120 research outputs found
Exotic atoms at extremely high magnetic fields: the case of neutron star atmosphere
The presence of exotic states of matter in neutron stars (NSs) is currently
an open issue in physics. The appearance of muons, kaons, hyperons, and other
exotic particles in the inner regions of the NS, favored by energetic
considerations, is considered to be an effective mechanism to soften the
equation of state (EoS). In the so-called two-families scenario, the softening
of the EoS allows for NSs characterized by very small radii, which become
unstable and convert into a quark stars (QSs). In the process of conversion of
a NS into a QS material can be ablated by neutrinos from the surface of the
star. Not only neutron-rich nuclei, but also more exotic material, such as
hypernuclei or deconfined quarks, could be ejected into the atmosphere. In the
NS atmosphere, atoms like H, He, and C should exist, and attempts to model the
NS thermal emission taking into account their presence, with spectra modified
by the extreme magnetic fields, have been done. However, exotic atoms, like
muonic hydrogen or the so-called Sigmium , could
also be present during the conversion process or in its immediate aftermath. At
present, analytical expressions of the wave functions and eigenvalues for these
atoms have been calculated only for H. In this work, we extend the existing
solutions and parametrizations to the exotic atoms and
, making some predictions on possible transitions. Their
detection in the spectra of NS would provide experimental evidence for the
existence of hyperons in the interior of these stars.Comment: 10 pages, 6 figures, proceedings of the "International Conference on
Exotic Atoms and Related Topics - EXA2017", Austrian Academy of Sciences,
Austria, September 11-15, 201
Near-Reference Air Quality Sensors Can Support Local Planning: A Performance Assessment in Milan, Italy
At present, 4.2 million deaths occur every year due to ambient air pollution, according to
the World Health Organization. In view of reducing such a figure, air quality monitoring and reliable
data are essential. Nevertheless, local authorities in urban environments, where pollution levels are
highest, often face a dilemma. On the one hand, the high costs of reference monitors make their largescale adoption prohibitive, while the easily scalable low-cost sensors often feature significantly lower
data quality and lack of calibration. Near reference monitors have been voiced as a promising solution,
as they exhibit limited costs, though specific studies assessing their performance against reference
monitors are still lacking. This article provides an in-depth assessment of three near reference sensorsâ
stations performance, through their collocation with regional reference monitors from December 2021
onwards. Two sensors were positioned at high-traffic locations, while the third recorded background
pollution levels in Milan, Italy. The sensorsâ performance was quantified not only via the coefficient
of determination (R2) and the regression model, but also with the Mean Normalized Bias (MNB) and
median values. After a first measurement period, sensors were re-calibrated to also appraise their
behavioral change, generally exhibiting a performance increase. Results show high correlation for
all hourly-recorded pollutants, with peaks for Ozone (O3) (R2 = 0.94) and BC (R2 = 0.93). Although
location-specific, such results show an interesting potential for near reference sensors in support of
urban air quality planning
Recurrent exercise-induced acute renal failure in a young Pakistani man with severe renal hypouricemia and SLC2A9 compound heterozygosity.
BACKGROUND:
Familial renal hypouricemia (RHUC) is a hereditary disease characterized by hypouricemia, high renal fractional excretion of uric acid (FE-UA) and can be complicated by acute kidney failure and nephrolithiasis. Loss-of-function mutations in the SLC22A12 gene cause renal hypouricemia type 1 (RHUC1), whereas renal hypouricemia type 2 (RHUC2) is caused by mutations in the SLC2A9 gene.
CASE PRESENTATION:
We describe a 24-year-old Pakistani man who was admitted twice to our hospital for severe exercise-induced acute renal failure (EIARF), abdominal pain and fever; he had very low serum UA levels (0.2 mg/dl the first time and 0.09 mg/dl the second time) and high FE-UA (200% and 732% respectively), suggestive of RHUC. Mutational analyses of both urate transporters revealed a new compound heterozygosity for two distinct missense mutations in the SLC2A9 gene: p.Arg380Trp, already identified in heterozygosity, and p.Gly216Arg, previously found in homozygosity or compound heterozygosity in some RHUC2 patients. Compared with previously reported patients harbouring these mutations, our proband showed the highest FE-UA levels, suggesting that the combination of p.Arg380Trp and p.Gly216Arg mutations most severely affects the renal handling of UA.
CONCLUSIONS:
The clinical and molecular findings from this patient and a review of the literature provide new insights into the genotype-phenotype correlation of this disorder, supporting the evidence of an autosomal recessive inheritance pattern for RHUC2. Further investigations into the functional properties of GLUT9, URAT1 and other urate transporters are required to assess their potential research and clinical implications
Arterial tortuosity syndrome in two Italian paediatric patients
<p>Abstract</p> <p>Background</p> <p>Arterial tortuosity syndrome (ATS) (OMIM #208050) is a rare autosomal recessive connective tissue disorder characterized by tortuosity and elongation of the large and medium-sized arteries, propensity to aneurysms formation, vascular dissection, and pulmonary arteries stenosis. ATS is caused by mutations in <it>SLC2A10 </it>gene, encoding for the facilitative glucose transporter 10 (GLUT10). So far, 17 <it>SLC2A10 </it>mutations have been reported in 32 families, two of which were Italian with a total of five patients. Here we present the clinical and molecular characterization of two novel Italian paediatric ATS patients.</p> <p>Methods</p> <p>The exons and intronic flanking regions of <it>SLC2A10 </it>gene were amplified and direct sequencing was performed.</p> <p>Results</p> <p>In both patients, the involvement of major- and medium-sized arteries was characteristic; the nonvascular connective tissue manifestations were mild and not pathognomic of the disorder. Both patients, born from non-consanguineous parents, were heterozygous for two different <it>SLC2A10 </it>mutations, three of which were recurrent and one was novel (p.Arg231Trp). This mutation is localized at the endofacial loop between the transmembrane domains 6 and 7 of GLUT10.</p> <p>Conclusion</p> <p>Two novel ATS patients were characterized at clinical and molecular level. Overall, four ATS unrelated families are known in Italy so far. Though ATS clinical delineation improved in the last years, further works in the comprehension of disease presentation and complications onset, particularly in paediatric age, and on ATS molecular basis are needed to add new insights for diagnosis and prevention strategies for related complications.</p
A Neuromorphic Prosthesis to Restore Communication in Neuronal Networks
Recent advances in bioelectronics and neural engineering allowed the development of brain machine interfaces and neuroprostheses, capable of facilitating or recovering functionality in people with neurological disability. To realize energy-efficient and real-time capable devices, neuromorphic computing systems are envisaged as the core of next-generation systems for brain repair. We demonstrate here a real-time hardware neuromorphic prosthesis to restore bidirectional interactions between two neuronal populations, even when one is damaged or missing. We used in vitro modular cell cultures to mimic the mutual interaction between neuronal assemblies and created a focal lesion to functionally disconnect the two populations. Then, we employed our neuromorphic prosthesis for bidirectional bridging to artificially reconnect two disconnected neuronal modules and for hybrid bidirectional bridging to replace the activity of one module with a real-time hardware neuromorphic Spiking Neural Network. Our neuroprosthetic system opens avenues for the exploitation of neuromorphic-based devices in bioelectrical therapeutics for health care
We can work it out: an enactive look at cooperation
The past years have seen an increasing debate on cooperation and its unique human character. Philosophers and psychologists have proposed that cooperative activities are characterized by shared goals to which participants are committed through the ability to understand each otherâs intentions. Despite its popularity, some serious issues arise with this approach to cooperation. First, one may challenge the assumption that high-level mental processes are necessary for engaging in acting cooperatively. If they are, then how do agents that do not possess such ability (preverbal children, or children with autism who are often claimed to be mind-blind) engage in cooperative exchanges, as the evidence suggests? Secondly, to define cooperation as the result of two de-contextualized minds reading each otherâs intentions may fail to fully acknowledge the complexity of situated, interactional dynamics and the interplay of variables such as the participantsâ relational and personal history and experience. In this paper we challenge such accounts of cooperation, calling for an embodied approach that sees cooperation not only as an individual attitude toward the other, but also as a property of interaction processes. Taking an enactive perspective, we argue that cooperation is an intrinsic part of any interaction, and that there can be cooperative interaction before complex communicative abilities are achieved. The issue then is not whether one is able or not to read the otherâs intentions, but what it takes to participate in joint action. From this basic account, it should be possible to build up more complex forms of cooperation as needed. Addressing the study of cooperation in these terms may enhance our understanding of human social development, and foster our knowledge of different ways of engaging with others, as in the case of autism
Towards the genetic basis of cerebral venous thrombosis-the BEAST Consortium: a study protocol.
INTRODUCTION:
Cerebral venous thrombosis (CVT) is a rare cerebrovascular condition accounting for <1% of all stroke cases and mainly affects young adults. Its genetic aetiology is not clearly elucidated.
METHODS AND ANALYSIS:
To better understand the genetic basis of CVT, we have established an international biobank of CVT cases, Biorepository to Establish the Aetiology of Sinovenous Thrombosis (BEAST) which aims to recruit highly phenotyped cases initially of European descent and later from other populations. To date we have recruited 745 CVT cases from 12 research centres. As an initial step, the consortium plans to undertake a genome-wide association analysis of CVT using the Illumina Infinium HumanCoreExome BeadChip to assess the association and impact of common and low-frequency genetic variants on CVT risk by using a case-control study design. Replication will be performed to confirm putative findings. Furthermore, we aim to identify interactions of genetic variants with several environmental and comorbidity factors which will likely contribute to improve the understanding of the biological mechanisms underlying this complex disease.
ETHICS AND DISSEMINATION:
BEAST meets all ethical standards set by local institutional review boards for each of the participating sites. The research outcomes will be published in international peer-reviewed open-access journals with high impact and visibility. The results will be presented at national and international meetings to highlight the contributions into improving the understanding of the mechanisms underlying this uncommon but important disease. This international DNA repository will become an important resource for investigators in the field of haematological and vascular disorders
A PM10 chemically characterised nation-wide dataset for Italy. Geographical influence on urban air pollution and source apportionment
: Urban textures of the Italian cities are peculiarly shaped by the local geography generating similarities among cities placed in different regions but comparable topographical districts. This suggested the following scientific question: can such different topographies generate significant differences on the PM10 chemical composition at Italian urban sites that share similar geography despite being in different regions? To investigate whether such communalities can be found and are applicable at Country-scale, we propose here a novel methodological approach. A dataset comprising season-averages of PM10 mass concentration and chemical composition data was built, covering the decade 2005-2016 and referring to urban sites only (21 cities). Statistical analyses, estimation of missing data, identification of latent clusters and source apportionment modelling by Positive Matrix Factorization (PMF) were performed on this unique dataset. The first original result is the demonstration that a dataset with atypical time resolution can be successfully exploited as an input matrix for PMF obtaining Country-scale representative chemical profiles, whose physical consistency has been assessed by different tests of modelling performance. Secondly, this dataset can be considered a reference repository of season averages of chemical species over the Italian territory and the chemical profiles obtained by PMF for urban Italian agglomerations could contribute to emission repositories. These findings indicate that our approach is powerful, and it could be further employed with datasets typically available in the air pollution monitoring networks
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