检索结果-南通市图书馆

The influence of canopy-layer composition on understory plant diversity in southern temperate forests

Forest Ecosystems 2017年第2期4卷 154-166页

作者： luciana mestre Monica Toro-Manriquez Rosina Soler Alejandro Huertas-Herrera Guillermo Martinez-Pastur Maria Vanessa Lencinas National Scientific and Technical Research Council (CONICET) Austral Center for Scientific Research (CADIC-CONICET) Houssay 200 9410 Ushuaia Tierradel Fuego Argentina

Background： Understory plants represents the largest component of biodiversity in most forest ecosystems and plays a key role in forest *** their importance, the influence of overstory-layer composition on understory plant diversity is relatively poorly understood within deciduous-evergreen broadleaved mixed *** aim of this work was to evaluate how tree overstory-layer composition influences on understory-layer diversity in three forest types（monospecific deciduous Nothofagus pumilio（Np）, monospecific evergreen Nothofagus betuloides（Nb）, and mixed ***（M） forests）, comparing also between two geographical locations（coast and mountain） to estimate differences at landscape ***： We recorded 46 plant species： 4 ferns, 12 monocots, and 30 ***-layer composition influences the herb-layer structure and diversity in two different ways： while mixed forests have greater similarity to evergreen forests in the understory structural features, deciduous and mixed were similar in terms of the specific composition of plant *** pure stands were the most diverse, meanwhile evergreen stands were least *** of exclusive species of mixed forest could represent a transition where evergreen and deciduous communities meet and ***, landscape has a major influence on the structure, diversity and richness of understory vegetation of pure and mixed forests likely associated to the magnitude and frequency of natural disturbances, where mountain forest not only had highest herb-layer diversity but also more exclusive ***： Our study suggests that mixed Nothofagus forest supports coexistence of both pure deciduous and pure evergreen understory plant species and different assemblages in coastal and mountain *** the mixture of canopy patch types within mixed stands will be important for conserving the natural patterns of understory plant composition in southern beech mixe

关键词： Landscape Understory communities Understory structure Forest structure Nothofagus Conservation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Flowering and seeding patterns in pure and mixed Nothofagus forests in Southern Patagonia

引用

Ecological Processes 2016年第1期5卷 261-272页

作者： Monica Toro Manriquez luciana mestre Maria Vanessa Lencinas Alvaro Promis Guillermo Martinez Pastur Rosina Soler National Scientific and Technical Research Council(CONICET) Austral Center for Scientific Research(CADIC-CONICET)Houssay 2009410 UshuaiaTierra del FuegoArgentina Department of Silviculture and Nature Conservation University of ChileAv.Santa Rosa 113159206 SantiagoLa PintanaChile

Introduction:Variation in reproductive phenology among species is an important mechanism for maintaining species *** mixed forests,the impact of limiting(biotic and abiotic)factors on tree reproductive success regulates the maintenance of species in balanced proportions or the conversion towards monospecific *** study offer a significant first approach to the reproductive phenology of mixed forests,assessing flowering,seeding and loss factors on reproductive success in three forest types(pure deciduous Nothofagus pumilio(Np),evergreen Nothofagus betuloides(Nb)and mixed(M)forests),comparing also between two geographical locations(coast and mountain),during one growing ***:Flowering falling started early in *** fall occurred first and more concentrated in Np,while in Nb,it was progressive during *** in M combined both patterns,but with better reproductive performance of both *** production was greater in Nb(42,900,000 ha^(−1))than in Np(710,000 ha^(−1)),while M presented intermediate values(31,900,000 ha^(−1)).Abortion was greatest in Np(19% of female flowers and 10% of immature fruits),while fruit predation was low(7-9%)in all forest *** seed was the main loss factor,but with low net values for each species in *** geographical location,sea proximity generated a quick starting of the growing season in coast compared to mountain ***,we detected forest types×location interactions in flowering and seeding patterns(*** male flower production and in empty and viable seeds),with differences in species response according to ***:Both deciduous and evergreen species have reproductive advantages in mixed compared to pure ***,mixed were more similar to pure evergreen forests in their reproductive traits and the incidence of the limiting *** study of only one growing season does not allow us to conclude whether mixed forests are stable communities,but we cont

关键词： Broadleaved Mixed forest Geographical location Leaf habit Reproductive phenology Seed quality

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

A wavelet approach of investing behaviors and their effects on risk exposures

引用

Financial Innovation 2021年第1期7卷 498-535页

作者： Roman mestre MRE Universitéde Montpellier UFR d’économie Avenue Raymond Dugrand-Site de Richter C.S.7960634960 Montpellier Cedex 2France

Exposure to market risk is a core objective of the Capital Asset Pricing Model(CAPM)with a focus on systematic ***,traditional OLS Beta model estimations(Ordinary Least Squares)are plagued with several statistical ***,the CAPM considers only one source of risk and supposes that investors only engage in similar *** order to analyze short and long exposures to different sources of risk,we developed a Time–Frequency Multi-Betas Model with ARMA-EGARCH errors(Auto Regressive Moving Average Exponential AutoRegressive Conditional Heteroskedasticity).Our model considers gold,oil,and Fama–French factors as supplementary sources of risk and wavelets *** used 30 French stocks listed on the CAC40(Cotations Assistées Continues 40)within a daily period from 2005 to *** conjugation of the wavelet decompositions and the parameters estimates constitutes decision-making support for managers by multiplying the interpretive *** the short-run,(“Noise Trader”and“High-Frequency Trader”)only a few equities are insensitive to Oil and Gold fluctuations,and the estimated Market Betas parameters are scant different compared to the Model without ***,in the long-run,(fundamentalists investors),Oil and Gold affect all stocks but their impact varies according to the Beta(sensitivity to the market).We also observed significant differences between parameters estimated with and without wavelets.

关键词： Risk exposures CAPM Multi-betas model Time-frequency analysis MODWT Oil Gold

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Stock profiling using time–frequency‑varying systematic risk measure

引用

Financial Innovation 2023年第1期9卷 1525-1553页

作者： Roman mestre Montpellier Research in Economics University of MontpellierAvenue Raymond Dugrand34960 MontpellierCedex 2France

This study proposes a wavelets approach to estimating time–frequency-varying betas in the capital asset pricing model(CAPM)*** dynamic of systematic risk across time and frequency is analyzed to investigate stock risk-profile ***,we emphasize the effect of an investor’s investment horizon on the robustness of portfolio *** use a daily panel of French stocks from 2012 to *** show that varying systematic risk varies in time and frequency,and that its short and long-run evolutions *** observe differences in short and long dynamics,indicating that a stock’s betas differently fluctuate to early announcements or signs of ***,short-run and long-run betas exhibit similar dynamics during persistent *** are more volatile during times of crisis,resulting in greater or lesser robustness of risk *** differences exist in short-run and longrun risk profiles,implying a different asset *** conclude that the standard CAPM assumes short-run ***,investors should consider time–frequency CAPM to perform systematic risk analysis and portfolio allocation.

关键词： Maximal overlap discrete wavelets transform Time Frequency-varying beta Time Frequency rolling window Risk-profile Systematic risk

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Predator-induced physiological responses in tadpoles challenged with herbicide pollution

引用

Current Zoology 2013年第4期59卷 475-484页

作者： Pablo BURRACO Lidia Jimenez DUARTE Ivan GOMEZ-mestre Ecology Evolution and Development Group Estaci6n Biol6gica de Dofiana (EBD-CSIC) E-41092 Seville Spain Av. Las Ciencias 4 2℃ 41020 Sevilla Spain

Predators induce plastic responses in multiple prey taxa, ranging from morphological to behavioral or physiological changes. In amphibians, tadpoles activate plastic responses to reduce predation risk by reducing their activity rate and altering their morphology, specifically tail depth and pigmentation. Furthermore, there is now evidence that tadpoles＇ defenses are modi- fied when predators combine with other stressful factors such as pollutants or competitors, but our knowledge on the physiologi- cal responses underlying these responses is still scarce. Here we study physiological responses in Pelobates cultripes tadpoles exposed to a natural predator （larvae of the aquatic beetle Dytiscus circumflexus）, non-lethal concentrations of herbicide （gly- phosate, 0.5 mg/L and 1.0 mg/L） or both factors combined. We measured corticosterone levels, standard metabolic rate, oxidative damage （TBARS） and activity of antioxidant enzymes, and immune response （via leukocyte count）. Tadpoles reduced their corti- costerone concentration by ca. 24% in the presence of predator cues, whereas corticosterone did not change in the presence of glyphosate. Two enzymes involved in antioxidant response also decreased in the presence of predators （14.7% and 13.2% respec- tively） but not to glyphosate. Herbicide, however, increased the number of neutrophils and reduced that of lymphocytes, and had an interaction effect with predator presence. Standard metabolic rate did not vary across treatments in our experiment. Thus we show a marked physiological response to the presence of predators but little evidence for interaction between predators and low levels of herbicide. Multiple assessment of the physiological state of animals is important to understand the basis and conse- quences ofphenotypic plasticity

关键词： Inducible defenses Physiological responses Corticosterone Glyphosate Spadefoot toads Oxidative stress

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Qigong in the treatment of children with autism spectrum disorder:A systematic review

引用

Journal of Integrative Medicine 2019年第4期17卷 250-260页

作者： Jorge Magalhaes Rodrigues Mariana mestre Larry Ibarra Fredes Faculty of Medicine of Oporto University (FMUP) Alameda Prof. Hemani Monteiro 4200-319 Porto Portugal Portuguese Institute of Taiji and Qigong Urbanizacao da Boufa Grande Rua E n 102 4470-765 Maia Portugal European Institute of Traditional Chinese Studies (IEETC) Rua Dom Joao IV 399 4000-302 Porto Portugal

Background: Autism spectrum disorder is a condition that affects all races, ethnic and socioeconomic groups. With a high incidenee ratio of one in every 68, it has become one of the most discussed psychiatric disorders. For this reason, the need for investigating novel treatments has been emerging. Qigong, a traditional Chinese mind-body technique, has already proven to be able to reduce symptoms of several physical and psychological illnesses. Objective: The purpose of this systematic review is to examine and categorize the current scientific evidence regarding the efficacy of Qigong on children suffering from autism spectrum disorders. Search strategy: A systematic literature search of the electronic scientific databases PubMed, Clinical ***, BioMed Central, PubMed Central and Google Scholar was performed to identify studies of Qigong in the treatment of children with autism spectrum disorder. Inclusion criteria: This review included randomized controlled trials, replication studies, retrospective studies and observational follow-up studies of Qigong on children with autism spectrum disorder. Case reports and case series were excluded. Data extraction and analysis: Two researchers independently evaluated the methodological quality of all included studies. Any discrepancies were solved by discussion until consensus was achieved. Results: Our literature search identified 157 publications, and 10 additional publications from hand search of references. After duplicate removal, 103 records remained. After the title/abstract screening, 19 publications were obtained for detailed evaluation. After detailed evaluation, 10 studies were included. Seven studies were conducted with small children with 2-6 years old employing Qigong massage, and three studies were con ducted with older children aged 7-17 years old applying both Qigong massage (one study) and Neigong (two studies). Conclusion: Studies demonstrated that Qigong has interesting and promising applicability an

关键词： Autism spectrum disorder Qigong Mind-body interventions Children

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

X-linked Toll-like receptor 7 polymorphism associated with susceptibility to Chikungunya Fever

引用

Asian Pacific Journal of Tropical Medicine 2019年第3期12卷 137-141页

作者： Daniela M.Rauseo Mercedes Fernández-mestre Laboratorio de Fisiopatología Centro de Medicina ExperimentalIVIC

Objective: To investigate the association between TLR3 and TLR7 polymorphisms with susceptibility and clinical manifestations of Chikungunya ***: A total of 177 individuals were studied: 73 patients with a confirmed diagnosis for Chikungunya virus and 104 non-infected individuals. Polymorphisms were determined by Polymerase Chain Reaction-Restriction Fragment Length Polymorphism(PCR-RFLP).Results: Our analysis showed an increased CC genotype frequency of the TLR7 rs3853839 polymorphism in male patients compared to control(29% versus 2%,respectively; OR=20.69; 95% CI=2.55-167.36; P<0.001). Furthermore,arthritis(acute and chronic) was frequently found in CC male patients. On the contrary,65% of CG carriers were no-infected males(29% versus 65%,respectively; OR=0.23,95% CI=0.48-3.04; P=0.002). Finally,we observed a higher frequency of lymphopenia in CG male patients(CG=666.86±233.77,GG=1,314.27±752.29 cells/mm3,P=0.047). Conclusions: Our results suggest the TLR7 rs3853839 polymorphism is associated with lymphopenia and increased susceptibility to Chikungunya Fever in males.

关键词： Chikungunya Fever Toll-like-receptors Single-nucleotide polymorphisms Disease susceptibility

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Ionic Species Affect the Self-Propulsion of Urease-Powered Micromotors

引用

Research 2020年第1期2020卷 349-362页

作者： Xavier Arque Xavier Andres Rafael mestre Bernard Ciraulo Jaime Ortega Arroyo Romain Quidant Tania Patino Samuel Sanchez Institute for Bioengineering of Catalonia(IBEC) The Barcelona Institute of Science and Technology(BIST)Baldiri i Reixac 10-1208028 BarcelonaSpain Institute of Photonic Sciences(ICFO) The Barcelona Institute of Science and TechnologyCarl Friedrich Gauss 308860 CastelldefelsBarcelonaSpain InstitucióCatalana de Recerca i Estudis Avançats(ICREA) Pg.Lluís Companys 2308010 BarcelonaSpain Chemistry Department University of RomeTor VergataVia della Ricerca Scientifica00133 RomeItaly

Enzyme-powered motors self-propel through the catalysis of in situ bioavailable fuels,which makes them excellent candidates for biomedical ***,fundamental issues like their motion in biological fluids and the understanding of the propulsion mechanism are critical aspects to be tackled before a future application in ***,we investigated the physicochemical effects of ionic species on the self-propulsion of urease-powered *** showed that the presence of PBS,NaOH,NaCl,and HEPES reduced self-propulsion of urease-powered micromotors pointing towards iondependent mechanisms of *** studied the 3D motion of urease micromotors using digital holographic microscopy to rule out any motor-surface interaction as the cause of motion decay when salts are present in the *** order to protect and minimize the negative effect of ionic species on micromotors’performance,we coated the motors with methoxypolyethylene glycol amine(mPEG)showing higher speed compared to noncoated motors at intermediate ionic *** results provide new insights into the mechanism of urease-powered micromotors,study the effect of ionic media,and contribute with potential solutions to mitigate the reduction of mobility of enzyme-powered micromotors.

关键词： holographic salts catalysis

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Body Schema Deformation in Teleoperation： Effect of Sensori-motor Contingences

引用

Psychology Research 2011年第1期1卷 26-41页

作者： Yves Rybarczyk Daniel mestre New University of Lisbon Lisbon Portugal CNRS-University of Mediterranean Marseilles France

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Deep convolutional neural network for damaged vegetation segmentation from RGB images based on virtual NIR-channel estimation

引用

Artificial Intelligence in Agriculture 2022年第1期6卷 199-210页

作者： Artzai Picon Arantza Bereciartua-Perez Itziar Eguskiza Javier Romero-Rodriguez Carlos Javier Jimenez-Ruiz Till Eggers Christian Klukas Ramon Navarra-mestre TECNALIA Basque Research and Technology Alliance(BRTA)Parque Tecnológico de BizkaiaC/Geldo.Edificio 700E-48160 Derio-BizkaiaSpain University of the Basque Country Plaza Torres Quevedo48013 BilbaoSpain BASF Espanola S.L.Carretera A376 41710 Utrera SevillaSpain BASF SE Speyererstrasse 267117 LimburgerhofGermany

Performing accurate and automated semantic segmentation of vegetation is a first algorithmic step towards more complex models that can extract accurate biological information on crop health,weed presence and phenological state,among ***,models based on normalized difference vegetation index(NDVI),near infrared channel(NIR)or RGB have been a good indicator of vegetation ***,these methods are not suitable for accurately segmenting vegetation showing damage,which precludes their use for downstream phenotyping *** this paper,we propose a comprehensive method for robust vegetation segmentation in RGB images that can cope with damaged *** method consists of a first regression convolutional neural network to estimate a virtual NIR channel from an RGB ***,we compute two newly proposed vegetation indices from this estimated virtual NIR:the infrared-dark channel subtraction(IDCS)and infrared-dark channel ratio(IDCR)***,both the RGB image and the estimated indices are fed into a semantic segmentation deep convolutional neural network to train a model to segment vegetation regardless of damage or *** model was tested on 84 plots containing thirteen vegetation species showing different degrees of damage and acquired over 28 *** results show that the best segmentation is obtained when the input image is augmented with the proposed virtual NIR channel(F1=0:94)and with the proposed IDCR and IDCS vegetation indices(F1=0:95)derived from the estimated NIR channel,while the use of only the image or RGB indices lead to inferior performance(RGB(F1=0:90)NIR(F1=0:82)or NDVI(F1=0:89)channel).The proposed method provides an end-to-end land cover map segmentation method directly from simple RGB images and has been successfully validated in real field conditions.

关键词： Vegetation indices estimation Vegetation coverage map Near infrared estimation Convolutional neural network Deep learning

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：