A double role of sperm in scorpions: the mating plug of Euscorpius italicus (Scorpiones: Euscorpiidae) consists of sperm

Mating plugs occluding the female gonopore after mating are a widespread phenomenon. In scorpions, two main types of mating plugs are found: sclerotized mating plugs being parts of the spermatophore that break off during mating, and gel-like mating plugs being gelatinous fluids that harden in the female genital tract. In this study, the gel-like mating plug of Euscorpius italicus was investigated with respect to its composition, fine structure, and changes over time. Sperm forms the major component of the mating plug, a phenomenon previously unknown in arachnids. Three parts of the mating plug can be distinguished. The part facing the outside of the female (outer part) contains sperm packages containing inactive spermatozoa. In this state, sperm is transferred. In the median part, the sperm packages get uncoiled to single spermatozoa. In the inner part, free sperm is embedded in a large amount of secretions. Fresh mating plugs are soft gelatinous, later they harden from outside toward inside. This process is completed after 3-5 days. Sperm from artificially triggered spermatophores could be activated by immersion in insect Ringer's solution indicating that the fluid condition in the females' genital tract or females' secretions causes sperm activation. Because of the male origin of the mating plug, it has likely evolved under sperm competition or sexual conflict. As females refused to remate irrespective of the presence or absence of a mating plug, females may have changed their mating behavior in the course of evolution from polyandry to monandry.

Antennal courtship and functional morphology of tyloids in the parasitoid wasp Syrphoctonus tarsatorius (Hymenoptera: Ichneumonidae: Diplazontinae)

Courtship behaviour and associated morphological characters are believed to evolve under diversifying sexual selection. In Hymenoptera, sexually dimorphic antennal structures, the 'tyloids', show a large variability. Although crucial for functional interpretation, the link between tyloid morphology and courtship behaviour has gained only limited attention. Here, we investigate antennal morphology and antennal courtship in the parasitoid wasp Syrphoctonus tarsatorius (Hymenoptera: Ichneumonidae: Diplazontinae). We confirm the glandular nature of the tyloids by light and scanning electron microscopy. Moreover, we report a new form of antennation during courtship, antennal double-coiling, which links morphology and behaviour by bringing the tyloids in direct contact with the antennae of the female, thus probably facilitating the transfer of a contact pheromone. We show that a change in haemolymph pressure is the activator of the antennal movement and that it can be reproduced in the laboratory using amputated antennae. Investigations of antennal structure and movement in three additional hymenopteran species suggest that the number and location of tyloids coincide with the modality of antennal coiling. Our method for simulating antennal movement will enable retrieving information about courtship behaviour from museum specimens, thus leading to a better understanding of the evolution of courtship behaviour in Hymenoptera.

Mixed intoxication with Aconitum nappellans (monkshood) and Digitalis grandiflora (large yellow foxglove)

Intoxications are frequent and relevant medical problems in emergency units.

A randomized trial of effects of health risk appraisal combined with group sessions or home visits on preventive behaviors in older adults

Background. To explore effects of a health risk appraisal for older people (HRA-O) program with reinforcement, we conducted a randomized controlled trial in 21 general practices in Hamburg, Germany. Methods. Overall, 2,580 older patients of 14 general practitioners trained in reinforcing recommendations related to HRA-O-identified risk factors were randomized into intervention (n = 878) and control (n = 1,702) groups. Patients (n = 746) of seven additional matched general practitioners who did not receive this training served as a comparison group. Patients allocated to the intervention group, and their general practitioners, received computer-tailored written recommendations, and patients were offered the choice between interdisciplinary group sessions (geriatrician, physiotherapist, social worker, and nutritionist) and home visits (nurse). Results. Among the intervention group, 580 (66%) persons made use of personal reinforcement (group sessions: 503 [87%], home visits: 77 [13%]). At 1-year follow-up, persons in the intervention group had higher use of preventive services (eg, influenza vaccinations, adjusted odds ratio 1.7; 95% confidence interval 1.4–2.1) and more favorable health behavior (eg, high fruit/fiber intake, odds ratio 2.0; 95% confidence interval 1.6–2.6), as compared with controls. Comparisons between intervention and comparison group data revealed similar effects, suggesting that physician training alone had no effect. Subgroup analyses indicated favorable effects for HRA-O with personal reinforcement, but not for HRA-O without reinforcement. Conclusions. HRA-O combined with physician training and personal reinforcement had favorable effects on preventive care use and health behavior.

Quantitative repeated open application testing with a rinse-off product in methyldibromo glutaronitrile-sensitive patients: results of the IVDK

While the use of methyldibromo glutaronitrile (MDBGN) in leave-on products is clearly associated with high sensitization or elicitation risk, such a clear-cut relation could be questioned with regard to rinse-off products.