8,014 research outputs found
Double-stranded break can be repaired by single-stranded oligonucleotides via the ATM/ATR pathway in mammalian cells
Single-stranded oligonucleotide (SSO)-mediated gene modification is a newly developed tool for site-specific gene repair in mammalian cells; however, the corrected cells always show G2/M arrest and cannot divide to form colonies. This phenomenon and the unclear mechanism seriously challenge the future application of this technique. In this study, we developed an efficient SSO-mediated DNA repair system based on double-stranded break (DSB) induction. We generated a mutant EGFP gene with insertions of 24 bp to 1.6 kb in length as a reporter integrated in mammalian cell lines. SSOs were successfully used to delete the insertion fragments upon DSB induction at a site near the insertion. We demonstrated that this process is dependent on the ATM/ATR pathway. Importantly, repaired cell clones were viable. Effects of deletion length, SSO length, strand bias, and SSO modification on gene repair frequency were also investigated. © 2008 Mary Ann Liebert, Inc.published_or_final_versio
Balanced geological section for extensional tectonic basin and its implication: An example from southern Songliao Basin
挤压构造的平衡地质剖面分析已经广泛应用于造山带构造分析, 但伸展构造区的平衡地质剖面分析实例仍然很少. 运用盆地分析的技术与方法, 分层序或阶段将地质构造依次恢复、地层逐层回剥, 并通过在松辽盆地南部吉林两井油田扶余油层4 条剖面的实践, 复原出不同时代盆地构造与地层发育的连续剖面, 揭示出松辽盆地南部主要构造样式是以浅表构造层次的负花状构造及深层剥离断层发育为特征; 断层生长指数、盆地的伸展史和伸展量等参数显示, 晚白垩世是构造转型的重要阶段, 此前主要为走滑构造样式形成阶段, 此后则主要为伸展滑脱构造发育阶段. 在此基础上, 提出松辽盆地具有伸展- 走滑双重力学构造性质, 可能是一个弧后构造盆地.The balanced geological sect ion has been widely used for the analysis of orogenic belt, but it is infrequent for ex tensional basins. In this paper, 4 extensional balanced geological sect ion analysis were practiced in Fuyu oil layer of Liangjing , Jilin oilfield, southern Songliao basin with the technology and method, including deformation history restoration, decompaction and erosion restoration. The structure of different ages and the continuous sedimentary sections have been restored. T he result s show that the structural styles possess the characteristics of negative flower structure in the shallow level and ex tensional detachment in deep level. The parameters, including fault growth index, the basin ex tensional history and fault detachment depth, indicate that Late Cretaceous is an important stage for the structure transferring mainly with a strike-slip style before this time and an ex tensional structure and detachment after this time. Therefore, a basin model with twin dynamic property and back-arc characters is proposed.published_or_final_versio
Longevity of the Permian Emeishan mantle plume (SW China): 1 Ma, 8 Ma or 18 Ma?
After the formation of the ∼ 260 Ma Emeishan large igneous province, there were two volumetrically minor magmatic pulses at ∼ 252 Ma and ∼ 242 Ma, respectively. Alkaline mafic dykes intruding both 260 Ma and 252 Ma felsic plutons in the Panxi region, southwestern China, have compositions similar to the Emeishan flood basalts. One dyke is dated using the SHRIMP zircon U-Pb technique at 242 ± 2 Ma, ∼ 18 Ma younger than the start of Emeishan magmatism. The dykes have enriched light rare earth element patterns (La/YbN = 4.4-18.8) and trace element patterns similar to the Emeishan flood basalts and average ocean-island basalts. Some trace element ratios of the dykes (Zr/Nb = 3.8-8.2, La/Nb = 0.4-1.7, Ba/La = 7.5-25.6) are somewhat similar to EM1 source material, however, there are differences. Their εNd values (εNd = +2.6 and +2.7) and ISr( ISr = 0.704542 and 0.704554) ratios are indicative of a mantle source. Thus Emeishan magmatism may have lasted for almost 20 Ma after the initial eruption. However, geological evidence precludes the possibility that the post-260 Ma magmatic events were directly related to Emeishan magmatism, which began at and ended shortly after 260 Ma. The 252 Ma plutons and 242 Ma dykes represent volumetrically minor melting of the fossil Emeishan plume-head beneath the Yangtze crust. The 252 Ma magmatic event was likely caused by post-flood basalt extension of the Yangtze crust, whereas the 242 Ma event was caused by decompressional melting associated with the collision between the South China and North China blocks during the Middle Triassic. © 2008 Cambridge University Press.published_or_final_versio
Privacy-Preserving Outsourcing of Large-Scale Nonlinear Programming to the Cloud
The increasing massive data generated by various sources has given birth to
big data analytics. Solving large-scale nonlinear programming problems (NLPs)
is one important big data analytics task that has applications in many domains
such as transport and logistics. However, NLPs are usually too computationally
expensive for resource-constrained users. Fortunately, cloud computing provides
an alternative and economical service for resource-constrained users to
outsource their computation tasks to the cloud. However, one major concern with
outsourcing NLPs is the leakage of user's private information contained in NLP
formulations and results. Although much work has been done on
privacy-preserving outsourcing of computation tasks, little attention has been
paid to NLPs. In this paper, we for the first time investigate secure
outsourcing of general large-scale NLPs with nonlinear constraints. A secure
and efficient transformation scheme at the user side is proposed to protect
user's private information; at the cloud side, generalized reduced gradient
method is applied to effectively solve the transformed large-scale NLPs. The
proposed protocol is implemented on a cloud computing testbed. Experimental
evaluations demonstrate that significant time can be saved for users and the
proposed mechanism has the potential for practical use.Comment: Ang Li and Wei Du equally contributed to this work. This work was
done when Wei Du was at the University of Arkansas. 2018 EAI International
Conference on Security and Privacy in Communication Networks (SecureComm
p63 is a key regulator of iRHOM2 signalling in the keratinocyte stress response.
Hyperproliferative keratinocytes induced by trauma, hyperkeratosis and/or inflammation display molecular signatures similar to those of palmoplantar epidermis. Inherited gain-of-function mutations in RHBDF2 (encoding iRHOM2) are associated with a hyperproliferative palmoplantar keratoderma and squamous oesophageal cancer syndrome (termed TOC). In contrast, genetic ablation of rhbdf2 in mice leads to a thinning of the mammalian footpad, and reduces keratinocyte hyperproliferation and migration. Here, we report that iRHOM2 is a novel target gene of p63 and that both p63 and iRHOM2 differentially regulate cellular stress-associated signalling pathways in normal and hyperproliferative keratinocytes. We demonstrate that p63-iRHOM2 regulates cell survival and response to oxidative stress via modulation of SURVIVIN and Cytoglobin, respectively. Furthermore, the antioxidant compound Sulforaphane downregulates p63-iRHOM2 expression, leading to reduced proliferation, inflammation, survival and ROS production. These findings elucidate a novel p63-associated pathway that identifies iRHOM2 modulation as a potential therapeutic target to treat hyperproliferative skin disease and neoplasia
Provenance and tectonic setting of the Neoproterozoic Yanbian Group, western Yangtze Block (SW China)
Tectonic evolution of the Yangtze Block of South China during Neoproterozoic time has been a major focus of debate and is important in the reconstruction of the Rodinian supercontinent. The Yanbian Group in the western margin of the Yangtze Block is a well-preserved Neoproterozoic volcanic-sedimentary sequence and provides a rare opportunity to examine the provenance and tectonic setting. It consists of a lower part composed of ∼1500 m thick basaltic lavas and an upper part of ∼3500 m thick flysch deposits. The flysch sequence contains typical deep marine turbidites consisting mainly of fine-grained volcaniclastic sandstones and mudstones, indicating a submarine fan depositional system. Detrital zircon dating yields ages ranging from ca. 865 Ma to 1000 Ma with two peaks at ca. 900 Ma and 920 Ma, respectively. The Yanbian Group is intruded by the ∼860 Ma Guandaoshan dioritic pluton, constraining its depositional age at ca. 870 Ma. The sandstones contain abundant feldspar and lithic fragments with minor amounts of quartz and have an average composition of Q 16F 35L 49, suggesting a proximal source and an undissected to transitional arc setting. The lithic fragments in the sandstones point to andesitic and felsic volcanic rock sources. The sandstones and mudstones have intermediate SiO 2/Al 2O 3 (typically 3-6), high Fe 2O 3 + MgO contents (5-12 wt%), and moderate to high K 2O/Na 2O ratios (generally 0.1-1 and 1-10 for sandstones and mudstones, respectively). In comparison with average upper continental crust, they show strong negative Nb-Ta anomalies, slight depletion of Zr-Hf, La and Th, but moderate enrichment of V, Cr, Ni, and Sc. These rocks show LREE enrichment (La/Yb N = 5.3-7.4) with flat HREE, and pronounced negative Eu anomalies (Eu/Eu * = 0.6-0.74) in chondrite-normalized REE patterns, similar to post-Archean shales. Geochemical data for these rocks suggest an arc setting and intermediate-felsic volcanic source, consistent with a back-arc basin scenario for the basaltic lavas in the lower Yanbian Group. Together with regional geological evidence, the turbidites of the Yanbian Group strongly support a model in which the western margin of the Yangtze Block was a major magmatic arc, active probably from ∼920 Ma to 740 Ma, a period of more than 180 million years. © 2008 Elsevier B.V. All rights reserved.postprin
Transmit Power Minimization for MIMO Systems of Exponential Average BER with Fixed Outage Probability
This document is the Accepted Manuscript version of the following article: Dian-Wu Yue, and Yichuang Sun, ‘Transmit Power Minimization for MIMO Systems of Exponential Average BER with Fixed Outage Probability’, Wireless Personal Communications, Vol. 90 (4): 1951-1970, first available online on 20 June 2016. Under embargo. Embargo end date: 20 June 2017. The final publication is available at Springer via https://link.springer.com/article/10.1007%2Fs11277-016-3432-4This paper is concerned with a wireless multiple-antenna system operating in multiple-input multiple-output (MIMO) fading channels with channel state information being known at both transmitter and receiver. By spatiotemporal subchannel selection and power control, it aims to minimize the average transmit power (ATP) of the MIMO system while achieving an exponential type of average bit error rate (BER) for each data stream. Under the constraints on each subchannel that individual outage probability and average BER are given, based on a traditional upper bound and a dynamic upper bound of Q function, two closed-form ATP expressions are derived, respectively, which can result in two different power allocation schemes. Numerical results are provided to validate the theoretical analysis, and show that the power allocation scheme with the dynamic upper bound can achieve more power savings than the one with the traditional upper bound.Peer reviewe
Heterogeneous mantle source and magma differentiation of quaternary arc-like volcanic rocks from Tengchong, SE margin of the Tibetan Plateau
The Tengchong volcanic field north of the Burma arc comprises numerous Quaternary volcanoes in the southeastern margin of the Tibetan Plateau. The volcanic rocks are grouped into four units (1-4) from the oldest to youngest. Units 1, 3 and 4 are composed of olivine trachybasalt, basaltic trachyandesite and trachyandesite, and Unit 2 consists of hornblende dacite. The rocks of Units 1, 3, and 4 form a generally alkaline suite in which the rocks plot along generally linear trends on Harker diagrams with only slight offset from unit to unit. They contain olivine phenocrysts with Fo values ranging from 65 to 85 mol% and have Cr-spinel with Cr# ranging from 23 to 35. All the rocks have chondrite-normalized REE patterns enriched in LREE and primitive mantle-normalized trace element patterns depleted in Ti, Nb and Ta, but they are rich in Th, Ti and P relative to typical arc volcanics. Despite minor crustal contamination, 87Sr/ 86Sr ratios (0.706-0.709), εNd values (-3.2 to -8.7), and εHf values (+4.8 to -6.4) indicate a highly heterogeneous mantle source. The Pb isotopic ratios of the lavas ( 206Pb/ 204Pb = 18.02-18.30) clearly show an EMI-type mantle source. The underlying mantle source was previously modified by subduction of the Neo-Tethyan oceanic and Indian continental lithosphere. The present heterogeneous mantle source is interpreted to have formed by variable additions of fluids and sediments derived from the subducted Indian Oceanic lithosphere, probably the Ninety East Ridge. Magma generation and emplacement was facilitated by transtensional NS-trending strike-slip faulting. © 2011 The Author(s).published_or_final_versionSpringer Open Choice, 28 May 201
SHRIMP zircon geochronology of the Emeishan Large Igneous Province (SW China): implications for double mass extinctions in Late Permian
Abstract in http://www.lpi.usra.edu/meetings/gold2001/pdf/3519.pd
Demon-like Algorithmic Quantum Cooling and its Realization with Quantum Optics
The simulation of low-temperature properties of many-body systems remains one
of the major challenges in theoretical and experimental quantum information
science. We present, and demonstrate experimentally, a universal cooling method
which is applicable to any physical system that can be simulated by a quantum
computer. This method allows us to distill and eliminate hot components of
quantum states, i.e., a quantum Maxwell's demon. The experimental
implementation is realized with a quantum-optical network, and the results are
in full agreement with theoretical predictions (with fidelity higher than
0.978). These results open a new path for simulating low-temperature properties
of physical and chemical systems that are intractable with classical methods.Comment: 7 pages, 5 figures, plus supplementarity material
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