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A Start Point for Extracellular Nucleotide Signaling

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Molecular Plant 2014年第6期7卷 937-938页

作者： stanley J. Roux Department of Molecular Biosciences University of Texas at Austin Austin TX 78712 USA

A START POINT FOR EXTRACELLULAR NUCLEOTIDE SIGNALINGThe recent discovery of a plant receptor for extracellu- lar nucleotides, reported by Choi et al. （2014）, is a major breakthrough that had been anticipated for over a dec- ade. Plants release ATP into their extracellular matrix （ECM） during growth and when they are induced by vari- ous biotic and abiotic stimuli （Clark and Roux, 2011）. That these extracellular nucleotides would activate receptors in plants was predicted by two sets of discoveries： that low- and sub-micromolar ATP could induce increases in [Ca2＋]cyt, NO, and superoxide signaling intermediates that led to downstream growth, stomatal, and defense responses, and that these changes could be blocked by antagonists that blocked extracellular nucleotide receptors in animals （Demidchik et al., 2003; Song et al., 2006; Clark et al., 2011; Demidchik et al., 2009, 2011）. Although mammalian biolo- gists had discovered two classes of receptors for extracel- lular nucleotides （P2X and P2Y） decades ago （Burnstock, 2007）, there were no plant proteins obviously similar to these in any sequence data available. Clearly, if there were plant purinoceptors, they would be different from the mammalian receptors, and they could not be discovered by motif searches.

关键词： PLANT genes RESEARCH PLANT lectins ADENINE nucleotides NUCLEOTIDES PLANTS -- Protein receptors ADENOSINE triphosphate -- Research PLANT growth

Analysis of drying and saturating natural gypsum samples for mechanical testing

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Journal of Rock Mechanics and Geotechnical Engineering 2019年第2期11卷 219-227页

作者： Mohammadhossein Sadeghiamirshahidi stanley J.Vitton Department of Civil and Environmental Engineering Michigan Technological University

The stability of underground abandoned gypsum mines is dependent on the gypsum pillar's strength,and most abandoned mines are in a fully saturated condition. Moisture affects the strength of gypsum and is therefore commonly measured when testing rock strength. For most rocks, this is a simple task of weighing the rock's mass before and after oven-heating at a specified temperature and duration. For natural gypsum, however, this is not a straightforward process. Heating natural gypsum can result in dehydration and transformation of gypsum to hemihydrate and anhydrite, thus changing the physical characteristics of the gypsum such as its particle density which in turn affects the moisture content and strength measurements. To prevent transformation when determining the moisture content of gypsum,the American Society for Testing Materials(ASTM) recommends lowering the drying temperature from 110℃ to 60℃ . To investigate the temperature at which gypsum transforms to hemihydrate, we used a helium pycnometer to measure the particle densities of gypsum, hemihydrate and anhydrite. In this research, we suggest that a higher drying temperature of 80℃ can be used for drying gypsum without transforming gypsum to hemihydrate. Further, preparing saturated samples for mechanical testing,which is required in stability analyses of abandoned mines, is challenging due to the dissolution of gypsum when placed in water. To address this problem, we investigated the following methods to saturate gypsum cores taking into account the solubility of gypsum:(1) water immersion,(2) vacuum saturation, and(3) improved vacuum saturation. The research indicates that all the three methods are acceptable but they should be conducted using a saturated gypsum-water solution to minimize dissolution. Further, the research found that the improved vacuum saturation method saturated the test samples within 24 h, while duration of 30 h was required for the other two methods.

关键词： Gypsum-hemihydrate-anhydrite transformation Dehydration Rock core saturation Moisture content Helium pycnometer

An Example Using Improved Lefschetz Duality

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Chinese Annals of Mathematics,Series B 2017年第6期38卷 1269-1274页

作者： Pascal LAMBRECHTS Jeremy LANE Donald stanley Pascal Lambrechts Institut Mathmatique Universit de Louvain Department of Mathemtics University of Toronto Department of Mathematics and Statistics University of Regina

A theorem of Lambrechts and stanley is used to find the rational cohomology of the complement of an embedding S^(4n-1)→ S^(2n)× S^m as a module and demonstrate that it is not necessarily determined by the map induced on cohomology by the embedding, nor is it a trivial extension. This demonstrates that the theorem is an improvement on the classical Lefschetz duality.

关键词： Lefschetz duality Embedding Extension problem

Annual-perennial plant relationships and species selection for desert restoration

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Journal of Arid Land 2013年第3期5卷 298-309页

作者： Scott R ABELLA stanley D SMITH Department of Environmental and Occupational Health University of Nevada Las VegasLas VegasNevada 89154-3064USA School of Life Sciences University of Nevada Las VegasLas VegasNevada 89154-4004USA

Exotic plant invasion is a growing concern in the conservation and management of indigenous arid land ecosystems. By creating areas of ameliorated microclimates and fertile soil below their canopies, perennial plants might influence exotic annual plant invasions. We conducted a quantitative literature review of studies that compared exotic annual plant abundance among native perennial plant species and interspace （open areas） microsites in North America＇s Mojave Desert, where exotic plant invasion has corresponded with increasing extent of wildfire and broad-scale ecosystem transformation. Ten studies compared exotic annual plant abundance between inter- spaces and below a total of 36 native perennial species. These studies revealed that：（1） With few exceptions, most native perennial species supported a greater abundance of exotic annuals than interspaces, indicating overall facilitation of exotic species by native perennials. （2） Exotic species abundance varied by orders of magnitude among native perennial species, with some perennial species harboring amounts of exotics similar to interspaces. （3） Distributions of dominant exotic species varied, where Bromus rubens displayed a greater affinity for below-perennial microsites than did Schismus spp. and Erodium cicutarium that often were most abundant in interspaces. Results suggest that the degree of facilitation of exotic plants warrants consideration when selecting native perennial species for revegetation and restoration projects.

关键词： Bromus rubens exotic fertile island invasive nurse plant positive plant interaction Schismus

Mechanical properties of Michigan Basin’s gypsum before and after saturation

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Journal of Rock Mechanics and Geotechnical Engineering 2019年第4期11卷 739-748页

作者： Mohammadhossein Sadeghiamirshahidi stanley J.Vitton Department of Civil and Environmental Engineering Michigan Technological University

The stability analysis of an abandoned underground gypsum mine requires the determination of the mine pillar’s *** is especially important for flooded abandoned mines where the gypsum pillars become saturated and are subjected to dissolution after ***,mine pillars are subjected to blast vibrations that generate some level of macro- and *** samples of gypsum must,therefore,simulate these conditions as close as *** this research,the strength of gypsum is investigated in an as-received saturated condition using uniaxial compressive strength (UCS),Brazilian tensile strength (BTS) and point load index (PLI) *** scale effect was investigated and new correlations were derived to describe the effect of sample size on both UCS and BTS under dry and saturated *** of blasting on these parameters were observed and the importance of choosing the proper samples was ***,correlations were derived for both compressive and tensile strengths under dry and saturated conditions from the PLI test results,which are commonly used as a simple substitute for the indirect determination of UCS and BTS.

关键词： Uniaxial compressive strength (UCS) Brazilian tensile strength (BTS) Point load index (PLI) Scale effect Michigan Basin's gypsum

Growth Inhibition Occurs Independently of Cell Mortality in Tomato (Solanum lycopersicum) Exposed to High Cadmium Concentrations

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Journal of Integrative Plant Biology 2008年第3期50卷 300-310页

作者： Christine Delpre stanley Lutts Unitde Biologie vgtale Universitcatholique de Louvain5(Bte 13) Place Croix du Sud1348 Louvain-la-NeuveBelgium Unitde Biologie vgtale Universit catholique de Louvain5(Bte 13) Place Croix du Sud1348 Louvain-la-NeuveBelgium

In order to analyze the adaptation potential of tomato shoots to a sudden increase in Cd concentration, tomato plants （Solanum lycopersicum L. var. Ailsa Craig） were exposed under controlled environmental conditions to a high dose of this heavy metal （250 μm CdCl2） in nutrient solution for 7 and 14d. Both root and shoot growth was completely inhibited but all plants remained alive until the end of the treatment. Cell viability remained unaffected but the activity of the mitochondrial alternative pathway was stimulated by Cd stress at the expense of the cytochrome pathway. Cadmium concentration was higher in roots than in shoots and a decrease in the rate of net Cd translocation was noticed during the second week of stress. Cadmium decreased both leaf conductance （gl） and chlorophyll concentration. However, the effect on net CO2 assimilation remained limited and soluble sugars accumulated in leaves. Photochemical efficiency of PSII （FvlFm） was not affected despite a decrease in the number of reaction centers and an inhibition of electron transfer to acceptors of PSII. It is concluded that tomato shoot may sustain short term exposure to high doses of cadmium despite growth inhibition. This property implies several physiological strategies linked to both avoidance and tolerance mechanisms.

关键词： cadmium chlorophyll fluorescence growth heavy metal toxicity Lycopersicon esculentum tomato

Intrinsic charm production of doubly charmed baryons:Collider vs. fixed-target

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Science China(Physics,Mechanics & Astronomy) 2020年第2期63卷 29-31页

作者： Ramona Vogt stanley J.Brodsky 无 Nuclear and Chemical Sciences Division Lawrence Livermore National LaboratoryLivermoreCA 94551USA Department of Physics University of CaliforniaDavisCA 95616USA Stanford Linear Accelerator Center Stanford UniversityStanfordCA 94309USA

The LHCb Collaboration has measured the doubly charmed baryon,■^++cc(ucc),through two different decay channels[1,2]in p+p collisions at center-of-mass energies of 7,8 and 13 *** they have performed similar searches for the doubly charmed baryon ■^+cc(dcc),it has not yet been observed by LHCb[3].However,the fixed-target experiment,SELEX,at Fermilab,reported the observation of the ■^+cc in two different decay channels with a 600 GeV charged hyperon beam[4,5].The beam was composed of an admixture of π^±,p,p components as well as the Σ^- *** discussion has arisen over the fact that the fixed-target observations have not been easily reproduced by the collider experiments at higher energies,where one might have expected the production rates to be much higher due to the orders of magnitude increase in the center of mass energy with LHCb.

关键词： doubly fixed decay

Cloning and characterization of a bursicon-regulated gene Su（H） in the house fly Musca domestica

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Insect Science 2009年第3期16卷 207-217页

作者： Songjie Wang Shiheng An David stanley Qisheng Song Division of Plant Sciences University of Missouri Columbia MO 65211 USDAIAgricultural Research Service Biological Control of Insects Research Laboratory 1503 S. Providence Road Columbia MO 65203 USA

Bursicon is a neuropeptide that regulates cuticle sclerotization （hardening and tanning） in insect via a G-protein coupled receptor. However, the signal transduction pathway downstream of the G-protein coupled receptor is currently not well known. In our recent microarray analysis, we identified a panel of genes regulated by bursicon in Drosophila. One of the genes, Suppressor of Hairless, or Su（H）, has drawn our attention because its product acts down-stream of the bursicon receptor. In the present study, we cloned the Drosophila homolog, mdSu（H）, from the house fly Musca domestica using 3＇ and 5＇ rapid amplification of complementary DNA ends. Real-time polymerase chain reaction analysis revealed that the level ofmdSu（H） transcript is up-regulated by ~3-fold 1 h after recombinant bursicon injection, which correlates well with the cuticle sclerotization process observed in the recombinant bursicon-injected flies. We infer that Su（H） is an essential gene involved in the insect cuticle sclerotization process.

关键词： cuticle sclcrotization gene regulation Musca domestica Notch pathway,r-bursicon suppressor of hairless

Experimental tests for a liquid-liquid critical point in water

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Science China(Physics,Mechanics & Astronomy) 2020年第12期63卷 30-71页

作者： Domenico Mallamace Carmelo Corsaro Francesco Mallamace H.Eugene stanley Department ChiBioFarAm(Industrial Chemistry) University of MessinaERIC and CASPE/INSTMMessina 98166Italy Dipartimento MIFT Universitàdi MessinaMessina 98166Italy Department of Nuclear Science and Engineering Massachusetts Institute of TechnologyCambridge MA 02139USA Istituto dei Sistemi Complessi(ISC)-CNR Rome 00185Italy Center for Polymer Studies and Department of Physics Boston UniversityBoston MA 02215USA

Water is a fascinating *** composition is simple—one oxygen and two hydrogen atoms—but its chemistry and physics are extremely complex and exhibit 75 documented *** these anomalies and their molecular origin are not completely understood,we know that hydrogen bonds play key roles in all of the phases of ***,there is experimental evidence that the polymorphism of the ice structure extends into the liquid phase and is associated with a liquid-liquid coexistence *** is currently a topic of great interest in water research because there are indications that the end point of the coexistence line corresponds to a second critical point inside the supercooled liquid *** examine the recent progress in understanding water anomalies and the liquid-liquid phase transition hypothesis,including the results of recent experimental work and molecular simulations of both bulk and confined *** examine experimental results that test whether the behavior of liquid water is consistent with the"liquid polymorphism"hypothesis that liquid water can exist in two distinct phases of differing *** also examine recent research on the anomalies of nanoconfined water and,in particular,on water in biological *** find that the concept of liquid polymorphism can also describe the properties of other liquids that have two characteristic length scales.

关键词： hydrophobic-hydrophilic interactions water systems thermal properties