1,137 research outputs found

    Changes in Teaching During the Covid-19 Pandemic

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    During the confinement derived from the Covid-19 pandemic, many aspects of life changed; including, formal and informal economic activities were suspended. However, education could not be stopped, and for this reason, teachers found themselves in need of including ICT as part of their teaching strategies; seeing themselves in the obligation to modify their training practices. This paper analyzes the changes in teacher training during the confinement due to the pandemic. For this, a survey was made to teachers of the University Center of the Valleys of the University of Guadalajara, in order to rescue their experiences when training during this period. It would seem that the virtual training that was beginning to emerge, and was not yet very well accepted, came to satisfy or complement the learning needs, including disciplinary update courses, which were taught using technologies such as ClassRoom©, Youtube® transmissions, videoconferences via Meet© and Zoom®, which opened a wide panorama in terms of teacher training

    Refractory Ceramics Synthesis by Solid-State Reaction Between CaCO3 (Mollusk Shell) And Al2O3 Powders

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    Calcium aluminate-based refractory ceramic was developed as an innovative refractory material, using garden snail (Helix aspersa) shells as a natural source of CaCO3. A 1:1 molar ratio mixture of CaC O3 from snail shells and commercial Al2O3 powder was prepared by means of high-energy mechanical milling. The mixed powder was compacted in cylindrical samples (disks) and consolidated by sintering at 1450°C and 1500°C for 1h. The density and porosity were evaluated using the Archimedes principle, while the mechanical properties (hardness, fracture toughness, and shear modulus) were determined by indentation and ultrasonic methods, respectively. The thermal shock resistance was tested by heating samples to temperatures between 900 and 1400°C and subsequent quenching in water at room temperature. X-ray diffraction patterns of sintered samples indicate the formation of different calcium aluminate phases, such as CaAl12O (krotite/monoclinic),CaAl4O7 (grossite/monoclinic) and CaAl2O (hibonite-5H/hexagonal). The fracture toughness and shear modulus values of materials sintered at 1450°C were higher (0.48 MPa•m1/2)) and 59 GPa, respectively than those of materials sintered at 1500°C (0.43 MPa•m1/ 2 and 55 GPa, respectively). Also changes in the bulk density, hardness and thermal shock resistance values were observed in materials sintered at 1450°C and 1500°C

    First lunar outpost

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    Design and research efforts at the University of Puerto Rico have focused on the evaluation and refinement of the Habitability Criteria for a prolonged human presence in space during the last four years. Living quarters for a Mars mission and a third generation lunar base concept were proposed. This academic year, 1991-92, work on further refinement of the habitability criteria and design of partial gravity furniture was carried on. During the first semester, design alternatives for furniture necessary in a habitat design optimized for lunar and Martian environments were developed. Designs are based on recent research data from lunar and Mars gravity simulations, and current NASA standards. Artifacts will be submitted to NASA architects to be tested in KC-135 flights. Test findings will be submitted for incorporation in future updates to NASA habitat design standards. Second semester work was aimed at integrating these findings into the First Lunar Outpost (FLO), a mission scenario currently being considered by NASA. The mission consists of a manned return to the moon by crews of four astronauts for periods of 45 days. The major hardware components of the mission are as follows: (1) a Crew Module for the delivery of the crew and their supplies, and (2) the Habitat Module, which will arrive on the Moon unmanned. Our design efforts concentrated on this Habitat Module and on application of habitability criteria. Different geometries for the pressure vessel and their impact on the interior architecture were studied. Upon the selection of a geometry, a more detailed analysis of the interior design was performed, taking into consideration the reduced gravity, and the protection against radiation, micrometeorites, and the extreme temperature variation. A proposal for a FLO was submitted by the students, consisting essentially of a 24-feet (7.3 m.) by 35-feet (10.67 m) high vertical cylinder with work areas, crew quarters, galley, wardroom, leisure facilities, health maintenance, waste management, EVA operations facilities, and safe havens

    Invasive Pulmonary Adenocarcinoma with Lepidic Growth Pattern in a Pregnant Patient

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    Among the differential diagnoses that should be considered in acute respiratory failure (ARF) are infectious processes, autoimmune diseases, interstitial pulmonary fibrosis, and pulmonary neoplasia. Timely diagnosis of lung neoplasia is complicated in the early stages. An opportune diagnosis, as well as the specific treatment, decrease mortality. ARF occurs 1 in 500 pregnancies and is most common during the postpartum period. Among the specific etiologies that cause ARF during pregnancy that must be considered are: (1) preeclampsia; (2) embolism of amniotic fluid; (3) peripartum cardiomyopathy; and (4) trophoblastic embolism. The case of a 36-year-old patient with a 33-week pregnancy and ARF is presented. The patient presented dyspnea while exerting moderate effort that progressed to orthopnea and type 1 respiratory insufficiency. Imaging studies showed bilateral alveolar infiltrates and predominantly right areas of consolidation. Blood cultures, a galactomannan assay and IgG antibodies against mycoplasma pneumoniae, were reported as negative. Autoimmune etiology was ruled out through an immunoassay. A percutaneous pulmonary biopsy was performed and an invasive pulmonary adenocarcinoma with lepidic growth pattern (i.e. lepidic pulmonary adenocarcinoma, LPA) result was reported. This etiology is rare and very difficult to recognize in acute respiratory failure cases. After infectious, autoimmune and interstitial lung fibrosis have been excluded the clinician must suspect of lung cancer in a patient with acute respiratory failure and chest imaging compatible with the presence of ground-glass nodular opacities, a solitary nodule or mass with bronchogram, and lung consolidation. In the presence of acute respiratory failure, the suspicion of pulmonary neoplasia in an adult of reproductive age must be timely. Failure to recognize this etiology can lead to fatal results

    Total neutrino and antineutrino nuclear cross sections around 1 GeV

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    We investigate neutrino-nucleus interactions at energies around 1 GeV. In this regime, the main contributions to the cross sections come from quasi-elastic and Δ\Delta production processes. Our formalism, based on the Impulse Approximation is well suited to describe both types of interactions. We focus on a series of important nuclear effects in the interaction of electron neutrinos with 16O^{16}O, also relevant to future β\beta-Beams. Our results show that the Fermi gas model, widely used in data analysis of neutrino experiments, overestimates the total cross sections by as much as 20 %.Comment: 30 pages, 15 figure

    Prognosis of Transthyretin Cardiac Amyloidosis Without Heart Failure Symptoms.

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    BACKGROUND Transthyretin amyloid cardiomyopathy (ATTR-CM) is increasingly recognized as a treatable cause of heart failure (HF). Advances in diagnosis and therapy have increased the number of patients diagnosed at early stages, but prognostic data on patients without HF symptoms are lacking. Moreover, it is unknown whether asymptomatic patients benefit from early initiation of transthyretin (TTR) stabilizers. OBJECTIVES The aim of this study was to describe the natural history and prognosis of ATTR-CM in patients without HF symptoms. METHODS Clinical characteristics and outcomes of patients with ATTR-CM without HF symptoms were retrospectively collected at 6 international amyloidosis centers. RESULTS A total of 118 patients (78.8% men, median age 66 years [IQR: 53.8-75 years], 68 [57.6%] with variant transthyretin amyloidosis, mean left ventricular ejection fraction 60.5% ± 9.9%, mean left ventricular wall thickness 15.4 ± 3.1 mm, and 53 [45%] treated with TTR stabilizers at baseline or during follow-up) were included. During a median follow-up period of 3.7 years (IQR: 1-6 years), 38 patients developed HF symptoms (23 New York Heart Association functional class II and 14 functional class III or IV), 32 died, and 2 required cardiac transplantation. Additionally, 20 patients received pacemakers, 13 developed AF, and 1 had a stroke. Overall survival was 96.5% (95% CI: 91%-99%), 90.4% (95% CI: 82%-95%), and 82% (95% CI: 71%-89%) at 1, 3, and 5 years, respectively. Treatment with TTR stabilizers was associated with improved survival (HR: 0.31; 95% CI: 0.12-0.82; P = 0.019) and remained significant after adjusting for sex, age, ATTR-CM type, and estimated glomerular filtration rate (HR: 0.18; 95% CI: 0.06-0.55; P = 0.002). CONCLUSIONS After a median follow-up period of 3.7 years, 1 in 3 patients with asymptomatic ATTR-CM developed HF symptoms, and nearly as many died or required cardiac transplantation. Treatment with TTR stabilizers was associated with improved prognosis.This work was supported by grants from Instituto de Salud Carlos III (PI18/0765 and PI20/01379). Dr Gonzalez-Lopez has received speaker fees from Pfizer and Alnylam; has received consulting fees from Pfizer and Proclara; and has received research and educational support to her institution from Pfizer, BridgeBio, and Alnylam. Dr Obici has received speaker and consulting fees from Pfizer, Alnylam, and Akcea. Dr AbouEzzeddine has received research grant support from Pfizer. Dr Mussinelli has received speaker fees from Pfizer and Akcea. Dr Dispenzieri has received consulting fees from Janssen and Akcea; and has received research support from Pfizer, Alnylam, Celgene, and Takeda. Dr Perlini has received speaker and consulting fees from Pfizer, Alnylam, and Akcea. Dr Palladini has received speaker fees from Janssen-Cilag, Pfizer, and Siemens; and has participated on an advisory board for Janssen Cilag. Dr Damy has received research grants or consulting fees from Alnylam, Akcea, Pfizer, and Prothena. Dr Grogan has received research grant support and consulting fees to her institution from Alnylam, Eidos, Pfizer, and Prothena. Dr Maurer has received grant support from National Institutes of Health (R01HL139671-01, R21AG058348, and K24AG036778); has received consulting income from Pfizer, GlaxoSmithKline, Eidos, Prothena, Akcea, and Alnylam; and has received clinical trial funding to his institution from Pfizer, Prothena, Eidos, and Alnylam. Dr Garcia-Pavia has received speaker fees from Pfizer, BridgeBio, Alnylam, and Ionis; has received consulting fees from Pfizer, BridgeBio, AstraZeneca, NovoNordisk, Neuroimmune, Alnylam, Alexion, and Attralus; and has received research and educational support to his institution from Pfizer, BridgeBio, and Alnylam. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.S

    TFIIH is an elongation factor of RNA polymerase I

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    TFIIH is a multisubunit factor essential for transcription initiation and promoter escape of RNA polymerase II and for the opening of damaged DNA double strands in nucleotide excision repair (NER). In this study, we have analyzed at which step of the transcription cycle TFIIH is essential for transcription by RNA polymerase I. We demonstrate that TFIIH associates with the rDNA promoter and gene-internal sequences and leaves the rDNA promoter in a complex with RNA polymerase I after start of transcription. Moreover, mutations in the TFIIH subunits XPB and XPD found in Cockayne syndrome impair the interaction of TFIIH with the rDNA, but do not influence initiation complex formation or promoter escape of RNA polymerase I, but preclude the productivity of the enzyme by reducing transcription elongation in vivo and in vitro. Our results implicate that reduced RNA polymerase I transcription elongation and ribosomal stress could be one factor contributing to the Cockayne syndrome phenotype

    Burden and challenges of heart failure in patients with chronic kidney disease. A call to action

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    Patients with the dual burden of chronic kidney disease (CKD) and chronic congestive heart failure (HF) experience unacceptably high rates of symptom load, hospitalization, and mortality. Currently, concerted efforts to identify, prevent and treat HF in CKD patients are lacking at the institutional level, with emphasis still being placed on individual specialty views on this topic. The authors of this review paper endorse the need for a dedicated cardiorenal interdisciplinary team that includes nephrologists and renal nurses and jointly manages appropriate clinical interventions across the inpatient and outpatient settings. There is a critical need for guidelines and best clinical practice models from major cardiology and nephrology professional societies, as well as for research funding in both specialties to focus on the needs of future therapies for HF in CKD patients. The implementation of crossspecialty educational programs across all levels in cardiology and nephrology will help train future specialists and nurses who have the ability to diagnose, treat, and prevent HF in CKD patients in a precise, clinically effective, and cost-favorable manner.Los pacientes con enfermedad renal crónica (ERC) que desarrollan insuficiencia cardíaca (IC) congestiva crónica presentan cifras inaceptablemente altas de síntomas, hospitalización y mortalidad. Actualmente, se echan en falta iniciativas institucionales dirigidas a identificar, prevenir y tratar la IC en los pacientes con ERC de manera multidisciplinar, prevaleciendo las actuaciones de las especialidades individuales. Los autores de este artículo de revisión respaldan la necesidad de crear equipos multidisciplinares cardiorrenales, en los que participen nefrólogos y enfermeras renales, que gestionen colaborativamente las intervenciones clínicas apropiadas en los entornos de pacientes con ERC e IC hospitalizados y ambulatorios. Es necesario y urgente que se elaboren guías y modelos de práctica clínica sobre la ERC con IC por parte de las sociedades profesionales de cardiología y nefrología, así como financiación para la investigación concertada entre ambas especialidades sobre la necesidad de futuros tratamientos para la IC en pacientes con ERC. La implementación de programas educativos cardiorrenales a todos los niveles en cardiología y nefrología ayudará a formar a los futuros especialistas y enfermeras para que tengan la capacidad de diagnosticar, tratar y prevenir la IC en pacientes con ERC de manera precisa, clínicamente efectiva y económicamente favorabl

    Harmonized-Multinational qEEG Norms (HarMNqEEG)

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    This paper extends the frequency domain quantitative electroencephalography (qEEG) methods pursuing higher sensitivity to detect Brain Developmental Disorders. Prior qEEG work lacked integration of cross-spectral information omitting important functional connectivity descriptors. Lack of geographical diversity precluded accounting for site-specific variance, increasing qEEG nuisance variance. We ameliorate these weaknesses. i) Create lifespan Riemannian multinational qEEG norms for cross-spectral tensors. These norms result from the HarMNqEEG project fostered by the Global Brain Consortium. We calculate the norms with data from 9 countries, 12 devices, and 14 studies, including 1564 subjects. Instead of raw data, only anonymized metadata and EEG cross-spectral tensors were shared. After visual and automatic quality control, developmental equations for the mean and standard deviation of qEEG traditional and Riemannian DPs were calculated using additive mixed-effects models. We demonstrate qEEG "batch effects" and provide methods to calculate harmonized z-scores. ii) We also show that the multinational harmonized Riemannian norms produce z-scores with increased diagnostic accuracy to predict brain dysfunction at school-age produced by malnutrition only in the first year of life. iii) We offer open code and data to calculate different individual z-scores from the HarMNqEEG dataset. These results contribute to developing bias-free, low-cost neuroimaging technologies applicable in various health settings
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