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Shedding Light on Large-Scale Chromatin Reorganization in Arabidopsis thaliana

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Molecular Plant 2012年第3期5卷 583-590页

作者： Martijn van Zanten Federico Tessadori Anton j.M. Peeters paul Fransz Molecular Plant Physiology Institute of Environmental Biology Utrecht University Padualaan 8 3584 CH Utrecht The Netherlands Department of Plant Breeding and Genetics Max Planck Institute for Plant Breeding Research Carl-von-Linne＇-weg 10 50829 Cologne Germany Cardiac Development and Genetics Group Hubrecht Institute for Developmental Biology and Stem Cell Research Uppsalalaan 8 3584 CT Utrecht The Netherlands Plant Ecophysiology Institute of Environmental Biology Utrecht University Padualaan 8 3584 CH Utrecht The Netherlands Nuclear Organization Group Swammerdam Institute for Life Sciences University of Amsterdam Kruislaan 318 1098 SM Amsterdam The Netherlands

Plants need to respond quickly and appropriately to various types of light signals from the environment to optimize growth and development. The immediate response to shading, reduced photon flux （low light）, and changes in spectral quality involves changes in gene regulation. In the case of more persistent shade, the plant shows a dramatic change in the organization of chromatin. Both plant responses are controlled via photoreceptor signaling proteins. Re- cently, several studies have revealed similar features of chromatin reorganization in response to various abiotic and biotic signals, while others have unveiled intricate molecular networks of light signaling towards gene regulation. This opinion paper briefly describes the chromatin （de）compaction response from a light-signaling perspective to provide a link be- tween chromatin and the molecular network of photoreceptors and E3 ubiquitin ligase complexes.

关键词： light signaling chromatin compaction molecular network Arabidopsis

Scales of snow depth variability in high elevation rangeland sagebrush

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Frontiers of Earth Science 2017年第3期11卷 469-481页

作者： Molly E. TEDESCHE Steven R. FASSNACHT paul j. MEIMAN Watershed Science Department of Ecosystem Science and Sustainability Colorado State University Fort Collins CO 80523-1476 USA Intemational Arctic Research Center Water & Environmental Research Center Institute of Northern Engineering University of Alaska Fairbanks Fairbanks AK 99775 USA Cooperative Institute for Research in the Atmosphere Fort Collins CO 80523-1375 USA Natural Resources Ecology Laboratory Fort Collins CO 80523-1499 USA Abt. Kartographie GIS & Femerkundung Geographisches Institut Georg-August-Universitat Gottingen 37077 Gottingen Germany Rangeland Ecosystem Science Department of Forest and Rangeland Stewardship Colorado State University Fort Collins CO 80523 USA

In high elevation semi-arid rangelands, sage- brush and other shrubs can affect transport and deposition of wind-blown snow, enabling the formation of snowdrifts. Datasets from three field experiments were used to investigate the scales of spatial variability of snow depth around big mountain sagebrush （Artemisia tridentata Nutt.） at a high elevation plateau rangeland in North Park, Colorado, during the winters of 2002, 2003, and 2008. Data were collected at multiple resolutions （0.05 to 25 m） and extents （2 to 1000 m）. Finer scale data were collected specifically for this study to examine the correlation between snow depth; sagebrush microtopogra- phy, the ground surface, and the snow surface, as well as the temporal consistency of snow depth patterns. Vario- grams were used to identify the spatial structure and the Moran＇s I statistic was used to determine the spatial correlation. Results show some temporal consistency in snow depth at several scales. Plot scale snow depth variability is partly a function of the nature of individual shrubs, as there is some correlation between the spatial structure of snow depth and sagebrush, as well as between the ground and snow depth. The optimal sampling resolution appears to be 25-cm, but over a large area, this would require a multitude of samples, and thus a random stratified approach is recommended with a fine measurement resolution of 5-cm.

关键词： snow hydrology high elevation rangelands,spatial statistics variograms snow pack spatial variability,snow drifts

The use of electro-deoxidation in molten salts to reduce the energy consumption of solar grade silicon and increase the output of PV solar cells

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Progress in Natural Science:Materials International 2015年第6期25卷 583-590页

作者： paul R.Coxon Michael Coto Eimutis juzeliunas Derek j.Fray Department of Materials Science & Metallurgy University of Cambridge Institute of Chemistry Centre for Physical Sciences & Technology 3. Klaip?da University

Solar photovoltaics,based upon silicon,are the most popular form of solar cell with efficiencies around 20%.These efficiencies can be further increased by employing light trapping schemes to minimise optical losses through scattering and reflection which enhances the amount of light absorbed and number of photo-carriers *** approaches employ antireflection coatings（ARCs） or texturise the surface of the silicon disks,so that the structure consists of an array of needles which can absorb most of the ***,these structures are created by leaching the silicon with hydrofluoric-based acids or by reactive ion etching（RIE） *** paper reviews some of the methods for improving the energy efficiency of silicon production,and describes the use of electro-deoxidation of SiO;layers,on silicon,in molten calcium chloride to form nanoporous black silicon（b-Si） *** coating b-Si surface with TiO;,a common ARC,extremely black surfaces with negligible reflectance of about 0.1%,are produced,which can have applications for low-cost high efficiency solar cells.

关键词： Black silicon Solar cell photovoltaics Silicon molten salt Electrochemistry

Application of None Cement Aluminamagnesia Gunning Mix with Special High Reactive Alumina in Steel Ladles

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China's Refractories 2020年第1期29卷 20-26页

作者： jérome KIENNEMANN paul SOLER johnson LEE Alteo Gardanne 20062France

During calcining the aluminum hydroxide according to the Bayer process in a rotary kiln,the process of incomplete conversion to alpha alumina by soft calcination leads to a special intermediate alumina product containing microcrystalline of primary crystal alpha alumina particles less than 0.4μm,and other alumina phases with finer microcrystalline of less than 0.2μm *** special alumina powder has similar properties to silica fume or clay,such as high surface area and reactivity,fast wetting,low water demand and high *** can partially or completely replace silica fume and clay in dry gunning *** works towards improving the high temperature resistance of the gunning material matrix as well as the corrosion resistance and service life of the gunning *** application results show that:the ladle cementfree alumina-magnesia dry gunning mix with this special alumina sub-micro powder,compared with traditional dry gunning materials,has lower rebound loss(<10%),better adhesion rate,higher corrosion resistance and peeling resistance;and it can replace the veneering casting repair to achieve the similar performance.A further improvement goal is to replace the initial casting linings,thus this concept will give a new revolution to the monolithic steel ladles.

关键词： none cement gunning mix special reactive alumina monolithic steel ladles

Improving rice photosynthesis and yield through trehalose 6-phosphate signaling

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Molecular Plant 2022年第4期15卷 586-588页

作者： Matthew j.paul javier A.Miret Cara A.Griffiths Plant Science Rothamsted ResearchAL52JQ HarpendenHertfordshireUK

THE T6P-SnRK1 SIGNALING PATHWAY IN PLANTS,The biosynthetic route for the synthesis of trehalose in plants is through a low-flux pathway that leads to the accumulation of micromolar amounts of trehalose 6-phosphate(T6P)and trehalose when sucrose is available.T6P accumulates in proportion to sucrose(Lunn et al.,2006)as an indispensable regulator of carbohydrate utilization(Schluepmann et al.,2003).At least some of the indispensability of T6P and its profound and widespread effects on plant growth and development can be explained through T6P inhibition of the SNF1-related protein kinase SnRK1(Zhang et al.,2009),a central regulator of plant responses to carbon and energy status.

关键词： molar synthesis explained

Granular titanite from the Roter Kamm crater in Namibia:Product of regional metamorphism,not meteorite impact

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Geoscience Frontiers 2022年第3期13卷 156-163页

作者： Aaron j.Cavosie Christopher j.Spencer Noreen Evans Kai Rankenburg Robert j.Thomas paul H.Macey Space Science and Technology Centre and The Institute for Geoscience Research School of Earth and Planetary ScienceCurtin UniversityPerthWA 6102Australia Dept.of Geological Sciences and Geological Engineering Queen’s UniversityOntarioCanada john de Laeter Centre Curtin UniversityPerthWA 6102Australia Council for Geoscience BellvilleWestern CapeSouth Africa

Accessory minerals with so-called granular texture have risen in importance as geochronological tools for U-Pb dating of meteorite impact events. Grain-scale recrystallization, typically triggered by a combination of high-strain deformation and post-impact heating, can create a polycrystalline microstructure consisting of neoblasts that expel radiogenic Pb, which are thus ideal for isotopic dating. While granular domains in zircon and monazite from shocked rocks have been demonstrated to preserve impact ages,few U-Pb dating studies have been conducted on granular microstructures in titanite(CaTiSiO;). Here we report the occurrence of granular-textured titanite from ~2020 Ma granite basement rock exposed in the rim of the 4–5 Ma Roter Kamm impact structure in Namibia. Orientation mapping reveals two microstructurally distinct titanite populations: one consisting of strained/deformed grains, and the other consisting of grains that comprise aggregates of strain-free neoblasts. In situ U-Pb geochronology on 37 grains shows that most grains from both titanite populations yield indistinguishable U-Pb dates of ca.1025 Ma, consistent with the observed microstructures forming during the Mesoproterozoic Namaqua Orogeny. Only four grains preserved older age domains, recording ca. 1875 Ma Paleoproterozoic metamorphism. Two significant observations emerge:(1) none of the analyzed titanite grains yield the 2020 Ma igneous crystallization age previously established from zircon in the same sample, and(2) no age-resetting was detected that could be attributed to the 4 to 5 Ma Roter Kamm impact *** the similarity of the neoblastic microstructure to minerals from other sites with an established impact provenance, the granular texture and near-complete Pb-loss in titanite from Roter Kamm granite instead records a Paleo-to Mesoproterozoic polymetamorphic history, rather than Miocene age shockrelated processes. These results highlight the critical importance of grain-scale cont

关键词： Namibia Roter Kamm Titanite EBSD Geochronology

On the origin of X-shaped radio galaxies

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Research in Astronomy and Astrophysics 2012年第2期12卷 127-146页

作者： Gopal-Krishna Peter L.Biermann Lszló .Gergely paul j.Wiita National Centre for Radio Astrophysics TIFRPune University Campus Max Planck Institute for Radioastronomy Department of Physics & Astronomy University of Bonn Department of Physics & Astronomy University of Alabama Department of Physics University of Alabama at Huntsville KIT-Karlsruhe Institute for Technology Institute for Experimental Nuclear Physics Department of Theoretical Physics University of Szeged Department of Experimental Physics University of Szeged Department of Physics The College of New Jersey

After a brief, critical review of the leading explanations proposed for the small but important subset of radio galaxies showing an X-shaped morphology （XRGs） we propose a generalized model, based on the jet-shell interaction and spin- flip hypotheses. The most popular scenarios for this intriguing phenomenon invoke either hydrodynamical backflows and over-pressured cocoons or rapid jet reorienta- tions, presumably from the spin-flips of central engines following the mergers of pairs of galaxies, each of which contains a supermassive black hole. We confront these models with a number of key observations, and thus argue that none of the models is capable of explaining the entire range of the salient observational properties of XRGs, although some of the arguments raised in the literature against the spin-flip scenario are probably not tenable. We then propose a new scenario which also involves galac- tic mergers but would allow the spin of the central engine to maintain its direction. Motivated by detailed multi-band observations of the nearest radio galaxy, Centaurus A, this new model emphasizes the role of the interactions between the jets and the shells of stars and gas that form and rotate around the merged galaxy and can cause temporary deflections of the jets, occasionally giving rise to an X-shaped radio struc- ture. Although each model is likely to be relevant to a subset of XRGs, the bulk of the evidence indicates that most of them are best explained by the jet-shell interaction or spin-flip hypotheses.

关键词： galaxies: active - galaxies: jets - gravitational waves - ISM - radiocontinuum: galaxies

Characteristics of a gold-doped electrode for application in high-performance lithium-sulfur battery

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journal of Energy Chemistry 2022年第1期31卷 116-128,I0004页

作者： Vittorio Marangon Daniele Di Lecce Dan j.L.Brett paul R.Shearing jusef Hassoun University of Ferrara Department of Chemical and Pharmaceutical SciencesVia Fossato di Mortara 17Ferrara44121Italy Electrochemical Innovation Lab Department of Chemical EngineeringUCLLondon WC1E 7JEUnited Kingdom The Faraday Institution Quad OneBecquerel AveHarwell CampusDidcot OX11 ORAUnited Kingdom National Interuniversity Consortium of Materials Science and Technology(INSTM) University of Ferrara Research UnitUniversity of FerraraVia Fossato di Mortara17Ferrara 44121Italy

Bulk sulfur incorporating 3 wt% gold nano-powder is investigated as possible candidate to maximize the fraction of active material in the Li-S battery *** material is prepared via simple mixing of gold with molten sulfur at 120℃,quenching at room temperature,and *** comprehensive study reports relevant electrochemical data,advanced X-ray computed tomography(CT)imaging of the positive and negative electrodes,and a thorough structural and morphological characterization of the S:Au 97:3 w/w *** cathode exhibits high rate capability within the range from C/10 to 1C,a maximum capacity above 1300 mAh gs^(-1),and capacity retention between 85%and 91%after 100 cycles at 1C and C/3 *** novel formulation enables a sulfur fraction in the composite cathode film as high as 78 wt%,an active material loading of 5.7 mg cm^(-2),and an electrolyte/sulfur(E/S)ratio of 5μL mg^(-1),which lead to a maximum areal capacity of 5.4 mAh cm^(-2).X-ray CT at the micro-and nanoscale reveals the microstructural features of the positive electrode that favor fast conversion kinetics in the *** analysis of sulfur distribution in the porous cathode displays that electrodeposition during the initial cycle may trigger an activation process in the cell leading to improved ***,the tomography study reveals the characteristics of the lithium anode and the cell separator upon a galvanostatic test prolonged over 300 cycles at a 2C rate.

关键词： Lithium-sulfur battery Sulfur loading Electrolyte/sulfur ratio Gold nanoparticles X-ray tomography

Arthropod prey of imported fire ants （Hymenoptera： Formicidae） in Mississippi sweetpotato fields

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Insect Science 2013年第4期20卷 467-471页

作者： Tahir Rashid jian Chen james T. Vogt paul j. McLeod Aicorn State University Extension~Research Demonstration Farm & Tech Transfer Center Mound Bayou Mississippi USDA ARS Bio- logical Control of Pests Research Unit Stoneville Mississippi USDA FS Inventory & Analysis Knoxville Tennessee Department of Entomology University of Arkansas Fayetteville Arkansas United States

The red imported fire ants, Solenopsis invicta （Buren）, are generally considered pests. They have also been viewed as beneficial predators feeding on other insect pests of various agroecosystems. This study documents the foraging habits of fire ants in a sweetpotato field in Mississippi. Fire ant foraging trails connecting outside colonies to a sweetpotato field were exposed and foraging ants moving out of the field toward the direction of the colony were collected along with the solid food particles they were carrying. The food material was classified as arthropod or plant in origin. The arthropod particles were identified to orders. Fire ant foragers carried more arthropods than plant material. Coleoptera and Homoptera were the most abundant groups preyed upon. These insect orders contain various economically important pests of sweetpotato. Other major hexapod groups included the orders Hemiptera, Diptera and Collembola. The quantity of foraged material varied over the season. No damage to sweetpotato roots could be attributed to fire ant feeding. Imported fire ant foraging may reduce the number of insect pests in sweetpotato fields.

关键词： foraging imported fire ant predation Solenops& invicta sweetpotato