Is farmer-to-farmer extension effective? The impact of training on technology adoption and rice farming productivity in Tanzania

Agricultural training is a potentially effective method to diffuse relevant new technologies to increase productivity and alleviate rural poverty in Sub-Saharan Africa (SSA). However, since it is prohibitively expensive to provide direct training to all the farmers in SSA, it is critically important to examine the extent to which technologies taught to a small number of farmers disseminate to non-trained farmers. This paper investigates the technology dissemination pathways among smallholder rice producers within a rural irrigation scheme in Tanzania. As an innovative feature, we compare the performance of three categories of farmers: key farmers, who receive intensive pre-season training at a local training center; intermediate farmers, who are trained by the key farmers; and other ordinary farmers. By collecting and analyzing a unique five-year household-level panel data set, we estimate difference-in-differences models to assess how the gap in performance evolve as the technologies spill over from the trained farmers to the ordinary farmers. To disentangle the technology spillover process, we also examine the extent to which social and geographical network with the key and intermediate farmers influences the adoption of technologies by the ordinary farmers, by incorporating social relationship variables into spatial econometric models. We found that the ordinary farmers who were a relative or residential neighbor of a key or intermediate farmer were more likely to adopt new technologies than those who were not. As a result, while the key farmers’ technology adoption rates rose immediately after the training, those of the non-trained ordinary farmers caught up belatedly. As the technologies disseminated, the paddy yield of the key farmers increased from 3.1 to 5.3 tons per hectare, while the yield of the ordinary farmers increased from 2.6 to 3.7 tons per hectare. Our results suggest the effectiveness and practical potential of farmer-to-farmer extension programs for smallholders in SSA as a cost effective alternative to the conventional farmer training approach

Total and High Molecular Weight Adiponectin and Hepatocellular Carcinoma with HCV Infection

Adiponectin is shown to be inversely associated with development and progression of various cancers. We evaluated whether adiponectin level was associated with the prevalence and histological grade of hepatocellular carcinoma (HCC), and liver fibrosis in patients with hepatitis C virus (HCV) infection.A case-control study was conducted on 97 HCC patients (cases) and 97 patients (controls) matched for sex, Child-Pugh grade and platelet count in patients with HCV infection. The serum total and high molecular weight (HMW) adiponectin levels were measured by enzyme-linked immunosorbent assays and examined in their association with the prevalence of HCC. In addition, the relationship between these adiponectin levels and body mass index (BMI), progression of liver fibrosis, and histological grade of HCC was also evaluated. Liver fibrosis was assessed using the aspartate aminotransferase to platelet ratio index (APRI).There were no significant differences in the serum total and HMW adiponectin levels between cases and controls. Moreover, there were no inverse associations between serum total and HMW adiponectin levels and BMI in both cases and controls. On the other hand, serum total and HMW adiponectin levels are positively correlated with APRI in both cases (r = 0.491, P<0.001 and r = 0.485, P<0.001, respectively) and controls (r = 0.482, P<0.001 and r = 0.476, P<0.001, respectively). Interestingly, lower serum total (OR 11.76, 95% CI: 2.97–46.66 [P<0.001]) and HMW (OR 10.24, CI: 2.80–37.40 [P<0.001] adiponectin levels were independent risk factors of worse histological grade of HCC.Our results suggested that serum total and HMW adiponectin levels were predictors of liver fibrosis, but not prevalence of HCC in patients with HCV infection. Moreover, low these adiponectin levels were significantly associated with worse histological grades

Trends in hepatocellular carcinoma incident cases in Japan between 1996 and 2019

We examined the epidemiological trends, including the distribution of sex, age, and disease etiology, in HCC incident cases, over 24 years. Data of 20,547 HCC patients (1996–2019) were analyzed in this prospective study. We divided the study period into four 6-yearly quarters. HCC etiology was categorized as hepatitis B virus (HBV) infection, HBV + hepatitis C virus (HCV) infection, HCV infection, and both negative (non-BC). The incident cases of HCC per quarter of the study period were 4311 (21.0%), 5505 (26.8%), 5776 (28.1%), and 4955 (24.1%), sequentially. Overall, 14,020 (68.2%) patients were male. The number of HCC cases in patients < 60 years, 60–69 years, 70–79 years, and ≥ 80 years were 3711 (18.1%), 6652 (32.4%), 7448 (36.2%), and 2736 (13.3%), respectively. The average age of newly-diagnosed patients increased in each quarter. HCC was associated with HBV, HBV + HCV, and HCV infections and non-BC in 2997 (14.6%), 187 (0.9%), and 12,019 (58.5%), and 5344 (26.0%) cases, respectively. The number of HCV-associated cases decreased in each quarter, while that of non-BC-associated cases increased. HCC incident cases tend to increase in the elderly and in non-BC patients; in contrast, HCC incident cases due to HCV tend to decrease

Retrospective evaluation of whole exome and genome mutation calls in 746 cancer samples

Funder: NCI U24CA211006Abstract: The Cancer Genome Atlas (TCGA) and International Cancer Genome Consortium (ICGC) curated consensus somatic mutation calls using whole exome sequencing (WES) and whole genome sequencing (WGS), respectively. Here, as part of the ICGC/TCGA Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium, which aggregated whole genome sequencing data from 2,658 cancers across 38 tumour types, we compare WES and WGS side-by-side from 746 TCGA samples, finding that ~80% of mutations overlap in covered exonic regions. We estimate that low variant allele fraction (VAF < 15%) and clonal heterogeneity contribute up to 68% of private WGS mutations and 71% of private WES mutations. We observe that ~30% of private WGS mutations trace to mutations identified by a single variant caller in WES consensus efforts. WGS captures both ~50% more variation in exonic regions and un-observed mutations in loci with variable GC-content. Together, our analysis highlights technological divergences between two reproducible somatic variant detection efforts

Detection of heterogeneity of Cu, Zn-superoxide dismutase with monoclonal antibodies and the establishment of a highly sensitive fluorescence sandwich enzyme-linked immunosorbent assay

AbstractMurine monoclonal antibodies directed against a native form of Cu, Zn-superoxide dismutase (SOD) were produced by immunizing SOD purified from human erythrocytes. The monoclonal antibodies able to bind SOD were further screened for their ability to absorb SOD activity using antimouse 1gG conjugated iron beads as solid supports in magnetic separation. This new screening method revealed the heterogeneity of native SOD in the reactivity with the antibodies. One monoclonal antibody succesfully absorbed the entire activity of SOD detected by an inhibition assay of cypridina luciferin analog (MCLA)-dependent chemilluminescence induced by superoxide anion production, while others absorbed only a part of the SOD activity. The evidence that all of the latter antibodies failed to react with recombinant artificial SOD free of charge isomers suggested correlation of the heterogeneity with the presence of charge isomeric forms. The former antibody was further used to establish a fluorescence sandwich enzyme immunoassay, and this provided a very sensitive detection limit as low as 100 pg/ml

The Impact of Training on Technology Adoption and Productivity of Rice Farming in Tanzania: Is Farmer-to-Farmer Extension Effective?

How far can new technologies taught to a small number of selected farmers diffuse to other farmers in a village? In order to answer this question, this paper investigates the impact of JICA training on the adoption of rice cultivation technologies and productivity in an irrigation scheme in Tanzania. By using a unique five-year panel data set and spatial econometric techniques, we found that non-trained farmers learned new technologies from trained farmers through social networks and by observing their plots. As a result, the paddy yield of directly trained farmers increased from 3.1 tons per hectare in 2008 to 4.7 tons per hectare in 2012, while that of non-trained farmers increased from around 2.6 tons per hectare in 2008 to 3.7 tons per hectare in 2012

Study on Influence of Design and Operation Factors on Effluent ATU-BOD and N-BOD Concentrations from Sedimentation Tank in Rural Sewerage Facilities

生物膜方式と活性汚泥方式の農業集落排水施設処理水ATU‐BOD・N‐BODについて，その処理性能の評価を行いながら，設計・管理因子による影響と運転管理への反映手法を考察した．生物膜方式・活性汚泥方式における処理水BOD濃度へのATU‐BODとN‐BODの関与状況を定量的に把握することができた．また，生物膜方式・活性汚泥方式ともに沈殿槽流出水ATU‐BODには，槽内流入水ATU‐BOD濃度，槽内微生物濃度，槽内DO濃度が影響を与えており，処理水ATU‐BOD濃度は，これらの設計・管理因子を説明変数とするATU‐BOD収支式から推定できることが示唆された．BOD処理性能の確保・安定を図るためには，汚水中のATU‐BODの効率的な低減とともにN‐BODの発生制御を視野に入れた運転管理の重要性が示唆された

Study on Characteristics and Design, Operational Consideration on Nitrogen Removal in Rural Sewerage Facilities with Intermittent Aerobic Suspended-Growth Processes

連続流入間欠ばっ気活性汚泥方式の農業集落排水施設の窒素除去性能とその支配因子について，供用中の施設から得られた観測データを用いて考察した．窒素除去性能には，硝化・脱窒工程でのばっ気槽内の酸化還元電位が大きく関与しており，安定した除去性能を確保するためには，撹拌工程においては撹拌時間，ばっ気撹拌工程ではばっ気時間・ばっ気強度の適切な設定を通じて，ばっ気撹拌終了時は酸化状態に，また，撹拌終了時には確実に還元状態となるような運転・管理条件を保つことが重要であることが確認された．また，ばっ気槽内がばっ気撹拌終了時に好気状態（ORP値で100mV程度），撹拌終了時に嫌気状態（ORP値で－50～－200mVの範囲）が確保されている条件では，窒素除去は完全混合流による1次反応に従っているとともに，窒素除去率は，ばっ気槽内のMLSS，水温，ばっ気撹拌終了時DO濃度，水理学的滞留時間を説明変数とする双曲線関数式から推定できることが示唆された