1,086 research outputs found
Combining technology and entrepreneurial education through design thinking: Students' reflections on the learning process
publishedVersio
Utfordringer og muligheter ved bruk av spillelementer i den entreprenørielle læringsprosessen
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Risk of depression, suicide and psychosis with hydroxychloroquine treatment for rheumatoid arthritis:a multinational network cohort study
Objectives: Concern has been raised in the rheumatology community regarding recent regulatory warnings that HCQ used in the coronavirus disease 2019 pandemic could cause acute psychiatric events. We aimed to study whether there is risk of incident depression, suicidal ideation or psychosis associated with HCQ as used for RA.Methods: We performed a new-user cohort study using claims and electronic medical records from 10 sources and 3 countries (Germany, UK and USA). RA patients ≥18 years of age and initiating HCQ were compared with those initiating SSZ (active comparator) and followed up in the short (30 days) and long term (on treatment). Study outcomes included depression, suicide/suicidal ideation and hospitalization for psychosis. Propensity score stratification and calibration using negative control outcomes were used to address confounding. Cox models were fitted to estimate database-specific calibrated hazard ratios (HRs), with estimates pooled where I2 <40%.Results: A total of 918 144 and 290 383 users of HCQ and SSZ, respectively, were included. No consistent risk of psychiatric events was observed with short-term HCQ (compared with SSZ) use, with meta-analytic HRs of 0.96 (95% CI 0.79, 1.16) for depression, 0.94 (95% CI 0.49, 1.77) for suicide/suicidal ideation and 1.03 (95% CI 0.66, 1.60) for psychosis. No consistent long-term risk was seen, with meta-analytic HRs of 0.94 (95% CI 0.71, 1.26) for depression, 0.77 (95% CI 0.56, 1.07) for suicide/suicidal ideation and 0.99 (95% CI 0.72, 1.35) for psychosis.Conclusion: HCQ as used to treat RA does not appear to increase the risk of depression, suicide/suicidal ideation or psychosis compared with SSZ. No effects were seen in the short or long term. Use at a higher dose or for different indications needs further investigation.Trial registration: Registered with EU PAS (reference no. EUPAS34497; http://www.encepp.eu/encepp/viewResource.htm? id=34498). The full study protocol and analysis source code can be found at https://github.com/ohdsi-studies/Covid19EstimationHydroxychloroquine2.</p
The NANOGrav 15-year Data Set: Bayesian Limits on Gravitational Waves from Individual Supermassive Black Hole Binaries
Evidence for a low-frequency stochastic gravitational wave background has
recently been reported based on analyses of pulsar timing array data. The most
likely source of such a background is a population of supermassive black hole
binaries, the loudest of which may be individually detected in these datasets.
Here we present the search for individual supermassive black hole binaries in
the NANOGrav 15-year dataset. We introduce several new techniques, which
enhance the efficiency and modeling accuracy of the analysis. The search
uncovered weak evidence for two candidate signals, one with a
gravitational-wave frequency of 4 nHz, and another at 170 nHz. The
significance of the low-frequency candidate was greatly diminished when
Hellings-Downs correlations were included in the background model. The
high-frequency candidate was discounted due to the lack of a plausible host
galaxy, the unlikely astrophysical prior odds of finding such a source, and
since most of its support comes from a single pulsar with a commensurate binary
period. Finding no compelling evidence for signals from individual binary
systems, we place upper limits on the strain amplitude of gravitational waves
emitted by such systems.Comment: 23 pages, 13 figures, 2 tables. Accepted for publication in
Astrophysical Journal Letters as part of Focus on NANOGrav's 15-year Data Set
and the Gravitational Wave Background. For questions or comments, please
email [email protected]
How to Detect an Astrophysical Nanohertz Gravitational-Wave Background
Analysis of pulsar timing data have provided evidence for a stochastic
gravitational wave background in the nHz frequency band. The most plausible
source of such a background is the superposition of signals from millions of
supermassive black hole binaries. The standard statistical techniques used to
search for such a background and assess its significance make several
simplifying assumptions, namely: i) Gaussianity; ii) isotropy; and most often
iii) a power-law spectrum. However, a stochastic background from a finite
collection of binaries does not exactly satisfy any of these assumptions. To
understand the effect of these assumptions, we test standard analysis
techniques on a large collection of realistic simulated datasets. The dataset
length, observing schedule, and noise levels were chosen to emulate the
NANOGrav 15-year dataset. Simulated signals from millions of binaries drawn
from models based on the Illustris cosmological hydrodynamical simulation were
added to the data. We find that the standard statistical methods perform
remarkably well on these simulated datasets, despite their fundamental
assumptions not being strictly met. They are able to achieve a confident
detection of the background. However, even for a fixed set of astrophysical
parameters, different realizations of the universe result in a large variance
in the significance and recovered parameters of the background. We also find
that the presence of loud individual binaries can bias the spectral recovery of
the background if we do not account for them.Comment: 14 pages, 8 figure
Telomerecat: A ploidy-agnostic method for estimating telomere length from whole genome sequencing data.
Telomere length is a risk factor in disease and the dynamics of telomere length are crucial to our understanding of cell replication and vitality. The proliferation of whole genome sequencing represents an unprecedented opportunity to glean new insights into telomere biology on a previously unimaginable scale. To this end, a number of approaches for estimating telomere length from whole-genome sequencing data have been proposed. Here we present Telomerecat, a novel approach to the estimation of telomere length. Previous methods have been dependent on the number of telomeres present in a cell being known, which may be problematic when analysing aneuploid cancer data and non-human samples. Telomerecat is designed to be agnostic to the number of telomeres present, making it suited for the purpose of estimating telomere length in cancer studies. Telomerecat also accounts for interstitial telomeric reads and presents a novel approach to dealing with sequencing errors. We show that Telomerecat performs well at telomere length estimation when compared to leading experimental and computational methods. Furthermore, we show that it detects expected patterns in longitudinal data, repeated measurements, and cross-species comparisons. We also apply the method to a cancer cell data, uncovering an interesting relationship with the underlying telomerase genotype
The NANOGrav 15-year Data Set: Evidence for a Gravitational-Wave Background
We report multiple lines of evidence for a stochastic signal that is
correlated among 67 pulsars from the 15-year pulsar-timing data set collected
by the North American Nanohertz Observatory for Gravitational Waves. The
correlations follow the Hellings-Downs pattern expected for a stochastic
gravitational-wave background. The presence of such a gravitational-wave
background with a power-law-spectrum is favored over a model with only
independent pulsar noises with a Bayes factor in excess of , and this
same model is favored over an uncorrelated common power-law-spectrum model with
Bayes factors of 200-1000, depending on spectral modeling choices. We have
built a statistical background distribution for these latter Bayes factors
using a method that removes inter-pulsar correlations from our data set,
finding (approx. ) for the observed Bayes factors in the
null no-correlation scenario. A frequentist test statistic built directly as a
weighted sum of inter-pulsar correlations yields (approx. ). Assuming a fiducial
characteristic-strain spectrum, as appropriate for an ensemble of binary
supermassive black-hole inspirals, the strain amplitude is (median + 90% credible interval) at a reference frequency of
1/(1 yr). The inferred gravitational-wave background amplitude and spectrum are
consistent with astrophysical expectations for a signal from a population of
supermassive black-hole binaries, although more exotic cosmological and
astrophysical sources cannot be excluded. The observation of Hellings-Downs
correlations points to the gravitational-wave origin of this signal.Comment: 30 pages, 18 figures. Published in Astrophysical Journal Letters as
part of Focus on NANOGrav's 15-year Data Set and the Gravitational Wave
Background. For questions or comments, please email [email protected]
The James Webb Space Telescope Mission
Twenty-six years ago a small committee report, building on earlier studies,
expounded a compelling and poetic vision for the future of astronomy, calling
for an infrared-optimized space telescope with an aperture of at least .
With the support of their governments in the US, Europe, and Canada, 20,000
people realized that vision as the James Webb Space Telescope. A
generation of astronomers will celebrate their accomplishments for the life of
the mission, potentially as long as 20 years, and beyond. This report and the
scientific discoveries that follow are extended thank-you notes to the 20,000
team members. The telescope is working perfectly, with much better image
quality than expected. In this and accompanying papers, we give a brief
history, describe the observatory, outline its objectives and current observing
program, and discuss the inventions and people who made it possible. We cite
detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space
Telescope Overview, 29 pages, 4 figure
Evaluating the Effects of SARS-CoV-2 Spike Mutation D614G on Transmissibility and Pathogenicity.
Global dispersal and increasing frequency of the SARS-CoV-2 spike protein variant D614G are suggestive of a selective advantage but may also be due to a random founder effect. We investigate the hypothesis for positive selection of spike D614G in the United Kingdom using more than 25,000 whole genome SARS-CoV-2 sequences. Despite the availability of a large dataset, well represented by both spike 614 variants, not all approaches showed a conclusive signal of positive selection. Population genetic analysis indicates that 614G increases in frequency relative to 614D in a manner consistent with a selective advantage. We do not find any indication that patients infected with the spike 614G variant have higher COVID-19 mortality or clinical severity, but 614G is associated with higher viral load and younger age of patients. Significant differences in growth and size of 614G phylogenetic clusters indicate a need for continued study of this variant
Clinical Sequencing Exploratory Research Consortium: Accelerating Evidence-Based Practice of Genomic Medicine
Despite rapid technical progress and demonstrable effectiveness for some types of diagnosis and therapy, much remains to be learned about clinical genome and exome sequencing (CGES) and its role within the practice of medicine. The Clinical Sequencing Exploratory Research (CSER) consortium includes 18 extramural research projects, one National Human Genome Research Institute (NHGRI) intramural project, and a coordinating center funded by the NHGRI and National Cancer Institute. The consortium is exploring analytic and clinical validity and utility, as well as the ethical, legal, and social implications of sequencing via multidisciplinary approaches; it has thus far recruited 5,577 participants across a spectrum of symptomatic and healthy children and adults by utilizing both germline and cancer sequencing. The CSER consortium is analyzing data and creating publically available procedures and tools related to participant preferences and consent, variant classification, disclosure and management of primary and secondary findings, health outcomes, and integration with electronic health records. Future research directions will refine measures of clinical utility of CGES in both germline and somatic testing, evaluate the use of CGES for screening in healthy individuals, explore the penetrance of pathogenic variants through extensive phenotyping, reduce discordances in public databases of genes and variants, examine social and ethnic disparities in the provision of genomics services, explore regulatory issues, and estimate the value and downstream costs of sequencing. The CSER consortium has established a shared community of research sites by using diverse approaches to pursue the evidence-based development of best practices in genomic medicine
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