2,206 research outputs found

    Amplitude Modulation and Demodulation of Electromagnetic Wave in Magnetised Diffusive Semiconductors

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    The rigidity of crystalline color superconducting quark matter

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    We calculate the shear modulus of crystalline color superconducting quark matter, showing that this phase of dense, but not asymptotically dense, three-flavor quark matter responds to shear stress like a very rigid solid. To evaluate the shear modulus, we derive the low energy effective Lagrangian that describes the phonons that originate from the spontaneous breaking of translation invariance by the spatial modulation of the gap parameter Δ\Delta. These massless bosons describe space- and time-dependent fluctuations of the crystal structure and are analogous to the phonons in ordinary crystals. The coefficients of the spatial derivative terms of the phonon effective Lagrangian are related to the elastic moduli of the crystal; the coefficients that encode the linear response of the crystal to a shearing stress define the shear modulus. We analyze the two particular crystal structures which are energetically favored over a wide range of densities, in each case evaluating the phonon effective action and the shear modulus up to order Δ2\Delta^2 in a Ginzburg-Landau expansion, finding shear moduli which are 20 to 1000 times larger than those of neutron star crusts. The crystalline color superconducting phase has long been known to be a superfluid -- by picking a phase its order parameter breaks the quark-number U(1)BU(1)_B symmetry spontaneously. Our results demonstrate that this superfluid phase of matter is at the same time a rigid solid. We close with a rough estimate of the pinning force on the rotational vortices which would be formed embedded within this rigid superfluid upon rotation. Our results raise the possibility that (some) pulsar glitches could originate within a quark matter core deep within a neutron star.Comment: 38 pages, 5 figures. v3. Two new paragraphs in Section V (Conclusion); some additional small changes. A paragraph discussing supercurrents added in Section I (Introduction). Version to appear in Phys. Rev.

    Early Health Economic Modeling of Novel Therapeutics in Age-Related Hearing Loss

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    Background: Health systems face challenges to accelerate access to innovations that add value and avoid those unlikely to do so. This is very timely to the field of age-related sensorineural hearing loss (ARHL), where a significant unmet market need has been identified and sizeable investments made to promote the development of novel hearing therapeutics (NT). This study aims to apply health economic modeling to inform the development of cost-effective NT. Methods: We developed a decision-analytic model to assess the potential costs and effects of using regenerative NT in patients ≥50 with ARHL. This was compared to the current standard of care including hearing aids and cochlear implants. Input data was collected from systematic literature searches and expert opinion. A UK NHS healthcare perspective was adopted. Three different but related analyses were performed using probabilistic modeling: (1) headroom analysis, (2) scenario analyses, and (3) threshold analyses. Results: The headroom analysis shows an incremental net monetary benefit (iNMB) of £20,017[£11,299–£28,737] compared to the standard of care due to quality-adjusted life-years (QALY) gains and cost savings. Higher therapeutic efficacy and access for patients with all degrees of hearing loss yields higher iNMBs. Threshold analyses shows that the ceiling price of the therapeutic increases with more severe degrees of hearing loss. Conclusion: NT for ARHL are potentially cost-effective under current willingness-to-pay (WTP) thresholds with considerable room for improvement in the current standard of care pathway. Our model can be used to help decision makers decide which therapeutics represent value for money and are worth commissioning, thereby paving the way for urgently needed NT

    Modelling of COVID-19 Using Fractional Differential Equations

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    In this work, we have described the mathematical modeling of COVID-19 transmission using fractional differential equations. The mathematical modeling of infectious disease goes back to the 1760s when the famous mathematician Daniel Bernoulli used an elementary version of compartmental modeling to find the effectiveness of deliberate smallpox inoculation on life expectancy. We have used the well-known SIR (Susceptible, Infected and Recovered) model of Kermack & McKendrick to extend the analysis further by including exposure, quarantining, insusceptibility and deaths in a SEIQRDP model. Further, we have generalized this model by using the solutions of Fractional Differential Equations to test the accuracy and validity of the mathematical modeling techniques against Canadian COVID-19 trends and spread of real-world disease. Our work also emphasizes the importance of Personal Protection Equipment (PPE) and impact of social distancing on controlling the spread of COVID-19

    Effect of hydroxychloroquine in viral clearance in nCOV-19 infected patient admitted in tertiary care centre, Ranchi, Jharkhand, India

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    Background: In view of recent publications of conflicting evidence on the safety and efficacy of hydroxychloroquine as prophylaxis and as a treatment for COVID-19 patients, we need to assess the effect of hydroxychloroquine in COVID-19 patients of authors own local population.Methods: In this retrospective chart review study, categorization of confirmed COVID-19 cases nasopharyngeal swab of RT-PCR was done into a group of patients who received hydroxychloroquine standard dose and another control group who did not receive hydroxychloroquine. The main comparing parameter was to see virus clearance days across both groups.Results: A total of 112 patients were included for the study, and grouped of 72 patient who received HCQS and remaining 40 patients as control. The virus clearance time in days was found to be 9.01±3.08 for HCQS group and for control group it was 8.64±2.34 days (Man Whitney U test value = 2.13, p=0.756).Conclusions: There is no significant difference found in attaining virus negative status with use of HCQS administration in this study
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