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Calabi-Yau Topology of Primordial Fermions
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作者 Edwin Eugene Klingman 《Journal of Modern Physics》 2024年第1期132-158,共27页
Quantum field theory creates fermions via abstract operators exciting abstract fields, with a specific field for each type of specific particle. This operator algebra lends itself well to quantum statistics, neverthel... Quantum field theory creates fermions via abstract operators exciting abstract fields, with a specific field for each type of specific particle. This operator algebra lends itself well to quantum statistics, nevertheless, our physical understanding of this process is nonintuitive at best. In this paper we analyze the creation of fermions from primordial gauge field quantum gravity loops in the context of Calabi-Yau manifold theory. I extend a prior mass-gap treatment based on Yang-Mills gauge theory of higher order self-interaction to include the half-integral spin of fermions. 展开更多
关键词 Calabi-Yau Topology Fermion Spin Particle Genesis primordial Field Self-Interaction Equations Yang-Mills Gravity
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Primordial germ cell-mediated transgenesis and genome editing in birds 被引量:2
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作者 Jae Yong Han Young Hyun Park 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2018年第2期257-267,共11页
Transgenesis and genome editing in birds are based on a unique germline transmission system using primordial germ cells(PGCs), which is quite different from the mammalian transgenic and genome editing system. PGCs are... Transgenesis and genome editing in birds are based on a unique germline transmission system using primordial germ cells(PGCs), which is quite different from the mammalian transgenic and genome editing system. PGCs are progenitor cells of gametes that can deliver genetic information to the next generation. Since avian PGCs were first discovered in nineteenth century, there have been numerous efforts to reveal their origin, specification, and unique migration pattern, and to improve germline transmission efficiency. Recent advances in the isolation and in vitro culture of avian PGCs with genetic manipulation and genome editing tools enable the development of valuable avian models that were unavailable before. However, many challenges remain in the production of transgenic and genome-edited birds,including the precise control of germline transmission, introduction of exogenous genes, and genome editing in PGCs.Therefore, establishing reliable germline-competent PGCs and applying precise genome editing systems are critical current issues in the production of avian models. Here, we introduce a historical overview of avian PGCs and their application, including improved techniques and methodologies in the production of transgenic and genome-edited birds, and we discuss the future potential applications of transgenic and genome-edited birds to provide opportunities and benefits for humans. 展开更多
关键词 AVIAN GENOME EDITING primordial GERM cell TRANSGENESIS
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Effects of 17beta-estradiol on cell migration in male chicks distribution of primordial germ 被引量:1
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作者 Xiu-Mei Jin Yi-Xiang Zhang Zan-Dong Li 《Asian Journal of Andrology》 SCIE CAS CSCD 2008年第2期243-248,共6页
Aim: To assess whether exogenous estradiol has any effect on migration of primordial germ cells (PGCs) in the chick. Methods: Fertilized eggs were treated with 17beta-estradiol (E2) (80 lag/egg) at stage X (d... Aim: To assess whether exogenous estradiol has any effect on migration of primordial germ cells (PGCs) in the chick. Methods: Fertilized eggs were treated with 17beta-estradiol (E2) (80 lag/egg) at stage X (day 0 of incubation), stages 8-10 (incubation 30 h) and 13-15 (incubation 55 h). Controls received vehicle (emulsion) only. Changes in PGC number were measured on different days according to developmental stages. Results: In male right gonads, but not in female left gonads, at stages 28-30 (incubation 132 h) significant decreases in the mean number of PGCs aggregating were observed compared with the controls (P 〈 0.05) while the total PGC number in the right and left gonads at each stage did not change (P 〉 0.05). Conclusion: The present study provides evidence that E2 has significant effects on the localization of PGCs in male right, but not female left, gonads of chicken embryos at stages 28-30, compared with controls. (Asian J Andro12008 Mar; 10: 243-248) 展开更多
关键词 17beta-estradiol primordial germ cells male chick
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Subduction of the primordial crust into the deep mantle 被引量:3
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作者 Hiroki Ichikawa Steeve Gréaux Shintaro Azum 《Geoscience Frontiers》 SCIE CAS CSCD 2017年第2期347-354,共8页
The primordial crust on the Earth formed from the crystallization of the surface magma ocean during the Hadean.However,geological surveys have found no evidence of rocks dating back to more than 4 Ga on the Earth's s... The primordial crust on the Earth formed from the crystallization of the surface magma ocean during the Hadean.However,geological surveys have found no evidence of rocks dating back to more than 4 Ga on the Earth's surface,suggesting the Hadean crust was lost due to some processes.We investigated the subduction of one of the possible candidates for the primordial crust,anorthosite and KREEP crust similar to the Moon,which is also considered to have formed from the crystallization of the magma ocean.Similar to the present Earth,the subduction of primordial crust by subduction erosion is expected to be an effective way of eliminating primordial crust from the surface.In this study,the subduction rate of the primordial crust via subduction channels is evaluated by numerical simulations.The subduction channels are located between the subducting slab and the mantle wedge and are comprised of primordial crust materials supplied mainly by subduction erosion.We have found that primordial anorthosite and KREEP crust of up to - 50 km thick at the Earth's surface was able to be conveyed to the deep mantle within 0.1-2 Gy by that mechanism. 展开更多
关键词 primordial crust Anorthosite KREEP Subduction erosion Subduction channel
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Targeting lentiviral vectors to primordial germ cells(PGCs):An efficient strategy for generating transgenic chickens 被引量:5
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作者 Zi-Qin Jiang Han-Yu Wu +2 位作者 Jing Tian Ning Li Xiao-Xiang Hu 《Zoological Research》 SCIE CAS CSCD 2020年第3期281-291,共11页
Recent advances in avian transgenic studies highlight the possibility of utilizing lentiviral vectors as tools to generate transgenic chickens. However, low rates of gonadal chimerism and germ line transmission effici... Recent advances in avian transgenic studies highlight the possibility of utilizing lentiviral vectors as tools to generate transgenic chickens. However, low rates of gonadal chimerism and germ line transmission efficiency still limit the broad usage of this method in creating transgenic chickens. In this study, we implemented a simple strategy using modified lentiviral vectors targeted to chicken primordial germ cells(PGCs) to generate transgenic chickens. The lentiviral vectors were pseudotyped with a modified Sindbis virus envelope protein(termed M168) and conjugated with an antibody specific to PGC membrane proteins. We demonstrated that these optimized M168-pseudotyped lentiviral vectors conjugated with SSEA4 antibodies successfully targeted transduction of PGCs in vitro and in vivo. Compared with the control, 50.0%–66.7% of chicken embryos expressed green fluorescent protein(GFP) in gonads transduced by the M168-pseudotyped lentivirus. This improved the targeted transduction efficiency by 30.0%–46.7%. Efficient chimerism of exogenous genes was also observed. This targeting technology could improve the efficiency of germ line transmission and provide greater opportunities for transgenic poultry studies. 展开更多
关键词 M168-pseudotyped lentiviral vectors primordial germ cells Targeted transduction Transgenic chickens SSEA4
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Hadean Earth and primordial continents:The cradle of prebiotic life 被引量:2
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作者 M.Santosh T.Arai S.Maruyama 《Geoscience Frontiers》 SCIE CAS CSCD 2017年第2期309-327,共19页
The Hadean history of Earth is shrouded in mystery and it is considered that the planet was born dry with no water or atmosphere.The Earth-Moon system had many features in common during the birth stage.Solidification ... The Hadean history of Earth is shrouded in mystery and it is considered that the planet was born dry with no water or atmosphere.The Earth-Moon system had many features in common during the birth stage.Solidification of the dry magma ocean at 4.53 Ga generated primordial continents with komatiite.We speculate that the upper crust was composed of fractionated gabbros and the middle felsic crust by anorthosite at ca.21 km depth boundary,underlain by meta-anorthosite(grossular + kyanite 4 quartz)down to 50-60 km in depth.The thickness of the mafic KREEP basalt in the lower crust,separating it from the underlying upper mantle is not well-constrained and might have been up to ca.100-200 km depending on the degree of fractionation and gravitational stability versus surrounding mantle density.The primordial continents must have been composed of the final residue of dry magma ocean and enriched in several critical elements including Ca,Mg,Fe,Mn,P,K,and Cl which were exposed on the surface of the dry Earth.Around 190 million years after the solidification of the magma ocean, "ABEL bombardment" delivered volatiles including H_2O,CO_2,N_2 as well as silicate components through the addition of icy asteroids.This event continued for 200 Myr with subordinate bombardments until 3.9 Ga,preparing the Earth for the prebiotic chemical evolution and as the cradle of first life.Due to vigorous convection arising from high mantle potential temperatures,the primordial continents disintegrated and were dragged down to the deep mantle,marking the onset of Hadean plate tectonics. 展开更多
关键词 Earth-Moon system primordial continents ABEL bombardment Tectonic erosion Hadean plate tectonics
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The Primordial Principle of Self-Interaction 被引量:3
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作者 Edwin Eugene Klingman 《Journal of Modern Physics》 2021年第2期65-81,共17页
The Standard Model of Particle Physics treats four fields—the gravitational, electromagnetic, weak and strong fields. These fields are assumed to converge to a single field at the big bang, but the theory has failed ... The Standard Model of Particle Physics treats four fields—the gravitational, electromagnetic, weak and strong fields. These fields are assumed to converge to a single field at the big bang, but the theory has failed to produce this convergence. Our theory proposes<em> one </em>primordial field and analyzes the evolution of this field. The key assumption is that <em>only</em> the primordial field exists—if any change is to occur, it must be based upon self-interaction, as there is nothing other than the field itself to interact with. This can be formalized as the <em>Principle</em> <em>of </em><em>Self-interaction</em> and the consequences explored. I show that this leads to the linearized Einstein field equations and discuss the key ontological implications of the theory. 展开更多
关键词 SELF-INTERACTION Principles of Physics Electromagnetism GRAVITOMAGNETISM “Weak Field” Approximation Kasner Metric Iterated Solutions Gauge Theory of Gravity primordial Principle
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Frontiers in early Earth history and primordial life--PartⅠ 被引量:2
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作者 S.Maruyama M.Santosh 《Geoscience Frontiers》 SCIE CAS CSCD 2017年第2期211-213,共3页
The history of the early Earth is shrouded in mystery, and one of the major outcomes of the Apollo Program, lunar sampling, and the data acquired by subsequent orbiting missions, is that the Moon is an important analo... The history of the early Earth is shrouded in mystery, and one of the major outcomes of the Apollo Program, lunar sampling, and the data acquired by subsequent orbiting missions, is that the Moon is an important analogue for the Hadean Earth, which includes primordial planet-forming materials. We assemble two special issues of "Geoscience Frontiers" with state-of-the-art contributions that provide insights into planetary formation, Earth's early history and primordial life. New theories show why the Earth began as a dry planetary system and was later seeded by an ocean-atmosphere system through the bombardment of carbonaceous chondrites. A combination of the information concerning the evolution of Earth, Mars, and the other terrestrial planets is important in understanding the fate of the primordial continental crustal materials and the making of habitable planets. 展开更多
关键词 Frontiers in early Earth history and primordial life-Part
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Optical and Network Performance Analysis of XGS-PON System over Active Co-Existence PON Systems 被引量:1
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作者 D. Tarsono A. Ahmad +4 位作者 K. A. Sharif M. H. Othman K. Khairi N. A. Ngah Z. A. Manaf 《Optics and Photonics Journal》 2017年第8期40-48,共9页
We proposed an enhanced Reach Extender (RE) called Active Co-existence (ACEX) and investigate its performance with respect to XGS-PON system that co-exist with GPON and TWDM-PON system. The RE is consists of hybrid op... We proposed an enhanced Reach Extender (RE) called Active Co-existence (ACEX) and investigate its performance with respect to XGS-PON system that co-exist with GPON and TWDM-PON system. The RE is consists of hybrid optical amplifier integrated (EDFA and SOA) with Co-existence Element (CEX) module which is installed at the Central Office (CO) together with the OLT system and act as a booster and pre-amplifier for the downstream and upstream optical signal respectively. The results show that the proposed ACEX is capable to support XGS-PON operation for a maximum distance of 35 km with 128 splitting ratio and up to 44 dB link loss. 展开更多
关键词 GPON XGS-PON TWDM-PON co-existence Element ACTIVE co-existence Reach EXTENDER
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Adaptive genetic diversity of dominant species contributes to species co-existence and community assembly 被引量:1
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作者 Qiao-Ming Li Chao-Nan Cai +4 位作者 Wu-Mei Xu Min Cao Li-Qing Sha Lu-Xiang Lin Tian-Hua He 《Plant Diversity》 SCIE CAS CSCD 2022年第3期271-278,共8页
The synthesis of evolutionary biology and community ecology aims to understand how genetic variation within one species can shape community properties and how the ecological properties of a community can drive the evo... The synthesis of evolutionary biology and community ecology aims to understand how genetic variation within one species can shape community properties and how the ecological properties of a community can drive the evolution of a species.A rarely explored aspect is whether the interaction of genetic variation and community properties depends on the species'ecological role.Here we investigated the interactions among environmental factors,species diversity,and the within-species genetic diversity of species with different ecological roles.Using high-throughput DNA sequencing,we genotyped a canopydominant tree species,Parashorea chinensis,and an understory-abundant species,Pittosporopsis kerrii,from fifteen plots in Xishuangbanna tropical seasonal rainforest and estimated their adaptive,neutral and total genetic diversity;we also surveyed species diversity and assayed key soil nutrients.Structural equation modelling revealed that soil nitrogen availability created an opposing effect in species diversity and adaptive genetic diversity of the canopy-dominant Pa.chinensis.The increased adaptive genetic diversity of Pa.chinensis led to greater species diversity by promoting co-existence.Increased species diversity reduced the adaptive genetic diversity of the dominant understory species,Pi.kerrii,which was promoted by the adaptive genetic diversity of the canopy-dominant Pa.chinensis.However,such relationships were absent when neutral genetic diversity or total genetic diversity were used in the model.Our results demonstrated the important ecological interaction between adaptive genetic diversity and species diversity,but the pattern of the interaction depends on the identity of the species.Our results highlight the significant ecological role of dominant species in competitive interactions and regulation of community structure. 展开更多
关键词 Adaptive genetic diversity Community assembly Dominant species Species-genetic diversity correlation(SGDC) Species co-existence Structural equation modelling
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α-ketoglutarate promotes the specialization of primordial germ cell-like cells through regulating epigenetic reprogramming
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作者 Ming Xing Na Wang +1 位作者 Hanyi Zeng Jun Zhang 《The Journal of Biomedical Research》 CAS CSCD 2021年第1期36-46,I0014-I0016,共14页
There is growing evidence that cellular metabolism can directly participate in epigenetic dynamics and consequently modulate gene expression.However,the role of metabolites in activating the key gene regulatory networ... There is growing evidence that cellular metabolism can directly participate in epigenetic dynamics and consequently modulate gene expression.However,the role of metabolites in activating the key gene regulatory network for specialization of germ cell lineage remains largely unknown.Here,we identified some cellular metabolites with significant changes by untargeted metabolomics between mouse epiblast-like cells(EpiLCs)and primordial germ cell-like cells(PGCLCs).More importantly,we found that inhibition of glutaminolysis by bis-2-(5-phenylacetamido-1,3,4-thiadiazol-2-yl)ethyl sulfide(BPTES)impeded PGCLC specialization,but the impediment could be rescued by addition ofα-ketoglutarate(αKG),the intermediate metabolite of oxidative phosphorylation and glutaminolysis.Moreover,adding aKG alone to the PGCLC medium accelerated the PGCLC specialization through promoting H3 K27 me3 demethylation.Thus,our study reveals the importance of metabolite aKG in the germ cell fate determination and highlights the essential role of cellular metabolism in shaping the cell identities through epigenetic events. 展开更多
关键词 cellular metabolism Α-KETOGLUTARATE primordial germ cells EPIGENOME
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The Efficiency of CP-Violating <i>α</i>2-Dynamos from Primordial Cosmic Axion Oscillation with Torsion
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作者 L. C. Garcia de Andrade 《International Journal of Astronomy and Astrophysics》 2015年第1期56-59,共4页
Recently torsion fields were introduced in CP-violating cosmic axion a2-dynamos [Garcia de Andrade, Mod Phys Lett A, (2011)] in order to obtain Lorentz violating bounds for torsion. Here instead, oscillating axion sol... Recently torsion fields were introduced in CP-violating cosmic axion a2-dynamos [Garcia de Andrade, Mod Phys Lett A, (2011)] in order to obtain Lorentz violating bounds for torsion. Here instead, oscillating axion solutions of the dynamo equation with torsion modes [Garcia de Andrade, Phys Lett B (2012)] are obtained taking into account dissipative torsion fields. Magnetic helicity torsion oscillatory contribution is also obtained. Note that the torsion presence guarantees dynamo efficiency when axion dynamo length is much stronger than the torsion length. Primordial axion oscillations due to torsion yield a magnetic field of 109 G at Nucleosynthesis epoch. This is obtained due to a decay of BBN magnetic field of 1015 G induced by torsion. Since torsion is taken as 10–20 s–1, the dynamo efficiency is granted over torsion damping. Of course dynamo efficiency is better in the absence of torsion. In the particular case when the torsion is obtained from anomalies it is given by the gradient of axion scalar [Duncan et al., Nuclear Phys B 87, 215] that a simpler dynamo equation is obtained and dynamo mechanism seems to be efficient when the torsion helicity, is negative while magnetic field decays when the torsion is positive. In this case an extremely huge value for the magnetic field of 1015 Gauss is obtained. This is one order of magnitude greater than the primordial magnetic fields of the domain wall. Actually if one uses tDW ~ 10-4 s one obtains BDW ~ 1022 G which is a more stringent limit to the DW magnetic primordial field. 展开更多
关键词 TORSION Theories AXION DYNAMO primordial Magnetic Fields
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Chicken Mesenchymal Stem Cells as Feeder Cells Facilitate the Cultivation of Primordial Germ Cells from Circulating Blood and Gonadal Ridge
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作者 Dongsheng Li Zhisheng Chen +5 位作者 Shengfeng Chen Huiqin Ji Xiaoshu Zhan Dongzhang Luo Huina Luo Bingyun Wang 《Stem Cell Discovery》 2019年第1期1-14,共14页
Long-term maintenance of chicken primordial germ cells (PGCs) in vitro has tremendous potential for transgenic chicken production. Feeder cells are essential for the establishment and culture of chicken PGCs in vitro.... Long-term maintenance of chicken primordial germ cells (PGCs) in vitro has tremendous potential for transgenic chicken production. Feeder cells are essential for the establishment and culture of chicken PGCs in vitro. Buffalo rat liver (BRL) cells are the most commonly used feeder cells for PGCs culture;however, this feeder layers from other animal species usually cause immunogenic contaminations, compromising the potential of PGCs in applications. Therefore, we tested chicken source mensenchymal stem cell (MSCs) derived from bone marrow as feeder cells to further improve PGC culture conditions. MSCs derived from chicken bone marrow have a powerful capacity to proliferate and secrete cytokines. We found chicken primordial germ cells derived from circulating blood (cPGCs) and gonads (gPGCs) can be maintained and proliferated with MSCs feeder layer cells. PGCs co-cultured on MSCs feeder retained their pluripotency, expressed PGCs specific genes and stemness markers, and maintained undifferentiated state. Our study indicated that the xeno-free MSCs-feeders culture system is a good candidate for growth and expansion of PGCs as the stepping stone for transgenic chicken research. 展开更多
关键词 CHICKEN primordial GERM CELLS Mensenchymal Stem CELLS TRANSGENIC
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Formation of Galaxies in the Context of Gravitational Waves and Primordial Black Holes
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作者 Shawqi Al Dallal Walid J. Azzam 《Journal of Modern Physics》 2019年第3期214-224,共11页
The recent discovery of gravitational waves has revolutionized our understanding of many aspects regarding how the universe works. The formation of galaxies stands as one of the most challenging problems in astrophysi... The recent discovery of gravitational waves has revolutionized our understanding of many aspects regarding how the universe works. The formation of galaxies stands as one of the most challenging problems in astrophysics. Regardless of how far back we look in the early universe, we keep discovering galaxies with supermassive black holes lurking at their centers. Many models have been proposed to explain the rapid formation of supermassive black holes, including the massive accretion of material, the collapse of type III stars, and the merger of stellar mass black holes. Some of these events give rise to the production of gravitational waves that could be detected by future generations of more sensitive detectors. Alternatively, the existence of these supermassive black holes can be explained in the context of primordial black holes. In this paper we discuss the various models of galaxy formation shedding light on the role that gravitational waves can play to test of the validity of some of these models. We also discuss the prospect of primordial black holes as a seeding constituent for galaxy formation. 展开更多
关键词 GRAVITATIONAL WAVES GALAXY Formation primordial BLACK HOLES Supermassive BLACK HOLES
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Regulatory elements and transcriptional control of chicken vasa homologue(CVH)promoter in chicken primordial germ cells
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作者 So Dam Jin Bo Ram Lee +3 位作者 Young Sun Hwang Hong Jo Lee Jong Seop Rim Jae Yong Han 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2017年第2期490-500,共11页
Background: Primordial germ cells(PGCs), the precursors of functional gametes, have distinct characteristics and exhibit several unique molecular mechanisms to maintain pluripotency and germness in comparison to so... Background: Primordial germ cells(PGCs), the precursors of functional gametes, have distinct characteristics and exhibit several unique molecular mechanisms to maintain pluripotency and germness in comparison to somatic cells. They express germ cel-specific RNA binding proteins(RBPs) by modulating tissue-specific cis-and trans-regulatory elements. Studies on gene structures of chicken vasa homologue(CVH), a chicken RNA binding protein, involved in temporal and spatial regulation are thus important not only for understanding the molecular mechanisms that regulate germ cel fate, but also for practical applications of primordial germ cells. However, very limited studies are available on regulatory elements that control germ cel-specific expression in chicken. Therefore, we investigated the intricate regulatory mechanism(s) that governs transcriptional control of CVH.Results: We constructed green fluorescence protein(GFP) or luciferase reporter vectors containing the various 5′ flanking regions of CVH gene. From the 5′ deletion and fragmented assays in chicken PGCs, we have identified a CVH promoter that locates at-316 to +275 base pair fragment with the highest luciferase activity. Additional y, we confirmed for the first time that the 5′ untranslated region(UTR) containing intron 1 is required for promoter activity of the CVH gene in chicken PGCs. Furthermore, using a transcription factor binding prediction, transcriptome analysis and siR NA-mediated knockdown,we have identified that a set of transcription factors play a role in the PGC-specific CVH gene expression.Conclusions: These results demonstrate that cis-elements and transcription factors localizing in the 5′ flanking region including the 5′ UTR and an intron are important for transcriptional regulation of the CVH gene in chicken PGCs. Final y,this information wil contribute to research studies in areas of reproductive biology, constructing of germ cel-specific synthetic promoter for tracing primordial germ cells as wel as understanding the transcriptional regulation for maintaining germness in PGCs. 展开更多
关键词 Chicken Chicken vasa homologue primordial germ cel Regulatory element siRNA-mediated knockdown
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Lunar surface mineralogy using hyperspectral data: Implications for primordial crust in the Earth-Moon system
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作者 V. Sivakumar 《Geoscience Frontiers》 SCIE CAS CSCD 2017年第3期457-465,共9页
Mineralogy of the Lunar surface provides important clues for understanding the composition and evo- lution of the primordial crust in the Earth-Moon system. The primary rock forming minerals on the Moon such as pyroxe... Mineralogy of the Lunar surface provides important clues for understanding the composition and evo- lution of the primordial crust in the Earth-Moon system. The primary rock forming minerals on the Moon such as pyroxene, olivine and plagioclase are potential tools to evaluate the Lunar Magma Ocean (LMO) hypothesis. Here we use the data from Moon Mineralogy Mapper (M3) onboard the Chandrayaan- 1 project of India, which provides Visible/Near Infra Red (NIR) spectral data (hyperspectral data) of the Lunar surface to gain insights on the surface mineralogy. Band shaping and spectral profiling methods are used for identifying minerals in five sites: the Moscoviense basin, Orientale basin, Apollo basin, Wegener crater-highland, and Hertzsprung basin. The common presence of plagioclase in these sites is in conformity with the anorthositic composition of the Lunar crust. Pyroxenes, olivine and Fe-Mg-spinel from the sample sites indicate the presence of gabbroic and basaltic components. The compositional difference in pyroxenes suggests magmatic differentiation on the Lunar surface. Olivine contains OH/H20 band, indicating hydrous phase in the primordial magmas. 展开更多
关键词 Moon Mineralogy Mapper Lunar Magma Ocean primordial crust Magmatic differentiation Chandrayaan-1
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Differential transcriptional regulation of the NANOG gene in chicken primordial germ cells and embryonic stem cells
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作者 Hee Jung Choi So Dam Jin +3 位作者 Deivendran Rengaraj Jin Hwa Kim Bertrand Pain Jae Yong Han 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2021年第3期877-890,共14页
Background:NANOG is a core transcription factor(TF)in embryonic stem cells(ESCs)and primordial germ cells(PGCs).Regulation of the NANOG gene by TFs,epigenetic factors,and autoregulatory factors is well characterized i... Background:NANOG is a core transcription factor(TF)in embryonic stem cells(ESCs)and primordial germ cells(PGCs).Regulation of the NANOG gene by TFs,epigenetic factors,and autoregulatory factors is well characterized in ESCs,and transcriptional regulation of NANOG is well established in these cells.Although NANOG plays a key role in germ cells,the molecular mechanism underlying its transcriptional regulation in PGCs has not been studied.Therefore,we investigated the mechanism that regulates transcription of the chicken NANOG(cNANOG)gene in PGCs and ESCs.Results:We first identified the transcription start site of cNANOG by 5′-rapid amplification of cDNA ends PCR analysis.Then,we measured the promoter activity of various 5′flanking regions of cNANOG in chicken PGCs and ESCs using the luciferase reporter assay.cNANOG expression required transcriptional regulatory elements,which were positively regulated by POU5F3(OCT4)and SOX2 and negatively regulated by TP53 in PGCs.The proximal region of the cNANOG promoter contains a positive transcriptional regulatory element(CCAAT/enhancer-binding protein(CEBP)-binding site)in ESCs.Furthermore,small interfering RNA-mediated knockdown demonstrated that POU5F3,SOX2,and CEBP played a role in cell type-specific transcription of cNANOG.Conclusions:We show for the first time that different trans-regulatory elements control transcription of cNANOG in a cell type-specific manner.This finding might help to elucidate the mechanism that regulates cNANOG expression in PGCs and ESCs. 展开更多
关键词 CHICKEN Embryonic stem cells NANOG gene primordial germ cells Regulatory elements
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Do Very Short Gamma Ray Bursts Originate from Primordial Black Holes? Review
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作者 David B. Cline Stanislaw Otwinowski +1 位作者 Bozena Czerny Agnieszka Janiuk 《International Journal of Astronomy and Astrophysics》 2011年第3期164-172,共9页
We present the state of current research of Very Short Gamma Ray Bursts (VSGRBs) from seven GRB detectors. We found that VSGRBs form distinct class of GRBs, which in our opinion, in most cases can originate from the e... We present the state of current research of Very Short Gamma Ray Bursts (VSGRBs) from seven GRB detectors. We found that VSGRBs form distinct class of GRBs, which in our opinion, in most cases can originate from the evaporating Primordial Black Holes (PBHs). Arguments supporting our opinion: 1) GRBs with time duration (T90) < 100 ms form distinct class: VSGRBs. 2) We observe significant anisotropy in the galactic angular distribution of BATSE VSGRB events. 3) V/Vmax distribution for BATSE VSGRB events indicates the local distance production. 4) VSGBBs have more energetic γ-ray burst than other GRBs with longer duration (KONUS). 5) We observe small number of afterglows in SWIFT VSGRB sample (25%), in contrast with the noticeable afterglow frequency in SGRB sample (78%). 6) Time profile of rising part BATSE VSGRBs is in agreement with the evaporation PBH model. 展开更多
关键词 BLACK HOLE Physics COSMOLOGY GAMMA RAY BURST primordial BLACK HOLE
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The Predatory Function of Three Spiders to Two Insect Pests in Rice Within a Multi-species Co-existence System
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作者 LI Jian-quan, SHEN Zuo-rui and ZHAO Zhi-mo( College of Plant Protection , China Agricultural University, Beijing 100094 , P.R. China Department of Plant Protection , South-west Agricultural University, Chongqing 400716 , P.R. China) 《Agricultural Sciences in China》 CAS CSCD 2002年第4期391-396,共6页
The prey-seeking behavior of three spiders (X1-Pirata subpiraticus, X2-Clubiona japonicola and X3-Tetragnatha japonica) for brown plant hopper (X4-Nilaparvata lugens) and rice spittle bug (X5-Cal-litettix versicolor) ... The prey-seeking behavior of three spiders (X1-Pirata subpiraticus, X2-Clubiona japonicola and X3-Tetragnatha japonica) for brown plant hopper (X4-Nilaparvata lugens) and rice spittle bug (X5-Cal-litettix versicolor) was investigated, as well as how interference between and within species occurred, by using a quadratic regression rotational composite design. Six predation models derived from the analysis of interactions among and within predators and preys were developed. The total predatory capacity of spiders on rice insect pests after coexistence for one day can be expressed as follows: Y3 = 32.795 + 2.25X1 + 1.083X2 + 0.5X3 + 10.167X4 + 3.167X5 - 1.67X12 - 2.42X22 - 3.295X32 - 0.045X42 + 0.455X52 - 3.125X1X2 + 0.375X1X3 -0.625X1X4 - 0.375X1X5 + 0.375X2X3 - 0.875X2X4 + 0.125X2X5 + 0.375X3X4 - 0.375X3X5 + 0.125X4X5. The principal efficiency analysis using this model indicated that increases in insect pest density significantly increased predation by predators; this was much greater than the effect of any single predator. X4 had a greater effect than X5; however, X4 and X5 demonstrated little interspecific interference and even promoted each other and increased predation rates as the densities of the two pests increased. Among the three predators, an increase in the density of X, had the greatest effect on the increase in predation, X3 had the second, X2 the third greatest effect. As predator density increased inter- and intra-species interference occurred, which were largely related to the size, activity, niche breadth, niche overlap and searching efficiency of the predators. X2 produced the greatest interference between different individuals and between any other predator species. X3 had the second greatest, which reduced predation levels at high predator densities. Because of these factors, the highest predation rate was obtained at a prey density of 120 per 4 rice-hills. The optimal proportion of the three predators in the multi-predator prey system was X1: X2: X3 = 5.6:1.3:4.1. 展开更多
关键词 Spiders Predation BIO-CONTROL Intra-species relationships co-existence system Interaction Intraspecific competition Interspecific competition Animal behavior Natural enemies Rice insect pest
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Kanzanise Empimba za Nzima Atarikimanya Akangaya: The Story of Play-beans in Promoting Peaceful Co-existence
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作者 Emmanuel Mutungi 《Journal of Literature and Art Studies》 2020年第12期1162-1169,共8页
Afrikan narratives such as folktales,proverbs and taboos were clear systems and structures on which societies operated.These were used to guide society’s values that promoted trust,accountability,self respect and man... Afrikan narratives such as folktales,proverbs and taboos were clear systems and structures on which societies operated.These were used to guide society’s values that promoted trust,accountability,self respect and many more for the wellbeing of the entire community.This paper discussesone of the Banyankole folktale Kanzanise empimba za Nzima atarikimanya akangaya(Let me stand in the gap of my sister(Nzima)while she is away or else,I will be shamed in case she knows I did not).The purpose of the paper is to demonstrate how Afrikan indigenous knowledge and specifically this folktale Kanzanise empimba za Nzima atarikimanya akangaya inculcated in the community a spirit of care,commitment to one another and transparency which are fundamental values that create peaceful societies.The paper argues that there is a wealth of wisdom residing in the African cultures to be exploited to guide African policy development.This will raise African indigenous knowledge to a platform worth recognition for its contribution towards positive transformation.Furthermore,that the Western systems and structures currently guiding Afrikan policy development are oblivious of the richness of Afrikan indigenous knowledge that united the people.The paper concludes that for Afrikans to contribute to the global agenda,they need to bring to the table of globalization a unique product such as the Afrikan indigenous narratives that contribues to world peace.The paper recommends moving back into our past,identify and promote those unique Afrikan values that sustained Africa before the Western influence. 展开更多
关键词 Afrikan narratives folktale co-existence sustainable development insights
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