Response of the benthic fauna of an urban stream during six years of restoration

Okeover Stream flows through the University of Canterbury campus and has been subject to restoration since 1998. While initially spring-fed, its main source of flow is now aquifer water, which has been used for cooling university buildings. Water quality is generally good, but the low-gradient streambed includes substantial amounts of fine inorganic sediment and organic matter including deciduous tree leaves. Restoration activities include riparian plantings, channel shaping, substratum manipulations and additions, the construction of sediment traps and macrophyte management. Thirty aquatic invertebrate taxa (13-19 per year) have been recorded in annual surveys since 2000. Paracalliope fluviatilis (Amphipoda), Copepoda and Oligochaeta were most abundant in all years, whereas Mollusca and Trichoptera always made up <4 % and <2 % of individuals, respectively. Furthermore, cased caddisflies were found only in the two (of four) downstream reaches, whereas Copepoda were predominantly in the upper two reaches where flow was generally slower. Low annual MCI (69-84) and SQMCI (3.5-4.8) values indicated the fauna comprised mainly species that are tolerant of poor water quality or degraded habitat conditions. Our data indicate that the invertebrate fauna has yet to respond positively to the changes in physical habitat and riparian conditions made along Okeover Stream. The introduction of pulses of poor quality water during heavy rainfalls, high levels of siltation, heavy metals in bed sediments, large accumulations of slowly decomposing leaves and an inadequate source of potential colonists may all contribute to the weak response of the invertebrate fauna to restoration activities

Peroxidasin protein expression and enzymatic activity in metastatic melanoma cell lines are associated with invasive potential

Peroxidasin, a heme peroxidase, has been shown to play a role in cancer progression. mRNA expression has been reported to be upregulated in metastatic melanoma cell lines and connected to the invasive phenotype, but little is known about how peroxidasin acts in cancer cells. We have analyzed peroxidasin protein expression and activity in eight metastatic melanoma cell lines using an ELISA developed with an in-house peroxidasin binding protein. RNAseq data analysis confirmed high peroxidasin mRNA expression in the five cell lines classified as invasive and low expression in the three non-invasive cell lines. Protein levels of peroxidasin were higher in the cell lines with an invasive phenotype. Active peroxidasin was secreted to the cell culture medium, where it accumulated over time, and peroxidasin protein levels in the medium were also much higher in invasive than non-invasive cell lines. The only well-established physiological role of peroxidasin is in the formation of a sulfilimine bond, which cross-links collagen IV in basement membranes via catalyzed oxidation of bromide to hypobromous acid. We found that peroxidasin secreted from melanoma cells formed sulfilimine bonds in uncross-linked collagen IV, confirming peroxidasin activity and hypobromous acid formation. Moreover, 3-bromotyrosine, a stable product of hypobromous acid reacting with tyrosine residues, was detected in invasive melanoma cells, substantiating that their expression of peroxidasin generates hypobromous acid, and showing that it does not exclusively react with collagen IV, but also with other biomolecules

Scientific understanding of East African climate change from the HyCRISTAL project

Integrating Hydro-Climate Science into Policy Decisions for Climate-Resilient Infrastructure and Livelihoods in East Africa (HyCRISTAL) is a Future Climate for Africa (FCFA) project funded to deliver new understanding of East African climate change and its impacts, and to demonstrate use of climate change information in long-term decision-making in the region. Here, we briefly summarise key findings from HyCRISTAL so far on climate change, as well as key findings from the pan-African FCFA project “IMPALA” relevant to East Africa, both in the context of previous literature on the topic

Scientific understanding of East African climate change from the HyCRISTAL project

Integrating Hydro-Climate Science into Policy Decisions for Climate-Resilient Infrastructure and Livelihoods in East Africa (HyCRISTAL) is a Future Climate for Africa (FCFA) project funded to deliver new understanding of East African climate change and its impacts, and to demonstrate use of climate change information in long-term decision-making in the region. Here, we briefly summarise key findings from HyCRISTAL so far on climate change, as well as key findings from the pan-African FCFA project “IMPALA” relevant to East Africa, both in the context of previous literature on the topic