Fotoquímica de ß-Carbolinas en soluciones orgánicas diluidas

In this work the photochemical behavior of full aromatic b-carbolines (nor-harmane, harmane, harmine and harmol) and two 3,4-dihydro b-carbolines (harmaline and harmalol) was studied. For the first time the UV absorption, emission and excitation spectra in organic solutions were described as well as on solid supports (silica gel, paper) and on powdered sample. The K of the complexation equilibrium between the full aromatic b-carbolines with alcohols forming a 1:2 adducts were measured and the pKa and pKa* in acetonitrile were determined by means of electronic absorption and fluorescence spectroscopy. Considering that these compounds are markedly fluorescent their behavior in the presence of CCl4 and other halomethanes (CH2Cl2, CHCl3, CH2BrCH2Br, CHBr3 and CBr4) which act as quenchers using either EtOH, iso-PrOH or MeCN as solvents was studied. We concluded that this quenching is dynamic and may take place through the formation of an exciplex followed by an electron transfer from the excited b-carboline to the halogenated compound starting the photochemical reaction. When a solution of either of these alkaloids (10-3 M) was irradiated in the presence of CCl4 in a protic organic solvent, the main product obtained, with more than 98% yield, was the hydrochloride. Besides, the gc-MS analysis showed traces of carboalcoxy and chloro-derivatives.%The feasibility of an exciton or a photon single electron transfer mechanism is discussed and parameters such as DGote, Ksv, kq, DG‡, DG‡(0), l, and E0ox were calculated using the Rehm-Weller, Marcus and Stern-Volmer models.%The quantum yield of photobleaching in different solvents was determined relative to the disappearance of harmane in EtOH-CCl4, which in turn was determined using potassium ferrioxalate as actinometer.Fil:Biondic, Miriana Carla. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina

Modeling Health Status Identification in a Gas Turbine System: Three-Class Classification Approaches

Rapid developments in sensor technology, data processing tools and data storage capability have helped fuel an increased appetite for equipment health monitoring in mechanical systems. As a result, the number of sensors and amount of data collected for health monitoring has grown tremendously. It is hoped that by collecting large quantities of operational data, predictive tools can be developed that will provide operational, maintenance and safety benefits. Data mining and machine learning techniques are important tools in addressing the ensuing challenge of extracting useful results from the data collected. In this work, the sensor data from a gas turbine system was analyzed with the objective of failure modeling and prediction. Previous efforts had used a two-class approach for this problem, to distinguish healthy and failed states of the system. In this work, a third class labelled as deteriorated data is added prior to each failure event to explore the ability of machine learning models to provide early warning of upcoming incidents. Several maintenance incidents were recorded by the sensor system in two separate vehicles. Three approaches to selecting training data were used. The first followed a traditional method of randomly selecting data points from all data according to a desired percentage of failed data to include in training, target ratios between failed and healthy data in each data set, as well as target ratios between training and testing data. The second data selection strategy was to consider data related to failure incidents as a whole and select certain incidents to include in training, and the remaining ones to be unseen in testing. The third approach was cross-validation which is typically used as a technique to evaluate how a classifier will perform on unseen data while still using the entirety of the data to train the final classifier. In addition to investigating training and data selection strategies, the effect of hyperparameter optimization was explored as well as the effect of varying the time period of the deteriorated class. Using the gas turbine data, which included 7 failure incidents and 76 predictor variables, a variety of classifier models of the system were developed in a three-class problem to differentiate healthy, deteriorated and failed system states. The classifier methods included support vector machines, Gaussian Naïve Bayes, random forest, adaboost, multilayer perceptron, k-nearest neighbor, and XG boost. Ensemble models were also created to leverage all the individual classifier models that were developed. This paper will describe the comprehensive results that were obtained using the various approaches and combinations, highlighting the respective benefits and limitations

Statistical analysis of childhood and early adolescent externalizing behaviors in a middle low income country

The article show the pattern of externalizing behavior across age, gender, school type, and school level, with reference to aggression, delinquency, and hyperactivity. The study samples were primary school pupils and secondary school students from three selected Local Government Areas (LGA) in Ogun State, Nigeria [Ado-Odo/Ota, Ifo, and Yewa South]. Their ages ranged from 10 to 20 years. The student/pupil sample was 1770 in all. The instrument used was an adapted version of Achenbach's child behavior checklist and youth self-report. Basic descriptive statistics like frequency, percentage, mean, standard deviation, as well as non-parametric statistics like Phi-coefficient, Chi-square, Goodman and Kruskal's gamma, Mann Whitney U test and Kruskal Wallis H test were utilized. Inferential parametric statistics like Pearson r, analysis of variance and simple regression were also utilized. Four major findings were reported. Firstly, the private schools irrespective of age, gender and level, scored higher than the public school in aggression, delinquency, and hyperactivity. Secondly, aggression is higher in secondary schools, while delinquency and hyperactivity are more prevalent in primary schools. Thirdly, school level and school type are the strongest predictors of externalizing behavior. Lastly, correspondence analysis showed a similar behavioral pattern for the three behaviors and three distinct behavioral patterns. i). Respondents aged 10 and below and those in primary schools (ii). Male, public and between 16 and 20. iii). Private, secondary, female and between 11 and 15. Implications of the study are discussed

Parenting Stress and Parenting Behaviors of Parents of Adolescents with Attention-Deficit/Hyperactivity Disorder (ADHD)

The goal of this dissertation was to examine the extent to which adolescent and parent characteristics predict parenting stress and parenting behaviors of mothers and fathers of adolescents with ADHD. Study 1 examined the relative contribution of parental ADHD and depression symptoms to the parenting stress of mothers and fathers of adolescents with ADHD. Study 2 examined the contribution of adolescent oppositional behavior, parental psychopathology, and parenting stress to the parenting practices of mothers and fathers of adolescents with ADHD and the extent to which, in intact families, negative parenting behaviors of one parent contribute to the parenting stress experienced by the co-parent. Method: The sample comprised 83 families with adolescents 13 to 18-years of age (48 with ADHD, 35 without ADHD). Parents provided ratings of parenting stress and their own ADHD and depression symptoms and parenting behaviors. Adolescents, their parents and teachers completed measures assessing adolescents’ inattention, hyperactivity-impulsivity and oppositional behaviors. Two aspects of parenting stress were investigated: Stress in relation to adolescent behaviors and parent-adolescent relationships (Adolescent-Focused Stress; AFS), and stress involving the impact of the adolescent on parental roles, relationships with others and sense of competence (Parent-Focused Stress; PFS). Positive (warmth and support, reasoning, and autonomy granting) and negative (coercive and permissive) parenting behaviors were investigated. Results: Mothers’ self-reported ADHD symptoms and impairment predicted their own parenting stress, and their co-parents’ PFS. Parental depression was associated with increased AFS and PFS for mothers and PFS for fathers. Parent-reported but not teacher-reported adolescent oppositional behaviors predicted parenting stress for both mothers and fathers, and parenting stress mediated the relationship between adolescent oppositional behavior and mothers’ and fathers’ parenting practices. Parenting stress also mediated the relationship between parental psychopathology and maternal positive and negative parenting and paternal negative parenting. Negative parenting in one parent predicted parenting stress in the co-parent. These findings support a developmental-transactional model that integrates child and parent factors that contribute to family functioning and highlight the role of parenting stress in understanding the relationship between adolescent oppositional defiant behaviors, parent ADHD and depression and parenting behavior among parents of adolescents with ADHD.Ph.D

Parenting Stress of Parents of Adolescents with Attention-deficit/Hyperactivity Disorder

This study examined parenting stress among parents of adolescents with ADHD. The sample comprised 45 adolescents (26 ADHD; 19 Comparison) age 13 to 18 and their parents. The Stress Index for Parents of Adolescents was completed by both mothers and fathers of participating youth. Parents of adolescents with ADHD reported more stress than parents of adolescents without ADHD. Mothers of adolescents with ADHD experience higher levels of stress in all areas. Fathers of adolescents with ADHD experience more total stress and more stress in the Adolescent and Adolescent-Parent Relationship domains. Maternal inattention and adolescent externalizing behaviour mediated the relationship between ADHD status and maternal parenting stress, and ADHD status and adolescent externalizing behaviour were found to predict paternal parenting stress. The results of this study provide strong support for the need to provide parents of adolescents with ADHD with interventions designed to reduce or help them cope with parenting stress.MAS

Housing reconstruction of war damaged towns and villages in Eastern Croatia

Paper presented at the XXXIII IAHS World Congress on Housing, 27-30 September 2005,"Transforming Housing Environments through Design", University of Pretoria.A rough estimate brings the total damage in the 1991/92 war in Eastern Croatia to nearly 24.000 dwellings (houses and flats). Many protected historical inner city cores as well as complete traditional villages suffered serious damages or were completely destroyed. If one can state that every region, not only in geographical but also in spiritual sense, corresponds with physical and spiritual sphere, begin realized and lasting through time, then we must conclude that this time element was by physical war destruction systematically removed from the towns and villages of Eastern Croatia. The main task of reconstruction therefore should have been in bringing back this time element by rebuilding those physical links with the past. This paper deals with reconstruction of these towns and villages where on one hand there was tendency to abandon the traditional model of a row-village and to replace it with buildings adopting models from models from another culture, completely strange to this particular region. In order to speed the return of the refugees the tendency continued after the war and the villages were rebuilt with off-the-peg houses of quite different character to the traditional one, modeled on different cultural model. The possibility of interpreting in a creative way the great qualities of traditional villages: ecological, economical, sociological and last but not least architectural qualities was lost in reconstruction. The reconstruction in the historical towns, besides complete reconstruction of the buildings in the very city cores in some examples, also shows a disrespect for the traditional way of life. Introducing housing models from another culture and other regions very rarely interpreting in a creative way the previous architectural identity of the area.Authors of papers in the proceedings and CD-ROM ceded copyright to the IAHS and UP. Authors furthermore declare that papers are their original work, not previously published and take responsibility for copyrighted excerpts from other works, included in their papers with due acknowledgment in the written manuscript. Furthermore, that papers describe genuine research or review work, contain no defamatory or unlawful statements and do not infringe the rights of others. The IAHS and UP may assign any or all of its rights and obligations under this agreement