Lie algebras and 3-transpositions

We describe a construction of an algebra over the field of order 2 starting from a conjugacy class of 3-transpositions in a group. In particular, we determine which simple Lie algebras arise by this construction. Among other things, this construction yields a natural embedding of the sporadic simple group \Fi{22} in the group $^2E_6(2)$.Comment: 23 page

Practical, reliable and inexpensive assay of lycopene in tomato products based on the combined use of light emitting diode (LED) and the optothermal window

Light emitting diode (LED) combined with the concept of optothermal window (OW) is proposed as a new approach (LED-OW) to detect lycopene in a wide range of tomato-based products (tomato juice, tomato ketchup, tomato passata and tomato puree). Phytonutrient lycopene is a dominant antioxidant in these products while beta-carotene is present in significantly lower quantities. Therefore for all practical reasons the interfering effect of beta-carotene at 502 nm analytical wavelength can be neglected. The LED-OW method is low-cost and simple, yet accurate and precise. The major attributes of the new method are its rapid speed of response and the fact that no preparation whatsoever of the sample is needed before the analysis. The lycopene found in tomato products studied here varies from 8 mg/100 g to 60 mg/100 g fresh product. Results obtained by LED-OW method were compared to the outcome of conventional, time consuming spectrophotometric methods and the correlation was very good (R = 0.98). Precision of the LED-OW instrumental setup ranged from 0.5 to 7.4%; the RSD achieved for lycopene-richest samples (= 40 mg/100 g) did not exceed 1.7%. Repeatability of analysis by LED-OW was found to vary between 0.7 and 7.1%

Automated supervised classification of variable stars I. Methodology

The fast classification of new variable stars is an important step in making them available for further research. Selection of science targets from large databases is much more efficient if they have been classified first. Defining the classes in terms of physical parameters is also important to get an unbiased statistical view on the variability mechanisms and the borders of instability strips. Our goal is twofold: provide an overview of the stellar variability classes that are presently known, in terms of some relevant stellar parameters; use the class descriptions obtained as the basis for an automated `supervised classification' of large databases. Such automated classification will compare and assign new objects to a set of pre-defined variability training classes. For every variability class, a literature search was performed to find as many well-known member stars as possible, or a considerable subset if too many were present. Next, we searched on-line and private databases for their light curves in the visible band and performed period analysis and harmonic fitting. The derived light curve parameters are used to describe the classes and define the training classifiers. We compared the performance of different classifiers in terms of percentage of correct identification, of confusion among classes and of computation time. We describe how well the classes can be separated using the proposed set of parameters and how future improvements can be made, based on new large databases such as the light curves to be assembled by the CoRoT and Kepler space missions.Comment: This paper has been accepted for publication in Astronomy and Astrophysics (reference AA/2007/7638) Number of pages: 27 Number of figures: 1

The interpretation of hair analysis for drugs and drug metabolites

INTRODUCTION: Head hair analysis for drugs and drug metabolites has been used widely with the aim of detecting exposure in the weeks or months prior to sample collection. However, inappropriate interpretation of results has likely led to serious miscarriages of justice, especially in child custody cases.OBJECTIVE: The aim of this review is to assess critically what can, and perhaps more importantly, what cannot be claimed as regards the interpretation of hair test results in a given set of circumstances in order to inform future testing.METHODS: We searched the PubMed database for papers published 2010-2016 using the terms "hair" and "drug" and "decontamination", the terms "hair" and "drug" and "contamination", the terms "hair" and "drug-facilitated crime", the terms "hair" and "ethyl glucuronide", and the terms "hair", "drug testing" and "analysis". Study of the reference lists of the 46 relevant papers identified 25 further relevant citations, giving a total of 71 citations. Hair samples: Drugs, drug metabolites and/or decomposition products may arise not only from deliberate drug administration, but also via deposition from a contaminated atmosphere if drug(s) have been smoked or otherwise vaporized in a confined area, transfer from contaminated surfaces via food/fingers, etc., and transfer from sweat and other secretions after a single large exposure, which could include anesthesia. Excretion in sweat of endogenous analytes such as γ-hydroxybutyric acid is a potential confounder if its use is to be investigated. Cosmetic procedures such as bleaching or heat treatment of hair may remove analytes prior to sample collection. Hair color and texture, the area of the head the sample is taken from, the growth rate of individual hairs, and how the sample has been stored, may also affect the interpretation of results. Toxicological analysis: Immunoassay results alone do not provide reliable evidence on which to base judicial decisions. Gas or liquid chromatography with mass spectrometric detection (GC- or LC-MS), if used with due caution, can give accurate analyte identification and high sensitivity, but many problems remain. Firstly, it is not possible to prepare assay calibrators or quality control material except by soaking "blank" hair in solutions of appropriate analytes, drying, and then subjecting the dried material to an analysis. The fact that solvents can be used to add analytes to hair points to the fact that analytes can arrive not only on, but also in hair from exogenous sources. A range of solvent-washing procedures have been advocated to "decontaminate" hair by removing adsorbed analytes, but these carry the risk of transporting adsorbed analytes into the medulla of the hair therefore confounding the whole procedure. This is especially true if segmental analysis is being undertaken in order to provide a "time course" of drug exposure. Proposed clinical applications of hair analysis: There have been a number of reports where drugs seemingly administered during the perpetration of a crime have been detected in head hair. However, detailed evaluation of these reports is difficult without full understanding of the possible effects of any "decontamination" procedures used and of other variables such as hair color or cosmetic hair treatment. Similarly, in child custody cases and where the aim is to demonstrate abstinence from drug or alcohol use, the issues of possible exogenous sources of analyte, and of the large variations in analyte concentrations reported in known users, continue to confound the interpretation of results in individual cases.CONCLUSIONS: Interpretation of results of head hair analysis must take into account all the available circumstantial and other evidence especially as regards the methodology employed and the possibility of surface contamination of the hair prior to collection.</p

Chargino Production at an e-e- Collider

The chargino pair production in $e^-e^-$ collisions with their subsequent decays are considered within SUSY models with R-parity violation and with lepton number non-conservation. The production process ($\sqrt{s}=1$ TeV) is predicted to be large in a wide range of both sneutrino and chargino masses. The influence of all virtual sneutrino states and their mixings with electrons are taken into account. Some specific situations are pointed out when significant suppressions of the cross section can take place. The chargino decays are discussed for either the chargino as LSP or the chargino as heavier sparticle. In both cases unique signals are possible with up to six charged fermions and without missing energy.Comment: 9 page

Global stellar variability study in the field-of-view of the Kepler satellite

We present the results of an automated variability analysis of the Kepler public data measured in the first quarter (Q1) of the mission. In total, about 150 000 light curves have been analysed to detect stellar variability, and to identify new members of known variability classes. We also focus on the detection of variables present in eclipsing binary systems, given the important constraints on stellar fundamental parameters they can provide. The methodology we use here is based on the automated variability classification pipeline which was previously developed for and applied successfully to the CoRoT exofield database and to the limited subset of a few thousand Kepler asteroseismology light curves. We use a Fourier decomposition of the light curves to describe their variability behaviour and use the resulting parameters to perform a supervised classification. Several improvements have been made, including a separate extractor method to detect the presence of eclipses when other variability is present in the light curves. We also included two new variability classes compared to previous work: variables showing signs of rotational modulation and of activity. Statistics are given on the number of variables and the number of good candidates per class. A comparison is made with results obtained for the CoRoT exoplanet data. We present some special discoveries, including variable stars in eclipsing binary systems. Many new candidate non-radial pulsators are found, mainly Delta Sct and Gamma Dor stars. We have studied those samples in more detail by using 2MASS colours. The full classification results are made available as an online catalogue.Comment: 15 pages, 5 figures, Accepted for publication in Astronomy and Astrophysics on 09/02/201

Introduction: responsibility for action and belief

This paper is a presentation of a special issue of Philosophical Explorations, whose origin is a meeting held in Valencia in 2008. The issue includes contributions by David Widerker, Derk Pereboom, Timothy O'Connor, Thomas Pink, Dana Nelkin, Helen Steward, Maria Alvarez, Christopher Hookway, and Pascal Engel. The paper contains a map of the main positions in the debate about free action, free will, and moral responsibility, as well as a reference to some central issues in this traditional and yet lively debate. The discussion about responsibility and related notions, such as agency and freedom, has recently been extended from decisions and actions to beliefs, to give rise to new research perspectives, both in epistemology and in the metaphysics of freedom and responsibility for actions. The papers included in this special issue are valuable contributions to the research about freedom and responsibility in both action and belief