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Identification of Differentially Senescing mutants of Wheat and Impacts on Yield,Biomass and Nitrogen Partitioning

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Journal of Integrative Plant Biology 2012年第8期54卷 555-566页

作者： Adinda P.Derkx simon Orford simon Griffiths m.John Foulkes malcolm J. Hawkesford Plant Biology and Crop Science Department Rothamsted ResearchHarpendenHertfordshireAL5 2JQUK Division of Plant&Crop Sciences School of BiosciencesUniversity of NottinghamSutton Bonington CampusNr LoughboroughLE12 5RDUK John Innes Centre Norwich Research ParkColneyNorwich NR4 7UHUK

Increasing photosynthetic capacity by extending canopy longevity during grain filling using slow senescing stay-green genotypes is a possible means to improve yield in wheat. Ethyl methanesulfonate （EmS） mutated wheat lines （Triticum aestivum L. cv. Paragon） were screened for fast and slow canopy senescence to investigate the impact on yield and nitrogen partitioning. Stay-green and fast-senescing lines with similar anthesis dates were characterised in detail. Delayed senescence was only apparent at higher nitrogen supply with low nitrogen supply enhancing the rate of senescence in all lines. In the stay-green line 3 （SG3）, on a whole plant basis, tiller and seed number increased whilst thousand grain weight （TGW） decreased; although a greater N uptake was observed in the main tiller, yield was not affected. In fast-senescing line 2 （FS2）, yield decreased, principally as a result of decreased TGW. Analysis of N-partitioning in the main stem indicated that although the slow-senescing line had lower biomass and consequently less nitrogen in all plant parts, the proportion of biomass and nitrogen in the flag leaf was greater at anthesis compared to the other lines; this contributed to the grain N and yield of the slow-senescing line at maturity in both the main tiller and in the whole plant. A field trial confirmed senescence patterns of the two lines, and the negative impact on yield for FS2 and a positive impact for SG3 at low N only. The lack of increased yield in the slow-senescing line was likely due to decreased biomass and additionally a possible sink limitation.

关键词： Wheat senescence stay-green grain-filling yield nitrogen.

The Clock Protein CCA1 and the bZIP Transcription Factor HY5 Physically Interact to Regulate Gene Expression in Arabidopsis

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molecular Plant 2008年第1期1卷 58-67页

作者： Christos Andronis simon Barak Stephen m. Knowles Shoji Sugano Elaine m. Tobin Department of molecular Cell and Developmental Biology University of California Los Angeles CA 90095-1606 USA

The circadian clock regulates the expression of an array of Arabidopsis genes such as those encoding the LIGHT-HARVESTING CHLOROPHYLL A/B （Lhcb） proteins. We have previously studied the promoters of two of these Arabidopsis genes-Lhcb1＊1 and Lhcb1＊3m-and identified a sequence that binds the clock protein CIRCADIAN CLOCK ASSOCIATED 1 （CCA1）. This sequence, designated CCAl-binding site （CBS）, is necessary for phytochrome and circadian responsiveness of these genes. In close proximity to this sequence, there exists a G-box core element that has been shown to bind the bZIP transcription factor HY5 in other light-regulated plant promoters. In the present study, we examined the importance of the interaction of transcription factors binding the CBS and the G-box core element in the control of normal circadian rhythmic expression of Lhcb genes. Our results show that HY5 is able to specifically bind the G-box element in the Lhcb promoters and that CCA1 can alter the binding activity of HY5. We further show that CCA1 and HY5 can physically interact and that they can act synergistically on transcription in a yeast reporter gene assay. An absence of HY5 leads to a shorter period of Lhcbl＊l circadian expression but does not affect the circadian expression of CATALASE3 （CAT3）, whose promoter lacks a G-box element. Our results suggest that interaction of the HY5 and CCA1 proteins on Lhcb promoters is necessary for normal circadian expression of the Lhcb genes.

关键词： CCA1 bZIP Transcription Factor HY5 Physically Gene Expression in Arabidopsis

Adult neurogenesis in the mammalian brain

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Frontiers in Biology 2013年第3期8卷 295-304页

作者： simon m.G. BRAUN Sebastian JESSBERGER Brain Research Institute Faculty of Medicine University of Zurich 8057 Zurich Switzerland Neuroscience Center Zurich University of Zurich and ETH Zurich Switzerland

New neurons are generated throughout life in distinct areas of the mammalian brain. This process, called adult neurogenesis, has challenged previously held concepts about adult brain plasticity and opened novel therapeutic avenues to treat certain neuro-psychiatric diseases. Here, we review the current knowledge regarding the fate and potency of neural stem cells （NSCs）, as well as the mechanisms underlying neuronal differentiation and subsequent integration. Furthermore, we discuss the functional significance of adult neurogenesis in health and disease, and offer brief insight into the future directions of the adult neurogenesis field.

关键词： adult neurogenesis hippocampus stem cell memory neuropsychiatric disease

Reconstructing seafloor age distributions in lost ocean basins

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Geoscience Frontiers 2021年第2期12卷 769-780页

作者： simon Williams Nicky m.Wright John Cannon Nicolas Flament R.Dietmar müller Department of Geology Northwest UniversityXi’an710069China State Key Laboratory of Continental Dynamics Northwest UniversityXi’an710069China Research School of Earth Sciences The Australian National UniversityACT2601Australia ARC Centre of Excellence for Climate Extremes The Australian National UniversityACT2601Australia EarthByte Group School of GeosciencesUniversity of SydneyAustralia GeoQuEST Research Centre School of EarthAtmospheric and Life SciencesUniversity of WollongongNorthfields AvenueNSW2522Australia

Reconstructions of past seafloor age make it possible to quantify how plate tectonic forces,surface heat flow,ocean basin volume and global sea level have varied through geological ***,past ocean basins that have now been subducted cannot be uniquely reconstructed,and a significant challenge is how to explore a wide range of possible ***,we investigate possible distributions of seafloor ages from the late Paleozoic to present using published full-plate reconstructions and a new,efficient seafloor age reconstruction workflow,all developed using the open-source software *** test alternative reconstruction models and examine the influence of assumed spreading rates within the Panthalassa Ocean on the reconstructed history of mean seafloor age,oceanic heat flow,and the contribution of ocean basin volume to global sea *** reconstructions suggest variations in mean seafloor age of~15 myr during the late Paleozoic,similar to the amplitude of variations previously proposed for the Cretaceous to *** reconstructed oceanic age-area distributions are broadly compatible with a scenario in which the long-period fluctuations in global sea level since the late Paleozoic are largely driven by changes in mean seafloor *** suggestions of a constant rate of seafloor production through time can be modelled using our workflow,but require that oceanic plates in the Paleozoic move slower than continents based on current reconstructions of continental motion,which is difficult to reconcile with geodynamic studies.

关键词： Plate reconstructions Sea level Seafloor spreading

modelling surface runoff using the soil conservation service-curve number method in a drought prone agro-ecological zone in Rwanda

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International Soil and Water Conservation Research 2019年第1期7卷 9-17页

作者： Dieudonne Uwizeyimana Stephen m.mureithi simon m.mvuyekure George Karuku Geoffrey Kironchi Department of Land Resource management and Agricultural Technology University of NairobiP.O Box 2905300625 NairobiKenya ministry of Agriculture and Animal Resources of Rwanda P.O.Box 6961KigaliRwanda Rwanda Agriculture and Animal Resources Development Board P.O.Box 5016KigaliRwanda

Runoff farming is reported to improve land productivity and crop yields in hot and dry *** study was conducted to assess the available rainwater that can be harvested in a conserved catchment in a drought prone agro-ecological *** study was carried out in the Cyili sub-catchment,southern province of Rwanda,which has an irregular rainfall pattern and unexploited runoff *** Conservation Service-Curve Number method (SCS-CN),CROPWAT model version 8 and Hazen model with an average daily rainfall data recorded from 1971 to 2016 were applied to estimate the runoff and water requirements in the study *** of the study revealed that more than half rainfall water received in the catchment was lost through runoff (229.8 mm) and effective rainfall was lower (246.9 mm) than the actual crop water requirement for maize (330 mm).The expected seasonal surface runoff volume to be harvested by the farmers was 3008 m3 ha-1 per season and 1.29 × 106 m3 per season for the entire whole sub-catchment (430 ha).Based on Hazen model,the return period of low rainfall (dry spell) event would be expected every 2 years with a 98% probability of *** sub-catchment has higher potential runoff volume to stabilize the deficit of water demand in the period of short rainy *** suggests that rainwater harvesting through supplementary irrigation is an option to improve the crop yield in the dry period as well as in the annual dry season.

关键词： Available rainwater Cyili sub-Catchment Curve number Runoff Rwanda

Does laser surface texturing really have a negative impact on the fatigue lifetime of mechanical components?

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Friction 2021年第6期9卷 1766-1775页

作者： Chia-Jui HSU Andreas STRATmANN simon mEDINA Georg JACOBS Frank mÜCKLICH Carsten GACHOT Institute for Engineering Design and Product Development TU WienLehárgasse 6Campus GetreidemarktVienna 1060Austria Chair of Functional materials Saarland UniversityCampus D3.3Saarbrücken 66123Germany AC2T Research GmbH Viktor-Kaplan-Straße 2/CWiener Neustadt 2700Austria Institute for machine Elements and Systems Engineering RWTH AachenSchinkelstraße 10Aachen 52062Germany

Laser surface texturing(LST)has been proven to improve the tribological performance of machine *** micro-scale patterns manufactured by LST may act as lubricant reservoirs,thus supplying oil when encountering insufficient ***,not many studies have investigated the use of LST in the boundary lubrication regime,likely due to concerns of higher contact stresses that can occur with the increasing surface *** study aims to examine the influence of LST on the fatigue lifetime of thrust rolling bearings under boundary lubrication.A series of periodic patterns were produced on the thrust rolling bearings,using two geometrically different designs,namely cross and dimple *** oil ISO VG 100 mixed with 0.05 wt%P of zinc dialkyldithiophosphate(ZDDP)was *** bearings with cross patterns reduce the wear loss by two orders of *** patterns not only retain lubricant in the textured pockets but also enhance the formation of an anti-wear *** tribofilm generation may be improved by the higher contact stresses that occur when using the textured ***,in contrast to the negative concerns,the ball bearings with cross patterns were instead found to increase the fatigue life by a factor of three.

关键词： thrust rolling bearing laser surface texturing direct laser interference patterning zinc dialkyldithiophosphate(ZDDP) tribofilm

Identifying high-risk over-entitlement in access control policies using fuzzy logic

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Cybersecurity 2022年第2期5卷 75-91页

作者： simon Parkinson Saad Khana Department of Computer Science University of HuddersfieldHuddersfieldHD13DHUK

Analysing access control policies is an essential process for ensuring over-prescribed permissions are identified and removed. This is a time-consuming and knowledge-intensive process, largely because there is a wealth of policy information that needs to be manually examined. Furthermore, there is no standard definition of what constitutes an over-entitled permission within an organisation’s access control policy, making it not possible to develop automated rule-based approaches. It is often the case that over-entitled permissions are subjective to an organisation’s role-based structure, where access is be divided and managed based on different employee needs. In this context, an irregular permission could be one where an employee has frequently changed roles, thus accumulating a wide-ranging set of permissions. There is no one size fits all approach to identifying permissions where an employee is receiving more permission than is necessary, and it is necessary to examine them in the context of the organisation to establish their individual risk. Risk is not a binary measure and, in this work, an approach is built using Fuzzy Logic to determine an overall risk rating, which can then be used to make a more informed decision as to whether a user is over-entitled and presenting risk to the organisation. This requires the exploratory use of establishing resource sensitivity and user trust as measures to determine a risk rating. The paper presents a generic solution, which has been implemented to perform experimental analysis on microsoft’s New Technology File System to show how this works in practice. A simulation using expert knowledge for comparison is then performed to demonstrate how effective it is at helping the user identify potential irregular permissions.

关键词： Fuzzy control Fuzzy systems Security Access control policies Security analysis Risk Fuzzy logic Risk-adaptive access control

Effect of different surface treatments on bioactivity of porous titanium implants

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Journal of materials Science & Technology 2019年第3期35卷 418-426页

作者： m.Todea A.Vulpoi C.Popa P.Berce S.simon Institute of Interdisciplinary Research in Bio-Nano-Sciences Babes Bolyai University Department of molecular Sciences Faculty of Medicine Iuliu Hatieganu University of Medicine and Pharmacy Technical University of Cluj-Napoca Faculty of Materials Science and Engineering Department of Materials Science and Technology Technical University of Cluj-Napoca Faculty of Machine Building & National Centre of Rapid Prototyping

The work aims to characterize the structure and to evaluate in vitro the effect of different surface treatments on the bioactivity of medical grade Ti6Al7 Nb alloy implants manufactured by selective laser melting. In order to improve the bioactivity of these samples, they were subjected to heat treatment,chemical treatment, and impregnation with bioactive materials. To evaluate the apatite forming ability, the samples were immersed in simulated body fluid solution) and characterized before and after immersion by scanning electron microscopy, X-ray diffraction and X-ray photoelectron *** composition and the texture of the surfaces after the applied treatments have a selective effect on apatite layer development on the surface of samples.

关键词： Ti6Al7Nb alloy Laser processing Composite materials Surface properties Bioactivity

Characterization of colonic dendritic cells in normal and colitic mice

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World Journal of Gastroenterology 2005年第40期11卷 6338-6347页

作者： Sheena m Cruickshank Nicholas R English Peter J Felsburg simon R Carding Institute of molecular and Cellular Biology Antigen Presentation Research Group Department of Clinical Science

AIm： Recent studies demonstrating the direct involvement of dendritic cells （DC） in the activation of pathogenic T cells in animal models of inflammatory bowel disease identify DC as important antigen presenting cells in the colon. However, very little is known about the properties of colonic DC. mETHODS： Using immunohistochemistry, electron microscopy and flow cytometry we have characterized and compared colonic DC in the colon of healthy animals and interleukin-2-deficient （IL2-/-） mice that develop colitis. RESULTS： In the healthy colon, DC resided within the lamina propria and in close association with the basement membrane of colonic villi. Type i myeloid （CD11c^＋, CD11b^＋, B220, CD8） DC made up the largest （40-45%） population and all DC expressed low levels of CD80, CD86, and CD40, and had high endooltic activity consistent with an immature phenotype. In colitic IL2-/- mice, colonic DC numbers increased four- to five-fold and were localized within the epithelial layer and within aggregates of T and B cells. They were also many more DC in mesenteric lymph nodes （mLN）. The majority （〉85%） of DC in the colon and mLN of IL2./ mice were type 1 myeloid, and expressed high levels of mHC class II, CD80, CD86, CD40, DEC 205, and CCR5 molecules and were of low endocytic activity consistent with mature DC. CONCLUSION： These findings demonstrate striking changes in the number, distribution and phenotype of DC in the inflamed colon. Their intimate association with lymphocytes in the colon and draining lymph nodes suggest that they may contribute directly to the ongoing inflammation in the colon.

关键词： Colonic dendritic cells Interleukin 2 Colitis