Evaluación de bloques de concreto, sustituyendo parcialmente la arena por polvo de madera, Chota.

Se analizaron y evaluaron las propiedades de los agregados y bloques de concreto no portantes sustituyendo parcialmente la arena por polvo de madera en porcentajes de: 0%. 2.5%, 5%, 10% y 15%, obteniendo resistencias a la compresión mayores a la resistencia mínima que es de 20 kg /cm2. El diseño de mezla se realizó con el método de módulo de finura en el laboratorio “GSE”. Se vio las ventajas y desventajas de los resultados obtenidos, llegando a la conclusión que con el 15% se obtuvo los bloques deseados, los cuales son el 13% más livianos y su elaboración es de menor costo y cumplen con la resistencia indicada en la Norma RNE E.070.ÍNDICE DE CONTENIDOS I. INTRODUCCIÓN………………………...………………………………………1 1.1. Planteamiento del problema…………………………………………………......1 1.2. Formulación del problema……………………………………………………..1 1.3. Justificación de la investigación………………………………………………..4 1.4. Delimitación de la investigación………………………………………………..7 1.5. Limitaciones……………………………………………………………………..7 1.6. Objetivos………………………………………………………………………...8 1.6.1. Objetivo general……………………………………………………………..8 1.6.2. Objetivos específicos………………………………………………………..8 II. MARCO TEÓRICO ……………………………………………………………..9 2.1. Antecedentes de la investigación ……………………………………………….9 2.1.1. Antecedentes Internacionales………………………………………………..9 2.1.2. Antecedentes Nacionales…………………………………………………….10 2.1.3. Antecedentes Regionales…………………………………………………….12 2.2. Marco teórico…………………………………………………………………..13 2.3. Definición de términos………………………………………………………...43 III. PLANTEAMIENTO DE LA HIPÓTESIS Y VARIABLES………………...44 3.1. Hipótesis………………………………………………………………………..44 3.1.1. General………………………………………………………………………44 3.1.2. Especifica……………………………………………………………………44 3.2. Variables……………………………………………………………………….44 3.2.1. Variable independiente………………………………………………………44 3.2.2. Variable dependiente………………………………………………………..44 3.3. Operacionalización de variables……………………………………………..45 IV. MARCO METODOLÓGICO………………………………………………….46 4.1. Ubicación geográfica del estudio……………………………………………...46 4.2. Unidad de análisis, población y muestra …………………………………….46 4.2.1. Población ……………………………………………………………………46 4.2.2. Muestra………………………………………………………………………46 4.2.3. Unidad de análisis …………………………………………………………...47 4.3. Tipo y descripción del diseño de investigación ………………………………47 4.3.1. Tipo de investigación………………………………………………………...47 4.3.2. Diseño de investigación …………………………………………………….48 4.3.3. Métodos de investigación……………………………………………………50 4.4. Técnicas e instrumentos de recolección de datos……………………………50 4.5. Técnicas para el procesamiento y análisis de información …………………52 4.6. Matriz de consistencia metodológica…………………………………………52 V. RESULTADOS Y DISCUSIONES…………………………………………...55 5.1. Origen de los materiales utilizados……………………………………………..55 5.2. Análisis, interpretación y discusión de resultados………………………………59 5.3. Costos………………………………………………………………………….115 5.4. Contrastación de hipótesis……………………………………………………..119 CONCLUSIONES……………………………………………………………………121 RECOMENDACIONES……………………………………………………………..123 REFERENCIAS BIBLIOGRAFICAS………………………………………………124 ANEXOS……………

Are the health messages in schoolbooks based on scientific evidence? A descriptive study

<p>Abstract</p> <p>Background</p> <p>Most textbooks contains messages relating to health. This profuse information requires analysis with regards to the quality of such information. The objective was to identify the scientific evidence on which the health messages in textbooks are based.</p> <p>Methods</p> <p>The degree of evidence on which such messages are based was identified and the messages were subsequently classified into three categories: Messages with high, medium or low levels of evidence; Messages with an unknown level of evidence; and Messages with no known evidence.</p> <p>Results</p> <p>844 messages were studied. Of this total, 61% were classified as messages with an unknown level of evidence. Less than 15% fell into the category where the level of evidence was known and less than 6% were classified as possessing high levels of evidence. More than 70% of the messages relating to "Balanced Diets and Malnutrition", "Food Hygiene", "Tobacco", "Sexual behaviour and AIDS" and "Rest and ergonomics" are based on an unknown level of evidence. "Oral health" registered the highest percentage of messages based on a high level of evidence (37.5%), followed by "Pregnancy and newly born infants" (35%). Of the total, 24.6% are not based on any known evidence. Two of the messages appeared to contravene known evidence.</p> <p>Conclusion</p> <p>Many of the messages included in school textbooks are not based on scientific evidence. Standards must be established to facilitate the production of texts that include messages that are based on the best available evidence and which can improve children's health more effectively.</p

The Vein Patterning 1 (VEP1) Gene Family Laterally Spread through an Ecological Network

Lateral gene transfer (LGT) is a major evolutionary mechanism in prokaryotes. Knowledge about LGT— particularly, multicellular— eukaryotes has only recently started to accumulate. A widespread assumption sees the gene as the unit of LGT, largely because little is yet known about how LGT chances are affected by structural/functional features at the subgenic level. Here we trace the evolutionary trajectory of VEin Patterning 1, a novel gene family known to be essential for plant development and defense. At the subgenic level VEP1 encodes a dinucleotide-binding Rossmann-fold domain, in common with members of the short-chain dehydrogenase/reductase (SDR) protein family. We found: i) VEP1 likely originated in an aerobic, mesophilic and chemoorganotrophic α-proteobacterium, and was laterally propagated through nets of ecological interactions, including multiple LGTs between phylogenetically distant green plant/fungi-associated bacteria, and five independent LGTs to eukaryotes. Of these latest five transfers, three are ancient LGTs, implicating an ancestral fungus, the last common ancestor of land plants and an ancestral trebouxiophyte green alga, and two are recent LGTs to modern embryophytes. ii) VEP1's rampant LGT behavior was enabled by the robustness and broad utility of the dinucleotide-binding Rossmann-fold, which provided a platform for the evolution of two unprecedented departures from the canonical SDR catalytic triad. iii) The fate of VEP1 in eukaryotes has been different in different lineages, being ubiquitous and highly conserved in land plants, whereas fungi underwent multiple losses. And iv) VEP1-harboring bacteria include non-phytopathogenic and phytopathogenic symbionts which are non-randomly distributed with respect to the type of harbored VEP1 gene. Our findings suggest that VEP1 may have been instrumental for the evolutionary transition of green plants to land, and point to a LGT-mediated ‘Trojan Horse’ mechanism for the evolution of bacterial pathogenesis against plants. VEP1 may serve as tool for revealing microbial interactions in plant/fungi-associated environments

Parent-child interaction therapy for children with developmental delay and related problems

Young children with or at risk for developmental delay have been shown to be at significantly higher risk for behavior problems and other associated problems, including academic problems, peer problems, and parental stress. In recent years, intervention efforts targeting behavior problems have grown exponentially. Parent-child interaction therapy (PCIT) is an early behavioral parenting training intervention that has received increased research and clinical attention as studies have expanded to include children with developmental delay and related problems. In this chapter, we provide an overview of research studies over the past decade examining PCIT for children with developmental delay and related problems, such as intellectual disability, autism spectrum disorder, and conditions that increase risk for disability, such as premature birth and traumatic brain injury. Lastly, we provide a case example using PCIT for a 5-year-old African American female with elevated behavior problems following a moderate traumatic brain injury, and conclude with a summary of future directions for PCIT for children with or at risk for developmental delay