Aquifers on small islands are at risk of salinization due to low elevations and limited adaptive capacity, and present risks will be exacerbated by climate change. Most studies addressing ...small‐island saltwater intrusion (SWI) have focused on homogeneous sandy islands and one or two hydraulic disturbances. We herein investigate SWI dynamics in a layered, confined island aquifer in response to multiple environmental perturbations related to climate change, with two considered in tandem. Our field and modeling work is based on an island aquifer that provides the drinking water supply for an Indigenous community in Atlantic Canada. Observation well data and electrical resistivity profiles were used to calibrate a numerical model (HydroGeoSphere) of coupled groundwater flow and salt transport. The calibrated model was used to simulate the impacts of climate change including sea‐level rise (SLR), storm surge overtopping, changing aquifer recharge, and erosion. Simulated aquifer conditions were resilient to surges because the confining layer prevented deeper saltwater leaching. However, reduced recharge and erosion resulted in saltwater wedge migration of 170 and 110 m, respectively when considered individually, and up to 295 m (i.e., into the wellfield) when considered together. Despite the confining conditions, SLR resulted in wedge migration up to 55 m as the confining pressures were not sufficient to resist wedge movement. This is the first study to harness an integrated, surface‐subsurface hydrologic model to assess effects of coastal erosion and other hydroclimatic stressors on island aquifers, highlighting that climate change can drive extensive salinization of critical groundwater resources.
Plain Language Summary
Due to their limited resources and adaptive capacity, small islands are highly vulnerable to climate change impacts, including saltwater intrusion. Freshwater needs on small islands are often sourced from small aquifers that are in delicate balance between conditions in the ocean, atmosphere, and land. In this study, we investigate the movement of saltwater into the freshwater aquifer of a small island that provides drinking water resources for an Indigenous First Nation. We consider climatic changes in the ocean (sea‐level rise (SLR), storm surges, and related coastal erosion) and atmosphere (changes to net precipitation) and associated impacts to the island's fresh groundwater resources. We use field data paired with a mathematical model and demonstrate that the pressurized conditions of the layered island aquifer make it more resilient to SLR than unconfined aquifers in sandy islands are. However, the aquifer's freshwater volume is susceptible to coastal erosion and reduced precipitation, particularly when these happen at the same time. Results point to coastal erosion as a potential widespread driver of freshwater loss along eroding portions of the global coastline.
Key Points
A surface‐subsurface numerical model is used to investigate climate change impacts on island groundwater resources used for water supply
The confined aquifer is resilient to storm surges which only salinize the unpumped surficial aquifer before being flushed
Coastal erosion and recharge reductions result in the most saltwater intrusion and can work in tandem to threaten future water supply
Purpose: It is well known that children, adolescents, and young adults with diabetes face numerous obstacles to adherence. Diabetes distress can lead to diabetes burnout, which worsens diabetes ...nonadherence. We initiated diabetes distress screening to determine the impact of diabetes distress on our patients and developed games and animated videos in an attempt to assess diabetes knowledge and decrease visit stress.
Methods: Diabetes patients aged 10 and older were given the two-question diabetes distress screening scale (DDS2) during their routine follow-up visits. Two games were created to play at the beginning of each appointment and two animated medical education videos were created on how to recognize and manage diabetes distress.
Results: A total of 207 patients received DDS2 screening questionnaires. The mean DDS2 score was 5.6 (Type 1, n=178) and 5.5 (Type 2, n=29) out of 12 possible points. Only a weak correlation was found between the DDS2 score and hemoglobin A1C (Type 1:R2=0.34, Type 2:R2=0.18) with essentially no correlation noted between diabetes duration and DDS2 score (Type 1:R2=0.001; Type 2:R2=0.01). Ninety-seven percent of patients liked the “pin the bone on your A1C” game, while 93% enjoyed the medical education quiz game, 80% felt they learned something from it, and 89% felt that it made them more relaxed for their visit.
Conclusions: Diabetes distress can lead to diabetes burnout, thus it is important to identify when present. Our data suggest that distress may sometimes be hidden, hence we should specifically screen for diabetes distress in all our pediatric patients that are tweens and older as no significant correlation was found between DDS2 score, hemoglobin A1C, and duration of diabetes. Therapy can be then directed to ameliorating the stress and burnout associated with living with diabetes while the use of easily created educational games and animated videos can be helpful adjuncts to assess patient knowledge while simultaneously lessening appointment stress.
Disclosure
T.Imai: None. T.Nguyen: None. T.S.Stanic: None. D.Diaz: None. D.Lopez: None. R.Kinman: None.
To evaluate the dose received by the hippocampus among patients undergoing intensity-modulated radiotherapy (IMRT) for nasopharyngeal cancer.
10 patients with biopsy-proven, locally advanced ...nasopharyngeal cancer constituted the study population. The total prescribed dose to the planning target volume (PTV) was 70 Gy (D95%) delivered in 2.12-Gy daily fractions using IMRT. Using established anatomical guidelines, MRI co-registration and the assistance of a board-certified neuroradiologist, the right and left hippocampi were delineated on axial imaging from the CT scan obtained at simulation for each patient beginning at the most anterior portion of the lateral ventricle. IMRT treatment plans were generated without dose-volume constraints to the hippocampus. A range of dose-volume statistics was calculated.
The mean hippocampus volume was 6.01 ± 2.61 cm(3). The mean V20 was 72.2%; V40 was 22.0%; V50 was 10.2%; and V60 was 5.5%. The average mean, minimum and maximum hippocampus doses were 30.27 Gy (range, 19.08-47.99 Gy); 17.54 Gy (range, 11.66-33.17 Gy); and 54.95 Gy (range, 35.59-75.57 Gy), respectively. The hippocampus received a maximum dose exceeding 70 Gy in 30% of cases.
Our dosimetric analysis suggests that, for patients undergoing IMRT for nasopharyngeal cancer, the hippocampus routinely receives significantly high doses.
The hippocampus receives a fair amount of incidental radiation during treatment for nasopharyngeal cancer. Given the importance of this structure with respect to memory and neurocognitive function, consideration should be given to identifying the hippocampus as a critical organ at risk in the IMRT optimization process.
The present study outlines the phenolic composition of methanolic extracts of Digitalis ferruginea and Digitalis lamarckii aerial parts and evaluates their biological activities. The quantification ...of phenolic compounds was carried out by HPLC–DAD analysis. Antioxidant properties were assessed using different assays. Enzyme inhibition was tested on AChE, BChE, α-amylase, α-glucosidase, and tyrosinase. The antimicrobial properties of the extracts were determined using the microdilution method. Genotoxicity of the extracts was assessed on Drosophila melanogaster by comet assay. D. lamarcki extract was richer in phenolic compounds than D. ferruginea, with chlorogenic acid as dominant compound in both D. lamarckii and D. ferruginea extracts (2.99 and 1.30mg/g, respectively). Both extracts showed similar values in terms of antioxidant activity. The extracts showed enzyme inhibitory activity on above-mentioned enzymes and moderate antimicrobial activity (MIC range 0.625–10mg/mL). D. ferruginea extract (20mg/mL) indicated the absence of genotoxicity, while all concentrations of D. lamarckii extract showed significant DNA damage. Antigenotoxic effect was more evident in the group treated with D. lamarckii extract, 80mg/mL (%R=80.3). The results emphasized the biological potential of examined plants and encourage further studies for their potential use as phytopharmaceuticals.
•The methanolic extracts from D. ferruginea and D. lamarckii were obtained.•Tested extracts — high antioxidant activity, rich sources of phenolic compounds•Digitalis species revealed good enzyme inhibitory activity.•The extracts possess moderate antimicrobial activity.•The genotoxic and antigenotoxic potentials of the plants were maintained.
The recently proposed PRFG3 method is extended in order to synthesise an atmospheric boundary layer flow, which can be used as inflow condition for Large Eddy Simulation (LES). Firstly, PRFG3 is used ...for generating homogeneous isotropic and homogeneous anisotropic turbulence fields. Based on the obtained results, the method is applied to generate an atmospheric boundary layer, which is used as inflow condition for a LES of a uniform rough terrain, specified in agreement with the Eurocode. Results are discussed based on the analysis of one and two points statistics of the flow field. Good agreement between the target values used in the inflow generation, the synthetic field and the LES, highlights the soundness of the proposed approach. A PRFG3 implementation is available for download at https://site.unibo.it/cwe-lamc/en.
•The recently proposed PRFG3 method is extended in order to synthesise an atmospheric boundary layer flow.•An Eurocode category III velocity profile is generated and applied as inflow condition of a LES.•The resulting flow field is characterized in terms of turbulence intensities and all nine integral length scales.•The obtained flow field well complies with the target values without need of a posteriori calibration.
A surface ship's wake is composed of several hydrodynamic phenomena. A large part of that wake contains a mixture of air bubbles of various sizes in turbulent water. Eventually, as the wake ages, the ...turbulence subsides and bubbles begin to rise at rates that are determined by their sizes. These bubbles of various sizes and concentrations control the propagation of acoustic signals inside and across a wake. To further our understanding of these phenomena, a series of three continuous-wave (CW)-pulsed signals were transmitted across a wake as the wake aged. Each transmission contained a set of four 0.5-ms-long pulses. The 12 pulses ranged over frequencies from 30 to 140 kHz in 10-kHz steps. The acoustic attenuations across wakes that were due to varying bubble-size densities within the wakes were determined experimentally. From those data, estimates of the bubble densities as functions of the speed of the wake-generating ship, the wake's age, and acoustic frequency were calculated. From the bubble-density results, power-law fits and void fractions are calculated. The attenuation measurements were taken at 7.5-m intervals behind the wake-generating ship and continued for about 2 km. The experiment was run for wakes generated at ship speeds of 12- and 15-kn wakes, and the 15-kn run was repeated for consistence determination. The bubble densities were observed to have power-law forms with varying parameters with the strongest, for early ages, having an exponent of -3.6 and a void fraction of 4 x 10 -7 , and with both diminishing for older wakes, as might be expected.
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