Diel Feeding and Positioning Periodicity of a Grazing Mayfly in a Trout Stream and a Fishless Stream

1994 ◽  
Vol 51 (2) ◽  
pp. 450-459 ◽  
Author(s):  
Cathy A. Cowan ◽  
Barbara L. Peckarsky
Keyword(s):  
Fish Predation ◽  
Third Order ◽  
Nocturnal Feeding ◽  
Western Colorado ◽  
Baetis Bicaudatus ◽  
Feeding Periodicity ◽  
Gut Fullness ◽  
Flow Through ◽  
Transplant Experiments

We studied the feeding and positioning periodicity on natural substrates of the overwintering and fast-growing summer generations of a grazing mayfly, Baetis bicaudatus, in a third-order trout stream and a fishless, first-order tributary in western Colorado. At 4-h intervals over 24-h, we recorded the number of Baetis on stone tops in flow-through enclosures in situ and in streamside circular flow-through chambers. We determined the feeding periodicity of Baetis using abundance of plant pigments as an index of gut fullness. Baetis were nocturnal in the trout stream; more animals were found on stone tops and guts were fuller at night, suggesting that individuals came to stone tops to feed during darkness. However, Baetis from the fishless stream were either aperiodic or weakly nocturnal. We tested the hypothesis that nocturnal feeding by Baetis is a response to the presence of visually feeding trout by conducting transplant experiments in the circular streams. After 24 h, Baetis transferred from the trout stream to fishless water remained strongly nocturnal, while Baetis transferred from the fishless stream to trout water became significantly more nocturnal, suggesting that the risk of fish predation outweighs the benefits of relaxing nocturnal periodicity to feed continuously.

Functional response of Fucus vesiculosus communities to tributyltin measured in an in situ continuous flow-through system

Hydrobiologia ◽  
1989 ◽  
Vol 188-189 (1) ◽  
pp. 277-283 ◽  
Author(s):  
C. Lindblad ◽  
U. Kautsky ◽  
C. André ◽  
N. Kautsky ◽  
M. Tedengren
Keyword(s):  
Functional Response ◽  
Continuous Flow ◽  
Fucus Vesiculosus ◽  
Flow Through

Simple flow through reaction cells for in situ transmission and fluorescence x-ray-absorption spectroscopy of heterogeneous catalysts

2006 ◽  
Vol 77 (2) ◽  
pp. 023105 ◽  
Author(s):  
Simon R. Bare ◽  
George E. Mickelson ◽  
Frank S. Modica ◽  
Andrzej Z. Ringwelski ◽  
N. Yang
Keyword(s):  
Absorption Spectroscopy ◽  
Heterogeneous Catalysts ◽  
X Ray ◽  
Flow Through ◽  
X Ray Absorption ◽  
Simple Flow

In situ determination of porewater gases by underwater flow-through membrane inlet mass spectrometry

2012 ◽  
Vol 10 (3) ◽  
pp. 117-128 ◽  
Author(s):  
Ryan J. Bell ◽  
William B. Savidge ◽  
Strawn K. Toler ◽  
Robert H. Byrne ◽  
R. Timothy Short
Keyword(s):  
Mass Spectrometry ◽  
Membrane Inlet Mass Spectrometry ◽  
Flow Through

In Situ Enhancement of Flow-through Porous Electrodes with Carbon Nanotubes via Flowing Deposition

2016 ◽  
Vol 206 ◽  
pp. 36-44 ◽  
Author(s):  
Marc-Antoni Goulet ◽  
Aronne Habisch ◽  
Erik Kjeang
Keyword(s):  
Carbon Nanotubes ◽  
Porous Electrodes ◽  
Flow Through

scholarly journals Numerical Analysis of Fluid Flow on Wall Cylinder Circular with K-ε Modeling for a High Reynolds Rate

2019 ◽  
Vol 1 (3) ◽  
pp. 43-50
Author(s):  
M. Yasep Setiawan ◽  
Wawan Purwanto ◽  
Wanda Afnison ◽  
Nuzul Hidayat
Keyword(s):  
Fluid Flow ◽  
Numerical Study ◽  
General Procedure ◽  
Circular Cylinders ◽  
Cylinder Wall ◽  
Two Dimensional ◽  
Third Order ◽  
Physical Information ◽  
Flow Through ◽  
High Reynolds

This study discusses the numerical study of two-dimensional analysis of flow through circular cylinders. The original physical information entered in the equation governing most of the modeling is transferred into a numerical solution. Fluid flow on two-dimensional circular cylinder wall using high Reynolds k-ε modeling (Re = 106), Here we will do 3 modeling first oder upwind, second order upwind and third order MUSCL by using k-ε standard.  The general procedure for this research is formulated in detail for allocations in the dynamic analysis of fluid computing. The results of this study suggest that MUSCL's third order modeling gives more accurate results better than other models.

Blood flow elevation increases VO2 maximum during repetitive tetanic contractions of dog muscle in situ

1993 ◽  
Vol 74 (4) ◽  
pp. 1499-1503 ◽  
Author(s):  
W. F. Brechue ◽  
B. T. Ameredes ◽  
G. M. Andrew ◽  
W. N. Stainsby
Keyword(s):  
Blood Flow ◽  
Perfusion Pressure ◽  
Power Production ◽  
Arterial Supply ◽  
O2 Uptake ◽  
Plantaris Muscle ◽  
Control Series ◽  
Flow Through ◽  
Series Of Experiments

Blood flow through the gastrocnemius-plantaris muscle of the dog in situ was increased by a pump in the arterial supply during a 30-min period of 1/s isotonic tetanic contractions. Compared with a control series of experiments with normoxemia and spontaneous flow, the pump increased flow 84%, from 1.51 +/- 0.08 to 2.78 +/- 0.15 ml.g-1.min-1. The perfusion pressure was increased from 125 to 196 mmHg. The pump hyperemia increased maximal O2 uptake (VO2) at 5 min of contractions by 31%, from 8.97 +/- 0.44 to 12.89 +/- 0.30 mumol.g-1.min-1. The extraction was decreased, and venous PO2 (PVO2) was increased. Fatigue, measured as a drop in power production from the highest level at 10 s to 30 min, was 49% during pump hyperemia and 54% in the control conditions. VO2 decreased 30% from the 5-min value to the 30-min value with pump hyperemia and 28% over the same time in the control conditions. At maximal VO2, the ratio VO2/PVO2 was increased by pump hyperemia compared with control conditions, suggesting an increased O2 diffusing conductance of the muscles. We conclude that the elevated perfusion pressure of pump hyperemia increased flow to raise maximal VO2 mainly in areas of the muscle that had restricted flow under control conditions.

Perfusion through vessels open in zone 1 contributes to gas exchange in rabbit lungs in situ

1995 ◽  
Vol 79 (6) ◽  
pp. 1895-1899 ◽  
Author(s):  
W. J. Lamm ◽  
T. Obermiller ◽  
M. P. Hlastala ◽  
R. K. Albert
Keyword(s):  
High Frequency ◽  
Pulmonary Arterial Pressure ◽  
Venous Pressure ◽  
High Frequency Oscillation ◽  
Bias Flow ◽  
Flow Through ◽  
Pulmonary Arterial ◽  
Zero Reference ◽  
The Mean

We previously found that up to 15% of the normal cardiac output can flow through lungs that are entirely in zone 1 and that the zone 1 pathway utilizes alveolar corner vessels. Because of the proximity of these vessels to alveoli, we hypothesized that lungs perfused under zone 1 conditions would exchange gas. We used the multiple inert gas elimination technique to assess the ventilation-perfusion (VA/Q) distribution under zones 1 and 2 in six rabbit lungs perfused with tris(hydroxymethyl)aminomethane-buffered Tyrode solution containing 1% albumin, 4% dextran, and papaverine (25 mg/l). High-frequency oscillation (tidal volume = 2.8 ml at 20 Hz, bias flow = 1 l/min) kept alveolar pressure (PA) nearly constant at 10 or 20 cmH2O. Pulmonary arterial pressure was set 2.5 cmH2O below or 5 cmH2O above PA (zones 1 and 2, respectively). Pulmonary venous pressure was kept at 0 cmH2O, with zero reference being the bottom of the lung. At PA of 10 cmH2O, flow was 64 +/- 40 and 5 +/- 3 ml/min (P < 0.05) and the mean VA/Q for perfusion was 1.1 +/- 0.4 and > 5 (P < 0.05) in zones 2 and 1, respectively. At PA of 20 cmH2O, flow was 89 +/- 36 and 22 +/- 13 ml/min (P < 0.05) and the mean VA/Q for perfusion was 0.8 +/- 0.3 and 3.7 +/- 2.4 (P < 0.05) in zones 2 and 1, respectively. Shunt averaged < 5% of total flow in all conditions. Blood flowing through vessels remaining open under zone 1 conditions 1) exchanges gas, 2) does not occur through anatomic or physiological shunts, and 3) may explain the high VA/Q seen with positive end-expiratory pressure.

scholarly journals In situ mapping of the energy flow through the entire photosynthetic apparatus

2016 ◽  
Vol 8 (7) ◽  
pp. 705-710 ◽  
Author(s):  
Jakub Dostál ◽  
Jakub Pšenčík ◽  
Donatas Zigmantas
Keyword(s):  
Energy Flow ◽  
Photosynthetic Apparatus ◽  
Flow Through

Physiological and pharmacological response of canine bronchial smooth muscle in situ

1983 ◽  
Vol 54 (1) ◽  
pp. 215-224 ◽  
Author(s):  
S. G. Hendrix ◽  
N. M. Munoz ◽  
A. R. Leff
Keyword(s):  
Smooth Muscle ◽  
Electrical Stimulation ◽  
Maximal Response ◽  
Repeated Injection ◽  
Third Order ◽  
Bronchial Smooth Muscle ◽  
Pure Nitrogen ◽  
Parasympathetic Ganglion ◽  
The Right

We studied the isometric response of bronchial smooth muscle in a single third-order bronchus of 24 dogs in situ. Length-tension studies were performed in six dogs by repeated injection of 10(-5) mol acetylcholine (ACh) into the right bronchoesophageal artery, and the resting tension (30.6 +/- 6.9 g/cm) and length (0.76 +/- 0.14 cm) permitting maximal contraction were determined. In eight other dogs, dose-related bronchial contraction was obtained with 10(-10) to 10(-5) mol intra-arterial (ia) ACh. Supramaximal electrical stimulation of the right cervical vagus nerve and bronchial parasympathetic ganglion stimulation with ia 1–1-dimethyl-4-phenylpiperazinium (DMPP) also caused bronchial contraction. The maximal response to ia ACh (28.5 +/- 1.7 g/cm), supramaximal electrical stimulation (15.2 +/- 1.1 g/cm), and ia DMPP (10.5 +/- 3.0 g/cm) was blocked by an ia dose of atropine (1–5 micrograms/kg) that did not alter the sympathetic relaxation response in the trachea. In four dogs, the bronchial response to sympathetic activation was studied by intravenous (iv) bolus injection of DMPP after cholinergic blockade with atropine. DMPP (25 micrograms/kg iv) caused 9.5 +/- 2.2 g/cm bronchial relaxation, which was blocked completely by 2–4 mg/kg iv propranolol. In six other dogs, hypoxia induced by ventilation with pure nitrogen caused bronchial contraction, which was blocked by vagotomy, atropine, and hexamethonium. We report a sensitive method for selective measurement of bronchial smooth muscle response in a single resistance bronchus. This preparation preserves regional innervation and circulation and permits selective physiological stimulation in situ.

CONTINUOUS RADON-IN-WATER MONITORING—COMPARISON OF METHODS UNDER LABORATORY CONDITIONS AND RESULTS OF IN SITU MEASUREMENTS

2019 ◽  
Vol 186 (2-3) ◽  
pp. 406-412
Author(s):  
Petra Vyletělová ◽  
Aleš Froňka
Keyword(s):  
Response Time ◽  
Detection System ◽  
Response Delay ◽  
Detection Systems ◽  
Water Detection ◽  
Radon Diffusion ◽  
Flow Through ◽  
Continuous Monitor ◽  
Radon In Water

Abstract The extraction of dissolved radon from water to gas is the most common way to measure radon concentration in water continuously. The response delay of continuous radon-in-water detection system (continuous monitor + equilibrator) is influenced by the response time of the continuous monitor and a rate of an establishment of equilibrium in the equilibrator (exchanger unit). Two types of equilibrators were used in performed experiments to compare the response time of various detection systems—RAD AQUA that uses water spraying and equilibrator with ACCUREL® PP membrane that enables radon diffusion. Each of these was connected to the continuous monitor RAD7 or RM-3. The response delay after turning on the water flow through the equilibrator was determined. The fastest detection system was RAD7 + RAD AQUA that was subsequently tested during the insitu measurement of thermal water in the healing spa and water sources near Cheb and České Budějovice.

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