A Model for the Soil Freezing Characteristic Curve That Represents the Dominant Role of Salt Exclusion

The phenomenon of freezing point depression in frozen soils results in the co-existence of ice and liquid water in soil pores at temperatures below 273.15 K (0°C), and is thought to have two causes: (a) capillary and adsorption effects, where the phase transition relationship is modified due to soil-air-water-ice interactions, and (b) solute effects, where the presence of salts lowers the freezing temperature. The soil freezing characteristic curve (SFC) characterizes the relationship between liquid water content and temperature in frozen soils. Most hydrological models represent the SFC using only capillary and adsorption effects with a relationship known as the Generalized Clapeyron Equation (GCE). In this study, we develop and test a salt exclusion model for characterizing the SFC, comparing this with the GCE-based model and a combined salt-GCE effect model. We test these models against measured SFCs in laboratory and field experiments with diverse soil textures and salinities. We consistently found that the GCE-based models under-predicted freezing-point depression. We were able to match the observations with the salt exclusion model and the combined model, suggesting that salinity is a dominant control on the SFC in real soils that always contain solutes. In modeling applications where the salinity is unknown, the soil bulk solute concentration can be treated as a single fitting parameter. Improved characterization of the SFC may result in improvements in coupled mass-heat transport models for simulating hydrological processes in cold regions, particularly the hydraulic properties of frozen soils and the hydraulic head in frozen soils that drives cryosuction

Enhancing farmers’ access to technology for increased rice productivity in Ghana

A two-year emergency rice (Oryza sativa L.) initiative was launched in 2009 in response to the globalrice crises in 2008. The objective of this initiative in Ghana was to increase rice productivity in order toimprove food security. Project activities included planning sessions, demonstrations, training coursesand community seed production. The project made remarkable progress in enhancing access to qualityseed and fertilizer for over 12,600 farmers while expanding knowledge of best-bet productiontechnologies. Farmers produced 28,663 Mt of paddy which was 16,841 Mt above what they normallyproduced without project intervention. Average yield increased by 92% and also 4,093 women farmersconstituting about 32.4% of the total number of participating farmers benefited directly from the project.Seed fairs, rural radios and audio-visual broadcasts on improved rice production technologies wereused to reach non-participating farmers. The combination of methods that stimulated adoption ofimproved rice production technology was effective in achieving both increased paddy yields andhousehold income. We conclude that investment in rice technology transfer and production effortsduring the two-year period was well justified

Partnership for improved access to agro-inputs and technology: Some experiences from the emergency rice initiative project in Ghana

A two-year emergency rice (Oryza sativa L.) initiative project was launched in 2009 in response to the global rice crisis in 2008. The objective of this initiative in Ghana was to increase rice productivity in order to improve food security. Project activities included seed fairs, dissemination of information on improved production technologies using videos and rural radios, training of agro-input dealers,extension officers and farmers as well as promotion of best-bet practices through field demonstrations.The project made progress in strengthening the ability of agro-input dealers to create business linkages with input suppliers and extend their retail networks to rice farmers. Overall, 34 agro-input dealers were trained, in collaboration with the Ghana Agro-dealer Development project, on agro-input business management, product knowledge and rice production. Thirteen agro-input dealers were assisted to access credit for business development. Better financed, trained agro-dealers were then able to provide over 12,600 rice farmers with improved seed, mineral fertilizers, technical advice on agro-input use and the promotion of improved agronomic practices through field demonstrations. Some agro-input dealers even provided free inputs for the conduct of demonstrations on new products and good agronomic practices. On average, fertilizer application in demonstration trials increased paddy yields by 68 to 80%over the farmer practice of no fertilizer application. For the participating farmers, there were significant increases in rice paddy yields, reductions in the cost of operations and improvements in the contribution of rice to household incomes. The results suggest that a holistic and multi-stakeholder partnership is an efficient way to improve the access by small-holder resource-poor farmers to agro-inputs and technology and also an effective way to grow the rural agro-input marke

Maternal side-effects after multiple courses of antenatal corticosteroids (MACS): the three-month follow-up of women in the randomized controlled trial of MACS for preterm birth study.

OBJECTIVE: A single course of antenatal corticosteroids (ACS) is associated with a reduction in respiratory distress syndrome and neonatal death. Multiple Courses of Antenatal Corticosteroids Study (MACS), a study involving 1858 women, was a multicentre randomized placebo-controlled trial of multiple courses of ACS, given every 14 days until 33+6 weeks or birth, whichever came first. The primary outcome of the study, a composite of neonatal mortality and morbidity, was similar for the multiple ACS and placebo groups (12.9% vs. 12.5%), but infants exposed to multiple courses of ACS weighed less, were shorter, and had smaller head circumferences. Thus for women who remain at increased risk of preterm birth, multiple courses of ACS (every 14 days) are not recommended. Chronic use of corticosteroids is associated with numerous side effects including weight gain and depression. The aim of this postpartum assessment was to ascertain if multiple courses of ACS were associated with maternal side effects. METHODS: Three months postpartum, women who participated in MACS were asked to complete a structured questionnaire that asked about maternal side effects of corticosteroid use during MACS and included the Edinburgh Postnatal Depression Scale. Women were also asked to evaluate their study participation. RESULTS: Of the 1858 women randomized, 1712 (92.1%) completed the postpartum questionnaire. There were no significant differences in the risk of maternal side effects between the two groups. Large numbers of women met the criteria for postpartum depression (14.1% in the ACS vs. 16.0% in the placebo group). Most women (94.1%) responded that they would participate in the trial again. CONCLUSION: In pregnancy, corticosteroids are given to women for fetal lung maturation and for the treatment of various maternal diseases. In this international multicentre randomized controlled trial, multiple courses of ACS (every 14 days) were not associated with maternal side effects, and the majority of women responded that they would participate in such a study again

Common Genetic Variation In Cellular Transport Genes and Epithelial Ovarian Cancer (EOC) Risk

Contains fulltext : 154822.PDF (publisher's version ) (Open Access)BACKGROUND: Defective cellular transport processes can lead to aberrant accumulation of trace elements, iron, small molecules and hormones in the cell, which in turn may promote the formation of reactive oxygen species, promoting DNA damage and aberrant expression of key regulatory cancer genes. As DNA damage and uncontrolled proliferation are hallmarks of cancer, including epithelial ovarian cancer (EOC), we hypothesized that inherited variation in the cellular transport genes contributes to EOC risk. METHODS: In total, DNA samples were obtained from 14,525 case subjects with invasive EOC and from 23,447 controls from 43 sites in the Ovarian Cancer Association Consortium (OCAC). Two hundred seventy nine SNPs, representing 131 genes, were genotyped using an Illumina Infinium iSelect BeadChip as part of the Collaborative Oncological Gene-environment Study (COGS). SNP analyses were conducted using unconditional logistic regression under a log-additive model, and the FDR q<0.2 was applied to adjust for multiple comparisons. RESULTS: The most significant evidence of an association for all invasive cancers combined and for the serous subtype was observed for SNP rs17216603 in the iron transporter gene HEPH (invasive: OR = 0.85, P = 0.00026; serous: OR = 0.81, P = 0.00020); this SNP was also associated with the borderline/low malignant potential (LMP) tumors (P = 0.021). Other genes significantly associated with EOC histological subtypes (p<0.05) included the UGT1A (endometrioid), SLC25A45 (mucinous), SLC39A11 (low malignant potential), and SERPINA7 (clear cell carcinoma). In addition, 1785 SNPs in six genes (HEPH, MGST1, SERPINA, SLC25A45, SLC39A11 and UGT1A) were imputed from the 1000 Genomes Project and examined for association with INV EOC in white-European subjects. The most significant imputed SNP was rs117729793 in SLC39A11 (per allele, OR = 2.55, 95% CI = 1.5-4.35, p = 5.66x10-4). CONCLUSION: These results, generated on a large cohort of women, revealed associations between inherited cellular transport gene variants and risk of EOC histologic subtypes

Common Genetic Variation In Cellular Transport Genes and Epithelial Ovarian Cancer (EOC) Risk

BACKGROUND: Defective cellular transport processes can lead to aberrant accumulation of trace elements, iron, small molecules and hormones in the cell, which in turn may promote the formation of reactive oxygen species, promoting DNA damage and aberrant expression of key regulatory cancer genes. As DNA damage and uncontrolled proliferation are hallmarks of cancer, including epithelial ovarian cancer (EOC), we hypothesized that inherited variation in the cellular transport genes contributes to EOC risk. METHODS: In total, DNA samples were obtained from 14,525 case subjects with invasive EOC and from 23,447 controls from 43 sites in the Ovarian Cancer Association Consortium (OCAC). Two hundred seventy nine SNPs, representing 131 genes, were genotyped using an Illumina Infinium iSelect BeadChip as part of the Collaborative Oncological Gene-environment Study (COGS). SNP analyses were conducted using unconditional logistic regression under a log-additive model, and the FDR q<0.2 was applied to adjust for multiple comparisons. RESULTS: The most significant evidence of an association for all invasive cancers combined and for the serous subtype was observed for SNP rs17216603 in the iron transporter gene HEPH (invasive: OR = 0.85, P = 0.00026; serous: OR = 0.81, P = 0.00020); this SNP was also associated with the borderline/low malignant potential (LMP) tumors (P = 0.021). Other genes significantly associated with EOC histological subtypes (p<0.05) included the UGT1A (endometrioid), SLC25A45 (mucinous), SLC39A11 (low malignant potential), and SERPINA7 (clear cell carcinoma). In addition, 1785 SNPs in six genes (HEPH, MGST1, SERPINA, SLC25A45, SLC39A11 and UGT1A) were imputed from the 1000 Genomes Project and examined for association with INV EOC in white-European subjects. The most significant imputed SNP was rs117729793 in SLC39A11 (per allele, OR = 2.55, 95% CI = 1.5-4.35, p = 5.66x10-4). CONCLUSION: These results, generated on a large cohort of women, revealed associations between inherited cellular transport gene variants and risk of EOC histologic subtypes