436 research outputs found
Scanning electron microscopy of conidia of tirchoderma stromaticum, a biocontrol agent of witches' broom disease of cocoa
A field emission electron microscope (SEM) was used to study the conidia surface of Trichoderma stromaticum, a biocontrol of witches broom disease of cocoa. Surface features of conidia were difficult distinguish by light microscope. Conidia appeared to be verrugose and minutely roughened, but the nature of the roughening was not easy to discern. It was common to observe sheath-like structures that completely covered groups of conidia, and also details of wide cells that form the pustules
Variabilidade entre isolados de Trichoderma harzianum: I - Aspectos citológicos
This study is based largely on morphological and cultural characters of Tríchoderma harzianum isolates. It were observed the size of phialospores, mycelial growth and sporulation on malt extract agar and nuclei number per phialospores, stained with Giemsa. A x 100 oil immersion len was used in examining and in measuring phialospores. Based on the size of phialospores, it was possible recognize that there is variaton among the wild isolates for the specie T. harzianum. Also, with relation to mycelial growth and sporulation can itself distinguish from one another different pattern. Up to 50% of isolates had maximum growth in 48 hours. The nuclei number of 1 to 3 per phialospore was observed.Objetivou-se neste trabalho estudar a variabilidade de isolados selvagens de Trichoderma harzianum baseado nas características culturais e citológicas. Observaram-se o tamanho dos fialosporos, número de núcleos por fialosporos e crescimento e esporulação em meio de malte-ágar. Pelos resultados aqui encontrados foi possível reconhecer que há variação entre os isolados selvagens da espécie T. harzianum. Com relação ao número de núcleos, verificou-se uma variação de 1 a 3 núcleos por fialosporos. Também observou-se padrões diferenciais de crescimento e morfologia da colônia. Mais de 50% dos isolados atingiram o máximo de crescimento em 48 horas
Resistance reaction of tomato genotypes (Lycopersicum spp.) to Rhizoctonia solani Kuhn
Dada a importância da tomaticultura no Brasil e das enfermidades que atacam esta cultura, da mesma forma que visando futuros estados em programas de melhoramento vegetal para resistência à patógenos, este trabalho teve por objetivos: avaliar o grau de patogenicidade de quatro isolados de Rhizoctonia solani obtidos de plantas doentes de tomateiro (RT), berinjelas (RB1 e RB2) e pimentão (RP), em viveiros, frente a 9 genótipos de tomateiros e avaliar a reação de resistência de 73 genótipos de tomateiros ao R. solani. Nos experimentos utilizou-se solo esterilizado, em condições de casa de vegetação. Para o experimento I, os isolados de R. solani, oriundos das plantas de tomateiro (RT) e berinjela (RB,) foram igualmente mais patogênicos que os isolados de berinjela (RB,) e pimentão (RP), com relação aos 9 genótipos de tomateiro testados. Pode-se dizer que os isolados variaram em graus de agressividade. Quanto às reações de resistência a R. solani, observou-se que os diferentes genótipos não diferiram estatisticamente entre si. Com relação ao experimento II, entre os 73 genótipos de tomateiro (incluindo espécies selvagens, variedades nacionais e introduções), pode-se observar que houve grande variabilidade quanto a reação de resistência a R. solani (isolado do tomateiro - RT), com percentuais de sobrevivência de plantas variando de 91%, para a cultivar Quinck Pick, até 0% de sobrevivência para o genótipo LA-462. Não foi verificada imunidade em nenhum material avaliado e sim níveis de resistência, onde esta, expressa em percentagem de sobrevivência, ocorreu de uma maneira contínua, desde uma reação de suscetibilidade até altos níveis de resistência.The present study was undertaken with the following objectives: 1) to evaluate the level of pathogenicity of four Rhizoctonia solani isolates obtained from diseased tomato plants (RT), from eggplant (RB1 and RB2), and pepper (RP) and tested on 9 tomato genotypes grown in experimental plots; and 2) evaluate the resistance reaction of 73 tomato genotypes to the pathogen. Experiments were performed in greenhouse using sterilized soil. In experiment I, R. solani isolates from RT and RB2 plants were identically more pathogenic RB1 and RP. In experiment II, wide variability in the resistance reaction to R. solani (isolated from a tomato plant - RT) was observed among the 73 tomato genotypes (which included wild species, Brazilian varieties and introduced material), with percentage of plant survival ranging from 91% for the cultivar Quick Pick to 0% for the genotype LA-462. None of the materials tested showed immunity, but different levels of resistance were observed, ranging from susceptibility to high resistance, as expressed by the survival percentages
ANÁLISE DOS PROCESSOS MORFODINÂMICOS NA BACIA HIDROGRÁFICA DO RIO ANINGAS – PIRAMBU/SE
Este artigo apresenta resultados de estudos realizados na bacia do rio Aningas, no município de Pirambu/SE e objetiva analisar a atuação dos processos morfodinâmicos a partir dos pressupostos holístico-sistêmicos, com a identificação de áreas vulneráveis à erosão. A análise permitiu constatar que os processos são comandados principalmente pela ação das águas pluviais e fluviais, condicionados pelas características da topografia, das formações superficiais e da sazonalidade climática
Square to stripe transition and superlattice patterns in vertically oscillated granular layers
We investigated the physical mechanism for the pattern transition from square
lattice to stripes, which appears in vertically oscillating granular layers. We
present a continuum model to show that the transition depends on the
competition between inertial force and local saturation of transport. By
introducing multiple free-flight times, this model further enables us to
analyze the formation of superlattices as well as hexagonal lattice
Adequacies And Inadequacies In The Anthropometric And Dietetic Profiles Of Preschool Children
Nutritional conditions and food patterns in preschool children are elements that emphasise the importance of health monitoring in this period of nutritional transition, both to ensure nutritional adequacy and how much to intervene in identified inadequacies. Hence, it may also constitute a strategy for public programs and school health services to make decisions. Objective: To analyse the anthropometric and dietary profiles of pre-schoolers of a pole city in Northeastern Brazil. Methods: This is a cross-sectional evaluative study with 114 children aged 2-5 years, of both genders, in three municipal centres of early childhood education. Anthropometry was used to measure weight and height, and the nutritional condition was assessed using the indexes Height for Age (H/A), Weight for Age (W/A), Weight for Height (W/H) and Body Mass Index for Age (BMI/A) in z-score values with classifications established by the World Health Organization. The food intake record was done by direct weighing of the food menu offered during a week in the three institutions. This procedure allowed for the evaluation of the nutritional composition of menus, from the estimates in percentages, average and standard deviations of total calories, macronutrients (proteins, carbohydrates and lipids) and micronutrients (calcium, iron, vitamins A and C), to the adjustments and comparisons to the reference values of the Recommended Dietary Allowances, National Research Council and the PNAE recommendations, by age stages, in full-time units, 1-3 years, 700 kcal; 4-5 years, 950 kcal (70% coverage prediction of daily nutritional requirements) and the part-time units, these same ranges of age, respectively, 200 and 270 kcal (20% coverage for forecasting nutritional needs daily), considering adequate consumption to that with a variation of up to 10% above or below 100% of these recommendations. Results: Most of the preschool children had adequate nutritional conditions, especially those of full-time units, with relative frequencies (W/A: 94.5%; W/H: 89.5%, BMI/A: 81.7%). There were registered also overweight percentages higher than the deficits, in the indices W/A (22.2%), P/E (33.3%) to municipal early childhood centre CMEI-A girls; the indices W/A, W/H, BMI/A (23.8% each) in CMEI B-boys. In relation to the adequacy of the food profile, there was only convergence between the offer and the recommendation of 70% coverage of the daily energy needs, for pre-schoolers of 4-5 years from the centre of full-time units (mean: 951.2 ± 172.3 kcal). As for nutrients, inadequacies had a trend in the coverage of the daily needs on the menu offered in part-time units. Conclusion: Although most children do not present indicative of nutritional risk, requires attention to food portion that was with inadequacies of nutritional condition, with emphasis on weight surplus, while the readjustments in per capita and in portions of the menu implemented in those locations.26223424
Lysine acetylation regulates the interaction between proteins and membranes
Lysine acetylation regulates the function of soluble proteins in vivo, yet it remains largely unexplored whether lysine acetylation regulates membrane protein function. Here, we use bioinformatics, biophysical analysis of recombinant proteins, live-cell fluorescent imaging and genetic manipulation of Drosophila to explore lysine acetylation in peripheral membrane proteins. Analysis of 50 peripheral membrane proteins harboring BAR, PX, C2, or EHD membrane-binding domains reveals that lysine acetylation predominates in membrane-interaction regions. Acetylation and acetylation-mimicking mutations in three test proteins, amphiphysin, EHD2, and synaptotagmin1, strongly reduce membrane binding affinity, attenuate membrane remodeling in vitro and alter subcellular localization. This effect is likely due to the loss of positive charge, which weakens interactions with negatively charged membranes. In Drosophila, acetylation-mimicking mutations of amphiphysin cause severe disruption of T-tubule organization and yield a flightless phenotype. Our data provide mechanistic insights into how lysine acetylation regulates membrane protein function, potentially impacting a plethora of membrane-related processes
Four-dimensional anti-de Sitter black holes from a three-dimensional perspective: Full complexity
The dimensional reduction of black hole solutions in four-dimensional (4D)
general relativity is performed and new 3D black hole solutions are obtained.
Considering a 4D spacetime with one spacelike Killing vector, it is possible to
split the Einstein-Hilbert-Maxwell action with a cosmological term in terms of
3D quantities. Definitions of quasilocal mass and charges in 3D spacetimes are
reviewed. The analysis is then particularized to the toroidal charged rotating
anti-de Sitter black hole. The reinterpretation of the fields and charges in
terms of a three-dimensional point of view is given in each case, and the
causal structure analyzed.Comment: 26 pages, 1 figure, Uses revtex
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