4,171 research outputs found

    Asymmetric Prices: Implications on Trader’s Market Power in Philippine Rice

    Get PDF
    Contrary to the commonly held notion that the market power exercised by a handful of unscrupulous traders in the local market has resulted unnecessary hike in prices, this paper presents evidence against this allegation. Findings show that market shocks originate at the farm level that are transmitted as price changes at the wholesale market before it is reflected at the retail market. In addition, symmetry test cannot confirm the presence of market power among Filipino traders. Nevertheless, estimation of price symmetry model does not lend credence to the claim that government’s absence in the market can lead to chaos.price level

    Asymmetric Prices: Implications on Trader’s Market Power in Philippine Rice

    Get PDF
    Contrary to the commonly held notion that the market power exercised by a handful of unscrupulous traders in the local market has resulted unnecessary hike in prices, this paper presents evidence against this allegation. Findings show that market shocks originate at the farm level that are transmitted as price changes at the wholesale market before it is reflected at the retail market. In addition, symmetry test cannot confirm the presence of market power among Filipino traders. Nevertheless, estimation of price symmetry model does not lend credence to the claim that government’s absence in the market can lead to chaos.price level

    Recreation, Tourism, and Rural Well-Being

    Get PDF
    The promotion of recreation and tourism has been both praised and criticized as a rural development strategy. This study uses regression analysis to assess the effect of recreation and tourism development on socioeconomic conditions in rural recreation counties. The findings imply that recreation and tourism development contributes to rural well-being, increasing local employment, wage levels, and income, reducing poverty, and improving education and health. But recreation and tourism development is not without drawbacks, including higher housing costs. Local effects also vary significantly, depending on the type of recreation area.recreation, tourism, recreation counties, rural development, economic indicators, social indicators, rural development policy, Community/Rural/Urban Development, Resource /Energy Economics and Policy,

    Engineering tyrosine-based electron flow pathways in proteins: The case of aplysia myoglobin

    Get PDF
    Tyrosine residues can act as redox cofactors that provide an electron transfer ("hole-hopping") route that enhances the rate of ferryl heme iron reduction by externally added reductants, for example, ascorbate. Aplysia fasciata myoglobin, having no naturally occurring tyrosines but 15 phenylalanines that can be selectively mutated to tyrosine residues, provides an ideal protein with which to study such through-protein electron transfer pathways and ways to manipulate them. Two surface exposed phenylalanines that are close to the heme have been mutated to tyrosines (F42Y, F98Y). In both of these, the rate of ferryl heme reduction increased by up to 3 orders of magnitude. This result cannot be explained in terms of distance or redox potential change between donor and acceptor but indicates that tyrosines, by virtue of their ability to form radicals, act as redox cofactors in a new pathway. The mechanism is discussed in terms of the Marcus theory and the specific protonation/deprotonation states of the oxoferryl iron and tyrosine. Tyrosine radicals have been observed and quantified by EPR spectroscopy in both mutants, consistent with the proposed mechanism. The location of each radical is unambiguous and allows us to validate theoretical methods that assign radical location on the basis of EPR hyperfine structure. Mutation to tyrosine decreases the lipid peroxidase activity of this myoglobin in the presence of low concentrations of reductant, and the possibility of decreasing the intrinsic toxicity of hemoglobin by introduction of these pathways is discussed. © 2012 American Chemical Society

    Supersonic jet mixing enhancement by delta-tabs

    Get PDF
    The results of a continuing investigation of the effect of vortex generators, in the form of small tabs at the nozzle exit, on the evolution of a jet are reported. Primarily, tabs of triangular shape are considered, and the effect is studied up to an equivalent jet Mach number of 1.8. By changing the orientation of the tab with respect to the nozzle exit plane, streamwise vortex pairs of opposite sign were generated. This resulted in either an outward election of jet core fluid into the ambient or an inward indentation of the mixing layer into the core of the jet. A triangular shaped tab with its apex leaning downstream, referred to as a delta tab, was found to be the most effective in influencing the jet evolution. Two delta tabs, spaced 180 degrees apart, completely bifurcated the jet. Four delta tabs increased jet mixing substantially, more than by various other methods tried previously; the mass flux at fourteen jet diameters downstream from the nozzle increased by about 50 percent over that for the no tab case. The tabs were found to be effective in jets with laminar or turbulent boundary layers as well as in jets with low or high core turbulence intensities

    Effect of tabs on the evolution of an axisymmetric jet

    Get PDF
    The effect of vortex generators, in the form of small tabs at the nozzle exit, on the evolution of an axisymmetric jet was investigated experimentally over a jet Mach number range of 0.34 to 1.81. The effects of one, two, and four tabs were studied in comparison with the corresponding case without a tab. Each tab introduced an indentation in the shear layer, apparently through the action of streamwise vortices which appeared to be of the trailing vortex type originating from the tips of the tab rather that of the necklace vortex type originating from the base of the tab. The resultant effect of two tabs, placed at diametrically opposite locations, was to essentially bifurcate the jet. The influence of the tabs was essentially the same at subsonic and supersonic conditions indicating that compressibility has little to do with the effect

    Inter-Piece Sampling and Convolution: Portfolio of 5.1 Acousmatic and Electronica Compositions, Interactive Diagrams and Text

    Full text link
    This practice-based PhD – ‘Inter-piece Sampling and Convolution’ – evolved against the background of composers such as Amon Tobin and Monty Adkins, who use techniques and workflows common to both acousmatic and electronica music. The pieces in this thesis are linked through a sustained commitment to working across these two musical contexts and through their relationships to source materials and pulses. Sound materials have been sampled from within the pieces themselves, and materials from older pieces have been convolved with newer sounds, furthering the connections between pieces. The continual feeding-forward of source material promoted the synchronous development of the conceptual tool: Input, Sculpt, Output, which brought about the evolution of intricate diagrams. All of the pieces are for fixed media, and nine of the ten are in 5.1-format surround sound. The complex web of interrelationships created by the process of sampling and convolving material from previous pieces demanded an innovative means of representation. This representation took on a diagrammatic form in order to facilitate the analysis of a sound’s continuous (re)appropriation, explicated within supporting text. The diagrams indicate the extensive use of sampling and convolution to connect pieces, and include embedded hyperlinks to audio at various stages. As a result, textual analysis of techniques and their implications takes place across multiple pieces, and results in a wider scope for individual commentaries. The hyperlinked nature of the diagrams provides a foundation for further research, and a number of conclusions are posited about the use of sampling and convolution across multiple pieces

    High dose interval vitamin D supplementation in pediatric patients with inflammatory bowel disease receiving Remicade

    Get PDF
    BACKGROUND: Patients suffering from inflammatory bowel disease (IBD) are at increased risk of vitamin D deficiency. Daily or weekly vitamin D supplementation has not proven to be effective in improving vitamin D status, and it is thought that this failure has been primarily due to a lack of compliance. Circulating vitamin D is crucial to bone growth and development in children and adolescents. However, more recent data has demonstrated that vitamin D also plays a significant role in the maintenance and regulation of the immune system. OBJECTIVES: The primary aim of this study is to investigate the safety and efficacy of administering high dose oral vitamin D therapy in pediatric patients with IBD. We chose to study patients receiving Remicade, an immunosuppressive monoclonal antibody therapy administered intravenously, as the need for scheduled hospital-based infusions provides a unique opportunity to ensure compliance in our study population. METHODS: We identified consecutive pediatric patients with IBD with a recent 25-hydroxyvitamin D (25OHD) level < 30ng/mL, maintained on Remicade, and with no history of kidney or liver disease for inclusion in the study from November 2017 and November 2018. Enrolled patients received one-year of open-label therapy. Vitamin D treatment doses were assigned by Remicade interval and patients received either 50,000 international units (IU) (every 4-5 weeks) or 100,000 IU (every 6-8 weeks) vitamin D3 orally at the time of their Remicade infusions. In addition to vitamin D levels, spot urine calcium to creatinine ratios, serum calcium, phosphorus, and blood urea nitrogen (BUN) levels, quality of life metrics, and surveys pertaining to dietary vitamin D intake and ultraviolet B (UVB) radiation exposure were collected throughout the study period. RESULTS: Baseline vitamin D status in enrolled patients did not differ by gender, dosing group, diet, or diagnosis (Crohn disease or ulcerative colitis). Subjects reached steady-state serum 25OHD levels after three doses administered over a span of 4 to 8 months, our data demonstrated an increase in average 25OH vitamin D levels from 21.17 ng/mL to 28.19 ng/mL in the 50,000 IU and 23.00 ng/mL to 33.18 ng/mL in the 100,000 IU dose groups, respectively. The improvement in vitamin D status did not correlate with changes in quality of life or disease activity. The response to vitamin D therapy was independent of diet, sun exposure, race, gender, diagnosis, or season of enrollment. There were no adverse events, including changes in urine calcium to creatinine excretion or serum BUN and creatinine values. Several patients manifest a small decrease in serum phosphorus during the initial phase of the study. However, these changes were transient and no subjects exhibited clinical signs or symptoms of hypophosphatemia. CONCLUSION: High dose, interval vitamin D supplementation achieved steady-state 25OHD levels of 30 ng/mL or greater, with no signs of toxicity in patients enrolled in this pilot study. These data suggest that high-dose interval therapy may be a feasible treatment option that bypasses limitations related to difficulties with patient compliance. Further studies are necessary to determine optimal dosage regimens and to assess endpoints related to immune function and improvements to gastrointestinal health

    Wheat policy reform in Egypt: adjustment of local markets and options for future reforms

    Get PDF
    Many developing countries are in transition from a state-dominated to a more market-oriented economy. Because agriculture is of primary importance in most developing countries,the state is usually heavily involved in both input and output markets and in controlling prices and trade. However, concerns that market liberalization will result in higher consumer food prices and hurt the poor means that many countries, such as Egypt, have, at best, undertaken only partial agricultural sector reforms. It has been argued that such concerns are unwarranted and that further market liberalization is not only needed, but achievable without increasing impoverishment. IFPRI Research Report 115 sheds light on these critical issues through an analysis of wheat policy reform in Egypt.Consumers Egypt., Wheat trade Government policy Egypt., Food supply Government policy Egypt., Agricultural policies, Markets Prices., Developing countries. ,

    Review of operational aspects of initial experiments utilizing the U.S. MLS

    Get PDF
    An exercise to support the Federal Aviation Administration in demonstrating the U.S. candidate for an international microwave landing system (MLS) was conducted by NASA. During this demonstration the MLS was utilized to provide the TCV Boeing 737 research airplane with guidance for automatic control during transition from conventional RNAV to MLS RNAV in curved, descending flight; flare; touchdown; and roll-out. Flight profiles, system configuration, displays, and operating procedures used in the demonstration are described, and preliminary results of flight data analysis are discussed. Recent experiences with manually controlled flight in the NAFEC MLS environment are also discussed. The demonstration shows that in automatic three-dimensional flight, the volumetric signal coverage of the MLS can be exploited to enable a commercial carrier class airplane to perform complex curved, descending paths with precision turns into short final approaches terminating in landing and roll-out, even when subjected to strong and gusty tail and cross wind components and severe wind shear
    • 

    corecore