Coronary artery calcification is more prevalent in dialysis patients than in patients without kidney disease and this is associated with high serum phosphorus. In this study, we evaluate the effect ...of calcium carbonate or sevelamer treatments on the progression of calcification in 90 predialysis patients. Inclusion criteria were stable serum calcium, phosphorus, parathyroid hormone, and a similar baseline total calcium score (TCS). These patients were not treated by phosphate binder, vitamin D, or statin. They were given low-phosphorus diets without or with daily calcium carbonate or sevelamer throughout the study that averaged 2 years. Baseline demographic or clinical characteristics along with biochemical parameters were not different among the three groups. The TCS significantly increased in patients on the low-phosphorus diet alone, to a lesser extent in calcium carbonate-treated patients, and not at all in sevelamer-treated patients. The progression of coronary calcification paralleled that of the calcium score. Our study shows that sevelamer treatment should not be restricted to dialysis patients; however, a larger study should be undertaken to confirm these results.
Abstract According to the recent definition proposed by the Consensus conference on Acute Dialysis Quality Initiative Group, the term cardio-renal syndrome (CRS) has been used to define different ...clinical conditions in which heart and kidney dysfunction overlap. Type 1 CRS (acute cardio- renal syndrome) is characterized by acute worsening of cardiac function leading to AKI (5, 6) in the setting of active cardiac disease such as ADHF, while type – 2 CRS occurs in a setting of chronic heart disease. Type 3 CRS is closely link to acute kidney injury (AKI), while type 4 represent cardiovascular involvement in chronic kidney disese (CKD) patients. Type 5 CRS represent cardiac and renal involvement in several diseases such as sepsis, hepato – renal syndrome and immune – mediated diseases.
This study focuses on the analyses of field‐scale water flow originating from a drywell, using the 3‐D Richards equation for the local description of the flow in a spatially heterogeneous, combined ...vadose zone‐groundwater flow system. Realistic features of the flow system, that is, height of the groundwater table, records of the time‐dependent rainfall data, spatial heterogeneity of soil hydraulic properties and flow‐controlled attributes, as well as man‐controlled characteristics of the drywell, were considered in the analyses. The effect of (a) the depth‐dependency of the soil type, (b) the vertical position of the drywell's screen, and (c) the mode of water injection to the drywell (constant or time‐dependent), on the performance of the drywell, were examined. Results, and in particular those related to the importance of the soil type depth‐dependency with regard to the drywell performance, can be explained by the physics of flow in unsaturated soils of differing soil texture. Of specific significance is the transition zone between the two different soil types in the case in which the spatially‐heterogeneous coarse‐textured soil overlies the spatially heterogeneous fine‐textured soil. In this case, when most of the drywell screen is located within this transition zone and when the flow is transient and non‐monotonous, the downward flow from the drywell is maximized. Although this study is site‐specific, we believe that its results are novel and relevant for sandy to sandy‐clay soils associated with managed aquifer recharge technology based on a device whose vertical axis is perpendicular to the soil layering.
Key Points
Flow from a drywell is simulated for six 3‐D spatially heterogeneous, vadose zone ‐ groundwater (VZ‐GW) flow setups
Flows controlled by rain dynamics and constant injection scenarios are simulated
Fine textured layer at the lower part of the drywell will maximize downward fluxes
Wildfires shape ecosystems globally, yet little is known on their effects on wildlife distribution and spatial behaviour. We used bats as models to test the effects of fire on ecosystems because they ...are multi‐habitat specialists and feature ecological and life traits such as behavioural plasticity and longevity that make them able to respond to both short‐ and long‐term environmental changes. We aimed at testing the effects of a severe wildfire on a Mediterranean bat assemblage in terms of occupancy, activity and individual fitness. Here, we measure the effects of fire on activity levels and occupancy by a Mediterranean bat assemblage at the Vesuvius National Park, in Southern Italy, over 4 years, encompassing a year when a severe wildfire occurred. By comparing bat occurrence and activity at burnt versus unburnt sites with a Before‐After/Control‐Impact approach, we found that bat responses to wildfires are species specific and depend on the time elapsed since the fire. Species that rely more strongly on forest areas showed a strong short‐term adverse response in terms of occupancy and activity, while species adapted to open habitats showed no response 1 year after the wildfire. However, most species showed a general positive effect due to the passage of fire 2 years after its occurrence, probably because of vegetation regrowth. The wildfire event was also associated with reduced reproduction in at least one species, and to worse individual body conditions 1 year after the wildfire. Our results show that most bats in a Mediterranean ecosystem show resilience to the occurrence of fire, yet many species show negative short‐term responses by altering their spatial behaviour and decreasing their investment in reproduction. Future increases in fire occurrence and intensity due to climate change may alter bat assemblages and impair population viability in the long term, hampering the fundamental ecosystem services provided by structured bat communities.
We used bats as model organisms to assess the effects of a severe wildfire, and found that bat responses to wildfires are species‐specific and depend on the time elapsed since the fire. Forest species show a strong short‐term adverse response in terms of occupancy and activity, while species adapted to open habitats show no response, yet the wildfire also impaired reproduction in at least one of such species, and affected negatively its body condition 1 year after the wildfire.
We study the standard deviation of water saturation SDS as function of the mean saturation
〈S〉 by a stochastic model of unsaturated flow, which is based on the first‐order solution of the ...three‐dimensional Richards equation. The model assumes spatially variable soil properties, following a given geostatistical description, and it explicitly accounts for the different scales involved in the determination of the spatial properties of saturation: the extent L, i.e., the domain size, the spacing Δ among measurements, and the dimension
ℓ associated to the sampling measurement. It is found that the interplay between those scales and the correlation scale I of the hydraulic properties rules the spatial variability of saturation. A “scale effect” manifests for small to intermediate L/I, for which SDS increase with the extent L. This nonergodic effect depends on the structural and hydraulic parameters as well as the scales of the problem, and it is consistent with a similar effect found in field experiments. In turn, the influence of the scale
ℓ is to decrease the saturation variability and increase its spatial correlation. Although the solution focuses on the medium heterogeneity as the main driver for the spatial variability of saturation, neglecting other important components, it explicitly links the spatial variation of saturation to the hydraulic properties of the soil, their spatial variability, and the sampling schemes; it can provide a useful tool to assess the impact of scales on the saturation variability, also in view of the several applications that involve the saturation variability.
Key Points
We study the spatial variability of soil moisture by a three‐dimensional stochastic model of unsaturated flow
The model accounts for the three relevant scales: extent, spacing among measurements, support scale of the latter
Interplay between the scales and the correlation of the hydraulic properties rules the variability of saturation, a scale effect manifests
Many details about the flow of water in soils in a hillslope are unknowable given current technologies. One way of learning about the bulk effects of water velocity distributions on hillslopes is ...through the use of tracers. However, this paper will demonstrate that the interpretation of tracer information needs to become more sophisticated. The paper reviews, and complements with mathematical arguments and specific examples, theory and practice of the distribution(s) of the times water particles injected through rainfall spend traveling through a catchment up to a control section (i.e., “catchment” travel times). The relevance of the work is perceived to lie in the importance of the characterization of travel time distributions as fundamental descriptors of catchment water storage, flow pathway heterogeneity, sources of water in a catchment, and the chemistry of water flows through the control section. The paper aims to correct some common misconceptions used in analyses of travel time distributions. In particular, it stresses the conceptual and practical differences between the travel time distribution conditional on a given injection time (needed for rainfall‐runoff transformations) and that conditional on a given sampling time at the outlet (as provided by isotopic dating techniques or tracer measurements), jointly with the differences of both with the residence time distributions of water particles in storage within the catchment at any time. These differences are defined precisely here, either through the results of different models or theoretically by using an extension of a classic theorem of dynamic controls. Specifically, we address different model results to highlight the features of travel times seen from different assumptions, in this case, exact solutions to a lumped model and numerical solutions of the 3‐D flow and transport equations in variably saturated, physically heterogeneous catchment domains. Our results stress the individual characters of the relevant distributions and their general nonstationarity yielding their legitimate interchange only in very particular conditions rarely achieved in the field. We also briefly discuss the impact of oversimple assumptions commonly used in analyses of tracer data.
Key Points
Define properly the kinematics of catchment travel time distributions
Correct common misconceptions with notable implications, e.g., for tracer studies
Distinguish travel from residence time distributions
In the present work, an experimental study is presented aimed at assessing the chronic toxicity of three imidazole-based ionic liquids, i.e. imidazole (IM), 1-methylimidazole (1MIM), ...1-ethyl-3-methyl-imidazolium chloride (1E3MIM), and 1-butyl-3-methyl-imidazolium chloride (1B3MIM), generally considered as environmentally friendly surrogates of traditional industrial solvents. In this study Daphnia magna was used as test organism due to its wide application in the ecotoxicological literature of ionic liquids, monitoring both the cumulative survival of exposed organisms, and their reproductive parameters. The intracellular oxidative stress of daphnids was also assessed through the determination of Reactive Oxygen Species (ROS) and Catalase activity (CAT). The chronic toxicity of their oxidized by-products (BPs), generated by advanced oxidation treatment with UV254/H2O2, was finally evaluated. Four generations of BPs were considered, each formed at reaction times higher than those required for the complete removal of the parent compounds. Results indicate that IM and 1MIM have a moderate chronic toxicity, which mainly affects reproductive parameters. On the contrary, 1E3MIM and 1B3MIM showed significantly higher chronic toxicity effects resulting in a significant increase in the mortality of exposed organisms compared to the controls. UV/H2O2 treatment of the compounds did not always reduce the observed effects, since the generated BPs have, in some cases, higher chronic toxicity than their corresponding parent compounds. Chronic toxic effects remained significant up to the fourth generation of BPs in the cases of 1E3MIM and 1B3MIM, whereas they were found to be negligible from the second generation of BPs in the case of IM and 1MIM. The results of oxidative stress measurements confirmed the previous findings, suggesting a potential risk for the aquatic ecosystem induced by the mentioned compounds and their BPs.
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•Ionic Liquids are Contaminants on Horizon with toxicity mechanism poorly understood UV-C/H2O2 are efficient treatment for their removal from aqueous matrices•Treated solutions showed residual toxicity due to the photo-generated byproducts.•Treated and untreated solutions affected survival and reproduction of Daphnia Magna.•Longer treatment times are required to reduce the chronic toxicity of the solutions.
Artificial illumination at night (ALAN) alters many aspects of animal behaviour. Commuting and foraging bats have been found to be affected by ALAN, but no study has yet addressed the impact of ...lighting on drinking activity, despite its critical importance for bats. We experimentally illuminated cattle troughs used by drinking bats at four forest sites in Italy, and compared drinking activity and foraging activity under lit and dark conditions. We predicted that (1) the number of bat species and drinking events will be lower under illumination and (2) forest bat species will be more affected than edge specialists. We recorded 2549 drinking events from 12 species or species groups, most of which decreased drinking activity under illumination. The effects of ALAN on drinking were stronger than on foraging. Forest species never drank when the light was on. Edge‐foraging species reduced drinking activity while also increasing foraging under lit conditions. We highlight a previously overlooked negative effect of ALAN on bats, whose implications may be locally catastrophic. Given the importance of water sites for both bat foraging and drinking, their illumination should be forbidden, appropriately mitigated or, if necessary, compensated for with the creation of alternative drinking sites.
We show that artificial illumination leads to a dramatic decrease in bat drinking activity. We found that lighting affects drinking behaviour more than foraging and that even species usually regarded as light‐tolerant exhibit adverse reactions to light when drinking. Illumination of drinking sites may therefore have considerably harmful consequences for bat conservation (Image courtesy of Jens Rydell).
One of the main challenges of bioremediation is to define efficient protocols having a low environmental impact. We have investigated the effect of three treatments in oily-seawater after a real ...oil-spill occurred in the Gulf of Taranto (Italy). Biostimulation with inorganic nutrients allowed the biodegradation of the 73±2.4% of hydrocarbons, bioaugmentation with a selected hydrocarbonoclastic consortium consisting of Alcanivorax borkumensis, Alcanivorax dieselolei, Marinobacter hydrocarbonoclasticus, Cycloclasticus sp. 78-ME and Thalassolituus oleivorans degraded 79±3.2%, while the addition of nutrients and a washing agent has allowed the degradation of the 69±2.6%. On the other hand, microbial community was severely affected by the addition of the washing agent and the same product seemed to inhibit the growth of the majority of strains composing the selected consortium at the tested concentration. The use of dispersant should be accurately evaluated also considering its effect on the principal actors of biodegradation.
•Biostimulation treatments dominant signatures associated to hydrocarbonoclastic bacteria during the first 5days.•In the Bioaugmentation treatments hydrocarbonoclastic bacteria and α-proteobacteria were the dominant members.•Washing agent induced a biodiversity profile different compared to the other treatments.•The yield of the treatments as TPH degradation was slightly higher after the bioaugmentation test.
Abstract Chronic kidney disease (CKD) patients demonstrate higher rates of cardiovascular mortality and morbidity; and increased incidence of sudden cardiac death (SCD) with declining kidney failure. ...Coronary artery disease (CAD) associated risk factors are the major determinants of SCD in the general population. However, current evidence suggests that in CKD patients, traditional cardiovascular risk factors may play a lesser role. Complex relationships between CKD-specific risk factors, structural heart disease, and ventricular arrhythmias (VA) contribute to the high risk of SCD. In dialysis patients, the occurrence of VA and SCD could be exacerbated by electrolyte shifts, divalent ion abnormalities, sympathetic overactivity, inflammation and iron toxicity. As outcomes in CKD patients after cardiac arrest are poor, primary and secondary prevention of SCD and cardiac arrest could reduce cardiovascular mortality in patients with CKD.
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