Learning Together in Public and in Private: Exploring Learner Interactions and Engagement in a Blended-Platform MOOC Environment

With the growing popularity of connectivist MOOCs, the aim of facilitators has increasingly shifted from helping students meet completion-oriented goals to encouraging meaningful engagement among participants. In this paper, we study the relationship between platform of engagement and learner participation, controlling for relevant demographic factors of participants including gender, age, and level of education attained. Our study employs four distinct measures of participatory engagement: autonomous learning, knowledge reproduction, information networking, and scholarly engagement. We find that on the public platform of Twitter, participants were more likely to exhibit meaningful engagement patterns across all measures studied than they were on the closed EdX class discussion space

The effect of n-acetylcysteine on hepatic histomorphology during hypothermic preservation

PURPOSE:To evaluate the NAC effects on liver hypothermic preservation at different time intervals.METHODS:For this, we used livers of male Wistar rats weighing between 250 and 300g, undergoing preservation in Ringer solution at 4°C for up to 24 hours. Tissue samples were obtained at four moments of preservation for histological examination by hematoxylin and eosin staining: T0 = beginning of preservation, T12 = 12 hours, T18 = 18 hours and T24 = 24 hours. Will be analyzed vacuolation, hepatic apoptosis by optical microscopy and parenchymal.RESULTS: The results showed a progressive increase in hepatic injury in both groups and showed that NAC was effective at T0. The parenchyma preservation was better in the NAC group and no difference when vacuolization of the cells.CONCLUSION: Hypothermic preservation, over time, causes changes in the hepatic parenchyma with increased apoptosis, loss of architecture, vacuolization, culminating in severe injury. The administration of N-acetylcysteine protects against preservation liver injury.University City of São PauloSão Paulo University Medical SchoolFederal University of São Paulo Paulista Medicine SchoolUNIFESP, Paulista Medicine SchoolSciEL

Higienización de lodos de la planta de tratamiento de aguas residuales domésticas de Manchay, y su uso como insumo de cultivo en el año 2021

El presente estudio buscó evaluar la posibilidad de higienización de los lodos provenientes de la PTARD Manchay y se verificó la efectividad en su uso como insumo de cultivos. Para ello, se identificaron los lodos de la PTARD, proveniente de un sistema de tratamiento de lodos activados, los cuales son dispuestos en un relleno sanitario. Al realizar el análisis preliminar de los lodos, y tras su comparación con la normativa, nos indicó el cumplimiento de parámetros químicos, sin embargo, no se cumplió con los parámetros biológicos (Salmonella) de acuerdo con el D.S. N° 015-2017-VIVIENDA. Posteriormente, se realizó la higienización mediante la aplicación de cal viva en un 20 y 30 % por un periodo de 7 días, para luego ser analizados en laboratorio, a fin de determinar su clase y uso de acuerdo con el Decreto Supremo N° 015-2017-VIVIENDA y la Normativa Oficial Mexicana NOM-004-SEMARNAT-2002. Los resultados muestran que los lodos tratados con el 20 % de cal viva son clasificados como de clase B, a diferencia de los lodos tratados con el 30 % de cal viva que fueron clasificados de clase A para ambas normativas. Una vez que el lodo fue caracterizado, se aplicaron diferentes porcentajes de los lodos tratados (15, 35 y 50 %) como insumo en los cultivos de la zanahoria y betarraga hasta su etapa de germinación, haciendo uso de la escala extendida BBCH. Se determinó que los cultivos de zanahoria germinan entre los 15 y 30 días, siendo el tratamiento TH2Z2, el que germinó en 16 días. En comparación con las semillas de betarraga, que germinaron entre los 10 y 15 días, sin embargo, fue el placebo quien germinó en un periodo de 12 días. Finalmente realizando el análisis costo beneficio se estimó que la higienización de los lodos es una alternativa rentable y óptima por la reducción de costos que genera al reusar los lodos, en comparación con los gastos que actualmente se dan por el traslado hacia un relleno sanitario. Se concluyó que es posible la higienización de los lodos de la PTARD de Manchay y su uso como insumo en los cultivos de zanahoria y betarraga, además que su implementación permite una reducción en los costos de traslado

Hypertonic saline and pentoxifylline enhance survival, reducing apoptosis and oxidative stress in a rat model of strangulated closed loop small bowel obstruction

OBJECTIVES: Intestinal obstruction has a high mortality rate when therapeutic treatment is delayed. Resuscitation in intestinal obstruction requires a large volume of fluid, and fluid combinations have been studied. Therefore, we evaluated the effects of hypertonic saline solution (HS) with pentoxifylline (PTX) on apoptosis, oxidative stress and survival rate. METHODS: Wistar rats were subjected to intestinal obstruction and ischemia through a closed loop ligation of the terminal ileum and its vessels. After 24 hours, the necrotic bowel segment was resected, and the animals were randomized into four groups according to the following resuscitation strategies: Ringer’s lactate solution (RL) (RL-32 ml/kg); RL+PTX (25 mg/kg); HS+PTX (HS, 7.5%, 4 ml/kg), and no resuscitation (IO-intestinal obstruction and ischemia). Euthanasia was performed 3 hours after resuscitation to obtain kidney and intestine samples. A malondialdehyde (MDA) assay was performed to evaluate oxidative stress, and histochemical analyses (terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling [TUNEL], Bcl-2 and Bax) were conducted to evaluate kidney apoptosis. Survival was analyzed with another series of animals that were observed for 15 days. RESULTS: PTX in combination with RL or HS reduced the MDA levels (nmol/mg of protein), as follows: kidney IO=0.42; RL=0.49; RL+PTX=0.31; HS+PTX=0.34 (po0.05); intestine: IO=0.42; RL=0.48; RL+PTX=0.29; HS +PTX=0.26 (po0.05). The number of labeled cells for TUNEL and Bax was lower in the HS+PTX group than in the other groups (po0.05). The Bax/Bcl-2 ratio was lower in the HS+PTX group than in the other groups (po0.05). The survival rate on the 15th day was higher in the HS+PTX group (77%) than in the RL+PTX group (11%). CONCLUSION: PTX in combination with HS enhanced survival and attenuated oxidative stress and apoptosis. However, when combined with RL, PTX did not reduce apoptosis or mortalit

Estudio de viabilidad y sostenibilidad de un plan de negocio para la producci?n y comercializaci?n de calzado femenino en la empresa negociaciones Fabio Vatelli EIRL

El presente plan de negocio analiza la viabilidad de una nueva l?nea de negocio que presenta un nuevo concepto de calzado femenino para el uso laboral, enfocado en la comodidad y confort, en la empresa Negociaciones Fabio Vatelli EIRL, empresa familiar en operaci?n, dedicada en la actualidad a la producci?n y comercializaci?n de calzado masculino. El objetivo principal es determinar si es viable esta nueva l?nea de negocio para Negociaciones Fabio Vatelli EIRL implementar la nueva l?nea de calzado femenino. Para tal efecto se plantean los siguientes objetivos espec?ficos: - Realizar el an?lisis de la situaci?n actual de la industria de calzado en el Per?. - Realizar una investigaci?n de mercado para determinar la demanda del producto. - Proponer una nueva l?nea de negocio, cuyo producto y servicio se define basado en el estudio de mercado y la competencia - Proponer la estrategia para la puesta en marcha y los planes funcionales de marketing, operaciones y recursos humanos. - Evaluar econ?mica y financieramente el negocio propuesto

Global data set of long-term summertime vertical temperature profiles in 153 lakes

Climate change and other anthropogenic stressors have led to long-term changes in the thermal structure, including surface temperatures, deepwater temperatures, and vertical thermal gradients, in many lakes around the world. Though many studies highlight warming of surface water temperatures in lakes worldwide, less is known about long-term trends in full vertical thermal structure and deepwater temperatures, which have been changing less consistently in both direction and magnitude. Here, we present a globally-expansive data set of summertime in-situ vertical temperature profiles from 153 lakes, with one time series beginning as early as 1894. We also compiled lake geographic, morphometric, and water quality variables that can influence vertical thermal structure through a variety of potential mechanisms in these lakes. These long-term time series of vertical temperature profiles and corresponding lake characteristics serve as valuable data to help understand changes and drivers of lake thermal structure in a time of rapid global and ecological change

Dual-tasking and gait in people with Mild Cognitive Impairment. The effect of working memory

<p>Abstract</p> <p>Background</p> <p>Cognition and mobility in older adults are closely associated and they decline together with aging. Studies evaluating associations between cognitive factors and gait performance in people with Mild Cognitive Impairment (MCI) are scarce. In this study, our aim was to determine whether specific cognitive factors have a more identifiable effect on gait velocity during dual-tasking in people with MCI.</p> <p>Methods</p> <p>Fifty-five participants, mean age 77.7 (SD = 5.9), 45% women, with MCI were evaluated for global cognition, working memory, executive function, and attention. Gait Velocity (GV) was measured under a single-task condition (single GV) and under two dual-task conditions: 1) while counting backwards (counting GV), 2) while naming animals (verbal GV). Multivariable linear regression analysis was used to examine associations with an alpha-level of 0.05.</p> <p>Results</p> <p>Participants experienced a reduction in GV while engaging in dual-task challenges (p < 0.005). Low executive function and working memory performances were associated with slow single GV (p = 0.038), slow counting GV (p = 0.017), and slow verbal GV (p = 0.031). After adjustments, working memory was the only cognitive factor which remained significantly associated with a slow GV.</p> <p>Conclusion</p> <p>In older adults with MCI, low working memory performance was associated with slow GV. Dual-task conditions showed the strongest associations with gait slowing. Our findings suggest that cortical control of gait is associated with decline in working memory in people with MCI.</p

The Baryon Oscillation Spectroscopic Survey of SDSS-III

The Baryon Oscillation Spectroscopic Survey (BOSS) is designed to measure the scale of baryon acoustic oscillations (BAO) in the clustering of matter over a larger volume than the combined efforts of all previous spectroscopic surveys of large scale structure. BOSS uses 1.5 million luminous galaxies as faint as i=19.9 over 10,000 square degrees to measure BAO to redshifts z<0.7. Observations of neutral hydrogen in the Lyman alpha forest in more than 150,000 quasar spectra (g<22) will constrain BAO over the redshift range 2.15<z<3.5. Early results from BOSS include the first detection of the large-scale three-dimensional clustering of the Lyman alpha forest and a strong detection from the Data Release 9 data set of the BAO in the clustering of massive galaxies at an effective redshift z = 0.57. We project that BOSS will yield measurements of the angular diameter distance D_A to an accuracy of 1.0% at redshifts z=0.3 and z=0.57 and measurements of H(z) to 1.8% and 1.7% at the same redshifts. Forecasts for Lyman alpha forest constraints predict a measurement of an overall dilation factor that scales the highly degenerate D_A(z) and H^{-1}(z) parameters to an accuracy of 1.9% at z~2.5 when the survey is complete. Here, we provide an overview of the selection of spectroscopic targets, planning of observations, and analysis of data and data quality of BOSS.Comment: 49 pages, 16 figures, accepted by A

The Ninth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the SDSS-III Baryon Oscillation Spectroscopic Survey

The Sloan Digital Sky Survey III (SDSS-III) presents the first spectroscopic data from the Baryon Oscillation Spectroscopic Survey (BOSS). This ninth data release (DR9) of the SDSS project includes 535,995 new galaxy spectra (median z=0.52), 102,100 new quasar spectra (median z=2.32), and 90,897 new stellar spectra, along with the data presented in previous data releases. These spectra were obtained with the new BOSS spectrograph and were taken between 2009 December and 2011 July. In addition, the stellar parameters pipeline, which determines radial velocities, surface temperatures, surface gravities, and metallicities of stars, has been updated and refined with improvements in temperature estimates for stars with T_eff<5000 K and in metallicity estimates for stars with [Fe/H]>-0.5. DR9 includes new stellar parameters for all stars presented in DR8, including stars from SDSS-I and II, as well as those observed as part of the SDSS-III Sloan Extension for Galactic Understanding and Exploration-2 (SEGUE-2). The astrometry error introduced in the DR8 imaging catalogs has been corrected in the DR9 data products. The next data release for SDSS-III will be in Summer 2013, which will present the first data from the Apache Point Observatory Galactic Evolution Experiment (APOGEE) along with another year of data from BOSS, followed by the final SDSS-III data release in December 2014.Comment: 9 figures; 2 tables. Submitted to ApJS. DR9 is available at http://www.sdss3.org/dr

The 13th Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the SDSS-IV Survey Mapping Nearby Galaxies at Apache Point Observatory

The fourth generation of the Sloan Digital Sky Survey (SDSS-IV) began observations in July 2014. It pursues three core programs: APOGEE-2,MaNGA, and eBOSS. In addition, eBOSS contains two major subprograms: TDSS and SPIDERS. This paper describes the first data release from SDSS-IV, Data Release 13 (DR13), which contains new data, reanalysis of existing data sets and, like all SDSS data releases, is inclusive of previously released data. DR13 makes publicly available 1390 spatially resolved integral field unit observations of nearby galaxies from MaNGA,the first data released from this survey. It includes new observations from eBOSS, completing SEQUELS. In addition to targeting galaxies and quasars, SEQUELS also targeted variability-selected objects from TDSS and X-ray selected objects from SPIDERS. DR13 includes new reductions ofthe SDSS-III BOSS data, improving the spectrophotometric calibration and redshift classification. DR13 releases new reductions of the APOGEE-1data from SDSS-III, with abundances of elements not previously included and improved stellar parameters for dwarf stars and cooler stars. For the SDSS imaging data, DR13 provides new, more robust and precise photometric calibrations. Several value-added catalogs are being released in tandem with DR13, in particular target catalogs relevant for eBOSS, TDSS, and SPIDERS, and an updated red-clump catalog for APOGEE.This paper describes the location and format of the data now publicly available, as well as providing references to the important technical papers that describe the targeting, observing, and data reduction. The SDSS website, http://www.sdss.org, provides links to the data, tutorials and examples of data access, and extensive documentation of the reduction and analysis procedures. DR13 is the first of a scheduled set that will contain new data and analyses from the planned ~6-year operations of SDSS-IV.PostprintPeer reviewe