Effective algorithm for building and solving linear systems

Several mesh-based techniques in computer graphics such as shape deformation, mesh editing, animation and simulation, build and solve linear systems. The most common method to build a linear system consists in traversing the topology (connectivity) of the mesh, producing in general a representation of the set of equations in form of a sparse matrix. Similarly, the solution of the system is achieved, by means of iterating over the set of equations in the default sequence of the vertices (unknowns). This paper presents a new algorithm, which optimizes the build of the linear system and its storage, and which allows the iteration over the set of equations in any arbitrary order. Additionally, our algorithm enables rapid modifications to the linear system, avoiding a complete rebuild

Measurement error as an explanation for the alcohol harm paradox : analysis of eight cohort studies

Background: Despite reporting lower levels of alcohol consumption, people with lower socio-economic status (SES) experience greater alcohol-related harm. Whether differential biases in the measurement of alcohol use could explain this apparent paradox is unknown. Using alcohol biomarkers to account for measurement error, we examined whether differential exposure to alcohol could explain the socio-economic differences in alcohol mortality. Methods: Participants from eight representative health surveys (n = 52 164, mean age 47.7 years) were linked to mortality data and followed up until December 2016. The primary outcome was alcohol-attributable mortality. We used income and education as proxies for SES. Exposures include self-reported alcohol use and four alcohol biomarkers [serum gamma-glutamyl transferase (available in all surveys), carbohydrate-deficient transferrin, alanine aminotransferase and aspartate aminotransferase (available in subsamples)]. We used shared frailty Cox proportional hazards to account for survey heterogeneity. Results: During a mean follow-up of 20.3 years, totalling 1056 844 person-years, there were 828 alcohol-attributable deaths. Lower SES was associated with higher alcohol mortality despite reporting lower alcohol use. Alcohol biomarkers were associated with alcohol mortality and improved the predictive ability when used in conjunction with self-reported alcohol use. Alcohol biomarkers explained a very small fraction of the socio-economic differences in alcohol mortality, since hazard ratios either slightly attenuated (percent attenuation range 1.0-12.1%) or increased. Conclusions: Using alcohol biomarkers in addition to self-reported alcohol use did not explain the socio-economic differences in alcohol mortality. Differential bias in the measurement of alcohol use is not a likely explanation for the alcohol-harm paradox.Peer reviewe

Efficacy and safety of tocilizumab in giant cell arteritis:a single centre NHS experience using imaging (ultrasound and PET-CT) as a diagnostic and monitoring tool

Tocilizumab (TCZ), an IL-6 receptor blocker, is approved for relapsing, refractory giant cell arteritis (GCA). We report real-life clinical experience with TCZ in GCA including assessment of responses on imaging (ultrasound (US) and 18F-Fluorodeoxyglucose Positron Emission Tomography-computed Tomography ((18)FDG-PET-CT)) during the first year of treatment. We included 22 consecutive patients with GCA treated with TCZ where EULAR core data set on disease activity, quality of life (QoL) and treatment-related complications were collected. Pre-TCZ US and (18)FDG-PET/CT findings were available for 21 and 4 patients, respectively, where we determined the effect on US halo thickness, temporal and axillary artery Southend Halo Score and Total Vascular Score on (18)FDG-PET-CT. The 22 patients with GCA (10 cranial, 10 large vessel, 2 both) had a median disease duration of 58.5 (range, 1-370) weeks prior to initiation of TCZ. Half had used prior conventional synthetic disease-modifying antirheumatic drug (csDMARDs). TCZ was initiated for refractory (50%), ischaemic (36%) or relapsing (14%) disease. Median follow-up was 43 (12-52) weeks. TCZ was discontinued due to serious adverse events (SAEs) in two patients. On treatment with TCZ, 4 discontinued prednisolone, 11 required doses = 5 mg daily. QoL improved by 50%. Total US halo thickness decreased in 38 arterial segments, median temporal artery Halo Score decreased from 11 to 0, axillary artery Halo Score remained stable. Median Total Vascular Score on FDG-PET/CT reduced from 11.5 to 6.5. In our experience, TCZ showed an excellent response with acceptable safety in GCA, with improvement on US and FDG-PET/CT imaging

Rapid, experience-dependent translation of neurogranin enables memory encoding

Experience induces de novo protein synthesis in the brain and protein synthesis is required for long-term memory. It is important to define the critical temporal window of protein synthesis and identify newly synthesized proteins required for memory formation. Using a behavioral paradigm that temporally separates the contextual exposure from the association with fear, we found that protein synthesis during the transient window of context exposure is required for contextual memory formation. Among an array of putative activity-dependent translational neuronal targets tested, we identified one candidate, a schizophrenia-associated candidate mRNA, neurogranin (Ng, encoded by the Nrgn gene) responding to novel-context exposure. The Ng mRNA was recruited to the actively translating mRNA pool upon novel-context exposure, and its protein levels were rapidly increased in the hippocampus. By specifically blocking activity-dependent translation of Ng using virus-mediated molecular perturbation, we show that experience-dependent translation of Ng in the hippocampus is required for contextual memory formation. We further interrogated the molecular mechanism underlying the experience-dependent translation of Ng, and found that fragile-X mental retardation protein (FMRP) interacts with the 3′UTR of the Nrgn mRNA and is required for activity-dependent translation of Ng in the synaptic compartment and contextual memory formation. Our results reveal that FMRP-mediated, experience-dependent, rapid enhancement of Ng translation in the hippocampus during the memory acquisition enables durable context memory encoding. Keywords: hippocampus; contextual memory; dentate gyrus; ASD; schizophreni

Effectiveness of a Gamification Strategy to Prevent Childhood Obesity in Schools : A Cluster Controlled Trial

Objective The aim of this study was to examine the effectiveness of a school-based gamification strategy to prevent childhood obesity. Methods Schools were randomized in Santiago, Chile, between March and May 2018 to control or to receive a nutrition and physical activity intervention using a gamification strategy (i.e., the use of points, levels, and rewards) to achieve healthy challenges. The intervention was delivered for 7 months and participants were assessed at 4 and 7 months. Primary outcomes were mean difference in BMI z score and waist circumference (WC) between trial arms at 7 months. Secondary outcomes were mean difference in BMI and systolic and diastolic blood pressure between trial arms at 7 months. Results A total of 24 schools (5 controls) and 2,197 students (653 controls) were analyzed. Mean BMI z score was lower in the intervention arm compared with control (adjusted mean difference -0.133, 95% CI: -0.25 to -0.01), whereas no evidence of reduction in WC was found. Mean BMI and systolic blood pressure were lower in the intervention arm compared with control. No evidence of reduction in diastolic blood pressure was found. Conclusions The multicomponent intervention was effective in preventing obesity but not in reducing WC. Gamification is a potentially powerful tool to increase the effectiveness of school-based interventions to prevent obesity.Peer reviewe

Structure of \u3ci\u3eClostridium difficile\u3c/i\u3e PilJ Exhibits Unprecedented Divergence from Known Type IV Pilins

Type IV pili are produced by many pathogenic Gram-negative bacteria and are important for processes as diverse as twitching motility, cellular adhesion, and colonization. Recently, there has been an increased appreciation of the ability of Gram-positive species, including Clostridium difficile, to produce Type IV pili. Here we report the first three-dimensional structure of a Grampositive Type IV pilin, PilJ, demonstrate its incorporation into Type IV pili, and offer insights into how the Type IV pili of C. difficile may assemble and function. PilJ has several unique structural features, including a dual-pilin fold and the incorporation of a structural zinc ion. We show that PilJ is incorporated into Type IV pili in C. difficile and present a model in which the incorporation of PilJ into pili exposes the C-terminal domain of PilJ to create a novel interaction surface

Knowledge, Attitudes, and Practices Regarding COVID-19 Among Healthcare Workers in Venezuela:An Online Cross-Sectional Survey

Background: The deterioration of Venezuela's health system in recent years undoubtedly contributes to an increased impact of the COVID-19 pandemic. Understanding healthcare workers' (HCWs) knowledge, attitudes, and practices (KAPs) toward COVID-19 in the early stages of the pandemic could inform their medical training and improve their preparedness. Methods: A online national cross-sectional survey was conducted between May 26th and May 30th, 2020, to assess KAPs among HCWs in Venezuela. Results: A total of 1,441 HCWs from all 24 regions of the country responded to the survey. The mean age of the HCWs was 44 (SD [standard deviation] 14) years; most were women (66.4%). Most HCWs were specialized doctors (48%), followed by nurses (13%) and resident doctors (12.3%). The majority of HCWs had good knowledge (76.3%), obtained information mainly from scientific literature (85.4%); had negative attitudes (53.6%), felt uncomfortable with their work during the current pandemic (59.8%); and reported appropriate practices (76.9%). However, participation in COVID-19 related training was absent in more than half of the HCWs. Positive attitudes were significantly more frequent in frontline workers than in non-frontline workers (p = 0.001). Bioanalysts, students, and doctors were more likely to have good knowledge; participating in training was a predictor for positive attitudes and older age was an appropriate practice predictor. Conclusions: HCWs, knowledge in Venezuela could be improved by strengthening education and training programs. Strategies should focus on reducing fear and improving attitudes toward the care of COVID-19 patients, as well as the promotion of preventive practices

Tecnologías del hidrógeno

El interés por las tecnologías del hidrógeno ha crecido en los últimos años, principalmente porque una economía basada en el hidrógeno puede dar respuesta a los grandes desafíos de la economía global del futuro: seguridad energética y cambio climático. Aprovechando este impulso, cada vez son más los países que están implementando un número creciente de políticas en favor del hidrógeno. Prueba de ello es la Estrategia Europea del Hidrógeno que establece al hidrógeno como un elemento esencial en| la descarbonización total del actual sistema energético para alcanzar el compromiso de la UE con la neutralidad de carbono en 2050. No obstante, el desarrollo exitoso de las tecnologías del hidrógeno requiere que todos los actores, incluidos los sectores público y privado, aumenten sus esfuerzos para acelerar su despliegue y hacer que su implantación a gran escala resulte competitiva. Los grupos de investigación que forman parte del área de trabajo de tecnologías del hidrógeno, dentro de la Plataforma Temática Interdisciplinar PTI Mobility 2030 del CSIC, trabajan en este sentido, desarrollando su labor en áreas tan diversas como la generación, el almacenamiento, la distribución y los usos del hidrógeno. The interest in hydrogen technologies has grown in recent years, mainly because an economy based on hydrogen can help to solve important challenges related to the global economy of the future: energy security and climate change. Taking advantage of this momentum, more and more countries are implementing a growing number of policies related to hydrogen. Indeed, the European Hydrogen Strategy establishes hydrogen as essential drivers for the total decarbonization of the current energy system in order to achieve the Ells commitment related to carbon neutrality by 2050. However, the successful development of the hydrogen technologies requires the collaboration of the public and private sectors to accelerate its deployment and make more competitive its implementation at large-scale. The research groups that take part of the line of work dedicated to hydrogen technologies, within the CSIC Interdisciplinary Thematic Platform PTI Mobility 2030, work in this regard, developing their investigations in several important areas related to the hydrogen technologies such as hydrogen generation, storage, distribution and uses