899 research outputs found

    Financing Africa: Through the crisis and beyond.

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    [Dataset available: http://hdl.handle.net/10411/17679]

    Automated segmentation of tissue images for computerized IHC analysis

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    This paper presents two automated methods for the segmentation ofimmunohistochemical tissue images that overcome the limitations of themanual approach aswell as of the existing computerized techniques. The first independent method, based on unsupervised color clustering, recognizes automatically the target cancerous areas in the specimen and disregards the stroma; the second method, based on colors separation and morphological processing, exploits automated segmentation of the nuclear membranes of the cancerous cells. Extensive experimental results on real tissue images demonstrate the accuracy of our techniques compared to manual segmentations; additional experiments show that our techniques are more effective in immunohistochemical images than popular approaches based on supervised learning or active contours. The proposed procedure can be exploited for any applications that require tissues and cells exploration and to perform reliable and standardized measures of the activity of specific proteins involved in multi-factorial genetic pathologie

    Progress towards an accurate determination of the Boltzmann constant by Doppler spectroscopy

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    In this paper, we present significant progress performed on an experiment dedicated to the determination of the Boltzmann constant, k, by accurately measuring the Doppler absorption profile of a line in a gas of ammonia at thermal equilibrium. This optical method based on the first principles of statistical mechanics is an alternative to the acoustical method which has led to the unique determination of k published by the CODATA with a relative accuracy of 1.7 ppm. We report on the first measurement of the Boltzmann constant by laser spectroscopy with a statistical uncertainty below 10 ppm, more specifically 6.4 ppm. This progress results from improvements in the detection method and in the statistical treatment of the data. In addition, we have recorded the hyperfine structure of the probed saQ(6,3) rovibrational line of ammonia by saturation spectroscopy and thus determine very precisely the induced 4.36 (2) ppm broadening of the absorption linewidth. We also show that, in our well chosen experimental conditions, saturation effects have a negligible impact on the linewidth. Finally, we draw the route to future developments for an absolute determination of with an accuracy of a few ppm.Comment: 22 pages, 11 figure

    Human Bocaviruses Are Highly Diverse, Dispersed, Recombination Prone, and Prevalent in Enteric Infections

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    International audienceA new species of parvovirus, tentatively named human bocavirus 4 (HBoV4), was genetically characterized. Among 641 feces samples obtained from children and adults, the most commonly detected bocavirus species were, in descending order, HBoV2, HBoV3, HBoV4, and HBoV1, with an HBoV2 prevalence of 21% and 26% in Nigerian and Tunisian children, respectively. HBoV3 or HBoV4 species were found in 12 of 192 patients with non-polio acute flaccid paralysis in Tunisia and Nigeria and 0 of 96 healthy Tunisian contacts (P = .01). Evidence of extensive recombination at the NP1 and VP1 gene boundary between and within bocavirus species was found. The high degree of genetic diversity seen among the human bocaviruses found in feces specimens, relative to the highly homogeneous HBoV1, suggest that this worldwide-distributed respiratory pathogen may have recently evolved from an enteric bocavirus after acquiring an expanded tropism favoring the respiratory tract. Elucidating the possible role of the newly identified enteric bocaviruses in human diseases, including acute flaccid paralysis and diarrhea, will require further epidemiological studies

    Locker box location planning under uncertainty in demand and capacity availability

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    In this paper, we address the location of locker boxes in the last-mile delivery context under uncertainty in demand and capacity. The problem is modeled as an extension of the capacitated facility location problem, in which a fixed number of facilities has to be opened, choosing among a set of potential locations. Facilities are characterized by a homogeneous capacity, but a capacity reduction may occur with a given probability. The uncertainty in demand and capacity is incorporated through a set of discrete scenarios. Each customer can be assigned only to compatible facilities, i.e., to facilities located within a given radius from the individual location. The goal is to first maximize the total number of customers assigned to locker boxes, while, in case of a tie on this primary objective, a secondary objective intervenes aiming at minimizing the average distance covered by customers to reach their assigned locker box. A stochastic mathematical model as well as three matheuristics are presented. We provide an extensive computational study in order to analyze the impact of different parameters on the complexity of the problem. The importance of considering uncertainty in input data is discussed through the usage of general stochastic indicators from the literature as well as of problem specific indicators. A real-world case related to the City of Turin in Italy is analyzed in detail. The benefit achievable by optimizing locker box locations is discussed and a comparison with the current configuration is provide

    Financing Africa:Through the crisis and beyond

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    The environment in which African financial systems operate has changed dramatically over the past years. The global financial system has undergone a major transformation after the recent financial crisis, with the center of economic and financial power shifting from developed to several emerging countries, including China, India, and Brazil. Additionally, the crisis has led to regulatory reform discussions among developed and emerging countries, with repercussions on financial sector regulation in Africa. Finally, technology has changed the economics of retail banking, revealing its potential to increase access to financial services dramatically, but also posing new regulatory challenges. Financing Africa: Through the Crisis and Beyond takes a fresh look at Africa’s financial systems in light of these recent changes. Benefiting from better data and a wide array of experiences across the continent, the book looks at the challenges of expanding the outreach of financial systems, lengthening financial contracts, and safeguarding financial systems. The authors identify three priority areas for policy action: the positive role of innovation and competition; a stronger focus on nontraditional financial service providers; and more emphasis on addressing demand-side constraints. Recognizing that all financial sector policy is local, the authors carefully distinguish between different country groupings, differentiating between low- and middle-income and small and larger economies among others, with a special focus on resource-based economies and post-conflict countries. And unlike other publications on this topic, this book includes analysis of the North African countries.  A joint collaboration between the African Development Bank, BMZ (Federal Ministry for Economic Cooperation and Development), and the World Bank, this book is a valuable asset to practitioners, development partners, and policy makers concerned about a more inclusive and effective financial system

    Mise à jour des recommandations du GEFPICS pour l’évaluation du statut HER2 dans les cancers du sein en France

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    En Europe, les patientes atteintes d’un cancer du sein invasif susceptibles de recevoir un traitement ciblé anti-HER2 sont actuellement sélectionnées sur la base d’un test immunohistochimique (IHC). Les techniques d’hybridation in situ (HIS) doivent être utilisées pour l’évaluation des cas IHC ambigus (2+) et pour l’étalonnage de la technique IHC. Les patientes éligibles au traitement ciblant HER2 présentent un statut HER2 positif défini par un test IHC 3+ ou un test 2+ amplifié. Une détection correcte du statut HER2 est indispensable à une utilisation optimale des thérapeutiques ciblées puisque leur efficacité est limitée aux patientes surexprimant HER2. Il est capital que l’évaluation du statut HER2 soit optimisée et fiable. Ces recommandations du groupe d’étude des facteurs pronostiques IHC dans le cancer du sein (GEFPICS) détaillent et commentent les différentes étapes des techniques IHC et HIS, les contrôles utilisables et les règles générales de l’apprentissage de la lecture. Une fois acquis, ce savoir-faire doit être pérennisé par l’observation de règles de bonnes pratiques techniques (utilisation rigoureuse de témoins internes et externes et participation régulière à des programmes d’Assurance qualité [AQ])., Summary In Europe, patients who may benefit from an HER2 targeted drug are currently selected by immunohistochemistry (IHC). In situ hybridization (ISH) techniques should be used for complementary assessment of ambiguous 2+ IHC cases and for the calibration of the IHC technique. Eligibility to an HER2 target treatment is defined by an HER2 positive status being IHC test 3+ or 2+ amplified. Reliable detection of HER2 status is essential to the appropriate usage of HER2 targeted drugs because its specificity is limited to tumors overexpressing HER2. It is essential that the IHC evaluation of the HER2 status of a mammary carcinoma is optimized and reliable. This GEFPICS’ guidelines look over the different steps of the IHC technique, the controls and, the rules for interpretation. Once acquired, this knowledge must be perpetuated by the observation of rules of good technical practice (internal and external controls, quality assurance programs)

    Sterol composition of caper (Capparis spinosa) seeds

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    Caper is a perennial shrub of the Mediterranean Basin. The most important economical species is Capparis spinosa. Sterols of C. spinosa seed oil isolated from seven Tunisian stands were identified andquantified. C. spinosa contained  high levels of phytosterols (2240.4 mg/kg of total extracted lipids), of which -sitosterol, with 1390 mg/kg, was the most abundant (57.53%). Campesterol and stigmasterol accounted for 382 and 265 mg/kg, respectively (17.05 and 11.85% of the total sterols, respectively). C. spinosa seed oil also contained a high level of 5-avenasterol (6%). We detect also brassicasterol (3.39 mg/kg). Cholesterol and campestanol are detected in much lower levels. These results bring attention to the richness of C.spinosa seed oil with sterols which are the most important class of the minor components
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