Decline of long-range temporal correlations in the human brain during sustained wakefulness

Sleep is crucial for daytime functioning, cognitive performance and general well-being. These aspects of daily life are known to be impaired after extended wake, yet, the underlying neuronal correlates have been difficult to identify. Accumulating evidence suggests that normal functioning of the brain is characterized by long-range temporal correlations (LRTCs) in cortex, which are supportive for decision-making and working memory tasks. Here we assess LRTCs in resting state human EEG data during a 40-hour sleep deprivation experiment by evaluating the decay in autocorrelation and the scaling exponent of the detrended fluctuation analysis from EEG amplitude fluctuations. We find with both measures that LRTCs decline as sleep deprivation progresses. This decline becomes evident when taking changes in signal power into appropriate consideration. Our results demonstrate the importance of sleep to maintain LRTCs in the human brain. In complex networks, LRTCs naturally emerge in the vicinity of a critical state. The observation of declining LRTCs during wake thus provides additional support for our hypothesis that sleep reorganizes cortical networks towards critical dynamics for optimal functioning

Exploring Features for Predicting Policy Citations

In this study we performed an initial investigation and evaluation of altmetrics and their relationship with public policy citation of research papers. We examined methods for using altmetrics and other data to predict whether a research paper is cited in public policy and applied receiver operating characteristic curve on various feature groups in order to evaluate their potential usefulness. From the methods we tested, classifying based on tweet count provided the best results, achieving an area under the ROC curve of 0.91.Comment: 2 pages, accepted to JCDL '1

CRISPR Cas9 in Pancreatic Cancer Research

Pancreatic cancer is now becoming a common cause of cancer death with no significant change in patient survival over the last 10 years. The main treatment options for pancreatic cancer patients are surgery, radiation therapy and chemotherapy, but there is now considerable effort to develop new and effective treatments. In recent years, CRISPR/Cas9 technology has emerged as a powerful gene editing tool with promise, not only as an important research methodology, but also as a new and effective method for targeted therapy. In this review, we summarize current advances in CRISPR/Cas9 technology and its application to pancreatic cancer research, and importantly as a means of selectively targeting key drivers of pancreatic cancer

Admissible invariant similar tests for instrumental variables regression

March 12, 200

Behavioural plasticity compensates for adaptive loss of cricket song

Funding: Funding was provided by UK Natural Environment Research Council grants to N.W.B. (NE/L011255/1, NE/T000619/1) and a University of St Andrews School of Biology PhD studentship to W.T.S.Behavioural flexibility might help animals cope with costs of genetic variants under selection, promoting genetic adaptation. However, it has proven challenging to experimentally link behavioural flexibility to the predicted compensation of population-level fitness. We tested this prediction using the field cricket Teleogryllus oceanicus. In Hawaiian populations, a mutation silences males and protects against eavesdropping parasitoids. To examine how the loss of this critical acoustic communication signal impacts offspring production and mate location, we developed a high- resolution, individual-based tracking system for low-light, naturalistic conditions. Offspring production did not differ significantly in replicate silent versus singing populations, and fitness compensation in silent conditions was associated with significantly increased locomotion in both sexes. Our results provide evidence that flexible behaviour can promote genetic adaptation via compensation in reproductive output and suggest that rapid evolution of animal communication systems may be less constrained than previously appreciated.Peer reviewe

Exploring the Chemical Composition and Double Horizontal Branch of the Bulge Globular Cluster NGC 6569

Photometric and spectroscopic analyses have shown that the Galactic bulge cluster Terzan 5 hosts several populations with different metallicities and ages that manifest as a double red horizontal branch (HB). A recent investigation of the massive bulge cluster NGC 6569 revealed a similar, though less extended, HB luminosity split, but little is known about the cluster's detailed chemical composition. Therefore, we have used high-resolution spectra from the Magellan-M2FS and VLT-FLAMES spectrographs to investigate the chemical compositions and radial velocity distributions of red giant branch and HB stars in NGC 6569. We found the cluster to have a mean heliocentric radial velocity of -48.8 km/s (sigma = 5.3 km/s; 148 stars) and a mean [Fe/H] =-0.87 dex (19 stars), but the cluster's 0.05 dex [Fe/H] dispersion precludes a significant metallicity spread. NGC 6569 exhibits light- and heavy-element distributions that are common among old bulge/inner Galaxy globular clusters, including clear (anti)correlations between [O/Fe], [Na/Fe], and [Al/Fe]. The light-element data suggest that NGC 6569 may be composed of at least two distinct populations, and the cluster's low mean [La/Eu] = -0.11 dex indicates significant pollution with r-process material. We confirm that both HBs contain cluster members, but metallicity and light-element variations are largely ruled out as sources for the luminosity difference. However, He mass fraction differences as small as delta Y ~ 0.02 cannot be ruled out and may be sufficient to reproduce the double HB.Comment: 72 pages, 14 figures, 8 tables; published in The Astronomical Journal; electronic versions of all tables are available in the published versio

Collaborative virtual 3D environment for internet-accessible physics experiments

Immersive 3D worlds have increasingly raised the interest of researchers and practitioners for various learning and training settings over the last decade. These virtual worlds can provide multiple communication channels between users and improve presence and awareness in the learning process. Consequently virtual 3D environments facilitate collaborative learning and training scenarios. In this paper we focus on the integration of internet accessible physics experiments (iLabs) combined with the TEALsim 3D simulation toolkit in Project Wonderland, Sun's toolkit for creating collaborative 3D virtual worlds. Within such a collaborative environment these tools provide the opportunity for teachers and students to work together as avatars as they control actual equipment, visualize physical phenomenon generated by the experiment, and discuss the results. In particular we will outline the steps of integration, future goals, as well as the value of a collaboration space in Wonderland's virtual world

A Chemical Composition Survey of the Iron-Complex Globular Cluster NGC 6273 (M 19)

Recent observations have shown that a growing number of the most massive Galactic globular clusters contain multiple populations of stars with different [Fe/H] and neutron-capture element abundances. NGC 6273 has only recently been recognized as a member of this "iron-complex" cluster class, and we provide here a chemical and kinematic analysis of > 300 red giant branch (RGB) and asymptotic giant branch (AGB) member stars using high resolution spectra obtained with the Magellan-M2FS and VLT-FLAMES instruments. Multiple lines of evidence indicate that NGC 6273 possesses an intrinsic metallicity spread that ranges from about [Fe/H] = -2 to -1 dex, and may include at least three populations with different [Fe/H] values. The three populations identified here contain separate first (Na/Al-poor) and second (Na/Al-rich) generation stars, but a Mg-Al anti-correlation may only be present in stars with [Fe/H] > -1.65. The strong correlation between [La/Eu] and [Fe/H] suggests that the s-process must have dominated the heavy element enrichment at higher metallicities. A small group of stars with low [alpha/Fe] is identified and may have been accreted from a former surrounding field star population. The cluster's large abundance variations are coupled with a complex, extended, and multimodal blue horizontal branch (HB). The HB morphology and chemical abundances suggest that NGC 6273 may have an origin that is similar to omega Cen and M 54.Comment: Accepted for Publication in The Astrophysical Journal; 50 pages; 18 figures; 8 tables; higher resolution figures are available upon request or in the published journal articl

Investigating Driver Evasive Maneuvers of Takeover Responses in Automated Vehicles

When an automated vehicle (AV) is about to crash, would the speed of the AV (slow vs. fast) affect the steering direction of a human driver who attempts to control the vehicle and avoid the collision? Answering this question provides AV manufacturers insight into how they can produce a safer AV experience for human drivers. Considering that a left turn at a T-intersection allows a greater time budget to make the turn than a right turn which requires sharper steering, we hypothesized that drivers traveling at faster speeds would be more likely to turn left and drivers traveling at moderately slow speeds would turn right to avoid a collision. To test these hypotheses, we conducted a driving simulator experiment where participants monitored the AV’s status throughout the driving. We manipulated the speed of the AV when it crashes at a T-intersection (approximately 7 m/s vs. 11 m/s). Our results indicated that the speed of the vehicle had no impact on the steering direction. Interestingly, however, drivers displayed an overall inclination towards right turns to avoid collision at the T-intersection regardless of speed conditions. Keywords: automated vehicle (AV), speed, right turn, left turn, T-intersectio