Characterizing spatial distribution of trap captures of beetles in retail pet stores using SADIE software

The weevils, Sitophilus spp., drug store beetle, Stegobium paniceum (L.), and red flour beetle, Tribolium castaneum (Herbst) in two retail pet stores in Kansas, USA, were sampled with pitfall traps on five separate occasions before and four separate occasions after a thorough sanitation in areas with high trap captures. Trap captures of Sitophilus spp. and S. paniceum in store 1 and those of T. castaneum and Sitophilus spp. in store 2, were analyzed using the Spatial Analysis of Distance IndicEs (SADIE^®) software. Captures of Sitophilus spp. in store 1 and T. castaneum in store 2 increased immediately after sanitation, but subsequently were similar to levels before sanitation, whereas captures of S. paniceum in store 1 and Sitophilus spp. in store 2 were unaffected by sanitation. In store 1, S. paniceum trap captures were randomly distributed on all sampling occasions, while Sitophilus spp. captures were spatially aggregated immediately before and after sanitation. During the 6 months of trapping, the Sitophilus spp. trap capture centroids gradually moved northwards, and those of S. paniceum moved southwards. In store 2, trap captures of T. castaneum and Sitophilus spp. were uniformly distributed before sanitation and were predominantly spatially aggregated after sanitation. During the 6 months of trapping, trap capture centroids of both T. castaneum and Sitophilus spp. gradually moved northwards. The impact of a thorough sanitation performed once on the spatial distribution patterns of insects in the two retail stores was not consistent. Sanitation was also ineffective in reducing captures of the insect species.     

Structural changes of casein micelles in a rennin gradient film with simultaneous consideration of the film morphology

The effect of rennin on the micelle structure and microstructure of casein films was investigated with micro-beam grazing incidence small angle X-ray scattering and optical microscopy. Size distributions of casein micelles and colloidal calcium phosphate particles were determined as a function of rennin concentration within a rennin gradient film. While the size of the casein micelles decreased with increasing rennin concentration, the size of the colloidal calcium phosphate clusters remained constant. In accordance with a first-order enzyme reaction mechanism, the rennin-induced decay of the micellar sizes could be well described by an exponential function. Two distinct film morphologies at high and low rennin concentration were observed. At intermediate rennin concentration a two-phase surface structure was found, in which both film morphologies coexisted. The conclusions drawn on the behaviour of casein micelles in films can generally be applied to the rennin-induced changes in casein micelles in bulk solutions.     

Temporal trends, congener patterns, and sources of octa-, nona-, and decabromodiphenyl ethers (PBDE) and hexabromocyclododecanes (HBCD) in Swiss lake sediments

With the recent ban of pentabromodiphenyl ether (technical PentaBDE) and octabromodiphenyl ether (technical OctaBDE) mixtures in the European Union (EU) and in parts of the United States, decabromodiphenyl ether (technical DecaBDE) remains as the only polybrominated diphenyl ether (PBDE) based flame retardant available, today. The EU risk assessment report for DecaBDE identified a high level of uncertainty associated with the suitability of the current risk assessment approach for secondary poisoning by debromination of DecaBDE to toxic lower brominated diphenylethers. Addressing this still open question, we investigated concentrations and temporal trends of DecaBDE, NonaBDE, and OctaBDE congeners in the sediments of Greifensee, a small lake located in an urban area close to Zürich, Switzerland. PBDE appeared first in sediment layers corresponding to the mid 1970s. While total Tri-HeptaBDE (BDE-28, -47, -99, -100, -153, -154 and -183) concentrations leveled off in the mid 1990s to about 1.6 ng/g dw (dry weight), DecaBDE levels increased steadily to 7.4 ng/g dw in 2001 with a doubling time of 9 years. Hexabromocyclododecanes (HBCD) appeared in Greifensee sediments in the mid 1980s. They are an important class of flame retardants that are being used in increasing amounts, today. As was observed for DecaBDE, HBCD concentrations were continuously increasing to reach 2.5 ng/g dw in 2001. Next to DecaBDE, all 3 NonaBDE congeners (BDE-208, BDE-207, and BDE-206) and at least 7 out of the 12 possible OctaBDE congeners (BDE-202, BDE-201, BDE-197/204, BDE-198/203, BDE-196/200, BDE-205, and BDE-194) were detected in the sediments of Greifensee. Highest concentrations were found in the surface sediments with 7.2, 0.26, 0.14, and 1.6 ng/g dw for Deca-, Nona-, Octa-, and the sum of Tri-HeptaBDE, respectively. While DecaBDE and NonaBDE were found to increase rapidly, the increase of OctaBDE was slower. Congener patterns of Octa- and NonaBDE present in sediments of Greifensee did not change with time. Consequently, there was no evidence for sediment mediated long-term transformation of PBDE within the observed time span of almost 30 years. Despite the high persistence of DecaBDE, environmental debromination occurs, as shown by the detection of a shift in congener patterns of Octa- and NonaBDE in sediments, compared to the respective congener patterns in technical PBDE products. The OctaBDE congener BDE-202 was detected in sediments, representing a transformation product that is not reported in any of the technical PBDE products. Comparison of OctaBDE congener patterns in sediments with OctaBDE congener patterns from known sources reveals that (i) they were distinctively different from the congener patterns in technical PBDE products and (ii) that they were similar to the OctaBDE patterns in house dust and photodegradation products of DecaBDE, suggesting contributions from these sources.     

Organic aerosol spatial/temporal patterns: perspectives of measurements and model

Ambient measurements from SEARCH and model results from CMAQ-MADRID are analyzed side by side for the southeastern United States to understand the strengths and weaknesses of an air quality model in reproducing key spatial and temporal patterns related to organic aerosol (OA), with inferences regarding secondary organic aerosol (SOA). The model predicts a larger difference in OA concentrations between an urban (JST) and a rural site (YRK) than indicated by measurements. Modeled OA concentrations at JST and YRK are more strongly correlated than measurements. On average, models may understate urban OA emissions, while overstating urban SOA production; measurements indicate that SOA production takes place on the regional scale. Modeled diurnal fluctuations for OA are stronger than measured, due partially to overestimations of the temperature dependence parameters (deltaH(vap)) for SOA in the model. Urban-rural differences in the composition of SOA, inferred from the variations of estimated deltaH(vap), are not properly captured by the model, which does not represent multiple generations of SOA or varied reaction pathways as a function of chemical regimes. Model results are hampered by day-of-the-week and diurnal allocation issues related to EC and OA emissions. Top quintile (20%) afternoon OA concentrations are observed in both warm and cold seasons at the urban site. The frequency of high OA in the cold season is overstated in the model. The model predicts the warm vs cold season frequency of elevated OA episodes better at YRK than at JST, suggesting that regional emissions, chemistry, and transport are better simulated than urban processes.     

Purification and characterisation of relevant natural and recombinant apple allergens

Apple (Malus domestica) is the most widely cultivated fruit crop in Europe and frequently causes allergic reactions with a variable degree of severity. So far, four apple allergens Mal d 1, Mal d 2, Mal d 3 and Mal d 4 have been identified. Mal d 1, a Bet v 1 related allergen, and Mal d 4, apple profilin, are sensitive to proteolytic degradation, whereas Mal d 2, a thaumatin-like protein and Mal d 3, a nonspecific lipid transfer protein, are rather stable to proteolytic processes. Mal d 1 and Mal d 4 were purified after expression in Escherichia coli expression system, while Mal d 2 and Mal d 3 were purified from apple fruit tissue. All purified proteins were subjected to detailed physicochemical characterisation to confirm their structural integrity and maintained IgE binding capacity. Detailed investigations of carbohydrate moieties of Mal d 2 demonstrated their involvement in the overall IgE binding capacity of this allergen. It was concluded that the folded structure and IgE binding capacity of all four allergens were preserved during purification.     

Short communication: Genomic prediction using imputed whole-genome sequence variants in Brown Swiss Cattle

The accuracy of genomic prediction determines response to selection. It has been hypothesized that accuracy of genomic breeding values can be increased by a higher density of variants. We used imputed whole-genome sequence data and various single nucleotide polymorphism (SNP) selection criteria to estimate genomic breeding values in Brown Swiss cattle. The extreme scenarios were 50K SNP chip data and whole-genome sequence data with intermediate scenarios using linkage disequilibrium-pruned whole-genome sequence variants, only variants predicted to be missense, or the top 50K variants from genome-wide association studies. We estimated genomic breeding values for 3 traits (somatic cell score, nonreturn rate in heifers, and stature) and found differences in accuracy levels between traits. However, among different SNP sets, accuracy was very similar. In our analyses, sequence data led to a marginal increase in accuracy for 1 trait and was lower than 50K for the other traits. We concluded that the inclusion of imputed whole-genome sequence data does not lead to increased accuracy of genomic prediction with the methods.     

A Liquid Silazane Precursor To Silicon Nitride

The reaction of dichlorosilane, H₂SiCl₂, with gaseous NH₃ in dichloromethane or diethyl ether solution results in the formation of a silazane oil containing silicon, hydrogen, and nitrogen in good yield. This ammonolysis product can be pyrolyzed in an N₂ atmosphere (temperature to 1150°C) to give α-Si₃N₄ in ∼70% yield. The ceramic product formed has a relatively porous, fine-grained microstructure with some cracks and blisters.     

Surface protection of poly(vinyl chloride) by photografting of epoxy–acrylate coatings

UV-curable epoxy–acrylate coatings were used to protect poly(vinyl chloride) against superficial degradation. With α-hydroxy–acetophenone photoinitiators, the crosslinking polymerization develops in the ms time scale; 50% degree conversion is reached after irradiation times of 2.5 ms in a nitrogen atmosphere and 17 ms in air. The adhesion of the coating on to the PVC substrate can be greatly improved by inducing a photochemical grafting process. The best results are obtained by incorporating the photoinitiator into the top layer of the PVC sheet. Highly crosslinked epoxy–acrylate coatings are very stable toward UV radiations and chemical agents like organic solvents and strong acids. By their light-screening effect they provide an excellent protection against photodegradation for light-sensitive polymeric materials.