52 research outputs found

    A Heat-Jarrow-Morton framework for energy markets: a pragmatic approach

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    In this article we discuss the application of the Heat-Jarrow-Morton framework Heath et al. [26] to energy markets. The goal of the article is to give a detailed overview of the topic, focusing on practical aspects rather than on theory, which has been widely studied in literature. This work aims to be a guide for practitioners and for all those who deal with the practical issues of this approach to energy market. In particular, we focus on the markets' structure, model calibration by dimension reduction with Principal Component Analysis (PCA), Monte Carlo simulations and derivatives pricing. As application, we focus on European power and gas markets: we calibrate the model on historical futures quotations, we perform futures and spot simulations and we analyze the results.Comment: 41 pages, 24 figures, 2 table

    Secure rendezvous and static containment in multi-agent systems with adversarial intruders

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    In this paper we propose a novel distributed local interaction protocol for networks of multi-agent systems (MASs) in a multi-dimensional space under directed time-varying graph with the objective to achieve secure rendezvous or static containment within the convex hull of a set of leader agents. We consider the scenario where a set of anonymous adversarial agents may intrude the network (or may be hijacked by a cyber-attack) and show that the proposed strategy guarantees the achievement of the global objective despite the continued influence of the adversaries which cannot be detected nor identified by the collaborative agents. We characterize the convergence properties of the proposed protocol in terms of the characteristics of the underlying network topology of the multi-agent system. Numerical simulations and examples corroborate the theoretical results

    Development of a versatile tool for the simultaneous differential detection of Pseudomonas savastanoi pathovars by End Point and Real-Time PCR

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    <p>Abstract</p> <p>Background</p> <p><it>Pseudomonas savastanoi </it>pv. <it>savastanoi </it>is the causal agent of olive knot disease. The strains isolated from oleander and ash belong to the pathovars <it>nerii </it>and <it>fraxini</it>, respectively. When artificially inoculated, pv. <it>savastanoi </it>causes disease also on ash, and pv. <it>nerii </it>attacks also olive and ash. Surprisingly nothing is known yet about their distribution in nature on these hosts and if spontaneous cross-infections occur. On the other hand sanitary certification programs for olive plants, also including <it>P. savastanoi</it>, were launched in many countries. The aim of this work was to develop several PCR-based tools for the rapid, simultaneous, differential and quantitative detection of these <it>P. savastanoi </it>pathovars, in multiplex and <it>in planta</it>.</p> <p>Results</p> <p>Specific PCR primers and probes for the pathovars <it>savastanoi</it>, <it>nerii </it>and <it>fraxini </it>of <it>P. savastanoi </it>were designed to be used in End Point and Real-Time PCR, both with SYBR<sup>® </sup>Green or TaqMan<sup>® </sup>chemistries. The specificity of all these assays was 100%, as assessed by testing forty-four <it>P. savastanoi </it>strains, belonging to the three pathovars and having different geographical origins. For comparison strains from the pathovars <it>phaseolicola </it>and <it>glycinea </it>of <it>P. savastanoi </it>and bacterial epiphytes from <it>P. savastanoi </it>host plants were also assayed, and all of them tested always negative. The analytical detection limits were about 5 - 0.5 pg of pure genomic DNA and about 10<sup>2 </sup>genome equivalents per reaction. Similar analytical thresholds were achieved in Multiplex Real-Time PCR experiments, even on artificially inoculated olive plants.</p> <p>Conclusions</p> <p>Here for the first time a complex of PCR-based assays were developed for the simultaneous discrimination and detection of <it>P. savastanoi </it>pv. <it>savastanoi</it>, pv. <it>nerii </it>and pv. <it>fraxini</it>. These tests were shown to be highly reliable, pathovar-specific, sensitive, rapid and able to quantify these pathogens, both in multiplex reactions and <it>in vivo</it>. Compared with the other methods already available for <it>P. savastanoi</it>, the identification procedures here reported provide a versatile tool both for epidemiological and ecological studies on these pathovars, and for diagnostic procedures monitoring the asymptomatic presence of <it>P. savastanoi </it>on olive and oleander propagation materials.</p

    Cancer mortality trend in central Italy. focus on a “low rate of land use” area from 1982 to 2011

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    The aim of the present study was to estimate total cancer mortality trends from 1982 to 2011 in a “low rate of land use” province of the Latium region (Rieti, central Italy) characterized by a low degree of urbanization, a high prevalence of elderly, and a low number of births. Mortality data of the studied period, provided by the Italian National Institute of Statistics, were used for calculating standardized cancer mortality rates. Trends in mortality were analyzed using Joinpoint regression analysis. Results showed that total standardized cancer mortality rates decreased in the monitored area over the study period. A comparison with other provinces of the same region evidenced that the studied province presented the lowest cancer mortality. The three systems/apparatuses affected by cancer that mainly influenced cancer mortality in the monitored province were the trachea-bronchus-lung, colorectal-anus, and stomach. These findings could be attributed to the implement of preventive initiatives performed in the early 2000s, to healthier environmental scenario, and to lower levels of carcinogenic pollutants in air, water, and soil matrices. Thus, our results indicate that the studied area could be considered a “healthy” benchmark for studies in oncological diseases

    Virological and immunological features of SARS-CoV-2-infected children who develop neutralizing antibodies

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    As the global COVID-19 pandemic progresses, it is paramount to gain knowledge on adaptive immunity to SARS-CoV-2 in children to define immune correlates of protection upon immunization or infection. We analyzed anti-SARS-CoV-2 antibodies and their neutralizing activity (PRNT) in 66 COVID-19-infected children at 7 (\ub12) days after symptom onset. Individuals with specific humoral responses presented faster virus clearance and lower viral load associated with a reduced in&nbsp;vitro infectivity. We demonstrated that the frequencies of SARS-CoV-2-specific CD4+CD40L+ T&nbsp;cells and Spike-specific B cells were associated with the anti-SARS-CoV-2 antibodies and the magnitude of neutralizing activity. The plasma proteome confirmed the association between cellular and humoral SARS-CoV-2 immunity, and PRNT+ patients show higher viral signal transduction molecules (SLAMF1, CD244, CLEC4G). This work sheds lights on cellular and humoral anti-SARS-CoV-2 responses in children, which may drive future vaccination trial endpoints and quarantine measures policies

    Predictors of DAPSA Response in Psoriatic Arthritis Patients Treated with Apremilast in a Retrospective Observational Multi-Centric Study (2023-02-07)

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    Background: To date, only a few real-world-setting studies evaluated apremilast effectiveness in psoriatic arthritis (PsA). The aims of this retrospective observational study are to report long-term Disease Activity Index for Psoriatic Arthritis (DAPSA) response of apremilast in PsA patients and to analyze the predictors of clinical response. Methods: All PsA consecutive patients treated with apremilast in fifteen Italian rheumatological referral centers were enrolled. Anamnestic data, treatment history, and PsA disease activity (DAPSA) at baseline, 6 months, and 12 months were recorded. The Mann–Whitney test and chi-squared tests assessed the differences between independent groups, whereas the Wilcoxon matched pairs signed-rank test assessed the differences between dependent samples. Logistic regressions verified if there were factors associated with achievement of DAPSA low disease activity or remission at 6 and 12 months. Results: DAPSA low disease activity or remission rates at 6 and 12 months were observed, respectively, in 42.7% (n = 125) and 54.9% (n = 161) patients. Baseline DAPSA was inversely associated with the odds of achieving low disease activity or remission at 6 months (odds ratio (OR) 0.841, 95% confidence interval (CI) 0.804–0.879; p &lt; 0.01) and at 12 months (OR 0.911, 95% CI 0.883–0.939; p &lt; 0.01). Conclusions: Almost half of the PsA patients receiving apremilast achieved DAPSA low disease activity or remission at 6 and 12 months. The only factor associated with achievement of low disease activity or remission at both 6 and 12 months was baseline DAPSA

    Serum Albumin Is Inversely Associated With Portal Vein Thrombosis in Cirrhosis

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    We analyzed whether serum albumin is independently associated with portal vein thrombosis (PVT) in liver cirrhosis (LC) and if a biologic plausibility exists. This study was divided into three parts. In part 1 (retrospective analysis), 753 consecutive patients with LC with ultrasound-detected PVT were retrospectively analyzed. In part 2, 112 patients with LC and 56 matched controls were entered in the cross-sectional study. In part 3, 5 patients with cirrhosis were entered in the in vivo study and 4 healthy subjects (HSs) were entered in the in vitro study to explore if albumin may affect platelet activation by modulating oxidative stress. In the 753 patients with LC, the prevalence of PVT was 16.7%; logistic analysis showed that only age (odds ratio [OR], 1.024; P = 0.012) and serum albumin (OR, -0.422; P = 0.0001) significantly predicted patients with PVT. Analyzing the 112 patients with LC and controls, soluble clusters of differentiation (CD)40-ligand (P = 0.0238), soluble Nox2-derived peptide (sNox2-dp; P &lt; 0.0001), and urinary excretion of isoprostanes (P = 0.0078) were higher in patients with LC. In LC, albumin was correlated with sCD4OL (Spearman's rank correlation coefficient [r(s)], -0.33; P &lt; 0.001), sNox2-dp (r(s), -0.57; P &lt; 0.0001), and urinary excretion of isoprostanes (r(s), -0.48; P &lt; 0.0001) levels. The in vivo study showed a progressive decrease in platelet aggregation, sNox2-dp, and urinary 8-iso prostaglandin F2 alpha-III formation 2 hours and 3 days after albumin infusion. Finally, platelet aggregation, sNox2-dp, and isoprostane formation significantly decreased in platelets from HSs incubated with scalar concentrations of albumin. Conclusion: Low serum albumin in LC is associated with PVT, suggesting that albumin could be a modulator of the hemostatic system through interference with mechanisms regulating platelet activation

    Rationale and design of an independent randomised controlled trial evaluating the effectiveness of aripiprazole or haloperidol in combination with clozapine for treatment-resistant schizophrenia

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    <p>Abstract</p> <p>Background</p> <p>One third to two thirds of people with schizophrenia have persistent psychotic symptoms despite clozapine treatment. Under real-world circumstances, the need to provide effective therapeutic interventions to patients who do not have an optimal response to clozapine has been cited as the most common reason for simultaneously prescribing a second antipsychotic drug in combination treatment strategies. In a clinical area where the pressing need of providing therapeutic answers has progressively increased the occurrence of antipsychotic polypharmacy, despite the lack of robust evidence of its efficacy, we sought to implement a pre-planned protocol where two alternative therapeutic answers are systematically provided and evaluated within the context of a pragmatic, multicentre, independent randomised study.</p> <p>Methods/Design</p> <p>The principal clinical question to be answered by the present project is the relative efficacy and tolerability of combination treatment with clozapine plus aripiprazole compared with combination treatment with clozapine plus haloperidol in patients with an incomplete response to treatment with clozapine over an appropriate period of time. This project is a prospective, multicentre, randomized, parallel-group, superiority trial that follow patients over a period of 12 months. Withdrawal from allocated treatment within 3 months is the primary outcome.</p> <p>Discussion</p> <p>The implementation of the protocol presented here shows that it is possible to create a network of community psychiatric services that accept the idea of using their everyday clinical practice to produce randomised knowledge. The employed pragmatic attitude allowed to randomly allocate more than 100 individuals, which means that this study is the largest antipsychotic combination trial conducted so far in Western countries. We expect that the current project, by generating evidence on whether it is clinically useful to combine clozapine with aripiprazole rather than with haloperidol, provides physicians with a solid evidence base to be directly applied in the routine care of patients with schizophrenia.</p> <p>Trial Registration</p> <p><b>Clincaltrials.gov Identifier</b>: NCT00395915</p

    Multitask Prompted Training Enables Zero-Shot Task Generalization

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    International audienceLarge language models have recently been shown to attain reasonable zero-shot generalization on a diverse set of tasks (Brown et al., 2020). It has been hypothesized that this is a consequence of implicit multitask learning in language models’ pretraining (Radford et al., 2019). Can zero-shot generalization instead be directly induced by explicit multitask learning? To test this question at scale, we develop a system for easily mapping any natural language tasks into a human-readable prompted form. We convert a large set of supervised datasets, each with multiple prompts with diverse wording. These prompted datasets allow for benchmarking the ability of a model to perform completely held-out tasks. We fine-tune a pre-trained encoder-decoder model (Raffel et al., 2020; Lester et al., 2021) on this multitask mixture covering a wide variety of tasks. The model attains strong zero-shot performance on several standard datasets, often outperforming models up to 16x its size. Further, our approach attains strong performance on a subset of tasks from the BIG-bench benchmark, outperforming models up to 6x its size. All trained models are available at https://github.com/bigscience-workshop/t-zero, and all prompts are available at https://github.com/bigscience-workshop/promptsource
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