Neurofilament light chain and tau concentrations are markedly increased in the serum of patients with sporadic Creutzfeldt-Jakob disease, and tau correlates with rate of disease progression

OBJECTIVES: A blood-based biomarker of neuronal damage in sporadic Creutzfeldt-Jakob disease (sCJD) will be extremely valuable for both clinical practice and research aiming to develop effective therapies. METHODS: We used an ultrasensitive immunoassay to measure two candidate biomarkers, tau and neurofilament light (NfL), in serum from patients with sCJD and healthy controls. We tested longitudinal sample sets from six patients to investigate changes over time, and examined correlations with rate of disease progression and associations with known phenotype modifiers. RESULTS: Serum concentrations of both tau and NfL were increased in patients with sCJD. NfL distinguished patients from controls with 100% sensitivity and 100% specificity. Tau did so with 91% sensitivity and 83% specificity. Both tau and NfL appeared to increase over time in individual patients, particularly in those with several samples tested late in their disease. Tau, but not NfL, was positively correlated with rate of disease progression, and was particularly increased in patients homozygous for methionine at codon 129 ofPRNP. CONCLUSIONS: These findings independently replicate other recent studies using similar methods and offer novel insights. They show clear promise for these blood-based biomarkers in prion disease. Future work should aim to fully establish their potential roles for monitoring disease progression and response to therapies

Resonance Phenomenon Related to Spectral Singularities, Complex Barrier Potential, and Resonating Waveguides

A peculiar property of complex scattering potentials is the appearance of spectral singularities. These are energy eigenvalues for certain scattering states that similarly to resonance states have infinite reflection and transmission coefficients. This property reveals an interesting resonance effect with possible applications in waveguide physics. We study the spectral singularities of a complex barrier potential and explore their application in designing a waveguide that functions as a resonator. We show that for the easily accessible sizes of the waveguide and its gain region, we can realize the spectral singularity-related resonance phenomenon at almost every wavelength within the visible spectrum or outside it.Comment: Published version, 20 pages, 2 tables, 7 figure

Electromagnetic field and radiation for a charge moving along a helical trajectory inside a waveguide with dielectric filling

We investigate the electromagnetic field generated by a point charge moving along a helical trajectory inside a circular waveguide with conducting walls filled by homogeneous dielectric. The parts corresponding to the radiation field are separated and the formulae for the radiation intensity are derived for both TE and TM waves. It is shown that the main part of the radiated quanta is emitted in the form of the TE waves. Various limiting cases are considered. The results of the numerical calculations show that the insertion of the waveguide provides an additional mechanism for tuning the characteristics of the emitted radiation by choosing the parameters of the waveguide and filling medium.Comment: 17 pages, 9 figures, discussion, graphs, and references adde

Q&A: What is biodiversity?

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Video enhancement using adaptive spatio-temporal connective filter and piecewise mapping

This paper presents a novel video enhancement system based on an adaptive spatio-temporal connective (ASTC) noise filter and an adaptive piecewise mapping function (APMF). For ill-exposed videos or those with much noise, we first introduce a novel local image statistic to identify impulse noise pixels, and then incorporate it into the classical bilateral filter to form ASTC, aiming to reduce the mixture of the most two common types of noises - Gaussian and impulse noises in spatial and temporal directions. After noise removal, we enhance the video contrast with APMF based on the statistical information of frame segmentation results. The experiment results demonstrate that, for diverse low-quality videos corrupted by mixed noise, underexposure, overexposure, or any mixture of the above, the proposed system can automatically produce satisfactory results

Stabilization of Deterministically Chaotic Systems by Interference and Quantum Measurements: The Ikeda Map Case

We propose a method which can effectively stabilize fixed points in the classical and quantum dynamics of a phase-sensitive chaotic system with feedback. It is based on feeding back a selected quantum sub-ensemble whose phase and amplitude stabilize the otherwise chaotic dynamics. Although the method is rather general, we apply it to realizations of the inherently chaotic Ikeda map. One suggested realization involves the Mach-Zender interferometer with Kerr nonlinearity. Another realization involves a trapped ion interacting with laser fields.Comment: RevTeX, 5 pages, two figure

Over or under-detection? A comparison of exercise and eucapnic voluntary hyperpnoea challenges in the evaluation of exercise-induced bronchoconstriction

Background: The most appropriate objective bronchoprovocation challenge in the evaluation of exercise-induced bronchoconstriction (EIB) remains debated. Standardising minute ventilation and environmental conditions during an exercise challenge test (EX) is challenging, whereas it has recently been proposed that eucapnic voluntary hyperpnoea (EVH) may be overly sensitive. The primary aim of this study was therefore to compare the airway response to EX in a dry environment (25% RH) and EVH. An evaluation of current and revised diagnostic thresholds was undertaken to determine the impact of any proposed modification to EIB screening outcome. Methods: In randomised order, sixty-three recreational athletes (male: n = 47) (training 9 ± 4 hrs/week) attended the laboratory on two separate occasions to complete either an EX challenge (6-min high-intensity cycling exercise at >80% max heart rate) in an environmental chamber (16oC, 25% relative humidity), and a EVH challenge (6-min maximal ventilation of a dry compressed gas mixture: 21% O2, 5% CO2, N2 balanced). Spirometry was performed at baseline and 3, 5, 7, 10 and 15 minutes post challenge test in accordance with international guidelines. A positive diagnosis was defined by ≥10% fall in FEV1 at two consecutive time-points for both EX and EVH and ≥15% fall in FEV1 at one time-point for EVH. Results: The mean fall in lung function following EVH (-7.9 ± 6.9%) was greater in comparison to EX (-1.9 ± 7.1; P15% FEV1 fall following EVH, of which four were positive to EX. Conclusion: Our findings indicate that EVH consistently induces a greater fall in FEV1 in comparison to EX. Applying a 10% fall in FEV1 cut-off for EVH results in greater diagnostic sensitivity, whereas a 15% fall in FEV1 cut-off improves diagnostic specificity. Future population-based research evaluating the normative response to indirect bronchoprovocation in athletes remains a priority