811 research outputs found
Remittances and child labor in Bolivia
This article explores the effect of remittances on the prevalence and intensity of child labor in Bolivia. Using household survey data, we find that children in remittance-receiving households are less likely to be actively supplying labor, and the number of hours worked per week declines with the size of remittances received. The size of the impact varies between urban and rural households. Remittances to urban households have a larger impact on moving children completely out of the labor force, but a smaller increase in remittance size is needed for an equal reduction in number of hours worked in rural areas
Safety of improved Milbond-TX mycotoxin binder when fed to broiler breeders above recommended levels
An increasing concern in poultry nutrition is the effects of mycotoxins in contaminated grain. Several new products have come onto the market that chemically bind these toxins preventing mycotoxicosis. However, many of these products have not been tested for safety if accidently overfed to broiler breeders. In order to simulate a feed mixing error at a feed mill, Improved Milbond-TX® was overfed to broiler breeders to see if this would cause any negative effects on bird performance. A typical corn-soybean based diet supplemented with Milbond-TX mycotoxin binder at three different levels of inclusion (0%, 0.5%, and 1%) was fed to 300 broiler breeder hens. Data were collected on egg production, egg weights, hatchability, fertility, and chick weights from 24 to 35 weeks of age. Eggs per hen housed were not significantly different between the three treatments. The differences in egg weights, hatchability, fertility, and chick weights were also insignificant among the three treatments. We were able to conclude that overfeeding Improved Milbond-TX had no negative effect on bird performance and is safe to feed at a level of up to 1%
Radar Range Sidelobe Reduction Using Adaptive Pulse Compression Technique
Pulse compression has been widely used in radars so that low-power, long RF pulses can be transmitted, rather than a highpower short pulse. Pulse compression radars offer a number of advantages over high-power short pulsed radars, such as no need of high-power RF circuitry, no need of high-voltage electronics, compact size and light weight, better range resolution, and better reliability. However, range sidelobe associated with pulse compression has prevented the use of this technique on spaceborne radars since surface returns detected by range sidelobes may mask the returns from a nearby weak cloud or precipitation particles. Research on adaptive pulse compression was carried out utilizing a field-programmable gate array (FPGA) waveform generation board and a radar transceiver simulator. The results have shown significant improvements in pulse compression sidelobe performance. Microwave and millimeter-wave radars present many technological challenges for Earth and planetary science applications. The traditional tube-based radars use high-voltage power supply/modulators and high-power RF transmitters; therefore, these radars usually have large size, heavy weight, and reliability issues for space and airborne platforms. Pulse compression technology has provided a path toward meeting many of these radar challenges. Recent advances in digital waveform generation, digital receivers, and solid-state power amplifiers have opened a new era for applying pulse compression to the development of compact and high-performance airborne and spaceborne remote sensing radars. The primary objective of this innovative effort is to develop and test a new pulse compression technique to achieve ultrarange sidelobes so that this technique can be applied to spaceborne, airborne, and ground-based remote sensing radars to meet future science requirements. By using digital waveform generation, digital receiver, and solid-state power amplifier technologies, this improved pulse compression technique could bring significant impact on future radar development. The novel feature of this innovation is the non-linear FM (NLFM) waveform design. The traditional linear FM has the limit (-20 log BT -3 dB) for achieving ultra-low-range sidelobe in pulse compression. For this study, a different combination of 20- or 40-microsecond chirp pulse width and 2- or 4-MHz chirp bandwidth was used. These are typical operational parameters for airborne or spaceborne weather radars. The NLFM waveform design was then implemented on a FPGA board to generate a real chirp signal, which was then sent to the radar transceiver simulator. The final results have shown significant improvement on sidelobe performance compared to that obtained using a traditional linear FM chirp
Covariant equations for the three-body bound state
The covariant spectator (or Gross) equations for the bound state of three
identical spin 1/2 particles, in which two of the three interacting particles
are always on shell, are developed and reduced to a form suitable for numerical
solution. The equations are first written in operator form and compared to the
Bethe-Salpeter equation, then expanded into plane wave momentum states, and
finally expanded into partial waves using the three-body helicity formalism
first introduced by Wick. In order to solve the equations, the two-body
scattering amplitudes must be boosted from the overall three-body rest frame to
their individual two-body rest frames, and all effects which arise from these
boosts, including the Wigner rotations and rho-spin decomposition of the
off-shell particle, are treated exactly. In their final form, the equations
reduce to a coupled set of Faddeev-like double integral equations with
additional channels arising from the negative rho-spin states of the off-shell
particle.Comment: 57 pages, RevTeX, 6 figures, uses epsf.st
A Bayesian method for evaluating and discovering disease loci associations
Background: A genome-wide association study (GWAS) typically involves examining representative SNPs in individuals from some population. A GWAS data set can concern a million SNPs and may soon concern billions. Researchers investigate the association of each SNP individually with a disease, and it is becoming increasingly commonplace to also analyze multi-SNP associations. Techniques for handling so many hypotheses include the Bonferroni correction and recently developed Bayesian methods. These methods can encounter problems. Most importantly, they are not applicable to a complex multi-locus hypothesis which has several competing hypotheses rather than only a null hypothesis. A method that computes the posterior probability of complex hypotheses is a pressing need. Methodology/Findings: We introduce the Bayesian network posterior probability (BNPP) method which addresses the difficulties. The method represents the relationship between a disease and SNPs using a directed acyclic graph (DAG) model, and computes the likelihood of such models using a Bayesian network scoring criterion. The posterior probability of a hypothesis is computed based on the likelihoods of all competing hypotheses. The BNPP can not only be used to evaluate a hypothesis that has previously been discovered or suspected, but also to discover new disease loci associations. The results of experiments using simulated and real data sets are presented. Our results concerning simulated data sets indicate that the BNPP exhibits both better evaluation and discovery performance than does a p-value based method. For the real data sets, previous findings in the literature are confirmed and additional findings are found. Conclusions/Significance: We conclude that the BNPP resolves a pressing problem by providing a way to compute the posterior probability of complex multi-locus hypotheses. A researcher can use the BNPP to determine the expected utility of investigating a hypothesis further. Furthermore, we conclude that the BNPP is a promising method for discovering disease loci associations. © 2011 Jiang et al
Impact of Pediatric Acute Otitis Media on Child and Parental Quality of Life and Associated Productivity Loss in Malaysia: A Prospective Observational Study
BACKGROUND: Acute otitis media (AOM) affects both child and parental quality of life (QoL). Data on QoL associated with AOM in Malaysia is sparse, and the burden of indirect costs have not been previously reported. OBJECTIVE: To determine the effect of pediatric AOM on child and parental QoL in Malaysia and its economic impact (indirect costs). METHODS: We utilized a set of QoL questionnaires (PAR-AOM-QOL, OM-6, and EQ-5D) combined with questions addressing work/productivity loss and financial costs associated with caring for a child during his or her illness in an observational, multicenter, prospective study. RESULTS: One hundred and ten AOM patients aged ≤5 years were included in the analysis. The majority of respondents were the patient’s mother. Parental QoL was negatively affected for both emotional and daily disturbance scales, but the level of disturbance was low. Using OM-6, the greatest negative impact was on the child’s QoL, followed by caregiver concerns, physical suffering, and emotional distress. Using EQ-5D, a moderately positive relationship between parents’ emotional disturbance and daily disturbance, and a weak, negative correlation between parental emotional disturbance and parental health status was found. Parents with paid employment took an average of 21 h from work to care for their child, at an average cost of 321.8 Malaysian ringgit (US$97) in addition to their contribution to direct medical costs. Productivity losses whilst at work, uncompensated wage losses, and leisure time losses are also reported. CONCLUSIONS: This study found that AOM is associated with some negative impact on parental QoL and significant economic impact at both patient and societal levels. The findings provide useful data on healthcare resource utilization and disease burden of AOM in Malaysia. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s40801-016-0099-9) contains supplementary material, which is available to authorized users
Does living by the coast improve health and wellbeing?
This is the author’s version of a work that was accepted for publication in Health and Place. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Health and Place,vol. 18 (5)(2012) DOI:0.1016/j.healthplace.2012.06.015It is often assumed that spending time by the coast leads to better health and wellbeing, but there is strikingly little evidence regarding specific effects or mechanisms to support such a view. We analysed small-area census data for the population of England, which indicate that good health is more prevalent the closer one lives to the coast. We also found that, consistent with similar analyses of greenspace accessibility, the positive effects of coastal proximity may be greater amongst more socio-economically deprived communities. We hypothesise that these effects may be due to opportunities for stress reduction and increased physical activity
Experimental Study of Saddle Point of Attachment in Laminar Juncture Flow
An experimental study of laminar horseshoe vortex flows upstream of a cylinder/flat plate juncture has been conducted to verify the existence of saddle-point-of-attachment topologies. In the classical depiction of this flowfield, a saddle point of separation exists on the flat plate upstream of the cylinder, and the boundary layer separates from the surface. Recent computations have indicated that the topology may actually involve a saddle point of attachment on the surface and additional singular points in the flow. Laser light sheet flow visualizations have been performed on the symmetry plane and crossflow planes to identify the saddle-point-of-attachment flowfields. The visualizations reveal that saddle-point-of-attachment topologies occur over a range of Reynolds numbers in both single and multiple vortex regimes. An analysis of the flow topologies is presented that describes the existence and evolution of the singular points in the flowfield
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