26,386 research outputs found
A Multistage Method for SCMA Codebook Design Based on MDS Codes
Sparse Code Multiple Access (SCMA) has been recently proposed for the future
generation of wireless communication standards. SCMA system design involves
specifying several parameters. In order to simplify the procedure, most works
consider a multistage design approach. Two main stages are usually emphasized
in these methods: sparse signatures design (equivalently, resource allocation)
and codebook design. In this paper, we present a novel SCMA codebook design
method. The proposed method considers SCMA codebooks structured with an
underlying vector space obtained from classical block codes. In particular,
when using maximum distance separable (MDS) codes, our proposed design provides
maximum signal-space diversity with a relatively small alphabet. The use of
small alphabets also helps to maintain desired properties in the codebooks,
such as low peak-to-average power ratio and low-complexity detection.Comment: Submitted to IEEE Wireless Communication Letter
Quantitative Proteomic Analysis Reveals Changes in the Benchmark Corynebacterium pseudotuberculosis Biovar Equi Exoproteome after Passage in a Murine Host
Corynebacterium pseudotuberculosis biovar equi is the etiologic agent of ulcerative lymphangitis. To investigate proteins that could be related to the virulence of this pathogen, we combined an experimental passage process using a murine model and high-throughput proteomics with a mass spectrometry, data-independent acquisition (LC-MSE) approach to identify and quantify the proteins released into the supernatants of strain 258_equi. To our knowledge, this approach allowed characterization of the exoproteome of a C. pseudotuberculosis equi strain for the first time. Interestingly, the recovery of this strain from infected mouse spleens induced a change in its virulence potential, and it became more virulent in a second infection challenge. Proteomic screening performed from culture supernatant of the control and recovered conditions revealed 104 proteins that were differentially expressed between the two conditions. In this context, proteomic analysis of the recovered condition detected the induction of proteins involved in bacterial pathogenesis, mainly related to iron uptake. In addition, KEGG enrichment analysis showed that ABC transporters, bacterial secretion systems and protein export pathways were significantly altered in the recovered condition. These findings show that secretion and secreted proteins are key elements in the virulence and adaptation of C. pseudotuberculosis. Collectively, bacterial pathogenesis-related proteins were identified that contribute to the processes of adherence, intracellular growth and evasion of the immune system. Moreover, this study enhances our understanding of the factors that may influence the pathogenesis of C. pseudotuberculosis.Fil: Marques Da Silva, Wanderson. Universidade Federal de Minas Gerais. Instituto de CiĂȘncias BiolĂłgicas; Brasil. Institut National de la Recherche Agronomique; Francia. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; ArgentinaFil: Carvalho, Rodrigo D. De Oliveira. Universidade Federal de Minas Gerais. Instituto de CiĂȘncias BiolĂłgicas; BrasilFil: Dorella, Fernanda A.. Universidade Federal de Minas Gerais; BrasilFil: Folador, Edson L.. Universidade Federal da ParaĂba. Centro de Biotecnologia; BrasilFil: Souza, Gustavo H. M. F.. Waters Corporation; BrasilFil: Pimenta, Adriano M. C.. Universidade Federal de Minas Gerais. Instituto de CiĂȘncias BiolĂłgicas; BrasilFil: Figueiredo, Henrique C. P.. Universidade Federal de Minas Gerais; BrasilFil: Le Loir, Yves. Institut National de la Recherche Agronomique; FranciaFil: Silva, Artur. Universidade Federal do ParĂĄ; BrasilFil: Azevedo, Vasco. Universidade Federal de Minas Gerais. Instituto de CiĂȘncias BiolĂłgicas; Brasi
Using mixed methods for analysing culture : The Cultural Capital and Social Exclusion project
This paper discusses the use of material generated in a mixed method investigation into cultural tastes and practices, conducted in Britain from 2003 to 2006, which employed a survey, focus groups and household interviews. The study analysed the patterning of cultural life across a number of fields, enhancing the empirical and methodological template provided by Bourdieuâs Distinction. Here we discuss criticisms of Bourdieu emerging from subsequent studies of class, culture and taste, outline the arguments related to the use of mixed methods and present illustrative results from the analysis of these different types of data. We discuss how the combination of quantitative and qualitative methods informed our analysis of cultural life in contemporary Britain. No single method was able to shed light on all aspects of our inquiry, lending support to the view that mixing methods is the most productive strategy for the investigation of complex social phenomena
Solving Linux Upgradeability Problems Using Boolean Optimization
Managing the software complexity of package-based systems can be regarded as
one of the main challenges in software architectures. Upgrades are required on
a short time basis and systems are expected to be reliable and consistent after
that. For each package in the system, a set of dependencies and a set of
conflicts have to be taken into account. Although this problem is
computationally hard to solve, efficient tools are required. In the best
scenario, the solutions provided should also be optimal in order to better
fulfill users requirements and expectations. This paper describes two different
tools, both based on Boolean satisfiability (SAT), for solving Linux
upgradeability problems. The problem instances used in the evaluation of these
tools were mainly obtained from real environments, and are subject to two
different lexicographic optimization criteria. The developed tools can provide
optimal solutions for many of the instances, but a few challenges remain.
Moreover, it is our understanding that this problem has many similarities with
other configuration problems, and therefore the same techniques can be used in
other domains.Comment: In Proceedings LoCoCo 2010, arXiv:1007.083
Hyper-volume evolutionary algorithm
We propose a multi-objective evolutionary algorithm (MOEA), named the Hyper-volume Evolutionary Algorithm (HVEA). The algorithm is characterised by three components. First, individual fitness evaluation depends on the current Pareto front, specifically on the ratio of its dominated hyper-volume to the current Pareto front hyper-volume, hence giving an indication of how close the individual is to the current Pareto front. Second, a ranking strategy classifies individuals based on their fitness instead of Pareto dominance, individuals within the same rank are non-guaranteed to be mutually non-dominated. Third, a crowding assignment mechanism that adapts according to the individualâs neighbouring area, controlled by the neighbouring area radius parameter, and the archive of non-dominated solutions. We perform extensive experiments on the multiple 0/1 knapsack problem using different greedy repair methods to compare the performance of HVEA to other MOEAs including NSGA2, SEAMO2, SPEA2, IBEA and MOEA/D. This paper shows that by tuning the neighbouring area radius parameter, the performance of the proposed HVEA can be pushed towards better convergence, diversity or coverage and this could be beneficial to different types of problems
Two new Eburiini from Mexico (Coleoptera, Cerambycidae, Cerambycinae)
Two new species of Eburiini (Coleoptera, Cerambycidae, Cerambycinae) are described from Mexico (Guerrero): Susuacanga boteroi; and Eburia (Eburia) girouxae. Both are included in previous keys
A new species of Heteropalpini from Peru (Coleoptera: Cerambycidae: Disteniinae)
Pseudocometes harrisoni sp. nov. is described from Peru. A key to species of Pseudocometes is provided
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