144 research outputs found

    3D Millimeter-Wave Peer-to-Peer Networks With Boundary Located Destination

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    This letter presents a theoretical analysis for estimating the coverage probability and the average link capacity of an interfered peer-to-peer millimeter-wave communication, when the destination lies at the boundary of a three-dimensional cell. The proposed model provides closed-form expressions for the statistics of the desired and undesired signal powers, by accounting for the impact of directional antenna gains, path-loss attenuation, mid-scale fading, interference, and noise

    New Fourier Transform Approach to the Synthesis of Shaped Patterns by Linear Antenna Arrays

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    A new Fourier Transform (NFT) approach is developed for the synthesis of shaped patterns radiated by linear antenna arrays. The proposed method exploits in an innovative way the FT relation between the source distribution and the radiated pattern. Precisely, the finite dimension of real sources is firstly taken into account by using the sampling theorem to approximate the desired pattern as a band-limited function. It is this step that allows one to obtain an important performance improvement. Then, a continuous source is evaluated from the approximate desired pattern to finally obtain the element excitations. Numerical examples validate the method

    Growth of Wild Gilthead Seabream (Sparus aurata L.) Juveniles for Organic Aquaculture

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    The majority of organic marine fish farms currently begin the production cycle with non-organic juveniles from conventional hatcheries, permitted by the European Regulation on organic fish origin (EC 710/2009) until the end of 2016. Wild juvenile gilthead seabream (Sparus aurata) from coastal lagoons and hatcheries were experimentally reared under organic conditions, in order (1) to investigate differences in fillet lipid content and fatty acids composition, and (2) to propose a possible future source of juveniles destined for organic aquaculture. Wild juveniles were readily distinguishable by their fatty acid signature, showing significantly higher ratio levels of n-3 polyunsaturated fatty acids and n-3/n-6. Fillet lipid composition of organically fed wild S. aurata juveniles was preferable to that from domesticated juveniles. These results seem promising for organic aquaculture, where fish feed is more environmentally sustainable but is of lower nutritional qualit

    skeletal muscle expression analysis of fat metabolism genes in pig

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    Fat content and backfat thickness are important polygenic parameters influencing meat quality and carcass traits in pigs. Up to now, there is a lack of knowledge on the expression level of the genes encoding for enzymes involved in fatty acid metabolism in porcine skeletal muscle. In the present study we analysed, by quantitative real time PCR, the expression of three genes, acetyl-CoA carboxylase (ACACA), ATP citrate lyase (ACL) and fatty acid synthase (FASN) in skeletal muscle tissue samples of Italian Large White and Italian Duroc pigs with divergent breeding values for backfat thickness or visible intramuscular fat. Significant differences of the expression level for ACACA gene (P=0.04) and for ACL gene (P=0.02) were observed between the two breeds, comparing the samples selected for backfat thickness trait. The expression analysis of FASN gene in the samples with different genotype at the SNP c.265C>T showed that the TT genotype presented the lowest values in both breeds. The differences observed between breeds should be further considered to investigate the putative involvement of these genes on fat deposition traits. - Ricerca e analisi di espressione di geni candidati per la deposizione di grasso nella carne suina in razze con diversa attitudine alla deposizione di grasso intramuscolare

    On the use of elo rating on harness racing results in the genetic evaluation of trotter

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    The official results of trotters in Italian harness racings have been used to get AM-BLUP estimates of genetic parameters, EBVs and rTI of three groups of traits: speed (racing time, annual best time, best time in career between 2- and 5-year old), earnings (earnings/start, annual earnings, total earnings between 2- and 5- year old) and Elo system traits (underlying performance and final rating). The Elo system has been used for half a century in chess players rating, and it has been modified and fitted to several games and sports: it has already been used for genetic evaluation of sport horses in France. The highest heritability estimates in each group of traits have been found for best time (.430±.014), total earnings (.271±.013) and Elo final rating (.270±.008). The choice of "k", the Elo ratings updating factor, did not show a key role in affecting the results. The underlying performance heritability and repeatability have been estimated .159±.004 and .420±.007 respectively. The Elo-based systems proved to be very promising in objectively evaluating trotters

    Role of the product \u3bb\u2032(0)\u3c1\u2032(1) in determining ldpc code performance

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    The objective of this work is to analyze the importance of the product \u3bb\u2032 (0)\u3c1\u2032 (1) in determining low density parity check (LDPC) code performance, as far as its influence on the weight distribution function and on the decoding thresholds. This analysis is based on the 2006 paper by Di et al., as far as the weight distribution function is concerned, and on the 2018 paper by Vatta et al., regarding the LDPC decoding thresholds. In particular, the first paper Di et al. analyzed the relation between the above mentioned product and the minimum weight of an ensemble of random LDPC codewords, whereas in the second some analytical upper bounds to the LDPC decoding thresholds were determined. In the present work, besides analyzing the performance of an ensemble of LDPC codes through the outcomes of Di et al.\u2019s 2006 paper, we give the relation between one of the upper bounds found in Vatta et al.\u2019s 2018 paper and the above mentioned product \u3bb\u2032 (0)\u3c1\u2032 (1), thus showing its role in also determining an upper bound to LDPC decoding thresholds

    A new accurate approximation of the Gaussian Q-function with relative error less than 1 thousandth in a significant domain

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    The approximations of the Gaussian Q-function found in the literature have been often developed with the goal of obtaining high estimation accuracies in deriving the error probability for digital modulation schemes. Unfortunately, the obtained mathematical expressions are often too complex, even difficultly tractable. A new approximation for the Gaussian Q-function is presented in the form of the standard normal density multiplied by a rational function. The rational function is simply a linear combination of the first 5 integer negative powers of the same term, linear in x, using only 4 decimal constants. In this paper we make some considerations about the significant interval where to consider the Q-function in telecommunication theory. The relative error in absolute value of the given approximation is less than 0.06% in the considered significant interval

    Performance Study of a Class of Irregular Near Capacity Achieving LDPC Codes

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    This paper investigates the performance of a class of irregular low-density parity-check (LDPC) codes through a recently published low complexity upper bound on their beliefpropagation decoding thresholds. Moreover, their performance analysis is carried out through a recently published algorithmic method, presented in Babich et al. 2017 paper. In particular, the class considered is characterized by variable node degree distributions λ(x) of minimum degree i1 > 2: being, in this case, λ0(0) = λ2 = 0, this is useful to design LDPC codes presenting a linear minimum distance growth with the block length with probability 1, as shown in Di et al.'s 2006 paper. These codes unfortunately cannot reach capacity under iterative decoding, since the achievement of capacity requires λ2 ≠ 0. However, in this latter case, the block error probability might converge to a constant, as shown in the aforementioned paper

    Whole Genome Sequencing Provides Information on the Genomic Architecture and Diversity of Cultivated Gilthead Seabream (Sparus aurata) Broodstock Nuclei

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    The gilthead seabream (Sparus aurata) is a species of relevance for the Mediterranean aquaculture industry. Despite the advancement of genetic tools for the species, breeding programs still do not often include genomics. In this study, we designed a genomic strategy to identify signatures of selection and genomic regions of high differentiation among populations of farmed fish stocks. A comparative DNA pooling sequencing approach was applied to identify signatures of selection in gilthead seabream from the same hatchery and from different nuclei that had not been subjected to genetic selection. Identified genomic regions were further investigated to detect SNPs with predicted high impact. The analyses underlined major genomic differences in the proportion of fixed alleles among the investigated nuclei. Some of these differences highlighted genomic regions, including genes involved in general metabolism and development already detected in QTL for growth, size, skeletal deformity, and adaptation to variation of oxygen levels in other teleosts. The obtained results pointed out the need to control the genetic effect of breeding programs in this species to avoid the reduction of genetic variability within populations and the increase in inbreeding level that, in turn, might lead to an increased frequency of alleles with deleterious effects

    A Simple Blass Matrix Design Strategy for Multibeam Arbitrary Linear Antenna Arrays

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    Multibeam antenna arrays are currently recognized as one of the enabling technologies for the next-generation communication standards. One of the key components of these systems is the beamforming network (BFN) that implements the array element excitations. This article addresses this issue by presenting a novel strategy to realize an analog feeding network, which allows an arbitrary linear array (LA) to radiate multiple arbitrary beams. In particular, an iterative procedure is conceived to design a Blass matrix using an identical directional coupler for all nodes, resulting in a very simple structure suitable for large-scale production. Two applications with arbitrary directions are illustrated as proofs-of-concept for the developed architecture: a dual-beam configuration with a null involving an aperiodic LA, and a four-beam configuration involving a periodic LA. For this second application, the effectiveness of the proposed solution is further verified by full-wave simulations and experimental measurements carried out on a fabricated prototype
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