Some effects of early social stimulation on the emotional reactivity of ducklings

Newly hatched Khaki Campbell ducklings were housed with a conspecific for 24 h beginning at either 1 or 5 days of age. A third group of ducklings received no social stimulation. When tested on Day 7, ducklings afforded early social stimulation exhibited less distress calling and crouching in a novel open field than ducklings exposed to late or no social stimulation. A second experiment asked whether the above result was due to early social stimulation per se or to the separation which occurred at its termination. Newly hatched ducklings were housed with a conspecific beginning on Day 1. One-half of the birds were separated from their companions on Day 2; the rest were separated on Day 6. On Day 7, the ducklings that were separated early exhibited less crouching and distress calling in a novel open field than the birds that were separated late. This finding implies that the withdrawal of social stimulation, rather than social stimulation perse, was responsible for the reduced emotional behavior observed in Experiment I. It is concluded that early withdrawal of social stimulation generated a strong aversive reaction and that it was the strength and timing of this reaction that mediated the emotionality moderating effects found here. Under these circumstances, the primary function of early social stimulation was to establish a condition whereby the aversive reaction generated by separation would occur early.     

Measuring newspaper readership: A qualitative variable approach

Abstract

Newspaper readership is usually measured by a single variable such as frequency of use, amount of use, etc. This article argues that readership cannot be fully described by a single measure and suggests treating it as a latent variable reflecting the time, frequency, and completeness of readership on both Sundays and weekdays. This study uses data from 101 newspaper markets in the US. The latent variable can be either quantitative or qualitative. Factor analysis is used to define the quantitative variable and latent class analysis, the qualitative variable. The relationship between the approaches is studied with principal components analysis, profiling, and hierarchical linear models. The two approaches are shown to produce complementary conclusions when relating readership to demographics and content interests. Media consumption studies can examine both qualitative and quantitative latent variables and thereby enhance the interpretability and the scope of the results.     

Cognitive efficiency: A conceptual and methodological comparison

Cognitive efficiency (CE) is generally defined as qualitative increases in knowledge gained in relation to the time and effort invested in knowledge acquisition. Across disciplines, limited consensus exists concerning the conceptual and measurement properties of CE partly because some researchers indiscriminately use the construct of CE to describe neurological, instructional, performance, and learning efficiency. In this study, two models of measuring CE, the likelihood model (Hoffman & Schraw, 2010), and the deviation model ( [van Gog and Paas, 2008] and [Paas and van Merri?nboer, 1993]) were used to compare problem-solving outcomes and determine if different conceptual models of CE measure the same or different efficiency constructs. The two models yielded uncorrelated scores using the same data. Further, regression analysis revealed that unique variance associated with effort, self-efficacy judgments, and background knowledge differed according to the measurement model used, suggesting that either each measurement approach assessed a different facet of CE, or the efficiency constructs measured were altogether different. Practical applications of CE research for teaching and learning are discussed.     

Accuracy and Prediction in Throwing: A Taxonomic Analysis of Children's Performance

Abstract

The throwing and prediction performances of first, third and fifth grade boys and girls were analyzed within the framework of a four-part taxonomy originally conceived by Fitts (1965). Throwing performance was assessed under task conditions which varied the motion states of the thrower's body and the target (stationary or moving) by use of a dual pendulum apparatus. Accuracy scores were highest in a condition where both body and target were stationary, and lowest where both body and target were moving. Task conditions requiring motion of only target or of body were of intermediate difficulty, and scores for these tasks were not significantly different from each other. There was evidence of learning across trial blocks for all tasks, but no indication that rates of acquisition differed for the task types. Likewise, significant main effects were observed for age levels but no age X task type interactions were disclosed. Boys were more accurate than girls across task conditions, most noticeably on the two most difficult tasks. Comparison of subjects' ability to predict, from a stationary body position, the coincidence of the moving target with a standard reference point, and their ability to predict the coincidence of their moving body with the same reference point revealed lower error scores on the former prediction task.     

The radio influences speech

PATRIOTIC GORE: STUDIES IN THE LITERATURE OF THE CIVIL WAR. By Edmund Wilson. New York: Oxford University Press, 1962; pp. 816. $9.50; paper $3.95.

THE TRIPLE THINKERS: TWELVE ESSAYS ON LITERARY SUBJECTS. By Edmund Wilson. New York: Oxford University Press, 1948; pp. x+270. $6.50.     

The Meaning of Work/Life: A Corporate Ideology of Work/Life Balance

Organizations wield great power over the structure of contemporary life. Using the rhetorical method of cluster analysis, we investigated the construction of work/life issues on Web sites of companies on Fortune's 2004 list of “100 Best Companies to Work for.” By identifying key terms and the terms that clustered around them, we uncovered a corporate ideology of work/life: 1) work is the most important element of life; 2) life means family; 3) individuals are responsible for balance; and 4) organizations control work/life programs. We conclude that organizational work/life programs may increase, rather than decrease, the amount of control organizations exercise over personal life. We explore the implications of this finding as well as directions for future research.     

Urine dipstick analysis for identification of runners susceptible to acute kidney injury following an ultramarathon

Abstract

This study examined whether urine dipstick testing might be useful to predict the development of acute kidney injury after an ultramarathon. Participants in the 2011 161-km Western States Endurance Run underwent post-race blood and urine dipstick analyses. Of the 310 race finishers, post-race urine dipstick testing was completed on 152 (49%) and post-race blood also was obtained from 150 of those runners. Based on “injury” and “risk” criteria for acute kidney injury of blood creatinine 2.0 and 1.5 times estimated baseline, respectively, 4% met the criteria for injury and an additional 29–30% met the criteria for risk of injury. Those meeting the injury criteria had higher creatine kinase concentrations (P < 0.001) than those not meeting the criteria. Urine dipstick tests that read positive for at least 1+ protein, 3+ blood, and specific gravity ≥ 1.025 predicted those meeting the injury criteria with sensitivity of 1.00 (95% confidence interval [CI] 0.54–1.00), specificity of 0.76 (95% CI 0.69–0.83), positive predictive value of 0.15 (95% CI 0.06–0.30), negative predictive value of 1.00 (95% CI 0.97–1.00), and likelihood ratio for a positive test of 4.2. We conclude that urine dipstick testing was successfully able to identify those individuals meeting injury criteria for acute kidney injury with excellent sensitivity and specificity.     

A biomechanical comparison of dominant and non-dominant limbs during a side-step cutting task

Abstract

Numerous studies have investigated anterior cruciate ligament (ACL) injury risk by examining gender differences in knee and hip biomechanics during a side-step cutting manoeuvre since it is known that ACL injury often occurs during such a task. Recent investigations have also examined lower extremity (LE) biomechanics during side-step cutting in individuals following ACL reconstruction (ACLR). Common research practice is to compare knee and hip biomechanics of the dominant limb between groups but this can add considerable complexity for clinicians and researchers. At this time, it is not known if there is a difference in LE biomechanics between the dominant and non-dominant limb during side-step cutting. Three-dimensional kinematics and kinetics were collected while 31 healthy participants performed five, side-step cutting manoeuvres with the dominant and non-dominant limbs. Knee and hip variables examined are those commonly investigated in ACL injury literature. There were no differences between limbs in all but one variable (knee internal rotation). These results demonstrate that healthy individuals exhibit little side-to-side differences in certain LE biomechanics when performing a side-step cutting manoeuvre. These findings can be utilised by clinicians when conducting dynamic evaluations of their ACLR patients and when developing injury prevention and rehabilitation programmes.     

Differential effects of speed on two-dimensional foot strike pattern during barefoot and shod running in recreationally active men

ABSTRACT

The majority of barefoot running studies have not considered speed as an influential factor on foot strike pattern. The aim of this study was to investigate differences in foot strike pattern and spatiotemporal characteristics between barefoot and shod overground running at varying speeds. We first determined maximal running speed (Vm) over 50 m in 15 recreationally active men who self-reported as habitual rearfoot strikers. Participants then completed shod and barefoot running trials at different speeds equivalent to approximately 90%, 80%, 70% and 60% of Vm. Sagittal plane two-dimensional (2D) foot-ground contact angle, ankle plantar-dorsi flexion angle, contact time, flight time, step length and step rate variables for each trial were recorded. A significant interaction effect of running speed and footwear condition (p < 0.05) on foot-ground contact angle, ankle plantar-dorsi flexion angle and contact time was observed. There was a main effect of running speed (p < 0.01) on flight time, step length and step rate. There was a main effect of footwear condition on step length (p < 0.01). Participants were more inclined to plantarflex the ankle and contact the ground with the forefoot at higher percentages of Vm, especially when running barefoot.