Authors' perceptions of electronic publishing: two cross sectional surveys

Objectives To evaluate how acceptable authors find the BMJ''s current practice of publishing short versions of research articles in the paper journal and a longer version on the web and to determine authors'' attitudes towards publishing only abstracts in the paper journal and publishing unedited versions on bmj.com once papers have been accepted for publication.Design Two cross sectional surveys.Setting General medical journal.Participants Survey 1: corresponding authors of a consecutive sample of published BMJ research articles that had undergone the ELPS (electronic long, paper short) process. Survey 2: corresponding authors of consecutive research articles submitted to BMJ.Results Response rates were 90% (104/115) in survey 1 and 75% (213/283) in survey 2. ELPS is largely acceptable to BMJ authors, but there is some concern that electronic information is not permanent and uncertainty about how versions are referenced. While authors who had experienced ELPS reported some problems with editors shortening papers, most were able to rectify these. Overall, 70% thought that the BMJ should continue to use ELPS; 49% thought that publishing just the abstract in the printed journal with the full version only on bmj.com was unacceptable; and 23% thought it unacceptable to post unedited versions on bmj.com once a paper had been accepted for publication.Conclusions It is acceptable to authors to publish short versions of research articles in the printed version of a general medical journal with longer versions on the website. Authors dislike the idea of publishing only abstracts in the printed journal but are in favour of posting accepted articles on the website ahead of the printed version.     

Dreaming and insomnia: Polysomnographic correlates of reported dream recall frequency.

This study assesses which polysomnographic variables are associated with changes in reported dream recall frequency in patients meeting diagnostic criteria for primary insomnia. Data analyzed included sleep latency, total sleep time, sleep efficiency, time in REM, time in sleep stages (1&2 vs. 3&4), and periodic limb movement. For the grouping meeting ICD-10 diagnostic criteria for primary insomnia, a significant decrease in dream recall was found compared to the noninsomniac group. A decline in polysomnographic sleep quality was associated with a decline in reported dream or nightmare recall frequency. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Temperature of the cerebral cortex and its connection with the egg in white rats in free behavior

In chronic experiments on rats in free behavior thermistors have been used to record the temperature of the cerebral sensomotor cortex together with recording of the EEG of the neocortex and hippocampus. The sensitivity of recording of temperature was 10^–2 deg/cm. Detailed comparison of the temperature variations with changes in the EEG in "slow" and "rapid" sleep and also alertness revealed a correlation between the appearance of the hippocampal -rhythm (short bursts and long periods in the alert state and in "rapid" sleep), on the one hand, and temperature rises of greater or lesser intensity (maximum on passing from "rapid" sleep), on the other. On desynchronization of the EEG without hippocampal -synchronization no rise in temperature in the brain was observed. In "slow" sleep various forms of correlation between the EEG and the temperature of the cortex were noted: slow, smooth temperature drop developing with growth of synchronization; appearance against the background of this drop of short temperature rises the ascending phase of which corresponded to the period of rise in synchronization and a temperature drop phase corresponding to the period of desynchronization in the microcycles of slow sleep; disappearance of such temperature fluctuations after desynchronization before the onset of "rapid" sleep. Thus, the link between the fluctuations in brain temperature and its electrogenesis is of a complex character with clear correspondence between the rise in temperature and the on-set of the hippocampal -rhythm.N. I Grashchenkov Laboratory of Problems of Control of Functions in the Human and Animal Body, Academy of Sciences of the USSR, Moscow. Translated from Neirofiziologiya, Vol. 2, No. 6, pp. 618–626, November–December, 1970.     

Why Publishing Everything Is More Effective than Selective Publishing of Statistically Significant Results

Background

De Winter and Happee [1] examined whether science based on selective publishing of significant results may be effective in accurate estimation of population effects, and whether this is even more effective than a science in which all results are published (i.e., a science without publication bias). Based on their simulation study they concluded that “selective publishing yields a more accurate meta-analytic estimation of the true effect than publishing everything, (and that) publishing nonreplicable results while placing null results in the file drawer can be beneficial for the scientific collective” (p.4).

Methods and Findings

Using their scenario with a small to medium population effect size, we show that publishing everything is more effective for the scientific collective than selective publishing of significant results. Additionally, we examined a scenario with a null effect, which provides a more dramatic illustration of the superiority of publishing everything over selective publishing.

Conclusion

Publishing everything is more effective than only reporting significant outcomes.     

Speaking from the heart: cardiovascular components of stress rating changes and the relative reactivity of physiological and psychological variables

The first part of the experiment compared the relative reactivity of various cardiovascular measurements and self-reported assessment of mental arithmetic, an active coping stress task. It was found that the self-reported stres rating was more responsive (student's t=9.4) than the physiological measurements. Among the cardiovascular indices, heart rate was the most responsive (student's t=6.5), followed by the interval between R-wave and the maximal systolic pressure (student's t=5.0). The second part of the study used a multiple regression to examine the cardiovascular components of change in stres rating following mental arithmetic. Both resting (psychophysiological trait varibles) and change under stress (psychophysiological state variables) were used to predict change in stress rating. Stress rating increase were associated with greater maximal systolic pressure rate of rise (finger dP/dt) at baseline and less heart rate increase during mental arithmetic, yielding a multiple r of 0.67. The dual autonomic nature of active coping stress response is discussed. The shortcomings of using a correlate of a correlate are noted.     

A New Neurocognitive Theory of Dreams

Discoveries in three distinct areas of dream research make it possible to suggest the outlines of a new neurocognitive theory of dreaming. The first relevant findings come from assessments of patients with brain injuries, which show that lesions in different areas have differential effects on dreaming and thereby imply the contours of the neural network necessary for dreaming. The second set of results comes from work with children ages 3–15 in the sleep laboratory, which reveals that only 20–30% of REM period awakenings lead to dream reports up to age 9 and that the dreams of children under age 5 are bland and static in content. The third set of findings comes from a rigorous system of content analysis, which demonstrates the repetitive nature of much dream content and that dream content in general is continuous with waking conceptions and emotional preoccupations. Based on these findings, dreaming is best understood as a developmental cognitive achievement that depends upon the maturation and maintenance of a specific network of forebrain structures. The output of this neural network for dreaming is guided by a continuity principle linked to current personal concerns on the one hand and a repetition principle rooted in past emotional preoccupations on the other.     

Suppression of electroencephalogram Δ power density during non-rapid eye movement sleep as a result of a prolonged cognitive task prior to sleep onset

The effects of a prolonged cognitive task prior to sleep onset on subsequent sleep patterns were examined in 14 healthy subjects who were randomly assigned to two conditions. Those assigned to a working condition were asked to engage in a prolonged cognitive task until close to bedtime (0200 hours), whereas those assigned to a relaxing condition were instructed to perform the same task during the daytime and then to stay awake in a relaxed state until the same bedtime as the work group. Visual scoring of sleep stages showed no significant differences in the amounts of stage 4 and slow wave sleep (stage 3+4) between the two conditions. Power spectrum analysis of sleep electroencephalogram (EEG) revealed that the EEG (0.5–4.0 Hz) power density in the first non-rapid eye movement (REM)-REM sleep cycle was significantly lower following the prolonged cognitive task prior to sleep onset than following the relaxed wakefulness and that the decreased EEG power density in the first sleep cycle was not compensated for during the later part of the sleep. These findings would indicate that the prolonged cognitive task prior to sleep onset may suppress EEG power density during subsequent sleep, suggesting that such a task may interfere with the development of deep non-REM sleep.     

Prediction of individual oxygen uptake on-step transients from frequency responses

Power-oxygen uptake ( ) frequency responses can be used to predict responses to arbitrary exercise intensity patterns. It is still an open question for which range of exercise intensities such computed response patterns yield valid predictions. In the present study, we determined the power- frequency response of nine sports students by means of pseudo-randomised switching between 20 W and 80 W during upright and supine cycle exercise. Starting from a baseline of 20 W each subject also performed sustained step increases to 40 W, 80 W, 120 W, and 160 W in both positions. The individual step responses were then compared with the expected time-courses predicted on the basis of the individual frequency responses. The comparison showed a close agreement for the 20 W–40 W and 20 W–80 W steps in both positions. With larger step amplitudes the kinetics became increasingly slower than the predicted time course in both positions. During additional ramp tests (10 W · 30 s^–1) whole blood lactic acid concentration [1a^–]_b tended to be higher in the supine position at exercise intensities higher than 160 W. The mean power at 4 mmol · 1^–1 [la^–]_b amounted to 234 (SD 32) W and 253 (SD 44) W (P<5%) in the supine and the upright position, respectively. The maximal oxygen uptake relative to body mass was not found to be significantly different [upright, mean 57 (SD 10) ml · (min · kg)^–1;supine, mean 54 (SD 10) ml · (min · kg)]. These findings would suggest that for a range of mild exercise intensities kinetics are not appreciably influenced by the step amplitude or by cardiovascular changes associated with the upright and the supine position.     

A Laboratory Study of Sleep and Dreaming in a Case of Asperger's Syndrome

Asperger's Syndrome (AS) is a pervasive developmental disorder whose continuity with High-Functioning Autism is still a matter of debate. Clinical observations suggest that patients with AS may present the same sleep disorders as autistic patients, including difficulties in initiating and maintaining sleep as well as poor dream recall. We recorded the sleep of a 25-year-old male patient with AS for two nights using a full EEG montage and compared the second night to that of a group of normal participants. We found low levels of slow wave sleep (SWS: stages 3 + 4), high levels of stage 1, and a large number of awakenings. The organization of REM sleep was unremarkable, including normal REM density. Analyses of phasic EEG events revealed a very low incidence of sleep spindles and a normal number of K-complexes over bilateral frontal and central EEG leads. In order to collect dream reports, the patient was awakened three times over two nights following at least 15 minutes of REM sleep in each case. On each occasion the patient was not aware of any mental activity happening just prior to awakening. These observations are discussed with regards to the connections that may exist between EEG sleep spindle activity, selective attention, and the capacity to generate a dream report.     

Identifying and Utilizing Spiritual Content in Dream Reports

The question posed by this investigation was whether the spiritual content of dreams could be identified. The Casto Spirituality Scoring System (CSSS) was used to identify spiritual elements in 1,666 dream reports obtained in dream workshops in six countries. The CSSS considers the adjective spiritual as a hypothetical construct referring to one's focus on, and/or reverence, openness, and connectedness to something of significance believed to be beyond one's full understanding and/or individual existence. The research question was answered affirmatively. All dream reports were scored by two judges working independently for spiritual objects, settings, activities, emotions, and experiences, with an overall reliability of no less than .90 per item. The collection of dream reports with the highest percentage of spiritual content came from Brazil. This investigation includes quantitative analyses and examples of dream reports in each of the categories identified. It also discusses the therapeutic use of dreams with spiritual content.     

Does Dream Interpretation Have Any Limits? An Evaluation of Interpretations of the Dream of “Irma's Injection”

Dream interpretative efforts appear unconstrained by methodological standards. An examination of the re-interpretations of Freud's dream of Irma's Injection, the dream specimen of psychoanalysis, illustrates the undisciplined nature of dream interpretation. Reading in from presumed day residues or infantile experiences rather than out from the dream report per se lies at the heart of the problem. The failure to spell out inferences, to link inferences to the dream text, to explain and maintain the relationships in the dream report, and to offer a substitute text for the entire dream text all contribute to the inadequacies of dream interpreatation.     

On-Call Duty Effects on Sleep-State Physiological Stability in Male Medical Interns

Background

On-call duty among medical interns is characterized by sleep deprivation and stressful working conditions, both of which alter cardiac autonomic modulation. We hypothesized that sleep stability decreased in medical interns during on-call duty. We used cardiopulmonary-coupling (CPC) analysis to test our hypothesis.

Methods

We used electrocardiogram (ECG)-based CPC analysis to quantify physiological parameters of sleep stability in 13 medical interns during on-call and on-call duty-free periods. There were ten 33.5-h on-call duty shifts per month for interns, each followed by 2 on-call duty-free days, over 3 months. Measurements during sleep were collected before, during, and after an on-call shift. Measurements were repeated 3 months later during an on-call duty-free period.

Results

The medical interns had significantly reduced stable sleep, and displayed increased latency to the first epoch of stable sleep during the on-call night shift, compared to the pre-call and on-call duty-free nights. Interns also had significantly increased rapid-eye-movement (REM) sleep during the on-call night shift, compared to the pre-call and on-call duty-free nights.

Conclusion

Medical interns suffer disrupted sleep stability and continuity during on-call night shifts. The ECG-based CPC analysis provides a straightforward means to quantify sleep quality and stability in medical staff performing shift work under stressful conditions.     

The Risks of Sleeping “Too Much”. Survey of a National Representative Sample of 24671 Adults (INPES Health Barometer)

Background

A significant U-shaped association between sleep duration and several morbidity (obesity, diabetes or cardiovascular disease) and mortality risks has been regularly reported. However, although the physiological pathways and risks associated with “too short sleep” (<5 hours/day) have been well demonstrated, little is known about “too much sleeping”.

Purpose

To explore socio-demographic characteristics and comorbidities of “long sleepers” (over 10 hours/day) from a nationally representative sample of adults.

Methods

A cross-sectional nationally representative sample of 24,671 subjects from 15 to 85-year-old. An estimated total sleep time (TST) on non-leisure days was calculated based on a specifically designed sleep log which allows to distinguish “long sleepers” from “short sleepers” (<5 hours/day). Insomnia was assessed according to the International classification of sleep disorders (ICSD-2).

Results

The average TST was 7 hours and 13 minutes (+/− 17 minutes). Six hundred and twelve subjects were “long sleepers” (2.7%) and 1969 “short sleepers” (7.5%). Compared to the whole group, “long sleepers” were more often female, younger (15–25 year-old) or older (above 65 year-old), with no academic degree, mostly clerks and blue collar workers. “Long sleepers” were significantly more likely to have psychiatric diseases and a greater body mass index (BMI). However, long sleep was not significantly associated with the presence of any other chronic medical disease assessed. Conversely, short sleep duration was significantly associated with almost all the other chronic diseases assessed.

Conclusions

In the general population, sleeping too much was associated with psychiatric diseases and higher BMI, but not with other chronic medical diseases.     

Sleep/Wake Dynamics Changes during Maturation in Rats

Objectives

Conventional scoring of sleep provides little information about the process of transitioning between vigilance states. We applied the state space technique (SST) using frequency band ratios to follow normal maturation of different sleep/wake states, velocities of movements, and transitions between states of juvenile (postnatal day 34, P34) and young adult rats (P71).

Design

24-h sleep recordings of eight P34 and nine P71 were analyzed using conventional scoring criteria and SST one week following implantation of telemetric transmitter. SST is a non-categorical approach that allows novel quantitative and unbiased examination of vigilance-states dynamics and state transitions. In this approach, behavioral changes are described in a 2-dimensional state space that is derived from spectral characteristics of the electroencephalography.

Measurements and Results

With maturation sleep intensity declines, the duration of deep slow wave sleep (DSWS) and light slow wave sleep (LSWS) decreases and increases, respectively. Vigilance state determination, as a function of frequency, is not constant; there is a substantial shift to higher ratio 1 in all vigilance states except DSWS. Deep slow wave sleep decreases in adult relative to juvenile animals at all frequencies. P71 animals have 400% more trajectories from Wake to LSWS (p = 0.005) and vice versa (p = 0.005), and 100% more micro-arousals (p = 0.021), while trajectories from LSWS to DSWS (p = 0.047) and vice versa (p = 0.033) were reduced by 60%. In both juvenile and adult animals, no significant changes were found in sleep velocity at all regions of the 2-dimensional state space plot; suggesting that maturation has a partial effect on sleep stability.

Conclusions

Here, we present novel and original evidence that SST enables visualization of vigilance-state intensity, transitions, and velocities that were not evident by traditional scoring methods. These observations provide new perspectives in sleep state dynamics and highlight the usefulness of this technique in exploring the development of sleep-wake activity.     

Counting statistics of 1/f fluctuations in neuronal spike trains

The mesencephalic reticular formation (MRF) neurons are regarded as contributing to the activation of the celebral cortex. In this paper, the statistical features of single neuronal activities in MRF of cat during dream sleep are investigated; the neuronal spike train exhibits 1/f fluctuations. Counting statistics is applied to the neuronal spike train giving rise to a variance/mean curve which follows at -law. For an interpretation of these findings, the clustering Poisson process is applied which not only gives rise to at -law but also suggests a generation mechanism. The MRF neuronal activities are closely fitted by the clustering Poisson process and the underlying statistical parameters can be estimated. These findings strongly suggest that neuronal activities can be interpreted as superposition of randomly occuring clusters ( = bursts of spikes).