Design and Experiment of Frequency Offset Estimation and Compensation in High-speed Underwater Acoustic Communication

In underwater acoustic (UWA) communication, Doppler effect is particularly severe due to the slow velocity of sound and the complex variant UWA channel environment. Carrier frequency offset (CFO) can result in extension and compression of the received signal in time domain and has a direct effect on the performance of decoding. In this paper, we propose a new scheme of CFO estimation and compensation for a high speed UWA communication system. There are three steps including coarse CFO estimation, fine CFO estimation and linear interpolation, which are taken to estimate and compensate the CFO. The scheme can eliminate the phenomenon of ambiguous phase and tolerate quick random variation of the CFO in UWA channel. A UWA communication experiment was carried out in December 2012 in the Indian Ocean, off Rottnest Island, Western Australia. With the proposed algorithm in this paper, the UWA system can achieve an average of 1.95% uncoded BER with QPSK modulation at the 1km range and 5.57% with BPSK at the 10km range

Self-assembly of copper and cobalt complexes with hierarchical size and catalytic properties for hydroxylation of phenol

A feasible and effective self-assembly method to synthesize different scale coordination polymers in highly dilute solution (from nanocrystals to microcrystals and to bulk crystals) without any blocking agent has been described. The growth of crystalline particles was controlled by removing the particles at different reaction times to interrupt the growth at the desired size. The nano and microscale particles show better catalytic conversions and selectivities in the hydroxylation of phenols than the bulk crystals

Platyintybia, a new genus of Apalochrini (Coleoptera, Melyridae, Malachiinae) from China

A new genus of malachiine Melyridae, Platyintybia gen. nov., is described based on several male-specific characters, along with description of its type species, Platyintybia zhongshanensis sp. nov., from China. A new combination, Platyintybia sarawakensis (Champion, 1921), comb. nov., is proposed after examining the type specimen; this species is newly recorded from China. A key to the genera of Chinese Apalochrini is provided for the first time

Hematite Dodecahedron Crystals with High-index Facets Grown and Grafted on One Dimensional Structures for Efficient Photoelectrochemical H2 Generation

Fe2O3 polyhedrons are one of the most promising morphologies for photoelectrochemical water splitting. In spite of recent reports on the successful synthesis of various Fe2O3 polyhedrons, the fabrication of defined photoelectrodes by anchoring the polyhedron in a suitable configuration remains a great challenge. Herein, we introduce a synthetic strategy to prepare Fe2O3 dodecahedrons with high-index {112} facets directly anchored on a one dimensional Fe2O3 nanoflake ({110} facets) electrode. Key is that the Fe2O3 nanoflakes act as seeds for the initiation of the growth of dodecahedral nanocrystals from an iron nitrate solution. The initial single crystals consist of Fe3O4 with exposed {110} basal surfaces that then in a thermal step can be converted to hematite with {112} facets. The resulting single crystal (bi-crystal) hematite photoanode demonstrates a high efficiency for solar water splitting with an excellent photoresponse due to the synergistic effect of direct grafting of the light harvesting and reactive polyhedron and the 1D transport geometry. Under optimized conditions the hematite polyhedrons on nanoflake-structure show photocurrent densities of 2.4 mA cm-2 at 1.23 VRHE and 3.5 mA cm-2 at 1.5 VRHE under AM 1.5G simulated sunlight

Dynamics of wetlands and their effects on carbon emissions in China coastal region - Case study in Bohai Economic Rim

Wetlands are one of the largest carbon sinks in the world due to their large carbon storage, potential for carbon sequestration in peat formation, sediment deposition and plant biomass. However, rapid economic development is causing changes to wetland carbon storage. China has participated in the implementation of the Kyoto Protocol and is decreasing its carbon emissions. Analyzing the carbon changes that are caused by wetland dynamics may provide some insights regarding decreasing carbon emissions. Therefore, wetland data from 1985, 1995 and 2005 were extracted from remote sensing images. Using spatial analysis and statistics, we determined that the water body area continued to increase, whereas the swamp, floodplain and shallow areas tended to decrease during the period from 1985 to 2005. Those changes caused wetland carbon stock to decrease. The conversion of other land use categories to wetland was the primary cause of carbon stock loss. Therefore, it is more beneficial for China to decrease per capita carbon emissions by decreasing carbon emissions from the conversion of other land use categories to wetlands. (C) 2013 Elsevier Ltd. All rights reserved.Wetlands are one of the largest carbon sinks in the world due to their large carbon storage, potential for carbon sequestration in peat formation, sediment deposition and plant biomass. However, rapid economic development is causing changes to wetland carbon storage. China has participated in the implementation of the Kyoto Protocol and is decreasing its carbon emissions. Analyzing the carbon changes that are caused by wetland dynamics may provide some insights regarding decreasing carbon emissions. Therefore, wetland data from 1985, 1995 and 2005 were extracted from remote sensing images. Using spatial analysis and statistics, we determined that the water body area continued to increase, whereas the swamp, floodplain and shallow areas tended to decrease during the period from 1985 to 2005. Those changes caused wetland carbon stock to decrease. The conversion of other land use categories to wetland was the primary cause of carbon stock loss. Therefore, it is more beneficial for China to decrease per capita carbon emissions by decreasing carbon emissions from the conversion of other land use categories to wetlands. (C) 2013 Elsevier Ltd. All rights reserved

Sclerotinia sclerotiorum Thioredoxin Reductase Is Required for Oxidative Stress Tolerance, Virulence, and Sclerotial Development

Sclerotinia sclerotiorum is a destructive ascomycete plant pathogen with worldwide distribution. Extensive research on different aspects of this pathogen’s capability to cause disease will help to uncover clues about new ways to safely control Sclerotinia diseases. The thioredoxin (Trx) system consists of Trx and thioredoxin reductase (TrxR), which play critical roles in maintenance of cellular redox homeostasis. In this study, we functionally characterized a gene encoding a TrxR (SsTrr1) in S. sclerotiorum. The amino acids of SsTrr1 exhibited high similarity with reported TrxRs in plant pathogens and targeted silencing of SsTrr1 lead to a decrease in TrxR activities of mycelium. SsTrr1 showed high expression levels during hyphae growth, and the levels decreased at the different stages of sclerotial development. SsTrr1 gene-silenced strains produced a smaller number of larger sclerotia on potato dextrose agar medium. The observations were consistent with the inhibitory effects on sclerotial development by the TrxR inhibitor, anrunofin. The expression of SsTrr1 showed a dramatic increase under the oxidative stress and the hyphal growth of gene-silenced strains showed more sensitivity to H2O2. SsTrr1 gene-silenced strains also showed impaired virulence in different hosts. Taken together, our results suggest that SsTrr1 encodes a TrxR that is of great important for oxidative stress tolerance, virulence, and sclerotial development of S. sclerotiorum

Direct Conversion of Fibroblasts to Neurons by Reprogramming PTB-Regulated MicroRNA Circuits

SummaryThe induction of pluripotency or trans-differentiation of one cell type to another can be accomplished with cell-lineage-specific transcription factors. Here, we report that repression of a single RNA binding polypyrimidine-tract-binding (PTB) protein, which occurs during normal brain development via the action of miR-124, is sufficient to induce trans-differentiation of fibroblasts into functional neurons. Besides its traditional role in regulated splicing, we show that PTB has a previously undocumented function in the regulation of microRNA functions, suppressing or enhancing microRNA targeting by competitive binding on target mRNA or altering local RNA secondary structure. A key event during neuronal induction is the relief of PTB-mediated blockage of microRNA action on multiple components of the REST complex, thereby derepressing a large array of neuronal genes, including miR-124 and multiple neuronal-specific transcription factors, in nonneuronal cells. This converts a negative feedback loop to a positive one to elicit cellular reprogramming to the neuronal lineage

MiR-574-5p Activates Human TLR8 to Promote Autoimmune Signaling and Lupus

Endosomal single-stranded RNA-sensing Toll-like receptor-7/8 (TLR7/8) plays a pivotal role in inflammation and immune responses and autoimmune diseases. However, the mechanisms underlying the initiation of the TLR7/8-mediated autoimmune signaling remain to be fully elucidated. Here, we demonstrate that miR-574-5p is aberrantly upregulated in tissues of lupus prone mice and in the plasma of lupus patients, with its expression levels correlating with the disease activity. miR-574-5p binds to and activates human hTLR8 or its murine ortholog mTlr7 to elicit a series of MyD88-dependent immune and inflammatory responses. These responses include the overproduction of cytokines and interferons, the activation of STAT1 signaling and B lymphocytes, and the production of autoantigens. In a transgenic mouse model, the induction of miR-574-5p overexpression is associated with increased secretion of antinuclear and anti-dsDNA antibodies, increased IgG and C3 deposit in the kidney, elevated expression of inflammatory genes in the spleen. In lupus-prone mice, lentivirus-mediated silencing of miR-574-5p significantly ameliorates major symptoms associated with lupus and lupus nephritis. Collectively, these results suggest that the miR-574-5p-hTLR8/mTlr7 signaling is an important axis of immune and inflammatory responses, contributing significantly to the development of lupus and lupus nephritis