Cyanobacterial blooms are an increasing threat to water quality and global water security caused by the nutrient enrichment of freshwaters. There is also a broad consensus that blooms are increasing ...with global warming, but the impacts of other concomitant environmental changes, such as an increase in extreme rainfall events, may affect this response. One of the potential effects of high rainfall events on phytoplankton communities is greater loss of biomass through hydraulic flushing. Here we used a shallow lake mesocosm experiment to test the combined effects of: warming (ambient vs. +4°C increase), high rainfall (flushing) events (no events vs. seasonal events) and nutrient loading (eutrophic vs. hypertrophic) on total phytoplankton chlorophyll‐a and cyanobacterial abundance and composition. Our hypotheses were that: (a) total phytoplankton and cyanobacterial abundance would be higher in heated mesocosms; (b) the stimulatory effects of warming on cyanobacterial abundance would be enhanced in higher nutrient mesocosms, resulting in a synergistic interaction; (c) the recovery of biomass from flushing induced losses would be quicker in heated and nutrient‐enriched treatments, and during the growing season. The results supported the first and, in part, the third hypotheses: total phytoplankton and cyanobacterial abundance increased in heated mesocosms with an increase in common bloom‐forming taxa—Microcystis spp. and Dolichospermum spp. Recovery from flushing was slowest in the winter, but unaffected by warming or higher nutrient loading. Contrary to the second hypothesis, an antagonistic interaction between warming and nutrient enrichment was detected for both cyanobacteria and chlorophyll‐a demonstrating that ecological surprises can occur, dependent on the environmental context. While this study highlights the clear need to mitigate against global warming, oversimplification of global change effects on cyanobacteria should be avoided; stressor gradients and seasonal effects should be considered as important factors shaping the response.
Cyanobacteria are expected to benefit from a warmer climate, especially in nutrient‐rich waters. However, other important climate change factors—more extreme rainfall events—could affect this response (e.g. loss through flushing). This mesocosm study tested the combined effects of warming, extreme rainfall events and nutrient loading on cyanobacterial abundance. Warming increased the abundance of bloom‐forming taxa, but in combination with very high nutrient loading resulted in a negative, not positive, interaction. The impact of extreme rainfall events was only apparent in the winter. Stressor gradients and season should be considered as important factors shaping the response to global change.
Objective: Alcohol-related facial flushing occurs in individuals who are unable to metabolize ethanol effectively and is associated with increased cancer risk. This study describes college students' ...understanding of the meaning of flushing for how much alcohol a person should drink and their use of over-the-counter medications and other strategies to reduce its visible effects. Participants: The sample includes 335 White and Asian college students who reported facial flushing after an alcoholic drink. Methods: Students completed an online survey in the spring of their junior year. Results: Most students reported that flushing had no special meaning for drinking or that they did not know what it meant. Six percent reported ever using strategies to hide facial flushing; they were mostly Asian, and those using these strategies drank more alcohol. Conclusions: Findings identify a need for targeted alcohol education with Asian college students who drink alcohol despite experiencing the flushing response.
•Quantitatively assessing the impact of hydrogeological factors on salinization using coupled surface-subsurface model.•Developing indicators to assess coastal aquifer vulnerability.•Coastal aquifer ...vulnerability influenced by permeability, extremely heightened by a low recharge.
Ocean surges cause seawater inundation of coastal inland areas. Subsequently, seawater infiltrates into coastal aquifers and threatens the fresh groundwater resource. The severity of resulting salinization can be affected by hydrogeological factors including aquifer properties and hydrologic conditions, however, little research has been done to assess these effects. To understand the impacts of hydrogeological factors on groundwater salinization, we numerically simulated an ocean-surge inundation event on a two-dimensional conceptual coastal aquifer using a coupled surface-subsurface approach. We varied model permeability (including anisotropy), inland hydraulic gradient, and recharge rate. Three salinization-assessment indicators were developed, based on flushing time, depth of salt penetration, and a combination of the two, weighted flushing time, with which the impact of hydrogeological factors on groundwater vulnerability to salinization were quantitatively assessed. The vulnerability of coastal aquifers increases with increasing isotropic permeability. Low horizontal permeability (kx) and high vertical permeability (kz) lead to high aquifer vulnerability, and high kx and low kz lead to low aquifer vulnerability. Vulnerability decreases with increasing groundwater hydraulic gradient and increasing recharge rate. Additionally, coastal aquifers with a low recharge rate (R ≤ 300 mm yr−1) may be highly vulnerable to ocean-surge inundation. This study shows how the newly introduced indicators can be used to quantitatively assess coastal aquifer vulnerability. The results are important for global vulnerability assessment of coastal aquifers to ocean-surge inundation.
Spring phenology of temperate forest trees has advanced substantially over the last decades due to climate warming, but this advancement is slowing down despite continuous temperature rise. The ...decline in spring advancement is often attributed to winter warming, which could reduce chilling and thus delay dormancy release. However, mechanistic evidence of a phenological response to warmer winter temperatures is missing. We aimed to understand the contrasting effects of warming on plants leaf phenology and to disentangle temperature effects during different seasons. With a series of monthly experimental warming by ca. 2.4°C from late summer until spring, we quantified phenological responses of forest tree to warming for each month separately, using seedlings of four common European tree species. To reveal the underlying mechanism, we tracked the development of dormancy depth under ambient conditions as well as directly after each experimental warming. In addition, we quantified the temperature response of leaf senescence. As expected, warmer spring temperatures led to earlier leaf‐out. The advancing effect of warming started already in January and increased towards the time of flushing, reaching 2.5 days/°C. Most interestingly, however, warming in October had the opposite effect and delayed spring phenology by 2.4 days/°C on average; despite six months between the warming and the flushing. The switch between the delaying and advancing effect occurred already in December. We conclude that not warmer winters but rather the shortening of winter, i.e., warming in autumn, is a major reason for the decline in spring phenology.
Warm temperatures during spring accelerate leaf flushing in temperate trees. But why is this advancing effect declining? We experimentally investigated how leaf‐out dates are impacted by temperatures during the entire preceding non‐growing season, separately for every month. We found that in autumn, before the onset of leaf coloration, temperature has a surprisingly strong impact. Warming during this time delays leaf senescence and the induction of bud dormancy, resulting in a delay of next year's spring leaf phenology.
Radium is widely used to estimate flushing time, submarine groundwater discharge (SGD), and submarine fresh groundwater discharge (SFGD), however there are important sources of uncertainty in current ...methods. Here an improved method is proposed, incorporating all radium quartet information to estimate flushing time, SFGD, SGD, and associated nutrient fluxes during wet and dry seasons in Laizhou Bay, China. Both SGD and SFGD in dry season are comparable to that in wet season, likely due to higher groundwater hydraulic gradients resulting from higher groundwater table and lower mean sea level in dry season. Estimated dry and wet season SFGD are of the same order of magnitude as the annually-averaged Yellow River discharge, highlighting SFGD's importance to the bay environment. Nutrient inputs into Laizhou Bay were estimated for the wet season, suggesting that SGD-derived nutrients are indeed important and significant for coastal environments compared to local river discharge estimates.
•Using radium quartet for simultaneous estimation of flushing time, SGD and SFGD•Both SGD and SFGD in dry season are comparable to that in wet season in Laizhou Bay.•Effects of RSGD were taken into account for calculating SGD driven nutrient fluxes.•SGD-derived nutrients are significantly higher than those from the Yellow River.
Philip Brooks and colleagues discuss evidence linking the alcohol flushing response (predominantly due to ALDH2 deficiency) with a much higher risk of esophageal cancer from alcohol consumption.
Abstract
Pressure flushing is a common technique to restore the storage capacity of reservoirs. However, the low quantity of flushed sediment remains a drawback of pressure flushing. Experimentally, ...the present study used inclined plates upstream of the bottom outlet to increase the flushed sediment in pressure flushing. The variables included the plate width (B), the angel between the vertical line at the outlet center and the normal vector of the inclined plate (α), radial distance of the inclined plates from the orifice center (R), and outlet discharge (Q). The results showed that the flushed sediment significantly enhanced; the quantity of flushed sediment for B = 6.3 cm, α = 60°, R = 8.5 cm, and a Q = 8.34 L/s was 19 times as large as that in the reference test (i.e., without plates). Furthermore, the length, width, and depth of the scour cone in the presence of inclined plates were 3, 2.3, and 3.3 times as high as those in the absence of the inclined plates. Also, equations were developed to predict the volume and dimensions of the scour cone in the presence of inclined plates based on the experimental data. Finally, the importance of the variables was determined using a sensitivity analysis method. Between all considered parameters in this study, the plate distance from the outlet was found to have the highest effect and the plate inclination the lowest effect (three times) in increasing the flushed sediment through the orifice.
Association between drinking and smoking has remained controversial since the association between two studies were influenced by various confounding. Thus, our study aimed to explore the causal ...effect of alcohol consumption and cigarette smoking using alcohol flushing as an instrument variable, which is free from confounders. We analyzed cross-sectional survey data from 2500 Korean young adults (1600 men and 900 women). Alcohol flushing was strongly associated with log transformed alcohol consumption (F = 272). In men, alcohol non-flushers were 1.41 times (95% CI 1.28-1.55) more likely to smoke 100 cigarettes in their lifetime in logistic regression analysis. Alcohol non-flushers were also 1.3 times (95% CI 1.21-1.40) more likely to become daily smokers and 1.39 times (95% CI 1.27-1.51) more likely to be current smokers than alcohol flushers. However, in an IV analysis, no causal relationships between alcohol consumption and smoking status were found. Alcohol consumption, on the other hand, was causally associated with lowering nicotine dependence and former smoking in men. Alcohol consumption determined by alcohol flushing status does not appear to be causally linked to the smoking behavior of young adults. The relationship between alcohol consumption and nicotine dependence and smoking cessation needs further study.
Abstract When encountering favorable reservoirs that have not been drilled along the wellbore trajectory of Shunbei carbonate fracture-cavity reservoirs, deep acid fracturing technology is required ...to communicate with favorable reservoirs and achieve production. Currently, there is no optimized method for designing deep acid fracturing parameters for Shunbei fracture-cavity reservoirs, which results in problems such as failure to communicate with favorable reservoirs after deep acid fracturing or rapid decline in production after communication. To address these issues, this paper establishes a geological feature model for fracture-cavity reservoirs based on the characteristics of Shunbei fracture-cavity reservoirs and proposes a deep acid fracturing fracture parameter optimization approach with production capacity as the goal. Using a multi-field coupled acid fracturing model that can reflect the large leakage characteristics of fracture-cavity reservoirs, the proposed fracture parameters are used to simulate and optimize the scale of pre-flushing liquid and acid liquid. The simulation results show that the desired increase in production can be achieved when the fracture diversion capacity is 30D·cm and the penetration ratio is between 0.1 and 0.3. Furthermore, this paper recommends injecting 450~900 m 3 of pre-flushing liquid to communicate with favorable reservoirs (0.1≤De≤0.2), followed by the injection of 900 m 3 of cross-linked acid and 450 m 3 of gelled acid to construct the fracture diversion capacity through acid corrosion.
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