195 research outputs found

    Constraints on Stirring and Dissipation of MHD Turbulence in Molecular Clouds

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    We discuss constraints on the rates of stirring and dissipation of MHD turbulence in molecular clouds. Recent MHD simulations suggest that turbulence in clouds decays rapidly, thus providing a significant source of energy input, particularly if driven at small scales by, for example, bipolar outflows. We quantify the heating rates by combining the linewidth-size relations, which describe global cloud properties, with numerically determined dissipation rates. We argue that, if cloud turbulence is driven on small internal scales, the 12^{12}CO flux (enhanced by emission from weakly supersonic shocks) will be much larger than observed; this, in turn, would imply excitation temperatures significantly above observed values. We reach two conclusions: (1) small-scale driving by bipolar outflows cannot possibly account for cloud support and yield long-lived clouds, unless the published MHD dissipation rates are seriously overestimated; (2) driving on large scales (comparable to the cloud size) is much more viable from an energetic standpoint, and if the actual net dissipation rate is only slightly lower than what current MHD simulations estimate, then the observationally inferred lifetimes and apparent virial equilibrium of molecular clouds can be explained.Comment: 5 pages, 1 figure. To appear in ApJ (2001 April 10

    Use of Circumferentially Cracked Bar sample for CTOD fracture toughness determination in the upper shelf regime

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    In this work, the use of circumferentially cracked bar (CCB) sample to determine material fracture toughness in the upper shelf regime for carbon steels has been investigated. Since high fracture toughness materials are known to exhibit extensive crack tip blunting before ductile crack initiation, accurate specimen design is required to provide realistic fracture toughness measurement. Here, a CCB was designed to have similar loss of constraint as for SENT sample. Continuum damage mechanics was used to predict the occurrence of ductile crack initiation and propagation. Finite element analysis was performed to predict specimen response and to compare computed J-integral crack driving force with measured CTOD. Finally, experimental tests were performed on X65 carbon steel and the measured critical CTOD was compared with available fracture data obtained with SENT

    Marked pseudoepitheliomatous hyperplasia secondary to a red-pigmented tattoo. a case report

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    Tattooing is gaining increasing popularity in developed countries in recent years. Adverse cutaneous reactions of many different types against coumponds in tattoo inks are being reported more and more often in medical literature,especially against red-pigmented tattoo. Delayed immune-mediated reactions can manifest in several ways and different histological patterns have been described This article is protected by copyright. All rights reserved

    Thermal Pattern and Thermal Tracking: fingerprints of an environmental illicit

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    Abstract Being able to identify crime/guilty relationship is central to police investigation and new technologies enable authorities to do this faster and more accurately than ever before. In recent years, our research team has introduced the use of a range of aerial platforms and an innovative application of thermography to detect several illegal activities; for example illegal sanitary sewer and storm-drain connections, illicit discharges and other "anomalies" on the surface waters can be easily identified using their thermal infrared signatures. This paper introduces first results of a Thermal Pattern and Thermal Tracking approach, that can be used to identify different phenomena and several pollutants

    IMPAcT-RLS2: Indagine nazionale sulla salute e la sicurezza sul lavoro: il ruolo dei Rappresentanti dei Lavoratori per la Sicurezza

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    L’Indagine IMPAcT-RLS2 si inserisce nel più ampio programma di ricerca INSuLa2, la cui prima edizione, condotta nel 2014 e rivolta a tutti gli attori della prevenzione, ha approfondito aspetti della tutela della salute e sicurezza sul lavoro (SSL) secondo il punto di vista delle varie figure intervistate. La survey indirizzata ai Rappresentanti dei lavoratori per la sicurezza (RLS), focalizzata inizialmente su tre contesti regionali, è stata implementata grazie all’indagine IMPAcT-RLS, realizzata nel 2016, che ha coinvolto un campione di circa 2.100 soggetti, rappresentativo a livello nazionale, per dimensione aziendale e settore di attività economica. L’indagine ha evidenziato l’importanza di disporre di informazioni sempre più approfondite sul ruolo dei RLS e di monitorarne l’andamento nel tempo. Il presente studio ribadisce l’importanza di istituire rilevazioni periodiche e replicabili, finalizzate ad aumentare le conoscenze e la consapevolezza sui sistemi di prevenzione e promuovere interventi sempre più mirati per il miglioramento della tutela della SSL.The IMPAcT-RLS2 survey is part of a larger context of INSuLa2 research program; its first edition was conducted in 2014 and targeted to all prevention professionals, investigating occupational health and safety (OSH) protection issues perceived by the various professionals’ point of view. The survey addressed to Health and Safety Representatives (HS reps.), focused on three regional contexts, was further implemented in 2016 through the IMPAcT-RLS survey, which involved a sample representative at national level, by company size and economic activity sector consisting of about 2,100 subjects. The survey highlighted the importance of having ever more in-depth information on the role of HS reps. and monitoring their evolution over time. This study arises from the need to create periodic and replicable surveys, aimed at increasing knowledge and awareness of prevention systems and promoting increasingly targeted interventions for improving the protection of OS

    A primary cutaneous adenoid-cystic carcinoma in a young woman. Differential diagnosis and clinical implications

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    Primary cutaneous adenoid-cystic carcinoma (PCACC) is a rare slow-growing neoplasm of disputed histogenesis characterized by a cribriform pattern at histology and local aggressive behaviour. Up to date about 60 cases of PCACC have been reported in the literature. This tumour is most common in the scalp, affects middle-aged and older individuals (mean age 59) and has predilection for women. We describe an unexpected case of PCACC in a 32-years-old woman referred to our clinic for a subcutaneous nodule in the scalp showing a slow growth and indolent course. The differential diagnosis and the clinical management of this PCACC patient, successfully treated with a wide local excision, are presented and discussed

    A 48-week update of a multicentre real-life experience of dupilumab in adult patients with moderate-to-severe atopic dermatitis

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    The long-term efficacy and safety of dupilumab has been demonstrated in clinical trials and only in few real-world studies. We conducted an extension analysis from a previous 16-week study on 109 adult patients affected by moderate-to-severe atopic dermatitis treated with dupilumab. Eczema-Area-and-Severity-Index (EASI), itch numerical-rating-score (itch-NRS), Dermatology-Life-Quality-Index (DLQI) scores, drug survival rate and occurrence of adverse events after 24 and 48 weeks of dupilumab treatment were retrospectively collected. Dupilumab demonstrated sustained improvement of disease severity, pruritus, and quality of life in our series with an increasing percentage of patients gaining EASI75 and EASI90 response during the study period. Few patients interrupted treatment resulting in a very high drug survival rate. We also confirmed the favorable safety profile of the drug with absence of serious adverse events and serious infections throughout the 48-week period. The prevalence of conjunctivitis was low and mainly occurred in the mid-term with resolution of the majority of cases at 48 weeks

    Secukinumab shows high efficacy irrespective of HLA-Cw6 status in patients with moderate-to-severe plaque-type psoriasis: SUPREME study

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    Background: Understanding genetic variations is important in predicting treatment response and forms the basis for identifying new pharmacogenetic and pharmacogenomic targets for psoriasis treatment. There are limited data on the efficacy of secukinumab in relation to genetic markers. Objectives: To evaluate the efficacy and safety of secukinumab 300 mg in HLA-Cw6-positive (Cw6-POS) and HLA-Cw6-negative (Cw6-NEG) patients with moderate-to-severe chronic plaque-type psoriasis. Methods: SUPREME was a 24-week, phase IIIb study with an extension period up to 72 weeks. Primary end point was Psoriasis Area Severity Index (PASI) 90 response rate after 16 weeks. Results: In total, 434 patients were recruited: 185 (42\ub76%) were Cw6-POS and 246 (56\ub77%) were Cw6-NEG (three not assessed). Mean \ub1 SD age was 45\ub72 \ub1 13\ub72 years (Cw6-POS 42\ub77 \ub1 13\ub71; Cw6-NEG 47\ub72 \ub1 12\ub79). The baseline PASI score was comparable between the cohorts [Cw6-POS 20\ub77 \ub1 8\ub799; Cw6-NEG 21\ub75 \ub1 9\ub799 (P = 0\ub7777)]. At week 16, PASI 90 was achieved in 80\ub74% of Cw6-POS and 79\ub77% of Cw6-NEG patients (difference 0\ub776; 95% confidence interval 127\ub704 to 8\ub723). No differences in absolute PASI at week 16 (Cw6-POS 1\ub736 \ub1 3\ub758; Cw6-NEG 1\ub718 \ub1 2\ub729) were observed. The overall safety profile of secukinumab was consistent with that previously reported. No statistically significant difference was detected in the rate of treatment-emergent adverse events [Cw6-POS 42\ub77%; Cw6-NEG 49\ub76% (P = 0\ub7295)]. A high PASI 90 response was achieved with secukinumab with a fast reduction in absolute PASI. Conclusions: Determination of HLA-Cw6 status for secukinumab therapy is unnecessary, as it is highly effective regardless of HLA-Cw6 status

    Reconstructing extreme AMOC events through nudging of the ocean surface: a perfect model approach

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    While the Atlantic Meridional Overturning Circulation (AMOC) is thought to be a crucial component of the North Atlantic climate, past changes in its strength are challenging to quantify, and only limited information is available. In this study, we use a perfect model approach with the IPSL-CM5A-LR model to assess the performance of several surface nudging techniques in reconstructing the variability of the AMOC. Special attention is given to the reproducibility of an extreme positive AMOC peak from a preindustrial control simulation. Nudging includes standard relaxation techniques towards the sea surface temperature and salinity anomalies of this target control simulation, and/or the prescription of the wind-stress fields. Surface nudging approaches using standard fixed restoring terms succeed in reproducing most of the target AMOC variability, including the timing of the extreme event, but systematically underestimate its amplitude. A detailed analysis of the AMOC variability mechanisms reveals that the underestimation of the extreme AMOC maximum comes from a deficit in the formation of the dense water masses in the main convection region, located south of Iceland in the model. This issue is largely corrected after introducing a novel surface nudging approach, which uses a varying restoring coefficient that is proportional to the simulated mixed layer depth, which, in essence, keeps the restoring time scale constant. This new technique substantially improves water mass transformation in the regions of convection, and in particular, the formation of the densest waters, which are key for the representation of the AMOC extreme. It is therefore a promising strategy that may help to better constrain the AMOC variability and other ocean features in the models. As this restoring technique only uses surface data, for which better and longer observations are available, it opens up opportunities for improved reconstructions of the AMOC over the last few decades
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