High Dynamic-Range Radio-Interferometric Images at 327 MHz

Radio astronomical imaging using aperture synthesis telescopes requires deconvolution of the point spread function as well as calibration of the instrumental characteristics (primary beam) and foreground (ionospheric/atmospheric) effects. These effects vary in time and also across the field of view, resulting in directionally-dependent (DD), time-varying gains. The primary beam will deviate from the theoretical estimate in real cases at levels that will limit the dynamic range of images if left uncorrected. Ionospheric electron density variations cause time and position variable refraction of sources. At low frequencies and sufficiently high dynamic range this will also defocus the images producing error patterns that vary with position and also with frequency due to the chromatic aberration of synthesis telescopes. Superposition of such residual sidelobes can lead to spurious spectral signals. Field-based ionospheric calibration as well as "peeling" calibration of strong sources leads to images with higher dynamic range and lower spurious signals but will be limited by sensitivity on the necessary short-time scales. The results are improved images although some artifacts remain.Comment: to appear in Comptes Rendus Physique (2011

Effect of pyramiding Bt and CpTI genes on resistance of cotton to Helicoverpa armigera (Lepidoptera: Noctuidae) under laboratory and field conditions

Transgenic cotton (Gossypium hirsutum L.) varieties, adapted to China, have been bred that express two genes for resistance to insects. the Cry1Ac gene from Bacillus thuringiensis (Berliner) (Bt), and a trypsin inhibitor gene from cowpea (CpTI). Effectiveness of the double gene modification in conferring resistance to cotton bollworm, Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae), was studied in laboratory and field experiments. In each experiment, performance of Bt+CpTI cotton was compared with Bt cotton and to a conventional nontransgenic variety. Larval survival was lower on both types of transgenic variety, compared with the conventional cotton. Survival of first-, second-, and third-stage larvae was lower on Bt+CpTI cotton than on Bt cotton. Plant structures differed in level of resistance, and these differences were similar on Bt and Bt+CpTI cotton. Likewise, seasonal trends in level of resistance in different plant structures were similar in Bt and Bt+CpTI cotton. Both types of transgenic cotton interfered with development of sixth-stage larvae to adults, and no offspring was produced by H. armigera that fed on Bt or Bt+CpTI cotton from the sixth stage onward. First-, second-, and third-stage larvae spent significantly less time feeding on transgenic cotton than on conventional cotton, and the reduction in feeding time was significantly greater on Bt+CpTI cotton than on Bt cotton. Food conversion efficiency was lower on transgenic varieties than on conventional cotton, but there was no significant difference between Bt and Bt+CpTI cotton. In 3-yr field experimentation, bollworm densities were greatly suppressed on transgenic as compared with conventional cotton, but no significant differences between Bt and Bt+CpTI cotton were found. Overall, the results from laboratory work indicate that introduction of the CpTI gene in Bt cotton raises some components of resistance in cotton against H. armigera, but enhanced control of H. armigera under field conditions, due to expression of the CpTI gene, was not demonstrate

Effects of transgenic Cry1Ac + CpTI cotton on non-target mealybug pest Ferrisia virgata and its predator Cryptolaemus montrouzieri

Recently, several invasive mealybugs (Hemiptera: Pseudococcidae) have rapidly spread to Asia and have become a serious threat to the production of cotton including transgenic cotton. Thus far, studies have mainly focused on the effects of mealybugs on non-transgenic cotton, without fully considering their effects on transgenic cotton and trophic interactions. Therefore, investigating the potential effects of mealybugs on transgenic cotton and their key natural enemies is vitally important. A first study on the effects of transgenic cotton on a non-target mealybug, Ferrisia virgata (Cockerell) (Hemiptera: Pseudococcidae) was performed by comparing its development, survival and body weight on transgenic cotton leaves expressing Cry1Ac (Bt toxin) + CpTI (Cowpea Trypsin Inhibitor) with those on its near-isogenic non-transgenic line. Furthermore, the development, survival, body weight, fecundity, adult longevity and feeding preference of the mealybug predator Cryptolaemus montrouzieri Mulsant (Coleoptera: Coccinellidae) was assessed when fed F. virgata maintained on transgenic cotton. In order to investigate potential transfer of Cry1Ac and CpTI proteins via the food chain, protein levels in cotton leaves, mealybugs and ladybirds were quantified. Experimental results showed that F. virgata could infest this bivalent transgenic cotton. No significant differences were observed in the physiological parameters of the predator C. montrouzieri offered F. virgata reared on transgenic cotton or its near-isogenic line. Cry1Ac and CpTI proteins were detected in transgenic cotton leaves, but no detectable levels of both proteins were present in the mealybug or its predator when reared on transgenic cotton leaves. Our bioassays indicated that transgenic cotton poses a negligible risk to the predatory coccinellid C. montrouzieri via its prey, the mealybug F.virgata

The "Cotton Problem" in West and Central Africa: The Case for Domestic Reforms

Cotton subsidies have received considerable attention during the past four years, primarily triggered by the excessive government support received by the cotton sectors in the United States and the European Union. In response to that support, four cotton-producing countries in West and Central Africa -- Benin, Burkina Faso, Mali, and Chad -- have requested that the Doha round of negotiations on trade liberalization contain financial compensation for WCAcountries for as long as those Western subsidies remain in place. Brazil also brought a case to the World Trade Organization, claiming that the U.S. subsidies cause a reduction in the world prices of cotton, thus reducing the income of Brazilian cotton growers.Western cotton subsidies should be abolished, but not much attention has been paid to another, perhaps more important, issue. Many African cotton-producing countries, especially in WCA, must reform their cotton sector in order to allow a greater share of the world price to reach the growers and must foster a policy environment that is conducive to the promotion of new technologies. For the most part, the cotton sectors of the WCA countries are managed by government-owned parastatals. Competition by private entities is limited -- with deleterious consequences for the efficiency of the cotton sectors

PROMOTION STRATEGY OF CLOTHING BRAND COTTON BUTTON

Cotton Button, is a children\u27s clothing brand in South Tangerang has been established since 2014, which was born from the idea of a mother of two children who have experience in choosing fabrics on children\u27s clothing. Cotton Button focuses on children\u27s comfort and naturalness offered from organic cotton fabrics. Organic cotton fabric is a cloth derived from natural cotton seeds that are not modified, also planted without using pesticides both in plants and in their planting fields. Cotton Button\u27s has been promoting, but based on the data obtained, the promotions carried out have not been able to increase audience awareness of Cotton Button products. This caused a decline in sales in the city of Bandung. In connection with this phenomenon, the design of the Cotton Button clothing brand was designed. Keywords strategy, promotion, bran

A quantitative economic analysis of the impact of price reform and the elimination of subsidies on poverty among cotton producing households in rural Uganda : a thesis presented in partial fulfilment of the requirement for the degree of Masters in Applied Economics at Massey University, Palmerston North, New Zealand

The benefits of eliminating cotton subsidies for Africa have been studied in terms of a higher world price, greater market share and higher export earnings for Africa. These estimates have focused on macroeconomic gains. This research simulates the effect of increases in the price on incomes of cotton growing households in rural Uganda to assess the impact on poverty levels. The Foster-Greer-Thorbecke measure of poverty is used to analyse the effect price increase on poverty. Results from this research indicate that Ugandan cotton farmers are unlikely to benefit from the elimination of cotton subsidies without price reform within its domestic cotton market. It is estimated that price reform alone can decrease poverty by 5 percent among cotton growing households in the Northern and Eastern Regions of Uganda. The results of the simulations also indicate increasing the price of cotton reduces the income gap for those households that remain in poverty despite the price increase. Thus the price increase decreases the severity of poverty amongst cotton producing households in rural Uganda

Arkansas Cotton Variety Test 2016

The primary goal of the Arkansas Cotton Variety Test is to provide unbiased data regarding the agronomic performance of cotton varieties and advanced breeding lines in the major cotton-growing areas of Arkansas

Arkansas Cotton Variety Test 2003

The primary aim of the Arkansas Cotton Variety Test is to provide unbiased data regarding the agronomic performance of cotton varieties and advanced breeding lines in the major cotton-growing areas of Arkansas. This information helps seed dealers establish marketing strategies and assists producers in choosing varieties to plant. In this way, the annual test facilitates the inclusion of new, improved genetic material in Arkansas cotton production