Search results for " Biologie"
showing 5 items of 65 documents
Limitations of population models in predicting climate change effects : a simulation study of sociable weavers in southern Africa
2008
Current approaches for predicting climate change effects on populations comprise static models based on the geographical distribution of species, and dynamic population models based on the relationship between population processes and the recent variation in climate. Population models have the inherent advantage of considering a species' response to climate as resulting from distinct mechanisms. However, they may have the disadvantage of considering only short-term processes as they occur under the current climate, disregarding slowly adapting mechanisms. It would be important, however, to know whether slowly adapting processes occur, and whether they will respond to climate change. A way o…
Analysis of the Cellular Roles of MOCS3 Identifies a MOCS3-Independent Localization of NFS1 at the Tips of the Centrosome
2019
The deficiency of the molybdenum cofactor (Moco) is an autosomal recessive disease, which leads to the loss of activity of all molybdoenzymes in humans with sulfite oxidase being the essential protein. Moco deficiency generally results in death in early childhood. Moco is a sulfur-containing cofactor synthesized in the cytosol with the sulfur being provided by a sulfur relay system composed of the L-cysteine desulfurase NFS1, MOCS3, and MOCS2A. Human MOCS3 is a dual-function protein that was shown to play an important role in Moco biosynthesis and in the mcm(5)s(2) U thio modifications of nucleosides in cytosolic tRNAs for Lys, Gln, and Glu. In this study, we constructed a homozygous MOCS3 …
Temperature effects explain continental scale distribution of cyanobacterial toxins
2018
Insight into how environmental change determines the production and distribution of cyanobacterial toxins is necessary for risk assessment. Management guidelines currently focus on hepatotoxins (microcystins). Increasing attention is given to other classes, such as neurotoxins (e.g., anatoxin-a) and cytotoxins (e.g., cylindrospermopsin) due to their potency. Most studies examine the relationship between individual toxin variants and environmental factors, such as nutrients, temperature and light. In summer 2015, we collected samples across Europe to investigate the effect of nutrient and temperature gradients on the variability of toxin production at a continental scale. Direct and indirect…
Polyester microplastic fibers in soil increase nitrogen loss via leaching and decrease plant biomass production and N uptake
2022
Abstract Microplastic contamination, like other global change factors, can induce effects on ecosystem functions and processes, affecting various soil biophysical properties. However, effects of such contaminants on nutrient cycles in agroecosystems are still poorly understood. We here performed two pot experiments to investigate the effect of polyester microplastic fibers (PMFs) on soil physical properties, nitrogen cycle, and plant performance in a maize-based agroecosystem. Moreover, we followed the N loss via leaching in soil contaminated or not with PMFs by simulating heavy rainfall events that mimic a future scenario of climate change. Our results show that soil contaminated with PMFs…
Antioxidant Therapies and Oxidative Stress in Friedreich´s Ataxia: The Right Path or Just a Diversion?
2020
Friedreich's ataxia is the commonest autosomal recessive ataxia among population of European descent. Despite the huge advances performed in the last decades, a cure still remains elusive. One of the most studied hallmarks of the disease is the increased production of oxidative stress markers in patients and models. This feature has been the motivation to develop treatments that aim to counteract such boost of free radicals and to enhance the production of antioxidant defenses. In this work, we present and critically review those 'antioxidant' drugs that went beyond the disease's models and were approved for its application in clinical trials. The evaluation of these trials highlights some …