Methodology of estimating restraint use in children: Roadside observation or parking lot interview survey

Objective

To compare the differences in Canadian national estimates of correct child restraint use obtained using the standard roadside observation method compared to a detailed parking lot interview.

Design

A multi-stage stratified survey design was used to conduct roadside observational and interview data collection at 182 randomly selected sites across Canada. For each site, a roadside intersection location and a parking lot location were used for the roadside observational survey and the interview respectively. Weighted estimates of correct restraint use from both locations were compared.

Results

Estimates of correct restraint use were significantly higher for all children under the age of 9 in the parking lot sample. The largest discrepancy between the two samples was in booster seat aged children (ages 4–8) where 29.1% versus 67.8% of children were observed to be correctly restrained using the roadside and the parking lot methodology respectively. There was a 67% participation refusal rate in the parking lot survey.

Conclusions

There are specific advantages and limitations to both survey designs. The purpose of the data collection must be considered when selecting the methodology. Parking lot surveys provide richer data regarding restraint use/misuse. Estimates of correct restraint use must be approached with caution due to the effect of consent bias resulting in over inflation of estimates. Roadside observation is adequate and appropriate for providing national estimates of correct restraint use.     

Urban planning historical review of master plans and the way towards a sustainable city: Dar es Salaam,Tanzania

Urban planning in Tanzania has focused mainly on economic development. The Tanzanian government prioritizes large-scale modern projects to increase national income and propel world-class urban settlements. Dar es Salaam, Tanzania׳s largest city and main commercial center has experienced remarkable urban development. Unfortunately, its growth has not been consistent with the master plans, which also overlook sustainable urban development aspects. The high urbanization rate has exacerbated the degradation of the city׳s environment, including roadside air quality, solid waste, and water quality. The city׳s ongoing environmental dilapidation has led to a call for a sustainable urbanization to curb past urbanization problems and implement a sustainable future. This work reviews Dar es Salaam׳s available planning documents and examines how master plans can stimulate sustainable urban development. Findings suggest that master plans should not be used as a mere urban growth control tool. Master plans that are designed and conceptualized as a comprehensive strategy and integrated with different aspects of urban development can play a key role in enforcing sustainable urban development for the city.     

Correlation between arterial blood volume obtained by arterial spin labelling and cerebral blood volume in intracranial tumours

Objective  

To compare measurements of the arterial blood volume (aBV), a perfusion parameter calculated from arterial spin labelling (ASL), and cerebral blood volume (CBV), calculated from dynamic susceptibility contrast (DSC) MRI. In the clinic, CBV is used for grading of intracranial tumours.     

Robust imaging of hippocampal inner structure at 7T: in vivo acquisition protocol and methodological choices

Objective

Motion-robust multi-slab imaging of hippocampal inner structure in vivo at 7T.

Materials and methods

Motion is a crucial issue for ultra-high resolution imaging, such as can be achieved with 7T MRI. An acquisition protocol was designed for imaging hippocampal inner structure at 7T. It relies on a compromise between anatomical details visibility and robustness to motion. In order to reduce acquisition time and motion artifacts, the full slab covering the hippocampus was split into separate slabs with lower acquisition time. A robust registration approach was implemented to combine the acquired slabs within a final 3D-consistent high-resolution slab covering the whole hippocampus. Evaluation was performed on 50 subjects overall, made of three groups of subjects acquired using three acquisition settings; it focused on three issues: visibility of hippocampal inner structure, robustness to motion artifacts and registration procedure performance.

Results

Overall, T2-weighted acquisitions with interleaved slabs proved robust. Multi-slab registration yielded high quality datasets in 96 % of the subjects, thus compatible with further analyses of hippocampal inner structure.

Conclusion

Multi-slab acquisition and registration setting is efficient for reducing acquisition time and consequently motion artifacts for ultra-high resolution imaging of the inner structure of the hippocampus.

     

Hydroxylated polybrominated diphenyl ethers (OH-PBDEs) in the abiotic environment: surface water and precipitation from Ontario, Canada

Hydroxylated polybrominated diphenyl ethers (OH-PBDEs) have been identified as metabolites of PBDEs, and also as compounds of natural origin in the marine environment; however, there has only been very limited study of their presence in the abiotic environment. In the present study, OH-PBDEs were determined in samples of surface water and precipitation (rain and snow) collected from sites in Ontario, Canada. OH-PBDEs were detected in all the samples analyzed, although half of the observed peaks did not correspond to any of the 18 authentic standards available. Fluxes of sigmaOH-PBDEs ranged from 3.5 to 190 pg/m2 in snow and from 15 to 170 pg/m2/day in rain, and those were higher at three of the southern Ontario locations relative to a single northern remote site. Concentrations of sigmaOH-PBDEs ranged from 2.2 to 70 pg/L in water and from < 1 to 420 pg/g in particulate organic carbon (POC), and higher values were found near sewage treatment plant (STP) outfalls in Lake Ontario. Partition coefficients (log K(oc)) for OH-PBDEs ranged from 4.0 to 5.1. The results in this study suggest that OH-PBDEs are ubiquitous in the abiotic environment and most likely are produced through reaction of PBDEs with atmospheric OH radicals. As well, they may be present in surface waters near STPs due to oxidation of PBDEs and inflows from metabolism by humans and animals.