The Aggregate Effects of Decentralized Knowledge Production: Financial Bloggers and Information Asymmetries in the Stock Market

New media have markedly enhanced individuals' capacity to produce and disseminate original knowledge; however, the literature has not extensively examined the broad effects of such decentralized production processes. This study thus focuses on a unique context—the stock market—in which it is possible to test the aggregate impact of blog‐based information production. Using data on 150 top financial bloggers and stock returns from the S&P 500, this study supports the hypothesis that financial blogging activity diminishes harmful information asymmetries between key market investors. This study thus adds to the “media effects” literature, highlights the societal relevance of bloggers, and shows how economic concepts and financial market settings can be employed for powerfully testing communication theories.     

Differentiating Cueing From Reasoning in Agenda‐Setting Effects

This study differentiates two explanations of agenda‐setting effects: agenda cueing (the influence of the mere fact of news coverage) and agenda reasoning (the influence of reasons for problem importance in the content of news stories). We isolate the two using a report summarizing recent news coverage as the experimental stimulus, instead of actual news coverage, allowing independent manipulation of agenda cue exposure and agenda reason exposure. A key moderator in both processes is gatekeeping trust, or trust in the media to base coverage decisions on problem importance judgments. Specifically, pure cues (without agenda reasons) are more influential on those with higher gatekeeping trust, and among those with low gatekeeping trust, cues are more influential when backed by agenda reasons.     

A New Look at Agenda‐Setting Effects—Comparing the Predictive Power of Overall Political News Consumption and Specific News Media Consumption Across Different Media Channels and Media Types

The purpose of this study was to compare the predictive power of overall political news consumption and media‐specific news consumption, on perceived issue salience across different media channels and media types in the context of the 2006 Swedish parliamentary election. Findings suggest that overall consumption of political news is significantly more important than consumption of specific media outlets in predicting changes in issue salience. Although the study demonstrates that the Swedish news media collectively can exert considerable agenda‐setting influence over their audiences, it could, however, not find any consistent evidence of differences related to media channels or media types. The reasons for and implications of the results are discussed.     

我国科技类博物馆发展的现状分析和问题思考

根据《全民科学素质行动计划纲要（2006-2010-2020年）》和《科普基础设施发展规划（2008-2010-2015）》中的概念界定,科技类博物馆是指以面向社会公众开展科普教育为主要功能,主要展示自然科学和工程技术科学以及农业科学、医药科学等内容的博物馆。其中包括科学技术馆（科学中心）、自然博物馆、天文馆、工程技术博物馆等。近10年来,我国科技类博物馆在增量建设和内容建设方面有了较大进展,但因其涉及学科、行业门类的多样性、管理体制的多头化、运行体制的单一性和展教方式的简单化,使其在运行发展中还存在很多问题,受到诸多制约。对其现状的厘清和思考有利于我国科技类博物馆的可持续健康发展,更好地履行和发挥科普场馆的科学传播与普及功能。     

The Choice Gap: The Divergent Online News Preferences of Journalists and Consumers

This study examines 4 online news sites to compare stories that journalists display most prominently with stories consumers read most frequently. We find that journalists' chosen stories are “soft” with respect to subject matter but not story format, and that these choices diverge from consumers' choices, resulting in a choice gap. The study design makes important methodological contributions by using the story as the unit of analysis, operationalizing “soft news” in terms of subject matter as well as format, and considering the influence of journalists' and consumers' choices on each other. This article discusses the implications of the findings on such issues as the dynamics of agenda setting, the prospects for consumer‐authored content, and the watchdog function of the media.     

Risk Information Seeking and Processing Model: A Meta‐Analysis

This study relies on state‐of‐the‐art meta‐analytical techniques to assess overall effects of the Risk Information Seeking and Processing (RISP) model. The results support the utility of the RISP model in predicting risk information seeking and systematic processing. However, the model demonstrated limited explanatory power for heuristic processing. A reduced model composed of only 2 variables—current knowledge and informational subjective norms—accounted for a substantial proportion of variance in the outcome variables. This more parsimonious explanation of information seeking and systematic processing might extend the utility of the RISP model to other communication settings not related to risk. Theoretical boundaries of the RISP model and implications for future research are discussed.     

Electrical Transport and Oxygen Exchange in the Superoxides of Potassium,Rubidium, and Cesium

Conductivity, ionic transference number, and chemical diffusion coefficients are determined for KO₂, RbO₂, and CsO₂. Based on such results, a defect‐chemical model is constructed. These superoxides are found to exhibit a total conductivity in the range of 3 × 10^–7 to 5 × 10^–5 S cm^–1 at 200 °C with contributions from ionic and electronic carriers. The ionic conductivity is caused by alkali interstitials and superoxide vacancies as mobile defects, and is found to exceed the n‐type electronic conductivity. ¹⁸O isotope exchange on powder samples (monitoring the gas phase composition) shows that essentially all oxygen can be exchanged. At high pO₂ this largely occurs without breaking of the O–O bond—indicating a sufficient mobility of molecular superoxide species in the solid—and with an effective rate constant that is much higher than for other large‐bandgap mixed conducting materials such as SrTiO₃.     

Using MPEG-2 video at the Getty Museum

Today museums find themselves at a crossroad. The traditional approach of designing museum exhibits as static displays must be reconciled with the technology people face in the everyday world. We are bombarded by digital information, and media sources are increasingly geared to shorter attention spans. As a result, we expect more interactivity and technology even in leisure pursuits such as visiting an art museum. To hold the public's interest, museums must enhance the user experience, they must embrace the digital age. When the new J. Paul Getty museum in Los Angeles opened in December 1997, a new multimedia experience for visitors called ArtAccess debuted. The paper discusses the ArtAccess system which lets visitors find additional information about the museum's collections     

行进在争议地带的科技博物馆

科技博物馆是非营利的公共机构,但在市场驱动和经济衰退的压力下,科技博物馆的行为日益表现出营利冲动和趋向,逐渐在与主题公园式的娱乐业之间形成了一大片"灰色地带"。它表现在三方面:教育还是娱乐;公益还是营利;公营还是民营?     

中国的专业科技类博物馆

专业科技类博物馆,是指以根据某种生产实践或科学原理而发展成的某种专业工艺操作方法和技能,以及相应的材料、设备、工艺流程等等为内容的科技博物馆。目前,中国的专业科技类博物馆呈现出行业办馆的特点。上世纪90年代以来中国的专业科技类博物馆有了迅猛的发展。蓬勃发展的背后,专业科技类博物馆存在的问题也同样需要我们关注。     

Looking for Gender: Gender Roles and Behaviors Among Online Gamers

Several hypotheses regarding the importance of gender and relationships were tested by combining a large survey dataset with unobtrusive behavioral data from 1 year of play. Consistent with expectations, males played for achievement‐oriented reasons and were more aggressive, especially within romantic relationships where both partners played. Female players in such relationships had higher general happiness than their male counterparts. Contrary to stereotypes and current hypotheses, it was the female players who played the most. Female players were also healthier than male players or females in the general population. The findings have implications for gender theory and communication‐oriented methods in games and online research—most notably for the use of self‐reported time spent, which was systematically incorrect and different by gender.     

Anisotropy of Charge Transport in a Uniaxially Aligned and Chain‐Extended,High‐Mobility,Conjugated Polymer Semiconductor

Charge transport in the ribbon phase of poly(2,5‐bis(3‐alkylthiophen‐2‐yl)thieno[3,2‐b]thiophene) (PBTTT)—one of the most highly ordered, chain‐extended crystalline microstructures available in a conjugated polymer semiconductor—is studied. Ribbon‐phase PBTTT has previously been found not to exhibit high carrier mobilities, but it is shown here that field‐effect mobilities depend strongly on the device architecture and active interface. When devices are constructed such that the ribbon‐phase films are in contact with either a polymer gate dielectric or an SiO₂ gate dielectric modified by a hydrophobic, self‐assembled monolayer, high mobilities of up to 0.4 cm² V^?1 s^?1 can be achieved, which is comparable to those observed previously in terrace‐phase PBTTT. In uniaxially aligned, zone‐cast films of ribbon‐phase PBTTT the mobility anisotropy is measured for transport both parallel and perpendicular to the polymer chain direction. The mobility anisotropy is relatively small, with the mobility along the polymer chain direction being higher by a factor of 3–5, consistent with the grain size encountered in the two transport directions.     

Client Science: Bad News and the Fully Informed ADR Client

Professor Aaron comments that this piece, excerpted from: “Bad News and the Fully Informed Client,” the first chapter of her book, Client Science, addresses the lawyer's challenge when counseling clients where “bad” news—negative, pessimistic or unwelcome developments or analysis—must be conveyed, whether or not within an ADR process. “As a mediator of civil cases, I suspect that mediation involves a higher than average percentage of cases involving ill‐counseled clients or ‘difficult clients’ who may fairly be characterized as ‘counseling‐resistant’ despite the best efforts of skilled lawyers. When the lawyer explains ‘bad news’ about case developments or likely outcomes, he risks the client's suspicion or accusation of less than zealous advocacy. While a mediator can assist with client communication when legal circumstances are grim, counsel are obligated to ensure their clients are well informed of realistic expectations when exercising autonomy and self determination.”     

The Contingency of the Mass Media's Political Agenda Setting Power: Toward a Preliminary Theory

Recently the study of the relationship between the media and the political agenda has received growing attention of both media and political science scholars. However, these research efforts have not led to a general discussion or a real theory on the media's political agenda setting power. This article first analytically confronts the often contradictory results of the available evidence. Then, it sketches the broad outline of a preliminary theory. Political agenda setting by the media is contingent upon a number of conditions. The input variables of the model are the kind of issues covered, the specific media outlet, and the sort of coverage. Political context variables, the features of the political actors at stake, are at the heart of the model. The model proposes five sorts of output ranging from no political adoption to fast substantial adoption of media issues.     

Silicon‐Based Laser Desorption Ionization Mass Spectrometry for the Analysis of Biomolecules: A Progress Report

Matrix‐assisted laser desorption/ionization mass spectrometry (MALDI‐MS) is widely used in the biomedical field for the label‐free analysis of molecules such as drugs, lipids, peptides, proteins, and biological tissues for molecular imaging. However, organic matrices used in traditional MALDI‐MS applications introduce excessive interferences in the low m/z range. For this reason, nanostructured materials—and in particular silicon‐based LDI strategies—have become a promising alternative, since they provide a much weaker background. Herein, the recent developments in fabrication, functionalization, and practical applications of silicon‐based LDI‐MS methods are reviewed. Also the basic requirements of silicon‐based substrates for optimal LDI analysis by providing an overview of the LDI mechanisms that use silicon‐based substrates instead of organic matrices are reported. Finally, the considerable potential of silicon‐based substrates is discussed, giving suggestions for topics for future research.     

Satellite visibility in Northern Europe based on digital maps

This paper presents the calculation of satellite visibility and system availability based on digital elevation maps. New models for satellite visibility are derived for both non‐geostationary orbiting satellite constellations and geostationary satellites. Regression models for satellite visibility and average number of visible satellites based on easily available surface roughness variables are developed and tested. Cumulative distributions for the percentage of time that Iridium satellites are visible, taking terrain obstacles into account, are calculated and the relation between satellite visibility and system availability is discussed. Copyright © 2000 John Wiley & Sons, Ltd.     

A Green Polymeric Light‐Emitting Diode Material: Poly(9,9‐dioctylfluorene‐alt‐thiophene) End‐Capped with Gold Nanoparticles

Poly(9,9‐dioctylfluorene‐alt‐thiophene copolymer (PDOFT) is functionalized with thiol and end‐capped with in‐situ‐reduced gold nanoparticles (AuNPs). The molecular structure of the resulting material (PDOFT‐Au) is corroborated by ¹H and ¹³C NMR spectroscopy, and direct evidence for the binding between the PDOFT‐bis‐4‐thiol and gold nanoparticles is provided from X‐ray photoelectron spectroscopy. PDOFT‐Au is not only soluble in common organic solvents, but also has a broad range of thermal stability, up to 414 °C. The photoluminescence and electroluminescence spectra show that excitation of PDOFT is virtually unaffected by the end‐capping with gold nanoparticles. However, atomic force microscopy shows that the root‐mean‐square roughness of the PDOFT‐Au film is nearly ten times higher than that of the PDOFT film, resulting in an increased interfacial area between the film and the deposited cathode in a PDOFT‐Au device. This increased interfacial area, together with the photo‐oxidation‐suppressing and hole‐blocking characteristics of AuNPs, significantly enhances the electron injection, lowers the threshold voltage, and increases the electroluminescence (10 521 cd m^–2) and photometric efficiency (1.986 cd A^–1) of the PDOFT‐Au device by nearly an order of magnitude. These increases in electroluminescence and photometric efficiency would be much lower if AuNPs were blended into—rather than capped onto—the copolymer. The Commission International de L'Eclairage color coordinates of PDOFT‐Au (0.237,0.655) are very close to the standard green demanded by the National Television System Committee, making PDOFT‐Au an excellent candidate for a green‐light‐emitting material.     

On multi‐cell admission control in CDMA networks

We consider a multi‐cell (MC) code division multiple access (CDMA) system that supports multiple service classes, including peak rate allocated and elastic ones. Peak rate allocated sessions—when admitted into the system—transmit at a constant bit rate, while elastic sessions can be slowed down at the expense of increasing their residency time. Admitted sessions cause an instantaneous bit rate‐dependent interference in neighbour cells. In this rather general setting, we propose a method to calculate the class‐wise blocking probabilities as the functions of the estimated so‐called inter‐cell coupling factors. In the paper this coupling factor is the ratio between the uplink path gains to different Node‐B:s (that can be easily obtained in a CDMA system from pilot measurement reports), but our model could include other coupling measures as well. We find that when these coupling factors are underestimated, the system may get into false states (FSs) or false rate states (FRSs) that lead to violating the noise rise threshold. As traffic becomes increasingly elastic, the probability of FSs decreases, but the probability of FRSs increases. Based on numerical results, we make the point that as the traffic becomes more elastic, avoiding the underestimation of these coupling factors as well as exercising MC admission control plays an increasingly important role in guaranteeing proper service quality. Copyright © 2007 John Wiley & Sons, Ltd.     

Generation of bivariate Nakagami‐m fading envelopes with arbitrary not necessary identical fading parameters

In this paper, a generation procedure of two correlated Nakagami‐m random variables for arbitrary fading parameters values (not necessary identical) is described. For the generation of two correlated Nakagami‐m samples, the proposed method uses the generalized Rice distribution, which appears in the conditional distribution of two correlated Nakagami‐m variables. This procedure can be applied to simulate diversity systems such as selection combiners, equal‐gain combiners, and maximal‐ratio combiners as well as multiple‐input multiple‐output (MIMO) receiver systems, in Nakagami‐m channels. Copyright © 2006 John Wiley & Sons, Ltd.