A comparison of injuries, crashes, and outcomes for pediatric rear occupants in traffic motor vehicle collisions

BACKGROUND This study was initiated was initiated to describe pediatric rear-occupant motor vehicle collision (MVC) injuries, including injury patterns and outcomes as well as characteristics associated with severe injury to the head and abdomen. METHODS A retrospective cohort of severely injured (Injury Severity Score [ISS] \u3e 12) pediatric (age \u3c18 years) patients involved in a traffic MVC as a rear occupant and treated at one of two Ontario trauma centers (2001–2010) was studied was studied. Demographic, injury, crash and outcome data were obtained from the trauma registries. Data were statistically compared by two pediatric age groups: children (0–8 years; requiring a child or booster seat) versus adolescents (9–17 years; requiring a lap-shoulder belt). RESULTS There were 36 children (34%) and 70 adolescents (66%) severely injured as rear occupants in MVCs. Despite similar ISS (p = 0.716) and mortality rates (p = 0.680) between age groups, there were significant differences in injury patterns and risk factors. Children were more likely to have severe head injuries (78% vs. 39%, p \u3c 0.001) associated with a lack of an age-appropriate child restraints (odds ratio [OR], 3.5; 95% confidence interval [CI], 1.1–10.8; p = 0.029), middle seating (OR, 6.2; 95% CI, 1.5–26.1; p = 0.013), and side-impact crashes (p = 0.007). Adolescents were more likely to have severe abdominal injuries (23% vs. 6%, p \u3c 0.001) associated with the use of lap-shoulder belts (OR, 3.8; 95% CI, 1.1–13.3; p = 0.034), single-vehicle MVCs (p = 0.007), and vehicle extrications (p = 0.035). CONCLUSION While safer than the front seat for children, additional study is needed on the restraint systems and the potential for injury to pediatric rear occupants in an MVC. Our data suggest that pediatric age groups differ in injuries, risk factors, and MVC impacts. Recommendations for improved protection of child occupants and preferred seating positions are required

The James Webb Space Telescope Mission

Twenty-six years ago a small committee report, building on earlier studies, expounded a compelling and poetic vision for the future of astronomy, calling for an infrared-optimized space telescope with an aperture of at least $4m$. With the support of their governments in the US, Europe, and Canada, 20,000 people realized that vision as the $6.5m$ James Webb Space Telescope. A generation of astronomers will celebrate their accomplishments for the life of the mission, potentially as long as 20 years, and beyond. This report and the scientific discoveries that follow are extended thank-you notes to the 20,000 team members. The telescope is working perfectly, with much better image quality than expected. In this and accompanying papers, we give a brief history, describe the observatory, outline its objectives and current observing program, and discuss the inventions and people who made it possible. We cite detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space Telescope Overview, 29 pages, 4 figure

Response of the Arctic Pteropod Limacina helicina to Projected Future Environmental Conditions

Thecosome pteropods (pelagic mollusks) can play a key role in the food web of various marine ecosystems. They are a food source for zooplankton or higher predators such as fishes, whales and birds that is particularly important in high latitude areas. Since they harbor a highly soluble aragonitic shell, they could be very sensitive to ocean acidification driven by the increase of anthropogenic CO2 emissions. The effect of changes in the seawater chemistry was investigated on Limacina helicina, a key species of Arctic pelagic ecosystems. Individuals were kept in the laboratory under controlled pCO2 levels o

Seawater carbonate chemistry in Kongsfjorden, Svalbard, May 2009

Thecosome pteropods (pelagic mollusks) can play a key role in the food web of various marine ecosystems. They are a food source for zooplankton or higher predators such as fishes, whales and birds that is particularly important in high latitude areas. Since they harbor a highly soluble aragonitic shell, they could be very sensitive to ocean acidification driven by the increase of anthropogenic CO2 emissions. The effect of changes in the seawater chemistry was investigated on Limacina helicina, a key species of Arctic pelagic ecosystems. Individuals were kept in the laboratory under controlled pCO2 levels of 280, 380, 550, 760 and 1020 µatm and at control (0°C) and elevated (4°C) temperatures. The respiration rate was unaffected by pCO2 at control temperature, but significantly increased as a function of the pCO2 level at elevated temperature. pCO2 had no effect on the gut clearance rate at either temperature. Precipitation of CaCO3, measured as the incorporation of 45Ca, significantly declined as a function of pCO2 at both temperatures. The decrease in calcium carbonate precipitation was highly correlated to the aragonite saturation state. Even though this study demonstrates that pteropods are able to precipitate calcium carbonate at low aragonite saturation state, the results support the current concern for the future of Arctic pteropods, as the production of their shell appears to be very sensitive to decreased pH. A decline of pteropod populations would likely cause dramatic changes to various pelagic ecosystems

Seawater carbonate chemistry and biological processes during experiments with Limacina helicina, 2009

Thecosome pteropods (pelagic mollusks) can play a key role in the food web of various marine ecosystems. They are a food source for zooplankton or higher predators such as fishes, whales and birds that is particularly important in high latitude areas. Since they harbor a highly soluble aragonitic shell, they could be very sensitive to ocean acidification driven by the increase of anthropogenic CO2 emissions. The effect of changes in the seawater chemistry was investigated on Limacina helicina, a key species of Arctic pelagic ecosystems. Individuals were kept in the laboratory under controlled pCO2 levels of 280, 380, 550, 760 and 1020 µatm and at control (0°C) and elevated (4°C) temperatures. The respiration rate was unaffected by pCO2 at control temperature, but significantly increased as a function of the pCO2 level at elevated temperature. pCO2 had no effect on the gut clearance rate at either temperature. Precipitation of CaCO3, measured as the incorporation of 45Ca, significantly declined as a function of pCO2 at both temperatures. The decrease in calcium carbonate precipitation was highly correlated to the aragonite saturation state. Even though this study demonstrates that pteropods are able to precipitate calcium carbonate at low aragonite saturation state, the results support the current concern for the future of Arctic pteropods, as the production of their shell appears to be very sensitive to decreased pH. A decline of pteropod populations would likely cause dramatic changes to various pelagic ecosystems

Limacina helicina size weight relationship in Kongsfjorden Svalbard, May 2009

Thecosome pteropods (pelagic mollusks) can play a key role in the food web of various marine ecosystems. They are a food source for zooplankton or higher predators such as fishes, whales and birds that is particularly important in high latitude areas. Since they harbor a highly soluble aragonitic shell, they could be very sensitive to ocean acidification driven by the increase of anthropogenic CO2 emissions. The effect of changes in the seawater chemistry was investigated on Limacina helicina, a key species of Arctic pelagic ecosystems. Individuals were kept in the laboratory under controlled pCO2 levels of 280, 380, 550, 760 and 1020 µatm and at control (0°C) and elevated (4°C) temperatures. The respiration rate was unaffected by pCO2 at control temperature, but significantly increased as a function of the pCO2 level at elevated temperature. pCO2 had no effect on the gut clearance rate at either temperature. Precipitation of CaCO3, measured as the incorporation of 45Ca, significantly declined as a function of pCO2 at both temperatures. The decrease in calcium carbonate precipitation was highly correlated to the aragonite saturation state. Even though this study demonstrates that pteropods are able to precipitate calcium carbonate at low aragonite saturation state, the results support the current concern for the future of Arctic pteropods, as the production of their shell appears to be very sensitive to decreased pH. A decline of pteropod populations would likely cause dramatic changes to various pelagic ecosystems

Seawater carbonate chemistry, shell linear extension and calcification during calcein staining and 45Ca experiments with pteropod Limacina helicina, 2009

Thecosome pteropods (shelled pelagic molluscs) can play an important role in the food web of various ecosystems and play a key role in the cycling of carbon and carbonate. Since they harbor an aragonitic shell, they could be very sensitive to ocean acidification driven by the increase of anthropogenic CO2 emissions. The impact of changes in the carbonate chemistry was investigated on Limacina helicina, a key species of Arctic ecosystems. Pteropods were kept in culture under controlled pH conditions corresponding to pCO2 levels of 350 and 760 µatm. Calcification was estimated using a fluorochrome and the radioisotope 45Ca. It exhibits a 28 % decrease at the pH value expected for 2100 compared to the present pH value. This result supports the concern for the future of pteropods in a high-CO2 world, as well as of those species dependent upon them as a food resource. A decline of their populations would likely cause dramatic changes to the structure, function and services of polar ecosystems

Plural leadership in healthcare organizations

Because of their complex structures and cultures characterized by interaction among multiple professional and occupational groups with diverse sources of authority, expertise and legitimacy, health care organizations are prime sites for forms of collective or plural leadership. In this chapter, we describe and provide empirical examples of four different forms of plural leadership occurring in and around health care organizations. The presentation of the various forms and their empirical illustrations reveals that different situations may call for different forms and modalities of plural leadership both inside and across these organizations. However, a common theme underlying all the examples and forms is the paradoxical importance of individual agency in enabling the construction of effective forms of plurality. We conclude by discussing some of the challenges associated with these forms of plural leadership and by identifying areas for future study of their role and effectiveness in health care settings.</p

Les comptes rendus de la XVII e Conférence canadienne multidisciplinaire sur la sécurité routière; 3 au 6 juin 2007; Montréal, Québec Proceedings of the Canadian Multidisciplinary Road Safety Conference XVII; A COMPARISON OF REAL WORLD FRONTAL IMPACTS AND

Abstract Real world evaluations of motor vehicle crash protection safety features require measures for quantifying impact severity. Velocity change (delta-V) is the primary descriptor of collision severity used in most databases Résumé Des évaluations concrètes des dispositifs de protection des véhicules automobiles contre les impacts exigent des mesures afin de quantifier la sévérité des impacts. La variation de vitesse (delta V) constitue la description principale de la sévérité des collisions utilisée dans la plupart des bases de données sur les collisions réelles. De par le passé, le facteur delta V a été calculé à l&apos;aide de techniques classiques de reconstitution d&apos;accidents, comme par exemple l&apos;analyse des dégâts ou du momentum. Une lacune importante de l&apos;utilisation du seul facteur delta V comme mesure de sévérité de collision est l&apos;absence d&apos;information sur la durée de variation de vitesse, le facteur delta t de la collision. Les modèles récents de véhicules munis d&apos;enregistreurs de données d