Simulation of complex molecules—Computational requirements for the 1980''s

Improving the understanding of complex molecular systems is an important and interesting use of supercomputers. Computer simulation currently plays, and will continue to play, a vital role in research in this area by acting as a guide to site-specific mutagenesis. This study explains simulations of complex molecules.     

Conversion of Polycrystalline Alumina to Single-Crystal Sapphire by Localized Codoping with Silica

The effect of a localized SiO₂ codoping on the conversion of polycrystalline, MgO-doped Al₂O₃ tubes to single-crystal sapphire was investigated. Codoping with SiO₂ before sintering intentionally triggered abnormal grain growth, which resulted in the full conversion of tube surfaces to single crystal without adversely affecting densification to a almost pore-free, translucent state. The degree of surface conversion was strongly dependent on experimental variables, which included furnace temperature and codoping amount. Surface-converted tubes had excellent physical properties, which included good thermal cycling resistance and optical properties superior to unconverted, polycrystalline Al₂O₃.     

Depression and memory impairment: A meta-analysis of the association, its pattern, and specificity.

The existing evidence paints an unclear picture of whether an association exists between depression and memory impairment. The purpose of this investigation was to determine whether depression is associated with memory impairment, whether moderator variables determine the extent of this association, and whether any obtained association is unique to depression. Meta-analytic techniques were used to synthesize data from 99 studies on recall and 48 studies on recognition in clinically depressed and nondepressed samples. Associations between memory impairment and other psychiatric disorders (e.g., schizophrenia, dementia) were also examined. A significant, stable association between depression and memory impairment was revealed. Further analyses indicated, however, that it is likely that depression is linked to particular aspects of memory, the linkage is found in particular subsets of depressed individuals, and memory impairment is not unique to depression. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Postmortem distribution of nicotine and cotinine from a case involving the simultaneous administration of multiple nicotine transdermal systems

A 31-year-old female was found dead with 18 nicotine transdermal system patches taped to her upper body and a plastic bag taped over her nose and mouth (the cause of death was ruled asphyxiation). Nicotine concentrations in biological fluids and tissues were analyzed using a liquid-liquid extraction followed by injection onto and HP-5890 gas chromatograph (GC) equipped with a nitrogen-phosphorus detector. Cotinine was separated from the biological matrices using solid-phase extraction followed by analysis on an HP-5890 GC with flame ionization detection. A variety of specimens were analyzed, including blood, urine, vitreous, brain, liver, and gastric contents. Heart and femoral blood concentrations (1.4 and 0.46 micrograms/mL, respectively) were 175 and 57 times, respectively, the mean C(max) value reported following the proper administration of a single 7-mg/day patch.     

Printing flax/polyester blends—a new approach

Work at the University of Ulster has been carried out to investigate methods of achieving startling print colour effects. It has been realised that by arranging fibre blends and distribution, pleasing aesthetic results are made possible. In this article Brian Hill and George Gray give a brief account of their research.     

Reconsidering the sauce: A comment on Floyd.

Comments on the article Fundamentalism: Sauce for the goose by K. Floyd (see record 2007-09680-001). Floyd reminds us that the application of a little logic to the propositions we claim are true can sometimes show us that our beliefs are untenable, and that such a finding "could turn out to be very freeing indeed". In particular, he uses one of the arguments some of us struggled with the first time we met logic as a discipline: If P is true then Q is true. Q isn't true. Therefore, P isn't true. Floyd applies this principle to religious belief: If I believe that P is true and Q is true when in fact P implies that 0 is false then I am truly inconsistent! He also shows how easily we are willing to use such logic on the beliefs of others but not on our own beliefs. The current authors' attempt to demonstrate that Floyd makes several questionable steps in his reasoning, thereby calling into question the conclusions he draws. Floyd has sought to point out the lack of thought behind numerous religious beliefs. The current authors accept this general observation, but they believe it unfair to attribute this difficulty only to religious beliefs. The difficulty with religious beliefs is not that they are not concerned with truth vs. non-truth, but rather that for a number of reasons, the difference between these two poles is often not obvious. The question of the validity of religious beliefs is a philosophically spiny one that has been addressed, sometimes adequately and sometimes in very illogical, emotional and violent fashions, for thousands of years. It seems obvious to the authors that "three minutes thought" is not sufficient to untangle such an issue. (PsycINFO Database Record (c) 2010 APA, all rights reserved)