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En la actualidad las Tecnologías de la Información y Comunicación (TICs) ofrecen un amplio acceso a diversas herramientas educativas que sirven de complemento a la educación tanto presencial como online; por tanto, corresponde a las instituciones estar a la vanguardia y proporcionar al docente las herramientas tecnológicas necesarias para generar mejores condiciones que propicien un aprendizaje significativo. En este sentido, surge la necesidad de analizar el uso de las TICs durante la pandemia COVID-19 como complemento para el docente en el proceso de enseñanza-aprendizaje. El objetivo de la presente investigación fue analizar el uso de Google Classroom durante el periodo marzo 2020 a febrero 2021, herramienta que sirvió de apoyo a los docentes para la comunicación con sus estudiantes de la Universidad Popular de la Chontalpa. Para tal fin, se aplicó una encuesta que permitió conocer la percepción de 150 docentes de la División de Ciencias Económico-Administrativas (DCEA) hacia el uso de la plataforma. El análisis de los datos se realizó mediante gráficas y su respectiva descripción donde se encontró que la mayoría de los docentes ingresaban a la plataforma para crear clases online con los alumnos, aunque su nivel de conocimiento era básico este software les permitió mantener la interacción con los estudiantes durante el periodo de suspensión de clases presenciales por causa del COVID-19; se percibió una actitud de aceptación hacia su uso por pate de docentes y estudiantes. Finalmente, se realizaron recomendaciones para continuar con la formación docente, a nivel intermedio y avanzado, sobre el funcionamiento y manejo de la plataforma Google Classroom, así como la creación de un área que proporcione asesoramiento a profesores y estudiantes en relación a las TICs en la Universidad Popular de la Chontalpa.

The article describes the gifted education programs offered at Kent State University (OH), which include five degree programs from the bachelor through the doctoral levels. (PHR)

En trabajo se desarrolla la cronología de las inundaciones costeras en el litoral sur de la provincia las Tunas. El objetivo de la investigación es determinar las particularidades de las inundaciones costeras en el sur de Las Tunas generadas por ciclones tropicales, en el período 1932-2020. Dentro de los materiales y métodos que fueron utilizados se encuentran como fuentes de información, los archivos de reanálisis de la NOAA, los datos del NHC (National Hurricane Center), ambos disponibles en internet, datos del Instituto de Meteorología de Cuba (INSMET) y del Centro Meteorológico Provincial de Las Tunas, así como testimonios locales obtenidos de entrevistas a los pobladores y reportes de prensa. Además, se empleó la distribución de Poisson y para determinar si la distribución de probabilidad escogida es idónea, se empleó la prueba no paramétrica de Pearson X² para variables discretas lo que permitió obtener los períodos de retorno de los ciclones tropicales para el área y de los eventos de inundación, donde se espera que un evento de inundación identificado de cierta importancia, ocurra al menos una vez cada 7.9 años. Los resultados obtenidos son aplicables en la elaboración de los pronósticos de inundaciones costeras en la zona, así como en los planes de contingencias y en acciones de manejo costero, por lo que se recomienda sea utilizado por las entidades responsables de estas actividades.

We use subhalo abundance and age distribution matching to create magnitude-limited mock galaxy catalogs at z ∼ 0.43, 0.52, and 0.63 with z -band and 3.4 μ m W 1-band absolute magnitudes and r − z and r − W 1 colors. From these magnitude-limited mocks, we select mock luminous red galaxy (LRG) samples according to the ( r − z )-based (optical) and ( r − W 1)-based (infrared) selection criteria for the LRG sample of the Dark Energy Spectroscopic Instrument (DESI) survey. Our models reproduce the number densities, luminosity functions, color distributions, and projected clustering of the DESI Legacy Surveys that are the basis for DESI LRG target selection. We predict the halo occupation statistics of both optical and IR DESI LRGs at fixed cosmology and assess the differences between the two LRG samples. We find that IR-based SHAM modeling represents the differences between the optical and IR LRG populations better than using the z band and that age distribution matching overpredicts the clustering of LRGs, implying that galaxy color is uncorrelated with halo age in the LRG regime. Both the optical and IR DESI LRG target selections exclude some of the most luminous galaxies that would appear to be LRGs based on their position on the red sequence in optical color–magnitude space. Both selections also yield populations with a nontrivial LRG–halo connection that does not reach unity for the most massive halos. We find that the IR selection achieves greater completeness (≳90%) than the optical selection across all redshift bins studied.

The planned MADIT-CRT trial is designed to determine if CRT-D will reduce the risk of mortality and HF events by approximately 25% in subjects with ischemic (NYHA class I-II) and non-ischemic (NYHA class II) cardiomyopathy, left ventricular dysfunction (EFor=130 ms). [ABSTRACT FROM AUTHOR]

Implantable cardioverter defibrillators (ICDs) with dual chamber and duo! chamber rate responsive pacing may offer hemodynamic advantages for some ICD patients. Separate ICDs and DDDR pacemakers can result in device to device interactions, inappropriate shocks, and underdetection of ventricular fibrillation (VF). The objectives of this study were to compare the VF detection times between the Ventak AV II DB and the Ventak AV during high rate DDDR and DDD pacing and to test the safety of dynamic ventricular refractory period shortening. Patients receiving an ICD were randomized in a paired comparison to pacing at 150 beats/min (DDD pacing) or 175 beats/min (DDDR pacing) during ICD threshold testing to create a 'worst case scenario' for VF detection. The VF detection rate was set to 180 beats/min. and VF was induced during high rate pacing with alternating current. The device was then allowed to detect and treat VF. The induction was repeated for each patient at each programmed setting so that all patients were tested at both programmed settings. Paired analysis was performed. Patient characteristics were a mean age of 69 ± 11 years, 78% were men, coronary artery disease was present in 85%, and a mean left ventricular ejection fraction of 0.34 ± 0.11. Fifty-two episodes of VF were induced in 26 patients. Despite the high pacing rate, all VF episodes were appropriately detected. The mean VF detection time was 2.4 ± 1.0 seconds during DDD pacing and 2.9 ± 1.9 seconds during DDDH pacing (P - NS). DDD and DDDR programming resulted in appropriate detection of all episodes of VF with similar detection times despite the 'worst case scenario' tested. Delays in detection may be seen with long programmed ventricular refractory periods which shorten the VF sensing window and may be avoided with dynamic ventricular refractory period shortening. [ABSTRACT FROM AUTHOR]

The Ventak AV is an implantable cardioverter defibrillator with dual chamber pacing capability. Features include detection and treatment of ventricular arrhythmias, detection of atrial arrhythmias, as well as dual chamber pacing. The objective of the investigation was to verify the efficacy of the Ventak AV in detecting ventricular fibrillation in the presence of dual chamber pacing. Thirty-three patients, who were to receive an implantable defibrillator were randomized (1:1) in a paired comparison study to the Ventak AV (study device) and the Ventak Mini (control) during defibrillation threshold testing. In order to create a 'worst case scenario' for sensing of ventricular fibrillation, pacing was performed at high lower rate limit values (Ventak AV DDD pacing at 150/min, Ventak Mini at VVI 100/min). Ventricular fibrillation was induced and the randomized device was allowed to detect and treat the arrhythmia. This test was repeated for each patient using the alternate device in a randomized order, such that all patients were tested with both devices. The mean ventricular fibrillation detection time for the Ventak AV was 2.0 ± 0.11 seconds and for the control device the detection time was 1.8 ± 0.11 seconds (P = 0.26). Appropriate tachyarrhythmia therapy decision was documented in all episodes for both devices. The study patient population demonstrated equivalent ventricular fibrillation detection time between the Ventak AV and the Ventak Mini. The Ventak AV demonstrated effectiveness in detecting ventricular fibrillation in the presence of high rate dual chamber pacing. [ABSTRACT FROM AUTHOR]

A modified Pseudomonas aeruginosa strain capable of overexpressing the estA gene, an encoding gene for a membrane-bound esterase, was constructed and its rhamnolipid (RML) production was studied. Fermentations using wild-type (WT) and modified P. aeruginosa strains were conducted until exhaustion of glycerol in Medium Salt Production, using two different C/N ratios. At a C/N of 83.2, the modified strain produced up to 3.9 times more RMLs than the WT, yielding a maximum concentration of 14.62 g/L RML when measured by HPLC and 22 g/L by the orcinol assay. Cell-free supernatant from the modified strain reduced surface tension to 29.4 mN/m and had a CMC of 240 mg/L and CMD of 56.05. This is the first report on the construction of an estA-based recombinant strain for RML production.

The accumulation of salts in the soil is a common problem of arid and semi-arid regions, that cause reduction in plant growth and yield. In this context, the arbuscular mycorrhizal fungi (AMF) have been studied in recent years, with results indicating that their associations with the plant roots minimize some effects of salt stress. The objective of this work was to evaluate the influence of increasing levels of salinity of the irrigation water in the melon plants mycorrhized with AMF. The experiment design was completely randomized in factorial 2 x 4 corresponding to two mycorrhiza treatments (inoculated and not inoculated plants) x 4 levels of salinity (ECw = 0.5, 1.5, 3.0 and 4.5 dS m-1), with 4 replicates.The mycorhizal colonization, plant growth, leaf gas exchange and the concentrations and contents of ions (N, P, K+, Na+ e Cl-) were measured. The mycorrhized plants showed higher production of shoot dry matter and leaf area, in relation to non-inoculated plants, mainly in the 0.5 dS m-1 treatment. However, this beneficial effect decreased with salinity levels increasing. Stomatal conductance, transpiration rate and photosynthetic rate were positively influenced by AMF, the values being higher in mycorrhized plants. The results showed a peak of colonization in treatment with EC of 1.36 dS m-1 with a tendency to decrease in higher salt concentrations. The symbiotic association between AMF and melon roots increased the contents of N, P and K, at low and medium salinity, and reduced the absorption of potentially toxic ions (Na, Cl) from the salinity caused by irrigation water with 3.0 dS m – 1. Nas regiões áridas e semiáridas é comum a acumulação de sais no solo em quantidades prejudiciais ao crescimento e rendimento das plantas. Neste contexto, os fungos micorrízicos arbusculares (FMA) vem sendo estudados nos últimos anos, havendo resultados que indicam que as associações micorrízicas com as plantas minimizam alguns efeitos do estresse salino. O objetivo foi avaliar os efeitos da inoculação dos fungos micorrízicos arbusculares na cultura do meloeiro sob estresse salino. O delineamento experimental utilizado foi o inteiramente casualizado, em arranjo fatorial 2 x 4, correspondendo a 2 tratamentos micorrízicos (plantas inoculadas e não inoculadas) e 4 níveis de salinidade (CEa): 0,5, 1,5, 3,0 e 4,5 dS m-1, com 4 repetições. Foram avaliadas a colonização micorrízica, o crescimento, as trocas gasosas foliares e os teores e conteúdos de N, P, K+, Na+ e Cl- nas plantas. A associação com FMA proporcionou um incremento na produção matéria seca da parte aérea e na área foliar; porém, este efeito benéfico decresceu com o aumento da salinidade. Os FMA também influenciaram de forma positiva a condutância estomática, taxa de transpiração e fotossintética. Os resultados mostraram um pico de colonização na CEa de 1,36 dS m-1 com tendência de redução a partir deste nível de salinidade. Verificou-se ainda que a associação simbiótica entre FMA e meloeiro proporcionou aumento nos totais extraídos de N, P e K+, principalmente nos níveis baixos e médios de salinidade, e redução na absorção dos íons potencialmente tóxicos (Na+ e Cl-) a partir da salinidade da água de irrigação de 3,0 dS m-1.