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Impact of tropospheric modelling on GnSS vertical precision:an empirical analysis based on a local active network

International Journal of Digital Earth 2018年第9期11卷 880-896页

作者： MªSelmira Garrido MªClara de Lacy Ana MªRojas Department of Cartographic Geodetic and Photogrammetric EngineeringUniversity of JaénJaenSpain Center for Advanced Studies in Earth Sciences University of JaénJaenSpain research group rnm282–microgeodesia jaén University of JaénJaenSpain

The troposphere affects Global navigation Satellite System(GnSS)signals due to the variability of the refractive *** delay is a function of the satellite elevation angle and the altitude of the GnSS receiver and depends on the atmospheric *** the residual tropospheric delay is not modelled carefully a bias error will occur in the vertical *** order to analyse the precise altimetric positioning based on a local active network,four scenarios in Southern Spain with different topographical,environmental,and meteorological conditions are presented,considering both favourable and non-favourable *** use of surface meteorological observations allows us to take into account the tropospheric conditions instead of a standard atmosphere,but introduces a residual tropospheric bias which reduces the accuracy of precise GnSS ***,with short observation times it is recommended not to estimate troposphere parameters,but to use an a priori model together with the standard *** results confirm that it is possible to achieve centimetre-scale vertical accuracy and precision with real time kinematic positioning even with large elevation differences with respect to the nearest reference *** numerical results may be taken into consideration for improving the altimetric configuration of the local active network.

关键词： Altimetry GnSS meteorological data active network tropospheric refraction

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Image analysis of Moroccan carob seeds(Ceratonia siliqua L.)revealed substantial intraspecific variations depending on climate and geographic origin

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Ecological Processes 2022年第1期11卷 455-468页

作者： jalal Kassout Younes Hmimsa Salama El Fatehi Abdeltif El Ouahrani Khalil Kadaoui Soufian Chakkour David Ariza‑Mateos Guillermo Palacios‑Rodríguez Rafael navarro‑Cerrillo Mohammed Ater Laboratory of Applied Botany Bio‑Agrodiversity TeamFaculty of SciencesUniversity of Abdelmalek EssaadiTétouanMorocco Associated International Laboratory EVOLEA INEE‑CNRS‑CNRSTMontpellierFrance Polydisciplinary Faculty of Larache University of Abdelmalek EssaadiLaracheMorocco Forestry Engineering Department ERSAF Research Group RNM‑360University of CórdobaCórdobaSpain

Background:The carob tree(Ceratonia siliqua L.)is one of the most iconic tree species of the Mediterranean region,with valuable economic,ecological and cultural *** has been exploited around the Mediterranean region since antiquity and has been regarded as an important component of natural habitats and traditional *** studies have focused on its morphological,biochemical,and genetic ***,less is known about the intraspecific variation of seed *** this regard,and as an overall objective,we intend to evaluate the amplitude and the expression of intraspecific variations of carob seed traits at different ecological scales ranging from individual trees to different geographical *** addition,we investigated how the climate along the study area affects the extent of carob seed *** image analysis techniques,we measured seven traits related to the size and the shape of 1740 seeds collected from 18 populations of spontaneous *** distributed along a latitudinal transect in Morocco under different bioclimatic ***:The morphometric analysis of carob seed showed the effectiveness of adopted approach to highlight the amount and the amplitude of intraspecific variation according to geographic and climatic *** trait analysis revealed high intraspecific variability,explained by differences between and among carob populations and geographic *** area,perimeter,length,and width showed the largest variability between geographic ***,circularity,aspect ratio,and seed roundness showed higher variability at the tree ***,our results show that seed traits vary depending on altitude and climate ***:Revealing the amount and the structure of intraspecific traits variability of carob seed provides interesting insights to understand the mechanisms underlying trees adaptation to various environmental and ecological ***,intraspecific variatio

关键词： Carob tree Image analysis Seed traits Intraspecific variation Morocco

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Exploring seven hundred years of transhumance, climate dynamic, fire and human activity through a historical mountain pass in central Spain

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Journal of Mountain Science 2016年第7期13卷 1139-1153页

作者： José Antonio LóPEZ-SáEZ Francisca ALBA-SánCHEZ Sandra ROBLES-LóPEZ Sebastián PéREZ-DíAZ Daniel ABEL-SCHAAD Silvia SABARIEGO-RUIZ Arthur GLAIS research group Archaeobiology Institute of History CSIC Dept.Botany Faculty of Sciences University of Granada Dept.of Plant Biology Faculty of Biology Complutense University LETG CAEn GEOPHEn-UMR 6554 CnRS University of Caen-Normandie

A high-altitude peat sequence from the heart of the Spanish Central System(Gredos range) was analysed through a multi-proxy approach to determine the sensitivity of high-mountain habitats to climate, fire and land use changes during the last seven hundred years, providing valuable insight into our understanding of the vegetation history and environmental changes in a mountain pass close to a traditional route of transhumance. The pollen data indicate that the vegetation was dominated by shrublands and grasslands with scattered pines in high-mountain areas, while in the valleys cereals, chestnut and olive trees were cultivated. Strong declines of high-mountain pines percentages are recorded at 1540, 1675, 1765, 1835 and 1925 cal AD, which may be related to increasing grazing activities and/or the occurrence of anthropogenic fires. The practice of mountain summer farming and transhumance deeply changed and redesigned the landscape of the high altitudes in central Spain(Gredos range) since the Middle Ages, although its dynamics was influenced in some way by climate variability of the past seven centuries.

关键词： Climate and human impacts Fire Late Holocene Gredos range Vegetation history

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Proton magnetic resonance spectroscopy in the evaluation of infiltration zone of cerebral alveolar echinococcosis

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Chinese Medical Journal 2012年第13期125卷 2260-2264页

作者： WAnG Jian YAO Wei-hong YI Ba-nu LIU Shen ZHAnG De-qing JIAnG Chun-hui ZHAnG Li-min nIU Jun-qiao JIA Wen-xiao WEn Hao Imaging Center/MRI Room Department ofneurosurgeryFirst Affiiiated Hospital Xinjiang MedicalUniversity Urmqi Xinjiang 830011 China Xinjiang Clinical research Institute of Echinococcosis Urumqi Xinjiang 830011 China

Background Cerebral alveolar echinococcosis （CAE） grows infiltratively like a malignant tumor, causing great harm to the human body. It is possible to display mass lesions of CAE using various imaging systems, but regarding the infiltrating proliferation active regions, it is difficult to evaluate its actual range using conventional magnetic resonance imaging （cMRI）. This research focused on proton magnetic resonance spectroscopy （1HMRS） techniques to find the mass and infiltration zone of CAE. We explored the marginal zone （MZ） of CAE nearly close to the actual infiltrating scope, to provide reliable images for clinical purposes, to overcome shortcomings of cMRI, to formulate beneficial clinical surgical plans and assess prognosis. Methods Between September 2005 and May 2011, 15 patients who were suffering from CAE （36 effective lesions altogether） were examined by 1HMRS at the first affiliated hospital of Xinjiang Medical University. Multi-voxel 1HMRS was acquired with a 1.5T MRI scanner. Concentrations and the ratios of the metabolites of CAE were calculated. Furthermore, changes in the concentrations of the metabolites containing n-acetyl-aspartic-acid （nAA）, choline （Cho）, creatine （Cr）, lipids and lactate （Lip＋Lac） and the ratios of Cho/Cr, nAA/Cr, （Lip＋Lac）/Cr were compared in the substantial region, 0-10 rnm MZ, and 11-20 mm MZ of the infiltration zone, as well as the corresponding contralateral part of the normal brain parenchyma area （control group）. Results In this study, the ratios of Cho/Cr in the substantial region, 0-10 mm MZ of infiltration zone and the control group were 1.78＋0.70, 1.90＋_0.54, and 0.78＋_0.15, respectively; the ratios of nAA/Cr were 1.60＋0.20, 1.80＋0.42, 2.24＋_0.86, respectively; the ratios of （Lip＋Lac）/Cr were 25.69＋_13.84, 25.18＋16.03, and 0.61 ＋0.15, respectively. From the control group, 11-20 mm MZ to 0-10 mm MZ and the substantial region of CAE, the concentrations of the metabolites showed that nAA and Cho decreased gradually an

关键词： cerebral alveolar echinococcosis marginal zone magnetic resonance spectroscopy evaluation

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