1,328 research outputs found

    Towards Dead Time Inclusion in Neuronal Modeling

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    A mathematical description of the refractoriness period in neuronal diffusion modeling is given and its moments are explicitly obtained in a form that is suitable for quantitative evaluations. Then, for the Wiener, Ornstein-Uhlenbeck and Feller neuronal models, an analysis of the features exhibited by the mean and variance of the first passage time and of refractoriness period is performed.Comment: 12 pages, 1 figur

    Role of magnetic resonance imaging in the detection and characterization of solid pancreatic nodules: an update

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    Pancreatic ductal adenocarcinoma is the most common malignant tumor of the pancreas. The remaining pancreatic tumors are a diverse group of pancreatic neoplasms that comprises cystic pancreatic neoplasms, endocrine tumors and other uncommon pancreatic tumors. Due to the excellent soft tissue contrast resolution, magnetic resonance imaging (MRI) is frequently able to readily separate cystic from noncystic tumors. Cystic tumors are often easy to diagnose with MRI; however, noncystic non-adenocarcinoma tumors may show a wide spectrum of imaging features, which can potentially mimic ductal adenocarcinoma. MRI is a reliable technique for the characterization of pancreatic lesions. The implementation of novel motion-resistant pulse sequences and respiratory gating techniques, as well as the recognized benefits of MR cholangiopancreatography, make MRI a very accurate examination for the evaluation of pancreatic masses. MRI has the distinctive ability of non-invasive assessment of the pancreatic ducts, pancreatic parenchyma, neighbouring soft tissues, and vascular network in one examination. MRI can identify different characteristics of various solid pancreatic lesions, potentially allowing the differentiation of adenocarcinoma from other benign and malignant entities. In this review we describe the MRI protocols and MRI characteristics of various solid pancreatic lesions. Recognition of these characteristics may establish the right diagnosis or at least narrow the differential diagnosis, thus avoiding unnecessary tests or procedures and permitting better management

    Public Policy and Workers’ Rights: Wrongful Discharge Discipline Actions and Reasonable Good Faith Beliefs

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    In this paper, Professor Ann McGinley responds to Chapter 5 of the ALI\u27s Restatement of the Law: Employment Law ( Restatement of Employment Law ), concerning The Tort of Wrongful Discharge in Violation of Public Policy. \u27 It proceeds in five parts. Following an introduction in Part I, Part II summarizes generally the provisions of Chapter 5, the Working Group\u27s objections to the earlier version and recommendations for changes, and explains (when appropriate) where the final version deviated from the prior version. Part III argues that this chapter should have kept the prior version\u27s protection against wrongful discipline instead of protecting only against wrongful discharge. Part IV argues that requiring employees to have a reasonable belief (in addition to a good faith belief) that conduct will violate the law or harm the public\u27s health or safety is an inappropriately high standard and should be abandoned in favor of requiring only a good faith belief. Part V briefly concludes

    CysMap and CysJoin: Database and tools for protein disulphide localization

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    We have developed a computer program able to make user-customised databases derived from the public PIR non-redundant reference protein database. When the database of interest has been created, the user will generate the map of all the possible linear peptides containing one and two cysteines for each protein and combine them to calculate the mass of all the possible clusters of linear peptides linked by a disulphide bridge with a cysteine pair. It is also possible to create selected maps corresponding to peptides formed by the action of specific proteases. In this way, mass spectrometric data obtained from the hydrolysis of proteins of unknown sequence can be related to that contained in the database for quick disulphide assignment and protein identification. To confirm signal attribution, the program will also furnish the expected mass of cluster peptides after performing a cycle of Edman degradation. The utility of the program is discussed and examples of application are given. © 2005 Federation of European Biochemical Societies

    Transparency, Openness and Knowledge Sharing for Rebuilding and Strengthening Government Institutions

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    The developing of the Open Government Model is allowing an organizational revolution for public administrations, providing to citizens and entrepreneurs a better access to information and public services. It also can allow the increasing of transparency in public agencies and citizen participation, indirectly enhancing collaboration and facilitating democratic processes. Transparency and open data can be powerful tools to stimulate and support public services’ improvements, faster innovation and empower citizens’ rights. So actually many governmental organizations are reviewing and rearranging their processes, information and data to improve policies, enhance legitimacy and openness toward outside parties and citizens. An “open” public knowledge may contribute to establish a collaboration and participation culture among the main stakeholders. In this paper authors focus on a new organizational model to deliver transparent services and to improve an effective collaboration between the public administrations. The research methodology adopted is based on a theoreticaldeductive approach. The study describes general principles to come, through the case strategy, to the empirical analysis of an innovative national government portal called “Transparency Compass Portal”. It tries also to identify the distinctive aspects of some administrative services offered by several public organizations

    Investigating ultrastructural morphology in MIRAGE syndrome-derived fibroblasts using transmission electron microscopy

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    Background Heterozygous de novo variants in the gene SAMD9 cause the complex multisystem disorder, MIRAGE syndrome. Patients are characterised by myelodysplasia, infections, growth restriction, adrenal insufficiency, gonadal dysfunction and enteropathies. Pathogenic variants in SAMD9 are gain-of-function and enhance its role as a growth repressor, leading to growth restriction of many tissues. Two studies have reported changes in skin fibroblasts derived from MIRAGE patients, more specifically identifying enlarged endosomes. We have also previously shown subtle changes in endosome size in patients’ fibroblasts compared to controls. However, these variations in endosomes were not as marked as those described in the literature. Methods We have performed an observational study using transmission electron microscopy (TEM) in a larger number of cells derived from three patients’ fibroblasts to assess ultrastructure morphology compared to control images. Results Consistent changes were observed in cell organelles in all patient samples. In particular, increased endosomal activity was detected, characterised by augmented pinocytosis and vesicle budding, increased endosome number, as well as by large lysosomes and endosomes. Endoplasmic reticulum was also prominent. Mitochondria appeared enlarged in selected cells, possibly due to cellular stress. Cell nuclei did not display major differences compared to controls. Conclusions TEM is a powerful tool to investigate morphological features of tissues and cell organelles, although TEM data could be affected by sample preparation methodology, therefore potentially explaining the variability between independent studies, and its analysis can be dependent on the experience of the researcher. The increased endosomal activity we have observed in patients’ fibroblasts could indicate that SAMD9 regulates endocytosis of receptors, acting as an endosome fusion facilitator, or in lysosomal activation. However, the precise mechanism(s) by which SAMD9 regulates cell growth is still not fully understood, and further studies are needed to elucidate its pathogenic pathway and develop therapeutic approaches to support patients

    Sealant Effectiveness for Children Receiving a Combination of Preventive Methods in a Fluoridated Community: Two-Year Results

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    A series of preventive methods in combination have been used to reduce dental caries in children including dental health education, prophylaxes, pit and fissure sealants, topical application of fluoride and restorative care. Prophylaxes, sealant, and fluoride procedures are repeated every six months. Two-year results show reductions of occlusal caries increments of 74.3% for first graders and 77.1% for sixth graders. Sealant loss, as defined in this study, varied from 33% to 90% with the highest loss occurring in the newly erupted permanent molars during the first six months of the project. These high sealant loss rates are thought to be related to the age of the population which was designed to include children at the ages of peak eruption of permanent molar teeth (ages six and twelve). These teeth were often only minimally erupted and maintaining the dry field required for sealant retention was extremely difficult. However, in spite of these high rates of sealant loss, caries reduction on occlusal surfaces was highly significant in comparison to that of children who did not receive sealants.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68154/2/10.1177_00220345770560121801.pd

    Preoperative staging of colorectal cancer using virtual colonoscopy: correlation with surgical results

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    The aim of this study was to evaluate the clinical usefulness of computed tomography colonography (CTC) in the preoperative staging in patients with abdominal pain for occlusive colorectal cancer (CRC) and to compare the results of CTC with the surgical ones

    Water driven adsorption of amino acids on the (101) anatase TiO2 surface: an ab initio study

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    Arg, Lys and Asp amino acids are known to play a critical role in the adhesion of the RKLPDA engineered peptide on the (101) surface of the titania anatase phase. To understand their contribution to peptide adhesion, we have considered the relevant charge states due to protonation (Arg and Lys) or deprotonation (Asp) occurring in neutral water solution, and studied their adsorption on the (101) anatase TiO2 surface by ab initio total energy calculations based on density functional theory. The adsorption configurations on the hydrated surface are compared to those on the dry surface considering also the presence of the hydration shell around amino acid side-chains. This study explains how water molecules mediate the adsorption of charged amino acids showing that protonated amino acids are chemically adsorbed much more strongly than de-protonated Asp. Moreover it is shown that the polar screening of the hydration shell reduces the adsorption energy of the protonated amino acids to a small extent, thus evidencing that both Arg and Lys strongly adhere on the (101) anatase TiO2 surface in neutral water solution and that they play a major role in the adhesion of the RKLPDA peptide
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