Monitoring neonicotinoid resistance in biotype B of Bemisia tabaci in Florida

BACKGROUND: Biotype B of the sweetpotato whitefly, Bemisia tabaci (Genn.), is a worldwide pest that has developed resistance to many insecticides, including the neonicotinoid class. Florida field populations were monitored for susceptibility to the neonicotinoids imidacloprid and thiamethoxam using a cut leaf petiole bioassay method. RESULTS: Average RR₅₀ values for imidacloprid increased from 3.7 in 2000 to 12.0 in 2003; decreased to 5.0 and 2.5 in 2004 and 2005, respectively; and then increased to 26.3 and 23.9 in 2006 and 2007, respectively. Populations with RR₅₀ values of about 50 to 60 during generation one reverted to RR₅₀ values of ?4 in six generations, when reared without further exposure to imidacloprid. Average RR₅₀ values for thiamethoxam increased from 2.0 in 2003 to 24.7 in 2006 and decreased to 10.4 in 2007. Populations with RR₅₀ values of about 22, 32 and 53 during generation one declined to 8, 5 and 6, respectively, after being reared for five generations without exposure to thiamethoxam. The correlation coefficient from the 26 populations that were bioassayed both with imidacloprid and thiamethoxam showed a significant positive correlation (R² = 0.58) between these populations. CONCLUSION: The high level of RR₅₀ values to imidacloprid and thiamethoxam suggest an unstable decline in the susceptibility of B. tabaci to imidacloprid and thiamethoxam, with possible cross‐resistance or predisposition for dual resistance selection. Copyright © 2009 Society of Chemical Industry     

沙门氏菌的控制成为焦点问题

食品安全是当今世界最重要的公共卫生问题之一,它越来越受到政治家和立法者的关注。因此,从原料的生产商到食品的加工商和零售商间的整个食品生产流通环节,都必须采取有效的且具有成本效益的措施防止病原体的污染。     

Hot cognition in agricultural policy preferences in Norway?

The paper tests the hypothesis that cultural and social background is far more influential to form preferences about policy than the level of fact-based knowledge a person possesses. The data for the case study stem from a web-based survey among a representative sample of the adult population in Norway. The degree of knowledge of agriculture in this paper is operationalized through questions on five key characteristics of Norwegian agriculture that frequently arise in the public discussion. The results show that the amount of fact-based knowledge of agriculture to a very little extent explains differences within the sample. The cultural background of respondents is much more suited to explain agricultural policy preferences. Knowledge, however, shifts the attention from food price issues towards the delivery of public goods. The results allow us to hint at hot cognition as a possible explanation for such findings.     

Characterization of refractory organic substances by NEXAFS using a compact X-ray source

Purpose  

We present the characterization of environmental samples using near-edge X-ray absorption fine structure (NEXAFS) spectra recorded with an in-house device. We want to point out the feasibility of such an easily accessed complementary technique, if not sometimes alternative to NEXAFS studies performed with synchrotron radiation, as the number of compact setups is increasing.     

Effects of a Novel Barley,Himalaya 292, on Rheological and Breadmaking Properties of Wheat and Barley Doughs

A barley mutant with high‐amylose starch, Himalaya 292, combines the potential cholesterol reducing effects of barley with the gastrointestinal benefits of high‐amylose resistant starches. Himalaya 292 has alterations in the content and composition of a range of grain constituents, thus conditions for successful addition to foods need to be defined. In this study, the rheological and breadmaking properties of doughs prepared by combining wheat flours (with various gluten protein compositions) with various barley genotypes (Himalaya 292 and the control cultivars Himalaya and Torrens) have been determined. The effects of barley addition on the rheological properties of the admixtures differed. While addition of Himalaya 292 increased the strength and reduced the extensibility of admixture doughs, addition of the Himalaya and Torrens barley flours to the wheat flours reduced both strength and extensibility. The addition of Himalaya and Torrens barley flour reduced water absorption levels. However, addition of Himalaya 292 whole grain flour increased the water absorption of the admixtures significantly (P < 0.01). The baking data showed that selection of an appropriate wheat flour with a combination of strength and extensibility allows higher levels of incorporation of barley, facilitating an increased delivery per serving of constituents with positive health attributes in β‐glucan and resistant starch.