Subject Acquisition for Web-Based Surveys

This article provides a basic report about subject recruitment processes for Web-based surveys. Using data from our ongoing Internet Survey of American Opinion project, two different recruitment techniques (banner advertisement and subscription campaigns) are compared. This comparison, together with a typology of Web-based surveys, provides insight into the validity and generalizability of Internet survey data. The results from this analysis show that, although Internet survey respondents differ demographically from the American population, the relationships among variables are similar across recruitment methods and match those implied by substantive theory. Thus, our research documents the basic methodology of subject acquisition for Web-based surveys, which, as we argue in our conclusion, may soon become the survey interview mode of choice for social scientists

Effect of Absent Tactile Sensation on Multi-digit Coordination Underlying Hand Control

We investigated the effect of anesthesia, causing absent tactile sensation feedback, on multi-digit coordination underlying hand control. The purpose of the study is to expand our understanding on the essential role of tactile sensation feedback in the sensorimotor integration process by examining the motor coordination patterns during multi-digit forces production tasks. We hypothesized that absent tactile sensation feedback would interrupt the force sharing pattern at local and non-local digits. Twelve participants were utilized for data collection and statistical analysis (25.6 ± 4.1 years old, 6 males and 6 females), right-handed (according to their preferred hand use for writing and eating) and had no significant hand injury within the last five years. All participants performed a maximal voluntary contraction (MVC), ramp, and step task, pre- and post-anesthesia. In general, participants presented lower maximal force production in all MVC conditions after anesthesia, total MVC force was not distributed evenly among individual digits, and when sensory function of the MVC involved digits are uniformly absent or intact, force sharing pattern across the individual digits would be maintained. When the instructed finger (master finger) was index, other fingers (enslaved fingers) barely produced force. However, other enslaved fingers showed relatively higher forces when the master finger was ring or little finger. When required force level increased, performance error was increased accordingly. The findings from the current study confirmed our hypothesis that absent tactile sensation feedback (somatosensory feedback) will not only affect force production at local digits, but also at non-local digits as well

Evaluation of Social Impact of Traffic Noice in Amman, Jordan

Few road traffic studies were conducted in Jordan, but the issue is drawing an increasing attention due to its growing magnitude and various impacts as a result of the high increase in vehicular traffic. This study further investigates the issue with the aim of providing an understanding of its social impact on residents of Amman, the capital of Jordan. Traffic noise levels were measured at selected locations along urban arterials and a social survey was performed to examine the reactions and attitudes of the neighboring residents towards these levels of traffic noise. The survey included social characteristics of individuals, and their attitudes towards traffic noise, and how it impacted their daily activities. A predesigned questionnaire was used for this purpose which included questions to evaluate the awareness of respondents of the problem and its environmental and health impacts. The financial impact that residents perceive of noise and the need for attenuation measures were also addressed. The results of the study also revealed that the impact of traffic noise on people can cause annoyance while performing daily activities were 24% of respondents reported that they get annoyed by traffic while working, 49% while resting, 34% while talking to others, 31% while talking on the phone, 39% while reading, 38% while watching TV and 53% of respondents get annoyed while sleeping. The respondents have also pointed out the following effects of noise: twist in mood (53%), headache (36%), and difficulty in concentration (40%). About 57% of respondents think traffic noise reduces the value of their properties and a total of 31% are willing to sell their house at reduced cost. About 59% of respondents consider attenuation measures necessary, and in order to reduce the noise, about 54% of respondents were willing to pay for attenuation measures which reflects the public awareness of the issue magnitude

What do we measure and how do we elicit it? The case for the use of repertory grid technique in multi-party psychological contract research

The psychological contract is a multi-faceted construct and, with the rise of gig work, increasingly the contract extends beyond the conventional employer-employee relationship to encompass multi-party exchanges. Against this backdrop, the question of what should be measured when assessing the contract and how it should be elicited remains a significant issue for scholars. We argue that the potential of psychological contract theory as an explanatory lens in understanding contemporary multi-party working relationships is constrained by two key limitations inherent in conventional measurement approaches. Firstly, such approaches have favoured singular rather than multiparty perspectives, and secondly, they have broadly accorded equal weight and significance to the content dimensions unearthed, despite the fact that they may differ markedly in how they are understood by each party to the employment relationship. In order to remedy these shortcomings, we make the case for adopting repertory grid technique as a methodological framework to address measurement limitations and to more rigorously assess the content of the complex multi-party psychological contract

The ACS Virgo Cluster Survey IV: Data Reduction Procedures for Surface Brightness Fluctuation Measurements with the Advanced Camera for Surveys

The Advanced Camera for Surveys (ACS) Virgo Cluster Survey is a large program to image 100 early-type Virgo galaxies using the F475W and F850LP bandpasses of the Wide Field Channel of the ACS instrument on the Hubble Space Telescope (HST). The scientific goals of this survey include an exploration of the three-dimensional structure of the Virgo Cluster and a critical examination of the usefulness of the globular cluster luminosity function as a distance indicator. Both of these issues require accurate distances for the full sample of 100 program galaxies. In this paper, we describe our data reduction procedures and examine the feasibility of accurate distance measurements using the method of surface brightness fluctuations (SBF) applied to the ACS Virgo Cluster Survey F850LP imaging. The ACS exhibits significant geometrical distortions due to its off-axis location in the HST focal plane; correcting for these distortions by resampling the pixel values onto an undistorted frame results in pixel correlations that depend on the nature of the interpolation kernel used for the resampling. This poses a major challenge for the SBF technique, which normally assumes a flat power spectrum for the noise. We investigate a number of different interpolation kernels and show through an analysis of simulated galaxy images having realistic noise properties that it is possible, depending on the kernel, to measure SBF distances using distortion-corrected ACS images without introducing significant additional error from the resampling. We conclude by showing examples of real image power spectra from our survey.Comment: ApJS, in press, complete version of the paper at the link: http://www.physics.rutgers.edu/~pcote/acs/publications.htm

Huntingtin toxicity in yeast model depends on polyglutamine aggregation mediated by a prion-like protein Rnq1

The cause of Huntington's disease is expansion of polyglutamine (polyQ) domain in huntingtin, which makes this protein both neurotoxic and aggregation prone. Here we developed the first yeast model, which establishes a direct link between aggregation of expanded polyQ domain and its cytotoxicity. Our data indicated that deficiencies in molecular chaperones Sis1 and Hsp104 inhibited seeding of polyQ aggregates, whereas ssa1, ssa2, and ydj1–151 mutations inhibited expansion of aggregates. The latter three mutants strongly suppressed the polyQ toxicity. Spontaneous mutants with suppressed aggregation appeared with high frequency, and in all of them the toxicity was relieved. Aggregation defects in these mutants and in sis1–85 were not complemented in the cross to the hsp104 mutant, demonstrating an unusual type of inheritance. Since Hsp104 is required for prion maintenance in yeast, this suggested a role for prions in polyQ aggregation and toxicity. We screened a set of deletions of nonessential genes coding for known prions and related proteins and found that deletion of the RNQ1 gene specifically suppressed aggregation and toxicity of polyQ. Curing of the prion form of Rnq1 from wild-type cells dramatically suppressed both aggregation and toxicity of polyQ. We concluded that aggregation of polyQ is critical for its toxicity and that Rnq1 in its prion conformation plays an essential role in polyQ aggregation leading to the toxicity

HIV-1 Vpr Enhances Viral Burden by Facilitating Infection of Tissue Macrophages but Not Nondividing CD4+ T Cells

Prior experiments in explants of human lymphoid tissue have demonstrated that human immunodeficiency virus type 1 (HIV-1) productively infects diverse cellular targets including T cells and tissue macrophages. We sought to determine the specific contribution of macrophages and T cells to the overall viral burden within lymphoid tissue. To block infection of macrophages selectively while preserving infection of T cells, we used viruses deficient for viral protein R (Vpr) that exhibit profound replication defects in nondividing cells in vitro. We inoculated tonsil histocultures with matched pairs of congenic viruses that differed only by the presence of a wild-type or truncated vpr gene. Although these viruses exhibited no reduction in the infection or depletion of T cells, the ability of the Vpr-deficient R5 virus to infect tissue macrophages was severely impaired compared with matched wild-type R5 virus. Interestingly, the Vpr-deficient R5 virus also exhibited a 50% reduction in overall virus replication compared with its wild-type counterpart despite the fact that macrophages represent a small fraction of the potential targets of HIV-1 infection in these tissues. Collectively, these data highlight the importance of tissue macrophages in local viral burden and further implicate roles for CC chemokine receptor 5, macrophages, and Vpr in the life cycle and pathogenesis of HIV-1