| 1. |
- Axelsson, John, et al.
(författare)
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Sleepiness and performance in response to repeated sleep restriction and subsequent recovery during semi-laboratory conditions.
- 2008
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Ingår i: Chronobiol Int. - : Informa UK Limited. - 1525-6073 .- 0742-0528. ; 25:2, s. 297-308
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Tidskriftsartikel (refereegranskat)abstract
- Sleepiness and performance in response to repeated sleep restriction and subsequent recovery during semi-laboratory conditions.Axelsson J, Kecklund G, Akerstedt T, Donofrio P, Lekander M, Ingre M.Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden. john.axelsson@ki.seThere is an ongoing debate of how best to measure the effects of sleep loss in a reliable and feasible way, partly because well controlled laboratory studies and field studies have come to different conclusions. The aims of the present study were to investigate both sleepiness and performance in response to long-term sleep restriction and recovery in a semi-laboratory environment, investigate order effects (i.e., whether levels return to baseline) in a study with seven days of recovery, and characterize individual differences in tolerance to restricted sleep. Nine healthy men (age 23-28 yrs) participated in the protocol, which included one habituation day (sleep 23:00-07:00 h), two baseline days (23:00-07:00 h), five days with restricted sleep (03:00-07:00 h), and seven recovery days (23:00-07:00 h). Participants went outdoors at least twice each day. Reaction-time tests were performed at 08:00, 14:00, and 20:00 h each day in the laboratory. Sleepiness was self-rated by the Karolinska Sleepiness Scale (KSS)after each test. The mixed-effect regression models showed that each day of restricted sleep resulted in an increase of sleepiness by 0.64+/- .05 KSS units (a nine-step scale, p < .001), increase of median reaction times of 6.6+/- 1.6 ms ( p = .003), and increase of lapses/test of 0.69 +/- .16 ms ( p < .001). Seven days of recovery allowed participants to return to the baseline for sleepiness and median reaction time, but not for lapses.The individual differences were larger for performance measures than for sleepiness; the between-subject standard deviation for the random intercept was in the magnitude of the effects of 1.1 days of restricted sleep for sleepiness, 6.6 days of restricted sleep for median reaction time, and 3.2 days for lapses. In conclusion, the present study shows that sleepiness is closely related to sleep pressure, while performance measures, to a larger extent, appear determined by specific individual traits. Moreover, it is suggested to measure sleepiness in a standardized situation so as to minimize the influences of contextual factors.
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| 2. |
- Barbato, Giuseppe, et al.
(författare)
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EFFECTS OF PROLONGED WAKEFULNESS : THE ROLE OF PERIOD3 GENOTYPES AND PERSONALITY TRAITS
- 2013
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Ingår i: Psychological Reports. - : AMMONS SCIENTIFIC, LTD. - 0033-2941 .- 1558-691X. ; 113:2, s. 540-551
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Tidskriftsartikel (refereegranskat)abstract
- The roles of personality traits, as assessed by Eysenck Personality Inventory, and of the clock gene PERIOD3 (PER3) were analysed on the subjective effects of prolonged wakefulness. A sample of 70 healthy participants (7 men, 63 women; M age = 24.2 yr., SD = 3.2) was studied during forced wakefulness between 7:30 p.m. and 9:30 a.m. According to Eysenck's arousal model, it was hypothesized that prolonged wakefulness might affect in a different way those classified as Introverted and Extraverted. During the forced wakefulness period, the Introverted group showed greater decrease in subjective measures of vigilance than did the Extraverted group, but no differences were observed between groups with high and low scores on Psychoticism and Neuroticism. Prolonged wakefulness had a negative effect on subjective sleepiness and mood in all three PER3 polymorphisms analysed.
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| 3. |
- Carney, Rebecca, 1990-, et al.
(författare)
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Neuromorphic Kalman filter implementation in IBM's TrueNorth
- 2017
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Ingår i: 22nd International Conference on Computing in High Energy and Nuclear Physics (CHEP2016). - : Institute of Physics (IOP).
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Konferensbidrag (refereegranskat)abstract
- Following the advent of a post-Moore’s law field of computation, novel architectures continue to emerge. With composite, multi-million connection neuromorphic chips like IBM’s TrueNorth, neural engineering has now become a feasible technology in this novel computing paradigm. High Energy Physics experiments are continuously exploring new methods of computation and data handling, including neuromorphic, to support the growing challenges of the field and be prepared for future commodity computing trends. This work details the first instance of a Kalman filter implementation in IBM’s neuromorphic architecture, TrueNorth, for both parallel and serial spike trains. The implementation is tested on multiple simulated systems and its performance is evaluated with respect to an equivalent non-spiking Kalman filter. The limits of the implementation are explored whilst varying the size of weight and threshold registers, the number of spikes used to encode a state, size of neuron block for spatial encoding, and neuron potential reset schemes.
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| 4. |
- Conte, Francesca, et al.
(författare)
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High sleep fragmentation parallels poor subjective sleep quality during the third wave of the Covid-19 pandemic : An actigraphic study
- 2021
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Ingår i: Journal of Sleep Research. - : Wiley. - 0962-1105 .- 1365-2869.
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Tidskriftsartikel (refereegranskat)abstract
- Studies on sleep during the Covid-19 pandemic have mostly been conducted during the first wave of contagion (spring 2020). To follow up on two Italian studies addressing subjective sleep features during the second wave (autumn 2020), here we assess sleep during the third wave (spring 2021) in a sample of healthy adults from Campania (Southern Italy). Actigraphic data (on 2 nights) and the Pittsburgh Sleep Quality Index were collected from 82 participants (40 F, mean age: 32.5 +/- 11.5 years) from 11 March to 18 April 2021, when Campania was classified as a red zone, i.e. it was subjected to strict restrictions, only slightly looser than those characterizing the first national lockdown (spring 2020). Although objective sleep duration and architecture appeared in the normal range, the presence of disrupted sleep was indexed by a relevant degree of sleep fragmentation (number of awakenings >= 1 min: 12.7 +/- 6.12; number of awakenings >= 5 min: 3.04 +/- 1.52), paralleled by poor subjective sleep quality (Pittsburgh Sleep Quality Index global score: 5.77 +/- 2.58). These data suggest that the relevant subjective sleep impairments reported during the first wave could have relied on subtle sleep disruptions that were undetected by the few objective sleep studies from the same period. Taken together with sleep data on previous phases of the pandemic, our findings show that the detrimental effects on sleep determined by the initial pandemic outbreak have not abated across the subsequent waves of contagion, and highlight the need for interventions addressing sleep health in global emergencies.
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| 5. |
- De Rosa, Oreste, et al.
(författare)
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Habitual Videogame Playing Does Not Compromise Subjective Sleep Quality and Is Associated with Improved Daytime Functioning
- 2023
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Ingår i: Brain Sciences. - : MDPI. - 2076-3425. ; 13:2
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Tidskriftsartikel (refereegranskat)abstract
- Research on the effects of videogames (VGs) on health has produced mixed results. Here, we assess the relationships of VG playing with sleep; chronotype; sleepiness; and levels of depression, anxiety, and stress; and how they are modulated by the level of exposure to VGs. Four hundred-and two adult participants (age = 26.2 +/- 7.84; 227 F) completed an online survey including questions on VG use and a set of standardized questionnaires. The sample was divided into three groups: habitual gamers (HGs, 42.2%), nonhabitual gamers (NHGs, 36.5%), and non-gamers (NGs, 21.3%). No between-group differences emerged in sleepiness (Epworth Sleepiness Scale) or Pittsburgh Sleep Quality Index measures except the sleep disturbances subscore, which was higher in NHGs. HGs showed delayed bed- and risetimes and higher eveningness (reduced Morningness-Eveningness Questionnaire). HGs and NHGs showed higher depression subscores (Depression Anxiety Stress Scale) but remained in the subclinical range. Moreover, hours/week of VG playing predicted delayed sleep timing, lower daytime dysfunction, and lower sleepiness. Our data suggest that VG playing does not necessarily compromise sleep quality and may even benefit daytime functioning, underlining the need to reconsider the relationships between VG use and health by taking into account possible modulating factors such as habitual VG exposure.
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| 6. |
- D'Onofrio, Paolo, et al.
(författare)
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The Polysomnographical Meaning of Changed Sleep Quality-A Study of Treatment with Reduced Time in Bed
- 2023
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Ingår i: Brain Sciences. - : MDPI. - 2076-3425. ; 13:10
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Tidskriftsartikel (refereegranskat)abstract
- Background: Reports of poor sleep are widespread, but their link with objective sleep (polysomnography-PSG) is weak in cross-sectional studies. In contrast, the purpose of this study was to investigate the association between changes in subjective and objective sleep variables using data from a study of the reduction in time in bed (TIB). Methods: One sleep recording was carried out at baseline and one at treatment week 5 (end of treatment) (N = 34). Results: The Karolinska Sleep Quality Index improved and was correlated with improvement in sleep efficiency (r = 0.41, p < 0.05) and reduction in TIB (r = -0.47, p < 0.01) and sleep latency (r = 0.36, p < 0.05). The restorative sleep index showed similar results. Improvements in the insomnia severity index (ISI) essentially lacked correlations with changes in the PSG variables. It was suggested that the latter may be due to the ISI representing a week of subjective sleep experience, of which a single PSG night may not be representative. Conclusions: It was concluded that changes in the subjective ratings of sleep are relatively well associated with changes in the PSG-based sleep continuity variables when both describe the same sleep.
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| 7. |
- Ferrucci, Veronica, et al.
(författare)
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Metastatic group 3 medulloblastoma is driven by PRUNE1 targeting NME1–TGF-β–OTX2–SNAIL via PTEN inhibitio
- 2018
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Ingår i: Brain. - : Oxford University Press (OUP). - 0006-8950 .- 1460-2156. ; 141:5, s. 1300-1319
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Tidskriftsartikel (refereegranskat)abstract
- Genetic modifications during development of paediatric groups 3 and 4 medulloblastoma are responsible for their highly metastatic properties and poor patient survival rates. PRUNE1 is highly expressed in metastatic medulloblastoma group 3, which is characterized by TGF-β signalling activation, c-MYC amplification, and OTX2 expression. We describe the process of activation of the PRUNE1 signalling pathway that includes its binding to NME1, TGF-β activation, OTX2 upregulation, SNAIL (SNAI1) upregulation, and PTEN inhibition. The newly identified small molecule pyrimido-pyrimidine derivative AA7.1 enhances PRUNE1 degradation, inhibits this activation network, and augments PTEN expression. Both AA7.1 and a competitive permeable peptide that impairs PRUNE1/NME1 complex formation, impair tumour growth and metastatic dissemination in orthotopic xenograft models with a metastatic medulloblastoma group 3 cell line (D425-Med cells). Using whole exome sequencing technology in metastatic medulloblastoma primary tumour cells, we also define 23 common ‘non-synonymous homozygous’ deleterious gene variants as part of the protein molecular network of relevance for metastatic processes. This PRUNE1/TGF-β/OTX2/PTEN axis, together with the medulloblastoma-driver mutations, is of relevance for future rational and targeted therapies for metastatic medulloblastoma group 3.
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| 8. |
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| 9. |
- Nilsonne, Gustav, et al.
(författare)
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A multimodal brain imaging dataset on sleep deprivation in young and old humans
- 2017
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The Stockholm Sleepy Brain Study I is a functional brain imaging study of 48 younger (20-30 years) and 36 older (65-75 years) healthy participants, with magnetic resonance imaging after normal sleep and partial sleep deprivation in a crossover design. We performed experiments investigating emotional mimicry, empathy for pain, and cognitive reappraisal, as well as resting state functional magnetic resonance imaging (fMRI). We also acquired T1- and T2-weighted structural images and diffusion tensor images (DTI). On the night before imaging, participants were monitored with ambulatory polysomnography and were instructed to sleep either as usual or only three hours. Participants came to the scanner the following evening. Besides MRI scanning, participants underwent behavioral tests and contributed blood samples, which have been stored in a biobank and used for DNA analyses. Participants also completed a variety of self-report measures. The resulting multimodal dataset may be useful for hypothesis generation or independent validation of effects of sleep deprivation and aging, as well as investigation of cross-sectional associations between the different outcomes. V. 2 of this manuscript published 2017-10-12. Changes: new co-author (Claus Lamm), changed affiliations for Kristoffer Månsson, minor changes in the abstract, and revisions of the main text and figures.
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| 10. |
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