Small-scale farming, marketing and organisational support received since 2002 on the Mooi River irrigation scheme in Muden, Central KwaZulu-Natal.

Thesis (M.Soc.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2007.Small-scale farming plays a significant role in rural people's lives. Small-scale farming contributes to food production, household income and to the employment of people in rural South Africa. They also face many constraints in their farming activities such as lack of capital, of quality seed, of fertilizer, of equipment, of water for irrigation, of technology, of storage facilities, of transport, of market, of training and finance. These in fact, limit farmers in their farming activities and affect their farming outputs. In this regard, small-scale farmers rely on government, private companies and NGOs for agricultural support. These are often insufficient as farmers still face many challenges in their farming and their needs tend not to change for the better. This study investigated whether there had been changes or improvements in small-scale farming on the Mooi River irrigation scheme in Muden over the past three years since the previous baseline survey was conducted in 2002. The study also investigated the activities of farmers' associations, Provincial Department of Agriculture and Environmental Affairs (DAEA) and NGOs in Muden and determined the activities that were needed for small-scale farmers to overcome their constraints. The research took place amongst small-scale farmers from block 6, 12 and 15 that were randomly selected from 15 blocks on Mooi River irrigation scheme in 2002. Convenience sampling of individuals was done resulting in an estimated 25 percent sample of the farmer population. A household survey was conducted with each participant to provide data on demographic detail. Aspects of the sustainable livelihood analysis data tool were used to guide this data collection and to encourage the farmers to identify their assets in terms of people in households, age, education level, skills, contribution to farming and off-farm income. Focus group discussions were also conducted with each selected block, guided by sustainable livelihoods analysis in order for the farmers to identify their assets, institutions as well as constraints; and strategies to improve their small-scale farming. The findings of this study showed that since 2002 the farmers' household size decreased which resulted in decreased family labour. In addition, the findings reflected that few young people were involved in farming. The level of illiteracy was still high among small-scale farmers and the few off-farm income-earning activities for farmers did not change for the better. Furthermore, off-farm income and farmers' markets to sell fresh produce decreased. The farmers had more skills and acquired more tools for farming. But accessing modern tools such as a tractor, bakkie, and water pump were still a challenge for the farmers. The findings showed that the farmers on the Mooi River irrigation scheme obtained support from farmers' associations, NGOs, and Provincial Department of Agriculture and Environmental Affairs which assisted them in their farming activities. Though the farmers obtained some support from the above-mentioned institutions, their farming constraints still persisted. As a result, the farmers made plans of action to minimize their constraints and improve their farming. The farmers planned to obtain fencing, undergo leadership training, use farmers' association constitutions, obtain a tractor, find markets, attend agricultural meetings, and obtain more dams, sprinklers and water pumps. This study recommends that young people be encouraged to be involved in farming through the introduction of cash crops. The study also recommends that farming be made more attractive to young people as they are stronger and more educated than their parents. In addition, it was recommended that adult education and farmers' training be introduced because there is high level of illiteracy. There was a need for job creation for farmers to be able to earn incomes to support their farming. Market opportunities, promoting credit facilities, and promoting modern technology were recommended to improve small-scale farming on the Mooi River irrigation scheme

Living in the climate crisis: young people in Uganda

Youth Futures Programme, The British Academy, School of Technology Seed Funding, University of Cambridg

p14(ARF) Prevents Proliferation of Aneuploid Cells by Inducing p53-Dependent Apoptosis

Weakening the Spindle Assembly Checkpoint by reduced expression of its components induces chromosome instability and aneuploidy that are hallmarks of cancer cells. The tumor suppressor p14(ARF) is overexpressed in response to oncogenic stimuli to stabilize p53 halting cell progression. Previously, we found that lack or reduced expression of p14(ARF) is involved in the maintenance of aneuploid cells in primary human cells, suggesting that it could be part of a pathway controlling their proliferation. To investigate this aspect further, p14(ARF) was ectopically expressed in HCT116 cells after depletion of the Spindle Assembly Checkpoint MAD2 protein that was used as a trigger for aneuploidy. p14(ARF) Re-expression reduced the number of aneuploid cells in MAD2 post-transcriptionally silenced cells. Also aberrant mitoses, frequently displayed in MAD2-depleted cells, were decreased when p14(ARF) was expressed at the same time. In addition, p14(ARF) ectopic expression in MAD2-depleted cells induced apoptosis associated with increased p53 protein levels. Conversely, p14(ARF) ectopic expression did not induce apoptosis in HCT116 p53KO cells. Collectively, our results suggest that the tumor suppressor p14(ARF) may have an important role in counteracting proliferation of aneuploid cells by activating p53-dependent apoptosis

Systematic meta-analyses and field synopsis of genetic association studies in colorectal adenomas

BackgroundLow penetrance genetic variants, primarily single nucleotide polymorphisms, have substantial influence on colorectal cancer (CRC) susceptibility. Most CRCs develop from colorectal adenomas (CRA). Here we report the first comprehensive field synopsis that catalogues all genetic association studies on CRA, with a parallel online database [http://www.chs.med.ed.ac.uk/CRAgene/].MethodsWe performed a systematic review, reviewing 9750 titles, and then extracted data from 130 publications reporting on 181 polymorphisms in 74 genes. We conducted meta-analyses to derive summary effect estimates for 37 polymorphisms in 26 genes. We applied the Venice criteria and Bayesian False Discovery Probability (BFDP) to assess the levels of the credibility of associations.ResultsWe considered the association with the rs6983267 variant at 8q24 as 'highly credible', reaching genome-wide statistical significance in at least one meta-analysis model. We identified 'less credible' associations (higher heterogeneity, lower statistical power, BFDP > 0.02) with a further four variants of four independent genes: MTHFR c.677C>T p.A222V (rs1801133), TP53 c.215C>G p.R72P (rs1042522), NQO1 c.559C>T p.P187S (rs1800566), and NAT1 alleles imputed as fast acetylator genotypes. For the remaining 32 variants of 22 genes for which positive associations with CRA risk have been previously reported, the meta-analyses revealed no credible evidence to support these as true associations.ConclusionsThe limited number of credible associations between low penetrance genetic variants and CRA reflects the lower volume of evidence and associated lack of statistical power to detect associations of the magnitude typically observed for genetic variants and chronic diseases. The CRA gene database provides context for CRA genetic association data and will help inform future research directions

Systematic meta-analyses, field synopsis and global assessment of the evidence of genetic association studies in colorectal cancer

OBJECTIVE: To provide an understanding of the role of common genetic variations in colorectal cancer (CRC) risk, we report an updated field synopsis and comprehensive assessment of evidence to catalogue all genetic markers for CRC (CRCgene2). DESIGN: We included 869 publications after parallel literature review and extracted data for 1063 polymorphisms in 303 different genes. Meta-analyses were performed for 308 single nucleotide polymorphisms (SNPs) in 158 different genes with at least three independent studies available for analysis. Scottish, Canadian and Spanish data from genome-wide association studies (GWASs) were incorporated for the meta-analyses of 132 SNPs. To assess and classify the credibility of the associations, we applied the Venice criteria and Bayesian False-Discovery Probability (BFDP). Genetic associations classified as 'positive' and 'less-credible positive' were further validated in three large GWAS consortia conducted in populations of European origin. RESULTS: We initially identified 18 independent variants at 16 loci that were classified as 'positive' polymorphisms for their highly credible associations with CRC risk and 59 variants at 49 loci that were classified as 'less-credible positive' SNPs; 72.2% of the 'positive' SNPs were successfully replicated in three large GWASs and the ones that were not replicated were downgraded to 'less-credible' positive (reducing the 'positive' variants to 14 at 11 loci). For the remaining 231 variants, which were previously reported, our meta-analyses found no evidence to support their associations with CRC risk. CONCLUSION: The CRCgene2 database provides an updated list of genetic variants related to CRC risk by using harmonised methods to assess their credibility

Systematic meta-analyses, field synopsis and global assessment of the evidence of genetic association studies in colorectal cancer

Objective: To provide an understanding of the role of common genetic variations in colorectal cancer (CRC) risk, we report an updated field synopsis and comprehensive assessment of evidence to catalogue all genetic markers for CRC (CRCgene2). Design: We included 869 publications after parallel literature review and extracted data for 1063 polymorphisms in 303 different genes. Meta-Analyses were performed for 308 single nucleotide polymorphisms (SNPs) in 158 different genes with at least three independent studies available for analysis. Scottish, Canadian and Spanish data from genome-wide association studies (GWASs) were incorporated for the meta-Analyses of 132 SNPs. To assess and classify the credibility of the associations, we applied the Venice criteria and Bayesian False-Discovery Probability (BFDP). Genetic associations classified as â € positive' and â € less-credible positive' were further validated in three large GWAS consortia conducted in populations of European origin. Results: We initially identified 18 independent variants at 16 loci that were classified as â € positive' polymorphisms for their highly credible associations with CRC risk and 59 variants at 49 loci that were classified as â € less-credible positive' SNPs; 72.2% of the â € positive' SNPs were successfully replicated in three large GWASs and the ones that were not replicated were downgraded to â € less-credible' positive (reducing the â € positive' variants to 14 at 11 loci). For the remaining 231 variants, which were previously reported, our meta-Analyses found no evidence to support their associations with CRC risk. Conclusion: The CRCgene2 database provides an updated list of genetic variants related to CRC risk by using harmonised methods to assess their credibility.</p

Potato Yield, Net Revenue and Specific Gravity Responses to Nitrogen Fertilizer under Different Canadian Agroecozones

Applying higher nitrogen (N) rates than required for optimum potato (Solanum tuberosum L.) growth leads to economic and environmental losses. The extent to which the N rate associated with maximum potato yields differs from that maximizing net revenue (NR) or potato specific gravity is not fully understood. The objectives of this three-year study (2013–2015) conducted at five sites in three Canadian provinces (MB-1; MB-2; QC-1; QC-2; PEI) (15 site-years) were to: (i) assess potato marketable yield, NR, and specific gravity responses to increasing N application; (ii) calculate the N rate maximizing marketable (Nmax) yield and NR using different statistical models. The year, N fertilizer, and their interaction were significant on marketable yield and NR except at the MB-1 site where no significant effect of N was observed. No significant yield increases were observed at a N rate above 60 kg N ha−1 at four site-years and above 120 kg N ha−1 at five site-years, implying that the current recommended N rate could be reduced. All models fitted the marketable and NR data equally based on R2, mean bias error or root mean square error and resulted in comparable predicted yield and NR values. However, Nmax values were different depending on the model with higher values being predicted by the quadratic- (161.4 to 191.9 kg N ha−1) and the quadratic plateau models (60 to 191.9 kg N ha−1), while lower Nmax values were obtained with linear plateau- (60.6 to 129.8 kg N ha−1) and Mitscherlich–Baule plateau models (60.9 to 130. 9 kg N ha−1). Nitrogen rate maximizing NR was on average 4% lower than the N rate maximizing marketable yields, except at one site where it was higher by 26 kg N ha−1 when the quadratic plus plateau model was used. Specific gravity tended to decrease with the N rate. Our study confirms trade-offs between the N rate maximizing yields or NR with that maximizing specific gravity. Nitrogen rate maximizing marketable yield and NR varies depending on the selected model