Individual and situational determinants of altruism and helping behaviour

Studies which have attempted to assess the relative contributions of individual and situational determinants of helping behaviour and altruism have yielded diverse and contradictory data. The present investigation attempts to reconcile some of these inconsistent findings by examining the interaction of individual factors such as personality and sex with situational influences such as group size and task involvement. Explanations of helping behaviour and empirical studies are critically reviewed and methodological problems considered. The first four experiments take place in the laboratory and employ a simulated emergency representing a person falling off a ladder. Results indicate that individual factors may be more meaningful predictors of helping behaviour when examined in light of relevant situational effects. Differences in the helpfulness of low and high Machiavellians, as measured by Christie's Mach IV Inventory, seem to emerge only when face-to-face interaction, latitude for improvisation, and emotional involvement are possible. In such situations, groups of low Machs appear more likely than groups of high Machs to aid a distressed victim. However, when subjects are alone, not communicating, or in mixed-Mach groups, no differences in helping are found. The findings also demonstrate that group size effects on helping may be enhanced when communication channels are blocked, ambiguous emergencies are employed, and passive confederates pose as bystanders. The last two experiments pool previous findings and more naturalistic data to explore the consistency of the helpfulness of individual subjects across several situations. The results cast doubt on the existence of general helping dispositions. The findings suggest that seemingly irrelevant factors often ignored by researchers may play an important role in studies of helping behaviour. Contradictory results of previous research may be at least partly due to a number of inappropriate assumptions about the strength of single variables, and between-study comparisons may thus be unjustified

Reliability and Validity of the Disability Assessment Structured Interview (DASI): A Tool for Assessing Functional Limitations in Claimants

Objective The aim of this study is to investigate the reliability and validity of the Disability Assessment Structured Interview (DASI). The DASI is a semi-structured interview for assessing long-term functional limitations concerning the work disability assessment of claimants. Methods A randomized controlled trial was conducted. Patients applying for a work-disability pension after 21 months of sick leave were independently interviewed and examined either by two physicians who had completed a DASI training period (n = 32) or by two physicians from a control group (n = 30) without any DASI training. Agreement percentages within both groups of physicians, eligibility for a disability benefit, and differences between the groups in terms of the scores given on the work-limitation items from the Functional Ability List (FAL) were measured to investigate reliability and concurrent validity. To determine the content validity, the insurance physicians who completed DASI training (n = 8) were asked to fill out a questionnaire concerning their opinion of the DASI. Additionally, patients filled out a questionnaire to measure their satisfaction as to the behavioral aspects of the physicians. Results The groups showed no important differences in agreement percentages (mean percentage about 80%) and eligibility for a disability benefit. In 9 out of 21 items the physicians of the control group indicated fewer work limitations compared to physicians using the DASI. All physicians agreed on the fact that the DASI was an acceptable tool in daily practice, one that provided a realistic picture of the patient and provided sufficient information to assess functional limitations. In addition, between the two groups, no differences were found as to the satisfaction of patients concerning the behavioral aspects of the physicians. Conclusion The DASI is a tool with a reasonable to good inter-rater reliability and content validity, and it appears to be acceptable to both patients and physicians. It did not improve inter-observer agreement beyond that of usual interview procedures used in the Netherlands. The DASI would seem to be a worthwhile tool for collecting self-reported information in order to assess functional limitations in claimants

Pervasive Sign Epistasis between Conjugative Plasmids and Drug-Resistance Chromosomal Mutations

Multidrug-resistant bacteria arise mostly by the accumulation of plasmids and chromosomal mutations. Typically, these resistant determinants are costly to the bacterial cell. Yet, recently, it has been found that, in Escherichia coli bacterial cells, a mutation conferring resistance to an antibiotic can be advantageous to the bacterial cell if another antibiotic-resistance mutation is already present, a phenomenon called sign epistasis. Here we study the interaction between antibiotic-resistance chromosomal mutations and conjugative (i.e., self-transmissible) plasmids and find many cases of sign epistasis (40%)—including one of reciprocal sign epistasis where the strain carrying both resistance determinants is fitter than the two strains carrying only one of the determinants. This implies that the acquisition of an additional resistance plasmid or of a resistance mutation often increases the fitness of a bacterial strain already resistant to antibiotics. We further show that there is an overall antagonistic interaction between mutations and plasmids (52%). These results further complicate expectations of resistance reversal by interdiction of antibiotic use

A framework for measurement and harmonization of pediatric multiple sclerosis etiologic research studies: The Pediatric MS Tool-Kit

Background: While studying the etiology of multiple sclerosis (MS) in children has several methodological advantages over studying etiology in adults, studies are limited by small sample sizes. Objective: Using a rigorous methodological process, we developed the Pediatric MS Tool-Kit, a measurement framework that includes a minimal set of core variables to assess etiological risk factors. Methods: We solicited input from the International Pediatric MS Study Group to select three risk factors: environmental tobacco smoke (ETS) exposure, sun exposure, and vitamin D intake. To develop the Tool-Kit, we used a Delphi study involving a working group of epidemiologists, neurologists, and content experts from North America and Europe. Results: The Tool-Kit includes six core variables to measure ETS, six to measure sun exposure, and six to measure vitamin D intake. The Tool-Kit can be accessed online (www.maelstrom-research.org/mica/network/tool-kit). Conclusion: The goals of the Tool-Kit are to enhance exposure measurement in newly designed pediatric MS studies and comparability of results across studies, and in the longer term to facilitate harmonization of studies, a methodological approach that can be used to circumvent issues of small sample sizes. We believe the Tool-Kit will prove to be a valuable resource to guide pediatric MS researchers in developing study-specific questionnaire

A framework for measurement and harmonization of pediatric multiple sclerosis etiologic research studies: The Pediatric MS Tool-Kit.

BackgroundWhile studying the etiology of multiple sclerosis (MS) in children has several methodological advantages over studying etiology in adults, studies are limited by small sample sizes.ObjectiveUsing a rigorous methodological process, we developed the Pediatric MS Tool-Kit, a measurement framework that includes a minimal set of core variables to assess etiological risk factors.MethodsWe solicited input from the International Pediatric MS Study Group to select three risk factors: environmental tobacco smoke (ETS) exposure, sun exposure, and vitamin D intake. To develop the Tool-Kit, we used a Delphi study involving a working group of epidemiologists, neurologists, and content experts from North America and Europe.ResultsThe Tool-Kit includes six core variables to measure ETS, six to measure sun exposure, and six to measure vitamin D intake. The Tool-Kit can be accessed online ( www.maelstrom-research.org/mica/network/tool-kit ).ConclusionThe goals of the Tool-Kit are to enhance exposure measurement in newly designed pediatric MS studies and comparability of results across studies, and in the longer term to facilitate harmonization of studies, a methodological approach that can be used to circumvent issues of small sample sizes. We believe the Tool-Kit will prove to be a valuable resource to guide pediatric MS researchers in developing study-specific questionnaire

A framework for measurement and harmonization of pediatric multiple sclerosis etiologic research studies: The Pediatric MS Tool-Kit.

BackgroundWhile studying the etiology of multiple sclerosis (MS) in children has several methodological advantages over studying etiology in adults, studies are limited by small sample sizes.ObjectiveUsing a rigorous methodological process, we developed the Pediatric MS Tool-Kit, a measurement framework that includes a minimal set of core variables to assess etiological risk factors.MethodsWe solicited input from the International Pediatric MS Study Group to select three risk factors: environmental tobacco smoke (ETS) exposure, sun exposure, and vitamin D intake. To develop the Tool-Kit, we used a Delphi study involving a working group of epidemiologists, neurologists, and content experts from North America and Europe.ResultsThe Tool-Kit includes six core variables to measure ETS, six to measure sun exposure, and six to measure vitamin D intake. The Tool-Kit can be accessed online ( www.maelstrom-research.org/mica/network/tool-kit ).ConclusionThe goals of the Tool-Kit are to enhance exposure measurement in newly designed pediatric MS studies and comparability of results across studies, and in the longer term to facilitate harmonization of studies, a methodological approach that can be used to circumvent issues of small sample sizes. We believe the Tool-Kit will prove to be a valuable resource to guide pediatric MS researchers in developing study-specific questionnaire