131 research outputs found
Ultrasonic Real-Time Quality Monitoring Of Aluminum Spot Weld Process
The real-time ultrasonic spot weld monitoring system, introduced by our research group, has been designed for the unsupervised quality characterization of the spot welding process. It comprises the ultrasonic transducer (probe) built into one of the welding electrodes and an electronics hardware unit which gathers information from the transducer, performs real-time weld quality characterization and communicates with the robot programmable logic controller (PLC). The system has been fully developed for the inspection of spot welds manufactured in steel alloys, and has been mainly applied in the automotive industry. In recent years, a variety of materials have been introduced to the automotive industry. These include high strength steels, magnesium alloys, and aluminum alloys. Aluminum alloys have been of particular interest due to their high strength-to-weight ratio. Resistance spot welding requirements for aluminum vary greatly from those of steel. Additionally, the oxide film formed on the aluminum surface increases the heat generation between the copper electrodes and the aluminum plates leading to accelerated electrode deterioration. Preliminary studies showed that the real-time quality inspection system was not able to monitor spot welds manufactured with aluminum. The extensive experimental research, finite element modelling of the aluminum welding process and finite difference modeling of the acoustic wave propagation through the aluminum spot welds presented in this dissertation, revealed that the thermodynamics and hence the acoustic wave propagation through an aluminum and a steel spot weld differ significantly. For this reason, the hardware requirements and the algorithms developed to determine the welds quality from the ultrasonic data used on steel, no longer apply on aluminum spot welds. After updating the system and designing the required algorithms, parameters such as liquid nugget penetration and nugget diameter were available in the ultrasonic data acquired during the aluminum welding process. Finally, a fuzzy system was designed to receive these parameters and determine the weld quality
Aulas virtuales y rendimiento académico de estudiantes - Educación superior pedagógica Túpac Amaru - Tinta, 2019
La investigación, tuvo por objetivo, determinar la influencia de las aulas virtuales en el rendimiento académico de los estudiantes de la Escuela Superior Pedagógica Pública \"Túpac Amaru\" - Tinta, 2019, fue del tipo cuantitativo, y el diseño de investigación fue del tipo descriptivo correlacional, se tuvo una muestra de 36 estudiantes, a quienes se aplicó dos cuestionarios, uno para determinar el uso de aulas virtuales y el otro para determinan el rendimiento académico, los resultados y conclusiones fueron, que existió una relación positiva moderada con un valor de ,576 nivel de significancia de (,037,05), por lo tanto: las aulas virtuales no influyen significativamente en el rendimiento conductual de los estudiantes.Tesi
Production and Initial Characterization of Dad1p, a Component of the Dam1-DASH Kinetochore Complex
In all dividing eukaryotic cells, the mitotic spindle (composed primarily of microtubules) must interact with chromosomes through a complex protein assembly called the kinetochore. In Saccharomyces cerevisiae, the Dam1-DASH complex plays an important role in promoting attachment between the kinetochore and the mitotic spindle. It also actively participates in the physical separation of sister chromatids in anaphase. Understanding the biochemical mechanisms used by Dam1-DASH has been facilitated by bacterial co-expression of the ten Dam1-DASH genes, which results in the production of a heterodecameric protein complex that can be studied in vitro. However, individual protein subunits are not soluble when expressed in E. coli, thus precluding analysis of the nature of the interaction between subunits and an examination of the assembly of the functional complex. In this paper, we describe the expression, solubilization, purification and refolding of Dad1p, one of the Dam1-DASH complex subunits. In addition, we show that Dad1p, when isolated in this manner forms dimers and/or tetramers, dependent upon protein concentration. This work provides an important tool for studying the Dam1-DASH complex that was previously unavailable, and provides an avenue of investigation for understanding how the individual heterodecamers associate with each other to facilitate chromosome segregation
Coastal spatial-temporal changes with Landsat 8 and Sentinel2 imagine (2015-2019) in Central Chile; Reñaca Beach, Concón Bay and Algarrobo Bay
[EN] Due to their oceanographic and climatic ecological characteristics, the coastal areas of the Valparaíso Region of Chile are
of great importance for the country's tourist, economic, and environmental development. The region's coasts have been
affected by extreme events since 2015, with recurrent swells that have increased between 10% and 25% compared to
previous years, causing the interruption of the annual dynamic process of the beaches accentuated by anthropic
interventions on beaches, wetlands and coastal dunes that promote coastal degradation. This work aims to characterize
which part of the beaches and at what time of year there is a higher risk of severe erosion in the immediate areas to the
coast and explain its causes based on satellite images of medium resolution satellite images. 128 SDS were extracted with
Landsat 8 OLI and Sentinel 2 images with systems SHOREX. Average widths calculated for the series in each of the
seasons. Recording the minimum widths in the proximal areas with averages of 12.3 m; 23.6 m and 21.2 m Concón Bay,
Reñaca Beach and Algarrobo bay, respectively showing critical or problematic states. The dominant direction of the waves
and the geographical disposition of the three beaches seems evident that there is a robust longitudinal transport to the
north that generates less sediment accumulation in the proximal areas. The seasonal variation of the beaches distinguishes
by more energetic conditions in winter than in summer. But they are also influenced by rapid episodic periods, low
atmospheric pressure systems from the north and south, swells and tropical storms. Hence, it is unlikely that the variations
in the width of the beach are only due to winter-summer energetic conditions.[ES] Las áreas costeras de la región de Valparaíso de Chile por sus características oceanográficas, climáticas y ecológicas
son de gran importancia para el desarrollo turístico, económico y ambiental del país. Las costas de la región se han visto
afectadas por eventos extremos desde 2015, con marejadas recurrentes que han aumentado respecto a años anteriores
entre el 10% y 25%. Esto ha provocado la interrupción del proceso dinámico anual de las playas, acentuado por las
intervenciones antrópicas sobre estos ambientes costeros, humedales y dunas que promueven su degradación. El trabajo
que se presenta tiene como objetivo caracterizar en qué parte de las playas y en qué momento del año hay un riesgo más
alto de erosión grave en las áreas inmediatas a la costa, así como tratar de explicar sus causas apoyándose en la
utilización de imágenes satelitales de resolución media. Se extrajeron 128 SDS con imágenes Landsat 8 OLI y Sentinel 2
con el sistema SHOREX. Se calcularon los valores promedio de anchura de playa para la serie en cada una de las
temporadas registrando anchuras mínimas en las zonas proximales de 12,3 m; 23,6 m y 21,2 m para la Bahía de Concón,
Playa Reñaca y Bahía de Algarrobo respectivamente, demostrando estados críticos o problemáticos. La dirección
dominante del oleaje y la disposición geográfica de las tres playas hace evidente la existencia de un fuerte transporte
longitudinal hacia el norte que genera que las áreas proximales presenten menor acumulación de sedimentos. La variación
estacional de las playas se caracteriza por condiciones más energéticas en invierno que en verano. No obstante, se ven
también influenciadas por periodos episódicos rápidos, sistemas de bajas presiones atmosféricas del norte y del sur, así
como marejadas y tormentas tropicales que se suman al moldeamiento de las playas.Este trabajo ha sido financiado por la Agencia Nacional de Investigación y Desarrollo (ANID) a través del FONDEF IDeA I+D 2019 – Desafío País Adaptación al
Cambio Climático y Desastres Naturales. Código Proyecto ID19I10361. Agradecimiento a los practicantes de Escuela de Geología de la Universidad Mayor por su
colaboración en la toma de datos en campo y procesamiento de datos sedimentarios. Álvaro Millamán, Maximiliano Parrao, Catalina Cerda, Nicolás Rodríguez,
a las asistentes, Natalia Medina, Roxana Mansilla. Al IHC Cantabria que nos ha cedido datos de oleaje y marea de la zona.Briceño De Urbaneja, I.; Sánchez-García, E.; Pardo Pascual, JE.; Palomar Vázquez, JM.; Ugalde-Peralta, R.; Aguirre-Galaz, C.; Perez Martinez, W.... (2021). Cambios espacio-temporales costeros con imágenes Landsat 8 y Sentinel 2 (2015-2019) en Chile Central; Playa Reñaca, Bahía de Concón y Bahía de Algarrobo. En Proceedings 3rd Congress in Geomatics Engineering. Editorial Universitat Politècnica de València. 302-310. https://doi.org/10.4995/CiGeo2021.2021.12766OCS30231
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
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
Cardiovascular development: towards biomedical applicability: Epicardium-derived cells in cardiogenesis and cardiac regeneration
During cardiogenesis, the epicardium grows from the proepicardial organ to form the outermost layer of the early heart. Part of the epicardium undergoes epithelial-mesenchymal transformation, and migrates into the myocardium. These epicardium- derived cells differentiate into interstitial fibroblasts, coronary smooth muscle cells, and perivascular fibroblasts. Moreover, epicardium-derived cells are important regulators of formation of the compact myocardium, the coronary vasculature, and the Purkinje fiber network, thus being essential for proper cardiac development. The fibrous structures of the heart such as the fibrous heart skeleton and the semilunar and atrioventricular valves also depend on a contribution of these cells during development. We hypothesise that the essential properties of epicardium-derived cells can be recapitulated in adult diseased myocardium. These cells can therefore be considered as a novel source of adult stem cells useful in clinical cardiac regeneration therapy
Ciencias de la Biología y Agronomía
Este volumen I contiene 17 capítulos arbitrados que se ocupan de estos asuntos en Tópicos Selectos de Ciencias de la Biología y Agronomía, elegidos de entre las contribuciones, reunimos algunos investigadores y estudiantes. Se presenta un Estudio Comparativo de los Recursos Hidrológico-Forestales de la Microcuenca de la Laguna de Epatlan, Pue. (1993 a 2014); la Situación Actual de la Mancha de Asfalto en Maíz (Zea mays L.) en los Municipios de Jiquipilas y Ocozocoautla, Chiapas, México; las poblaciones sobresalientes de maíz de la raza Zapalote Chico, en la Región Istmeña de Oaxaca; Se indica el índice de área foliar de cultivo de Chile Poblano mediante dos métodos en condiciones protegidas; Esquivel, Urzúa y Ramírez exploran el efecto de la biofertilización con Azospirillum en el crecimiento y producción de Jitomate; esbozan su artículo sobre la determinación del nivel de Heterosis en híbridos de Maíz para la Comarca Lagunera; una investigación sobre la estabilización de semilla de Solanum lycopersicum durante el almacenamiento y estimulación de la germinación; acotan sobre el CTAB como una nueva opción para la detección de Huanglongbing en cítricos, plantean su evaluación sobre el aluminio y cómo afecta la vida de florero de Heliconia psittacorum; indican sobre el impacto del H-564C, como un híbrido de maíz con alta calidad de proteina para el trópico húmedo de México; presetan su investigación sobre la producción de Piña Cayena Lisa y MD2 (Ananas comosus L.) en condiciones de Loma Bonita, en Oaxaca; acotan sobre el efecto de coberteras como control biológico por conservación contra áfidos en Nogal Pecanero; esbozan sobre la caracterización de cuatro genotipos de Frijol Negro en Martínez de la Torre, Veracruz, México; presentan una caracterización hidroecológica de la microcuenca de Arroyo Prieto, Yuriría, Gto., y alternativas para su restauración ambiental; presentan su investigación sobre el efecto del hongo Beauveria bassiana sobre solubilización de fosfatos y la disponibilidad de fósforo en el suelo; plantean su investigación sobre la Germinación y regeneración in vitro de Epidendrum falcatum LINDL; esbozan su artículo sobre genotipos de frijol negro y su tolerancia a sequía terminal en Veracruz, México
Long term outcome of cavotricuspid isthmus cryoablation for the treatment of common atrial flutter in 180 patients: A single center experience
Pathogenic Huntingtin Repeat Expansions in Patients with Frontotemporal Dementia and Amyotrophic Lateral Sclerosis.
We examined the role of repeat expansions in the pathogenesis of frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS) by analyzing whole-genome sequence data from 2,442 FTD/ALS patients, 2,599 Lewy body dementia (LBD) patients, and 3,158 neurologically healthy subjects. Pathogenic expansions (range, 40-64 CAG repeats) in the huntingtin (HTT) gene were found in three (0.12%) patients diagnosed with pure FTD/ALS syndromes but were not present in the LBD or healthy cohorts. We replicated our findings in an independent collection of 3,674 FTD/ALS patients. Postmortem evaluations of two patients revealed the classical TDP-43 pathology of FTD/ALS, as well as huntingtin-positive, ubiquitin-positive aggregates in the frontal cortex. The neostriatal atrophy that pathologically defines Huntington's disease was absent in both cases. Our findings reveal an etiological relationship between HTT repeat expansions and FTD/ALS syndromes and indicate that genetic screening of FTD/ALS patients for HTT repeat expansions should be considered
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