29,356 research outputs found

    Risk Factors for Non-communicable Diseases Among Adults of 25-65 Years at Kakamega County General Hospital, Kenya

    Get PDF
    In Kenya the growing number of premature deaths with half of all hospital admissions and 33% of all deaths are associated with Non-communicable diseases. The study determined the physical measurements and lipid parameters of adults 25-65 years at Kakamega County General Hospital. Data was collected using the WHO STEPs Instrument: Physical measurements assessed were Mid Upper Arm Circumference, Waist Hip measurements, Body mass Index and blood pressure. The study significance level was 0.05. Data was analyzed using SPSS version 20. Descriptive statistics was used. χ2 test of independence was used to find out the relationship between anthropometric measurements and lipid parameters. Data was presented in form of tables, figures and texts. There was a significant relationship between BMI and Triglycerideχ2 (12, N=60)= 25.752 P=0.012, BMI and LDLχ2(8,N=60)=19.312 p=0.013, BMI and Total Cholesterol χ2(8, N=60)=18.694 p=0.017, MUAC and HDL χ2(4, N=60) =14.446 p=0.006, WHR and Total Cholesterol χ2(2, N=60)=17.985 p=0.000, WHR and LDL χ2(2, N=60)=15.246p=0.000. The study advocated for policies to reduce the incidences of risk factors for NCDs which will assist in achievement of Sustainable Development Goals. Kenyan population are in need of screening for risks associated with NCDs

    Demographic growth and the distribution of language sizes

    Full text link
    It is argued that the present log-normal distribution of language sizes is, to a large extent, a consequence of demographic dynamics within the population of speakers of each language. A two-parameter stochastic multiplicative process is proposed as a model for the population dynamics of individual languages, and applied over a period spanning the last ten centuries. The model disregards language birth and death. A straightforward fitting of the two parameters, which statistically characterize the population growth rate, predicts a distribution of language sizes in excellent agreement with empirical data. Numerical simulations, and the study of the size distribution within language families, validate the assumptions at the basis of the model.Comment: To appear in Int. J. Mod. Phys. C (2008

    Simulation evaluation of a low-altitude helicopter flight guidance system adapted for a helmet-mounted display

    Get PDF
    A computer aiding concept for low-altitude helicopter flight was developed and evaluated in a real-time piloted simulation. The concept included an optimal control trajectory-generation algorithm based upon dynamic programming and a helmet-mounted display (HMD) presentation of a pathway-in-the-sky, a phantom aircraft, and flight-path vector/predictor guidance symbology. The trajectory-generation algorithm uses knowledge of the global mission requirements, a digital terrain map, aircraft performance capabilities, and advanced navigation information to determine a trajectory between mission way points that seeks valleys to minimize threat exposure. The pilot evaluation was conducted at NASA ARC moving base Vertical Motion Simulator (VMS) by pilots representing NASA, the U.S. Army, the Air Force, and the helicopter industry. The pilots manually tracked the trajectory generated by the algorithm utilizing the HMD symbology. The pilots were able to satisfactorily perform the tracking tasks while maintaining a high degree of awareness of the outside world

    Finding Approximate POMDP solutions Through Belief Compression

    Full text link
    Standard value function approaches to finding policies for Partially Observable Markov Decision Processes (POMDPs) are generally considered to be intractable for large models. The intractability of these algorithms is to a large extent a consequence of computing an exact, optimal policy over the entire belief space. However, in real-world POMDP problems, computing the optimal policy for the full belief space is often unnecessary for good control even for problems with complicated policy classes. The beliefs experienced by the controller often lie near a structured, low-dimensional subspace embedded in the high-dimensional belief space. Finding a good approximation to the optimal value function for only this subspace can be much easier than computing the full value function. We introduce a new method for solving large-scale POMDPs by reducing the dimensionality of the belief space. We use Exponential family Principal Components Analysis (Collins, Dasgupta and Schapire, 2002) to represent sparse, high-dimensional belief spaces using small sets of learned features of the belief state. We then plan only in terms of the low-dimensional belief features. By planning in this low-dimensional space, we can find policies for POMDP models that are orders of magnitude larger than models that can be handled by conventional techniques. We demonstrate the use of this algorithm on a synthetic problem and on mobile robot navigation tasks

    A Tunable Anomalous Hall Effect in a Non-Ferromagnetic System

    Full text link
    We measure the low-field Hall resistivity of a magnetically-doped two-dimensional electron gas as a function of temperature and electrically-gated carrier density. Comparing these results with the carrier density extracted from Shubnikov-de Haas oscillations reveals an excess Hall resistivity that increases with decreasing temperature. This excess Hall resistivity qualitatively tracks the paramagnetic polarization of the sample, in analogy to the ferromagnetic anomalous Hall effect. The data are consistent with skew-scattering of carriers by disorder near the crossover to localization

    Large Scale Structure Forecast Constraints on Particle Production During Inflation

    Full text link
    Bursts of particle production during inflation provide a well-motivated mechanism for creating bump like features in the primordial power spectrum. Current data constrains these features to be less than about 5% the size of the featureless primordial power spectrum at wavenumbers of about 0.1 h Mpc^{-1}. We forecast that the Planck cosmic microwave background experiment will be able to strengthen this constraint to the 0.5% level. We also predict that adding data from a square kilometer array (SKA) galaxy redshift survey would improve the constraint to about the 0.1% level. For features at larger wave-numbers, Planck will be limited by Silk damping and foregrounds. While, SKA will be limited by non-linear effects. We forecast for a Cosmic Inflation Probe (CIP) galaxy redshift survey, similar constraints can be achieved up to about a wavenumber of 1 h Mpc^{-1}.Comment: 10 pages. Matches PRD accepted versio

    Universal Scaling in Non-equilibrium Transport Through a Single-Channel Kondo Dot

    Full text link
    Scaling laws and universality play an important role in our understanding of critical phenomena and the Kondo effect. Here we present measurements of non-equilibrium transport through a single-channel Kondo quantum dot at low temperature and bias. We find that the low-energy Kondo conductance is consistent with universality between temperature and bias and characterized by a quadratic scaling exponent, as expected for the spin-1/2 Kondo effect. The non-equilibrium Kondo transport measurements are well-described by a universal scaling function with two scaling parameters.Comment: v2: improved introduction and theory-experiment comparsio

    Bose-Einstein transition temperature in a dilute repulsive gas

    Get PDF
    We discuss certain specific features of the calculation of the critical temperature of a dilute repulsive Bose gas. Interactions modify the critical temperature in two different ways. First, for gases in traps, temperature shifts are introduced by a change of the density profile, arising itself from a modification of the equation of state of the gas (reduced compressibility); these shifts can be calculated simply within mean field theory. Second, even in the absence of a trapping potential (homogeneous gas in a box), temperature shifts are introduced by the interactions; they arise from the correlations introduced in the gas, and thus lie inherently beyond mean field theory - in fact, their evaluation requires more elaborate, non-perturbative, calculations. One illustration of this non-perturbative character is provided by the solution of self-consistent equations, which relate together non-linearly the various energy shifts of the single particle levels k. These equations predict that repulsive interactions shift the critical temperature (at constant density) by an amount which is positive, and simply proportional to the scattering length a; nevertheless, the numerical coefficient is difficult to compute. Physically, the increase of the temperature can be interpreted in terms of the reduced density fluctuations introduced by the repulsive interactions, which facilitate the propagation of large exchange cycles across the sample.Comment: two minor corrections, two refs adde
    • 

    corecore