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Epidermal Patterning Genes Impose Non‐cell Autonomous Cell Size Determination and have Additional Roles in Root Meristem Size Control

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Journal of Integrative Plant Biology 2013年第9期55卷 864-875页

作者： Christian lfke Kai Dünser Jürgen Kleine‐Vehn Department of Applied Genetics and Cell Biology Vienna Institute of Biotechnology (VIBT) University of Natural Resources and Life Sciences Vienna (BOKU)Muthgasse 18 1190 Vienna Austria

The regulation of cellular growth is of vital importance for embryonic and postembryonic patterning. Growth regulation in the epidermis has importance for organ growth rates in roots and shoots, proposing epidermal cells as an interesting model for cellular growth regulation. Here we assessed whether the root epidermis is a suitable model system to address cell size determination. In Arabidopsis thaliana l., root epidermal cells are regularly spaced in neighbouring tricho-（root hair） and atrichoblast （non-hair） cells, showing already distinct cell size regulation in the root meristem. We determined cell sizes in the root meristem and at the onset of cellular elongation, revealing that not only division rates but also cellular shape is distinct in tricho-and atrichoblasts. Intriguingly, epidermal-patterning mutants, failing to define differential vacuolization in neighbouring epidermal cell files, also display non-differential growth. Using these epidermal-patterning mutants, we show that polarized growth behaviour of epidermal tricho-and atrichoblast is interdependent, suggesting non-cell autonomous signals to integrate tissue expansion. Besides the interweaved cell-type-dependent growth mechanism, we reveal an additional role for epidermal patterning genes in root meristem size and organ growth regulation. We conclude that epidermal cells represent a suitable model system to study cell size determination and interdependent tissue growth.

关键词： Atrichobtast cell size determination trichoblast,

Contemporary Approaches for Identifying Rare Bone Disease Causing Genes

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Bone Research 2013年第4期1卷 301-310页

作者： Charles R.Farber Thomas l.Clemens Center for Public Health Genomics University of Virginia Departments of Public Health Sciences and Biochemistry and Molecular Genetics University of Virginia Department of Orthopaedic Surgery Johns Hopkins School of Medicine Baltimore Veterans Administration Medical Center

Recent improvements in the speed and accuracy of DNA sequencing, together with increasingly sophisti- cated mathematical approaches for annotating gene networks, have revolutionized the field of human genetics and made these once time consuming approaches assessable to most investigators. In the field of bone research, a particularly active area of gene discovery has occurred in patients with rare bone disorders such as osteogenesis imperfecta （OI） that are caused by mutations in single genes. In this perspective, we highlight some of these technological advances and describe how they have been used to identify the genetic determinants underlying two previously unexplained cases of OI. The widespread availability of advanced methods for DNA sequencing and bioinformatics analysis can be expected to greatly facilitate identification of novel gene networks that normally function to control bone formation and maintenance.

关键词： exome sequencing genome sequencing bioinformatics osteogenesis imperfect pigment epithelium-derived factor (PEDF) bone restricted ifitm-like protein (Bril)

Hydrophobic Effect in a Continuum Model of the lipid Bilayer

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Communications in Computational Physics 2009年第8期6卷 655-672页

作者： Phillip l.Wilson Huaxiong Huang Shu Takagi Department of Mathematics and Statistics University of CanterburyPrivate Bag 4800Christchurch 8140New Zealand Department of Mathematics and Statistics York UniversityTorontoM3J 1P3Canada Department of Mechanical Engineering The University of TokyoTokyoJapan

We study a continuum paradigm of the lipid bilayer based on minimizing the free energy of a mixture of water and lipid *** paper extends previous work of Blom and Peletier[European ***.,15(2004),pp.487-508]in the following ways.(a)It formulates a more general model of the hydrophobic effect to facilitate connections with microscale simulations and first-principles analysis.(b)It clarifies the meaning and role of the model parameters.(c)It outlines a method for determining parameter values so that physically-realistic bilayer density profiles can be obtained,for example for use in macroscale ***(a)-(c)suggest that the model has potential to robustly connect some micro-and macroscale levels of multiscale blood flow *** mathematical modelling in point(a)is based upon a consideration of the underlying physics of inter-molecular *** governing equations thus obtained are minimized by gradient flows via a novel numerical approach;this enables point(b).The numerical results are shown to behave physically in terms of the effect of background concentration,in contrast to the earlier model which is shown here to not display the expected behaviour.A“short-tail”approximation of the lipid molecules also gives an analytical tool which yields critical values of some parameters under certain ***(c)involves the first quantitative comparison of the numerical data with physical experimental results.

关键词： lipid bilayer free energy continuum model numerical minimization

A Study on Impervious and Heat-Insulating Performance of Geomembrane Composites Within Breakwater

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China Ocean Engineering 1997年第2期12卷 213-224页

作者： Tao, TK Yu, l Yan, J Dong, ZY Hydraulic Engineering Department Nanjing Hydraulic Research Institute Nanjing 210029 China

This paper investigates the performance of geomembrane composites used as impervious and heat-insulating lining within a breakwater for a power station. The seepage field, distribution of stress-strain contour and seepage discharge of hot water which has been treated as the inner thermal source in the calculation of heat-insulation, have been given by three-dimensional calculation method coupling seepage with stress. The results indicate that the impervious and heat-insulation effect of geomembrane composites is significant.

关键词： breakwaters geomembrane composite impervious and heat-insulation

Environmental chemical stressors as epigenome modifiers:a new horizon in assessment of toxicological effects

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Chinese Science Bulletin 2014年第4期59卷 349-355页

作者： Heqing Shen F.l.Martin Yanhua Su Key laboratory of Urban Environment and Health Institute of Urban Environment Chinese Academy of Sciences Centre for Biophotonics Lancaster Environment CentreLancaster University Department of Preventive Medicine School of Public Health of Xiamen University

In eukaryotic cells, chromatin transformation from euchromatin into heterochromatin as a means of controlling gene expression and replication has been known as the ‘‘accessibility hypothesis' '. The interplay of epigenetic changes including histone modifications, DNA methylation, RNA interference(RNAi) and other func- tional epigenetic components are intricate. It is believed that these changes are well-programmed, inherited and can be modified by environmental contaminant stressors. Environmentally-driven epigenetic alterations during development, e.g. embryonic, foetal or neonatal stage, may influence disease susceptibility in adulthood. Therefore, understanding how epigenome modifications develop in response to environmental chemicals and, how epigenetic-xenobiotic interactions influence human health will shed new insights into gene-environment interactions in the epidemiology of several diseases including cancer. In this review, we consider studies of chemical modifiers including nutritional and xenobiotic effects on epigenetic components in vitro or in vivo. By examining the most-studied epigenome modifications and how their respective roles are interlinked, we highlight the central role of xenbiotic- modified epigenetic mechanisms. A major requirement will be to study and understand effects following environmentally-relevant exposures. We suggest that the study of epigenetic toxicology will open up new opportunities to devise strategies for the prevention or treatment of at-risk populations.

关键词：环境化学基因修饰压力源表观毒理效应评估 DNA甲基化相互作用

liquid-liquid Equilibrium for Extraction of Benzene from 1-Hexene Using Two Different Solvents

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China Petroleum Processing & Petrochemical Technology 2018年第1期20卷 61-66页

作者： lü Yan li Songyuan Xin Kun lin yun The State Key lab of Chemical Engineering College of Chemical EngineeringEast China University of Science and TechnologyShanghai 200237 Department of Chemical Engineering and Chemistry Eindhoven University of TechnologyDe ZaaleEindhoventhe Netherlands

Two different solvents had been used to separate benzene from 1-hexene under atmosphere pressure by employing one of the following two solvents, viz.: dimethyl sulfoxide (DMSO) at 298.15 K and 318.15 K, and furfural at 298.15 K. A series of liquid-liquid equilibrium (llE) data had been obtained and the distribution coefficient together with the separation factor were calculated from them. Both the NRTl and the UNIQUAC models could fit in with the experimental data quite well.

关键词： liquid-liquid equilibria benzene 1-hexene furfural dimethyl sulfoxide

Animal models for the study of hepatitis C virus infection and replication

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World Journal of Gastroenterology 2012年第23期18卷 2909-2913页

作者： Kristin l MacArthur Catherine H Wu George Y Wu Department of Medicine Beth Israel Deaconess Medical Center Boston MA 02215 United States Department of Medicine Division of Gastroenterology-Hepatology University of Connecticut Health Center Farmington CT 06030-1845 United States

Hepatitis C virus (HCV) hepatitis, initially termed non-A, non-B hepatitis, has become one of the leading causes of cirrhosis and hepatocellular carcinoma worldwide. With the help of animal models, our understanding of the virus has grown substantially from the time of initial discovery. There is a paucity of available animal models for the study of HCV, mainly because of the selective susceptibility limited to humans and primates. Recent work has focused modification of animals to permit HCV entry, replication and transmission. In this review, we highlight the currently available models for the study of HCV including chimpanzees, tupaia, mouse and rat models. Discussion will include methods of model design as well as the advantages and disadvantages of each model. Particular focus is dedicated to knowledge of pathophysiologic mechanisms of HCV infection that have been elucidated through animal studies. Research within animal models is critically important to establish a complete understanding of HCV infection, which will ultimately form the basis for future treatments and prevention of disease.

关键词： Hepatitis C virus Infection Replication Vac-cine Hepatitis A virus

EXPERIMENTAl APPlICATION OF A THINNING SCHEME FOR THE ASSIMIlATION OF SURFACE OBSERVATION DATA IN GRAPES-3DVAR

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Journal of Tropical Meteorology 2018年第3期24卷 334-345页

作者： ZHAO Hong l1U Yin luhe Meteorological Bureau Nanjing 211599 China Jiangsu Meteorological Observation Center Nanjing 210009 China Jiangsu Institute of Meteorological Sciences Nanjing 210009 China

To reduce the spatial correlation of representation error in observations and computational complexity, we propose a thinning scheme that can extract typical observations within a certain range. This scheme is applied to the Global/Regional Assimilation and Prediction System(GRAPES) with three-dimensional variation(3 DVAR) to study the effect of the thinning radius on the assimilation results. The assimilation experiments indicate that when the ratio of the model resolution to the observational resolution is 1:3, the simulated results for precipitation are relatively good and have a relatively high equitable threat score(ETS). Moreover, the analysis errors in the temperature and the specific humidity are the smallest, the dependence of the norm gradient vector of the objective function on the number of iterations is slow, gentle, and close to 0, and the minimization results in improved conditions.

关键词： thinning typical observation data assimilation

A new currency for mutualism?Fungal endophytes alter antioxidant activity in hosts responding to drought

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Fungal Diversity 2012年第3期54卷 39-49页

作者： Cyd E.Hamilton Taryn l.Bauerle MTT Agrifood and Biotech Plant Production UnitJokioinenFinland Cornell University HorticultureIthacaNYUSA

Fungal endophytes have significant effects on host performance including but not limited to changes in reproductive output,as well as,biotic and abiotic stress *** ultimate mechanisms for resistance to herbivory have been documented in a number of fungal-plant symbiota and involve the production of alkaloids by the *** have thus been defined as a currency responsible for increased host resistance to *** provide support for the hypothesis that another currency may be responsible for increased host tolerance to abiotic stress resulting from endophyte colonization;namely *** report comparatively higher activity of antioxidants in endophyte colonized hosts resulting from abiotic stress and propose antioxidants are another currency via which mutualistic interactions between fungal endophytes and their hosts can *** recognize fungal endophyte interactions are diverse and complex and include antagonisms,commensalisms,and mutualisms.

关键词： Symbiont Stress Epichloe Neotyphodium Stress tolerance Reactive oxygen species