3,511 research outputs found

    Developmental Rate and Longevity of \u3ci\u3eIllinoia Pepperi\u3c/i\u3e (Homoptera: Aphididae) on Excised Blueberry Leaf Disks

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    The aphid Illinoia pepperi is the vector of blueberry shoestring virus, a serious disease of cultivated high bush blueberry. We present a laboratory study of the developmental rate of I. pepperi on excised blueberry leaf discs at different temperatures from 5 to 29°C. Growth rates were lowest at the upper temperature treatments (26 and 29°) and at 10°C. Growth rate and duration in degree-days for each life stage are presented as well as an overall regression equation for development. The lower developmental threshold was calculated at 3.4°C. The results are being used in a phenological management system and an epidemiological model for predicting spread of blueberry shoestring virus

    Using hybrid GPU/CPU kernel splitting to accelerate spherical convolutions

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    We present a general method for accelerating by more than an order of magnitude the convolution of pixelated functions on the sphere with a radially-symmetric kernel. Our method splits the kernel into a compact real-space component and a compact spherical harmonic space component. These components can then be convolved in parallel using an inexpensive commodity GPU and a CPU. We provide models for the computational cost of both real-space and Fourier space convolutions and an estimate for the approximation error. Using these models we can determine the optimum split that minimizes the wall clock time for the convolution while satisfying the desired error bounds. We apply this technique to the problem of simulating a cosmic microwave background (CMB) anisotropy sky map at the resolution typical of the high resolution maps produced by the Planck mission. For the main Planck CMB science channels we achieve a speedup of over a factor of ten, assuming an acceptable fractional rms error of order 1.e-5 in the power spectrum of the output map.Comment: 9 pages, 11 figures, 1 table, accepted by Astronomy & Computing w/ minor revisions. arXiv admin note: substantial text overlap with arXiv:1211.355

    On the changes in number and intensity of North Atlantic tropical cyclones

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    Bayesian statistical models were developed for the number of tropical cyclones and the rate at which these cyclones became hurricanes in the North Atlantic. We find that, controlling for the cold tongue index and the North Atlantic oscillation index, there is high probability that the number of cyclones has increased in the past thirty years; but the rate at which these storms become hurricanes appears to be constant. We also investigate storm intensity by measuring the distribution of individual storm lifetime in days, storm track length, and Emanuel's power dissiptation index. We find little evidence that the distribution of individual storm intensity is changing through time. Any increase in cumulative yearly storm intensity and potential destructiveness, therefore, is due to the increasing number of storms and not due to any increase in the intensity of individual storms.Comment: 24 pages, 9 figure

    The Simplicial Characterisation of TS networks: Theory and applications

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    We use the visibility algorithm to construct the time series networks obtained from the time series of different dynamical regimes of the logistic map. We define the simplicial characterisers of networks which can analyse the simplicial structure at both the global and local levels. These characterisers are used to analyse the TS networks obtained in different dynamical regimes of the logisitic map. It is seen that the simplicial characterisers are able to distinguish between distinct dynamical regimes. We also apply the simplicial characterisers to time series networks constructed from fMRI data, where the preliminary results indicate that the characterisers are able to differentiate between distinct TS networks.Comment: 11 pages, 2 figures, 4 tables. Accepted for publication in Proceedings of the 4th International Conference on Applications in Nonlinear Dynamics (ICAND 2016

    The Anderson model of localization: a challenge for modern eigenvalue methods

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    We present a comparative study of the application of modern eigenvalue algorithms to an eigenvalue problem arising in quantum physics, namely, the computation of a few interior eigenvalues and their associated eigenvectors for the large, sparse, real, symmetric, and indefinite matrices of the Anderson model of localization. We compare the Lanczos algorithm in the 1987 implementation of Cullum and Willoughby with the implicitly restarted Arnoldi method coupled with polynomial and several shift-and-invert convergence accelerators as well as with a sparse hybrid tridiagonalization method. We demonstrate that for our problem the Lanczos implementation is faster and more memory efficient than the other approaches. This seemingly innocuous problem presents a major challenge for all modern eigenvalue algorithms.Comment: 16 LaTeX pages with 3 figures include

    Forecasting constraints from the cosmic microwave background on eternal inflation

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    We forecast the ability of cosmic microwave background (CMB) temperature and polarization datasets to constrain theories of eternal inflation using cosmic bubble collisions. Using the Fisher matrix formalism, we determine both the overall detectability of bubble collisions and the constraints achievable on the fundamental parameters describing the underlying theory. The CMB signatures considered are based on state-of-the-art numerical relativistic simulations of the bubble collision spacetime, evolved using the full temperature and polarization transfer functions. Comparing a theoretical cosmic-variance-limited experiment to the WMAP and Planck satellites, we find that there is no improvement to be gained from future temperature data, that adding polarization improves detectability by approximately 30%, and that cosmic-variance-limited polarization data offer only marginal improvements over Planck. The fundamental parameter constraints achievable depend on the precise values of the tensor-to-scalar ratio and energy density in (negative) spatial curvature. For a tensor-to-scalar ratio of 0.10.1 and spatial curvature at the level of 10410^{-4}, using cosmic-variance-limited data it is possible to measure the width of the potential barrier separating the inflating false vacuum from the true vacuum down to MPl/500M_{\rm Pl}/500, and the initial proper distance between colliding bubbles to a factor π/2\pi/2 of the false vacuum horizon size (at three sigma). We conclude that very near-future data will have the final word on bubble collisions in the CMB.Comment: 14 pages, 6 figure

    Photodynamische Therapie (PDT) und wassergefiltertes Infrarot A (wIRA) bei Patienten mit therapierefraktären vulgären Hand- und Fußwarzen

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    Background: Common warts (verrucae vulgares) are human papilloma virus (HPV) infections with a high incidence and prevalence, most often affecting hands and feet, being able to impair quality of life. About 30 different therapeutic regimens described in literature reveal a lack of a single striking strategy. Recent publications showed positive results of photodynamic therapy (PDT) with 5-aminolevulinic acid (5-ALA) in the treatment of HPV-induced skin diseases, especially warts, using visible light (VIS) to stimulate an absorption band of endogenously formed protoporphyrin IX. Additional experiences adding waterfiltered infrared A (wIRA) during 5-ALA-PDT revealed positive effects. Aim of the study: First prospective randomised controlled blind study including PDT and wIRA in the treatment of recalcitrant common hand and foot warts. Comparison of "5-ALA cream (ALA) vs. placebo cream (PLC)" and "irradiation with visible light and wIRA (VIS+wIRA) vs. irradiation with visible light alone (VIS)". Methods: Pre-treatment with keratolysis (salicylic acid) and curettage. PDT treatment: topical application of 5-ALA (Medac) in "unguentum emulsificans aquosum" vs. placebo; irradiation: combination of VIS and a large amount of wIRA (Hydrosun® radiator type 501, 4 mm water cuvette, waterfiltered spectrum 590-1400 nm, contact-free, typically painless) vs. VIS alone. Post-treatment with retinoic acid ointment. One to three therapy cycles every 3 weeks. Main variable of interest: "Percent change of total wart area of each patient over the time" (18 weeks). Global judgement by patient and by physician and subjective rating of feeling/pain (visual analogue scales). 80 patients with therapy-resistant common hand and foot warts were assigned randomly into one of the four therapy groups with comparable numbers of warts at comparable sites in all groups. Results: The individual total wart area decreased during 18 weeks in group 1 (ALA+VIS+wIRA) and in group 2 (PLC+VIS+wIRA) significantly more than in both groups without wIRA (group 3 (ALA+VIS) and 4 (PLC+VIS)): medians and interquartile ranges: -94% (-100%/-84%) vs. -99% (-100%/-71%) vs. -47% (-75%/0%) vs. -73% (-92%/-27%). After 18 weeks the two groups with wIRA differed remarkably from the two groups without wIRA: 42% vs. 7% completely cured patients; 72% vs. 34% vanished warts. Global judgement by patient and by physician and subjective rating of feeling was much better in the two groups with wIRA than in the two groups without wIRA. Conclusions: The above described complete treatment scheme of hand and foot warts (keratolysis, curettage, PDT treatment, irradiation with VIS+wIRA, retinoic acid ointment; three therapy cycles every 3 weeks) proved to be effective. Within this treatment scheme wIRA as non-invasive and painless treatment modality revealed to be an important, effective factor, while photodynamic therapy with 5-ALA in the described form did not contribute recognisably - neither alone (without wIRA) nor in combination with wIRA - to a clinical improvement. For future treatment of warts an even improved scheme is proposed: one treatment cycle (keratolysis, curettage, wIRA, without PDT) once a week for six to nine weeks. © 2004 Fuchs et al; licensee German Medical Science. This is an Open Access article: verbatim copying and redistribution of this article are permitted in all media for any purpose, provided this notice is preserved along with the article's original URL : http://www.egms.de/en/gms/volume2.shtmlHintergrund: Vulgäre Warzen (Verrucae vulgares) sind humane Papillomvirus-Infektionen (HPV) mit einer hohen Inzidenz und Prävalenz, die am häufigsten Hände und Füße befallen und die in der Lage sind, die Lebensqualität zu beeinträchtigen. Etwa 30 in der Literatur beschriebene Therapieverfahren zeugen von einem Mangel an einer einzigen überzeugenden Strategie. Jüngste Veröffentlichungen zeigten positive Ergebnisse der Photodynamischen Therapie (PDT) mit 5-Aminolävulinsäure (5-ALA) in der Therapie von HPV-induzierten Hautkrankheiten, besonders Warzen, wobei sichtbares Licht (VIS) verwendet wird, um ein Absorptionsband des endogen aus 5-ALA gebildeten Protoporphyrin IX zu stimulieren. Weitere Erfahrungen, wassergefiltertes Infrarot A (wIRA) während der 5-ALA-PDT zusätzlich anzuwenden, offenbarten positive Wirkungen. Ziel der Untersuchung: Erste prospektive randomisierte kontrollierte Blind-Studie, die PDT und wIRA in die Behandlung von therapierefraktären vulgären Hand- und Fußwarzen einbezieht. Vergleich von "5-ALA-Salbe (ALA) vs. Placebo-Salbe (PLC)" und "Bestrahlung mit sichtbarem Licht und wIRA (VIS+wIRA) vs. Bestrahlung mit sichtbarem Licht allein (VIS)". Methoden: Vorbehandlung mit Keratolyse (Salizylsäure) und Kürettage. Photodynamische Therapie (PDT): topische Applikation von 5-ALA (Medac) in "Unguentum emulsificans aquosum" vs. Placebo; Bestrahlung: Kombination von sichtbarem Licht (VIS) und einem hohen Maß an wassergefiltertem Infrarot A (wIRA) (Hydrosun®-Strahler Typ 501, 4 mm Wasserküvette, wassergefiltertes Spektrum 590-1400 nm, kontaktfrei, typischerweise schmerzlos) vs. sichtbares Licht (VIS) allein. Nachbehandlung mit Vitamin-A-Säure-Salbe. Ein bis drei Therapiezyklen im Abstand von 3 Wochen. Hauptzielvariable: "Prozentuale Änderung der Gesamtwarzenfläche jedes Patienten über die Zeit" (18 Wochen). Globales Urteil von Patient und von Arzt sowie subjektive Einschätzung von Empfindung/Schmerz (visuelle Analogskalen). 80 Patienten mit therapierefraktären vulgären Hand- und Fußwarzen wurden randomisiert einer der vier Behandlungsgruppen (mit vergleichbarer Anzahl an Warzen in vergleichbaren Lokalisationen in allen Gruppen) zugeteilt. Ergebnisse: Die individuelle Gesamtwarzenfläche nahm während 18 Wochen in Gruppe 1 (ALA+VIS+wIRA) und in Gruppe 2 (PLC+VIS+wIRA) signifikant mehr als in den beiden Gruppen ohne wIRA (Gruppe 3 (ALA+VIS) und 4 (PLC+VIS)) ab: Mediane und Interquartil-Spannen: -94% (-100%/-84%) vs. -99% (-100%/-71%) vs. -47% (-75%/0%) vs. -73% (-92%/-27%). Nach 18 Wochen unterschieden sich die zwei Gruppen mit wIRA deutlich von den zwei Gruppen ohne wIRA: 42% vs. 7% komplett geheilte Patienten; 72% vs. 34% völlig verschwundene Warzen. Das globale Urteil von Patient und von Arzt und die subjektive Einschätzung des Empfindens waren in den zwei Gruppen mit wIRA viel besser als in den zwei Gruppen ohne wIRA. Folgerungen: Das oben beschriebene vollständige Therapieschema von Hand- und Fußwarzen (Keratolyse, Kürettage, Photodynamische Therapie, Bestrahlung mit VIS+wIRA, Vitamin-A-Säure-Salbe; drei Therapiezyklen im Abstand von 3 Wochen) erwies sich als effektiv. Innerhalb des Therapieschemas zeigte sich wIRA - als nicht-invasive und schmerzlose Therapiemodalität - als ein wichtiger, effektiver Faktor, während die Photodynamische Therapie mit 5-ALA in der beschriebenen Form nicht erkennbar - weder alleine (ohne wIRA) noch in Kombination mit wIRA - zu einer klinischen Verbesserung beitrug. Für die zukünftige Behandlung von Warzen wird ein weiter verbessertes Schema vorgeschlagen: ein Therapiezyklus (Keratolyse, Kürettage, wIRA, ohne PDT) einmal pro Woche für sechs bis neun Wochen

    Measurements with the Chandra X-Ray Observatory's flight contamination monitor

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    NASA's Chandra X-ray Observatory includes a Flight Contamination Monitor (FCM), a system of 16 radioactive calibration sources mounted to the inside of the Observatory's forward contamination cover. The purpose of the FCM is to verify the ground-to-orbit transfer of the Chandra flux scale, through comparison of data acquired during the ground calibration with those obtained in orbit, immediately prior to opening the Observatory's sun-shade door. Here we report results of these measurements, which place limits on the change in mirror--detector system response and, hence, on any accumulation of molecular contamination on the mirrors' iridium-coated surfaces.Comment: 7pages,8figures,for SPIE 4012, paper 7
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