scholarly journals Short-term exposure to elevated suspended sediment increases oxygen uptake of gilled larval Eastern Hellbender salamanders (Cryptobranchus alleganiensis)

2021 ◽  
Author(s):  
Shem Unger ◽  
Reuben R Goforth ◽  
Olin E Rhodes ◽  
Thomas Floyd
Keyword(s):  
Oxygen Uptake ◽  
Suspended Sediment ◽  
Suspended Sediments ◽  
Freshwater Ecosystems ◽  
Life History Stage ◽  
Low Oxygen ◽  
Short Term ◽  
Cryptobranchus Alleganiensis ◽  
Short Term Exposure ◽  
Rocking Behavior

Freshwater ecosystems are increasingly impacted by anthropogenic elevated levels of suspended sediment that may negatively affect aquatic organisms, including salamanders. While increasing fine sediment in streams has been suggested as a reason for population declines, to date no study has empirically assessed the effect of suspended sediment on gilled larval Eastern Hellbenders (Cryptobranchus alleganiensis Daudin, 1803), a critical life history stage and species of conservation concern. We used custom respirometers to elucidate effects of suspended sediments on larval Hellbender oxygen uptake in trials conducted in situ in Georgia streams. Mean oxygen uptake increased and was significantly higher in trials when larval salamanders were exposed to suspended sediment (mean = 5.06 O2 mg/L, 800 mg/L sediment treatment vs 2.25 O2 mg/L, 0.00 mg/L sediment control). This may indicate elevated physiological stress in response to short term exposure to suspended sediments. Qualitatively, individuals in both groups exhibited rocking behavior in response to low oxygen (hypoxia), albeit at different frequencies (sediment exposure = 7.6 rocks per minute and control = 2.1 rocks per minute). Larval salamanders may be able to temporarily compensate for low oxygen through increased rocking behavior when high suspended sediment loads are present, with future respirometry research needed.

scholarly journals The endemic and endangered Maugean Skate (Zearaja maugeana) exhibits short-term severe hypoxia tolerance

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Andrea J Morash ◽  
Jeremy M Lyle ◽  
Suzanne Currie ◽  
Justin D Bell ◽  
Kilian M Stehfest ◽  
...  
Keyword(s):  
Environmental Variability ◽  
Cellular Stress Response ◽  
Hypoxia Tolerance ◽  
Conservation Strategies ◽  
Low Oxygen ◽  
Short Term ◽  
Environmental Challenges ◽  
Preferred Habitat ◽  
Short Term Exposure ◽  
Dissolved O2

Abstract The endangered and range-restricted Maugean skate (Zearaja maugeana) is subjected to large environmental variability coupled with anthropogenic stressors in its endemic habitat, Macquarie Harbour, Tasmania. However, little is known about the basic biology/physiology of this skate, or how it may respond to future environmental challenges predicted from climate change and/or increases in human activities such as aquaculture. These skate live at a preferred depth of 5–15 m where the dissolved oxygen (DO) levels are moderate (~55% air saturation), but can be found in areas of the Harbour where DO can range from 100% saturation to anoxia. Given that the water at their preferred depth is already hypoxic, we sought to investigate their response to further decreases in DO that may arise from potential increases in anthropogenic stress. We measured oxygen consumption, haematological parameters, tissue–enzyme capacity and heat shock protein (HSP) levels in skate exposed to 55% dissolved O2 saturation (control) and 20% dissolved O2 saturation (hypoxic) for 48 h. We conclude that the Maugean skate appears to be an oxyconformer, with a decrease in the rate of O2 consumption with increasing hypoxia. Increases in blood glucose and lactate at 20% O2 suggest that skate are relying more on anaerobic metabolism to tolerate periods of very low oxygen. Despite these metabolic shifts, there was no difference in HSP70 levels between groups, suggesting this short-term exposure did not elicit a cellular stress response. The metabolic state of the skate suggests that low oxygen stress for longer periods of time (i.e. >48 h) may not be tolerable and could potentially result in loss of habitat or shifts in their preferred habitat. Given its endemic distribution and limited life-history information, it will be critical to understand its tolerance to environmental challenges to create robust conservation strategies.

Changes in Territorial, Gill-flaring, and Feeding Behavior in Juvenile Coho Salmon (Oncorhynchus kisutch) following Short-term Pulses of Suspended Sediment

1985 ◽  
Vol 42 (8) ◽  
pp. 1410-1417 ◽  
Author(s):  
L. Berg ◽  
T. G. Northcote
Keyword(s):  
Feeding Behavior ◽  
Suspended Sediment ◽  
Brine Shrimp ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Turbid Water ◽  
Short Term ◽  
Dominance Hierarchies ◽  
Short Term Exposure ◽  
Laboratory Stream

The territorial, gill-flaring, and feeding behavior of juvenile coho salmon (Oncorhynchus kisutch) in a laboratory stream was disrupted by short-term exposure to suspended sediment pulses. At the higher turbidities tested (30 and 60 nephelometric turbidity units (NTU)), dominance hierarchies broke down, territories were not defended, and gill flaring occurred more frequently. Only after return to lower turbidities (0–20 NTU) was social organization reestablished. The reaction distance of the fish to adult brine shrimp decreased significantly in turbid water (30 and 60 NTU) as did capture success per strike and the percentage of prey ingested. Implications of these behavioral modifications suggest that the fitness of salmonid populations exposed to short-term pulses of suspended sediment may be impaired.

scholarly journals Short-Term Exposure of Multipotent Stromal Cells to Low Oxygen Increases Their Expression of CX3CR1 and CXCR4 and Their Engraftment In Vivo

PLoS ONE ◽  
2007 ◽  
Vol 2 (5) ◽  
pp. e416 ◽  
Author(s):  
Shih-Chieh Hung ◽  
Radhika R. Pochampally ◽  
Shu-Ching Hsu ◽  
Cecelia Sanchez ◽  
Sy-Chi Chen ◽  
...  
Keyword(s):  
Stromal Cells ◽  
Multipotent Stromal Cells ◽  
Low Oxygen ◽  
Short Term ◽  
Short Term Exposure

scholarly journals Suspended sediment load prediction using long short-term memory neural network

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nouar AlDahoul ◽  
Yusuf Essam ◽  
Pavitra Kumar ◽  
Ali Najah Ahmed ◽  
Mohsen Sherif ◽  
...  
Keyword(s):  
Neural Network ◽  
Suspended Sediment ◽  
Short Term Memory ◽  
Suspended Sediments ◽  
Gradient Boosting ◽  
Short Term ◽  
Discharge Data ◽  
Term Memory ◽  
Extreme Gradient Boosting ◽  
Long Short Term Memory

AbstractRivers carry suspended sediments along with their flow. These sediments deposit at different places depending on the discharge and course of the river. However, the deposition of these sediments impacts environmental health, agricultural activities, and portable water sources. Deposition of suspended sediments reduces the flow area, thus affecting the movement of aquatic lives and ultimately leading to the change of river course. Thus, the data of suspended sediments and their variation is crucial information for various authorities. Various authorities require the forecasted data of suspended sediments in the river to operate various hydraulic structures properly. Usually, the prediction of suspended sediment concentration (SSC) is challenging due to various factors, including site-related data, site-related modelling, lack of multiple observed factors used for prediction, and pattern complexity.Therefore, to address previous problems, this study proposes a Long Short Term Memory model to predict suspended sediments in Malaysia's Johor River utilizing only one observed factor, including discharge data. The data was collected for the period of 1988–1998. Four different models were tested, in this study, for the prediction of suspended sediments, which are: ElasticNet Linear Regression (L.R.), Multi-Layer Perceptron (MLP) neural network, Extreme Gradient Boosting, and Long Short-Term Memory. Predictions were analysed based on four different scenarios such as daily, weekly, 10-daily, and monthly. Performance evaluation stated that Long Short-Term Memory outperformed other models with the regression values of 92.01%, 96.56%, 96.71%, and 99.45% daily, weekly, 10-days, and monthly scenarios, respectively.

scholarly journals Human engineered meniscus transcriptome after short-term combined hypoxia and dynamic compression

2021 ◽  
Vol 12 ◽  
pp. 204173142199084
Author(s):  
Alexander RA Szojka ◽  
Rita de Cássia Marqueti ◽  
David Xinzheyang Li ◽  
Clayton W Molter ◽  
Yan Liang ◽  
...  
Keyword(s):  
Expression Profile ◽  
Hyaline Cartilage ◽  
Dynamic Compression ◽  
Combined Treatment ◽  
Collagen Scaffold ◽  
Matrix Remodeling ◽  
Low Oxygen ◽  
Short Term ◽  
Meniscus Tissue ◽  
Short Term Exposure

This study investigates the transcriptome response of meniscus fibrochondrocytes (MFCs) to the low oxygen and mechanical loading signals experienced in the knee joint using a model system. We hypothesized that short term exposure to the combined treatment would promote a matrix-forming phenotype supportive of inner meniscus tissue formation. Human MFCs on a collagen scaffold were stimulated to form fibrocartilage over 6 weeks under normoxic (NRX, 20% O2) conditions with supplemented TGF-β3. Tissues experienced a delayed 24h hypoxia treatment (HYP, 3% O2) and then 5 min of dynamic compression (DC) between 30 and 40% strain. Delayed HYP induced an anabolic and anti-catabolic expression profile for hyaline cartilage matrix markers, while DC induced an inflammatory matrix remodeling response along with upregulation of both SOX9 and COL1A1. There were 41 genes regulated by both HYP and DC. Overall, the combined treatment supported a unique gene expression profile favouring the hyaline cartilage aspect of inner meniscus matrix and matrix remodeling.

scholarly journals Effects of Short-term Exposure to Low Oxygen Atmospheres on Phsyiological Responses of Sweetpotato Roots

2007 ◽  
Vol 76 (3) ◽  
pp. 258-265 ◽  
Author(s):  
Yoshihiro Imahori ◽  
Izumi Kishioka ◽  
Kazuko Uemura ◽  
Eiichi Makita ◽  
Hitomi Fujiwara ◽  
...  
Keyword(s):  
Low Oxygen ◽  
Short Term ◽  
Short Term Exposure

The Effect of Dimethyl Sulfoxide on In Vitro Platelet Function

1976 ◽  
Vol 36 (01) ◽  
pp. 221-229 ◽  
Author(s):  
Charles A. Schiffer ◽  
Caroline L. Whitaker ◽  
Morton Schmukler ◽  
Joseph Aisner ◽  
Steven L. Hilbert
Keyword(s):  
Platelet Count ◽  
Platelet Aggregation ◽  
Dimethyl Sulfoxide ◽  
Platelet Function ◽  
Platelet Volume ◽  
Short Term ◽  
Platelet Factor ◽  
Short Term Exposure ◽  
Structural Abnormalities

SummaryAlthough dimethyl sulfoxide (DMSO) has been used extensively as a cryopreservative for platelets there are few studies dealing with the effect of DMSO on platelet function. Using techniques similar to those employed in platelet cryopreservation platelets were incubated with final concentrations of 2-10% DMSO at 25° C. After exposure to 5 and 10% DMSO platelets remained discoid and electron micrographs revealed no structural abnormalities. There was no significant change in platelet count. In terms of injury to platelet membranes, there was no increased availability of platelet factor-3 or leakage of nucleotides, 5 hydroxytryptamine (5HT) or glycosidases with final DMSO concentrations of 2.5, 5 and 10% DMSO. Thrombin stimulated nucleotide and 5HT release was reduced by 10% DMSO. Impairment of thrombin induced glycosidase release was noted at lower DMSO concentrations and was dose related. Similarly, aggregation to ADP was progressively impaired at DMSO concentrations from 1-5% and was dose related. After the platelets exposed to DMSO were washed, however, aggregation and release returned to control values. Platelet aggregation by epinephrine was also inhibited by DMSO and this could not be corrected by washing the platelets. DMSO-plasma solutions are hypertonic but only minimal increases in platelet volume (at 10% DMSO) could be detected. Shrinkage of platelets was seen with hypertonic solutions of sodium chloride or sucrose suggesting that the rapid transmembrane passage of DMSO prevented significant shifts of water. These studies demonstrate that there are minimal irreversible alterations in in vitro platelet function after short-term exposure to DMSO.

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