Self-reported 'sleep deficit' is unrelated to daytime sleepiness.

Seemingly, many healthy adults have accrued a sleep debt, as determined by findings based on the multiple sleep latency test (MSLT). However, our recent, extensive survey found self-reported sleep deficit was not linked to daytime sleepiness determined by the Epworth sleepiness scale (ESS). Here, we report on the link between self-reported sleep deficit and gold standard measures of sleepiness: MSLT, Psychomotor vigilance test (PVT) and Karolinska Sleepiness Scale (KSS).

Sleep extension versus nap or coffee, within the context of 'sleep debt'.

Though extended night-time sleep mostly reduces the 'afternoon dip', little is known about evening benefits to alertness, or about comparisons with an afternoon nap or caffeine. Twenty healthy carefully screened adults, normal waking alertness levels, underwent four counterbalanced conditions: usual night sleep; night sleep extended<90 min (usual bed-time); up to 20 min afternoon nap; and 150 mg afternoon caffeine (versus decaffeinated coffee). Sleepiness was measured by afternoon and evening multiple sleep latency test (MSLTs), longer psychomotor vigilance test (PVT) sessions and a subjective sleepiness scale.

The structural impact of a polyglutamine tract is location-dependent.

Polyglutamine (polyQ) expansion leads to protein aggregation and neurodegeneration in Huntington's disease and eight other inherited neurological conditions. Expansion of the polyQ tract beyond a threshold of 37 glutamines leads to the formation of toxic nuclear aggregates. This suggests that polyQ expansion causes a conformational change within the protein, the nature of which is unclear.

High population connectivity across the Indo-Pacific: Congruent lack of phylogeographic structure in three reef fish congeners.

We used the mitochondrial control region and a comparative approach to study the genetic population structure of two surgeonfishes, Naso brevirostris and Naso unicornis, across their Indo-central Pacific ranges. Our purpose was to compare our results with those of a previous study of Naso vlamingii [Klanten, S.O.

2-aminothienopyridazines as novel adenosine A1 receptor allosteric modulators and antagonists.

A pharmacophore-based screen identified 32 compounds including ethyl 5-amino-3-(4- tert-butylphenyl)-4-oxo-3,4-dihydrothieno[3,4- d]pyridazine-1-carboxylate ( 8) as a new allosteric modulator of the adenosine A1 receptor (A1AR). On the basis of this lead, various derivatives were prepared and evaluated for activity at the human A 1AR. A number of the test compounds allosterically stabilized agonist-receptor-G protein ternary complexes in dissociation kinetic assays, but were found to be more potent as antagonists in subsequent functional assays of ERK1/2 phosphorylation.

Structural and biochemical characterization of the oxidoreductase NmDsbA3 from Neisseria meningitidis.

DsbA is an enzyme found in the periplasm of Gram-negative bacteria that catalyzes the formation of disulfide bonds in a diverse array of protein substrates, many of which are involved in bacterial pathogenesis. Although most bacteria possess only a single essential DsbA, Neisseria meningitidis is unusual in that it possesses three DsbAs, although the reason for this additional redundancy is unclear. Two of these N.

A double-blind, prospective, randomized controlled trial comparing highly cross-linked and conventional polyethylene in primary total hip arthroplasty.

Highly cross-linked polyethylene was developed to reduce articular bearing wear in total hip arthroplasty. In vitro studies have shown reduced wear in comparison with conventional polyethylene. A double-blind, prospective, randomized trial was performed comparing highly cross-linked and conventional polyethylene in 119 patients.

Characterization of the drug binding specificity of rat liver fatty acid binding protein.

Liver-fatty acid binding protein (L-FABP) is found in high levels in enterocytes and is involved in the cytosolic solubilization of fatty acids during fat absorption. In the current studies, the interaction of L-FABP with a range of lipophilic drugs has been evaluated to explore the potential for L-FABP to provide an analogous function during the absorption of lipophilic drugs. Binding affinity for L-FABP was assessed by displacement of a fluorescent marker, 1-anilinonaphthalene-8-sulfonic acid (ANS), and the binding site location was determined via nuclear magnetic resonance chemical shift perturbation studies.

Placebo response to caffeine improves reaction time performance in sleepy people.

Caffeine is the most widely used stimulant to counteract sleepiness. However, little is known about any placebo effect of caffeine in sleepy people and the effect of suggestibility. Over a 95 min test period, and in a counterbalanced design, 16 young healthy adults underwent 3 x 30 min sessions at the psychomotor vigilance test (PVT), during an early afternoon 'dip' enhanced by a prior night's sleep restriction (5 h).

Short sleep is a questionable risk factor for obesity and related disorders: statistical versus clinical significance.

Habitually insufficient sleep could contribute towards obesity, metabolic syndrome, etc., via sleepiness-related inactivity and excess energy intake; more controversially, through more direct physiological changes. Epidemiological studies in adult/children point to small clinical risk only in very short (around 5h in adults), or long sleepers, developing over many years, involving hundreds of hours of 'too little' or 'too much' sleep.

Analyzing animal movements using Brownian bridges.

By studying animal movements, researchers can gain insight into many of the ecological characteristics and processes important for understanding population-level dynamics. We developed a Brownian bridge movement model (BBMM) for estimating the expected movement path of an animal, using discrete location data obtained at relatively short time intervals. The BBMM is based on the properties of a conditional random walk between successive pairs of locations, dependent on the time between locations, the distance between locations, and the Brownian motion variance that is related to the animal's mobility.

Do we really want more sleep? A population-based study evaluating the strength of desire for more sleep.

Objective: The sleep literature increasingly points to an apparent chronic sleep debt in the general population. We investigated this by examining perceived shortfalls in daily sleep, using more indirect questioning methods.

Methods: To determine perceived sleep deficits, 10,810 adults completed a simple questionnaire, which avoided leading questions and provided information on sleep length, daytime sleepiness, desired sleep length, a choice of attractive daytime activities in a "free hour", and "stressful lifestyle".

Backbone and side chain 1H, 15N and 13C assignments for the reduced form of the oxidoreductase protein DsbA from Vibrio cholerae.

We have determined 13C/15N/1H assignments for the reduced and oxidised forms of Vibrio cholerae DsbA (VcDsbA). These form the basis for ongoing studies aimed at characterising the dynamics observed in the different redox forms of this bacterial oxidoreductase enzyme.

Probing the flexibility of the DsbA oxidoreductase from Vibrio cholerae--a 15N - 1H heteronuclear NMR relaxation analysis of oxidized and reduced forms of DsbA.

We have determined the structure of the reduced form of the DsbA oxidoreductase from Vibrio cholerae. The reduced structure shows a high level of similarity to the crystal structure of the oxidized form and is typical of this class of enzyme containing a thioredoxin domain with an inserted alpha-helical domain. Proteolytic and thermal stability measurements show that the reduced form of DsbA is considerably more stable than the oxidized form.

Classifying multi-frequency fisheries acoustic data using a robust probabilistic classification technique.

A robust probabilistic classification technique, using expectation maximization of finite mixture models, is used to analyze multi-frequency fisheries acoustic data. The number of clusters is chosen using the Bayesian Information Criterion. Probabilities of membership to clusters are used to classify each sample.

Mobile phone 'talk-mode' signal delays EEG-determined sleep onset.

Mobile phones signals are pulse-modulated microwaves, and EEG studies suggest that the extremely low-frequency (ELF) pulse modulation has sleep effects. However, 'talk', 'listen' and 'standby' modes differ in the ELF (2, 8, and 217Hz) spectral components and specific absorption rates, but no sleep study has differentiated these modes. We used a GSM900 mobile phone controlled by a base-station simulator and a test SIM card to simulate these three specific modes, transmitted at 12.

Examination of the role of intestinal fatty acid-binding protein in drug absorption using a parallel artificial membrane permeability assay.

Transcellular diffusion across the absorptive epithelial cells (enterocytes) of the small intestine is the main route of absorption for most orally administered drugs. The process by which lipophilic compounds transverse the aqueous environment of the cytoplasm, however, remains poorly defined. In the present study, we have identified a structurally diverse group of lipophilic drugs that display low micromolar binding affinities for a cytosolic lipid-binding protein - intestinal fatty acid-binding protein (I-FABP).

Morphological and functional effects of altered cysteine string protein at the Drosophila larval neuromuscular junction.

The synaptic vesicle-associated cysteine string protein (CSP) is critical for neurotransmitter release at the neuromuscular junction (NMJ) of Drosophila, where the approximately 4% of mutant flies lacking CSP that survive to adulthood exhibit spastic jumping and shaking, temperature-sensitive paralysis, and premature death. Previously, it has been shown that CSP is also required for nerve terminal growth and the prevention of neurodegeneration in Drosophila and mice. At larval csp null mutant NMJs of Drosophila, intracellular recordings from the muscle showed that evoked release is significantly reduced at room temperature.

Trends in mortality from ischemic heart disease in Canada, 1986-2000.

This study examined trends in ischemic heart disease (IHD) mortality rates in Canada from 1986 to 2000, including analyses at the county level. The study population comprised Canadians aged 35 and over. Age-standardized mortality rates (ASMRs) were computed.

A high sugar content, low caffeine drink does not alleviate sleepiness but may worsen it.

Although the ingestion of high levels of glucose might have a short acting alerting effect, there is evidence of an ensuing enhancement of sleepiness in people already sleepy. Some 'energy drinks' contain large quantity of sugars. We compared 250 ml of a well known 'energy drink' (42 g sugars, containing a low [30 mg] level of caffeine for 'flavouring') with a nil sugar nil caffeine, similar tasting control.

Selecting the best home range model: an information-theoretic approach.

Choosing an appropriate home range model is important for describing space use by animals and understanding the ecological processes affecting animal movement. Traditional approaches for choosing among home range models have not resulted in general, consistent, and unambiguous criteria that can be applied to individual data sets. We present a new application of information-theoretic model selection that overcomes many of the limitations of traditional approaches, as follows.

Sleepiness enhances distraction during a monotonous task.

Study Objectives: Although sleepiness appears to heighten distraction from the task at hand, especially if the latter is dull and monotonous, this aspect of sleep loss has not been assessed in any systematic way. Distractions are a potential cause of performance lapses (as are micro-sleeps). Here, we investigate the effects of sleepiness on a monotonous task, with and without distraction.

Reliability of speech-language pathologist and otolaryngologist ratings of laryngeal signs of reflux in an asymptomatic population using the reflux finding score.

Objective: To determine inter- and intrajudge agreement in rating signs of laryngopharyngeal reflux (LPR) under "ideal" conditions: Experienced coworkers in a practice devoted to voice-disordered patients, raters trained in the items on a standardized scale, raters from both speech-language pathology (SLP) and otolaryngology, and raters of asymptomatic participants.

Study Design: Prospective study using a scale to rate videolaryngoscopic examinations.

Methods: Two SLPs and two otolaryngologists used the Reflux Finding Scale (RFS) to independently rate videotapes of endoscopic examinations for 30 participants asymptomatic of reflux.