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Bouzelboudjen, Mahmoud

Nom
Bouzelboudjen, Mahmoud
Affiliation principale
Fonction
Ancien.ne collaborateur.trice
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https://libra.unine.ch/handle/123456789/1079

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  • Publication
    Accès libre
    Serological signature of tick-borne pathogens in Scandinavian brown bears over two decades
    (2015-7-28)
    Paillard, Lye 
    ;
    Jones, Krista L.
    ;
    Evans, Alina L.
    ;
    Jacquet, Maxime 
    ;
    Berret, Jérémy 
    ;
    Lienhard, Reto
    ;
    Bouzelboudjen, Mahmoud 
    ;
    Arnemo, Jon M.
    ;
    Swenson, Jon E.
    ;
    Voordouw, Maarten 
    Background: Anthropogenic disturbances are changing the geographic distribution of ticks and tick-borne diseases. Over the last few decades, the tick Ixodes ricinus has expanded its range and abundance considerably in northern Europe. Concurrently, the incidence of tick-borne diseases, such as Lyme borreliosis and tick-borne encephalitis, has increased in the human populations of the Scandinavian countries. Methods: Wildlife populations can serve as sentinels for changes in the distribution of tick-borne diseases. We used serum samples from a long-term study on the Scandinavian brown bear, Ursus arctos, and standard immunological methods to test whether exposure to Borrelia burgdorferi sensu lato, the causative agent of Lyme borreliosis, and tick-borne encephalitis virus (TBEV) had increased over time. Bears had been sampled over a period of 18 years (1995-2012) from a southern area, where Ixodes ricinus ticks are present, and a northern area where ticks are uncommon or absent. Results: Bears had high levels of IgG antibodies against B. burgdorferi sensu lato but not TBEV. Bears at the southern area had higher values of anti-Borrelia IgG antibodies than bears at the northern area. Over the duration of the study, the value of anti-Borrelia IgG antibodies increased in the southern area but not the northern area. Anti-Borrelia IgG antibodies increased with the age of the bear but declined in the oldest age classes. Conclusions: Our study is consistent with the view that ticks and tick-borne pathogens are expanding their abundance and prevalence in Scandinavia. Long-term serological monitoring of large mammals can provide insight into how anthropogenic disturbances are changing the distribution of ticks and tick-borne diseases.
  • Publication
    Accès libre
    Spatial Group Structure as Potential Mechanism to Maintain Cooperation in Fish Shoals of Unrelated Individuals
    Cisarovsky, Gabriel
    ;
    Bshary, Andrea 
    ;
    Bouzelboudjen, Mahmoud 
    ;
    Bshary, Redouan 
    In public goods games, group members share the benefits created through individual investments. If benefits are shared equally, individual contributions readily become altruistic, and hence, a social dilemma arises in which group interests and individual interests oppose each other. However, contributions to public goods can be self-serving if each investor gains a disproportionate benefit from its own contribution. This scenario may hold for our study system, the interactions of shoaling-unrelated scalefin anthias Pseudanthias squamipinnis and the ectoparasitic blenny Plagiotremus tapeinosoma. The blenny bites off pieces of skin, mucus and scales from anthias that in return may chase the blenny. Chasing the blenny represents a public good as it makes the parasite change victim species for its next attack. Laboratory experiments using artificial Plexiglas hosts suggest that one reason why individuals contribute to the public good is that the blenny may specialise on non-punishing ‘free-riders’. Here, we investigated how far a spatial structure within the shoal and limited space use by the blenny may contribute to punishment being self-serving. Field observation reveals that anthias indeed live in spatially structured groups and that blennies have preferred areas for attacks. Thus, some anthias individuals are consistently more exposed to blennies than others and hence may gain disproportional benefits from their punishment. In conclusion, spatial structure may contribute to the maintenance of punishment in blenny–anthias interactions even when groups are large.