379 research outputs found

    Master of Science

    Get PDF
    thesisA research study was conducted for the Utah Department of Transportation regarding settlement caused by embankment construction for a new bridge located about V mile east of the Interstate 15-State Route 77 interchange in Springville, Utah. Embankment ramps were about 425-ft long, 106-ft wide, and 30-ft tall at the highest points, with vertical side slopes supported by mechanically stabilized earth (MSE) walls. The primary objectives of this study were as follows: (1) Determine consolidation properties of the cohesive soils; (2) predict time rate of primary consolidation settlement using numerical analyses; (3) compare measured rates of primary consolidation settlement with predicted values; and (4) compare the effectiveness of Asaoka's (1978) method for predicting the time for surcharge removal with more advanced methods. These objectives were attained by performing field and laboratory investigations to determine properties of the soils at the site, installing instrumentation to measure settlement and other relevant parameters, and performing numerical analyses to predict the rate of primary consolidation settlement within each cohesive layer. During the field investigation, undisturbed piston samples were obtained and standard penetration, cone penetration, and vane shear tests were performed. Instruments installed to monitor soil behavior included nineteen piezometers, twenty spider magnets, six settlement manometers, three push-in cells, two ShapeAccelArrays, one vertical inclinometer, one horizontal inclinometer, three pressure cells for vertical stress, and three pressure cells for horizontal stress. The laboratory investigation included classification and constant rate of strain consolidation tests. Primary consolidation settlement was predicted using Terzaghi's (1947) and Davis and Raymond's (1965) one-dimensional consolidation theories in conjunction with the finite difference method. Results from these two analyses were compared with measured primary consolidation settlement data obtained from field instruments. Primary consolidation settlement results using both methods proved to be reasonable, but no conclusion could be reached regarding which method yielded better predictions. Predicted times for surcharge removal analyzed using Asaoka's method based on measured values of surface settlement were incorrect because of the erroneous assumption that the underlying soil is homogenous. Better estimates of time for surcharge removal were obtained by analyzing each of the cohesive layers separately

    Lymphatic vasculature mediates macrophage reverse cholesterol transport in mice

    Get PDF
    Reverse cholesterol transport (RCT) refers to the mobilization of cholesterol on HDL particles (HDL-C) from extravascular tissues to plasma, ultimately for fecal excretion. Little is known about how HDL-C leaves peripheral tissues to reach plasma. We first used 2 models of disrupted lymphatic drainage from skin — 1 surgical and the other genetic — to quantitatively track RCT following injection of [3H]-cholesterol–loaded macrophages upstream of blocked or absent lymphatic vessels. Macrophage RCT was markedly impaired in both models, even at sites with a leaky vasculature. Inhibited RCT was downstream of cholesterol efflux from macrophages, since macrophage efflux of a fluorescent cholesterol analog (BODIPY-cholesterol) was not altered by impaired lymphatic drainage. We next addressed whether RCT was mediated by lymphatic vessels from the aortic wall by loading the aortae of donor atherosclerotic Apoe-deficient mice with [2H]6-labeled cholesterol and surgically transplanting these aortae into recipient Apoe-deficient mice that were treated with anti-VEGFR3 antibody to block lymphatic regrowth or with control antibody to allow such regrowth. [2H]-Cholesterol was retained in aortae of anti–VEGFR3-treated mice. Thus, the lymphatic vessel route is critical for RCT from multiple tissues, including the aortic wall. These results suggest that supporting lymphatic transport function may facilitate cholesterol clearance in therapies aimed at reversing atherosclerosis

    Robotic Thumb Assembly

    Get PDF
    An improved robotic thumb for a robotic hand assembly is provided. According to one aspect of the disclosure, improved tendon routing in the robotic thumb provides control of four degrees of freedom with only five tendons. According to another aspect of the disclosure, one of the five degrees of freedom of a human thumb is replaced in the robotic thumb with a permanent twist in the shape of a phalange. According to yet another aspect of the disclosure, a position sensor includes a magnet having two portions shaped as circle segments with different center points. The magnet provides a linearized output from a Hall effect sensor

    A parsimonious explanation for intersecting perinatal mortality curves: understanding the effects of race and of maternal smoking

    Get PDF
    BACKGROUND: Neonatal mortality rates among black infants are lower than neonatal mortality rates among white infants at birth weights <3000 g, whereas white infants have a survival advantage at higher birth weights. This finding is also observed when birth weight-specific neonatal mortality rates are compared between infants of smokers and non-smokers. We provide a parsimonious explanation for this paradoxical phenomenon. METHODS: We used data on births in the United States in 1997 after excluding those with a birth weight <500 g or a gestational age <22 weeks. Birth weight- and gestational age-specific perinatal mortality rates were calculated per convention (using total live births at each birth weight/gestational age as the denominator) and also using the fetuses at risk of death at each gestational age. RESULTS: Perinatal mortality rates (calculated per convention) were lower among blacks than whites at lower birth weights and at preterm gestational ages, while blacks had higher mortality rates at higher birth weights and later gestational ages. With the fetuses-at-risk approach, mortality curves did not intersect; blacks had higher mortality rates at all gestational ages. Increases in birth rates and (especially) growth-restriction rates presaged gestational age-dependent increases in perinatal mortality. Similar findings were obtained in comparisons of smokers versus nonsmokers. CONCLUSIONS: Formulating perinatal risk based on the fetuses-at-risk approach solves the intersecting perinatal mortality curves paradox; blacks have higher perinatal mortality rates than whites and smokers have higher perinatal mortality rates than nonsmokers at all gestational ages and birth weights

    Phytoplankton phenology indices in coral reef ecosystems : application to ocean-color observations in the Red Sea

    Get PDF
    © The Author(s), 2015. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Remote Sensing of Environment 160 (2015): 222-234, doi:10.1016/j.rse.2015.01.019.Phytoplankton, at the base of the marine food web, represent a fundamental food source in coral reef ecosystems. The timing (phenology) and magnitude of the phytoplankton biomass are major determinants of trophic interactions. The Red Sea is one of the warmest and most saline basins in the world, characterized by an arid tropical climate regulated by the monsoon. These extreme conditions are particularly challenging for marine life. Phytoplankton phenological indices provide objective and quantitative metrics to characterize phytoplankton seasonality. The indices i.e. timings of initiation, peak, termination and duration are estimated here using 15 years (1997–2012) of remote sensing ocean-color data from the European Space Agency (ESA) Climate Change Initiative project (OC-CCI) in the entire Red Sea basin. The OC-CCI product, comprising merged and bias-corrected observations from three independent ocean-color sensors (SeaWiFS, MODIS and MERIS), and processed using the POLYMER algorithm (MERIS period), shows a significant increase in chlorophyll data coverage, especially in the southern Red Sea during the months of summer NW monsoon. In open and reef-bound coastal waters, the performance of OC-CCI chlorophyll data is shown to be comparable with the performance of other standard chlorophyll products for the global oceans. These features have permitted us to investigate phytoplankton phenology in the entire Red Sea basin, and during both winter SE monsoon and summer NW monsoon periods. The phenological indices are estimated in the four open water provinces of the basin, and further examined at six coral reef complexes of particular socio-economic importance in the Red Sea, including Siyal Islands, Sharm El Sheikh, Al Wajh bank, Thuwal reefs, Al Lith reefs and Farasan Islands. Most of the open and deeper waters of the basin show an apparent higher chlorophyll concentration and longer duration of phytoplankton growth during the winter period (relative to the summer phytoplankton growth period). In contrast, most of the reef-bound coastal waters display equal or higher peak chlorophyll concentrations and equal or longer duration of phytoplankton growth during the summer period (relative to the winter phytoplankton growth period). The ecological and biological significance of the phytoplankton seasonal characteristics are discussed in context of ecosystem state assessment, and particularly to support further understanding of the structure and functioning of coral reef ecosystems in the Red Sea

    International Comparison of Approaches to Common Data Models for Comparative Effectiveness Research

    Get PDF
    Over the past decade, characterizing the safety and effectiveness of drugs has advanced through distributed networks of data repositories where investigators implement the same procedures to address the same topic using a common data model. Distributed networks for pharmacoepidemiology have now been established in the United States (US), Globally/Europe Canada, and Asian countries. Sentinel in the US was developed in response to legislation and is funded by the US Food and Drug Administration to address their safety queries. The Observational Medical Outcomes Partnership (OMOP) is an international collaborative with a growing European data network that developed a common data model through a public-private partnership. The Canadian Network of Observational Drug Effect Studies (CNODES) receives funding and study queries from Health Canada and dissemination is directly back to the regulator as well as through the peer-reviewed literature. The Asian Pharmacoepidemiology Network (AsPEN) is an investigator-initiated multi-national research network formed to support the safety and effectiveness assessment of medications and other therapeutics and to facilitate the prompt identification and validation of emerging safety issues among the countries in Asia and Pacific regions. While these networks have implemented two different common data models (CNODES with Sentinel, ASPEN with OMOP), each network differs from the others in the aims, stage and implementation, operational approach, data quality assurance mechanisms, funding, and dissemination. The objectives of this session are to compare and contrast the role and goals, design principles, implementation approaches, and analytic conventions and procedures between common data models implemented by SENTINEL, OMOP, CNODES, ands AsPEN. Divided into seven 15-minute segments the session begins with an overview of distributed networks of common data models for pharmacoepidemiology. In four slides, each presenter then characterizes their network by describing the following: • number of data holders, lives covered, and records, data holdings, data access model, network governance. • process for transforming a repository’s data into the common data model • target audience(s), process of identifying queries and knowledge dissemination plan • two key challenges faced by the network and the lessons learned In identifying similarities and meaningful differences between the networks, in the next segment the discussant will articulate the relative strengths of the different approaches taken. This will lead into the last segment in which the floor will be opened for questions and comments from the audience. The session would be of benefit to researchers seeking to better understand or join an existing distributed network as well as researchers interested in broadening their understanding of global comparative effectiveness research

    Robotic Finger Assembly

    Get PDF
    A robotic hand includes a finger with first, second, and third phalanges. A first joint rotatably connects the first phalange to a base structure. A second joint rotatably connects the first phalange to the second phalange. A third joint rotatably connects the third phalange to the second phalange. The second joint and the third joint are kinematically linked such that the position of the third phalange with respect to the second phalange is determined by the position of the second phalange with respect to the first phalange

    Safety and efficacy of botox injection in alleviating post-operative pain and improving quality of life in lower extremity limb lengthening and deformity correction

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Distraction osteogenesis is the standard treatment for the management of lower limb length discrepancy of more than 3 cm and bone loss secondary to congenital anomalies, trauma or infection. This technique consists of an osteotomy of the bone to be lengthened, application of an external fixator, followed by gradual and controlled distraction of the bone ends. Although limb lengthening using the Ilizarov distraction osteogenesis principle yields excellent results in most cases, the technique has numerous problems and is not well tolerated by many children. The objective of the current study is to determine if Botulinum Toxin A (BTX-A), which is known to possess both analgesic and paralytic actions, can be used to alleviate post-operative pain and improve the functional outcome of children undergoing distraction osteogenesis.</p> <p>Methods/Design</p> <p>The study design consists of a multi centre, randomized, double-blinded, placebo-controlled trial. Patients between ages 5–21 years requiring limb lengthening or deformity correction using distraction will be recruited from 6 different sites (Shriners Hospital for Children in Montreal, Honolulu, Philadelphia and Portland as well as DuPont Hospital for Children in Wilmington, Delaware and Hospital for Sick Children in Toronto, Ont). Approximately 150 subjects will be recruited over 2 years and will be randomized to either receive 10 units per Kg of BTX-A or normal saline (control group) intraoperatively following the surgery. Functional outcome effects will be assessed using pain scores, medication dosages, range of motion, flexibility, strength, mobility function and quality of life of the patient. IRB approval was obtained from all sites and adverse reactions will be monitored vigorously and reported to IRB, FDA and Health Canada.</p> <p>Discussion</p> <p>BTX-A injection has been widely used world wide with no major side effects reported. However, to the best of our knowledge, this is the first time BTX-A is being used under the context of limb lengthening and deformity correction.</p> <p>Trial Registration</p> <p>NCT00412035</p

    Robotic Finger Assembly

    Get PDF
    A robotic hand includes a finger with first, second, and third phalanges. A first joint rotatably connects the first phalange to a base structure. A second joint rotatably connects the first phalange to the second phalange. A third joint rotatably connects the third phalange to the second phalange. The second joint and the third joint are kinematically linked such that the position of the third phalange with respect to the second phalange is determined by the position of the second phalange with respect to the first phalange
    corecore