205 research outputs found

    Dealing with Missing Data: A Comparative Exploration of Approaches Using the Integrated City Sustainability Database

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    Studies of governments and local organizations using survey data have played a critical role in the development of urban studies and related disciplines. However, missing data pose a daunting challenge for this research. This article seeks to raise awareness about the treatment of missing data in urban studies research by comparing and evaluating three commonly used approaches to deal with missing data—listwise deletion, single imputation, and multiple imputation. Comparative analyses illustrate the relative performance of these approaches using the second-generation Integrated City Sustainability Database (ICSD). The results demonstrate the benefit of using an approach to missing data based on multiple imputation, using a theoretically informed and statistically supported set of predictor variables to develop a more complete sample that is free of issues raised by nonresponse in survey data. The results confirm the usefulness of the ICSD in the study of environmental and sustainability and other policy in U.S. cities. We conclude with a discussion of results and provide a set of recommendations for urban researcher scholars

    Intracellular gold nanoparticles enhance non-invasive radiofrequency thermal destruction of human gastrointestinal cancer cells

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    <p>Abstract</p> <p>Background</p> <p>Novel approaches to treat human cancer that are effective with minimal toxicity profiles are needed. We evaluated gold nanoparticles (GNPs) in human hepatocellular and pancreatic cancer cells to determine: 1) absence of intrinsic cytotoxicity of the GNPs and 2) external radiofrequency (RF) field-induced heating of intracellular GNPs to produce thermal destruction of malignant cells. GNPs (5 nm diameter) were added to 2 human cancer cell lines (Panc-1, Hep3B). 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and propidium iodide-fluorescence associated cell sorting (PI-FACS) assessed cell proliferation and GNP-related cytotoxicity. Other GNP-treated cells were exposed to a 13.56 MHz RF field for 1, 2, or 5 minutes, and then incubated for 24 hours. PI-FACS measured RF-induced cytotoxicity.</p> <p>Results</p> <p>GNPs had no impact on cellular proliferation by MTT assay. PI-FACS confirmed that GNPs alone produced no cytotoxicity. A GNP dose-dependent RF-induced cytotoxicity was observed. For Hep3B cells treated with a 67 μM/L dose of GNPs, cytotoxicity at 1, 2 and 5 minutes of RF was 99.0%, 98.5%, and 99.8%. For Panc-1 cells treated at the 67 μM/L dose, cytotoxicity at 1, 2, and 5 minutes of RF was 98.5%, 98.7%, and 96.5%. Lower doses of GNPs were associated with significantly lower rates of RF-induced thermal cytotoxicity for each cell line (P < 0.01). Cells not treated with GNPs but treated with RF for identical time-points had less cytotoxicity (Hep3B: 17.6%, 21%, and 75%; Panc-1: 15.3%, 26.4%, and 39.8%, all P < 0.01).</p> <p>Conclusion</p> <p>We demonstrate that GNPs 1) have no intrinsic cytotoxicity or anti-proliferative effects in two human cancer cell lines <it>in vitro </it>and 2) GNPs release heat in a focused external RF field. This RF-induced heat release is lethal to cancer cells bearing intracellular GNPs <it>in vitro</it>.</p

    Bis(μ2-η2:η2-2,4,6-trimethyl­benzonitrile)­bis­[(N-isopropyl-3,5-dimethyl­anilido)molybdenum(III)](Mo—Mo)

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    The title compound, [Mo2(C11H16N)4(C10H11N)2], is a dinuclear molybdenum complex with a formal metal–metal bond [Mo⋯Mo separation = 2.5946 (8) Å], four anilide-type ligands and two bridging mesityl nitrile groups. There are two inversion symmetric mol­ecules in the unit cell (an inversion center is localized at the mid-point of the Mo—Mo bond), each with approximate non-crystallographic C 2h symmetry. The mol­ecules contain disordered isopropyl and 3,5-C6H3Me2 groups on different anilido ligands; the major component having an occupancy of 0.683 (7). The complex was obtained in low yield as the product from the reaction between the bridging pyrazine adduct of molybdenum tris­-anilide ([μ2-(C4H4N2){Mo(C11H16N)3}2]) and mesityl nitrile with a loss of one anilido ligand

    The Grizzly, September 23, 2004

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    Get Down in the Lounge • USGA Amendments Cause Controversy • Wismer Rumors Exposed • Family Day is Just Around the Corner • You got SERVed! • Medulla: Soul for Your Brain • Lead the Way: UC Leadership Studies Program • Care to Dance? • Opinions: Should More Public Places Move Towards a Complete No-smoking Policy?; Tattoo or not to Tattoo? • My Summer Vacation Camping at Death Pond • The Kobe Bryant Sagahttps://digitalcommons.ursinus.edu/grizzlynews/1565/thumbnail.jp

    The Lantern Vol. 75, No. 1, Fall 2007

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    • Black Cat • Divorce • The Picture in the Basement • An Ode to the \u2750s Housewife; or Go Go Sylvia Plath • Paradise from a Clock • The Fifth • Moveable Feast • Deathbed • July 17th • Words • Autobiography • The Raving • The Dream Hater • The Moon Rose Late • Tree, the Big, Very Old One in the Middle of Campus • Apple Bit • Sub Atomic Romance • God Came • Extinction • Ski Masks and Knee Caps • Of Silhouettes and Dominoeshttps://digitalcommons.ursinus.edu/lantern/1171/thumbnail.jp

    The Lantern Vol. 75, No. 2, Spring 2008

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    • In a French Courtyard at the Philadelphia Museum of Art • Picky Mangoes • And for My Un-Birthday I Drank Poets\u27 Tea and Got to See • Tree-Baby • Wrestling With Plants • I Smile • Walking Home • The Wall Between • Phalangese, or the Art of Speaking to Fingers • Early Spring • Karma Kids • A Bazaar Triptych • The Joys of Ritual Circumcision • [Of] Archetype[s] or I Don\u27t Like Your Poetry • Truth and Beauty Bombed • Chevalier Anachronistic • Kinds of Birds • Sparknotes Entry for The Changing Tide by Eric Relvas • Thirst • The Devil\u27s Dictionary • Portrait of an Artist Who Loves Icarus • Dinner at the Old House • The Meaning of a Dust-Busterhttps://digitalcommons.ursinus.edu/lantern/1172/thumbnail.jp

    Complementary shifts in photoreceptor spectral tuning unlock the full adaptive potential of ultraviolet vision in birds

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    Color vision in birds is mediated by four types of cone photoreceptors whose maximal sensitivities (λmax) are evenly spaced across the light spectrum. In the course of avian evolution, the λmax of the most shortwave-sensitive cone, SWS1, has switched between violet (λmax > 400 nm) and ultraviolet (λmax < 380 nm) multiple times. This shift of the SWS1 opsin is accompanied by a corresponding short-wavelength shift in the spectrally adjacent SWS2 cone. Here, we show that SWS2 cone spectral tuning is mediated by modulating the ratio of two apocarotenoids, galloxanthin and 11',12'-dihydrogalloxanthin, which act as intracellular spectral filters in this cell type. We propose an enzymatic pathway that mediates the differential production of these apocarotenoids in the avian retina, and we use color vision modeling to demonstrate how correlated evolution of spectral tuning is necessary to achieve even sampling of the light spectrum and thereby maintain near-optimal color discrimination

    The Lantern Vol. 73, No. 2, Spring 2006

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    • Of the Man • Beauty in America • Kindling • Genevieve • Bits of Copper • A Love Song to Hip Hop • From James\u27 Journal • I Want a Woman • Peregrine Rain • Resurge • Frustrations • (At Least) You Gave Me Something to Write About • The Fun of Giving Interactive History Lectures as a Summer Job • Exigence • White Water • My Summer, with Salt • The City With Two Faces • I Dig Your Cello • Life-Filled Ghost Town • Laura, On Happiness • Integration/Assimilation • Sunny Side Estates • Every Night I Shut My Eyes • New England State of Mind • Your Body\u27s Weight in Water for Your Soul, Thank You Very Much • A Story That\u27s 10 Percent Truehttps://digitalcommons.ursinus.edu/lantern/1168/thumbnail.jp

    Design and Rationale of Safe Pediatric Euglycemia After Cardiac Surgery (SPECS): A Randomized Controlled Trial of Tight Glycemic Control After Pediatric Cardiac Surgery

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    Objectives: To describe the design of a clinical trial testing the hypothesis that children randomized to tight glycemic control with intensive insulin therapy after cardiac surgery will have improved clinical outcomes compared to children randomized to conventional blood glucose management. Design: Two-center, randomized controlled trial. Setting: Cardiac ICUs at two large academic pediatric centers. Patients: Children from birth to those aged 36 months recovering in the cardiac ICU after surgery with cardiopulmonary bypass. Interventions: Subjects in the tight glycemic control (intervention) group receive an intravenous insulin infusion titrated to achieve normoglycemia (target blood glucose range of 80–110 mg/dL; 4.4–6.1 mmol/L). The intervention begins at admission to the cardiac ICU from the operating room and terminates when the patient is ready for discharge from the ICU. Continuous glucose monitoring is performed during insulin infusion to minimize the risks of hypoglycemia. The standard care group has no target blood glucose range. Measurements and Main Results: The primary outcome is the development of any nosocomial infection (bloodstream, urinary tract, and surgical site infection or nosocomial pneumonia). Secondary outcomes include mortality, measures of cardiorespiratory function and recovery, laboratory indices of nutritional balance, immunologic, endocrinologic, and neurologic function, cardiac ICU and hospital length of stay, and neurodevelopmental outcome at 1 and 3 yrs of age. A total of 980 subjects will be enrolled (490 in each treatment arm) for sufficient power to show a 50% reduction in the prevalence of the primary outcome. Conclusions: Pediatric cardiac surgery patients may recognize great benefit from tight glycemic control in the postoperative period, particularly with regard to reduction of nosocomial infections. The Safe Pediatric Euglycemia after Cardiac Surgery trial is designed to provide an unbiased answer to the question of whether this therapy is indeed beneficial and to define the associated risks of therapy
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