2,346 research outputs found

    Predominant occurrence of apical cell divisions in Oedogoniam pakistanense and its phylogenetic significance

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    A rare terrestrial species, Oedogonium pakistanense, was first recorded from Hubei Province, south-central China. Morphological characters. including the predominant occurrence of apical cell division and unique lateral apical caps, are described. The growth of the filaments in O. pakistanense from China is usually the result of the repeated divisions of the apical cells and intercalary divisions are rare. It is suggested that this species may represent an evolutionary transition between Oedogonium and Oedocladium, the latter being a terrestrial genus with branched filaments and cell division more often terminal than intercalary.A rare terrestrial species, Oedogonium pakistanense, was first recorded from Hubei Province, south-central China. Morphological characters. including the predominant occurrence of apical cell division and unique lateral apical caps, are described. The growth of the filaments in O. pakistanense from China is usually the result of the repeated divisions of the apical cells and intercalary divisions are rare. It is suggested that this species may represent an evolutionary transition between Oedogonium and Oedocladium, the latter being a terrestrial genus with branched filaments and cell division more often terminal than intercalary

    Male germ cell-specific protein Trs4 binds to multiple proteins

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    Temperature-related sequence 4 (Trs4) has been identified as a testis-specific gene with expression sensitive to the abdominal temperature changes induced by artificial cryptorchidism. In murine testes, Trs4 mRNA was detected in round spermatids and its protein was localized mainly in the elongating spermatids as well as in the acrosomes and tails of mature spermatozoa. Using a yeast two-hybrid screening system, we identified Rshl-2, Gstmu1, and Ddc8 as putative binding partners of the Trs4 protein in mouse testes. Their interactions were confirmed by in vivo and in vitro binding assays. Further studies demonstrated that Ddc8, a newly identified gene with unknown functions, displayed a similar expression pattern with Trs4 in mouse testes. In particular, Trs4, Ddc8, and Rshl-2 proteins were co-localized to the tails of mature spermatozoa. These results suggested that Trs4 might be involved in diverse processes of spermiogenesis and/or fertilization through interactions with its multiple binding partners. © 2009 Elsevier Inc.postprin

    Design and Testing of Cesium Atomic Concentration Detection System Based on TDLAS

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    In order to better build the Neutral Beam Injector with Negative Ion Source (NNBI), the pre-research on key technologies has been carried out for the Comprehensive Research Facility for Fusion Technology (CRAFT). Cesium seeding into negative-ion sources is a prerequisite to obtain the required negative hydrogen ion. The performance of ion source largely depends on the cesium conditions in the source. It is very necessary to quantitatively measure the amount of cesium in the source during the plasma on and off periods (vacuum stage). This article uses the absorption peak of cesium atoms near 852.1nm to build a cesium atom concentration detection system based on Tunable Diode Laser Absorption Spectroscopy (TDLAS) technology. The test experiment based on the cesium cell is carried out, obtained the variation curve of cesium concentration at different temperatures. The experimental results indicate that: the system detection range is within 5*10E6-2.5*10E7 pieces/cm3 and the system resolution better than 1*10E6 pieces/cm3.Comment: 8 pages,7 figures, the 20th International Symposium on Laser-Aided Plasma Diagnostic

    A review of physical supply and EROI of fossil fuels in China

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    This paper reviews China’s future fossil fuel supply from the perspectives of physical output and net energy output. Comprehensive analyses of physical output of fossil fuels suggest that China’s total oil production will likely reach its peak, at about 230 Mt/year (or 9.6 EJ/year), in 2018; its total gas production will peak at around 350 Bcm/year (or 13.6 EJ/year) in 2040, while coal production will peak at about 4400 Mt/year (or 91.9 EJ/year) around 2020 or so. In terms of the forecast production of these fuels, there are significant differences among current studies. These differences can be mainly explained by different ultimately recoverable resources assumptions, the nature of the models used, and differences in the historical production data. Due to the future constraints on fossil fuels production, a large gap is projected to grow between domestic supply and demand, which will need to be met by increasing imports. Net energy analyses show that both coal and oil and gas production show a steady declining trend of EROI (energy return on investment) due to the depletion of shallow-buried coal resources and conventional oil and gas resources, which is generally consistent with the approaching peaks of physical production of fossil fuels. The peaks of fossil fuels production, coupled with the decline in EROI ratios, are likely to challenge the sustainable development of Chinese society unless new abundant energy resources with high EROI values can be found

    SUMO-2 promotes mRNA translation by enhancing interaction between eIF4E and eIF4G

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    Small ubiquitin-like modifier (SUMO) proteins regulate many important eukaryotic cellular processes through reversible covalent conjugation to target proteins. In addition to its many well-known biological consequences, like subcellular translocation of protein, subnuclear structure formation, and modulation of transcriptional activity, we show here that SUMO-2 also plays a role in mRNA translation. SUMO-2 promoted formation of the active eukaryotic initiation factor 4F (eIF4F) complex by enhancing interaction between Eukaryotic Initiation Factor 4E (eIF4E) and Eukaryotic Initiation Factor 4G (eIF4G), and induced translation of a subset of proteins, such as cyclinD1 and c-myc, which essential for cell proliferation and apoptosis. As expected, overexpression of SUMO-2 can partially cancel out the disrupting effect of 4EGI-1, a small molecule inhibitor of eIF4E/eIF4G interaction, on formation of the eIF4F complex, translation of the cap-dependent protein, cell proliferation and apoptosis. On the other hand, SUMO-2 knockdown via shRNA partially impaired cap-dependent translation and cell proliferation and promoted apoptosis. These results collectively suggest that SUMO-2 conjugation plays a crucial regulatory role in protein synthesis. Thus, this report might contribute to the basic understanding of mammalian protein translation and sheds some new light on the role of SUMO in this process. © 2014 Chen et al

    Ferret badger rabies origin and its revisited importance as potential source of rabies transmission in Southeast China

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    <p>Abstract</p> <p>Background</p> <p>The frequent occurrence of ferret badger-associated human rabies cases in southeast China highlights the lack of laboratory-based surveillance and urges revisiting the potential importance of this animal in rabies transmission. To determine if the ferret badgers actually contribute to human and dog rabies cases, and the possible origin of the ferret badger-associated rabies in the region, an active rabies survey was conducted to determine the frequency of rabies infection and seroprevalence in dogs and ferret badgers.</p> <p>Methods</p> <p>A retrospective survey on rabies epidemics was performed in Zhejiang, Jiangxi and Anhui provinces in southeast China. The brain tissues from ferret badgers and dogs were assayed by fluorescent antibody test. Rabies virus was isolated and sequenced for phylogenetic analysis. The sera from ferret badgers and dogs were titrated using rabies virus neutralizing antibodies (VNA) test.</p> <p>Results</p> <p>The ferret badgers presented a higher percentage of rabies seroconversion than dogs did in the endemic region, reaching a maximum of 95% in the collected samples. Nine ferret badger-associated rabies viruses were isolated, sequenced, and were phylogenetically clustered as a separate group. Nucleotide sequence revealed 99.4-99.8% homology within the ferret badger isolates, and 83-89% homology to the dog isolates in the nucleoprotein and glycoprotein genes in the same rabies endemic regions.</p> <p>Conclusions</p> <p>Our data suggest ferret badger-associated rabies has likely formed as an independent enzootic originating from dogs during the long-term rabies infestation in southeast China. The eventual role of FB rabies in public health remains unclear. However, management of ferret badger bites, rabies awareness and control in the related regions should be an immediate need.</p

    Neurobiological mechanisms of TENS-induced analgesia

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    Pain inhibition by additional somatosensory input is the rationale for the widespread use of Transcutaneous Electrical Nerve Stimulation (TENS) to relieve pain. Two main types of TENS produce analgesia in animal models: high-frequency (~50–100 Hz) and low-intensity ‘conventional’ TENS, and low-frequency (~2–4 Hz) and highintensity ‘acupuncture-like’ TENS. However, TENS efficacy in human participants is debated, raising the question of whether the analgesic mechanisms identified in animal models are valid in humans. Here, we used a shamcontrolled experimental design to clarify the efficacy and the neurobiological effects of ‘conventional’ and ‘acupuncture-like’ TENS in 80 human volunteers. To test the analgesic effect of TENS we recorded the perceptual and brain responses elicited by radiant heat laser pulses that activate selectively Aδ and C cutaneous nociceptors. To test whether TENS has a long-lasting effect on brain state we recorded spontaneous electrocortical oscillations. The analgesic effect of ‘conventional’ TENS was maximal when nociceptive stimuli were delivered homotopically, to the same hand that received the TENS. In contrast, ‘acupuncture-like’ TENS produced a spatially-diffuse analgesic effect, coupled with long-lasting changes both in the state of the primary sensorimotor cortex (S1/ M1) and in the functional connectivity between S1/M1 and the medial prefrontal cortex, a core region in the descending pain inhibitory system. These results demonstrate that ‘conventional’ and ‘acupuncture-like’ TENS have different analgesic effects, which are mediated by different neurobiological mechanisms

    Evidence for a flux transfer event generated by multiple X-line reconnection at the magnetopause

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    Magnetic flux transfer events (FTEs) are signatures of unsteady magnetic reconnection, often observed at planetary magnetopauses. Their generation mechanism, a key ingredient determining how they regulate the transfer of solar wind energy into magnetospheres, is still largely unknown. We report THEMIS spacecraft observations on 2007-06-14 of an FTE generated by multiple X-line reconnection at the dayside magnetopause. The evidence consists of (1) two oppositely-directed ion jets converging toward the FTE that was slowly moving southward, (2) the cross-section of the FTE core being elongated along the magnetopause normal, probably squeezed by the oppositely-directed jets, and (3) bidirectional field-aligned fluxes of energetic electrons in the magnetosheath, indicating reconnection on both sides of the FTE. The observations agree well with a global magnetohydrodynamic model of the FTE generation under large geomagnetic dipole tilt, which implies the efficiency of magnetic flux transport into the magnetotail being lower for larger dipole tilt

    Changing planar thin film growth into self-assembled island formation by adjusting experimental conditions

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    Illustrated in this paper are two examples of altering planar growth into self-assembled island formation by adapting experimental conditions. Partial oxidation, undersaturated solution and high temperature change Frank-Van der Merwe (FM) growth of Al0.3Ga0.7As in liquid phase epitaxy (LPE) into isolated island deposition. Low growth speed, high temperature and in situ annealing in molecular beam epitaxy (MBE) cause the origination of InAs/GaAs quantum dots (QDs) to happen while the film is still below critical thickness in Stranski-Krastanow (SK) mode. Sample morphologies are characterized by scanning electron microscopy (SEM) or atomic force microscopy (AFM). It is suggested that such achievements are of value not only to fundamental researches but also to spheres of device applications as well. (c) 2004 Elsevier B.V. All rights reserved
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