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Land Use and Land Cover Dynamics in the Eseka Alluvial Gold Mining District, Centre Region, Cameroon

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Journal of Geographic Information system 2024年第4期16卷 289-305页

作者： shu Vejiline Lum-Ndob Fonge Beatrice Ambo Ambe Godlove Neba Ateh Kevin Ijunghi Enerst tata Cheo Emmanuel suh Department of Plant science Faculty of Science University of Buea Buea Cameroon Department of Mining and Mineral Engineering National Higher Polytechnic Institute The University of Bamenda Bambili Cameroon Economic Geology Unit Department of Geology Faculty of Science University of Buea Buea Cameroon Department of Geology Mining and Environmental Science The University of Bamenda Bambili Cameroon

Local populations in Cameroon thrive on forest resources and the flow of ecosystem services they provide are pivotal in sustaining national economy, improving people’s lives, safeguarding biodiversity, and mitigating the impacts of environmental changes. The exploitation of these resources invariably leads to deforestation and forest degradation. This study was designed to evaluate land use land cover change (LULCC) in the Eseka alluvial gold mining district with the aid of Landsat images. In the investigation of forest cover change, four Landsat satellite images for (1990, 2002, 2015 and 2022) were used. Ground-truthing also helped to identify the activities carried out by the local population and to determine agents, drivers and pressures of land use and land cover change. Four main land cover classes namely: forest, agricultural land, settlement/mining camps and water bodies were selected. Between 1990 and 2022, the proportion of forest decreased from 98% to 34% while those of agricultural land and settlement/mining camps increased from 2% to 60% and 0.54% to 6% respectively. Analysis showed ongoing deforestation with forest cover loss of ~98,263 ha in 32 years giving a cover change percentage of 63.94%. Kappa coefficient for the study period ranged from 0.92 to 0.99. Forest cover loss could be attributed to farming activities, wood extraction and alluvial gold mining activities. Economic motives notably the need to increase household income from a frequent demand for farm and wood products in neighbouring towns and the quest for gold were the main drivers of these activities. Hence, this study assesses the impact of human activities from the mining sector on the forest ecosystem in a bid to inform mitigation policies.

关键词： Land Use and Land Cover Changes Biodiversity Alluvial Gold Mining Drivers Landsat Images Ground-Truthing Mitigation

PCR-HRM for Genomic surveillance of sARs-CoV-2: A Variant Detection Tool in Côte d’Ivoire, West Africa

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American Journal of Molecular Biology 2024年第3期14卷 166-185页

作者： Aboubacar sylla solange Kakou-Ngazoa tata Gniré safiatou Coulibaly Yakoura Karidja Ouattara Mireille sylvie Kouamé-sina Zeinab Ouattara David Ngolo Coulibaly Brice Kouakou Bla Mireille Dosso Molecular Biology Platform Pasteur Institute Cte dIvoire Abidjan Cte dIvoire Laboratory of Biology and Health UFR Biosciences University Flix Houphout Boigny Abidjan Cte dIvoire Genetic and Cancer Laboratory Molecular Genetics Platform Pasteur Institute Cte dIvoire Abidjan Cte dIvoire Epidemic Virus Department Pasteur Institute Cte dIvoire Abidjan Cte dIvoire

The rise of new viruses, like sARs-CoV-2 causing the COVID-19 outbreak, along with the return of antibiotic resistance in harmful bacteria, demands a swift and efficient reaction to safeguard the health and welfare of the global population. It is crucial to have effective measures for prevention, intervention, and monitoring in place to address these evolving and recurring risks, ensuring public health and international security. In countries with limited resources, utilizing recombinant mutation plasmid technology in conjunction with PCR-HRM could help differentiate the existence of novel variants. cDNA synthesis was carried out on 8 nasopharyngeal samples following viral RNA extraction. The P1 segment of the sARs-CoV-2 spike s protein was amplified via conventional PCR. subsequently, PCR products were ligated with the pGEM-T Easy vector to generate eight recombinant sARs-CoV-2 plasmids. Clones containing mutations were sequenced using sanger sequencing and analyzed through PCR-HRM. The P1 segment of the s gene from sARs-CoV-2 was successfully amplified, resulting in 8 recombinant plasmids generated from the 231 bp fragment. PCR-HRM analysis of these recombinant plasmids differentiated three variations within the sARs-CoV-2 plasmid population, each displaying distinct melting temperatures. sanger sequencing identified mutations A112C, G113T, A114G, G214T, and G216C on the P1 segment, validating the PCR-HRM findings of the variations. These mutations led to the detection of L452R or L452M and F486V protein mutations within the protein sequence of the Omicron variant of sARs-CoV-2. In summary, PCR-HRM is a vital and affordable tool for distinguishing sARs-CoV-2 variants utilizing recombinant plasmids as controls.

关键词： Genomic surveillance sARs-CoV-2 PCR-HRM Variants Côte d’Ivoire

On the Geometry of the Anti-canonical Bundle of the Bott–samelson–Demazure–Hansen Varieties

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Acta Mathematica sinica,English series 2024年第8期40卷 1920-1940页

作者： Indranil BIsWAs s.senthamarai KANNAN Pinakinath sAHA school of Mathematics Tata Institute of Fundamental Research1 Homi Bhabha RoadMumbai 400005India Chennai Mathematical Institute Plot H1SIPCOT IT ParkSiruseriKelambakkam603103India

Let G be a semi-simple simply connected algebraic group over the field C of complex *** T be a maximal torus of G,and let W be the Weyl group of G with respect to *** Z(w,i)be the Bott–samelson–Demazure–Hansen variety corresponding to a tuple i associated to a reduced expression of an element w∈*** prove that for the tuple i associated to any reduced expression of a minuscule Weyl group element w,the anti-canonical line bundle on Z(w,i)is globally *** consequence,we prove that Z(w,i)is weak *** that G is a simple algebraic group whose type is different from *** s={α1,...,αn}be the set of simple *** w be such that support of w is equal to *** prove that Z(w,i)is Fano for the tuple i associated to any reduced expression of w if and only if w is a Coxeter element and w^(−1)(Σ_(t=1)^(n)α_(t))∈−s.

关键词： Bott-samelson-Demazure-Hansen variety Coxeter element anti-canonical line bundle Fano weak Fano

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RPLP0/TBP are the most stable reference genes for human dental pulp stem cells under osteogenic differentiation

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World Journal of stem Cells 2024年第6期16卷 656-669页

作者： Daniel B Ferreira Leticia M Gasparoni Cristiane F Bronzeri Katiucia B s Paiva Laboratory of Extracellular Matrix Biology and Cellular Interaction Department of AnatomyInstitute of Biomedical SciencesUniversity of São PauloSão Paulo 05508-000São PauloBrazil

BACKGROUND Validation of the reference gene(RG)stability during experimental analyses is essential for correct quantitative real-time polymerase chain reaction(RT-qPCR)data ***,in an unreliable way,several studies use genes involved in essential cellular functions[glyceraldehyde-3-phosphate dehydro-genase(GAPDH),18s rRNA,andβ-actin]without paying attention to whether they are suitable for such experimental conditions or the reason for choosing such ***,such studies use only one gene when Minimum Information for Publication of Quantitative Real-Time PCR Experiments guidelines recom-mend two or more *** impacts the credibility of these studies and causes dis-tortions in the gene expression *** tissue engineering,the accuracy of gene expression drives the best experimental or therapeutical *** cultivated DPsCs under two conditions:Undifferentiated and osteogenic dif-ferentiation,both for 35 *** evaluated the gene expression of 10 candidates for RGs[ribosomal protein,large,P0(RPLP0),tata-binding protein(TBP),GAPDH,actin beta(ACTB),tubulin(TUB),aminolevulinic acid synthase 1(ALAs1),tyro-sine 3-monooxygenase/tryptophan 5-monooxygenase activation protein,zeta(YWHAZ),eukaryotic translational elongation factor 1 alpha(EF1a),succinate dehydrogenase complex,subunit A,flavoprotein(sDHA),and beta-2-micro-globulin(B2M)]every 7 d(1,7,14,21,28,and 35 d)by *** data were analysed by the four main algorithms,ΔCt method,geNorm,NormFinder,and BestKeeper and ranked by the RefFinder *** subdivided the samples into eight *** All of the data sets from clonogenic and osteogenic samples were analysed using the RefFinder *** final ranking showed RPLP0/TBP as the two most stable RGs and TUB/B2M as the two least stable *** theΔCt method or NormFinder analysis showed TBP/RPLP0 as the two most stable ***,geNorm analysis showed RPLP0/EF1αin the first *** algorithms’two least stab

关键词： Dental pulp stem cells Reference gene Housekeeping gene Endogenous gene Osteogenic differentiation RefFinder

Functional trait profiles and diversity of trees regenerating in disturbed tropical forests and agroforests in Indonesia

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Forest Ecosystems 2022年第3期9卷 323-334页

作者： subekti Rahayu sidiq Pambudi Dikdik Permadi Hesti L.tata Endri Martini saida Rasnovi Hani s.Nuroniah Roeland Kindt Mohamad Nugraha sonya Dewi Meine van Noordwijk World Agroforestry(ICRAF) BogorIndonesia FOERDIA Ministry of Environment and ForestryBogorIndonesia Botany Department Syiah Kuala UniversityBanda AcehIndonesia Plant Production systems Wageningen UniversityWageningenthe Netherlands

A main question in restoration of degraded forests and forest landscapes recovering from logging and fire is what to expect from natural regeneration through surviving propagules in the soil or seed sources and associated dispersal agents from the surrounding landscape mosaic,as alternative to tree *** diversity in secondary forests may be high,but based on newcomer species of low wood density and long-distance,abiotic dispersal *** compiled and analyzed three pairs of case studies(totaling 815 plots and 11.8 ha)of secondary forests recovering from logging,fire and conversion to agroforest in sumatra and Kalimantan(Indonesia)on mineral *** on tree species diversity,wood density frequency distribution(indicative of successional status)and dispersal modes were compared with those of less disturbed comparator forests in the same *** undisturbed lowland dipterocarp forest in Kalimantan had close to 200 species of trees(>10 cm diameter)at a 1-ha sample scale(and 450 at a 10-ha scale).After repeated fires a sample area of 2 ha was needed to reach the same species ***-based logging had little impact on tree species *** rubber agroforest with low-intensity management beyond rubber planting,50 tree species were found at a 1-ha scale and close to 100 species in 3 *** Kalimantan forest after repeated fires had a markedly higher fraction of lowwood-density trees(40%),but otherwise,all forests sampled were similar in overall wood density *** logged forest managed by a local community(village forest)and rubber agroforest in sumatra contained larger fractions of heavy-wood-density *** majority of trees(50%–70%)had birds,bats and primates as dispersal agents in all *** logged forests had higher fractions of autochorous species(15%)compared to other ***(wind-dispersed)species,especially Macaranga lowii,were most common(20%)in lowland dipterocarp *** be

关键词： Agroforestry Dipterocarp Dispersal modes Kalimantan Landscape restoration Natural regeneration sumatra Wood density

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Hypoxia-inducible factor 2α is a negative regulator of osteoblastogenesis and bone mass accrual

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Bone Research 2019年第1期7卷 91-104页

作者： Christophe Merceron Kavitha Ranganathan Elizabeth Wang Zachary tata shreya Makkapati Mohd Parvez Khan Laura Mangiavini Angela Qing Yao Laura Castellini Benjamin Levi Amato J.Giaccia Ernestina schipani Department of Orthopaedic surgery School of MedicineUniversity of MichiganAnn ArborMIUSA Division of Plastic and Reconstructive surgery Department of SurgeryUniversity of MichiganAnn ArborMIUSA Department of Radiation Oncology Stanford University Medical SchoolStanfordCAUSA

Osteoblasts,which are the bone-forming cells,operate in a hypoxic *** transcription factors hypoxia-inducible factor-1α(HIF1)and HIF2 are key mediators of the cellular response to *** are expressed in ***1 is known to be a positive regulator of bone ***,the role of HIF2 in the control osteoblast biology is still poorly *** this study,we used mouse genetics to demonstrate that HIF2 is an inhibitor of osteoblastogenesis and bone mass ***,we provided evidence that HIF2 impairs osteoblast differentiation at least in part,by upregulating the transcription factor *** findings constitute a paradigm shift,as activation of the hypoxia-signaling pathway has traditionally been associated with increased bone formation through *** HIF2 could thus represent a therapeutic approach for the treatment of the low bone mass observed in chronic diseases,osteoporosis,or aging.

关键词： is cells has

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Femtosecond electron microscopy of relativistic electron bunches

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Light(science & Applications) 2023年第6期12卷 1010-1019页

作者： Yang Wan sheroy tata Omri seemann Eitan YLevine slava smartsev Eyal Kroupp Victor Malka Department of Physics of Complex systems Weizmann Institute of ScienceRehovot 7610001Israel

The development of plasma-based accelerators has enabled the generation of very high brightness electron bunches of femtosecond duration,micrometer size and ultralow emittance,crucial for emerging applications including ultrafast detection in material science,laboratory-scale free-electron lasers and compact colliders for high-energy *** precise characterization of the initial bunch parameters is critical to the ability to manipulate the beam properties for downstream *** diagnostic of such ultra-short and high charge density laser-plasma accelerated bunches,however,remains very *** we address this challenge with a novel technique we name as femtosecond ultrarelativistic electron microscopy,which utilizes an electron bunch from another laser-plasma accelerator as a *** contrast to conventional microscopy of using very low-energy electrons,the femtosecond duration and high electron energy of such a probe beam enable it to capture the ultra-intense space-charge fields of the investigated bunch and to reconstruct the charge distribution with very high spatiotemporal resolution,all in a single *** the experiment presented here we have used this technique to study the shape of a laser-plasma accelerated electron beam,its asymmetry due to the drive laser polarization,and its beam evolution as it exits the *** anticipate that this method will significantly advance the understanding of complex beam-plasma dynamics and will also provide a powerful new tool for real-time optimization of plasma accelerators.

关键词： relativistic utilize precise

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超速离心分离胶乳各部分中蛋白质的分布

热带作物译丛 1982年第2期 33-34页

作者： s·J·tata 林辰涛

据 Cook 等的介绍,全氮在离心胶乳的橡胶部分、乳清部分和底层部分中的分布率大致分别为34%、35%和31%。据Archer 等的估计,胶乳中蛋白质的总量为1%,其中的20%吸附于橡胶粒子表面,约66%溶解在 C 乳清中,其余40%分布在底层部分。后来 Arc... 详细信息

据 Cook 等的介绍,全氮在离心胶乳的橡胶部分、乳清部分和底层部分中的分布率大致分别为34%、35%和31%。据Archer 等的估计,胶乳中蛋白质的总量为1%,其中的20%吸附于橡胶粒子表面,约66%溶解在 C 乳清中,其余40%分布在底层部分。后来 Archer 报道说,新鲜胶乳中蛋白质的总含量为1%,其中约20%分布在橡胶部分,20%在底层部分,

关键词：超速离心蛋白质胶乳

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惹祸旋风

快乐青春 2006年第8期 93-96页

作者： tata睛

　　No.1　　"I love you,依依,从我第一次见到你就对你……"　　"stop!我不喜欢你!"好绝情的否定句啊!蓝依依叹了口气转身就走了--在s中那棵情人树下又一个GG被蓝依依拒绝了.……

关键词：否定句情人