Distinctive Encoding Reduces the Jacoby-Whitehouse Illusion

We investigated the influence of distinctive encoding on the Jacoby and Whitehouse (1989) illusion. Subjects studied visually presented words that were associated with either an auditory presentation of the same word (non-distinctive encoding) or a picture of the object (distinctive encoding). In both conditions, words were visually presented on the recognition test, and half were preceded by brief repetition primes. Priming test items increased hits and false alarms in the auditory condition, demonstrating the Jacoby-Whitehouse illusion. This illusion was reduced in the picture condition. In order to test whether this distinctiveness effect was caused by a recollection-based response strategy (i.e., the distinctiveness heuristic), we minimized recollection-based responding by having subjects make speeded recognition decisions. Contrary to the distinctiveness heuristic hypothesis, speeded responding did not eliminate the distinctiveness effect on the Jacoby-Whitehouse illusion. Picture encoding may reduce this illusion via a shift in preretrieval orientation, as opposed to a postretrieval editing process.Psycholog

Improving Highway Work Zone Safety

Highway work zones disrupt normal traffic flow and can create severe safety problems. Due to the rising needs in highway maintenance and construction in the United States, the number of work zones is increasing nationwide. With a total of 1,010 fatalities and more than 40,000 injuries occurring in 2006, improvements in work zone safety are necessary. The three primary objectives of this research project included: 1) to determine the effectiveness of a Portable Changeable Message Sign (PCMS) in reducing vehicle speeds on two-lane, rural highway work zones; 2) to determine the effectiveness of a Temporary Traffic Sign (TTS), (W20-1, “Road Work Ahead”); and 3) to determine motorists’ responses to the signage. To accomplish these objectives, field experiments were conducted at US-36 and US-73 in Seneca and Hiawatha, Kansas, respectively. During the field experiments, an evaluation of the effectiveness of the PCMS was conducted under three different conditions: 1) PCMS on; 2) PCMS off, but still visible; and 3) PCMS removed from the road and out of sight. The researchers also divided the vehicles into three classes (passenger car, truck, and semitrailer) and compared the mean speed change of these classes based on three different sign setups: PCMS on, PCMS off, and the use of the TTS (W20-1, “Road Work Ahead”). A survey was also conducted at the experimental work zones to obtain a general understanding of the motorists’ attitudes as they traveled through the construction areas. Based on the data analysis results, researchers concluded that the presence of the PCMS effectively reduced vehicle speeds on two-lane highway work zones. A slow speed is more likely to reduce the probability of a crash or the severity of a crash. In addition, researchers performed a univariate analysis of the variance test to determine if a significant interaction existed between motorists’ responses and the sign conditions. The results showed a significant interaction between the signs and passenger car vehicles

Why blog? (then and now): Exploring the motivations for blogging by popular American political bloggers

Abstract Despite the impact that influential American political bloggers have had on public policies and the mainstream media agenda in recent years, very little research is currently available on the most widely read political bloggers. Through a survey of 66 top American political bloggers, the present study examines this elite group by analyzing their initial and current motivations for blogging as well as their online and offline behaviors. The findings demonstrate that nearly all motivations for blogging have increased over time, with the most substantial increases occurring in extrinsic motivations. The results also reveal a significant association between extrinsic motivations and blogger online and offline political participation. This study demonstrates that future research on political blogs needs to look beyond blog readers and blog content and investigate the influential political bloggers themselves. Keywords bloggers, extrinsic and intrinsic motivations, political blogs, political participation In the past several years, political bloggers have played a significant role in the development of the American mainstream news agenda and Washington politics. For example, By now, many of the country's most influential bloggers have been blogging about political topics and current events for years. Some of them have been concentrating on political issues from the very beginning, such as Markos Moulitsas, who made it clear on his first Daily Kos post, 'I am liberal. I make no apologies Yet despite the intriguing emergence of bloggers into legitimate political circles and their apparent influence on American media and public policies, very little research on the most widely read political bloggers is currently available. While there is a growing body of research focused on political blog content Political Blogs and Their Bloggers Although blogs have received a considerable amount of attention recently, there is no clear consensus among scholars, media professionals and blog users about the definition of the word 'blog' 3 found that when blog readers describe blogs, they emphasize the interactional attributes rather than any structural features. These authors argue that it is 'more useful and informative to consider blogs not in terms of academic definitions, but rather in the terms of those involved in the activity of blogging The presence and popularity of blogs, which have been around since the early days of the world wide web, grew exponentially after the 11 September 2001 terrorist attacks as writers sought new outlets to express their feelings about the uncertain times and readers searched for information unavailable in the mainstream media (Blood, 2002; Unlike traditional news, most political bloggers do not subscribe to journalistic norms of objectivity; rather, their writings tend to be grounded in strong ideological assumptions Political Blogger Motivations and Behaviors The content of a blog depends heavily on the intentions of its author or authors, with some blogs serving as news aggregators, some as more personal diaries and others as political soapboxes. As boyd (2006: 3) points out in arguing that blogs should be reconceptualized as a medium rather than a genre, blogging encapsulates a 'diverse set of practices that result in the production of diverse content'. Therefore, understanding why political bloggers choose to blog is useful for expanding our understanding of the content found on those blogs. Indeed, while laying out a framework for studying mainstream media effects, Scheufele (1999) argues for the importance of analyzing why journalists adopt certain frames rather than limiting our focus to frames themselves. Similarly, Carragee and Roefs Cognitive psychologists assert that an individual's behavior is influenced by both intrinsic and extrinsic motivations Several recent studies have begun to examine the question of why bloggers blog. While these studies focused on bloggers generally, it is important to distinguish between those who blog about personal, social and cultural topics and those who concentrate on political issues, as their motivations may differ. In his study of non-'A-list' political bloggers, Wallsten (2005) found these bloggers were primarily driven by two motivations: (1) a desire for self-expression on political issues (i.e. a form of political expression) and (2) a desire to influence the distribution of social goods and social values (i.e. a form of political participation). According to this categorization, political bloggers are driven by both intrinsic and extrinsic motivations, the former being intrinsic and the latter extrinsic as bloggers are rewarded by perceiving the influence of their content beyond themselves. Therefore, the present study provides an investigation into the motivations for political blogging, whether these motivations change over time and if these motivations impact blogger behavior. Following the work of H1: Extrinsic motivations for blogging will increase over the blogspan. RQ1: Will intrinsic motivations for blogging change over the blogspan? Extending the work of Sampling the Most Widely Read Political Blogs To determine the top blogs, indexing sites employ a number of different methods Measures In the survey, we developed 13 possible blogger motivations based on the previous research (Blood, 2002; Beyond questions concerning motivations, the survey also measured bloggers' online and offline political behavior. In terms of bloggers' offline political behavior, we adopted political participation items widely used in political communication research new media & society XX(X) paper petition, contributed money to a political campaign or cause, worked on a political campaign, contacted elected officials, wrote a letter to the editor of a newspaper or magazine, volunteered for a social group or cause and attended a protest or rally (M = 4.83, SD = 2.40, α = .86). Their response was recorded on an 11-point scale that ranged from 0 (not at all) to 10 (very frequently). Blogger online behaviors are broadly defined by two behavioral orientations of blogging: social interaction and information search In addition to these quantitative measures, bloggers were also asked the open-ended question, 'Why did you start a blog?' Responses to this question will appear later to provide further contextual information about this study's findings concerning motivations for blogging. Participants were also asked several other questions about party identification, media use and blog content that are beyond the scope of the current study. Results In response to our survey, participants rated the following three items highest for initial blogger motivations: 'to let off steam' (M = 7.00, SD = 2.93), 'to keep track of your thoughts' (M = 6.46, SD = 3.20) and 'to formulate new ideas' (M = 6.44, SD = 3.09). The three lowest initial motivators were 'to influence mainstream media' (M = 3.83, SD = 3.34), 'to help your political party or cause' (M = 4.58, SD = 3.69) and 'to serve as a political watchdog' (M = 4.79, SD = 3.40). As for current motivations for blogging, the three items that most strongly resonated with our respondents were 'to provide an alternative perspective to the mainstream media' (M = 7.87, SD = 2.43), 'to inform people about the most relevant information on topics of interest' (M = 7.61, SD = 2.31) and 'to influence public opinion' (M = 7.27, SD = 2.69). While none of these statements were considered among the top three initial motivations, the three weakest current motivators were very similar to the three lowest initial motivators: 'to influence mainstream media' (M = 5.25, SD = 3.06), 'to critique your political opponents' (M = 5.64, SD = 3.14) and 'to help your political party or cause' (M = 5.81, SD = 3.24). at SAGE Publications on March 20, 2015 nms.sagepub.com Downloaded from Ekdale et al. 9 To test the differences between initial and current levels of motivations for blogging among respondents, we conducted a paired-sample t-test. As shown in In terms of intrinsic motivations, thought process motivations also increased over the blogspan (initial: M = 6.49, SD = 2.69; current: M = 7.04, SD = 2.29; t = 2.02, d.f. = 62, p <.05), although the increase in 'to keep track of your thoughts' is not statistically significant (t = 0.96, d.f. = 60, p > .10). Finally, the catharsis motivation, 'to let off steam', was the only motivation to decrease from initial to current levels at the .1 significance level. The current mean score of 'to let of steam' was 6.57 (SD = 2.76), whereas the initial mean score was 7.00 (SD = 2.93) (t = −1.79, d.f. = 59, p < .1). To assess the relationship between motivations and behaviors, a hierarchical regression analysis was performed. The five demographic and partisanship variables were entered in a first block, followed by a second block consisting of the three types of blogger motivations: extrinsic, articulating ideas and catharsis. The equations of this model were run to make an initial assessment of which kinds of motivations have significant effects on bloggers' political behaviors. Discussion Based on the results of our survey, all motivations for blogging increased over the course of our participants' blogspans except for the motive 'to let off steam'. This finding demonstrates that for the top political bloggers included in our survey the activity of blogging reinforced their motivations for blogging. Overall, these bloggers were more motivated to blog now than when they first started blogging. In particular, the motivation 'to at SAGE Publications on March 20, 2015 nms.sagepub.com Downloaded from 10 new media & society XX (X) provide an alternative perspective to the mainstream media' exhibited the largest increase over time. This demonstrates that relative to when these bloggers first decided to provide their unique point-of-view online, they now saw an increased need to offer their perspective. They became more cognizant of the fact that, outside of traditional news media and day-to-day interactions, the blogosphere provided them with an outlet for disseminating information and expressing political opinions. Indeed, several of the responses to our open-ended motivation question indicate that many bloggers found blogging to be an effective outlet for providing alternative perspectives on political and social issues: I was skeptical of them at first -mostly saw them as vanity projects. Then I saw that they were capable of moving information around the traditional media bottlenecks and decided that it was something I could contribute to. (#33) First, I was frustrated out of my wits with the shallowness, and lack of context, background, and even facts, in political reporting. I started blogging so I could research and provide (for SOMEBODY) the information and context I wasn't seeing in establishment media. (#11

Properties of cosmologies with dynamical pseudo Nambu-Goldstone bosons

We study observational constraints on cosmological models with a quintessence field in the form of a dynamical pseudo Nambu-Goldstone boson. After reviewing the properties of the solutions, from a dynamical systems phase space analysis, we consider the constraints on parameter values imposed by luminosity distances from the 60 Type Ia supernovae published by Perlmutter et al., and also from gravitational lensing statistics of distant quasars. In the case of the Type Ia supernovae we explicitly allow for the possibility of evolution of the peak luminosities of the supernovae sources, using simple empirical models which have been recently discussed in the literature. We find weak evidence to suggest that the models with supernovae evolution fit the data better in the context of the quintessence models in question. If source evolution is a reality then the greatest challenge facing these models is the tension between current value of the expansion age, H_0 t_0, and the fraction of the critical energy density, Omega_{phi0}, corresponding to the scalar field. Nonetheless there are ranges of the free parameters which fit all available cosmological data.Comment: 22 pages, RevTeX, 13 figures, epsf. v3: References added, plus a few sentences to clarify some small points; v4: Typos fixe

Self-similar cosmological solutions with a non-minimally coupled scalar field

We present self-similar cosmological solutions for a barotropic fluid plus scalar field with Brans-Dicke-type coupling to the spacetime curvature and an arbitrary power-law potential energy. We identify all the fixed points in the autonomous phase-plane, including a scaling solution where the fluid density scales with the scalar field's kinetic and potential energy. This is related by a conformal transformation to a scaling solution for a scalar field with exponential potential minimally coupled to the spacetime curvature, but non-minimally coupled to the barotropic fluid. Radiation is automatically decoupled from the scalar field, but energy transfer between the field and non-relativistic dark matter can lead to a change to an accelerated expansion at late times in the Einstein frame. The scalar field density can mimic a cosmological constant even for steep potentials in the strong coupling limit.Comment: 10 pages, 1 figure, revtex version to appear in Phys Rev D, references adde

Charged Dilatonic AdS Black Branes in Arbitrary Dimensions

We study electromagnetically charged dilatonic black brane solutions in arbitrary dimensions with flat transverse spaces, that are asymptotically AdS. This class of solutions includes spacetimes which possess a bulk region where the metric is approximately invariant under Lifshitz scalings. Given fixed asymptotic boundary conditions, we analyze how the behavior of the bulk up to the horizon varies with the charges and derive the extremality conditions for these spacetimes.Comment: References update

Type II-P Supernovae from the SDSS-II Supernova Survey and the Standardized Candle Method

We apply the Standardized Candle Method (SCM) for Type II Plateau supernovae (SNe II-P), which relates the velocity of the ejecta of a SN to its luminosity during the plateau, to 15 SNe II-P discovered over the three season run of the Sloan Digital Sky Survey - II Supernova Survey. The redshifts of these SNe - 0.027 < z < 0.144 - cover a range hitherto sparsely sampled in the literature; in particular, our SNe II-P sample contains nearly as many SNe in the Hubble flow (z > 0.01) as all of the current literature on the SCM combined. We find that the SDSS SNe have a very small intrinsic I-band dispersion (0.22 mag), which can be attributed to selection effects. When the SCM is applied to the combined SDSS-plus-literature set of SNe II-P, the dispersion increases to 0.29 mag, larger than the scatter for either set of SNe separately. We show that the standardization cannot be further improved by eliminating SNe with positive plateau decline rates, as proposed in Poznanski et al. (2009). We thoroughly examine all potential systematic effects and conclude that for the SCM to be useful for cosmology, the methods currently used to determine the Fe II velocity at day 50 must be improved, and spectral templates able to encompass the intrinsic variations of Type II-P SNe will be needed.Comment: Accepted for publication by ApJ; data used in this paper can be downloaded from http://sdssdp47.fnal.gov/sdsssn/photometry/SNIIp.tgz; citation errors correcte

The fast declining Type Ia supernova 2003gs, and evidence for a significant dispersion in near-infrared absolute magnitudes of fast decliners at maximum light

We obtained optical photometry of SN 2003gs on 49 nights, from 2 to 494 days after T(B_max). We also obtained near-IR photometry on 21 nights. SN 2003gs was the first fast declining Type Ia SN that has been well observed since SN 1999by. While it was subluminous in optical bands compared to more slowly declining Type Ia SNe, it was not subluminous at maximum light in the near-IR bands. There appears to be a bimodal distribution in the near-IR absolute magnitudes of Type Ia SNe at maximum light. Those that peak in the near-IR after T(B_max) are subluminous in the all bands. Those that peak in the near-IR prior to T(B_max), such as SN 2003gs, have effectively the same near-IR absolute magnitudes at maximum light regardless of the decline rate Delta m_15(B). Near-IR spectral evidence suggests that opacities in the outer layers of SN 2003gs are reduced much earlier than for normal Type Ia SNe. That may allow gamma rays that power the luminosity to escape more rapidly and accelerate the decline rate. This conclusion is consistent with the photometric behavior of SN 2003gs in the IR, which indicates a faster than normal decline from approximately normal peak brightness.Comment: 41 pages, 13 figures, to be published in the December, 2009, issue of the Astronomical Journa