ORCID Profile
0000-0002-2361-3729
Current Organisation
University of South Australia
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
Publisher: Hindawi Limited
Date: 2012
DOI: 10.1155/2012/132830
Abstract: BACKGROUND: A central model for chronic tension-type headache (CTH) posits that stress contributes to headache, in part, by aggravating existing hyperalgesia in CTH sufferers. The prediction from this model that pain sensitivity mediates the relationship between stress and headache activity has not yet been examined. OBJECTIVE: To determine whether pain sensitivity mediates the relationship between stress and prospective headache activity in CTH sufferers. METHOD: Self-reported stress, pain sensitivity and prospective headache activity were measured in 53 CTH sufferers recruited from the general population. Pain sensitivity was modelled as a mediator between stress and headache activity, and tested using a nonparametric bootstrap analysis. RESULTS: Pain sensitivity significantly mediated the relationship between stress and headache intensity. CONCLUSIONS: The results of the present study support the central model for CTH, which posits that stress contributes to headache, in part, by aggravating existing hyperalgesia in CTH sufferers. Implications for the mechanisms and treatment of CTH are discussed.
Publisher: Elsevier BV
Date: 05-2019
DOI: 10.1016/J.AAP.2018.01.026
Abstract: Self-assessment is the most common method for monitoring performance and safety in the workplace. However, discrepancies between subjective and objective measures have increased interest in physiological assessment of performance. In a double-blind placebo-controlled study, 23 healthy adults were randomly assigned to either a placebo (n = 11 5 F, 6 M) or caffeine condition (n = 12 4 F, 8 M) while undergoing 50 h (i.e. two days) of total sleep deprivation. In previous work, higher salivary alpha-amylase (sAA) levels were associated with improved psychomotor vigilance and simulated driving performance in the placebo condition. In this follow-up article, the effects of strategic caffeine administration on the previously reported diurnal profiles of sAA and performance, and the association between sAA and neurobehavioural performance were investigated. Participants were given a 10 h baseline sleep opportunity (monitored via standard polysomnography techniques) prior to undergoing sleep deprivation (total sleep time: placebo = 8.83 ± 0.48 h caffeine = 9.01 ± 0.48 h). During sleep deprivation, caffeine gum (200 mg) was administered at 01:00 h, 03:00 h, 05:00 h, and 07:00 h to participants in the caffeine condition (n = 12). This strategic administration of caffeine gum (200 mg) has been shown to be effective at maintaining cognitive performance during extended wakefulness. Saliva s les were collected, and psychomotor vigilance and simulated driving performance assessed at three-hour intervals throughout wakefulness. Caffeine effects on diurnal variability were compared with previously reported findings in the placebo condition (n = 11). The impact of caffeine on the circadian profile of sAA coincided with changes in neurobehavioural performance. Higher sAA levels were associated with improved performance on the psychomotor vigilance test during the first 24 h of wakefulness in the caffeine condition. However, only the association between sAA and response speed (i.e. reciprocal-transform of mean reaction time) was consistent across both days of sleep deprivation. The association between sAA and driving performance was not consistent across both days of sleep deprivation. Results show that the relationship between sAA and reciprocal-transform of mean reaction time on the psychomotor vigilance test persisted in the presence of caffeine, however the association was relatively weaker as compared with the placebo condition.
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C5AN01754H
Abstract: Surface assisted laser desorption/ionization mass spectrometry (SALDI-MS) with porous silicon microparticles was used for the all-in-one extraction and detection of illicit drugs from saliva, urine and plasma.
Publisher: Elsevier BV
Date: 05-2019
DOI: 10.1016/J.AAP.2018.01.007
Abstract: Technology-supported methods for sleep recording are becoming increasingly affordable. Sleep history feedback may help with fatigue-related decision making - Should I drive? Am I fit for work? This study examines a "sleep tank" model (SleepTank
Publisher: Oxford University Press (OUP)
Date: 06-2004
DOI: 10.1105/TPC.160630
Publisher: Informa UK Limited
Date: 21-06-2017
DOI: 10.1080/07420528.2017.1335318
Abstract: Eating during the night may increase the risk for obesity and type 2 diabetes in shift workers. This study examined the impact of either eating or not eating a meal at night on glucose metabolism. Participants underwent four nights of simulated night work (SW1-4, 16:00-10:00 h, <50 lux) with a daytime sleep opportunity each day (10:00-16:00 h, <3 lux). Healthy males were assigned to an eating at night (NE n = 4, meals 07:00, 19:00 and 01:30 h) or not eating at night (NEN n = 7, meals 07:00 h, 09:30, 16:10 and 19:00 h) condition. Meal tolerance tests were conducted post breakfast on pre-night shift (PRE), SW4 and following return to day shift (RTDS), and glucose and insulin area under the curve (AUC) were calculated. Mixed-effects ANOVAs were used with fixed effects of condition and day, and their interactions, and a random effect of subject identifier on the intercept. Fasting glucose and insulin were not altered by day or condition. There were significant effects of day and condition × day (both p < 0.001) for glucose AUC, with increased glucose AUC observed solely in the NE condition from PRE to SW4 (p = 0.05) and PRE to RTDS (p < 0.001). There was also a significant effect of day (p = 0.007) but not condition × day (p = 0.825) for insulin AUC, with increased insulin from PRE to RTDS in both eating at night (p = 0.040) and not eating at night (p = 0.006) conditions. Results in this small, healthy s le suggest that not eating at night may limit the metabolic consequences of simulated night work. Further study is needed to explore whether matching food intake to the biological clock could reduce the burden of type 2 diabetes in shift workers.
Publisher: Hindawi Limited
Date: 2013
DOI: 10.1155/2013/796161
Abstract: BACKGROUND: Tension-type headache is the most common form of headache and its chronic form, chronic tension-type headache (CTTH), is one of the most difficult to treat. The etiology of CTTH is not well understood, but is believed to be multifactorial and to vary among in iduals. In the present study, the authors sought to identify common mechanisms of CTTH pathology. Empirical studies have implicated various immunomodulatory cytokines as mediators of chronic pain disorders, including CTTH. OBJECTIVES: To determine the role of peripheral cytokines and genetic factors in the development of CTTH. METHODS: A panel of cytokines hypothesized to play a role in the pathogenesis of CTTH was measured using cytometric bead arrays and ELISAs in 56 in iduals with CTTH and 42 healthy control participants between 18 and 65 years of age. RESULTS: Levels of interleukin (IL)-1β were significantly elevated in participants diagnosed with CTTH relative to healthy controls, while IL-18 levels were found to be significantly elevated in men with CTTH. Because the levels of these immune mediators were increased in the apparent absence of injury or infection, the authors sought to determine whether genetic changes were responsible for fluctuations in cytokine levels. Polymerase chain reaction and restriction fragment length polymorphism analyses were used to determine in idual genotypes at key single nucleotide polymorphism positions in the IL-1B gene. No association was observed between CTTH and single nucleotide polymorphisms in the IL-1β gene. CONCLUSIONS: These findings suggest that increases in key proinflammatory cytokine levels are associated with CTTH and the pathology of the disorder involves sterile neurovascular inflammation.
Publisher: Elsevier BV
Date: 06-2016
DOI: 10.1016/J.PBB.2016.03.011
Abstract: The current study investigated the effects of repeated caffeine administration on performance and subjective reports of sleepiness and fatigue during 50h extended wakefulness. Twenty-four, non-smokers aged 22.5±2.9y (mean±SD) remained awake for two nights (50h) in a controlled laboratory environment. During this period, 200mg of caffeine or placebo gum was administered at 01:00, 03:00, 05:00 and 07:00 on both nights (total of 800mg/night). Neurobehavioral performance and subjective reports were assessed throughout the wake period. Caffeine improved performance compared to placebo, but did not affect overall ratings of subjective sleepiness and fatigue. Performance and sleepiness worsened with increasing time awake for both conditions. However, caffeine slowed performance impairments such that after 50h of wakefulness performance was better following caffeine administration compared to placebo. Caffeine also slowed the increase in subjective sleepiness and performance ratings, but only during the first night of wakefulness. After two nights of sleep deprivation, there was no difference in sleepiness ratings between the two conditions. These results demonstrate that strategic administration of caffeine effectively mitigates performance impairments associated with 50h wakefulness but does not improve overall subjective assessments of sleepiness, fatigue and performance. Results indicate that while performance impairment is alleviated, in iduals may continue to report feelings of sleepiness. In iduals who use caffeine as a countermeasure in sustained operations may feel as though caffeine is not effective despite impairments in objective performance being largely mitigated.
Publisher: Springer Science and Business Media LLC
Date: 17-02-2021
DOI: 10.1038/S41598-021-83504-6
Abstract: Caffeine is widely used to promote alertness and cognitive performance under challenging conditions, such as sleep loss. Non-digestive modes of delivery typically reduce variability of its effect. In a placebo-controlled, 50-h total sleep deprivation (TSD) protocol we administered four 200 mg doses of caffeine-infused chewing-gum during night-time circadian trough and monitored participants' drowsiness during task performance with infra-red oculography. In addition to the expected reduction of sleepiness, caffeine was found to disrupt its degrading impact on performance errors in tasks ranging from standard cognitive tests to simulated driving. Real-time drowsiness data showed that caffeine produced only a modest reduction in sleepiness (compared to our placebo group) but substantial performance gains in vigilance and procedural decisions, that were largely independent of the actual alertness dynamics achieved. The magnitude of this disrupting effect was greater for more complex cognitive tasks.
Publisher: Elsevier BV
Date: 05-2019
DOI: 10.1016/J.PHYSBEH.2019.02.004
Abstract: Sleep loss is one of the most common causes of accidents and errors in operational environments. Currently, no single method satisfies all of the requisite criteria of an effective system for assessing the risk of injury prior to safety being compromised. Research has concentrated towards the development of a biomarker for in idualized assessment of sleepiness-related deficits in neurobehavioral alertness, with salivary alpha-amylase (sAA) recently reported as a potential biomarker during acute total sleep deprivation. The present study extends on previous research by investigating the association between sAA and neurobehavioral alertness during simulated night-shift work, during in iduals are required to work at night when biological processes are strongly promoting sleep and sleep during the day when endogenous processes are promoting wakefulness. In a laboratory-controlled environment, 10 healthy non-shift working males aged 24.7 ± 5.3 years (mean ± SD) underwent four consecutive nights of simulated night-shift work. Between 17:30-04:30 h participants provided saliva s les and completed a 3 min psychomotor vigilance test (PVT-B), 40 min simulated driving task, and 3 min digit symbol substitution test (DSST). Higher sAA levels were associated with faster response speed on the PVT-B, reduced lane variability on the simulated driving task, and improved information processing speed on the DSST during the first night-shift. There were no associations between sAA levels and performance outcomes during subsequent night-shifts. Findings indicate that the usability of sAA to assess the risk of neurobehavioral deficits during shift-work operations is limited. However, the robust circadian rhythm exhibited by sAA during the protocol of circadian misalignment suggests that sAA could serve as a potential circadian marker.
Publisher: Informa UK Limited
Date: 13-10-2016
DOI: 10.1080/07420528.2016.1237520
Abstract: Shiftworkers have impaired performance when driving at night and they also alter their eating patterns during nightshifts. However, it is unknown whether driving at night is influenced by the timing of eating. This study aims to explore the effects of timing of eating on simulated driving performance across four simulated nightshifts. Healthy, non-shiftworking males aged 18-35 years (n = 10) were allocated to either an eating at night (n = 5) or no eating at night (n = 5) condition. During the simulated nightshifts at 1730, 2030 and 0300 h, participants performed a 40-min driving simulation, 3-min Psychomotor Vigilance Task (PVT-B), and recorded their ratings of sleepiness on a subjective scale. Participants had a 6-h sleep opportunity during the day (1000-1600 h). Total 24-h food intake was consistent across groups however, those in the eating at night condition ate a large meal (30% of 24-h intake) during the nightshift at 0130 h. It was found that participants in both conditions experienced increased sleepiness and PVT-B impairments at 0300 h compared to 1730 and 2030 h (p < 0.001). Further, at 0300 h, those in the eating condition displayed a significant decrease in time spent in the safe zone (p < 0.05 percentage of time within 10 km/h of the speed limit and 0.8 m of the centre of the lane) and significant increases in speed variability (p < 0.001), subjective sleepiness (p < 0.01) and number of crashes (p < 0.01) compared to those in the no eating condition. Results suggest that, for optimal performance, shiftworkers should consider restricting food intake during the night.
Publisher: Public Library of Science (PLoS)
Date: 13-02-2013
Publisher: Wiley
Date: 08-2016
DOI: 10.1002/DTA.2033
Abstract: Porous silicon based surface-assisted laser desorption ionization mass spectrometry (pSi SALDI-MS) is an analytical technique well suited for high throughput analysis of low molecular weight compounds from biological s les. A potential application of this technology is the compliance monitoring of opioid addiction programmes, where methadone is used as a pharmacological treatment for drugs such as heroin. Here, we present the detection and quantification of methadone and 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP) from water and clinical s les (saliva, urine, and plasma) from opioid dependent participants using pSi SALDI-MS. A one-step solvent phase extraction using chloroform was developed for the detection of methadone from clinical s les for analysis by pSi SALDI-MS. Liquid chromatography-mass spectrometry (LC-MS) was used as a comparative technique for the quantification of methadone from clinical saliva and plasma s les. In all cases, we obtained a good correlation of pSi SALDI-MS and LC-MS results, suggesting that pSi SALDI-MS may be an alternative procedure for high-throughput screening and quantification for application in opioid compliance testing. Copyright © 2016 John Wiley & Sons, Ltd.
Publisher: Elsevier BV
Date: 11-2015
DOI: 10.1016/J.PBB.2015.09.005
Abstract: There is a complex relationship between drug dependence and stress, with alcohol and other drugs of abuse both relieving stress and potentially inducing physiological stress responses in the user. Opioid drugs have been shown to modulate hypothalamic-pituitary-adrenal (HPA) activity in animal models and in idual response to this modulation may play a role in continuation of drug use. Healthy young Caucasian adults were administered a single dose of immediate release oxycodone (20mg, n=30) or assigned to a control group (n=19) that was not administered the drug. At 0, 1, 2, 4 and 6h post-administration, blood and saliva s les were collected along with assessment of pupil diameter. The HPA response was determined by measurement of salivary cortisol through a commercially available enzyme-linked immunosorbent assay (ELISA). The results were compared to genotype at the -511 and -31 positions in the interleukin1B (IL1B) gene. No difference in cortisol production was initially observed between the two groups, however, when participants were separated based on their genotype for two single nucleotide polymorphisms in the promoter of the IL1B gene, which have been shown to occur at a higher frequency in opioid-dependent populations, in iduals carrying the -511T and -31 C alleles (-511 C/T, -31 C/T or -511 T/T, -31 C/C) had a significantly (p<0.05) higher cortisol levels compared to in iduals homozygous for the -511 C and -31T alleles. These results suggest that in iduals carrying the -511T and -31 C alleles experience HPA activation in response to opioid administration and therefore may be less likely to undertake subsequent self-administration.
Publisher: WMU Department of Occupational Therapy
Date: 04-2016
Publisher: Elsevier BV
Date: 04-2017
DOI: 10.1016/J.PSYNEUEN.2017.01.028
Abstract: During sleep deprivation, neurobehavioral functions requiring sustained levels of attention and alertness are significantly impaired. Discrepancies between subjective measures of sleepiness and objective performance during sustained operations have led to interest in physiological monitoring of operator performance. Alertness, vigilance, and arousal are modulated by the wake-promoting actions of the central noradrenergic system. Salivary alpha-amylase (sAA) has been proposed as a sensitive peripheral measure of noradrenergic activity, but limited research has investigated the relationship between sAA and performance. In a laboratory-controlled environment, we investigated the relationship between sAA levels, subjective sleepiness, and performance during two days (50h) of total sleep deprivation. Beginning at 09:00, twelve healthy participants (5 females) aged 22.5±2.5years (mean±SD) provided saliva s les, recorded ratings of subjective sleepiness, completed a brief 3-min psychomotor vigilance task (PVT-B) and performed a 40-min simulated driving task, at regular 3h intervals during wakefulness. Ratings of subjective sleepiness exhibited a constant linear increase (p<0.001) during sleep deprivation. In contrast, sAA levels showed a marked diurnal profile, with levels increasing during the day (p<0.001) and steadily declining in the evening and early-morning (p<0.001). PVT-B (mean reaction time and mean slowest 10% reaction time) and simulated driving performance (speed deviation and lane deviation) also exhibited diurnal profiles across the two days of sleep deprivation. Performance peaked in the afternoon (p<0.001) and then steadily worsened as wakefulness continued into the evening and early-morning (p<0.001). Further analysis revealed that higher sAA levels in the hour preceding each performance assessment were associated with better PVT-B and driving performance (p<0.001). These findings suggest that sAA measures may be suitable indicators of performance deficits during sustained wakefulness and highlight the potential for sAA to be considered for physiological monitoring of performance. In operational environments sAA levels, as part of a panel of physiological measures, may be useful for assessing fitness-for-duty prior to safety being compromised or when performance deficits are unknown.
Publisher: National Institute of Industrial Health
Date: 2017
Publisher: Elsevier BV
Date: 04-2018
Publisher: Wiley
Date: 27-03-2018
DOI: 10.1111/JSR.12681
Abstract: Caffeine is known for its capacity to mitigate performance decrements. The metabolic side-effects are less well understood. This study examined the impact of cumulative caffeine doses on glucose metabolism, self-reported hunger and mood state during 50 hr of wakefulness. In a double-blind laboratory study, participants were assigned to caffeine (n = 9, 6M, age 21.3 ± 2.1 years body mass index 21.9 ± 1.6 kg/m
Publisher: Springer Science and Business Media LLC
Date: 27-11-2015
Publisher: Oxford University Press (OUP)
Date: 08-2005
DOI: 10.1534/GENETICS.105.043406
Abstract: The flavonoid pigment pathway in plants has been used as a model system for studying gene regulatory mechanisms. C2-Idf is a stable dominant mutation of the chalcone synthase gene, c2, which encodes the first dedicated enzyme in this biosynthetic pathway of maize. Homozygous C2-Idf plants show no pigmentation. This allele also inhibits expression of functional C2 alleles in heterozygotes, producing a less pigmented condition instead of the normal deeply pigmented phenotype. To explore the nature of this effect, the C2-Idf allele was cloned. The gene structure of the C2-Idf haplotype differs substantially from that of the normal c2 gene in that three copies are present. Two of these are located in close proximity to each other in a head-to-head orientation and the third is closely linked. Previous experiments showed that the lower level of pigmentation in heterozygotes is correlated with reduced enzyme activity and low steady-state mRNA levels. We found that c2 transcription occurs in nuclei of C2-Idf/C2 heterozygotes, but mRNA does not accumulate, suggesting that the inhibition is mediated by RNA silencing. Infection of C2-Idf/C2 heterozygotes with viruses that carry suppressors of RNA silencing relieved the phenotypic inhibition, restoring pigment production and mRNA levels. Finally, we detected small interfering RNAs (siRNAs) in plants carrying C2-Idf, but not in plants homozygous for the wild-type C2 allele. Together, our results indicate that the inhibitory effect of C2-Idf occurs through RNA silencing.
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C4CC08762C
Abstract: Desorption ionisation on porous silicon mass spectrometry imaging (DIOS-MSI) was used on fingerprints to map the distribution of exogenous and endogenous molecules present in sweat.
Publisher: Elsevier BV
Date: 11-2015
Publisher: The American Association of Immunologists
Date: 05-2019
DOI: 10.4049/JIMMUNOL.202.SUPP.61.5
Abstract: An automatic pipette is a key piece of laboratory equipment. The ability to accurately and reproducibly deliver any volume is a critical skill to master for all undergraduate students in the laboratory sciences. Over many years we have noted that students struggle in learning several facets of correct pipette usage. These include, choosing the correct pipette for a given volume, correctly setting the pipette and correctly using the plunger to aspirate and dispense the liquid. Students also struggle with unit conversions between ml and μl and vice versa. Lastly, students fail to retain these skills and information in following semesters of teaching. In an attempt to help students with converting between units (μl and ml) as well as choosing the most appropriate pipette for a given volume, I developed an interactive simulation which covered all these major aspects. Using a Gilson pipette as an ex le, the simulation covered how to set the pipette for a number of defined volumes. An Android/iOS app of the simulation has also been developed which can be used during laboratory classes. In 2017, we polled first year undergraduate students about their level of experience, knowledge of pipettes and level of comfort in converting between units and we then explained the simulation to them. The feedback on their skills and the software will be discussed. We also tested the impact of the simulation using 2nd year students enrolled in genetics. Using a laboratory quiz, we found significant improvements in student performance when students used the simulation compared to those that did not. We suggest this interactive approach is a simple and effective way to enhance student learning of key aspects of laboratory pipettes. The simulation is freely available.
Publisher: Elsevier BV
Date: 08-2018
No related grants have been discovered for Chris Della Vedova.