860 research outputs found

    Clastic vs. primary precipitated evaporites in the Messinian sicilian Basins

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    The Messinian stratigraphy of Sicily has a particular importance for the comprehension ofthe Messinian salinity crisis as its successions bear the greatest similarity with those of thedeep Mediterranean basins. Despite the large number of studies carried out in the last 30years, we believe that the true time and genetic relationships between the different evaporiticand non evaporitic rock bodies are still not well established. This is probably due to thelimited, partial view offered by the central Sicilian basin, despite its complete Messinianstratigraphic record.Clastic and chaotic evaporitic deposits emplaced by tectonically-driven small to largescaleresedimentation processes form an important part of the MSC record of Sicily in theBelice and Caltanissetta basins. Facies characteristics of clastic evaporites, the stratigraphicrelationships with the other Messinian deposits, their possible significance in the regionalgeological evolution and the implications at a Mediterranean scale will be discussed in thefield. Attention also will be paid to primary precipitated facies of Lower and UpperEvaporites.The main aim of this field trip is to visit and discuss, beside some of the classic localitiesof the Caltanissetta basin, other less known outcrops of western Sicily (Belice basin), inorder to have a more complete regional geological framework of the MSC events in Sicily.This will give the participants the opportunity to discuss many of the still open problemsconcerning the MSC. In this section we suggest some topics for discussion during the fieldtrip

    Expression of calpain-calpastatin system (CCS) member proteins in human lymphocytes of young and elderly individuals; pilot baseline data for the CALPACENT project.

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    Ubiquitous system of regulatory, calcium-dependent, cytoplasmic proteases – calpains – and their endogenous inhibitor – calpastatin – is implicated in the proteolytic regulation of activation, proliferation, and apoptosis of many cell types. However, it has not been thoroughly studied in resting and activated human lymphocytes yet, especially in relation to the subjects’ ageing process. The CALPACENT project is an international (Polish-Italian) project aiming at verifying the hypothesis of the role of calpains in the function of peripheral blood immune cells of Polish (Pomeranian) and Italian (Sicilian) centenarians, apparently relatively preserved in comparison to the general elderly population. In this preliminary report we aimed at establishing and comparing the baseline levels of expression of μ- and m-calpain and calpastatin in various, phenotypically defined, populations of human peripheral blood lymphocytes for healthy elderly Sicilians and Poles, as compared to these values observed in young cohort

    Many-body calculations of plasmon and phonon satellites in angle-resolved photoelectron spectra using the cumulant expansion approach

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    The interaction of electrons with crystal lattice vibrations (phonons) and collective charge-density fluctuations (plasmons) influences profoundly the spectral properties of solids revealed by photoemission spectroscopy experiments. Photoemission satellites, for instance, are a prototypical example of quantum emergent behavior that may result from the strong coupling of electronic states to plasmons and phonons. The existence of these spectral features has been verified over energy scales spanning several orders of magnitude (from 50 meV to 15-20 eV) and for a broad class of compounds such as simple metals, semiconductors, and highly-doped oxides. During the past few years the cumulant expansion approach, alongside with the GW approximation and the theory of electron-phonon and electron-plasmon coupling in solids, has evolved into a predictive and quantitatively accurate approach for the description of the spectral signatures of electron-boson coupling entirely from first principles, and it has thus become the state-of-the-art theoretical tool for the description of these phenomena. In this chapter we introduce the fundamental concepts needed to interpret plasmon and phonon satellites in photoelectron spectra, and we review recent progress on first-principles calculations of these features using the cumulant expansion method

    Modeling organic carbon accumulation rates and residence times in coastal vegetated ecosystems

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    Coastal vegetated “blue carbon” ecosystems can store large quantities of organic carbon (OC) within their soils; however, the importance of these sinks for climate change mitigation depends on the OC accumulation rate (CAR) and residence time. Here we evaluate how two modeling approaches, a Bayesian age-depth model alone or in combination with a two-pool OC model, aid in our understanding of the time lines of OC within seagrass soils. Fitting these models to data from Posidonia oceanica soil cores, we show that age-depth models provided reasonable CAR estimates but resulted in a 22% higher estimation of OC burial rates when ephemeral rhizosphere OC was not subtracted. This illustrates the need to standardize CAR estimation to match the research target and time frames under consideration. Using a two-pool model in tandem with an age-depth model also yielded reasonable, albeit lower, CAR estimates with lower estimate uncertainty, which increased our ability to detect among-site differences and seascape-level trends. Moreover, the two-pool model provided several other useful soil OC diagnostics, including OC inputs, decay rates, and transit times. At our sites, soil OC decayed quite slowly both within fast cycling (0.028 ± 0.014 yr−1) and slow cycling (0.0007 ± 0.0003 yr−1) soil pools, resulting in OC taking between 146 and 825 yr to transit the soil system. Further, an estimated 85% to 93% of OC inputs enter slow-cycling soil pools, with transit times ranging from 891 to 3,115 yr, substantiating the importance of P. oceanica soils as natural, long-term OC sinks

    Adhesions due to peritoneal carcinomatosis caused by a renal carcinoma leading to mechanical gastric outlet obstruction: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Gastric outlet obstruction is a clinical syndrome caused by a variety of mechanical obstructions. Peptic ulcer disease used to be responsible for most gastric outlet obstruction, but in the last 40 years the prevalence of malignant tumors has risen significantly. Adhesive disease is an infrequent and insidious cause of mechanical gastric outlet obstruction.</p> <p>Case presentation</p> <p>We report the case of a 78-year-old Caucasian man who had a clinical history of a right nephrectomy for malignancy three years earlier and who was admitted for a severe gastric outlet obstruction (score of 1) confirmed both by an upper endoscopy and by a fluoroscopic view after contrast injection. A computed tomography scan and a laparotomy, with omental biopsies, showed a peritoneal carcinomatosis with the development of abdominal adhesions that prompted an abnormal gastric rotation around the perpendicular axis of his antrum with a dislocation in the empty space of his right kidney. Symptoms disappeared after surgical bypass through a gastrojejunostomy.</p> <p>Conclusions</p> <p>Our patient experienced a very rare complication characterized by the development of adhesions due to peritoneal carcinomatosis caused by a renal carcinoma treated with nephrectomy. These adhesions prompted an abnormal dislocation of his antrum, as an internal hernia, in the empty space of his right kidney.</p

    Subjective versus objective risk in genetic counseling for hereditary breast and/or ovarian cancers

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    Background. Despite the fact that genetic counseling in oncology provides information regarding objective risks, it can be found a contrast between the subjective and objective risk. The aims of this study were to evaluate the accuracy of the perceived risk compared to the objective risk estimated by the BRCApro computer model and to evaluate any associations between medical, demographic and psychological variables and the accuracy of risk perception. Methods. 130 subjects were given medical-demographic file, Cancer and Genetic Risk Perception, Hospital Anxiety-Depression Scale. It was also computed an objective evaluation of the risk by the BRCApro model. Results. The subjective risk was significantly higher than objective risk. The risk of tumour was overestimated by 56%, and the genetic risk by 67%. The subjects with less cancer affected relatives significantly overestimated their risk of being mutation carriers and made a more innacurate estimation than high risk subjects. Conclusion. The description of this sample shows: general overestimation of the risk, inaccurate perception compared to BRCApro calculation and a more accurate estimation in those subjects with more cancer affected relatives (high risk subjects). No correlation was found between the levels of perception of risk and anxiety and depression. Based on our findings, it is worth pursuing improved communication strategies about the actual cancer and genetic risk, especially for subjects at "intermediate and slightly increased risk" of developing an hereditary breast and/or ovarian cancer or of being mutation carrier

    Sources of pro-cyclicality in east Asian financial systems

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    Procyclicality is a normal feature of economic systems, but financial sector weaknesses can exacerbate it sufficiently to pose a threat to macroeconomic and financial stability. These include shortcomings in bank risk management and governance, in supervision and in terms of dependence on volatile sources of funds. The paper tests econometrically for the importance of such features leading to pro-cyclicality in the financial systems of 11 East Asian countries. This analysis makes it possible to identify specific policy measures for East Asian countries that could limit the extent to which financial systems exacerbate pro-cyclicality

    Multiscale photosynthetic exciton transfer

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    Photosynthetic light harvesting provides a natural blueprint for bioengineered and biomimetic solar energy and light detection technologies. Recent evidence suggests some individual light harvesting protein complexes (LHCs) and LHC subunits efficiently transfer excitons towards chemical reaction centers (RCs) via an interplay between excitonic quantum coherence, resonant protein vibrations, and thermal decoherence. The role of coherence in vivo is unclear however, where excitons are transferred through multi-LHC/RC aggregates over distances typically large compared with intra-LHC scales. Here we assess the possibility of long-range coherent transfer in a simple chromophore network with disordered site and transfer coupling energies. Through renormalization we find that, surprisingly, decoherence is diminished at larger scales, and long-range coherence is facilitated by chromophoric clustering. Conversely, static disorder in the site energies grows with length scale, forcing localization. Our results suggest sustained coherent exciton transfer may be possible over distances large compared with nearest-neighbour (n-n) chromophore separations, at physiological temperatures, in a clustered network with small static disorder. This may support findings suggesting long-range coherence in algal chloroplasts, and provides a framework for engineering large chromophore or quantum dot high-temperature exciton transfer networks.Comment: 9 pages, 6 figures. A significantly updated version is now published online by Nature Physics (2012

    Proteinase-activated receptor 4 stimulation-induced epithelial-mesenchymal transition in alveolar epithelial cells

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    BACKGROUND: Proteinase-activated receptors (PARs; PAR(1–4)) that can be activated by serine proteinases such as thrombin and neutrophil catepsin G are known to contribute to the pathogenesis of various pulmonary diseases including fibrosis. Among these PARs, especially PAR(4), a newly identified subtype, is highly expressed in the lung. Here, we examined whether PAR(4 )stimulation plays a role in the formation of fibrotic response in the lung, through alveolar epithelial-mesenchymal transition (EMT) which contributes to the increase in myofibroblast population. METHODS: EMT was assessed by measuring the changes in each specific cell markers, E-cadherin for epithelial cell, α-smooth muscle actin (α-SMA) for myofibroblast, using primary cultured mouse alveolar epithelial cells and human lung carcinoma-derived alveolar epithelial cell line (A549 cells). RESULTS: Stimulation of PAR with thrombin (1 U/ml) or a synthetic PAR(4 )agonist peptide (AYPGKF-NH(2), 100 μM) for 72 h induced morphological changes from cobblestone-like structure to elongated shape in primary cultured alveolar epithelial cells and A549 cells. In immunocytochemical analyses of these cells, such PAR(4 )stimulation decreased E-cadherin-like immunoreactivity and increased α-SMA-like immunoreactivity, as observed with a typical EMT-inducer, tumor growth factor-β (TGF-β). Western blot analyses of PAR(4)-stimulated A549 cells also showed similar changes in expression of these EMT-related marker proteins. Such PAR(4)-mediated changes were attenuated by inhibitors of epidermal growth factor receptor (EGFR) kinase and Src. PAR(4)-mediated morphological changes in primary cultured alveolar epithelial cells were reduced in the presence of these inhibitors. PAR(4 )stimulation increased tyrosine phosphorylated EGFR or tyrosine phosphorylated Src level in A549 cells, and the former response being inhibited by Src inhibitor. CONCLUSION: PAR(4 )stimulation of alveolar epithelial cells induced epithelial-mesenchymal transition (EMT) as monitored by cell shapes, and epithelial or myofibroblast marker at least partly through EGFR transactivation via receptor-linked Src activation
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