This study investigated the question of whether a student's expectancy, values and negative affect influenced their deep information processing approach and achievement at the end of the first and ...second academic year. Five hundred and sixty-five first-year students completed a self-report questionnaire on three different occasions. The departmental administrations provided data on the students' achievement. Covariance analysis indicated that student's expectancy and values positively affected the total number of credits. However, the expected relationship through the deep information processing approach was not found. Even though the analysis showed a relationship between students' expectancy, values and the deep information processing approach, this approach did not affect academic achievement.
The induction of plant defences involves a sequence of steps along a signal transduction pathway, varying in time course. In this study, the effects of induction of an early and a later step in plant ...defence signal transduction on plant volatile emission and parasitoid attraction are compared. Ion channel-forming peptides represent a class of inducers that induce an early step in signal transduction. Alamethicin (ALA) is an ion channel-forming peptide mixture from the fungus Trichoderma viride that can induce volatile emission and increase endogenous levels of jasmonic acid (JA) and salicylic acid in plants. ALA was used to induce an early step in the defence response in Brussels sprouts plants, Brassica oleracea var. gemmifera, and to study the effect on volatile emission and on the behavioural response of parasitoids to volatile emission. The parasitoid Cotesia glomerata was attracted to ALA-treated plants in a dose-dependent manner. JA, produced through the octadecanoid pathway, activates a later step in induced plant defence signal transduction, and JA also induces volatiles that are attractive to parasitoids. Treatment with ALA and JA resulted in distinct volatile blends, and both blends differed from the volatile blends emitted by control plants. Even though JA treatment of Brussels sprouts plants resulted in higher levels of volatile emission, ALA-treated plants were as attractive to C. glomerata as JA-treated plants. This demonstrates that on a molar basis, ALA is a 20 times more potent inducer of indirect plant defence than JA, although this hormone has more commonly been used as a chemical inducer of plant defence.
Bacterial cell surfaces play a crucial role in their adhesion to surfaces. In the present study, physico-chemical cell surface properties of
Pseudomonas aeruginosa, isolated from a case of contact ...lens associated keratitis, are determined for mid-exponential and early stationary phase cells and for cells after exposure to a lens care solution or after mechanical damage by sonication. Exposure to a lens care solution and mechanical cell surface damage reduced the cell surface hydrophobicity and water contact angles decreased from 129° to 96° and 83°, respectively. Zeta potentials in saline (−9 mV) were hardly affected after mechanical damage, but tri-modal zeta potential distributions, with subpopulation zeta potentials at −11, −28 and −41 mV, were observed after exposure of bacteria to a lens care solution. X-ray photoelectron spectroscopy indicated changes in the amounts of oxygen-, nitrogen- and phosphorus-rich cell surface components. Mid-exponential phase cells had more nitrogen-rich cell surface components than early stationary phase cells, but water contact angles and zeta potentials were not very different. In addition, mid-exponential phase cells adhered better than early stationary phase cells to hydrophobic and hydrophilic substrata in a parallel plate flow chamber. The capacity of
P. aeruginosa to adhere was decreased after inflicting cell surface damage. Exposure to a lens care solution yielded a larger reduction in adhesion capacity than sonication, likely because sonication left most of the cells in a viable state, in contrast to exposure to a lens care solution. It is argued that for clinically relevant experiments, it may be preferable to work with surface damaged cells rather than with gently harvested organisms.
Worldwide outbreaks of pospiviroids in potato and tomato have increased the need for a reliable test for the detection of pospiviroids in seeds. This study describes the development and validation of ...a sensitive and fast test for the detection of Potato spindle tuber viroid (PSTVd) and Tomato chlorotic dwarf viroid (TCDVd) in tomato seeds. The test is based on RNA isolation using a commercial kit and is suitable for routine application. The test is able to detect one PSTVd or TCDVd contaminated seed in sub samples of 1000 seeds and results were both repeatable and reproducible.
Détection du PSTVd et du TCDVd dans les semences de tomates au moyen de la RT‐PCR en temps réel
La présence dans le monde entier de foyers de pospiviroïdes dans les cultures de pommes de terre et de tomates ont accru le besoin d'un test fiable de détection des pospiviroïdes dans les semences. Cette étude décrit la mise au point et la validation d'un test sensible et rapide pour la détection du Potato spindle tuber viroid (PSTVd) et du Tomato chlorotic dwarf viroid (TCDVd) dans les semences de tomates. Le test est basé sur l'isolation d'ARN au moyen d'un kit vendu dans le commerce, et peut être utilisé en routine. Le test est capable de détecter une semence contaminée par le PSTVd ou le TCDVd dans un sous‐échantillon de 1000 semences, et les résultats peuvent être répétés et reproduits.
Bыявлeниe PSTVd и TCDVd в ceмeнax тoмaтa c пoмoщью ПЦP в peaльнoм вpeмeни
Oтмeчaeмыe вo вceмиpнoм мacштaбe вcпышки пocпивиpoидoв нa кapтoфeлe и тoмaтe пoвыcили нeoбxoдимocть paзpaбoтки нaдeжнoгo мeтoдa тecтиpoвaния для выявлeния пocпивиpoидoв в ceмeнax этиx pacтeний. B cтaтьe дaeтcя oпиcaниe paзpaбoтки и вaлидaции дocтaтoчнo чyвcтвитeльнoгo oпepaтивнoгo тecтa для выявлeния в ceмeнax тoмaтa Potato spindle tuber viroid (PSTVd) и Tomato chlorotic dwarf viroid (TCDVd). Tecт бaзиpyeтcя нa изoляции PHК c пoмoщью cтaндapтнoгo нaбopa и пoдxoдит для pyтиннoгo пpимeнeния. B выбopкax из 1 000 ceмян этoт тecт пoзвoляeт oбнapyжить oднo ceмя, пopaжeннoe PSTVd или TCDVd; пpи этoм peзyльтaты были пoвтopяющимиcя и вocпpoизвoдимыми.
Plants respond to herbivory with the emission of induced plant volatiles. These volatiles may attract parasitic wasps (parasitoids) that attack the herbivores. Although in this sense the emission of ...volatiles has been hypothesized to be beneficial to the plant, it is still debated whether this is also the case under natural conditions because other organisms such as herbivores also respond to the emitted volatiles. One important group of organisms, the enemies of parasitoids, hyperparasitoids, has not been included in this debate because little is known about their foraging behaviour. Here, we address whether hyperparasitoids use herbivore-induced plant volatiles to locate their host. We show that hyperparasitoids find their victims through herbivore-induced plant volatiles emitted in response to attack by caterpillars that in turn had been parasitized by primary parasitoids. Moreover, only one of two species of parasitoids affected herbivore-induced plant volatiles resulting in the attraction of more hyperparasitoids than volatiles from plants damaged by healthy caterpillars. This resulted in higher levels of hyperparasitism of the parasitoid that indirectly gave away its presence through its effect on plant odours induced by its caterpillar host. Here, we provide evidence for a role of compounds in the oral secretion of parasitized caterpillars that induce these changes in plant volatile emission. Our results demonstrate that the effects of herbivore-induced plant volatiles should be placed in a community-wide perspective that includes species in the fourth trophic level to improve our understanding of the ecological functions of volatile release by plants. Furthermore, these findings suggest that the impact of species in the fourth trophic level should also be considered when developing Integrated Pest Management strategies aimed at optimizing the control of insect pests using parasitoids.
Purpose
The purpose of the study was to explore relatives’ descriptions and experiences of continuous sedation in end-of-life care for cancer patients and to identify and explain differences between ...respondents from the Netherlands, Belgium, and the UK.
Methods
In-depth interviews were held between January 2011 and May 2012 with 38 relatives of 32 cancer patients who received continuous sedation until death in hospitals, the community, and hospices/palliative care units.
Results
Relatives’ descriptions of the practice referred to the outcome, to practical aspects, and to the goals of sedation. While most relatives believed sedation had contributed to a ‘good death’ for the patient, yet many expressed concerns. These related to anxieties about the patient’s wellbeing, their own wellbeing, and questions about whether continuous sedation had shortened the patient’s life (mostly UK), or whether an alternative approach would have been better. Such concerns seemed to have been prompted by relatives witnessing unexpected events such as the patient coming to awareness during sedation. In the Netherlands and in Belgium, several relatives reported that the start of the sedation allowed for a planned moment of ‘saying goodbye’. In contrast, UK relatives discerned neither an explicit point at which sedation was started nor a specific moment of farewell.
Conclusions
Relatives believed that sedation contributed to the patient having a good death. Nevertheless, they also expressed concerns that may have been provoked by unexpected events for which they were unprepared. There seems to exist differences in the process of saying goodbye between the NL/BE and the UK.
Non-contact plaque removal offers advantages in interproximal spaces, fissures, and pockets. It requires the generation of strong fluid flows and the inclusion of air bubbles to become effective. A ...pair of co-adhering streptococci and actinomyces has been used previously to demonstrate non-contact removal by sonic brushing. Here we determined the influence of the sequence of co-adhesion of streptococci and actinomyces on non-contact removal from a salivary pellicle by rotary and sonic brushing. After bacterial adhesion, pellicles were brushed in a wet and immersed state, with a distance up to 4 mm to the bristle tips. Bacteria adhering to pellicles from the sequence streptococci followed by actinomyces appeared more difficult to remove and left more large co-aggregates than from the sequence actinomyces followed by streptococci. At contact, rotary and sonic brushing performed equally well in bacterial removal, while at 4 mm, both had lost some efficacy.
Several factors in the H. J. Walberg Educational Productivity Model, which assumes that 9 factors affect academic achievement, were examined with a limited sample of 1st-year students in the ...University of Groningen. Information concerning 8 of these factors-grades, motivation, age, prior achievement, home environment, support from peers, classroom environment, quality of instruction, and quantity of instruction-was collected through the departmental administration, self-report questionnaires, rating questionnaires, and through paper sources. A multilevel analysis showed that the model with 8 productivity factors explained 23% of the variance found in achievement, as well as the variables prior achievement and expectancy, the classroom environment, the quality of assessment, and the quantity of instruction affected achievement. (DIPF/Orig.).
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