504 research outputs found
Contribution à l'étude des pourritures des cabosses du cacaoyer en basse Côte d'Ivoire durant les années 1958 et 1959
Unravelling technology-acceptance factors influencing farmer use of banana tissue culture planting materials in Central Uganda
Effective management of plant health is fundamental for food and income security to meet the growing demands of local and global markets. This however requires farmers’ adequate access to quality planting materials under the prevailing contextual and psycho-social factors. This study, anchored in the Unified Theory of Acceptance and Use of Technologies, unravels technology-acceptance factors that influence farmers’ intentions to use banana tissue culture planting materials in the control of Banana Xanthomonas Wilt. Data were collected from 248 randomly sampled banana farmers using a structured questionnaire and analyzed using structural equation modelling to examine hypothesized paths in the uptake of banana tissue culture planting materials. Results show that farmer intentions to use tissue culture planting materials are dependent on two constructs: social influence and farmer innovativeness. However, social influence is the main predictor of intentions to use tissue culture planting materials. In particular, farmer innovativeness mediates facilitating conditions and social influence in predicting intentions to use tissue culture planting materials. Thus, this study reveals two factors that influence farmer intentions to use tissue culture planting materials: social influence and farmer innovativeness. The findings imply that social influence and farmer innovativeness are critical in disseminating novel agricultural technologies in Uganda and elsewhere
Characterization of a Thin Film Composite Membrane: Fluorinated Copolymer in a Carbon Nanotube Matrix
IDEX Health and Science has created a thin-film composite membrane consisting of a carbon nanotube matrix impregnated with a fluorinated copolymer called Teflon® AF 2400. This membrane is being studied for use in degassing chambers of analytical instruments such as a High Pressure Liquid Chromatography (HPLC) degassing modules. The level of impregnation of the Teflon® in the carbon matrix affects the diffusion properties which are crucial for the performance of the membrane. Scanning Electron Microscopy (SEM) characterization techniques were used to measure the outer Teflon® and the inner carbon matrix layer thickness. The outer Teflon® and inner carbon matrix layer thicknesses ranged from 1.92 to 28.17 microns and 5.07 to 41.70 microns, respectively. Energy Dispersive X-ray Spectrometry (EDS) was used to measure the Teflon® fluorine concentration gradient across the composite membrane. Mechanical tensile testing was also performed on each sample to compare the mechanical properties of the membrane to the initial design parameters. Ultimate Tensile Strength (UTS), Young’s Modulus (E), and Percent Elongation were collected for each membrane. IDEX Health and Science used the following processing parameters to create each membrane: (a) Concentration, (b) Density, (c) Time, and (d) Recoat. Statistical analysis indicated that time and recoat had the largest effect on maximum stress at maximum load. The results from SEM imaging, EDS scans, and tensile testing helped determine how well the Teflon® infiltrated the carbon matrix. The interactions between the four processing parameters provided IDEX Health and Science with information to determine the optimal set of processing parameters for generating the ideal membrane
Life tables for global surveillance of cancer survival (the CONCORD programme): data sources and methods
We set out to estimate net survival trends for 10 common cancers in 279 cancer registry populations in 67 countries around the world, as part of the CONCORD-2 study. Net survival can be interpreted as the proportion of cancer patients who survive up to a given time, after eliminating the impact of mortality from other causes (background mortality). Background mortality varies widely between populations and over time. It was therefore necessary to construct robust life tables that accurately reflected the background mortality in each of the registry populations. Life tables of all-cause mortality rates by single year of age and sex were constructed by calendar year for each population and, when possible, by racial or ethnic sub-groups. We used three different approaches, based on the type of mortality data available from each registry. With death and population counts, we adopted a flexible multivariable modelling approach. With unsmoothed mortality rates, we used the Ewbank relational method. Where no data were available from the registry or a national statistical office, we used the abridged UN Population Division life tables and interpolated these using the Elandt-Johnson method. We also investigated the impact of using state- and race-specific life tables versus national race-specific life tables on estimates of net survival from four adult cancers in the United States (US)
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