De-Trending Time Series for Astronomical Variability Surveys

We present a de-trending algorithm for the removal of trends in time series. Trends in time series could be caused by various systematic and random noise sources such as cloud passages, changes of airmass, telescope vibration or CCD noise. Those trends undermine the intrinsic signals of stars and should be removed. We determine the trends from subsets of stars that are highly correlated among themselves. These subsets are selected based on a hierarchical tree clustering algorithm. A bottom-up merging algorithm based on the departure from normal distribution in the correlation is developed to identify subsets, which we call clusters. After identification of clusters, we determine a trend per cluster by weighted sum of normalized light-curves. We then use quadratic programming to de-trend all individual light-curves based on these determined trends. Experimental results with synthetic light-curves containing artificial trends and events are presented. Results from other de-trending methods are also compared. The developed algorithm can be applied to time series for trend removal in both narrow and wide field astronomy.Comment: Revised version according to the referee's second revie

MR Findings of Fulminent Leukoencephalopathy in EBV-Associated Hemophagocytic Syndrome

Various manifestations of brain involvement for patients with virus-associated hemophagocytic syndrome have been reported. Here, we report on the sequential magnetic resonance (MR) findings of acute demyelination of the entire brain with subsequent brain atrophy in a follow-up study of a 25-month-old boy who was admitted with fever and then diagnosed with infectious mononucleosis and EBV-associated hemophagocytic syndrome. We also review other conditions that should be included in the differential diagnosis of this disease

Investigation of β-carotene–gelatin composite particles with a multiwavelength UV/vis detector for the analytical ultracentrifuge

A multiwavelength UV/vis detector for the analytical ultracentrifuge (MWL-AUC) has been developed recently. In this work, β-carotene–gelatin composite particles are investigated with MWL-AUC. Band centrifugation with a Vinograd cell is used to ensure maximum sample separation. Spectral changes of the system are observed in dependence of the sedimentation coefficient and are attributed to a previously unknown inhomogeneity of the β-carotene chemical composition with both H- and J-aggregates coexisting in a mixture. In addition, our data suggest that pure H- and J-aggregates exist in a particle while their relative concentrations in a mixture determine the color characteristics of the sample. The unique abilities and properties of MWL-AUC include sedimentation coefficient distributions for all possible wavelengths, full UV/vis spectra of each different species in the mixture and 3D movies of the sedimentation process. These properties significantly extend the scope of the analytical ultracentrifuge technique and show that complex biopolymer multicomponent mixtures can be resolved into their individual species

Far-infrared transmission studies of c-axis oriented superconducting MgB2 thin film

We reported far-infrared transmission measurements on a c-axis oriented superconducting MgB$_{2}$ thin film in the frequency range of 30 $\sim$ 250 cm$^{-1}$. We found that these measurements were sensitive to values of scattering rate $1/\tau$ and superconducting gap $2\Delta$. By fitting the experimental transmission spectra at 40 K and below, we obtained $1/\tau =$ (700 $\sim$ 1000) cm$^{-1}$ and $2\Delta (0)\cong$ 42 cm$^{-1}$. These two quantities suggested that MgB$_{2}$ belong to the dirty limit.Comment: submitted at May

Phonon structure in I-V characteristic of MgB2_{2} point-contacts

The search of the phonon structure at the above-gap energies was carried out for $d^{2}V/dI^{2}(V)$ spectra of MgB$_{2}$ point contacts with a normal metal. The two-band model is assumed not only for the gap structure in $dV/dI(V)$-characteristics, but also for phonons in $d^{2}V/dI^{2}(V)$ point-contact spectra, with up to the maximum lattice vibration energy. Since the current is carried mostly by charges of 3D-band, whereas the strong electron-phonon interaction occurs in 2D-band, we observe the phonon peculiarities due to ''proximity'' effect in {\it k}-space, which depends on the variation of interband coupling through the elastic scattering.Comment: 6 pages, 4 figures, revtex4, reported in International Conference "Modern Problems in Superconductivity", 9-13 September, Yalta, Ukrain

Evanescent light-matter Interactions in Atomic Cladding Wave Guides

Alkali vapors, and in particular rubidium, are being used extensively in several important fields of research such as slow and stored light non-linear optics3 and quantum computation. Additionally, the technology of alkali vapors plays a major role in realizing myriad industrial applications including for example atomic clocks magentometers8 and optical frequency stabilization. Lately, there is a growing effort towards miniaturizing traditional centimeter-size alkali vapor cells. Owing to the significant reduction in device dimensions, light matter interactions are greatly enhanced, enabling new functionalities due to the low power threshold needed for non-linear interactions. Here, taking advantage of the mature Complimentary Metal-Oxide-Semiconductor (CMOS) compatible platform of silicon photonics, we construct an efficient and flexible platform for tailored light vapor interactions on a chip. Specifically, we demonstrate light matter interactions in an atomic cladding wave guide (ACWG), consisting of CMOS compatible silicon nitride nano wave-guide core with a Rubidium (Rb) vapor cladding. We observe the highly efficient interaction of the electromagnetic guided mode with the thermal Rb cladding. The nature of such interactions is explained by a model which predicts the transmission spectrum of the system taking into account Doppler and transit time broadening. We show, that due to the high confinement of the optical mode (with a mode area of 0.3{\lambda}2), the Rb absorption saturates at powers in the nW regime.Comment: 10 Pages 4 Figures. 1 Supplementar

Performance of a fast fiber based UV/Vis multiwavelength detector for the analytical ultracentrifuge

The optical setup and the performance of a prototype UV/Vis multiwavelength analytical ultracentrifuge (MWL-AUC) is described and compared to the commercially available Optima XL-A from Beckman Coulter. Slight modifications have been made to the optical path of the MWL-AUC. With respect to wavelength accuracy and radial resolution, the new MWL-AUC is found to be comparable to the existing XL-A. Absorbance accuracy is dependent on the light intensity available at the detection wavelength as well as the intrinsic noise of the data. Measurements from single flashes of light are more noisy for the MWL-AUC, potentially due to the absence of flash-to-flash normalization in the current design. However, the possibility of both wavelength and scan averaging can compensate for this and still give much faster scan rates than the XL-A. Some further improvements of the existing design are suggested based on these findings

Reversible magnetization of MgB2 single crystals with a two-gap nature

We present reversible magnetization measurements on MgB2 single crystals in magnetic fields up to 2.5 T applied parallel to the crystal's c-axis. This magnetization is analyzed in terms of the Hao-Clem model, and various superconducting parameters, such as the critical fields [Hc(0) and Hc2(0)], the characteristic lengths [xi(0) and lambda(0)], and the Ginzburg-Landau parameter, kappa, are derived. The temperature dependence of the magnetic penetration depth, lambda(T), obtained from the Hao-Clem analysis could not be explained by theories assuming a single gap. Our data are well described by using a two-gap model.Comment: 20 pages, 1 table, 4 figures, will be published in Phys. Rev.

Optimisation of medications used in residential aged care facilities: a systematic review and meta-analysis of randomised controlled trials

Background: Frail older adults living in residential aged care facilities (RACFs) usually experience comorbidities and are frequently prescribed multiple medications. This increases the potential risk of inappropriate prescribing and its negative consequences. Thus, optimising prescribed medications in RACFs is a challenge for healthcare providers. Objective: Our aim was to systematically review interventions that increase the appropriateness of medications used in RACFs and the outcomes of these interventions. Methods: Systematic review and meta-analysis of randomised control trials (RCTs) and cluster randomised control trials (cRCTs) were performed by searching specified databases (MEDLINE, PubMed, Google scholar, PsycINFO) for publications from inception to May 2019 based on defined inclusion criteria. Data were extracted, study quality was assessed and statistically analysed using RevMan v5.3. Medication appropriateness, hospital admissions, mortality, falls, quality of life (QoL), Behavioural and Psychological Symptoms of Dementia (BPSD), adverse drug events (ADEs) and cognitive function could be meta-analysed. Results: A total of 25 RCTs and cRCTs comprising 19,576 participants met the inclusion criteria. The studies tested various interventions including medication review (n = 13), staff education (n = 9), multi-disciplinary case conferencing (n = 4) and computerised clinical decision support systems (n = 2). There was an effect of interventions on medication appropriateness (RR 0.71; 95% confidence interval (CI): 0.60,0.84) (10 studies), and on medication appropriateness scales (standardised mean difference = − 0.67; 95% CI: − 0.97, − 0.36) (2 studies). There were no apparent effects on hospital admission (RR 1.00; 95% CI: 0.93, 1.06), mortality (RR 0.98; 95% CI: 0.86, 1.11), falls (RR 1.06; 95% CI: 0.89,1.26), ADEs (RR 1.04; 95% CI: 0.96,1.13), QoL (standardised mean difference = 0.16; 95% CI:-0.13, 0.45), cognitive function (weighted mean difference = 0.69; 95% CI: − 1.25, 2.64) and BPSD (RR 0.68; 95% CI: 0.44,1.06) (2 studies). Conclusion: Modest improvements in medication appropriateness were observed in the studies included in this systematic review. However, the effect on clinical measures was limited to drive strong conclusions