Negative phenotypic and genetic associations between copulation duration and longevity in male seed beetles

Reproduction can be costly and is predicted to trade-off against other characters. However, while these trade-offs are well documented for females, there has been less focus on aspects of male reproduction. Furthermore, those studies that have looked at males typically only investigate phenotypic associations, with the underlying genetics often ignored. Here, we report on phenotypic and genetic trade-offs in male reproductive effort in the seed beetle, Callosobruchus maculatus. We find that the duration of a male's first copulation is negatively associated with subsequent male survival, phenotypically and genetically. Our results are consistent with life-history theory and suggest that like females, males trade-off reproductive effort against longevity

New Structural Variants of Aeruginosin Produced by the Toxic Bloom Forming Cyanobacterium Nodularia spumigena

Peer reviewe

Gender Separation Increases Somatic Growth in Females but Does Not Affect Lifespan in Nothobranchius furzeri

According to life history theory, physiological and ecological traits and parameters influence an individual's life history and thus, ultimately, its lifespan. Mating and reproduction are costly activities, and in a variety of model organisms, a negative correlation of longevity and reproductive effort has been demonstrated. We are employing the annual killifish Nothobranchius furzeri as a vertebrate model for ageing. N. furzeri is the vertebrate displaying the shortest known lifespan in captivity with particular strains living only three to four months under optimal laboratory conditions. The animals show explosive growth, early sexual maturation and age-dependent physiological and behavioural decline. Here, we have used N. furzeri to investigate a potential reproduction-longevity trade-off in both sexes by means of gender separation. Though female reproductive effort and offspring investment were significantly reduced after separation, as investigated by analysis of clutch size, eggs in the ovaries and ovary mass, the energetic surplus was not reallocated towards somatic maintenance. In fact, a significant extension of lifespan could not be observed in either sex. This is despite the fact that separated females, but not males, grew significantly larger and heavier than the respective controls. Therefore, it remains elusive whether lifespan of an annual species evolved in periodically vanishing habitats can be prolonged on the cost of reproduction at all

Innovation management responses to regulation:SUP-directive and replacing plastic

Abstract Changes in regulation trigger changes in the innovation environments. They may block specific development trajectories, but they may simultaneously inspire and stimulate completely new openings. In this study, we look into regulation that aims to address environmental problems and facilitate creation and diffusion of sustainable technologies and processes as we examine the responses of innovators to the regulation on plastic use and production—specifically, the so-called SUP-directive. A multiple-case study comprising six companies suggests that companies manage (with) the regulation-induced innovation and needs for change by adopting three distinctive strategies: (1) proactive change orientation, (2) reactive opportunity capturing, or (3) reactive survival mode. Acknowledging that sustainability-oriented regulation may push companies with environmentally friendly innovation activities and solutions towards reactive survival mode highlights the need for managerial agility in adjusting the solutions and the ability to adopt parallel innovation strategies. Observing the strategies adopted by innovators also is informative when evaluating whether the regulation meets its profound goals and intended effects