37 resultados para semi-classical analysis

em BORIS: Bern Open Repository and Information System - Berna - Suiça


Relevância:

100.00% 100.00%

Publicador:

Resumo:

Domestic violence victims are increasingly identified at emergency departments (ED). Studies report a prevalence of 6-30%; women are more frequently affected and to a more serious extent than men. Studies have shown that without screening domestic violence victims are often not recognised. The primary aim of the study is to collect data descriptive of domestic violence victims and to show whether medical documentation meets the requirements of forensic medicine.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

This tutorial review article is intended to provide a general guidance to a reader interested to learn about the methodologies to obtain accurate electron density mapping in molecules and crystalline solids, from theory or from experiment, and to carry out a sensible interpretation of the results, for chemical, biochemical or materials science applications. The review mainly focuses on X-ray diffraction techniques and refinement of experimental models, in particular multipolar models. Neutron diffraction, which was widely used in the past to fix accurate positions of atoms, is now used for more specific purposes. The review illustrates three principal analyses of the experimental or theoretical electron density, based on quantum chemical, semi-empirical or empirical interpretation schemes, such as the quantum theory of atoms in molecules, the semi-classical evaluation of interaction energies and the Hirshfeld analysis. In particular, it is shown that a simple topological analysis based on a partition of the electron density cannot alone reveal the whole nature of chemical bonding. More information based on the pair density is necessary. A connection between quantum mechanics and observable quantities is given in order to provide the physical grounds to explain the observations and to justify the interpretations.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

Binding of CD47 to signal regulatory protein alpha (SIRPα), an inhibitory receptor, negatively regulates phagocytosis. In acute myeloid leukemia (AML), CD47 is overexpressed on peripheral blasts and leukemia stem cells and inversely correlates with survival. Aim of the study was to investigate the correlation between CD47 protein expression by immunohistochemistry (IHC) in a bone marrow (BM) tissue microarray (TMA) and clinical outcome in AML patients. CD47 staining on BM leukemia blasts was scored semi-quantitatively and correlated with clinical parameters and known prognostic factors in AML. Low (scores 0-2) and high (score 3) CD47 protein expression were observed in 75% and 25% of AML patients. CD47 expression significantly correlated with percentage BM blast infiltration and peripheral blood blasts. Moreover, high CD47 expression was associated with nucleophosmin (NPM1) gene mutations. In contrast, CD47 expression did not significantly correlate with overall or progression free survival or response to therapy. In summary, a BM TMA permits rapid and reproducible semi-quantitative analysis of CD47 protein expression by IHC. While CD47 expression on circulating AML blasts has been shown to be a negative prognostic marker for a very defined population of AML patients with NK AML, CD47 expression on AML BM blasts is not.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

PURPOSE OF REVIEW: Predicting asthma episodes is notoriously difficult but has potentially significant consequences for the individual, as well as for healthcare services. The purpose of this review is to describe recent insights into the prediction of acute asthma episodes in relation to classical clinical, functional or inflammatory variables, as well as present a new concept for evaluating asthma as a dynamically regulated homeokinetic system. RECENT FINDINGS: Risk prediction for asthma episodes or relapse has been attempted using clinical scoring systems, considerations of environmental factors and lung function, as well as inflammatory and immunological markers in induced sputum or exhaled air, and these are summarized here. We have recently proposed that newer mathematical methods derived from statistical physics may be used to understand the complexity of asthma as a homeokinetic, dynamic system consisting of a network comprising multiple components, and also to assess the risk for future asthma episodes based on fluctuation analysis of long time series of lung function. SUMMARY: Apart from the classical analysis of risk factor and functional parameters, this new approach may be used to assess asthma control and treatment effects in the individual as well as in future research trials.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Annually laminated (varved) sediments of proglacial Lake Silvaplana (46 ̊27’N, 9 ̊48’E, 1791 m a.s.l., Engadine, eastern Swiss Alps) provide an excellent archive for quantitative high-resolution (seasonal – annual) reconstruction of high- and lowfrequency climate signals back to AD 1580. The chronology of the core is based on varve counting, Cs-137, Pb-210 and event stratigraphy. In this study we present a reconstruction based on in-situ reflectance spectroscopy. In situ reflectance spectroscopy is known as a cost- and time-effective non destructtive method for semi-quantitative analysis of pigments (e.g., chlorines and carotenoids) and of lithoclastic sediment fractions. Reflectance-dependent absorption (RDA) was measured with a Gretac Macbeth spectrolino at 2 mm resolution. The spectral coverage ranges from 380 nm to 730 nm at 10 nm band resolution. In proglacial Lake Silvaplana, 99% of the sediment is lithoclastic prior to AD 1950. Therefore, we concentrate on absorption features that are characteristic for lithoclastic sediment fractions. In Lake Silvaplana, two significant correlations that are stable in time were found between RDA typical for lithoclastics and meteorological data: (1) the time series R 570 /R 630 (ratio between RDA at 570 nm and 630 nm) of varves in Lake Silvaplana and May to October temperatures at nearby station of Sils correlate highly significantly (calibration period AD 1864 – 1951, r = 0.74, p < 0.01 for 5ptsmoothed series; RMSE is 0.28 ̊C, RE = 0.41 and CE = 0.38), and (2) the minimum reflectance within the 690nm band (min690) data correlate with May to October (calibration period AD 1864 – 1951, r = 0.68, p < 0.01 for 5pt-smoothed series; RMSE = 0.22 ̊C, RE = 0.5, CE = 0.31). Both proxy series (min690nm and R 570 /R 630 values) are internally highly consistent (r = 0.8, p < 0.001). In proglacial Lake Silvaplana the largest amount of sediment is transported by glacial meltwater. The melting season spans approximately from May to October, which gives us a good understanding of the geophysical processes explaining the correlations between lithoclastic proxies and the meteorological data. The reconstructions were extended back to AD 1580 and show a broad corresponddence with fully independent reconstructions from tree rings and documentary data.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Rockfall is a widespread and hazardous process in mountain environments, but data on past events are only rarely available. Growth-ring series from trees impacted by rockfall were successfully used in the past to overcome the lack of archival records. Dendrogeomorphic techniques have been demonstrated to allow very accurate dating and reconstruction of spatial and temporal rockfall activity, but the approach has been cited to be labor intensive and time consuming. In this study, we present a simplified method to quantify rockfall processes on forested slopes requiring less time and efforts. The approach is based on a counting of visible scars on the stem surface of Common beech (Fagus sylvatica L.). Data are presented from a site in the Inn valley (Austria), where rocks are frequently detached from an ~ 200-m-high, south-facing limestone cliff. We compare results obtained from (i) the “classical” analysis of growth disturbances in the tree-ring series of 33 Norway spruces (Picea abies (L.) Karst.) and (ii) data obtained with a scar count on the stem surface of 50 F. sylvatica trees. A total of 277 rockfall events since A.D. 1819 could be reconstructed from tree-ring records of P. abies, whereas 1140 scars were observed on the stem surface of F. sylvatica. Absolute numbers of rockfalls (and hence return intervals) vary significantly between the approaches, and the mean number of rockfalls observed on the stem surface of F. sylvatica exceeds that of P. abies by a factor of 2.7. On the other hand, both methods yield comparable data on the spatial distribution of relative rockfall activity. Differences may be explained by a great portion of masked scars in P. abies and the conservation of signs of impacts on the stem of F. sylvatica. Besides, data indicate that several scars on the bark of F. sylvatica may stem from the same impact and thus lead to an overestimation of rockfall activity.

Relevância:

40.00% 40.00%

Publicador:

Resumo:

The IFNL4 gene is negatively associated with spontaneous and treatment-induced clearance of hepatitis C virus infection. The activity of IFNλ4 has an important causal role in the pathogenesis, but the molecular details are not fully understood. One possible reason for the detrimental effect of IFNλ4 could be a tissue-specific regulation of an unknown subset of genes. To address both tissue and subtype specificity in the interferon response, we treated primary human hepatocytes and airway epithelial cells with IFNα, IFNλ3 or IFNλ4 and assessed interferon mediated gene regulation using transcriptome sequencing. Our data show a surprisingly similar response to all three subtypes of interferon. We also addressed the tissue specificity of the response, and identified a subset of tissue-specific genes. However, the interferon response is robust in both tissues with the majority of the identified genes being regulated in hepatocytes as well as airway epithelial cells. Thus we provide an in-depth analysis of the liver interferon response seen over an array of interferon subtypes and compare it to the response in the lung epithelium.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Modern imaging technologies, such as computed tomography (CT) techniques, represent a great challenge in forensic pathology. The field of forensics has experienced a rapid increase in the use of these new techniques to support investigations on critical cases, as indicated by the implementation of CT scanning by different forensic institutions worldwide. Advances in CT imaging techniques over the past few decades have finally led some authors to propose that virtual autopsy, a radiological method applied to post-mortem analysis, is a reliable alternative to traditional autopsy, at least in certain cases. The authors investigate the occurrence and the causes of errors and mistakes in diagnostic imaging applied to virtual autopsy. A case of suicide by a gunshot wound was submitted to full-body CT scanning before autopsy. We compared the first examination of sectional images with the autopsy findings and found a preliminary misdiagnosis in detecting a peritoneal lesion by gunshot wound that was due to radiologist's error. Then we discuss a new emerging issue related to the risk of diagnostic failure in virtual autopsy due to radiologist's error that is similar to what occurs in clinical radiology practice.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

When it comes to helping to shape sustainable development, research is most useful when it bridges the science–implementation/management gap and when it brings development specialists and researchers into a dialogue (Hurni et al. 2004); can a peer-reviewed journal contribute to this aim? In the classical system for validation and dissemination of scientific knowledge, journals focus on knowledge exchange within the academic community and do not specifically address a ‘life-world audience’. Within a North-South context, another knowledge divide is added: the peer review process excludes a large proportion of scientists from the South from participating in the production of scientific knowledge (Karlsson et al. 2007). Mountain Research and Development (MRD) is a journal whose mission is based on an editorial strategy to build the bridge between research and development and ensure that authors from the global South have access to knowledge production, ultimately with a view to supporting sustainable development in mountains. In doing so, MRD faces a number of challenges that we would like to discuss with the td-net community, after having presented our experience and strategy as editors of this journal. MRD was launched in 1981 by mountain researchers who wanted mountains to be included in the 1992 Rio process. In the late 1990s, MRD realized that the journal needed to go beyond addressing only the scientific community. It therefore launched a new section addressing a broader audience in 2000, with the aim of disseminating insights into, and recommendations for, the implementation of sustainable development in mountains. In 2006, we conducted a survey among MRD’s authors, reviewers, and readers (Wymann et al. 2007): respondents confirmed that MRD had succeeded in bridging the gap between research and development. But we realized that MRD could become an even more efficient tool for sustainability if development knowledge were validated: in 2009, we began submitting ‘development’ papers (‘transformation knowledge’) to external peer review of a kind different from the scientific-only peer review (for ‘systems knowledge’). At the same time, the journal became open access in order to increase the permeability between science and society, and ensure greater access for readers and authors in the South. We are currently rethinking our review process for development papers, with a view to creating more space for communication between science and society, and enhancing the co-production of knowledge (Roux 2008). Hopefully, these efforts will also contribute to the urgent debate on the ‘publication culture’ needed in transdisciplinary research (Kueffer et al. 2007).

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Classical liquid-state high-resolution (HR) NMR spectroscopy has proved a powerful tool in the metabonomic analysis of liquid food samples like fruit juices. In this paper the application of (1)H high-resolution magic angle spinning (HR-MAS) NMR spectroscopy to apple tissue is presented probing its potential for metabonomic studies. The (1)H HR-MAS NMR spectra are discussed in terms of the chemical composition of apple tissue and compared to liquid-state NMR spectra of apple juice. Differences indicate that specific metabolic changes are induced by juice preparation. The feasibility of HR-MAS NMR-based multivariate analysis is demonstrated by a study distinguishing three different apple cultivars by principal component analysis (PCA). Preliminary results are shown from subsequent studies comparing three different cultivation methods by means of PCA and partial least squares discriminant analysis (PLS-DA) of the HR-MAS NMR data. The compounds responsible for discriminating organically grown apples are discussed. Finally, an outlook of our ongoing work is given including a longitudinal study on apples.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Considerable efforts have been directed toward the identification of small-ruminant prion diseases, i.e., classical and atypical scrapie as well as bovine spongiform encephalopathy (BSE). Here we report the in-depth molecular analysis of the proteinase K-resistant prion protein core fragment (PrP(res)) in a highly scrapie-affected goat flock in Greece. The PrP(res) profile by Western immunoblotting in most animals was that of classical scrapie in sheep. However, in a series of clinically healthy goats we identified a unique C- and N-terminally truncated PrP(res) fragment, which is akin but not identical to that observed for atypical scrapie. These findings reveal novel aspects of the nature and diversity of the molecular PrP(res) phenotypes in goats and suggest that these animals display a previously unrecognized prion protein disorder.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The association between PRNP variation and scrapie incidence was investigated in a highly affected Greek goat herd. Four mutations were identified at codons 171Q/R, 211R/Q, 222Q/K and 240P/S. Lysine at codon 222 was found to be associated with the protection from natural scrapie (P=0.0111). Glutamine at codon 211 was observed in eight animals, all of them being scrapie-negative, indicating a possible protective role of this polymorphism although statistical analysis failed to support it (P=0.1074). A positive association (P=0.0457) between scrapie-affected goats and the wild-type Q(171)R(211)Q(222)S(240) allele is presented for the first time. In addition, a novel R(171)RQS allele, which is identical to the A(136)R(154)R(171) allele that has been associated with resistance to classical scrapie in sheep, was observed in low frequency. Resistant alleles that include K(222) and Q(211) are absent or rare in sheep and can provide the basis for the development of a feasible breeding programme for scrapie eradication in goats.