Where do Children Travel to and What Local Opportunities Are Available? The Relationship Between Neighborhood Destinations and Children’s Independent Mobility

Associations between access to local destinations and children’s independent mobility (IM) were examined. In 2007, 10- to 12-year-olds (n = 1,480) and their parents (n = 1,314) completed a survey. Children marked on a map the destinations they walked or cycled to (n = 1,132), and the availability of local destinations was assessed using Geographic Information Systems. More independently mobile children traveled to local destinations than other children. The odds of IM more than halved in both boys and girls whose parents reported living on a busy road (boys, OR = 0.48; girls, OR = 0.36) and in boys who lived near shopping centers (OR = 0.18) or community services (OR = 0.25). Conversely, the odds of IM more than doubled in girls living in neighborhoods with well-connected low-traffic streets (OR = 2.32) and increased in boys with access to local recreational (OR = 1.67) and retail (OR = 1.42) destinations. Creating safe and accessible places and routes may facilitate children’s IM, partly by shaping parent’s and children’s feelings of safety while enhancing their confidence in the child’s ability to use active modes without an adult

Improving Low-Relief Coastal LiDAR DEMs with Hydro-Conditioning of Fine-Scale and Artificial Drainages

Improvements in Light Detection and Ranging (LiDAR) technology and spatial analysis of high-resolution digital elevation models (DEMs) have advanced the accuracy and diversity of applications for coastal hazards and natural resources management. This article presents a concise synthesis of LiDAR analysis for coastal flooding and management applications in low-relief coastal plains and a case study demonstration of a new, efficient drainage mapping algorithm. The impetus for these LiDAR applications follows historic flooding from Hurricane Floyd in 1999, after which the State of North Carolina and the Federal Emergency Management Agency (FEMA) undertook extensive LiDAR data acquisition and technological developments for high-resolution floodplain mapping. An efficient algorithm is outlined for hydro-conditioning bare earth (BE) LiDAR DEMs using available US Geological Survey1 National Hydrography Dataset (NHD) canal and ditch vectors. The methodology is illustrated in Moyock, North Carolina, for refinement of hydro-conditioning by combining pre-existing BE DEMs with spatial analysis of LiDAR point clouds in segmented and buffered ditch and canal networks. The methodology produces improved maps of fine-scale drainage, reduced omission of areal flood inundation, and subwatershed delineations that typify heavily ditched and canalled drainage areas. These preliminary results illustrate the capability of the technique to improve the representation of ditches in DEMs as well as subsequent flow and inundation modeling that could spur further research on low-relief coastal LiDAR applications.ECU Open Access Publishing Support Fun

Long-distance dispersal explains the bipolar disjunction in Carex macloviana

PREMISE OF THE STUDY: The sedge Carex macloviana d’Urv presents a bipolar distribution. To clarify the origin of its distribution, we consider the four main hypotheses: long-distance dispersal (either by mountain hopping or by direct dispersal), vicariance, parallel evolution, and human introduction. METHODS: Phylogenetic, phylogeographic, and divergence time estimation analyses were carried out based on two nuclear ribosomal (ETS and ITS) regions, one nuclear single copy gene (CATP), and three plastid DNA regions (rps 16 and 5′ trn K introns, and psb A-trn H spacer), using Bayesian inference, maximum likelihood, and statistical parsimony. Bioclimatic data were used to characterize the climatic niche of C. macloviana. KEY RESULTS: C arex macloviana constitutes a paraphyletic species, dating back to the Pleistocene (0.62 Mya, 95% highest posterior density: 0.29–1.00 Mya). This species displays strong genetic structure between hemispheres, wiThtwo different lineages in the Southern Hemisphere and limited genetic differentiation in Northern Hemisphere populations. Also, populations from the Southern Hemisphere show a narrower climatic niche wiThregards to the Northern Hemisphere populations. CONCLUSIONS: C arex macloviana reached its bipolar distribution by long-distance dispersal, although it was not possible to determine whether it was caused by mountain hopping or by direct dispersal. While there is some support that Carex macloviana might have colonized the Northern Hemisphere by south-to-norThtranshemisphere dispersal during the Pleistocene, unlike the southwards dispersal pattern inferred for other bipolar Carex L. species, we cannot entirely rule out north-to-souThdispersion.Ministerio de Economía y Competitividad CGL2016-77401-