4,558 research outputs found

    Morrey type spaces and multiplication operator in Sobolev spaces

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    The paper deals with the operator u→guu\rightarrow gu defined in the Sobolev space Wr,p(Ω)W^{r,p}(\Omega) and which takes values in Lp(Ω)L^p(\Omega) when Ω\Omega is an unbounded open subset in RnR^n. The functions gg belong to wider spaces of LpL^p connected with the Morrey type spaces. LpL^p estimates and compactness results are stated

    Lysenko and the screwworm fly—when politics interferes with science and public health

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    In the One Health scenario, a deep understanding of the dynamics potentially threatening the development and implementation of useful pest and vector management tools is of key importance. The New World screwworm fly, Cochliomyia hominivorax (Coquerel) (Diptera: Calliphoridae), is characterized by a wide host range. It acts as an important agent of myiasis in humans and warm-blooded animals in the Neotropics, and has been eliminated from a wide region through genetic methods. Of note, Serebrovsky had already proposed in 1940 the principles of autocidal control by the translocation of segments between two chromosomes, but his work was negated by Lysenko, based on the negation of Mendelian genetics. This entomological case study emphasizes the danger of politics interfering with science, a still contemporary hot issue. The negation of global warming or current pandemics are further examples of this noxious influence

    AFM-STED correlative nanoscopy reveals a dark side in fluorescence microscopy imaging

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    It is known that the presence of fluorophores can influence the dynamics of molecular processes. Despite this, an affordable technique to control the fluorophore distribution within the sample, as well as the rise of unpredictable anomalous processes induced by the fluorophore itself, is missing. We coupled a stimulated emission depletion (STED) microscope with an atomic force microscope to investigate the formation of amyloid aggregates. In particular, we studied the in vitro aggregation of insulin and two alloforms of b amyloid peptides. We followed standard methods to induce the aggregation and to label the molecules at different dye-to-protein ratios. Only a fraction of the fibrillar aggregates was displayed in STED images, indicating that the labeled molecules did not participate indistinctly to the aggregation process. This finding demonstrates that labeled molecules follow only selected pathways of aggregation, among the multiple that are present in the aggregation reaction

    Potential for building Façade-integrated solar thermal collectors in a highly urbanized context

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    Development of technologies, materials, support systems, and coatings has made the integration of solar thermal systems into the building envelope increasingly possible. Solar thermal collectors can either be directly integrated, substituting conventional roof or façade covering materials, or constitute independent devices added to a roof or façade structure. Aimed at estimating the real effectiveness of building-integrated solar systems for domestic heat water (DHW) production or for heating integration, when horizontal or inclined pitches on buildings are not applicable, the authors analyze a case study with different scenarios, taking into account the issues connected to a highly urbanized context in the Mediterranean climate. A GIS model was used for estimating the energy balance, while the real producibility of the simulated systems was calculated by a dynamic hourly simulation model, realized according to ISO 52016. The savings in terms of primary energy needs obtained by installing solar thermal systems on the facade are presented, and the differences between the cases in which the system is used for DHW production only and for space heating too are distinguished and discussed. The evaluated potential is quantified in the absence of roof collectors, despite their high potential in the Mediterranean region, in order to better appreciate the effects induced by integrated facade systems

    Social norms and problematic gaming among adolescents: The role of Internet use coping motives.

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    Problematic gaming (PG) is a public health issue among adolescents worldwide. Although several studies have documented that peer influences constitute a relevant risk factor for adolescent problematic behaviors, little research is currently available on PG. The aim of this study was to examine the contribution of social norms and perceived friends' gaming frequency on participants' own gaming frequency and PG, by testing potential differences among groups with low vs. high motive to use the Internet (e.g., online gaming) as a coping strategy. A survey was administered to 470 adolescent gamers (mean age = 15.49 years; SD = 1.05 years; 77.9 % males). A theoretical model was tested through path analysis and multi-group comparisons were performed. Path analysis revealed that social norms and perceived friends' gaming frequency were positively associated to participants' gaming behaviors and PG. Additionally, different patterns between groups emerged. Our findings confirmed the relative importance of peer influences on adolescents' gaming behaviors and PG and showed that adolescents who rely more on online gaming to cope with negative affect may be more vulnerable to social influence processes than other peers. These findings may provide useful indications for prevention programs targeting adolescent PG. [Abstract copyright: Copyright © 2023 Elsevier Ltd. All rights reserved.

    Social anxiety and Internet gaming disorder: The role of motives and metacognitions

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    AbstractBackground and aimsIn recent years, Internet Gaming Disorder (IGD) has been recognized as a mental health problem. Although research has found that social anxiety, motives, the preference for online social interactions (POSI), and metacognitions about online gaming are independent predictors of IGD, less is known about their relative contribution to IGD. The aim of the current study was to model the relationship between social anxiety, motives, POSI, metacognitions about online gaming, and IGD.MethodsFive hundred and forty three Italian gamers who play more than 7 h a week (mean age = 23.9 years; SD = 6.15 years; 82.5% males) were included in the study. The pattern of relationships specified by the theoretical model was examined through path analysis.ResultsResults showed that social anxiety was directly associated with four motives (escape, coping, fantasy, and recreation), POSI, and positive and negative metacognitions about online gaming, and IGD. The Sobel test showed that negative metacognitions about online gaming played the strongest mediating role in the relationship between social anxiety and IGD followed by escape, POSI, and positive metacognitions. The model accounted for 54% of the variance for IGD.Discussion and conclusionsOverall, our findings show that, along with motives and POSI, metacognitions about online gaming may play an important role in the association between social anxiety and IGD. The clinical and preventive implications of these findings are discussed

    Maternal Parenting Stress and Preschoolers’ Social-Emotional Competence and Behavioural Difficulties: A Variable- and Person-Centred Approach

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    Background: The present study examined the relations between maternal parenting stress and preschoolers’ psychosocial adjustment, using both a variable-centred and a person-centred approach. Methods: The study had three main purposes: (a) evaluating the associations of maternal parenting stress with children’s social-emotional competence and behavioural difficulties, as perceived by their mothers; (b) inquiring the existence of different children’s clusters based on their level of social-emotional competence and behavioural difficulties; (c) exploring differences in maternal parenting stress linked to cluster membership. Participants were 91 Italian mothers, aged from 22 to 47 years old (M = 35.14, SD = 5.80), having a preschool child from 3 to 6 years old (M = 4.6, SD = 0.80). Results: Overall, results showed that maternal parenting stress was negatively associated with children’s social-emotional competence, and positively associated with their behavioural difficulties. A cluster analysis allowed identifying four children’s profiles characterized by different levels of social-emotional competence and behavioural difficulties: Maladjusted, Troubled, Adjusted and Controversial. Conclusions: Results also evidenced differences among clusters in maternal parenting stress. Ultimately, this study suggests that interventions may consider reducing maternal parenting stress to promote children’s psychosocial adjustment
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