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Publications

NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.

2024

Abstract

By the time they enter soils, engineered nanomaterials (ENM) have undergone physicochemical transformations and may no longer resemble the pristine materials which have been thoroughly investigated during two decades of nanotoxicology research. Is the behavior of environmentally relevant chemical forms of ENM different from that of other metallic species present in soils? Are they more available to soil organisms than their naturally occurring counterparts? The present study aimed at answering these questions, through the use of isotopically enriched ENMs, which could be traced at low concentrations in soil microcosms, despite high natural metallic background. The relevance of the chemical forms was ensured by introducing isotopically enriched 109Ag, 68ZnO and 46TiO2 ENM to a wastewater treatment plant and using the resulting sewage sludge (final sink for most ENM) as amendment in soil microcosms with earthworms. The sludge application rate to soil was similar to that used in agriculture and the experiment lasted for a month. Protocols using inductively coupled plasma mass spectrometry were developed for determination of isotope ratios in complex matrixes, such as soil and organisms. For 109Ag ENM, the dissolved fraction in soil (i.e. the most easily accumulated in organisms) was extremely low and comparable to that of Ag naturally present in soil, and transfer factors to earthworms were similar to those of natural Ag. For 46TiO2 ENM, the transfer to earthworms was negligible, similarly to what was observed for natural Ti. While no difference in behavior and bioavailability was observed between ENM and their naturally occurring counterparts for Ag and Ti, different results were obtained for Zn. The dissolved fraction for 68ZnO ENM was 3-5 times higher than for Zn forms naturally present in soil, and transfer factors to earthworms twice those of natural Zn. Overcoming long-standing challenges related to environmental relevance of chemical forms and concentrations in nanotechnology studies, the approach provides valuable insight into behavior and impacts of environmentally relevant forms of ENM in soils.

To document

Abstract

Caring for newborn offspring hampers resource acquisition of mammalian females, curbing their ability to meet the high energy expenditure of early lactation. Newborns are particularly vulnerable, and, among the large herbivores, ungulates have evolved a continuum of neonatal antipredator tactics, ranging from immobile hider (such as roe deer fawns or impala calves) to highly mobile follower offspring (such as reindeer calves or chamois kids). How these tactics constrain female movements around parturition is unknown, particularly within the current context of increasing habitat fragmentation and earlier plant phenology caused by global warming. Here, using a comparative analysis across 54 populations of 23 species of large herbivores from 5 ungulate families (Bovidae, Cervidae, Equidae, Antilocapridae and Giraffidae), we show that mothers adjust their movements to variation in resource productivity and heterogeneity according to their offspring’s neonatal tactic. Mothers with hider offspring are unable to exploit environments where the variability of resources occurs at a broad scale, which might alter resource allocation compared with mothers with follower offspring. Our findings reveal that the overlooked neonatal tactic plays a key role for predicting how species are coping with environmental variation.

To document

Abstract

The diversity of bats in Ethiopia comprises at least 80 species, among them the Ethiopian long-eared bat that was described in 2000. It is most likely endemic to the highlands of Ethiopia. However, knowledge of the distribution of the species is limited. During a bat survey in 12 regions of central Ethiopia stretched over 700 km along the Ethiopian Rift, we trapped long-eared bats at sites in three regions and confirmed the species' identity by molecular analysis. All occurrence sites of P. balensis were above 2500 m, confirming this taxon as a high-altitude species. Two of the regions are additions to the known range of P. balensis but it is most likely present in more high-altitude areas of Ethiopia than currently known. Additional surveys in so far unsampled areas are therefore indicated.