Sequence diversity in the coat protein coding region of the genome RNA of Johnsongrass mosaic virus in Australia

Sequence diversity in the coat protein coding region of Australian strains of Johnsongrass mosaic virus (JGMV) was investigated. Field isolates were sampled during a seven year period from Johnsongrass, sorghum and corn across the northern grain growing region. The 23 isolates were found to have greater than 94% nucleotide and amino acid sequence identity. The Australian isolates and two strains from the U.S.A. had about 90% nucleotide sequence identity and were between 19 and 30% different in the N-terminus of the coat protein. Two amino acid residues were found in the core region of the coat protein in isolates obtained from sorghum having the Krish gene for JGMV resistance that differed from those found in isolates from other hosts which did not have this single dominant resistance gene. These amino acid changes may have been responsible for overcoming the resistance conferred by the Krish gene for JGMV resistance in sorghum. The identification of these variable regions was essential for the development of durable pathogen-derived resistance to JGMV in sorghum.

Water quality in the Great Barrier Reef region: responses of mangrove, seagrass and macroalgal communities

Marine plants colonise several interconnected ecosystems in the Great Barrier Reef region including tidal wetlands, seagrass meadows and coral reefs. Water quality in some coastal areas is declining from human activities. Losses of mangrove and other tidal wetland communities are mostly the result of reclamation for coastal development of estuaries, e.g. for residential use, port infrastructure or marina development, and result in river bank destabilisation, deterioration of water clarity and loss of key coastal marine habitat. Coastal seagrass meadows are characterized by small ephemeral species. They are disturbed by increased turbidity after extreme flood events, but generally recover. There is no evidence of an overall seagrass decline or expansion. High nutrient and substrate availability and low grazing pressure on nearshore reefs have lead to changed benthic communities with high macroalgal abundance. Conservation and management of GBR macrophytes and their ecosystems is hampered by scarce ecological knowledge across macrophyte community types. (c) 2004 Elsevier Ltd. All rights reserved.

Explaining point variability in the eastern Victoria river region, northern territory

This paper constructs a reduction sequence model for north Australian points from the eastern Victoria River region, and identifies a single continuum linking unifacial and bifacial point forms, with some divergence from this single reduction trajectory dependent upon artefact size. Chronological changes in reduction intensity between 5,000BP and the present are found to coincide with typological variation in points as well as changing emphasis on the extendibility of point reduction. It is suggested that changes in the extendibility of point reduction can be linked to intensified ENSO-driven climatic variability in the late Holocene that likely increased economic risk and warranted a substantial technological response, including the use of retouched toolkits with potential for longer use-lives.

Poverty and the economic effects of TB in rural China

OBJECTIVE: To investigate the economic effects of illness on individual tuberculosis (TB) cases in rural China and to use a case-control study to show a strong TB-poverty link. SETTING: In 2002-2004 we studied 160 new smear-positive pulmonary tuberculosis (PTB) cases and 320 age- and sex-matched controls living in neighbouring houses in four rural counties of Henan Province. DESIGN: Cases and controls were interviewed 1-3 months after patients were diagnosed. We used matched multivariate logistic regression to compare cases with controls for poverty status using household income, household assets and relative wealth within the village. We conducted follow-up interviews of patients 10-12 months later to assess economic effects by collecting data on treatment costs, income losses, coping strategies and treatment completion. RESULTS: Poverty is strongly associated with TB incidence even after controlling for smoking and other risk factors. Excluding income losses, direct out-of-pocket treatment costs (medical and non-medical) accounted for 55.5 % of average annual household income, and most TB cases fell into heavy debt. The DOTS cure rate was 91 %. When DOTS was incomplete or not done, mortality was high. CONCLUSIONS: Poverty is both a cause and a devastating outcome of TB. Ongoing poverty reduction schemes in China must also include reducing TB.

Urinary arsenic, porphyrins and malondialdehyde in a population 16 years after arsenic mitigation program in Xinjian, China

Arsenic contamination of groundwater (0.05 to 0.84 mg/L) in Kuitun, Xinjiang was first found in 1970’s. Alternative clean surface water was introduced in 1985. We aimed to assess the exposure and heath outcome since the mitigation. In 2000, we collected a total of 360 urine samples from villagers from the endemic area and a nearby control area for arsenic (As), porphyrins and malondialdehyde (MDA) measurements. The averaged urinary As level of villagers from the endemic site (117±8.3 μg/g creatinine; 4.2 to 943.8 μg/g creat) was higher than that of the control site (73.6±3.2 μg/g creat). No significant differences were found in urinary porphyrins or MDA between the endemic and control sites. However, when the urinary arsenic was higher than 150 μg/g creat, these two biomarkers were higher in the exposed group than the control. Within the exposed group, villagers with arsenic-related skin symptoms had higher arsenic, uroporphyrin and MDA compared to those who had not shown symptoms. Sine the water mitigation, villagers whose urinary arsenic levels were 270 μg/g creat dropped from 20% to 10% of the population. Population with arsenic-related skin symptoms remained unchanged at 31%. We noted that 7.8% of those who had skin lesions were born after the implementation of intervention and that some villagers still prefer to drink the groundwater. Further, in the dry season, lack of surface water and electrical power breakdowns are to blame for failure to ensure continuous supply of clean water. It is concluded that despite the prompt action and successful water mitigation program to curb arsenic poisonings, it is essential to continue to monitor the health outcome of this population.