Background: Previous research has suggested that enteroviruses may be implicated in the development and persistence of Chronic Fatigue Syndrome (CFS). One method of investigating this topic has been to use a polio vaccination challenge,... more
Background: Previous research has suggested that enteroviruses may be implicated in the development and persistence of Chronic Fatigue Syndrome (CFS). One method of investigating this topic has been to use a polio vaccination challenge, and a previous study showed that CFS patients had more shedding than healthy controls. There was no effect of the vaccination on the clinical condition or wellbeing of the CFS patients. Methods: In the previous study, the control group were more likely to have had a recent booster vaccination. This was controlled in the present study, where 18 CFS patients were randomly assigned to vaccination or placebo conditions. Nine healthy volunteers were also given the polio vaccination. Results: The results confirmed that vaccination had no negative effects on the CFS group. Although there was more virus shedding in the CFS polio group than in the control polio group, this difference was not significant. Conclusion: This study confirms that polio vaccination ...
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ABSTRACT Background: Previous research has suggested that chronic fatigue syndrome (CFS) patients report more upper respiratory tract illnesses (URTIs) than controls. Aims: The present study aimed to replicate and extend this research.... more
ABSTRACT Background: Previous research has suggested that chronic fatigue syndrome (CFS) patients report more upper respiratory tract illnesses (URTIs) than controls. Aims: The present study aimed to replicate and extend this research. Method: A prospective study of the incidence of URTIs was conducted. This was similar to previous work involving diary studies but also included objective measures of illness severity (e.g. nasal secretion; sub-lingual temperature) and infection (virus isolation from nasal swabs and antibody changes). Fifty-seven patients with CFS, diagnosed according to the 1994 CDC criteria, were recruited randomly from a volunteer panel compiled of patients who had attended the Cardiff CFS outpatient clinic. A further 57 individuals without CFS were recruited from a general population research panel. Results: The results confirmed that CFS patients report more upper respiratory virus infections and the virological results showed that this was not due to a reporting bias but reflected greater susceptibility to infection. Conclusions: This increased susceptibility to infection in the CFS group can account for the increased reporting of URTIs found in this and previous studies.
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A new partial studio model for teaching undergraduate heat and mass transfer is described. Students are exposed to modern numerical algorithms and visualization techniques while learning the fundamental principles of heat transfer in an... more
A new partial studio model for teaching undergraduate heat and mass transfer is described. Students are exposed to modern numerical algorithms and visualization techniques while learning the fundamental principles of heat transfer in an interactive PC-based classroom setting. As part of this project seven software modules were developed for numerical simulations of fundamental heat transfer and fluids processes. The modules
Research Interests: Aerospace Engineering, Computer Science, Visualization, Engineering Education, Mass Transfer, and 14 moreHeat Transfer, User Interface, Numerical Analysis, Fluid Dynamics, Heat and Mass Transfer, Teaching, Visual basic, Numerical Simulation, Fortran, Graphics, Microsoft Visual Studio, HEAT ENGINES, Visualization Technique, and Visualization techniques
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This study examined the effects of breakfast cereal and caffeinated coffee on working memory, attention, mood, and cardiovascular function. One hundred and forty-four volunteers (72 male, 72 female, mean age 21 years) were assigned to one... more
This study examined the effects of breakfast cereal and caffeinated coffee on working memory, attention, mood, and cardiovascular function. One hundred and forty-four volunteers (72 male, 72 female, mean age 21 years) were assigned to one of the groups formed by combining breakfast (cereal versus no breakfast) and caffeine (caffeinated versus decaffeinated coffee) conditions. The volunteers completed a baseline session
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Research Interests: Attention, Medicine, Multidisciplinary, Nature, Humans, and 4 moreNorepinephrine, Adult, Imidazoles, and Clonidine
The present study examined whether volunteers with common colds showed impairments in objective and subjective indicators of alertness. All the volunteers (N = 81) were tested when healthy to provide baseline data for mood, simple and... more
The present study examined whether volunteers with common colds showed impairments in objective and subjective indicators of alertness. All the volunteers (N = 81) were tested when healthy to provide baseline data for mood, simple and choice reaction time tasks, and an anti-saccadic eye movement task. When subjects developed a cold (N = 17) they returned to the laboratory and repeated the procedure. Volunteers (N = 64) who remained healthy over a 10-week period were recalled as controls. The results showed that those with colds felt significantly less alert and had significantly slower simple and choice reaction times and eye movements. This extends earlier research and shows that electrophysiological measures may also be of use in assessing the behavioral changes induced by upper respiratory tract illnesses.
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An experiment was carried out to determine whether caffeinated and decaffeinated coffee removed the malaise (reduced alertness, slower psychomotor performance) associated with having a common cold. One hundred volunteers were tested when... more
An experiment was carried out to determine whether caffeinated and decaffeinated coffee removed the malaise (reduced alertness, slower psychomotor performance) associated with having a common cold. One hundred volunteers were tested when healthy and 46 returned to the laboratory when they developed colds. Those subjects who remained healthy were then recalled as a control group. On the second visit subjects carried out two sessions, one pre-drink and another an hour after the drink. Subjects were randomly assigned to one of the following three conditions, caffeinated coffee (1.5 mg/kg caffeine/body weight), decaffeinated coffee or fruit juice. Subjects with colds reported decreased alertness and were slower at performing psychomotor tasks. Caffeine increased the alertness and performance of the colds subjects to the same level as the healthy group and decaffeinated coffee also led to an improvement. These results suggest that drugs which increase alertness can remove the malaise ass...
Research Interests: Psychopharmacology, Adolescent, Medicine, Humans, Caffeine, and 15 moreFemale, Male, Common Cold, Adult, Body Weight, Gv, Alertness, Fruit Juice, Control Group, Malaise, Psychomotor Performance, Psychology and Cognitive Sciences, Psychomotor Learning, Central nervous system stimulants, and Medical and Health Sciences
There have been numerous studies on the effects of caffeine on behaviour and cardiovascular function. It is now important to clarify the mechanisms that underlie such effects, and the main objective of the present study was to investigate... more
There have been numerous studies on the effects of caffeine on behaviour and cardiovascular function. It is now important to clarify the mechanisms that underlie such effects, and the main objective of the present study was to investigate whether changes in central noradrenaline underlie some of the behavioural and cardiovascular effects of caffeine. This was examined using a clonidine challenge paradigm. Twenty-four healthy volunteers were assigned to one of four conditions: (i) clonidine/caffeine; (ii) clonidine/placebo; (iii) placebo/caffeine; (iv) placebo/placebo. Baseline measurements of mood, cognitive performance, saccadic eye movements and cardiovascular function were recorded. Subsequently, volunteers were given either clonidine (200 μg) or placebo and consumed coffee containing caffeine (1.5 mg/kg) or placebo. The test battery was then repeated 30 min, 150 min and 270 min later. A second cup of coffee (with the same amount of caffeine as the first) was consumed 120 min aft...
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An experiment was carried out to determine whether idazoxan, a drug which increases the turnover of central noradrenaline, removes the malaise (reduced alertness, slower psychomotor performance) associated with upper respiratory tract... more
An experiment was carried out to determine whether idazoxan, a drug which increases the turnover of central noradrenaline, removes the malaise (reduced alertness, slower psychomotor performance) associated with upper respiratory tract illness (URTI). Eighty-one volunteers were tested when healthy and 17 returned to the laboratory when they developed URTIs. Those who remained healthy were then recalled as a control group. Volunteers were tested before and after receiving either idazoxan (40 mg) or a lactose placebo. Idazoxan removed the URTI-induced slowing in a simple reaction time task and this group performed at a comparable level to the healthy group. No significant stimulant effect of idazoxan was found in the healthy subjects. The results suggest that at least part of the malaise induced by URTIs may reflect reductions in central noradrenaline and that this can be reversed by compounds such as idazoxan.
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Measurement of the thermal boundary conductance (TBC) by use of a nondestructive optical technique, transient thermoreflectance (TTR), is presented. A simple thermal model for the TTR is presented with a discussion of its applicability... more
Measurement of the thermal boundary conductance (TBC) by use of a nondestructive optical technique, transient thermoreflectance (TTR), is presented. A simple thermal model for the TTR is presented with a discussion of its applicability and sensitivity. A specially prepared sample series of Cr, Al, Au, and Pt on four different substrates (Si, sapphire, GaN, and AlN) were tested at room temperature and the TTR signal fitted to the thermal model. The resulting TBC values vary by more than a factor of 3 0.71×108-2.3×108 W/m2 K. It is shown that the diffuse mismatch model (DMM) tended to overpredict the TBC of interfaces with materials having similar phonon spectra, while underpredicting the TBC for interfaces with dissimilar phonon spectra. The DMM only accounts for diffuse elastic scattering. Other scattering mechanisms are discussed which may explain the failure of the DMM at room temperature.
Research Interests: Mechanical Engineering, Chemical Engineering, Materials Science, Heat Transfer, DIELECTRIC, and 15 moreTemperature, Interfaces, Conductance, Sapphire, Interface, Thermal Conductivity, Phonons, Elastic Scattering, Phonon, Thermal Boundary Resistance, Scattering, Reflectance, Interdisciplinary Engineering, Phonon Scattering, and Dielectric Materials
Research Interests: Psychology, Cognitive Science, Personality, Performance, Stress, and 9 moreHuman, Mood, Alcohol, RA, Bf, Rc, R, QP, and Pharmacology and pharmaceutical sciences
An experiment was carried out to examine the effects of 40 mg of caffeine given in different drinks (coffee, water, tea, cola) on mood and performance. One hundred and forty-four volunteers were randomly assigned to one of the groups... more
An experiment was carried out to examine the effects of 40 mg of caffeine given in different drinks (coffee, water, tea, cola) on mood and performance. One hundred and forty-four volunteers were randomly assigned to one of the groups formed by combining the caffeine/placebo and ...
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The present study examined the relationships between subjective reports of sleep and mental functioning. This was done both for healthy subjects and chronic fatigue syndrome patients, a group who frequently report sleep disorders. Sleep... more
The present study examined the relationships between subjective reports of sleep and mental functioning. This was done both for healthy subjects and chronic fatigue syndrome patients, a group who frequently report sleep disorders. Sleep abnormalities were found to be ...
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An experiment was conducted to examine the effects of caffeine and noise on mood, mental performance and cardiovascular function. One hundred and six young adults (mean age 21·2 years) took part in the study. Subjects were assigned to one... more
An experiment was conducted to examine the effects of caffeine and noise on mood, mental performance and cardiovascular function. One hundred and six young adults (mean age 21·2 years) took part in the study. Subjects were assigned to one of six groups formed by ...
Research Interests: Psychology, Cognitive Science, Audiology, Human, Mood, and 7 moreCaffeine, QM, Bf, Rc, R, QP, and Pharmacology and pharmaceutical sciences
A double-blind placebo controlled trial was carried out to examine the effects of supplementation with anti-oxidant vitamins on mental performance in the elderly. The participants were assigned to either placebo or vitamin groups and... more
A double-blind placebo controlled trial was carried out to examine the effects of supplementation with anti-oxidant vitamins on mental performance in the elderly. The participants were assigned to either placebo or vitamin groups and assessed at 4, 8 and 12 months. Blood samples ...
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The aim of the present study was to assess the impact of upper respiratory tract illnesses on efficiency at work. This was done using the 'after-effect' technique with... more
The aim of the present study was to assess the impact of upper respiratory tract illnesses on efficiency at work. This was done using the 'after-effect' technique with measurements being taken before and after work and the difference between these giving an indication of efficiency over the day. All of the volunteers (N = 48) were tested when healthy to provide baseline data for simple reaction time and mood. When volunteers developed an upper respiratory tract illness (URTI) they (N = 16) repeated the procedure. Those who remained healthy over a three month period (N = 32) were recalled as healthy controls. In addition to the performance test and mood ratings the volunteers kept a sleep log and also rated how demanding the day had been and how much effort they had put in. The results showed that those with URTIs had slower reaction times and a more negative mood both before and after work. Illness did not have an effect on ratings of demand and effort. Those who were ill reported greater sleep disturbance but this could not account for the impaired performance or negative mood states. These results suggest that upper respiratory illnesses may impair performance and well-being at work.
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Objectives. First, to determine whether chronic fatigue syndrome (CFS) patients report increased susceptibility to upper respiratory tract illnesses (URTIs) compared with healthy volunteers. Second, to determine whether symptom severity... more
Objectives. First, to determine whether chronic fatigue syndrome (CFS) patients report increased susceptibility to upper respiratory tract illnesses (URTIs) compared with healthy volunteers. Second, to determine whether symptom severity and use of medication is ...