scholarly journals Landscape controls of surface-water/groundwater interactions on shallow outwash lakes: how the long-term groundwater signal overrides interannual variability due to evaporative effects

2021 ◽  
Author(s):  
K. J. Hokanson ◽  
B. J. Rostron ◽  
K. J. Devito ◽  
C. Hopkinson ◽  
C. A. Mendoza
Keyword(s):  
Surface Water ◽  
Interannual Variability ◽  
Short Circuit ◽  
Strong Predictor ◽  
Landscape Position ◽  
Volume Control ◽  
Isotopic Compositions ◽  
Potential Groundwater ◽  
Topographic Positions

AbstractThe spatial and temporal controls on variability of the relative contributions of groundwater within and between flow systems to shallow lakes in the low-relief glaciated Boreal Plains of Canada were evaluated. Eleven lakes located in a coarse glacial outwash, of varying topographic positions and potential groundwater contributing areas, were sampled annually for stable O and H isotope ratios over the course of 8 years. It was demonstrated that landscape position is the dominant control over relative groundwater contributions to these lakes and the spatial pattern of the long-term isotopic compositions attributed to groundwater overrides interannual variability due to evaporative effects. Lakes at low landscape positions with large potential groundwater capture areas have relatively higher and more consistent groundwater contributions and low interannual variability of isotopic composition. Isolated lakes high in the landscape experience high interannual variability as they have little to no groundwater input to buffer the volumetric or isotopic changes caused by evaporation and precipitation. An alternative explanation that lake morphometry (area and volume) control long-term isotopic compositions is tested and subsequently refuted. Landscape position within coarse outwash is a strong predictor for relative groundwater input; however, surface-water connections can short circuit groundwater pathways and confound the signal. A hydrogeological case study for three of the study lakes is used to contextualize and further demonstrate these results.

Modelling the Effects of Acid Deposition: Estimation of Long-Term Water Quality Responses in Forested Catchments in Finland

1988 ◽  
Vol 19 (2) ◽  
pp. 99-120 ◽  
Author(s):  
A. Lepistö ◽  
P. G. Whitehead ◽  
C. Neal ◽  
B. J. Cosby
Keyword(s):  
Water Quality ◽  
Surface Water ◽  
Base Cations ◽  
Surface Water Quality ◽  
Mineral Weathering ◽  
Co2 Solubility ◽  
Forested Catchments ◽  
Deposition Rates ◽  
Magic Model

A modelling study has been undertaken to investigate long-term changes in surface water quality in two contrasting forested catchments; Yli-Knuutila, with high concentrations of base cations and sulphate, in southern Finland; and organically rich, acid Liuhapuro in eastern Finland. The MAGIC model is based on the assumption that certain chemical processes (anion retention, cation exchange, primary mineral weathering, aluminium dissolution and CO2 solubility) in catchment soils are likely keys to the responses of surface water quality to acidic deposition. The model was applied for the first time to an organically rich catchment with high quantities of humic substances. The historical reconstruction of water quality at Yli-Knuutila indicates that the catchment surface waters have lost about 90 μeq l−1 of alkalinity in 140 years, which is about 60% of their preacidification alkalinity. The model reproduces the declining pH levels of recent decades as indicated by paleoecological analysis. Stream acidity trends are investigated assuming two scenarios for future deposition. Assuming deposition rates are maintained in the future at 1984 levels, the model indicates that stream pH is likely to continue to decline below presently measured levels. A 50% reduction in deposition rates would likely result in an increase in pH and alkalinity of the stream, although not to estimated preacidification levels. Because of the high load of organic acids to the Liuhapuro stream it has been acid before atmospheric pollution; a decline of 0.2 pH-units was estimated with increasing leaching of base cations from the soil despite the partial pH buffering of the system by organic compounds.

Inner Retinal Morphology and Visual Outcomes in Idiopathic Epiretinal Membrane Surgery: A Retrospective Optical Coherence Tomography Study

2021 ◽  
pp. 247412642198961
Author(s):  
Ioannis S. Dimopoulos ◽  
Michael Dollin
Keyword(s):  
Optical Coherence Tomography ◽  
Epiretinal Membrane ◽  
Strong Predictor ◽  
Plexiform Layer ◽  
Inner Plexiform Layer ◽  
Optical Coherence ◽  
Visual Outcomes ◽  
Retinal Pathology

Purpose: Epiretinal membrane (ERM) is a common retinal finding for patients older than 50 years. Disorganization of the retinal inner layers (DRIL) has emerged as a novel predictor of poor visual acuity (VA) in eyes with inner retinal pathology. The aim of our study is to correlate preoperative DRIL with visual outcomes after ERM surgery. Methods: Medical records and optical coherence tomography (OCT) images of 81 pseudophakic patients who underwent treatment of idiopathic ERM were reviewed. Preoperative DRIL on OCT was correlated with VA at baseline and at 3 and 6 months after ERM surgery. DRIL was defined as the loss of distinction between the ganglion cell–inner plexiform layer complex, inner nuclear layer, and outer plexiform layer. DRIL severity was based on its extent within the central 2-mm region of a transfoveal B-scan (absent/mild: <one-third, severe: >one-third horizontal width). Results: Review of preoperative OCT showed severe DRIL in 41% and absent/mild DRIL in 59%. Severe DRIL was associated with worse baseline VA ( P < .001). Preoperative VA and DRIL status at baseline were both predictors of postoperative VA at follow-up time points ( P < .001). Severe DRIL was associated with significantly less improvement in VA at 6 months (–0.23 logMAR for absent/mild vs –0.14 for severe DRIL). Conclusions: Presence of severe preoperative DRIL correlates with worse baseline VA in patients with ERM and reduced VA improvement at 6 months. DRIL can be a strong predictor of long-term poor visual outcomes in ERM surgery.

scholarly journals Surface Water Temperature Predictions at a Mid-Latitude Reservoir under Long-Term Climate Change Impacts Using a Deep Neural Network Coupled with a Transfer Learning Approach

Water ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1109
Author(s):  
Nobuaki Kimura ◽  
Kei Ishida ◽  
Daichi Baba
Keyword(s):  
Climate Change ◽  
Surface Water ◽  
Water Temperature ◽  
Transfer Learning ◽  
Air Temperature ◽  
Climate Models ◽  
Temporal Variations ◽  
Training Data ◽  
Surface Water Temperature

Long-term climate change may strongly affect the aquatic environment in mid-latitude water resources. In particular, it can be demonstrated that temporal variations in surface water temperature in a reservoir have strong responses to air temperature. We adopted deep neural networks (DNNs) to understand the long-term relationships between air temperature and surface water temperature, because DNNs can easily deal with nonlinear data, including uncertainties, that are obtained in complicated climate and aquatic systems. In general, DNNs cannot appropriately predict unexperienced data (i.e., out-of-range training data), such as future water temperature. To improve this limitation, our idea is to introduce a transfer learning (TL) approach. The observed data were used to train a DNN-based model. Continuous data (i.e., air temperature) ranging over 150 years to pre-training to climate change, which were obtained from climate models and include a downscaling model, were used to predict past and future surface water temperatures in the reservoir. The results showed that the DNN-based model with the TL approach was able to approximately predict based on the difference between past and future air temperatures. The model suggested that the occurrences in the highest water temperature increased, and the occurrences in the lowest water temperature decreased in the future predictions.

scholarly journals Management of Myositis-Associated Interstitial Lung Disease

Medicina ◽  
2021 ◽  
Vol 57 (4) ◽  
pp. 347
Author(s):  
Tomoyuki Fujisawa
Keyword(s):  
Interstitial Lung Disease ◽  
Lung Disease ◽  
Current Knowledge ◽  
Strong Predictor ◽  
Calcineurin Inhibitors ◽  
Pulmonary Involvement ◽  
Trna Synthetase ◽  
Evidence Based Guidelines ◽  
Substantial Heterogeneity

Idiopathic inflammatory myopathies, including polymyositis (PM), dermatomyositis (DM), and clinically amyopathic DM (CADM), are a diverse group of autoimmune diseases characterized by muscular involvement and extramuscular manifestations. Interstitial lung disease (ILD) has major pulmonary involvement and is associated with increased mortality in PM/DM/CADM. The management of PM-/DM-/CADM-associated ILD (PM/DM/CADM-ILD) requires careful evaluation of the disease severity and clinical subtype, including the ILD forms (acute/subacute or chronic), because of the substantial heterogeneity of their clinical courses. Recent studies have highlighted the importance of myositis-specific autoantibodies’ status, especially anti-melanoma differentiation-associated gene 5 (MDA5) and anti-aminoacyl tRNA synthetase (ARS) antibodies, in order to evaluate the clinical phenotypes and treatment of choice for PM/DM/CADM-ILD. Because the presence of the anti-MDA5 antibody is a strong predictor of a worse prognosis, combination treatment with glucocorticoids (GCs) and calcineurin inhibitors (CNIs; tacrolimus (TAC) or cyclosporin A (CsA)) is recommended for patients with anti-MDA5 antibody-positive DM/CADM-ILD. Rapidly progressive DM/CADM-ILD with the anti-MDA5 antibody is the most intractable condition, which requires immediate combined immunosuppressive therapy with GCs, CNIs, and intravenous cyclophosphamide. Additional salvage therapies (rituximab, tofacitinib, and plasma exchange) should be considered for patients with refractory ILD. Patients with anti-ARS antibody-positive ILD respond better to GC treatment, but with frequent recurrence; thus, GCs plus immunosuppressants (TAC, CsA, azathioprine, and mycophenolate mofetil) are often needed in order to achieve favorable long-term disease control. PM/DM/CADM-ILD management is still a therapeutic challenge for clinicians, as evidence-based guidelines do not exist to help with management decisions. A few prospective clinical trials have been recently reported regarding the treatment of PM/DM/CADM-ILD. Here, the current knowledge on the pharmacologic managements of PM/DM/CADM-ILD was mainly reviewed.

Toxicity analysis of surface water in the Lower Don basin in Rostov-on-Don City by long-term bioassay data

2015 ◽  
Vol 42 (1) ◽  
pp. 70-77
Author(s):  
E. N. Bakaeva ◽  
A. M. Nikanorov ◽  
N. A. Ignatova
Keyword(s):  
Surface Water ◽  
Toxicity Analysis ◽  
Bioassay Data

Stable isotopes in planktonic and benthic foraminifera from Arctic Ocean surface sediments

1988 ◽  
Vol 25 (5) ◽  
pp. 701-709 ◽  
Author(s):  
A. E. Aksu ◽  
G. Vilks
Keyword(s):  
Surface Water ◽  
Arctic Ocean ◽  
Sea Water ◽  
Ocean Surface ◽  
The Arctic ◽  
Size Fractions ◽  
Isotopic Compositions ◽  
Isotopic Analyses ◽  
Stable Isotopic ◽  
Surface Water Salinity

Oxygen and carbon isotopic analyses have been performed on the tests of Planulina wuellerstorfi and three size fractions of sinistral Neogloboquadrina pachyderma recovered from 33 Arctic Ocean surface-sediment samples. Stable isotopic compositions of N. pachyderma are found to be dependent on the test size: larger specimens show considerable enrichment in both δ18O and δ18C. The difference between the isotopic compositions of the 63–125 and 125–250 μm size fractions in N. pachyderma can be explained by biogenic fractionation effects during foraminiferal test growth. Larger (250–500 μm) N. pachyderma displayed accretions of secondary calcite, i.e., the outermost shell contained significant amounts of inorganically precipitated magnesium calcite. Thus, larger foraminifera may not be suited for down-core stable isotopic studies. There is a difference of ~2‰ between δ18O values of surface samples from the eastern and western Arctic Ocean, reflecting large differences between surface-water salinity in these regions. Therefore, oxygen isotopic data may have limited use as a chronostratigraphic tool in down-core studies in the Arctic Ocean, but we can use them to infer past variations in surface-water salinities. Planulina wuellerstorfi also showed depletions of both δ18O and δ18C in its calcite tests relative to calcite precipitated in isotopic equilibrium with ambient sea water; these depletions ranged from −0.8 to −0.9‰ in δ18Oand −1.2 to −0.9‰ in δ18C. This taxon is found to deposit its shell very close to the δ18C of ΣCO2 of bottom waters.

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