A survey for paramyxoviruses in caged birds, wild birds, and poultry in New Zealand

AIMS: To determine the presence of avian paramyxovirus (APMV) types 1, 2, and 3 in caged and wild birds, and APMV-2 and -3 in poultry in New Zealand. METHODS: Blood samples collected from caged (231) and wild birds (522) from various regions of New Zealand in 1997-99 were tested by haemagglutination inhibition (HI) test for antibodies to APMV types 1, 2, and 3. Blood samples collected from 1778 commercial poultry in 1996-99 were tested for APMV-2 and APMV-3 antibodies and the samples that reacted with APMV-3 antigen were tested for antibodies to APMV-1. Isolation of APMV was attempted from cloacal swabs collected from 116 of the caged birds and 175 of the wild birds sampled. RESULTS: Antibodies to APMV types 1, 2, and 3 were detected in 4.8, 1.7, and 2.6%, respectively, of caged bird samples. The majority of these caged birds were 'exotic' or 'fancy' poultry breeds. Amongst wild birds, 4.2% had titres to APMV-2 and over half of these were passerine birds; 1.7% of the samples had titres to APMV-1 and 0.8% to APMV-3 antigen. No virus was isolated from any of the cloacal swabs tested. Of the 1778 poultry serum samples tested, only 5 reacted with APMV-3 antigen and these were later found to be cross-reactions to APMV-1. No reactions were detected with APMV-2 antigen. CONCLUSIONS: APMV-1 is present in caged birds, wild birds, and poultry of New Zealand. There is no conclusive evidence of the presence of APMV-2 and APMV-3 in poultry or APMV-3 in wild birds. The results do not provide conclusive evidence for the presence of APMV-2 in wild birds in New Zealand.     

Belowground nematode herbivores are resistant to elevated atmospheric CO2 concentrations in grassland ecosystems

Grasslands are considered to be one of the most sensitive ecosystems to rising atmospheric CO₂ concentrations, since, in addition to direct effects of elevated CO₂ on plant growth, indirect increases in water availability as an effect of elevated CO₂ may enhance primary production and alter plant community composition in these typically dry ecosystems. Moreover, grasslands support large populations of belowground herbivores that consume a major portion of plant biomass. The direct trophic link between herbivores and plants suggests that primary consumers may be particularly sensitive to rising CO₂ concentrations; however, the responses of belowground grassland herbivores have rarely been investigated. Here, we report the response of a range of herbivorous nematode populations to elevated CO₂ concentrations from three distinct grassland experiments. The three studies each involved 5–6 years of CO₂ fumigation, utilized natural or representative plant and soil communities, and were sampled at the end of the growing season. In the vast majority of cases, elevated CO₂ did not affect the abundance of nematode families; only two nematode families were significantly influenced by CO₂ enrichment (Anguinidae increased in one case and Hoplolaimidae decreased in another). Similarly, elevated CO₂ did not influence the total abundance, family richness, diversity or plant parasitic index of the herbivorous nematode community. These neutral responses to CO₂ enrichment occurred despite increased root production in all three experiments, suggesting a simultaneous antagonistic mechanism may have operated, possibly decreased root quality and/or changes in the soil environment. Whatever the mechanism, our findings suggest that herbivorous nematodes in grassland ecosystems are resistant to rising atmospheric CO₂ concentrations.     

Transient elevation of carbon dioxide modifies the microbial community composition in a semi-arid grassland

Using open-top chambers (OTC) on the shortgrass steppe in northern Colorado, changes of microbial community composition were followed over the latter 3 years of a 5-year study of elevated atmospheric CO₂ as well as during 12 months after CO₂ amendment ended. The experiment was composed of nine experimental plots: three chambered plots maintained at ambient CO₂ levels of 360±20 μmol mol^?1 (ambient treatment), three chambered plots maintained at 720±20 μmol mol^?1 CO₂ (elevated treatment) and three unchambered plots. The abundance of fungal phospholipid fatty acids (PLFAs) shifted in the shortgrass steppe under the influence of elevation of CO₂ over the period of 3 years. Whereas the content of the fungal signature molecule (18:2ω6) was similar in soils of the ambient and elevated treatments in the third year of the experiment, CO₂ treatment increased the content of 18:2ω6 by around 60% during the two subsequent years. The shift of microbial community composition towards a more fungal dominated community was likely due to slowly changing substrate quality; plant community forage quality declined under elevated CO₂ because of a decline of N in all tested species as well as shift in species composition towards greater abundance of the low forage quality species (Stipa comata). In the year after which CO₂ enrichment had ceased, abundances of fungal and bacterial PLFAs in the post-CO₂ treatment plots shifted slowly back towards the control plots. Therefore, quantity and quality of available substrates had not changed sufficiently to shift the microbial community permanently to a fungal dominated community. We conclude from PLFA composition of soil microorganisms during the CO₂ elevation experiment and during the subsequent year after cessation of CO₂ treatment that a shift towards a fungal dominated system under higher CO₂ concentrations may slow down C cycling in soils and therefore enhance C sequestration in the shortgrass steppe in future CO₂-enriched atmospheres.     

Cancer regression in patients after transfer of genetically engineered lymphocytes

Through the adoptive transfer of lymphocytes after host immunodepletion, it is possible to mediate objective cancer regression in human patients with metastatic melanoma. However, the generation of tumor-specific T cells in this mode of immunotherapy is often limiting. Here we report the ability to specifically confer tumor recognition by autologous lymphocytes from peripheral blood by using a retrovirus that encodes a T cell receptor. Adoptive transfer of these transduced cells in 15 patients resulted in durable engraftment at levels exceeding 10% of peripheral blood lymphocytes for at least 2 months after the infusion. We observed high sustained levels of circulating, engineered cells at 1 year after infusion in two patients who both demonstrated objective regression of metastatic melanoma lesions. This study suggests the therapeutic potential of genetically engineered cells for the biologic therapy of cancer.     

First detection of Edwardsiella ictaluri (Proteobacteria: Enterobacteriaceae) in wild Australian catfish

The bacterium Edwardsiella ictaluri is considered to be one of the most significant pathogens of farmed catfish in the United States of America and has also caused mortalities in farmed and wild fishes in many other parts of the world. E. ictaluri is not believed to be present in wild fish populations in Australia, although it has previously been detected in imported ornamental fishes held in quarantine facilities. In an attempt to confirm freedom from the bacterium in Australian native fishes, we undertook a risk‐based survey of wild catfishes from 15 sites across northern Australia. E. ictaluri was detected by selective culturing, followed by DNA testing, in Wet Tropics tandan (Tandanus tropicanus) from the Tully River, at a prevalence of 0.40 (95% CI 0.21–0.61). The bacterium was not found in fishes sampled from any of the other 14 sites. This is the first report of E. ictaluri in wild fishes in Australia.     

Ammonium and nitrate transport during saturated and unsaturated water flow through sandy soils

Citrus production in Florida accounts for ≈ 60% of national production in USA. The sandy soil characteristic (> 95% sand) makes water and nutrient management extremely difficult, raising concerns about environmental sustainability as a result of nutrient inputs in citrus producing regions where sandy soils dominate. Thus, laboratory column and field experiments were conducted to better understand the leaching patterns of and ions in Florida's sandy soils. The soil columns were first saturated from the bottom with two pore volumes of simulated Florida rain followed by pumping a pulse of fertilizer mixture at a steady Darcy flux of 14 cm h^?1. Nitrate and Cl^? appeared earlier in the effluent than in the A and B_h horizons, due to cation exchange of . Essentially identical breakthrough curves (BTCs) for and were observed in the E‐horizon, due to very low sorption of . The convective and dispersive equilibrium (CDE) model simulations were in good agreement with measured breakthrough curves (BTCs) for , , and Cl^?. However, the sorption coefficient (K_D) values used in the CDE model to simulate the BTCs for were about 10 times less than the batch isotherm K_D values. This was attributed to differences in pH, cation composition, and ionic strength between batch (static) and dynamic (leaching) systems. The field experiment showed that under unsaturated flow, improved short‐pulse fertigation systems (drip and microsprinkler) limited and transport beyond the root zone (top 30 cm), which might have promoted nutrient and water uptake in citrus. The column study revealed that under extreme weather events such as hurricanes or storm surge in Florida, saturated soil conditions can trigger N mobility below the root zone to surficial or groundwater aquifers. In the field experiment, the use of judicious, minimal and split applications and accurate placement of N‐fertilizers reduced leaching of N especially during heavy storms in the summer rainy months of Florida. The field experiment demonstrated that it is possible to manage inorganic N forms for optimal residence time for uptake and minimal leaching concerns.     

Clinical peripheral neuropathy associated with diabetes mellitus in 3 dogs

Clinical and electrodiagnostic findings in 3 spontaneously diabetic dogs with clinical peripheral neuropathy (PN) are reported. Clinical signs of a PN may develop in diabetic dogs with adequate glycemic control. In addition, laryngeal paralysis may develop in association with diabetes mellitus in dogs with clinical PN.     

Too little but not too late? Biology of a recently discovered and imperilled freshwater fish in a drying temperate region and comparison with sympatric fishes

• 1. Small‐bodied freshwater fishes are commonly overlooked in threatened species management despite being highly imperilled. Before this study, the newly described little pygmy perch (Nannoperca pygmaea) was known from only 0.06 km² of habitat in a single catchment in south‐western Australia and a lack of knowledge prevented an understanding of its conservation status and priority actions.
• 2. The present study determined the distribution, biology, and movement patterns of N. pygmaea and compared these with other small, sympatric percihthyids to assess its conservation status and likely resilience to threatening processes.
• 3. The current ‘extent of occurrence' of N. pygmaea was determined to be 3,420 km² and the ‘area of occupancy' was 10 km². Nannoperca pygmaea inhabited permanent refuge pools in the main stem of an ephemeral, secondarily salinized catchment where salinities remained <6 ppt during summer.
• 4. During winter N. pygmaea undertook a short upstream migration into a seasonally flowing freshwater tributary to serially spawn. The timing of reproduction was partitioned among three sympatric pygmy perches within the austral winter/spring period.
• 5. The species qualifies as ‘Endangered' under the IUCN Red List assessment criteria. Its restriction to freshwater refugia within salinized rivers suggests that N. pygmaea may have a limited salinity tolerance similar to the sympatric, threatened Nannatherina balstoni, and that the species is susceptible to prolonged drought, drying of critical baseflow refuges, increasing salinization, and introductions of alien species.
• 6. The study serves as an example that small‐bodied freshwater fishes need greater research attention to understand the biological and environmental mechanisms underpinning their decline.