Investigation of the association between all-trans-retinol dehydrogenase (RDH8) polymorphisms and high myopia in Chinese

Retinoic acid level in the retina/choroid is altered in induced myopia models. All-trans-retinol dehydrogenase (RDH8) is an important enzyme of retinoic acid metabolism. This study aimed to investigate the association of the RDH8 gene with high myopia. Three single nucleotide polymorphisms (SNPs) [RDH851 (rs2233789), RDH8E5a (rs1644731), and RDH855b (rs3760753)] were selected, based on the linkage disequilibrium pattern of RDH8 from a previous study, and genotyped for 160 Han Chinese nuclear families with highly myopic (−10 diopters or worse) offspring as well as in an independent group with 166 highly myopic cases (−10 diopters or worse) and 211 controls. Family-based association analysis was performed using the family-based association test (FBAT) package, and genotype relative risk (GRR) was calculated using the GenAssoc program. Population-based association analysis was performed using Chi-square test. These SNPs were in linkage equilibrium with each other. SNPs RDH851 (rs2233789) and RDH8E5a (rs1644731) both did not show association with high myopia. SNP RDH855b (rs3760753) demonstrated significant association (P=0.0269) with a GRR of 0.543 (95% confidence interval=0.304–0.968, P=0.038). The association became statistically insignificant, however, after multiple comparison correction. Haplotype analysis did not show a significant association either. Population-based association analysis also showed no significant association (P>0.05). Our family- and population-based data both suggest that the RDH8 gene is unlikely to be associated with high myopia in Chinese.     

A novel surface modification technique for forming porous polymer monoliths in poly(dimethylsiloxane)

A new method of surface modification is described for enabling the in situ formation of homogenous porous polymer monoliths (PPMs) within poly(dimethylsiloxane) (PDMS) microfluidic channels that uses 365 nm UV illumination for polymerization. Porous polymer monolith formation in PDMS can be challenging because PDMS readily absorbs the monomers and solvents, changing the final monolith morphology, and because PDMS absorbs oxygen, which inhibits free-radical polymerization. The new approach is based on sequentially absorbing a non-hydrogen-abstracting photoinitiator and the monomers methyl methacrylate and ethylene diacrylate within the walls of the microchannel, and then polymerizing the surface treatment polymer within the PDMS, entangled with it but not covalently bound. Four different monolith compositions were tested, all of which yielded monoliths that were securely anchored and could withstand pressures exceeding the bonding strength of PDMS (40 psi) without dislodging. One was a recipe that was optimized to give a larger average pore size, required for low back pressure. This monolith was used to concentrate and subsequently mechanical lyse B lymphocytes.     

Physical and psychomotor performance of Australian football and rugby league officials during a match simulation

The onset of exercise facilitates an improvement in psychomotor performance until the second ventilatory threshold, after which performance is reduced. This inverted-U relationship appears valid for incremental and steady-state exercise, however, not for intermittent exercise. This study examined changes in psychomotor performance of team sport officials during a laboratory-based match simulation. Twelve elite Australian football (n = 5) and rugby league (n = 7) officials (32.5 ± 5.5 years; 180.0 ± 6.8 cm; 78.8 ± 7.6 kg) completed the match simulation on a non-motorised treadmill. Physiological measures were routinely taken, while psychomotor performance was assessed using the Eriksen flanker task (multiple-choice response time). Significant reductions (P < 0.05) were observed in distance covered and high-speed running during the second half when compared to the first. No significant differences (P > 0.05) in psychomotor performance at different time points were observed. Response time was significantly improved when running above 65% of maximal sprinting speed (P < 0.01). This data questions the application of the inverted-U hypothesis for intermittent exercise and suggests that the short high-intensity efforts may not result in the same physiological events that limit psychomotor performance during sustained high-intensity exercise. More so, the high-intensity efforts during the match protocol appeared to promote psychomotor performance during the intermittent exercise.     

How key transitions influence school and labour market careers of descendants of Moroccan and Turkish migrants in the Netherlands

Most educational research examines school outcomes at certain stages or at the final stage of the school career. This article looks at the entire school career and the transition to the labour market. It focuses on key transitions to identify the educational institutional arrangements that either help or hinder school and labour market success among the most disadvantaged groups in the Netherlands: young people of Moroccan and Turkish descent. The Dutch educational system is one of the most complicated school systems in Europe. Consequently, parents and children have to make many ‘choices’ when navigating it. Many of these key ‘choice’ moments are selection points, either because they are not real choices but dependent upon a teacher’s recommendation or because parents and pupils need a great deal of information about the school system in order to make a choice. This usually results in inequalities for the most disadvantaged groups. Because selection is disguised as ‘choices’, the structural inequalities of the Dutch school system are not usually perceived as blocking mechanisms for disadvantaged students     

Bookstores and Other Book Sources

Ruth Adler's A Day in the Life of the New York Times (Philadelphia: J.B. Lippincott, 1971—$6.77)

Les Daniels and The Mad Peck, Comix: A History of Comic Books in America (New York: Outerbridge &; Dienstfrey, 1971—$7.95)

75 Years of the Comics (Boston: Boston Book and Art Co., 1971—$9.95)

International Newspapers from University Microfilms (Ann Arbor, Michigan: University Microfilms, 1971—free on request, paper)

Chilton R. Bush (ed.) News Research for Better Newspapers (New York: American Newspaper Publishers Association Foundation, 750 Third Ave., 1965-date (annual), $2.00 or $3.00 each (set of last five volumes available for $10.00), paper)

Maurice F. Tauber and Hilda Feinberg's Book Catalogs (Metuchen, N.J.: Scarecrow Press, 1971—$15.00)

Martin E. Dann (ed.) The Black Press: 1827-1890 (New York: Putnam, 1971—$7.95)     

Neural adaptations with sport-specific resistance training in highly skilled athletes

The aim of this study was to assess the effects of variations in the volume and intensity of resistance training in highly skilled athletes on neural adaptive mechanisms: the maximality and pattern of neural drive. The maximality of muscle activation was measured using a high-resolution sample and hold amplifier to record interpolated twitches. The pattern of neural drive was measured by analysing isometric torque-time curves and electromyographic (EMG) characteristics during the performance of rapid isometric contractions at maximal effort. The volume and intensity of training were varied at 4-weekly intervals to systematically emphasize the development of strength, power and motor performance in 14 highly skilled track and field athletes (e.g. discus, hammer, javelin, shot put and weight). Knee extension strength increased significantly by 15% during steady maximal isometric contractions and by 24% during rapid isometric contractions at maximal effort after the 16-week training programme (P < 0.05). Increases in EMG amplitude and rate of EMG activation indicated that improvements to the pattern of neural drive occurred with sport-specific resistance training (P < 0.05). The maximality and pattern of neural drive did not change in the control group.     

Government Information Locator System and Government Information Management in the United States

20世纪90年代中期以后,随着电子政府服务的发展,美国联邦政府一些跨机构工作小组开始致力于政府信息定位服务(GILS)的相关调查研究,并在大量合作项目的基础上构建起联邦政府的GILS框架。此后,美国各州政府和机构也在此基础上探索构建了各具特色的GILS服务。GILS现已逐渐融合到美国电子政府整体建设之中,不仅通过因特网为公民提供政府数字信息,而且还可提供广泛的政府服务。各种类型的GILS服务之间的交流与合作也在积极展开。     

Identifying patterns and relationships among the responses of seventh-grade students to the science process skill of designing experiments

The development of reasoning skills, higher-level thinking skills, and science process skills are some of the benefits students can realize by participating in inquiry in the science laboratory. We used student responses to the Alternative Assessment of Science Process Skills (AASPS) developed by the Missouri Department of Education and the Department of Educational Assessment to develop the Science Process Skills Inventory (SPSI). The SPSI was then used to analyze student efforts at writing experimental designs. Our goal was to gain insight into factors that may be related to students successfully designing experiments. The instrument guides teachers and researchers in assessing seven main components of experimental designs. Each component consists of elements unique to the specific laboratory exercise. Subsequent to its development, the instrument was used to score 364 student responses to the “design an experiment” portion of an alternative assessment instrument for science process skills. Results indicate that explicit, incremental development of the science process skills of formulating hypotheses and identifying variables, together with model examples, may be a means to facilitate student success in designing science experiments. Implications for the classroom and for research are discussed. © 1996 John Wiley & Sons, Inc.