19 research outputs found
Options for Climate-Smart Agriculture at Kaptumo Site in Kenya
This report identifies and assesses climate-smart agricultural practices through participatory appraisal tools with experts and farmers, as part of the MICCA pilot project in Kaptumo, Kenya. The aim is to highlight and add climate-smart practices within the ongoing development programme which aims to integrate climate change adaptation and mitigation with improving livelihoods and productivity of the dairy farming system
THE BLENDING OF PARTICIPATORY RESEARCH AND QUANTITATIVE METHODS: WEALTH STATUS, GENDER AND THE ADOPTION OF IMPROVED FALLOWS IN ZAMBIA
Although there is increasing emphasis on targeting of improved technology towards poor and female farmers, few adoption studies assess the uptake of new practices by these groups in a comprehensive manner. In this study, community members used the wealth ranking method to identify the different wealth groups in their communities, to determine each household's wealth status, and to assess the association of wealth and different types of households with the planting of improved tree fallows, a practice for improving crop yields. There were no significant differences between the proportions of women and men planting improved fallows nor were there differences between single women and female heads of households who were married. There was some evidence of association between planting improved fallows and wealth. That 22% of the 'poor' group and 16% of the 'very poor' group were planting them suggests that there are no barriers preventing low-income households from doing so. Moreover, the proportion of females, poor, and very poor people planting improved fallows varied considerably among villages, suggesting that opportunities exist for increasing their use of technology. Whereas the use of mineral fertilizer is strongly associated with high-income, male farmers, improved fallows appear to be a gender-neutral and wealth-neutral technology. Poor farmers appreciate improved fallows because they permit them to substitute small amounts of land and labour for cash, their most scarce resource. Finally, the high degree of consistency among different key informants in classifying households among wealth groups confirmed the effectiveness and accuracy of the wealth ranking exercise.Adoption, agroforestry, Participatory research, Sesbania sesban, Research and Development/Tech Change/Emerging Technologies,
Novel Common Genetic Susceptibility Loci for Colorectal Cancer
BACKGROUND: Previous genome-wide association studies (GWAS) have identified 42 loci (P < 5âĂâ10-8) associated with risk of colorectal cancer (CRC). Expanded consortium efforts facilitating the discovery of additional susceptibility loci may capture unexplained familial risk. METHODS: We conducted a GWAS in European descent CRC cases and control subjects using a discovery-replication design, followed by examination of novel findings in a multiethnic sample (cumulative n = 163 315). In the discovery stage (36 948 case subjects/30 864 control subjects), we identified genetic variants with a minor allele frequency of 1% or greater associated with risk of CRC using logistic regression followed by a fixed-effects inverse variance weighted meta-analysis. All novel independent variants reaching genome-wide statistical significance (two-sided P < 5âĂâ10-8) were tested for replication in separate European ancestry samples (12 952 case subjects/48 383 control subjects). Next, we examined the generalizability of discovered variants in East Asians, African Americans, and Hispanics (12 085 case subjects/22 083 control subjects). Finally, we examined the contributions of novel risk variants to familial relative risk and examined the prediction capabilities of a polygenic risk score. All statistical tests were two-sided. RESULTS: The discovery GWAS identified 11 variants associated with CRC at P < 5âĂâ10-8, of which nine (at 4q22.2/5p15.33/5p13.1/6p21.31/6p12.1/10q11.23/12q24.21/16q24.1/20q13.13) independently replicated at a P value of less than .05. Multiethnic follow-up supported the generalizability of discovery findings. These results demonstrated a 14.7% increase in familial relative risk explained by common risk alleles from 10.3% (95% confidence interval [CI] = 7.9% to 13.7%; known variants) to 11.9% (95% CI = 9.2% to 15.5%; known and novel variants). A polygenic risk score identified 4.3% of the population at an odds ratio for developing CRC of at least 2.0. CONCLUSIONS: This study provides insight into the architecture of common genetic variation contributing to CRC etiology and improves risk prediction for individualized screenin
Discovery of common and rare genetic risk variants for colorectal cancer.
To further dissect the genetic architecture of colorectal cancer (CRC), we performed whole-genome sequencing of 1,439 cases and 720 controls, imputed discovered sequence variants and Haplotype Reference Consortium panel variants into genome-wide association study data, and tested for association in 34,869 cases and 29,051 controls. Findings were followed up in an additional 23,262 cases and 38,296 controls. We discovered a strongly protective 0.3% frequency variant signal at CHD1. In a combined meta-analysis of 125,478 individuals, we identified 40 new independent signals at Pâ<â5âĂâ10-8, bringing the number of known independent signals for CRC to ~100. New signals implicate lower-frequency variants, KrĂŒppel-like factors, Hedgehog signaling, Hippo-YAP signaling, long noncoding RNAs and somatic drivers, and support a role for immune function. Heritability analyses suggest that CRC risk is highly polygenic, and larger, more comprehensive studies enabling rare variant analysis will improve understanding of biology underlying this risk and influence personalized screening strategies and drug development.Goncalo R Abecasis has received compensation from 23andMe and Helix. He is currently an employee of Regeneron Pharmaceuticals. Heather Hampel performs collaborative research with Ambry Genetics, InVitae Genetics, and Myriad Genetic Laboratories, Inc., is on the scientific advisory board for InVitae Genetics and Genome Medical, and has stock in Genome Medical. Rachel Pearlman has participated in collaborative funded research with Myriad Genetics Laboratories and Invitae Genetics but has no financial competitive interest
Deciphering colorectal cancer genetics through multi-omic analysis of 100,204 cases and 154,587 controls of European and east Asian ancestries
In the version of this article initially published, the author affiliations incorrectly listed âCandiolo Cancer Institute FPO-IRCCS, Candiolo (TO), Italyâ as âCandiolo Cancer Institute, Candiolo, Italy.â The change has been made to the HTML and PDF versions of the article
Fine-mapping analysis including over 254,000 East Asian and European descendants identifies 136 putative colorectal cancer susceptibility genes
Genome-wide association studies (GWAS) have identified more than 200 common genetic variants independently associated with colorectal cancer (CRC) risk, but the causal variants and target genes are mostly unknown. We sought to fine-map all known CRC risk loci using GWAS data from 100,204 cases and 154,587 controls of East Asian and European ancestry. Our stepwise conditional analyses revealed 238 independent association signals of CRC risk, each with a set of credible causal variants (CCVs), of which 28 signals had a single CCV. Our cis-eQTL/mQTL and colocalization analyses using colorectal tissue-specific transcriptome and methylome data separately from 1299 and 321 individuals, along with functional genomic investigation, uncovered 136 putative CRC susceptibility genes, including 56 genes not previously reported. Analyses of single-cell RNA-seq data from colorectal tissues revealed 17 putative CRC susceptibility genes with distinct expression patterns in specific cell types. Analyses of whole exome sequencing data provided additional support for several target genes identified in this study as CRC susceptibility genes. Enrichment analyses of the 136 genes uncover pathways not previously linked to CRC risk. Our study substantially expanded association signals for CRC and provided additional insight into the biological mechanisms underlying CRC development
IMPROVED FALLOWS IN KENYA: HISTORY, FARMER PRACTICE, AND IMPACTS
This case study explores the development, dissemination, adoption, and impact of improved tree
fallows in rural western Kenya. The processes of technology development and dissemination
throughout the region are described and analyzed. To analyze adoption and impact, the paper
applies a variety of different data collection methods as well as samples from both pilot areas
where researchers maintained a significant presence and non-pilot areas where farmers learned of
the technologies through other channels. Sample sizes for the quantitative analysis ranged from
almost 2,000 households for measuring the adoption process to just over 100 households for
measuring impact indicators. Qualitative methods included long-term case studies for 40
households and focus group discussions involving 16 different groups. The paper describes the
ways in which farmers used and modified improved fallow practices. Discussion also examines
the types of households using fallows and benefiting from their use.
Empirical results suggest that improved fallows almost always double on-farm maize yields. In
addition, the data indicates that poor households use improved fallows at much greater rate
(about 30 percent) than they do fertilizer (8 percent), though, on average, the size of fallow plots
remains small, at 440m2. As a result, despite these promising signs, the improved fallow systems
were not found to be linked to improved household level food security or poverty indicators
primarily, primarily because the size of the fields under the agroforestry systems was on average,
quite small
The adoption and dissemination of fodder shrubs in Central Kenya
Includes bibliographical referencesAvailable from British Library Document Supply Centre- DSC:6077. 203637(no 131) / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo
THE BLENDING OF PARTICIPATORY RESEARCH AND QUANTITATIVE METHODS: WEALTH STATUS, GENDER AND THE ADOPTION OF IMPROVED FALLOWS IN ZAMBIA
Although there is increasing emphasis on targeting of improved technology towards poor and female farmers, few adoption studies assess the uptake of new practices by these groups in a comprehensive manner. In this study, community members used the wealth ranking method to identify the different wealth groups in their communities, to determine each household's wealth status, and to assess the association of wealth and different types of households with the planting of improved tree fallows, a practice for improving crop yields. There were no significant differences between the proportions of women and men planting improved fallows nor were there differences between single women and female heads of households who were married. There was some evidence of association between planting improved fallows and wealth. That 22% of the 'poor' group and 16% of the 'very poor' group were planting them suggests that there are no barriers preventing low-income households from doing so. Moreover, the proportion of females, poor, and very poor people planting improved fallows varied considerably among villages, suggesting that opportunities exist for increasing their use of technology. Whereas the use of mineral fertilizer is strongly associated with high-income, male farmers, improved fallows appear to be a gender-neutral and wealth-neutral technology. Poor farmers appreciate improved fallows because they permit them to substitute small amounts of land and labour for cash, their most scarce resource. Finally, the high degree of consistency among different key informants in classifying households among wealth groups confirmed the effectiveness and accuracy of the wealth ranking exercise