One size doesn't fit all: Research methodologies in a language variation study of Sudanese teens

The research reported here draws on a study of five teenagers from a Dinka-speaking community of Sudanese settling in Australia. A range of factors including language proficiency, social network structure and language attitudes are examined as possible causes for the variability of language use. The results and discussion illustrate how the use of a triangular research approach captured the complexity of the participants' language situation and was critical to developing a full understanding of the interplay of factors influencing the teens' language maintenance and shift in a way that no single method could. Further, it shows that employment of different methodologies allowed for flexibility in data collection to ensure the fullest response from participants. Overall, this research suggests that for studies of non-standard communities, variability in research methods may prove more of a strength that the use of standardised instruments and approaches.

Spectral properties of the tandem Jackson network, seen as a quasi-birth-and-death process

Quasi-birth-and-death (QBD) processes with infinite “phase spaces” can exhibit unusual and interesting behavior. One of the simplest examples of such a process is the two-node tandem Jackson network, with the “phase” giving the state of the first queue and the “level” giving the state of the second queue. In this paper, we undertake an extensive analysis of the properties of this QBD. In particular, we investigate the spectral properties of Neuts’s R-matrix and show that the decay rate of the stationary distribution of the “level” process is not always equal to the convergence norm of R. In fact, we show that we can obtain any decay rate from a certain range by controlling only the transition structure at level zero, which is independent of R. We also consider the sequence of tandem queues that is constructed by restricting the waiting room of the first queue to some finite capacity, and then allowing this capacity to increase to infinity. We show that the decay rates for the finite truncations converge to a value, which is not necessarily the decay rate in the infinite waiting room case. Finally, we show that the probability that the process hits level n before level 0 given that it starts in level 1 decays at a rate which is not necessarily the same as the decay rate for the stationary distribution.

Prediction of MHC class II-binding peptides using an evolutionary algorithm and artificial neural network

Motivation: Prediction methods for identifying binding peptides could minimize the number of peptides required to be synthesized and assayed, and thereby facilitate the identification of potential T-cell epitopes. We developed a bioinformatic method for the prediction of peptide binding to MHC class II molecules. Results: Experimental binding data and expert knowledge of anchor positions and binding motifs were combined with an evolutionary algorithm (EA) and an artificial neural network (ANN): binding data extraction --> peptide alignment --> ANN training and classification. This method, termed PERUN, was implemented for the prediction of peptides that bind to HLA-DR4(B1*0401). The respective positive predictive values of PERUN predictions of high-, moderate-, low- and zero-affinity binder-a were assessed as 0.8, 0.7, 0.5 and 0.8 by cross-validation, and 1.0, 0.8, 0.3 and 0.7 by experimental binding. This illustrates the synergy between experimentation and computer modeling, and its application to the identification of potential immunotheraaeutic peptides.

An object-oriented neural network approach to short-term traffic forecasting

This paper discusses an object-oriented neural network model that was developed for predicting short-term traffic conditions on a section of the Pacific Highway between Brisbane and the Gold Coast in Queensland, Australia. The feasibility of this approach is demonstrated through a time-lag recurrent network (TLRN) which was developed for predicting speed data up to 15 minutes into the future. The results obtained indicate that the TLRN is capable of predicting speed up to 5 minutes into the future with a high degree of accuracy (90-94%). Similar models, which were developed for predicting freeway travel times on the same facility, were successful in predicting travel times up to 15 minutes into the future with a similar degree of accuracy (93-95%). These results represent substantial improvements on conventional model performance and clearly demonstrate the feasibility of using the object-oriented approach for short-term traffic prediction. (C) 2001 Elsevier Science B.V. All rights reserved.

Inter-subband redundancy prediction using neural network for video coding

High performance video codec is mandatory for multimedia applications such as video-on-demand and video conferencing. Recent research has proposed numerous video coding techniques to meet the requirement in bandwidth, delay, loss and Quality-of-Service (QoS). In this paper, we present our investigations on inter-subband self-similarity within the wavelet-decomposed video frames using neural networks, and study the performance of applying the spatial network model to all video frames over time. The goal of our proposed method is to restore the highest perceptual quality for video transmitted over a highly congested network. Our contributions in this paper are: (1) A new coding model with neural network based, inter-subband redundancy (ISR) prediction for video coding using wavelet (2) The performance of 1D and 2D ISR prediction, including multiple levels of wavelet decompositions. Our result shows a short-term quality enhancement may be obtained using both 1D and 2D ISR prediction.

Refolding and purification of the human secreted group IID phospholipase A(2) expressed as inclusion bodies in Escherichia coli

The secreted phospholipases A(2) (sPLA(2)s) are water-soluble enzymes that bind to the surface of both artificial and biological lipid bilayers and hydrolyze the membrane phospholipids. The tissue expression pattern of the human group IID secretory phospholipase A(2) (hsPLA(2)-IID) suggests that the enzyme is involved in the regulation of the immune and inflammatory responses. With an aim to establish an expression system for the hsPLA(2)-IID in Escherichia coli, the DNA-coding sequence for hsPLA(2)-IID was subcloned into the vector pET3a, and expressed as inclusion bodies in E. coli (BL21). A protocol has been developed to refold the recombinant protein in the presence of guanidinium hydrochloride, using a size-exclusion chromatography matrix followed by dilution and dialysis to remove the excess denaturant. After purification by cation-exchange chromatography, far ultraviolet circular dichroism spectra of the recombinant hsPLA(2)-IID indicated protein secondary structure content similar to the homologous human group IIA secretory phospholipase A(2). The refolded recombinant hsPLA(2)-IID demonstrated Ca(2+)-dependent hydrolytic activity, as measuring the release free fatty acid from phospholipid liposomes. This protein expression and purification system may be useful for site-directed mutagenesis experiments of the hsPLA(2)-IID which will advance our understanding of the structure-function relationship and biological effects of the protein. (C) 2009 Elsevier Inc. All rights reserved.

Centrifugal processing of cell debris and inclusion bodies from recombinant Escherichia coli

The settling characteristics of cell debris and inclusion bodies prior to, and following, fractionation in a disc-stack centrifuge were measured using Cumulative Sedimentation Analysis (CSA) and Centrifugal Disc photosedimentation (CDS). The impact of centrifuge feedrate and repeated homogenisation on both cell debris and inclusion body collection efficiency was investigated. Increasing the normalised centrifuge feedrate (Q/Sigma) from 1.32 x 10(-9) m s(-1) to 3.97 x 10(-9) m s(-1) leads to a 36% increase in inclusion body paste purity. Purity may also be improved by repeated homogenisation. Increasing the number of homogeniser passes results in smaller cell debris size whilst leaves inclusion body size unaltered. At a normalised centrifuge feedrate of 2.65 x 10(-9) m s(-1), increasing the number of homogeniser passes from two (2) to ten (10) improved overall inclusion body paste purity by 58%. Grade-efficiency curves for both the cell debris and inclusion bodies have also been generated in this study. The data are described using an equation developed by Mannweiler (1989) with parameters of k = 0.15-0.26 and n = 2.5-2.6 for inclusion bodies, and k = 0.12-0.14 and n = 2.0-2.2 for cell debris. This is the first accurate experimentally-determined grade efficiency curve for cell debris. Previous studies have simply estimated debris grade efficiency curves using an approximate debris size distribution and grade efficiency curves determined with 'ideal particles' (e.g. spherical PVA particles). The findings of this study may be used to simulate and optimise the centrifugal fractionation of inclusion bodies from cell debris.

Variation in Body Composition Determines Long-Term Blood Pressure Changes in Pre-Hypertension The MONICA/KORA (Monitoring Trends and Determinants on Cardiovascular Diseases/Cooperative Research in the Region of Augsburg) Cohort Study

Objectives We studied the relationship between changes in body composition and changes in blood pressure levels. Background The mechanisms underlying the frequently observed progression from pre-hypertension to hypertension are poorly understood. Methods We examined 1,145 subjects from a population-based survey at baseline in 1994/1995 and at follow-up in 2004/2005. First, we studied individuals pre-hypertensive at baseline who, during 10 years of follow-up, either had normalized blood pressure (PreNorm, n = 48), persistently had pre-hypertension (PrePre, n = 134), or showed progression to hypertension (PreHyp, n = 183). In parallel, we studied predictors for changes in blood pressure category in individuals hypertensive at baseline (n = 429). Results After 10 years, the PreHyp group was characterized by a marked increase in body weight (+5.71% [95% confidence interval (CI): 4.60% to 6.83%]) that was largely the result of an increase in fat mass (+17.8% [95% CI: 14.5% to 21.0%]). In the PrePre group, both the increases in body weight (+1.95% [95% CI: 0.68% to 3.22%]) and fat mass (+8.09% [95% CI: 4.42% to 11.7%]) were significantly less pronounced than in the PreHyp group (p < 0.001 for both). The PreNorm group showed no significant change in body weight (-1.55% [95% CI: -3.70% to 0.61%]) and fat mass (+0.20% [95% CI: -6.13% to 6.52%], p < 0.05 for both, vs. the PrePre group). Conclusions After 10 years of follow-up, hypertension developed in 50.1% of individuals with pre-hypertension and only 6.76% went from hypertensive to pre-hypertensive blood pressure levels. An increase in body weight and fat mass was a risk factor for the development of sustained hypertension, whereas a decrease was predictive of a decrease in blood pressure. (J Am Coll Cardiol 2010; 56: 65-76) (C) 2010 by the American College of Cardiology Foundation

Articular Cartilage in the Knee: Current MR Imaging Techniques and Applications in Clinical Practice and Research

Magnetic resonance (MR) imaging is the most important imaging modality for the evaluation of traumatic or degenerative cartilaginous lesions in the knee. It is a powerful noninvasive tool for detecting such lesions and monitoring the effects of pharmacologic and surgical therapy. The specific MR imaging techniques used for these purposes can be divided into two broad categories according to their usefulness for morphologic or compositional evaluation. To assess the structure of knee cartilage, standard spin-echo (SE) and gradient-recalled echo (GRE) sequences, fast SE sequences, and three-dimensional SE and GRE sequences are available. These techniques allow the detection of morphologic defects in the articular cartilage of the knee and are commonly used in research for semiquantitative and quantitative assessments of cartilage. To evaluate the collagen network and proteoglycan content in the knee cartilage matrix, compositional assessment techniques such as T2 mapping, delayed gadolinium-enhanced MR imaging of cartilage (or dGEMRIC), T1 rho imaging, sodium imaging, and diffusion-weighted imaging are available. These techniques may be used in various combinations and at various magnetic field strengths in clinical and research settings to improve the characterization of changes in cartilage. (C)RSNA, 2011 , radiographics.rsna.org

Managing youth transitions in the Network Society

Castells argues that society is being reconstituted according to the global logic of networks. This paper discusses the ways in which a globalised network logic transforms the nature young people's transitions from school to work. Furthermore, the paper explores the ways in which this network logic restructured the manner in which youth transitions are managed via the emergence of a Vocational Education and Training (VET) agenda in Australian post compulsory secondary schooling. It also notes the implications of the emergence of the 'network society' for locality generally and for selected localities specific to the research upon which this paper is based. It suggests that schools represent nodes in a range of VET and other networks, and shows how schools and other agencies in particular localities mobilise their expertise to construct such networks. These networks are networked, funded and regulated at various levels - regionally, nationally and globally. But, they are also facilitated by personal networking opportunities and capacities. The paper also points to the ways in which the 'reflexivity chances' of young people are shaped by this network logic - a situation that generates new forms of responsibility, for schools and teachers, with regard to the management of youth transitions.

Segmenting the market of West Australian senior tourists using an artificial neural network

Measuring perceptions of customers can be a major problem for marketers of tourism and travel services. Much of the problem is to determine which attributes carry most weight in the purchasing decision. Older travellers weigh many travel features before making their travel decisions. This paper presents a descriptive analysis of neural network methodology and provides a research technique that assesses the weighting of different attributes and uses an unsupervised neural network model to describe a consumer-product relationship. The development of this rich class of models was inspired by the neural architecture of the human brain. These models mathematically emulate the neurophysical structure and decision making of the human brain, and, from a statistical perspective, are closely related to generalised linear models. Artificial neural networks or neural networks are, however, nonlinear and do not require the same restrictive assumptions about the relationship between the independent variables and dependent variables. Using neural networks is one way to determine what trade-offs older travellers make as they decide their travel plans. The sample of this study is from a syndicated data source of 200 valid cases from Western Australia. From senior groups, active learner, relaxed family body, careful participants and elementary vacation were identified and discussed. (C) 2003 Published by Elsevier Science Ltd.

The tree cut and merge algorithm for estimation of network reliability

This article presents Monte Carlo techniques for estimating network reliability. For highly reliable networks, techniques based on graph evolution models provide very good performance. However, they are known to have significant simulation cost. An existing hybrid scheme (based on partitioning the time space) is available to speed up the simulations; however, there are difficulties with optimizing the important parameter associated with this scheme. To overcome these difficulties, a new hybrid scheme (based on partitioning the edge set) is proposed in this article. The proposed scheme shows orders of magnitude improvement of performance over the existing techniques in certain classes of network. It also provides reliability bounds with little overhead.

Currículo e atendimento educacional especializado na educação infantil : possibilidades e desafios à inclusão escolar

Esta pesquisa teve como objetivo geral compreender a proposta/ prática curricular do Atendimento Educacional Especializado (AEE) na Sala de Recursos Multifuncionais (SRM) enquanto função complementar na educação da criança pequena com deficiência e Transtornos Globais do Desenvolvimento (TGD). Partimos das constatações de que, nas duas últimas décadas, documentos oficiais, assim como pesquisas na área, apontam a necessidade de um trabalho pedagógico inclusivo, que atenda às demandas e características dos diferentes sujeitos matriculados. Questionamos se a proposta e prática curricular complementar do AEE, por meio da SRM, têm contribuído para a inclusão da criança pequena, público alvo da educação especial, nas práticas pedagógicas da sala de aula comum? Teoricamente buscamos as contribuições da Abordagem Histórico-Cultural para compreender o desenvolvimento e aprendizagem da criança com deficiência, assim como procuramos a interlocução com os teóricos do currículo, entre os quais Sacristán. Como metodologia, utilizamos a pesquisa-ação colaborativo-crítico. O lócus da pesquisa foi um Centro de Educação Infantil, situado em Vitória/ES, com uma sala de recurso multifuncional, modelo proposto pelo Ministério da Educação (MEC). Os sujeitos participantes foram crianças de 3 a 7 anos matriculadas no Centro Municipal de Educação Infantil (CMEI) e encaminhadas para o AEE, na SRM (seis crianças surdas, sete crianças com manifestações de TGD e uma criança com Síndrome de Down); dois professores de educação especial da SRM (uma professora da área da área de Deficiência Intelectual (DI), uma professora bilíngue e um instrutor surdo); professores regentes do turno da manhã CMEI e dois pedagogos. Como perspectiva teórico-metodológica, optamos pela rede significações (Rossetti-Ferreira, 2004) que tem seus pressupostos fundamentados na teoria histórico-cultural, que compreende os processos de desenvolvimento humano como atos de significação constituídos por múltiplas interações estabelecidas social e culturalmente pelos sujeitos durante toda a vida. A organização e análise dos dados ocorreram por meio dos movimentos, cenários e atores; as práticas curriculares inclusivas na/da escola: a SRM e a sala de aula comum em seus encontros e desencontros; a preocupação com o desenvolvimento psicomotor da criança; o brincar versus a aquisição da leitura e escrita; o diálogo entre o currículo da SRM e a sala de aula comum e os encontros colaborativos com os professores de educação especial, com as pedagogas e com as professoras regentes do CMEI. Algumas considerações importantes se destacam, entre as quais: a falta de formação e desconhecimento por parte dos professores de educação especial sobre a proposta curricular da educação infantil e práticas pedagógicas descontextualizadas e fragmentadas desenvolvidas na SRM, que dificultam a ação complementar ao trabalho da classe comum. Para as professoras das salas de atividades o AEE é viável na escola de educação infantil, mas não somente na SRM, concordam que deve haver o atendimento educacional especializado no turno em que a criança esteja matriculada; que ele pode ajudar na inclusão da criança público alvo da educação especial, por meio de práticas sociais e culturais lúdicas, linguísticas e intelectuais. Concluímos que as professoras desejam um AEE dinâmico, interlocutor, que se movimente na escola como um todo.

Currículo e educação especial : as ações da escola a partir dos diálogos cotidianos

O estudo teve como objetivo investigar as ações constituídas por uma escola pública de Ensino Fundamental para o envolvimento de alunos com deficiência e com transtornos globais do desenvolvimento no currículo escolar. Contou com as contribuições teóricas de Boaventura de Sousa Santos, Michel de Certeau e Philippe Meirieu para uma discussão sociológica, filosófica e pedagógica das situações desencadeadas pela pesquisa. No campo do currículo, aproximou-se das teorizações de Silva, Moreira, Apple e Sacristán, dentre outros, por serem teóricos que analisam o trabalho com o conhecimento no contexto escolar. Já no campo da Educação Especial, dialogou com as produções de pesquisadores que postulam pela ideia de que o processo de inclusão escolar pressupõe acesso à escola, bem como permanência e a garantia do direito de apropriação dos conhecimentos socialmente produzidos. Como aporte teórico-metodológico, apoiou-se nos pressupostos da pesquisa-ação colaborativo-crítica que advoga pela possibilidade de, por meio da pesquisa científica, produzir conhecimento sobre a realidade social, promover mudanças nas situações desafiadoras e envolver os sujeitos pesquisados em processos de formação continuada em contexto. O trabalho de pesquisa foi realizado em uma escola de Ensino Fundamental, pertencente à Rede Pública Municipal de Ensino de Vila Velha/ES, envolvendo professores, pedagogos, dirigente escolar, responsáveis pelos discentes e alunos matriculados do 1º ao 6º ano do Ensino Fundamental. O processo de produção de dados se efetivou no período de julho de 2010 a julho de 2011. O pesquisador esteve três vezes por semana no campo de pesquisa, participando das intervenções em sala de aula, dos espaços para planejamento e formação continuada e também de momentos informais na entrada, recreio e saída dos alunos. Para o desenvolvimento do estudo, trabalhou-se com três frentes correlacionadas: a observação participante e a escuta dos discursos produzidos por alunos, professores, equipe técnico-pedagógica e responsáveis pelos discentes sobre o envolvimento dos estudantes com indicativos à Educação Especial no currículo escolar; a constituição de espaços de formação continuada, tomando os dados produzidos na primeira etapa do estudo como elementos de sustentação da dinâmica formativa; o acompanhamento das ações praticadas pela escola para envolvimento das necessidades educacionais dos alunos com indicativos à Educação Especial no currículo escolar, a partir das reflexões desencadeadas nos espaços de formação continuada. Como resultados, a pesquisa aponta a necessidade de advogar pela constituição de currículos escolares mais abertos para contemplar as necessidades de aprendizagem de alunos com comprometimentos físicos, psíquicos, intelectuais ou sensoriais. Esta pesquisa se distancia de lógicas que defendem a flexibilização curricular como um esvaziamento do currículo em nome das condições existenciais dos alunos. Entende que, entre o currículo escolar e a produção de conhecimentos pelos alunos com indicativos à Educação Especial, há uma pluralidade de situações que precisam ser problematizadas pela escola: a leitura produzida sobre a aprendizagem dos alunos; a falta de conhecimento sobre a sexualidade humana; os desafios presentes na relação família e escola; e os pressupostos da normalidade/anormalidade. Esses fatores podem se configurar como elementos que impedem que os alunos obtenham sucesso em sua jornada educativa, porém, em contrapartida, podem ser utilizados como questões a subsidiar espaços de formação continuada. O estudo aponta que, por meio de atitudes colaborativas e críticas entre os profissionais da escola, é possível articular ações que garantam o direito de aprender do estudante com deficiência e com transtornos globais do desenvolvimento na escola de ensino comum.