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Mitogen-activated protein kinases mediate the oxidative burst and saponin synthesis induced by chitosan in cell cultures of Panax ginseng

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Science China(Life Sciences) 2004年第4期47卷 303-312页

作者： Steven j. NEILL Centre for Research in Plant Science University of the West of England Bristol Coldharbour Lane Bristol BS16 1QY United Kingdom

Chitosan (CHN) specially induced the activities of 39 kD and 42 kD protein kinases in ginseng cells, which could be suppressed by an inhibitor of mitogen-activated protein kinase (MAPK) pathway, PD98059. The immunoprecipitation (IP) using MAPK antibody or kinase assay in vitro also showed that CHN-induced 42 kD and 39 kD protein kinases belonged to the MAPK family. PD98059 suppressed CHN-induced transcriptions of ginseng squalene synthase and ginseng squalene epoxidase genes (gss and gse), CHN-induced accumulation of β-Amyrin synthase (β-AS) and synthesis of saponin. These results showed that CHN-induced activities of MAPKs were necessary for the CHN-induced saponin synthesis. EGTA and LaCl3 suppressed CHN-induced 39 kD and 42 kD MAPK activities. Ruthenium red (RR) could suppress CHN-induced 39 kD activity. All of them suppressed CHN-induced saponin synthesis. These results indicated that CHN-induced increment of cytosolic calcium was necessary for CHN-induced saponin synthesis. PD98059 also suppressed CHN-induced oxidative burst (including the increment of activity of plasma membrane NADPH oxidase and production of H2O2), but diphenylene iodonium (DPI), dimethylthiourea (DMTU) and 2,5-dihydroxycinnamic acid methyl ester (DHC) could not suppress CHN-induced MAPK activities, which indicated that MAPK was possibly function upstream of CHN-induced oxidative burst. Keywords mitogen-activated protein kinase - chitosan - saponin

关键词： mitogen-activated protein kinase,chitosan,saponin.

An assessment of African lion Panthera leo sociality via social network analysis： prerelease monitoring for an ex situ reintroduction program

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Current Zoology 2017年第3期63卷 301-311页

作者： Emma j. DUNSTON j.ckie ABEL Rebecca E. DOYLE j.cqui KIRK Victoria B. HILLEY andrew FORSYTH Emma j.NKINS Rafael FREIRE School of Animal and Veterinary Sciences Charles Sturt University Wagga Wagga NSW 2678 Australia Social and Conservation Psycology Coventry University Coventry CV1 5FB UK African Lion & Environmental Research Trust Melrose Farm Livingstone 23345 Zambia Animal Welfare Science Centre The University of Melbourne Parkville Victoria 3010 Australia African Lion & Environmental Research Trust Antelope Park Gweru Midlands Zimbabwe Siyafunda The Greater Makalali Private Game Reserve Harmony 27 Hoedspruit 0895 South Africa

The wild population of the African lion Panthera leo continues to decline, requiring alternate conservation programs to be considered. One such program is ex situ reintroduction. Prior to release, longterm monitoring and assessment of behavior is required to determine whether prides and coalitions behave naturally and are sufficiently adapted to a wild environment. Social network analysis （SNA） can be used to provide insight into how the pride as a whole and individuals within it, function. Our study was conducted upon 2 captive-origin prides who are part of an ex situ reintroduction program, and 1 wild pride of African lion. Social interactions were collected at all occurrence for each pride and categorized into greet, social grooming, play, and aggression. Betweenness centrality showed that offspring in each pride were central to the play network, whereas degree indicated that adults received （indegree） the greatest number of overall social interactions, and the adult males of each pride were least likely to initiate （outdegree） any interactions. Through the assessment of individual centrality and degree values, a social keystone adult female was identified for each pride. Social network results indicated that the 2 captive-origin prides had formed cohesive social units and possessed relationships and behaviors comparable with the wild pride for the studied behaviors. This study provided the first SNA comparison between captive-bred origin and a wild pride of lions, providing valuable information on individual and pride sociality, critical for determining the success of prides within an ex situ reintroduction program.

关键词： African lion Panthera leo conservation ex situ reintroduction social interactions.

Reevaluating the conceptual framework for applied research on host-plant resistance

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Insect Science 2013年第3期20卷 263-272页

作者： Michael j. Stout Department of Entomology Louisiana State University Agricultural Center 404 Life Sciences Building Baton Rouge LA 70803 USA

Applied research on host-plant resistance to arthropod pests has been guided over the past 60 years by a framework originally developed by Reginald Painter in his 1951 book, Insect Resistance in Crop Plants. Painter divided the ＂phenomena＂ of resistance into three ＂mechanisms,＂ nonpreference （later renamed antixenosis）, antibiosis, and tolerance. The weaknesses of this framework are discussed. In particular, this trichotomous framework does not encompass all known mechanisms of resistance, and the antixenosis and antibiosis categories are ambiguous and inseparable in practice. These features have perhaps led to a simplistic approach to understanding arthropod resistance in crop plants. A dichotomous scheme is proposed as a replacement, with a maj.r division between resistance （plant traits that limit inj.ry to the plant） and tolerance （plant traits that reduce amount of yield loss per unit inj.ry）, and the resistance category subdivided into constitutive/inducible and direct/indirect subcategories. The most important benefits of adopting this dichotomous scheme are to more closely align the basic and applied literatures on plant resistance and to encourage a more mechanistic approach to studying plant resistance in crop plants. A more mechanistic approach will be needed to develop novel approaches for integrating plant resistance into pest management programs.

关键词： antibiosis antixenosis host-plant resistance integrated pest management,plant-insect interactions tolerance

A primitive confuciusornithid bird from China and its implications for early avian flight

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Science China Earth Sciences 2008年第5期51卷 625-639页

作者： Michael j. BENTON Department of Earth Sciences University of Bristol Bristol BS8 1RJ UK

Confuciusornithids, lived from 120–125 million years ago, form a basal bird group and include the oldest birds with horny beaks. Here we describe Eoconfuciusornis zhengi, gen. et sp. nov. from the Early Cretaceous Dabeigou Formatio (131 Ma) in Fengning, Hebei Province, northern China. It represents a new and, more primitive than other known, member of this group and extends the lifespan of this family to 11 Ma, the longest of any known Early Cretaceous avian lineages. Furthermore, Eoconfuciusornis and its relatives present many osteological transformations, such as the size increase of the deltopectoral crest of the humerus and the keel of the sternum, apparently an adaptation toward improved flight in the evolution of the Confuciusornithidae.

关键词： Birds Early Cretaceous confuciusornithids flight

Selfish genetic elements and the gene＇s-eye view of evolution

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Current Zoology 2016年第6期62卷 659-665页

作者： j. Arvid AGREN Department of Molecular Biology and Genetics Cornell University Ithaca NY 14853-2703 USA

During the last few decades, we have seen an explosion in the influx of details about the biology of selfish genetic elements. Ever since the early days of the field, the gene＇s-eye view of Richard Dawkins, George Williams, and others, has been instrumental to make sense of new empirical observations and to the generation of new hypotheses. However, the close association between selfish genetic elements and the gene＇s-eye view has not been without critics and several other conceptual frameworks have been suggested. In particular, proponents of multilevel selection models have used selfish genetic elements to criticize the gene＇s-eye view. Ln this paper, t first trace the intertwined histories of the study of selfish genetic elements and the gene＇s-eye view and then discuss how their association holds up when compared with other proposed frameworks. Next, using examples from transposable elements and the maj.r transitions, I argue that different models highlight separate aspects of the evolution of selfish genetic elements and that the productive way forward is to maintain a plurality of perspectives. Finally, I discuss how the empirical study of selfish genetic elements has implications for other conceptual issues associated with the gene＇seye view, such as agential thinking, adaptationism, and the role of fitness maximizing models in evolution.

关键词： hierarchy intragenomic conflict levels of selection maj.r transitions multilevel selection Richard Dawkins.

A Model System of Development Regulated by the Long-distance Transport of mRNA

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j.urnal of Integrative Plant Biology 2010年第1期52卷 40-52页

作者： David j. Hannapel Plant Biology Maj.r 253 Horticulture Hall Iowa State University

BELl-like transcription factors are ubiquitous in plants and interact with KNOTTEDI-types to regulate numerous developmental processes. In potato, the RNA of several BELl-like transcription factors has been identified in phloem cells. One of these, StBEL5, and its Knox protein partner regulate tuber formation by targeting genes that control growth. RNA detection methods and grafting experiments demonstrated that StBEL5 transcripts move across a graft union to localize in stolon tips, the site of tuber induction. This movement of RNA originates in source leaf veins and petioles and is induced by a short-day photoperiod, regulated by the untranslated regions, and correlated with enhanced tuber production. Addition of the StBEL5 untranslated regions to another *** mRNA resulted in its preferential transport to stolon tips leading to increased tuber production. Upon fusion of the untranslated regions of StBEL5 to a β-glucuronidase marker, translation in tobacco protoplasts was repressed by those constructs containing the 3＇ untranslated sequence. The untranslated regions of the StBEL5 mRNA are involved in mediating its long-distance transport and in controlling translation. The 3＇ untranslated sequence contains an abundance of conserved motifs that may serve as binding motifs for RNA-binding proteins. Because of their presence in the phloem sieve tube system, their unique untranslated region sequences and their diverse RNA accumulation patterns, the family of BEL1-like RNAs from potato represents a valuable model for studying the long-distance transport of full-length mRNAs and their role in development.

关键词： BEL A Model System of Development Regulated by the Long-distance Transport of mRNA Long

A review of refinery complexity applications

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Petroleum Science 2017年第1期14卷 167-194页

作者： Mark j. Kaiser Center for Energy Studies Louisiana State UniversityEnergy Coast and Environment Building Baton RougeLA 70803 USA

Refinery complexity quantifies the sophistication and capital intensity of a refinery and has found widespread application in facility classification, cost estimation, sales price models, and other uses. Despite the ubiquity and widespread use of refining complexity, however, surprisingly little material has been written on its applications. The pur- pose of this review is to describe the primary applications of refinery complexity and some recent extensions. A secondary purpose of this review is to provide a framework that unifies complexity applications and suggests avenues for future research. Examples illustrate the applications considered.

关键词： Cost estimation Functional complexityInverse problem Replacement cost Refineryclassification Sales price models

Biogenic production of DMSP and its degradation to DMS—their roles in the global sulfur cycle

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Science China(Life Sciences) 2019年第10期62卷 1296-1319页

作者： Xiao-Hua Zhang j. Liu j.ngli Liu Guipeng Yang Chun-Xu Xue andrew R. j. Curson j.nathan D. Todd MOE Key Laboratory of Marine Genetics and Breeding College of Marine Life SciencesOcean University of ChinaQingdao 266003China Laboratory for Marine Ecology and Environmental Science Qingdao National Laboratory for Marine Science and TechnologyQingdao 266237China College of Chemistry and Chemical Engineering Ocean University of ChinaQingdao 266071China School of Biological Sciences University of East AngliaNorwich NR4 7TJUK

Dimethyl sulfide(DMS) is the most abundant form of volatile sulfur in Earth’s oceans, and is mainly produced by the enzymatic clevage of dimethylsulfoniopropionate(DMSP). DMS and DMSP play important roles in driving the global sulfur cycle and may affect climate. DMSP is proposed to serve as an osmolyte, a grazing deterrent, a signaling molecule, an antioxidant, a cryoprotectant and/or as a sink for excess sulfur. It was long believed that only marine eukaryotes such as phytoplankton produce DMSP. However, we recently discovered that marine heterotrophic bacteria can also produce DMSP, making them a potentially important source of DMSP. At present, one prokaryotic and two eukaryotic DMSP synthesis enzymes have been *** heterotrophic bacteria are likely the maj.r degraders of DMSP, using two known pathways: demethylation and *** phytoplankton and some fungi can also cleave DMSP. So far seven different prokaryotic and one eukaryotic DMSP lyases have been identified. This review describes the global distribution pattern of DMSP and DMS, the known genes for biosynthesis and cleavage of DMSP, and the physiological and ecological functions of these important organosulfur molecules, which will improve understanding of the mechanisms of DMSP and DMS production and their roles in the environment.

关键词： marine microorganism dimethylsulfoniopropionate (DMSP) dimethyl sulfide (DMS) DMSP biosynthesis DMSP cleavage

Out-of-core clustering of volumetric datasets

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j.urnal of Zhej.ang University-Science A(Applied Physics & Engineering) 2006年第7期7卷 1134-1140页

作者： GRANBERG Carl j. Department of Computing Curtin University of Technology Perth Australia

In this paper we present a novel method for dividing and clustering large volumetric scalar out-of-core datasets. This work is based on the Ordered Cluster Binary Tree (OCBT) structure created using a top-down or divisive clustering method. The OCBT structure allows fast and efficient sub volume queries to be made in combination with level of detail (LOD) queries of the tree. The initial partitioning of the large out-of-core dataset is done by using non-axis aligned planes calculated using Principal Component Analysis (PCA). A hybrid OCBT structure is also proposed where an in-core cluster binary tree is combined with a large out-of-core file.

关键词： Out-of-core clustering Hybrid rendering Scientific visualization