Effect of iridoid glycoside content on oviposition host plant choice and parasitism in a specialist herbivore

The Glanville fritillary butterfly Melitaea cinxia feeds upon two host plant species in Å land, Finland, Plantago lanceolataand Veronica spicata, both of which produce iridoid glycosides. Iridoids are known to deter feeding or decrease the growth rate of many generalist insect herbivores, but they often act as oviposition cues to specialist butterflies and are feeding stimulants to their larvae. In this study, two iridoid glycosides (aucubin and catalpol) were analyzed by micellar electrokinetic capillary chromatography. We measured the spatial and temporal variation of iridoid glycosides in natural populations of the host plants of M. cinxia. We also analyzed the aucubin and catalpol content in plants in relation to their use by ovipositing females, and in relation to the incidence of parasitism of M. cinxia larvae in natural populations. The mean concentrations of aucubin and catalpol were higher in P. lanceolata than in V. spicata, and catalpol concentrations were higher than aucubin concentrations in both host species. Plantago lanceolata individuals that were used for oviposition by M. cinxia had higher aucubin concentrations than random plants and neighboring plants. Additionally, oviposition and random plants had higher catalpol concentrations than neighboring plants, indicating that ovipositing females select for high iridoid glycoside plants or that oviposition induces iridoid glycoside production in P. lanceolata. Parasitism by the specialist parasitoid wasp Cotesia melitaearum occurred most frequently in larval groups that were feeding on plants with low concentrations of catalpol, irrespective of year, population, and host plant species. Therefore, parasitoids appear to avoid or perform poorly in host larvae with high catalpol content.     

Ancillary benefits of climate policy in a small open economy: The case of Sweden

It is increasingly recognised that GHG reduction policies can have important ancillary benefits in the form of positive local and regional environmental impacts. The purpose of this paper is to estimate the domestic ancillary pollution benefits of climate policy in Sweden, and investigate how these are affected by different climate policy designs. The latter differ primarily in terms of how the country chooses to meet a specific target and where the necessary emission reductions take place. The analysis relies on simulations within the energy system optimisation model TIMES-Sweden, and focuses on four non-GHG pollutants: Nitrogen Oxides (NO_X), Non Methane Volatile Organic Compounds (NMVOC), inhalable particles (PM_2.5), and Sulphur dioxide (SO₂). The simulations permit detailed assessments of the respective technology and fuel choices that underlie any net changes in the estimated ancillary effects. The results indicate that the ancillary benefits constitute a far from insignificant share of total system costs, and this share appears to be highest in the scenarios that entail the largest emission reductions domestically. This result reflects the fact that carbon dioxide emission reductions abroad also implies a lost opportunity of achieving substantial domestic welfare gain from the reductions of regional and local environmental pollutants.     

Reduction of Campylobacter jejuni counts on chicken meat treated with different seasonings

To analyze the potential of various seasoning combinations in reducing Campylobacter jejuni counts on fresh chicken meat, fresh chicken drumstick samples were inoculated with a mixture of two C. jejuni strains at log 4–5 CFU/g and subsequently treated with six different seasonings. After addition as a dry powder to the meat’s surface, all seasoning combinations adsorbed water from the meat and formed a gel on the meat’s surface. The samples were placed in individual packages containing a modified gas atmosphere (N₂ 80% and CO₂ 20%) and stored at 4 °C for seven days and C. jejuni counts in CFU/g were determined at the beginning, after 15 min, 1 h, 1 day and 7 days. The most effective seasoning combination contained, among other ingredients and food additives, sodium lactate and potato protein fractions; it reduced counts by mean 1.52 to 1.66 log CFU/g in seven days. The other seasoning combinations without potato protein fractions decreased counts in the range of mean 1.05 to 1.16 log CFU/g; simultaneously, the counts in control meat samples decreased by mean 0.21 log CFU/g. The death rate estimates after 1 h storage was in the range of ?0.25 log CFU/g/h to ?0.34 log CFU/g/h.In conclusion, various combinations of seasonings decreased the counts of C. jejuni, with the highest C. jejuni death rate during the first hour and further minor reductions in C. jejuni counts with additional storage time. These types of treatments may decrease human exposure to Campylobacter from fresh poultry meat.     

Tracing Campylobacter jejuni strains along the poultry meat production chain from farm to retail by pulsed-field gel electrophoresis, and the antimicrobial resistance of isolates

In this study Campylobacter jejuni isolates were recovered from birds, carcasses and carcass portions from two broiler chicken flocks and from equipment used for carcass and meat processing along the production chain from farms to retail stores. Isolates were subjected to pulsed-field gel electrophoresis (PFGE) using SmaI and KpnI restriction enzymes and their antimicrobial susceptibilities were determined. C. jejuni was recovered from product and equipment used with both flocks at each point in the production chain. The prevalence of C. jejuni in poultry products at retail stores was 58.97% (flock 1) and 69.23% (flock 2). SmaI divided 122 C. jejuni strains from flock 1 and 106 from flock 2 into 17 and 13 PFGE types, respectively. PFGE types H and F were present at all steps along the chain, from farms to retail products. Similarly, for both flocks PFGE type D was detected in crates, slaughterhouse and retail stores. Moreover, the PFGE types were highly diverse at the processing and retail steps. Most PFGE types were resistant to ciprofloxacin (95.45%) and tetracycline (81.82%); and multidrug resistant PFGE types were found in the final products. Our study showed that there were several points of cross-contamination of product along the chain, and a high diversity of PFGE types with antimicrobial resistance to ciprofloxacin and tetracycline in the retail products.     

The occurrence of Campylobacter spp. in Estonian broiler chicken production in 2002–2007

The aim of the present study was to monitor the occurrence of Campylobacter spp. in broiler chicken production in Estonia from 2002 to 2007. Campylobacter spp. was isolated in 163 (12.3%) of 1320 broiler chicken meat samples form 2002 to 2007 and in 115 (6.3%) of 1819 cecal samples in 2005–2007. Campylobacter jejuni was the most commonly isolated species (98.2%), followed by Campylobacter coli (1.4%) and Campylobacter lari (0.4%). The seasonal peak of Campylobacter contamination was from July to September. Our findings showed that Campylobacter contamination at all levels of broiler chicken production in Estonia was low.     

Prevalence and genetic characterization of Listeria monocytogenes in retail broiler meat in Estonia

The prevalence and genetic diversity of Listeria monocytogenes in raw broiler legs at the retail level in Estonia were studied. A total of 240 raw broiler legs (120 from Estonia and 120 of foreign origin, which had been imported to Estonia from Denmark, Finland, Hungary, Sweden, and the United States) from 12 retail stores in the two largest cities in Estonia (Tallinn and Tartu) were investigated from January to December 2002. Of these, 70% were positive for L. monocytogenes. The prevalence of L. monocytogenes in broiler legs of Estonian origin (88%) was significantly higher than in broiler legs of foreign origin (53%) (P < 0.001). Altogether, 169 (106 Estonian and 63 imported) L. monocytogenes isolates were characterized by pulsed-field gel electrophoresis (PFGE) typing after treatment with the restriction enzyme AscI. The isolates showed a wide genetic diversity, with 35 different PFGE types obtained. Of these, 11 PFGE types came only from isolates of broiler legs of Estonian origin, 4 of Danish origin, 2 of Finnish origin, and 4 of Hungarian origin. Fourteen PFGE types came from isolates of broiler legs that originated from various countries. The strains that shared the same PFGE types from isolates of Estonian origin were recovered from broiler legs that came from different stores over the course of several months. Seventy-one L. monocytogenes isolates, including all PFGE types, were serotyped, and three serotypes (1/2a, 1/2b, and 4b) were obtained. Serotype 1/2a accounted for 96% of the isolates.     

The factor structure and factorial invariance of the 12-item General Health Questionnaire (GHQ-12) across time: Evidence from two community-based samples.

This study provides new knowledge about the factor structure of the 12-item General Health Questionnaire (GHQ-12; D. Goldberg, 1972) through the application of confirmatory factor analysis to longitudinal data, thereby enabling investigation of the factor structure, its invariance across time, and the rank-order stability of the factors. Two community-based longitudinal adult samples with 1-year (n = 640) and 6-year (n = 330) follow-up times were studied. As a result, the correlated 3-factor model (i.e., Anxiety/Depression, Social Dysfunction, and Loss of Confidence) showed a better fit with both samples than the alternative models. The correlated 3-factor structure was also relatively invariant across time in both samples, indicating that the scale has good construct validity. The rank-order stabilities of the factors were low across time, which suggests that the GHQ-12 measures temporal mental state. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

楼宇电梯配置和目标选层系统

楼宇内的电梯配置取决于上行高峰和运输能力的计算结果，以满足楼宇内运输流量的需求。基于上行，下行呼梯按钮的集选控制系统，考虑到电梯运输能力时上行高峰是最需要满足的交通工况。如果电梯可以满足上行高峰状况，电梯就具有足够的运输能力满足其他运行状况。使用安装在大厅的目标选层系统（DCS），在上行高峰的状况下，电梯的运输能力可以达到与下行高峰相近的水平。用于常规集选控制下的计算上行高峰往返行程时间的方程式是无效的。在本篇文章中，介绍了一种使用DCS控制系统来选配电梯的方法．使得电梯在任何运输状况下都提供良好的服务。     

Selectivity in capillary electrophoresis in the presence of micelles, chiral selectors and non-aqueous media

In addition to high efficiency, short analysis times and small sample volumes, a further attractive feature of capillary electrophoretic techniques is the possibility to achieve, high selectivities. Usually, selectivity control also allows improvement in the resolution. A simple way to enhance the selectivity of capillary electrophoretic separations is to add one or more surfactants above their critical micelle concentration, or in the case of chiral separations to add a chiral selector to the background electrolyte. Because of the dynamic structure of micelles, the aggregation of monomers and size of the micelles can be easily adjusted. This review describes the various type of surfactants used in micellar electrokinetic capillary chromatography, and the chiral selectors employed in enantiomeric separations by capillary electrophoresis. Factors affecting the selectivity are noted. A brief discussion is included of the selectivity enhancement obtainable in non-aqueous media.