91 research outputs found

    The Role of Childhood Asthma in Obesity Development

    Get PDF
    RATIONALE: Asthma and obesity often co-occur. It has been hypothesized that asthma may contribute to childhood obesity onset. OBJECTIVES: To determine if childhood asthma is associated with incident obesity and examine the role of asthma medication in this association. METHODS: We studied 8,716 children between ages 6 and 18.5 years who were nonobese at study entry participating in 18 US cohorts of the Environmental influences on Child Health Outcomes program (among 7,299 children with complete covariate data mean [SD] study entry age = 7.2 [1.6] years and follow up = 5.3 [3.1] years). MEASUREMENTS AND MAIN RESULTS: We defined asthma based on caregiver report of provider diagnosis. Incident obesity was defined as the first documented body mass index ≥95th percentile for age and sex following asthma status ascertainment. Over the study period, 26% of children had an asthma diagnosis and 11% developed obesity. Cox proportional hazards models with sex-specific baseline hazards were fitted to assess the association of asthma diagnosis with obesity incidence. Children with asthma had a 23% (95% confidence intervals [CI] = 4, 44) higher risk for subsequently developing obesity compared with those without asthma. A novel mediation analysis was also conducted to decompose the total asthma effect on obesity into pathways mediated and not mediated by asthma medication use. Use of asthma medication attenuated the total estimated effect of asthma on obesity by 64% (excess hazard ratios = 0.64; 95% CI = -1.05, -0.23). CONCLUSIONS: This nationwide study supports the hypothesis that childhood asthma is associated with later risk of obesity. Asthma medication may reduce this association and merits further investigation as a potential strategy for obesity prevention among children with asthma

    Materials produced from plant biomass: part II: evaluation of crystallinity and degradation kinetics of cellulose

    Get PDF
    In this study Eucalyptus grandis (CEG) and Pinus taeda (CPT) cellulose fibers obtained from kraft and sulfite pulping process, respectively, were characterized using Fourier transform infrared (FTIR) spectroscopy and thermogravimetry (TGA). The degradation kinetic parameters were determined by TGA using Coats and Redfern method. FTIR results showed that CPT presented a more ordered structure with higher crystallinity than CEG. Thermogravimetric results showed that CPT had a higher thermal stability than CEG. The kinetic results revel that for CEG the degradation mechanism occurs mainly by random nucleation, although phase boundary controlled reactions also occurs while for CPT the degradation process is more related with phase boundary controlled reactions. Results demonstrated that differences between thermal stability and degradation mechanisms might be associated with differences in the cellulose crystalline structure probably caused by different pulping processes used for obtaining the cellulose fibers

    Sodium Concentrations In Water From The Piney Point Formation, Dover Area, Delaware

    No full text
    In the greater Dover area sodium concentrations in ground water from the glauconitic Piney Point Formation commonly exceed 100 parts per million. Investigation of chemical characteristics of the water, and statistical analyses of the results, show that these high concentrations are due to a natural ion-exchange process. Calcium in water replaces sodium in the mineral glauconite and causes the sodium enrichment in ground water

    Geologic Aspects Of Disposal Of Highly Radioactive Nuclear Waste

    No full text
    This report was prepared to provide a simple but comprehensive overview of programs and concepts of highly radioactive waste disposal. This report is not based on original research, but was prepared from data and information reported in voluminous publications of the U.S. Department of Energy, the Nuclear Regulatory Commission, the U.S. Environmental Protection Agency, and the U.S. Geological Survey

    Landsat View of Delaware

    No full text
    In Delaware some linear features recognized on the Landsat image can be related to known faults. Others are interpreted as possible faults; the causes of some lineations are not yet known. Circular features are more difficult to interpret but they are similar to the domal structures and erosional features recognized in the Gulf Coast region, for example. These and the linear features of uncertain origin can be investigated by drilling and geophysical techniques after being localized by clues provided by the satellite images. Detection by satellite images and confirmation by other geologic techniques is an efficient and effective means of geologic investigation

    Exploring, Drilling, And Producing Petroleum Offshore

    No full text
    This report was prepared to provide a concise description of offshore operations related to exploration for petroleum (oil and natural gas) from the initial geologic and geophysical investigations to production. Petroleum deposits differ in their physical and chemical properties and are associated in the rocks with saline water. The origin of petroleum and its migration through rocks are not well understood. Commercial accumulations are found in certain suitable rocks or geologic structures - stratigraphic and structural traps, respectively. Prospective areas offshore are leased to exploration companies by the federal government. Exploration begins with geological and geophysical investigations that lead to the selection of smaller, promising areas. Detailed studies and drilling are then carried out and, if petroleum is found, various tests are performed to determine the volume of oil or gas or both. If the quantities are large, production facilities are designed and located on the site. The petroleum produced is transported to refining facilities or gas companies onshore by pipelines or tankers. Experience has shown that large, damaging oil spills are very rare. The most common cause of spills is marine transportation

    Geology Of The Fall Zone In Delaware

    No full text
    The complex geologic framework of the Fall Zone in Delaware is primarily caused by diverse structural features present in the crystalline basement rocks that have exerted a considerable influence on the distribution of the overlying sediments of the Coastal Plain.Water Resources Center, University of Delaware, Newark, Delawar

    Pleistocene Channels Of New Castle County, Delaware

    No full text
    Two Pleistocene channel-systems are recognized in New Castle County, (1) a system of straight channels located in the area north of the Chesapeake and Delaware Canal and (2) a braided system occupying the area south of the Canal. Fluctuations of the flow regime of Pleistocene streams were frequent as evidenced by sedimentary structures and widespread distribution of gravels in the channel deposits. During high stream flows most of the study area was submerged, while during low flows large interstream areas and islands emerged. The transporting agents of the Pleistocene sediments were primarily melt-water streams originating below glaciers which at times advanced to within 100 miles north of New Castle County. Thus, the age of the deposits is thought to be glacial, but there is no indication as to which glacial stage they belong. However, the channels appear to have been formed contemporaneously by a major distributary system

    Clay And Clay-Size Mineral Composition Of The Cretaceous-Tertiary Section, Test Well Je32-04, Central Delaware

    No full text
    This report has 2 plates.This study complements Delaware Geological Survey Bulletin No. 17 and deals exclusively with clays and clay-size minerals. The cored section at the location of Je32-04 has been subdivided into 25 clay zones on the basis of major changes in trends and degree of crystallinity of clay minerals. The composition of clay minerals varies from zone to zone. These clay minerals have been identified: kaolinite, berthierine, chlorite, illite, smectite, chlorite/smectite, illite/smectite, glauconite/smectite, and glauconite pellets. Other minerals present in the section include: zeolites (clinoptilolite-heulandite), gypsum, and elemental sulfur
    corecore