Waterpipe smoking in students: Prevalence, risk factors, symptoms of addiction, and smoke intake. Evidence from one British university

Background: Anecdotal reports suggest waterpipe smoking is becoming common in students in western countries. The aim was to examine prevalence, risk factors, symptoms of addiction, and smoke intake. Methods: This was a cross-sectional survey of students with subsidiary survey of regular waterpipe user and survey of exhaled carbon monoxide (CO) before and after waterpipe smoking in customers of a waterpipe café. 937 students of Birmingham University completed the initial survey with a follow up of 21 regular waterpipe smokers. 63 customers of a waterpipe café near the University completed the study of CO intake. Results: 355 (37.9%, 95% confidence intervals (CI) 34.8 to 41.1%) students had tried waterpipes,the prevalence of trying rising with duration at University. 75 (8.0%, 95%CI 6.4 to 10.0%) were regular smokers, similar to the prevalence of cigarette smoking (9.4%). Although cigarette smoking was the major risk factor for being a regular waterpipe smoker, odds ratio (95%CI) 2.77 (1.52 to 5.06), 65% of waterpipe smokers did not smoke cigarettes. Seven of 21 (33.3%) regular waterpipe smokers experienced cravings. Nearly all regular waterpipe users thought it less harmful than smoking cigarettes. The mean (standard deviation) rise in CO was 37.4 (25.8)ppm, nearly twice as high as a typical cigarette smoker seeking cessation treatment. Conclusion: Waterpipe smoking is a common part of student culture in one British university, as in the Middle East and in the United States. It poses a potential threat to public health, with evidence of dependence and high smoke intake

Graded modules over the simple Lie algebra sl2(C)

This thesis provides a contribution to the area of group gradings on the simple modules over simple Lie algebras. A complete classification of gradings on finite-dimensional simple modules over arbitrary finite-dimensional simple Lie algebras over algebraically closed fields of characteristic zero, in terms of graded Brauer groups, has been recently given in the papers of A. Elduque and M. Kochetov. Here we concentrate on infinite-dimensional modules. A complete classification by R. Block of all simple modules over a simple Lie algebra is known only in the case of sl2(C). Thus, we restrict ourselves to the gradings on simple sl2(C)-modules. We first give a full description for the Z- and Z₂² -gradings of all weight modules over sl₂(C). Then we show that Z-gradings do not exist on any torsion-free sl₂(C)-modules of finite rank. After this, we treat Z₂² -gradings on torsion-free modules of various ranks. A construction for these modules was given by V. Bavula, and J. Nilson gave a classification of the torsion-free sl₂(C)-modules of rank 1. After giving some, mostly negative, results about the gradings on these latter modules, we construct the first family of simple Z₂² -graded sl₂(C)-modules (of rank 2). We also construct a family of graded-simple torsion-free modules of rank 2. For each of the modules in these families, we give a complete description of their tensor products with simple graded finite-dimensional modules. we restrict ourselves to the gradings on simple sl₂(C)-modules. We first give a full description for the Z- and Z₂² -gradings of all weight modules over sl₂(C). Then we show that Z-gradings do not exist on any torsion-free sl₂(C)-modules of finite rank. After this, we treat Z₂² -gradings on torsion-free modules of various ranks. A construction for these modules was given by V. Bavula, and J. Nilson gave a classification of the torsion-free sl₂(C)-modules of rank 1. After giving some, mostly negative, results about the gradings on these latter modules, we construct the first family of simple Z₂² -graded sl₂(C)-modules (of rank 2). We also construct a family of graded-simple torsion-free modules of rank 2. For each of the modules in these families, we give a complete description of their tensor products with simple graded finite-dimensional modules

On transport phenomena and equilibration time scales in thermodenuders

This paper presents a theoretical and experimental investigation of thermodenuders that addresses two controversial issues: (1) equilibration time scales and (2) the need for an activated carbon (AC) denuder in the cooling section. We describe a plug flow model for transport phenomena in a TD, which can be used to simulate the rate of vapor build-up in the gas phase and the corresponding change in particle size distribution. Model simulations were found to have excellent agreement with experiments performed with pure and mixed dicarboxylic acid aerosols. Both simulations and experiments showed that the aerosols approached equilibrium within reasonable residence times (15 s–30 s) for aerosol concentrations and size distributions typical for laboratory measurements, and that volatility studies at sufficiently high aerosol loadings, therefore, need not resort to kinetic models for inference of thermodynamic properties. However, for size distributions relevant for ambient aerosols, equilibration time scales were much larger than residence times available with current TD designs. We have also performed dimensional analysis on the problem of equilibration in TDs, and derived a dimensionless equilibration parameter which can be used to determine the residence time needed for an aerosol of given size distribution and kinetic properties to approach equilibrium. It is also shown theoretically and empirically that aerosol volatility has no effect on the equilibration time scales. Model simulations and experiments showed that with aerosol size distributions relevant to both ambient and laboratory measurements re-condensation in the cooling section, with and without an AC denuder, was negligible. Thus, there is no significant benefit in using an AC denuder in the cooling section. Due to the risk of stripping volatile material from the aerosol, the use of AC denuders in the cooling section should be avoided. Finally, we present a rationale for why Δ<i>C</i> is the proper measure of volatility, while using mass fraction remaining (MFR) can be misleading

Bamboo Application In Building Design : Case Study Of Green School, Bali, Indonesia

Bamboo has been known widely as a material for buildings since the dawn of the century. Nevertheless, bamboo is often regarded as a lowclass building material which has commonly used by low-income people. Since the issue of global warming and sustainability, bamboo became a focus for building material due to its sustenance and fast growth in the natural environment. Architects and builders alike started to choose bamboo as an alternative to wood. Furthermore, it is difficult to get good-quality woods for construction and historically, a vast tract of land has been ruined due to deforestation that caused an adverse effect on the surroundings. This paper attempts to discuss the properties of bamboo and how it is inventively applied in building design. Descriptive-qualitative methods were used in this study to reveal an understanding of the application of bamboo in building design. To further enhance the finding and context of discussing a case study on how bamboo has been used in designing the structure in an innovative organic form. The result from this research found out that bamboo is noble to be considered as an alternative material in building design due to its natural properties, exclusively for curvilinear organic-form building that hardly achieved in steel and concrete

A critique of the WHO TobReg's "Advisory Note" report entitled: "Waterpipe tobacco smoking: health effects, research needs and recommended actions by regulators"

BACKGROUND AND AIM: The World Health Organisation Study Group on Tobacco Product Regulation (TobReg) has issued in 2005 an "Advisory Note" entitled: "Waterpipe Tobacco Smoking: Health Effects, Research Needs and Recommended Actions by Regulators". "Waterpipe" smoking is now considered a global public health threat and the corresponding artefact is actually known in the world under three main terms: hookah, narghile and shisha. This important report, the first ever prepared by WHO on the subject, poses two major problems. On one hand, its bibliographical references dismiss world chief relevant studies. On the other, it contains a certain number of errors of many orders: biomedical, sociological, anthropological and historical. The purpose of the present study is to highlight, one by one, where these weaknesses and errors lie and show how this official report can be considerably improved. RESULTS: We realise that widely advertised early anthropological studies were not taken into consideration whereas they shed a substantial light on this peculiar form of smoking and help understanding its high complexity. As for concrete errors to be found in this report, they deal with the chemistry of smoke, health-related effects, smoking patterns, description and history of the artefact and its use, gender and underage use aspects, prevention and research needs in this field. CONCLUSION: The scientific credibility of an international expert report may be at stake if its recommendations do not rely on sound objective research findings and a comprehensive review of the existing literature. The critical comments in this study will certainly help improve the present WHO report

The Effect of Urban Street Gang Densities on Small Area Homicide Incidence in a Large Metropolitan County, 1994–2002

The presence of street gangs has been hypothesized as influencing overall levels of violence in urban communities through a process of gun–drug diffusion and cross-type homicide. This effect is said to act independently of other known correlates of violence, i.e., neighborhood poverty. To test this hypothesis, we independently assessed the impact of population exposure to local street gang densities on 8-year homicide rates in small areas of Los Angeles County, California. Homicide data from the Los Angeles County Coroners Office were analyzed with original field survey data on street gang locations, while controlling for the established covariates of community homicide rates. Bivariate and multivariate regression analyses explicated strong relationships between homicide rates, gang density, race/ethnicity, and socioeconomic structure. Street gang densities alone had cumulative effects on small area homicide rates. Local gang densities, along with high school dropout rates, high unemployment rates, racial and ethnic concentration, and higher population densities, together explained 90% of the variation in local 8-year homicide rates. Several other commonly considered covariates were insignificant in the model. Urban environments with higher densities of street gangs exhibited higher overall homicide rates, independent of other community covariates of homicide. The unique nature of street gang killings and their greater potential to influence future local rates of violence suggests that more direct public health interventions are needed alongside traditional criminal justice mechanisms to combat urban violence and homicides

Meaning and definition:Skepticism and semantics in twelfth-century Arabic Philosophy

The theory of essential definitions is a fundamental anti-sceptic element of the Aristotelian-Avicennian epistemology. In this theory, when we distinguish the genus and the specific differentia of a given essence we thereby acquire a scientific understanding of it. The aim of this article is to analyse systematically the sceptical reasons, arguments and conclusions against real definitions of three major authorities of twelfth-century Arabic philosophy: Fahr al-Din al-Razi, Sihab al-Din al-Suhrawardi and Abu l-Barakat al-Badadi. I focus on showing how their refutation of our capacity to provide essential definitions of things is rooted in their semantic theory: we only know things under certain descriptions which are identical to the meanings of the words that we use to refer to them, yet these descriptions do not capture the essences of things in themselves. The best result one can achieve with Aristotelian-Avicennian scientific definitions is a "nominal definition". With this, Razi, Suhrawardi and Abu l-Barakat will put some serious epistemic limitations on our capacity to attain scientific knowledge of things, at least as Aristotle and Avicenna would have it

Comparison of patterns of use, beliefs, and attitudes related to waterpipe between beginning and established smokers

BACKGROUND: To compare patterns of use, beliefs, and attitudes related to waterpipe smoking between university students (beginning smokers) and café customers (established smokers) in Aleppo Syria, in order to explore the evolution of this smoking method. METHODS: Two cross-sectional surveys were conducted among representative samples of university students (total 587, 48.4% men, mean age 22 years), and waterpipe users among cafe' customers (total 268, 60% men, mean age 30 years) in Aleppo, Syria. We used interviewer-administered questionnaire inquiring about pattern of waterpipe smoking (initiation, frequency), situational characteristics of use (partner, place, sharing), beliefs related to waterpipe smoking (harmful/addictive properties of waterpipe), attitudes related to waterpipe smoking (confidence in quitting, will to quit, motivation for quitting, past year quit attempt), and cigarette smoking. RESULTS: Daily and regular patterns of smoking become more prevalent with increased duration of smoking, but intermittent smoking remains the predominant pattern of waterpipe use. Women seem to be drawn later to the habit, which seem to escape the usual taboo against women's cigarette smoking. Patterns and context of waterpipe use tend to change with progress of the practice affecting frequency, setting, and sharing of waterpipe. Unlike beginners, established waterpipe smokers seem more smoking-method oriented, more hooked on the habit, less willing to quit, and less likely to foresee challenges to quitting. CONCLUSION: Use patterns and attitudes related to waterpipe smoking evolve to accommodate the change in dependence and life circumstances of the smoker. Most of use features, beliefs, attitudes, as well as time-course seem unique to this smoking method requiring novel approach to intervention