Undernutrition in grazing sheep. III.* Body composition and its estimation in vivo

1972 ◽  
Vol 23 (3) ◽  
pp. 511 ◽  
Author(s):  
DJ Farrell ◽  
TF Reardon

Twenty-four sheep, 12 fitted with rumen cannulae, were divided into three similar groups and kept at pasture. The grazing intake of group A was not restricted, but groups B and C were undernourished for a period of about 4 months and were then maintained in thin condition for a further 9 months, when all sheep were killed. The mean fat content was then 27, 9, and 5% of mean body weight in groups A, B, and C respectively. Undernourished sheep had a significantly higher (P < 0.01) water content in the fat-free empty body than well-nourished sheep. Multiple regression equations relating the fat, protein, and estimated energy contents of the body to tritiated water space and body weight differed between well-nourished and undernourished sheep. This was due to the larger amount of water in the rumell-reticulum of thin sheep and to the high water content of their fat-free body. __________________ *Part II, Aust. J. Agric. Res., 23: 499 (1972)

1954 ◽  
Vol 31 (2) ◽  
pp. 165-187
Author(s):  
BARBARA H. DAINTON

1. The effect of moisture and temperature on the activity of slugs has been investigated in the laboratory and in the field. 2. Atmospheric moisture has no direct effect on activity, though it may limit the duration of activity by influencing the water content of the body. Animals of high water content are not inherently active but they respond more readily to other stimuli than animals of low water content. 3. Between 4 and 20° C. activity is induced by falling temperatures and suppressed by rising temperatures. Temperature changes as slight as 0.1° C. per hour are perceived. 4. The daily rhythm of activity and rest thus follows the normal diurnal rhythm of falling temperature by night and rising temperature by day, except when daytime mists and showers superimpose a minor fluctuation and result in daytime activity. No activity is observed on continuously wet days which are normally without such fluctuations. 5. Between 20 and 30° C. activity is induced by rising temperatures and suppressed by falling temperatures. The ecological significance of this is discussed. 6. When maintained at constant temperature slugs show a persistent but immediately and steadily deteriorating diurnal rhythm of activity and rest which could not of itself account for the regular appearance of nocturnal activity in the field. 7. In a temperature gradient slugs aggregate about a preferred temperature. The ecological significance of this is discussed. 8. The difficulty of describing these reactions in the terminology put forward by Fraenkel & Gunn (1940) is considered.


Sensors ◽  
2020 ◽  
Vol 20 (13) ◽  
pp. 3756
Author(s):  
Marta Cavagnaro ◽  
Giuseppe Ruvio

Dielectric characterization of biological tissues has become a fundamental aspect of the design of medical treatments based on electromagnetic energy delivery and their pre-treatment planning. Among several measuring techniques proposed in the literature, broadband and minimally-invasive open-ended probe measurements are best-suited for biological tissues. However, several challenges related to measurement accuracy arise when dealing with biological tissues in both ex vivo and in vivo scenarios such as very constrained set-ups in terms of limited sample size and probe positioning. By means of the Finite Integration Technique in the CST Studio Suite® software, the numerical accuracy of the reconstruction of the complex permittivity of a high water-content tissue such as liver and a low water-content tissue such as fat is evaluated for different sample dimensions, different location of the probe, and considering the influence of the background environment. It is found that for high water-content tissues, the insertion depth of the probe into the sample is the most critical parameter on the accuracy of the reconstruction. Whereas when low water-content tissues are measured, the probe could be simply placed in contact with the surface of the sample but a deeper and wider sample is required to mitigate biasing effects from the background environment. The numerical analysis proves to be a valid tool to assess the suitability of a measurement set-up for a target accuracy threshold.


1970 ◽  
Vol 75 (3) ◽  
pp. 497-500 ◽  
Author(s):  
T. W. Searle

SUMMARYThe body composition of parasite-infected sheep and of healthy sheep of various body weights and breeding was predicted from tritiated water (TOH) space and body weight using previously published regression equations. Results agreed well with body composition determined by analysis of the minced carcass though a small bias existed in some groups. It is concluded that the equations have a general application to the prediction of body composition in sheep.


2013 ◽  
Vol 33 (8) ◽  
pp. 757-765 ◽  
Author(s):  
Ahmed Awadallah-F ◽  
Tahia B. Mostafa

Abstract Graft copolymerization of acrylonitrile and acryloyl chloride on to chitosan was prepared by γ-rays. Optimization of the grafting (%) was studied. The grafting (%) was observed to increase with increase in the irradiation dose and monomer concentration. The grafting percentages were about 52% and 36% from polyacrylonitrile and poly(acryloyl chloride), respectively. Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) were used to characterize the specimens. The modified chitosan was loaded with vitamin B12, demonstrated nearly 5.0±2.3% and 50.1±4.5% release in the media of pH 1.2 and 6.8, respectively, for amidoximated chitosan-grafted polyacrylonitrile and 3.6±1.1% and 36±2.4% in pH 1.2 and 6.8, respectively, for chitosan-grafted poly(acryloyl chloride), as determined by a traditional dissolution model. The modified chitosan specimens that uploaded with vitamin B12 displayed a more decremental release in the acidic medium than the neutral one. However, in order to incorporate in vivo gastrointestinal conditions, such as acidic pH and high water content in the stomach, low water content, and the presence of semi-solid mass in the large intestine, a new model, called flow through diffusion cell, was also used to study the drug release. The results of the two approaches produced different release profiles at the same pH values.


1975 ◽  
Vol 26 (2) ◽  
pp. 355 ◽  
Author(s):  
TW Searle ◽  
NMcC Graham

Wether sheep (4 months old) were held at 20 kg liveweight by restricted feeding for either 4 or 6 months and then fed ad libitum. Body composition (total water, fat and protein) was estimated monthly from tritiated water (TOH) space measured in vivo, and on three occasions representative animals were slaughtered, minced and analysed. Composition at any given body weight was compared with that previously determined for animals grown without restriction (controls). Sheep slaughtered at the end of the period of weight stasis contained less protein and more water than the controls but contained a similar weight of fat. Previously derived prediction equations estimated water correctly from TOH space in these undernourished sheep, but protein was overestimated by 0.38 kg (17% of the mean) and fat was underestimated by 0.19 kg (10% of the mean). The body composition of animals slaughtered after partial or complete recovery of weight for age was normal for their weight and predictions were accurate. The sequential estimates of composition indicated that although the relationship between fat and weight differed between individuals, at any given body weight above 32 kg compensating animals and controls had a similar composition. *Part I, Aust. J. Agric. Res., 26: 343 (1975).


1970 ◽  
Vol 74 (2) ◽  
pp. 357-362 ◽  
Author(s):  
T. W. Searle

SUMMARYTritiated water (TOH) space was determined in sixty-one sheep of known age (3 days to 18 months). Representative samples of the minced carcass were subsequently analysed to determine body composition (water, fat, protein, ash and energy). The regressions of the weight of the various body components on TOH space and body weight reported here gave equations suitable for prediction. These were similar to equations derived from published results for adults. Combining data on young sheep and adults gave broadly based equations that could be used to predict the body composition of healthy sheep of all ages from 3 days to adults.


1979 ◽  
Vol 10 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Thomas Aneblom ◽  
Gösta Persson

In this study the changes in water content in the unsaturated zone of a large esker at Tärnsjö have been measured with a combined gamma/neutron probe. Periods of heavy rainfall and intense snow-melting have resulted in infiltration events, which later have been traced as zones with high water content moving downwards in the unsaturated zone towards the groundwater table. The results indicate a velocity of the movement of such zones of about 1.5-3.0 m/month. These results are compared with those obtained by Andersen and Sevel (1974) from a study in Denmark, and with preliminary results from a study of the movement of tritiated water in the unsaturated zone of the Tärnsjö esker performed by Z. Dressie.


1998 ◽  
Vol 46 (5) ◽  
pp. 405 ◽  
Author(s):  
Philip C. Withers

Measurements of evaporative water loss (EWL; mg min-1) and resistance (R; sec cm-1) for various Australian frogs indicate three general allometric patterns: non-cocooned and non-‘waterproof’ frogs with EWL ∝ Mass0.30 and R independent of body mass at about 1–3 sec cm-1, cocooned frogs with EWL reduced about 50–200-fold and R about 50–200 sec cm-1, and ‘waterproof’ frogs with EWL reduced about 5–100- fold and R about 5–100 sec cm-1. Cocooned frogs have an exponential reduction in EWL and fairly linear increase in R over time, corresponding to the temporal addition of layers to the cocoon. The biophysical properties of cocoon are generally similar for various species, although there is some variation in both resistance per thickness (5–20 × 104 s cm-2) and diffusion coefficient (0.4–2.4 × 10 –5 cm2 s-1). The hygroscopic property of frog cocoon resembles that of mammalian stratum corneum, hair and wool, and mucopolysaccharides; there is a slight increase in water content of cocoon over a wide range of humidities but a very steep increase in water content and substantial hydration and swelling at >96% RH. This extreme hygroscopic behaviour of frog cocoon at very high RH may reflect less polymer cross-linking in frog cocoon and its high digestibility. The prevention of over-hydration of frog cocoon in vivo may be attributed to the restriction of high water content to only very high RH (>96%).


2018 ◽  
Vol 24 (8) ◽  
pp. 843-854 ◽  
Author(s):  
Weiguo Xu ◽  
Shujun Dong ◽  
Yuping Han ◽  
Shuqiang Li ◽  
Yang Liu

Hydrogels, as a class of materials for tissue engineering and drug delivery, have high water content and solid-like mechanical properties. Currently, hydrogels with an antibacterial function are a research hotspot in biomedical field. Many advanced antibacterial hydrogels have been developed, each possessing unique qualities, namely high water swellability, high oxygen permeability, improved biocompatibility, ease of loading and releasing drugs and structural diversity. In this article, an overview is provided on the preparation and applications of various antibacterial hydrogels. Furthermore, the prospects in biomedical researches and clinical applications are predicted.


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