A new species of mudfish, Neochanna (Teleostei: Galaxidae), from northern New Zealand

A new species of mudfish, Neochanna, is described from Northland. Neochanna heleios n.sp. is known from only three ephemeral wetland sites on the Kerikeri volcanic plateau and is abundant only at the type locality. The new species has a head resembling that of the brown mudfish, Neochanna apoda, and a caudal region resembling that of the black mudfish, Neochanna diversus. It can be distinguished from all Neochanna species in having a reduced number of principal caudal fin rays (13 or less). Morphometric and meristic comparisons with N. apoda and N. diversus are provided

Current Challenges in Financing Agricultural Cooperatives

Agricultural, Cooperatives, Finance, Agribusiness, L10, L23, L16, Q13,

MCCORNACK AND BROWN: BENLATE POSTHARVEST FUNGICIDE 235 BENLATE, AN EXPERIMENTAL POSTHARVEST CITRUS FUNGICIDE

Abstract Benlate (DuPont 1991) has provided ou

Antiresonances in Molecular Wires

We present analytic and numerical studies based on Landauer theory of conductance antiresonances of molecular wires. Our analytic treatment is a solution of the Lippmann-Schwinger equation for the wire that includes the effects of the non-orthogonality of the atomic orbitals on different atoms exactly. The problem of non-orthogonality is treated by solving the transport problem in a new Hilbert space which is spanned by an orthogonal basis. An expression is derived for the energies at which antiresonances should occur for a molecular wire connected to a pair of single-channel 1D leads. From this expression we identify two distinct mechanisms that give rise to antiresonances under different circumstances. The exact treatment of non-orthogonality in the theory is found to be necessary to obtain reliable results. Our numerical simulations extend this work to multichannel leads and to molecular wires connected to 3D metallic nanocontacts. They demonstrate that our analytic results also provide a good description of these more complicated systems provided that certain well-defined conditions are met. These calculations suggest that antiresonances should be experimentally observable in the differential conductance of molecular wires of certain types.Comment: 22 pages, 5 figure

Molecular typing of mycobacterium tuberculosis by using nine novel variable-number tandem repeats across the Beijing family and low-copy-number IS6110 isolates

Molecular epidemiological tools for genotyping clinical isolates of Mycobacterium tuberculosis have been developed and used to help track and contain transmission of tuberculosis. We identified 87 short sequence repeat loci within the genome of the M. tuberculosis H37Rv strain. Nine tandem repeats were found to be variable (variable-number tandem repeats (VNTRs)) in a set of 91 isolates. Fifty-seven of the isolates had only four IS6110 bands. The other 34 isolates were members of the Beijing strain family. The number of alleles of each these nine VNTRs was determined by examining each isolate. Six of the loci (Mtb-v1, -v4, -v10, -v15, -v18, and -v20) were able to differentiate the Beijing spoligotype identical isolates into seven distinct genotypes. Five of the loci (Mtb-v3, -v5, -v6, -v10, and -v15) were informative in discriminating the four-band IS6110 restriction fragment length polymorphism isolates from each other. The Nei's diversity values of each marker ranged from 0.02 to 0.59, with the number of alleles ranging from two to eight across the entire strain set. These nine loci provide a useful, discriminatory extension of VNTR typing methods for application to molecular epidemiologic studies of M. tuberculosis

Electron Standing Wave Formation in Atomic Wires

Using the Landauer formulation of transport theory and tight binding models of the electronic structure, we study electron transport through atomic wires that form 1D constrictions between pairs of metallic nano-contacts. Our results are interpreted in terms of electron standing waves formed in the atomic wires due to interference of electron waves reflected at the ends of the atomic constrictions. We explore the influence of the chemistry of the atomic wire-metal contact interfaces on these standing waves and the associated transport resonances by considering two types of atomic wires: gold wires attached to gold contacts and carbon wires attached to gold contacts. We find that the conductance of the gold wires is roughly $1 G_0 = 2 e^2/h$ for the wire lengths studied, in agreement with experiments. By contrast, for the carbon wires the conductance is found to oscillate strongly as the number of atoms in the wire varies, the odd numbered chains being more conductive than the even numbered ones, in agreement with previous theoretical work that was based on a different model of the carbon wire and metal contacts.Comment: 14 pages, includes 6 figure

Current-Driven Conformational Changes, Charging and Negative Differential Resistance in Molecular Wires

We introduce a theoretical approach based on scattering theory and total energy methods that treats transport non-linearities, conformational changes and charging effects in molecular wires in a unified way. We apply this approach to molecular wires consisting of chain molecules with different electronic and structural properties bonded to metal contacts. We show that non-linear transport in all of these systems can be understood in terms of a single physical mechanism and predict that negative differential resistance at high bias should be a generic property of such molecular wires.Comment: 9 pages, 4 figure

Traffic-related pollution (NO2 and CO) and its association with asthma symptoms among 10-11 year old children in Malaysia

Introduction: Children attending schools located close to major traffic sources are exposed to higher indoor air pollution levels due to infiltration of outdoor air pollutants. This study investigates the respiratory health of Malaysian schoolchildren in relation to indoor air pollution in schools and at home. Methods: This cross-sectional study was conducted among 2,164 schoolchildren aged 10-11 years in 35 urban and semi-rural schools in Kuala Lumpur Negeri Sembilan. Parents completed the International Study of Asthma and Allergy in Childhood questionnaire and provided information on the home environment and socio demographic background. Concentrations of NO2 and CO were measured indoors and outdoors of 14 schools. Results: The mean (standard deviation (SD)) indoor exposure to concentrations of air pollutants measured in Malaysian schools were: 42.9 (8.77) μg/m3 of NO2 and 3.16 (2.47) ppm of CO in urban schools and 12.4 (8.79) μg/m3 of NO2 and 0.33 (0.18) ppm of CO respectively for semi-rural schools. The prevalence of asthma was significantly higher among urban compared to semi-rural children. Ever wheeze was more common in urban areas (14.3%) compared to semi-rural areas (10.6%) as was current wheeze (urban 9.1%; semi-rural 6.2%), nocturnal cough (urban 12.0%; semi-rural 7.2%) and most other symptoms. The 3 main predictors of nocturnal cough were the presence of a current smoker at home (OR 1.97; 95% CI: 1.31-2.96), the absence of exhaust system in the kitchen (OR 1.67; 95% CI: 1.03-2.68) and the use of air conditioning (OR 3.10; 95% CI: 1.37-5.71). Self-reported asthma was predicted by the occupation of mothers; managerial positions (OR 1.78; 95% CI: 1.21-2.62), mothers working in the armed forces (OR 1.92; 95% CI: 1.32- 2.78) and fathers with a high school level of education (OR 0.46; 95% CI: 0.26- 0.82) while exposure to SHS of ≥4 hours per day (OR 2.53; 95% CI: 1.55-4.14) explained approximately 6.0% of the likelihood of reporting doctor-diagnosed asthma. Conclusion: This study has identified that many Malaysian schoolchildren experience exposure to air pollution indoors that exceeds WHO guidance limits for NO2 pollution but did not exceed the RMAQG levels. Considering that traffic-related sources largely contribute towards NO2 concentrations, compliance with the standards is not indicative of the reduced health risks for air pollution exposures