249 research outputs found
Learning Image Aesthetics by Learning Inpainting
Due to the high capability of learning robust features, convolutional neural networks (CNN) are becoming a mainstay solution for many computer vision problems, including aesthetic quality assessment (AQA). However, there remains the issue that learning with CNN requires time-consuming and expensive data annotations especially for a task like AQA. In this paper, we present a novel approach to AQA that incorporates self-supervised learning (SSL) by learning how to inpaint images according to photographic rules such as rules-of-thirds and visual saliency. We conduct extensive quantitative experiments on a variety of pretext tasks and also different ways of masking patches for inpainting, reporting fairer distribution-based metrics. We also show the suitability and practicality of the inpainting task which yielded comparably good benchmark results with much lighter model complexit
Single-virion sequencing of lamivudine-treated HBV populations reveal population evolution dynamics and demographic history.
BACKGROUND: Viral populations are complex, dynamic, and fast evolving. The evolution of groups of closely related viruses in a competitive environment is termed quasispecies. To fully understand the role that quasispecies play in viral evolution, characterizing the trajectories of viral genotypes in an evolving population is the key. In particular, long-range haplotype information for thousands of individual viruses is critical; yet generating this information is non-trivial. Popular deep sequencing methods generate relatively short reads that do not preserve linkage information, while third generation sequencing methods have higher error rates that make detection of low frequency mutations a bioinformatics challenge. Here we applied BAsE-Seq, an Illumina-based single-virion sequencing technology, to eight samples from four chronic hepatitis B (CHB) patients - once before antiviral treatment and once after viral rebound due to resistance. RESULTS: With single-virion sequencing, we obtained 248-8796 single-virion sequences per sample, which allowed us to find evidence for both hard and soft selective sweeps. We were able to reconstruct population demographic history that was independently verified by clinically collected data. We further verified four of the samples independently through PacBio SMRT and Illumina Pooled deep sequencing. CONCLUSIONS: Overall, we showed that single-virion sequencing yields insight into viral evolution and population dynamics in an efficient and high throughput manner. We believe that single-virion sequencing is widely applicable to the study of viral evolution in the context of drug resistance and host adaptation, allows differentiation between soft or hard selective sweeps, and may be useful in the reconstruction of intra-host viral population demographic history
Directed evolution and predictive modelling of galactose oxidase towards bulky benzylic and unactivated secondary alcohols
Please click Additional Files below to see the full abstract
Notes on Amanita section Validae in Hainan Island, China
Hainan is the second largest island in China with the most extensive and well-preserved tropical forests and is also the largest island of the Indo Burma Biodiversity Hotspot. It provides in situ conservation for the unique ecosystem of the island. Recent studies have shown that there are diverse fungal species in Hainan. In this study, about 40 collections of the genus Amanita have been studied based on the morphology and molecular systematics, including 35 Chinese specimens (24 from Hainan, and eleven from other regions) and three specimens from other countries (Singapore and Malaysia). In total, five new species belonging to Amanita section Validae are described: A. cacaina, A. parvigrisea, A. pseudofritillaria, A. pseudosculpta, and A. yangii. Amanita parvifritillaria is recorded for the first time in Hainan. It is also the first report of this fungus occurring, outside Yunnan Province, China. Among the five new species, two are unique in this section because of the appendiculate pileus margin and the absence of an annulus. Based on these new findings, the diagnosis of the section Validae should be slightly modified to include a few species with appendiculate margin and the lack of annulus
Weak decays of : the non-leptonic case
In our previous study, we calculated the transition from factors of
using the QCD sum rules. Based on the factorization
approximation, the obtained form factors can be applied to evaluate the weak
non-leptonic decay rates of , where stands for a
light pseudoscalar or vector meson. We predict that the branching ratio for
inclusive non-leptonic two-body weak decays of which are realized via
the spectator mechanism, can be as large as , in
particular, the branching ratio of can reach
. Such values will be marginally accessed by the ability of
BESIII which will begin running very soon.Comment: 16 pages, revTex4, 1 figur
Bioenergetic status modulates motor neuron vulnerability and pathogenesis in a zebrafish model of spinal muscular atrophy
Degeneration and loss of lower motor neurons is the major pathological hallmark of spinal muscular atrophy (SMA), resulting from low levels of ubiquitously-expressed survival motor neuron (SMN) protein. One remarkable, yet unresolved, feature of SMA is that not all motor neurons are equally affected, with some populations displaying a robust resistance to the disease. Here, we demonstrate that selective vulnerability of distinct motor neuron pools arises from fundamental modifications to their basal molecular profiles. Comparative gene expression profiling of motor neurons innervating the extensor digitorum longus (disease-resistant), gastrocnemius (intermediate vulnerability), and tibialis anterior (vulnerable) muscles in mice revealed that disease susceptibility correlates strongly with a modified bioenergetic profile. Targeting of identified bioenergetic pathways by enhancing mitochondrial biogenesis rescued motor axon defects in SMA zebrafish. Moreover, targeting of a single bioenergetic protein, phosphoglycerate kinase 1 (Pgk1), was found to modulate motor neuron vulnerability in vivo. Knockdown of pgk1 alone was sufficient to partially mimic the SMA phenotype in wild-type zebrafish. Conversely, Pgk1 overexpression, or treatment with terazosin (an FDA-approved small molecule that binds and activates Pgk1), rescued motor axon phenotypes in SMA zebrafish. We conclude that global bioenergetics pathways can be therapeutically manipulated to ameliorate SMA motor neuron phenotypes in vivo
- …