Study Of Medium Effects Research Articles

Theoretical study of lepton events in the atmospheric neutrino experiments at SuperK

Super-Kamiokande has reported the results for the lepton events in the atmospheric neutrino experiment. These results have been presented for a 22.5kT water fiducial mass on an exposure of 1489 days, and the events are divided into sub-GeV, multi-GeV and PC events. We present a study of nuclear medium effects in the sub-GeV energy region of atmospheric neutrino events for the quasielastic scattering, incoherent and coherent pion production processes, as they give the most dominant contribution to the lepton events in this energy region. We have used the atmospheric neutrino flux given by Honda et al. These calculations have been done in the local density approximation. We take into account the effect of Pauli blocking, Fermi motion, Coulomb effect, renormalization of weak transition strengths in the nuclear medium in the case of the quasielastic reactions. The inelastic reactions leading to production of leptons along with pions is calculated in a $\Delta $- dominance model by taking into account the renormalization of $\Delta$ properties in the nuclear medium and the final state interaction effects of the outgoing pions with the residual nucleus. We present the results for the lepton events obtained in our model with and without nuclear medium effects, and compare them with the Monte Carlo predictions used in the simulation and the experimentally observed events reported by the Super-Kamiokande collaboration.

Heavy-quarks in the QGP: study of medium effects through euclidean propagators and spectral functions

The heavy-quark spectral function in a hot plasma is reconstructed from the corresponding euclidean propagator. The latter is evaluated through a path-integral simulation. A weak-coupling calculation is also performed, allowing to interpret the qualitative behavior of the spectral function in terms of quite general physical processes.

Podcasting and Politics in Singapore: An Experimental Study of Medium Effects

A ban on political podcasting during the General Elections 2006 in Singapore was justified by the Singaporean government on the grounds that the new medium had a greater power to influence voters than traditional modes of political discourse. A between-subjects controlled experiment was conducted to test whether podcasts of political speeches had a greater power to influence voters’ evaluations of political candidates and likelihood of voting for them than online text-based transcripts of the same speeches. The study also examined whether mere exposure to political speeches online, irrespective of the modality, had an effect on voters’ more general political preferences, i.e. the likelihood of support and voting for the opposition. The findings suggest that political podcasts were no more persuasive than text-based websites and that the effects on political preferences, if any, were likely due the exposure to political content online, not because of the nature of the medium. The implications of the findings are discussed. Introduction The podcasting ban during the Singapore General Elections 2006 (GE 2006) was one of the first attempts in the world aimed specifically at outlawing Web streaming of political content. The impact of this decision was significant as it prompted a strong verbal rebuttal from the opposition parties in Singapore as well as from numerous critics who viewed podcasting as a new medium of democracy. The opposition parties in Singapore came out strongly against the noting that it was an attempt to curb alternative views (Chia, Low, & Luo, 2006). Reporters Without Borders, an international press freedom watchdog, considered the ban a clear indication of Singapore “once again preventing democratic debate on the Internet” (Media watchdog slams podcast ban, 2006).

Teaching & Learning Guide for: Social Psychology and Media: Critical Consideration

Teaching & Learning Guide for: Social Psychology and Media: Critical Consideration

Slanted Newspaper Coverage of Immigration: The Importance of Economics and Geography

When compared to studies of media effects, relatively few studies of the media focus on factors that influence the behavior of media organizations. Specifically, there are few empirical studies of the attributes and incentives of news organizations that might lead to slanted coverage of particular policy issues. In this study, we identify factors that lead to negatively slanted coverage of a specific policy issue: immigration. Using content analysis, geographic information systems (GIS) data, and contextual data, we find that newspaper ownership and proximity to the U.S.–Mexico border are related to slant in news articles and opinion pieces regarding immigration.

Children, Media, and Methodology

Media effect studies on children have focused on time spent with media relative to some outcome. We argue that researchers should examine quantity as the sole measure of media input only when it is of theoretical significance. In most circumstances media content and form are more important than time spent. A media diet metaphor is proposed as an alternative approach that includes both amount of exposure and program content across media platforms. Quantity is relevant primarily for hypotheses that concern time displacement (such as TV viewing displacing physical exercise) or other medium-general effects. In addition, technological advances have not yet been exploited that can allow new methodologies for studying media use and impact. As examples, eye tracking and magnetic resonance imaging are discussed to illustrate how new approaches can provide researchers with opportunities to ask different questions and to provide new perspectives on old questions.

The Immensely Inflated News Audience: Assessing Bias in Self-Reported News Exposure

Many studies of media effects use self-reported news expo- sure as their key independent variable without establishing its validity. Motivated by anecdotal evidence that people's reports of their own me- dia use can differ considerably from independent assessments, this study examines systematically the accuracy of survey-based self-reports of news exposure. I compare survey estimates to Nielsen estimates, which do not rely on self-reports. Results show severe overreporting of news exposure. Survey estimates of network news exposure follow trends in Nielsen ratings relatively well, but exaggerate exposure by a factor of 3 on average and as much as eightfold for some demographics. It follows that apparent media effects may arise not because of differences in ex- posure, but because of unknown differences in the accuracy of reporting exposure.

Toward Improving the Validity and Reliability of Media Information Processing Measures in Surveys

Measuring media information processing strategies is of great value to the study of media effects in the field. However, researchers have raised concerns about the reliability and construct validity of previously used scales. Therefore, the aim of the present study is to make a methodological contribution by developing a standardized scale for measuring heuristic and systematic information processing. Based on existing research, we tested our measures of media information processing in three independent surveys. Results demonstrate the psychometric properties of the scale and its construct validity with respect to related constructs.

Chlorination of ammonia and aliphatic amines by Cl2: DFT study of medium and substituent effects

AbstractThe mechanism of chlorination of ammonia and aliphatic amines by Cl2 was studied by quantum‐chemical calculations using a series of DFT functionals. Three different reaction pathways were considered for the reaction between Cl2 and NH3 in the gas phase. Several intermediates and transition state structures, not described earlier, were located on the corresponding potential energy surface. It is calculated that the reaction field effects (SCIPCM) on the chlorination is much less pronounced than the effect of a specific solvent interaction which was modeled by an explicit water molecule. It is also found that the calculated energy barrier and the reaction free energy of the chlorination of different amines are dependent on the alkyl‐substituent effects. With increase in the basicity of amine, the chlorination reaction becomes more feasible. Calculated geometries of intermediates and overall reaction energetics are significantly influenced by the method for a treatment of electron correlation (DFT vs. MP2), and by the fraction of HF exchange (χ) in DFT functionals. With increase in the χ in the corresponding functional, the DFT results approach those obtained at the MP2 level, and are closer to experimental values, as well. Copyright © 2008 John Wiley & Sons, Ltd.

A theoretical study of medium effects on the structure of the glycine analogue aminomethylphosphonic acid

alpha-Aminophosphonic acids are analogues of natural alpha-aminoacids and very promising agents for use in various pharmaceutical applications. However, in contrast to the numerous theoretical investigations on the structure of natural alpha-aminoacids, only very few studies on alpha-aminophosphonic acids have been performed. In the present work, we report a detailed investigation of the simplest compound, the glycine analogue aminomethylphosphonic acid (AMPA), by means of quantum mechanical calculations at the B3LYP/6-311++G(3df,2p)//B3LYP/6-31+G(d,p) and MP2/6-311++G(3df,2p)//B3LYP/6-31+G(d,p) levels. We focus on the structure of the neutral species looking at the evolution of non-ionized and ionized forms from gas phase to non-polar solvents and aqueous media. Continuum and discrete-continuum solvent models have been employed to account for the effects of the environment. The discussion is centered on: (1) the geometry and relative stability of possible conformers in gas phase and aqueous solution, (2) the free energy of tautomerization in different media, (3) the role of hydrogen bonds in liquid water, and (4) the free energy of transfer from water to a hydrophobic solvent such as cyclohexane. Systematic comparison between AMPA and Gly is performed. Though both systems exhibit many similarities, some important differences have also been found that may be explained, at least in part, by the higher acidity of phosphonic acids compared to carboxylic acids. In particular, in solvents lacking hydrogen-bond formation capability, Gly derivatives should mainly exist as non-ionized molecules while the equivalent AMPA derivatives should adopt a zwitterionic structure in media with dielectric constant above 10. This might have significant environmental or biological consequences that will need to be addressed.

DMB폰과 PMP의 작은 화면 사이즈 특성이 영상콘텐츠에 대한 정보처리과정에 미치는 영향

The recent developments of audio/video technology in the ubiquitous media have resulted in a variety of formal feature such as screen sizes for media and the new viewing environment can alter television viewers` experience of mediated communication. So the concern about formal feature of media itself is increasing in the recent media effects studies. From this point of view, this study is conducted to test the effect of the different monitor size of DMB Phone(2`1), PMP(4`3) and PC monitor(19`) on the viewers` memory and emotion of content by experimental research. The results showed that the effect by monitor size on the view`s memory and emotion is significant. And watching moving image on a bigger monitor resulted in better memory of visual message elements contained in the content and more favorable emotion of the content.

Comprehensive Interpretation of Thermal Dileptons Measured at the CERN Super Proton Synchrotron

Employing thermal dilepton rates based on a medium-modified electromagnetic correlation function we show that recent dimuon spectra of the NA60 Collaboration in central In-In collisions at the CERN-SPS can be understood in terms of radiation from a hot and dense hadronic medium. Earlier calculated in-medium rho-meson spectral functions provide an accurate description of the data up to dimuon invariant masses of about M approximately or equal to 0.9 GeV, with good sensitivity to the predicted rho-meson line shape, identifying baryon-induced modifications as the prevalent ones. A reliable evaluation of the contribution enables the study of further medium effects: at masses M>0.9 GeV, 4-pion type annihilation accounts for the experimentally observed excess (possibly augmented by effects of "chiral mixing"), while predictions for thermal emission from in-medium omega and phi mesons may be tested in the future.

Does Playing Violent Video Games Induce Aggression? Empirical Evidence of a Functional Magnetic Resonance Imaging Study

This study aims to advance the media effects debate concerning violent video games. Meta-analytic reviews reveal a small but noticeable association between playing violent video games and aggressive reactions. However, evidence for causal associations is still rare. In a novel, event-related functional magnetic resonance imaging study, 13 male research participants were observed playing a latest-generation violent video game. Each participant's game play was recorded and content analyzed on a frame-by-frame basis. Onscreen activities were coded as either "passive/dead, no interactions"; "active/safe, no imminent danger/no violent interactions"; "active/potential danger occurs, violent interactions expected"; "active/under attack, some violent interactions"; and "active/fighting and killing, many violent interactions." Previous studies in neuroscience on aggressive thoughts and behaviors suggested that virtual violence would suppress affective areas of the anterior cingulate cortex (ACC) and the amygdala subsequent to activity variations at cognitive areas of the ACC. Comparison of game play activities with and without virtual violence in 11 participants confirmed the hypothesis. The rather large observed effects can be considered as caused by the virtual violence. We discuss the applicability of neuroscience methodology in media effects studies, with a special emphasis on the assumption of virtuality prevalent in video game play.

Media Effects and the Active Elite Audience

This article explores the impact of communications on investor behaviour and trading patterns in the London Stock Exchange (LSE). The significance of the work is two-fold. First, for many observers, the wild trading patterns that regularly occur in stock markets suggest the presence of ‘strong’ media effects in action; a finding in conflict with mainstream audience research. Second, the audience investigated is an elite one that most ‘actively’ consumes its media and is rarely observed in studies of media effects. The research thus attempts to identify in what ways the media are implicated in stock market movements and, at the same time, how exactly this active, elite audience makes use of its media. The empirical material presented here is primarily that gained from interviews with elite fund managers at the London Stock Exchange, Europe’s largest financial centre.

A Panel Study of Media Effects on Political and Social Trust after September 11, 2001

The authors examine the relationship between media consumption and political trust, social trust, and confidence in governmental institutions in the year following the terrorist attacks of September 11, 2001. This period provides a unique opportunity to explore the effects of media use on trust, given that political and social trust surged in the immediate aftermath only to decline in the months that followed. Using data from a panel survey, the authors find that television news use was associated with higher levels of trust in government and confidence in institutions during the surge that followed the terrorist attacks. Individual-level change in trust and confidence over the year that followed was not, however, attributable to media use or changes in media use. In the case of social trust, the results suggest that television news and newspaper use were not associated with social trust in the immediate aftermath but were associated with individual-level change in social trust over the course of the following year. Specifically, those who watched television news exhibited declines in social trust and those who read newspapers exhibited increased social trust between fall 2001 and late summer 2002. The authors conclude by discussing how coverage in fall 2001 and changes in coverage over the following year may help to explain these results.

A quark model framework for the study of nuclear medium effects

A quark-model framework for studying nuclear medium effects on nucleon resonances is described and applied here to pion photoproduction on the deuteron which is the simplest composite nucleon system and serves as a first test case. Pion photoproduction on nuclei is discussed within a chiral constituent quark model in which the quark degrees of freedom are explicitly introduced through an effective chiral Lagrangian for the quark–pseudoscalar meson coupling. The advantage of this model is that a complete set of nucleon resonances can be systematically included with a limited number of parameters. Also, the systematic description of the nucleon and its resonances at quark level allows us to self-consistently relate the nuclear medium's influence on the baryon properties to the intrinsic dynamic aspects of the baryons. As the simplest composite nucleus, the deuteron represents the first application of this effective theory for meson photoproduction on light nuclei. The influence of the medium on the transition operators for a free nucleon is investigated in the delta resonance region. No evidence is found for a change of the delta properties in the pion photoproduction reaction on the deuteron since the nuclear medium here involves just one other nucleon and the low binding energy implies low nuclear density. However, we show that the reaction mechanism is in principle sensitive to changes of delta properties that would be produced by the denser nuclear medium of heavier nuclei through the modification of the quark-model parameters.

Quetiapine for schizophrenia.

Quetiapine is an atypical antipsychotic with, theoretically, a low propensity for movement disorder adverse effects. It is used for the treatment of schizophrenia and other psychoses.To determine the effects of quetiapine for schizophrenia in comparison to placebo, and other antipsychotics.Electronic searches of the Cochrane Schizophrenia Group's Register of Trials (February 2003), Biological Abstracts (1982-2000), CINAHL (1982-2000), the Cochrane Library (2000, Issue 1),EMBASE (1980-2000), MEDLINE (1966-2000), PsycLIT (1974-2000), SIGLE on CD (1980-1997), SocioFile (1974-1997) and many conference proceedings and hand searches of specific journals were undertaken. We contacted AstraZeneca Pharmaceuticals for information regarding unpublished trials. The review was updated in February 2003.All randomised controlled trials where adults with schizophrenia or similar illnesses were assigned to quetiapine, placebo or other neuroleptic drugs and where clinically relevant outcomes were reported.Citations and, where possible, abstracts were inspected independently by reviewers, papers ordered, re-inspected and quality assessed. We independently extracted data. We analysed data using fixed effects relative risk (RR) and estimated the 95% confidence interval (CI). Only homogeneous data were interpreted as favouring treatment or control. Where possible we calculated the number needed to treat (NNT) or number needed to harm statistics (NNH). We calculated relative risk (RR) for dichotomous data, and weighted mean differences (WMD) for continuous data.Despite the fact that 3443 people were randomised in 12 quetiapine studies, there are almost no data on service utilisation, economic outcomes, social functioning and quality of life. Over half of those within the quetiapine versus placebo comparison were lost to follow up (53% quetiapine vs 61% placebo, n=716, 4RCTs, RR 0.84 CI 0.7 to 0.9, NNT 11 CI 7 to 55) so it is impossible to interpret any ratings of global or mental state within this comparison with confidence. People allocated quetiapine, however, did not have more movement disorders than those given placebo (n=395, 2 RCTs, RR needing medication for EPSE 0.62 CI 0.3 to 1.2). The same applies to the comparison of >/= 250 mg/day quetiapine with < 250 mg/day quetiapine (49% dropout >/= 250 mg/day vs 58% < 250 mg/day, n=1066, 3 RCTs, RR 0.84 CI 0.8 to 0.9, NNT 11 CI 7 to 29). It should be noted that two deaths occurred in the higher dose group (n=618, 1 RCT, RR 0.1 CI 0.0 to 2.1). When quetiapine was compared with typical antipsychotics, about 36% of both groups failed to complete the short-term studies (n=1624, 6 RCTs, RR 0.87 CI 0.8 to 1.0). Average change in global state was heterogeneous and equivocal (n=762, 3 RCTs, WMD in short term 0.19 CI 0.00 to 0.38, I squared 76%). Mental state measures were also equivocal (n=1247, RR not improved 0.97 CI 0.9 to 1.1) including specific measures of negative symptoms (n=305, 1 RCT, MD change in SANS short term 0.94 CI -0.2 to 2.0). Movement disorders were less prevalent for those allocated quetiapine (n=1117, 4 RCTs, RR needing medication for extrapyramidal adverse effects 0.47 CI 0.4 to 0.6, NNT 4 CI 4 to 5, I squared 88%). Dry mouth (n=649, 2 RCTs, RR short term 2.85 CI 1.5 to 5.6, NNH 17 CI 7 to 65) and sleepiness (n=959, 3 RCTs, RR 1.51 CI 1.1 to 2.2, NNH 18 CI 8 to 181) may also be more prevalent for people given quetiapine compared with the older drugs. In the quetiapine versus risperidone comparison, over 30% of people left the study before completion (n=728, 1 RCT, RR 0.94 CI 0.7 to 1.2). Four people, all treated with quetiapine, died during the study (n=728, 1 RCT, RR 2.86 CI 0.2 to 52.8). Continuous mental state measures did not show clear differences between the two drugs (n=637, 1 RCT, MD PANSS 1.2 CI -2.0 to 4.4). However, considerably fewer people given quetiapine needed medication for extrapyramidal side effects compared with those allocated to risperidone (n=712, 1 RCT, RR 0.27 CI 0.2 to 0.5, NNT 11 CI 10 to 16). Quetiapine caused more dizziness (n=728, 1 RCT, RR 1.85 CI 1.0 to 3.3, NNH 18 CI 7 to 487), more dry mouth (n=728, 1 RCT, RR 2.11 CI 1.2 to 3.8, NNH 14 CI 6 to 82) and more sleepiness than risperidone (n=728, 1 RCT, RR 2.03 CI 1.4 to 2.9, NNH 7 CI 4 to 17).Quetiapine is effective for the treatment of schizophrenia, but it is not much different from first-generation antipsychotics and risperidone with respect to treatment withdrawal and efficacy. In comparison to first-generation antipsychotics and risperidone, quetiapine has a lower risk of movement disorders but higher risks of dizziness, dry mouth and sleepiness. More clearly reported pragmatic randomised controlled trials should be carried out to determine its position in everyday clinical practice. Studies of medium and long-term effects, including cost-effectiveness, quality of life, social functioning and service utilisation, in comparison with the effects of typical and atypical antipsychotics should be priority areas.

The impact of framing on perception of foreign countries

This article's overall purpose is to present a new approach to framing research that incorporates both the traditionally quantitative study of media effects and the more qualitative investigation of power relationships to uncover links between the role of dominant discourses in affecting media texts, the role of media texts in crystallising some discourses into frames (taken as common sense) and the final effect on readers’ broad perceptions of international affairs. This study examines how the framing of countries as either democratic or non-democratic by American newspapers affects readers’ perceptions, or images, of foreign countries.

Resonances at RHIC

In this report, we discuss the measurement of the hadronic decay modes of resonances in relativistic heavy-ion collisions, emphasizing on RHIC results. The study of resonances can provide: (1) the yield and spectra of more particles with different properties to study whether the system is in thermal equilibrium; (2) an independent probe of the time evolution of the source from chemical to kinetic freeze-out and detailed information on hadronic interaction at later stage; (3) the study of medium effects at a late stage of the collisions; (4) a measurement of flavour and baryon/meson dependence of particle production at intermediate pT (>2 GeV/c).

Identified charged particle results from Au + Au collisions at GeV by the PHENIX experiment at RHIC

Recent results obtained by the PHENIX experiment from the collisions of Au+Au at RHIC are presented. The characteristics of inclusive hadron production and freeze out are analysed to provide details of the collision dynamics at early and late stages. PHENIX has also measured the ϕ(1020) meson via the K+K− with excellent pair mass resolution, which should enable studies of possible medium effects on the constituent quarks.