2,990 research outputs found
QCD Processes at the LHC
The study of QCD processes at the LHC will serve two main goals. First the
predictions of QCD will be tested and precision measurements will be performed.
Second QCD processes represent a major part of the background to other Standard
Model processes and signals of new physics at the LHC and thus need to be
understood precisely in the new kinematic region available here. Furthermore,
the production cross-sections for almost all processes are controlled by QCD.Comment: 4 pages, 4 figures in eps, talk given at XXXI International Symposium
on Multiparticle Dynamics, Sept 1-7, 2001, Datong China. URL
http://ismd31.ccnu.edu.cn
The influence of ruminative processing mode on the trajectory of intrusive memories following a negative mood induction
© 2019 Elsevier Ltd Background and objectives: Rumination following an event, particularly in an abstract as opposed to concrete processing mode, is associated with increased intrusive memory frequency. However, the temporal trajectory of intrusive memories following abstract and concrete rumination remains unclear. We examined the association between processing mode and the frequency of intrusive memories over a 6-h time period following a negative mood induction. Methods: One hundred and sixteen community participants watched a video sequence designed to induce negative mood. Participants were then randomised into condition (abstract, concrete or distraction) and completed a verbally mediated task designed to induce the respective processing mode. Participants then completed hourly ratings of rumination and intrusive memories about the video after leaving the laboratory. Results: Negative mood and intrusive memories were reliably induced. There were no differences in the frequency of intrusive memories between the abstract and concrete conditions. In contrast, participants in the distraction condition reported significantly more sensory intrusive memories than either ruminative condition. Three classes were found among participants following the video (intrusion free, rapid remitters, slow remitters). Condition was not predictive of class membership. Limitations: It cannot be ruled out that the differences between rumination and distraction conditions were due to task differences. Conclusions: In contrast to previous findings, our results suggest that any form of rumination about an event (whether in an abstract or concrete mode) may temporarily result in fewer intrusive memories in comparison to distraction. Processing mode does not appear to predict particular trajectories of intrusions following a mood induction
Root colonization and spore population by VA-mycorrhizal fungi in four grapevine rootstocks
The occurrence of vesicular arbuscular (VA) mycorrhizae was investigated in an experimental vineyard at the Thessaloniki prefecture, in a soil which was poor in available P. The soil had not received any phosphorus fertilization for several years, nevertheless the leaves had an adequate P content (0.17 - 0.31 % of d.w.). The vineyard was planted with 4 introduced (Cinsaut, Syrah, Grenache, Carignan) and 4 local cultivars (Athiri, Roditis, Assyrtiko, Malagouzia), grafted to the rootstocks 110 R, 41 B, 140 Ru and 1103 P. Microscopic examination showed that all 4 rootstocks were colonized by VA-mycorrhizal fungi at frequencies ranging from 45 to 75 %. The number of vesicles varied between 16 and 47 and the number of arbuscules between 5 and 26 per cm of infected root. Spore number produced by the mycorrhizal fungi in the rhizosphere ranged from 196 to 280 per 100 g of soil. Spores of the genus Glomus were more commonly encountered, in particular those of G. mosseae and G. macrocarpum. The roots of 1103 P, followed by 41 B, 140 Ru and 110 R were most heavily colonized. The same pattern was observed with regard to the number of spores in the rhizosphere of these rootstocks. Grafted cultivars were found to have some influence on the degree of colonization of these rootstocks and on the population of spores, but had no effect on the formation of vesicles and arbuscules. The degree of colonization of roots by endomycorrhizal fungi was inversely related to the available P content of the soil. At the time of root sampling the P content of leaves was not directly related neither to the degree of root colonization nor to the P content of the soil. However, leaves were found to be adequately supplied with P in all cases. Therefore, the differences observed among the 8 cultivars can be attributed primarily to a variety-specific demand for P
A multilevel longitudinal study of experiencing virtual presence in adolescence: the role of anxiety and openness to experience in the classroom
Presence describes the feeling of reality and immersion that users of virtual/internet environments have. Importantly, it has been suggested that there are individual and contextual differences regarding susceptibility to presence. These aspects of presence have been linked to both beneficial and disadvantageous uses of the internet, such as online therapeutic applications and addictive internet behaviours. In the present study, presence was studied in relation to individual anxiety symptoms and classroom-level openness to experience (OTE) using a normative sample of 648 adolescents aged between 16 and 18 years. Presence was assessed with the Presence II questionnaire, anxiety symptoms with the relevant subscales of the SCL-90-R, and OTE with the Five Factor Questionnaire. A three-level hierarchical linear model was calculated. Results showed that experiencing presence in virtual environments dropped between the ages of 16 and 18 years. Additionally, although anxiety symptoms were associated with higher presence at 16 years, this association decreased with age. Results also demonstrated that adolescents in classrooms higher on OTE reported reduced level of experiencing presence. The practical and theoretical implications of these findings are discussed
Data Sparseness and Variance in Accounting Profitability
__Abstract__
A central question in strategic management is why some firms perform better than others. One approach to addressing this question empirically is to decompose the variance in firm-level profitability into firm, industry, location, and year components. Although it is well established that data sparseness in variance decomposition studies can lead to overestimating particular variance components, little attention has been paid to sample size requirements in strategic management studies that have examined the nature of differences in firm profitability. We conduct a meta-regression and variance decomposition study and conclude that the variatio
A longitudinal study of adolescent Internet addiction: the role of conscientiousness and classroom hostility
Over the last decade, research on Internet Addiction (IA) has increased. However, almost all studies in this area are cross-sectional and do not examine the context in which internet use takes place. Therefore, a longitudinal study examined the role of conscientiousness (as a personality trait) and classroom hostility (as a contextual factor) in the development of IA. The participants comprised 648 adolescents and were assessed over a two-year period (while aged 16–18 years). A three-level hierarchical linear model was carried out on the data collected. Findings revealed that: (i) lower conscientiousness was associated with IA and this did not change over time; and (ii) although being in a more hostile classroom did not initially have a significant effect, it increased girls’ IA vulnerability over time and functioned protectively for boys. Results indicated that the contribution of individual and contextual IA factors may differ across genders and over time. More specifically, although the protective effect of conscientiousness appeared to hold, the over-time effect of classroom hostility increased the risk of IA for girls. These findings are discussed in relation to the psychological literature. The study’s limitations and implications are also discussed
Network analyses of internet gaming disorder symptoms and their links with different types of motivation
The study used regularized partial correlation network analysis (EBICglasso) to examine the structure of DSM-5 internet gaming disorder (IGD) symptoms (network 1); and the associations of the IGD symptoms in the network with different types of motivation as defined in the self-determination theory i.e., intrinsic motivation (engaging in an activity for something unrelated to the activity), identified regulation (engaging in the activity because it aligns with one’s values and/or goals), external regulation (engagement in activity being driven by external rewards and/or approval), and amotivation (engaging in an activity without often understanding why) (network 2). Participants were 968 adults from the general community. They completed self-rating questionnaires covering IGD symptoms and different types of motivation. The findings for network 1 showed mostly positive connections between the symptoms within the IGD network. The most central symptom was loss of control, followed by continuation, withdrawal symptoms, and tolerance. In general, these symptoms were more strongly connected with each other than with the rest of the IGD symptoms. The findings for network 2 showed that the different types of motivation were connected differently with the different IGD symptoms. For instance, the likeliest motivation for the preoccupation and escape symptoms is intrinsic motivation, and for negative consequences, it is low identified regulation. Overall, the findings showed a novel understanding of the structure of the IGD symptoms, and the motivations underlying them. The clinical implications of the findings for assessment and treatment of IGD are discussed
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