A lover, not a fighter: mating causes male crickets to lose fights

Both resource-holding potential (RHP) and experience in aggressive contests are known to affect future aggressive behaviour. However, few studies have examined the effects of mating experience on agonistic behaviour, despite the fact that dominant males usually acquire more matings. We investigated the effect of mating experience on male aggressive behaviour including the relationship between RHP and fighting success in the fall field cricket, Gryllus pennsylvanicus. We formed pairs of size- and age-matched males that varied in RHP (relative weapon size) and conducted two experiments. In the first, we varied male mating experience by allowing one male in a pair to either be (a) ‘mated’: court, be mounted and copulate with a virgin female or (b) ‘experienced’: court, be mounted, but prevented from copulating. The second experiment varied postcopulatory experience where the male was allowed (‘contact’) or prevented from (‘no-contact’) continued contact with his recent mate. Following treatment, experimental males engaged in an aggressive contest with the naïve size- and age-matched male. In our first experiment, we found that mated and experienced males were equally likely to escalate contests to combat with a naïve opponent, but mated males were less likely than experienced males to win. There was no effect of mating on the relationship between RHP and fighting success. In our second experiment, we found no effect of maintaining contact with the female on the tendency to escalate or the probability of winning. As in the first experiment, males with relatively larger heads again won more fights and this relationship was unaffected by male experience. These results suggest that mating is itself detrimental to male success in aggressive contests, but that this effect is not sufficient to eliminate the effect of RHP on fighting success.     

Blending Linz–Donawitz and Blast Furnace slags with the Kambara reactor byproduct to improve their reuse in roadworks

Journal of Material Cycles and Waste Management - The use of industrial byproducts as replacement of natural aggregates has been extensively investigated to design eco-friendly roads. One of the...     

Characteristics of fear of crime in evacuation shelters after the Great East Japan Earthquake

After the Great East Japan Earthquake in March 2011, numerous evacuees had to stay in evacuation shelters such as school gymnasiums. In general, after a disaster, ensuring the safety and security of evacuees in evacuation shelters is a serious problem. Consequently, many of these evacuees feared that they would be victims of crime in the shelters or that their evacuated homes would be burgled. To examine what factors evoke a general fear of crime in shelters and burglary of evacuated homes, we conducted an online questionnaire on 300 evacuees in Miyagi Prefecture who had stayed at such shelters. From a factor analysis of fear of 16 specific kinds of crime in shelters, we extracted two factors representing fear of property and female-related crime. We then found that a general fear of crime in shelters was associated with being young and a fear of female-related crime, while a fear of burglary of evacuated homes was associated with being female, owning a detached house, and fear of property crime. Based on these results, we provide recommendations aiming to help reduce the fear of crime in shelters and burglary of evacuated homes.     

Low priorities for black american leaders: Environmental and occupational health

Summary Black Americans face increased health risks from environmental and occupational exposures when compared with white Americans, but they also face increased risks for more immediate health problems such as HIV infection/AIDS, alcohol and drug abuse, violence, and infant mortality. A survey of more than 1,000 black public health and black political leaders solicited opinions on the relative importance of 1) environmental health and 2) occupational health and safety compared with other public health problems faced by the black community. The survey also determined opinions about the degree to which specific health problems are amenable to change for black Americans and who (or what agency) should spearhead efforts aimed at specific public health objectives.Responding black leaders felt environmental health and occupational health and safety goals were somewhat important for black Americans, but among the most difficult of all public health objectives to meet. Those who felt that the above objectives were very important identified the federal govemment as the primarily responsible party for seeing that the objectives are met.Dr Dona Schneider is Assistant Professor of Public Health at Rutgers University. She teaches epidemiology and biostatistics for the New Jersey Graduate Program in Public Health at the University of Medicine and Dentistry of New Jersey, and holds memberships in both the Environmental and Occupational Health Sciences Institute and the National Institute for Environmental and Health Sciences. Her research spans the health problems of children and minorities. She regularly reviews books for theEnvironmentalist.     

Tiefsee-Bergbau auf Manganknollen vor dem Hintergrund globaler Versorgungs- und Umwelt-Probleme

Ich danke C. Kaubisch (Göttingen) herzlich für die graphische Ausf ührung der Abb., Prof. H. Thiel (Hamburg) besonders für kritische Diskussionen, Durchsicht des Manuskriptes und wertvolle Anregungen. Ebenso danke ich Dr. M. Sturm (EAWAG/ETH Zürich) für Kritik und Anregungen.