215 research outputs found

    FACTORS AFFECTING ADOPTION OF IMPROVED MAIZE SEEDS AND USE OF INORGANIC FERTILIZER FOR MAIZE PRODUCTION IN THE INTERMEDIATE AND LOWLAND ZONES OF TANZANIA

    Get PDF
    This paper examines factors influencing the adoption of improved maize seeds and the use of inorganic fertilizer for maize production by farmers in the intermediate and lowland zones of Tanzania. The results indicate that availability of extension services, on-farm field trials, variety characteristics and rainfall were the most important factors that influenced the extent of adopting improved maize seeds and the use of inorganic fertilizer for maize production. Farmers preferred those varieties which minimize field loss rather than maximizing yields. Future research and extension policies should emphasize farmer participation in the research process and on-farm trials for varietal evaluation and demonstration purposes.adoption, agroecological zones, improved maize seeds, new technology, Tanzania, Crop Production/Industries,

    Enteric physiology, neuropathology, and bowel function following colorectal resections in adults and children

    Get PDF
    Optimal functional outcomes following colorectal resections are important to people suffering from colorectal cancer or born with a colorectal disorder. In this thesis, we assessed long-term functional outcomes following colorectal surgery in adults and children, combined with studies of the physiological function and neural innervation of the bowel. In Part I, we presented fundamental studies regarding anorectal physiology, showing a newly investigated pathway between the anal canal and the rectum (the anorectal defecation reflex), which appears to play a role in defecation.In Part II, we discussed the presence of bowel function problems in the adults and children of the general population. We showed how bowel function could be measured from infancy till childhood using the newly developed Early Pediatric Defecation and Fecal Continence questionnaire. In Part III, we investigated the long-term functional outcomes following oncological colorectal resections in adults. We concluded that even though bowel function problems continue to exist years after surgery for colorectal cancer, most patients remain untreated. In Part IV, we evaluated the long-term functional outcomes following colorectal resections because of Hirschsprung’s disease in children. Surprisingly, in the long term, patients with Hirschsprung’s disease with a long aganglionic segment do not suffer from more fecal incontinence compared to patients with aganglionosis limited to the rectosigmoid.In Part V, we concluded that the remaining ganglionic colon of patients with Hirschsprung’s disease contains many neural deficiencies. For example, the colon shows a relative overabundance of nitrergic neurons and larger neurons, which correlates with severe postoperative constipation

    ADOPTION OF MAIZE AND WHEAT TECHNOLOGIES IN EASTERN AFRICA: A SYNTHESIS OF THE FINDINGS OF 22 CASE STUDIES

    Get PDF
    This paper synthesizes the findings of 22 micro-level studies on technology adoption carried out by the International Maize and Wheat Improvement Center (CIMMYT) with national agricultural research systems in Ethiopia, Kenya, Tanzania, and Uganda from 1996-1999. The authors found that technology adoption is taking place across Eastern Africa but considerable scope remains to improve the productivity of smallholder agriculture in higher potential regions with high levels of adoption. Extension was the variable most highly correlated with technology adoption, and extension services continue to play an important role in disseminating information on new varieties and how to manage them. Despite the usefulness of the micro-study results, especially for priority setting and impact assessment, future adoption studies can be improved by standardizing definitions across studies and using sampling techniques that allow results to be generalized across wider areas. Finally, the paper suggests that maize and wheat breeding research should be made more relevant to the preferences and circumstances of farmers, that the link between research and extension should be strengthened and include the private sector and non-governmental organizations, that policies should support the development and expansion of efficient markets for inputs and outputs, and that rural credit systems should be strengthened.Maize, Wheat, Innovation adoption, Technology transfer, Plant Breeding, Small farms, Case studies, Fertilizers, Private sector, Nongovernmental organizations, Research institutions, International organizations, Kenya, Tanzania, Uganda, Farm Management,

    Wheat Farmers' Seed Management and Varietal Adoption in Kenya

    Get PDF
    Wheat is the second most important crop in Kenya after maize and is becoming an important source of food both for humans and livestock. Despite increasing wheat production, only 50% of domestic consumption requirements are being met. While the National Plant Breeding Research Centre at the Kenya Agricultural Research Institute has released more than 100 wheat varieties since it began operations in 1927, adoption has been slow in spite of better performance of new varieties. This study examined factors that influence farmers' adoption of new varieties in the Narok, Nakuru, and Uasin Gishu Districts that account for 80% of Kenya's domestic wheat production. The study found that most farmers in these Districts neither knew nor grew new wheat varieties, reflecting lack of seed and knowledge of these new varieties. Wheat varieties were also often not adopted in agroecological zones for which they were targeted. This should be an issue of concern to wheat breeders since varieties are currently bred specifically for agroecological zones. The main sources of wheat seed (old and new) for both small-scale and large-scale farmers were other farmers. The adoption of new wheat varieties was significantly higher among large-scale farmers in the high potential zone in Uasin Gishu District than among small-scale farmers in the low potential zone in Nakuru and Narok Districts. The logit model showed that experience in wheat farming had a positive impact on adoption of new wheat varieties. These factors will need to be taken into account by researchers, extension specialists, and policy makers.Crop Production/Industries,

    Adoption of Improved Wheat Technologies by Small-Scale Farmers in Mbeya District, Southern Highlands, Tanzania

    Get PDF
    This study was conducted to gain an understanding of how small-scale farmers in Mbeya District have adopted improved wheat technologies promoted by the wheat research program at MARTI-Uyole. The specific objectives were to assess farmers’ wheat management practices, determine the technical and socioeconomic factors affecting the adoption of improved wheat technologies, and draw implications for research, extension, and policy. A purposive multistage sampling procedure was used to select 202 farmers, 160 from Tembela Division and 42 from Isangati Division, which are two important wheat-growing areas in Mbeya District. Primary data were collected using structured questionnaires and supplemented by secondary information obtained from MARTI-Uyole. Juhudi was the preferred improved wheat variety grown by adopters. For all farmers, the most important characteristics preferred in a variety were high yield, marketability, grain color, and early maturity. In 1997, about 74% of sample farmers adopted improved wheat varieties. The rate of adoption increased between 1989 and 1995 for a number of reasons, including provision of seed and fertilizer by Sasakawa Global-2000 (SG-2000), the collapse of the pyrethrum industry, and market liberalization. After 1995, adoption declined because SG-2000 was phased out and the varieties had succumbed to stem rust and foliar diseases. Tobit analysis showed that farm size, family size, and the use of hired labor were significant factors affecting the proportion of land allocated to improved wheat. Farm size, family size, hired labor, and credit all significantly affected the amount of fertilizer used. Additional improved varieties need to be developed, not only to replace the old varieties, but to give farmers a wider choice. Fertilizer recommendations need to be reviewed to take into consideration farmers’ circumstances such as cash availability and soil fertility. Extension services in the area should be increased and the link between extension workers and landholders strengthened to promote the adoption of improved wheat technologies. The formal credit market is only weakly involved in supplying credit to wheat farmers, but rising input prices, especially for fertilizer, make access to credit increasingly important for farmers. Policymakers and bankers should focus on providing loans to small-scale wheat farmers with high rates of loan recovery and low cost of credit. Farmers should also be encouraged to form their own savings and credit cooperatives at the village level. Policymakers should continue to encourage and support the private sector to invest in input acquisition and distribution so that inputs (especially seed and fertilizer) are available when farmers need them.Tanzania, wheats, varieties, innovation adoption, technology transfer, economic indicators, socioeconomic environment, plant breeding methods, research programs, crop management, fertilizer application, food production, small farms, highlands, Crop Production/Industries, E14, E30,

    Adoption of Maize Production Technologies in the Coastal Lowlands of Kenya

    Get PDF
    Maize is the major food crop grown in the coastal region of Kenya and constitutes a major component of the diet of the population in the region. However, average yields are far below the potential for the region and low production levels create serious food deficits. Over the years, new technologies have been introduced but adoption has remained low, especially for fertilizer. This paper examined current maize-farming practices and technological and socioeconomic factors that influenced adoption in the Kilifi and Kwale Districts of the Coast Province, that together account for half of maize production in the region. The study found low adoption levels for improved maize varieties and technology, especially fertilizer, among farmers in the area. Farmers cited poor availability of improved varieties, high cost, lack of knowledge, and unfavourable characteristics of improved varieties as reasons for non-adoption. The high price and poor availability of fertilizers, farmers’ inexperience with them, and their perception that soils were already fertile were among reasons given for low fertilizer use. The low levels of adoption of improved varieties indicate that they are not meeting farmers’ needs. The authors recommend that researchers communicate with and include farmers’ criteria when breeding varieties. In addition, alternative options should be extended to farmers who are not able to use inorganic fertilizers. Finally, given the major influence of the institutional environment found in the study, it is recommended that extension services be strengthened, especially where lack of knowledge was cited as a hindrance to adoption.Maize, Crops, Innovation adoption, Technology transfer, Food production, Production economics, Production factors, Plant breeding, Fertilizers, Yields, Kenya, Crop Production/Industries, E14, E16,

    Expanding the CRISPR toolbox in Culicine mosquitoes: in vitro validation of Pol III promoters

    Get PDF
    CRISPR–Cas9-based “gene drive” technologies have been proposed as a novel and effective means of controlling human diseases vectored by mosquitoes. However, more complex designs than those demonstrated to date—and an expanded molecular toolbox with which to build them—will be required to overcome the issues of resistance formation/evolution and drive spatial/temporal limitation. Foreseeing this need, we assessed the sgRNA transcriptional activities of 33 phylogenetically diverse insect Polymerase III promoters using three disease-relevant Culicine mosquito cell lines (Aedes aegypti, Aedes albopictus, and Culex quinquefasciatus). We show that U6 promoters work across species with a range of transcriptional activity levels and find 7SK promoters to be especially promising because of their broad phylogenetic activity. We further show that U6 promoters can be substantially truncated without affecting transcriptional levels. These results will be of great utility to researchers involved in developing the next generation of gene drives

    The Prevalence of Bowel and Bladder Function During Early Childhood:A Population-Based Study

    Get PDF
    Objectives: Our primary aim was to determine bowel and bladder function in children aged 1 month to 7 years in the general Dutch population. Second, we aimed to identify demographic factors associated with the presence of bowel and bladder dysfunction, and their coexistence. Methods: For this cross-sectional, population-based study, parents/caregivers of children aged from 1 month to 7 years were asked to complete the Early Pediatric Groningen Defecation and Fecal Continence questionnaire. Different parameters of bowel and bladder function were assessed using validated scoring systems such as the Rome IV criteria. Results: The mean age of the study population (N = 791) was 3.9 ± 2.2 years. The mean age at which parents/caregivers considered their child fully toilet-trained was 5.1 ± 1.5 years. Prevalence of fecal incontinence among toilet-trained children was 12%. Overall prevalence of constipation was 14%, with a constant probability and severity at all ages. We found significant associations between fecal incontinence and constipation [odds ratio (OR) = 3.88, 95% CI: 2.06-7.30], fecal incontinence and urinary incontinence (OR = 5.26, 95% CI: 2.78-9.98), and constipation and urinary incontinence (OR = 2.06, 95% CI: 1.24-3.42). Conclusions: Even though most children are fully toilet-trained at 5 years, fecal incontinence is common. Constipation appears to be common in infants, toddlers, and older children. Fecal incontinence and constipation frequently coexist and are often accompanied by urinary incontinence. Increased awareness of bowel and bladder dysfunction in infants, toddlers, and young children is required to prevent these problems from continuing at older ages.</p

    The Seed Industry for Dryland Crops in Eastern Kenya

    Get PDF
    The development and promotion of improved crop varieties as well as efficient seed production, distribution, and marketing systems have contributed significantly to increased agricultural production and food security in Kenya. However, these impacts have not been replicated in the semi-arid midlands due to climatic, soil, and institutional factors. Following the liberalization of agriculture in the late 1980s, there has been greater participation of the private sector, non-governmental organizations, and voluntary agencies in the area. This study examined the extent to which these developments affected farmers’ access to dryland crops. The study found that the low quantity of seed traded, high cost of production, and high seed supply prices constrained the development of local seed trade. It recommended developing and offering a range of varieties to farmers to increase demand, training to strengthen farmers’ capacity to manage seed on-farm, and reduction of high production and distribution costs through further research and institutional improvements. In addition, the “seed loans” model, which has been very effective in the area, should be strengthened.Agricultural situation, Seed industry, Seed production, Food security, Marketing, Production costs, Distribution costs, Private sector, Public sector, Farmers, Farming systems, Dry farming, Crop husbandry, Kenya, Crop Production/Industries, E16, F01,

    Enantiomerically pure β-phenylalanine analogues from α–β-phenylalanine mixtures in a single reactive extraction step

    Get PDF
    An efficient and selective method for the extraction of α-amino acids in preference over their β-isomers using PdCl2(PPh3)2 was discovered, which enables the separation of product mixtures obtained in the enantioselective enzymatic formation of β-amino acids.
    corecore