A 2+1-Dimensional Non-Isothermal Magnetogasdynamic System. Hamiltonian-Ermakov Integrable Reduction

A 2+1-dimensional anisentropic magnetogasdynamic system with a polytropic gas law is shown to admit an integrable elliptic vortex reduction when $\gamma=2$ to a nonlinear dynamical subsystem with underlying integrable Hamiltonian-Ermakov structure. Exact solutions of the magnetogasdynamic system are thereby obtained which describe a rotating elliptic plasma cylinder. The semi-axes of the elliptical cross-section, remarkably, satisfy a Ermakov-Ray-Reid system

A Non-Isothermal Spinning Magneto-gasdynamic Cloud System A Hamiltonian-Ermakov Integrable Reduction

A 2+1-dimensional magneto-gasdynamic version of a gas cloud system originating in work of Ovsiannikov and Dyson is shown, when adiabatic index $\gamma = 2$, to admit an integrable reduction to a subsystem with underlying Hamiltonian-Ermakov structure. A class of exact solutions of the original nonlinear magneto-gasdynamic system is thereby constructed

Rough paths in idealized financial markets

This paper considers possible price paths of a financial security in an idealized market. Its main result is that the variation index of typical price paths is at most 2, in this sense, typical price paths are not rougher than typical paths of Brownian motion. We do not make any stochastic assumptions and only assume that the price path is positive and right-continuous. The qualification "typical" means that there is a trading strategy (constructed explicitly in the proof) that risks only one monetary unit but brings infinite capital when the variation index of the realized price path exceeds 2. The paper also reviews some known results for continuous price paths and lists several open problems.Comment: 21 pages, this version adds (in Appendix C) a reference to new results in the foundations of game-theoretic probability based on Hardin and Taylor's work on hat puzzle

Free flap donor site during early review consultations: is it really an issue?

Donor site complications, following microvascular free tissue transfer, can limit recovery in patients treated for head and neck cancer, with a curative intent. The Patient Concerns Inventory (PCI-HN) is a prompt list that provides patients with repeated opportunities to raise issues they feel are important and want to discuss. Here, we look at baseline results from a cluster preference randomised control trial with consultants either “using” or “not using” the PCI package in clinic to identify patient concerns. UWQOL results were presented from 67 consecutive patients having reconstruction with free tissue transfer and PCI results from 25 of these patients in the PCI arm of the trial. During early review consultations patients most wanted to discuss issues related to dental health, dry mouth, and chewing. Donor site morbidity, in our patient sample, did not appear to be an issue that patients wanted to discuss

Review of HaNDLE-on-QoL: a database of published papers that use questionnaires to report quality of life in patients with cancer of the head and neck

HaNDLE-on-QoL (Head And Neck Database Listing Evidence on QoL) is a searchable database that comprises abstracts of papers that have used questionnaires to report on quality of life (QoL) in patients with cancer of the head and neck. It can be searched by title, first author, year of publication, words used in the abstract, site of cancer, study design, and questionnaires used. The aim of this paper was to summarise its contents. In May 2017 we searched the website using the criteria above. It contained 1498 papers (including 149 reviews), and the number is increasing each year. Most studies concerned a combination of subsites in the head and neck (n = 871); 180 focused specifically on oral sites, and 109 on the larynx. The commonest topics were swallowing (n = 353), speech (n = 299), pain (n = 292), emotions (n = 226), and depression (n = 193). Nearly all the papers concerned function or predictors of health-related QoL (HRQoL), but 98 were clinical or randomised controlled trials. The site included over 250 questionnaires of which the most common were the European Organisation for Research and Treatment of Cancer C30 (EORTC-C30, n = 369), the EORTC-head and neck 35 (EORTC H & N35, n = 353), and the University of Washington Quality of Life (UWQoL) (n = 276). HaNDLE-on-QoL highlights the complexity of QoL after treatment and the diversity and range of the studies. It is a useful point of reference for those involved in clinical practice or research

Crustacean remains from the Yuka mammoth raise questions about non-analogue freshwater communities in the Beringian region during the Pleistocene

This work is licensed under a Creative Commons Attribution 4.0 International License.Frozen permafrost Pleistocene mammal carcasses with soft tissue remains are subject to intensive study and help elucidate the palaeoenvironment where these animals lived. Here we present an inventory of the freshwater fauna and flora found in a sediment sample from the mummified Woolly Mammoth carcass found in August 2010, from the Oyogos Yar coast near the Kondratievo River in the Laptev Sea region, Sakha (Yakutia) Republic, NE Russia. Our study demonstrates that the waterbody where the carcass was buried could be characterized as a shallow pond or lake inhabited mainly by taxa which are present in this area today, but additionally by some branchiopod crustacean taxa currently absent or unusual in the region although they exist in the arid zone of Eurasia (steppes and semi-deserts). These findings suggest that some “non-analogue” crustacean communities co-existed with the “Mammoth fauna”. Our findings raise questions about the nature of the waterbodies that existed in Beringia during the MIS3 climatic optimum when the mammoth was alive

Galactic Globular and Open Clusters in the Sloan Digital Sky Survey. II. Test of Theoretical Stellar Isochrones

We perform an extensive test of theoretical stellar models for main-sequence stars in ugriz, using cluster fiducial sequences obtained in the previous paper of this series. We generate a set of isochrones using the Yale Rotating Evolutionary Code (YREC) with updated input physics, and derive magnitudes and colors in ugriz from MARCS model atmospheres. These models match cluster main sequences over a wide range of metallicity within the errors of the adopted cluster parameters. However, we find a large discrepancy of model colors at the lower main sequence (Teff < ~4500 K) for clusters at and above solar metallicity. We also reach similar conclusions using the theoretical isochrones of Girardi et al. and Dotter et al., but our new models are generally in better agreement with the data. Using our theoretical isochrones, we also derive main-sequence fitting distances and turn-off ages for five key globular clusters, and demonstrate the ability to derive these quantities from photometric data in the Sloan Digital Sky Survey. In particular, we exploit multiple color indices (g - r, g - i, and g - z) in the parameter estimation, which allows us to evaluate internal systematic errors. Our distance estimates, with an error of sigma(m - M) = 0.03-0.11 mag for individual clusters, are consistent with Hipparcos-based subdwarf fitting distances derived in the Johnson-Cousins or Stromgren photometric systems.Comment: 26 pages, 28 figures. Accepted for publication in ApJ. Version with high resolution figures available at http://spider.ipac.caltech.edu/~deokkeun/sdss_iso.pd

Navier-Stokes Analysis of a High Wing Transport High-Lift Configuration with Externally Blown Flaps

Insights and lessons learned from the aerodynamic analysis of the High Wing Transport (HWT) high-lift configuration are presented. Three-dimensional Navier-Stokes CFD simulations using the OVERFLOW flow solver are compared with high Reynolds test data obtained in the NASA Ames 12 Foot Pressure Wind Tunnel (PWT) facility. Computational analysis of the baseline HWT high-lift configuration with and without Externally Blown Flap (EBF) jet effects is highlighted. Several additional aerodynamic investigations, such as nacelle strake effectiveness and wake vortex studies, are presented. Technical capabilities and shortcomings of the computational method are discussed and summarized

Redating the earliest evidence of the mid-Holocene relative sea-level highstand in Australia and implications for global sea-level rise.

Reconstructing past sea levels can help constrain uncertainties surrounding the rate of change, magnitude, and impacts of the projected increase through the 21st century. Of significance is the mid-Holocene relative sea-level highstand in tectonically stable and remote (far-field) locations from major ice sheets. The east coast of Australia provides an excellent arena in which to investigate changes in relative sea level during the Holocene. Considerable debate surrounds both the peak level and timing of the east coast highstand. The southeast Australian site of Bulli Beach provides the earliest evidence for the establishment of a highstand in the Southern Hemisphere, although questions have been raised about the pretreatment and type of material that was radiocarbon dated for the development of the regional sea-level curve. Here we undertake a detailed morpho- and chronostratigraphic study at Bulli Beach to better constrain the timing of the Holocene highstand in eastern Australia. In contrast to wood and charcoal samples that may provide anomalously old ages, probably due to inbuilt age, we find that short-lived terrestrial plant macrofossils provide a robust chronological framework. Bayesian modelling of the ages provide improved dating of the earliest evidence for a highstand at 6,880±50 cal BP, approximately a millennium later than previously reported. Our results from Bulli now closely align with other sea-level reconstructions along the east coast of Australia, and provide evidence for a synchronous relative sea-level highstand that extends from the Gulf of Carpentaria to Tasmania. Our refined age appears to be coincident with major ice mass loss from Northern Hemisphere and Antarctic ice sheets, supporting previous studies that suggest these may have played a role in the relative sea-level highstand. Further work is now needed to investigate the environmental impacts of regional sea levels, and refine the timing of the subsequent sea-level fall in the Holocene and its influence on coastal evolution