89 research outputs found
Fast direct solution of method of moments applied to multiscale problems
In a recent publication [1], we proposed a new convergence criterion for the Adapted Cross
Approximation (ACA) algorithm, based on random sampling of the matrix that represents the
residual error at each step of the algorithm. We presented some practical examples involving
RCS computations of perfectly conducting benchmark targets exhibiting multiscale features,
meaning that the mesh-size of the discrete model of the target is highly variable. These
examples demonstrated a considerable improvement in the accuracy of the RCS result without
appreciable loss of efficiency. In the presented examples, the solution was obtained by an
iterative solver applied to an ACA-compressed Method of Moments impedance matrix. In this
paper we apply the new method from [1] to the direct (non-iterative) solution of the MoM
matrix. The results demonstrate that in this case, the advantage of the new method is far more
important. Compared to ordinary ACA, the same accuracy is obtained in less than a quarter of
the computation time
Enumerating super edge-magic labelings for the union of non-isomorphic graphs
A super edge-magic labeling of a graph G=(V,E) of order p and size q is a bijection f:V ∪E→{i}p+qi=1 such that: (1) f(u)+f(uv)+f(v)=k for all uv∈E; and (2) f(V )={i}pi=1. Furthermore, when G is a linear forest, the super edge-magic labeling of G is called strong if it has the extra property that if uv∈E(G) , u′,v′ ∈V (G) and dG (u,u′ )=dG (v,v′ )<+∞, then f(u)+f(v)=f(u′ )+f(v′ ). In this paper we introduce the concept of strong super edge-magic labeling of a graph G with respect to a linear forest F, and we study the super edge-magicness of an odd union of nonnecessarily isomorphic acyclic graphs. Furthermore, we find exponential lower bounds for the number of super edge-magic labelings of these unions. The case when G is not acyclic will be also considered.Preprin
Needle tract seeding and malignant transformation of hepatocellular adenoma into well-differentiated hepatocellular carcinoma in a dog
Altres ajuts: acords transformatius de la UABAn 11-year-old neutered female Golden Retriever was referred for investigation of marked increases in liver enzyme activities. Abdominal ultrasound revealed a large pedunculated liver mass. Diagnosis of hepatocellular adenoma (HCA) was made when the mass was excised after a first unsuccessful attempt through ultrasound-guided core-needle biopsy. One and a half years after presentation, a nodule embedded between muscles of the abdominal wall appeared. The mass was first diagnosed as a well-differentiated hepatocellular carcinoma (HCC) through cytologic examination, which was later confirmed with histopathology. Ki 67 immunostaining of the abdominal wall nodule showed an increased immunoreactivity compared with the liver mass. Therefore, the present case documents the first needle-tract seeding of a hepatocellular epithelial tumor with possible malignant transformation of HCA into a well-differentiated HCC in a dog
Megalencephalic leukoencephalopathy with subcortical cysts protein 1 regulates glial surface localization of GLIALCAM from fish to humans
Megalencephalic leukoencephalopathy with subcortical cysts (MLC) is a leukodystrophy characterized by myelin vacuolization and caused by mutations in MLC1 or GLIALCAM. Patients with recessive mutations in either MLC1 or GLIALCAM show the same clinical phenotype. It has been shown that GLIALCAM is necessary for the correct targeting of MLC1 to the membrane at cell junctions, but its own localization was independent of MLC1 in vitro. However, recent studies in Mlc1−/− mice have shown that GlialCAM is mislocalized in glial cells. In order to investigate whether the relationship between Mlc1 and GlialCAM is species-specific, we first identified MLC-related genes in zebrafish and generated an mlc1−/− zebrafish. We have characterized mlc1−/− zebrafish both functionally and histologically and compared the phenotype with that of the Mlc1−/− mice. In mlc1−/− zebrafish, as in Mlc1−/− mice, Glialcam is mislocalized. Re-examination of a brain biopsy from an MLC patient indicates that GLIALCAM is also mislocalized in Bergmann glia in the cerebellum. In vitro, impaired localization of GlialCAM was observed in astrocyte cultures from Mlc1−/− mouse only in the presence of elevated potassium levels, which mimics neuronal activity. In summary, here we demonstrate an evolutionary conserved role for MLC1 in regulating glial surface levels of GLIALCAM, and this interrelationship explains why patients with mutations in either gene (MLC1 or GLIALCAM) share the same clinical phenotyp
Ceres Scales Ground Validation Campaigns for Gerb. Assessment of the Valencia Anchor Station Capabilities
Proceedings del 3rd MSG RAO Workshop, celebrado el 15 de junio de 2006 en Helsinki, Finlandia.The Valencia Anchor Station (VAS) was set up by the
University of Valencia at the natural region of UtielRequena Plateau in 2001. The plateau is a large and
reasonably homogeneous area suitable for validation of
low spatial resolution satellite data and products such
as GERB's. In the framework of the EUMETSAT/ESA
MSG-RAO Project no. 138 GIST Proposal for
Calibration/Validation of SEVIRI and GERB, and of
the Spanish Research Programme on Space Project
SCALES (SEVIRI & GERB Cal/Val Area for Largescale Field ExperimentS), three GERB ground
validation campaigns have so far been carried out at the
VAS under different land surface conditions. CERES
instruments onboard NASA EOS Aqua and Terra
satellites, operating in PAPS (Programmable Azimuth
Plane Scanning) mode, have generously provided
additional SW and LW radiance measurements to
support validation efforts. These have shown to be
most valuable as intermediate validation step between
ground measurements and the large GERB pixel size
Integrated GWAS and Gene Expression Suggest ORM1 as a Potential Regulator of Plasma Levels of Cell-Free DNA and Thrombosis Risk
Plasma cell-free DNA (cfDNA) is a surrogate marker of neutrophil extracellular traps (NETs) that contribute to immunothrombosis. There is growing interest about the mechanisms underlying NET formation and elevated cfDNA, but little is known about the factors involved. We aimed to identify genes involved in the regulation of cfDNA levels using data from the Genetic Analysis of Idiopathic Thrombophilia (GAIT-2) Project. Imputed genotypes, whole blood RNA-Seq data, and plasma cfDNA quantification were available for 935 of the GAIT-2 participants from 35 families with idiopathic thrombophilia. We performed heritability and GWAS analysis for cfDNA. The heritability of cfDNA was 0.26 ( p = 3.7 × 10 (−6) ), while the GWAS identified a significant association (rs1687391, p = 3.55 × 10 (−10) ) near the ORM1 gene, on chromosome 9. An eQTL (expression quantitative trait loci) analysis revealed a significant association between the lead GWAS variant and the expression of ORM1 in whole blood ( p = 6.14 × 10 (−9) ). Additionally, ORM1 expression correlated with levels of cfDNA ( p = 4.38 × 10 (−4) ). Finally, genetic correlation analysis between cfDNA and thrombosis identified a suggestive association ( ρ (g) = 0.43, p = 0.089). All in all, we show evidence of the role of ORM1 in regulating cfDNA levels in plasma, which might contribute to the susceptibility to thrombosis through mechanisms of immunothrombosis
Dissimilar Impact of a Mediterranean Diet and Physical Activity on Anthropometric Indices: A Cross-Sectional Study from the ILERVAS Project
There is a close relationship between lifestyle behaviors and excess adiposity. Although body mass index (BMI) is the most used approach to estimate excess weight, other anthropometric indices have been developed to measure total body and abdominal adiposity. However, little is known about the impact of physical activity and adherence to a Mediterranean diet on these indices. Here we report the results of a cross-sectional study with 6672 middle-aged subjects with low to moderate cardiovascular risk from the Ilerda Vascular (ILERVAS) project. The participants' adherence to physical activity (International Physical Activity Questionnaire short form) and MedDiet (Mediterranean Diet Adherence Screener) was evaluated. Measures of total adiposity (BMI, Clínica Universidad de Navarra-Body Adiposity Estimator (CUN-BAE), and Deurenberg's formula), central adiposity (waist and neck circumferences, conicity index, waist to height ratio, Bonora's equation, A body adiposity index, and body roundness index), and lean body mass (Hume formula) were assessed. Irrespective of sex, lower indices of physical activity were associated with higher values of total body fat and central adiposity. This result was constant regardless of the indices used to estimate adiposity. However, the association between MedDiet and obesity indices was much less marked and more dependent on sex than that observed for physical activity. Lean body mass was influenced by neither physical activity nor MedDiet adherence. No joint effect between physical activity and MedDiet to lower estimated total or central adiposity indices was shown. In conclusion, physical activity is related to lower obesity indices in a large cohort of middle-aged subjects. MedDiet showed a slight impact on estimated anthropometric indices, with no joint effect when considering both lifestyle variables
Combination of Tocilizumab and Steroids to Improve Mortality in Patients with Severe COVID-19 Infection : A Spanish, Multicenter, Cohort Study
We aimed to determine the impact of tocilizumab use on severe COVID-19 (coronavirus disease 19) pneumonia mortality. We performed a multicentre retrospective cohort study in 18 tertiary hospitals in Spain from March to April 2020. Consecutive patients admitted with severe COVID-19 treated with tocilizumab were compared to patients not treated with tocilizumab, adjusting by inverse probability of the treatment weights (IPTW). Tocilizumab's effect in patients receiving steroids during the 48 h following inclusion was analysed. During the study period, 506 patients with severe COVID-19 fulfilled the inclusion criteria. Among them, 268 were treated with tocilizumab and 238 patients were not. Median time to tocilizumab treatment from onset of symptoms was 11 days [interquartile range (IQR) 8-14]. Global mortality was 23.7%. Mortality was lower in patients treated with tocilizumab than in controls: 16.8% versus 31.5%, hazard ratio (HR) 0.514 [95% confidence interval (95% CI) 0.355-0.744], p < 0.001; weighted HR 0.741 (95% CI 0.619-0.887), p = 0.001. Tocilizumab treatment reduced mortality by 14.7% relative to no tocilizumab treatment [relative risk reduction (RRR) 46.7%]. We calculated a number necessary to treat of 7. Among patients treated with steroids, mortality was lower in those treated with tocilizumab than in those treated with steroids alone [10.9% versus 40.2%, HR 0.511 (95% CI 0.352-0.741), p = 0.036; weighted HR 0.6 (95% CI 0.449-0.804), p < 0.001] (interaction p = 0.094). These results show that survival of patients with severe COVID-19 is higher in those treated with tocilizumab than in those not treated and that tocilizumab's effect adds to that of steroids administered to non-intubated patients with COVID-19 during the first 48 h of presenting with respiratory failure despite oxygen therapy. Randomised controlled studies are needed to confirm these results. European Union electronic Register of Post-Authorization Studies (EU PAS Register) identifier, EUPAS34415 The online version of this article (10.1007/s40121-020-00373-8) contains supplementary material, which is available to authorized users
Four-month incidence of suicidal thoughts and behaviors among healthcare workers after the first wave of the Spain COVID-19 pandemic
Healthcare workers (HCW) are at high risk for suicide, yet little is known about the onset of suicidal thoughts and behaviors (STB) in this important segment of the population in conjunction with the COVID-19 pandemic. We conducted a multicenter, prospective cohort study of Spanish HCW active during the COVID-9 pandemic. A total of n = 4809 HCW participated at baseline (May-September 2020; i.e., just after the first wave of the pandemic) and at a four-month follow-up assessment (October-December 2020) using web-based surveys. Logistic regression assessed the individual- and population-level associations of separate proximal (pandemic) risk factors with four-month STB incidence (i.e., 30-day STB among HCW negative for 30-day STB at baseline), each time adjusting for distal (pre-pandemic) factors. STB incidence was estimated at 4.2% (SE = 0.5; n = 1 suicide attempt). Adjusted for distal factors, proximal risk factors most strongly associated with STB incidence were various sources of interpersonal stress (scaled 0-4; odds ratio [OR] range = 1.23-1.57) followed by personal health-related stress and stress related to the health of loved ones (scaled 0-4; OR range 1.30-1.32), and the perceived lack of healthcare center preparedness (scaled 0-4; OR = 1.34). Population-attributable risk proportions for these proximal risk factors were in the range 45.3-57.6%. Other significant risk factors were financial stressors (OR range 1.26-1.81), isolation/quarantine due to COVID-19 (OR = 1.53) and having changed to a specific COVID-19 related work location (OR = 1.72). Among other interventions, our findings call for healthcare systems to implement adequate conflict communication and resolution strategies and to improve family-work balance embedded in organizational justice strategies.This work was supported by grants from the Instituto de Salud Carlos III (ISCIII)/Ministerio de Ciencia e Innovación/FEDER, Spain (Jordi Alonso, grant number COV20/00711); ISCIII-FEDER, Spain (Jordi Alonso, grant number PI17/00521); ISCIII-FSE, Spain: Sara Borrell and Miguel Servet grants (Philippe Mortier, grant number CD18/00049 and CP21/00078); Generalitat de Catalunya, Spain (2017SGR452); and PERIS, Departament de Salut, Spain (Itxaso Alayo; SLT017/20/000009). Additional partial funding was received from the Gerencia Regional de Salud de Castilla y León (SACYL), Spain (José María Pelayo Terán, grant number GRS COVID 32/A/20).S
Mental impact of Covid-19 among Spanish healthcare workers. A large longitudinal survey
Aims: Longitudinal data on the mental health impact of the coronavirus disease 2019 (Covid-19) pandemic in healthcare workers is limited. We estimated prevalence, incidence and persistence of probable mental disorders in a cohort of Spanish healthcare workers (Covid-19 waves 1 and 2) -and identified associated risk factors. Methods: 8996 healthcare workers evaluated on 5 May-7 September 2020 (baseline) were invited to a second web-based survey (October-December 2020). Major depressive disorder (PHQ-8 ≥ 10), generalised anxiety disorder (GAD-7 ≥ 10), panic attacks, post-traumatic stress disorder (PCL-5 ≥ 7), and alcohol use disorder (CAGE-AID ≥ 2) were assessed. Distal (pre-pandemic) and proximal (pandemic) risk factors were included. We estimated the incidence of probable mental disorders (among those without disorders at baseline) and persistence (among those with disorders at baseline). Logistic regression of individual-level [odds ratios (OR)] and population-level (population attributable risk proportions) associations were estimated, adjusting by all distal risk factors, health care centre and time of baseline interview. Results: 4809 healthcare workers participated at four months follow-up (cooperation rate = 65.7%; mean = 120 days s.d. = 22 days from baseline assessment). Follow-up prevalence of any disorder was 41.5%, (v. 45.4% at baseline, p < 0.001); incidence, 19.7% (s.e. = 1.6) and persistence, 67.7% (s.e. = 2.3). Proximal factors showing significant bivariate-adjusted associations with incidence included: work-related factors [prioritising Covid-19 patients (OR = 1.62)], stress factors [personal health-related stress (OR = 1.61)], interpersonal stress (OR = 1.53) and financial factors [significant income loss (OR = 1.37)]. Risk factors associated with persistence were largely similar. Conclusions: Our study indicates that the prevalence of probable mental disorders among Spanish healthcare workers during the second wave of the Covid-19 pandemic was similarly high to that after the first wave. This was in good part due to the persistence of mental disorders detected at the baseline, but with a relevant incidence of about 1 in 5 of HCWs without mental disorders during the first wave of the Covid-19 pandemic. Health-related factors, work-related factors and interpersonal stress are important risks of persistence of mental disorders and of incidence of mental disorders. Adequately addressing these factors might have prevented a considerable amount of mental health impact of the pandemic among this vulnerable population. Addressing health-related stress, work-related factors and interpersonal stress might reduce the prevalence of these disorders substantially. Study registration number: NCT04556565.Instituto de Salud Carlos III/ Ministerio de Ciencia e Innovación/ FEDER (J. A., grant number COV20/00711); Project “PI17/00521”, funded by Instituto de Salud Carlos III (ISCIII) and co-funded by the European Union, PERIS, Health Dpt, Generaliat de Catalunya (I. A., grant number SLT017/20/000009); ISCIII-FSE+, Miguel Servet (P. M., grant number CP21/00078); ISCIII-FSE, Sara Borrell (P. M., grant number CD18/00049), Generalitat de Catalunya (2017SGR452). Additional partial funding was received from the Gerencia Regional de Salud de Castilla y León (SACYL) (J. M. P. T., grant number GRS COVID 32/A/20).S
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