1,816 research outputs found
Diffuse emission of TeV Neutrinos and Gamma-rays from young pulsars by Photo-meson interaction in the galaxy
It's generally believed that young and rapidly rotating pulsars are important
sites of particle's acceleration, in which protons can be accelerated to
relativistic energy above the polar cap region if the magnetic moment is
antiparallel to the spin axis(). To obtain the
galactic diffusive neutrinos and gamma-rays for TeV, firstly,we use Monte
Carlo(MC) method to generate a sample of young pulsars with ages less than
yrs in our galaxy ; secondly, the neutrinos and high-energy gamma-rays
can be produced through photomeson process with the interaction of energetic
protons and soft X-ray photons () for single pulsar, and these X-ray photons come from the
neutron star surface. The results suggest that the diffusive TeV flux of
neutrinos are lower than background flux, which indicated it is difficult to be
detected by the current neutrino telescopes.Comment: 11pages,6figures. arXiv admin note: text overlap with arXiv:0812.1845
by other author
Cinchonidinium chloride monohydrate
In the title salt, C19H23N2O+·Cl−·H2O, the ions and the water molecule are held together by O—H⋯Cl, N—H⋯Cl, O—H⋯O, O—H⋯N and C—H⋯Cl hydrogen bonds, forming a three-dimensional framework. The vinyl group is disordered over two orientations with refined occupancies of 0.564 (16) and 0.436 (16). The cell parameters of the title compound have been reported previously [Griffiths (1952 ▶). Acta Cryst.
5, 290–291]
Multiple genetic switches spontaneously modulating bacterial mutability
Background: All life forms need both high genetic stability to survive as species and a degree of mutability to evolve for adaptation, but little is known about how the organisms balance the two seemingly conflicting aspects of life: genetic stability and mutability. The DNA mismatch repair (MMR) system is essential for maintaining genetic stability and defects in MMR lead to high mutability. Evolution is driven by genetic novelty, such as point mutation and lateral gene transfer, both of which require genetic mutability. However, normally a functional MMR system would strongly inhibit such genomic changes. Our previous work indicated that MMR gene allele conversion between functional and non-functional states through copy number changes of small tandem repeats could occur spontaneously via slipped-strand mis-pairing during DNA replication and therefore may play a role of genetic switches to modulate the bacterial mutability at the population level. The open question was: when the conversion from functional to defective MMR is prohibited, will bacteria still be able to evolve by accepting laterally transferred DNA or accumulating mutations? Results: To prohibit allele conversion, we "locked" the MMR genes through nucleotide replacements. We then scored changes in bacterial mutability and found that Salmonella strains with MMR locked at the functional state had significantly decreased mutability. To determine the generalizability of this kind of mutability 'switching' among a wider range of bacteria, we examined the distribution of tandem repeats within MMR genes in over 100 bacterial species and found that multiple genetic switches might exist in these bacteria and may spontaneously modulate bacterial mutability during evolution. Conclusions: MMR allele conversion through repeats-mediated slipped-strand mis-pairing may function as a spontaneous mechanism to switch between high genetic stability and mutability during bacterial evolution.Evolutionary BiologyGenetics & HereditySCI(E)9ARTICLEnull1
Learning the Relation between Similarity Loss and Clustering Loss in Self-Supervised Learning
Self-supervised learning enables networks to learn discriminative features
from massive data itself. Most state-of-the-art methods maximize the similarity
between two augmentations of one image based on contrastive learning. By
utilizing the consistency of two augmentations, the burden of manual
annotations can be freed. Contrastive learning exploits instance-level
information to learn robust features. However, the learned information is
probably confined to different views of the same instance. In this paper, we
attempt to leverage the similarity between two distinct images to boost
representation in self-supervised learning. In contrast to instance-level
information, the similarity between two distinct images may provide more useful
information. Besides, we analyze the relation between similarity loss and
feature-level cross-entropy loss. These two losses are essential for most deep
learning methods. However, the relation between these two losses is not clear.
Similarity loss helps obtain instance-level representation, while feature-level
cross-entropy loss helps mine the similarity between two distinct images. We
provide theoretical analyses and experiments to show that a suitable
combination of these two losses can get state-of-the-art results. Code is
available at https://github.com/guijiejie/ICCL.Comment: This paper is accepted by IEEE Transactions on Image Processin
Risk of post-traumatic epilepsy after severe head injury in patients with at least one seizure
Effects of ac-field amplitude on the dielectric susceptibility of relaxors
The thermally activated flips of the local spontaneous polarization in
relaxors were simulated to investigate the effects of the applied-ac-field
amplitude on the dielectric susceptibility. It was observed that the
susceptibility increases with increasing the amplitude at low temperatures. At
high temperatures, the susceptibility experiences a plateau and then drops. The
maximum in the temperature dependence of susceptibility shifts to lower
temperatures when the amplitude increases. A similarity was found between the
effects of the amplitude and frequency on the susceptibility.Comment: 8 pages, 7 figures, Phys. Rev. B (in July 1st
EMMNet: Sensor Networking for Electricity Meter Monitoring
Smart sensors are emerging as a promising technology for a large number of application domains. This paper presents a collection of requirements and guidelines that serve as a basis for a general smart sensor architecture to monitor electricity meters. It also presents an electricity meter monitoring network, named EMMNet, comprised of data collectors, data concentrators, hand-held devices, a centralized server, and clients. EMMNet provides long-distance communication capabilities, which make it suitable suitable for complex urban environments. In addition, the operational cost of EMMNet is low, compared with other existing remote meter monitoring systems based on GPRS. A new dynamic tree protocol based on the application requirements which can significantly improve the reliability of the network is also proposed. We are currently conducting tests on five networks and investigating network problems for further improvements. Evaluation results indicate that EMMNet enhances the efficiency and accuracy in the reading, recording, and calibration of electricity meters
Determination of Decabrominated Diphenyl Ether in Soils by Soxhlet Extraction and High Performance Liquid Chromatography
This study described the development of a method based on soxhlet extraction combining high performance liquid chromatography (soxhlet-HPLC) for the accurate detection of BDE-209 in soils. The solvent effect of working standard solutions in HPLC was discussed. Results showed that 1 : 1 of methanol and acetone was the optimal condition which could totally dissolve the BDE-209 in environmental samples and avoid the decrease of the peak area and the peak deformation difference of BDE-209 in HPLC. The preliminary experiment was conducted on the configured grassland (1 μg/g) to validate the method feasibility. The method produced reliable reproducibility, simulated soils (n=4) RSD 1.0%, and was further verified by the analysis e-waste contaminated soils, RSD range 5.9–11.4%. The contamination level of BDE-209 in burning site was consistent with the previous study of Longtang town but lower than Guiyu town, and higher concentration of BDE-209 in paddy field mainly resulted from the long-standing disassembling area nearby. This accurate and fast method was successfully developed to extract and analyze BDE-209 in soil samples, showing its potential use for replacing GC to determinate BDE-209 in soil samples
Toll‐like receptor‐mediated IRE1α activation as a therapeutic target for inflammatory arthritis
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/102185/1/embj2013183-sup-0004-SourceData-S4.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/102185/2/embj2013183-sup-0001.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/102185/3/embj2013183-sup-0008-SourceData-S8.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/102185/4/embj2013183-sup-0005-SourceData-S5.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/102185/5/embj2013183-sup-0001-SourceData-S1.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/102185/6/embj2013183-sup-0009-SourceData-S9.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/102185/7/embj2013183-sup-0006-SourceData-S6.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/102185/8/embj2013183-sup-0002-SourceData-S2.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/102185/9/embj2013183-sup-0010-SourceData-S10.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/102185/10/embj2013183-sup-0007-SourceData-S7.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/102185/11/embj2013183-sup-0003-SourceData-S3.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/102185/12/embj2013183.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/102185/13/embj2013183.reviewer_comments.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/102185/14/embj2013183-sup-0011-SourceData-S11.pd
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