29,598 research outputs found
Risk Factors for Non-communicable Diseases Among Adults of 25-65 Years at Kakamega County General Hospital, Kenya
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. Ï2 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 TriglycerideÏ2 (12, N=60)= 25.752 P=0.012, BMI and LDLÏ2(8,N=60)=19.312 p=0.013, BMI and Total Cholesterol Ï2(8, N=60)=18.694 p=0.017, MUAC and HDL Ï2(4, N=60) =14.446 p=0.006, WHR and Total Cholesterol Ï2(2, N=60)=17.985 p=0.000, WHR and LDL Ï2(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
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
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
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Domestic market potential for tree products from farms and rural communities: Experience from Cameroon
This publication summarizes the results of research carried out by NRI in Cameroon during 1995-96 on the domestic market potential for tree products from farms and rural communities. The study arose from concern that agroforestry projects, which generally aim to reduce the pressure on natural forests by planting trees on farmland, were inadequately addressing the associated marketing needs. As a consequence, many of the projects were failing. The research reported here sought to characterize the markets for non-timber tree products (NTTPs) and highlight constraints to the development of markets for traditional and emerging NTTPs. The research in Cameroon was paralleled by a study in the Brazilian Amazon carried out by IFPRI; ODA provided funding for both studies. The work began with an inventory of products and subsequent identification of marketing chains. Four products were selected as case studies and were used to explore issues relating to valued added, domestication and the role of NTTPs as sources of income. The marketing of the four products was well-established and appeared to be relatively competitive, in spite of some concerns over lack of information at farmer level. There was growing demand for the products, apparently matched by increasing supply. The wholesalers, who source the products in the forest fringe communities and sell them on to retailers, were the most dynamic links in the marketing chains. The impetus to domesticate NTTPs seemed always to be farmer-driven, and occurred when a product important for subsistence and income needs was not readily available from the forest. However, the role of NTTPs within the farming system is important; they must fit into a complex strategy which includes seasonal smoothing of income, production and labour needs. Also, tree-planting is a long-term investment which is unlikely to be undertaken if land tenure is insecure. In conclusion, areas are highlighted for future research. These include: technical aspects of cultivation, processing and storage; identification of products which will be in greater demand as a result of urbanization; the role of NTTPs in the livelihood strategies of particularly vulnerable groups (including the landless) in the forest fringe communities
Finding Approximate POMDP solutions Through Belief Compression
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
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
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
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
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
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