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Early osmotic adj.stment responses in drought-resistant and drought-sensitive oilseed rape

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j.urnal of Integrative Plant Biology 2014年第8期56卷 797-809页

作者： sarah Hatzig L.Irina Zaharia Suzanne Abrams Marie Hohmann Laurie Legoahec Alain Bouchereau Nathalie Nesi Rod j.Snowdon Department of Plant Breeding IFZ Research Centre for Biosystems Land Use and Nutrition Justus Liebig University National Research Council of Canada Aquatic and Crop Resource Development Department of Chemistry University of Saskatchewan UMR 1349 INRA-AgroCampus Ouest-Université de Rennes 1 Joint Laboratory for Genetics Environment and Plant Protection (IGEPP) Bat.301 BP 35327 35653 Le Rheu Cedex France

The impact of osmotic stress on growth, physiolo- gy, and metabolism of winter oilseed rape （Brassica napus L.） was investigated by detailed analysis of biomass traits, hormone metabolites and osmolytes in two genetically unrelated drought-tolerant genotypes and two unrelated drought-sensitive genotypes. Seedlings were grown in vitro under controlled conditions and osmotic stress was simulated by applying a gradual treatment with polyethylene glycol （PEG 6ooo）, followed by hypo-osmotic treatment of variants used for metabolite determination. The results provide a basis for the identification of reliable selection criteria for drought resistance in oilseed rape. The in vitro cultivation system established during this study enabled effective discrimination of early osmotic stress responses between drought-resistant and -susceptible oilseed rape genotypes that also show large differences in relative seed yield under drought conditions in the field. Clear physiological and metabolic differences wereobserved between the drought-resistant and drought-sensitive genotypes, suggesting that osmotic adj.stment is a key component of drought response in oilseed rape. Unexpected- ly, however, the drought-resistant genotypes did not show typical hormonal adj.stment and osmolyte accumulation, suggesting that they possess alternative physiological mech- anisms enabling avoidance of stress symptoms.

关键词： Abscisic acid Brassica napus drought hormones metabolites

Insect herbivory along environmental gradients

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Open j.urnal of Ecology 2012年第4期2卷 202-213页

作者： Nigel R. Andrew Isobel R. Roberts sarah j. Hill Centre for Behavioural and Physiological Ecology Zoology University of New England Armidale Australia

There is a general assumption in the literature that insect herbivory increases towards the tropics, but decreases with increasing altitude. Similar generalities have been identified along other environmental gradients, such as resource, temperature, climatic and biotic gradients. However there is growing evidence in the scientific literature that such generalities are not consistent. This could be due to a number of reasons including the lack of consistency in the way herbivory is assessed such as different methodologies used by researchers, or fundamental differences in leaf damage caused by different types of insect herbivores. Here we assess 61 publications researching insect herbivory along a range of environmental gradients (both biotic and abiotic) and review the methods that researchers have used to collected their data. We found leaf chewing from samples collected in North America dominated the field and most studies assessed herbivory on a single host plant species. Thirty three percent of the studies assessed latitudinal gradients, while 10% assessed altitudinal gradients. Insect herbivory was most commonly expressed as percentage leaf damage using point herbivory. Fewer studies measured a range of different types of herbivory (such as sap sucking, leaf mining, galling, and root feeding) as leaves aged. From our synthesis, we hope that future research into insect herbivory along environmental gradients will take into account herbivory other than j.st leaf chewing, such as sap sucking, which may cause more damage to plants. Future research should also assess herbivory as a rate, rather than j.st a single point in time as damage to a young leaf may be more costly to a plant than damage to a mature or senescing leaf. Measurements of plant traits will also assist in comparing herbivory across habitats, plant species, and within species physiological variation. The true impacts that insects have on plants via herbivory along environmental gradients are still p

关键词： Insect Herbivory Gradients Leaf Chewing Sap Sucking Galling Root Feeding

Glycogen and amyloid-beta: key players in the shift from neuronal hyperactivity to hypoactivity observed in Alzheimer's disease?

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Neural Regeneration Research 2015年第7期10卷 1023-1025页

作者： Britanny Bass sarah Upson Kamolika Roy Emily L.Montgomery Tuula O.j.lonen Ian V.j.Murray Department of Physiology and Neuroscience St.George’s University School of Medicine

Introduction：Alzheimer’s disease（AD）begins to develop decades prior to its clinical manifestation（Sperling et al.,2011）,and while it is the most common form of dementia,as of yet there is no *** of the most researched pathological features contributing to disease development are the extracellular amyloid plaques composed of amyloid-beta proteins（Aβ）and neurofibrillary tangles of tau *** feature of AD is the progression of early neuronal excitability/hyperactivity to silencing/hypoactivity（Palop and Mucke,2010）,

关键词： Glycogen and amyloid-beta key players in the shift from neuronal hyperactivity to hypoactivity observed in Alzheimer’s disease

Microbial community coalescence and nitrogen cycling in simulated mortality decomposition hotspots

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Ecological Processes 2023年第1期12卷 608-624页

作者： sarah W.Keenan Alexandra L.Emmons j.nnifer M.DeBruyn Department of Geology and Geological Engineering South Dakota School of Mines and Technology501 East St.Joseph StreetRapidSD 57701USA Department of Anthropology University of TennesseeKnoxvilleTNUSA Department of Biosystems Engineering and Soil Science University of Tennessee2506 E.J.Chapman DriveKnoxvilleTN 37996USA

Background The pulsed introduction of dead plant and animal material into soils represents one of the primary mechanisms for returning organic carbon(C)and nitrogen(N)compounds to biogeochemical *** of animal carcasses provides a high C and N resource that stimulates indigenous environmental microbial communities and introduces non-indigenous,carcass-derived microbes to the ***,the dynamics of the coalesced microbial communities,and the relative contributions of environment-and carcass-derived microbes to C and N cycling are *** test whether environment-derived,carcass-derived,or the combined microbial communities exhibited a greater influence on C and N cycling,we conducted controlled laboratory experiments that combined carcass decomposition fluids and soils to simulate carcass decomposition *** selectively sterilized the decomposition fluid and/or soil to remove microbial communities and create different combinations of environment-and carcass-derived communities and incubated the treatments under three temperatures(10,20,and 30℃).Results Carcass-derived bacteria persisted in soils in our simulated decomposition scenarios,albeit at low *** communities had higher respiration rates at 10 and 30℃ compared to soil or carcass communities ***,at higher temperatures,mixed communities had reduced diversity,but higher respiration,suggesting functional *** communities treatments also provided evidence that carcass-associated microbes may be contributing to ammonification and denitrification,but that nitrification is still primarily carried out by native soil *** Our work yields insight into the dynamics of microbial communities that are coalescing during carcass decomposition,and how they contribute to recycling carcasses in terrestrial ecosystems.

关键词： Carcass decomposition Microcosm Nitrogen Carbon Biogeochemical cycling Coalescence

Growth mechanisms of Ag and Cu nanodendrites via Galvanic replacement reactions

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Progress in Natural Science:Materials International 2021年第1期31卷 141-151页

作者： j.alu Chen j.mima j.Davies Alister S.Goodfellow sarah M.D.Hall Helena G.Lancaster Xinyu Liu Cameron j.Rhodes Wuzong Zhou School of Chemistry University of St Andrews

Dendritic silver and copper crystals were produced via Galvanic replacement reactions on zinc and aluminum plates, respectively. The growth orientations of these metals were determined using electron microscopy. The results showed that a fast crystal growth associated with a high concentration of metal cations led to kinetically controlled growth along the axes of the cubic close-packed structures. However, a slow growth rate resulted in thermodynamically controlled growth along the [111] axis. The crystal growth was not found to rely upon the direct deposition of metal cations at crystallographic sites on crystal facets, but instead, hydrated metal cations deposited on the crystal surface to form an amorphous coating layer, followed by the reduction of metal cations and crystallization at the crystal/coating interface. Twin defects and stacking faults were often observed across the whole particle and commonly observed1/3{422} diffraction spots were explained by stacking faults rather than by the possible presence of any superstructures. The present work offers evidences to claim that both the crystal growth rate and Coulomb interaction between negatively charged crystal surface and metal cations play an important role in the formation of metal dendrites in replacement reactions.

关键词： Silver nanodendrite Copper nanodendrite Electron microscopy Stacking fault Crystal growth

High-performance polymer electrolyte membranes incorporated with 2D silica nanosheets in high-temperature proton exchange membrane fuel cells

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j.urnal of Energy Chemistry 2022年第1期31卷 323-334,I0009页

作者： Zunmin Guo j.anuo Chen j.e j.ng Byun Rongsheng Cai Maria Perez-Page Madhumita Sahoo Zhaoqi j. sarah j.Haigh Stuart M.Holmes Department of Chemical Engineering and Analytical Science The University of ManchesterM139PLUnited Kingdom Department of Materials The University of ManchesterM139PLUnited Kingdom

Silica nanosheets(SN)derived from natural vermiculite(Verm)were successfully incorporated into polyethersulfone-polyvinylpyrrolidone(PES-PVP)polymer to fabricate high-temperature proton exchange membranes(HT-PEMs).The content of SN filler was varied(0.1-0.75 wt%)to study its influence on proton conductivity,power density and *** from the hydroxyl groups of SN that enable the formation of additional proton-transferring pathways,the inorganic-organic membrane displayed enhanced proton conductivity of 48.2 mS/cm and power density of 495 mW/cm^(2) at 150℃ without humidification when the content of SN is 0.25 wt%.Furthermore,exfoliated SN(E-SN)and sulfonated SN(S-SN),which were fabricated by a liquid-phase exfoliation method and silane condensation,respectively,were embedded in PES-PVP polymer matrix by a simple blending *** to the significant contribution from sulfonic groups in S-SN,the membrane with 0.25 wt%S-SN reached the highest proton conductivity of51.5 mS/cm and peak power density of 546 mW/cm^(2) at150℃,48%higher than the pristine PES-PVP *** to unaltered PES-PVP membrane,SN added hybrid composite membrane demonstrated excellent durability for the fuel cell at 150℃.Using a facile method to prepare 2D SN from natural clay minerals,the strategy of exfoliation and functionalization of SN can be potentially used in the production of HT-PEMs.

关键词： Silica nanosheets Vermiculite High-temperature proton exchange membrane Proton conductivity

Tomato fruit as a model for tissue-specific gene silencing in crop plants

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Horticulture Research 2020年第1期7卷 839-845页

作者： Ari Feder sarah j.nsen Anquan Wang Lance Courtney Lesley Middleton j.yce Van Eck Yongsheng Liu j.mes j.Giovannoni Boyce Thompson Institute for Plant Research Cornell UniversityIthacaNYUSA Section of Plant Breeding and Genetics Cornell UniversityIthacaNYUSA School of Biotechnology and Food Engineering Hefei University of Technology230009 HefeiChina Section of Plant Biology Cornell UniversityIthacaNYUSA US Department of Agriculture–Agricultural Research Service Robert W.Holley Center for Agriculture and HealthIthacaNYUSA

Use of CRISPR-Cas9(Clustered Regularly Interspaced Short Palindromic Repeats(CRISPR)-CRISPR-associated 9)-mediated genome editing has proliferated for use in numerous plant species to modify gene function and expression,usually in the context of either transient or stably inherited genetic *** extremely useful in many applications,modification of some loci yields outcomes detrimental to further experimental evaluation or viability of the target *** of Cas9 under a promoter conferring gene knockouts in a tissue-specific subset of genomes has been demonstrated in insect and animal models,and recently in *** developed an in planta GFP(green fluorescent protein)assay system to demonstrate fruit-specific gene editing in tomato using a phosphoenolpyruvate carboxylase 2 gene *** then targeted a SET-domain containing polycomb protein,SlEZ2,previously shown to yield pleiotropic phenotypes when targeted via ^(35)S-driven RNA interference and we were able to characterize fruit phenotypes absent additional developmental ***-specific gene editing will have applications in assessing function of essential genes otherwise difficult to study via germline modifications and will provide routes to edited genomes in tissues that could not otherwise be recovered when their germline modification perturbs their normal development.

关键词： otherwise specific editing

Randomized controlled trials in frontotemporal dementia: cognitive and behavioral outcomes

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Translational Neurodegeneration 2014年第1期3卷 89-97页

作者： j.stin B Miller sarah j.Banks Gabriel C Léger j.ffrey L Cummings Cleveland Clinic Lou Ruvo Center for Brain Health888 W.Bonneville AveLas VegasNevada 89106USA

Progress has been made in understanding the genetics and molecular biology of frontotemporal dementia(FTD).Targets for intervention have been identified,therapies are being developed,and clinical trials are advancing.A maj.r challenge for FTD research is that multiple underlying pathologies can be associated with heterogeneous *** neuropsychological profiles associated with FTD spectrum disorders often include executive dysfunction,language impairments and behavioral *** variant FTD is characterized by an initial presentation of changes in personality,behavior and/or emotion,which are often difficult to obj.ctively capture using traditional neuropsychological *** two principal language variants of FTD are Progressive Nonfluent Aphasia(PNFA)with predominant agrammatic/non-fluent impairments and Semantic Dementia(SD)with semantic impairments and visual *** of appropriate endpoints for clinical trials is critical to ensure that the measures are adequately sensitive to detect change,yet specific enough to isolate signal from noise,and acceptable to regulatory *** the anticipated potential for small effect sizes,measures must be able to identify small incremental changes over *** is also imperative that the measures provide adequate coverage of the constructs or behaviors of *** outcome measures should be suitable for repeat administration,yet relatively robust to practice effects to ensure that observed changes reflect true signal variance and not residual effects due to repeated measurement or poor *** facilitate widespread adoption as an endpoint,measures should be readily *** provide several examples of potential global,composite,and individual cognitive measures,as well as behavioral measures promising for FTD *** and application of appropriate trial outcomes is critically important to success in advancing new treatments for FTD patients.

关键词： Frontotemporal dementia Primary endpoints Secondary endpoints Randomized controlled trial Methods

The nucleolus as a genomic safe harbor for strong gene expression in Nannochloropsis oceanica

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Molecular Plant 2022年第2期15卷 340-353页

作者： Christian Südfeld Ana Pozo-Rodríguez Sara A.Manj.vacas Díez RenéH.Wij.fels Maria j.Barbosa sarah D'Adamo Wageningen University Bioprocess EngineeringPO Box 166700 AA WageningenNetherlands Faculty of Biosciences and Aquaculture Nord University8049 BodøNorway

Microalgae are used in food and feed,and they are considered a potential feedstock for sustainably pro-duced chemicals and ***,production of microalgal-derived chemicals is not yet economically *** engineering could bridge the gap to industrial application and facilitate the production of novel products from ***,we report the discovery of a novel gene expression system in the oleaginous microalga Nannochloropsis that exploits the highly efficient transcriptional activity of RNA po-lymerase I and an internal ribosome entry site for *** identified the nucleolus as a genomic safe harbor for Pol I transcription and used it to construct transformant strains with consistently strong trans-gene *** new expression system provides an outstanding tool for genetic and metabolic en-gineering of microalgae and thus will probably make substantial contributions to microalgal research.

关键词： Nannochloropsis gene expression nucleolus RNA polymerase I IRES aIRES