Children’s Reasoning About the Temporal Order of Past and Future Events

Four- and five-year-olds completed two sets of tasks that involved reasoning about the temporal order in which events had occurred in the past or were to occur in the future. Four-year-olds succeeded on the tasks that involved reasoning about the order of past events but not those that involved reasoning about the order of future events, whereas 5-year-olds passed both types of tasks. Individual children who failed the past-event tasks were not particularly likely to fail the more difficult future-event tasks. However, children's performance on the reasoning tasks was predictive of their performance on a task assessing their comprehension of the terms “before” and “after.” Our results suggest that there may be a developmental change over this age range in the ability to flexibly represent and reason about the before-and-after relationships between events.

Emotional intelligence, personality and decoding non-verbal expressions of emotion

Previous research has highlighted theoretical and empirical links between measures of both personality and trait emotional intelligence (EI), and the ability to decode facial expressions of emotion. Research has also found that the posed, static characteristics of the photographic stimuli used to explore these links affects the decoding process and differentiates them from the natural expressions they represent. This undermines the ecological validity of established trait-emotion decoding relationships. This study addresses these methodological shortcomings by testing relationships between the reliability of participant ratings of dynamic, spontaneously elicited expressions of emotion with personality and trait EI. Fifty participants completed personality and self-report EI questionnaires, and used a computer-logging program to continuously rate change in emotional intensity expressed in video clips. Each clip was rated twice to obtain an intra-rater reliability score. The results provide limited support for links between both trait EI and personality variables and how reliably we decode natural expressions of emotion. Limitations and future directions are discussed.

The Role of Work Group in Individual Sickness Absence Behavior

The purpose of our two-year follow-up study was to examine the effect of the social components of the work group, such as group absence norms and cohesion, on sickness absence behavior among individuals with varying attitudes toward work attendance. The social components were measured using a questionnaire survey, and data on sickness absence behavior were collected from the employers' records. The study population consisted of 19,306 Finnish municipal employees working in 1,847 groups (78% women). Multilevel Poisson regression modeling was applied. The direct effects of work group characteristics on sickness absence were mostly insignificant. In contrast, both of the social components of a work group had an indirect impact: The more tolerant the group absence norms (at both individual- and cross-level) and the lower the group cohesion (at the individual level), the more the absence behavior of an individual was influenced by his or her attitude toward work attendance. We conclude that work group moderates the extent to which individuals with a liberal attitude toward work attendance actually engage in sickness absence behavior.

Individual and Public-Program Adaptation: Coping with Heat Waves in Five Cities in Canada

Heat Alert and Response Systems (HARS) are currently undergoing testing and implementation in Canada. These programs seek to reduce the adverse health effects of heat waves on human health by issuing weather forecasts and warnings, informing individuals about possible protections from excessive heat, and providing such protections to vulnerable subpopulations and individuals at risk. For these programs to be designed effectively, it is important to know how individuals perceive the heat, what their experience with heat-related illness is, how they protect themselves from excessive heat, and how they acquire information about such protections. In September 2010, we conducted a survey of households in 5 cities in Canada to study these issues. At the time of the survey, these cities had not implemented heat outreach and response systems. The study results indicate that individuals' recollections of recent heat wave events were generally accurate. About 21% of the sample reported feeling unwell during the most recent heat spell, but these illnesses were generally minor. Only in 25 cases out of 243, these illnesses were confirmed or diagnosed by a health care professional. The rate at which our respondents reported heat-related illnesses was higher among those with cardiovascular and respiratory illnesses, was higher among younger respondents and bore no relationship with the availability of air conditioning at home. Most of the respondents indicated that they would not dismiss themselves as

Novel bioassays to examine the host-finding ability of plant-parasitic nematodes

We present two novel bioassays to be used in the examination of plant-parasitic nematode host-finding ability. The host-finding 'pipette-bulb assay' was constructed from modelled Pasteur pipette bulbs and connecting barrels using parafilm fastenings. This assay examines the direction of second-stage juvenile (J2) migration in response to a host seedling, through a moistened sand substrate, which underlies terminal upward-facing 'seedling bulbs', one containing a host seedling in potting compost, the other with only potting compost. An equal watering regime through both upward-facing seedling bulbs creates a directional concentration gradient of host diffusate chemotactic factors. Positive chemotactic stimuli cause the J2 to orientate and migrate towards the host plant. We present validation data collected from assays of the root-knot nematode, Meloidogyne incognita, and the potato cyst nematode, Globodera pallida, which indicate a highly significant positive attraction of J2 of both species to respective host plants. This represents a simple, quick and inexpensive method of assessing host-finding behaviour in the laboratory. We consider that the pipette-bulb assay improves on previous host-finding/chemo-attraction assays through creating a more biologically relevant environment for experimental J2; analysis is quick and easy, allowing the straightforward interpretation of results. In addition, we have developed an 'agar trough' sensory assay variant which we believe can be used rapidly to ratify nematode responses to chemical gustatory or olfactory cues. This was constructed from a water agar substrate such that two counting wells were connected by a raised central trough, all flooded with water. Two small water agar plugs were dehydrated briefly in an oven and then hydrated in either an attractant, repellent or water control; these plugs were then placed in the terminal counting wells and subsequently leached the attractant or repellent to form a concentration gradient along the central trough, which contained the initial J2 innoculum. Our data show that both M. incognita and G. pallida J2 are positively attracted to host diffusates. In addition, they displayed a strong repulsion in response to 1 M NaCl2. J2 of M. incognita displayed a mild aversion to a non-host oak root diffusate, whereas G. pallida J2 displayed a strong aversion to the same non-host diffusate; neither species responded to a compost leachate. We believe that the agar trough assay improves on previous methods by facilitating rapid diffusion of attractant or repellents. Both of the aforementioned assays were designed as tools to assess the impact of RNAi-based reverse genetics screens for gene targets involved in chemosensory orientation.

How resource quality differentially affects motivation and ability to fight in hermit crabs

Contesting animals typically gather information about the resource value and that information affects fight motivation. However, it is possible that particular resource characteristics alter the ability to fight independently of the motivation. Using hermit crabs, we investigate how the resource in terms of shell quality affects both motivation and ability to fight. These crabs fight for shells, but those shells have to be carried and may impose physiological costs that impede fight vigour. We find that the shell has different effects on motivation and ability. Potential attackers in very small shells were highly motivated to attack but, rather than having enhanced ability, unexpectedly quickly fatigued and subsequently were not more successful in the fights than were crabs in larger shells. We also examined whether defending crabs could gather information about the attacker's shell from the vigour of the attack. Defending crabs gave up quickly when a potential gain had been assessed, indicating that such information had been gathered. However, there was no indication that this could be owing to the activity of the attacker and the information is probably gathered via visual assessment of the shell.

Genomic instability in human lymphocytes irradiated with individual charged particles: Involvement of tumor necrosis factor a in irradiated cells but not bystander cells

Exposure to ionizing radiation can increase the risk of cancer, which is often characterized by genomic instability. In environmental exposures to high-LET radiation (e.g. Ra-222), it is unlikely that many cells will be traversed or that any cell will be traversed by more than one alpha particle, resulting in an in vivo bystander situation, potentially involving inflammation. Here primary human lymphocytes were irradiated with precise numbers of He-3(2+) ions delivered to defined cell population fractions, to as low as a single cell being traversed, resembling in vivo conditions. Also, we assessed the contribution to genomic instability of the pro-inflammatory cytokine tumor necrosis factor alpha (TNFA). Genomic instability was significantly elevated in irradiated groups ( greater than or equal totwofold over controls) and was comparable whether cells were traversed by one or two He-3(2+) ions. Interestingly, substantial heterogeneity in genomic instability between experiments was observed when only one cell was traversed. Genomic instability was significantly reduced (60%) in cultures in which all cells were irradiated in the presence of TNFA antibody, but not when fractions were irradiated under the same conditions, suggesting that TNFA may have a role in the initiation of genomic instability in irradiated cells but not bystander cells. These results have implications for low-dose exposure risks and cancer. (C) 2005 by Radiation Research Society.