River histories : A thematic review

Peer reviewe

Seven decades of hydrogeomorphological changes in a near‐natural (Sense River) and a hydropower‐regulated (Sarine River) pre‐Alpine river floodplain in Western Switzerland

This is the peer reviewed version which has been published in final form at https://doi.org/10.1002/esp.5017 . This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions.Hydropower alteration of the natural flow and sediment regime can severely degrade hydromorphology, thereby threatening biodiversity and overall ecosystem processes of rivers and their floodplains. Using sequences of aerial images, we quantified seven decades (1938/1942–2013) of spatiotemporal changes in channel and floodplain morphology, as well as changes in the physical habitats, of three floodplain river reaches of the Swiss pre‐Alps, two hydropower‐regulated and one near‐natural. In the Sarine River floodplain, within the first decades of hydropower impairment, the magnitude and frequency of flood events (Q2, Q10, Q30) decreased substantially. As a result, the area of pioneer floodplain habitats that depend on flood activity and sediment dynamic, such as bare sediments, decreased dramatically by approximately 95%. However, by 2013 vegetated areas had generally increased in comparison to the pre‐regulation period in 1943, indicating general vegetative colonization. Between 1943 and 2013, the active channel underwent essential narrowing (up to 62% width reduction in the residual flow reach) and habitat turnover rates were very low (5% of the total floodplain area changed habitat type five to six times). In contrast, from the 1950s onwards, the near‐natural floodplain of the Sense River experienced recurrent narrowing and widening, and frequent changes between bare and vegetated areas, reflecting the shifting habitat mosaic concept typical for natural floodplains. In the three reaches investigated, we found that the active floodplain width and erosion of vegetated areas were primarily controlled by medium to large floods (Q10, Q30), which combined with reduced time intervals between ordinary floods ≥ Q2 most likely mobilized streambed sediments and limited the ability of vegetation to establish itself on bare gravel bars within the parafluvial zone. These findings can contribute to restoration action plans such as controlled flooding and sediment replenishments in the Sarine and other floodplain rivers of the Alps

Quantitative and Functional Assessment of the Influence of Routinely Used Cryopreservation Media on Mononuclear Leukocytes for Medical Research

Quantitative and functional analysis of mononuclear leukocyte populations is an invaluable tool to understand the role of the immune system in the pathogenesis of a disease. Cryopreservation of mononuclear cells (MNCs) is routinely used to guarantee similar experimental conditions. Immune cells react differently to cryopreservation, and populations and functions of immune cells change during the process of freeze–thawing. To allow for a setup that preserves cell number and function optimally, we tested four different cryopreservation media. MNCs from 15 human individuals were analyzed. Before freezing and after thawing, the distribution of leukocytes was quantified by flow cytometry. Cultured cells were stimulated using lipopolysaccharide, and their immune response was quantified by flow cytometry, quantitative polymerase chain reaction (qPCR), and enzyme-linked immunosorbent assay (ELISA). Ultimately, the performance of the cryopreservation media was ranked. Cell recovery and viability were different between the media. Cryopreservation led to changes in the relative number of monocytes, T cells, B cells, and their subsets. The inflammatory response of MNCs was altered by cryopreservation, enhancing the basal production of inflammatory cytokines. Different cryopreservation media induce biases, which needs to be considered when designing a study relying on cryopreservation. Here, we provide an overview of four different cryopreservation media for choosing the optimal medium for a specific task