36 research outputs found

    Pipe network model for scaling of dynamic interfaces in porous media

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    We present a numerical study on the dynamics of imbibition fronts in porous media using a pipe network model. This model quantitatively reproduces the anomalous scaling behavior found in imbibition experiments [Phys. Rev. E {\bf 52}, 5166 (1995)]. Using simple scaling arguments, we derive a new identity among the scaling exponents in agreement with the experimental results.Comment: 13 pages, 3 figures, REVTeX, to appear in Phys. Rev. Let

    Calcium ion currents mediating oocyte maturation events

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    During maturation, the last phase of oogenesis, the oocyte undergoes several changes which prepare it to be ovulated and fertilized. Immature oocytes are arrested in the first meiotic process prophase, that is morphologically identified by a germinal vesicle. The removal of the first meiotic block marks the initiation of maturation. Although a large number of molecules are involved in complex sequences of events, there is evidence that a calcium increase plays a pivotal role in meiosis re-initiation. It is well established that, during this process, calcium is released from the intracellular stores, whereas less is known on the role of external calcium entering the cell through the plasma membrane ion channels. This review is focused on the functional role of calcium currents during oocyte maturation in all the species, from invertebrates to mammals. The emerging role of specific L-type calcium channels will be discussed

    Modulation of paraoxonases during infectious diseases and its potential impact on atherosclerosis

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    Re-activated adult epicardial progenitor cells are a heterogeneous population molecularly distinct from their embryonic counterparts.

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    Cardiovascular disease remains the major cause of mortality, and cardiac cell therapy has recently emerged as a paradigm for heart repair. The epicardium is a layer of mesothelial cells covering the heart that during development contributes to different cardiovascular lineages, including cardiomyocytes, but which becomes quiescent after birth. We previously revealed that the peptide thymosin beta 4 (Tβ4) can reactivate adult epicardium-derived cells (EPDCs) after myocardial infarction (MI), to proliferate, and differentiate into cardiovascular derivatives. The aim of this study was to provide a lineage characterization of the adult EPDCs relative to the embryonic epicardial lineage and to determine prospective cell fate biases within the activated adult population during cardiovascular repair. Wt1(GFPCre/+) mice were primed with Tβ4 and MI induced by ligation of the left anterior descending coronary artery. Adult WT1(+) GFP(+) EPDCs were fluorescence-activated cell sorted (FACS) at 2, 4, and 7 days after MI. Embryonic WT1(+) GFP(+) EPDCs were isolated from embryonic hearts (E12.5) by FACS, and sorted cells were characterized by real-time quantitative reverse transcriptase-polymerase chain reaction (RT-qPCR) and immunostaining. Adult WT1(+) GFP(+) EPDCs were highly heterogeneous, expressing cardiac progenitor and mesenchymal stem markers. Based on the expression of stem cell antigen-1 (Sca-1), CD44, and CD90, we identified different subpopulations of EPDCs of varying cardiovascular potential, according to marker gene profiles, with a molecular phenotype distinct from the source embryonic epicardial cells at E12.5. Thus, adult WT1(+) GFP(+) cells are a heterogeneous population that when activated can restore an embryonic gene programme, but do not revert entirely to adopt an embryonic phenotype. Potential biases in cardiovascular cell fate suggest that discrete subpopulations of EPDCs might be clinically relevant for regenerative therapy

    From Ambiguous Regular Expressions to Deterministic Parsing Automata

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    This new parser generator for ambiguous regular expressions (RE) formally extends the Berry-Sethi (BS) algorithm into a finite-state device that specifies the syntax tree(s). We extend the local testability property of the marked RE’s from terminal strings to linearized syntax trees. The generator supports disambiguation, i.e., selecting a preferred tree in case of ambiguity. The selection is parametric with respect to the Greedy or POSIX criterion. The parser is proved correct and has linear-time complexity. The generator is available as an interactive SW tool (on GitHub - see http://github.com/breveglieri/ebs/README)

    The judicial efficiency of Brazilian Labor Courts: a jurimetric analysis based on DEA (Data Envelopment analysis)

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    Brazilian political and judicial system has considered the principle of judicial efficiency due to some changes of 1988 Brazilian Federal Constitution and the creation of the National Council of Justice (CNJ) in 2009. This paper presents the measurement of the judicial efficiency of the Brazilian Labor Courts (TRTs) from 2009 to 2014. The results suggest that among the 24 TRTs, eight of them had improvements in their technical efficiency, eleven labor courts have worsened and five showed no change in their efficiency score. It also suggests that the least efficient Brazilian labor courts were increasing in returns to scale
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