India is the second largest producer of wheat in the world, with production hovering around 68–75... more India is the second largest producer of wheat in the world, with production hovering around 68–75 million tons for past few years. The latest estimated demand for wheat production for the year 2020 is approximately 87.5 million tons, or about 13 million tons more than the record production of 75 million tons harvested in crop season 1999–2000. Since 2000, India has struggled to match that record production figure and thus faces a critical challenge in maintaining food security in the face of its growing population. The current major challenges facing future wheat production in India are increasing heat stress; dwindling water supplies for irrigation; a growing threat of new virulence of diseases such as wheat rusts (yellow, brown, and black) and leaf blight; continuous adoption of rice-wheat systems on around 11 million hectares; changes in urbanization patterns, and demand for better quality wheat. In addition, the threat posed by the new stem rust race Ug99 can not be underestimated. The wide gap (around 2.5 t/ha) between the potential and harvested yield in the eastern Gangetic Plains also cries out for solutions. Addressing issues related to different stresses will require harnessing genes discovered in landraces and wild relatives following conventional as well as non-conventional approaches. For effective technology delivery in areas that suffer from poor linkages with farmers, participatory research needs to be strengthened. The future germplasm requirements from a dependable collaborator such as CIMMYT are largely being dictated by the above factors.
Critical Reviews in Food Science and Nutrition, 2011
Flavonoids are a family of polyphenolic compounds which are widespread in nature (vegetables) and... more Flavonoids are a family of polyphenolic compounds which are widespread in nature (vegetables) and are consumed as part of the human diet in significant amounts. There are other types of polyphenols, including, for example, tannins and resveratrol. Flavonoids and related polyphenolic compounds have significant antiinflammatory activity, among others. This short review summarizes the current knowledge on the effects of flavonoids and related polyphenolic compounds on inflammation, with a focus on structural requirements, the mechanisms involved, and pharmacokinetic considerations. Different molecular (cyclooxygenase, lipoxygenase) and cellular targets (macrophages, lymphocytes, epithelial cells, endothelium) have been identified. In addition, many flavonoids display significant antioxidant/radical scavenging properties. There is substantial structural variation in these compounds, which is bound to have an impact on their biological profile, and specifically on their effects on inflammatory conditions. However, in general terms there is substantial consistency in the effects of these compounds despite considerable structural variations. The mechanisms have been studied mainly in myeloid cells, where the predominant effect is an inhibition of NF-κB signaling and the downregulation of the expression of proinflammatory markers. At present there is a gap in knowledge of in vitro and in vivo effects, although the pharmacokinetics of flavonoids has advanced considerably in the last decade. Many flavonoids have been studied for their intestinal antiinflammatory activity which is only logical, since the gastrointestinal tract is naturally exposed to them. However, their potential therapeutic application in inflammation is not restricted to this organ and extends to other sites and conditions, including arthritis, asthma, encephalomyelitis, and atherosclerosis, among others.
Sidewall roughness (SWR) of fluorinated polyether waveguides fabricated using reactive ion etchin... more Sidewall roughness (SWR) of fluorinated polyether waveguides fabricated using reactive ion etching in pure oxygen gas was directly measured using atomic force microscope (AFM). We confirmed that SWR is not the replicate of line edge roughness (LER) of the waveguides. We also confirmed the pressure dependence of SWR for shallow structures and discovered an additional etch depth dependence for deeper structures which counteracts the pressure dependence. Lower O2 pressure etching produces SWR which increases with depth while higher O2 pressure etching produces declining SWR with depth. The depth dependence at lower pressure is explained by the change in the arrival dynamics of etchant ions in a mechanism involving both shadowing and first order reemission effects.
The novel contribution of this paper is the application of natural fiber (Silk) as a braided slee... more The novel contribution of this paper is the application of natural fiber (Silk) as a braided sleeve for the PAM. A simple artificial muscle with internal core of silicon rubber netted by hand woven natural fiber (Silk) was fabricated. A suitable experiment was conducted to collect the displacement data which were produced by Silicon Pneumatic Artificial Muscle (SPAM) with various compressed air pressures. The advantages using Silk as braided sleeves are: it is naturally available with higher stiffness than that of steel and nylon. The movement of this actuator is soft which is similar to the human muscle; hence it is preferred for usage in bio medical engineering application and prosthetics devices.
India is the second largest producer of wheat in the world, with production hovering around 68–75... more India is the second largest producer of wheat in the world, with production hovering around 68–75 million tons for past few years. The latest estimated demand for wheat production for the year 2020 is approximately 87.5 million tons, or about 13 million tons more than the record production of 75 million tons harvested in crop season 1999–2000. Since 2000, India has struggled to match that record production figure and thus faces a critical challenge in maintaining food security in the face of its growing population. The current major challenges facing future wheat production in India are increasing heat stress; dwindling water supplies for irrigation; a growing threat of new virulence of diseases such as wheat rusts (yellow, brown, and black) and leaf blight; continuous adoption of rice-wheat systems on around 11 million hectares; changes in urbanization patterns, and demand for better quality wheat. In addition, the threat posed by the new stem rust race Ug99 can not be underestimated. The wide gap (around 2.5 t/ha) between the potential and harvested yield in the eastern Gangetic Plains also cries out for solutions. Addressing issues related to different stresses will require harnessing genes discovered in landraces and wild relatives following conventional as well as non-conventional approaches. For effective technology delivery in areas that suffer from poor linkages with farmers, participatory research needs to be strengthened. The future germplasm requirements from a dependable collaborator such as CIMMYT are largely being dictated by the above factors.
Critical Reviews in Food Science and Nutrition, 2011
Flavonoids are a family of polyphenolic compounds which are widespread in nature (vegetables) and... more Flavonoids are a family of polyphenolic compounds which are widespread in nature (vegetables) and are consumed as part of the human diet in significant amounts. There are other types of polyphenols, including, for example, tannins and resveratrol. Flavonoids and related polyphenolic compounds have significant antiinflammatory activity, among others. This short review summarizes the current knowledge on the effects of flavonoids and related polyphenolic compounds on inflammation, with a focus on structural requirements, the mechanisms involved, and pharmacokinetic considerations. Different molecular (cyclooxygenase, lipoxygenase) and cellular targets (macrophages, lymphocytes, epithelial cells, endothelium) have been identified. In addition, many flavonoids display significant antioxidant/radical scavenging properties. There is substantial structural variation in these compounds, which is bound to have an impact on their biological profile, and specifically on their effects on inflammatory conditions. However, in general terms there is substantial consistency in the effects of these compounds despite considerable structural variations. The mechanisms have been studied mainly in myeloid cells, where the predominant effect is an inhibition of NF-κB signaling and the downregulation of the expression of proinflammatory markers. At present there is a gap in knowledge of in vitro and in vivo effects, although the pharmacokinetics of flavonoids has advanced considerably in the last decade. Many flavonoids have been studied for their intestinal antiinflammatory activity which is only logical, since the gastrointestinal tract is naturally exposed to them. However, their potential therapeutic application in inflammation is not restricted to this organ and extends to other sites and conditions, including arthritis, asthma, encephalomyelitis, and atherosclerosis, among others.
Sidewall roughness (SWR) of fluorinated polyether waveguides fabricated using reactive ion etchin... more Sidewall roughness (SWR) of fluorinated polyether waveguides fabricated using reactive ion etching in pure oxygen gas was directly measured using atomic force microscope (AFM). We confirmed that SWR is not the replicate of line edge roughness (LER) of the waveguides. We also confirmed the pressure dependence of SWR for shallow structures and discovered an additional etch depth dependence for deeper structures which counteracts the pressure dependence. Lower O2 pressure etching produces SWR which increases with depth while higher O2 pressure etching produces declining SWR with depth. The depth dependence at lower pressure is explained by the change in the arrival dynamics of etchant ions in a mechanism involving both shadowing and first order reemission effects.
The novel contribution of this paper is the application of natural fiber (Silk) as a braided slee... more The novel contribution of this paper is the application of natural fiber (Silk) as a braided sleeve for the PAM. A simple artificial muscle with internal core of silicon rubber netted by hand woven natural fiber (Silk) was fabricated. A suitable experiment was conducted to collect the displacement data which were produced by Silicon Pneumatic Artificial Muscle (SPAM) with various compressed air pressures. The advantages using Silk as braided sleeves are: it is naturally available with higher stiffness than that of steel and nylon. The movement of this actuator is soft which is similar to the human muscle; hence it is preferred for usage in bio medical engineering application and prosthetics devices.
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Papers by Shankar Nagarajan