Demand characteristics in a field experiment.

Hypothesized that groups receiving a favorable leadership change would improve their performance while groups receiving negative leadership changes would deteriorate. Several foremen in a manufacturing organization were interchanged among groups through regular administrative channels, on short notice, and under deceptive conditions that hid the true purpose of the leadership changes. 10 wk. later a research team intervened to administer a questionnaire for assessment purposes. The contents of the questionnaire and the conditions under which it was administered clearly revealed the true purpose of the original foreman reassignments. The hypothesis, which was hidden during the "deception" period, was not supported until the workers learned the real reason for the experiment. They then supported the hypothesis, but only for 2 wk., indicating that the way in which the experimental variable is introduced in a study like this is a potentially critical matter. (14 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

New format for flowcharts

This paper proposes a new chart format as an alternative for the flow diagram variety of flowchart. This new chart format is more informative, more compact and easier to use and draw than the ANS format, and facilitates modularization in design and programming. The new chart format supports restrictions on control transfers, and clearly identifies the control structures used in structured programming. The new chart format also permits showing multiple levels of detail unambiguously in a single flowchart, and enables HIPO charts and system charts to be usefully augmented.     

A comparison of calculated NMR shielding probes

In a strong magnetic field, covalently bonded hydrogen nuclei located over the plane of an anisotropic pi bond-containing functional group experience magnetic shielding (or deshielding) that results from the combined effect of the magnetic anisotropy of the functional group and other nearby covalent bonds plus other intramolecular shielding effects. These effects can now be calculated with reasonable accuracy using ab initio methods. We have investigated several computational probes of the magnetic shielding surface near anisotropic functional groups and compared the results to previous reports of experimental observations in example structures. GIAO-HF in Gaussian 03 was employed to calculate isotropic shielding values and to predict the net NMR shielding increment for several computational probes: methane, diatomic hydrogen, a hydrogen atom, a helium atom, or a ghost atom, each held in various positions over simple test molecules (ethene, ethyne, benzene and HCN) that contain the functional groups studied. Also, the effect of performing single point calculations versus constrained geometry-optimized calculations was examined. In addition, the effect of the angle of the orientation of the probe molecule (in the case of CH(4) and H(2)) relative to the pi bond in the test molecule was studied. Finally, the atomic charges in the molecular probes (CH(4) and H(2)) were computed to investigate the nature of the interaction of the probe with the test molecule. The optimal, most economical computational results were obtained using single point calculations of a diatomic hydrogen probe oriented perpendicular to the surface (or axis) of the test molecule.     

Sleep debt,sleepiness and accidents among males in the general population and male professional drivers

Men from the general population and male professional lorry and bus drivers were surveyed with regard to sleep habits and motor vehicle and other types of accidents. A random sample of 4000 men in the general population of Dalarna County in mid-Sweden were mailed a questionnaire and served as referents. A total of 1389 male professional lorry and bus drivers from this county responded to the same questionnaire. A total of 161 of the drivers also underwent a sleep study in their homes.The proportion of total accidents was higher among the professional drivers as compared with the males in the population, P=0.03. Reports on traffic accidents were the same in both groups, but the professional drivers reported more accidents at leisure compared with referents, P<0.0001. Accidents of any kind, traffic accidents included, among those affected by both snoring and apneas, were not reported more in either of the groups. At the sleep study, 17% of those examined received the diagnosis of obstructive sleep-apnea syndrome (OSAS).The professional drivers reported proportionally more sleep debt than the referents, P<0.001. Among referents, traffic accidents at leisure, traffic accidents while commuting and accidents at work increased in proportion to sleep debt (P<0.001, 0.006 and 0.002, respectively). The finding that self-perceived sleep debt may have an adverse effect on males in the general population and male professional drivers concerning accident likelihood should have an impact on prevention. These results stress the need to educate the general population on the importance of complying with our biological need of sleep.     

Family background characteristics and relationship satisfaction in a native community in Canada

Using data collected from a Native Canadian community by Embree (1993), we examine the influence of personal and family background characteristics on satisfaction with spousal relationships, both legal marriages and cohabitations. Of special interest are the quality of relationships with parents while growing up, alcohol abuse by the parent(s), and the experience of sexual abuse during childhood. Personal traits such as age, sex, and gender role attitudes and the respondent's own drinking behavior are also considered. Path analytic techniques model both the direct effects of independent variables on relationship satisfaction as well as the role of personal consumption of alcohol as an intervening variable in level of satisfaction with a relationship. The results of the analysis indicate that personal consumption of alcohol and the experience of sexual abuse during childhood are the best direct predictors of level of satisfaction with the current relationship, with higher alcohol consumption and experience of sexual abuse related to lower satisfaction. Age also has a significant direct, though smaller, positive influence on relationship satisfaction. Sexual abuse and the respondent's sex are also linked to level of satisfaction through personal alcohol consumption. With personal alcohol use, both the respondent's sex and the experience of sexual abuse during childhood have a significant effect, with males and those sexually abused as children reporting higher levels of alcohol consumption. The socialization explanation of the intergenerational consequences of parental behavior argues that parental role models are primary to the future family formation behavior of children. Consistent with this hypothesis, the findings concerning sexual abuse, in particular, as a predictor of both personal alcohol use and relationship satisfaction seem to underscore the importance of antecedent family characteristics in influencing later adjustment to adult roles and responsibilities.     

Transient inhibition of CD28 and CD40 ligand interactions prolongs adenovirus-mediated transgene expression in the lung and facilitates expression after secondary vector administration

Recombinant adenovirus vectors have been used to transfer genes to the lungs in animal models, but the extent and duration of primary transgene expression and the ability to achieve expression after repeated vector administration have been limited by the development of antigen-specific immunity to the vector and, in some cases, to vector-transduced foreign proteins. To determine if focused modulation of the immune response could overcome some of these limitations, costimulatory interactions between T cells and B cells/antigen-presenting cells were transiently blocked around the time of vector administration. Systemic treatment at the time of primary-vector administration with a monoclonal antibody (MR1) against murine CD40 ligand, combined with recombinant murine CTLA4Ig and intratracheal coadministration of an adenovirus vector transducing the expression of murine CTLA4Ig, prolonged adenovirus-transduced beta-galactosidase expression in the airways for up to 28 days and resulted in persistent alveolar expression for >90 days (the duration of the experiment). Consistent with these results, this treatment regimen reduced local inflammation and markedly reduced the T-cell and T-cell-dependent antibody response to the vector. A secondary adenovirus vector, administered >90 days after the last systemic dose of MR1 and muCTLA4Ig, resulted in alkaline phosphatase expression at levels comparable to those seen with primary-vector administration. Expression of the secondary transgene persisted in the alveoli (but not in the airways) for up to 24 days (the longest period of observation) at levels similar to those observed on days 3 to 4. These results indicate that transient inhibition of costimulatory molecule interactions substantially enhanced gene transfer to the alveoli but was much less effective in the airways. This suggests that there are differences in the efficiency or nature of mechanisms limiting transgene expression in the airways and in the alveoli.     

Examination of the validity of the Adolescent Problems Inventory among incarcerated juvenile delinquents.

Investigated the validity of the B. J. Freedman et al (see record 1979-26248-001) Adolescent Problems Inventory (API), a measure of social competence in situations related to antisocial behavior in adolescence, in 60 incarcerated male 14–18 yr olds. Criterion variables included historical and current behavioral indices of antisocial and disruptive behavior. Statistical analyses revealed no significant relationships in the expected direction between the API and the criteria in either the full sample or in the Black or White subsamples. Results challenge the validity of the API, and recommendations for a more refined assessment of social skills in juvenile delinquents are made. (5 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Free radical oxidation of polyunsaturated lipids: New mechanistic insights and the development of peroxyl radical clocks

The peroxidation of lipids in biological membranes has been implicated in both the onset and development of most degenerative diseases. The primary products of this autoxidation process are usually lipid hydroperoxides. They form as a consequence of a free radical chain reaction: lipid peroxyl radicals propagate the chain by rate-limiting H-atom abstraction from another lipid. Studies of the mechanism of lipid peroxidation are a specific part of a wider effort to understand the more general phenomenon of hydrocarbon autoxidation, which dates back some 70 years. However, the autoxidation of lipids is generally much more complicated than that of other hydrocarbons because of additional reaction pathways afforded by a variety of uniquely positioned unsaturated bonds. Indeed, polyunsaturation is an important aspect of many of the most relevant of physiological lipids, such as linoleate and arachidonate. In this Account, we present our current understanding of the mechanism of unsaturated lipid peroxidation, effectively updating our Account on the same topic published 25 years ago. Our more recent work has, in large part, been stimulated by the discovery of the nonconjugated linoleate hydroperoxide as a product under certain autoxidation conditions. The identification of this long-elusive bis-allylic hydroperoxide prompted our kinetic characterization of the reaction leading to its formation. The product distributions obtained from autoxidations of newly synthesized model compounds, which vary in either the substitution of the bis-allylic moiety or the configuration of the double bonds, have provided key insights into the overall mechanism. These insights have in turn been reinforced by the results of theoretical calculations. The picture that emerges is one wherein the delocalized carbon-centered radicals, which arise as intermediates in these reactions, first associate with dioxygen to form pre-reaction complexes. These complexes then collapse through transition state structures that maximize the orbital interactions between the delocalized radical SOMO and dioxygen. The energies of these transition states are influenced by steric effects; thus, there are distinct changes in product distribution in the autoxidation of dienes having different substitution patterns. The radical-dioxygen complexes are also intermediates in the isomerization of allylperoxyl and pentadienylperoxyls, helping explain the high regio- and stereochemical fidelity of these processes. We have taken advantage of the rapid fragmentation of nonconjugated peroxyl radicals to develop a powerful peroxyl radical clock methodology, which can be used to determine rate constants for reactions of peroxyl radicals with molecules having rate constants ranging from 1 to 10(7) M(-1) s(-1). We can make use of this methodology to address various questions, both fundamental and applied, relating to lipid peroxidation and its inhibition by radical-trapping antioxidants.