Introduction: In 2016, China became the largest market for slim cigarettes in the world, selling 68.945 billion sticks. The purpose of this study is to examine the impact of China’s 2015 tobacco taxation policy on sl...Introduction: In 2016, China became the largest market for slim cigarettes in the world, selling 68.945 billion sticks. The purpose of this study is to examine the impact of China’s 2015 tobacco taxation policy on slim cigarette consumption and the product’s market trends. Methods: Monthly data on the market share of slim cigarettes and their average price between January 2014 and June 2017 were used to show tobacco market trends and to estimate the impact of the 2015 tobacco tax increase on tobacco consumption. Segmented regression analysis was used to estimate the immediate effect of the 2015 tax policy and the time trends in consumption due to the policy change. Findings: After the tobacco tax increase was announced in May 2015, the market share of slim cigarettes initially decreased by 0.2117 (p = 0.067). However, by the third month after the policy change, consumption began to increase, and the market share of slim cigarettes was 1.6 times the normal increase over time. Slim cigarettes gained a 2.02% additional share by the second quarter of 2017 (from 2.58% to 4.60%), controlling for the price difference between slim cigarettes and regular cigarettes. The coefficient of the share and the price ratio (slim cigarettes/regular cigarettes) was ?0.7536 (p = 0.0044), suggesting that slim cigarettes are a substitute for regular cigarettes. Estimates also show that after the tax increase was implemented, consumption of slim cigarettes increased almost three times the normal consumption rate (0.0069 versus 0.0024). Conclusion: The slim cigarette industry in China has grown rapidly in recent years. The 2015 tax increase has had only minimal or short-term impact on reducing the growing popularity of slim cigarettes. Since slim cigarettes are a substitute for regular cigarettes, more empirical research is urgently needed to study the health impacts of slim cigarette use and the impact of tobacco control policies on slim cigarette consumption.展开更多
Rare genetic variants are abundant in genomes but less tractable in genome-wide association study. Here we exploit a strategy of rare variation mapping to discover a gene essential for tendril development in cucumber ...Rare genetic variants are abundant in genomes but less tractable in genome-wide association study. Here we exploit a strategy of rare variation mapping to discover a gene essential for tendril development in cucumber （Cucumis sativus L.）. In a collection of 〉3000 lines, we discovered a unique tendril-less line that forms branches instead of tendrils and, therefore, loses its climbing ability. We hypothesized that this unusual phenotype was caused by a rare variation and subsequently identified the causative single nucleotide poly- morphism. The affected gene TEN encodes a TCP transcription factor conserved within the cucurbits and is expressed specifically in tendrils, representing a new organ identity gene. The variation occurs within a pro- tein motif unique to the cucurbits and impairs its function as a transcriptional activator. Analyses of transcrip- tomes from near-isogenic lines identified downstream genes required for the tendril＇s capability to sense and climb a support. This study provides an example to explore rare functional variants in plant genomes.展开更多
文摘Introduction: In 2016, China became the largest market for slim cigarettes in the world, selling 68.945 billion sticks. The purpose of this study is to examine the impact of China’s 2015 tobacco taxation policy on slim cigarette consumption and the product’s market trends. Methods: Monthly data on the market share of slim cigarettes and their average price between January 2014 and June 2017 were used to show tobacco market trends and to estimate the impact of the 2015 tobacco tax increase on tobacco consumption. Segmented regression analysis was used to estimate the immediate effect of the 2015 tax policy and the time trends in consumption due to the policy change. Findings: After the tobacco tax increase was announced in May 2015, the market share of slim cigarettes initially decreased by 0.2117 (p = 0.067). However, by the third month after the policy change, consumption began to increase, and the market share of slim cigarettes was 1.6 times the normal increase over time. Slim cigarettes gained a 2.02% additional share by the second quarter of 2017 (from 2.58% to 4.60%), controlling for the price difference between slim cigarettes and regular cigarettes. The coefficient of the share and the price ratio (slim cigarettes/regular cigarettes) was ?0.7536 (p = 0.0044), suggesting that slim cigarettes are a substitute for regular cigarettes. Estimates also show that after the tax increase was implemented, consumption of slim cigarettes increased almost three times the normal consumption rate (0.0069 versus 0.0024). Conclusion: The slim cigarette industry in China has grown rapidly in recent years. The 2015 tax increase has had only minimal or short-term impact on reducing the growing popularity of slim cigarettes. Since slim cigarettes are a substitute for regular cigarettes, more empirical research is urgently needed to study the health impacts of slim cigarette use and the impact of tobacco control policies on slim cigarette consumption.
文摘Rare genetic variants are abundant in genomes but less tractable in genome-wide association study. Here we exploit a strategy of rare variation mapping to discover a gene essential for tendril development in cucumber （Cucumis sativus L.）. In a collection of 〉3000 lines, we discovered a unique tendril-less line that forms branches instead of tendrils and, therefore, loses its climbing ability. We hypothesized that this unusual phenotype was caused by a rare variation and subsequently identified the causative single nucleotide poly- morphism. The affected gene TEN encodes a TCP transcription factor conserved within the cucurbits and is expressed specifically in tendrils, representing a new organ identity gene. The variation occurs within a pro- tein motif unique to the cucurbits and impairs its function as a transcriptional activator. Analyses of transcrip- tomes from near-isogenic lines identified downstream genes required for the tendril＇s capability to sense and climb a support. This study provides an example to explore rare functional variants in plant genomes.
