158 research outputs found

    Relative efficiency in the branch network of a Greek bank : a quantitative analysis

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    Measuring and evaluating the efficient use of resources of Bank branches plays a decisive role in a Bank’s strategic planning. Usually, efficiency is measured by using accounting ratios, such as labor productivity, capital productivity, return on assets etc. When these ratios are properly used, they provide significant information regarding the effective operation of the branch, and contribute in carrying out intrabank comparisons and comparisons over a period of time. However, by using such ratios, an important part of the branch operation remains uncovered: the measurement of the effective use of the resources. New mathematical programming models that are related with the degree at which each branch makes use of its resources, are applied to deal with the weaknesses of such ratios. This study discuss the limitations of using accounting ratio analysis for assessing performance and, presents and interprets the results from the application of mathematical programming models in a sample of branches of a Greek Bank.peer-reviewe

    Using digital watermarking to enhance security in wireless medical image transmission

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    This is the published version of the article. Copyright 2010 Mary Ann Liebert Inc.During the last few years, wireless networks have been increasingly used both inside hospitals and in patients’ homes to transmit medical information. In general, wireless networks suffer from decreased security. However, digital watermarking can be used to secure medical information. In this study, we focused on combining wireless transmission and digital watermarking technologies to better secure the transmission of medical images within and outside the hospital. Methods: We utilized an integrated system comprising the wireless network and the digital watermarking module to conduct a series of tests. Results: The test results were evaluated by medical consultants. They concluded that the images suffered no visible quality degradation and maintained their diagnostic integrity. Discussion: The proposed integrated system presented reasonable stability, and its performance was comparable to that of a fixed network. This system can enhance security during the transmission of medical images through a wireless channel.The General Secretariat for Research and Technology of the Hellenic Ministry of Development and the British Council

    Impact Evaluation of Wet-Weather Events on Influent Flow and Loadings of a Water Resource Recovery Facility

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    Since the introduction of environmental legislation and directives in Europe, the impact of combined sewer overflows (CSO) on receiving water bodies has become a priority concern in water and wastewater treatment industry. Time-consuming and expensive local sampling and monitoring campaigns have been carried out to estimate the characteristic flow and pollutant concentrations of CSO water. This study focused on estimating the frequency and duration of wet-weather events and their impacts on influent flow and wastewater characteristics of the largest Italian water resource recovery facility (WRRF) in Castiglione Torinese. Eight years (viz. 2009–2016) of routinely collected influent data in addition to the arithmetic mean daily precipitation rates (PI) of the plant catchment area, were elaborated. Relationships between PI and volumetric influent flow rate (Qin), chemical oxygen demand (COD), ammonium concentration (N-NH4) and total suspended solids (TSS) are investigated. Time series data mining (TSDM) method is implemented for segmentation of time series by use of sliding window algorithm to partition the available records associated with wet and dry weather events based on the daily variation of PI time series. Appling the methodology in conjunction with results obtained from data reduction techniques, a wet-weather definition is proposed for the plant. The results confirm that applied methodology on routinely collected plant data can be considered as a good substitute for time-consuming and expensive sampling campaigns and plant monitoring programs usually conducted for accurate emergency response and long-term preparedness for extreme climate conditions

    The interplay of wind and uplift facilitates over-water flight in facultative soaring birds.

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    Flying over the open sea is energetically costly for terrestrial birds. Despite this, over-water journeys of many birds, sometimes hundreds of kilometres long, are uncovered by bio-logging technology. To understand how these birds afford their flights over the open sea, we investigated the role of atmospheric conditions, specifically wind and uplift, in subsidizing over-water flight at a global scale. We first established that ΔT, the temperature difference between sea surface and air, is a meaningful proxy for uplift over water. Using this proxy, we showed that the spatio-temporal patterns of sea-crossing in terrestrial migratory birds are associated with favourable uplift conditions. We then analysed route selection over the open sea for five facultative soaring species, representative of all major migratory flyways. The birds maximized wind support when selecting their sea-crossing routes and selected greater uplift when suitable wind support was available. They also preferred routes with low long-term uncertainty in wind conditions. Our findings suggest that, in addition to wind, uplift may play a key role in the energy seascape for bird migration that in turn determines strategies and associated costs for birds crossing ecological barriers such as the open sea

    Next-generation HLA typing of 382 International Histocompatibility Working Group reference B-lymphoblastoid cell lines: Report from the 17th International HLA and Immunogenetics Workshop

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    Extended molecular characterization of HLA genes in the IHWG reference B-lymphoblastoid cell lines (B-LCLs) was one of the major goals for the 17th International HLA and Immunogenetics Workshop (IHIW). Although reference B-LCLs have been examined extensively in previous workshops complete high-resolution typing was not completed for all the classical class I and class II HLA genes. To address this, we conducted a single-blind study where select panels of B-LCL genomic DNA samples were distributed to multiple laboratories for HLA genotyping by next-generation sequencing methods. Identical cell panels comprised of 24 and 346 samples were distributed and typed by at least four laboratories in order to derive accurate consensus HLA genotypes. Overall concordance rates calculated at both 2- and 4-field allele-level resolutions ranged from 90.4% to 100%. Concordance for the class I genes ranged from 91.7 to 100%, whereas concordance for class II genes was variable; the lowest observed at HLA-DRB3 (84.2%). At the maximum allele-resolution 78 B-LCLs were defined as homozygous for all 11 loci. We identified 11 novel exon polymorphisms in the entire cell panel. A comparison of the B-LCLs NGS HLA genotypes with the HLA genotypes catalogued in the IPD-IMGT/HLA Database Cell Repository, revealed an overall allele match at 68.4%. Typing discrepancies between the two datasets were mostly due to the lower-resolution historical typing methods resulting in incomplete HLA genotypes for some samples listed in the IPD-IMGT/HLA Database Cell Repository. Our approach of multiple-laboratory NGS HLA typing of the B-LCLs has provided accurate genotyping data. The data generated by the tremendous collaborative efforts of the 17th IHIW participants is useful for updating the current cell and sequence databases and will be a valuable resource for future studies

    Identification of the Biotransformation Products of 2-Ethylhexyl 4-(N,N-Dimethylamino)benzoate

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    Nowadays, 2-ethylhexyl 4-(N,N-dimethylamino)benzoate (EDP) is one of the most widely used UV filters in sunscreen cosmetics and other cosmetic products. However, undesirable processes such as percutaneous absorption and biological activity have been attributed to this compound. The in vitro metabolism of EDP was elucidated in the present work. First of all, the phase I biotransformation was studied in rat liver microsomes and two metabolites, N,N-dimethyl-p-aminobenzoic acid (DMP) and N-monomethyl-p-aminobenzoic acid (MMP), were identified by GC-MS analysis. Secondly, the phase II metabolism was investigated by means of LC-MS. The investigated reactions were acetylation and glucuronidation working with rat liver cytosol and with both human and rat liver microsomes, respectively. Analogue studies with p-aminobenzoic acid (PABA) were carried out in order to compare the well established metabolic pathway of PABA with the unknown biotransformation of EDP. In addition, a method for the determination of EDP and its two phase I metabolites in human urine was developed. The methodology requires a solid-phase extraction prior to LC-MS analysis. The method is based on standard addition quantification and has been fully validated. The repeatability of the method, expressed as relative standard deviation, was in the range 3.4–7.4% and the limit of detection for all quantified analytes was in the low ng mL−1 range

    Data envelopment analysis in financial services: a citations network analysis of banks, insurance companies and money market funds

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    Development and application of the data envelopment analysis (DEA) method, have been the subject of numerous reviews. In this paper, we consider the papers that apply DEA methods specifically to financial services, or which use financial services data to experiment with a newly introduced DEA model. We examine 620 papers published in journals indexed in the Web of Science database, from 1985 to April 2016. We analyse the sample applying citations network analysis. This paper investigates the DEA method and its applications in financial services. We analyse the diffusion of DEA in three sub-samples: (1) banking groups, (2) money market funds, and (3) insurance groups by identifying the main paths, that is, the main flows of the ideas underlying each area of research. This allows us to highlight the main approaches, models and efficiency types used in each research areas. No unique methodological preference emerges within these areas. Innovations in the DEA methodologies (network models, slacks based models, directional distance models and Nash bargaining game) clearly dominate recent research. For each subsample, we describe the geographical distribution of these studies, and provide some basic statistics related to the most active journals and scholars

    The evolution of reproductive isolation in a simultaneous hermaphrodite, the freshwater snail Physa

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    <p>Abstract</p> <p>Background</p> <p>The cosmopolitan freshwater snail <it>Physa acuta </it>has recently found widespread use as a model organism for the study of mating systems and reproductive allocation. Mitochondrial DNA phylogenies suggest that <it>Physa carolinae</it>, recently described from the American southeast, is a sister species of <it>P. acuta</it>. The divergence of the <it>acuta/carolinae </it>ancestor from the more widespread <it>P. pomilia </it>appears to be somewhat older, and the split between a hypothetical <it>acuta/carolinae/pomilia </it>ancestor and <it>P. gyrina </it>appears older still.</p> <p>Results</p> <p>Here we report the results of no-choice mating experiments yielding no evidence of hybridization between <it>gyrina </it>and any of four other populations (<it>pomilia, carolinae</it>, Philadelphia <it>acuta</it>, or Charleston <it>acuta</it>), nor between <it>pomilia </it>and <it>carolinae</it>. Crosses between <it>pomilia </it>and both <it>acuta </it>populations yielded sterile F1 progeny with reduced viability, while crosses between <it>carolinae </it>and both <it>acuta </it>populations yielded sterile F1 hybrids of normal viability. A set of mate-choice tests also revealed significant sexual isolation between <it>gyrina </it>and all four of our other <it>Physa </it>populations, between <it>pomilia </it>and <it>carolinae</it>, and between <it>pomilia </it>and Charleston <it>acuta</it>, but not between <it>pomilia </it>and the <it>acuta </it>population from Philadelphia, nor between <it>carolinae </it>and either <it>acuta </it>population. These observations are consistent with the origin of hybrid sterility prior to hybrid inviability, and a hypothesis that speciation between <it>pomilia </it>and <it>acuta </it>may have been reinforced by selection for prezygotic reproductive isolation in sympatry.</p> <p>Conclusions</p> <p>We propose a two-factor model for the evolution of postzygotic reproductive incompatibility in this set of five <it>Physa </it>populations consistent with the Dobzhansky-Muller model of speciation, and a second two-factor model for the evolution of sexual incompatibility. Under these models, species trees may be said to correspond with gene trees in American populations of the freshwater snail, <it>Physa</it>.</p
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