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How does the stand structure of treeline-forming species shape the treeline ecotone in different regions of the Nepal Himalayas?

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Journal of Mountain Science 2020年第10期17卷 2354-2368页

作者： parveen k.chhetri Raju BISTA krishna B.SHRESTHA Department of Earth Science and Geography California State UniversityDominguez HillsCarsonCalifornia90747USA Department of Biological Sciences University of BergenPO Box 7803N-5020BergenNorway

Stand structure dynamics are considered as major happenings in any forest as a response to environmental ***,this important topic is underrepresented in the treeline studies in the Nepal *** aimed to investigate site-as well as species-specific changes in morphometric features(basal diameter,crown cover,density,and height)along the elevational gradient across treeline ecotones in response to recent environmental *** stand structure characteristics of Abies spectabilis,Pinus wallichiana,and Betula utilis across the treeline ecotone of three study sites in Eastern(Barun),Central(Manang),and Western(Dhorpatan)Nepal were analyzed to elucidate structural ***,eight transects(20 m×(60–250 m))across the treeline ecotone were *** of all life forms,trees(>2 m),saplings(0.5–2 m),and seedlings(kes,in further studies,the incorporation of the tree’s morphometric adaptation traits,phenotypic plasticity,and interactions between species genotype and the environment.

关键词： Climate change Morphometry Nepal Himalayas Stand structure Treeline Tree-rings

Topography and human disturbances are major controlling factors in treeline pattern at Barun and Manang area in the Nepal Himalaya

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Journal of Mountain Science 2017年第1期14卷 119-127页

作者： parveen k.chhetri krishna B.SHRESTHA David M.CAIRNS Department of Geography Texas A&M University College Station TX 77840 USA UiB Global Jekteviksbakken 31 PO Box 7800 5020 Bergen Norway

The alpine treeline ecotone is an important component of mountain ecosystems of the Nepal Himalaya; it plays a vital role in the livelihood of indigenous people,and provides ecosystem services. However,the region faces a problem of paucity of data on treeline characteristics at the regional and landscape scales. Therefore,we used Remote Sensing(RS),and Geographic Information Science(GIS) approaches to investigate cross-scale interactions in the treeline ecotone. Additionally,European Space Agency land cover map,International Center for Integrated Mountain Development(ICIMOD) land cover map,ecological map of Nepal,and United States Geological Survey Shuttle Radar Topography Mission-Digital Elevation Model were used to analyze treeline pattern at the regional scale. Digital Globe high-resolution satellite imagery of Barun(eastern Nepal) and Manang(central Nepal) were used to study treeline patterns at the landscape scale. Treeline elevation ranges from 3300-4300 m above sea level. Abies spectabilis,Betula utilis,and Pinus wallichiana are the main treeline-forming species in the Nepal Himalaya. There is an east to west treeline elevationgradient at the regional scale. No slope exposure is observed at the regional scale; however,at the landscape scale,slope exposure is present only in a disturbed area(Manang). Topography and human disturbance are the main treeline controlling factor in Barun and Manang respectively.

关键词：喜马拉雅山区控制因素人为干扰尼泊尔树线地形生态系统服务高分辨率卫星影像

Effect of cooling media on bead geometry,microstructure,and mechanical properties of wire arc additive manufactured IN718 alloy

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Advances in Manufacturing 2024年第1期12卷 124-149页

作者： parveen kumar Satish kumar Sharma Ratnesh kumar Raj Singh Department of Mechanical Engineering Thapar Institute of Engineering and TechnologyPatialaPunjab147004India

This work aims to present and explore thermal management techniques for the wire arc additive manufacturing(WAAM)of IN718 *** heat can be mitigated via air or water *** this study,the material was deposited under four different heat-input conditions with air or water *** air cooling,the layer is deposited in a normal atmospheric air environment,whereas with water cooling,the material is deposited inside a water tank by varying the water *** validate the air and water cooling thermal management techniques,IN718 single-pass and multilayer linear walls were deposited using the bidirectional gas metal arc welding based WAAM setup under four different heat input *** the deposition of single layers,the temperature profiles were recorded,and the geometric and microstructural features were *** multilayer wall structures,the mechanical properties(hardness,tensile strength,and elongation)were determined and assessed using the corresponding microstructural features explored through scanning electron microscopy(SEM),energy dispersive spectroscopy(EDS),and electron backscatter diffraction(EBSD)*** microstructure observed through SEM analysis in the building direction was found to be nonhomogenous compared with that in the deposition ***,water cooling was found to govern bead characteristics,such as wall width and *** grain size and anisotropy of the mechanical properties also decreased in the water-cooled ***,water cooling is an economical and efficient method to mitigate excessive heat accumulation in WAAM-deposited IN718.

关键词： Air cooling Water cooling IN718 Bead characteristics Microstructure Electron backscatter diffraction(EBSD)

Genome-wide identification and expression profiling of photosystem II(PsbX)gene family in upland cotton(Gossypium hirsutum L.)

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Journal of Cotton Research 2024年第1期7卷 1-14页

作者： RAZA Irum parveen Abida AHMAD Adeel HU Daowu PAN Zhaoe ALI Imran DU Xiongming Institute of Cotton Research Chinese Academy of Agricultural SciencesNational Key Laboratory of Cotton Bio-Breeding and Integrated UtilizationAnyangHenan 455000China Department of Biotechnology and Genetic Engineering Kohat University of Science and TechnologyKohatPakistan Department of Botany Kohat University of Science and TechnologyKohatPakistan.

Background Photosystem II(PSII)constitutes an intricate assembly of protein pigments,featuring extrinsic and intrinsic polypeptides within the photosynthetic *** low-molecular-weight transmembrane protein PsbX has been identified in PSII,which is associated with the oxygen-evolving *** expression of PsbX gene protein is regulated by ***’s central role involves the regulation of PSII,facilitating the binding of quinone molecules to the Qb(PsbA)site,and it additionally plays a crucial role in optimizing the efficiency of *** these insights,a comprehensive understanding of the PsbX gene’s functions has remained *** In this study,we identified ten PsbX genes in Gossypium hirsutum *** phylogenetic analysis results showed that 40 genes from nine species were classified into one *** resulting sequence logos exhibited substantial conservation across the N and C terminals at multiple sites among all Gossypium ***,the ortholo-gous/paralogous,ka/ks ratio revealed that cotton PsbX genes subjected to positive as well as purifying selection pressure might lead to limited divergence,which resulted in the whole genome and segmental *** expression patterns of GhPsbX genes exhibited variations across specific tissues,as indicated by the ***,the expression of GhPsbX genes could potentially be regulated in response to salt,intense light,and drought ***,GhPsbX genes may play a significant role in the modulation of photosynthesis under adverse abiotic *** We examined the structure and function of PsbX gene family very first by using comparative genom-ics and systems biology approaches in *** seems that PsbX gene family plays a vital role during the growth and development of cotton under stress ***,the results of this study provide basic information to unveil the molecular and physiological function of PsbX genes of cotton plan

关键词： Photosystem Phylogenetic Synteny RNA seq Gene expression Orthologous

Predicting upslope expansion of sub-alpine forest in the Makalu Barun National Park, Eastern Nepal, with a hybrid cartographic model

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Journal of Forestry Research 2018年第1期29卷 129-137页

作者： parveen kumar chhetri Department of Geography Texas A&M UniversityCollege Station

The natural upper boundary of a forest（forest line） in mountain environments is an indicator of climate conditions. An increase in global average temperatures has resulted in an upward advance of the forest line. This advance may result in fragmentation of the alpine ecosystem and a loss of biodiversity. Therefore, it is important to identify potential areas where current forests can advance under scenarios of future climate change. I used expert knowledge and cartographic modeling to create a hybrid cartographic model considering five topographic variables to predict areas where forest line can expand in the *** prediction accuracy of the model is around 82%. The model is able to predict areas above the current forest line that are suitable or unsuitable for future forest *** inclusion of high-resolution satellite imagery and digital elevation models, as well as field-based information into the model can help to improve the model accuracy.

关键词： Climate change Forest line Forest line advance Hybrid cartographic model Makalu Barun National Park

Contemporary and Historic Population Structure of Abies spectabilis at Treeline in Barun Valley,Eastern Nepal Himalaya

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Journal of Mountain Science 2015年第3期12卷 558-570页

作者： parveen kumar chhetri David M.CAIRNS Department of Geography Texas A&M UniversityCollege Station

Treeline ecotone dynamics of Abies spectabilis(D. Don) Mirb. in the Barun valley,Makalu Barun National Park, eastern Nepal Himalaya were studied by establishing seven plots(20 m ×variable length) from the forestline to the tree species limit: three plots on the south- and north-facing slopes each(S1-S3, N1-N3), and one plot on the eastfacing slope(E) in the relatively undisturbed forests.A dendroecological method was used to study treeline advance rate and recruitment pattern. In all the plots,most trees established in the early 20 th century, and establishment in the second half of the 20 th century was confined to the forestline area. Treeline position has not advanced substantially in the Barun valley,with only 22 m average elevational shift in the last 130 years, and with average current shifting rate of 14cm/yr. Moreover, no significant relationship was found between tree age and elevation on the south-,north-, and east-facing slopes. The number of seedlings and saplings in near the treeline area was negligible compared to that near the forestline ***, A. spectabilis treeline response to the temperature change was slow, despite the increasing temperature trend in the region. Beside the temperature change, factors such as high inter-annual variability in temperature, dense shrub cover, and local topography also play an important role in treeline advance and controlling recruitment pattern above the treeline.

关键词：喜马拉雅尼泊尔树线人口结构润谷冷杉历史温度升高

Dendroclimatic response of Abies spectabilis at treeline ecotone of Barun Valley, eastern Nepal Himalaya

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Journal of Forestry Research 2016年第5期27卷 1163-1170页

作者： parveen kumar chhetri David M.Cairns Department of Geography Texas A&M UniversityCollege StationTX 77843-3147USA

A dendroclimatic study was conducted in the treeline ecotone of Barun Valley, eastern Nepal, to determine the tree-ring climate response and ring width trend of Abies spectabilis. A 160-year-old chronology, from 1850 to 2010, was developed from 38 tree-ring samples. No higher growth in recent decades was observed in tree-ring width in this area. The mean temperature of the current year in February and in the combined winter months of December, January, and February showed significant positive correlation with tree-ring width, although no significant correlation was found between tree-ring width and the precipitation pattern of the region. This tree-ring climate response result is different from that in other studies in Nepal, which could be attributed to location and elevation.

关键词： spectabilis Dendroclimatology Treeline ecotone Abies Climate response Tree-ring width

Deep Learning Framework for Classification of Emoji Based Sentiments

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Computers, Materials & Continua 2022年第8期72卷 3145-3158页

作者： Nighat parveen Shaikh Mumtaz Hussain Mahar Shah Abdul Latif University Khairpur77150Pakistan

Recent patterns of human sentiments are highly influenced by emoji based sentiments(EBS).Social media users are widely using emoji based sentiments(EBS)in between text messages,tweets and *** tiny pictures of emoji contains sufficient information to be considered for construction of classification model;but due to the wide range of dissimilar,heterogynous and complex patterns of emoji with similarmeanings(SM)have become one of the significant research areas of machine *** paper proposes an approach to provide meticulous assistance to social media application(SMA)users to classify the EBS *** methodology consists upon three layerswhere first layer deals with data cleaning and feature selection techniques to detect dissimilar emoji patterns(DEP)with similar meanings(SM).In first sub step we input set of emoji,in second sub step every emoji has to qualify user defined threshold,in third sub step algorithm detects every emoji by considering as objects and in fourth step emoji images are cropped,after data cleaning these tiny images are saved as emoji *** second step we build classification model by using convolutional neural networks(CNN)to explore hidden knowledge of emoji *** third step we present results visualization by using confusion matrix and other *** paper contributes(1)data cleaning method to detect EBS;(2)highest classification accuracy for emoji classification measured as 97.63%.

关键词： Deep learning machine vision convolutional neural networks social media emoji based sentiments

Experimental investigation and prediction of free fall jet scouring using machine learning models

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International Journal of Sediment Research 2023年第3期38卷 405-420页

作者： Farzin Salmasi parveen Sihag John Abraham Meysam Nouri Department of Water Engineering Faculty of Agriculture University of Tabriz Department of Civil Engineering Chandigarh University School of Engineering University of St.Thomas Minnesota Department of Water Engineering Faculty of Agriculture Urmia University Department of Civil Engineering Saeb University

The current study deals with the depth of scour at the location of impact between a free fall jet and a riverbed. The current study is based on extensive laboratory experiments that were designed to mimic full-scale behavior. The literature review shows that relations among hydraulic parameters for predicting the depth of scour are complex; therefore, six artificial intelligence techniques are used in the current study to capture these complex relation. A total of 120 observations are used for the analysis. Results from the experiments show that with increasing downstream water depth(h), the impinging jet causes increasingly turbulent currents and large vortices that increase the scouring of the riverbed. Increasing discharge per unit width(q) enhances the relative scour depth(D/H) while increasing the average diameter of the riverbed materials(d) decreases D/H, where D is maximum scour depth and H is the height of the falling jet. With increasing(particle Froude number Fr), the relative scour depth *** the current study the prediction accuracy of Gene Expression Programming(GEP), Multivariate Adaptive Regression Spline(MARS), M5P Tree, Random Forest(RF), Random Tree(RT), and Reduces Error Pruning Tree(REP Tree) techniques are evaluated using the relative scour depth(D/(H-h)). The performance evaluation indices and graphical methods suggest that the GEP based model is more accurate than other prediction methods for the relative scour depth with a coefficient of determination(R2) equal to 0.8330 and 0.8270, a mean absolute error(MAE) equal to 0.1125 and 0.0902, root mean square error(RMSE) values of 0.1463 and 0.1116, and Willmott’s Index(WI) equal to 0.8998 and 0.9014, for the training and testing stages.

关键词： Free jet Scour Gene Expression Programming (GEP) Random Forest (RF) Multivariate Adaptive Regression Spline (MARS)