3,638 research outputs found

    Optimal Fair Scheduling in S-TDMA Sensor Networks for Monitoring River Plumes

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    Underwater wireless sensor networks (UWSNs) are a promising technology to provide oceanographers with environmental data in real time. Suitable network topologies to monitor estuaries are formed by strings coming together to a sink node.This network may be understood as an oriented graph. A number of MAC techniques can be used in UWSNs, but Spatial-TDMA is preferred for fixed networks. In this paper, a scheduling procedure to obtain the optimal fair frame is presented, under ideal conditions of synchronization and transmission errors. The main objective is to find the theoretical maximum throughput by overlapping the transmissions of the nodes while keeping a balanced received data rate from each sensor, regardless of its location in the network. The procedure searches for all cliques of the compatibility matrix of the network graph and solves a Multiple-Vector Bin Packing (MVBP) problem. This work addresses the optimization problem and provides analytical and numerical results for both the minimum frame length and the maximum achievable throughput

    The Economics of the Public Option: Evidence from Local Pharmaceutical Markets

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    We study the effects of competition by state-owned firms, leveraging the decentralized entry of public pharmacies to local markets in Chile. Public pharmacies sell the same drugs at a third of private pharmacy prices, because of stronger upstream bargaining and market power in the private sector, but are of lower quality. Public pharmacies induced market segmentation and price increases in the private sector, which benefited the switchers to the public option but harmed the stayers. The countrywide entry of public pharmacies would reduce yearly consumer drug expenditure by 1.6 percent

    Exercise Ameliorates Endocrine Pancreas Damage Induced by Chronic Cola Drinking in Rats

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    Purpose: This study evaluates whether the daily practice of an exercise routine might protect from endocrine pancreas damage in cola drinking rats. Methods: Forty-eight Wistar rats were randomly assigned to 4 groups depending on a) beverage consumption ad libitum, water (W) or cola beverage (C), and b) physical activity, sedentary (S) or treadmill running (R). Accordingly, 4 groups were studied: WS (water sedentary), WR (water runner), CS (cola sedentary) and CR (cola runner). Body weight, nutritional data, plasma levels of glucose, creatinine, total cholesterol and cholesterol fractions, and triglycerides (enzymocolorimetry), and systolic blood pressure (plethysmography) were measured. After 6 months, euthanasia was performed (overdose sodium thiopental). Pancreatic tissue was immediately excised and conventionally processed for morphometrical and immunohistochemical determinations. Results: The effects of running and chronic cola drinking on pancreas morphology showed interaction (p<0.001) rather than simple summation. Cola drinking (CS vs WS) reduced median pancreatic islet area (-30%, 1.8 104 μm2 vs 2.58 104 μm2, p<0.0001) and median β-cell mass (-43%, 3.81 mg vs 6.73 mg, p<0.0001), and increased median α/β ratio (+49%, 0.64 vs 0.43, p< 0.001). In water drinking rats (WR vs WS), running reduced median α-cell mass (-48%, 1.48 mg vs 2.82 mg, p<0.001) and α/β ratio (-56%, 0.19 vs 0.43, p<0.0001). Differently, in cola drinking rats (CR vs CS), running partially restored median islet area (+15%, 2.06 104 μm2 vs 1.79 104 μm2, p<0.05), increased median β-cell mass (+47%, 5.59 mg vs 3.81 mg, p <0.0001) and reduced median α/β ratio (-6%, 0.60 vs 0.64, p<0.05). Conclusion: This study is likely the first reporting experimental evidence of the beneficial effect of exercise on pancreatic morphology in cola-drinking rats. Presently, the increase of nearly 50% in β cells mass by running in cola drinking rats is by far the most relevant finding. Moderate running, advisably indicated in cola consumers and patients at risk of diabetes, finds here experimental support.Fil: Otero-Losada, Matilde Estela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Cardiológicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Cardiológicas; ArgentinaFil: Gonzalez, Julian. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Cardiológicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Cardiológicas; ArgentinaFil: Muller, Maria Angelica. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Cardiológicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Cardiológicas; ArgentinaFil: Ottaviano, Graciela Mabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Cardiológicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Cardiológicas; ArgentinaFil: Cao, Gabriel Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Cardiológicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Cardiológicas; ArgentinaFil: Azzato, Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Cardiológicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Cardiológicas; ArgentinaFil: Ambrosio, Giuseppe. Università di Perugia; ItaliaFil: Milei, Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Cardiológicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Cardiológicas; Argentin

    Assessment of cognitive performance among Mexican children and adolescents afflicted by simple to complex congenital heart diseases. Preliminary study

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    Among patients afflicted by congenital heart diseases (CHD) diverse, and complex neurological alterations are commonly observed. These have neither been completely identified nor understood. With the aim of identifying specific neurocognitive alterations among children and adolescents afflicted by CHD we investigated the possible presence of cognitive disorders related to the presence of cardiovascular disease with the aid of a sample of 20 patients (12 teenagers and 8 school-age children). Taken altogether, 9 of them were afflicted by simple and 11 by complex pathologies (respectively, CHDs/c). The Neuropsychological Test for Memory and Attention (Neuropsi), standardized for Mexico by Ostrosky et al. (2004), was individually applied to all participants. The information of cognitive performance was obtained in relation to the categories attention and memory, and the same areas allowed us to assess global performance. CHDc subjects performed significantly poorer compared to CHDs in i) attention and executive function, ii) memory and iii) attention and memory. Likewise, among CHDc subjects a significantly higher proportion of cases were diagnosed as abnormal in the same variables. Also a significant and negative correlation was determined between CHD severity and neuropsychological scoring. Children and adolescents afflicted by CHD are at high risk of developing cognitive function alterations including aspects of memory, attention and executive functions, alterations which are likely to be worst among those cases carrying CHDc conditions

    Operación multihop eficiente en redes acústicas submarinas de sensores con planificación TDMA

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    Dos de los problemas a los que se enfrentan las comunicaciones inalámbricas submarinas, y que limitan sobremanera la velocidad de transmisión de los datos, son (i) la atenuación en el medio acuático, que es selectiva en frecuencia, y (ii) el alto retardo de propagación. El primer factor, obliga a usar frecuencias bajas (acústicas), con una consiguiente degradación en la velocidad de transmisión de datos, que limita las aplicaciones posibles. El segundo problema, hace que las técnicas empleadas para el acceso y transmisión de los nodos (capa de enlace OSI o MAC), deban ser lo más eficientes posible para no demorar en demasía la entrega de datos. En concreto, en esta comunicación abordamos el problema de una red de nodos con sensores que pretende ser diseñada para minimizar el impacto de los dos problemas anteriormente citados. Para ello, se establece una técnica TDMA en el acceso al medio y se estudia el efecto que tiene una disciplina de servicio para la capa MAC para transmitir paquetes, basada en una cola FIFO con prioridad, bajo una planificación eficiente de transmisiones en la red. Se plantean distintos escenarios de tráfico generado uniforme o no uniforme por los nodos sensores, además de introducir una métrica (índice de Gini) para la uniformidad de paquetes entregados al Gateway por cada nodo, que es un criterio para que la red sea justa (fairness). Como resultados, se aportan medidas de throughput, retardo extremo a extremo de los paquetes, así como tamaño medio y máximo de las colas de cada nodo.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    High sporulation and overexpression of virulence factors in biofilms and reduced susceptibility to vancomycin and linezolid in recurrent Clostridium [Clostridioides] difficile infection isolates

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    Clostridium [Clostridioides] difficile infection (CDI) is one of the leading causes of diarrhea associated with medical care worldwide, and up to 60% of patients with CDI can develop a recurrent infection (R-CDI). A multi-species microbiota biofilm model of C. difficile was designed to evaluate the differences in the production of biofilms, sporulation, susceptibility to drugs, expression of sporulating (sigH, spo0A), quorum sensing (agrD1, and luxS), and adhesion-associated (slpA and cwp84) pathway genes between selected C. difficile isolates from R-CDI and non-recurrent patients (NR-CDI). We obtained 102 C. difficile isolates from 254 patients with confirmed CDI (66 from NR-CDI and 36 from R-CDI). Most of the isolates were biofilm producers, and most of the strains were ribotype 027 (81.374%, 83/102). Most C. difficile isolates were producers of biofilm (100/102), and most were strongly adherent. Sporulation was higher in the R-CDI than in the NR-CDI isolates (p = 0.015). The isolates from R-CDI patients more frequently demonstrated reduced susceptibility to vancomycin than isolates of NR-CDI patients (27.78% [10/36] and 9.09% [6/66], respectively, p = 0.013). The minimum inhibitory concentrations for vancomycin and linezolid against biofilms (BMIC) were up to 100 times and 20 times higher, respectively, than the corresponding planktonic MICs. Expression of sigH, spo0A, cwp84, and agrD1 was higher in R-CDI than in NR-CDI isolates. Most of the C. difficile isolates were producers of biofilms with no correlation with the ribotype. Sporulation was greater in R-CDI than in NR-CDI isolates in the biofilm model of C. difficile. The R-CDI isolates more frequently demonstrated reduced susceptibility to vancomycin and linezolid than the NR-CDI isolates in both planktonic cells and biofilm isolates. A higher expression of sporulating pathway (sigH, spo0A), quorum sensing (agrD1), and adhesion-associated (cwp84) genes was found in R-CDI than in NR-CDI isolates. All of these factors can have effect on the recurrence of the infection.Peer reviewe

    Intracellular trafficking and cellular uptake mechanism of PHBV nanoparticles for targeted delivery in epithelial cell lines

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    Indexación: Web of Science; Scopus; Scielo.Background: Nanotechnology is a science that involves imaging, measurement, modeling and a manipulation of matter at the nanometric scale. One application of this technology is drug delivery systems based on nanoparticles obtained from natural or synthetic sources. An example of these systems is synthetized from poly(3-hydroxybutyrate-co-3-hydroxyvalerate), which is a biodegradable, biocompatible and a low production cost polymer. The aim of this work was to investigate the uptake mechanism of PHBV nanoparticles in two different epithelial cell lines (HeLa and SKOV-3). Results: As a first step, we characterized size, shape and surface charge of nanoparticles using dynamic light scattering and transmission electron microscopy. Intracellular incorporation was evaluated through flow cytometry and fluorescence microscopy using intracellular markers. We concluded that cellular uptake mechanism is carried out in a time, concentration and energy dependent way. Our results showed that nanoparticle uptake displays a cell-specific pattern, since we have observed different colocalization in two different cell lines. In HeLa (Cervical cancer cells) this process may occur via classical endocytosis pathway and some internalization via caveolin-dependent was also observed, whereas in SKOV-3 (Ovarian cancer cells) these patterns were not observed. Rearrangement of actin filaments showed differential nanoparticle internalization patterns for HeLa and SKOV-3. Additionally, final fate of nanoparticles was also determined, showing that in both cell lines, nanoparticles ended up in lysosomes but at different times, where they are finally degraded, thereby releasing their contents. Conclusions: Our results, provide novel insight about PHBV nanoparticles internalization suggesting that for develop a proper drug delivery system is critical understand the uptake mechanism.https://jnanobiotechnology.biomedcentral.com/articles/10.1186/s12951-016-0241-
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