2,932 research outputs found
The Role of Weight on Community Structure of Networks
The role of weight on the weighted networks is investigated by studying the
effect of weight on community structures. We use weighted modularity to
evaluate the partitions and Weighted Extremal Optimization algorithm to detect
communities. Starting from idealized and empirical weighted networks, the
distribution or matching between weights and edges are disturbed. Using
dissimilarity function to distinguish the difference between community
structures, it is found that the redistribution of weights does strongly affect
the community structure especially in dense networks. This indicates that the
community structure in networks is a suitable property to reflect the role of
weight.Comment: 10 pages, 6 figure
Federated Pseudo Modality Generation for Incomplete Multi-Modal MRI Reconstruction
While multi-modal learning has been widely used for MRI reconstruction, it
relies on paired multi-modal data which is difficult to acquire in real
clinical scenarios. Especially in the federated setting, the common situation
is that several medical institutions only have single-modal data, termed the
modality missing issue. Therefore, it is infeasible to deploy a standard
federated learning framework in such conditions. In this paper, we propose a
novel communication-efficient federated learning framework, namely Fed-PMG, to
address the missing modality challenge in federated multi-modal MRI
reconstruction. Specifically, we utilize a pseudo modality generation mechanism
to recover the missing modality for each single-modal client by sharing the
distribution information of the amplitude spectrum in frequency space. However,
the step of sharing the original amplitude spectrum leads to heavy
communication costs. To reduce the communication cost, we introduce a
clustering scheme to project the set of amplitude spectrum into finite cluster
centroids, and share them among the clients. With such an elaborate design, our
approach can effectively complete the missing modality within an acceptable
communication cost. Extensive experiments demonstrate that our proposed method
can attain similar performance with the ideal scenario, i.e., all clients have
the full set of modalities. The source code will be released.Comment: 10 pages, 5 figures
Increased obesity rate due to economic transition and industrialisation in Asia: a systematic review
Owing to economic transition and urbanisation, nutrition problems in Asia have shifted from malnutrition to over-nutrition. As a result, the obesity rate in Asia is rising at an alarming rate. This review aims to provide an overview of the key factors and current strategies of this phenomenon in Asia from the socio-economic point of view as well as to provide insights of possible ways to overcome these issues by analysing works of literature published between 2000 and 2018. Diet-related factors such as energy intake surplus, overconsumption of processed food, fat and sugar are among the largest contributors to this epidemic. The underlying factor of the surplus of energy intake was due to socioeconomic and cultural factors such as improved purchasing power and deep-rooted cultural associations of obesity with prosperity. Efforts have been put in by governments, NGOs, and the food industry to cope with obesity. These include the implementation of dietary guidelines, organisation of public health campaigns, enforcement of nutrition labelling on food products, application of fiscal policy, and marketing ban of energy-dense nutrient-poor (EDNP) food products to children. However, these collective efforts have not been effective. Therefore, authorities should seek long term alternative ways such as food reformulation and ‘food zoning’ to create a conducive environment that encourages a healthy diet
Insights into the Ecological Roles and Evolution of Methyl-Coenzyme M Reductase-Containing Hot Spring Archaea
Several recent studies have shown the presence of genes for the key enzyme associated with archaeal methane/alkane metabolism, methyl-coenzyme M reductase (Mcr), in metagenome-assembled genomes (MAGs) divergent to existing archaeal lineages. Here, we study the mcr-containing archaeal MAGs from several hot springs, which reveal further expansion in the diversity of archaeal organisms performing methane/alkane metabolism. Significantly, an MAG basal to organisms from the phylum Thaumarchaeota that contains mcr genes, but not those for ammonia oxidation or aerobic metabolism, is identified. Together, our phylogenetic analyses and ancestral state reconstructions suggest a mostly vertical evolution of mcrABG genes among methanogens and methanotrophs, along with frequent horizontal gene transfer of mcr genes between alkanotrophs. Analysis of all mcr-containing archaeal MAGs/genomes suggests a hydrothermal origin for these microorganisms based on optimal growth temperature predictions. These results also suggest methane/alkane oxidation or methanogenesis at high temperature likely existed in a common archaeal ancestor
Rethinking Client Drift in Federated Learning: A Logit Perspective
Federated Learning (FL) enables multiple clients to collaboratively learn in
a distributed way, allowing for privacy protection. However, the real-world
non-IID data will lead to client drift which degrades the performance of FL.
Interestingly, we find that the difference in logits between the local and
global models increases as the model is continuously updated, thus seriously
deteriorating FL performance. This is mainly due to catastrophic forgetting
caused by data heterogeneity between clients. To alleviate this problem, we
propose a new algorithm, named FedCSD, a Class prototype Similarity
Distillation in a federated framework to align the local and global models.
FedCSD does not simply transfer global knowledge to local clients, as an
undertrained global model cannot provide reliable knowledge, i.e., class
similarity information, and its wrong soft labels will mislead the optimization
of local models. Concretely, FedCSD introduces a class prototype similarity
distillation to align the local logits with the refined global logits that are
weighted by the similarity between local logits and the global prototype. To
enhance the quality of global logits, FedCSD adopts an adaptive mask to filter
out the terrible soft labels of the global models, thereby preventing them to
mislead local optimization. Extensive experiments demonstrate the superiority
of our method over the state-of-the-art federated learning approaches in
various heterogeneous settings. The source code will be released.Comment: 11 pages, 7 figure
Complex Network Properties of Chinese Natural Science Basic Research
In this paper, we studied the research areas of Chinese natural science basic
research from a point view of complex network. Two research areas are
considered to be connected if they appear in one fund proposal. The explicit
network of such connections using data from 1999 to 2004 is constructed. The
analysis of the real data shows that the degree distribution of the {\bf
research areas network} (RAN) may be better fitted by the exponential
distribution. It displays small world effect in which randomly chosen pairs of
research areas are typically separated by only a short path of intermediate
research areas. The average distance of RAN decreases with time, while the
average clustering coefficient increases with time, which indicates that the
scientific study would like to be integrated together in terms of the studied
areas. The relationship between the clustering coefficient and the
degree indicates that there is no hierarchical organization in RAN.Comment: 12 pages, 8 figures, accepted by Physica
Weighted Network of Chinese Nature Science Basic Research
Using the requisition papers of Chinese Nature Science Basic Research in
management and information department, we construct the weighted network of
research areas({\bf WRAN}) represented by the subject codes. In WRAN, two
research areas are considered connected if they have been filled in at least
one requisition paper. The edge weight is defined as the number of requisition
papers which have filled in the same pairs of codes. The node strength is
defined as the number of requisition papers which have filled in this code,
including the papers which have filled in it only. Here we study a variety of
nonlocal statistics for these networks, such as typical distances between
research areas through the network, and measures of centrality such as
betweenness. These statistics characteristics can illuminate the global
development trend of Chinese scientific study, it is also helpful to adjust the
code system to reflect the real status more accurately. Finally, we present a
plausible model for the formation and structure of networks with the observed
properties.Comment: 8 pages, 14 figure
10-Hydroxy-10-(1,3-thiazol-2-ylmethyl)phenanthren-9(10H)-one
In the title phenanthrenone compound, C18H13NO2S, the dihydrophenanthrene ring system is not planar, with its central ring distorted to a screw-boat conformation. The essentially planar thiazole ring [maximum deviation = 0.005 (1) Å] is inclined at an interplanar angle of 23.36 (5)° with respect to the mean plane through the dihydrophenanthrene ring system. In the crystal packing, intermolecular O—H⋯N hydrogen bonds link the molecules into infinite chains along the a axis. Weak intermolecular C—H⋯π interactions further stabilize the crystal packing
Magnetic anisotropy reversal driven by structural symmetry-breaking in monolayer {\alpha}-RuCl3
Layered {\alpha}-RuCl3 is a promising material to potentially realize the
long-sought Kitaev quantum spin liquid with fractionalized excitations. While
evidence of this exotic state has been reported under a modest in-plane
magnetic field, such behavior is largely inconsistent with theoretical
expectations of Kitaev phases emerging only in out-of-plane fields. These
predicted field-induced states have been mostly out of reach due to the strong
easy-plane anisotropy of bulk crystals, however. We use a combination of
tunneling spectroscopy, magnetotransport, electron diffraction, and ab initio
calculations to study the layer-dependent magnons, anisotropy, structure, and
exchange coupling in atomically thin samples. Due to structural distortions,
the sign of the average off-diagonal exchange changes in monolayer
{\alpha}-RuCl3, leading to a reversal of magnetic anisotropy to easy-axis. Our
work provides a new avenue to tune the magnetic interactions in {\alpha}-RuCl3
and allows theoretically predicted quantum spin liquid phases for out-of-plane
fields to be more experimentally accessible
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