The Electronic and Superconducting Properties of Oxygen-Ordered MgB2 compounds of the form Mg2B3Ox

Possible candidates for the Mg2B3Ox nanostructures observed in bulk of polycrystalline MgB2 (Ref.1) have been studied using a combination of Z-contrast imaging, electron energy loss spectroscopy (EELS) and first-principles calculations. The electronic structures, phonon modes, and electron phonon coupling parameters are calculated for two oxygen-ordered MgB2 compounds of composition Mg2B3O and Mg2B3O2, and compared with those of MgB2. We find that the density of states for both Mg2B3Ox structures show very good agreement with EELS, indicating that they are excellent candidates to explain the observed coherent oxygen precipitates. Incorporation of oxygen reduces the transition temperature and gives calculated TC values of 18.3 K and 1.6 K for Mg2B3O and Mg2B3O2, respectively.Comment: Submitted to PR

Limiting the effects of earthquakes on gravitational-wave interferometers

Ground-based gravitational wave interferometers such as the Laser Interferometer Gravitational-wave Observatory (LIGO) are susceptible to high-magnitude teleseismic events, which can interrupt their operation in science mode and significantly reduce the duty cycle. It can take several hours for a detector to stabilize enough to return to its nominal state for scientific observations. The down time can be reduced if advance warning of impending shaking is received and the impact is suppressed in the isolation system with the goal of maintaining stable operation even at the expense of increased instrumental noise. Here we describe an early warning system for modern gravitational-wave observatories. The system relies on near real-time earthquake alerts provided by the U.S. Geological Survey (USGS) and the National Oceanic and Atmospheric Administration (NOAA). Hypocenter and magnitude information is generally available in 5 to 20 minutes of a significant earthquake depending on its magnitude and location. The alerts are used to estimate arrival times and ground velocities at the gravitational-wave detectors. In general, 90\% of the predictions for ground-motion amplitude are within a factor of 5 of measured values. The error in both arrival time and ground-motion prediction introduced by using preliminary, rather than final, hypocenter and magnitude information is minimal. By using a machine learning algorithm, we develop a prediction model that calculates the probability that a given earthquake will prevent a detector from taking data. Our initial results indicate that by using detector control configuration changes, we could prevent interruption of operation from 40-100 earthquake events in a 6-month time-period

Pirnilu Nintipungkupayi (Everyone Is a Teacher): Keeping Old People's Spirit Healthy Through Education

In the Ngaanyatjarra Lands of desert Western Australia, older people are being encouraged to participate meaningfully in student education. This initiative is being led by two of the authors of this article, senior Ngaanyatjarra women, both of whom work with the Ngaanyatjarra Lands School with its campuses in eight remote communities spread over hundreds of kilometres. Elderly men and women, some of whom are residents in the Ngaanyatjarra Aged Care home (Ngaanyatjarra Health Service, 2021), are eagerly participating in the planning of bush trips, gathering their traditional resources, seeds, grinding stones, bush resins, recalling stories, songs, and dances - as they prepare for the bush camps with students. During the camps the schoolteachers step back and the elderly lead in what is known as two‐way science. At first glance, this work may look like it is simply focused on the educational needs of students with senior Yarnangu acting in a supporting role. However, this article will demonstrate the continuous connections and responsibilities, laid out in the Tjukurrpa (the Dreaming), between the old and the young, to their ancestral lands. It sets out how according to "Tjukurrpa thinking," the principal way to provide good care is by helping senior people remain on country with family, pass on their knowledge to younger people, and thus keep strong languages and kurrunpa (people's spirit) alive

Artificial escape from XCI by DNA methylation editing of the CDKL5 gene.

A significant number of X-linked genes escape from X chromosome inactivation and are associated with a distinct epigenetic signature. One epigenetic modification that strongly correlates with X-escape is reduced DNA methylation in promoter regions. Here, we created an artificial escape by editing DNA methylation on the promoter of CDKL5, a gene causative for an infantile epilepsy, from the silenced X-chromosomal allele in human neuronal-like cells. We identify that a fusion of the catalytic domain of TET1 to dCas9 targeted to the CDKL5 promoter using three guide RNAs causes significant reactivation of the inactive allele in combination with removal of methyl groups from CpG dinucleotides. Strikingly, we demonstrate that co-expression of TET1 and a VP64 transactivator have a synergistic effect on the reactivation of the inactive allele to levels >60% of the active allele. We further used a multi-omics assessment to determine potential off-targets on the transcriptome and methylome. We find that synergistic delivery of dCas9 effectors is highly selective for the target site. Our findings further elucidate a causal role for reduced DNA methylation associated with escape from X chromosome inactivation. Understanding the epigenetics associated with escape from X chromosome inactivation has potential for those suffering from X-linked disorders

Author correction:Senescence of song revealed by a long-term study of the Seychelles warbler (<i>Acrocephalus sechellensis</i>) (Scientific Reports, (2020), 10, 1, (20479), 10.1038/s41598-020-77405-3)

An amendment to this paper has been published and can be accessed via a link at the top of the paper.</jats:p

Beyond the Power Law: Uncovering Stylized Facts in Interbank Networks

We use daily data on bilateral interbank exposures and monthly bank balance sheets to study network characteristics of the Russian interbank market over Aug 1998 - Oct 2004. Specifically, we examine the distributions of (un)directed (un)weighted degree, nodal attributes (bank assets, capital and capital-to-assets ratio) and edge weights (loan size and counterparty exposure). We search for the theoretical distribution that fits the data best and report the "best" fit parameters. We observe that all studied distributions are heavy tailed. The fat tail typically contains 20% of the data and can be mostly described well by a truncated power law. Also the power law, stretched exponential and log-normal provide reasonably good fits to the tails of the data. In most cases, however, separating the bulk and tail parts of the data is hard, so we proceed to study the full range of the events. We find that the stretched exponential and the log-normal distributions fit the full range of the data best. These conclusions are robust to 1) whether we aggregate the data over a week, month, quarter or year; 2) whether we look at the "growth" versus "maturity" phases of interbank market development; and 3) with minor exceptions, whether we look at the "normal" versus "crisis" operation periods. In line with prior research, we find that the network topology changes greatly as the interbank market moves from a "normal" to a "crisis" operation period.Comment: 17 pages, 9 figure

Data and Safety Monitoring Boards: Some Enduring Questions

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75571/1/j.1748-720X.2009.00410.x.pd

Circadian variation in renal blood flow and kidney function in healthy volunteers monitored using non-invasive magnetic resonance imaging

Circadian regulation of kidney function is involved in maintaining whole-body homeostasis and dysfunctional circadian rhythm can potentially be involved in disease development. Magnetic Resonance Imaging (MRI)provides reliable and reproducible repetitive estimates of kidney function non-invasively without the risk of adverse events associated with contrast agents and ionizing radiation. The purpose of this study was to estimate circadian variations in kidney function in healthy human subjects using MRI, and relate the findings with urinary excretions of electrolytes and markers of kidney function.Phase Contrast imaging, Arterial Spin Labeling and Blood Oxygen Level DependentR2*-mapping were used to assess the total renal blood flow and regional perfusion,and intrarenal oxygenation in eight female and eight male healthy volunteers every fourth hour during a 24hperiod. Parallel with MRI scans, standard urinary and plasma parameters were quantified. Significant circadian variations of total renal blood flow were found over 24hwith increasing flow from noon to midnight and decreasing flow during the night. In contrast, no circadian variation in intrarenal oxygenation was detected.Urinary excretions of electrolytes, osmotically active particles, creatinine and urea all displayed circadian variations, peaking during the afternoon and evening hours.In conclusion, total renal blood flow and kidney function, as estimated from excretion of electrolytes and waste products, display profound circadian variations, whereas intrarenal oxygenation displays significantly less circadian variation