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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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Hsa-miR-214-3p inhibits breast cancer cell growth and improves the tumor immune microenvironment by downregulating b7H3

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Oncology research 2025年第1期33卷 103-121页

作者： Yan Lu Kang Wang Yuanhong Peng Meng Chen Lin Zhong Luji Huang F U Cheng Xindan Sheng Xin Yang Manzhao Ouyang george A Calin Zhiwei He China-America Cancer Research Institute Guangdong Medical University Dongguan 523808 China. GCP Center Shunde Hospital Southern Medical University (The First People's Hospital of Shunde Foshan) Shunde 528300 China. Department of Gastrointestinal Surgery Shunde Hospital Southern Medical University (The First People's Hospital of Shunde Foshan) Shunde 528300 China. The Second School of Clinical Medicine Southern Medical University Guangzhou 510080 China. Department of Translational Molecular Pathology The University of Texas MD Anderson Cancer Center Houston TX 77030 USA. Department of Oncology Shunde Hospital Southern Medical University (The First People's Hospital of Shunde Foshan) Shunde 528300 China.

background:Immune checkpoint inhibitors play an important role in the treatment of solid tumors, but the currently used immune checkpoint inhibitors targeting programmed cell death-1 (PD-1), programmed cell death ligand-1 (PD-L1), and cytotoxic T-lymphocyte antigen-4 (CTLA-4) show limited clinical efficacy in many breast cancers. b7H3 has been widely reported as an immunosuppressive molecule, but its immunological function in breast cancer patients remains unclear.Methods:We analyzed the expression of b7H3 in breast cancer samples using data from the Cancer Genome Atlas Program (TCGA) and the Gene Expression Omnibus (GEO) databases. MicroRNAs were selected using the Tarbase, miRTarbase, and miRbase databases. The regulatory role of the microRNA hsa-miR-214-3p on b7H3 was investigated through dual-luciferase reporter assays, which identified the specific action sites of interaction. The expression levels of b7H3 and hsa-miR-214-3p in human breast cancer tissues and adjacent normal tissues were quantified using Western blotting and quantitative PCR (qPCR). experiments were performed to observe the effects of modulating the expression of b7H3 or hsa-miR-214-3p on breast cancer cell proliferation and apoptosis. Additionally, the regulatory impact of hsa-miR-214-3p on b7H3 was examined. Enzyme-linked immunosorbent assays (ELISA) and flow cytometry were employed to assess the effects of co-cultured breast cancer cells and normal human peripheral blood mononuclear cells (PbMCs) on immune cells and associated cytokines.Results:In breast cancer tissues, the expression level of b7H3 is inversely correlated with that of hsa-miR-214-3p, as well as with the regulatory effects on breast cancercell behavior. Hsa-miR-214-3p was found to inhibit breast cancer cell growth by downregulating b7H3. Importantly, our research identified, for the first time, two binding sites for hsa-miR-214-3p on the 3' UTR of b7H3, both of which exert similar effects independently. Co-culture experime

关键词： b7H3 breast cancer Hsa-miR-214-3p Immunotherapy

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Physical activity and its relationship with COVID-19 cases and deaths:Analysis of ***

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Journal of Sport and Health Science 2021年第5期10卷 570-576页

作者： george b.Cunningham Center for Sport Management Research and Education Department of Health and KinesiologyTexas A&M UniversityCollege StationTX 77843USA

Purpose:The study was to examine county-level associations of physical activity with coronavirus disease 2019(COVID-19)cases and deaths,per 100,000 county ***:Data were collected from publicly available data sources for 3142 counties and equivalents,including the District of *** health ratings,percentage uninsured,percentage unemployed,median household income,percentage female residents,percentage White residents,percentage of residents 65 years of age or older,and rural designation served as ***:The two-level random intercept regression showed that physical activity rates at the county level were statistically and negatively associated with COVID-19 cases and *** analyses showed that physical activity rates moderated the relationship between cases and deaths,such that the relationship was strongest when physical activity rates were ***:The results presented here offer empirical evidence of the benefits of county-level physical activity during a *** for public health and physical activity provision are discussed.

关键词： Coronavirus disease 2019 Deaths PA

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A Survey of Mycorrhizal Colonization in the 50-ha Korup Forest Dynamic Plot in Cameroon

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American Journal of Plant Sciences 2014年第10期5卷 1403-1415页

作者： Eneke Esoeyang Tambe bechem george bindeh chuyong belinda Tengu Fon Department of botany and Plant Physiology University of Buea Buea Cameroon

A study was carried out in the 50-ha Korup Forest Dynamic Plot in South West Cameroon, to evaluate the diversity of mycorrhizal associations as well as to determine the effect of habitat types on the type of mycorrhizal association. A total of 781 individual trees belonging to 51 families, 165 genera and 252 tree species, were sampled from the four habitat types found in the plot: low drier, hill slope, ridge top and wetland complexes. In each habitat type, all stems ≤ 1 cm depth at breast height had already been tagged, measured, mapped and identified to the species level. Root samples were collected, cleared, stained and examined microscopically for mycorrhizal type. Of the total number of species sampled, 248 (98.41%) formed mycorrhizal associations with only 4 (1.59%) being non mycorrhizal. For mycorrhizal trees, 232 (93.55%) formed exclusively arbuscular mycorrhiza, 10 (4.03%) formed ectomycorrhiza, while 6 (2.42%) formed both ecto- and arbuscular mycorrhiza. The ridge top harbored the least number (152) of mycorrhizal trees while the low drier area harbored the most number (266) of mycorrhizal trees. Although habitat effect was not significant in influencing mycorrhizal colonization of tree species, some tree species did show aggregated patterns in particular habitats.

关键词： Korup Forest Dynamic Plot Arbuscular Mycorrhiza Ectomycorrhiza Cameroon

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Friction surfacing of AISI 316 over mild steel: A characteriation study

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Defence Technology（防务技术） 2018年第4期14卷 306-312页

作者： R.george Sahaya Nixon b.S.Mohanty R.Sathish Department of Mechanical Sathyabama University Department of Mechanical Engineering St.Joseph's College of Engineering Department of Mechanical Engineering SRM Easwari

An attempt has been made with overlaying of stain-less steel on mild steel by the technique of friction surfacing. This investigation elaborates the excellence acquired by different combination of the process parameters used in friction surfacing specifically traverse speed of the cross slide, speed of rotation of the spindle and the uniaxial compressive load. Excellent overlaying has been obtained amongst the chosen materials. To which, the coating can be done with various set of process parameters. It has been observed that the bond strength of the coating was found to be at a maximum of 502 MPa by ram tensile *** upon this results the surface methodology was characterized with scanning electron *** authenticating the results, the coated specimen was subjected to salt spray test. The bonding microstructure was characterized using optical microscopy and X-ray diffraction. Corrosion resistance of surfaced coatings was found to be more inferior to that of mechtrode material and greater with the substrate.

关键词： Friction surfacing Rotational speed Traverse speed Axial load Salt spray test Microstructure XRD analysis Ram tensile test

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Exploring the configuration space of elemental carbon with empirical and machine learned interatomic potentials

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npj Computational Materials 2023年第1期9卷 987-998页

作者： george A.Marchant Miguel A.Caro bora Karasulu Livia b.Pártay Department of Chemistry University of WarwickCoventry CV47ALUK Department of Chemistry and Materials Science Aalto University02150 EspooFinland

We demonstrate how the many-body potential energy landscape of carbon can be explored with the nested sampling algorithm,allowing for the calculation of its pressure-temperature phase *** compare four interatomic potential models:Tersoff,EDIP,GAP-20 and its recently updated version,*** evaluation is focused on their macroscopic properties,melting transitions,and identifying thermodynamically stable solid structures up to at least 100 *** phase diagrams of the GAP models show good agreement with experimental ***,we find that the models’description of graphite includes thermodynamically stable phases with incorrect layer *** adding a suitable selection of structures to the database and re-training the potential,we have derived an improved model—GAP-20U+gr—that suppresses erroneous local minima in the graphitic energy *** extreme high pressure nested sampling identifies two novel stable structures in the GAP-20 model,however,the stability of these is not confirmed by electronic structure calculations,highlighting routes to further extend the applicability of the GAP models.

关键词： carbon potential configuration

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Tricube Weighted Linear Regression and Interquartile for Cloud Infrastructural Resource Optimization

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Computer Systems Science & Engineering 2023年第6期45卷 2281-2297页

作者： Neema george b.K.Anoop Vinodh P.Vijayan Srinivas University MangaloreIndia Mangalam College of Engineering KottayamIndia

Cloud infrastructural resource optimization is the process of precisely selecting the allocating the correct resources either to a workload or *** workload execution,accuracy,and cost are accurately stabilized in opposition to the best possible framework in real-time,efficiency is *** addition,every workload or application required for the framework is characteristic and these essentials change over ***,the existing method was failed to ensure the high Quality of Service(QoS).In order to address this issue,a Tricube Weighted Linear Regression-based Inter Quartile(TWLR-IQ)for Cloud Infrastructural Resource Optimization is introduced.A Tricube Weighted Linear Regression is presented in the proposed method to estimate the resources(i.e.,CPU,RAM,and network bandwidth utilization)based on the usage history in each cloud ***,Inter Quartile Range is applied to efficiently predict the overload hosts for ensuring a smooth *** results show that our proposed method is better than the approach in Cloudsim under various performance *** results clearly showed that the proposed method can reduce the energy consumption and provide a high level of commitment with ensuring the minimum number of Virtual Machine(VM)Migrations as compared to the state-of-the-art methods.

关键词： Cloud infrastructure tricube weighted linear regression inter quartile CPU RAM network bandwidth utilization

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Endocannabinoid immune and vascular signaling

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Acta Pharmacologica Sinica 2000年第12期21卷 16-26页

作者： george b STEFANO beth Israel Deaconess Medical Center boston MA 02215 NY 11568 and Mind body Medical Institute Neuroscience Research Institute P O box 210 State University of New York at Old Westbury USA

HISTORY Hemp has been cultivated for 7000 to 8000 yearsc. The Sumerian/babylonian term for cannabis hemp is K (a)N(a)b(a), and it is one of the longest surviving root words in Indo-Semitic-European language. In 2700 bC, Shen Nung, a contributor to early Chinese medicine, mentions cannabis in the pharmacopoeia. Around 500 bC Zoroaster, a Persian prophet, in the Zend-Avesta, listing 10 000 medicinal plants, includes hemp. In the first century AD the Chinese begin making paper from hemp as an inexpensive means of preserving information. In 800 AD the Islamic prophet Mohammed allows cannabis use. In 1100, Moslems use cannabis to start

关键词： anandamide nitric oxide 2-arachi-donyl-glyceral cannabinoid receptors vascular endothe-lium hemp immune cells

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High-throughput computational discovery of In_(2)Mn_(2)O_(7) as a high Curie temperature ferromagnetic semiconductor for spintronics

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npj Computational Materials 2019年第1期5卷 529-535页

作者： Wei Chen Janine george Joel b.Varley Gian-Marco Rignanese Geoffroy Hautier Institute of Condensed Matter and Nanoscicence(IMCN) Universitécatholique de Louvain1348 Louvain-la-NeuveBelgium Lawrence Livermore National Laboratory LivermoreCA 94550USA

Materials combining strong ferromagnetism and good semiconducting properties are highly desirable for spintronic applications(e.g.,in spin-filtering devices).In this work,we conduct a search for concentrated ferromagnetic semiconductors through highthroughput computational *** screening reveals the limited availability of semiconductors combining ferromagnetism and a low effective *** identify the manganese pyrochlore oxide In_(2)Mn_(2)O_(7) as especially promising for spin transport as it combines low electron effective mass(0.29m0),a large exchange splitting of the conduction band(1.1 eV),stability in air,and a Curie temperature(about 130 K)among the highest of concentrated ferromagnetic *** rationalise the high performance of In_(2)Mn_(2)O_(7) by the unique combination of a pyrochlore lattice favouring ferromagnetism with an adequate alignment of O–2p,Mn–3d,and In–5s forming a dispersive conduction band while enhancing the Curie temperature.

关键词： temperature ferromagnetic semiconductors

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Re: Errors in Zhao et al(2015), Impact of enteral nutrition on energy metabolism in patients with Crohn's disease

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World Journal of Gastroenterology 2016年第9期22卷 2867-2868页

作者： Kathryn A Kaiser brandon J george david b Allison Office of Energetics School of Public Health University of Alabama at Birmingham

We report invalidating errors related to the statistical approach in the analysis and data inconsistencies in a published single cohort study of patients with Crohn's disease. We provide corrected calculations from the available data and request that a corrected analysis be provided by the authors. These errors should be corrected.

关键词： statistical error differences in nominal significance data inconsistency

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