Scalar fluctuations of the scalar metric during inflation from a non-perturbative 5D large-scale repulsive gravity model

We develop a non-perturbative formalism for scalar metric fluctuations from a 5D extended version of general relativity in vacuum. In this work we concentrate our efforts on calculations valid on large cosmological scales, which are the dominant during the inflationary phase of the universe. The resulting metric in this limit is obtained after implementing a planar coordinate transformation on a 5D Ricci-flat metric solution. We calculate the spectrum of these fluctuations with an effective 4D Schwarzschild-de Sitter spacetime on cosmological scales, which is obtained after we make a static foliation on the non-compact extra coordinate. Our results show how the squared metric fluctuations of the primordial universe become scale invariant with the inflationary expansion.Comment: Final version to be published in EPJ

A comparação da estrutura social de turmas de graduação e pós-graduação : um entendimento da cartografia dos grupos

Diversos cientistas lançaram-se em busca de explicações para o fenômeno dos grupos. O que se propõe aqui é a possibilidade da utilização do software Ucinet 6.0 e Pajek 1.10 para demonstrar a denominada 'cartografia' de dois grupos acadêmicos. Pretende-se colaborar com o entendimento das relações de tais grupos em favor de um melhor aproveitamento acadêmico. A estrutura de relações entre os estudantes destes grupos acadêmicos pode influenciar na capacidade de aprendizado e na produção destes grupos. Por meio da análise de redes sociais, se objetivou verificar estas estruturas de relações. Metodologicamente, uma survey, aplicada uma turma de pós-graduação e em uma de graduação em administração. Com o uso dos softwares, suas redes de relações foram elaboradas, sendo possível desta maneira, verificar as características estruturais e posicionais da rede e dos alunos nela. Verificou-se que a densidade de turmas menores, como a de pósgraduação é maior, assim como são menores suas distâncias. Foi observado ainda que os alunos mais centrais, tendem a ter melhor aproveitamento acadêmico e alunos mais isolados tendem a ter maior dificuldades de desempenho. Percebe-se que a análise de redes sociais pode ser um bom instrumento de avaliação dos alunos.Different scientist tried to explain the dynamics of small groups. This paper present the application of Ucinet 6.o and Pajek 1.10 for getting a "cartography" of two academic groups with the aim of showing how the structure of relationships affects the academic outcomes. Through a survey applied to one group of undergraduate students and other group of graduate students (both in Management sciences) and the analysis of the pattern of relationships we found that more central students had better results that the periferic ones. This finding suggests the possibility of using social network analysis as a tool for student's assessment

An unbalanced approach to metric space searching

Proximity queries (the searching problem generalized beyond exact match) is mostly modeled as metric space. A metric space consists of a collection of objects and a distance function defined among them. The goal is to preprocess the data set (a slow procedure) to quickly answer proximity queries. This problem have received a lot of attention recently, specially in the pattern recognition community. The Excluded Middle Vantage Point Forest (VP–forest) is a data structure designed to search in high dimensional vector spaces. A VP–forest is built as a collection of balanced Vantage Point Trees (VP–trees). In this work we propose a novel two-fold approach for searching. Firstly we extend the VP– forest to search in metric spaces, and more importantly we test a counterintuitive modification to the VP–tree, namely to unbalance it. In exact searching an unbalanced data structure perform poorly, and most of the algorithmic effort is directed to obtain a balanced data structure. The unbalancing approach is motivated by a recent data structure (the List of Clusters ) specialized in high dimensional metric space searches, which is an extremely unbalanced data structure (a linked list) outperforming other approaches.Eje: AlgoritmosRed de Universidades con Carreras en Informática (RedUNCI

Solving All-k-Nearest Neighbor Problem without an Index

Among the similarity queries in metric spaces, there are one that obtains the k-nearest neighbors of all the elements in the database (All-k-NN). One way to solve it is the naïve one: comparing each object in the database with all the other ones and returning the k elements nearest to it (k-NN). Another way to do this is by preprocessing the database to build an index, and then searching on this index for the k-NN of each element of the dataset. Answering to the All-k-NN problem allows to build the k-Nearest Neighbor graph (kNNG). Given an object collection of a metric space, the Nearest Neighbor Graph (NNG) associates each node with its closest neighbor under the given metric. If we link each object to their k nearest neighbors, we obtain the k Nearest Neighbor Graph (kNNG).The kNNG can be considered an index for a database, which is quite efficient and can allow improvements. In this work, we propose a new technique to solve the All-k-NN problem which do not use any index to obtain the k-NN of each element. This approach solves the problem avoiding as many comparisons as possible, only comparing some database elements and taking advantage of the distance function properties. Its total cost is significantly lower than that of the naïve solution.XVI Workshop Bases de Datos y Minería de Datos.Red de Universidades con Carreras en Informátic

"“RELACIONES INTRAFAMILIARES Y OBESIDAD INFANTIL EN NIÑOS DE 7 A 11 AÑOS DE EDAD DE LA UNIDAD DE MEDICINA FAMILIAR No. 75 DEL IMSS”

La obesidad infantil constituye un factor de riesgo de varias enfermedades crónicas no transmisibles asociado a la nutrición, algunas de las cuales son causas importantes de muerte, es una patología que ha ido incrementando con el paso del tiempo, convirtiéndose en un serio problema de salud pública a nivel mundial. Las últimas encuestas nacionales de nutrición han mostrado un incremento gradual en los niños, la mitad de los niños obesos en edad escolar serán obesos en edad adulta. Frente a problemas alimentarios y nutricionales tan serios como la obesidad, se ha encontrado que no hay una única causa o causas específicas, sino un conjunto de factores determinantes o influyentes, algunos más claros y estudiados que otros. Por ser un problema que se ha incrementado con paso lento pero continuo en las últimas décadas la obesidad infantil constituye un tema a investigar por parte de todas disciplinas que se relacionan con él con la finalidad de profundizar en su conocimiento e identificar posibles líneas de acción para prevenir su ocurrencia. Muchos temas han sido estudiados en relación a la obesidad infantil, sin embargo las relaciones intrafamiliares del paciente obeso ha sido poco explorada y resulta de utilidad contar con dicha información a fin de tener una visión integral de la familia

Plant Lectins with Insecticidal and Insectistatic Activities

Lectins are an important group of proteins which are spread in all kingdoms of life. Their most lighted characteristic is associated to their specific carbohydrate binding, although function has been not even identified. According to their carbohydrate specificity, several biological activities have been assessed, finding that lectins can be used as mitogenic agents, biomarkers, and cytotoxic and insecticide proteins. Lectins have been classified according to several features such as structure, source, and carbohydrate recognition. The Protein Research Group (PRG) has worked on Colombian seeds from the family of Fabaceae and Lamiaceae plants, isolating and characterizing their lectins, and found more than one lectin in some plants, indicating that according to its specificity, different lectins can have different biological activities. In the case of legume domain lectins, they have shown the biggest potential as insecticide or insectistatic agents due to the glycosylation pattern in insect midgut cells. This review attempts to identify the characteristics of plant legume lectin domains that determine their insecticidal and insectistatic activities

A hybrid data structure for searching in metric spaces

The concept of “approximate” searching has applications in a vast number of fields. Some examples are non-traditional databases (e. g. storing images, fingerprints or audio clips, where the concept of exact search is of no use and we search instead for similar objects), text searching, information retrieval, machine learning and classification, image quantization and compression, computational biology, and function prediction.Eje: Base de datosRed de Universidades con Carreras en Informática (RedUNCI