Operational Remote Sensing of Sea Ice

The Ice Branch of Environment Canada's Atmospheric Environment Service is responsible for providing information about ice conditions in Canada's offshore areas. Principal clients include the Canadian Coast Guard, commercial shipping companies, the oil and gas industry and fishermen, who all require accurate information on ice distribution in near real-time. In order to provide this information, the Ice Branch employs a Challenger jet aircraft equipped with dual wide-swath synthetic aperture radars and a Dash-7 equipped with a real aperture side-looking airborne radar. These aircraft image approximately 100 million sq km annually. Radar image data from these aircraft are downlinked during flight via an S-band telemetry link to Coast Guard icebreakers and to satellite stations in the Ice Reconnaissance Data Network, which relays the data to the Ice Centre in Ottawa. There, the data are integrated with remotely sensed data from satellites and are used as the basis for ice analysis charts produced and distributed by radio facsimile on a daily basis.Key words: sea ice, remotes ensing, Arctic, radar, shipping,s atellite, data communicationMots clés: glace de mer, télé-détection, arctique, radar, navigation, satellite, communications digitale

The extinct, giant giraffid Sivatherium giganteum: skeletal reconstruction and body mass estimation

Sivatherium giganteum is an extinct giraffid from the Plio–Pleistocene boundary of the Himalayan foothills. To date, there has been no rigorous skeletal reconstruction of this unusual mammal. Historical and contemporary accounts anecdotally state that Sivatherium rivalled the African elephant in terms of its body mass, but this statement has never been tested. Here, we present a three-dimensional composite skeletal reconstruction and calculate a representative body mass estimate for this species using a volumetric method. We find that the estimated adult body mass of 1246 kg (857—1812 kg range) does not approach that of an African elephant, but confirms that Sivatherium was certainly a large giraffid, and may have been the largest ruminant mammal that has ever existed. We contrast this volumetric estimate with a bivariate scaling estimate derived from Sivatherium's humeral circumference and find that there is a discrepancy between the two. The difference implies that the humeral circumference of Sivatherium is greater than expected for an animal of this size, and we speculate this may be linked to a cranial shift in centre of mass

Assessing household wealth in health studies in developing countries: a comparison of participatory wealth ranking and survey techniques from rural South Africa

BACKGROUND: Accurate tools for assessing household wealth are essential for many health studies in developing countries. Household survey and participatory wealth ranking (PWR) are two approaches to generate data for this purpose. METHODS: A household survey and PWR were conducted among eight villages in rural South Africa. We developed three indicators of household wealth using the data. One indicator used PWR data only, one used principal components analysis to combine data from the survey, while the final indicator used survey data combined in a manner informed by the PWR. We assessed internal consistency of the indices and assessed their level of agreement in ranking household wealth. RESULTS: Food security, asset ownership, housing quality and employment were important indicators of household wealth. PWR, consisting of three independent rankings of 9671 households, showed a high level of internal consistency (intraclass correlation coefficient 0.81, 95% CI 0.79-0.82). Data on 1429 households were available from all three techniques. There was moderate agreement in ranking households into wealth tertiles between the two indicators based on survey data (spearman rho = 0.69, kappa = 0.43), but only limited agreement between these techniques and the PWR data (spearman rho = 0.38 and 0.31, kappa = 0.20 and 0.17). CONCLUSION: Both PWR and household survey can provide a rapid assessment of household wealth. Each technique had strengths and weaknesses. Reasons for differences might include data inaccuracies or limitations in the methods by which information was weighted. Alternatively, the techniques may measure different things. More research is needed to increase the validity of measures of socioeconomic position used in health studies in developing countries

Overview of migration, poverty and health dynamics in Nairobi City's slum settlements

The Urbanization, Poverty, and Health Dynamics research program was designed to generate and provide the evidence base that would help governments, development partners, and other stakeholders understand how the urban slum context affects health outcomes in order to stimulate policy and action for uplifting the wellbeing of slum residents. The program was nested into the Nairobi Urban Health and Demographic Surveillance System, a uniquely rich longitudinal research platform, set up in Korogocho and Viwandani slum settlements in Nairobi city, Kenya. Findings provide rich insights on the context in which slum dwellers live and how poverty and migration status interacts with health issues over the life course. Contrary to popular opinions and beliefs that see slums as homogenous residential entities, the findings paint a picture of a highly dynamic and heterogeneous setting. While slum populations are highly mobile, about half of the population comprises relatively well doing long-term dwellers who have lived in slum settlements for over 10 years. The poor health outcomes that slum residents exhibit at all stages of the life course are rooted in three key characteristics of slum settlements: poor environmental conditions and infrastructure; limited access to services due to lack of income to pay for treatment and preventive services; and reliance on poor quality and mostly informal and unregulated health services that are not well suited to meeting the unique realities and health needs of slum dwellers. Consequently, policies and programs aimed at improving the wellbeing of slum dwellers should address comprehensively the underlying structural, economic, behavioral, and service-oriented barriers to good health and productive lives among slum residents

Underutilization of Social Insurance among the Poor: Evidence from the Philippines

Many developing countries promote social health insurance as a means to eliminate unmet health needs. However, this strategy may be ineffective if there are barriers to fully utilizing insurance.We analyzed the utilization of social health insurance in 30 hospital districts in the central regions of the Philippines between 2003 and 2007. Data for the study came from the Quality Improvement Demonstration Study (QIDS) and included detailed patient information from exit interviews of children under 5 years of age conducted in seven waves among public hospital districts located in the four central regions of the Philippines. These data were used to estimate and identify predictors of underutilization of insurance benefits--defined as the likelihood of not filing claims despite having legitimate insurance coverage--using logistic regression.Multivariate analyses using QIDS data from 2004 to 2007 reveal that underutilization averaged about 15% throughout the study period. Underutilization, however, declined over time. Among insured hospitalized children, increasing length of stay in the hospital and mother's education, were associated with less underutilization. Being in a QIDS intervention site was also associated with less underutilization and partially accounts for the downward trend in underutilization over time.The surprisingly high level of insurance underutilization by insured patients in the QIDS sites undermines the potentially positive impact of social health insurance on the health of the marginalized. In the Philippines, where the largest burden of health care spending falls on households, underutilization suggests ineffective distribution of public funds, failing to reach a significant proportion of households which are by and large poor. Interventions that improve benefit awareness may combat the problem of underutilization and should be the focus of further research in this area

Hip joint articular soft tissues of non-dinosaurian Dinosauromorpha and early Dinosauria: evolutionary and biomechanical implications for Saurischia

Dinosauromorphs evolved a wide diversity of hind limb skeletal morphologies, suggesting highly divergent articular soft tissue anatomies. However, poor preservation of articular soft tissues in fossils has hampered any follow-on functional inferences. We reconstruct the hip joint soft tissue anatomy of non-dinosaurian dinosauromorphs and early dinosaurs using osteological correlates derived from extant sauropsids and infer trends in character transitions along the theropod and sauropodomorph lineagues. Femora and pelves of 107 dinosauromorphs and outgroup taxa were digitized using 3D imaging techniques. Key transitions were estimated using maximum likelihood ancestral state reconstruction. The hips of dinosauromorphs possessed wide a disparity of soft tissue morphologies beyond the types and combinations exhibited by extant archosaurs. Early evolution of the dinosauriform hip joint was characterized by the retention of a prominent femoral hyaline cartilage cone in post-neonatal individuals, with the cartilage cone independently reduced within theropods and sauropodomorphs. The femur of Dinosauriformes possessed a fibrocartilage sleeve on the metaphysis, which surrounded a hyaline core. The acetabulum of Dinosauriformes possessed distinct labrum and antitrochanter structures. In sauropodomorphs, hip congruence was maintained by thick hyaline cartilage on the femoral head, whereas theropods relied on acetabular tissues such as ligaments and articular pads. In particular, the craniolaterally ossified hip capsule of non- Avetheropoda neotheropods permitted mostly parasagittal femoral movements. These data indicate that the dinosauromorph hip underwent mosaic evolution within the saurischian lineage and that sauropodomorphs and theropods underwent both convergence and divergence in articular soft tissues, correlated with transitions in body size, locomotor posture, and joint loading

Probabilistic population forecasts for informed decision making. Letter to the Editor.

Demographic forecasts are inherently uncertain. Nevertheless, an appropriate description of this uncertainty is a key underpinning of informed decision making. In recent decades various methods have been developed to describe the uncertainty of future populations and their structures, but the uptake of such tools amongst the practitioners of official population statistics has been lagging behind. In this letter we revisit the arguments for the practical uses of uncertainty assessments in official population forecasts, and address their implications for decision making. We discuss essential challenges, both for the forecasters and forecast users, and make recommendations for the official statistics community