The new iterative nonuniform polar quantization method is presented in this paper. The decision levels and the reconstruction levels are determined by this iterative method as well as the number of ...points on levels. The quantization mean-squared error (MSE) is used as the criterion for optimization. We also present the exact method for the error probability determination per signal constellation symbol, which is obtained by this quantization method. The error probability for nonequiprobable symbols transmission through a channel with the additive Gaussian noise is also computed.
Poultry rearing systems have been the focus of scientific research for many years as a result of consumer demand for high-quality products and legal poultry welfare requirements. Given these ...requirements, the following study was carried out as a comparative review of the results obtained by different authors on the effect of rearing systems on productive traits (growth, feed conversion and mortality) and meat quality traits (dressing percentage, yield and percentage of primal cuts, and chemical composition of meat) in broilers. Most authors reported a lower final body weight and poorer feed conversion efficiency in free-range systems compared to intensive rearing. Conversely, better meat quality traits, most notably in terms of chemical composition of meat, were observed in non-intensive and organic broilers. The above traits showed differences within the same rearing system, due to the effect of a range of genetic and non-genetic factors. In view of the above, it is hoped that the following review on the use of different rearing systems in broiler meat production can serve as a tool in determining the future direction of research as well as an indicator of its practical applications.
Laying hen rearing systems have been the focus of scientific research for many years. Over the last few decades, new laying hen rearing systems have been rapidly introduced in an effort to harmonise ...poultry health and welfare with consumer, producer, industry and environmental demands. Given the above situation, the subject matter of this paper was a comparative review of the results obtained by different authors on the effect of rearing system on productive traits (egg production and mortality) and egg quality characteristics (egg weight, proportions of main egg parts, Haugh units, yolk colour and carotenoids) in laying hens. Although productive performance in alternative systems is often lower compared to conventional, intensive layers, eggs from alternative systems have been proven in numerous studies to have better nutritional properties. Moreover, research results indicate differences within rearing systems. In view of this, this overview of the literature on the use of different rearing systems in table egg production can serve as a tool in determining the future direction of research as well as an indicator of its practical application.
We present the results of spectroscopic, narrow-band and X-ray observations of a z=2.30 protocluster in the field of the QSO HS 1700+643. Using a sample of BX/MD galaxies, which are selected to be at ...z~2.2-2.7 by their rest-frame ultraviolet colours, we find that there are 5 protocluster AGN which have been identified by characteristic emission-lines in their optical/near-IR spectra; this represents an enhancement over the field significant at ~98.5 per cent confidence. Using a ~200 ks Chandra/ACIS-I observation of this field we detect a total of 161 X-ray point sources to a Poissonian false-probability limit of 4x10^{-6} and identify 8 of these with BX/MD galaxies. Two of these are spectroscopically confirmed protocluster members and are also classified as emission-line AGN. When compared to a similarly selected field sample the analysis indicates this is also evidence for an enhancement of X-ray selected BX/MD AGN over the field, significant at ~99 per cent confidence. Deep Lya narrow-band imaging reveals that a total of 4/123 Lya emitters (LAEs) are found to be associated with X-ray sources, with two of these confirmed protocluster members and one highly likely member. We do not find a significant enhancement of AGN activity in this LAE sample over that of the field (result significant at only 87 per cent confidence). The X-ray emitting AGN fractions for the BX/MD and LAE samples are found to be 6.9_{-4.4}^{+9.2} and 2.9_{-1.6}^{+2.9} per cent, respectively, for protocluster AGN with L_{2-10 keV}>4.6x10^{43} erg s^{-1} at z=2.30. These findings are similar to results from the z=3.09 protocluster in the SSA 22 field found by Lehmer et al. (2009), in that both suggest AGN activity is favoured in dense environments at z>2.
This paper presents the analysis of different types of Laplace source signal quantizations. The original method for source quantization minimising the entropy under the mean-squared quantization ...error constraint is presented in the paper. The procedure for choosing constant /spl mu/ of /spl mu/ logarithmic compression law is proposed. The procedure for correct separation of the source coding from the channel one, i.e. the procedure for error probability contribution determination in the total mean-squared error (TMSE) is proposed.
Alternative laying hen rearing systems have been rapidly introduced into poultry production in an effort to harmonise poultry health and welfare with consumer, producer, industry and environmental ...demands. They are an integral part of modern egg production. Husbandry systems for keeping laying hens have an impact on, inter alia, the chemical composition of eggs. The subject matter of this study is a comparative review of the results obtained by different authors on the effect of rearing system on chemical composition (proteins, lipids, cholesterol, vitamins and fatty acids content) and hygienic conditions of eggs from different rearing systems of laying hens. Eggs from these laying hen rearing systems have been proven by a large body of literature data to have better nutritional properties. Moreover, the results analysed also indicate differences within rearing systems. Rearing systems also have an influence on hygienic and microbiological quality of eggs. In view of the above, this comparable overview of the literature on the use of different rearing systems in table egg production can serve as a tool in determining the future direction of research as well as an indicator of its practical application.
The effect of sex and the rearing system on carcass composition and cut yields of broiler chickens Bogosavljevic-Boskovic, S.(University of Kragujevac, Cacak (Serbia and Montenegro). Dept. of Animal Husbandry) E-mail:sbb@tfc.kg.ac.yu; Kurcubic, V.(University of Kragujevac, Cacak (Serbia and Montenegro). Dept. of Animal Husbandry); Petrovic, M.D.(University of Kragujevac, Cacak (Serbia and Montenegro). Dept. of Animal Husbandry) ...
Czech Journal of Animal Science,
01/2006, Letnik:
51, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Meat quality of chicken broilers (hybrid Hybro G) reared in two different non-industrial indoor systems, extensive and free-range one, was analysed. The two rearing systems used did not have any ...effect on the proportions of major carcass parts and abdominal fat. Significantly heavier carcasses (on the 56th day of fattening) were recorded in males than in females. The drumstick proportion was significantly higher in males than in females. The interaction between the investigated effects (sex and rearing system) did not exert any significant effect on the proportions of major carcass parts and abdominal fat. Average muscle proportions in drumsticks and thighs were significantly higher in females than in males, whereas average bone proportions in breasts, drumsticks and thighs were significantly higher in males than in females.
Intracranial schwannomas are benign tumors that arise from Schwann cells. Since it is well known that optic and olfactory nerves do not have a Schwann cell sheath, schwannoma should not develop from ...these nerves. We report a very unusual case of a 73-year-old female who presented with generalized seizures and had radiological features of an intracranial aneurysm. Additional imaging showed an extracerebral mass 2.5 x 2.0 cm in size, which most likely corresponded to a meningioma. It was resected in total. Subsequent histological analysis revealed that the tumor was in fact ancient schwannoma WHO grade I. Only about 41 case of olfactory schwannoma have been reported in the literature. Olfactory groove schwannomas are extremely rare tumors, occurring less frequently than any other intracranial nerve schwannoma. As in this case, the schwannoma should be included in the differential diagnosis of the anterior cranial fossa tumor. Further research on the pathogenesis and the origin of olfactory groove schwannoma is needed.
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