348 research outputs found

    Variations of some blood parameters in rabbit reared under different environmental conditions

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    High environmental temperature induces physiological stress in rabbits leading to production losses, also because of their quite poor thermoregulation ability. Some consequences of heat stress affect digestive system functions, with impaired appetite, growth and feed conversion, but also with increased disease incidence. These effects can also reflect on the levels of some blood metabolites. Relatively few experimental works are available on the effects of high environmental temperature on the rabbit metabolic profile reared in commercial farms. The aim of this study was to study, in separate experiments, the effects of "fresh" spring and of "hot" summer temperatures on rabbits performance with particular attention to the behaviour of some metabolic parameters and of some aspects of the functionality of the digestive system

    Reading a GEM with a VLSI pixel ASIC used as a direct charge collecting anode

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    In MicroPattern Gas Detectors (MPGD) when the pixel size is below 100 micron and the number of pixels is large (above 1000) it is virtually impossible to use the conventional PCB read-out approach to bring the signal charge from the individual pixel to the external electronics chain. For this reason a custom CMOS array of 2101 active pixels with 80 micron pitch, directly used as the charge collecting anode of a GEM amplifying structure, has been developed and built. Each charge collecting pad, hexagonally shaped, realized using the top metal layer of a deep submicron VLSI technology is individually connected to a full electronics chain (pre-amplifier, shaping-amplifier, sample and hold, multiplexer) which is built immediately below it by using the remaining five active layers. The GEM and the drift electrode window are assembled directly over the chip so the ASIC itself becomes the pixelized anode of a MicroPattern Gas Detector. With this approach, for the first time, gas detectors have reached the level of integration and resolution typical of solid state pixel detectors. Results from the first tests of this new read-out concept are presented. An Astronomical X-Ray Polarimetry application is also discussed.Comment: 11 pages, 14 figures, presented at the Xth Vienna Conference on Instrumentation (Vienna, February 16-21 2004). For a higher resolution paper contact [email protected]

    Genetic and environmental influences on in vitro digestibility of alfalfa

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    To study the relationships between in vitro NDF or true dry matter digestibility (NDFD and IVTDMD) and forage fibre content, 95 alfalfa samples from 5 cultivars grown in 3 different locations and from different cuts were analysed for fibre fractions and evaluated for NDFD and IVTDMD. NDFD was mainly influenced by order of cut and age of the fields. The multifoliate cultivar controlled did not appear to differ for fibre composition and NDFD from the other ones. Fibre fractions contents explained a large part of the difference in NDFD and IVTDMD, and no significant differences in this relationships appeared for first-cut vs. aftermath forage. The best predictive equation of NDFD from fibre factions was: NDFD = 73.61 -0.62 * NDF (% DM) – 56.33 * ADL/NDF (R2=0.39). Variations in fibre content and quality do not completely explain differences in NDFD suggesting the interference of other factors that are worth to be better studied

    In vitro digestibility of field pea as influenced by processing methods

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    Field pea meals exposed to different treatments (flaking, extrusion, expansion, dry heating at 150°C/15' or 30', dry heating at 150°C/30' after addition of 1% of xylose, 4% NaOH addition, microwave irradiation at 800 W for 6' or 9') were controlled for their 6 and 24 hours in vitro fermentability by the gas production (GP) technique. Flaking and extrusion accelerated initial fermentation but tended to reduce 24h GP, whereas dry heating and microwaves mainly improved final gas volume, but NaOH had the opposite effect. Apparent dry matter digestion at 6h was lowered by dry heating, NaOH addition and the shorter microwave irradiation. Xylose addition did not substantially change the effects of dry heating, but lowered the initial disappearance. Ammonia concentration was in general lowered by the treatments, suggesting a reduction in protein degradability but also a possible higher microbial uptake for protein synthesis. Microwave irradiation had limited effects on all the parameters. Dry heating, with or without xylose addition, seems interesting to increase rumen escaping protein fraction without accelerating starch fermentation that could expose to higher risks of rumen acidosis

    Solvent-free microwave extraction of essential oil from aromatic herbs: From laboratory to pilot and industrial scale

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    Solvent-free microwave extraction (SFME) has been proposed as a green method for the extraction of essential oil from aromatic herbs that are extensively used in the food industry. This technique is a combination of microwave heating and dry distillation performed at atmospheric pressure without any added solvent or water. The isolation and concentration of volatile compounds is performed in a single stage. In this work, SFME and a conventional technique, hydro-distillation HD (Clevenger apparatus), are used for the extraction of essential oil from rosemary (Rosmarinus officinalis L.) and are compared. This preliminary laboratory study shows that essential oils extracted by SFME in 30 min were quantitatively (yield and kinetics profile) and qualitatively (aromatic profile) similar to those obtained using conventional hydro-distillation in 2 h. Experiments performed in a 75 L pilot microwave reactor prove the feasibility of SFME up scaling and potential industrial applications

    Single-shot X-ray phase-contrast computed tomography with non-microfocal laboratory sources

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    We present a method that enables performing x-ray phase-contrast imaging (XPCI) computed tomography with a laboratory setup using a single image per projection angle, eliminating the need to move optical elements during acquisition. Theoretical derivation of the method is presented, and its validity conditions are provided. The object is assumed to be quasihomogeneous, i.e., to feature a ratio between the refractive index and the linear attenuation coefficient that is approximately constant across the field of view. The method is experimentally demonstrated on a plastics phantom and on biological samples using a continuous rotation acquisition scheme achieving scan times of a few minutes. Moreover, we show that such acquisition times can be further reduced with the use of a high-efficiency photon-counting detector. Thanks to its ability to substantially simplify the image-acquisition procedure and greatly reduce collection times, we believe this method represents a very important step towards the application of XPCI to real-world problems

    Dietary supplementation of garlic and rosemary: effects on colour stability and lipid oxidation in lamb meat

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    The colour of fresh meat is an important criterion consumers take into consideration when purchasing meat. Meat colour depends on the occurrence of chemical and microbial deterioration processes. The role of vitamin E and other antioxidants on ruminant meat colour stability and prevention of lipid oxidation has been widely investigated (Macit et al., 2003; Realini et al., 2004). Many natural herbs and plant extracts exert antioxidant effects such as garlic (Yin and Cheng, 2003) and rosemary (Sánchez-Escalante et al., 2001). Their use as additives for animal feeding may be a valid alternative to synthetic antioxidants since they show beneficial effects also on animal welfare and other physiological functions (Tedesco, 2001). The aim of this study was to evaluate whether garlic and rosemary dietary supplementation as compared with vitamin E affects lamb meat colour and lipid stability during storage

    The effect of parity number on the metabolism, inflammation, and oxidative status of dairy sheep during the transition period.

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    The objective of this study was to evaluate whether dairy sheep during the transition period are affected by their parity numbers with regard to (1) body weight (BW), body condition score (BCS), and production performance (milk yield and composition) and (2) metabolic, inflammation, and stress biomarkers. For this purpose, 30 Sarda dairy ewes [15 primiparous (PRP) and 15 multiparous (MUP) ewes] were recruited on d 90 of gestation. Each group was homogeneous according to age, BW, and BCS. Sampling was carried out at -60, -30, -7, 0, +30, and +60 d from lambing. The MUP ewes showed a higher BW (46.32 vs. 38.71 kg) and larger litter size (1.45 vs. 1.06 kg) but a lower BCS (2.47 vs. 2.70) than the PRP ewes. Furthermore, the MUP ewes had lower concentrations of glucose (3.49 vs. 4.27 mol/L), cholesterol (1.63 vs. 1.81 mmol/L), free fatty acids (0.47 vs. 0.62 mmol/L), and triglycerides (0.22 vs. 0.25 mmol/L) compared with PRP ewes. With regard to inflammation and oxidative stress parameters, the PRP group had higher haptoglobin (0.48 vs. 0.18 g/L) and paraoxonase (187.90 vs. 152.11 U/L) activity than the MUP group. Overall, the MUP ewes were characterized by greater milk production performance and greater feed intake, resulting in a better energy balance, than the PRP ewes. Interestingly, these findings highlighted a different metabolic and inflammatory response over the transition period between PRP and MUP ewes, with the latter displaying lower concentrations of inflammatory-related biomarkers

    Energy characterization of Pixirad-1 photon counting detector system

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    This work is focused on the characterization of the Pixirad-1 detector system from the spectroscopic point of view. An energy calibration has been carried out using different X-ray sources such as fluorescence lines, synchrotron radiation and radioactive elements. The energy resolution has been measured as function of the energy and the results have been compared with theoretical estimation. Last, the charge sharing fraction has been evaluated by exploiting the monochromatic energy of the Elettra synchrotron beam
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