Determinants of participation in contract farming in pig production in Northern Vietnam

The rapid growth in demand for pork in Viet Nam presents an opportunity for rural households raising pigs to improve their incomes. This market potential could be exploited to improve incomes of rural smallholders through institutional arrangements that provide improved access to livestock markets and services, through formal and informal contract arrangements. Contract arrangements, however, have explicit and implicit barriers to entry that tend to exclude smallholders, depending on the nature of the contracts. Based on data from a field survey conducted in four provinces in Northern Viet Nam in 2005-06, comprising a sample of 400 pig raising households (200 independent producers, 166 farmers with informal contracts, and 34 farmers with formal contracts with a large integrator), a multinomial logit model was used to identify the factors that determine the likelihood of engagement in formal or informal contracts. A simple probit model was subsequently developed for the determinants of engagement in informal contract arrangements. Results indicate that farmers with higher levels of education and larger physical asset holdings are more likely to be engaged in formal contracts. The latter are largely limited to large-scale farmers (with mean holdings of about 600 pigs per farm) that specialized in pig fattening. In contrast, informal contracts are less exclusionary of smallholder producers. Households with higher levels of education, managing full-cycle pig operations, and with pig production being a main occupation, are more likely to engage in informal contracts, than remain independent producers. However, rather than size of physical assets, social capital appears to be a more important determinant of engaging in informal contracts. Providing a supportive policy and institutional environment for various informal contracting arrangements in pig production and marketing could improve access to markets and services by rural smallholder pig producers

Isolated oxygen defects in 3C- and 4H-SiC: A theoretical study

Ab initio calculations in the local-density approximation have been carried out in SiC to determine the possible configurations of the isolated oxygen impurity. Equilibrium geometry and occupation levels were calculated. Substitutional oxygen in 3C-SiC is a relatively shallow effective mass like double donor on the carbon site (O-C) and a hyperdeep double donor on the Si site (O-Si). In 4H-SiC O-C is still a double donor but with a more localized electron state. In 3C-SiC O-C is substantially more stable under any condition than O-Si or interstitial oxygen (O-i). In 4H-SiC O-C is also the most stable one except for heavy n-type doping. We propose that O-C is at the core of the electrically active oxygen-related defect family found by deep level transient spectroscopy in 4H-SiC. The consequences of the site preference of oxygen on the SiC/SiO2 interface are discussed

Drug-Related Problems in Coronary Artery Diseases

Coronary artery disease (CAD) remains the leading cause of mortality among cardiovascular diseases, responsible for 16% of the world’s total deaths. According to a statistical report published in 2020, the global prevalence of CAD was estimated at 1655 per 100,000 people and is predicted to exceed 1845 by 2030. Annually, in the United States, CAD accounts for approximately 610,000 deaths and costs more than 200 billion dollars for healthcare services. Most patients with CAD need to be treated over long periods with a combination of drugs. Therefore, the inappropriate use of drugs, or drug-related problems (DRPs), can lead to many consequences that affect these patients’ health, including decreased quality of life, increased hospitalization rates, prolonged hospital stays, increased overall health care costs, and even increased risk of morbidity and mortality. DRPs are common in CAD patients, with a prevalence of over 60%. DRPs must therefore be noticed and recognized by healthcare professionals. This chapter describes common types and determinants of DRPs in CAD patients and recommends interventions to limit their prevalence

The genetic architecture of the human cerebral cortex

INTRODUCTION The cerebral cortex underlies our complex cognitive capabilities. Variations in human cortical surface area and thickness are associated with neurological, psychological, and behavioral traits and can be measured in vivo by magnetic resonance imaging (MRI). Studies in model organisms have identified genes that influence cortical structure, but little is known about common genetic variants that affect human cortical structure. RATIONALE To identify genetic variants associated with human cortical structure at both global and regional levels, we conducted a genome-wide association meta-analysis of brain MRI data from 51,665 individuals across 60 cohorts. We analyzed the surface area and average thickness of the whole cortex and 34 cortical regions with known functional specializations. RESULTS We identified 306 nominally genome-wide significant loci (P < 5 × 10−8) associated with cortical structure in a discovery sample of 33,992 participants of European ancestry. Of the 299 loci for which replication data were available, 241 loci influencing surface area and 14 influencing thickness remained significant after replication, with 199 loci passing multiple testing correction (P < 8.3 × 10−10; 187 influencing surface area and 12 influencing thickness). Common genetic variants explained 34% (SE = 3%) of the variation in total surface area and 26% (SE = 2%) in average thickness; surface area and thickness showed a negative genetic correlation (rG = −0.32, SE = 0.05, P = 6.5 × 10−12), which suggests that genetic influences have opposing effects on surface area and thickness. Bioinformatic analyses showed that total surface area is influenced by genetic variants that alter gene regulatory activity in neural progenitor cells during fetal development. By contrast, average thickness is influenced by active regulatory elements in adult brain samples, which may reflect processes that occur after mid-fetal development, such as myelination, branching, or pruning. When considered together, these results support the radial unit hypothesis that different developmental mechanisms promote surface area expansion and increases in thickness. To identify specific genetic influences on individual cortical regions, we controlled for global measures (total surface area or average thickness) in the regional analyses. After multiple testing correction, we identified 175 loci that influence regional surface area and 10 that influence regional thickness. Loci that affect regional surface area cluster near genes involved in the Wnt signaling pathway, which is known to influence areal identity. We observed significant positive genetic correlations and evidence of bidirectional causation of total surface area with both general cognitive functioning and educational attainment. We found additional positive genetic correlations between total surface area and Parkinson’s disease but did not find evidence of causation. Negative genetic correlations were evident between total surface area and insomnia, attention deficit hyperactivity disorder, depressive symptoms, major depressive disorder, and neuroticism. CONCLUSION This large-scale collaborative work enhances our understanding of the genetic architecture of the human cerebral cortex and its regional patterning. The highly polygenic architecture of the cortex suggests that distinct genes are involved in the development of specific cortical areas. Moreover, we find evidence that brain structure is a key phenotype along the causal pathway that leads from genetic variation to differences in general cognitive function

Nonproportionality of NaI(Tl) scintillation detector for dark matter search experiments

We present a comprehensive study of the nonproportionality of NaI(Tl) scintillation detectors within the context of dark matter search experiments. Our investigation, which integrates COSINE-100 data with supplementary γ spectroscopy, measures light yields across diverse energy levels from full-energy γ peaks produced by the decays of various isotopes. These γ peaks of interest were produced by decays supported by both long and short-lived isotopes. Analyzing peaks from decays supported only by short-lived isotopes presented a unique challenge due to their limited statistics and overlapping energies, which was overcome by a e-mail: [email protected] b e-mail: [email protected] (corresponding author) long-term data collection and a time-dependent analysis. A key achievement is the direct measurement of the 0.87 keV light yield, resulting from the cascade following electron capture decay of 22Na from internal contamination. This measurement, previously accessible only indirectly, deepens our understanding of NaI(Tl) scintillator behavior in the region of interest for dark matter searches. This study holds substantial implications for background modeling and the interpretation of dark matter signals in NaI(Tl) experiments

Search for inelastic WIMP-iodine scattering with COSINE-100

We report the results of a search for inelastic scattering of weakly interacting massive particles (WIMPs) off I127 nuclei using NaI(Tl) crystals with a data exposure of 97.7 kg·years from the COSINE-100 experiment. The signature of inelastic WIMP-I127 scattering is a nuclear recoil accompanied by a 57.6 keV γ-ray from the prompt deexcitation, producing a more energetic signal compared to the typical WIMP nuclear recoil signal. We found no evidence for this inelastic scattering signature and set a 90% confidence level upper limit on the WIMP-proton spin-dependent, inelastic scattering cross section of 1.2×10-37 cm2 at the WIMP mass 500 GeV/c2