475 research outputs found

    Narratives of Industry Responses to Cyberbullying: Perspectives on Self-regulation From and About the Industry

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    In this chapter, we provide an overview of narratives about online inter- mediaries’ responses to cyberbullying from the perspectives of policy makers and the companies, as well as children and parents. Relevant self-regulatory and self- organisational efforts are discussed aswell as the rationales for their adoption; includ- ing how the effectiveness of these efforts is seen from the perspectives of various stakeholders. We draw attention to the relative paucity of data on effectiveness of companies’ mechanisms, particularly from the perspective of any benefits received by children as a result of these interventions and support

    Estimation of the solubility parameters of model plant surfaces and agrochemicals: a valuable tool for understanding plant surface interactions

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    Background Most aerial plant parts are covered with a hydrophobic lipid-rich cuticle, which is the interface between the plant organs and the surrounding environment. Plant surfaces may have a high degree of hydrophobicity because of the combined effects of surface chemistry and roughness. The physical and chemical complexity of the plant cuticle limits the development of models that explain its internal structure and interactions with surface-applied agrochemicals. In this article we introduce a thermodynamic method for estimating the solubilities of model plant surface constituents and relating them to the effects of agrochemicals. Results Following the van Krevelen and Hoftyzer method, we calculated the solubility parameters of three model plant species and eight compounds that differ in hydrophobicity and polarity. In addition, intact tissues were examined by scanning electron microscopy and the surface free energy, polarity, solubility parameter and work of adhesion of each were calculated from contact angle measurements of three liquids with different polarities. By comparing the affinities between plant surface constituents and agrochemicals derived from (a) theoretical calculations and (b) contact angle measurements we were able to distinguish the physical effect of surface roughness from the effect of the chemical nature of the epicuticular waxes. A solubility parameter model for plant surfaces is proposed on the basis of an increasing gradient from the cuticular surface towards the underlying cell wall. Conclusions The procedure enabled us to predict the interactions among agrochemicals, plant surfaces, and cuticular and cell wall components, and promises to be a useful tool for improving our understanding of biological surface interactions

    Esperanto for histones : CENP-A, not CenH3, is the centromeric histone H3 variant

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    The first centromeric protein identified in any species was CENP-A, a divergent member of the histone H3 family that was recognised by autoantibodies from patients with scleroderma-spectrum disease. It has recently been suggested to rename this protein CenH3. Here, we argue that the original name should be maintained both because it is the basis of a long established nomenclature for centromere proteins and because it avoids confusion due to the presence of canonical histone H3 at centromeres

    Attempts to Image the Early Inflammatory Response during Infection with the Lymphatic Filarial Nematode Brugia pahangi in a Mouse Model

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    Helminth parasites remain a major constraint upon human health and well-being in many parts of the world. Treatment of these infections relies upon a very small number of therapeutics, most of which were originally developed for use in animal health. A lack of high throughput screening systems, together with limitations of available animal models, has restricted the development of novel chemotherapeutics. This is particularly so for filarial nematodes, which are long-lived parasites with a complex cycle of development. In this paper, we describe attempts to visualise the immune response elicited by filarial parasites in infected mice using a non-invasive bioluminescence imaging reagent, luminol, our aim being to determine whether such a model could be developed to discriminate between live and dead worms for in vivo compound screening. We show that while imaging can detect the immune response elicited by early stages of infection with L3, it was unable to detect the presence of adult worms or, indeed, later stages of infection with L3, despite the presence of worms within the lymphatic system of infected animals. In the future, more specific reagents that detect secreted products of adult worms may be required for developing screens based upon live imaging of infected animals

    Invaders in hot water: a simple decontamination method to prevent the accidental spread of aquatic invasive non-native species.

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    Watersports equipment can act as a vector for the introduction and spread of invasive non native species (INNS) in freshwater environments. To support advice given to recreational water users under the UK Government’s Check Clean Dry biosecurity campaign and ensure its effectiveness at killing a range of aquatic INNS, we conducted a survival experiment on seven INNS which pose a high risk to UK freshwaters. The efficacy of exposure to hot water (45 °C, 15 min) was tested as a method by which waters users could ‘clean’ their equipment and was compared to drying and a control group (no treatment). Hot water had caused 99 % mortality across all species 1 h after treatment and was more effective than drying at all time points (1 h: χ2 = 117.24, p < 0.001; 1 day χ2 = 95.68, p < 0.001; 8 days χ2 = 12.16, p < 0.001 and 16 days χ2 = 7.58, p < 0.001). Drying caused significantly higher mortality than the control (no action) from day 4 (χ2 = 8.49, p < 0.01) onwards. In the absence of hot water or drying, 6/7 of these species survived for 16 days, highlighting the importance of good biosecurity practice to reduce the risk of accidental spread. In an additional experiment the minimum lethal temperature and exposure time in hot water to cause 100 % mortality in American signal crayfish (Pacifastacus leniusculus), was determined to be 5 min at 40 °C. Hot water provides a simple, rapid and effective method to clean equipment. We recommend that it is advocated in future biosecurity awareness campaigns

    Impaired performance of alpha7 nicotinic receptor knockout mice in the five-choice serial reaction time task

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    RATIONALE: Nicotinic receptors have been implicated in attentional performance. Nicotine can improve attention in animals and humans, but knowledge about relevant receptor subtypes is very limited. OBJECTIVES: The aim was to examine the role of α7 receptors in attentional performance of mice and in effects of nicotine. MATERIALS AND METHODS: Mice with targeted deletion of the gene coding for the α7 subunit of nicotinic receptors and wild-type controls were trained on a five-choice serial reaction time task with food reinforcers presented under varying parametric conditions. Nicotine was administered in a range of doses (0.001–1.0 mg/kg sc), including those reported to enhance attentional performance. RESULTS: Initially the α7(−/−) (knockout) mice responded less accurately and made more anticipatory responses. After task parameters were altered so that the time allowed for responding was reduced and anticipatory (impulsive) responses were punished by a time-out, the pattern of performance deficits changed; there were increased omission errors in α7(−/−) mice but normal levels of accuracy and anticipatory responding. Nicotine did not improve any measure of performance, either with the original training parameters or after retraining; the largest dose used (1.0 mg/kg) produced a general impairment of responding in α7(−/−) and wild-type mice. CONCLUSIONS: α7 nicotinic receptor knockout mice are impaired in performance of the 5-CSRTT, suggesting a possible role for α7 receptors in attentional processing. However, identification of a protocol for assessing attention-enhancing effects of nicotine in mice may require further modifications of test procedures or the use of different strains of animal

    Students’ satisfaction and teaching efficiency of university offer

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    This study analyses the factors affecting students’ satisfaction with university experience, focusing on the aspects characterising the teaching efficiency of educational offer. For this purpose, organisation of teaching activities, available information, teaching materials, and other facilities offered to students to make their learning experience more successful, are considered as indicators of teaching efficiency. Our interest in this topic is justified by the importance that students’ satisfaction assumes, not only as indicator of the quality of educational services but also for its relationship with overall life satisfaction and subjective well-being. A structural equation model with latent variables is estimated by using survey and administrative data of the University of Pisa. Main findings seem to show that teaching efficiency has a positive effect on satisfaction and suggest that whenever it is inadequate, or at least, considered as such, students are less satisfied for their university experience. The effects of other factors on students’ satisfaction such as studies organisation, social capital and internship experience are also discussed
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