L’imagination prend le pouvoir

Le destin triste de nombreux slogans révolutionnaires, c’est qu’à un moment donné, quelqu’un les réalise de manière perverse. Cette circonstance est exploitée avec empressement par ceux qui – dès le début hostiles aux militants ou, plus souvent encore, eux-mêmes anciens militants – peuvent dire enfin : « voici votre révolution, elle n’a jamais été autre chose ». Le cas de la révolte de 68 est particulièrement évocateur. On la présente comme une rébellion de la jeunesse pleine d’élan vital con..

Sleep Timing in Late Autumn and Late Spring Associates With Light Exposure Rather Than Sun Time in College Students

Timing of the human sleep-wake cycle is determined by social constraints, biological processes (sleep homeostasis and circadian rhythmicity) and environmental factors, particularly natural and electrical light exposure. To what extent seasonal changes in the light-dark cycle affect sleep timing and how this varies between weekdays and weekends has not been firmly established. We examined sleep and activity patterns during weekdays and weekends in late autumn (standard time, ST) and late spring (daylight saving time, DST), and expressed their timing in relation to three environmental reference points: clock-time, solar noon (SN) which occurs one clock hour later during DST than ST, and the midpoint of accumulated light exposure (50% LE). Observed sleep timing data were compared to simulated data from a mathematical model for the effects of light on the circadian and homeostatic regulation of sleep. A total of 715 days of sleep timing and light exposure were recorded in 19 undergraduates in a repeated-measures observational study. During each three-week assessment, light and activity were monitored, and self-reported bed and wake times were collected. Light exposure was higher in spring than in autumn. 50% LE did not vary across season, but occurred later on weekends compared to weekdays. Relative to clock-time, bedtime, wake-time, mid-sleep, and midpoint of activity were later on weekends but did not differ across seasons. Relative to SN, sleep and activity measures were earlier in spring than in autumn. Relative to 50% LE, only wake-time and mid-sleep were later on weekends, with no seasonal differences. Individual differences in mid-sleep did not correlate with SN but correlated with 50% LE. Individuals with different habitual bedtimes responded similarly to seasonal changes. Model simulations showed that light exposure patterns are sufficient to explain sleep timing in spring but less so in autumn. The findings indicate that during autumn and spring, the timing of sleep associates with actual light exposure rather than sun time as indexed by SN

Human CD8 T cells generated in vitro from hematopoietic stem cells are functionally mature

<p>Abstract</p> <p>Background</p> <p>T cell development occurs within the highly specialized thymus. Cytotoxic CD8 T cells are critical in adaptive immunity by targeting virally infected or tumor cells. In this study, we addressed whether functional CD8 T cells can be generated fully <it>in vitro </it>using human umbilical cord blood (UCB) hematopoietic stem cells (HSCs) in coculture with OP9-DL1 cells.</p> <p>Results</p> <p>HSC/OP9-DL1 cocultures supported the differentiation of CD8 T cells, which were TCR/CD3^hiCD27^hiCD1a^negand thus phenotypically resembled mature functional CD8 single positive thymocytes. These <it>in vitro</it>-generated T cells also appeared to be conventional CD8 cells, as they expressed high levels of <it>Eomes </it>and low levels of <it>Plzf</it>, albeit not identical to <it>ex vivo </it>UCB CD8 T cells. Consistent with the phenotypic and molecular characterization, upon TCR-stimulation, <it>in vitro</it>-generated CD8 T cells proliferated, expressed activation markers (MHC-II, CD25, CD38), secreted IFN-γ and expressed Granzyme B, a cytotoxic T-cell effector molecule.</p> <p>Conclusion</p> <p>Taken together, the ability to direct human hematopoietic stem cell or T-progenitor cells towards a mature functional phenotype raises the possibility of establishing cell-based treatments for T-immunodeficiencies by rapidly restoring CD8 effector function, thereby mitigating the risks associated with opportunistic infections.</p

Sleepiness is a signal to go to bed: data and model simulations

Study Objectives Assess the validity of a subjective measure of sleepiness as an indicator of sleep drive by quantifying associations between intra-individual variation in evening sleepiness and bedtime, sleep duration, and next morning and subsequent evening sleepiness, in young adults. Methods Sleep timing and sleepiness were assessed in 19 students in late autumn and late spring on a total of 771 days. Karolinska Sleepiness Scales (KSS) were completed at half-hourly intervals at fixed clock times starting four hours prior to participants’ habitual bedtime, and in the morning. Associations between sleepiness and sleep timing were evaluated by mixed model and non-parametric approaches and simulated with a mathematical model for the homeostatic and circadian regulation of sleepiness. Results Intra-individual variation in evening sleepiness was very large, covering four or five points on the 9-point KSS scale, and was significantly associated with subsequent sleep timing. On average, a one point higher KSS value was followed by 20 min earlier bedtime, which led to 11 min longer sleep, which correlated with lower sleepiness next morning and following evening. Associations between sleepiness and sleep timing were stronger in early compared to late sleepers. Model simulations indicated that the directions of associations between sleepiness and sleep timing are in accordance with their homeostatic and circadian regulation, even though much of the variance in evening sleepiness and details of its time course remain unexplained by the model. Conclusion Subjective sleepiness is a valid indicator of the drive for sleep which, if acted upon, can reduce insufficient sleep

Using a central Vehicle Holding Compound (VHC) in an open pipeline automotive order fulfilment system: a simulation study

Satisfying requests for specific vehicle variants in a timely manner may increase profit margins for the automotive producer and automotive dealers and may reduce the need to incentivise customers financially to make a purchase. Open pipeline order fulfilment systems have emerged in the automotive sector to allow dealers to fulfil a customer in a number of ways. Not only can a dealer search its own stock for a suitable match to a customer’s requested vehicle specification, the dealer can also search for a suitable vehicle in the planning, assembly or distribution pipeline. If a suitable match cannot be found, the dealer can submit a specific Build-to-Order request to the producer. This study examines the impact of adding a central vehicle holding compound (VHC) in such a system. Any dealer can search for a suitable vehicle match in the VHC. A simulation study of a real automotive fulfilment system is conducted to examine the effects on order fulfilment performance of establishing a VHC in a specific market. The simulation model incorporates important features that affect the management and control of the fulfilment system. The study shows that establishing a VHC in an open pipeline system has a significant effect on the level of use of each fulfilment mechanism and on fulfilment performance. A VHC results in significant reductions in lead time but can increase the total stock level in the system if the VHC operating conditions are not determined carefully. The insights and implications of the findings are discussed in detail. They are valuable in providing a base line to consider investment in a VHC and to decide the most appropriate operating policies

Hearing problems in the learning disability population: is anybody listening?

We undertook this project because we believed that hearing loss experienced by the target population was greater than the referral figures suggested. Therefore, we set up a trial service initiative designed to examine the efficacy of different referral routes into audiology services for adults with learning disability. This retrospective analysis focuses on the generation of data on hearing loss on a small population sample (n = 136) gathered over a 6-month period in 2012. We suggest remedial action now to prevent more problems in the future

Distribution of Medication Considering Information, Transshipment, and Clustering: Malaria in Malawi

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/143762/1/poms12826.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/143762/2/poms12826-sup-0001-Appendix.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/143762/3/poms12826_am.pd