scholarly journals Time-activity and energy budgets of Eared Grebes (Podiceps nigricollis) at Salton Sea

2017 ◽  
Author(s):  
Samantha San Francisco
Keyword(s):  
Salton Sea ◽  
Energy Budgets ◽  
Time Activity ◽  
Podiceps Nigricollis

scholarly journals Stratification, sulfide, worms, and decline of the Eared Grebe (Podiceps nigricollis) at the Salton Sea, California

2007 ◽  
Vol 23 (5) ◽  
pp. 500-517 ◽  
Author(s):  
Thomas W. Anderson ◽  
Mary Ann Tiffany ◽  
Stuart H. Hurlbert
Keyword(s):  
Salton Sea ◽  
Eared Grebe ◽  
Podiceps Nigricollis

scholarly journals As clear as day: nocturnal activity differs from diurnal activity in a temporally constrained capital breeder

Behaviour ◽  
2019 ◽  
Vol 156 (10) ◽  
pp. 997-1016 ◽  
Author(s):  
Zoe L. Fraser ◽  
Ross M. Culloch ◽  
Sean D. Twiss
Keyword(s):  
Activity Patterns ◽  
Video Camera ◽  
Energy Budgets ◽  
Implicit Assumption ◽  
Diurnal Activity ◽  
Nocturnal Activity ◽  
Activity Budgets ◽  
Time Activity ◽  
Direct Observations ◽  
In The Wild

Abstract Time-activity budgets are fundamental to behavioural studies, allowing examination of how individuals allocate their time, and potentially energy, and how these patterns vary spatially and temporally and in relation to habitat, individual identity, sex, social status and levels of anthropogenic disturbance. Direct observations of animal behaviour, especially in the wild, are often limited to daylight hours; therefore, many activity budgets relate to diurnal activity only, or assumptions are made about nocturnal activity. Activity budgets have been a key component of many behavioural and energetics studies of breeding grey seals (Halichoerus grypus, Fabricius, 1791), and yet very little is known about nocturnal activity of grey seals, and a general, implicit assumption of no significant change from day to night seems to pervade the literature. Here we use a combination of high resolution digital video and thermal imaging video camera to follow known individual grey seal mothers from day into night to examine activity patterns during lactation. We show distinct differences in nocturnal activity budgets relative to diurnal activity budgets. Mothers spent significantly more time resting with a reduction of time spent in the alert and comfort move behavioural categories during nocturnal periods. It is clear that diurnal time-activity patterns of breeding female grey seals cannot be extrapolated to represent activity across a 24-hour cycle. These considerations are particularly critical in studies that aim to use time-activity budgets as proxies for energy budgets.

The Influence of Lactate and Dipyridamole on Myocardial Fatty Acid Metabolism in Man, Traced with 123l-17-lodo-heptadecanoic Acid

1990 ◽  
Vol 29 (01) ◽  
pp. 28-34 ◽  
Author(s):  
F. C. Visser ◽  
M. J. van Eenige ◽  
G. Westera ◽  
J. P. Roos ◽  
C. M. B. Duwel
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Metabolism ◽  
Acid Metabolism ◽  
Time Activity ◽  
Time Value ◽  
Myocardial Fatty Acid Metabolism ◽  
Coronary Vasodilatation ◽  
Activity Curve ◽  
Normal Human ◽  
Plasma Lactate Level

Changes in myocardial metabolism can be detected externally by registration of time-activity curves after administration of radioiodinated fatty acids. In this scintigraphic study the influence of lactate on fatty acid metabolism was investigated in the normal human myocardium, traced with 123l-17-iodoheptadecanoic acid (123l-17-HDA). In patients (paired, n = 7) lactate loading decreased the uptake of 123l-17-HDA significantly from 27 (control: 22-36) to 20 counts/min/pixel (16-31; p <0.05 Wilcoxon). The half-time value increased to more than 60 rriin (n = 5), oxidation decreased from 61 to 42%. Coronary vasodilatation, a well-known side effect of lactate loading, was studied separately in a dipyridamole study (paired, n = 6). Coronary vasodilatation did not influence the parameters of the time-activity curve. These results suggest that changes in plasma lactate level as occurring, among other effects, during exercise will influence the parameters of dynamic 123l-17-HDA scintigraphy of the heart.

Dynamic Scintigraphy of the Oesophagus in the Evaluation of Reflux Oesophagitis

1990 ◽  
Vol 29 (05) ◽  
pp. 204-209
Author(s):  
B. Ugarković ◽  
D. Ivančević ◽  
D. Babić ◽  
Ž. Babić
Keyword(s):  
Reflux Oesophagitis ◽  
Oesophageal Reflux ◽  
Low Grade ◽  
Time Activity ◽  
The Difference ◽  
Asymptomatic Subjects ◽  
Oesophageal Transit ◽  
Dynamic Scintigraphy ◽  
Positive Results ◽  
Reflux Œsophagitis

A method is presented which combines gastro-oesophageal reflux quantification and oesophageal transit measurement so as to differentiate true reflux from residual oesophageal activity. A group of 33 subjects with gastro-oesophageal reflux symptoms and endoscopically confirmed reflux oesophagitis and a group of 21 asymptomatic subjects with normal oesophageal, gastric and duodenal endoscopic findings were examined. The subjects were given 37 MBq 99mTc-Sn-colloid in saline orally and then scintiscanned dynamically. The gastro-oesophageal quantification was done after transit measurement and after the oesophageal time activity (to detect residual oesophageal activity) reached its minimum. The difference in the reflux indices between the two groups was highly significant. In low-grade oesophagitis measured reflux was lower than in higher grades of disease. Only 4.7% false-positive results were observed with a specificity of 95%, indicating that this method may be superior to methods published earlier.

Measurement of Renal Parenchymal Transit Time of 99mTc-MAG3 Using Factor Analysis

1990 ◽  
Vol 29 (04) ◽  
pp. 170-176 ◽  
Author(s):  
M. V. Yester ◽  
Eva Dubovsky ◽  
C. D. Russell
Keyword(s):  
Factor Analysis ◽  
Transit Time ◽  
Region Of Interest ◽  
Initial Slope ◽  
Cortical Region ◽  
Time Activity ◽  
Appearance Time ◽  
Activity Curve ◽  
System Factor ◽  
Collecting System

Renal parenchymal transit time of the recently introduced radiopharmaceutical 99mTc-MAG3 (mercaptoacetylglycylglylcylglycinel) was measured in 37 kidneys, using factor analysis to separate parenchymal activity from that in the collecting system. A new factor algorithm was employed, based on prior interpolative background subtraction and use of the fact that the initial slope of the collecting system factor time-activity curve must be zero. The only operator intervention required was selection of a rectangular region enclosing the kidney (by identifying two points at opposite corners). Transit time was calculated from the factor time-activity curves both by deconvolution of the parenchymal factor curve and also by measuring the appearance time for collecting system activity from the collecting system factor curve. There was substantial agreement between the two methods. Factor analysis led to a narrower range of normal values than a conventional cortical region-of-interest method, presumably by decreasing crosstalk from the collecting system. In preliminary trials, the parenchymal transit time did not well separate four obstructed from seventeen unobstructed kidneys, but it successfully (p <0.05) separated six transplanted kidneys with acute rejection or acute tubular necrosis from 10 normal transplants.

Analysis of Myocardial Time-Activity Curves of 123l-Heptadecanoic Acid II. The Acquisition Time

1987 ◽  
Vol 26 (06) ◽  
pp. 248-252 ◽  
Author(s):  
M. J. van Eenige ◽  
F. C. Visser ◽  
A. J. P. Karreman ◽  
C. M. B. Duwel ◽  
G. Westera ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Acquisition Time ◽  
Half Time ◽  
Constant Ratio ◽  
Time Activity ◽  
Time Activity Curve ◽  
Time Value ◽  
Activity Curve ◽  
Low Amplitude ◽  
Parameter Values

Optimal fitting of a myocardial time-activity curve is accomplished with a monoexponential plus a constant, resulting in three parameters: amplitude and half-time of the monoexponential and the constant. The aim of this study was to estimate the precision of the calculated parameters. The variability of the parameter values as a function of the acquisition time was studied in 11 patients with cardiac complaints. Of the three parameters the half-time value varied most strongly with the acquisition time. An acquisition time of 80 min was needed to keep the standard deviation of the half-time value within ±10%. To estimate the standard deviation of the half-time value as a function of the parameter values, of the noise content of the time-activity curve and of the acquisition time, a model experiment was used. In most cases the SD decreased by 50% if the acquisition time was increased from 60 to 90 min. A low amplitude/constant ratio and a high half-time value result in a high SD of the half-time value. Tables are presented to estimate the SD in a particular case.

The Hemostatic Mechanism after Open-Heart Surgery

1978 ◽  
Vol 39 (02) ◽  
pp. 474-487 ◽  
Author(s):  
E R Cole ◽  
F Bachmann ◽  
C A Curry ◽  
D Roby
Keyword(s):  
Extracorporeal Circulation ◽  
Heart Surgery ◽  
Polyacrylamide Gel Electrophoresis ◽  
Open Heart Surgery ◽  
Coagulation System ◽  
Open Heart ◽  
Time Activity ◽  
Post Surgery ◽  
Plasma Fractions ◽  
The Mean

SummaryA prospective study in 13 patients undergoing open-heart surgery with extracorporeal circulation revealed a marked decrease of the mean one-stage prothrombin time activity from 88% to 54% (p <0.005) but lesser decreases of factors I, II, V, VII and X. This apparent discrepancy was due to the appearance of an inhibitor of the extrinsic coagulation system, termed PEC (Protein after Extracorporeal Circulation). The mean plasma PEC level rose from 0.05 U/ml pre-surgery to 0.65 U/ml post-surgery (p <0.0005), and was accompanied by the appearance of additional proteins as evidenced by disc polyacrylamide gel electrophoresis of plasma fractions (p <0.0005). The observed increases of PEC, appearance of abnormal protein bands and concomitant increases of LDH and SGOT suggest that the release of an inhibitor of the coagulation system (similar or identical to PIVKA) may be due to hypoxic liver damage during extracorporeal circulation.

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