89 research outputs found

    Supervised Classification with Matrix Sketching

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    Matrix sketching is a recently developed data compression technique. An input matrix A is efficiently approximated with a smaller matrix B, so that B preserves most of the properties of A up to some guaranteed approximation ratio. In so doing numerical operations on big data sets become faster. Sketching algorithms generally use random projections to compress the original dataset and this stochastic generation process makes them amenable to statistical analysis. The statistical properties of sketched regression algorithms have been widely studied previously. We study the performances of sketching algorithms in the supervised classification context, both in terms of misclassification rate and of boundary approximation, as the degree of sketching increases. We also address, through sketching, the issue of unbalanced classes, which hampers most of the common classification methods

    IL RILANCIO DELLA TRATTA COSENZA-CATANZARO DELLE FERROVIE DELLA CALABRIA COME CATALIZZATORE TERRITORIALE E METROPOLITANO

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    The modernization of a railway line is always an important project, but it assumes a strategic role if it is developed in a complex territory such as the northern district of Calabria. The technological upgrade of the Cosenza-Catanzaro railway line is the framework of a new process that aims to create an urban polycentric structure.This infrastructure, in fact, is the symbol of a collective rebirth, able to activate metropolitan flows into the whole area. The hinterland and the head-cities are strengthen by the inclusion in an implicit metropolitan area, capable of preserving their traditions and their cultures.DOI: http://dx.medra.org/10.19254/LaborEst.14.1

    Comparison of different microbiological procedures for the diagnosis of Pneumocystis jirovecii pneumonia on bronchoalveolar-lavage fluid

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    Background: The current diagnostic gold standard for Pneumocystis jirovecii is represented by microscopic visualization of the fungus from clinical respiratory samples, as bronchoalveolar-lavage fluid, defining "proven" P. jirovecii pneumonia, whereas qPCR allows defining "probable" diagnosis, as it is unable to discriminate infection from colonization. However, molecular methods, such as end-point PCR and qPCR, are faster, easier to perform and interpret, thus allowing the laboratory to give back the clinician useful microbiological data in a shorter time. The present study aims at comparing microscopy with molecular assays and beta-D-glucan diagnostic performance on bronchoalveolar-lavage fluids from patients with suspected Pneumocystis jirovecii pneumonia. Bronchoalveolar-lavage fluid from eighteen high-risk and four negative control subjects underwent Grocott-Gomori's methenamine silver-staining, end-point PCR, RT-PCR, and beta-D-glucan assay.Results: All the microscopically positive bronchoalveolar-lavage samples (50%) also resulted positive by end-point and real time PCR and all, but two, resulted positive also by beta-D-glucan quantification. End-point PCR and RT-PCR detected 10 (55%) and 11 (61%) out of the 18 samples, respectively, thus showing an enhanced sensitivity in comparison to microscopy. All RT-PCR with a Ct <27 were confirmed microscopically, whereas samples with a Ct >= 27 were not.Conclusions: Our work highlights the need of reshaping and redefining the role of molecular diagnostics in a peculiar clinical setting, like P. jirovecii infection, which is a rare but also severe and rapidly progressive clinical condition affecting immunocompromised hosts that would largely benefit from a faster diagnosis. Strictly selected patients, according to the inclusion criteria, resulting negative by molecular methods could be ruled out for P. jirovecii pneumonia

    Irreversible Work and Inner Friction in Quantum Thermodynamic Processes

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    We discuss the thermodynamics of closed quantum systems driven out of equilibrium by a change in a control parameter and undergoing a unitary process. We compare the work actually done on the system with the one that would be performed along ideal adiabatic and isothermal transformations. The comparison with the latter leads to the introduction of irreversible work, while that with the former leads to the introduction of inner friction. We show that these two quantities can be treated on an equal footing, as both can be linked with the heat exchanged in thermalization processes and both can be expressed as relative entropies. Furthermore, we show that a specific fluctuation relation for the entropy production associated with the inner friction exists, which allows the inner friction to be written in terms of its cumulants.All the authors acknowledge support from COST MP1209 Action. F. P., G. F., and N. L. G. acknowledge insightful discussions with Michele Campisi, John Goold, and Mauro Paternostro. T. J. G. A. is supported by the European Commission, the European Social Fund, and the Region Calabria through the program POR Calabria FSE 2007-2013-Asse IV Capitale Umano-Obiettivo Operativo M2. F. G. and R. Z. acknowledge MINECO, CSIC, the EU commission, UIB and FEDER funding under Grants FIS2011-23526 (TIQS), postdoctoral JAE program (ESF) and Invited professors program.Peer reviewe

    Prognostic significance of diabetes and stress hyperglycemia in acute stroke patients

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    Background Hyperglycemic non-diabetic stroke patients have a worse prognosis than both normoglycemic and diabetic patients. Aim of this study was to assess whether hyperglycemia is an aggravating factor or just an epiphenomenon of most severe strokes. Methods In this retrospective study, 1219 ischemic or hemorrhagic stroke patients (73.7 +/- 13.1 years) were divided into 4 groups: 0 = non-hyperglycemic non-diabetic, 1 = hyperglycemic non-diabetic, 2 = non-hyperglycemic diabetic and 3 = hyperglycemic diabetic. Hyperglycemia was defined as fasting blood glucose >= 126 mg/dl (>= 7 mmol/l) measured the morning after admission, while the diagnosis of diabetes was based on a history of diabetes mellitus or on a glycated hemoglobin >= 6.5% (>= 48 mmol/mol), independently of blood glucose levels. All diabetic patients, except 3, had Type 2 diabetes. The 4 groups were compared according to clinical history, stroke severity indicators, acute phase markers and main short term stroke outcomes (modified Rankin scale >= 3, death, cerebral edema, hemorrhagic transformation of ischemic lesions, fever, oxygen administration, pneumonia, sepsis, urinary infection and heart failure). Results Group 1 patients had more severe strokes, with larger cerebral lesions and higher inflammatory markers, compared to the other groups. They also had a high prevalence of atrial fibrillation, prediabetes, previous stroke and previous arterial revascularizations. In this group, the highest frequencies of cerebral edema, hemorrhagic transformation, pneumonia and oxygen administration were obtained. The prevalence of dependency at discharge and in-hospital mortality were equally high in Group 1 and Group 3. However, in multivariate analyses including stroke severity, cerebral lesion diameter, leukocytes and C-reactive protein, Group 1 was only independently associated with hemorrhagic transformation (OR 2.01, 95% CI 0.99-4.07), while Group 3 was independently associated with mortality (OR 2.19, 95% CI 1.32-3.64) and disability (OR 1.70, 95% CI 1.01-2.88). Conclusions Hyperglycemic non-diabetic stroke patients had a worse prognosis than non-hyperglycemic or diabetic patients, but this group was not independently associated with mortality or disability when size, severity and inflammatory component of the stroke were accounted for

    Sustentabilidad y tecnología. Herramientas para la gestión segura y eficiente del hábitat

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    Por décadas permeó una visión de la tecnología como una de las principales fuentes del ataque al medio ambiente y de su degradación. Hoy se le considera como un aliado para combatir los efectos negativos de la perenne negligencia ecológica humana. El uso de la tecnología para la implementación de estrategias innovadoras y eficaces en favor del medio ambiente, un hábitat seguro y sustentable, se abordó en el Congreso Internacional sobre Sustentabilidad en los Hábitats, realizado en 2016. De este encuentro entre estudiantes, especialistas, autoridades y organizaciones civiles de América Latina, Asia y Europa emana este libro, que incluye dos ejes de relevancia global: los retos en el manejo sustentable de los recursos naturales y el uso de tecnologías para la edificación sustentable. En el primero se atienden desde los riesgos asociados al crecimiento demográfico desproporcionado hasta acciones de carácter remedial para la contaminación; mientras que en el segundo se aborda el desarrollo de tecnología e infraestructura para mejorar el hábitat urbano, así como procesos donde alumnos y profesores confeccionan soluciones para la sustentabilidad energética. En su conjunto, es una obra de consulta que busca ser un detonador para generar nuevas líneas de trabajo, repensar las soluciones y dialogar con lectores interesados en la construcción de un mundo mejor.Consejo Estatal de Ciencia y Tecnología de Jalisc

    An explainable model of host genetic interactions linked to COVID-19 severity

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    We employed a multifaceted computational strategy to identify the genetic factors contributing to increased risk of severe COVID-19 infection from a Whole Exome Sequencing (WES) dataset of a cohort of 2000 Italian patients. We coupled a stratified k-fold screening, to rank variants more associated with severity, with the training of multiple supervised classifiers, to predict severity based on screened features. Feature importance analysis from tree-based models allowed us to identify 16 variants with the highest support which, together with age and gender covariates, were found to be most predictive of COVID-19 severity. When tested on a follow-up cohort, our ensemble of models predicted severity with high accuracy (ACC = 81.88%; AUCROC = 96%; MCC = 61.55%). Our model recapitulated a vast literature of emerging molecular mechanisms and genetic factors linked to COVID-19 response and extends previous landmark Genome-Wide Association Studies (GWAS). It revealed a network of interplaying genetic signatures converging on established immune system and inflammatory processes linked to viral infection response. It also identified additional processes cross-talking with immune pathways, such as GPCR signaling, which might offer additional opportunities for therapeutic intervention and patient stratification. Publicly available PheWAS datasets revealed that several variants were significantly associated with phenotypic traits such as "Respiratory or thoracic disease", supporting their link with COVID-19 severity outcome.A multifaceted computational strategy identifies 16 genetic variants contributing to increased risk of severe COVID-19 infection from a Whole Exome Sequencing dataset of a cohort of Italian patients

    Carriers of ADAMTS13 Rare Variants Are at High Risk of Life-Threatening COVID-19

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    Thrombosis of small and large vessels is reported as a key player in COVID-19 severity. However, host genetic determinants of this susceptibility are still unclear. Congenital Thrombotic Thrombocytopenic Purpura is a severe autosomal recessive disorder characterized by uncleaved ultra-large vWF and thrombotic microangiopathy, frequently triggered by infections. Carriers are reported to be asymptomatic. Exome analysis of about 3000 SARS-CoV-2 infected subjects of different severities, belonging to the GEN-COVID cohort, revealed the specific role of vWF cleaving enzyme ADAMTS13 (A disintegrin-like and metalloprotease with thrombospondin type 1 motif, 13). We report here that ultra-rare variants in a heterozygous state lead to a rare form of COVID-19 characterized by hyper-inflammation signs, which segregates in families as an autosomal dominant disorder conditioned by SARS-CoV-2 infection, sex, and age. This has clinical relevance due to the availability of drugs such as Caplacizumab, which inhibits vWF-platelet interaction, and Crizanlizumab, which, by inhibiting P-selectin binding to its ligands, prevents leukocyte recruitment and platelet aggregation at the site of vascular damage

    Gain- and Loss-of-Function CFTR Alleles Are Associated with COVID-19 Clinical Outcomes

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    Carriers of single pathogenic variants of the CFTR (cystic fibrosis transmembrane conductance regulator) gene have a higher risk of severe COVID-19 and 14-day death. The machine learning post-Mendelian model pinpointed CFTR as a bidirectional modulator of COVID-19 outcomes. Here, we demonstrate that the rare complex allele [G576V;R668C] is associated with a milder disease via a gain-of-function mechanism. Conversely, CFTR ultra-rare alleles with reduced function are associated with disease severity either alone (dominant disorder) or with another hypomorphic allele in the second chromosome (recessive disorder) with a global residual CFTR activity between 50 to 91%. Furthermore, we characterized novel CFTR complex alleles, including [A238V;F508del], [R74W;D1270N;V201M], [I1027T;F508del], [I506V;D1168G], and simple alleles, including R347C, F1052V, Y625N, I328V, K68E, A309D, A252T, G542*, V562I, R1066H, I506V, I807M, which lead to a reduced CFTR function and thus, to more severe COVID-19. In conclusion, CFTR genetic analysis is an important tool in identifying patients at risk of severe COVID-19
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