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SUPPRESSOR OF VAriEGATION4, a New var2 Suppressor Locus, Encodes a Pioneer Protein that Is Required for Chloroplast Biogenesis

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Molecular Plant 2011年第2期4卷 229-240页

作者： Fei Yu ung-Soon Park Xiayan Liu Andrew Foudree Aigen Fu Marta Powikrowska Anastassia Khrouchtchova Poul Erik Jensen Jillian N. Kriger gordon ri gray Steven R. Rodermel College of Life Sciences Northwest A&F University Yangling Shaanxi 712100 People's Republic of China Department of Plant and Microbial Biology University of California Berkeley Berkeley CA 94720 USA Department of Genetics Development and Cell Biology iowa State University 253 Bessey Hall Ames IA 50011 USA Department of Plant Biology and Biotechnology Faculty of Life Sciences University of Copenhagen Thorvaldsensvej 40 DK-1871 Frederiksberg C Denmark Department of Plant Sciences University of Saskatchewan Saskatoon Saskatchewan S7N 5A8 Canada

VAR2 is an integral thylakoid membrane protein and a member of the versatile FtsH class of metalloproteases in prokaryotes and eukaryotes. Recessive mutations in the VAR2 locus give rise to variegated plants （var2） that contain white sectors with abnormal plastids and green sectors with normal-appearing chloroplasts. In a continuing effort to isolate second-site suppressors of var2 variegation, we characterize in this report ems2505, a suppressor strain that has a virescent phenotype due to a missense mutation in At4g28590, the gene for a pioneer protein. We designated this gene SVR4 （for SUPPRESSOR OF VAriEGATION4） and the mutant allele in ems2505 as svr4-1. We demonstrate that SVR4 is located in chloroplasts and that svr4-1 single mutants are normal with respect to chloroplast anatomy and thylakoid membrane protein accumulation. However, they are modestly impaired in several aspects of photochemistry and have enhanced non-photochemical quenching （NPQ） capacity. A T-DNA insertion allele of SVR4, svr4-2, is seedling-lethal due to an early blockage of chloroplast development. We conclude that SVR4 is essential for chloroplast biogenesis, and hypothesize that SVR4 mediates some aspect of thylakoid structure or function that controls NPQ. We propose that in the suppressor strain, photoinhibitory pressure caused by a lack of VAR2 is ameliorated early in chloroplast development by enhanced NPQ capacity caused by reduced SVR4 activity. This would result in an increase in the number of chloroplasts that are able to surmount a threshold necessary to avoid photo-damage and thereby develop into functional chloroplasts.

关键词： Arabidopsis chloroplast biogenesis non-photochemical quenching (NPQ) photo-damage suppressor strain variegation

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Debris flow impact on flexible barrier: effects of debrisbarrier stiffness and flow aspect ratio

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Journal of Mountain Science 2019年第7期16卷 1629-1645页

作者： SONG Dong-ri ZHOU gordon G.D CHOI Clarence Edward ZHENG Yun Key Laboratory of Mountain Hazards and Earth Surface Process/Institute of Mountain Hazards and Environment Chinese Academy of SciencesChengdu 610041China University of Chinese Academy of Sciences Beijing 100049China Department of Civil and Environmental Engineering Hong Kong University of Science and TechnologyClear Water BayKowloonHong Kong SARChina The HKUST Jockey Club Institute for Advanced Study Hong Kong SARChina

Conventionally,flexible barriers are rated based on their ability to resist a free-falling boulder with a particular input ***,there is still no well-accepted approach for evaluating performance of flexible barrier under debris flow *** this study,a large-nonlinear finite-element model was used to back-analyze centrifuge tests to discern the effects of impact material type,barrier stiffness,and flow aspect ratio(flow height to flow length)on the reaction force between the impacting medium and flexible *** show that,in contrast to flexible barriers for resisting rockfall,the normal impact force induced by the highly frictional and viscous debris is insensitive to barrier *** is because the elongated distributions of kinetic energy are mainly dissipated by the internal and boundary shearing,and only a small portion is forwarded to the ***,a new stiffness number is proposed to characterize the equivalent stiffness between a debris flow or a boulder,and a flexible *** the circumstance of an extremely elongated debris flow event,i.e.,low aspect ratio,the load on a barrier is dominated by the static component and thus not sensitive to the barrier stiffness.

关键词： Debris flow Flexible barrier Impact Stiffness Flow aspect ratio

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Compression characteristics of saturated re-compacted glacial tills in Tianmo Gully of Tibet, China

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Journal of Mountain Science 2019年第7期16卷 1661-1674页

作者： CHEN Lei-lei ZHOU gordon G.D MU Qing-yi CUI Kahlil Fredrick SONG Dong-ri Key Laboratory of Mountain Hazards and Earth Surface Process Institute of Mountain Hazards and EnvironmentChinese Academy of SciencesChengdu 610041China University of Chinese Academy of Sciences Beijing 100049China Department of Civil Engineering Xi'an Jiaotong UniversityXi'an 710049China

Glacial tills are highly compressible soils composed of loosely cemented sandy silt *** role,for instance,as initial filler materials in geo-technical projects along temperate glacier regions warrant a systematic evaluation of their compressive *** such,we carry out a series of onedimensional compression tests on re-compacted glacial till samples obtained from Tianmo Gully,Tibet,with the aims of evaluating their compressive behavior under controlled initial stress *** yield stress was determined from the void ratio versus consolidation pressure(e-log)*** compression and swelling behaviors were observed during the primary and secondary compressions of the consolidation *** the compression curves,a correlation can be found between the consolidation stress and the void *** addition,we find that the compression curves of glacial tills collapse into a single curve when normalized by the compression *** experimental results in this study provide a basic understanding of the compression characteristics of the glacial tills in Tibet,China.

关键词： Glacial till Compression characteristics One-dimensional consolidation tests Consolidation stress Compression curve

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Influence of inflow discharge and bed erodibility on outburst flood of landslide dam

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Journal of Mountain Science 2019年第4期16卷 778-792页

作者： ZHOU Ming-jun ZHOU gordon G.D. CUI Kahlil Fredrick E. SONG Dong-ri LU Xue-qiang Key Laboratory of Mountain Hazards and Earth Surface Process/Institute of Mountain Hazards and Environment Chinese Academy of Sciences University of Chinese Academy of Sciences

Accurate prediction of the hydrographs of outburst floods induced by landslide dam overtopping failure is necessary for hazard prevention and mitigation. In this study, flume model tests on the breaching of landslide dams were conducted. Unconsolidated soil materials with wide grain size distributions were used to construct the dam. The effects of different upstream inflow discharges and downstream bed soil erosion on the outburst peak discharge were investigated. Experimental results reveal that the whole hydrodynamic process of landslide dam breaching can be divided into three stages as defined by clear inflection points and peak discharges. The larger the inflow discharge, the shorter the time it takes to reach the peak discharge, and the larger the outburst flood peak discharge. The scale of the outburst floods was found to be amplified by the presence of an erodible bed located downstream of the landslide dam. This amplification decreases with the increase of upstream inflow. In addition, the results show that the existence of an erodible bed increases the density of the outburst flow, increasing its probability of transforming from a sediment flow to a debris flow.

关键词： Landslide dam Inflow discharge Erodible bed Outburst flood

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Effects of water content on the shear behavior and critical state of glacial till in Tianmo Gully of Tibet, China

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Journal of Mountain Science 2019年第8期16卷 1743-1759页

作者： ZHOU gordon G.D. CHEN Lei-lei MU Qing-yi CUI Kahlil Fredrick E. SONG Dong-ri Key Laboratory of Mountain Hazards and Earth Surface Process Institute of Mountain Hazards and EnvironmentChinese Academy of Sciences(CAS)Chengdu 610041China University of Chinese Academy of Sciences Beijing 100049China Department of Civil Engineering Xi'an Jiaotong UniversityXi'an 710049China

Glacial tills are widely distributed in Tibet, China, and are highly susceptible to landslides under intense rainfalls. Failures of the slope during rainfall are closely related to the shear behavior of glacial tills at different moisture conditions. This study investigates the shear behavior and critical state of saturated and unsaturated glacial tills through a series of drained direct shear tests. The tests were conducted on two types of compacted glacial tills with different water contents and total normal stresses. A strain softening mode of failure is observed for all water content conditions accompanied by noticeable dilation. Dilatancy is found to decrease with increasing water content. Unsaturated samples showed increased rates of dilation as water content is decreased for all applied normal stresses a behavior which cannot be predicted well by classical stressdilatancy models. Furthermore, it was found that the Critical State Line(CSL), plotted on the(e-ln) plane, can be used to define the shear behavior of unsaturated glacial tills at different water *** CSL of saturated glacial tills run parallel to this line. The experimental results in this study are aimed to provide a basic understanding to the underlying failure mechanisms of glacial tills.

关键词： Glacial till Shear behavior Water content Dilatancy Direct shear test Critical state

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Saline conducted electric coagulation (SCEC):original experience in experimental hepatectomy

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2012年第3期13卷 186-191页

作者： Guo-ping DING Li-ping CAO Da-ren LIU ri-sheng QUE Department of General Surgery the Second Affiliated Hospital School of Medicine Zhejiang University Hangzhou 310009 China

Objective: To evaluate the feasibility and superiority of a new coagulating and hemostatic method named "saline conducted electric coagulation (SCEC)". Methods: The Peng's multifunction operative dissector (PMOD) was modified to enable saline to effuse persistently out of its nib at a constant speed. In a group of six New Zealand rabbits, two hepatic lobes of each rabbits were resected respectively by SCEC and conventional electric coagulation (EC). The features of SCEC were recorded by photo and compared with conventional EC. After 7 d, the coagulating depth was measured in each residual hepatic lobe. Hepatic tissue was dyed by hematoxylin and eosin (HE) and studied under a microscope. Results: The coagulating depth increased with the continuation of SCEC time. Hepatectomies were performed successfully, no rabbit died in the perioperative period. The incisal surface of SCEC was gray-white with no red bleeding point. There was a thick solidified layer at the margin and a thin red-white intermittent layer between the solidified layer and normal hepatic tissue at the vertical section of SCEC. The mean coagulating depth of SCEC was 1.8 cm vs. 0.3 cm of conventional EC. Pathological examination showed a mild inflammatory reaction by SCEC. Conclusions: SCEC is a feasible and safe method for surgical hemostasis. As a new technique for liver resection, SCEC shows better coagulating effect and milder inflammatory reaction than conventional EC. Our study shows bloodless liver resection can also be performed by SCEC, especially for liver malignant tumor.

关键词： Saline Electric coagulation Hepatectomy Hemostasis Bloodless liver resection

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Effects of plant-derived analgesic compounds sinomenine and salvinorin A in infant rats

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Journal of Integrative Medicine 2020年第2期18卷 174-180页

作者： Conrad J.Mascarenhas Renyu Liu gordon A.Barr Department of Anesthesiology and Critical Care Children’s Hospital of PhiladelphiaPhiladelphiaPA 19104USA Department of Anesthesiology and Critical Care Perelman School of Medicine at the University of PennsylvaniaPhiladelphiaPA 19104USA Department of Psychology University of PennsylvaniaPhiladelphiaPA 19104USA

Objective: Premature and ill neonates undergo painful but medically necessary procedures while hospitalized. Although opiate drugs are administered as analgesics, problems associated with their side effects,tolerance, and potential dependence necessitate research into alternative pain-relieving *** we test two plant-derived compounds in infant rats: sinomenine, which targets the Mas-related G-protein-coupled receptor member X2 opioid receptor;and salvinorin A, which is a j opioid receptor agonist. In adult animals both sinomenine and salvinorin A are analgesic, but neither has been tested in ***: We used the formalin and thermal plantar tests in rats 7 and 21 days of age(PN7 and PN21) for behavioral signs of pain. In addition, brain sections were stained using Fos immunohistochemistry to examine patterns of brain activation in the midbrain periaqueductal gray and the paraventricular nucleus of the ***: Sinomenine was analgesic in both the formalin and thermal tests on animals 21 days of age. At PN7 only the highest dose elevated response latencies in the thermal test and there were no effects of sinomenine in the formalin test. Analysis of Fos expression in the sinomenine-treated animals showed no drug effect, in contrast to the behavioral results. Salvinorin A was analgesic in the formalin test only at the highest dose at 21 days of age but not in the thermal test at either ***: The increased modest effectiveness of sinomenine in older animals and the minimum salvinorin A drug effect suggest that the compounds act on sites that develop during the preweaning period(sinomenine) or after weaning(salvinorin A).

关键词： Thermal pain Formalin test Fos Ontogeny Sinomenine Salvinorin A

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Effect of herpesvirus infection on pancreatic duct cell secretion

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World Journal of Gastroenterology 2005年第38期11卷 5997-6002页

作者： Péter Hegyi Balázs rdg Zoltán Rakonczai Jr Tamás Takács János Lonovics Annamária Szabolcs Réka Sári András Tóth Julius G Papp András Varró Mária K Kovács Mike A gray Barry E Argent Zsolt Boldogki First Department of Medicine Department of Biology Division of Cardiovascular Pharmacology School of Cell and Molecular Biosciences

AIM： To examine the effect of acute infection caused by herpesvirus （pseudorabies virus, PRV） on pancreatic ductal secretion. METHODS： The virulent Ba-DupGreen （BDG） and non- virulent Ka-RREp01acgfp （KEG） genetically modified strains of PRV were used in this study and both of them contain the gene for green fluorescent protein （GFP）. Small intra/ interlobular ducts were infected with BDG virus （10^7 PFU/mL for 6 h） or with KEG virus （10^10 PFU/mL for 6 h）, while non-infected ducts were incubated only with the culture media. The ducts were then cultured for a further 18 h. The rate of HCO3 secretion [base efflux -λ（B）] was determined from the buffering capacity of the cells and the initial rate of intracellular acidification （1） after sudden blockage of basolateral base loaders with dihydro-4,4,- diisothiocyanatostilbene-2,2,-disulfonic acid （500 μmol/L） and amiloride （200 μmol/L）, and （2） after alkali loading the ducts by exposure to NH4Cl. All the experiments were performed in HCO3-buffered ringer solution at 37 ℃ （n = 5 ducts for each experimental condition）. Viral structural proteins were visualized by immunohistochemistry. Virallyencoded GFP and immunofluorescence signals were recorded by a confocal laser scanning microscope.RESULTS： The BDG virus infected the majority of accessible cells of the duct as judged by the appearance of GFP and viral anUgens in the ductal cells. KEG virus caused a similarly high efficiency of infection. After blockage of basolateral base loaders, BDG infection significantly elevated -λB-） 24 h after the infection, compared to the non-infected group. However, KEG infection did not modify -λB-）. After alkali loading the ducts, -λB-） was significantly elevated in the BDG group compared to the control group 24 h after the infection. As we found with the inhibitor stop method, no change was observed in the group KEG compared to the non-infected group. CONCLUSION： Incubation with the BDG or KEG strains of PRV results in an effective i

关键词： Pancreas Hypersecretion Ductal cells Infection Pseudorabies virus

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Mn＋1AXn Phonon Density of States： Ti3AlC2 and Ti3SiC2 Simulation and Experimentation Results

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Journal of Chemistry and Chemical Engineering 2015年第4期9卷 253-261页

作者： Veronica gray gordon J Kearley Oliver Kirstein Ramzi Kutteh Erich H Kisi Daniel P. riley Frans Trouw School of Engineering University of Newcastle Callaghan NSW 2308 Australia Bragg Institute Australian Nuclear Science & Technology Organisation Lucas Heights NEW 2234 Australia European Spallation Source ESS AB Lund 22100 Sweden School of Physics University of Sydney Sydney NEW2006 Australia Institute of Materials Engineering Australian Nuclear Science & Technology Organisation Lucas Heights NEW2234 Australia Lujan Centre Los Alamos Neutron Science Center Los Alamos National Laboratory Los Alamos NM 87545 USA

For the first time detailed measurements of the DOS （density of states） for Ti3AIC2 and Ti3SiC2 are presented at temperatures between T = 10 and 100 K. For Ti3AIC2 a DFT （density functional theory） simulation of lattice dynamics is compared to experimental data demonstrating a noticeable difference between the spectra especially below 40 meV. In the case of Ti3SiC2 the DFT model is augmented with MD （molecular dynamics） simulations resulting in the measured and simulated spectra resembling one another more closely but still having significant differences below 40 meV. Within the experimental spectra, there are features up to and including 20 meV which are unaccounted for by the simulation. Tracing individual atoms generated by the computer models suggests anharmonic motion of Si within the Ti3SiC2. The results presented could explain differences between calculated elastic moduli using DFT harmonic lattice dynamics simulations and results from recent experiments.

关键词： Anharmonic anisotropic lattice dynamics Mn+1AXn phase ceramics ab initio molecular dynamics.

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Health-education to prevent COVID-19 in schoolchildren: a call to action

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Infectious Diseases of Poverty 2020年第4期9卷 142-144页

作者： Darren J.gray Johanna Kurscheid Mary Lorraine Mationg Gail M.Williams Catherine gordon Matthew Kelly Kinley Wangdi Donald P.McManus Department of Global Health Research School of Population HealthAustralian National UniversityCanberraAustralia School of Public Health University of QueenslandBrisbaneAustralia Infectious Diseases Division QIMR Berghofer Medical Research InstituteBrisbaneAustralia

Background:There is currently considerable international debate around school closures/openings and the role of children in the transmission of coronavirus disease 2019(COVID-19).Whilst evidence suggests that children are not impacted by COVID-19 as severely as adults,little is still known about their transmission potential,and with a lot of asymptomatic cases they may be silent transmitters(*** without showing clinical signs of disease),albeit at a lower level than *** relation to this,it is somewhat concerning that in many countries children are cared for,or are often in close contact with,older individuals such as grandparents—the age group most at risk of acquiring serious respiratory complications resulting in *** text:We emphasise that in the absence of a vaccine or an effective therapeutic drug,preventive measures such as good hygiene practices—hand washing,cough etiquette,disinfection of surfaces and social distancing represent the major(in fact only)weapons that we have against ***,we stress that there is a pressing need to develop specific COVID-19 prevention messages for ***:An entertainment education intervention for schoolchildren systematically implemented in schools would be highly effective and fill this *** such measures in place there would be greater confidence around the opening of schools.

关键词： COVID-19 Children Health education Health promotion Prevention

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