108 research outputs found
An introduction to neighborhood sustainability assessment tool (NSAT) study for China from comprehensive analysis of eight Asian tools
In comparison to city-level and building-level sustainability research, neighborhood-level sustainable urban development is less studied. One of the ways of achieving sustainability at this level is the use of the Neighborhood Sustainability Assessment Tool (NSAT), which focuses on the sustainable urban development of districts, communities, and neighborhoods. NSAT is comprised of urban sustainable indicators and associated points ascribed towards achieving specific urban agendas, called headline sustainability indicators (HSIs) and themes. In China, neighborhood-level sustainability agenda has just been recently established in 2017. Hence, there is an immediate need for NSAT development of multiple cities responding to specific regions of different climate zones in China. As an example, this study utilizes the case of Ningbo City, located in east China, for such NSAT development. This paper provides a comprehensive analytical and comparison study of eight Asian NSATs to highlight compatibilities and extract specific indicators for a new NSAT development for China. The results from this comparative and analytical study, developed through a multidimensional approach of sustainable pathway model (SPM) inform a new NSAT development in a new context. This novel contribution is significant in a context where neighborhood sustainability measures are recently developed. This study serves as the starting point for future research of NSATs in China and other countries
Towards Efficient Communications in Federated Learning: A Contemporary Survey
In the traditional distributed machine learning scenario, the user's private
data is transmitted between nodes and a central server, which results in great
potential privacy risks. In order to balance the issues of data privacy and
joint training of models, federated learning (FL) is proposed as a special
distributed machine learning with a privacy protection mechanism, which can
realize multi-party collaborative computing without revealing the original
data. However, in practice, FL faces many challenging communication problems.
This review aims to clarify the relationship between these communication
problems, and focus on systematically analyzing the research progress of FL
communication work from three perspectives: communication efficiency,
communication environment, and communication resource allocation. Firstly, we
sort out the current challenges existing in the communications of FL. Secondly,
we have compiled articles related to FL communications, and then describe the
development trend of the entire field guided by the logical relationship
between them. Finally, we point out the future research directions for
communications in FL
Rapid screening mutations of first-line-drug-resistant genes in Mycobacterium tuberculosis strains by allele-specific real-time quantitative PCR
Tuberculosis (TB) is a worldwide health, economic, and social burden, especially in developing countries. Drug-resistant TB is the most serious type of this burden. Thus, it is necessary to screen drug-resistant mutations by using a simple and rapid detection method. A total of 32 pairs of allele-specific PCR (AS-PCR) primers were designed to screen mutation and/or wild-type alleles of 16 variations in four first-line drug-resistant genes (katG, rpoB, rpsL, and embB) of TB strains. A pair of primers was designed to amplify 16S rRNA gene and to verify successful amplification. Subsequently, we tested the specificity and sensitivity of these AS-PCR primers. The optimized condition of these AS-PCR primers was first confirmed. All mutations could be screened in general AS-PCR, but only 13 of 16 variations were intuitively investigated by using real-time quantitative PCR (qPCR) and AS-PCR primers. The results of specificity assay suggested that the AS-PCR primers with mutation and/or wildtype alleles could successfully amplify the corresponding allele under optimized PCR conditions. The sensitivity of nine pairs of primers was 500 copy numbers, and the other seven pairs of primers could successfully amplify correct fragments with a template comprising 103 or 104 copy numbers template. An optimized AS-qPCR was established to screen drug-resistant mutations in TB strains with high specificity and sensitivity
Negative thermal expansion in YbMn2Ge2 induced by the dual effect of magnetism and valence transition
AbstractNegative thermal expansion (NTE) is an intriguing property, which is generally triggered by a single NTE mechanism. In this work, an enhanced NTE (αv = −32.9 × 10−6 K−1, ΔT = 175 K) is achieved in YbMn2Ge2 intermetallic compound to be caused by a dual effect of magnetism and valence transition. In YbMn2Ge2, the Mn sublattice that forms the antiferromagnetic structure induces the magnetovolume effect, which contributes to the NTE below the Néel temperature (525 K). Concomitantly, the valence state of Yb increases from 2.40 to 2.82 in the temperature range of 300–700 K, which simultaneously causes the contraction of the unit cell volume due to smaller volume of Yb3+ than that of Yb2+. As a result, such combined effect gives rise to an enhanced NTE. The present study not only sheds light on the peculiar NTE mechanism of YbMn2Ge2, but also indicates the dual effect as a possible promising method to produce enhanced NTE materials
Fe-assisted epitaxial growth of 4-inch single-crystal transition-metal dichalcogenides on c-plane sapphire without miscut angle
Epitaxial growth and controllable doping of wafer-scale single-crystal
transition-metal dichalcogenides (TMDCs) are two central tasks for extending
Moore's law beyond silicon. However, despite considerable efforts, addressing
such crucial issues simultaneously under two-dimensional (2D) confinement is
yet to be realized. Here we design an ingenious epitaxial strategy to
synthesize record-breaking 4-inch single-crystal Fe-doped TMDCs monolayers on
industry-compatible c-plane sapphire without miscut angle. In-depth
characterizations and theoretical calculations reveal that the introduction of
Fe significantly decreases the formation energy of parallel steps on sapphire
surfaces and contributes to the edge-nucleation of unidirectional TMDCs domains
(>99%). The ultrahigh electron mobility (~86 cm2 V -1 s-1) and remarkable
on/off current ratio (~108) are discovered on 4-inch single-crystal Fe-MoS2
monolayers due to the ultralow contact resistance and perfect Ohmic contact
with metal electrodes. This work represents a substantial leap in terms of
bridging the synthesis and doping of wafer-scale single-crystal 2D
semiconductors without the need for substrate miscut, which should promote the
further device downscaling and extension of Moore's law.Comment: 17 pages, 5 figure
Identification and characterization of circular RNAs in mammary gland tissue from sheep at peak lactation and during the nonlactating period
Circular RNAs are a class of noncoding RNA with a widespread occurrence in eukaryote tissues, and with some having been demonstrated to have clear biological function. In sheep, little is known about the role of circular RNAs in mammary gland tissue, and therefore an RNA sequencing approach was used to compare mammary gland tissue expression of circular RNAs in 9 Small Tail Han sheep at peak lactation, and subsequently when they were not lactating. These 9 sheep had their RNA pooled for analysis into 3 libraries from peak lactation and 3 from the nonlactating period. A total of 3,278 and 1,756 circular RNAs were identified in the peak lactation and nonlactating mammary gland tissues, respectively, and the expression and identity of 9 of them was confirmed using reverse transcriptase-polymerase chain reaction analysis and DNA sequencing. The type, chromosomal location and length of the circular RNAs identified were ascertained. Forty upregulated and one downregulated circular RNAs were characterized in the mammary gland tissue at peak lactation compared with the nonlactating mammary gland tissue. Gene ontology enrichment analysis revealed that the parental genes of these differentially expressed circular RNAs were related to molecular function, binding, protein binding, ATP binding, and ion binding. Five differentially expression circular RNAs were selected for further analysis to predict their target microRNAs, and some microRNAs reportedly associated with the development of the mammary gland were found in the constructed circular RNA–microRNA network. This study reveals the expression profiles and characterization of circular RNAs at 2 key stages of mammary gland activity, thereby providing an improved understanding of the roles of circular RNAs in the mammary gland of sheep
Finishing the euchromatic sequence of the human genome
The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead
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