Cognitive style factors affecting database query performance

As end-user computing becomes more pervasive, an organization's success increasingly depends on the ability of end-users, usually in managerial positions, to extract appropriate data from both internal and external sources. Many of these data sources include or are derived from the organization's accounting information systems. Managerial end-users with different personal characteristics and approaches are likely to compose queries of differing levels of accuracy when searching the data contained within these accounting information systems. This research investigates how cognitive style elements of personality influence managerial end-user performance in database querying tasks. A laboratory experiment was conducted in which participants generated queries to retrieve information from an accounting information system to satisfy typical information requirements. The experiment investigated the influence of personality on the accuracy of queries of varying degrees of complexity. Relying on the Myers–Briggs personality instrument, results show that perceiving individuals (as opposed to judging individuals) who rely on intuition (as opposed to sensing) composed queries more accurately. As expected, query complexity and academic performance also explain the success of data extraction tasks.

Predicting the HER2 status of breast cancer from basic histopathology data: an analysis of 1500 breast cancers as part of the HER2000 International Study

The tests that are currently available for the measurement of overexpression of the human epidermal growth factor-2 (HER2) in breast cancer have shown considerable problems in accuracy and interlaboratory reproducibility. Although these problems are partly alleviated by the use of validated, standardised 'kits', there may be considerable cost involved in their use. Prior to testing it may therefore be an advantage to be able to predict from basic pathology data whether a cancer is likely to overexpress HER2. In this study, we have correlated pathology features of cancers with the frequency of HER2 overexpression assessed by immunohistochemistry (IHC) using HercepTest (Dako). In addition, fluorescence in situ hybridisation (FISH) has been used to re-test the equivocal cancers and interobserver variation in assessing HER2 overexpression has been examined by a slide circulation scheme. Of the 1536 cancers, 1144 (74.5%) did not overexpress HER2. Unequivocal overexpression (3+ by IHC) was seen in 186 cancers (12%) and an equivocal result (2+ by IHC) was seen in 206 cancers (13%). Of the 156 IHC 3+ cancers for which complete data was available, 149 (95.5%) were ductal NST and 152 (97%) were histological grade 2 or 3. Only 1 of 124 infiltrating lobular carcinomas (0.8%) showed HER2 overexpression. None of the 49 'special types' of carcinoma showed HER2 overexpression. Re-testing by FISH of a proportion of the IHC 2+ cancers showed that only 25 (23%) of those assessable exhibited HER2 gene amplification, but 46 of the 47 IHC 3+ cancers (98%) were confirmed as showing gene amplification. Circulating slides for the assessment of HER2 score showed a moderate level of agreement between pathologists (kappa 0.4). As a result of this study we would advocate consideration of a triage approach to HER-2 testing. Infiltrating lobular and special types of carcinoma may not need to be routinely tested at presentation nor may grade 1 NST carcinomas in which only 1.4% have been shown to overexpress HER2. Testing of these carcinomas may be performed when HER2 status is required to assist in therapeutic or other clinical/prognostic decision-making. The highest yield of HER2 overexpressing carcinomas is seen in the grade 3 NST subgroup in which 24% are positive by IHC. (C) 2003 Elsevier Science Ltd. All rights reserved.

Capillaries within compartments: Microvascular interpretation of dynamic positron emission tomography data

Measurement of exchange of substances between blood and tissue has been a long-lasting challenge to physiologists, and considerable theoretical and experimental accomplishments were achieved before the development of the positron emission tomography (PET). Today, when modeling data from modern PET scanners, little use is made of earlier microvascular research in the compartmental models, which have become the standard model by which the vast majority of dynamic PET data are analysed. However, modern PET scanners provide data with a sufficient temporal resolution and good counting statistics to allow estimation of parameters in models with more physiological realism. We explore the standard compartmental model and find that incorporation of blood flow leads to paradoxes, such as kinetic rate constants being time-dependent, and tracers being cleared from a capillary faster than they can be supplied by blood flow. The inability of the standard model to incorporate blood flow consequently raises a need for models that include more physiology, and we develop microvascular models which remove the inconsistencies. The microvascular models can be regarded as a revision of the input function. Whereas the standard model uses the organ inlet concentration as the concentration throughout the vascular compartment, we consider models that make use of spatial averaging of the concentrations in the capillary volume, which is what the PET scanner actually registers. The microvascular models are developed for both single- and multi-capillary systems and include effects of non-exchanging vessels. They are suitable for analysing dynamic PET data from any capillary bed using either intravascular or diffusible tracers, in terms of physiological parameters which include regional blood flow. (C) 2003 Elsevier Ltd. All rights reserved.

An EM-based Semi-Parametric Mixture Model Approach to the Regression Analysis of Competing-Risks Data

We consider a mixture model approach to the regression analysis of competing-risks data. Attention is focused on inference concerning the effects of factors on both the probability of occurrence and the hazard rate conditional on each of the failure types. These two quantities are specified in the mixture model using the logistic model and the proportional hazards model, respectively. We propose a semi-parametric mixture method to estimate the logistic and regression coefficients jointly, whereby the component-baseline hazard functions are completely unspecified. Estimation is based on maximum likelihood on the basis of the full likelihood, implemented via an expectation-conditional maximization (ECM) algorithm. Simulation studies are performed to compare the performance of the proposed semi-parametric method with a fully parametric mixture approach. The results show that when the component-baseline hazard is monotonic increasing, the semi-parametric and fully parametric mixture approaches are comparable for mildly and moderately censored samples. When the component-baseline hazard is not monotonic increasing, the semi-parametric method consistently provides less biased estimates than a fully parametric approach and is comparable in efficiency in the estimation of the parameters for all levels of censoring. The methods are illustrated using a real data set of prostate cancer patients treated with different dosages of the drug diethylstilbestrol. Copyright (C) 2003 John Wiley Sons, Ltd.

Effect of changing data collection parameters on statistical motor unit number estimates

The effect of number of samples and selection of data for analysis on the calculation of surface motor unit potential (SMUP) size in the statistical method of motor unit number estimates (MUNE) was determined in 10 normal subjects and 10 with amyotrophic lateral sclerosis (ALS). We recorded 500 sequential compound muscle action potentials (CMAPs) at three different stable stimulus intensities (10–50% of maximal CMAP). Estimated mean SMUP sizes were calculated using Poisson statistical assumptions from the variance of 500 sequential CMAP obtained at each stimulus intensity. The results with the 500 data points were compared with smaller subsets from the same data set. The results using a range of 50–80% of the 500 data points were compared with the full 500. The effect of restricting analysis to data between 5–20% of the CMAP and to standard deviation limits was also assessed. No differences in mean SMUP size were found with stimulus intensity or use of different ranges of data. Consistency was improved with a greater sample number. Data within 5% of CMAP size gave both increased consistency and reduced mean SMUP size in many subjects, but excluded valid responses present at that stimulus intensity. These changes were more prominent in ALS patients in whom the presence of isolated SMUP responses was a striking difference from normal subjects. Noise, spurious data, and large SMUP limited the Poisson assumptions. When these factors are considered, consistent statistical MUNE can be calculated from a continuous sequence of data points. A 2 to 2.5 SD or 10% window are reasonable methods of limiting data for analysis. Muscle Nerve 27: 320–331, 2003

Model-based clustering in gene expression microarrays: An application to breast cancer data

In microarray studies, the application of clustering techniques is often used to derive meaningful insights into the data. In the past, hierarchical methods have been the primary clustering tool employed to perform this task. The hierarchical algorithms have been mainly applied heuristically to these cluster analysis problems. Further, a major limitation of these methods is their inability to determine the number of clusters. Thus there is a need for a model-based approach to these. clustering problems. To this end, McLachlan et al. [7] developed a mixture model-based algorithm (EMMIX-GENE) for the clustering of tissue samples. To further investigate the EMMIX-GENE procedure as a model-based -approach, we present a case study involving the application of EMMIX-GENE to the breast cancer data as studied recently in van 't Veer et al. [10]. Our analysis considers the problem of clustering the tissue samples on the basis of the genes which is a non-standard problem because the number of genes greatly exceed the number of tissue samples. We demonstrate how EMMIX-GENE can be useful in reducing the initial set of genes down to a more computationally manageable size. The results from this analysis also emphasise the difficulty associated with the task of separating two tissue groups on the basis of a particular subset of genes. These results also shed light on why supervised methods have such a high misallocation error rate for the breast cancer data.

Zygosity Diagnosis in the Absence of Genotypic Data: An Approach Using Latent Class Analysis

For zygosity diagnosis in the absence of genotypic data, or in the recruitment phase of a twin study where only single twins from same-sex pairs are being screened, or to provide a test for sample duplication leading to the false identification of a dizygotic pair as monozygotic, the appropriate analysis of respondents' answers to questions about zygosity is critical. Using data from a young adult Australian twin cohort (N = 2094 complete pairs and 519 singleton twins from same-sex pairs with complete responses to all zygosity items), we show that application of latent class analysis (LCA), fitting a 2-class model, yields results that show good concordance with traditional methods of zygosity diagnosis, but with certain important advantages. These include the ability, in many cases, to assign zygosity with specified probability on the basis of responses of a single informant (advantageous when one zygosity type is being oversampled); and the ability to quantify the probability of misassignment of zygosity, allowing prioritization of cases for genotyping as well as identification of cases of probable laboratory error. Out of 242 twins (from 121 like-sex pairs) where genotypic data were available for zygosity confirmation, only a single case was identified of incorrect zygosity assignment by the latent class algorithm. Zygosity assignment for that single case was identified by the LCA as uncertain (probability of being a monozygotic twin only 76%), and the co-twin's responses clearly identified the pair as dizygotic (probability of being dizygotic 100%). In the absence of genotypic data, or as a safeguard against sample duplication, application of LCA for zygosity assignment or confirmation is strongly recommended.

Systematic characterization of mutations in yeast acetohydroxyacid synthase: Interpretation of herbicide-resistance data

Acetohydroxyacid synthase (AHAS, EC 4.1.3.18) catalyses the first step in branched-chain amino acid biosynthesis and is the target for sulfonylurea and imidazolinone herbicides, which act as potent and specific inhibitors. Mutants of the enzyme have been identified that are resistant to particular herbicides. However, the selectivity of these mutants towards various sulfonylureas and imidazolinones has not been determined systematically. Now that the structure of the yeast enzyme is known, both in the absence and presence of a bound herbicide, a detailed understanding of the molecular interactions between the enzyme and its inhibitors becomes possible. Here we construct 10 active mutants of yeast AHAS, purify the enzymes and determine their sensitivity to six sulfonylureas and three imidazolinones. An additional three active mutants were constructed with a view to increasing imidazolinone sensitivity. These three variants were purified and tested for their sensitivity to the imidazolinones only. Substantial differences are observed in the sensitivity of the 13 mutants to the various inhibitors and these differences are interpreted in terms of the structure of the herbicide-binding site on the enzyme.

The development of chromatography for the characterization of protein interactions: a personal perspective

This article reviews the progress of a personal endeavour to develop chromatography as a quantitative procedure for the determination of reaction stoichiometries and equilibrium constants governing protein interactions. As well as affording insight into an aspect of chromatography with which many protein chemists are unfamiliar, it shows the way in which minor adaptations of conventional chromatographic practices have rendered the technique one of the most powerful methods available for the characterization of interactions. That pathway towards quantification is followed from the introduction of frontal gel filtration for the study of protein self-association to the characterization of ligand binding by the biosensor variant of quantitative affinity chromatography.

Coleta de dados por computadores de m??o para censos de propor????es continentais

Para tornar a coleta e a consolida????o de dados mais ??geis e econ??micas, aumentando a seguran??a sobre os dados, o IBGE est?? realizando a Contagem da Popula????o e o Censo Agropecu??rio 2007 com alternativa tecnol??gica para uso de computadores de m??o ??? PDAs (Personal Digital Assistant). ?? uma inova????o mundial, pois nenhum pa??s, nessas dimens??es, j?? realizou tal opera????o. A a????o dispensa question??rios em papel, substitu??dos por perguntas na tela do PDA, equipado com GPS para localizar estabelecimentos agropecu??rios por coordenadas. O PDA substitui bolsa e grandes volumes em papel. O plano de cr??tica, para validar informa????es coletadas, ?? transformado em programa, rodando em tempo real no PDA, para detec????o e corre????o de dados inconsistentes durante a entrevista, o que antes s?? era poss??vel ap??s meses. Outro salto em efici??ncia ?? a transmiss??o direta dos dados para o banco de dados do IBGE (sem escanear ou digitar documentos), criando mais confiabilidade e intelig??ncia na etapa de coleta

Data Mart para apoio ?? capacita????o em gest??o de pol??ticas p??blicas voltado para uma Escola de Administra????o P??blica

Este trabalho consiste num estudo de caso que se destina ao desenvolvimento de um Data Mart que possibilite a Escola Nacional de Administra????o P??blica ??? ENAP conhecer o perfil e o panorama geral da situa????o funcional dos servidores p??blicos federais que se capacitaram na Escola nos ??ltimos 7 anos. O aplicativo foi desenvolvido cruzando o banco de dados do sistema gerenciador dos cursos ministrados pela ENAP, onde est??o armazenadas informa????es sobre os alunos capacitados, os cursos realizados, os resultados alcan??ados, o perfil dos docentes e demais informa????es relativas ??s atividades da Escola, com os dados gerados pelo Sistema Integrado de Administra????o de Recursos Humanos ??? SIAPE, cuja extra????o de dados foi direcionada para os registros sobre a situa????o funcional, cargos, carreiras, fun????es, ??rg??os e alguns dados pessoais dos alunos, servidores p??blicos federais que se encontram registrados no SIAPE

Abono Perman??ncia em uma institui????o federal de ensino superior: aplica????o e desdobramentos

A preocupa????o principal deste artigo ?? descrever a implementa????o do Abono Perman??ncia em uma Institui????o Federal de Ensino Superior e as implica????es que o mesmo acarretou a seus servidores e ?? pr??pria institui????o. O objetivo pretendido aqui n??o est?? em exaurir o assunto ent??o tratado, mas mostrar o quanto este pode ser importante, partindo do pressuposto de seu significado intr??nseco na motiva????o para o trabalho. O principal interessado no assunto ?? o servidor p??blico e este pode usufruir desse benef??cio dado sua idade para aposentar. Trata-se de uma pesquisa descritiva, cuja coleta foi atrav??s de entrevistas semi-estruturadas e individuais com funcion??rios que trabalham diretamente com os processos de Abono Perman??ncia, e tamb??m atrav??s de an??lise de documentos e observa????o direta dos sistemas gerenciais de processos administrativos da institui????o. Este estudo contribui nas discuss??es sobre benef??cios sociais na Gest??o de Pessoas e a utiliza????o desses recursos na Administra????o P??blica. Pode-se concluir que o Abono Perman??ncia traz diversas contribui????es como, por exemplo, a motiva????o pessoal em continuar trabalhando, por??m, apresenta algumas limita????es no pr??prio incentivo ao benef??cio, que pode n??o ser interessante em determinados tetos salariais.

Ocupa????o no setor p??blico: tend??ncias recentes e quest??es em aberto

Com base neste trabalho, poder-se-ia hoje afirmar com maior seguran??a que: i) o movimento de recomposi????o de pessoal no setor p??blico brasileiro, observado durante toda a primeira d??cada de 2000, mostrou-se apenas suficiente para repor praticamente o mesmo estoque de servidores ativos existentes em meados da d??cada de 1990; ii) tampouco se deduz dos dados analisados que os gastos com pessoal tenham sa??do do controle do governo federal, pois, em termos percentuais, essa rubrica permaneceu praticamente constante ao longo da primeira d??cada de 2000, em um contexto de retomada relativa do crescimento econ??mico e tamb??m da arrecada????o tribut??ria; e iii) do ponto de vista qualitativo, evid??ncias da pesquisa indicam que esse movimento atual deve trazer melhorias gradativas ao desempenho institucional, pois vem sendo promovido a partir de crit??rios meritocr??ticos de sele????o (concursos p??blicos), e diante disso as atividades-fim, que exigem n??vel superior de escolariza????o, s??o mais contempladas do que as atividades-meio, indicando a possibilidade de maiores impactos sobre a produtividade agregada do setor p??blico; e tem assumido a forma de vincula????o estatut??ria, em detrimento do padr??o celetista ou de v??rias formas de contrata????o prec??rias, o que coloca o novo contingente sob direitos e deveres comuns e est??veis, podendo com isso gerar maior coes??o e homogeneidade no interior da categoria como um todo, aspecto considerado essencial para um desempenho satisfat??rio do Estado a longo prazo.

Cursos abiertos en l??nea:?? un escenario para la gesti??n personal del conocimiento?

A partir de uma discuss??o dos antecedentes e caracter??sticas dos cursos on-line, este artigo descreve uma solu????o tecnol??gica de apoio ?? realiza????o deste tipo de curso, baseada no uso de ferramentas p??blicas e de uso gratuito(isto ??, que n??o requerem instala????o em um servidor pr??prio). Esta ?? uma prova de conceito que busca evidenciar as possibilidades e obst??culos associados ?? oferta deste tipo de pr??tica educativa em um contexto latino-americano.