Resonant Bend Loss in Leakage Channel Fibers

Leakage channel fibers, designed to suppress higher-order modes, demonstrate resonant power loss at certain critical radii of curvature. Outside the resonance, the power recovers to the levels offset by the usual mechanism of bend-induced loss. Using C$^2$-imaging, we experimentally characterize this anomaly and identify the corresponding physical mechanism as the radiative decay of the fundamental mode mediated by the resonant coupling to a cladding mode.Comment: 3 pages, 4 figures, submitted to Optics Letter

A key to selected rockfishes (Sebastes spp.) based on mitochondrial DNA restriction fragment analysis

Larval and juvenile rockfishes (Sebastes spp.) are difficult to identify using morphological characters. We developed a key based on sizes of restriction endonuclease fragments of the NADH dehydrogenase-3 and -4 (ND3/ND4) and 12S and 16S ribosomal RNA (12S/16S) mitochondrial regions. The key makes use of variation in the ND3/ND4 region. Restriction endonuclease Dde I variation can corroborate identifications, as can 12S/16S variation. The key, based on 71 species, includes most North American taxa, several Asian species, and Sebastolobus alascanus and Helicolenus hilgendorfi that are closely related to rockfishes. Fifty-eight of 71 rockfish species in our database can be distinguished unequivocally, using one to five restriction enzymes; identities of the remaining species are narrowed to small groups: 1) S. polyspinis, S. crameri, and S. ciliatus or variabilis (the two species could not be distinguished and were considered as a single species) ; 2) S. chlorostictus, S. eos, and S. rosenblatti; 3) S. entomelas and S. mystinus; 4)S. emphaeus, S. variegatus, and S. wilsoni; and 5) S. carnatus and S. chrysomelas

Thermally assisted adiabatic quantum computation

We study the effect of a thermal environment on adiabatic quantum computation using the Bloch-Redfield formalism. We show that in certain cases the environment can enhance the performance in two different ways: (i) by introducing a time scale for thermal mixing near the anticrossing that is smaller than the adiabatic time scale, and (ii) by relaxation after the anticrossing. The former can enhance the scaling of computation when the environment is superohmic, while the latter can only provide a prefactor enhancement. We apply our method to the case of adiabatic Grover search and show that performance better than classical is possible with a superohmic environment, with no a priori knowledge of the energy spectrum.Comment: 4 pages, 2 figures, Final version to appear in PR

Self-similar impulsive capillary waves on a ligament

We study the short-time dynamics of a liquid ligament, held between two solid cylinders, when one is impulsively accelerated along its axis. A set of one-dimensional equations in the slender-slope approximation is used to describe the dynamics, including surface tension and viscous effects. An exact self-similar solution to the linearized equations is successfully compared to experiments made with millimetric ligaments. Another non-linear self-similar solution of the full set of equations is found numerically. Both the linear and non-linear solutions show that the axial depth at which the liquid is affected by the motion of the cylinder scales like $\sqrt{t}$. The non-linear solution presents the peculiar feature that there exists a maximum driving velocity $U^\star$ above which the solution disappears, a phenomenon probably related to the de-pinning of the contact line observed in experiments for large pulling velocities

A new microscopic nucleon-nucleon interaction derived from relativistic mean field theory

A new microscopic nucleon-nucleon (NN) interaction has been derived for the first time from the popular relativistic mean field theory (RMFT) Lagrangian. The NN interaction so obtained remarkably relate to the inbuilt fundamental parameters of RMFT. Furthermore, by folding it with the RMFT-densities of cluster and daughter nuclei to obtain the optical potential, it's application is also examined to study the exotic cluster radioactive decays, and results obtained found comparable with the successfully used M3Y phenomenological effective NN interactions. The presently derived NN-interaction can also be used to calculate a number of other nuclear observables.Comment: 4 Pages 2 Figure

CSF evidence of pericyte damage in Alzheimer's disease is associated with markers of blood-brain barrier dysfunction and disease pathology

BACKGROUND: We aimed to assess the relationship between levels of a cerebrospinal fluid (CSF) marker of pericyte damage, soluble platelet-derived growth factor receptor β (sPDGFRβ) and CSF markers of blood-brain barrier (BBB) integrity (CSF albumin and CSF/serum albumin ratio) and disease pathology (reduced CSF Aβ42 and elevated CSF total and phosphorylated tau) in Alzheimer’s disease (AD). METHODS: sPDGFRβ and albumin were measured by sandwich ELISA in ante-mortem CSF from 39 AD and 39 age-matched controls that were grouped according to their biomarker profile (i.e. AD cases t-tau > 400 pg/mL, p-tau > 60 pg/mL and Aβ42 < 550 pg/mL). sPDGFRβ was also measured in matched serum and CSF samples (n = 23) in a separate neurologically normal group for which the CSF/serum albumin ratio had been determined. RESULTS: CSF sPDGFRβ level was significantly increased in AD (p = 0.0038) and correlated positively with albumin (r = 0.45, p = 0.007), total tau (r = 0.50, p = 0.0017) and phosphorylated tau (r = 0.41, p = 0.013) in AD but not in controls. CSF sPDGFRβ did not correlate with Aβ42. Serum and CSF sPDGFRβ were positively correlated (r = 0.547, p = 0.0085) in the independent neurologically normal CSF/serum matched samples. CONCLUSIONS: We provide further evidence of an association between pericyte injury and BBB breakdown in AD and novel evidence that a CSF marker of pericyte injury is related to the severity of AD pathology

Nonequilibrium Microscopic Distribution of Thermal Current in Particle Systems

A nonequilibrium distribution function of microscopic thermal current is studied by a direct numerical simulation in a thermal conducting steady state of particle systems. Two characteristic temperatures of the thermal current are investigated on the basis of the distribution. It is confirmed that the temperature depends on the current direction; Parallel temperature to the heat-flux is higher than antiparallel one. The difference between the parallel temperature and the antiparallel one is proportional to a macroscopic temperature gradient.Comment: 4 page

Power Factor Correction Using Bridgeless Boost Topology

Power quality is becoming a major concern for many electrical users. The high power non linear loads (such as adjustable speed drives, arc furnace, static power converter etc) and low power loads (such as computer, fax machine etc) produce voltage fluctuations, harmonic currents and an inequality in network system which results into low power factor operation of the power system. The devices commonly used in industrial, commercial and residential applications need to go through rectification for their proper functioning and operation. Due to the increasing demand of these devices, the line current harmonics create a major problem by degrading the power factor of the system thus affecting the performance of the devices. Hence there is a need to reduce the input line current harmonics so as to improve the power factor of the system. This has led to designing of Power Factor Correction circuits. Power Factor Correction (PFC) involves two techniques, Active PFC and Passive PFC. An active power factor circuit using Boost Converter is used for improving the power factor. This thesis work analyzes the procedural approach and benefits of applying Bridgeless Boost Topology for improving the power factor over Boost Converter Topology. A traditional design methodology Boost Converter Topology is initially analyzed and compared with the Bridgeless Boost topology and the overall Power Factor (PF) can be improved to the expectation. Method of re-shaping the input current waveform to be similar pattern as the sinusoidal input voltage is done by the Boost converter and the related controls that act as a Power Factor Correction (PFC) circuit. Higher efficiency can be achieved by using the Bridgeless Boost Topology. In this paper simulation of Boost Converter topology and Bridgeless PFC boost Converter is presented. Performance comparisons between the conventional PFC boost Converter and the Bridgeless PFC Boost Converter is done

Qualitative evidence syntheses : assessing the relative contributions of multi‐context and single‐context reviews

Aims To examine the strengths and weaknesses of multi‐context (international) qualitative evidence syntheses in comparison with single‐context (typically single‐country) reviews. We compare a multi‐country synthesis with single‐context syntheses on facility‐based delivery in Nigeria and Kenya. Design Discussion Paper. Background Qualitative evidence increasingly contributes to decision‐making. International organisations commission multi‐context reviews of qualitative evidence to gain a comprehensive picture of similarities and differences across comparable (e.g. low‐ and middle‐income) countries. Such syntheses privilege breadth over contextual detail, risking inappropriate interpretation and application of review findings. Decision‐makers value single‐context syntheses that account for the contexts of their populations and health services. We explore how findings from multi‐ and single‐context syntheses contribute against a conceptual framework (adequacy, coherence, methodological limitations and relevance) that underpins the GRADE Confidence in Evidence of Reviews of Qualitative Evidence approach. Data sources Included studies and findings from a multi‐context qualitative evidence synthesis (2001‐2013) and two single‐context syntheses (Nigeria, 2006‐2017; and Kenya, 2002‐2016; subsequently, updated and revised). Findings Single‐context reviews contribute cultural, ethnic and religious nuances as well as specific health system factors (e.g. use of a voucher system). Multi‐context reviews contribute to universal health concerns and to generic health system concerns (e.g. access and availability). Implications for nursing: Nurse decision‐makers require relevant, timely and context‐sensitive evidence to inform clinical and managerial decision‐making. This discussion paper informs future commissioning and use of multi‐ and single‐context qualitative evidence syntheses. Conclusion Multi‐ and single‐context syntheses fulfil complementary functions. Single‐context syntheses add nuances not identifiable within the remit and timescales of a multi‐context review

Organized condensation of worm-like chains

We present results relevant to the equilibrium organization of DNA strands of arbitrary length interacting with a spherical organizing center, suggestive of DNA-histone complexation in nucleosomes. We obtain a rich phase diagram in which a wrapping state is transformed into a complex multi-leafed, rosette structure as the adhesion energy is reduced. The statistical mechanics of the "melting" of a rosette can be mapped into an exactly soluble one-dimensional many-body problem.Comment: 15 pages, 2 figures in a pdf fil