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Another piece of the meiosis puzzle

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Asian Journal of Andrology 2017年第1期19卷 3-4页

作者： Paul S Cooke Manjunatha k Nanjappa Department of Physiological Sciences College ofVeterinary Medicine University of Florida GainesvilleFL 32608 USA.

Meiosis, the process by which the ovary and testis produce haploid gametes from initially diploid cells, is essential for sexual reproduction in mammals. This process, initially described in the late 19th and early 20th century using model organisms such as sea urchins, worms and fruit flies, continues to attract extensive interest from reproductive biologists due to its centrality in gametogenesis.

关键词： testis produce haploid

How to make a human germ cell

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Asian Journal of Andrology 2015年第3期17卷 441-442页

作者： Paul S Cooke Manjunatha k Nanjappa Department of Physiological Sciences College ofVeterinary Medicine University of Florida GainesvilleFL 32608 USA

How the primordial germ cell （PGC） lineage, which eventually gives rise to spermatozoa in males and oocytes in females, is established in the developing mammalian embryo has been a critical topic in both developmental and reproductive biology for many years. There have been significant breakthroughs over the past two decades in establishing both the source of PGCs and the factors that regulate the specification of this lineage in mice,~ but our understanding of the factors that control PGC development in the human is rudimentary. The SRY-related HMG-box （SOX） family of transcription factors consists of 20 genes in humans and mice that are involved in the maintenance of pluripotency, male sexual development, and other processes. A recent paper in Cell has identified one member of this family, SOX17, as an essential factor for inducing the PGC lineage in ***, this protein does not appear to have a role in PGC specification in mice. This work not only introduces a new and important player to the field of germ cell specification, but also emphasizes the uniqueness of human PGC development compared to more extensively studied mouse models.

关键词： PlURIPOTENT STEM-CEllS MOUSE DIFFERENTIATION SPECIFICATION MICE FATE

Joint Tracking with the Electron Beam in Combination with a Work Piece Fixture

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稀有金属材料与工程 2011年第S4期40卷 99-101页

作者： M.Muecke k.leeb Steigerwald Strahltechnik MaisachGermany

The electron beam is an excellent welding *** years this powerful beam guarantees high performance welds in automotive,aviation and other *** to its excellent parallel seam quality this welding tool is often used for well-prepared gapless *** fixtures have to guarantee the well-defined positioning of the work ***,tolerances in the work piece or the loading mechanism can cause *** quality welds frequently do not allow those *** operators have to take care that the beam is proper positioned before *** joint tracking systems it is possible to automate those manual *** production gets more independent on adjustments by the *** cameras or electrodes for backscattered electrons for joint tracking systems need directly access to the *** many applications the fixture is in between the work piece and the measuring *** joint cannot be automatically *** the positioning of the electrodes for backscattered electrons gives a major impact to the quality of the *** becomes mandatory to integrate the joint detection into the *** usage of backscattered electrons for seam tracking requests the integration of electrodes into the *** fast beam deflection for electron beams opens a wide range of *** optical viewing improves the visualization of the work *** pool applications or surface modifications can increase the production capacity or achieve better product *** tracking can be performed offline or *** free programmable environment allows combining tasks to match the production *** will be used to illustrate individual applications.

关键词： electron beam welding seam tracking multi pool welding

平煤矿区十二矿下保护层开采底板破坏深度数值模拟研究

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能源与环保 2024年第2期46卷 241-247页

作者：韩泰然李昂吕璐娜中国平煤神马控股集团有限公司河南平顶山467099 炼焦煤资源绿色开发全国重点实验室河南平顶山467099 西安科技大学建筑与土木工程学院陕西西安710054

为了深入系统地研究复杂条件下工作面开采底板岩层破坏机理和突水条件,根据平煤矿区十二矿31040下保护层工作面的工程地质、水文地质条件及岩石物理力学测试报告,采用FlAC 3D有限差分程序,分别对不同条件下的底板扰动破坏深度及其演化... 详细信息

为了深入系统地研究复杂条件下工作面开采底板岩层破坏机理和突水条件,根据平煤矿区十二矿31040下保护层工作面的工程地质、水文地质条件及岩石物理力学测试报告,采用FlAC 3D有限差分程序,分别对不同条件下的底板扰动破坏深度及其演化规律进行了数值计算分析,得出了底板岩体扰动破坏深度计算公式,并针对十二矿31040下保护层工作面开采对底板扰动破坏深度发育形态影响进行分析研究,验证拟合公式的科学实用性,可为今后平煤矿区带压安全开采提供技术支持和指导。

关键词：平煤矿区底板破坏深度数值模拟水害防治

late Cenozoic Tectonic Deformation in the Dongsha Islands and Adjacent Sea Area

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Chinese Journal of Oceanology and limnology 2003年第4期21卷 377-388页

作者：吴时国刘展王万银郭军华 T.lüdmann H.k.Wong Institute of Oceanology Chinese Academy of Sciences Ocean University of China College of Engineering and Geodesy Changan University Institute of Biogeochemistry University of Hamburg

Dongsha Island and the adjacent sea area locate at the northern continental margin of the South China Sea (SCS), and is connected to the east by the Manila Trench. Analyses of seismic stratigraphy and gravity, magnetic and drilling wells data led to the discovery of three post fault sequences (V, VI, VII). Extensive tectonic uplift, magma activity and erosion occurred in Dongsha Island and the adjacent area, where most of the faults in the northeastern SCS were still active during Pliocene and Quaternary. Two groups of faults trending NEE and NW were developed during late Cenozoic. We conclude that three important tectonic movements, especially Dongsha movement (4.4-5.2 Ma) and liuhua movement (1.4-1.89 Ma), controlled the structural framework in the Dongsha rise; whose deformation in the east is stronger than that in the west and whose stress field variation suggests that the tectonic uplift in the study area contributed to magmato tectonic events correlated to the main collision phases between the East China and Taiwan 5-3 and 3-0 Ma ago.

关键词： late Cenozoic tectonic movement seismic stratigraphy plate collision South China Sea

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湖南浏阳沙市方言的“哒”及“哒”缀词

龙岩学院学报 2024年第1期42卷 41-47页

作者：黄晶晶吕晓玲华侨大学福建泉州362021

在湖南浏阳沙市方言中,“哒”的词性丰富,可以单独作动态助词、语气词、介词,还可以当词缀。单音节的“哒”可作介词,不过,双音节的“A哒”充当介词的情况更常见。“跍哒”一词极具特色,能够作动词、副词、介词,与浏阳客家话中的“跍”... 详细信息

在湖南浏阳沙市方言中,“哒”的词性丰富,可以单独作动态助词、语气词、介词,还可以当词缀。单音节的“哒”可作介词,不过,双音节的“A哒”充当介词的情况更常见。“跍哒”一词极具特色,能够作动词、副词、介词,与浏阳客家话中的“跍”相比,“跍哒”语义更丰富。双音节介词“A哒”与“跍哒”中的“哒”均为词缀,二者均属于“哒”缀词。此外,长沙方言也使用“哒”,与浏阳沙市方言的“哒”有相似之处。

关键词：浏阳沙市方言 “哒” “哒”缀词

Interannual and Seasonal Changes in the Ice Cover of Glacial lakes in the Snowy Mountains of Australia

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Journal of Mountain Science 2011年第5期8卷 655-663页

作者： k.GREEN National Parks and Wildlife Service Snowy Mountains Region PO Box 2228 Jindabyne NSW 2627 Australia

Seasonal ice cover is uncommon on Australian lakes. In the Snowy Mountains, there are five natural, seasonally ice-covered lakes including lake Cootapatamba, the highest lake in Australia. Blue lake is the only one of the five lakes with sufficient volume to be relatively independent of short-term changes in ambient temperature, and therefore is the lake most likely to be of use in tracking long-term regional climate change. Ice forms on Blue lake near the winter solstice and ice-breakup occurs from late September to November. Timing of breakup is related to spring temperature and, as such, mirrors the timing of general snow thaw in the mountains. The existence of historic photographs taken of the lake at about the time of ice breakup allows for the possibility of reconstructing a history of alpine climate and in 1905 ice breakup was probably as late as mid-December.

关键词： Climate change Mountain lakes Tarn

Solution to overcome the sparsity issue of annotated data in medical domain

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CAAI Transactions on Intelligence Technology 2018年第3期3卷 153-160页

作者： Appan k. Pujitha Jayanthi Sivaswamy Center for Visual Information Technology lilT Hyderabad Hyderabad India

Annotations are critical for machine learning and Good performance of CAD is critical to their adoption, which data. However, a vast amount of medical data is either developing computer aided diagnosis （CAD） algorithms. generally rely on training with a wide variety of annotated unlabeled or annotated only at the image-level. This poses a problem for exploring data driven approaches like deep learning for CAD. In this paper, we propose a novel crowdsourcing and synthetic image generation for training deep neural net-based lesion detection. The noisy nature of crowdsourced annotations is overcome by assigning a reliability factor for crowd subjects based on their performance and requiring region of interest markings from the crowd. A generative adversarial network-based solution is proposed to generate synthetic images with lesions to control the overall severity level of the disease. We demonstrate the reliability of the crowdsourced annotations and synthetic images by presenting a solution for training the deep neural network （DNN） with data drawn from a heterogeneous mixture of annotations. Experimental results obtained for hard exudate detection from retinal images show that training with refined crowdsourced data/synthetic images is effective as detection performance in terms of sensitivity improves by 25%/27% over training with just expert-markings.

关键词：机器学习神经网络发展现状智能技术

Fully kinetic, Electromagnetic Particle-in-Cell Simulations of Plasma Microturbulence

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Communications in Computational Physics 2007年第4期2卷 684-722页

作者： J.l.V.lewandowski l.E.Zakharov Plasma Physics laboratory Princeton UniversityP.O.Box 451PrincetonNJ 08543USA.

A novel numerical method,based on physical intuition,for particle-in-cell simulations of electromagnetic plasma microturbulence with fully kinetic ion and electron dynamics is *** method is based on the observation that,for lowfrequency modes of interest[ω/ω_(ci)≪1,ωis the typical mode frequency andωci is the ion cyclotron frequency]the impact of particles that have velocities larger than the resonant velocity,v^(r)∼ω/k_(||)(k_(||) is the typical parallel wavenumber)is negligibly small(this is especially true for the electrons).Therefore it is natural to analytically segregate the electron response into an adiabatic response and a nonadiabatic response and to numerically resolve only the latter:this approach is termed the splitting ***,the exact separation between adiabatic and nonadiabatic responses implies that a set of coupled,nonlinear elliptic equations has to be solved;in this paper an iterative technique based on the multigrid method is used to resolve the apparent numerical *** is shown that the splitting scheme allows for clean,noise-free simulations of electromagnetic drift waves and ion temperature gradient(ITG)*** is also shown that the advantage of noise-free kinetic simulations translates into better energy conservation properties.

关键词： Plasma micro-turbulence particle-in-cell simulation multigrid solver.