4,511 research outputs found
EUROPEAN UNION COTTON DEMAND: AN APPLICATION OF DEMAND SYSTEMS AND PANEL DATA
A demand system approach incorporating demographic variables is used to estimate the European Union cotton demand parameters. The European Union is the largest cotton importer of the world. Accurate estimation of European demand parameters is critical to evaluate world cotton trends and to realistically simulate future market scenarios. Unlike previous studies, this paper reports a research in which demands of the 15 European Union members are not aggregated. Moreover, unlike available estimations, the study does not use mill consumption data but cotton equivalent consumption at home.International Relations/Trade,
Estimation of a Censored Demand System in Stratified Sampling: An Analysis of Mexican Meat Demand at the Table Cut Level.
Evidence of meat trade in the form of table cuts suggests that consumer preferences and tastes vary across meat cuts. Unlike previous studies, this paper estimates demand elasticities at the table cut level from a Mexican survey of household incomes and expenditures, which is a stratified sample. The study uses the two-step estimation of a censored demand system proposed by Shonkwiler and Yen (1999) but incorporates stratification variables into the estimation procedure. Parameter estimates are reported and its standard errors are approximated by using the bootstrap procedure.censored demand system, two-step estimation procedure, stratified sampling, Mexican meat demand, elasticities, adult equivalent scales, bootstrap standard errors, Consumer/Household Economics, Demand and Price Analysis, Food Consumption/Nutrition/Food Safety, Q11,
Forecast and Simulation Analysis of Mexican Meat Consumption at the Table Cut Level: Impacts on U.S. Exports.
An analysis of current and forecasted Mexican meat consumption and imports is presented at the table cut level of disaggregation. Unlike previous studies, this study uses adult equivalence scales, a price imputation approach, a consistent censored demand system, and estimation techniques from stratified sampling. The results indicate that most Mexican consumption and imports of table cuts of meats grow at different rates. In addition, Mexico seems to be following the U.S. preferences for beef cuts, but it does not seem to be following the U.S. preferences for chicken cuts. The study may help U.S. and Canadian meat exporters in forecasting future exports to Mexico, conducting long-term meat investment decisions, or identifying trends in the consumption of specific table cuts of meats.forecast of Mexican meat consumption, forecast of Mexican imports, U.S. meat exports to Mexico, Mexican meat demand elasticities, meat analysis at the table cut level, censored demand system, two-step estimation procedure, stratified sampling, Agribusiness, Agricultural and Food Policy, Consumer/Household Economics, Demand and Price Analysis, Food Consumption/Nutrition/Food Safety, International Relations/Trade, Q11,
Logic programming and metadata specifications
Artificial intelligence (AI) ideas and techniques are critical to the development of intelligent information systems that will be used to collect, manipulate, and retrieve the vast amounts of space data produced by 'Missions to Planet Earth.' Natural language processing, inference, and expert systems are at the core of this space application of AI. This paper presents logic programming as an AI tool that can support inference (the ability to draw conclusions from a set of complicated and interrelated facts). It reports on the use of logic programming in the study of metadata specifications for a small problem domain of airborne sensors, and the dataset characteristics and pointers that are needed for data access
The effect of IFN-gamma and TNF-alpha on the eosinophilic differentiation and NADPH oxidase activation of human HL-60 clone 15 cells
The aim of this study was to investigate the effect of interferon-gamma (IFN-gamma) and tumor necrosis factor-alpha (TNF-alpha) on NADPH oxidase activity and gp91-phox gene expression in HL-60 clone 15 cells as they differentiate along the eosinophilic lineage. The results were compared to the eosoniphilic inducers interleukin-5 (IL-5) and butyric acid. IFN-gamma (100 U/ml) and TNF-alpha (1000 U/ml) or IL-5 (200 pM) caused a significant increase in the expression of the eosinophil peroxidase (EPO) and the major basic protein (MBP) genes. Similar results were observed when the cells were cultured with 0.5 mM butyric acid for 5 days. IFN-gamma (100 U/ml) and TNF-alpha (1000 U/ml) also caused a significant increase in superoxide release by HL-60 clone 15 cells after 2 days compared with control or with butyric acid-induced cells. After 5 days, these cytokines and butyric acid induced an even stronger release of superoxide. HL-60 clone 15 cells cultured with IFN-gamma and TNF-alpha for 2 days showed a significant increase in gp91-phox gene expression. We conclude that IFN-gamma and TNF-alpha are sufficient to induce the differentiation of HL-60 clone 15 cells to the eosinophilic lineage and to upregulate gp91-phox gene expression and activity of the NADPH oxidase system
Jets, knots and tails in planetary nebulae: NGC 3918, K 1-2 and Wray 17-1
We analyze optical images and high-resolution, long-slit spectra of three
planetary nebulae which possess collimated, low-ionization features. NGC 3918
is composed of an inner, spindle-shaped shell mildly inclined with respect to
the plane of the sky. Departing from the polar regions of this shell, we find a
two-sided jet expanding with velocities which increase linearly with distance
from 50 to 100 km/s. The jet is probably coeval with the inner shell (with the
age of approximately 1000 D yr, where D is the distance in kpc), suggesting
that its formation should be ascribed to the same dynamical processes which
also shaped the main nebula, and not to a more recent mass loss episode. We
discuss the formation of the aspherical shell and jet in the light of current
hydrodynamical and magnetohydrodynamical theories. K 1-2 is a planetary nebula
with a close binary nucleus which shows a collimated string of knots embedded
in a diffuse, elliptical shell. The knots expand with a velocity similar to
that of the elliptical nebula (25 km/s), except for an extended tail located
out of the main nebula, which linearly accelerates up to 45 km/s. We estimate
an inclination on the line of the sight of 40 degres for the string of knots;
once the orientation of the orbit is also determined, this information will
allow us to test the prediction of current theories of the occurrence of polar
jets from close binary systems. Wray 17-1 has a complex morphology, showing two
pairs of low-ionization structures located in almost perpendicular directions
from the central star, and embedded in a large, diffuse nebula. The two pairs
show notable similarities and differences, and their origin is very puzzling.Comment: 20 pages plus 10 figures. ApJ recently published (ApJ 523, 721
(1999)
In Vitro and In Vivo Anti-Schistosomal Activity of the Alkylphospholipid Analog Edelfosine
BACKGROUND: Schistosomiasis is a parasitic disease caused by trematodes of the genus Schistosoma. Five species of Schistosoma are known to infect humans, out of which S. haematobium is the most prevalent, causing the chronic parasitic disease schistosomiasis that still represents a major problem of public health in many regions of the world and especially in tropical areas, leading to serious manifestations and mortality in developing countries. Since the 1970s, praziquantel (PZQ) is the drug of choice for the treatment of schistosomiasis, but concerns about relying on a single drug to treat millions of people, and the potential appearance of drug resistance, make identification of alternative schistosomiasis chemotherapies a high priority. Alkylphospholipid analogs (APLs), together with their prototypic molecule edelfosine (EDLF), are a family of synthetic antineoplastic compounds that show additional pharmacological actions, including antiparasitic activities against several protozoan parasites. METHODOLOGY/PRINCIPAL FINDINGS: We found APLs ranked edelfosine> perifosine> erucylphosphocholine> miltefosine for their in vitro schistosomicidal activity against adult S. mansoni worms. Edelfosine accumulated mainly in the worm tegument, and led to tegumental alterations, membrane permeabilization, motility impairment, blockade of male-female pairing as well as induction of apoptosis-like processes in cells in the close vicinity to the tegument. Edelfosine oral treatment also showed in vivo schistosomicidal activity and decreased significantly the egg burden in the liver, a key event in schistosomiasis. CONCLUSIONS/SIGNIFICANCE: Our data show that edelfosine is the most potent APL in killing S. mansoni adult worms in vitro. Edelfosine schistosomicidal activity seems to depend on its action on the tegumental structure, leading to tegumental damage, membrane permeabilization and apoptosis-like cell death. Oral administration of edelfosine diminished worm and egg burdens in S. mansoni-infected CD1 mice. Here we report that edelfosine showed promising antischistosomal properties in vitro and in vivo
Duration and quality of sleep and risk of physical function impairment and disability in older adults: Results from the ENRICA and ELSA Cohorts
Sleep duration and quality have been associated with poor physical function, but both the temporality of the association and the independence of sleep duration and quality are unclear. We examined the prospective association of sleep duration and quality with physical function impairment and disability in older adults. Data were taken from participants in the Seniors-ENRICA (2012-2015, n= 1,773) and in the ELSA cohort (waves 4 and 6, n=4,885) aged ≥60 years. Sleep duration and quality were self-reported. Physical function impairment and disability was obtained either from self-reports (ENRICA and ELSA) or from performance assessment (ENRICA). Logistic regression models were adjusted for potential confounders. After a follow-up of 2.0-2.8 years, no association was found between changes in sleep duration and physical function impairment or disability. However, in both studies, poor general sleep quality was linked to higher risk of impaired agility [OR: 1.93 (95% CI: 1.30-2.86) in Seniors-ENRICA and 1.65 (1.24-2.18) in ELSA study] and mobility [1.46 (0.98-2.17) in Seniors-ENRICA and 1.59 (1.18-2.15) in ELSA study]. Poor general sleep quality was also associated with decreased physical component summary (PCS) [1.39 (1.05-1.83)], disability in instrumental activities of daily living [1.59 (0.97-2.59)] and in basic activities of daily living [1.73 (1.14-2.64)] in Seniors-ENRICA. In addition, compared to those with no sleep complaints, participants with 2 or more sleep complaints had greater risk of impaired agility, impaired mobility, decreased PCS and impaired lower extremity function in both cohorts. Poor sleep quality was associated with higher risk of physical impairment and disability in older adults from Spain and from EnglandThe Seniors-ENRICA study was supported by FIS grants 13/0288, 16/609 and 16/1512 (Instituto de Salud Carlos III, State Secretary of R+D+I, and FEDER/FSE), the FRAILOMIC Initiative (FP7-HEALTH-2012-Proposal no. 305483-2), the ATHLOS project (EU H2020- Project ID: 635316) and the JPI HDHL (SALAMANDER project
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