Dyadic pulsations as a signature of sustainability in correspondence networks

In this paper, we introduce the concept of dyadic pulsations as a measure of sustainability in online discussion groups. Dyadic pulsations correspond to new communication exchanges occurring between two participants in a discussion group. A group that continuously integrates new participants in the on-going conversation is characterized by a steady dyadic pulsation rhythm. On the contrary, groups that either pursue close conversation or unilateral communication have no or very little dyadic pulsations. We show on two examples taken from Usenet discussion groups, that dyadic pulsations permit to anticipate future bursts in response delay time which are signs of group discussion collapses. We discuss ways of making this measure resilient to spam and other common algorithmic production that pollutes real discussion

Statistical properties of groundwater noble gas paleoclimate models: Are they robust and unbiased estimators?

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95652/1/ggge1627.pd

Influence of transient pressure changes on speech intelligibility: Implications for nextgeneration train travel

High-speed trains are operated in increasingly complex railway networks and continual improvement of driver assistance systems is necessary to maintain safety. Speech offers the opportunity to provide information to the driver without disrupting visual attention. However, it is not known whether the transient pressure changes inside trains passing through tunnels interfere with speech intelligibility. Our primary goal was to test whether the most severe pressure variations occurring in high-speed trains (25 hPa in 2 s) affect speech intelligibility in individuals with normal hearing ability and secondly whether a potential effect would depend on the direction of the pressure change. A cross-over design was used to compare speech intelligibility, measured with the monosyllable word test by Wallenberg and Kollmeier, in steady ambient pressure versus subsequent to pressure events, both realised in a pressure chamber. Since data for a power calculation did not exist, we conducted a pilot study with 20 participants to estimate variance of intra-individual differences. The upper 80% confidence limit guided sample size of the main campaign, which was performed with 72 participants to identify a 10% difference while limiting alpha (5%) and beta error (10%). On average, a participant understood 0.7 fewer words following a pressure change event compared to listening in steady ambient pressure. However, this intra-individual differences varied strongly between participants, standard deviation (SD) +/- 4.5 words, resulting in a negligible effect size of 0.1 and the Wilcoxon signed rank test (Z = -1.26; p = 0.21) did not distinguish it from chance. When comparing decreasing and increasing pressure events an average of 0.2 fewer words were understood (+/- 3.9 SD). The most severe pressure changes expected to occur in high-speed trains passing through tunnels do not interfere with speech intelligibility and are in itself not a risk factor for loss of verbal information transmission

Interindividual variabilities in cognitive performance degradation after alcohol consuption and sleep loss are related

Introduction The sleep inducing effects of alcohol as well as the increase in sleep propensity and sleepiness after sleep loss have been linked to the adenosinergic system in the brain. While the performance impairing effects of ethanol have partly been related to the inhibitory effects of cerebral adenosine, sleep loss has been found to increase adenosine receptor density. The interindividual variability of cognitive performance impairments after alcohol intake as well as after sleep loss is extensive. Thus, we examined in humans whether performance degradations resulting from sleep loss and alcohol consumption are related. Methods Performance in a 10-min Psychomotor Vigilance Task (PVT) was tested in 47 healthy volunteers (mean age 27 ± 5 (SD) years, 21 females) at 6 pm 1) after an 8 hour control night, 2) after alcohol consumption (aiming at a blood alcohol concentration (BAC) of 0.08%), and 3) after 35 hours of total sleep deprivation. After alcohol intake, 35 of the participants reached a BAC of more than 0.06% prior to the performance testing (mean BAC 0.074%, SD 0.009%, min. 0.063%, max. 0.095%) and were included in the analyses. Two recovery nights were scheduled between conditions. Results Performance impairments due to acute alcohol intake and due to 35 hours of sustained wakefulness were calculated as differences from performance under control conditions. The degree in performance degradation correlated highly between both conditions (i.e. 10% slowest reaction times: Pearson’s r=0.73, p<0.0001; standard deviation of reaction times: r=0.75, p<0.0001; mean reaction time: r=0.59, p=0.0002). Conclusions Participants whose PVT performance proved to be vulnerable to the effects of alcohol consumption were also vulnerable to sleep loss, whereas individuals who were resilient against the effects of alcohol were also less susceptible to the impact of sleep deprivation. These results suggest that the effects of alcohol and sleep deprivation on performance are mediated – at least in part – by a common pathway that may involve the adenosinergic system in the brain

Testing the noble gas paleothermometer with a yearlong study of groundwater noble gases in an instrumented monitoring well

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/94795/1/wrcr13235.pd

The effects of a tailored mindfulness-based program on the positive mental health of resident physicians: a randomized controlled trial

Objectives: Medical residency is a challenging phase that puts the mental health of resident physicians at risk. This study explores the effects of a tailored mindfulness-based program on the positive mental health of resident physicians. Methods: We conducted a longitudinal randomized controlled trial with an active control group. The intervention group took part in an 8-week mindfulness-based program (MBP) that included a course book and was followed by a 4-month maintenance phase. The control group only received the course book for self-study. Participants were assessed at 0, 2, 6, and 12 months. Assessments included self-report measures (positive affect, life-satisfaction, self-compassion, flourishing, self-esteem, feeling loved, self-attributed mindfulness, time perception, "Muße" (i.e., feeling at ease and free of pressure), thriving at work, job satisfaction, self-efficacy, self-esteem), as well as Goal Attainment Scaling. Results: A total of 147 resident physicians were randomly assigned to either the intervention or the control group. In linear mixed models, we found small to medium effects for the interaction of time × group across various time points for self-compassion, flourishing, mindfulness, Muße, thriving at work, and indirect negative affect with effect sizes ranging between d = 0.25 and 0.88. Goal Attainment Scaling revealed a greater goal attainment in the intervention group compared to the control group (d = 1.50). Conclusions: We conclude that a tailored MBP may improve certain aspects of resident physicians' positive mental health. Trial Registration: DRKS00014015 05/24/2018

Reply to comment by Klump et al. on “Noble gases and stable isotopes in a shallow aquifer in southern Michigan: Implications for noble gas paleotemperature reconstructions for cool climates”

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/94860/1/grl22429.pd