Relevance of Risk Predictions Derived from a Chronic Species Sensitivity Distribution with Cadmium to Aquatic Populations and Ecosystems

Criteria to protect aquatic life are intended to protect diverse ecosystems, but in practice are usually developed from compilations of single‐species toxicity tests using standard test organisms that were tested in laboratory environments. Species sensitivity distributions (SSDs) developed from these compilations are extrapolated to set aquatic ecosystem criteria. The protectiveness of the approach was critically reviewed with a chronic SSD for cadmium comprising 27 species within 21 genera. Within the data set, one genus had lower cadmium effects concentrations than the SSD fifth percentile‐based criterion, so in theory this genus, the amphipod Hyalella, could be lost or at least allowed some level of harm by this criteria approach. However, population matrix modeling projected only slightly increased extinction risks for a temperate Hyalella population under scenarios similar to the SSD fifth percentile criterion. The criterion value was further compared to cadmium effects concentrations in ecosystem experiments and field studies. Generally, few adverse effects were inferred from ecosystem experiments at concentrations less than the SSD fifth percentile criterion. Exceptions were behavioral impairments in simplified food web studies. No adverse effects were apparent in field studies under conditions that seldom exceeded the criterion. At concentrations greater than the SSD fifth percentile, the magnitudes of adverse effects in the field studies were roughly proportional to the laboratory‐based fraction of species with adverse effects in the SSD. Overall, the modeling and field validation comparisons of the chronic criterion values generally supported the relevance and protectiveness of the SSD fifth percentile approach with cadmium.     

The early Cape anatomised

The Shaping of South African Society 1652–1820, edited by Richard Elphick and Hermann Giliomee. Cape Town: Longman, 1979.     

Emotion Knowledge, Social Competence, and Behavior Problems in Childhood and Adolescence: A Meta-analytic Review

The present meta-analytic review examined the magnitude of the relation between discrete emotion knowledge and three of its most commonly studied correlates in childhood and adolescence: social competence, internalizing problems, and externalizing problems. Emotion knowledge demonstrated small to medium-sized relations with each correlate. Moderators of effect size were also examined and included multiple sample and methodological characteristics. Using random effects models, significant moderators of effect size for relations between emotion knowledge and externalizing problems included sample recruitment, sample age, and the source of externalizing problems ratings. Moderators of effect size were not found for emotion knowledge and social competence, and the effect sizes across samples for emotion knowledge and internalizing problems were homogeneous. Results highlight the relatively consistent yet modest relations between emotion knowledge and its correlates. Implications for applied research and new directions for research on emotion knowledge using innovative methods are discussed.     

Confidence Intervals for Linear Combinations of Poisson Means

Parametric confidence intervals are given for linear combinations of the means of independent Poisson variables and for their continuous versions. The performance of the intervals is assessed using simulation. A real data set is used to compare the proposed intervals with known ones. The proposed intervals are shown to be superior to known ones and comparable to exact intervals.     

Relation of Goal Setting and Goal Sharing to Performance and Conflict for Interdependent Tasks

Despite the prevalence of goal setting in organizations, researchers have not thoroughly examined the implications of goal setting to work outcomes in interdependent work settings. A field survey (n= 442) assessed the relation of goal setting and goal sharing, the extent to which others are aware of an individual's work goal, to performance and conflict across varying levels of task interdependence. The results of moderated regression analyses demonstrate that in highly interdependent tasks, the use of goal setting resulted in lower performance levels. Moreover, goal setting and goal sharing in highly interdependent tasks resulted in individuals' reporting more somatic symptoms. The results are discussed in terms of clarifying the role of goal setting for interdependent tasks.     

Effects of the Mechanism of Receptor-Mediated Gene Expression on the Shape of the Dose-Response Curve

A mathematical model of receptor-mediated gene expression that includes receptor binding of natural and xenobiotic ligands, protein synthesis and degradation, and metabolism of the xenobiotic ligand was created to identify the determinants of the shape of the dose-response profile. Values of the model's parameters were varied to reflect alternative mechanisms of expression of the protein. These assumptions had dramatic effects on the computed response to a bolus dose of the xenobiotic ligand. If all processes in the model exhibit hyperbolic kinetics, the dose-response curves can appear sigmoidal but actually be linear with a positive slope at low doses. The slope of the curve only approached zero at low dose, indicative of a threshold for response, if binding of the xenobiotic ligand to the receptor exhibited positive cooperativity (ligand binding at one site increases the affinity for ligand at another binding site on the receptor). Positive cooperativity in the rate-limiting step of protein synthesis produced dose-response curves which were "U-shaped" at low doses, also indicative of a threshold. Positive cooperativity in the metabolism of the xenobiotic ligand produced dose-response curves that increased more rapidly than linearly with increasing dose. The model illustrates the fact that response cannot be predicted from qualitative mechanistic arguments alone; any assessment of risk to health from xenobiotic chemicals must be based on a detailed quantitative examination of the kinetic behavior of each chemical species individually.     

The Implications of Learning Styles for Training and Development: A Discussion of the Matching Hypothesis

This review paper examines the effect of matching and mismatching learning style and learning activity and matching and mismatching trainer and trainee learning style on learning achievement. It also explores the possibility of creating a match by promoting learner adaptability or modifying the trainer's training style. The implications of this discussion for training and development are considered.     

The Role of Effort in Shifting Preference for Feedback Stimuli

ABSTRACT

Researchers have examined preference for the format of delivery of feedback, however little research has examined strategies to increase feedback and praise desirability. The current study aimed to evaluate whether preference shifted for stimuli that signaled work and for manager-praise stimuli that were delivered after work. Moreover, we sought to understand if these preference shifts were greater when the work was higher-effort compared to lower-effort work tasks (a phenomenon described in the basic literature as within-trial contrast). The study took place in a simulated work environment. Sixteen university students clicked on a shape that produced the work task, completed a mock medical data-entry task, and received manager-praise on an FR1 and FR20 schedule. At the start of the study and following each contingency exposure trials, they completed a preference assessment for both the shapes and the manager-feedback stimuli. The primary dependent variable was the percentage of preference change for two categories of stimuli – shapes presented at the beginning of trials that signaled which condition participants were in and manager-praise stimuli presented at the end of trials. Preference for the shape stimuli for both high- and low-effort stimuli decreased indicating that stimuli that signal work may become less preferred. Preference for the manager-praise stimuli for both high- and low-effort stimuli increased suggesting that stimuli that follow work may become more preferred. Overall, these data suggest that the conditions under which managers deliver feedback and praise may influence preference for those stimuli.     

THE MEANING OF OCCUPATIONAL PRESTIGE SCORES:

This research reexamines the meaning of occupational prestige scores from the social psychological perspective of identity theory. Using comparable data for Canada and the United States, it analyzes the degree to which the education and income levels of occupations influence occupational prestige judgements by evoking affective associations (feelings about the goodness, powerfulness, and liveliness of occupational identities), as well as the extent to which these social sentiments are independent determinants of prestige. There has been a longstanding controversy about the normative content of occupational prestige scores. We find that moral worthiness (as measured by the Evaluation dimension of the semantic differential) is a determinant of the prestige of occupations with low and middle but not high levels of education and income. We also find that the impact of education on prestige scores is direct and cognitive, while a considerable proportion of the total effect of income is processed through feelings about the potency of occupations. The results for the two countries are very similar. One exception is that moral worthiness is a more important determinant of prestige in the United States than in Canada. We connect this finding to the literature comparing value differences between the two countries.