1,847 research outputs found
Avaliação do desempenho de um modelo de estimativa de saldo de radiação em algumas culturas.
Avaliou-se o desempenho do método de estimativa do saldo de radiação proposto por ALLEN, 1998, em experimentos de culturas de girassol, amendoim, café, limão e grama, através de regressões lineares com base nos indicadores estatísticos coeficiente de correlação r?, índice de Willmott ?d? e índice de desempenho ?c?. Segundo os critérios de avaliação do índice ?c?, o método proposto por ALLEN, 1998 representa de forma satisfatória os dados de saldo de radiação, sendo obtidos os desempenhos equivalentes a 0,79 (muito bom) para as culturas de girassol e grama e de 0,96; 0,86 e 0,88 (ótimo) para as culturas de amendoim, café e limão, respectivamente.CBA 2009
Focal adhesion kinase and its role in skeletal muscle
Skeletal muscle has a remarkable ability to respond to different physical stresses. Loading muscle through exercise, either anaerobic or aerobic, can lead to increases in muscle size and function while, conversely, the absence of muscle loading stimulates rapid decreases in size and function. A principal mediator of this load-induced change is focal adhesion kinase (FAK), a downstream non-receptor tyrosine kinase that translates the cytoskeletal stress and strain signals transmitted across the cytoplasmic membrane by integrins to activate multiple anti-apoptotic and cell growth pathways. Changes in FAK expression and phosphorylation have been found to correlate to specific developmental states in myoblast differentiation, muscle fiber formation and muscle size in response to loading and unloading. With the capability to regulate costamere formation, hypertrophy and glucose metabolism, FAK is a molecule with diverse functions that are important in regulating muscle cell health
Differential alterations in gene expression profiles contribute to time-dependent effects of nandrolone to prevent denervation atrophy
<p>Abstract</p> <p>Background</p> <p>Anabolic steroids, such as nandrolone, slow muscle atrophy, but the mechanisms responsible for this effect are largely unknown. Their effects on muscle size and gene expression depend upon time, and the cause of muscle atrophy. Administration of nandrolone for 7 days beginning either concomitantly with sciatic nerve transection (7 days) or 29 days later (35 days) attenuated denervation atrophy at 35 but not 7 days. We reasoned that this model could be used to identify genes that are regulated by nandrolone and slow denervation atrophy, as well as genes that might explain the time-dependence of nandrolone effects on such atrophy. Affymetrix microarrays were used to profile gene expression changes due to nandrolone at 7 and 35 days and to identify major gene expression changes in denervated muscle between 7 and 35 days.</p> <p>Results</p> <p>Nandrolone selectively altered expression of 124 genes at 7 days and 122 genes at 35 days, with only 20 genes being regulated at both time points. Marked differences in biological function of genes regulated by nandrolone at 7 and 35 days were observed. At 35, but not 7 days, nandrolone reduced mRNA and protein levels for FOXO1, the mTOR inhibitor REDD2, and the calcineurin inhibitor RCAN2 and increased those for ApoD. At 35 days, correlations between mRNA levels and the size of denervated muscle were negative for RCAN2, and positive for ApoD. Nandrolone also regulated genes for Wnt signaling molecules. Comparison of gene expression at 7 and 35 days after denervation revealed marked alterations in the expression of 9 transcriptional coregulators, including Ankrd1 and 2, and many transcription factors and kinases.</p> <p>Conclusions</p> <p>Genes regulated in denervated muscle after 7 days administration of nandrolone are almost entirely different at 7 versus 35 days. Alterations in levels of FOXO1, and of genes involved in signaling through calcineurin, mTOR and Wnt may be linked to the favorable action of nandrolone on denervated muscle. Marked changes in the expression of genes regulating transcription and intracellular signaling may contribute to the time-dependent effects of nandrolone on gene expression.</p
Endovascular treatment of superior vena cava syndrome: case report and review of the literature
We report a case of a patient with symptomatic benign superior vena cava syndrome treated by the endovascular technique. The angiographic resonance before angioplasty showed extensive thrombosis of the left brachiocephalic trunk, left subclavian vein and superior vena cava obstruction close to the right brachiocephalic trunk. The patient underwent radical mastectomy 2 years ago with adjuvant chemotherapy and chest radiotherapy. Venous angioplasty and balloon-expandable stenting were performed. Satisfactory result was obtained with immediate relief of symptoms due to recanalization of the right brachiocephalic trunk and superior vena cava. Oral anticoagulation was initiated. The patient is still asymptomatic after 8 months of follow-up. The endovascular treatment is a therapeutic alternative with low morbidity and satisfactory mid-term results that can be offered to patients with superior vena cava syndrome.Relatamos o caso de uma paciente portadora de síndrome da veia cava superior sintomática de origem benigna tratada pela técnica endovascular. A angiorressonância magnética pré-angioplastia evidenciou extensa trombose do tronco braquiocefálico esquerdo, da veia subclávia esquerda e obstrução da veia cava superior junto ao tronco braquiocefálico direito. A paciente realizou mastectomia radical 2 anos antes, associada à quimioterapia e radioterapia do tórax. Foram realizados angioplastia venosa e implante de stent expansível por balão. O resultado foi satisfatório, com alívio imediato dos sintomas devido à recanalização da veia cava superior e do tronco braquiocefálico direito. Foi instituída anticoagulação oral. A paciente permanece sem recidiva dos sintomas após 8 meses de acompanhamento. O tratamento endovascular é uma alternativa terapêutica com baixa morbidade e resultado satisfatório a médio prazo que pode ser oferecida aos pacientes portadores de síndrome da veia cava superior.Fundação Faculdade Federal de Ciências Médicas de Porto AlegreSanta Casa de Porto AlegreUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de MedicinaUNIFESP, EPMSciEL
Diet, microhabitat use, and thermal preferences of Ptychoglossus bicolor (Squamata: Gymnophthalmidae) in an organic coffee shade plantation in Colombia
Ptychoglossus bicolor is a small gymnophthalmid lizard distributed in the Magdalena Valley of Colombia. We studied ecological features of diet, microhabitat use, and thermal preferences of a population found in an organic coffee shade plantation at the Cordillera Oriental of the Colombian Andes. The studied population had a diet composed predominantly of isopods. The Relative Importance Index of isopods was 98.8%; there were no significant monthly differences in the full stomach content and volume of isopods eaten during the sampling year, neither between rainy and dry seasons. A large number of lizards were found active in the leaf-litter, buried around coffee tree roots, and under or in rotting logs. Lizard body temperature was positively correlated with substrate temperature and air temperature; sex differences in body temperature were not significant. At the studied locality we did not find lizards out of the coffee fields. Our results suggested that these lizards successfully cope with the conditions offered by the organic coffee areas as a result of the cultivation system. Thus, this population might be vulnerable to any modification of the habitat that changes microhabitat availability and abundance of isopods.Ptychoglossus bicolor es un pequeño lagarto de la familia Gymnophthalmidae, que habita el valle del Río Magdalena de Colombia. Se estudiaron las características ecológicas de la dieta, uso de microhábitat y preferencias termales de una población que habita una plantación de café orgánico bajo sombra en la Cordillera Oriental colombiana. La dieta en esta población está dominada por isópodos. El Índice Valor de Importancia Relativa fue del 98.8% y no hubo diferencias mensuales significativas en el contenido estomacal y el volumen de isópodos consumidos durante el año, ni tampoco entre las estaciones de lluvia y seca. Un gran número de lagartos fueron encontrados activos entre la hojarasca, enterrados junto a las raíces de los árboles y bajo o dentro de troncos en descomposición. La temperatura corporal estuvo positivamente correlacionada con las temperaturas del suelo y del aire y no hubo diferencias significativas en temperatura corporal entre los sexos. En esta localidad no encontramos lagartos fuera de los campos de cultivo de café. Nuestros resultados sugieren que estos lagartos sobrellevan exitosamente las condiciones ofrecidas por los cafetales orgánicos como resultado del sistema de cultivo. Así, esta población podría ser vulnerable a cualquier modificación del hábitat que cambie la disponibilidad de microhábitats y la abundancia de isópodos
Balanço de energia em amendoim irrigado.
O presente estudo utilizou o método do balanço de energia através da razão de Bowen para estimar os fluxos de calor latente (LE) e sensível (H) a partir de medidas do saldo de radiação (Rn), fluxo do calor do solo (G) e gradientes psicométricos (com termopares) em dois cultivares amendoim (Arachis hypogaea L.) irrigado. Os resultados indicam que a partição de Rn em fluxos de LE, H e G varia durante o ciclo, principalmente em função do desenvolvimento vegetativo da cultura. O método da razão de Bowen propiciou medidas de consumo hídrico coerentes com a cultura do amendoim (valores médios de 6 mm.dia-1 para ambos os cultivares).CBA 2009
The blackcap (Sylvia atricapilla) genome reveals a species-specific accumulation of LTR retrotransposons
Transposable elements are mobile genetic elements that have the ability to move around the genome, and as such can be a source of genome variability. Transposable elements (TEs) are ubiquitous and many are found within a wide variety of life. Based on their characteristics we can annotate TEs within the host genome and classify them into specific TE types and families. The increasing number of available high-quality genome references in recent years provides an excellent resource that will enhance the understanding of the role of recently active TEs on genetic variation and phenotypic evolution. Here we showcase this through a high-quality TE annotation of the Eurasian blackcap (Sylvia atricapilla), as our chromosome resolution reference genome allowed the reconstruction of difficult-to-assemble regions. We have the ability to distinguish species-specific and non-specific TEs. We investigate how these TE categories are distributed along the genome and evaluate their correlation with four genomic features: recombination rate, gene coverage, CpG island coverage and GC coverage. We found a marked difference between species-specific and non-specific TEs. While species-specific TEs were negatively correlated with both GC content and recombination rate, the correlation with recombination rate disappeared and turned positive for GC content when considering non-specific TEs
Growth, Nitrogen and Phosphorus Economy in Two \u3ci\u3eLotus Glaber\u3c/i\u3e Mill. Cytotypes Grown Under Contrasting P-Availability
Lotus glaber Mill. (lotus) is a forage legume with its origin in Europe which has shown an excellent adaptation to the Depressed Pampas of the Province of Buenos Aires, Argentina. The soils colonized by lotus usually have poor drainage, moderate sodium and low extractable P concentrations. An experiment was performed with the aim of comparing the early growth and economy of phosphorus (P) and nitrogen (N) within two L. glaber cytotypes differing in their ploidy level, a commercial diploid versus an induced autotetraploid population (Barufaldi et al., 2001)
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