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Selected AbstractsPredicting species distributions from museum and herbarium records using multiresponse models fitted with multivariate adaptive regression splinesDIVERSITY AND DISTRIBUTIONS, Issue 3 2007Jane Elith ABSTRACT Current circumstances , that the majority of species distribution records exist as presence-only data (e.g. from museums and herbaria), and that there is an established need for predictions of species distributions , mean that scientists and conservation managers seek to develop robust methods for using these data. Such methods must, in particular, accommodate the difficulties caused by lack of reliable information about sites where species are absent. Here we test two approaches for overcoming these difficulties, analysing a range of data sets using the technique of multivariate adaptive regression splines (MARS). MARS is closely related to regression techniques such as generalized additive models (GAMs) that are commonly and successfully used in modelling species distributions, but has particular advantages in its analytical speed and the ease of transfer of analysis results to other computational environments such as a Geographic Information System. MARS also has the advantage that it can model multiple responses, meaning that it can combine information from a set of species to determine the dominant environmental drivers of variation in species composition. We use data from 226 species from six regions of the world, and demonstrate the use of MARS for distribution modelling using presence-only data. We test whether (1) the type of data used to represent absence or background and (2) the signal from multiple species affect predictive performance, by evaluating predictions at completely independent sites where genuine presence,absence data were recorded. Models developed with absences inferred from the total set of presence-only sites for a biological group, and using simultaneous analysis of multiple species to inform the choice of predictor variables, performed better than models in which species were analysed singly, or in which pseudo-absences were drawn randomly from the study area. The methods are fast, relatively simple to understand, and useful for situations where data are limited. A tutorial is included. [source] Personality terms of abuse in three cultures: type nouns between description and insultEUROPEAN JOURNAL OF PERSONALITY, Issue 2 2005Boele De Raad In this study terms of abuse are investigated in three different cultures. Spontaneous verbal aggression is to a certain extent reminiscent of the values of a certain culture. One hundred and ninety-two male subjects from Spain, Germany and the Netherlands were asked to write down terms of abuse that they would use given a certain stimulus situation, and in addition to give their rating of the offensive character of those terms. A total set of 830 useful expressions was thus collected. The frequencies of the expressions were established, and the total list of expressions was categorized in terms of what they were about. In Spanish abusive language is typically about family and relations, in Germany it is typically about anal aspects, and in the Netherlands it is mainly about genitals. Explanations are provided in terms of dimensions on which the three cultures differ. Copyright © 2004 John Wiley & Sons, Ltd. [source] Evaluation of library ranking efficacy in virtual screening,JOURNAL OF COMPUTATIONAL CHEMISTRY, Issue 1 2005Maria Kontoyianni Abstract We present the results of a comprehensive study in which we explored how the docking procedure affects the performance of a virtual screening approach. We used four docking engines and applied 10 scoring functions to the top-ranked docking solutions of seeded databases against six target proteins. The scores of the experimental poses were placed within the total set to assess whether the scoring function required an accurate pose to provide the appropriate rank for the seeded compounds. This method allows a direct comparison of library ranking efficacy. Our results indicate that the LigandFit/Ligscore1 and LigandFit/GOLD docking/scoring combinations, and to a lesser degree FlexX/FlexX, Glide/Ligscore1, DOCK/PMF (Tripos implementation), LigandFit1/Ligscore2 and LigandFit/PMF (Tripos implementation) were able to retrieve the highest number of actives at a 10% fraction of the database when all targets were looked upon collectively. We also show that the scoring functions rank the observed binding modes higher than the inaccurate poses provided that the experimental poses are available. This finding stresses the discriminatory ability of the scoring algorithms, when better poses are available, and suggests that the number of false positives can be lowered with conformers closer to bioactive ones. © 2004 Wiley Periodicals, Inc. J Comput Chem 26: 11,22, 2005 [source] Analyses of Digman's Child-Personality Data: Derivation of Big-Five Factor Scores From Each of Six SamplesJOURNAL OF PERSONALITY, Issue 5 2001Lewis R. Goldberg One of the world's richest collections of teacher descriptions of elementary-school children was obtained by John M. Digman from 1959 to 1967 in schools on two Hawaiian islands. In six phases of data collection, 88 teachers described 2,572 of their students, using one of five different sets of personality variables. The present report provides findings from new analyses of these important data, which have never before been analyzed in a comprehensive manner. When factors developed from carefully selected markers of the Big-Five factor structure were compared to those based on the total set of variables in each sample, the congruence between both types of factors was quite high. Attempts to extend the structure to 6 and 7 factors revealed no other broad factors beyond the Big Five in any of the 6 samples. These robust findings provide significant new evidence for the structure of teacher-based assessments of child personality attributes. [source] Nitrobenzene toxicity: QSAR correlations and mechanistic interpretations,JOURNAL OF PHYSICAL ORGANIC CHEMISTRY, Issue 10 2003Alan R. Katritzky Abstract The overall five-parameter QSAR correlation [ in terms of log(IGC50,1)] based on CODESSA-PRO methodology for the aquatic toxicity of 97 substituted nitrobenzenes to the ciliate Tetrahymena pyriformis supports previous conclusions that hydrophobicity and electrophilic reactivity control nitrobenzene toxicity. Correcting for the ionization of acidic species (picric and nitrobenzoic acids) improves the results: . Consideration of the total set of 97 compounds suggests two mechanisms of toxic action. A subset containing 43 compounds favorably disposed to reversible reduction of nitro group with respect to the single occupied molecular orbital energy, ESOMO correlated well with just four theoretically derived descriptors: . Another set of 49 substances predisposed to aromatic nucleophilic substitution modeled well () with five descriptors. Copyright © 2003 John Wiley & Sons, Ltd. [source] Detection of the OH band fine structure in liquid water by means of new treatment procedure based on the statistics of the fractional momentsLASER PHYSICS LETTERS, Issue 11 2007S.M. Pershin Abstract Three main spectral components ,3210, 3450, and 3650 cm,1 separated by deep gaps in the Raman OH band of liquid water have been detected by a new treatment procedure of experimental data. The applied treatment is based on the statistics of the fractional moments. This approach includes the consideration of the total set of the moments (the fractional and even complex ones) and the generalized mean value functions (GMV) as a specific noise "label". The possibility of the extraction and quantitative description of the fine structure of the averaging experimental spectra is demonstrated. In the frame of the novel approach the reliable separation between Raman spectra of the distilled and Milli-Q water is obtained. (© 2007 by Astro Ltd., Published exclusively by WILEY-VCH Verlag GmbH & Co. KGaA) [source] | |||||||||||||