The effect of right-turn-on-red on pedestrian and bicyclist accidents

Right-Turn-on-Red (RTOR), in its “Western” version allows motorists to turn right on a red signal after stopping and yielding, unless specifically prohibited by a sign. The objective of this study was to determine the effect of Western RTOR on pedestrian and bicycle accidents in selected jurisdictions adopting the rule in the mid-1970s. The results showed significant increases in pedestrian and bicyclist accidents involving right-turning vehicles at signalized locations following the introduction of Western RTOR. These increases were: 40 % for pedestrians and 82 % for bicycles in New York State; 107 % for pedestrians and 72 % for bicycles in Wisconsin; 57 % for pedestrians and 80 % for bicycles in Ohio; and 82 % for pedestrians in New Orleans. Analysis of police accident reports suggested that drivers stopped for a red light are looking left for a gap in traffic and do not see pedestrians and bicyclists coming from their right. Countermeasure research and development was recommended to deal with this well defined problem which involves between 1 % and 3 % of all pedestrian and bicycle accidents.     

SEASONAL DEMARCATION IN PENNSYLVANIA FOR HYDROLOGICAL USE1

ABSTRACT: A study of the length of the growing and dormant season in Pennsylvania by isoline interpolation from climatological data. Maps of the beginning and ending of the growing and dormant seasons, length of growing season and ratio of growing to dormant season are included.     

Effects of cattle,sheep and deer grazing on soil physical quality and losses of phosphorus and suspended sediment losses in surface runoff

Livestock grazing and treading is strongly linked to a decrease in freshwater quality and promotes eutrophication. A two-year field trial was carried out to investigate the influence cattle, sheep and deer have on soil physical quality and the loss of phosphorus (P) and suspended sediment (SS) in surface runoff. Surface runoff plots (4 m long by 1 m wide) were installed within areas designated as stock or ungrazed (control). Surface runoff was collected and analysed for concentrations and loads of P fractions (dissolved reactive P-DRP, dissolved unreactive P-DUP, total dissolved P-TDP, particulate P-PP and total P-TP) and SS. Grazed at equivalent stocking density, soil physical samples (macroporosity, bulk density, and saturated hydraulic conductivity K_sat) were taken after each grazing event (n = 11). Soil physical data indicated differences between cattle, sheep and deer with cattle having greater negative effects. However, these differences had no impact on P and SS losses between stock types in surface runoff. Significant relationships showed that an increase in macroporosity, K_sat, and time (days) since grazing decreased concentrations and loads of P and SS losses. A separate rainfall simulation study also revealed that an increase in simulated cattle treading intensity increased the volume of surface runoff and SS losses. Most surface runoff (> 90%) occurred in winter when soil moisture was at or above field capacity. A seasonal effect was observed and showed that although the greatest P loads occurred in winter, the greatest P concentrations occurred in summer months, under infiltration-excess conditions. These summer losses could pose a risk to receiving waterways because increased light and warmth may induce an algal response compared to winter. While there is limited scope to manage for infiltration-excess surface runoff losses from pasture, with most runoff occurring in winter, these findings reinforce the use of mitigation strategies such as restricted or nil grazing in winter when soil moisture has reached field capacity to minimise P and SS loss to surface water, regardless of stock type.     

Combining geodiversity with climate and topography to account for threatened species richness

Understanding threatened species diversity is important for long‐term conservation planning. Geodiversity—the diversity of Earth surface materials, forms, and processes—may be a useful biodiversity surrogate for conservation and have conservation value itself. Geodiversity and species richness relationships have been demonstrated; establishing whether geodiversity relates to threatened species’ diversity and distribution pattern is a logical next step for conservation. We used 4 geodiversity variables (rock‐type and soil‐type richness, geomorphological diversity, and hydrological feature diversity) and 4 climatic and topographic variables to model threatened species diversity across 31 of Finland's national parks. We also analyzed rarity‐weighted richness (a measure of site complementarity) of threatened vascular plants, fungi, bryophytes, and all species combined. Our 1‐km² resolution data set included 271 threatened species from 16 major taxa. We modeled threatened species richness (raw and rarity weighted) with boosted regression trees. Climatic variables, especially the annual temperature sum above 5 °C, dominated our models, which is consistent with the critical role of temperature in this boreal environment. Geodiversity added significant explanatory power. High geodiversity values were consistently associated with high threatened species richness across taxa. The combined effect of geodiversity variables was even more pronounced in the rarity‐weighted richness analyses (except for fungi) than in those for species richness. Geodiversity measures correlated most strongly with species richness (raw and rarity weighted) of threatened vascular plants and bryophytes and were weakest for molluscs, lichens, and mammals. Although simple measures of topography improve biodiversity modeling, our results suggest that geodiversity data relating to geology, landforms, and hydrology are also worth including. This reinforces recent arguments that conserving nature's stage is an important principle in conservation.     

MR imaging of the fetal musculoskeletal system

Magnetic resonance imaging (MRI) appears to be increasingly used, in addition to standard ultrasonography for the diagnosis of abnormalities in utero. Previous studies have recently drawn attention to the technical refinement of MRI to visualize the fetal bones and muscles. Beyond commonly used T2-weighted MRI, echoplanar, thick-slab T2-weighted and dynamic sequences, and three-dimensional MRI techniques, are about to provide new imaging insights into the normal and the pathological musculoskeletal system of the fetus. This review emphasizes the potential significance of MRI in the visualization of the fetal musculoskeletal system. © 2012 John Wiley & Sons, Ltd.