1,328 research outputs found
Towards Dead Time Inclusion in Neuronal Modeling
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
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
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
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
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
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
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
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
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
- …