1,596 research outputs found

    Coarse differentiation of quasi-isometries II: Rigidity for Sol and Lamplighter groups

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    In this paper, which is the continuation of [EFW2], we complete the proof of the quasi-isometric rigidity of Sol and the lamplighter groups. The results were announced in [EFW1].Comment: 47 pages, 3 figures. Minor revisions addressing comments by the refere

    Coarse differentiation of quasi-isometries I: spaces not quasi-isometric to Cayley graphs

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    In this paper, we prove that certain spaces are not quasi-isometric to Cayley graphs of finitely generated groups. In particular, we answer a question of Woess and prove a conjecture of Diestel and Leader by showing that certain homogeneous graphs are not quasi-isometric to a Cayley graph of a finitely generated group. This paper is the first in a sequence of papers proving results announced in [EFW0]. In particular, this paper contains many steps in the proofs of quasi-isometric rigidity of lattices in Sol and of the quasi-isometry classification of lamplighter groups. The proofs of those results are completed in [EFW1]. The method used here is based on the idea of "coarse differentiation" introduced in [EFW0].Comment: 44 pages; 4 figures; minor corrections addressing comments by the refere

    Master of Science

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    thesisResearch studies indicate that drugs of abuse are prevalent in the water system and if not properly treated, could impact the environment and future societies that use reclaimed water as a drinking source. Although they are not currently regulated by the Environmental Protection Agency (EPA), it would be beneficial for wastewater treatment facilities to begin testing for drugs of abuse to determine what concentrations are present and the facilities' removal rates. This data could be used to help the facility begin to plan for additional treatment methods when the EPA implements regulation. Most treatment facilities are government based and have limited funding. A method to detect illegal drugs in the wastewater that is cost and time effective that does not require gaining permits from the Drug Enforcement Administration (DEA) will allow municipalities to begin testing and preparing for drug removal. Detection by immuno-assay is more affordable, less time consuming and does not require permits through the DEA for drug standards as do conventional detection methods. Wastewater samples collected from Salt Lake County sewer lines and Central Valley Water Reclamation Facility were tested for caffeine, cocaine, cotinine, methamphetamine, nandrolone, oxycodone, and tetrahydrocannabinol (THC). The samples were processed and tested with Neogen Immuno-assay drug detection kits. The drugs caffeine, cocaine, methamphetamine, oxycodone, and THC were detected at concentration ranges similar to those in other studies. The concentrations for cotinine and nandrolone were undetectable. Immuno-assays proved to effectively detect drugs of abuse in wastewater

    Liver function parameters in hip fracture patients: Relations to age, adipokines, comorbidities and outcomes

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    Aim: To asses liver markers in older patients with hip fracture (HF) in relation to age, comorbidities, metabolic characteristics and short-term outcomes. Methods: In 294 patients with HF (mean age 82.0±7.9 years, 72.1% women) serum alanine aminotransferase (ALT), gammaglutamyltransferase (GGT), alkaline phosphatase (ALP), albumin, bilirubin, 25(OH)vitaminD, PTH, calcium, phosphate, magnesium, adiponectin, leptin, resistin, thyroid function and cardiac troponin I were measured. Results: Elevated ALT, GGT, ALP or bilirubin levels on admission were observed in 1.7% - 9.9% of patients. With age GGT, ALT and leptin decrease, while PTH and adiponectin concentrations increase. Higher GGT (>30U/L, median level) was associated with coronary artery disease (CAD), diabetes mellitus (DM), and alcohol overuse; lower ALT (≤20U/L, median level) with dementia; total bilirubin >20μmol/L with CAD and alcohol overuse; and albumin >33g/L with CAD. Multivariate adjusted regression analyses revealed ALT, ALP, adiponectin, alcohol overuse and DM as independent and significant determinants of GGT (as continuous or categorical variable); GGT for each other liver marker; and PTH for adiponectin. The risk of prolonged hospital stay (>20 days) was about two times higher in patients with GGT>30U/L or adiponectin >17.14 ng/L (median level) and 4.7 times higher if both conditions coexisted. The risk of in-hospital death was 3 times higher if albumin was <33g/L. Conclusions: In older HF patients liver markers even within the normal range are associated with age-related disorders and outcomes. Adiponectin (but not 25(OH)vitaminD, PTH, leptin or resistin) is an independent contributor to higher GGT. Serum GGT and albumin predict prolonged hospital stay and in-hospital death, respectively. A unifying hypothesis of the findings presented

    One-ride human powered vehicle

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    This document discusses the design, analysis, manufacturing and testing of the One-Ride human powered vehicle which was entered into the 2015 ASME West Coast HPVC Competition. The goal of the vehicle is to entice people to switch from gas powered vehicles to the One-Ride for trips of up to 20 miles round trip. The One-Ride design features fully adjustable seating and steering positions and was designed to fit anyone between the heights of 5\u272 and 6\u274 comfortably. The seat is adjusted using metal sliders, manufactured in the SCU machine shop, which fit into brackets attached to the frame. The bike features telescopic steering which is adjusted by the loosening and tightening of collar clamps. To increase the strength and safety of the frame, the welding and heat treatment were contracted to industry professionals. The frame was welded by Chavez Welding and heat treated by Byington Steel Treating. Deformation in the seat frame during heat treatment prevented full adjustability of the seat, however was secured in its middle position for testing. The wheelbase of the bike is 73.33 in and has an overall height of 50.77 in. . Slop in the steering caused instability at low speeds, which prevented the bike from being ridden in the ASME HPVC Competition. Design solutions to both of these problems have been identified. At the completion of senior design, the manufacturing is still ongoing

    Understanding patient choices for attending sexually transmitted infection testing services: a qualitative study

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    Objectives: To establish which aspects of sexually transmitted infection (STI) testing services are important to STI testing service users. Methods: 10 focus groups consisting of previous or existing users of STI testing services were conducted in community settings in the south east of England. Groups were quota sampled based on age, gender and sexual orientation. Data were analysed using Framework Analysis. Results: 65 respondents (58% men) participated. Perceived expertise of staff was the key reason for attendance at genitourinary medicine services rather than general practice. Although some respondents voiced a willingness to test for STIs within general practice, the apparent limited range of tests available in general practice and the perceived lack of expertise around sexual health appeared to discourage attendance at general practice. The decision of where to test for STIs was also influenced by past experience of testing, existing relationships with general practice, method of receiving test results and whether the patient had other medical conditions such as HIV. Conclusions: No one type of STI testing service is suitable for all patients. This is recognised by policymakers, and it now requires commissioners and providers to make services outside of genitourinary medicine clinics more acceptable and attractive to patients, in particular to address the perceived lack of expertise and limited range of STIs tests available at alternative testing sites

    Invasions, DNA barcodes, and rapid biodiversity assessment using ants of Mauritius

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    <p>Abstract</p> <p>Background</p> <p>Using an understudied taxon (Hymenoptera, Formicidae) found on a tropical island (Mauritius) where native flora and fauna have been threatened by 400 years of habitat modification and introduced species, we tested whether estimated incidences of diversity and complementarity were similar when measured by standard morphological alpha-taxonomy or phylogenetic diversity (PD) based on a standardized mitochondrial barcode and corroborating nuclear marker.</p> <p>Results</p> <p>We found that costs related to site loss (considered loss of evolutionary history measured as loss of barcode PD) were not significantly different from predictions made either a) using standard morphology-based taxonomy, or b) measured using a nuclear marker. Integrating morphology and barcode results permitted us to identify a case of initially morphologically-cryptic variation as a new and endemic candidate species. However, barcode estimates of the relative importance of each site or network of sites were dramatically affected when the species in question was known to be indigenous or introduced.</p> <p>Conclusion</p> <p>This study goes beyond a mere demonstration of the rapid gains possible for diversity assessment using a standardized DNA barcode. Contextualization of these gains with ecological and natural history information is necessary to calibrate this wealth of standardized information. Without such an integrative approach, critical opportunities to advance knowledge will be missed.</p
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