Objective: Appropriate treatment at designated trauma centers (TCs) improves outcomes among injured children after motor vehicle crashes (MVCs). Advanced Automatic Crash Notification (AACN) has shown promise in improving triage to appropriate TCs. Pediatric-specific AACN algorithms have not yet been created. To create such an algorithm, it will be necessary to include some metric of development (age, height, or weight) as a covariate in the injury risk algorithm. This study sought to determine which marker of development should serve as a covariate in such an algorithm and to quantify injury risk at different levels of this metric.
Methods: A retrospective review of occupants age < 19 years within the MVC data set NASS-CDS 2000–2011 was performed. R2 values of logistic regression models using age, height, or weight to predict 18 key injury types were compared to determine which metric should be used as a covariate in a pediatric AACN algorithm. Clinical judgment, literature review, and chi-square analysis were used to create groupings of the chosen metric that would discriminate injury patterns. Adjusted odds of particular injury types at the different levels of this metric were calculated from logistic regression while controlling for gender, vehicle velocity change (delta V), belted status (optimal, suboptimal, or unrestrained), and crash mode (rollover, rear, frontal, near-side, or far-side).
Results: NASS-CDS analysis produced 11,541 occupants age < 19 years with nonmissing data. Age, height, and weight were correlated with one another and with injury patterns. Age demonstrated the best predictive power in injury patterns and was categorized into bins of 0–4 years, 5–9 years, 10–14 years, and 15–18 years. Age was a significant predictor of all 18 injury types evaluated even when controlling for all other confounders and when controlling for age- and gender-specific body mass index (BMI) classifications. Adjusted odds of key injury types with respect to these age categorizations revealed that younger children were at increased odds of sustaining Abbreviated Injury Scale (AIS) 2+ and 3+ head injuries and AIS 3+ spinal injuries, whereas older children were at increased odds of sustaining thoracic fractures, AIS 3+ abdominal injuries, and AIS 2+ upper and lower extremity injuries.
Conclusions: The injury patterns observed across developmental metrics in this study mirror those previously described among children with blunt trauma. This study identifies age as the metric best suited for use in a pediatric AACN algorithm and utilizes 12 years of data to provide quantifiable risks of particular injuries at different levels of this metric. This risk quantification will have important predictive purposes in a pediatric-specific AACN algorithm. 相似文献
The social environment can exert a powerful influence on the expression of an individual’s behaviour patterns. For example,
social facilitation occurs where individuals are more likely to express a given behaviour, or express it a greater rate, in
the presence of conspecifics. Social facilitation is partly driven by an individual’s perception of risk, which is a function
both of the size of its social group and the information that it gathers relating to predator activity and risk. Here I tested
the effects of social group size (one, two, four, eight or 16 fish) and the presence of ‘social’, ‘predation’ or ‘neutral’
chemical cues (derived respectively from live conspecifics, injured conspecifics or a blank water control) on the exploratory
behaviour of juvenile mosquitofish (Gambusia holbrooki) in a novel environment. Focal fish in larger groups explored a greater proportion of the arena during the course of the
experiment, demonstrating social facilitation of exploration. After 4 h in the arena, focal fish in all group sizes showed
significantly reduced swimming activity, suggesting that the initial faster swimming activity of fish on entry to the arena
may be in response to the motivation to explore. The presence of predation cues in the environment had the effect of reducing
exploratory behaviour across groups in a novel environment, whereas social cues had no effect on exploratory behaviour. Taken
as a whole, these results suggest that there is a high degree of context dependency in the expression of exploratory behaviour,
with a strong influence of both the presence of conspecifics and cues relating to potential danger. 相似文献
Algal populations, either suspended in the water column (planktonic) or present on the walls of an enclosure (periphytic), develop differently depending upon the physical scale of the system. This study determined whether these variations altered the speciation and therefore exposure of polychlorinated biphenyls (PCBs) in estuarine mesocosms. Exposure was defined as the fraction of applied contaminant taken up by plankton after two hours. Using a three phase equilibrium model, the partitioning of a suite of PCBs within variously-sized mesocosms was predicted using laboratory derived distribution coefficients and measured levels of planktonic and periphytic algal biomass. in mesocosms having large wall surface area to volume ratios, sorption of hydrophobic PCBs to periphyton significantly decreased contaminant exposure. However, within the range of planktonic algal biomasses observed in this study, the regulation of PCB exposure was relatively invariant between variously-sized mesocosms. to minimize sorption of hydrophobic organic contaminants (HOCs) to periphyton and reduce artefacts inherent with this partitioning, we suggest using mesocosms with low wall surface area to volume ratios (less than or equal to 1). in addition, periphytic biomass should be quantified regularly and a three-phase equilibrium approach used to predict the actual exposure concentrations. 相似文献
The benefits of grouping behaviour may not be equally distributed across all individuals within a group, leading to conflict
over group membership among established group members, and between residents and outsiders attempting to join a group. Although
the interaction between the preferences of joining individuals and existing group members may exert considerable pressure
on group structure, empirical work on group living to date has focussed on free entry groups, in which all individuals are
permitted entry. Using the humbug damselfish, Dascyllus aruanus, we examined a restricted entry grouping system, in which group residents control membership by aggressively rejecting potential
new members. We found that the preferences shown by joining members were not always aligned with strategies that incurred
the least harm from resident group members, suggesting a conflict between the preferences of residents and preferences of
group joiners. Solitary fish preferred to join familiar groups and groups of size-matched residents. Residents were less aggressive
towards familiar group joiners. However, resident aggression towards unfamiliar individuals depended on the size of the joining
individual, the size of the resident and the composition of the group. These results demonstrate that animal group structure
is mediated by both the preferences of joining individuals and the preferences of residents. 相似文献
Several occupational exposure limits and guidelines exist for silver, but the values for each depend on the chemical form of the silver compound in question. In the past, it generally was not possible, without prior knowledge of the work process, to distinguish soluble silver from insoluble silver compounds collected in workplace air samples. Therefore, analytical results were historically reported as total silver. In this study, work was conducted to evaluate a method to differentiate between the quantities of water-soluble silver compounds and total silver collected on filters. The investigation entailed an evaluation of an International Organization for Standardization method to determine soluble silver in airborne particulate matter. The study design incorporated laboratory experiments to evaluate analytical figures of merit, such as selection of appropriate filter media and extraction solution, analytical recovery, and sample stability during storage. Polytetrafluoroethylene (PTFE) filters (2 microm, 37 mm) in opaque cassettes were either spiked with known amounts of silver nitrate or contained a known mass of solid silver nitrate. Results showed that over 90% of the silver was recovered from PTFE filters. Also, field studies were conducted in which workplace air samples were collected in two silver refineries. Some of these samples were analyzed only for soluble silver while others were sequentially extracted and analyzed, first, for soluble silver, then for total silver. The mass fractions of soluble silver, as compared to total silver, were approximately 2% or less. This investigation served to validate an international standard procedure for the determination of soluble silver in workplace air samples. 相似文献
Monitoring of stream restoration projects is often limited and success often focuses on a single taxon (e.g., salmonids),
even though other aspects of stream structure and function may also respond to restoration activities. The Ottawa National
Forest (ONF), Michigan, conducted a site-specific trout habitat improvement to enhance the trout fishery in Cook’s Run, a
3rd-order stream that the ONF determined was negatively affected by past logging. Our objectives were to determine if the habitat
improvement increased trout abundances and enhanced other ecological variables (overall habitat quality, organic matter retention,
seston concentration, periphyton abundance, sediment organic matter content, and macroinvertebrate abundance and diversity)
following rehabilitation. The addition of skybooms (underbank cover structures) and k-dams (pool-creating structures) increased
the relative abundance of harvestable trout (>25 cm in total length) as intended but not overall trout abundances. Both rehabilitation
techniques also increased maximum channel depth and organic matter retention, but only k-dams increased overall habitat quality.
Neither approach significantly affected other ecological variables. The modest ecological response to this habitat improvement
likely occurred because the system was not severely degraded beforehand, and thus small, local changes in habitat did not
measurably affect most physical and ecological variables measured. However, increases in habitat volume and in organic matter
retention may enhance stream biota in the long term. 相似文献
Introduction. Cooling of the body is used to treat hyperthermic individuals with heatstroke or to depress core temperature below normal for neuroprotection. A novel, chemically activated, unpowered cooling device, CAERvest®, was investigated for safety and efficacy. Methods. Eight healthy male participants (body mass 79.9?±?1.9?kg and body fat percentage 16.1?±?3.8%) visited the laboratory (20 °C, 40% relative humidity) on four occasions. Following 30-min rest, physiological and perceptual measures were recorded. Participants were then fitted with the CAERvest® proof of concept (PoC) or prototype 1 (P1), 2 (P2) or 3 (P3) for 60 min. Temperature, cardiovascular and perceptual measures were recorded every 5 min. After cooling, the CAERvest® was removed and the torso checked for cold-related injuries. Results. Temperature measures significantly (p?0.05) reduced pre to post in all trials. Larger reductions in core and skin temperatures were observed for PoC (?0.36?±?0.18 and ?1.55?±?0.97 °C) and P3 (?0.36?±?0.22 and ?2.47?±?0.82 °C), compared with P1 and P2. No signs of cold-related injury were observed at any stage. Conclusion. This study demonstrates that the CAERvest® is an effective device for reducing body temperature in healthy normothermic individuals without presence of cold injury. Further research in healthy and clinical populations is warranted. 相似文献