11,372 research outputs found
Prospects for Uganda's Dairy Industry
The East African country of Uganda might not be thought of as the location of a viable, growing dairy industry. However, Uganda recorded a threefold increase in milk production from 1991 to 2004. While Uganda's dairy industry faces important challenges, the industry possesses advantages that can lead to further increases in milk production if additional, profitable markets can be found for Uganda's milk and dairy products. A major advantage possessed by Uganda's dairy industry is a favorable climate for milk production. Uganda's farmers also have demonstrated a willingness to accept new technologies that can increase milk production. The biggest challenges facing the industry are those associated with poor milk quality and pronounced seasonality of milk production.Uganda Dairy Industry, Uganda's Political and Economic Environment, Pasture-Based Dairy Industry, Poor Milk Quality, Agribusiness, Crop Production/Industries, Farm Management, Food Consumption/Nutrition/Food Safety, Industrial Organization, International Development, International Relations/Trade, Land Economics/Use, Political Economy, Public Economics,
Maximum Mass-Radius Ratio for Compact General Relativistic Objects in Schwarzschild- de Sitter Geometry
Upper limits for the mass-radius ratio are derived for arbitrary general
relativistic matter distributions in the presence of a cosmological constant.
General restrictions for the red shift and total energy (including the
gravitational contribution) for compact objects in the Schwarzschild-de Sitter
geometry are also obtained in terms of the cosmological constant and of the
mean density of the star.Comment: 8 pages, no figure
Sequencing the Genome of the North American Bison
American bison (Bison bison) is a well-known iconic species with a history and legacy intertwined with the Plains of North America. Unfortunately, the American colonization of North America in the late 1800’s resulted in the almost complete destruction of the American bison and subsequent population bottleneck. Bison were also faced with forced hybridization of domestic cattle genetics (Bos taurus), through failed experiments of some ranchers to produce a hardier beef animal for the greatplains. The hybridization of domestic cattle into bison presents challenges in the management and conservation of American bison today, primarily because it is difficult to differentiate between hybrid cattle-bison and purebred bison within a population.
Whole genome sequencing provides the next step in advancing bison management and conservation. A 2.82-Gb de novo reference assembly of the American bison genome was produced using approximately 75X coverage, utilizing both mate pair and pair-end sequencing. Illumina, Inc. and 454 Life Sciences Technologies raw sequence reads were mapped to both nuclear and mitochondrial sequences of the domestic cattle reference UMD3.1 (Ensembl GCA_000003055.3), in order to detect genetic variants, including single nucleotide variants (SNVs) and insertion and deletions (INDELs). An additional 14 re-sequenced bison genomes were also aligned to the UMD3.1 domestic cattle reference sequence to identify genomic variants. These variants were determined and annotated to examine their effect on gene structure and function in bison.
With the completed de novo plains bison reference genome sequence a comparison of historic and modern bison sequences identified genomic variants and were compared across bison populations. Historic bison samples that predate cattle and bison introgression were sequenced and conserved genomic regions between historic and current bison were identified. Identified variants between modern and historic bison provided an outline of the genetic architecture of bison that existed before the population bottleneck. This genomic analysis of North American bison provides insight into the genetic history, taxonomy, and inheritance of important genetic traits in bison that have allowed them to not only survive but thrive in their recovery from this population bottle neck that occurred 130 years ago
All women with multiple sclerosis should start hormone replacement therapy at menopause unless contraindicated: Commentary.
Correlation potentials for molecular bond dissociation within the self-consistent random phase approximation
Self-consistent correlation potentials for H and LiH for various
inter-atomic separations are obtained within the random phase approximation
(RPA) of density functional theory. The RPA correlation potential shows a peak
at the bond midpoint, which is an exact feature of the true correlation
potential, but lacks another exact feature: the step important to preserve
integer charge on the atomic fragments in the dissociation limit. An analysis
of the RPA energy functional in terms of fractional charge is given which
confirms these observations. We find that the RPA misses the derivative
discontinuity at odd integer particle numbers but explicitly eliminates the
fractional spin error in the exact-exchange functional. The latter finding
explains the accurate total energy in the dissociation limit.Comment: 9 pages, 10 figure
Self-Templated Nucleation in Peptide and Protein aggregation
Peptides and proteins exhibit a common tendency to assemble into highly
ordered fibrillar aggregates, whose formation proceeds in a
nucleation-dependent manner that is often preceded by the formation of
disordered oligomeric assemblies. This process has received much attention
because disordered oligomeric aggregates have been associated with
neurodegenerative disorders such as Alzheimer's and Parkinson's diseases. Here
we describe a self-templated nucleation mechanism that determines the
transition between the initial condensation of polypeptide chains into
disordered assemblies and their reordering into fibrillar structures. The
results that we present show that at the molecular level this transition is due
to the ability of polypeptide chains to reorder within oligomers into fibrillar
assemblies whose surfaces act as templates that stabilise the disordered
assemblies.Comment: 4 pages, 3 figure
Transmission dynamics and prospects for the elimination of canine rabies
Rabies has been eliminated from domestic dog populations in Western Europe and North America, but continues to kill many thousands of people throughout Africa and Asia every year. A quantitative understanding of transmission dynamics in domestic dog populations provides critical information to assess whether global elimination of canine rabies is possible. We report extensive observations of individual rabid animals in Tanzania and generate a uniquely detailed analysis of transmission biology, which explains important epidemiological features, including the level of variation in epidemic trajectories. We found that the basic reproductive number for rabies, R<sub>0</sub>, is very low in our study area in rural Africa (∼1.2) and throughout its historic global range (<2). This finding provides strong support for the feasibility of controlling endemic canine rabies by vaccination, even near wildlife areas with large wild carnivore populations. However, we show that rapid turnover of domestic dog populations has been a major obstacle to successful control in developing countries, thus regular pulse vaccinations will be required to maintain population-level immunity between campaigns. Nonetheless our analyses suggest that with sustained, international commitment, global elimination of rabies from domestic dog populations, the most dangerous vector to humans, is a realistic goal
A longitudinal investigation of information processing and cognitive organization in clinical depression: stability of schematic interconnectedness.
This study longitudinally investigated information processing and cognitive organization in clinical depression. The main hypothesis was that individuals whose depression had remitted would show a significant cognitive shift on information processing (e.g., deactivation of negative processing) but not on cognitive organizational tasks, Forty-five individuals with clinical depression completed 2 information processing and 2 cognitive organizational tasks at initial assessment. At 6-month follow-up, the sample (23 remitted, 22 stable depressed) was readministered the tasks. As expected, information processing shifted significantly in individuals who had improved symptomatically, whereas negative cognitive organizational indices remained stable. The implications of these results are discussed as they pertain to the cognitive vulnerability, maintenance, treatment, and recurrence of depression. Directions for future research are suggested
Evaluation of the soil moisture prediction accuracy of a space radar using simulation techniques
Image simulation techniques were employed to generate synthetic aperture radar images of a 17.7 km x 19.3 km test site located east of Lawrence, Kansas. The simulations were performed for a space SAR at an orbital altitude of 600 km, with the following sensor parameters: frequency = 4.75 GHz, polarization = HH, and angle of incidence range = 7 deg to 22 deg from nadir. Three sets of images were produced corresponding to three different spatial resolutions; 20 m x 20 m with 12 looks, 100 m x 100 m with 23 looks, and 1 km x 1 km with 1000 looks. Each set consisted of images for four different soil moisture distributions across the test site. Results indicate that, for the agricultural portion of the test site, the soil moisture in about 90% of the pixels can be predicted with an accuracy of = + or - 20% of field capacity. Among the three spatial resolutions, the 1 km x 1 km resolution gave the best results for most cases, however, for very dry soil conditions, the 100 m x 100 m resolution was slightly superior
The Contradiction in China's Gradualist Banking Reforms
China’s state-owned banks have historically funded money-losing state enterprises as a way of maintaining employment and social stability, but this practice has led to bank insolvency and bailouts. We survey the Chinese banking industry, focusing on the largest banks, which are being reformed to increase their competitiveness following China’s 2001 commitment to open its domestic banking market. We assemble macroeconomic, microeconomic, and anecdotal evidence suggesting that government influence, although less explicit than in the past, continues despite the reforms. Indeed, the reforms thus far do not resolve the tensions between government objectives and the obligation of commercial banks to base their credit decisions on an objective appraisal of ability to repay. We conclude that, when growth slows, this contradiction will become fully apparent, and the government will resolve it by again bailing out the banks. We describe alternative bank reform proposals that would help reconcile the banks’ conflicting objectives.macroeconomics, China, China banks, China reform
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