Optical encryption interface

An analog optical encryption system based on phase scrambling of two-dimensional optical images and holographic transformation for achieving large encryption keys and high encryption speed. An enciphering interface uses a spatial light modulator for converting a digital data stream into a two dimensional optical image. The optical image is further transformed into a hologram with a random phase distribution. The hologram is converted into digital form for transmission over a shared information channel. A respective deciphering interface at a receiver reverses the encrypting process by using a phase conjugate reconstruction of the phase scrambled hologram

Detector Efficiency Limits on Quantum Improvement

Although the National Institute of Standards and Technology has measured the intrinsic quantum efficiency of Si and InGaAs APD materials to be above 98 % by building an efficient compound detector, commercially available devices have efficiencies ranging between 15 % and 75 %. This means bandwidth, dark current, cost, and other factors are more important than quantum efficiency for existing applications. This paper systematically examines the generic detection process, lays out the considerations needed for designing detectors for non-classical applications, and identifies the ultimate physical limits on quantum efficiency.Comment: LaTeX, 7 pages, 3 figure

Quantifying the Role of Adverse Events in the Mortality Difference between First and Second-Generation Antipsychotics in Older Adults: Systematic Review and Meta-Synthesis

Background: Observational studies have reported higher mortality among older adults treated with first-generation antipsychotics (FGAs) versus second-generation antipsychotics (SGAs). A few studies examined risk for medical events, including stroke, ventricular arrhythmia, venous thromboembolism, myocardial infarction, pneumonia, and hip fracture. Objectives: 1) Review robust epidemiologic evidence comparing mortality and medical event risk between FGAs and SGAs in older adults; 2) Quantify how much these medical events explain the observed mortality difference between FGAs and SGAs. Data sources Pubmed and Science Citation Index. Study eligibility criteria, participants, and interventions Studies of antipsychotic users that: 1) evaluated mortality or medical events specified above; 2) restricted to populations with a mean age of 65 years or older 3) compared FGAs to SGAs, or both to a non-user group; (4) employed a “new user” design; (5) adjusted for confounders assessed prior to antipsychotic initiation; (6) and did not require survival after antipsychotic initiation. A separate search was performed for mortality estimates associated with the specified medical events. Study appraisal and synthesis methods For each medical event, we used a non-parametric model to estimate lower and upper bounds for the proportion of the mortality difference—comparing FGAs to SGAs—mediated by their difference in risk for the medical event. Results: We provide a brief, updated summary of the included studies and the biological plausibility of these mechanisms. Of the 1122 unique citations retrieved, we reviewed 20 observational cohort studies that reported 28 associations. We identified hip fracture, stroke, myocardial infarction, and ventricular arrhythmias as potential intermediaries on the causal pathway from antipsychotic type to death. However, these events did not appear to explain the entire mortality difference. Conclusions: The current literature suggests that hip fracture, stroke, myocardial infarction, and ventricular arrhythmias partially explain the mortality difference between SGAs and FGAs

Effect of aging in functional redox state of single isolated skeletal muscle fibres

[EN] Skeletal muscle constantly produces reactive oxygen species (ROS). During contractile activity ROS are generated in skeletal muscle fibres. There is considerable support for an involvement of ROS in the process of aging. Several studies indicate that adaptive responses of skeletal muscle that are activated and regulated by ROS are disrupted during aging. The aim of this study was to monitor, in real time, intracellular ROS production in single skeletal muscle fibres from old and young mice and study the effect of contractile activity in these cells. Following evaluate and correlate the potential changes in intracellular ROS production with glutathione redox state and antioxidant enzymatic activities in muscle. Single skeletal muscle fibres were isolated from the Flexor Digitorus Brevis muscle from young (2-4 monthold) and old (26-28 month-old) C57BL/6 mice. Fibres were loaded with DCFH-DA, a fluorophore probe that allows the quantification of intracellular ROS generation by fluorescence microscopy imaging. Contractile activity was induced in fibres by electrical stimulation. Glutathione redox state and activity of antioxidant enzymes were analysed in gastrocnemious muscle. Intracellular basal level of ROS was higher in fibres from old mice. Contractile activity induced increase of ROS generation in fibres from young mice. However, this response was attenuated in fibres from old mice. Glutathione redox state was significant different, in favour of oxidized glutathione, in muscles from old mice. Glutathione peroxidase and catalase activities were significantly augmented in muscles from old mice. In conclusion, the process of aging modifies the basal redox status in skeletal muscle fibres in favour of oxidation and induces adaptation mechanisms of antioxidant defences. These are not able to neutralize the increase of basal oxidation, but they might lead to the attenuation of ROS produced by contractile activity observed in fibres from old mice

Dexmedetomidine improves success of paediatric MRI sedation

OBJECTIVE: To improve success rates of children requiring sedation for MRI. METHODS: Audits of sedation success for children attending planned MRI using three different approaches: (1) National Institute for Health and Care Excellence (NICE) guidance (chloral hydrate if <15 kg and oral midazolam if ≥15 kg), (2) Chloral hydrate for all patients, (3) Chloral hydrate±intranasal dexmedetomidine if <15 kg and intranasal dexmedetomidine alone if ≥15 kg. RESULTS: 74 patients had 85 MRI scan attempts. Overall success rates were significantly higher when using intranasal dexmedetomidine compared with following NICE guidance (81% vs 52% p=0.017). Dexmedetomidine performed better than oral midazolam for the same indication (76% vs 33% p=0.026). The side effect profile for dexmedetomidine was as reported in larger studies. CONCLUSIONS: Intranasal dexmedetomidine is an effective alternative to oral midazolam for sedation for MRI and as a rescue medication where chloral hydrate has been ineffective

Melatonin for rapid eye movement sleep behavior disorder in Parkinson's disease : a randomised controlled trial

Background Melatonin may reduce REM-sleep behavior disorder (RBD) symptoms in Parkinson's disease (PD), though robust clinical trials are lacking. Objective To assess the efficacy of prolonged-release (PR) melatonin for RBD in PD. Methods Randomized, double-blind, placebo-controlled, parallel-group trial with an 8-week intervention and 4-week observation pre- and postintervention (ACTRN12613000648729). Thirty PD patients with rapid eye movement sleep behavior disorder were randomized to 4 mg of prolonged-release melatonin (Circadin) or matched placebo, ingested orally once-daily before bedtime. Primary outcome was the aggregate of rapid eye movement sleep behavior disorder incidents averaged over weeks 5 to 8 of treatment captured by a weekly diary. Data were included in a mixed-model analysis of variance (n = 15 per group). Results No differences between groups at the primary endpoint (3.4 events/week melatonin vs. 3.6 placebo; difference, 0.2; 95% confidence interval = -3.2 to 3.6; P = 0.92). Adverse events included mild headaches, fatigue, and morning sleepiness (n = 4 melatonin; n = 5 placebo). Conclusion Prolonged-release melatonin 4 mg did not reduce rapid eye movement sleep behavior disorder in PD. (c) 2019 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society

HPV16 E1^E4 protein is phosphorylated by Cdk2/cyclin A and relocalizes this complex to the cytoplasm

AbstractThe human papillomavirus type 16 E1^E4 protein is expressed abundantly in cells supporting viral DNA amplification, but its expression is lost during malignant progression. In cell culture, 16E1^E4 causes G2 cell cycle arrest by associating with and preventing the nuclear entry of Cdk1/cyclin B1 complexes. Here, we show that 16E1^E4 is also able to associate with cyclin A and Cdk2 during the G2 phase of the cell cycle. Only a weak association was apparent during S-phase, and progression through S-phase appeared unaffected. As with cyclin B1, the interaction of 16E1^E4 with cyclin A is dependent on residues T22/T23 and results in the accumulation of cyclin A in the cytoplasm where it colocalizes with 16E1^E4. 16E1^E4 serine 32 was found to be phosphorylated by Cdk2/cyclin A. We hypothesize that the interaction of 16E1^E4 with cyclin A may serve to increase the efficiency with which 16E1^E4 is able to prevent mitotic entry

CIV 1549 as an Eigenvector 1 Parameter for Active Galactic Nuclei

[Abridged] We have been exploring a spectroscopic unification for all known types of broad line emitting AGN. The 4D Eigenvector 1 (4DE1) parameter space shows promise as a unification capable of organizing quasar diversity on a sequence primarily governed by Eddington ratio. This paper considers the role of CIV 1549 measures with special emphasis on the CIV 1549 line shift as a principal 4DE1 diagnostic. We use HST archival spectra for 130 sources with S/N high enough to permit reliable CIV 1549 broad component (BC) measures. We find a CIV 1549 BC profile blueshift that is strongly concentrated among (largely radio-quiet: RQ) sources with FWHM(H beta BC) < 4000 km/s (which we call Population A). Narrow line Seyfert 1 (NLSy1, with FWHM H beta < 2000 km/s) sources belong to this population but do not emerge as a distinct class. The systematic blueshift, widely interpreted as arising in a disk wind/outflow, is not observed in broader lined AGN which we call Population B. We find new correlations between FWHM(CIV 1549 BC) and CIV 1549 line shift as well as the equivalent width of CIV 1549. They are seen only in Pop. A sources. CIV 1549 measures enhance the apparent dichotomy at FWHM(Hbeta BC) approx. 4000 \kms\ (Sulentic et al. 2000) suggesting that it has more significance in the context of Broad Line Region structure than the more commonly discussed RL vs. RQ dichotomy. Black hole masses computed from FWHM CIV 1549 BC for about 80 AGN indicate that the CIV 1549 width is a poor virial estimator. Comparison of mass estimates derived from Hbeta BC and CIV 1549 reveals that the latter show different and nonlinear offsets for population A and B sources. A significant number of sources also show narrow line CIV 1549 emission. We present a recipe for CIV 1549 narrow component extraction.Comment: Accepted for publication in the Astrophysical Journa