Dual Frame (Landline and Cell RDD) Estimation in a National Survey of Latinos

Explores the implications of conducting surveys by both landline and cell phones for issues of survey bias and undercoverage of Latinos, among whom the cell phone-only population is growing. Discusses sampling and weighting methods

Costs and Benefits of Full Dual-Frame Telephone Survey Designs

Assesses the cost, sample composition, weighting, and substantive effect on survey results involved in interviewing respondents by cell phone, including those with landlines. Includes demographic profiles of cell phone-only, landline-only, and dual users

Nonresponse and Measurement Error in Mobile Phone Surveys.

Landline telephone surveys have been used for several decades to generate critical knowledge about consumer confidence, health conditions, political attitudes, and other characteristics of the American public. The coverage provided by this methodology is rapidly declining due to widespread adoption and, in many cases, substitution of mobile (cell) phones over landlines. In order to address this problem, survey researchers have begun supplementing landline surveys with samples of cell phone numbers. The error properties of cell phone surveys, particularly with respect to nonresponse and measurement, are largely unknown. Researchers have limited knowledge as to why some people answer surveys on their cell phone but others do not. It is also an open question as to whether people respond less accurately on a cell phone as compared to a landline. The potential to interview people outside the home or engaged in an activity that distracts from the task of responding could result in respondents taking more cognitive shortcuts and providing less accurate data relative to landline interviews. These dynamics could also reduce the reliability of survey estimates and, for some measures, even change the mean of the response distribution. This dissertation uses data from a unique repeated-measures experiment to address these research gaps. Nonresponse modeling indicates that the sets of factors influencing participation decisions in landline and cell phone surveys are different, though overlapping. Measurement error comparisons show that the quality of data from cell phone and landline interviews are generally comparable, with some intriguing exceptions. Finally, there is evidence that respondents may answer some survey questions differently depending on whether they are interviewed at home or away from home, presumably because of differential environmental cues. This research demonstrates that the error properties of landline and cell phone survey data tend to be similar, but there are potentially important exceptions that warrant methodologists’ attention.Ph.D.Survey MethodologyUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/75977/1/ckkenned_1.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/75977/2/ckkenned_2.pd

Influence of Message Theme on Consumer Perceptions of Lab Grown Meat

Lab grown meat is a new technology being developed as a potential alternative protein source. Although some research has been done about public perception of lab grown meat, no studies to date have observed the effects of message themes on public perception of lab grown meat. The study sought to better understand measures of uncertainty and risk and benefit perceptions after viewing a themed blog post about lab grown meat. Participants were randomly assigned one of three themed blog posts - against lab grown meat, neutral, or support lab grown meat. Perception questions were asked after viewing the blog post, and a total of 238 responses were collected. Results indicated the message theme had a statistically significant effect on risk perception, benefit perception, and intention to consume, but not on message evaluation or measures of uncertainty. Further discussion as well as suggestions for future research are included

The Mechanism behind Erosive Bursts in Porous Media

Erosion and deposition during flow through porous media can lead to large erosive bursts that manifest as jumps in permeability and pressure loss. Here we reveal that the cause of these bursts is the re-opening of clogged pores when the pressure difference between two opposite sites of the pore surpasses a certain threshold. We perform numerical simulations of flow through porous media and compare our predictions to experimental results, recovering with excellent agreement shape and power-law distribution of pressure loss jumps, and the behavior of the permeability jumps as function of particle concentration. Furthermore, we find that erosive bursts only occur for pressure gradient thresholds within the range of two critical values, independent on how the flow is driven. Our findings provide a better understanding of sudden sand production in oil wells and breakthrough in filtration.Comment: 7 pages, 8 figure

Frailty index of deficit accumulation and falls: data from the Global Longitudinal Study of Osteoporosis in Women (GLOW) Hamilton cohort

BACKGROUND: To investigate the association between frailty index (FI) of deficit accumulation and risk of falls, fractures, death and overnight hospitalizations in women aged 55 years and older. METHODS: The data were from the Global Longitudinal Study of Osteoporosis in Women (GLOW) Hamilton Cohort. In this 3-year longitudinal, observational cohort study, women (N=3,985) aged ≥ 55 years were enrolled between May 2008 and March 2009 in Hamilton, Canada. A FI including co-morbidities, activities of daily living, symptoms and signs, and healthcare utilization was constructed using 34 health deficits at baseline. Relationship between the FI and falls, fractures, death and overnight hospitalizations was examined. RESULTS: The FI was significantly associated with age, with a mean rate of deficit accumulation across baseline age of 0.004 or 0.021 (on a log scale) per year. During the third year of follow-up, 1,068 (31.89%) women reported at least one fall. Each increment of 0.01 on the FI was associated with a significantly increased risk of falls during the third year of follow-up (odds ratio [OR]: 1.02, 95% confidence interval [CI]: 1.02-1.03). The area under the curve (AUC) of the predictive model was 0.69 (95% CI: 0.67-0.71). Results of subgroup and sensitivity analyses indicated the relationship between the FI and risk of falls was robust, while bootstrap analysis judged its internal validation. The FI was significantly related to fractures (hazard ratio [HR]: 1.02, 95% CI: 1.01-1.03), death (OR: 1.05, 95% CI: 1.03-1.06) during the 3-year follow-up period and overnight hospitalizations (incidence rate ratio [IRR]: 1.02, 95% CI: 1.02-1.03) for an increase of 0.01 on the FI during the third year of follow-up. Measured by per standard deviation (SD) increment of the FI, the ORs were 1.21 and 1.40 for falls and death respectively, while the HR was 1.17 for fractures and the IRR was 1.18 for overnight hospitalizations respectively. CONCLUSION: The FI of deficit accumulation increased with chronological age significantly. The FI was associated with and predicted increased risk of falls, fractures, death and overnight hospitalizations significantly

Development of GERAS DANcing for Cognition and Exercise (DANCE) : a feasibility study

Background: Dance is a mind-body activity of purposeful rhythmic movement to music. There is growing interest in using dance as a form of cognitive and physical rehabilitation. This manuscript describes the development of GERAS DANcing for Cognition and Exercise (DANCE) and evaluates its feasibility in older adults with cognitive and mobility impairments. Methods: The progressive dance curricula were delivered for 15 weeks (1-h class; twice weekly). Participants were eligible if they were community-dwelling older adults aged 60+ with early cognitive or mobility impairment able to follow three-step commands and move independently. Feasibility outcomes included recruitment/retention, adherence, participant satisfaction, safety, and adverse events. Results: Twenty-fve older adults (mean (standard deviation [SD]) age=77.55 (6.10) years, range 68–90 years) with early cognitive (Montreal Cognitive Assessment score (SD)=21.77 (4.05)) and mobility (92% were pre-frail/frail as indicated on the Fried Frailty Phenotype) impairments were recruited from a geriatric out-patient clinic or within the community. A total of 20/25 (80%) participants completed the study. Average class attendance was 72%, and self-reported homework adherence “most-days / every day” was 89%. A stepwise progression in the dance curricula was observed with increases in motor complexity and balance demands, and 95% of participants rated the program as a “just-right” challenge. Ninety percent of participants rated GERAS DANCE as excellent, and 100% would recommend the program to a friend or family member. Over 50% of participants connected outside of class time for a self-initiated cofee club. Adverse events of falls and fractures were reported for 2 participants, which occurred at home unrelated to the dance intervention during the study period. Pre-determined thresholds for feasibility were met for all outcomes. Discussion: GERAS DANCE is a feasible and enjoyable program for older adults with early cognitive or mobility impairments. GERAS DANCE curriculum grading (duration; sequence; instructions) and motor complexity increases in agility, balance, and coordination appear appropriately tailored for this population. Future work will explore the feasibility of GERAS DANCE in new settings (i.e., virtually online, community centers, or retirement homes) and the mind-body-social benefts of dance

Challenges in Columbia River Fisheries Conservation: A Response to Duda et al.

The salmonid fisheries of the Columbia River Basin (CRB) have enormous socioeconomic, cultural, and ecological importance to numerous diverse stakeholders (eg state, federal, tribal, nonprofit), and there are a wide array of opinions and perspectives on how these fisheries should be managed. Although we appreciate Duda et al.\u27s commentary, it offers only one perspective of many in this context. The objective of our paper (Hand et al. 2018) was to provide justification for “the importance of social–ecological perspectives when communicating conservation values and goals, and the role of independent science in guiding management policy and practice for salmonids in the CRB”. However, we did not intend to strictly advocate for a single course of action, and the available space within our paper\u27s Panel 1 limited us from engaging in a thorough ecological debate