Search Results (6)

The mean annual water balance is essential for evaluating water availability in a catchment and planning water resources. Climate change alters this balance by affecting precipitation, evapotranspiration, and overall water availability. This study analyses the impact of climate change on the mean annual water balance in the Catamayo catchment, a key water source for irrigation and hydropower in southern Ecuador and northern Peru. A Budyko-based approach was employed due to its conceptual simplicity and proven robustness for estimating long-term water balances under changing climatic conditions. Using outputs from 23 Global Circulation Models (GCMs) under CMIP6’s SSP2-4.5 and SSP8.5 scenarios, the results indicate increasing aridity, particularly in the lower and middle parts of the catchment, which correspond to arid and semi-arid zones. Water availability may decrease by 26.3 ± 12.3% to 33.3 ± 17% until 2080 due to negligible changes (statistically speaking) in average precipitation but rising evapotranspiration. However, historical precipitation analysis (1961–2020) reveals an increasing trend over this historical period which can be attributed to natural climatic variability associated to the El Nino-Southern Oscillation (ENSO), possibly enhanced by anthropogenic climate change. A novel hybrid method combining the statistics of historical precipitation deficits with GCM mean projections provides estimates of future precipitation deficits. These findings suggest potential reductions in crop yields and hydropower capacity, which (although not quantitatively assessed in this study) are inferred based on the projected decline in water availability. Such impacts could lead to higher energy costs, increased reliance on fossil fuels, and intensified competition for water. Mitigation measures, including water-saving strategies, energy diversification, and integrated water resource management, are recommended to address these challenges. Full article

The inclusion of rumen buffers in ruminant feeds has gained widespread adoption for the prevention of rumen acidosis, thereby avoiding the negative production and health consequences of low rumen pH and resulting in improved feed efficiency. Benchmarking and quality controlling the performance of rumen buffer materials is of significant interest to feed mills and end-user producers. The aim of this study was to evaluate, develop and optimise a laboratory protocol to consistently and robustly evaluate rumen buffering materials in order to predict their in vivo efficacy. Three different methods were evaluated for determining the buffering potential of carbonate buffer materials: (a) 2 and 8 h static pH, (b) 8 h fixed HCl acid load addition and (c) 3 h acidotic diet simulation using acetic acid. Buffer material, threshold pH, test duration and interactions between all three variables were significant (p < 0.001) in evaluating the performance of the buffer materials. The acidotic diet simulation was found to provide a different ranking of materials to the 8 h fixed HCl acid load methodology. The results highlight the importance of method selection and test parameters for accurately evaluating the potential efficacy of rumen buffer materials. Full article

Polders are low-lying areas located in deltas, surrounded by embankments to prevent flooding (river or tidal floods). They rely on pumping systems to remove water from the inner rivers (artificial rivers inside the polder area) to the outer rivers, especially during storms. Urbanized polders are especially vulnerable to pluvial flooding if the drainage, storage, and pumping capacity of the polder is inadequate. In this paper, a Monte Carlo (MC) framework is proposed to evaluate the benefits of rainfall threshold-based flood warnings when mitigating pluvial flooding in an urban flood-prone polder area based on 24 h forecasts. The framework computes metrics that give the potential waterlogging duration, maximum inundated area, and pump operation costs by considering the full range of potential storms. The benefits of flood warnings are evaluated by comparing the values of these metrics across different scenarios: the no-warning, perfect, deterministic, and probabilistic forecast scenarios. Probabilistic forecasts are represented using the concept of “predictive uncertainty” (PU). A polder area located in Nanjing was chosen for the case study. The results show a trade-off between the metrics that represent the waterlogging and the pumping costs, and that probabilistic forecasts of rainfall can considerably enhance these metrics. The results can be used to design a rainfall threshold-based flood early warning system (FEWS) for a polder area and/or evaluate its benefits. Full article

Hurst’s seminal characterisation of long-term persistence (LTP) in geophysical records more than seven decades ago continues to inspire investigations into the Hurst phenomenon, not just in hydrology and climatology, but in many other scientific fields. Here, we present a new theoretical development based on stochastic Hurst–Kolmogorov (HK) dynamics that explains the recent finding that the Hurst coefficient increases with the spatial scale of averaging for regional annual precipitation. We also present some further results on the scale dependence of H in regional precipitation, and reconcile an apparent inconsistency between sample results and theory. LTP in average basin scale precipitation is shown to be consistent with LTP in the annual flows of some large river basins. An analysis of the crossing properties of precipitation deficits in regions exhibiting LTP shows that the Hurst coefficient can be a parsimonious descriptor of the risk of severe precipitation deficits. No evidence is found for any systematic trend in precipitation deficits attributable to anthropogenic climate change across the regions analysed. Future precipitation deficit risk assessments should, in the first instance, be based on stochastic HK simulations that encompass the envelope of uncertainty synonymous with LTP, and not rely exclusively on GCM projections that may not properly capture long-term natural variability in the climate. Some views and opinions are expressed on the implications for policy making in sustainable water resources management. Full article

Chronic diseases characterized by bone and cartilage loss are associated with a reduced ability of progenitor cells to regenerate new tissues in an inflammatory environment. A promising strategy to treat such diseases is based on tissue repair mediated by human mesenchymal stem cells (hMSCs), but therapeutic outcomes are hindered by the absence of small molecules to efficiently modulate cell behaviour. Here, we applied a high-throughput drug screening technology to bioprospect a large library of extracts from Irish deep-sea organisms to induce hMSC differentiation toward musculoskeletal lineages and reduce inflammation of activated macrophages. The library included extracts from deep-sea corals, sponges and filamentous fungi representing a novel source of compounds for the targeted bioactivity. A validated hit rate of 3.4% was recorded from the invertebrate library, with cold water sea pens (octocoral order Pennatulacea), such as Kophobelemnon sp. and Anthoptilum sp., showing the most promising results in influencing stem cell differentiation toward osteogenic and chondrogenic lineages. Extracts obtained from deep-sea fungi showed no effects on stem cell differentiation, but a 6.8% hit rate in reducing the inflammation of activated macrophages. Our results demonstrate the potential of deep-sea organisms to synthetize pro-differentiation and immunomodulatory compounds that may represent potential drug development candidates to treat chronic musculoskeletal diseases. Full article

Worldwide diffused diseases such as osteoarthritis, atherosclerosis or chronic kidney disease are associated with a tissue calcification process which may involve unexpected local stem cell differentiation. Current pharmacological treatments for such musculoskeletal conditions are weakly effective, sometimes extremely expensive and often absent. The potential to develop new therapies is represented by the discovery of small molecules modulating resident progenitor cell differentiation to prevent aberrant tissue calcification. The marine environment is a rich reserve of compounds with pharmaceutical potential and many novel molecules are isolated from macro and microorganisms annually. The potential of small molecules synthetized by marine filamentous fungi to influence the osteogenic and chondrogenic differentiation of human mesenchymal stem/stromal cells (hMSCs) was investigated using a novel, high-throughput automated screening platform. Metabolites synthetized by the marine-derived fungus Penicillium antarcticum were evaluated on the platform. Itaconic acid derivatives were identified as inhibitors of calcium elaboration into the matrix of osteogenically differentiated hMSCs and also inhibited hMSC chondrogenic differentiation, highlighting their capacity to impair ectopic calcification. Bioactive small molecule discovery is critical to address ectopic tissue calcification and the use of biologically relevant assays to identify naturally occurring metabolites from marine sources represents a strategy that can contribute to this effort. Full article