Precisão da técnica de absorciometria de raios-x de dupla energia na determinação da composição corporal em gatos Precision of dual energy x-ray absorptiometry for body composition measurements in cats

<abstract language="eng">A short-term precision error of the individual subject and the DEXA technique, such as the effect of the repositioning of the cat on the examination table, were established. Four neutered adult cats (BW=4342g) and three females (BW=3459g) were submitted to five repeated scans with and without repositioning between them. Precision was estimated from the mean of the five measurements and expressed by the individual coefficient of variation (CV). The precision error of the technique was estimated by the variance of scan pool (n=35) and expressed in CV for the technique (CVt). The degrees of freedom and confidence intervals were determined to avoid underestimation of precision errors. Bone mineral content (BMC), lean mass (LM), and fat mass (FM) averages were higher (P<0.05) when animals were repositioned. The CVt was significantly higher (P<0.05) for bone mineral density (BMD), LM, and FM when the animals were repositioned. For short-term precision measurements, the repositioning of the animal was important to establish the precision of the technique. The dual energy x-ray absorptiometry method provided precision for body composition measurements in adult cats

Investigating the Effect of Ageing on the Behaviour of Chalk Putty

Substantial recent investment in offshore wind energy developments and other foundation projects in chalk dominated locations has created an urgent need for a better understanding of how driven piles behave in this variable and unpredictable material. Pile driving in chalk is known to create a remoulded zone of chalk ‘putty’ around the pile which mobilises low shaft resistance on installation; however, shaft capacity has been reported to increase over time through a process referred to as pile ‘set-up’ or ageing. Although field evidence of ageing has been reported, the potential role of the chalk putty’s behaviour in the ageing process is not well understood. This is partly due to a lack of published laboratory testing on chalk samples which have been conditioned to represent the conditions adjacent to a pile after driving. This paper presents selected results from a suite of laboratory tests undertaken at Imperial College London. Specimens from intact Maastrichtian Chalk were reduced to putty by Proctor compaction applied at natural water content and subjected to either drained or undrained ageing for periods of between 0 and 28 days. Consolidated undrained triaxial tests, with pore water pressure measurement and local strain measurements, were undertaken on the aged specimens, along with thixotropy testing on unconsolidated samples employing a fall cone. An interpretation of the test results within a critical state framework combined with a conceptual small strain stiffness model is presented. The ageing of chalk putty is shown to encompass a combination of consolidation, thixotropic hardening and re-cementation, with small increases in undrained shear strength seen due to thixotropic hardening, and larger increases in strength evident following consolidation

Alelopatia em extratos de frutos de juazeiro (Ziziphus joazeiro Mart. - Rhamnaceae)

O objetivo deste trabalho foi avaliar o potencial alelopático do extrato de frutos de juazeiro (Ziziphus joazeiro Mart.) sobre as sementes de alface (Lactuca sativa). O experimento foi conduzido em delineamento inteiramente casualizado com 4 repetições e cinco tratamentos (0%, 25%, 50%, 75% e 100% de concentração do extrato bruto). O extrato bruto foi obtido após a extração manual da polpa do fruto e agitação com água em liquidificador utilizando-se 50g de polpa para 500ml de água, e o mesmo foi feito com a casca do fruto. Os resultados mostraram efeito do extrato dependendo da concentração. As maiores concentrações do extrato (100%, 75% e 50%) da polpa dos frutos Z. joazeiro apresentaram efeito alelopático desfavorável sobre a germinação de alface, reduzindo-a em 100%, 98,75% e 82,5% respectivamente. O extrato das cascas dos frutos nas concentrações de 75% e 100% reduziu a germinação da alface em 28,75% e 78,75%

Rendimento e composição químico-bromatológica de fenos triturados de gramíneas tropicais Yield and chemical composition of chopped tropical grass hays

A pesquisa foi conduzida objetivando avaliar o rendimento, a composição químico-bromatológica e as perdas de fenos triturados de milheto, sorgo sudanense, capim-elefante e sorgos forrageiros (SF-25 e IPA-467-4-2). Os materiais foram colhidos quando atingiram 30% de inflorescências, com exceção do capim-elefante, colhido aos 60 dias. Utilizou-se delineamento de blocos completos casualizados, com cinco tratamentos e quatro repetições. Houve diferenças significativas, com maiores produções de feno para os sorgos IPA-467-4-2 (10,85 t/ha/corte) e SF-25 (10,65 t/ha/corte), que foram superiores ao capim-elefante, sorgo sudanense e milheto, com, respectivamente, 6,94; 6,69 e 4,93 t/ha/corte. Os percentuais de perdas na fenação não diferiram entre os tratamentos, com níveis variando de 17,33 a 20,17%. Os fenos de milheto e sorgo sudanense tiveram as maiores concentrações de PB (10,56 e 8,80%), superiores às do capim-elefante (6,76%) e dos sorgos SF-25 (5,62%) e IPA-467-4-2 (5,50%). Os valores de FDN foram, na maioria, superiores a 70,0%. As menores concentrações de NIDN foram observadas nos cultivares de sorgo (0,42 e 0,40% da MS). As concentrações de NIDA variaram de 0,06 a 0,30% na MS. As maiores concentrações de lignina (%MS) dos fenos foram obtidas no milheto (6,52%) e no sorgo IPA-467-4-2 (6,17%). As concentrações de nutrientes digestíveis totais estimadas (NDTe) dos fenos diferiram significativamente, com o maior valor para o sorgo sudanense (53,35%). Os fenos triturados das gramíneas tropicais avaliadas apresentaram rendimentos elevados e composição químico-bromatológica dentro dos padrões mínimos recomendáveis para nutrição de ruminantes.<br>The research was carried out to evaluate yield, chemical composition and losses of chopped tropical grass hays with the following forages: pearl millet (Pennisetum americanum), sudangrass (Sorghum sudanense), elephantgrass (Pennisetum purpureum) and two cultivars of forage sorghum (SF-25 and IPA-467-4-2) (Sorghum bicolor). The materials were harvested at 30% flowering, except for elephantgrass (60 days). The experiment was conducted according to a complete randomized block design, with five treatments and four replications. There were significant differences among hay productions with sorghum cultivars IPA-467-4-2 and SF-25 reaching the highest yields (10.85 and 10.65 t/ha/cut). Production of elephantgrass, sudangrass and pearl millet hays were respectively of 6.94, 6.69, and 4.93 t/ha/cut. Percentage of hay losses were not different among all treatments and varied from 17.33 to 20.17%. Pearl millet and sudangrass hays had the highest CP concentrations (10.56 and 8.80%), which were superior to elephantgrass (6.76%) and sorghum cultivars (5.62 and 5.50%). Most of the NDF values were superior to 70.0%. Sorghum cultivars exhibited the lowest NDIN concentration (0.42 and 0.40% of DM). The ADIN concentration ranged from 0.06 to 0.30% of DM. The highest lignin (%DM) concentration was observed for pearl millet (6.52%) and sorghum IPA-467-4-2 (6.17%) hays. Estimated TDN of the hays showed significant differences and sudangrass reached the highest value (53.35%). Production of chopped tropical grass hays showed high yields and chemical composition according to the minimum standards for ruminant nutrition