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Interaction between climate and management on beta diversity components of vegetation in relation to soil properties in arid and semi-arid oak forests, Iran

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Journal of Arid Land 2019年第1期11卷 43-57页

作者： Heydari MEHDI Aazami FATEMEH Faramarzi MARZBAN Omidipour REZA Bazgir MASOUD Pothier DAVID prévosto bernard Department of Forest Science College of Agriculture Ilam University Department of Rangeland and Watershed Management College of Agriculture Ilam University Department of Rangeland and Watershed Management College of Natural Resources and Earth Sciences Shahrekord University Department of Soil Science College of Agriculture Ilam University Department of Wood and Forest Sciences Centre for Forest Research Laval University Irstea-National Research Institute of Science and Technology for Environment and Agriculture

This study aimed to investigate the interaction between regions with different climatic conditions(arid vs. semi-arid) and management(protected vs. unprotected) on the turnover and nestedness of vegetation in relation to physical, chemical and biological properties of soils in the Ilam province of Iran. In each of the two regions, we sampled 8 sites(4 managed and 4 unmanaged sites) within each of which we established 4 circular plots(1000 m^2) that were used to investigate woody species, while two micro-plots(1 m×1 m) were established in each 1000-m^2 plot to analyze herbaceous species. In each sample unit, we also extracted three soil samples(0–20 cm depth) for measuring soil properties. The results indicated that the interaction between region and conservational management significantly affected the percent of canopy cover of Persian oak(Quercus brantii Linddl), soil respiration, substrate-induced respiration, as well as beta and gamma diversities and turnover of plant species. The percent of oak canopy cover was positively correlated with soil silt, electrical conductivity, available potassium, and alpha diversity, whereas it was negatively correlated with plant turnover. In addition, plant turnover was positively related to available phosphorus, while nestedness of species was positively related to organic carbon and total nitrogen. According to these results, we concluded that physical, chemical, and biological characteristics of limited ecological niche generally influenced plant diversity. Also, this study demonstrated the major contribution of the beta diversity on gamma diversity, especially in semi-arid region, because of the higher heterogeneity of vegetation in this area.

关键词： climatic conditions conservation management beta diversity oak forests physical-chemical property semi-arid region

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The influence of pressure waves in tidal gravity records

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Geodesy and Geodynamics 2023年第1期14卷 15-25页

作者： bernard Ducarme Catholic University of Louvain Georges Lemaître Centre for Earth and Climate Research(ELI)Louvain-la-NeuveBelgium

For the reduction of atmospheric effects,observed gravity has initially been corrected by using the computed barometric admittance k of the in situ measured pressure,expressed in nms-2/hPa units and estimated by least squares ***,the local pressure changes alone cannot account for the atmospheric mass attraction and loading when the coherent pressure field exceeds a specific size,i.e.,with increasing *** overcome this difficulty,it is necessary to compute the total atmospheric effect at each station using the global pressure ***,the direct subtraction of the total gravity effect,provided by the models of pressure correction,is not yet satisfactory for S2 and other tidal components,such as K2 and P1,which include solar heating pressure *** paper identifies the origin of the problem and presents strategies to obtain a satisfactory ***,we set up a difference vector between the tidal factors of M2 and S2 after correction of the pressure and ocean tides *** vector,hereafter denoted as RES,presents the advantage of being practically insensitive to calibration *** minimum discrepancy between the tidal parameters of M2 and S2 corresponds to the minimum of the RES vector norm *** we adopt the hybrid pressure correction method,separating the local and the global pressure contribution of the models and replacing the local contribution by the pressure measured at the station multiplied by an admittance *** tested this procedure on 8 stations from the IGETS superconducting gravimeters network(former GGP network).For stations at an altitude lower than 1000 m,the value of dopt is always smaller *** discrepancy between the tidal parameters of the M2 and S2 waves is always lower than0.05% on the amplitude factors and 0.025° on the *** these stations,a correlation exists between the altitude and the value *** results at the three Central European stations Conrad,Pecny and Vienna are

关键词： Atmospheric pressure waves Atmospheric pressure correction in tidal records Atmospheric pressure models ERA5 and MERRA-2

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A Fresh Look at the Structures of Nylons and the Brill Transition

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Advanced Fiber Materials 2021年第4期3卷 203-209页

作者： bernard Lotz Institut Charles Sadron CNRS and Universitéde Strasbourg23Rue du Loess67034 StrasbourgFrance

The common knowledge of the crystal structures of nylons dates back to the early 1950s with the work of Bunn and *** describes the packing of sheets made of hydrogen-bonded stems in an extended chain *** alpha phase structures have a specific powder X-ray diffraction pattern with reflections at 4.4Åand 3.7Å.On heating,reflections trans-form progressively and merge at≈4.2Åat the so-called“Brill transition”.Other diffraction patterns have been recorded for different types of nylons and thermal *** patterns were interpreted only as indicating the existence of“variants”of the alpha ***,neither their structure,nor the origin of the Brill transition were *** structural analyses and molecular modeling approaches have provided new insights in these long-standing structural ***“variants”feature chain conformations that are“pleated”.The Brill transition does not involve the standard extended chains of the alpha phase but corresponds to a dynamic interconversion(≈10^(10)/s)between mirror conformations of these pleated stems.

关键词： Nylons Crystal structures Phase transitions Brill transition

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After Sendai:Is Africa Bouncing Back or Bouncing Forward from Disasters?

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International Journal of Disaster Risk Science 2016年第1期7卷 41-53页

作者： bernard Manyena International Disaster Management Humanitarian and Conflict Response Institute University of Manchester

The 187 countries that adopted the Sendai Framework for Disaster Risk Reduction 2015–2030 at the March 2015 UN World Conference on Disaster Risk Reduction included most African countries. Many developing regions of the world, particularly in Asia and Latin America, made considerable progress in implementing the previous Hyogo Framework for Action 2005–2015. But,despite the fact that Africa is one of the regions most vulnerable and least resilient to disasters, which continue to be exacerbated by poverty, climate change, rapid urbanization, and structural transformation, it saw only slow progress. This article considers the challenges Africa faces in implementing the Sendai Framework and recommends that besides ‘‘Africanizing'' Sendai goals and strengthening the region's political commitment to disaster risk reduction(DRR), Africa should also develop a single framework that integrates DRR, sustainable development, climate change adaptation, and conflict prevention. Equally important is the need for a strong recognition that disasters are created endogenously as well as exogenously, and thus require local solutions and local investment.

关键词： Sub-Saharan Africa Climate change adaptation Disaster risk reduction Resilience Sendai framework Sustainable development

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The apical plasma membrane of chitin-synthesizing epithelia

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Insect Science 2013年第2期20卷 139-146页

作者： bernard Moussian Animal Genetics Interfaculty Institute for Cell Biology University of Tubingen 72076 TEtbingen Germany

Chitin is the second most abundant polysaccharide on earth. It is produced at the apical side of epidermal, tracheal, fore-, and hindgut epithelial cells in insects as a central component of the protective and supporting extracellular cuticle. Chitin is also an important constituent of the midgut peritrophic matrix that encases the food supporting its digestion and protects the epithelium against invasion by possibly ingested pathogens. The enzyme producing chitin is a glycosyltransferase that resides in the apical plasma membrane forming a pore to extrude the chains of chitin into the extracellular space. The apical plasma membrane is not only a platform for chitin synthases but, probably through its shape and equipment with distinct factors, also plays an important role in orienting and organizing chitin fibers. Here, I review findings on the cellular and molecular constitution of the apical plasma membrane of chitin-producing epithelia mainly focusing on work done in the fruit fly Drosophila melanogaster.

关键词： apical undulae cuticle extracellular matrix epidermis microvilli

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Synopsis of Leymus Hochst.(Triticeae:Poaceae)

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Journal of Systematics and Evolution 2009年第1期47卷 67-86页

作者： bernard R.BAUM Eastern Cereals and Oilseeds Research Centre Agriculture and Agri-Food CanadaCentral Experimental Farm

Leymus is a genus in the Triticeae tribe, Poaceae. The taxa of this genus are allopolyploid species which possess the Ns and Xm genomes. According to cytological, cytogenetic and molecular genetic analyses, some species of Hystrix and Elymus ought to be transferred to this genus. A world revision of the genus Leymus is needed. In this paper we summarize experimental results, provide a key to sections, species and varieties, and list all the taxa we recognize in Leymus with their synonyms. This synopsis is a new taxonomic system to be used for the revision of Leymus.

关键词： genome Leymus new taxonomic system section species varieties

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Clonidine attenuates morphine withdrawal and subsequent drug sensitization in rhesus monkeys

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Acta Pharmacologica Sinica 2007年第4期28卷 473-483页

作者： bernard LE FOLL Behavioral Neuroscience Branch Intramural Research ProgramNational Institute on Drug AbuseNational Institutes ofHealthBaltimoreMaryland 21224USA

Aim:Clonidine is an α2adrenoceptor agonist that is frequently used to reducewithdrawal symptoms during opioid detoxification in *** long-termeffects of clonidine on withdrawal symptoms and its effects on subsequent drugexposure have not been thoroughly *** aim of the study was todetermine if clonidine administered during morphine withdrawal in rhesus mon-keys produces long-lasting effects on withdrawal symptoms and alters the effectsof subsequently taken drugs of ***:Adult male rhesus monkeyswere treated with increasing doses of morphine for 90 d to induce opiate (narcotic)*** immediate and long-lasting effects of 1 week’s administration ofclonidine were measured via the recording of morphine withdrawal signs and thesubsequent effects of challenge injections of morphine or ***:Monkeys chronically treated with morphine displayed withdrawal signs that lasted2 weeks after cessation of morphine administration and displayed sensitized re-sponses to subsequent morphine and cocaine *** significantlyreduced certain morphine withdrawal signs and overall withdrawal score,but theseeffects did not persist upon cessation of clonidine *** to theeffects of morphine and cocaine were significantly reduced in monkeys previ-ously treated with ***:Our results suggest that in addition toits short-term alleviating effect on morphine withdrawal signs,clonidine may re-duce subsequent effects of drugs of abuse after prolonged abstinence.

关键词： cocaine withdrawal drug challenge crosssensitization recurrence monkeys

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Convergence of random zeros on complex manifolds

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Science China Mathematics 2008年第4期51卷 707-720页

作者： bernard SHIFFMAN Department of Mathematics Johns Hopkins University

We show that the zeros of random sequences of Gaussian systems of polynomials of increasing degree almost surely converge to the expected limit distribution under very general hypotheses. In particular, the normalized distribution of zeros of systems of m polynomials of degree N, orthonormalized on a regular compact set K ? ? m , almost surely converge to the equilibrium measure on K as N → ∞.

关键词： random polynomial ample line bundle zeros of holomorphic sections equilibrium measure 32A60 32L10 60G99

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AN EXPONENTIAL INEQUALITY FOR AUTOREGRESSIVE prOCESSES IN ADAPTIVE TRACKING

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Journal of Systems Science & Complexity 2007年第2期20卷 243-250页

作者： bernard BERCU Institut de Mathematiques de Bordeaux Universite Bordeaux 1 UMR5251 351 cours de la liberation 33405 Talence cedex France

A wide range of literature concerning classical asymptotic properties for linear models with adaptive control is available, such as strong laws of large numbers or central limit theorems. Unfortunately, in contrast with the situation without control, it appears to be impossible to find sharp asymptotic or nonasymptotic properties such as large deviation principles or exponential inequalities. Our purpose is to provide a first step towards that direction by proving a very simple exponential inequality for the standard least squares estimator of the unknown parameter of Gaussian autoregressive process in adaptive tracking.

关键词： Adaptive tracking autoregressive process exponential inequalities least squares martingales

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Adaptability of the ocean and earth tidal models based on global observations of the superconducting gravimeters

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Science China Earth Sciences 2005年第11期48卷 1859-1869页

作者： Ducarme bernard Vandercoilden Leslie Royal Observatory of Belgium 3av. Circulaire B-1180 Brussels Belgium

The adaptability of recent ocean tidal models and Earth tidal models is investigated comprehensively by means of 22 high precision tidal gravity observation series at 20 stations of the Global Geodynamics project. Careful preprocessing of the original observations was carried out using international standard algorithms and the tidal gravity parameters were computed. The gravity load vectors of 8 main constituents are obtained based on loading computation theory and various global ocean models. The loading corrections of 14 secondary constituents are obtained based on a two-dimensional interpolation technique. Considering different characteristics of the wave amplitude, a method of “non-identical weighted mean” is developed for computing the av-eraged observed residual and remaining residual vectors at each station. The efficiency of the loading correction and the discrepancy between corrected amplitude factors and theoretical ones are analyzed. Meanwhile the calibration problem of the instruments is also discussed. After loading correction, the averaged tidal gravity parameters for all stations are obtained. The results show that the discrepancies between the global mean amplitude factors and theoretical values are less than 0.3%, the largest calibration error of the instruments is less than 0.5%. On the other hand, there are indications that the slight phase advance of K1 with respect to O1 in Mathews’ theory could be verified by ground based tidal gravity observations.

关键词： superconducting gravimeters Global Geodynamics project determination of the tidal gravity parameters verification of the global ocean and Earth tidal models.

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