A family of perfect hashing methods

Minimal perfect hash functions are used for memory efficient storage and fast retrieval of items from static sets. We present an infinite family of efficient and practical algorithms for generating order preserving minimal perfect hash functions. We show that almost all members of the family construct space and time optimal order preserving minimal perfect hash functions, and we identify the one with minimum constants. Members of the family generate a hash function in two steps. First a special kind of function into an r-graph is computed probabilistically. Then this function is refined deterministically to a minimal perfect hash function. We give strong theoretical evidence that the first step uses linear random time. The second step runs in linear deterministic time. The family not only has theoretical importance, but also offers the fastest known method for generating perfect hash functions.

Purification by reflux electrophoresis of whey proteins and of a recombinant protein expressed in Dictyostelium discoideum

Protein purification that combines the use of molecular mass exclusion membranes with electrophoresis is particularly powerful as it uses properties inherent to both techniques. The use of membranes allows efficient processing and is easily scaled up, while electrophoresis permits high resolution separation under mild conditions. The Gradiflow apparatus combines these two technologies as it uses polyacrylamide membranes to influence electrokinetic separations. The reflux electrophoresis process consists of a series of cycles incorporating a forward phase and a reverse phase. The forward phase involves collection of a target protein that passes through a separation membrane before trailing proteins in the same solution. The forward phase is repeated following clearance of the membrane in the reverse phase by reversing the current. We have devised a strategy to establish optimal reflux separation parameters, where membranes are chosen for a particular operating range and protein transfer is monitored at different pH values. In addition, forward and reverse phase times are determined during this process. Two examples of the reflux method are described. In the first case, we describe the purification strategy for proteins from a complex mixture which contains proteins of higher electrophoretic mobility than the target protein. This is a two-step procedure, where first proteins of higher mobility than the target protein are removed from the solution by a series of reflux cycles, so that the target protein remains as the leading fraction. In the second step the target protein is collected, as it has become the leading fraction of the remaining proteins. In the second example we report the development of a reflux strategy which allowed a rapid one-step preparative purification of a recombinant protein, expressed in Dictyostelium discoideum. These strategies demonstrate that the Gradiflow is amenable to a wide range of applications, as the protein of interest is not necessarily required to be the leading fraction in solution. (C) 1997 Elsevier Science B.V.

Temperament and character traits in patients with bipolar disorder and associations with comorbid alcoholism or anxiety disorders

Temperament and character traits may determine differences in clinical presentations and outcome of bipolar disorder. We compared personality traits in bipolar patients and healthy individuals using the Temperament and Character Inventory (TCI) and sought to verify whether comorbidity with alcoholism or anxiety disorders is associated with specific personality traits. Seventy-three DSM-IV bipolar patients were compared to 63 healthy individuals using the TCI. In a second step, the bipolar sample was subgrouped according to the presence of psychiatric comorbidity (alcoholism, n = 10; anxiety disorders; n = 23; alcoholism plus anxiety disorders, n = 21; no comorbidity, n = 19). Bipolar patients scored statistically higher than the healthy individuals on novelty seeking, harm avoidance and self-transcendence and lower on self-directedness and cooperativeness. Bipolar patients with only comorbid alcoholism scored statistically lower than bipolar patients without any comorbidity on persistence. Bipolar patients with only comorbid anxiety disorders scored statistically higher on harm avoidance and lower on self-directedness than bipolar patients without any comorbidity. Limitations of this study include the cross-sectional design and the small sample size, specifically in the analysis of the subgroups. However, our results suggest that bipolar patients exhibit a different personality structure than healthy individuals and that presence of psychiatric comorbidity in bipolar disorder is associated with specific personality traits. These findings suggest that personality, at least to some extent, mediates the comorbidity phenomena in bipolar disorder. (C) 2007 Elsevier Ltd. All rights reserved.

Human GC-AG alternative intron isoforms with weak donor sites show enhanced consensus at acceptor exon positions

It has been previously observed that the intrinsically weak variant GC donor sites, in order to be recognized by the U2-type spliceosome, possess strong consensus sequences maximized for base pair formation with U1 and U5/U6 snRNAs. However, variability in signal strength is a fundamental mechanism for splice site selection in alternative splicing. Here we report human alternative GC-AG introns (for the first time from any species), and show that while constitutive GC-AG introns do possess strong signals at their donor sites, a large subset of alternative GC-AG introns possess weak consensus sequences at their donor sites. Surprisingly, this subset of alternative isoforms shows strong consensus at acceptor exon positions 1 and 2. The improved consensus at the acceptor exon can facilitate a strong interaction with U5 snRNA, which tethers the two exons for ligation during the second step of splicing. Further, these isoforms nearly always possess alternative acceptor sites and always possess alternative acceptor sites and exhibit particularly weak polypyrimidine tracts characteristic of AG-dependent introns. The acceptor exon nucleotides are part of the consensus required for the U2AF(35)-mediated recognition of AG in such introns. Such improved consensus at acceptor exons is not found in either normal or alternative GT-AG introns having weak donor sites or weak polypyrimidine,tracts. The changes probably reflect mechanisms that allow GC-AG alternative intron isoforms to cope with two conflicting requirements, namely an apparent need for differential splice strength to direct the choice of alternative sites and a need for improved donor signals to compensate for the central mismatch base pair (C-A) in the RNA duplex of U1 snRNA and the pre-mRNA. The other important findings include (i) one in every twenty alternative introns is a GC-AG intron, and (ii) three of every five observed GC-AG introns are alternative isoforms.

A Hermeneutic Case Reconstruction of a published first-person narrative

Hermeneutic Case Reconstruction (Rosenthal, 1993) is a systematic method of analysing biographical self-presentations from an interpretivist perspective. The method consists of five major analytic steps. The first is an analysis of the biographical data that can stand independently of the narrator’s perspective. ‘Objective’ data is extracted from the text or interview transcript and ordered chronologically. Secondly, a thematic field analysis is undertaken in which the data is divided into separate units according to the type of text used, whilst keeping the sequence of these texts units intact. In this step, hypotheses are developed regarding the potential significance of the style and sequence of the events presented. The product of this second step is a reconstruction of the life story. A reconstruction of the life history then follows as the third step. The purpose of this step is to generate hypotheses about the meanings that biographical experiences might have had for the narrator at the time they occurred, given the sociocultural context in which they occurred. In the fourth step, microanalysis of individual text segments is undertaken, in which all hypotheses generated in the earlier steps are tested against the text for support or refutation. The final step consists of a contrastive comparison of the life history and life story. The life story and life history are compared to determine, for example, which aspects of the narrator’s experience have been emphasised or minimised. Through this comparison, the selective process is highlighted. This is referred to as the case structure. This paper describes an application of this method to a published first-person narrative of a woman’s experiences of sustaining a brain injury in a motor vehicle accident.

Adsorption in slit-like pores of activated carbons: Improvement of the Horvath and Kawazoe method

Anew thermodynamic approach has been developed in this paper to analyze adsorption in slitlike pores. The equilibrium is described by two thermodynamic conditions: the Helmholtz free energy must be minimal, and the grand potential functional at that minimum must be negative. This approach has led to local isotherms that describe adsorption in the form of a single layer or two layers near the pore walls. In narrow pores local isotherms have one step that could be either very sharp but continuous or discontinuous benchlike for a definite range of pore width. The latter reflects a so-called 0 --> 1 monolayer transition. In relatively wide pores, local isotherms have two steps, of which the first step corresponds to the appearance of two layers near the pore walls, while the second step corresponds to the filling of the space between these layers. All features of local isotherms are in agreement with the results obtained from the density functional theory and Monte Carlo simulations. The approach is used for determining pore size distributions of carbon materials. We illustrate this with the benzene adsorption data on activated carbon at 20, 50, and 80 degreesC, argon adsorption on activated carbon Norit ROX at 87.3 K, and nitrogen adsorption on activated carbon Norit R1 at 77.3 K.

“Também queremos falar” : representações socias dos alunos de ensino médio acerca da política de cotas da UFES

Este estudo buscou conhecer as representações sociais de alunos do ensino médio acerca da política afirmativa de cotas da UFES. Ao escolher realizar esta investigação científica, optei trabalhar com a Teoria das Representações Sociais (TRS), justamente por se tratar de uma pesquisa de natureza qualitativa, permitindo compreender melhor esse conjunto de saberes sociais cotidianos, explicações e afirmações que se originam na vida diária desses alunos. Para coleta e análise dos dados elegi trabalhar com grupos focais e análise de conteúdo, por acreditar que se tratam de técnicas mais apropriadas pelo tempo hábil destinado a tal propósito e o caráter exploratório dessa investigação. Foram eleitos como campo de pesquisa três escolas que ofertam o ensino médio no município de Cachoeiro de Itapemirim. Sendo, respectivamente, uma da rede particular, uma estadual e uma federal. Apresentei também de forma introdutória os principais conceitos sistematizados por Serge Moscovici que serviram de coordenadas para a formulação da TRS. Em um segundo momento, faço um debate dialogado sobre as relações raciais no Brasil através de autores que tentaram interpretar a realidade de um país de passado escravista e patriarcal. Como resultado dos diálogos com alunos do ensino médio, percebi que as representações sociais desses estudantes estão ancorados a um conjunto de palavras ligadas a ideia de igualdade, mérito, preconceito pelas avessas, “medida tapa buraco”. Entretanto, alunos favoráveis às políticas de cotas utilizaram muito a palavra igualdade no sentido material da existência (econômico e social). Percebeu-se também diferenças significativas não somente de instituição para instituição, como uma diversidade muito grande de concepções dentro de uma mesma instituição de ensino. Exemplo disso foi encontrado no IFES de Cachoeiro de Itapemirim, onde a visão sobre as cotas do primeiro grupo pertencente à turma de informática se aproximou mais das representações sociais dos alunos da escola particular, enquanto que as concepções do segundo grupo do curso de eletromecânica se conectavam mais com as falas dos alunos de escola pública.

Visual Screening Competencies Questionnaire (VSCQ) and orthoptic practice

The identification of core competencies which are important for undertaking accurate visual screening by orthoptists is considered in this study. The aim was to construct and validate a questionnaire for orthoptists to assess visual screening competency. This study comprised three steps. The first step involved a 69-item self-assessment questionnaire constructed to assess orthoptists' perception of their competencies in visual screening programs for children. This questionnaire was constructed with statements from the Orthoptic Benchmark Statement for Health Care Programmes (Quality Assurance Agency for Higher Education, UK) and included three competency dimensions: interpersonal (IP), instrumental (IT) and systemic (ST). The second step involved questionnaire translation.

O Impacto contabilistico da concentração de empresas: um estudo de caso

Dissertação para obtenção do Grau de Mestre em Contabilidade e Finanças Orientadores: Doutor José Manuel Veiga Pereira Professor Adjunto da área científica de Contabilidade, Grupo de disciplinas de Contabilidade Financeira Doutora Deolinda Maria Moreira Aparício Meira Professora Adjunta da área científica de Direito, Grupo de disciplinas de Direito Comercial

Exportar para a Europa de Leste: perspectivas económico-financeiras das empresas portuguesas

Dissertação de Mestrado em Finanças Empresariais

A novel framework for modeling value for the customer, an essay on negotiation

This paper proposes a novel framework for modelling the Value for the Customer, the so-called the Conceptual Model for Decomposing Value for the Customer (CMDVC). This conceptual model is first validated through an exploratory case study where the authors validate both the proposed constructs of the model and their relations. In a second step the authors propose a mathematical formulation for the CMDVC as well as a computational method. This has enabled the final quantitative discussion of how the CMDVC can be applied and used in the enterprise environment, and the final validation by the people in the enterprise. Along this research, we were able to confirm that the results of this novel quantitative approach to model the Value for the Customer is consistent with the company's empirical experience. The paper further discusses the merits and limitations of this approach, proposing that the model is likely to bring value to support not only the contract preparation at an Ex-Ante Negotiation Phase, as demonstrated, but also along the actual negotiation process, as finally confirmed by an enterprise testimonial.

Modelação e concepção da carroçaria do veículo eléctrico ecológico (VEECO)

Neste trabalho aborda-se o desenvolvimento da carroçaria do Veículo Eléctrico Ecológico – VEECO recorrendo a tecnologias assistidas por computador. Devido à impossibilidade de abranger toda a temática das tecnologias assistidas por computador, associadas ao desenvolvimento de uma carroçaria automóvel, o foco deste trabalho assenta no processo de obtenção de um modelo digital válido e no estudo do desempenho aerodinâmico da carroçaria. A existência de um modelo digital válido é a base de qualquer processo de desenvolvimento associado a tecnologias assistidas por computador. Neste sentido, numa primeira etapa, foram aplicadas e desenvolvidas técnicas e metodologias que permitem o desenvolvimento de uma carroçaria desde a sua fase de “design” até à obtenção de um modelo digital CAD. Estas abrangem a conversão e importação de dados, a realização de engenharia inversa, a construção/reconstrução CAD em CATIA V5 e a preparação/correcção de modelos CAD para a análise numérica. Numa segunda etapa realizou-se o estudo da aerodinâmica exterior da carroçaria, recorrendo à ferramenta de análise computacional de fluidos (CFD) Flow Simulation da CosmosFloworks integrado no programa SolidWorks 2010. Associado à temática do estudo aerodinâmico e devido à elevada importância da validação dos resultados numéricos por meio de dados experimentais, foi realizado o estudo de análise dimensional que permite a realização de ensaios experimentais à escala, bem como a análise dos resultados experimentais obtidos.

A aquisição da leitura e da escrita na Educação Pré-Escolar: estratégias de intervenção pedagógica

Mestrado, Educação Pré-Escolar e Ensino do 1º Ciclo do Ensino Básico, 3 de Julho de 2013, Universidade dos Açores (Relatório de Estágio).

Determinação dos impactes ambientais e análise do ciclo de vida da produção de biodiesel

O consumo de energia tem vindo a crescer de uma forma contínua e directamente proporcional ao aumento da população e da industrialização. A maior parte da energia consumida no Mundo é, ainda, proveniente dos combustíveis fósseis. Contudo, a diminuição da reserva e a poluição atmosférica produzida pela sua utilização, estimulam e aumentam a necessidade de fontes alternativas de energia. O biodiesel tem atraído considerável atenção como combustível renovável, biodegradável e não tóxico, e pode contribuir para a resolução do problema energético, reduzindo significativamente a emissão dos gases causadores do aquecimento global. A primeira etapa deste trabalho consistiu na simulação de diferentes alternativas de processos de produção de biodiesel. O método usado para a produção do biodiesel foi a transesterificação entre os óleos vegetais e um álcool, na presença de um catalisador. Entre as matérias-primas figuram os óleos de palma e os óleos alimentares usados que foram objecto de estudo nesta dissertação. Na segunda etapa realizou-se uma análise do ciclo de vida para todas as alternativas em estudo seguida de uma análise económica para as alternativas que apresentassem menores impactos e que fossem mais promissoras do ponto de vista económico. Por fim, procedeu-se à comparação das diferentes alternativas sob o ponto de vista da análise do ciclo de vida e sob o ponto de vista da análise económica. Comprovou-se a viabilidade de todos os processos e o biodiesel obtido apresentou boas especificações. Do ponto de vista da análise do ciclo de vida a melhor alternativa foi o processo de catálise alcalina com pré-tratamento ácido para óleos alimentares usados. O processo que usa como matérias-primas os óleos virgens, o metanol e o hidróxido de sódio apresenta, no entanto, menores custos de investimento. Contudo, o processo de catálise alcalina com pré-tratamento ácido cuja matéria-prima principal são os óleos usados é muito mais rentável e apresenta menores impactes ambientais.

Biofiltration of Air/Styrene and Air/Styrene/Acetone mixtures in a bubble column reactor

The goal of this work was the treatment of polluted waste gases in a bubble column reactor (BCR), in order to determinate the maximum value of reactor’s efficiency (RE), varying the inlet concentration (C in) of the pollutants. The gaseous mixtures studied were: (i) air with styrene and (ii) air with styrene and acetone. The liquid phase used to contain the biomass in the reactor was a basal salt medium (BSM), fundamental for the microorganisms’ development. The reactor used in this project consists of a glass column of 620mm height and inside diameter 75mm. In all essays there were continually measured: pH, dissolved oxygen and liquid’s temperature. Temperature and pH were controlled (T=24ºC, 7.0 ≤ pH ≤ 7.7). In all experiments the liquid volume (including the biomass) used in the reactor was kept constant (1.5L) as well as the total gas flowrate (1 L/min). Concerning the goal of the work, some parameters were calculated: the organic load (OL), removal efficiency (RE), elimination capacity (EC), biomass concentration (xf) and dry biomass concentration (Xdw). In a first series of experiments, the gas mixture used was air with styrene, varying its concentration from 191 mg.m-3 to 6500 mg.m-3.It was concluded that the RE maximum value (97%) was obtained for C in Sty = 4200 mg.m-3. For the maximum tested value of C in Sty, RE obtained was 20%. In a second step, the gaseous mixture included acetone, varying C in Sty between 225 mg.m-3 and 2659 mg.m-3 and C in Ac between 153mg.m-3 and 1389 mg.m-3. The aim of these tests was the determination of C in Ac for which RE was maximum, obtaining C in Ac = 750 mg.m-3. A third series of experiments was performed, in which C in Ac was maintained equal to that value and C in Sty was varied until higher values (5422 mg.m-3). RE maximum values obtained in this last series were 100% for styrene and 40% for acetone. One important conclusion is the fact that the microorganisms available degrade better styrene than acetone. On the ambit of this study, it was possible to identify the species available in biomass: Xanthobacter antotrophicus py2, Enterobacter aerogenes, Nocardia, Corynebacterium Spp., Rhodococcus rhodochrous e Pseudomonas Sp.