Consideram-se, neste trabalho, as dificuldades dos estudantes em relação à álgebra que podem estar associadas às especificidades do conhecimento algébrico, às questões de metodologia e didática do ensino e também ao desenvolvimento dos processos psíquicos do pensamento e da linguagem. Desta forma define-se como objeto de estudo as manifestações do pensamento e da linguagem algébrica dos estudantes. Entende-se que o pensamento e a linguagem são constituídos a partir da atividade humana (LEONTIEV, 1983), e enquanto funções psicológicas superiores (VIGOTSKI, 2001). As relações entre o pensamento e a linguagem se apresentam por meio de processos de generalização, abstração, formação de conceitos (formas de pensamento para Davídov); juízos, deduções e conceitos (formas de pensamento para Kopnin); por meio do raciocínio, elaboração e explicitação (conforme Prado Jr.); e nos estágios de desenvolvimento dos conceitos (sincréticos, complexos e conceitos conforme Vigotski). Também constituídos a partir da atividade humana, o pensamento e a linguagem algébrica são compreendidos a partir de seu movimento lógico-histórico. Tal compreensão nos faz retomar a pesquisa com os estudantes de 6ª série do ensino fundamental procurando por meio de situações-problema investigar as manifestações e peculiaridades do movimento do pensamento e da linguagem algébrica. As soluções coletivas, se constituíram em dados analisados segundo as categorias: qualidade do pensamento, qualidade da linguagem, o conceito de variável. Da análise decorrem as sínteses que nos indicam elementos que, em relação aos processos de pensamento e linguagem, podem estar na origem das dificuldades dos estudantes com o conteúdo algébrico. Entre estes elementos, destacamos: a necessidade de ações do professor que gerem nos estudantes o pensamento teórico; a pretensa linearidade do conhecimento aritmético para o algébrico; a preocupação com a formação dos conceitos, e não somente sua aplicação; e a compreensão do significado do simbolismo algébrico e dos conceitos a ele subjacentes. Ressaltamos, ainda, que reconhecer as manifestações do pensamento e da linguagem algébrica dos estudantes é elemento relevante a ser considerado pelos professores na organização do ensino de álgebra. / This work deals with the students difficulties about algebraic knowledge, which could be related to the specificities of algebra, to educational methodology and didactical matters, and also to language and thought psychological processes. Therefore, the subject of study is the students\' thoughts and their algebraic language. We understand that thought and language are constituted from human activity (LEONTIEV, 1983) as a higher psychological functions (VIGOTSKI, 2001). The connections between thought and language are shown by means of: generalization, abstraction, formation of concepts (as in Davídov); judgments, deductions and concepts (as in Kopnin); by means of the reasoning, elaboration and accurate presentation (as by Prado Jr); and in the formation stages of a concept - syncretic/complex/real concept (as in Vigotski). Also part of human activity, the thought and the language of algebra are understood by the means of \"logic-historical\" movement. Such understanding prompted our research with 6th graders using mathematical life situation problems to investigate the manifestations and peculiarities of the thought and the language of algebra. The cooperative made solutions were analyzed according to these categories: thought quality, language quality and the concept of variable. Within these analyses and data syntheses we come up with elements which, connected to the processes of thought and language, can be part of the origin of the students\' difficulties with the algebraic content. Inside these elements, we detach: the necessity of teacher\'s action that can generate among students the theoretical thought; the pretense linearity of arithmetical knowledge through algebraic one; the concerns about the construction of a concept and not only in its application; and understanding the algebraic symbolism and the underlying concepts. Finally, we believe that the recognition of the manifestations of thought and the language of algebra among the students is a relevant aspect to be considered by the teachers during the curriculum writing.

Imunodeficiência Comum Variável (ICV) é uma imunodeficiência primária de igual distribuição entre os sexos e que afeta crianças e adultos, caracterizada por hipogamaglobulinemia com susceptibilidade aumentada a infecções e ampla variedade de complicações não infecciosas, como autoimunidade, malignidade, hiperplasia linfoide, doenças gastrointestinais, dentre outras. Os objetivos deste estudo foram: avaliar as manifestações clínicas, infecciosas e não infecciosas, mais frequentes em portadores de ICV (antes e após início da terapia com reposição de imunoglobulina humana) acompanhados em ambulatórios de imunologia do Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto da Universidade de São Paulo (HCFMRP-USP), além dos níveis séricos de imunoglobulinas (IgG, IgA e IgM) ao diagnóstico, bem como as alterações quantitativas de células CD19+, CD3+CD4+, CD3+CD8+ e CD3-CD16+CD56+ desses pacientes. Neste estudo descritivo foram obtidas informações de pacientes com ICV acompanhados no HCFMRPUSP, através de registros de prontuários médicos. Foram avaliados 32 pacientes: 19 do sexo masculino e 13 do sexo feminino. A mediana da idade de início dos sintomas foi de 8,5 anos, com um pico de incidência precoce. O tempo médio de atraso para o diagnóstico foi de 7,7 anos. Todos os pacientes apresentaram infecções recorrentes, que levaram ao diagnóstico da ICV. As infecções mais frequentes foram as respiratórias, sendo que antes do diagnóstico as pneumonias foram as mais observadas (gerando, inclusive, grande número de internações) e durante o primeiro ano de uso regular da terapia de reposição com imunoglobulina humana as rinossinusites foram as que mais ocorreram. Houve redução na incidência de infecções após início do tratamento. Todos os pacientes apresentaram níveis séricos de IgG, IgA e IgM reduzidos ao diagnóstico, sendo que as medianas dos níveis séricos foram de 158 mg/dL, 10,15 mg/dL e 17 mg/dL, respectivamente. De 30 pacientes que haviam realizado imunofenotipagem, cerca de 73% apresentaram número absoluto reduzido de células CD19+ e 40% apresentaram número absoluto reduzido de linfócitos T CD4+. A relação CD4/CD8 foi invertida em aproximadamente 53% dos pacientes. Em 18 pacientes as células natural killer foram quantificadas e cerca de 56% deles apresentaram número absoluto reduzido. A maioria (97%) dos pacientes manifestou, no mínimo, uma comorbidade não infecciosa no tempo médio de seguimento de 8,2 anos, sendo que hiperplasia linfoide e doença pulmonar crônica foram as mais frequentes, cada uma ocorrendo em cerca de metade dos pacientes. O atraso para o diagnóstico da ICV foi importante, sugerindo que a presença de infecções recorrentes, especialmente do trato respiratório, deveria levar à investigação de deficiências de anticorpos, com dosagem de imunoglobulinas. Complicações não infecciosas foram extremamente comuns nesta casuística, ressaltando o amplo espectro clínico da doença. / Common variable immunodeficiency (CVID) is a primary immunodeficiency that is equally distributed between men and women and affects children and adults, characterized by hypogammaglobulinemia with increased susceptibility to infections and a wide variety of noninfectious complications such as autoimmunity, malignancy, lymphoid hyperplasia, gastrointestinal diseases, among others. The purposes of this study were to evaluate infectious and non-infectious clinical manifestations (before and after immunoglobulin replacement therapy) of CVID patients attended at immunology outpatient clinics of the Clinical Hospital of Ribeirão Preto Medical School - University of São Paulo (HCFMRP-USP), in addition to immunoglobulins (IgG, IgA and IgM) serum levels at diagnosis, as well as quantitative differences in CD19+, CD3+CD4+, CD3+CD8+ and CD3-CD16+CD56+ cells. In this descriptive study, data of CVID patients followed up at HCFMRP-USP were collected through medical records. Thirty-two patients were found: 19 males and 13 females. The median age of onset of symptoms was 8.5 years, with an early peak of incidence. The mean delay for diagnosis was 7.7 years. All patients had recurrent infections, which led to the diagnosis of CVID. The most frequent infections were respiratory tract infections. Pneumonias were more observed before the diagnosis (generating a large number of hospitalizations) and rhinosinusitis were more frequent during the first year under regular use of immunoglobulin replacement therapy. There was a reduction in the incidence of infections after initiation of treatment. All patients had low IgG, IgA and IgM serum levels (lower than the 3th percentile for age) at diagnosis and the median of serum levels were 158 mg/dL, 10.15 mg/dL and 17 mg/dL, respectively. Among 30 patients that had been immunophenotyped, approximately 73% had a reduced absolute number of CD19+ cells and 40% had a reduced absolute number of T CD4+ lymphocytes. The CD4/CD8 ratio was inverted in approximately 53% of the patients. Natural killer cells were quantified in 18 patients and about 56% of them had reduced absolute number. The majority (97%) of patients manifested at least one noninfectious comorbidity at a mean follow-up time of 8.2 years, with lymphoid hyperplasia and chronic lung disease being the most common, each occurring in about half of the patients. The delay for the diagnosis of CVID was important, suggesting that the presence of recurrent infections, especially of the respiratory tract, should lead to the investigation of antibody deficiencies with dosage of immunoglobulins. Noninfectious complications were extremely common in this series, highlighting the broad clinical spectrum of the disease.

Submitted by isabela.moljf@hotmail.com (isabela.moljf@hotmail.com) on 2017-06-29T14:40:18Z No. of bitstreams: 1 filiperodriguesvianna.pdf: 2477695 bytes, checksum: 7e55b9eb9b2d53b58522606533f2a699 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-08-08T12:02:06Z (GMT) No. of bitstreams: 1 filiperodriguesvianna.pdf: 2477695 bytes, checksum: 7e55b9eb9b2d53b58522606533f2a699 (MD5) / Made available in DSpace on 2017-08-08T12:02:06Z (GMT). No. of bitstreams: 1 filiperodriguesvianna.pdf: 2477695 bytes, checksum: 7e55b9eb9b2d53b58522606533f2a699 (MD5) Previous issue date: 2017-04-18 / Essa dissertação tem o objetivo de identificar e mensurar o efeito dos pares sobre o desempenho escolar, medido pela proficiência em testes de Português e Matemática, de alunos de 1ª à 4ª série do Ensino Fundamental, de escolas públicas e privadas participantes do Estudo Longitudinal Geração Escolar (GERES, 2005-2008). A base de dados do GERES acompanha alunos ao longo da primeira etapa do ensino fundamental e fornece, além das informações dos alunos, informações sobre escolas, professores e diretores. O estudo parte de um modelo linear onde o desempenho escolar dos alunos é explicado pelo desempenho médio de seu grupo de pares, além de características próprias e pela média das características de seu grupo. O método aplicado, proposto por Lee (2007) utiliza variações no tamanho dos grupos e desvios das características em relação à média para a identificação dos efeitos. Os resultados são obtidos pelo estimador de Mínimos Quadrados em Dois Estágios (2SLS), utilizando os instrumentos propostos por Bramoullé, Djebbari e Fortin (2009). As regressões foram feitas para cada etapa do GERES, com o intuito de verificar a evolução dos coeficientes ao longo do tempo. Além disso, comparam-se os resultados obtidos com o uso de uma amostra de dados em painel balanceada e uma base de dados não balanceada, em que se aproveita informações de alunos com informações faltantes através de uma correção proposta por Davezies et al. (2009). Seja usando a amostra balanceada, seja usando a amostra não balanceada, os resultados indicam que os alunos são negativamente impactados pelos pares que possuem desempenho escolar superior. As características contextuais do grupo de pares também exercem influência sobre o desempenho escolar, sendo o nível socioeconômico e o gênero dos alunos as características mais importantes. / This dissertation aims to identify and measure the peer effects on scholar performance of students, measured by proficiency in Portuguese and Mathematics tests, from 1st to 4th grades of public and private schools who attended the Estudo Longitudinal Geração Escolar (GERES, 2005-2008). The GERES database follows students throughout the first stage of elementary school and provides, apart from the students' information, data about schools, teachers and principals. The study starts from a linear model where the students' performance is explained by the average performance of his/her peer group, as well as his/her own characteristics and average characteristics of his/her group. The applied method - proposed by Lee (2007) - uses variations in the size of the groups and deviations of the characteristics from the mean as well, in order to identify the peer effects. The coefficients are estimated through the Two-Stage Least Squares (2SLS) estimator, using the instruments proposed by Bramoullé, Djebbari and Fortin (2009). The regressions consider each wave of the GERES to verify the change of the coefficients over time. Further, we compare the results between a balanced database with an unbalanced database, where the correction method follows Davezies et al. (2009). In both samples, the results show that the average performance of the peers negatively impacts student’s performances. The background characteristics of the peer group also influence school performance, specifically the socioeconomic level and the gender of the students.

A força de vendas ocupa papel importante no desempenho das organizações, e em especial naquelas do mercado industrial. As decisões que envolvem a gestão da força de vendas, principalmente as referentes à remuneração, revestem-se de importância, dado seu potencial impacto no desempenho desses profissionais. Esta dissertação, embasada na teoria da contingência, pressupõe que não há um sistema de remuneração ?ótimo ou ideal? e, sim, aquele que melhor se ajusta ao contexto e objetivos organizacionais. Deste modo, a efetividade da estratégia de remuneração depende da existência de ajuste a certos fatores contingenciais aos quais a organização está sujeita com potencial de afetar o sistema. O construto de estratégia de remuneração foi operacionalizado através do repertório de escolhas a disposição dos gestores que têm impacto no desempenho da organização e no uso efetivo de seus recursos humanos. Especificamente quanto à estratégia de remuneração de vendas, a composição da remuneração é uma das escolhas relevantes, por se tratar de escolha na qual reside grande variabilidade entre as empresas, eventualmente de mesmo setor, o que sugere ser fortemente influenciada por fatores contingenciais. Esta dissertação objetiva então, expandir o conhecimento acerca do sistema de remuneração da força de vendas, suas especificidades, escolhas estratégicas envolvidas e fatores contingenciais. Para responder ao problema de pesquisa, optou-se pela realização de estudo exploratório e pelo método qualitativo, mais especificamente pelo estudo de caso, para ampliar o conhecimento sobre o fenômeno estudado, com uso de entrevistas em profundidade semi-estruturadas para levantamento das informações. Sumariamente, as contingências culturais e relacionadas ao macro-ambiente e ao ambiente de negócios se mostraram relevantes nas escolhas corporativas de remuneração nos casos estudados, corroborando os pressupostos teóricos da teoria da contingência e da nova economia institucional. De outro lado, as contingências que afetam as decisões relativas à composição de remuneração são de todos os planos ? do macro-ambiente, do ambiente de negócios, do processo de vendas, papel e, provavelmente, do indivíduo. Alguns fatores se destacaram nas organizações pesquisadas: o grau de incerteza do mercado e do ambiente; a competitividade e estabilidade do mercado; à estratégia competitiva; o ciclo de vida da organização e a cultura organizacional; características do ciclo de vendas, autonomia e supervisão recebida. Pode-se concluir que as decisões relativas à composição devem partir de análise cuidadosa dos ambientes externo e interno, procurando-se observar o seu impacto na reconfiguração do papel da força de vendas. Os resultados apontam para possíveis pontos de atenção na tomada de decisão acerca de sistemas de remuneração de profissionais de vendas, tendo em vista a sua efetividade. / Sales force management presents an important strategic decision to many firms. It has been widely acknowledged that the compensation of the sales force may be used to enhance sales, control sales force activities and improve customer relationships.Despite the ackowledged importance of sales compensation, the literature on the topic is rather limited and esparse. Based on contingency theory, it is proposed that the effectiveness of the type of compensation cannot be adequately assessed without consideration of these factors. It is hypothesized that the effectiveness at realizing intended pay strategies depends significantly on the existence of a match between compensation strategies, organization and the environment. To date, vey little work has been done in development a contngency theory that ties the pay system to the organization`s operating objetives and strategies. This study seeks to expand the emerging compensation strategy literature and examines the various dimensions that may be used to study this construct. Compensation strategy is the repertoire of pay choices available to management, that may, under some conditions, have an impact on the organization`s performance and the effective use of its human resources. Pay mix (the split between fix and variable pay) was assumed to be the most important pay choice for the sales force. Besides that, pay mix is one of the pay strategies that presents great variability between the companies, even from the same economic sector, suggesting that it is influencied by contingency factors. Thus, this study adresses the following key research question: What are the contingency factors that moderate the pay choices (pay strategy)? The contingency fators were studied beyond two major categories: external environment and internal environment. To answer the proposed question, an empirical study was conducted. The study was employed was a case study methodology. Primary data was obtained by in deep interviews .The study offer empirical support for the contingency theory. In particular, macrolevel factors like uncertainly and risk, as well as organizational factors ? corporate culture seemed to be relevant for the corporate pay strategies. On the other hand, ?pay mix? was the pay choice that seems to be influencied by multi-level factors. Some factors appeared to have more influence in the pay mix choices in the searched organizations: the degree of uncertainty of the market and the environment; the competitiveness and stability of the market; the competitive strategy; the organization life cicle and culture; characteristics of the sales cycle autonomy and received supervision. It can be concluded that strategic decision on pay mix must take careful analysis on contingency factors related to external and internal environments, because they tend to shape the sales process and the sales force role. The findings suggests some possible points of attention in the decision concerning to compensation of sales force towards effectiveness and could help practitioners manage the relationship between reward processes and strategy in organization.

O objetivo central desta tese é demonstrar a existência de uma estrutura regenerativa visível para cadeias de alcance variável não limitadas. Também apresentamos um algoritmo de identificação de seqüências de instantes de regeneração que converge quase certamente quando o tamanho da amostra diverge. / Our main aim is prove the existence of a regeneration scheme in unbounded variable length chains. We present an algorithm to identify sequences of regeneration times which converges almost surely as the sample length.

Based on Ian Steedman's seminal contribution "Consumption Takes Time", we propose a formal activity-based model for consumer behaviour. The model simultaneously incorporates choices over consumption time, as well as quantities and qualities of products consumed. We identify and examine preconditions for satiation with products and draw implications for economic policy. Satiation with products explains the limited effects of price or income changes on demand and questions the pertinence of economic growth for development. It further highlights the relevance of working time reductions for well-being. (authors' abstract)

Abstract Multicarrier and multiple input–multiple output (MIMO) techniques have become popular in wireless communications over multipath fading channels in recent years. This thesis firstly considers the characterization and simulation of fading mobile radio channels for MIMO multicarrier systems. Secondly, the performance of spread-spectrum multicarrier (MC) code-division multiple-access (CDMA) with multirate transmission is analyzed. Thirdly, the analysis is applied to ultra-wideband (UWB) orthogonal frequency-division multiplexing (OFDM) systems enhanced with frequency-domain code-division multiplexing (CDM). The response of a small-scale fading channel is derived as a function of time, transmit and receive antenna positions, and subcarrier frequency, which leads to a tapped delay-line model with time-, space-, and frequency-selective taps. The taps are modeled as a sum of a deterministic line-of-sight or dominant scattered path and a zero-mean Gaussian part composed of a number of unresolvable scattered paths and, therefore, are Rice fading. The Gaussian parts have the desired temporal and spatiospectral correlations generated by time-correlation shaping filtering and a space-frequency correlation transformation, respectively. The simulator achieves a good accuracy while retaining a reasonable computational complexity. The generic performance analysis of MC-CDMA includes both the multicode and variable spreading factor (VSF) multirate schemes that are inherent for CDMA and capable of providing efficient support for services of different required data rates. The analysis also takes into account the intersymbol interference caused by the multipath delay components exceeding a guard interval, which is commonly omitted in the literature by assuming the guard interval to be longer than the maximum delay spread. Results comparing and pointing out notable differences in the error rate performance of the two multirate schemes in conjunction with six different combining techniques are presented for a synchronous downlink and both a synchronous and asynchronous uplink. The analysis of CDM-enhanced OFDM-UWB involves first a single piconet with different combinations of the VSF and multicode schemes. Frequency-domain spreading is found to improve the performance remarkably when a sufficient spreading factor and a suitable subcarrier combining method are used. Subsequently, CDMA of simultaneously operating piconets (SOPs) with either the VSF or multicode scheme is considered. While both multirate schemes result in a similar performance when the number of SOPs is large, notable differences arise when there are only a few SOPs.

We experimentally demonstrate an eight-state continuous-variable quantum key distribution (CV-QKD) over atmospheric turbulence channels. The high secret key rate (SKR) is enabled by 4-D multiplexing of 96 channels, i.e., six-channel wavelength-division multiplexing, four-channel orbital angular momentum multiplexing, two-channel polarization multiplexing, and two-channel spatial-position multiplexing. The atmospheric turbulence channel is emulated by a spatial light modulator on which a series of azimuthal phase patterns yielding Andrews' spectrum are recorded. A commercial coherent receiver is implemented at Bob's side, followed by a phase noise cancellation stage, where channel transmittance can be monitored accurately and phase noise can be effectively eliminated. Compared to four-state CV-QKD, eight-state CV-QKD protocol potentially provides a better performance by offering higher SKR, better excess noise tolerance, and longer secure transmission distance. In our proposed CV-QKD system, the minimum transmittances of 0.24 and 0.26 are required for OAM states of 2 (or -2) and 6 (or -6), respectively, to guarantee the secure transmission. A maximum SKR of 3.744 Gb/s is experimentally achievable, while a total SKR of 960 Mb/s can be obtained in case of mean channel transmittances.

This thesis describes an optimising compiler for translating from SMV to CLP(B). The optimisation is aimed at reducing the number of required variables in order to decrease the size of the resulting BDDs. Also a partitioning of the transition relation is performed. The compiler uses an internal representation of a FSM that is built up from the SMV description. A number of rewrite steps are performed on the problem description such as encoding to a Boolean domain and performing the optimisations. The variable reduction heuristic is based on finding sub-circuits that are suitable for reduction and a state space search is performed on those groups. An evaluation of the results shows that in some cases the compiler is able to greatly reduce the size of the resulting BDDs.

The increased online presence and use of technology by today’s adolescents has created new places where bullying can occur. The aim of this thesis is to specify a prediction model that can accurately predict the risk of cyberbullying victimization. The data used is from a survey conducted at five secondary schools in Pereira, Colombia. A logistic regression model with random effects is used to predict cyberbullying exposure. Predictors are selected by lasso, tuned by cross-validation. Covariates included in the study includes demographic variables, dietary habit variables, parental mediation variables, school performance variables, physical health variables, mental health variables and health risk variables such as alcohol and drug consumption. Included variables in the final model are demographic variables, mental health variables and parental mediation variables. Variables excluded in the final model includes dietary habit variables, school performance variables, physical health variables and health risk variables. The final model has an overall prediction accuracy of 88%.