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Ribozymes and the mechanisms that underlie RNA catalysis

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Frontiers of Chemical Science and Engineering 2016年第2期10卷 178-185页

作者： Timothy j. Wilson Yijin Liu david M. j. Lilley Cancer Research UK Nucleic Acid Structure Research Group MSI/WTB Complex The University of Dundee Dundee DD1 5EH UK

Ribozymes are widespread, and catalyze some extremely important reactions in the cell. Mechanistically most fall into one of two classes, using either metal ions or general acid-base catalysis. The nucleolytic ribozymes fall into the latter class, mostly using nucleobases. A sub-set of these use a combination of guanine base plus adenine acid to catalyze the cleavage reaction. New ribozymes are still being discovered at regular intervals and we can speculate on the potential existence of ribozymes that catalyze chemistry beyond phosphoryl transfer reactions, perhaps using small-molecule coenzymes.

关键词： RNA catalysis RNA structure catalytic mechanism

Agroecological management of a soil-dwelling orthopteran pest in vineyards

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Insect Science 2018年第3期25卷 475-486页

作者： jerry Asalma Nboyine Stephane Boyer david j. Saville Stephen david Wratten Bio-Protection Research Centre Lincoln University Christchurch New Zealand CSIR Savanna Agriculture Research Institute Tamale Ghana Environmental and Animal Sciences Unitec Institute of Technology Auckland New Zealand Saville Statistical Consulting Limited Lincoln New Zealand

The efficacy of different combinations of undervine and inter-row treatments for managing a soil-dwelling orthopteran pest, weta （Hemiandrus sp.）, in vineyards was investigated over 2 seasons. This insect damages vine buds, thus reducing subsequent grape yield. The undervine treatments comprised pea straw mulch, mussel shells, tick beans [Viciafaba Linn. var minor （Fab）], plastic sleeves on vine trunks （treated control） and control （no intervention）, while inter-rows contained either the existing vegetation or tick beans. Treatments were arranged in a randomized complete block design with 10 replicates. Data were collected on weta densities, damage to beans and components of yield. The latter were numbers of bud laid down per vine, shoots per bud, clusters per shoot, grape bunches per vine, bunch weight and yield. The undervine treatments significantly affected all variables except the number of shoots per bud. In contrast, none of the variables was significantly affected by the inter-row treatments or their interaction with undervine treatments, apart from weta density. At the end of the experiment, weta density in the shell treatment was about 58% lower than in the control. As a result, there was about 39% significant yield increase in that treatment compared to the control. Although the undervine beans and sleeves treatments increased yield, there were no reductions in weta density. With undervine beans, the insect fed on the bean plants instead of vine buds. Thus, yield in that treatment was approximately 28% higher than in the control. These results demonstrate that simple agroecological management approaches can reduce above-ground damage by soil-dwelling insects.

关键词： cover crops grapevine yield pest management soil-dwelling insects vineyards yield loss

Search for potential K ion battery cathodes by first principles

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journal of Energy Chemistry 2021年第3期30卷 377-385页

作者： Kaining Li Xiaofeng Fan david j.Singh WTZheng Key Laboratory of Automobile Materials(jilin University) Ministry of Educationand College of Materials Science and EngineeringJilin UniversityChangchun 130012JilinChina Department of Physics and Astronomy University of MissouriColumbiaMO 65211-7010USA Department of Chemistry University of MissouriColumbiaMO 65211USA State Key Laboratory of Automotive Simulation and Control Jilin UniversityChangchun 130012JilinChina

An important challenge facing K-ion batteries lies in exploring earth-abundant and safe cathode materials that can provide high capacity with high migration rate of K ***,we propose a simple and efficient method for searching potential K cathode materials with first principles *** screening is based on combinations of weight capacity,K ion occupation ratio,volume change per K,and valence *** this screening method we predicted a series of potential K ions cathodes with favorable electrochemical performance,such as K_(2)VPO_(4)CO_(3)-like structures with 1 D diffusion channels,3 D channel structures K_(2)CoSiO_(4),layered materials KCoO_(2),KCrO_(2),KVF_(4) and K_(5)V_(3)F_(14),and *** potential cathodes have small volume changes,suitable voltage,and high capacity,with small diffusion *** may be useful in K-ion batteries with high energy density and rate performance.

关键词： K ion battery Cathodes First principles calculations High capacity with high migration rate Diffusion barriers

Performance of activated carbon coated graphite bipolar electrodes on capacitive deionization method for salinity reduction

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Frontiers of Environmental Science & Engineering 2020年第6期14卷 87-96页

作者： Hossein D.Atoufi Hasti Hasheminejad david j.Lampert School of Civil and Environmental Engineering Oklahoma State UniversityStillwaterOK 74078USA Department of Civil Engineering Isfahan University of TechnologyIsfahan 84156-83111Iran

This research investigates a capacitive deionization method for salinity reduction in a batch reactor as a new approach for *** of cost and energy compared with conventional desalination methods are the significant advantages of this *** this research,experiments were performed with a pair of graphite bipolar electrodes that were coated with a one-gram activated carbon *** completing preliminary tests,the impacts of four parameters on electrical conductivity reduction,including(1)the initial concentration of feed solution,(2)the duration of the tests,(3)the applied voltage,and(4)the pH of the solution,were *** results show that the maximum efficiency of electrical conductivity reduction in this laboratory-scale reactor is about 55%.Furthermore,the effects of the initial concentration of feed solution are more significant than the other ***,using the capacitive deionization method for water desalination with low and moderate salt concentrations(i.e.,brackish water)is proposed as an affordable *** with conventional desalination methods,capacitive deionization is not only more efficient but also potentially more environmentally friendly.

关键词： Capacitive deionization(CDI) Desalination Electrical conductivity(EC) Graphite bipolar electrode Activated carbon coated(ACC)

Protecting Against Address Space Layout Randomisation (ASLR) Compromises and Return-to-Libc Attacks Using Network Intrusion Detection Systems

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International journal of Automation and computing 2011年第4期8卷 472-483页

作者： david j Day Zheng-Xu Zhao School of Computing and Mathematics University of Derby Derby UK Faculty of Information Science and Technology Shijiazhuang Tiedao University Shijiazhuang PRC

Writable XOR executable （W⊕X） and address space layout randomisation （ASLR） have elevated the understanding necessary to perpetrate buffer overflow exploits [1] . However, they have not proved to be a panacea [1 3] , and so other mechanisms, such as stack guards and prelinking, have been introduced. In this paper, we show that host-based protection still does not offer a complete solution. To demonstrate the protection inadequacies, we perform an over the network brute force return-to-libc attack against a preforking concurrent server to gain remote access to a shell. The attack defeats host protection including W⊕X and ASLR. We then demonstrate that deploying a network intrusion detection systems （NIDS） with appropriate signatures can detect this attack efficiently.

关键词： Buffer overflow stack overflow intrusion detection systems (IDS) signature rules return-to-libc attack pre-forking.

Penile reconstruction

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Asian journal of Andrology 2013年第1期15卷 16-19页

作者： Giulio Garaffa Salvatore Sansalone david j Ralph St Peter's Andrology London WIG 6B J UK Tor Vergata University Rome 00133 Italy

During the most recent years, a variety of new techniques of penile reconstruction have been described in the literature. This paper focuses on the most recent advances in male genital reconstruction after trauma, excision of benign and malignant disease, in gender reassignment surgery and aphallia with emphasis on surgical technique, cosmetic and functional outcome.

关键词： female to male transsexuals fibrosis free flaps glans reconstruction glans sculpture lichen sclerosus lymphoedema of the genitalia penile prosthesis Peyronie's disease phalloplasty scrotoplasty shaft reconstruction skin graft penile reconstruction

Effect of calcination temperature on steam reforming activity of Ni-based pyrochlore catalysts

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journal of Rare Earths 2020年第7期38卷 711-718,I0002页

作者： Daniel j.Haynes Dushyant Shekhawat david Berry Amitava Roy james j.Spivey National Energy Technology Laboratory U.S.Department of Energy3610 Collins Ferry RdMorgantownWV26507 USA Louisiana State University Cain Department of Chemical Engineering3307 Patrick Taylor HallBaton RougeLA70803USA

This work served as the second part of a study evaluating the effect of calcination temperature(700-1000℃) on Ni-based lanthanum zirconate pyrochlore catalysts for methane steam reforming.A previous study(Haynes et ***.2017(43) 16744) provided a thorough characterization of the material properties for the catalysts used here,and this study focuses on the evaluation of catalytic *** activity was assessed by two different experimental studies:the effect of reaction temperature using a temperature programmed surface reaction(TPSR),and the effect of reaction *** results demonstrate a complex interaction between the Ni particles and surface LaOx species under the methane steam reforming ***,the material calcined at the lowest temperature(700℃) possesses the highest activity and selectivity,which is attributed to smaller and more welldispersed Ni particles on the surface,and,more importantly,a lesser degree La enrichment at the *** catalysts were deactivated by steam to NiO under all conditions tested,but at certain low reaction pressure(p=0.23 MPa) conditions the materials calcined at 700-900℃ are able to completely recover equilibrium activity in-situ that is then robust and stable under both low and high reaction pressures(p=1.8 MPa) suggesting the formation of a synergistic relationship between Ni and La for syngas ***,exposure of a fresh material to high reaction pressures leads to a rapid and irreversible loss in both CH4 conversion and syngas selectivity whether in the fresh(no pretreatment),or pretreated(steam,H2 or Ar only at 800℃) form for any *** mechanism for deactivation appears to be due to the presence of LaOx species that become mobile,possibly by the formation of La-OH,and covers the active Ni particles and inhibits sites responsible for the CH4 decomposition.

关键词： Nickel Pyrochlore Methane Steam reforming Catalyst Lanthanum enrichment

In-vitro vs in-vivo Inoculation: Screening for Resistance of Australian Rice Genotypes Against Blast Fungus

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Rice science 2015年第3期22卷 132-137页

作者： Vineela CHALLAGULLA Surya BHATTARAI david j.MIDMORE Central Queensland University School of Medical and Applied Sciences

To assist with rapid screening for rice blast resistance as a precursor in a breeding program, the susceptibility to rice blast of 13 rice genotypes from Australia was evaluated in May to june 2013 using three distinct inoculation methods（spot, filter paper and standard methods） at seedling, vegetative and reproductive stages. The results revealed that the spot and filter paper inoculation methods were successful in discerning susceptibility to the rice blast disease（P ≤ 0.05）. Disease susceptibility declined significantly from the vegetative to reproductive stages. The standard method was conducted at three different stages for pot plants grown inside the mist house. However, low temperatures did not produce disease symptoms except in a few genotypes. Among the 13 rice genotypes screened, AAT9 expressed a highly resistant response, and AAT4, AAT6, AAT10, AAT11, AAT13, AAT17 and AAT18 expressed resistance at various stages. The results will be useful for selecting elite genotypes for disease tolerance where rice blast is prevalent. In addition, the resistant genotypes can serve as a gene pool used in breeding programmes to develop new resistant genotypes.

关键词： spot inoculation filter paper inoculation standard method seedling stage vegetative stage reproductive stage rice blast disease rice genotype

Mantle-derived magmas:intraplate,hot-spots and mid-ocean ridges

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Science Bulletin 2015年第22期60卷 1873-1900页

作者： david H.Green Trevor j.Falloon Earth Sciences School of Physical Sciences University of Tasmania

Primary or parental magmas act as probes to infer eruption and source temperatures for both mid-ocean ridge （MOR） and‘hot-spot＇ magmas （tholeiitic picrites）. The experimental petrogenetic constraints （＇inverse＇ experiments） argue for no significant temperature differences between them. However, there are differences in major, minor and trace elements which characterise geochemical, not thermal, anomalies beneath ‘hot-spots＇. We suggest that diapiric upwelling from interfaces （redox contrasts） between old subducted slab and normal MOR basalt source mantle is the major reason for the observed characteristics of island chain or ‘hot-spot＇ volcanism. Intraplate basalts also include widely distributed volcanic centres containing lherzolite xenoliths, i.e. mantle-derived magmas. Inverse experiments on olivine basalt, alkali oli- vine basalt, olivine basanite, olivine nephelinite, olivine melilitite and olivine leucitite （lamproite） determined liquidus phases as a function of pressure, initially under anhydrous and CO2-absent conditions. Under C- and H-absent conditions, only tholeiites to alkali olivine basalts had O1 ＋ Opx 4-Cpx as high-pressure liquidus phases. Addition of H20 accessed olivine basanites at 2.5-3 GPa, ,- 1,200 ℃, but both CO2 and H20 were necessary to obtain saturation with O1, Opx, Cpx and Ga at 2.5-3.5 GPa for olivine nephelinite and olivine melilitite. The forward and inverse experimental studies are combined to formulate a petrogenetic grid for intraplate, ‘hot-spot＇ and MOR magmatism within the plate tectonics paradigm. The asthenosphere is geochemically zoned by slow upward migration of incipient melt. The solidus and phasestabilities of lherzolite with very small water contents （〈3,000 ppm） determine the thin plate behaviour of the oceanic lithosphere and thus the Earth＇s convection in the form of plate tectonics. There is no evidence from the parental magmas of MOR and ‘hot-spots＇ to support the ＇deep mantle thermal plume＇ hypothesis. The preferr

关键词： experimentsMantle-derived magmas ·High-pressureC-H-O · Asthenosphere - Hot-spotsPlate tectonics