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901.
The objective of this study was determine if the inclusion of Canadian-style graphic images would improve the degree to which adolescents attend to, and subsequently are able to recall, novel warning messages in tobacco magazine advertising. Specifically, our goal was to determine if the inclusion of graphic images would (1) increase visual attention, as measured by eye movement patterns and fixation density, and (2) improve memory for tobacco advertisements among a group of 12 to 14 year olds in the western United States. Data were collected from 32 middle school students using a head-mounted eye-tracking device that recorded viewing time, scan path patterns, fixation locations, and dwell time. Participants viewed a series of 20 magazine advertisements that included five U.S. tobacco ads with traditional Surgeon General warning messages and five U.S. tobacco ads that had been modified to include non-traditional messages and Canadian-style graphic images. Following eye tracking, participants completed unaided- and aided-recall exercises. Overall, the participants spent equal amounts of time viewing the advertisements regardless of the type of warning message. However, the warning messages that included the graphic images generated higher levels of visual attention directed specifically toward the message, based on average dwell time and fixation frequency, and were more likely to be accurately recalled than the traditional warning messages. 相似文献
902.
903.
Sarah E. Nelson John H. Kleschinsky Richard A. LaBrie Sara Kaplan Howard J. Shaffer 《Journal of gambling studies / co-sponsored by the National Council on Problem Gambling and Institute for the Study of Gambling and Commercial Gaming》2010,26(1):129-144
For more than a decade, casinos around the world have offered self-exclusion programs (SEPs) to gamblers seeking help with
their gambling behavior. Despite the proliferation of SEPs, little is known about the long-term outcomes for gamblers who
utilize these programs. The current study assessed the experiences of a sample (N = 113) of Missouri self-excluders (SEs) for as long as 10 years after their initial enrollment in the Missouri Voluntary
Exclusion Program (MVEP). Most SEs had positive experiences with MVEP and reduced their gambling and gambling problems after
enrollment. However, 50% of SEs who attempted to trespass at Missouri casinos after enrollment were able to, indicating that
the benefit of MVEP was attributable more to the act of enrollment than enforcement. SEs who engaged in complementary treatment
or self-help groups had more positive outcomes than those who did not, suggesting that SEPs ought to encourage and provide
information about additional support and treatment options to participants. 相似文献
904.
905.
Alfred Alumai Mark Grunkemeyer Joseph Kovach David J. Shetlar John Cardina Joseph Rimelspach Susan Clayton Parwinder S. Grewal 《Urban Ecosystems》2010,13(1):37-49
Human choices regarding land cover management practices may influence ecosystem services provided by urban green spaces. We
conducted a 2-year study to compare biological (weed, insect, and disease), aesthetic (lawn quality), and economic (lawn care
program cost) attributes of an integrated pest management (IPM) program, in which pesticides are applied on the basis of treatment
thresholds, with a standard program, in which pesticides are applied on a calendar basis without pest monitoring. Both programs
were managed by a professional lawn care operator. Although weed incidence was low, the IPM program had significantly more
lawns with weed presence than the standard program during 2005 and 2006. However, only 21% of the IPM lawns required herbicide
applications in 2005, and none exceeded the treatment threshold (5% weed cover) in 2006 as compared to 100% of the standard
program lawns being treated for weeds in both years. The IPM program also had significantly more lawns with insect damage
than the standard program during June 2005 and August 2005, but not September 2005 and throughout 2006. Only 28% of the IPM
lawns required insecticide applications in 2005 and none exceeded the threshold (5% insect damage) in 2006 whereas all of
the lawns in the standard program received insecticide treatments in both years. Rhizoctonia blight was present on some of
the lawns, but was not a common problem. Although lawn quality was high for both programs (>8, on a scale of 1–9), it was
significantly higher for standard than for IPM program lawns during 2005, and June 2006 and September 2006, but not August
2006. The annual lawn management costs were lower for the IPM (281.50) than the standard program (281.50) than the standard program (458.06). Thirty one percent
of the IPM program customers who continued with the study in 2006 did so because they were satisfied with the IPM program.
Among those who did not continue with the program, 33% cited weed or insect problems, while 33% expected better results. The
implications of these findings for implementation of IPM in professional lawn care are further discussed. 相似文献
906.
Plant-based stormwater management systems such as green roofs are typically composed exclusively of vascular plants. Yet,
mosses have several desirable properties that could warrant their more widespread use in green roof applications. In natural
systems mosses are important primary colonizers of bare ground, and their establishment improves water storage and provides
numerous soil benefits including carbon and nitrogen sequestration. Additionally, mosses often facilitate the establishment
and survival of vascular plants at otherwise environmentally harsh or stressful sites. Despite their potential value, few
studies have investigated the functional performance of mosses on green roofs. In this study we evaluated the establishment
success and potential stormwater performance of three candidate moss species. We also directly compared the runoff and thermal
characteristics of replicate moss covered green roofs to vascular planted and bare roofs. Candidate mosses had high water
holding capacities, storing 8–10 times their weight in water compared to only 1.3 times for typical green roof medium. Mock-up
roof sections composed of mosses and medium had delayed and reduced runoff flows relative to medium only sections, although
the magnitude of these effects varied with moss species. In field trials all three mosses survived a harsh rooftop environment
with limited summer irrigation, although lateral growth after one year was minimal. Green roofs planted solely with Racomitrium canescens had between 12–24% higher stormwater retention than vascular or medium only roofs. Moss cover also ameliorated temperature
fluctuations on green roofs. Hourly heating rates were buffered to a similar degree (less than half that of surface temperatures)
5 cm below the surface of both moss covered and medium only roofs. In contrast, cooling under the surface of the moss roof
was nearly 6 times faster than under the medium only roof. These results demonstrate the potential for mosses to be valuable
components of green roofs, either in combination with vascular plants or planted exclusively. 相似文献
907.
The ‘big story/small story’ distinction has emerged as a discrete approach to narrative analysis. Proponents of this approach are critical of the ‘big stories’ elicited by structural analysts, which they see as highly structured narratives of past experiences, typically elicited in an interview context. In contrast, they highlight the importance of studying the fragmented, contextualised ‘small stories’ that arise in everyday conversation/interaction. We question the basis of this distinction and we suggest that it unnecessarily proliferates analytic categories. Further, we suggest that the methodologies followed by ‘small stories’ analysts are often similar to those used to elicit ‘big stories’ and are hence open to similar criticisms; in particular, a failure to fully consider the issue of (contextual) naturalism. Drawing on interviews of crime/terrorism in Northern Ireland, we show how these data comprise both ‘big stories’ and ‘small stories’ within the same context and often within the same narrative. 相似文献
908.
Longitudinal studies suffer from patient dropout. The dropout process may be informative if there exists an association between dropout patterns and the rate of change in the response over time. Multiple patterns are plausible in that different causes of dropout might contribute to different patterns. These multiple patterns can be dichotomized into two groups: quantitative and qualitative interaction. Quantitative interaction indicates that each of the multiple sources is biasing the estimate of the rate of change in the same direction, although with differing magnitudes. Alternatively, qualitative interaction results in the multiple sources biasing the estimate of the rate of change in opposing directions. Qualitative interaction is of special concern, since it is less likely to be detected by conventional methods and can lead to highly misleading slope estimates. We explore a test for qualitative interaction based on simultaneous confidence intervals. The test accommodates the realistic situation where reasons for dropout are not fully understood, or even entirely unknown. It allows for an additional level of clustering among participating subjects. We apply these methods to a study exploring tumor growth rates in mice as well as a longitudinal study exploring rates of change in cognitive functioning for Alzheimer's patients. 相似文献
909.
Huang Y Fong Y Wei J Feng Z 《Journal of the Royal Statistical Society. Series C, Applied statistics》2011,60(5):633-653
A marker's capacity to predict risk of a disease depends on disease prevalence in the target population and its classification accuracy, i.e. its ability to discriminate diseased subjects from non-diseased subjects. The latter is often considered an intrinsic property of the marker; it is independent of disease prevalence and hence more likely to be similar across populations than risk prediction measures. In this paper, we are interested in evaluating the population-specific performance of a risk prediction marker in terms of positive predictive value (PPV) and negative predictive value (NPV) at given thresholds, when samples are available from the target population as well as from another population. A default strategy is to estimate PPV and NPV using samples from the target population only. However, when the marker's classification accuracy as characterized by a specific point on the receiver operating characteristics (ROC) curve is similar across populations, borrowing information across populations allows increased efficiency in estimating PPV and NPV. We develop estimators that optimally combine information across populations. We apply this methodology to a cross-sectional study where we evaluate PCA3 as a risk prediction marker for prostate cancer among subjects with or without previous negative biopsy. 相似文献
910.
John J. McArdle 《AStA Advances in Statistical Analysis》2011,95(4):453-480
The purpose of this paper is to highlight some classic issues in the measurement of change and to show how contemporary solutions
can be used to deal with some of these issues. Five classic issues will be raised here: (1) Separating individual changes
from group differences; (2) options for incomplete longitudinal data over time, (3) options for nonlinear changes over time;
(4) measurement invariance in studies of changes over time; and (5) new opportunities for modeling dynamic changes. For each
issue we will describe the problem, and then review some contemporary solutions to these problems base on Structural Equation
Models (SEM). We will fit these SEM to using existing panel data from the Health & Retirement Study (HRS) cognitive variables.
This is not intended as an overly technical treatment, so only a few basic equations are presented, examples will be displayed
graphically, and more complete references to the contemporary solutions will be given throughout. 相似文献