na planificação dos cuidados. Em 44,4% dos estudos identificaram-se fatores facilitadores e dificultadores, permitindo adotar estratégias para minimizar limitações, Defende-se a necessidade de desenvolver sessões de SC em grupo, para exposição de dúvidas, trocas de experiências e discussão de casos clínicos.info:eu-repo/semantics/publishedVersio

    Analysis of the movement of food bolus : a comparison between a healthy esophagus and a chagasic megaesophagus

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    Objetivo: estudar a dinâmica do comportamento do esôfago humano quando afetado por doença de Chagas e propor um controlador orgânico para auxiliar no aperistaltismo do órgão. Métodos: um modelo de massa, mola e amortecedor foi proposto para modelar o deslocamento do bolo alimentar no esôfago durante a ação peristáltica. Foram utilizados parâmetros da literatura para simular o megaesôfago chagásico e o saudável. Resultados: foram analisadas as curvas de velocidade e deslocamento de ambos os modelos e identificou-se as diferenças dinâmicas entre o órgão saudável e um doente. O deslocamento de alimentos em um tipo de Chagas megaesófago II (3 centímetros de dilatação) é apenas 11,84% do deslocamento num esófago saudável. Conclusão: a doença de chagas gera uma velocidade próxima de zero e um alto amortecimento na curva de descida do alimento que devido ao peristaltismo o deslocamento que não pode retornar ao seu estado inicial, o que comprova a retenção do bolo alimentar. Com o sistema de controle orgânico proposto obteve-se uma aproximação das curvas a um comportamento dinâmico próximo do modelo do órgão saudável, minimizando a retenção do alimento.Objective: to study the dynamics of the human esophagus behavior when affected by Chagas disease. Methods: a mass-spring-damper model was proposed to model the food through the esophagus during peristaltic action. After that, parameters were recalculated to simulate a chagasic megaesophagus. Results: the velocity and displacement curves from both models were analyzed and the dynamic differences between the healthy organ and the ill one, identified. According to the results obtained, the food displacement in a chagasic megaesophagus type II (3 centimeters dilated) is just 11.84% of the displacement in a healthy esophagus. Conclusion: Chagas disease generates a velocity close to zero and a high dampering in the downwards curve of the bolus whose displacement cannot return to its initial state, due to aperistalses, which proves the food bolus retention. With the introduction of the proposed organic control system, an approximation of the curves that remained with dynamic behavior close to the model of the healthy organ was obtained, minimizing the retention of the food
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