Overt behavior problems and serotonergic function in middle childhood among male and female offspring of alcoholic fathers

A large body of literature indicates that the serotonergic system is involved in behavioral regulation, as evidenced by the inverse relationship between impulsive aggression and serotonergic function found in adult alcoholics and nonalcoholics. However, studies of this relationship among child and adolescent offspring of alcoholics (COAs) have not previously been done. This study examines the potentially parallel relationship between behavioral dysregulation and low serotonergic function in young COAs. The relationship is of potential interest as a phenotypic marker of biological vulnerability to aggressiveness, which itself has been hypothesized to be a risk factor for later antisocial alcoholism. The present work is part of an ongoing prospective study of the development of risk for alcohol abuse/dependence and other problematic outcomes in a sample of families subtyped by the fathers' alcoholism classification. We examined the relationship between overt behavior problems in middle childhood (mean age = 10.5 +/- 1.7 years) and whole blood serotonin (5-HT) in a subsample of the offspring (N = 32 boys and 12 girls). Using a Child Behavior Checklist (CBCL) index of behavioral undercontrol, we obtained results indicating that high total behavior problem (TBP) children had lower levels of whole blood 5-HT than did low-TBP children (p < 0.01). These results support the hypothesis that there is an inverse relationship between whole blood serotonin levels and behavior problems in young male and female COAs. A father's alcoholism status was not significantly related to his child's 5-HT level, i.e., the child's phenotypic expression of behavioral dysregulation was more reliably connected to serotonergic function than was paternal alcoholism.     

Dielectric and infrared study of some cellulose derivatives

Measurements of the dielectric constant of cotton cellulose, mercerized cellulose acetate, methyl cellulose, and carboxymethyl cellulose have been carried out in the temperature range of 0–70°C at different frequencies. The results showed that the values of the dielectric constant, with all cellulose derivatives at a given frequency, are greater than that of cotton cellulose and lower than that of mercerized cellulose. The variation of the dielectric constant with temperature showed a transition at 30–40°C with all the samples studied. These results, together with those from infrared spectra and specific volume measurements, indicated that the dielectric behavior depends greatly on the nature of the side group, the degree of hydrogen bonding between the different chains, and the micropores present in the fiber.     

am: A case study in AI methodology

Much artificial intelligence research is based on the construction of large impressive-looking programs, the theoretical content of which may not always be clearly stated. This is unproductive from the point of view of building a stable base for further research. We illustrate this problem by referring to Lenat's am program, in which the techniques employed are somewhat obscure in spite of the impressive performance.     

Reaction of cyanuric chloride and its derivatives with polyamide fibres in non-aqueous medium

Polyamide fibres (Nylon 6) were treated with cyanuric chloride in organic solvents (tetrachloroethylene and xylene) under different conditions. This treatment caused an increase in the fibre nitrogen content. The magnitude of the latter was dependent upon the cyanuric chloride concentration, the time and temperature of the treatment as well as the nature of solvent. For instance an extra nitrogen content of 0.08% was obtained at a cyanuric chloride concentration (based on wt. of fabric) of 25%. This contrasts with 0.46% at 100% concentration of cyanuric chloride. Similarly and extra nitrogen content of 0.08% was achieved at 50°C while at 121°C it amounted to 1.18%. However, the cyanuric chloride treated nuylon failed to link covalently to dyestuffs containing labile hydrogen, indicating no chemical reaction between polyamide 6 and cyanuric chloride. This chemical reaction could only be achieved by use of 2-anilino-4,6-dichloro-1,3,5-triazine instead of cyanuric chloride. Similarly a disperse dye containing a chlorotriazine ring as the reactive group was found to react chemically with polyamide 6.     

A model for conceptual processing of naturalistic scenes.

Reports on 3 experiments, with 251 undergraduates, that examine serial position effects for rapidly-presented naturalistic scenes. The experiments provide a basis for comparison with the U-shaped serial position curve and list-length effect that typically result from verbal learning experiments. In contrast to the U-shaped verbal serial position function, results show a flat function at the beginning serial positions and a recency effect that is small and limited to the last serial position. There is also a set-size effect. Results suggest that the processing leading to a memory representation for visual stimuli such as pictures and linguistic stimuli such as words is qualitatively dissimilar. The findings can be accounted for by a serial processing model whose main parameter is the probability that the subject will switch attention from one picture to the next. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The origin of the hydroxyl radical oxygen in the Fenton reaction

There is an ongoing discussion in the chemical literature regarding the nature of the highly reactive hydroxyl radical formed from the reaction between ferrous iron and hydrogen peroxide (the Fenton reaction). However, the fundamental experiment of directly determining the source of the hydroxyl radicals formed in the reaction has not yet been carried out. In this study, we have used both hydrogen peroxide and water labeled with 17O, together with ESR spin trapping, to detect the hydroxyl radicals formed in the reaction. ESR experiments were run in phosphate buffer with 5,5-dimethyl-1-pyrroline N-oxide (DMPO) as a spin trap, and either H2O2 or H2O labeled with 17O. The hydroxyl radical was generated by addition of Fe2+ ion to H2O2, or as a control, by photolysis of H2O2 in the ESR cavity. Observed ESR spectra were the sum of DMPO/.16OH and DMPO/.17OH radical adduct spectra. Within experimental accuracy, the percentage of 17O-labeled hydroxyl radical trapped by the DMPO was the same as in the original hydrogen peroxide, for either method of hydroxyl radical generation, indicating that the trapped hydroxyl radical was derived exclusively from hydrogen peroxide and that there was no exchange of oxygen atoms between H2O2 and solvent water. Likewise, the complementary reaction with ordinary H2O2 and 17O-labeled water also showed that none of the hydroxyl radical was derived from water. Our results do not preclude the ferryl intermediate, [Fe = O]2+ reacting with DMPO to form DMPO/.OH if the ferryl oxygen is derived from H2O2 rather than from a water ligand.     

Vinyl chloride-ethylene copolymers: The effect of modest ethylene concentrations on the physical properties of compounds

Vinyl chloride-ethylene copolymers containing from 1.0 to 5.5 wt.% ethylene were synthesized and compounded with DOP plasticizer at levels of 0, 5, 10, 20, 30, and 40 parts per hundred parts of resin. Physical property tests indicated that, as an internal plasticizer, ethylene was 2 to 3 times more efficient than DOP in the range studied. An examination of room temperature modulus as well as brittleness also indicated that crystallinity was still apparent in all copolymers.