Molecular effects of resistance elicitors from biological origin and their potential for crop protection

Plants contain a sophisticated innate immune network to prevent pathogenic microbes from gaining access to nutrients and from colonising internal structures. The first layer of inducible response is governed by the plant following the perception of microbe- or modified plant-derived molecules. As the perception of these molecules results in a plant response that can provide efficient resistance towards non-adapted pathogens they can also be described as ‘defence elicitors’. In compatible plant/microbe interactions, adapted microorganisms have means to avoid or disable this resistance response and promote virulence. However, this requires a detailed spatial and temporal response from the invading pathogens. In agricultural practice, treating plants with isolated defence elicitors in the absence of pathogens can promote plant resistance by uncoupling defence activation from the effects of pathogen virulence determinants. The plant responses to plant, bacterial, oomycete or fungal-derived elicitors are not, in all cases, universal and need elucidating prior to the application in agriculture. This review provides an overview of currently known elicitors of biological rather than synthetic origin and places their activity into a molecular context

Teachers\u27 literacy beliefs and their students\u27 conceptions about reading and writing

This investigation examined first-grade teachers\u27 literacy beliefs and practices and its relationship with their students\u27 conceptions about reading and writing. For the first part of the study a sample of 76 first-grade teachers, from two school districts in Puerto Rico, completed the Literacy Orientation Survey (LOS). The combined score of the LOS was calculated and used to categorize teachers according to their literacy beliefs and practices as constructivist, eclectic, or traditional. After matching by years of experience and educational level, a stratified random sample of six teachers, two from each literacy viewpoint (traditional, eclectic, and constructivist), and 48 first-grade students was selected to participate in the second part of the study. A simple random sample of eight students (four low-achieving readers and four high-achieving readers) was selected from the classrooms of each of the six teachers, who represented the three differing literacy beliefs. Individual interviews were conducted with the students, using Wing\u27s (1989) interview protocol, in order to assess their conceptions of reading and writing. The results of this study regarding the nature of teachers\u27 literacy beliefs indicated that most teachers appear to hold traditional literacy beliefs and practices, whereas a very small number of the participant teachers seem to hold literacy beliefs and practices categorized as constructivist. A statistical significant association was found between teachers\u27 literacy viewpoint and students\u27 conceptions about reading and writing. First-grade students whose teachers held a constructivist literacy viewpoint seemed to have more holistic conceptions of literacy, whereas students whose teachers held a traditional or an eclectic literacy viewpoint seemed to have more skills or test-based conceptions of reading and writing. Results indicate that first-grade students\u27 ideas regarding the purposes and nature of reading and writing appear to be compatible with their teachers\u27 literacy beliefs and practices. No significant relationship was found between students\u27 conceptions of reading and writing and their reading ability. Implications for literacy teaching, learning, and further research are discussed

Phenyl-type and C1 stationary phases for environmentally friendlier chromatography

C1 and phenyl-type stationary phases were assessed in terms of their environmental impact on separations using as test solutes polycyclic aromatic hydrocarbons. Methanol (MeOH) and acetonitrile (ACN) mobile-phase gradients were employed. These stationary phases were examined to determine if different physical and chemical properties possessed by these surfaces decreased the organic solvent consumption, and yet maintained peak capacity. The cumulative energy demand (CED) was used to gauge the environmental impact of the separations. The separation of the polycyclic aromatic hydrocarbon test mixture using current methodologies (i.e. a C18/ACN combination) had a CED of 1.13&thinsp;MJ-eq, and a peak capacity of 27 peaks (resolving 7 of 12 peak pairs with Rs&gt;1). In comparison, a butyl phenyl stationary phase with a methanol mobile phase had a peak capacity of 26, but with a CED of 0.670&thinsp;MJ-eq. Monolithic columns containing C18 and C1 phases were also tested. A monolithic C18 column with MeOH had the lowest CED at 0.675&thinsp;MJ-eq, a peak capacity of 28 peaks and good resolving power (resolving ten peak pairs with Rs&gt;1), suggesting that this is a viable option with respect to reducing environmental impact for these types of analyses.<br /

The fundamental plane of early-type galaxies

We report recent results from the photometric follow-up study we are conducting in the context of the SAURON project. We use ground-based MDM V -band and Spitzer/IRAC 3.6 μm imaging to characterise our sample of E, S0 and Sa galaxies photometrically. Combined with SAURON integral-field spectroscopic observations, this information allows us to explore and understand the location of these galaxies on the Fundamental Plane relation, providing an important diagnostic tool to study their formation and evolution