13,409 research outputs found

    A novel admission control scheme for network slicing based on squatting and kicking strategies

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    New services and applications impose differentquality of service (QoS) requirements on network slicing. Tomeet differentiated service requirements, current Internet servicemodel has to support emerging real-time applications from 5Gnetworks. The admission control mechanisms are expected tobe one of the key components of the future integrated serviceInternet model, for providing multi-level service guarantees withthe different classes (slices) of services. Therefore, this paperintroduces a new flexible admission control mechanism, basedon squatting and kicking techniques (SKM), which can beemployed under network slicing scenario. From the results, SKMprovides 100% total resource utilization in bandwidth contextand 100% acceptance ratio for highest priority class underdifferent input traffic volumes, which cannot be achieved byother existing schemes such as AllocTC-Sharing model due topriority constraints.Peer ReviewedPostprint (published version

    Conhecimento de software para pesquisas

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    El proyecto visa contribuir con las expectativas de los estudiantes interesados en conocer las herramientas informáticas y de visualización de datos más utilizados en las pesquisas para comunicar resultados coherentes y fundamentados dirigidos a la comunidad académica y otros interesados, así como la utilización de estas herramientas en la creación de TCCs y cualquier trabajo del ámbito académico necesario para el desarrollo de una investigación pertinente. Por este medio se busca ayudar la formación académica de futuros investigadores en el área de las pesquisas cuantitativas y cualitativas con una alta calidad de desarrollo, así mismo busca facilitar la realización de dichas investigaciones cuales podrán ser más didácticas al conocer las diferentes herramientas de creación de estás. Para la realización de este proyecto se llevaron a cabo aulas teórico-prácticas en modalidad de Minicurso de no más de cuatro horas, con la participación de diferentes docentes y servidores de la institución universitaria UNILA con conocimiento íntegro de herramientas informáticas para pesquisas en busca de impartir estos conocimientos de desarrollo de investigaciones al mayor número de estudiantes y/o profesionales de diferentes ramas del ámbito académico. La ejecución de proyecto ya ha dado resultados parciales en los que se puede advertir cierta facilidad por parte de alumnos y servidores participantes para realizar investigaciones en sus diferentes ámbitos en las que se desempeñan

    Risk factors for peritoneal dialysis catheter failure in children

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    Background Peritoneal dialysis catheter (PDC) failure still remains a common clinical problem in pediatric patients despite advancements in catheter placement and dialysis techniques. Our aim was to determine the risk factors that may lead to PDC failure, especially those factors that could be potentially modified to minimize PDC failures.Patients and methods This study was designed as a retrospective chart review of 31 patients less than 12 years of age who had end-stage renal disease (ESRD) on whom a total of 54 operative PDC placements were carried out at the tertiary Children’s Hospital, King Fahad Medical City, Riyadh, Saudi Arabia, from January 2007 to December 2010. The data included patient demographics and perioperative and operative variables.Results Fifty-four PDCs were inserted in 31 pediatric patients with ESRD, of whom 17 (55%) were boys and 14 (45%) were girls. Young age showed a statistically significant effect on PDC failure [1.8 (± 5) vs. 5 (± 7.8), P = 0.007], whereas weight did not (P = 0.085). Five types of PDCs were used, which showed significant association with PDC failure (P =0.009). Supraumbilical paramedian abdominal entry incisions were used in 49 (90.7%) patients without peritoneal leakage in any case. Nonsimultaneous omentectomy and upward PDC exit site orientation showed significant association with PDC failure (Pr0.001). The causes of PDC failure included idiopathic peritonitis in 13 (56.5%), PDC occlusion by omentum in five (21.7%), PDC malposition in four (17.4%) patients, and PDC leakage in one (4.4%) patient. Peritonitis showed a high statistical significance in PDC failure with P value of less than 0.001. The serum albumin level at the time of PDC insertion was not statistically significant in terms of PDC failure (P = 0.40) but had a high association with idiopathic peritonitis.Conclusion Our study provides some recommendations to minimize PDC failures that include improvement of patients’ nutritional status, use of a swan-neck double-cuffed catheter, paramedian abdominal entry incision, simultaneous omentectomy, downward orientation of exit site, and use of an up-to-date technique by a dedicated team for proper use of PDC. However, prospective studies possibly on a multicentric basis are necessary to standardize the best PDC insertion and maintenance techniques to minimize PDC failures and improve the quality of life for children with ESRD. Keywords: end-stage renal disease, pediatric patients, peritoneal dialysis, tenckhoff cathete

    Drugs use during pregnancy at Medani Maternity Hospital, Sudan

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    Background: There is a limited knowledge on use of drugs during pregnancy including beneficial and possible adverse effects of drugs on both the mother and the fetus.Objective: To investigate epidemiology of use of drugs during pregnancy.Methods: A cross sectional hospital based study at Medani Hospital during the period December 2011. After signing an informed consent, a pre-tested questionnaire was used to gather data from each parturient mother on her age, parity, level of education, antenatal care visits and use of drug during the index pregnancy.Results: The vast majority (334; 98.2%) of the interviewed women used drugs during the index pregnancy. Around ten percent (35; 10.5%) of these women used the drugs in the first trimester of pregnancy. The majority (266; 78.2%) used the drugs in third trimester and the rest used it in the second trimester. The most common drugs used were antibiotics, tonics, antimalarials and antiemetic.Conclusion: There is a very high rate of drug use in this setting. Antibiotics and antimalarials drugs were the most used drugs.Keywords: drugs, pregnancy, antibiotics, antimalarials, Sudan

    Levy distribution and long correlation times in supermarket sales

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    Sales data in a commodity market (supermarket sales to consumers) has been analysed by studying the fluctuation spectrum and noise correlations. Three related products (ketchup, mayonnaise and curry sauce) have been analysed. Most noise in sales is caused by promotions, but here we focus on the fluctuations in baseline sales. These characterise the dynamics of the market. Four hitherto unnoticed effects have been found that are difficult to explain from simple econometric models. These effects are: (1) the noise level in baseline sales is much higher than can be expected for uncorrelated sales events; (2) weekly baseline sales differences are distributed according to a broad non-Gaussian function with fat tails; (3) these fluctuations follow a Levy distribution of exponent alpha = 1.4, similar to financial exchange markets and in stock markets; and (4) this noise is correlated over a period of 10 to 11 weeks, or shows an apparent power law spectrum. The similarity to stock markets suggests that models developed to describe these markets may be applied to describe the collective behaviour of consumers.Comment: 19 pages, 7 figures, accepted for publication in Physica

    Pharmacological activation of a novel p53-dependent S-phase checkpoint involving CHK-1.

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    We have recently shown that induction of the p53 tumour suppressor protein by the small-molecule RITA (reactivation of p53 and induction of tumour cell apoptosis; 2,5-bis(5-hydroxymethyl-2-thienyl)furan) inhibits hypoxia-inducible factor-1α and vascular endothelial growth factor expression in vivo and induces p53-dependent tumour cell apoptosis in normoxia and hypoxia. Here, we demonstrate that RITA activates the canonical ataxia telangiectasia mutated/ataxia telangiectasia and Rad3-related DNA damage response pathway. Interestingly, phosphorylation of checkpoint kinase (CHK)-1 induced in response to RITA was influenced by p53 status. We found that induction of p53, phosphorylated CHK-1 and γH2AX proteins was significantly increased in S-phase. Furthermore, we found that RITA stalled replication fork elongation, prolonged S-phase progression and induced DNA damage in p53 positive cells. Although CHK-1 knockdown did not significantly affect p53-dependent DNA damage or apoptosis induced by RITA, it did block the ability for DNA integrity to be maintained during the immediate response to RITA. These data reveal the existence of a novel p53-dependent S-phase DNA maintenance checkpoint involving CHK-1

    Approximate Nearest Neighbor Searching with Non-Euclidean and Weighted Distances

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    We present a new approach to approximate nearest-neighbor queries in fixed dimension under a variety of non-Euclidean distances. We are given a set SS of nn points in Rd\mathbb{R}^d, an approximation parameter ε>0\varepsilon > 0, and a distance function that satisfies certain smoothness and growth-rate assumptions. The objective is to preprocess SS into a data structure so that for any query point qq in Rd\mathbb{R}^d, it is possible to efficiently report any point of SS whose distance from qq is within a factor of 1+ε1+\varepsilon of the actual closest point. Prior to this work, the most efficient data structures for approximate nearest-neighbor searching in spaces of constant dimensionality applied only to the Euclidean metric. This paper overcomes this limitation through a method called convexification. For admissible distance functions, the proposed data structures answer queries in logarithmic time using O(nlog(1/ε)/εd/2)O(n \log (1 / \varepsilon) / \varepsilon^{d/2}) space, nearly matching the best known bounds for the Euclidean metric. These results apply to both convex scaling distance functions (including the Mahalanobis distance and weighted Minkowski metrics) and Bregman divergences (including the Kullback-Leibler divergence and the Itakura-Saito distance)
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