The appearance of a second genotype of Japanese encephalitis virus in the Australasian region

In mid-January 2000, the reappearance of Japanese encephalitis (JE) virus activity in the Australasian region was first demonstrated by the isolation of JE virus from 3 sentinel pigs on Badu Island in the Torres Strait. Further evidence of JE virus activity was revealed through the isolation of JE virus from Cidex gelidus mosquitoes collected on Badu Island and the detection of specific JE virus neutralizing antibodies in 3 pigs from Saint Pauls community on Moa Island. Nucleotide sequencing and phylogenetic analyses of the premembrane and envelope genes were performed which showed that both the pig and mosquito JE virus isolates (TSOO and TS4152, respectively) clustered in genotype I, along with northern Thai, Cambodian, and Korean isolates. All previous Australasian JE virus isolates belong to genotype II, along with Malaysian and Indonesian isolates. Therefore, for the first time, the appearance and transmission of a second genotype of JE virus in the Australasian region has been demonstrated.

The cloning and characterization of a second alpha-amylase of A-hydrophila JMP636

Aims: The aim of this study was to identify, clone and characterize the second amylase of Aeromonas hydrophila JMP636, AmyB, and to compare it to AmyA. Methods and Results: The amylase activity of A. hydrophila JMP636 is encoded by multiple genes. A second genetically distinct amylase gene, amyB, has been cloned and expressed from its own promoter in Escherichia coli. AmyB is a large alpha-amylase of 668 amino acids. Outside the conserved domains of alpha-amylases there is limited sequence relationship between the two alpha-amylases of A. hydrophila JMP636 AmyA and AmyB. Significant (80%) similarity exists between amyB and an alpha-amylase of A. hydrophila strain MCC-1. Differences in either the functional properties or activity under different environmental conditions as possible explanations for multiple copies of amylases in JMP636 is less likely after an examination of several physical properties, with each of the properties being very similar for both enzymes (optimal pH and temperature, heat instability). However the reaction end products and substrate specificity did vary enough to give a possible reason for the two enzymes being present. Both enzymes were confirmed to be alpha-type amylases. Conclusions: AmyB has been isolated, characterized and then compared to AmyA. Significance and Impact of Study: The amylase phenotype is rarely encoded by more than one enzyme within one strain, this study therefore allows the better understanding of the unusual amylase production by A. hydrophila.

Analysis of the sequence and expression of a second putative acetylcholinesterase cDNA from organophosphate-susceptible and organophosphate-resistant cattle ticks

The cattle tick, Boophilus microplus, is a major pest of cattle in Australia, Central and South America, and parts of Africa and Asia. Control of ticks with organophosphates (OPs) and carbamates, which target acetylcholinesterases (AChE), led to evolution of resistance to these pesticides. Alleles at the locus studied here, AChE2, from OP-susceptible female ticks from Australia and Mexico differed at 46 of 1689 nucleotide positions (20 putative amino acid differences) whereas alleles from three strains of OP-resistant ticks from Australia differed with the allele from the Australian susceptible ticks at six to 13 nucleotide positions (three to six putative amino acid differences). However, the role, if any, of these polymorphisms in the OP-resistance phenotype is unknown. Certainly none of the polymorphisms correspond to sites in ACK that are involved in catalysis or binding of acetylcholine in other organisms. Both of the AChE loci of B. microplus, AChE1 and AChE2, are apparently expressed in synganglia; AChE1 is also expressed in salivary glands and ovaries, in OP-susceptible and OP-resistant ticks. This seems to contradict studies of enzyme kinetics, which indicated that only one form of AChE was present in the synganglia, the site of the action of OPs, in this species of tick. (C) 2002 Elsevier Science Ltd. All rights reserved.

Basis set convergence in Hartree-Fock calculations of some diatomic molecules containing first and second-row atoms

Investiga-se a convergência de conjuntos de bases em direção ao limite numérico da energia Hartree-Fock (HF) total para as seqüências hierárquicas dos conjuntos de bases XZP e ccpVXZ. Para as duas hierarquias, melhoramentos significativos são obtidos com cada incremento em X. Para estimar o limite do conjunto de base completo, uma forma exponencial foi usada. Entre as várias aproximações consideradas aqui, uma extrapolação exponencial de três parâmetros aplicada aos resultados TZP, QZP e 5ZP deu os limites do conjunto de bases mais precisos. Em adição, energias HF dos orbitais moleculares ocupados mais altos de algumas moléculas diatômicas foram calculadas com o conjunto 5ZP e comparadas com as correspondentes obtidas com o conjunto cc-pV5Z e com um método numérico HF.

Automatic delimitation of the clinical region of interest in ultra-wide field of view images of the retina

Retinal ultra-wide field of view images (fundus images) provides the visu-alization of a large part of the retina though, artifacts may appear in those images. Eyelashes and eyelids often cover the clinical region of interest and worse, eye-lashes can be mistaken with arteries and/or veins when those images are put through automatic diagnosis or segmentation software creating, in those cases, the appearance of false positives results. Correcting this problem, the first step in the development of qualified auto-matic diseases diagnosis programs can be done and in that way the development of an objective tool to assess diseases eradicating the human error from those processes can also be achieved. In this work the development of a tool that automatically delimitates the clinical region of interest is proposed by retrieving features from the images that will be analyzed by an automatic classifier. This automatic classifier will evaluate the information and will decide which part of the image is of interest and which part contains artifacts. The results were validated by implementing a software in C# language and validated through a statistical analysis. From those results it was confirmed that the methodology presented is capable of detecting artifacts and selecting the clin-ical region of interest in fundus images of the retina.

El paludismo en Córdoba desde la segunda mitad del siglo XIX hasta la primera mitad del XX. The paludism in Córdoba from the second half of XIXth century to the first half of XXth century.

A pesar de que en los últimos años los estudios sobre historia y sociología de la Salud y la Enfermedad han experimentado un salto cualitativo, se ha soslayado sistemáticamente el análisis del paludismo y los complejos entramados de poder que subyacen a su presencia en los Departamentos del Noroeste y -en menor medida- en los del Oeste de la provincia de Córdoba. Nos referimos específicamente a la presencia de la endemia en los departamentos de Cruz del Eje, San Javier, San Alberto, Minas y Pocho. Con el propósito de redimensionar un comportamiento endemoepidémico que en esas localidades de Córdoba se remontó -según exploraciones provisionales- a mediados del siglo XIX, se construyen problemáticas que cobran sentido al ingresar en el terreno de los proyectos político-estatales nacionales, provinciales y de las mismas localidades afectadas, y, en lo que refiere a la articulación de las respuestas sanitarias frente a una enfermedad de profundas connotaciones ligadas al desarrollo socioeconómico y político de las regiones en estudio. En ese sentido en una primera instancia se articulará un análisis demográfico de la presencia y distribucion de la enfermedad a partir del trabajo con datos de corte estadistíco, elaborando mapas, cuadros y gráficos de morbimortalidad. Convergentemente se realizará un análisis hermenéutico de fuentes históricas del período en estudio. A grandes rasgos se considera que en relación al impacto del paludismo en bastas zonas del interior de la provincia de Córdoba y en cuanto a la acción sanitaria de los aparatos de poder estatal, desde mediados del siglo XIX, hasta la importante reducción de casos nuevos de paludismo a mediados del XX, pueden determinarse dos etapas sucesivas: Una primera se podría datar desde mediados del siglo XIX hasta mediados de la década de 1930, en la que actúa un Estado Nacional liberal que se desentendía de los problemas sanitarios de la regiones dejando esa función en manos de las provincias afectadas. Un segundo momento, aunque delimitado provisionalmente entre mediados de la década del 30' y mediados de la década del 50', se halla complejizado en su definición al combinarse en él procesos políticos particulares de la esfera nacional y de la provincial. Por un lado, en el plano nacional se ha observado desde la historiografía del período que, a partir de la década del 40' comienza a manifestarse una acción estatal nacional progresivamente centralizada y dispuesta a combatir la enfermedad con instituciones que podían llegar a todos los sectores sociales y a todas las regiones geográficas, aunque en menor medida a las zonas extra-pampeanas.Paralelamente, al considerar esos años en la esfera provincial se debe analizar el impacto de las formulaciones e intervenciones del radicalismo sabattinista como matriz política contraria al gobierno conservador nacional y promotor de un nuevo modelo de Estado en el que ocuparían un lugar privilegiado las políticas orientadas a la "cuestión social" y a la Salud en particular. Por otro lado, cobra significación una cuestión poco reconocida en los estudios en materia de politica sanitaria: los planes del peronismo combinaron una política centralizada en materia de dirección con una descentralización en el área de la ejecución.Finalmente dentro de este complejo marco político sanitario, se debe atender a lo largo de las dos etapas delimitadas, al universo de las iniciativas articuladas desde las autoridades de las localidades afectadas por el paludismo, así como, a las iniciativas civiles ya sea de vecinos, Sociedades de Beneficencia y asociadas a la Iglesia Católica.De acuerdo a la perspectiva asumida se propone recuperar una significativa problemática de marginalidad socioeconómica de las regiones, procurando reconstruir el impacto sociodemográfico del paludismo en el Noroeste y Oeste de la provincia de Córdoba ingresando al analisis histórico de las construcciones del poder público y privado en ese contexto local.

When is the second local multiplier algebra of a C*-algebra equal to the first?

We discuss necessary as well as sufficient conditions for the second iterated local multiplier algebra of a separable C*-algebra to agree with the first.

New trends in world wine consumption and its impact on the Spanish wineries during the second half of the twentieth century

The main goal of this research is explain the impact of the new trends of wine consumption, and the way these enterprises adapted to the circumstances. The hypothesis is that the Spanish companies had to start a deep and traumatic restructuring process, with the aim of surviving adequately in the changeable wine national and international markets. Heavy technological investments were made, with serious finance problems, during the eighties and nineties. We will see this from two specific cases, the Cooperatives "San Isidro" and "Rosario", located in the Region of Murcia, in the Spanish southeast.

Isochorismate synthase (PchA), the first and rate-limiting enzyme in salicylate biosynthesis of Pseudomonas aeruginosa.

In Pseudomonas aeruginosa the extracellular metabolite and siderophore pyochelin is synthesized from two major precursors, chorismate and l-cysteine via salicylate as an intermediate. The regulatory role of isochorismate synthase, the first enzyme in the pyochelin biosynthetic pathway, was studied. This enzyme is encoded by pchA, the last gene in the pchDCBA operon. The PchA protein was purified to apparent electrophoretic homogeneity from a PchA-overexpressing P. aeruginosa strain. The native enzyme was a 52-kDa monomer in solution, and its activity strictly depended on Mg(2+). At pH 7.0, the optimum, a K(m) = 4.5 microm and a k(cat) = 43.1 min(-1) were determined for chorismate. No feedback inhibitors or other allosteric effectors were found. The intracellular PchA concentration critically determined the rate of salicylate formation both in vitro and in vivo. In cultures grown in iron-limiting media to high cell densities, overexpression of the pchA gene resulted in overproduction of salicylate as well as in enhanced pyochelin formation. From this work and earlier studies, it is proposed that one important factor influencing the flux through the pyochelin biosynthetic pathway is the PchA concentration, which is determined at a transcriptional level, with pyochelin acting as a positive signal and iron as a negative signal.

The second internal transcribed spacer of nuclear ribosomal DNA as a tool for Latin American anopheline taxonomy: a critical review

Among the molecular markers commonly used for mosquito taxonomy, the internal transcribed spacer 2 (ITS2) of the ribosomal DNA is useful for distinguishing among closely-related species. Here we review 178 GenBank accession numbers matching ITS2 sequences of Latin American anophelines. Among those, we found 105 unique sequences corresponding to 35 species. Overall the ITS2 sequences distinguish anopheline species, however, information on intraspecific and geographic variations is scarce. Intraspecific variations ranged from 0.2% to 19% and our analysis indicates that misidentification and/or sequencing errors could be responsible for some of the high values of divergence. Research in Latin American malaria vector taxonomy profited from molecular data provided by single or few field capture mosquitoes. However we propose that caution should be taken and minimum requirements considered in the design of additional studies. Future studies in this field should consider that: (1) voucher specimens, assigned to the DNA sequences, need to be deposited in collections, (2) intraspecific variations should be thoroughly evaluated, (3) ITS2 and other molecular markers, considered as a group, will provide more reliable information, (4) biological data about vector populations are missing and should be prioritized, (5) the molecular markers are most powerful when coupled with traditional taxonomic tools.

Intragenomic variation in the second internal transcribed spacer of the ribosomal DNA of species of the genera Culex and Lutzia (Diptera: Culicidae)

Culex is the largest genus of Culicini and includes vectors of several arboviruses and filarial worms. Many species of Culex are morphologically similar, which makes their identification difficult, particularly when using female specimens. To aid evolutionary studies and species distinction, molecular techniques are often used. Sequences of the second internal transcribed spacer (ITS2) of ribosomal DNA (rDNA) from 16 species of the genus Culex and one of Lutzia were used to assess their genomic variability and to verify their applicability in the phylogenetic analysis of the group. The distance matrix (uncorrected p-distance) that was obtained revealed intragenomic and intraspecific variation. Because of the intragenomic variability, we selected ITS2 copies for use in distance analyses based on their secondary structures. Neighbour-joining topology was obtained with an uncorrected p-distance. Despite the heterogeneity observed, individuals of the same species were grouped together and correlated with the current, morphology-based classification, thereby showing that ITS2 is an appropriate marker to be used in the taxonomy of Culex.