scholarly journals A Study of the Impact of Different Flow Velocities and Light Colors at the Entrance of a Fish Collection System on the Upstream Swimming Behavior of Juvenile Grass Carp

Water ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 322 ◽  
Author(s):  
Xiangpeng Mu ◽  
Wanyue Zhen ◽  
Xiang Li ◽  
Ping Cao ◽  
Li Gong ◽  
...  
Keyword(s):  
Flow Velocity ◽  
Physical Model ◽  
Avoidance Behavior ◽  
Grass Carp ◽  
Collection System ◽  
Optimal Flow ◽  
Avoidance Behaviors ◽  
Fish Collection ◽  
Approach Avoidance ◽  
Flow Velocities

When designing a fish collection system for fishpass facilities, considering the approach–avoidance behavior of fish under different flow velocities and light colors, is essential to ensure a good fishpass efficiency. In this study, a generalized physical model for a fish collection system entrance, including the fish collection system channel, the fish luring channel, and the mainstream channel was designed. Grass carp, a representative fish of “four major Chinese carps”, was selected as the research object, and the approach–avoidance behavior of 660 juvenile grass carps (8–12cm), under different flow velocity and light color at a water temperature of 28 ± 1 °C, were investigated. Three general indicators that reflect the fish-luring ability of a fish collection system were proposed, including the optimal flow velocity at the fish collection system entrance, the optimal ratio between the flow velocities at the entrances of the fish luring channel and the fish collection system channel, and the optimal light colors for approach–avoidance behaviors of the fish. Results indicate that (1) there was an optimal flow velocity (approximately 0.3 m/s) at the fish collection system entrance; (2) there existed an optimal ratio (approximately 2.3:1) between the flow velocities at the entrances of the fish luring channel and the fish collection system channel; (3) there were different approach–avoidance behaviors of the fish to various light colors, and the percentages of successful migration of the juvenile grass carps were 0.4%, 0.57%, 0.88%, and 1.43% of that obtained under natural light, when red, white, green, and blue light were used, respectively, at the fish collection system entrance, indicating that the juvenile grass carps would avoid the red light while approaching the blue light. The three proposed general indicators are the keys in the design of a fish collection system entrance, for successful migration of grass carps. The generalized physical model and the experimental devices and methods will provide important references for studying a fish collection system entrance for other fish species.

Intraoperative transesophageal assessment of coronary artery flow can predict 5 type myocardial infarction

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
A Zagatina ◽  
M Novikov ◽  
N Zhuravskaya ◽  
V Balakhonov ◽  
S Efremov ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Cardiac Surgery ◽  
Coronary Artery ◽  
Flow Velocity ◽  
Coronary Flow ◽  
Index Number ◽  
Left Main ◽  
Coronary Flow Velocity ◽  
Before And After ◽  
Flow Velocities

Abstract Background Stenosis of a coronary artery results in an increase in flow velocity in the pathologic segment. Effective grafting should decrease the stenotic native coronary velocity according to hemodynamic law. The range of decreased velocity before and after cardiac surgery can hypothetically reflect the effectiveness of a graft. The aim of the study is to determine if measuring coronary flow velocity changes during coronary artery bypass grafting (CABG) can predict intraoperative myocardial infarction. Methods One hundred sixty-six (166) consecutive patients (121 men, 64±9 years old) referred for cardiac surgery, were prospectively included in the study. A standard basic perioperative transesophageal echocardiography (TEE) examination was performed with additional scans of the left main, left anterior descending (LAD), and circumflex (LCx) arteries' proximal segments. Measurements of coronary flow velocities were performed before and after grafting in the same sites of the arteries. The maximal value of cardiac troponin I (cTnI) after CABG and the additive criteria were accounted for in the analysis as it is described in the expert consensus document for Type 5 myocardial infarction (MI) definition. Results One hundred sixty-three patients (98%) had arterial hypertension, 28 patients (17%) had diabetes mellitus, 35 patients (21%) were currently smokers. The feasibility of coronary flow assessment during cardiac operations was 95%. Before grafting, the mean velocity in the left main artery was 91±49 cm/s, in LAD 101±35 cm/s, and in LCx 117±49 cm/s. There was a significant correlation between changes in coronary flow velocities during operation and the value of cTnI (R=0.34, p<0.0001). Ten patients met the criteria for Type 5 MI. There were no differences in age, body mass index, number of coronary arteries with stenoses, frequency of prior MI, ejection fraction or coronary flow velocity before surgery in patients with and without Type 5 MI. The group of patients with Type 5 MI had an increase in native artery velocities during surgery in comparison with patients without MI, who had a significant decrease in coronary flow velocity after grafting (30±48 vs. −10±30 cm/s; p<0.0006). Increases in native coronary velocities greater than 3 cm/s predicted Type 5 MI with 81% accuracy (sensitivity 88%, specificity 70%). Conclusion Coronary flow velocity assessment during cardiac surgery could predict an elevation of cardiac troponins and Type 5 MI. Funding Acknowledgement Type of funding source: None

Unidirectional to bidirectional subtidal sandwaves influenced by gradually decreasing steady flow velocity

1997 ◽  
Vol 134 (4) ◽  
pp. 557-561
Author(s):  
KATSUHIRO NAKAYAMA
Keyword(s):  
Grain Size ◽  
Flow Velocity ◽  
Steady Flow ◽  
Periodic Flow ◽  
Southwest Japan ◽  
Unit Thickness ◽  
Flow Components ◽  
Flow Velocities

Miocene subtidal sandwave deposits in southwest Japan were influenced by periodic flow and steady flow. The sandwave deposits can be divided into five units, based on lithofacies and thickness. In order of accretion, unit 1 consists of unidirectional sand bedforms without mud drapes, unit 2 of unidirectional sand bedforms with thin, discontinuous mud drapes, unit 3 of bidirectional sand bedforms with thin continuous mud drapes, and units 4 and 5 of relatively thinner and smaller bidirectional sand bedforms with continuous mud drapes. The thickness of units 1 to 3 increase progressively to 2.6 m, and units 4 to 5 subsequently decrease from 2.0 to 1.0 m. Variations between the units are due to differing combinations of periodic and steady flow velocities. Palaeoflow velocity is estimated from grain size and unit thickness. Depth-mean velocities of steady flow components gradually decrease from 0.72 ms−1 to 0.16 ms−1 with unit accumulation.

scholarly journals The effects of cortisol administration on approach–avoidance behavior: An event-related potential study

2007 ◽  
Vol 76 (3) ◽  
pp. 135-146 ◽  
Author(s):  
Jacobien M. van Peer ◽  
Karin Roelofs ◽  
Mark Rotteveel ◽  
J. Gert van Dijk ◽  
Philip Spinhoven ◽  
...  
Keyword(s):  
Avoidance Behavior ◽  
Event Related Potential ◽  
Potential Study ◽  
Approach Avoidance

scholarly journals Ice flow velocities over Vostok Subglacial Lake, East Antarctica, determined by 10 years of GNSS observations

2013 ◽  
Vol 59 (214) ◽  
pp. 315-326 ◽  
Author(s):  
A. Richter ◽  
D.V. Fedorov ◽  
M. Fritsche ◽  
S.V. Popov ◽  
V.Ya. Lipenkov ◽  
...  
Keyword(s):  
Flow Velocity ◽  
East Antarctica ◽  
Global Navigation Satellite Systems ◽  
Steady Increase ◽  
Lake Area ◽  
Ice Flow ◽  
Satellite Systems ◽  
Subglacial Lake ◽  
Gnss Observations ◽  
Flow Velocities

AbstractRepeated Global Navigation Satellite Systems (GNSS) observations were carried out at 50 surface markers in the Vostok Subglacial Lake (East Antarctica) region between 2001 and 2011. The horizontal ice flow velocity vectors were derived with accuracies of 1 cm a−1 and 0.5°, representing the first reliable information on ice flow kinematics in the northern part of the lake. Within the lake area, ice flow velocities do not exceed 2 m a−1. The ice flow azimuth is southeast in the southern part of the lake and turns gradually to east-northeast in the northern part. In the northern part, as the ice flow enters the lake at the western shore, the velocity decreases towards the central lake axis, then increases slightly past the central axis. In the southern part, a continued acceleration is observed from the central lake axis across the downstream grounding line. Based on the observed flow velocity vectors and ice thickness data, mean surface accumulation rates are inferred for four surface segments between Ridge B and Vostok Subglacial Lake and show a steady increase towards the north.

scholarly journals A Study of Sedimentation at the River Estuary on the Change of Reservoir Storage

2018 ◽  
Vol 31 ◽  
pp. 03001 ◽  
Author(s):  
Iskahar ◽  
Suripin ◽  
Isdiyana
Keyword(s):  
Flow Velocity ◽  
Water Level ◽  
Physical Model ◽  
River Estuary ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Sedimentation Pattern ◽  
Cross Sectional ◽  
Channel Angle ◽  
Reservoir Storage

Estuary of the river that leads to the reservoir has characteristics include: relatively flat, there is a change in the increase of wet cross-sectional area and backwater. The backwater will cause the flow velocity to be reduced, so that the grains of sediment with a certain diameter carried by the flow will settle in the estuary of the river. The purpose of this research is to know the distribution and sedimentation pattern at the river estuary that leads to the reservoir with the change of water level in the reservoir storage, so the solution can be found to remove / reduce sediment before entering the reservoir. The method used is the experimental, by making the physical model of the river estuary leading to the reservoir. This study expects a solution to reduce sedimentation, so that sedimentation can be removed / minimized before entering the reservoir. This research tries to apply bypass channel to reduce the sedimentation at the river estuary. Bypass channels can be applied to overcome sedimentation at the river estuary, but in order for the sediment to be removed optimally, it is necessary to modify the mouth of bypass channel and channel angle.

scholarly journals Fronto-striatal projections regulate approach-avoidance conflict

2020 ◽  
Author(s):  
Adrienne C. Loewke ◽  
Adelaide R. Minerva ◽  
Alexandra B. Nelson ◽  
Anatol C. Kreitzer ◽  
Lisa A. Gunaydin
Keyword(s):  
Anxiety Disorders ◽  
Avoidance Behavior ◽  
D1 Receptor ◽  
Projection Neurons ◽  
Medium Spiny Neurons ◽  
Neural Pathways ◽  
Spiny Neurons ◽  
Striatal Projection Neurons ◽  
Neural Computations ◽  
Approach Avoidance

ABSTRACTThe dorsomedial prefrontal cortex (dmPFC) has been linked to approach-avoidance behavior and decision-making under conflict, key neural computations thought to be altered in anxiety disorders. However, the heterogeneity of efferent prefrontal projections has obscured identification of the specific top-down neural pathways regulating these anxiety-related behaviors. While the dmPFC-amygdala circuit has long been implicated in controlling reflexive fear responses, recent work suggests that this circuit is less important for avoidance behavior. We hypothesized that dmPFC neurons projecting to the dorsomedial striatum (DMS) represent a subset of prefrontal neurons that robustly encode and drive approach-avoidance behavior. Using fiber photometry recording during the elevated zero maze (EZM) task, we show heightened neural activity in prefrontal and fronto-striatal projection neurons, but not fronto-amydalar projection neurons, during exploration of the anxiogenic open arms of the maze. Additionally, through pathway-specific optogenetics we demonstrate that this fronto-striatal projection preferentially excites postsynaptic D1 receptor-expressing medium spiny neurons in the DMS and bidirectionally controls avoidance behavior. We conclude that this striatal-projecting subpopulation of prefrontal neurons regulates approach-avoidance conflict, supporting a model for prefrontal control of defensive behavior in which the dmPFC-amygdala projection controls reflexive fear behavior and the dmPFC-striatum projection controls anxious avoidance behavior. Our findings identify this fronto-striatal circuit as a valuable therapeutic target for developing interventions to alleviate excessive avoidance behavior in anxiety disorders.

Does Approach-Avoidance Behavior in Response to Ambiguous Cues Reflect Depressive Interpretation Bias? Related but Distinct

2020 ◽  
Vol 44 (6) ◽  
pp. 1091-1105
Author(s):  
Xiao-Xiao Lin ◽  
Shang-Wen Si ◽  
Rui-Rui Gao ◽  
Ya-Bin Sun ◽  
Yu-Zheng Wang ◽  
...  
Keyword(s):  
Avoidance Behavior ◽  
Interpretation Bias ◽  
Approach Avoidance

Blunt impact as deterrent: human approach-avoidance behaviors and other stress responses studied within a paintball gaming context

2006 ◽  
Author(s):  
Kenneth R. Short ◽  
Michael T. Bergen ◽  
Robert M. DeMarco ◽  
Florence B. Chua ◽  
Richard J. Servatius
Keyword(s):  
Stress Responses ◽  
Blunt Impact ◽  
Avoidance Behaviors ◽  
Approach Avoidance
Sign in / Sign up

Export Citation Format

Share Document