Quantitative studies of the reactions to horizontal angular accelerations in axolotls. I. The head-turning reflexes of normal animals

1977 ◽  
Vol 66 (1) ◽  
pp. 1-14
Author(s):  
K. Brandle
Keyword(s):  
Stimulus Intensity ◽  
Time Course ◽  
Maximum Velocity ◽  
Afferent Input ◽  
Head Turning ◽  
Mean Values ◽  
Quantitative Studies ◽  
The Mean ◽  
Negative Exponential ◽  
Total Angle

1. Artifically metamorphosed axolotls were exposed to both brief (impulse) and long-lasting horizontal angular accelerations on a turn-table. The animals responded with a head-turning reaction. 2. The general course of the reaction to impulse acceleration was independent of stimulus intensity. The velocity of the head movement first increased to a maximum exponentially and then decreased in a negative exponential manner. Stimulus intensity had a linear relationship to the mean maximum velocity and mean total angle covered by head-turning. The average velocity-time curves at various stimulus intensities differed only by a velocity factor. 3. During long-lasting constant accelerations the velocity of the head-turning increased to a maximum velocity in a sigmoid time-course and then decreased, first to a constant velocity, and then further. Mean values of the maximum velocity were correlated linearly with the stimulus intensity. 4. It was concluded that the head-turning reflexes in axolotls do not agree with the accepted movements of the vertebrate cupula and therefore are not a simple ‘copy’ of the afferent input. It is also suggested that the reaction threshold differes from that for the labyrinthine input.

scholarly journals The use of a neck brace does not influence visual vertical perception

2011 ◽  
Vol 69 (3) ◽  
pp. 509-512 ◽  
Author(s):  
Martha Funabashi ◽  
Natya N.L. Silva ◽  
Luciana M. Watanabe ◽  
Taiza E.G Santos-Pontelli ◽  
José Fernando Colafêmina ◽  
...  
Keyword(s):  
Healthy Volunteers ◽  
Healthy Subjects ◽  
Afferent Input ◽  
Subjective Visual Vertical ◽  
Sensory Receptors ◽  
Ocular Torsion ◽  
Vertical Orientation ◽  
Mean Values ◽  
Visual Vertical ◽  
The Mean

Subjective visual vertical (SVV) evaluates the individual's capacity to determine the vertical orientation. Using a neck brace (NB) allow volunteers' heads fixation to reduce cephalic tilt during the exam, preventing compensatory ocular torsion and erroneous influence on SVV result. OBJECTIVE: To analyze the influence of somatosensory inputs caused by a NB on the SVV. METHOD: Thirty healthy volunteers performed static and dynamic SVV: six measures with and six without the NB. RESULTS: The mean values for static SVV were -0.075º±1.15º without NB and -0.372º±1.21º with NB. For dynamic SVV in clockwise direction were 1.73º±2.31º without NB and 1.53º±1.80º with NB. For dynamic SVV in counterclockwise direction was -1.50º±2.44º without NB and -1.11º±2.46º with NB. Differences between measurements with and without the NB were not statistically significant. CONCLUSION: Although the neck has many sensory receptors, the use of a NB does not provide sufficient afferent input to change healthy subjects' perception of visual verticality.

scholarly journals Force-Velocity Relationship in the Countermovement Jump Exercise Assessed by Different Measurement Methods

2019 ◽  
Vol 67 (1) ◽  
pp. 37-47 ◽  
Author(s):  
Amador García-Ramos ◽  
Alejandro Pérez-Castilla ◽  
Antonio J. Morales-Artacho ◽  
Filipa Almeida ◽  
Paulino Padial ◽  
...  
Keyword(s):  
Maximum Velocity ◽  
Measurement Methods ◽  
Loading Conditions ◽  
Countermovement Jump ◽  
Mean Values ◽  
Velocity Transducer ◽  
Jump Exercise ◽  
Velocity Relationship ◽  
Force Velocity ◽  
The Mean

AbstractThis study aimed to compare force, velocity, and power output collected under different loads, as well as the force-velocity (F-V) relationship between three measurement methods. Thirteen male judokas were tested under four loading conditions (20, 40, 60, and 80 kg) in the countermovement jump (CMJ) exercise, while mechanical output data were collected by three measurement methods: the Samozino's method (SAM), a force platform (FP), and a linear velocity transducer (LVT). The variables of the linear F-V relationship (maximum force [F0], maximum velocity [V0], F-V slope, and maximum power [P0]) were determined. The results revealed that (1) the LVT overestimated the mechanical output as compared to the SAM and FP methods, especially under light loading conditions, (2) the SAM provided the lowest magnitude for all mechanical output, (3) the F-V relationships were highly linear either for the SAM (r = 0.99), FP (r = 0.97), and LVT (r = 0.96) methods, (4) the F-V slope obtained by the LVT differed with respect to the other methods due to a larger V0 (5.28 ± 1.48 m·s-1) compared to the SAM (2.98 ± 0.64 m·s-1) and FP (3.06 ± 0.42 m·s-1), and (5) the methods were significantly correlated for F0 and P0, but not for V0 or F-V slope. These results only support the accuracy of the SAM and FP to determine the F-V relationship during the CMJ exercise. The very large correlations of the SAM and LVT methods with respect to the FP (presumed gold-standard) for the mean values of force, velocity and power support their concurrent validity for the assessment of mechanical output under individual loads.

Frequency of various kinds of behaviour and emotional excitability in Thoroughbred yearlings trained by natural methods

2016 ◽  
Vol 72 (6) ◽  
pp. 389-392 ◽  
Author(s):  
Iwona Janczarek ◽  
Anna Stachurska ◽  
Izabela Wilk ◽  
Witold Kędzierski
Keyword(s):  
Heart Rhythm ◽  
Activity Level ◽  
Initial Training ◽  
Head Turning ◽  
Mean Values ◽  
High Position ◽  
Teeth Grinding ◽  
Parasympathetic System ◽  
Running Away ◽  
The Mean

The objective of the study was to determine the activity of the sympathetic and parasympathetic systems associated with various kinds of behaviour in Thoroughbred yearlings during initial training by natural methods. The initial training lasted approximately one hour a day for three successive days. Each day, the behaviour of each colt during the first 15 minutes of training was filmed. During training, a telemetric device was used to measure heart rhythm parameters: heart rate (HR per minute), which shows the activity level of the sympathetic system, and RMSSD (root mean square of two successive RR intervals in QRS curve; ms), illustrating the activity level of the parasympathetic system. On the basis of the film, the frequency of 10 most typical kinds of behaviour was estimated. The synchronization of the film with the heart rhythm parameters record made it possible to determine the mean values of these parameters for particular kinds of behaviour. The results show that on the successive days of training, the activity of the parasympathetic part of the autonomic system increased, and the frequency of reactions decreased. The heart rhythm parameters show that, among the typical reactions to training, four kinds of behaviour are desirable: turning the head towards the trainer, low position of the head, turning ears towards the trainer and licking the lips. Other kinds of behaviour, that is, running away, a high position of the head, vocalization, teeth grinding, tail movements to the sides and defecation, are undesirable. The highest excitability is associated with running away and a high position of the head, whereas the head turned towards the trainer and a low position of the head show that the horse is calm.

Ceruloplasmin is a Better Predictor of the Long-Term Prognosis Compared with Fibrinogen, CRP, and IL-6 in Patients with Severe Unstable Angina

Angiology ◽  
2008 ◽  
Vol 60 (1) ◽  
pp. 50-59 ◽  
Author(s):  
Antonios Ziakas ◽  
Stavros Gavrilidis ◽  
Efthimia Souliou ◽  
George Giannoglou ◽  
Ioannis Stiliadis ◽  
...  
Keyword(s):  
Unstable Angina ◽  
Cardiovascular Events ◽  
Time Course ◽  
C Reactive Protein ◽  
Mean Values ◽  
Reactive Protein ◽  
The Mean ◽  
Long Term Prognosis

Background. We investigated the time course and prognostic value of fibrinogen (Fib), C-reactive protein (CRP), interleukin-6 (IL-6), and ceruloplasmin (CP) in patients with severe unstable angina. Methods. All 4 substances were measured on admission and after 6, 12, 24, 48, and 72 hours, and after 7 days and 6 months in 40 patients with Braunwald's classification class IIIB unstable angina. Results. All recorded substances increased significantly; 15 patients had cardiovascular events during hospitalization and 11 patients during follow-up. The time course and the mean values of Fib, CRP, and IL-6 were similar in patients with and without complications both during hospitalization and follow-up. However, CP levels from 6 hours until 6 months were significantly higher in patients with complications during follow-up ( P < .05). Conclusions. Fib, CRP, IL-6, and CP levels alter in patients with severe unstable angina. However, only CP levels were related to 12-month follow-up prognosis.

Time course of changes in plasma vasopressin during atrial distension

1982 ◽  
Vol 60 (9) ◽  
pp. 1210-1218 ◽  
Author(s):  
J. R. Ledsome ◽  
N. Wilson ◽  
J. Ngsee
Keyword(s):  
Left Atrial ◽  
Time Course ◽  
Free Water ◽  
Urine Osmolality ◽  
Free Water Clearance ◽  
Mean Values ◽  
Plasma Vasopressin ◽  
The Mean ◽  
Plasma Arginine ◽  
Left Atrial Distension

Distension of the left atrium in chloralose anaesthetized dogs causes a diuresis and dilution of the urine. It has been reported previously that if distension of the atrium is maintained then urine flow reaches a peak after 50 min and then declines. A radioimmunoassay was used to measure plasma arginine vasopressin (AVP) at 10-min intervals before, during, and after atrial distension for 90 min. Plasma AVP decreased during atrial distension and did not increase until after the atrial distension was removed.Urine volume and free-water clearance increased and urine osmolality decreased, to reach maximum changes after 50 min. Although there was then a decline in some experiments, after reaching the peak changes, the mean values of the group did not show any statistically significant decline. Thus the urinary changes were also present for the 90 min of left atrial distension. The results are consistent with the hypothesis that the.diuretic response to left atrial distension is dependent upon decreased release of AVP from the neurohypophysis.

scholarly journals Light-activated ion channels in solitary photoreceptors of the scallop Pecten irradians.

1992 ◽  
Vol 99 (5) ◽  
pp. 747-769 ◽  
Author(s):  
E Nasi ◽  
M P Gomez
Keyword(s):  
Stimulus Intensity ◽  
Time Course ◽  
Single Channel ◽  
Divalent Cations ◽  
Cell Voltage ◽  
Resting Potential ◽  
Decay Kinetics ◽  
Whole Cell ◽  
The Mean ◽  
Single Channel Currents

Retinas from the scallop Pecten irradians were enzymatically dispersed, yielding a large number of isolated photoreceptors suitable for tight-seal recording. Whole-cell voltage clamp measurements demonstrated that the phototransducing machinery remained intact: quantum bumps could be elicited by dim illumination, while brighter flashes produced larger, smooth photocurrents. Single-channel currents specifically activated by light were recorded in cell-attached patches, and were almost exclusively confined to the rhabdomeric region. Their density is sufficiently high to account for the macroscopic photoresponse. Channel activation is graded with stimulus intensity in a range comparable to that of the whole-cell response, and can be recorded with illumination sufficiently dim to evoke only quantum bumps. Light-dependent channel openings are very brief, on average 1 ms or less at 20-22 degrees C, apparently not because of blockage by extracellular divalent cations. The mean open time does not change substantially with stimulus intensity. In particular, since dwell times are in the millisecond range even with the dimmest lights, the channel closing rate does not appear to be the rate-limiting step for the decay kinetics of discrete waves. The latency of the first opening after light onset is inversely related to light intensity, and the envelope of channel activity resembles the time course of the whole-cell photocurrent. Unitary currents are inward at resting potential, and have a reversal voltage similar to that of the macroscopic light response. Voltage modulates the activity of light-sensitive channels by increasing the opening rate and also by lengthening the mean open times as the patch is depolarized. The unitary conductance of the predominant class of events is approximately 48 pS, but at least one additional category of smaller-amplitude openings was observed. The relative incidence of large and small events does not appear to be related in a simple way to the state of adaptation of the cell.

Articulatory Behavior Pre and Post Full-Mouth Tooth Extraction and Alveoloplasty

1980 ◽  
Vol 23 (3) ◽  
pp. 630-645 ◽  
Author(s):  
Gerald Zimmermann ◽  
J.A. Scott Kelso ◽  
Larry Lander
Keyword(s):  
Control Subject ◽  
High Speed ◽  
Tooth Extraction ◽  
Kinematic Parameters ◽  
Experimental Conditions ◽  
Mean Values ◽  
Articulatory Movements ◽  
The Mean ◽  
Experimental Subjects ◽  
Normal Speech

High speed cinefluorography was used to track articulatory movements preceding and following full-mouth tooth extraction and alveoloplasty in two subjects. Films also were made of a control subject on two separate days. The purpose of the study was to determine the effects of dramatically altering the structural dimensions of the oral cavity on the kinematic parameters of speech. The results showed that the experimental subjects performed differently pre and postoperatively though the changes were in different directions for the two subjects. Differences in both means and variabilities of kinematic parameters were larger between days for the experimental (operated) subjects than for the control subject. The results for the Control subject also showed significant differences in the mean values of kinematic variables between days though these day-to-day differences could not account for the effects found pre- and postoperatively. The results of the kinematic analysis, particularly the finding that transition time was most stable over the experimental conditions for the operated subjects, are used to speculate about the coordination of normal speech.

Comparative Study of Intranasal, Subcutaneous and Intravenous Administration of Desamino-D-Arginine Vasopressin (DDAVP)

1986 ◽  
Vol 55 (01) ◽  
pp. 108-111 ◽  
Author(s):  
M Köhler ◽  
P Hellstern ◽  
C Miyashita ◽  
G von Blohn ◽  
E Wenzel
Keyword(s):  
Factor Viii ◽  
Von Willebrand Factor ◽  
Factor Xii ◽  
Additional Advantage ◽  
Mean Values ◽  
Routes Of Administration ◽  
The Mean ◽  
Von Willebrand ◽  
Willebrand Factor ◽  
Factor Antigen

SummaryThis study was performed to evaluate the influence of different routes of administration on the efficacy of DDAVP treatment. Ten healthy volunteers received DDAVP intranasally (i.n.), subcutaneously (s.c.) and intravenously (i.v.) in a randomized cross-over trial. Factor XII and high molecular weight (HMW)-kininogen levels increased only slightly after DDAVP administration. The mean increase of factor VIII: C was 3.1 (i. v.), 2.3 (s. c.), and 1.3 (i.n.) - fold over baseline. Ristocetin cofactor (von Willebrand factor antigen) increased 3.1 (2.5), 2.0 (2.3) and 1.2 (1.2) - fold over baseline mean values after i.v., s.c. and i.n. DDAVP, respectively. The half-disappearance time of factor VIII and von Willebrand factor (vWF) after DDAVP ranged from five (factor VIII: C) to eight hours (vWF). The mean increase of fibrinolytic activity was more pronounced after i.v. DDAVP. The antidiuretic effect was moderate with no apparent differences between the routes of application. This study provides further evidence that both i.v. and s.c. DDAVP administration result in an appropriate and reliable stimulation of haemostasis. An additional advantage of s. c. administration is its suitability for home treatment.

Comparative Study of effectiveness of mobilization with movement (MWM) and End range mobilization (ERM) techniques in frozen shoulder

2018 ◽  
Vol 4 (4) ◽  
pp. 519-522
Author(s):  
Jeyakumar S ◽  
Jagatheesan Alagesan ◽  
T.S. Muthukumar
Keyword(s):  
Range Of Motion ◽  
Frozen Shoulder ◽  
Type I ◽  
Mean Values ◽  
Functional Activities ◽  
Group A ◽  
The Mean ◽  
Group B

Background: Frozen shoulder is disorder of the connective tissue that limits the normal Range of motion of the shoulder in diabetes, frozen shoulder is thought to be caused by changes to the collagen in the shoulder joint as a result of long term Hypoglycemia. Mobilization is a therapeutic movement of the joint. The goal is to restore normal joint motion and rhythm. The use of mobilization with movement for peripheral joints was developed by mulligan. This technique combines a sustained application of manual technique “gliding” force to the joint with concurrent physiologic motion of joint, either actively or passively. This study aims to find out the effects of mobilization with movement and end range mobilization in frozen shoulder in Type I diabetics. Materials and Methods: 30 subjects both male and female, suffering with shoulder pain and clinically diagnosed with frozen shoulder was recruited for the study and divided into two groups with 15 patients each based on convenient sampling method. Group A patients received mobilization with movement and Group B patients received end range mobilization for three weeks. The outcome measurements were SPADI, Functional hand to back scale, abduction range of motion using goniometer and VAS. Results: The mean values of all parameters showed significant differences in group A as compared to group B in terms of decreased pain, increased abduction range and other outcome measures. Conclusion: Based on the results it has been concluded that treating the type 1 diabetic patient with frozen shoulder, mobilization with movement exercise shows better results than end range mobilization in reducing pain and increase functional activities and mobility in frozen shoulder.

A COMPARISON OF TWO METHODS FOR MEASUREMENT OF ALDOSTERONE SECRETION RATE IN MAN

1966 ◽  
Vol 53 (2) ◽  
pp. 177-188 ◽  
Author(s):  
P. Lund-Johansen ◽  
T. Thorsen ◽  
K. F. Støa
Keyword(s):  
Urinary Excretion ◽  
Normal Subjects ◽  
Secretion Rate ◽  
Aldosterone Secretion ◽  
Simple Method ◽  
Mean Values ◽  
Pathological Conditions ◽  
Significant Difference ◽  
Derivative Method ◽  
The Mean

ABSTRACT A comparison has been made between (A), a relatively simple method for the measurement of aldosterone secretion rate, based on paper chromatography and direct densitometry of the aldosterone spot and (B) a more elaborate isotope derivative method. The mean secretion rate in 9 normal subjects was 112 ± 26 μg per 24 hours (method A) and 135 ± 35 μg per 24 hours (method B). The »secretion rate« in one adrenalectomized subject after the intravenous injection of 250 μg of aldosterone was 230 μg per 24 hours (method A) and 294 μg per 24 hours (method B). There was no significant difference in the mean values, and correlation between the two methods was good (r = 0.80). It is concluded that the densitometric method is suitable for clinical purposes as well as research, being more rapid and less expensive than the isotope derivative method. Method A also measures the urinary excretion of the aldosterone 3-oxo-conjugate, which is of interest in many pathological conditions. The densitometric method is obviously the less sensitive and a prerequisite for its use is an aldosterone secretion of 20—30 μg per 24 hours. Lower values are, however, rare in adults.

Sign in / Sign up

Export Citation Format

Share Document