508 research outputs found

    Capacity bounds for dense massive MIMO in a line-of-sight propagation environment

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    The use of large-scale antenna arrays grants considerable benefits in energy and spectral efficiency to wireless systems due to spatial resolution and array gain techniques. By assuming a dominant line-of-sight environment in a massive multiple-input multiple-output scenario, we derive analytical expressions for the sum-capacity. Then, we show that convenient simplifications on the sum-capacity expressions are possible when working at low and high signal-to-noise ratio regimes. Furthermore, in the case of low and high signal-to-noise ratio regimes, it is demonstrated that the Gamma probability density function can approximate the probability density function of the instantaneous channel sum-capacity as the number of served devices and base station antennas grows, respectively. A second important demonstration presented in this work is that a Gamma probability density function can also be used to approximate the probability density function of the summation of the channel's singular values as the number of devices increases. Finally, it is important to highlight that the presented framework is useful for a massive number of Internet of Things devices as we show that the transmit power of each device can be made inversely proportional to the number of base station antennas.20

    Dried brewers grains in growing rabbits: nutritional value and effects on performance

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    [EN] Two assays were carried out to determine i) the nutritional value of dried brewers’ grains and ii) the effects of inclusion of this ingredient in growing rabbit diets on animal performance and economic performance of the breeding unit. In the digestibility assay, a total of 28 male rabbits were distributed in 2 groups differing in the diet offered to animals: a reference diet (35.51% neutral detergent fibre and 16.50% crude protein [CP]) and a test diet (60% of reference diet and 40% of dried brewers grains). The dried brewers’ grain contained 37.9% of CP and 3371 kcal digestible energy/kg dry matter. In the performance study, 80 weaned rabbits (40 males and 40 females) were allotted at 40 d of age to 5 groups differing in the inclusion levels of dried brewers’ grains (0, 7, 14, 21 and 28%) from 40 d to 90 d of age. Inclusion of dried brewers’ grains did not affect the live weight at 90 d, the feed intake between 40 d and 90 d or the dressing percentage of rabbits (on average 223 g, 96 g/d and 51.3%, respectively). There was no effect of diet on the meat quality parameters (69.5% water holding capacity, 25.6% cooking loss, 3.4 kg/cm2 Warner-Bratzler shear force and pH 5.70) and inclusion levels above 14% reduced the feed cost (–18%; P<0.001), while inclusion above 21% improved net income (+32%; P<0.001). In conclusion, these results suggest that the use of dried brewers’ grains in diets for growing rabbits could improve the economic performance of the production system without impairing the animals’ performance.Lima, P.; Watanabe, P.; Cândido, R.; Ferreira, A.; Vieira, A.; Rodrigues, B.; Nascimento, G.... (2017). Dried brewers grains in growing rabbits: nutritional value and effects on performance. World Rabbit Science. 25(3):251-260. doi:10.4995/wrs.2017.6813.SWORD251260253Albuquerque, D. M. N., Lopes, J. B., Klein Junior, M. H., Merval, R. R., Silva, F. E. S., & Teixeira, M. P. F. (2011). Resíduo desidratado de cervejaria para suínos em terminação. Arquivo Brasileiro de Medicina Veterinária e Zootecnia, 63(2), 465-472. doi:10.1590/s0102-09352011000200026AOAC International. 2005. Official methods of analysis of Association Official Analytical Chemists International. AOAC, Arlington VA. USA.Briganó, M. V., Pacheco, G. D., Bridi, A. M., Oba, A., Fonseca, N. A. N., & Silva, C. A. da. (2008). Desempenho e características de carcaça de suínos submetidos a diferentes programas de restrição alimentar na fase dos 30 aos 118 kg. Revista Brasileira de Zootecnia, 37(8), 1398-1404. doi:10.1590/s1516-35982008000800009De Blas, J. C., Rodriguez, C. A., Bacha, F., Fernandez, R., & Abad-Guamán, R. (2015). Nutritive value of co-products derived from olivecake in rabbit feeding. World Rabbit Science, 23(4), 255. doi:10.4995/wrs.2015.4036Etchu K.A., Humbu M.E., Ndamukong K.J.N., Agbor E.B. 2012. Effect of varying levels of brewers' dried grain on the growth performance of weaner rabbits (Oryctolagus Cuniculus). Greener J. Agric. Sci., 2: 237-245.Fazano A.R.T., Zinsly C.F., Mattos W.R.S., Packer I.H. 1986. Digestibilidade e valor biológico da proteína da levedura seca (Saccharomyces spp.) e do farelo de soja para coelhos. Boletim de Indústria Animal, 46: 185-191.Lounaouci-Ouyaed G., Lakabi-ioualitene D., Berchiche M., Lebas F. 2008. Field beans and brewers grain as protein source for growing rabbits in Algeria: first results on growth and carcass quality. Nutrition and Digestive Physiology. In: 9th World Rabbit Congress, June 10-13, Verona, Italy. 723-728.Matterson L.D., Potter L.M., Stutz M.W., Singsen E.P. 1965. The metabolizable energy of feed ingredients for chickens. Storrs: University of Connecticut; Agricultural Experiment Station Research Report, 11: 11.National Research Council. 2007. Nutrient requirements of small ruminants: sheep, goats, cervids, and New World camelids. Washington, D.C.: National Academic Press, 292.Partridge G., Wyatt C. 1995. More flexibility with new generation of enzymes. World Poultry,11: 17-21.SAS 2000. SAS/STAT User's Guide (Release 6.12). SAS Inst. Inc., Cary NC, EUA.Villamide, M. J. (1996). Methods of energy evaluation of feed ingredients for rabbits and their accuracy. Animal Feed Science and Technology, 57(3), 211-223. doi:10.1016/0377-8401(95)00855-

    Manifestation of Chaos in Real Complex Systems: Case of Parkinson's Disease

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    In this chapter we present a new approach to the study of manifestations of chaos in real complex system. Recently we have achieved the following result. In real complex systems the informational measure of chaotic chatacter (IMC) can serve as a reliable quantitative estimation of the state of a complex system and help to estimate the deviation of this state from its normal condition. As the IMC we suggest the statistical spectrum of the non-Markovity parameter (NMP) and its frequency behavior. Our preliminary studies of real complex systems in cardiology, neurophysiology and seismology have shown that the NMP has diverse frequency dependence. It testifies to the competition between Markovian and non-Markovian, random and regular processes and makes a crossover from one relaxation scenario to the other possible. On this basis we can formulate the new concept in the study of the manifestation of chaoticity. We suggest the statistical theory of discrete non-Markov stochastic processes to calculate the NMP and the quantitative evaluation of the IMC in real complex systems. With the help of the IMC we have found out the evident manifestation of chaosity in a normal (healthy) state of the studied system, its sharp reduction in the period of crises, catastrophes and various human diseases. It means that one can appreciably improve the state of a patient (of any system) by increasing the IMC of the studied live system. The given observation creates a reliable basis for predicting crises and catastrophes, as well as for diagnosing and treating various human diseases, Parkinson's disease in particular.Comment: 20 pages, 8 figures, 3 tables. To be published in "The Logistic Map and the Route to Chaos: From the Beginnings to the Modern Applications", eds. by M. Ausloos, M. Dirickx, pp. 175-196, Springer-Verlag, Berlin (2006

    One Dimensional Chain with Long Range Hopping

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    The one-dimensional (1D) tight binding model with random nearest neighbor hopping is known to have a singularity of the density of states and of the localization length at the band center. We study numerically the effects of random long range (power-law) hopping with an ensemble averaged magnitude \expectation{|t_{ij}|} \propto |i-j|^{-\sigma} in the 1D chain, while maintaining the particle-hole symmetry present in the nearest neighbor model. We find, in agreement with results of position space renormalization group techniques applied to the random XY spin chain with power-law interactions, that there is a change of behavior when the power-law exponent σ\sigma becomes smaller than 2

    Evidence for eosinophil recruitment, leukotriene B4 production and mast cell hyperplasia following Toxocara canis infection in rats

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    It is well known that eosinophilia is a key pathogenetic component of toxocariasis. The objective of the present study was to determine if there is an association between peritoneal and blood eosinophil influx, mast cell hyperplasia and leukotriene B4 (LTB4) production after Toxocara canis infection. Oral inoculation of 56-day-old Wistar rats (N = 5-7 per group) with 1000 embryonated eggs containing third-stage (L3) T. canis larvae led to a robust accumulation of total leukocytes in blood beginning on day 3 and peaking on day 18, mainly characterized by eosinophils and accompanied by higher serum LTB4 levels. At that time, we also noted increased eosinophil numbers in the peritoneal cavity. In addition, we observed increased peritoneal mast cell number in the peritoneal cavity, which correlated with the time course of eosinophilia during toxocariasis. We also demonstrated that mast cell hyperplasia in the intestines and lungs began soon after the T. canis larvae migrated to these compartments, reaching maximal levels on day 24, which correlated with the complete elimination of the parasite. Therefore, mast cells appear to be involved in peritoneal and blood eosinophil infiltration through an LTB4-dependent mechanism following T. canis infection in rats. Our data also demonstrate a tight association between larval migratory stages and intestinal and pulmonary mast cell hyperplasia in the toxocariasis model

    Particle-Like Description in Quintessential Cosmology

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    Assuming equation of state for quintessential matter: p=w(z)ρp=w(z)\rho, we analyse dynamical behaviour of the scale factor in FRW cosmologies. It is shown that its dynamics is formally equivalent to that of a classical particle under the action of 1D potential V(a)V(a). It is shown that Hamiltonian method can be easily implemented to obtain a classification of all cosmological solutions in the phase space as well as in the configurational space. Examples taken from modern cosmology illustrate the effectiveness of the presented approach. Advantages of representing dynamics as a 1D Hamiltonian flow, in the analysis of acceleration and horizon problems, are presented. The inverse problem of reconstructing the Hamiltonian dynamics (i.e. potential function) from the luminosity distance function dL(z)d_{L}(z) for supernovae is also considered.Comment: 35 pages, 26 figures, RevTeX4, some applications of our treatment to investigation of quintessence models were adde
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