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Association of Psb28 and Psb27 Proteins with PSII-PSI Supercomplexes upon Exposure of Synechocystis sp. PCC 6803 to High Light

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Molecular Plant 2017年第1期10卷 62-72页

作者： Martina Beckova Zdenko Gardian j.anfeng Yu peter Konik peter j. Nixon j.sef Komenda Institute of Microbiology Center Algatech Opatovicky mlyn37981 Trebon Czech Republic Faculty of Science University of South Bohemia Branisovska 1760 37005 Ceske Budejovice Czech Republic Institute of Plant Molecular Biology Biology Centre Academy of Sciences Branisovska 3137005 Ceske Budejovice Czech Republic Sir Ernst Chain Building-Wolfson Laboratories Department of Life Sciences Imperial College London South Kensington Campus London SW7 2AZ UK

Formation of the multi-subunit oxygen-evolving photosystem II （PSII） complex involves a number of auxiliary protein factors. In this study we compared the localization and possible function of two homolo- gous PSU assembly factors, Psb28-1 and Psb28-2, from the cyanobacterium Synechocystis sp. PCC 6803. We demonstrate that FLAG-tagged Psb28-2 is present in both the monomeric PSII core complex and a PSII core complex lacking the inner antenna CP43 （RC47）, whereas Psb28-1 preferentially binds to RC47. When cells are exposed to increased irradiance, both tagged Psb28 proteins additionally associate with oligo- meric forms of PSII and with PSII-PSI supercomplexes composed of trimeric photosystem I （PSI） and two PSII monomers as deduced from electron microscopy. The presence of the Psb27 accessory protein in these complexes suggests the involvement of PSI in PSII biogenesis, possibly by photoprotecting PSII through energy spillover. Under standard culture conditions, the distribution of PSII complexes is similar in the wild type and in each of the single psb28 null mutants except for loss of RC47 in the absence of Psb28-1. In comparison with the wild type, growth of mutants lacking Psb28-1 and Psb27, but not Psb28-2, was retarded under high-light conditions and, especially, intermittent high-light/dark conditions, emphasizing the physiological importance of PSII assembly factors for light acclimation.

关键词： Psb28 proteins photosystem I and II Synechocystis

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Phase Transitions for Products of Characteristic Polynomials under Dyson Brownian Motion

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Acta Mathematica Sinica,English Series 2021年第3期37卷 509-524页

作者： peter j.FORRESTER Dang-Zheng LIU ARC Centre of Excellence for Mathematical and Statistical Frontiers School of Mathematics and StatisticsThe University of MelbourneVictoria 3010Australia CAS Key Laboratory of Wu Wen-Tsun Mathematics School of Mathematical SciencesUniversity of Science and Technology of ChinaHefei 230026P.R.China

We study the averaged products of characteristic polynomials for the Gaussian and Laguerre β-ensembles with external source, and prove Pearcey-type phase transitions for particular full rank perturbations of source. The phases are characterised by determining the explicit functional forms of the scaled limits of the averaged products of characteristic polynomials, which are given as certain multidimensional integrals, with dimension equal to the number of products.

关键词： Random matrices Dyson Brownian motion β-ensembles phase transitions

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Age at reproductive maturity and effect of age and time of day on sex attraction in the potato psyllid Bactericera cockerelli

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Insect Science 2012年第5期19卷 585-594页

作者： Christelle Guedot David R. Horton peter j. Landolt U.S. Department of Agriculture Agricultural Research Service 5230 Konnowac Pass Road Wapato WA 98951 USA

The potato psyllid, Baetericera （= Paratrioza） cockerelli （gulc）（Hemiptera： Triozidae）, is a maj.r pest of potato. Studies were conducted to determine the age at which both males and females reach reproductive maturity and the effect of age and time of day on sex attraction. Adult B. cockerelli reach reproductive maturity within 48 h post-eclosion, with females being mature on the day of eclosion and males at 1 day post-eclosion. Oviposition generally began 2 days after mating but was delayed when females mated within 2 days post-eclosion. In laboratory olfactometer assays, the age of females used as odor sources and the age of males assayed to these odors did not affect sex attraction, with both younger （1-4-day-old） and older （8-10-day-old） males being attracted to females, regardless of female age （1-4-day-old or 8-10-day-old）. Males assayed to live females at different times during the photophase （between 8：00 and 20：00 hours） were attracted to females between 11：00 and 17：00 hours, showing a temporal periodicity in sex attraction with B. cockerelli at least during the photophase.

关键词： mate attraction olfactometer oviposition periodicity potato preference,Triozidae

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Nonlocal-Means Image Denoising Technique Using Robust M-Estimator

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j.urnal of Computer Science & Technology 2010年第3期25卷 623-631页

作者： Dinesh j. peter V. K. Govindan Abraham T. Mathew Department of Computer Science National Institute of Technology Calicut Department of Electrical Engineering National Institute of Technology Calicut

Edge preserved smoothing techniques have gained importance for the purpose of image processing applications A good edge preserving filter is given by nonlocal-means filter rather than any other linear model based approaches. This paper explores a different approach of nonlocal-means filter by using robust M-estimator function rather than the exponential function for its weight calculation. Here the filter output at each pixel is the weighted average of pixels with surrounding neighborhoods using the chosen robust M-estimator function. The main direction of this paper is to identify the best robust M-estimator function for nonlocal-means denoising algorithm. In order to speed up the computation, a new patch classification method is followed to eliminate the uncorrelated patches from the weighted averaging process. This patch classification approach compares favorably to existing techniques in respect of quality versus computational time. Validations using standard test images and brain atlas images have been analyzed and the results were compared with the other known methods. It is seen that there is reason to believe that the proposed refined technique has some notable points.

关键词： image processing denoising technique nonlocal-means filter robust M-estimators

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Early Warning Smartphone Diagnostics for Water Security and Analysis Using Real-Time pH Mapping

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Photonic Sensors 2015年第4期5卷 289-297页

作者： Md. Arafat HOSSAIN j.hn CANNING Sandra AST peter j. RUTLEDGE Abbas j.MALIPOUR interdisciplinary Photonics Laboratories (iPL) School of Chemistry The University of Sydney NSW 2006 Australia School of Chemistry The University of Sydney NSW 2006 Australia Wireless Networking Group (WING) School of Electrical and Information Engineering The University of Sydney NSW2006 Australia

Early detection of environmental disruption, unintentional or otherwise, is increasingly desired to ensure hazard minimization in many settings. Here, using a field-portable, smartphone fluorimeter to assess water quality based on the pH response of a designer probe, a map of pH of public tap water sites has been obtained. A custom designed Android application digitally processed and mapped the results utilizing the global positioning system （GPS） service of the smartphone. The map generated indicates no disruption in pH for all sites measured, and all the data are assessed to fall inside the upper limit of local government regulations, consistent with authority reported measurements. This implementation demonstrates a new security concept： network environmental forensics utilizing the potential of novel smartgrid analysis with wireless sensors for the detection of potential disruption to water quality at any point in the city. This concept is applicable across all smartgrid strategies within the next generation of the Internet of Things and can be extended on national and global scales to address a range of target analytes, both chemical and biological.

关键词： Lab-in-a-phone Intemet of Things optical sensing and sensor smartphone sensor photonic sensor fluorescence water security

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Control of Cell Wall Extensibility during Pollen Tube Growth

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Molecular Plant 2013年第4期6卷 998-1017页

作者： peter K. Hepler Caleb M. Rounds Lawrence j. Winship Biology Department University of Massachusetts Amherst MA 01003 USA School of Natural Science Hampshire College Amherst MA 01002 USA

In this review, we address the question of how the tip-growing pollen tube achieves its rapid rate of elongation while maintaining an intact cell wall. Although turgor is essential for growth to occur, the local expansion rate is controlled by local changes in the viscosity of the apical wall. We focus on several different structures and underly- ing processes that are thought to be maj.r participants including exocytosis, the organization and activity of the actin cytoskeleton, calcium and proton physiology, and cellular energetics. We think that the actin cytoskeleton, in particular the apical cortical actin fringe, directs the flow of vesicles to the apical domain, where they fuse with the plasma mem- brane and contribute their contents to the expanding cell wall. While pH gradients, as generated by a proton-ATPase located on the plasma membrane along the side of the clear zone, may regulate rapid actin turnover and new polymeri- zation in the fringe, the tip-focused calcium gradient biases secretion towards the polar axis. The recent data showing that exocytosis of new wall material precedes and predicts the process of cell elongation provide support for the idea that the intussusception of newly secreted pectin contributes to decreases in apical wall viscosity and to cell expansion. Other prime factors will be the localization and activity of the enzyme pectin methyl-esterase, and the chelation of calcium by pectic acids. Finally, we acknowledge a role for reactive oxygen species in the control of wall viscosity.

关键词： cell expansion cell walls cytoskeleton dynamics polarity pollen development.

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The Sulfate Transporter Family in Wheat： Tissue-Specific Gene Expression in Relation to Nutrition

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Molecular Plant 2010年第2期3卷 374-389页

作者： peter Buchner Saroj.Parmar Anne Kriegel Magali Carpentier Malcolm j. Hawkesford Rothamsted Research Plant Science Department West Common Harpenden Hertfordshire AL5 2JQ UK Molecular Plant Nutrition University of Hohenheim Stuttgart Germany

Sulfate uptake and distribution in plants are managed by the differential expression of a family of transporters, developmentally, spatially, and in response to sulfur nutrition. Elucidation of the signaling pathways involved requires a knowledge of the component parts and their interactions. Here, the expression patterns of the full complement of sulfate transporters in wheat, as influenced by development and sulfur nutrition, are described. The 10 wheat sulfate transporters characterized here are compared to the gene families for both rice and Brachypodium, for whom full genome information is available. Expression is reported in young seedlings with a focus on roles in uptake from nutrient solution and differential expression in relation to sulfate deprivation. In addition, patterns of expression in all organs at the grain filling stage are reported and indicate differential responses to nutritional signals of the individual transporters in specific tissues and an overall coordination of uptake, storage, and remobilization to deliver sulfur to the developing grain.

关键词： Sulfate transporter wheat transcriptional regulation sulfur nutrition grain filling.

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Growth factor receptor trafficking as a potential therapeutic target in pediatric cancer

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Frontiers in Biology 2012年第1期7卷 1-13页

作者： peter E. ZAGE Andrew j. BEAN Department of Pediatrics Section of Hematology-Oncology 1102 Bates Suite 1220 Houston TX 77030 USA Texas Children＇s Cancer and Hematology Centers Houston TX 77030 USA Dan L. Duncan Cancer Center Baylor College of Medicine Houston TX 77030 USA Department of Neurobiology and Anatomy The University of Texas Health Science Center at Houston Houston TX 77030 USA Division of Pediatrics The University of Texas M.D. Anderson Cancer Center Houston TX 77030 USA

Growth factor receptors （GFRs） are often aberrantly expressed in tumor cells, and altered GFR expressionand activity contribute to the pathogenesis of many types of cancer. A variety of mechanisms have been identified that result in enhanced GFR expression and activity in cancer cells. Defects in the pathways responsible for GFR internalization and intraceilular trafficking are likely to be involved in altered GFR expression in a variety of cancers. The roles of GFR trafficking pathways in the regulation of GFR expression, in the pathogenesis of tumors, and in the response of tumors to treatment have not been fully delineated, but the likely contributions of GFR signaling to the development and progression of various malignancies suggest that therapies that modify GFR trafficking may be effective as anticancer treatments. The intraceHular trafficking of GFRs is regulated by a number of protein complexes and by protein ubiquitination. Many of the proteins required for this trafficking are products of tumor suppressor genes, and the expression and function of the protein machinery utilized for intracellular trafficking is frequently altered in tumor cells, consistent with the likely role of GFR trafficking in tumorigenesis. Many of the proteins involved in GFR trafficking have been identified as potential targets for anticancer treatment, and novel treatments directed against these targets are currently in preclinical development and in clinical trials. Ubiquitin ligases are critical for GFR trafficking and represent potentially important targets for the development of novel therapies. The genes for the ubiquitin ligases c-Cbl and UBE4B are located in chromosome regions commonly altered in a variety of tumors and therefore are likely to be important for tumorigenesis, c-Cbl nbiquitinates a number of GFRs and directs them for degradation. Mutations in c-Cbl have been identified in cases of myeloid leukemia and myelodysplasia, providing a link between GFR ubiquitinatio

关键词： growth factor receptor tyrosine kinase trafficking UBE4B neuroblastoma

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Modeling and analyzing the impact of temperature and rainfall on mosquito population dynamics over Kwazulu-Natal, South Africa

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International j.urnal of Biomathematics 2017年第4期10卷 211-233页

作者： Gbenga j. Abiodun peter Witbooi Kazeem O. Okosun Department of Mathematics and Applied Mathematics University of the Western Cape Private Bag X17 Bellville 7535 Republic of South Africa Department of Mathematics Vaal University of Technology Private Bag X021 Vanderbijlpark Andries Potgieter Blvrd-1900 Republic of South Africa

Malaria parasites are strongly dependent on Anopheles mosquitoes for transmission; for this reason, mosquito population dynamics are a crucial determinant of malaria risk. However, temperature and rainfall play a significant role in both aquatic and adult stages of the Anopheles. Consequently, it is important to understand the bio- logy of malaria vector mosquitoes in the study of malaria transmission. In this study, we develop a climate-based, ordinary-differential-equation model to analyze how rain- fall and temperature determine mosquito population size. In the model, we consider in detail the influence of ambient temperature on gonotrophic and sporogonic cycles over Amaj.ba District, Kwazulu-Natal Province, South Africa. In particular, we further use the model to simulate the spatial distribution of the mosquito biting rate over the study region. Our results reflect high seasonality of the population of An. gambiae over the region and also demonstrate the influence of climatic factors on the mosquito population dynamics.

关键词： Anopheles mosquito climate basic reproduction number.

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A New Ceratopsian from the Upper j.rassic Houcheng Formation of Hebei, China

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Acta Geologica Sinica(English Edition) 2006年第4期80卷 467-473页

作者： ZHAO Xij.n CHENG Zhengwu XU Xing peter j. MAKOVICKY Institute of Vertebrate Paleontology and Paleoanthropology Chinese Academy of Sciences 142 Xizhimenwai Street Beijing 100044 China Institute of Geology Chinese Academy of Geological Sciences 26 Baiwanzhuang Road Beijing 100037 China Department of Geology The Field Museum 1400 S Lake Shore Drive Chicago IL 60605 U.S.A.

A new ceratopsian taxon Xuanhuaceratops niei gen. et sp. nov. is erected based on four fragmentary specimens collected from the Late j.rassic Houcheng Formation, Hebei Province, China. Xuanhuaceratops shares a number of derived features with, and is closely related to, another probable Late j.arassic ceratopsian Chaoyangsaurus youngi, from which it differs in only possessing a single premaxlllary tooth as well as in details of quadrate and scapular morphology. We hypothesize that these two taxa represent a primitive lineage of Ceratopsia that is basal to the psittacosauridneoceratopsian diversity, and propose the name Chaoyangsauridae for it.

关键词： Houcheng Formation j.rassic Hebei Chaoyangsauridae Ceratopsia

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