Analyses of mean and turbulent motion in the tropics with the use of unequally spaced data

Wind velocities from 25 km to 60 km over Ascension Island, Fort Sherman and Kwajalein for the period January 1970 to December 1971 are analyzed in order to achieve a better understanding of the mean flow, the eddy kinetic energy and the Eulerian time spectra of the eddy kinetic energy. Since the data are unequally spaced in time, techniques of one-dimensional covariance theory were utilized and an unequally spaced time series analysis was accomplished. The theoretical equations for two-dimensional analysis or wavenumber frequency analysis of unequally spaced data were developed. Analysis of the turbulent winds and the average seasonal variance and eddy kinetic energy of the turbulent winds indicated that maximum total variance and energy is associated with the east-west velocity component. This is particularly true for long period seasonal waves which dominate the total energy spectrum. Additionally, there is an energy shift for the east-west component into the longer period waves with altitude increasing from 30 km to 50 km

Characteristics of the motions, turbulence intensity, diffusivity, flux of momentum and sensible heat in the upper atmosphere

Analyses of the meteorological rocket data obtained from an experiment conducted at 3-hour intervals at 8 western meridional rocket stations are presented. Large variations in the meridional wind contribute substantially to overall turbulence in the tropical stratosphere. The solar semidiurnal component of wind oscillations in the tropics was observed to be much higher than predicted by theory, often exceeding the magnitude of the diurnal amplitude throughout the stratosphere. The observed value of the solar diurnal amplitude in the stratosphere was in line with theoretical prediction. The solar terdiurnal amplitudes for temperature, meridional and zonal winds were non-negligible and must be considered in any harmonic analysis. Phase angle variation with height was rapid for all harmonics; however, there was general agreement between predicted and observed phase angles. Because of large changes in the mean winds in the mesosphere with season, harmonic determinations are difficult. There appear to be large zonal wind changes even within the same season as mentioned previously. Turbulence diffusivity in the upper stratosphere is greater near the equator than in the mid-latitudes

A short-loop algorithm for quantum Monte Carlo simulations

We present an algorithmic framework for a variant of the quantum Monte Carlo operator-loop algorithm, where non-local cluster updates are constructed in a way that makes each individual loop smaller. The algorithm is designed to increase simulation efficiency in cases where conventional loops become very large, do not close altogether, or otherwise behave poorly. We demonstrate and characterize some aspects of the short-loop on a square lattice spin-1/2 XXZ model where, remarkably, a significant increase in simulation efficiency is observed in some parameter regimes. The simplicity of the model provides a prototype for the use of short-loops on more complicated quantum systems.Comment: 9 pages, 9 figures: new FSS discussion adde

Searching for Colorons at the Large Hadron Collider

We investigate the prospects for the discovery of massive color-octet vector bosons at the CERN Large Hadron Collider with $\sqrt{s} = 14$ TeV. A phenomenological Lagrangian is adopted to evaluate the cross section of a pair of colored vector bosons (colorons, $\tilde{\rho}$) decaying into four colored scalar resonances (hyper-pions, $\tilde{\pi}$), which then decay into eight gluons. We include the dominant physics background from the production of $8g,7g1q, 6g2q$, and $5g3q$, and determine the masses of $\tilde{\pi}$ and $\tilde{\rho}$ where discovery is possible. For example, we find that a 5$\sigma$ signal can be established for M_{\tilde{\pi}} \alt 495 GeV (M_{\tilde{\rho}} \alt 1650 GeV). More generally we give the reach of this process for a selection of possible cuts and integrated luminosities.Comment: REVTEX, 20 pages, 16 figure

Generating social network data using partially described networks: an example informing avian influenza control in the British poultry industry

<p>Background: Targeted sampling can capture the characteristics of more vulnerable sectors of a population, but may bias the picture of population level disease risk. When sampling network data, an incomplete description of the population may arise leading to biased estimates of between-host connectivity. Avian influenza (AI) control planning in Great Britain (GB) provides one example where network data for the poultry industry (the Poultry Network Database or PND), targeted large premises and is consequently demographically biased. Exposing the effect of such biases on the geographical distribution of network properties could help target future poultry network data collection exercises. These data will be important for informing the control of potential future disease outbreaks.</p> <p>Results: The PND was used to compute between-farm association frequencies, assuming that farms sharing the same slaughterhouse or catching company, or through integration, are potentially epidemiologically linked. The fitted statistical models were extrapolated to the Great Britain Poultry Register (GBPR); this dataset is more representative of the poultry industry but lacks network information. This comparison showed how systematic biases in the demographic characterisation of a network, resulting from targeted sampling procedures, can bias the derived picture of between-host connectivity within the network.</p> <p>Conclusions: With particular reference to the predictive modeling of AI in GB, we find significantly different connectivity patterns across GB when network estimates incorporate the more demographically representative information provided by the GBPR; this has not been accounted for by previous epidemiological analyses. We recommend ranking geographical regions, based on relative confidence in extrapolated estimates, for prioritising further data collection. Evaluating whether and how the between-farm association frequencies impact on the risk of between-farm transmission will be the focus of future work.</p&gt

Mass Spectra of N=2 Supersymmetric SU(n) Chern-Simons-Higgs Theories

An algebraic method is used to work out the mass spectra and symmetry breaking patterns of general vacuum states in N=2 supersymmetric SU(n) Chern-Simons-Higgs systems with the matter fields being in the adjoint representation. The approach provides with us a natural basis for fields, which will be useful for further studies in the self-dual solutions and quantum corrections. As the vacuum states satisfy the SU(2) algebra, it is not surprising to find that their spectra are closely related to that of angular momentum addition in quantum mechanics. The analysis can be easily generalized to other classical Lie groups.Comment: 17 pages, use revte

AN ANALYSIS OF THE ROLE OF FUTURES PRICES, CASH PRICES AND GOVERNMENT PROGRAMS IN ACREAGE RESPONSE

An integrated investigation of futures price, cash price, and government programs is presented in the context of an econometric model of acreage supply response for U.S. corn and soybeans. The analysis refines the role of different sources of price information in the farmers' acreage decision. It is found that the government corn support price program plays a major role in corn and soybean production decisions. Also, the results indicate that futures prices are not good proxies for expected future cash prices in the presence of government programs. This raises questions about the information efficiency of futures prices when government intervenes in the market place.Crop Production/Industries,

Recipient of the 2010 Alumni Distinguished Leadership Award

Lillian S. Kao, M.D., M.S., is an associate professor in the Department of Surgery and faculty for the Center for Clinical Research and Evidence-Based Medicine at the University of Texas Health Science Center in Houston (UTHSC). She also serves as the Vice-Chief of Surgery at the Lyndon B. Johnson General Hospital in Houston. Dr. Kao’s main research interest is the prevention and treatment of surgical infections. She has several grants for her clinical research, including an NIH career development award. In 2006, Dr. Kao was the recipient of a Robert Wood Johnson Physician Faculty Scholar to study interventions to improve the prevention of surgical site infections, which are a significant problem resulting in worsened patient outcome and increased health care expenditures. In particular, she is interested in maximizing compliance with evidence-based guidelines for the prevention of these infections within a county hospital system with limited resources. Her other interest is in educating surgeons about clinical research. She has co-founded a Center for Surgical Trials and Evidence-based Practice (C-STEP) at UTHSC, co-directed the Fundamentals of Surgical Research Course (a yearly national course which is put on by the Association for Academic Surgery or AAS, a society for academic surgeons of which she is the Secretary on the Executive Council), participated as guest faculty at international research courses (i.e. Developing a Career in Academic Surgery in Australia), and recently was the AAS Visiting Professor to the Taiwan Surgical Association where she lectured on evidence-based surgery. Dr. Kao received her medical degree from the University of Michigan in Ann Arbor, completed surgical residency and a fellowship in gastrointestinal surgery at the University of Washington in Seattle, and completed a surgical critical care fellowship and obtained a Masters Degree in Clinical Research at UTHSC