Objective: This article aims to describe seat belt wearing patterns and quality of seat belt fit among drivers aged 75 years and older. A secondary aim is to explore associations between body shape, comfort, and seat belt use patterns.
Methods: This is an observation and survey study of a cohort of 380 drivers aged 75 years and over. During home visits, photographs were taken of the drivers in their vehicles for later analysis of belt fit and a short survey was also administered to collect demographic data and information about seat belt use and comfort. Seat belt fit and use of belt and seat accessories were analyzed from the photographs.
Results: Data from 367 participants with photographs were analyzed. Whereas 97% reported using a seat belt and 90% reported their seat belt to be comfortable, 21% reported repositioning their seat belt to improve comfort. Good sash and lap belt fit were achieved in 53 and 59% of participants, respectively, but only 35% achieved overall good fit. Both poor sash and lap belt fit were observed in 23% of participants. Drivers who were in the obese category had over twice the odds (95% confidence interval [CI], 1.2–4.1) of having a poor lap belt fit than those in the normal body mass index [BMI] range, and drivers who were overweight had 1.8 times the odds (95% CI, 1.1–2.9) of having poor lap belt fit. Older females also had twice the odds (95% CI, 1.3–3.5) of poor lap belt fit compared to older males, regardless of BMI. Sash belt fit did not vary significantly by BMI, stature, or gender. However older drivers who reported that they had not made any adjustments to the D-ring height had 1.7 times the odds of having poor sash belt fit than those who made adjustments (1.2–2.9). Females were 7.3 times more likely to report comfort problems than males (95% CI, 3.2, 16.3) but there was no association between reported comfort and BMI or seat belt fit. Drivers who reported comfort problems had 6 times the odds (3.2–13.6) of also reporting active repositioning of the belt.
Conclusions: The results suggest that older drivers face challenges in achieving comfortable and correct seat belt fit. This may have a negative impact on crash protection. Belt fit problems appear to be associated with body shape, particularly high BMI and gender. There is a need for further investigation of comfort accessories; in the interim, older drivers and occupants should be encouraged to use features such as D-ring adjusters to improve sash belt fit. 相似文献
Rare, small or annual vegetation species are widely known to be imperfectly detected with single site surveys by most conventional
vegetation survey methods. However, the detectability of common, persistent vegetation species is assumed to be high, but
without supporting research. In this study, we evaluate the extent of false-negative errors of perennial vegetation species
in a systematic vegetation survey in arid South Australia. Analysis was limited to the seven most easily detected persistent
vegetation species and controlled for observer skill. By comparison of methodologies, we then predict the magnitude of non-detection
error rates in a second survey. The analysis revealed that all but one highly detectable perennial vegetation species was
imperfectly detected (detection probabilities ranged from 0.22 to 0.83). While focussed in the Australian rangelands, the
implications of this study are far reaching. Inferences drawn from systematic vegetation surveys that fail to identify and
account for non-detection errors should be considered potentially flawed. The identification of this problem in vegetation
surveying is long overdue. By comparison, non-detection has been a widely acknowledged, and dealt with, problem in fauna surveying
for decades. We recommend that, where necessary, vegetation survey methodology adopt the methods developed in fauna surveying
to cope with non-detection errors. 相似文献
A study of water quality, land use, and population variations over the past three decades was conducted in eastern Massachusetts
to examine the impact of urban sprawl on water quality using geographic information system and statistical analyses. Since
1970, eastern Massachusetts has experienced pronounced urban sprawl, which has a substantial impact on water quality. High
spatial correlations are found between water quality indicators (especially specific conductance, dissolved ions, including
Ca, Mg, Na, and Cl, and dissolved solid) and urban sprawl indicators. Urbanized watersheds with high population density, high
percentage of developed land use, and low per capita developed land use tended to have high concentrations of water pollutants.
The impact of urban sprawl also shows clear spatial difference between suburban areas and central cities: The central cities
experienced lower increases over time in specific conductance concentration, compared to suburban and rural areas. The impact
of urban sprawl on water quality is attributed to the combined effects of population and land-use change. Per capita developed
land use is a very important indicator for studying the impact of urban sprawl and improving land use and watershed management,
because inclusion of this indicator can better explain the temporal and spatial variations of more water quality parameters
than using individual land use or/and population density. 相似文献
The conversion of natural habitat to urban settlements is a primary driver of biodiversity loss, and species' persistence is threatened by the extent, location, and spatial pattern of development. Urban growth models are widely used to anticipate future development and to inform conservation management, but the source of spatial input to these models may contribute to uncertainty in their predictions. We compared two sources of historic urban maps, used as input for model calibration, to determine how differences in definition and scale of urban extent affect the resulting spatial predictions from a widely used urban growth model for San Diego County, CA under three conservation scenarios. The results showed that rate, extent, and spatial pattern of predicted urban development, and associated habitat loss, may vary substantially depending on the source of input data, regardless of how much land is excluded from development. Although the datasets we compared both represented urban land, different types of land use/land cover included in the definition of urban land and different minimum mapping units contributed to the discrepancies. Varying temporal resolution of the input datasets also contributed to differences in projected rates of development. Differential predicted impacts to vegetation types illustrate how the choice of spatial input data may lead to different conclusions relative to conservation. Although the study cannot reveal whether one dataset is better than another, modelers should carefully consider that geographical reality can be represented differently, and should carefully choose the definition and scale of their data to fit their research objectives. 相似文献
Life-history characteristics exert a profound influence upon the population structure of many marine organisms. However, relatively
few genetic studies have compared direct with indirect-developing species in the same ecosystem or geographical region, and
none to our knowledge within an Antarctic setting. To address this issue, we have collected novel amplified fragment length
polymorphism (AFLP) data from the direct-developing top shell Margarella antarctica to form a comparison with previously published data for the broadcast-spawning Antarctic limpet Nacella concinna. We scored 270 loci in 240 M. antarctica individuals sampled from five populations spanning the full length of the Antarctic Peninsula. Profound differences were
identified in the strength and pattern of population structure between the two species, consistent with gene flow being highly
restricted in M. antarctica relative to N. concinna. 相似文献
To evaluate the test accuracy of non-invasive prenatal testing (NIPT) for fetal trisomy 21, 18, and 13 using cell-free (cf) DNA analysis in maternal plasma with microarray quantitation.
Method
Systematic review and meta-analysis. Searches in MEDLINE, Pre-MEDLINE, EMBASE, Web of Science, and the Cochrane Library to 09.07.2018.
Results
Five studies analyzing 3074 samples, including 187 trisomy 21, 43 trisomy 18, and 19 trisomy 13 cases, were identified. Risk of bias was high in all studies, introduced particularly by exclusions from analysis and by the role of the sponsor. Sensitivity of microarray-based cfDNA testing was 99.5% (95%CI 96.3%-99.9%) for trisomy 21, 97.7% (95%CI 87.9%-99.6%) for trisomy 18, and 100% (95%CI 83.2%-100%) for trisomy 13. Specificity was 100% (95% CI 99.87%-100%) for trisomy 21, 99.97% (95%CI 99.81%-99.99%) for trisomy 18, and 99.97% (95%CI 99.81%-99.99%) for trisomy 13. Pooled test failure rate was 1.1%. A direct comparison of microarray- and sequencing-based cfDNA found equivalent test accuracy.
Conclusion
Included studies suggest that NIPT using microarray-based cfDNA testing has high sensitivity and specificity for detecting fetal trisomy 21, 18, and 13. However, the evidence base is small and at high risk of bias. 相似文献