1,332 research outputs found
Dynamic formulations of L1 optimal transport problems
The purpose of this work is to analyse the relationships between
different formulations of the Monge-Kantorovich transport problem, in the
case of L 1 cost. In particular, we focus on the famous Benamou and
Brenierâs dynamical formulation, adapting it to our cost function. Helped
by the solutions of the other formulations, we find a way to solve the
dynamical problem, with L 1 cost, and we compare the solution to the one
found by Benamou and Brenier, with L 2 cost. To this aim, we also analyse
the intermediate cases of L p costs, with 1 < p < 2, and work out a
solution procedure based on the nonlinear coupling of a Hamilton-Jacobi
equation with a transport equation. We study the qualitative behavior of
the solutions to the proposed formulations on simple test cases. When
explicit solutions cannot be easily recovered, we use an original numerical
approach based on the Finite Volume discretization of the Hamilton-Jacobi
and the transport equation and solve the nonlinearities by an ad-hoc
adaptation of Newton method.ope
Increased circulating levels of vitamin D binding protein in MS patients
Vitamin D (vitD) low status is currently considered a main environmental factor in multiple sclerosis (MS) etiology and pathogenesis. VitD and its metabolites are highly hydrophobic and circulate mostly bound to the vitamin D binding protein (DBP) and with lower affinity to albumin, while less than 1\% are in a free form. The aim of this study was to investigate whether the circulating levels of either of the two vitD plasma carriers and/or their relationship are altered in MS. We measured DBP and albumin plasma levels in 28 MS patients and 24 healthy controls. MS patients were found to have higher DBP levels than healthy subjects. Concomitant interferon beta therapy did not influence DBP concentration, and the difference with the control group was significant in both females and males. No significant correlation between DBP and albumin levels was observed either in healthy controls or in patients. These observations suggest the involvement of DBP in the patho-physiology of MS
Development and validation of the Remote Working Benefits & Disadvantages scale
The changes that are constantly occurring in the labour sector have led organisations and companies to move towards digital transformation. This process was accelerated by the COVID-19 pandemic and  conducted to a massive recourse to the practice of remote working, which in this study is understood as the term for the way of performing work outside the usual workplace and with the support of ICT. Currently, there are no flexible scales in the literature that allow measuring the benefits and disadvantages of remote working with a single instrument. Thus, the distinction between the positive and negative consequences of working remotely, substantiated by a solid literature, provides a framework for a systematical understanding of the issue. The aim of the present study is to develop and validate a scale on remote working benefits and disadvantages (RW-B&D scale). For this end, a preliminary Exploratory Factor Analysis (EFA) with 304 participants, a tailored EFA with a sample of 301 workers and a Confirmatory Factor Analysis (CFA) with 677 workers were conducted. Participants were all Italian employees who worked remotely during the period of the COVID-19 health emergency. Data were collected between October 2020 and April 2021. The psychometric robustness of the model was assessed through bootstrap validation (5000 resamples), fit indices testing and measurement of factorial invariance. The statistical analyses demonstrated the bifactorial nature of the scale, supporting the research hypothesis. The model showed good fit indices, bootstrap validation reported statistically significant saturations, good reliability indices, and convergent and discriminant validity. Measurement invariance was tested for gender and organisational sector. The results suggested that the novel scale facilitates the quantitative measurement of the benefits and disadvantages associated with remote working in empirical terms. For this reason, it could be a streamlined and psychometrically valid instrument to identify the potential difficulties arising from remote working and, at the same time, the positive aspects that can be implemented to improve organisational well-being
The simplicity project: easing the burden of using complex and heterogeneous ICT devices and services
As of today, to exploit the variety of different "services", users need to configure each of their devices by using different procedures and need to explicitly select among heterogeneous access technologies and protocols. In addition to that, users are authenticated and charged by different means. The lack of implicit human computer interaction, context-awareness and standardisation places an enormous burden of complexity on the shoulders of the final users. The IST-Simplicity project aims at leveraging such problems by: i) automatically creating and customizing a user communication space; ii) adapting services to user terminal characteristics and to users preferences; iii) orchestrating network capabilities. The aim of this paper is to present the technical framework of the IST-Simplicity project. This paper is a thorough analysis and qualitative evaluation of the different technologies, standards and works presented in the literature related to the Simplicity system to be developed
Self-efficacy and work performance: the role of job crafting in middle-age workers
In the last years, the scientific interest on job crafting within the Job demands-resources theory has been increased. The paper aimed to examine the role of job crafting in the relationship between self-efficacy and performance at work. Based on Job demands-resources theory, we hypothesized that employees with higher levels of self-efficacy would be most likely to make proactively changes in their own jobs in order to perform well. Specifically, we hypothesized that job crafting may mediate the positive effects between self-efficacy and work performance and organizational citizenship behaviours. Participants were 361 employees of different Italian organizations. Results from SEM showed the positive effect of self-efficacy on job crafting, work performance, and organizational citizenship behaviours. Furthermore, job crafting partially mediated the relationship between self-efficacy and work performance and totally mediated the relationship between self-efficacy and organizational citizenship behaviours. Findings suggest that job crafting can play a crucial role in the influence of personal resources, as self-efficacy, and the performance at work.
Findings suggest that job crafting can play a crucial role in the influence of personal resources, as self-efficacy, and the performance at work
Muscle quantitative MRI as a novel biomarker in hereditary transthyretin amyloidosis with polyneuropathy: a cross-sectional study
BACKGROUND:
The development of reproducible and sensitive outcome measures has been challenging in hereditary transthyretin (ATTRv) amyloidosis. Recently, quantification of intramuscular fat by magnetic resonance imaging (MRI) has proven as a sensitive marker in patients with other genetic neuropathies. The aim of this study was to investigate the role of muscle quantitative MRI (qMRI) as an outcome measure in ATTRv.
METHODS:
Calf- and thigh-centered multi-echo T2-weighted spin-echo and gradient-echo sequences were obtained in patients with ATTRv amyloidosis with polyneuropathy (nâ=â24) and healthy controls (nâ=â12). Water T2 (wT2) and fat fraction (FF) were calculated. Neurological assessment was performed in all ATTRv subjects. Quantitative MRI parameters were correlated with clinical and neurophysiological measures of disease severity.
RESULTS:
Quantitative imaging revealed significantly higher FF in lower limb muscles in patients with ATTRv amyloidosis compared to controls. In addition, wT2 was significantly higher in ATTRv patients. There was prominent involvement of the posterior compartment of the thighs. Noticeably, FF and wT2 did not exhibit a length-dependent pattern in ATTRv patients. MRI biomarkers correlated with previously validated clinical outcome measures, Polyneuropathy Disability scoring system, Neuropathy Impairment Score (NIS) and NIS-lower limb, and neurophysiological parameters of axonal damage regardless of age, sex, treatment and TTR mutation.
CONCLUSIONS:
Muscle qMRI revealed significant difference between ATTRv and healthy controls. MRI biomarkers showed high correlation with clinical and neurophysiological measures of disease severity making qMRI as a promising tool to be further investigated in longitudinal studies to assess its role at monitoring onset, progression, and therapy efficacy for future clinical trials on this treatable condition
Botulinum Toxin Is Effective in the Management of Neurogenic Dysphagia. Clinical-Electrophysiological Findings and Tips on Safety in Different Neurological Disorders
Background and Aims: Neurogenic dysphagia linked to failed relaxation of the upper esophageal sphincter (UES) can be treated by injecting botulinum toxin (BTX) into the cricopharyngeal (CP) muscle. We compared the effects of this treatment in different neurological disorders with dysphagia, to evaluate its efficacy over time including the response to a second injection. Materials and Methods: Sixty-seven patients with neurogenic dysphagia associated with incomplete or absent opening of the UES (24 with brainstem or hemispheric stroke, 21 with parkinsonian syndromes, 12 with multiple sclerosis, and 10 with spastic-dystonic syndromes secondary to post-traumatic encephalopathy) were treated with the injection of IncobotulinumtoxinA (dose 15â20 U) into the CP muscle under electromyographic guidance. The patients were assessed at baseline and after the first and second treatment through clinical evaluation and fiberoptic endoscopy of swallowing, while their dysphagia was quantified using the Dysphagia Outcome and Severity Scale (DOSS). An electrokinesiographic/electromyographic study of swallowing was performed at baseline. Results: Most patients responded to the first BTX treatment: 35 patients (52.2%) were classified as high responders (DOSS score increase >2 levels), while other 19 patients (28.4%) were low responders (DOSS score increase of â€2 levels). The effect of the first treatment usually lasted longer than 4 months (67%), and in some cases up to a year. The treatment efficacy remained high also after the second injection: 31 patients (46.3%) qualified as high responders and other 22 patients (32.8%) showed a low response. Only in the parkinsonian syndromes group we observed a reduction in the percentage of high responders as compared with the first treatment. Side effects were mostly mild and reported in non-responders following the first injection. A severe side effect, consisting of ingestion pneumonia, was observed following the second BTX injection in two patients who had both been non-responders to the first. Non-responders were characterized electromyographically by higher values of the oropharyngeal interval. Conclusion: These findings confirm the effectiveness of IncobotulinumtoxinA injection in the treatment of neurogenic dysphagia due to hyperactivity and relaxation failure of the UES. Caution should be used as regards, the re-injection in non-responders to the first treatment
Determinants of radiation dose during right transradial access. insights from the RAD-MATRIX study
Background The RAD-MATRIX trial reported a large operator radiation exposure variability in right radial percutaneous coronary procedures. The reasons of these differences are not well understood. Our aim was to appraise the determinants of operator radiation exposure during coronary right transradial procedures. Methods Patient arrangement during transradial intervention was investigated across operators involved in the RAD-MATRIX trial. Operator radiation exposure was analyzed according to the position of the patient right arm (close or far from the body) and in relation to the size of the upper leaded glass. Results Among the 14 operators who agreed to participate, there was a greater than 10-fold difference in radiation dose at thorax level (from 21.5 to 267 ÎŒSv) that persisted after normalization by dose-area product (from 0.35 to 3.5 ÎŒSv/Gy*cm2). Among the operators who positioned the instrumented right arm far from the body (110.4 ÎŒSv, interquartile range 71.5-146.5 ÎŒSv), thorax dose was greater than that in those who placed the instrumented arm close to the right leg (46.1 ÎŒSv, 31.3-56.8 ÎŒSv, P =.02). This difference persisted after normalization by dose-area product (P =.028). The use of a smaller full glass shield was also associated with a higher radiation exposure compared with a larger composite shield (147.5 and 60 ÎŒSv, respectively, P =.016). Conclusions In the context of the biggest radiation study conducted in patients undergoing transradial catheterization, the instrumented right arm arrangement close to the leg and greater upper leaded shield dimensions were associated with a lower operator radiation exposure. Our findings emphasize the importance of implementing simple preventive measures to mitigate the extra risks of radiation exposure with right radial as compared with femoral access
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