128 research outputs found

    A Cross Entropy Algorithm for Classification with δ\delta−Patterns

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    International audienceA classification strategy based on δ\delta-patterns is developed via a combinatorial optimization problem related with the maximal clique generation problem on a graph. The proposed solution uses the cross entropy method and has the advantage to be particularly suitable for large datasets. This study is tailored for the particularities of the genomic data

    Expression of the vasopressin and oxytocin genes in human hypothalami

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    AbstractPoly(A)+ RNA isolated from post-mortem human hypothalami has been used to characterize the polyprotein precursors to vasopressin and oxytocin. Translation in a cell-free system and subsequent immunoprecipitation with antibodies raised against either vasopressin or neurophysin identified a product of Mr 19000 (prepro-vasopressin). A second less intense product of Mr 16500 was tentatively identified as prepro-oxytocin. A cDNA library derived from the human hypothalamic poly(A)+ RNA was screened for vasopressin and oxytocin-encoding cDNA using heterologous probes; clones encoding the two precursors were identified and found to be organized as their rat and bovine counterparts. Northern blot analysis shows that the mRNAs for the two prepro-hormones consist of ~ 840 (AVP) and ~ 700 (OT) nucleotides

    Sleep-wake sensitive mechanisms of adenosine release in the basal forebrain of rodents : an in vitro study

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    Adenosine acting in the basal forebrain is a key mediator of sleep homeostasis. Extracellular adenosine concentrations increase during wakefulness, especially during prolonged wakefulness and lead to increased sleep pressure and subsequent rebound sleep. The release of endogenous adenosine during the sleep-wake cycle has mainly been studied in vivo with microdialysis techniques. The biochemical changes that accompany sleep-wake status may be preserved in vitro. We have therefore used adenosine-sensitive biosensors in slices of the basal forebrain (BFB) to study both depolarization-evoked adenosine release and the steady state adenosine tone in rats, mice and hamsters. Adenosine release was evoked by high K+, AMPA, NMDA and mGlu receptor agonists, but not by other transmitters associated with wakefulness such as orexin, histamine or neurotensin. Evoked and basal adenosine release in the BFB in vitro exhibited three key features: the magnitude of each varied systematically with the diurnal time at which the animal was sacrificed; sleep deprivation prior to sacrifice greatly increased both evoked adenosine release and the basal tone; and the enhancement of evoked adenosine release and basal tone resulting from sleep deprivation was reversed by the inducible nitric oxide synthase (iNOS) inhibitor, 1400 W. These data indicate that characteristics of adenosine release recorded in the BFB in vitro reflect those that have been linked in vivo to the homeostatic control of sleep. Our results provide methodologically independent support for a key role for induction of iNOS as a trigger for enhanced adenosine release following sleep deprivation and suggest that this induction may constitute a biochemical memory of this state

    Locally Administrated Perindopril Improves Healing in an Ovariectomized Rat Tibial Osteotomy Model

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    Angiotensin-converting enzyme inhibitors are widely prescribed to regulate blood pressure. High doses of orally administered perindopril have previously been shown to improve fracture healing in a mouse femur fracture model. In this study, perindopril was administered directly to the fracture area with the goal of stimulating fracture repair. Three months after being ovariectomized (OVX), tibial fractures were produced in Sprague–Dawley rats and subsequently stabilized with intramedullary wires. Perindopril (0.4 mg/kg/day) was injected locally at the fractured site for a treatment period of 7 days. Vehicle reagent was used as a control. Callus quality was evaluated at 2 and 4 weeks post-fracture. Compared with the vehicle group, perindopril treatment significantly increased bone formation, increased biomechanical strength, and improved microstructural parameters of the callus. Newly woven bone was arranged more tightly and regularly at 4 weeks post-fracture. The ultimate load increased by 66.1 and 76.9% (p<0.01), and the bone volume over total volume (BV/TV) increased by 29.9% and 24.3% (p<0.01) at 2 and 4 weeks post-fracture, respectively. These findings suggest that local treatment with perindopril could promote fracture healing in ovariectomized rats

    EXCHANGE RATE VS. INTEREST RATE: HOW MUCH DOES UIP WORK FOR ROMANIA? (STUDY CASE ON THE EUR/RON CURRENCY)

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    This paper is part of a larger research that aims to analyze the deviation between the Real Exchange Rate and the Equilibrium Exchange Rate in Romania (EUR/RON currency) and to come up with conclusions regarding this deviation and with solutions to minimize it, if the case. Because this is the most important discussion after having the empirical results: what do emergent markets like Romania need to do to keep up with the EU trend? Which are the concessions they have to make in order to maintain a sustainable growth? Do these concessions include breaking the present equilibrium for a future BETTER? Starting with the most well-known methods to calculate the Equilibrium Exchange Rate, this article`s purpose is to create an accurate overview on the UIP model in Romania (the interest rate differential), to verify, using the latest data if the economic environment has brought any changes on the results of this model in the latest years. Is the UIP model a trustworthy equation to establish the Equilibrium Exchange Rate? In order to verify if the UIP model was more reliable in returning a value for the Equilibrium Exchange rate in the latest years on the Romanian market, this paper presents an empirical study containing recent compiled data from the last 10 years, analyzing the 2005 – 2014 period. The NEW in this article is that the used data is very fresh, currently, most probably the only study that verifies the UIP model in Romania for this specific period of time. Why is it useful? Why is it important? Because it doesn`t only bring a confirmation of weather the UIP works for Romania or not but comes up with hints and conclusions regarding the current economic situation of Romania. We can see what has been changed in the local market in the last ten years in terms of monetary policy and what has this change brought with it – if the results are those expected or not and also, what would be the direction for the next years – to most suitable direction to be adopted

    A stochastic differential equation model for transcriptional regulatory networks.

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    International audienceBACKGROUND: This work explores the quantitative characteristics of the local transcriptional regulatory network based on the availability of time dependent gene expression data sets.The dynamics of the gene expression level are fitted via a stochastic differential equation model, yielding a set of specific regulators and their contribution. RESULTS: We show that a beta sigmoid function that keeps track of temporal parameters is a novel prototype of a regulatory function, with the effect of improving the performance of the profile prediction. The stochastic differential equation model follows well the dynamic of the gene expression levels. CONCLUSION: When adapted to biological hypotheses and combined with a promoter analysis, the method proposed here leads to improved models of the transcriptional regulatory networks

    La técnica narrativa en los Relatos con clave, de Jorge Luis Borges

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    El texto borgeano en busca de autor

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    Una de las reglas inalterables que rigen la obra clásica es la de suponer y reconocer obligatoriamente la existencia de un autor, padre y propietario legal de ella. Además, toda obra narrativa tiene un narrador (el yo-sujeto de Ia enunciación),que no se confunde -casi- nunca con el autor,sino que desempeña simplemente un papel dictado por este, y es uno de los personajes creados por él: "En principe, celuiqui dit je n'a pas de nom (cas du narrateur proustien); mais en fait je devient tout de suite un nom, son nom

    El texto borgeano en busca de autor

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