Continuum in the X-Z-Y Weak Bonds: Z= Main Group Elements

The Continuum in the variation of the X-Z bond length change from blue-shifting to red-shifting through zero-shifting in the X-Z---Y complex is inevitable. This has been analyzed by ab-initio molecular orbital calculations using Z= Hydrogen, Halogens, Chalcogens, and Pnicogens as prototypical examples. Our analysis revealed that, the competition between negative hyperconjugation within the donor (X-Z) molecule and Charge Transfer (CT) from the acceptor (Y) molecule is the primary reason for the X-Z bond length change. Here, we report that, the proper tuning of X-and Y-group for a particular Z-can change the blue-shifting nature of X-Z bond to zero-shifting and further to red-shifting. This observation led to the proposal of a continuum in the variation of the X-Z bond length during the formation of X-Z---Y complex. The varying number of orbitals and electrons available around the Z-atom differentiates various classes of weak interactions and leads to interactions dramatically different from the H-Bond. Our explanations based on the model of anti-bonding orbitals can be transferred from one class of weak interactions to another. We further take the idea of continuum to the nature of chemical bonding in general. (C) 2015 Wiley Periodicals, Inc.

Anatomical and developmental patterns of interleukin-2 gene expression in the mouse: analysis of IL-2 expressing cells and partial characterization of interactions involved in mediating IL-2 gene expression in vivo

Interleukin-2 (IL-2) is an important mediator in the vertebrate immune system. IL-2 is a potent growth factor that mature T lymphocytes use as a proliferation signal and the production of IL-2 is crucial for the clonal expansion of antigen-specific T cells in the primary immune response. IL-2 driven proliferation is dependent on the interaction of the lymphokine with its cognate multichain receptor. IL-2 expression is induced only upon stimulation and transcriptional activation of the IL-2 gene relies extensively on the coordinate interaction of numerous inducible and constitutive trans-acting factors. Over the past several years, thousands of papers have been published regarding molecular and cellular aspects of IL-2 gene expression and IL-2 function. The vast majority of these reports describe work that has been carried out in vitro. However, considerably less is known about control of IL-2 gene expression and IL-2 function in vivo.

To gain new insight into the regulation of IL-2 gene expression in vivo, anatomical and developmental patterns of IL-2 gene expression in the mouse were established by employing in situ hybridization and immunohistochemical staining methodologies to tissue sections generated from normal mice and mutant animals in which T -cell development was perturbed. Results from these studies revealed several interesting aspects of IL-2 gene expression, such as (1) induction of IL-2 gene expression and protein synthesis in the thymus, the primary site of T-cell development in the body, (2) cell-type specificity of IL-2 gene expression in vivo, (3) participation of IL-2 in the extrathymic expansion of mature T cells in particular tissues, independent of an acute immune response to foreign antigen, (4) involvement of IL-2 in maintaining immunologic balance in the mucosal immune system, and (5) potential function of IL-2 in early events associated with hematopoiesis.

Extensive analysis of IL-2 mRNA accumulation and protein production in the murine thymus at various stages of development established the existence of two classes of intrathymic IL-2 producing cells. One class of intrathymic IL-2 producers was found exclusively in the fetal thymus. Cells belonging to this subset were restricted to the outermost region of the thymus. IL-2 expression in the fetal thymus was highly transient; a dramatic peak ofiL-2 mRNA accumulation was identified at day 14.5 of gestation and maximal IL-2 protein production was observed 12 hours later, after which both IL-2 mRNA and protein levels rapidly decreased. Significantly, the presence of IL-2 expressing cells in the day 14-15 fetal thymus was not contingent on the generation of T-cell receptor (TcR) positive cells. The second class of IL-2 producing cells was also detectable in the fetal thymus (cells found in this class represented a minority subset of IL-2 producers in the fetal thymus) but persist in the thymus during later stages of development and after birth. Intrathymic IL-2 producers in postnatal animals were located in the subcapsular region and cortex, indicating that these cells reside in the same areas where immature T cells are consigned. The frequency of IL-2 expressing cells in the postnatal thymus was extremely low, indicating that induction of IL-2 expression and protein synthesis are indicative of a rare activation event. Unlike the fetal class of intrathymic IL-2 producers, the presence of IL-2 producing cells in the postnatal thymus was dependent on to the generation of TcR+ cells. Subsequent examination of intrathymic IL-2 production in mutant postnatal mice unable to produce either αβ or γδ T cells showed that postnatal IL-2 producers in the thymus belong to both αβ and γδ lineages. Additionally, further studies indicated that IL-2 synthesis by immature αβ -T cells depends on the expression of bonafide TcR αβ-heterodimers. Taken altogether, IL-2 production in the postnatal thymus relies on the generation of αβ or γδ-TcR^+ cells and induction of IL-2 protein synthesis can be linked to an activation event mediated via the TcR.

With regard to tissue specificity of IL-2 gene expression in vivo, analysis of whole body sections obtained from normal neonatal mouse pups by in situ hybridization demonstrated that IL-2 mRNA^+ cells were found in both lymphoid and nonlymphoid tissues with which T cells are associated, such as the thymus (as described above), dermis and gut. Tissues devoid of IL-2 mRNA^+ cells included brain, heart, lung, liver, stomach, spine, spinal cord, kidney, and bladder. Additional analysis of isolated tissues taken from older animals revealed that IL-2 expression was undetectable in bone marrow and in nonactivated spleen and lymph nodes. Thus, it appears that extrathymic IL-2 expressing cells in nonimmunologically challenged animals are relegated to particular epidermal and epithelial tissues in which characterized subsets of T cells reside and thatinduction of IL-2 gene expression associated with these tissues may be a result of T-cell activation therein.

Based on the neonatal in situ hybridization results, a detailed investigation into possible induction of IL-2 expression resulting in IL-2 protein synthesis in the skin and gut revealed that IL-2 expression is induced in the epidermis and intestine and IL-2 protein is available to drive cell proliferation of resident cells and/or participate in immune function in these tissues. Pertaining to IL-2 expression in the skin, maximal IL-2 mRNA accumulation and protein production were observed when resident Vγ_3^+ T-cell populations were expanding. At this age, both IL-2 mRNA^+ cells and IL-2 protein production were intimately associated with hair follicles. Likewise, at this age a significant number of CD3ε^+ cells were also found in association with follicles. The colocalization of IL-2 expression and CD3ε^+ cells suggests that IL-2 expression is induced when T cells are in contact with hair follicles. In contrast, neither IL-2 mRNA nor IL-2 protein were readily detected once T-cell density in the skin reached steady-state proportions. At this point, T cells were no longer found associated with hair follicles but were evenly distributed throughout the epidermis. In addition, IL-2 expression in the skin was contingent upon the presence of mature T cells therein and induction of IL-2 protein synthesis in the skin did not depend on the expression of a specific TcR on resident T cells. These newly disclosed properties of IL-2 expression in the skin indicate that IL-2 may play an additional role in controlling mature T-cell proliferation by participating in the extrathymic expansion of T cells, particularly those associated with the epidermis.

Finally, regarding IL-2 expression and protein synthesis in the gut, IL-2 producing cells were found associated with the lamina propria of neonatal animals and gut-associated IL-2 production persisted throughout life. In older animals, the frequency of IL-2 producing cells in the small intestine was not identical to that in the large intestine and this difference may reflect regional specialization of the mucosal immune system in response to enteric antigen. Similar to other instances of IL-2 gene expression in vivo, a failure to generate mature T cells also led to an abrogation of IL-2 protein production in the gut. The presence of IL-2 producing cells in the neonatal gut suggested that these cells may be generated during fetal development. Examination of the fetal gut to determine the distribution of IL-2 producing cells therein indicated that there was a tenfold increase in the number of gut-associated IL-2 producers at day 20 of gestation compared to that observed four days earlier and there was little difference between the frequency of IL-2 producing cells in prenatal versus neonatal gut. The origin of these fetally-derived IL-2 producing cells is unclear. Prior to the immigration of IL-2 inducible cells to the fetal gut and/or induction of IL-2 expression therein, IL-2 protein was observed in the fetal liver and fetal omentum, as well as the fetal thymus. Considering that induction of IL-2 protein synthesis may be an indication of future functional capability, detection of IL-2 producing cells in the fetal liver and fetal omentum raises the possibility that IL-2 producing cells in the fetal gut may be extrathymic in origin and IL-2 producing cells in these fetal tissues may not belong solely to the T lineage. Overall, these results provide increased understanding of the nature of IL-2 producing cells in the gut and how the absence of IL-2 production therein and in fetal hematopoietic tissues can result in the acute pathology observed in IL-2 deficient animals.

Detecção de falhas em circuitos eletrônicos lineares baseados em classificadores de classe única.

Esse trabalho está baseado na investigação dos detectores de falhas aplicando classificadores de classe única. As falhas a serem detectadas são relativas ao estado de funcionamento de cada componente do circuito, especificamente de suas tolerâncias (falha paramétrica). Usando a função de transferência de cada um dos circuitos são gerados e analisados os sinais de saída com os componentes dentro e fora da tolerância. Uma função degrau é aplicada à entrada do circuito, o sinal de saída desse circuito passa por uma função diferenciadora e um filtro. O sinal de saída do filtro passa por um processo de redução de atributos e finalmente, o sinal segue simultaneamente para os classificadores multiclasse e classe única. Na análise são empregados ferramentas de reconhecimento de padrões e de classificação de classe única. Os classficadores multiclasse são capazes de classificar o sinal de saída do circuito em uma das classes de falha para o qual foram treinados. Eles apresentam um bom desempenho quando as classes de falha não possuem superposição e quando eles não são apresentados a classes de falhas para os quais não foram treinados. Comitê de classificadores de classe única podem classificar o sinal de saída em uma ou mais classes de falha e também podem classificá-lo em nenhuma classe. Eles apresentam desempenho comparável ao classificador multiclasse, mas também são capazes detectar casos de sobreposição de classes de falhas e indicar situações de falhas para os quais não foram treinados (falhas desconhecidas). Os resultados obtidos nesse trabalho mostraram que os classificadores de classe única, além de ser compatível com o desempenho do classificador multiclasse quando não há sobreposição, também detectou todas as sobreposições existentes sugerindo as possíveis falhas.

A matriz eletronuclear no Brasil proposta de um marco jurídico adequado: natureza de serviço público das atividades do ciclo nuclear e a necessidade de uma entidade reguladora autônoma.

Partindo de uma análise histórica comparativa do tratamento da questão nuclear no Brasil, buscou-se compreender os condicionantes da estrutura normativa constitucional do tema atômico na atual Carta de 1988 para então lançar-se a uma análise crítica do atual quadro institucional, posto que é anterior à Constituição, mas que teria sido pela mesma recepcionado. Após esta análise crítica, tenta-se, no mesmo ambiente, reconstruir uma tessitura mínima para um ramo jurídico da energia nuclear, analisando, juntamente, a natureza das atividades do chamado ciclo nuclear. Enfim, cotejando todos estes dados, procura-se demonstrar que o atual marco legal é, ao menos, desatualizado e não atende a um projeto maior de desenvolvimento e controle das atividades nucleares no Brasil. Insta ainda salientar que, devido à própria natureza de uma tese de doutoramento, fez-se um recorte temático na questão nuclear, propositadamente não se aprofundando na temática referente à responsabilidade civil por dano nuclear, uma vez que já é tema tratado com bastante propriedade por variados escritos e autores.

Processamento digital de imagens destinado ao mapeamento da ocupação humana do alto Bonfim e análise histórica dos remanescentes florestais entre os anos de 1965 a 2006.

Através do processamento de imagens digitais, mais especificamente as etapas de segmentação e classificação, foi possível analisar o processo de ocupação humana da bacia hidrográfica do rio Bonfim, localizada no município de Petrópolis, no estado do Rio de Janeiro. Este processo possibilitou a geração de mapas de uso da terra e cobertura vegetal e configurou-se numa importante etapa para avaliação ambiental capaz de auxiliar e dar fomento à execução de atividades de gestão e monitoramento do meio ambiente e de análise histórica dos remanescentes florestais ao longo dos últimos anos. Nesta pesquisa foram adotadas classes temáticas com o propósito de permitir a classificação das imagens digitais na escala 1/40.000. As classes adotadas foram: afloramento rochoso e vegetação rupestre; obras e edificações; áreas agrícolas e vegetação. Estudos foram feitos no sentido de indicar o melhor método de classificação. Primeiramente, efetuou-se a classificação no sistema SPRING, testando-se os melhores parâmetros de similaridade e área na detecção de fragmentos, somente da classe vegetação. Houve tentativa de classificar as demais classes de uso diretamente pelo sistema SPRING, mas esta classificação não foi viável por apresentar conflitos em relação às classes, desta forma, neste sistema foi feita somente a classificação e quantificação da classe vegetação. Visando dar continuidade a pesquisa, optou-se por executar uma interpretação visual, através do sistema ArcGis, para todas as classes de uso do solo, possibilitando o mapeamento da dinâmica de evolução humana, diante da floresta de mata atlântica na área de estudos e análise histórica de seus remanescentes entre os anos dos anos 1965, 1975, 1994 e 2006.

Consumo de carnes por forma de preparo no Brasil.

A plausível associação entre o consumo de carnes e o desenvolvimento do câncer colorretal vem sendo em parte explicada pelo processo de formação de aminas heterocíclicas e hidrocarbonetos aromáticos durante a cocção. No Brasil este tipo de câncer encontra-se entre as três mais frequentes causas de óbito por câncer tanto em homens como em mulheres, sendo as regiões Sul e Sudeste as que apresentam as maiores taxas de mortalidade. Este estudo tem como objetivo estimar o consumo médio per capita e prevalência de carnes segundo formas de preparo no Brasil, com ênfase nas técnicas grelhado/brasa/churrasco e frito. Foram utilizados dados do Inquérito Nacional de Alimentação (INA) que faz parte da Pesquisa de Orçamentos Familiares (POF) realizado entre os anos de 2008 e 2009. Nesse inquérito foram analisadas informações referentes ao consumo alimentar de 34.003 indivíduos com dez anos de idade ou mais, contemplando questões a cerca da quantidade de alimentos consumidos em unidades de medidas caseiras, forma de preparo do alimento e local de consumo (alimentação dentro do domicílio ou quando o alimento foi preparado e consumido fora do domicílio). As medias de carnes em geral foram estratificadas por sexo, escolaridade, quarto de renda, grandes regiões geográficas, situação do domicílio (urbano/rural) e local de consumo (dentro/fora do lar). Para a extração dos valores médios per capita consumidos, foram utilizados os procedimentos survey para levar em consideração os efeitos do desenho amostral. Verificou-se que a maior média per capita de consumo em gramas ocorreu no grupo de carne bovina, e a forma de preparo frito apresentou a maior média per capita de ingestão (31 gramas/ dia). Agrupando-se todos os tipos de carnes em apenas uma classe, "carnes em geral", a forma de preparação frita permaneceu com média de consumo demasiadamente maior que a forma grelhado/brasa/churrasco em todas as variáveis analisadas. Quando desagregado pelas variáveis de interesse, a maior média de consumo per capita de carnes em geral ocorreu na mais alta categoria de escolaridade (21 gramas/ dia) para o tipo grelhado/brasa/churrasco e entre residentes da região Norte (111gramas/ dia) para o tipo frito. As menores médias per capita ocorreram entre os indivíduos no primeiro quarto de renda (1,96 gramas/ dia) para aqueles que consumiram grelhado/brasa/churrasco e para as carnes fritas a menor média foi observada fora do domicílio (20 gramas/ dia). Os achados indicam que existe uma acentuada diferença entre o consumo médio per capita de grelhado/brasa/churrasco e fritos entre as regiões brasileiras, sendo mais evidente quando desagregado por variáveis sócio demográficas.

Dynamic regulation of ARGONAUTE4 within multiple nuclear bodies in Arabidopsis thaliana.

DNA methylation directed by 24-nucleotide small RNAs involves the small RNA-binding protein ARGONAUTE4 (AGO4), and it was previously shown that AGO4 localizes to nucleolus-adjacent Cajal bodies, sites of snRNP complex maturation. Here we demonstrate that AGO4 also localizes to a second class of nuclear bodies, called AB-bodies, which are found immediately adjacent to condensed 45S ribosomal DNA (rDNA) sequences. AB-bodies also contain other proteins involved in RNA-directed DNA methylation including NRPD1b (a subunit of the RNA Polymerase IV complex, RNA PolIV), NRPD2 (a second subunit of this complex), and the DNA methyltransferase DRM2. These two classes of AGO4 bodies are structurally independent--disruption of one class does not affect the other--suggesting a dynamic regulation of AGO4 within two distinct nuclear compartments in Arabidopsis. Abolishing Cajal body formation in a coilin mutant reduced overall AGO4 protein levels, and coilin dicer-like3 double mutants showed a small decrease in DNA methylation beyond that seen in dicer-like3 single mutants, suggesting that Cajal bodies are required for a fully functioning DNA methylation system in Arabidopsis.

Fractal dimension, wavelet shrinkage and anomaly detection for mine hunting

An anomaly detection approach is considered for the mine hunting in sonar imagery problem. The authors exploit previous work that used dual-tree wavelets and fractal dimension to adaptively suppress sand ripples and a matched filter as an initial detector. Here, lacunarity inspired features are extracted from the remaining false positives, again using dual-tree wavelets. A one-class support vector machine is then used to learn a decision boundary, based only on these false positives. The approach exploits the large quantities of 'normal' natural background data available but avoids the difficult requirement of collecting examples of targets in order to train a classifier. © 2012 The Institution of Engineering and Technology.

Iris recognition algorithm based on point covering of high-dimensional space and neural network

In this paper, we constructed a Iris recognition algorithm based on point covering of high-dimensional space and Multi-weighted neuron of point covering of high-dimensional space, and proposed a new method for iris recognition based on point covering theory of high-dimensional space. In this method, irises are trained as "cognition" one class by one class, and it doesn't influence the original recognition knowledge for samples of the new added class. The results of experiments show the rejection rate is 98.9%, the correct cognition rate and the error rate are 95.71% and 3.5% respectively. The experimental results demonstrate that the rejection rate of test samples excluded in the training samples class is very high. It proves the proposed method for iris recognition is effective.

Application of multi-weighted neuron for iris recognition

In this paper, from the cognition science point of view, we constructed a neuron of multi-weighted neural network, and proposed a new method for iris recognition based on multi-weighted neuron. In this method, irises are trained as "cognition" one class by one class, and it doesn't influence the original recognition knowledge for samples of the new added class. The results of experiments show the correct rejection rate is 98.9%, the correct cognition rate and the error recognition rate are 95.71% and 3.5% respectively. The experimental results demonstrate that the correct rejection rate of the test samples excluded in the classes of training samples is very high. It proves the proposed method for iris recognition is effective.

Effects of La3+ and Gd3+ on Ca2+ influx in rat hepatoma H-35 cells

Effects of La3+ and Gd3+ on Ca2+ influx were investigated in rat hepatoma H-35 cells by measuring the initial rate of Ca-45(2+) uptake. It was found that the maximum initial rate of Ca2+ uptake was increased six- to ten-fold at low concentrations of La3+ and Gd3+. Kinetic analyses by measuring the initial rate of Ca2+ influx at different external Ca2+ concentrations indicated the existence of two intracellular exchangeable components in the basal Ca2+ system, with low and high affinities for Ca2+, and only one class of Ca2+ binding sites was observed in the La3+- or Gd3+-treated cells. For high affinity, La3+ and Gc(3+) increased both kinetic parameters K-m and V-max of basal Ca2+ influx. La3+ and Gd3+ compete directly with Ca2+ for Ca2+ binding site for low affinity. The kinetics is competitive.

滑坡泥石流信息遥感获取与空间预测

On the issue of geological hazard evaluation（GHE）, taking remote sensing and GIS systems as experimental environment, assisting with some programming development, this thesis combines multi-knowledges of geo-hazard mechanism, statistic learning, remote sensing (RS), high-spectral recognition, spatial analysis, digital photogrammetry as well as mineralogy, and selects geo-hazard samples from Hong Kong and Three Parallel River region as experimental data, to study two kinds of core questions of GHE, geo-hazard information acquiring and evaluation model. In the aspect of landslide information acquiring by RS, three detailed topics are presented, image enhance for visual interpretation, automatic recognition of landslide as well as quantitative mineral mapping. As to the evaluation model, the latest and powerful data mining method, support vector machine (SVM), is introduced to GHE field, and a serious of comparing experiments are carried out to verify its feasibility and efficiency. Furthermore, this paper proposes a method to forecast the distribution of landslides if rainfall in future is known baseing on historical rainfall and corresponding landslide susceptibility map. The details are as following: (a) Remote sensing image enhancing methods for geo-hazard visual interpretation. The effect of visual interpretation is determined by RS data and image enhancing method, for which the most effective and regular technique is image merge between high-spatial image and multi-spectral image, but there are few researches concerning the merging methods of geo-hazard recognition. By the comparing experimental of six mainstream merging methods and combination of different remote sensing data source, this thesis presents merits of each method ,and qualitatively analyzes the effect of spatial resolution, spectral resolution and time phase on merging image. (b) Automatic recognition of shallow landslide by RS image. The inventory of landslide is the base of landslide forecast and landslide study. If persistent collecting of landslide events, updating the geo-hazard inventory in time, and promoting prediction model incessantly, the accuracy of forecast would be boosted step by step. RS technique is a feasible method to obtain landslide information, which is determined by the feature of geo-hazard distribution. An automatic hierarchical approach is proposed to identify shallow landslides in vegetable region by the combination of multi-spectral RS imagery and DEM derivatives, and the experiment is also drilled to inspect its efficiency. (c) Hazard-causing factors obtaining. Accurate environmental factors are the key to analyze and predict the risk of regional geological hazard. As to predict huge debris flow, the main challenge is still to determine the startup material and its volume in debris flow source region. Exerting the merits of various RS technique, this thesis presents the methods to obtain two important hazard-causing factors, DEM and alteration mineral, and through spatial analysis, finds the relationship between hydrothermal clay alteration minerals and geo-hazards in the arid-hot valleys of Three Parallel Rivers region. (d) Applying support vector machine (SVM) to landslide susceptibility mapping. Introduce the latest and powerful statistical learning theory, SVM, to RGHE. SVM that proved an efficient statistic learning method can deal with two-class and one-class samples, with feature avoiding produce ‘pseudo’ samples. 55 years historical samples in a natural terrain of Hong Kong are used to assess this method, whose susceptibility maps obtained by one-class SVM and two-class SVM are compared to that obtained by logistic regression method. It can conclude that two-class SVM possesses better prediction efficiency than logistic regression and one-class SVM. However, one-class SVM, only requires failed cases, has an advantage over the other two methods as only "failed" case information is usually available in landslide susceptibility mapping. (e) Predicting the distribution of rainfall-induced landslides by time-series analysis. Rainfall is the most dominating factor to bring in landslides. More than 90% losing and casualty by landslides is introduced by rainfall, so predicting landslide sites under certain rainfall is an important geological evaluating issue. With full considering the contribution of stable factors (landslide susceptibility map) and dynamic factors (rainfall), the time-series linear regression analysis between rainfall and landslide risk mapis presented, and experiments based on true samples prove that this method is perfect in natural region of Hong Kong. The following 4 practicable or original findings are obtained: 1) The RS ways to enhance geo-hazards image, automatic recognize shallow landslides, obtain DEM and mineral are studied, and the detailed operating steps are given through examples. The conclusion is practical strongly. 2) The explorative researching about relationship between geo-hazards and alteration mineral in arid-hot valley of Jinshajiang river is presented. Based on standard USGS mineral spectrum, the distribution of hydrothermal alteration mineral is mapped by SAM method. Through statistic analysis between debris flows and hazard-causing factors, the strong correlation between debris flows and clay minerals is found and validated. 3) Applying SVM theory (especially one-class SVM theory) to the landslide susceptibility mapping and system evaluation for its performance is also carried out, which proves that advantages of SVM in this field. 4) Establishing time-serial prediction method for rainfall induced landslide distribution. In a natural study area, the distribution of landslides induced by a storm is predicted successfully under a real maximum 24h rainfall based on the regression between 4 historical storms and corresponding landslides.

北京中小学生创造性思维的发展以及十三年前后之比较

This study investigated the major characteristics of creative thinking development for the school children in Beijing with paper/pencil tests. The “Creative Thinking Test” was executed. The representative samples were two groups of students who came from the classes in 3rd-grade to 12th-grade of normal schools in Beijing. The classes were selected at random, one grade one class. One group is composed of 387 students (218 males, 169 females) in 1993, the other is composed of 420 students (181 males, 239 females) in 2006. According to the data analysis, the major characteristics and the changes over the 13 years of the development of creative thinking for student were explored and discussed. 1) The development trends of three types of creative thinking were all flexuous increase with grade moving up. The mean score of elementary school students was the lowest. And scores of junior high school students and senior high school students were significant higher than elementary school students’. 2) The most rapid increase occurred from the 5th grade to 6th grade. 3) Slumps occurred in the 7th grade in PNE curve and also in the 9th and 12th grades in TPC curves. There was no slump in FGA curve. 4) The girl’s scores in PNE and TPC tests were significant better than boys’. No obvious gender difference was found in FGA test. 5) The scores of three creative thinking tests in 2006 were all better than those in 1993. Separately, the scores of FGA and TPC tests in 2006 were significant higher than the corresponding scores in 1993, and no significant difference was found in two PNE tests. 6) There was no significant difference in the maximum scores of the three creative thinking tests between 2006 and 1993. 7) The most rapid developing period of three types of creative thinking in 2006 were the 5th grade and the 6th grade. The same period in 1993 was from the 7th grade to 9th grade. 8) In 1993, there is no significant gender difference for each creative thinking test. In 2006, PNE and TPC results had remarkable gender difference that girls were higher than boys. No significant gender difference was found in FGA tests.

El sociograma como instrumento de evaluación del clima de aula

La comprensión y el estudio de las relaciones entre el alumnado en las aulas es fundamental, tanto para lograr una satisfactoria convivencia escolar como para evitar la violencia, el acoso escolar o bullying. Por ello es conveniente conocer la estructura informal de los alumnos dentro de la clase, identificando los grupos que se forman y sus dinámicas de exclusión y liderazgo. Para poder intervenir en un grupo social, el educador debe conocer a fondo las relaciones sociales que en él fluyen. En esta investigación, se describen las relaciones que hay en una clase de 6º de primaria del colegio Cardenal Ilundain, mostrando los diferentes grupos y subgrupos que existen en el aula y señalando qué sujetos ejercen el rol de líder y cuáles son rechazados. Para ello se ha elaborado un test sociométrico que nos permite conocer las relaciones, jerárquicas o no, del grupo-clase y realizar una serie de sociogramas que proporcionan una visión de las relaciones entre compañeros y muestran tanto el nivel de integración de cada alumno/a como los contextos en los que se relacionan. En el diseño del sociograma se han tenido en cuenta los resultados de algunas investigaciones sobre este tema, principalmente las investigaciones de Jacob Levy Moreno creador del sociograma

Differentiated Predictive Fair Service for TCP Flows

The majority of the traffic (bytes) flowing over the Internet today have been attributed to the Transmission Control Protocol (TCP). This strong presence of TCP has recently spurred further investigations into its congestion avoidance mechanism and its effect on the performance of short and long data transfers. At the same time, the rising interest in enhancing Internet services while keeping the implementation cost low has led to several service-differentiation proposals. In such service-differentiation architectures, much of the complexity is placed only in access routers, which classify and mark packets from different flows. Core routers can then allocate enough resources to each class of packets so as to satisfy delivery requirements, such as predictable (consistent) and fair service. In this paper, we investigate the interaction among short and long TCP flows, and how TCP service can be improved by employing a low-cost service-differentiation scheme. Through control-theoretic arguments and extensive simulations, we show the utility of isolating TCP flows into two classes based on their lifetime/size, namely one class of short flows and another of long flows. With such class-based isolation, short and long TCP flows have separate service queues at routers. This protects each class of flows from the other as they possess different characteristics, such as burstiness of arrivals/departures and congestion/sending window dynamics. We show the benefits of isolation, in terms of better predictability and fairness, over traditional shared queueing systems with both tail-drop and Random-Early-Drop (RED) packet dropping policies. The proposed class-based isolation of TCP flows has several advantages: (1) the implementation cost is low since it only requires core routers to maintain per-class (rather than per-flow) state; (2) it promises to be an effective traffic engineering tool for improved predictability and fairness for both short and long TCP flows; and (3) stringent delay requirements of short interactive transfers can be met by increasing the amount of resources allocated to the class of short flows.