Sulfate Reduction in Soil: Effects of Redox Potential and pH

Reduction of sulfate to sulfide in waterlogged soils was dependent on soil redox potential and pH. Little or no sulfide accumulated with a redox potential above -150 millivolts, or with a pH outside the range 6.5 to 8.5.     

A review of laboratory techniques and their use in the diagnosis of Leptospira interrogans serovar hardjo infection in cattle

SUMMARY This paper reviews the laboratory diagnosis of Leptospira hardjo infection in cattle. Two genotypes of L hardjo, Hardjoprajitno and Hardjobovis, have been identified in cattle, but only Hardjobovis has been isolated in Australia. There are problems with diagnosis and control of bovine leptospirosis. Infection is usually subclinical and the serological titres vary greatly in peak and duration. Leptospires may be excreted in urine for up to 18 months. Low microscopic agglutination test titres may be significant in unvaccinated herds as indicators of endemic infection. Vaccines differ in their composition, and their efficacy is difficult to evaluate. The serological response after vaccination is difficult to differentiate from the response after infection. Pregnant cows that become infected may abort, but this is usually after the serological response has peaked. Therefore, paired serum samples are of little use in diagnosing abortion caused by L hardjo. Fluorescent antibody techniques are more sensitive than dark field microscopy for detection of leptospires in urine and tissue samples. Techniques for culture have improved but are still difficult to perform and take 3 months or longer for results to be known. DNA probes and polymerase chain reaction tests are very sensitive and specific, quick to perform, and can be used on fluid and tissue samples.     

Losing ground? Tuvalu,the greenhouse effect and the garbage can

Abstract: Greenhouse‐induced sea‐level rise (SLR) threatens coral atolls and particularly the few atoll states, such as Tuvalu. This central Pacific island microstate has minimal economic development options, and has increasingly perceived emigration and remittances as a development strategy, despite restricted opportunities. Internal migration, in search of wage employment, has brought almost half the national population to Funafuti atoll, with negative local environmental consequences. Short‐term scientific data show no evidence of SLR in Tuvalu, but the Government of Tuvalu has argued that there is visual evidence of SLR, through such consequences as increased erosion, flooding and salinity. Global media have increasingly emphasised a doomsday scenario, with Tuvalu as synecdoche and symbol of all threatened island environments. Environmental problems of diverse origin have been entirely attributed to distant processes causing SLR, in terms of ‘garbage can anarchy’ or a ‘conspiracy narrative’, and thus to distant causes. The Tuvalu Government has consequently sought compensation from, and migration opportunities in, distant states. The construction of apparently imminent hazard has potential domestic political and economic advantages, but environmental costs.     

Pulmonary mycobacteriosis caused by Mycobacterium intracellulare in a Tasmanian devil (Sarcophilus harrisii)

The health of captive Tasmanian devils (Sarcophilus harrisii) is currently of increased interest because wild populations are being decimated by the spread of devil facial tumour disease. This report describes the pathology of an aged captive Tasmanian devil that had a pulmonary mycobacterial infection caused by Mycobacterium intracellulare in addition to multiple neoplastic processes.     

Lung worm (Marsupostrongylus spp.) infection in common brushtail possums (Trichosurus vulpecula)

Marsupostrongylus spp. are the metastrongyloid nematodes most commonly associated with verminous pneumonia in Australian marsupials. Currently, there is a scarcity of information regarding this parasite in the common brushtail possum (Trichosurus vulpecula). Thirty-four free-living possums submitted to two wildlife hospitals in Sydney, Australia, between 2008 and 2015 were diagnosed with verminous pneumonia on postmortem examination. The majority of possums presented ill with multiple comorbidities. However, only five cases had clinical signs of respiratory disease. Necropsy and histopathology revealed extensive lung lesions characterised by diffuse, mixed interstitial infiltrates of macrophages, lymphocytes and plasma cells with mild to marked concentrations of eosinophils. Bronchopneumonia, pulmonary oedema, interstitial fibrosis, atelectasis and type II pneumocyte hyperplasia were also present in most cases. Adult nematodes, first-stage larvae and embryonating eggs were present in the large airways and alveolar spaces. The parasites were definitively identified as Marsupostrongylus spp. in eight cases with presumptive diagnoses based on histopathological characteristics reached in a further 26 cases. Twenty-nine of the 34 affected possums were adults with no sex predisposition. A review of the brushtail possum records at Taronga Wildlife Hospital from 1999 to 2015 revealed no lungworm infections were reported in the 45 possums examined before 2008. However, between 2008 and 2015, 30 of 47 possums (63.8%) examined were diagnosed with metastrongyloid lungworms. This case series is the first detailed report of Marsupostrongylus nematodes in common brushtail possums and highlights the clinical and pathological features, along with epidemiological findings.     

Strategies for scaling out impacts from agricultural systems change: the case of forages and livestock production in Laos

Scaling out and up are terms increasingly being used to describe a desired expansion of beneficial impacts from agricultural research and rural development. This paper explores strategies for scaling out production and livelihood impacts from proven technologies. We draw on a case study of forages and livestock production in Laos, a Southeast Asian country undergoing rapid economic and agricultural change. A facilitated learning environment stimulated farmers to adapt forages, livestock housing, and animal health practices to their own situations (scaling out). Regular follow-up visits and on-the-job mentoring for extension staff provided institutional support (scaling up). Within 5 years, the number of villages and households using forages and fattening livestock had increased six fold, with a 50% reduction in the time required for farmers to get significant benefits. The paper concludes that scaling out positive impacts from systems change requires field tested and proven technologies, evidence of significant livelihood impacts, fostering of local innovation, competent field staff, effective peer learning, and ongoing institutional support.     

A collaborative study of residues on wheat of chlorpyrifos-methyl,fenitrothion, malathion,methacrifos and pirimiphos-methyl. 1. Method development

The accuracy and reproducibility of analytical methods for the assay of five organophosphorus grain protectants have been investigated by a coordinated test programme. Results were assessed using data from field applications of chlorpyrifos-methyl, fenitrothion, malathion, methacrifos and pirimofos-methyl at commercial silos in New South Wales and Queensland. A satisfactory analytical procedure is recommended following an extended series of tests.