1,653 research outputs found

    A photon-counting photodiode array detector for far ultraviolet (FUV) astronomy

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    A compact, stable, single-stage intensified photodiode array detector designed for photon-counting, far ultraviolet astronomy applications employs a saturable, 'C'-type MCP (Galileo S. MCP 25-25) to produce high gain pulses with a narrowly peaked pulse height distribution. The P-20 output phosphor exhibits a very short decay time, due to the high current density of the electron pulses. This intensifier is being coupled to a self-scanning linear photodiode array which has a fiber optic input window which allows direct, rigid mechanical coupling with minimal light loss. The array was scanned at a 250 KHz pixel rate. The detector exhibits more than adequate signal-to-noise ratio for pulse counting and event location

    Validation of a soft sensor network for condition monitoring in hydraulic systems

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    With increasing digitization, models are more important than ever. Especially their use as soft sensors during operation offers opportunities in cost saving, easy data acquisition and therefore additional functionality of systems. In soft sensor networks there is redundant data acquisition and consequently the occurrence of inconsistent values from different soft sensors is encouraged. The resolution of these data-induced conflicts allows for the detection of changing components characteristics. Hence soft sensor networks can be used to detect wear in system components. In this paper this approach is validated on a test rig. It is found, that the soft sensor network is capable to determine wear and its extent in eccentric screw pumps and valves via data induced conflicts with relatively simple models

    CONTRIBUTO ALLA CONOSCENZA E DISTRIBUZIONE DELLE CRAMBINE (LEP.-PYRALIDAE) IN ITALIA

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    L'impianto di una nuova collezione di Microlepidotteri paleartici, data l'inaccessibilità di quella da me donata nel 1941 allo Stato Italiano, mi ha indotto a questa pubblicazione, apportando alcune nuove località per specie già note, correzioni di errori e di sviste nella collezione TURATI ed infine la descrizione di una nuova specie di Catoptria Hb. dell'Aspromonte

    CONTRIBUTO ALLA CONOSCENZA DI ALCUNI LEPIDOTTERI LUCANI

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    Dopo sette anni di intense ricerche sul Monte Vulture in Lucania, a Monticchio e nella valle dell'Ofanto, oltre a certe inattese scoperte come quella della Brahmaea europaea, HTG., dell'Orthoxistis cribraria HB., e della Sparta paradoxaria STGR., nonché di varie altre sorprese tra i Macro e Microlepidotteri, avevo pubblicato in modo preliminare alcune delle nuove razze caratteristiche per la zona, come pure il rinvenimento della Orrhodiella ragusae F.T., i cui tipi sono andati persi come purtroppo tanti altri nel nostro paese (Spinola, O. Costa, Turati, ecc.). Se queste scoperte hanno destato interesse generale nel mondo scientifico, esse si devono anzitutto alla comprensiva collaborazione della Direzione Generale delle Foreste nella persona del Direttore Generale dott. Vitantonio Pizzigallo, del Vicedirettore Generale dott. Angelo Zambelli degli Amministratori delle Foreste Demaniali della Basilicata, i dott. Giorgio Giani e Luigi Arciuli, nonché di tutto il personale delle Foreste Demaniali di Monticchio. A tutti vadano i miei sentiti ringraziamenti. Grazie al valido appoggio ed alla alta comprensione del Prof. Domenico Roberti, Direttore dell'Istituto di Entomologia Agraria dell'Università di Bari, posso ora presentare in riproduzione a colori e con la relativa morfologia, le dette specie. Ringrazio qui, oltre il Prof. Roberti, i colleghi delle Collezioni Zoologiche dello Stato Bavarese ed in modo particolare il Direttore Dott. Walter Forster per avermi procurato la possibilità di riprodurre le appendici genitali, dato che ancora non posso disporre dei mezzi tecnici dell'Istituto Nazionale di Entomologia da me fondato e donato allo Stato Italiano. Le fotografie a colori vennero eseguite nel mio Istituto di Entomologia a Bolzano

    Wide-Field Multi-Parameter FLIM: Long-Term Minimal Invasive Observation of Proteins in Living Cells.

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    Time-domain Fluorescence Lifetime Imaging Microscopy (FLIM) is a remarkable tool to monitor the dynamics of fluorophore-tagged protein domains inside living cells. We propose a Wide-Field Multi-Parameter FLIM method (WFMP-FLIM) aimed to monitor continuously living cells under minimum light intensity at a given illumination energy dose. A powerful data analysis technique applied to the WFMP-FLIM data sets allows to optimize the estimation accuracy of physical parameters at very low fluorescence signal levels approaching the lower bound theoretical limit. We demonstrate the efficiency of WFMP-FLIM by presenting two independent and relevant long-term experiments in cell biology: 1) FRET analysis of simultaneously recorded donor and acceptor fluorescence in living HeLa cells and 2) tracking of mitochondrial transport combined with fluorescence lifetime analysis in neuronal processes

    The Ultraviolet Emission Properties of Five Low-Redshift Active Galactic Nuclei at High Signal to Noise and Spectral Resolution

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    We analyze the ultraviolet (UV) emission line and continuum properties of five low-redshift active galactic nuclei (four luminous quasars: PKS~0405-123, H1821+643, PG~0953+414, and 3C273, and one bright Seyfert 1 galaxy: Mrk~205). The HST spectra have higher signal-to-noise ratios (typically 60\sim 60 per resolution element) and spectral resolution (R=1300R = 1300) than all previously- published UV spectra used to study the emission characteristics of active galactic nuclei. We include in the analysis ground-based optical spectra covering \hb\ and the narrow [O III] λλ\lambda\lambda4959,5007 doublet. The following new results are obtained: \lyb/\lya=0.03-0.12 for the four quasars, which is the first accurate measurement of the long-predicted \lyb\ intensity in QSOs. The cores of \lya\ and C~IV are symmetric to an accuracy of better than 2.5% within about 2000 km s1^{-1} of the line peak. This high degree of symmetry of \lya\ argues against models in which the broad line cloud velocity field has a significant radial component. The observed smoothness of the \lya\ and C~IV line profiles requires at least 104\sim 10^4 individual clouds if bulk velocity is the only line-broadening mechanism. The overall similarity of the \lya\ and C IV λ\lambda1549 profiles rules out models for the broad line region (BLR) with a radial distribution of virialized....Comment: 39 pages (+ 6 pages of tables + 16 of figures), AST 93/2

    Using Sensors and Generators of H2O2 to Elucidate the Toxicity Mechanism of Piperlongumine and Phenethyl Isothiocyanate

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    Aims: Chemotherapeutics target vital functions that ensure survival of cancer cells, including their increased reliance on defense mechanisms against oxidative stress compared to normal cells. Many chemotherapeutics exploit this vulnerability to oxidative stress by elevating the levels of intracellular reactive oxygen species (ROS). A quantitative understanding of the oxidants generated and how they induce toxicity will be important for effective implementation and design of future chemotherapeutics. Molecular tools that facilitate measurement and manipulation of individual chemical species within the context of the larger intracellular redox network present a means to develop this understanding. In this work, we demonstrate the use of such tools to elucidate the roles of H[subscript 2]O[subscript 2] and glutathione (GSH) in the toxicity mechanism of two ROS-based chemotherapeutics, piperlongumine and phenethyl isothiocyanate. Results: Depletion of GSH as a result of treatment with these compounds is not an important part of the toxicity mechanisms of these drugs and does not lead to an increase in the intracellular H[subscript 2]O[subscript 2] level. Measuring peroxiredoxin-2 (Prx-2) oxidation as evidence of increased H[subscript 2]O[subscript 2], only piperlongumine treatment shows elevation and it is GSH independent. Using a combination of a sensor (HyPer) along with a generator (D-amino acid oxidase) to monitor and mimic the drug-induced H[subscript 2O[subscript 2] production, it is determined that H[subscript 2]O[subscript 2] produced during piperlongumine treatment acts synergistically with the compound to cause enhanced cysteine oxidation and subsequent toxicity. The importance of H[subscript 2]O[subscript 2] elevation in the mechanism of piperlongumine promotes a hypothesis of why certain cells, such as A549, are more resistant to the drug than others. Innovation and Conclusion: The approach described herein sheds new light on the previously proposed mechanism of these two ROS-based chemotherapeutics and advocates for the use of both sensors and generators of specific oxidants to isolate their effects. Antioxid. Redox Signal. 24, 924–938.National Science Foundation (U.S.). Graduate Research Fellowship ProgramBurroughs Wellcome Fund (Career Award at the Scientific Interface
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