Observation of Period-Doubling Bloch Oscillations.

Bloch oscillations refer to the periodic oscillation of a wave packet in a lattice under a constant force. Typically, the oscillation has a fundamental period that corresponds to the wave packet traversing the first Brillouin zone once. Here, we demonstrate, both theoretically and experimentally, the optical Bloch oscillations where the wave packet must traverse the first Brillouin zone twice to complete a full cycle, resulting in a period of oscillation that is 2 times longer than that of usual Bloch oscillations. The unusual Bloch oscillations arise due to the band crossing of valley-Hall topological edge states at the Brillouin boundary for zigzag domain walls between two staggered honeycomb lattices with inverted on-site energy detuning, which are protected by the glide-reflection symmetry of the underlying structures. Our work sheds light on the direct detection of band crossings resulting from intrinsic symmetries that extend beyond the fundamental translational symmetry in topological systems.

The Association Between the License Fee Increase and the Density of Tobacco Retailers in California-A Segmented Interrupted Time-Series Analysis by Income and Race/Ethnicity.

INTRODUCTION: On May 9, 2016, the State of California passed a law to increase the licensing fee for tobacco retailers from a one-time-only fee of $100 to an annual fee of $265, effective on June 9, 2016. This study investigates the association between this fee increase and retailer densities by neighborhood income and race/ethnicity characteristics. METHODS: We obtained quarterly data on the number of active tobacco retailer licenses from 2011 to 2020 in every zip code in California from the California Department of Tax and Fee Administration. These data were then linked to zip code-level income, race/ethnicity, and population measures. We used a single-group segmented interrupted time-series analysis to assess the association between the increase in licensing fees and retailer densities by neighborhood income and race/ethnicity. RESULTS: After the implementation of the annual licensing fees, the retailer density decreased both immediately and gradually. Specifically, the retailer density dropped by 0.47 in the first quarter following the intervention. Compared to the pre-intervention time trend, the retailer density decreased quarterly by 0.05. Furthermore, the impacts of increasing licensing fees were more pronounced in low-income and the majority Black zip codes. CONCLUSIONS: Given that higher smoking prevalence is associated with greater tobacco outlet density, the licensing fee increase could be an effective policy tool to reduce tobacco use among economically disadvantaged and minority Black communities, thereby addressing tobacco-use disparities. IMPLICATIONS: This study used the single-group segmented interrupted time-series analysis to assess the association between the licensing fee increase and tobacco retailer densities by neighborhood income and race/ethnicity. We found that this licensing fee increase was associated with reduced retailer densities and the total number of active retailers right after the implementation. We further found that the annual licensing fee policy had a continuous effect in reducing tobacco retailer densities in all zip codes. The impacts of increasing licensing fees were more pronounced in low-income and majority of Black zip codes.

Evolutionary origin and establishment of a dioecious diploid-tetraploid complex.

Polyploids recurrently emerge in angiosperms, but most polyploids are likely to go extinct before establishment due to minority cytotype exclusion, which may be specifically a constraint for dioecious plants. Here we test the hypothesis that a stable sex-determination system and spatial/ecological isolation facilitate the establishment of dioecious polyploids. We determined the ploidy levels of 351 individuals from 28 populations of the dioecious species Salix polyclona, and resequenced 190 individuals of S. polyclona and related taxa for genomic diversity analyses. The ploidy survey revealed a frequency 52% of tetraploids in S. polyclona, and genomic k-mer spectra analyses suggested an autopolyploid origin for them. Comparisons of diploid male and female genomes identified a female heterogametic sex-determining factor on chromosome 15, which probably also acts in the dioecious tetraploids. Phylogenetic analyses revealed two diploid clades and a separate clade/grade of tetraploids with a distinct geographic distribution confined to western and central China, where complex mountain systems create higher levels of environmental heterogeneity. Fossil-calibrated phylogenies showed that the polyploids emerged during 7.6-2.3 million years ago, and population demographic histories largely matched the geological and climatic history of the region. Our results suggest that inheritance of the sex-determining system from the diploid progenitor as intrinsic factor and spatial isolation as extrinsic factor may have facilitated the preservation and establishment of polyploid dioecious populations.

Trends in Individualized Affordability of Factory-Made Cigarettes: Findings of the 2008-2020 International Tobacco Control Netherlands Surveys.

INTRODUCTION: Cigarette affordability, the price of tobacco relative to consumer income, is a key determinant of tobacco consumption. AIMS AND METHODS: This study examined trends over 12 years in individualized factory-made cigarette affordability in the Netherlands, and whether these trends differed by sex, age, and education. Data from 10 waves (2008-2020) of the International Tobacco Control Netherlands Surveys were used to estimate individualized affordability, measured as the percentage of income required to buy 100 cigarette packs (Relative Income Price [RIP]), using self-reported prices and income. The higher the RIP, the less affordable cigarettes are. Generalized estimating equation regression models assessed trends in individualized affordability over time and by sex, age, and education. RESULTS: Affordability decreased significantly between 2008 and 2020, with RIP increasing from 1.89% (2008) to 2.64% (2020) (p ≤ .001), except for 2008-2010, no significant year-on-year changes in affordability were found. Lower affordability was found among subgroups who have a lower income level: Females (vs. males), 18-24 and 25-39-year-olds (vs. 55 years and over) and low or moderate-educated individuals (vs. highly educated). Interactions between wave and education (p = .007) were found, but not with sex (p = .653) or age (p = .295). A decreasing linear trend in affordability was found for moderately (p = .041) and high-educated (p = .025), but not for low-educated individuals (p = .149). CONCLUSIONS: Cigarettes in the Netherlands have become less affordable between 2008 and 2020, yet this was mostly because of the decrease in affordability between 2008 and 2010. There is a need for more significant increases in tax to further decrease affordability. IMPLICATIONS: Our findings suggest that cigarettes have become less affordable in the Netherlands between 2008 and 2020. But, this appears to be the result of a steep decrease in affordability between 2008 and 2010. Affordability was lower among groups who have on average lower incomes (females, young adults, and low- and moderate-educated individuals), and differences in trends across education levels could be explained by per capita income changes. Our individualized measure indicated lower affordability than published aggregate affordability estimations. Future tax increases should be large enough to result in a lower affordability.

Tax incidence of electronic nicotine delivery systems (ENDS) in the USA.

BACKGROUND: A growing number of states or jurisdictions in the USA have imposed excise taxes on electronic nicotine delivery systems (ENDS). However, there is no consensus on how best to tax ENDS. OBJECTIVES: We specifically compare the tax incidence or burden for ENDS and cigarettes and analyse how ENDS tax incidence is associated with the choices of tax bases and rates. METHODS: We calculate ENDS excise tax incidence as the percentage of retail prices for each state or jurisdiction. Next, we use ordinary least squares to evaluate how tax incidence is associated with the choices of tax bases (eg, a specific tax base vs a value or ad valorem tax base) and rates and how these associations are moderated by product types. RESULTS: ENDS and cigarette tax incidence is similar at the state level. Nonetheless, when federal cigarette taxes are considered, the cigarette tax incidence is higher than the tax incidence on closed-system ENDS. The proportion of states that impose value taxes is higher for open systems (65.4%) than for closed systems (46.2%). A value tax base is associated with a 7 percentage point lower tax incidence compared with a specific tax base. Product type further moderates the association between tax base and incidence. CONCLUSION: Tax incidence can be used to measure the strength of ENDS tax policies and how they are compared with cigarette taxes. Policymakers who aim to prevent youth from using ENDS may consider a value tax base to raise the tax incidence of closed systems-the product type preferred by young people.

How cigarette excise tax pass-through to prices responds to the uptake and evolution of e-cigarettes (ECs).

BACKGROUND: How excise taxes are passed through to prices determines whether tax policies will be effective in changing smoking behaviours. Though previous literature has documented that cigarette taxes are overly shifted to prices, there is limited evidence on how cigarette tax pass-through to prices is affected by the uptake and evolution of e-cigarettes (ECs) in the US market. OBJECTIVE: This study investigates how cigarette excise tax pass-through rate varied by price levels (the 25th, 50th, and 75th percentile prices) and the uptake and evolution of ECs. METHODS: Tax pass-through rates were assessed using ordinary least squares regressions while controlling for state, year and month fixed effects. Different trends were then tested for the pre-EC uptake era (2006-2011), EC uptake era (2012-2016) and the evolution of nicotine salt-based ECs era (2017 and later). FINDINGS: Cigarette excise taxes were fully shifted to the 25th and 50th percentile prices and overly shifted to the 75th percentile prices at a 1:1.1 rate. While cigarette excise taxes had a continuous impact on raising prices, the tax pass-through rates were lower for lower priced cigarettes, and states imposed lower taxes. CONCLUSIONS: Continuing to raise cigarette taxes may be needed to create financial incentives to encourage people who smoke to switch to ECs. In addition, continuing to raise cigarette taxes and additional pricing policies such as price promotion restrictions are needed to increase retail prices and reduce price minimisation opportunities.

What types of e-liquid products were more likely to offer price promotions?

INTRODUCTION: The present study empirically examined the association between price discounts and product attributes of e-liquids sold by online retailers. METHODS: We analysed 14 000 e-liquid products from five major online e-cigarette retailers between April and May 2021 to determine the association between price discounts and product attributes such as nicotine level and form, flavour and vegetable glycerine/propylene glycol ratio. A fixed-effects model was used in the analysis and discounts were calculated in US cents/mL of e-liquid volume. RESULTS: Out of 14 407 e-liquid products, 92.5% were offered at a discounted price. On average, the price discount for the 13 324 products that had discounts was 16.84 cents/mL across the five stores. Among the three forms of nicotine (salt, freebase and nicotine free), salt e-liquids had the highest average price discount. CONCLUSION: Our findings suggest that e-liquids with salt nicotine have a higher average price discount when sold online, which may influence consumer purchasing behaviour. Further research is needed to assess the potential impact of these discounts on youth and adult tobacco use. Policymakers may consider implementing measures to limit online price discounts for e-liquids as a means of reducing sales among young people.

Tobacco purchasing in Australia during regular tax increases: findings from the International Tobacco Control Policy Evaluation Project.

OBJECTIVE: We examined Australian tobacco purchasing trends, the average self-reported price paid within each purchase type and the association between type of tobacco product purchased and participant characteristics, including quit intentions, between 2007 and 2020. METHODS: We analysed data collected from adults who smoked factory-made and/or roll-your-own (RYO) cigarettes in nine waves (2007-2020) of the International Tobacco Control Policy Evaluation Project Australia Survey (nsample=5452, nobservations=11 534). The main outcome measures were type of tobacco products purchased: RYO, carton, pack or pouch size and brand segment. Logistic regression, fit using generalised estimating equations, was estimated the association between the outcome and participant characteristics. RESULTS: The reported price-minimising purchasing patterns increased from 2007 to 2020: any RYO (23.8-43.9%), large-sized pack (2007: 24.0% to 2016: 34.3%); shifting from large-sized to small-sized packs (2020: 37.7%), and economy brand (2007: 37.2% to 2020: 59.3%); shifting from large (2007: 55.8%) to small economy packs (2014: 15.3% to 2020: 48.1%). Individuals with a lower income, a higher nicotine dependence level and no quit intention were more likely to purchase RYO and large-sized packs. CONCLUSION: RYO, large-sized packs and products with a low upfront cost (eg, small RYO pouches and small-sized economy brand packs) may appeal to people on low incomes. Australia's diverse tobacco pack and pouch sizes allow the tobacco industry to influence tobacco purchases. Standardising pack and pouch sizes may reduce some price-related marketing and especially benefit people who have a low income, are highly addicted and have no quit intention.

Demand for Factory-Made Cigarettes and Roll-Your-Own Tobacco and Differences Between Age and Socioeconomic Groups: Findings From the International Tobacco Control Netherlands Survey.

INTRODUCTION: Macroeconomic studies have shown that young individuals who smoke, and have a low socioeconomic status respond more strongly to price increases. Most of this evidence stems from research on factory-made (FM) cigarettes. With the rising popularity of roll-your-own (RYO) tobacco, there is a need for studies on cigarette demand that distinguish between both. AIMS AND METHODS: This study examined whether individual demand differed for FM and RYO tobacco, and across age, and socioeconomic (income and education) groups. Purchase tasks for FM and RYO cigarettes were included in the 2020 International Tobacco Control (ITC) Netherlands Survey. Adults who smoke daily (n = 1620) stated how many cigarettes they would smoke in 24 hours across eight prices. Four demand indices were derived: intensity (consumption at zero costs), alpha (rate of change in elasticity), Pmax (turning point elasticity), and breakpoint (lowest price where consumption equals zero). The indices were tested for subgroup differences. RESULTS: Individuals who smoke RYO tobacco indicated higher intensity, and greater alpha than individuals who smoke FM cigarettes. Participants aged 25-39 had lower Pmax, and 18-24 year olds displayed higher breakpoints. Participants with low income displayed higher intensity, and lower Pmax than other income groups. No associations were found with education. CONCLUSIONS: Individuals who smoke RYO tobacco indicated higher price sensitivity than those smoking FM cigarettes, supporting the need to harmonize tobacco taxation. Taxation may be especially beneficial to reducing consumption among individuals with a low income or smoke RYO tobacco. Substantially higher prices are needed in the Netherlands to achieve the desired results. IMPLICATIONS: Individuals who smoke daily were willing to pay substantially higher prices than the current market prices, indicating the room and need for much higher taxation levels. Demand for RYO tobacco was more sensitive to price changes than demand for FM cigarettes. Taxation should be raised at equivalent rates for FM and RYO cigarettes. Taxation appears to be especially effective in reducing consumption among people who smoke RYO tobacco and low-income individuals. It remains important to combine increased taxation with other tobacco control measures.

Excise taxes and pricing activities of e-liquid products sold in online vape shops.

BACKGROUND: Although e-cigarette excise taxes have great potential to prevent the initiation and escalation of e-cigarette use, little information is available on pricing activities of online vape shops, and how well taxation is implemented during web-based sales remains unclear. OBJECTIVES: We examine e-liquid pricing activities in popular online vape shops that sell nationwide in the USA and present how those stores charge excise taxes based on shipping addresses in states and local jurisdictions that have e-cigarette taxation in place. METHODS: We collect e-liquid sales prices from five online vape shops using web data extraction, standardise prices for e-liquid products, and present e-liquid price distribution in the whole sample and in each store, as well as variations of excise taxes across states/local jurisdictions and between stores. The price data were scraped from the store websites from February to May in 2021. RESULTS: We collected data on 14 477 e-liquid products from five stores. The average price of e-liquids is $0.25/mL, and the median price is $0.20/mL in our sample. E-liquid products sold online are very affordable and the average prices are lower compared with price estimates using other sources (eg, self-reports, sales data). In addition, online stores charge state excise taxes inconsistently and fail to comply with county-level or city-level excise taxes. CONCLUSION: E-liquid products sold online are priced low, and stricter enforcement of e-cigarette excise tax is needed in online purchasing channels.

MXenes: Synthesis, Optical Properties, and Applications in Ultrafast Photonics.

Recently, 2D materials are in great demand for various applications such as optical devices, supercapacitors, sensors, and biomedicine. MXenes as a kind of novel 2D material have attracted considerable research interest due to their outstanding mechanical, thermal, electrical, and optical properties. Especially, the excellent nonlinear optical response enables them to be potential candidates for the applications in ultrafast photonics. Here, a review of MXenes synthesis, optical properties, and applications in ultrafast lasers is presented. First, aqueous acid etching and chemical vapor deposition methods for preparing MXenes are introduced, in which the storage stability and challenges of the existing synthesis techniques are also discussed. Then, the optical properties of MXenes are discussed specifically, including plasmonic properties, optical detection, photothermal effects, and ultrafast dynamics. Furthermore, the typical ultrafast pulsed lasers enabled by MXene-based saturable absorbers operated at different wavelength regions are summarized. Finally, a summary and outlook on the development of MXenes is presented in the perspectives section.

Price, Income, and Affordability as the Determinants of Tobacco Consumption: A Practitioner's Guide to Tobacco Taxation.

INTRODUCTION: Tobacco product prices and consumers' income are the two major economic determinants of tobacco demand. The affordability of tobacco products is dependent on the price of tobacco products relative to consumer income. Increase in tobacco tax is expected to lead to higher price, lower affordability, and reduced consumption. Price elasticity and affordability elasticity are used in analyzing the effect of tobacco tax increases on tobacco consumption and public health. The availability of both parameters raises the question of which one to apply in policy discussions. AIMS AND METHODS: Using global data on cigarette consumption, price, income, and tobacco control measures for 169 countries over 2007-2016, this study estimated the price elasticity and affordability elasticity of cigarette consumption by country income classification using country-specific fixed effects model for panel data. RESULTS: The estimates show that the restriction of equal strength of the effects of price and income changes on tobacco consumption maintained in affordability elasticity estimation is valid for low- and middle-income countries, while it is rejected for high-income countries. CONCLUSIONS: Affordability elasticity may prove to be a useful parameter to explain and predict the sensitivity of consumers to tobacco tax and price policy changes under conditions of robust economic growth, which are more likely to be observed in countries with initial low- or middle-income setting. It can provide a reasonable benchmark for tobacco tax and price increase necessary to effectively reduce affordability and consumption of tobacco, which can form a basis for building systematic tax and price increases into the tobacco tax policy mechanism. IMPLICATIONS: Price elasticity measures the sensitivity of consumers to changes in real prices, holding real income constant. Affordability elasticity measures the sensitivity of consumers to price changes adjusted for inflation and income changes. Existing scientific literature on tobacco demand abounds in both price and affordability elasticity estimates, without providing a clear explanation of the theoretical and policy implications of using one parameter over the other. By estimating and comparing price and affordability elasticities for high-income and low-and-middle-income countries separately, this article offers a guide to the practitioners in tobacco taxation for evaluating the effectiveness of tax-induced price increases on tobacco consumption.

Costs of vaping: evidence from ITC Four Country Smoking and Vaping Survey.

STUDY OBJECTIVES: To compare the prices paid for nicotine vaping products (NVPs) and supplies among current NVP users to prices paid for cigarettes among current smokers. DATA: The 2016 International Tobacco Control Four Country Vaping and Smoking Survey (4CV1). Key measures included: (1) self-reported prices paid for reusable NVPs (eg, rechargeable devices with cartridges and tank system devices with e-liquids) in the 3-month period prior to the survey among current NVP users, (2) prices paid for disposable NVPs, cartridges and e-liquids purchased in the last 30 days among current NVP users and (3) self-reported prices paid for cigarettes among current smokers. RESULTS: Disposable NVP price was higher than the price of a comparable unit for combustible cigarettes in England (EN), USA and Canada (CA). Prefilled cartridge price was higher than the price of a comparable unit of cigarettes in USA and CA, but lower in EN and Australia. E-liquid price was consistently lower than the price of a comparable unit of cigarettes across four countries. For start-up costs, price of a rechargeable device is approximately 3-5 times higher than a pack of cigarettes in four countries. CONCLUSION: NVP prices were generally higher than prices of combustible cigarettes, especially the high upfront NVP devices. The high upfront costs of purchasing a reusable NVP may discourage some smokers from switching to vaping. However, the average lower costs of cartridges and e-liquids relative to a package of cigarettes make switching to a NVP an attractive alternative to smoking in the long term so long as smokers switch completely to vaping.

The harmonizing effect of Smart Snacks on the association between state snack laws and high school students' fruit and vegetable consumption, United States-2005-2017.

Despite national guidelines recommending daily fruit and vegetable (FV) consumption, intake of FV among adolescents is low. Over the past 10-15 years, state and federal laws have reduced the availability of junk foods in schools. This study examined the association between state snack laws and high school (HS) student FV consumption. The overall sample included 99,785 HS students (outcome samples ranged from 96,209-97,328) included in the Youth Risk Behavior Survey (YRBS). National Cancer Institute Classification of Laws Associated with School Students' data for 2004-2016 were lagged on to 2005-2017 YRBS data. Separate analyses examined the state law-youth FV consumption relationship pre- and post-federal Smart Snacks standards (effective school year 2014-2015). Analyses were conducted between 2018 and 2020. Overall, state laws were associated with any vegetable, salad, and other vegetable consumption. The relationship between state laws and vegetable consumption primarily occurred pre-Smart Snacks. Pre-Smart Snacks, state laws were associated with higher odds of youth consumption of any vegetable, salad, carrots, and other vegetables (all compared to students in states without snack laws). The only association post-Smart Snacks was between strong state laws and salads. This study illustrates the important role that standards restricting the availability of junk foods in schools can have on increasing student vegetable consumption. Given current efforts to roll-back federal school meal standards, findings from this study illustrate how federal standards harmonized the patchwork of state laws that existed prior to Smart Snacks and the important role that consistent national standards can play in supporting student consumption of vegetables.

Research on Youth and Young Adult Tobacco Use, 2013-2018, From the Food and Drug Administration-National Institutes of Health Tobacco Centers of Regulatory Science.

The Tobacco Regulatory Science Program is a collaborative research effort between the National Institutes of Health (NIH) and the Food and Drug Administration (FDA). In 2013, the NIH funded 14 Tobacco Centers of Regulatory Science (TCORS), which serve as partners in establishing research, training, and professional development programs to guide FDA. Each of the fourteen TCORS, and two other NIH-funded research programs, the Center for the Evaluation of Nicotine in Cigarettes (CENIC) and the Consortium on Methods Evaluating Tobacco (COMET), pursued specific research themes relevant to FDA's priorities. A key mandate for FDA is to reduce tobacco use among young people. This article is a review of the peer-reviewed research, including published and in-press manuscripts, from the TCORS, CENIC, and COMET, which provides specific data or other findings on youth (ages 10-18 years) and/or young adults (ages 18-34 years), from 2013 to 2018. Citations of all TCORS, CENIC, and COMET articles from September 2013 to December 2017 were collected by the TCORS coordinating center, the Center for Evaluation and Coordination of Training and Research. Additional citations up to April 30, 2018 were requested from the principal investigators. A scoring rubric was developed and implemented to assess study type, primary theme, and FDA priority area addressed by each article. The major subareas and findings from each priority area are presented. There were 766 articles in total, with 258 (34%) focusing on youth and/or young adults. Findings relevant to FDA from this review concern impact analysis, toxicity, health effects, addiction, marketing influences, communications, and behavior. IMPLICATIONS: The Tobacco Centers of Regulatory Science, CENIC, and COMET have had a high output of scientific articles since 2013. These Centers are unique in that the FDA supports science specifically to guide future regulatory actions. The 258 articles that have focused on youth and/or young adults are providing data for regulatory actions by the FDA related to the key priority areas such as the addictiveness of non-cigarette products, the effects of exposure to electronic cigarette marketing on initiation and cessation, and the impact of flavored products on youth and young adult tobacco use. Future regulations to reduce tobacco use will be guided by the cumulative evidence. These Centers are one innovative mechanism to promote important outcomes to advance tobacco regulatory science.

Localization and Anderson delocalization of light in fractional dimensions with a quasi-periodic lattice.

We address the properties of wavepacket localization-delocalization transition (LDT) in fractional dimensions with a quasi-periodic lattice. The LDT point, which is generally determined by the competition between two sub-lattices comprising the quasi-periodic lattice, turns out to be inversely proportional to the Lévy index. Surprisingly, we find that, in the presence of weak structural disorder, anti-Anderson localization occurs, i.e., the introduced disorder results in an increasing of the size of the linear modes. Inclusion of a weak focusing nonlinearity is shown to improve localization. The propagation simulation achieves excellent agreement with the linear and nonlinear eigenmode analysis.

Retinoid X Receptor Alpha Nitro-ligand Z-10 and Its Optimized Derivative Z-36 Reduce ß-Amyloid Plaques in Alzheimer's Disease Mouse Model.

Bexarotene, an agonist of retinoid X receptor alpha (RXRα), has been shown to increase the expression of apoE, ABCA1, and ABCG1 by activating RXR/LXR and RXR/PPAR heterodimers, resulting in amyloid ß (Aß)-protein clearance in the brain of an Alzheimer's disease (AD) mouse model and reversal of mouse cognitive deficits. Nitrostyrene derivative Z-10 is the first identified nitro-ligand of RXRα. We hypothesized that Z-10 and its derivatives have the similar effect as bexarotene. A series of Z-10 derivatives were synthesized by introducing methoxyl, hydroxyl, and methoxy groups in 2- or 4-position of naphthalene ring, respectively. Our reporter gene assays showed that the derivatives with substituted groups of methyl and methoxyl in position 2 were more potent to activate Gal4-DBD/RXRα-LBD and RXRα homodimer as well as RXRα heterodimers than the corresponding 4-substituted derivatives. The derivatives with hydroxyl substitution in either 2- or 4-position failed to activate RXRα. Consistently, the derivatives with stronger potency of RXRα activation had higher RXRα binding affinity. Z-10 and its 2-ethyoxyl substituted derivative Z-36 reduced Aß plaques in both hippocampus and cortex of AD mouse model significantly, of which Z-36 had stronger efficacy. This may due to the stronger ability of Z-36 than Z-10 in activating RXR/LXR and RXR/PPAR heterodimers and inducing ABCA1 and ABCG1 expressions. Thus, the 2- rather than 4-position was the better site for Z-10 modification as to RXRα transactivation, and Z-36 is an optimized derivative of Z-10 as to reducing Aß plaques in AD mouse model.

Tobacco taxation, illegal cigarette supply and geography: findings from the ITC Uruguay Surveys.

BACKGROUND: In Uruguay, real tobacco taxes increased significantly during 2005-2010 and 2014-2017 and decreased during 2010-2014. The effects of these tax changes on illegal and legal cigarette usage differed significantly when we compared cities in the middle and south of the country with cities on the border. OBJECTIVE: This paper analyses whether supply side factors such as geographical location, distribution networks and the effectiveness of tobacco control play a significant role in sales and use of illegal cigarettes when tobacco taxes change, particularly given the price gap between legal and lower-priced illegal cigarettes. METHODS: Using the International Tobacco Control Evaluation Project Uruguay Survey data (2008, 2010, 2012 and 2014), choices among illegal, legal and roll-your-own cigarettes are estimated as a function of smokers' geographical location, an indicator of illegal cigarette supply, and controlling for socioeconomic and demographic variables. Smoking behaviours in Montevideo, Durazno and Maldonado were compared with those in two border cities, Salto and Rivera, where illegal cigarette prevalence may differ. FINDINGS: An increase in taxes on manufactured legal and roll-your-own cigarettes increased the odds that smokers in cities near the borders and women switched down to illegal cigarettes. City geographical location, controls effectiveness and distribution networks may play a significant role in accessibility of illegal cigarettes. To improve the effectiveness of increased taxes and prices in reducing smoking, policy-makers may consider specific policies intended to reduce access to illegal cigarettes, such as ratification and effective implementation of the Protocol to Eliminate Illicit Trade in Tobacco Products of WHO.

Association between tobacco prices and smoking onset: evidence from the TCP India Survey.

BACKGROUND: Tobacco use is prevalent among youth and adults in India. However, direct evidence on how increasing taxes or prices affect tobacco use onset is scarce. OBJECTIVE: To analyse the associations between cigarette and bidi prices and smoking onset in India, and how these associations differ by socioeconomic status. METHODOLOGY: The Wave 1 of the Tobacco Control Policy Evaluation India Survey by the International Tobacco Control Project contains information on the age at smoking onset for cigarettes and bidis. Using this information, data were expanded to a yearly pseudo-panel dataset that tracked respondents at risk of smoking onset from 1998 to 2011. The associations between bidi prices and bidi smoking onset, between cigarette prices and cigarette smoking onset, and between bidi and cigarette prices and any smoking onset were examined using a discrete-time hazard model with a logit link function. Stratified analyses were conducted to examine the difference in these associations by rural versus urban division. RESULTS: We found that higher bidi prices were significantly associated with a lowered hazard of bidi smoking onset (OR 0.42, 95% CI 0.35 to 0.51). Higher cigarette prices were significantly (OR 0.87, 95% CI 0.83 to 0.92) associated with a lowered hazard of cigarette smoking onset among urban residents, but this association was non-significant when SEs were clustered at the state level. In addition, the association between increasing bidis prices and lowered hazards of bidi smoking onset was greater for urban residents than for rural ones (p<0.01). CONCLUSIONS: Under the new regime of a central goods and service system, policymakers may need to raise the prices of tobacco products sufficiently to curb smoking onset.

Association between tax structure and cigarette consumption: findings from the International Tobacco Control Policy Evaluation (ITC) Project.

BACKGROUND: Recent studies show that greater price variability and more opportunities for tax avoidance are associated with tax structures that depart from a specific uniform one. These findings indicate that tax structures other than a specific uniform one may lead to more cigarette consumption. OBJECTIVE: This paper aims to examine how cigarette tax structure is associated with cigarette consumption. METHODS: We used survey data taken from the International Tobacco Control Policy Evaluation Project in 17 countries to conduct the analysis. Self-reported cigarette consumption was aggregated to average measures for each surveyed country and wave. The effect of tax structures on cigarette consumption was estimated using generalised estimating equations after adjusting for sociodemographic characteristics, average taxes and year fixed effects. FINDINGS: Our study provides important empirical evidence of a relationship between tax structure and cigarette consumption. We find that a change from a specific to an ad valorem structure is associated with a 6%-11% higher cigarette consumption. In addition, a change from uniform to tiered structure is associated with a 34%-65% higher cigarette consumption. The results are consistent with existing evidence and suggest that a uniform and specific tax structure is the most effective tax structure for reducing tobacco consumption.