Friendship preferences among German and Turkish preadolescents

This study examined changes in and predictors of preference for same-ethnic friendships among German (N=106) and Turkish (N=45) preadolescents (M age=10.4 years) during their 1st year in an ethnically heterogeneous school. Drawing on the contact hypothesis, it examined the relation between children's attitudes and their preference for same-ethnic friendship. Among both German and Turkish children, the latter decreased over time and its variability was predicted by intergroup attitudes and peer norms about cross-ethnic friendships. Outgroup orientation and perceived contact conditions predicted only German children's preference for same-ethnic friendships. Over time, classroom identification increasingly reduced preference for same-ethnic friendships among Turkish children. The results showed that interindividual attitudes were related to children's level of intergroup contact.     

The influence of cue type and configuration upon radial-maze performance in the rat

The influence of cue type and cue configuration on radial-maze performance in rats was examined in two experiments. In the first experiment, it was found that rats provided with both salient intramaze and extramaze cues acquired the task faster than rats given only one set of cues. No difference in acquisition was found between a group trained with intramaze cues alone and a group trained with extramaze cues alone. In a cue-preference test, it was found that groups that had been trained with extramaze cues, intramaze cues, or both sets of cues relied on extra-maze cues to avoid visited arms when given both types of cues concurrently. When all groups were transferred to intramaze-cue-alone trials, only the group that had been originally trained with extramaze cues alone showed any disruption. Also, during the second half of the intramaze-cue-alone trials, the arrangement of these cues was randomly changed on each trial. This disruption in cue configuration did not deleteriously affect performance in any of the three groups; all remained above chance performance, although the performance of the group originally trained with extramaze cues alone was inferior to that of the other two groups. In Experiment 2, groups of rats were trained on daily alternating trials under intramaze-cue-alone and extramaze-cue-alone conditions. For one group, the configuration of intramaze cues was altered randomly on each trial; the other group had intramaze cues always presented in the same configuration over trials. It was found that acquisition was more rapid on intramaze trials in the group given static configurations. Also, acquisition of the extramaze task was faster than the intramaze task in the group given variable intramaze cue configurations. No difference was found between the intramaze and extramaze conditions in the group given static intramaze cue configurations. These data suggest that a static cue configuration may influence radial maze performance, but is not a necessary condition for such performance.     

The effect of nonreinforced stimulus exposure on the strength of a conditioned taste aversion as a function of retention interval: Do latent inhibition and extinction involve a shared process?

Two experiments examined the effects of nonreinforced flavor exposure on the strength of a conditioned taste aversion. Rats were conditioned by pairing maple flavor with LiC1. Prior to or subsequent to this pairing, some animals received nonreinforced exposure to either maple or saccharin. In separate subjects, preference for maple was tested 1 or 21 days after the last training episode. In the first experiment, the nonreinforced stimulus exposure occurred before conditioning (latent inhibition, or LI, procedure); in the second experiment, the nonreinforced exposure occurred after conditioning (extinction, or EXT, training). In both experiments, nonreinforced exposure to maple or saccharin reduced the magnitude of a conditioned maple aversion when testing occurred soon after conditioning. When testing was delayed, however, the attenuation due to nonreinforced saccharin exposure dissipated, both with the LI procedure and with EXT. In contrast, the nonreinforced exposure to maple was found to attenuate conditioned reactions at both short and long retention intervals. The release from generalized LI and spontaneous recovery following generalized EXT training are discussed in terms of retrieval processing. The possibility that the same mechanism may underlie LI and EXT is considered.     

Recognition memory for lists of visual stimuli in monkeys and humans

In Experiment 1, short-term memory for lists of visual stimuli was studied in four squirrel monkeys (Saimiri sciureus). A delayed-matching procedure was used in which a subject was presented with lists containing one, three, or six stimulus patterns, and memory for serial positions was probed by requiring the subject to choose between a list item and a nonlist item. The rate of item presentation was varied, as was the delay between the final item on a list and the retention test. In Experiment 2, the same procedures were used to compare recognition memory in four monkeys and four humans. Although differences in the levels and shapes of the serial-position curves appeared between species, both monkeys and humans showed primacy and recency effects. The presentation time of stimuli had a negligible effect on performance in both monkeys and humans, whereas delay significantly affected human retention but not monkey retention.     

Migration,Knowledge Transfer,and the Emergence of Australian Post-War Skiing: The Story of Charles William Anton

Skiing underwent substantial changes during the post-war years when the sport turned into a multi-billion dollar industry and a leisure activity for the masses. Despite its global nature and popularity, skiing in academic writing has not gained much recognition. This paper explores the role of knowledge transfer during the pioneering phase of post-war skiing in Australia. It describes the life of Charles William Anton, an Austrian refugee from the Anschluss who migrated to Sydney and subsequently became one of the founding fathers of Australian post-war skiing. The following pages show the multi-layered nature of skiing as a global sport by exemplifying how ideas spread from pre-war Europe to post-war Australia. The paper will also provide a case study about refugee knowledge transfer and the ‘productive process of absorption, adoption or rejection of knowledge’ that takes place once an idea has been introduced into a new environment.     

Glycated nail proteins as a new biomarker in management of the South Kivu Congolese diabetics

Introduction

Diagnosis and monitoring of diabetes mellitus in sub-Saharan Africa, based on blood analyses, are hampered by infrastructural and cultural reasons. The first aim of this study was to evaluate the diagnostic accuracy of glycated nail proteins for diabetes mellitus. The second aim was to compare the course of short- and long-term glycemic biomarkers after 6 months of antidiabetic treatment. These objectives should support our hypothesis that glycated nail proteins could be used as an alternative glycemic biomarker.

Materials and methods

This case-control study consisted of 163 black diabetics and 67 non-diabetics of the South Kivu (Democratic Republic of Congo). Diagnostic accuracy of glycated nail proteins was evaluated using ROC curve analysis. At the start of the study, glycated nail protein concentrations were compared between diabetics and non-diabetics, using a nitro blue tetrazolium (NBT) colorimetric method. In a subgroup of 30 diabetics, concentrations of glycated nail proteins, fasting glucose (Accu-Chek® Aviva), serum fructosamine (NBT) and HbA1c (DCA-2000+®) were measured at start and after 6 months.

Results

ROC analysis yielded an AUC of 0.71 (95% confidence interval (CI): 0.65-0.76) and a cut-off point of 3.83 μmol/g nail. Concentration of glycated nail proteins was significantly higher (P < 0.001) in diabetics in comparison with non-diabetics. After 6 months of antidiabetic treatment, a significant drop in the fasting glucose concentration (P = 0.017) and concentration of glycated nail proteins (P = 0.008) was observed in contrast to serum fructosamine and HbA1c.

Conclusions

Measurement of glycated nail proteins could be used to diagnose and monitor diabetes mellitus in sub-Saharan Africa.Key words: fasting glucose concentration, fructosamine, hemoglobin A1c protein, nails, sub-Saharan Africa, diabetes mellitus     

Book reviews

Bazzana, André; Cressier, Patrice; and Guichard, Pierre. Les châteaux ruraux d'al‐Andalus. Histoire et archéologie des husūn du sud‐est de l'Espagne. Preface by Pierre Toubert (Série Archéologie, XI). Madrid: Publications de la Casa de Velázquez, 1988. 326pp; illustrations (plates, maps, tables); bibliography, index.

Tāha, CAbdulwāhid Dhanūn. The Muslim Conquest and Settlement of North Africa and Spain (Exeter Arabic and Islamic Series, 3). London: Routledge, 1989. xiv + 280pp; £49.50.

Leaman, Oliver. Averroes and his Philosophy Oxford: Clarendon Press, 1988. 204pp.; £25.

Mas^cūdî. The Meadows of Cold: the Abbasids. Ed. & tr. P. Lunde & C. Stone. London: Kegan Paul International, 1989. 469 pp., 2 maps; £30.

Sirat, Colette. La philosophie juive médiévale en terre d'Islam. Paris: Presses du CNRS, 1988. 278 pp.

Epalza, Míkel de and others. Baños Arabes en el país Valenciano. [Valencia], Generalitat Valenciana: Consellería de Cultura, Educado i Ciència, 1989.157 pp., plates, figures., maps (unnumbered).

Waines, David In a Caliph's Kitchen.Medieval Arabic Cooking for the Modern Gourmet. London: Riad el‐Rayyes Books, 1989. 112pp., many illustrations; £14.

Abed, Shukri B. Aristotelian Logic and the Arabic Language in Alfārābi. Albany: State University of New York Press, 1991. xxv+201pp., two appendices, bibliography, index.

Meyerson, Mark D. The Muslims of Valencia in the Age of Fernando and Isabel: Between Coexistence and Crusade. Berkeley: University of California Press, 1991. xi + 372 pp.

Zacour, Norman. Jews and Saracens in the Consilia of Oldradus de Ponte. Toronto: Pontifical Institute of Medieval Studies, 1990. x+144pp., index; paperback.     

The relationship between technology, innovation, and firm performance—Empirical evidence from e-business in Europe

This article analyzes the relationship between the usage of Internet-based technologies, different types of innovation, and performance at the firm level. Data for the empirical investigation originates from a sample of 7302 European enterprises. The empirical results show that Internet-based technologies were an important enabler of innovation in the year 2003. It was found that all studied types of innovation, including Internet-enabled and non-Internet-enabled product or process innovations, are positively associated with turnover and employment growth. Firms that rely on Internet-enabled innovations are at least as likely to grow as firms that rely on non-Internet-enabled innovations. Finally, it was found that innovative activity is not necessarily associated with higher profitability. Possible reasons for this and implications are discussed.     

Matching-to-sample performance by pigeons trained with visual-duration compound samples

Pigeons were trained on duration matching-to-sample in which each of four combinations of signal type (red or white light) and duration (2 or 10 see) was mapped onto a different choice stimulus. Probe trials in Experiments 1 and 2 involved a successive presentation of two duration samples. In each experiment, birds tended to summate two durations when the same signal was presented twice, but not when two different signals appeared. These results contrast with those reported by Spetch and Sinha (1989), who found a summation effect with both same-signal and different-signal compounds. In Experiment 3, pigeons chose among two alternatives which were both associated with the duration of the sample but of which only one was also associated with the signal type of the sample. Pigeons systematically chose the stimulus that matched both sample duration and signal type. The implications of these findings are discussed in terms of transfer of training and coding of event duration.     

The Submaximal Lateral Shuffle Test: A reliability and sensitivity analysis

ABSTRACT

Lateral ankle stability and how it changes in different footwear has been investigated for years. Research, however, has shown a lack of reliability or sensitivity of available methodologies. This study aimed to evaluate the test-retest reliability and sensitivity of a novel lateral stability protocol, the Submaximal Lateral Shuffle Test (SLST). We recruited 11 and 40 participants to assess reliability and sensitivity of the SLST, respectively. Participants performed the SLST in footwear that differed in collar height and upper stiffness. ICC values showed good to excellent reliability in peak ankle angles and moments, ground reaction forces, impulses, stance time, and performance time. Significantly lower peak inversion and adduction angles and lower medio-lateral push off peak forces were found in the high cut shoes compared to the low cut shoes. The medio-lateral landing peak force showed lower forces in the high cut shoes. The smallest worthwhile change indicated meaningful differences in 70.0–82.5% of participants for inversion, adduction, medio-lateral landing peak, and push off peak forces. These results, however, were not systematic such that there was not a consistent direction of the difference for all participants. In conclusion, the SLST is a promising protocol to further investigate lateral stability in footwear.