A method for evaluating MPSK performance using a (M/2)PSK signal set

As data rate demands on existing satellite systems increase, the need to evaluate more bandwidth efficient modulation schemes such as M-ary phase Shift Keying (MPSK) becomes important. However, the unavailability of higher order modems operational at higher data rates and the construction of such a complex device for testing purposes can make evaluation difficult. In support of NASA grant NAG 5-1491, New Mexico State University has developed a method of evaluating the performance of 8PSK in a satellite channel using a QPSK signal set. This paper will discuss this technique and will generalize the results to the use of any (M/2)PSK signal set to evaluate MPSK modulation. Verification by both computer simulation and hardware implementation will also be discussed

Stochastic to deterministic crossover of fractal dimension for a Langevin equation

Using algorithms of Higuchi and of Grassberger and Procaccia, we study numerically how fractal dimensions cross over from finite-dimensional Brownian noise at short time scales to finite values of deterministic chaos at longer time scales for data generated from a Langevin equation that has a strange attractor in the limit of zero noise. Our results suggest that the crossover occurs at such short time scales that there is little chance of finite-dimensional Brownian noise being incorrectly identified as deterministic chaos.Comment: 12 pages including 3 figures, RevTex and epsf. To appear Phys. Rev. E, April, 199

The cost of reducing starting RNA quantity for Illumina BeadArrays: a bead-level dilution experiment.

BACKGROUND: The demands of microarray expression technologies for quantities of RNA place a limit on the questions they can address. As a consequence, the RNA requirements have reduced over time as technologies have improved. In this paper we investigate the costs of reducing the starting quantity of RNA for the Illumina BeadArray platform. This we do via a dilution data set generated from two reference RNA sources that have become the standard for investigations into microarray and sequencing technologies. RESULTS: We find that the starting quantity of RNA has an effect on observed intensities despite the fact that the quantity of cRNA being hybridized remains constant. We see a loss of sensitivity when using lower quantities of RNA, but no great rise in the false positive rate. Even with 10 ng of starting RNA, the positive results are reliable although many differentially expressed genes are missed. We see that there is some scope for combining data from samples that have contributed differing quantities of RNA, but note also that sample sizes should increase to compensate for the loss of signal-to-noise when using low quantities of starting RNA. CONCLUSIONS: The BeadArray platform maintains a low false discovery rate even when small amounts of starting RNA are used. In contrast, the sensitivity of the platform drops off noticeably over the same range. Thus, those conducting experiments should not opt for low quantities of starting RNA without consideration of the costs of doing so. The implications for experimental design, and the integration of data from different starting quantities, are complex.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are

A Resident Retreat with Emergency Medicine Specific Mindfulness Training Significantly Reduces Burnout and Perceived Stress

Introduction: We hypothesize that a resident retreat with mindfulness training tailored for Emergency Medicine (EM) physicians can significantly reduce levels of burnout and perceived stress in EM residents. Methods: We conducted an intervention study of 60 EM residents undergoing an annual resident retreat with a 2.5-hour mindfulness training. The retreat was a department-funded 2-day off-site experience with a wellness theme. The training was developed and delivered by an EM physician (JO\u27S) who is a Mindfulness-Based Stress Reduction (MBSR) teacher trainee, and a certified MBSR teacher (MD). The training focused on techniques that can be used on shift, such as mindful breathing, handwashing, eating/drinking, walking, and anchoring before resuscitations. The cohort contained an equal distribution of 1st, 2nd and 3rd year residents who received a financial incentive. The subjects completed the Maslach Burnout Inventory, Perceived Stress Scale and Mindful Attention and Awareness Scale at three time points: Time 1 - one month prior, Time 2 – one week post, Time 3 – one month post. Results: The subjects were 60 EM residents (54% Male, 46% Female) with an average age of 29. Completion rates at the three time points were 70% (n = 42), 60% (n = 36) and 50% (n = 30) respectively. We found that Perceived Stress (ω2 = 0.15, p \u3c 0.01) and Emotional Exhaustion (ω2 = 0.21, p \u3c 0.01) decreased significantly over time in a linear progression across the three sampling periods. Though mindfulness as a trait did not change significantly during the study period, in the month after the retreat, 64% of resident respondents at Time 3 (n = 32) reported using the mindfulness techniques learned from the training at least 2 or 3 times a week on shift and 52% (n = 31) reported using them at least 2 or 3 times a week at home. Conclusions: An EM resident retreat that included an EM specific mindfulness training significantly reduced perceived stress and emotional exhaustion. The learned mindfulness skills were readily adopted for use on shift. Further studies should investigate effectiveness of mindfulness training outside of the retreat format. Other wellness / academic activities that occur within the socially supportive milieu of a retreat could lead to the same significant reduction in burnout and perceived stress seen in the current study

The Monitoring and Assessment Plan (MAP) Greater Everglades Wetlands Module- Landscape Pattern- Ridge, Slough, and Tree Island Mosaics: Year 1 Annual Report

In the current managed Everglades system, the pre-drainage, patterned mosaic of sawgrass ridges, sloughs and tree islands has been substantially altered or reduced largely as a result of human alterations to historic ecological and hydrological processes that sustained landscape patterns. The pre-compartmentalization ridge and slough landscape was a mosaic of sloughs, elongated sawgrass ridges (50-200m wide), and tree islands. The ridges and sloughs and tree islands were elongated in the direction of the water flow, with roughly equal area of ridge and slough. Over the past decades, the ridge-slough topographic relief and spatial patterning have degraded in many areas of the Everglades. Nutrient enriched areas have become dominated by Typha with little topographic relief; areas of reduced flow have lost the elongated ridge-slough topography; and ponded areas with excessively long hydroperiods have experienced a decline in ridge prevalence and shape, and in the number of tree islands (Sklar et al. 2004, Ogden 2005)

Chaste: an open source C++ library for computational physiology and biology

Chaste - Cancer, Heart And Soft Tissue Environment - is an open source C++ library for the computational simulation of mathematical models developed for physiology and biology. Code development has been driven by two initial applications: cardiac electrophysiology and cancer development. A large number of cardiac electrophysiology studies have been enabled and performed, including high performance computational investigations of defibrillation on realistic human cardiac geometries. New models for the initiation and growth of tumours have been developed. In particular, cell-based simulations have provided novel insight into the role of stem cells in the colorectal crypt. Chaste is constantly evolving and is now being applied to a far wider range of problems. The code provides modules for handling common scientific computing components, such as meshes and solvers for ordinary and partial differential equations (ODEs/PDEs). Re-use of these components avoids the need for researchers to "re-invent the wheel" with each new project, accelerating the rate of progress in new applications. Chaste is developed using industrially-derived techniques, in particular test-driven development, to ensure code quality, re-use and reliability. In this article we provide examples that illustrate the types of problems Chaste can be used to solve, which can be run on a desktop computer. We highlight some scientific studies that have used or are using Chaste, and the insights they have provided. The source code, both for specific releases and the development version, is available to download under an open source Berkeley Software Distribution (BSD) licence at http://www.cs.ox.ac.uk/chaste, together with details of a mailing list and links to documentation and tutorials

Sharpening the predictions of big-bang nucleosynthesis

Motivated by the recent measurement of the primeval abundance of deuterium, we re-examine the nuclear inputs to big-bang nucleosynthesis (BBN). Using Monte-Carlo realization of the nuclear cross-section data to directly estimate the theoretical uncertainties for the yields of D, 3-He and 7-Li, we show that previous estimates were a factor of 2 too large. We sharpen the BBN determination of the baryon density based upon deuterium, rho_B = (3.6 +/- 0.4) * 10^{-31} g/cm^3 (Omega_B h^2 = 0.019 +/- 0.0024), which leads to a predicted 4-He abundance, Y_P = 0.246 +/- 0.0014 and a stringent limit to the equivalent number of light neutrino species: N_nu < 3.20 (all at 95% cl). The predicted 7-Li abundance, 7-Li/H = (3.5 + 1.1 - 0.9) * 10^{-10}, is higher than that observed in pop II stars, (1.7 +/- 0.3) * 10^{-10} (both, 95% cl). We identify key reactions and the energies where further work is needed.Comment: 5 pages, 4 figures (epsfig), REVTeX; submitted to Phys. Rev. Let

Metabolism of Nonesterified and Esterified Hydroxycinnamic Acids in Red Wines by Brettanomyces bruxellensis

While Brettanomyces can metabolize nonesterified hydroxycinnamic acids found in grape musts/wines (caffeic, p-coumaric, and ferulic acids), it was not known whether this yeast could utilize the corresponding tartaric acid esters (caftaric, p-coutaric, and fertaric acids, respectively). Red wines from Washington and Oregon were inoculated with B. bruxellensis, while hydroxycinnamic acids were monitored by HPLC. Besides consuming p-coumaric and ferulic acids, strains I1a, B1b, and E1 isolated from Washington wines metabolized 40−50% of caffeic acid, a finding in contrast to strains obtained from California wines. Higher molar recoveries of 4-ethylphenol and 4-ethylguaiacol synthesized from p-coumaric and ferulic acids, respectively, were observed in Washington Cabernet Sauvignon and Syrah but not Merlot. This finding suggested that Brettanomyces either (a) utilized vinylphenols formed during processing of some wines or (b) metabolized other unidentified phenolic precursors. None of the strains of Brettanomyces studied metabolized caftaric or p-coutaric acids present in wines from Washington or Oregon.Keywords: Volatile phenols, Cinnamates, Hydroxycinnamic acids, Brettanomyces, Phenolic acidsKeywords: Volatile phenols, Cinnamates, Hydroxycinnamic acids, Brettanomyces, Phenolic acid