A lower bound for the energy of symmetric matrices and graphs

The energy of a symmetric matrix is the sum of the absolute values of its eigenvalues. We introduce a lower bound for the energy of a symmetric partitioned matrix into blocks. This bound is related to the spectrum of its quotient matrix. Furthermore, we study necessary conditions for the equality. Applications to the energy of the generalized composition of a family of arbitrary graphs are obtained. A lower bound for the energy of a graph with a bridge is given. Some computational experiments are presented in order to show that, in some cases, the obtained lower bound is incomparable with the well known lower bound $2\sqrt{m}$, where $m$ is the number of edges of the graph.

The bioconcentration factor of pesticides in potatoes.

We presented a model that estimates the bioconcentration factor (BCF) of pesticides in potatoes supposing that the pesticide in the soil solution is absorbed by the potato by passive diffusion, following Fick?s second law. The pesticides in the model are nonionic organic substances, traditionally used in potato crops that degrade in the soil according to a first order kinetic equation. This presents an expression that relates BCF with the pesticide elimination rate by the potato, with the pesticide accumulation rate within the potato, with the rate of growth of the potato and with the pesticide degradation rate in the soil. BCF was estimated supposing steady state equilibrium of the quotient between the pesticide concentration in the potato and the pesticide concentration in the soil solution. It is suggested that a negative correlation exists between the pesticide BCF and the soil sorption partition coefficient. The model was built based on the work of Trapp et al. (2007), [Diffusion of PAH in Potato and Carrot Slices and Applications for a Potato Model] in which an expression to calculate the diffusivity of persistent organic substances in potatoes is presented. The model consists in adding to the expression of Trapp et al. (2007) the hypothesis that the pesticide degrades in the soil. The value of BCF suggests which pesticides should be monitored in potatoes.

Optimal reparametrizations in the square root velocity framework

The square root velocity framework is a method in shape analysis to define a distance between curves and functional data. Identifying two curves, if the differ by a reparametrization leads to the quotient space of unparametrized curves. In this paper we study analytical and topological aspects of this construction for the class of absolutely continuous curves. We show that the square root velocity transform is a homeomorphism and that the action of the reparametrization semigroup is continuous. We also show that given two $C^1$-curves, there exist optimal reparametrizations realising the minimal distance between the unparametrized curves represented by them.

O stresse em alunos de enfermagem e a sua influência na relação de ajuda com o doente

Dissertação de mest. em Observação e Análise da Relação Educativa, Faculdade de Ciências Humanas e Sociais, Univ. do Algarve, Escola Superior de Educação, Instituto Politécnico de Beja, 2005

O comprimento descritivo mínimo na amostragem por transectos lineares

Apresenta·se um breve resumo histórico da evolução da amostragem por transectos lineares e desenvolve·se a sua teoria. Descrevemos a teoria de amostragem por transectos lineares, proposta por Buckland (1992), sendo apresentados os pontos mais relevantes, no que diz respeito à modelação da função de detecção. Apresentamos uma descrição do princípio CDM (Rissanen, 1978) e a sua aplicação à estimação de uma função densidade por um histograma (Kontkanen e Myllymãki, 2006), procedendo à aplicação de um exemplo prático, recorrendo a uma mistura de densidades. Procedemos à sua aplicação ao cálculo do estimador da probabilidade de detecção, no caso dos transectos lineares e desta forma estimar a densidade populacional de animais. Analisamos dois casos práticos, clássicos na amostragem por distâncias, comparando os resultados obtidos. De forma a avaliar a metodologia, simulámos vários conjuntos de observações, tendo como base o exemplo das estacas, recorrendo às funções de detecção semi-normal, taxa de risco, exponencial e uniforme com um cosseno. Os resultados foram obtidos com o programa DISTANCE (Thomas et al., in press) e um algoritmo escrito em linguagem C, cedido pelo Professor Doutor Petri Kontkanen (Departamento de Ciências da Computação, Universidade de Helsínquia). Foram desenvolvidos programas de forma a calcular intervalos de confiança recorrendo à técnica bootstrap (Efron, 1978). São discutidos os resultados finais e apresentadas sugestões de desenvolvimentos futuros. ABSTRACT; We present a brief historical note on the evolution of line transect sampling and its theoretical developments. We describe line transect sampling theory as proposed by Buckland (1992), and present the most relevant issues about modeling the detection function. We present a description of the CDM principle (Rissanen, 1978) and its application to histogram density estimation (Kontkanen and Myllymãki, 2006), with a practical example, using a mixture of densities. We proceed with the application and estimate probability of detection and animal population density in the context of line transect sampling. Two classical examples from the literature are analyzed and compared. ln order to evaluate the proposed methodology, we carry out a simulation study based on a wooden stakes example, and using as detection functions half normal, hazard rate, exponential and uniform with a cosine term. The results were obtained using program DISTANCE (Thomas et al., in press), and an algorithm written in C language, kindly offered by Professor Petri Kontkanen (Department of Computer Science, University of Helsinki). We develop some programs in order to estimate confidence intervals using the bootstrap technique (Efron, 1978). Finally, the results are presented and discussed with suggestions for future developments.

Digit recurence division under HUB format

Half-Unit-Biased format is based on shifting the representation line of the binary numbers by half Unit in the Last Place. The main feature of this format is that the round to nearest is carried out by a simple truncation, preventing any carry propagation and saving time and area. Algorithms and architectures have been defined for addition/substraction and multiplication operations under this format. Nevertheless, the division operation has not been confronted yet. In this paper we deal with the floating-point division under HUB format, studying the architecture for the digit recurrence method, including the on-the-fly conversion of the signed digit quotient.

The Relationships between Elementary School Principals' Emotional Intelligence, Leadership Style and School Culture

The role of the principal in school settings and the principal’s perceived effect on student achievement have frequently been considered vital factors in school reform. The relationships between emotional intelligence, leadership style and school culture have been widely studied. The literature reveals agreement among scholars regarding the principal’s vital role in developing and fostering a positive school culture. The purpose of this study was to explore the relationships between elementary school principals’ emotional intelligence, leadership style and school culture. The researcher implemented a non-experimental ex post facto research design to investigate four specific research hypotheses. Utilizing the Qualtrics Survey Software, 57 elementary school principals within a large urban school district in southeast Florida completed the Emotional Quotient Inventory (EQ-i), and 850 of their faculty members completed the Multifactor Leadership Questionnaire (MLQ Form 5X). Faculty responses to the school district’s School Climate Survey retrieved from the district’s web site were used as the measure of school culture. Linear regression analyses revealed significant positive associations between emotional intelligence and the following leadership measures: Idealized Influence-Attributes (β = .23, p = < .05), Idealized Influence-Behaviors (β = .34, p = < .01), Inspirational Motivation (β = .39, p = < .01) and Contingent Reward (β = .33, p = < .01). Hierarchical regression analyses revealed positive associations between school culture and both transformational and transactional leadership measures, and negative associations between school culture and passive-avoidant leadership measures. Significant positive associations were found between school culture and the principals’ emotional intelligence over and above leadership style. Hierarchical linear regressions to test the statistical hypothesis developed to account for alternative explanations revealed significant associations between leadership style and school culture over and above school grade. These results suggest that emotional intelligence merits consideration in the development of leadership theory. Practical implications include suggestions that principals employ both transformational and transactional leadership strategies, and focus on developing their level of emotional intelligence. The associations between emotional intelligence, transformational leadership, Contingent Reward and school culture found in this study validate the role of the principal as the leader of school reform.

Ensemble Stream Model for Data-Cleaning in Sensor Networks

Ensemble Stream Modeling and Data-cleaning are sensor information processing systems have different training and testing methods by which their goals are cross-validated. This research examines a mechanism, which seeks to extract novel patterns by generating ensembles from data. The main goal of label-less stream processing is to process the sensed events to eliminate the noises that are uncorrelated, and choose the most likely model without over fitting thus obtaining higher model confidence. Higher quality streams can be realized by combining many short streams into an ensemble which has the desired quality. The framework for the investigation is an existing data mining tool. First, to accommodate feature extraction such as a bush or natural forest-fire event we make an assumption of the burnt area (BA*), sensed ground truth as our target variable obtained from logs. Even though this is an obvious model choice the results are disappointing. The reasons for this are two: One, the histogram of fire activity is highly skewed. Two, the measured sensor parameters are highly correlated. Since using non descriptive features does not yield good results, we resort to temporal features. By doing so we carefully eliminate the averaging effects; the resulting histogram is more satisfactory and conceptual knowledge is learned from sensor streams. Second is the process of feature induction by cross-validating attributes with single or multi-target variables to minimize training error. We use F-measure score, which combines precision and accuracy to determine the false alarm rate of fire events. The multi-target data-cleaning trees use information purity of the target leaf-nodes to learn higher order features. A sensitive variance measure such as f-test is performed during each node’s split to select the best attribute. Ensemble stream model approach proved to improve when using complicated features with a simpler tree classifier. The ensemble framework for data-cleaning and the enhancements to quantify quality of fitness (30% spatial, 10% temporal, and 90% mobility reduction) of sensor led to the formation of streams for sensor-enabled applications. Which further motivates the novelty of stream quality labeling and its importance in solving vast amounts of real-time mobile streams generated today.

Reducing the number of questions in nonlocal games

We show how a vector-valued version of Schechtmans empirical method can be used to reduce the number of questions in a nonlocal game G while preserving the quotient β*(G)/β(G) of the quantum over the classical bias. We apply our method to the Khot-Vishnoi game, with exponentially many questions per player, to produce a family of games indexed in n with polynomially many (N ≈ n8) questions and n answers per player so that the ratio of the quantum over the classical bias is Ω(n/log2 n).

Assessment of resting energy expenditure in pediatric mitochondrial diseases with indirect calorimetry

Mitochondrial diseases (MD) are the most frequent inborn errors of metabolism. In affected tissues, MD can alter cellular oxygen consumption rate leading to potential decreases in whole-body resting energy expenditure (REE), but data on pediatric children are absent. We determined, using indirect calorimetry (IC), whole-body oxygen consumption (VO2), carbon dioxide production (VCO2), respiratory quotient (RQ) and REE in pediatric patients with MD and healthy controls. Another goal was to assess the accuracy of available predictive equations for REE estimation in this patient population. IC data were obtained under fasting and resting conditions in 20 MD patients and 27 age and gender-matched healthy peers. We determined the agreement between REE measured with IC and REE estimated with Schofield weight and FAO/WHO/UNU equations. Mean values of VO2, VCO2 (mL·min-1·kg-1) or RQ did not differ significantly between patients and controls (P = 0.085, P = 0.055 and P = 0.626 respectively). Accordingly, no significant differences (P = 0.086) were found for REE (kcal·day-1 kg-1) either. On the other hand, although we found no significant differences between IC-measured REE and Schofield or FAO/WHO/UNU-estimated REE, Bland-Altman analysis revealed wide limits of agreement and there were some important individual differences between IC and equation-derived REE. VO2, VCO2, RQ and REE are not significantly altered in pediatric patients with MD compared with healthy controls. The energy demands of pediatric patients with MD should be determined based on IC data in order to provide the best possible personalized nutritional management for these children.

Valor diagnóstico del pepsinógeno i/ii como biomarcador de lesiones pre-malignas y malignas gástricas: revisión sistemática

Antecedentes: El cáncer gástrico se diagnostica tardíamente. Sólo en países como Corea y Japón existen políticas de tamizaje, que se justificarían en cualquier país con alta prevalencia de cáncer gástrico como Colombia o Chile. El análisis del pepsinógeno sérico se ha propuesto para el diagnóstico de lesiones premalignas y malignas gástricas, por lo cual se pretende revisar sistemáticamente en la literatura el valor diagnóstico del cociente pepsinógeno I/II como marcador de lesiones premalignas y malignas gástricas. Metodología: Se revisó la literatura hasta septiembre del 2016 con palabras claves lesiones malignas, premalignas gástricas y pepsinógeno en las bases de datos PubMed, OVID, EMBASE, EBSCO, LILACS, OPENGRAY y Dialnet, artículos de prueba diagnóstica que evaluaran el cociente pepsinógeno I/II en relación con los hallazgos histológicos. Resultados: Se incluyeron 21 artículos conun total de 20601 pacientes, que demuestranuna sensibilidad entre13.7% - 91.2%, una especificidad entre 38.5% - 100%, un Valor Predictivo Positivo entre 6.3% - 100% y un Valor Predictivo Negativo entre 33.3% - 98.8%del cociente pepsinógeno I/II en relación con el diagnósticode lesiones premalignas y malignas gástricas. Conclusiones: Los valores del cociente pepsinógeno I/II disminuidos se relacionan con la presencia delesiones premalignas y malignas gástricas.Dado que tiene mejor especificidad que sensibilidad, en cuanto prueba para tamizaje, sería útil para la selección de pacientes que se beneficiaríande la EVDA. Se requieren más estudios de prueba diagnóstica para validar un punto de corte específico que pueda ser utilizado como valor estándar.

Relación entre el liderazgo adaptativo e inteligencia emocional

Hoy por hoy la academia ha identificado el liderazgo y la inteligencia emocional como factores clave para la transformación de la sociedad, las comunidades e incluso las mismas organizaciones, puesto que, se ha demostrado que un líder es capaz de influenciar a sus seguidores para fomentar un cambio en sus estructura de valores, lo que permite adaptarse, afrontar diferentes situaciones y retos que se les presenten. Investigaciones han demostrado que las personas que ejercen el liderazgo adaptativo de manera adecuada cuentan con un conjunto de habilidades y herramientas que les permiten influir en la sociedad, en los individuos que la componen y los valores que tienen, lo que permite generar cambios positivos dentro de la estructura social a la que pertenezca.

Avaliação do potencial de desenvolvimento em meninos e meninas dos 4 aos 6 anos

Todos nós, educadores, devemos prestar uma atenção aprofundada às potencialidades e inclinações das crianças que constituem os nossos grupos, para que possamos estimular e desenvolver as suas competências. É nesse sentido que desenvolvemos este Estudo Exploratório, com o qual se pretende analisar a adaptação da avaliação de potencial derivada da Teoria das Inteligência Múltiplas ao contexto da Educação Pré-Escolar, com o objectivo de contribuir para a qualidade da intervenção educativa, articulando conceitos como Inteligência, Competência, Potencial, Currículo, Avaliação Dinâmica. Participam no estudo 42 crianças que frequentam Jardim de Infância e integram dois grupos heterogéneos e as respectivas educadoras. A metodologia é de natureza qualitativa e quantitativa, apoiando-se na aplicação dos seguintes instrumentos: modelo de avaliação de potencial baseado no Spectrum; Inventário de Quociente Emocional, versão para crianças e jovens (Bar-On Emocional Quotient Inventory: Youth Version), adaptado a educadores por Candeias e Monteiro (2010); questionário de Caracterização do ambiente educativo - Sala de Actividades, adaptado por Candeias e lglésias (2010); Teste de Avaliação de Habilidades Cognitivas de Solução de Problemas lnterpessoais (EVHACOSPI). Os resultados obtidos sugerem a importância de uma avaliação do potencial, baseada na Teoria das Inteligências Múltiplas, que utiliza instrumentos adequados a cada um dos domínios do potencial e da competência humana propostos por H. Gardner: verbal, Lógico-Matemática, Musical, Corporal-Cinestésica, Visuo-espacial, lnterpessoal, Intrapessoal e Naturalista. Apontam também para o papel que este tipo de avaliação pode desempenhar na intervenção educativa que se objectiva intencional e fundamentada. ABSTRACT: Ali of us, educators, must pay a special attention to the potentialities and inclinations of children who make up our groups, so enabling the stimulation and development of their competences. ln this sense we developed this Exploratory Study, through which is intended to analyse the adaptation of potential evaluation derived from the Theory of Multiple intelligences in the range of Pre-School Education, aiming at the contribution for the educative intervention: articulating concepts such as Intelligence, Competence Potential, Curriculum, and Dynamic Evaluation. The study involves 42 children attending Infant School, belonging to two heterogeneous groups and respective educators. Methodology is of qualitative and quantitative nature, supported by the following instruments: evaluation model based on Spectrum; Inventory of Emotional Quotient, version for children and youths, adapted to educators by Candeias e Monteiro (2010), Query of Characterization of Educative Environment - Activities Room, adapted by Candeias e lglésias (2010); Test for Evaluation of Cognitive Abilities of Interpersonal Problems Solution. (EVHACOSPI). The results suggest the importance of an assessment, based on the Theory of Multiple Intelligence, which uses instruments fitted to each of the domains of human potential and competence proposed by H. Gardiner: Verbal, Logical-Maths, Musical, Corporal¬ Kinaesthetic, Visuo-Spatial, Interpersonal, Intrapersonal and Naturalist. They also refer to the role that this type of assessment can play in the educational intervention aiming to be intentional and grounded.