Bullying y rendimiento académico de los alumnos de educación secundaria de la I:E Santa Rosa de Lima Cabracancha- Chota 2015

El estudio titulado “Bullying y rendimiento académico de los alumnos de educación secundaria de la I. E. Santa Rosa de Lima Cabracancha – Chota, 2015” tuvo como objetivo determinar la relación entre bullying y rendimiento académico de los alumnos de educación secundaria. Estudio de enfoque cuantitativa, de tipo descriptiva, no experimental, diseño transversal y correlacional. La muestra estuvo conformada por 97 alumnos. Se utilizó un cuestionario de 12 preguntas sobre las características socioeconómicas y familiares, la escala índice global del bullying de Chávez, C y Delgado, F. (2013) y ficha de rendimiento académico. Como resultados tenemos que los alumnos se encuentran entre la edad de 12 a 14 años (47,4%), predominando las mujeres con el 52,6%, los grados de estudios con más altos porcentajes están primero, segundo y tercero con 22,7% respectivamente, el 44,3%, proceden del caserío de Cabracancha, pertenece a la religión católica (88,7%) y provienen de familias nucleares (73,2%), el 73,2% de los padres son casados, el 67% se dedican a la agricultura y tienen primaria incompleta (48,5%). En cuanto a las madres de los alumnos el 95,9% son amas de casa, el 50,5% tienen grado de instrucción primaria incompleta; el 68% de las familias cuentan con ingreso económico mensual menor de 750 soles. En cuanto al bullying el 99% sufren de bullying medio, el 1% sufre de bullying alto. Respecto al rendimiento académico el 39,2% se encontró en la categoría medio y el 1,0% en deficiente. Estos resultados permitieron contrastar la hipótesis nula que no existe relación entre el bullying y el rendimiento académico a un nivel de significancia del 5% con un valor p = 0.581. Se concluye que existe la presencia de bullying pero no hay relación con el rendimiento académico.Tesi

<i>Methanobacterium</i> Dominates Biocathodic Archaeal Communities in Methanogenic Microbial Electrolysis Cells

Methane is the primary end product from cathodic current in microbial electrolysis cells (MECs) in the absence of methanogenic inhibitors, but little is known about the archaeal communities that develop in these systems. MECs containing cathodes made from different materials (carbon brushes, or plain graphite blocks or blocks coated with carbon black and platinum, stainless steel, nickel, ferrihydrite, magnetite, iron sulfide, or molybdenum disulfide) were inoculated with anaerobic digester sludge and acclimated at a set potential of −600 mV (versus a standard hydrogen electrode). The archaeal communities on all cathodes, except those coated with platinum, were predominated by Methanobacterium (median 97% of archaea). Cathodes with platinum contained mainly archaea most similar to Methanobrevibacter. Neither of these methanogens were abundant (<0.1% of archaea) in the inoculum, and therefore their high abundance on the cathode resulted from selective enrichment. In contrast, bacterial communities on the cathode were more diverse, containing primarily δ-Proteobacteria (41% of bacteria). The lack of a consistent bacterial genus on the cathodes indicated that there was no similarly selective enrichment of bacteria on the cathode. These results suggest that the genus Methanobacterium was primarily responsible for methane production in MECs when cathodes lack efficient catalysts for hydrogen gas evolution

Comparison of Nonprecious Metal Cathode Materials for Methane Production by Electromethanogenesis

In methanogenic microbial electrolysis cells (MMCs), CO₂ is reduced to methane using a methanogenic biofilm on the cathode by either direct electron transfer or evolved hydrogen. To optimize methane generation, we examined several cathode materials: plain graphite blocks, graphite blocks coated with carbon black or carbon black containing metals (platinum, stainless steel or nickel) or insoluble minerals (ferrihydrite, magnetite, iron sulfide, or molybdenum disulfide), and carbon fiber brushes. Assuming a stoichiometric ratio of hydrogen (abiotic):methane (biotic) of 4:1, methane production with platinum could be explained solely by hydrogen production. For most other materials, however, abiotic hydrogen production rates were insufficient to explain methane production. At −600 mV, platinum on carbon black had the highest abiotic hydrogen gas formation rate (1600 ± 200 nmol cm^–3 d^–1) and the highest biotic methane production rate (250 ± 90 nmol cm^–3 d^–1). At −550 mV, plain graphite (76 nmol cm^–3 d^–1) performed similarly to platinum (73 nmol cm^–3 d^–1). Coulombic recoveries, based on the measured current and evolved gas, were initially greater than 100% for all materials except platinum, suggesting that cathodic corrosion also contributed to electromethanogenic gas production

Fermentation couples Chloroflexi and sulfate-reducing bacteria to Cyanobacteria in hypersaline microbial mats

Past studies of hydrogen cycling in hypersaline microbial mats have shown an active nighttime cycle, with production largely from Cyanobacteria and consumption from sulfate-reducing bacteria (SRB). However, the mechanisms and magnitude of hydrogen cycling have not been extensively studied. Two mats types near Guerrero Negro, Mexico -- permanently submerged Microcoleus microbial mats (GN-S), and intertidal Lyngbya microbial mats (GN-I) -- were used in microcosm diel manipulation experiments with 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU), molybdate, ammonium addition, and physical disruption to understand the processes responsible for hydrogen cycling between mat microbes. Across microcosms, H2 production occurred under dark anoxic conditions with simultaneous production of a suite of organic acids. H2 production was not significantly affected by inhibition of nitrogen fixation, but rather appears to result from constitutive fermentation of photosynthetic storage products by oxygenic phototrophs. Comparison to accumulated glycogen and to CO2 flux indicated that, in the GN-I mat, fermentation released almost all of the carbon fixed via photosynthesis during the preceding day, primarily as organic acids. Across mats, although oxygenic and anoxygenic phototrophs were detected, cyanobacterial [NiFe]-hydrogenase transcripts predominated. Molybdate inhibition experiments indicated that SRBs from a wide distribution of dsrA phylotypes were responsible for H2 consumption. Incubation with 13C-acetate and nanoSIMS (secondary ion mass-spectrometry) indicated higher uptake in both Chloroflexi and SRBs relative to other filamentous bacteria. These manipulations and diel incubations confirm that Cyanobacteria were the main fermenters in Guerrero Negro mats and that the net flux of nighttime fermentation byproducts (not only hydrogen) was largely regulated by the interplay between Cyanobacteria, SRBs, and Chloroflexi

The NASA Astrobiology Roadmap

The NASA Astrobiology Roadmap provides guidance for research and technology development across the NASA enterprises that encompass the space, Earth, and biological sciences. The ongoing development of astrobiology roadmaps embodies the contributions of diverse scientists and technologists from government, universities, and private institutions. The Roadmap addresses three basic questions: How does life begin and evolve, does life exist elsewhere in the universe, and what is the future of life on Earth and beyond? Seven Science Goals outline the following key domains of investigation: understanding the nature and distribution of habitable environments in the universe, exploring for habitable environments and life in our own solar system, understanding the emergence of life, determining how early life on Earth interacted and evolved with its changing environment, understanding the evolutionary mechanisms and environmental limits of life, determining the principles that will shape life in the future, and recognizing signatures of life on other worlds and on early Earth. For each of these goals, Science Objectives outline more specific high-priority efforts for the next 3-5 years. These 18 objectives are being integrated with NASA strategic planning.Organismic and Evolutionary Biolog

12. Februar 1917

Stadtarchiv Solingen, Bergische Arbeiterstimme 12. Februar 1917 Die Geschäftsleitung der „Freien Presse“ in Elberfeld setzt ein neue Redaktion ein. Damit wird aus dem Organ der Minderheit eine Zeitung der Mehrheitssozialdemokratie              Aus der Partei.              Die „Freie Presse“.    An der Spitze der „Freien Presse“ in Elberfeld lesen wir folgendes:                       An unsere Leser!    Der Kriegszustand und seine Begleiterscheinungen bringen, wie für fast alle Staatsbür..