Genetic organization of Pasteurella multocida cap Loci and development of a multiplex capsular PCR typing system

Current serotyping methods classify Pasteurella multocida into five capsular serogroups (serogroups A, B, D, E, and F) and 16 somatic serotypes (serotypes 1 to 16). In the present study, we have developed a multiplex PCR assay as a rapid alternative to the conventional capsular serotyping system. The serogroup-specific primers used in this assay were designed following identification, sequence determination, and analysis of the capsular biosynthetic loci of each capsular serogroup. The entire capsular biosynthetic loci of P. multocida A:1 (X-73) and B:2 (M1404) have been cloned and sequenced previously (J. Y. Chung, Y. M. Zhang, and B. Adler, FEMS Microbiol. Lett. 166:289-296, 1998; J. D. Boyce, J. Y. Chung, and B. Adler, Vet. Microbiol. 72:121-134, 2000). Nucleotide sequence analysis of the biosynthetic region (region 2) from each of the remaining three serogroups, serogroups D, E, and F, identified serogroup-specific regions and gave an indication of the capsular polysaccharide composition. The multiplex capsular PCR assay was highly specific, and its results, with the exception of those for some serogroup F strains, correlated well with conventional serotyping results. Sequence analysis of the strains that gave conflicting results confirmed the validity of the multiplex PCR and indicated that these strains were in fact capsular serogroup A. The multiplex PCR will clarify the distinction between closely related serogroups A and F and constitutes a rapid assay for the definitive classification of P. multocida capsular types

Complete DNA sequence and gene organization of the mitochondrial genome of the liverfluke, Fasciola hepatica L. (Platyhelminthes; Trematoda)

The complete nucleotide sequence of the mitochondrial (mt) DNA molecule of the liverfluke, Fasciola hepatica (phylum Platyhelminthes, class Trematoda, family Fasciolidae), was determined, It comprises 14462 bp, contains 12 protein-encoding, 2 ribosomal and 22 transfer RNA genes, and is the second complete flatworm (and the first trematode) mitochondrial sequence to be described in detail. All of the genes are transcribed from the same strand. Of the genes typically found in mitochondrial genomes of eumetazoans, only atp8 is absent. The nad4L and nad4 genes overlap by 40 nt. Most intergenic sequences are very short. Two larger non-coding regions are present. The longer one (817 nt) is located between trnG and cox3 and consists of 8 identical tandem repeats of 85 nt, rich in G and C, followed by 1 imperfect repeat. The shorter non-coding region (187 nt) exhibits no special features and is separated from the longer region by trnG. The gene arrangement resembles that of some other trematodes including the eastern Asian Schistosoma species (and cyclophyllidean cestode species) but it is strikingly different from that of the African schistosomes, represented by Schistosoma mansoni. The genetic code is as inferred previously for flatworms. Transfer RNA genes range in length from 58 to 70 nt, their products producing characteristic 'clover leaf' structures, except for tRNA(S-VON) and tRNA(S-AGN) lacking the DHU arm.

Protein targeting to the plasma membrane of adult skeletal muscle fiber: An organized mosaic of functional domains

The plasma membrane of differentiated skeletal muscle fibers comprises the sarcolemma, the transverse (T) tubule network, and the neuromuscular and muscle-tendon junctions. We analyzed the organization of these domains in relation to defined surface markers, beta -dystroglycan, dystrophin, and caveolin-3, These markers were shown to exhibit highly organized arrays along the length of the fiber. Caveolin-3 and beta -dystroglycan/dystrophin showed distinct, but to some extent overlapping, labeling patterns and both markers left transverse tubule openings clear. This labeling pattern revealed microdomains over the entire plasma membrane with the exception of the neuromuscular and muscle-tendon junctions which formed distinct demarcated macrodomains. Our results suggest that the entire plasma membrane of mature muscle comprises a mosaic of T tubule domains together with sareolemmal caveolae and beta -dystroglycan domains. The domains identified with these markers were examined with respect to targeting of viral proteins and other expressed domain-specific markers, We found that each marker protein was targeted to distinct microdomains, The macrodomains were intensely labeled with all our markers. Replacing the cytoplasmic tail of the vesicular stomatitis virus glycoprotein with that of CD4 resulted in retargeting from one domain to another. The domain-specific protein distribution at the muscle cell surface may be generated by targeting pathways requiring specific sorting information but this trafficking is different from the conventional apical-basolateral division. (C) 2001 Academic Press.

Efficient simulation of a Tandem Jackson Network

The two-node tandem Jackson network serves as a convenient reference model for the analysis and testing of different methodologies and techniques in rare event simulation. In this paper we consider a new approach to efficiently estimate the probability that the content of the second buffer exceeds some high level L before it becomes empty, starting from a given state. The approach is based on a Markov additive process representation of the buffer processes, leading to an exponential change of measure to be used in an importance sampling procedure. Unlike changes of measures proposed and studied in recent literature, the one derived here is a function of the content of the first buffer. We prove that when the first buffer is finite, this method yields asymptotically efficient simulation for any set of arrival and service rates. In fact, the relative error is bounded independent of the level L; a new result which is not established for any other known method. When the first buffer is infinite, we propose a natural extension of the exponential change of measure for the finite buffer case. In this case, the relative error is shown to be bounded (independent of L) only when the second server is the bottleneck; a result which is known to hold for some other methods derived through large deviations analysis. When the first server is the bottleneck, experimental results using our method seem to suggest that the relative error is bounded linearly in L.

Extensive vascularization of developing mouse ovaries revealed by caveolin-1 expression

Expression screening for genes preferentially expressed in mouse fetal ovaries relative to testes identified Cav-1 as a candidate female-specific gene. Cav-1 encodes caveolin-1, a component of the cell membrane invaginations known as caveolae, which are involved in lipid regulation and signal transduction. In situ hybridization revealed high levels of Cav-1 mRNA in developing ovaries, compared with moderate or low levels in testes. Analysis of caveolin-1 protein distribution by immunofluorescence showed this difference to be due to the development of a dense and complex vascular network in the developing ovary. These observations point to a higher degree of differentiation and organization of the early stage mammalian ovary than previously suspected. (C) 2002 Wiley-Liss, Inc.

Use of liquid phase adsorption for characterizing pore network connectivity in activated carbon

A simple percolation theory-based method for determination of the pore network connectivity using liquid phase adsorption isotherm data combined with a density functional theory (DFT)-based pore size distribution is presented in this article. The liquid phase adsorption experiments have been performed using eight different esters as adsorbates and microporous-mesoporous activated carbons Filtrasorb-400, Norit ROW 0.8 and Norit ROX 0.8 as adsorbents. The density functional theory (DFT)-based pore size distributions of the carbons were obtained using DFT analysis of argon adsorption data. The mean micropore network coordination numbers, Z, of the carbons were determined based on DR characteristic plots and fitted saturation capacities using percolation theory. Based on this method, the critical molecular sizes of the model compounds used in this study were also obtained. The incorporation of percolation concepts in the prediction of multicomponent adsorption equilibria is also investigated, and found to improve the performance of the ideal adsorbed solution theory (IAST) model for the large molecules utilized in this study. (C) 2002 Elsevier Science B.V. All rights reserved.

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.

Telehealth responses to bio-terrorism and emerging infections

Emerging infectious diseases, such as severe acute respiratory syndrome (SARS), are of huge economic importance. They are difficult to predict. The World Health Organization has a Global Outbreak Alert and Response Network, which was involved at an early stage in the SARS outbreak in 2003. Three major lessons were learned as a result of the SARS epidemic in 2003, involving communication, evidence-based action and global partnerships. It is proposed that a series of broadband global response networks should be developed. At a technical level the networks are essentially in place, such as the Internet2 global network. Suitable peripheral devices also exist. What has not yet been created is the appropriate software to allow the use of these networks, although a number of commercial products are in the process of development.

GLUT4 recycles via a trans-Golgi network (TGN) subdomain enriched in Syntaxins 6 and 16 but not TGN38: Involvement of an acidic targeting motif

Insulin stimulates glucose transport in fat and muscle cells by triggering exocytosis of the glucose transporter GLUT4. To define the intracellular trafficking of GLUT4, we have studied the internalization of an epitope-tagged version of GLUT4 from the cell surface. GLUT4 rapidly traversed the endosomal system en route to a perinuclear location. This perinuclear GLUT4 compartment did not colocalize with endosomal markers (endosomal antigen I protein, transferrin) or TGN38, but showed significant overlap with the TGN target (t)-soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) Syntaxins 6 and 16. These results were confirmed by vesicle immunoisolation. Consistent with a role for Syntaxins 6 and 16 in GLUT4 trafficking we found that their expression was up-regulated significantly during adipocyte differentiation and insulin stimulated their movement to the cell surface. GLUT4 trafficking between endosomes and trans-Golgi network was regulated via an acidic targeting motif in the carboxy terminus of GLUT4, because a mutant lacking this motif was retained in endosomes. We conclude that GLUT4 is rapidly transported from the cell surface to a subdomain of the trans-Golgi network that is enriched in the t-SNAREs Syntaxins 6 and 16 and that an acidic targeting motif in the C-terminal tail of GLUT4 plays an important role in this process.

GAIP participates in budding of membrane carriers at the trans-Golgi network

Galpha interacting protein (GAIP) is a regulator of G protein signaling protein that associates dynamically with vesicles and has been implicated in membrane trafficking, although its specific role is not yet known. Using an in vitro budding assay, we show that GAIP is recruited to a specific population of trans-Golgi network-derived vesicles and that these are distinct from coatomer or clathrin-coated vesicles. A truncation mutant (NT-GAIP) encoding only the N-terminal half of GAIP is recruited to trans -Golgi network membranes during the formation of vesicle carriers. Overexpression of NT-GAIP induces the formation of long, coated tubules, which are stabilized by microtubules. Results from the budding assay and from imaging in live cells show that these tubules remain attached to the Golgi stack rather than being released as carrier vesicles. NT-GAIP expression blocks membrane budding and results in the accumulation of tubular carrier intermediates. NT-GAIP-decorated tubules are competent to load vesicular stomatitis virus protein G-green fluorescent protein as post-Golgi, exocytic cargo and in cells expressing NT-GAIP there is reduced surface delivery of vesicular stomatitis virus protein G-green fluorescent protein. We conclude that GAIP functions as an essential part of the membrane budding machinery for a subset of post-Golgi exocytic carriers derived from the trans-Golgi network.

A reduced load approximation accounting for link interactions in a loss network

This paper is concerned with evaluating the performance of loss networks. Accurate determination of loss network performance can assist in the design and dimen- sioning of telecommunications networks. However, exact determination can be difficult and generally cannot be done in reasonable time. For these reasons there is much interest in developing fast and accurate approximations. We develop a reduced load approximation that improves on the famous Erlang fixed point approximation (EFPA) in a variety of circumstances. We illustrate our results with reference to a range of networks for which the EFPA may be expected to perform badly.

Effect of pore-network connectivity on multicomponent adsorption of large molecules

The effect of pore-network connectivity on binary liquid-phase adsorption equilibria using the ideal adsorbed solution theory (LAST) was studied. The liquid-phase binary adsorption experiments used ethyl propionate, ethyl butyrate, and ethyl isovalerate as the adsorbates and commercial activated carbons Filtrasorb-400 and Norit ROW 0.8 as adsorbents. As the single-component isotherm, a modified Dubinin-Radushkevich equation was used. A comparison with experimental data shows that incorporating the connectivity of the pore network and considering percolation processes associated with different molecular sizes of the adsorptives in the mixture, as well as their different corresponding accessibility, can improve the prediction of binary adsorption equilibria using the LAST Selectivity of adsorption for the larger molecule in binary systems increases with an increase in the pore-network coordination number, as well with an increase in the mean pore width and in the spread of the pore-size distribution.

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.