500 research outputs found

    An interdisciplinary study of the estuarine and coastal oceanography of Block Island Sound and adjacent New York coastal waters

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    The author has identified the following significant results. Photo-optical additive color quantitative measurements were made of ERTS-1 reprocessed positives of New York Bight and Block Island Sound. Regression of these data on almost simultaneous ship sample data of water's physical, chemical, biological, and optical properties showed that ERTS bands 5 and 6 can be used to predict the absolute value of the total number of particles and bands 4 and 5 to predict the relative extinction coefficient in New York Bight. Water masses and mixing patterns in Block Island Sound heretofore considered transient were found to be persistent phenomena requiring revision of existing mathematical and hydraulic models

    Lying, Cheating, & Stealing: Strategies for Mitigating Technology-Driven Academic Dishonesty in Collegiate Schools of Business

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    We summarize contemporary issues related to academic dishonesty and draw from relevant organizational ethics program research to present a dual framework that business educators can use to mitigate technology-driven cheating among their students. Based on a review of the relevant literature, we develop a rationale which identifies three key observations: 1) technology-driven academic dishonesty is pervasive among college business students, 2) there are proactive steps that can be taken to address this problem, and 3) faculty, staff, and administrators in collegiate schools of business can and should do more to mitigate cheating among their students. We first provide an overview concerning the evolution of academic dishonesty and the technological advances that simplify cheating. Next, we propose a conceptual framework and list recommendations for business educators, using both compliance-based and values-based strategies, to reduce the frequency and severity of cheating

    W/M serrated osteotomy for infantile Blount’s disease in Ghana: Short‑term results

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    Purpose: The W/M serrated high tibial osteotomy is a not frequently described surgical technique for simultaneously correcting the varus and torsional deformity in patients with Blount’s disease. Without the need for internal fixation, this surgical treatment is well suited for developing countries. This study describes the short‑term results of the bilateral and unilateral W/M serrated osteotomy in patients with infantile Blount’s disease.Methods: Between May 2008 and January 2013, 52 patients were treated with uni‑ (n = 22) or bi‑lateral (n = 30) W/M serrated osteotomy of the proximal tibia due to a tibial varus deformity in two district hospitals in Ghana. Other causes than infantile Blount’s disease were excluded from the analysis. Pre‑ and post‑operative clinical and radiological measurements were done, and complications were monitored up to 12 weeks after surgery.Results: Seventeen patients (five males, 12 females; mean age 4.9 [standard deviation: 2.10]) were included, which underwent a total of 25 W/M serrated osteotomies. The femorotibial angle was corrected from 34.1° ([mean] range: 6 68°) to − 7.1° ([mean] range: −28–5°). Only one patient had developed a wound infection, and all reached full consolidation.Conclusions: The W/M serrated osteotomy seems a profitable alternative technique for treating the varus and torsional deformity in patients with Blount’s disease in the circumstances of developing countries. The short‑term outcomes are good and promising with a low complication rate and good consolidation. Long‑term follow‑up results of these patients are needed to observe possible complications.Level of Evidence: IV, therapeutic case series.Keywords: Blount’s disease, complications, infantile, osteotomy, tibia var

    Hypoxia-inducible factor-1 (HIF-1) pathway activation by quercetin in human lens epithelial cells

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    Quercetin is a dietary bioflavonoid which has been shown to inhibit lens opacification in a number of models of cataract. The objectives of this study were to determine gene expression changes in human lens epithelial cells in response to quercetin and to investigate in detail the mechanisms underlying the responses. FHL-124 cells were treated with quercetin (10 µM) and changes in gene expression were measured by microarray. It was found that 65% of the genes with increased expression were regulated by the hypoxia-inducible factor-1 (HIF-1) pathway. Quercetin (10 and 30 µM) induced a time-dependent increase in HIF-1a protein levels. Quercetin (30 µM) was also responsible for a rapid and long-lasting translocation of HIF-1a from the cytoplasm to the nucleus. Activation of HIF-1 signaling by quercetin was confirmed by qRT–PCR which showed upregulation of the HIF-1 regulated genes EPO, VEGF, PGK1 and BNIP3. Analysis of medium taken from FHL-124 cells showed a sustained dose-dependent increase in VEGF secretion following quercetin treatment. The quercetin-induced increase and nuclear translocation of HIF-1a was reversed by addition of excess iron (100 µM). These results demonstrate that quercetin activates the HIF-1 signaling pathway in human lens epithelial cells

    The flavonoid galangin is an inhibitor of CYP1A1 activity and an agonist/antagonist of the aryl hydrocarbon receptor

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    The effect of the dietary flavonoid galangin on the metabolism of 7,12-dimethylbenz[a]anthracene (DMBA), the activity of cytochrome P 450 1A1 (CYP1A1), and the expression of CYP1A1 in MCF-7 human breast carcinoma cells was investigated. Galangin inhibited the catabolic breakdown of DMBA, as measured by thin-layer chromatography, in a dose-dependent manner. Galangin also inhibited the formation of DMBA-DNA adducts, and prevented DMBA-induced inhibition of cell growth. Galangin caused a potent, dose-dependent inhibition of CYP1A1 activity, as measured by ethoxyresorufin-O-deethylase activity, in intact cells and in microsomes isolated from DMBA-treated cells. Analysis of the inhibition kinetics by double-reciprocal plot demonstrated that galangin inhibited CYP1A1 activity in a non-competitive manner. Galangin caused an increase in the level of CYP1A1 mRNA, indicating that it may be an agonist of the aryl hydrocarbon receptor, but it inhibited the induction of CYP1A1 mRNA by DMBA or by 2,3,5,7-tetrachlorodibenzo-p-dioxin (TCDD). Galangin also inhibited the DMBA- or TCDD-induced transcription of a reporter vector containing the CYP1A1 promoter. Thus, galangin is a potent inhibitor of DMBA metabolism and an agonist/antagonist of the AhR, and may prove to be an effective chemopreventive agent. © 1999 Cancer Research Campaig

    Precise microwave characterization of MgO substrates for HTS circuits with superconducting post dielectric resonator

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    Accurate data of complex permittivity of dielectric substrates are needed for efficient design of HTS microwave planar circuits. We have tested MgO substrates from three different manufacturing batches using a dielectric resonator with superconducting parts recently developed for precise microwave characterization of laminar dielectrics at cryogenic temperatures. The measurement fixture has been fabricated using a SrLaAlO3 post dielectric resonator with DyBa2Cu3O7 end plates and silver-plated copper sidewalls to achieve the resolution of loss tangent measurements of 2 {\times} 10-6. The tested MgO substrates exhibited the average relative permittivity of 9.63 and tan {\delta} from 3.7 {\times} 10-7 to 2 {\times} 10-5 at frequency of 10.5 GHz in the temperature range from 14 to 80 K.Comment: 6 pages, 8 figures, 3 table

    Commissioning of inline ECE system within waveguide based ECRH transmission systems on ASDEX upgrade

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    A CW capable inline electron cyclotron emission (ECE) separation system for feedback control, featuring oversized corrugated waveguides, is commissioned on ASDEX upgrade (AUG). The system is based on a combination of a polarization independent, non-resonant, Mach-Zehnder diplexer equipped with dielectric plate beam splitters [2, 3] employed as corrugated oversized waveguide filter, and a resonant Fast Directional Switch, FADIS [4, 5, 6, 7] as ECE/ECCD separation system. This paper presents an overview of the system, the low power characterisation tests and first high power commissioning on AUG

    Bimodal action of the flavonoid quercetin on basophil function: an investigation of the putative biochemical targets

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    <p>Abstract</p> <p>Background</p> <p>Flavonoids, a large group of polyphenolic metabolites derived from plants have received a great deal of attention over the last several decades for their properties in inflammation and allergy. Quercetin, the most abundant of plant flavonoids, exerts a modulatory action at nanomolar concentrations on human basophils. As this mechanism needs to be elucidated, in this study we focused the possible signal transduction pathways which may be affected by this compound. Methods: K2-EDTA derived leukocyte buffy coats enriched in basophil granulocytes were treated with different concentrations of quercetin and triggered with anti-IgE, fMLP, the calcium ionophore A23187 and the phorbol ester PMA in different experimental conditions. Basophils were captured in a flow cytometry analysis as CD123bright/HLADRnon expressing cells and fluorescence values of the activation markers CD63-FITC or CD203c-PE were used to produce dose response curves. The same population was assayed for histamine release.</p> <p>Results</p> <p>Quercetin inhibited the expression of CD63 and CD203c and the histamine release in basophils activated with anti-IgE or with the ionophore: the IC50 in the anti-IgE model was higher than in the ionophore model and the effects were more pronounced for CD63 than for CD203c. Nanomolar concentrations of quercetin were able to prime both markers expression and histamine release in the fMLP activation model while no effect of quercetin was observed when basophils were activated with PMA. The specific phosphoinositide-3 kinase (PI3K) inhibitor wortmannin exhibited the same behavior of quercetin in anti-IgE and fMLP activation, thus suggesting a role for PI3K involvement in the priming mechanism.</p> <p>Conclusions</p> <p>These results rule out a possible role of protein kinase C in the complex response of basophil to quercetin, while indirectly suggest PI3K as the major intracellular target of this compound also in human basophils.</p
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