Business orientation and the food security status of small scale producers in the Venda region, South Africa

Questions addressed in this paper are: How to determine the food status of rural households; and does an agribusiness orientation enhance the food security status of farm families. A study was conducted on two groups of small scale black farmers in the Venda region: one group, agribusiness directed and generally more progressive towards technology, produces mangos and other subtropical fruits (cash crop farmers); the other group concentrates on locally consumed and sold vegetables (food crop farmers). Their food status was quantitatively determined by means of household energy, protein and fat balances and food security determinants were identified. More than 80% of the households had a negative balance for energy, protein or fat. Business orientation and farming type in this particular case study does not influence the energy, protein and fat coverage significantly. The marginal nature of farming by these small holders could explain this finding. Significant predictors of food security status were rather factors such as the household size and the availability of outside sources of income and cash to spend on food.Agribusiness, Food Security and Poverty,

Assessment of Knowledge Management’s Growth in South Africa

This article revisits a debate surrounding Knowledge Management (KM) to report on an empirical study conducted in 86 South African based organizations, specifically regarding growth in KM maturity over a five year period. The findings indicate that KM is fairly well institutionalized in South African industry, with most organizations indicating that significant growth occurred in KM over the past five years. Analysis of the growth in KM maturity, as it relates to different organizational sizes, reveals that there are statistical differences between the score reported by Small, Medium, Large and Extra-Large organizations. Similarly, scores reported by Senior, Middle and Operational personnel differ primarily between the scores decided upon by Operational personnel and Senior managers. Viewed holistically, findings suggest that there could be a “break-even point” between resources available and KM growth with Extra-Large organizations given their advantage in KM growth. Findings also indicated that growth in KM differs between industry groupings, with Construction, Building Materials and Mining companies achieving high growth (+/- 70%), Consumer Goods and Utilities (+/- 60%), Banks and Insurance, Automotive and Transport, Government and ICT companies, moderate growth (+/- 50%), and Educational institutions, low growth (+/- 40%)

Spectrum of One-Dimensional Anharmonic Oscillators

We use a power-series expansion to calculate the eigenvalues of anharmonic oscillators bounded by two infinite walls. We show that for large finite values of the separation of the walls, the calculated eigenvalues are of the same high accuracy as the values recently obtained for the unbounded case by the inner-product quantization method. We also apply our method to the Morse potential. The eigenvalues obtained in this case are in excellent agreement with the exact values for the unbounded Morse potential.Comment: 11 pages, 5 figures, 4 tables; there are changes to match the version published in Can. J. Phy

Property Studies of Alaskan Silts in the Matanuska Valley, Big Delta, and Fairbanks Areas

The study of four Alaskan areas was begun in the summer of 1954 under a program sponsored by the Office of Naval Research. The Iowa State College Engineering Experiment Station directed the study in collaboration with the Department of Geology, Iowa State College. The program was initiated to: 1. Determine the distribution of engineering soil materials m four Alaska areas. 2. Determine the engineering properties and trafficability characteristic; of these materials. 3. Determine the feasibility and best methods of stabilizing these materials for use as road and airfield building material. 4. Further the studies of geology of Alaska. 5. Attempt a correlation of the engineering and geologic properties of the Alaskan materials with similar materials in the Midwest United States

Disorder and thermally driven vortex-lattice melting in La{2-x}Sr{x}CuO{4} crystals

Magnetization measurements in La{2-x}Sr{x}CuO{4} crystals indicate vortex order-disorder transition manifested by a sharp kink in the second magnetization peak. The transition field exhibits unique temperature dependence, namely a strong decrease with temperature in the entire measured range. This behavior rules out the conventional interpretation of a disorder-driven transition into an entangled vortex solid phase. It is shown that the transition in La{2-x}Sr{x}CuO{4} is driven by both thermally- and disorder-induced fluctuations, resulting in a pinned liquid state. We conclude that vortex solid-liquid, solid-solid and solid to pinned-liquid transitions are different manifestations of the same thermodynamic order-disorder transition, distinguished by the relative contributions of thermal and disorder-induced fluctuations.Comment: To be published in phys. Rev. B Rapid Com

Flow characterisation for a validation study in high-speed aerodynamics

Validation studies are becoming increasingly relevant when investigating complex flow problems in high-speed aerodynamics. These investigations require calibration of numerical models with accurate data from the physical wind tunnel being studied. This paper presents the characterisation process for a joint experimental-computational study to investigate the streamwise corners of a Mach 2.5 channel flow. As well as checks of flow quality typically performed for phenomenological investigations, additional quantitative tests are conducted. The extra care to obtain high quality data and eliminate any systematic errors reveal useful information about the wind tunnel flow. Further important physical insights are gained from designing and conducting wind tunnel tests in conjunction with numerical simulations. Crucially, the close experimental-computational collaboration enabled the identification of secondary flows in the sidewall boundary-layers; these strongly influence the flow in the corner regions, the target of the validation study

Distribution of graph-distances in Boltzmann ensembles of RNA secondary structures

Large RNA molecules often carry multiple functional domains whose spatial arrangement is an important determinant of their function. Pre-mRNA splicing, furthermore, relies on the spatial proximity of the splice junctions that can be separated by very long introns. Similar effects appear in the processing of RNA virus genomes. Albeit a crude measure, the distribution of spatial distances in thermodynamic equilibrium therefore provides useful information on the overall shape of the molecule can provide insights into the interplay of its functional domains. Spatial distance can be approximated by the graph-distance in RNA secondary structure. We show here that the equilibrium distribution of graph-distances between arbitrary nucleotides can be computed in polynomial time by means of dynamic programming. A naive implementation would yield recursions with a very high time complexity of O(n^11). Although we were able to reduce this to O(n^6) for many practical applications a further reduction seems difficult. We conclude, therefore, that sampling approaches, which are much easier to implement, are also theoretically favorable for most real-life applications, in particular since these primarily concern long-range interactions in very large RNA molecules.Comment: Peer-reviewed and presented as part of the 13th Workshop on Algorithms in Bioinformatics (WABI2013

Unified order-disorder vortex phase transition in high-Tc superconductors

The diversity of vortex melting and solid-solid transition lines measured in different high-T$_{c}$ superconductors is explained, postulating a unified order-disorder phase transition driven by both thermally- and disorder-induced fluctuations. The temperature dependence of the transition line and the nature of the disordered phase (solid, liquid, or pinned liquid) are determined by the relative contributions of these fluctuations and by the pinning mechanism. By varying the pinning mechanism and the pinning strength one obtains a spectrum of monotonic and non-monotonic transition lines similar to those measured in Bi$_{2}$Sr$_{2}$CaCu$_{2}$O$$, YBa$_{2}$Cu$_{3}$O$_{7-\delta}$, Nd$_{1.85}$Ce$_{0.15}$CuO$$, Bi$_{1.6}$Pb$_{0.4}$Sr$_{2}$CaCu$_{2}$O$_{8+\delta}$ and (La$_{0.937}$Sr$_{0.063}$)$_{2}$CuO$_{4}$Comment: To be published in Phys. Rev. B Rapid Com

First-Principles Studies of Hydrogenated Si(111)--7×\times7

The relaxed geometries and electronic properties of the hydrogenated phases of the Si(111)-7$\times$7 surface are studied using first-principles molecular dynamics. A monohydride phase, with one H per dangling bond adsorbed on the bare surface is found to be energetically favorable. Another phase where 43 hydrogens saturate the dangling bonds created by the removal of the adatoms from the clean surface is found to be nearly equivalent energetically. Experimental STM and differential reflectance characteristics of the hydrogenated surfaces agree well with the calculated features.Comment: REVTEX manuscript with 3 postscript figures, all included in uu file. Also available at http://www.phy.ohiou.edu/~ulloa/ulloa.htm