452 research outputs found

    Information and communication technology (ICT) skills and job satisfaction of primary education teachers in the context of Covid-19. Theoretical model

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    The Covid-19 pandemic has shown that educational systems must have an online component or even a substitute. However, the efforts for this necessary transition fall largely on the teaching staff, who have been forced to quickly adapt their activities to a virtual environment. In this study, a theoretical model for analyzing how teachers’ information and communications technology (ICT) skills and the integration of these technologies influence the improvement of teaching and teacher job satisfaction is introduced. The model also pays special attention to the gender gap related to the use of ICT in teaching. At the empirical level, the model is validated on a sample of 257 Spanish primary school teachers, using the partial least squares (PLS) structural equation method. The results of the analysis show that, although the teachers’ ICT skills help them improve their teaching activities, such skills do not have a direct impact on teachers’ job satisfaction. However, teachers who integrate ICTs into their teaching activities not only improve their results and lighten their workload but also enjoy higher job satisfaction, which translates into more motivated and committed teachers. In addition, teachers’ ICT skills influence job satisfaction in different ways depending on gender. Although, for female teachers, the integration of ICT increases their job satisfaction, the results show that, for male teachers, this integration should generate improvements in teaching to yield enhanced job satisfaction. As the main implication, it is recommended to invest in teachers’ ICT skills, as these lead to enhanced efficiency and motivation and enable the change toward an ICT-based teaching model.

    Planeamiento tributario y la rentabilidad en empresas de servicios de carpintería en los olivos periodo 2017

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    Este proyecto de investigación tiene como objetivo determinar de qué manera el planeamiento tributario tiene relación con la rentabilidad en las empresas de servicios del sector carpintería en los olivos periodo 2017. Este estudio es de total importancia para la necesidad de las empresas de servicio, de manera que se pueda evitar caer en multas o infracciones tributarias y que estas ocasionen pérdidas que podrían provocar inestabilidad en la empresa. Este sector empresarial por lo general presenta estos tipos de problemas. El tipo de investigación es básico de nivel correlacional, diseño no experimental y el método fue hipotético deductivo. La población estuvo conformada por 40 trabajadores de las 8 empresas de servicios de carpintería registradas en la jurisdicción de los olivos, por lo tanto, se aplicó una fórmula para determinar la muestra, la cual fue de 36 colaboradores. La técnica que se utilizó en esta investigación fue la encuesta, así como también el instrumento de recolección de datos, que es el cuestionario, contando con un total de 15 ítems formulados por cada variable. Con un total de 30 ítems que fueron aplicados a los colaboradores de las empresas. Para la validación de los instrumentos se realizó bajo el criterio juicio de expertos, lo cual se validó mediante 3 expertos de la materia. La confiabilidad se basó en la prueba del Alpha de Crombach. La comprobación de las hipótesis se realizó con la prueba Rho de Spearman y la realización del análisis de datos se realizó mediante la estadística descriptiva (tablas y gráficos). En el presente trabajo de investigación se llegó a la conclusión que el planeamiento tributario tiene relación con la rentabilidad en empresas de servicio de carpintería del distrito de los olivos, año 201

    A technical evaluation, performance analysis and risk assessment of multiple novel oxy-turbine power cycles with complete CO2 capture

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    In recent years there has been growing concern about greenhouse gas emissions (particularly CO2 emissions) and global warming. Oxyfuel combustion is one of the key technologies for tackling CO2 emissions in the power industry and reducing their contribution to global warming. The technology involves burning fuel with high-purity oxygen to generate mainly CO2 and steam, enabling easy CO2 separation from the flue gases by steam condensation. In fact, 100% CO2 capture and near-zero NOx emissions can be achieved with this technology. This study examines nineteen different oxy-turbine cycles, identifying the main parameters regarding their operation and development. It also analyses the use of advanced natural gas (NG) combustion cycles from the point of view of the carbon capture and storage (CCS) and considering political, legislative and social aspects of deploying this technology. Six oxy-turbine cycles which are at the most advanced stages of development (NetPower, Clean Energy Systems CES), Modified Graz, E-MATIANT, Advanced Zero Emission Power AZEP 100% and Semi-Closed Oxy-fuel Combustion Combined Cycle (SCOC-CC)), were chosen to conduct a Political, Environmental, Social, Technological, Legislative and Economic (PESTLE) risk analysis. This compares each technology with a conventional combined cycle gas turbine (CCGT) power plant without carbon capture as the base-case scenario. Overall, the net efficiency of the different oxy-turbine cycles ranges between 43.6% and 65%, comparable to a CCGT power plant, while providing the extra benefits of CO2 capture and lower emissions. A multi-criteria analysis carried out using DECERNS (Decision Evaluation in Complex Risk Network Systems) software determined that, depending on the specific criterion considered, one can draw different conclusions. However, in terms of technology, environment and social opinion, the most promising cycles are the NetPower and CES cycles, whereas from an economic point of view, E-MATIANT is more competitive in the energy market. Giving each factor equal importance, the NetPower cycle must be considered to be the best oxy-turbine cycle based on our analysis. Most of the oxy-turbine cycles are still under development and only a few cycles (e.g., CES and NetPower) are progressing to the demonstration phase. In consequence, political measures such as CO2 tax and emission allowances need to be implemented for oxy-turbine technologies to become the preferred option for fossil fuel power plants burning natural gas

    Microbial community changes induced by Managed Aquifer Recharge activities: linking hydrogeological and biological processes

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    Managed Aquifer Recharge (MAR) is a technique used worldwide to increase the availability of water resources. We study how MAR modifies microbial ecosystems and its implications for enhancing biodegradation processes to eventually improve groundwater quality. We compare soil and groundwater samples taken from a MAR facility located in NE Spain during recharge (with the facility operating continuously for several months) and after 4 months of no recharge. The study demonstrates a strong correlation between soil and water microbial prints with respect to sampling location along the mapped infiltration path. In particular, managed recharge practices disrupt groundwater ecosystems by modifying diversity indices and the composition of microbial communities, indicating that infiltration favors the growth of certain populations. Analysis of the genetic profiles showed the presence of nine different bacterial phyla in the facility, revealing high biological diversity at the highest taxonomic range. In fact, the microbial population patterns under recharge conditions agree with the intermediate disturbance hypothesis (IDH). Moreover, DNA sequence analysis of excised denaturing gradient gel electrophoresis (DGGE) band patterns revealed the existence of indicator species linked to MAR, most notably Dehalogenimonas sp., Nitrospira sp. and Vogesella sp.. Our real facility multidisciplinary study (hydrological, geochemical and microbial), involving soil and groundwater samples, indicates that MAR is a naturally based, passive and efficient technique with broad implications for the biodegradation of pollutants dissolved in water.</p

    Lindane and Endosulfan Sulfate Isomers in Crassostrea virginica (Gmelin, 1791) Oyster Populations in Lagoon Systems from Central Gulf of Mexico

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    The aim of this study was to determine Lindane and Endosulfan Sulfate isomers in Crassostrea virginica oyster populations (Gmelin, 1791) in the Mandinga and Alvarado lagoon systems located in the central Gulf of Mexico. Samples were taken from the main oyster banks of each lagoon system, during the three representative seasons of the region, wet, dry and north winds. By means of free diving, 30 commercial size oysters (7 ± 3 cm) were collected in four oyster banks or stations of the Mandinga lagoon system, totaling 360 organisms, while in the Alvarado lagoon system there were a total of 90 oysters during the annual cycle. Concentration of lindane and endosulfan sulfate isotopes in C. virginica was performed with a gas chromatograph (Thermo Electron Model Trace GC Ultra 115V, Thermo Fisher Scientific Inc©, Monterrey, Nuevo León, México) with an Electron capture detector. Results showed that in the Alvarado Lagoon system mean concentrations of C. virginica oysters for lindane pesticide were 4.11 ± 3.83 ng⋅g-1, whereas for the Mandinga lagoon system, were 8.69 ± 5.15 ng⋅g-1. Endosulfan sulfate showed the highest average concentration in the Mandinga lagoon system with 24.68 ± 1.20 ng ⋅g-1. In addition, the endosulfan sulfate presents differences in its spatial distribution; high concentration levels in the Mandinga lagoon system whereas the lindane heterogeneity at all sampling points in both lagoons. Values of concentrations and relationships between compounds suggest recent contributions that could correspond to the excessive fluctuations of water discharged into the lagoon caused by the atypical rains of the year of sampling. It was concluded that endosulfan sulfate and lindane show concentration in all the points of sampling in both lagoons

    Serotypes and Stx2 subtyping of Shiga toxin producing Escherichia coli isolates from cattle carcasses and feces

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    ArticuloShiga toxin E. coli (STEC) is an important pathogen responsible for foodborne illness, this have been related with epidemic outbreaks in the past, mainly because of consumption of bovine meat. The objective of this study was identify the serotypes and Stx2 subtypes and associate them with their possible epidemiology. There were analyzed a total of 65 isolates from the collection of the Centro de Investigación y Estudios Avanzados en Salud Animal, Facultad de Medicina Veterinaria y Zootecnia of the Universidad Autónoma del Estado de México, from carcasses and feces of bovines at three different Municipal slaughterhouses. The identification of Stx2 gene by PCR at final point, sequencing and analyzed with the help of BLAST software. There were found O157:H7, O70:H16, O91:H10, O112ac:H2, O128ac:H26 serotypes, which have been reported to be present at infectious outbreaks previously by foodborne worldwide; 63.07% (41/65) of the Escherichia coli strains got amplified for Stx2 and after BLAS analysis it was confirmed its presence and a hypothetic protein. The presence of this serotypes in combination with different subtype’s, Stx2a, Stx2c, Stx2d, in carcasses and feces of bovine in must be considered as a potential risk for diseases an important problem of the public health

    Real-world evidence of tisagenlecleucel for the treatment of relapsed or refractory large B-cell lymphoma

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    Recerca clínica del càncer; Càncer hematològic; Limfoma no HodgkinInvestigación clínica del cáncer; Cáncer hematológico; Linfoma no HodgkinClinical cancer research; Hematological cancer; Non-Hodgkin's lymphomaTisagenlecleucel (tisa-cel) is a second-generation autologous CD19-targeted chimeric antigen receptor (CAR) T-cell therapy approved for relapsed/refractory (R/R) large B-cell lymphoma (LBCL). The approval was based on the results of phase II JULIET trial, with a best overall response rate (ORR) and complete response (CR) rate in infused patients of 52% and 40%, respectively. We report outcomes with tisa-cel in the standard-of-care (SOC) setting for R/R LBCL. Data from all patients with R/R LBCL who underwent leukapheresis from December 2018 until June 2020 with the intent to receive SOC tisa-cel were retrospectively collected at 10 Spanish institutions. Toxicities were graded according to ASTCT criteria and responses were assessed as per Lugano 2014 classification. Of 91 patients who underwent leukapheresis, 75 (82%) received tisa-cel therapy. Grade 3 or higher cytokine release syndrome and neurotoxicity occurred in 5% and 1%, respectively; non-relapse mortality was 4%. Among the infused patients, best ORR and CR were 60% and 32%, respectively, with a median duration of response of 8.9 months. With a median follow-up of 14.1 months from CAR T-cell infusion, median progression-free survival and overall survival were 3 months and 10.7 months, respectively. At 12 months, patients in CR at first disease evaluation had a PFS of 87% and OS of 93%. Patients with an elevated lactate dehydrogenase showed a shorter PFS and OS on multivariate analysis. Treatment with tisa-cel for patients with relapsed/refractory LBCL in a European SOC setting showed a manageable safety profile and durable complete responses

    GRAVITY Spectro-interferometric Study of the Massive Multiple Stellar System HD 93206 A

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    Characterization of the dynamics of massive star systems and the astrophysical properties of the interacting components are a prerequisite for understanding their formation and evolution. Optical interferometry at milliarcsecond resolution is a key observing technique for resolving high-mass multiple compact systems. Here, we report on Very Large Telescope Interferometer/GRAVITY, Magellan/Folded-port InfraRed Echellette, and MPG2.2 m/FEROS observations of the late-O/early-B type system HD 93206 A, which is a member of the massive cluster Collinder 228 in the Carina nebula complex. With a total mass of about 90 M⊙90\,{M}_{\odot }, it is one of the most compact massive quadruple systems known. In addition to measuring the separation and position angle of the outer binary Aa–Ac, we observe Brγ and He i variability in phase with the orbital motion of the two inner binaries. From the differential phase (Δϕ{{\rm{\Delta }}}_{\phi }) analysis, we conclude that the Brγ emission arises from the interaction regions within the components of the individual binaries, which is consistent with previous models for the X-ray emission of the system based on wind–wind interaction. With an average 3σ deviation of Δϕ∼15∘{{\rm{\Delta }}}_{\phi }\sim 15^\circ , we establish an upper limit of p ~ 0.157 mas (0.35 au) for the size of the Brγ line-emitting region. Future interferometric observations with GRAVITY using the 8 m Unit Telescopes will allow us to constrain the line-emitting regions down to angular sizes of 20 μas (0.05 au at the distance of the Carina nebula)

    Pesquería artesanal de elasmobranquios en la costa Pacifico de Baja California Sur, México, implicaciones para su gestión

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    Artisanal fisheries in Mexico account for approximately 40% of the total national catch. In 2009, Baja California Sur (BCS) had the second largest catch of elasmobranchs on the Mexican Pacific coast. This paper characterizes and describes the artisanal elasmobranch fishery of Pacific coast of BCS from 2000 to 2010. Sixty artisanal camps were documented, of which 45 targeted elasmobranchs, using primarily gillnets and longlines. We identified 52 elasmobranch species. Gillnetting accounted for 73.5% of the fishing effort and most frequently captured Rhinobatos productus, Mustelus henlei and Myliobatis californica. Longline fishing accounted for 26.5% of effort, most frequently capturing Prionace glauca and Isurus oxyrinchus. The prevalence of juveniles of several species (e.g., Cephaloscyllium ventriosum, Galeorhinus galeus, Isurus oxyrinchus, and Myliobatis californica) within landings suggests that fishing effort may be opportunistically directed at breeding or nursery areas. Despite the dominance of species with wide distributions, we observed a significant biogeographic pattern in the abundance of some species relative to Bahia Magdalena. Results of the present study will be useful to detect changes in the structure of commercially exploited elasmobranch populations, and to provide useful indications for management purposes.La pesquería artesanal en México soporta aproximadamente el 40% de la captura total nacional. En 2009 Baja California Sur (BCS) fue el segundo estado con mayor registro de captura de elasmobranquios de todo el Pacifico Mexicano. En el presente trabajo se realizó la caracterización y descripción de la pesquería artesanal de elasmobranquios en la costa Pacífico de BCS del 2000 al 2010. Se registraron 60 campos artesanales, de los cuales en 45 se capturaron elasmobranquios usando como artes de pesca redes y palangres. Se identificaron 52 especies de elasmobranquios. Las redes representaron el 73.5% del esfuerzo pesquero, las especies que se capturaron con mayor frecuencia fueron Rhinobatos productus, Mustelus henlei y Myliobatis californica. Por otra parte los palangres representaron el 26.5% del esfuerzo pesquero, las especies capturadas con mayor frecuencia fueron, Prionace glauca e Isurus oxyrinchus. La presencia de especímenes juveniles de varias especies en los desembarques (p. ej. Cephaloscyllium ventriosum, Galeorhinus galeus, Isurus oxyrinchus, Myliobatis californica) sugiere que el esfuerzo pesquero podría ser oportunista dirigido a las zonas de crianza o de reproducción. A pesar del dominio de especies con distribuciones amplias, se observó un patrón biogeográfico significativo en la abundancia de algunas especies al sur y al norte de Bahía Magdalena. Los resultados del presente estudio serán de utilidad para poder detectar los posibles cambios en la estructura poblacional de los elasmobranquios explotados comercialmente
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