scholarly journals Effects of VDT tasks with a bright display at night on melatonin, core temperature, heart rate, and sleepiness

2003 ◽  
Vol 94 (5) ◽  
pp. 1773-1776 ◽  
Author(s):  
Shigekazu Higuchi ◽  
Yutaka Motohashi ◽  
Yang Liu ◽  
Mio Ahara ◽  
Yoshihiro Kaneko
Keyword(s):  
Heart Rate ◽  
Core Temperature ◽  
Rectal Temperature ◽  
Biological Clocks ◽  
Video Display ◽  
Healthy Male ◽  
Melatonin Concentration ◽  
Physiological Indicators ◽  
Nocturnal Increase ◽  
Salivary Melatonin

The effects of performing video display terminal (VDT) tasks with a bright display (BD) at night on nocturnal salivary melatonin concentration, rectal temperature, heart rate, and sleepiness were examined. Seven healthy male adults performed exciting VDT tasks with a BD and a dark display (DD) and boring VDT tasks with a BD and a DD from 2300 to 0200. The light intensities of the BD and DD were 45 and 15 lx at each subject's eye level, respectively. The exciting VDT task with both BD and DD significantly suppressed the nocturnal decrease in rectal temperature and heart rate and the nocturnal increase in sleepiness. The BD significantly suppressed the nocturnal decrease in rectal temperature during both exciting and boring VDT tasks. The nocturnal salivary melatonin concentration was significantly suppressed by the combination of the exciting task and BD. The results suggest that performing an exciting VDT task with a BD suppresses the nocturnal changes in melatonin concentration and other physiological indicators of human biological clocks.

Evidence against a 40°C core temperature threshold for fatigue in humans

2009 ◽  
Vol 107 (5) ◽  
pp. 1519-1525 ◽  
Author(s):  
Brett R. Ely ◽  
Matthew R. Ely ◽  
Samuel N. Cheuvront ◽  
Robert W. Kenefick ◽  
David W. DeGroot ◽  
...  
Keyword(s):  
Heart Rate ◽  
Field Study ◽  
Skin Temperature ◽  
Core Temperature ◽  
Rectal Temperature ◽  
Temperature Limit ◽  
Temperature Threshold ◽  
Elapsed Time ◽  
Skin Temperatures ◽  
Cardiovascular Strain

Evidence suggests that core temperatures of ∼40°C can induce fatigue, although this may be confounded by coincident elevations in skin temperatures and maximal cardiovascular strain. In an observational field study to examine core temperature threshold for fatigue, we investigated whether running performance is impaired when rectal temperature (Tre) is >40°C and skin temperature remains modest. Seventeen competitive runners (7/10 women/men: 8 km best 1,759 ± 78/1,531 ± 60 s) completed 8-km track time trials in cool (WBGT ∼13°C; n = 6), warm (WBGT ∼27°C; n = 4), or both ( n = 7) conditions. Tre, chest skin temperature, and heart rate were logged continuously; elapsed time was recorded every 200 m. Running velocity for Tre >40°C was compared with that for Tre <40°C for each runner. Changes in running velocity over the last 600 m were compared between runners with Tre >40°C and <40°C. Twelve runners achieved Tre >40.0°C with ≥600 m remaining (range 600–3,400 m). Average running velocity for Tre <40°C (282 ± 27 m/min) was not different from that for Tre >40°C (279 ± 28 m/min; P = 0.82). There were no differences in running velocity during the final 600 m between runners with final Tre >40°C or <40°C ( P = 0.16). Chest skin temperature ranged from 30 to 34°C, and heart rate was >95% of age-predicted maximum. Our observation that runners were able to sustain running velocity despite Tre >40°C is evidence against 40°C representing a “critical” core temperature limit to performance.

scholarly journals Effects of tramadol with tiletamine/zolazepam-xylazine as anaesthesia in cats

2013 ◽  
Vol 82 (2) ◽  
pp. 219-223
Author(s):  
Lin Li ◽  
Jing Dong ◽  
Dezhang Lu ◽  
Sheng Jiang ◽  
Dongqi Lin ◽  
...  
Keyword(s):  
Heart Rate ◽  
Respiratory Rate ◽  
Rectal Temperature ◽  
Analgesic Effect ◽  
Muscle Relaxation ◽  
Anaesthetic Technique ◽  
Anaesthetic Induction ◽  
Physiological Indicators

This study was conducted to investigate the effect of the combination of tiletamine/zolazepam-xylazine-tramadol (TZXT) in cats and to compare its efficacy as an anaesthetic technique with tiletamine/zolazepam-xylazine (TZX). Fourteen healthy thirteen-month-old cats of both sexes were immobilized by TZXT or TZX on two different occasions. The cats’ scores for immobilization, analgesia and baseline physiological indicators, heart rate, respiratory rate and rectal temperature, were recorded before and 5, 10, 15, 20, 30, 40, 50, 60, 80, 100 and 120 min after administration of TZXT or TZX. Animals in both groups became laterally recumbent within 3 min and physiological indicators changed after administration. These changes were within biologically acceptable limits; these measurements did not differ between the treatments. Induction and recovery quality in animals was better with TZXT than with TZX. Sedation, analgesia, muscle relaxation and posture scores was higher in TZXT group. During recovery, cats in TZXT group were more conscious than cats in TZX group. This study showed that in cats, addition of tramadol (T) to TZX improved the quality of anaesthetic induction and increased the analgesic effect without adversely affecting the physiological indicators. Thus tiletamine/zolazepam-xylazine-tramadol shows to be more suitable for cat anaesthesia.

scholarly journals Energy Supplementation during the Last Third of Gestation Improves Mother–Young Bonding in Goats

Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 287
Author(s):  
Juan M. Vázquez-García ◽  
Gregorio Álvarez-Fuentes ◽  
Héctor O. Orozco-Gregorio ◽  
Juan C. García-López ◽  
Milagros González-Hernández ◽  
...  
Keyword(s):  
Heart Rate ◽  
Birth Weight ◽  
Respiratory Rate ◽  
Rectal Temperature ◽  
First Feeding ◽  
Labor Duration ◽  
Daily Energy ◽  
Energy Supplementation ◽  
Birth Body Weight ◽  
Birth Type

We tested whether maternal energy supplementation during the last third of gestation improves birth weight, neonatal wellbeing, and mother–young bonding. Thirty-six pregnant French Alpine goats were randomly allocated among three nutritional treatments for the last third of pregnancy: (i) Control, fed alfalfa (T-0; n = 12); (ii) alfalfa + 150 g/head daily energy concentrate (T-150; n = 12); (iii) alfalfa + 300 g/head daily energy concentrate (T-300; n = 12). At birth, we collected progeny data on birth weight, birth type, sex, rectal temperature, heart rate, respiratory rate, time to standing, time to udder connection, and time to first feeding. For the dams, we collected data on the duration of labor, time to clean the progeny, and time to allow first suckling. At birth, body weight, rectal temperature, heart rate, and the respiratory rate did not differ among treatments (p > 0.05). In the dams, labor duration was not affected by the treatments (p > 0.05). The T-150 dams were faster to clean the newborn and allow first suckling (p < 0.05). The T-150 progeny were faster to stand and the T-300 progeny were faster to connect to the udder (p < 0.05). We conclude that energy supplementation of the dam during the last third of gestation does not affect the birth weight of the progeny, but enhances the mother–young bonding.

Maximum Eye Temperature in the Assessment of Training in Racehorses: Correlations With Salivary Cortisol Concentration, Rectal Temperature, and Heart Rate

2016 ◽  
Vol 45 ◽  
pp. 39-45 ◽  
Author(s):  
Maria Soroko ◽  
Kevin Howell ◽  
Anna Zwyrzykowska ◽  
Krzysztof Dudek ◽  
Paulina Zielińska ◽  
...  
Keyword(s):  
Heart Rate ◽  
Rectal Temperature ◽  
Salivary Cortisol ◽  
Cortisol Concentration ◽  
Eye Temperature

Hypothalamic paraventricular nucleus is critical for renal vasoconstriction elicited by elevations in body temperature

2008 ◽  
Vol 294 (2) ◽  
pp. F309-F315 ◽  
Author(s):  
Joo Lee Cham ◽  
Emilio Badoer
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Blood Flow ◽  
Renal Blood Flow ◽  
Core Temperature ◽  
Paraventricular Nucleus ◽  
Hypothalamic Paraventricular Nucleus ◽  
Body Core Temperature ◽  
Control Group ◽  
Body Core

Redistribution of blood from the viscera to the peripheral vasculature is the major cardiovascular response designed to restore thermoregulatory homeostasis after an elevation in body core temperature. In this study, we investigated the role of the hypothalamic paraventricular nucleus (PVN) in the reflex decrease in renal blood flow that is induced by hyperthermia, as this brain region is known to play a key role in renal function and may contribute to the central pathways underlying thermoregulatory responses. In anesthetized rats, blood pressure, heart rate, renal blood flow, and tail skin temperature were recorded in response to elevating body core temperature. In the control group, saline was microinjected bilaterally into the PVN; in the second group, muscimol (1 nmol in 100 nl per side) was microinjected to inhibit neuronal activity in the PVN; and in a third group, muscimol was microinjected outside the PVN. Compared with control, microinjection of muscimol into the PVN did not significantly affect the blood pressure or heart rate responses. However, the normal reflex reduction in renal blood flow observed in response to hyperthermia in the control group (∼70% from a resting level of 11.5 ml/min) was abolished by the microinjection of muscimol into the PVN (maximum reduction of 8% from a resting of 9.1 ml/min). This effect was specific to the PVN since microinjection of muscimol outside the PVN did not prevent the normal renal blood flow response. The data suggest that the PVN plays an essential role in the reflex decrease in renal blood flow elicited by hyperthermia.

scholarly journals Monitoring of physiological and blood parameters during perinatal and neonatal period in calves

2010 ◽  
Vol 62 (1) ◽  
pp. 1-12 ◽  
Author(s):  
G. Piccione ◽  
S. Casella ◽  
P. Pennisi ◽  
C. Giannetto ◽  
A. Costa ◽  
...  
Keyword(s):  
Heart Rate ◽  
Respiratory Rate ◽  
Total Cholesterol ◽  
Rectal Temperature ◽  
Neonatal Period ◽  
Blood Parameters ◽  
External Jugular Vein ◽  
Individual Values ◽  
Functional Development ◽  
Adaptation Processes

Rectal temperature, heart and respiratory rates, and the course of some blood parameters were monitored in calves during perinatal and neonatal periods. The study was carried out on eight Limousine calves. From all subjects, rectal temperature, heart rate, and respiratory rate were measured. Blood samples were taken at the same hour (9am) from the external jugular vein, and then centrifuged and stored until analyses. By means of an UV spectrophotometer, the following blood parameters were assessed for each subject: total protein, total cholesterol, triglycerides, glucose, non-esterified fatty acids (NEFA), urea, creatinine, cholinesterase, lactate dehydrogenase (LDH), hydroxybutirate, glutamate pyruvate transaminases (GPT), glutamate oxalacetate transaminases (GOT), direct and total bilirubin, magnesium, iron, potassium, phosphorus, chloride and sodium. The results showed a significant effect of days of life (P<0.05) only on total cholesterol, creatinine and GOT during the first week of life and a significant effect of days of life on rectal temperature, heart rate, respiratory rate, total cholesterol, NEFA, creatinina, and GOT during the first month of life. A correlation among individual values for postnatal age (days of life) and heart rate in calves during the first month of life was observed. In conclusion, modifications of studied parameters could be attributed to functional development of calves in neonatal period and contribute to the knowledge of adaptation processes in calf during the first week and the first month of life resulting useful for the diagnosis and treatment of any neonatal diseases.

scholarly journals Estimating Resting Core Temperature Using Heart Rate

2018 ◽  
Vol 1 (2) ◽  
pp. 79-86 ◽  
Author(s):  
David P. Looney ◽  
Mark J. Buller ◽  
Andrei V. Gribok ◽  
Jayme L. Leger ◽  
Adam W. Potter ◽  
...  
Keyword(s):  
Heart Rate ◽  
Core Temperature ◽  
Estimation Algorithm ◽  
Quadratic Equation ◽  
Estimation Accuracy ◽  
Future Research ◽  
Accuracy And Precision ◽  
Military Populations ◽  
Thermal Work ◽  
Ct Data

ECTemp™ is a heart rate (HR)-based core temperature (CT) estimation algorithm mainly used as a real-time thermal-work strain indicator in military populations. ECTemp™ may also be valuable for resting CT estimation, which is critical for circadian rhythm research. This investigation developed and incorporated a sigmoid equation into ECTemp™ to better estimate resting CT. HR and CT data were collected over two calorimeter test trials from 16 volunteers (age, 23 ± 3 yrs; height, 1.72 ± 0.07 m; body mass, 68.5 ± 8.1 kg) during periods of sleep and inactivity. Half of the test trials were combined with ECTemp™’s original development dataset to train the new sigmoid model while the other was used for model validation. Models were compared by their estimation accuracy and precision. While both models produced accurate CT estimates, the sigmoid model had a smaller bias (−0.04 ± 0.26°C vs. −0.19 ± 0.29°C) and root mean square error (RMSE; 0.26°C vs. 0.35°C). ECTemp™ is a validated HR-based resting CT estimation algorithm. The new sigmoid equation corrects lower CT estimates while producing nearly identical estimates to the original quadratic equation at higher CT. The demonstrated accuracy of ECTemp™ encourages future research to explore the algorithm’s potential as a non-invasive means of tracking CT circadian rhythms.

Sign in / Sign up

Export Citation Format

Share Document