1,136 research outputs found

    Dust Storms in Space?

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    Primarily from the Pioneer 8 and 9 results, it is concluded that the flux of picogram sized dust particles near the earth's orbit has been constant to within the observational limits over three years of observation. In particular, since dust streams are not observed, they cannot explain microphone detected events. However, the possibility of rare events due to dust blown directly off a cometary nucleus (such as that reported for Comet Bennett) cannot be completely ruled out

    Theory of Optical Tweezers

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    We derive a partial-wave (Mie) expansion of the axial force exerted on a transparent sphere by a laser beam focused through a high numerical aperture objective. The results hold throughout the range of interest for practical applications. The ray optics limit is shown to follow from the Mie expansion by size averaging. Numerical plots show large deviations from ray optics near the focal region and oscillatory behavior (explained in terms of a simple interferometer picture) of the force as a function of the size parameter. Available experimental data favor the present model over previous ones.Comment: 4 pages, 3 figure

    The Ursinus Weekly, November 11, 1963

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    Carol Heber, Homecoming queen; Emmert receives Walker trophy • Catherine Drinker Bowen to be guest speaker at Forum • WSGA meeting set for Sunday • Past UC speaker in protest against Mme. Nhu before fall of regime • Volunteers for St. Gabriels to meet Tuesday • Alumni contribute $220,000 to Centennial Fund • Student rumor clarified • 17 men go Greek in Fall rushing • AAUW discusses community college • Professor chief editor of new publication • Ursinus gets portrait of Henry T. Spangler • Folksing begins weekend • MSGA sponsors bus to next game • Editorial: Women, it\u27s now or never; Kaffee Klatsch; Complaint for complaint\u27s sake? • Have you read: Travels with Charley • Swedish student studying here • Art class tours Philly museum • Letters to the editor • Excellent concert heard by students • Colgan views Cuba as potential source of war • Republicans view election returns • Thai student to speak at Kaffee Klatsch Friday • Ursinus Band: Review & outlook • Greek gleanings • Senior women reply to WSGA questionnaire with emphatic views • Jobs open for political interns • Parsons speaks on Daniel Claus • Outing Club on spelunking trip • Alpha Phi Omega plans open meeting • Bears trounce Fords 32 to 8 as Emmert stars in Homecoming tilt • Player of the week interview: Ron Emmert • UC puts three on college team • Soccer team beats La Salle, alumni • JV and 3rd teams take Immaculatahttps://digitalcommons.ursinus.edu/weekly/1257/thumbnail.jp

    Patient-Reported Side Effects of Intradetrusor Botulinum Toxin Type A for Idiopathic Overactive Bladder Syndrome

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    Objective: The aim of the study was a prospective assessment of patient-reported side effects in an open-label study after intradetrusor botulinum toxin injections for idiopathic overactive bladder (OAB). Patients and Methods: Botulinum toxin A injection was performed in 56 patients with idiopathic OAB. Patients were followed up for 6 months concerning side effects and patients' satisfaction. Results: Different types of side effects were assessed such as dry mouth (19.6%), arm weakness (8.9%), eyelid weakness (8.9%), leg weakness (7.1%), torso weakness (5.4%), impaired vision (5.4%) and dysphagia (5.4%). In all cases, symptoms were mild and transient. Urological complications such as gross hematuria (17.9%), acute urinary retention (8.9%) and acute urinary tract infection (7.1%) were noticed. In all cases, acute urinary retention was transient and treated with temporary intermittent self-catheterization. There was no statistically significant correlation between dosage and observed side effects. Patients' satisfaction rate was high (71.4%). Conclusion: Intradetrusor injection of botulinum toxin was associated with a high rate of neurourological side effects. In general, side effects were transient, mild and did not require special treatment. Copyright (C) 2010 S. Karger AG, Base

    Detection of the tagged or untagged photons in acousto-optic imaging of thick highly scattering media by photorefractive adaptive holography

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    We propose an original adaptive wavefront holographic setup based on the photorefractive effect (PR), to make real-time measurements of acousto-optic signals in thick scattering media, with a high flux collection at high rates for breast tumor detection. We describe here our present state of art and understanding on the problem of breast imaging with PR detection of the acousto-optic signal

    Extension of Yeast Chronological Lifespan by Methylamine

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    Background: Chronological aging of yeast cells is commonly used as a model for aging of human post-mitotic cells. The yeast Saccharomyces cerevisiae grown on glucose in the presence of ammonium sulphate is mainly used in yeast aging research. We have analyzed chronological aging of the yeast Hansenula polymorpha grown at conditions that require primary peroxisome metabolism for growth. Methodology/Principal Findings: The chronological lifespan of H. polymorpha is strongly enhanced when cells are grown on methanol or ethanol, metabolized by peroxisome enzymes, relative to growth on glucose that does not require peroxisomes. The short lifespan of H. polymorpha on glucose is mainly due to medium acidification, whereas most likely ROS do not play an important role. Growth of cells on methanol/methylamine instead of methanol/ammonium sulphate resulted in further lifespan enhancement. This was unrelated to medium acidification. We show that oxidation of methylamine by peroxisomal amine oxidase at carbon starvation conditions is responsible for lifespan extension. The methylamine oxidation product formaldehyde is further oxidized resulting in NADH generation, which contributes to increased ATP generation and reduction of ROS levels in the stationary phase. Conclusion/Significance: We conclude that primary peroxisome metabolism enhanced chronological lifespan of H. polymorpha. Moreover, the possibility to generate NADH at carbon starvation conditions by an organic nitrogen source supports further extension of the lifespan of the cell. Consequently, the interpretation of CLS analyses in yeast should include possible effects on the energy status of the cell.

    Consumers' Willingness to Pay for Quality and Safety in Clams

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    The aim of the research is to estimate the potential demand for certified clams in Italy and to investigate the determinants of maximum amount that respondents are willing to pay for this product. Quantitative analysis was used based on 1,067 face-to-face interviews collected in 3 Italian regions in the north bordering the Adriatic Sea (Friuli-Venezia Giulia, Veneto, and Emilia-Romagna) carried out during 2008. The consumers' willingness to pay (WTP) is measured using a contingent valuation method. In order to estimate separately the determinants of the probability that respondents are willing to pay and the maximum that they are willing to pay, a generalization of Tobit model was adopted. The results indicate that consumers are willing to pay a premium price mainly to purchase better quality products. The research provides some initial insight into consumers' WTP that can be useful for certified fish farming. © 2014 Taylor & Francis Group, LLC

    A Highly Conserved Poc1 Protein Characterized in Embryos of the Hydrozoan Clytia hemisphaerica: Localization and Functional Studies

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    Poc1 (Protein of Centriole 1) proteins are highly conserved WD40 domain-containing centriole components, well characterized in the alga Chlamydomonas, the ciliated protazoan Tetrahymena, the insect Drosophila and in vertebrate cells including Xenopus and zebrafish embryos. Functions and localizations related to the centriole and ciliary axoneme have been demonstrated for Poc1 in a range of species. The vertebrate Poc1 protein has also been reported to show an additional association with mitochondria, including enrichment in the specialized “germ plasm” region of Xenopus oocytes. We have identified and characterized a highly conserved Poc1 protein in the cnidarian Clytia hemisphaerica. Clytia Poc1 mRNA was found to be strongly expressed in eggs and early embryos, showing a punctate perinuclear localization in young oocytes. Fluorescence-tagged Poc1 proteins expressed in developing embryos showed strong localization to centrioles, including basal bodies. Anti-human Poc1 antibodies decorated mitochondria in Clytia, as reported in human cells, but failed to recognise endogenous or fluorescent-tagged Clytia Poc1. Injection of specific morpholino oligonucleotides into Clytia eggs prior to fertilization to repress Poc1 mRNA translation interfered with cell division from the blastula stage, likely corresponding to when neosynthesis normally takes over from maternally supplied protein. Cell cycle lengthening and arrest were observed, phenotypes consistent with an impaired centriolar biogenesis or function. The specificity of the defects could be demonstrated by injection of synthetic Poc1 mRNA, which restored normal development. We conclude that in Clytia embryos, Poc1 has an essentially centriolar localization and function
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