143 research outputs found
Satisfaction with Life Scale among adolescents and young adults in Portugal: extending evidence of construct validity
The paper presents three empirical studies designed to extend the test of the
construct validity of the Satisfaction With Life Scale (SWLS) among Portuguese students.
In the first study, the responses of 461 elementary and secondary education students were
submitted to a principal component analysis. A solution of one single factor was chosen, accounting for 55.7 % of the total variance, with Cronbach alpha coefficient and inter-item correlation above .70 and .20, respectively. The second study used a sample of 317
undergraduate students and registered a similar factor solution for SWLS (/pq = 0.99), which accounted for 65.6 % of the total variance (Cronbach alpha .89 and inter-item correlation above .20). A test–retest analysis registered coefficients of .70 (T2) and .77 (T3) and no significant statistically differences between T2, T3 and T1. The third study used a sample of 107 foster care youths from elementary and secondary education. Confirmatory factor analysis results indicate adequate fit indexes for the one-factor solution (v2/df = 2.70, GFI = .96, CFI = .96), which showed convergent validity, reliability and homogeneity. In conclusion, there is psychometric evidence for the one-factor structure of the SWLS in Portugal.FCTCOMPET
Platinum–rhodium–tin/carbon electrocatalysts for ethanol oxidation in acid media: effect of the precursor addition order and the amount of tin
Carbon-supported Pt x –Rh y –Sn z catalysts (x:y:z = 3:1:4, 6:2:4, 9:3:4) are prepared by Pt, Rh, and Sn precursors reduction in different addition order. The materials are characterized by X-ray diffraction, transmission electron microscopy, and X-ray photoelectron spectroscopy techniques and are evaluated for the electrooxidation of ethanol in acidic media by cyclic voltammetry, chronoamperometry, and anode potentiostatic polarization. The influence of both the order in which the precursors are added and the composition of metals in the catalysts on the electrocatalytic activity and physico-chemical characteristics of Pt x –Rh y –Sn z /C catalysts is evaluated. Oxidized Rh species prevail on the surface of catalysts synthesized by simultaneous co-precipitation, thus demonstrating the influence of synthesis method on the oxidation state of catalysts. Furthermore, high amounts of Sn in composites synthesized by co-precipitation result in very active catalysts at low potentials (bifunctional effect), while medium Sn load is needed for sequentially deposited catalysts when the electronic effect is most important (high potentials), since more exposed Pt and Rh sites are needed on the catalyst surface to alcohol oxidation. The Pt3–Rh1–Sn4/C catalyst prepared by co-precipitation is the most active at potentials lower than 0.55 V (related to bifunctional effect), while the Pt6–Rh2–Sn4/C catalyst, prepared by sequential precipitation (first Rh and, after drying, Pt + Sn), is the most active above 0.55 V.The authors thank the Brazilian National Council of Technological and Scientific Development-CNPq (Grants: 402243/2012-9, 303630/2012-4, 474261/2013-1, 407274/2013-8, and 310282/2013-6) for the scholarships and financial support for this work
Terra preta de indio "Dark Earth Soils": chemical and spectroscopic characterization of humic acids.
The HA of Amazonian dark earth soils (Terra Preta de Índio) from Brazilian territory were characterized using ultraviolet-visible, Fourier transform diffuse reflectance infrared, fluorescence excitation and emission, electron paramagnetic resonance, and nuclear magnetic resonance spectroscopy, thermogravimetric analysis, elemental composition, and measurement of acidity (total, carboxylic, phenolic)
Yield and nutritive value of Stylosanthes spp. genotypes subjected to different harvest frequencies and seasons of the year.
Productive and nutritional traits of forage species in various regions worldwide depend on different management strategies. This study aimed to evaluate the effects of harvest frequency (56, 77 and 98 days) and season of the year (rainy and dry) on the nutritional value and fractionation of carbohydrates and proteins of Stylosanthes genotypes (S. seabrana, S. scabra, S. mucronata and Stylosanthes spp. cv. Campo Grande). The experiment was conducted using a randomized complete block design with a split-plot arrangement and four repetitions. Contents of neutral detergent fibre (NDF), acid detergent fibre (ADF), in vitro digestible dry matter (IVDDM), condensed tannins and total phenolic compounds were influenced by the interaction of harvest frequency and season of the year. The 98-day harvest frequency resulted in lower IVDDM (579 g/kg) due to the high NDF and ADF concentrations during the rainy season. S. seabrana and S. scabra showed a higher proportion of A + B1 and B2 carbo- hydrate fractions, while the C fraction in the rainy season was greater in the Campo Grande, resembling S. seabrana. S. scabra displayed 15% of the crude protein in fraction A. The bromatological traits of Stylosanthes spp. did not decline sharply owing to plant age advancement, indicating these genotypes are suitable for forage production systems in tropical or semiarid regions
Substrates and controlled-release fertilizations on the quality of eucalyptus cuttings
To produce cuttings with quality, the most appropriate nutritional management strategies should be sought to reduce wastage of fertilizer, while accounting for the characteristics of each substrate. This study evaluated the effect of substrates and doses of controlled-release fertilizer on the quality of Eucalyptus grandis Hill ex Maiden x Eucalyptus urophylla S. T. Blake cuttings. The substrates consisted of several mixtures: vermiculite+carbonized rice chaff+coconut fibre (1:1:1); vermiculite+coconut fibre (1:1); and vermiculite+carbonized rice chaff (1:1). These mixtures were added to 2, 4, 6 and 8 kg of controlled-release fertilizer per cubic meter of substrate. The substrates that do not support root development and have lower water retention, independently of the dose of controlled-release fertilizer, reduce the quality of the root system. For substrates with proper values of water retention, such as vermiculite+coconut fibre (1:1) and vermiculite+carbonised rice chaff+coconut fibre (1:1:1), the utilization of dose 2 kg of controlled-release fertilizer to each cubic meter is enough to promote cuttings with greater quality of the root systems and proper heights and stem diameters.Deve-se buscar, para produzir mudas de qualidade, manejos nutricionais mais adequados que reduzam o desperdício de fertilizantes considerando as características de cada substrato. Este estudo avaliou o efeito de substratos e doses de fertilizante de liberação controlada na qualidade de mudas clonais de Eucalyptus grandis Hill ex Maiden x Eucalyptus urophylla S. T. Blake. Os substratos se constituíram das seguintes misturas: vermiculita+casca de arroz carbonizada+fibra de coco (1:1:1); vermiculita+fibra de coco (1:1) e vermiculita+casca de arroz carbonizada (1:1). A essas misturas foram adicionados 2, 4, 6 e 8 kg de fertilizante de liberação controlada por metro cúbico do substrato. Os substratos que não dão suporte ao crescimento das raízes e possuem baixa retenção de água, independente da dose de fertilizante de liberação controlada, reduzem a qualidade do sistema radicular. Para substratos com capacidade adequada de retenção de água, como os constituídos por vermiculita+fibra de coco (1:1) e vermiculita+casca de arroz carbonizada+fibra de coco (1:1:1) a dose 2 kg de fertilizante de liberação controlada por metro cúbico é suficiente para formar mudas com alturas da parte aérea e diâmetros do colo adequados e sistema radicular de qualidade.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)UNESPCEETPSUNES
Mast cell concentration and skin wound contraction in rats treated with Brazilian pepper essential oil (Schinus terebinthifolius Raddi)
PURPOSE: To evaluate wound contraction and the concentration of mast cells in skin wounds treated with 5% BPT essential oil-based ointment in rats. METHODS: Twenty rats, male, of adult age, were submitted to skin surgery on the right (RA) and left antimeres (LA) of the thoracic region. They were divided into two groups: control (RA - wounds receiving daily topical application of vaseline and lanolin) and treated (LA - wounds treated daily with the topical ointment). The skin region with wounds were collected at days 4, 7, 14 and 21 after surgery. Those were fixed in 10% formaldehyde and later processed for paraffin embedding. Sections were obtained and stained by H.E for histopathology analysis. The degree of epithelial contraction was measured and mast cell concentration were also evaluated. RESULTS: The treated group showed higher mast cell concentrations (p<0.05) associated with increased contraction at day 7 and 14 respectively. CONCLUSION: Ointment containing 5% Brazilian pepper tree oil increases mast cell concentration and promotes skin wound contraction in rats.UFRPEUNIFESPUFMGUNESPUNES
Growth and yield of sugarcane as a function of phosphorus doses and forms of application
ABSTRACT This study aimed to evaluate sugarcane growth and its agricultural and industrial yield influenced by phosphorus (P) sources and forms of application. The experiment was carried out at the Paisa Sugar Mill, in Penedo-AL, Brazil, from February 2012 to February 2013. The adopted experimental design was a randomized block in a factorial arrangement, with four replicates. The treatments consisted of five doses of triple superphosphate applied in the planting furrow (0, 50, 100, 150 and 200 kg ha-1 of P2O5), and three doses of Bayóvar reactive phosphate rock (0, 100 and 200 kg ha-1 of P2O5) applied in the total area. Phosphorus applied in the planting furrow improved sugarcane quality through the reduction of fiber and increases in purity, corrected pol, total recoverable sugar, ton of pol per hectare (TPH) and ton of sugarcane per hectare (TSH). The Bayóvar reactive phosphate rock promoted increases in stem diameter at 120 days after planting (DAP), TPH and TSH. For the interaction triple superphosphate applied in the planting furrow x Bayóvar reactive phosphate rock applied in the total area, there were significant differences in the number of tillers at 30 DAP, stem diameter at 120 DAP and TSH
Bronquiolite viral: aspectos epidemiológicos, fisiopatológicos e manejo terapêutico
A Bronquiolite Viral (BV) é uma condição aguda que afeta o trato respiratório inferior. Especialmente comum durante os meses mais frios do outono e inverno, a BV é uma das principais causas de hospitalização em crianças. O Vírus Sincicial Respiratório (VSR) é frequentemente associado à BV e pode levar a complicações graves em bebês, incluindo letargia, febre, inapetência, otite média, entre outras. Na maioria dos casos, em lactentes, a doença se apresenta de forma leve e pode ser resolvida em algumas semanas. O diagnóstico da BV pode ser realizado clinicamente, com exames adicionais usados para avaliar possíveis complicações. Os critérios de internação incluem baixos níveis de saturação de oxigênio, sinais de desconforto respiratório moderado a grave, apneia e desidratação. O tratamento geralmente envolve medidas de suporte, garantindo uma oxigenação adequada, uma melhora da respiração e também atendendo as necessidades de fluidos e nutrição das crianças. Todavia, ainda existe uma grande necessidade de novos estudos a respeito da BV, objetivando-se sanar as lacunas do conhecimento evidenciadas no presente artigo
Performance of a reciprocal shaker in mechanical dispersion of soil samples for particle-size analysis
The dispersion of the samples in soil particle-size analysis is a fundamental step, which is commonly achieved with a combination of chemical agents and mechanical agitation. The purpose of this study was to evaluate the efficiency of a low-speed reciprocal shaker for the mechanical dispersion of soil samples of different textural classes. The particle size of 61 soil samples was analyzed in four replications, using the pipette method to determine the clay fraction and sieving to determine coarse, fine and total sand fractions. The silt content was obtained by difference. To evaluate the performance, the results of the reciprocal shaker (RSh) were compared with data of the same soil samples available in reports of the Proficiency testing for Soil Analysis Laboratories of the Agronomic Institute of Campinas (Prolab/IAC). The accuracy was analyzed based on the maximum and minimum values defining the confidence intervals for the particle-size fractions of each soil sample. Graphical indicators were also used for data comparison, based on dispersion and linear adjustment. The descriptive statistics indicated predominantly low variability in more than 90 % of the results for sand, medium-textured and clay samples, and for 68 % of the results for heavy clay samples, indicating satisfactory repeatability of measurements with the RSh. Medium variability was frequently associated with silt, followed by the fine sand fraction. The sensitivity analyses indicated an accuracy of 100 % for the three main separates (total sand, silt and clay), in all 52 samples of the textural classes heavy clay, clay and medium. For the nine sand soil samples, the average accuracy was 85.2 %; highest deviations were observed for the silt fraction. In relation to the linear adjustments, the correlation coefficients of 0.93 (silt) or > 0.93 (total sand and clay), as well as the differences between the angular coefficients and the unit < 0.16, indicated a high correlation between the reference data (Prolab/IAC) and results obtained with the RSh. In conclusion, the mechanical dispersion by the reciprocal shaker of soil samples of different textural classes was satisfactory. The results allowed recommending the use of the equipment at low agitation for particle size- analysis. The advantages of this Brazilian apparatus are its low cost, the possibility to simultaneously analyze a great number of samples using ordinary, easily replaceable glass or plastic bottles
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