434 research outputs found
tissue of rat adjuvant-induced arthritis
Triptolide has been clinically used to treat patients with rheumatoid arthritis, in which chemokine receptors play an important role in immune and inflammatory responses. To investigate the effect of triptolide on CCR5, we used complete Freund’s adjuvant to produce adjuvant-induced arthritis (AIA) in rats. Our data show that both CCR5 mRNA and protein levels in synovial tissue of rats with AIA are significantly higher than those in normal rats. Triptolide can significantly inhibit rat AIA-induced overexpression of CCR5 at both mRNA and protein levels. These results may contribute to better understanding of the therapeutic effects of triptolide in rheumatoid arthritis. Key words: triptolide, CCR5, adjuvant induced arthritis, rheumatoid arthriti
Regularized Evolution for Image Classifier Architecture Search
The effort devoted to hand-crafting neural network image classifiers has
motivated the use of architecture search to discover them automatically.
Although evolutionary algorithms have been repeatedly applied to neural network
topologies, the image classifiers thus discovered have remained inferior to
human-crafted ones. Here, we evolve an image classifier---AmoebaNet-A---that
surpasses hand-designs for the first time. To do this, we modify the tournament
selection evolutionary algorithm by introducing an age property to favor the
younger genotypes. Matching size, AmoebaNet-A has comparable accuracy to
current state-of-the-art ImageNet models discovered with more complex
architecture-search methods. Scaled to larger size, AmoebaNet-A sets a new
state-of-the-art 83.9% / 96.6% top-5 ImageNet accuracy. In a controlled
comparison against a well known reinforcement learning algorithm, we give
evidence that evolution can obtain results faster with the same hardware,
especially at the earlier stages of the search. This is relevant when fewer
compute resources are available. Evolution is, thus, a simple method to
effectively discover high-quality architectures.Comment: Accepted for publication at AAAI 2019, the Thirty-Third AAAI
Conference on Artificial Intelligenc
The Fourteenth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the extended Baryon Oscillation Spectroscopic Survey and from the second phase of the Apache Point Observatory Galactic Evolution Experiment
The fourth generation of the Sloan Digital Sky Survey (SDSS-IV) has been in
operation since July 2014. This paper describes the second data release from
this phase, and the fourteenth from SDSS overall (making this, Data Release
Fourteen or DR14). This release makes public data taken by SDSS-IV in its first
two years of operation (July 2014-2016). Like all previous SDSS releases, DR14
is cumulative, including the most recent reductions and calibrations of all
data taken by SDSS since the first phase began operations in 2000. New in DR14
is the first public release of data from the extended Baryon Oscillation
Spectroscopic Survey (eBOSS); the first data from the second phase of the
Apache Point Observatory (APO) Galactic Evolution Experiment (APOGEE-2),
including stellar parameter estimates from an innovative data driven machine
learning algorithm known as "The Cannon"; and almost twice as many data cubes
from the Mapping Nearby Galaxies at APO (MaNGA) survey as were in the previous
release (N = 2812 in total). This paper describes the location and format of
the publicly available data from SDSS-IV surveys. We provide references to the
important technical papers describing how these data have been taken (both
targeting and observation details) and processed for scientific use. The SDSS
website (www.sdss.org) has been updated for this release, and provides links to
data downloads, as well as tutorials and examples of data use. SDSS-IV is
planning to continue to collect astronomical data until 2020, and will be
followed by SDSS-V.Comment: SDSS-IV collaboration alphabetical author data release paper. DR14
happened on 31st July 2017. 19 pages, 5 figures. Accepted by ApJS on 28th Nov
2017 (this is the "post-print" and "post-proofs" version; minor corrections
only from v1, and most of errors found in proofs corrected
Reconstruction of primary vertices at the ATLAS experiment in Run 1 proton–proton collisions at the LHC
This paper presents the method and performance of primary vertex reconstruction in proton–proton collision data recorded by the ATLAS experiment during Run 1 of the LHC. The studies presented focus on data taken during 2012 at a centre-of-mass energy of √s=8 TeV. The performance has been measured as a function of the number of interactions per bunch crossing over a wide range, from one to seventy. The measurement of the position and size of the luminous region and its use as a constraint to improve the primary vertex resolution are discussed. A longitudinal vertex position resolution of about 30μm is achieved for events with high multiplicity of reconstructed tracks. The transverse position resolution is better than 20μm and is dominated by the precision on the size of the luminous region. An analytical model is proposed to describe the primary vertex reconstruction efficiency as a function of the number of interactions per bunch crossing and of the longitudinal size of the luminous region. Agreement between the data and the predictions of this model is better than 3% up to seventy interactions per bunch crossing
Brainformers: Trading Simplicity for Efficiency
Transformers are central to recent successes in natural language processing
and computer vision. Transformers have a mostly uniform backbone where layers
alternate between feed-forward and self-attention in order to build a deep
network. Here we investigate this design choice and find that more complex
blocks that have different permutations of layer primitives can be more
efficient. Using this insight, we develop a complex block, named Brainformer,
that consists of a diverse sets of layers such as sparsely gated feed-forward
layers, dense feed-forward layers, attention layers, and various forms of layer
normalization and activation functions. Brainformer consistently outperforms
the state-of-the-art dense and sparse Transformers, in terms of both quality
and efficiency. A Brainformer model with 8 billion activated parameters per
token demonstrates 2x faster training convergence and 5x faster step time
compared to its GLaM counterpart. In downstream task evaluation, Brainformer
also demonstrates a 3% higher SuperGLUE score with fine-tuning compared to GLaM
with a similar number of activated parameters. Finally, Brainformer largely
outperforms a Primer dense model derived with NAS with similar computation per
token on fewshot evaluations
Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector
A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements
BigSSL: Exploring the Frontier of Large-Scale Semi-Supervised Learning for Automatic Speech Recognition
We summarize the results of a host of efforts using giant automatic speech
recognition (ASR) models pre-trained using large, diverse unlabeled datasets
containing approximately a million hours of audio. We find that the combination
of pre-training, self-training and scaling up model size greatly increases data
efficiency, even for extremely large tasks with tens of thousands of hours of
labeled data. In particular, on an ASR task with 34k hours of labeled data, by
fine-tuning an 8 billion parameter pre-trained Conformer model we can match
state-of-the-art (SoTA) performance with only 3% of the training data and
significantly improve SoTA with the full training set. We also report on the
universal benefits gained from using big pre-trained and self-trained models
for a large set of downstream tasks that cover a wide range of speech domains
and span multiple orders of magnitudes of dataset sizes, including obtaining
SoTA performance on many public benchmarks. In addition, we utilize the learned
representation of pre-trained networks to achieve SoTA results on non-ASR
tasks.Comment: 14 pages, 7 figures, 13 tables; v2: minor corrections, reference
baselines and bibliography updated; v3: corrections based on reviewer
feedback, bibliography update
Causal associations of sleep traits with cancer incidence and mortality
To explore the correlation and causality between multidimensional sleep traits and pan-cancer incidence and mortality among patients with cancer. The multivariable Cox regression, linear and nonlinear Mendelian randomization (MR), and survival curve analyses were conducted to assess the impacts of chronotype, sleep duration, and insomnia symptoms on pan-cancer risk (N = 326,417 from United Kingdom Biobank) and mortality (N = 23,956 from United Kingdom Biobank). In the Cox regression, we observed a linear and J-shaped association of sleep duration with pan-cancer incidence and mortality among cancer patients respectively. In addition, there was a positive association of insomnia with pan-cancer incidence (HR, 1.03, 95% CI: 1.00–1.06, p = 0.035), all-cause mortality (HR, 1.17, 95% CI: 1.06–1.30, p = 0.002) and cancer mortality among cancer patients (HR, 1.25, 95% CI: 1.11–1.41, p < 0.001). In the linear MR, there was supporting evidence of positive associations between long sleep duration and pan-cancer incidence (OR, 1.41, 95% CI: 1.08–1.84, p = 0.012), and there was a positive association between long sleep duration and all-cause mortality in cancer patients (OR, 5.56, 95% CI: 3.15–9.82, p = 3.42E-09). Meanwhile, a strong association between insomnia and all-cause mortality in cancer patients (OR, 1.41, 95% CI: 1.27–1.56, p = 4.96E-11) was observed in the linear MR. These results suggest that long sleep duration and insomnia play important roles in pan-cancer risk and mortality among cancer patients. In addition to short sleep duration and insomnia, our findings highlight the effect of long sleep duration in cancer prevention and prognosis
Widespread Horizontal Gene Transfer from Circular Single-stranded DNA Viruses to Eukaryotic Genomes
<p>Abstract</p> <p>Background</p> <p>In addition to vertical transmission, organisms can also acquire genes from other distantly related species or from their extra-chromosomal elements (plasmids and viruses) via horizontal gene transfer (HGT). It has been suggested that phages represent substantial forces in prokaryotic evolution. In eukaryotes, retroviruses, which can integrate into host genome as an obligate step in their replication strategy, comprise approximately 8% of the human genome. Unlike retroviruses, few members of other virus families are known to transfer genes to host genomes.</p> <p>Results</p> <p>Here we performed a systematic search for sequences related to circular single-stranded DNA (ssDNA) viruses in publicly available eukaryotic genome databases followed by comprehensive phylogenetic analysis. We conclude that the replication initiation protein (Rep)-related sequences of geminiviruses, nanoviruses and circoviruses have been frequently transferred to a broad range of eukaryotic species, including plants, fungi, animals and protists. Some of the transferred viral genes were conserved and expressed, suggesting that these genes have been coopted to assume cellular functions in the host genomes. We also identified geminivirus-like and parvovirus-like transposable elements in genomes of fungi and lower animals, respectively, and thereby provide direct evidence that eukaryotic transposons could derive from ssDNA viruses.</p> <p>Conclusions</p> <p>Our discovery extends the host range of circular ssDNA viruses and sheds light on the origin and evolution of these viruses. It also suggests that ssDNA viruses act as an unforeseen source of genetic innovation in their hosts.</p
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