Physiological host range of Trissolcus mitsukurii,a candidate biological control agent of Halyomorpha halys in Europe

Journal of Pest Science - The invasive stink bug Halyomorpha halys, native to East Asia, is a severe agricultural pest of worldwide importance, and chemical insecticides are largely sprayed for its...     

Antibacterial efficacy of polypyrrole in textile applications

This paper describes application and evaluation of polypyrrole as an antibacterial polymer. Polypyrrole was produced embedding two doping agents: chloride and dicyclohexyl sulfosuccinate ions. Stability of the antibacterial efficacy of polypyrrole deposited on cotton fabrics was assessed before and after three different kinds of washing (namely, laundering with anionic and non-ionic detergents and dry-cleaning). Polypyrrole showed excellent antibacterial properties (100 % of bacterial reduction) against Escherichia coli for both doping agents. Treated fabrics were further characterised by scanning electron microscopy, energy dispersive X-ray analysis and infrared spectroscopy. The antibacterial efficacy diminished after launderings with anionic and non-ionic detergents because of two different mechanisms: the neutralisation of positive charges under alkali conditions (dedoping), and a partial removal of polypyrrole by abrasion and surfactant action. After dry-cleaning, polypyrrole embedding chloride and dicyclohexyl sulfosuccinate ions still showed excellent antibacterial efficacy. Moreover, scanning electron microscopy investigations were used to intuitively explain the bactericidal mechanism of polypyrrole on Escherichia coli bacteria.     

Assembling local,assembling food security

The term ‘food security’ has been used in multiple ways and addresses not only issues around availability and accessibility of foods, but also, among others, the sustainability of livelihoods at the local community level—an issue often seen as a basis for the proliferation of local and alternative food networks (AFNs). Accordingly, in this paper we attempt to develop a theoretical re-framing that is able to link food security with AFNs in arguing that the understanding of the two notions is dynamics and contingent upon the elements (actors, practices, geography) that construct them. We use an assemblage approach to analyze a case of Dunedin, a small-size city in New Zealand, in which the community aims to achieve food security through a local food strategy. Through a series of interviews with a group of food activists and academics, public discussions, and two local food forums, we found that food security was understood and performed in its local context through assembling diverse actors and objectives within the AFN. In conclusion, we offer assemblage thinking as an analytical tool to understand how seemingly precarious local food relations are stabilized and assembled so as to open possibilities of achieving food security.     

Accumulation and distribution of copper and zinc in soils following the application of pig slurry for three to thirty years in a microwatershed of southern Brazil

The application of pig slurry to soil can result in the accumulation of soil Cu and Zn, alter soil Cu and Zn fractions, and result in soil, surface water, and subsurface water contamination. This study evaluated the accumulation and distribution of Cu and Zn in soil profiles from 10 areas treated with pig slurry for 3–30 yr. A microwatershed within the municipality of Braço do Norte in the state of Santa Catarina and in the southern region of Brazil was studied. Hapludalf soil samples were collected at depths of 0.0–0.05, 0.05–0.10, 0.10–0.20, 0.20–0.30, and 0.30–0.40 m from 10 areas where pig slurry had been applied for 3–30 yr. The soil samples were dried, prepared, and analyzed to determine their chemical characteristics, particularly to quantify their Cu and Zn fractions. Although long-term pig slurry application resulted in greater available Cu and Zn concentrations in the surface soil layer, the migration of available Cu in the soil profile only occurred in areas that were subjected to more than 17 yr of slurry application. The application of pig slurry increased the available Cu and Zn contents in the surface soil layer; however, the available Cu in the soil profile increased in the areas with more than 17 yr of slurry application. Cu accumulation mainly occurred in the organic and mineral soil fractions, and Zn accumulation mainly occurred in the mineral fraction. Overall, Cu posed a greater risk for surface water contamination than Zn, especially in areas with more than 17 yr of pig slurry application.     

PCV2-DNA in formalin-fixed and paraffin embedded lymph nodes of wild boar (Sus scrofa ssp. scrofa): one sampling approach for two laboratory techniques

Superficial inguinal lymph nodes from 72 wild boars examined in a previous immunohistochemical (IHC) study on porcine circovirus type 2 (PCV2) were selected for a PCV2 polymerase chain reaction (PCR) analysis. Four of these lymph nodes were PCV2-IHC strongly positive with PMWS histological lesions (outcome 1), 6 weak to mild PCV2-IHC positive without PMWS histological lesions (outcome 2) and 62 PCV2-IHC negative. Considering IHC the gold standard for diagnosis, the aims of the study were to evaluate the suitability of the PCV2-DNA extraction from formalin-fixed and paraffin-embedded (FFPE) tissue and the sensitivity and specificity of PCR under two IHC interpretations criteria: (A) the sample was considered positive if the result was outcome 1; (B) the sample was considered positive if the result was outcome 1 or 2. Under (A) criteria, sensitivity and specificity of PCR were 100% and 89.7%, respectively; the Cohen''s Kappa coefficient was 0.49. Under (B) criteria, sensitivity and specificity of PCR were 80.0% and 95.2%, respectively; the Cohen''s Kappa coefficient was 0.72. The high Cohen''s Kappa coefficient under the (B) interpretative criteria indicates good agreement between the two methods. In conclusion, 1) DNA extracted from FFPE specimens of wild boar is suitable for PCR and further represents a screening test for PCV2/PCVD (PCV2 Diseases) investigations in wild boar as well; 2) routine histological sampling can also be useful for PCV2 virological studies in wild boar.     

Composition and biological activity of essential oil of Achillea ligustica All. (Asteraceae) naturalized in central Italy: Ideal candidate for anti-cariogenic formulations

Essential oil from flowers (FL) and vegetative parts (VP) of Achillea ligustica (Asteraceae), naturalized after cultivation in central Italy, was investigated by GC–FID and GC–MS. The most abundant components were linalool, viridiflorol, β-pinene, 1,8-cineole and terpinen-4-ol. The antioxidant assays (DPPH and ABTS radical scavenging assays, and β-carotene bleaching test) demonstrated a moderate activity of essential oils. The antimicrobial activity was evaluated by the broth micro-dilution method on 6 microbial strains and showed to be quite strong against the cariogenic Gram-positive Streptococcus mutans, suggesting that this essential oil could be a valid candidate for anti-cariogenic formulations. Moderate cytotoxic activity was observed in assays on four tumour cell lines by MTT assay.     

Copper Accumulation and Availability in Sandy,Acid, Vineyard Soils

The use of copper (Cu)-based fungicides to control diseases in vineyards can cause excessive Cu accumulation in soils. Greater Cu availability is expected in acid sandy soils with low organic matter (OM), where the risk of toxicity to plants and environment contamination is high. This study aimed to study the evolution of Cu in acid, sandy soils planted with grapevines for a period of time between 2 and 32 years. Two studies were carried out in South Brazil: in the first study, soil samples, from 19 vineyards were collected and analyzed in the first 0.2 m depth-layer for the total and available Cu. In the second study, 3 soils were selected among the previous 19 according to the age of vineyard (5, 11, and 30 year-old), and their 0.60 m-depth profile was analyzed for 5 fractions of Cu (soluble, exchangeable, mineral, organic, and residual). All the soils were classified as Ultisols. The vineyards with more than 25 years under cultivation had a mean total Cu concentration of 90 mg kg^?1 in the 0–0.10 m layer. Approximately 80% of it was potentially available to plants. The greatest total and available Cu were found in the soil surface layers (0.2 m depth), where up to 75% of the total Cu is adsorbed in clay minerals and only 20% is complexed in the OM.