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Demographic variation and habitat specialization of tree species in a diverse tropical forest of Cameroon

Forest Ecosystems 2014年第4期1卷 201-213页

作者： David Kenfack george B Chuyong Richard Condit Sabrina E Russo Duncan W thomas Center for Tropical Forest Science - Forest GEO Botany Department Smithsonian Tropical Research Institute Department of Botany and Plant Physiology University of Buea Center for Tropical Forest Science Smithsonian Tropical Research Institute School of Biological Sciences University of Nebraska Department of Biological Sciences Washington State University

Background： Many tree species in tropical forests have distributions tracking local ridge-slope-valley topography. Previous work in a 50-ha plot in Korup National Park, Cameroon, demonstrated that 272 species, or 63% of those tested, were significantly associated with topography. Methods： We used two censuses of 329,000 trees ≥1 cm dbh to examine demographic variation at this site that would account for those observed habitat preferences. We tested two predictions. First, within a given topographic habitat, species specializing on that habitat （＇residents＇） should outperform species that are specialists of other habitats （＇foreigners＇）. Second, across different topographic habitats, species should perform best in the habitat on which they specialize （＇home＇） compared to other habitats （＇away＇）. Species＇ performance was estimated using growth and mortality rates. Results： In hierarchical models with species identity as a random effect, we found no evidence of a demographic advantage to resident species. Indeed, growth rates were most often higher for foreign species. Similarly, comparisons of species on their home vs. away habitats revealed no sign of a performance advantage on the home habitat. Conclusions＂ We reject the hypothesis that species distributions along a ridge-valley catena at Korup are caused by species differences in trees _〉1 cm dbh. Since there must be a demographic cause for habitat specialization, we offer three alternatives. First, the demographic advantage specialists have at home occurs at the reproductive or seedling stage, in sizes smaller than we census in the forest plot. Second, species may have higher performance on their preferred habitat when density is low, but when population builds up, there are negative density-dependent feedbacks that reduce performance. Third, demographic filtering may be produced by extreme environmental conditions that we did not observe during the census interval.

关键词： tree Demographic variation and habitat specialization of tree species in a diverse tropical forest of Cameroon Figure

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Biochars produced from coconut palm biomass residues can aid regenerative agriculture by improving soil properties and plant yield in humid tropics

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Biochar 2020年第2期2卷 211-226页

作者： Murali Gopal Alka Gupta K.Shahul Hameed Neenu Sathyaseelan T.H.Khadeejath Rajeela george V.thomas ICAR-Central Plantation Crops Research Institute KasaragodKerala 671124India Present Address:Winsome F&D Consultant DubaiUAE Council for Food Research and Development KonniKeralaIndia

Lignin-rich recalcitrant biomass residues of coconut palms viz.(i)mature coconut husk,(ii)tender(immature or green)coconut husk(iii)coconut leaf petiole and(iv)coir-pith were successfully pyrolysed using a simple charring kiln into carbon-rich,black,light weight and porous *** alkalinity and good ash content made them fit for remediating acid *** potassium content in these biochars could help reduce the use of inorganic *** analysis showed the mass loss phases of husk and coconut leaf petiole biochars to be ***,all four biochars gave smooth curves indicating thermal stability of the *** seed germination and earthworm avoidance tests proved their potential as soil *** incubation studies with coconut biochars in graded doses,alone or in combination with coconut leaf vermicompost,increased the pH,organic carbon and potassium contents,and promoted plant-beneficial microbiota and enzyme *** studies with tender coconut husk biochar and coconut leaf vermicompost enhanced the dry weight of cowpea plants accompanied with increased arbuscular mycorrhizal sporulation and root colonization,and root nodule dry weight.A field trial resulted in higher chilli yields with tender coconut husk biochar+coconut leaf vermicompost *** results from our studies highlight the potential of pyrolysis as an innovative technology for quick recycling of highly recalcitrant coconut palm biomass residues to biochars as a local source of soil amendment to aid regenerative agriculture in humid tropics.

关键词： Coconut husks Biochar Plant-beneficial microbiota Earthworm avoidance Mycorrhizae

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The Impact of Human Activities on the Environment, Case of Mhondongori in Zvishavane, Zimbabwe

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Journal of Geoscience and Environment Protection 2020年第10期8卷 330-349页

作者： george Hove thomas Rathaha Precious Mugiya Management College of Southern Africa Durban South Africa Independent Consultant Zvishavane Zimbabwe

This study was proposed to explore the impact of human activities on the environment in Mhondongori. In this community, there are natural resources that include minerals, natural forest, wetlands, rivers and beautiful mountains. However, over the past two decades, the environmental quality of the community has deteriorated demonstrating irresponsible use of natural resources by humans. Indeed, if such poor natural resource management continues at the current rate, this would ultimately lead to extinction. Qualitative research design and convenience sampling methods were used. The study involved six participants who provided the data. An interview guide and observation techniques were used to collect data. Using content analysis data was classified into themes and a scorecard was used to determine the human activities on the environment and their impact. The results revealed that in Mhondongori, human activities that affected the environment were mining, veld fire, cutting down trees, overgrazing, excessive communal hunting and fishing, littering, water and air pollution. The impacts were the degradation of land, permanent scars on the landscape, deforestation, destruction of wildlife habitats, disappearance of wetlands, destruction of trees, grass, seed bank and seedlings, pollution of streets, bushes and rivers, disruption of migration and hibernation of animals. To conserve the environment, it was recommended that community leadership must develop appropriate environmental management strategies to mitigate these unfavourable impacts and that the state must empower Mhondongori leadership through reasonable legislative and other measures that would prevent environmental degradation.

关键词： Environment Environmental Management Human Activities Environmental Principles

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Modelling the daily reference evapotranspiration in semi-arid region of South India: A case study comparing ANFIS and empirical models

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Information Processing in Agriculture 2021年第1期8卷 173-184页

作者： Ramiro T.Gonzalez del Cerro M.S.P Subathra Nallapaneni Manoj Kumar Sebastian Verrastro S.thomas george Departamento de Ingenieria Electronica Facultad Regional Buenos AiresUniversidad Tecnologica NacionalBuenos AiresArgentina Department of Electrical Sciences Karunya Institute of Technology and SciencesCoimbatore 641114Tamil NaduIndia School of Energy and Environment City University of Hong KongKowloonHong KongChina Sustainable Solutionz T NagarChennai-600017Tamil NaduIndia

The estimation of evapotranspiration(ETo)is one of the main tools for the control of crop growth and to make a rational use of water *** estimate this parameter accurately,it is necessary to have a daily measurement of four meteorological variables,these are:temperature,solar radiation,relative humidity and wind *** is not always possible to count on all the variables,that is why there are empirical methods that use a limited number of variables that make an approximate estimate of the ETo *** of these models are applicable to different regions with completely different *** this paper,a study has been carried out to define the model of ETo estimation that best adapts to the semi-arid region in South *** different datasets for the same period from different meteorological stations were *** addition to the empirical methods for estimating ETo,computer models ANFIS(Adaptive Neuro-Fuzzy Inference System)were *** models consist in the future estimation of a certain parameter by using current variables and a history of variables and past *** results of this work show that ANFIS 11 model makes the best estimate with RMSD=0.002 and r=*** RITCHIE method is the most suitable empirical model for this region,which reaches RMSD=0.507 and r=*** addition,ranking of equations is elaborated for both datasets for daily estimates of ***,comparison is made with the results for each case and thus confirm or reject the convenience of one model over the *** achieve this,a series of statistical indicators were used:Index of agreement(d),MAE(Mean absolute error),SEE(Standard error of estimate)and RMSD(Root mean square difference).Moreover,a sensitivity analysis was performed in order to compare and show the stability of the best models when an error is introduced within the input *** this case,the empirical models demonstrate a better performance than the ANFIS *** work demonstrates that th

关键词： Evapotranspiration ANFIS ANN Semi-arid regions in India Coimbatore RITCHIE method

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Morphometric analysis of the drainage system and its hydrological implications in the rain shadow regions, Kerala, India

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Journal of Geographical Sciences 2011年第6期21卷 1077-1088页

作者： Jobin thomas Sabu JOSEPH K.P. THRIVIKRAMJI george ABE Department of Environmental Sciences University of Kerala Thiruvananthapuram-695 581 Kerala India Department of Geology University of Kerala Thiruvananthapuram-695 581 Kerala India Centre for Water Resources Development and Management Sub-Centre Kottayam Kerala India

The rain shadow regions requisite a comprehensive watershed development and management plan for sustainable water resources management. The Pambar River Basin （PRB） lies on the rain shadow region of the southern Western Ghats, India, where climate showed marked intra-basin variation. A morphometric analysis was done to evaluate the drainage characteristics of PRB using topographical maps and digital elevation data. PRB was divided into eighteen 4th order basins （SB1-SB18）, distributed along various climatic gradients. Lower order streams mostly dominate PRB and drainage pattern is a function of relief and structure. The terrain is highly dissected and prone to soil erosion during heavy storms and the elongated shape of PRB enables easier flood management. The influence of climate on drainage characteristics was evidently emphasized in basin morphometry. Four distinctively different classes were identified based on the morphometric similarities. The significance of morphometric analysis on the hydrological characterization is discussed and the relevance of the present study in water harvesting has been explicated.

关键词： morphometry drainage basin Pambar River Western Ghats India

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Improved lifestyle is associated with improved depression,anxiety and wellbeing over time in UK healthcare professionals during the COVID-19 pandemic:insights from the CoPE-HCP cohort study

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综合精神医学(英文) 2023年第1期36卷 19-27页

作者： Mohammed Y Khanji george Collett thomas Godec Carmela Maniero Sher May Ng Imrana Siddiqui Jaya Gupta Vikas Kapil Ajay Gupta William Harvey Research Institute Queen Mary University of LondonLondonUK Department of Cardiology Barts Heart CentreSaint Bartholomew's HospitalBarts Health NHS TrustLondonUK Newham University Hospital Barts Health NHS TrustLondonUK Wellbeing Hub Newham Training HubLondonUK NHS North East London CCG LondonUK Child and Adolescent Mental Health Service South West London and St George's Mental Health NHS TrustLondonUK

Background One potential modifiable factor to improve the mental health of healthcare professionals(HCPs)during the pandemic is *** This study aimed to assess whether an improved lifestyle during the pandemic is associated with improved mental health symptoms and mental well-being in HCPs over *** This was a cohort study involving an online survey distributed at two separate time points during the pandemic(baseline(July–September 2020)and follow-up(December 2020–March 2021))to HCPs working in primary or secondary care in the *** surveys assessed for major depressive disorder(MDD)(Patient Health Questionnaire-9(PHQ-9)),generalised anxiety disorder(GAD)(Generalised Anxiety Disorder-7(GAD-7)),mental well-being(Short Warwick-Edinburgh Mental Well-being Score(SWEMWBS))and self-reported lifestyle change(compared with the start of the pandemic)on multiple *** scores were calculated to estimate overall lifestyle change compared with that before the pandemic(at both baseline and follow-up).At each time point,separate logistic regression models were constructed to relate the lifestyle change score with the presence of MDD,GAD and low mental *** regression models were also developed relating the change in lifestyle scores from baseline to follow-up to changes in PHQ-9,GAD-7 and SWEMWBS *** 613 HCPs completed both baseline assessment and follow-up *** significant cross-sectional associations between increased lifestyle change scores and a reduced risk of MDD,GAD and low mental well-being were observed at both baseline and *** the study period,a whole unit increase in the change in novel scores(ie,improved overall lifestyle)over 4 months was inversely associated with changes in PHQ-9(adjusted coefficient:−0.51,95%confidence interval(CI):−0.73 to−0.30,p<0.001)and GAD-7 scores(adjusted coefficient:−0.32,95%CI:−0.53 to−0.10,p=0.004)and positively associated with the change in SWEMWBS scores

关键词： Edinburgh lifestyle coefficient

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DNA-PKcs subunits in radiosensitization by hyperthermia on hepatocellular carcinoma hepG_2 cell line

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World Journal of Gastroenterology 2002年第5期8卷 797-803页

作者： Walter J.Curran george Iliakis Department of Radiation Oncology of Kimmel Cancer Center Thomas Jefferson UniversityPhiladelphiaPA 19107USA

AIM: To investigate the role of DNA-PKcs subunits inradiosensitization by hyperthermia on hepatocellularcarcinoma HepG2 cell ***: Hep G2 cells were exposed to hyperthermiaand irradiation. Hyperthermia was given at 45.5 ℃Cellsurvival was determined by an in vitro clonogenic assay forthe cells treated with or without hyperthermia at varioustime points. DNA DSB rejoining was measured usingasymmetric field inversion gel electrophoresis (AFIGE). TheDNA-PKcs activities were measured using DNA-PKcs enzymeassay ***: Hyperthermia can significantly enhanceirradiation-killing cells. Thermal enhancement ratio ascalculated at 10 % survival was 2.02. The difference inradiosensitivity between two treatment modes manifestedas a difference in the α components and the almost sameβ components, which α value was considerably higher inthe cells of combined radiation and hyperthermia ascompared with irradiating cells (1.07 Gy-1 versus 0.44 Gy1). Survival fraction showed 1 logarithm increase after an8-hour interval between heat and irradiation, whereas DNA-PKcs activity did not show any recovery. The cells wereexposed to heat 5 minutes only, DNA-PKcs activity wasinhibited at the nadir, even though the exposure time waslengthened. Whereas the ability of DNA DSB rejoining wasinhibited with the increase of the length of hyperthermictime. The repair kinetics of DNA DSB rejoining aftertreatment with Wortmannin is different from thehyperthermic group due to the striking high slow ***: Determination with the cell extracts andthe peptide phosphorylation assay, DNA-PKcs activity wasinactivated by heat treatment at 45.5 C, and could notrestore. Cell survival is not associated with the DNA-PKcsinactivity after heat. DNA-PKcs is not a unique factor affectingthe DNA DSB repair. This suggests that DNA-PKcs do notplay a crucial role in the enhancement of cellularradiosensitivity by hyperthermia.

关键词：肝癌放射治疗放射敏感性催化作用 DNA激酶

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RADIATION BOUNDARY CONDITIONS FOR MAXWELL'S EQUATIONS:A REVIEW OF ACCURATE TIME-DOMAIN FORMULATIONS

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Journal of Computational Mathematics 2007年第3期25卷 305-336页

作者： thomas Hagstrom Stephen Lau Department of Mathematics and Statistics University of New MexicoAlbuquerqueNM 87131USA Division of Applied Mathematics Brown University182 George StreetProvidenceRI 02912USA

We review time-domain formulations of radiation boundary conditions for Maxwell＇s equations, focusing on methods which can deliver arbitrary accuracy at acceptable compu-tational cost. Examples include fast evaluations of nonlocal conditions on symmetric and general boundaries, methods based on identifying and evaluating equivalent sources, and local approximations such as the perfectly matched layer and sequences of local boundary conditions. Complexity estimates are derived to assess work and storage requirements as a function of wavelength and simulation time.

关键词： Maxwell's equations Radiation boundary conditions Fast algorithms Kirchoffformulas Perfectly matched layers.

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Role of the intracellular receptor domain of gp130 (exon 17) in human inflammatory bowel disease

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World Journal of Gastroenterology 2005年第8期11卷 1196-1199页

作者： Christoph J.Auernhammer Kathrin Zitzmann Fabian Schnitzler Julia Seiderer Peter Lohse george Vlotides Dieter Engelhardt Michael Sackmann Burkhard G(o|¨)ke thomas Ochsenkühn Department of Internal Medicine Ⅱ-Grosshadern Department of Clinical Chemistry-Grosshadern

AIM: To study the role of the intracellular receptor domain of gp130 in human inflammatory bowel disease (IBD).METHODS: We amplified and sequenced the complete exon 17 of the human gp130 gene in 146 patients with IBD. According to clinical and histopathological signs,the 146 patients with IBD were classified as having Crohn's disease (n = 73) or ulcerative colitis (n = 63),or as indeterminate status (n = 10).RESULTS: No mutations in exon 17 of the gp130 gene could be detected in any of the 146 patients with IBD ***: There is no evidence that mutations in exon 17 of the gp130 gene are involved in the pathogenesis of human IBD.

关键词： Exon 17 Inflammatory bowel disease gp130 gene

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A single-cell morpho-transcriptomic map of brassinosteroid action in the Arabidopsis root

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Molecular Plant 2021年第12期14卷 1985-1999页

作者： Moritz Graeff Surbhi Rana Jos R.Wendrich Julien Dorier thomas Eekhout Ana Cecilia Aliaga Fandino Nicolas Guex george W.Bassel Bert De Rybel Christian S.Hardtke Department of Plant Molecular Biology University of LausanneBiophore Building1015 LausanneSwitzerland Ghent University Department of Plant Biotechnology and BioinformaticsTechnologiepark 719000 GhentBelgium VIB Center for Plant Systems Biology Technologiepark 719000 GhentBelgium Bioinformatics Competence Center University of LausanneGenopode Building1015 LausanneSwitzerland School of Life Sciences The University of WarwickCoventryCV47ALUK Lead contact

The effects of brassinosteroid signaling on shoot and root development have been characterized in great detail but a simple consistent positive or negative impact on a basic cellular parameter was not *** this study,we combined digital 3D single-cell shape analysis and single-cell mRNA sequencing to charac-terize root meristems and mature root segments of brassinosteroid-blind mutants and wild *** resul-tant datasets demonstrate that brassinosteroid signaling affects neither cell volume nor cell proliferation ***,brassinosteroid signaling is essential for the precise orientation of cell division planes and the extent and timing of anisotropic cell ***,we found that the cell-aligning effects of brassinosteroid signaling can propagate to normalize the anatomy of both adjacent and distant brassinosteroid-blind cells through non-cell-autonomous functions,which are sufficient to restore growth ***,single-cell transcriptome data discern directly brassinosteroid-responsive genes from genes that can react non-cell-autonomously and highlight arabinogalactans as sentinels of brassinosteroid-dependent anisotropic cell expansion.

关键词： Arabidopsis root meristem brassinosteroid single-cell mRNA sequencing segmentation morphology BRI1 digital single-cell analysis

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