Altadis is a Spanish-French multinational purveyor and manufacturer of cigarettes, tobacco and cigars. It was formed via a 1999 merger between Tabacalera, the former Spanish tobacco monopoly and SEITA, the former French tobacco monopoly. Through its international holdings, including ownership of the former Consolidated Cigar Holdings and half ownership of the Cuban state tobacco monopoly, Habanos S.A., Altadis was the largest producer of mass market and premium cigars in the world, as well as the fourth largest producer of tobacco products.The company was acquired by the British tobacco giant Imperial Tobacco (now Imperial Brands) in 2008, becoming a subsidiary of it.
GCxGC is a very powerful technique for the complex sample analysis because it combines two mechanisms of separation, according to the volatility and polarity of compounds. The modulator is the key part of any GCxGC system: it periodically collects, focuses and launches the eluted materials from the primary column to the second column while the integrity of the first separation is not modified by this process. Since the modulation takes place in the first centimeters of the second column inlet, the type of stationary phase used in the second separation plays a very important role in the efficiency of carbon dioxide cryogenic modulation. In this study, different types of stationary phases were considered. The obtained results demonstrated that for the modulation of various classes of organic compounds a stationary phase of medium polarity (50% phenyl 50% methylpolysiloxane) was the best compromise, all the other conditions of separation being kept constant. On the contrary, a column without stationary phase (only fused silica) and a column with a polar stationary phase (100% polyethylene glycol) are clearly inadequate for modulation due to the lack of adequate interactions. For this reason the overloading of the second column is likely occurring.
Chemiluminescence detection of reactive oxygen species (ROS) triggered in tobacco BY-2 cells by the fungal elicitor cryptogein was previously demonstrated to be abolished in cells transformed with an antisense construct of the plasma membrane NADPH oxidase, NtrbohD. Here, using electron microscopy, it has been confirmed that the first hydrogen peroxide production occurring a few minutes after challenge of tobacco cells with cryptogein is plasma membrane located and NtrbohD mediated. Furthermore, the presence of NtrbohD in detergent-resistant membrane fractions could be associated with the presence of NtrbohD-mediated hydrogen peroxide patches along the plasma membrane. Comparison of the subcellular localization of ROS in wild-type tobacco and in plants transformed with antisense constructs of NtrbohD revealed that this enzyme is also responsible for the hydrogen peroxide production occurring at the plasma membrane after infiltration of tobacco leaves with cryptogein. Finally, the reactivity of wild-type and transformed plants to the elicitor and their resistance against the pathogenic oomycete Phytophthora parasitica were examined. NtrbohD-mediated hydrogen peroxide production does not seem determinant for either hypersensitive response development or the establishment of acquired resistance but it is most likely involved in the signaling pathways associated with the protection of the plant cell.
In this work, we consider chemical and physical variable groups describing a common set of observations (cigarettes). One of the groups, minor smoke compounds (minSC), is assumed to depend on the others (minSC predictors). PLS regression (PLSR) of m inSC on the set of all predictors appears not to lead to a satisfactory analytic model, because it does not take into account the expert's knowledge. PLS path modeling (PLSPM) does not use the multidimensional structure of predictor groups. Indeed, the expert needs to separate the influence of several pre-designed predictor groups on minSC, in order to see what dimensions this influence involves. To meet these needs, we consider a multi-group component-regression model, and propose a method to extract from each group several strong uncorrelated components that fit the model. Estimation is based on a global multiple covariance criterion, used in combination with an appropriate nesting approach. Compared to PLSR and PLSPM, the structural equation exploratory regression (SEER) we propose fully uses predictor group complementarity, both conceptually and statistically, to predict the dependent group.
Spectra, obtained in visible and near infrared spectral regions, contain much information whose interest depends on the context. For instance, in a discrimination context, the only information of interest is the one, concerning the differences between groups. This is our problem and we want to determine zones in the spectra (intervals), allowing a good discrimination between groups defined in advance. In that goal, genetic algorithms (GAs) will be used as a method of feature (wavelengths) selection. The Fisher Linear Discriminant Analysis (or Factorial Discriminant Analysis denoted FDA) will be applied on the selected variables. The efficiency of the method is shown on the discrimination of tobacco products. Copyright (c) 2007 John Wiley & Sons, Ltd.
Abstract The Smoking Behaviour Sub Group of the Cooperation Centre for Scientific Research Relative to Tobacco (CORESTA) was set up in 1996 with the aims of reviewing information relevant to smoking behaviour, publishing the reviews, identifying gaps in information and suggesting suitable studies. So far three reviews have been published by members of the sub group (1-3) and other reviews are in progress. One aspect of the subject that has become apparent to the sub group is that terms are used inconsistently in various papers on smoking behaviour. We therefore propose that the following terms and their definitions are used in the future.
