533 research outputs found

    Use of Cellular Automata Modelling Approaches to Understand Potential Impacts of GM Grasses on Grassland Communities

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    In order to predict the potential unintended ecological impacts of genetically modified (GM) grasses, we must understand how the engineered traits, in this case herbicide resistance, are expressed in an ecological context. It would be a daunting task to experimentally evaluate the full multiplicity of potential pair-wise interactions between GM plants and native plants under a broad variety of actual environmental conditions. We have employed the modelling methodology of cellular automata (CA), where a plant\u27s distribution within a two-dimensional environmental grid is determined by rules relating to phenomena such as seed dispersal, clonal expansion and interactions with adjacent plants. We have used CA simulation to model interactions between GM grasses and the natural environment by describing the plants and the effect of the GM trait in terms of plant functional types. This approach takes the external factors which limit the amount of plant material present in any habitat and classifies them into two categories: (1) stress, defined with regard to the availability of nutrients and (2) disturbance, which refers to the destruction of plant material. The ecological characteristics of all the plants can be described based on three functional types C (competitor), S (stress-tolerator) and R (ruderal) as determined by their quantifiable physiological relationships to stress and disturbance. By ascribing the large number of plant ecological characteristics to a smaller number of functional types the problem, of describing how the engineered trait of herbicide resistance is expressed in an ecological context, becomes tractable

    Estimate of the impact of background particles on the X-Ray Microcalorimeter Spectrometer on IXO

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    We present the results of a study on the impact of particles of galactic (GCR) and solar origin for the X-ray Microcalorimeter Spectrometer (XMS) aboard an astronomical satellite flying in an orbit at the second Lagrangian point (L2). The detailed configuration presented in this paper is the one adopted for the International X-Ray Observatory (IXO) study, however the derived estimates can be considered a conservative limit for ATHENA, that is the IXO redefined mission proposed to ESA. This work is aimed at the estimate of the residual background level expected on the focal plane detector during the mission lifetime, a crucial information in the development of any instrumental configuration that optimizes the XMS scientific performances. We used the Geant4 toolkit, a Monte Carlo based simulator, to investigate the rejection efficiency of the anticoincidence system and assess the residual background on the detector.Comment: 18 pages, 9 figure

    Carbon nanotube four-terminal devices for pressure sensing applications

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    Carbon nanotubes (CNTs) are of high interest for sensing applications,owing to their superior mechanical strength, high Young’s modulus and low density. In this work, we report on a facile approach for the fabrication of carbon nanotube devices using a four terminal configuration. Oriented carbon nanotube films were pulled out from a CNT forest wafer and then twisted into a yarn. Both the CNT film and yarn were arranged on elastomer membranes/diaphragms which were arranged on a laser cut acrylic frame to form pressure sensors. The sensors were calibrated using a precisely controlled pressure system, showing a large change of the output voltage of approximately 50 mV at a constant supply current of 100 μA and under a low applied pressure of 15 mbar. The results indicate the high potential of using CNT films and yarns for pressure sensing applications

    How to improve compliance with protective health measures during the covid-19 outbreak. Testing a moderated mediation model and machine learning algorithms

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    In the wake of the sudden spread of COVID-19, a large amount of the Italian population practiced incongruous behaviors with the protective health measures. The present study aimed at examining psychological and psychosocial variables that could predict behavioral compliance. An online survey was administered from 18–22 March 2020 to 2766 participants. Paired sample t-tests were run to compare efficacy perception with behavioral compliance. Mediation and moderated mediation models were constructed to explore the association between perceived efficacy and compliance, mediated by self-efficacy and moderated by risk perception and civic attitudes. Machine learning algorithms were trained to predict which individuals would be more likely to comply with protective measures. Results indicated significantly lower scores in behavioral compliance than efficacy perception. Risk perception and civic attitudes as moderators rendered the mediating effect of self-efficacy insignificant. Perceived efficacy on the adoption of recommended behaviors varied in accordance with risk perception and civic engagement. The 14 collected variables, entered as predictors in machine learning models, produced an ROC area in the range of 0.82–0.91 classifying individuals as high versus low compliance. Overall, these findings could be helpful in guiding age-tailored information/advertising campaigns in countries affected by COVID-19 and directing further research on behavioral compliance

    A 2-month follow-up study of psychological distress among italian people during the covid-19 lockdown

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    The spread of coronavirus disease 2019 (COVID-19) has called for unprecedented measures, including a national lockdown in Italy. The present study aimed at identifying psychological changes (e.g., changes in depression, stress, and anxiety levels) among the Italian public during the lockdown period, in addition to factors associated with these changes. An online follow-up survey was administered to 439 participants (original sample = 2766), between 28 April and 3 May 2020. A paired sample t-test tested for differences in stress, anxiety, and depression over the period. Multivariate regression models examined associations between sociodemographic variables, personality traits, coping strategies, depression, and stress. Results showed an increase in stress and depression over the lockdown, but not anxiety. Negative affect and detachment were associated with higher levels of depression and stress. Higher levels of depression at the start of the lockdown, as well as fewer coping strategies and childlessness, were associated with increased depression at follow-up, whereas higher levels of stress at the start of the lockdown and younger age were associated with higher stress at follow-up. These results may help us to identify persons at greater risk of suffering from psychological distress as a result lockdown conditions, and inform psychological interventions targeting post-traumatic symptoms

    L-DOPA preloading increases the uptake of borophenylalanine in C6 glioma rat model: a new strategy to improve BNCT efficacy.

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    Purpose: Boron neutron capture therapy (BNCT) is a radiotherapeutic modality based on 10B(n,a)7Li reaction, for the treatment of malignant gliomas. One of the main limitations for BNCT effectiveness is the insufficient intake of 10B nuclei in the tumor cells. This work was aimed at investigating the use of L-DOPA as a putative enhancer for 10B-drug 4-dihydroxy-borylphenylalanine (BPA) uptake in the C6-glioma model. The investigation was first per- formed in vitro and then extended to the animal model. Methods and Materials: BPA accumulation in C6-glioma cells was assessed using radiowave dielectric spectros- copy, with and without L-DOPA preloading. Two L-DOPA incubation times (2 and 4 hours) were investigated, and the corresponding effects on BPA accumulation were quantified. C6-glioma cells were also implanted in the brain of 32 rats, and tumor growth was monitored by magnetic resonance imaging. Rats were assigned to two experimental branches: (1) BPA administration; (2) BPA administration after pretreatment with L-DOPA. All an- imals were sacrificed, and assessments of BPA concentrations in tumor tissue, normal brain, and blood samples were performed using high-performance liquid chromatography. Results: L-DOPA preloading induced a massive increase of BPA concentration in C6-glioma cells only after a 4-hour incubation. In the animal model, L-DOPA pretreatment produced a significantly higher accumulation of BPA in tumor tissue but not in normal brain and blood samples. Conclusions: This study suggests the potential use of L-DOPA as enhancer for BPA accumulation in malig- nant gliomas eligible for BNCT. L-DOPA preloading effect is discussed in terms of membrane transport mechanisms

    La Rete Sismica Mobile del Centro Nazionale Terremoti

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    Il monitoraggio sismico e vulcanico del territorio nazionale rappresenta uno dei principali compiti istituzionali dell’Istituto Nazionale di Geofisica e Vulcanologia (INGV). L’INGV svolge tale importante funzione attraverso la gestione e la manutenzione di reti sismiche di diversa tipologia e a differente scala che consentono di monitorare il territorio nazionale in tempo reale. Tre sale di sorveglianza, una sismica presso la sede centrale di Roma e due vulcaniche presso la Sezione di Catania e l’Osservatorio Vesuviano di Napoli, con personale qualificato in turno H24, consentono di elaborare e comunicare tempestivamente al Dipartimento della Protezione Civile Nazionale (DPC) e alle sue strutture regionali eventuali stati di allarme e il livello dell’emergenza. Il Centro Nazionale Terremoti (CNT) è la sezione dell’INGV preposta al monitoraggio sismico del territorio italiano ed interviene in questo importante servizio attraverso la gestione e la manutenzione della Rete Sismica Nazionale (RSN) in collaborazione con le altre sedi dell’INGV dislocate sul territorio e con gli uffici tecnici locali. Competenza del CNT è anche la rete sismica euro-mediterranea (MedNet): una rete di stazioni sismiche a larga banda dislocate nei Paesi che circondano il Mediterraneo in condivisione con molti istituti geofisici. Negli ultimi anni tali reti sono cresciute sia come numero di stazioni che come tecnologia, consentendo di controllare in maniera estesa lo spettro di frequenze emesse dalla sorgente sismica e la ciclicità delle strutture sismogenetiche. In alcune aree del territorio nazionale l’alta densità di tali reti sismiche rende possibile una soglia di detezione degli eventi molto bassa e localizzazioni di elevata precisione che permettono di associare la micro-sismicità alle strutture sismo-genetiche. Tuttavia questo non è tecnicamente ed economicamente possibile in maniera omogenea su tutto il territorio nazionale. Per tale motivo si fa spesso ricorso all’uso di reti temporanee in esperimenti mirati allo studio di aree a peculiare rischio sismico e vulcanico o, in caso di forti terremoti, per aumentare la densità della rete già presente e migliorare il monitoraggio in real-time in modo tale da analizzare con maggior dettaglio l’evoluzione della sequenza. Unità specializzate nella gestione di reti sismologiche temporanee sono presenti in diverse sedi dell’INGV. Esse lavorano in completa autonomia sul territorio di competenza ma sono in grado di realizzare un buon livello di sinergia là dove esperimenti ed emergenze sismiche richiedano una stretta collaborazione. La struttura più grande, sia come numero di strumenti a disposizione (più di 200 tra digitalizzatori e sensori) che come personale impegnato, è la Rete Sismica Mobile (RSM) del CNT che è organizzata in modo da rendere possibile l’impiego della strumentazione in più esperimenti mantenendo una quota di strumenti riservata per gli interventi di emergenza. In questo rapporto tecnico presentiamo la struttura organizzativa ed operativa della RSM del CNT, la strumentazione in uso presso di essa e le diverse configurazioni possibili per le stazioni sismometriche temporanee con l’obiettivo di fornire un manuale d’uso ai ricercatori, tecnologi e tecnici che si interfacciano con la RSM, sia durante l’attività scientifica ordinaria (esperimenti di sismica passiva e attiva) che straordinaria (emergenze sismiche)

    Monte-Carlo Simulations of the Suzaku-XRS Residual Background Spectrum

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    Cryogenic micro-calorimeters are suitable to detect small amounts of energy deposited by electromagnetic and nuclear interactions, which makes them attractive in a variety of applications on ground and in space. The only X-ray microcalorimeter that operated in orbit to date is the X-Ray Spectrometer on-board of the Japanese Suzaku satellite. We discuss the analysis of the components of its residual background spectrum with the support of Monte-Carlo simulations

    La campagna sismica del progetto “Alto Adriatico”. Rapporto delle attività 2010-2011

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    Istituto Nazionale di Geofisica e VulcanologiaPublished1-401.1. TTC - Monitoraggio sismico del territorio nazionaleN/A or not JCRope

    Factors impacting time to total shoulder arthroplasty among patients with primary glenohumeral osteoarthritis and rotator cuff arthropathy managed conservatively with corticosteroid injections

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    Background The purpose of this study was to identify predictors of the time from initial presentation to total shoulder arthroplasty (TSA) in patients with primary glenohumeral osteoarthritis (OA) and rotator cuff (RTC) arthropathy who were conservatively managed with corticosteroid injections. Methods We conducted a retrospective cohort study of patients who underwent TSA from 2010 to 2021. Kaplan-Meier survival analysis was used to estimate median time to TSA for primary OA and RTC arthropathy patients. The Cox proportional hazards model was used to identify significant predictors of time to TSA and to calculate hazard ratios (HRs) with 95% confidence intervals (CIs). Statistical significance was set at P<0.05. Results The cohort included 160 patients with primary OA and 92 with RTC arthropathy. In the primary OA group, median time to TSA was 15 months. Significant predictors of shorter time to TSA were older age at presentation (HR, 1.02; 95% CI, 1.00–1.04; P=0.03) and presence of moderate or severe acromioclavicular joint arthritis (HR, 1.45; 95% CI, 1.05–2.01; P=0.03). In the RTC arthropathy group, median time to TSA was 14 months, and increased number of corticosteroid injections was associated with longer time to TSA (HR, 0.87; 95% CI, 0.80–0.95; P=0.003). Conclusions There are distinct prognostic factors for progression to TSA between primary OA patients and RTC arthropathy patients managed with corticosteroid injections. Multiple corticosteroid injections are associated with delayed time to TSA in RTC arthropathy patients. Level of evidence III
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