1,219 research outputs found
Quantifying Equivocation for Finite Blocklength Wiretap Codes
This paper presents a new technique for providing the analysis and comparison
of wiretap codes in the small blocklength regime over the binary erasure
wiretap channel. A major result is the development of Monte Carlo strategies
for quantifying a code's equivocation, which mirrors techniques used to analyze
normal error correcting codes. For this paper, we limit our analysis to
coset-based wiretap codes, and make several comparisons of different code
families at small and medium blocklengths. Our results indicate that there are
security advantages to using specific codes when using small to medium
blocklengths.Comment: Submitted to ICC 201
Low-Complexity Equalisers for Offset Constellations in Massive MIMO Schemes
This work was supported in part by the European Regional Development Fund (FEDER), through the Competitiveness and Internationalization Operational Program of the Portugal 2020 Framework, in part by the Regional OP Centro under Grant POCI-01-0145-FEDER-030588, in part by the Regional OP Lisboa under Grant Lisboa-01-0145-FEDER-03058, in part by the FCT/MEC through national funds of MASSIVE5G Project under Grant SAICT-45-2017-02 and PES3N Project under Grant 2018-SAICT-45-2017-POCI-01-0145-FEDER-030629, in part by the UID/EEE/50008/2019 Project, and in part by the FCT Ph.D. under Grant SFRH/BD/108522/2015.Massive multi-input-multi-output (m-MIMO) schemes require low-complexity implementations at both the transmitter and the receiver side, especially for systems operation at millimeter wave (mmWave) bands. In this paper, we consider the use of offset constellations in m-MIMO systems operating at mmWave frequencies. These signals are designed to have either an almost constant envelope or be decomposed as the sum of constant-envelope signals, making them compatible with strongly nonlinear power amplifiers, which can have low-implementation complexity and high amplification efficient, making them particularly interesting for mmWave communications. We design and evaluate low-complexity frequency-domain receivers for offset signals. It is shown that the proposed receivers can have excellent performance/complexity trade-offs in m-MIMO scenarios, making them particularly interesting for future wireless systems operating at mmWave bands.publishersversionpublishe
Comportamento do herbicida hexazinone em área de recarga do aqüífero Guarani cultivada com cana-de-açúcar
São Paulo state (Brazil) has an important area of sugarcane production, mainly for obtaining alcohol and sugar, where there is an intensive use of pesticides. An important recharge zone of Guarani aquifer, with supplies water for the local population, is located at Ribeirão Preto city, so the local behavior of pesticides must be investigated. The GUS index was obtained by using the paramenters Koc and half-life for hezazinone herbicide, determinated in representative soil of this region. This study has demonstrated that there is potential risks of hexazinone leaching to ground water, indicating that this herbicide must be monitored in ground water
A comparison of two distinct murine macrophage gene expression profiles in response to Leishmania amazonensis infection
<p>Abstract</p> <p>Background</p> <p>The experimental murine model of leishmaniasis has been widely used to characterize the immune response against <it>Leishmania</it>. CBA mice develop severe lesions, while C57BL/6 present small chronic lesions under <it>L. amazonensis </it>infection. Employing a transcriptomic approach combined with biological network analysis, the gene expression profiles of C57BL/6 and CBA macrophages, before and after <it>L. amazonensis </it>infection in vitro, were compared. These strains were selected due to their different degrees of susceptibility to this parasite.</p> <p>Results</p> <p>The genes expressed by C57BL/6 and CBA macrophages, before and after infection, differ greatly, both with respect to absolute number as well as cell function. Uninfected C57BL/6 macrophages express genes involved in the deactivation pathway of macrophages at lower levels, while genes related to the activation of the host immune inflammatory response, including apoptosis and phagocytosis, have elevated expression levels. Several genes that participate in the apoptosis process were also observed to be up-regulated in C57BL/6 macrophages infected with <it>L. amazonensis</it>, which is very likely related to the capacity of these cells to control parasite infection. By contrast, genes involved in lipid metabolism were found to be up-regulated in CBA macrophages in response to infection, which supports the notion that <it>L. amazonensis </it>probably modulates parasitophorous vacuoles in order to survive and multiply in host cells.</p> <p>Conclusion</p> <p>The transcriptomic profiles of C57BL/6 macrophages, before and after infection, were shown to be involved in the macrophage pathway of activation, which may aid in the control of <it>L. amazonensis </it>infection, in contrast to the profiles of CBA cells.</p
A New Mouse Model for Marfan Syndrome Presents Phenotypic Variability Associated with the Genetic Background and Overall Levels of Fbn1 Expression
Marfan syndrome is an autosomal dominant disease of connective tissue caused by mutations in the fibrillin-1 encoding gene FBN1. Patients present cardiovascular, ocular and skeletal manifestations, and although being fully penetrant, MFS is characterized by a wide clinical variability both within and between families. Here we describe a new mouse model of MFS that recapitulates the clinical heterogeneity of the syndrome in humans. Heterozygotes for the mutant Fbn1 allele mgΔloxPneo, carrying the same internal deletion of exons 19–24 as the mgΔ mouse model, present defective microfibrillar deposition, emphysema, deterioration of aortic wall and kyphosis. However, the onset of a clinical phenotypes is earlier in the 129/Sv than in C57BL/6 background, indicating the existence of genetic modifiers of MFS between these two mouse strains. In addition, we characterized a wide clinical variability within the 129/Sv congenic heterozygotes, suggesting involvement of epigenetic factors in disease severity. Finally, we show a strong negative correlation between overall levels of Fbn1 expression and the severity of the phenotypes, corroborating the suggested protective role of normal fibrillin-1 in MFS pathogenesis, and supporting the development of therapies based on increasing Fbn1 expression
Comprovação empirica de uma medida relacionada ao excessivo consumo de álcool em Brasileiros
El consumo de alcohol entre universitarios ha sido un problema determinante para las relaciones interpersonales y el desarrollo académico, pero también un problema que trae un perjuicio social, económico y de salud. Las medidas han surgido y sugerido la reevaluación de otras para identificar el fenómeno del consumo de alcohol. Sin embargo, el Alcohol Use Disorders Identification Test (AUDIT) todavía ha sido el instrumento más utilizado en estudios en el mundo, el cual se ha revelado consistente. El presente estudio tiene como objetivo evaluar la consistencia interna y factorial del AUDIT en universitarios en diferentes estados brasileños. El AUDIT y datos sociodemográficos fueron respondidos por 639 universitarios de los dos sexos, mayores de 18 años, distribuidos en diferentes cursos superiores de instituciones particulares y públicas en cuatro estados en Brasil. Realizando distintos cálculos estadísticos, se observaron indicadores psicométricos que revelaron confiabilidad en la medida del AUDIT en la muestra investigada. Este procedimiento tanto garantizó la medida sobre la identificación del problema del consumo de alcohol como se observó que, independientemente del contexto educativo de los universitarios, en los referidos estados brasileños, todos los respondedores revelaron problemas con el consumo alcohólico
Inferring high-resolution human mixing patterns for disease modeling
Mathematical and computational modeling approaches are increasingly used as
quantitative tools in the analysis and forecasting of infectious disease
epidemics. The growing need for realism in addressing complex public health
questions is however calling for accurate models of the human contact patterns
that govern the disease transmission processes. Here we present a data-driven
approach to generate effective descriptions of population-level contact
patterns by using highly detailed macro (census) and micro (survey) data on key
socio-demographic features. We produce age-stratified contact matrices for 277
sub-national administrative regions of countries covering approximately 3.5
billion people and reflecting the high degree of cultural and societal
diversity of the focus countries. We use the derived contact matrices to model
the spread of airborne infectious diseases and show that sub-national
heterogeneities in human mixing patterns have a marked impact on epidemic
indicators such as the reproduction number and overall attack rate of epidemics
of the same etiology. The contact patterns derived here are made publicly
available as a modeling tool to study the impact of socio-economic differences
and demographic heterogeneities across populations on the epidemiology of
infectious diseases.Comment: 18 pages, 7 figure
Sex-Biased Expression of MicroRNAs in Schistosoma mansoni
Schistosomiasis is an important neglected tropical disease caused by digenean helminth parasites of the genus Schistosoma. Schistosomes are unusual in that they are dioecious and the adult worms live in the blood system. MicroRNAs play crucial roles during gene regulation and are likely to be important in sex differentiation in dioecious species. Here we characterize 112 microRNAs from adult Schistosoma mansoni individuals, including 84 novel microRNA families, and investigate the expression pattern in different sexes. By deep sequencing, we measured the relative expression levels of conserved and newly identified microRNAs between male and female samples. We observed that 13 microRNAs exhibited sex-biased expression, 10 of which are more abundant in females than in males. Sex chromosomes showed a paucity of female-biased genes, as predicted by theoretical evolutionary models. We propose that the recent emergence of separate sexes in Schistosoma had an effect on the chromosomal distribution and evolution of microRNAs, and that microRNAs are likely to participate in the sex differentiation/maintenance process
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