1,959 research outputs found
Anchor Retouching via Model Interaction for Robust Object Detection in Aerial Images
Object detection has made tremendous strides in computer vision. Small object
detection with appearance degradation is a prominent challenge, especially for
aerial observations. To collect sufficient positive/negative samples for
heuristic training, most object detectors preset region anchors in order to
calculate Intersection-over-Union (IoU) against the ground-truthed data. In
this case, small objects are frequently abandoned or mislabeled. In this paper,
we present an effective Dynamic Enhancement Anchor (DEA) network to construct a
novel training sample generator. Different from the other state-of-the-art
techniques, the proposed network leverages a sample discriminator to realize
interactive sample screening between an anchor-based unit and an anchor-free
unit to generate eligible samples. Besides, multi-task joint training with a
conservative anchor-based inference scheme enhances the performance of the
proposed model while reducing computational complexity. The proposed scheme
supports both oriented and horizontal object detection tasks. Extensive
experiments on two challenging aerial benchmarks (i.e., DOTA and HRSC2016)
indicate that our method achieves state-of-the-art performance in accuracy with
moderate inference speed and computational overhead for training. On DOTA, our
DEA-Net which integrated with the baseline of RoI-Transformer surpasses the
advanced method by 0.40% mean-Average-Precision (mAP) for oriented object
detection with a weaker backbone network (ResNet-101 vs ResNet-152) and 3.08%
mean-Average-Precision (mAP) for horizontal object detection with the same
backbone. Besides, our DEA-Net which integrated with the baseline of ReDet
achieves the state-of-the-art performance by 80.37%. On HRSC2016, it surpasses
the previous best model by 1.1% using only 3 horizontal anchors
Kinetochore-microtubule attachment throughout mitosis potentiated by the elongated stalk of the kinetochore kinesin CENP-E
Centromere protein E (CENP-E) is a highly elongated kinesin that transports pole-proximal chromosomes during congression in prometaphase. During metaphase, it facilitates kinetochore-microtubule end-on attachment required to achieve and maintain chromosome alignment. In vitro CENP-E can walk processively along microtubule tracks and follow both growing and shrinking microtubule plus ends. Neither the CENP-E-dependent transport along microtubules nor its tip-tracking activity requires the unusually long coiled-coil stalk of CENP-E. The biological role for the CENP-E stalk has now been identified through creation of "Bonsai" CENP-E with significantly shortened stalk but wild-type motor and tail domains. We demonstrate that Bonsai CENP-E fails to bind microtubules in vitro unless a cargo is contemporaneously bound via its C-terminal tail. In contrast, both full-length and truncated CENP-E that has no stalk and tail exhibit robust motility with and without cargo binding, highlighting the importance of CENP-E stalk for its activity. Correspondingly, kinetochore attachment to microtubule ends is shown to be disrupted in cells whose CENP-E has a shortened stalk, thereby producing chromosome misalignment in metaphase and lagging chromosomes during anaphase. Together these findings establish an unexpected role of CENP-E elongated stalk in ensuring stability of kinetochore-microtubule attachments during chromosome congression and segregation
The Magnetic Phase Transition and Universality Class of h-YMnO3 and h-(Y0.98Eu0.02)MnO3 Under Zero and Applied Pressure
We investigated the antiferromagnetic phase transition in the frustrated and multiferroic
hexagonal manganites h-YMnO3 (YMO) and h-(Y0.98Eu0.02)MnO3 (YEMO). Elastic neutron scattering
was used to study, in detail, the phase transition in YMO and YEMO under zero pressure and in
YMO under a hydrostatic pressure of 1.5 GPa. Under conditions of zero pressure, we found critical
temperatures of TN = 71.3(1) K and 72.11(5) K and the critical exponent 0.22(2) and b = 0.206(3),
for YMO and YEMO, respectively. This is in agreement with earlier work by Roessli et al. Under
an applied hydrostatic pressure of 1.5 GPa, the ordering temperature increased to TN = 75.2(5) K,
in agreement with earlier reports, while b was unchanged. Inelastic neutron scattering was used to
determine the size of the anisotropy spin wave gap close to the phase transition. From spin wave
theory, the gap is expected to close with a critical exponent, b0, identical to the order parameter b.
Our results indicate that the gap in YEMO indeed closes at TN = 72.4(3) K with b0 = 0.24(2), while
the in-pressure gap in YMO closes at 75.2(5) K with an exponent of b0 = 0.19(3). In addition, the low
temperature anisotropy gap was found to have a slightly higher absolute value under pressure.
The consistent values obtained for b in the two systems support the likelihood of a new universality
class for triangular, frustrated antiferromagnets
Benzo[de]naphtho[1,8-gh]quinolines: synthesis, photophysical studies and nitro explosives detection
A rational synthetic approach to substituted naphtho[1,8-gh]quinolines using intramolecular cyclization in the presence of potassium in the series of (naphthalen-1-yl)isoquinolines is described. The photophysical properties of the obtained compounds were studied; in particular, fluorescence emission was detected in the range 454 - 482 nm with a quantum yield of up to 54%. We also calculated the HOMO-LUMO energies and optimized molecular structures for the resulting fluorophores. Based on the results of fluorescence titration, the Stern-Volmer constants (up to 21587 M-1) and the detection limits of nitroanalytes (up to 1.4 ppm) were calculated, confirming the possibility of their use as potential chemosensors for the visual detection of nitro-containing explosives
Microstructure and biodegradation performance of Mg–4Ca–1Zn based alloys after ultrasonic treatment and doping with nanodiamonds for biomedical applications
This work aims to study microstructural features, phase composition, topology, surface potential, and the biodegradation performance of Mg–4Zn–1Ca-based alloys whose melts were ultrasonically (US) treated and doped with nanodiamonds (ND). The findings show a correlation between the ratio of the secondary phase segregated along the grain boundaries and the biodegradation rate in the RPMI-1640 synthetic culture medium. The fewer Ca2Mg6Zn3 phase fraction, the lower the biodegradation rate. Also, ND doping does not significantly affect the biodegradation rate. Intriguingly, the latter in the US-treated alloy was found to be noticeably inhibited due to a smoother topography and the presence of the fewest Ca2Mg6Zn3 phase fraction segregated along the grain boundaries. Further studies are needed to assess the biodegradable potential of the ND doped alloy, which melt was ultrasonically treated
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CVID enteropathy is characterized by exceeding low mucosal IgA levels and interferon-driven inflammation possibly related to the presence of a pathobiont.
Common variable immunodeficiency (CVID), the most common symptomatic primary antibody deficiency, is accompanied in some patients by a duodenal inflammation and malabsorption syndrome known as CVID enteropathy (E-CVID).The goal of this study was to investigate the immunological abnormalities in CVID patients that lead to enteropathy as well as the contribution of intestinal microbiota to this process.We found that, in contrast to noE-CVID patients (without enteropathy), E-CVID patients have exceedingly low levels of IgA in duodenal tissues. In addition, using transkingdom network analysis of the duodenal microbiome, we identified Acinetobacter baumannii as a candidate pathobiont in E-CVID. Finally, we found that E-CVID patients exhibit a pronounced activation of immune genes and down-regulation of epithelial lipid metabolism genes. We conclude that in the virtual absence of mucosal IgA, pathobionts such as A. baumannii, may induce inflammation that re-directs intestinal molecular pathways from lipid metabolism to immune processes responsible for enteropathy
antiSMASH 4.0—improvements in chemistry prediction and gene cluster boundary identification
Many antibiotics, chemotherapeutics, crop protection agents and food preservatives originate from molecules produced by bacteria, fungi or plants. In recent years, genome mining methodologies have been widely adopted to identify and characterize the biosynthetic gene clusters encoding the production of such compounds. Since 2011, the ‘antibiotics and secondary metabolite analysis shell—antiSMASH’ has assisted researchers in efficiently performing this, both as a web server and a standalone tool. Here, we present the thoroughly updated antiSMASH version 4, which adds several novel features, including prediction of gene cluster boundaries using the ClusterFinder method or the newly integrated CASSIS algorithm, improved substrate specificity prediction for non-ribosomal peptide synthetase adenylation domains based on the new SANDPUMA algorithm, improved predictions for terpene and ribosomally synthesized and post-translationally modified peptides cluster products, reporting of sequence similarity to proteins encoded in experimentally characterized gene clusters on a per-protein basis and a domain-level alignment tool for comparative analysis of trans-AT polyketide synthase assembly line architectures. Additionally, several usability features have been updated and improved. Together, these improvements make antiSMASH up-to-date with the latest developments in natural product research and will further facilitate computational genome mining for the discovery of novel bioactive molecules
A community-maintained standard library of population genetic models
The explosion in population genomic data demands ever more complex modes of analysis, and increasingly, these analyses depend on sophisticated simulations. Recent advances in population genetic simulation have made it possible to simulate large and complex models, but specifying such models for a particular simulation engine remains a difficult and error-prone task. Computational genetics researchers currently re-implement simulation models independently, leading to inconsistency and duplication of effort. This situation presents a major barrier to empirical researchers seeking to use simulations for power analyses of upcoming studies or sanity checks on existing genomic data. Population genetics, as a field, also lacks standard benchmarks by which new tools for inference might be measured. Here, we describe a new resource, stdpopsim, that attempts to rectify this situation. Stdpopsim is a community-driven open source project, which provides easy access to a growing catalog of published simulation models from a range of organisms and supports multiple simulation engine backends. This resource is available as a well-documented python library with a simple command-line interface. We share some examples demonstrating how stdpopsim can be used to systematically compare demographic inference methods, and we encourage a broader community of developers to contribute to this growing resource.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]
U-Compare bio-event meta-service: compatible BioNLP event extraction services
AbstractBackgroundBio-molecular event extraction from literature is recognized as an important task of bio text mining and, as such, many relevant systems have been developed and made available during the last decade. While such systems provide useful services individually, there is a need for a meta-service to enable comparison and ensemble of such services, offering optimal solutions for various purposes.ResultsWe have integrated nine event extraction systems in the U-Compare framework, making them inter-compatible and interoperable with other U-Compare components. The U-Compare event meta-service provides various meta-level features for comparison and ensemble of multiple event extraction systems. Experimental results show that the performance improvements achieved by the ensemble are significant. ConclusionsWhile individual event extraction systems themselves provide useful features for bio text mining, the U-Compare meta-service is expected to improve the accessibility to the individual systems, and to enable meta-level uses over multiple event extraction systems such as comparison and ensemble.This research was partially supported by KAKENHI 18002007 [YK, MM, JDK, SP, TO, JT]; JST PRESTO and KAKENHI 21500130 [YK]; the Academy of Finland and computational resources were provided by CSC -- IT Center for Science Ltd [JB, FG]; the Research Foundation Flanders (FWO) [SVL]; UK Biotechnology and Biological Sciences, Research Council (BBSRC project BB/G013160/1 Automated Biological Event Extraction from the Literature for Drug Discovery) and JISC, National Centre for Text Mining [SA]; the Spanish grant BIO2010-17527 [MN, APM]; NIH Grant U54 DA021519 [AO, DRR]Peer Reviewe
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