Polymerization of olefins and polar monomers catalyzed by bis(imino)Ni(II)/dibutylmagnesium/alkylaluminium halide systems

[Bis(N,N′‐dimesitylimino)acenaphthene]dibromonickel ( 1 ) when activated with diethylaluminium chloride (DEAC) is a very active catalyst for ethylene homopolymerization. The activity (A_E) of 1 /100 DEAC is twenty times greater than that of 1 /100 MAO and of the same order of magnitude as 1 /2000 MAO. In the case of homopolymerization of propylene the highest activity (A_P) was obtained at a ratio of 25/15 for Al_DEAC/Ni. Trialkylaluminium compounds were also found to act as cocatalysts for 1 . The PE synthesized with four different cocatalysts was found by ¹³C NMR to have dissimilar branching distributions. 1 /DEAC shows no activity for the polymerization of proximately substituted polar monomers. The introduction of dibutylmagnesium, (DBM) activates the 1 /DEAC system to copolymerize ethylene and a number of proximately substituted polar monomers. Compared with the 1 /MAO/monomer.AlR₃ catalyst system the former is three times more active for copolymerization of 5‐hexene‐1‐ol or 10‐undecen‐1‐oic acid with ethylene. The activity of copolymerization is 1 /24, 1 /5 and 1 /2 as active as homopolymerization, respectively, in the case of methyl vinyl ketone, vinyl acetate and ?‐caprolactam. In the case of tetrahydrofuran/ethylene, the 1 /MAO catalyst produced copolymers using AlR₃ pretreated THF whereas the 1 /DEAC/DBM catalyst produces homopolyethylene only. No polymerization occurred with an acrylonitrile/ethylene mixture in the presence of 1 /DBM/DEAC catalyst. © 2002 Society of Chemical Industry     

Influence of subject and experimenter sex in psychological research.

Reports that a survey of recent volumes of 2 american psychological association journals indicates that psychologists frequently neglect sex of e and s in designing, analyzing, and reporting studies. Close examination of the influence of sex in the areas of schizophrenia, psychological testing, and sexual attitudes and behaviors suggested that sex of e and s can influence results of research. This variable should be explicitly considered when designing experiments, and neglected only when its contribution can be ruled out empirically. Appropriate controls include use of both male and female ss and a broad sampling of a male and female e population to insure generality of results. (35 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Theory and measurement of androgyny: A reply to the Pedhazur-Tetenbaum and Locksley-Colten critiques.

Discusses issues raised in the critiques of E. J. Pedhazur and T. J. Tetenbaum (see record 1980-29271-001) and of A. Locksley and M. Colten (see record 1980-30293-001). It is noted that (a) the Bem Sex-Role Inventory (BSRI) is based on a theory about both the cognitive processing and the motivational dynamics of sex-typed and androgynous individuals; (b) the strategy of item selection for the BSRI followed directly from the theory and utilized established techniques for test construction; (c) a short BSRI has been developed in accordance with the results of various factor analyses; (d) current research is testing the hypothesis that sex-typed and androgynous individuals differ in the extent to which gender serves as a cognitive schema; and (e) the concept of androgyny contains an inner contradiction and hence a built-in obsolescence. (34 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Long-Term Neuroelectric Signal Recording from Severed Nerves

Six recording electrode units were implanted around the severed sciatic nerves of rabbits immediately after an axotomy was performed. Voluntary and involuntary motor neuroelectric signals (including individual action potentials) were recorded from the surface of the severed nerve for as long as 142 days after implantation, the average duration being 64 days. In order to study the course of the limited duration of the signal detection, a stimulation electrode was implanted around the sciatic nerve proximal to the lesion; evoked neuroelectric signals were recorded throughout the length of the experiment. The impedance of the recording electrode was also measured throughout the length of the experiment. The behavior of the above parameters, combined with histological observations, indicated that nerve degeneration accounted for the deterioration of signal detection.     

A computer assisted scheduling system for retail organizations

A knowledge-based system is developed to produce work schedules for personnel in large retail settings. The system considers part- and full-time employment, specific and general assignments, minimum and maximum hours per work period and per week, absences due to vacation and illness, and other constraints. The major objective is to schedule employees in relation to sales activity over the year without exceeding a certain budgetary allocation for sales labor. This allocation is defined as a percentage of sales.

The system is developed in Arity/Prolog and includes a forecasting module which forecasts sales by week on the basis of the previous three years of data and activity by hour and day on the basis of several weeks of aggregated data. Schedules are produced for periods of one week but the user may override the schedule as circumstances warrant.     

Nutrition and women's health: position of the American Dietetic Association and Dietitians of Canada.

It is the position of the American Dietetic Association (ADA) and Dietitians of Canada (DC) that women have specific nutritional needs and vulnerabilities and, as such, are at unique risk for various nutrition-related diseases and conditions that affect the duration and quality of their lives. Although women's health-related issues are multifaceted, nutrition has been shown to influence significantly the risk of chronic disease and assist in maintaining optimal health status. Therefore, the ADA and DC encourage dietetics professionals to strongly support research, health promotion activities, health care services, and advocacy efforts that will enable women to adopt desirable nutrition practices for optimal health.     

Field and Laboratory Evaluation of the Impact of Tall Fescue on Polyaromatic Hydrocarbon Degradation in an Aged Creosote-Contaminated Surface Soil

A field study was initiated in 1997 to assess the ability of tall fescue grass to remediate an aged creosote-contaminated surface soil. Field monitoring was combined with aerobic microcosm experiments, microbial enumerations, and plant tissue analysis to determine the impact of tall fescue on the degradation of six polycyclic aromatic hydrocarbons (PAHs), acenaphthene, fluorene, phenanthrene, fluoranthene, pyrene, and chrysene, and to elucidate the mechanisms of remediation. Fescue grass had a beneficial impact on the degradation of all PAHs except phenanthrene. Mean concentrations of the three-ring PAHs, acenaphthene and fluorene, were lower in fescue cells compared to unvegetated cells after 36 months. In microcosms with soil from fescue cells, acenaphthene had a significantly higher degradation rate and lower final concentration after 180 days than in microcosms prepared with soil from unvegetated cells. Mean concentrations of the four-ring PAHs, fluoranthene, pyrene, and chrysene, were statistically similar in the field study; however, the 10th and 20th percentile concentrations were lower in fescue cells during all sampling periods. Microcosm studies showed increased degradation of fluoranthene and pyrene in soil samples taken from tall fescue rhizosphere compared to unvegetated soil and abiotic controls. Degradation of four-ring PAHs was enhanced in the shallow zones (10–15 cm below ground surface) of vegetated cells. The root mass was approximately 35% greater in shallow zones than in medium depth zones (15–21 cm below ground surface). Microbial populations on solid mineral media plates with pyrene and chrysene as the sole carbon source were two times higher in soils from tall fescue plots than from unvegetated soils, suggesting that the increased PAH degradation was a result of increased microbial activity in the rhizosphere. Gas chromatography/mass spectrometry analysis of fescue shoots indicated that no uptake or translocation of PAHs or PAH degradation intermediates into the shoots was occurring.     

Structural and morphological changes in Poly(caprolactone)/poly(vinyl chloride) blends caused by UV irradiation

Films made from a blend of poly(ε-caprolactone) and poly(vinyl chloride) (PCL/PVC) retained high crystallinity in a segregated PCL phase. Structural and morphological changes produced when the films were exposed to high potency ultraviolet (UV) irradiation for 10 h were measured by UV-Vis spectroscopy (UV-Vis), Fourier Transform Infrared Spectroscopy (FTIR), and Scanning Electron Microscopy (SEM). They were different to those observed with homopolymer PCL and PVC films treated under the same conditions. The FTIR spectra of the PCL/PVC blend suggest that blending decreased the susceptibility of the PCL to crystallize when irradiated. Similarly, although scanning electron micrographs of PCL showed evidence of growth of crystalline domains, particularly after UV irradiation, the images of PCL/PVC were fairly featureless. It is apparent that the degradation behavior is strongly influenced by the interaction of the two polymers in the amorphous phase.     

Dispositional resistance to change: Measurement equivalence and the link to personal values across 17 nations.

The concept of dispositional resistance to change has been introduced in a series of exploratory and confirmatory analyses through which the validity of the Resistance to Change (RTC) Scale has been established (S. Oreg, 2003). However, the vast majority of participants with whom the scale was validated were from the United States. The purpose of the present work was to examine the meaningfulness of the construct and the validity of the scale across nations. Measurement equivalence analyses of data from 17 countries, representing 13 languages and 4 continents, confirmed the cross-national validity of the scale. Equivalent patterns of relationships between personal values and RTC across samples extend the nomological net of the construct and provide further evidence that dispositional resistance to change holds equivalent meanings across nations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Correction to Emery, Hale, and Myerson (2008).

Reports an error in "Age differences in proactive interference, working memory, and abstract reasoning" by Lisa Emery, Sandra Hale and Joel Myerson (Psychology and Aging, 2008[Sep], Vol 23[3], 634-645). The original article contained an incorrect DOI. The correct DOI is as follows: 10.1037/a0012577. (The following abstract of the original article appeared in record 2008-13050-014.) It has been hypothesized that older adults are especially susceptible to proactive interference (PI) and that this may contribute to age differences in working memory performance. In young adults, individual differences in PI affect both working memory and reasoning ability, but the relations between PI, working memory, and reasoning in older adults have not been examined. In the current study, young, old, and very old adults performed a modified operation span task that induced several cycles of PI buildup and release as well as two tests of abstract reasoning ability. Age differences in working memory scores increased as PI built up, consistent with the hypothesis that older adults are more susceptible to PI, but both young and older adults showed complete release from PI. Young adults' reasoning ability was best predicted by working memory performance under high PI conditions, replicating M. Bunting (2006). In contrast, older adults' reasoning ability was best predicted by their working memory performance under low PI conditions, thereby raising questions regarding the general role of susceptibility to PI in differences in higher cognitive function among older adults. (PsycINFO Database Record (c) 2010 APA, all rights reserved)