Open Access. Powered by Scholars. Published by Universities.®

Medicine and Health Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 16 of 16

Full-Text Articles in Medicine and Health Sciences

Physiological And Behavioural Evaluation Of Common Anaesthesia Practices In The Rainbow Trout, Kieran C. Pounder, Jennifer L. Mitchell, Jack S. Thomson, Tom G. Pottinger, Lynne U. Sneddon Oct 2019

Physiological And Behavioural Evaluation Of Common Anaesthesia Practices In The Rainbow Trout, Kieran C. Pounder, Jennifer L. Mitchell, Jack S. Thomson, Tom G. Pottinger, Lynne U. Sneddon

Lynne Sneddon, PhD

Anaesthetic drugs are commonly administered to fish in aquaculture, research and veterinary contexts. Anaesthesia causes temporary absence of consciousness and may reduce the stress and/or pain associated with handling and certain invasive procedures. The rainbow trout (Oncorhynchus mykiss) is a widely-used model species with relevance to both aquaculture and natural ecosystems. This study sought to establish the relative acute impact of commonly used anaesthetics on rainbow trout when used for anaesthesia or euthanasia by exploring their effects on aversion behaviour and stress physiology. Five widely used anaesthetics were investigated at two concentrations reflective of common laboratory practises: MS-222, benzocaine, 2-phenoxyethanol, …


Relationship Between The Cortisol-Estradiol Phase Difference And Affect In Women, Karyn Butler Jun 2019

Relationship Between The Cortisol-Estradiol Phase Difference And Affect In Women, Karyn Butler

Karyn Butler, PhD, CNM

Affective disorders impact women’s health, with a lifetime prevalence of over twelve per cent. They have been correlated with reproductive cycle factors, under the regulation of hormonal circadian rhythms. In affective disorders, circadian rhythms may become desynchronized. The circadian rhythms of cortisol and estradiol may play a role in affective disorders. The purpose of this study was to explore the temporal relationship between the rhythms of cortisol and estradiol and its relationship to affect. It was hypothesized that a cortisol-estradiol phase difference (PD) exists that correlates with optimal affect. A small scale, comparative, correlational design was used to test the …


Resting Hormone Alterations And Injuries: Block Vs. Dup Weight-Training Among D-1 Track And Field Athletes, Keith B. Painter, G. Gregory Haff, N. Travis Triplett, Charles Stuart, Guy Hornsby, Mike W. Ramsey, Caleb D. Bazyler, Michael H. Stone Feb 2019

Resting Hormone Alterations And Injuries: Block Vs. Dup Weight-Training Among D-1 Track And Field Athletes, Keith B. Painter, G. Gregory Haff, N. Travis Triplett, Charles Stuart, Guy Hornsby, Mike W. Ramsey, Caleb D. Bazyler, Michael H. Stone

Michael W. Ramsey

Daily undulating periodization (DUP), using daily alterations in repetitions, has been advocated as a superior method of resistance training, while traditional forms of programming for periodization (Block) have been questioned. Nineteen Division I track and field athletes were assigned to either a 10-week Block or DUP training group. Year and event were controlled. Over the course of the study, there were four testing sessions, which were used to evaluate a variety of strength characteristics, including maximum isometric strength, rate of force development, and one repetition maximum (1RM). Although, performance trends favored the Block group for strength and rate of force …


Resting Hormone Alterations And Injuries: Block Vs. Dup Weight-Training Among D-1 Track And Field Athletes, Keith B. Painter, G. Gregory Haff, N. Travis Triplett, Charles Stuart, Guy Hornsby, Mike W. Ramsey, Caleb D. Bazyler, Michael H. Stone Feb 2019

Resting Hormone Alterations And Injuries: Block Vs. Dup Weight-Training Among D-1 Track And Field Athletes, Keith B. Painter, G. Gregory Haff, N. Travis Triplett, Charles Stuart, Guy Hornsby, Mike W. Ramsey, Caleb D. Bazyler, Michael H. Stone

Caleb D. Bazyler

Daily undulating periodization (DUP), using daily alterations in repetitions, has been advocated as a superior method of resistance training, while traditional forms of programming for periodization (Block) have been questioned. Nineteen Division I track and field athletes were assigned to either a 10-week Block or DUP training group. Year and event were controlled. Over the course of the study, there were four testing sessions, which were used to evaluate a variety of strength characteristics, including maximum isometric strength, rate of force development, and one repetition maximum (1RM). Although, performance trends favored the Block group for strength and rate of force …


The Relative Value Of Measures Of Omega-3 Index, Perceived Stress, Cortisol And Sleep Time In Identifying Depression Among A Cohort Of Australian Adolescents, Ross Grant, Ayse Bilgin, Jade Guest, Margaret J. Morris, Manohar Garg, Robyn Pearce Oct 2016

The Relative Value Of Measures Of Omega-3 Index, Perceived Stress, Cortisol And Sleep Time In Identifying Depression Among A Cohort Of Australian Adolescents, Ross Grant, Ayse Bilgin, Jade Guest, Margaret J. Morris, Manohar Garg, Robyn Pearce

Robyn Pearce

Objective: To assess the relative prognostic value of 11 variables including, omega-3, perceived stress, cortisol and sleep duration, in predicting adolescent depression. Design, Setting and Participants: A cross-sectional study of 444 healthy adolescents aged 16-18 years, from 10 schools within the Northern Sydney and Central Coast regions of New South Wales, Australia. Participants provided blood and saliva samples and completed questionnaires. Statistical classification methods were used to model the relationships between the predictors and depression. Main Outcome Measures: relative predictive value of each variable in correctly classifying depression. Results: 6% of boys and 9% of girls were categorised as experiencing …


Social Motivation Is Associated With Elevated Salivary Cortisol In Boys With An Asd, Vicki Bitsika, Christopher Sharpley, Linda Agnew, Nicholas Andronicos Nov 2015

Social Motivation Is Associated With Elevated Salivary Cortisol In Boys With An Asd, Vicki Bitsika, Christopher Sharpley, Linda Agnew, Nicholas Andronicos

Vicki Bitsika

Because social communication difficulties and stress are common in children with an ASD, and because it has been hypothesised that the two are related, the association between these two variables was investigated in a sample of 90 boys with an ASD and who were aged between 6 years and 12 years of age. The Social Responsiveness Scale (SRS) was completed by the parents of these boys about their sons, plus salivary cortisol samples were collected from the boys. Results indicated that only one aspect of the boys' SRS was significantly correlated with cortisol—Social Motivation (SM). Factor analyses revealed two discrete …


Age-Related Differences In The Association Between Stereotypic Behaviour And Salivary Cortisol In Young Males With An Autism Spectrum Disorder, Vicki Bitsika, Christopher Sharpley, Linda Agnew, Nicholas Andronicos Nov 2015

Age-Related Differences In The Association Between Stereotypic Behaviour And Salivary Cortisol In Young Males With An Autism Spectrum Disorder, Vicki Bitsika, Christopher Sharpley, Linda Agnew, Nicholas Andronicos

Vicki Bitsika

To identify if age influenced the relationship between one of the central symptoms of Autism Spectrum Disorder (ASD) and physiological stress, the association between stereotypic behaviour (SB) and stress-related cortisol concentrations was examined in a sample of 150 young males with an ASD. Parent-rated SB was significantly correlated with cortisol concentrations for boys aged 6 years to 12 years but not for adolescents aged 13 years to 18 years. This age-related difference in this association was not a function of cortisol concentrations but was related to differences in SB across these two age groups. IQ did not have a significant …


Which Aspects Of Sensory Features Are Associated With Elevated Cortisol Concentrations In Boys With An Autism Spectrum Disorder?, Vicki Bitsika, Christopher Sharpley, Nicholas Andronicos, Linda Agnew, Richard Mills Oct 2015

Which Aspects Of Sensory Features Are Associated With Elevated Cortisol Concentrations In Boys With An Autism Spectrum Disorder?, Vicki Bitsika, Christopher Sharpley, Nicholas Andronicos, Linda Agnew, Richard Mills

Vicki Bitsika

Difficulties in Sensory Features (SF) have been included in the most recent diagnostic processes for Autism Spectrum Disorder (ASD) and are more common in children with an ASD than their non-ASD peers. In addition, these difficulties with SF have been suggested as causing elevated stress and concentrations of salivary cortisol in young people with an ASD. However, previous studies have not examined the specific aspects of SF that are associated with elevated cortisol and that was the focus of this study with 135 boys with an ASD aged 6–18 years. The boys’ mothers assessed their sons’ SF with the Sensory …


Eight-Month Test-Retest Agreement In Morning Salivary Cortisol, Self- And Parent-Rated Anxiety In Boys With An Autism Spectrum Disorder, Christopher Sharpley, Vicki Bitsika, Linda Agnew, Nicholas Andronicos Oct 2015

Eight-Month Test-Retest Agreement In Morning Salivary Cortisol, Self- And Parent-Rated Anxiety In Boys With An Autism Spectrum Disorder, Christopher Sharpley, Vicki Bitsika, Linda Agnew, Nicholas Andronicos

Vicki Bitsika

The agreement over time in morning salivary cortisol concentrations and also self- and parent-rated anxiety was investigated in a sample of 16 boys with an ASD. Cortisol and anxiety data were collected eight months apart. Results indicated that there were significant correlations between each pair of measures from the two occasions, suggesting that cortisol concentrations and anxiety did not vary much at all over that time, challenging the assumption that cortisol needs to be measured over multiple days to obtain reliable data from children with an ASD. Implications for research into the ways these children respond to chronic stressors are …


Plasticity Of Boldness In Rainbow Trout, Oncorhynchus Mykiss: Do Hunger And Predation Influence Risk-Taking Behaviour?, Jack S. Thomson, Phillip C. Watts, Tom G. Pottinger, Lynne U. Sneddon Jul 2015

Plasticity Of Boldness In Rainbow Trout, Oncorhynchus Mykiss: Do Hunger And Predation Influence Risk-Taking Behaviour?, Jack S. Thomson, Phillip C. Watts, Tom G. Pottinger, Lynne U. Sneddon

Lynne U. Sneddon, Ph.D.

Boldness, a measure of an individual's propensity for taking risks, is an important determinant of fitness but is not necessarily a fixed trait. Dependent upon an individual's state, and given certain contexts or challenges, individuals may be able to alter their inclination to be bold or shy in response. Furthermore, the degree to which individuals can modulate their behaviour has been linked with physiological responses to stress. Here we attempted to determine whether bold and shy rainbow trout, Oncorhynchus mykiss, can exhibit behavioural plasticity in response to changes in state (nutritional availability) and context (predation threat). Individual trout were initially …


The Effects Of Acute And Chronic Hypoxia On Cortisol, Glucose And Lactate Concentrations In Different Populations Of Three-Spined Stickleback, E. A. O'Connor, T. G. Pottinger, L. U. Sneddon Apr 2015

The Effects Of Acute And Chronic Hypoxia On Cortisol, Glucose And Lactate Concentrations In Different Populations Of Three-Spined Stickleback, E. A. O'Connor, T. G. Pottinger, L. U. Sneddon

Lynne Sneddon, PhD

The response of individuals from three different populations of three-spined sticklebacks to acute and chronic periods of hypoxia (4.4 kPa DO, 2.2 mg l-1) were tested using measures of whole-body (WB) cortisol, glucose and lactate. Although there was no evidence of a neuroendocrine stress response to acute hypoxia, fish from the population least likely to experience hypoxia in their native habitat had the largest response to low oxygen, with significant evidence of anaerobic glycolysis after two hours of hypoxia. However, there was no measurable effect of a more prolonged period (seven days) of hypoxia on any of the fish in …


Physiological And Genetic Correlates Of Boldness: Characterising The Mechanisms Of Behavioural Variation In Rainbow Trout, Oncorhynchus Mykiss, Jack S. Thomson, Phillip C. Watts, Tom G. Pottinger, Lynne U. Sneddon Apr 2015

Physiological And Genetic Correlates Of Boldness: Characterising The Mechanisms Of Behavioural Variation In Rainbow Trout, Oncorhynchus Mykiss, Jack S. Thomson, Phillip C. Watts, Tom G. Pottinger, Lynne U. Sneddon

Lynne Sneddon, PhD

Bold, risk-taking animals have previously been putatively linked with a proactive stress coping style whereas it is suggested shyer, risk-averse animals exhibit a reactive coping style. The aim of this study was to investigate whether differences in the expression of bold-type behaviour were evident within and between two lines of rainbow trout, Oncorhynchus mykiss, selectively bred for a low (LR) or high (HR) endocrine response to stress, and to link boldness and stress responsiveness with the expression of related candidate genes. Boldness was determined in individual fish over two trials by measuring the latency to approach a novel object. Differences …


Neuromuscular And Endocrine Responses Of Elite Players During An Australian Rules Football Season, Stuart Cormack, Robert Newton, Michael Mcguigan, Prue Cormie Mar 2014

Neuromuscular And Endocrine Responses Of Elite Players During An Australian Rules Football Season, Stuart Cormack, Robert Newton, Michael Mcguigan, Prue Cormie

Prue Cormie

Purpose: To examine variations in neuromuscular and hormonal status and their relationship to performance throughout a season of elite Australian Rules Football (ARF). Methods: Fifteen elite ARF players performed a single jump (CMJ1) and 5 repeated countermovement jumps (CMJ5), and provided saliva samples for the analysis of cortisol (C) and testosterone (T) before the season commenced (Pre) and during the 22-match season. Magnitudes of effects were reported with the effect size (ES) statistic. Correlations were performed to analyze relationships between assessment variables and match time, training load, and performance. Results: CMJ1Flight time:Contraction time was substantially reduced on 60% of measurement …


Biochemical And Endocrine Responses To Impact And Collision During Elite Rugby League Match Play, Christopher Mclellan, Dale Lovell, Gregory Gass Nov 2012

Biochemical And Endocrine Responses To Impact And Collision During Elite Rugby League Match Play, Christopher Mclellan, Dale Lovell, Gregory Gass

Chris McLellan

The purpose of this study was to investigate the relationship between the prematch and short-term postmatch biochemical and endocrine responses to the intensity, number, and distribution of impacts associated with collisions during elite Rugby League match play. Seventeen elite male Rugby League players each provided blood and saliva samples 24 hours prematch, 30 minutes prematch, 30 minutes postmatch, and then at 24-hour intervals for a period of 5 days postmatch to determine plasma creatine kinase concentration ([CK]) and salivary cortisol concentration ([sCort]). The intensity, number, and distribution of impact forces experienced by players during match play were recorded using portable …


Markers Of Postmatch Fatigue In Professional Rugby League Players, Christ Mclellan, Dale Lovell, Gregory Gass Nov 2012

Markers Of Postmatch Fatigue In Professional Rugby League Players, Christ Mclellan, Dale Lovell, Gregory Gass

Chris McLellan

The aim of the present study was to identify neuromuscular, biochemical, and endocrine markers of fatigue after Rugby League match play. Seventeen elite Rugby League players were monitored for a single match. Peak rate of force development (PRFD), peak power (PP), and peak force (PF) were measured during a countermovement jump (CMJ) on a force plate pre and postmatch play. Saliva and blood samples were collected 24 hours prematch, 30 minutes prematch, 30 minutes postmatch, and then at 24-hour intervals for a period of 120 hours to determine plasma creatine kinase concentration ([CK]) and salivary cortisol concentration ([sCort]). There were …


Impaired Nocturnal Melatonin In Acute Phase Of Ischaemic Stroke: Cross-Sectional Matched Case-Control Analysis., Penka A Atanassova, Dora Terzieva, Borislav Dimitrov Mar 2012

Impaired Nocturnal Melatonin In Acute Phase Of Ischaemic Stroke: Cross-Sectional Matched Case-Control Analysis., Penka A Atanassova, Dora Terzieva, Borislav Dimitrov

Borislav D Dimitrov

Quantitative data on melatonin in stroke patients are scarce. A gender- and age-matched cross-sectional case-control study in 33 patients with ischaemic stroke was performed and associations between nocturnal melatonin and other factors (e.g. cortisol) were evaluated. Clinical and laboratory (e.g. melatonin and cortisol) measurements (03.00 h and 08.00 h) with statistical techniques [e.g. multifactorial regressions, receiver operating characteristic (ROC) curve and curvilinear estimations] were used. We identified mean value and 95% confidence interval (CI) (69.70 pg/ml; 95% CI = 53.86-85.54) for control levels of nocturnal melatonin in healthy subjects. The patients with stroke had lower melatonin (48.1 +/- 35.9 pg/ml) …