W-algebras from symplectomorphisms

It is shown how $W$-algebras emerge from very peculiar canonical transformations with respect to the canonical symplectic structure on a compact Riemann surface. The action of smooth diffeomorphisms of the cotangent bundle on suitable generating functions is written in the BRS framework while a $W$-symmetry is exhibited. Subsequently, the complex structure of the symmetry spaces is studied and the related BRS properties are discussed. The specific example of the so-called $W_3$-algebra is treated in relation to some other different approaches.Comment: LaTex, 25 pages, no figures, to appear in Journ. Math. Phy

Spectral Line Removal in the LIGO Data Analysis System (LDAS)

High power in narrow frequency bands, spectral lines, are a feature of an interferometric gravitational wave detector's output. Some lines are coherent between interferometers, in particular, the 2 km and 4 km LIGO Hanford instruments. This is of concern to data analysis techniques, such as the stochastic background search, that use correlations between instruments to detect gravitational radiation. Several techniques of `line removal' have been proposed. Where a line is attributable to a measurable environmental disturbance, a simple linear model may be fitted to predict, and subsequently subtract away, that line. This technique has been implemented (as the command oelslr) in the LIGO Data Analysis System (LDAS). We demonstrate its application to LIGO S1 data.Comment: 11 pages, 5 figures, to be published in CQG GWDAW02 proceeding

Analysis of a Motocross Knee Brace: From the Real Model to the Numerical Finite Element Model via 3D Scanning and Reverse Engineering

Featured Application: This study outlines a novel procedure for the Finite Element Modelling and Analysis of motocross knee braces under race conditions. The aim is to quantitatively evaluate the effectiveness of such stabilisers in reducing the risk and consequences of musculoskeletal injuries, considering the current lack of industrial standards and dedicated scientific research works. Musculoskeletal injuries often occur when performing motocross; almost half of the overall ligamentous injuries (42%) are knee ligaments injuries. Lesions can be greatly reduced with knee braces. Commercial knee braces are expected to oppose and limit unwanted and potentially harmful movements such as hyperextension and excessive rotation of the knee joint. However, this aspect has not been fully investigated from a biomechanical point of view. This would require proper Finite Element Modelling (FEM) and Analysis (FEA). However, to perform FEA and evaluate the efficacy of the brace simulating sportive conditions, numerical models need to be built. It requires a dedicated setup and several preprocessing steps, for which no industrial standard or widely accepted better practise is available as of today. Firstly, the brace and the lower limb are scanned using a 3D scanner. The geometry is reconstructed using reverse engineering techniques. These allow us to obtain a smooth, reliable 3D model starting from the points cloud acquired during scanning. A lower limb model was created using a mixed approach, combining MRI data and 3D scanning. Finally, a simulation of the impact condition after a jump using the developed model was carried out

A systematic review opens the black box of “usual care” in stroke rehabilitation control groups and finds a black hole

INTRODUCTION: In experimental trials, new methods are tested against the “best” or “usual” care. To appraise control group (CG) interventions provided as “usual care,” we focused on stroke as a leading cause of disability demanding rehabilitation as a complex intervention. EVIDENCE ACQUISITION: For this methodological appraisal, we conducted a systematic review of RCTs without timespan limitation. The PICO included stroke survivors, rehabilitation, control group intervention, lower limb function. To assess the risk of bias, we used the Cochrane risk of bias tool (RoB). we identified the terminology describing the CG Program (CGP), performed a knowledge synthesis and conducted a frequency analysis of provided interventions. EVIDENCE SYNTHESIS: we included 155 publications. 13.6% of the articles did not describe the CG, and 11.6% indicated only the professionals involved. In the remaining 116 studies, three studies provided an intervention according to specific guidelines, 106 different “usual care” CGPs were detected, with nine proposed twice and two between four and five times. The most adopted terminology to state “usual care” was “conventional physiotherapy.” CONCLUSIONS: This study shows that usual care in CG does not actually exist, as both specific terminology and consistency within CGP contents are missing. Reporting guidelines should give better assistance on this issue. These results should be verified in other fields

Laparoscopic distal pancreatectomy in Italy: A systematic review and meta-analysis

Background The use of laparoscopic distal pancreatectomy (LDP) increased in the past twenty years but the real diffusion of this technique is still unknown as well as the type of centers (high or low volume) in which this procedure is more frequently performed. Data Source A systematic review was performed to evaluate the frequency of LDP in Italy and to compare indications and results in high volume centers (HVCs) and in low volume centers (LVCs). Results From 95 potentially relevant citations identified, only 5 studies were included. A total of 125 subjects were analyzed, of whom 95 (76.0%) were from HVCs and 30 (24.0%) from LVCs. The mean number of LDPs performed per year was 6.5. The mean number of patients who underwent LDP per year was 8.8 in HVCs and 3.0 in LVCs (P<0.001). The most frequent lesions operated on in HVCs were cystic tumors (62.1%, P<0.001) while, in LVCs, solid neoplasms (76.7%, P<0.001). In HVCs, malignant neoplasms were treated with LDP less frequently than in LVCs (17.9% vs 50.0%, P<0.001). Splenectomy was performed for non-oncologic reason frequenter in HVCs than in LVCs (70.2% vs 25.0%, P=0.004). The length of stay was shorter in HVCs than in LVCs (7.5 vs 11.3, P<0.001). No differences were found regarding age, gender, ductal adenocarcinoma treated, operative time, conversion, morbidity, postoperative pancreatic fistula, reoperation and margin status. Conclusions LDPs were frequently performed in Italy. The "HVC approach" is characterized by a careful selection of patients undergoing LDP. The "LVC approach" is based on the hypothesis that LDPs are equivalent both in short-term and long-term results to laparotomic approach. These data are not conclusive and they point out the need for a national register of laparoscopic pancreatectomy

In-doped Sb nanowires grown by MOCVD for high speed phase change memories

We investigated the Phase Change Memory (PCM) capabilities of In-doped Sb nanowires (NWs) with diameters of (20-40) nm, which were self-assembled by Metalorganic Chemical Vapor Deposition (MOCVD) via the vapor-liquid-solid (VLS) mechanism. The PCM behavior of the NWs was proved, and it was shown to have relatively low reset power consumption (~ 400 μW) and fast switching capabilities with respect to standard Ge-Sb-Te based devices. In particular, reversible set and reset switches by voltage pulses as short as 25 ns were demonstrated. The obtained results are useful for understanding the effects of downscaling in PCM devices and for the exploration of innovative PCM architectures and materials

Vitamin d3 enriches ceramide content in exosomes released by embryonic hippocampal cells

The release of exosomes can lead to cell\u2013cell communication. Nutrients such as vitamin D3 and sphingolipids have important roles in many cellular functions, including proliferation, dif-ferentiation, senescence, and cancer. However, the specific composition of sphingolipids in exo-somes and their changes induced by vitamin D3 treatment have not been elucidated. Here, we ini-tially observed neutral sphingomyelinase and vitamin D receptors in exosomes released from HN9.10 embryonic hippocampal cells. Using ultrafast liquid chromatography tandem mass spec-trometry, we showed that exosomes are rich in sphingomyelin species compared to whole cells. To interrogate the possible functions of vitamin D3, we established the optimal conditions of cell treatment and we analyzed exosome composition. Vitamin D3 was identified as responsible for the vitamin D receptor loss, for the increase in neutral sphingomyelinase content and sphingomyelin changes. As a consequence, the generation of ceramide upon vitamin D3 treatment was evident. Incubation of the cells with neutral sphingomyelinase, or the same concentration of ceramide pro-duced in exosomes was necessary and sufficient to stimulate embryonic hippocampal cell differen-tiation, as vitamin D3. This is the first time that exosome ceramide is interrogated for mediate the effect of vitamin D3 in inducing cell differentiation

In-doped Sb nanowires grown by MOCVD for high speed phase change memories

We investigated the Phase Change Memory (PCM) capabilities of In-doped Sb nanowires (NWs) with diameters of (20-40) nm, which were self-assembled by Metalorganic Chemical Vapor Deposition (MOCVD) via the vapor-liquid-solid (VLS) mechanism. The PCM behavior of the NWs was proved, and it was shown to have relatively low reset power consumption (~ 400 μW) and fast switching capabilities with respect to standard Ge-Sb-Te based devices. In particular, reversible set and reset switches by voltage pulses as short as 25 ns were demonstrated. The obtained results are useful for understanding the effects of downscaling in PCM devices and for the exploration of innovative PCM architectures and materials. Keywords: Phase change memories, Nanowires, MOCVD, In-Sb, TEM, XR

Can we improve the treatment of congestion in heart failure?

INTRODUCTION: Dyspnoea and peripheral oedema, caused by fluid redistribution to the lungs and/or by fluid overload, are the main causes of hospitalization in patients with heart failure and are associated with poor outcomes. Treatment of fluid overload should relieve symptoms and have a neutral or favorable effect on outcomes. AREAS COVERED: We first consider the results obtained with furosemide administration, which is still the mainstay of treatment of congestion in patients with heart failure. We then discuss important shortcomings of furosemide treatment, including the development of resistance and side effects (electrolyte abnormalities, neurohormonal activation, worsening renal function), as well as the relationship of furosemide - and its doses - with patient prognosis. Finally, the results obtained with potential alternatives to furosemide treatment, including different modalities of loop diuretic administration, combined diuretic therapy, dopamine, inotropic agents, ultrafiltration, natriuretic peptides, vasopressin and adenosine antagonists, are discussed. EXPERT OPINION: Relief of congestion is a major objective of heart failure treatment but therapy remains based on the administration of furosemide, an agent that is often not effective and is associated with poor outcomes. The results of the few controlled studies aimed at the assessment of new treatments to overcome resistance to furosemide and/or to protect the kidney from its untoward effects have been mostly neutral. Better treatment of congestion in heart failure remains a major unmet need