493 research outputs found
Re-thinking Labour Migration in Relation to Livelihood Diversity in African Rural Area: A Case Study in Southern Province, Zambia
アフリカ農村部では農業が基盤ではあるが、市場経済の影響やリスクへの対応として農民の生業は多様化してきている。中でも出稼ぎ労働は農村経済を補填する役割を担うものとして注目されてきた。本稿の目的はザンビア農村部において、生業多様化の実態やリスクへの対応を明らかにし、そして特に出稼ぎ労働が持つ役割や影響を農村内の多生業との関わりから明らかにすることにある。 調査の結果、村内雇用労働や農業・農外賃労働、干ばつ時の対応策など様々な生計手段が観察された。しかし、各種の生業へのアクセスは一様ではなく、各世帯の生計戦略の幅に差異が生まれていることも明らかとなった。 これに対し調査地からの出稼ぎ労働は、低コストで容易に行えるため、農村内の生計戦略を代替するものとして農村社会と経済に組み込まれていた。これらが実現した要因として、近隣の都市における非熟練労働の需要増加と、社会的ネットワークによる初期費用の削減などの要因が挙げられる。 調査地における出稼ぎ労働は、干ばつなどの困窮時に容易に行える手段として重要な役割を担っている。しかし、その必要性や重要性は世帯によって異なり、それらは農村内の計戦略へのアクセスと関連しているといえる。This paper attempts to 1) describe diversification of economic activities in African rural area, 2) trace and describe labour migration, and 3) analyse the relationship between labour migration and diversified activities in rural society. In most rural areas of Africa, agriculture remains the main livelihood. However, agricultural production is often supplemented and even sustained by other economic activities in order to cope with variable environmental conditions, and social and economic changes. Labour migration has been considered as one of essential activities to supplement rural society, but we do not know much about the relation between labour migration and other strategies taken inside of the village. This paper has examined the situation of livelihood diversification and its relationship with labour migration in Zambia. As a result, there are employments, agricultural and non-agricultural wage labour and the coping strategies for drought. But practice of these strategies would be constrained by primary cost, social networks and assets. Access to these strategies was not in uniform. There are differences of livelihood strategies by households. In regard to labour migration, people can easily migrate without obstacles, thus it has been connected to rural society and economy as an alternative strategy. This character of labour migration was supported by increasing labour demand in neighbouring towns and social network. Labour migration had an essential role for compensating rural economy in case of distress, however importance and need for it would differ from households, and it had a relation with access to other livelihood strategies practicing inside of the village
Development of Fishing Practices within Commercial Fisheries in Lake Kariba, Southern Africa
Freshwater fisheries are an essential component of African fisheries, providing one-third of the total catch. This study focuses on the fishing of a small clupeid, Limnothrissa miodon, locally called kapenta, in Lake Kariba. Lake Kariba is shared by Zimbabwe and Zambia, and this study provides a chronology of the commercial kapenta fishing practices used in both countries. It examines how the current fishing methods have become popular among both white and black operators, from environmental and social perspectives. Unlike traditional and artisanal inland fisheries, which have a variety of fishing methods, only one fishing practice is employed in Lake Kariba. This is an artefact of the environmental characteristics of the man-made lake, political situations (settler colonialism and historical inequality between white and black populations), and socialist policies adopted by the Zimbabwean government. A modern fishing method invented by the white settlers has been widely accepted by the new black entrants to fishing and has spread throughout the lake
Functional Analysis of a Juvenile Hormone Inducible Transcription Factor, Krüppel homolog 1, in the Bean Bug, Riptortus pedestris
Juvenile hormone (JH) has two major functions in insects, i.e., suppression of metamorphosis in the larval or nymphal stage and promotion of reproduction in the adult stage. Krüppel homolog 1 (Kr-h1), a C2H2 zinc-finger type transcription factor, is reported to act downstream of the JH receptor complex. In the present study, the function of Kr-h1 was examined in adults and nymphs of Riptortus pedestris by RNA interference (RNAi). After injection of adults with dsRNA of Kr-h1, the expression level of Kr-h1 was significantly decreased in the abdomen. Kr-h1 dsRNA-injection resulted in a lower proportion of individuals with developed ovaries, but the difference was not statistically significant. The transcript levels of cyanoprotein-α and vitellogenin-1, which are JH-inducible genes encoding yolk proteins, were not affected in the abdomen by Kr-h1 knockdown. Kr-h1 dsRNA-injection was effective for suppression of Kr-h1 expression in nymphs. Some Kr-h1 dsRNA-injected fifth (final) instar nymphs had morphological defects in the wing bud. Moreover, they had several adult morphological features, including ocelli in the head, connexivum in the abdomen, coloring of the dorsal abdomen, and genitals. The nymphs possessing adult features did not emerge as adults during 1 month. These results demonstrated that Kr-h1 is necessary for maintaining nymphal characters in R. pedestris. The function of Kr-h1 in ovarian development remains unclear in R. pedestris
Production of overdense plasmas by launching 2,45 GHz electron cyclotron waves in a helical device
For production of low temperature plasmas with low collisionality, 2.45GHz
microwave power up to 20kW is injected perpendicularly to the toroidal field at
very low toroidal field BtComment: 12th International Congress on Plasma Physics, 25-29 October 2004,
Nice (France
Maternal multivitamin intake and orofacial clefts in offspring: Japan Environment and Children's Study (JECS) cohort study
Objectives: Orofacial clefts are common birth defects with a lack of strong evidence regarding their association with maternal nutrition. We aimed to determine whether a relationship exists between maternal nutrient or multivitamin intake and orofacial clefts. Design: This is a prospective, population-based nationwide cohort study. Setting: The study was conducted in 15 regional centres, consisting of local administrative units and study areas. Participants: A total of 98 787 eligible mother–child pairs of the Japan Environment and Children’s Study were included. Intervention: Exposures were maternal nutrition and the use of supplemental multivitamins in mothers. Primary and secondary outcome measures: Outcomes were the occurrence of any orofacial cleft at birth. Multinomial logistic regression analyses were used to evaluate the association between maternal multivitamin intake and the incidence of orofacial clefts. Results: Of the 98 787 children, 69 (0.07%) were diagnosed with cleft lip alone, 113 (0.11%) were diagnosed with cleft lip and palate, and 52 (0.05%) were diagnosed with cleft palate within 1 month after birth. Regarding the total orofacial cleft outcome, statistically significant point estimates of relative risk ratios (RR) were determined for multivitamin intake before pregnancy (RR=1.71; 95% CI 1.06 to 2.77) and during the first trimester (RR=2.00; 95% CI 1.18 to 3.37), but the association was not significant for multivitamin intake after the first trimester (RR=1.34; 95% CI 0.59 to 3.01). Maternal micronutrient intake via food was not associated with the incidence of orofacial clefts in offspring. Conclusions: Intake of multivitamin supplements shortly before conception or during the first trimester of pregnancy was found to be associated with an increased incidence of orofacial clefts at birth. Pregnant women and those intending to become pregnant should be advised of the potential risks of multivitamin supplementation
NFYA promotes the anti-tumor effects of gluconeogenesis in hepatocellular carcinoma through the regulation of PCK1 expression
Reprogramming of glucose metabolism occurs in many human tumor types, and one of these, gluconeogenesis, is known to exhibit anti-tumor effects in hepatocellular carcinoma (HCC). The transcription factor NFYA regulates gluconeogenesis in the normal liver tissue, but the function of the NFYA-gluconeogenesis axis in cancer and the functional differences of NFYA splicing variants in the regulation of gluconeogenesis is still unclear. Here, we demonstrate that NFYAv2, the short-form variant, upregulates the transcription of a gluconeogenic enzyme PCK1. We further reveal that its regulation induces high ROS levels and energy crisis in HCC and promotes cell death. These indicate that the NFYAv2-gluconeogenesis axis has enhanced anti-tumor effects in HCC, suggesting that the axis may be a potential therapeutic target for HCC. Furthermore, Nfyav1-deficient mice, spontaneously overexpressing Nfyav2, had no increasing gluconeogenesis in the liver. Taken together, our results reveal NFYAv2-gluconeogenesis axis has anti-tumor effects and the potential for NFYAv2 to be a safer therapeutic target for HCC
Comparison of Database Search Methods for the Detection of Legionella pneumophila in Water Samples Using Metagenomic Analysis
Metagenomic analysis has become a powerful tool to analyze bacterial communities in environmental samples. However, the detection of a specific bacterial species using metagenomic analysis remains difficult due to false positive detections of sequences shared between different bacterial species. In this study, 16S rRNA amplicon and shotgun metagenomic analyses were conducted on samples collected along a stream and ponds in the campus of Hokkaido University. We compared different database search methods for bacterial detection by focusing on Legionella pneumophila. In this study, we used L. pneumophila-specific nested PCR as a gold standard to evaluate the results of the metagenomic analysis. Comparison with the results from L. pneumophila-specific nested PCR indicated that a blastn search of shotgun reads against the NCBI-NT database led to false positive results and had problems with specificity. We also found that a blastn search of shotgun reads against a database of the catalase-peroxidase (katB) gene detected L. pneumophila with the highest area under the receiver operating characteristic curve among the tested search methods; indicating that a blastn search against the katB gene database had better diagnostic ability than searches against other databases. Our results suggest that sequence searches targeting long genes specifically associated with the bacterial species of interest is a prerequisite to detecting the bacterial species in environmental samples using metagenomic analyses
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