120 research outputs found

    SHACL Satisfiability and Containment

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    The Shapes Constraint Language (SHACL) is a recent W3C recommendation language for validating RDF data. Specifically, SHACL documents are collections of constraints that enforce particular shapes on an RDF graph. Previous work on the topic has provided theoretical and practical results for the validation problem, but did not consider the standard decision problems of satisfiability and containment, which are crucial for verifying the feasibility of the constraints and important for design and optimization purposes. In this paper, we undertake a thorough study of the different features of SHACL by providing a translation to a new first-order language, called, that precisely captures the semantics of SHACL w.r.t. satisfiability and containment. We study the interaction of SHACL features in this logic and provide the detailed map of decidability and complexity results of the aforementioned decision problems for different SHACL sublanguages. Notably, we prove that both problems are undecidable for the full language, but we present decidable combinations of interesting features

    A GIANT ANEURYSM OF PROPER HEPATIC ARTERY IN A CRYOGLOBULINEMIC PATIENT ON HEMODIALYSIS: A CASE REPORT.

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    Introductrion. Hepatic artery aneurysms (HAAs) are unusual vascular lesions often associated with many different pathological conditions. Most of reported cases are described in association with connective tissue diseases, such as polyarteritis nodosa and systemic lupus erythematosus. Case report. We observed a 52-year-old man with hypertension and HCV-related cryoglobulinemia complicated by end stage renal disease on replacement therapy by hemodialysis. He was admitted to our hospital because of the worsening of blood pressure values (170/110 mmHg) associated to new onset abdominal pain. After an initial physical examination, that showed a periumbelical bruit associated to a pulsatile mass in right hypocondrium, an abdominal ultrasound was performed with evidence of aneurysms of both the right branch (diameter max 4,5 cm) and the left branch (diameter max 1.5 cm) of the hepatic artery. An abdominal CT study was also performed and it confirmed the diagnosis of right intrahepatic artery aneurysm with partially thrombosed area in its peripheral distal portion. Discussion. Many different factors can contribute to the aneurysm formation in this patient. Vasculitic involvement due to cryoglobulinemic disease, therapy with steroid drugs, inflammatory state associated to HCV-related hepatitis, chronic kidney disease and replacement therapy by hemodialysis may all be involved in the development of the aneurysmatic hepatic lesion

    BILATERAL RENAL ARTERY STENOSIS IN A HYPERTENSIVE LUPUS PATIENT WITHOUT RENAL DYSFUNCTION: A CASE REPORT

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    Systemic lupus erythematosus (SLE) is associated with a high prevalence of atherosclero-sis and an enhanced cardiovascular mortality. In adult subjects, several studies have shown the coexistence of SLE and renal artery stenosis, most of them with unilateral in-volvement or with renal dysfunction. We observed a 62-year-old man with SLE and a 10-year history of moderate-to-severe hy-pertension who was admitted to our hospital because of uncontrolled blood pressure val-ues (152/95 mmHg), despite drug therapy. No signs of renal impairment were evident. After an initial physical examination, which presented a periumbilical bruit, a renal ultra-sound was performed with evidence of bilateral renal artery stenosis. An angio-MR study also confirmed the diagnosis and showed a double renal artery on the right side. Many different factors can contribute to the bilateral renal artery stenosis in this patient. Chronic inflammatory state associated to SLE, metabolic alterations with dyslipidemia and steroid therapy may all be involved in the development of the renal atherosclerotic le-sions

    Topography modulates near-ground microclimate in the Mediterranean Fagus sylvatica treeline

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    Understanding processes controlling forest dynamics has become particularly important in the context of ongoing climate change, which is altering the ecological fitness and resilience of species worldwide. However, whether forest communities would be threatened by projected macroclimate change or unaffected due to the controlling effect of local site conditions is still a matter for debate. After all, forest canopy buffer climate extremes and promote microclimatic conditions, which matters for functional plant response, and act as refugia for understory species in a changing climate. Yet precisely how microclimatic conditions change in response to climate warming will depend on the extent to which vegetation structure and local topography shape air and soil temperature. In this study, we posited that forest microclimatic buffering is sensitive to local topographic conditions and canopy cover, and using meteorological stations equipped with data-loggers we measured this effect during 1 year across a climate gradient (considering aspect as a surrogate of local topography) in a Mediterranean beech treeline growing in contrasting aspects in southern Italy. During the growing season, the below-canopy near-ground temperatures were, on average, 2.4 and 1.0 °C cooler than open-field temperatures for south and north-west aspects, respectively. Overall, the temperature offset became more negative (that is, lower under-canopy temperatures at the treeline) as the open-field temperature increased, and more positive (that is, higher under-canopy temperatures at the treeline) as the open-field temperature decreased. The buffering effect was particularly evident for the treeline on the south-facing slope, where cooling of near-ground temperature was as high as 8.6 °C for the maximum temperature (in August the offset peaked at 10 °C) and as high as 2.5 °C for the average temperature. In addition, compared to the south-facing slope, the northern site exhibited less decoupling from free-air environment conditions and low variability in microclimate trends that closely track the free-air biophysical environment. Although such a decoupling effect cannot wholly isolate forest climatic conditions from macroclimate regional variability in the south-facing treeline, it has the potential to partly offset the regional macroclimatic warming experienced in the forest understory due to anthropogenic climate change

    Viral expression and molecular profiling in liver tissue versus microdissected hepatocytes in hepatitis B virus - associated hepatocellular carcinoma.

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    Background: The molecular mechanisms whereby hepatitis B virus (HBV) induces hepatocellular carcinoma (HCC) remain elusive. We used genomic and molecular techniques to investigate host-virus interactions by studying multiple areas of the same liver from patients with HCC. Methods: We compared the gene signature of whole liver tissue (WLT) versus laser capture-microdissected (LCM) hepatocytes along with the intrahepatic expression of HBV. Gene expression profiling was performed on up to 17 WLT specimens obtained at various distances from the tumor center from individual livers of 11 patients with HCC and on selected LCM samples. HBV markers in liver and serum were determined by real-time polymerase chain reaction (PCR)and confocal immunofluorescence. Results: Analysis of 5 areas of the liver showed a sharp change in gene expression between the immediate perilesional area and tumor periphery that correlated with a significant decrease in the intrahepatic expression of HB surface antigen (HBsAg). The tumor was characterized by a large preponderance of down-regulated genes, mostly involved in the metabolism of lipids and fatty acids, glucose, amino acids and drugs, with down-regulation of pathways involved in the activation of PXR/RXR and PPARα/RXRα nuclear receptors, comprising PGC-1α and FOXO1, two key regulators critically involved not only in the metabolic functions of the liver but also in the life cycle of HBV, acting as essential transcription factors for viral gene expression. These findings were confirmed by gene expression of microdissected hepatocytes. Moreover, LCM of malignant hepatocytes also revealed up-regulation of unique genes associated with cancer and signaling Pathways, including two novel HCC-associated cancer testis antigen genes, NUF2 and TTK. Conclusions: Integrated gene expression profiling of whole liver tissue with that of microdissected hepatocytes demonstrated that HBV-associated HCC is characterized by a metabolism switch-off and by a significant reduction in HBsAg. LCM proved to be a critical tool to validate gene signatures associated with HCC and to identify genes that may play a role in hepatocarcinogenesis, opening new perspectives for the discovery of novel diagnostic markers and therapeutic targets

    Absence of an independent association between serum uric acid and left ventricular mass in Caucasian hypertensive women and men

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    Background and aim: Experimentally uric acid may induce cardiomyocyte growth and interstitial fibrosis of the heart. However, clinical studies exploring the relationship between serum uric acid (SUA) and left ventricular (LV) mass yielded conflicting results. The aim of our study was to evaluate the relationships between SUA and LV mass in a large group of Caucasian essential hypertensive subjects. Methods and results: We enrolled 534 hypertensive patients free of cardiovascular complications and without severe renal insufficiency. In all subjects routine blood chemistry, including SUA determination, echocardiographic examination and 24 h ambulatory blood pressure (BP) monitoring were obtained. In the overall population we observed no significant correlation of SUA with LV mass indexed for height2.7 (LVMH2.7) (r = 0.074). When the same relationship was analysed separately in men and women, we found a statistically significant correlation in female gender (r = 0.27; p < 0.001), but not in males (r = 0.042; p = NS). When we grouped the study population in sex-specific tertiles of SUA, an increase in LVMH2.7 was observed in the highest tertiles in women (44.5 \ub1 15.6 vs 47.5 16 vs 55.9 \ub1 22.2 g/m2.7; p < 0.001), but not in men. The association between SUA and LVMH2.7 in women lost statistical significance in multiple regression analyses, after adjustment for age, 24 h systolic BP, body mass index, serum creatinine and other potential confounders. Conclusions: Our findings do not support an independent association between SUA and LV mass in Caucasian men and women with arterial hypertension

    Topoclimate effect on treeline elevation depends on the regional framework: A contrast between Southern Alps (New Zealand) and Apennines (Italy) forests

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    Deciphering the spatial patterns of alpine treelines is critical for understanding the ecosystem processes involved in the persistence of tree species and their altitudinal limit. Treelines are thought to be controlled by temperature, and other environmental variables but they have rarely been investigated in regions with different land-use change legacies. Here, we systematically investigated treeline elevation in the Apennines (Italy) and Southern Alps (New Zealand) with contrasting human history but similar biogeographic trajectories, intending to identify distinct drivers that affect their current elevation and highlight their respective peculiarities. Over 3622 km of Apennines, treeline elevation was assessed in 302 mountain peaks and in 294 peaks along 4504 km of Southern Alps. The major difference between the Southern Alps and Apennines treeline limit is associated with their mountain aspects. In the Southern Alps, the scarcely anthropized Nothofagus treeline elevation was higher on the warmer equator-facing slopes than on the pole-facing ones. Contrary to what would be expected based on temperature limitation, the elevation of Fagus sylvatica treelines in the Apennines was higher on colder, pole-facing slopes than on human-shaped equator-facing, warmer mountainsides. Pervasive positive correlations were found between treeline elevation and temperature in the Southern Alps but not in the Apennines. While the position of the Fagus and Nothofagus treelines converge on similar isotherms of annual average temperature, a striking isothermal difference between the temperatures of the hottest month on which the two taxonomic groups grow exists. We conclude that actual treeline elevation reflects the ecological processes driven by a combination of local-scale topoclimatic conditions, and human disturbance legacy. Predicting dynamic processes affecting current and future alpine treeline position requires further insight into the modulating influences that are currently understood at a regional scale

    Effects of intravenous furosemide plus small-volume hypertonic saline solutions on markers of heart failure

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    Aims: We sought to compare the effects of furosemide&nbsp;+&nbsp;hypertonic saline solution (HSS) treatment in patients with acute decompensated heart failure in comparison with furosemide alone and the response in a compensated state after an acute saline load with regard to serum levels of heart failure biomarkers. Methods and results: We enrolled 141 patients with acute decompensated heart failure with reduced ejection fraction admitted to our Internal Medicine ward from March 2017 to November 2019. A total of 73 patients were randomized to treatment with i.v. high-dose furosemide plus HSS, whereas 68 patients were randomized to i.v. high-dose furosemide alone. Patients treated with furosemide plus HSS compared with controls treated with furosemide alone showed a comparable degree of reduction in the serum levels of interleukin (IL)-6, soluble suppression of tumorigenicity 2 (sST2), and N-terminal pro-brain natriuretic peptide (NT-proBNP) in the ‘between-group’ analysis. Nevertheless, patients treated with high-dose furosemide&nbsp;+&nbsp;HSS showed significantly higher absolute delta values of IL-6 (2.3&nbsp;±&nbsp;1.2 vs. 1.7&nbsp;±&nbsp;0.9, P&nbsp;&lt;&nbsp;0.0005, and 2.0&nbsp;±&nbsp;0.8 vs. 1.85&nbsp;±&nbsp;1.1, P&nbsp;=&nbsp;0.034), sST2 (41.2&nbsp;±&nbsp;8.6 vs. 27.9&nbsp;±&nbsp;7.6, P&nbsp;&lt;&nbsp;0.0005, and 37.1&nbsp;±&nbsp;6.6 vs. 28.4&nbsp;±&nbsp;6.7, P&nbsp;&lt;&nbsp;0.0005), high-sensitivity troponin T (0.03&nbsp;±&nbsp;0.02 vs. 0.02&nbsp;±&nbsp;0.01, P&nbsp;=&nbsp;0.001, and 0.03&nbsp;±&nbsp;0.02 vs. 0.02&nbsp;±&nbsp;0.01, P&nbsp;=&nbsp;0.009), NT-proBNP (7237&nbsp;±&nbsp;7931 vs. 3244&nbsp;±&nbsp;4159, P&nbsp;&lt;&nbsp;0.005, and 5381&nbsp;±&nbsp;4829 vs. 4466&nbsp;±&nbsp;4332, P&nbsp;=&nbsp;0.004), and galectin-3 (15.7&nbsp;±&nbsp;3.2&nbsp;ng/mL vs. 11.68&nbsp;±&nbsp;1.9&nbsp;ng/mL, P&nbsp;&lt;&nbsp;0.0005, and 16.7&nbsp;±&nbsp;3.9&nbsp;ng/mL vs. 11.8&nbsp;±&nbsp;2.4&nbsp;ng/mL, P&nbsp;&lt;&nbsp;0.0005) than patients treated with furosemide alone. After acute saline load, patients treated with i.v. furosemide&nbsp;+&nbsp;HSS in comparison with subjects treated with furosemide alone showed a significantly lower increase in the serum concentrations of IL-6 (−0.26&nbsp;±&nbsp;0.42&nbsp;pg/mL vs. −1.43&nbsp;±&nbsp;0.86&nbsp;pg/mL, P&nbsp;&lt;&nbsp;0.0005), high-sensitivity troponin T (0 vs. −0.02&nbsp;±&nbsp;0.02&nbsp;ng/mL, P&nbsp;&lt;&nbsp;0.0005), sST2 (−8.5&nbsp;±&nbsp;5.9 ng/mL vs. −14.6&nbsp;±&nbsp;6.2&nbsp;ng/mL, P&nbsp;&lt;&nbsp;0.0005), galectin-3 (−2.1&nbsp;±&nbsp;1.5&nbsp;ng/mL vs. −7.1&nbsp;±&nbsp;3.6&nbsp;ng/mL, P&nbsp;&lt;&nbsp;0.0005), and NT-proBNP (77&nbsp;±&nbsp;1373 vs. −1706&nbsp;±&nbsp;2259&nbsp;pg/mL, P&nbsp;&lt;&nbsp;0.0005). Conclusions: Our findings concerning a comparable degree of reduction in the serum levels of three cardinal biomarkers indicate that a reduction in serum heart failure markers is not linked to the higher degree of congestion relief with a more rapid achievement of a clinical compensation state. This issue may have possible benefits on clinical practice concerning its therapeutic effects over and beyond the simple amelioration of clinical congestion signs and symptoms. Nevertheless, our findings of higher delta values after treatment with i.v. furosemide plus HSS indicate a possible higher efficacy by means of modulation of the stretching and fibrosis mechanisms

    Magnetic Field Amplification in Galaxy Clusters and its Simulation

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    We review the present theoretical and numerical understanding of magnetic field amplification in cosmic large-scale structure, on length scales of galaxy clusters and beyond. Structure formation drives compression and turbulence, which amplify tiny magnetic seed fields to the microGauss values that are observed in the intracluster medium. This process is intimately connected to the properties of turbulence and the microphysics of the intra-cluster medium. Additional roles are played by merger induced shocks that sweep through the intra-cluster medium and motions induced by sloshing cool cores. The accurate simulation of magnetic field amplification in clusters still poses a serious challenge for simulations of cosmological structure formation. We review the current literature on cosmological simulations that include magnetic fields and outline theoretical as well as numerical challenges.Comment: 60 pages, 19 Figure

    Infinite-Duration Poorman-Bidding Games

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    In two-player games on graphs, the players move a token through a graph to produce an infinite path, which determines the winner or payoff of the game. Such games are central in formal verification since they model the interaction between a non-terminating system and its environment. We study bidding games in which the players bid for the right to move the token. Two bidding rules have been defined. In Richman bidding, in each round, the players simultaneously submit bids, and the higher bidder moves the token and pays the other player. Poorman bidding is similar except that the winner of the bidding pays the “bank” rather than the other player. While poorman reachability games have been studied before, we present, for the first time, results on infinite-duration poorman games. A central quantity in these games is the ratio between the two players’ initial budgets. The questions we study concern a necessary and sufficient ratio with which a player can achieve a goal. For reachability objectives, such threshold ratios are known to exist for both bidding rules. We show that the properties of poorman reachability games extend to complex qualitative objectives such as parity, similarly to the Richman case. Our most interesting results concern quantitative poorman games, namely poorman mean-payoff games, where we construct optimal strategies depending on the initial ratio, by showing a connection with random-turn based games. The connection in itself is interesting, because it does not hold for reachability poorman games. We also solve the complexity problems that arise in poorman bidding games
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