On non-linear excitation of voids in dusty plasmas

The void, which is a dust-free region inside the dust cloud in the plasma, results from a balance of the electrostatic force and the ion drag force on a dust particulate. The ion drag force having numerous forms, some of which are based on models whereas others are driven from first principles. To explain the generation of voids, Avinash et al.[K. Avinash, A. Bhattacharjee, and S. Hu, AIP.CP649, III ICPDP, (2002)p121]proposed a time-dependent nonlinear model that describes the void as a result of an instability. We augment this model by incorporating the grain drift and by replacing the ion-drag force by that derived by Khrapak et al., in a spherical configuration. It has been revealed that the void formation is a threshold phenomenon, i.e., it depends on the grain size. Furthermore, the void possesses a sharp boundary beyond which the dust density goes down and may present a corrugated aspect. For higher values of the grain size, the use of both ion drag forces leads to voids of a same dimension, though for grains of small sizes the Avinash force drives voids of a higher dimension

Communicating Biotechnology: Relationships Between Tone, Issues, and Terminology in U.S. Print Media Coverage

As part of a nationwide study on the public acceptability of agricultural biotechnology, researchers performed a content analysis on two years of print news coverage of biotechnology (2000-2002). Qualitative analysis methods included examining text from selected national newspapers, regional newspapers, and trade publications for common issues, tone, and terminology. A team of three coders, trained to an acceptable level of agreement (Cohen’s K = .80), examined and coded the articles. The relationship between the tone of the article and the terminology used in reference to biotechnology (e.g., “genetically engineered,” “genetically modified,” or “biotechnology”) has practical applications for both public relations practitioners and communication researchers. “Biotechnology” was associated with the largest percentage of articles with positive tones. “Genetically modified” was associated with more neutral articles. “Genetically engineered” was the term of choice for authors of physical science articles, which were mostly positive. Understanding these relationships may help communication practitioners choose their terminology to achieve their communication goals, as well as opinion researchers, who, in developing survey instruments, may wish to choose a term that carries the least amount of bias

Improving cereal productivity and farmers’ income using a strategic application of fertilizers in West Africa

In the past two years, ICRISAT, in collaboration with other International Agricultural Research Centres, National Agricultural Research and Extension Systems, has been evaluating and promoting point or hill application of fertilizer along with “Warrantage” in three West African countries, namely, Burkina Faso, Mali and Niger. The hill application of fertilizers consists of applying small doses of fertilizer in the planting hills of millet and sorghum. The combination of strategic hill application of fertilizer with complementary institutional and market linkages, through an inventory credit system (known as “Warrantage”) offers a good opportunity to improve crop productivity and farmers’ incomes. Results from the two year on-farm trials showed that, on average, in all the three countries, grain yields of millet and sorghum were greater by 44 to 120% while incomes of farmers increased by 52 to 134% when using hill application of fertilizer than with the earlier recommended fertilizer broadcasting methods and farmers’ practice. Substantial net profits were obtained by farmers using “Warrantage”. Farmers’ access to credit and inputs was improved substantially through the “Warrantage” system. The technology has reached up to 12650 farm households in the three countries and efforts are in progress to further scale-up and out the technology to wider geographical area