76 research outputs found

    New Metrics for Learning Evaluation in Digital Education Platforms

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    Technology applied in education can provide great benefits and overcome challenges by facilitating access to learning objects anywhere and anytime. However, technology alone is not enough, since it requires suitable planning and learning methodologies. Using technology can be problematic, especially in determining whether learning has occurred or not. Futhermore, if learning has not occured, technology can make it difficult to determine how to mitigate this lack of learning. This paper presents a set of new metrics for measuring student's acquired understanding of a content in technology-based education platforms. Some metrics were taken from the literature "as is", some were modified slighty, while others were added. The hypothesis is that we should not only focus on traditional scoring, because it only counts the number of hits/errors and does not consider any other aspect of learning. We applied all metrics to an assessment conducted in a high school class in which we show specific cases, along with metrics, where very useful information can be obtained from by combining several metrics. We conclude that the proposed metrics are promising for measuring student's acquired understanding of a content, as well as for teachers to measure student's weaknesses.Comment: 12 pages, 6 figures, 12 table

    Production of fatty-acyl-glutamate biosurfactant by Bacillus subtilis on soybean co-products

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    Fatty-acyl-glutamate (FA-Glu), a surfactin variant has been successfully produced using a genetically modified strain of Bacillus subtilis grown on glucose. However, yields with soybean hulls (SBH) replacing glucose were lower. This work was undertaken to reduce the yield loss when using SBH as the carbon source and to evaluate two other soy by-products, namely fiber and skim from aqueous oil extraction as alternative carbon and nitrogen sources. Fermentation of soybean hulls, fibers and skim at various concentrations produced lower FA-Glu titers compared to S-7 medium. Neither increasing their amount nor supplementing with glucose increased the FA-Glu titer, suggesting the presence of an inhibitor in these feedstocks. By using a mixture of polysaccharide-degrading enzymes, over 65% of SBH solids were converted to soluble carbohydrates. FA-Glu titers obtained from SBH hydrolysates containing residual hull solids were still low; however, with the removal of the solids, cell growth improved and FA-Glu yield was 60% higher than with glucose. Thus, this low-cost material can be converted to a substrate for production of FA-Glu biosurfactant. Unmodified fiber and skim components of aqueous oil extraction were not beneficial

    TREM2 triggers microglial density and age‐related neuronal loss

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    The microglial triggering receptor expressed on myeloid cells 2 (TREM2) signals via the activatory membrane adaptor molecule TYROBP. Genetic variants or mutations of TREM2 or TYROBP have been linked to inflammatory neurodegenerative diseases associated with aging. The typical aging process goes along with microglial changes and mild neuronal loss, but the exact contribution of TREM2 is still unclear. Aged TREM2 knock‐out mice showed decreased age‐related neuronal loss in the substantia nigra and the hippocampus. Transcriptomic analysis of the brains of 24 months old TREM2 knock‐out mice revealed 211 differentially expressed genes mostly downregulated and associated with complement activation and oxidative stress response pathways. Consistently, 24 months old TREM2 knock‐out mice showed lower transcription of microglial (Aif1 and Tmem119), oxidative stress markers (Inos, Cyba, and Cybb) and complement components (C1qa, C1qb, C1qc, C3, C4b, Itgam, and Itgb2), decreased microglial numbers and expression of the microglial activation marker Cd68, as well as accumulation of oxidized lipids. Cultured microglia of TREM2 knock‐out mice showed reduced phagocytosis and oxidative burst. Thus, microglial TREM2 contributes to age‐related microglial changes, phagocytic oxidative burst, and loss of neurons with possible detrimental effects during physiological aging

    RBD-specific polyclonal F(ab´)2 fragments of equine antibodies in patients with moderate to severe COVID-19 disease: A randomized, multicenter, double-blind, placebo-controlled, adaptive phase 2/3 clinical trial

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    Background: passive immunotherapy is a therapeutic alternative for patients with COVID-19. Equine polyclonal antibodies (EpAbs) could represent a source of scalable neutralizing antibodies against SARS-CoV-2. Methods: we conducted a double-blind, randomized, placebo-controlled trial to assess efficacy and safety of EpAbs (INM005) in hospitalized adult patients with moderate and severe COVID-19 pneumonia in 19 hospitals of Argentina. Primary endpoint was improvement in at least two categories in WHO ordinal clinical scale at day 28 or hospital discharge (ClinicalTrials.gov number NCT04494984). Findings: between August 1st and October 26th, 2020, a total of 245 patients were enrolled. Enrolled patients were assigned to receive two blinded doses of INM005 (n = 118) or placebo (n = 123). Median age was 54 years old, 65 1% were male and 61% had moderate disease at baseline. Median time from symptoms onset to study treatment was 6 days (interquartile range 5 to 8). No statistically significant difference was noted between study groups on primary endpoint (risk difference [95% IC]: 5 28% [-3 95; 14 50]; p = 0 15). Rate of improvement in at least two categories was statistically significantly higher for INM005 at days 14 and 21 of follow-up. Time to improvement in two ordinal categories or hospital discharge was 14 2 (§ 0 7) days in the INM005 group and 16 3 (§ 0 7) days in the placebo group, hazard ratio 1 31 (95% CI 1 0 to 1 74). Subgroup analyses showed a beneficial effect of INM005 over severe patients and in those with negative baseline antibodies. Overall mortality was 6 9% the INM005 group and 11 4% in the placebo group (risk difference [95% IC]: 0 57 [0 24 to 1 37]). Adverse events of special interest were mild or moderate; no anaphylaxis was reported. Interpretation: Albeit not having reached the primary endpoint, we found clinical improvement of hospitalized patients with SARS-CoV-2 pneumonia, particularly those with severe disease.Fil: Lopardo, Gustavo. Municipalidad de Vicente Lopez (buenos Aires). Hospital Municipal Doctor Bernardo Houssay.; ArgentinaFil: Belloso, Waldo H.. Hospital Italiano; ArgentinaFil: Nannini, Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Colonna, Mariana. Inmunova; ArgentinaFil: Sanguineti, Santiago. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Inmunova; ArgentinaFil: Zylberman, Vanesa. Inmunova; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Muñoz, Luciana. Inmunova; ArgentinaFil: Dobarro, Martín. Sanatorio Sagrado Corazón; ArgentinaFil: Lebersztein, Gabriel. Sanatorio Sagrado Corazón; ArgentinaFil: Farina, Javier. Gobierno de la Provincia de Buenos Aires. Hospital de Alta Complejidad Cuenca Alta Doctor Nestor Carlos Kirchner.; ArgentinaFil: Vidiella, Gabriela. Sanatorio Agote. Dr. Luis Agote; ArgentinaFil: Bertetti, Anselmo. Sanatorio Guemes Sociedad Anonima.; ArgentinaFil: Crudo, Favio. Universidad Nacional de San Antonio de Areco; ArgentinaFil: Alzogaray, Maria Fernanda. Instituto Medico Platense.; ArgentinaFil: Barcelona, Laura. Municipalidad de Vicente Lopez (buenos Aires). Hospital Municipal Doctor Bernardo Houssay.; ArgentinaFil: Teijeiro, Ricardo. Gobierno de la Ciudad Autónoma de Buenos Aires. Hospital General de Agudos Doctor Ignacio Pirovano; ArgentinaFil: Lambert, Sandra. Provincia de Buenos Aires. Ministerio de Salud. Hospital Alta Complejidad en Red El Cruce Dr. Néstor Carlos Kirchner Samic; ArgentinaFil: Scublinsky, Darío. Clinica Zabala.; ArgentinaFil: Iacono, Marisa. Provincia del Neuquen. Hospital Provincial Neuquen "dr. E. Castro Rendon"; ArgentinaFil: Stanek, Vanina. Hospital Italiano; ArgentinaFil: Solari, Rubén. Gobierno de la Ciudad de Buenos Aires. Hospital de Infecciosas "Dr. Francisco Javier Muñiz"; ArgentinaFil: Cruz, Pablo. No especifíca;Fil: Casas, Marcelo Martín. Clinica Adventista Belgrano; ArgentinaFil: Abusamra, Lorena. Hospital Municipal Dr. Diego Thompson; ArgentinaFil: Luciardi, Héctor Lucas. Provincia de Tucuman. Ministerio de Salud. Sistema Provincial de Salud. Hosp. Centro de Salud "zenon Santillan"; ArgentinaFil: Cremona, Alberto. Hospital Italiano de La Plata; ArgentinaFil: Caruso, Diego. Hospital Español; ArgentinaFil: de Miguel, Bernardo. No especifíca;Fil: Perez Lloret, Santiago. Pontificia Universidad Católica Argentina "Santa María de los Buenos Aires"; Argentina. Universidad Abierta Interamericana. Secretaría de Investigación. Centro de Altos Estudios En Ciencias Humanas y de la Salud - Sede Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Millán, Susana. No especifíca;Fil: Kilstein, Yael. No especifíca;Fil: Pereiro, Ana. Fundación Mundo Sano; ArgentinaFil: Sued, Omar. Fundación Huésped; ArgentinaFil: Cahn, Pedro. Fundación Huésped; ArgentinaFil: Spatz, Linus. Inmunova; ArgentinaFil: Goldbaum, Fernando Alberto. Inmunova; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; Argentina. Universidad Nacional de San Martin. Centro de Rediseño E Ingenieria de Proteinas.; Argentin

    Bacterial RNA and small antiviral compounds activate caspase-1 through cryopyrin/Nalp3

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    Missense mutations in the CIAS1 gene cause three autoinflammatory disorders: familial cold autoinflammatory syndrome, Muckle-Wells syndrome and neonatal-onset multiple-system inflammatory disease(1). Cryopyrin (also called Nalp3), the product of CIAS1, is a member of the NOD-LRR protein family that has been linked to the activation of intracellular host defence signalling pathways(2,3). Cryopyrin forms a multi-protein complex termed 'the inflammasome', which contains the apoptosis-associated speck-like protein (ASC) and caspase-1, and promotes caspase-1 activation and processing of pro-interleukin (IL)-1 beta (ref. 4). Here we show the effect of cryopyrin deficiency on inflammasome function and immune responses. Cryopyrin and ASC are essential for caspase-1 activation and IL-1 beta and IL-18 production in response to bacterial RNA and the imidazoquinoline compounds R837 and R848. In contrast, secretion of tumour-necrosis factor-alpha and IL-6, as well as activation of NF-kappa B and mitogen-activated protein kinases (MAPKs) were unaffected by cryopyrin deficiency. Furthermore, we show that Toll-like receptors and cryopyrin control the secretion of IL-1 beta and IL-18 through different intracellular pathways. These results reveal a critical role for cryopyrin in host defence through bacterial RNA-mediated activation of caspase-1, and provide insights regarding the pathogenesis of autoinflammatory syndromes.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62569/1/nature04517.pd

    Rheumatoid arthritis - clinical aspects: 134. Predictors of Joint Damage in South Africans with Rheumatoid Arthritis

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    Background: Rheumatoid arthritis (RA) causes progressive joint damage and functional disability. Studies on factors affecting joint damage as clinical outcome are lacking in Africa. The aim of the present study was to identify predictors of joint damage in adult South Africans with established RA. Methods: A cross-sectional study of 100 black patients with RA of >5 years were assessed for joint damage using a validated clinical method, the RA articular damage (RAAD) score. Potential predictors of joint damage that were documented included socio-demographics, smoking, body mass index (BMI), disease duration, delay in disease modifying antirheumatic drug (DMARD) initiation, global disease activity as measured by the disease activity score (DAS28), erythrocyte sedimentation rate (ESR), C reactive protein (CRP), and autoantibody status. The predictive value of variables was assessed by univariate and stepwise multivariate regression analyses. A p value <0.05 was considered significant. Results: The mean (SD) age was 56 (9.8) years, disease duration 17.5 (8.5) years, educational level 7.5 (3.5) years and DMARD lag was 9 (8.8) years. Female to male ratio was 10:1. The mean (SD) DAS28 was 4.9 (1.5) and total RAAD score was 28.3 (12.8). The mean (SD) BMI was 27.2 kg/m2 (6.2) and 93% of patients were rheumatoid factor (RF) positive. More than 90% of patients received between 2 to 3 DMARDs. Significant univariate predictors of a poor RAAD score were increasing age (p = 0.001), lower education level (p = 0.019), longer disease duration (p < 0.001), longer DMARD lag (p = 0.014), lower BMI (p = 0.025), high RF titre (p < 0.001) and high ESR (p = 0.008). The multivariate regression analysis showed that the only independent significant predictors of a higher mean RAAD score were older age at disease onset (p = 0.04), disease duration (p < 0.001) and RF titre (p < 0.001). There was also a negative association between BMI and the mean total RAAD score (p = 0.049). Conclusions: Patients with longstanding established RA have more severe irreversible joint damage as measured by the clinical RAAD score, contrary to other studies in Africa. This is largely reflected by a delay in the initiation of early effective treatment. Independent of disease duration, older age at disease onset and a higher RF titre are strongly associated with more joint damage. The inverse association between BMI and articular damage in RA has been observed in several studies using radiographic damage scores. The mechanisms underlying this paradoxical association are still widely unknown but adipokines have recently been suggested to play a role. Disclosure statement: C.I. has received a research grant from the Connective Tissue Diseases Research Fund, University of the Witwatersrand. All other authors have declared no conflicts of interes

    Integrating sequence and array data to create an improved 1000 Genomes Project haplotype reference panel

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    A major use of the 1000 Genomes Project (1000GP) data is genotype imputation in genome-wide association studies (GWAS). Here we develop a method to estimate haplotypes from low-coverage sequencing data that can take advantage of single-nucleotide polymorphism (SNP) microarray genotypes on the same samples. First the SNP array data are phased to build a backbone (or 'scaffold') of haplotypes across each chromosome. We then phase the sequence data 'onto' this haplotype scaffold. This approach can take advantage of relatedness between sequenced and non-sequenced samples to improve accuracy. We use this method to create a new 1000GP haplotype reference set for use by the human genetic community. Using a set of validation genotypes at SNP and bi-allelic indels we show that these haplotypes have lower genotype discordance and improved imputation performance into downstream GWAS samples, especially at low-frequency variants. © 2014 Macmillan Publishers Limited. All rights reserved

    Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

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    Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research
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