Continuous positive airway pressure requirement during the first month of treatment in patients with severe obstructive sleep apnea

OBJECTIVES: (1) To compare the continuous positive airway pressure (CPAP) requirement at the time of diagnosis (T0), after 2 weeks (T2), and after 4 weeks (T4) of CPAP treatment, in patients with severe obstructive sleep apnea (OSA); and (2) to assess whether any alteration in CPAP requirement over the first 4 weeks of CPAP treatment would influence daytime alertness, subjective sleepiness, or mood. DESIGN: A prospective, controlled, single-blind crossover study. SETTING: University teaching hospital. PATIENTS: Ten patients with newly diagnosed and previously untreated severe OSA (aged 52+/-9 years, apnea hypopnea index [AHI] of 99+/-31) and subsequently 10 control patients (aged 52+/-11 years, AHI 85+/-17). MEASUREMENTS: Overnight polysomnography with CPAP titration to determine the CPAP requirement, which was standardized for body position and sleep stage, on all three occasions (T0, T2, T4). Objective sleep quality, daytime alertness, subjective sleepiness (Epworth Sleepiness Scale), and mood (Hospital Anxiety and Depression Scale). RESULTS: CPAP requirement decreased from T0 to T2 (median difference, 1.5 cm H2O, 95% confidence interval [CI], 1.1 to 2.7 cm H2O, p=0.0004) and did not differ between T2 and T4. Use of the lower CPAP pressure during T2 to T4 was associated with a decrease in Epworth scale (mean difference, 2.6, 95% CI, 1.2 to 4; p=0.01) and anxiety (median change, 2; 95% CI, 0.5 to 2.9, p=0.03) scores, as compared with the first 2 weeks. Daytime alertness did not differ between T0 to T2 and T2 to T4. CONCLUSION: CPAP requirement falls within 2 weeks of starting CPAP treatment. A change to the lower required CPAP was not associated with any deterioration in daytime alertness but was associated with small subjective improvements in sleepiness and mood.     

Reliability of potential clinical measures of muscle tone in the elbows of patients after stroke

In order to establish a genotype-phenotype relationship, we have identified both mutant phenylalanine hydroxylase (PAH) genes in 108 phenylketonuria (PKU) patients (27 different alleles, 54 different genotypes). One major group of patients with very high pretreatment phenylalanine values ("classical" PKU) exclusively comprised homozygotes of the PKU mutations I65T, G272X, F299C, Y356X, R408W, IVS12nt1, and compound heterozygotes of various combinations of these alleles with G46S, R261Q, R252W, A259T, R158Q, D143G, R243X, E280K, or Y204C. A second major group of patients with lower phenylalanine values ("mild" PKU) comprised mutations A300S, R408Q, Y414C in various compound heterozygous states, and R261Q, R408Q, Y414C in homozygotes. The phenylalanine values in these groups were non-overlapping. In addition, a smaller group of patients formed the transition between the two main groups. In sib pairs 4 of 15 had discordant pretreatment phenylalanine values. Conclusion: Our results are consistent with the view that allelic heterogeneity at the PAH locus dominates the biochemical phenotype in PKU and that genotype information is able to predict the metabolic phenotype in PKU patients.     

Acutely shifting the sleep-wake cycle: nighttime sleepiness after diurnal administration of temazepam or placebo

HYPOTHESIS: Sleepiness on the job is a common problem suffered by people involved in night shift work, especially in conditions of abrupt reversal of the sleep-wake cycle, such as emergencies and combat air operations. It is well known that sleepiness can severely affect alertness and performance. One of the most useful countermeasures is to take a prophylactic nap before working at irregular hours. To induce and maintain sleep in the "forbidden zones for sleep" during the day, it is possible to use suitable benzodiazepine hypnotics such as temazepam (TMZ). However, it is then necessary to monitor sleepiness and performance the night following the diurnal intake of the drug in order to evaluate possible side effects. METHODS: In this study, sleepiness was subjectively and objectively measured during the night after a daytime administration of TMZ 20 mg in soft gelatine capsules or placebo to obtain a prophylactic sleep. RESULTS AND DISCUSSION: Results showed the effectiveness of TMZ for inducing and maintaining diurnal sleep. This lengthening of total sleep time did not cause a decrease of sleepiness during the night, but no significant carry over effect of TMZ was present for nighttime sleep tendency. Both polygraphic and subjective measures of sleep latency decreased during the night. Finally, no significant relationship between the Stanford Sleepiness Scale and the Multiple Sleep Latency Test measures was found.     

The role of melatonin and circadian phase in age-related sleep-maintenance insomnia: assessment in a clinical trial of melatonin replacement

The present investigation used a placebo-controlled, double-blind, crossover design to assess the sleep-promoting effect of three melatonin replacement delivery strategies in a group of patients with age-related sleep-maintenance insomnia. Subjects alternated between treatment and "washout" conditions in 2-week trials. The specific treatment strategies for a high physiological dose (0.5 mg) of melatonin were: (1) EARLY: An immediate-release dose taken 30 minutes before bedtime; (2) CONTINUOUS: A controlled-release dose taken 30 minutes before bedtime; (3) LATE: An immediate-release dose taken 4 hours after bedtime. The EARLY and LATE treatments yielded significant and unambiguous reductions in core body temperature. All three melatonin treatments shortened latencies to persistent sleep, demonstrating that high physiological doses of melatonin can promote sleep in this population. Despite this effect on sleep latency, however, melatonin was not effective in sustaining sleep. No treatment improved total sleep time, sleep efficiency, or wake after sleep onset. Likewise, melatonin did not improve subjective self-reports of nighttime sleep and daytime alertness. Correlational analyses comparing sleep in the placebo condition with melatonin production revealed that melatonin levels were not correlated with sleep. Furthermore, low melatonin producers were not preferentially responsive to melatonin replacement. Total sleep time and sleep efficiency were correlated with the timing of the endogenous melatonin rhythm, and particularly with the phase-relationship between habitual bedtime and the phase of the circadian timing system.     

Objective assessment of sleep and alertness in medical house staff and the impact of protected time for sleep

We studied 26 physicians in postgraduate medical training ("house staff") to objectively quantify their sleep, alertness, and psychomotor performance while working on call. This study provided precise data on the extent of sleep deprivation during a typical call night, the workload factors predictive of sleep loss, and the extent to which protected time for sleep within the call night can ameliorate sleep loss and consequent daytime sleepiness. We used ambulatory EEG recording equipment and a standardized computer-based performance test to monitor sleep and alertness over the course of a 36-hour call day. Comparisons were made between interns provided with 4 hours of protected time for sleep by a covering resident ("night-float") and interns without such coverage. As anticipated, we found evidence that hospital interns were severely sleep-deprived, to an extent even greater than prior behavioral observations have suggested. Interns in both conditions spent an average of less than 5 hours (295.4 minutes) in bed attempting to sleep and obtained an average of 3.67 hours (220.1 minutes) of sleep (range 37.4-358.4 minutes). Provision of the night-float for 4 hours did not significantly change total sleep time (TST) (212.8 minutes covered vs. 224.9 minutes uncovered), but sleep efficiency was significantly improved (86.5% vs. 70.3%; p = 0.001). Covered interns also obtained significantly more slow-wave sleep than the uncovered interns (65.4 minutes vs. 51.1 minutes; p = 0.05). However, measures of alertness and performance were not significantly different between the two groups and were only weakly related to TST. These data suggest that significant chronic sleep deprivation is relatively unaffected by sleep obtained in the hospital and that provision of protected time for sleep does not significantly improve TST.     

The therapeutic focus in significant sessions of master therapists: a comparison of cognitive-behavioral and psychodynamic-interpersonal interventions

This study was designed to test the hypothesis that bright light (BL) can have a stimulating effect on vigilance even in the absence of suppression of melatonin secretion and that this effect can be detected when measured in subjects with low vigilance levels. Seven normal subjects were exposed to bright-white light (BL group) and seven to dim-red light (DL group) on 2 consecutive days, each following a night of 4-h sleep restriction. The light treatment was administered in the late morning, between 0900 and 1330 hours. Salivary melatonin measurements indicated that BL did not suppress melatonin secretion or induce circadian phase shifts. The effects of the two treatments were compared on validated measures of daytime vigilance: immediate effects were evaluated on subjective alertness during the light treatment, whereas short-term (0.5-10.5 h) and long-term (20.5-34.5 h) carryover effects were measured on subjective alertness, daytime sleep latencies (DSL), and psychomotor performance. After two nights of sleep restriction, subjective alertness and daytime sleep latencies decreased significantly, but there was no effect of the light treatment. BL treatment did not affect global performance, but there was an effect on the strategy used by the subjects, as shown by faster reaction times and increased percentage of errors in the BL group. It was concluded that daytime BL exposure did not have a stimulating effect on our measures of vigilance even in sleep-deprived subjects but that it may increase physiological arousal and affect the subjects' behavior in some specific performance tasks.     

Temporal correlation between neuronal tail ganglion activity and locomotion in the leech, Hirudo medicinalis

A field study of work and sleep patterns among commercial merchant marine personnel is reported. Data collected over a 10-30-d period from 141 subjects aboard eight ships included information concerning work-rest schedules, sleep timing, alertness on the job and critical fatigue. The data indicate that watchstanders on the 4-on, 8-off schedule show considerable disruption in their sleep. The average sleep duration for all mariners is 6.6 h; watchstanders obtain their sleep in fragmented periods that are frequently less than 5 h in duration. Analysis of critical fatigue shows an incidence of 1-24% across personnel and measures. Of particular concern are the watchstanders on the 04.00-08.00 schedule, who sleep less than 4 h per 24-h period 22% of the time. Potential countermeasures, including changes in scheduling and staffing are proposed.     

Effect of modafinil on heat production and regulation of body temperatures in cold-exposed humans

Military personnel often undergo sustained operations that affect vigilance and alertness. Pharmacological agents may be used to enhance vigilance. Most such agents also have thermogenic properties. Whether a new promising stimulant, modafinil (Lyons and French, Aviat. Space Environ. Med. 1991; 62:432-435), has a beneficial effect on cold tolerance in the military context, is not known. The goal of this study was, therefore, to evaluate the effect of this new drug on thermal balance and the regulation of body temperatures in neutral conditions and when challenged by a cold exposure. Nine subjects underwent three trials each: two in the cold (3 h at rest, 10 degrees C) 0.5 h after the ingestion of either placebo or modafinil (200 mg), and one in thermal neutrality with modafinil (same conditions except Tdb = 29.3 degrees C). As expected, cold produced a drop in Tre and Tsk and an increase in Vo2. Although non-significant, there was a tendency for a slightly greater drop in Tre with modafinil (0.65 degrees C vs. 0.57 degrees C with placebo). A similar tendency was found for the heat debt (S) which was greater with modafinil than with placebo (16.1 +/- 0.7 vs. 14.7 +/- 0.6 kJ.kg-1, respectively, +9.5%, p = 0.11). This tendency appears to be the combined result of a slightly lower mean heat production during the test and a slightly greater mean dry heat loss. When tested at thermal neutrality, the drug had no effect on any thermal or metabolic parameters. The results demonstrate that the ingestion of a single dose of modafinil has no significant acute effect on thermal balance in neutral conditions and on thermoregulation in normal subjects exposed to cold. However, a tendency for slightly greater cooling was noted with modafinil. It is not known whether the use of modafinil in conjunction with sleep deprivation (a likely scenario) could magnify this effect.     

Age, smoking, and negative affectivity as predictors of sleep patterns among shiftworkers in two environments.

Although adaptation to shiftwork has been widely studied, little is known about how individual and environmental factors combine to influence sleep among shiftworkers. This study examined age, smoking, and negative affectivity (NA) as predictors of sleep duration and quality for 3 work phases (day shifts, DS; night shifts, NS; and leave periods, LP). Data were collected from personnel working 12-hr shifts, onshore (n = 330) or offshore (n = 456). Individual factors predicted patterns of sleep measures across the DS, NS, and LP phases onshore, but not offshore; onshore, work phase interacted with smoking and with age to predict sleep duration and with NA to predict sleep quality. The role of the offshore environment in shiftwork adaptation is discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sources of reports of visual and auditory sensations in perceptual-isolation experiments.

The review analyzes the experiments on perceptual isolation with special reference to the phenomena of reported visual and auditory sensations. Variables analyzed include: methods of confinement and restriction, conditions of illumination, duration of isolation, set, instructions and suggestions, reporting or verbalization instructions, sleep, S populations, prior knowledge and expectations, intelligence and personality characteristics of Ss, stress response, and methods of obtaining reported visual and auditory sensations. The relevance of some of the findings to physiological, psychoanalytic, cognitive, and social psychological theories of perceptual isolation are discussed. Variables which seem important in the phenomena discussed are set, verbalization instructions, S's alertness, and E's methods of obtaining responses. (2 p. ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sleep problems of junior high school students in Taipei

The objective of this work was to study the relationship between daily sleep time and characteristics of students, e.g. grade level, gender, and academic program. A sleep habit questionnaire was designed to survey students at two junior high schools, one from northern Taipei and the other from southern Taipei. The impact of shortened duration of sleep on daily function was also evaluated. A total of 965 students and their parents were selected randomly in December 1993 for the questionnaire study. The response rate was 96.4% (930) for students and 88.6% (855) for parents. The self-reported daily sleep time of students declined, and daytime sleepiness and moodiness increased in the higher grades. The girls slept fewer hours than the boys and did not show an increase in daytime sleepiness. Those students not taking the senior high school joint entrance examination slept more hours at night and maintained more alertness in the daytime than those who were taking the examination. The more academic pressures that adolescents faced, the fewer hours they slept. Students not participating in the joint entrance examination seemed to show a healthier sleep pattern. Little sleep at night made the students feel sleepy in the daytime and tired, drowsy, moody and difficult at arising in the morning. The reason why girls slept less than boys needs further investigation.     

Sleep patterns of children sleeping in residential care, in kibbutz dormitories and at home--a comparative study

The present study compares sleep patterns of two groups of children sleeping away from their families, in residential care (n = 31, age 3.7 +/- 1.7 years) and kibbutz (n = 29, age 3.7 +/- 1.8 years) dormitories, with age-matched children sleeping at home (n = 21, age 3.7 +/- 1.8 years). Sleep was monitored by wrist-worn actigraphs for three consecutive nights and assessed by sleep questionnaires, which were completed by parents of the kibbutz children and caretakers at residential care. Children in the residential care settled to sleep significantly earlier and slept longer than those children living in a kibbutz or at home. The longest period of uninterrupted sleep was more extended for children sleeping at home, compared to those sleeping in communal dormitories. Correlation analysis between various assessments of sleep and waking behaviors revealed a different pattern for kibbutz and residential care children. For the kibbutz children, there were significant correlations between difficulties falling asleep and various attributes of daytime tiredness. Conversely, in the residential care, difficulties falling asleep were significantly and positively correlated with parameters associated with daytime alertness. This pattern of correlations and the actigraphic data indicate that difficulties in falling asleep for children in residential care are probably a consequence of being put to bed too early and according to a rigid schedule, and not the result of emotional factors.     

Correction of acidosis in dialysis patients increases branched-chain and total essential amino acid levels in muscle

The following four issues were assessed in a group of 110 adults between the age of 20 and 59y: (1) the effect of age (regarded as a continuous variable) on polysomnographic sleep characteristics, habitual sleep-diary patterns, and subjective sleep quality; (2) the effects of age on morningness-eveningness; (3) the effects of morningness-eveningness on sleep, after controlling for the effects of age; and (4) the role of morningness-eveningness as a mediator of the age and sleep relationship. Increasing age was related to earlier habitual waketime, earlier bedtime, less time in bed and better mood and alertness at waketime. In the laboratory, increasing age was associated with less time asleep, increased number of awakenings, decreased sleep efficiency, lower percentages of slow-wave sleep (SWS) and rapid eye movement (REM) sleep, higher percentages of Stage 1 and 2, shorter REM latency and reduced REM activity and density. Increasing age was also associated with higher morningness scores. After controlling for the effects of age, morningness was associated with earlier waketime, earlier bedtime, less time in bed, better alertness at waketime, less time spent asleep, more wake in the last 2 h of sleep, decreased REM activity, less stage REM (min and percentage), more Stage 1 (min and percentage) and fewer minutes of Stage 2. For one set of variables (night time in bed, waketime, total sleep time, wake in the last 2 h of sleep and minutes of REM and REM activity), morningness-eveningness accounted for about half of the relationship between age and sleep. For another set of variables (bedtime, alertness at waketime, percentages of REM and Stage 1), morningness-eveningness accounted for the entire relationship between age and sleep. In conclusion, age and morningness were both important predictors of the habitual sleep patterns and polysomnographic sleep characteristics of people in the middle years of life (20-59 y).     

Panic and panic disorder in the United States

OBJECTIVES: Shift work and rapid travel across several time zones leads to desynchronization of internal circadian rhythms from the external environment and from each other with consequent problems of behaviour, physiology and performance. Field studies of travellers and shift workers are expensive and difficult to control. This investigation concerns the simulation of such rhythm disturbance in a laboratory environment. The main objectives are to assess the ability of controlled exposure to moderately bright light and darkness/sleep to delay circadian rhythms in volunteers without environmental isolation and, secondly, to evaluate the use of different indices of melatonin (MT) secretion together with self-rated alertness as marker rhythms. PATIENTS: Six normal volunteers aged 22-26 years (mean +/- SD 24.3 +/- 1.4). DESIGN: Subjects were exposed to the following periods of moderately bright light (1200 lux) on three consecutive days in early December 1991: Day (D)1: 2000-0200 h, D2: 2200-0400 h and D3: 2400-0600 h. Each period was followed by 8 hours of darkness (< 1 lux). Hourly blood, sequential 4-hourly urine (8-hourly when asleep) and hourly saliva (except when asleep) samples were taken throughout a 24-hour period on D0 (baseline), D4 (1 day post-light treatment) and D7 (4 days post-light treatment). During waking hours, subjective alertness was rated every 2 hours on a visual analogue scale. MEASUREMENTS: MT was measured in plasma and saliva, and its metabolite, 6-sulphatoxymelatonin (aMT6s), was measured in urine. MT, aMT6s and alertness scores were analysed by ANOVA and a cosinor analysis program. RESULTS: A delay shift was present in the aMT6s, plasma MT and salivary MT rhythms (degree of shift: 2.67 +/- 0.3 h (P < 0.001, n = 5); 2.35 +/- 0.29 h (P < 0.001, n = 6); and 1.97 +/- 0.32 h (P < 0.01, n = 6), mean +/- SEM, respectively) 1 day post-light treatment compared to baseline. Adaptation to the initial phase position was apparent by the 4th post-treatment day. Significant correlations were obtained between plasma MT onset (degree of shift: 3.12 +/- 0.74 h (P < 0.001, n = 6, mean +/- SEM)) and the acrophases (calculated peak times) of plasma MT (P < 0.001), salivary MT (P < 0.05) and urinary aMT6s (P < 0.01). A significant phase delay in the alertness rhythm was also evident 1 day post-treatment (3.08 +/- 0.67 h (P < 0.01, n = 6, mean +/- SEM)) with adaptation by the 2nd post-treatment day. CONCLUSIONS: This study suggests that these methods of determining MT secretion are comparable and give reliable assessments of the MT circadian phase position even after a phase-shift. Significant phase-shifts of similar magnitude can be induced in both MT and alertness rhythms using moderate intensity bright light at night.     

Neuropsychological functioning and determinants of morning alertness in patients with obstructive sleep apnea syndrome

Neuropsychological functioning is reported to be impaired in patients suffering from obstructive sleep apnea syndrome (OSAS). This syndrome is characterized by nocturnal respiratory disturbances, blood oxygen desaturations, sleep fragmentation, and excessive daytime sleepiness. Opinions are divided concerning the exact relationship between the observed cognitive deficits, nocturnal hypoxia, sleep disruption, and impaired daytime alertness. In the present study, morning neuropsychological function of 26 moderate to severe middle-aged sleep apneics is compared to that of 22 primary insomniacs. There were no performance differences on a range of neuropsychological tests among the two patient groups. In addition, the data suggest that morning alertness impairment, which is closely associated with a lack of slow wave sleep (SWS) and rapid eye movement (REM) sleep, is of major importance in inducing poorer cognitive performance in patients with moderate to severe sleep apnea.     

基于PnET-CN模型的亚热带人工针叶林生产力与固碳潜力模拟研究

A generalized, lumped-parameter ecological model PnET-CN was calibrated and validated for a subtropical coniferous plantation in southem China. PnET-CN model describes the biogeochemical cycles of carbon(C)and nitrogen(N)and can assist in estimating carbon sequestration potential. For validation of PnET-CN, data from coniferous forest plantations in southern China was used. Simulated daily gross primary productivity(GPP)from 2005 to 2007 agreed well with observations(R2=0.56, S.D.=0.009). Simulations of monthly soil res-piration(R3)from 2005-2007 agreed well with R8 observations(R2=0.67, S.D. =0.03). Simu-lated annual net primary productivity(NPP)from 1998-2006 was 803±33 gCm-2a-1, about 4% higher than NPP observation(752±51 gCm-2a-1). Simulations of annual NEP from 2005-2007 only overestimate 9 gCm-2a-1(4%), 4 gCm-2a-1(1%)and 34 gCm-2a-1(8%)compared to NEP observations, respectively. Simulated annual foliar N concentration(FolNCon)(1.09%)is 10% lower than observed monthly FolNCon(0.87%-1.58%). Simulated annual N leaching(0.26 gNm-2)is about 10% lower than leaching observation(0.29 gNm-2). PnET-CN model valida-tion indicates that PnET-CN is capable to simulate daily GPP, annual NPP, annual NEP, monthly R,, annual FolNCon and annual nitrate N leaching for subtropical coniferous planta-tions in southem China. The results obtained from the validation test revealed that PnET-CN model can be used to simulate carbon sequestration of planted coniferous forests in southern China to a high level of precision. Sensitivity analysis suggests that great care should be taken in developing generalizations as to how forests will respond to a changing climate. PnET-CN performed satisfactorily in comparison to other models that have already been calibrated and validated in coniferous planted subtropical forests in China. Based on PnET-CN validation and its comparison to other models, future improvement of PnET-CN should focus on seasonal foliar N dynamics and the effects of water stress on autotrophic respirations in subtropical coniferous plantations in southern China.     

Intra-individual comparison of 3(R)-BMIPP and 3(S)-BMIPP isomers in humans

The racemic 15-(p-iodophenyl)-3(R,S)-methylpentadecanoic acid (BMIPP) is currently used at several centers for myocardial metabolic imaging with SPECT. Recently, the 3(R)-BMIPP isomer showed a 20%-25% higher myocardial uptake and lower liver uptake than 3(S)-BMIPP in fasted rats. The aim of this study was to determine if these differences in myocardial and liver uptake also occur in humans. METHODS: Iodine-123-labeled 3(R)-BMIPP and 3(S)-BMIPP isomers were injected at rest, on two separate days, in six patients with stable coronary artery disease. Dual-head, whole-body scintigraphy was performed 20 min and 3 hr after injection. SPECT cardiac imaging was performed 60 min after injection. RESULTS: Myocardial activity averaged (% injected dose +/- s.d.) 3.15 +/- 0.49 versus 3.01 +/- 0.44 at 20 min (p = ns) and 2.64 +/- 0.38 versus 2.55 +/- 0.41 at 3 hr postinjection (p = ns) for the 3(R)-BMIPP and 3(S)-BMIPP isomers, respectively. Liver activity averaged 9.50 +/- 1.18 versus 9.44 +/- 0.66 at 20 min and 5.33 +/- 0.64 versus 5.43 +/- 0.66 at 3 hr, respectively (p = ns). SPECT showed no difference in the distribution of the two isomers between normal and infarcted myocardium. CONCLUSION: There is no significant difference in myocardial and liver distribution of the 3(R)-BMIPP and 3(S)-BMIPP isomers in humans.     

Sleep and circadian rhythms in four orbiting astronauts

This experiment measured the sleep and circadian rhythms of four male astronauts aboard a space shuttle (STS-78) orbiting the Earth for 17 days. The space mission was specially scheduled to minimize disruptions in circadian rhythms and sleep so that the effects of space flight and microgravity per se could be studied. Data were collected in 72-h measurement blocks: one block 7 days before launch, one early within the mission (3 days after launch), one late in the mission (12 days after launch), and one 18 days after landing. Within each measurement block, all sleep was recorded both polysomnographically and by sleep diary. Core body temperature was sampled every 6 mins. Actillumes were worn continuously. All urine samples were collected separately. Performance was assessed by a computerized test battery (3/day) and by end-of-shift questionnaires (1/day); mood and alertness were measured by visual analogue scales (5/day). Circadian rhythms in orbit appeared to be very similar in phase and amplitude to those on the ground, and were appropriately aligned for the required work/rest schedule. There was no change from early flight to late flight. This was also reflected in mood, alertness, and performance scores, which were satisfactory at both in-flight time points. However, in-flight sleep showed a decreased amount of sleep obtained (mean = 6.1 h), and all four astronauts showed a decrease in delta sleep. No further degradation in sleep was seen when early flight was compared to late flight, and no other sleep parameters showed reliable trends.     

Validation of an EEG-derived spectral frequency index (SFx) for continuous monitoring of sleep depth in humans

Sleep in humans is classically assessed by recording a multichannel electroencephalogram (EEG) in connection with an electrooculogram (EOG) and an electromyogram (EMG). In general, human sleep is manually staged into 6 categories (from awake through REM sleep to stage 4 reflecting deep sleep) on the basis of a visual inspection of EEG periods (epochs) of 20 - 30 s duration. This cumbersome methodology is still used in practice and for reference purposes. - The conversion of EEG-signals by means of Fast Fourier Transformation provides objective and reproducible information reflecting specific communicative features of the central nervous system. A special part of this information based on a specific algorithm is defined by the so-called spectral frequency index (SFx). This SFx-algorithm contains relationships among some particular EEG frequencies and provides objective percentage values about the state of consciousness of a person. In order to validate this new SFx-method, sleep as a physiological state of continuous alterations of consciousness and vigilance was chosen. A total of 36 nights of sleep from 18 healthy volunteers were staged manually by a scientist unaware of the protocol. The volunteers received either placebo or lormetazepam prior to commencement of the nocturnal recordings. The manually staged data were compared with the data obtained by the SFx-analysis. Both data sets SFx values and manually staged data were made comparable by averaging their values to a basic period length of 2 min duration giving 7960 pairs of data. The SFx data for sleep were found within a range from 35% to 100%. The SFx-medians of the manually staged data from "awake" to stage 4 were found in a decending order ("awake": 83% (lower and upper quartile 78% / 87%);"REM": 68% (63%/74%),"stage 1" :63% (57%/70%),"stage 2" :51% (47%/57%), "stage 3" :44% (42%/46%) and "stage 4" :42% (40%/44%). The rank correlation coefficient between the data pairs was calculated to be 0.79 indicating a substantial matching between the manually staged score and the SFx. We therefore conclude that the SFx is a suitable and objective indicator of sleep depth in humans.     

A Study of Hogan's Model of Counselor Development and Supervision: Correction.

Reports an error in the original article "A Study of Hogan's Model of Counselor Development and Supervision" by G. N. Reising and H. M. Daniels (Journal of Counseling Psychology, 1983, Vol. 30, No. 2, pp. 235-244). 244). Errors appear in the placement of asterisks (*) denoting significance level in Tables 1 and 2. Significance levels should read as follows: For the Table 1 comparison (A vs. B): Factor 1 = as shown. For the Table 1 comparison (C vs. D): Factor 1 = ns; Factor 2 = ** (p 1983-26518-001): The construct validity and developmental structure of R. A. Hogan's (see record 196600843-001) model of counselor development and supervision were studied using a sample of 141 counseling psychology graduate student trainees, interns, and professional staff in 20 university counseling centers. Counselor development questionnaire items were developed into 2 arrangements: one based on Hogan's concepts as he organized them into levels, and another derived empirically using factor analysis. The 2 configurations were compared for their ability to predict experience level of Ss using discriminant function analysis. Each empirical factor was also examined for relationship with experience by means of 1-way ANOVA with preplanned comparisons. Results indicate that counselor development is best described by a complex rather than a simple model and that it involves factors of Anxiety/Doubt, Independence, Method/Skills Training, Work Validation, Commitment Ambivalence, and Respectful Confrontation. Developmental profiles of these issues are described, and implications for supervision and training programs are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)