Optimal Alphabetic Ternary Trees

We give a new algorithm to construct optimal alphabetic ternary trees, where every internal node has at most three children. This algorithm generalizes the classic Hu-Tucker algorithm, though the overall computational complexity has yet to be determined

Comparison of five different RNA sources to examine the lactating bovine mammary gland transcriptome using RNA-Sequencing.

The objective of this study was to examine five different sources of RNA, namely mammary gland tissue (MGT), milk somatic cells (SC), laser microdissected mammary epithelial cells (LCMEC), milk fat globules (MFG) and antibody-captured milk mammary epithelial cells (mMEC) to analyze the bovine mammary gland transcriptome using RNA-Sequencing. Our results provide a comparison between different sampling methods (invasive and non-invasive) to define the transcriptome of mammary gland tissue and milk cells. This information will be of value to investigators in choosing the most appropriate sampling method for different research applications to study specific physiological states during lactation. One of the simplest procedures to study the transcriptome associated with milk appears to be the isolation of total RNA directly from SC or MFG released into milk during lactation. Our results indicate that the SC and MFG transcriptome are representative of MGT and LCMEC and can be used as effective and alternative samples to study mammary gland expression without the need to perform a tissue biopsy

Procalcitonin guided antibiotic therapy and hospitalization in patients with lower respiratory tract infections: a prospective, multicenter, randomized controlled trial

<p>Abstract</p> <p>Background:</p> <p>Lower respiratory tract infections like acute bronchitis, exacerbated chronic obstructive pulmonary disease and community-acquired pneumonia are often unnecessarily treated with antibiotics, mainly because of physicians' difficulties to distinguish viral from bacterial cause and to estimate disease-severity. The goal of this trial is to compare medical outcomes, use of antibiotics and hospital resources in a strategy based on enforced evidence-based guidelines versus procalcitonin guided antibiotic therapy in patients with lower respiratory tract infections.</p> <p>Methods and design:</p> <p>We describe a prospective randomized controlled non-inferiority trial with an open intervention. We aim to randomize over a fixed recruitment period of 18 months a minimal number of 1002 patients from 6 hospitals in Switzerland. Patients must be >18 years of age with a lower respiratory tract infections <28 days of duration. Patients with no informed consent, not fluent in German, a previous hospital stay within 14 days, severe immunosuppression or chronic infection, intravenous drug use or a terminal condition are excluded. Randomization to either guidelines-enforced management or procalcitonin-guided antibiotic therapy is stratified by centre and type of lower respiratory tract infections. During hospitalization, all patients are reassessed at days 3, 5, 7 and at the day of discharge. After 30 and 180 days, structured phone interviews by blinded medical students are conducted. Depending on the randomization allocation, initiation and discontinuation of antibiotics is encouraged or discouraged based on evidence-based guidelines or procalcitonin cut off ranges, respectively. The primary endpoint is the risk of combined disease-specific failure after 30 days. Secondary outcomes are antibiotic exposure, side effects from antibiotics, rate and duration of hospitalization, time to clinical stability, disease activity scores and cost effectiveness. The study hypothesis is that procalcitonin-guidance is non-inferior (i.e., at worst a 7.5% higher combined failure rate) to the management with enforced guidelines, but is associated with a reduced total antibiotic use and length of hospital stay.</p> <p>Discussion:</p> <p>Use of and prolonged exposure to antibiotics in lower respiratory tract infections is high. The proposed trial investigates whether procalcitonin-guidance may safely reduce antibiotic consumption along with reductions in hospitalization costs and antibiotic resistance. It will additionally generate insights for improved prognostic assessment of patients with lower respiratory tract infections.</p> <p>Trial registration:</p> <p>ISRCTN95122877</p

Dynamics of light propagation in spatiotemporal dielectric structures

Propagation, transmission and reflection properties of linearly polarized plane waves and arbitrarily short electromagnetic pulses in one-dimensional dispersionless dielectric media possessing an arbitrary space-time dependence of the refractive index are studied by using a two-component, highly symmetric version of Maxwell's equations. The use of any slow varying amplitude approximation is avoided. Transfer matrices of sharp nonstationary interfaces are calculated explicitly, together with the amplitudes of all secondary waves produced in the scattering. Time-varying multilayer structures and spatiotemporal lenses in various configurations are investigated analytically and numerically in a unified approach. Several new effects are reported, such as pulse compression, broadening and spectral manipulation of pulses by a spatiotemporal lens, and the closure of the forbidden frequency gaps with the subsequent opening of wavenumber bandgaps in a generalized Bragg reflector

A dominant magnetic dipole for the evolved Ap star candidate EK Eridani

EK Eri is one of the most slowly rotating active giants known, and has been proposed to be the descendant of a strongly magnetic Ap star. We have performed a spectropolarimetric study of EK Eri over 4 photometric periods with the aim of inferring the topology of its magnetic field. We used the NARVAL spectropolarimeter at the Bernard Lyot telescope at the Pic du Midi Observatory, along with the least-squares deconvolution method, to extract high signal-to-noise ratio Stokes V profiles from a timeseries of 28 polarisation spectra. We have derived the surface-averaged longitudinal magnetic field Bl. We fit the Stokes V profiles with a model of the large-scale magnetic field and obtained Zeeman Doppler images of the surface magnetic strength and geometry. Bl variations of up to about 80 G are observed without any reversal of its sign, and which are in phase with photometric ephemeris. The activity indicators are shown to vary smoothly on a timescale compatible with the rotational period inferred from photometry (308.8 d.), however large deviations can occur from one rotation to another. The surface magnetic field variations of EK Eri appear to be dominated by a strong magnetic spot (of negative polarity) which is phased with the dark (cool) photometric spot. Our modeling shows that the large-scale magnetic field of EK Eri is strongly poloidal. For a rotational axis inclination of i = 60{\deg}, we obtain a model that is almost purely dipolar. In the dipolar model, the strong magnetic/photometric spot corresponds to the negative pole of the dipole, which could be the remnant of that of an Ap star progenitor of EK Eri. Our observations and modeling conceptually support this hypothesis, suggesting an explanation of the outstanding magnetic properties of EK Eri as the result of interaction between deep convection and the remnant of an Ap star magnetic dipole.Comment: 8 pages, 6 figures, accepted for publication in Astronomy & Astrophysic

Comparison of collapsing methods for the statistical analysis of rare variants

Novel technologies allow sequencing of whole genomes and are considered as an emerging approach for the identification of rare disease-associated variants. Recent studies have shown that multiple rare variants can explain a particular proportion of the genetic basis for disease. Following this assumption, we compare five collapsing approaches to test for groupwise association with disease status, using simulated data provided by Genetic Analysis Workshop 17 (GAW17). Variants are collapsed in different scenarios per gene according to different minor allele frequency (MAF) thresholds and their functionality. For comparing the different approaches, we consider the family-wise error rate and the power. Most of the methods could maintain the nominal type I error levels well for small MAF thresholds, but the power was generally low. Although the methods considered in this report are common approaches for analyzing rare variants, they performed poorly with respect to the simulated disease phenotype in the GAW17 data set

Effectiveness and cost-effectiveness of an educational intervention for practice teams to deliver problem focused therapy for insomnia: rationale and design of a pilot cluster randomised trial

Background: Sleep problems are common, affecting over a third of adults in the United Kingdom and leading to reduced productivity and impaired health-related quality of life. Many of those whose lives are affected seek medical help from primary care. Drug treatment is ineffective long term. Psychological methods for managing sleep problems, including cognitive behavioural therapy for insomnia (CBTi) have been shown to be effective and cost effective but have not been widely implemented or evaluated in a general practice setting where they are most likely to be needed and most appropriately delivered. This paper outlines the protocol for a pilot study designed to evaluate the effectiveness and cost-effectiveness of an educational intervention for general practitioners, primary care nurses and other members of the primary care team to deliver problem focused therapy to adult patients presenting with sleep problems due to lifestyle causes, pain or mild to moderate depression or anxiety. Methods and design: This will be a pilot cluster randomised controlled trial of a complex intervention. General practices will be randomised to an educational intervention for problem focused therapy which includes a consultation approach comprising careful assessment (using assessment of secondary causes, sleep diaries and severity) and use of modified CBTi for insomnia in the consultation compared with usual care (general advice on sleep hygiene and pharmacotherapy with hypnotic drugs). Clinicians randomised to the intervention will receive an educational intervention (2 × 2 hours) to implement a complex intervention of problem focused therapy. Clinicians randomised to the control group will receive reinforcement of usual care with sleep hygiene advice. Outcomes will be assessed via self-completion questionnaires and telephone interviews of patients and staff as well as clinical records for interventions and prescribing. Discussion: Previous studies in adults have shown that psychological treatments for insomnia administered by specialist nurses to groups of patients can be effective within a primary care setting. This will be a pilot study to determine whether an educational intervention aimed at primary care teams to deliver problem focused therapy for insomnia can improve sleep management and outcomes for individual adult patients presenting to general practice. The study will also test procedures and collect information in preparation for a larger definitive cluster-randomised trial. The study is funded by The Health Foundation