Resource discovery for distributed computing systems: A comprehensive survey

Large-scale distributed computing environments provide a vast amount of heterogeneous computing resources from different sources for resource sharing and distributed computing. Discovering appropriate resources in such environments is a challenge which involves several different subjects. In this paper, we provide an investigation on the current state of resource discovery protocols, mechanisms, and platforms for large-scale distributed environments, focusing on the design aspects. We classify all related aspects, general steps, and requirements to construct a novel resource discovery solution in three categories consisting of structures, methods, and issues. Accordingly, we review the literature, analyzing various aspects for each category

Double Hydrophilic Block Copolymer Templated Au Nanoparticles with Enhanced Catalytic Activity toward Nitroarene Reduction

We present a facile method for synthesizing water-dispersible gold nanoparticles (Au NPs) using a double hydrophilic block copolymer (DHBC), poly­(ethylene oxide)-<i>block</i>-poly­(acrylic acid) (PEO-<i>b</i>-PAA), as a template and demonstrate their application in the reduction of nitroarenes. Selective coordinative interactions between a gold precursor and the PAA block of the DHBC lead to the formation of micelles, which are subsequently transformed into Au NPs with an average diameter of 10 nm using a reducing agent. The DHBC-templated Au NPs (Au@DHBC NPs) remain stable in water for several months without any noticeable aggregation. Furthermore, Au@DHBC NPs are found to be highly effective in catalyzing the reduction of a series of nitroarenes. Remarkably, the turnover frequency in the case of 4-nitrophenol using Au@DHBP NPs reaches 800 h^–1, outperforming previously reported Au NP-based catalytic systems. We believe the enhanced catalytic activity is due to the DHBC shell around Au NPs, which templates the formation of spherical Au NPs and, more importantly, provides the confined interior for the enhanced catalytic activity in nitroarene reduction. Considering the wide potential application of DHBC as a template for the synthesis of novel metal NPs, we anticipate that the approach presented in this study will offer a new means to create a variety of water-stable catalytic nanomaterials in various fields of green chemistry

Accelerated MRI reconstructions via variational network and feature domain learning

Abstract We introduce three architecture modifications to enhance the performance of the end-to-end (E2E) variational network (VarNet) for undersampled MRI reconstructions. We first implemented the Feature VarNet, which propagates information throughout the cascades of the network in an N-channel feature-space instead of a 2-channel feature-space. Then, we add an attention layer that utilizes the spatial locations of Cartesian undersampling artifacts to further improve performance. Lastly, we combined the Feature and E2E VarNets into the Feature-Image (FI) VarNet, to facilitate cross-domain learning and boost accuracy. Reconstructions were evaluated on the fastMRI dataset using standard metrics and clinical scoring by three neuroradiologists. Feature and FI VarNets outperformed the E2E VarNet for 4 $$\times$$ × , 5 $$\times$$ × and 8 $$\times$$ × Cartesian undersampling in all studied metrics. FI VarNet secured second place in the public fastMRI leaderboard for 4 $$\times$$ × Cartesian undersampling, outperforming all open-source models in the leaderboard. Radiologists rated FI VarNet brain reconstructions with higher quality and sharpness than the E2E VarNet reconstructions. FI VarNet excelled in preserving anatomical details, including blood vessels, whereas E2E VarNet discarded or blurred them in some cases. The proposed FI VarNet enhances the reconstruction quality of undersampled MRI and could enable clinically acceptable reconstructions at higher acceleration factors than currently possible

Local Genome Topology Can Exhibit an Incompletely Rewired 3D-Folding State during Somatic Cell Reprogramming

Pluripotent genomes are folded in a topological hierarchy that reorganizes during differentiation. The extent to which chromatin architecture is reconfigured during somatic cell reprogramming is poorly understood. Here we integrate fine-resolution architecture maps with epigenetic marks and gene expression in embryonic stem cells (ESCs), neural progenitor cells (NPCs), and NPC-derived induced pluripotent stem cells (iPSCs). We find that most pluripotency genes reconnect to target enhancers during reprogramming. Unexpectedly, some NPC interactions around pluripotency genes persist in our iPSC clone. Pluripotency genes engaged in both fully-reprogrammed and persistent-NPC interactions exhibit over/undershooting of target expression levels in iPSCs. Additionally, we identify a subset of poorly reprogrammed interactions that do not reconnect in iPSCs and display only partially recovered, ESC-specific CTCF occupancy. 2i/LIF can abrogate persistent-NPC interactions, recover poorly reprogrammed interactions, reinstate CTCF occupancy, and restore expression levels. Our results demonstrate that iPSC genomes can exhibit imperfectly rewired 3D-folding linked to inaccurately reprogrammed gene expression

Third and fifth harmonic responses in viscous liquids

International audienceWe review the works devoted to third and fifth harmonic susceptibilities in glasses, namely χ (3) 3 and χ (5) 5. We explain why these nonlinear responses are especially well adapted to test whether or not some amorphous correlations develop upon cooling. We show that the experimental frequency and temperature dependences of χ (3) 3 and of χ (5) 5 have anomalous features, since their behavior is qualitatively different to that of an ideal gas, which is the high-temperature limit of a fluid. Most of the works have interpreted this anomalous behavior as reflecting the growth, upon cooling, of amorphously ordered domains, as predicted by the general framework of Bouchaud and Biroli (BB). We explain why most—if not all—of the challenging interpretations can be recast in a way which is consistent with that of Bouchaud and Biroli. Finally, the comparison of the anomalous features of χ (5) 5 and of χ (3) 3 shows that the amorphously ordered domains are compact, i.e., the fractal dimension d f is close to the dimension d of space. This suggests that the glass transition of molecular liquids corresponds to a new universality class of critical phenomena

A dominant-negative effect drives selection of TP53 missense mutations in myeloid malignancies

TP53, which encodes the tumor suppressor p53, is the most frequently mutated gene in human cancer. The selective pressures shaping its mutational spectrum, dominated by missense mutations, are enigmatic, and neomorphic gain-of-function (GOF) activities have been implicated. We used CRISPR-Cas9 to generate isogenic human leukemia cell lines of the most common TP53 missense mutations. Functional, DNA-binding, and transcriptional analyses revealed loss of function but no GOF effects. Comprehensive mutational scanning of p53 single-amino acid variants demonstrated that missense variants in the DNA-binding domain exert a dominant-negative effect (DNE). In mice, the DNE of p53 missense variants confers a selective advantage to hematopoietic cells on DNA damage. Analysis of clinical outcomes in patients with acute myeloid leukemia showed no evidence of GOF for TP53 missense mutations. Thus, a DNE is the primary unit of selection for TP53 missense mutations in myeloid malignancies

Double hydrophilic block copolymer templated Au nanoparticles with enhanced catalytic activity toward nitroarene reduction

We present a facile method for synthesizing water-dispersible gold nanoparticles (Au NPs) using a double hydrophilic block copolymer (DHBC), poly(ethylene oxide)-block-poly(acrylic acid) (PEO-b-PAA), as a template and demonstrate their application in the reduction of nitroarenes. Selective coordinative interactions between a gold precursor and the PAA block of the DHBC lead to the formation of micelles, which are subsequently transformed into Au NPs with an average diameter of 10 nm using a reducing agent. The DHBC-templated Au NPs (Au@DHBC NPs) remain stable in water for several months without any noticeable aggregation. Furthermore, Au@DHBC NPs are found to be highly effective in catalyzing the reduction of a series of nitroarenes. Remarkably, the turnover frequency in the case of 4-nitrophenol using Au@DHBP NPs reaches 800 h-1, outperforming previously reported Au NP-based catalytic systems. We believe the enhanced catalytic activity is due to the DHBC shell around Au NPs, which templates the formation of spherical Au NPs and, more importantly, provides the confined interior for the enhanced catalytic activity in nitroarene reduction. Considering the wide potential application of DHBC as a template for the synthesis of novel metal NPs, we anticipate that the approach presented in this study will offer a new means to create a variety of water-stable catalytic nanomaterials in various fields of green chemistry.close9