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Search Results: 1 - 10 of 53068 matches for " David Rengel "
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Bioavailability of Phosphorus and Micronutrients in the Soil-Plant-Microbe Continuum
Z Rengel
Revista de la Ciencia del Suelo y Nutrición Vegetal , 2008,
The arsenic action during the Bufo arenarum gonad development (Anura: Bufonidae)
Rengel, Dora,Pisanó, Armando
Cuadernos de Herpetología , 1991,
Abstract: Bufo arenarum ovulations have been kept in potassium bibasic arsenate from the fertilization until 26mm larva. The gonad in development, in the presence of the toxic, suffers significant alterations in its volume, shape and structure. It does not have the typical naillike morphology; on the other hand, it is presented as a spherical mass of reduced volume, that has, as demostrated by the histological analysis, very few oocytes or gonia submerged in a very scarce quantity of stroma. The hypothesis of this study was that it would be due to a succession of events whose cause would lie on the damage that the arsenic determine at the somatic layers level.
The W-function applied to the age of Globular Clusters
Miriam Rengel,Gustavo Bruzual
Physics , 2002, DOI: 10.1007/10857603_12
Abstract: We present a statistical approach for estimating the age of Globular Clusters by measurement of the likelihood between the observed cluster sequences in the Colour--Magnitude Diagram and the synthetic cluster sequences computed from stellar evolutionary models. In the conventional isochrone fitting procedure, the age is estimated in a subjective way. Here, we calculate the degree of likelihood by applying a modern statistical estimator, the Saha estimator {\it W}, and the interval of confidence from $\chi^{2}$ statistics. We apply this approach to sets of three different evolutionary models. Each of these sets consists of different chemical abundances, ages, input physics, etc. Based on our approach, we estimate the age of NGC 6397, M92 and M3. With a confidence level of 99%, we find that the best estimate of the age is 14.0 Gyr within the range of 13.8 to 14.4 Gyr for NGC 6397, 14.75 Gyr within the range of 14.50 to 15.40 Gyr for M92, and 16.0 Gyr within the range of 15.9 to 16.3 Gyr for M3.
A new genomic resource dedicated to wood formation in Eucalyptus
David Rengel, Hélène Clemente, Florence Servant, Nathalie Ladouce, Etienne Paux, Patrick Wincker, Arnaud Couloux, Pierre Sivadon, Jacqueline Grima-Pettenati
BMC Plant Biology , 2009, DOI: 10.1186/1471-2229-9-36
Abstract: We report here the normalization and sequencing of a cDNA library from developing Eucalyptus secondary xylem, as well as the construction and sequencing of two subtractive libraries (juvenile versus mature wood and vice versa). A total of 9,222 high quality sequences were collected from about 10,000 cDNA clones. The EST assembly generated a set of 3,857 wood-related unigenes including 2,461 contigs (Cg) and 1,396 singletons (Sg) that we named 'EUCAWOOD'. About 65% of the EUCAWOOD sequences produced matches with poplar, grapevine, Arabidopsis and rice protein sequence databases. BlastX searches of the Uniref100 protein database allowed us to allocate gene ontology (GO) and protein family terms to the EUCAWOOD unigenes. This annotation of the EUCAWOOD set revealed key functional categories involved in xylogenesis. For instance, 422 sequences matched various gene families involved in biosynthesis and assembly of primary and secondary cell walls. Interestingly, 141 sequences were annotated as transcription factors, some of them being orthologs of regulators known to be involved in xylogenesis. The EUCAWOOD dataset was also mined for genomic simple sequence repeat markers, yielding a total of 639 putative microsatellites. Finally, a publicly accessible database was created, supporting multiple queries on the EUCAWOOD dataset.In this work, we have identified a large set of wood-related Eucalyptus unigenes called EUCAWOOD, thus creating a valuable resource for functional genomics studies of wood formation and molecular breeding in this economically important genus. This set of publicly available annotated sequences will be instrumental for candidate gene approaches, custom array development and marker-assisted selection programs aimed at improving and modulating wood properties.Wood is the major component of terrestrial plant biomass and is expected to play a significant role in future sustainable development as a renewable and environmentally acceptable source for fibers,
Necesidad de la adaptación transcultural en las herramientas de valoración enfermeras Ned for cross-cultural adaptations in nursing assessment tools
Cristóbal Rengel Díaz
Index de Enfermería , 2011,
Uso dos Atributos da Contabilidade Gerencial Propostos por Moores e Yuen (2001) em Empresas de um Segmento Industrial de Santa Catarina Use of the Management Accounting Attributes Proposed by Moores and Yuen (2001) in Companies of an Industry in de State of Santa Catarina Uso de los Atributos de la Contabilidad de Gestión Propuestos por Yuen y Moores (2001) en Empresas de un Segmento de la Industria de Santa Catarina
BEUREN, Ilse Maria,RENGEL, Silene
Revista Brasileira de Gest?o de Negócios , 2012,
Abstract: RESUMO O sistema de contabilidade gerencial deve prover os gestores de informa es para o cumprimento de objetivos e metas da organiza o, adaptadas à realidade e estratégias organizacionais. O estudo objetiva averiguar o uso dos atributos da contabilidade gerencial, conforme proposto por Moores e Yuen (2001), nas empresas do segmento industrial de máquinas, aparelhos e materiais elétricos do Estado de Santa Catarina. Pesquisa descritiva realizou-se por meio de levantamento com aplica o de questionário aos gestores das empresas, cujas quest es foram adaptadas de Necyk (2008), fundamentadas na proposi o de Moores e Yuen (2001). A popula o compreende as 264 empresas listadas na Secretaria da Fazenda do Estado de Santa Catarina do referido segmento de atividade econ mica, e a amostra n o aleatória constitui-se das 40 que responderam à pesquisa. Os resultados mostram que os atributos da contabilidade gerencial propostos por Moores e Yuen (2001) em suas duas vertentes s o utilizados nas empresas. O atributo sele o de informa es, que aborda as fontes de informa es utilizadas, obteve concordancia de 57%. O atributo apresenta o de informa es, que aborda formato, tipo e disponibilidade das informa es, obteve concordancia de 64%. Conclui-se que as empresas participantes da pesquisa utilizam tipos de informa es diversificados em maior propor o do que as fontes de informa es, ainda que várias dessas informa es n o estejam sendo apresentadas no formato adequado, podendo prejudicar sua relevancia na tomada de decis es. ABSTRACT The management accounting system should provide to managers the information required to accomplish goals and objectives of the organization, adapted to reality and organizational strategies. The goal of this study is to investigate the use of the management accounting attributes, as proposed by Moores and Yuen (2001), in companies operating in the machinery, electrical equipment and materials industry in the state of Santa Catarina. A descriptive research was conducted through a questionnaire applied to the companies’ managers, having its questions adapted from Necyk (2008) and based on the proposition of Moores and Yuen (2001). The population comprises 264 companies listed on the Financial Department of Santa Catarina State in the referred to economic activity segment, and the non-random sample comprises the 40 survey respondents. The results show that the management accounting attributes proposed by Moores and Yuen (2001) in its two lines of thought are used in those companies. The information selection attribute, which addresses
Proteinases in the joint: clinical relevance of proteinases in joint destruction
Yvonne Rengel, Caroline Ospelt, Steffen Gay
Arthritis Research & Therapy , 2007, DOI: 10.1186/ar2304
Abstract: Proteases are responsible for enzymatic cleavage of peptide bonds [1,2], which is a basic requirement for completion of diverse biological processes. Examples of contributions made by proteases can be found in digestion, blood coagulation and fibrinolysis. They are also involved in the processing of precursors related to the synthesis of collagen, immune functions, development and apoptosis [3]. The proteolytic activity of proteases must be rigorously controlled to avoid inappropriate degradation of proteins. Imbalance in regulation of proteolytic activity can be found in a wide range of diseases, including cancer, rheumatoid arthritis (RA) and osteoarthritis (OA) [4].Of particular importance is that proteases have been found to play diverse and strategic roles in cartilage and bone remodelling, which in recent years has engendered increased interest in these enzymes in the field of rheumatology. To highlight the clinical relevance of proteinases to joint destruction, we discuss their contribution to cartilage and bone homeostasis in health and give particular emphasis to their crucial role in diseases such as RA, OA and spondyloarthritis.Proteases selectively hydrolyze a peptide bond in a polypeptide chain of a target molecule. Depending on the position of the peptide bond, proteases are referred to as exopeptidases or endopeptidases. Exopeptidases specifically cleave substrates at the amino-terminal or carboxyl-terminal positions of polypeptides, and therefore can be subdivided into aminopeptidases and carboxypeptidases [5,6]. Endopeptidases (also called proteinases) break peptide bonds in the middle of the molecule. They can be subclassified based on their mechanism of catalysis, which is related to the chemical group involved in the process of hydrolysis. As a consequence, endopeptidases are described as aspartate, cysteine and threonine types, which act intracellularly in an acid pH, or as serine and metallo catalytic types, which act extracellularly in a neutr
Ciclo de vida organizacional pautado no modelo de Lester, Parnell e Carraher (2003) e na lógica fuzzy: classifica??o de empresas de um segmento industrial de Santa Catarina
Beuren, Ilse Maria;Rengel, Silene;Hein, Nelson;
Revista de Administra??o (S?o Paulo) , 2012, DOI: 10.5700/rausp1034
Abstract: the goal of this study is to identify the stages of the organizational life cycle, based on the model of lester, parnell and carraher (2003), of companies in the industrial sector of electrical materials, devices and machines of the state of santa catarina. the authors conducted a descriptive study using a quantitative approach, also based on a survey that involved submitting company managers to a questionnaire. the population consisted of the 264 companies of the said sector listed with the finance bureau of the state of santa catarina, and a non-random sample of the 40 companies that answered the survey. the identification variables of the lifecycle stages used in the questionnaire were drawn from lester, parnell and carraher (2003). a statistical technique called fuzzy logic was applied to the research data. the research results showed that 57.5% of the companies were in the startup stage, 15% in the growth stage, 7.5% in the maturity stage, 10% in the rejuvenation stage and 10% in the decline stage. the authors concluded that certain stages of the organizational lifecycle are close to each other and that one cannot clearly perceive a deterministic progression in the stages of the lifecycle as a unique, definitive and irreversible sequence, in the traditional biological sense.
Crecimiento y dinámica de acumulación de nutrientes en ca?a de azúcar. I. macronutrientes
Rengel,Marcos; Gil,Fernando; Monta?o,José;
Bioagro , 2011,
Abstract: with the purpose of assessing the growth and macronutrient accumulation patterns of the sugar cane plant and promote a rational fertilization management of the crop, an evaluation was carried out in a plot cropped with the rb 85-5035 variety, in chivacoa, yaracuy state, venezuela. the trial consisted on taking ten monthly samplings of the aerial portion of the plant, along the whole crop cycle. each sample consisted of three stumps, taken at random in a surface of 0.6 m2 per stump, and dry biomass content and macronutrient concentrations were determined on both leaves and stalks. in the months 11 and 12, additional samples were taken to determine the final dry biomass. at the end of cycle the crop accumulated 43.7 t·ha-1 dry biomass, with 75.1 % corresponding to the stalks and the remaining to the leaves. the accumulation of n, p, k, ca, mg, and s at 300 days after cutting (dac) was 201,4; 43,2; 149,0; 112,7; 71,1 y 71,6 kg·ha-1, respectively. nitrogen accumulated mainly in leaves during a good part of the cycle but at the end the nutrient was mainly translocated to the stems; it were found two critical periods of absorption, the first of which covered the stages of tillering and vegetative growth phase, and the second one was located at the stage of maturation of the reproductive phase. the nutrients p, k, mg and s were proportionally distributed in leaves and stems for most of the crop cycle, but differed dramatically from 251 dac, when the accumulation was directed mainly towards the stem. calcium was stored mainly in the leaves but at the end of the cycle the trend was reversed and the nutrient in the stems moderately exceeded that in the leaves. it was found that for the first four months of the plant growth the crop had produced just 16,5 % of its total biomass, but it had accumulated between 20 and 40 % of the macronutrients, which suggests the needs of their supply since the initial steps of the crop cycle.
Crecimiento y dinámica de acumulación de nutrientes en ca a de azúcar: II. micronutrientes Growth and dynamics of nutrient accumulation in sugarcane: I. Micronutrients
Marcos Rengel,Fernando Gil,José Monta?o
Bioagro , 2011,
Abstract: Con la finalidad de determinar la dinámica de acumulación y distribución de micronutrientes en el cultivo de ca a de azúcar variedad RB 85-5035, se condujo un estudio en Fundaca a, ubicada en la localidad de Chivacoa, estado Yaracuy, Venezuela. Se realizaron 10 muestreos de la parte aérea de la planta a través del ciclo de crecimiento. Cada muestra constó de tres cepas, tomadas al azar con una frecuencia mensual, en una superficie de 0,6 m2/cepa, a las cuales se les determinó la concentración de Fe, Cu, Zn, Mn, B y Mo en tallos y hojas. Las muestras de tejido fueron analizadas por los laboratorios Land Crop en York, Inglaterra. Se determinó que los períodos críticos de absorción de micronutrientes se ubican en la fase vegetativa y en la etapa de maduración del cultivo. Los micronutrientes Fe, Mn, B y Mo se almacenaron en mayor cantidad en el tejido foliar de la planta, mientras que Cu y Zn se acumularon de forma más pronunciada en los tallos a lo largo del ciclo. Los patrones de acumulación mostraron que los requerimientos de micronutrientes fueron: Fe=5241,5 g·ha-1, Cu=121,1 g·ha-1, Zn=875,6 g·ha-1, Mn=1142,4 g·ha-1, B=116,4 g·ha-1 y Mo=33,4 g·ha-1. With the purpose of determining the dynamics of micronutrient accumulation and partitioning of sugarcane var. RB 85-5035, a trial was conducted in Fundaca a, located in Chivacoa, Yaracuy State, Venezuela. Ten samples of the aerial part of the plant were taken through the growing season, and each sample consisted of three stumps, taken at random on a monthly basis in an area of 0.6 m2·cepa-1. Concentrations of Fe, Cu, Zn, Mn, B and Mo on stems and leaves were analyzed by Land Crop Laboratories in York, England. It was determined that the critical periods for micronutrient absorption are found in the vegetative phase and crop ripening. The micronutrients Fe, Mn, B and Mo were stored in greater amounts in the leaf tissue of the plant, while Cu and Zn accumulated more pronounced in the stems during the cycle. The accumulation patterns showed that the crop micronutrient requirements were: Fe=5241.5 g·ha-1, Cu=121.1 g·ha-1, Zn=875.6 g·ha-1, Mn=1142.4 g·ha-1, B=116.4 g·ha-1 and Mo=33.4 g·ha-1.
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