Determinants of vigilance behavior in the ring-tailed coati (Nasua nasua): the importance of within-group spatial position

Individuals living in social groups are predicted to live under unequal predation risk due to their spatial location within the group. Previous work has indicated that individuals located at the edge of groups have higher “domains of danger”, thus are more likely to engage in vigilance or antipredator behavior. We studied the determinants of vigilance behavior in two groups of ring-tailed coatis in Iguazu National Park, Argentina. In addition to the expected pattern that coatis were more vigilant at the edge of the group, we found that individuals were particularly vigilant at the front edge of the group. This pattern conforms to predictions of differing predation risk caused by sit-and-wait predators with respect to mobile animal groups. In addition, coatis exhibited less vigilance when the number of neighbors within 5 m and group size increased. Of the three spatial variables tested, within-group spatial position was the most important predictor variable determining vigilance levels. These results confirm that spatial position has major effects on vigilance behavior, and that group directionality is an important factor which should be taken into account when measuring vigilance behavior. Coatis were more vigilant when juveniles less than 6 months old were in the groups. The presence of these young juveniles also affected the relationship between alarm response and vigilance levels. Coatis were more vigilant after strong alarm reactions, but only when young juveniles were not present in the groups. This may indicate that coatis give differential responses to alarm calls depending on the age of the caller. A comparison of antipredator vigilance between coatis and sympatric capuchin monkeys is consistent with the hypothesis that terrestriality leads to higher perceive predation risk for coatis.     

First-trimester diagnosis of hydrolethalus syndrome in a Chinese family

We report a case resembling hydrolethalus syndrome in a Chinese family. Fetal polydactyly, syndactyly, encephalocele and cardiac malformation were detected on ultrasound examination at 12 weeks' gestation. Termination of pregnancy was performed, and postmortem examination confirmed the findings. This is the first report of a first-trimester prenatal diagnosis of hydrolethalus syndrome in the Chinese population. Copyright © 2004 John Wiley & Sons, Ltd.     

The relationship between demographic/educational parameters and perceptions,knowledge and earthquake mitigation in Israel

Perceptions, knowledge and mitigation are factors that might play a role in preventing injury and loss of life during a major earthquake.² Little is known about the relationships between different demographic and educational parameters and these factors. A national representative sample of 495 adults was investigated in order to determine the relationship between demographic and educational parameters in terms of the perceived threat, perceived coping, knowledge and mitigation of earthquakes in Israel. Compared to females, males perceived the threat of earthquakes to be lower (t=3.183, p=0.002), manifested higher levels of perceived coping (t=2.55, p=0.011), and had higher levels of earthquake related knowledge (t=2.047, p=0.041). We conclude that there are gender differences in perceptions and knowledge regarding earthquakes.     

Improving situational awareness through the design of offshore installations

Maintaining the situational awareness of control room operators on offshore installations contributes to the timely diagnosis of conditions and making appropriate decisions. This is particularly important when dealing with events and incidents. Recent initiatives aimed at reducing operators’ exposure to the hazards of working on offshore installations may have a negative impact upon situational awareness within the control room environment.This paper discusses mitigation of the negative impact through the design and operation of the installation and control system; either by improving the general level of situational awareness or by specifically targeting the areas affected by these initiatives.     

The Long Term Weathering of Water-in-Oil Emulsions

This paper summarizes studies to determine the long-term stability of water-in-oil emulsions in the laboratory and in large tanks. The long-term stability of emulsions was investigated in the laboratory for up to 9 years and by studying emulsion formation in a large test tank over a period of 2-10 days.Two stable emulsions, formed in the laboratory, had been preserved for 5 and 9 years and remained stable despite a small water loss. The long-term stability appears to be similar to that for the short-term stability. Stable emulsion breakdown processes remain poorly understood, because these emulsions do not generally breakdown, but the primary processes may be mechanical break-up and water evaporation.The water-in-oil states produced were found to have analogous properties between the laboratory and two sets of experiments at a large test tank. No fundamental differences in states or properties were observed over the time periods studied (up to 222 h). The state of the oil was found to correlate well with a stability index as defined by the complex modulus divided by the oil viscosity. It is shown that this stability index becomes more useful when the viscosity of the oil is taken at the same time as the complex modulus measurement.The studies show that meso-stable emulsions will break down within 3 days, generally within 1 day and that those emulsions classified as stable remain up to 9 years under laboratory conditions. These studies also show that meso-stable emulsions do not reform, once broken.