Aggressive Communication By Lar Us Gla Ucescens Part I. Sound Communication

Behaviour ◽  
1969 ◽  
Vol 34 (1-2) ◽  
pp. 29-41 ◽  
Author(s):  
John F. Stout ◽  
Carl R. Wilcox ◽  
Lynn E. Creitz
Keyword(s):  
Sound Production ◽  
Control Period ◽  
Alarm Call ◽  
Experimental Period ◽  
Paired Comparisons ◽  
Sound Communication ◽  
Communicative Functions ◽  
Aggressive Communication ◽  
Territorial Bird ◽  
Larus Glaucescens

AbstractThe communicative functions of sound production during aggressive activity were studied by playing back the choking, trumpeting, mew, alarm and yelp calls to Larus glaucescens reacting aggressively to a mirror placed within its territory or by measuring the latency of attack on a stuffed model mounted in one of the display postures involved in aggressive activity. Differences between the experimental period with sound playback, and the control period with no sound playback were analyzed statistically by means of paired comparisons t-tests. As the result of these experiments the following conclusions were reached: I. The choking sound would inhibit the entrance of an intruder when produced by the territorial bird, but when produced by the intruder would stimulate the aggressive activity of the territorial resident. 2. The mew call functions similarly to the choking call but probably represents a somewhat lesser degree of aggressiveness. 3. The trumpeting call hastens an attack by a bird outside of its territory when produced within its territory and also stimulates aggressive activity of a bird within its territory, when produced by an intruder. 4. The alarm call inhibits aggressive activity, although it is not a usual part of aggressive activity. 5. The yelp call does not effect aggressive activity.

Effect of V2-receptor-mediated changes on inner medullary blood flow induced by AVP

1987 ◽  
Vol 253 (3) ◽  
pp. F576-F581 ◽  
Author(s):  
B. Kiberd ◽  
C. R. Robertson ◽  
T. Larson ◽  
R. L. Jamison
Keyword(s):  
Blood Flow ◽  
Recovery Period ◽  
Control Period ◽  
Experimental Period ◽  
Urinary Flow ◽  
Medullary Blood Flow ◽  
Period 2 ◽  
Group I ◽  
Vasa Recta ◽  
V2 Receptor

We have previously shown that arginine vasopressin (AVP) in physiological amounts reduces inner medullary blood flow and that the mechanism of this decrease is at least in part mediated by the vasopressor (V1-receptor) action of AVP. To determine whether the antidiuretic action of AVP (V2-receptor) also contributes to the reduction in inner medullary blood flow, we determined capillary blood flow (QVR) in individual descending vasa recta (DVR) and ascending vasa recta (AVR) using fluorescence videomicroscopy in the exposed renal papilla of the anesthetized rat. Three groups of chronically water-diuretic rats were studied in three consecutive periods: control (period 1), experimental (period 2), and recovery (period 3). Group I rats (designated the AVP group) received AVP, 45 ng X h-1 X kg body wt-1; group II (AVP + V2-inhibitor), AVP plus its specific antidiuretic antagonist d(CH2)5[D-Ile2,Thr4]AVP; and group III (V2-inhibitor), the antagonist alone, respectively, in the experimental period 2. Only group I rats concentrated their urine, urine osmolality (Uosmol) = 499 +/- 48 mosmol/kgH2O, whereas urine remained hypotonic throughout in groups II and III. In group I, QVR in DVR and AVR decreased in period 2; but in groups II and III, QVR tended to increase. These results suggest that the AVP-induced decrease in papillary vasa recta blood flow is in part mediated by its antidiuretic V2-receptor as well as by its vasopressor (V1-receptor). They also suggest that the rate of urinary flow in the medullary collecting ducts is a determinant of inner medullary blood flow.

scholarly journals Impact of point-of-care testing on patients' length of stay in a large emergency department

1996 ◽  
Vol 42 (5) ◽  
pp. 711-717 ◽  
Author(s):  
C A Parvin ◽  
S F Lo ◽  
S M Deuser ◽  
L G Weaver ◽  
L M Lewis ◽  
...  
Keyword(s):  
Emergency Department ◽  
Length Of Stay ◽  
Point Of Care ◽  
Control Period ◽  
Experimental Period ◽  
Central Laboratory ◽  
Point Of Care Testing ◽  
Acceptable Accuracy ◽  
Patient Interview ◽  
Combined Control

Abstract We prospectively investigated whether routine use of a point-of-care testing (POCT) device by nonlaboratory operators in the emergency department (ED) for all patients requiring the available tests could shorten patient length of stay (LOS) in the ED. ED patient LOS, defined as the length of time between triage (initial patient interview) and discharge (released to home or admitted to hospital), was examined during a 5-week experimental period in which ED personnel used a hand-held POCT device to perform Na, K, Cl, glucose (Gluc), and blood urea nitrogen (BUN) testing. Preliminary data demonstrated acceptable accuracy of the hand-held device. Patient LOS distribution during the experimental period was compared with the LOS distribution during a 5-week control period before institution of the POCT device and with a 3-week control period after its use. Among nearly 15 000 ED patient visits during the study period, 4985 patients (2067 during the experimental period and 2918 during the two control periods) had at least one Na, K, Cl, BUN, or Gluc test ordered from the ED. However, no decrease in ED LOS was observed in the tested patients during the experimental period. Median LOS during the experimental period was 209 min vs 201 min for the combined control periods. Stratifying patients by presenting condition (chest pain, trauma, etc.), discharge/admit status, or presence/absence of other central laboratory tests did not reveal a decrease in patient LOS for any patient subgroup during the experimental period. From these observations, we consider it unlikely that routine use of a hand-held POCT device in a large ED such as ours is sufficient by itself to impact ED patient LOS.

557. Studies of the secretion of milk of low fat content by cows on diets low in hay and high in concentrates: IV. The effect of variations in the intake of digestible nutrients

1954 ◽  
Vol 21 (3) ◽  
pp. 305-317 ◽  
Author(s):  
C. C. Balch ◽  
D. A. Balch ◽  
S. Bartlett ◽  
V. W. Johnson ◽  
S. J. Rowland ◽  
...  
Keyword(s):  
Milk Fat ◽  
Crude Protein ◽  
Control Period ◽  
Experimental Period ◽  
Fat Content ◽  
The Other ◽  
Essential Difference ◽  
Crude Fibre ◽  
Initial Control ◽  
Concentrate Mixture

1. Digestibility trials were conducted, and the rate of passage of hay was measured, with five Shorthorn cows during a period of normal diet and during two experimental periods in which diets low in hay and high in concentrates were given. In the first experimental period the concentrates were cubes of the wartime type sold as National Cattle Food No. 1, and containing a variety of constituents; in the second they were a mixture offlakedmaize (50%), weatings (35%) and decorticated ground-nut cake (15%). For convenience these are referred to as concentrate ‘cubes’ and ‘mixture’ respectively.2. During the initial and final control periods the cows consumed daily 17–21 lb. hay, and about 4·5 lb. concentrates per 10 lb. of milk produced. In the initial control period the concentrates were the concentrate cubes, and in the final they were the concentrate mixture. The hay was reduced to 4 lb. daily during the two experimental periods and the remainder of the standard requirements of the animals were met by concentrates. The concentrates were the cubes in the first experimental period and the mixture in the second experimental period.3. Seducing the hay to 4 lb. did not affect the fat content of the milk when the other food in the diet was the concentrate cubes, but there was a striking mean fall of 1·04% fat when the cubes were replaced by the concentrate mixture. This represented a loss of over 30% in the yield of fat.4. Digestibility trials, conducted in the initial control and first and second experimental periods, indicated that the fall in milk fat content was not the result of changes in the amounts of dry matter, crude protein, ether extract, crude fibre, cellulose, cellulosans or pentosans not in cellulose digested. The essential difference between the diet of low hay with the concentrate mixture and the other diets given in this experiment was that it provided a high intake of starch yet had little of the physical property of roughage. It is concluded that depression of milk fat content results from a combination of these two factors and probably originates from changes in the physical and biochemical processes of the reticulo-rumen.5. The intake of starch equivalent, as calculated from the intake of digestible nutrients, was close to standard requirements in all periods of the experiments, but there was a surplus of digestible crude protein.6. The mean solids-not-fat content of the milk rose 0·48% at the time of the fall in milk fat, and this was entirely due to an increase in milk protein. After the return to normal diets the recovery of solids-not-fat was slower, but no less complete, than the recovery in milk fat.

scholarly journals Impact of a structured review session on medical student psychiatry subject examination performance

F1000Research ◽  
2015 ◽  
Vol 4 ◽  
pp. 897
Author(s):  
Shan H. Siddiqi ◽  
Kevin J. Black ◽  
Fay Y. Womer
Keyword(s):  
Medical Students ◽  
Small Sample Size ◽  
Control Period ◽  
Experimental Period ◽  
Small Sample ◽  
Future Research ◽  
National Board ◽  
Subject Examination ◽  
The Impact ◽  
Review Session

Introduction: The National Board of Medical Examiners (NBME) subject examinations are used as a standardized metric for performance in required clerkships for third-year medical students. While several medical schools have implemented a review session to help consolidate knowledge acquired during the clerkship, the effects of such an intervention are not yet well-established. An improvement in NBME psychiatry examination scores has previously been reported with a single end-of-clerkship review session, but this was limited by a small sample size and the fact that attendance at the review session was optional, leading to likely selection bias.Methods: A 1.5-hour structured review session was conducted for medical students in the last week of each 4-week psychiatry clerkship between September 2014 and July 2015. Students were required to attend unless excused due to scheduling conflicts. Scores on the NBME psychiatry subject exam were compared with those of students taking the examination in the corresponding time period in each of the previous two academic years.Results: 83 students took the exam during the experimental period, while 176 took the exam during the control period. Statistically significant improvements were found in mean score (p=0.03), mean for the two lowest scores in each group (p<0.0007), and percentage of students scoring 70 or less (p=0.03). Percentage of students achieving the maximum possible score (99) was higher in the experimental group, but did not reach significance (p=0.06).Conclusions: An end-of-clerkship review session led to increased mean scores on the NBME psychiatry subject examination, particularly for students at the lower end of the score range. Future research should investigate the impact of such an intervention in other specialties and other institutions.

Role of extracellular Ca2+ in hepatic bile formation and taurocholate transport

1985 ◽  
Vol 249 (6) ◽  
pp. G711-G718 ◽  
Author(s):  
M. S. Anwer ◽  
L. M. Clayton
Keyword(s):  
Control Period ◽  
Rat Hepatocytes ◽  
Experimental Period ◽  
Isolated Hepatocytes ◽  
Hepatic Uptake ◽  
Hepatic Bile ◽  
Bile Formation ◽  
Isolated Rat Hepatocytes ◽  
Diffusional Permeability

The role of extracellular Ca2+ in hepatic bile formation, biliary membrane permeability, and taurocholate (TC) transport was studied in isolated perfused rat livers and in isolated rat hepatocytes to determine the functional importance of paracellular permeability in biliary bile acid excretion. Each liver was perfused for 1 h with perfusate containing 1.3 mM Ca2+ (control period) followed by another hour with 1.3, 0.5, 0.1, 0.05, 0.03, or 0.01 mM Ca2+ (experimental period). Basal bile flow and biliary excretion of added TC declined significantly only at and below 0.05 mM perfusate Ca2+ and was associated with an increase in bile-to-perfusate concentration ratio of [3H]inulin (B/P inulin ratio). A twofold increase in the diffusional permeability coefficient at 0.05 mM and a sixfold increase at 0.03 and 0.01 mM perfusate Ca2+ could explain the increased in B/P inulin ratios. Time-dependent increases in cell-to-medium concentration ratios of inulin were less in the absence than in the presence of Ca2+. Hepatic uptake rates of TC determined in isolated hepatocytes and from perfusate disappearance of added TC and efflux rates of TC from preloaded hepatocytes were not significantly affected by Ca2+ removal. It is possible that the observed decline in biliary TC excretion at low perfusate Ca2+ is due to regurgitation of secreted TC back into the perfusate followed by reuptake. This was supported by an accumulation of perfusate radioactivity when TC uptake inhibitors (furosemide and bumetanide) were added to the perfusate (0.03 mM Ca2+) 60 min after the addition of [14C]TC.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of area postrema lesion on low-frequency arterial pressure oscillations in dogs

1987 ◽  
Vol 253 (3) ◽  
pp. H524-H530 ◽  
Author(s):  
F. E. Pollick ◽  
K. L. Barnes ◽  
C. M. Ferrario
Keyword(s):  
Arterial Pressure ◽  
Area Postrema ◽  
Control Period ◽  
Power Spectra ◽  
Low Frequency ◽  
Experimental Period ◽  
Low Frequency Oscillation ◽  
Pressure Oscillations ◽  
Before And After ◽  
Group A

To explore the possibility that chronic inactivation of the area postrema (AP) may alter the frequency distribution of oscillations in blood pressure, the power spectra for mean arterial pressure (MAP) were evaluated in conscious dogs before and after heat coagulation (n = 4) or sham lesions (n = 6) of the AP. No significant changes in MAP were observed in either group of dogs after surgery. Tachycardia was seen in AP-lesioned animals after surgery; no consistent changes in heart rate were found in sham-lesioned dogs. Spectra were averaged to provide a group spectral estimate for the AP-lesioned and sham-lesioned groups, respectively, for each experimental period. In the sham-lesioned group a variance peak was observed at approximately 0.03 Hz both before and after surgery. The same peak was seen in the AP-lesioned group during the control period but disappeared following AP lesion, apparently because a greater proportion of the variance was shifted toward frequencies below 0.03 Hz. In addition, a peak related to respiratory rate was present in both groups before surgery but was selectively abolished by AP lesion. AP lesion also substantially reduced the power associated with frequencies between 0.1 and 0.4 Hz. The use of spectral analysis has allowed us to demonstrate that a low-frequency oscillation of MAP in conscious, resting dogs requires the integrity of the AP and that the 0.1- to 0.4-Hz components of the variability of MAP are attenuated after removal of the AP.(ABSTRACT TRUNCATED AT 250 WORDS)

Prior exercise increases net hepatic glucose uptake during a glucose load

1999 ◽  
Vol 276 (6) ◽  
pp. E1022-E1029 ◽  
Author(s):  
Pietro Galassetti ◽  
Robert H. Coker ◽  
Drury B. Lacy ◽  
Alan D. Cherrington ◽  
David H. Wasserman
Keyword(s):  
Portal Vein ◽  
Glucose Uptake ◽  
Control Period ◽  
Vena Cava ◽  
Experimental Period ◽  
Glucose Infusion ◽  
Glucose Load ◽  
Prior Exercise ◽  
Hepatic Glucose ◽  
Hepatic Glucose Uptake

The aim of these studies was to determine whether prior exercise enhances net hepatic glucose uptake (NHGU) during a glucose load. Sampling catheters (carotid artery, portal, hepatic, and iliac veins), infusion catheters (portal vein and vena cava), and Doppler flow probes (portal vein, hepatic and iliac arteries) were implanted. Exercise (150 min; n = 6) or rest ( n = 6) was followed by a 30-min control period and a 100-min experimental period (3.5 mg ⋅ kg−1⋅ min−1of glucose in portal vein and as needed in vena cava to clamp arterial blood glucose at ∼130 mg/dl). Somatostatin was infused, and insulin and glucagon were replaced intraportally at fourfold basal and basal rates, respectively. During experimental period the arterial-portal venous (a-pv) glucose gradient (mg/dl) was −18 ± 1 in sedentary and −19 ± 1 in exercised dogs. Arterial insulin and glucagon were similar in the two groups. Net hepatic glucose balance (mg ⋅ kg−1⋅ min−1) shifted from 1.9 ± 0.2 in control period to −1.8 ± 0.2 (negative rates represent net uptake) during experimental period in sedentary dogs (Δ3.7 ± 0.5); with prior exercise it shifted from 4.1 ± 0.3 ( P < 0.01 vs. sedentary) in control period to −3.2 ± 0.4 ( P < 0.05 vs. sedentary) during experimental period (Δ7.3 ± 0.7, P < 0.01 vs. sedentary). Net hindlimb glucose uptake (mg/min) was 4 ± 1 in sedentary animals in control period and 13 ± 2 during experimental period; in exercised animals it was 7 ± 1 in control period ( P < 0.01 vs. sedentary) and 32 ± 4 ( P < 0.01 vs. sedentary) during experimental period. As the total glucose infusion rate (mg ⋅ kg−1⋅ min−1) was 7 ± 1 in sedentary and 11 ± 1 in exercised dogs, ∼30% of the added glucose infusion due to prior exercise could be accounted for by the greater NHGU. In conclusion, when determinants of hepatic glucose uptake (insulin, glucagon, a-pv glucose gradient, glycemia) are controlled, prior exercise increases NHGU during a glucose load due to an effect that is intrinsic to the liver. Increased glucose disposal in the postexercise state is therefore due to an improved ability of both liver and muscle to take up glucose.

Age-dependent core temperature responses of conscious rabbits to acute hypoxemia

2000 ◽  
Vol 89 (1) ◽  
pp. 259-264
Author(s):  
James E. Fewell ◽  
Sarah H. M. Wong ◽  
Kim C. Crisanti
Keyword(s):  
Core Temperature ◽  
Recovery Period ◽  
Control Period ◽  
Experimental Period ◽  
Thermoregulatory Response ◽  
Postnatal Maturation ◽  
Age Dependent ◽  
Fraction Of Inspired Oxygen ◽  
Temperature Responses ◽  
Inspired Oxygen

Experiments were carried out on chronically instrumented newborn and older rabbits to characterize their core temperature (Tc) responses to acute hypoxemia and to differentiate “forced” vs. “regulated” thermoregulatory responses. Three age ranges of kits were studied: 4–6, 9–11, and 28–30 days of age. During an experiment, Tc, selected ambient temperature (Ta), and oxygen consumption were measured from kits studied in a thermocline during a control period of normoxemia, an experimental period of normoxemia or hypoxemia (fraction of inspired oxygen 0.10), and a recovery period of normoxemia. We reasoned that no change or a decrease in Tawhile Tc decreased during hypoxemia would indicate a regulated thermoregulatory response, whereas an increase in Ta while Tc decreased during hypoxemia would indicate a forced thermoregulatory response. Tc decreased during acute hypoxemia in the older kits but not in the 4- to 6-day-old kits; the decrease in Tc was accentuated on postnatal days 28–30 compared with postnatal days 9–11. Ta decreased or stayed the same during exposure to acute hypoxemia. Our data provide evidence that postnatal maturation influences the Tc response of rabbits to acute hypoxemia and that the decrease in Tc during hypoxemia in the older kits results from a regulated thermoregulatory response.

Aggressive Communication By Larus Glaucescens Iii. Description of the Displays Related To Territorial Protection

Behaviour ◽  
1975 ◽  
Vol 55 (3-4) ◽  
pp. 181-207 ◽  
Author(s):  
John F. Stout
Keyword(s):  
Alarm Calls ◽  
Physical Analysis ◽  
Harmonic Structure ◽  
Differential Function ◽  
Motion Picture Film ◽  
Aggressive Interactions ◽  
Aggressive Communication ◽  
Aggressive Calls ◽  
Head Level ◽  
Larus Glaucescens

AbstractThis paper is a description of the aggressive activities of the Glaucous-winged Gull, Larus glaucescens. It provides a descriptive basis for the interpretation of experiments designed to elucidate the aggressive communication of this species (STOUT & BRASS, 1969; STOUT, WILCOX & CREITZ, 1969; and in progress). The descriptions of the aggressive behavior of L. glaucescens were based on the analysis of 12,000 feet of motion picture film, and on the physical analysis of a large number of sound spectrograms (sonograms) of each of the aggressive calls. The behavior observed was classified with respect to its association with attack, escape, or other aggressive interactions, and also with respect to its production by territorial defender or intruder. The Aggressive Upright, Moving Aggressive Upright, Intimidated Upright, Trumpeting, Mew, Grass-pulling, Jabbing, and Choking displays were described. The Forward display, as described for other larids, was not seen. The physical analysis of the aggressive calls of the Glaucous-winged Gull demonstrated great similarity between the Trumpeting and Yelp Calls. The Courtship, Parent-young, and Aggressive Mews were demonstrated to have consistent physical differences. It was suggested that they could each have a different function. The Choking and Alarm Calls are similar in that they have a more complex harmonic structure than the other calls. However, a differential function has already been demonstrated for these two calls (STOUT, WILCOX & CREITZ, 1969). It was hypothesized that each of these aggressive displays communicates distinct levels of threat. The combination of head level (posture), call, orientation, and movement were considered as possible factors resulting in the distinction between displays. It was suggested that the Upright Threat, Trumpeting, Mew, and Choking displays communicate increasing levels of threat in that order. This model was evaluated in relationship to experiments performed on aggressive communication by L. glaucescens.

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