2,863 research outputs found

    Low scatter lens design/development

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    The criteria for the optimum design of optical systems are discussed along with the selection of appropriate materials. The construction details of low scatter lens systems are tabulated. Scattering analysis; total energy diffracted; and computation of delta for a scratch, bubble, and microscopic irregularities are also discussed

    A Note on the Extensions of Eratosthenes Sieve

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    Scalable squeezed light source for continuous variable quantum sampling

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    We propose a novel squeezed light source capable of meeting the stringent requirements of continuous variable quantum sampling. Using the effective χ2\chi_2 interaction induced by a strong driving beam in the presence of the χ3\chi_3 response in an integrated microresonator, our device is compatible with established nanophotonic fabrication platforms. With typical realistic parameters, squeezed states with a mean photon number of 10 or higher can be generated in a single consistent temporal mode at repetition rates in excess of 100MHz. Over 15dB of squeezing is achievable in existing ultra-low loss platforms

    Prehabilitation Before Total Knee Arthroplasty Increases Strength and Function in Older Adults With Severe Osteoarthritis

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    Preparing for the stress of total knee arthroplasty (TKA) surgery by exercise training (prehabilitation) may improve strength and function before surgery and, if effective, has the potential to contribute to postoperative recovery. Subjects with severe osteoarthritis (OA), pain intractable to medicine and scheduled for TKA were randomized into a usual care (UC) group (n = 36) or usual care and exercise (UC + EX) group (n = 35). The UC group maintained normal daily activities before their TKA. The UC + EX group performed a comprehensive prehabilitation program that included resistance training using bands, flexibility, and step training at least 3 times per week for 4-8 weeks before their TKA in addition to UC. Leg strength (isokinetic peak torque for knee extension and flexion) and ability to perform functional tasks (6-minute walk, 30 second sit-to-stand repetitions, and the time to ascend and descend 2 flights of stairs) were assessed before randomization at baseline (T1) and 1 week before the subject\u27s TKA (T2). Repeated-measures analysis of variance indicated a significant group by time interaction (p \u3c 0.05) for the 30-second sit-to-stand repetitions, time to ascend the first flight of stairs, and peak torque for knee extension in the surgical knee. Prehabilitation increased leg strength and the ability to perform functional tasks for UC + EX when compared to UC before TKA. Short term (4-8 weeks) of prehabilitation was effective for increasing strength and function for individuals with severe OA. The program studied is easily transferred to a home environment, and clinicians working with this population should consider prehabilitation before TKA. [PUBLICATION ABSTRACT

    On the number variance of zeta zeros and a conjecture of Berry

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    Assuming the Riemann hypothesis, we prove estimates for the variance of the real and imaginary part of the logarithm of the Riemann zeta-function in short intervals. We give three different formulations of these results. Assuming a conjecture of Chan for how often gaps between zeros can be close to a fixed nonzero value, we prove a conjecture of Berry (1988) for the number variance of zeta zeros in the non-universal regime. In this range, GUE statistics do not describe the distribution of the zeros. We also calculate lower-order terms in the second moment of the logarithm of the modulus of the Riemann zeta-function on the critical line. Assuming Montgomery's pair correlation conjecture, this establishes a special case of a conjecture of Keating and Snaith (2000).Comment: 38 pages. To appear in Mathematik

    Phase-locking of a Nonlinear Optical Cavity via Rocking: Transmuting Vortices into Phase Patterns

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    We report experimental observation of the conversion of a phase-invariant nonlinear system into a phase-locked one via the mechanism of rocking [G. J. de Valcarcel and K. Staliunas, Phys. Rev. E 67, 026604 (2003)]. This conversion results in that vortices of the phase-invariant system are being replaced by phase patterns such as domain walls. The experiment is carried out on a photorefractive oscillator in two-wave mixing configuration.A model for the experimental device is given that reproduces the observed behavior.Comment: 9 pages and 4 figure

    Marine sponge as a source of antiangiogenic compounds. The case of aeroplysinin-1

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    The vast majority of the natural compounds that have been previously described as inhibitors of angiogenesis have been isolated from plants and terrestrial microorganisms, mainly due to their higher availability and because their therapeutic effects had been previously known in folk traditional medicines. However, increasing attention is being paid to the development of marine-derived antiangiogenic agents, probably fuelled by the increase in the number of marine-derived anticancer drugs which are being successfully used for cancer therapy. Marine organisms, adapted to survive in extreme environments by developing chemical means of defence, produce interesting and singular pharmacological lead compounds, derived from the large diversity of marine habitats and environmental conditions. Among the many different types of marine organisms used as a source for drug discovery, sponges represent one of the most promising sources of leads in the research of new cancer drugs. Some angiogenesis inhibitors isolated from marine sponges have been described by us and others. Aeroplysinin-1, a brominated metabolite extracted from the marine sponge Aplysina aerophoba, has been characterized by our group as a potent antiangiogenic compound in vitro and in vivo. Aeroplysinin-1 induces apoptosis in endothelial cells by a mechanism which involves activation of the BH3-only pro-apoptotic protein Bad, cytochrome c release and activation of caspases 2, 3, 8 and 9, what indicates a relevant role of the mitochondria in the apoptogenic activity of this compound. Recent results suggest that aeroplysinin-1 could also be a novel potential anti-inflammatory compound. These results open new ways to the potential pharmacological action of aeroplysinin-1 not only on angiogenesis and cancer, but also on atherosclerosis and inflammation-dependent diseases.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
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