Tidal Marshes across a Chesapeake Bay Subestuary Are Not Keeping up with Sea-Level Rise
Beckett, Leah H.; Baldwin, Andrew H.; Kearney, Michael S.
2016-01-01
Sea-level rise is a major factor in wetland loss worldwide, and in much of Chesapeake Bay (USA) the rate of sea-level rise is higher than the current global rate of 3.2 mm yr-1 due to regional subsidence. Marshes along estuarine salinity gradients differ in vegetation composition, productivity, decomposition pathways, and sediment dynamics, and may exhibit different responses to sea-level rise. Coastal marshes persist by building vertically at rates at or exceeding regional sea-level rise. In one of the first studies to examine elevation dynamics across an estuarine salinity gradient, we installed 15 surface elevation tables (SET) and accretion marker-horizon plots (MH) in tidal freshwater, oligohaline, and brackish marshes across a Chesapeake Bay subestuary. Over the course of four years, wetlands across the subestuary decreased 1.8 ± 2.7 mm yr-1 in elevation on average, at least 5 mm yr-1 below that needed to keep pace with global sea-level rise. Elevation change rates did not significantly differ among the marshes studied, and ranged from -9.8 ± 6.9 to 4.5 ± 4.3 mm yr-1. Surface accretion of deposited mineral and organic matter was uniformly high across the estuary (~9–15 mm yr-1), indicating that elevation loss was not due to lack of accretionary input. Position in the estuary and associated salinity regime were not related to elevation change or surface matter accretion. Previous studies have focused on surface elevation change in marshes of uniform salinity (e.g., salt marshes); however, our findings highlight the need for elevation studies in marshes of all salinity regimes and different geomorphic positions, and warn that brackish, oligohaline, and freshwater tidal wetlands may be at similarly high risk of submergence in some estuaries. PMID:27467784
Dickinson, Gary H; Ivanina, Anna V; Matoo, Omera B; Pörtner, Hans O; Lannig, Gisela; Bock, Christian; Beniash, Elia; Sokolova, Inna M
2012-01-01
Rising levels of atmospheric CO(2) lead to acidification of the ocean and alter seawater carbonate chemistry, which can negatively impact calcifying organisms, including mollusks. In estuaries, exposure to elevated CO(2) levels often co-occurs with other stressors, such as reduced salinity, which enhances the acidification trend, affects ion and acid-base regulation of estuarine calcifiers and modifies their response to ocean acidification. We studied the interactive effects of salinity and partial pressure of CO(2) (P(CO2)) on biomineralization and energy homeostasis in juveniles of the eastern oyster, Crassostrea virginica, a common estuarine bivalve. Juveniles were exposed for 11 weeks to one of two environmentally relevant salinities (30 or 15 PSU) either at current atmospheric P(CO2) (∼400 μatm, normocapnia) or P(CO2) projected by moderate IPCC scenarios for the year 2100 (∼700-800 μatm, hypercapnia). Exposure of the juvenile oysters to elevated P(CO2) and/or low salinity led to a significant increase in mortality, reduction of tissue energy stores (glycogen and lipid) and negative soft tissue growth, indicating energy deficiency. Interestingly, tissue ATP levels were not affected by exposure to changing salinity and P(CO2), suggesting that juvenile oysters maintain their cellular energy status at the expense of lipid and glycogen stores. At the same time, no compensatory upregulation of carbonic anhydrase activity was found under the conditions of low salinity and high P(CO2). Metabolic profiling using magnetic resonance spectroscopy revealed altered metabolite status following low salinity exposure; specifically, acetate levels were lower in hypercapnic than in normocapnic individuals at low salinity. Combined exposure to hypercapnia and low salinity negatively affected mechanical properties of shells of the juveniles, resulting in reduced hardness and fracture resistance. Thus, our data suggest that the combined effects of elevated P(CO2) and fluctuating salinity may jeopardize the survival of eastern oysters because of weakening of their shells and increased energy consumption.
Tidal Marshes across a Chesapeake Bay Subestuary Are Not Keeping up with Sea-Level Rise
DOE Office of Scientific and Technical Information (OSTI.GOV)
Beckett, Leah H.; Baldwin, Andrew H.; Kearney, Michael S.
Sea-level rise is a major factor in wetland loss worldwide, and inmuch of Chesapeake Bay (USA) the rate of sea-level rise is higher than the current global rate of 3.2 mmyr -1 due to regional subsidence.Marshes along estuarine salinity gradients differ in vegetation composition, productivity, decomposition pathways, and sediment dynamics, andmay exhibit different responses to sea-level rise. Coastal marshes persist by building vertically at rates at or exceeding regional sea-level rise. In one of the first studies to examine elevation dynamics across an estuarine salinity gradient, we installed 15 surface elevation tables (SET) and accretion marker-horizon plots (MH) in tidalmore » freshwater, oligohaline, and brackish marshes across a Chesapeake Bay subestuary. Over the course of four years, wetlands across the subestuary decreased 1.8 ± 2.7 mmyr -1 in elevation on average, at least 5 mmyr -1 below that needed to keep pace with global sea-level rise. Elevation change rates did not significantly differ among themarshes studied, and ranged from-9.8 ± 6.9 to 4.5 ± 4.3 mmyr -1. Surface accretion of depositedmineral and organic matter was uniformly high across the estuary (~9–15 mmyr -1), indicating that elevation loss was not due to lack of accretionary input. Position in the estuary and associated salinity regime were not related to elevation change or surface matter accretion. In conclusion, previous studies have focused on surface elevation change inmarshes of uniformsalinity (e.g., salt marshes); however, our findings highlight the need for elevation studies inmarshes of all salinity regimes and different geomorphic positions, and warn that brackish, oligohaline, and freshwater tidal wetlands may be at similarly high risk of submergence in some estuaries.« less
Tidal Marshes across a Chesapeake Bay Subestuary Are Not Keeping up with Sea-Level Rise
Beckett, Leah H.; Baldwin, Andrew H.; Kearney, Michael S.; ...
2016-07-28
Sea-level rise is a major factor in wetland loss worldwide, and inmuch of Chesapeake Bay (USA) the rate of sea-level rise is higher than the current global rate of 3.2 mmyr -1 due to regional subsidence.Marshes along estuarine salinity gradients differ in vegetation composition, productivity, decomposition pathways, and sediment dynamics, andmay exhibit different responses to sea-level rise. Coastal marshes persist by building vertically at rates at or exceeding regional sea-level rise. In one of the first studies to examine elevation dynamics across an estuarine salinity gradient, we installed 15 surface elevation tables (SET) and accretion marker-horizon plots (MH) in tidalmore » freshwater, oligohaline, and brackish marshes across a Chesapeake Bay subestuary. Over the course of four years, wetlands across the subestuary decreased 1.8 ± 2.7 mmyr -1 in elevation on average, at least 5 mmyr -1 below that needed to keep pace with global sea-level rise. Elevation change rates did not significantly differ among themarshes studied, and ranged from-9.8 ± 6.9 to 4.5 ± 4.3 mmyr -1. Surface accretion of depositedmineral and organic matter was uniformly high across the estuary (~9–15 mmyr -1), indicating that elevation loss was not due to lack of accretionary input. Position in the estuary and associated salinity regime were not related to elevation change or surface matter accretion. In conclusion, previous studies have focused on surface elevation change inmarshes of uniformsalinity (e.g., salt marshes); however, our findings highlight the need for elevation studies inmarshes of all salinity regimes and different geomorphic positions, and warn that brackish, oligohaline, and freshwater tidal wetlands may be at similarly high risk of submergence in some estuaries.« less
Hussin, Sayed; Geissler, Nicole; El-Far, Mervat M M; Koyro, Hans-Werner
2017-09-01
The effect of water salinity on plant growth and photosynthetic traits of Stevia rebaudiana was investigated to determine its level and mechanisms of salinity tolerance. It was also attempted to assess how short-term elevated CO 2 concentration would influence the boundaries and mechanisms of its photosynthetic capacity. The plants were grown in gravel/hydroponic system under controlled greenhouse conditions and irrigated with four different salinity levels (0, 25, 50 and 100 mol m -3 NaCl). Low salinity did not significantly alter the plant fresh weight, which was substantially decreased by 67% at high salinity treatment. Salinity tolerance threshold was reached at 50 mol m -3 NaCl while C50 was between 50 and 100 mol m -3 NaCl, indicating that S. rebaudiana is a moderate salt tolerant species. Salt-induced growth reduction was apparently linked to a significant decline of about 47% in the photosynthetic rates (A net ) at high salinity treatment, leading consequently to a disequilibrium between CO 2 -assimilation and electron transport rates (indicated by enhanced ETR max /A gross ratio). Elevated atmospheric CO 2 enhanced CO 2 assimilation rates by 65% and 80% for control and high-salt-stressed plants respectively, likely due to significant increases in intercellular CO 2 concentration (indicated by enhanced C i /C a ). The priority for Stevia under elevated atmospheric CO 2 was not to save water but to maximize photosynthesis so that the PWUE was progressively improved and the threat of oxidative stress was diminished (decline in ETR max /A gross ). The results imply that elevated CO 2 level could ameliorate some of the detrimental effects of salinity, conferring higher tolerance and survival of S. rebaudiana, a highlydesired feature with the forthcoming era of global changes. Copyright © 2017 Elsevier Masson SAS. All rights reserved.
Spatial variability of sugarcane yields in relation to soil salinity in Louisiana
USDA-ARS?s Scientific Manuscript database
High soil salinity levels have been documented to negatively impact sugarcane yields. Tests were conducted in commercial sugarcane fields in South Louisiana in 2009-2010 to determine if elevated soil salinity levels resulting from salt water intrusion from several recent hurricanes was having a neg...
Cherry, J.A.; McKee, K.L.; Grace, J.B.
2009-01-01
1. Sea-level rise, one indirect consequence of increasing atmospheric CO2, poses a major challenge to long-term stability of coastal wetlands. An important question is whether direct effects of elevated CO 2 on the capacity of marsh plants to accrete organic material and to maintain surface elevations outweigh indirect negative effects of stressors associated with sea-level rise (salinity and flooding). 2. In this study, we used a mesocosm approach to examine potential direct and indirect effects of atmospheric CO2 concentration, salinity and flooding on elevation change in a brackish marsh community dominated by a C3 species, Schoenoplectus americanus, and a C4 grass, Spartina patens. This experimental design permitted identification of mechanisms and their role in controlling elevation change, and the development of models that can be tested in the field. 3. To test hypotheses related to CO2 and sea-level rise, we used conventional anova procedures in conjunction with structural equation modelling (SEM). SEM explained 78% of the variability in elevation change and showed the direct, positive effect of S. americanus production on elevation. The SEM indicated that C3 plant response was influenced by interactive effects between CO2 and salinity on plant growth, not a direct CO2 fertilization effect. Elevated CO2 ameliorated negative effects of salinity on S. americanus and enhanced biomass contribution to elevation. 4. The positive relationship between S. americanus production and elevation change can be explained by shoot-base expansion under elevated CO 2 conditions, which led to vertical soil displacement. While the response of this species may differ under other environmental conditions, shoot-base expansion and the general contribution of C3 plant production to elevation change may be an important mechanism contributing to soil expansion and elevation gain in other coastal wetlands. 5. Synthesis. Our results revealed previously unrecognized interactions and mechanisms contributing to marsh elevation change, including amelioration of salt stress by elevated CO2 and the importance of plant production and shoot-base expansion for elevation gain. Identification of biological processes contributing to elevation change is an important first step in developing comprehensive models that permit more accurate predictions of whether coastal marshes will persist with continued sea-level rise or become submerged. ?? 2008 The Authors.
Sgherri, Cristina; Pérez-López, Usue; Micaelli, Francesco; Miranda-Apodaca, Jon; Mena-Petite, Amaia; Muñoz-Rueda, Alberto; Quartacci, Mike Frank
2017-06-01
Both salt stress and high CO 2 level, besides influencing secondary metabolism, can affect oxidative status of plants mainly acting in an opposite way with salinity provoking oxidative stress and elevated CO 2 alleviating it. The aim of the present work was to study the changes in the composition of phenolic acids and flavonoids as well as in the antioxidant activity in two differently pigmented lettuce cvs (green or red leaf) when submitted to salinity (200 mM NaCl) or elevated CO 2 (700 ppm) or to their combination in order to evaluate how a future global change can affect lettuce quality. Following treatments, the red cv. always maintained higher levels of antioxidant secondary metabolites as well as antioxidant activity, proving to be more responsive to altered environmental conditions than the green one. Overall, these results suggest that the application of moderate salinity or elevated CO 2 , alone or in combination, can induce the production of some phenolics that increase the health benefits of lettuce. In particular, moderate salinity was able to induce the synthesis of the flavonoids quercetin, quercetin-3-O-glucoside, quercetin-3-O-glucuronide and quercitrin. Phenolics-enrichment as well as a higher antioxidant capacity were also observed under high CO 2 with the red lettuce accumulating cyanidin, free chlorogenic acid, conjugated caffeic and ferulic acid as well as quercetin, quercetin-3-O-glucoside, quercetin-3-O-glucuronide, luteolin-7-O-glucoside, rutin, quercitrin and kaempferol. When salinity was present in combination with elevated CO 2 , reduction in yield was prevented and a higher presence of phenolic compounds, in particular luteolin, was observed compared to salinity alone. Copyright © 2017 Elsevier Masson SAS. All rights reserved.
Schile, Lisa M; Callaway, John C; Morris, James T; Stralberg, Diana; Parker, V Thomas; Kelly, Maggi
2014-01-01
Tidal marshes maintain elevation relative to sea level through accumulation of mineral and organic matter, yet this dynamic accumulation feedback mechanism has not been modeled widely in the context of accelerated sea-level rise. Uncertainties exist about tidal marsh resiliency to accelerated sea-level rise, reduced sediment supply, reduced plant productivity under increased inundation, and limited upland habitat for marsh migration. We examined marsh resiliency under these uncertainties using the Marsh Equilibrium Model, a mechanistic, elevation-based soil cohort model, using a rich data set of plant productivity and physical properties from sites across the estuarine salinity gradient. Four tidal marshes were chosen along this gradient: two islands and two with adjacent uplands. Varying century sea-level rise (52, 100, 165, 180 cm) and suspended sediment concentrations (100%, 50%, and 25% of current concentrations), we simulated marsh accretion across vegetated elevations for 100 years, applying the results to high spatial resolution digital elevation models to quantify potential changes in marsh distributions. At low rates of sea-level rise and mid-high sediment concentrations, all marshes maintained vegetated elevations indicative of mid/high marsh habitat. With century sea-level rise at 100 and 165 cm, marshes shifted to low marsh elevations; mid/high marsh elevations were found only in former uplands. At the highest century sea-level rise and lowest sediment concentrations, the island marshes became dominated by mudflat elevations. Under the same sediment concentrations, low salinity brackish marshes containing highly productive vegetation had slower elevation loss compared to more saline sites with lower productivity. A similar trend was documented when comparing against a marsh accretion model that did not model vegetation feedbacks. Elevation predictions using the Marsh Equilibrium Model highlight the importance of including vegetation responses to sea-level rise. These results also emphasize the importance of adjacent uplands for long-term marsh survival and incorporating such areas in conservation planning efforts.
Dickinson, Gary H; Matoo, Omera B; Tourek, Robert T; Sokolova, Inna M; Beniash, Elia
2013-07-15
Ocean acidification due to increasing atmospheric CO2 concentrations results in a decrease in seawater pH and shifts in the carbonate chemistry that can negatively affect marine organisms. Marine bivalves such as the hard-shell clam, Mercenaria mercenaria, serve as ecosystem engineers in estuaries and coastal zones of the western Atlantic and, as for many marine calcifiers, are sensitive to the impacts of ocean acidification. In estuaries, the effects of ocean acidification can be exacerbated by low buffering capacity of brackish waters, acidic inputs from freshwaters and land, and/or the negative effects of salinity on the physiology of organisms. We determined the interactive effects of 21 weeks of exposure to different levels of CO2 (~395, 800 and 1500 μatm corresponding to pH of 8.2, 8.1 and 7.7, respectively) and salinity (32 versus 16) on biomineralization, shell properties and energy metabolism of juvenile hard-shell clams. Low salinity had profound effects on survival, energy metabolism and biomineralization of hard-shell clams and modulated their responses to elevated PCO2. Negative effects of low salinity in juvenile clams were mostly due to the strongly elevated basal energy demand, indicating energy deficiency, that led to reduced growth, elevated mortality and impaired shell maintenance (evidenced by the extensive damage to the periostracum). The effects of elevated PCO2 on physiology and biomineralization of hard-shell clams were more complex. Elevated PCO2 (~800-1500 μatm) had no significant effects on standard metabolic rates (indicative of the basal energy demand), but affected growth and shell mechanical properties in juvenile clams. Moderate hypercapnia (~800 μatm PCO2) increased shell and tissue growth and reduced mortality of juvenile clams in high salinity exposures; however, these effects were abolished under the low salinity conditions or at high PCO2 (~1500 μatm). Mechanical properties of the shell (measured as microhardness and fracture toughness of the shells) were negatively affected by elevated CO2 alone or in combination with low salinity, which may have important implications for protection against predators or environmental stressors. Our data indicate that environmental salinity can strongly modulate responses to ocean acidification in hard-shell clams and thus should be taken into account when predicting the effects of ocean acidification on estuarine bivalves.
James A. Allen; Jim L. Chambers; S. Reza Pezeshki
1997-01-01
Taxodium distichum var.distichum) subjected to flooding with saline water were evaluated in this study. Ten of the families were from coastal sites in Louisiana and Alabama, USA that have elevated levels of soil-water salinity. The other five families were from inland, freshwater sites in Louisiana. Seedlings from all families...
Saltwater intrusion coupled with drought accelerates carbon loss from a brackish coastal wetland
NASA Astrophysics Data System (ADS)
Wilson, B.; Troxler, T.
2017-12-01
Coastal wetlands, such as the Everglades, are critical ecosystems for blue carbon (C) storage, yet this storage capacity is vulnerable to environmental change, such as saltwater intrusion and altered hydrology. Saltwater intrusion can stress vegetation and bring new metabolites for microbial respiration, thereby altering the C cycle. Drought can reduce the depth of water covering the wetland soil, and, in extreme cases, lead to exposed soil surface. This increases oxygen levels, thus speeding up C decomposition and potentially leading to peat collapse. The combined effects of both saltwater intrusion and drought on coastal marshes, however, are still uncertain, but recent evidence suggests that saltwater intrusion accelerates C loss from wetlands when coupled with drought. Our objective was to determine the change in CO2 flux, decomposition, root and shoot production, and elevation in a brackish water marsh under conditions of drought and elevated salinity. During the onset of drought, soil CO2 efflux increased by 124% and 237% in the ambient and elevated salinity treatments, respectively, compared to the control. Within one month, elevated salinity decreased net ecosystem production (NEP) by 40%, while after 6 months it had decreased by 85%. During the onset of the drought, there was no difference in NEP with ambient salinity between the inundated and exposed monoliths (-3.4 ± 0.8 vs. -4.2 ± 2.0 μmol CO2 m-2 s-1, respectively). However, drought conditions in the elevated salinity treatment resulted in more CO2 release in the exposed monoliths than the inundated monoliths (1.5 ± 0.4 vs. -0.5 ± 0.3 μmol CO2 m-2 s-1, respectively). Elevation change collected at the end of the experiment will allow us to test if elevated salinity combined with drought contributes to peat collapse, and what mechanisms of ecosystem C cycling has the greatest influence. While the restoration of water flows to the southern Everglades is hypothesized to mitigate the periods of drought and slow down saltwater intrusion, this restoration has not occurred yet. Given accelerating sea level rise, increasing frequencies of saltwater intrusion coupled with drought could accelerate C loss from these coastal marshes.
Middleton, Beth A.; McKee, Karen L.
2012-01-01
Higher atmospheric concentrations of CO2 can offset the negative effects of flooding or salinity on plant species, but previous studies have focused on mature, rather than regenerating vegetation. This study examined how interacting environments of CO2, water regime, and salinity affect seed germination and seedling biomass of floating freshwater marshes in the Mississippi River Delta, which are dominated by C3 grasses, sedges, and forbs. Germination density and seedling growth of the dominant species depended on multifactor interactions of CO2 (385 and 720 μl l-1) with flooding (drained, +8-cm depth, +8-cm depth-gradual) and salinity (0, 6% seawater) levels. Of the three factors tested, salinity was the most important determinant of seedling response patterns. Species richness (total = 19) was insensitive to CO2. Our findings suggest that for freshwater marsh communities, seedling response to CO2 is species-specific and secondary to salinity and flooding effects. Elevated CO2 did not ameliorate flooding or salinity stress. Consequently, climate-related changes in sea level or human-caused alterations in hydrology may override atmospheric CO2 concentrations in driving shifts in this plant community. The results of this study suggest caution in making extrapolations from species-specific responses to community-level predictions without detailed attention to the nuances of multifactor responses.
Modeling and Analysis of Sea-level Rise Impacts on Salinity in the Lower St. Johns River
NASA Astrophysics Data System (ADS)
Bacopoulos, P.
2015-12-01
There is deliberate attention being paid to studying sea-level rise impacts on the lower St. Johns River, a drowned coastal plain-type estuary with low topographic drive, located in northeastern Florida. One area of attention is salinity in the river, which influences the entire food web, including sea and marsh grasses, juvenile crustaceans and fishes, wading birds and migratory waterfowl, marine mammals and other predator animals. It is expected that elevated ocean levels will increase the salinity of the estuarine waters, leading to deleterious effects on dependent species of the river biology. The objective of the modeling and analysis was: 1) to establish baseline conditions of salinity for the lower St. Johns River; and 2) to examine future conditions of salinity, as impacted by sea-level rise. Establishing baseline conditions entailed validation of the model for present-day salinity in the lower St. Johns River via comparison to available data. Examining future conditions entailed application of the model for sea-level rise scenarios, with comparison to the baseline conditions, for evaluation of sea-level rise impacts on salinity. While the central focus was on the physics of sea-level rise impacts on salinity, some level of salinity-biological assessment was conducted to identify sea-level rise/salinity thresholds, as related to negatively impacting different species of the river biology.
Varying Inundation Regimes Differentially Affect Natural and ...
Climate change is altering sea-level rise rates and precipitation patterns worldwide. Coastal wetlands are vulnerable to these changes. System responses to stressors are important for resource managers and environmental stewards to understand in order to best manage them. Thin layer sand or sediment application to drowning and eroding marshes is one approach to build elevation and resilience. The above- and below-ground structure, soil carbon dioxide emissions, and pore water constituents in vegetated natural marsh sediments and sand-amended sediments were examined at varying inundation regimes between mean sea level and mean high water (0.82 m NAVD88 to 1.49 m NAVD88) in a field experiment at Laws Point, part of the Plum Island Sound Estuary (MA). Significantly lower salinities, pH, sulfides, phosphates, and ammonium were measured in the sand-amended sediments than in the natural sediments. In natural sediments there was a pattern of increasing salinity with increasing elevation while in the sand-amended sediments the trend was reversed, showing decreasing salinity with increasing elevation. Sulfide concentrations generally increased from low to high inundation with highest concentrations at the highest inundation (i.e., at the lowest elevations). High pore water phosphate concentrations were measured at low elevations in the natural sediments, but the sand-amended treatments had mostly low concentrations of phosphate and no consistent pattern with elevation. A
Miller, Seth H; Zarate, Sonia; Smith, Edmund H; Gaylord, Brian; Hosfelt, Jessica D; Hill, Tessa M
2014-01-01
Future climate change is predicted to alter the physical characteristics of oceans and estuaries, including pH, temperature, oxygen, and salinity. Investigating how species react to the influence of such multiple stressors is crucial for assessing how future environmental change will alter marine ecosystems. The timing of multiple stressors can also be important, since in some cases stressors arise simultaneously, while in others they occur in rapid succession. In this study, we investigated the effects of elevated pCO2 on oxygen consumption by larvae of the intertidal porcelain crab Petrolisthes cinctipes when exposed to subsequent salinity stress. Such an exposure mimics how larvae under future acidified conditions will likely experience sudden runoff events such as those that occur seasonally along portions of the west coast of the U.S. and in other temperate systems, or how larvae encounter hypersaline waters when crossing density gradients via directed swimming. We raised larvae in the laboratory under ambient and predicted future pCO2 levels (385 and 1000 µatm) for 10 days, and then moved them to seawater at ambient pCO2 but with decreased, ambient, or elevated salinity, to monitor their respiration. While larvae raised under elevated pCO2 or exposed to stressful salinity conditions alone did not exhibit higher respiration rates than larvae held in ambient conditions, larvae exposed to elevated pCO2 followed by stressful salinity conditions consumed more oxygen. These results show that even when multiple stressors act sequentially rather than simultaneously, they can retain their capacity to detrimentally affect organisms.
Miller, Seth H.; Zarate, Sonia; Smith, Edmund H.; Gaylord, Brian; Hosfelt, Jessica D.; Hill, Tessa M.
2014-01-01
Future climate change is predicted to alter the physical characteristics of oceans and estuaries, including pH, temperature, oxygen, and salinity. Investigating how species react to the influence of such multiple stressors is crucial for assessing how future environmental change will alter marine ecosystems. The timing of multiple stressors can also be important, since in some cases stressors arise simultaneously, while in others they occur in rapid succession. In this study, we investigated the effects of elevated pCO2 on oxygen consumption by larvae of the intertidal porcelain crab Petrolisthes cinctipes when exposed to subsequent salinity stress. Such an exposure mimics how larvae under future acidified conditions will likely experience sudden runoff events such as those that occur seasonally along portions of the west coast of the U.S. and in other temperate systems, or how larvae encounter hypersaline waters when crossing density gradients via directed swimming. We raised larvae in the laboratory under ambient and predicted future pCO2 levels (385 and 1000 µatm) for 10 days, and then moved them to seawater at ambient pCO2 but with decreased, ambient, or elevated salinity, to monitor their respiration. While larvae raised under elevated pCO2 or exposed to stressful salinity conditions alone did not exhibit higher respiration rates than larvae held in ambient conditions, larvae exposed to elevated pCO2 followed by stressful salinity conditions consumed more oxygen. These results show that even when multiple stressors act sequentially rather than simultaneously, they can retain their capacity to detrimentally affect organisms. PMID:25295878
Snedden, Gregg A.; Cretini, Kari Foster; Patton, Brett
2015-01-01
Inundation and salinity directly affect plant productivity and processes that regulate vertical accretion in coastal wetlands, and are expected to increase as sea level continues to rise. In the Mississippi River deltaic plain, river diversions, which are being implemented as ecosystem restoration tools, can also strongly increase inundation in coastal wetlands. We used an in situ mesocosm approach to examine how varying salinity (two levels) and inundation rates (six levels) influenced end-of-season above- and belowground biomass of Spartina patens and Spartina alterniflora during the growing season (March–October) in 2011. Above- and belowground biomass was highest in both species at higher elevations when inundation was minimal, and decreased exponentially with decreased elevation and increased flood duration. This negative biomass response to flooding was more pronounced in S. patens than in S. alterniflora, and S. patens also showed stronger biomass reductions at higher salinities. This salinity effect was absent for belowground biomass in S. alterniflora. These findings suggest that even subtle increases in sea level may lead to substantial reductions in productivity and organic accretion, and also illustrate the importance of considering the inundation tolerance of co-dominant species in receiving areas when utilizing river diversions for delta restoration.
Parker, Laura M; Scanes, Elliot; O'Connor, Wayne A; Coleman, Ross A; Byrne, Maria; Pörtner, Hans-O; Ross, Pauline M
2017-09-15
Coastal and estuarine environments are characterised by acute changes in temperature and salinity. Organisms living within these environments are adapted to withstand such changes, yet near-future ocean acidification (OA) may challenge their physiological capacity to respond. We tested the impact of CO 2 -induced OA on the acute thermal and salinity tolerance, energy metabolism and acid-base regulation capacity of the oyster Saccostrea glomerata. Adult S. glomerata were acclimated to three CO 2 levels (ambient 380μatm, moderate 856μatm, high 1500μatm) for 5weeks (24°C, salinity 34.6) before being exposed to a series of acute temperature (15-33°C) and salinity (34.2-20) treatments. Oysters acclimated to elevated CO 2 showed a significant metabolic depression and extracellular acidosis with acute exposure to elevated temperature and reduced salinity, especially at the highest CO 2 of 1500μatm. Our results suggest that the acute thermal and salinity tolerance of S. glomerata and thus its distribution will reduce as OA continues to worsen. Copyright © 2017 Elsevier Ltd. All rights reserved.
Climate change is likely to alter the spatial distribution of abiotic gradients in estuaries, potentially increasing stress in tidal wetland plants. Using field and lab manipulations, we examined inter-specific variation in responses to elevated salinity and inundation in the Ore...
Nawrocki, Michael A; McLaughlin, Ron; Hendrix, P K
2005-01-01
To document the magnitude of temperature elevation obtained with heated lavage solutions during abdominal lavage, 18 dogs were lavaged with sterile isotonic saline intraoperatively (i.e., during a celiotomy). In nine dogs, room-temperature saline was used. In the remaining nine dogs, saline heated to 43+/-2 degrees C (110+/-4 degrees F) was used. Esophageal, rectal, and tympanic temperatures were recorded every 60 seconds for 15 minutes after initiation of the lavage. Temperature levels decreased in dogs lavaged with room-temperature saline. Temperature levels increased significantly in dogs lavaged with heated saline after 2 to 6 minutes of lavage, and temperatures continued to increase throughout the 15-minute lavage period.
Blair, Salvatore D.; Matheson, Derrick
2017-01-01
Abstract Freshwater environments are at risk of increasing salinity due to multiple anthropogenic forces including current oil and gas extraction practices that result in large volumes of hypersaline water. Unintentional releases of hypersaline water into freshwater environments act as an osmoregulatory stressor to many aquatic organisms including native salmonids like the Arctic grayling (Thymallus arcticus). Compared to more euryhaline salmonids, Arctic grayling have a reduced salinity tolerance and develop an elevated interlamellar cell mass (ILCM) in response to salinity exposure (17 ppt). In this study, we described the gill morphology and cell types characterizing the ICLM. Further, we investigated whether Arctic grayling could recover in freshwater following a short-term (<48 h) salinity exposure. Arctic grayling were exposed to 17 ppt saline water for 12, 24 and 48 h. Following the 24 and 48 h salinity exposure, Arctic grayling were returned to freshwater for 24 h to assess their ability to recover from, and reverse, the osmotic disturbances. Physiological serum [Na+], [Cl–] and total osmolality were significantly elevated and progressively increased at 12, 24 and 48 h salinity exposures. The 24 h post-exposure recovery period resulted in Arctic grayling serum ion concentrations and total osmolality returning to near normal levels. Similar recovery patterns were observed in the salinity-induced ILCM, which developed as early as 12 h of exposure to 17 ppt, and then reverted to control levels following 24 h in freshwater. Gill histology indicates an increased number of apically located mucous cells in the interlamellar space following salinity exposure of Arctic grayling. The scanning electron microscopy and transmission electron microscopy data show the presence of granule containing eosinophil-like cells infiltrating the ILCM suggesting a salinity-induced immune response by the Arctic grayling. PMID:28680637
Goodman, Joie; Maschinski, Joyce; Hughes, Phillip; McAuliffe, Joe; Roncal, Julissa; Powell, Devon; Sternberg, Leonel O'reilly
2012-01-01
Understanding reasons for biodiversity loss is essential for developing conservation and management strategies and is becoming increasingly urgent with climate change. Growing at elevations <1.4 m in the Florida Keys, USA, the endangered Key tree cactus (Pilosocereus robinii) experienced 84 percent loss of total stems from 1994 to 2007. The most severe losses of 99 and 88 percent stems occurred in the largest populations in the Lower Keys, where nine storms with high wind velocities and storm surges, occurred during this period. In contrast, three populations had substantial stem proliferation. To evaluate possible mortality factors related to changes in climate or forest structure, we examined habitat variables: soil salinity, elevation, canopy cover, and habitat structure near 16 dying or dead and 18 living plants growing in the Lower Keys. Soil salinity and elevation were the preliminary factors that discriminated live and dead plants. Soil salinity was 1.5 times greater, but elevation was 12 cm higher near dead plants than near live plants. However, distribution-wide stem loss was not significantly related to salinity or elevation. Controlled salinity trials indicated that salt tolerance to levels above 40 mM NaCl was related to maternal origin. Salt sensitive plants from the Lower Keys had less stem growth, lower root:shoot ratios, lower potassium: sodium ratios and lower recovery rate, but higher δ 13C than a salt tolerant lineage of unknown origin. Unraveling the genetic structure of salt tolerant and salt sensitive lineages in the Florida Keys will require further genetic tests. Worldwide rare species restricted to fragmented, low-elevation island habitats, with little or no connection to higher ground will face challenges from climate change-related factors. These great conservation challenges will require traditional conservation actions and possibly managed relocation that must be informed by studies such as these. PMID:22403670
Goodman, Joie; Maschinski, Joyce; Hughes, Phillip; McAuliffe, Joe; Roncal, Julissa; Powell, Devon; Sternberg, Leonel O'reilly
2012-01-01
Understanding reasons for biodiversity loss is essential for developing conservation and management strategies and is becoming increasingly urgent with climate change. Growing at elevations <1.4 m in the Florida Keys, USA, the endangered Key tree cactus (Pilosocereus robinii) experienced 84 percent loss of total stems from 1994 to 2007. The most severe losses of 99 and 88 percent stems occurred in the largest populations in the Lower Keys, where nine storms with high wind velocities and storm surges, occurred during this period. In contrast, three populations had substantial stem proliferation. To evaluate possible mortality factors related to changes in climate or forest structure, we examined habitat variables: soil salinity, elevation, canopy cover, and habitat structure near 16 dying or dead and 18 living plants growing in the Lower Keys. Soil salinity and elevation were the preliminary factors that discriminated live and dead plants. Soil salinity was 1.5 times greater, but elevation was 12 cm higher near dead plants than near live plants. However, distribution-wide stem loss was not significantly related to salinity or elevation. Controlled salinity trials indicated that salt tolerance to levels above 40 mM NaCl was related to maternal origin. Salt sensitive plants from the Lower Keys had less stem growth, lower root:shoot ratios, lower potassium: sodium ratios and lower recovery rate, but higher δ (13)C than a salt tolerant lineage of unknown origin. Unraveling the genetic structure of salt tolerant and salt sensitive lineages in the Florida Keys will require further genetic tests. Worldwide rare species restricted to fragmented, low-elevation island habitats, with little or no connection to higher ground will face challenges from climate change-related factors. These great conservation challenges will require traditional conservation actions and possibly managed relocation that must be informed by studies such as these.
Atlantic Intracoastal Waterway (AIWW) Maintenance Program Evaluation Study.
1983-01-01
offset by rising sea levels. Few plant species can withstand the stress imposed by high salinity and daily inundation by tidal waters, and marsh...related to gradients in salinity and elevation. 7 K-e--.2 The wetlands through which the Atlantic intracoastal Water-day passes are fEeding and nursery...with wetland plant species dominated by salt marsh cotdgra-,s (Spartina alterniflora) in saline areas and giant cordgrass (Spar ti:: cynosurrides) in
Stephens, D.W.
1990-01-01
Great Salt Lake is the fourth largest terminal lake in the world, with an area of about 6000 square kilometers at its historic high elevation. Since its historic low elevation of 1277.52 meters in 1963, the lake has risen to a new historic high elevation of 1283.77 meters in 1986-1987, a net increase of about 6.25 meters. About 60 percent of this increase, 3.72 meters, has occurred since 1982 in response to greater than average precipitation and less than average evaporation. Variations in salinity have resulted in changes in the composition of the aquatic biological community which consists of bacteria, protozoa, brine shrimp and brine flies. These changes were particularly evident following the completion of a causeway in 1959 which divided the lake. Subsequent salinities in the north part of the lake have ranged from 16 to 29 percent and in the south part from 6 to 28 percent. Accompanying the rise in lake elevation from 1982 to 1987 have been large decreases in salinity of both parts of the lake. This has resulted in changes in the biota from obligate halophiles, such as Dunaliella salina and D. viridis, to opportunistic forms such as a blue-green alga (Nodularia spumigena). The distribution and abundance of brine shrimp (Artemia salina) in the lake also have followed closely the salinity. In 1986, when the salinity of the south part of the lake was about 6 percent, a population of brackish-water killifish (Lucania parva) was observed along the shore near inflow from a spring. ?? 1990 Kluwer Academic Publishers.
Trevathan, Stacey M; Kahn, Amanda; Ross, Cliff
2011-09-01
Seagrass meadows are a vital component of coastal ecosystems and have experienced declines in abundance due to a series of environmental stressors including elevated salinity and incidence of disease. This study evaluated the impacts of short-term hypersalinity stress on the early stages of infection in Thalassia testudinum Banks ex König by assessing changes in cellular physiology and metabolism. Seagrass short shoots were exposed to ambient (30 psu) and elevated (45 psu) salinities for 7 days and subsequently infected for one week by the causative pathogen of wasting disease, Labyrinthula sp. The occurrence of wasting disease was significantly lower in the hypersalinity treatments. Additionally, while exposure to elevated salinity caused a reduction in chlorophyll a and b content, T. testudinum's health, in terms of photochemical efficiency, was not significantly compromised by hypersalinity or infection. In contrast, plant respiratory demand was significantly enhanced as a function of infection. Elevated salinity caused T. testudinum to significantly increase its in vivo H(2)O(2) concentrations to levels that exceeded those which inhibited Labyrinthula growth in a liquid in vitro assay. The results suggest that while short-term exposure to hypersalinity alters selected cellular processes this does not necessarily lead to an immediate increase in wasting disease susceptibility. Published by Elsevier Masson SAS.
Piñero, María Carmen; Houdusse, Fabrice; Garcia-Mina, Jose M; Garnica, María; Del Amor, Francisco M
2014-08-01
This study examines the extent to which the predicted CO2 -protective effects on the inhibition of growth, impairment of photosynthesis and nutrient imbalance caused by saline stress are mediated by an effective adaptation of the endogenous plant hormonal balance. Therefore, sweet pepper plants (Capsicum annuum, cv. Ciclón) were grown at ambient or elevated [CO2] (400 or 800 µmol mol(-1)) with a nutrient solution containing 0 or 80 mM NaCl. The results show that, under saline conditions, elevated [CO2] increased plant dry weight, leaf area, leaf relative water content and net photosynthesis compared with ambient [CO2], whilst the maximum potential quantum efficiency of photosystem II was not modified. In salt-stressed plants, elevated [CO2 ] increased leaf NO3(-) concentration and reduced Cl(-) concentration. Salinity stress induced ABA accumulation in the leaves but it was reduced in the roots at high [CO2], being correlated with the stomatal response. Under non-stressed conditions, IAA was dramatically reduced in the roots when high [CO2] was applied, which resulted in greater root DW and root respiration. Additionally, the observed high CK concentration in the roots (especially tZR) could prevent downregulation of photosynthesis at high [CO2], as the N level in the leaves was increased compared with the ambient [CO2], under salt-stress conditions. These results demonstrate that the hormonal balance was altered by the [CO2], which resulted in significant changes at the growth, gas exchange and nutritional levels. © 2013 Scandinavian Plant Physiology Society.
NASA Astrophysics Data System (ADS)
Schile, L. M.; Callaway, J. C.; Kelly, M.
2011-12-01
Sea-level is expected to rise between 55 and 140 cm in the next century and is likely to have significant effects on the distribution and maintenance of tidal wetlands; however, little is known about the effects of increased sea level on Pacific coast tidal marsh vegetation. We initiated a field experiment in March 2011 to examine how increased depth and duration of inundation affect above and below-ground growth of two tidal wetland plant species: Schoenoplectus acutus and S. americanus. PVC planters, referred to as marsh organs, were installed at fixed elevations in channels at two ancient marshes in the San Francisco Bay Estuary: Browns Island and Rush Ranch. Each marsh organ structure is comprised of five rows of three six-inch PVC pipes, with each row 15cm lower than the row above, and was filled with surrounding mudflat sediment. Elevations span 60 cm and were chosen to be lower than the average current elevations of both species at each marsh to reflect projected increases in sea level. Rhizomes were collected from Browns Island, the less-saline site, and were cut to uniform sizes before planting. In every row, each species was grown individually and together. On a monthly basis, plant heights were recorded and pore-water sulfide concentration, salinity, and soil oxidation-reduction potential were measured. Schoenoplectus americanus growth and density significantly decreased with increased inundation at both sites. Schoenoplectus acutus growth was impacted more significantly at lower elevations at Rush Ranch but had little variation in density and growth across elevations at Browns Island. Salinity and sulfide concentrations varied little across elevations within a site but differed between sites. Above and belowground biomass will be collected in September 2011 to measure total annual productivity. The experiment provides basic yet crucial information on the impacts of increased inundation on tidal wetland vegetation and insight into potential changes in plant assemblages with predicted climate change.
NASA Astrophysics Data System (ADS)
Linard, J.; Leib, K.; Colorado Water Science Center
2010-12-01
Elevated levels of salinity and dissolved selenium can detrimentally effect the quality of water where anthropogenic and natural uses are concerned. In areas, such as the lower Gunnison Basin of western Colorado, salinity and selenium are such a concern that control projects are implemented to limit their mobilization. To prioritize the locations in which control projects are implemented, multi-parameter regression models were developed to identify subbasins in the lower Gunnison River Basin that were most likely to have elevated salinity and dissolved selenium levels. The drainage area is about 5,900 mi2 and is underlain by Cretaceous marine shale, which is the most common source of salinity and dissolved selenium. To characterize the complex hydrologic and chemical processes governing constituent mobilization, geospatial variables representing 70 different environmental characteristics were correlated to mean seasonal (irrigation and nonirrigation seasons) salinity and selenium yields estimated at 154 sampling sites. The variables generally represented characteristics of the physical basin, precipitation, soil, geology, land use, and irrigation water delivery systems. Irrigation and nonirrigation seasons were selected due to documented effects of irrigation on constituent mobilization. Following a stepwise approach, combinations of the geospatial variables were used to develop four multi-parameter regression models. These models predicted salinity and selenium yield, within a 95 percent confidence range, at individual points in the Lower Gunnison Basin for irrigation and non-irrigation seasons. The corresponding subbasins were ranked according to their potential to yield salinity and selenium and rankings were used to prioritize areas that would most benefit from control projects.
Faulkner, P C; Burleson, M L; Simonitis, L; Marshall, C; Hala, D; Petersen, L H
2018-05-18
American alligator ( Alligator mississippiensis , Linnaeus) habitats are prone to saltwater intrusion following major storms, hurricanes or droughts. Anthropogenic impacts affecting hydrology of freshwater systems may exacerbate saltwater intrusion into freshwater habitats. The endocrine system of alligators is susceptible to changes in the environment but it is currently not known how the crocodilian physiological system responds to environmental stressors such as salinity. Juvenile alligators were exposed to 12‰ saltwater for 5 weeks to determine effects of chronic exposure to saline environments. Following 5 weeks, plasma levels of hormones (e.g., progesterone, testosterone, estradiol, corticosterone, aldosterone, angiotensin II) were quantified using LC-MS/MS. Compared to freshwater kept subjects, saltwater exposed alligators had significantly elevated plasma levels of corticosterone, 11-deoxycortisol, 17α-hydroxyprogesterone, testosterone, 17β-estradiol, estrone and estriol while pregnenolone and angiotensin II (ANG II) were significantly depressed and aldosterone (ALDO) levels were unchanged (slightly depressed). However, saltwater exposure did not affect gene expression of renal mineralo- and glucorticoid (MR, GR) and angiotensin type 1 (AT-1) receptors or morphology of lingual glands. On the other hand, saltwater exposure significantly reduced plasma glucose concentrations whereas parameters diagnostic of perturbed liver function (enzymes AST, ALT) and kidney function (creatinine, creatine kinase) were significantly elevated. Except for plasma potassium levels (K + ), plasma ions Na + and Cl - were significantly elevated in saltwater alligators. Overall, this study demonstrated significant endocrine and physiological effects in juvenile alligators chronically exposed to a saline environment. Results provide novel insights into the effects of a natural environmental stressor (salinity) on renin-angiotensin-aldosterone system and steroidogenesis of alligators. © 2018. Published by The Company of Biologists Ltd.
Estuarine organisms are adapted to frequent changes in temperature, salinity, pH, and dissolved oxygen (DO) levels. The high productivity of an estuary contributes to large changes in environmental conditions, with organismal respiration enhancing hypoxic zones, and elevating pCO...
Varying Inundation Regimes Differentially Affect Natural and Sand-Amended Marsh Sediments.
Wigand, C; Sundberg, K; Hanson, A; Davey, E; Johnson, R; Watson, E; Morris, J
2016-01-01
Climate change is altering sea level rise rates and precipitation patterns worldwide. Coastal wetlands are vulnerable to these changes. System responses to stressors are important for resource managers and environmental stewards to understand in order to best manage them. Thin layer sand or sediment application to drowning and eroding marshes is one approach to build elevation and resilience. The above- and below-ground structure, soil carbon dioxide emissions, and pore water constituents in vegetated natural marsh sediments and sand-amended sediments were examined at varying inundation regimes between mean sea level and mean high water (0.82 m NAVD88 to 1.49 m NAVD88) in a field experiment at Laws Point, part of the Plum Island Sound Estuary (MA). Significantly lower salinities, pH, sulfides, phosphates, and ammonium were measured in the sand-amended sediments than in the natural sediments. In natural sediments there was a pattern of increasing salinity with increasing elevation while in the sand-amended sediments the trend was reversed, showing decreasing salinity with increasing elevation. Sulfide concentrations generally increased from low to high inundation with highest concentrations at the highest inundation (i.e., at the lowest elevations). High pore water phosphate concentrations were measured at low elevations in the natural sediments, but the sand-amended treatments had mostly low concentrations of phosphate and no consistent pattern with elevation. At the end of the experiment the lowest elevations generally had the highest measures of pore water ammonium. Soil carbon dioxide emissions were greatest in the sand-amended mesocosms and at higher elevations. Differences in coarse root and rhizome abundances and volumes among the sediment treatments were detected with CT imaging, but by 20 weeks the natural and sand-amended treatments showed similar total belowground biomass at the intermediate and high elevations. Although differences in pore water nutrient concentrations, pH, salinity, and belowground root and rhizome morphology were detected between the natural and sand-amended sediments, similar belowground productivity and total biomass were measured by the end of the growing season. Since the belowground productivity supports organic matter accumulation and peat buildup in marshes, our results suggest that thin layer sand or sediment application is a viable climate adaptation action to build elevation and coastal resiliency, especially in areas with low natural sediment supplies.
The physiology of mangrove trees with changing climate
Lovelock, Catherine E.; Krauss, Ken W.; Osland, Michael J.; Reef, Ruth; Ball, Marilyn C.; Meinzer, Frederick C.; Niinemets, Ülo
2016-01-01
Mangrove forests grow on saline, periodically flooded soils of the tropical and subtropical coasts. The tree species that comprise the mangrove are halophytes that have suites of traits that confer differing levels of tolerance of salinity, aridity, inundation and extremes of temperature. Here we review how climate change and elevated levels of atmospheric CO2 will influence mangrove forests. Tolerance of salinity and inundation in mangroves is associated with the efficient use of water for photosynthetic carbon gain which unpins anticipated gains in productivity with increasing levels of CO2. We review evidence of increases in productivity with increasing CO2, finding that enhancements in growth appear to be similar to trees in non-mangrove habitats and that gains in productivity with elevated CO2 are likely due to changes in biomass allocation. High levels of trait plasticity are observed in some mangrove species, which potentially facilitates their responses to climate change. Trait plasticity is associated with broad tolerance of salinity, aridity, low temperatures and nutrient availability. Because low temperatures and aridity place strong limits on mangrove growth at the edge of their current distribution, increasing temperatures over time and changing rainfall patterns are likely to have an important influence on the distribution of mangroves. We provide a global analysis based on plant traits and IPCC scenarios of changing temperature and aridity that indicates substantial global potential for mangrove expansion.
Cabbia, Rafael; Consoli, Amanda; Suchecki, Deborah
2018-04-01
Maternal deprivation (MD) disinhibits the adrenal glands, rendering them responsive to various stressors, including saline injection, and this increased corticosterone (CORT) response can last for as long as 2 h. In the present study, we tested the hypothesis that association of MD on day 11 with a saline injection would alter emotional behavior, CORT response, and brain monoamine levels, in male and female adult rats. Rats were submitted to the novelty suppressed feeding (NSF), the sucrose negative contrast test (SNCT), social investigation test (SIT), and the elevated plus maze (EPM). One quarter of each group was not tested (providing basal values of CORT and brain monoamines) and the remainder was decapitated 15, 45, or 75 min after the EPM, to assess CORT reactivity. Monoamine levels were determined in the hypothalamus (HPT), frontal cortex (FC), amygdala (AMY), ventral, and dorsal hippocampus (vHPC, dHPC, respectively). MD reduced food intake, in the home-cage, and latency to eat in the NSF in both sexes; females explored less the target animal in the SIT and explored more the open arms of the EPM than males; the CORT response to the EPM was greater in maternally-deprived males and females than in their control counterparts, and this response was further elevated in maternally-deprived females injected with saline. Regarding monoamine levels, females were less affected, showing isolated effects of the stressors, while in males, MD increased 5-HT levels in the HPT and decreased this monoamine in the FC, MD associated with saline reduced dopamine levels in all brain regions, except the HPT. MD at 11 days did not alter emotional behaviors in adult rats, but had an impact in neurobiological parameters associated with this class of behaviors. The impact of MD associated with saline on dopamine levels suggests that males may be vulnerable to motivation-related disorders.
Zhu, Huaping; Liu, Zhigang; Gao, Fengying; Lu, Maixin; Liu, Yujiao; Su, Huanhuan; Ma, Dongmei; Ke, Xiaoli; Wang, Miao; Cao, Jianmeng; Yi, Mengmeng
2018-05-28
Tilapia (Oreochromis mossambicus, O. urolepis hornorum, their hybrids O. mossambicus♀ × O. hornorum♂ and O. hornorum♀ × O. mossambicus♂) were exposed to a high salinity environment to evaluate their osmoregulatory responses. The plasma osmolality of all the tilapia species were elevated with the salinity challenge. The activities of Na + /K + -ATPase (NKA) in both the gill and kidney showed a similar increased change tendency compared with the control. The distribution of NKA α1 mRNA in all the examined tissues suggested that NKA α1 has a possible housekeeping role for this isoform. The amount of NKA α1 mRNA in the gill and kidney was elevated in the four fishes with similar expression patterns after transfer from freshwater to seawater. The NKAα1 mRNA expression levels in the gill reached their peak level at 24 h after transfer (P < 0.01) compared to the freshwater group, following decreases in the pretreatment level at 48 h (P > 0.05). However, the NKAα1 mRNA expression levels in the kidney were not significantly affected with increasing environmental salinity (P > 0.05). The differences in the responses to saltwater challenge may be associated with differences in saltwater tolerance between the four tilapia. The drastic increase in the plasma osmolality, NKA activities and mRNA expression suggested that the hybrids (O. mossambicus♀ × O. hornorum♂) possess heterosis in salinity responsiveness compared to that of both the parents, indicating a maternal effect on the salinity tolerance of the tilapia hybrids. This study provides a theoretical basis to further study the mechanism of fish osmoregulation response to salinity challenge. Copyright © 2018 Elsevier Inc. All rights reserved.
George, Elizabeth M; Rosvall, Kimberly A
2018-06-02
In many vertebrates, males increase circulating testosterone (T) levels in response to seasonal and social changes in competition. Females are also capable of producing and responding to T, but the full extent to which they can elevate T across life history stages remains unclear. Here we investigated T production during various breeding stages in female tree swallows (Tachycineta bicolor), which face intense competition for nesting sites. We performed GnRH and saline injections and compared changes in T levels 30 min before and after injection. We found that GnRH-injected females showed the greatest increases in T during territory establishment and pre-laying stages, whereas saline controls dramatically decreased T production during this time. We also observed elevated rates of conspecific aggression during these early stages of breeding. During incubation and provisioning, however, T levels and T production capabilities declined. Given that high T can disrupt maternal care, an inability to elevate T levels in later breeding stages may be adaptive. Our results highlight the importance of saline controls for contextualizing T production capabilities, and they also suggest that social modulation of T is a potential mechanism by which females may respond to competition, but only during the period of time when competition is most intense. These findings have broad implications for understanding how females can respond to their social environment and how selection may have shaped these hormone-behavior interactions. Copyright © 2018 Elsevier Inc. All rights reserved.
Physiological Responses to Salinity Vary with Proximity to the Ocean in a Coastal Amphibian.
Hopkins, Gareth R; Brodie, Edmund D; Neuman-Lee, Lorin A; Mohammadi, Shabnam; Brusch, George A; Hopkins, Zoë M; French, Susannah S
2016-01-01
Freshwater organisms are increasingly exposed to elevated salinity in their habitats, presenting physiological challenges to homeostasis. Amphibians are particularly vulnerable to osmotic stress and yet are often subject to high salinity in a variety of inland and coastal environments around the world. Here, we examine the physiological responses to elevated salinity of rough-skinned newts (Taricha granulosa) inhabiting a coastal stream on the Pacific coast of North America and compare the physiological responses to salinity stress of newts living in close proximity to the ocean with those of newts living farther upstream. Although elevated salinity significantly affected the osmotic (body weight, plasma osmolality), stress (corticosterone), and immune (bactericidal ability) responses of newts, animals found closer to the ocean were generally less reactive to salt stress than those found farther upstream. Our results provide possible evidence for some physiological tolerance in this species to elevated salinity in coastal environments. As freshwater environments become increasingly saline and more stressful, understanding the physiological tolerances of vulnerable groups such as amphibians will become increasingly important to our understanding of their abilities to respond, to adapt, and, ultimately, to survive.
Allen, J.A.; Chambers, J.L.; Pezeshki, S.R.
1997-01-01
Growth and physiological responses of 15 open-pollinated families of baldcypress (Taxodium distichum var. distichum) subjected to flooding with saline water were evaluated in this study. Ten of the families were from coastal sites in Louisiana and Alabama, USA that have elevated levels of soil-water salinity. The other five families were from inland, freshwater sites in Louisiana. Seedlings from all families tolerated flooding with water of low (2 g l-1) salinity. Differences in biomass among families became most apparent at the highest salinity levels (6 and 8 g l-1). Overall, increasing salinity reduced leaf biomass more than root biomass, which in turn was reduced more than stem biomass. A subset of seedlings from the main greenhouse experiment was periodically placed indoors under artificial light, and measurements were made of gas exchange and leaf water potential. Also, tissue concentrations of Cl-, Na+, K+, and Ca2+ were determined at the end of the greenhouse experiment. Significant intraspecific variation was found for nearly all the physiological parameters evaluated, but only leaf concentrations of Na+ and Cl- were correlated with an index of family-level differences in salt tolerance.
Influence of increasing temperature and salinity on herbicide toxicity in estuarine phytoplankton.
DeLorenzo, Marie E; Danese, Loren E; Baird, Thomas D
2013-07-01
Ecological risk assessments are, in part, based on results of toxicity tests conducted under standard exposure conditions. Global climate change will have a wide range of effects on estuarine habitats, including potentially increasing water temperature and salinity, which may alter the risk assessment of estuarine pollutants. We examined the effects of increasing temperature and salinity on the toxicity of common herbicides (irgarol, diuron, atrazine, and ametryn) to the phytoplankton species Dunaliella tertiolecta. Static 96-h algal bioassays were conducted for each herbicide under four exposure scenarios: standard temperature and salinity (25°C, 20 ppt), standard temperature and elevated salinity (25°C, 40 ppt), elevated temperature and standard salinity (35°C, 20 ppt), and elevated temperature and elevated salinity (35°C, 40 ppt). The endpoints assessed were algal cell density at 96 h, growth rate, chlorophyll a content, lipid content, and starch content. Increasing exposure temperature reduced growth rate and 96-h cell density but increased the cellular chlorophyll and lipid concentrations of the control algae. Exposure condition did not alter starch content of control algae. Herbicides were found to decrease growth rate, 96 h cell density, and cellular chlorophyll and lipid concentrations, while starch concentrations increased with herbicide exposure. Herbicide effects under standard test conditions were then compared with those observed under elevated temperature and salinity. Herbicide effects on growth rate, cell density, and starch content were more pronounced under elevated salinity and temperature conditions. To encompass the natural variability in estuarine temperature and salinity, and to account for future changes in climate, toxicity tests should be conducted under a wider range of environmental conditions. Copyright © 2011 Wiley Periodicals, Inc.
NASA Astrophysics Data System (ADS)
Chui, Apple Pui Yi; Ang, Put
2015-06-01
To better understand the possible consequences of climate change on reef building scleractinian corals in a marginal environment, laboratory experiments were conducted to examine the interactive effects of changes in salinity and temperature on percent fertilization success and early embryonic development of the coral Platygyra acuta. In the present study, a salinity of 24 psu (ambient 32 psu) reduced fertilization success by 60 %. Normal embryonic development was reduced by >80 % at 26 psu (ambient 33 psu) with 100 % abnormal development at 22 psu under ambient temperature. Elevated temperature (+3 °C) above the ambient spawning temperature did not show any negative effects on fertilization success. However, there was a trend for more abnormal embryos to develop at elevated temperature in the 2 d of the spawning event. The interactive effects between salinity and temperature are statistically significant only on normal embryonic development of P. acuta, but not on its fertilization success. Salinity was revealed to be the main factor affecting both fertilization success and normal embryonic development. Interestingly, the much lower fertilization success (76 %) observed in the second day of spawning (Trial 2) under ambient temperature recovered to 99 % success under elevated (+3 °C) temperature conditions. Moreover, elevated temperature enhanced normal early embryonic development under lowered salinity (26 psu). This antagonistic interactive effect was consistently observed in two successive nights of spawning. Overall, our results indicate that, in terms of its fertilization success and embryonic development, P. acuta is the most tolerant coral species to reduced salinity thus far reported in the literature. Elevated temperature, at least that within the tolerable range of the corals, could apparently alleviate the potential negative effects from salinity stresses. This mitigating role of elevated temperature appears not to have been reported on corals before.
Rodríguez-Hernández, María del Carmen; Moreno, Diego A; Carvajal, Micaela; Martínez-Ballesta, María del Carmen
2014-12-01
Climatic change predicts elevated salinity in soils as well as increased carbon dioxide dioxide [CO2] in the atmosphere. The present study aims to determine the effect of combined salinity and elevated [CO2] on sulfur (S) metabolism and S-derived phytochemicals in green and purple broccoli (cv. Naxos and cv. Viola, respectively). Elevated [CO2] involved the amelioration of salt stress, especially in cv. Viola, where a lower biomass reduction by salinity was accompanied by higher sodium (Na(+)) and chloride (Cl(-)) compartmentation in the vacuole. Moreover, salinity and elevated [CO2] affected the mineral and glucosinolate contents and the activity of biosynthetic enzymes of S-derived compounds and the degradative enzyme of glucosinolate metabolism, myrosinase, as well as the related amino acids and the antioxidant glutathione (GSH). In cv. Naxos, elevated [CO2] may trigger the antioxidant response to saline stress by means of increased GSH concentration. Also, in cv. Naxos, indolic glucosinolates were more influenced by the NaCl×CO2 interaction whereas in cv. Viola the aliphatic glucosinolates were significantly increased by these conditions. Salinity and elevated [CO2] enhanced the S cellular partitioning and metabolism affecting the myrosinase-glucosinolate system. © The Author 2014. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.
NASA Astrophysics Data System (ADS)
McKee, M.; White, J. R.; Putnam-Duhon, L. A.
2016-11-01
Coastal wetland systems experience both short-term changes in salinity, such as those caused by wind-driven tides and storm surge, and long-term shifts caused by sea level rise. Salinity increases associated with storm surge are known to have significant effects on soil porewater chemistry, but there is little research on the effect of flooding length on salt penetration depth into coastal marsh soils. A simulated storm surge was imposed on intact soil columns collected from a non-vegetated mudflat and a vegetated marsh site in the Wax Lake Delta, LA. Triplicate intact cores were continuously exposed to a 35 salinity water column (practical salinity scale) for 1, 2, and 4 weeks and destructively sampled in order to measure porewater salinity and extractable NH4sbnd N at two cm depth intervals. Salinity was significantly higher in the top 8 cm for both the marsh and mudflat cores after one week of flooding. After four weeks of flooding, salinity was significantly higher in marsh and mudflat cores compared to the control (no salinity) cores throughout the profile for both sites. Extractable ammonium levels increased significantly in the marsh cores throughout the experiment, but there was only a marginally (p < 0.1) significant increase seen in the mudflat cores. Results indicate that porewater salinity levels can become significantly elevated within a coastal marsh soil in just one week. This vertical intrusion of salt can potentially negatively impact macrophytes and associated microbial communities for significantly longer term post-storm surge.
Fresh-water discharge salinity relations in the tidal Delaware River
Keighton, Walter B.
1966-01-01
Sustained flows of fresh water greater than 3,500, 4,400, and 5,300 cubic feet per second into the Delaware River estuary at Trenton, NJ assure low salinity at League Island, Eddystone, and Marcus Hook, respectively. When the discharge at Trenton is less than these critical values, salinity is very sensitive to change in discharge, so that a relatively small decrease in fresh-water discharge results in a relatively great increase in salinity. Comparison of the discharge-salinity relations observed for the 14-year period August 1949-December 1963 with relations proposed by other workers but based on other time periods indicate that such relations change with time and that salinity is affected not only by discharge but also by dredging; construction of breakwater, dikes, and tidal barriers; changing sea level; tidal elevation; tidal range; and wind intensity and direction.
Reef, Ruth; Winter, Klaus; Morales, Jorge; Adame, Maria Fernanda; Reef, Dana L; Lovelock, Catherine E
2015-07-01
By increasing water use efficiency and carbon assimilation, increasing atmospheric CO2 concentrations could potentially improve plant productivity and growth at high salinities. To assess the effect of elevated CO2 on the salinity response of a woody halophyte, we grew seedlings of the mangrove Avicennia germinans under a combination of five salinity treatments [from 5 to 65 parts per thousand (ppt)] and three CO2 concentrations (280, 400 and 800 ppm). We measured survivorship, growth rate, photosynthetic gas exchange, root architecture and foliar nutrient and ion concentrations. The salinity optima for growth shifted higher with increasing concentrations of CO2 , from 0 ppt at 280 ppm to 35 ppt at 800 ppm. At optimal salinity conditions, carbon assimilation rates were significantly higher under elevated CO2 concentrations. However, at salinities above the salinity optima, salinity had an expected negative effect on mangrove growth and carbon assimilation, which was not alleviated by elevated CO2 , despite a significant improvement in photosynthetic water use efficiency. This is likely due to non-stomatal limitations to growth at high salinities, as indicated by our measurements of foliar ion concentrations that show a displacement of K(+) by Na(+) at elevated salinities that is not affected by CO2 . The observed shift in the optimal salinity for growth with increasing CO2 concentrations changes the fundamental niche of this species and could have significant effects on future mangrove distribution patterns and interspecific interactions. © 2014 Scandinavian Plant Physiology Society.
Choi, Young Jae; Kim, Na Na; Shin, Hyun Suk; Choi, Cheol Young
2014-01-01
Leptin plays an important role in energy homeostasis and reproductive function in fish, especially in reproduction. Migrating fish, such as salmonoids, are affected by external environmental factors, and salinity changes are a particularly important influence on spawning migrations. The aim of this study was to test whether changes in salinity affect the expression of leptin, estrogen receptors (ERs), and vitellogenin (VTG) in chum salmon (Oncorhynchus keta). The expression and activity of leptin, the expression of ERs and VTG, and the levels of estradiol-17β and cortisol increased after the fish were transferred to FW, demonstrating that changes in salinity stimulate the HPG axis in migrating female chum salmon. These findings reveal details about the role of elevated leptin levels and sex steroid hormones in stimulating sexual maturation and reproduction in response to salinity changes in chum salmon. PMID:25049977
In vivo comparison of biomimetic approaches for tissue regeneration of the scarred vocal fold.
Thibeault, Susan L; Klemuk, Sarah A; Smith, Marshall E; Leugers, Cecilia; Prestwich, Glenn
2009-07-01
The objective of this study was to determine if three different biomimetic approaches could facilitate tissue regeneration and improve viscoelastic properties in the scarred vocal fold lamina propria extracellular matrix (ECM). Twenty rabbit vocal folds were biopsied bilaterally; 2 months postinjury rabbits were unilaterally treated with (i) autologous fibroblasts, (ii) a semisynthetic ECM (sECM), or (iii) autologous fibroblasts encapsulated in sECM. Saline was injected as a control into the contralateral fold. Animals were sacrificed 2 months after treatment. Outcomes measured were procollagen, collagen, and fibronectin levels in the lamina propria, and tissue viscosity and elasticity across three frequency decades. All treatment groups demonstrated accelerated proliferation of the ECM. Vocal fold lamina propria treated with autologous fibroblasts were found to have significantly improved viscosity (p = 0.0077) and elasticity (p = 0.0081) compared to saline. This treatment group had significantly elevated fibronectin levels. sECM and autologous fibroblasts/sECM groups had significantly elevated levels of procollagen, collagen, and fibronectin, indicating abundant matrix production as compared to saline with viscoelastic measures that did not differ statistically from controls. The use of autologous fibroblasts led to better restoration of the vocal fold lamina propria biomechanical properties. Optimization of cell-scaffold interactions and subsequent cell behavior is necessary for utilization of scaffold and scaffold-cell approaches.
NASA Astrophysics Data System (ADS)
Abarca, Elena; Karam, Hanan; Hemond, Harold F.; Harvey, Charles F.
2013-05-01
Detailed field measurements are combined with a numerical modeling to characterize the groundwater dynamics beneath the discharge zone at Waquoit Bay, Massachusetts. Groundwater salinity values revealed a saline circulation cell that overlaid the discharging freshwater and grew and disappeared with the lunar cycle. The cell was initiated by a greater bay water infiltration during the new moon when high tides overtopped the mean high-tide mark, flooding the flatter beach berm and inundating a larger area of the beach. The dynamics of this cell were further characterized by a tracer test and by constructing a density-dependent flow model constrained to salinity and head data. The numerical model captured the growing and diminishing behavior of the circulation cell and provided the estimates of freshwater and saline water fluxes and travel times. Furthermore, the model enabled quantification of the relationship between the characteristics of the observed tidal cycle (maximum, minimum, and mean tidal elevations) and the different components of the groundwater circulation (freshwater discharge, intertidal saline cycling, and deep saline cycling). We found that (1) recharge to the intertidal saline cell is largely controlled by the high-tide elevation; (2) freshwater discharge is positively correlated to the low-tide elevation, whereas deep saline discharge from below the discharging freshwater is negatively correlated to the low-tide elevation. So, when the low-tide elevation is relatively high, more freshwater discharges and less deep saltwater discharges. In contrast when low tides are very low, less freshwater discharges and more deep salt water discharges; (3) offshore inflow of saline water is largely insensitive to tides and the lunar cycle.
Cao, Da; Lutz, Adrian; Hill, Camilla B.; Callahan, Damien L.; Roessner, Ute
2017-01-01
As integral parts of plant signaling networks, phytohormones are involved in the regulation of plant metabolism and growth under adverse environmental conditions, including salinity. Globally, salinity is one of the most severe abiotic stressors with an estimated 800 million hectares of arable land affected. Roots are the first plant organ to sense salinity in the soil, and are the initial site of sodium (Na+) exposure. However, the quantification of phytohormones in roots is challenging, as they are often present at extremely low levels compared to other plant tissues. To overcome this challenge, we developed a high-throughput LC-MS method to quantify ten endogenous phytohormones and their metabolites of diverse chemical classes in roots of barley. This method was validated in a salinity stress experiment with six barley varieties grown hydroponically with and without salinity. In addition to phytohormones, we quantified 52 polar primary metabolites, including some phytohormone precursors, using established GC-MS and LC-MS methods. Phytohormone and metabolite data were correlated with physiological measurements including biomass, plant size and chlorophyll content. Root and leaf elemental analysis was performed to determine Na+ exclusion and K+ retention ability in the studied barley varieties. We identified distinct phytohormone and metabolite signatures as a response to salinity stress in different barley varieties. Abscisic acid increased in the roots of all varieties under salinity stress, and elevated root salicylic acid levels were associated with an increase in leaf chlorophyll content. Furthermore, the landrace Sahara maintained better growth, had lower Na+ levels and maintained high levels of the salinity stress linked metabolite putrescine as well as the phytohormone metabolite cinnamic acid, which has been shown to increase putrescine concentrations in previous studies. This study highlights the importance of root phytohormones under salinity stress and the multi-variety analysis provides an important update to analytical methodology, and adds to the current knowledge of salinity stress responses in plants at the molecular level. PMID:28119732
Ogawa, Sachie; Watanabe, Masahiro; Kawaai, Hiroyoshi; Tada, Hitoshi; Yamazaki, Shinya
2014-01-01
It has been reported that the action of infiltration anesthesia on the jawbone is attenuated significantly by elevation of the periosteal flap with saline irrigation in clinical studies; however, the reason is unclear. Therefore, the lidocaine concentration in mandibular bone after subperiosteal infiltration anesthesia was measured under several surgical conditions. The subjects were 48 rabbits. Infiltration anesthesia by 0.5 mL of 2% lidocaine with 1 : 80,000 epinephrine (adrenaline) was injected into the right mandibular angle and left mandibular body, respectively. Under several surgical conditions (presence or absence of periosteal flap, and presence or absence of saline irrigation), both mandibular bone samples were removed at a fixed time after subperiosteal infiltration anesthesia. The lidocaine concentration in each mandibular bone sample was measured by high-performance liquid chromatography. As a result, elevation of the periosteal flap with saline irrigation significantly decreased the lidocaine concentration in the mandibular bone. It is suggested that the anesthetic in the bone was washed out by saline irrigation. Therefore, supplemental conduction and/or general anesthesia should be utilized for long operations that include elevation of the periosteal flap with saline irrigation. PMID:24932978
Stagg, Camille L.; Baustian, Melissa M.; Perry, Carey L.; Carruthers, Tim J.B.; Hall, Courtney T.
2018-01-01
Coastal wetlands store more carbon than most ecosystems globally. As sea level rises, changes in flooding and salinity will potentially impact ecological functions, such as organic matter decomposition, that influence carbon storage. However, little is known about the mechanisms that control organic matter loss in coastal wetlands at the landscape scale. As sea level rises, how will the shift from fresh to salt-tolerant plant communities impact organic matter decomposition? Do long-term, plant-mediated, effects of sea-level rise differ from direct effects of elevated salinity and flooding?We identified internal and external factors that regulated indirect and direct pathways of sea-level rise impacts, respectively, along a landscape-scale salinity gradient that incorporated changes in wetland type (fresh, oligohaline, mesohaline and polyhaline marshes). We found that indirect and direct impacts of sea-level rise had opposing effects on organic matter decomposition.Salinity had an indirect effect on litter decomposition that was mediated through litter quality. Despite significant variation in environmental conditions along the landscape gradient, the best predictors of above- and below-ground litter decomposition were internal drivers, initial litter nitrogen content and initial litter lignin content respectively. Litter decay constants were greatest in the oligohaline marsh and declined with increasing salinity, and the fraction of litter remaining (asymptote) was greatest in the mesohaline marsh. In contrast, direct effects of salinity and flooding were positive. External drivers, salinity and flooding, stimulated cellulytic activity, which was highest in the polyhaline marsh.Synthesis. Our results indicate that as sea level rises, initial direct effects of salinity will stimulate decay of labile carbon, but over time as plant communities shift from fresh to polyhaline marsh, litter decay will decline, yielding greater potential for long-term carbon storage. These findings highlight the importance of quantifying carbon loss at multiple temporal scales, not only in coastal wetlands but also in other ecosystems where plant-mediated responses to climate change will have significant impacts on carbon cycling.
Swanson
1998-12-01
The euryhaline milkfish (Chanos chanos) is an excellent subject for studies of the physiological and behavioral processes involved in salinity adaptation. In this study, energy partitioning for metabolism, activity and growth, maximal activity performance and blood osmotic concentrations were assessed at two activity levels in juvenile milkfish fed equal rations and maintained at a relatively constant temperature (262 C) and at salinities (15, 35 and 55 ?) that represented a wide range of osmoregulatory challenges. Changes in the measured parameters were not consistently related to the magnitude of the trans-integumentary osmotic gradients. Routine oxygen consumption rates were high in 35 ? salinity (mean 1 s.e.m. 1678 mg O2 kg-1 h-1) and comparably low in 15 and 55 ? salinity (1336 and 1273 mg O2 kg-1 h-1, respectively). Routine activity levels (relative swimming velocity) were highest in 35 ? salinity (0. 960.04 L s-1), where L is standard length, intermediate in 15 ? salinity (0.770.03 L s-1) and lowest in 55 ? salinity (0.670.03 L s-1). Growth was significantly higher in 55 ? salinity (3.40.2 % increase in wet body mass per day) than in 35 ? salinity (2.40.2 % increase per day) and intermediate in 15 ? salinity (2.90.5 % increase per day). Maximum swimming velocities decreased with increases in salinity, from 9.90.7 L s-1 in 15 ? salinity to 6.60. 5 L s-1 in 55 ? salinity. Sustained swimming activity above routine levels for 2 h resulted in an increase in blood osmotic concentrations in milkfish in 55 ? salinity, but osmoregulation was re-established during the second 2 h of activity. Thus, patterns of variation in metabolic rate and growth were largely parallel to variations in routine activity although, comparing 15 and 55 ? salinity, elevated maintenance costs for osmoregulation at the high salinity were detectable. Reduced osmoregulatory abilities and reductions in maximal swimming performance suggest that high salinity may constrain activity. The results demonstrate that investigations of salinity adaptation in euryhaline fishes should take into account the interactive effects of salinity on physiology and behavior.
Catena, Cristiana; Verheyen, Nicolas D; Url-Michitsch, Marion; Kraigher-Krainer, Elisabeth; Colussi, GianLuca; Pilz, Stefan; Tomaschitz, Andreas; Pieske, Burkert; Sechi, Leonardo A
2016-03-01
Left ventricular hypertrophy (LVH) is an independent risk factor for cardiovascular morbidity in hypertension. Current evidence suggests a contribution to LVH of plasma aldosterone levels that are inappropriately elevated for the salt status. The aim of this study was to investigate whether inappropriate modulation of aldosterone production by a saline load is associated with left ventricular (LV) mass in hypertensive patients. In 90 hypertensive patients free of clinically relevant cardiovascular complications in whom secondary forms of hypertension were ruled out, we performed a standard intravenous saline load (0.9% NaCl, 2 l in 4 hours) with measurement of plasma aldosterone and active renin at baseline and end of infusion. Bi-dimensional echocardiography was performed for the assessment of cardiac morphology and function. LVH was present in 19% of patients who had significantly worse renal function and higher body mass, blood pressure, and plasma aldosterone levels measured both at baseline and after the saline load than patients without LVH. LV mass was directly related to age, body mass, systolic blood pressure, duration of hypertension, baseline, and post-saline load plasma aldosterone levels and inversely to glomerular filtration. Multivariate regression analysis showed independent correlation of LV mass with body mass, systolic blood pressure, and plasma aldosterone levels measured after intravenous saline load, but not at baseline. In patients with hypertension, aldosterone levels measured after intravenous saline load are related to LV mass independent of age, body mass, and blood pressure, suggesting that limited ability of salt to modulate aldosterone production could contribute to LVH. © American Journal of Hypertension, Ltd 2015. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
Environmental Flow for Sungai Johor Estuary
NASA Astrophysics Data System (ADS)
Adilah, A. Kadir; Zulkifli, Yusop; Zainura, Z. Noor; Bakhiah, Baharim N.
2018-03-01
Sungai Johor estuary is a vital water body in the south of Johor and greatly affects the water quality in the Johor Straits. In the development of the hydrodynamic and water quality models for Sungai Johor estuary, the Environmental Fluid Dynamics Code (EFDC) model was selected. In this application, the EFDC hydrodynamic model was configured to simulate time varying surface elevation, velocity, salinity, and water temperature. The EFDC water quality model was configured to simulate dissolved oxygen (DO), dissolved organic carbon (DOC), chemical oxygen demand (COD), ammoniacal nitrogen (NH3-N), nitrate nitrogen (NO3-N), phosphate (PO4), and Chlorophyll a. The hydrodynamic and water quality model calibration was performed utilizing a set of site specific data acquired in January 2008. The simulated water temperature, salinity and DO showed good and fairly good agreement with observations. The calculated correlation coefficients between computed and observed temperature and salinity were lower compared with the water level. Sensitivity analysis was performed on hydrodynamic and water quality models input parameters to quantify their impact on modeling results such as water surface elevation, salinity and dissolved oxygen concentration. It is anticipated and recommended that the development of this model be continued to synthesize additional field data into the modeling process.
Szczuka, Aleksandra; Parker, Kimberly M; Harvey, Cassandra; Hayes, Erin; Vengosh, Avner; Mitch, William A
2017-10-01
Coastal utilities exploiting mildly saline groundwater (<150 mg/L chloride) may be challenged by disinfection byproduct (DBP) formation, a concern likely to increase with sea-level rise. Groundwater from North Carolina coastal aquifers is characterized by large variations in concentrations of halides (bromide up to 10,600 μg/L) and dissolved organic carbon (up to 5.7 mg-C/L). Formation of 33 regulated and unregulated halogenated DBPs, including trihalomethanes (THMs), haloacetic acids (HAAs), haloacetonitriles, haloacetamides, and haloacetaldehydes, was measured after simulated chlorination of 24 coastal North Carolina groundwater samples under typical chlorination conditions. Results of chlorination simulation show that THM levels exceeded the Primary Maximum Contaminant Levels in half of the chlorinated samples. Addition of halides to a low salinity groundwater (110 mg/L chloride) indicated that elevated bromide triggered DBP formation, but chloride was not a critical factor for their formation. DBP speciation, but not overall molar formation, was strongly correlated with bromide variations in the groundwater. THMs and HAAs dominated the measured halogenated DBPs on a mass concentration basis. When measured concentrations were weighted by metrics of toxic potency, haloacetonitriles, and to a lesser degree, haloacetaldehydes and HAAs, were the predominant contributors to calculated DBP-associated toxicity. For some samples exhibiting elevated ammonia concentrations, the addition of chlorine to form chloramines in situ significantly reduced halogenated DBP concentrations and calculated toxicity. HAAs dominated the calculated toxicity of chloraminated waters. Reverse osmosis treatment of saline groundwater (chloride >250 mg/L) can reduce DBP formation by removing halides and organic precursors. However, we show that in a case where reverse osmosis permeate is blended with a separate raw groundwater, the residual bromide level in the permeate could still exceed that in the raw groundwater, and thereby induce DBP formation in the blend. DBP-associated calculated toxicity increased for certain blends in this system due to the DBPs resulting from the combination of the elevated bromide concentration in the permeate and the organic precursors from the raw coastal groundwater. Copyright © 2017 Elsevier Ltd. All rights reserved.
Noto, Akana E; Shurin, Jonathan B
2017-01-01
Climate change shuffles species ranges and creates novel interactions that may either buffer communities against climate change or exacerbate its effect. For instance, facilitation can become more prevalent in salt marshes under stressful conditions while competition is stronger in benign environments. Sea-level rise (SLR) is a consequence of climate change that affects the distribution of stress from inundation and salinity. To determine how interactions early in SLR are affected by changes in these two stressors in Mediterranean-climate marshes, we transplanted marsh turfs to lower elevations to simulate SLR and manipulated cover of the dominant plant species, Salicornia pacifica (formerly Salicornia virginica). We found that both S. pacifica and the subordinate species were affected by inundation treatments, and that subordinate species cover and diversity were lower at low elevations in the presence of S. pacifica than when it was removed. These results suggest that the competitive effect of S. pacifica on other plants is stronger at lower tidal elevations where we also found that salinity is reduced. As sea levels rise, stronger competition by the dominant plant will likely reduce diversity and cover of subordinate species, suggesting that stronger species interactions will exacerbate the effects of climate change on the plant community.
Immersing lungs in hydrogen-rich saline attenuates lung ischaemia-reperfusion injury.
Takahashi, Mamoru; Chen-Yoshikawa, Toyofumi F; Saito, Masao; Tanaka, Satona; Miyamoto, Ei; Ohata, Keiji; Kondo, Takeshi; Motoyama, Hideki; Hijiya, Kyoko; Aoyama, Akihiro; Date, Hiroshi
2017-03-01
Anti-oxidant effects of hydrogen have been reported in studies examining ischaemia-reperfusion injury (IRI). In this study, we evaluated the therapeutic efficacy of immersing lungs in hydrogen-rich saline on lung IRI. Lewis rats were divided into three groups: (i) sham, (ii) normal saline and (iii) hydrogen-rich saline. In the first experiment, the left thoracic cavity was filled with either normal saline or hydrogen-rich saline for 1 h. Then, we measured the hydrogen concentration in the left lung using a sensor gas chromatograph ( N = 3 per group). In the second experiment, lung IRI was induced by occlusion of the left pulmonary hilum for 1 h, followed by reperfusion for 3 h. During the ischaemic period, the left thoracic cavity was filled with either normal saline or hydrogen-rich saline. After reperfusion, we assessed lung function, histological changes and cytokine production ( N = 5-7 per group). Immersing lungs in hydrogen-rich saline resulted in an elevated hydrogen concentration in the lung (6.9 ± 2.9 μmol/1 g lung). After IRI, pulmonary function (pulmonary compliance and oxygenation levels) was significantly higher in the hydrogen-rich saline group than in the normal saline group ( P < 0.05). Similarly, pro-inflammatory cytokine levels (interleukin-1β and interleukin-6) in the left lung were significantly lower in the hydrogen-rich saline group than in the normal saline group ( P < 0.05). Immersing lungs in hydrogen-rich saline delivered hydrogen into the lung and consequently attenuated lung IRI. Hydrogen-rich solution appears to be a promising approach to managing lung IRI. © The Author 2016. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.
Towards a theory of ecotone resilience: coastal vegetation on a salinity gradient.
Jiang, Jiang; Gao, Daozhou; DeAngelis, Donald L
2012-08-01
Ecotones represent locations where vegetation change is likely to occur as a result of climate and other environmental changes. Using a model of an ecotone vulnerable to such future changes, we estimated the resilience of the ecotone to disturbances. The specific ecotone is that between two different vegetation types, salinity-tolerant and salinity-intolerant, along a gradient in groundwater salinity. In the case studied, each vegetation type, through soil feedback loops, promoted local soil salinity levels that favor itself in competition with the other type. Bifurcation analysis was used to study the system of equations for the two vegetation types and soil salinity. Alternative stable equilibria, one for salinity-tolerant and one for salinity intolerant vegetation, were shown to exist over a region of the groundwater salinity gradient, bounded by two bifurcation points. This region was shown to depend sensitively on parameters such as the rate of upward infiltration of salinity from groundwater into the soil due to evaporation. We showed also that increasing diffusion rates of vegetation can lead to shrinkage of the range between the two bifurcation points. Sharp ecotones are typical of salt-tolerant vegetation (mangroves) near the coastline and salt-intolerant vegetation inland, even though the underlying elevation and groundwater salinity change very gradually. A disturbance such as an input of salinity to the soil from a storm surge could upset this stable boundary, leading to a regime shift of salinity-tolerant vegetation inland. We showed, however, that, for our model as least, a simple pulse disturbance would not be sufficient; the salinity would have to be held at a high level, as a 'press', for some time. The approach used here should be generalizable to study the resilience of a variety of ecotones to disturbances. Published by Elsevier Inc.
Towards a theory of ecotone resilience: coastal vegetation on a salinity gradient
Jiang, Jiang; Gao, Daozhou; DeAngelis, Donald L.
2012-01-01
Ecotones represent locations where vegetation change is likely to occur as a result of climate and other environmental changes. Using a model of an ecotone vulnerable to such future changes, we estimated the resilience of the ecotone to disturbances. The specific ecotone is that between two different vegetation types, salinity-tolerant and salinity-intolerant, along a gradient in groundwater salinity. In the case studied, each vegetation type, through soil feedback loops, promoted local soil salinity levels that favor itself in competition with the other type. Bifurcation analysis was used to study the system of equations for the two vegetation types and soil salinity. Alternative stable equilibria, one for salinity-tolerant and one for salinity intolerant vegetation, were shown to exist over a region of the groundwater salinity gradient, bounded by two bifurcation points. This region was shown to depend sensitively on parameters such as the rate of upward infiltration of salinity from groundwater into the soil due to evaporation. We showed also that increasing diffusion rates of vegetation can lead to shrinkage of the range between the two bifurcation points. Sharp ecotones are typical of salt-tolerant vegetation (mangroves) near the coastline and salt-intolerant vegetation inland, even though the underlying elevation and groundwater salinity change very gradually. A disturbance such as an input of salinity to the soil from a storm surge could upset this stable boundary, leading to a regime shift of salinity-tolerant vegetation inland. We showed, however, that, for our model as least, a simple pulse disturbance would not be sufficient; the salinity would have to be held at a high level, as a 'press', for some time. The approach used here should be generalizable to study the resilience of a variety of ecotones to disturbances.
Plants and algae mediate important ecosystem processes in coastal marshes and swamps. These assemblages are structured in part by estuarine environmental gradients such as tidal elevation and salinity. Such gradients are likely to change with sea-level rise (SLR) due to global cl...
Labidi, Nehla; Snoussi, Sana; Ammari, Manel; Metoui, Wissal; Ben Yousfi, N; Hamrouni, Lamia; Abdelly, C
2010-12-01
The aim of this study was to identify the relationship between the adaptive processes of Suaeda fruticosa for Pi acquisition and the physic-chemical and biological characteristics of two soil types under moderate and high saline conditions. Four treatments were established in pots: namely SS100, SS600, CS100 and CS600 where SS stood for sandy soil and CS for calcareous soil, and the indexes 100 and 600 were NaCl concentrations (mM) in irrigation distilled water. Assuming that Pi per g of plant biomass is an indicator of plant efficiency for P acquisition, the results showed that Pi acquisition was easiest on SS100 and was difficult on CS100. The differences in Pi acquisition between plants on SS100 and CS100 could be attributed to the low root surface area (-30%) and to the low alkaline phosphatases (Pases) activities (-50%) in calcareous rhizospheric soil. The high salinity level had no effect on the efficiency of P acquisition on SS but increased this parameter on CS (+50%). In the latter soil type, high acid phosphatase activities were observed in rhizospheric soil at high salinity level. Acid phosphatase seemed to be secreted from the roots. The higher secretion of acid phosphatase in this soil was related to the root lipid peroxidation in response to elevated salinity associated with the augmentation of unsaturated acids which might induce an oxidative damage of the root membrane. Thus we can conclude that in deficient soil such as calcareous, the efficiency of P acquisition in S. fruticosa which was difficult at moderate salinity level can be enhanced by high salinity level.
Nyman, J.A.; LaPeyre, Megan K.; Caldwell, Andral W.; Piazza, Sarai C.; Thom, C.; Winslow, C.
2009-01-01
Coastal wetlands provide valued ecosystem functions but the sustainability of those functions often is threatened by artificial hydrologic conditions. It is widely recognized that increased flooding and salinity can stress emergent plants, but there are few measurements to guide restoration, management, and mitigation. Marsh flooding can be estimated over large areas with few data where winds have little effect on water levels, but quantifying flooding requires hourly measurements over long time periods where tides are wind-dominated such as the northern Gulf of Mexico. Estimating salinity of flood water requires direct daily measurements because coastal marshes are characterized by dynamic salinity gradients. We analyzed 399,772 hourly observations of water depth and 521,561 hourly observations of water salinity from 14 sites in Louisiana coastal marshes dominated by Spartina patens (Ait.) Muhl. Unlike predicted water levels, observed water levels varied monthly and annually. We attributed those observed variations to variations in river runoff and winds. In stable marshes with slow wetland loss rates, we found that marsh elevation averaged 1 cm above mean high water, 15 cm above mean water, and 32 cm above mean low water levels. Water salinity averaged 3.7 ppt during April, May, and June, and 5.4 ppt during July, August, and September. The daily, seasonal, and annual variation in water levels and salinity that were evident would support the contention that such variation be retained when designing and operating coastal wetland management and restoration projects. Our findings might be of interest to scientists, engineers, and managers involved in restoration, management, and restoration in other regions where S. patens or similar species are common but local data are unavailable.
Nyman, J.A.; La Peyre, M.K.; Caldwell, A.; Piazza, S.; Thom, C.; Winslow, C.
2009-01-01
Coastal wetlands provide valued ecosystem functions but the sustainability of those functions often is threatened by artificial hydrologic conditions. It is widely recognized that increased flooding and salinity can stress emergent plants, but there are few measurements to guide restoration, management, and mitigation. Marsh flooding can be estimated over large areas with few data where winds have little effect on water levels, but quantifying flooding requires hourly measurements over long time periods where tides are wind-dominated such as the northern Gulf of Mexico. Estimating salinity of flood water requires direct daily measurements because coastal marshes are characterized by dynamic salinity gradients. We analyzed 399,772 hourly observations of water depth and 521,561 hourly observations of water salinity from 14 sites in Louisiana coastal marshes dominated by Spartina patens (Ait.) Muhl. Unlike predicted water levels, observed water levels varied monthly and annually. We attributed those observed variations to variations in river runoff and winds. In stable marshes with slow wetland loss rates, we found that marsh elevation averaged 1 cm above mean high water, 15 cm above mean water, and 32 cm above mean low water levels. Water salinity averaged 3.7 ppt during April, May, and June, and 5.4 ppt during July, August, and September. The daily, seasonal, and annual variation in water levels and salinity that were evident would support the contention that such variation be retained when designing and operating coastal wetland management and restoration projects. Our findings might be of interest to scientists, engineers, and managers involved in restoration, management, and restoration in other regions where S. patens or similar species are common but local data are unavailable. ?? 2009 Elsevier B.V.
Yousefshahi, Fardin; Bashirzadeh, Mona; Abdollahi, Mohammad; Mojtahedzadeh, Mojtaba; Salehiomran, Abbass; Jalali, Arash; Mazandarani, Mahnaz; Zaare, Elmira; Ahadi, Mehdi
2013-01-01
Acute kidney injury (AKI) is a common and life-threatening complication following coronary artery bypass graft (CABG). Neutrophil gelatinase-associated lipocalin (NGAL) and Cystatin C have shown to be good predictive factors for AKI. Recently, there has been a growing interest in the use of hypertonic saline in cardiac operations. The purpose of this study was to evaluate the prophylactic anti-inflammatory effect of hypertonic saline (Group A) infusion versus normal saline (Group B) on serum NGAL and Cystatin C levels as the two biomarkers of AKI in CABG patients. This randomized double-blinded clinical trial recruited 40 patients undergoing CABG in Tehran Heart Center, Tehran, Iran. After applying exclusion criteria, the effects of preoperative hypertonic saline (294 meq Na) versus normal saline (154 meq Na) infusion on serum NGAL and Cystatin C levels were investigated in three intervals: before surgery and 24 and 48 hours postoperatively. The probable intraoperative or postoperative confounders, including pump time, cross-clamp time, heart rate, systolic and diastolic blood pressures, central venous pressure, arterial pH, partial pressure of arterial oxygen, fraction of inspired oxygen, blood sugar, Na, K, Mg, hemoglobins, white blood cells, hematocrits, and platelets, were recorded and compared between the two groups of study. The study population comprised 40 patients, including 25 (62.5%) males, at a, mean age ± SD of 61.75 ± 8.13 years. There were no statistically significant differences between the patients' basic, intraoperative, and postoperative characteristics, including intraoperative and postoperative hemodynamic variables and supports such as inotropic use. Intra-aortic balloon pump use and mortality were not seen in our cases. Three patients in the normal saline group and one patient in the hypertonic saline group had serum NGAL levels greater than 400 ng/ml. Moreover, 10 patients in Group A and 17 patients in group B showed a rise in serum Cystatin C levels above 1.16 mg/dl. Patients with AKI had significantly elevated NGAL and Cystatin C levels (p value < 0.001), but there were no significant differences in the decrease in the NGAL level in the hypertonic saline group versus the normal saline group (230.91 ± 92.68 vs. 239.74 ± 116.58 ng/ml, respectively; p value = 0.792), or in the decrease in the Cystatin C level in the hypertonic saline group versus the normal saline group (1.05 ± 0.26 vs. 1.06 ± 0.31, respectively; p value = 0.874). Pre-treatment of CABG patients with hypertonic saline had no significant effect on serum NGAL and Cystatin C levels compared to the normal saline-receiving group. Our present data, albeit promising, have yet to fully document outcome differences.
Effects of Methane-Rich Saline on the Capability of One-Time Exhaustive Exercise in Male SD Rats
Xin, Lei; Sun, Xuejun; Lou, Shujie
2016-01-01
Purpose To explore the effects of methane-rich saline (CH4 saline) on the capability of one-time exhaustive exercise in male SD rats. Methods Thirty rats were equally divided into to three groups at random: control group (C), placebo group (P) and methane saline group (M). Rats in M group underwent intraperitoneal injection of CH4 saline, and the other two groups simultaneously underwent intraperitoneal injection of normal saline. Then, the exercise capability of rats was tested through one-time exhaustive treadmill exercise except C group. Exercise time and body weight were recorded before and after one-time exhaustive exercise. After exhaustive exercise, the blood and gastrocnemius samples were collected from all rats to detect biochemical parameters in different methods. Results It was found that the treadmill running time was significantly longer in rats treated with CH4 saline. At the same time, CH4 saline reduced the elevation of LD and UN in blood caused by one-time exhaustive exercise. The low level of blood glucose induced by exhaustive exercise was also normalized by CH4 saline. Also CH4 saline lowered the level of CK in plasma. Furthermore, this research indicated that CH4 saline markedly increased the volume of T-AOC in plasma and alleviated the peak of TNF-α in both plasma and gastrocnemius. From H&E staining, CH4 saline effectively improved exercise-induced structural damage in gastrocnemius. Conclusions CH4 saline could enhance exercise capacity in male SD rats through increase of glucose aerobic oxidation, improvement of metabolic clearance and decrease of exhaustive exercise-induced gastrocnemius injury. PMID:26942576
Zaghdoud, Chokri; Carvajal, Micaela; Moreno, Diego A; Ferchichi, Ali; Del Carmen Martínez-Ballesta, María
2016-01-30
The complex interactions between CO2 increase and salinity were investigated in relation to decreased N supply, in order to determine the nutritional quality of broccoli (Brassica oleracea L. var. italica) plants under these conditions. Three different decreased N fertilisation regimes (NO3(-)/NH4(+) ratios of 100:0, 50:50 and 0:100 respectively) were combined with ambient (380 ppm) and elevated (800 ppm) [CO2 ] under non-saline (0 mmol L(-1) NaCl) and saline (80 mmol L(-1) NaCl) conditions. Nutrients (minerals, soluble protein and total amino acids) and natural antioxidants (glucosinolates, phenolic acids, flavonoids and vitamin C) were determined. In NH4(+) -fed broccoli plants, a marked growth reduction was shown and a redistribution of amino acids to cope with NH4(+) toxicity resulted in higher levels of indolic glucosinolate and total phenolic compounds. However, the positive effect of the higher [CO2] - ameliorating adverse effects of salinity--was only observed when N was supplied as NO3(-). Under reduced N fertilisation, the total glucosinolates were increased by a decreased NO3(-)/NH4 (+) ratio and elevated [CO2] but were unaffected by salinity. Under future climatic challenges, such as increased salinity and elevated [CO2], a clear genotypic dependence of S metabolism was observed in broccoli plants. In addition, an influence of the form in which N was supplied on plant nutritional quality was observed; a combined NO3(-)/NH4(+) (50:50) supply allowed broccoli plants not only to deal with NH4(+) toxicity but also to modify their glucosinolate content and profile. Thus, for different modes of N fertilisation, the interaction with climatic factors must be considered in the search for an optimal balance between yield and nutritional quality. © 2015 Society of Chemical Industry.
Capsaicin pre- and post-treatment on rat monocrotaline pneumotoxicity.
Katzman, N J; Lai, Y L
2000-12-31
Monocrotaline (MCT) produces respiratory dysfunction, pulmonary hypertension (PH), and right ventricular hypertrophy (RVH) in rats. Tachykinins, such as substance P (SP) and neurokinin A (NKA), may mediate these effects. The purpose of this study was to investigate the length of tachykinin depletion (via capsaicin treatment) is needed to prevent (or attenuate) PH and/or RVH. Six groups of rats were injected subcutaneously with saline (3 ml/kg); capsaicin followed by saline or MCT (60 mg/kg); or MCT followed 7, 11, or 14 days later by capsaicin. Capsaicin (cumulative dose, 500 mg/kg) was given over a period of 4-5 days. Respiratory function, pulmonary vascular parameters, lung tachykinin levels, and tracheal neutral endopeptidase (NEP) activity were measured 21 days after MCT or saline injection. Capsaicin significantly decreased lung levels of SP but not NKA. Both capsaicin pretreatment and posttreatment blocked the following MCT-induced alterations: increases in lung SP and airway constriction; decreases in tracheal NEP activity and dynamic respiratory compliance. Administration of capsaicin before or 7 days after MCT blocked MCT-induced PH and RVH. The above data suggest that the early tachykinin-mediated airway dysfunction requires only transient elevated tachykinins, while progression of late tachykinin-mediated effects (PH and RVH) requires elevated tachykinins for more than one week.
Drake, Bert G
2014-11-01
An ongoing field study of the effects of elevated atmospheric CO2 on a brackish wetland on Chesapeake Bay, started in 1987, is unique as the longest continually running investigation of the effects of elevated CO2 on an ecosystem. Since the beginning of the study, atmospheric CO2 increased 18%, sea level rose 20 cm, and growing season temperature varied with approximately the same range as predicted for global warming in the 21st century. This review looks back at this study for clues about how the effects of rising sea level, temperature, and precipitation interact with high atmospheric CO2 to alter the physiology of C3 and C4 photosynthetic species, carbon assimilation, evapotranspiration, plant and ecosystem nitrogen, and distribution of plant communities in this brackish wetland. Rising sea level caused a shift to higher elevations in the Scirpus olneyi C3 populations on the wetland, displacing the Spartina patens C4 populations. Elevated CO2 stimulated carbon assimilation in the Scirpus C3 species measured by increased shoot and root density and biomass, net ecosystem production, dissolved organic and inorganic carbon, and methane production. But elevated CO2 also decreased biomass of the grass, S. patens C4. The elevated CO2 treatment reduced tissue nitrogen concentration in shoots, roots, and total canopy nitrogen, which was associated with reduced ecosystem respiration. Net ecosystem production was mediated by precipitation through soil salinity: high salinity reduced the CO2 effect on net ecosystem production, which was zero in years of severe drought. The elevated CO2 stimulation of shoot density in the Scirpus C3 species was sustained throughout the 28 years of the study. Results from this study suggest that rising CO2 can add substantial amounts of carbon to ecosystems through stimulation of carbon assimilation, increased root exudates to supply nitrogen fixation, reduced dark respiration, and improved water and nitrogen use efficiency. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.
NASA Astrophysics Data System (ADS)
Ji, Chenglong; Wu, Huifeng; Liu, Xiaoli; Zhao, Jianmin; Yu, Junbao; Yin, Xiuli
2013-03-01
Ruditapes philippinarum, a clam that thrives in intertidal zones of various salinities, is a useful biomonitor to marine contaminants. We investigated the influence of dilution to 75% and 50% of normal seawater salinity (31.1) on the responses of the digestive gland of R. philippinarum to arsenic exposure (20 μg/L), using nuclear magnetic resonance (NMR)-based metabolomics. After acute arsenic exposure for 48 h, salinity-dependent differential metabolic responses were detected. In normal seawater, arsenic exposure increased the concentrations of branched-chain amino acids, and of threonine, proline, phosphocholine and adenosine, and it decreased the levels of alanine, hypotaurine, glucose, glycogen and ATP in the digestive glands. Differential changes in metabolic biomarkers observed at lower salinity (˜23.3) included elevation of succinate, taurine and ATP, and depletion of branched-chain amino acids, threonine and glutamine. Unique effects of arsenic at the lowest salinity (˜15.6) included down-regulation of glutamate, succinate and ADP, and up-regulation of phosphocholine. We conclude that salinity influences the metabolic responses of this clam to arsenic.
Responses of the brackish-water amphipod Gammarus duebeni (crustacea) to saline sewage
NASA Astrophysics Data System (ADS)
Jones, M. B.; Johnson, I.
Soon after the openiing of the Looe sewage treatment works (Cornwall, southwest England) in 1973, it became colonized by the brackish-water amphipod Gammarus duebeni Liljeborg. The works is unusual as it operates with saline sewage and has a tidally-based pattern of salinity fluctuation (S=13 to 34). Various responses of this unique amphipod population (sewage amphipods) have been compared with G. duebeni from the adjacent Looe River estuary (estuarine amphipods) in an attempt to identify long-term responses to sewage. Sewage amphipods were significantly smaller than their estuarine equivalents; the sewage population was biased significantly to males, whereas the sex ratio of the estuarine population significantly favours females. Compared with the estuary, the consistently lower oxygen levels in the works were reflected in significant differences in metabolism. Sewage amphipods maintained high levels of activity under hypoxia ( e.g. swimming), and the higher survival and lower rates of lactic acid accumulation under anoxia than estuarine individuals. In addition, sewage amphipods recovered more rapidly from anoxia and had a lower critical oxygen tension (p c) than estuarine amphipods. Sewage amphipods are exposed to higher levels of heavy metals associated with the domestic sewage and zinc concentrations are particularly elevated in the works. Exposure to elevated zinc concentrations resulted in similar patterns of body zinc uptake for sewage and estuarine Gammarus at high (30) and low (10) salinity, with zinc regulation apparently occuring to an external threshold of 200 γmgZn·dm -3. No consistent interpopulational differences in the effect ofzinc on zinc uptake or on osmoregulation have been identified. However, sewage amphipods had higher survival at all zinc/salinity combinations compared with estuarine individuals. These indicate that sewage amphipods are adapted to the unusual combination of conditions prevailing in the treatment works and, if reproductive isolation is confirmed, suggest that the speciation process may have commenced.
Svensson, Filip; Norberg, Jon; Snoeijs, Pauline
2014-01-01
Reduction in body size has been proposed as a universal response of organisms, both to warming and to decreased salinity. However, it is still controversial if size reduction is caused by temperature or salinity on their own, or if other factors interfere as well. We used natural benthic diatom communities to explore how “body size” (cells and colonies) and motility change along temperature (2–26°C) and salinity (0.5–7.8) gradients in the brackish Baltic Sea. Fourth-corner analysis confirmed that small cell and colony sizes were associated with high temperature in summer. Average community cell volume decreased linearly with 2.2% per °C. However, cells were larger with artificial warming when nutrient concentrations were high in the cold season. Average community cell volume increased by 5.2% per °C of artificial warming from 0 to 8.5°C and simultaneously there was a selection for motility, which probably helped to optimize growth rates by trade-offs between nutrient supply and irradiation. Along the Baltic Sea salinity gradient cell size decreased with decreasing salinity, apparently mediated by nutrient stoichiometry. Altogether, our results suggest that climate change in this century may polarize seasonality by creating two new niches, with elevated temperature at high nutrient concentrations in the cold season (increasing cell size) and elevated temperature at low nutrient concentrations in the warm season (decreasing cell size). Higher temperature in summer and lower salinity by increased land-runoff are expected to decrease the average cell size of primary producers, which is likely to affect the transfer of energy to higher trophic levels. PMID:25279720
Svensson, Filip; Norberg, Jon; Snoeijs, Pauline
2014-01-01
Reduction in body size has been proposed as a universal response of organisms, both to warming and to decreased salinity. However, it is still controversial if size reduction is caused by temperature or salinity on their own, or if other factors interfere as well. We used natural benthic diatom communities to explore how "body size" (cells and colonies) and motility change along temperature (2-26°C) and salinity (0.5-7.8) gradients in the brackish Baltic Sea. Fourth-corner analysis confirmed that small cell and colony sizes were associated with high temperature in summer. Average community cell volume decreased linearly with 2.2% per °C. However, cells were larger with artificial warming when nutrient concentrations were high in the cold season. Average community cell volume increased by 5.2% per °C of artificial warming from 0 to 8.5°C and simultaneously there was a selection for motility, which probably helped to optimize growth rates by trade-offs between nutrient supply and irradiation. Along the Baltic Sea salinity gradient cell size decreased with decreasing salinity, apparently mediated by nutrient stoichiometry. Altogether, our results suggest that climate change in this century may polarize seasonality by creating two new niches, with elevated temperature at high nutrient concentrations in the cold season (increasing cell size) and elevated temperature at low nutrient concentrations in the warm season (decreasing cell size). Higher temperature in summer and lower salinity by increased land-runoff are expected to decrease the average cell size of primary producers, which is likely to affect the transfer of energy to higher trophic levels.
NASA Astrophysics Data System (ADS)
Sanders, Christian J.; Santos, Isaac R.; Barcellos, Renato; Silva Filho, Emmanoel V.
2012-07-01
Groundwater underlying a mangrove habitat was studied to determine the geochemical nature of Ba, Fe and Mn as related to dissolved organic carbon (DOC), SO4 and salinity (Sepetiba Bay, Brazil). Wells were placed across geobotanic facies and sampled monthly for a year. We observed non-conservative behavior and elevated concentrations of dissolved metals relative to local end-members (i.e., fresh river water and seawater). Average Ba concentrations were near 2000 nM in an area with low salinity (˜5.3). Dissolved Fe (up to 654 μM) was two orders of magnitude greater in fresh groundwater than in the seaward sampling stations. Manganese concentrations were greatest (112 μM) in the high salinity (˜65) zone, being directly influenced by salinity. Groundwater Ba, Fe and Mn showed differing site specific concentrations, likely related to ion exchange processes and redox-controlled cycling along distinct mangrove facies. The results of this work show that metal concentrations are altered relative to conservative mixing between terrestrial and marine endmembers, illustrating the importance of mangrove subterranean estuaries as biogeochemical reactors. Roughly-estimated submarine groundwater discharge-derived dissolved Ba, Fe and Mn fluxes were at least one order of magnitude greater than river-derived fluxes into Sepetiba Bay.
Stagg, Camille L.; Schoolmaster, Donald; Krauss, Ken W.; Cormier, Nicole; Conner, William H.
2017-01-01
Coastal wetlands significantly contribute to global carbon storage potential. Sea-level rise and other climate change-induced disturbances threaten coastal wetland sustainability and carbon storage capacity. It is critical that we understand the mechanisms controlling wetland carbon loss so that we can predict and manage these resources in anticipation of climate change. However, our current understanding of the mechanisms that control soil organic matter decomposition, in particular the impacts of elevated salinity, are limited, and literature reports are contradictory. In an attempt to improve our understanding of these complex processes, we measured root and rhizome decomposition and developed a causal model to identify and quantify the mechanisms that influence soil organic matter decomposition in coastal wetlands that are impacted by sea-level rise. We identified three causal pathways: 1) a direct pathway representing the effects of flooding on soil moisture, 2) a direct pathway representing the effects of salinity on decomposer microbial communities and soil biogeochemistry, and 3) an indirect pathway representing the effects of salinity on litter quality through changes in plant community composition over time. We used this model to test the effects of alternate scenarios on the response of tidal freshwater forested wetlands and oligohaline marshes to short- and long-term climate-induced disturbances of flooding and salinity. In tidal freshwater forested wetlands, the model predicted less decomposition in response to drought, hurricane salinity pulsing, and long-term sea-level rise. In contrast, in the oligohaline marsh, the model predicted no change in response to sea-level rise, and increased decomposition following a drought or a hurricane salinity pulse. Our results show that it is critical to consider the temporal scale of disturbance and the magnitude of exposure when assessing the effects of salinity intrusion on carbon mineralization in coastal wetlands. Here we identify three causal mechanisms that can reconcile disparities between long-term and short-term salinity impacts on organic matter decomposition.
Stagg, Camille L; Schoolmaster, Donald R; Krauss, Ken W; Cormier, Nicole; Conner, William H
2017-08-01
Coastal wetlands significantly contribute to global carbon storage potential. Sea-level rise and other climate-change-induced disturbances threaten coastal wetland sustainability and carbon storage capacity. It is critical that we understand the mechanisms controlling wetland carbon loss so that we can predict and manage these resources in anticipation of climate change. However, our current understanding of the mechanisms that control soil organic matter decomposition, in particular the impacts of elevated salinity, are limited, and literature reports are contradictory. In an attempt to improve our understanding of these complex processes, we measured root and rhizome decomposition and developed a causal model to identify and quantify the mechanisms that influence soil organic matter decomposition in coastal wetlands that are impacted by sea-level rise. We identified three causal pathways: (1) a direct pathway representing the effects of flooding on soil moisture, (2) a direct pathway representing the effects of salinity on decomposer microbial communities and soil biogeochemistry, and (3) an indirect pathway representing the effects of salinity on litter quality through changes in plant community composition over time. We used this model to test the effects of alternate scenarios on the response of tidal freshwater forested wetlands and oligohaline marshes to short- and long-term climate-induced disturbances of flooding and salinity. In tidal freshwater forested wetlands, the model predicted less decomposition in response to drought, hurricane salinity pulsing, and long-term sea-level rise. In contrast, in the oligohaline marsh, the model predicted no change in response to drought and sea-level rise, and increased decomposition following a hurricane salinity pulse. Our results show that it is critical to consider the temporal scale of disturbance and the magnitude of exposure when assessing the effects of salinity intrusion on carbon mineralization in coastal wetlands. Here, we identify three causal mechanisms that can reconcile disparities between long-term and short-term salinity impacts on organic matter decomposition. © 2017 by the Ecological Society of America.
Sea level rise due to global climate change may affect the spatial distribution of plants and macroalgae within tidal estuaries. We present preliminary results from on-going research in Oregon to determine how these potential abiotic drives correlate with the presence or absence...
Tidal wetlands support important ecosystem functions along the coast of the Pacific Northwest such as primary production and nutrient transformation. Sea-level rise (SLR) and elevated salinity due to climate change may affect the abundance, distribution, and diversity of plants a...
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lin Wu; Zhang-Zhi Huang
The discovery of high levels of Se in soil and water samples from the San Joaquin Valley, California, and of its responsibility for deformity and death of wildlife at Kesterson National Wildlife Refuge have renewed interest in the bioaccumulation of this element. Greenhouse nutrient solution culture and field experiments were conducted to examine the effects of Cl and SO{sub 4} salt on growth and Se accumulation in tall fescue (Festuca arundinacea Schreb.) cultivars Alta, Falcon, and Olympic. Sulfate salt substantially reduced growth inhibition and Se accumulation. Tall fescue from the field irrigated with water low in salinity had higher tissuemore » Se concentration than plants from the field irrigated with water high in salinity. No difference in tissue Se concentration was found among the three tall fescue cultivars; however, forage-type Alta produced the most shoot biomass and accumulated the most total Se. The soil irrigated with water high in salinity had 10 times higher Se concentration than soil irrigated with water low in salinity. The highest soil Se concentration was found in the top 15 cm of soil. Growing fescue for one year reduced soil Se by 50%. Selenium concentrations below 15-cm depth were lower and similar between the bare soil and the soil under tall fescue. Both the high and low salinity water irrigations did not cause high levels of Se accumulation by the tall fescue cultivars unless there was continual addition of Se into the system. This study generated important information for Se bioaccumulation management in soils with elevated salinity and Se levels.« less
NASA Astrophysics Data System (ADS)
Akkurt, David; Akay, Yasemin M.; Akay, Metin
2009-10-01
In this paper, we examined the effect of nicotine exposure and increased body temperature on the complexity (dynamics) of the genioglossus muscle (EMGg) and the diaphragm muscle (EMGdia) to explore the effects of nicotine and hyperthermia. Nonlinear dynamical analysis of the EMGdia and EMGg signals was performed using the approximate entropy method on 15 (7 saline- and 8 nicotine-treated) juvenile rats (P25-P35) and 19 (11 saline- and 8 nicotine-treated) young adult rats (P36-P44). The mean complexity values were calculated over the ten consecutive breaths using the approximate entropy method during mild elevated body temperature (38 °C) and severe elevated body temperature (39-40 °C) in two groups. In the first (nicotine) group, rats were treated with single injections of nicotine enough to produce brain levels of nicotine similar to those achieved in human smokers (2.5 (mg kg-1)/day) until the recording day. In the second (control) group, rats were treated with injections of saline, beginning at postnatal 5 days until the recording day. Our results show that warming the rat by 2-3 °C and nicotine exposure significantly decreased the complexity of the EMGdia and EMGg for the juvenile age group. This reduction in the complexity of the EMGdia and EMGg for the nicotine group was much greater than the normal during elevated body temperatures. We speculate that the generalized depressive effects of nicotine exposure and elevated body temperature on the respiratory neural firing rate and the behavior of the central respiratory network could be responsible for the drastic decrease in the complexity of the EMGdia and EMGg signals, the outputs of the respiratory neural network during early maturation.
Yousefshahi, Fardin; Bashirzadeh, Mona; Abdollahi, Mohammad; Mojtahedzadeh, Mojtaba; Salehiomran, Abbass; Jalali, Arash; Mazandarani, Mahnaz; Zaare, Elmira; Ahadi, Mehdi
2013-01-01
Background: Acute kidney injury (AKI) is a common and life-threatening complication following coronary artery bypass graft (CABG). Neutrophil gelatinase-associated lipocalin (NGAL) and Cystatin C have shown to be good predictive factors for AKI. Recently, there has been a growing interest in the use of hypertonic saline in cardiac operations. The purpose of this study was to evaluate the prophylactic anti-inflammatory effect of hypertonic saline (Group A) infusion versus normal saline (Group B) on serum NGAL and Cystatin C levels as the two biomarkers of AKI in CABG patients. Methods: This randomized double-blinded clinical trial recruited 40 patients undergoing CABG in Tehran Heart Center, Tehran, Iran. After applying exclusion criteria, the effects of preoperative hypertonic saline (294 meq Na) versus normal saline (154 meq Na) infusion on serum NGAL and Cystatin C levels were investigated in three intervals: before surgery and 24 and 48 hours postoperatively. The probable intraoperative or postoperative confounders, including pump time, cross-clamp time, heart rate, systolic and diastolic blood pressures, central venous pressure, arterial pH, partial pressure of arterial oxygen, fraction of inspired oxygen, blood sugar, Na, K, Mg, hemoglobins, white blood cells, hematocrits, and platelets, were recorded and compared between the two groups of study. Results: The study population comprised 40 patients, including 25 (62.5%) males, at a, mean age ± SD of 61.75 ± 8.13 years. There were no statistically significant differences between the patients’ basic, intraoperative, and postoperative characteristics, including intraoperative and postoperative hemodynamic variables and supports such as inotropic use. Intra-aortic balloon pump use and mortality were not seen in our cases. Three patients in the normal saline group and one patient in the hypertonic saline group had serum NGAL levels greater than 400 ng/ml. Moreover, 10 patients in Group A and 17 patients in group B showed a rise in serum Cystatin C levels above 1.16 mg/dl. Patients with AKI had significantly elevated NGAL and Cystatin C levels (p value < 0.001), but there were no significant differences in the decrease in the NGAL level in the hypertonic saline group versus the normal saline group (230.91 ± 92.68 vs. 239.74 ± 116.58 ng/ml, respectively; p value = 0.792), or in the decrease in the Cystatin C level in the hypertonic saline group versus the normal saline group (1.05 ± 0.26 vs. 1.06 ± 0.31, respectively; p value = 0.874). Conclusion: Pre-treatment of CABG patients with hypertonic saline had no significant effect on serum NGAL and Cystatin C levels compared to the normal saline-receiving group. Our present data, albeit promising, have yet to fully document outcome differences. PMID:23646044
Yin, Yong-Gen; Kobayashi, Yoshie; Sanuki, Atsuko; Kondo, Satoru; Fukuda, Naoya; Ezura, Hiroshi; Sugaya, Sumiko; Matsukura, Chiaki
2010-01-01
Salinity stress enhances sugar accumulation in tomato (Solanum lycopersicum) fruits. To elucidate the mechanisms underlying this phenomenon, the transport of carbohydrates into tomato fruits and the regulation of starch synthesis during fruit development in tomato plants cv. ‘Micro-Tom’ exposed to high levels of salinity stress were examined. Growth with 160 mM NaCl doubled starch accumulation in tomato fruits compared to control plants during the early stages of development, and soluble sugars increased as the fruit matured. Tracer analysis with 13C confirmed that elevated carbohydrate accumulation in fruits exposed to salinity stress was confined to the early development stages and did not occur after ripening. Salinity stress also up-regulated sucrose transporter expression in source leaves and increased activity of ADP-glucose pyrophosphorylase (AGPase) in fruits during the early development stages. The results indicate that salinity stress enhanced carbohydrate accumulation as starch during the early development stages and it is responsible for the increase in soluble sugars in ripe fruit. Quantitative RT-PCR analyses of salinity-stressed plants showed that the AGPase-encoding genes, AgpL1 and AgpS1 were up-regulated in developing fruits, and AgpL1 was obviously up-regulated by sugar at the transcriptional level but not by abscisic acid and osmotic stress. These results indicate AgpL1 and AgpS1 are involved in the promotion of starch biosynthesis under the salinity stress in ABA- and osmotic stress-independent manners. These two genes are differentially regulated at the transcriptional level, and AgpL1 is suggested to play a regulatory role in this event. PMID:19995825
1989-11-01
hepatic changes. The magnitude of the enzyme elevations, subsequent decreases in ALK and ALT levels, and -e absence of morphologic changes in the liver...of PT and A-PTT are not uncommon findings in severe, acute, hepatopathies in dogs (17). The increases in hepatic enzymes observed in HSD- and D70...clinical signs referable to liver disease, and the lack of .eaato lesions on histopathological examination, suggest tat the enzyme elevations may have
Li, Yuqian; Li, Zhihong; Li, Min; Yang, Yanlong; Wang, Bao; Gao, Li; Zhang, Xingye; Cheng, Hongyu; Fang, Wei; Zhao, Bo; Wang, Boliang; Gao, Guodong; Li, Lihong
2015-06-17
Elevated intracranial pressure is one of the most common problems in patients with diverse intracranial disorders, leading to increased morbidity and mortality. Effective management for increased intracranial pressure is based mainly on surgical and medical techniques with hyperosmolar therapy as one of the core medical treatments. The study aimed to explore the effects of continuous micro-pump infusions of 3% hypertonic saline combined with furosemide on intracranial pressure control. We analyzed data on 56 eligible participants with intracranial pressure >20 mmHg from March 2013 to July 2014. The target was to increase and maintain plasma sodium to a level between 145 and 155 mmol/L and osmolarity to a level of 310 to 320 mOsmol/kg. Plasma sodium levels significantly increased from 138±5 mmol/L at admission to 151±3 mmol/L at 24 h (P<0.01). Osmolarity increased from 282±11 mOsmol/kg at baseline to 311±8 mOsmol/kg at 24 h (P<0.01). Intracranial pressure significantly decreased from 32±7 mmHg to 15±6 mmHg at 24 h (P<0.01). There was a significant improvement in CPP (P<0.01). Moreover, central venous pressure, mean arterial pressure, and Glasgow Coma Scale slightly increased. However, these changes were not statistically significant. Continuous infusion of 3% hypertonic saline + furosemide is effective and safe for intracranial pressure control.
Yamaoka, Ippei; Mikura, Mayumi; Nishimura, Masuhiro; Doi, Masako; Kawano, Yuichi; Nakayama, Mitsuo
2008-12-01
Administration of an amino acid (AA) mixture stimulates muscle protein synthesis and elevates core body temperature (T(b)), as characteristically found under anesthetic conditions. We tested the hypothesis that not only AA given, but also AA produced by degradation of endogenous muscular protein are provided for muscle protein synthesis, which is further reflected in T(b) modifications. Rats were intravenously administered an AA mixture or saline in combination with the anesthetic propofol or lipid emulsion. We measured plasma 3-methylhistidine (MeHis) concentrations as an index of myofibrillar protein degradation, rectal temperature and mRNA expression of atrogin-1, MuRF-1 and ubiquitin in gastrocnemius and soleus muscles of rats following 3 h infusion of test solutions. T(b) did not differ significantly between conscious groups, but was higher in the AA group than in the saline group among anesthetized rats. Plasma MeHis concentrations were higher in the AA group than in the saline group under both conditions. Plasma MeHis levels correlated positively with T(b) of rats under both conditions. AA administration decreased mRNA levels of atrogin-1 and ubiquitin in gastrocnemius muscle and all mRNA levels in soleus muscle. These results suggest that AA administration enhances myofibrillar protein degradation and that the change is a determinant of T(b) modification by AA administration. However, the mechanisms underlying AA administration-associated enhancement of myofibrillar proteolysis remains yet to be determined.
Rapamycin blocks the antidepressant effect of ketamine in task-dependent manner.
Holubova, Kristina; Kleteckova, Lenka; Skurlova, Martina; Ricny, Jan; Stuchlik, Ales; Vales, Karel
2016-06-01
The aim of our study was to test whether ketamine produces an antidepressant effect in animal model of olfactory bulbectomy and assess the role of mammalian target of rapamycin (mTOR) pathway in ketamine's antidepressant effect. Bulbectomized (OBX) rats and sham controls were assigned to four subgroups according to the treatment they received (ketamine, saline, ketamine + rapamycin, and saline + rapamycin). The animals were subjected to open field (OF), elevated plus maze (EPM), passive avoidance (PA), Morris water maze (MWM), and Carousel maze (CM) tests. Blood samples were collected before and after drug administration for analysis of phosphorylated mTOR level. After behavioral testing, brains were removed for evaluation of brain-derived neurotrophic factor (BDNF) in prefrontal cortex (PFC) and hippocampus. Ketamine normalized hyperactivity of OBX animals in EPM and increased the time spent in open arms. Rapamycin pretreatment resulted in elimination of ketamine effect in EPM test. In CM test, ketamine + rapamycin administration led to cognitive impairment not observed in saline-, ketamine-, or saline + rapamycin-treated OBX rats. Prefrontal BDNF content was significantly decreased, and level of mTOR was significantly elevated in OBX groups. OBX animals significantly differed from sham controls in most of the tests used. Treatment had more profound effect on OBX phenotype than controls. Pretreatment with rapamycin eliminated the anxiolytic and antidepressant effects of ketamine in task-dependent manner. The results indicate that ketamine + rapamycin application resulted in impaired stress responses manifested by cognitive deficits in active place avoidance (CM) test. Intensity of stressor (mild vs. severe) used in the behavioral tests had opposite effect on controls and on OBX animals.
Waditee-Sirisattha, Rungaroon; Kageyama, Hakuto; Fukaya, Minoru; Rai, Vandna; Takabe, Teruhiro
2015-12-01
A halotolerant cyanobacterium Aphanothece halophytica thrives in extreme salinity with accumulation of a potent osmoprotectant glycine betaine. Recently, this cyanobacterium was shown to accumulate sunscreen molecule mycosporine-2-glycine significantly at high salinity. In this study, we investigated effects of nitrate and amino acid provision on the accumulation of glycine betaine and mycosporine-2-glycine. With elevated nitrate concentrations at high salinity, intracellular levels of both metabolites were enhanced. Six-fold high nitrate concentration increased the relative amounts of glycine betaine and mycosporine-2-glycine to be 1.5 and 2.0 folds compared with control condition : Increased levels were time- and dose-dependent manner. Exogenous supply of glycine/serine at high salinity resulted in the similar trends as observed in excess nitrate experiment. Intracellular level of glycine betaine increased ∼1.6 folds with glycine/serine supplementation. These supplementations also caused the increased level of mycosporine-2-glycine, namely 1.4 and 2 folds by glycine and serine, respectively. The transcription of glycine betaine and mycosporine-2-glycine biosynthetic genes was strongly induced under high-nitrate-salt condition. These results suggest the dependence of glycine betaine and mycosporine-2-glycine productions on substrate availability, and the effect of nitrate was possibly associated with stimulation of osmoprotectant increment in this extremophile. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
Global Ocean Forecast System (GOFS) Version 2.6. User’s Manual
2010-03-31
odimens.D, which takes the rivers.dat flow levels, inputs an SST and sea surface salinity (SSS) climatology from GDEM , and outputs the orivs_1.D...Center for Medium-range Weather Forecast GB GigaByte GDEM Global Digital Elevation Map GOFS Global Ocean Forecast System HPCMP High Performance
Elevational dependence of projected hydrologic changes in the San Francisco Estuary and watershed
Knowles, N.; Cayan, D.R.
2004-01-01
California's primary hydrologic system, the San Francisco Estuary and its upstream watershed, is vulnerable to the regional hydrologic consequences of projected global climate change. Previous work has shown that a projected warming would result in a reduction of snowpack storage leading to higher winter and lower spring-summer streamflows and increased spring-summer salinities in the estuary. The present work shows that these hydrologic changes exhibit a strong dependence on elevation, with the greatest loss of snowpack volume in the 1300-2700 m elevation range. Exploiting hydrologic and estuarine modeling capabilities to trace water as it moves through the system reveals that the shift of water in mid-elevations of the Sacramento river basin from snowmelt to rainfall runoff is the dominant cause of projected changes in estuarine inflows and salinity. Additionally, although spring-summer losses of estuarine inflows are balanced by winter gains, the losses have a stronger influence on salinity since longer spring-summer residence times allow the inflow changes to accumulate in the estuary. The changes in inflows sourced in the Sacramento River basin in approximately the 1300-2200 m elevation range thereby lead to a net increase in estuarine salinity under the projected warming. Such changes would impact ecosystems throughout the watershed and threaten to contaminate much of California's freshwater supply.
Salinity Adaptation and the Contribution of Parental Environmental Effects in Medicago truncatula
Moriuchi, Ken S.; Friesen, Maren L.; Cordeiro, Matilde A.; Badri, Mounawer; Vu, Wendy T.; Main, Bradley J.; Aouani, Mohamed Elarbi; Nuzhdin, Sergey V.; Strauss, Sharon Y.; von Wettberg, Eric J. B.
2016-01-01
High soil salinity negatively influences plant growth and yield. Some taxa have evolved mechanisms for avoiding or tolerating elevated soil salinity, which can be modulated by the environment experienced by parents or offspring. We tested the contribution of the parental and offspring environments on salinity adaptation and their potential underlying mechanisms. In a two-generation greenhouse experiment, we factorially manipulated salinity concentrations for genotypes of Medicago truncatula that were originally collected from natural populations that differed in soil salinity. To compare population level adaptation to soil salinity and to test the potential mechanisms involved we measured two aspects of plant performance, reproduction and vegetative biomass, and phenological and physiological traits associated with salinity avoidance and tolerance. Saline-origin populations had greater biomass and reproduction under saline conditions than non-saline populations, consistent with local adaptation to saline soils. Additionally, parental environmental exposure to salt increased this difference in performance. In terms of environmental effects on mechanisms of salinity adaptation, parental exposure to salt spurred phenological differences that facilitated salt avoidance, while offspring exposure to salt resulted in traits associated with greater salt tolerance. Non-saline origin populations expressed traits associated with greater growth in the absence of salt while, for saline adapted populations, the ability to maintain greater performance in saline environments was also associated with lower growth potential in the absence of salt. Plastic responses induced by parental and offspring environments in phenology, leaf traits, and gas exchange contribute to salinity adaptation in M. truncatula. The ability of plants to tolerate environmental stress, such as high soil salinity, is likely modulated by a combination of parental effects and within-generation phenotypic plasticity, which are likely to vary in populations from contrasting environments. PMID:26943813
The effect of drinking water salinity on blood pressure in young adults of coastal Bangladesh.
Talukder, Mohammad Radwanur Rahman; Rutherford, Shannon; Phung, Dung; Islam, Mohammad Zahirul; Chu, Cordia
2016-07-01
More than 35 million people in coastal Bangladesh are vulnerable to increasing freshwater salinization. This will continue to affect more people and to a greater extent as climate change projections are realised in this area in the future. However the evidence for health effects of consuming high salinity water is limited. This research examined the association between drinking water salinity and blood pressure in young adults in coastal Bangladesh. We conducted a cross-sectional study during May-June 2014 in a rural coastal sub-district of Bangladesh. Data on blood pressure (BP) and salinity of potable water sources was collected from 253 participants aged 19-25 years. A linear regression method was used to examine the association between water salinity exposure categories and systolic BP (SBP) and diastolic BP (DBP) level. Sixty five percent of the study population were exposed to highly saline drinking water above the Bangladesh standard (600 mg/L and above). Multivariable linear regression analyses identified that compared to the low water salinity exposure category (<600 mg/L), those in the high water salinity category (>600 mg/L), had statistically significantly higher SBP (B 3.46, 95% CI 0.75, 6.17; p = 0.01) and DBP (B 2.77, 95% CI 0.31, 5.24; p = 0.03). Our research shows that elevated salinity in drinking water is associated with higher BP in young coastal populations. Blood pressure is an important risk factor of hypertension and cardiovascular diseases. Given the extent of salinization of freshwater in many low-lying countries including in Bangladesh, and the likely exacerbation related to climate change-induced sea level rise, implementation of preventative strategies through dietary interventions along with promotion of low saline drinking water must be a priority in these settings. Copyright © 2016 Elsevier Ltd. All rights reserved.
Vascular effects of intravenous intralipid and dextrose infusions in obese subjects
Gosmanov, Aidar R.; Smiley, Dawn D.; Peng, Limin; Siquiera, Joselita; Robalino, Gonzalo; Newton, Christopher; Umpierrez, Guillermo E.
2013-01-01
Hyperglycemia and elevated free fatty acids (FFA) are implicated in the development of endothelial dysfunction. Infusion of soy-bean oil-based lipid emulsion (Intralipid®) increases FFA levels and results in elevation of blood pressure (BP) and endothelial dysfunction in obese healthy subjects. The effects of combined hyperglycemia and high FFA on BP, endothelial function and carbohydrate metabolism are not known. Twelve obese healthy subjects received four random, 8-h IV infusions of saline, Intralipid 40 mL/h, Dextrose 10% 40 mL/h, or combined Intralipid and dextrose. Plasma levels of FFA increased by 1.03±0.34 mmol/L (p=0.009) after Intralipid, but FFAs remained unchanged during saline, dextrose, and combined Intralipid and dextrose infusion. Plasma glucose and insulin concentrations significantly increased after dextrose and combined Intralipid and dextrose (all, p<0.05) and were not different from baseline during saline and lipid infusion. Intralipid increased systolic BP by 12±9 mmHg (p<0.001) and diastolic BP by 5±6 mmHg (p=0.022), and decreased flow-mediated dilatation (FMD) from baseline by 3.2%±1.4% (p<0.001). Saline and dextrose infusion had neutral effects on BP and FMD. The co-administration of lipid and dextrose decreased FMD by 2.4%±2.1% (p=0.002) from baseline, but did not significantly increase systolic or diastolic BP. Short-term Intralipid infusion significantly increased FFA and BP; in contrast, FFA and BP were unchanged during combined infusion of Intralipid and dextrose. Combined Intralipid and dextrose infusion resulted in endothelial dysfunction similar to Intralipid alone. PMID:22483976
Elevated CO2 stimulates marsh elevation gain, counterbalancing sea-level rise
Langley, J.A.; McKee, K.L.; Cahoon, D.R.; Cherry, J.A.; Megonigala, J.P.
2009-01-01
Tidal wetlands experiencing increased rates of sea-level rise (SLR) must increase rates of soil elevation gain to avoid permanent conversion to open water. The maximal rate of SLR that these ecosystems can tolerate depends partly on mineral sediment deposition, but the accumulation of organic matter is equally important for many wetlands. Plant productivity drives organic matter dynamics and is sensitive to global change factors, such as rising atmospheric CO2 concentration. It remains unknown how global change will influence organic mechanisms that determine future tidal wetland viability. Here, we present experimental evidence that plant response to elevated atmospheric [CO2] stimulates biogenic mechanisms of elevation gain in a brackish marsh. Elevated CO2 (ambient + 340 ppm) accelerated soil elevation gain by 3.9 mm yr−1in this 2-year field study, an effect mediated by stimulation of below-ground plant productivity. Further, a companion greenhouse experiment revealed that the CO2 effect was enhanced under salinity and flooding conditions likely to accompany future SLR. Our results indicate that by stimulating biogenic contributions to marsh elevation, increases in the greenhouse gas, CO2, may paradoxically aid some coastal wetlands in counterbalancing rising seas.
Elevated CO2 stimulates marsh elevation gain, counterbalancing sea-level rise.
Langley, J Adam; McKee, Karen L; Cahoon, Donald R; Cherry, Julia A; Megonigal, J Patrick
2009-04-14
Tidal wetlands experiencing increased rates of sea-level rise (SLR) must increase rates of soil elevation gain to avoid permanent conversion to open water. The maximal rate of SLR that these ecosystems can tolerate depends partly on mineral sediment deposition, but the accumulation of organic matter is equally important for many wetlands. Plant productivity drives organic matter dynamics and is sensitive to global change factors, such as rising atmospheric CO(2) concentration. It remains unknown how global change will influence organic mechanisms that determine future tidal wetland viability. Here, we present experimental evidence that plant response to elevated atmospheric [CO(2)] stimulates biogenic mechanisms of elevation gain in a brackish marsh. Elevated CO(2) (ambient + 340 ppm) accelerated soil elevation gain by 3.9 mm yr(-1) in this 2-year field study, an effect mediated by stimulation of below-ground plant productivity. Further, a companion greenhouse experiment revealed that the CO(2) effect was enhanced under salinity and flooding conditions likely to accompany future SLR. Our results indicate that by stimulating biogenic contributions to marsh elevation, increases in the greenhouse gas, CO(2), may paradoxically aid some coastal wetlands in counterbalancing rising seas.
Elevated CO2 stimulates marsh elevation gain, counterbalancing sea-level rise
Langley, J. Adam; McKee, Karen L.; Cahoon, Donald R.; Cherry, Julia A.; Megonigal, J. Patrick
2009-01-01
Tidal wetlands experiencing increased rates of sea-level rise (SLR) must increase rates of soil elevation gain to avoid permanent conversion to open water. The maximal rate of SLR that these ecosystems can tolerate depends partly on mineral sediment deposition, but the accumulation of organic matter is equally important for many wetlands. Plant productivity drives organic matter dynamics and is sensitive to global change factors, such as rising atmospheric CO2 concentration. It remains unknown how global change will influence organic mechanisms that determine future tidal wetland viability. Here, we present experimental evidence that plant response to elevated atmospheric [CO2] stimulates biogenic mechanisms of elevation gain in a brackish marsh. Elevated CO2 (ambient + 340 ppm) accelerated soil elevation gain by 3.9 mm yr−1 in this 2-year field study, an effect mediated by stimulation of below-ground plant productivity. Further, a companion greenhouse experiment revealed that the CO2 effect was enhanced under salinity and flooding conditions likely to accompany future SLR. Our results indicate that by stimulating biogenic contributions to marsh elevation, increases in the greenhouse gas, CO2, may paradoxically aid some coastal wetlands in counterbalancing rising seas. PMID:19325121
Nordlie, F.G.; Walsh, S.J.; Haney, D.C.; Nordlie, T.F.
1991-01-01
Routine metabolic rates were highest at ambient salinities from 15 to 50‰. Metabolism was somewhat lower at ambient salinities less than 15‰, and showed a sequential decline at ambient salinities greater than 50‰. It is suggested that routine metabolism is depressed at elevated salinities by reduced O, transfer, a consequence of maintenance of hydromineral balance in hypersaline waters.
Population-dependent effects of ocean acidification.
Wood, Hannah L; Sundell, Kristina; Almroth, Bethanie Carney; Sköld, Helén Nilsson; Eriksson, Susanne P
2016-04-13
Elevated carbon dioxide levels and the resultant ocean acidification (OA) are changing the abiotic conditions of the oceans at a greater rate than ever before and placing pressure on marine species. Understanding the response of marine fauna to this change is critical for understanding the effects of OA. Population-level variation in OA tolerance is highly relevant and important in the determination of ecosystem resilience and persistence, but has received little focus to date. In this study, whether OA has the same biological consequences in high-salinity-acclimated population versus a low-salinity-acclimated population of the same species was investigated in the marine isopod Idotea balthica.The populations were found to have physiologically different responses to OA. While survival rate was similar between the two study populations at a future CO2 level of 1000 ppm, and both populations showed increased oxidative stress, the metabolic rate and osmoregulatory activity differed significantly between the two populations. The results of this study demonstrate that the physiological response to OA of populations from different salinities can vary. Population-level variation and the environment provenance of individuals used in OA experiments should be taken into account for the evaluation and prediction of climate change effects. © 2016 The Author(s).
Population-dependent effects of ocean acidification
Wood, Hannah L.; Sundell, Kristina; Almroth, Bethanie Carney; Sköld, Helén Nilsson; Eriksson, Susanne P.
2016-01-01
Elevated carbon dioxide levels and the resultant ocean acidification (OA) are changing the abiotic conditions of the oceans at a greater rate than ever before and placing pressure on marine species. Understanding the response of marine fauna to this change is critical for understanding the effects of OA. Population-level variation in OA tolerance is highly relevant and important in the determination of ecosystem resilience and persistence, but has received little focus to date. In this study, whether OA has the same biological consequences in high-salinity-acclimated population versus a low-salinity-acclimated population of the same species was investigated in the marine isopod Idotea balthica. The populations were found to have physiologically different responses to OA. While survival rate was similar between the two study populations at a future CO2 level of 1000 ppm, and both populations showed increased oxidative stress, the metabolic rate and osmoregulatory activity differed significantly between the two populations. The results of this study demonstrate that the physiological response to OA of populations from different salinities can vary. Population-level variation and the environment provenance of individuals used in OA experiments should be taken into account for the evaluation and prediction of climate change effects. PMID:27053741
Estuarine fish are acclimated to living in an environment with rapid and frequent changes in temperature, salinity, pH, and dissolved oxygen (DO) levels; the physiology of these organisms is well suited to cope with extreme thermal, hypercapnic, and hypoxic stress. While the adve...
Zhao, Lei; Ye, Haihui; Cheng, Yongxu; Zeng, Chaoshu
2017-01-01
As a catadromous species, salinity is a key parameter that affects gonadal development of Chinese mitten crab Eriocheir sinensis during reproductive migration. It is however unclear the effects of salinity on the gonadal development of male E. sinensis as well as their physiological responses to salinity during reproductive migration. This study investigated the effects of four salinities (0 ‰, 6 ‰, 12 ‰ and 18 ‰) on gonadal development, osmoregulation and metabolism of adult male E. sinensis over a 40-day period. The results showed that elevating salinity promote gonadal development, increase hemolymph osmolality and K+ and Mg2+ concentrations (P < 0.05). The 12 ‰ salinity resulted in the highest contents of taurine and arginine in the hemolymph while the highest contents of threonine, phenylalanine, lysine, ß-alanine, tryptophan, ornithine and total free amino acids were found for 0 ‰ treatment (P < 0.05). A decreasing trend was detected for the Na+/K+-ATPase activity and its mRNA expression level in the posterior gills with salinity (P < 0.05). Total saturated fatty acids in the anterior gills decreased with increasing salinity (P < 0.05); the 0 ‰ treatment had the highest total polyunsaturated fatty acids in the posterior gills while total n-6 polyunsaturated fatty acids increased with salinity (P < 0.05). The hemolymph glucose and uric acid showed a decreasing trend as salinity while an increasing trend was found for the hemolymph triglyceride and high-density lipoprotein cholesterol (P < 0.05). The 12 ‰ treatment had the highest levels of hemolymph malonaldehyde and hepatopancreatic γ-glutamyltranspeptidase (P < 0.05). In conclusion, these results suggested that the brackish water promote gonadal development of male E. sinensis, and increase osmolality and ionic concentrations in hemolymph while reduced the activity of Na+ /K+- ATPase and its mRNA expression in the posterior gills as well as metabolism. PMID:28628611
Prazeres, Ana R; Carvalho, Fátima; Rivas, Javier; Patanita, Manuel; Dôres, Jóse
2013-10-01
The agricultural reuse of pretreated industrial wastewater resulting from cheese manufacture is shown as a suitable option for its disposal and management. This alternative presents attractive advantages from the economic and pollution control viewpoints. Pretreated cheese whey wastewater (CWW) has high contents of biodegradable organic matter, salinity and nutrients, which are essential development factors for plants with moderate to elevated salinity tolerance. Five different pretreated CWW treatments (1.75 to 10.02 dS m(-1)) have been applied in the tomato plant growth. Fresh water was used as a control run (average salinity level=1.44 dS m(-1)). Chemical characterization and indicator ratios of the leaves, stems and roots were monitored. The sodium and potassium leaf concentrations increased linearly with the salinity level in both cultivars, Roma and Rio Grande. Similar results were found in the stem sodium content. However, the toxic sodium accumulations in the cv. Roma exceeded the values obtained in the cv. Rio Grande. In this last situation, K and Ca uptake, absorption, transport and accumulation capacities were presented as tolerance mechanisms for the osmotic potential regulation of the tissues and for the ion neutralization. Consequently, Na/Ca and Na/K ratios presented lower values in the cv. Rio Grande. Na/Ca ratio increased linearly with the salinity level in leaves and stems, regardless of the cultivar. Regarding the Na/K ratio, the values demonstrated competition phenomena between the ions for the cv. Rio Grande. Despite the high chloride content of the CWW, no significant differences were observed for this nutrient in the leaves and stems. Thus, no nitrogen deficiency was demonstrated by the interaction NO3(-)/Cl(-). Nitrogen also contributes to maintain the water potential difference between the tissues and the soil. Na, P, Cl and N radicular concentrations were maximized for high salinity levels (≥2.22 dS m(-1)) of the pretreated CWW. © 2013 Elsevier B.V. All rights reserved.
Khalid, Muhammad; Bilal, Muhammad; Hassani, Danial; Iqbal, Hafiz M N; Wang, Hang; Huang, Danfeng
2017-12-01
Salinity is one of the increasingly serious environmental problems worldwide for cultivating agricultural crops. The present study was aimed to ascertain the potential of beneficial soil bacterium Azospirillum brasilense to alleviate saline stress in Trifolium repens. Experimental plants (white clover) were grown from seeds and inoculated with or without A. brasilense bacterial strain supplemented with 0, 40, 80, or 120 mM NaCl into soil. The growth attributes including, shoot heights, root lengths, fresh and dry weights, leaf area and chlorophyll content were significantly enhanced in T. repens plants grown in A. brasilense inoculated soil than un-inoculated controls, particularly under elevated salinity conditions (40, 80 and 120 mM NaCl). Malondialdehyde content of leaf was recorded to be declined under saline conditions. Moreover, the K + /Na + ratio was also improved in bacterium-inoculated plants, since A. brasilense significantly reduced the root and shoot Na + level under high salty environment. Results revealed that soil inoculation with A. brasilense could significantly promote T. repens growth under both non-saline and saline environments, and this study might be extended to other vegetables and crops for the germination and growth enhancement.
Ochsenkühn, Michael A.; Röthig, Till; D’Angelo, Cecilia; Wiedenmann, Jörg; Voolstra, Christian R.
2017-01-01
The endosymbiosis between Symbiodinium dinoflagellates and stony corals provides the foundation of coral reef ecosystems. The survival of these ecosystems is under threat at a global scale, and better knowledge is needed to conceive strategies for mitigating future reef loss. Environmental disturbance imposing temperature, salinity, and nutrient stress can lead to the loss of the Symbiodinium partner, causing so-called coral bleaching. Some of the most thermotolerant coral-Symbiodinium associations occur in the Persian/Arabian Gulf and the Red Sea, which also represent the most saline coral habitats. We studied whether Symbiodinium alter their metabolite content in response to high-salinity environments. We found that Symbiodinium cells exposed to high salinity produced high levels of the osmolyte 2-O-glycerol-α-d-galactopyranoside (floridoside), both in vitro and in their coral host animals, thereby increasing their capacity and, putatively, the capacity of the holobiont to cope with the effects of osmotic stress in extreme environments. Given that floridoside has been previously shown to also act as an antioxidant, this osmolyte may serve a dual function: first, to serve as a compatible organic osmolyte accumulated by Symbiodinium in response to elevated salinities and, second, to counter reactive oxygen species produced as a consequence of potential salinity and heat stress. PMID:28835914
Griffiths, Stephen R; Donato, David B; Lumsden, Linda F; Coulson, Graeme
2014-01-01
Wildlife and livestock that ingest bioavailable cyanide compounds in gold mining tailings dams are known to experience cyanide toxicosis. Elevated levels of salinity in open impoundments have been shown to prevent wildlife cyanide toxicosis by reducing drinking and foraging. This finding appears to be consistent for diurnal wildlife interacting with open impoundments, however the risks to nocturnal wildlife of cyanide exposure are unknown. We investigated the activity of insectivorous bats in the airspace above both fresh (potable to wildlife) and saline water bodies at two gold mines in the goldfields of Western Australian. During this study, cyanide-bearing solutions stored in open impoundments at both mine sites were hypersaline (range=57,000-295,000 mg/L total dissolved solids (TDS)), well above known physiological tolerance of any terrestrial vertebrate. Bats used the airspace above each water body monitored, but were more active at fresh than saline water bodies. In addition, considerably more terminal echolocation buzz calls were recorded in the airspace above fresh than saline water bodies at both mine sites. However, it was not possible to determine whether these buzz calls corresponded to foraging or drinking bouts. No drinking bouts were observed in 33 h of thermal video footage recorded at one hypersaline tailings dam, suggesting that this water is not used for drinking. There is no information on salinity tolerances of bats, but it could be assumed that bats would not tolerate salinity in drinking water at concentrations greater than those documented as toxic for saline-adapted terrestrial wildlife. Therefore, when managing wastewater impoundments at gold mines to avoid wildlife mortalities, adopting a precautionary principle, bats are unlikely to drink solutions at salinity levels ≥50,000 mg/L TDS. © 2013 Published by Elsevier Inc.
Chui, Apple Pui Yi; Ang, Put
2017-01-01
With projected changes in the marine environment under global climate change, the effects of single stressors on corals have been relatively well studied. However, more focus should be placed on the interactive effects of multiple stressors if their impacts upon corals are to be assessed more realistically. Elevation of sea surface temperature is projected under global climate change, and future increases in precipitation extremes related to the monsoon are also expected. Thus, the lowering of salinity could become a more common phenomenon and its impact on corals could be significant as extreme precipitation usually occurs during the coral spawning season. Here, we investigated the interactive effects of temperature [24, 27 (ambient), 30, 32°C] and salinity [33 psu (ambient), 30, 26, 22, 18, 14 psu] on larval settlement, post-settlement survival and early growth of the dominant coral Platygyra acuta from Hong Kong, a marginal environment for coral growth. The results indicate that elevated temperatures (+3°C and +5°C above ambient) did not have any significant effects on larval settlement success and post-settlement survival for up to 56 days of prolonged exposure. Such thermal tolerance was markedly higher than that reported in the literature for other coral species. Moreover, there was a positive effect of these elevated temperatures in reducing the negative effects of lowered salinity (26 psu) on settlement success. The enhanced settlement success brought about by elevated temperatures, together with the high post-settlement survival recorded up to 44 and 8 days of exposure under +3°C and +5°C ambient respectively, resulted in the overall positive effects of elevated temperatures on recruitment success. These results suggest that projected elevation in temperature over the next century should not pose any major problem for the recruitment success of P. acuta. The combined effects of higher temperatures and lowered salinity (26 psu) could even be beneficial. Therefore, corals that are currently present in marginal environments like Hong Kong, as exemplified by the dominant P. acuta, are likely to persist in a warmer and intermittently less saline, future ocean.
Chui, Apple Pui Yi; Ang, Put
2017-01-01
With projected changes in the marine environment under global climate change, the effects of single stressors on corals have been relatively well studied. However, more focus should be placed on the interactive effects of multiple stressors if their impacts upon corals are to be assessed more realistically. Elevation of sea surface temperature is projected under global climate change, and future increases in precipitation extremes related to the monsoon are also expected. Thus, the lowering of salinity could become a more common phenomenon and its impact on corals could be significant as extreme precipitation usually occurs during the coral spawning season. Here, we investigated the interactive effects of temperature [24, 27 (ambient), 30, 32°C] and salinity [33 psu (ambient), 30, 26, 22, 18, 14 psu] on larval settlement, post-settlement survival and early growth of the dominant coral Platygyra acuta from Hong Kong, a marginal environment for coral growth. The results indicate that elevated temperatures (+3°C and +5°C above ambient) did not have any significant effects on larval settlement success and post-settlement survival for up to 56 days of prolonged exposure. Such thermal tolerance was markedly higher than that reported in the literature for other coral species. Moreover, there was a positive effect of these elevated temperatures in reducing the negative effects of lowered salinity (26 psu) on settlement success. The enhanced settlement success brought about by elevated temperatures, together with the high post-settlement survival recorded up to 44 and 8 days of exposure under +3°C and +5°C ambient respectively, resulted in the overall positive effects of elevated temperatures on recruitment success. These results suggest that projected elevation in temperature over the next century should not pose any major problem for the recruitment success of P. acuta. The combined effects of higher temperatures and lowered salinity (26 psu) could even be beneficial. Therefore, corals that are currently present in marginal environments like Hong Kong, as exemplified by the dominant P. acuta, are likely to persist in a warmer and intermittently less saline, future ocean. PMID:28622371
Mccormick, S D; Regish, A M
2018-06-23
Human activity has resulted in increasing atmospheric carbon dioxide (CO 2 ), which will result in reduced pH and higher levels of CO 2 in the ocean, a process known as ocean acidification. Understanding the effects of ocean acidification (OA) on fishes will be important to predicting and mitigating its consequences. Anadromous species such as salmonids may be especially at risk because of their rapid movements between fresh water and seawater, which could minimize their ability to acclimate. In the present study, we examine the effect of future OA on the salinity tolerance and early seawater growth of Atlantic salmon Salmo salar smolts. Exposure to 61.81 Pa and 102.34 Pa CO 2 did not alter salinity tolerance but did result in slightly lower plasma chloride levels in smolts exposed to seawater compared with controls (39.59 Pa). Gill Na + -K + -ATPase activity, plasma cortisol, glucose and haematocrit after seawater exposure were not altered by elevated CO 2 . Growth rate in the first 2 weeks of seawater exposure was greater at 102.34 Pa CO 2 than under control conditions. This study of the effects of OA on S. salar during the transition from fresh water to seawater indicates that elevated CO 2 is not likely to affect osmoregulation negatively and may improve early growth in seawater. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
Puget Sound Dissolved Oxygen Modeling Study: Development of an Intermediate-Scale Hydrodynamic Model
DOE Office of Scientific and Technical Information (OSTI.GOV)
Yang, Zhaoqing; Khangaonkar, Tarang; Labiosa, Rochelle G.
2010-11-30
The Washington State Department of Ecology contracted with Pacific Northwest National Laboratory to develop an intermediate-scale hydrodynamic and water quality model to study dissolved oxygen and nutrient dynamics in Puget Sound and to help define potential Puget Sound-wide nutrient management strategies and decisions. Specifically, the project is expected to help determine 1) if current and potential future nitrogen loadings from point and non-point sources are significantly impairing water quality at a large scale and 2) what level of nutrient reductions are necessary to reduce or dominate human impacts to dissolved oxygen levels in the sensitive areas. In this study, anmore » intermediate-scale hydrodynamic model of Puget Sound was developed to simulate the hydrodynamics of Puget Sound and the Northwest Straits for the year 2006. The model was constructed using the unstructured Finite Volume Coastal Ocean Model. The overall model grid resolution within Puget Sound in its present configuration is about 880 m. The model was driven by tides, river inflows, and meteorological forcing (wind and net heat flux) and simulated tidal circulations, temperature, and salinity distributions in Puget Sound. The model was validated against observed data of water surface elevation, velocity, temperature, and salinity at various stations within the study domain. Model validation indicated that the model simulates tidal elevations and currents in Puget Sound well and reproduces the general patterns of the temperature and salinity distributions.« less
Acute acetaminophen toxicity in transgenic mice with elevated hepatic glutathione.
Rzucidlo, S J; Bounous, D I; Jones, D P; Brackett, B G
2000-06-01
Previous studies demonstrated that elevation of hepatic glutathione (GSH) concentrations protect against acetaminophen (APAP) hepatotoxicity in mice. Employing transgenic mice overexpressing glutathione synthetase, this study was conducted to determine if sustained elevation of hepatic GSH concentrations could ameliorate or prevent APAP toxicity. International Cancer Research transgenic mouse males and matched (ie same strain, sex, and age) control nontransgenic mice were pretreated ip with GSH synthetase substrate gamma-glutamylcysteinyl ethyl ester (gamma-GCE) or with saline. After a 16-h fast, mice received a single dose of 500 mg APAP/kg bw in saline ip and were sacrificed 4 h later. Other mice similarly pretreated were killed without APAP challenge. The elevated GSH concentrations in transgenic mice livers did not lessen APAP hepatotoxicity. Instead higher degrees of hepatotoxicity and nephrotoxicity were observed in transgenic mice than in controls as indicated by higher serum alanine aminotransferase activity and more severe histopathological lesions in transgenic mice livers and kidneys. Pretreatment with gamma-GCE did not affect either initial or post-APAP treatment tissue GSH concentrations or observed degrees of toxicity. Detection of a higher level of serum APAP in transgenic mice and the histopathological lesions found in transgenic mice kidneys together with no observable nephrotoxicity in control mice indicated early kidney damage in transgenic mice. Our findings suggest that high levels of GSH-APAP conjugates resulting from increased GSH concentrations in the livers of transgenic mice caused rapid kidney damage. Compromised excretory ability may have caused retention of APAP, which, in effect, elicited higher hepatotoxicity than that observed in nontransgenic mice.
Starbuck, E M; Fitts, D A
1998-12-01
Water intake was elevated in sodium-depleted rats during a daytime salt appetite test, but other rats drank a similar amount of water when saline was not available for drinking during the test. This water intake stimulated by sodium depletion was blocked by an inhibition of angiotensin (ANG) II synthesis with a high dose of captopril (100 mg/kg, sc). Captopril did not reduce water intake by causing hypotensive shock or uremia, because water and saline intakes were increased rather than decreased after a low dose of captopril (5 mg/kg) that also reduced blood pressure and elevated blood urea nitrogen. The water intake, but not salt appetite, induced by sodium depletion was greatly reduced by a lesion of the subfornical organ (SFO) in one-bottle tests, and this was not clearly related to any effects of the lesion on blood pressure. A physiological role for ANG II in water intake induced by sodium depletion has recently been disputed, but the simplest explanation for the data remains that elevated levels of circulating ANG II bind to receptors in the SFO to generate daytime water drinking during sodium depletion.
Implications of salinity pollution hotspots on agricultural production
NASA Astrophysics Data System (ADS)
Floerke, Martina; Fink, Julia; Malsy, Marcus; Voelker, Jeanette; Alcamo, Joseph
2016-04-01
Salinity pollution can have many negative impacts on water resources used for drinking, irrigation, and industrial purposes. Elevated concentrations of salinity in irrigation water can lead to decreased crop production or crop death and, thus, causing an economic problem. Overall, salinity pollution is a global problem but tends to be more severe in arid and semi-arid regions where the dilution capacity of rivers and lakes is lower and the use of irrigation higher. Particularly in these regions agricultural production is exposed to high salinity of irrigation water as insufficient water quality further reduces the available freshwater resources. According to the FAO, irrigated agriculture contributes about 40 percent of the total food production globally, and therefore, high salinity pollution poses a major concern for food production and food security. We use the WaterGAP3 modeling framework to simulate hydrological, water use, and water quality conditions on a global scale for the time period 1990 to 2010. The modeling framework is applied to simulate total dissolved solids (TDS) loadings and in-stream concentrations from different point and diffuse sources to get an insight on potential environmental impacts as well as risks to agricultural food production. The model was tested and calibrated against observed data from GEMStat and literature sources. Although global in scope, the focus of this study is on developing countries, i.e., in Africa, Asia, and Latin America, as these are most threatened by salinity pollution. Furthermore, insufficient water quality for irrigation and therefore restrictions in irrigation water use are examined, indicating limitations to crop production. Our results show that elevated salinity concentrations in surface waters mainly occur in peak irrigation regions as irrigated agriculture is not only the most relevant water use sector contributing to water abstractions, but also the dominant source of salinity pollution. Additionally, large metropolitan regions are initially loading hotspots and pollution, too, and prevention becomes important as point sources are dependent on sewer connection rates and treatment levels. In conclusion, this study provides a detailed picture of the spatial and temporal distribution of salinity pollution and identifies hotspot areas as well as the dominant sources. Furthermore, impacts of water quality degradation on agricultural production and food security are quantified, which aim for a better understanding of the risks for food security caused by water quality impairment.
Wulff, Angela; Karlberg, Maria; Olofsson, Malin; Torstensson, Anders; Riemann, Lasse; Steinhoff, Franciska S; Mohlin, Malin; Ekstrand, Nina; Chierici, Melissa
2018-01-01
Helcom scenario modelling suggests that the Baltic Sea, one of the largest brackish-water bodies in the world, could expect increased precipitation (decreased salinity) and increased concentration of atmospheric CO 2 over the next 100 years. These changes are expected to affect the microplanktonic food web, and thereby nutrient and carbon cycling, in a complex and possibly synergistic manner. In the Baltic Proper, the extensive summer blooms dominated by the filamentous cyanobacteria Aphanizomenon sp., Dolichospermum spp. and the toxic Nodularia spumigena contribute up to 30% of the yearly new nitrogen and carbon exported to the sediment. In a 12 days outdoor microcosm experiment, we tested the combined effects of decreased salinity (from 6 to 3) and elevated CO 2 concentrations (380 and 960 µatm) on a natural summer microplanktonic community, focusing on diazotrophic filamentous cyanobacteria. Elevated p CO 2 had no significant effects on the natural microplanktonic community except for higher biovolume of Dolichospermum spp. and lower biomass of heterotrophic bacteria. At the end of the experimental period, heterotrophic bacterial abundance was correlated to the biovolume of N. spumigena. Lower salinity significantly affected cyanobacteria together with biovolumes of dinoflagellates, diatoms, ciliates and heterotrophic bacteria, with higher biovolume of Dolichospermum spp. and lower biovolume of N. spumigena , dinoflagellates, diatoms, ciliates and heterotrophic bacteria in reduced salinity. Although the salinity effects on diatoms were apparent, they could not clearly be separated from the influence of inorganic nutrients. We found a clear diurnal cycle in photosynthetic activity and pH, but without significant treatment effects. The same diurnal pattern was also observed in situ ( p CO 2 , pH). Thus, considering the Baltic Proper, we do not expect any dramatic effects of increased p CO 2 in combination with decreased salinity on the microplanktonic food web. However, long-term effects of the experimental treatments need to be further studied, and indirect effects of the lower salinity treatments could not be ruled out. Our study adds one piece to the complicated puzzle to reveal the combined effects of increased p CO 2 and reduced salinity levels on the Baltic microplanktonic community.
Slowey, Aaron J.; Rytuba, James J.
2008-01-01
This report summarizes data obtained from field sampling of mine tailings and waste rock at the Rathburn and Petray Mines that was initiated in July 17, 2001 and water and sediment in regional springs and tributaries that drain from the mine area into Bear Creek on December 14, 2004 and February 16 and May 27, 2005. Although it was initially assumed that the mines were the cause of elevated levels of monomethyl Hg measured by the Central Regional Water Quality Control Board in tributaries near their confluence with Bear Creek (Foe and others, unpublished results), it became apparent during this study that ground water springs were also potential sources of Hg. In addition to sampling of springs in May 2005, saline ground water seepage along an unnamed fault on the west side of Bear Valley was sampled on December 13-14, 2006. We did not sample water or sediment in Bear Creek itself during this study. Our results permit a preliminary assessment of mining and natural sources of Hg and associated chemical constituents that could elevate levels of monomethyl Hg in Bear Creek.
Urea loading enhances freezing survival and postfreeze recovery in a terrestrially hibernating frog.
Costanzo, Jon P; Lee, Richard E
2008-09-01
We tested the hypothesis that urea, an osmolyte accumulated early in hibernation, functions as a cryoprotectant in the freeze-tolerant wood frog, Rana sylvatica. Relative to saline-treated, normouremic (10 micromol ml(-1)) frogs, individuals rendered hyperuremic (70 micromol ml(-1)) by administration of an aqueous urea solution exhibited significantly higher survival (100% versus 64%) following freezing at -4 degrees C, a potentially lethal temperature. Hyperuremic frogs also had lower plasma levels of intracellular proteins (lactate dehydrogenase, creatine kinase, hemoglobin), which presumably escaped from damaged cells, and more quickly recovered neurobehavioral functions following thawing. Experimental freezing-thawing did not alter tissue urea concentrations, but did elevate glucose levels in the blood and organs of all frogs. When measured 24 h after thawing commenced, glucose concentrations were markedly higher in urea-loaded frogs as compared to saline-treated ones, possibly because elevated urea retarded glucose clearance. Like other low-molecular-mass cryoprotectants, urea colligatively reduces both the amount of ice forming within the body and the osmotic dehydration of cells. In addition, by virtue of certain non-colligative properties, it may bestow additional protection from freeze-thaw damage not afforded by glucose.
The effect of competition on Bacopa monnieri zonation in an temporarily open/closed tropical estuary
NASA Astrophysics Data System (ADS)
Ribeiro, Jose Pedro N.; Tiberio, Fernanda C. S.; de Oliveira, Alexandre A.
2015-09-01
In this paper we investigated the role of competition to determine Bacopa monnieri L. Pennel (Plantaginaceae) zonation in a temporarily open/closed tropical estuary. In this estuary, B. monnieri occupies a given vertical zone in the saline stretch, where it forms dense monospecific stands, but is absent elsewhere. We transplanted turfs to areas outside of their natural occurrence in the estuary, both in the presence and absence of competition: a higher-elevation zone, a lower-elevation zone and a non-saline region. Turfs transplanted between naturally occurring stands served as controls. Turfs transplanted to the lower zone either died or became much smaller. As there was no competition under this condition, we conclude that the absence of this species from this zone is due to abiotic conditions, likely light limitation imposed by the turbid water column. Turfs transplanted to the higher zone under competition died; however, in the absence of competition, they survived. Turfs transplanted to the non-saline zone died, regardless of the presence or absence of competition, indicating an abiotic restraint. Our results indicate that the absence of B. monnieri from higher elevations is related to competitive displacement, whereas its absence from lower elevations and from non-saline areas is related to abiotic drivers.
NASA Astrophysics Data System (ADS)
Zhang, Dan; Guo, Xiantao; Wang, Fang; Dong, Shuanglin
2016-10-01
To determine the response of Litopenaeus vannamei to periodical salinity fluctuation, a 30-day experiment was conducted in laboratory. In this experiment, two salinity fluctuation amplitudes of 4 (group S4) and 10 (group S10) were designed. The constant salinity of 30 (group S0) was used as the control. Levels of shrimp growth, molting frequency (MF), cellular energy status (ATP, ADP and AMP), as well as the expression of genes encoding molt-inhibiting hormone (MIH), crustacean hyperglycemic hormone (CHH), ecdysteroid-regulated protein (ERP), and energy-related AMP-activated protein kinase (AMPK) were determined. The results showed that periodical salinity fluctuation significantly influenced all indicators except MF which ranged from 13.3% in group S10 to15.4% in group S4. In comparison with shrimps cultured at the constant salinity of 30, those in group S4 showed a significant elevation in growth rate, food conversion efficiency, cellular energy status, ERP and MIH gene transcript abundance, and a significant reduction in CHH and AMPK transcript abundance ( P < 0.05). However, salinity fluctuation of 10 only resulted in a significant variation in MIH and CHH gene expression when compared to the control ( P < 0.05). According to our findings, L. vannamei may be highly capable of tolerating salinity fluctuation. When ambient salinity fluctuated at approx. 4, the increased MF and energy stores in organisms may aid to promoting shrimp growth.
GABAergic control of neostriatal dopamine D2 receptor binding and behaviors in the rat.
Nikolaus, Susanne; Beu, Markus; de Souza Silva, Maria Angelica; Huston, Joseph P; Antke, Christina; Müller, Hans-Wilhelm; Hautzel, Hubertus
2017-02-01
The present study assessed the influence of the GABA A receptor agonist muscimol and the GABA A receptor antagonist bicuculline on neostriatal dopamine D 2 receptor binding in relation to motor and exploratory behaviors in the rat. D 2 receptor binding was measured in baseline and after challenge with either 1mg/kg muscimol or 1mg/kg bicuculline. In additional rats, D 2 receptor binding was measured after injection of saline. After treatment with muscimol, bicuculline and saline, motor and exploratory behaviors were assessed for 30min in an open field prior to administration of [ 123 I]S-3-iodo-N-(1-ethyl-2-pyrrolidinyl)methyl-2-hydroxy-6-methoxybenzamide ([ 123 I]IBZM). For baseline and challenges, striatal equilibrium ratios (V 3 ″) were computed as estimation of the binding potential. Muscimol but not bicuculline reduced D 2 receptor binding relative to baseline and to saline. Travelled distance, duration of rearing and frequency of rearing and of head-shoulder motility were lower after muscimol compared to saline. In contrast, duration of rearing and grooming and frequency of rearing, head-shoulder motility and grooming were elevated after bicuculline relative to saline. Moreover, bicuculline decreased duration of sitting and head-shoulder motility. The muscimol-induced decrease of motor/exploratory behaviors can be related to an elevation of striatal dopamine levels. In contrast, bicuculline is likely to elicit a decline of synaptic dopamine, which, however, is compensated by the time of D 2 receptor imaging studies. The results indicate direct GABAergic control over D 2 receptor binding in the neostriatum in relation to behavioral action, and, thus, complement earlier pharmacological studies. Copyright © 2016. Published by Elsevier Inc.
Gorcek, Zeynep; Erdal, Serkan
2015-11-01
Soil salinity is one of the most detrimental environmental factors affecting the growth of plants and limiting their agricultural productivity. This study investigated whether exogenous lipoic acid (LA) pretreatment plays a role in promoting salt tolerance in wheat seedlings. The seedlings were treated with LA (1.75 mmol L(-1)) and salt (100 mmol L(-1) NaCl) separately and a combination of them. Salt stress significantly reduced relative water content, leaf surface area, ribulose bisphosphate carboxylase expression, and chlorophyll content but increased the content of osmo-regulator protein, carbohydrates and proline. In addition, salinity led to an imbalance in the inorganic composition of wheat leaves. While it elevated Na(+) content compared to control, Ca content and K(+)/Na(+) ratio were reduced. Under saline conditions, despite increases in antioxidant enzyme activity and levels of antioxidant compounds (ascorbate and glutathione), the content of reactive oxygen species (superoxide anion, hydrogen peroxide) and malondialdehyde were higher than in control seedlings. LA significantly promoted osmo-regulator level and antioxidant enzyme activities compared to stressed seedlings alone. Also, it both increased levels of ascorbate and glutathione and regenerated their oxidised forms, thus contributing to maintaining cellular redox status. Similarly, LA prevented excessive accumulation of Na(+) and promoted K(+)/Na(+) ratio and Ca content. Reactive oxygen species content was significantly reduced, and the inhibitions in the above parameters markedly recovered. LA reduced salinity-induced oxidative damage and thus contributed to the growth and development of plants in saline soils by modulating ion homeostasis between plant and soil as well as in osmo-regulator content and antioxidant system. © 2014 Society of Chemical Industry.
Chang, Dwayne; Manecksha, Rustom P; Syrrakos, Konstantinos; Lawrentschuk, Nathan
2012-01-01
To investigate the effects of height, external pressure, and bladder fullness on the flow rate in continuous, non-continuous cystoscopy and the automated irrigation fluid pumping system (AIFPS). Each experiment had two 2-litre 0.9% saline bags connected to a continuous, non-continuous cystoscope or AIFPS via irrigation tubing. Other equipment included height-adjustable drip poles, uroflowmetry devices, and model bladders. In Experiment 1, saline bags were elevated to measure the increment in flow rate. In Experiment 2, saline bags were placed under external pressures to evaluate the effect on flow rate. In Experiment 3, flow rate changes in response to variable bladder fullness were measured. Elevating saline bags caused an increase in flow rates, however the increment slowed down beyond a height of 80 cm. Increase in external pressure on saline bags elevated flow rates, but inconsistently. A fuller bladder led to a decrease in flow rates. In all experiments, the AIFPS posted consistent flow rates. Traditional irrigation systems were susceptible to changes in height of irrigation solution, external pressure application, and bladder fullness thus creating inconsistent flow rates. The AIFPS produced consistent flow rates and was not affected by any of the factors investigated in the study.
The Effects of Elevated pCO2, Hypoxia and Temperature on ...
Estuarine fish are acclimated to living in an environment with rapid and frequent changes in temperature, salinity, pH, and dissolved oxygen (DO) levels; the physiology of these organisms is well suited to cope with extreme thermal, hypercapnic, and hypoxic stress. While the adverse effects of low dissolved oxygen levels on estuarine fish has been well-documented, the interaction between low DO and elevated pCO2 is not well understood. There is some evidence that low DO and elevated pCO2 interact antagonistically, however little information exists on how projected changes of pCO2 levels in near-shore waters may affect estuarine species, and how these changes may specifically interact with dissolved oxygen and temperature. We explored the survivability of 7-day post fertilization sheepshead minnow, Cyprinodon variegatus, using short term exposure to the combined effects of elevated pCO2 (~1300 µatm; IPCC RCP 8.5) and low dissolved oxygen levels (~2 mg/L). Additionally, we determined if the susceptibility of these fish to elevated pCO2 and low DO was influenced by increases in temperature from 27.5°C to 35°C. Results from this study and future studies will be used to identify estuarine species and lifestages sensitive to the combined effects of elevated pCO2 and low dissolved oxygen. This project was created in order to better understand the interactive effects of projected pCO2 levels and hypoxia in estuarine organisms. This work is currently focused on the se
Cardiopulmonary baroreceptor control of muscle sympathetic nerve activity in heat-stressed humans
NASA Technical Reports Server (NTRS)
Crandall, C. G.; Etzel, R. A.; Farr, D. B.
1999-01-01
Whole body heating decreases central venous pressure (CVP) while increasing muscle sympathetic nerve activity (MSNA). In normothermia, similar decreases in CVP elevate MSNA, presumably via cardiopulmonary baroreceptor unloading. The purpose of this project was to identify whether increases in MSNA during whole body heating could be attributed to cardiopulmonary baroreceptor unloading coincident with the thermal challenge. Seven subjects were exposed to whole body heating while sublingual temperature, skin blood flow, heart rate, arterial blood pressure, and MSNA were monitored. During the heat stress, 15 ml/kg warmed saline was infused intravenously over 7-10 min to increase CVP and load the cardiopulmonary baroreceptors. We reported previously that this amount of saline was sufficient to return CVP to pre-heat stress levels. Whole body heating increased MSNA from 25 +/- 3 to 39 +/- 3 bursts/min (P < 0. 05). Central blood volume expansion via rapid saline infusion did not significantly decrease MSNA (44 +/- 4 bursts/min, P > 0.05 relative to heat stress period) and did not alter mean arterial blood pressure (MAP) or pulse pressure. To identify whether arterial baroreceptor loading decreases MSNA during heat stress, in a separate protocol MAP was elevated via steady-state infusion of phenylephrine during whole body heating. Increasing MAP from 82 +/- 3 to 93 +/- 4 mmHg (P < 0.05) caused MSNA to decrease from 36 +/- 3 to 15 +/- 4 bursts/min (P < 0.05). These data suggest that cardiopulmonary baroreceptor unloading during passive heating is not the primary mechanism resulting in elevations in MSNA. Moreover, arterial baroreceptors remain capable of modulating MSNA during heat stress.
Blewett, Tamzin A; Wood, Chris M
2015-12-01
Nickel (Ni) is a metal of environmental concern, known to cause toxicity to freshwater organisms by impairing ionoregulation and/or respiratory gas exchange, and by inducing oxidative stress. However, little is known regarding how nickel toxicity is influenced by salinity. In the current study we investigated the salinity-dependence and mechanisms of sub-lethal Ni toxicity in a euryhaline crab (Carcinus maenas). Crabs were acclimated to three experimental salinities--20, 60 and 100% seawater (SW)--and exposed to 3mg/L Ni for 24h or 96 h. Tissues were dissected for analysis of Ni accumulation, gills were taken for oxidative stress analysis (catalase activity and protein carbonyl content), haemolymph ions were analysed for ionoregulatory disturbance, and oxygen consumption was determined in exercised crabs after 96 h of Ni exposure. Total Ni accumulation was strongly dependant on salinity, with crabs from 20% SW displaying the highest tissue Ni burdens after both 24 and 96-h exposures. After 96 h of exposure, the highest accumulation of Ni occurred in the posterior (ionoregulatory) gills at the lowest salinity, 20% SW. Posterior gill 8 exhibited elevated protein carbonyl levels and decreased catalase activity after Ni exposure, but only in 20% SW. Similarly, decreased levels of haemolymph Mg and K and an increased level of Ca were recorded but only in crabs exposed to Ni for 96 h in 20% SW. Oxygen consumption after exercise was also inhibited in crabs exposed to Ni in 20% SW. These data show for the first time the simultaneous presence of all three modes of sub-lethal Ni toxicity in exposed animals, and indicate a strong salinity dependence of sub-lethal Ni toxicity to the euryhaline crab, C. maenas, a pattern that corresponded to tissue Ni accumulation. Copyright © 2015 Elsevier Inc. All rights reserved.
Céspedes, V; Pallarés, S; Arribas, P; Millán, A; Velasco, J
2013-10-01
Water salinity and ionic composition are among the main environmental variables that constrain the fundamental niches of aquatic species, and accordingly, physiological tolerance to these factors constitutes a crucial part of the evolution, ecology, and biogeography of these organisms. The present study experimentally estimated the fundamental saline and anionic niches of adults of two pairs of congeneric saline beetle species that differ in habitat preference (lotic and lentic) in order to test the habitat constraint hypothesis. Osmotic and anionic realised niches were also estimated based on the field occurrences of adult beetle species using Outlying Mean Index analysis and their relationship with experimental tolerances. In the laboratory, all of the studied species showed a threshold response to increased salinity, displaying high survival times when exposed to low and intermediate conductivity levels. These results suggest that these species are not strictly halophilic, but that they are able to regulate both hyperosmotically and hypoosmotically. Anionic water composition had a significant effect on salinity tolerance at conductivity levels near their upper tolerance limits, with decreased species survival at elevated sulphate concentrations. Species occupying lentic habitats demonstrated higher salinity tolerance than their lotic congeners in agreement with the habitat constraint hypothesis. As expected, realised salinity niches were narrower than fundamental niches and corresponded to conditions near the upper tolerance limits of the species. These species are uncommon on freshwater-low conductivity habitats despite the fact that these conditions might be physiologically suitable for the adult life stage. Other factors, such as biotic interactions, could prevent their establishment at low salinities. Differences in the realised anionic niches of congeneric species could be partially explained by the varying habitat availability in the study area. Combining the experimental estimation of fundamental niches with realised field data niche estimates is a powerful method for understanding the main factors constraining species' distribution at multiple scales, which is a key issue when predicting species' ability to cope with global change. Copyright © 2013 Elsevier Ltd. All rights reserved.
Ko, Ginger W K; Dineshram, R; Campanati, Camilla; Chan, Vera B S; Havenhand, Jon; Thiyagarajan, Vengatesen
2014-09-02
Ocean acidification (OA) effects on larvae are partially attributed for the rapidly declining oyster production in the Pacific Northwest region of the United States. This OA effect is a serious concern in SE Asia, which produces >80% of the world's oysters. Because climate-related stressors rarely act alone, we need to consider OA effects on oysters in combination with warming and reduced salinity. Here, the interactive effects of these three climate-related stressors on the larval growth of the Pacific oyster, Crassostrea gigas, were examined. Larvae were cultured in combinations of temperature (24 and 30 °C), pH (8.1 and 7.4), and salinity (15 psu and 25 psu) for 58 days to the early juvenile stage. Decreased pH (pH 7.4), elevated temperature (30 °C), and reduced salinity (15 psu) significantly delayed pre- and post-settlement growth. Elevated temperature lowered the larval lipid index, a proxy for physiological quality, and negated the negative effects of decreased pH on attachment and metamorphosis only in a salinity of 25 psu. The negative effects of multiple stressors on larval metamorphosis were not due to reduced size or depleted lipid reserves at the time of metamorphosis. Our results supported the hypothesis that the C. gigas larvae are vulnerable to the interactions of OA with reduced salinity and warming in Yellow Sea coastal waters now and in the future.
Kulkarni, Malavika; Chuchendra, L. S.; Bhavya, P. J.
2018-01-01
Background: The onset time of neuromuscular blockade is a crucial time associated with the risk of hypoxia and pulmonary aspiration. Various strategies have been undertaken to shorten this onset time. Therefore, we investigated the effects of bolus of 20 ml saline followed by limb elevation after administration of rocuronium in a dose of 0.6 mg/kg to study the onset time. Methodology: Thirty patients were randomly allocated to the bolus saline group or control group. General anesthesia was induced and maintained with fentanyl and propofol. Rocuronium 0.6 mg/kg intravenous (IV) was administered followed by 20 ml saline bolus and limb elevation in the study group compared to administration of 0.6 mg/kg in a running drip only in the control. Onset of neuromuscular block was assessed by acceleromyography at the adductor pollicis muscle with train-of-four stimulation. Results: The lag time was shorter in bolus group (34 s median) than in control group (45 s median), P < 0.017. The onset time was shorter in bolus group (55 s median) than in control group (110 s median), P < 0.001. The T1 recovery to 25% was longer in bolus group (42 min median) than in control group (39 min median) which was statistically not significant. Conclusion: Rocuronium 0.6 mg/kg IV followed by bolus 20 ml saline and concomitant limb elevation resulted in shorter lag time, faster onset of neuromuscular blockade, good intubating conditions without prolonging clinical duration of action when compared to the control. PMID:29628555
Salinity-mediated cyanogenesis in white clover (Trifolium repens) affects trophic interactions
Ballhorn, Daniel J.; Elias, Jacob D.
2014-01-01
Background and Aims Increasing soil salinity poses a major plant stress in agro-ecosystems worldwide. Surprisingly little is known about the quantitative effect of elevated salinity on secondary metabolism in many agricultural crops. Such salt-mediated changes in defence-associated compounds may significantly alter the quality of food and forage plants as well as their resistance against pests. In the present study, the effects of soil salinity on cyanogenesis in white clover (Trifolium repens), a forage crop of international importance, are analysed. Methods Experimental clonal plants were exposed to five levels of soil salinity, and cyanogenic potential (HCNp, total amount of accumulated cyanide in a given plant tissue), β-glucosidase activity, soluble protein concentration and biomass production were quantified. The attractiveness of plant material grown under the different salt treatments was tested using cafeteria-style feeding trials with a generalist (grey garden slug, Deroceras reticulatum) and a specialist (clover leaf weevil, Hypera punctata) herbivore. Key Results Salt treatment resulted in an upregulation of HCNp, whereas β-glucosidase activity and soluble protein concentration showed no significant variation among treatments. Leaf area consumption of both herbivore species was negatively correlated with HCNp, indicating bottom-up effects of salinity-mediated changes in HCNp on plant consumers. Conclusions The results suggest that soil salinity leads to an upregulation of cyanogenesis in white clover, which results in enhanced resistance against two different natural herbivores. The potential implications for such salinity-mediated changes in plant defence for livestock grazing remain to be tested. PMID:25006176
Doyle, Thomas W.; Conner, William H.; Day, Richard H.; Krauss, Ken W.; Swarzenski, Christopher M.
2007-01-01
The frequency of hurricane landfall in a given coastal stretch may play a more important role in the ecology of coastal forests than previously thought because of direct and indirect impacts of fallen trees and the introduction of salt water that lingers long after the storm passes. Findings show that surge events can inundate interior freshwater forests many miles from the coast and elevate soil salinities twofold to threefold. These elevated salinities may contribute to delayed mortality of certain tree species and set the stage for eventual forest decline and dieback.
NASA Astrophysics Data System (ADS)
Windham-Myers, L.; Holmquist, J. R.; Woo, I.; Bergamaschi, B. A.; Byrd, K. B.; Crooks, S.; Drexler, J. Z.; Feagin, R. A.; Ferner, M. C.; Gonneea, M. E.; Kroeger, K. D.; Megonigal, P.; Morris, J. T.; Schile, L. M.; Simard, M.; Sutton-Grier, A.; Takekawa, J.; Troxler, T.; Weller, D.; Callaway, J.; Herold, N.
2016-12-01
In Year 2, the NASA Blue Carbon Monitoring Systems group leveraged USDA, USFWS and NOAA datasets, extensive field datasets, and targeted remote-sensing products to address basic questions regarding the size of carbon (C) stocks, and the directions and magnitudes of C fluxes in the US coastal zone since 1996. We review the uncertainty associated with 5 major terms in our Land Use-Land Cover Change (LULCC)-based accounting, both nationally and within sentinel sites (Cape Cod, Chesapeake Bay, Everglades, Louisiana, San Francisco Bay, Puget Sound). 1) To make distinctions between tidal and non-tidal wetlands we have relied on a combination of wetland and LiDAR-derived elevation maps. Existing products appear sufficient for saline wetlands, however many freshwater wetlands (1M ha) may be tidal despite current hydrologic mapcodes. 2) We are currently estimating methane emissions using salinity regime as a proxy. Methane emissions are variable across intermediate salinities, though not captured by the current binary classification of wetlands as either fresh or saline. 3) We are currently using a combination of USDA's SSURGO and independent core data to map soil C stocks. Soil C density varies little and is consistent across depth, salinity regime, and dominant plant cover type. 4) To model soil C fluxes, with C accumulating as sea level rises and C released with erosion or oxidation, we have applied IPCC default emission factors for the 2% of tidal wetland acreage lost to water (the dominant conversion), but have modeled C gain in wetlands-remaining-wetlands (98% of CONUS tidal wetlands) based on correlations between sea-level rise and sediment accretion, with the equation - Δ soil organic C stock = Δ elevation x soil C density. 5) To quantify biomass change through time, we developed a robust (R2 > 0.6) hybrid mapping approach including object-based image analysis, multispectral data, and RADAR. Overall, soil and biomass C stocks appear readily estimated and improved from Tier 1 default values. To further reduce uncertainty in the US GHG inventory for coastal wetlands, we propose efforts to confirm the extent of tidal inundation, develop default values for methane emissions associated with intermediate salinities, and model soil C accretion, the dominant "blue carbon" sink, across continental and local gradients.
Choi, Soonwook; Yu, Eunah; Kim, Duk-Soo; Sugimori, Mutsuyuki; Llinás, Rodolfo R
2015-01-01
We have examined the effects of RNS60, a 0.9% saline containing charge-stabilized oxygen nanobubble-based structures. RNS60 is generated by subjecting normal saline to Taylor–Couette–Poiseuille (TCP) flow under elevated oxygen pressure. This study, implemented in Xenopus laevis oocytes, addresses both the electrophysiological membrane properties and parallel biological processes in the cytoplasm. Intracellular recordings from defolliculated X. laevis oocytes were implemented in: (1) air oxygenated standard Ringer's solution, (2) RNS60-based Ringer's solution, (3) RNS10.3 (TCP-modified saline without excess oxygen)-based Ringer's, and (4) ONS60 (saline containing high pressure oxygen without TCP modification)-based Ringer's. RNS60-based Ringer's solution induced membrane hyperpolarization from the resting membrane potential. This effect was prevented by: (1) ouabain (a blocker of the sodium/potassium ATPase), (2) rotenone (a mitochondrial electron transfer chain inhibitor preventing usable ATP synthesis), and (3) oligomycin A (an inhibitor of ATP synthase) indicating that RNS60 effects intracellular ATP levels. Increased intracellular ATP levels following RNS60 treatment were directly demonstrated using luciferin/luciferase photon emission. These results indicate that RNS60 alters intrinsic the electrophysiological properties of the X. laevis oocyte membrane by increasing mitochondrial-based ATP synthesis. Ultrastructural analysis of the oocyte cytoplasm demonstrated increased mitochondrial length in the presence of RNS60-based Ringer's solution. It is concluded that the biological properties of RNS60 relate to its ability to optimize ATP synthesis. PMID:25742953
Ghelichpour, Melika; Taheri Mirghaed, Ali; Mirzargar, Seyed Saeed; Joshaghani, Hamidreza; Ebrahimzadeh Mousavi, Hoseinali
2018-01-01
To evaluate the effects of indoxacarb on saltwater stress response in Cyprinus carpio, the fish were pre-exposed to indoxacarb (0, 0.75, 1.5 and 3mg/L denoted as CP, 0.75IT, 1.5IT and 3IT, respectively) for 21 days and then released to saltwater. A negative control (CN) group was included (the fish were held in indoxacarb-free water for the entire experiment). The fish were sampled immediately (0h) and 24, 48 and 72h after the salinity exposure for the analysis of plasma cortisol, glucose and sodium, chloride, potassium and calcium levels. All fish pre-exposed to 3mg/L indoxacarb, died after the first day of salinity challenge. CP showed typical cortisol response after the salinity challenge, but, cortisol response of the fish pre-exposed to indoxacarb (0.75IT and 1.5IT) was blocked. Plasma glucose increased significantly in all groups compared to the CN; however, this elevation had no consistent trend in 0.75IT and 1.5IT which indicated interference in glucose response due to indoxacarb exposure. Plasma sodium increased (compared to CN) in all groups after the salinity challenge. However, elevation in plasma chloride and potassium was significantly different among the groups and the indoxacarb-treated fish showed slightly sooner ionic disturbance. The results clearly indicate that indoxacarb impairs stress response of C. carpio and the fish may not be able to respond normally to additional stressors, which threatens their survival. Copyright © 2017 Elsevier Inc. All rights reserved.
NASA Astrophysics Data System (ADS)
Lautz, L. K.; Hoke, G. D.; Lu, Z.; Siegel, D. I.
2013-12-01
Hydraulic fracturing has the potential to introduce saline water into the environment due to migration of deep formation water to shallow aquifers and/or discharge of flowback water to the environment during transport and disposal. It is challenging to definitively identify whether elevated salinity is associated with hydraulic fracturing, in part, due to the real possibility of other anthropogenic sources of salinity in the human-impacted watersheds in which drilling is taking place and some formation water present naturally in shallow groundwater aquifers. We combined new and published chemistry data for private drinking water wells sampled across five southern New York (NY) counties overlying the Marcellus Shale (Broome, Chemung, Chenango, Steuben, and Tioga). Measurements include Cl, Na, Br, I, Ca, Mg, Ba, SO4, and Sr. We compared this baseline groundwater quality data in NY, now under a moratorium on hydraulic fracturing, with published chemistry data for 6 different potential sources of elevated salinity in shallow groundwater, including Appalachian Basin formation water, road salt runoff, septic effluent, landfill leachate, animal waste, and water softeners. A multivariate random number generator was used to create a synthetic, low salinity (< 20 mg/L Cl) groundwater data set (n=1000) based on the statistical properties of the observed low salinity groundwater. The synthetic, low salinity groundwater was then artificially mixed with variable proportions of different potential sources of salinity to explore chemical differences between groundwater impacted by formation water, road salt runoff, septic effluent, landfill leachate, animal waste, and water softeners. We then trained a multivariate, discriminant analysis model on the resulting data set to classify observed high salinity groundwater (> 20 mg/L Cl) as being affected by formation water, road salt, septic effluent, landfill leachate, animal waste, or water softeners. Single elements or pairs of elements (e.g. Cl and Br) were not effective at discriminating between sources of salinity, indicating multivariate methods are needed. The discriminant analysis model classified most accurately samples affected by formation water and landfill leachate, whereas those contaminated by road salt, animal waste, and water softeners were more likely to be discriminated as contaminated by a different source. Using this approach, no shallow groundwater samples from NY appear to be affected by formation water, suggesting the source of salinity pre-hydraulic fracturing is primarily a combination of road salt, septic effluent, landfill leachate, and animal waste.
Connor, J A; Tseng, H Y; Hockberger, P E
1987-05-01
Digital imaging of the Ca indicator fura-2 has been used to study the responses of developing granule cells in culture to depolarization and transmitter action. Unstimulated cells bathed in Krebs saline exhibited cytoplasmic Ca ion concentrations, [Ca2+], that were generally in the 30-60 nM range. Exposure of cells to high-potassium (25 mM) saline depolarized the membrane potential and produced an immediate rise in [Ca2+] that recovered within 2-3 min in normal saline. The response grew progressively larger over the first 20 d in culture. Transient increases in [Ca2+] to levels greater than 1 microM were observed after 12-14 d in vitro, at which time the cells displayed intense electrical activity when exposed to high K. At this stage, the increases were attenuated by blocking action potential activity with TTX. In TTX-treated or immature cells, in which the transient phase of the Ca change was relatively small, a second exposure to high K typically produced a much larger Ca response that the initial exposure. The duration of this facilitation of the response persisted for periods longer than 5 min. Application of the neurotransmitter GABA induced a transient increase in membrane conductance, with a reversal potential near resting potential (approx. -60 mV), and caused an intracellular Ca2+ increase that outlasted the exposure to GABA by several minutes. Glutamate, or kainate, induced an increase in membrane conductance but with a reversal potential more positive than spike threshold. These agents also elevated intracellular Ca2+, but unlike the case with GABA, this Ca response reversed rapidly upon removal of the transmitter. The facilitatory effect of repeated exposures to high-K saline, as well as the persistent Ca elevation following a brief GABA application, suggests that granule cells possess the capability of displaying activity-dependent changes in Ca levels in culture.
Marshall, W.S.; Emberley, T.R.; Singer, T.D.; Bryson, S.E.; McCormick, S.D.
1999-01-01
Freshwater-adapted killifish (Fundulus heteroclitus) were transferred directly from soft fresh water to full-strength sea water for periods of 1h, 3h, 8h and 1, 2, 7, 14 and 30 days. Controls were transferred to fresh water for 24 h. Measured variables included: blood [Na+], osmolality, glucose and cortisol levels, basal and stimulated rates of ion transport and permeability of in vitro opercular epithelium, gill Na+/K+-ATPase and citrate synthase activity and chloride cell ultrastructure. These data were compared with previously published killifish cystic fibrosis transmembrane conductance regulator (kfCFTR) expression in the gills measured over a similar time course. Plasma cortisol levels peaked at 1 h, coincident with a rise in plasma [Na+]. At 8 h after transfer to sea water, a time at which previous work has shown kfCFTR expression to be elevated, blood osmolality and [Na+] were high, and cortisol levels and opercular membrane short-circuit current (I(SC); a measure of Cl- secretion rate) were low. The 24h group, which showed the highest level of kfCFTR expression, had the highest plasma [Na+] and osmolality, elevated plasma cortisol levels, significantly lower opercular membrane resistance, an increased opercular membrane ion secretion rate and collapsed tubule inclusions in mitochondria-rich cells, but no change in gill Na+/K+-ATPase and citrate synthase activity or plasma glucose levels. Apparently, killifish have a rapid (<1h) cortisol response to salinity coupled to subsequent (8-48 h) expression of kfCFTR anion channel proteins in existing mitochondria-rich cells that convert transport from ion uptake to ion secretion.
Baroreceptor unloading does not limit forearm sweat rate during severe passive heat stress.
Schlader, Zachary J; Gagnon, Daniel; Lucas, Rebekah A I; Pearson, James; Crandall, Craig G
2015-02-15
This study tested the hypothesis that sweat rate during passive heat stress is limited by baroreceptor unloading associated with heat stress. Two protocols were performed in which healthy subjects underwent passive heat stress that elicited an increase in intestinal temperature of ∼1.8°C. Upon attaining this level of hyperthermia, in protocol 1 (n = 10, 3 females) a bolus (19 ml/kg) of warm (∼38°C) isotonic saline was rapidly (5-10 min) infused intravenously to elevate central venous pressure (CVP), while in protocol 2 (n = 11, 5 females) phenylephrine was infused intravenously (60-120 μg/min) to return mean arterial pressure (MAP) to normothermic levels. In protocol 1, heat stress reduced CVP from 3.9 ± 1.9 mmHg (normothermia) to -0.6 ± 1.4 mmHg (P < 0.001), while saline infusion returned CVP to normothermic levels (5.1 ± 1.7 mmHg; P > 0.999). Sweat rate was elevated by heat stress (1.21 ± 0.44 mg·cm(-2)·min(-1)) but remained unchanged during rapid saline infusion (1.26 ± 0.47 mg·cm(-2)·min(-1), P = 0.5), whereas cutaneous vascular conductance increased from 77 ± 10 to 101 ± 20% of local heating max (P = 0.029). In protocol 2, MAP was reduced with heat stress from 85 ± 7 mmHg to 76 ± 8 mmHg (P = 0.048). Although phenylephrine infusion returned MAP to normothermic levels (88 ± 7 mmHg; P > 0.999), sweat rate remained unchanged during phenylephrine infusion (1.39 ± 0.22 vs. 1.41 ± 0.24 mg·cm(-2)·min(-1); P > 0.999). These data indicate that both cardiopulmonary and arterial baroreceptor unloading do not limit increases in sweat rate during passive heat stress. Copyright © 2015 the American Physiological Society.
Glial Reactivity in Resistance to Methamphetamine-Induced Neurotoxicity
Friend, Danielle M.; Keefe, Kristen A.
2013-01-01
Neurotoxic regimens of methamphetamine (METH) result in reactive microglia and astrocytes in striatum. Prior data indicate that rats with partial dopamine (DA) loss resulting from prior exposure to METH are resistant to further decreases in striatal DA when re-exposed to METH 30 days later. Such resistant animals also do not show an activated microglia phenotype, suggesting a relation between microglial activation and METH-induced neurotoxicity. To date, the astrocyte response in such resistance has not been examined. Thus, this study examined glial-fibrillary acidic protein (GFAP) and CD11b protein expression in striata of animals administered saline or a neurotoxic regimen of METH on postnatal days 60 and/or 90 (Saline:Saline, Saline:METH, METH:Saline, METH:METH). Consistent with previous work, animals experiencing acute toxicity (Saline:METH) showed both activated microglia and astocytes, whereas those resistant to the acute toxicity (METH:METH) did not show activated microglia. Interestingly, GFAP expression remained elevated in rats exposed to METH at PND60 (METH:Saline), and was not elevated further in resistant rats treated for the second time with METH (METH:METH). These data suggest that astrocytes remain reactive up to 30 days post-METH exposure. Additionally, these data indicate that astrocyte reactivity does not reflect acute, METH-induced DA terminal toxicity, whereas microglial reactivity does. PMID:23414433
Spencer, J.E.; Pearthree, P.A.; House, P.K.
2008-01-01
The upper Miocene to lower Pliocene Bouse Formation in the lower Colorado River trough of the American Southwest was deposited in three basins - from north to south, the Mohave, Havasu, and Blythe Basins - that were formed by extensional fault ing in the early to middle Miocene. Fossils of marine, brackish, and freshwater organ isms in the Bouse Formation have been interpreted to indicate an estuarine environment associated with early opening of the nearby Gulf of California. Regional uplift since 5 Ma is required to position the estuarine Bouse Formation at present elevations as high as 555 m, where greater uplift is required in the north. We present a compilation of Bouse Formation elevations that is consistent with Bouse deposition in lakes, with an abrupt 225 m northward increase in maximum Bouse elevations at Topock gorge north of Lake Havasu. Within Blythe and Havasu Basins, maximum Bouse elevations are 330 m above sea level in three widely spaced areas and reveal no evidence of regional tilting. To the north in Mohave Basin, numerous Bouse outcrops above 480 m elevation include three widely spaced sites where the Bouse Formation is exposed at 536-555 m. Numerical simulations of initial Colorado River inflow to a sequence of closed basins along the lower Colorado River corridor model a history of lake filling, spilling, evaporation and salt concentration, and outflow-channel incision. The simulations support the plausibility of evaporative concentration of Colorado River water to seawater-level salinities in Blythe Basin and indicate that such salinities could have remained stable for as long as 20-30 k.y. We infer that fossil marine organ isms in the Bouse Formation, restricted to the southern (Blythe) basin, reflect coloniza tion of a salty lake by a small number of species that were transported by birds.
Marsh collapse thresholds for coastal Louisiana estimated using elevation and vegetation index data
Couvillion, Brady R.; Beck, Holly
2013-01-01
Forecasting marsh collapse in coastal Louisiana as a result of changes in sea-level rise, subsidence, and accretion deficits necessitates an understanding of thresholds beyond which inundation stress impedes marsh survival. The variability in thresholds at which different marsh types cease to occur (i.e., marsh collapse) is not well understood. We utilized remotely sensed imagery, field data, and elevation data to help gain insight into the relationships between vegetation health and inundation. A Normalized Difference Vegetation Index (NDVI) dataset was calculated using remotely sensed data at peak biomass (August) and used as a proxy for vegetation health and productivity. Statistics were calculated for NDVI values by marsh type for intermediate, brackish, and saline marsh in coastal Louisiana. Marsh-type specific NDVI values of 1.5 and 2 standard deviations below the mean were used as upper and lower limits to identify conditions indicative of collapse. As marshes seldom occur beyond these values, they are believed to represent a range within which marsh collapse is likely to occur. Inundation depth was selected as the primary candidate for evaluation of marsh collapse thresholds. Elevation relative to mean water level (MWL) was calculated by subtracting MWL from an elevation dataset compiled from multiple data types including light detection and ranging (lidar) and bathymetry. A polynomial cubic regression was used to examine a random subset of pixels to determine the relationship between elevation (relative to MWL) and NDVI. The marsh collapse uncertainty range values were found by locating the intercept of the regression line with the 1.5 and 2 standard deviations below the mean NDVI value for each marsh type. Results indicate marsh collapse uncertainty ranges of 30.7–35.8 cm below MWL for intermediate marsh, 20–25.6 cm below MWL for brackish marsh, and 16.9–23.5 cm below MWL for saline marsh. These values are thought to represent the ranges of inundation depths within which marsh collapse is probable.
Resveratrol prevents insulin resistance caused by short-term elevation of free fatty acids in vivo.
Pereira, Sandra; Park, Edward; Moore, Jessy; Faubert, Brandon; Breen, Danna M; Oprescu, Andrei I; Nahle, Ashraf; Kwan, Denise; Giacca, Adria; Tsiani, Evangelia
2015-11-01
Elevated levels of plasma free fatty acids (FFA), which are commonly found in obesity, induce insulin resistance. FFA activate protein kinases including the proinflammatory IκBα kinase β (IKKβ), leading to serine phosphorylation of insulin receptor substrate 1 (IRS-1) and impaired insulin signaling. To test whether resveratrol, a polyphenol found in red wine, prevents FFA-induced insulin resistance, we used a hyperinsulinemic-euglycemic clamp with a tracer to assess hepatic and peripheral insulin sensitivity in overnight-fasted Wistar rats infused for 7 h with saline, Intralipid plus 20 U·mL(-1) heparin (IH; triglyceride emulsion that elevates FFA levels in vivo; 5.5 μL·min(-1)) with or without resveratrol (3 mg·kg(-1)·h(-1)), or resveratrol alone. Infusion of IH significantly decreased glucose infusion rate (GIR; P < 0.05) and peripheral glucose utilization (P < 0.05) and increased endogenous glucose production (EGP; P < 0.05) during the clamp compared with saline infusion. Resveratrol co-infusion, however, completely prevented the effects induced by IH infusion: it prevented the decreases in GIR (P < 0.05 vs. IH), peripheral glucose utilization (P < 0.05 vs. IH), and insulin-induced suppression of EGP (P < 0.05 vs. IH). Resveratrol alone had no effect. Furthermore, IH infusion increased serine (307) phosphorylation of IRS-1 in soleus muscle (∼30-fold, P < 0.001), decreased total IRS-1 levels, and decreased IκBα content, consistent with activation of IKKβ. Importantly, all of these effects were abolished by resveratrol (P < 0.05 vs. IH). These results suggest that resveratrol prevents FFA-induced hepatic and peripheral insulin resistance and, therefore, may help mitigate the health consequences of obesity.
Ahmad, Javed; Bashir, Humayra; Bagheri, Rita; Baig, Affan; Al-Huqail, Asma; Ibrahim, Mohamed M; Qureshi, M Irfan
2017-01-01
Parthenium hysterophorus is a plant that tolerates drought and salinity to an extremely high degree. Higher expression of stress-responsive proteome contributes for greater defence against abiotic stresses. Thus, P. hysterophorus could be a rich source of genes that encode stress-imparting mechanisms and systems. The present study utilizes comparative physiological and proteomic approaches for identification of key proteins involved in stress-defence of P. hysterophorus. Thirty-days-old plants were exposed to drought (10% PEG 6000) and salinity (160 mM NaCl) for 10 days duration. Both stresses induced oxidative stress estimated in terms of TBARS and H2O2. Levels of both enzymatic and non-enzymatic antioxidants were elevated, more by drought than salinity. Particularly, SOD, GR, CAT and GST proved to be assisting as very commendable defence under drought, as well as salinity. Levels of ascorbate, glutathione and proline were also increased by both stresses, more in response to drought. Comparative proteomics analysis revealed a significant change in relative abundance of 72 proteins under drought and salinity. Drought and salinity increased abundance of 45 and 41 proteins and decreased abundance of 24 and 26 proteins, respectively. Drought and salinity increased and decreased abundance of 31 and 18 proteins, respectively. The functions of identified proteins included those related to defence response (26%), signal transduction (13%), transcription and translation (10%), growth and development (8.5%), photosynthesis (8.5%), metabolism (7%), terpenoid biosynthesis (5.5%), protein modification and transport (7%), oxido-reductase (4%) and Miscellaneous (11%). Among the defence related proteins, antioxidants and HSPs constituted 26% and 21%, respectively. Present study suggests a potential role of defence proteins. Proteins involved in molecular stabilization, formation of osmolytes and wax and contributing to stress-avoiding anatomical features emerged as key and complex mechanisms for imparting stress tolerance to P. hysterophorus.
Ahmad, Javed; Bashir, Humayra; Bagheri, Rita; Baig, Affan; Al-Huqail, Asma; Ibrahim, Mohamed M.
2017-01-01
Parthenium hysterophorus is a plant that tolerates drought and salinity to an extremely high degree. Higher expression of stress-responsive proteome contributes for greater defence against abiotic stresses. Thus, P. hysterophorus could be a rich source of genes that encode stress-imparting mechanisms and systems. The present study utilizes comparative physiological and proteomic approaches for identification of key proteins involved in stress-defence of P. hysterophorus. Thirty-days-old plants were exposed to drought (10% PEG 6000) and salinity (160 mM NaCl) for 10 days duration. Both stresses induced oxidative stress estimated in terms of TBARS and H2O2. Levels of both enzymatic and non-enzymatic antioxidants were elevated, more by drought than salinity. Particularly, SOD, GR, CAT and GST proved to be assisting as very commendable defence under drought, as well as salinity. Levels of ascorbate, glutathione and proline were also increased by both stresses, more in response to drought. Comparative proteomics analysis revealed a significant change in relative abundance of 72 proteins under drought and salinity. Drought and salinity increased abundance of 45 and 41 proteins and decreased abundance of 24 and 26 proteins, respectively. Drought and salinity increased and decreased abundance of 31 and 18 proteins, respectively. The functions of identified proteins included those related to defence response (26%), signal transduction (13%), transcription and translation (10%), growth and development (8.5%), photosynthesis (8.5%), metabolism (7%), terpenoid biosynthesis (5.5%), protein modification and transport (7%), oxido-reductase (4%) and Miscellaneous (11%). Among the defence related proteins, antioxidants and HSPs constituted 26% and 21%, respectively. Present study suggests a potential role of defence proteins. Proteins involved in molecular stabilization, formation of osmolytes and wax and contributing to stress-avoiding anatomical features emerged as key and complex mechanisms for imparting stress tolerance to P. hysterophorus. PMID:28953916
Triki Fourati, Hela; Bouaziz, Moncef; Benzina, Mourad; Bouaziz, Samir
2017-04-01
Traditional surveying methods of soil properties over landscapes are dramatically cost and time-consuming. Thus, remote sensing is a proper choice for monitoring environmental problem. This research aims to study the effect of environmental factors on soil salinity and to map the spatial distribution of this salinity over the southern east part of Tunisia by means of remote sensing and geostatistical techniques. For this purpose, we used Advanced Spaceborne Thermal Emission and Reflection Radiometer data to depict geomorphological parameters: elevation, slope, plan curvature (PLC), profile curvature (PRC), and aspect. Pearson correlation between these parameters and soil electrical conductivity (EC soil ) showed that mainly slope and elevation affect the concentration of salt in soil. Moreover, spectral analysis illustrated the high potential of short-wave infrared (SWIR) bands to identify saline soils. To map soil salinity in southern Tunisia, ordinary kriging (OK), minimum distance (MD) classification, and simple regression (SR) were used. The findings showed that ordinary kriging technique provides the most reliable performances to identify and classify saline soils over the study area with a root mean square error of 1.83 and mean error of 0.018.
Lack of effect of naloxone on prolactin and seizures in electroconvulsive therapy.
Sperling, M R; Melmed, S; McAllister, T; Price, T R
1989-01-01
Both opiate agonist and antagonist injection have been reported to modulate prolactin secretion, alter brain excitability and produce seizures, and modify the postictal state. We studied the effects of administration of high-dose naloxone, an opiate antagonist, on postictal prolactin levels, seizure duration, and postictal behavior, using patients undergoing electroconvulsive therapy (ECT) as a seizure model. Seven patients had 8 mg naloxone injected prior to one ECT treatment and saline injected prior to another treatment, with the order of injection randomized. Before ECT and 15 min after ECT, prolactin levels were drawn, and no blunting of the expected postictal prolactin elevation by naloxone injection was observed. We found no evidence that endogenous opiates trigger prolactin secretion during seizures. Seizure duration was also similar in saline and naloxone groups, and naloxone did not reverse postictal depression, as has been reported in an animal model.
Ordoñez, Omar F; Lanzarotti, Esteban; Kurth, Daniel; Gorriti, Marta F; Revale, Santiago; Cortez, Néstor; Vazquez, Martin P; Farías, María E; Turjanski, Adrian G
2013-07-25
Exiguobacterium sp. strain S17 is a moderately halotolerant, arsenic-resistant bacterium that was isolated from Laguna Socompa stromatolites in the Argentinian Puna. The draft genome sequence suggests potent enzyme candidates that are essential for survival under multiple environmental extreme conditions, such as high levels of UV radiation, elevated salinity, and the presence of critical arsenic concentrations.
Valzachi, Maria Cristina; Teodorov, Elizabeth; Marcourakis, Tania; Bailey, Alexis; Camarini, Rosana
2013-01-01
Adolescence has been linked to greater risk-taking and novelty-seeking behavior and a higher prevalence of drug abuse and risk of relapse. Decreases in cyclic adenosine monophosphate response element binding protein (CREB) and phosphorylated CREB (pCREB) have been reported after repeated cocaine administration in animal models. We compared the behavioral effects of cocaine and abstinence in adolescent and adult mice and investigated possible age-related differences in CREB and pCREB levels. Adolescent and adult male Swiss mice received one daily injection of saline or cocaine (10 mg/kg, i.p.) for 8 days. On day 9, the mice received a saline injection to evaluate possible environmental conditioning. After 9 days of withdrawal, the mice were tested in the elevated plus maze to evaluate anxiety-like behavior. Twelve days after the last saline/cocaine injection, the mice received a challenge injection of either cocaine or saline, and locomotor activity was assessed. One hour after the last injection, the brains were extracted, and CREB and pCREB levels were evaluated using Western blot in the prefrontal cortex (PFC) and hippocampus. The cocaine-pretreated mice during adolescence exhibited a greater magnitude of the expression of behavioral sensitization and greater cocaine withdrawal-induced anxiety-like behavior compared with the control group. Significant increases in CREB levels in the PFC and hippocampus and pCREB in the hippocampus were observed in cocaine-abstinent animals compared with the animals treated with cocaine in adulthood. Interestingly, significant negative correlations were observed between cocaine sensitization and CREB levels in both regions. These results suggest that the behavioral and neurochemical consequences of psychoactive substances in a still-developing nervous system can be more severe than in an already mature nervous system. PMID:24205196
2013-01-01
Background Salinity inhibits growth and development of most plants. The response to salinity is complex and varies between plant organs and stages of development. It involves challenges of ion toxicities and deficiencies as well as osmotic and oxidative stresses. The range of functions affected by the stress is reflected in elaborate changes to the transcriptome. The mechanisms involved in the developmental-stage specificity of the inhibitory responses are not fully understood. The present study took advantage of the well characterized developmental progression that exists along the maize leaf, for identification of salinity induced, developmentally-associated changes to the transcriptome. Differential subtraction screening was conducted for cells of two developmental stages: from the center of the growth zone where the expansion rate is highest, and from older cells at a more distal location of the growing zone where the expansion rate is lower and the salinity restrictive effects are more pronounced. Real-Time PCR analysis was used for validation of the expression of selected genes. Results The salinity-induced changes demonstrated an age-related response of the growing tissue, with elevation of salinity-damages with increased age. Growth reduction, similar to the elevation of percentage dry matter (%DM), and Na and Cl concentrations were more pronounced in the older cells. The differential subtraction screening identified genes encoding to proteins involved in antioxidant defense, electron transfer and energy, structural proteins, transcription factors and photosynthesis proteins. Of special interest is the higher induced expression of genes involved in antioxidant protection in the young compared to older cells, which was accompanied by suppressed levels of reactive oxygen species (H2O2 and O2-). This was coupled with heightened expression in the older cells of genes that enhance cell-wall rigidity, which points at reduced potential for cell expansion. Conclusions The results demonstrate a cell-age specificity in the salinity response of growing cells, and point at involvement of the antioxidative response in cell growth restriction. Processes involved in reactive oxygen species (ROS) scavenging are more pronounced in the young cells, while the higher growth sensitivity of older cells is suggested to involve effects on cell-wall rigidity and lower protein protection. PMID:23324477
Ben-Shahar, Osnat; Keeley, Patrick; Cook, Mariana; Brake, Wayne; Joyce, Megan; Nyffeler, Myriel; Heston, Rebecca; Ettenberg, Aaron
2007-01-01
We previously reported that brief (1 hr), but not extended (6 hrs), daily access to cocaine results in a sensitized locomotor response to cocaine and in elevated c-Fos immunoreactivity and DAT binding in the nucleus accumbens (N.Acc) core. In order to better our understanding of the neural adaptations mediating the transition from controlled drug-use to addiction, the current experiments were set to further explore the neural adaptations resulting from these two access conditions. Rats received either brief daily access to saline or cocaine, or brief daily access followed by extended daily access, to cocaine. Subjects were then sacrificed either 20 minutes, or 14 or 60 days, after the last self-administration session. Samples of the ventral tegmental area (VTA), N.Acc core and shell, dorsal striatum, and medial prefrontal cortex (mPFC) were taken for analysis of D1 ([3H]SCH-23390), D2 ([3H]Spiperone), and NMDA ([3H]MK-801) receptor binding (using the method of receptor autoradiography). At 20 minutes into withdrawal D2 receptors were elevated and NMDA receptors were reduced in the mPFC of the brief access animals while D1 receptors were elevated in the N.Acc shell of the extended access animals, compared to saline controls. D2 receptors were reduced in the N.Acc shell of the brief access animals compared to saline controls after 14 days, and compared to extended access animals after 60 days of withdrawal. In summary, extended access to cocaine resulted in only transient changes in D1 receptors binding. These results suggest that the development of compulsive drug use is largely unrelated to changes in total binding of D2 or NMDA receptors. PMID:17161392
Circulating YKL-40‡ levels during human endotoxaemia
Johansen, J S; Krabbe, K S; Møller, K; Pedersen, B K
2005-01-01
YKL-40 is secreted by macrophages and neutrophils and patients with bacterial infections have elevated circulating YKL-40. The aim was to evaluate changes in plasma YKL-40 (determined by enzyme-linked immunosorbent assay (ELISA) at 0, 2, 4, 8, 24 and 32 h) in eight healthy volunteers after injection with Esherichia coli endotoxin or saline. Plasma YKL-40 increased after endotoxin injection from 31 µg/l (range 19–39 µg/l) to a maximum of 159 µg/l (61–552 µg/l, P < 0·01) at 24 h. The finding that plasma YKL-40 increased after endotoxin injection compared with saline (P < 0·001) suggests that YKL-40 has a functional role in infections. PMID:15807860
Middleton, Beth A.
2016-01-01
Hurricane wind and surge may have different influences on the subsequent composition of forests. During Hurricane Sandy, while damaging winds were highest near landfall in New Jersey, inundation occurred along the entire eastern seaboard from Georgia to Maine. In this study, a comparison of damage from salinity intrusion vs. wind/surge was recorded in swamps of the Delmarva Peninsula along the Pocomoke (MD) and Nanticoke (DE) Rivers, south of the most intense wind damage. Hickory Point Cypress Swamp (Hickory) was closest to the Chesapeake Bay and may have been subjected to a salinity surge as evidenced by elevated salinity levels at a gage upstream of this swamp (storm salinity = 13.1 ppt at Nassawango Creek, Snow Hill, Maryland). After Hurricane Sandy, 8% of the standing trees died at Hickory including Acer rubrum, Amelanchier laevis, Ilex spp., and Taxodium distichum. In Plot 2 of Hickory, 25% of the standing trees were dead, and soil salinity levels were the highest recorded in the study. The most important variables related to structural tree damage were soil salinity and proximity to the Atlantic coast as based on Stepwise Regression and NMDS procedures. Wind damage was mostly restricted to broken branches although tipped−up trees were found at Hickory, Whiton and Porter (species: Liquidamabar styraciflua, Pinus taeda, Populus deltoides, Quercus pagoda and Ilex spp.). These trees fell mostly in an east or east−southeast direction (88o−107o) in keeping with the wind direction of Hurricane Sandy on the Delmarva Peninsula. Coastal restoration and management can be informed by the specific differences in hurricane damage to vegetation by salt versus wind.
De-icing salt contamination reduces urban tree performance in structural soil cells.
Ordóñez-Barona, Camilo; Sabetski, Vadim; Millward, Andrew A; Steenberg, James
2018-03-01
Salts used for de-icing roads and sidewalks in northern climates can have a significant impact on water quality and vegetation. Sub-surface engineering systems, such as structural soil cells, can regulate water runoff and pollutants, and provide the necessary soil volume and irrigation to grow trees. However, the ability of such systems to manage de-icing salt contamination, and the impact of this contamination on the trees growing in them, have not been evaluated. We report on an field investigation of de-icing salt contamination in structural cells in two street-revitalization projects in Toronto, Canada, and the impact of this contamination on tree performance. We analyzed soil chemistry and collected tree attributes; these data were examined together to understand the effect of salinity on tree mortality rates and foliar condition. Data collected from continuous soil salinity loggers from April to June for one of the two sites were used to determine whether there was a long-term accumulation of salts in the soils. Results for both sites indicate that both sites displayed high salinity and alkalinity, with levels elevated beyond those suggested before those reported to cause negative tree effects. For one site, trees that were alive and trees that had a better foliar condition had significantly lower levels of soil salinity and alkalinity than other trees. High salinity and alkalinity in the soil were also associated with lower nutrient levels for both sites. Although tests for salinity accumulation in the soils of one site were negative, a longer monitoring of the soil conditions within the soil cells is warranted. Despite structural cells being increasingly utilized for their dual role in storm-water management and tree establishment, there may be a considerable trade-off between storm-water management and urban-forest function in northern climates where de-icing salt application continues to be commonplace. Copyright © 2017 Elsevier Ltd. All rights reserved.
Ganju, Neil K.; Dickhudt, Patrick J.; Montgomery, Ellyn T.; Brennand, Patrick; Derby, R. Kyle; Brooks, Thomas W.; Guntenspergen, Glenn R.; Martini, Marinna A.; Borden, Jonathan; Baldwin, Sandra M.
2012-01-01
Suspended-sediment transport is a critical element governing the geomorphology of tidal marshes. Marshes rely on both organic material and inorganic sediment deposition to maintain their elevation relative to sea level. In wetlands near the Blackwater National Wildlife Refuge, Maryland, portions of the salt marsh have been subsiding relative to sea level since the early 20th century. Other portions of the marsh have been successful at maintaining elevation. The U.S. Geological Survey performed observational deployments to measure suspended-sediment concentration in the tidal channels in order to understand the magnitude of suspended-sediment concentrations, the sediment-transport mechanisms, and differences between two marsh areas, one that subsided and one that maintained elevation. We deployed optical turbidity sensors and acoustic velocity meters at multiple sites over two periods in 2011. This report presents the time-series of oceanographic data collected during those field studies, including velocity, depth, turbidity, salinity, water temperature, and pH.
NASA Astrophysics Data System (ADS)
Comeaux, Rebecca S.; Allison, Mead A.; Bianchi, Thomas S.
2012-01-01
Black mangroves ( Avicennia spp.) are hypothesized to expand their latitudinal range with global climate change in the 21st century, induced by a reduction in the frequency and severity of coastal freezes, which are known to limit mangrove colony extent and individual tree size. The Gulf of Mexico is a prime candidate for population expansion to occur because it is located at the northward limit of black mangrove habitat. This may come at the expense of existing coastal saline wetlands that are dominantly Spartina spp. marsh grasses. The present study was conducted to focus on the implications of a marsh to mangrove transition in Gulf wetlands, specifically: (1) wetland resistance to accelerating eustatic sea level rise (ESLR) rates; (2) resistance to wave attack in large storms (increased cyclonic storm frequency/intensity is predicted with future climate warming); and (3) organic carbon sequestration and wetland soil geochemistry. Field sites of adjacent and inter-grown Avicennia germinans mangrove and Spartina marsh populations in similar geomorphological setting were selected in back-barrier areas near Port Aransas and Galveston, TX. Elevation surveys in the more mature Port Aransas site indicate mangrove vegetated areas are 4 cm higher in elevation than surrounding marsh on an average regional scale, and 1-2 cm higher at the individual mangrove scale. 210Pb and 137Cs accumulation rates and loss on ignition data indicate that mineral trapping is 4.1 times higher and sediment organics are 1.7 times lower in mangroves at Port Aransas. This additional mineral trapping does not differ in grain size character from marsh accumulation. Elevation change may also be effected by soil displacement of higher root volumes in mangrove cores. Port Aransas porosities are lower in mangrove rooted horizons, with a corresponding increase in sediment strength, suggesting mangrove intervals are more resistant to wave-induced erosion during storm events. Port Aransas mangroves exhibit higher pore water redox potentials and salinities over entire core depths and depressed pH over rooted intervals, suggesting a distinct diagenetic environment exists relative to marsh sites. The rooting network, which introduces oxygen into the sediment and focuses evapo-transpiration and salt exclusion within this zone, may prove advantageous when competing with grasses by elevating salinities to levels that are toxic for Spartina. Trends observed in the more mature systems of Port Aransas are generally absent in Galveston, suggesting the youth and physically shorter stature of these systems means they have not yet established a unique sediment signature.
Hurricane Rita surge data, southwestern Louisiana and southeastern Texas, September to November 2005
McGee, Benton D.; Goree, Burl B.; Tollett, Roland W.; Woodward, Brenda K.; Kress, Wade H.
2006-01-01
Pressure transducers and high-water marks were used to document the inland water levels related to storm surge generated by Hurricane Rita in southwestern Louisiana and southeastern Texas. On September 22-23, 2005, an experimental monitoring network consisting of 47 pressure transducers (sensors) was deployed at 33 sites over an area of about 4,000 square miles to record the timing, extent, and magnitude of inland hurricane storm surge and coastal flooding. Sensors were programmed to record date and time, temperature, and barometric or water pressure. Water pressure was corrected for changes in barometric pressure and salinity. Elevation surveys using global-positioning systems and differential levels were used to relate all storm-surge water-level data, reference marks, benchmarks, sensor measuring points, and high-water marks to the North American Vertical Datum of 1988 (NAVD 88). The resulting data indicated that storm-surge water levels over 14 feet above NAVD 88 occurred at three locations and rates of water-level rise greater than 5 feet per hour occurred at three locations near the Louisiana coast. Quality-assurance measures were used to assess the variability and accuracy of the water-level data recorded by the sensors. Water-level data from sensors were similar to data from co-located sensors, permanent U.S. Geological Survey streamgages, and water-surface elevations performed by field staff. Water-level data from sensors at selected locations were compared to corresponding high-water mark elevations. In general, the water-level data from sensors were similar to elevations of high quality high-water marks, while reporting consistently higher than elevations of lesser quality high-water marks.
Drought-induced recharge promotes long-term storage of porewater salinity beneath a prairie wetland
NASA Astrophysics Data System (ADS)
Levy, Zeno F.; Rosenberry, Donald O.; Moucha, Robert; Mushet, David M.; Goldhaber, Martin B.; LaBaugh, James W.; Fiorentino, Anthony J.; Siegel, Donald I.
2018-02-01
Subsurface storage of sulfate salts allows closed-basin wetlands in the semiarid Prairie Pothole Region (PPR) of North America to maintain moderate surface water salinity (total dissolved solids [TDS] from 1 to 10 g L-1), which provides critical habitat for communities of aquatic biota. However, it is unclear how the salinity of wetland ponds will respond to a recent shift in mid-continental climate to wetter conditions. To understand better the mechanisms that control surface-subsurface salinity exchanges during regional dry-wet climate cycles, we made a detailed geoelectrical study of a closed-basin prairie wetland (P1 in the Cottonwood Lake Study Area, North Dakota) that is currently experiencing record wet conditions. We found saline lenses of sulfate-rich porewater (TDS > 10 g L-1) contained in fine-grained wetland sediments 2-4 m beneath the bathymetric low of the wetland and within the currently ponded area along the shoreline of a prior pond stand (c. 1983). During the most recent drought (1988-1993), the wetland switched from a groundwater discharge to recharge function, allowing salts dissolved in surface runoff to move into wetland sediments beneath the bathymetric low of the basin. However, groundwater levels during this time did not decline to the elevation of the saline lenses, suggesting these features formed during more extended paleo-droughts and are stable in the subsurface on at least centennial timescales. We hypothesize a "drought-induced recharge" mechanism that allows wetland ponds to maintain moderate salinity under semiarid climate. Discharge of drought-derived saline groundwater has the potential to increase the salinity of wetland ponds during wet climate.
Kresse, Timothy M.; Clark, Brian R.
2008-01-01
Water-quality data from approximately 2,500 sites were used to investigate the distribution of chloride concentrations in the Mississippi River Valley alluvial aquifer in southeastern Arkansas. The large volume and areal distribution of the data used for the investigation proved useful in delineating areas of elevated (greater than 100 milligrams per liter) chloride concentrations, assessing potential sources of saline water, and evaluating trends in chloride distribution and concentration over time. Irrigation water containing elevated chloride concentrations is associated with negative effects to rice and soybeans, two of the major crops in Arkansas, and a groundwater chloride concentration of 100 milligrams per liter is recommended as the upper limit for use on rice. As such, accurately delineating areas with high salinity ground water, defining potential sources of chloride, and documenting trends over time is important in assisting the agricultural community in water management. The distribution and range of chloride concentrations in the study area revealed distinct areas of elevated chloride concentrations. Area I includes an elongated, generally northwest-southeast trending band of moderately elevated chloride concentrations in the northern part of the study area. This band of elevated chloride concentrations is approximately 40 miles in length and varies from approximately 2 to 9 miles in width, with a maximum chloride concentration of 360 milligrams per liter. Area II is a narrow, north-south trending band of elevated chloride concentrations in the southern part of the study area, with a maximum chloride concentration of 1,639 milligrams per liter. A zone of chloride concentrations exceeding 200 milligrams per liter is approximately 25 miles in length and 5 to 6 miles in width. In Area I, low chloride concentrations in samples from wells completed in the alluvial aquifer next to the Arkansas River and in samples from the upper Claiborne aquifer, which underlies the alluvial aquifer, indicate that leakage from the river and upward flow of saline water in underlying aquifers are not likely sources for the saline water in the alluvial aquifer in Area I. A good comparison was noted for chloride concentrations in Area I and surface geomorphology. In the majority of cases, elevated chloride concentrations occurred in backswamp deposits, with low concentrations (less than 50 milligrams per liter) in areas of active or abandoned channel deposits. The fine-grained, clay-rich deposits associated with backswamp areas likely restrict recharge, induce increased ratios between evapotranspiration and recharge, and experience minimal flushing of salts concentrated during evapotranspiration. In Area II, chloride isoconcentration maps of the underlying upper Claiborne aquifer, in addition to samples from wells completed in the middle and lower Claiborne aquifers, showed a similar chloride distribution to that of the alluvial aquifer with decreasing chloride concentrations to the east of the zone of elevated chloride concentrations, which suggests a deeper source of saline water that affects Tertiary and Quaternary aquifer systems. Mixing curves developed from bromide/chloride ratios in water samples from the alluvial aquifer, Tertiary aquifers, and samples of brine water from the Jurrasic Smackover Formation additionally discounted upward flow of saline water from underlying Tertiary formations as a potential mechanism for salinity in the alluvial aquifer in Area II. A review of information on oil exploration wells in Chicot County revealed that most of these wells were drilled from 1960 to 1980, after the elevated chloride concentrations were detected in the early 1950s. The elongated nature of the zone of elevated chloride concentrations in Area II suggests a line source or linear conduit connection with the source. Maps of a fractured limestone in the Smackover Formation in Arkansas, Mississippi, and Louisiana for purpose
Feyen, Bart F E; Coenen, Dries; Jorens, Philippe G; Wouters, Kristien; Maas, Andrew I R; Van Hoof, Viviane; Verbrugghe, Walter
2013-02-01
Thiopental is a cornerstone in the treatment of refractory status epilepticus and intractable intracranial hypertension. In our center we observed that thiopental might cause falsely elevated serum sodium levels. Triggered by a recent case experience of extremely elevated serum sodium levels during thiopental treatment, we retrospectively identified 53 patients treated with thiopental in our intensive care unit between 2007 and 2011 and evaluated electrolyte changes. We differentiated the analysis before and after introduction of a new device for sodium assays (Dimension Vista, Siemens) in the central laboratory in April 2010. Standardized in vitro laboratory tests were performed to study the effect of thiopental on sodium analysis. Before April 2010, serum sodium levels determined in the central laboratory showed a good agreement with the bedside point-of-care (POC) device during thiopental therapy with [sodium](laboratory) - [sodium](POC) of only 1.08 mmol/L (P = .0517). After April 2010, a strong discrepancy between laboratory values and POC values was observed with [sodium](laboratory) - [sodium](POC) = 11.57 mmol/L (P < .0001). Standardized in vitro testing confirmed that thiopental induced a dose-dependent false hypernatremia (P = .002). Thiopental treatment can result in falsely elevated serum sodium. This is a critical finding since high sodium levels preclude administrating mannitol or hypertonic saline for the treatment of elevated intracranial pressure. Moreover, a false high sodium level might lead to the inappropriate administration of hypotonic fluids potentially resulting in increased brain edema and even higher intracranial pressure. To our knowledge, this is the first paper describing this clinically relevant phenomenon.
Bull, Eleanor J; Porkess, Veronica; Rigby, Michael; Hutson, Peter H; Fone, Kevin C F
2006-03-01
The current study examined the long-term effect of brief exposure to 3,4-methylenedioxymethamphetamine (MDMA) on local cerebral glucose utilization (LCGU) in specific brain regions immediately following administration of the 5-HT2A/2C receptor agonist, 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI). Wistar rats (post-natal day (PND) 28, n = 24) were administered MDMA (5 mg/kg, i.p.) or saline (1 ml/kg, i.p.) four times daily for 2 consecutive days and core body temperature was recorded. Fifty-five days later and 10 min following injection of DOI (1 mg/kg, i.p.) or saline, LCGU was measured using the [14C]2-deoxyglucose (2-DG) technique. In the 4 hours following the initial injection (PND 28), MDMA-treated rats exhibited significant hyperthermia compared with saline-treated controls (p < 0.05-0.01). Eight weeks later, immediately following DOI challenge, LCGU was significantly elevated (an increase of 47%, p < 0.05) in the nucleus accumbens of MDMA/DOI pretreated rats, compared with that in MDMA/saline pre-treated controls. A similar trend was observed in other areas such as the lateral habenula, somatosensory cortex and hippocampal regions (percentage changes of 27-41%), but these did not reach significance. Blood glucose levels were significantly elevated in both groups of DOI-treated rats (p < 0.05-0.01). Thus, brief exposure of young rats to an MDMA regimen previously shown to cause anxiety-like behaviour and modest serotonergic neurotoxicity (Bull et al., 2004) increased DOI-induced energy metabolism in the nucleus accumbens and tended to increase metabolism in other brain regions, including the hippocampus, consistent with the induction of long-term brain region specific changes in synaptic plasticity.
Effects of milrinone on left ventricular cardiac function during cooling in an intact animal model.
Tveita, Torkjel; Sieck, Gary C
2012-08-01
Due to adverse effects of β-receptor agonists reported when applied during hypothermia, left ventricular (LV) cardiac effects of milrinone, a PDE3 inhibitor which mode of action is deprived the sarcolemmal β-receptor-G protein-PKA system, was tested during cooling to 15 °C. Sprague Dawley rats were instrumented to measure left ventricular (LV) pressure-volume changes using a Millar pressure-volume conductance catheter. Core temperature was reduced from 37 to 15 °C (60 min) using internal and external heat exchangers. Milrinone, or saline placebo, was given as continuous i.v. infusions for 30 min at 37 °C and during cooling. In normothermic controls continuous milrinone infusion for 90 min elevated cardiac output (CO) and stroke volume (SV) significantly. Significant differences in cardiac functional variables between the milrinone group and the saline control group during cooling to 15 °C were found: Compared to saline treated animals throughout cooling from 33 to 15 °CSV was significantly elevated in milrinone animals, the index of LV isovolumic relaxation, Tau, was significantly better preserved, and both HR and CO were significantly higher from 33 to 24 °C. Likewise, during cooling between 33 and 28 °C also LVdP/dt(max) was significantly higher in the milrinone group. Milrinone preserved LV systolic and diastolic function at a significantly higher level than in saline controls during cooling to 15 °C. In essential contrast to our previous results when using β-receptor agonists during hypothermia, the present experiment demonstrates the positive inotropic effects of milrinone on LV cardiac function during cooling to 15 °C. Copyright © 2012 Elsevier Inc. All rights reserved.
NASA Astrophysics Data System (ADS)
Cartwright, Ian; Weaver, Tamie R.; Simmons, Craig T.; Fifield, L. Keith; Lawrence, Charles R.; Chisari, Robert; Varley, Simon
2010-01-01
SummaryA low-salinity (total dissolved solids, TDS, <5000 mg/L) groundwater lens underlies the Murray River in the Colignan-Nyah region of northern Victoria, Australia. Hydraulic heads, surface water elevations, δ 18O values, major ion geochemistry, 14C activities, and 3H concentrations show that the lens is recharged from the Murray River largely through the riverbank with limited recharge through the floodplain. Recharge of the lens occurs mainly at high river levels and the low-salinity groundwater forms baseflow to some river reaches during times of low river levels. Within the lens, flow through the shallow Channel Sands and deeper Parilla Sands aquifers is sub-horizontal. While the Blanchetown Clay locally separates the Channel Sands and the Parilla Sands, the occurrence of recently recharged low-salinity groundwater below the Blanchetown Clay suggests that there is considerable leakage through this unit, implying that it is not an efficient aquitard. The lateral margin of the lens with the regional groundwater (TDS >25,000 mg/L) is marked by a hectometer to kilometer scale transition in TDS concentrations that is not stratigraphically controlled. Rather this boundary represents a mixing zone with the regional groundwater, the position of which is controlled by the rate of recharge from the river. The lens is part of an active and dynamic hydrogeological system that responds over years to decades to changes in river levels. The lens has shrunk during the drought of the late 1990s to the mid 2000s, and it will continue to shrink unless regular high flows in the Murray River are re-established. Over longer timescales, the rise of the regional water table due to land clearing will increase the hydraulic gradient between the regional groundwater and the groundwater in the lens, which will also cause it to degrade. Replacement of low-salinity groundwater in the lens with saline groundwater will ultimately increase the salinity of the Murray River reducing its utility for water supply and impacting riverine ecosystems.
Kincheloe, Karen L.; Stehn, Robert A.
1991-01-01
Tundra vegetation and environmental variables were sampled on the Yukon–Kuskokwim delta in western Alaska. On transects extending from intertidal mudflat to upland tundra, we estimated cover by vascular plant species, soil moisture, salinity, relative elevation, depth to permafrost, and distance upriver from the coast. Two-way indicator species analysis (TWINSPAN) classified 21 communities. Ordination by detrended correspondence analysis (DECORANA) revealed a gradient correlated with the combination of elevation, permafrost depth, and salinity along the first axis for both upriver and downriver transects.
Abdel Gader, Abdel Galil M.; Al Momen, Abdul Karim M.; Alhaider, Abdulqader; Brooks, Marjory B.; Catalfamo, James L.; Al Haidary, Ahmed A.; Hussain, Mansour F.
2013-01-01
The objective of this study was to characterize the highly elevated levels of clotting factor VIII (FVIII) in camel plasma. Whole blood was collected from healthy camels and factor VIII clotting activity (FVIII:C) assays were conducted using both the clotting and the chromogenic techniques. The anticoagulant citrate phosphate dextrose adenine (CPDA) produced the highest harvest of FVIII:C, the level of plasma factor VIII, compared to heparin:saline and heparin:CPDA anticoagulants. Camel FVIII can be concentrated 2 to 3 times in cryoprecipitate. There was a significant loss of camel FVIII when comparing levels of FVIII in camel plasma after 1 h of incubation at 37°C (533%), 40°C (364%), and 50°C (223%). Thrombin generation of camel plasma is comparable to that of human plasma. It was concluded that camel plasma contains very elevated levels of FVIII:C, approaching 8 times the levels in human plasma, and that these elevated levels could not be attributed to excessive thrombin generation. Unlike human FVIII:C, camel FVIII:C is remarkably heat stable. Taken together, these unique features of camel FVIII could be part of the physiological adaptation of hemostasis of the Arabian camel in order to survive in the hot desert environment. PMID:24082408
The Predictability of Near-Coastal Currents Using a Baroclinic Unstructured Grid Model
2011-12-28
clinic simulations. ADCIRC solves the time-dependent scalar transport equation for salinity and temperature. Through the equation of state...described by McDougall ct al. (2003), ADCIRC uses the temperature, salinity , and pressure in determining the density field. In order to avoid spurious...model. 2.3 Initialization and boundary forcing Temperature, salinity , elevation, and velocity fields from a regional ocean model are needed both to
Osmotherapy for intracranial hypertension: mannitol versus hypertonic saline.
Fink, Matthew E
2012-06-01
Hyperosmolar therapy is one of the core medical treatments for brain edema and intracranial hypertension, but controversy exists regarding the use of the most common agents, mannitol, and hypertonic saline. This article describes the relative merits and adverse effects of these agents using the best available clinical evidence. Mannitol is effective and has been used for decades in the treatment of traumatic brain injury, but it may precipitate acute renal failure if serum osmolarity exceeds 320 mOsm/L. Hypertonic saline appears to be safe, and serum sodium has been elevated to as high as 180 mEq/L in clinical settings without significant neurologic, cardiac, or renal injury. In small comparative trials both agents are effective and no clinically significant difference has been noted, but a properly powered trial has not yet been performed. Both mannitol and hypertonic saline are effective and have an acceptable risk profile for use in the treatment of elevated intracranial pressure secondary to brain edema.
Reproductive Hormones Modify Reception of Species-Typical Communication Signals in a Female Anuran
Lynch, Kathleen S.; Wilczynski, Walter
2008-01-01
In many vertebrates, the production and reception of species-typical courtship signals occurs when gonadotropin and gonadal hormone levels are elevated. These hormones may modify sensory processing in the signal receiver in a way that enhances behavioral responses to the signal. We examined this possibility in female túngara frogs (Physalaemus pustulosus) by treating them with either gonadotropin (which elevated estradiol) or saline and exposing them to either mate choruses or silence. Expression of an activity-dependent gene, egr-1, was quantified within two sub-nuclei of the auditory midbrain to investigate whether gonadotropin plus chorus exposure induced greater egr-1 induction than either of these stimuli alone. The laminar nucleus (LN), a sub-nucleus of the torus semicircularis that contains steroid receptors, exhibited elevated egr-1 induction in response to chorus exposure and gonadotropin treatment. Further analysis revealed that neither chorus exposure nor gonadotropin treatment alone elevated egr-1 expression in comparison to baseline levels whereas gonadotropin + chorus exposure did. This suggests that mate signals and hormones together produce an additive effect so that together they induce more egr-1 expression than either alone. Our previously published studies of female túngara frogs reveal that (1) gonadotropin-induced estradiol elevations also increase behavioral responses to male signals, and (2) reception of male signals elevates estradiol levels in the female. Here, we report data that reveal a novel mechanism by which males exploit female sensory processing to increase behavioral responses to their courtship signals. PMID:18032889
Dessu, Shimelis B; Price, René M; Troxler, Tiffany G; Kominoski, John S
2018-04-01
Since the 1880s, hydrological modification of the Greater Florida Everglades has reduced water levels and flows in Everglades National Park (ENP). The Comprehensive Everglades Restoration Program (CERP) began in 2000 to restore pre-drainage flows and preserve the natural landscape of the Everglades. However, sea-level rise (SLR) was not considered in the development of CERP. We used long-term data (2001-2016) from the Florida Coastal Everglades-Long Term Ecological Research Program to quantify and model the spatial dynamics of water levels, salinity, and nutrients in response to changes in climate, freshwater management and SLR in the Shark River Slough (SRS), ENP. Results indicate that fresh-to-marine head difference (FMHD) was the single most important factor affecting marine-to-freshwater hydrologic connectivity and transport of salinity and phosphorous upstream from the Gulf of Mexico. Sea-level has increasingly exceeded ground surface elevation at the most downstream freshwater site in SRS, thereby reducing the FMHD. We showed a higher impact of SLR in the dry season when there was practically no freshwater inflow to raise FMHD. We also demonstrated effectiveness of inflow depends more on the monthly distribution than the total annual volume. Hence, the impact per unit volume of inflow is significantly higher in the dry season in preventing high salinity and marine-derived nutrient levels. We advocate that FMHD needs to be factored into water management decisions to reduce adverse and likely irreversible effects of SLR throughout the Everglades landscape. Published by Elsevier Ltd.
Mangrove sedimentation and response to relative sea-level rise
Woodroffe, CD; Rogers, K.; Mckee, Karen L.; Lovelock, CE; Mendelssohn, IA; Saintilan, N.
2016-01-01
Mangroves occur on upper intertidal shorelines in the tropics and subtropics. Complex hydrodynamic and salinity conditions influence mangrove distributions, primarily related to elevation and hydroperiod; this review considers how these adjust through time. Accumulation rates of allochthonous and autochthonous sediment, both inorganic and organic, vary between and within different settings. Abundant terrigenous sediment can form dynamic mudbanks; tides redistribute sediment, contrasting with mangrove peat in sediment-starved carbonate settings. Sediments underlying mangroves sequester carbon, but also contain paleoenvironmental records of adjustments to past sea-level changes. Radiometric dating indicates long-term sedimentation, whereas Surface Elevation Table-Marker Horizon measurements (SET-MH) provide shorter perspectives, indicating shallow subsurface processes of root growth and substrate autocompaction. Many tropical deltas also experience deep subsidence, which augments relative sea-level rise. The persistence of mangroves implies an ability to cope with moderately high rates of relative sea-level rise. However, many human pressures threaten mangroves, resulting in continuing decline in their extent throughout the tropics.
Creatin-kinase elevation after accidental ingestion of almotriptan in an 18-month-old girl.
Castagno, E; Lupica, M; Viola, S; Savino, F; Miniero, R
2014-02-01
Few studies have been published to demonstrate tolerability and efficacy of almotriptan in adolescents and children with migraine, particularly in the first years of life, though preliminary results are favorable. We report the case of an 18-month-old infant with elevation of serum levels of creatin-kinase after the accidental ingestion of almotriptan. A previously healthy 18-month-old girl (weight: 13 kg) was admitted to our Department four hours after the accidental ingestion of 6.25 mg of almotriptan (0.48 mg/kg), without any specific symptom. The performed investigations showed high serum levels of creatin-kinase (CK) (527 IU/L; normal values: 24-170 IU/L). Transaminase, creatinine, aldolase, myoglobin and troponin T serum levels were normal. The electrocardiogram proved negative. Initial management consisted of parenteral rehydration with saline solution. CK levels lowered significantly at 12 hours (455 IU/L) and at 65 hours (188 IU/L) after the ingestion. No symptoms were observed before discharge and on follow-up.
Climate change and soil salinity: The case of coastal Bangladesh.
Dasgupta, Susmita; Hossain, Md Moqbul; Huq, Mainul; Wheeler, David
2015-12-01
This paper estimates location-specific soil salinity in coastal Bangladesh for 2050. The analysis was conducted in two stages: First, changes in soil salinity for the period 2001-2009 were assessed using information recorded at 41 soil monitoring stations by the Soil Research Development Institute. Using these data, a spatial econometric model was estimated linking soil salinity with the salinity of nearby rivers, land elevation, temperature, and rainfall. Second, future soil salinity for 69 coastal sub-districts was projected from climate-induced changes in river salinity and projections of rainfall and temperature based on time trends for 20 Bangladesh Meteorological Department weather stations in the coastal region. The findings indicate that climate change poses a major soil salinization risk in coastal Bangladesh. Across 41 monitoring stations, the annual median projected change in soil salinity is 39 % by 2050. Above the median, 25 % of all stations have projected changes of 51 % or higher.
Sardessai, S; Shetye, Suhas; Maya, M V; Mangala, K R; Prasanna Kumar, S
2010-01-01
Nutrient characteristics of four water masses in the light of their thermohaline properties are examined in the eastern Equatorial Indian Ocean during winter, spring and summer monsoon. The presence of low salinity water mass with "Surface enrichments" of inorganic nutrients was observed relative to 20 m in the mixed layer. Lowest oxygen levels of 19 microM at 3 degrees N in the euphotic zone indicate mixing of low oxygen high salinity Arabian Sea waters with the equatorial Indian Ocean. The seasonal variability of nutrients was regulated by seasonally varying physical processes like thermocline elevation, meridional and zonal transport, the equatorial undercurrent and biological processes of uptake and remineralization. Circulation of Arabian Sea high salinity waters with nitrate deficit could also be seen from low N/P ratio with a minimum of 8.9 in spring and a maximum of 13.6 in winter. This large deviation from Redfield N/P ratio indicates the presence of denitrified high salinity waters with a seasonal nitrate deficit ranging from -4.85 to 1.52 in the Eastern Equatorial Indian Ocean. 2010 Elsevier Ltd. All rights reserved.
McCormick, Stephen D.; O'Dea, Michael F.; Moeckel, Amy M.; Lerner, Darrren T.; Bjornsson, Bjorn Thrandur
2005-01-01
Sex steroids are known to interfere with the parr-smolt transformation of anadromous salmonids, and environmental estrogens such as nonylphenol have recently been implicated in reduced returns of Atlantic salmon in the wild. To determine the endocrine pathways by which estrogenic compounds affect smolt development and seawater tolerance, groups of juvenile Atlantic salmon were injected with one of five doses (0.5, 2, 10, 40 or 150 μg g−1) of branched 4-nonylphenol (NP), 2 μg g−1 of 17β-estradiol (E2), or vehicle, during the parr-smolt transformation in April, and the treatment was repeated 4, 8, and 11 days after the first injection. Plasma was obtained for biochemical analysis 7 and 14 days after initiation of treatment. After 14 days of treatment, additional fish from each treatment group were exposed to seawater for 24 h to assess salinity tolerance. The E2 treatment and the highest NP dose resulted in lower salinity tolerance and decreased plasma insulin-like growth factor I (IGF-I) levels, along with elevated levels of plasma vitellogenin and total calcium. Plasma growth hormone levels were elevated at intermediate NP doses only, and not affected by E2. After 7 days, plasma thyroxine (T4) levels decreased in a strong, dose-dependent manner in response to nonylphenol, but after 14 days, this suppressive effect of T4 occurred at the highest NP dose only. Similarly, E2 decreased plasma T4 levels at 7, but not 14 days. Plasma 3,3′,5-triodo-l-thyronine was reduced by E2 and the highest NP dose after 7 and 14 days of treatment. Plasmacortisol levels were not affected by any of the treatments. The results indicate that the parr-smolt transformation and salinity tolerance can be compromised by exposure to estrogenic compounds. Suppression of plasma IGF-I levels is a likely endocrine pathway for the effects of estrogenic compounds on hypo-osmoregulatory capacity, and the detrimental effects of E2 and NP on thyroid hormone levels are also likely to compromise the normal parr-smolt transformation of Atlantic salmon.
Algae contribute to trophic and biogeochemical processes in tidal wetlands. We investigated patterns of sediment pigment content and macroalgal abundance and diversity in marshes in four Oregon estuaries representing a variety of vegetation types, salinity regimes, and tidal ele...
Tipsmark, C K; Madsen, S S
2012-08-01
Molecular regulation of tight junctions in osmoregulatory epithelia of euryhaline fishes must be extensive during ontogeny and acclimation to salinity changes. In this study, five tight junction proteins were examined in Atlantic salmon (Salmo salar): tight junction associated tricellulin, occludin and claudin-3 isoforms (a, b, c). A survey of tissue distribution in freshwater (FW) salmon showed that tricellulin expression was highest in the intestine. Occludin was detected in tissues with importance for epithelial transport and the order of expression was gill>intestine>kidney. The three claudin-3 isoforms were expressed at highest level in kidney tissue. Transfer of juvenile FW salmon to seawater (SW) elevated intestinal tricellulin and occludin mRNA, and these transcripts were also elevated at the time of best SW-tolerance during the course of smoltification. In the kidney, expression of tricellulin and claudin-3 isoforms was elevated after SW-transfer and tricellulin, occludin, claudin-3a and -3b increased in March before the peak smolt stage. In the gill, none of the examined tight junction proteins were impacted by SW-transfer. The data suggest that expression of tricellulin and occludin is dynamically involved in reorganization of intestinal epithelium and possibly changed paracellular permeability during SW-acclimation. The increased renal tricellulin and claudin-3 expression in SW suggests a role in remodeling of the kidney during SW-acclimation. Copyright © 2012 Elsevier Inc. All rights reserved.
NASA Astrophysics Data System (ADS)
Voss, C. I.; Gingerich, S. B.
2015-12-01
Low-lying oceanic islands host thin freshwater lenses subject to long-term aquifer salinization by seawater overwash. The lens is often the sole-source water supply for inhabitants. As maximum elevation for these islands is only a few meters above sea level, overwash can occur during high tides and storm surges. Sea level rise due to climate change will make overwash events even more common. The thin freshwater lenses, a few meters thick, are underlain by seawater, so pumping must be done carefully, often with horizontal skimming wells. Even a small amount of downward seawater infiltration from an overwash event can render the water supply non-potable. Where permeability is high, seawater infiltrates quickly, but seawater that infiltrates lower-permeability zones may remain for many months causing groundwater to remain non-potable, leaving residents without a reliable freshwater source. Initial post-overwash salinization is driven by the higher density of the invading saltwater, which sinks and mixes into the fresher water in potentially-complex patterns determined by: distribution of flooding and post-flood ponding, locations of permeable paths, and the inherently complex flow fields generated when fluid of higher density overlies lower-density fluid. The flow patterns cannot generally be measured or predicted in detail. This study develops basic understanding of overwash salinization processes impacting water supply on low-level islands, using a rare example of a monitored seawater overwash event that occurred in December 2008 at Roi-Namur Island in Kwajalein Atoll, Republic of the Marshall Islands, in which the salinity evolution of well water was measured. Due to typical lack of field data on such islands, a set of plausible alternative simulation-model descriptions of the hydrogeology and overwash event are created for analysis of the monitored salinization and recovery. Despite inability to know the 'true and complete' description of the event and the hydrogeology, the alternative models provide a range of possible evolutions of aquifer salinity. This allows identification of the controls on the rate and extent of initial salinization and of salinity persistence, which can be used as a basis for development of strategies to manage groundwater resources on low-lying islands.
Caccetta, Peter; Dunne, Robert; George, Richard; McFarlane, Don
2010-01-01
In the southwestern agricultural region of Western Australia, the clearing of the original perennial vegetation for annual vegetation-based dryland agriculture has lead to rising saline groundwater levels. This has had effects such as reduced productivity of agricultural land, death of native vegetation, reduced stream water quality and infrastructure damage. These effects have been observed at many locations within the 18 million ha of cleared land. This has lead to efforts to quantify, in a spatially explicit way, the historical and likely future extent of the area affected, with the view to informing management decisions. This study was conducted to determine whether the likely future extent of the area affected by dryland salinity could be estimated by means of developing spatially explicit maps for use in management and planning. We derived catchment-related variables from digital elevation models and perennial vegetation presence/absence maps. We then used these variables to predict the salinity hazard extent by applying a combination of decision tree classification and morphological image processing algorithms. Sufficient objective data such as groundwater depth, its rate of rise, and its concentration of dissolved salts were generally not available, so we used regional expert opinion (derived from the limited existing studies on salinity hazard extent) as training and validation data. We obtained an 87% agreement in the salinity hazard extent estimated by this method compared with the validation data, and conclude that the maps are sufficient for planning. We estimate that the salinity hazard extent is 29.7% of the agricultural land.
NASA Astrophysics Data System (ADS)
Amores, Angel; Melnichenko, Oleg; Maximenko, Nikolai
2017-01-01
The mean vertical structure and transport properties of mesoscale eddies are investigated in the North Atlantic subtropical gyre by combining historical records of Argo temperature/salinity profiles and satellite sea level anomaly data in the framework of the eddy tracking technique. The study area is characterized by a low eddy kinetic energy and sea surface salinity maximum. Although eddies have a relatively weak signal at surface (amplitudes around 3-7 cm), the eddy composites reveal a clear deep signal that penetrates down to at least 1200 m depth. The analysis also reveals that the vertical structure of the eddy composites is strongly affected by the background stratification. The horizontal patterns of temperature/salinity anomalies can be reconstructed by a linear combination of a monopole, related to the elevation/depression of the isopycnals in the eddy core, and a dipole, associated with the horizontal advection of the background gradient by the eddy rotation. A common feature of all the eddy composites reconstructed is the phase coherence between the eddy temperature/salinity and velocity anomalies in the upper ˜300 m layer, resulting in the transient eddy transports of heat and salt. As an application, a box model of the near-surface layer is used to estimate the role of mesoscale eddies in maintaining a quasi-steady state distribution of salinity in the North Atlantic subtropical salinity maximum. The results show that mesoscale eddies are able to provide between 4 and 21% of the salt flux out of the area required to compensate for the local excess of evaporation over precipitation.
Nossel, H. L.; Wasser, J.; Kaplan, K. L.; Lagamma, K. S.; Yudelman, I.; Canfield, R. E.
1979-01-01
Plasma fibrinopeptide B (Bβ1-14 or FPB) immunoreactivity was studied by radioimmunoassay in patients who received intrauterine infusion of hypertonic saline to terminate pregnancy. FPB immunoreactivity increased with thrombin treatment (TIFPB) suggesting the presence of a larger FPB-containing peptide, since purified FPB is not altered by thrombin, whereas thrombin increases the immunoreactivity of Bβ1-42 (which includes FPB) 10-fold. TIFPB immunoreactivity in plasma, drawn 4 h after hypertonic saline infusion eluted from Sephadex G-50 similarly to isolated Bβ1-42. Streptokinase, incubated with normal plasma progressively generated TIFPB immunoreactivity, which showed a major component which eluted from Sephadex G-50 similarly to Bβ1-42. Streptokinase generated TIFPB much more rapidly in reptilase-treated plasma that contains fibrin I, (which still includes FPB), indicating that fibrin I is preferred over fibrinogen as a substrate for plasmin cleavage of arginine (Bβ42)-alanine (Bβ43). Serial studies were then made in 10 patients receiving intrauterine hypertonic saline. Fibrinopeptide A (FPA) levels rose immediately, reached a peak between 1 and 2 h, were declining at 4 h, and were normal at 24 and 48 h. TIFPB levels rose slightly in the 1st h, reached a peak at 4 h, and had returned to base-line values at 24 h. Serum fibrinogen degradation product levels were unchanged at 1 h, reached their highest level at 4 h, and were still markedly elevated at 24 and 48 h. Fibrinogen levels dropped slightly being lowest at 4 and 24 h. Platelet counts declined in parallel with the fibrinogen levels over the first 4 h, but continued to decrease through 48 h. Beta thromboglobulin (βTG) levels generally paralleled FPA levels whereas platelet factor 4 (PF4) levels showed only slight changes. The data indicate that immediately after intrauterine hypertonic saline infusion thrombin is formed that cleaves FPA from fibrinogen to produce fibrin I and releases βTG and PF4 from platelets. Later plasmin cleaves Bβ1-42 from fibrin I to produce fragment X, which is further degraded to form serum fibrinogen degradation products. This sequence of proteolysis indicates that plasmin action on fibrin I serves as a mechanism that regulates fibrin II formation by removing the Bβ chain cleavage site, which is required for thrombin action in converting fibrin I to fibrin II. PMID:500818
Effects of elevated atmospheric CO2 on dissolution of geological fluorapatite in water and soil.
Li, Zhen; Su, Mu; Tian, Da; Tang, Lingyi; Zhang, Lin; Zheng, Yangfan; Hu, Shuijin
2017-12-01
Most of phosphorus (P) is present as insoluble phosphorus-bearing minerals or organic forms in soil. Geological fluorapatite (FAp) is the dominant mineral-weathering source of P. In this study, FAp was added into water and soil under elevated CO 2 to investigate the pathway of P release. Two types of soils (an acidic soil from subtropical China and a saline-alkali soil from Tibet Plateau, China) with similar total P content were studied. In the solution, increased CO 2 in air enhanced the dissolution of FAp, i.e., from 0.04 to 1.18ppm for P and from 2.48 to 13.61ppm for Ca. In addition, release of Ca and P from FAp reached the maximum (2.14ppm for P and 13.84ppm for Ca) under the combination of elevated CO 2 and NaCl due to the increasing ion exchange. Consistent with the results from the solution, CO 2 elevation promoted P release more significantly (triple) in the saline-alkali soil than in the acidic soil. Therefore, saline-alkali soils in Tibet Plateau would be an important reservoir of available P under the global CO 2 rise. This study sheds the light on understanding the geological cycle of phosphorus. Copyright © 2017. Published by Elsevier B.V.
Hein, Travis W; Ren, Yi; Potts, Luke B; Yuan, Zhaoxu; Kuo, Enoch; Rosa, Robert H; Kuo, Lih
2012-01-03
Because retinal vascular disease is associated with ischemia and increased oxidative stress, the vasodilator function of retinal arterioles was examined after retinal ischemia induced by elevated intraocular pressure (IOP). The role of superoxide anions in the development of vascular dysfunction was assessed. IOP was increased and maintained at 80 to 90 mm Hg for 30, 60, or 90 minutes by infusing saline into the anterior chamber of a porcine eye. The fellow eye with normal IOP (10-20 mm Hg) served as control. In some pigs, superoxide dismutase mimetic TEMPOL (1 mM) or vehicle (saline) was injected intravitreally before IOP elevation. After enucleation, retinal arterioles were isolated and pressurized without flow for functional analysis by recording diameter changes using videomicroscopic techniques. Dihydroethidium (DHE) was used to detect superoxide production in isolated retinal arterioles. Isolated retinal arterioles developed stable basal tone and the vasodilations to endothelium-dependent nitric oxide (NO)-mediated agonists bradykinin and L-lactate were significantly reduced only by 90 minutes of ischemia. However, vasodilation to endothelium-independent NO donor sodium nitroprusside was unaffected after all time periods of ischemia. DHE staining showed that 90 minutes of ischemia significantly increased superoxide levels in retinal arterioles. Intravitreal injection of membrane-permeable radical scavenger but not vehicle before ischemia prevented elevation of vascular superoxide and preserved bradykinin-induced dilation. Endothelium-dependent NO-mediated dilation of retinal arterioles is impaired by 90 minutes of ischemia induced by elevated IOP. The inhibitory effect appears to be mediated by the alteration of NO signaling via vascular superoxide.
Gu, Jiajie; Huang, Haoping; Huang, Yuejun; Sun, Haitao; Xu, Hongwu
2018-06-15
Hyperosmolar therapy is regarded as the mainstay for treatment of elevated intracranial pressure (ICP) in traumatic brain injury (TBI). This still has been disputed as application of hypertonic saline (HS) or mannitol for treating patients with severe TBI. Thus, this meta-analysis was performed to further compare the advantages and disadvantages of mannitol with HS for treating elevated ICP after TBI. We conducted a systematic search on PubMed, EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL), Wan Fang Data, VIP Data, SinoMed, and China National Knowledge Infrastructure (CNKI) databases. Studies were included or not based on the quality assessment by the Jadad scale and selection criteria. Twelve RCTs with 438 patients were enrolled for the meta-analysis. The comparison of HS and mannitol indicated that they were close in field of improving function outcome (RR = 1.17, 95% CI 0.89 to 1.54, p = 0.258) and reducing intracranial pressure (MD = - 0.16, 95% CI: - 0.59 to 0.27, p = 0.473) and mortality (RR = 0.78, 95% CI 0.53 to 1.16, p = 0.216). The pooled relative risk of successful ICP control was 1.06 (95% CI: 1.00 to 1.13, p = 0.044), demonstrating that HS was more effective than mannitol in ICP management. Both serum sodium (WMD = 5.30, 95% CI: 4.37 to 6.22, p < 0.001) and osmolality (WMD = 3.03, 95% CI: 0.18 to 5.88, p = 0.037) were increased after injection of hypertonic saline. The results do not lend a specific recommendation to select hypertonic saline or mannitol as a first-line for the patients with elevated ICP caused by TBI. However, for the refractory intracranial hypertension, hypertonic saline seems to be preferred.
NASA Astrophysics Data System (ADS)
Gomez-Tames, Jose; Sugiyama, Yukiya; Laakso, Ilkka; Tanaka, Satoshi; Koyama, Soichiro; Sadato, Norihiro; Hirata, Akimasa
2016-12-01
Transcranial direct current stimulation (tDCS) is a neuromodulation scheme where a small current is delivered to the brain via two electrodes attached to the scalp. The electrode design is an important topic, not only as regards efficacy, but also from a safety perspective, as tDCS may be related to skin lesions that are sometimes observed after stimulation. Previous computational models of tDCS have omitted the effects of microscopic structures in the skin, and the different soak conditions of the electrodes, and model validation has been limited. In this study, multiphysics and multiscale analysis are proposed to demonstrate the importance of microscopic modeling of the skin, in order to clarify the effects of the internal electric field, and to examine temperature elevation around the electrodes. This novel microscopic model of the skin layer took into consideration the effect of saline/water penetration in hair follicles and sweat ducts on the field distribution around the electrodes. The temperature elevation in the skin was then computed by solving the bioheat equation. Also, a multiscale model was introduced to account for macroscopic and microscopic tissues of the head and skin, which was validated by measurement of the head resistance during tDCS. As a result, the electric field in the microscopic model of the skin was less localized when the follicles/ducts were filled with saline instead of hair or tap water. Temperature elevation was also lessened with saline, in comparison with other substances. Saline, which may penetrate the hair follicles and sweat ducts, suppressed the field concentration around the electrodes. For conventional magnitudes of current injection, and a head resistance of less than 10 kΩ, the temperature elevation in the skin when using saline-soaked electrodes was low, less than 0.1 °C, and unlikely to cause adverse thermal effects.
An Experimental Real-Time Ocean Nowcast/Forecast System for Intra America Seas
NASA Astrophysics Data System (ADS)
Ko, D. S.; Preller, R. H.; Martin, P. J.
2003-04-01
An experimental real-time Ocean Nowcast/Forecast System has been developed for the Intra America Seas (IASNFS). The area of coverage includes the Caribbean Sea, the Gulf of Mexico and the Straits of Florida. The system produces nowcast and up to 72 hours forecast the sea level variation, 3D ocean current, temperature and salinity fields. IASNFS consists an 1/24 degree (~5 km), 41-level sigma-z data-assimilating ocean model based on NCOM. For daily nowcast/forecast the model is restarted from previous nowcast. Once model is restarted it continuously assimilates the synthetic temperature/salinity profiles generated by a data analysis model called MODAS to produce nowcast. Real-time data come from satellite altimeter (GFO, TOPEX/Poseidon, ERS-2) sea surface height anomaly and AVHRR sea surface temperature. Three hourly surface heat fluxes, including solar radiation, wind stresses and sea level air pressure from NOGAPS/FNMOC are applied for surface forcing. Forecasts are produced with available NOGAPS forecasts. Once the nowcast/forecast are produced they are distributed through the Internet via the updated web pages. The open boundary conditions including sea surface elevation, transport, temperature, salinity and currents are provided by the NRL 1/8 degree Global NCOM which is operated daily. An one way coupling scheme is used to ingest those boundary conditions into the IAS model. There are 41 rivers with monthly discharges included in the IASNFS.
How Do Changes to the Railroad Causeway in Utah’s Great Salt Lake Affect Water and Salt Flow?
White, James S.; Null, Sarah E.; Tarboton, David G.
2015-01-01
Managing terminal lake elevation and salinity are emerging problems worldwide. We contribute to terminal lake management research by quantitatively assessing water and salt flow for Utah’s Great Salt Lake. In 1959, Union Pacific Railroad constructed a rock-filled causeway across the Great Salt Lake, separating the lake into a north and south arm. Flow between the two arms was limited to two 4.6 meter wide rectangular culverts installed during construction, an 88 meter opening (referred to locally as a breach) installed in 1984, and the semi porous material of the causeway. A salinity gradient developed between the two arms of the lake over time because the south arm receives approximately 95% of the incoming streamflow entering Great Salt Lake. The north arm is often at, or near, salinity saturation, averaging 317 g/L since 1966, while the south is considerably less saline, averaging 142 g/L since 1966. Ecological and industrial uses of the lake are dependent on long-term salinity remaining within physiological and economic thresholds, although optimal salinity varies for the ecosystem and between diverse stakeholders. In 2013, Union Pacific Railroad closed causeway culverts amid structural safety concerns and proposed to replace them with a bridge, offering four different bridge designs. As of summer 2015, no bridge design has been decided upon. We investigated the effect that each of the proposed bridge designs would have on north and south arm Great Salt Lake elevation and salinity by updating and applying US Geological Survey’s Great Salt Lake Fortran Model. Overall, we found that salinity is sensitive to bridge size and depth, with larger designs increasing salinity in the south arm and decreasing salinity in the north arm. This research illustrates that flow modifications within terminal lakes cannot be separated from lake salinity, ecology, management, and economic uses. PMID:26641101
How Do Changes to the Railroad Causeway in Utah's Great Salt Lake Affect Water and Salt Flow?
White, James S; Null, Sarah E; Tarboton, David G
2015-01-01
Managing terminal lake elevation and salinity are emerging problems worldwide. We contribute to terminal lake management research by quantitatively assessing water and salt flow for Utah's Great Salt Lake. In 1959, Union Pacific Railroad constructed a rock-filled causeway across the Great Salt Lake, separating the lake into a north and south arm. Flow between the two arms was limited to two 4.6 meter wide rectangular culverts installed during construction, an 88 meter opening (referred to locally as a breach) installed in 1984, and the semi porous material of the causeway. A salinity gradient developed between the two arms of the lake over time because the south arm receives approximately 95% of the incoming streamflow entering Great Salt Lake. The north arm is often at, or near, salinity saturation, averaging 317 g/L since 1966, while the south is considerably less saline, averaging 142 g/L since 1966. Ecological and industrial uses of the lake are dependent on long-term salinity remaining within physiological and economic thresholds, although optimal salinity varies for the ecosystem and between diverse stakeholders. In 2013, Union Pacific Railroad closed causeway culverts amid structural safety concerns and proposed to replace them with a bridge, offering four different bridge designs. As of summer 2015, no bridge design has been decided upon. We investigated the effect that each of the proposed bridge designs would have on north and south arm Great Salt Lake elevation and salinity by updating and applying US Geological Survey's Great Salt Lake Fortran Model. Overall, we found that salinity is sensitive to bridge size and depth, with larger designs increasing salinity in the south arm and decreasing salinity in the north arm. This research illustrates that flow modifications within terminal lakes cannot be separated from lake salinity, ecology, management, and economic uses.
Ohio River backwater flood-inundation maps for the Saline and Wabash Rivers in southern Illinois
Murphy, Elizabeth A.; Sharpe, Jennifer B.; Soong, David T.
2012-01-01
Digital flood-inundation maps for the Saline and Wabash Rivers referenced to elevations on the Ohio River in southern Illinois were created by the U.S. Geological Survey (USGS). The inundation maps, accessible through the USGS Flood Inundation Mapping Science Web site at http://water.usgs.gov/osw/flood_inundation/, depict estimates of the areal extent of flooding corresponding to selected water levels (gage heights) at the USGS streamgage at Ohio River at Old Shawneetown, Illinois-Kentucky (station number 03381700). Current gage height and flow conditions at this USGS streamgage may be obtained on the Internet at http://waterdata.usgs.gov/usa/nwis/uv?03381700. In addition, this streamgage is incorporated into the Advanced Hydrologic Prediction Service (AHPS) flood warning system (http://water.weather.gov/ahps/) by the National Weather Service (NWS). The NWS forecasts flood hydrographs at many places that are often co-located at USGS streamgages. That NWS forecasted peak-stage information, also shown on the Ohio River at Old Shawneetown inundation Web site, may be used in conjunction with the maps developed in this study to show predicted areas of flood inundation. In this study, eight water-surface elevations were mapped at 5-foot (ft) intervals referenced to the streamgage datum ranging from just above the NWS Action Stage (31 ft) to above the maximum historical gage height (66 ft). The elevations of the water surfaces were compared to a Digital Elevation Model (DEM) by using a Geographic Information System (GIS) in order to delineate the area flooded at each water level. These maps, along with information on the Internet regarding current gage heights from USGS streamgages and forecasted stream stages from the NWS, provide emergency management personnel and residents with information that is critical for flood response activities such as evacuations and road closures, as well as for post-flood recovery efforts.
Kwok, K W H; Leung, K M Y
2005-01-01
Intertidal harpacticoid copepods are commonly used in eco-toxicity tests worldwide. They predominately live in mid-high shore rock pools and often experience a wide range of temperature and salinity fluctuation. Most eco-toxicity tests are conducted at fixed temperature and salinity and thus the influence of these environmental factors on chemical toxicity is largely unknown. This study investigated the combined effect of temperature and salinity on the acute toxicity of the copepod Tigriopus japonicus against two common biocides, copper (Cu) and tributyltin (TBT) using a 2 x 3 x 4 factorial design (i.e. two temperatures: 25 and 35 degrees C; three salinities: 15.0 per thousand, 34.5 per thousand and 45.0 per thousand; three levels of the biocide plus a control). Copper sulphate and tributyltin chloride were used as the test chemicals while distilled water and acetone were utilised as solvents for Cu and TBT respectively. 96 h-LC50s of Cu and TBT were 1024 and 0.149 microg l(-1) respectively (at 25 degrees C; 34.5 per thousand) and, based on these results, nominal biocide concentrations of LC0 (i.e. control), LC30, LC50 and LC70 were employed. Analysis of Covariance using 'concentration' as the covariate and both 'temperature' and 'salinity' as fixed factors, showed a significant interaction between temperature and salinity effects for Cu, mortality increasing with temperature but decreasing with elevated salinity. A similar result was revealed for TBT. Both temperature and salinity are, therefore, important factors affecting the results of acute eco-toxicity tests using these marine copepods. We recommend that such eco-toxicity tests should be conducted at a range of environmentally realistic temperature/salinity regimes, as this will enhance the sensitivity of the test and improve the safety margin in line with the precautionary principle.
EXOGENOUS CYTOCHROME C RESTORES MYOCARDIAL CYTOCHROME OXIDASE ACTIVITY INTO THE LATE PHASE OF SEPSIS
Piel, David A.; Deutschman, Clifford S.; Levy, Richard J.
2009-01-01
Mitochondrial dysfunction is thought to play a role in the pathogenesis of a variety of disease states, including sepsis. An acquired defect in oxidative phosphorylation potentially causes sepsis-induced organ dysfunction. Cytochrome oxidase (CcOX), the terminal oxidase of the respiratory chain, is competitively inhibited early in sepsis and progresses, becoming noncompetitive during the late phase. We have previously demonstrated that exogenous cytochrome c can overcome myocardial CcOX competitive inhibition and improve cardiac function during murine sepsis at the 24-h point. Here, we evaluate the effect of exogenous cytochrome c on CcOX activity and survival in mice at the later time points. Exogenous cytochrome c (800 μg) or saline was intravenously injected 24 h after cecal ligation and puncture (CLP) or sham operation. Steady-state mitochondrial cytochrome c levels and heme c content increased significantly 48 h post-CLP and remained elevated at 72 h in cytochrome c-injected mice compared with saline injection. Cecal ligation and puncture inhibited CcOX at 48 h in saline-injected mice. However, cytochrome c injection abrogated this inhibition and restored CcOX kinetic activity to sham values at 48 h. Survival after CLP to 96 h after cytochrome c injection approached 50% compared with only 15% after saline injection. Thus, a single injection of exogenous cytochrome c 24 h post-CLP repletes mitochondrial substrate levels for up to 72 h, restores myocardial COX activity, and significantly improves survival. PMID:18414235
Xu, Jia; Sun, Jinling; Xue, Zhaoxia; Li, Xinwang
2014-06-18
This study investigated the relationships among an enriched environment, stress levels, and drug addiction. Mice were divided randomly into four treatment groups (n=12 each): enriched environment without restraint stress (EN), standard environment without restraint stress (SN), enriched environment with restraint stress (ES), and standard environment with restraint stress (SS). Mice were reared in the respective environment for 45 days. Then, the ES and SS groups were subjected to restraint stress daily (2 h/day) for 14 days, whereas the EN and SN groups were not subjected to restraint stress during this stage. The stress levels of all mice were tested in the elevated plus maze immediately after exposure to restraint stress. After the 2-week stress testing period, mice were administered acute or chronic morphine (5 mg/kg) treatment for 7 days. Then, after a 7-day withdrawal period, the mice were injected with saline (1 ml/kg) or morphine (5 mg/kg) daily for 2 days to observe locomotor activity. The results indicated that the enriched environment reduced the stress and locomotor activity induced by acute morphine administration or saline after chronic morphine treatment. However, the enriched environment did not significantly inhibit locomotor activity induced by morphine challenge. In addition, the stress level did not mediate the effect of the enriched environment on drug-induced locomotor activity after acute or chronic morphine treatment.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ashley, J.T.F.; Secor, D.H.; Zlokovitz, E.
2000-03-15
Since 1976, the commercial striped bass fishery in the Hudson River (NY) has been closed due to total polychlorinated biphenyl (t-PCB) concentrations that exceed the US Food and Drug Administration's advisory level of 2 {micro}g/g-wet weight. Extensive monitoring of Hudson River striped bass demonstrated much more variability in t-PCB levels among individual striped bass than could be explained by their age, sex, or lipid contents. To investigate the possible role of differential habitat use among subpopulations of striped bass in controlling their PCB exposures, 70 fish collected throughout the Hudson River estuary and Long Island Sound in 1994--1995 were analyzedmore » for PCB congeners, and their lifetime migration behaviors were estimated by otolith microchemistry. The mean salinity encountered during the fish's last growth season prior to capture was inversely correlated with the t-PCB body burden. Striped bass permanently residing in fresh and oligohaline portions of the estuary adjacent to known PCB sources had elevated t-PCB levels and congeneric patterns with higher proportions of di-, tri-, and tetrachlorobiphenyls. Conversely, fish spending the majority of their life in more saline waters of the estuary or migrating frequently throughout the salinity gradient contained lower PCB levels composed of more highly chlorinated congeners. The approach used in this study allows habitat use to be incorporated into exposure assessments for anadromous fish species such as striped bass.« less
Exploratory Hydrocarbon Drilling Impacts to Arctic Lake Ecosystems
Thienpont, Joshua R.; Kokelj, Steven V.; Korosi, Jennifer B.; Cheng, Elisa S.; Desjardins, Cyndy; Kimpe, Linda E.; Blais, Jules M.; Pisaric, Michael FJ.; Smol, John P.
2013-01-01
Recent attention regarding the impacts of oil and gas development and exploitation has focused on the unintentional release of hydrocarbons into the environment, whilst the potential negative effects of other possible avenues of environmental contamination are less well documented. In the hydrocarbon-rich and ecologically sensitive Mackenzie Delta region (NT, Canada), saline wastes associated with hydrocarbon exploration have typically been disposed of in drilling sumps (i.e., large pits excavated into the permafrost) that were believed to be a permanent containment solution. However, failure of permafrost as a waste containment medium may cause impacts to lakes in this sensitive environment. Here, we examine the effects of degrading drilling sumps on water quality by combining paleolimnological approaches with the analysis of an extensive present-day water chemistry dataset. This dataset includes lakes believed to have been impacted by saline drilling fluids leaching from drilling sumps, lakes with no visible disturbances, and lakes impacted by significant, naturally occurring permafrost thaw in the form of retrogressive thaw slumps. We show that lakes impacted by compromised drilling sumps have significantly elevated lakewater conductivity levels compared to control sites. Chloride levels are particularly elevated in sump-impacted lakes relative to all other lakes included in the survey. Paleolimnological analyses showed that invertebrate assemblages appear to have responded to the leaching of drilling wastes by a discernible increase in a taxon known to be tolerant of elevated conductivity coincident with the timing of sump construction. This suggests construction and abandonment techniques at, or soon after, sump establishment may result in impacts to downstream aquatic ecosystems. With hydrocarbon development in the north predicted to expand in the coming decades, the use of sumps must be examined in light of the threat of accelerated permafrost thaw, and the potential for these industrial wastes to impact sensitive Arctic ecosystems. PMID:24223170
Exploratory hydrocarbon drilling impacts to Arctic lake ecosystems.
Thienpont, Joshua R; Kokelj, Steven V; Korosi, Jennifer B; Cheng, Elisa S; Desjardins, Cyndy; Kimpe, Linda E; Blais, Jules M; Pisaric, Michael F J; Smol, John P
2013-01-01
Recent attention regarding the impacts of oil and gas development and exploitation has focused on the unintentional release of hydrocarbons into the environment, whilst the potential negative effects of other possible avenues of environmental contamination are less well documented. In the hydrocarbon-rich and ecologically sensitive Mackenzie Delta region (NT, Canada), saline wastes associated with hydrocarbon exploration have typically been disposed of in drilling sumps (i.e., large pits excavated into the permafrost) that were believed to be a permanent containment solution. However, failure of permafrost as a waste containment medium may cause impacts to lakes in this sensitive environment. Here, we examine the effects of degrading drilling sumps on water quality by combining paleolimnological approaches with the analysis of an extensive present-day water chemistry dataset. This dataset includes lakes believed to have been impacted by saline drilling fluids leaching from drilling sumps, lakes with no visible disturbances, and lakes impacted by significant, naturally occurring permafrost thaw in the form of retrogressive thaw slumps. We show that lakes impacted by compromised drilling sumps have significantly elevated lakewater conductivity levels compared to control sites. Chloride levels are particularly elevated in sump-impacted lakes relative to all other lakes included in the survey. Paleolimnological analyses showed that invertebrate assemblages appear to have responded to the leaching of drilling wastes by a discernible increase in a taxon known to be tolerant of elevated conductivity coincident with the timing of sump construction. This suggests construction and abandonment techniques at, or soon after, sump establishment may result in impacts to downstream aquatic ecosystems. With hydrocarbon development in the north predicted to expand in the coming decades, the use of sumps must be examined in light of the threat of accelerated permafrost thaw, and the potential for these industrial wastes to impact sensitive Arctic ecosystems.
Something new from something old? Fracking stimulated microbial processes
NASA Astrophysics Data System (ADS)
Wrighton, K. C.; Daly, R. A.; Hoyt, D.; Trexler, R.; McRae, J.; Wilkins, M.; Mouser, P. J.
2015-12-01
Hydraulic fracturing, colloquially known as "fracking", is employed for effective gas and oil recovery in deep shales. This process injects organisms and liquids from the surface into the deep subsurface (~2500 m), exposing microorganisms to high pressures, elevated temperatures, chemical additives, and brine-level salinities. Here we use assembly-based metagenomics to create a metabolic blueprint from an energy-producing Marcellus shale well over a 328-day period. Using this approach we ask the question: What abiotic and biotic factors drive microbial metabolism and thus biogeochemical cycling during natural gas extraction? We found that after 49 days, increased salinity in produced waters corresponded to a shift in the microbial community, with only organisms that encode salinity adaptations detected. We posit that organic compatible solutes, produced by organisms adapting to increased salinity, fuels a methylamine-driven ecosystem in fractured shale. This metabolic network ultimately results in biogenic methane production from members of Methanohalophilus and Methanolobus. Proton NMR validated these genomic hypotheses, with mono-methylamine being highest in the input material, but detected throughout the sampling. Beyond abiotic constraints, our genomic investigations revealed that viruses can be linked to key members of the microbial community, potentially releasing methylamine osmoprotectants and impacting bacterial strain variation. Collectively our results indicate that adaptation to high salinity, metabolism in the absence of oxidized electron acceptors, and viral predation are controlling factors mediating microbial community metabolism during hydraulic fracturing of the deep subsurface.
An overview of the Central Queensland University self-contained evapotranspiration beds.
Kele, B; Midmore, D J; Harrower, K; McKennariey, B J; Hood, B
2005-01-01
The Central Queensland University (CQU) has championed a self-contained concrete lined evapotranspiration channel. Any non-transpired effluent returns to a holding tank and is recirculated through the evapotranspiration channel until it is used. This paper examines the results from the Rockhampton trial site. Nutrient ions in the effluent were quantified over time and found not to accumulate in solution. Microbial analysis of the treated effluent was performed and was found to be within the ranges required by the relevant legislative codes. Citrus fruit grown in the evapotranspiration channel were sampled and no elevated levels of faecal coliforms were recorded. Macronutrients and micronutrients of the soil in the channels were measured over a 5-year period. No toxic accumulations or nutrient deficiencies in the soil occurred. Levels of salinity and sodicity in the evapotranspiration channel soil were quantified. Salinity rose slightly, as did sodium. Concentrations of salts and sodium did not reach unsustainable levels. The aim of the trial was to develop an on-site treatment and reuse system that is sustainable and protects public and environmental health.
Effects of Clofibrate on Salt Loading-Induced Hypertension in Rats
Cruz, Antonio; Rodríguez-Gómez, Isabel; Pérez-Abud, Rocío; Vargas, Miguel Ángel; Wangensteen, Rosemary; Quesada, Andrés; Osuna, Antonio; Moreno, Juan Manuel
2011-01-01
The effects of clofibrate on the hemodynamic and renal manifestations of increased saline intake were analyzed. Four groups of male Wistar rats were treated for five weeks: control, clofibrate (240 mg/kg/day), salt (2% via drinking water), and salt + clofibrate. Body weight, systolic blood pressure (SBP), and heart rate (HR) were recorded weekly. Finally, SBP, HR, and morphologic, metabolic, plasma, and renal variables were measured. Salt increased SBP, HR, urinary isoprostanes, NOx, ET, vasopressin and proteinuria and reduced plasma free T4 (FT4) and tissue FT4 and FT3 versus control rats. Clofibrate prevented the increase in SBP produced by salt administration, reduced the sodium balance, and further reduced plasma and tissue thyroid hormone levels. However, clofibrate did not modify the relative cardiac mass, NOx, urinary ET, and vasopressin of saline-loaded rats. In conclusion, chronic clofibrate administration prevented the blood pressure elevation of salt-loaded rats by decreasing sodium balance and reducing thyroid hormone levels. PMID:20981147
1986-09-18
plain, where plant and animal communities are highly sensitive to changes in elevation and salinity , changing shorelines and stream patterns can...material accumulates, shallow bodies of water and intertidal mudflats are created. Along the seaward edge, brackish and saline marshes develop. The...old lobe allow the salinity of inland swamps to increase, causing them to die out. The natural levees of the abandoned distributaries, in the absence
Pierce, A L; Fox, B K; Davis, L K; Visitacion, N; Kitahashi, T; Hirano, T; Grau, E G
2007-01-01
In fish, pituitary growth hormone family peptide hormones (growth hormone, GH; prolactin, PRL; somatolactin, SL) regulate essential physiological functions including osmoregulation, growth, and metabolism. Teleost GH family hormones have both differential and overlapping effects, which are mediated by plasma membrane receptors. A PRL receptor (PRLR) and two putative GH receptors (GHR1 and GHR2) have been identified in several teleost species. Recent phylogenetic analyses and binding studies suggest that GHR1 is a receptor for SL. However, no studies have compared the tissue distribution and physiological regulation of all three receptors. We sequenced GHR2 from the liver of the Mozambique tilapia (Oreochromis mossambicus), developed quantitative real-time PCR assays for the three receptors, and assessed their tissue distribution and regulation by salinity and fasting. PRLR was highly expressed in the gill, kidney, and intestine, consistent with the osmoregulatory functions of PRL. PRLR expression was very low in the liver. GHR2 was most highly expressed in the muscle, followed by heart, testis, and liver, consistent with this being a GH receptor with functions in growth and metabolism. GHR1 was most highly expressed in fat, liver, and muscle, suggesting a metabolic function. GHR1 expression was also high in skin, consistent with a function of SL in chromatophore regulation. These findings support the hypothesis that GHR1 is a receptor for SL. In a comparison of freshwater (FW)- and seawater (SW)-adapted tilapia, plasma PRL was strongly elevated in FW, whereas plasma GH was slightly elevated in SW. PRLR expression was reduced in the gill in SW, consistent with PRL's function in freshwater adaptation. GHR2 was elevated in the kidney in FW, and correlated negatively with plasma GH, whereas GHR1 was elevated in the gill in SW. Plasma IGF-I, but not GH, was reduced by 4 weeks of fasting. Transcript levels of GHR1 and GHR2 were elevated by fasting in the muscle. However, liver levels of GHR1 and GHR2 transcripts, and liver and muscle levels of IGF-I transcripts were unaffected by fasting. These results clearly indicate tissue specific expression and differential physiological regulation of GH family receptors in the tilapia.
Réus, Gislaine Z; Simões, Lutiana R; Colpo, Gabriela D; Scaini, Giselli; Oses, Jean P; Generoso, Jaqueline S; Prossin, Alan R; Kaddurah-Daouk, Rima; Quevedo, João; Barichello, Tatiana
2017-06-14
Immune activation (IA) during the early neonatal period is a risk factor for the development of schizophrenia. Lipopolysaccharide (LPS) injected in neonates lead to behavioral and brain changes that persist to adult life. We investigated oxidative stress, levels of cytokines, and the locomotor activity of IA in a schizophrenia animal model in which neonatal male Wistar rats were administered with an injection of LPS (50μg/kg) on postnatal day 3 and different doses of ketamine (5, 15 and 25mg/kg) for 7days during adulthood. Rats LPS-induced did not have locomotor activity alterations. Locomotor activity was elevated in neonatally saline-injected in the higher dose ketamine-treated animals. Carbonyl protein in the prefrontal cortex (PFC), hippocampus and striatum were increased in the LPS- and saline-induced in the ketamine (25mg/kg)-treated animals. Lipid damage occurred in the PFC, striatum and hippocampus in the LPS- and saline-induced in the ketamine (15 and 25mg/kg) -treated animals. In the hippocampus the superoxide dismutase (SOD) was decreased in the LPS- and saline-induced in the ketamine-treated with the dose of 25mg/kg. In the PFC SOD was reduced in the LPS-induced in the ketamine (25mg/kg)-treated animals. Catalase in the PFC and hippocampus was reduced in the LPS- and saline-induced in the ketamine (25mg/kg)-treated animals. Pro- and anti-inflammatory cytokines were lower in the brains of LPS-induced in the higher dose ketamine-treated rats. IA influences the locomotor activity and cytokine levels induced by ketamine, and it has a negative effect in potentiating the oxidative stress by higher doses of ketamine in the brain. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.
NASA Astrophysics Data System (ADS)
Rahman, M.; Tokunaga, T.
2017-12-01
The Khulna city, situated in the southwestern coastal Bangladesh, has been abstracting deep groundwater (DGW, >150 m below ground level, bgl) since 1970s due to the prevalence of salinity, iron, and arsenic in shallow groundwater (SGW, <150 m bgl). In this study, we obtained environmental isotopes (δ18O, δ2H, δ13C, 3H, and 14C) and geochemical data to constrain the sources of recharge and the possible reasons for salinization of DGW. Samples were collected from DGW, SGW, pond water (PndW), and river water (RW). δ18O and δ2H of DGW, SGW, and RW fall on the local meteoric water line (LMWL) whereas PndW shows evaporation effect as plotted below the LMWL. All these water features form distinct clusters among one another. DGW was not recharged from modern precipitation as 3H values were below detection limit (0.3 TU). 14C activities of 7.9 to 17.5 pMC and apparent radiocarbon age of around 14-21 ka most probably indicate the recharge with paleo-meteoric water. However, elevated 3H and 14C in SGW, reported in recent studies, suggest their recharge with modern precipitation. Neither modern seawater nor SGW influences the salinization of DGW as perceived from a cross plot between Cl- and δ18O. Salinity in DGW might have evolved through mineral dissolution, rock weathering, or mixing with paleo-brackish water. Although DGW level and SGW level fluctuate similarly with monsoon rainfall and river stages, we found no direct connection between SGW and DGW with respect to geochemical and isotopic signatures. Further efforts are necessary for improved understanding of the system for sustainable groundwater management and ensuring long-term freshwater supply for the Khulna city, Bangladesh.
Seasonal pattern of anthropogenic salinization in temperate forested headwater streams.
Timpano, Anthony J; Zipper, Carl E; Soucek, David J; Schoenholtz, Stephen H
2018-04-15
Salinization of freshwaters by human activities is of growing concern globally. Consequences of salt pollution include adverse effects to aquatic biodiversity, ecosystem function, human health, and ecosystem services. In headwater streams of the temperate forests of eastern USA, elevated specific conductance (SC), a surrogate measurement for the major dissolved ions composing salinity, has been linked to decreased diversity of aquatic insects. However, such linkages have typically been based on limited numbers of SC measurements that do not quantify intra-annual variation. Effective management of salinization requires tools to accurately monitor and predict salinity while accounting for temporal variability. Toward that end, high-frequency SC data were collected within the central Appalachian coalfield over 4 years at 25 forested headwater streams spanning a gradient of salinity. A sinusoidal periodic function was used to model the annual cycle of SC, averaged across years and streams. The resultant model revealed that, on average, salinity deviated approximately ±20% from annual mean levels across all years and streams, with minimum SC occurring in late winter and peak SC occurring in late summer. The pattern was evident in headwater streams influenced by surface coal mining, unmined headwater reference streams with low salinity, and larger-order salinized rivers draining the study area. The pattern was strongly responsive to varying seasonal dilution as driven by catchment evapotranspiration, an effect that was amplified slightly in unmined catchments with greater relative forest cover. Evaluation of alternative sampling intervals indicated that discrete sampling can approximate the model performance afforded by high-frequency data but model error increases rapidly as discrete sampling intervals exceed 30 days. This study demonstrates that intra-annual variation of salinity in temperate forested headwater streams of Appalachia USA follows a natural seasonal pattern, driven by interactive influences on water quantity and quality of climate, geology, and terrestrial vegetation. Because climatic and vegetation dynamics vary annually in a seasonal, cyclic manner, a periodic function can be used to fit a sinusoidal model to the salinity pattern. The model framework used here is broadly applicable in systems with streamflow-dependent chronic salinity stress. Copyright © 2018 Elsevier Ltd. All rights reserved.
Mutant matrix metalloproteinase-9 reduces postoperative peritoneal adhesions in rats.
Atta, Hussein; El-Rehany, Mahmoud; Roeb, Elke; Abdel-Ghany, Hend; Ramzy, Maggie; Gaber, Shereen
2016-02-01
Postoperative peritoneal adhesions continue to be a major source of morbidity and occasional mortality. Studies have shown that matrix metalloproteinase-9 (MMP-9) levels are decreased postoperatively which may limits matrix degradation and participate in the development of peritoneal adhesions. In this proof-of-principle study, we evaluated the effect of gene therapy with catalytically inactive mutant MMP-9 on postoperative peritoneal adhesions in rats. Adenovirus encoding mutant MMP-9 (Ad-mMMP-9) or saline was instilled in the peritoneal cavity after cecal and parietal peritoneal injury in rats. Expression of mutant MMP-9 transcript was verified by sequencing. Adenovirus E4 gene expression, adhesion scores, MMP-9, tissue plasminogen activator (tPA), plasminogen activator inhibitor-1 (PAI-1) and transforming growth factor-β1 (TGF-β1) expression were evaluated at sacrifice one week after treatment. Both mutant MMP-9 transcripts and adenovirus E4 gene were expressed in Ad-mMMP-9 treated adhesions. Adhesions severity decreased significantly (p = 0.036) in the Ad-mMMP-9-treated compared with saline-treated adhesions. Expression of MMP-9 mRNA and protein were elevated (p = 0.001 and p = 0.029, respectively) in the Ad-mMMP-9-treated adhesions compared with saline-treated adhesions. While tPA levels were increased (p = 0.02) in Ad-mMMP-9 treated adhesions compared with saline-treated adhesions, TGF-β1 and PAI-1 levels were decreased (p = 0.017 and p = 0.042, respectively). No difference in mortality were found between groups (p = 0.64). Mutant MMP-9 gene therapy effectively transduced peritoneal adhesions resulting in reduction of severity of primary peritoneal adhesions. Copyright © 2016 IJS Publishing Group Limited. Published by Elsevier Ltd. All rights reserved.
Delaune, R D; Gambrell, R P; Jugsujinda, Aroon; Devai, Istavan; Hou, Aixin
2008-07-15
Concentration of total Hg, methyl Hg, and other heavy metals were determined in sediment collected along a salinity gradient in a Louisiana Gulf Coast estuary. Surface sediment was collected at established coordinates (n = 292) along a salinity gradient covering Lake Maurepas, Lake Pontchartrain, Lake Borgne and the Chandeleur Sound located in the 12,170 km(2) Pontchartrain basin estuary southeastern coastal Louisiana. Lake Maurepas sediment with lower salinity contained higher levels of methyl Hg (0.80 microg/kg) than Lake Pontchartrain (0.55 microg/kg). Lake Maurepas sediment also had higher levels of total Hg (98.0 microg/kg) as compared to Lake Pontchartrain (67.0 microg/kg). Average total Hg content of Lake Borgne and the Chandeleur Sound sediment was 24.0 microg/kg dry sediment and methyl Hg content averaged 0.21 microg/kg dry sediment. Methyl Hg content of sediment was positively correlated with total Hg, organic matter and clay content of sediment. Methyl Hg was inversely correlated with salinity, sediment Eh and sand content. Total Hg and methyl Hg decreased with increase in salinity in the order of Lake Maurepas > Lake Pontchartrain > Lake Borgne/ the Chandeleur Sound. Lake Maurepas containing several times higher amount of methyl Hg in sediment as compared to Lake Pontchartrain and Lake Borgne and the Chandeleur Sound is an area that could serve as potential source of mercury to the aquatic food chain. Methyl Hg content of sediment in the estuary could be predicted by the equation: Methyl Hg = 0.11670-0.0625 x Salinity + 0.05349 x O.M. + 0.00513 x Total Hg - 0.00250 x Clay. Concentrations of other toxic heavy metals (Pb, Cd, Ni, Cu and Zn) in sediment were not elevated and was statistically correlated with sediment texture and iron and aluminum content of sediment.
Oxygen isotope geochemistry of Laurentide ice-sheet meltwater across Termination I
NASA Astrophysics Data System (ADS)
Vetter, Lael; Spero, Howard J.; Eggins, Stephen M.; Williams, Carlie; Flower, Benjamin P.
2017-12-01
We present a new method that quantifies the oxygen isotope geochemistry of Laurentide ice-sheet (LIS) meltwater across the last deglaciation, and reconstruct decadal-scale variations in the δ18O of LIS meltwater entering the Gulf of Mexico between ∼18 and 11 ka. We employ a technique that combines laser ablation ICP-MS (LA-ICP-MS) and oxygen isotope analyses on individual shells of the planktic foraminifer Orbulina universa to quantify the instantaneous δ18Owater value of Mississippi River outflow, which was dominated by meltwater from the LIS. For each individual O. universa shell, we measure Mg/Ca (a proxy for temperature) and Ba/Ca (a proxy for salinity) with LA-ICP-MS, and then analyze the same O. universa for δ18O using the remaining material from the shell. From these proxies, we obtain δ18Owater and salinity estimates for each individual foraminifer. Regressions through data obtained from discrete core intervals yield δ18Ow vs. salinity relationships with a y-intercept that corresponds to the δ18Owater composition of the freshwater end-member. Our data suggest that from 15.5 through 14.6 ka, estimated δ18Ow values of Mississippi River discharge from discrete core intervals range from -11‰ to -21‰ VSMOW, which is consistent with δ18O values from both regional precipitation and the low-elevation, southern margin of the LIS. During the Bølling and Allerød (14.0 through 13.3 ka), estimated δ18Ow values of Mississippi River discharge from discrete core intervals range from -22‰ to -38‰ VSMOW. These values suggest a dynamic melting history of different parts of the LIS, with potential contributions to Mississippi River outflow from both the low-elevation, southern margin of the LIS and high-elevation, high-latitude domes in the LIS interior that were transported to the ablation zone. Prior to ∼15.5 ka, the δ18Owater value of the Mississippi River was similar to that of regional precipitation or low-latitude LIS meltwater, but the Ba concentration in the Mississippi basin was affected by changes in weathering within the watershed, complicating Ba-salinity relationships in the Gulf of Mexico. After 13 ka, our data suggest Mississippi River outflow did not influence surface salinity above our Gulf of Mexico Orca Basin core site. Rather, we hypothesize that open ocean conditions prevailed as sea level rose and the paleoshoreline at the southern edge of North America retreated northward.
Sympathetic neural overactivity in healthy humans after prolonged exposure to hypobaric hypoxia
Hansen, Jim; Sander, Mikael
2003-01-01
Acute exposure to hypoxia causes chemoreflex activation of the sympathetic nervous system. During acclimatization to high altitude hypoxia, arterial oxygen content recovers, but it is unknown to what degree sympathetic activation is maintained or normalized during prolonged exposure to hypoxia. We therefore measured sympathetic nerve activity directly by peroneal microneurography in eight healthy volunteers (24 ± 2 years of age) after 4 weeks at an altitude of 5260 m (Chacaltaya, Bolivian Andes) and at sea level (Copenhagen). The subjects acclimatized well to altitude, but in every subject sympathetic nerve activity was highly elevated at altitude vs. sea level (48 ± 5 vs. 16 ± 3 bursts min−1, respectively, P < 0.05), coinciding with increased mean arterial blood pressure (87 ± 3 vs. 77 ± 2 mmHg, respectively, P < 0.05). To examine the underlying mechanisms, we administered oxygen (to eliminate chemoreflex activation) and saline (to reduce cardiopulmonary baroreflex deactivation). These interventions had minor effects on sympathetic activity (48 ± 5 vs. 38 ± 4 bursts min−1, control vs. oxygen + saline, respectively, P < 0.05). Moreover, sympathetic activity was still markedly elevated (37 ± 5 bursts min−1) when subjects were re-studied under normobaric, normoxic and hypervolaemic conditions 3 days after return to sea level. In conclusion, acclimatization to high altitude hypoxia is accompanied by a striking and long-lasting sympathetic overactivity. Surprisingly, chemoreflex activation by hypoxia and baroreflex deactivation by dehydration together could account for only a small part of this response, leaving the major underlying mechanisms unexplained. PMID:12563015
Yan, Kun; Cui, Mingxing; Zhao, Shijie; Chen, Xiaobing; Tang, Xiaoli
2016-01-01
Honeysuckle (Lonicera japonica Thunb.) is a traditional medicinal plant in China that is particularly rich in chlorogenic acids, which are phenolic compounds with various medicinal properties. This study aimed to examine the effects of salinity stress on accumulation of chlorogenic acids in honeysuckle, through hydroponic experiments and field trials, and to examine the mechanisms underlying the effects. NaCl stress stimulated the transcription of genes encoding key enzymes in the synthesis of chlorogenic acids in leaves; accordingly, the concentrations of chlorogenic acids in leaves were significantly increased under NaCl stress, as was antioxidant activity. Specifically, the total concentration of leaf chlorogenic acids was increased by 145.74 and 50.34% after 30 days of 150 and 300 mM NaCl stress, respectively. Similarly, the concentrations of chlorogenic acids were higher in the leaves of plants in saline, compared with non-saline, plots, with increases in total concentrations of chlorogenic acids of 56.05 and 105.29% in October 2014 and 2015, respectively. Despite leaf biomass reduction, absolute amounts of chlorogenic acids per plant and phenylalanine ammonia-lyase (PAL) activity were significantly increased by soil salinity, confirming that the accumulation of chlorogenic acids in leaves was a result of stimulation of their synthesis under salinity stress. Soil salinity also led to elevated chlorogenic acid concentrations in honeysuckle flower buds, with significant increases in total chlorogenic acids concentration of 22.42 and 25.14% in May 2014 and 2015, respectively. Consistent with biomass reduction, the absolute amounts of chlorogenic acid per plant declined in flower buds of plants exposed to elevated soil salinity, with no significant change in PAL activity. Thus, salinity-induced chlorogenic acid accumulation in flower buds depended on an amplification effect of growth reduction. In conclusion, salinity stress improved the medicinal quality of honeysuckle by promoting accumulation of chlorogenic acids, however, the mechanisms underlying this process were not consistent in flower buds and leaves. Honeysuckle appears to be a promising plant for cultivation in saline land. Our study deepens knowledge of medicinal plant ecology and may provide a guide for developing saline agriculture. PMID:27803710
Yan, Kun; Cui, Mingxing; Zhao, Shijie; Chen, Xiaobing; Tang, Xiaoli
2016-01-01
Honeysuckle ( Lonicera japonica Thunb.) is a traditional medicinal plant in China that is particularly rich in chlorogenic acids, which are phenolic compounds with various medicinal properties. This study aimed to examine the effects of salinity stress on accumulation of chlorogenic acids in honeysuckle, through hydroponic experiments and field trials, and to examine the mechanisms underlying the effects. NaCl stress stimulated the transcription of genes encoding key enzymes in the synthesis of chlorogenic acids in leaves; accordingly, the concentrations of chlorogenic acids in leaves were significantly increased under NaCl stress, as was antioxidant activity. Specifically, the total concentration of leaf chlorogenic acids was increased by 145.74 and 50.34% after 30 days of 150 and 300 mM NaCl stress, respectively. Similarly, the concentrations of chlorogenic acids were higher in the leaves of plants in saline, compared with non-saline, plots, with increases in total concentrations of chlorogenic acids of 56.05 and 105.29% in October 2014 and 2015, respectively. Despite leaf biomass reduction, absolute amounts of chlorogenic acids per plant and phenylalanine ammonia-lyase (PAL) activity were significantly increased by soil salinity, confirming that the accumulation of chlorogenic acids in leaves was a result of stimulation of their synthesis under salinity stress. Soil salinity also led to elevated chlorogenic acid concentrations in honeysuckle flower buds, with significant increases in total chlorogenic acids concentration of 22.42 and 25.14% in May 2014 and 2015, respectively. Consistent with biomass reduction, the absolute amounts of chlorogenic acid per plant declined in flower buds of plants exposed to elevated soil salinity, with no significant change in PAL activity. Thus, salinity-induced chlorogenic acid accumulation in flower buds depended on an amplification effect of growth reduction. In conclusion, salinity stress improved the medicinal quality of honeysuckle by promoting accumulation of chlorogenic acids, however, the mechanisms underlying this process were not consistent in flower buds and leaves. Honeysuckle appears to be a promising plant for cultivation in saline land. Our study deepens knowledge of medicinal plant ecology and may provide a guide for developing saline agriculture.
Atrial natriuretic factor increases vascular permeability
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lockette, W.; Brennaman, B.
An increase in central blood volume in microgravity may result in increased plasma levels of atrial natriuretic factor (ANF). Since elevations in plasma ANF are found in clinical syndromes associated with edema, and since space motion sickness induced by microgravity is associated with an increase in central blood volume and facial edema, we determined whether ANF increases capillary permeability to plasma protein. Conscious, bilaterally nephrectomized male rats were infused with either saline, ANF + saline, or hexamethonium + saline over 2 h following bolus injections of 125I-albumin and 14C-dextran of similar molecular size. Blood pressure was monitored and serial determinationsmore » of hematocrits were made. Animals infused with 1.0 micrograms.kg-1.min-1 ANF had significantly higher hematocrits than animals infused with saline vehicle. Infusion of ANF increased the extravasation of 125I-albumin, but not 14C-dextran from the intravascular compartment. ANF also induced a depressor response in rats, but the change in blood pressure did not account for changes in capillary permeability to albumin; similar depressor responses induced by hexamethonium were not accompanied by increased extravasation of albumin from the intravascular compartment. ANF may decrease plasma volume by increasing permeability to albumin, and this effect of ANF may account for some of the signs and symptoms of space motion sickness.« less
Jiang, Caifu; Belfield, Eric J.; Cao, Yi; Smith, J. Andrew C.; Harberd, Nicholas P.
2013-01-01
High soil Na concentrations damage plants by increasing cellular Na accumulation and K loss. Excess soil Na stimulates ethylene-induced soil-salinity tolerance, the mechanism of which we here define via characterization of an Arabidopsis thaliana mutant displaying transpiration-dependent soil-salinity tolerance. This phenotype is conferred by a loss-of-function allele of ETHYLENE OVERPRODUCER1 (ETO1; mutant alleles of which cause increased production of ethylene). We show that lack of ETO1 function confers soil-salinity tolerance through improved shoot Na/K homeostasis, effected via the ETHYLENE RESISTANT1–CONSTITUTIVE TRIPLE RESPONSE1 ethylene signaling pathway. Under transpiring conditions, lack of ETO1 function reduces root Na influx and both stelar and xylem sap Na concentrations, thereby restricting root-to-shoot delivery of Na. These effects are associated with increased accumulation of RESPIRATORY BURST OXIDASE HOMOLOG F (RBOHF)–dependent reactive oxygen species in the root stele. Additionally, lack of ETO1 function leads to significant enhancement of tissue K status by an RBOHF-independent mechanism associated with elevated HIGH-AFFINITY K+ TRANSPORTER5 transcript levels. We conclude that ethylene promotes soil-salinity tolerance via improved Na/K homeostasis mediated by RBOHF-dependent regulation of Na accumulation and RBOHF-independent regulation of K accumulation. PMID:24064768
Eddy covarianace measurements in a hyper-arid and hyper-saline mangroves ecosystem
NASA Astrophysics Data System (ADS)
Perri, S.; Marpu, P.; Molini, A.; Armstrong, P.
2017-12-01
The natural environment of mangroves provides a number of ecosystem services for improving water quality, supporting healthy fisheries, and protecting the coasts. Also, their carbon storage is larger than any other forest type. Several authors have recognized the importance of mangroves in global carbon cycles. However, energy, water and carbon exchanges between ecosystem and atmosphere are still not completely understood. Eddy covariance measurements are extremely valuable to understand the role of the unique stressors of costal ecosystems in gas exchange. In particular, periodic flooding and elevated soil pore water salinity influence land-atmosphere interactions. Despites the importance of flux measurements in mangroves forests, such in-situ observations are extremely rare. Our research team set up an eddy covariance tower in the Mangrove National Park of Abu Dhabi, UAE. The study site (24.4509° N, 54.4288° E) is located in a dwarf Avicennia marina ecosystem experiencing extremely high temperatures and salinity. CO2 and H2O exchanges are estimated and related to water level and salinity measurements. This unique dataset will shed some light on the net ecosystem exchange (NEE) of carbon dioxide, on energy fluxes and on evapotranspiration rates for a halophyte ecosystem under severe salt-stress and high temperature.
Biofilm formation and granule properties in anaerobic digestion at high salinity.
Gagliano, M C; Ismail, S B; Stams, A J M; Plugge, C M; Temmink, H; Van Lier, J B
2017-09-15
For the anaerobic biological treatment of saline wastewater, Anaerobic Digestion (AD) is currently a possibility, even though elevated salt concentrations can be a major obstacle. Anaerobic consortia and especially methanogenic archaea are very sensitive to fluctuations in salinity. When working with Upflow Sludge Blanket Reactor (UASB) technology, in which the microorganisms are aggregated and retained in the system as a granular biofilm, high sodium concentration negatively affects aggregation and consequently process performances. In this research, we analysed the structure of the biofilm and granules formed during the anaerobic treatment of high salinity (at 10 and 20 g/L of sodium) synthetic wastewater at lab scale. The acclimated inoculum was able to accomplish high rates of organics removal at all the salinity levels tested. 16S rRNA gene clonal analysis and Fluorescence In Situ Hybridization (FISH) analyses identified the acetoclastic Methanosaeta harundinacea as the key player involved acetate degradation and microbial attachment/granulation. When additional calcium (1 g/L) was added to overcome the negative effect of sodium on microbial aggregation, during the biofilm formation process microbial attachment and acetate degradation decreased. The same result was observed on granules formation: while calcium had a positive effect on granules strength when added to UASB reactors, Methanosaeta filaments were not present and the degradation of the partially acidified substrate was negatively influenced. This research demonstrated the possibility to get granulation at high salinity, bringing to the forefront the importance of a selection towards Methanosaeta cells growing in filamentous form to obtain strong and healthy granules. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.
Suic, S P; Sikić, J
2001-01-01
We measured the tamponading effect of silicone oil, saline and air after vitrectomy, on intraocular pressure and aqueous humor outflow in 85 patients with highly proliferative retina and vitreous changes. Silicone oil as retinal tamponading agent after vitrectomy was used in 45 patients, and saline or air in 39 patients. The mean intraocular pressure measured at one month after treatment was greatly elevated in patients with silicone oil tamponade as compared to those with saline or air tamponade. At 6 and 12 months examinations, mean intraocular pressures were compared in these two groups of patients. Gonioscopy revealed silicone oil emulsification and presence of emulsified bubbles in the anterior chamber in 22.22% of patients, and narrowing of the chamber angle in several patients with silicone oil tamponade. Intraocular pressure elevation following vitrectomy with silicone oil tamponade was found to be of transient rather than permanent nature, since it regressed after silicone oil removal. This transient elevation was due to silicone oil tendency to emulsify. Silicone oil bubbles changed the morphology of the anterior chamber angle and fine trabecular structures by creating a barrier to aqueous humor outflow.
Assessing Sea Level Rise Impacts on the Surficial Aquifer in the Kennedy Space Center Region
NASA Astrophysics Data System (ADS)
Xiao, H.; Wang, D.; Hagen, S. C.; Medeiros, S. C.; Warnock, A. M.; Hall, C. R.
2014-12-01
Global sea level rise in the past century due to climate change has been seen at an average rate of approximately 1.7-2.2 mm per year, with an increasing rate over the next century. The increasing SLR rate poses a severe threat to the low-lying land surface and the shallow groundwater system in the Kennedy Space Center in Florida, resulting in saltwater intrusion and groundwater induced flooding. A three-dimensional groundwater flow and salinity transport model is implemented to investigate and evaluate the extent of floods due to rising water table as well as saltwater intrusion. The SEAWAT model is chosen to solve the variable-density groundwater flow and salinity transport governing equations and simulate the regional-scale spatial and temporal evolution of groundwater level and chloride concentration. The horizontal resolution of the model is 50 m, and the vertical domain includes both the Surficial Aquifer and the Floridan Aquifer. The numerical model is calibrated based on the observed hydraulic head and chloride concentration. The potential impacts of sea level rise on saltwater intrusion and groundwater induced flooding are assessed under various sea level rise scenarios. Based on the simulation results, the potential landward movement of saltwater and freshwater fringe is projected. The existing water supply wells are examined overlaid with the projected salinity distribution map. The projected Surficial Aquifer water tables are overlaid with data of high resolution land surface elevation, land use and land cover, and infrastructure to assess the potential impacts of sea level rise. This study provides useful tools for decision making on ecosystem management, water supply planning, and facility management.
Use of sediment amendments to rehabilitate sinking coastal swamp forests in Louisiana
Middleton, Beth A.; Jiang, Ming
2013-01-01
Coastal wetlands are losing elevation worldwide, so that techniques to increase elevation such as sediment amendment might benefit these wetlands. This study examined the potential of sediment amendment to raise elevation and support the production and regeneration of vegetation in coastal forests in Louisiana. Before sediment amendment, the vegetation did not differ in these Taxodium distichum–Nyssa aquatica forests with respect to herbaceous and tree seedling composition, and sapling and tree characteristics. After the application of sediment in January 2007, sediment-amended swamps had higher elevations and salinity levels than natural swamps. The layer of sediment applied to Treasure Island in Jean Lafitte National Historic Park and Preserve was relatively deep (sediment depth at Site One and Site Two: 0.89 and 0.69 m, respectively, six months after application), and may have exceeded an optimal threshold. Sediment-amended swamp with the highest elevation had some tree mortality and little tree growth of T. distichum. Also, sediment-amended swamp had higher root biomasses of ruderal species, and lower species richness and cover of herbaceous species. Nevertheless, during controlled water releases during an oil spill emergency in 2010, both sediment-amended and reference forest had higher production levels than in other years. While sediment amendment is a compelling management alternative for sinking coastal wetlands, optimal thresholds were not determined for these T. distichum–N. aquatica swamps.
Hyperthyroidism-associated hypercalcemic crisis: A case report and review of the literature.
Chen, Ke; Xie, Yanhong; Zhao, Liling; Mo, Zhaohui
2017-01-01
Hyperthyroidism is one of the major clinical causes of hypercalcaemia, however, hyperthyroidism-related hypercalcemic crisis is rare, only 1 case have been reported. The potential mechanisms are still not too clear. It may be related that thyroid hormone stimulate bone turnover, elevate serum calcium, increase urinary and fecal calcium excretion. A 58-year-old female patient was found to have Graves' disease, a marked elevated serum calcium level (adjusted serum calcium: 3.74 mmol/L), and reduced parathyroid hormone level. She was diagnosed as hyperthyroidism-associated hypercalcemic crisis. Treatment with methimazole to correct the hyperthyroidism and treatment of the patient's hypercalcaemia was achieved by physiological saline, salmon calcitonin and furosemide. After treatment for hypercalcaemia and hyperthyroidism, her symptoms and serum calcium levels quickly returned to normal. hyperthyroid-associated hypercalcaemia crisis is rare, however, the diagnosis should pay attention to screening for other diseases caused by hypercalcemia. Timely treatment of hypercalcaemia is a critical step for rapidly control of symptoms, and treatment of hyperthyroidism is beneficial to relief the symptoms and maintain the blood calcium level.
NASA Astrophysics Data System (ADS)
Baharuddin, M. F. T.; Masirin, M. I. M.; Hazreek, Z. A. M.; Azman, M. A. A.; Madun, A.
2018-04-01
Groundwater suitability for water supply and agriculture in an island coastal area may easily be influenced by seawater intrusion. The aim of this study was to investigate seawater intrusion to the suitability of the groundwater for water supply and oil palm cultivation on Carey Island in Malaysia. This is the first study that used integrated method of geo-electrical resistivity and hydrogeochemical methods to investigate seawater intrusion to the suitability of groundwater for water supply and oil palm cultivation at two different surface elevation and land cover. The relationship between earth resistivity, total dissolved solids and earth conductivity was derived with water type classifications and crop suitability classification according to salinity, used to identify water types and also oil palm tolerance to salinity. Results from the contour resistivity and conductivity maps showed that the area facing severe coastal erosion (east area) exhibited unsuitable groundwater condition for water supply and oil palm at the unconfined aquifer thickness of 7.8 m and 14.1 m, respectively. Comparing to the area that are still intact with mangrove (west area), at the same depth, groundwater condition exhibits suitable usage for both socioeconomic activities. Different characteristics of surface elevation and land cover are paramount factors influencing saltwater distribution at the west and east area. By the end of the twenty-first century there will no longer be suitable water for supply and oil palm plantation based on the local sea-level rise prediction and Ghyben–Herzberg assumption (sharp interface), focusing on the severe erosion area of the study site.
Suzuki, Shunichi; Arima, Taro; Kitagawa, Yoshimasa; Svensson, Peter; Castrillon, Eduardo
2017-12-01
This study aimed to investigate the effect of glutamate-evoked masseter muscle pain on intramuscular oxygenation during rest and sustained elevated muscle activity (SEMA). Seventeen healthy individuals participated in two sessions in which they were injected with glutamate and saline in random order. Each session was divided into three, 10-min periods. During the first (period 1) and the last (period 3) 10-min periods, participants performed five intercalated 1-min bouts of masseter SEMA with 1-min periods of 'rest'. At onset of the second 10-min period, glutamate (0.5 ml, 1 M; Ajinomoto, Tokyo, Japan) or isotonic saline (0.5 ml; 0.9%) was injected into the masseter muscle and the participants kept the muscle relaxed in a resting position for 10 min (period 2). The hemodynamic characteristics of the masseter muscle were recorded simultaneously during the experiment by a laser blood-oxygenation monitor. The results demonstrated that glutamate injections caused significant levels of self-reported pain in the masseter muscle; however, this nociceptive input did not have robust effects on intramuscular oxygenation during rest or SEMA tasks. Interestingly, these findings suggest an uncoupling between acute nociceptive activity and hemodynamic parameters in both resting and low-level active jaw muscles. Further studies are needed to explore the pathophysiological significance of blood-flow changes for persistent jaw-muscle pain conditions. © 2017 Eur J Oral Sci.
Learned helplessness and responses to nerve blocks in chronic low back pain patients.
Chapman, S L; Brena, S F
1982-01-01
In a double-blind study, 67 chronic low back pain patients received 4 lumbar sympathetic nerve blocks, two given with bupivacaine and two given with saline. It was hypothesized that patients showing evidence of 'learned helplessness,' as measured by dependence on habit-forming medications for the pain, low activity levels, and elevated MMPI scores on Hypochondriasis, Depression and Hysteria would show the least reduction in subjective pain intensity following injections with both bupivacaine and saline. It also was hypothesized that placebo responses would be greatest in patients who had a high educational level, were divorced, and had no pending disability claims. Responses 30 min following nerve blocks failed to correlate with these variables. However, decreases in subjective pain intensity 24 h following both types of nerve blocks were greater in patients who showed low levels of pain behavior, who were divorced, and who had no pending disability claims. Decreased pain 24 h following saline injections was significantly related to low scores on the Lie, Defensiveness, Hypochondriasis, and Hysteria scales of the MMPI and to reduced subjective pain intensity following a 6 week comprehensive outpatient pain rehabilitation program. It was concluded that chronic pain patients who are fixed in their focus on pain, high in pain-related behaviors, and low in responsibilities are less likely to respond favorably to nerve blocks and that medical treatment for them needs to be paired with therapies designed to reduce their helplessness.
Li, Min; Chen, Tao; Chen, Shu-da; Cai, Jing; Hu, Ying-Hong
2015-05-01
The purpose of this meta-analysis was to compare the effectiveness of mannitol and hypertonic saline for reducing intracranial pressure (ICP) after traumatic brain injury (TBI).PubMed, Cochrane, Embase, and ISI Web of Knowledge databases were searched until July 3, 2014 using the terms intracranial hypertension, mannitol, and hypertonic saline. Randomized controlled trials and 2-arm prospective studies in which elevated ICP was present after TBI treated with mannitol or hypertonic saline were included. The primary outcome was the change of ICP from baseline to termination of the infusion, while the secondary outcomes were change from baseline to 30, 60, and 120 minutes after terminating the infusion and change of osmolarity from baseline to termination.A total 7 studies with 169 patients were included. The mean age of patients receiving mannitol ranged from 30.8 to 47 years, and for patients receiving hypertonic saline ranged from 35 to 47 years. A pooled difference in means = -1.69 (95% confidence interval [CI]: -2.95 to -0.44, P = 0.008) indicated that hypertonic saline reduced ICP more effectively than mannitol when compared from the baseline value to the last measurement after treatment. At 30 minutes after intervention, there was no difference in the mean ICP change between the groups, whereas at 60 minutes after intervention (pooled difference in means = -2.58, 95% CI: -4.37 to -0.80, P = .005) and 120 min after intervention (pooled difference in means = -4.04, 95% CI: -6.75 to -1.32, P = .004) hypertonic saline resulted in a significantly greater decrease in ICP. The pooled difference in means = 1.84 (95% CI: -1.64 to 5.31, P = .301) indicated no difference in serum osmolarity between patients treated with hypertonic saline or mannitol.Hypertonic saline is more effective than mannitol for reducing ICP in cases of TBI.
Villar, H V; Fender, H R; Rayford, P L; Bloom, S R; Ramus, N I; Thompson, J C
1976-01-01
Five dogs prepared with Heidenhain pouches received infusions of saline, GIP and VIP before and after a standard meat meal. Blood samples were obtained under basal conditions and at subsequent intervals for measurement of gastrin, insulin, GIP and VIP by radioimmunoassay. GIP and VIP infusions had no effect on basal levels of gastrin. GIP and VIP (in common with secretin and glucagon) were found to suppress food-stimulated release of gastrin and gastrin-stimulated acid secretion from the Heidenhain pouch. Insulin levels were significantly elevated during GIP and VIP infusions. Food released GIP (and perhaps VIP. PMID:938120
Taylor, Michael A; Yu, Jong W; Howell, Thomas L; Jones, Stephen H
2018-04-01
Vibrio parahaemolyticus is the leading cause of seafood-borne human infections in the United States, and many of these illnesses are associated with consumption of raw molluscan shellfish. V. parahaemolyticus levels in shellfish vary temporally and spatially with environmental conditions in and around production areas. The objective of this study was to study the potential for reducing levels of V. parahaemolyticus in live oysters by relaying them during higher-risk warm weather to a site with elevated salinity and consistently low V. parahaemolyticus levels. The effectiveness of relaying was assessed by analyzing oyster samples collected on days 0, 2, 7, 10, and 14 for V. parahaemolyticus levels using a three-tube most-probable-number enrichment method in conjunction with genetic marker-based quantitative PCR. The salinity at the relay site was always higher than the salinity at the harvest site, with the difference between the two sites ranging from 3.4 to 19.1 ppt (average, 12 ppt) during 2011 to 2014. Oysters relayed during June, July, and August in 2011 and 2012 showed consistently reduced V. parahaemolyticus levels after 14 days, whereas relaying was less successful and V. parahaemolyticus populations changed to include trh-positive strains during 2013. When effective, relay required at least 10 days to reduce V. parahaemolyticus levels. A sample of oysters collected in August 2012, which was temperature abused to increase initial V. parahaemolyticus levels, showed a 4.5-log decrease in V. parahaemolyticus levels after 14 days of relay. These results suggest that relaying oysters to reduce V. parahaemolyticus levels holds promise, but that both microbial community and environmental conditions at relay sites can affect relay success. Further investigation to discover key factors that affect V. parahaemolyticus levels in relayed oysters may aid in developing a consistent approach for reducing V. parahaemolyticus in oysters to eliminate the risk of illness for oyster consumers.
NASA Astrophysics Data System (ADS)
Larsen, D.; Paul, J.
2017-12-01
Groundwater salinization is occurring in the Mississippi River Valley Alluvial (MRVA) aquifer in southeastern Arkansas (SE AR). Water samples from the MRVA aquifer in Chicot and Desha counties have yielded elevated Cl-concentrations with some as high as 1,639 mg/L. Considering that the MRVA aquifer is the principle source of irrigation water for the agricultural economy of SE AR, salinization needs to be addressed to ensure the sustainability of crop, groundwater, and soil resources in the area. The origin of elevated salinity in MRVA aquifer was investigated using spatial and factor analysis of historical water quality data, and sampling and tracer analysis of groundwater from irrigation, municipal, and flowing industrial wells in SE AR. Spatial analysis of Cl- data in relation to soil type, geomorphic features and sand-blow density indicate that the Cl- anomalies are more closely related to the sand-blow density than soil data, suggesting an underlying tectonic control for the distribution of salinity. Factor analysis of historical geochemical data from the MRVA and underlying Sparta aquifer shows dilute and saline groups, with saline groups weighted positively with Cl- or Na+ and Cl-. Tracer data suggest a component of evaporatively evolved crustal water of pre-modern age has mixed with younger, fresher meteoric sources in SE AR to create the saline conditions in the MRVA aquifer. Stable hydrogen and oxygen values of waters sampled from the Tertiary Sparta and MRVA aquifers deviate from the global and local meteoric water lines along an evaporative trend (slope=4.4) and mixing line with Eocene Wilcox Group groundwaters. Ca2+ and Cl- contents vary with Br- along mixing trends between dilute MRVA water and Jurassic Smackover Formation pore fluids in southern AR. Increasing Cl- content with C-14 age in MRVA aquifer groundwater suggests that the older waters are more saline. Helium isotope ratios decrease with He gas content for more saline water, consistent with crustal He production. Our model for the system invokes upward migration of Smackover pore fluids and other deep groundwater along faults in SE AR, whereby the saline fluids intrude and mix with dilute water in the MRVA aquifer to create saline conditions. Other processes, such as infiltration of saline irrigation runoff, may also be contributing to the problem.
Structure and composition of oligohaline marsh plant communities exposed to salinity pulses
Howard, R.J.; Mendelssohn, I.A.
2000-01-01
The response of two oligohaline marsh macrophyte communities to pulses of increased salinity was studied over a single growing season in a greenhouse experiment. The plant communities were allowed a recovery period in freshwater following the pulse events. The experimental treatments included: (1) salinity influx rate (rate of salinity increase from 0 to 12 gl-1); (2) duration of exposure to elevated salinity; and (3) water depth. The communities both included Sagittaria lancifolia L.; the codominant species were Eleocharis palustris (L.) Roemer and J.A. Schultes in community 1 and Schoenoplectus americanus (Pers.) Volk. ex Schinz and R. Keller in community 2. Effects of the treatments on sediment chemical characteristics (salinity, pH, redox potential, and sulfide and ammonium concentrations) and plant community attributes (aboveground and belowground biomass, stem density, leaf tissue nutrients, and species richness) were examined. The treatment effects often interacted to influence sediment and plant communities characteristics following recovery in fresh water. Salinity influx rate per se, however, had little effect on the abiotic or biotic response variables; significant influx effects were found when the 0 gl-1 (zero influx) treatment was compared to the 12 gl-1 treatments, regardless of the rate salinity was raised. A salinity level of 12 gl-1 had negative effects on plant community structure and composition; these effects were usually associated with 3 months of salinity exposure. Water depth often interacted with exposure duration, but increased water depth did independently decrease the values of some community response measures. Community 1 was affected more than community 2 in the most extreme salinity treatment (3 months exposure/15-cm water depth). Although species richness in both communities was reduced, structural changes were more dramatic in community 1. Biomass and stem density were reduced in community 1 overall and in both dominant species. Structural changes in community 2 consisted of reduced biomass and stem density in the community overall and in S. lancifolia; S. americanus was not affected by salinity. In this most extreme treatment, community 2 tended to change to a monospecific S. americanus stand while community 1 was reduced to a few surviving stems of secondary species. Our results suggest that vegetation recovery or establishment of new species following a temporary increase in soil water salinity will vary with exposure duration and water depth. (C) 2000 Elsevier Science B.V.
Ribeiro, A; Ferraz-de-Paula, V; Pinheiro, M L; Palermo-Neto, J
2009-06-01
The endocannabinoid system is involved in the control of many physiological functions, including the control of emotional states. In rodents, previous exposure to an open field increases the anxiety-like behavior in the elevated plus-maze. Anxiolytic-like effects of pharmacological compounds that increase endocannabinoid levels have been well documented. However, these effects are more evident in animals with high anxiety levels. Several studies have described characteristic inverted U-shaped dose-response effects of drugs that modulate the endocannabinoid levels. However, there are no studies showing the effects of different doses of exogenous anandamide, an endocannabinoid, in animal models of anxiety. Thus, in the present study, we determined the dose-response effects of exogenous anandamide at doses of 0.01, 0.1, and 1.0 mg/kg in C57BL/6 mice (N = 10/group) sequentially submitted to the open field and elevated plus-maze. Anandamide was diluted in 0.9% saline, ethyl alcohol, Emulphor (18:1:1) and administered ip (0.1 mL/10 g body weight); control animals received the same volume of anandamide vehicle. Anandamide at the dose of 0.1 mg/kg (but not of 0.01 or 1 mg/kg) increased (P < 0.05) the time spent and the distance covered in the central zone of the open field, as well as the exploration of the open arms of the elevated plus-maze. Thus, exogenous anandamide, like pharmacological compounds that increase endocannabinoid levels, promoted a characteristic inverted U-shaped dose-response effect in animal models of anxiety. Furthermore, anandamide (0.1 mg/kg) induced an anxiolytic-like effect in the elevated plus-maze (P < 0.05) after exposing the animals to the open field test.
NASA Astrophysics Data System (ADS)
Saruwatari, Kazuko; Satoh, Manami; Harada, Naomi; Suzuki, Iwane; Shiraiwa, Yoshihiro
2016-05-01
Strains of the coccolithophore Emiliania huxleyi (Haptophyta) collected from the subarctic North Pacific and Arctic oceans in 2010 were established as clone cultures and have been maintained in the laboratory at 15 °C and 32 ‰ salinity. To study the physiological responses of coccolith formation to changes in temperature and salinity, growth experiments and morphometric investigations were performed on two strains, namely MR57N isolated from the northern Bering Sea and MR70N at the Chukchi Sea. This is the first report of a detailed morphometric and morphological investigation of Arctic Ocean coccolithophore strains. The specific growth rates at the logarithmic growth phases in both strains markedly increased as temperature was elevated from 5 to 20 °C, although coccolith productivity (estimated as the percentage of calcified cells) was similar at 10-20 % at all temperatures. On the other hand, the specific growth rate of MR70N was affected less by changes in salinity in the range 26-35 ‰, but the proportion of calcified cells decreased at high and low salinities. According to scanning electron microscopy (SEM) observations, coccolith morphotypes can be categorized into Type B/C on the basis of their biometrical parameters. The central area elements of coccoliths varied from thin lath type to well-calcified lath type when temperature was increased or salinity was decreased, and coccolith size decreased simultaneously. Coccolithophore cell size also decreased with increasing temperature, although the variation in cell size was slightly greater at the lower salinity level. This indicates that subarctic and arctic coccolithophore strains can survive in a wide range of seawater temperatures and at lower salinities with change in their morphology. Because all coccolith biometric parameters followed the scaling law, the decrease in coccolith size was caused simply by the reduced calcification. Taken together, our results suggest that calcification productivity may be used to predict future oceanic environmental conditions in the polar regions.
CSF and blood oxytocin concentration changes following intranasal delivery in macaque.
Dal Monte, Olga; Noble, Pamela L; Turchi, Janita; Cummins, Alex; Averbeck, Bruno B
2014-01-01
Oxytocin (OT) in the central nervous system (CNS) influences social cognition and behavior, making it a candidate for treating clinical disorders such as schizophrenia and autism. Intranasal administration has been proposed as a possible route of delivery to the CNS for molecules like OT. While intranasal administration of OT influences social cognition and behavior, it is not well established whether this is an effective means for delivering OT to CNS targets. We administered OT or its vehicle (saline) to 15 primates (Macaca mulatta), using either intranasal spray or a nebulizer, and measured OT concentration changes in the cerebral spinal fluid (CSF) and in blood. All subjects received both delivery methods and both drug conditions. Baseline samples of blood and CSF were taken immediately before drug administration. Blood was collected every 10 minutes after administration for 40 minutes and CSF was collected once post-delivery, at the 40 minutes time point. We found that intranasal administration of exogenous OT increased concentrations in both CSF and plasma compared to saline. Both delivery methods resulted in similar elevations of OT concentration in CSF, while the changes in plasma OT concentration were greater after nasal spray compared to nebulizer. In conclusion our study provides evidence that both nebulizer and nasal spray OT administration can elevate CSF OT levels.
Kaur, Navdeep; Dhawan, Manish; Sharma, Isha; Pati, Pratap Kumar
2016-06-10
Salinity stress is a major constrain in the global rice production and hence serious efforts are being undertaken towards deciphering its remedial strategies. The comparative analysis of differential response of salt sensitive and salt tolerant lines is a judicious approach to obtain essential clues towards understanding the acquisition of salinity tolerance in rice plants. However, adaptation to salt stress is a fairly complex process and operates through different mechanisms. Among various mechanisms involved, the reactive oxygen species mediated salinity tolerance is believed to be critical as it evokes cascade of responses related to stress tolerance. In this background, the present paper for the first time evaluates the ROS generating and the scavenging system in tandem in both salt sensitive and salt tolerant cultivars of rice for getting better insight into salinity stress adaptation. Comparative analysis of ROS indicates the higher level of hydrogen peroxide (H2O2) and lower level of superoxide ions (O(2-)) in the salt tolerant as compared to salt sensitive cultivars. Specific activity of ROS generating enzyme, NADPH oxidase was also found to be more in the tolerant cultivars. Further, activities of various enzymes involved in enzymatic and non enzymatic antioxidant defence system were mostly higher in tolerant cultivars. The transcript level analysis of antioxidant enzymes were in alignment with the enzymatic activity. Other stress markers like proline were observed to be higher in tolerant varieties whereas, the level of malondialdehyde (MDA) equivalents and chlorophyll content were estimated to be more in sensitive. The present study showed significant differences in the level of ROS production and antioxidant enzymes activities among sensitive and tolerant cultivars, suggesting their possible role in providing natural salt tolerance to selected cultivars of rice. Our study demonstrates that the cellular machinery for ROS production and scavenging system works in an interdependent manner to offer better salt stress adaptation in rice. The present work further highlights that the elevated level of H2O2 which is considered as a key determinant for conferring salt stress tolerance to rice might have originated through an alternative route of photocatalytic activity of chlorophyll.
[Spatial differentiation and impact factors of Yutian Oasis's soil surface salt based on GWR model].
Yuan, Yu Yun; Wahap, Halik; Guan, Jing Yun; Lu, Long Hui; Zhang, Qin Qin
2016-10-01
In this paper, topsoil salinity data gathered from 24 sampling sites in the Yutian Oasis were used, nine different kinds of environmental variables closely related to soil salinity were selec-ted as influencing factors, then, the spatial distribution characteristics of topsoil salinity and spatial heterogeneity of influencing factors were analyzed by combining the spatial autocorrelation with traditional regression analysis and geographically weighted regression model. Results showed that the topsoil salinity in Yutian Oasis was not of random distribution but had strong spatial dependence, and the spatial autocorrelation index for topsoil salinity was 0.479. Groundwater salinity, groundwater depth, elevation and temperature were the main factors influencing topsoil salt accumulation in arid land oases and they were spatially heterogeneous. The nine selected environmental variables except soil pH had significant influences on topsoil salinity with spatial disparity. GWR model was superior to the OLS model on interpretation and estimation of spatial non-stationary data, also had a remarkable advantage in visualization of modeling parameters.
NASA Astrophysics Data System (ADS)
Gong, Xu; Huang, Xuxiong; Wen, Wen
2018-03-01
Fertilised eggs of the devil stringer ( Inimicus japonicus) were incubated at different salinity levels (21, 25, 29, 33, and 37), and then the hatching performances, morphological parameters, and biochemical composition (protein, lipid and carbohydrate) of the larvae were assayed to determine the influence of salinity on the early development of I. japonicus. The tested salinity levels did not affect the times of hatching or mouth opening for yolk-sac larvae. However, the salinity significantly influenced the hatching and survival rates of open-mouthed larvae, as well as the morphology of yolk-sac larvae. The data indicated that 30.5 to 37.3 and 24.4 to 29.8 were suitable salinity ranges for the survival of embryos and larvae of I. japonicus, respectively. Larvae incubated at a salinity level of 29 had the greatest full lengths, and decreasing yolk volume was positively correlated with the environmental salinity. With increasing salinity, the individual dry weights of newly hatched larvae or open-mouthed larvae decreased significantly. Newly hatched larvae incubated at a salinity level of 29 had the greatest metabolic substrate contents and gross energy levels, while the openmouthed larvae's greatest values occurred at a salinity level of 25. Larvae incubated in the salinity range of 33 to 37 had the lowest nutritional reserves and energy values. Thus, the I. japonicus yolk-sac larvae acclimated more readily to the lower salinity level than the embryos, and higher salinity levels negatively influenced larval growth and development. In conclusion, the environmental salinity level should be maintained at 29-33 during embryogenesis and at 25-29 during early larval development for this species. Our results can be used to provide optimum aquaculture conditions for the early larval development of I. japonicus.
NASA Astrophysics Data System (ADS)
Gong, Xu; Huang, Xuxiong; Wen, Wen
2017-05-01
Fertilised eggs of the devil stringer (Inimicus japonicus) were incubated at different salinity levels (21, 25, 29, 33, and 37), and then the hatching performances, morphological parameters, and biochemical composition (protein, lipid and carbohydrate) of the larvae were assayed to determine the influence of salinity on the early development of I. japonicus. The tested salinity levels did not affect the times of hatching or mouth opening for yolk-sac larvae. However, the salinity significantly influenced the hatching and survival rates of open-mouthed larvae, as well as the morphology of yolk-sac larvae. The data indicated that 30.5 to 37.3 and 24.4 to 29.8 were suitable salinity ranges for the survival of embryos and larvae of I. japonicus, respectively. Larvae incubated at a salinity level of 29 had the greatest full lengths, and decreasing yolk volume was positively correlated with the environmental salinity. With increasing salinity, the individual dry weights of newly hatched larvae or open-mouthed larvae decreased significantly. Newly hatched larvae incubated at a salinity level of 29 had the greatest metabolic substrate contents and gross energy levels, while the openmouthed larvae's greatest values occurred at a salinity level of 25. Larvae incubated in the salinity range of 33 to 37 had the lowest nutritional reserves and energy values. Thus, the I. japonicus yolk-sac larvae acclimated more readily to the lower salinity level than the embryos, and higher salinity levels negatively influenced larval growth and development. In conclusion, the environmental salinity level should be maintained at 29-33 during embryogenesis and at 25-29 during early larval development for this species. Our results can be used to provide optimum aquaculture conditions for the early larval development of I. japonicus.
Beneficial Use of Drilling Waste - A Wetland Restoration Technology
DOE Office of Scientific and Technical Information (OSTI.GOV)
Pioneer Natural Resources
1999-07-01
The results obtained thus far are promising with regard to the low toxicity of restored drill cuttings (particularly the Cameron substrate) with increasing levels of salinity. Water extraction, acid digestion, and interstitial water samples from the restored drill cuttings, as well as redox potential, soil pH and interstitial nitrate/ammonium concentrations, and the photosynthetic response, have been determined for the baseline fresh water condition (June-August 1998), at 9ppt (September-November 1998), at 18ppt (December-February 1998,1999), and at 27ppt (currently underway). Salinities will be brought to full-strength seawater (36ppt) on May 24, 1999. The Cameron drill cuttings are remarkably similar to dredge spoil,more » which is currently being used as a wetland creation substrate. The few elements that were extracted into the interstitial water were primarily cations (Ca, K, Mg) and were not elevated to a level that would pose a threat to wetlands productivity. Swaco drill cuttings remained high in aluminum with concomitant high pH, which likely resulted in limited plant productivity through hindered nutrient uptake.« less
2014-07-01
onto an 8% SDS gel. Proteins were transferred to a polyvinylidene fluoride membrane, blocked in 5% nonfat milk in Tris-buffered saline, probed with...a)marker)of)fibrosis)[3,)4]),)we)assessed)both) protein )and)mRNA)levels)in)fibroblasts)that)received)DNA)from)a) plasmid)containing)a)single)allele...of)a)single)Col3a1%gene.)In)three)independent)experiments,)COL1A1) protein ) was)significantly)elevated)after)48)hours)of)transfection)with)Col3a1Tsk2
Chan, Vera B. S.; Thiyagarajan, Vengatesen; Lu, Xing Wen; Zhang, Tong; Shih, Kaimin
2013-01-01
The majority of marine benthic invertebrates protect themselves from predators by producing calcareous tubes or shells that have remarkable mechanical strength. An elevation of CO2 or a decrease in pH in the environment can reduce intracellular pH at the site of calcification and thus interfere with animal’s ability to accrete CaCO3. In nature, decreased pH in combination with stressors associated with climate change may result in the animal producing severely damaged and mechanically weak tubes. This study investigated how the interaction of environmental drivers affects production of calcareous tubes by the serpulid tubeworm, Hydroides elegans. In a factorial manipulative experiment, we analyzed the effects of pH (8.1 and 7.8), salinity (34 and 27‰), and temperature (23°C and 29°C) on the biomineral composition, ultrastructure and mechanical properties of the tubes. At an elevated temperature of 29°C, the tube calcite/aragonite ratio and Mg/Ca ratio were both increased, the Sr/Ca ratio was decreased, and the amorphous CaCO3 content was reduced. Notably, at elevated temperature with decreased pH and reduced salinity, the constructed tubes had a more compact ultrastructure with enhanced hardness and elasticity compared to decreased pH at ambient temperature. Thus, elevated temperature rescued the decreased pH-induced tube impairments. This indicates that tubeworms are likely to thrive in early subtropical summer climate. In the context of climate change, tubeworms could be resilient to the projected near-future decreased pH or salinity as long as surface seawater temperature rise at least by 4°C. PMID:24265732
Wu, Chi-Shiun; Yang, Wen-Kai; Lee, Tsung-Han; Gomez-Mestre, Ivan; Kam, Yeong-Choy
2014-01-01
Amphibians are highly susceptible to osmotic stress but, nonetheless, some species can adapt locally to withstand moderately high levels of salinity. Maintaining the homeostasis of body fluids by efficient osmoregulation is thus critical for larval survival in saline environments. We studied the role of acclimation in increased physiological tolerance to elevated water salinity in the Indian rice frog (Fejervarya limnocharis) tadpoles exposed to brackish water. We quantified the effects of salinity acclimation on tadpole survival, osmolality, water content, and gill Na⁺ , K⁺ -ATPase (NKA) expression. Tadpoles did not survive over 12 hr if directly transferred to 11 ppt (parts per thousand) whereas tadpoles previously acclimated for 48 hr in 7 ppt survived at least 48 hr. We reared tadpoles in 3 ppt and then we transferred them to one of (a) 3 ppt, (b) 11 ppt, and (c) 7 ppt for 48 hr and then 11 ppt. In the first 6 hr after transfer to 11 ppt, tadpole osmolality sharply increased and tadpole water content decreased. Tadpoles pre-acclimated for 48 hr in 7 ppt were able to maintain lower and more stable osmolality within the first 3 hr after transfer. These tadpoles initially lost water content, but over the next 6 hr gradually regained water and stabilized. In addition, they had a higher relative abundance of NKA proteins than tadpoles in other treatments. Pre-acclimation to 7 ppt for 48 hr was hence sufficient to activate NKA expression, resulting in increased survivorship and reduced dehydration upon later transfer to 11 ppt. J © 2013 Wiley Periodicals, Inc.
Tipsmark, Christian K; Breves, Jason P; Rabeneck, D Brett; Trubitt, Rebecca T; Lerner, Darren T; Grau, E Gordon
2016-09-01
In euryhaline teleosts, reorganization of gill tight junctions during salinity acclimation involves dynamic expression of specific claudin (Cldn) paralogs. We identified four transcripts encoding Cldn tight junction proteins in the tilapia gill transcriptome: cldn10c, cldn10e, cldn28a and cldn30. A tissue distribution experiment found cldn10c and cldn10e expression levels in the gill to be 100-fold higher than any other tissues examined. cldn28a and cldn30 levels in the gill were 10-fold greater than levels in other tissues. Expression of these genes in Mozambique tilapia was examined during acclimation to fresh water (FW), seawater (SW), and in response to hormone treatments. Transfer of tilapia from FW to SW elevated cldn10c and cldn10e, while cldn28a and cldn30 were stimulated following transfer from SW to FW. In hypophysectomized tilapia transferred to FW, pituitary extirpation induced reduced expression of cldn10c, cldn10e and cldn28a; these effects were mitigated equally by either prolactin or cortisol replacement. In vitro experiments with gill filaments showed that cortisol stimulated expression of all four cldns examined, suggesting a direct action of cortisol in situ. Our data indicate that elevated cldn10c and cldn10e expression is important during acclimation of tilapia to SW possibly by conferring ion specific paracellular permeability. On the other hand, expression of cldn28a and cldn30 appears to contribute to reorganization of branchial epithelium during FW acclimation. Hormone treatment experiments showed that particular FW- and SW-induced cldns are controlled by cortisol and prolactin. Copyright © 2016 Elsevier Inc. All rights reserved.
Fingerprinting groundwater salinity sources in the Gulf Coast Aquifer System, USA
NASA Astrophysics Data System (ADS)
Chowdhury, Ali H.; Scanlon, Bridget R.; Reedy, Robert C.; Young, Steve
2018-02-01
Understanding groundwater salinity sources in the Gulf Coast Aquifer System (GCAS) is a critical issue due to depletion of fresh groundwater and concerns for potential seawater intrusion. The study objective was to assess sources of groundwater salinity in the GCAS using ˜1,400 chemical analyses and ˜90 isotopic analyses along nine well transects in the Texas Gulf Coast, USA. Salinity increases from northeast (median total dissolved solids (TDS) 340 mg/L) to southwest (median TDS 1,160 mg/L), which inversely correlates with the precipitation distribution pattern (1,370- 600 mm/yr, respectively). Molar Cl/Br ratios (median 540-600), depleted δ2H and δ18O (-24.7‰, -4.5‰) relative to seawater (Cl/Br ˜655 and δ2H, δ18O 0‰, 0‰, respectively), and elevated 36Cl/Cl ratios (˜100), suggest precipitation enriched with marine aerosols as the dominant salinity source. Mass balance estimates suggest that marine aerosols could adequately explain salt loading over the large expanse of the GCAS. Evapotranspiration enrichment to the southwest is supported by elevated chloride concentrations in soil profiles and higher δ18O. Secondary salinity sources include dissolution of salt domes or upwelling brines from geopressured zones along growth faults, mainly near the coast in the northeast. The regional extent and large quantities of brackish water have the potential to support moderate-sized desalination plants in this location. These results have important implications for groundwater management, suggesting a current lack of regional seawater intrusion and a suitable source of relatively low TDS water for desalination.
Ocean acidification alters temperature and salinity preferences in larval fish.
Pistevos, Jennifer C A; Nagelkerken, Ivan; Rossi, Tullio; Connell, Sean D
2017-02-01
Ocean acidification alters the way in which animals perceive and respond to their world by affecting a variety of senses such as audition, olfaction, vision and pH sensing. Marine species rely on other senses as well, but we know little of how these might be affected by ocean acidification. We tested whether ocean acidification can alter the preference for physicochemical cues used for dispersal between ocean and estuarine environments. We experimentally assessed the behavioural response of a larval fish (Lates calcarifer) to elevated temperature and reduced salinity, including estuarine water of multiple cues for detecting settlement habitat. Larval fish raised under elevated CO 2 concentrations were attracted by warmer water, but temperature had no effect on fish raised in contemporary CO 2 concentrations. In contrast, contemporary larvae were deterred by lower salinity water, where CO 2 -treated fish showed no such response. Natural estuarine water-of higher temperature, lower salinity, and containing estuarine olfactory cues-was only preferred by fish treated under forecasted high CO 2 conditions. We show for the first time that attraction by larval fish towards physicochemical cues can be altered by ocean acidification. Such alterations to perception and evaluation of environmental cues during the critical process of dispersal can potentially have implications for ensuing recruitment and population replenishment. Our study not only shows that freshwater species that spend part of their life cycle in the ocean might also be affected by ocean acidification, but that behavioural responses towards key physicochemical cues can also be negated through elevated CO 2 from human emissions.
Potential effects of elevated atmospheric carbon dioxide (CO2) on coastal wetlands
McKee, Karen
2006-01-01
Carbon dioxide (CO2) concentration in the atmosphere has steadily increased from 280 parts per million (ppm) in preindustrial times to 381 ppm today and is predicted by some models to double within the next century. Some of the important pathways whereby changes in atmospheric CO2 may impact coastal wetlands include changes in temperature, rainfall, and hurricane intensity (fig. 1). Increases in CO2 can contribute to global warming, which may (1) accelerate sea-level rise through melting of polar ice fields and steric expansion of oceans, (2) alter rainfall patterns and salinity regimes, and (3) change the intensity and frequency of tropical storms and hurricanes. Sea-level rise combined with changes in storm activity may affect erosion and sedimentation rates and patterns in coastal wetlands and maintenance of soil elevations.Feedback loops between plant growth and hydroedaphic conditions also contribute to maintenance of marsh elevations through accumulation of organic matter. Although increasing CO2 concentration may contribute to global warming and climate changes, it may also have a direct impact on plant growth and development by stimulating photosynthesis or improving water use efficiency. Scientists with the U.S. Geological Survey are examining responses of wetland plants to elevated CO2 concentration and other factors. This research will lead to a better understanding of future changes in marsh species composition, successional rates and patterns, ecological functioning, and vulnerability to sea-level rise and other global change factors.
Pawlosky, Robert J; Kashiwaya, Yoshihiro; Srivastava, Shireesh; King, Michael T; Crutchfield, Calvin; Volkow, Nora; Kunos, George; Li, Ting-Kai; Veech, Richard L
2010-02-01
Previous studies in humans have shown that alcohol consumption decreased the rate of brain glucose utilization. We investigated whether the major metabolite of ethanol, acetate, could account for this observation by providing an alternate to glucose as an energy substrate for brain and the metabolic consequences of that shift. Rats were infused with solutions of sodium acetate, ethanol, or saline containing (13)C-2-glucose as a tracer elevating the blood ethanol (BEC) and blood acetate (BAcC) concentrations. After an hour, blood was sampled and the brains of animals were removed by freeze blowing. Tissue samples were analyzed for the intermediates of glucose metabolism, Krebs' cycle, acyl-coenzyme A (CoA) compounds, and amino acids. Mean peak BEC and BAcC were approximately 25 and 0.8 mM, respectively, in ethanol-infused animals. Peak blood BAcC increased to 12 mM in acetate-infused animals. Both ethanol and acetate infused animals had a lower uptake of (13)C-glucose into the brain compared to controls and the concentration of brain (13)C-glucose-6-phosphate varied inversely with the BAcC. There were higher concentrations of brain malonyl-CoA and somewhat lower levels of free Mg(2+) in ethanol-treated animals compared to saline controls. In acetate-infused animals the concentrations of brain lactate, alpha-ketoglutarate, and fumarate were higher. Moreover, the free cytosolic [NAD(+)]/[NADH] was lower, the free mitochondrial [NAD(+)]/[NADH] and [CoQ]/[CoQH(2)] were oxidized and the DeltaG' of ATP lowered by acetate infusion from -61.4 kJ to -59.9 kJ/mol. Animals with elevated levels of blood ethanol or acetate had decreased (13)C-glucose uptake into the brain. In acetate-infused animals elevated BAcC were associated with a decrease in (13)C-glucose phosphorylation. The co-ordinate decrease in free cytosolic NAD, oxidation of mitochondrial NAD and Q couples and the decrease in DeltaG' of ATP was similar to administration of uncoupling agents indicating that the metabolism of acetate in brain caused the mitochondrial voltage dependent pore to form.
Pawlosky, Robert J.; Kashiwaya, Yoshihiro; Srivastava, Shireesh; King, Michael T.; Crutchfield, Calvin; Volkow, Nora; Kunos, George; Li, Ting-Kai; Veech, Richard L.
2010-01-01
Background Previous studies in humans have shown that alcohol consumption decreased the rate of brain glucose utilization. We investigated whether the major metabolite of ethanol, acetate, could account for this observation by providing an alternate to glucose as an energy substrate for brain and the metabolic consequences of that shift. Methods Rats were infused with solutions of sodium acetate, ethanol, or saline containing 13C-2-glucose as a tracer elevating the blood ethanol (BEC) and blood acetate (BAcC) concentrations. After an hour, blood was sampled and the brains of animals were removed by freeze blowing. Tissue samples were analyzed for the intermediates of glucose metabolism, Krebs’ cycle, acyl-coenzyme A (CoA) compounds, and amino acids. Results Mean peak BEC and BAcC were approximately 25 and 0.8 mM, respectively, in ethanol-infused animals. Peak blood BAcC increased to 12 mM in acetate-infused animals. Both ethanol and acetate infused animals had a lower uptake of 13C-glucose into the brain compared to controls and the concentration of brain 13C-glucose-6-phosphate varied inversely with the BAcC. There were higher concentrations of brain malonyl-CoA and somewhat lower levels of free Mg2+ in ethanol-treated animals compared to saline controls. In acetate-infused animals the concentrations of brain lactate, α-ketoglutarate, and fumarate were higher. Moreover, the free cytosolic [NAD+]/[NADH] was lower, the free mitochondrial [NAD+]/[NADH] and [CoQ]/[CoQH2] were oxidized and the ΔG′ of ATP lowered by acetate infusion from −61.4 kJ to −59.9 kJ/mol. Conclusions Animals with elevated levels of blood ethanol or acetate had decreased 13C-glucose uptake into the brain. In acetate-infused animals elevated BAcC were associated with a decrease in 13C-glucose phosphorylation. The co-ordinate decrease in free cytosolic NAD, oxidation of mitochondrial NAD and Q couples and the decrease in ΔG′ of ATP was similar to administration of uncoupling agents indicating that the metabolism of acetate in brain caused the mitochondrial voltage dependent pore to form. PMID:19951290
It is well known that the competent larvae of many marine invertebrate species can be stimulated to metamorphose by exposing them to elevated concentrations of certain ions, neuroactive substances, and pharmacological agents. In this study we report that larvae of the euryhaline ...
Anti-endotoxic shock effects of cyproheptadine in rats.
Wang, Lizan; Zhang, Qingzhu; Hu, Xiuzhou; Lun, Ning; Wang, Baosheng; Zhu, Fanhe
2002-03-01
To investigate the antagonistic effect and mechanism of the effect of cyproheptadine (Cyp) on endotoxic shock in rats. Endotoxic shock was produced in rats by i.v. injection of lipopolysaccharides (LPS) (5 mg/kg). Tumor necrosis factor (TNF(alpha)) mRNA expression was assessed by Northern blot. Plasma TNF(alpha) content was measured by radioimmunoassay. Plasma superoxide dismutase (SOD) activity and malondialdehyde (MDA) content were measured. The intracellular free calcium concentration ([Ca(2+)](i)) in single endothelial cells was determined by laser scanning confocal microscopy (LSCM). Cyp 5 mg/kg injected immediately after i.v. LPS raised the mean arterial blood pressure (MABP) of shocked rats and improved their 24 h survival rate. Meanwhile, Cyp markedly decreased TNF(alpha) mRNA levels in rat liver (18 +/- 10 vs. LPS + saline 38 +/- 10, P < 0.01) as well as plasma TNF(alpha) content [(7.8 +/- 2.4) microg/L vs. LPS + saline (21.5 +/- 3.2) microg/L, P < 0.01)]. It enhanced plasma SOD activity [(1037.2 +/- 112.8) NU/L vs LPS + saline (615.4 +/- 92.6) NU/L, P < 0.01], reduced the MDA content [(5.2 +/- 1.1) micromol/L vs. LPS + saline (9.8 +/- 1.5) micromol/L, P < 0.01], and inhibited TNF(alpha)-induced [Ca(2+)](i) elevation. Cyp exerts an anti-endotoxic shock effect by inhibiting TNF(alpha) gene expression, enhancing SOD activity, reducing lipid peroxidation, and preventing [Ca(2+)](i) overload.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wang, Taiping; Yang, Zhaoqing; Khangaonkar, Tarang
2010-04-22
In this study, a hydrodynamic model based on the unstructured-grid finite volume coastal ocean model (FVCOM) was developed for Bellingham Bay, Washington. The model simulates water surface elevation, velocity, temperature, and salinity in a three-dimensional domain that covers the entire Bellingham Bay and adjacent water bodies, including Lummi Bay, Samish Bay, Padilla Bay, and Rosario Strait. The model was developed using Pacific Northwest National Laboratory’s high-resolution Puget Sound and Northwest Straits circulation and transport model. A sub-model grid for Bellingham Bay and adjacent coastal waters was extracted from the Puget Sound model and refined in Bellingham Bay using bathymetric lightmore » detection and ranging (LIDAR) and river channel cross-section data. The model uses tides, river inflows, and meteorological inputs to predict water surface elevations, currents, salinity, and temperature. A tidal open boundary condition was specified using standard National Oceanic and Atmospheric Administration (NOAA) predictions. Temperature and salinity open boundary conditions were specified based on observed data. Meteorological forcing (wind, solar radiation, and net surface heat flux) was obtained from NOAA real observations and National Center for Environmental Prediction North American Regional Analysis outputs. The model was run in parallel with 48 cores using a time step of 2.5 seconds. It took 18 hours of cpu time to complete 26 days of simulation. The model was calibrated with oceanographic field data for the period of 6/1/2009 to 6/26/2009. These data were collected specifically for the purpose of model development and calibration. They include time series of water-surface elevation, currents, temperature, and salinity as well as temperature and salinity profiles during instrument deployment and retrieval. Comparisons between model predictions and field observations show an overall reasonable agreement in both temporal and spatial scales. Comparisons of root mean square error values for surface elevation, velocity, temperature, and salinity time series are 0.11 m, 0.10 m/s, 1.28oC, and 1.91 ppt, respectively. The model was able to reproduce the salinity and temperature stratifications inside Bellingham Bay. Wetting and drying processes in tidal flats in Bellingham Bay, Samish Bay, and Padilla Bay were also successfully simulated. Both model results and observed data indicated that water surface elevations inside Bellingham Bay are highly correlated to tides. Circulation inside the bay is weak and complex and is affected by various forcing mechanisms, including tides, winds, freshwater inflows, and other local forcing factors. The Bellingham Bay model solution was successfully linked to the NOAA oil spill trajectory simulation model “General NOAA Operational Modeling Environment (GNOME).” Overall, the Bellingham Bay model has been calibrated reasonably well and can be used to provide detailed hydrodynamic information in the bay and adjacent water bodies. While there is room for further improvement with more available data, the calibrated hydrodynamic model provides useful hydrodynamic information in Bellingham Bay and can be used to support sediment transport and water quality modeling as well as assist in the design of nearshore restoration scenarios.« less
Cerebral cortical blood flow maps are reorganized in MAOB-deficient mice
Scremin, Oscar U.; Holschneider, Daniel P.; Chen, Kevin; Li, Mingen G.; Shih, Jean C.
2014-01-01
Cerebral cortical blood flow (CBF) was measured autoradiographically in conscious mice without the monoamine oxidase B (MAOB) gene (KO, n = 11) and the corresponding wild-type animals (WILD, n = 11). Subgroups of animals of each genotype received a continuous intravenous infusion over 30 min of phenylethylamine (PEA), an endogenous substrate of MAOB, (8 nmol g−1 min−1 in normal saline at a volume rate of 0.11 μl g−1 min−1) or saline at the same volume rate. Maps of relative CBF distribution showed predominance of midline motor and sensory area CBF in KO mice over WILD mice that received saline. PEA enhanced CBF in lateral frontal and piriform cortex in both KO and WILD mice. These changes may reflect a differential activation due to chronic and acute PEA elevations on motor and olfactory function, as well as on the anxiogenic effects of this amine. In addition to its effects on regional CBF distribution, PEA decreased CBF globally in KO mice (range −31% to −41% decrease from control levels) with a lesser effect in WILD mice. It is concluded that MAOB may normally regulate CBF distribution and its response to blood PEA. PMID:10095040
Street, J.H.; Knee, K.L.; Grossman, E.E.; Paytan, A.
2008-01-01
Multiple tracers of groundwater input (salinity, Si, 223Ra, 224Ra, and 226Ra) were used together to determine the magnitude, character (meteoric versus seawater), and nutrient contribution associated with submarine groundwater discharge across the leeward shores of the Hawai'ian Islands Maui, Moloka'i, and Hawai'i. Tracer abundances were elevated in the unconfined coastal aquifer and the nearshore zone, decreasing to low levels offshore, indicative of groundwater discharge (near-fresh, brackish, or saline) at all locations. At several sites, we detected evidence of fresh and saline SGD occurring simultaneously. Conservative estimates of SGD fluxes ranged widely, from 0.02-0.65??m3??m- 2 d- 1at the various sites. Groundwater nutrient fluxes of 0.04-40??mmol N m- 2 d- 1 and 0.01-1.6??mmol P m- 2 d- 1 represent a major source of new nutrients to coastal ecosystems along these coasts. Nutrient additions were typically greatest at locations with a substantial meteoric component in groundwater, but the recirculation of seawater through the aquifer may provide a means of transferring terrestrially-derived nutrients to the coastal zone at several sites. ?? 2007 Elsevier B.V. All rights reserved.
Kobryn, H T; Lantzke, R; Bell, R; Admiraal, R
2015-03-01
The installation of deep drains is an engineering approach to remediate land salinised by the influence of shallow groundwater. It is a costly treatment and its economic viability is, in part, dependent on the lateral extent to which the drain increases biological productivity by lowering water tables and soil salinity (referred to as the drains' zone of benefit). Such zones may be determined by assessing the biological productivity response of adjacent vegetation over time. We tested a multi-temporal satellite remote sensing method to analyse temporal and spatial changes in vegetation condition surrounding deep drainage sites at five locations in the Western Australian wheatbelt affected by dryland salinity-Morawa, Pithara, Beacon, Narembeen and Dumbleyung. Vegetation condition as a surrogate for biological productivity was assessed by Normalised Difference Vegetation Index (NDVI) during the peak growing season. Analysis was at the site scale within a 1000 m buffer zone from the drains. There was clear evidence of NDVI increasing with elevation, slope and distance from the drain. After accounting for elevation, slope and distance from the drain, there was a significant increase in NDVI across the five locations after installation of deep drains. Changes in NDVI after drainage were broadly consistent with measured changes at each site in groundwater levels after installation of the deep drains. However, this study assessed the lateral extent of benefit for biological productivity and gave a measure of the area of benefit along the entire length of the drain. The method demonstrated the utility of spring NDVI images for rapid and relatively simple assessment of the change in site condition after implementation of drainage, but approaches for further improvement of the procedure were identified. Copyright © 2014 Elsevier Ltd. All rights reserved.
Cholinergic mechanisms of analgesia produced by physostigmine, morphine and cold water swimming.
Romano, J A; Shih, T M
1983-07-01
This study concerns the cholinergic involvement in three experimental procedures which produce analgesia. Rats were given one of seven treatments: saline (1.0 ml/kg, i.p.); morphine sulfate (3.5, 6.0 or 9.0 mg/kg, i.p.); physostigmine salicylate (0.65 mg/kg, i.p.); warm water swim (3.5 min at 28 degrees C); and cold water swim (3.5 min at 2 degrees C). Each rat was tested on a hot plate (59.1 degrees C) once prior to and 30 min after treatment. Immediately after the last test the rats were killed with focussed microwave radiation. Levels of acetylcholine (ACh) and choline (Ch) in six brain areas (brain stem, cerebral cortex, hippocampus, midbrain, cerebellum and striatum) were analyzed by gas chromatograph-mass spectrometer. Morphine (9.0 mg/kg), physostigmine and cold water swimming caused significant analgesia. Morphine elevated the levels of ACh in the cerebellum and striatum, cold water swimming--in the cerebellum, striatum and cortex, and physostigmine--in the striatum and hippocampus. Levels of choline were elevated by morphine in the cerebellum, cortex and hippocampus, while cold water swimming elevated levels of choline in the cerebellum, cortex, striatum and hippocampus. Physostigmine did not change levels of choline in any of the brain areas studied. These data suggest that the analgetic effects of morphine or cold water swimming may be mediated by components of the cholinergic system that differ from those involved in the analgetic effects of physostigmine.
NASA Astrophysics Data System (ADS)
Oxmann, J. F.; Schwendenmann, L.
2015-02-01
Mechanisms governing phosphorus (P) speciation in coastal sediments remain largely unknown due to the diversity of coastal environments and poor analytical specificity for P phases. We investigated P speciation across salinity gradients comprising diverse ecosystems in a P-enriched estuary. To determine P load effects on P speciation we compared the high P site with a low P site. Octacalcium phosphate (OCP), authigenic apatite (carbonate fluorapatite, CFAP) and detrital apatite (fluorapatite) were quantitated in addition to Al/Fe-bound P (Al/Fe-P) and Ca-bound P (Ca-P). Gradients in sediment pH strongly affected P fractions across ecosystems and independent of the site-specific total P status. We found a pronounced switch from adsorbed Al/Fe-P to mineral Ca-P with decreasing acidity from land to sea. This switch occurred at near-neutral sediment pH and has possibly been enhanced by redox-driven phosphate desorption from iron oxyhydroxides. The seaward decline in Al/Fe-P was counterbalanced by the precipitation of Ca-P. Correspondingly, two location-dependent accumulation mechanisms occurred at the high P site due to the switch, leading to elevated Al/Fe-P at pH < 6.6 (landward; adsorption) and elevated Ca-P at pH > 6.6 (seaward; precipitation). Enhanced Ca-P precipitation by increased P loads was also evident from disproportional accumulation of metastable Ca-P (Ca-Pmeta) at the high P site. Here, sediments contained on average 6-fold higher Ca-Pmeta levels compared with the low P site, although these sediments contained only 2-fold more total Ca-P than the low P sediments. Phosphorus species distributions indicated that these elevated Ca-Pmeta levels resulted from transformation of fertilizer-derived Al/Fe-P to OCP and CFAP in nearshore areas. Formation of CFAP as well as its precursor, OCP, results in P retention in coastal zones and can thus lead to substantial inorganic P accumulation in response to anthropogenic P input.
On the origin of saline soils at Blackspring Ridge, Alberta, Canada
NASA Astrophysics Data System (ADS)
Stein, Richard; Schwartz, Franklin W.
1990-09-01
Problems of soil salinity occur at Blackspring Ridge, Alberta, in four different settings. The most seriously affected area is at the base of the ridge where salinity appears as severe salt crusting on the surface, salt-tolerant vegetation, and areas of poor or no crop production. Blackspring Ridge is a structural bedrock high that is underlain by Upper Cretaceous sediment of the Horseshoe Canyon Formation. Bedrock is overlain by fluvial, glacial, lacustrine, and aeolian sediment. Piezometric data indicate that groundwater is recharged on and along the upper flanks of Blackspring Ridge and discharges in southern parts of a lacustrine plain that surrounds the ridge. Hydraulic conductivity data, water-level fluctuations, stable isotopes, and hydrochemical data indicate that the fractured near-surface bedrock and overlying thin-drift sediment constitute a zone of active groundwater flow within which salts are generated and transported. Water discharging from this shallow system evaporates and forms saline areas at the base of the ridge. The most seriously affected areas on the lacustrine plain coincide with places where the water table is less than 1.5m from the ground surface. A high water table occurs locally because of the changing topology of geologic units, and lows in the topographic surface that focus groundwater and surface water flows. Some proportion of the shallow groundwater salinized by evaporation is also transported down the flow system where it mixes with unevaporated water. Surface water, from snowmelt and precipitation events, dissolves salt that was deposited at the surface by evaporating groundwater and redistributes the salt to areas of lower elevation.
Nigam, Savita; McCarron, Richard; Arnaud, Francoise
2017-10-01
Hemorrhaged animals have benefited from resuscitation with the hemoglobin-based oxygen carrier (HBOC-201). Co-infusion of nitric oxide (NO) via separate intravascular lines is effective in attenuating HBOC-induced elevation of blood pressure. We tested whether nitroglycerin (NTG) and HBOC-201 can be packaged together as a single drug for resuscitation. Since NTG binds easily to plastics such as polyvinylchloride, we assessed the stability of this combination in oxygen barrier double-layer ethylene-vinyl alcohol/polyolefin bags over a 30-day period. Outcome measures indicative of the stability of HBOC/NTG were reported as changes in levels of hemoglobin (Hb), methemoglobin (MetHb), NTG, and nitrite over time. Individual tightly sealed small aliquots of HBOC/NTG were prepared under nitrogen and analyzed in a timely fashion from 0 to 30 days using hematology instruments, HPLC, FPLC, and chemiluminescence. The level of NTG in the HBOC/NTG mixture was reduced significantly over time whereas it was stable in control mixtures of NTG/saline. The level of total Hb in the HBOC/NTG and HBOC/saline mixtures remained stable over time. MetHb formed and increased to 6% up to day 1 and then slowly decreased in the HBOC/NTG mixture whereas it remained unchanged in the HBOC/saline mixture. Nitrite was produced in the HBOC/NTG group upon mixing, was increased at day 1, and then became undetectable. The reaction between HBOC-201 and NTG occurring upon mixing and developing over time in polyolefin bags makes the long-term storage of this mixed combination inappropriate.
Thompson, Andrew B; Stolyarova, Alexandra; Ying, Zhe; Zhuang, Yumei; Gómez-Pinilla, Fernando; Izquierdo, Alicia
2015-12-01
Exposure to drugs of abuse can produce many neurobiological changes which may lead to increased valuation of rewards and decreased sensitivity to their costs. Many of these behavioral alterations are associated with activity of D2-expressing medium spiny neurons in the striatum. Additionally, Bdnf in the striatum has been shown to play a role in flexible reward-seeking behavior. Given that voluntary aerobic exercise can affect the expression of these proteins in healthy subjects, and that exercise has shown promise as an anti-addictive therapy, we set out to quantify changes in D2 and Bdnf expression in methamphetamine-exposed rats given access to running wheels. Sixty-four rats were treated for two weeks with an escalating dose of methamphetamine or saline, then either sacrificed, housed in standard cages, or given free access to a running wheel for 6 weeks prior to sacrifice. Rats treated with methamphetamine ran significantly greater distances than saline-treated rats, suggesting an augmentation in the reinforcement value of voluntary wheel running. Transcription of Drd2 and Bdnf was assessed via RT-qPCR. Protein expression levels of D2 and phosphorylation of the TrkB receptor were measured via western blot. Drd2 and Bdnf mRNA levels were impacted independently by exercise and methamphetamine, but exposure to methamphetamine prior to the initiation of exercise blocked the exercise-induced changes seen in rats treated with saline. Expression levels of both proteins were elevated immediately after methamphetamine, but returned to baseline after six weeks, regardless of exercise status. Copyright © 2015 Elsevier Ltd. All rights reserved.
Ozgur, Elcin; Sahin, Duygu; Tomruk, Arin; Guler, Goknur; Sepici Dinçel, Aylin; Altan, Nilgun; Seyhan, Nesrin
2015-02-01
The widespread and sustained use of mobile and cordless phones causes unprecedented increase of radiofrequency radiation (RFR). The aim of this experimental study was to investigate the effect of 900 MHz Global System for Mobile Communications (GSM)-modulated RFR (average whole body Specific Absorption Rate (SAR) of 0.4 W/kg, 10 or 20 min daily for consecutive 7 days) to the liver tissue of guinea pigs and the protective effects of antioxidant treatments. Adult male guinea pigs were randomly divided into nine groups as: Group I (sham/saline), Group II (sham/EGCG), Group III (sham/NAC), Group IV (10-min RF-exposure/saline), Group V (20-min RF-exposure/saline), Group VI (10-min RF-exposure/EGCG), Group VII (20-min RF-exposure/EGCG), Group VIII (10-min RF-exposure/NAC), and Group IX (20-min RF-exposure/NAC). Protein oxidation (PCO), advanced oxidation protein products (AOPP) and antioxidant enzyme activities of superoxide dismutase (SOD) were evaluated after the exposure and the treatments with N-acetylcysteine (NAC) and (-)-epigallocatechin-3-gallate (EGCG). Significant decreases in the activities of SOD were observed in the liver of guinea pigs after RFR exposure. Protein damage did not change due to RFR exposure. On the other hand, only NAC treatment induced increased PCO levels, whereas EGCG treatment alone elevated the level of AOPP. Due to antioxidants having pro-oxidant behavior, the well decided doses and treatment timetables of NAC and ECGC are needed.
NASA Astrophysics Data System (ADS)
Geerken, Esmee; de Nooijer, Lennart Jan; van Dijk, Inge; Reichart, Gert-Jan
2018-04-01
Accurate reconstructions of seawater salinity could provide valuable constraints for studying past ocean circulation, the hydrological cycle and sea level change. Controlled growth experiments and field studies have shown the potential of foraminiferal Na / Ca as a direct salinity proxy. Incorporation of minor and trace elements in foraminiferal shell carbonate varies, however, greatly between species and hence extrapolating calibrations to other species needs validation by additional (culturing) studies. Salinity is also known to impact other foraminiferal carbonate-based proxies, such as Mg / Ca for temperature and Sr / Ca for sea water carbonate chemistry. Better constraints on the role of salinity on these proxies will therefore improve their reliability. Using a controlled growth experiment spanning a salinity range of 20 units and analysis of element composition on single chambers using laser ablation-Q-ICP-MS, we show here that Na / Ca correlates positively with salinity in two benthic foraminiferal species (Ammonia tepida and Amphistegina lessonii). The Na / Ca values differ between the two species, with an approximately 2-fold higher Na / Ca in A. lessonii than in A. tepida, coinciding with an offset in their Mg content ( ˜ 35 mmol mol-2 versus ˜ 2.5 mmol mol-1 for A. lessonii and A. tepida, respectively). Despite the offset in average Na / Ca values, the slopes of the Na / Ca-salinity regressions are similar between these two species (0.077 versus 0.064 mmol mol-1 change per salinity unit). In addition, Mg / Ca and Sr / Ca are positively correlated with salinity in cultured A. tepida but show no correlation with salinity for A. lessonii. Electron microprobe mapping of incorporated Na and Mg of the cultured specimens shows that within chamber walls of A. lessonii, Na / Ca and Mg / Ca occur in elevated bands in close proximity to the primary organic lining. Between species, Mg banding is relatively similar, even though Mg content is 10 times lower and that variation within the chamber wall is much less pronounced in A. tepida. In addition, Na banding is much less prominent in this species than it is in A. lessonii. Inter-species differences in element banding reported here are hypothesized to be caused by differences in biomineralization controls responsible for element uptake.
Serrano, Laetitia; Henry, Raymond P
2008-06-01
Two isoforms of the enzyme carbonic anhydrase (CA) from the gills of the euryhaline green crab were sequenced and identified; these were found to match the cytoplasmic (CAc) and membrane-associated (CAg) isoforms known from other species. The mRNA of the membrane-associated isoform is present in significantly higher levels of abundance in gills of crabs acclimated to 32 ppt, at which the crab is an osmotic and ionic conformer. Upon transfer to low salinity (15 ppt), in which the crab is an osmoregulator, however, the cytoplasmic isoform undergoes a rapid 100-fold increase in abundance in the posterior gills, becoming the dominant isoform. CAg increases 3-fold initially and then remains elevated through 14 days of low salinity acclimation. The induction of CAc mRNA is believed to be the molecular basis for the 20 fold increase in CA protein-specific activity during low salinity acclimation. The initial increase in CAc mRNA takes place at 6 h, and maximal levels of expression are achieved by 24 h; this precedes the induction of CA activity and is within the time in which hemolymph osmotic and ionic concentrations stabilize at new acclimated levels. The increase in expression of the CAg isoform is believed to be more closely related to changes in the population of branchial chloride cells. Changes in the relative abundance of mRNA for the alpha-subunit of the Na(+)/K(+)-ATPase were smaller in magnitude than those for CAc, but the timing was similar. There were no changes in expression of a control gene, arginine kinase (AK) in posterior gills, and there were no significant changes in expression in anterior gills for any of the genes measured here. These results support the use of a control tissue (anterior gills) in addition to a control gene for expression studies.
Ma, Hongtao; Chen, Hongguang; Dong, Aili; Wang, Yanyan; Bian, Yingxue; Xie, Keliang
2017-02-01
To investigate the role of autophagy in hydrogen-rich saline attenuating post-herpetic neuralgia( PHN) in rats. A total of 100 male SD rats were randomly divided into the five groups( n = 20) : control group,PHN group,PHN group treated with hydrogen-rich saline( PHN-H2group),PHN group treated with hydrogen-rich saline and3-MA( PHN-H2-3-MA group),PHN group treated with hydrogen-rich saline and rapamycin( PHN-H2-Rap group). PHN models were established by varicella-zoster virus( VZV) inoculation. After modeling,15 mg / kg 3-MA or 10 mg / kg rapamycin were intraperitoneally injected in corresponding rats with PHN once two days for 3 times. Hydrogen-rich saline( 10 m L / kg)was injected intraperitoneally twice a day for 7 consecutive days in PHN-H2 group,PHN-H2-3-MA group and PHN-H2-Rap group after VZV injection. The paw withdrawal thresholds( PWT) of 50 rats were detected at 3,7,14 and 21 days after modeling. Spinal cord enlargements of the other 50 rats were collected to examine tumor necrosis factor α( TNF-α),interleukine 1β( IL-1β) and IL-6 by ELISA and autophagy protein microtubule-associated protein 1 light chain 3( LC3),beclin 1and P62 by Western blotting. Compared with the control group,the rats in the PHN group presented with decreased PWT,increased levels of TNF-α,IL-1β,IL-6,LC3Ⅱ and beclin 1,and down-regulated P62 expression. Compared with PHN group,the rats in the PHN-H2 group and PHN-H2-Rap group showed increased PWT,decreased levels of TNF-α,IL-1β and IL-6,further up-regulated expressions of LC3 and beclin 1 as wel as P62 expression. Compared with PHN-H2 group,the rats in the PHN-H2-3-MA group had reduced PWT,elevated expressions of TNF-α,IL-1β and IL-6,suppressed expressions of LC3 and beclin 1,and enhanced p62 expression. Hydrogen-rich saline attenuated PWT and inhibited the release of cytokines TNF-α,IL-1β,IL-6 in rats with PHN via activating autophagy.
Ma, Hongtao; Chen, Hongguang; Dong, Aili; Wang, Yanyan; Bian, Yingxue; Xie, Keliang
2017-02-01
Objective To investigate the role of autophagy in hydrogen-rich saline attenuating post-herpetic neuralgia (PHN) in rats. Methods A total of 100 male SD rats were randomly divided into the five groups (n=20): control group, PHN group, PHN group treated with hydrogen-rich saline (PHN-H 2 group), PHN group treated with hydrogen-rich saline and 3-MA (PHN-H 2 -3-MA group), PHN group treated with hydrogen-rich saline and rapamycin (PHN-H 2 -Rap group). PHN models were established by varicella-zoster virus (VZV) inoculation. After modeling, 15 mg/kg 3-MA or 10 mg/kg rapamycin were intraperitoneally injected in corresponding rats with PHN once two days for 3 times. Hydrogen-rich saline (10 mL/kg) was injected intraperitoneally twice a day for 7 consecutive days in PHN-H 2 group, PHN-H 2 -3-MA group and PHN-H 2 -Rap group after VZV injection. The paw withdrawal thresholds (PWT) of 50 rats were detected at 3, 7, 14 and 21 days after modeling. Spinal cord enlargements of the other 50 rats were collected to examine tumor necrosis factor α (TNF-α), interleukine 1β (IL-1β) and IL-6 by ELISA and autophagy protein microtubule-associated protein 1 light chain 3 (LC3), beclin 1 and P62 by Western blotting. Results Compared with the control group, the rats in the PHN group presented with decreased PWT, increased levels of TNF-α, IL-1β, IL-6, LC3II and beclin 1, and down-regulated P62 expression. Compared with PHN group, the rats in the PHN-H 2 group and PHN-H 2 -Rap group showed increased PWT, decreased levels of TNF-α, IL-1β and IL-6, further up-regulated expressions of LC3 and beclin 1 as well as P62 expression. Compared with PHN-H 2 group, the rats in the PHN-H 2 -3-MA group had reduced PWT, elevated expressions of TNF-α, IL-1β and IL-6, suppressed expressions of LC3 and beclin 1, and enhanced p62 expression. Conclusion Hydrogen-rich saline attenuated PWT and inhibited the release of cytokines TNF-α, IL-1β, IL-6 in rats with PHN via activating autophagy.
Estaurine Freshwater Entrainment By Oyster Reefs: Quantifying A Keystone Ecosystem Service
NASA Astrophysics Data System (ADS)
Kaplan, D. A.; Olabarrieta, M.; Frederick, P.; Valle-Levinson, A.; Seavey, J.
2014-12-01
Oyster reefs have been shown to provide myriad critical ecosystem services, however their role in directing flow and currents during non-storm conditions has been largely neglected. In many regions, oyster reefs form as linear structures perpendicular to the coast and across the path of streams and rivers, potentially entraining large volumes of freshwater flow and altering nearshore mixing. We hypothesize that these reefs have the potential to influence salinity over large areas, providing a "keystone" ecosystem service by supporting multiple estuarine functions. Here we present results from a field and modeling study to quantify the effects of reef extent and elevation on estuarine salinities under varying river discharge. We found salinity differences ranging from 2 to 16 g/kg between inshore and offshore sides of degraded oyster reefs in the Suwannee Sound (FL, USA), supporting the role of reefs as local-scale freshwater dams. Moreover, differences between inshore and offshore salinities were correlated with flow, with the most marked differences during periods of low flow. Hydrodynamic modeling using the 3-D Regional Ocean Modeling System (ROMS) suggests that the currently degraded reef system entrained greater volumes of freshwater in the past, buffering the landward advance of high salinities, particularly during low flow events related to droughts. Using ROMS, we also modeled a variety of hypothetical oyster bar morphology scenarios (historical, current, and "restored") to understand how changes in reef structure (elevation, extent, and completeness) impact estuarine mixing and near-shore salinities. Taken together, these results serve to: 1) elucidate a poorly documented ecosystem service of oyster reefs; 2) provide an estimate of the magnitude and sptial extent of the freshwater entrainment effect; and 3) offer quantitative information to managers and restoration specialists interested in restoring oyster habitat.
Vegetation community response to tidal marsh restoration of a large river estuary
Belleveau, Lisa J.; Takekawa, John Y.; Woo, Isa; Turner, Kelley L.; Barham, Jesse B.; Takekawa, Jean E.; Ellings, Christopher S.; Chin-Leo, Gerardo
2015-01-01
Estuaries are biologically productive and diverse ecosystems that provide ecosystem services including protection of inland areas from flooding, filtering freshwater outflows, and providing habitats for fish and wildlife. Alteration of historic habitats, including diking for agriculture, has decreased the function of many estuarine systems, and recent conservation efforts have been directed at restoring these degraded areas to reestablish their natural resource function. The Nisqually Delta in southern Puget Sound is an estuary that has been highly modified by restricting tidal flow, and recent restoration of the delta contributed to one of the largest tidal salt marsh restorations in the Pacific Northwest. We correlated the response of nine major tidal marsh species to salinities at different elevation zones. Our results indicated that wetland species richness was not related to soil pore-water salinity (R2 = 0.03), but were stratified into different elevation zones (R2 = 0.47). Thus, restoration that fosters a wide range of elevations will provide the most diverse plant habitat, and potentially, the greatest resilience to environmental change.
Oxidative stress responses in gills of tilapia (Oreochromis niloticus) at different salinities
NASA Astrophysics Data System (ADS)
Handayani, Kiki Syaputri; Novianty, Zahra; Saputri, Miftahul Rohmah; Irawan, Bambang; Soegianto, Agoes
2017-08-01
The objective of present study is to evaluate the impact of different salinities on the levels of CAT, GSH and MDA of the gills of Nile tilapia (Oreochromis niloticus). Nile tilapia was treated by exposure to salinities concentration 0 ‰, 5 ‰ and 10 ‰. Research models were weakened and sacrificed, then took the left and right sides of the gills. The result of gills homogenity was centrifuged for supernatan, then supernatan was proceed with testing levels of CAT, GSH and MDA by ELISA assay methods. The levels of CAT in gills were significantly higher at 10 ‰ than at 5 ‰ and 0 ‰. The levels of GSH in gills were significantly higher at 0 ‰ than 5 ‰. The levels of GSH in gills at 5 ‰ and 10 ‰ salinities were not significantly different. The levels of MDA in gills at salinity 10 ‰ and 5 ‰ were higher than in control gills at 0 ‰ salinities. This occurs because the salinity of 10 ‰ salinity was optimal for live of fish tilapia. In conclusion, salinity impact the increasing of CAT, GSH, and MDA levels in gills of Nile tilapia.
Starbuck, Elizabeth M; Fitts, Douglas A
2002-10-04
The subfornical organ (SFO) may act as a sodium- or osmoreceptor that drives hypothalamic and other nuclei to secrete vasopressin and to elicit drinking. However, in response to mild doses of hypertonic saline, Fos-like immunoreactivity (Fos-ir) is absent in the SFO whereas it is well expressed in the hypothalamic supraoptic (SON) and paraventricular (PVN) nuclei. This suggests that the hypothalamus may be activated in advance of the SFO. In this study, the fibers connecting the SFO and hypothalamus were disconnected by a wire knife cut so that Fos-ir could be examined in both the SFO and hypothalamus after an intragastric (ig) load of 0.5% of body weight of 0.6 M NaCl. Compared with Fos-ir in isotonic-loaded rats, Fos-ir after the hypertonic load was not significantly elevated in the SFO or median preoptic nucleus in sham-cut or knife-cut rats and was only slightly elevated in the OVLT in sham-cut rats. However, the hypertonic load in sham-cut rats greatly elevated Fos-ir in the SON and in the entire PVN, but this expression was reduced significantly by 30-50% in knife-cut rats. Thus, the connectivity between SFO and the hypothalamus is critical for the full expression of Fos-ir in the hypothalamus during moderate ig hypertonic saline loading even when the SFO itself does not yet express Fos-ir.
Xia, Qing; Jiang, Jun-Ming; Gong, Xu; Chen, Guang-Yuan; Li, Lei; Huang, Zong-Wen
2000-01-01
AIM: To investigate the role of tumor necrosis factor (TNF) in lung injury during acute necrotizing pancreatitis (ANP), and the therapeutic ef fect of “Tong Xia” purgative method in minimizing the severity of lung injury. METHODS: Fourteen canines were randomly divided into 3 groups: the “Tong Xia” treatment group (n = 5) using Dachengqitang; saline control group (n = 5), and the sham operation group (n = 4). TNF activity in serum and in bronchoalveolar lavage fluid (BALF), the serum endotoxin levels were meas ured, and the severity of lung injury evaluated. RESULTS: Elevation of TNF activity was more prominent in BALF than in serum. TNF activity in serum at 6 and 12 h and in BALF was significantly decreased in the “Tong Xia” treatment group than in the saline control one (q = 21.11, q = 12.07, q = 9.03, respectively, P < 0.01) and the lung injury was significantly alleviated at 12 h as compared with that in the saline group, manifested as amelioration of the lung wet/dry weight ratio, decrease in protein concentration and neutrophils count in BALF, and improvement of pulmonary inflammatory changes. A positive correlation was demonstrated between serum TNF activity and endotoxin level. CONCLUSION: Hypersecretion of TNF is shown to be one of the majo r causes of lung injury during ANP; “Tong Xia” purgative method could allevia te the degree of lung injury mediated by TNF. PMID:11819536
Cory, Robert L.; Nauman, Jon W.
1970-01-01
The effect of power plant cooling water in raising natural water temperatures at a location near the power plant on the Patuxent River estuary is clearly evident from thermograph records. Surface temperature at a station 333 m (1,000 ft) downstream from the discharge canal was raised an average of about 4 C, and at times by as much as 8 C. Temperature rises were greatest during the winter. Infrared imagery showed that elevated surface temperatures could be detected about 5.5 km (3 nautical miles) upstream at flood tide. Temperature profiles obtained from airborne radiation equipment revealed a complicated surface temperature pattern and also showed the effects of density differences and wind action on the steam-electric station (S.E.S.) effluent plume. Mean annual salinity for a 5-year period (1963–1967) was highest in 1966, about 12.3 ‰, and lowest in 1967, about 9.9‰. Dissolved oxygen values for 1966–1967 ranged from 3.2 to 15.6 mg/l, and saturation ranged from 55 to 152%. Turbidity levels were inversely related to salinity, with the highest annual, mean of 28 JCU (Jackson Candle Units) occurring in 1967, the lowest salinity year. The extreme tide range was 2.1 m (6.7 ft); mean water levels at the Patuxent Bridge were highest in summer and lowest in winter. Water stages are more affected by wind speed and direction than by flow in the river.
Cardiorespiratory Changes During Microwave-Induced Lethal Heat Stress and Beta-adrenergic Blockade
1994-01-01
J. A. Taylor, J. K . Kalls , J. Nit- verse these responses. Fundam. Appl. Toxicol. 10- 506-516, 1988. tolo, R. W. Hicks, T. G. Lohmnan, and J. H...propanolol groups were significantly lower than in saline controls. Respiratory rate was significantly elevated during most of the exposure period in...lar and respiratory changes) during lethal exposures. Al- propranolol groups were significantly lower than in saline con- though the pathophysiology
Caffeine accelerates recovery from general anesthesia
Wang, Qiang; Fong, Robert; Mason, Peggy; Fox, Aaron P.
2013-01-01
General anesthetics inhibit neurotransmitter release from both neurons and secretory cells. If inhibition of neurotransmitter release is part of an anesthetic mechanism of action, then drugs that facilitate neurotransmitter release may aid in reversing general anesthesia. Drugs that elevate intracellular cAMP levels are known to facilitate neurotransmitter release. Three cAMP elevating drugs (forskolin, theophylline, and caffeine) were tested; all three drugs reversed the inhibition of neurotransmitter release produced by isoflurane in PC12 cells in vitro. The drugs were tested in isoflurane-anesthetized rats. Animals were injected with either saline or saline containing drug. All three drugs dramatically accelerated recovery from isoflurane anesthesia, but caffeine was most effective. None of the drugs, at the concentrations tested, had significant effects on breathing rates, O2 saturation, heart rate, or blood pressure in anesthetized animals. Caffeine alone was tested on propofol-anesthetized rats where it dramatically accelerated recovery from anesthesia. The ability of caffeine to accelerate recovery from anesthesia for different chemical classes of anesthetics, isoflurane and propofol, opens the possibility that it will do so for all commonly used general anesthetics, although additional studies will be required to determine whether this is in fact the case. Because anesthesia in rodents is thought to be similar to that in humans, these results suggest that caffeine might allow for rapid and uniform emergence from general anesthesia in human patients. PMID:24375022
NASA Astrophysics Data System (ADS)
Xiao, Han; Wang, Dingbao; Hagen, Scott C.; Medeiros, Stephen C.; Hall, Carlton R.
2016-11-01
A three-dimensional variable-density groundwater flow and salinity transport model is implemented using the SEAWAT code to quantify the spatial variation of water-table depth and salinity of the surficial aquifer in Merritt Island and Cape Canaveral Island in east-central Florida (USA) under steady-state 2010 hydrologic and hydrogeologic conditions. The developed model is referred to as the `reference' model and calibrated against field-measured groundwater levels and a map of land use and land cover. Then, five prediction/projection models are developed based on modification of the boundary conditions of the calibrated `reference' model to quantify climate change impacts under various scenarios of sea-level rise and precipitation change projected to 2050. Model results indicate that west Merritt Island will encounter lowland inundation and saltwater intrusion due to its low elevation and flat topography, while climate change impacts on Cape Canaveral Island and east Merritt Island are not significant. The SEAWAT models developed for this study are useful and effective tools for water resources management, land use planning, and climate-change adaptation decision-making in these and other low-lying coastal alluvial plains and barrier island systems.
Capps, Krista A.; Nico, Leo G.; Mendoza-Carranza, Manuel; Arevalo-Frias, Wendi; Ropicki, Andrew J.; Heilpern, Sebastian A.; Rodiles-Hernandez, Rocio
2011-01-01
1. Salinity tolerance is one of several important physiological attributes that determine invasion success and the pattern of dispersal of introduced aquatic organisms. Introduced freshwater fishes able to tolerate elevated salinities have the potential to invade and exploit brackish-water (mixohaline) environments and use estuaries and coastal waters as 'bridges' for dispersing from one coastal river system to another. 2. Several members of the neotropical suckermouth armoured catfish genus Pterygoplichthys (Siluriformes: Loricariidae) have established non-native populations in inland waters of North and Central America, Asia and islands in the Caribbean, and Pacific and Indian oceans. Loricariids are generally considered to be strictly freshwater; but a few naturally occur in mesohaline habitats. 3.Catch and habitat data from 2004–2005 and 2009–2011 fish surveys in the Grijalva–Usumacinta River delta region (south-eastern Mexico) confirmed that introduced Pterygoplichthys populations established in upstream freshwater sites (where these catfish are abundant) have recently dispersed into downstream oligohaline and mesohaline estuarine habitats. During 2009–2011 surveys, these non-native catfish — tentatively identified as P. pardalis or its hybrids — were found in sites with salinities ranging from 1 to 8 ppt (mean 5.2 ppt). 4.Acute-salinity experiments were conducted with Pterygoplichthys (110–302 mm standard length, N=140) captured in the Grijalva–Usumacinta Basin to determine upper salinity tolerance levels. Tests demonstrated that individuals maintained in salinities of 0.2 ppt were able to survive abrupt (acute) exposure to salinities up to 10 ppt with little mortality over 10 days (240 h experimental endpoint). A few individuals survived abrupt exposure to 11 and 12 ppt for 20 or more hours, although none survived more than a few hours at 16 ppt or greater. 5.These field and experimental results provide quantitative evidence that non-native Pterygoplichthys are physiologically capable of surviving mesohaline conditions for extended periods and that non-native populations in Mexico are invading and presumably exploiting estuarine and other coastal environments, perhaps as feeding areas and potentially as dispersal routes.
NASA Astrophysics Data System (ADS)
Harvey, C. F.; Michael, H. A.
2017-12-01
We formulate the energy balance for coastal groundwater systems and apply it to: (1) Explain the energy driving offshore saline circulation cells, and; (2) Assess the accuracy of numerical simulations of coastal groundwater systems. The flow of fresh groundwater to the ocean is driven by the loss of potential energy as groundwater drops from the elevation of the inland watertable, where recharge occurs, to discharge at sea level. This freshwater flow creates an underlying circulation cell of seawater, drawn into coastal aquifers offshore and discharging near shore, that adds to total submarine groundwater discharge. The saline water in the circulation cell enters and exits the aquifer through the sea floor at the same hydraulic potential. Existing theory explains that the saline circulation cell is driven by mixing of fresh and saline without any additional source of potential or mechanical power. This explanation raises a basic thermodynamic question: what is the source of energy that drives the saline circulation cell? Here, we resolve this question by building upon Hubbert's conception of hydraulic potential to formulate an energy balance for density-dependent flow and salt transport through an aquifer. We show that, because local energy dissipation within the aquifer is proportional to the square of the groundwater velocity, more groundwater flow may be driven through an aquifer for a given energy input if local variations in velocity are smoothed. Our numerical simulations of coastal groundwater systems show that dispersion of salt across the fresh-saline interface spreads flow over larger volumes of the aquifer, smoothing the velocity field, and increasing total flow and submarine groundwater discharge without consuming more power. The energy balance also provides a criterion, in addition to conventional mass balances, for judging the accuracy of numerical solutions of non-linear density-dependent flow problems. Our results show that some numerical simulations of saline circulation converge to excellent balances of both mass and energy, but that other simulations may poorly balance energy even after converging to a good mass balance. Thus, the energy balance can be used to identify incorrect simulations that pass convential mass balance criteria for accuracy.
Shabir, Rahat; Abbas, Ghulam; Saqib, Muhammad; Shahid, Muhammad; Shah, Ghulam Mustafa; Akram, Muhammad; Niazi, Nabeel Khan; Naeem, Muhammad Asif; Hussain, Munawar; Ashraf, Farah
2018-06-07
In this study, we explored the effect of salinity on cadmium (Cd) tolerance and phytoremediation potential of Acacia nilotica. Two-month-old uniform plants of A. nilotica were grown in pots contaminated with various levels of Cd (0, 5, 10, and 15 mg kg -1 ), NaCl (0%, 0.5%, 1.0% (hereafter referred as salinity), and all possible combinations of Cd + salinity for a period of six months. Results showed that shoot and root growth, biomass, tissue water content and chlorophyll (chl a, chl b, and total chl a+b) contents decreased more in response to salinity and combination of Cd + salinity compared to Cd alone. Shoot and root K concentrations significantly decreased with increasing soil Cd levels, whereas Na and Cl concentrations were not affected significantly. Shoot and root Cd concentrations, bioconcentration factor (BCF) and translocation factor (TF) increased with increasing soil Cd and Cd + salinity levels. At low level of salinity (0.5%), shoot and root Cd uptake enhanced, while it decreased at high level of salinity (1.0%). Due to Cd tolerance, high shoot biomass and shoot Cd uptake, this tree species has some potential for phytoremediation of Cd from the metal contaminated saline and nonsaline soils.
NASA Astrophysics Data System (ADS)
Huizer, S.; Karaoulis, M. C.; Oude Essink, G. H. P.; Bierkens, M. F. P.
2017-08-01
Tidal dynamics and especially storm surges can have an extensive impact on coastal fresh groundwater resources. Combined with the prospect of sea-level rise and the reliance of many people on these resources, this demonstrates the need to assess the vulnerability of coastal areas to these threats. In this study, we investigated the impact of tides and storm surges on coastal groundwater at a pilot location on the Dutch coast (viz., the Sand Engine). To monitor changes in groundwater salinity under a variety of conditions, we performed automated measurements with electrical resistivity tomography for a period of 2 months between November 2014 and January 2015. The obtained resistivity images were converted to salinity images, and these images served effectively as observations of the impact of tidal fluctuations, saltwater overwash during storm surges, and the recovery of the freshwater lens after land-surface inundations. Most of the observed changes in groundwater head and salinity could be reproduced with a two-dimensional variable-density groundwater flow and salt transport model. This shows that groundwater models can be used to make accurate predictions of the impact of tides and storm surges on fresh groundwater resources, given a thorough understanding of the (local) system. Comparisons of measurements and model simulations also showed that morphological changes and wave run-up can have a strong impact on the extent of land-surface inundations in (low-elevation) dynamic coastal environments, and can therefore substantially affect coastal fresh groundwater resources.
Osmotic and ionic regulation in shore crabs Carcinus maenas inhabiting a tidal estuary
NASA Astrophysics Data System (ADS)
Winkler, A.; Siebers, D.; Becker, W.
1988-03-01
Shore crabs Carcinus maenas were exposed to salinities fluctuating according to the natural tidal rhythm. To this end they were maintained in net cages positioned in the estuarine waters of the river Elbe. The cages were lifted every hour, and between 8 12 specimens were analyzed for hemolymph concentrations of Na, K, Ca, Mg, and osmolality. The results obtained were compared with the respective data measured in external brackish water. In addition, the specific activity of Na-K-ATPase in a posterior gill was determined. Hemolymph Na and Mg as well as branchial Na-K-ATPase were also determined in crabs collected in the North Sea and the Baltic. The results show that in C. maenas living in salinities fluctuating with the tides by approx. 15‰ S, Na, K and Ca were hyperregulated, and Mg was effectively hyporegulated. The concentrations of all hemolymph ions and the activity of the Na-K-ATPase were kept constant over the whole tidal cycle. In Baltic crabs, Na was effectively hyperregulated and gill Na-K-ATPase was significantly elevated by a factor of ca 2 when compared with North Sea crabs. It is suggested that long-term hyperregulation of Na in constant salinities results from an increased number of Na-K-ATPase molecules which may change by synthesis or degradation following salinity stress. Constant hemolymph levels of hyperregulated Na in crabs inhabiting fluctuating brackish water are accomplished by activation of existing Na-K-ATPase by low Na and inhibition by higher ambient concentrations.
NASA Astrophysics Data System (ADS)
Khamzina, Asia; Kumar, Navneet; Heng, Lee
2017-04-01
In the lower Amu Darya River Basin, the decades of intensive irrigation led to elevated groundwater tables, resulting in ubiquitous soil salinization and adverse impact on crop production. Field-scale afforestation trials and farm-scale economic analyses in the Khorezm region have determined that afforestation can be an environmentally and financially attractive land-use option for degraded croplands because it combines a diversified agricultural production, carbon sequestration, an improved soil health and minimizes the use of irrigation water. We examined prospects for upscaling afforestation activity for regional land-use planning considering prevailing constraints in irrigated agriculture landscape. Assessment of salinity-induced cropland productivity decline using satellite imagery of multiple spatial and temporal resolution revealed that 18-38% of the marginally productive or abandoned cropland might be considered for conversion to agroforestry. Furthermore, a regional-scale water balance suggests that most of these marginal croplands are characterized by sufficient surface water supplies for irrigating the newly planted saplings, before they are able to rely on the groundwater alone. However, the 10-year monitoring of soil salt dynamics in the afforestation trials reveals increasing salinity levels due to the salt exclusion from the root water uptake by the trees. Further study focuses on enhancing long-term sustainability of afforestation as a management option for highly saline lands by examining salt tolerance of candidate species using 13C isotopic signature as the indicator of water and salt stress, salt leaching needs and implications for regional scale planning.
Fokina, N N; Bakhmet, I N; Shklyarevich, G A; Nemova, N N
2014-12-01
A study on the effect oil pollution under normal and reduced salinity had on blue mussels Mytilus edulis L. from the White Sea in an aquarium-based experiment and in the natural habitat revealed a change in gill total lipids as a compensatory response. The cholesterol concentration and the cholesterol/phospholipids ratio in gills were found to reflect the impact of the environmental factors (oil pollution and desalination), and evidence adaptive changes in the cell membrane structure. An elevated content of storage lipids (chiefly triacylglycerols) in the mussels in the aquarium experiment indicates, first of all, the uptake and accumulation of oil products in gill cells under both normal and reduced seawater salinity, while high triacylglycerols level in gill littoral mussels from 'control' biotope in the Gulf of Kandalaksha is primarily associated with the mussel׳s pre-spawning period. Copyright © 2014 Elsevier Inc. All rights reserved.
Selective responses of benthic foraminifera to thermal pollution.
Titelboim, Danna; Almogi-Labin, Ahuva; Herut, Barak; Kucera, Michal; Schmidt, Christiane; Hyams-Kaphzan, Orit; Ovadia, Ofer; Abramovich, Sigal
2016-04-15
Persistent thermohaline pollution at a site along the northern coast of Israel, due to power and desalination plants, is used as a natural laboratory to evaluate the effects of rising temperature and salinity levels on benthic foraminifera living in shallow hard-bottom habitats. Biomonitoring of the disturbed area and a control station shows that elevated temperature is a more significant stressor compared to salinity, thus causing a decrease in abundance and richness. Critical temperature thresholds were observed at 30 and 35°C, the latter representing the most thermally tolerant species in the studied area Pararotalia calcariformata, which is the only symbiont-bearing species observed within the core of the heated area. Common species of the shallow hard-bottom habitats including several Lessepsian invaders are almost absent in the most exposed site indicating that excess warming will likely impede the survival of these species that currently benefit from the ongoing warming of the Eastern Mediterranean. Copyright © 2016 Elsevier Ltd. All rights reserved.
Winder, Monika; Jassby, Alan D; Mac Nally, Ralph
2011-08-01
Environmental perturbation, climate change and international commerce are important drivers for biological invasions. Climate anomalies can further increase levels of habitat disturbance and act synergistically to elevate invasion risk. Herein, we use a historical data set from the upper San Francisco Estuary to provide the first empirical evidence for facilitation of invasions by climate extremes. Invasive zooplankton species did not become established in this estuary until the 1970s when increasing propagule pressure from Asia coincided with extended drought periods. Hydrological management exacerbated the effects of post-1960 droughts and reduced freshwater inflow even further, increasing drought severity and allowing unusually extreme salinity intrusions. Native zooplankton experienced unprecedented conditions of high salinity and intensified benthic grazing, and life history attributes of invasive zooplankton were advantageous enough during droughts to outcompete native species and colonise the system. Extreme climatic events can therefore act synergistically with environmental perturbation to facilitate the establishment of invasive species. © 2011 Blackwell Publishing Ltd/CNRS.
Effects of volume loading and pressor agents in idiopathic orthostatic tachycardia
NASA Technical Reports Server (NTRS)
Jacob, G.; Shannon, J. R.; Black, B.; Biaggioni, I.; Mosqueda-Garcia, R.; Robertson, R. M.; Robertson, D.
1997-01-01
BACKGROUND: Idiopathic orthostatic tachycardia (IOT) is characterized by an increase in heart rate (HR) with standing of > or = 30 bpm that is associated with elevated catecholamine levels and orthostatic symptoms. A dynamic orthostatic hypovolemia and alpha1-adrenoreceptor hypersensitivity have been demonstrated in IOT patients. There is evidence of an autonomic neuropathy affecting the lower-extremity blood vessels. METHODS AND RESULTS: We studied the effects of placebo, the alpha1-adrenoreceptor agonist midodrine (5 to 10 mg), the alpha2-adrenoreceptor agonist clonidine (0.1 mg), and I.V. saline (1 L) in 13 patients with IOT. Supine and upright blood pressure (BP) and HR were measured before and at 1 and 2 hours after intervention. Midodrine decreased both supine and upright HR (all HR values are given as bpm) at 2 hours (from 78+/-2 supine to 108+/-5 upright before treatment and from 69+/-2 supine to 95+/-5 upright after treatment, P<.005 for supine and P<.01 for upright). Saline decreased both supine and upright HR (from 80+/-3 supine to 112+/-5 upright before infusion and from 77+/-3 supine to 91+/-3 upright 1 hour after infusion, P<.005 for supine and P<.001 for upright). Clonidine decreased supine HR (from 78+/-2 to 74+/-2, P<.03) but did not affect the HR increase with standing. Clonidine very significantly decreased supine systolic BP (from 109+/-3 at baseline to 99+/-2 mm Hg at 2 hours, P<.001), and midodrine decreased supine systolic BP mildly. CONCLUSIONS: IOT responds best acutely to saline infusion to correct the underlying hypovolemia. Chronically, this can be accomplished with increased salt and water intake in conjunction with fludrocortisone. The response of patients to the alpha1-agonist midodrine supports the hypothesis of partial dysautonomia and indicates that the use of alpha1-agonists to pharmacologically replace lower-extremity postganglionic sympathetics is an appropriate overall goal of therapy. These findings are consistent with our hypothesis that the tachycardia and elevated catecholamine levels associated with IOT are principally due to hypovolemia and loss of adequate lower-extremity vascular tone.
Alkaline tide and nitrogen conservation after feeding in an elasmobranch (Squalus acanthias).
Wood, Chris M; Kajimura, Makiko; Mommsen, Thomas P; Walsh, Patrick J
2005-07-01
We investigated the consequences of feeding for acid-base balance, nitrogen excretion, blood metabolites and osmoregulation in the Pacific spiny dogfish. Sharks that had been starved for 7 days were surgically fitted with indwelling stomach tubes for gastric feeding and blood catheters for repetitive blood sampling and were confined in chambers, allowing measurement of ammonia-N and urea-N fluxes. The experimental meal infused via the stomach tube consisted of flatfish muscle (2% of body mass) suspended in saline (4% of body mass total volume). Control animals received only saline (4% of body mass). Feeding resulted in a marked rise in both arterial and venous pH and HCO3- concentrations at 3-9 h after the meal, with attenuation by 17 h. Venous P(O2) also fell. As there were negligible changes in P(CO2), the response was interpreted as an alkaline tide without respiratory compensation, associated with elevated gastric acid secretion. Urea-N excretion, which comprised >90% of the total, was unaffected, while ammonia-N excretion was very slightly elevated, amounting to <3% of the total-N in the meal over 45 h. Plasma ammonia-N rose slightly. Plasma urea-N, TMAO-N and glucose concentrations remained unchanged, while free amino acid and beta-hydroxybutyrate levels exhibited modest declines. Plasma osmolality was persistently elevated after the meal relative to controls, partially explained by a significant rise in plasma Cl-. This marked post-prandial conservation of nitrogen is interpreted as reflecting the needs for urea synthesis for osmoregulation and protein growth in animals that are severely N-limited due to their sporadic and opportunistic feeding lifestyle in nature.
Evidence for Neuroinflammatory and Microglial Changes in the Cerebral Response to Sleep Loss
Wisor, Jonathan P.; Schmidt, Michelle A.; Clegern, William C.
2011-01-01
Study Objectives: Sleep loss has pro-inflammatory effects, but the roles of specific cell populations in mediating these effects have not been delineated. We assessed the modulation of the electroencephalographic and molecular responses to sleep deprivation (S-DEP) by minocycline, a compound that attenuates microglial activation occurring in association with neuroinflammatory events. Design: Laboratory rodents were subjected to assessment of sleep and wake in baseline and sleep deprived conditions. Participants: Adult male CD-1 mice (30-35 g) subjected to telemetric electroencephalography. Interventions: Minocycline was administered daily. Mice were subjected to baseline data collection on the first day of minocycline administration and, on subsequent days, 2 S-DEP sessions, 1 and 3 h in duration, followed by recovery sleep. Following EEG studies, mice were euthanized either at the end of a 3 h S-DEP or as time-of day controls for sampling of brain messenger RNAs. Gene expression was measured by real-time polymerase chain reaction. Measurements and Results: Minocycline-treated mice exhibited a reduction in time spent asleep, relative to saline-treated mice, in the 3-h interval immediately after administration. S-DEP resulted in an increase in EEG slow wave activity relative to baseline in saline-treated mice. This response to S-DEP was abolished in animals subjected to chronic minocycline administration. S-DEP suppressed the expression of the microglial-specific transcript cd11b and the neuroinflammation marker peripheral benzodiazepine receptor, in the brain at the mRNA level. Minocycline attenuated the elevation of c-fos expression by S-DEP. Brain levels of pro-inflammatory cytokine mRNAs interleukin-1β (il-1β), interleukin-6 (il-6), and tumor necrosis factor-α (tnfα) were unaffected by S-DEP, but were elevated in minocycline-treated mice relative to saline-treated mice. Conclusions: The anti-neuroinflammatory agent minocycline prevents either the buildup or expression of sleep need in rodents. The molecular mechanism underlying this effect is not known, but it is not mediated by suppression of il-1β, il-6, and tnfα at the transcript level. Citation: Wisor JP; Schmidt MA; Clegern WC. Evidence for neuroinflammatory and microglial changes in the cerebral response to sleep loss. SLEEP 2011;34(3):261-272. PMID:21358843
Shuster, Katherine A; Wrobleski, Shirley K; Hawley, Angela E; Lucchesi, Benedict R; Sorenson, Dorothy R; Bergin, Ingrid L; Sigler, Robert E; Guire, Kenneth E; Nowland, Megan H; Wakefield, Thomas W; Myers, Daniel D
2013-01-01
The use of thrombolytic agents has greatly improved patient outcomes, but the prothrombotic response to these drugs in vivo is unknown. Approximately 24 h after we induced thrombosis in male Sprague–Dawley rats, we placed an infusion line in the inferior vena cava and administered either saline or a thrombolytic agent (tissue plasminogen activator [tPA] or plasmin) for 30 min. Blood was drawn immediately after infusion; rats were euthanized 24 h after infusion for collection of blood and tissue (inferior vena cava and thrombus). Thrombus size was decreased in the tPA-treated rats but not in those that received saline or plasmin; this change correlated with the significant rise in D-dimer levels noted immediately after infusion in the tPA-treated rats. Plasma soluble P-selectin, a prothrombotic marker, was elevated at 24 h in the plasmin group compared with the other treatment groups. There were no significant differences in plasma C3a, C5a, or C5b9 levels or in thrombus C3 levels between groups. According to ultrastructural analysis, thrombus structure and vein wall effects did not differ between groups. Local tPA did not induce a prothrombotic state during acute DVT or after thrombolytic therapy in a rodent model of venous thrombolysis. Conversely, levels of the prothrombotic marker plasma soluble P-selectin increased when plasmin was administered. PMID:23759527
NASA Astrophysics Data System (ADS)
Skrzypek, Grzegorz; Dogramaci, Shawan; Rouillard, Alexandra; Grierson, Pauline F.
2016-11-01
Very small groundwater outflows have the potential to significantly impact the hydrochemistry and salt accumulation processes of notionally terminal basins in arid environments. However, this limited groundwater outflow can be very difficult to quantify using classical water budget calculations due to large uncertainties in estimates of evaporation and evapotranspiration rates from the surface of dry lake beds. In this study, we used a dimensionless time evaporation model to estimate the range of groundwater outflow required to maintain salinity levels observed at the Fortescue Marsh (FM), one of the largest wetlands of semi-arid northwest Australia (∼1100 km2). The groundwater outflow from aquifers underlying the FM to the Lower Fortescue catchment is constrained by an extremely low hydraulic gradient of <0.0001 and a small 'alluvial outlet' of 0.35 km2 because of relatively high bedrock elevation. However, FM groundwater salinity is far below saturation with respect to halite (TDS < 160 g/L), episodic flood water is fresh to brackish, and salt efflorescences are very sparse and evident only when the FM is dry. We show that if the FM was 100% "leakage free" i.e., a true terminal basin, groundwater would have achieved halite saturation (>300 g/L) after ∼45 ka. We calculated that only a very small seepage of ∼2G L/yr (∼0.03% of the FM water volume) is sufficient to maintain current salinity conditions. The minimum time required to develop the current hydrochemical groundwater composition under the FM ranges from ∼60 to ∼165 ka. We conclude that a dimensionless time evaporation model versus inflow over outflow ratio model is likely more suitable than classical water budget calculations for determining outflow from large saline lakes and to estimate groundwater seepage from hydrologically terminal basins.
Kim, Chea-Ha
2015-01-01
We have previously reported that the intracerebroventricular (i.c.v.) administration of kainic acid (KA) results in significant neuronal damage on the hippocampal CA3 region. In this study, we examined possible changes in the blood glucose level after i.c.v. pretreatment with KA. The blood glucose level was elevated at 30 min, began to decrease at 60 min and returned to normal at 120 min after D-glucose-feeding. We found that the blood glucose level in the KA-pretreated group was higher than in the saline-pretreated group. The up-regulation of the blood glucose level in the KA-pretreated group was still present even after 1~4 weeks. The plasma corticosterone and insulin levels were slightly higher in the KA-treated group. Corticosterone levels decreased whereas insulin levels were elevated when mice were fed with D-glucose. The i.c.v. pretreatment with KA for 24 hr caused a significant reversal of D-glucose-induced down-regulation of corticosterone level. However, the insulin level was enhanced in the KA-pretreated group compared to the vehicle-treated group when mice were fed with D-glucose. These results suggest that KA-induced alterations of the blood glucose level are related to cell death in the CA3 region whereas the up-regulation of blood glucose level in the KA-pretreated group appears to be due to a reversal of D-glucose feeding-induced down-regulation of corticosterone level. PMID:25792867
Kim, Chea-Ha; Hong, Jae-Seung
2015-03-01
We have previously reported that the intracerebroventricular (i.c.v.) administration of kainic acid (KA) results in significant neuronal damage on the hippocampal CA3 region. In this study, we examined possible changes in the blood glucose level after i.c.v. pretreatment with KA. The blood glucose level was elevated at 30 min, began to decrease at 60 min and returned to normal at 120 min after D-glucose-feeding. We found that the blood glucose level in the KA-pretreated group was higher than in the saline-pretreated group. The up-regulation of the blood glucose level in the KA-pretreated group was still present even after 1~4 weeks. The plasma corticosterone and insulin levels were slightly higher in the KA-treated group. Corticosterone levels decreased whereas insulin levels were elevated when mice were fed with D-glucose. The i.c.v. pretreatment with KA for 24 hr caused a significant reversal of D-glucose-induced down-regulation of corticosterone level. However, the insulin level was enhanced in the KA-pretreated group compared to the vehicle-treated group when mice were fed with D-glucose. These results suggest that KA-induced alterations of the blood glucose level are related to cell death in the CA3 region whereas the up-regulation of blood glucose level in the KA-pretreated group appears to be due to a reversal of D-glucose feeding-induced down-regulation of corticosterone level.
Zaghmouri, Imen; Michotey, Valerie D; Armougom, Fabrice; Guasco, Sophie; Bonin, Patricia C
2018-05-01
The sensitivity of denitrifying community to salinity fluctuations was studied in microcosms filled with marine coastal sediments subjected to different salinity disturbances over time (sediment under frequent salinity changes vs sediment with "stable" salinity pattern). Upon short-term salinity shift, denitrification rate and denitrifiers abundance showed high resistance whatever the sediment origin is. Denitrifying community adapted to frequent salinity changes showed high resistance when salinity increases, with a dynamic nosZ relative expression level. Marine sediment denitrifying community, characterized by more stable pattern, was less resistant when salinity decreases. However, after two successive variations of salinity, it shifted toward the characteristic community of fluctuating conditions, with larger proportion of Pseudomonas-nosZ, exhibiting an increase of nosZ relative expression level. The impact of long-term salinity variation upon bacterial community was confirmed at ribosomal level with a higher percentage of Pseudomonas and lower proportion of nosZII clade genera. Copyright © 2018 Elsevier Ltd. All rights reserved.
Space Radar Image of Saline Valley, California
NASA Technical Reports Server (NTRS)
1999-01-01
This is a three-dimensional perspective view of Saline Valley, about 30 km (19 miles) east of the town of Independence, California created by combining two spaceborne radar images using a technique known as interferometry. Visualizations like this one are helpful to scientists because they clarify the relationships of the different types of surfaces detected by the radar and the shapes of the topographic features such as mountains and valleys. The view is looking southwest across Saline Valley. The high peaks in the background are the Inyo Mountains, which rise more than 3,000 meters (10,000 feet) above the valley floor. The dark blue patch near the center of the image is an area of sand dunes. The brighter patches to the left of the dunes are the dry, salty lake beds of Saline Valley. The brown and orange areas are deposits of boulders, gravel and sand known as alluvial fans. The image was constructed by overlaying a color composite radar image on top of a digital elevation map. The radar image was taken by the Spaceborne Imaging Radar-C/X-bandSynthetic Aperture Radar (SIR-C/X-SAR) on board the space shuttleEndeavour in October 1994. The digital elevation map was producedusing radar interferometry, a process in which radar data are acquired on different passes of the space shuttle. The two data passes are compared to obtain elevation information. The elevation data were derived from a 1,500-km-long (930-mile) digital topographic map processed at JPL. Radar image data are draped over the topography to provide the color with the following assignments: red is L-band vertically transmitted, vertically received; green is C-band vertically transmitted, vetically received; and blue is the ratio of C-band vertically transmitted, vertically received to L-band vertically transmitted, vertically received. This image is centered near 36.8 degrees north latitude and 117.7 degrees west longitude. No vertical exaggeration factor has been applied to the data. SIR-C/X-SAR, a joint mission of the German, Italian, and the United States space agencies, is part of NASA's Mission to Planet Earth.
Harvey, Martyn; Cave, Grant; Hoggett, Kerry
2009-02-01
Drug sequestration to an expanded plasma lipid phase has been proposed as a potential mechanism of action for lipid emulsions in lipophilic cardiotoxin overdose. The authors set out to document plasma and peritoneal diasylate clomipramine concentration after resuscitation with lipid emulsion in a rabbit model of clomipramine-induced hypotension. Twenty sedated mechanically ventilated New Zealand White rabbits were allocated to receive either 12 mL/kg 20% Intralipid or 12 mL/kg saline solution, following clomipramine infusion to 50% baseline mean arterial pressure (MAP). Hemodynamic parameters and serum clomipramine concentration were determined to 59 minutes. Peritoneal dialysis with 20% Intralipid or saline solution was evaluated for clomipramine concentration. Mean arterial pressure was greater in lipid-treated animals as assessed by repeated-measures analysis of variance (F[1,14] = 6.84; p = 0.020). Lipid infusion was associated with elevated plasma clomipramine concentration and reduced initial volume of distribution (Vd; 5.7 [+/-1.6] L/kg lipid vs. 15.9 [+/-7.2] L/kg saline; p = 0.0001). Peritoneal diasylate clomipramine concentration was greater in lipid-treated animals (366.2 [+/-186.2] microg/L lipid vs. 37.7 [+/-13.8] microg/L saline; p = 0.002). Amelioration of clomipramine-induced hypotension with lipid infusion is associated with reduced initial Vd and elevated plasma clomipramine concentration consistent with intravascular drug-lipid sequestration. Concomitant peritoneal dialysis with lipid emulsion enhances clomipramine extraction.
Gupta, Poulami; De, Bratati
2017-07-03
A GC-MS based analytical approach was undertaken to understand the metabolomic responses of seedlings of 2 salt sensitive (Sujala and MTU 7029) and 2 tolerant varieties (Bhutnath, and Nonabokra) of indica rice (Oryza sativa L.) to NaCl induced stress. The 4 varieties responded differently to NaCl treatment with respect to the conserved primary metabolites (sugars, polyols, amino acids, organic acids and certain purine derivatives) of the leaf of rice seedlings. However, there were significant differences in salt induced production of chorismic acid derivatives. Serotonin level was increased in both the salt tolerant varieties in response to NaCl induced stress. In both the salt tolerant varieties, increased production of the signaling molecule gentisic acid in response to NaCl treatment was noticed. Salt tolerant varieties also produced increased level of ferulic acid and vanillic acid. In the salt sensitive varieties, cinnamic acid derivatives, 4-hydroxycinnamic acid (in Sujala) and 4-hydroxybenzoic acid (in MTU 7029), were elevated in the leaves. So increased production of the 2 signaling molecules serotonin and gentisic acid may be considered as 2 important biomarker compounds produced in tolerant varieties contributing toward NaCl tolerance.
Wang, Zhuoran; Zhao, Gengxing; Gao, Mingxiu; Chang, Chunyan
2017-02-01
The objectives of this study were to explore the spatial variability of soil salinity in coastal saline soil at macro, meso and micro scales in the Yellow River delta, China. Soil electrical conductivities (ECs) were measured at 0-15, 15-30, 30-45 and 45-60 cm soil depths at 49 sampling sites during November 9 to 11, 2013. Soil salinity was converted from soil ECs based on laboratory analyses. Our results indicated that at the macro scale, soil salinity was high with strong variability in each soil layer, and the content increased and the variability weakened with increasing soil depth. From east to west in the region, the farther away from the sea, the lower the soil salinity was. The degrees of soil salinization in three deeper soil layers are 1.14, 1.24 and 1.40 times higher than that in the surface soil. At the meso scale, the sequence of soil salinity in different topographies, soil texture and vegetation decreased, respectively, as follows: depression >flatland >hillock >batture; sandy loam >light loam >medium loam >heavy loam >clay; bare land >suaeda salsa >reed >cogongrass >cotton >paddy >winter wheat. At the micro scale, soil salinity changed with elevation in natural micro-topography and with anthropogenic activities in cultivated land. As the study area narrowed down to different scales, the spatial variability of soil salinity weakened gradually in cultivated land and salt wasteland except the bare land.
Effects of salinity on growth and ion regulation of juvenile alligator gar Atractosteus spatula.
Schwarz, Daniel E; Allen, Peter J
2014-03-01
The alligator gar (Atractosteus spatula) is a primitive euryhaline fish, found primarily in estuaries and freshwater drainages associated with the northern Gulf of Mexico. The extent of its hypo-osmotic regulatory abilities is not well understood. In order to determine how salinity affects growth rates and ionic and osmoregulation, juvenile alligator gar (330 days after hatch; 185 g) were exposed to 4 different salinities (0, 8, 16, and 24 ppt) for a 30-day period. Specific growth rate, plasma osmolality and ion concentrations, gill and gastrointestinal tract Na(+), K(+)-ATPase activities, and drinking rate were compared. Juvenile alligator gar were able to tolerate hyperosmotic salinities up to 24 ppt for a 30 day period, albeit with decreased growth resulting largely from decreased food consumption. Plasma osmolality and ionic concentrations were elevated in hyperosmotic salinities, and drinking rates and gastrointestinal tract Na(+), K(+)-ATPase activities increased, particularly in the pyloric caeca, presumably the primary location of water absorption. Therefore, juvenile alligator gar<1 year of age are capable of prolonged exposure to hyperosmotic salinities, but, based on the inference of these data, require access to lower salinities for long-term survival. Copyright © 2013 Elsevier Inc. All rights reserved.
Bhat, Shirish; Motz, Louis H; Pathak, Chandra; Kuebler, Laura
2015-01-01
A geostatistical method was applied to optimize an existing groundwater-level monitoring network in the Upper Floridan aquifer for the South Florida Water Management District in the southeastern United States. Analyses were performed to determine suitable numbers and locations of monitoring wells that will provide equivalent or better quality groundwater-level data compared to an existing monitoring network. Ambient, unadjusted groundwater heads were expressed as salinity-adjusted heads based on the density of freshwater, well screen elevations, and temperature-dependent saline groundwater density. The optimization of the numbers and locations of monitoring wells is based on a pre-defined groundwater-level prediction error. The newly developed network combines an existing network with the addition of new wells that will result in a spatial distribution of groundwater monitoring wells that better defines the regional potentiometric surface of the Upper Floridan aquifer in the study area. The network yields groundwater-level predictions that differ significantly from those produced using the existing network. The newly designed network will reduce the mean prediction standard error by 43% compared to the existing network. The adoption of a hexagonal grid network for the South Florida Water Management District is recommended to achieve both a uniform level of information about groundwater levels and the minimum required accuracy. It is customary to install more monitoring wells for observing groundwater levels and groundwater quality as groundwater development progresses. However, budget constraints often force water managers to implement cost-effective monitoring networks. In this regard, this study provides guidelines to water managers concerned with groundwater planning and monitoring.
He, F
2014-04-25
Prenatal exposure to ethanol has been shown to increase the risk of anxiety in offspring. Here, we tested the effect of prenatal ethanol exposure on adult male mandarin voles (Microtus mandarinus). We examined anxiety-like behavior in the open field and elevated plus-maze tests in males exposed to ethanol prenatally. One control group was not exposed to ethanol or saline, while another control group was exposed to saline. At the age of 90days, males were tested and levels of serum testosterone, androgen receptor immunoreactive neurons (AR-IRs) and arginine vasopressin immunoreactive neurons (AVP-IRs) were measured. Animals exposed to ethanol spent less time in the center of the chamber, covered less distance and conducted fewer crossings in the open-field test. These animals also spent less time and conducted fewer crossings in the open arms. However, they spent more time and made more entries in the closed arms, and traveled less total distance during the elevated plus-maze test, compared to the control voles. Serum T was lower in the ethanol group, and the AR-IR number in the bed nucleus of the stria terminalis (BNST), medial preoptic area (mPOA) and medial amygdaloid nucleus (MeA) was significantly lower. The number of AVP-IRs in the paraventricular nucleus (PVN) and supraoptic nucleus (SON) of the ethanol group was higher than that of the control groups. Our findings suggest that prenatal ethanol exposure may lead to reduced serum T levels, decreased AR and increased AVP in the CNS and result in the development of anxiety-like behaviors. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.
The Effect of Geraniol on Liver Regeneration Αfter Hepatectomy in Rats
CANBEK, MEDIHA; UYANOGLU, MUSTAFA; CANBEK, SELCUK; CEYHAN, EMRE; OZEN, AHMET; DURMUS, BASAK; TURGAK, OZGE
2017-01-01
Geraniol is a monoterpenoid alcohol that has a hepatoprotective effect. We investigated the regenerative effects of geraniol in rats after a 70% partial hepatectomy (PH). Using Wistar albino rats, nine groups were created: Group I was the control group, while the remaining groups received a single intraperitoneal dose of saline, Silymarin, or geraniol after PH. A 70% PH was performed on all groups except for groups II and III. Blood serum samples were obtained for alanine amino transferase (ALT) analysis. Then liver tissues were harvested for histological and real-time polymerase chain reaction (PCR) analyses. Tumor necrosis factor-α (TNFα) and interleukin 6 (IL6) gene expression were examined 24 and 48 h after PH. ALT levels were found to be statistically significantly increased in all PH-treated groups. TNFα and IL6 gene expression levels were elevated in geraniol-treated groups. Histological evaluation revealed a hepatoprotective effect for geraniol-treated groups. Our results suggest that geraniol plays a significant role during liver regeneration, which involves the elevated expression of TNFα and IL6 48 h after PH. PMID:28358702
Vidyashankar, S; Deviprasad, K; Chauhan, V S; Ravishankar, G A; Sarada, R
2013-09-01
Five indigenous microalgal strains of Scenedesmus, Chlorococcum, Coelastrum, and Ankistrodesmus genera, isolated from Indian fresh water habitats, were studied for carbon-dioxide tolerance and its effect on growth, lipid and fatty acid profile. Scenedesmus dimorphus strain showed maximum growth (1.5 g/L) and lipid content (17.83% w/w) under CO2 supplementation, hence selected for detailed evaluation. The selected strain was alkaline adapted but tolerated (i) wide range of pH (5-11); (ii) elevated salinity levels (up to 100 mM, NaCl) with low biomass yields and increased carotenoids (19.34 mg/g biomass); (iii) elevated CO2 levels up to 15% v/v with enhancement in specific growth rate (0.137 d(-1)), biomass yield (1.57 g/L), lipid content (19.6% w/w) and CO2 biofixation rate (0.174 g L(-1) d(-1)). Unsaturated fatty acid content (alpha linolenic acid) increased with CO2 supplementation in the strain. Copyright © 2013 Elsevier Ltd. All rights reserved.
NASA Astrophysics Data System (ADS)
Kneafsey, T. J.; Flemings, P. B.; Bryant, S. L.; You, K.; Polito, P. J.
2013-12-01
Global climate change will cause warming of the oceans and land. This will affect the occurrence, behavior, and location of subseafloor and subterranean methane hydrate deposits. We suggest that in many natural systems local salinity, elevated by hydrate formation or freshened by hydrate dissociation, may control gas transport through the hydrate stability zone. We are performing experiments and modeling the experiments to explore this behavior for different warming scenarios. Initially, we are exploring hydrate association/dissociation in saline systems with constant water mass. We compare experiments run with saline (3.5 wt. %) water vs. distilled water in a sand mixture at an initial water saturation of ~0.5. We increase the pore fluid (methane) pressure to 1050 psig. We then stepwise cool the sample into the hydrate stability field (~3 degrees C), allowing methane gas to enter as hydrate forms. We measure resistivity and the mass of methane consumed. We are currently running these experiments and we predict our results from equilibrium thermodynamics. In the fresh water case, the modeled final hydrate saturation is 63% and all water is consumed. In the saline case, the modeled final hydrate saturation is 47%, the salinity is 12.4 wt. %, and final water saturation is 13%. The fresh water system is water-limited: all the water is converted to hydrate. In the saline system, pore water salinity is elevated and salt is excluded from the hydrate structure during hydrate formation until the salinity drives the system to three phase equilibrium (liquid, gas, hydrate) and no further hydrate forms. In our laboratory we can impose temperature gradients within the column, and we will use this to investigate equilibrium conditions in large samples subjected to temperature gradients and changing temperature. In these tests, we will quantify the hydrate saturation and salinity over our meter-long sample using spatially distributed temperature sensors, spatially distributed resistivity probes, compressional wave velocities, and X-ray computed tomography scanning. Modeling of hydrate formation and dissociation for these conditions indicates that the transport of bulk fluid phases (gas and water) plays a crucial role in the overall behavior, and we will explore open-system boundary conditions in the experiments to test this prediction.
NASA Astrophysics Data System (ADS)
Han, Dongmei; Post, Vincent E. A.; Song, Xianfang
2015-12-01
Seawater intrusion (SWI) has led to salinization of fresh groundwater reserves in coastal areas worldwide and has forced the closure of water supply wells. There is a paucity of well-documented studies that report on the reversal of SWI after the closure of a well field. This study presents data from the coastal carbonate aquifer in northeast China, where large-scale extraction has ceased since 2001 after salinization of the main well field. The physical flow and concomitant hydrogeochemical processes were investigated by analyzing water level and geochemical data, including major ion chemistry and stable water isotope data. Seasonal water table and salinity fluctuations, as well as changes of δ2H-δ18O values of groundwater between the wet and dry season, suggest local meteoric recharge with a pronounced seasonal regime. Historical monitoring testifies of the reversibility of SWI in the carbonate aquifer, as evidenced by a decrease of the Cl- concentrations in groundwater following restrictions on groundwater abstraction. This is attributed to the rapid flushing in this system where flow occurs preferentially along karst conduits, fractures and fault zones. The partially positive correlation between δ18O values and TDS concentrations of groundwater, as well as high NO3- concentrations (>39 mg/L), suggest that irrigation return flow is a significant recharge component. Therefore, the present-day elevated salinities are more likely due to agricultural activities rather than SWI. Nevertheless, seawater mixing with fresh groundwater cannot be ruled out in particular where formerly intruded seawater may still reside in immobile zones of the carbonate aquifer. The massive expansion of fish farming in seawater ponds in the coastal zone poses a new risk of salinization. Cation exchange, carbonate dissolution, and fertilizer application are the dominant processes further modifying the groundwater composition, which is investigated quantitatively using hydrogeochemical models.
Hakim, M. A.; Juraimi, Abdul Shukor; Hanafi, M. M.; Ismail, Mohd Razi; Selamat, Ahmad; Rafii, M. Y.; Latif, M. A.
2014-01-01
Five Malaysian rice (Oryza sativa L.) varieties, MR33, MR52, MR211, MR219, and MR232, were tested in pot culture under different salinity regimes for biochemical response, physiological activity, and grain yield. Three different levels of salt stresses, namely, 4, 8, and 12 dS m−1, were used in a randomized complete block design with four replications under glass house conditions. The results revealed that the chlorophyll content, proline, sugar content, soluble protein, free amino acid, and yield per plant of all the genotypes were influenced by different salinity levels. The chlorophyll content was observed to decrease with salinity level but the proline increased with salinity levels in all varieties. Reducing sugar and total sugar increased up to 8 dS m−1 and decreased up to 12 dS m−1. Nonreducing sugar decreased with increasing the salinity levels in all varieties. Soluble protein and free amino acid also decreased with increasing salinity levels. Cortical cells of MR211 and MR232 did not show cell collapse up to 8 dS m−1 salinity levels compared to susceptible checks (IR20 and BRRI dhan29). Therefore, considering all parameters, MR211 and MR232 showed better salinity tolerance among the tested varieties. Both cluster and principal component analyses depict the similar results. PMID:24579076
Hakim, M A; Juraimi, Abdul Shukor; Hanafi, M M; Ismail, Mohd Razi; Selamat, Ahmad; Rafii, M Y; Latif, M A
2014-01-01
Five Malaysian rice (Oryza sativa L.) varieties, MR33, MR52, MR211, MR219, and MR232, were tested in pot culture under different salinity regimes for biochemical response, physiological activity, and grain yield. Three different levels of salt stresses, namely, 4, 8, and 12 dS m(-1), were used in a randomized complete block design with four replications under glass house conditions. The results revealed that the chlorophyll content, proline, sugar content, soluble protein, free amino acid, and yield per plant of all the genotypes were influenced by different salinity levels. The chlorophyll content was observed to decrease with salinity level but the proline increased with salinity levels in all varieties. Reducing sugar and total sugar increased up to 8 dS m(-1) and decreased up to 12 dS m(-1). Nonreducing sugar decreased with increasing the salinity levels in all varieties. Soluble protein and free amino acid also decreased with increasing salinity levels. Cortical cells of MR211 and MR232 did not show cell collapse up to 8 dS m(-1) salinity levels compared to susceptible checks (IR20 and BRRI dhan29). Therefore, considering all parameters, MR211 and MR232 showed better salinity tolerance among the tested varieties. Both cluster and principal component analyses depict the similar results.
NASA Astrophysics Data System (ADS)
Salama, Ramsis B.
The River Nile in Sudan, was during the Tertiary, a series of closed lake basins. Each basin occupying one of the major Sudanese rift systems (Salama, 1985a). In this paper evidence is presented for the presence of the buried saline Sudd Lake in Bahr El Arab rift. The thick Tertiary sediments filling the deep grabens were eroded from the elevated blocks; Jebel Marra, Darfur Dome, Nuba Mountains and the Nile-Congo Divide. The thick carbonate deposits existing at the faulted boundaries of Bahr El Arab defines the possible boundaries between the fresh and saline water bodies. The widespread presence of kanker nodules in the sediments was a result of continuous efflorescence, leaching and evaporative processes. The highly saline zone in the central part of the Sudd was formed through the same processes with additional sulphate being added by the oxidation of the hydrogen sulphide gases emanating from the oil fields.
NASA Astrophysics Data System (ADS)
Galperin, Boris; Mellor, George L.
1990-09-01
The three-dimensional model of Delaware Bay, River and adjacent continental shelf was described in Part 1. Here, Part 2 of this two-part paper demonstrates that the model is capable of realistic simulation of current and salinity distributions, tidal cycle variability, events of strong mixing caused by high winds and rapid salinity changes due to high river runoff. The 25-h average subtidal circulation strongly depends on the wind forcing. Monthly residual currents and salinity distributions demonstrate a classical two-layer estuarine circulation wherein relatively low salinity water flows out at the surface and compensating high salinity water from the shelf flows at the bottom. The salinity intrusion is most vigorous along deep channels in the Bay. Winds can generate salinity fronts inside and outside the Bay and enhance or weaken the two-layer circulation pattern. Since the portion of the continental shelf included in the model is limited, the model shelf circulation is locally wind-driven and excludes such effects as coastally trapped waves and interaction with Gulf Stream rings; nevertheless, a significant portion of the coastal elevation variability is hindcast by the model. Also, inclusion of the shelf improves simulation of salinity inside the Bay compared with simulations where the salinity boundary condition is specified at the mouth of the Bay.
Doremus-Fitzwater, Tamara L.; Varlinskaya, Elena I.; Spear, Linda Patia
2011-01-01
The elevated plus-maze (EPM) is vulnerable to variations in pretest circumstances when testing adult rodents. Because of an increasing interest in adolescence, the present experiments examined the impact of pretest manipulations on anxiety levels in the EPM among adolescent and adult Sprague Dawley rats of both sexes. In Exp. 1, animals removed from their home cage and immediately placed on the EPM were compared to rats tested following 30 min of social isolation, or following 30-min exposure to a novel context. These pretest manipulations only modestly decreased anxiety levels at both ages. In Exp. 2, more varied pretest conditions were examined: testing directly from the home cage; testing following 30 min of social isolation in a novel environment; or a large saline injection and rehousing 18 h prior to a 30-min period of social isolation in a novelty situation before testing. In adults, anxiety levels decreased linearly as pretest perturbation increased, whereas adolescents showed comparable levels of anxiety with both the moderate and large perturbations. As a result, observed age differences in anxiety differed as a function of pretest circumstances. Therefore, caution is urged when using the EPM for across-age comparisons of anxiolytic and anxiogenic effects of pharmacological or other manipulations. PMID:19344672
Doremus-Fitzwater, Tamara L; Varlinskaya, Elena I; Spear, Linda Patia
2009-05-01
The elevated plus-maze (EPM) is vulnerable to variations in pretest circumstances when testing adult rodents. Because of an increasing interest in adolescence, the present experiments examined the impact of pretest manipulations on anxiety levels in the EPM among adolescent and adult Sprague-Dawley rats of both sexes. In Exp. 1, animals removed from their home cage and immediately placed on the EPM were compared to rats tested following 30 min of social isolation, or following 30-min exposure to a novel context. These pretest manipulations only modestly decreased anxiety levels at both ages. In Exp. 2, more varied pretest conditions were examined: testing directly from the home cage; testing following 30 min of social isolation in a novel environment; or a large saline injection and rehousing 18 h prior to a 30-min period of social isolation in a novelty situation before testing. In adults, anxiety levels decreased linearly as pretest perturbation increased, whereas adolescents showed comparable levels of anxiety with both the moderate and large perturbations. As a result, observed age differences in anxiety differed as a function of pretest circumstances. Therefore, caution is urged when using the EPM for across-age comparisons of anxiolytic and anxiogenic effects of pharmacological or other manipulations.
Response of salt marsh and mangrove wetlands to changes in atmospheric CO2, climate, and sea-level
Mckee, Karen L.; Rogers, Kerrylee; Saintilan, Neil; Middleton, Beth A.
2012-01-01
Coastal salt marsh and mangrove ecosystems are particularly vulnerable to changes in atmospheric CO2 concentrations and associated climate and climate-induced changes. We provide a review of the literature detailing theoretical predictions and observed responses of coastal wetlands to a range of climate change stressors, including CO2, temperature, rainfall, and sea-level rise. This review incorporates a discussion of key processes controlling responses in different settings and thresholds of resilience derived from experimental and observational studies. We specifically consider the potential and observed effects on salt marsh and mangrove vegetation of changes in (1) elevated [CO2] on physiology, growth, and distribution; (2) temperature on distribution and diversity; (3) rainfall and salinity regimes on growth and competitive interactions; and (4) sea level on geomorphological, hydrological, and biological processes.
Transcriptional responses of the rat vasopressin gene to acute and repeated acute osmotic stress.
Zemo, David A; McCabe, Joseph T
2002-09-01
To determine the impact of hypertonic saline administration upon rat arginine vasopressin (AVP) gene transcription in supraoptic nucleus neurons, a probe complementary to the first intron (AVP1) of AVP was used to measure changes in AVP heteronuclear RNA (hnRNA) levels. Animals that received hypertonic saline had increases in AVP1 after 15 and 30 min, with a return to baseline levels by 180 min. In a double injection paradigm, animals were given an injection of normal or hypertonic saline followed 180 min later by a second injection of normal or hypertonic saline and sacrificed 30 min later. When both injections were hypertonic saline (H-H), AVP1 levels were greater than levels seen after a single hypertonic saline injection, or after an injection of normal saline followed by a second injection of hypertonic saline (N-H). This study shows acute, repeated exposure to hypertonic saline causes a robust increase in vasopressin gene transcription. Since a second hyperosmotic stimulus is known to increase neuronal firing rate and activity, our results suggest that a correlation exists with intracellular mechanisms regulating vasopressin gene transcription.
Wood, Cameron; Harrington, Glenn A
2015-01-01
Seasonal variations in sea level are often neglected in studies of coastal aquifers; however, they may have important controls on processes such as submarine groundwater discharge, sea water intrusion, and groundwater discharge to coastal springs and wetlands. We investigated seasonal variations in salinity in a groundwater-fed coastal wetland (the RAMSAR listed Piccaninnie Ponds in South Australia) and found that salinity peaked during winter, coincident with seasonal sea level peaks. Closer examination of salinity variations revealed a relationship between changes in sea level and changes in salinity, indicating that sea level-driven movement of the fresh water-sea water interface influences the salinity of discharging groundwater in the wetland. Moreover, the seasonal control of sea level on wetland salinity seems to override the influence of seasonal recharge. A two-dimensional variable density model helped validate this conceptual model of coastal groundwater discharge by showing that fluctuations in groundwater salinity in a coastal aquifer can be driven by a seasonal coastal boundary condition in spite of seasonal recharge/discharge dynamics. Because seasonal variations in sea level and coastal wetlands are ubiquitous throughout the world, these findings have important implications for monitoring and management of coastal groundwater-dependent ecosystems. © 2014, National Ground Water Association.
Zhang, Xiaoying; Miao, Jinjie; Hu, Bill X; Liu, Hongwei; Zhang, Hanxiong; Ma, Zhen
2017-09-01
The aquifer in the coastal area of the Laizhou Bay is affected by salinization processes related to intense groundwater exploitation for brine resource and for agriculture irrigation during the last three decades. As a result, the dynamic balances among freshwater, brine, and seawater have been disturbed and the quality of groundwater has deteriorated. To fully understand the groundwater chemical distribution and evolution in the regional aquifers, hydrogeochemical and isotopic studies have been conducted based on the water samples from 102 observation wells. Groundwater levels and salinities in four monitoring wells are as well measured to inspect the general groundwater flow and chemical patterns and seasonal variations. Chemical components such as Na + , K + , Ca 2+ , Mg 2+ , Sr 2+ , Cl - , SO 4 2- , HCO 3 - , NO 3 - , F - , and TDS during the same period are analyzed to explore geochemical evolution, water-rock interactions, sources of salt, nitrate, and fluoride pollution in fresh, brackish, saline, and brine waters. The decreased water levels without typical seasonal variation in the southeast of the study area confirm an over-exploitation of groundwater. The hydrogeochemical characteristics indicate fresh-saline-brine-saline transition pattern from inland to coast where evaporation is a vital factor to control the chemical evolution. The cation exchange processes are occurred at fresh-saline interfaces of mixtures along the hydraulic gradient. Meanwhile, isotopic data indicate that the brine in aquifers was either originated from older meteoric water with mineral dissolution and evaporation or repeatedly evaporation of retained seawater with fresher water recharge and mixing in geological time. Groundwater suitability for drinking is further evaluated according to water quality standard of China. Results reveal high risks of nitrate and fluoride contamination. The elevated nitrate concentration of 560 mg/L, which as high as 28 times of the standard content in drinking water is identified in the south region. In addition, the nitrate and ammonia data of the Wei River suggests decreasing nitrification rate in the study area from inland to estuary. High fluoride concentration, larger than 1 mg/L, is also detected in an area of about 50% of the study region. The saltwater intrusion is analyzed to be responsible for part of dissolution of minerals containing fluoride. Therefore, water treatment before drinking is needed in urgent to reduce the health expose risk.
Rhee, Jae-Sung; Kim, Bo-Mi; Seo, Jung Soo; Kim, Il-Chan; Lee, Young-Mi; Lee, Jae-Seong
2012-04-01
Salinity is an important parameter that affects survival and metabolism in fish. In fish, pituitary growth hormone (GH) regulates physiological functions including adaptation to different salinity as well as somatic growth. GH is stimulated by growth hormone-releasing hormone (GHRH) and exerts its function via binding to growth hormone receptor (GHR). As Kryptolebias marmoratus is a euryhaline fish, this species would be a useful model species for studying the adaptation to osmotic stress conditions. Here, we cloned GH, -GHR, somatolactin (SL), and somatolactin receptor (SLR) genes, and analyzed their expression patterns in different tissues and during early developmental stages by using real-time RT-PCR. We also further examined expression of them after acclimation to different salinity. Tissue distribution studies revealed that Km-GH and -SL mRNAs were remarkably expressed in brain and pituitary, whereas Km-GHR and -SLR mRNAs were predominantly expressed in liver, followed by gonad, muscle, pituitary, and brain. During embryonic developmental stages, the expression of their mRNA was increased at stage 3 (9 dpf). The Km-GH and -SL mRNA transcripts were constantly elevated until stage 5 (5h post hatch), whereas Km-GHR and -SLR mRNA levels decreased at this stage. After we transferred K. marmoratus from control (12 psu) to hyper-osmotic condition (hyperseawater, HSW; 33 psu), Km-GH, -SL, and GHR mRNA levels were enhanced. In hypo-osmotic conditions like freshwater (FW), Km-GH and -SL expressions were modulated 24 h after exposure, and Km-SLR transcripts were significantly upregulated. This finding suggests that Km-GH and -SL may be involved in the osmoregulatory mechanism under hyper-osmotic as well as hypo-osmotic stress. This is the first report on transcriptional modulation and relationship of GH, GHR, SL, and SLR during early development and after salinity stress. This study will be helpful to a better understanding on molecular mechanisms of adaptation response to salt stress in euryhaline fish. Copyright © 2012 Elsevier Inc. All rights reserved.
High salinity facilitates dolomite precipitation mediated by Haloferax volcanii DS52
NASA Astrophysics Data System (ADS)
Qiu, Xuan; Wang, Hongmei; Yao, Yanchen; Duan, Yong
2017-08-01
Although most modern dolomites occur in hypersaline environments, the effects of elevated salinity on the microbial mediation of dolomite precipitation have not been fully evaluated. Here we report results of dolomite precipitation in association with a batch culture of Haloferax volcanii DS52, a halophilic archaeon, under various salinities (from 120‰ to 360‰) and the impact of salinity on microbe-mediated dolomite formation. The mineral phases, morphology and atomic arrangement of the precipitates were analyzed by XRD, SEM and TEM, respectively. The amount of amino acids on the archaeal cell surface was quantified by HPLC/MS. The XRD analysis indicated that disordered dolomite formed successfully with the facilitation of cells harvested from cultures with relatively high salinities (200‰ and 280‰) but was not observed in association with cells harvested from cultures with lower salinity (120‰) or the lysates of cells harvested from extremely high salinity (360‰). The TEM analysis demonstrated that the crystals from cultures with a salinity of 200‰ closely matched that of dolomite. Importantly, we found that more carboxyl groups were presented on the cell surface under high salinity conditions to resist the high osmotic pressure, which may result in the subsequent promotion of dolomite formation. Our finding suggests a link between variations in the hydro-chemical conditions and the formation of dolomite via microbial metabolic activity and enhances our understanding about the mechanism of microbially mediated dolomite formation under high salinity conditions.
Gleadow, Ros; Pegg, Amelia; Blomstedt, Cecilia K.
2016-01-01
Rising sea levels are threatening agricultural production in coastal regions due to inundation and contamination of groundwater. The development of more salt-tolerant crops is essential. Cassava is an important staple, particularly among poor subsistence farmers. Its tolerance to drought and elevated temperatures make it highly suitable for meeting global food demands in the face of climate change, but its ability to tolerate salt is unknown. Cassava stores nitrogen in the form of cyanogenic glucosides and can cause cyanide poisoning unless correctly processed. Previous research demonstrated that cyanide levels are higher in droughted plants, possibly as a mechanism for increasing resilience to oxidative stress. We determined the tolerance of cassava to salt at two different stages of development, and tested the hypothesis that cyanide toxicity would be higher in salt-stressed plants. Cassava was grown at a range of concentrations of sodium chloride (NaCl) at two growth stages: tuber initiation and tuber expansion. Established plants were able to tolerate 100mM NaCl but in younger plants 40mM was sufficient to retard plant growth severely. Nutrient analysis showed that plants were only able to exclude sodium at low concentrations. The foliar cyanogenic glucoside concentration in young plants increased under moderate salinity stress but was lower in plants grown at high salt. Importantly, there was no significant change in the cyanogenic glucoside concentration in the tubers. We propose that the mechanisms for salinity tolerance are age dependent, and that this can be traced to the relative cost of leaves in young and old plants. PMID:27506218
Fridman, Sophie; Rana, Krishen J; Bron, James E
2013-10-01
Aspects of ionoregulatory or mitochondria-rich cell (MRC) differentiation and adaptation in Nile tilapia yolk-sac larvae following transfer from freshwater to elevated salinities, that is, 12.5 and 20 ppt are described. Investigations using immunohistochemistry on whole-mount Nile tilapia larvae using anti- Na⁺/K⁺-ATPase as a primary antibody and Fluoronanogold™ (Nanoprobes) as a secondary immunoprobe allowed fluorescent labeling with the high resolution of confocal scanning laser microscopy combined with the detection of immunolabeled target molecules at an ultrastructural level using transmission electron microscopy (TEM). It reports, for the first time, various developmental stages of MRCs within the epithelial layer of the tail of yolk-sac larvae, corresponding to immature, developing, and mature MRCs, identifiable by their own characteristic ultrastructure and form. Following transfer to hyperosmotic salinities the density of immunogold particles and well as the intricacy of the tubular system appeared to increase. In addition, complementary confocal scanning laser microscopy allowed identification of immunopositive ramifying extensions that appeared to emanate from the basolateral portion of the cell that appeared to be correlated with the localization of subsurface tubular areas displaying immunogold labeled Na⁺/K⁺-ATPase. This integrated approach describes a reliable and repeatable prefixation immunogold labeling technique allowing precise visualization of NaK within target cells combined with a 3D imaging that offers valuable insights into MRC dynamics at an ultrastructural level. Copyright © 2013 Wiley Periodicals, Inc.
Zhong, Zhi-Ping; Liu, Ying; Miao, Li-Li; Wang, Fang; Chu, Li-Min; Wang, Jia-Li
2016-01-01
The prokaryotic community composition and diversity and the distribution patterns at various taxonomic levels across gradients of salinity and physiochemical properties in the surface waters of seven plateau lakes in the Qaidam Basin, Tibetan Plateau, were evaluated using Illumina MiSeq sequencing. These lakes included Lakes Keluke (salinity, <1 g/liter), Qing (salinity, 5.5 to 6.6 g/liter), Tuosu (salinity, 24 to 35 g/liter), Dasugan (salinity, 30 to 33 g/liter), Gahai (salinity, 92 to 96 g/liter), Xiaochaidan (salinity, 94 to 99 g/liter), and Gasikule (salinity, 317 to 344 g/liter). The communities were dominated by Bacteria in lakes with salinities of <100 g/liter and by Archaea in Lake Gasikule. The clades At12OctB3 and Salinibacter, previously reported only in hypersaline environments, were found in a hyposaline lake (salinity, 5.5 to 6.6 g/liter) at an abundance of ∼1.0%, indicating their ecological plasticity. Salinity and the concentrations of the chemical ions whose concentrations covary with salinity (Mg2+, K+, Cl−, Na+, SO42−, and Ca2+) were found to be the primary environmental factors that directly or indirectly determined the composition and diversity at the level of individual clades as well as entire prokaryotic communities. The distribution patterns of two phyla, five classes, five orders, five families, and three genera were well predicted by salinity. The variation of the prokaryotic community structure also significantly correlated with the dissolved oxygen concentration, pH, the total nitrogen concentration, and the PO43− concentration. Such correlations varied depending on the taxonomic level, demonstrating the importance of comprehensive correlation analyses at various taxonomic levels in evaluating the effects of environmental variable factors on prokaryotic community structures. Our findings clarify the distribution patterns of the prokaryotic community composition in plateau lakes at the levels of individual clades as well as whole communities along gradients of salinity and ionic concentrations. PMID:26746713
The hydrogeochemistry of argillaceous rock formations at the Horonobe URL site, Japan
NASA Astrophysics Data System (ADS)
Hama, K.; Kunimaru, T.; Metcalfe, R.; Martin, A. J.
A hydrogeochemical investigation is being carried out as part of the Horonobe underground research laboratory (URL) project in Japan. The main aims are to: (1) investigate an actual example of a geological environment in a sedimentary rock formation in Japan; and (2) to confirm the reliability of generic technologies that may in future be applied during the geological disposal of high level radioactive waste. The main rock formations being characterized are the marine Wakkanai and Koetoi Formations (Miocene to Pliocene), consisting dominantly of siliceous shales (porcelanites) and diatomaceous shales respectively. These formations are located within the Tempoku Basin, within a back-arc tectonic setting. Rock sequences of this kind occur widely in Japan and throughout the northern Pacific region. However, prior to the present study, there was relatively little information concerning the processes controlling in situ chemical conditions and groundwater flow in such settings. Chemical data was obtained for both pumped waters and squeezed porewaters in order to characterize the hydrogeochemistry of these argillaceous rock formations. The in situ chemical conditions, residence time of the groundwaters and the evolution processes of the groundwaters were investigated. Generally, at each locality studied, shallower groundwaters are fresh and have Na-HCO 3 dominated chemistry. Deeper groundwaters are saline (TDS up to about 22,000 mg/l) and have Na-Cl dominated chemistry. However, lateral gradients in salinity are also recognized, with salinity contours in the Na-Cl dominated saline water (having TDS > 10,000 mg/l) probably varying in elevation by at least 250 m. Further investigations are required to confirm the origins of the groundwater salinity, but the Na-Cl dominated groundwater chemistry is provisionally explained as a consequence of the dilution of fossil seawater, accompanied by diagenetic water-rock reactions. The vertical and lateral salinity gradients can potentially be used to test the validity of coupled groundwater flow models. A conceptual model is tentatively suggested in which the spatial distribution and frequency of fractures helps to control the spatial distribution of groundwater salinity. Future investigations will clarify the timing of flow, the flow directions and the characteristics of the flow paths.
Li, Xiaojuan; Guo, Chengjin; Gu, Juntao; Duan, Weiwei; Zhao, Miao; Ma, Chunying; Du, Xiaoming; Lu, Wenjing; Xiao, Kai
2014-02-01
Establishing crop cultivars with strong tolerance to P and N deprivation, high salinity, and drought is an effective way to improve crop yield and promote sustainable agriculture worldwide. A vacuolar H+-pyrophosphatase (V-H+-PPase) gene in wheat (TaVP) was functionally characterized in this study. TaVP cDNA is 2586-bp long and encodes a 775-amino-acid polypeptide that contains 10 conserved membrane-spanning domains. Transcription of TaVP was upregulated by inorganic phosphate (Pi) and N deprivation, high salinity, and drought. Transgene analysis revealed that TaVP overexpression improved plant growth under normal conditions and specifically under Pi and N deprivation stresses, high salinity, and drought. The improvement of growth of the transgenic plants was found to be closely related to elevated V-H+-PPase activities in their tonoplasts and enlarged root systems, which possibly resulted from elevated expression of auxin transport-associated genes. TaVP-overexpressing plants showed high dry mass, photosynthetic efficiencies, antioxidant enzyme activities, and P, N, and soluble carbohydrate concentrations under various growth conditions, particularly under the stress conditions. The transcription of phosphate and nitrate transporter genes was not altered in TaVP-overexpressing plants compared with the wild type, suggesting that high P and N concentrations regulated by TaVP were caused by increased root absorption area instead of alteration of Pi and NO3- acquisition kinetics. TaVP is important in the tolerance of multiple stresses and can serve as a useful genetic resource to improve plant P- and N-use efficiencies and to increase tolerance to high salinity and drought.
NASA Astrophysics Data System (ADS)
van Soelen, Elsbeth E.; Twitchett, Richard J.; Kürschner, Wolfram M.
2018-04-01
The late Permian biotic crisis had a major impact on marine and terrestrial environments. Rising CO2 levels following Siberian Trap volcanic activity were likely responsible for expanding marine anoxia and elevated water temperatures. This study focuses on one of the stratigraphically most expanded Permian-Triassic records known, from Jameson Land, East Greenland. High-resolution sampling allows for a detailed reconstruction of the changing environmental conditions during the extinction event and the development of anoxic water conditions. Since very little is known about how salinity was affected during the extinction event, we especially focus on the aquatic palynomorphs and infer changes in salinity from changes in the assemblage and morphology. The start of the extinction event, here defined by a peak in spore : pollen, indicating disturbance and vegetation destruction in the terrestrial environment, postdates a negative excursion in the total organic carbon, but predates the development of anoxia in the basin. Based on the newest estimations for sedimentation rates, the marine and terrestrial ecosystem collapse took between 1.6 and 8 kyr, a much shorter interval than previously estimated. The palynofacies and palynomorph records show that the environmental changes can be explained by enhanced run-off and increased primary productivity and water column stratification. A lowering in salinity is supported by changes in the acritarch morphology. The length of the processes of the acritarchs becomes shorter during the extinction event and we propose that these changes are evidence for a reduction in salinity in the shallow marine setting of the study site. This inference is supported by changes in acritarch distribution, which suggest a change in palaeoenvironment from open marine conditions before the start of the extinction event to more nearshore conditions during and after the crisis. In a period of sea-level rise, such a reduction in salinity can only be explained by increased run-off. High amounts of both terrestrial and marine organic fragments in the first anoxic layers suggest that high run-off, increased nutrient availability, possibly in combination with soil erosion, are responsible for the development of anoxia in the basin. Enhanced run-off could result from changes in the hydrological cycle during the late Permian extinction event, which is a likely consequence of global warming. In addition, vegetation destruction and soil erosion may also have resulted in enhanced run-off. Salinity stratification could potentially explain the development of anoxia in other shallow marine sites. The input of freshwater and related changes in coastal salinity could also have implications for the interpretation of oxygen isotope records and seawater temperature reconstructions at some sites.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Pillard, D.A.; DuFresne, D.L.; Caudle, D.D.
2000-01-01
Although marine organisms are naturally adapted to salinities well above those of freshwater, elevated concentrations of specific ions have been shown to cause adverse effects on some saltwater species. Because some ions are also physiologically essential, a deficiency of these ions can also cause significant effects. To provide a predictive tool to assess toxicity associated with major ions, mysid shrimp (Mysidopsis bahia), sheepshead minnows (Cyprinodon variegatus), and inland silverside minnows (Menidia beryllina) were exposed to saline solutions containing calcium, magnesium, potassium, strontium, bicarbonate, borate, bromide, and sulfate at concentrations above and below what would be found in seawater. Solution salinitymore » was maintained at approximately 31% by increasing or decreasing sodium and chloride concentrations. Logistic regression models were developed with both the ion molar concentrations and ion activity. Toxicity to all three species was observed when either a deficiency or an excess of potassium and calcium occurred. Significant mortality occurred in all species when exposed to excess concentrations of magnesium, bicarbonate, and borate. The response to the remaining ions varied with species. Sheepshead minnows were the most tolerant of both deficient and elevated levels of the different ions. Mysid shrimp and inland silverside minnows demonstrated similar sensitivities to several ions, but silverside minnow response was more variable. As a result, the logistic models that predict inland silverside minnow survival generally were less robust than for the other two species.« less
NASA Astrophysics Data System (ADS)
Bertoni, E.; Bertello, L.; Capotondi, L.; Bergami, C.; Giglio, F.; Ravaioli, M.; Rossi, C.; Ferretti, A.
2012-04-01
This study, present data on benthic foraminiferal assemblages from four box cores collected in different areas of the Ross Sea during the 2005 oceanographic cruise in the framework of the Italian Antarctic Research National Programme (PNRA). Based on magnetic susceptibility, biosiliceous content, and micropaleontological analysis, the sediment cores provide a record of glacial retreat and Holocene environmental changes in the Ross Sea during the last 11 kyr BP. Sediment lithologies range between diamicton to surficial diatomaceous mud, the intermediate levels being glacial-marine sediment. The sedimentary sections include diatomaceous glacial-marine deposit over transitional (proximal grounding zone) glacial-marine sediment. The study revealed that the Ross Sea contains typical Antarctic foraminifera fauna with the dominance of agglutinated taxa. Relatively elevated abundances, richness and diversity were common in the northernmost site, where the water column was characterized by relatively warmer intermediate waters and by the presence of the colder High Salinity Shelf Water (HSSW) occupying the deepest part of the basin. Here, the assemblage was dominated by Miliammina arenacea and the more abundant species were Trochammina quadricamerata and Lagenammina difflugiformis. In the southernmost site and in the eastern Ross Sea, richness and diversity were low and the most significant species were Trochammina sp., and Reophax sp. M. arenacea was ubiquitous in all the samples and sites, confirming its tolerance to cold corrosive bottom waters and salinity fluctuations as well as its uniquely high preservation potential. Moreover, elevated abundances, richness and diversity were common in the upper portion of the core which represents the youngest climatic phase characterized by the presence of some calcareous specimens too. This may indicate a deeper Carbonate Compensation Depth, probably due to relatively stable and warmer environmental conditions. Results document that diversity of benthic foraminifera, number of specimens and variations in test morphology are related to regional differences in water properties (temperature, salinity, carbonate chemistry).
Lin, Qiuqi; Xu, Lei; Hou, Juzhi; Liu, Zhengwen; Jeppesen, Erik; Han, Bo-Ping
2017-11-01
Warming has pronounced effects on lake ecosystems, either directly by increased temperatures or indirectly by a change in salinity. We investigated the current status of zooplankton communities and trophic structure in 45 Tibetan lakes along a 2300 m altitude and a 76 g/l salinity gradient. Freshwater to hyposaline lakes mainly had three trophic levels: phytoplankton, small zooplankton and fish/Gammarus, while mesosaline to hypersaline lakes only had two: phytoplankton and large zooplankton. Zooplankton species richness declined significantly with salinity, but did not relate with temperature. Furthermore, the decline in species richness with salinity in lakes with two trophic levels was much less abrupt than in lakes with three trophic levels. The structural variation of the zooplankton community depended on the length of the food chain, and was significantly explained by salinity as the critical environmental variable. The zooplankton community shifted from dominance of copepods and small cladoceran species in the lakes with low salinity and three trophic levels to large saline filter-feeding phyllopod species in those lakes with high salinity and two trophic levels. The zooplankton to phytoplankton biomass ratio was positively related with temperature in two-trophic-level systems and vice versa in three-trophic-level systems. As the Tibetan Plateau is warming about three times faster than the global average, our results imply that warming could have a considerable impact on the structure and function of Tibetan lake ecosystems, either via indirect effects of salinization/desalinization on species richness, composition and trophic structure or through direct effects of water temperature on trophic interactions. Copyright © 2017 Elsevier Ltd. All rights reserved.
Reactive oxygen species dynamics in roots of salt sensitive and salt tolerant cultivars of rice.
Saini, Shivani; Kaur, Navdeep; Pati, Pratap Kumar
2018-06-01
Salinity stress is one of the major constraints for growth and survival of plants that affects rice productivity worldwide. Hence, in the present study, roots of two contrasting salinity sensitive cultivars, IR64 (IR64, salt sensitive) and Luna Suvarna (LS, salt tolerant) were compared with regard to the levels of reactive oxygen species (ROS) to derive clues for their differential salt stress adaptation mechanisms. In our investigation, the tolerant cultivar exhibited longer primary roots, more lateral roots, higher root number leading to increased root biomass, with respect to IR64. It was observed that LS roots maintained higher level of H 2 O 2 in comparison to IR64. The activities of various enzymes involved in enzymatic antioxidant defense mechanism (SOD, CAT, GPX, DHAR and MDHAR) were found to be greater in LS roots. Further, the higher transcript level accumulation of genes encoding ROS generating (RbohA, RbohD and RbohE) and scavenging enzymes (Fe-SOD, Chloroplastic Cu/Zn-SOD, CAT and DHAR) were noticed in the roots of tolerant cultivar, LS. Moreover, the content of other stress markers such as total protein and proline were also elevated in LS roots. While, the expression of proline biosynthesis gene (P5CS) and proline catabolism gene (PDH) was observed to be lower in LS. Copyright © 2018. Published by Elsevier Inc.
Taurine protects against methotrexate-induced toxicity and inhibits leukocyte death
DOE Office of Scientific and Technical Information (OSTI.GOV)
Cetiner, Mustafa; Sener, Goeksel; Sehirli, A. Ozer
2005-11-15
The efficacy of methotrexate (MTX), a widely used cytotoxic chemotherapeutic agent, is often limited by severe side effects and toxic sequelae. Regarding the mechanisms of these side effects, several hypotheses have been put forward, among which oxidative stress is noticeable. The present study was undertaken to determine whether taurine, a potent free radical scavenger, could ameliorate MTX-induced oxidative injury and modulate immune response. Following a single dose of methotrexate (20 mg/kg), either saline or taurine (50 mg/kg) was administered for 5 days. After decapitation of the rats, trunk blood was obtained and the ileum, liver, and kidney were removed tomore » measure malondialdehyde (MDA) and glutathione (GSH) levels, myeloperoxidase (MPO) activity, and collagen content, as well as histological examination. Our results showed that MTX administration increased the MDA, MPO activity, and collagen contents and decreased GSH levels in all tissues (P < 0.001), while these alterations were reversed in taurine-treated group (P < 0.05-0.01). Elevated (P < 0.001) TNF-{alpha} level observed following MTX treatment was depressed with taurine (P < 0.01). Oxidative burst of neutrophils stimulated by phorbol myristate acetate was reduced in saline-treated MTX group (P < 0.001), while taurine abolished this effect. Similarly, flow cytometric measurements revealed that leukocyte apoptosis and cell death were increased in MTX-treated animals, while taurine reversed these effects (P < 0.05). Reduced cellularity in bone marrow samples of MTX-treated group (P < 0.01) was reversed back to control levels in taurine-treated rats. Severe degeneration of the intestinal mucosa, liver parenchyma, glomerular, and tubular epithelium observed in saline-treated group was improved by taurine treatment. In conclusion, it appears that taurine protects against methotrexate-induced oxidant organ injury and inhibits leukocyte apoptosis and may be of therapeutic potential in alleviating the systemic side effects of chemotherapeutics.« less
Rendon, Samuel H.; Lee, Michael T.
2015-12-08
Lake Houston, an important water resource for the Houston, Texas, area, receives inflows from seven major tributaries that compose the San Jacinto River Basin upstream from the reservoir. The effects of different inflows from the watersheds drained by these tributaries on the residence time of water in Lake Houston and closely associated physical and chemical properties including lake elevation, salinity, and water temperature are not well known. Accordingly, the U.S. Geological Survey (USGS), in cooperation with the City of Houston, developed a three-dimensional hydrodynamic model of Lake Houston as a tool for evaluating the effects of different inflows on residence time of water in the lake and associated physical and chemical properties. The Environmental Fluid Dynamics Code (EFDC), a grid-based, surface-water modeling package for simulating three-dimensional circulation, mass transport, sediments, and biogeochemical processes, was used to develop the model of Lake Houston. The Lake Houston EFDC model was developed and calibrated by using 2009 data and verified by using 2010 data. Three statistics (mean error, root mean square error, and the Nash-Sutcliffe model efficiency coefficient) were used to evaluate how well the Lake Houston EFDC model simulated lake elevation, salinity, and water temperature. The residence time of water in reservoirs is associated with various physical and chemical properties (including lake elevation, salinity, and water temperature). Simulated and measured lake-elevation values were compared at USGS reservoir station 08072000 Lake Houston near Sheldon, Tex. The accuracy of simulated salinity and water temperature values was assessed by using the salinity (computed from measured specific conductance) and water temperature at two USGS monitoring stations: 295826095082200 Lake Houston south Union Pacific Railroad Bridge near Houston, Tex., and 295554095093401 Lake Houston at mouth of Jack’s Ditch near Houston, Tex. Specific conductance and water temperature were measured at as many as four different depths at each of the two monitoring stations during 2009 and then used for assessing the accuracy of simulated values of salinity and water temperature during 2010. The performance evaluation statistics indicate that the model performed satisfactorily. The calibrated model was used to simulate two possible inflow scenarios to evaluate the changes in the residence time of water in Lake Houston. The two scenarios tested were an increased inflow of approximately 300 cubic feet per second for 1 month (May 2010) from two watersheds: the West Fork San Jacinto River and Luce Bayou. These scenarios were chosen to mimic the effects of possible small releases or diversions of water from outside the San Jacinto River Basin into the basin (or directly into the lake) on the residence time of water in Lake Houston. During the time of increased inflow for the two scenarios tested, maximum residence time decreased slightly from approximately 106 to 97 days.
Li, Junxia; Wang, Yanxin; Xie, Xianjun
2016-02-15
In order to identify the salinization processes and its impact on arsenic, fluoride and iodine enrichment in groundwater, hydrogeochemical and environmental isotope studies have been conducted on groundwater from the Datong basin, China. The total dissolved solid (TDS) concentrations in groundwater ranged from 451 to 8250 mg/L, and 41% of all samples were identified as moderately saline groundwater with TDS of 3000-10,000 mg/L. The results of groundwater Cl concentrations, Cl/Br molar ratio and Cl isotope composition suggest that three processes including water-rock interaction, surface saline soil flushing, and evapotranspiration result in the groundwater salinization in the study area. The relatively higher Cl/Br molar ratio in groundwater from multiple screening wells indicates the contribution of halite dissolution from saline soil flushed by vertical infiltration to the groundwater salinization. However, the results of groundwater Cl/Br molar ratio model indicate that the effect of saline soil flushing practice is limited to account for the observed salinity variation in groundwater. The plots of groundwater Cl vs. Cl/Br molar ratio, and Cl vs δ(37)Cl perform the dominant effects of evapotranspiration on groundwater salinization. Inverse geochemical modeling results show that evapotranspiration may cause approximately 66% loss of shallow groundwater to account for the observed hydrochemical pattern. Due to the redox condition fluctuation induced by irrigation activities and evapotranspiration, groundwater salinization processes have negative effects on groundwater arsenic enrichment. For groundwater iodine and fluoride enrichment, evapotranspiration partly accounts for their elevation in slightly saline water. However, too strong evapotranspiration would restrict groundwater fluoride concentration due to the limitation of fluorite solubility. Copyright © 2015. Published by Elsevier B.V.
Luo, Jun-Yu; Zhang, Shuai; Peng, Jun; Zhu, Xiang-Zhen; Lv, Li-Min; Wang, Chun-Yi; Li, Chun-Hua; Zhou, Zhi-Guo; Cui, Jin-Jie
2017-01-01
An increasing area of transgenic Bacillus thuringiensis (Bt) cotton is being planted in saline-alkaline soil in China. The Bt protein level in transgenic cotton plants and its control efficiency can be affected by abiotic stress, including high temperature, water deficiency and other factors. However, how soil salinity affects the expression of Bt protein, thus influencing the control efficiency of Bt cotton against the cotton bollworm (CBW) Helicoverpa armigera (Hübner) in the field, is poorly understood. Our objective in the present study was to investigate the effects of soil salinity on the expression of Bt toxin (Cry1Ac) and the control efficiency of Helicoverpa armigera in field-grown transgenic Bt cotton using three natural saline levels (1.15 dS m-1 [low soil-salinity], 6.00 dS m-1 [medium soil-salinity] and 11.46 dS m-1 [high soil-salinity]). We found that the Bt protein content in the transgenic Bt cotton leaves and the insecticidal activity of Bt cotton against CBW decreased with the increasing soil salinity in laboratory experiments during the growing season. The Bt protein content of Bt cotton leaves in the laboratory were negatively correlated with the salinity level. The CBW populations were highest on the Bt cotton grown in medium-salinity soil instead of the high-salinity soil in field conditions. A possible mechanism may be that the relatively high-salinity soil changed the plant nutritional quality or other plant defensive traits. The results from this study may help to identify more appropriate practices to control CBW in Bt cotton fields with different soil salinity levels.
Luo, Jun-Yu; Zhang, Shuai; Peng, Jun; Zhu, Xiang-Zhen; Lv, Li-Min; Wang, Chun-Yi; Li, Chun-Hua; Zhou, Zhi-Guo; Cui, Jin-Jie
2017-01-01
An increasing area of transgenic Bacillus thuringiensis (Bt) cotton is being planted in saline-alkaline soil in China. The Bt protein level in transgenic cotton plants and its control efficiency can be affected by abiotic stress, including high temperature, water deficiency and other factors. However, how soil salinity affects the expression of Bt protein, thus influencing the control efficiency of Bt cotton against the cotton bollworm (CBW) Helicoverpa armigera (Hübner) in the field, is poorly understood. Our objective in the present study was to investigate the effects of soil salinity on the expression of Bt toxin (Cry1Ac) and the control efficiency of Helicoverpa armigera in field-grown transgenic Bt cotton using three natural saline levels (1.15 dS m-1 [low soil-salinity], 6.00 dS m-1 [medium soil-salinity] and 11.46 dS m-1 [high soil-salinity]). We found that the Bt protein content in the transgenic Bt cotton leaves and the insecticidal activity of Bt cotton against CBW decreased with the increasing soil salinity in laboratory experiments during the growing season. The Bt protein content of Bt cotton leaves in the laboratory were negatively correlated with the salinity level. The CBW populations were highest on the Bt cotton grown in medium-salinity soil instead of the high-salinity soil in field conditions. A possible mechanism may be that the relatively high-salinity soil changed the plant nutritional quality or other plant defensive traits. The results from this study may help to identify more appropriate practices to control CBW in Bt cotton fields with different soil salinity levels. PMID:28099508
Lee, Carol Eunmi; Moss, Wynne E; Olson, Nora; Chau, Kevin Fongching; Chang, Yu-Mei; Johnson, Kelsey E
2013-01-01
Saline to freshwater invasions have become increasingly common in recent years. A key hypothesis is that rates of freshwater invasions have been amplified in recent years by increased food concentration, yet this hypothesis has remained unexplored. We examined whether elevated food concentration could enhance freshwater tolerance, and whether this effect evolves following saline to freshwater invasions. We examined physiological response to salinity and food concentration in a 2 × 2 factorial design, using ancestral brackish and freshwater invading populations of the copepod Eurytemora affinis. We found that high food concentration significantly increases low-salinity tolerance. This effect was reduced in the freshwater population, indicating evolution following the freshwater invasion. Thus, ample food could enable freshwater invasions, allowing subsequent evolution of low-salinity tolerance even under food-poor conditions. We also compared effects of food concentration on freshwater survival between two brackish populations from the native range. Impacts of food concentration on freshwater survival differed between the brackish populations, suggesting variation in functional properties affecting their propensity to invade freshwater habitats. The key implication is that high food concentration could profoundly extend range expansions of brackishwater species into freshwater habitats, potentially allowing for condition-specific competition between saline invaders and resident freshwater species. PMID:23789033
Bioaccumulation of perfluorochemicals in Pacific oyster under different salinity gradients.
Jeon, Junho; Kannan, Kurunthachalam; Lim, Han Kyu; Moon, Hyo Bang; Ra, Jin Sung; Kim, Sang Don
2010-04-01
Despite the reports of widespread occurrence of perfluorinated compounds (PFCs) in estuarine and coastal waters and open seas, little is known on the effect of salinity on bioaccumulation. In this study, effects of salinity on bioaccumulation of PFCs in Pacific oysters (Crassostrea gigas) were investigated. Furthermore, partitioning of PFCs between water and particles (oysters' food) was examined at different salinities. The distribution coefficients (K(d); partitioning between water and particles) for selected PFCs, that is, PFOS, PFOA, PFDA, and PFUnDA, increased by 2.1- to 2.7-fold with the increase in water salinity from 10 to 34 psu, suggesting "salting-out" effect, and the salting constant (delta) was estimated to range from 0.80 to 1.11. The nonlinear regression analysis of bioaccumulation suggested increase in aqueous and dietary uptake rates (K(w) and K(f)), with the increase in salinity, which resulted in elevated bioaccumulation, although the depuration rates (K(e)) also increased. The relative abundance of long carbon chain length PFCs (i.e., PFDA and PFUnDA) increased as salinity increased, while the proportion of PFOS and PFOA decreased, which is explained by the positive relationship between delta and carbon chain length. The contribution of diet to bioaccumulation in oysters ranged from 18 to 92%. Overall, salinity not only affected the chemistry of PFCs, but also the physiology of oysters, contributing to sorption and bioaccumulation of perfluorochemicals in oysters.
The role of salinity in the trophic transfer of 137Cs in euryhaline fish.
Pouil, Simon; Oberhänsli, François; Swarzenski, Peter W; Bustamante, Paco; Metian, Marc
2018-09-01
In order to better understand the influence of changing salinity conditions on the trophic transfer of 137 Cs in marine fish that live in dynamic coastal environments, its depuration kinetics was investigated in controlled aquaria. The juvenile turbot Scophthalmus maximus was acclimated to three distinct salinity conditions (10, 25 and 38) and then single-fed with compounded pellets that were radiolabelled with 137 Cs. At the end of a 21-d depuration period, assimilation efficiencies (i.e. AEs = proportion of 137 Cs ingested that is actually assimilated by turbots) were determined from observational data acquired over the three weeks. Our results showed that AEs of 137 Cs in the turbots acclimated to the highest salinity condition were significantly lower than for the other conditions (p < 0.05). Osmoregulation likely explains the decreasing AE observed at the highest salinity condition. Indeed, observations indicate that fish depurate ingested 137 Cs at a higher rate when they increase ion excretion, needed to counterbalance the elevated salinity. Such data confirm that ambient salinity plays an important role in trophic transfer of 137 Cs in some fish species. Implications for such findings extend to seafood safety and climate change impact studies, where the salinity of coastal waters may shift in future years in response to changing weather patterns. Copyright © 2018 Elsevier Ltd. All rights reserved.
Chen, Lei; Mao, Feijian; Kirumba, George Chira; Jiang, Cheng; Manefield, Mike; He, Yiliang
2015-12-01
Microcystis (M.) aeruginosa, one of the most common bloom-forming cyanobacteria, occurs worldwide. The Qingcaosha (QCS) Reservoir is undergoing eutrophication and faces the problem of saltwater intrusion. The aim of this study was to investigate the effects of sudden salinity changes on physiological parameters and related gene transcription in M. aeruginosa under controlled laboratory conditions. The results showed that sodium chloride (50, 200 and 500 mg L(-1) NaCl) inhibited the algal growth and decreased pigment concentrations (chlorophyll a, carotenoid and phycocyanin). Sodium chloride increased both the intracellular and extracellular microcystin contents and elevated the mcyD transcript level in M. aeruginosa. It also increased the malondialdehyde (MDA) content and caused cytomembrane damage. This damage caused the release of intracellular toxins into the culture medium. In addition, NaCl decreased the maximum electron transport rate, increased the levels of reactive oxygen species (ROS) and changed the cellular redox status. Consequently, NaCl inhibited the expression of cpcB, psbA and rbcL. Furthermore, NaCl increased the activities of superoxide dismutases (SOD), catalase (CAT), glutathione reductase (GR), and total glutathione peroxidase (GPx). The transcript levels of sod and reduced glutathione (gsh) were also increased after exposure to NaCl. Our results indicate that a sudden increase in salinity increases the production and excretion of microcystin, changes the cellular redox status, enhances the activities of antioxidant enzymes, inhibits photosynthesis, and affects transcript levels of related genes in M. aeruginosa. Copyright © 2015 Elsevier Inc. All rights reserved.
Drinking cholera: salinity levels and palatability of drinking water in coastal Bangladesh.
Grant, Stephen Lawrence; Tamason, Charlotte Crim; Hoque, Bilqis Amin; Jensen, Peter Kjaer Mackie
2015-04-01
To measure the salinity levels of common water sources in coastal Bangladesh and explore perceptions of water palatability among the local population to investigate the plausibility of linking cholera outbreaks in Bangladesh with ingestion of saline-rich cholera-infected river water. Hundred participants took part in a taste-testing experiment of water with varying levels of salinity. Salinity measurements were taken of both drinking and non-drinking water sources. Informal group discussions were conducted to gain an in-depth understanding of water sources and water uses. Salinity levels of non-drinking water sources suggest that the conditions for Vibrio cholerae survival exist 7-8 days within the local aquatic environment. However, 96% of participants in the taste-testing experiment reported that they would never drink water with salinity levels that would be conducive to V. cholerae survival. Furthermore, salinity levels of participant's drinking water sources were all well below the levels required for optimal survival of V. cholerae. Respondents explained that they preferred less salty and more aesthetically pleasing drinking water. Theoretically, V. cholerae can survive in the river systems in Bangladesh; however, water sources which have been contaminated with river water are avoided as potential drinking water sources. Furthermore, there are no physical connecting points between the river system and drinking water sources among the study population, indicating that the primary driver for cholera cases in Bangladesh is likely not through the contamination of saline-rich river water into drinking water sources. © 2015 John Wiley & Sons Ltd.
NASA Astrophysics Data System (ADS)
Saruwatari, K.; Satoh, M.; Harada, N.; Suzuki, I.; Shiraiwa, Y.
2015-11-01
Strains of the coccolithophore Emiliania huxleyi (Haptophyta) collected from the subarctic North Pacific and Arctic Oceans during the R/V MIRAI cruise in 2010 (MR10-05) were established as clone cultures and have been maintained in the laboratory at 15 °C and 32 ‰ salinity. To study the physiological responses of coccolith formation to changes in temperature and salinity, growth experiments and morphometric investigations were performed on two strains of MR57N isolated from the northern Bering Sea (56°58' N, 167°11' W) and MR70N at the Chukchi Sea (69°99' N, 168° W). This is the first report of a detailed morphometric and morphological investigation of Arctic Ocean coccolithophore strains. The specific growth rates at the logarithmic growth phases in both strains markedly increased as temperature was elevated from 5 to 20 °C, although coccolith productivity (the percentage of calcified cells) was similar at 10-20 % at all temperatures. On the other hand, the specific growth rate of strain MR70N was affected less by changes in salinity in the range 26-35 ‰, but the proportion of calcified cells decreased at high and low salinities. According to scanning electron microscopy (SEM) observations, coccolith morphotypes can be categorized into Type B/C on the basis of their biometrical parameters, such as length of the distal shield (LDS), length of the inner central area (LICA), and the thickness of distal shield elements. The central area elements of coccoliths varied from grilled type to closed type when temperature was increased or salinity was decreased, and coccolith size decreased simultaneously. Coccolithophore cell size also decreased with increasing temperature, although the variation in cell size was slightly greater at the lower salinity level. This indicates that subarctic and arctic coccolithophore strains can survive in a wide range of seawater temperatures and at lower salinities due to their marked morphometric adaptation ability. Because all coccolith biometric parameters followed the scaling law, the decrease in coccolith size was caused simply by the reduced calcification. Taken together, our results suggest that calcification productivity may be used to predict future oceanic environmental conditions in the Polar Regions.
Erlinge, David; Götberg, Matthias; Lang, Irene; Holzer, Michael; Noc, Marko; Clemmensen, Peter; Jensen, Ulf; Metzler, Bernhard; James, Stefan; Bötker, Hans Erik; Omerovic, Elmir; Engblom, Henrik; Carlsson, Marcus; Arheden, Håkan; Ostlund, Ollie; Wallentin, Lars; Harnek, Jan; Olivecrona, Göran K
2014-05-13
The aim of this study was to confirm the cardioprotective effects of hypothermia using a combination of cold saline and endovascular cooling. Hypothermia has been reported to reduce infarct size (IS) in patients with ST-segment elevation myocardial infarctions. In a multicenter study, 120 patients with ST-segment elevation myocardial infarctions (<6 h) scheduled to undergo percutaneous coronary intervention were randomized to hypothermia induced by the rapid infusion of 600 to 2,000 ml cold saline and endovascular cooling or standard of care. Hypothermia was initiated before percutaneous coronary intervention and continued for 1 h after reperfusion. The primary end point was IS as a percent of myocardium at risk (MaR), assessed by cardiac magnetic resonance imaging at 4 ± 2 days. Mean times from symptom onset to randomization were 129 ± 56 min in patients receiving hypothermia and 132 ± 64 min in controls. Patients randomized to hypothermia achieved a core body temperature of 34.7°C before reperfusion, with a 9-min longer door-to-balloon time. Median IS/MaR was not significantly reduced (hypothermia: 40.5% [interquartile range: 29.3% to 57.8%; control: 46.6% [interquartile range: 37.8% to 63.4%]; relative reduction 13%; p = 0.15). The incidence of heart failure was lower with hypothermia at 45 ± 15 days (3% vs. 14%, p < 0.05), with no mortality. Exploratory analysis of early anterior infarctions (0 to 4 h) found a reduction in IS/MaR of 33% (p < 0.05) and an absolute reduction of IS/left ventricular volume of 6.2% (p = 0.15). Hypothermia induced by cold saline and endovascular cooling was feasible and safe, and it rapidly reduced core temperature with minor reperfusion delay. The primary end point of IS/MaR was not significantly reduced. Lower incidence of heart failure and a possible effect in patients with early anterior ST-segment elevation myocardial infarctions need confirmation. (Efficacy of Endovascular Catheter Cooling Combined With Cold Saline for the Treatment of Acute Myocardial Infarction [CHILL-MI]; NCT01379261). Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.
Garris, D R
1984-05-01
The role of uterine blood flow (UBF) in the modulation of experimentally induced decidua formation was assessed in mature guinea pigs. The response to endometrial trauma, as indexed by uterine weight changes, was dependent upon the type of stimulus used, with deciduogenic effectiveness as follows: saline = oil = knife scratch less than scissor cut. Both the knife scratch and scissor cut techniques induced elevations in UBF compared with control values. Neither uterine weight nor UBF increased when trauma was applied to unresponsive uteri, indicating that inflammation was not the cause of uterine hyperemia. Uterine weight increased from basal levels on the day of trauma (i.e. day 5 of the estrous cycle) to a maximal weight between days 10 and 12 posttrauma. Maximal growth of the induced decidua occurred under conditions of elevated UBF. Subsequently, UBF declined between days 10 and 15 posttrauma, preceding the associate resorption of the induced decidua. During the period of decidua growth, serum progesterone levels were elevated compared with those in control animals. These data indicate that experimentally induced decidua formation in the guinea pig is associated with uterine hyperemia and increased corpus luteum activity, both of which are necessary for proper endometrial differentiation. It is hypothesized that these events mimic the uterine hyperemia associated with blastocyst implanplantation and early placentation in this species.
Breves, Jason P; Hirano, Tetsuya; Grau, E Gordon
2010-03-01
This study assessed the endocrine and ionoregulatory responses by tilapia (Oreochromis mossambicus) to disturbances of hydromineral balance during confinement and handling. In fresh water (FW), confinement and handling for 0.5, 1, 2 and 6h produced elevations in plasma cortisol and glucose; a reduction in plasma osmolality was observed at 6h. Elevations in plasma prolactins (PRL(177) and PRL(188)) accompanied this fall in osmolality while no effect upon growth hormone (GH) was evident; an increase in insulin-like growth-factor I (IGF-I) occurred at 0.5h. In seawater (SW), confinement and handling increased plasma osmolality and glucose between 0.5 and 6h; no effect on plasma cortisol was seen due to variable control levels. Concurrently, both PRLs were reduced in stressed fish with only transient changes in the GH/IGF-I axis. Next, the branchial expression of Na(+)/K(+)/2Cl(-) cotransporter (NKCC) and Na(+)/Cl(-) cotransporter (NCC) was characterized following confinement and handling for 6h. In SW, NKCC mRNA levels increased in stressed fish concurrently with elevated plasma osmolality and diminished gill Na(+), K(+)-ATPase activity; NCC was unchanged in stressed fish irrespective of salinity. Taken together, PRL and NKCC participate in restoring osmotic balance during acute stress while the GH/IGF-I axis displays only modest responses. Copyright 2009 Elsevier Inc. All rights reserved.
Productivity and food value of Amaranthus cruentus under non-lethal salt stress
NASA Technical Reports Server (NTRS)
Macler, Bruce A.; Macelroy, Robert D.
1989-01-01
Experiments were carried out to analyze the effects of increasing salinity stress on growth, photosynthesis, and carbon allocation in the crop plant Amaranthus. Plants were germinated and grown in Hoagland's solution with NaCl concentrations of 0 to 1.0 percent. The limits of total salinity in the plant growth medium are investigated. For Amaranthus cruentus, germination, vegetative growth, flowering, seed development and yield were normal at salinities from 0 to 0.2 percent. Inhibition of these phases increased from o.2 to 0.4 percent salinity and was total above 0.5 percent with 1 percent salinity was lethal to all developmental phases. Onset of growth phases were not affected by salinity. Plants could not be adapted by gradually increasing salinity over days or weeks. Water uptake increased, while photosynthetic CO2 uptake decreased with increasing salinity on a dry weight basis during vegetative growth. Protein levels were unchanged with increasing salinity. Leaf starch levels were lower at salinities of 0.5 percent and above, while stem starch levels were not affected by these salinities. The evidence supports salt inhibition arising frm changes in primary biochemical processes rather than from effects on water relations. While not addressing the toxic effects of specific ions, it suggests that moderate salinity per se need not be a problem in space systems.
Salinity of the Delaware Estuary
Cohen, Bernard; McCarthy, Leo T.
1962-01-01
The purpose of this investigation was to obtain data on and study the factors affecting the salinity of the Delaware River from Philadelphia, Pa., to the Appoquinimink River, Del. The general chemical quality of water in the estuary is described, including changes in salinity in the river cross section and profile, diurnal and seasonal changes, and the effects of rainfall, sea level, and winds on salinity. Relationships are established of the concentrations of chloride and dissolved solids to specific conductance. In addition to chloride profiles and isochlor plots, time series are plotted for salinity or some quantity representing salinity, fresh-water discharge, mean river level, and mean sea level. The two major variables which appear to have the greatest effect on the salinity of the estuary are the fresh-water flow of the river and sea level. The most favorable combination of these variables for salt-water encroachment occurs from August to early October and the least favorable combination occurs between December and May.
Levkovitz, Yechiel; Fenchel, Daphna; Kaplan, Zeev; Zohar, Joseph; Cohen, Hagit
2015-01-01
We assessed the effects of minocycline, a tetracycline with anti-inflammatory, anti-apoptotic and neuroprotective capacities, in an animal model of post-traumatic stress disorder (PTSD). Rats were exposed to psychogenic stress and treated 1h later with minocycline or saline. Behavioral measures included the elevated plus-maze (EPM) and acoustic startle response (ASR) 7 days post stress-exposure. One day after behavioral testing, animals were exposed to a trauma cue and freezing response was assessed. Local levels of cytokines interleukin-1 (IL-1), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) in the hippocampus, frontal cortex (FC) and hypothalamus were then examined. Minocycline attenuated anxious-like behaviors in stress-exposed rats. In addition, decreased levels of cytokines were measured in exposed rats treated with minocycline compared to their counterparts treated with saline. This study suggests a potential use of minocycline in preventing physiological and behavioral alternations resulting from acute exposure to psychological stress. As this is the first study to report beneficial outcomes for minocycline treatment in an animal model of PTSD, further investigations of the use of minocycline in stress-related conditions with emphasis on PTSD is needed. Copyright © 2014 Elsevier B.V. and ECNP. All rights reserved.
Different cucumber CsYUC genes regulate response to abiotic stresses and flower development.
Yan, Shuangshuang; Che, Gen; Ding, Lian; Chen, Zijing; Liu, Xiaofeng; Wang, Hongyin; Zhao, Wensheng; Ning, Kang; Zhao, Jianyu; Tesfamichael, Kiflom; Wang, Qian; Zhang, Xiaolan
2016-02-09
The phytohormone auxin is essential for plant growth and development, and YUCCA (YUC) proteins catalyze a rate-limiting step for endogenous auxin biosynthesis. Despite YUC family genes have been isolated from several species, systematic expression analyses of YUCs in response to abiotic stress are lacking, and little is known about the function of YUC homologs in agricultural crops. Cucumber (Cucumis sativus L.) is a world cultivated vegetable crop with great economical and nutritional value. In this study, we isolated 10 YUC family genes (CsYUCs) from cucumber and explored their expression pattern under four types of stress treatments. Our data showed that CsYUC8 and CsYUC9 were specifically upregulated to elevate the auxin level under high temperature. CsYUC10b was dramatically increased but CsYUC4 was repressed in response to low temperature. CsYUC10a and CsYUC11 act against the upregulation of CsYUC10b under salinity stress, suggesting that distinct YUC members participate in different stress response, and may even antagonize each other to maintain the proper auxin levels in cucumber. Further, CsYUC11 was specifically expressed in the male flower in cucumber, and enhanced tolerance to salinity stress and regulated pedicel and stamen development through auxin biosynthesis in Arabidopsis.
Shrestha, Namita; Chilkoor, Govinda; Wilder, Joseph; Gadhamshetty, Venkataramana; Stone, James J
2017-01-01
Modern drilling techniques, notably horizontal drilling and hydraulic fracturing, have enabled unconventional oil production (UOP) from the previously inaccessible Bakken Shale Formation located throughout Montana, North Dakota (ND) and the Canadian province of Saskatchewan. The majority of UOP from the Bakken shale occurs in ND, strengthening its oil industry and businesses, job market, and its gross domestic product. However, similar to UOP from other low-permeability shales, UOP from the Bakken shale can result in environmental and human health effects. For example, UOP from the ND Bakken shale generates a voluminous amount of saline wastewater including produced and flowback water that are characterized by unusual levels of total dissolved solids (350 g/L) and elevated levels of toxic and radioactive substances. Currently, 95% of the saline wastewater is piped or trucked onsite prior to disposal into Class II injection wells. Oil and gas wastewater (OGW) spills that occur during transport to injection sites can potentially result in drinking water resource contamination. This study presents a critical review of potential water resource impacts due to deterministic (freshwater withdrawals and produced water management) and probabilistic events (spills due to leaking pipelines and truck accidents) related to UOP from the Bakken shale in ND. Copyright © 2016 Elsevier Ltd. All rights reserved.
2013-01-01
Background Prolactin (PRL) is a key hormone for osmoregulation in fish. Levels of PRL in the pituitary gland and plasma ion composition of clownfish seem to change to regulate their hydromineral balance during adaptation to waters of different salinities. In order to understand osmoregulatory mechanism and its association with growth performance and PRL in fish, the gene encoding PRL and its expression level in cinnamon clownfish Amphiprion melanopus upon acclimation to low salinity was analyzed. Results The PRL gene of A. melanopus encoded a protein of 212 amino acid residues comprised of a putative signal peptide of 24 amino acids and a mature protein of 188 amino acids. Analysis of growth performance under different salinities of 34, 25, 15, and 10 ppt indicated that cinnamon clownfish could survive under salinities as low as 10 ppt. A higher rate of growth was observed at the lower salinities as compared to that of 34 ppt. Upon shifting the salinity of the surrounding water from 34 ppt to 15 ppt, the level of the PRL transcripts gradually increased to reach the peak level until 24 h of acclimation at 15 ppt, but decreased back as adaptation continued to 144 h. In contrast, levels of plasma Na+, Cl-, and osmolality decreased at the initial stage (4–8 h) of acclimation at 15 pt but increased back as adaptation continued till 144 h. Conclusion Cinnamon clownfish could survive under salinities as low as 10 ppt. Upon shifting the salinity of the surrounding water from 34 ppt to 15 ppt, the level of the PRL transcripts gradually increased during the initial stage of acclimation but decreased back to the normal level as adaptation continued. An opposite pattern of changes - decrease at the beginning followed by an increase - in the levels of plasma Na+, Cl-, and osmolality was found upon acclimation to low salinity. The results suggest an involvement of PRL in the processes of osmoregulation and homeostasis in A. melanopus. PMID:23276106
Noh, Gyeong Eon; Rho, Sum; Chang, Yong Jin; Min, Byung Hwa; Kim, Jong-Myoung
2013-01-01
Prolactin (PRL) is a key hormone for osmoregulation in fish. Levels of PRL in the pituitary gland and plasma ion composition of clownfish seem to change to regulate their hydromineral balance during adaptation to waters of different salinities. In order to understand osmoregulatory mechanism and its association with growth performance and PRL in fish, the gene encoding PRL and its expression level in cinnamon clownfish Amphiprion melanopus upon acclimation to low salinity was analyzed. The PRL gene of A. melanopus encoded a protein of 212 amino acid residues comprised of a putative signal peptide of 24 amino acids and a mature protein of 188 amino acids. Analysis of growth performance under different salinities of 34, 25, 15, and 10 ppt indicated that cinnamon clownfish could survive under salinities as low as 10 ppt. A higher rate of growth was observed at the lower salinities as compared to that of 34 ppt. Upon shifting the salinity of the surrounding water from 34 ppt to 15 ppt, the level of the PRL transcripts gradually increased to reach the peak level until 24 h of acclimation at 15 ppt, but decreased back as adaptation continued to 144 h. In contrast, levels of plasma Na+, Cl-, and osmolality decreased at the initial stage (4-8 h) of acclimation at 15 pt but increased back as adaptation continued till 144 h. Cinnamon clownfish could survive under salinities as low as 10 ppt. Upon shifting the salinity of the surrounding water from 34 ppt to 15 ppt, the level of the PRL transcripts gradually increased during the initial stage of acclimation but decreased back to the normal level as adaptation continued. An opposite pattern of changes - decrease at the beginning followed by an increase - in the levels of plasma Na+, Cl-, and osmolality was found upon acclimation to low salinity. The results suggest an involvement of PRL in the processes of osmoregulation and homeostasis in A. melanopus.
Jillette, Nathaniel; Cammack, Lauren; Lowenstein, Margaret; Henry, Raymond P
2011-02-01
The euryhaline green crab, Carcinus maenas, undergoes an annual cycle of salinity exposure, having to adapt to low salinity during its annual spring migration into estuaries, and then having to re-adapt to high salinity when it moves off-shore at the end of summer. Most studies have focused on low salinity acclimation, the activation of osmoregulatory mechanisms, and the induction of transport protein and transport-related enzyme activity and gene expression. In this study we followed the changes in hemolymph osmolality, carbonic anhydrase activity, and mRNA expression of three proteins through a complete cycle of low (15 ppt) and high (32 ppt) salinity acclimation. One week of low salinity acclimation resulted in hemolymph osmoregulation and a four-fold induction of branchial carbonic anhydrase activity. Relative mRNA expression increased for two CA isoforms (CAc 100-fold, and CAg 7-fold) and the α-subunit of the Na/K-ATPase (8-fold). Upon re-exposure to high salinity, hemolymph osmolality increased to 32 ppt acclimated levels by 6 h, and mRNA levels returned to high salinity, baseline levels within 1 week. However, CA activity remained unchanged in response to high salinity exposure for the first week and then gradually declined to baseline levels over 4 weeks. The relative timing of these changes suggests that while whole-organism physiological adaptations and regulation at the gene level can be very rapid, changes at the level of protein expression and turnover are much slower. It is possible that the high metabolic cost of protein synthesis and/or processing could be the underlying reason for long biological life spans of physiologically important proteins. Published by Elsevier Inc.
Goode, Daniel J.; Senior, Lisa A.; Subah, Ali; Jaber, Ayman
2013-01-01
Changes in groundwater levels and salinity in six groundwater basins in Jordan were characterized by using linear trends fit to well-monitoring data collected from 1960 to early 2011. On the basis of data for 117 wells, groundwater levels in the six basins were declining, on average about -1 meter per year (m/yr), in 2010. The highest average rate of decline, -1.9 m/yr, occurred in the Jordan Side Valleys basin, and on average no decline occurred in the Hammad basin. The highest rate of decline for an individual well was -9 m/yr. Aquifer saturated thickness, a measure of water storage, was forecast for year 2030 by using linear extrapolation of the groundwater-level trend in 2010. From 30 to 40 percent of the saturated thickness, on average, was forecast to be depleted by 2030. Five percent of the wells evaluated were forecast to have zero saturated thickness by 2030. Electrical conductivity was used as a surrogate for salinity (total dissolved solids). Salinity trends in groundwater were much more variable and less linear than groundwater-level trends. The long-term linear salinity trend at most of the 205 wells evaluated was not increasing, although salinity trends are increasing in some areas. The salinity in about 58 percent of the wells in the Amman-Zarqa basin was substantially increasing, and the salinity in Hammad basin showed a long-term increasing trend. Salinity increases were not always observed in areas with groundwater-level declines. The highest rates of salinity increase were observed in regional discharge areas near groundwater pumping centers.
Is there a signal of sea-level rise in Chesapeake Bay salinity?
NASA Astrophysics Data System (ADS)
Hilton, T. W.; Najjar, R. G.; Zhong, L.; Li, M.
2008-09-01
We evaluate the hypothesis that sea-level rise over the second half of the 20th century has led to detectable increases in Chesapeake Bay salinity. We exploit a simple, statistical model that predicts monthly mean salinity as a function of Susquehanna River flow in 23 segments of the main stem Chesapeake Bay. The residual (observed minus modeled) salinity exhibits statistically significant linear (p < 0.05) trends between 1949 and 2006 in 13 of the 23 segments of the bay. The salinity change estimated from the trend line over this period varies from -2.0 to 2.2, with 10 of the 13 cells showing positive changes. The mean and median salinity changes over all 23 cells are 0.47 and 0.72; over the 13 cells with significant trends they are 0.71 and 1.1. We ran a hydrodynamic model of the bay under present-day and reduced sea level conditions and found a bay-average salinity increase of about 0.5, which supports the hypothesis that the salinity residual trends have a significant component due to sea-level rise. Uncertainties remain, however, due to the spatial and temporal extent of historical salinity data and the infilling of the bay due to sedimentation. The salinity residuals also exhibit interannual variability, with peaks occurring at intervals of roughly 7 to 9 years, which are partially explained by Atlantic Shelf salinity, Potomac River flow and the meridional component of wind stress.
Duration of rise in free fatty acids determines salicylate's effect on hepatic insulin sensitivity
Pereira, Sandra; Yu, Wen Qin; Frigolet, María E; Beaudry, Jacqueline L; Shpilberg, Yaniv; Park, Edward; Dirlea, Cristina; Nyomba, B L Grégoire; Riddell, Michael C; Fantus, I George; Giacca, Adria
2013-01-01
We have shown in rats that sodium salicylate (SS), which inhibits IkBa kinase B (IKKB), prevents hepatic and peripheral insulin resistance caused by short-term (7 h) i.v. administration of Intralipid and heparin (IH). We wished to further determine whether this beneficial effect of SS persisted after prolonged (48 h) IH infusion, which better mimics the chronic free fatty acid (FFA) elevation of obesity. Hence, we performed hyperinsulinemic euglycemic clamps with tritiated glucose methodology to determine hepatic and peripheral insulin sensitivity in rats infused with saline, IH, IH and SS, or SS alone. SS prevented peripheral insulin resistance (P<0.05) caused by prolonged plasma FFA elevation; however, it did not prevent hepatic insulin resistance. In skeletal muscle, protein levels of phospho-IkBa were augmented by prolonged IH administration and this was prevented by SS, suggesting that IH activates while SS prevents the activation of IKKB. Markers of IKKB activation, namely protein levels of phospho-IkBa and IkBa, indicated that IKKB is not activated in the liver after prolonged FFA elevation. Phosphorylation of serine 307 at insulin receptor substrate (IRS)-1, which is a marker of proximal insulin resistance, was not altered by IH administration in the liver, suggesting that this is not a site of hepatic insulin resistance in the prolonged lipid infusion model. Our results suggest that the role of IKKB in fat-induced insulin resistance is time and tissue dependent and that hepatic insulin resistance induced by prolonged lipid elevation is not due to an IRS-1 serine 307 kinase. PMID:23328071
Li, Shi-Hua; Ge, Zhen-Ming; Xie, Li-Na; Chen, Wei; Yuan, Lin; Wang, Dong-Qi; Li, Xiu-Zhen; Zhang, Li-Quan
2018-02-05
The ecophysiological characteristics of native Phragmites australis and exotic Spartina alterniflora grown under waterlogging and salinity were investigated to explore their adaptation potential to sea level rise. The seasonal course of phenotypic traits, photosynthetic activity and chlorophyll fluorescence parameters of P. australis did not change remarkably under shallow flooding, whereas these variables were sensitive to increasing salinity. Waterlogging exacerbated the negative effects of salinity on shoot growth and photosynthetic activity of P. australis, and the combined stresses led to an absence of tassel and reproductive organs. By contrast, S. alterniflora performed well under both stresses and showed an obvious adaptation of salt secretion with increasing salinity. Light salinity was the optimal condition for S. alterniflora, and the tassel growth, chlorophyll content and fluorescence characters under moderate stresses did not differ notably. The Na + and Cl - concentrations in leaves of both species increased, and the K + content decreased in response to salinity. Under moderate and high saline levels, the ion concentrations in S. alterniflora were maintained at relatively consistent levels with increased salt secretion. We expect the degradation of P. australis and further colonization of S. alterniflora under prolonged flooding and saltwater intrusion from sea level rise on the coastline of China.
Serum corticosterone response to adrenocorticotropic hormone stimulation in Florida sandhill cranes.
Ludders, J W; Langenberg, J A; Czekala, N M; Erb, H N; McCormick, H
1998-10-01
Florida sandhill cranes (Grus canadensis pratensis) were conditioned to confinement in an enclosure for 7 days, 6 hr a day. On day 8, cranes were catheterized and then confined in an enclosure. Venous blood (2 ml) was collected through the catheter and an attached IV line immediately before (-60 min) and 60 min after (0 min) confinement. Using a randomization table and a restricted cross-over experimental design, cranes were injected intravenously with either saline (control) or adrenocorticotropic hormone (ACTH; cosyntropin, Cortrosyn; 0.25 mg). At 30, 60, 120, 180, 240 and 300 min after injection, blood samples were collected and assayed for corticosterone. The cranes receiving ACTH increased their serum corticosterone concentrations as much as fivefold above baseline concentrations. Serum corticosterone concentrations remained significantly elevated for approximately 60 min after ACTH stimulation. Physical restraint and catheterization caused an increase in serum corticosterone almost comparable to that induced by ACTH stimulation. In cranes injected with saline, serum corticosterone decreased within 1 hr after physical restraint and catheterization, and remained at lower levels throughout the remaining 5 hr of confinement.
Role of atrial natriuretic peptide in systemic responses to acute isotonic volume expansion
NASA Technical Reports Server (NTRS)
Watenpaugh, Donald E.; Yancy, Clyde W.; Buckey, Jay C.; Lane, Lynda D.; Hargens, Alan R.; Blomqvist, C. G.
1992-01-01
A hypothesis is proposed that a temporal relationship exists between increases in cardiac filling pressure and plasma artrial natriuretic peptide (ANP) concentration and also between ANP elevation and vasodilation, fluid movement from plasma to interstitium, and increased urine volume (UV). To test the hypothesis, 30 ml/kg isotonic saline were infused in supine male subjects over 24 min and responses were monitored for 3 h postinfusion. Results show that at end infusion, mean arterial pressure (RAP), heart rate and plasma volume exhibited peak increases of 146, 23, and 27 percent, respectively. Mean plasma ANP and UV peaked (45 and 390 percent, respectively) at 30 min postinfusion. Most cardiovascular variables had returned toward control levels by 1 h postinfusion, and net reabsorption of extravascular fluid ensued. It is concluded that since ANP was not significantly increased until 30 min postinfusion, factors other than ANP initiate responses to intravascular fluid loading. These factors include increased vascular pressures, baroreceptor-mediated vasolidation, and hemodilution of plasma proteins. ANP is suggested to mediate, in part, the renal response to saline infusion.
Drought Increases Consumer Pressure on Oyster Reefs in Florida, USA
Garland, Hanna G.; Kimbro, David L.
2015-01-01
Coastal economies and ecosystems have historically depended on oyster reefs, but this habitat has declined globally by 85% because of anthropogenic activities. In a Florida estuary, we investigated the cause of newly reported losses of oysters. We found that the oyster reefs have deteriorated from north to south and that this deterioration was positively correlated with the abundance of carnivorous conchs and water salinity. In experiments across these gradients, oysters survived regardless of salinity if conchs were excluded. After determining that conchs were the proximal cause of oyster loss, we tested whether elevated water salinity was linked to conch abundance either by increasing conch growth and survivorship or by decreasing the abundance of a predator of conchs. In field experiments across a salinity gradient, we failed to detect spatial variation in predation on conchs or in conch growth and survivorship. A laboratory experiment, however, demonstrated the role of salinity by showing that conch larvae failed to survive at low salinities. Because this estuary’s salinity increased in 2006 in response to reduced inputs of freshwater, we concluded that the ultimate cause of oyster decline was an increase in salinity. According to records from 2002 to 2012, oyster harvests have remained steady in the northernmost estuaries of this ecoregion (characterized by high reef biomass, low salinity, and low conch abundance) but have declined in the southernmost estuaries (characterized by lower reef biomass, increases in salinity, and increases in conch abundance). Oyster conservation in this ecoregion, which is probably one of the few that still support viable oyster populations, may be undermined by drought-induced increases in salinity causing an increased abundance of carnivorous conchs. PMID:26275296
Kokare, Dadasaheb M; Kyzar, Evan J; Zhang, Huaibo; Sakharkar, Amul J; Pandey, Subhash C
2017-09-01
Adolescent intermittent ethanol exposure causes long-lasting alterations in brain epigenetic mechanisms. Melanocortin and neuropeptide Y signaling interact and are affected by ethanol exposure in the brain. Here, the persistent effects of adolescent intermittent ethanol on alpha-melanocyte stimulating hormone, melanocortin 4 receptor, and neuropeptide Y expression and their regulation by histone acetylation mechanisms were investigated in adulthood. Male rats were exposed to adolescent intermittent ethanol (2 g/kg, i.p.) or volume-matched adolescent intermittent saline from postnatal days 28 to 41 and allowed to grow to postnatal day 92. Anxiety-like behaviors were measured by the elevated plus-maze test. Brain regions from adult rats were used to examine changes in alpha-melanocyte stimulating hormone, melanocortin 4 receptor, and neuropeptide Y expression and the histone acetylation status of their promoters. Adolescent intermittent ethanol-exposed adult rats displayed anxiety-like behaviors and showed increased pro-opiomelanocortin mRNA levels in the hypothalamus and increased melanocortin 4 receptor mRNA levels in both the amygdala and hypothalamus compared with adolescent intermittent saline-exposed adult rats. The alpha-Melanocyte stimulating hormone and melanocortin 4 receptor protein levels were increased in the central and medial nucleus of the amygdala, paraventricular nucleus, and arcuate nucleus of the hypothalamus in adolescent intermittent ethanol-exposed compared with adolescent intermittent saline-exposed adult rats. Neuropeptide Y protein levels were decreased in the central and medial nucleus of the amygdala of adolescent intermittent ethanol-exposed compared with adolescent intermittent saline-exposed adult rats. Histone H3K9/14 acetylation was decreased in the neuropeptide Y promoter in the amygdala but increased in the melanocortin 4 receptor gene promoter in the amygdala and the melanocortin 4 receptor and pro-opiomelanocortin promoters in the hypothalamus of adolescent intermittent ethanol-exposed adult rats compared with controls. Increased melanocortin and decreased neuropeptide Y activity due to changes in histone acetylation in emotional brain circuitry may play a role in adolescent intermittent ethanol-induced anxiety phenotypes in adulthood. Published by Oxford University Press on behalf of CINP 2017. This work is written by (a) US Government employee(s) and is in the public domain in the US.
Monitoring Inland Storm Surge and Flooding from Hurricane Rita
McGee, Benton D.; Tollett, Roland W.; Mason, Jr., Robert R.
2006-01-01
Pressure transducers (sensors) and high-water marks were used to document the inland water levels related to storm surge generated by Hurricane Rita in southwestern Louisiana and southeastern Texas. On September 22-23, 2005, an experimental monitoring network of sensors was deployed at 33 sites over an area of about 4,000 square miles to record the timing, extent, and magnitude of inland hurricane storm surge and coastal flooding. Sensors were programmed to record date and time, temperature, and barometric or water pressure. Water pressure was corrected for changes in barometric pressure and salinity. Elevation surveys using global-positioning systems and differential levels were used to relate all storm-surge water-level data, reference marks, benchmarks, sensor measuring points, and high-water marks to the North American Vertical Datum of 1988 (NAVD 88). The resulting data indicated that storm-surge water levels over 14 feet above NAVD 88 occurred at three locations, and rates of water-level rise greater than 5 feet per hour occurred at three locations near the Louisiana coast.
Drollette, Brian D; Hoelzer, Kathrin; Warner, Nathaniel R; Darrah, Thomas H; Karatum, Osman; O'Connor, Megan P; Nelson, Robert K; Fernandez, Loretta A; Reddy, Christopher M; Vengosh, Avner; Jackson, Robert B; Elsner, Martin; Plata, Desiree L
2015-10-27
Hundreds of organic chemicals are used during natural gas extraction via high-volume hydraulic fracturing (HVHF). However, it is unclear whether these chemicals, injected into deep shale horizons, reach shallow groundwater aquifers and affect local water quality, either from those deep HVHF injection sites or from the surface or shallow subsurface. Here, we report detectable levels of organic compounds in shallow groundwater samples from private residential wells overlying the Marcellus Shale in northeastern Pennsylvania. Analyses of purgeable and extractable organic compounds from 64 groundwater samples revealed trace levels of volatile organic compounds, well below the Environmental Protection Agency's maximum contaminant levels, and low levels of both gasoline range (0-8 ppb) and diesel range organic compounds (DRO; 0-157 ppb). A compound-specific analysis revealed the presence of bis(2-ethylhexyl) phthalate, which is a disclosed HVHF additive, that was notably absent in a representative geogenic water sample and field blanks. Pairing these analyses with (i) inorganic chemical fingerprinting of deep saline groundwater, (ii) characteristic noble gas isotopes, and (iii) spatial relationships between active shale gas extraction wells and wells with disclosed environmental health and safety violations, we differentiate between a chemical signature associated with naturally occurring saline groundwater and one associated with alternative anthropogenic routes from the surface (e.g., accidental spills or leaks). The data support a transport mechanism of DRO to groundwater via accidental release of fracturing fluid chemicals derived from the surface rather than subsurface flow of these fluids from the underlying shale formation.
Drollette, Brian D.; Hoelzer, Kathrin; Warner, Nathaniel R.; Darrah, Thomas H.; Karatum, Osman; O’Connor, Megan P.; Nelson, Robert K.; Fernandez, Loretta A.; Reddy, Christopher M.; Vengosh, Avner; Jackson, Robert B.; Elsner, Martin; Plata, Desiree L.
2015-01-01
Hundreds of organic chemicals are used during natural gas extraction via high-volume hydraulic fracturing (HVHF). However, it is unclear whether these chemicals, injected into deep shale horizons, reach shallow groundwater aquifers and affect local water quality, either from those deep HVHF injection sites or from the surface or shallow subsurface. Here, we report detectable levels of organic compounds in shallow groundwater samples from private residential wells overlying the Marcellus Shale in northeastern Pennsylvania. Analyses of purgeable and extractable organic compounds from 64 groundwater samples revealed trace levels of volatile organic compounds, well below the Environmental Protection Agency’s maximum contaminant levels, and low levels of both gasoline range (0–8 ppb) and diesel range organic compounds (DRO; 0–157 ppb). A compound-specific analysis revealed the presence of bis(2-ethylhexyl) phthalate, which is a disclosed HVHF additive, that was notably absent in a representative geogenic water sample and field blanks. Pairing these analyses with (i) inorganic chemical fingerprinting of deep saline groundwater, (ii) characteristic noble gas isotopes, and (iii) spatial relationships between active shale gas extraction wells and wells with disclosed environmental health and safety violations, we differentiate between a chemical signature associated with naturally occurring saline groundwater and one associated with alternative anthropogenic routes from the surface (e.g., accidental spills or leaks). The data support a transport mechanism of DRO to groundwater via accidental release of fracturing fluid chemicals derived from the surface rather than subsurface flow of these fluids from the underlying shale formation. PMID:26460018
Primary Productivity Regime and Nutrient Removal in the Danube Estuary
NASA Astrophysics Data System (ADS)
Humborg, C.
1997-11-01
The primary productivity regime, as well as the distribution of dissolved inorganic nutrients and particulate organic matter in the Danube estuary, were investigated during several cruises at different discharge regimes of the Danube River. The shallowness of the upper surface layer due to insignificant tidal mixing and strong stratification of the Danube estuary, as well as the high nutrient concentrations, are favourable for elevated primary production. The incident light levels at the bottom of the upper surface layer of the water column (0·5-3·0 m) were generally higher than 20% of the surface irradiance. Elevated chlorophyll (Chl) aconcentrations with maxima at mid salinities were found during each survey. Within the upper mixed layer estimated primary production of 0·2-4·4 g m-2day-1is very high compared with estuaries of other major world rivers. Mixing diagrams of dissolved inorganic nutrients reveal removal of significant quantities of nutrients during estuarine mixing. These observations were consistent with the distribution of particular organic matter, which was negatively correlated to the nutrient distribution during each survey. C:Chl aratios, as well as the elevated estimated production, indicate that biological transformation processes govern the nutrient distribution in this estuary.
Strong tidal modulation of net ecosystem exchange in a salt marsh in North Inlet, South Carolina
NASA Astrophysics Data System (ADS)
O'Halloran, T. L.; Smith, E. M.; Bogoev, I.
2017-12-01
Along the southeastern US, intertidal salt marshes represent a critical habitat at the interface of the terrestrial and marine environments and perform a variety of ecological functions and services that make them of great economic importance for coastal communities They provide essential fish and shellfish habitat, with a majority of all commercially- and recreationally important fish species being dependent on intertidal marsh habitat during some portion of their life cycle. The penaeid shrimp industry, South Carolina's most economically important fishery, would cease to exist without the critical nursery function provided by intertidal salt marshes. Smooth cordgrass (Spartina alterniflora) is a keystone species in the high salinity marshes of the southeastern U.S., and its functioning is essential to the health and survival of salt marshes under rising sea levels. To better quantify and facilitate prediction of future salt marsh productivity, in May of 2017, we established a new integrated eddy covariance tower system to measure the net ecosystem exchange of carbon in a salt marsh in coastal South Carolina. The tower site is co-located with long-term, ongoing measurements as part of the North Inlet-Winyah Bay National Estuarine Research Reserve (NI-WB NERR). Current sampling conducted within the eddy flux footprint includes: annual measures of the vegetation community at the time of peak biomass; bi-monthly measures of sediment elevation at Sediment Elevation Tables (SETs) located at the upper and lower ends of the flux footprint; monthly sediment porewater salinity and nutrient (ammonium, orthophosphate) and sulfide concentrations; and biannual sediment elevation surveys by RTK-GPS. A suite of water quality measurements are made every 15 minutes in the main creek that floods the marsh platform in the flux footprint. Here we present our first six months of observations investigating the abiotic drivers of productivity on daily (intratidal) to monthly timescales as determined by the eddy covariance fluxes. Comparisons with other tidal marsh eddy flux observations across the eastern U.S. are presented for context. Initial results suggest our measured net ecosystem exchange may contain the strongest tidal signal reported to date, which could result from the relatively low elevation of our site.
Distribution of trace metals in anchialine caves of Adriatic Sea, Croatia
NASA Astrophysics Data System (ADS)
Cuculić, Vlado; Cukrov, Neven; Kwokal, Željko; Mlakar, Marina
2011-11-01
This study presents results of the first comprehensive research on ecotoxic trace metals (Cd, Pb, Cu and Zn) in aquatic anchialine ecosystems. Data show the influence of hydrological and geological characteristics on trace metals in highly stratified anchialine water columns. Distribution of Cd, Pb, Cu and Zn in two anchialine water bodies, Bjejajka Cave and Lenga Pit in the Mljet National park, Croatia were investigated seasonally from 2006 to 2010. Behaviour and concentrations of dissolved and total trace metals in stratified water columns and metal contents in sediment, carbonate rocks and soil of the anchialine environment were evaluated. Trace metals and dissolved organic carbon (DOC) concentrations in both anchialine water columns were significantly elevated compared to adjacent seawater. Zn and Cu concentrations were the highest in the Lenga Pit water column and sediment. Elevated concentrations of Zn, Pb and Cu in Bjejajka Cave were mainly terrigenous. Significantly elevated concentrations of cadmium (up to 0.3 μg L -1) were found in the water column of Bjejajka cave, almost two orders of magnitude higher compared to nearby surface seawater. Laboratory analysis revealed that bat guano was the major source of cadmium in Bjejajka Cave. Cadmium levels in Lenga Pit, which lacks accumulations of bat guano, were 20-fold lower. Moreover, low metal amounts in carbonate rocks in both caves, combined with mineral leaching experiments, revealed that carbonates play a minor role as a source of metals in both water columns. We observed two types of vertical distribution pattern of cadmium in the stratified anchialine Bjejajka Cave water column. At lower salinities, non-conservative behaviour was characterized by strong desorption and enrichment of dissolved phase while, at salinities above 20, Cd behaved conservatively and its dissolved concentration decreased. Conservative behaviour of Cu, Pb, Zn and DOC was observed throughout the water column. After heavy rains, Cd showed reduced concentration and uniform vertical distribution, suggesting a non-terrestrial origin. Under the same conditions, concentrations of total and dissolved Pb, Cu, Zn and DOC were significantly elevated. Variations of trace metal vertical distributions in anchialine water columns were caused by large inputs of fresh water (extraordinary rainy events), and were not influenced by seasonal changes.
Gwag, Hye Bin; Kim, Eun Kyoung; Park, Taek Kyu; Lee, Joo Myung; Yang, Jeong Hoon; Song, Young Bin; Choi, Jin-Ho; Choi, Seung-Hyuk; Lee, Sang Hoon; Chang, Sung-A; Park, Sung-Ji; Lee, Sang-Chol; Park, Seung Woo; Jang, Woo Jin; Lee, Mirae; Chun, Woo Jung; Oh, Ju Hyeon; Park, Yong Hwan; Choe, Yeon Hyeon; Gwon, Hyeon-Cheol; Hahn, Joo-Yong
2017-04-03
A cardioprotective role of morphine acting via opioid receptors has been demonstrated, and previous preclinical studies have reported that morphine could reduce reperfusion injury and myocardial infarct size in a way similar to that of ischemic periconditioning. This study aimed to evaluate the effect of intracoronary morphine on myocardial infarct size in patients with ST-elevation myocardial infarction undergoing primary percutaneous coronary intervention. This study was designed as a 2-center, prospective, randomized, open-label, blinded end point trial. A total of 91 ST-elevation myocardial infarction patients with thrombolysis in myocardial infarction flow grade of 0 to 1 undergoing primary percutaneous coronary intervention were randomly assigned to a morphine or control group at a 1:1 ratio. The morphine group received 3 mg of morphine sulfate diluted with 3 mL of normal saline, and the control group received 3 mL of normal saline into a coronary artery immediately after restoration of coronary flow. The primary end point was myocardial infarct size assessed by cardiac magnetic resonance imaging The cardiac magnetic resonance images were evaluated for 42 and 38 patients in the morphine and control groups, respectively. Myocardial infarct size was not different between the 2 groups (25.6±11.2% versus 24.6±10.5%, P =0.77), nor was the extent of microvascular obstruction or myocardial salvage index (6.0±6.3% versus 5.1±4.6%, P =0.91; 31.1±15.2% versus 30.3±10.9%, P =0.75, respectively). There was no difference in peak creatine kinase-MB level, final thrombolysis in myocardial infarction flow, myocardial brush grade, or complete resolution of ST-segment. Intracoronary morphine administration could not reduce myocardial infarct size in ST-elevation myocardial infarction patients undergoing primary percutaneous coronary intervention. URL: http://www.clinicaltrials.gov. Unique identifier: NCT01738100. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.
Role of calcium in phosphatidylserine externalisation in red blood cells from sickle cell patients.
Weiss, Erwin; Rees, David Charles; Gibson, John Stanley
2011-01-01
Phosphatidylserine exposure occurs in red blood cells (RBCs) from sickle cell disease (SCD) patients and is increased by deoxygenation. The mechanisms responsible remain unclear. RBCs from SCD patients also have elevated cation permeability, and, in particular, a deoxygenation-induced cation conductance which mediates Ca(2+) entry, providing an obvious link with phosphatidylserine exposure. The role of Ca(2+) was investigated using FITC-labelled annexin. Results confirmed high phosphatidylserine exposure in RBCs from SCD patients increasing upon deoxygenation. When deoxygenated, phosphatidylserine exposure was further elevated as extracellular [Ca(2+)] was increased. This effect was inhibited by dipyridamole, intracellular Ca(2+) chelation, and Gardos channel inhibition. Phosphatidylserine exposure was reduced in high K(+) saline. Ca(2+) levels required to elicit phosphatidylserine exposure were in the low micromolar range. Findings are consistent with Ca(2+) entry through the deoxygenation-induced pathway (P(sickle)), activating the Gardos channel. [Ca(2+)] required for phosphatidylserine scrambling are in the range achievable in vivo.
Marquart, Tyler J; Wu, Judy; Lusis, Aldons J; Baldán, Ángel
2013-03-01
To determine the efficacy of long-term anti-miR-33 therapy on the progression of atherosclerosis in high-fat, high-cholesterol-fed Ldlr(-/-) mice. Ldlr(-/-) mice received saline, or control or anti-miR-33 oligonucleotides once a week for 14 weeks. The treatment was effective, as measured by reduced levels of hepatic miR-33 and increased hepatic expression of miR-33 targets. Analysis of plasma samples revealed an initial elevation in high-density lipoprotein cholesterol after 2 weeks of treatment that was not sustained by the end of the experiment. Additionally, we found a significant increase in circulating triglycerides in anti-miR-33-treated mice, compared with controls. Finally, examination of atheromata revealed no significant changes in the size or composition of lesions between the 3 groups. Prolonged silencing of miR-33 fails to maintain elevated plasma high-density lipoprotein cholesterol and does not prevent the progression of atherosclerosis in Ldlr(-/-) mice.
Maharana, Dusmant; Das, Priya Brata; Verlecar, Xivanand N; Pise, Navnath M; Gauns, Manguesh
2015-12-01
Oxidative stress parameters in relation to temperature and other factors have been analysed in Hypnea musciformis, the red seaweed from Anjuna beach, Goa, with an aim to understand its susceptibility to the changing seasons. The results indicate that elevated temperature, sunshine and dessication during peak summer in May enhanced the activity of lipid peroxide, hydrogen peroxide and antioxidants such as catalase, glutathione and ascorbic acid. Statistical tests using multivariate analysis of variance and correlation analysis showed that oxidative stress and antioxidants maintain significant relation with temperature, salinity, sunshine and pH at an individual or interactive level. The dissolved nitrates, phosphates and biological oxygen demand in ambient waters and the trace metals in seaweeds maintained sufficiently low values to provide any indication that could exert contaminant oxidative stress responses. The present field studies suggest that elevated antioxidant content in H. musciformis offer sufficient relief to sustain against harsh environmental stresses for its colonization in the rocky intertidal zone.
Interpretation of time series (salinity and temperature) layers in North Atlantic from 1950 to 2011
NASA Astrophysics Data System (ADS)
Rubchenia, A.; Popov, A.; Fedorova, A.; Lebedev, N.
2012-04-01
On the basis of long period data series (1950-2011) form various sources (National Oceanographic Data Center (NOAD) (www.nodc.noaa.gov), WOD09 database and data from ARGO project) 10 boxes in North Atlantic were selected. Location of boxes was determined by circulation pattern in North Atlantic and Euro-Arctic Seas. For further analysis two "seasons" was selected: "cold season" (October-May) and "warm season" (June-September). Data verification was made. Analysis of data series clearly show the "Great Salinity Anomaly" (so-called GSA) in 1960-70th, 1980th and 1990th. Trends of salinity and temperature data series were calculated. Spectral analysis allow us to calculate periodicity from 2 to 22 years. Boxes situated in regions with Arctic waters have singularity showed through domination of high frequency oscillation during propagation to South. In Fram Strait salinity fluctuates with periods 9..11 and 20 years, the same period was calculated using temperature data series. In Denmark Strait there are oscillations of temperature with specific period from 4 to 7 years. Range of variability vary. For salinity it is 0.4..4.6 psu, for temperature it is 0.04..5.5C. In salinity data series from boxes with surface Arctic waters noticed clear minimums connected with GSAs. Trends in Denmark Strait and Fram strait in the end of 2000th are negative at different levels. Since 1975 to 2001 salinity near the southern part of Greenland was increased, since 2001 - decreased. But temperature was raised from 0.04 in 1989 to 5.59 in 2010. Thermohaline characteristics of water masses which has Atlantic origin oscillated with period near 20 years. Salinity near Newfoundland was decreased since 2005. In Farrero-Shetland straits salinity trend is positive since at 100m level, Salinity rising from 1970th to 2006 is about 0.3 psu were noticed. Oscillations with period 2..4 years is weak. But at 800m layer salinity oscillations are different, since 1990 there is not significant oscillations at all. Temperature trend at this level is negative since 1950th. Salinity at 100-300 level at Station M area described with negative trend since 1960 to 1993, in both "seasons". Next, up to 2010 salinity is increasing, but in 2011 salinity dramatically decreased. Main oscillations have periods 2..3 years, 4..5 years and 20 years. At 800m level oscillations are very weak. Temperature is increased since 1995 in surface layer and since 2002 in deeper levels. At all levels temperature dramatically decreased after 2010. In central part of Greenland Sea ("Cupola area") dominated oscillations with period 4 years (1950-60th), 5..7 years (1970th) and 9 years (after 1979). In "cold season" oscillation with 11 years traced. Salinity trend is positive at all levels during last 10-15 years. Salinity and temperature were increased at 800m level up to 2006. It could lead to termination of deep water formation. Since 2006 temperature decreased, especially in "cold season". Salinity trend in West Spitsbergen Current is positive since 1996 at surface and sine 1978 at deeper levels. Temperature was increased since 1965 to 2006 in surface layer, but since 2006 in "warm season" temperature is decreasing at all layers. Main oscillations is 4..5 years, 6..7 years and 9..11 years.
Cahoon, D.R.
2003-01-01
Hurricanes can be important agents of geomorphic change in coastal marshes and mangrove forests. Hurricanes can cause large-scale redistribution of sediments within the coastal environment resulting in sedimentation, erosion, disruption of vegetated substrates, or some combination of these processes in coastal wetlands. It has been proposed that such sediment pulsing events are important at maintaining wetland sediment elevations in sediment-poor settings with high rates of relative sea-level rise, such as the Mississippi River Delta. But do these pulsing events result in a net gain in sediment elevation even when substantial amounts of sediment are deposited? Clearly sediment erosion and scour would result in a loss of elevation. But will a substantial sediment deposit on poorly consolidated sediments always result in a net gain in elevation? If the wetland vegetation is killed by wind, tidal surge, or the introduction of saline water, will there be a collapse of sediment elevation in the absence of root production and ongoing decomposition of root matter? During the past decade several wetlands where my colleagues and I have monitored sedimentation and elevation change have been struck by one to several hurricanes. This paper describes the range of sediment elevation responses to hurricane strikes, the suggested mechanisms driving those responses, the implications for estimating long-term trends in relative sea-level rise, and future research needs for improving our understanding of the role that major storms play in wetland sediment elevation dynamics. For many wetlands the change in sediment elevation was directly proportional to the amount of sediment deposited by the storm. But surprisingly, there was a loss of elevation in some wetlands with substantial sediment deposits. In these wetlands, the impact of the storm was either direct (sedimentation and compaction) or indirect (vegetation death), and the effect on sediment elevation was either permanent or temporary. For example, 2 cm of sediment deposited by Hurricane Andrew on a healthy salt marsh in south Louisiana had a direct and positive effect on sediment elevation. But in a deteriorated salt marsh a 3 cm thick sediment deposit was associated with a permanent loss in elevation (we have monitored this site for 10 years). The apparent mechanism driving elevation loss was compaction of the weakened substrate by the weight of the sediment deposit, the storm surge waters, or both. Clearly, storm-related sediment pulses are not going to save this marsh from becoming submerged by rising sea level. A temporary loss in elevation, as much as 2 cm, was observed in a North Carolina salt marsh with a highly organic substrate after each of 3 successive hurricanes even when sediment was deposited. The loss in elevation was apparently related to degassing of the chronically flooded substrate while the rebound in elevation was apparently related to a temporary drawdown of marsh water levels. Interestingly, sediment elevation increased after Hurricane Dennis in 1999, although the increase was less than the thickness of the sediment deposit. Further research is required to determine the mechanisms driving storm-related elevation change (i.e., compaction and expansion) in this marsh. There were two marshes where the gain in sediment elevation was greater than the thickness of the sediment deposit, but the effect was short-lived. In a high salt marsh in southern California, we hypothesize that the temporary spike in elevation was related to the flushing of salts from the hypersaline soils, which enhanced root growth that led to an increase in elevation. In a marsh with a highly organic substrate in north Florida, temporary increases in elevation (as much as 2 cm) greater than the thickness of the sediment deposit were apparently related to groundwater fluxes, which may have been influenced by enhanced runoff from storm rainfall. Lastly, Hurricane Mitch
The Effect of Geraniol on Liver Regeneration After Hepatectomy in Rats.
Canbek, Mediha; Uyanoglu, Mustafa; Canbek, Selcuk; Ceyhan, Emre; Ozen, Ahmet; Durmus, Basak; Turgak, Ozge
2017-01-01
Geraniol is a monoterpenoid alcohol that has a hepatoprotective effect. We investigated the regenerative effects of geraniol in rats after a 70% partial hepatectomy (PH). Using Wistar albino rats, nine groups were created: Group I was the control group, while the remaining groups received a single intraperitoneal dose of saline, Silymarin, or geraniol after PH. A 70% PH was performed on all groups except for groups II and III. Blood serum samples were obtained for alanine amino transferase (ALT) analysis. Then liver tissues were harvested for histological and real-time polymerase chain reaction (PCR) analyses. Tumor necrosis factor-α (TNFα) and interleukin 6 (IL6) gene expression were examined 24 and 48 h after PH. ALT levels were found to be statistically significantly increased in all PH-treated groups. TNFα and IL6 gene expression levels were elevated in geraniol-treated groups. Histological evaluation revealed a hepatoprotective effect for geraniol-treated groups. Our results suggest that geraniol plays a significant role during liver regeneration, which involves the elevated expression of TNFα and IL6 48 h after PH. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.
NASA Astrophysics Data System (ADS)
Smith, Anthony J.
2008-09-01
Groundwater beneath the Ord River Irrigation Area (ORIA) in northern Australia has risen in elevation by 10-20 m during the past 40 years with attendant concerns about water logging and soil salinization. Persistent groundwater accession has been attributed to excessive irrigation and surface water leakage; however, analysis of daily water-table records from the past 10 years yielded a contrary result. On a seasonal basis, water-table elevation typically fell during irrigation (dry) seasons and rose during fallow (wet) seasons, conflicting with the conventional view that irrigation and not rainfall must be the dominant control on groundwater accession. Previous investigations of unexpectedly large infiltration losses through the cracking clay soils provide a plausible explanation for the apparent conundrum. Because rainfall is uncontrolled and occurs independently of the soil moisture condition, there is greater opportunity for incipient ponding and rapid infiltration through preferred flow pathways. In contrast, irrigation is scheduled when needed and applications are stopped after soil wetting is achieved. Contemporary groundwater management in the ORIA is focused on improving irrigation efficiency during dry seasons but additional opportunities may exist to improve groundwater conditions and salinity risk through giving equal attention to the wet-season water balance.
Guerrero, Raul A; Piola, Alberto R; Fenco, Harold; Matano, Ricardo P; Combes, Vincent; Chao, Yi; James, Corinne; Palma, Elbio D; Saraceno, Martin; Strub, P Ted
2014-11-01
Satellite-derived sea surface salinity (SSS) data from Aquarius and SMOS are used to study the shelf-open ocean exchanges in the western South Atlantic near 35°S. Away from the tropics, these exchanges cause the largest SSS variability throughout the South Atlantic. The data reveal a well-defined seasonal pattern of SSS during the analyzed period and of the location of the export of low-salinity shelf waters. In spring and summer, low-salinity waters over the shelf expand offshore and are transferred to the open ocean primarily southeast of the river mouth (from 36°S to 37°30'S). In contrast, in fall and winter, low-salinity waters extend along a coastal plume and the export path to the open ocean distributes along the offshore edge of the plume. The strong seasonal SSS pattern is modulated by the seasonality of the along-shelf component of the wind stress over the shelf. However, the combined analysis of SSS, satellite-derived sea surface elevation and surface velocity data suggest that the precise location of the export of shelf waters depends on offshore circulation patterns, such as the location of the Brazil Malvinas Confluence and mesoscale eddies and meanders of the Brazil Current. The satellite data indicate that in summer, mixtures of low-salinity shelf waters are swiftly driven toward the ocean interior along the axis of the Brazil/Malvinas Confluence. In winter, episodic wind reversals force the low-salinity coastal plume offshore where they mix with tropical waters within the Brazil Current and create a warmer variety of low-salinity waters in the open ocean. Satellite salinity sensors capture low-salinity detrainment events from shelves SW Atlantic low-salinity detrainments cause highest basin-scale variability In summer low-salinity detrainments cause extended low-salinity anomalies.
Guerrero, Raul A; Piola, Alberto R; Fenco, Harold; Matano, Ricardo P; Combes, Vincent; Chao, Yi; James, Corinne; Palma, Elbio D; Saraceno, Martin; Strub, P Ted
2014-01-01
Satellite-derived sea surface salinity (SSS) data from Aquarius and SMOS are used to study the shelf-open ocean exchanges in the western South Atlantic near 35°S. Away from the tropics, these exchanges cause the largest SSS variability throughout the South Atlantic. The data reveal a well-defined seasonal pattern of SSS during the analyzed period and of the location of the export of low-salinity shelf waters. In spring and summer, low-salinity waters over the shelf expand offshore and are transferred to the open ocean primarily southeast of the river mouth (from 36°S to 37°30′S). In contrast, in fall and winter, low-salinity waters extend along a coastal plume and the export path to the open ocean distributes along the offshore edge of the plume. The strong seasonal SSS pattern is modulated by the seasonality of the along-shelf component of the wind stress over the shelf. However, the combined analysis of SSS, satellite-derived sea surface elevation and surface velocity data suggest that the precise location of the export of shelf waters depends on offshore circulation patterns, such as the location of the Brazil Malvinas Confluence and mesoscale eddies and meanders of the Brazil Current. The satellite data indicate that in summer, mixtures of low-salinity shelf waters are swiftly driven toward the ocean interior along the axis of the Brazil/Malvinas Confluence. In winter, episodic wind reversals force the low-salinity coastal plume offshore where they mix with tropical waters within the Brazil Current and create a warmer variety of low-salinity waters in the open ocean. Key Points Satellite salinity sensors capture low-salinity detrainment events from shelves SW Atlantic low-salinity detrainments cause highest basin-scale variability In summer low-salinity detrainments cause extended low-salinity anomalies PMID:26213672
Remote Sensing Soil Salinity Map for the San Joaquin Vally, California
NASA Astrophysics Data System (ADS)
Scudiero, E.; Skaggs, T. H.; Anderson, R. G.; Corwin, D. L.
2015-12-01
Soil salinization is a major natural hazard to worldwide agriculture. We present a remote imagery approach that maps salinity within a range (i.e., salinities less than 20 dS m-1, when measured as the electrical conductivity of the soil saturation extract), accuracy, and resolution most relevant to agriculture. A case study is presented for the western San Joaquin Valley (WSJV), California, USA (~870,000 ha of farmland) using multi-year Landsat 7 ETM+ canopy reflectance and the Canopy Response Salinity Index (CRSI). Highly detailed salinity maps for 22 fields (542 ha) established from apparent soil electrical conductivity directed sampling were used as ground-truth (sampled in 2013), totaling over 5000 pixels (30×30 m) with salinity values in the range of 0 to 35.2 dS m-1. Multi-year maximum values of CRSI were used to model soil salinity. In addition, soil type, elevation, meteorological data, and crop type were evaluated as covariates. The fitted model (R2=0.73) was validated: i) with a spatial k-folds (i.e., leave-one-field-out) cross-validation (R2=0.61), ii) versus salinity data from three independent fields (sampled in 2013 and 2014), and iii) by determining the accuracy of the qualitative classification of white crusted land as extremely-saline soils. The effect of land use change is evaluated over 2396 ha in the Broadview Water District from a comparison of salinity mapped in 1991 with salinity predicted in 2013 from the fitted model. From 1991 to 2013 salinity increased significantly over the selected study site, bringing attention to potential negative effects on soil quality of shifting from irrigated agriculture to fallow-land. This is cause for concern since over the 3 years of California's drought (2010-2013) the fallow land in the WSJV increased from 12.7% to 21.6%, due to drastic reduction in water allocations to farmers.
Juraimi, Abdul Shukor; Rafii, M. Y.; Abdul Hamid, Azizah
2015-01-01
13 selected purslane accessions were subjected to five salinity levels 0, 8, 16, 24, and 32 dS m−1. Salinity effect was evaluated on the basis of biomass yield reduction, physiological attributes, and stem-root anatomical changes. Aggravated salinity stress caused significant (P < 0.05) reduction in all measured parameters and the highest salinity showed more detrimental effect compared to control as well as lower salinity levels. The fresh and dry matter production was found to increase in Ac1, Ac9, and Ac13 from lower to higher salinity levels but others were badly affected. Considering salinity effect on purslane physiology, increase in chlorophyll content was seen in Ac2, Ac4, Ac6, and Ac8 at 16 dS m−1 salinity, whereas Ac4, Ac9, and Ac12 showed increased photosynthesis at the same salinity levels compared to control. Anatomically, stem cortical tissues of Ac5, Ac9, and Ac12 were unaffected at control and 8 dS m−1 salinity but root cortical tissues did not show any significant damage except a bit enlargement in Ac12 and Ac13. A dendrogram was constructed by UPGMA based on biomass yield and physiological traits where all 13 accessions were grouped into 5 clusters proving greater diversity among them. The 3-dimensional principal component analysis (PCA) has also confirmed the output of grouping from cluster analysis. Overall, salinity stressed among all 13 purslane accessions considering biomass production, physiological growth, and anatomical development Ac9 was the best salt-tolerant purslane accession and Ac13 was the most affected accession. PMID:25802833
The effect of hyperbaric oxygen treatment on aspiration pneumonia.
Sahin, Sevtap Hekimoglu; Kanter, Mehmet; Ayvaz, Suleyman; Colak, Alkin; Aksu, Burhan; Guzel, Ahmet; Basaran, Umit Nusret; Erboga, Mustafa; Ozcan, Ali
2011-08-01
We have studied whether hyperbaric oxygen (HBO) prevents different pulmonary aspiration materials-induced lung injury in rats. The experiments were designed in 60 Sprague-Dawley rats, ranging in weight from 250 to 300 g, randomly allotted into one of six groups (n = 10): saline control, Biosorb Energy Plus (BIO), hydrochloric acid (HCl), saline + HBO treated, BIO + HBO treated, and HCl + HBO treated. Saline, BIO, HCl were injected into the lungs in a volume of 2 ml/kg. A total of seven HBO sessions were performed at 2,4 atm 100% oxygen for 90 min at 6-h intervals. Seven days later, rats were sacrificed, and both lungs in all groups were examined biochemically and histopathologically. Our findings show that HBO inhibits the inflammatory response reducing significantly (P < 0.05) peribronchial inflammatory cell infiltration, alveolar septal infiltration, alveolar edema, alveolar exudate, alveolar histiocytes, interstitial fibrosis, granuloma, and necrosis formation in different pulmonary aspiration models. Pulmonar aspiration significantly increased the tissue HP content, malondialdehyde (MDA) levels and decreased (P < 0.05) the antioxidant enzyme (SOD, GSH-Px) activities. HBO treatment significantly (P < 0.05) decreased the elevated tissue HP content, and MDA levels and prevented inhibition of SOD, and GSH-Px (P < 0.05) enzymes in the tissues. Furthermore, there is a significant reduction in the activity of inducible nitric oxide synthase, TUNEL and arise in the expression of surfactant protein D in lung tissue of different pulmonary aspiration models with HBO therapy. It was concluded that HBO treatment might be beneficial in lung injury, therefore, shows potential for clinical use.
Snedden, Gregg A.; Swenson, Erick M.
2012-01-01
Hourly time-series salinity and water-level data are collected at all stations within the Coastwide Reference Monitoring System (CRMS) network across coastal Louisiana. These data, in addition to vegetation and soils data collected as part of CRMS, are used to develop a suite of metrics and indices to assess wetland condition in coastal Louisiana. This document addresses the primary objectives of the CRMS hydrologic analytical team, which were to (1) adopt standard time-series analytical techniques that could effectively assess spatial and temporal variability in hydrologic characteristics across the Louisiana coastal zone on site, project, basin, and coastwide scales and (2) develop and apply an index based on wetland hydrology that can describe the suitability of local hydrology in the context of maximizing the productivity of wetland plant communities. Approaches to quantifying tidal variability (least squares harmonic analysis) and partitioning variability of time-series data to various time scales (spectral analysis) are presented. The relation between marsh elevation and the tidal frame of a given hydrograph is described. A hydrologic index that integrates water-level and salinity data, which are collected hourly, with vegetation data that are collected annually is developed. To demonstrate its utility, the hydrologic index is applied to 173 CRMS sites across the coast, and variability in index scores across marsh vegetation types (fresh, intermediate, brackish, and saline) is assessed. The index is also applied to 11 sites located in three Coastal Wetlands Planning, Protection and Restoration Act projects, and the ability of the index to convey temporal hydrologic variability in response to climatic stressors and restoration measures, as well as the effect that this community may have on wetland plant productivity, is illustrated.
Terzioğlu, Berna; Kaleli, Melisa; Aydın, Banu; Ketenci, Sema; Cabadak, Hülya; Gören, M Zafer
2013-08-01
The dysregulation of hypothalamic-pituitary-adrenal axis and noradrenergic, serotonergic and glutamatergic systems are thought to be involved in the pathophysiology of post-traumatic stress disorder. The effect of selective M1 muscarinic receptor antagonist, pirenzepine on anxiety indices was investigated by using elevated plus maze, following exposure to trauma reminder. Upon receiving the approval of ethics committee, Sprague-Dawley rats were exposed to dirty cat litter (trauma) for 10 min and 1 week later, the rats confronted to a trauma reminder (clean litter). The rats also received intraperitoneal pirenzepine (1 or 2 mg/kg/day) or saline for 8 days. Noradrenaline (NA) concentration in the rostral pons was analyzed by HPLC with electrochemical detection. The anxiety indices of the rats subjected to the trauma reminder were increased when compared to control rats (p < 0.05). Pirenzepine treatment in traumatized rats displayed similar anxiety indices of non-traumatized rats treated with physiological saline. Although freezing time was prolonged with pirenzepine in traumatized groups the change was not found statistically significant. The NA level was 1.5 ± 0.1 pg/mg in non-traumatized rats and increased to 2.4 ± 0.2 pg/mg in traumatized rats. Bonferroni post hoc test revealed that the NA content of the rostral pons of the traumatized rats treated with physiological saline was significantly higher than the content of other groups (p < 0.01). We conclude that NA content in the rostral pons increases in respect to confrontation to a trauma reminder which can be reversed by M1 antagonist pirenzepine indicating the roles of M1 receptors.
Yang, Lei; Zhao, Xiaoju; Zhu, Hong; Paul, Matthew; Zu, Yuangang; Tang, Zhonghua
2014-01-01
Trehalose (Tre) has been reported to play a critical role in plant response to salinity and the involved mechanisms remain to be investigated in detail. Here, the putative roles of Tre in regulation of ionic balance, cellular redox state, cell death were studied in Arabidopsis under high salt condition. Our results found that the salt-induced restrictions on both vegetative and reproductive growth in salt-stressed plants were largely alleviated by exogenous supply with Tre. The microprobe analysis of ionic dynamics in the leaf and stem of florescence highlighted the Tre ability to retain K and K/Na ratio in plant tissues to improve salt tolerance. The flow cytometry assay of cellular levels of reactive oxygen species and programmed cell death displayed that Tre was able to antagonized salt-induced damages in redox state and cell death and sucrose did not play the same role with Tre. By comparing ionic distribution in leaf and inflorescence stem (IS), we found that Tre was able to restrict Na transportation to IS from leaves since that the ratio of Na accumulation in leaves relative to IS was largely improved due to Tre. The marked decrease of Na ion and improved sucrose level in IS might account for the promoted floral growth when Tre was included in the saline solution. At the same time, endogenous soluble sugars and antioxidant enzyme activities in the salt-stressed plants were also elevated by Tre to counteract high salt stress. We concluded that Tre could improve Arabidopsis salt resistance with respect to biomass accumulation and floral transition in the means of regulating plant redox state, cell death, and ionic distribution. PMID:25400644
Gleadow, Ros; Pegg, Amelia; Blomstedt, Cecilia K
2016-10-01
Rising sea levels are threatening agricultural production in coastal regions due to inundation and contamination of groundwater. The development of more salt-tolerant crops is essential. Cassava is an important staple, particularly among poor subsistence farmers. Its tolerance to drought and elevated temperatures make it highly suitable for meeting global food demands in the face of climate change, but its ability to tolerate salt is unknown. Cassava stores nitrogen in the form of cyanogenic glucosides and can cause cyanide poisoning unless correctly processed. Previous research demonstrated that cyanide levels are higher in droughted plants, possibly as a mechanism for increasing resilience to oxidative stress. We determined the tolerance of cassava to salt at two different stages of development, and tested the hypothesis that cyanide toxicity would be higher in salt-stressed plants. Cassava was grown at a range of concentrations of sodium chloride (NaCl) at two growth stages: tuber initiation and tuber expansion. Established plants were able to tolerate 100mM NaCl but in younger plants 40mM was sufficient to retard plant growth severely. Nutrient analysis showed that plants were only able to exclude sodium at low concentrations. The foliar cyanogenic glucoside concentration in young plants increased under moderate salinity stress but was lower in plants grown at high salt. Importantly, there was no significant change in the cyanogenic glucoside concentration in the tubers. We propose that the mechanisms for salinity tolerance are age dependent, and that this can be traced to the relative cost of leaves in young and old plants. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology.
Oxidative and antioxidative status in the testes of rats with acute epididymitis.
Kaya, Mete; Boleken, Mehmet Emin; Zeyrek, Fadile; Ozardali, Ilyas; Kanmaz, Turan; Erel, Ozcan; Yücesan, Selçuk
2006-01-01
Epididymitis is an inflammation or infection of the epididymis, a convoluted duct that lies on the posterior surface of the testicle. Oxidative stress due to excessive production of reactive oxygen species in epididymitis, impaired antioxidant defense mechanisms, or both, precipitates a range of pathologies that are currently believed to negatively affect the male reproductive function. How oxidative stress affects the testes is still unknown. We aimed to investigate the oxidative and antioxidative status of testes of rats with unilateral acute Escherichia coli epididymitis. The study included 36 male Wistar albino rats which were divided into three groups. In the epididymitis group (n = 12), an E. coli suspension was injected into the right ductus deferens of rats, and the same amount of saline was injected in the saline groups (n = 12). No surgery was performed in the control group (n = 12) for baseline values. Rats were sacrificed after 24 h and the epididymis and testes removed. The infection was confirmed by histopathologic evaluation and microbiological tests. The oxidative status of testes was evaluated by measuring myeloperoxidase (MPO) activity, and antioxidative status was evaluated by measuring total antioxidant response (TAR) and total antioxidant capacity levels (TAC). MPO activity in both the ipsilateral and contralateral testes of the epididymitis group was significantly higher than those of the saline and control groups (p < 0.05). The TAR and TAC levels in both testes were also significantly elevated in the epididymitis group versus the two other groups (p < 0.05). Acute epididymitis causes an increase of oxidative stress in the ipsilateral and contralateral testes, but this condition is strived for to tolerate the increase of endogenous antioxidants. 2006 S. Karger AG, Basel.
Bhattacharyya, Sudeepa; Pence, Lisa; Beger, Richard; Chaudhuri, Shubhra; McCullough, Sandra; Yan, Ke; Simpson, Pippa; Hennings, Leah; Hinson, Jack; James, Laura
2013-01-01
High doses of acetaminophen (APAP) result in hepatotoxicity that involves metabolic activation of the parent compound, covalent binding of the reactive intermediate N-acetyl-p-benzoquinone imine (NAPQI) to liver proteins, and depletion of hepatic glutathione. Impaired fatty acid β-oxidation has been implicated in previous studies of APAP-induced hepatotoxicity. To better understand relationships between toxicity and fatty acid β-oxidation in the liver in APAP toxicity, metabolomic assays for long chain acylcarnitines were examined in relationship to established markers of liver toxicity, oxidative metabolism, and liver regeneration in a time course study in mice. Male B6C3F1 mice were treated with APAP (200 mg/kg IP) or saline and sacrificed at 1, 2, 4, 8, 24 or 48 h after APAP. At 1 h, hepatic glutathione was depleted and APAP protein adducts were markedly increased. Alanine aminotransferase (ALT) levels were elevated at 4 and 8 h, while proliferating cell nuclear antigen (PCNA) expression, indicative of hepatocyte regeneration, was apparent at 24 h and 48 h. Elevations of palmitoyl, oleoyl and myristoyl carnitine were apparent by 2–4 h, concurrent with the onset of Oil Red O staining in liver sections. By 8 h, acylcarnitine levels were below baseline levels and remained low at 24 and 48 h. A partial least squares (PLS) model suggested a direct association of acylcarnitine accumulation in serum to APAP protein adduct and hepatic glutathione levels in mice. Overall, the kinetics of serum acylcarnitines in APAP toxicity in mice followed a biphasic pattern involving early elevation after the metabolism phases of toxicity and later depletion of acylcarnitines. PMID:24958141
Elevated Cell Wall Chitin in Candida albicans Confers Echinocandin Resistance In Vivo
Lee, Keunsook K.; MacCallum, Donna M.; Jacobsen, Mette D.; Walker, Louise A.; Odds, Frank C.
2012-01-01
Candida albicans cells with increased cell wall chitin have reduced echinocandin susceptibility in vitro. The aim of this study was to investigate whether C. albicans cells with elevated chitin levels have reduced echinocandin susceptibility in vivo. BALB/c mice were infected with C. albicans cells with normal chitin levels and compared to mice infected with high-chitin cells. Caspofungin therapy was initiated at 24 h postinfection. Mice infected with chitin-normal cells were successfully treated with caspofungin, as indicated by reduced kidney fungal burdens, reduced weight loss, and decreased C. albicans density in kidney lesions. In contrast, mice infected with high-chitin C. albicans cells were less susceptible to caspofungin, as they had higher kidney fungal burdens and greater weight loss during early infection. Cells recovered from mouse kidneys at 24 h postinfection with high-chitin cells had 1.6-fold higher chitin levels than cells from mice infected with chitin-normal cells and maintained a significantly reduced susceptibility to caspofungin when tested in vitro. At 48 h postinfection, caspofungin treatment induced a further increase in chitin content of C. albicans cells harvested from kidneys compared to saline treatment. Some of the recovered clones had acquired, at a low frequency, a point mutation in FKS1 resulting in a S645Y amino acid substitution, a mutation known to confer echinocandin resistance. This occurred even in cells that had not been exposed to caspofungin. Our results suggest that the efficacy of caspofungin against C. albicans was reduced in vivo due to either elevation of chitin levels in the cell wall or acquisition of FKS1 point mutations. PMID:21986821
NASA Astrophysics Data System (ADS)
Marohn, C.; Distel, A.; Dercon, G.; Wahyunto; Tomlinson, R.; Noordwijk, M. v.; Cadisch, G.
2012-09-01
The Indian Ocean tsunami of December 2004 had far reaching consequences for agriculture in Aceh province, Indonesia, and particularly in Aceh Barat district, 150 km from the seaquake epicentre. In this study, the spatial distribution and temporal dynamics of soil and groundwater salinity and their impact on tree crops were monitored in Aceh Barat from 2006 to 2008. On 48 sampling points along ten transects, covering 40 km of coastline, soil and groundwater salinity were measured and related to mortality and yield depression of the locally most important tree crops. Given a yearly rainfall of over 3000 mm, initial groundwater salinity declined rapidly from over 10 to less than 2 mS cm-1 within two years. On the other hand, seasonal dynamics of the groundwater table in combination with intrusion of saline water into the groundwater body led to recurring elevated salinity, sufficient to affect crops. Tree mortality and yield depression in the flooded area varied considerably between tree species. Damage to coconut (65% trees damaged) was related to tsunami run-up height, while rubber (50% trees damaged) was mainly affected by groundwater salinity. Coconut yields (-35% in average) were constrained by groundwater Ca2+ and Mg2+, while rubber yields (-65% on average) were related to groundwater chloride, pH and soil sodium. These findings have implications on planting deep-rooted tree crops as growth will be constrained by ongoing oscillations of the groundwater table and salinity.
Does increased salinity influence the competitive outcome of two producer species?
Venâncio, C; Anselmo, E; Soares, A; Lopes, I
2017-02-01
Within the context of global climate changes, it is expected that low-lying coastal freshwater ecosystems will face seawater intrusion with concomitant increase in salinity levels. Increased salinity may provoke disruption of competitive relationships among freshwater species. However, species may be capable of acclimating to salinity, which, in turn, may influence the resilience of ecosystems. Accordingly, this work aimed at assessing the effects of multigenerational exposure to low levels of salinity in the competitive outcome of two species of green microalgae: Raphidocelis subcapitata and Chlorella vulgaris. To attain this, three specific objectives were delineated: (1) compare the toxicity of natural seawater (SW) and NaCl (as a surrogate of SW) to the two microalgae, (2) determine the capacity of the two microalgae species to acclimate to low salinity levels, and (3) assess the influence of exposure to low salinity levels in the competitive outcome of the two microalgae. Results revealed SW to be slightly less toxic than NaCl for the two microalgae. The EC 25,72 h for growth rate was 4.63 and 10.3 mS cm -1 for R. subcapitata and 6.94 and 15.4 mS cm -1 for C. vulgaris, respectively for NaCl and SW. Both algae were capable of acclimating to low levels of salinity, but C. vulgaris seemed to acclimate faster than R. subcapitata. When exposed in competition, under control conditions, the growth rates of C. vulgaris were lower than those of R. subcapitata. However, C. vulgaris was capable of acquiring competitive advantage equaling or surpassing the growth rate of R. subcapitata with the addition of NaCl or SW, respectively. The multigenerational exposure to low levels of salinity influenced the competitive outcome of the two algae both under control and salinity exposure. These results suggest that long-term exposure to low salinity stress can cause shifts in structure of algae communities and, therefore, should not be neglected since algae are at the basis of food web constituting important energetic resources to higher trophic levels.
Salinity and temperature tolerance of brown-marbled grouper Epinephelus fuscoguttatus.
Cheng, Sha-Yen; Chen, Chih-Sung; Chen, Jiann-Chu
2013-04-01
Grouper have to face varied environmental stressors as a result of drastic changes to water conditions during the storm season. We aimed to test the response of brown-marbled grouper to drastic and gradual changes in temperature and salinity to understand the grouper's basic stress response. The results can improve the culture of grouper. Brown-marbled grouper, Epinephelus fuscoguttatus (6.2 ± 0.8 g) were examined for temperature and salinity tolerances at nine different environmental regimes (10, 20, and 33 ‰ combined with 20, 26 and 32 °C), in which the fish were subjected to both gradual and sudden changes in temperature and salinity. The critical thermal maximum (50 % CTMAX) and the upper incipient lethal temperature (UILT) were in the ranges of 35.9-38.3 and 32.7-36.5 °C, respectively. The critical thermal minimum (50 % CTMIN) and the lower incipient lethal temperature (LILT) were in the ranges of 9.8-12.2 and 14.9-22.3 °C, respectively. The critical salinity maximum (50 % CSMAX) and the upper incipient lethal salinity (UILS) were in the ranges of 67.0-75.5 and 54.2-64.8 ‰, respectively. Fish at temperature of 20 °C and a salinity of 33 ‰ tolerated temperatures as low as 10 °C when the temperature was gradually decreased. Fish acclimated at salinities of 10-33 ‰ and a temperature of 32 °C tolerated salinities of as high as 75-79 ‰. All fish survived from accumulating salinity after acute transfer to 20, 10, 5, and 3 ‰. But all fish died while transferred to 0 ‰. Relationships among the UILT, LILT, 50 % CTMAX, 50 % CTMIN, UILS, 50 % CSMAX, salinity, and temperature were examined. The grouper's temperature and salinity tolerance elevated by increasing acclimation temperature and salinity. On the contrary, the grouper's temperature and salinity tolerance degraded by decreasing acclimation temperature and salinity. The tolerance of temperature and salinity on grouper in gradual changes were higher than in drastic changes.
Modifying the release of leuprolide from spray dried OED microparticles.
Alcock, R; Blair, J A; O'Mahony, D J; Raoof, A; Quirk, A V
2002-08-21
A range of oligosaccharide ester derivatives (OEDs) have been designed as drug delivery matrices for controlled release. The synthetic hormone analogue, leuprolide, was encapsulated within these matrices using hydrophobic ion pairing and solvent spray drying. The particles produced modified the release of leuprolide in vitro (dissolution in phosphate buffered saline) and in vivo (subcutaneous and pulmonary delivery in the rat). Release rate was dependent on drug loading and could be manipulated by choice of OED and by combining different OEDs in different ratios. Leuprolide encapsulated in the OEDs retained biological activity as evidenced by elevation in plasma luteinising hormone levels following subcutaneous injection of leuprolide recovered from OED particles in vitro prior to in vivo administration.
Neonatal exposure to fenoterol and betamethasone: effects on the behavioral development in the rat.
Pitzer, Martina; Schmidt, Martin H
2009-01-01
We investigated longitudinally the behavioral development in the rat following exposure to beta-agonists and glucocorticoids (GC). Neonatal rats received either 1 mg/kg fenoterol (FEN), 0.3 mg/kg betamethasone (BET), or saline (SAL). Weanling and young adult rats were tested in the open field, the elevated-plus maze, and the water maze. FEN-treated as well as BET-treated animals displayed increased anxiety-like behavior. Furthermore, BET-treated adult animals showed a reduced locomotor activity. An enhanced 24-h memory in the water maze in both treatment groups may be facilitated by emotional arousal due to the increased anxiety levels. The possible neurobiological underpinnings are discussed in detail.
The effects of salinity in the soil water balance: A Budyko's approach
NASA Astrophysics Data System (ADS)
Perri, S.; Viola, F.; Molini, A.
2017-12-01
Soil degradation and water scarcity pose important constraints on productivity and development of arid and semi-arid countries. Among the main causes of loss of soil fertility, aridification and soil salinization are deeply connected threats enhanced by climate change. Assessing water availability is fundamental for a large number of applications especially in arid regions. An approach often adopted to estimate the long-term rainfall partitioning into evapotranspiration and runoff is the Budyko's curve. However, the classical Budyko framework might not be able to properly reproduce the water balance in salt affected basins, especially under elevated soil salinization conditions. Salinity is a limiting factor for plant transpiration (as well as growth) affecting both short and long term soil moisture dynamics and ultimately the hydrologic balance. Soluble salts cause a reduction of soil water potential similar to the one arising from droughts, although plant adaptations to soil salinity show extremely different traits and can vary from species to species. In a similar context, the salt-tolerance plants are expected to control the amount of soil moisture lost to transpiration in saline soils, also because salinity reduces evaporation. We propose a simple framework to include the effects of salinization on the surface energy and water balance within a simple Budyko approach. By introducing the effects of salinity in the stochastic water balance we are able to include the influence of vegetation type (i.e. in terms of salt-tolerance) on evapotranspiration-runoff partitioning under different climatic conditions. The water balance components are thus compared to data obtained from arid salt-affected regions.
Porewater salinity reveals past lake-level changes in Lake Van, the Earth's largest soda lake.
Tomonaga, Yama; Brennwald, Matthias S; Livingstone, David M; Kwiecien, Olga; Randlett, Marie-Ève; Stockhecke, Mona; Unwin, Katie; Anselmetti, Flavio S; Beer, Jürg; Haug, Gerald H; Schubert, Carsten J; Sturm, Mike; Kipfer, Rolf
2017-03-22
In closed-basin lakes, sediment porewater salinity can potentially be used as a conservative tracer to reconstruct past fluctuations in lake level. However, until now, porewater salinity profiles did not allow quantitative estimates of past lake-level changes because, in contrast to the oceans, significant salinity changes (e.g., local concentration minima and maxima) had never been observed in lacustrine sediments. Here we show that the salinity measured in the sediment pore water of Lake Van (Turkey) allows straightforward reconstruction of two major transgressions and a major regression that occurred during the last 250 ka. We observed strong changes in the vertical salinity profiles of the pore water of the uppermost 100 m of the sediments in Lake Van. As the salinity balance of Lake Van is almost at steady-state, these salinity changes indicate major lake-level changes in the past. In line with previous studies on lake terraces and with seismic and sedimentological surveys, we identify two major transgressions of up to +105 m with respect to the current lake level at about 135 ka BP and 248 ka BP starting at the onset of the two previous interglacials (MIS5e and MIS7), and a major regression of about -200 m at about 30 ka BP during the last ice age.
Saranjampour, Parichehr; Vebrosky, Emily N; Armbrust, Kevin L
2017-09-01
Salinity has been reported to influence the water solubility of organic chemicals entering marine ecosystems. However, limited data are available on salinity impacts for chemicals potentially entering seawater. Impacts on water solubility would correspondingly impact chemical sorption as well as overall bioavailability and exposure estimates used in the regulatory assessment. The pesticides atrazine, fipronil, bifenthrin, and cypermethrin, as well as the crude oil constituent dibenzothiophene together with 3 of its alkyl derivatives, all have different polarities and were selected as model compounds to demonstrate the impact of salinity on their solubility and partitioning behavior. The n-octanol/water partition coefficient (K OW ) was measured in both distilled-deionized water and artificial seawater (3.2%). All compounds had diminished solubility and increased K OW values in artificial seawater compared with distilled-deionized water. A linear correlation curve estimated salinity may increase the log K OW value by 2.6%/1 log unit increase in distilled water (R 2 = 0.97). Salinity appears to generally decrease the water solubility and increase the partitioning potential. Environmental fate estimates based on these parameters indicate elevated chemical sorption to sediment, overall bioavailability, and toxicity in artificial seawater. These dramatic differences suggest that salinity should be taken into account when exposure estimates are made for marine organisms. Environ Toxicol Chem 2017;36:2274-2280. © 2017 SETAC. © 2017 SETAC.
Rice, Karen C; Hong, Bo; Shen, Jian
2012-11-30
Global sea level is rising, and the relative rate in the Chesapeake Bay region of the East Coast of the United States is greater than the worldwide rate. Sea-level rise can cause saline water to migrate upstream in estuaries and rivers, threatening freshwater habitat and drinking-water supplies. The effects of future sea-level rise on two tributaries of Chesapeake Bay, the James and Chickahominy (CHK) Rivers, were evaluated in order to quantify the salinity change with respect to the magnitude of sea-level rise. Such changes are critical to: 1) local floral and faunal habitats that have limited tolerance ranges to salinity; and 2) a drinking-water supply for the City of Newport News, Virginia. By using the three-dimensional Hydrodynamic-Eutrophication Model (HEM-3D), sea-level rise scenarios of 30, 50, and 100 cm, based on the U.S. Climate Change Science Program for the mid-Atlantic region for the 21st century, were evaluated. The model results indicate that salinity increases in the entire river as sea level rises and that the salinity increase in a dry year is greater than that in a typical year. In the James River, the salinity increase in the middle-to-upper river (from 25 to 50 km upstream of the mouth) is larger than that in the lower and upper parts of the river. The maximum mean salinity increase would be 2 and 4 ppt for a sea-level rise of 50 and 100 cm, respectively. The upstream movement of the 10 ppt isohaline is much larger than the 5 and 20 ppt isohalines. The volume of water with salinity between 10 and 20 ppt would increase greatly if sea level rises 100 cm. In the CHK River, with a sea-level rise of 100 cm, the mean salinity at the drinking-water intake 34 km upstream of the mouth would be about 3 ppt in a typical year and greater than 5 ppt in a dry year, both far in excess of the U.S. Environmental Protection Agency's secondary standard for total dissolved solids for drinking water. At the drinking-water intake, the number of days of salinity greater than 0.1 ppt increases with increasing sea-level rise; during a dry year, 0.1 ppt would be exceeded for more than 100 days with as small a rise as 30 cm. Copyright © 2012 Elsevier Ltd. All rights reserved.
Rice, Karen; Bo Hong,; Jian Shen,
2012-01-01
Global sea level is rising, and the relative rate in the Chesapeake Bay region of the East Coast of the United States is greater than the worldwide rate. Sea-level rise can cause saline water to migrate upstream in estuaries and rivers, threatening freshwater habitat and drinking-water supplies. The effects of future sea-level rise on two tributaries of Chesapeake Bay, the James and Chickahominy (CHK) Rivers, were evaluated in order to quantify the salinity change with respect to the magnitude of sea-level rise. Such changes are critical to: 1) local floral and faunal habitats that have limited tolerance ranges to salinity; and 2) a drinking-water supply for the City of Newport News, Virginia. By using the three-dimensional Hydrodynamic-Eutrophication Model (HEM-3D), sea-level rise scenarios of 30, 50, and 100 cm, based on the U.S. Climate Change Science Program for the mid-Atlantic region for the 21st century, were evaluated. The model results indicate that salinity increases in the entire river as sea level rises and that the salinity increase in a dry year is greater than that in a typical year. In the James River, the salinity increase in the middle-to-upper river (from 25 to 50 km upstream of the mouth) is larger than that in the lower and upper parts of the river. The maximum mean salinity increase would be 2 and 4 ppt for a sea-level rise of 50 and 100 cm, respectively. The upstream movement of the 10 ppt isohaline is much larger than the 5 and 20 ppt isohalines. The volume of water with salinity between 10 and 20 ppt would increase greatly if sea level rises 100 cm. In the CHK River, with a sea-level rise of 100 cm, the mean salinity at the drinking-water intake 34 km upstream of the mouth would be about 3 ppt in a typical year and greater than 5 ppt in a dry year, both far in excess of the U.S. Environmental Protection Agency's secondary standard for total dissolved solids for drinking water. At the drinking-water intake, the number of days of salinity greater than 0.1 ppt increases with increasing sea-level rise; during a dry year, 0.1 ppt would be exceeded for more than 100 days with as small a rise as 30 cm.
López-Hoffman, Laura; Anten, Niels P R; Martínez-Ramos, Miguel; Ackerly, David D
2007-01-01
We have studied the interactive effects of salinity and light on Avicennia germinans mangrove seedlings in greenhouse and field experiments. We hypothesized that net photosynthesis, growth, and survivorship rates should increase more with an increase in light availability for plants growing at low salinity than for those growing at high salinity. This hypothesis was supported by our results for net photosynthesis and growth. Net daily photosynthesis did increase more with increasing light for low-salinity plants than for high-salinity plants. Stomatal conductance, leaf-level transpiration, and internal CO(2) concentrations were lower at high than at low salinity. At high light, the ratio of leaf respiration to assimilation was 2.5 times greater at high than at low salinity. Stomatal limitations and increased respiratory costs may explain why, at high salinity, seedlings did not respond to increased light availability with increased net photosynthesis. Seedling mass and growth rates increased more with increasing light availability at low than at high salinity. Ratios of root mass to leaf mass were higher at high salinity, suggesting that either water or nutrient limitations may have limited seedling growth at high salinity in response to increasing light. The interactive effects of salinity and light on seedling size and growth rates observed in the greenhouse were robust in the field, despite the presence of other factors in the field--such as inundation, nutrient gradients, and herbivory. In the field, seedling survivorship was higher at low than at high salinity and increased with light availability. Interestingly, the positive effect of light on seedling survivorship was stronger at high salinity, indicating that growth and survivorship rates are decoupled. In general, this study demonstrates that environmental effects at the leaf-level also influence whole plant growth in mangroves.
NASA Astrophysics Data System (ADS)
Oxmann, J. F.; Schwendenmann, L.
2014-07-01
Mechanisms governing phosphorus (P) speciation in coastal sediments remain unknown due to the diversity of coastal environments and poor analytical specificity for P phases. We investigated P speciation along salinity gradients comprising diverse ecosystems in a P-enriched estuary. To determine P load effects on P speciation we compared the high P site with a P-unenriched site. To improve analytical specificity, octacalcium phosphate (OCP), authigenic apatite (carbonate fluorapatite; CFAP) and detrital apatite (fluorapatite) were quantitated in addition to Al/Fe-bound P (Al/Fe-P) and Ca-bound P (Ca-P). Sediment pH primarily affected P fractions across ecosystems and independent of the P status. Increasing pH caused a pronounced downstream transition from adsorbed Al/Fe-P to mineral Ca-P. Downstream decline in Al/Fe-P was counterbalanced by the precipitation of Ca-P. This marked upstream-to-downstream switch occurred at near-neutral sediment pH and was enhanced by increased P loads. Accordingly, the site comparison indicated two location-dependent accumulation mechanisms at the P-enriched site, which mainly resulted in elevated Al/Fe-P at pH < 6.6 (upstream; adsorption) and elevated Ca-P at pH > 6.6 (downstream; precipitation). Enhanced Ca-P precipitation by increased loads was also evident from disproportional accumulation of metastable Ca-P (Ca-PMmeta). The average Ca-Pmeta concentration was six-fold, whereas total Ca-P was only twofold higher at the P-enriched site compared to the P-unenriched site. Species concentrations showed that these largely elevated Ca-Pmeta levels resulted from transformation of fertilizer-derived Al/Fe-P to OCP and CFAP due to decreasing acidity from land to the sea. Formation of OCP and CFAP results in P retention in coastal zones, which may lead to substantial inorganic P accumulation by anthropogenic P input in near-shore sediments.
Modern limnology of two lakes in the Tibetan Plateau - evidence from in-situ monitoring
NASA Astrophysics Data System (ADS)
Wang, M.; Li, X.; Lei, L.; He, Y.; Hou, J.
2013-12-01
The mechanisms of climate change in the Tibetan Plateau, known as the Third Pole, receive more and more attention due to its unique geographic location and the influence of multiple climate systems. Among the paleoclimate archives, widespread lakes provide abundant information on past climate changes and have been investigated for decades. Though many high-quality paleolimnological records have been reported in the Tibetan Plateau, little is known about the modern limnological processes in most Tibetan lakes as most lakes are difficult to access and not ready for long-term monitoring. We have installed a series of temperature data logger at different water levels in two Tibetan lakes, Bangong Co and Dagze Co in July 2012 to monitor hourly variability of temperature profile. Bangong Co (33.5°N, 79.8°E, 4245 m asl) is a freshwater lake (salinity ~0.5 g/L) in the westernmost Tibetan Plateau, receiving melt water from mountain glaciers in the basin. Dagze Co (31.9°N, 87.5°E, 4470 m asl) is saline lake (salinity ~15 g/L) in the central Tibetan Plateau, mostly fed by precipitation. In combination with the climate data in the nearby weather stations, we wish to understand the modern limnological processes in the two lakes and their potential effect on the lake biology, sedimentation, and sedimentary biomarkers. Based on the data collected for the first calendar year (Jul 2012 ~ Aug 2013), we anticipate to understand: 1) the influence of climate on the hydrological processes in high elevation lakes; 2) the difference in the metalimnion in meltwater-fed lake (Bangong Co) and precipitation-fed lake (Dagze Co) and their potential effect on the lake biology; 3) the difference in the spring turnover and fall turnover and the effect of meltwater and salinity.
Singh, Dinkar; Yadav, Narendra Singh; Tiwari, Vivekanand; Agarwal, Pradeep K.; Jha, Bhavanath
2016-01-01
About 1000 salt-responsive ESTs were identified from an extreme halophyte Salicornia brachiata. Among these, a novel salt-inducible gene SbSLSP (Salicornia brachiata SNARE-like superfamily protein), showed up-regulation upon salinity and dehydration stress. The presence of cis-regulatory motifs related to abiotic stress in the putative promoter region supports our finding that SbSLSP gene is inducible by abiotic stress. The SbSLSP protein showed a high sequence identity to hypothetical/uncharacterized proteins from Beta vulgaris, Spinacia oleracea, Eucalyptus grandis, and Prunus persica and with SNARE-like superfamily proteins from Zostera marina and Arabidopsis thaliana. Bioinformatics analysis predicted a clathrin adaptor complex small-chain domain and N-myristoylation site in the SbSLSP protein. Subcellular localization studies indicated that the SbSLSP protein is mainly localized in the plasma membrane. Using transgenic tobacco lines, we establish that overexpression of SbSLSP resulted in elevated tolerance to salt and drought stress. The improved tolerance was confirmed by alterations in a range of physiological parameters, including high germination and survival rate, higher leaf chlorophyll contents, and reduced accumulation of Na+ ion and reactive oxygen species (ROS). Furthermore, overexpressing lines also showed lower water loss, higher cell membrane stability, and increased accumulation of proline and ROS-scavenging enzymes. Overexpression of SbSLSP also enhanced the transcript levels of ROS-scavenging and signaling enzyme genes. This study is the first investigation of the function of the SbSLSP gene as a novel determinant of salinity/drought tolerance. The results suggest that SbSLSP could be a potential candidate to increase salinity and drought tolerance in crop plants for sustainable agriculture in semi-arid saline soil. PMID:27313584
Yaish, Mahmoud W; Patankar, Himanshu V; Assaha, Dekoum V M; Zheng, Yun; Al-Yahyai, Rashid; Sunkar, Ramanjulu
2017-03-22
Date palm, as one of the most important fruit crops in North African and West Asian countries including Oman, is facing serious growth problems due to salinity, arising from persistent use of saline water for irrigation. Although date palm is a relatively salt-tolerant plant species, its adaptive mechanisms to salt stress are largely unknown. In order to get an insight into molecular mechanisms of salt tolerance, RNA was profiled in leaves and roots of date palm seedlings subjected to NaCl for 10 days. Under salt stress, photosynthetic parameters were differentially affected; all gas exchange parameters were decreased but the quantum yield of PSII was unaffected while non-photochemical quenching was increased. Analyses of gene expression profiles revealed 2630 and 4687 genes were differentially expressed in leaves and roots, respectively, under salt stress. Of these, 194 genes were identified as commonly responding in both the tissue sources. Gene ontology (GO) analysis in leaves revealed enrichment of transcripts involved in metabolic pathways including photosynthesis, sucrose and starch metabolism, and oxidative phosphorylation, while in roots genes involved in membrane transport, phenylpropanoid biosynthesis, purine, thiamine, and tryptophan metabolism, and casparian strip development were enriched. Differentially expressed genes (DEGs) common to both tissues included the auxin responsive gene, GH3, a putative potassium transporter 8 and vacuolar membrane proton pump. Leaf and root tissues respond differentially to salinity stress and this study has revealed genes and pathways that are associated with responses to elevated NaCl levels and thus may play important roles in salt tolerance providing a foundation for functional characterization of salt stress-responsive genes in the date palm.
Huang, Chun-Yen; Chao, Pei-Lin; Lin, Hui-Chen
2010-03-01
The aquatic air-breathing fish, Trichogaster microlepis, can be found in fresh water and estuaries. We further evaluated the changes in two important osmoregulatory enzymes, Na(+)/K(+)-ATPase (NKA) and vacuolar-type H(+)-ATPase (VHA), in the gills when fish were subjected to deionized water (DW), fresh water (FW), and salinated brackish water (salinity of 10 g/L). Fish were sampled only 4 days after experimental transfer. The mortality, plasma osmolality, and Na(+) concentration were higher in 10 g/L acclimated fish, while their muscle water content decreased with elevated external salinity. The highest NKA protein abundance was found in the fish gills in 10 g/L, and NKA activity was highest in the DW and 10 g/L acclimated fish. The VHA protein levels were highest in 10 g/L, and VHA activity was highest in the DW treatment. From immunohistochemical results, we found three different cell populations: (1) NKA-immunoreactive (NKA-IR) cells, (2) both NKA-IR and HA-IR cells, and (3) HA-IR cells. NKA-IR cells in the lamellar and interlamellar regions significantly increased in DW and 10 g/L treatments. Only HA-IR cells in the lamellar region were significantly increased in DW. In the interlamellar region, there was no difference in the number of HA-IR cells among the three treated. From these results, T. microlepis exhibited osmoregulatory ability in DW and 10 g/L treatments. The cell types involved in ionic regulation were also examined with immunofluorescence staining; three ionocyte types were found which were similar to the zebrafish model. Copyright 2009 Elsevier B.V. All rights reserved.
Natural and anthropogenic factors affecting freshwater lenses in coastal dunes of the Adriatic coast
NASA Astrophysics Data System (ADS)
Cozzolino, Davide; Greggio, Nicolas; Antonellini, Marco; Giambastiani, Beatrice Maria Sole
2017-08-01
This study characterizes the near-shore portion of the shallow coastal aquifer included in the Ravenna area (Northern Italy) with special attention to the roles of coastal dunes as freshwater reservoirs and their buffer on groundwater salinity. The paper focuses on the presence and evolution of freshwater lenses below coastal dunes and highlights the existing differences between preserved natural dunes and dunes strongly affected by human intervention. The influence that multiple natural and anthropogenic factors, such as land cover, local drainage network, and beach erosion have on the presence, size and evolution of the freshwater lenses in the aquifer is quantified and discussed. The methodology includes multiple seasonal monitoring and sampling campaigns of physical (water level, salinity, and temperature) and chemical (major cations and anions) groundwater parameters. Results indicate that freshwater lenses, where existing, are limited in thickness (about 1-2 m). Proximity to drainage ditches as well as limited dune elevation and size do not allow the formation and permanent storage of large freshwater lenses in the aquifer below the dunes. The pine forest land cover, that replaced the typical bush or sand cover, intensifies evapotranspiration reducing net infiltration and freshwater storage. The cation species distribution in the water shows that a freshening process is ongoing in preserved natural sites with stable or advancing beaches, whereas a salinization process is ongoing in anthropogenic-impacted areas with strongly-fragmented dune systems. Currently, the thin freshwater lenses in the shallow Ravenna coastal aquifer are limited in space and have no relevance for irrigation or any other human activity. The dune-beach system, however, is the recharge zone of the coastal aquifer and its protection is important to reduce water and soil salinization, which in turn control the health of the whole coastal ecosystem.
Methadone patients exhibit increased startle and cortisol response after intravenous yohimbine.
Stine, S M; Grillon, C G; Morgan, C A; Kosten, T R; Charney, D S; Krystal, J H
2001-03-01
Brain noradrenergic systems have been shown to be altered in opioid dependence and to mediate aspects of opioid withdrawal. Pre-clinical and clinical studies by others have shown that yohimbine, which increases noradrenergic activity, also increases both baseline and fear enhancement of the magnitude of the acoustic startle response (ASR). In a separate report from this experiment, it was shown that yohimbine produced opioid withdrawal-like symptoms, including anxiety, in clinically stable methadone-maintained patients and also produced elevations in the norepinepherine (NE) metabolite, 3-methoxy-4 hydroxyphenethyleneglycol (MHPG), and cortisol serum levels. The current study reports the effects of intravenous yohimbine hydrochloride, 0.4 mg/kg versus saline (double-blind), on ASR magnitude, plasma MHPG, and cortisol levels in eight methadone-maintained patients and 13 healthy subjects in a double-blind fashion. Yohimbine increased startle magnitude in both groups. There was no basal (placebo day) difference between the startle response of the two groups, but methadone patients had a larger startle magnitude increase in response to yohimbine than healthy controls. Methadone-maintained patients had lower baseline plasma levels of MHPG and similar baseline plasma cortisol levels compared with normal subjects. Yohimbine caused significant elevation in cortisol and MHPG in both groups. Methadone-maintained subjects had higher elevations in cortisol levels and MHPG (methadone main effect) levels in response to yohimbine. However, when MHPG levels were corrected for baseline differences by analysis of covariance (ANCOVA), the yohimbine effect, but not the methadone effect remained statistically significant. These results are consistent with the previous report and support the hypothesis that abnormalities of the hypothalamic-pituitary-adrenal (HPA) axis and of noradrenergic mechanisms of stress response persist in opioid-agonist maintenance. The ASR effect extends the previous report and provides an additional objective measure for perturbation of noradrenergic and stress responses in these patients.
Ran, Zhaoshou; Li, Shuang; Zhang, Runtao; Xu, Jilin; Liao, Kai; Yu, Xuejun; Zhong, Yingying; Ye, Mengwei; Yu, Shanshan; Ran, Yun; Huang, Wei; Yan, Xiaojun
2017-10-01
Sinonovacula constricta is an economically and nutritionally important bivalve native to the estuaries and mudflats of China, Japan and Korea. In the present study, S. constricta, cultured either under experimental conditions or collected directly from natural coastal areas with different seawater salinities, was investigated for changes in proximates, amino acids and lipids. When culture salinity was increased, levels of moisture, carbohydrate, crude protein and crude lipid were significantly decreased, whereas the level of ash was significantly increased. The level of Ala was increased by 1.5- to 2-fold, whereas the contents of most lipids were significantly decreased, and the proportion of phosphatidylethanolamine was significantly increased. Notably, a high proportion of ceramide aminoethylphosphonates was detected in S. constricta reared at all salinities. The energy content appears to be higher in S. constricta reared at higher salinity. In experimental S. constricta, when the salinity was enhanced, the changes of compositions were very close to those reared at constant high salinity. Sinonovacula constricta reared at higher salinities possesses a superior quality. A short period of exposure to a higher salinity for farmed S. constricta reared at a lower salinity before harvest would be useful with respect to improving its nutritive value. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.
NASA Astrophysics Data System (ADS)
Guimond, J. A.; Yu, X.; Duque, C.; Michael, H. A.
2016-12-01
Salt marshes are a hydrologically complex ecosystem. Tides deliver saline surface water to salt marshes via tidal creeks, and freshwater is introduced through lateral groundwater flow and vertical infiltration from precipitation. Locally, sediment heterogeneity, tides, weather, and topography introduce spatial and temporal complexities in groundwater-surface water interactions, which, in turn, can have a large impact on salt marsh biogeochemistry and the lateral fluxes of nutrients and carbon between the marsh platform and tidal creek. In this study, we investigate spatial patterns of porewater fluorescent dissolved organic matter (fDOM) and redox potential over a spring-neap tidal cycle in a mid-latitude tidal salt marsh in Dover, Delaware. Porewater samplers were used in conjunction with a peristaltic pump and YSI EXO Sonde to measure porewater fDOM, electrical conductivity, redox potential and pH from 0.5, 1.0, 1.5, 2.0, and 2.3 meters deep, as well as surface water from the creek and marsh platform. Eh was also measured continuously every 15 minutes with multi-level in-situ redox sensors at 0, 3, and 5m from the tidal creek, and water level and salinity were measured every 15 minutes continuously in 6 wells equipped with data loggers. Preliminary analyses indicate porewater salinity is dependent on the slope of the marsh platform, the elevation of the sample location, and the distance from a tidal creek. Near-creek redox analyses show tidal oscillations up to 300 mV; redox oscillations in the marsh interior show longer timescale changes. The observed redox oscillations coincide with the water level fluctuations at these locations. Therefore, lateral transport of carbon is determined by both hydrologic flow and biogeochemical processes. Results from this study provide insight into the timescales over which salt marsh hydrology impacts porewater biogeochemistry and the mechanisms controlling regional carbon cycling.
Huckans, Marilyn; Wilhelm, Clare J.; Phillips, Tamara J.; Huang, Elaine T.; Hudson, Rebekah; Loftis, Jennifer M.
2018-01-01
Background Methamphetamine (MA) abuse causes immune dysfunction and neuropsychiatric impairment. The mechanisms underlying these deficits remain unidentified. Methods The effects of MA on anxiety-like behavior and immune function were investigated in mice selectively bred to voluntarily consume high amounts of MA [i.e., MA high drinking (MAHDR) mice]. MA (or saline) was administered to mice using a chronic (14-day), binge-like model. Performance in the elevated zero maze (EZM) was determined 5 days after the last MA dose to examine anxiety-like behavior. Cytokine and chemokine expressions were measured in the hippocampus using quantitative polymerase chain reaction (qPCR). Human studies were also conducted to evaluate symptoms of anxiety using the General Anxiety Disorder-7 Scale in adults with and without a history of MA dependence. Plasma samples collected from human research participants were used for confirmatory analysis of murine qPCR results using an enzyme-linked immunosorbent assay. Results During early remission from MA, MAHDR mice exhibited increased anxiety-like behavior on the EZM and reduced expression of chemokine (C-C motif) ligand 3 (ccl3) in the hippocampus relative to saline-treated mice. Human adults actively dependent on MA and those in early remission had elevated symptoms of anxiety as well as reductions in plasma levels of CCL3, relative to adults with no history of MA abuse. Conclusions The results highlight the complex effects of MA on immune and behavioral function and suggest that alterations in CCL3 signaling may contribute to the mood impairments observed during remission from MA addiction. PMID:29402784
Effect of Nigella sativa (black seeds) against methotrexate-induced nephrotoxicity in mice.
Ahmed, Jawad Hassan; Abdulmajeed, Isra Mohammed
2017-01-01
To evaluate the protective effect of Nigella sativa (NS) against nephrotoxicity of methotrexate (MTX) in mice. Four groups of Swiss albino male mice, eight in each group were used. The study was carried on between October 2014 and April 2015. Group 1 (control) were administered 0.3 ml distilled water orally daily for 21 days and injected with normal saline (0.25 ml) IP weekly. Group 2 (MTX group) were treated with MTX, 10 mg/kg IP weekly, while Group 3 were treated with 0.125 ml of NS oil by mouth daily and injected with normal saline (0.25 ml) IP weekly. Group 4 received 0.125 ml of NS oil by mouth daily and injected with 10 mg/kg MTX IP weekly. Oral treatments were administered using a special curved smooth tip nontraumatic metal needle and IP injections were given for 3 weeks at days 7, 14 and 21. Animals were sacrificed at day 23. Malondialdehyde (MDA) and glutathione (GSH) measurements were performed on kidney homogenate. Histopathology of the kidneys were prepared and examined. MTX has resulted in a small elevation in MDA and reduction in GSH levels in kidney homogenate which was returned back to control values when NS and MTX were administered in combination. Statistical significance was achieved with elevation of GSH by MTX and NS compared to MTX alone. MTX caused histopathological changes suggesting nephrotoxicity in 6 animals out of 8, while no changes were found in all animals treated with MTX and NS. NS is protective against MTX-induced nephrotoxicity.
O'Shaughnessy, D J; Long, R G; Adrian, T E; Christofides, N D; Ghatei, M A; Sarson, D L; Bloom, S R
1985-01-01
Ingestion of a 4,500-kcal mixed meal by healthy volunteers resulted in a significant rise of plasma somatostatin-14-like immunoreactivity (9 +/- 1 pmol l-1. Whether this peptide has a role as a humoral agent or not is still controversial and, until recently, most studies investigating its effects by exogenous administration have produced vastly supraphysiological circulating plasma levels. In order to reproduce the rise obtained following the large meal, synthetic somatostatin-14 was infused at a dose of 0.8 pmol kg-1 min-1 before and during a 530-kcal test breakfast. This resulted in a rise of 8 + 2 pmol l-1 in the peripheral circulation. This infusion produced a significant reduction in the postprandial release of insulin, gastric inhibitory polypeptide, pancreatic polypeptide and in the preprandial motilin levels. In contrast, blood glucose levels following the breakfast were elevated when compared to the control saline infusion. This suggests that somatostatin possesses true endocrine functions and is capable of profoundly altering the postprandial glucose and hormone response.
Heat- and exercise-induced hyperthermia: effects on high-energy phosphates.
Francesconi, R; Mager, M
1979-08-01
To assess the role of high-energy phosphate compounds in the etiology of heat injury with respect to the release of intracellular constituents, the susceptibility of selected tissues to heat injury, and the shock-like demise of the animals, rats were exercised on a treadmill (9.14 m/min) in a hot environment (34.5-35 degrees C) to a rectal temperature (Tre) of 42.5-43 degrees C. In the heart, kidney, left lateral lobe of the liver, and gastrocnemius muscle extricated from animals immediately upon termination of the treadmill run, levels of glucose-6-phosphate (G-6-P), adenosine triphosphate (ATP), and creatine phosphate (CP) were unchanged when compared with sedentary controls. In animals which had been resuscitated by infusion of isotonic saline into a jugular catheter, levels of CP were significantly (p less than 0.025) elevated in gastrocnemius muscle. In rats which were unconscious and succumbing to the effects of hyperthermic injury, levels of hepatic G-6-P and ATP were significantly reduced (p less than 0.05, p less than 0.02, respectively). These results indicate that the combination of exhaustive excercise/heat injury had the most deleterious effects upon hepatic metabolism. However, while resuscitation with physiological saline may be accompanied by an increased synthesis of CP, hyperthermic exhaustion and the concomitant efflux of cellular constituents cannot be attributed to a depletion or even a decrement of high-energy phosphates in vital tissues.
Qingsong, Wang; Yeming, Guan; Xuechun, Liu; Hongjuan, Liu; Jing, Wang
2013-01-01
The mechanism underlying delayed neuropsychological sequelae (DNS) after acute carbon monoxide (CO) poisoning is unclear. There are no effective treatments for DNS. As part of a new generation of antioxidants, edaravone has been reported to improve clinical outcomes in patients exhibiting ischemic strokes. There has been little data about edaravone in relationship to DNS prevention and treatment. We hypothesized that edaravone could ameliorate DNS: Here we test that hypothesis in rabbits Rabbits were randomly divided into sham control,DNS group, saline group and edaravone group. DNS model was made by intraperitoneal injection of CO. Normal saline or edaravone (1 mg/kg, twice daily, a total of one course for 14 days) was infused through the ear vein from Day 15 since the DNS model was established. Serum superoxide dismutase (SOD) activity and malondialdehyde (MDA) were measured in each group. Magnetic resonance spectroscopy (MRS) was used to examine regions of the brain for various compounds. The apoptotic index and neuronal density in the hippocampal CA1 area were also investigated. SOD activity decreased significantly and MDA content increased substantially in the DNS group and saline group when compared with the sham control (p < 0.01). Conversely, in the edaravone group, serum SOD activity significantly increased and MDA levels significantly decreased when compared with DNS and saline group (p < 0.01). In the DNS group, the spectra of H1-MRS showed an elevated Cho/Cr and Lac/Cr ratio, and a marked decrease in the NAA/Cr ratio (p < 0.01). Compared with the saline group and DNS group, the NAA/Cr ratio was significantly increased, and the Cho/Cr and Lac/Cr ratio were significantly decreased in the edaravone group (p < 0.01). The apoptotic index in the edaravone group was significantly lower than that of the DNS and saline groups (p < 0.01, respectively), while the neuronal density in edaravone group was significantly higher than that of the DNS and saline group in the hippocampal CA1 area (p < 0.01, respectively). Our present research demonstrates that edaravone could ameliorate DNS after acute carbon monoxide poisoning in rabbits. These results suggest free radicals could be involved in the underlying mechanisms of DNS. Furthermore, brain MRS shows promise as a tool for early diagnosis for DNS.
NASA Astrophysics Data System (ADS)
Rees, Andrew P.; Hope, Sam B.; Widdicombe, Claire E.; Dixon, Joanna L.; Woodward, E. Malcolm S.; Fitzsimons, Mark F.
2009-03-01
Alkaline phosphatase activity (APA) was determined in bulk particulate material and in a single-cell (ELF) assay at station L4 in the western English Channel during the summer of 2007. Throughout this period, the UK experienced its heaviest summertime rainfall since records began in 1914; with the result that riverine run-off into coastal waters was also elevated relative to long-term averages. Between May and August 2007, three distinct periods of elevated river run-off were observed which resulted in salinity minima at L4 on days 141, 190 and 232. An extended period of high river run-off between days 170 and 210 was responsible for decreases in near-surface salinity at L4 from 35.2068 to a minimum on day 190 of 34.7422. This contributed to the development of haline stratification which supported the development of an intense bloom of the centric diatom Chaetoceros debelis, with maximum observed chlorophyll a concentration of 8.69 μg l -1. Minima in salinity, and maxima in chlorophyll concentration on day 190 were coincident with a peak in river-derived dissolved inorganic nitrogen (DIN) of 1.9 μmol l -1 which was >5 times greater than the summertime mean and 24 times the concentrations experienced at L4 on weeks immediately before and after. There was no accompanying increase in dissolved inorganic phosphorus (DIP), and the DIN:DIP ratio increased to 49. With the inherent phosphorus stress that this caused, rates of APA increased from <4 to 42.4 nmolP l -1 h -1. ELF analysis on day 197 identified two taxa actively expressing alkaline phosphatase: the dinoflagellate Prorocentrum micans and ciliate Tiarana sp.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Yang, Zhaoqing; Wang, Taiping; Voisin, Nathalie
Understanding the response of river flow and estuarine hydrodynamics to climate change, land-use/land-cover change (LULC), and sea-level rise is essential to managing water resources and stress on living organisms under these changing conditions. This paper presents a modeling study using a watershed hydrology model and an estuarine hydrodynamic model, in a one-way coupling, to investigate the estuarine hydrodynamic response to sea-level rise and change in river flow due to the effect of future climate and LULC changes in the Snohomish River estuary, Washington, USA. A set of hydrodynamic variables, including salinity intrusion points, average water depth, and salinity of themore » inundated area, were used to quantify the estuarine response to river flow and sea-level rise. Model results suggest that salinity intrusion points in the Snohomish River estuary and the average salinity of the inundated areas are a nonlinear function of river flow, although the average water depth in the inundated area is approximately linear with river flow. Future climate changes will shift salinity intrusion points further upstream under low flow conditions and further downstream under high flow conditions. In contrast, under the future LULC change scenario, the salinity intrusion point will shift downstream under both low and high flow conditions, compared to present conditions. The model results also suggest that the average water depth in the inundated areas increases linearly with sea-level rise but at a slower rate, and the average salinity in the inundated areas increases linearly with sea-level rise; however, the response of salinity intrusion points in the river to sea-level rise is strongly nonlinear.« less
NASA Astrophysics Data System (ADS)
Renaut, Robin W.; Owen, R. Bernhart; Ego, John K.
2017-05-01
Lake Bogoria, a saline alkaline closed-lake in a drainage basin of Neogene volcanic rocks in the central Kenya Rift, is fed partly by ∼200 hot alkaline springs located in three groups along its margins. Hot springs along the midwest shoreline (Loburu, Chemurkeu) and their travertine deposits have been studied, but little is known about the geothermal activity at southern Lake Bogoria. Observations, field measurements and analyses (geochemical and mineralogical) of the spring waters and deposits, spanning three decades, show that the southern spring waters are more saline, the hydrothermal alteration there is more intense, and that most hot spring deposits are siliceous. Geothermal activity at southern Lake Bogoria (Ng'wasis, Koibobei, Losaramat) includes littoral boiling springs and geysers, with fumaroles at slightly higher elevations. Modern spring deposits are ephemeral sodium carbonates, opal-A crusts and silica gels. Local fossil spring deposits include diatomaceous silica-cemented conglomerates that formed subaqueously when the lake was then dilute and higher than today, and outlying calcite tufa deposits. In contrast, mineral deposits around neighbouring fumarole vents and sites of hydrothermal alteration include clays (kaolinite), sulfate minerals (jarosite, alunite), and Fe-oxyhydroxides linked to rising acidic fluids. When lake level falls, the zone of acidity moves downwards and may overprint older alkaline spring deposits. In contrast, rising lake level leads to lake water dilution and vents in the lower parts of the acidic zone may become dilute alkaline springs. The new evidence at Lake Bogoria shows the potential for using the mineralogy of geothermal sediments to indicate former changes in lake level.
NASA Astrophysics Data System (ADS)
Amoako Johnson, F.; Hutton, C.; Hornby, D.; Lazar, A.; Mukhopadhyay, A.
2014-12-01
Salinity intrusion is a major climate and human induced hazard in coastal deltaic regions resulting in substantial adverse effects on crop production. Impacts are exacerbated by intensified cyclones, sea level rise and storm surges. In this regard, many farmers in the populous Ganges-Brahmaputra Delta of Bangladesh have adopted saline shrimp (Bagda) farming with associated displacement of tenant farmers and potential long term damage to the soil through chemicals used to enhance shrimp production. Despite the impact of salinity intrusion on the environment and the commonly perceived effects of shrimp farming on poverty, there has not been any systematic study that examines the associative relationships between salinisation, shrimp farming and poverty in this delta region. Using the 2011 Bangladesh Population and Housing Census and 2010 LandSat remote sensing data this study examines the spatially explicit impact of salinization as well as saline and freshwater shrimp farming on poverty in the Delta, accounting for important environmental and socio-economic predictors. The findings shows that after accounting for important environmental and socioeconomic predictors, levels and intensities of salinization as well as the extent of saline and freshwater shrimp farming in a union are significantly associated with poverty. The results of the study demonstrate that increases in levels and intensities of salinity increases the probability of a union being in the poorest quintile. As such saline water shrimp farming has the potential to reduce poverty only at high intensities, whilst low levels of freshwater shrimp farming are associated with a reduction in poverty.
Decadal trends in deep ocean salinity and regional effects on steric sea level
NASA Astrophysics Data System (ADS)
Purkey, S. G.; Llovel, W.
2017-12-01
We present deep (below 2000 m) and abyssal (below 4000 m) global ocean salinity trends from the 1990s through the 2010s and assess the role of deep salinity in local and global sea level budgets. Deep salinity trends are assessed using all deep basins with available full-depth, high-quality hydrographic section data that have been occupied two or more times since the 1980s through either the World Ocean Circulation Experiment (WOCE) Hydrographic Program or the Global Ship-Based Hydrographic Investigations Program (GO-SHIP). All salinity data is calibrated to standard seawater and any intercruise offsets applied. While the global mean deep halosteric contribution to sea level rise is close to zero (-0.017 +/- 0.023 mm/yr below 4000 m), there is a large regional variability with the southern deep basins becoming fresher and northern deep basins becoming more saline. This meridional gradient in the deep salinity trend reflects different mechanisms driving the deep salinity variability. The deep Southern Ocean is freshening owing to a recent increased flux of freshwater to the deep ocean. Outside of the Southern Ocean, the deep salinity and temperature changes are tied to isopycnal heave associated with a falling of deep isopycnals in recent decades. Therefore, regions of the ocean with a deep salinity minimum are experiencing both a halosteric contraction with a thermosteric expansion. While the thermosteric expansion is larger in most cases, in some regions the halosteric compensates for as much as 50% of the deep thermal expansion, making a significant contribution to local sea level rise budgets.
Effect of Saline Water Irrigation on Growth and Physiological Responses of Three Rose Rootstocks
Niu, Genhua; Rodriguez, Denise S.; Aguiniga, Lissie
2009-01-01
Salt-tolerant landscape plants are needed for arid and semiarid regions where the supply of quality water is limited and soil salinization often occurs. This study evaluated growth, chloride (Cl) and sodium (Na) uptake, relative chlorophyll content, and chlorophyll fluorescence of three rose rootstocks [Rosa ×fortuniana Lindl., R. multiflora Thunb., and R. odorata (Andr.) Sweet] irrigated with saline solutions at 1.6 (control), 3.0, 6.0, or 9.0 dS·m −1 electrical conductivity in a greenhouse. After 15 weeks, most plants in 9.0 dS·m −1 treatment died regardless of rootstock. Significant growth reduction was observed in all rootstocks at 6.0 dS·m −1 compared with the control and 3.0 dS·m −1, but the reduction in R. ×fortuniana was smaller than in the other two rootstocks. The visual scores of R. multiflora at 3.0 and 6.0 dS·m−1 were slightly lower than those of the other rootstocks. Rosa odorata had the highest shoot Na concentration followed by R. multiflora; however, R. multiflora had the highest root Na concentration followed by R. odorata. All rootstocks had higher Cl accumulation in all plant parts at elevated salinities, and no substantial differences in Cl concentrations in all plant parts existed among the rootstocks, except for leaf Cl concentration in R. multiflora, which was higher than those in the other two rootstocks. The elevated salinities of irrigation water reduced the relative chlorophyll concentration, measured as leaf SPAD readings, and maximal photochemical efficiency of photosystem II (PSII) and minimal fluorescence (F0)/maximum fluorescence (Fv/Fm), but the largest reduction in Fv/Fm was only 2.4%. Based on growth and visual quality, R. ×fortuniana was relatively more salt-tolerant than the other two rootstocks and R. odorata was slightly more salt-tolerant than R. multiflora. PMID:20148186
Early surgical suction and washout for treatment of cytotoxic drug extravasations.
Vandeweyer, E; Deraemaecker, R
2000-02-01
This case report is presented to assess safety and efficiency of early suction and saline washout of extravasated cytotoxic drugs. Through multiple small skin incisions, the area of extravasation is first suctioned and subsequently extensively washed out with saline. Incisions are left open and the arm is elevated for 24 hours. A complete healing was obtained in five days without any skin or soft tissue loss. No additional treatment was needed. Early referral and surgical treatment by suction and washout is a safe and reliable treatment protocol for major cytotoxic drug extravasation injuries.
Harmane induces anxiolysis and antidepressant-like effects in rats.
Aricioglu, Feyza; Altunbas, Hale
2003-12-01
A forced swim test (FST) and an elevated plus maze (EPM) were used to determine antidepressant and anxiolytic effects of harmane in rats in comparison with a known antidepressant, imipramine (30 mg/kg i.p.). Harmane (2.5, 5.0, or 10 mg/kg, i.p.), saline, or imipramine were given 30 minutes before the tests. Administration of harmane decreased the time of immobility in the FST dose-dependently and increased the time spent in open arms in the EPM, as compared with the saline group. As an endogenous substance, harmane therefore has anti-anxiety and antidepressant effects.
Maršálová, Lucie; Vítámvás, Pavel; Hynek, Radovan; Prášil, Ilja T.; Kosová, Klára
2016-01-01
Response to a high salinity treatment of 300 mM NaCl was studied in a cultivated barley Hordeum vulgare Syrian cultivar Tadmor and in a halophytic wild barley H. marinum. Differential salinity tolerance of H. marinum and H. vulgare is underlied by qualitative and quantitative differences in proteins involved in a variety of biological processes. The major aim was to identify proteins underlying differential salinity tolerance between the two barley species. Analyses of plant water content, osmotic potential and accumulation of proline and dehydrin proteins under high salinity revealed a relatively higher water saturation deficit in H. marinum than in H. vulgare while H. vulgare had lower osmotic potential corresponding with high levels of proline and dehydrins. Analysis of proteins soluble upon boiling isolated from control and salt-treated crown tissues revealed similarities as well as differences between H. marinum and H. vulgare. The similar salinity responses of both barley species lie in enhanced levels of stress-protective proteins such as defense-related proteins from late-embryogenesis abundant family, several chaperones from heat shock protein family, and others such as GrpE. However, there have also been found significant differences between H. marinum and H. vulgare salinity response indicating an active stress acclimation in H. marinum while stress damage in H. vulgare. An active acclimation to high salinity in H. marinum is underlined by enhanced levels of several stress-responsive transcription factors from basic leucine zipper and nascent polypeptide-associated complex families. In salt-treated H. marinum, enhanced levels of proteins involved in energy metabolism such as glycolysis, ATP metabolism, and photosynthesis-related proteins indicate an active acclimation to enhanced energy requirements during an establishment of novel plant homeostasis. In contrast, changes at proteome level in salt-treated H. vulgare indicate plant tissue damage as revealed by enhanced levels of proteins involved in proteasome-dependent protein degradation and proteins related to apoptosis. The results of proteomic analysis clearly indicate differential responses to high salinity and provide more profound insight into biological mechanisms underlying salinity response between two barley species with contrasting salinity tolerance. PMID:27536311
78 FR 19217 - Endangered Species; File No. 16547-01
Federal Register 2010, 2011, 2012, 2013, 2014
2013-03-29
... below 22 parts per thousand salinity. Researchers are currently authorized to capture adult, juvenile... telemetry tags dependent on the life stage (adult, sub-adult and juvenile) and the salinity level where... salinity level in the waters of Virginia and Maryland. All previous activities are authorized; however, the...
Ji, Jiantao; Peng, Yongzhen; Wang, Bo; Mai, Wenke; Li, Xiyao; Zhang, Qiong; Wang, Shuying
2018-05-31
High inorganic salts inevitably impose a toxic impact on biological treatment processes. In this study, the effect of salinity on the performance and microbial community structures of partial-denitrification (PD) was firstly investigated. Results showed the denitrifying activities of non-domesticated PD sludge were completely inhibited under a temporary high salinity (≥1.5 wt%). However, after domestication, denitrifying activities maintained above 50% of the maximum with salinity build-up step-by-step from 0.0 wt% to 3.0 wt%. High nitrite production was stably achieved during 120 days with nitrate-to-nitrite transformation ratio around 90%. Further investigation showed extracellular polymeric substances content of PD sludge increased from 184.59 mg gVSS -1 to 560.64 mg gVSS -1 , accompanied by the elevation of average particle size. This occurred against high salinity as a protective response of PD bacteria. Moreover, Thauera, the functional bacteria of PD system, was still dominant with the relative abundance increasing to 83.36% (3.0 wt%) from 51.33% (0.0 wt%). Copyright © 2018 Elsevier Ltd. All rights reserved.
Sanabria, Eduardo; Quiroga, Lorena; Vergara, Cristina; Banchig, Mariana; Rodriguez, Cesar; Ontivero, Emanuel
2018-05-01
Rhinella spinulosa is distributed from Peru to Argentina (from 1200 to 5000 m elevation), inhabiting arid mountain valleys of the Andes, characterized by salty soils. The variations in soil salinity, caused by high evapotranspiration of water, can create an osmotic constraint and high thermal oscillations for metamorphsed Andean toad (R. spinulosa), affecting their thermoregulation and extreme thermal tolerances. We investigated the changes in thermal tolerance parameters (critical thermal maximum and crystallization temperature) of a population of metamorphosed R. spinulosa from the Monte Desert of San Juan, Argentina, under different substrate salinity conditions. Our results suggest that the locomotor performance of metamorphs of R. spinulosa is affected by increasing salinity concentrations in the environment where they develop. On the other hand, the thermal extremes of metamorphs of R. spinulosa also showed changes associated with different salinity conditions. According to other studies on different organisms, the increase of the osmolarity of the internal medium may increase the thermal tolerance of this species. More studies are needed to understand the thermo-osmolar adjustments of the metamorphs of toads to environmental variability. Copyright © 2018 Elsevier Ltd. All rights reserved.
Pattanashetti, Laxmi Adiveppa; Taranalli, Ashok D; Parvatrao, Vinay; Malabade, Rohit H; Kumar, Dushyant
2017-01-01
The objective of this study was to evaluate the neuroprotective effect of quercetin with donepezil in scopolamine-induced amnesia in rats. Five groups of adult male Wistar rats (12 months old) weighing 180-200 g ( n = 6) were used. The normal control group received normal saline and test group animals were pretreated orally with quercetin (25 mg/kg), donepezil (3 mg/kg), and a combination of quercetin (25 mg/kg) with donepezil (3 mg/kg), respectively, dosed at every 24 h interval for 14 consecutive days, afterward amnesia was induced by scopolamine (3 mg/kg) on the 14 th day through intraperitoneal route. Cognitive performance was assessed by the Morris water maze, elevated plus maze, and passive avoidance paradigm. Acetylcholinesterase enzyme (AchE) level, biochemical markers such as lipid peroxidase (LPO), glutathione (GSH), β amyloid 1-42 level, and histopathological study of rat brain were estimated. Statistical analysis was done by one-way analysis of variance, followed by Dunnett's post hoc test. P ≥ 0.05 was considered statistically significant. Pretreatment with quercetin, donepezil, and their combination showed a significant increase in escape latency, step-through latency, and decreased transfer latency in respective cognitive models of the Morris water maze, passive avoidance test, and elevated plus maze. Further coadministration significantly decreased AchE level, β amyloid 1-42 level as compared to individual therapy. Biochemical markers such as elevated GSH, decreased LPO were observed, and histopathological studies revealed the reversal of neuronal damage in the treatment group ( P < 0.05) as compared to scopolamine-treated control group. Pretreatment with quercetin potentiates the action of donepezil in scopolamine-induced amnesia in rats. The improved cognitive memory could be due to the synergistic effect of the drugs by decreasing AchE level, β amyloid 1-42 level, and antioxidant action in rat brain.
Pattanashetti, Laxmi Adiveppa; Taranalli, Ashok D.; Parvatrao, Vinay; Malabade, Rohit H.; Kumar, Dushyant
2017-01-01
Objective: The objective of this study was to evaluate the neuroprotective effect of quercetin with donepezil in scopolamine-induced amnesia in rats. Materials and Methods: Five groups of adult male Wistar rats (12 months old) weighing 180–200 g (n = 6) were used. The normal control group received normal saline and test group animals were pretreated orally with quercetin (25 mg/kg), donepezil (3 mg/kg), and a combination of quercetin (25 mg/kg) with donepezil (3 mg/kg), respectively, dosed at every 24 h interval for 14 consecutive days, afterward amnesia was induced by scopolamine (3 mg/kg) on the 14th day through intraperitoneal route. Cognitive performance was assessed by the Morris water maze, elevated plus maze, and passive avoidance paradigm. Acetylcholinesterase enzyme (AchE) level, biochemical markers such as lipid peroxidase (LPO), glutathione (GSH), β amyloid1-42level, and histopathological study of rat brain were estimated. Statistical analysis was done by one-way analysis of variance, followed by Dunnett's post hoc test. P ≥ 0.05 was considered statistically significant. Results: Pretreatment with quercetin, donepezil, and their combination showed a significant increase in escape latency, step-through latency, and decreased transfer latency in respective cognitive models of the Morris water maze, passive avoidance test, and elevated plus maze. Further coadministration significantly decreased AchE level, β amyloid1-42level as compared to individual therapy. Biochemical markers such as elevated GSH, decreased LPO were observed, and histopathological studies revealed the reversal of neuronal damage in the treatment group (P < 0.05) as compared to scopolamine-treated control group. Conclusion: Pretreatment with quercetin potentiates the action of donepezil in scopolamine-induced amnesia in rats. The improved cognitive memory could be due to the synergistic effect of the drugs by decreasing AchE level, β amyloid1-42level, and antioxidant action in rat brain. PMID:28458424
Shekhar, A; Sims, L S; Bowsher, R R
1993-11-05
In the previous report, we had shown that blockade and enhancement of GABAA receptors in the DMH of rats increased or decreased the level of anxiety, respectively, as measured by the elevated plus-maze test. The present study was conducted to assess the effects of enhancing GABAA neurotransmission in the DMH of rats on the physiological concomitants of anxiety such as increases in heart rate (HR), blood pressure (BP) and plasma norepinephrine (NE) levels while the animals were placed on the elevated plus-maze. Male Sprague-Dawley rats were equipped with arterial and venous catheters and stereotaxically implanted with microinjection cannulae in the cardiostimulatory region of the DMH where injection of bicuculline methiodide (BMI) elicited increases in heart rate under anesthesia. After recovery, rats were injected with either saline or the GABAA agonist muscimol and their HR, BP and plasma NE responses were measured when confined in the open or the closed arm of the elevated plus-maze. Injection of muscimol into the DMH reduced the increases seen in HR, BP and plasma NE when the rats were confined to either the closed or the open arms in addition to decreasing 'anxiety' in the plus-maze. Injection of muscimol into the areas of the hypothalamus surrounding the DMH did not significantly affect the changes in HR, BP and plasma NE in the plus-maze. Blocking the changes in HR and BP elicited by microinjecting GABAergic drugs into the DMH of rats, with systemic injections of a combination of atropine and the beta-blocker atenolol, did not block the behavioral effects of the GABAergic drugs in the plus-maze test.
Ivanina, Anna V; Beniash, Elia; Etzkorn, Markus; Meyers, Tiffany B; Ringwood, Amy H; Sokolova, Inna M
2013-09-15
Estuarine and coastal habitats experience large fluctuations of environmental factors such as temperature, salinity, partial pressure of CO2 ( [Formula: see text] ) and pH; they also serve as the natural sinks for trace metals. Benthic filter-feeding organisms such as bivalves are exposed to the elevated concentrations of metals in estuarine water and sediments that can strongly affect their physiology. The effects of metals on estuarine organisms may be exacerbated by other environmental factors. Thus, a decrease in pH caused by high [Formula: see text] (hypercapnia) can modulate the effects of trace metals by affecting metal bioavailability, accumulation or binding. To better understand the cellular mechanisms of interactions between [Formula: see text] and trace metals in marine bivalves, we exposed isolated mantle cells of the hard clams (Mercenaria mercenaria) to different levels of [Formula: see text] (0.05, 1.52 and 3.01 kPa) and two major trace metal pollutants - cadmium (Cd) and copper (Cu). Elevated [Formula: see text] resulted in a decrease in intracellular pH (pHi) of the isolated mantle cells from 7.8 to 7.4. Elevated [Formula: see text] significantly but differently affected the trace metal accumulation by the cells. Cd uptake was suppressed at elevated [Formula: see text] levels while Cu accumulation has greatly accelerated under hypercapnic conditions. Interestingly, at higher extracellular Cd levels, labile intracellular Cd(2+) concentration remained the same, while intracellular levels of free Zn(2+) increased suggesting that Cd(2+) substitutes bound Zn(2+) in these cells. In contrast, Cu exposure did not affect intracellular Zn(2+) but led to a profound increase in the intracellular levels of labile Cu(2+) and Fe(2+). An increase in the extracellular concentrations of Cd and Cu led to the elevated production of reactive oxygen species under the normocapnic conditions (0.05 kPa [Formula: see text] ); surprisingly, this effect was mitigated in hypercapnia (1.52 and 3.01 kPa). Overall, our data reveal complex and metal-specific interactions between the cellular effects of trace metals and [Formula: see text] in clams and indicate that variations in environmental [Formula: see text] may modulate the biological effects of trace metals in marine organisms. Copyright © 2013 Elsevier B.V. All rights reserved.
Productivity and food value of Amaranthus cruentus under non-lethal salt stress
NASA Astrophysics Data System (ADS)
Macler, Bruce A.; MacElroy, Robert D.
Stress effects from the accumulation of metal salts may pose a problem for plants in closed biological systems such as spacecraft. This work examined the effects of salinity on growth, photosynthesis and carbon allocation in the crop plant, Amaranthus. Plants were germinated and grown in modified Hoagland's solution with NaCl concentrations of 0 to 1.0%. Plants received salt treatments at various times in development to assess effects on particular life history phases. For Amaranthus cruentus, germination, vegetative growth, flowering, seed development and yield were normal at salinities from 0 to 0.2%. Inhibition of these phases increased from 0.2 to 0.4% salinity and was total above 0.5%. 1.0% salinity was lethal to all developmental phases. Onset of growth phases were not affected by salinity. Plants could not be adapted by gradually increasing salinity over days or weeks. Water uptake increased, while photosynthetic CO2 uptake decreased with increasing salinity on a dry weight basis during vegetative growth. Respiration was not affected by salinity. After flowering, respiration and photosynthesis decreased markedly, such that 1.0% NaCl inhibited photosynthesis completely. Protein levels were unchanged with increasing salinity. Leaf starch levels were lower at salinities of 0.5% and above, while stem starch levels were not affected by these salinities. The evidence supports salt inhibition arising from changes in primary biochemical processes rather than from effects on water relations. While not addressing the toxic effects of specific ions, it suggests that moderate salinity per se need not be a problem in space systems.
Ebrahimi, Loghman; Saboory, Ehsan; Roshan-Milani, Shiva; Hashemi, Paria
2014-09-01
Prenatal exposure to stress and morphine has complicated effects on epileptic seizure. Many reports have shown an interaction between morphine- and stress-induced behavioral changes in adult rats. In the present study, effect of prenatal forced-swim stress and morphine co-administration on pentylentetrazole (PTZ)-induced epileptic behaviors was investigated in rat offspring to address effect of the interaction between morphine and stress. Pregnant rats were divided to four groups of control-saline, control-morphine, stressed-saline and stressed-morphine. In the stressed group, the rats were placed in 25 °C water on 17-19 days of pregnancy. In the morphine/saline group, the rats received morphine/saline on the same days. In the morphine/saline-stressed group, they were exposed to stress and received morphine/saline simultaneously. On postnatal day 15 (P15), blood samples were collected to determine corticosterone (COS) level. On P15 and P25, PTZ was injected to the rest of pups to induce seizure. Then, epileptic behaviors of each rat were individually observed. Latency of tonic-colonic seizures decreased in control-morphine and stressed-saline groups while increasing in stressed-morphine rats compared to control-saline group on P15. Duration of tonic-colonic seizures significantly increased in control-morphine and stressed-saline rats compared to stressed-morphine and control-saline rats on P15, but not P25. COS levels increased in stressed-saline group but decreased in control-morphine group compared to control-saline rats. Body weight was significantly higher in morphine groups than saline treated rats. Prenatal exposure to forced-swim stress potentiated PTZ-induced seizure in the offspring rats. Co-administration of morphine attenuated effect of stress on body weight, COS levels, and epileptic behaviors. © 2014 Wiley Periodicals, Inc.
USDA-ARS?s Scientific Manuscript database
Salinity is a major cause of abiotic stress in arid and semi-arid climates that substantially reduces crop yield. This study evaluated the effects of salinity on germination and early seedling growth of two carrot cultivars in vitro under varying salinity levels. Salinity was induced by incorporatin...
Huff, G.F.
2004-01-01
Increasing demand on the limited supplies of freshwater in the desert Southwest, as well as other parts of the United States, has increased the level of interest in saline-water resources. Saline ground water has long been recognized as a potentially important contributor to water supply in the Southwest, as demonstrated by the number of hydrologic, geologic, and engineering studies on the distribution of saline water and the feasibility of desalination. Potential future study needs include investigating and documenting the three-dimensional distribution of salinity and chemical composition of saline-water resources and the hydraulic properties of aquifers containing these saline-water resources, assessing the chemical suitability of saline water for use with existing and anticipated desalination technologies, simulating the effect of withdrawal of saline ground water on water levels and water composition in saline and adjoining or overlying freshwater aquifers, and determining the suitability of target geologic formations for injection of desalination-generated waste.
De Novo Transcriptional Analysis of Alfalfa in Response to Saline-Alkaline Stress.
An, Yi-Min; Song, Li-Li; Liu, Ying-Rui; Shu, Yong-Jun; Guo, Chang-Hong
2016-01-01
Saline-alkaline stress, caused by high levels of harmful carbonate salts and high soil pH, is a major abiotic stress that affects crop productivity. Alfalfa is a widely cultivated perennial forage legume with some tolerance to biotic and abiotic stresses, especially to saline-alkaline stress. To elucidate the mechanism underlying plant saline-alkaline tolerance, we conducted transcriptome analysis of whole alfalfa seedlings treated with saline-alkaline solutions for 0 day (control), 1 day (short-term treatment), and 7 days (long-term treatment) using ion torrent sequencing technology. A transcriptome database dataset of 53,853 unigenes was generated, and 2,286 and 2,233 genes were differentially expressed in the short-term and long-term treatment, respectively. Gene ontology analysis revealed 14 highly enriched pathways and demonstrated the differential response of metabolic pathways between the short-term and long-term treatment. The expression levels of 109 and 96 transcription factors were significantly altered significantly after 1 day and 7 days of treatment, respectively. Specific responses of peroxidase, flavonoids, and the light pathway component indicated that the antioxidant capacity was one of the central mechanisms of saline-alkaline stress tolerance response in alfalfa. Among the 18 differentially expressed genes examined by real time PCR, the expression levels of eight genes, including inositol transporter, DNA binding protein, raffinose synthase, ferritin, aldo/keto reductase, glutathione S-transferase, xyloglucan endotrans glucosylase, and a NAC transcription factor, exhibited different patterns in response to saline and alkaline stress. The expression levels of the NAC transcription factor and glutathione S-transferase were altered significantly under saline stress and saline-alkaline stress; they were upregulated under saline-alkaline stress and downregulated under salt stress. Physiology assays showed an increased concentration of reactive oxygen species and malondialdehyde and a decreased content of chlorophyll, indicating that anti-oxidation and detoxification play an important role in response to saline-alkaline stress. Overall, the transcriptome analysis provided novel insights into the saline-alkaline stress tolerance response mechanisms in alfalfa.
De Novo Transcriptional Analysis of Alfalfa in Response to Saline-Alkaline Stress
An, Yi-Min; Song, Li-Li; Liu, Ying-Rui; Shu, Yong-Jun; Guo, Chang-Hong
2016-01-01
Saline-alkaline stress, caused by high levels of harmful carbonate salts and high soil pH, is a major abiotic stress that affects crop productivity. Alfalfa is a widely cultivated perennial forage legume with some tolerance to biotic and abiotic stresses, especially to saline-alkaline stress. To elucidate the mechanism underlying plant saline-alkaline tolerance, we conducted transcriptome analysis of whole alfalfa seedlings treated with saline-alkaline solutions for 0 day (control), 1 day (short-term treatment), and 7 days (long-term treatment) using ion torrent sequencing technology. A transcriptome database dataset of 53,853 unigenes was generated, and 2,286 and 2,233 genes were differentially expressed in the short-term and long-term treatment, respectively. Gene ontology analysis revealed 14 highly enriched pathways and demonstrated the differential response of metabolic pathways between the short-term and long-term treatment. The expression levels of 109 and 96 transcription factors were significantly altered significantly after 1 day and 7 days of treatment, respectively. Specific responses of peroxidase, flavonoids, and the light pathway component indicated that the antioxidant capacity was one of the central mechanisms of saline-alkaline stress tolerance response in alfalfa. Among the 18 differentially expressed genes examined by real time PCR, the expression levels of eight genes, including inositol transporter, DNA binding protein, raffinose synthase, ferritin, aldo/keto reductase, glutathione S-transferase, xyloglucan endotrans glucosylase, and a NAC transcription factor, exhibited different patterns in response to saline and alkaline stress. The expression levels of the NAC transcription factor and glutathione S-transferase were altered significantly under saline stress and saline-alkaline stress; they were upregulated under saline-alkaline stress and downregulated under salt stress. Physiology assays showed an increased concentration of reactive oxygen species and malondialdehyde and a decreased content of chlorophyll, indicating that anti-oxidation and detoxification play an important role in response to saline-alkaline stress. Overall, the transcriptome analysis provided novel insights into the saline-alkaline stress tolerance response mechanisms in alfalfa. PMID:27458463
Surface-water salinity in the Gunnison River Basin, Colorado, water years 1989 through 2007
Schaffrath, Keelin R.
2012-01-01
Elevated levels of dissolved solids in water (salinity) can result in numerous and costly issues for agricultural, industrial, and municipal water users. The Colorado River Basin Salinity Control Act of 1974 (Public Law 93-320) authorized planning and construction of salinity-control projects in the Colorado River Basin. One of the first projects was the Lower Gunnison Unit, a project to mitigate salinity in the Lower Gunnison and Uncompahgre River Basins. In cooperation with the Bureau of Reclamation (USBR), the U.S. Geological Survey conducted a study to quantify changes in salinity in the Gunnison River Basin. Trends in salinity concentration and load during the period water years (WY) 1989 through 2004 (1989-2004) were determined for 15 selected streamflow-gaging stations in the Gunnison River Basin. Additionally, trends in salinity concentration and load during the period WY1989 through 2007 (1989-2007) were determined for 5 of the 15 sites for which sufficient data were available. Trend results also were used to identify regions in the Lower Gunnison River Basin (downstream from the Gunnison Tunnel) where the largest changes in salinity loads occur. Additional sources of salinity, including residential development (urbanization), changes in land cover, and natural sources, were estimated within the context of the trend results. The trend results and salinity loads estimated from trends testing also were compared to USBR and Natural Resources Conservation Service (NRCS) estimates of off-farm and on-farm salinity reduction from salinity-control projects in the basin. Finally, salinity from six additional sites in basins that are not affected by irrigated agriculture or urbanization was monitored from WY 2008 to 2010 to quantify what portion of salinity may be from nonagricultural or natural sources. In the Upper Gunnison area, which refers to Gunnison River Basin above the site located on the Gunnison River below the Gunnison Tunnel, estimated mean annual salinity load was 110,000 tons during WY 1989-2004. Analysis of both study periods (WY 1989-2004 and WY 1989-2007) showed an initial decrease in salinity load with a minimum in 1997. The net change over either study period was only significant during WY 1989-2007. Salinity load significantly decreased at the Gunnison River near Delta by 179,000 tons during WY 1989-2004. Just downstream, the Uncompahgre River enters the Gunnison River where there also was a highly significant decrease in salinity load of 55,500 tons. The site that is located at the mouth of the study area is the Gunnison River near Grand Junction where the decrease was the largest. Salinity loads decreased by 247,000 tons during WY 1989-2004 at this site though the decrease attenuated by 2007 and the net change was a decrease of 207,000 tons. The trend results presented in this study indicate that the effect of urbanization on salinity loads is difficult to discern from the effects of irrigated agriculture and that natural sources contribute a fraction of the total salinity load for the entire basin. Based on the calculated yields and geology, 23-63 percent of the estimated annual salinity load was from natural sources at the Gunnison River near Grand Junction during WY 1989-2007. The largest changes in salinity load occurred at the Gunnison River near Grand Junction as well as the two sites located in Delta: the Gunnison River at Delta and the Uncompahgre River at Delta. Those three sites, especially the two sites at Delta, were the most affected by irrigated agriculture, which was observed in the estimated mean annual loads. Irrigated acreage, especially acreage underlain by Mancos Shale, is the target of salinity-control projects intended to decrease salinity loads. The NRCS and the USBR have done the majority of salinity control work in the Lower Gunnison area of the Gunnison River Basin, and the focus has been in the Uncompahgre River Basin and in portions of the Lower Gunnison River Basin (downstream from the Gunnison Tunnel). According to the estimates from the USBR and NRCS, salinity-control projects may be responsible for a reduction of 117,300 tons of salinity as of 2004 and 142,000 tons as of 2007 at the Gunnison River near Grand Junction, Colo. (streamflow-gaging station 09152500). USBR and NRCS estimates account for all but 130,000 tons in 2004 and 65,000 tons in 2007 of salinity load reduction. The additional reduction could be a reduction in natural salt loading to the streams because of land-cover changes during the study period. It is possible also that the USBR and NRCS have underestimated changes in salinity loads as a result of the implementation of salinity-control projects.
Park, Jungmin; Kim, Youn-Sung; Kim, Sang-Gyu; Jung, Jae-Hoon; Woo, Je-Chang; Park, Chung-Mo
2011-01-01
Seed germination is regulated through elaborately interacting signaling networks that integrate diverse environmental cues into hormonal signaling pathways. Roles of gibberellic acid and abscisic acid in germination have been studied extensively using Arabidopsis (Arabidopsis thaliana) mutants having alterations in seed germination. Auxin has also been implicated in seed germination. However, how auxin influences germination is largely unknown. Here, we demonstrate that auxin is linked via the IAA30 gene with a salt signaling cascade mediated by the NAM-ATAF1/2-CUC2 transcription factor NTM2/Arabidopsis NAC domain-containing protein 69 (for NAC with Transmembrane Motif1) during seed germination. Germination of the NTM2-deficient ntm2-1 mutant seeds exhibited enhanced resistance to high salinity. However, the salt resistance disappeared in the ntm2-1 mutant overexpressing the IAA30 gene, which was induced by salt in a NTM2-dependent manner. Auxin exhibited no discernible effects on germination under normal growth conditions. Under high salinity, however, whereas exogenous application of auxin further suppressed the germination of control seeds, the auxin effects were reduced in the ntm2-1 mutant. Consistent with the inhibitory effects of auxin on germination, germination of YUCCA 3-overexpressing plants containing elevated levels of active auxin was more severely influenced by salt. These observations indicate that auxin delays seed germination under high salinity through cross talk with the NTM2-mediated salt signaling in Arabidopsis. PMID:21450938
Koyama, Hiroki; Mizusawa, Nanami; Hoashi, Masataka; Tan, Engkong; Yasumoto, Ko; Jimbo, Mitsuru; Ikeda, Daisuke; Yokoyama, Takehiko; Asakawa, Shuichi; Piyapattanakorn, Sanit; Watabe, Shugo
2018-06-05
Shrimps inhabiting coastal waters can survive in a wide range of salinity. However, the molecular mechanisms involved in their acclimation to different environmental salinities have remained largely unknown. In the present study, we acclimated kuruma shrimp ( Marsupenaeus japonicus ) at 1.7%, 3.4% and 4.0% salinities. After acclimating for 6, 12, 24 and 72 h, we determined free amino acid concentrations in their abdominal muscle, and performed RNA sequencing analysis on this muscle. The concentrations of free amino acids were clearly altered depending on salinity after 24 h of acclimation. Glutamine and alanine concentrations were markedly increased following the increase of salinity. In association with such changes, many genes related to amino acid metabolism changed their expression levels. In particular, the increase of the expression level of the gene encoding glutamate-ammonia ligase, which functions in glutamine metabolism, appeared to be associated with the increased glutamine concentration at high salinity. Furthermore, the increased alanine concentration at high salinity was likely associated with the decrease in the expression levels of the the gene encoding alanine-glyoxylate transaminase. Thus, there is a possibility that changes in the concentration of free amino acids for osmoregulation in kuruma shrimp are regulated by changes in the expression levels of genes related to amino acid metabolism. © 2018. Published by The Company of Biologists Ltd.
Hoseinifar, Seyed Hossein; Roosta, Zahra; Hajimoradloo, Abdolmajid; Vakili, Farzaneh
2015-02-01
The present study evaluates the effects of different levels of dietary Lactobacillus acidophilus as feed supplement on intestinal microbiota, skin mucus immune parameters and salinity stress resistance as well as growth performance of black swordtail (Xiphophorus helleri). One-thousand and eight hundred healthy black swordtail larvae (0.03 ± 0.001 g) were randomly distributed in 12 tanks (100 L) at a density of 150 fish per aquaria and fed different levels of dietary L. acidophilus (0, 1.5 × 10(8), 3 × 10(8) and 6 × 10(8) CFU g(-1)) for 10 weeks. At the end of trial, there were significant differences among antibacterial activity of skin mucus in probiotic fed fish and control group (P < 0.05). Furthermore, the skin mucus protein level and alkaline phosphatase activity in control group were significantly lower than those of L. acidophilus fed fish (P < 0.05). Microbiological assessments revealed that feeding with probiotic supplemented diet remarkably increased total autochthonous bacteria and autochthonous lactic acid bacteria levels (P < 0.05). The results showed that dietary administration of L. acidophilus significantly elevated black swordtail resistance against salinity stress (i.e survival %) (P < 0.05). Also, dietary administration of different levels of L. acidophilus improved weight gain, SGR, FCR compared to fish fed unsupplemented diet (P < 0.05). These results demonstrate beneficial effects of dietary L. acidophilus on mucosal immune parameters, intestinal microbiota, stress resistance and growth parameters of black swordtail and the appropriate inclusion is 6 × 10(8) CFU g(-1). Copyright © 2014 Elsevier Ltd. All rights reserved.
Sustainable use of groundwater in Atoll Islands
NASA Astrophysics Data System (ADS)
Taniguchi, M.; Nakada, S.; Umezawa, Y.; Yamano, H.
2010-12-01
Water resources in small islands, such as atoll islands, are limited and threatened by climate change such as changes in precipitation and sea level rise. Groundwater is the main water resources in many atoll islands, and the freshwater in aquifers in coral atolls, where the average elevations are a few meters above the sea level, exists as lenses f1oating on salt water. Decrease in precipitation and groundwater recharge is caused by the climate change, increases of storm surge, and excessive groundwater extractions due to over population. There is high possibility that the aquifer salinization can damage the important natural ambience for the people living habitat such as crops field and vegetation. In this study, the aquifer salinization is evaluated by using electrical resistivity, hydrological and long-term meteorological data in two low-lying coral atolls, Laura islet, Majuro Atoll, Marshall islands and Fongafale islet, Funafuti atoll, Tuvalu. Hydrological surveys conducted in Laura islet showed that the interface between seawater and freshwater is shallowed in Aug 2009. This may be attributed to the result of recent decrease of the decadal rainfall and/or the sea level rise. The detailed structure of the freshwater lens based on the electrical resistivity surveys showed patches of brackish water due to the intrusion of seawater and over-pumping. The clear intrusion of the saltwater was observed near the lagoon coast which might be inf1uenced by the recirculation of the seawater in the margin of the freshwater lens. The recirculation was confirmed based on the analysis of the submarine groundwater discharge (SGD) observed by seepage meters. On the other hand, in Fongatale islet, the geoelectric and hydrological surveys conducted in March 2009 showed that the soil and groundwater salinization was mainly caused by the tidal forcing during spring tides. The decrease of the resistivity during the f1ood tide indicates the coastal aquifer beneath the islet is intruded by the saline or brackish pore water in phase with the semi-diurnal tide. The aquifer allowing the intrusion can be formed by gravel retaining high porosity due to the past reclamation. Analyses of water balance in atoll islands including groundwater, water tanks and water pools, have been made and shown as the strategies for sustainable use of groundwater based on three different targeted periods.
Cook, Jason B; Nelli, Stephanie M; Neighbors, Mackenzie R; Morrow, Danielle H; O'Buckley, Todd K; Maldonado-Devincci, Antoniette M; Morrow, A Leslie
2014-01-01
The neuroactive steroid (3α,5α)-3-hydroxypregnan-20-one (3α,5α-THP or allopregnanolone) is a positive modulator of GABAA receptors synthesized in the brain, adrenal glands, and gonads. In rats, ethanol activates the hypothalamic–pituitary–adrenal axis and elevates 3α,5α-THP in plasma, cerebral cortex, and hippocampus. In vivo, these effects are dependent on both the pituitary and adrenal glands. In vitro, however, ethanol locally increases 3α,5α-THP in hippocampal slices, in the absence of adrenal influence. Therefore, it is not known whether ethanol can change local brain levels of 3α,5α-THP in vivo, independent of the adrenals. To directly address this controversy, we administered ethanol (2 g/kg) or saline to rats that underwent adrenalectomy (ADX) or received sham surgery and performed immunohistochemistry for 3α,5α-THP. In the medial prefrontal cortex (mPFC), ethanol increased 3α,5α-THP after sham surgery, compared with saline controls, with no ethanol-induced change in 3α,5α-THP following ADX. In subcortical regions, 3α,5α-THP was increased independent of adrenals in the CA1 pyramidal cell layer, dentate gyrus polymorphic layer, bed nucleus of the stria terminalis, and paraventricular nucleus of the hypothalamus. Furthermore, ethanol decreased 3α,5α-THP labeling in the nucleus accumbens shore and central nucleus of the amygdala, independent of the adrenal glands. These data indicate that ethanol dynamically regulates local 3α,5α-THP levels in several subcortical regions; however, the adrenal glands contribute to 3α,5α-THP elevations in the mPFC. Using double immunofluorescent labeling we determined that adrenal dependence of 3α,5α-THP induction by ethanol is not due to a lack of colocalization of 3α,5α-THP with the cholesterol transporters steroidogenic acute regulatory protein (StAR) or translocator protein (TSPO). PMID:24566803
Patterns of intraocular pressure elevation after aqueous humor outflow obstruction in rats.
Jia, L; Cepurna, W O; Johnson, E C; Morrison, J C
2000-05-01
To determine the diural intraocular pressure (IOP) response of Brown Norway rat eyes after sclerosis of the aqueous humor outflow pathways and its relationship to optic nerve damage. Hypertonic saline was injected into a single episcleral vein in 17 animals and awake IOP measured in both the light and dark phases of the circadian cycle for 34 days. Mean IOP for light and dark phases during the experimental period were compared with the respective pressures of the uninjected fellow eyes. Optic nerve cross sections from each nerve were graded for injury by five independent masked observers. For fellow eyes, mean light- and dark-phase IOP was 21 +/- 1 and 31 +/- 1 mm Hg, respectively. For four experimental eyes, mean IOPs for both phases were not altered. Six eyes demonstrated significant mean IOP elevations only during the dark phase. Of these, five showed persistent, large circadian oscillations, and four had partial optic nerve lesions. The remaining seven eyes experienced significant IOP elevations during both phases, and all had extensive optic nerve damage. Episcleral vein injection of hypertonic saline is more likely to increase IOP during the dark phase than the light. This is consistent with aqueous outflow obstruction superimposed on a circadian rhythm of aqueous humor production. Because these periodic IOP elevations produced optic nerve lesions, both light- and dark-phase IOP determinations are necessary for accurate correlation of IOP history to optic nerve damage in animals housed in a light- dark environment.
A Tiered Approach to Evaluating Salinity Sources in Water at Oil and Gas Production Sites.
Paquette, Shawn M; Molofsky, Lisa J; Connor, John A; Walker, Kenneth L; Hopkins, Harley; Chakraborty, Ayan
2017-09-01
A suspected increase in the salinity of fresh water resources can trigger a site investigation to identify the source(s) of salinity and the extent of any impacts. These investigations can be complicated by the presence of naturally elevated total dissolved solids or chlorides concentrations, multiple potential sources of salinity, and incomplete data and information on both naturally occurring conditions and the characteristics of potential sources. As a result, data evaluation techniques that are effective at one site may not be effective at another. In order to match the complexity of the evaluation effort to the complexity of the specific site, this paper presents a strategic tiered approach that utilizes established techniques for evaluating and identifying the source(s) of salinity in an efficient step-by-step manner. The tiered approach includes: (1) a simple screening process to evaluate whether an impact has occurred and if the source is readily apparent; (2) basic geochemical characterization of the impacted water resource(s) and potential salinity sources coupled with simple visual and statistical data evaluation methods to determine the source(s); and (3) advanced laboratory analyses (e.g., isotopes) and data evaluation methods to identify the source(s) and the extent of salinity impacts where it was not otherwise conclusive. A case study from the U.S. Gulf Coast is presented to illustrate the application of this tiered approach. © 2017, National Ground Water Association.
NASA Astrophysics Data System (ADS)
Pan, Luqing; Xie, Peng; Hu, Fawen
2010-09-01
In this study, we investigated the effects of low salinity (26 and 21) on the prophenoloxidase (proPO) system and related defence parameters in the shrimp Litopenaeus vannamei. The results showed that low salinity induced a significant increase of dopamine (DA) concentration in haemolymph at 6 h of the experiment; on the other hand, total haemocyte count (THC), differential haemocyte count (DHC) and PO activity decreased over time to the lowest level at 24 h and remained low thereafter. Serine Protease (SP) and Proteinase Inhibitor (PI) activity in the two lower salinity treatments decreased to the lowest level at 12 and 24 h, respectively, and both recovered to the control level at 72 h. In contrast, α2- macroglobulin (α2M) activity in the two lower salinity treatments peaked at 24 h and then decreased to the control level at 72 h. Therefore, it may be concluded that stress-induced DA plays an important temporary role in neurotransmission and causes immune response in L. vannamei in adapting to salinity changes.
Kuznetsova, E G; Amstislavskaia, T G; Bulygina, V V; Il'nitskaia, S I; Tibeĭkina, M A; Skrinskaia, Iu A
2006-06-01
DBA/2 male mice were treated with monosodium glutamate (MSG) in a dose of 4 mg/g on 1, 3, 5, 7, 9 days after birth. Saline treated and intact males were used as control groups. MSG treated males displayed decreased number of crossed squares, rearings, entries in the centre and time in the centre of open field in comparison with saline-treated but not intact animals. Time in the light compartment of the light-dark box was increased in MSG-treated mice versus both saline treated and intact animals. MSG administration reduced acoustic startle response but did not affect the magnitude of prepulse inhibition of the startle reflex. Sexual motivation in male mice was reduced by MSG, the same trend was observed after saline treatment. MSG administration increased corticosterone basal level 4-fold while saline treatment did not affect it. These data suggest that neonatal administration of MSG decreases locomotion, exploratory activity, anxiety in male mice, while corticosterone level is increased. Saline treatment increases these parameters (except sexual motivation), and this augmentation is not connected to changes in corticosterone basal level.
Development of doxorubicin-induced chronic cardiotoxicity in the B6C3F{sub 1} mouse model
DOE Office of Scientific and Technical Information (OSTI.GOV)
Desai, Varsha G., E-mail: varsha.desai@fda.hhs.gov; Herman, Eugene H.; Moland, Carrie L.
2013-01-01
Serum levels of cardiac troponins serve as biomarkers of myocardial injury. However, troponins are released into the serum only after damage to cardiac tissue has occurred. Here, we report development of a mouse model of doxorubicin (DOX)-induced chronic cardiotoxicity to aid in the identification of predictive biomarkers of early events of cardiac tissue injury. Male B6C3F{sub 1} mice were administered intravenous DOX at 3 mg/kg body weight, or an equivalent volume of saline, once a week for 4, 6, 8, 10, 12, and 14 weeks, resulting in cumulative DOX doses of 12, 18, 24, 30, 36, and 42 mg/kg, respectively.more » Mice were sacrificed a week following the last dose. A significant reduction in body weight gain was observed in mice following exposure to a weekly DOX dose for 1 week and longer compared to saline-treated controls. DOX treatment also resulted in declines in red blood cell count, hemoglobin level, and hematocrit compared to saline-treated controls after the 2nd weekly dose until the 8th and 9th doses, followed by a modest recovery. All DOX-treated mice had significant elevations in cardiac troponin T concentrations in plasma compared to saline-treated controls, indicating cardiac tissue injury. Also, a dose-related increase in the severity of cardiac lesions was seen in mice exposed to 24 mg/kg DOX and higher cumulative doses. Mice treated with cumulative DOX doses of 30 mg/kg and higher showed a significant decline in heart rate, suggesting drug-induced cardiac dysfunction. Altogether, these findings demonstrate the development of DOX-induced chronic cardiotoxicity in B6C3F{sub 1} mice. -- Highlights: ► 24 mg/kg was a cumulative cardiotoxic dose of doxorubicin in male B6C3F{sub 1} mice. ► Doxorubicin-induced hematological toxicity was in association with splenomegaly. ► Doxorubicin induced severe testicular toxicity in B6C3F{sub 1} male mice.« less
The environmental fluid dynamics code (EFDC) was used to study the three dimensional (3D) circulation, water quality, and ecology in Narragansett Bay, RI. Predictions of the Bay hydrodynamics included the behavior of the water surface elevation, currents, salinity, and temperatur...
Arbuscular mycorrhizal fungi increase salt tolerance of apple seedlings.
Yang, Shou-Jun; Zhang, Zhong-Lan; Xue, Yuan-Xia; Zhang, Zhi-Fen; Shi, Shu-Yi
2014-12-01
Apple trees are often subject to severe salt stress in China as well as in the world that results in significant loss of apple production. Therefore this study was carried out to evaluate the response of apple seedlings inoculated with abuscular mycorrhizal fungi under 0, 2‰, 4‰ and 6‰ salinity stress levels and further to conclude the upper threshold of mycorrhizal salinity tolerance. The results shows that abuscular mycorrhizal fungi significantly increased the root length colonization of mycorrhizal apple plants with exposure time period to 0, 2‰ and 4‰ salinity levels as compared to non-mycorrhizal plants, however, percent root colonization reduced as saline stress increased. Salinity levels were found to negatively correlate with leaf relative turgidity, osmotic potential irrespective of non-mycorrhizal and mycorrhizal apple plants, but the decreased mycorrhizal leaf turgidity maintained relative normal values at 2‰ and 4‰ salt concentrations. Under salt stress condition, Cl - and Na + concentrations clearly increased and K + contents obviously decreased in non-mycorrhizal roots in comparison to mycorrhizal plants, this caused mycorrhizal plants had a relatively higher K + /Na + ratio in root. In contrast to zero salinity level, although ascorbate peroxidase and catalase activities in non-inoculated and inoculated leaf improved under all saline levels, the extent of which these enzymes increased was greater in mycorrhizal than in non-mycorrhizal plants. The numbers of survived tree with non-mycorrhization were 40, 20 and 0 (i.e., 66.7%, 33.3% and 0) on the days of 30, 60 and 90 under 4‰ salinity, similarly in mycorrhization under 6‰ salinity 40, 30 and 0 (i.e., 66.7%, 50% and 0) respectively. These results suggest that 2‰ and 4‰ salt concentrations may be the upper thresholds of salinity tolerance in non-mycorrhizal and mycorrhizal apple plants, respectively.
Levy, Jason A; Bachur, Richard G; Monuteaux, Michael C; Waltzman, Mark
2013-03-01
We seek to determine whether an initial intravenous bolus of 5% dextrose in normal saline solution compared with normal saline solution will lead to a lower proportion of hospitalized patients and a greater reduction in serum ketone levels in children with gastroenteritis and dehydration. We enrolled children aged 6 months to 6 years in a double-blind, randomized controlled trial of patients presenting to a pediatric emergency department. Subjects were randomized to receive a 20 mL/kg infusion of either 5% dextrose in normal saline solution or normal saline solution. Serum ketone levels were measured before and at 1- and 2-hour intervals after the initial study fluid bolus administration. Primary outcome was the proportion of children hospitalized. Secondary outcome was change in serum ketone levels over time. One hundred eighty-eight children were enrolled. The proportion of children hospitalized did not differ between groups (35% in the 5% dextrose in normal saline solution group versus 44% in the normal saline solution group; risk difference 9%; 95% confidence interval [CI] -5% to 22%). Compared with children who received normal saline solution, those who received 5% dextrose in normal saline solution had a greater reduction in mean serum ketone levels at both 1 hour (mean Δ 1.2 versus 0.1 mmol/L; mean difference 1.1 mmol/L; 95% CI 0.4 to 1.9 mmol/L) and 2 hours (mean Δ 1.9 versus 0.3 mmol/L; mean difference 1.6 mmol/L; 95% CI 0.9 to 2.3 mmol/L). Administration of a dextrose-containing bolus compared with normal saline did not lead to a lower rate of hospitalization for children with gastroenteritis and dehydration. There was, however, a greater reduction in serum ketone levels in patients who received 5% dextrose in normal saline solution. Copyright © 2012. Published by Mosby, Inc.
Marashi, Seyed Mojtaba; Hassan Nikkhouei, Reza; Movafegh, Ali; Shoeibi, Gita; Marashi, Shaqayeq
2015-01-01
Background: Because blood pressure and heart rate (HR) elevations during tracheal extubation are common, different medications have been studied to prevent such complications. Objectives: To compare magnesium sulfate, remifentanil, and placebo regarding mean arterial pressure (MAP) and HR changes during/after tracheal extubation, in patients who underwent laparotomy. Materials and Methods: In this randomized double-blinded trial, 120 patients undergoing laparotomy were evenly divided into three groups, including remifentanil (1 mcg/kg), magnesium sulfate (50 mg/kg), or normal saline, as placebo. Hemodynamic responses (MAP and HR) were documented at different times (before operation, during medication administration, immediately before extubation, immediately after extubation, and also 3, 5, and 10 minutes after extubation). The double burst time (DBT) was determined using neuromuscular monitoring, as time interval, between administration of reverse medication and DBT of 100%. Results: The HR was significantly lower, immediately after extubation and 3, 5, and 10 minutes after extubation, in both magnesium and remifentanil groups, compared to normal saline (P < 0.001). The MAP was also lower in magnesium and remifentanil groups, immediately after extubation and 3 minutes after extubation, in comparison to the normal saline group (P < 0.001). Mean (± SD) DBT 100% was significantly higher in magnesium group (30.2 ± 15.3) vs. remifenatnil (13.6 ± 6.8) and normal saline (13.5 ± 8.2) groups (P < 0.001). Conclusions: Both remifentanil and magnesium had favorable outcomes in preventing HR and MAP elevation after tracheal extubation. However, remifentanil was associated with more rapid regaining of consciousness and reversal of muscular relaxation. PMID:26478862
Tillman, Fred; Anning, David W.; Heilman, Julian A.; Buto, Susan G.; Miller, Matthew P.
2018-01-01
Elevated concentrations of dissolved-solids (salinity) including calcium, sodium, sulfate, and chloride, among others, in the Colorado River cause substantial problems for its water users. Previous efforts to reduce dissolved solids in upper Colorado River basin (UCRB) streams often focused on reducing suspended-sediment transport to streams, but few studies have investigated the relationship between suspended sediment and salinity, or evaluated which watershed characteristics might be associated with this relationship. Are there catchment properties that may help in identifying areas where control of suspended sediment will also reduce salinity transport to streams? A random forests classification analysis was performed on topographic, climate, land cover, geology, rock chemistry, soil, and hydrologic information in 163 UCRB catchments. Two random forests models were developed in this study: one for exploring stream and catchment characteristics associated with stream sites where dissolved solids increase with increasing suspended-sediment concentration, and the other for predicting where these sites are located in unmonitored reaches. Results of variable importance from the exploratory random forests models indicate that no simple source, geochemical process, or transport mechanism can easily explain the relationship between dissolved solids and suspended sediment concentrations at UCRB monitoring sites. Among the most important watershed characteristics in both models were measures of soil hydraulic conductivity, soil erodibility, minimum catchment elevation, catchment area, and the silt component of soil in the catchment. Predictions at key locations in the basin were combined with observations from selected monitoring sites, and presented in map-form to give a complete understanding of where catchment sediment control practices would also benefit control of dissolved solids in streams.
NASA Astrophysics Data System (ADS)
Harkness, J.; Darrah, T.; Warner, N. R.; Whyte, C. J.; Moore, M. T.; Millot, R.; Kloppmann, W.; Jackson, R. B.; Vengosh, A.
2017-12-01
Naturally occurring methane is nearly ubiquitous in most sedimentary basins and delineating the effects of anthropogenic contamination sources from geogenic sources is a major challenge for evaluating the impact of unconventional shale gas development on water quality. This study employs a broadly integrated study of various geochemical techniques to investigate the geochemical variations of groundwater and surface water before, during, and after hydraulic fracturing.This approache combines inorganic geochemistry (major cations and anions), stable isotopes of select inorganic constituents including strontium (87Sr/86Sr), boron (δ11B), lithium (δ7Li), and carbon (δ13C-DIC), select hydrocarbon molecular (methane, ethane, propane, butane, and pentane) and isotopic tracers (δ13C-CH4, δ13C-C2H6), tritium (3H), and noble gas elemental and isotopic composition (He, Ne, Ar) to apportion natural and anthropogenic sources of natural gas and salt contaminants both before and after drilling. Methane above 1 ccSTP/L in groundwater samples awas strongly associated with elevated salinity (chloride >50 mg/L).The geochemical and isotopic analysis indicate saline groundwater originated via naturally occurring processes, presumably from the migration of deeper methane-rich brines that have interacted extensively with coal lithologies. The chemistry and gas compostion of both saline and fresh groundwater wells did not change following the installation of nearby shale-gas wells.The results of this study emphasize the value of baseline characterization of water quality in areas of fossil fuel exploration. Overall this study presents a comprehensive geochemical framework that can be used as a template for assessing the sources of elevated hydrocarbons and salts to water resources in areas potentially impacted by oil and gas development.
Salinity-dependent mechanisms of copper toxicity in the galaxiid fish, Galaxias maculatus.
Glover, Chris N; Urbina, Mauricio A; Harley, Rachel A; Lee, Jacqueline A
2016-05-01
The euryhaline galaxiid fish, inanga (Galaxias maculatus) is widely spread throughout the Southern hemisphere occupying near-coastal streams that may be elevated in trace elements such as copper (Cu). Despite this, nothing is known regarding their sensitivity to Cu contamination. The mechanisms of Cu toxicity in inanga, and the ameliorating role of salinity, were investigated by acclimating fish to freshwater (FW), 50% seawater (SW), or 100% SW and exposing them to a graded series of Cu concentrations (0-200μgL(-1)) for 48h. Mortality, whole body Cu accumulation, measures of ionoregulatory disturbance (whole body ions, sodium (Na) influx, sodium/potassium ATPase activity) and ammonia excretion were monitored. Toxicity of Cu was greatest in FW, with mortality likely resulting from impaired Na influx. In both FW and 100% SW, ammonia excretion was significantly elevated, an effect opposite to that observed in previous studies, suggesting fundamental differences in the effect of Cu in this species relative to other studied fish. Salinity was protective against Cu toxicity, and physiology seemed to play a more important role than water chemistry in this protection. Inanga are sensitive to waterborne Cu through a conserved impairment of Na ion homeostasis, but some effects of Cu exposure in this species are distinct. Based on effect concentrations, current regulatory tools and limits are likely protective of this species in New Zealand waters. Copyright © 2016 Elsevier B.V. All rights reserved.
Muschamp, John W; Regina, Meredith J; Hull, Elaine M; Winter, Jerrold C; Rabin, Richard A
2004-10-08
The ability of hallucinogens to increase extracellular glutamate in the prefrontal cortex (PFC) was assessed by in vivo microdialysis. The hallucinogen lysergic acid diethylamide (LSD; 0.1 mg/kg, i.p.) caused a time-dependent increase in PFC glutamate that was blocked by the 5-HT(2A) antagonist M100907 (0.05 mg/kg, i.p.). Similarly, the 5-HT(2A/C) agonist [-]-2,5-dimethoxy-4-methylamphetamine (DOM; 0.6 mg/kg, i.p.), which is a phenethylamine hallucinogen, increased glutamate to 206% above saline-treated controls. When LSD (10 microM) was directly applied to the PFC by reverse dialysis, a rapid increase in PFC glutamate levels was observed. Glutamate levels in the PFC remained elevated after the drug infusion was discontinued. These data provide direct evidence in vivo for the hypothesis that an enhanced release of glutamate is a common mechanism in the action of hallucinogens.
NASA Astrophysics Data System (ADS)
Wang, A.; Zheng, M.; Kong, F.; Sobron, P.; Mayer, D. P.
2010-12-01
Qinghai-Tibet (QT) Plateau has the highest average elevation on Earth (~ 4500 m, about 50-60% of atmospheric pressure at sea-level). The high elevation induces a tremendous diurnal (and seasonal) temperature swing caused by high level of solar irradiation during the day and low level of atmospheric insulation during the evening. In addition, the Himalaya mountain chain (average height >6100 m) in the south of the QT Plateau largely blocks the pathway of humid air from the Indian Ocean, and produces a Hyperarid region (Aridity Index, AI ~ 0.04), the Qaidam Basin (N32-35, E90-100) at the north edge of the QT Plateau. Climatically, the low P, T, large ΔT, high aridity, and high UV radiation all make the Qaidam basin to be one of the most similar places on Earth to Mars. Qaidam basin has the most ancient playas (up to Eocene) and the lakes with the highest salinity on QT Plateau. More importantly, Mg-sulfates appear in the evaporative salts within the most ancient playas (Da Langtang) at the northwest corner of Qaidam basin, which mark the final stage of the evaporation sequence of brines rich in K, Na, Ca, Mg, Fe, C, B, S, and Cl. The evaporation minerals in the saline playas of Qaidam basin, their alteration and preservation under hyperarid conditions can be an interesting analog for the study of Martian salts and salty regolith. We conducted a field investigation at Da Langtan playa in Qaidam basin, with combined remote sensing (ASTER on board of NASA’s Terra satellite, 1.656, 2.167, 2.209, 2.62, 2.336, 2.40 µm), in situ sensing of a portable NIR spectrometer (WIR, 1.25-2.5 µm continuous spectral range), and the laboratory analyses of collected samples from the field (ASD spectrometer, 0.4 -2.5 µm, and Laser Raman spectroscopy). The results indicate that the materials contributing the high albedo layers in playa deposits are carbonate-gypsum-bearing surface soils, salt-clay-bearing exhaumed Pleistocene deposits, dehydrated Na-sulfates, hydrous Mg- & multication-sulfates, carbonates, and chlorites. Halophiles were isolated from the collected evaporative salt samples from Da Langtan. They were cultured on modified growth medium (MGM) under different salinity conditions, and eight strains of halobacteria showed different growth curves. 16S rRNA gene sequences for these eight strains suggested that the halophiles from Da Langtan had high homology with some species of genera of Virgibacillus, Oceanobacillus, Halobacillus, and Ter-ribacillus. In conclusion, the climatic conditions and salt mineralogy within the lacustrine deposits at Da Langtan playa, northwest corner of the Qaidam basin on Qinghai-Tibet Plateau, indicate that this area can be an excellent analog site for studying the precipitation sequence and the subsequent dehydration/degeneration of Martian salts. The finding of hylophyles in this hyperarid environment boosts the importance of exploring salty regolith in future surface explorations to Mars (MSL and ExoMars) in the search for similar biosignatures.
Corticotropin-releasing hormone and dopamine release in healthy individuals.
Payer, Doris; Williams, Belinda; Mansouri, Esmaeil; Stevanovski, Suzanna; Nakajima, Shinichiro; Le Foll, Bernard; Kish, Stephen; Houle, Sylvain; Mizrahi, Romina; George, Susan R; George, Tony P; Boileau, Isabelle
2017-02-01
Corticotropin-releasing hormone (CRH) is a key component of the neuroendocrine response to stress. In animal models, CRH has been shown to modulate dopamine release, and this interaction is believed to contribute to stress-induced relapse in neuropsychiatric disorders. Here we investigated whether CRH administration induces dopamine release in humans, using positron emission tomography (PET). Eight healthy volunteers (5 female, 22-48 years old) completed two PET scans with the dopamine D 2/3 receptor radioligand [ 11 C]-(+)-PHNO: once after saline injection, and once after injection of corticorelin (synthetic human CRH). We also assessed subjective reports and measured plasma levels of endocrine hormones (adrenocorticotropic hormone and cortisol). Relative to saline, corticorelin administration decreased binding of the D 2/3 PET probe [ 11 C]-(+)-PHNO, suggesting dopamine release. Endocrine stress markers were also elevated, in line with activation of the hypothalamic-pituitary-adrenal axis, but we detected no changes in subjective ratings. Preliminary results from this proof-of-concept study suggests that CRH challenge in combination with [ 11 C]-(+)-PHNO PET may serve as an assay of dopamine release, presenting a potential platform for evaluating CRH/dopamine interactions in neuropsychiatric disorders and CRH antagonists as potential treatment avenues. Copyright © 2016 Elsevier Ltd. All rights reserved.
Heath, Michele; Raghunathan, Karthik; Welsby, Ian; Maxwell, Cory
2014-01-01
Abstract: Avoiding or managing hyperkalemia during cardiac surgery, especially in a patient with chronic renal insufficiency, can be challenging. Hyperkalemic cardioplegia solution is usually administered to achieve and maintain an electrical arrest of the heart. This solution eventually mixes in with the systemic circulation, contributing to elevated systemic potassium levels. Administration of packed red blood cells, hemolysis, tissue damage, and acidosis are also common causes of hyperkalemia. Current strategies to avoid or manage hyperkalemia include minimizing the volume of cardioplegia administered, shifting potassium from the extracellular into the intracellular space (by the administration of sodium bicarbonate when the pH is low and/or dextrose–insulin when effects relatively independent of serum pH are desired), using zero-balanced ultrafiltration (Z-BUF) with normal saline as the replacement fluid (to remove potassium from the body rather than simply shift the electrolyte across cellular membranes), and, occasionally, hemodialysis (1). We report the application of Z-BUF using an electrolyte-balanced, low potassium dialysate solution rather than isotonic saline to avoid a high chloride load and the potential for hyperchloremic acidosis to successfully treat hyperkalemia while on cardiopulmonary bypass. PMID:26357794
Blockade of nitric oxide synthesis modulates rat immunoglobulin A.
Budec, Mirela; Marković, Dragana; Djikić, Dragoslava; Mitrović, Olivera; Drndarević, Neda; Koko, Vesna; Todorović, Vera
2009-01-01
Nitric oxide (NO) is known as a regulator of inflammation and immunity. The purpose of this study was to investigate the influence of this signal molecule on the rat immunoglobulin A (IgA) system using Nomega-nitro-L-arginine-methyl ester (L-NAME), which inhibits the activity of all isoforms of NO synthase. The experiments were performed on adult female Wistar rats showing diestrus day 1 that were treated with L-NAME (30 or 50 mg/kg, s.c.). Untreated and saline-injected animals were used as controls. The rats were sacrificed 3 h following L-NAME or saline administration. The concentration of IgA in serum and intestinal extracts was determined by a sandwich enzyme-linked immunosorbent assay. The number of IgA-expressing cells per area unit of Peyer's patches and the intestinal lamina propria was evaluated using stereological analysis. The results showed that L-NAME decreased the level of IgA in serum and elevated its concentration in intestinal extracts. Additionally, the increased number of IgA+ cells was found in the intestinal lamina propria in both experimental groups. Obtained findings imply that endogenous NO may modulate the IgA system in the rat. Copyright 2009 S. Karger AG, Basel.
Hong, Sungwoo; Kim, Seong-Cheol; Kwon, Taekmin; Jeong, In Gab; Kim, Choung-Soo; Ahn, Hanjong; Hong, Jun Hyuk
2014-01-01
The aim of this study was to evaluate the effect of bladder tumor (BT) location on prostate cancer (PCa) detection in patients with elevated PSA levels after intravesical BCG instillation. Between February 2004 and January 2013 prostate biopsies were performed in 59 non-muscle invasive bladder cancer (NMIBC) patients whose PSA level were elevated (≥3 ng/ml) after a 6 week course of intravesical BCG (Oncotice, 12.5 mg in 50 ml normal saline). Differences in PCa detection according to the BT location [bladder neck and/or trigone (Group 1, n = 22) vs. other locations (Group 2, n = 37)] were evaluated. The Fisher's exact test and the Mann-Whitney U test were used to evaluate the association between categorical and continuous variables, respectively. A total of 14 patients (23.7%) were diagnosed with PCa. The mean ± standard deviation (SD) PSA before intravesical BCG instillation and prostate biopsy were 1.36±1.04 ng/ml in Group 1 and 1.09±1.12 ng/ml in Group 2 (P = 0.633), and 6.05±3.57 ng/ml in Group 1 and 5.13±3.88 ng/ml in Group 2 (P = 0.378), respectively. Interestingly, whereas PCa was detected upon biopsy in only one patient in Group 1 (4.5%), 13 cases were detected in Group 2 (35.1%) (P = 0.009). PCa detection after intravesical BCG was highly associated with BT location. Prostate biopsy should therefore be considered when PSA level is elevated after BCG instillation and his BT is located far from the bladder neck.
Babri, Shirin; Doosti, Mohammad-Hossein; Salari, Ali-Akbar
2014-03-01
There is converging evidence that prenatal maternal infection can increase the risk of occurrence of neuropsychiatric disorders like schizophrenia, autism, anxiety and depression in later life. Experimental studies have shown conflicting effects of prenatal maternal immune activation on anxiety-like behavior and hypothalamic-pituitary-adrenal (HPA) axis development in offspring. We investigated the effects of maternal immune activation during pregnancy on anxiety- and depression-like behaviors in pregnant mice and their offspring to determine whether these effects are dependent on strain. NMRI and C57BL/6 pregnant mice were treated with either saline or lipopolysaccharide on gestational day 17 and then interleukin (IL)-6 and corticosterone (COR) levels; anxiety or depression in the pregnant mice and their offspring were evaluated. The results indicate that maternal inflammation increased the levels of COR and anxiety-like behavior in NMRI pregnant mice, but not in C57BL/6 dams. Our data also demonstrate that maternal inflammation elevated the levels of anxiety-and depression-like behaviors in NMRI offspring on the elevated plus-maze, elevated zero-maze, tail suspension test and forced swimming test respectively, but not in the open field and light-dark box. In addition, we did not find any significant change in anxiety- and depression-like behaviors of adult C57BL/6 offspring. Our findings suggest that prenatal maternal immune activation can alter the HPA axis activity, anxiety- and depression-like behaviors in a strain- and task-dependent manner in offspring and further comprehensive studies are needed to prove the causal relationship between the findings found here and to validate their relevance to neuropsychiatric disorders in humans. Copyright © 2013 Elsevier Inc. All rights reserved.
Warming and Acidification Induced Mass Mortality of a Coastal Keystone predator
NASA Astrophysics Data System (ADS)
Melzner, F.; Findeisen, U.
2016-02-01
The Baltic Sea is characterized by low salinity and pronounced fluctuations in pCO2. On-line monitoring of pCO2 in 2014 in Kiel Fjord demonstrated occurrence of peak values of >2,000 µatm in summer and autumn and average values >750 µatm. We assessed the impacts of elevated temperature (ambient temperature, ambient +3°C) and pCO2 (500, 1,500, 2,400 µatm) on the keystone species Asterias rubens in a fully crossed long - term experiment (N=5 replicate tanks each, 1 year duration). During spring and early summer (February - June), high temperature animals ingested significantly more food and spawned significantly earlier (April 30th) than ambient acclimated animals (May 23rd). Elevated pCO2 led to comparatively minor reductions in food intake and scope for growth during that period. During summer (June - August), elevated temperature >25°C caused negative energy budgets and >95% mortality in the warm acclimated groups, while mortality was low in the ambient temperature groups. Our results indicate that A. rubens may benefit from increased temperature during colder months, yet dramatically suffer during summer heat waves in warm years. Meaningful experimental approaches to assess species vulnerability to climate change need to encompass all seasons and realistic abiotic stressor levels.
Reliability and sensitivity of the TonoLab rebound tonometer in awake Brown Norway rats.
Morrison, John C; Jia, Lijun; Cepurna, William; Guo, Ying; Johnson, Elaine
2009-06-01
To compare the sensitivity of the TonoLab rebound tonometer with the Tono-Pen in awake Brown Norway rats and to compare their ability to predict optic nerve damage induced by experimental IOP elevation. TonoLab and Tono-Pen tonometers were calibrated in cannulated rat eyes connected to a pressure transducer. The TonoLab was used in awake animals housed in standard lighting to measure IOP during light and dark phases. Both instruments were used to monitor chronically elevated IOP produced by episcleral vein injection of hypertonic saline. Measured IOPs were correlated with quantified optic nerve damage in injected eyes. Although they were lower than transducer and Tono-Pen measurements at all levels, TonoLab readings showed an excellent linear fit with transducer readings from 20 to 80 mm Hg (R(2) = 0.99) in cannulated eyes. In awake animals housed in standard lighting, the TonoLab documented significantly higher pressures during the dark phase (27.9 +/- 1.7 mm Hg) than during the light phase (16.7 +/- 2.3 mm Hg). With elevated IOP, correlation between TonoLab and Tono-Pen readings (R(2) = 0.86, P < 0.0001) was similar to that in cannulated eyes. Although both instruments provided measurements that correlated well with optic nerve injury grade, only the Tono-Pen documented significant IOP elevation in eyes with the least amount of injury (P < 0.05). The TonoLab is sensitive enough to be used in awake Brown Norway rats, though instrument fluctuation may limit its ability to identify significant pressure elevations in eyes with minimal optic nerve damage.
Macler, Bruce A.
1988-01-01
The long-term effects of altered salinities on the physiology of the intertidal red alga Gelidium coulteri Harv. were assessed. Plants were transfered from 30 grams per liter salinity to media with salinities from 0 to 50 grams per liter. Growth rate, agar, photosynthesis, respiration, and various metabolites were quantified after 5 days and 5 weeks adaptation. After 5 days, growth rates were lower for plants at all altered salinities. Growth rates recovered from these values with 5 weeks adaptation, except for salinities of 10 grams per liter and below, where tissues bleached and died. Photosynthetic O2 evolution was lower than control values at both higher and lower salinities after 5 days and did not change over time. Carbon fixation at the altered salinities was unchanged after 5 days, but decreased below 25 grams per liter and above 40 grams per liter after 5 weeks. Respiration increased at lower salinities. Phycobili-protein and chlorophyll were lower for all altered salinities after 5 days. These decreases continued at lower salinities, then were stable after 5 weeks. Chlorophyll recovered over time at higher salinities. Decreases in protein at lower salinities were quantitatively attributable to phycobili-protein loss. Total N levels and C:N ratios were nearly constant across all salinities tested. Carbon flow into glutamate and aspartate decreased with both decreasing and increasing salinities. Glycine, serine, and glycolate levels increased with both increasing and decreasing salinity, indicating a stimulation of photorespiration. The cell wall component agar increased with decreasing salinity, although biosynthesis was inhibited at both higher and lower salinities. The storage compound floridoside increased with increasing salinity. The evidence suggests stress responses to altered salinities that directly affected photosynthesis, respiration, and nitrogen assimilation and indirectly affected photosynthate flow. At low salinities, respiration and photorespiration exceeded photosynthesis with lethal results. At higher salinities, although photosynthesis was inhibited, respiration was low and carbon fixation adequate to offset increased photorespiration. PMID:16666369
Macler, B A
1988-11-01
The long-term effects of altered salinities on the physiology of the intertidal red alga Gelidium coulteri Harv. were assessed. Plants were transfered from 30 grams per liter salinity to media with salinities from 0 to 50 grams per liter. Growth rate, agar, photosynthesis, respiration, and various metabolites were quantified after 5 days and 5 weeks adaptation. After 5 days, growth rates were lower for plants at all altered salinities. Growth rates recovered from these values with 5 weeks adaptation, except for salinities of 10 grams per liter and below, where tissues bleached and died. Photosynthetic O(2) evolution was lower than control values at both higher and lower salinities after 5 days and did not change over time. Carbon fixation at the altered salinities was unchanged after 5 days, but decreased below 25 grams per liter and above 40 grams per liter after 5 weeks. Respiration increased at lower salinities. Phycobili-protein and chlorophyll were lower for all altered salinities after 5 days. These decreases continued at lower salinities, then were stable after 5 weeks. Chlorophyll recovered over time at higher salinities. Decreases in protein at lower salinities were quantitatively attributable to phycobili-protein loss. Total N levels and C:N ratios were nearly constant across all salinities tested. Carbon flow into glutamate and aspartate decreased with both decreasing and increasing salinities. Glycine, serine, and glycolate levels increased with both increasing and decreasing salinity, indicating a stimulation of photorespiration. The cell wall component agar increased with decreasing salinity, although biosynthesis was inhibited at both higher and lower salinities. The storage compound floridoside increased with increasing salinity. The evidence suggests stress responses to altered salinities that directly affected photosynthesis, respiration, and nitrogen assimilation and indirectly affected photosynthate flow. At low salinities, respiration and photorespiration exceeded photosynthesis with lethal results. At higher salinities, although photosynthesis was inhibited, respiration was low and carbon fixation adequate to offset increased photorespiration.
USDA-ARS?s Scientific Manuscript database
Background/Question/Methods: Salinity is one of the main abiotic factors in salt marshes. Studies rooted to analyzed salinity tolerance of halophytes may help to relate their physiological tolerances with distribution limits in the field. Climate change-induced sea level rise and higher temperatures...
NASA Astrophysics Data System (ADS)
Wang, Guodong; Xu, Kefeng; Tian, Xiangli; Dong, Shuanglin; Fang, Ziheng
2015-10-01
A serial of salinity transferring treatments were performed to investigate the osmoregulation of tongue sole ( Cynoglossus semilaevis). Juvenile tongue sole were directly transferred from a salinity of 30 to 0, 10, 20, 30, 40 and 50. Blood sampling was performed for each treatment after 0, 1, 6 and 12 h, as well as after 1, 2, 4, 8, 16 and 32 d. The plasma osmolality, cortisol and free amino acids were assessed. Under the experimental conditions, no fish died after acute salinity transfer. The plasma cortisol level increased 1 h after the abrupt transfer from a salinity of 30 to that of 0, 40 and 50, and decreased from 6 h to 8 d after transfer. Similar trends were observed in the changes of plasma osmolality. The plasma free amino acids concentration showed a `U-shaped' relationship with salinity after being transferred to different salinities for 4 days. More obvious changes of plasma free amino acid concentration occurred under hyper-osmotic conditions than under hypo-osmotic conditions. The concentrations of valine, isoleucine, lysine, glutamic acid, glycine, proline and taurine increased with rising salinity. The plasma levels of threonine, leucine, arginine, serine, and alanine showed a `U-shaped' relationship with salinity. The results of this study suggested that free amino acids might have important effects on osmotic acclimation in tongue sole.
Intraspecific variation in the response of Taxodium distichum seedlings to salinity
Allen, J.A.; Chambers, J.L.; McKinney, D.
1994-01-01
Seedlings of 15 open-pollinated families of baldcypress (Taxodium distichum) were tested for their tolerance to combined salinty and flooding stress. Ten of the families were from coastal locations in Louisiana or Alabama, USA, that were slightly brackish. The other families were from locations not affected by saltwater intrusion. Five salinity levels were investigated--0,2,4,6, and 8 g -1 artificial seawater -- all with flooding to approximately 5 cm above the soil surface. Survival, height growth, leaf area and total biomass all declined with increasing salinity. Significant variation was found among salinity levels, families, and salinity x family interactions for leaf area and total biomass. Two tolerance indices were also developed to compare family response with salinity. In general, families from brackish sources had greater total biomass, leaf area, and tolerance index values than families from freshwater sources at the higher slainity levels. A selection and breeding program designed to develop moderately salt-tolerant baldcypress seedlings for use in wetland restoration projects and other applications appears to be well-justified.
Extinction Memory Improvement by the Metabolic Enhancer Methylene Blue
ERIC Educational Resources Information Center
Gonzalez-Lima, F.; Bruchey, Aleksandra K.
2004-01-01
We investigated whether postextinction administration of methylene blue (MB) could enhance retention of an extinguished conditioned response. MB is a redox compound that at low doses elevates cytochrome oxidase activity, thereby improving brain energy production. Saline or MB (4 mg/kg intraperitoneally) were administered to rats for 5 d following…
Marine Benthic Communities of Block Island and Rhode Island Sounds and What they're Good For
The benthic invertebrates of Block Island and Rhode Island Sounds include those adapted to near-shore habitats with variable temperature and salinity, mid-shelf species with narrower requirements, and boreal species that avoid elevated temperatures. Studies of benthic fauna in th...
Taniguchi, Takeshi; Imada, Shogo; Acharya, Kumud; Iwanaga, Fumiko; Yamanaka, Norikazu
2015-01-01
Tamarix ramosissima is a tree species that is highly resistant to salt and drought. The Tamarix species survives in a broad range of environmental salt levels, and invades major river systems in southwestern United States. It may affect root-associated bacteria (RB) by increasing soil salts and nutrients. The effects of RB on host plants may vary even under saline conditions, and the relationship may be important for T. ramosissima. However, to the best of our knowledge, there have been no reports relating to T. ramosissima RB and its association with salinity and nutrient levels. In this study, we have examined this association and the effect of arbuscular mycorrhizal colonization of T. ramosissima on RB because a previous study has reported that colonization of arbuscular mycorrhizal fungi affected the rhizobacterial community (Marschner et al., 2001). T. ramosissima roots were collected from five locations with varying soil salinity and nutrient levels. RB community structures were examined by terminal restriction fragment (T-RF) length polymorphism, cloning, and sequencing analyses. The results suggest that RB richness, or the diversity of T. ramosissima, have significant negative relationships with electrical conductivity (EC), sodium concentration (Na), and the colonization of arbuscular mycorrhizal fungi, but have a significant positive relationship with phosphorus in the soil. However, at each T-RF level, positive correlations between the emergence of some T-RFs and EC or Na were observed. These results indicate that high salinity decreased the total number of RB species, but some saline-tolerant RB species multiplied with increasing salinity levels. The ordination scores of nonmetric multidimensional scale analysis of RB community composition show significant relationships with water content, calcium concentration, available phosphorus, and total nitrogen. These results indicate that the RB diversity and community composition of T. ramosissima are affected by soil salinity and nutrient levels. Sequence analysis detected one Bacteroidetes and eight Proteobacteria species. Most 16S rRNA gene sequences had high similarities with the bacteria isolated from saline conditions, indicating that at least a portion of the RB species observed in T. ramosissima was halotolerant.
Nitrogen removal via nitrite from seawater contained sewage.
Peng, Yongzhen; Yu, De-Shuang; Liang, Dawei; Zhu, Guibing
2004-01-01
Under the control of both pH and the concentration of free ammonia (FA), the nitrification-denitrification via nitrite pathway was accomplished in SBR to achieve enhanced biological nitrogen removal from seawater contained wastewater, which is used to flush toilet, under relatively high salinity. Several parameters including salinity, temperature, pH, and NH4+-N loading rate were studied to evaluate their effects. The results indicate that at different salinity the nitrogen removal efficiency is relative to ammonia-nitrogen loading rate. The nitrogen removal efficiency reaches above 90% when the NH4+-N loading does not exceed 0.15 kg NH4+-N/kg MLSS d. With the salinity increasing, the ammonia-nitrogen loading rate should be lowered to obtain high removal efficiency. The evaluation of temperature effect shows that nitrogen removal efficiency is promoted twice when reaction temperature is elevated from 20 to 30 degrees C. Moderately high pH in the range of 7.5-8.5 has advantage to achieve effective nitrification-denitrification via nitrite, the process of which is caused by the selective inhibition of free ammonia (FA).
Xiao, Meng; Sun, Shan-Shan; Zhang, Zhong-Zhi; Wang, Jun-Ming; Qiu, Long-Wei; Sun, Hua-Yang; Song, Zhao-Zheng; Zhang, Bei-Yu; Gao, De-Li; Zhang, Guang-Qing; Wu, Wei-Min
2016-01-20
The community diversities of two oil reservoirs with low permeability of 1.81 × 10(-3) and 2.29 × 10(-3) μm(2) in Changqing, China, were investigated using a high throughput sequencing technique to analyze the influence of biostimulation with a nutrient activator on the bacterial communities. These two blocks differed significantly in salinity (average 17,500 vs 40,900 mg/L). A core simulation test was used to evaluate the effectiveness of indigenous microbial-enhanced oil recovery (MEOR). The results indicated that in the two high salinity oil reservoirs, one reservoir having relatively lower salinity level and a narrow salinity range had higher bacterial and phylogenetic diversity. The addition of the nutrient activator increased the diversity of the bacterial community structure and the diversity differences between the two blocks. The results of the core simulation test showed that the bacterial community in the reservoir with a salinity level of 17,500 mg/L did not show significant higher MEOR efficiency compared with the reservoir with 40,900 mg/L i.e. MEOR efficiency of 8.12% vs 6.56% (test p = 0.291 > 0.05). Therefore, salinity levels affected the bacterial diversities in the two low permeability oil blocks remarkably. But the influence of salinity for the MEOR recovery was slightly.
Enwright, Nicholas M.; Griffith, Kereen T.; Osland, Michael J.
2015-11-02
In this study, the U.S. Geological Survey, in cooperation with the U.S. Fish and Wildlife Service, quantified the potential for landward migration of tidal saline wetlands along the U.S. Gulf of Mexico coast under alternative future sea-level rise and urbanization scenarios. Our analyses focused exclusively on tidal saline wetlands (that is, mangrove forests, salt marshes, and salt flats), and we combined these diverse tidal saline wetland ecosystems into a single grouping, “tidal saline wetland.” Collectively, our approach and findings can provide useful information for scientists and environmental planners working to develop future-focused adaptation strategies for conserving coastal landscapes and the ecosystem goods and services provided by tidal saline wetlands. The primary product of this work is a public dataset that identifies locations where landward migration of tidal saline wetlands is expected to occur under alternative future sea-level rise and urbanization scenarios. In addition to identifying areas where landward migration of tidal saline wetlands is possible because of the absence of barriers, these data also identify locations where landward migration of these wetlands could be prevented by barriers associated with current urbanization, future urbanization, and levees.
Medeiros, N; Rivero, D H R F; Kasahara, D I; Saiki, M; Godleski, J J; Koutrakis, P; Capelozzi, V L; Saldiva, P H N; Antonangelo, L
2004-05-01
Several epidemiological studies have consistently demonstrated significant associations between ambient levels of particulate matter and lung injury and cardiovascular events with increased morbidity and mortality. Particle surrogates (PS), such as residual oil fly ash (ROFA), have been widely used in experimental studies aimed at characterizing the mechanisms of particle toxicity. Since PS composition varies depending on its source, studies with different types of PS may provide clues about the relative toxicity of the components generated by high-temperature combustion process. In this work, we have studied the effects of nasal instillation of increasing doses of different PS in mice: saline, carbon, and two types of particle surrogates. PS type A (PSA) was the ROFA collected from the waste incinerator of our university hospital; PS type B (PSB) was collected from the electrostatic precipitator of a large steel company and thus had an elevated metal content. After 24h, we analyzed hematological parameters, fibrinogen, bronchoalveolar lavage, bone marrow, and pulmonary histology. Nasal instillation of the two types of PS-induced leucopenia. PSB elicited a greater elevation of plasma fibrinogen levels. Bone marrow and pulmonary inflammatory changes were more intense for PSA. We concluded that the PS composition modulates acute inflammatory changes more significantly than the mass for these two types of PS.
Xie, Shiwei; Fang, Weiping; Wei, Dan; Liu, Yongjian; Yin, Peng; Niu, Jin; Tian, Lixia
2018-06-20
A 25-days experiment was conducted to evaluate the effect of dietary Haematococcus pluvialis on growth, survival, immune response and stress tolerance ability of post-larval Litopenaeus vannamei. Post-larval white shrimp (mean initial weight 2.1 mg) were fed five isoenergic and isonitrogenous diets containing grade levels of Haematococcus pluvialis (0, 1.7, 3.3, 6.7 and 13.3 g kg -1 diet, respectively). Results indicated that 3.3 g Haematococcus pluvialis kg -1 diet increased the survival rate of post-larval white shrimp. Specific growth rate (SGR) and weight gain (WG) showed no difference among each groups. After the acute salinity stress (salinity decreased rapidly from 28‰ to 5‰), survival of shrimp fed 6.7 g Haematococcus pluvialis kg -1 diet significant higher than the control (P < 0.05), and the total antioxidant capacity (T-AOC) was increased with the increasing dietary Haematococcus pluvialis levels. The malonaldehyde (MDA) contents in whole body decreased with the increasing dietary Haematococcus pluvialis levels before and after the salinity stress. Before the salinity stress, relative mRNA levels of Caspase 3, Rho and Janus kinase (JAK) decreased in shrimp fed diets contain Haematococcus pluvialis. After the salinity stress, relative mRNA levels of anti-oxidative related genes and immune related genes decreased with the dietary Haematococcus pluvialis level increased to 3.3 g kg -1 . Based on the effect of Haematococcus pluvialis on survival, salinity stress tolerance ability and the immune response of post-larval L. vannamei, the optimal level of Haematococcus pluvialis was 3.3-6.7 g kg -1 diet (100-200 mg astaxanthin kg -1 diet). Copyright © 2018. Published by Elsevier Ltd.
Effects of saline drinking water on early gosling development
Stolley, D.S.; Bissonette, J.A.; Kadlec, J.A.; Coster, D.
1999-01-01
Relatively high levels of saline drinking water may adversely affect the growth, development, and survival of young waterfowl. Saline drinking water was suspect in the low survival rate of Canada goose (Branta canadensis) goslings at Fish Springs National Wildlife Refuge (FSNWR) in western Utah. Hence, we investigated the effects of saline drinking water on the survival and growth of captive, wild-strain goslings from day 1-28 following hatch. We compared survival and growth (as measured by body mass, wing length, and culmen length) between a control group on tap water with a mean specific conductivity of 650 ??S/cm, and 2 saline water treatments: (1) intermediate level (12,000 ??S/cm), and (2) high level (18,000 ??S/cm). Gosling mortality occurred only in the 18,000 ??S/cm treatment group (33%; n = 9). Slopes of regressions of mean body mass, wing length, and culmen length on age were different from each other (P < 0.05), except for culmen length for the intermediate and high treatment levels. We predict that free-ranging wild goslings will experience mortality at even lower salinity levels than captive goslings because of the combined effects of depressed growth and environmental stresses, including hot desert temperatures and variable food quality over summer.
Naftz, David L.; Carling, Gregory T.; Angeroth, Cory; Freeman, Michael; Rowland, Ryan; Pazmiño, Eddy
2014-01-01
Density stratification in saline and hypersaline water bodies from throughout the world can have large impacts on the internal cycling and loading of salinity, nutrients, and trace elements. High temporal resolution hydroacoustic and physical/chemical data were collected at two sites in Great Salt Lake (GSL), a saline lake in the western USA, to understand how density stratification may influence salinity and mercury (Hg) distributions. The first study site was in a causeway breach where saline water from GSL exchanges with less saline water from a flow restricted bay. Near-surface-specific conductance values measured in water at the breach displayed a good relationship with both flow and wind direction. No diurnal variations in the concentration of dissolved (total and MeHg loadings was observed during periods of elevated salinity. The second study site was located on the bottom of GSL where movement of a high-salinity water layer, referred to as the deep brine layer (DBL), is restricted to a naturally occurring 1.5-km-wide “spillway” structure. During selected time periods in April/May, 2012, wind-induced flow reversals in a railroad causeway breach, separating Gunnison and Gilbert Bays, were coupled with high-velocity flow pulses (up to 55 cm/s) in the DBL at the spillway site. These flow pulses were likely driven by a pressure response of highly saline water from Gunnison Bay flowing into the north basin of Gilbert Bay. Short-term flow reversal events measured at the railroad causeway breach have the ability to move measurable amounts of salt and Hg from Gunnison Bay into the DBL. Future disturbance to the steady state conditions currently imposed by the railroad causeway infrastructure could result in changes to the existing chemical balance between Gunnison and Gilbert Bays. Monitoring instruments were installed at six additional sites in the DBL during October 2012 to assess impacts from any future modifications to the railroad causeway.
NASA Astrophysics Data System (ADS)
Bittar, Thais B.; Berger, Stella A.; Birsa, Laura M.; Walters, Tina L.; Thompson, Megan E.; Spencer, Robert G. M.; Mann, Elizabeth L.; Stubbins, Aron; Frischer, Marc E.; Brandes, Jay A.
2016-12-01
Tidal Spartina-dominated saltmarshes and estuaries on the Southeast US coast are global hotspots of productivity. In coastal Georgia, tidal amplitudes and saltmarsh productivity are the highest along the Southeast US coast. Coastal Georgia is characterized by a humid subtropical seasonal climate, and inter-annual variability in precipitation, and freshwater discharge. The 2012-2013 timeframe encompassed contrasting levels of discharge for the Savannah River, a major Georgia river, with a 4.3-fold greater discharge in summer 2013 relative to summer 2012. In situ measurements of temperature, salinity, precipitation and Secchi depth, and water samples were collected weekly at high tide throughout 2012 and 2013 from the Skidaway River Estuary, a tidal saltmarsh-dominated estuary in coastal Georgia influenced by Savannah River hydrology. The effects of elevated discharge on the seasonal trends of water column components were evaluated. The shift from low discharge (2012) to high discharge (2013) led to decreased salinity in summer 2013, but no significant increases in inorganic nutrient (NH4, NOx, SiO2 and PO4) concentrations. Dissolved inorganic carbon (DIC) concentrations decreased, and DIC stable isotopic signatures (δ13C-DIC values) were depleted in summer 2013 relative to summer 2012. In 2013 dissolved organic carbon (DOC) concentrations, chromophoric and fluorescent dissolved organic matter (DOM: CDOM, FDOM) intensities, specific UV-absorbance (SUVA254) and relative humic-like fluorescence were all higher than in 2012, indicating that, as discharge increased in 2013, estuarine water became enriched in terrigenous DOM. Secchi depth and particulate organic carbon (POC) and nitrogen (PON) concentrations displayed clear seasonal patterns that were not significantly altered by discharge. However, δ13C-POC and δ15N-PON isotopic signatures indicated higher terrigenous contributions at elevated discharge. Discharge influenced cyanobacterial composition, but did not affect total abundance of phytoplankton (<52 μm) or chlorophyll-a concentrations, a proxy for phytoplankton biomass. Phytoplankton community dynamics were primarily seasonally-driven. Bacterioplankton abundance and community composition, based upon flow cytometry, were affected by discharge, possibly due to decreased salinity and/or increased inputs of terrigenous DOM. Seasonal patterns in inorganic nutrient, POC, PON and chlorophyll-a concentrations, and Secchi depth were not significantly influenced by the 2013 increase in discharge. For other components, most notably δ13C-DIC values, DOM and bacterioplankton, the influence of increased discharge in 2013 was superimposed upon their seasonal patterns. This study showed that in addition to tidal mixing and in situ saltmarsh and estuarine production and removal processes, the level of riverine freshwater discharge impacted the quantity and character of many water column components in this tidal saltmarsh ecosystem.
Li, Shu; Lu, DanDan; Zhang, Yaling; Zhang, Yi
2014-01-01
The present study was designed to test the hypothesis that long-term treatment with hydrogen-rich saline abated testicular oxidative stress induced by nicotine in mice. The effects of hydrogen-rich saline (6 ml/kg, i.p.), vitamin C (60 mg/kg, i.p.) and vitamin E (100 mg/kg, i.p.) on reproductive system and testicular oxidative levels in nicotine-treated (4.5 mg/kg, s.b.) mice were investigated. It was found that vitamin C and vitamin E attenuated serum oxidative level, but did not lower testicular oxidative levels in mice subjected to chronic nicotine treatment, and did not improve the male reproductive damage and apoptosis induced by nicotine. Different from normal antioxidants, vitamin C and vitamin E, hydrogen-rich saline abated oxidative stress in testis, and protected against nicotine-induced male reproductive damages. Our results first demonstrated that long-term treatment with hydrogen-rich saline attenuated testicular oxidative level and improved male reproductive function in nicotine-treated mice.
Hughan, Kara S; Bonadonna, Riccardo C; Lee, SoJung; Michaliszyn, Sara F; Arslanian, Silva A
2013-05-01
Overweight/obese (OW/OB) African American (AA) adolescents have a more diabetogenic insulin secretion/sensitivity pattern compared with their American white (AW) peers. The present study investigated β-cell lipotoxicity to test whether increased free fatty acid (FFA) levels result in greater β-cell dysfunction in AA vs AW OW/OB adolescents. Glucose-stimulated insulin secretion was modeled, from glucose and C-peptide concentrations during a 2-hour hyperglycemic (225 mg/dL) clamp in 22 AA and 24 AW OW/OB adolescents, on 2 occasions after a 12-hour overnight infusion of either normal saline or intralipid (IL) in a random sequence. β-Cell function relative to insulin sensitivity, the disposition index (DI), was examined during normal saline and IL conditions. Substrate oxidation was evaluated with indirect calorimetry and body composition and abdominal adiposity with dual-energy X-ray absorptiometry and magnetic resonance imaging at L4-L5, respectively. Age, sex, body mass index, total and sc adiposity were similar between racial groups, but visceral adiposity was significantly lower in AAs. During IL infusion, FFAs and fat oxidation increased and insulin sensitivity decreased similarly in AAs and AWs. β-Cell glucose sensitivity of first- and second-phase insulin secretion did not change significantly during IL infusion in either group, but DI in each phase decreased significantly and similarly in AAs and AWs. Overweight/obese AA and AW adolescents respond to an overnight fat infusion with significant declines in insulin sensitivity, DI, and β-cell function relative to insulin sensitivity, suggestive of β-cell lipotoxicity. However, contrary to our hypothesis, there does not seem to be a race differential in β-cell lipotoxicity. Longer durations of FFA elevation may unravel such race-related contrasts.
Bagosi, Zsolt; Palotai, Miklós; Simon, Balázs; Bokor, Péter; Buzás, András; Balangó, Beáta; Pintér, Dávid; Jászberényi, Miklós; Csabafi, Krisztina; Szabó, Gyula
2016-12-01
The aim of the present study was to investigate the effects of the selective agonists of the corticotropin-releasing factor (CRF) 2 receptor, urocortin 2 (UCN 2) and urocortin 3 (UCN 3), on the anxiety- and depression-like signs induced by acute nicotine withdrawal in mice. In order to do so, male CFLP mice were exposed for 7 days to repeated intraperitoneal (IP) injection with nicotine or saline solution and 1day of acute withdrawal and then a single intracerebroventricular (ICV) injection with UCN 2, UCN 3 or saline solution. After 30min the mice were observed in an elevated plus-maze test or a forced swim test, for anxiety- and depression-like behavior. After 5min of testing, the plasma corticosterone concentration reflecting the activity of the hypothalamic-pituitary-adrenal (HPA) axis was also determined by a chemo-fluorescent method. Half of the animals were treated ICV and evaluated on the 8th day, the other half on the 9th day. On the 8th day, nicotine-treated mice presented signs of anxiolysis and depression, but no significant elevation of the plasma corticosterone concentration. On the 9th day, nicotine-treated mice exhibited signs of anxiety and depression and a significant increase of the plasma corticosterone levels. Central administration of UCN 2 or UCN 3 ameliorated the anxiety- and depression-like state including the hyperactivity of the HPA axis, developed during acute withdrawal following chronic nicotine treatment. The present study suggests that selective CRF2 receptor agonists could be used as a therapy in nicotine addiction. Copyright © 2016 Elsevier B.V. All rights reserved.
Landscape scale assessment of soil and water salinization processes in agricultural coastal area.
NASA Astrophysics Data System (ADS)
Elen Bless, Aplena; Follain, Stéphane; Coiln, François; Crabit, Armand
2017-04-01
Soil salinization is among main land degradation process around the globe. It reduces soil quality, disturbs soil function, and has harmful impacts on plant growth that would threaten agricultural sustainability, particularly in coastal areas where mostly susceptible on land degradation because of pressure from anthropogenic activities and at the same time need to preserve soil quality for supporting food production. In this presentation, we present a landscape scale analysis aiming to assess salinization process affecting wine production. This study was carried out at Serignan estuary delta in South of France (Languadoc Roussillon Region, 43˚ 28'N and 3˚ 31'E). It is a sedimentary basin near coastline of Mediterranean Sea. Field survey was design to characterize both space and time variability of soil and water salinity through water electrical conductivity (ECw) and soil 1/5 electrical conductivity (EC1/5). For water measurements, Orb River and groundwater salinity (piezometers) were determined and for soil 1737 samples were randomly collected from different soil depths (20, 50, 80, and 120 cm) between year 2012 and 2016 and measured. In order to connect with agricultural practices observations and interviews with farmers were conducted. We found that some areas combining specific criteria presents higher electrical conductivity: positions with lower elevation (a.s.l), Cambisols (Calcaric) / Fluvisols soil type (WRB) and dominated clay textures. These observations combined with geochemical determination and spatial analysis confirm our first hypothesis of sea salt intrusion as the main driven factor of soil salinity in this region. In this context, identification of salinization process, fine determination of pedological specificities and fine understanding of agricultural practices allowed us to proposed adaptation strategies to restore soil production function. Please fill in your abstract text. Key Words: Salinity, Coastal Agriculture, Landscape, Soil, Water
Faleiros, Rogério O; Garçon, Daniela P; Lucena, Malson N; McNamara, John C; Leone, Francisco A
2018-06-19
The evolutionary history of the Crustacea reveals ample adaptive radiation and the subsequent occupation of many osmotic niches resulting from physiological plasticity in their osmoregulatory mechanisms. We evaluate osmoregulatory ability in the intertidal, thinstripe hermit crab Clibanarius symmetricus after short-term exposure (6 h) or long-term acclimation (10 days) to a wide salinity range, also analyzing kinetic behavior and α-subunit mRNA expression of the gill (Na + , K + )-ATPase. The crab strongly hyper-regulates its hemolymph at 5 and 15‰S (Salinity, g L -1 ) but weakly hyper-regulates up to ≈27‰S. After 6 h exposure to 35‰S and 45‰S, C. symmetricus slightly hypo-regulates its hemolymph, becoming isosmotic after 10 days acclimation to these salinities. (Na + , K + )-ATPase specific activity decreases with increasing salinity for both exposure periods, reflecting physiological adjustment to isosmoticity. At low salinities, the gill enzyme exhibits a single, low affinity ATP binding site. However, at elevated salinities, a second, high affinity, ATP binding site appears, independently of exposure time. (Na + , K + )-ATPase α-subunit mRNA expression increases only after 10 days acclimation to 5‰S. Our findings suggest that hemolymph hyper-regulation is effected by alterations in enzyme activity during short-term exposure, but is sustained by increased mRNA expression during long-term acclimation. The decrease in gill (Na + , K + )-ATPase activity seen as a consequence of increasing salinity appears to underlie biochemical adjustments to hemolymph isosmoticity as hypo-regulatory ability diminishes. Copyright © 2018. Published by Elsevier Inc.
NASA Astrophysics Data System (ADS)
Li, Erchao; Arena, Leticia; Lizama, Gabriel; Gaxiola, Gabriela; Cuzon, Gerard; Rosas, Carlos; Chen, Liqiao; van Wormhoudt, Alain
2011-03-01
Improvement in the osmoregulation capacity via nutritional supplies is vitally important in shrimp aquaculture. The effects of dietary protein levels on the osmoregulation capacity of the Pacific white shrimp ( L. vannamei) were investigated. This involved an examination of growth performance, glutamate dehydrogenase (GDH) and Na+-K+ ATPase mRNA expression,, and GDH activity in muscles and gills. Three experimental diets were formulated, containing 25%, 40%, and 50% dietary protein, and fed to the shrimp at a salinity of 25. After 20 days, no significant difference was observed in weight gain, though GDH and Na+-K+ ATPase gene expression and GDH activity increased with higher dietary protein levels. Subsequently, shrimp fed diets with 25% and 50% dietary protein were transferred into tanks with salinities of 38 and 5, respectively, and sampled at weeks 1 and 2. Shrimp fed with 40% protein at 25 in salinity (optimal conditions) were used as a control. Regardless of the salinities, shrimp fed with 50% dietary protein had significantly higher growth performance than other diets; no significant differences were found in comparison with the control. Shrimp fed with 25% dietary protein and maintained at salinities of 38 and 5 had significantly lower weight gain values after 2 weeks. Ambient salinity change also stimulated the hepatosomatic index, which increased in the first week and then recovered to a relatively normal level, as in the control, after 2 weeks. These findings indicate that in white shrimp, the specific protein nutrient and energy demands related to ambient salinity change are associated with protein metabolism. Increased dietary protein level could improve the osmoregulation capacity of L. vannamei with more energy resources allocated to GDH activity and expression.
Herrera, Marcelino; Aragão, Cláudia; Hachero, Ismael; Ruiz-Jarabo, Ignacio; Vargas-Chacoff, Luis; Mancera, Juan Miguel; Conceição, Luis E C
2012-12-01
The physiological responses of Senegalese sole to a sudden salinity change were investigated. The fish were first acclimated to an initial salinity of 37.5 ppt for 4 h. Then, one group was subjected to increased salinity (55 ppt) while another group was subjected to decreased salinity (5 ppt). The third group (control group) remained at 37.5 ppt. We measured the oxygen consumption rate, osmoregulatory (plasma osmolality, gill and kidney Na(+),K(+)-ATPase activities) and stress (plasma cortisol and metabolites) parameters 0.5 and 3 h after transfer. Oxygen consumption at both salinities was higher than for the control at both sampling times. Gill Na(+),K(+)-ATPase activity was significantly higher for the 55 ppt salinity at 0.5 h. Plasma osmolality decreased in the fish exposed to 5 ppt at the two sampling times but no changes were detected for high salinities. Plasma cortisol levels significantly increased at both salinities, although these values declined in the low-salinity group 3 h after transfer. Plasma glucose at 5 ppt salinity did not vary significantly at 0.5 h but decreased at 3 h, while lactate increased for both treatments at the first sampling time and returned to the control levels at 3 h. Overall, the physiological response of S. senegalensis was immediate and involved a rise in oxygen consumption and plasma cortisol values as well as greater metabolite mobilization at both salinities.
USDA-ARS?s Scientific Manuscript database
The aim of this study was to determine the salt tolerance of pepper (Capsicum annuum L.) under greenhouse conditions and to examine the interactive effects of salinity and nitrogen (N) fertilizer levels on yield. The present study shows the effects of optimal and suboptimal N fertilizer levels (270 ...
Prazeres, Ana R; Carvalho, Fátima; Rivas, Javier; Patanita, Manuel; Dôres, Jóse
2013-01-01
Pretreated cheese whey wastewater (CWW) has been used at different salinity levels: 1.75, 2.22, 3.22, 5.02 and 10.02 dS m(-1) and compared with fresh water (1.44 dS m(-1)). Two cultivars (cv.) of the tomato plant Lycopersicon Esculentum Mill. (Roma and Rio Grande) were exposed to saline conditions for 72 days. Salinity level (treatment) had no significant effects on the fresh weight and dry matter of the leaves, stems and roots. Similar results were found when specific leaf area, leaflet area, ramifications number of 1st order/plant, stem diameter and length, nodes number/stem and primary root length were considered. Conversely, the salinity level significantly influenced the Soil Plant Analysis Development (SPAD) index and the distance between nodes in the plant stem. In the first case, an increase of 21% was obtained in the salinity levels of 5.02 and 10.02 dS m(-1) for cv. Rio Grande, compared with the control run. The results showed that the pretreated CWW can be a source of nutrients for tomato plants, with reduced effects on growth and development.
Pérez-Pérez, J G; Syvertsen, J P; Botía, P; García-Sánchez, F
2007-08-01
Since salinity and drought stress can occur together, an assessment was made of their interacting effects on leaf water relations, osmotic adjustment and net gas exchange in seedlings of the relatively chloride-sensitive Carrizo citrange, Citrus sinensis x Poncirus trifoliata. Plants were fertilized with nutrient solution with or without additional 100 mm NaCl (salt and no-salt treatments). After 7 d, half of the plants were drought stressed by withholding irrigation water for 10 d. Thus, there were four treatments: salinized and non-salinized plants under drought-stress or well-watered conditions. After the drought period, plants from all stressed treatments were re-watered with nutrient solution without salt for 8 d to study recovery. Leaf water relations, gas exchange parameters, chlorophyll fluorescence, proline, quaternary ammonium compounds and leaf and root concentrations of Cl(-) and Na(+) were measured. Salinity increased leaf Cl(-) and Na(+) concentrations and decreased osmotic potential (Psi(pi)) such that leaf relative water content (RWC) was maintained during drought stress. However, in non-salinized drought-stressed plants, osmotic adjustment did not occur and RWC decreased. The salinity-induced osmotic adjustment was not related to any accumulation of proline, quaternary ammonium compounds or soluble sugars. Net CO(2) assimilation rate (A(CO2)) was reduced in leaves from all stressed treatments but the mechanisms were different. In non-salinized drought-stressed plants, lower A(CO2) was related to low RWC, whereas in salinized plants decreased A(CO2) was related to high levels of leaf Cl(-) and Na(+). A(CO2) recovered after irrigation in all the treatments except in previously salinized drought-stressed leaves which had lower RWC and less chlorophyll but maintained high levels of Cl(-), Na(+) and quaternary ammonium compounds after recovery. High leaf levels of Cl(-) and Na(+) after recovery apparently came from the roots. Plants preconditioned by salinity stress maintained a better leaf water status during drought stress due to osmotic adjustment and the accumulation of Cl(-) and Na(+). However, high levels of salt ions impeded recovery of leaf water status and photosynthesis after re-irrigation with non-saline water.
Xu, Qianghua; Qin, Ye
2012-09-01
Heat shock protein 60 (HSP60) is a highly conserved and multi-functional molecular chaperone that plays an essential role in both cellular metabolism and stress response. Portunus trituberculatus is an important marine fishery and aquaculture species, and water salinity condition influenced its artificial propagations significantly. In order to investigate the function of P. trituberculatus HSP60 against osmotic stress, P. trituberculatus HSP60 gene was firstly cloned. The full-length cDNA of PtHSP60 contains 1,743 nucleotides encoding 577 amino acids with a calculated molecular weight of 61.25 kDa. Multiple alignments indicated that the deduced amino acid sequences of PtHSP60 shared a high level of identity with invertebrate and vertebrate HSP60 sequence including shrimp, fruit fly, zebrafish, and human. The expression profiles of PtHSP60 at mRNA and protein levels under salinity treatment were investigated by semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blot analysis, respectively. It was found that the mRNA transcripts of PtHSP60 gene varied among different tissues under normal salinity conditions, and the antennal gland showed the highest expression level among the tissues tested. As for low salinity challenge, the mRNA expression of PtHSP60 gene was higher in the gill and appendicular muscle compared with other tissues, and gill and hypodermis represented the higher gene expressions during the hyperosmotic stress, which indicated that those tissues were salinity-sensitive tissues. In addition, salinity challenges significantly altered the expression of PtHSP60 at mRNA and protein level in a salinity- and time-dependent manner in P. trituberculatus gill tissue. The results indicate that PtHSP60 played important roles in mediating the salinity stress in P. trituberculatus.
Woo, I.; Takekawa, John Y.
2012-01-01
In the San Francisco Bay Estuary, CA, USA, sea level rise (SLR) is projected to increase by 1.4 m during the next 90 years resulting in increased inundation and salt water intrusion up-estuary. Since inundation and salinity are critical factors that drive vegetation structure and composition in coastal wetlands, we asked whether inundation and salinity levels associated with SLR would reduce the survival, growth, and reproductive capacity of a dominant halophyte, Sarcocornia pacifica (pickleweed). We conducted a 4 × 4 factorial greenhouse experiment to examine the effects of a range of inundation periods (25, 50, 75, and 100%) and water salinities (0, 10, 20, 30 psu) on individual S. pacifica adults and seedlings. We found that inundation and salinity treatments affected the height of adults and seedlings combined. When examined separately, adult height was negatively affected by inundation ≥75%, while seedling height was affected by the interaction of both inundation and salinity. Adult belowground biomass was negatively affected by complete inundation. Seedling aboveground biomass decreased 46% at the highest salinity (30 psu) and belowground biomass decreased at salinities ≥20 psu. Adult flower production was not affected by treatments but was reduced by 38% at 30 psu salinity for seedlings. While adult survival was 99%, seedling survival was 56% with greatest mortality at low (25%) inundation, possibly because their roots were more susceptible to desiccation. Vegetation structure of the marsh platform comprised of S. pacifica adults will be susceptible to greater inundation rates associated with SLR. Our results suggest that adults may grow less tall, thus altering the vegetation structure and likely the tidal marsh wildlife that rely on these habitats.
Yamazaki, Y; Mimura, M; Hazama, K; Namiki, A
2000-04-25
An epidural injection of saline was reported to extend spinal anesthesia because of a volume effect. The aim of this study was to evaluate the influence of the baricity of spinal local anesthetics upon the extension of spinal anesthesia by epidural injection of saline. Forty patients undergoing elective lower-limb surgery were randomly allocated to four groups of 10 patients each. Group A received no epidural injection after the spinal administration of hyperbaric tetracaine (dissolved in 10% glucose). Group B received an epidural injection of 8 ml of physiological saline 20 min after spinal hyperbaric tetracaine. Group C received no epidural injection after spinal isobaric tetracaine (dissolved in physiological saline). Group D received an epidural injection of 8 ml of saline 20 min after spinal isobaric tetracaine. The level of analgesia was examined by the pinprick method at 5-min intervals. The levels of analgesia 20 min after spinal anesthesia were significantly higher in hyperbaric groups than in isobaric groups [T5 (T2-L2) vs. T7 (T3-12)]. After epidural injection of saline, the levels of analgesia in groups B and D were significantly higher than in groups A and C. The segmental increases after epidural saline injection were 2 (0-3) in group B and 2 (1-7) in group D. Sensation in the sacral area remained 20 min after spinal block in one patient in group D; however, it disappeared after epidural saline injection. In this study, 8 ml of epidural saline extended spinal analgesia. However, there was no difference between the augmenting effect in isobaric and hyperbaric spinal anesthesia. We conclude that the reinforcement of spinal anesthesia by epidural injection of saline is not affected by the baricity of the spinal anesthetic solution used.
Schofield, P J; Loftus, W F; Fontaine, J A
2009-04-01
This study quantified the hypoxia tolerance of the Mayan cichlid Cichlasoma urophthalmus over a range of salinities. The species was very tolerant of hypoxia, using aquatic surface respiration (ASR) and buccal bubble holding when oxygen tensions dropped to <20 mmHg (c. 1.0 mg l(-1)) and 6 mmHg, respectively. Salinity had little effect on the hypoxia tolerance of C. urophthalmus, except that bubble holding was more frequent at the higher salinities tested. Levels of aggression were greatest at the highest salinity. The ASR thresholds of C. urophthalmus were similar to native centrarchid sunfishes from the Everglades, however, aggression levels for C. uropthalmus were markedly higher.
NASA Astrophysics Data System (ADS)
Putnam, Daniel H.; Benes, Sharon; Galdi, Giuliano; Hutmacher, Bob; Grattan, Steve
2017-04-01
Alfalfa (Medicago sativa L.) is the most widely grown leguminous forage crop in North America and is valued for high productivity, quality, economic value, and for dairy productivity. Alfalfa has historically been classified as moderately sensitive to saline conditions, with yield declines predicted at >2 dS/m in the saturated soil paste extract. However, greenhouse, sand tank, and field studies over the past five years have confirmed that alfalfa can be grown with limited negative effects at much higher salinity levels. A broad collection of alfalfa varieties has exhibited a range of resistance at irrigation water salinities >5 dS/m ECw in greenhouse trials, with significant variation due to variety. USDA-ARS sand tank studies indicated similar or greater tolerances closer to 8 dS/m in the soil water, in addition to confirmation of significant varietal differences. A three-year field study on clay loam soil with applications of 5-7 dS/m ECw irrigation water indicated normal yields and excellent stand survivability. A second field study in the same soil type with levels from 8-10 dS/m ECw showed yield reductions of 10-15% but economic yields were still achieved at those levels. Field and greenhouse studies were conducted with mixed salt saline sodic waters typical of the San Joaquin Valley of California. Field evaluation of variety performance was subject to greater variation due to secondary salinity-soil interactions including water infiltration and crusting problems, not only salinity per-se. Thus, adequate irrigation water availability to the crop may be as important as salinity in impacting yields under field conditions. Once established, the deep-rooted characteristics of alfalfa enable utilization of deeper subsurface moisture, even at moderate to high salinity levels, as documented by USDA lysimeter studies. Significant advantages to salinity-tolerant varieties have been observed. It will be important to consider specific management factors which may enable the successful production of irrigated alfalfa with use of saline (up to 8 dS/m ECw) irrigation water, including careful water management during stand establishment, prevention of crusting, and agronomic practices to promote water infiltration. Irrigated regions looking for economically-viable crop species to grow under saline conditions may consider alfalfa grown utilizing appropriate methodologies, including salt-tolerant varieties and agronomic practices to mitigate the secondary effects of soil salinity and sodicity.
Curtis, Daniel L; McGaw, Iain J
2010-02-01
Respiratory responses and gastric processing were examined during hyposaline exposure in two crab species of differing osmoregulatory ability. The efficient osmoregulator, Callinectes sapidus, displayed an immediate increase in oxygen uptake when exposed to low salinity in isolation. In contrast, the weak osmoregulator, Cancer magister, showed no change in oxygen uptake upon acute exposure (<6 h), but slight increases in oxygen uptake tended to occur over longer time scales (12-24 h). These changes were likely attributable to an increase in avoidance activity after 6 h hyposaline exposure. Following feeding in 100% SW, oxygen uptake doubled for both species and remained elevated for 15 h. When postprandial crabs were exposed to low salinities, C. sapidus were able to sum the demands of osmoregulation and digestion. Thus, gastric processes continued unabated in low salinity. Conversely, postprandial C. magister prioritized responses to low salinity over those of digestion, resulting in a decrease in oxygen uptake when exposed to low salinity. This decrease in oxygen uptake corresponded to a reduction in the rate of contraction of the pyloric stomach and a subsequent doubling of gastric evacuation time. The current study is one of the few to illustrate how summation or prioritization of competing physiological systems is manifested in digestive processes.
Johari, Seyed Ali; Sarkheil, Mehrdad; Behzadi Tayemeh, Mohammad; Veisi, Shakila
2018-06-13
This study aim to evaluate the potential toxic effects of citrate coated silver nanoparticles (AgNPs) and ionic silver (AgNO 3 ) on marine microalgae Dunaliella salina under three different salinities (35, 70, and 140 g/L). The toxicity was investigated according to modified OECD guideline (No. 201) by 72 h exposure of microalgae to various concentrations of each of the chemicals in Walne's saline media. According to the results, the growth inhibitory effects of AgNPs and AgNO 3 increased significantly coincidence with increasing time and concentration compared to control (P < 0.05). The values of median inhibitory concentrations (IC 50 ) of AgNPs and AgNO 3 based on average specific growth rate and yield for D. salina increased significantly with elevation of water salinity from 35 to 140 g/L (P < 0.05). Toxicity of AgNO 3 based on IC 50 to D. salina was significantly higher than AgNPs at all salinities (P < 0.05). In conclusion, both AgNPs and AgNO 3 inhibited the growth of D. salina at different saltwater medium. Copyright © 2018 Elsevier Ltd. All rights reserved.
Response of Azospirillum brasilense Cd to sodium chloride stress.
Rivarola, V; Castro, S; Mori, G; Jofré, E; Fabra, A; Garnica, R; Balegno, H
1998-04-01
Growth of Azospirillum brasilense Cd in the presence of different NaCl concentrations showed that it tolerates up to 200 mM NaCl in the medium, without appreciable decline in growth rate. At 300 mM NaCl, a decrease of 66% in growth was observed at 24 h of culture. At 48 h of culture, bacteria in the presence of 300 mM NaCl reached the maximum optical density value that was attained at 12 h by control cultures. This investigation was designed to elucidate the effect of saline stress on Azospirillum brasilense Cd and the physiologic mechanism involved in its possible salinity tolerance. For this reason, studies of other osmolytes, as well as of putrescine metabolism and protein patterns were done with bacteria grown with this NaCl concentration in the medium, at 24 and at 48 hours. A. brasilense responded to saline stress elevating the intracellular concentration of glutamate at 24 h, and of K+ at 48 h. Glucan pattern, putrescine metabolism, and total and periplasmic protein patterns of the treated group showed several changes with respect to the control. In spite of the several cellular functions affected by saline stress, the results imply that A. brasilense Cd shows salinity tolerance in these experimental conditions.
Effects of ozone oxidative preconditioning on radiation-induced organ damage in rats
Gultekin, Fatma Ayca; Bakkal, Bekir Hakan; Guven, Berrak; Tasdoven, Ilhan; Bektas, Sibel; Can, Murat; Comert, Mustafa
2013-01-01
Because radiation-induced cellular damage is attributed primarily to harmful effects of free radicals, molecules with direct free radical scavenging properties are particularly promising as radioprotectors. It has been demonstrated that controlled ozone administration may promote an adaptation to oxidative stress, preventing the damage induced by reactive oxygen species. Thus, we hypothesized that ozone would ameliorate oxidative damage caused by total body irradiation (TBI) with a single dose of 6 Gy in rat liver and ileum tissues. Rats were randomly divided into groups as follows: control group; saline-treated and irradiated (IR) groups; and ozone oxidative preconditioning (OOP) and IR groups. Animals were exposed to TBI after a 5-day intraperitoneal pretreatment with either saline or ozone (1 mg/kg/day). They were decapitated at either 6 h or 72 h after TBI. Plasma, liver and ileum samples were obtained. Serum AST, ALT and TNF-α levels were elevated in the IR groups compared with the control group and were decreased after treatment with OOP. TBI resulted in a significant increase in the levels of MDA in the liver and ileal tissues and a decrease of SOD activities. The results demonstrated that the levels of MDA liver and ileal tissues in irradiated rats that were pretreated with ozone were significantly decreased, while SOD activities were significantly increased. OOP reversed all histopathological alterations induced by irradiation. In conclusion, data obtained from this study indicated that ozone could increase the endogenous antioxidant defense mechanism in rats and there by protect the animals from radiation-induced organ toxicity. PMID:22915786
Rise and Fall of one of World's largest deltas; the Mekong delta in Vietnam
NASA Astrophysics Data System (ADS)
Minderhoud, P. S. J.; Eslami Arab, S.; Pham, H. V.; Erkens, G.; van der Vegt, M.; Oude Essink, G.; Stouthamer, E.; Hoekstra, P.
2017-12-01
The Mekong delta is the third's largest delta in the world. It is home to almost 20 million people and an important region for the food security in South East Asia. As most deltas, the Mekong delta is the dynamic result of a balance of sediment supply, sea level rise and subsidence, hosting a system of fresh and salt water dynamics. Ongoing urbanization, industrialization and intensification of agricultural practices in the delta, during the past decades, resulted in growing domestic, agricultural and industrial demands, and have led to a dramatic increase of fresh water use. Since the year 2000, the amount of fresh groundwater extracted from the subsurface increased by 500%. This accelerated delta subsidence as the groundwater system compacts, with current sinking rates exceeding global sea level rise up to an order of magnitude. These high sinking rates have greatly altered the sediment budget of the delta and, with over 50% of the Mekong delta surface elevated less than 1 meter above sea level, greatly increase vulnerability to flooding and storm surges and ultimately, permanent inundation. Furthermore, as the increasingly larger extractions rapidly reduce the fresh groundwater reserves, groundwater salinization subsequently increases. On top of that, dry season low-flows by the Mekong river cause record salt water intrusion in the delta's estuarine system, creating major problems for rice irrigation. We present the work of three years research by the Dutch-Vietnamese `Rise and Fall' project on land subsidence and salinization in both groundwater and surface water in the Vietnamese Mekong delta.
Middleton, Beth A
2016-08-01
The nature of regeneration dynamics after hurricane flooding and salinity intrusion may play an important role in shaping coastal vegetation patterns. The regeneration potentials of coastal species, types and gradients (wetland types from seaward to landward) were studied on the Delmarva Peninsula after Hurricane Sandy using seed bank assays to examine responses to various water regimes (unflooded and flooded to 8 cm) and salinity levels (0, 1, and 5 ppt). Seed bank responses to treatments were compared using a generalized linear models approach. Species relationships to treatment and geographical variables were explored using nonmetric multidimensional scaling. Flooding and salinity treatments affected species richness even at low salinity levels (1 and 5 ppt). Maritime forest was especially intolerant of salinity intrusion so that species richness was much higher in unflooded and low salinity conditions, despite the proximity of maritime forest to saltmarsh along the coastal gradient. Other vegetation types were also affected, with potential regeneration of these species affected in various ways by flooding and salinity, suggesting relationships to post-hurricane environment and geographic position. Seed germination and subsequent seedling growth in coastal wetlands may in some cases be affected by salinity intrusion events even at low salinity levels (1 and 5 ppt). These results indicate that the potential is great for hurricanes to shift vegetation type in sensitive wetland types (e.g., maritime forest) if post-hurricane environments do not support the regeneration of extent vegetation. This article is a U.S. Government work and is in the public domain in the USA. © Botanical Society of America (outside the USA) 2016.
Salinization and Saline Environments
NASA Astrophysics Data System (ADS)
Vengosh, A.
2003-12-01
One of the most conspicuous phenomena of water-quality degradation, particularly in arid and semi-arid zones, is salinization of water and soil resources. Salinization is a long-term phenomenon, and during the last century many aquifers and river basins have become unsuitable for human consumption owing to high levels of salinity. Future exploitation of thousands of wells in the Middle East and in many other water-scarce regions in the world depends, to a large extent, on the degree and rate of salinization. Moreover, every year a large fraction of agricultural land is salinized and becomes unusable.Salinization is a global environmental phenomenon that affects many different aspects of our life (Williams, 2001a, b): changing the chemical composition of natural water resources (lakes, rivers, and groundwater), degrading the quality of water supply to the domestic and agriculture sectors, contribution to loss of biodiversity, taxonomic replacement by halotolerant species ( Williams, 2001a, b), loss of fertile soil, collapse of agricultural and fishery industries, changing of local climatic conditions, and creating severe health problems (e.g., the Aral Basin). The damage due to salinity in the Colorado River Basin alone, for example, ranges between 500 and 750 million per year and could exceed 1 billion per year if the salinity in the Imperial Dam increases from 700 mg L-1 to 900 mg L-1 (Bureau of Reclamation, 2003, USA). In Australia, accelerating soil salinization has become a massive environmental and economic disaster. Western Australia is "losing an area equal to one football oval an hour" due to spreading salinity ( Murphy, 1999). The annual cost for dryland salinity in Australia is estimated as AU700 million for lost land and AU$130 million for lost production ( Williams et al., 2002). In short, the salinization process has become pervasive.Salinity in water is usually defined by the chloride content (mg L-1) or total dissolved solids content (TDS, mg L-1or g L-1), although the chloride comprises only a fraction of the total dissolved salts in water. The Cl/TDS ratio varies from 0.1 in nonmarine saline waters to ˜0.5 in marine-associated saline waters. Water salinity is also defined by electrical conductivity (EC). In soil studies, the electrical conductivity and the ratio of Na/√(Ca+Mg) (SAR) are often used as an indirect measure of soil salinity. In addition to chloride, high levels of other dissolved constituents may limit the use of water for domestic, agriculture, and industrial applications. In some parts of Africa, China, and India, for example, high fluoride content is associated with saline groundwater and causes severe dental and skeletal fluorosis (Shiklomanov, 1997). Hence, the "salinity" problem is only the "tip of the iceberg," as high levels of salinity are associated with high concentrations of other inorganic pollutants (e.g., sodium, sulfate, boron, fluoride), and bioaccumulated elements (e.g., selenium, and arsenic) (see Chapter 9.03).The World Health Organization (WHO) recommends that the chloride concentration of the water supply for human consumption should not exceed 250 mg L-1. Agriculture applications also depend upon the salinity level of the supplied water. Many crops, such as citrus, avocado, and mango, are sensitive to chloride concentration in irrigation water (an upper limit of 250 mg L-1). In addition, long-term irrigation with water enriched with sodium results in a significant reduction in the hydraulic conductivity and hence the fertility of the irrigated soil. Similarly, the industrial sector demands water of high quality. For example, the high-tech industry requires a large amount of water with low levels of dissolved salts. Hence, the salinity level of groundwater is one of the limiting factors that determine the suitability of water for a variety of applications.The salinity problem is a global phenomenon but it is more severe in water-scarce areas, such as arid and semi-arid zones. The increasing demand for water has created tremendous pressures on water resources that have resulted in lowering water level and increasing salinization. For example, in the Middle East salinity is the main factor that limits water utilization, and future prospects for water use in Israel, Palestinian Authority, and Jordan are overshadowed by the increasing salinization (Vengosh and Rosenthal, 1994; Salameh, 1996). The salinity problem has numerous grave economic, social, and political consequences, particularly in cross-boundary basins that are shared by different communities (e.g., Salinas Valley California; Vengosh et al., 2002a), friendly states (e.g., salinization of the Colorado River along Mexico-US border; Stanton et al., 2001), and hostile states (e.g., the Jordan River, Vengosh et al., 2001; Aral Basin, Weinthal, 2002; Euphrates River, Beaumont, 1996; and the Nile River, Ohlsson, 1995).Salinization of water resources also affects agricultural management. The type of irrigation water and its quality determine the salinity and fertility of the soil and eventually the quality of the underlying water resource. The use of treated wastewater or other marginal water (e.g., brackish water) depends on the salinity and the chemical composition of the water. Treated wastewater with high contents of chloride, sodium, and boron is suitable only for salt-tolerant crops and requires special treatment of the soil. Finally, high boron in irrigation water and consequently in soil water is also an important limiting factor for crops, as boron is an essential micronutrient for plants but becomes toxic at high levels (typically >0.75 mg L-1 in irrigation water).This chapter investigates the different mechanisms and geochemistry of salinization in different parts of the world. The role of the unsaturated zone in shaping the chemical composition of dryland salinization is discussed. Special emphasis is on the anthropogenic effects and to man-made fluids and reused water, such as treated wastewater and agricultural drainage water. Two anthropogenic salinization cycles are introduced - the agricultural and the domestic cycles. Some useful geochemical fingerprinting tracers are also included for defining the sources of salinity. Finally, the chemical composition of future water resources is predicted, based on the chemical and isotopic fractionation associated with remediation and desalination.
Salinity affects behavioral thermoregulation in a marine decapod crustacean
NASA Astrophysics Data System (ADS)
Reiser, Stefan; Mues, Annika; Herrmann, Jens-Peter; Eckhardt, André; Hufnagl, Marc; Temming, Axel
2017-10-01
Thermoregulation in aquatic ectotherms is a complex behavioral pattern that is affected by various biotic and abiotic factors with one being salinity. Especially in coastal and estuarine habitats, altering levels of salinity involve osmoregulatory adjustments that affect total energy budgets and may influence behavioral responses towards temperature. To examine the effect of salinity on behavioral thermoregulation in a marine evertebrate ectotherm, we acclimated juvenile and sub-adult common brown shrimp (Crangon crangon, L.) to salinities of 10, 20 and 30 PSU and investigated their thermal preference in an annular chamber system using the gravitational method for temperature preference determination. Thermal preference of individual brown shrimp was considerably variable and brown shrimp selected a wide range of temperatures in each level of salinity as well as within individual experimental trials. However, salinity significantly affected thermal preference with the shrimp selecting higher temperatures at 10 and 20 PSU when compared to 30 PSU of salinity. Body size had no effect on thermal selection and did not interact with salinity. Temperature preference differed by sex and male shrimp selected significantly higher temperatures at 10 PSU when compared to females. The results show that salinity strongly affects thermal selection in brown shrimp and confirms the strong interrelation of temperature and salinity on seasonal migratory movements that has been previously derived from observations in the field. In the field, however, it remains unclear whether salinity drives thermal selection or whether changes in temperature modify salinity preference.
Root and shoot responses of Taxodium distichum seedlings subjected to saline flooding
Krauss, K.W.; Chambers, J.L.; Allen, J.A.; Luse, B.P.; DeBosier, A.S.
1999-01-01
Variation among progeny of five half-sib family collections of baldcypress (Taxodium distichum) from three freshwater and two brackish-water seed sources subjected to saline flooding was evaluated Mini-rhizotrons (slant tubes) were used to monitor root elongation for a period of 99 days. Salinity level produced significant effects across all baldcypress half-sib families, with root elongation averaging 1594.0, 956.8, and 382.1 mm, respectively, for the 0, 4, and 6 g l-1 treatments. Combined mean root elongation for families from brackish-water seed sources was greater (1236.7 mm) than for families from freshwater seed sources (794.6 mm). Considerable variation occurred at the highest salinity treatment, however, with one freshwater family maintaining more than 28% more root growth than the average of the two brackish-water collections. Hence, results indicate that short-term evaluation of root elongation at these salinity concentrations may not be a reliable method for salt tolerance screening of baldcypress. Species-level effects for height and diameter, which were measured at day 62, were significant for both parameters. Height increment in the control (7.4 cm), for example, was approximately five times greater than height increment in the 6 g l-1 salinity treatment (1.5 cm). Family-level variation was significant only for diameter, which had an incremental range of 0.2 to 1.5 mm across all salinity levels.
Fine-scale variability of isopycnal salinity in the California Current System
NASA Astrophysics Data System (ADS)
Itoh, Sachihiko; Rudnick, Daniel L.
2017-09-01
This paper examines the fine-scale structure and seasonal fluctuations of the isopycnal salinity of the California Current System from 2007 to 2013 using temperature and salinity profiles obtained from a series of underwater glider surveys. The seasonal mean distributions of the spectral power of the isopycnal salinity gradient averaged over submesoscale (12-30 km) and mesoscale (30-60 km) ranges along three survey lines off Monterey Bay, Point Conception, and Dana Point were obtained from 298 transects. The mesoscale and submesoscale variance increased as coastal upwelling caused the isopycnal salinity gradient to steepen. Areas of elevated variance were clearly observed around the salinity front during the summer then spread offshore through the fall and winter. The high fine-scale variances were observed typically above 25.8 kg m-3 and decreased with depth to a minimum at around 26.3 kg m-3. The mean spectral slope of the isopycnal salinity gradient with respect to wavenumber was 0.19 ± 0.27 over the horizontal scale of 12-60 km, and 31%-35% of the spectra had significantly positive slopes. In contrast, the spectral slope over 12-30 km was mostly flat, with mean values of -0.025 ± 0.32. An increase in submesoscale variability accompanying the steepening of the spectral slope was often observed in inshore areas; e.g., off Monterey Bay in winter, where a sharp front developed between the California Current and the California Under Current, and the lower layers of the Southern California Bight, where vigorous interaction between a synoptic current and bottom topography is to be expected.
Freshwater salinization syndrome on a continental scale.
Kaushal, Sujay S; Likens, Gene E; Pace, Michael L; Utz, Ryan M; Haq, Shahan; Gorman, Julia; Grese, Melissa
2018-01-23
Salt pollution and human-accelerated weathering are shifting the chemical composition of major ions in fresh water and increasing salinization and alkalinization across North America. We propose a concept, the freshwater salinization syndrome, which links salinization and alkalinization processes. This syndrome manifests as concurrent trends in specific conductance, pH, alkalinity, and base cations. Although individual trends can vary in strength, changes in salinization and alkalinization have affected 37% and 90%, respectively, of the drainage area of the contiguous United States over the past century. Across 232 United States Geological Survey (USGS) monitoring sites, 66% of stream and river sites showed a statistical increase in pH, which often began decades before acid rain regulations. The syndrome is most prominent in the densely populated eastern and midwestern United States, where salinity and alkalinity have increased most rapidly. The syndrome is caused by salt pollution (e.g., road deicers, irrigation runoff, sewage, potash), accelerated weathering and soil cation exchange, mining and resource extraction, and the presence of easily weathered minerals used in agriculture (lime) and urbanization (concrete). Increasing salts with strong bases and carbonates elevate acid neutralizing capacity and pH, and increasing sodium from salt pollution eventually displaces base cations on soil exchange sites, which further increases pH and alkalinization. Symptoms of the syndrome can include: infrastructure corrosion, contaminant mobilization, and variations in coastal ocean acidification caused by increasingly alkaline river inputs. Unless regulated and managed, the freshwater salinization syndrome can have significant impacts on ecosystem services such as safe drinking water, contaminant retention, and biodiversity. Copyright © 2018 the Author(s). Published by PNAS.
Freshwater salinization syndrome on a continental scale
Likens, Gene E.; Pace, Michael L.; Utz, Ryan M.; Haq, Shahan; Gorman, Julia; Grese, Melissa
2018-01-01
Salt pollution and human-accelerated weathering are shifting the chemical composition of major ions in fresh water and increasing salinization and alkalinization across North America. We propose a concept, the freshwater salinization syndrome, which links salinization and alkalinization processes. This syndrome manifests as concurrent trends in specific conductance, pH, alkalinity, and base cations. Although individual trends can vary in strength, changes in salinization and alkalinization have affected 37% and 90%, respectively, of the drainage area of the contiguous United States over the past century. Across 232 United States Geological Survey (USGS) monitoring sites, 66% of stream and river sites showed a statistical increase in pH, which often began decades before acid rain regulations. The syndrome is most prominent in the densely populated eastern and midwestern United States, where salinity and alkalinity have increased most rapidly. The syndrome is caused by salt pollution (e.g., road deicers, irrigation runoff, sewage, potash), accelerated weathering and soil cation exchange, mining and resource extraction, and the presence of easily weathered minerals used in agriculture (lime) and urbanization (concrete). Increasing salts with strong bases and carbonates elevate acid neutralizing capacity and pH, and increasing sodium from salt pollution eventually displaces base cations on soil exchange sites, which further increases pH and alkalinization. Symptoms of the syndrome can include: infrastructure corrosion, contaminant mobilization, and variations in coastal ocean acidification caused by increasingly alkaline river inputs. Unless regulated and managed, the freshwater salinization syndrome can have significant impacts on ecosystem services such as safe drinking water, contaminant retention, and biodiversity. PMID:29311318
Busev, V M; Semen'kov, P G; Mishchenko, T Ia
1977-01-01
Studies have been made on the dependence of sodium, potassium, magnesium and calcium concentrations of the blood and urine on the salinity of the external milieu in the crab H. sanguineus. Effective regulation of sodium and potasssium balance at low salinities was found. Within the salinity range investigated, magnesium level in the blood is maintained at lower level as compared to that in the environment. At low salinities, regulation of potassium and sodium concentrations in the blood is monitored by extrarenal mechanisms. Uber high salinity conditions, regulation of magnesium and potassium concentrations in the blood is accomplished at the expense of the activity of antennal glands. Calcium concentration in the blood is regulated by extra-renal mechanisms. The antennal glands affect regulation of calcium balance.
NASA Astrophysics Data System (ADS)
IJsseldijk, Lonneke L.; Camphuysen, Kees C. J.; Nauw, Janine J.; Aarts, Geert
2015-09-01
One of the most important factors explaining the distribution and behaviour of coastal marine mammals are tides. Tidal forces drive a large number of primary and secondary processes, such as changes in water depth, salinity, temperature, current velocity and direction. Unravelling which tidal process is the most influential for a certain species is often challenging, due to a lack of observations of all tide related covariates, strong correlation between them, and the elusive nature of most marine organisms which often hampers their detection. In the Marsdiep area, a tidal inlet between the North Sea and the Dutch Wadden Sea, the presence of harbour porpoises (Phocoena phocoena) was studied as a function of tide related covariates. Observations were carried out in early spring from a ferry crossing the inlet on a half hourly basis. Environmental and sightings data were collected by one observer, while an on-board Acoustic Doppler Current Profiler (ADCP) and temperature sensor continuously recorded current velocity profiles and temperature, respectively. Sea surface temperature and salinity were measured at a nearby jetty. Sightings (n = 134) were linked to tidal elevation, geographical position, local depth-averaged current velocity, water temperature (with and without trend correction) and salinity. Variation in sighting rate was best described by salinity, with highest sighting rate at high levels of salinity (> 30 g kg- 1), indicating that porpoises enter the area in bodies of (more saline) North Sea water. Second best variable was time of day, with the highest sighting rate early morning, and decreasing during the day. However, surveys in the morning happened to coincide more often with high water and hence, the apparent time of day effect could be due to collinearity. Most porpoises were present in the northern part of the Marsdiep, particularly during high tide. Tide dependent sighting rates confirmed that porpoises reside in the North Sea, and enter the western Wadden Sea during the flood and leave during ebb. This tidal influx is most likely related to prey availability, which corresponds to other recent studies in this area showing higher fish abundance during high tide. Documenting information on tide related patterns could be used in practice, when e.g. planning anthropogenic activities or assessing critical habitats for this species.
El-Hendawy, Salah E.; Hassan, Wael M.; Al-Suhaibani, Nasser A.; Refay, Yahya; Abdella, Kamel A.
2017-01-01
Field-based trials are crucial for successfully achieving the goals of plant breeding programs aiming to screen and improve the salt tolerance of crop genotypes. In this study, simulated saline field growing conditions were designed using the subsurface water retention technique (SWRT) and three saline irrigation levels (control, 60, and 120 mM NaCl) to accurately appraise the suitability of a set of agro-physiological parameters including shoot biomass, grain yield, leaf water relations, gas exchange, chlorophyll fluorescence, and ion accumulation as screening criteria to establish the salt tolerance of the salt-tolerant (Sakha 93) and salt-sensitive (Sakha 61) wheat cultivars. Shoot dry weight and grain yield per hectare were substantially reduced by salinity, but the reduction was more pronounced in Sakha 61 than in Sakha 93. Increasing salinity stress caused a significant decrease in the net photosynthesis rate and stomatal conductance of both cultivars, although their leaf turgor pressure increased. The accumulation of toxic ions (Na+ and Cl-) was higher in Sakha 61, but the accumulation of essential cations (K+ and Ca2+) was higher in Sakha 93, which could be the reason for the observed maintenance of the higher leaf turgor of both cultivars in the salt treatments. The maximum quantum PSII photochemical efficiency (Fv/Fm) and the PSII quantum yield (ΦPSII) decreased with increasing salinity levels in Sakha 61, but they only started to decline at the moderate salinity condition in Sakha 93. The principle component analysis successfully identified the interrelationships between all parameters. The parameters of leaf water relations and toxic ion concentrations were significantly related to each other and could identify Sakha 61 at mild and moderate salinity levels, and, to a lesser extent, Sakha 93 at the moderate salinity level. Both cultivars under the control treatment and Sakha 93 at the mild salinity level were identified by most of the other parameters. The variability in the angle between the vectors of parameters explained which parameters could be used as individual, interchangeable, or supplementary screening criteria for evaluating wheat salt tolerance under simulated field conditions. PMID:28424718
Marconi, Gianpiero; Pace, Roberta; Traini, Alessandra; Raggi, Lorenzo; Lutts, Stanley; Chiusano, Marialuisa; Guiducci, Marcello; Falcinelli, Mario; Benincasa, Paolo; Albertini, Emidio
2013-01-01
Excessive soil salinity is a major ecological and agronomical problem, the adverse effects of which are becoming a serious issue in regions where saline water is used for irrigation. Plants can employ regulatory strategies, such as DNA methylation, to enable relatively rapid adaptation to new conditions. In this regard, cytosine methylation might play an integral role in the regulation of gene expression at both the transcriptional and post-transcriptional levels. Rapeseed, which is the most important oilseed crop in Europe, is classified as being tolerant of salinity, although cultivars can vary substantially in their levels of tolerance. In this study, the Methylation Sensitive Amplified Polymorphism (MSAP) approach was used to assess the extent of cytosine methylation under salinity stress in salinity-tolerant (Exagone) and salinity-sensitive (Toccata) rapeseed cultivars. Our data show that salinity affected the level of DNA methylation. In particular methylation decreased in Exagone and increased in Toccata. Nineteen DNA fragments showing polymorphisms related to differences in methylation were sequenced. In particular, two of these were highly similar to genes involved in stress responses (Lacerata and trehalose-6-phosphatase synthase S4) and were chosen to further characterization. Bisulfite sequencing and quantitative RT-PCR analysis of selected MSAP loci showed that cytosine methylation changes under salinity as well as gene expression varied. In particular, our data show that salinity stress influences the expression of the two stress-related genes. Moreover, we quantified the level of trehalose in Exagone shoots and found that it was correlated to TPS4 expression and, therefore, to DNA methylation. In conclusion, we found that salinity could induce genome-wide changes in DNA methylation status, and that these changes, when averaged across different genotypes and developmental stages, accounted for 16.8% of the total site-specific methylation differences in the rapeseed genome, as detected by MSAP analysis. PMID:24086583
Stagg, Camille L.; Schoolmaster, Donald R.; Piazza, Sarai C.; Snedden, Gregg; Steyer, Gregory D.; Fischenich, Craig J; McComas, Robert W.
2017-01-01
Above- and belowground production in coastal wetlands are important contributors to carbon accumulation and ecosystem sustainability. As sea level rises, we can expect shifts to more salt-tolerant communities, which may alter these ecosystem functions and services. Although the direct influence of salinity on species-level primary production has been documented, we lack an understanding of the landscape-level response of coastal wetlands to increasing salinity. What are the indirect effects of sea-level rise, i.e., how does primary production vary across a landscape gradient of increasing salinity that incorporates changes in wetland type? This is the first study to measure both above- and belowground production in four wetland types that span an entire coastal gradient from fresh to saline wetlands. We hypothesized that increasing salinity would limit rates of primary production, and saline marshes would have lower rates of above- and belowground production than fresher marshes. However, along the Northern Gulf of Mexico Coast in Louisiana, USA, we found that aboveground production was highest in brackish marshes, compared with fresh, intermediate, and saline marshes, and belowground production was similar among all wetland types along the salinity gradient. Multiple regression analysis indicated that salinity was the only significant predictor of production, and its influence was dependent upon wetland type. We concluded that (1) salinity had a negative effect on production within wetland type, and this relationship was strongest in the fresh marsh (0–2 PSU) and (2) along the overall landscape gradient, production was maintained by mechanisms at the scale of wetland type, which were likely related to plant energetics. Regardless of wetland type, we found that belowground production was significantly greater than aboveground production. Additionally, inter-annual variation, associated with severe drought conditions, was observed exclusively for belowground production, which may be a more sensitive indicator of ecosystem health than aboveground production.
Rangani, Jaykumar; Parida, Asish K.; Panda, Ashok; Kumari, Asha
2016-01-01
Salinity-induced modulations in growth, photosynthetic pigments, relative water content (RWC), lipid peroxidation, photosynthesis, photosystem II efficiency, and changes in activity of various antioxidative enzymes were studied in the halophyte Salvadora persica treated with various levels of salinity (0, 250, 500, 750, and 1000 mM NaCl) to obtain an insight into the salt tolerance ability of this halophyte. Both fresh and dry biomass as well as leaf area (LA) declined at all levels of salinity whereas salinity caused an increase in leaf succulence. A gradual increase was observed in the Na+ content of leaf with increasing salt concentration up to 750 mM NaCl, but at higher salt concentration (1000 mM NaCl), the Na+ content surprisingly dropped down to the level of 250 mM NaCl. The chlorophyll and carotenoid contents of the leaf remained unaffected by salinity. The photosynthetic rate (PN), stomatal conductance (gs), the transpiration rate (E), quantum yield of PSII (ΦPSII), photochemical quenching (qP), and electron transport rate remained unchanged at low salinity (250 to 500 mM NaCl) whereas, significant reduction in these parameters were observed at high salinity (750 to 1000 mM NaCl). The RWC% and water use efficiency (WUE) of leaf remained unaffected by salinity. The salinity had no effect on maximum quantum efficiency of PS II (Fv/Fm) which indicates that PS II is not perturbed by salinity-induced oxidative damage. Analysis of the isoforms of antioxidative enzymes revealed that the leaves of S. persica have two isoforms each of Mn-SOD and Fe-SOD and one isoform of Cu-Zn SOD, three isoforms of POX, two isoforms of APX and one isoform of CAT. There was differential responses in activity and expression of different isoforms of various antioxidative enzymes. The malondialdehyde (MDA) content (a product of lipid peroxidation) of leaf remained unchanged in S. persica treated with various levels of salinity. Our results suggest that the absence of pigment degradation, the reduction of water loss, and the maintenance of WUE and protection of PSII from salinity-induced oxidative damage by the coordinated changes in antioxidative enzymes are important factors responsible for salt tolerance of S. persica. PMID:26904037
NASA Astrophysics Data System (ADS)
Holmes, K. W.; Barrett-Lennard, E. G.; Altman, M.
2011-12-01
Experiments conducted under controlled conditions clearly show that the growth and survival of plants on saltland is affected by both the levels of salinity and waterlogging (or depth to water-table) in the soil. Different plant species thrive under varying combinations of these growth constraints. However in natural settings, short distance spatial variability in soil properties and subtle topographic features often complicate the definition of saline and soil hydrological conditions; additional factors may also overprint the trends identified under controlled conditions, making it difficult to define the physical settings where planting is economically viable. We investigated the establishment and growth of old man saltbush (Atriplex nummularia) in relation to variable soil-landscape conditions across an experimental site in southwestern Australia where the combination of high salinity and occasional seasonal waterlogging ruled out the growth of traditional crops and pastures. Saltbush can be critical supplemental feed in the dry season, providing essential nutrients for sheep in combination with sufficient water and dry feed (hay). We applied a range of modeling approaches including classification and regression trees and generalized linear models to statistically characterize these plant-environment relationships, and extend them spatially using full cover raster covariate datasets. Plant deaths could be consistently predicted (97% correct classification of independent dataset) using a combination of topographic variables, salinity, soil mineralogical information, and depth to the water table. Plant growth patterns were more difficult to predict, particularly after several years of grazing, however variation in plant volume was well-explained with a linear model (r2 = 0.6, P < 0.0001). All types of environmental data were required, supporting the starting hypothesis that saltland pasture success is driven by water movement in the landscape. The final selected covariates for modeling were a digital elevation model and derivatives, soil mineralogy, competitors for water (adjacent trees) and soil salinity (measured with an EM38). Our exploration of strengths and weaknesses of extrapolating simple relationships determined under controlled conditions to the field vindicates the importance of both approaches. Landholders often view the idea of the productive use of saltland with skepticism. The challenge is to use the combined datasets from glasshouse and field experiments to develop information guidelines for landholders that maximize the chances of revegetation success. Water availability, waterlogging, quality of the shallow groundwater, and secondary salinity are dominant processes that impact on agriculture in southwestern Australia. Improving our understanding of their interactions and effect on productivity will help adapt agricultural management to changing environmental conditions in the future.
Liu, Bing-Xiang; Wang, Zhi-Gang; Liang, Hai-Yong; Yang, Min-Sheng
2012-06-01
Taking the Ulmus pumila seedlings from three different habitats (medium-, mild-, and non-saline soils) as test materials, an experiment was conducted to study their salt-tolerance thresholds and physiological characteristic under different levels (0, 2, 4, 6, 8, and 10 g X kg(-1)) of salt stress. With increasing level of the salt stress, the seedlings taken from medium- and mild- saline habitats had a lower increment of leaf membrane permeability, Na+ content, and Na+/K+ but a higher increment of leaf proline, soluble sugar, and K+ contents, and a lower decrement of leaf starch content, net photosynthetic rate, transpiration rate, intercellular CO2 concentration, and stomatic conductance, as compared with the seedlings taken from non-saline habitat. The salt-tolerance thresholds of the seedlings taken from different habitats were in the order of medium- saline habitat (7.76 g X kg(-1)) > mild- saline habitat (7.37 g X kg(-1)) > non-saline habitat (6.95 g X kg(-1)). It was suggested that the U. pumila seedlings in medium- and mild-saline habitats had a stronger adaptability to saline soil environment than the U. pumila seedlings in non-saline soil environment.
Histamine-dependent behavioral response to methamphetamine in 12-month-old male mice
Acevedo, Summer F.; Raber, Jacob
2011-01-01
Methamphetamine (MA) use is a growing problem across the United States. Effects of MA include hyperactivity and increased anxiety. Using a mouse model system, we examined behavioral performance in the open field and elevated zero maze and shock-startle response of 12-month-old wild-type mice injected with MA once (1mg/kg) 30 min prior to behavioral testing. MA treatment resulted in behavioral sensitization in the open field, consistent with studies in younger mice. There was an increased activity in the elevated zero maze and an increased shock-startle response 30 and 60 min post-injection. Since histamine mediates some effects of MA in the brain, we assessed whether 12-month-old mice lacking histidine decarboxylase (Hdc−/−), the enzyme required to synthesize histamine, respond differently to MA than wild-type (Hdc+/+) mice. Compared to saline treatment, acute and repeated MA administration increased activity in the open field and measures of anxiety, though more so in Hdc−/− than Hdc+/+ mice. In the elevated zero maze, opposite effects of MA on activity and measures of anxiety were seen in Hdc+/+ mice. In contrast, MA similarly increased the shock-startle response in Hdc−/− and Hdc+/+ mice, compared to saline-treated genotype-matched mice. These results are similar to those in younger mice suggesting that the effects are not age-dependent. Overall, single or repeated MA treatment causes histamine-dependent changes in 12-month-old mice in the open field and elevated zero-maze, but not in the shock-startle response. PMID:21466792
Gao, Yu; Gui, Qinfang; Jin, Li; Yu, Pan; Wu, Lin; Cao, Liangbin; Wang, Qiang; Duan, Manlin
2017-02-15
Hydrogen-rich saline can selectively scavenge reactive oxygen species (ROS) and protect brain against ischemia reperfusion (I/R) injury. Endoplasmic reticulum stress (ERS) has been implicated in the pathological process of cerebral ischemia. However, very little is known about the role of hydrogen-rich saline in mediating pathophysiological reactions to ERS after I/R injury caused by cardiac arrest. The rats were randomly divided into three groups, sham group (n=30), ischemia/reperfusion group (n=40) and hydrogen-rich saline group (n=40). The rats in experimental groups were subjected to 4min of cardiac arrest and followed by resuscitation. Then they were randomized to receive 5ml/kg of either hydrogen-rich saline or normal saline. Hydrogen-rich saline significantly improves survival rate and neurological function. The beneficial effects of hydrogen-rich saline were associated with decreased levels of oxidative products, as well as the increased levels of antioxidant enzymes. Furthermore, the protective effects of hydrogen-rich saline were accompanied by the increased activity of glucose-regulated protein 78 (GRP78), the decreased activity of cysteinyl aspartate specific proteinase-12 (caspase-12) and C/EBP homologous protein (CHOP). Hydrogen-rich saline attenuates brain I/R injury may through inhibiting hippocampus ERS after cardiac arrest in rats. Copyright © 2017 Elsevier B.V. All rights reserved.
Scottish saline lagoons: Impacts and challenges of climate change
NASA Astrophysics Data System (ADS)
Angus, Stewart
2017-11-01
The majority of Scotland's saline lagoons are located on the low-lying coastlines of the Western Isles and the northern archipelagos of Orkney and Shetland, where recorded annual relative sea level rise rates are among the highest in Scotland. The sediment-impounded lagoons of Orkney and Shetland will either lose their impoundment and become incorporated in marine coastal waters, or become increasingly saline, as relative sea levels rise. The rock-basin lagoons of the Western Isles will retain their restricted exchange with the sea but will also become more saline with rising sea level. Specialist lagoonal organisms tend to have wide salinity tolerances but may succumb to competition from marine counterparts. In all areas, there are sufficient fresh-water inland water bodies with potential to be captured as lagoons to compensate for loss of extent and number, but the specialist lagoon biota tend to have limited dispersal powers. It is thus possible that they will be unable to transfer to their analogue sites before existing lagoons become fully marine, giving conservation managers the problem of deciding on management options: leave natural processes to operate without interference, manage the saline inflow to maintain the current salinity regime, or translocate lagoon organisms perceived as threatened by rising salinities. Timing of conversion and capture is unpredictable due to local topography and complications caused by variable stratification.
Xiao, Meng; Sun, Shan-Shan; Zhang, Zhong-Zhi; Wang, Jun-Ming; Qiu, Long-Wei; Sun, Hua-Yang; Song, Zhao-Zheng; Zhang, Bei-Yu; Gao, De-Li; Zhang, Guang-Qing; Wu, Wei-Min
2016-01-01
The community diversities of two oil reservoirs with low permeability of 1.81 × 10−3 and 2.29 × 10−3 μm2 in Changqing, China, were investigated using a high throughput sequencing technique to analyze the influence of biostimulation with a nutrient activator on the bacterial communities. These two blocks differed significantly in salinity (average 17,500 vs 40,900 mg/L). A core simulation test was used to evaluate the effectiveness of indigenous microbial-enhanced oil recovery (MEOR). The results indicated that in the two high salinity oil reservoirs, one reservoir having relatively lower salinity level and a narrow salinity range had higher bacterial and phylogenetic diversity. The addition of the nutrient activator increased the diversity of the bacterial community structure and the diversity differences between the two blocks. The results of the core simulation test showed that the bacterial community in the reservoir with a salinity level of 17,500 mg/L did not show significant higher MEOR efficiency compared with the reservoir with 40,900 mg/L i.e. MEOR efficiency of 8.12% vs 6.56% (test p = 0.291 > 0.05). Therefore, salinity levels affected the bacterial diversities in the two low permeability oil blocks remarkably. But the influence of salinity for the MEOR recovery was slightly. PMID:26786765
Hakim, M A; Juraimi, Abdul Shukor; Hanafi, M M; Rafii, Mohd Y; Ismail, Mohd Razi; Karim, S M Rezaul; Kausar, H
2015-11-01
The pot experiment was conducted to select appropriate integrated weed management method in rice under different salinity levels (0, 4 and 8 dS m(-1)). All the parameters including rice and weed measured were significantly influenced by weed control treatments at all salinity levels. Treatments including weed-free condition, Pretilachlor @0.375 kg ai ha(-1) + hand weeding, Propanil + Thiobencarb @ 0.9 kg ai ha(-1) and 1.8 kg ai ha(-1)+ hand weeding performed better under all salinity levels. Pretilachlor @ 0.375 kg ai ha(-1) with one round of hand weeding and propanil + thiobencarb 0.9 kg ai ha(-1) + 1.8 kg ai ha(-1) with one round of hand weeding were comparable to weed-free yields, and were superior to other treatments under salinity condition. Considering all the parameters, pretilachlor @ 0.375 kg ai ha(-1) + one round of hand weeding (at 65 DAT), propanil + thiobencarb 0.9 kg ai ha(-1) +1.8 kg ai ha(-1) + one round of hand weeding (at 65 DAT) gave the most effective control of weeds in rice under saline environments.
Bianchini, Adalto; Lauer, Mariana Machado; Nery, Luiz Eduardo Maia; Colares, Elton Pinto; Monserrat, José María; Dos Santos Filho, Euclydes Antônio
2008-11-01
Neohelice granulata (Chasmagnathus granulatus) is an intertidal crab species living in salt marshes from estuaries and lagoons along the Atlantic coast of South America. It is a key species in these environments because it is responsible for energy transfer from producers to consumers. In order to deal with the extremely marked environmental salinity changes occurring in salt marshes, N. granulata shows important and interesting structural, biochemical, and physiological adaptations at the gills level. These adaptations characterize this crab as a euryhaline species, tolerating environmental salinities ranging from very diluted media to concentrated seawater. These characteristics had led to its use as an animal model to study estuarine adaptations in crustaceans. Therefore, the present review focuses on the influence of environmental salinity on N. granulata responses at the ecological, organismic and molecular levels. Aspects covered include salinity tolerance, osmo- and ionoregulatory patterns, morphological and structural adaptations at the gills, and mechanisms of ion transport and their regulation at the gills level during environmental salinity acclimation. Finally, this review compiles information on the effects of some environmental pollutants on iono- and osmoregulatory adaptations showed by N. granulata.
Rice, Karen C.; Bennett, Mark; Shen, Jian
2011-01-01
As a result of climate change and variability, sea level is rising throughout the world, but the rate along the east coast of the United States is higher than the global mean rate. The U.S. Geological Survey, in cooperation with the City of Newport News, Virginia, conducted a study to evaluate the effects of possible future sea-level rise on the salinity front in two tributaries to Chesapeake Bay, the York River, and the Chickahominy/James River estuaries. Numerical modeling was used to represent sea-level rise and the resulting hydrologic effects. Estuarine models for the two tributaries were developed and model simulations were made by use of the Three-Dimensional Hydrodynamic-Eutrophication Model (HEM-3D), developed by the Virginia Institute of Marine Science. HEM-3D was used to simulate tides, tidal currents, and salinity for Chesapeake Bay, the York River and the Chickahominy/James River. The three sea-level rise scenarios that were evaluated showed an increase of 30, 50, and 100 centimeters (cm). Model results for both estuaries indicated that high freshwater river flow was effective in pushing the salinity back toward Chesapeake Bay. Model results indicated that increases in mean salinity will greatly alter the existing water-quality gradients between brackish water and freshwater. This will be particularly important for the freshwater part of the Chickahominy River, where a drinking-water-supply intake for the City of Newport News is located. Significant changes in the salinity gradients for the York River and Chickahominy/James River estuaries were predicted for the three sea-level rise scenarios. When a 50-cm sea-level rise scenario on the York River during a typical year (2005) was used, the model simulation showed a salinity of 15 parts per thousand (ppt) at river kilometer (km) 39. During a dry year (2002), the same salinity (15 ppt) was simulated at river km 45, which means that saltwater was shown to migrate 6 km farther upstream during a dry year than a typical year. The same was true of the Chickahominy River for a 50-cm sea-level rise scenario but to a greater extent; a salinity of 4 ppt was simulated at river km 13 during a typical year and at river km 28 during a dry year, indicating that saltwater migrated 15 km farther upstream during a dry year. Near a drinking-water intake on the Chickahominy River, for a dry year, salinity is predicted to more than double for all three sea-level rise scenarios, relative to a typical year. During a typical year at this location, salinity is predicted to increase to 0.006, 0.07, and more than 2 ppt for the 30-, 50-, and 100-cm rise scenarios, respectively.
Industrial-scale storage of CO2 in saline sedimentary basins will cause zones of elevated pressure, larger than the CO2 plume itself. If permeable conduits (e.g., leaking wells) exist between the injection reservoir and overlying shallow aquifers, brine could be pushed upwards al...
Chrysargyris, Antonios; Michailidi, Evgenia; Tzortzakis, Nikos
2018-01-01
Saline water has been proposed as a solution to partially cover plant water demands due to scarcity of irrigation water in hot arid areas. Lavender (Lavandula angustifolia Mill.) plants were grown hydroponically under salinity (0–25–50–100 mM NaCl). The overcome of salinity stress was examined by K, Zn, and Si foliar application for the plant physiological and biochemical characteristics. The present study indicated that high (100 mM NaCl) salinity decreased plant growth, content of phenolics and antioxidant status and essential oil (EO) yield, while low-moderate salinity levels maintained the volatile oil profile in lavender. The integrated foliar application of K and Zn lighten the presumable detrimental effects of salinity in terms of fresh biomass, antioxidant capacity, and EO yield. Moderate salinity stress along with balanced concentration of K though foliar application changed the primary metabolites pathways in favor of major volatile oil constituents biosynthesis and therefore lavender plant has the potential for cultivation under prevalent semi-saline conditions. Zn and Si application, had lesser effects on the content of EO constituents, even though altered salinity induced changings. Our results have demonstrated that lavender growth/development and EO production may be affected by saline levels, whereas mechanisms for alteration of induced stress are of great significance considering the importance of the oil composition, as well. PMID:29731759