Atmospheric DMSO degradation in the gas phase: Cl-DMSO reaction. Temperature dependence and products

The reactions of Cl atoms and ClO radicals with CH3-SOCH3 (DMSO) have been studied using the discharge flow method with direct detection of DMSO, CO, and products by mass spectrometry. The absolute rate constant at room temperature measured for reaction 1, (CH3)2SO + Cl --> products, was k(1) = (1.7 +/- 0.3) x 10(-11) cm3 molecule(-1) s(-1). For reaction 2, (CH3)2SO + ClO --> products, only an upper limit could be established, k(2) < or = 6 x 10(-14) cm3 molecule(-1) s(-1) Reaction 1 has been found to proceed through adduct formation and further decomposition involving the cleavage of the C-S bound. The pressure effect on the Cl-DMSO reaction from 0.5 to 3 Torr was negligible, and the temperature dependence in the range 273-335 K was also very slight. The results obtained are related to previous studies of sulfur compounds, and the atmospheric implications are also discussed in relation to the homogeneous sinks of DMSO. Tropospheric lifetimes of DMSO based on average Cl and ClO concentrations and the measured rate constants have been calculated showing that the contribution of reaction 1 must be of minor relevance in the marine boundary layer. Reaction 2 is so slow that it does not play any role within the atmospheric sulfur chemistry.     

Compared Analysis of Metro Networks Supported by Graph Theory

This paper brings into focus the topological and geographical evaluation of metro networks through the definition of a methodological approach based on a set of indicators, a lot of which are defined in the sector literature. Once the methodology was stated, the results of an application on the metro networks of 13 big metropolitan areas were illustrated. Statistical comparative analyses are proposed to classify networks.     

Deficits on the continuous performance test within the schizophrenia spectrum and the mediating effects of family history of schizophrenia.

Individuals with schizophrenia spectrum personality disorders (SSPD) and schizophrenia show similar cognitive impairments. The authors examined the contributions of SSPD symptoms and familial risk for schizophrenia to impairments on the Continuous Performance Test-Identical Pairs Version. Participants included 103 schizophrenia patients, 66 first-degree relatives (29 SSPD), and 103 community controls (26 SSPD) screened for family history of psychosis. Patients and SSPD relatives performed significantly worse than non-SSPD relatives and SSPD and non-SSPD community controls. No differences in performance were observed among non-SSPD relatives and SSPD and non-SSPD community controls. Results suggest a continuum in which risk for schizophrenia-related cognitive impairments is highest among patients and SSPD relatives, intermediate among non-SSPD relatives, and lowest among SSPD and non-SSPD community controls. Results suggest that SSPD in the absence of a family history of psychosis may be a phenocopy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The Connectionist Inductive Learning and Logic Programming System

This paper presents the Connectionist Inductive Learning and Logic Programming System (C-IL²P). C-IL²P is a new massively parallel computational model based on a feedforward Artificial Neural Network that integrates inductive learning from examples and background knowledge, with deductive learning from Logic Programming. Starting with the background knowledge represented by a propositional logic program, a translation algorithm is applied generating a neural network that can be trained with examples. The results obtained with this refined network can be explained by extracting a revised logic program from it. Moreover, the neural network computes the stable model of the logic program inserted in it as background knowledge, or learned with the examples, thus functioning as a parallel system for Logic Programming. We have successfully applied C-IL²P to two real-world problems of computational biology, specifically DNA sequence analyses. Comparisons with the results obtained by some of the main neural, symbolic, and hybrid inductive learning systems, using the same domain knowledge, show the effectiveness of C-IL²P.     

Chemical and microbiological quality of grass carp (Ctenopharyngodon idella) slaughtered by different methods

The effect of two slaughter methods (immersion in ice-water slurry and electrical stunning followed by ice slurry asphyxiation) on chemical and microbiological parameters of grass carp (Ctenopharyngodon idella) stored in ice for 20 days was evaluated. No differences in total volatile basic nitrogen (TVB-N), pH, carbohydrate or protein content of mucus were observed between the slaughter methods. Ice-slaughtered fish had lower bacteria counts at the beginning of storage, but higher counts than fish slaughtered by electricity at the end of storage (p < 0.05). However, no significant differences in the shelf life were observed between the slaughter methods evaluated (limit of acceptability – counts > 3 × 10⁶ CFU g⁻¹ – attained after 13–16 days). Results indicated that the chemical parameters evaluated have a limited applicability to assess the shelf life of grass carp stored in ice, since pH limit (6.8) was exceeded after 4 days, while TVB-N limit (30 mg%) was not attained after 20 days of storage.     

Identification of genes expressed in the rat prostate that are modulated differently by castration and Finasteride treatment

In mammals, testosterone and 5alpha-dihydrotestosterone (DHT) are the principal male hormones (androgens). Testosterone is the most abundant circulating androgen, and is converted in specific tissues to DHT by the 5alpha-reductase enzymes. Although each of these androgens binds to the same receptor protein (androgen receptor, AR), each exerts biologically distinct effects. Theories to explain the specific effects of testosterone and DHT have centered on kinetic differences of binding of androgens to the receptor or differences in the metabolic fates of the two hormones. In the current experiments, differential display PCR (ddPCR) was used to identify genes regulated differently by testosterone and DHT. Adult male rats were treated as follows: castrated, treated with Finasteride (an inhibitor of 5alpha-reductase) or left intact for ten days. RNA was prepared from the dissected prostates of these animals and used for ddPCR. Genes exhibiting four distinct patterns of regulation were observed among the mRNAs. Class 1 genes showed equivalent expression in intact and Finasteride-treated animals, but were absent in castrated animals (mRNAs D1, D2, D6, D10). Class 2 genes showed higher expression in intact animals, intermediate levels following Finasteride treatment, but were absent in castrated animals (mRNA D8). Two classes of gene were particularly intriguing: class 3 showed gene expression only in the intact animal (mRNA D7, D9) and class 4 showed increased gene expression following Finasteride treatment (mRNA D3). While the patterns observed for some of these genes (e.g. D8) suggest that the different biological effects of testosterone and DHT may be due to the lower affinity of the AR for testosterone and limiting tissue concentrations of androgen, our results also suggest that some genes expressed in the rat prostate may be regulated in fundamentally different ways in response to testosterone and DHT.     

A group measure of the Piagetian concepts of conservation and egocentricity.

Presents a group test of Piagetian tasks. 30 male and 30 female 1st graders were tested using both group and individual procedures. A correlation was obtained across the 2 methods of assessment. Properties of the test were examined for internal and conceptual consistency. 2 scales employing a cartoon format were examined, each consisting of 6 items drawn from various clinical test situations described by Piaget. Scale I, conservation of substance, was shown to possess high internal consistency and a high degree of correspondence across the 2 methods of presentation. Scale II, egocentricity, was shown to possess poorer scale properties which are suggestive of a need for further refinement. (French summary) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect on learning of postinstructional responses to questions of differing degrees of complexity.

Investigated the effect on the learning of science subject content of having students respond to questions of different degrees of complexity following segments of instruction. The study involved 193 7th-grade students in 5 groups. Questions of differing degrees of complexity were interspersed every 20th frame of the programmed instruction material for 3 treatment groups. The 4th treatment group read a paragraph related to the questions. The 5th group acted as a control. The groups that completed the instructional materials and responded to the interspersed questions scored significantly higher than the group that completed the instructional materials and did not respond to questions. (28 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)