2,703 research outputs found

    Geoarchaeological Modeling of Late Paleoindian Site Location in the Northwestern Great Lakes Region

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    Full-time occupation of recently deglaciated landscapes in the northwestern Great Lakes by late Paleoindian groups marks a key milestone in the colonization of the region, yet settlement-subsistence systems of these colonizing populations remains poorly understood. Here we apply geoarchaeological modeling and early Holocene environmental reconstruction to analyze environmental settings of known late Paleoindian sites in Michigan’s Upper Peninsula. Our results reveal significant settlement patterning associated with this early Holocene record, highlighting the spatial correlation between site locations and high ground adjacent to hilly terrain and inland lakes – prime locations for monitoring the movement of large game. The analysis highlights a core area with a high likelihood for undiscovered late Paleoindian sites in the northwest corner of Marquette County and suggests the possibility of a north-south travel corridor into the region from upper Wisconsin along the Michigamme River

    Solar Carbon Monoxide, Thermal Profiling, and the Abundances of C, O, and their Isotopes

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    A solar photospheric "thermal profiling" analysis is presented, exploiting the infrared rovibrational bands of carbon monoxide (CO) as observed with the McMath-Pierce Fourier transform spectrometer (FTS) at Kitt Peak, and from above the Earth's atmosphere by the Shuttle-borne ATMOS experiment. Visible continuum intensities and center-limb behavior constrained the temperature profile of the deep photosphere, while CO center-limb behavior defined the thermal structure at higher altitudes. The oxygen abundance was self consistently determined from weak CO absorptions. Our analysis was meant to complement recent studies based on 3-D convection models which, among other things, have revised the historical solar oxygen (and carbon) abundance downward by a factor of nearly two; although in fact our conclusions do not support such a revision. Based on various considerations, an oxygen abundance of 700+/-100 ppm (parts per million relative to hydrogen) is recommended; the large uncertainty reflects the model sensitivity of CO. New solar isotopic ratios also are reported for 13C, 17O, and 18O.Comment: 90 pages, 19 figures (some with parts "a", "b", etc.); to be published in the Astrophysical Journal Supplement

    Aquatic treadmill running reduces muscle soreness following intense sprint exercise in trained men

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    Delayed onset muscle soreness is associated with muscle damage, disturbances in proprioception, and decreases in muscular power. The purpose was to determine if short duration aquatic treadmill (ATM) running reduces muscle soreness following intense sprint exercise in trained men. Twenty trained men (180.3±4.4cm, 86.3±5.8kg, 20±1yr) were recruited and randomly divided into two groups: ATM recovery (ATMRec) and passive recovery (PRec). During testing, subjects performed a warm-up followed by sixteen 110yrd cutback runs with a sprint of 60yrds, sharp change of direction, and a return sprint of 50yrds. Work to rest ratio was set at 1:3. Additionally, following exercise, the ATMRec group performed ATM running using a HydroWorx® treadmill at 5mph, 50% maximal jet resistance, and water(33°C) level at chest depth for 10min. Both groups then evaluated their level of soreness/pain using a numerical rating scale (NRS: 0-10, 0=no pain, 10=worst pain) immediately following all exercise (IPE), 24h, and 48h post exercise in the following regions: ARMS, LEGS, BACK, CHEST, SHOULDERS, HIPS, ABDOMEN, NECK, OVERALL. Data were analyzed for group x time interactions using a 2x3 Generalized Linear Mixed Model for non-parametric data (α≤0.05). For significant interactions, the same procedure was used to analyze between group differences at the same measurement timepoint(α≤0.05)

    Leak detection and calibration using transients and genetic algorithms

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    Leak detection and calibration of pipe internal roughnesses in a water network are significant issues for water authorities around the world. Computer simulation of water distribution systems to determine the location and size of leaks is emerging as an important tool. A major uncertainty in developing computer models is the condition of the interior of the pipes in the network, especially if they are old. An innovative technique for leak detection and calibration called the inverse transient technique has been recently developed. This paper uses the genetic algorithm (GA) technique in conjunction with the inverse transient method to detect leaks and friction factors in water distribution systems. A continuous variable representation has been developed for the GA coding scheme in this paper. Two new GA operators for crossover and mutation are also introduced. The inverse transient method using the GA technique is effective at finding leakage locations and magnitudes while simultaneously finding the friction factors for different transient data record lengths.John P. Vítkovský, Angus R.Simpson and Martin F. Lamber

    Carrageenan Is a Potent Inhibitor of Papillomavirus Infection

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    Certain sexually transmitted human papillomavirus (HPV) types are causally associated with the development of cervical cancer. Our recent development of high-titer HPV pseudoviruses has made it possible to perform high-throughput in vitro screens to identify HPV infection inhibitors. Comparison of a variety of compounds revealed that carrageenan, a type of sulfated polysaccharide extracted from red algae, is an extremely potent infection inhibitor for a broad range of sexually transmitted HPVs. Although carrageenan can inhibit herpes simplex viruses and some strains of HIV in vitro, genital HPVs are about a thousand-fold more susceptible, with 50% inhibitory doses in the low ng/ml range. Carrageenan acts primarily by preventing the binding of HPV virions to cells. This finding is consistent with the fact that carrageenan resembles heparan sulfate, an HPV cell-attachment factor. However, carrageenan is three orders of magnitude more potent than heparin, a form of cell-free heparan sulfate that has been regarded as a highly effective model HPV inhibitor. Carrageenan can also block HPV infection through a second, postattachment heparan sulfate–independent effect. Carrageenan is in widespread commercial use as a thickener in a variety of cosmetic and food products, ranging from sexual lubricants to infant feeding formulas. Some of these products block HPV infectivity in vitro, even when diluted a million-fold. Clinical trials are needed to determine whether carrageenan-based products are effective as topical microbicides against genital HPVs

    Leak detection in pipelines using the damping of fluid transients

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    © 2002 American Society of Civil EngineersLeaks in pipelines contribute to damping of transient events. That fact leads to a method of finding location and magnitude of leaks. Because the problem of transient flow in pipes is nearly linear, the solution of the governing equations can be expressed in terms of a Fourier series. All Fourier components are damped uniformly by steady pipe friction, but each component is damped differently in the presence of a leak. Thus, overall leak-induced damping can be divided into two parts. The magnitude of the damping indicates the size of a leak, whereas different damping ratios of the various Fourier components are used to find the location of a leak. This method does not require rigorous determination and modeling of boundary conditions and transient behavior in the pipeline. The technique is successful in detecting, locating, and quantifying a 0.1% size leak with respect to the cross-sectional area of a pipeline.Xiao-Jian Wang, Martin F. Lambert, Angus R. Simpson, James A. Liggett, and John P. Vitkovsk

    Pipeline break detection using pressure transient monitoring

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    Sudden pipe breaks occur in water transmission pipelines and distribution mains. The consequences of these breaks can be very expensive because of the service interruption, the cost of repair, and damage to surrounding property and infrastructure. The costs associated with the pipeline breaks can be reduced by minimizing the break detection and location time. This paper presents a new continuous monitoring approach for detecting and locating breaks in pipelines. A sudden pipe break creates a negative pressure wave that travels in both directions away from the break point and is reflected at the pipeline boundaries. Using the pressure data measured at one location along the pipeline, the timing of the initial and reflected transient waves induced by the break determines the location of the break. The magnitude of the transient wave provides an estimate of the break size. The continuous monitoring technique uses a modified two-sided cumulative sum (CUSUM) algorithm to detect abrupt break-induced changes in the pressure data. The adaptive tuning of CUSUM parameters is implemented to detect breaks of differing sizes and opening times. The continuous monitoring technique is verified by using results from both laboratory and field experiments and shows potential for detecting and locating sudden breaks in real pipelines.Dalius Misiunas, John Vítkovský, Gustaf Olsson, Angus Simpson, M.ASCE, and Martin Lambert

    Patterns of primary care and mortality among patients with schizophrenia or diabetes: a cluster analysis approach to the retrospective study of healthcare utilization

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    Abstract Background Patients with schizophrenia have difficulty managing their medical healthcare needs, possibly resulting in delayed treatment and poor outcomes. We analyzed whether patients reduced primary care use over time, differentially by diagnosis with schizophrenia, diabetes, or both schizophrenia and diabetes. We also assessed whether such patterns of primary care use were a significant predictor of mortality over a 4-year period. Methods The Veterans Healthcare Administration (VA) is the largest integrated healthcare system in the United States. Administrative extracts of the VA's all-electronic medical records were studied. Patients over age 50 and diagnosed with schizophrenia in 2002 were age-matched 1:4 to diabetes patients. All patients were followed through 2005. Cluster analysis explored trajectories of primary care use. Proportional hazards regression modelled the impact of these primary care utilization trajectories on survival, controlling for demographic and clinical covariates. Results Patients comprised three diagnostic groups: diabetes only (n = 188,332), schizophrenia only (n = 40,109), and schizophrenia with diabetes (Scz-DM, n = 13,025). Cluster analysis revealed four distinct trajectories of primary care use: consistent over time, increasing over time, high and decreasing, low and decreasing. Patients with schizophrenia only were likely to have low-decreasing use (73% schizophrenia-only vs 54% Scz-DM vs 52% diabetes). Increasing use was least common among schizophrenia patients (4% vs 8% Scz-DM vs 7% diabetes) and was associated with improved survival. Low-decreasing primary care, compared to consistent use, was associated with shorter survival controlling for demographics and case-mix. The observational study was limited by reliance on administrative data. Conclusion Regular primary care and high levels of primary care were associated with better survival for patients with chronic illness, whether psychiatric or medical. For schizophrenia patients, with or without comorbid diabetes, primary care offers a survival benefit, suggesting that innovations in treatment retention targeting at-risk groups can offer significant promise of improving outcomes.http://deepblue.lib.umich.edu/bitstream/2027.42/78274/1/1472-6963-9-127.xmlhttp://deepblue.lib.umich.edu/bitstream/2027.42/78274/2/1472-6963-9-127.pdfPeer Reviewe
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