Near-surface eddy dynamics in the southern ocean

The Antarctic Circumpolar Current (ACC) is a crucial component of the global ocean conveyor belt, acting as a zonal link among the major ocean basins but, to some extent, limiting meridional exchange and tending to isolate the ocean south of it from momentum and heat income. In this work we investigate one of the most important mechanisms contributing to the poleward transfer of properties in the Southern Ocean, that is the eddy component of the dynamics. For this particular purpose, observations obtained from near-surface drifters have been used: they represent a very useful data set to analyse the eddy field because of their ability to catch a large number of scales of motion while providing a quasi-synoptic coverage of the investigated area. Estimates of the eddy heat and momentum fluxes are carried out using data taken from the Global Drifter Program databank; they refer to Surface Velocity Program drifter trajectories collected in the area south of 35°S between 1995 and 2006. Eddy kinetic energies, variance ellipses, momentum and heat fluxes have been calculated using the pseudo-Eulerian method, showing patterns in good agreement with those present in the literature based on observational and model data, although there are some quantitative differences. The eddy fluxes have been separated into their rotational and divergent portions, the latter being responsible for the meridional transports. The associated zonal and depth-exponentially integrated meridional heat transport exhibits values spanning over a range between -0.4 PW and -1.1 PW in the ACC region, consistent with previous estimates. © 2011 M. Trani et al

Pandemic influenza A/H1N1 virus in a swine farm house in Sicily, Italy

This report describes a pandemic A/H1N1 (H1N1 pdm) virus outbreak occurred in December, 2009 in a swine farm used as research facility (Istituto Mediterraneo Trapianti e Terapie ad Alta Specializzazione) for preclinical studies, located in Sicily, Italy. All the 13 pigs of the farm, showed cough, fever, inappetence and weakness. At the same time, an unvaccinated worker of the stabling showed influenza-like symptoms. RNAv extracted from two swabs collected from infected pigs resulted positive by Real Time RT-PCR for Influenza A virus. Furthermore, after growth on embryonated eggs, viral isolates were identified by Real Time RT-PCR specific for H1N1 pdm virus and characterized antigenically. Sequencing of the whole genome was also performed. All sera taken from animals and from the worker were tested by a competitive Influenza A ELISA and by the haemoagglutination inhibition test. Serological findings confirmed the circulation of influenza virus H1N1 pdm in pigs and the presence of specific antibodies against H1N1 pdm in human serum. The results of this study seem to support a H1N1 pdm transmission from man to animals showing the importance of serological and virological investigation to control the pig farms and the importance of close cooperation between the different authorities like veterinarian and human public. © 2012 Triveni Enterprises

Long-term clinical impact of permanent pacemaker implantation in patients undergoing transcatheter aortic valve implantation: a systematic review and meta-analysis

AIMS: The aims of this study is to assess by an updated meta-analysis the clinical outcomes related to permanent pacemaker implantation (PPI) after transcatheter aortic valve implantation (TAVI) at long-term (≥12 months) follow-up (LTF). METHODS AND RESULTS: A comprehensive literature research was performed on PubMed and EMBASE. The primary endpoint was all-cause death. Secondary endpoints were rehospitalization for heart failure, stroke, and myocardial infarction. A subgroup analysis was performed according to the Society of Thoracic Surgeon-Predicted Risk of Mortality (STS-PROM) score. This study is registered with PROSPERO (CRD42021243301). A total of 51 069 patients undergoing TAVI from 31 observational studies were included. The mean duration of follow-up was 22 months. At LTF, PPI post-TAVI was associated with a higher risk of all-cause death [risk ratio (RR) 1.18, 95% confidence interval (CI) 1.10-1.25; P < 0.001] and rehospitalization for heart failure (RR 1.32, 95% CI 1.13-1.52; P < 0.001). In contrast, the risks of stroke and myocardial infarction were not affected. Among the 20 studies that reported procedural risk, the association between PPI and all-cause death risk at LTF was statistically significant only in studies enrolling patients with high STS-PROM score (RR 1.25, 95% CI 1.12-1.40), although there was a similar tendency of the results in those at medium and low risk. CONCLUSION: Patients necessitating PPI after TAVI have a higher long-term risk of all-cause death and rehospitalization for heart failure as compared to those who do not receive PPI

Adiabatic description of nonspherical quantum dot models

Within the effective mass approximation an adiabatic description of spheroidal and dumbbell quantum dot models in the regime of strong dimensional quantization is presented using the expansion of the wave function in appropriate sets of single-parameter basis functions. The comparison is given and the peculiarities are considered for spectral and optical characteristics of the models with axially symmetric confining potentials depending on their geometric size making use of the total sets of exact and adiabatic quantum numbers in appropriate analytic approximations

Clinical-genetic features and peculiar muscle histopathology in infantile DNM1L-related mitochondrial epileptic encephalopathy

Mitochondria are highly dynamic organelles, undergoing continuous fission and fusion. The DNM1L gene encodes for the DRP1 protein, an evolutionary conserved member of the dynamin family, responsible for fission of mitochondria, and having a role in the division of peroxisomes, as well. DRP1 impairment is implicated in several neurological disorders and associated with either de novo dominant or compound heterozygous mutations. In five patients presenting with severe epileptic encephalopathy we identified 5 de novo dominant DNM1L variants, the pathogenicity of which was validated in a yeast model. Fluorescence microscopy revealed abnormally elongated mitochondria and aberrant peroxisomes in mutant fibroblasts, indicating impaired fission of these organelles. Moreover, a very peculiar finding in our cohort of patients was the presence, in muscle biopsy, of core like areas with oxidative enzyme alterations, suggesting an abnormal distribution of mitochondria in the muscle tissue