Betel nut and tobacco chewing; potential risk factors of cancer of oesophagus in Assam, India

Cancer of the oesophagus is the most commonly diagnosed cancer in males in Assam, in north-eastern India, and ranks second for females. The chewing of betel nut, with or without tobacco and prepared in various ways, is a common practice in the region and a case–control study has been designed to study the pattern of risk associated with different ways of preparing and chewing the nuts. 358 newly diagnosed male patients and 144 female have been interviewed together with 2 control subjects for each case chosen at random from among the attendants who accompanied patients to hospital. There were significant trends in risk ratios associated with the frequency of chewing each day, with the duration of chewing in years and with the age at which the habit was started that were apparent for both males and females and which remained significant after allowance was made for other known risk factors, notably tobacco smoking and alcohol consumption. The adjusted ratios, in comparison with non-chewers, were 13.3 M and 5.7 F for chewing more than 20 times a day, 10.6 M and 7.2 F for persons who had chewed for more than 20 years and 10.3 M and 5.3 F for those who had started before the age of 20. Among the different combinations of ingredients that were chewed the adjusted odds ratios were highest for those who had been using fermented betel nut with any form of tobacco (7.1 M and 3.6 F). The risk associated with tobacco smoking and alcohol consumption, which are high in some parts of the world, were less in Assam than those associated with the chewing of betel nut. © 2001 Cancer Research Campaign http://www.bjcancer.co

Morphological characterization of sali rice accessions of North East India

Rice is a major cereal crop of Assam, North East India. The local rice accessions grown in this region possess unique traits of breeder’s choice i.e., tolerance to biotic and abiotic stresses. In the present investigation, 712 sali rice accessions of Assam were characterized using 20 qualitative and 13 quantitative traits. Among these, 19 qualitative traits showed distinct polymorphism except for the ligule colour. The maximum polymorphism was observed for apiculus colour followed by the colour of lemma palea and sterile lemma. The significant variation for the quantitative traits was recorded among the accessions. Lakhi Bilash and Borkamal were identified as the high yielding genotypes, which may be used further in breeding programmes. The cluster analysis using morphological traits based on the Euclidean distance matrix classified the accessions into the two distinct sub-groups. The high yielding accessions were grouped together in one cluster. A significant positive correlation was observed among the grain yield with the various panicle associated traits therefore, these may be used as selection criteria for development of high yielding rice varietiies

Morphological characterization of sali rice accessions of North East India

838-845Rice is a major cereal crop of Assam, North East India. The local rice accessions grown in this region possess unique traits of breeder’s choice i.e., tolerance to biotic and abiotic stresses. In the present investigation, 712 sali rice accessions of Assam were characterized using 20 qualitative and 13 quantitative traits. Among these, 19 qualitative traits showed distinct polymorphism except for the ligule colour. The maximum polymorphism was observed for apiculus colour followed by the colour of lemma palea and sterile lemma. The significant variation for the quantitative traits was recorded among the accessions. Lakhi Bilash and Borkamal were identified as the high yielding genotypes, which may be used further in breeding programmes. The cluster analysis using morphological traits based on the Euclidean distance matrix classified the accessions into the two distinct sub-groups. The high yielding accessions were grouped together in one cluster. A significant positive correlation was observed among the grain yield with the various panicle associated traits therefore, these may be used as selection criteria for development of high yielding rice varietiies

Short and Long-Term Sensitivity of Lab-Scale Thermocline Based Thermal Storage to Flow Disturbances

Molten-salt thermocline-based systems are a low-cost option for single-tank thermal energy storage in concentrated solar power plants. Due to the high variability in solar energy availability, these energy storage devices are subject to transient heat loads during charging that can affect the storage efficiency. Numerical simulations were conducted to analyze the stability characteristics of a lab-scale thermocline tank subject to a flow disturbance during charging under different operating temperatures. The charging process was first simulated at a constant Reynolds number for three different Atwood numbers; a stably stratified fluid layer develops inside the storage tank in all cases. A flow disturbance was then introduced at the inlet of the stratified thermocline tank by inserting colder fluid for a short period of time. The disturbance interacts with the thermocline and causes oscillations and mixing. The thermocline oscillations are under-damped and lead to an increase in thermocline region thickness. The transient behavior of the thermocline and the decay rate in its oscillations were analyzed; the damping time depends on the Atwood number. The persistence of flow disturbance effects during long-term cyclical operation was also investigated. Several charge/discharge cycles were simulated at constant Reynolds number to obtain a time-periodic thermal response for each Atwood number. The characteristic flow disturbance was introduced at the inlet during a single charging process, and the thermocline region was observed during several subsequent charge/discharge cycles to assess the long-term temporal attenuation of the disturbance. The thermocline almost fully recovers to the time-periodic behavior after a single cycle