59 resultados para Sagittal abdominal diameter


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The waistline of America has been expanding now for decades,1 largely as a consequence of an obesogenic environment, with a car-worshipping culture and take-away lifestyle par excellence.2 No upper limit to the prevalence or extent of obesity is yet apparent, and many countries and communities worldwide are busily following the American lead. Accumulating research evidence suggests that the personal and economic costs of the obesity epidemic are immense,3 driven by the obesity-related increases in risk for conditions such as type 2 diabetes mellitus, the metabolic syndrome, cardiovascular disease (CVD), kidney disease, arthritis, cancer, asthma, and sleep-disordered breathing. In addition, decreases are apparent in self-esteem and quality of life.

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Sources of variation in fibre diameter attributes of Australian alpacas and implications for fleece evaluation and animal selection were investigated using data collected in the years 1994–97, from 6 properties in southern Australia. Data were analysed using REML (multiple regression analysis) to determine the effect on mean fibre diameter (MFD) and coefficient of variation of MFD (CV(FD)) of age, origin (property), sex (entire male, female), breed (Huacaya, Suri), liveweight, fibre colour, individual, and interactions of these effects. The mean (n = 100) age (range) was 4.2 years (0.1–11.9), liveweight 72.0 kg (12.0–134 kg), MFD 29.1 μm (17.7–46.6 μm), CV(FD) 24.33% (15.0–36.7%).

A number of variables affected MFD and CV(FD). MFD increased to 7.5 years of age, and correlations between MFD at 1.5 and 2 years of age with the MFD at older ages were much higher than correlations at younger ages. Fibre diameter 'blowout' (increase with age) was positively correlated with the actual MFD at ages 2 years and older. There were important effects of farm, and these effects differed with year and shearing age. Suris were coarser than Huacayas with the effect reducing with increased liveweight; there was no effect of sex. Fleeces of light shade were 1 μm finer than dark fleeces. CV(FD) declined rapidly between birth and 2 years of age, reaching a minimum at about 4 years of age and then increasing; however, CV(FD) measurements on young animals were very poor predictors of CV(FD) at older ages, and the response of CV(FD) to age differed with farm and year. Suris had a higher CV(FD) than Huacayas on most properties, and MFD, liveweight, and sex did not affect CV(FD). Fleeces of dark shade had higher CV(FD) than fleeces of light shade in 2 of the years. It is concluded that there are large opportunities to improve the MFD and CV(FD) of alpaca fibre through selection and breeding. The potential benefit is greatest from reducing the MFD and CV(FD) of fibre from older alpacas, through reducing the between-animal variation in MFD and CV(FD). Sampling alpacas at ages <2 years is likely to substantially decrease selection efficiency for lifetime fibre diameter attributes.

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Wool fabrics are often treated under conditions of varying pH in dyeing and finishing processes. It is known that in air the dimensions of wool fabrics change with the amount of fiber swelling at different regain. In this work, it has been shown that a similar relationship between fiber swelling and fabric dimensions existed in water at different pH values. The diameters of Merino and Corriedale wool fibers in water at different pH values were measured with an OFDA 2000 fiber diameter analyzer, fitted with a specially constructed accessory liquid cell. The results showed that the mean diameters of swollen wool fibers in water varied with pH. Minimum swelling was obtained in the range pH 5-7. It was found that the dimensions of wool fabric in water were dependent on the pH. The changes in fiber diameter in water could be attributed to changes in ionic interactions between charged acid and basic groups in wool protein with variations in pH.

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This work established and experimentally validated several models for accurately predicting wool fibre and yarn properties. The results will be useful in fibre selection, and will help predict fibre processing performance and end-product quality.

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The presentwork aimed to determine howthe average fibre diameter coefficient of variation (CVD) and fibre curvature (FC) differences between nine sampling sites vary between sex and flock, to identify differences in variability between sampling sites as a result of between animal and between sire variability and to determine correlations between sampling sites in between animal and between sire variability. Australian Angoras (n = 313) from two farms in southern Australia were sampled at 12 and 18 months of age at nine sites (mid side, belly, brisket, hind flank, hip, hock, mid back, neck, shoulder). Staples were taken prior to shearing at skin level and CVD and FC determined. For each shearing, differences in CVD and FC between sampling sites, how these differences were affected by farm, sex, and sire, and the covariance between sites for sire and individual animal effects were investigated by restricted maximum likelihood (REML) analyses. The median mid side CVD at 12 and 18 months of age ranged from 23.6 to 25.1% but the actual range was 16.8–34.2%. The median mid side FC at 12 and 18 months of age ranged from 14.4 to 18.6◦/mm but the actual range was 10.5–26.3◦/mm. The general pattern for CVDwas for the mid back, hip and neck sites to have similar CVD, the brisket, hind flank and hock sites to have larger CVD and the belly to have smaller CVD than the mid side site. The between animal variation for CVD was lowest at the mid back site. This implies that the mid back would be the most effective site for between animal selection for CVD. Heritabilities for CVD (range at 18 months 0.18–0.30) were only about half the heritabilities for mean fibre diameter in the same study. There was a marked anterior–posterior increase in FC at both farms and with both ages. The results give no clear indication of the best site for between animal selection for FC, other than that the hock should be avoided. Heritabilities for FC are moderate to high (range at 18 months 0.44–0.77) and the genetic correlations are high except for the hock. Thus genetic selection for FC at any site, other than the hock, should be effective for changing FC over the entire fleece. There was more variability between animals than between sites and sires. These results are put into context with associated research on variation in mean fibre diameter and staple length.

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Yarn diameter and packing density are difficult to measure directly. Existing models on fibre packing density in a yarn assume that all fibres are uniform and have an identical diameter. Yet real staple yarns, such as wool yarns, consist of fibres of varying diameters. This paper proposes an effective and simple yarn model for calculating the average diameter of yarns, in which fibres have circular cross-section and the close packing in the yarn cross-section. The concept of “area equivalent diameter” is introduced to transform fibres of varying diameters to identical fibres with one equivalent diameter to simplify the calculations of the average yarn diameter for a range of yarns.

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An abdominal profile index (API) was developed for pink-footed geese Anser brachyrhynchus as a measure of body condition. On basis of carcass analysis of 56 adult geese with known API prior to collection, we found significant linear relationships between API against body mass, abdominal fat and total energy content. Hence, changes in API reflect net energy intake rates. As an example of the applicability of the calibration, we compared APIs of individually marked geese before and after long migration episodes and estimated the cost of flight at 8.9 kJ/km. In addition we estimated gain rates at three major staging sites along the spring flyway indicating an increase in fueling rates with latitude. Calibration of APIs and energy contents offers new opportunities for field studies of waterfowl energetics.

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In this paper, a new technique has been developed to enable fibre diameters to be measured in an aqueous environment using the OFDA 2000 instrument. The existing OFDA instrument has only been used to measure diameters of animal fibres under dry conditions. This new technique was utilised to assess the effects of pH and temperature on the diameters of merino wool fibres in aqueous environments. Significant changes in fibre diameter under aqueous conditions were found as a function of pH and temperature. Wool fibre diameters were at a minimum close to the wool isoelectric point (pH 4.8) and increased at both lower and higher pHs. Swelling of merino wool fibres was observed to increase linearly by around 15% as the temperature rose from ambient to 70°C.