214 research outputs found
Biodiesel: a critical overview on the current status and perspectives at the academy and industry
This article presents a bibliographic review of research carried out on different alternative processes for biodiesel production. The supercritical and subcritical (non catalytic) reaction conditions, the use of solid basic, solid acid and other heterogeneous catalysts, including the use of immobilized enzymes and whole-cell catalysts are also critically compared with the traditional homogeneous alkaline or acid catalysts that are common on industrial applications. Advantages and limitations of all these processes for the transference from the laboratory to the industry are discussed. A correlation of the chemical composition with the quality parameters of the produced biodiesel is done with aim to stablish adequate procedures for the right selection of the raw-material. Castor bean oil is used as an example of inappropriate oil in order to produce a B100 that fulfill all the international physico-chemical quality standards. In this article are presented research results to adequate the values of viscosity, density and iodine number of the castor and soybean biodiesel to the international standard limits by means blending these both biodiesels at the right ratio
An exploratory Delphy study on Character Education in Latin-American countries: Argentina, Colombia and Mexico
En el proyecto Researching and Promoting Character Education in Latin American Secondary Schools, financiado por la Templeton World Charity Foundation, nos aproximamos a la percepción que de la Educación del Carácter se tiene en Argentina, Colombia y México. La Educación del Carácter integra las propuestas para promover la ciudadanía.
Para el inicio de esta investigación elaboramos un estudio piloto basándonos en la metodología Dephi, con el objetivo de discernir cuáles son los temas más candentes alrededor de la Educación del Carácter en estos países. Esta metodología -rigurosa y de fácil manejo- permite la obtención de un conocimiento en profundidad sobre la problemática de la Educación del Carácter.
Contamos con la participación de diferentes expertos del ámbito académico, escolar y administrativo. Durante el proceso realizamos tres interacciones con los expertos para alcanzar un mayor consenso en sus opiniones. Para ello aplicamos dos rondas de preguntas cerradas y abiertas con las que obtener una mayor riqueza y convergencia en los datos obtenidos.
Como resultado constatamos que la Educación del Carácter no es un término habitual en el ámbito educativo de estos países. Además, en este tipo de educación incide la influencia y relación entre los agentes y el currículum explícito-oculto en la escuela
Reflections on an educational program on moral and civic virtues and values in secondary schools. A case study in Mexico.
The research we present is part of the project Researching and Promoting Character Education in Latin American Secondary Schools funded by the Templeton World Charity Foundation.In this research work we present a case study, focusing on the values program implemented in a Mexican public school in the central area of the country. Our exploration of the capacity of the school when implementing the values program is based on the analysis of documents provided by the school which are related with the project, semi-structured interviews, in-depth interviews, images and the participatory observation carried out in the school over a period of three weeks. The wealth of informants (principals, teachers, pupils and parents) allowed us to gather a broader variety of information on the reality of the values program applied
Interpretation of Principal Components
The principal component analysis can be carried out two ways. First the R-mode:
R = K\u27K
and the second is the Q-mode:
Q = K K\u27
where K is a data matrix centered by column or by row. The most commonly used method is the R-mode.
It has been suggested that principal components computed from either the R-mode or the Q-mode may have the same interpretation. If this is true, then interpretation of the principal components could be put on a much more intuitive level in many applications. This will occur whenever one type of principal component is more intuitively related to the physical or natural system being studied than the other.
The relationship between the principal components of the R-mode and the Q-mode have been investigated with the result that they show a perfect correlation between them. The conclusion that the principal components of the R-mode or the Q-mode have the same interpretation is established.
An example is given to illustrate this work. The resulting interpretation is found to be the same as that obtained by Donald L. Phillips (1977) using different methods
Microbial differences between dental plaque and historic dental calculus are related to oral biofilm maturation stage
Dental calculus, calcified oral plaque biofilm, contains microbial and host biomolecules that can be used to study historic microbiome communities and host responses. Dental calculus does not typically accumulate as much today as historically, and clinical oral microbiome research studies focus primarily on living dental plaque biofilm. However, plaque and calculus reflect different conditions of the oral biofilm, and the differences in microbial characteristics between the sample types have not yet been systematically explored. Here, we compare the microbial profiles of modern dental plaque, modern dental calculus, and historic dental calculus to establish expected differences between these substrates.- Background - Results -- Authentication of a preserved oral biofilm in calculus samples -- Dental calculus and plaque biofilm communities are distinct -- Health-associated communities of dental plaque and calculus are distinct -- Signatures of health and of disease are shared in modern and historic calculus samples -- Microbial community differences between health and disease in calculus are poorly resolved -- Absence of caries-specific microbial profiles in dental calculus -- Microbial co-exclusion patterns in plaque and calculus reflect biofilm maturity -- Microbial complexes in plaque and calculus -- Functional prediction in calculus is poorly predictive of health status -- Proteomic profiles of historic healthy site calculus -- Correlations between taxonomic, proteomic, and metabolomic profiles - Discussion - Conclusions - Materials and methods --Historic and modern calculus sample collection DNA extraction -- DNA library construction and high-throughput sequencing -- DNA sequence processing -- Genetic assessment of historic calculus sample preservation -- Genetic microbial taxonomic profiling -- Principal component analysis -- Assessment of differentially abundant taxa -- Sparse partial least squares-discriminant analysis -- Assessment of microbial co-exclusion patterns -- Gene functional categorization with SEED -- Proteomics -- Metabolomics -- Regularized canonical correlation analysi
Questions and answers regarding character education in Latin-American countries (Mexico, Colombia and Argentina). An exploratory Delphi study.
Abstract: In the project Researching and Promoting Character Education in Latin Ameri-can Secondary Schools funded by the Templeton World Charity Foundation,we address how Character Education is perceived in three Latin-American countries (Argentina, Colom-bia and Mexico). To carry out this research we produced a pilot study based on the Delphi method, in order to find the most relevant issues regarding the subject of Character Educa-tion in those Countries. This methodology offers us a rigorous and easily managed means of obtaining in-depth knowledge of the current problems of Character Education. For the Delphi study, we relied on the participation of various experts from the academic, school and administrative areas. During the process, we carried out three sessions with the experts in order to reach the highest possible consensus. Thus, we used two rounds of closed and open questions to obtain a good perspective of the situation. The result confirmed that Character Education is not a common term in the world of education in these countries. Moreover, this type of education is affected by the influence and relationship between the actors and the explicit-hidden curricula.En el proyecto Researching and Promoting Character Education in Latin American Secondary Schools, financiado por la Templeton World Charity Foundation, nos aproximamos a la percepción que de la Educación del Carácter se tiene en Argentina, Colombia y México.
La Educación del Carácter nos interesó dado que integra algunas de las propuestas para promover la ciudadanía.
Para el inicio de esta investigación elaboramos un estudio piloto basándonos en la metodología Delphi, con el objetivo de discernir cuáles son los temas más candentes alrededor de la Educación del Carácter en estos países. Esta metodología -rigurosa y de fácil manejo- permite la obtención de un conocimiento en profundidad sobre la problemática de la Educación del Carácter.
Contamos con la participación de diferentes expertos del ámbito académico, escolar y administrativo. Durante el proceso realizamos tres interacciones con los expertos para alcanzar un mayor consenso en sus opiniones. Para ello aplicamos dos rondas de preguntas cerradas y abiertas con las que obtener una mayor riqueza y convergencia en los datos obtenidos.
Como resultado, constatamos que la Educación del Carácter no es un término habitual en el ámbito educativo de estos países. Además, en este tipo de educación incide la influencia y relación entre los agentes y el currículum explícito-oculto en la escuela
The Role of Glypicans in Wnt Inhibitory Factor-1 Activity and the Structural Basis of Wif1's Effects on Wnt and Hedgehog Signaling
Proper assignment of cellular fates relies on correct interpretation of Wnt and Hedgehog (Hh) signals. Members of the Wnt Inhibitory Factor-1 (WIF1) family are secreted modulators of these extracellular signaling pathways. Vertebrate WIF1 binds Wnts and inhibits their signaling, but its Drosophila melanogaster ortholog Shifted (Shf) binds Hh and extends the range of Hh activity in the developing D. melanogaster wing. Shf activity is thought to depend on reinforcing interactions between Hh and glypican HSPGs. Using zebrafish embryos and the heterologous system provided by D. melanogaster wing, we report on the contribution of glypican HSPGs to the Wnt-inhibiting activity of zebrafish Wif1 and on the protein domains responsible for the differences in Wif1 and Shf specificity. We show that Wif1 strengthens interactions between Wnt and glypicans, modulating the biphasic action of glypicans towards Wnt inhibition; conversely, glypicans and the glypican-binding “EGF-like” domains of Wif1 are required for Wif1's full Wnt-inhibiting activity. Chimeric constructs between Wif1 and Shf were used to investigate their specificities for Wnt and Hh signaling. Full Wnt inhibition required the “WIF” domain of Wif1, and the HSPG-binding EGF-like domains of either Wif1 or Shf. Full promotion of Hh signaling requires both the EGF-like domains of Shf and the WIF domains of either Wif1 or Shf. That the Wif1 WIF domain can increase the Hh promoting activity of Shf's EGF domains suggests it is capable of interacting with Hh. In fact, full-length Wif1 affected distribution and signaling of Hh in D. melanogaster, albeit weakly, suggesting a possible role for Wif1 as a modulator of vertebrate Hh signaling
PhyloToAST: Bioinformatics Tools for Species-Level Analysis and Visualization of Complex Microbial Datasets
The 16S rRNA gene is widely used for taxonomic profiling of microbial ecosystems; and recent advances in sequencing chemistry have allowed extremely large numbers of sequences to be generated from minimal amounts of biological samples. Analysis speed and resolution of data to species-level taxa are two important factors in large-scale explorations of complex microbiomes using 16S sequencing. We present here new software, Phylogenetic Tools for Analysis of Species-level Taxa (PhyloToAST), that completely integrates with the QIIME pipeline to improve analysis speed, reduce primer bias (requiring two sequencing primers), enhance species-level analysis, and add new visualization tools. The code is free and open source, and can be accessed at http://phylotoast.org
El declive de la educación del carácter en Estados Unidos durante el siglo XX
El objetivo de este estudio es reflexionar sobre cinco factores que influyeron en el declive de la educación del carácter en Estados Unidos durante el siglo XX, con el ánimo de entender mejor la compleja situación actual de este enfoque educativo: 1) una relación mal entendida con el ámbito religioso que la excluye de la educación pública laica; 2) los paradigmas sociales del progreso y de la fragilidad de la infancia que contribuyen a desestimarla o considerarla inconveniente; 3) concebirla como mero adiestramiento en el que no se considera el desarrollo moral racional; 4) el relativismo moral; y, por último, 5) las críticas de la Psicología. Para finalizar, se ofrecen unas reflexiones que incluyen diversos testimonios recientes a favor de la educación del carácter y se sugiere la necesidad de integrar este ámbito en los sistemas educativos para enfrentar los retos morales y sociales del siglo XXI.The aim of this study is to reflect on five factors that influenced the decline of character education in the United States during the 20th century, in order to gain a deeper understanding of the current complex situation of this educational field: 1) a misunderstood relationship with the religious sphere that excludes it from public secular education; 2) the social paradigms of progress and childhood fragility that contribute to reject it, or consider it inconvenient; 3) conceiving it as mere training in which rational moral development is not considered; 4) moral relativism; and, finally, 5) the criticisms of Psychology. At last, several recent testimonies in favor of character education are included. Our final reflections suggest the need to integrate this area into education systems to face the moral and social challenges of the 21st century
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