954 research outputs found
Development and characterization of nettle-leaves powder (Urtica urens) as a potential supplement for animal feed
Nettle plants in Chile are an underutilized resource. Its use in animal nutrition is also limited. In addition, information about its composition (specifically fatty acids and aminoacids) is scarce. The objective of this work was to develop and characterize nettle-leaves powder (NP). This powder was characterized by means of proximate chemical analysis. Its concentration of minerals, and composition profiles for fatty acids andaminoacids, was determined. NP showed high dry basis content of proteins (24%) and nitrogen-free extract (32%), whereas crude fiber concentration was low (8.4%). Also, NP showed high concentrations of ash (29%), and mineral, specially for calcium (1.65%) and zinc (20 mg/100g of NP). Additionally, glutamic and aspartic acids, as well as leucine, were the major types of aminoacids found in NP. In conclusion, though nettleplants are an under-utilized resource, the elevated content of protein found in powders prepared from their leaves might become a compelling reason to include them as a protein supplement in animal diets.
Highlights
Potential supplement for animal feed from nettle-leaves (Urtica urens).
Re-use of a weed by a simple process of drying and grinding.
The high content of proteins and minerals such as calcium and zinc.
Amino acid profile with a high content of glutamic and aspartic acids, leucine and proline.
Fatty acid profile with a predominance of polyunsaturated fatty acids, such as α linolenic and linoleic acids.Nettle plants in Chile are an underutilized resource. Its use in animal nutrition is also limited. In addition, information about its composition (specifically fatty acids and aminoacids) is scarce. The objective of this work was to develop and characterize nettle-leaves powder (NP). This powder was characterized by means of proximate chemical analysis. Its concentration of minerals, and composition profiles for fatty acids andaminoacids, was determined. NP showed high dry basis content of proteins (24%) and nitrogen-free extract (32%), whereas crude fiber concentration was low (8.4%). Also, NP showed high concentrations of ash (29%), and mineral, specially for calcium (1.65%) and zinc (20 mg/100g of NP). Additionally, glutamic and aspartic acids, as well as leucine, were the major types of aminoacids found in NP. In conclusion, though nettleplants are an under-utilized resource, the elevated content of protein found in powders prepared from their leaves might become a compelling reason to include them as a protein supplement in animal diets.
Highlights
Potential supplement for animal feed from nettle-leaves (Urtica urens).
Re-use of a weed by a simple process of drying and grinding.
The high content of proteins and minerals such as calcium and zinc.
Amino acid profile with a high content of glutamic and aspartic acids, leucine and proline.
Fatty acid profile with a predominance of polyunsaturated fatty acids, such as α linolenic and linoleic acids
Implementación de una PMO en una empresa de tecnologÃa: un análisis comparativo de metodologÃas de proyectos
En este artÃculo se analizan tres modelos de administración de proyectos que han sido exitosos en su implantación particular en proyectos de TecnologÃas de Información y Comunicación (TIC) 1. De manera puntual, se revisaron las implicaciones de las visiones que contemplan tres metodologÃas de Gerencia de Proyectos (GP) y se presenta una comparación de sus caracterÃsticas, identificando como contribuyen al desempeño de una Oficina de Administración de Proyectos (Project Management Office, PMO) en una empresa de outsourcing de servicios de tecnologÃa, con el fin de establecer cuál es la más apropiada y finalmente resumir que su fusión es optima para generar valor como proveedor de servicios de tecnologÃa y comunicaciones.This article analyzes three Project Management models that have been successful in their particular execution on ICT projects. Particularly, the authors make an implication assessment of the three methodologies and present a comparison of their characteristics, looking forward to identify how they contribute to the performance of a Project Management Office (PMO), in the context of a technology services outsourcing company. All of this, to realize which method is the best, and then conclude that their mix is an optimal alternative to create value as a provider of technology services and communications
Detection of human immunodeficiency virus RNAs in living cells using Spinach RNA aptamers
Many techniques currently used to measure HIV RNA production in cells suffer from limitations that include high background signal or the potential to destroy cellular context. Fluorophore-binding RNA aptamers offer the potential for visualizing RNAs directly in living cells with minimal cellular perturbation. We inserted a sequence encoding a fluorophore-binding RNA aptamer, known as Spinach, into the HIV genome such that predicted RNA secondary structures in both Spinach and HIV were preserved. Chimeric HIV-Spinach RNAs were functionally validated in vitro by testing their ability to enhance the fluorescence of a conditional fluorophore (DFHBI), which specifically binds Spinach. Fluorescence microscopy and PCR were used to verify expression of HIV-Spinach RNAs in human cells. HIV-1 gag RNA production and fluorescence were measured by qPCR and fluorometry, respectively. HIV-Spinach RNAs were fluorometrically detectable in vitro and were transcribed in human cell lines and primary cells, with both spliced and unspliced species detected by PCR. HIV-Spinach RNAs were visible by fluorescence microscopy in living cells, although signal was reproducibly weak. Cells expressing HIV-Spinach RNAs were capable of producing fluorometrically detectable virions, although detection of single viral particles was not possible. In summary, we have investigated a novel method for detecting HIV RNAs in living cells using the Spinach RNA aptamer. Despite the limitations of the present aptamer/fluorophore combination, this is the first application of this technology to an infectious disease and provides a foundation for future research into improved methods for studying HIV expression
Caracterizacion del comportamiento pragmatico en aspectos no verbales de ninos con mielomeningocele que asisten al Instituto de Rehabilitacion Infantil Teleton del Maule en distintas situaciones comunicativas.
52 p.El propósito de este trabajo es estudiar si existen diferencias significativas en el comportamiento pragmático en los aspectos no verbales en niños con mielomeningocele entre 7 y 14 años que asisten al Instituto de Rehabilitación Infantil Teletón del Maule en diferentes situaciones comunicativas. Esto se logrará mediante la utilización del Protocolo Pragmático Simplificado de Carol Prutting y Diane Kirchner (1987). Los resultados obtenidos en esta investigación demuestran que existen diferencias significativas en el comportamiento pragmático no verbal entre las diferentes situaciones comunicativas estudiadas. Esto significa que los niños con mielomeningocele entre 7 y 14 años la mayor parte del tiempo varÃan su comportamiento pragmático no verbal al comunicarse de manera verbal en diferentes situaciones comunicativas (con niños de su edad, con adultos y con algún familiar)
Propiedades psicométricas de los módulos semántico y pragmático de la baterÃa de lenguaje objetiva y criterial screening (bloc–s) en sujetos con sÃndrome de Down, deficiencia mental leve y sÃndrome de asperger.
81 p.El objetivo de este estudio fue analizar las propiedades psicométricas de la BLOC-S en sus módulos semántico y pragmático. En una muestra de 80 niños con SÃndrome de Down, SÃndrome de Asperger y Deficiencia Mental Leve. Los niveles de confiabilidad fueron de 0,94 para los módulos de semántica y pragmática. Un análisis factorial exploratorio de los bloques que constituyen cada módulo, produjo una solución básicamente unidimensional que explica el 45,78% de la varianza. Un análisis discriminante que clasifica correctamente al 76,3% y 77,5% de la totalidad de los sujetos de la muestra, para los módulos de semántica y
pragmática respectivamente. Asà también un análisis discriminante de los factores
que clasifica al 80%, 70%, 52,5% y 70% de la totalidad de la muestra, para los
factores 1, 2, 3 y 4 respectivamente. No se encontraron diferencias por sexo al
interior de cada grupo. Al realizar comparaciones entre los grupos se observa un
bajo rendimiento en los sujetos con SÃndrome de Down comparado con los sujetos con SÃndrome de Asperger y Deficiencia Mental Leve. Al comparar estos últimos dos grupos entre sà los rendimientos en los módulos de semántica y pragmática son muy similares. Lo anterior podrÃa ser explicado debido a que los sujetos con SÃndrome de Asperger constituÃan una muestra muy pequeña y además sus edades eran inferiores a los sujetos con Deficiencia Mental Leve
Caracterizacion del comportamiento pragmatico en aspectos verbales de ninos con mielomeningocele que asisten al instituto de rehabilitacion infantil Teleton del Maule en distintas situaciones comunicativas
62 p.El propósito de este trabajo es estudiar si existen diferencias pragmáticas significativas en niños con mielomeningocele entre 7 y 14 años que asisten al Instituto Infantil de Rehabilitación del Maule en diferentes situaciones comunicativas. Los análisis se realizan con el Protocolo Pragmático Simplificado de Carol Prutting y Diane Kirchner (1987). Los resultados demuestran que existen diferencias significativas en el comportamiento pragmático paralingüÃstico entre las diferentes situaciones comunicativas estudiadas. Esto significarÃa que los niños con mielomeningocele entre 7 y 14 años la mayor parte del tiempo varÃan su comportamiento pragmático paralingüÃstico al comunicarse de manera verbal en diferentes situaciones comunicativas (con niños de su edad, con adultos y con algún familiar
Efecto de la infusión de manzanilla sobre el ph, capacidad buffer y flujo salival in vivo
81 p.INTRODUCCIÓN: La manzanilla, es uno de los ingredientes más populares de los tés de hierbas, a ella se le atribuyen muchas propiedades beneficiosas para la salud principalmente antiinflamatorias, cicatrizantes y antiespasmódicas e incluso
ha sido incorporada en enjuagues bucales y pastas dentales. La saliva es un factor determinante de la salud oral que puede desempeñar un papel importante en la prevención de caries. Un apropiado flujo salival es esencial, la tasa de flujo
es, sin duda, el parámetro más importante, ya que la actividad o la eficacia cariostática de prácticamente todos los demás parámetros salivales dependen de
ella.
OBJETIVO: Determinar el efecto de la infusión de manzanilla sobre el pH,
capacidad buffer y flujo salival en sujetos con bajo riesgo cariogénico. MATERIALES y MÉTODOS: La muestra fue de 37 sujetos sanos con bajo riesgo cariogénico, en ella se determinó el flujo salival (ml/min), se midió pH con un potenciómetro (PL-600Lab PH meter) y capacidad buffer según método de
Ericsson para saliva no estimulada de tres muestras de saliva de cada sujeto
correspondientes a: saliva basal, post-ingesta de agua y post-ingesta de infusión
de manzanilla (Club®, a 50°C y sin endulzantes). Los resultados obtenidos fueron
analizados mediante la prueba estadÃstica de Friedman, con software SPSS 15.0.
RESULTADOS: Al comparar las medias de flujo salival basal, post-ingesta de agua y post-ingesta de Manzanilla (0,51 / 0,33 / 0,57 ml/min.) se observa que la Manzanilla y el flujo basal no presentan diferencias significativas, mientras el agua sà desciende la tasa de flujo salival. En cuanto al pH de las muestras de saliva basal, post-ingesta de agua y post-ingesta de Manzanilla (7.21 / 7.14 / 7.23) son similares no existiendo diferencias significativas entre ellas. Con respecto a la capacidad buffer, las medias basal, post-ingesta de agua y post-ingesta de
Manzanilla (4.93 / 4.19 / 5), se observa que la ingesta de Manzanilla aumenta la
capacidad buffer mas no significativamente en relación a la basal, mientras el agua desciende significativamente la capacidad buffer en comparación a las otras
dos muestras.
CONCLUSIÓN: La manzanilla conserva los niveles basales de pH, capacidad buffer y flujo salival. Palabras clave: pH salival, capacidad buffer, flujo salival, Manzanill
Phosphate Reactions as Mechanisms of High-Temperature Lubrication
One of the major problems preventing the operation of advanced gas turbine engines at higher temperatures is the inability of currently used liquid lubricants to survive at these higher temperatures under friction and wear conditions. Current state-of-the-art organic liquid lubricants rapidly degrade at temperatures above 300 C; hence some other form of lubrication is necessary. Vapor-phase lubrication is a promising new technology for high-temperature lubrication. This lubrication method employs a liquid phosphate ester that is vaporized and delivered to bearings or gears; the vapor reacts with the metal surfaces, generating a solid lubricious film that has proven very stable at high temperatures. In this study, solid lubricious films were grown on cast-iron foils in order to obtain reaction and diffusion rate data to help characterize the growth mechanism. A phenomenological mathematical model of the film deposition process was derived incorporating transport and kinetic parameters that were coupled to the experimental data. This phenomenological model can now be reliably used as a predictive and scale-up tool for future vapor-phase lubrication studies
Exploring the effect of social media in Personal Learning Environments in the university settings: analysing experiences and detecting future challenges
The concept of PLEs as connected learning and the shaping of them as a socio-material framework in which people learn, overlaps with the intrinsic characteristics of social media. Consequently, it is important to analyse how academic literature has treated the direct relationship between the two realities in the university sector. Accordingly, the objective of this work is to determine how this relationship has been treated with regards to contexts, authorship and positions, types of social media, objectives pursued, methodologies and results. Regarding methodology, we used the PICOC strategy to design the research questions and the PRISMA protocol to document the systematic review of academic production in SCOPUS and Web of Science between 2012 and 2021. We ultimately obtained a sample of 35 works. The findings show that use of media to build PLEs that meet users’ needs should be explored in greater depth and analysed by using particular methodologies to reach conclusions that help to drive them. Academic and professional promotion stand out among the major challenges in the use of social media in PLEs, as does the possibility of bringing together non-formal, formal, and informal areas to create learning
- …