An initial survey of the cattle grub Dermatobia hominis (L. Jr.) in Nicaragua

After the civil war and the Hurricane-Mitch disaster, cattlemen in Nicaragua were forced to transport their cattle from lowland areas to higher, dryer areas of the country. These areas are natural ecological niches for the cattle grub Dermatobia hominis (L. Jr.) (Diptera: Cuterebridae). To determine the importance of this infestation, the Agricultural and Livestock-Forestry Ministry selected a central area of Nicaragua to run a pioneer survey program to acquire information about hosts involved, number of cases, treatments applied and general knowledge of 42 farmers about the life cycle of the parasite. The subjects were either farm owners or farm managers. Ninety-five percentage of the farms indicated cases of D. hominis infestation in their animals, with cattle being the most affected host (100% of the affected farms). There was poor understanding of the D. hominis life cycle, vectors and control methods. A misuse of insecticides for the treatment of larval infestation by D. hominis was indicated.     

Local Industry Agglomeration and New Business Activity

New businesses are highly involved in innovative activity, which enhances worker productivity and leads to increased economic output. This paper investigates the effects of industry concentration on the incidence of new business openings in the 5,504 Maine county‐industries. Empirical findings indicate that new business activity increases with the number of incumbent establishments in a county‐industry and its concentration level relative to the U.S. economy. Model simulations show that raising county‐industries, with no initial industry presence, to concentration levels similar to that of the industry in the U.S. economy results in a 1.7 to 8.9 percent increase in the expected number of business openings over a three‐year period. Empirical results also suggest that industry clusters comprised of young and small establishments are more conducive to new business formation than clusters made up of mature and large companies.     

Enzymatic O-methylation of flavanols changes lag time, propagation rate, and total oxidation during in vitro model triacylglycerol-rich lipoprotein oxidation

3'-O-Methyl derivatives of flavan-3-ols, (+)-catechin (C), (-)-epicatechin (EC), and (-)-catechin gallate (CG) were prepared enzymatically. Hexanal (EC and CG family, 5 mmol/L) and conjugated diene (C and EC family, 0.25-10 mmol/L) formation following CuSO4-mediated triacylglycerol-rich lipoprotein oxidation was measured. All EC and CG compounds significantly reduced hexanal formation (p < 0.02). O-Methylation improved the ability of CG (more polar) while reducing the ability of EC (less polar) to limit hexanal formation. 3'-O-methyl EC was 18% (p < 0.001) and 4'-O-methyl 65% (p < 0.001) less able than EC to suppress hexanal formation. At >1 micromol/L all EC and C compounds significantly increased lag time. Parent compounds were more effective (> 4-fold increase) than metabolites (1.5-fold increase). Parent compounds did not influence propagation rate (DeltaOD/min). At >1 mmol/L O-methylated EC and C reduced propagation by 20-40% (p < 0.01). Notably, at 0.25 mmol/L O-methylated EC and C increased propagation rates 22% (p < 0.01) despite prolonging lag time.     

Signal Interactions in Induced Resistance to Pathogens and Insect Herbivores

Plants are often simultaneously challenged by pathogens and insects capable of triggering an array of responses that may be beneficial or detrimental to the plant. The efficacy of resistance mechanisms can be strongly influenced by the mix of signals generated by biotic stress as well as abiotic stress such as drought, nutrient limitation or high soil salinity. An understanding of their biochemical nature, and knowledge of the specificity and compatibility of the signaling systems that regulate the expression of inducible responses could optimize the utilization of these responses in crop protection. Signaling conflicts and synergies occur during a plant's response to pathogens and insect herbivores, and much of the research on defense signaling has focused on salicylate- and jasmonate-mediated responses. We will review our results using tomato (Lycopersicon esculentum) in greenhouse and field studies that illustrate a trade-off between salicylate- and jasmonate-mediated signaling, and discuss research on strategies to minimize the trade-off that can occur following the application of chemical elicitors of resistance. In addition, there is evidence of another signaling system that mediates endogenous levels of ceramide in the plant. This signal is associated with programmed cell death and protection of tomato against the fungal pathogen Alternaria alternata f. sp. lycopersici.     

Role of sorption and degradation in the herbicidal function of isoxaflutole

BACKGROUND: The fate of isoxaflutole (IFT) in soil is closely related to soil sorption. Sorption and transformation of IFT were investigated in laboratory incubations with four soils, and these results were used to interpret greenhouse studies using IFT to control several weed species. RESULTS: Degradation proceeded by previously observed pathways to form diketonitrile (DKN) and benzoic acid (BA) derivatives, as well as traces of unidentified products. Over the course of the incubation, DKN was the dominant active form of the herbicide present in the experimental system, and was thus critical to the soil activity of the herbicide for weed control. CONCLUSION: Control of most weed species appeared to be a function of both sorption and biodegradation of DKN, with greatest weed control being observed in soils in which a significant portion of the DKN that was formed persisted and remained bioavailable over the course of the incubation. Copyright © 2009 Society of Chemical Industry     

Occurrence and distribution of earthworms in agricultural landscapes across Europe with regard to testing for responses to plant protection products

Purpose

Within the regulatory framework for authorisation of plant protection products (PPPs) (EU Directive 91/414/1991/EEC replaced by Regulation (EC) 1107/2009), higher tier risk assessments and earthworm field tests are conducted in different countries across Europe. This paper describes dominant earthworm species for regulatory and biogeographical regions in agricultural landscapes across Europe and examines regional differences in earthworm communities and densities and their respective response to a toxic reference.

Materials and methods

For the assessment of earthworm abundance and species distribution, data of untreated control plots from 30 earthworm field studies were analysed; each conducted according to the ISO 11268–3 (1999) guideline by European Crop Protection Association member companies in the context of registration of PPPs. For the evaluation of the response to PPPs under different regional and climatic conditions, the effect on earthworm abundance was assessed by comparing plots treated with toxic references with untreated control plots. Additionally, a comparative literature review was included providing an overview of earthworm species composition and densities in agricultural crops from 14 European countries.

Results and discussion

The assessment of earthworm field studies from six different European countries revealed that common earthworm species of anecic and endogeic ecological groups are present at most field sites. Dominant species groups of endogeic and anecic earthworms can be defined that are abundant in all assessed countries. These are the endogeic species Aporrectodea caliginosa, Aporrectodea rosea and Allolobophora chlorotica, and the anecic species Lumbricus terrestris (Northern and Central Europe) and Lumbricus friendi (Southern Europe). Taking into account the high variability in total earthworm abundances, it can be concluded that the variability within regions was larger than the variability between regions.

Conclusions

Analysis of the earthworm community and data of toxic references lead to the conclusion that testing in different zones is not considered necessary.     

Sequence characterization of two new members of a multi-gene family in Serpulina hyodysenteriae (B204) with homology to a 39 kDa surface exposed protein: vspC and D.

Previous cloning and sequencing of clones from a genomic library constructed from Serpulina hyodysenteriae B204 had identified a tandem pair of open reading frames, identified as vspA and vspB (variable surface protein) expected to encode proteins with homology to ( but not identical with) a 39 kDa surface exposed membrane protein from this animal pathogen. Additional screening of the genomic library was performed to retrieve the remainder of the vspB gene using new oligonucleotide probes based upon the cloned gene sequences. Not only was this goal met but we also discovered two more adjacent and related vsp genes (vspC and vspD) and have completely sequenced them. They are all in a parallel orientation and appear to have a set of similar but distinct regulatory elements that may control separate expression of their open reading frames (ORFs). Thus, there are four contiguous vsp genes which are predicted to encode a family of structurally conserved proteins. The four adjacent open reading frames (ORFs) are of similar size (384-389 codons) and share from 83% to 90% identity in their amino acid sequence. Preliminary data suggests there may be yet another homologous gene copy in a distal location of S. hyodysenteriae that faithfully encodes the 39 kDa surface protein. The organization and homologies of these highly conserved multiple gene copies are discussed.     

Effects of the Housing Boom and Bust on U.S. Metro Employment

This paper examines the effects of the housing boom of the early 2000s on unemployment in U.S. metropolitan areas. A region's share of housing units built between 2000 and 2006 has no effect on unemployment prior to the start of the Great Recession, but the extent of a region's housing boom increases unemployment in over one‐half of the months analyzed during and immediately following it. Regression results based on a cluster analysis of metropolitan areas indicate that regions characterized by high growth rates of construction, retail, and hospitality employment during the early 2000s were hit particularly hard by the recession.