Wild dog management in Australia: An interactional approach to case studies of community-led action

Wild dogs are a widespread, established pest in Australia and have economic, environmental, and social impacts. Best practice management recommends coordinated community-led action as a key strategy to reduce this vertebrate pest. This research increased understanding of how citizens organize to collectively manage wild dogs in three case studies from Australia, with attention to the interaction of cultural, structural, and interactional domains of group action. Information asymmetry and changing demographic profiles emerge as challenges to effective group development. Visible community leaders and strong group identity are important, as is peer recognition of community efforts to develop collective action norms. This article complements and extends existing quantitative data sets with qualitative analysis and contextual understanding, while also reflecting on the implications of collective action for wild dog management more broadly. This research is relevant for those concerned with community action and complex issues of vertebrate pest management.     

Identification and heterologous expression of a Sarcoptes scabiei cDNA encoding a structural antigen with immunodiagnostic potential

The mite Sarcoptes scabiei causes sarcoptic mange (or scabies), a disease of considerable human and veterinary significance. An S. scabiei cDNA clone of about 2 kb was isolated from a S. scabiei var. hominis expression library by immunological screening using blood serum from a naturally infected chamois (Rupicapra rupicapra). The nucleotide sequence of the identified cDNA contains an open reading frame of 1930 bp that encodes a 642 amino acid polypeptide. This polypeptide shows tandem repeats of a glycine-serine rich 20 residue sequence followed by a unique C-terminal glutamate rich 54 residue sequence. The cDNA or the deduced polypeptide did not show significant similarities to any of the sequences in the databases. A carboxyl-terminal fragment of this polypeptide (residues 380 to 642) was efficiently expressed in Escherichia coli as a fusion with Glutathione S-transferase and then was used to produce a specific antiserum. The antigen encoded by the cDNA was located at the integument of the mite's epidermis and the cavities surrounding its vital organs. Western blot analysis of mite extracts using the specific antiserum against the recombinant protein identified antigens larger that 60 kDa indicating that the isolated cDNA did not contain the full ORF. Moreover, we designed a diagnostic assay based on the carboxyl-terminal fragment of the antigen for the identification of infected animals.     

Piscine orthoreovirus (PRV) infects Atlantic salmon erythrocytes

Piscine orthoreovirus (PRV) belongs to the Reoviridae family and is the only known fish virus related to the Orthoreovirus genus. The virus is the causative agent of heart and skeletal muscle inflammation (HSMI), an emerging disease in farmed Atlantic salmon (Salmo salar L.). PRV is ubiquitous in farmed Atlantic salmon and high loads of PRV in the heart are consistent findings in HSMI. The mechanism by which PRV infection causes disease remains largely unknown. In this study we investigated the presence of PRV in blood and erythrocytes using an experimental cohabitation challenge model. We found that in the early phases of infection, the PRV loads in blood were significantly higher than in any other organ. Most virus was found in the erythrocyte fraction, and in individual fish more than 50% of erythrocytes were PRV-positive, as determined by flow cytometry. PRV was condensed into large cytoplasmic inclusions resembling viral factories, as demonstrated by immunofluorescence and confocal microscopy. By electron microscopy we showed that these inclusions contained reovirus-like particles. The PRV particles and inclusions also had a striking resemblance to previously reported viral inclusions described as Erythrocytic inclusion body syndrome (EIBS). We conclude that the erythrocyte is a major target cell for PRV infection. These findings provide new information about HSMI pathogenesis, and show that PRV is an important factor of viral erythrocytic inclusions.     

Evaluation of a Multi-species Test System for Assessing Acute and Chronic Toxicity of Sediments and Water to Aquatic Invertebrates: Effects of Pentachlorophenol on Daphnia magna and Chironomus prasinus (6 pp)

Background, Aims and Scope   Single-species toxicity tests are currently used as main tools for assessing effects in ecological risk assessments. Nevertheless, in higher-tier evaluations, alternative ecotoxicological methods can be required. Alternative methods should cover more realistic exposure conditions and/or additional species or endpoints. Water/sediment systems can be considered for covering additional exposure routes. A typical feature of water/sediment systems is the modification of exposure levels with time. The simultaneous exposure of different species within the same system can cover differences in sensitivity and relevance of exposure routes. The aim of this study was to develop a water/sediment test that could detect relevant effects on two selected species and explore the relevance of sediment and waterborne exposure routes. This alternative method may provide relevant information facilitating the design of microcosm and mesocosm studies.Methods   A multi-species water/sediment system was designed using two invertebrates: Chironomus prasinus a benthic detritivore invertebrate and Daphnia magna a pelagic filtering invertebrate was designed. Seven static water/sediments systems were built up: two controls and five treatments where sediments were spiked with NaPCP at nominal concentrations of 1.25, 2.5, 5, 10 and 20 mg/kg, respectively. Each system contained caged and free (unrestrained) Daphnia magna organisms to consider differences in the exposure route (through sediment and/or water column) and Chironomus prasinus organisms. Fate and partitioning of PCP within the water/sediment compartments were assessed. Acute (lethality) and chronic effects (reproduction) for Daphnia magna were monitored after 48 h and 16 days of exposure, respectively. Adult emergence and oviposition success of Chironomus prasinus were monitored at the end of test (16 days).Results and Discussion   Mortality and reproduction inhibition of Daphnia magna occurred at the two higher doses, corresponding to maximum measured PCP water concentrations of 1.95 and 0.746 mg/l, respectively. Chironomus prasinus was less sensitive to PCP than Daphnia magna. Concentrations inhibiting reproduction and provoking almost 100% adult mortality in D. magna only reduced slightly the emergence and reproduction of chironomids. The experimental design focussed on suitability of the system for assessing simultaneously assessing effects on D. magna and C. prasinus instead of calculations of toxicity endpoints for PCP. The results indicate that this experimental design can be useful to the field of sediment/aquatic toxicity testing, particularly through the comparison with single- species results. Assessment of relative contribution of two exposure routes for Daphnia magna and complementary chronic endpoints derived from two different species can be achieved. Another advantage is that differences in reproduction strategies of selected species (sexual vs. parthenogenetic) should permit one to detect mechanisms of action associated to with endocrine disrupters.Conclusion   The feasibility of a two-species test built-up in an artificial sediment/water system has been demonstrated. This experimental design represents a cost/effective test which can assess effects through water and sediment pathways and incorporates several relevant chronic endpoints in a single assay. Recommendation and Outlook   By building on the experience gained, improvements for further test designs are discussed. Test validation with a set of model chemicals will contribute to address the effectiveness of the test developed as comparing compared to single- species tests.     

Development of an innovative conceptual model and a tiered testing strategy for the ecological risk assessment of rice pesticides

Rice paddies constitute a very special agrobiosystem, which for some circumstances, could be considered as a human driven wetland. The complexity of such dynamic systems is a key element for conducting ecological risk assessments, in addition, the proximity of rice paddies to areas of high ecological value must be considered. This paper presents a new conceptual model for conducting ecological risk assessments of pesticides and other agrochemicals in rice, based on a combination of three main elements, the source of the stressor, the exposed environmental compartments and the relevance of the ecological receptors. A tiered testing strategy, starting with the standard requirements for pesticides and moving to specific higher tier studies with three levels of risk refinement is also presented.     

Structure and fertilizer properties of byproducts formed in the synthesis of EDDHA

The synthesis of commercial EDDHA produces o,o-EDDHA as the main reaction product, together with a mixture of regioisomers (o,p-EDDHA and p,p-EDDHA) and other unknown byproducts also able to complex Fe3+. These compounds have been obtained by direct synthesis, and their structures have been determined by ESI-MS analysis as oligomeric EDDHA-like products, formed by polysubstitution in the phenolic rings. Short-term experiments show that the iron complexes of samples enriched in these oligomeric byproducts have adequate stability in solution, but a significant amount of them is lost after interaction with soils and soil materials. Mildly chlorotic cucumber plants are able to reduce iron better from o,p-EDDHA/Fe3+ than from the iron complexes of the oligomeric byproducts. In hydroponics, the chlorotic soybean susceptible plants have a lower potential for Fe absorption from these byproducts than from o,o-EDDHA/Fe3+ and from o,p-EDDHA/Fe3+. In the studied conditions, the iron chelates of EDDHA byproducts do not have the long-lasting effect shown by o,o-EDDHA/Fe3+ and present a less efficient fast-action effect than the o,p-EDDHA/Fe3+.     

Differential expression of ISG 15 mRNA in peripheral blood mononuclear cells of nulliparous and multiparous pregnant versus non‐pregnant Bos indicus cattle

Embryonic mortality is found to be the main source of reproductive wastage in domestic ruminants. Many genes are involved in the growth and development of the embryo, and the interferon‐stimulated gene 15 (ISG 15) is one of the major gene stimulated by interferon tau, the maternal recognition of pregnancy signal in ruminants. In this study, both genomic and cDNA sequences of ISG 15 from Bos indicus (Deoni breed) were amplified and characterized. The genomic sequence of Deoni ISG 15 exhibited 99% identity with Bos taurus and 97% identity with that of Bos mutus and Bubalus bubalis. Moreover qRT‐PCR analysis revealed constitutive expression of the ISG 15 mRNA in peripheral blood mononuclear cells of Deoni heifers and multiparous cows during early pregnancy. Fourteen Deoni heifers and fifteen multiparous Deoni cows were synchronized for timed AI by CIDR‐Ovsynch protocol, and six animals were kept as cyclic control in each group. Blood samples were collected on days 7, 14, 16, 18, 21, 30 and 45 from the day of AI. Pregnancy was confirmed by plasma progesterone level through ELISA. A significantly higher expression of ISG 15 mRNA was found on day 16 (p < .05) and day 18 (p < .05) of pregnancy in nulliparous heifers. Although in multiparous Deoni cows ISG 15 expression was greater in pregnant cows, difference was statistically non‐significant. The result of this study indicates that ISG 15 gene expression is upregulated during 16–18 days of pregnancy and could be used as an early pregnancy marker in dairy cows especially in heifers.     

Sorption and thermodynamic properties of wood of <Emphasis Type="Italic">Pinus canariensis</Emphasis> C. Sm. ex DC. buried in volcanic ash during eruption

The hygroscopicity and thermodynamic properties of Pinus canariensis wood buried in volcanic ash, dating from 1100 BC, were studied and compared with recently felled juvenile and mature wood of the same species. The sorption isotherms were obtained by the saturated salt method at 35 and 50 °C. The isotherms were fitted using the Guggenheim–Anderson–de Boer model. The thermodynamic parameters were determined following the Clausius–Clapeyron integration method. To understand the behaviour of each type of wood, the chemical composition, infrared spectra and X-ray diffractograms were determined for each sample. The mature wood has a higher sugar content and lower extractive content than the juvenile and the buried wood. For both temperatures, the isotherm of the mature wood is above the isotherm of the juvenile wood and this, in turn, is above the isotherm of the buried wood, primarily influenced by the higher cellulose and hemicellulose contents and lower extractives content in the mature wood, resulting in a higher number of accessible –OH groups. Degradation of the buried wood due to high temperatures explains why its isotherms are below the isotherms of the recent wood. The energy involved in the desorption process is greater than in adsorption. Similarly, more energy is involved in the mature wood than in the juvenile wood, and the energy involved in the juvenile wood is greater than in the buried wood.