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Micro-site Conditions of Epiphytic Orchids in a Human Impact Gradient in Kathmandu Valley, Nepal

Journal of Mountain Science 2012年第3期9卷 331-342页

作者： yagya prasad adhikari Anton FISCHER Hagen Siegfried FISCHER Geobotany Department of Ecology and Ecosystem Management Technische Universitt München Hans-Carl-von-Carlowitz-Platz 2 D-85354 Freising Germany

We studied distribution and site conditions of epiphytic orchids in a gradient of human interference in Kathmandu valley, central Nepal. The aim was to understand the recent distribution pattern of epiphytic orchids, with respect to (i) the micro-site conditions and (ii) the type and intensity of land use. The occurrence of epiphytic orchids was recorded for a grid with 1.5 km cell size. The cells represent different types and intensities of human impact. Site factors such as bark rugosity, bark pH, diameter at breast height (dbh; 1.3 m) of host trees, exposure to wind and sunlight intensity were recorded. With regard to the species richness and abundance of epiphytic orchids, we compared different human impact categories from very strong human impact (settlement area) to very low human impact (national park). Remote sensing was used for a supervised classification of land cover. Ficus religiosa turned out to be the most important host species for orchids in urban areas, while Schima wallichii and Alnus nepalensis significantly host orchids in the other categories. Both species richness and abundance of epiphytic orchids were significantly higher under very low human impact (forest in national park) and also some remaining patches of primary forest than the other regions. Micro-climate is crucial for orchid populations. Host bark pH, bark rugosity, sunlight intensity and host exposure were significantly different for all human impact categories in order to harbour epiphytic orchid species. Habitats with a mixture of mature trees are suitable and essential for the conservation of viable populations of epiphytic orchids in settled areas. The study reveals that to improve the population size of orchids it is essential for future urban forestry to: (i) Protect old trees as carriers of existing epiphytic orchid diversity, (ii) protect medium old trees to ensure that they may become old trees, (iii) plant new host trees for the future, (iv) plant in groups instead of sing

关键词： Human impact Host tree Micro-climate Epiphytic orchids Remote sensing Conservation Nepal

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Composition of forests and vegetation in the Kailash Sacred Landscape,Nepal

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Journal of Forestry Research 2020年第5期31卷 1625-1635页

作者： Ripu Mardhan Kunwar Maria Fadiman Tobin Hindle Madan Krishna Suwal yagya prasad adhikari Kedar Baral Rainer Bussmann Department of Geosciences Florida Atlantic University777 Glades RoadBoca RatonFL 33431USA Department of Geography University of BergenFosswinckelsgate 6P.O.Box 78025020 BergenNorway Department of Biogeography University of BayreuthUniversitatsstr.3095447 BayreuthGermany Department of Forests Kathmandu 44600Nepal Ilia State University Kakutsa Cholokashvili Ave 3/50162 TbilisiRepublic of Georgia

A total of 141 quadrats were sampled using stratified random sampling to study forest,environment and human interactions along an elevation gradient 1800 to 3665 m at the remote Kailash Sacred Landscape,*** forest types were identified,including Laurel-Oak to Rhododendron to Blue pine,comprising 191 species including 60 useful from 166 genera and 87 *** environmental variables elevation,slope,and temperature were significant(p<0.001)in determining the composition and distribution of forest *** of large numbers of useful plants along with diverse forest and vegetation types suggest a strong association between the culture of local villages and nature *** to changes in climate,socio-culture and land-use,forest degradation is expected to accelerate,thus forcing government and indigenous community forest management measures to acknowledge human,cultural and environmental variables for sustainable forest management.

关键词： Phyto-sociological assessment Environmental factors Forest types Culture Kailash Sacred Landscape Nepal

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Epiphytic orchids and their ecological niche under anthropogenic influence in central Himalayas,Nepal

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Journal of Mountain Science 2016年第5期13卷 774-784页

作者： adhikari yagya prasad FISCHER Anton FISCHER Hagen Siegfried Geobotany Department of Ecology and Ecosystem ManagementTechnische Universit?t München

The survival chance of epiphytie orchids today not only depends on the natural site conditions required by the orchids but also on anthropogenic changes in site conditions. This study answers two questions：（1） What is the ecological niche of the different epiphytic orchid species？（2） What are the ecological factors that threaten epiphytic orchid＇s population under anthropogenic disturbances？ Our study area was the Kathmandu valley, Nepal, with its subtropical forest. We established 156 systematically selected sampling points in the Kathmandu area covering different types of ecosystems under human impacts such as densely populated area, agricultural land, mixed agricultural and settled area, old tree patches, and a natural forest in a national park. The ecological niche of the orchid species was analyzed with a principal component analysis （PCA）. The correlations between the different site factors were statistically significant. Spearman＇s rank correlation matrices showed that the variables land-use intensities with altitude, and height with diameter in breast height （dbh） of host had the highest significant positive correlation coefficient （0.67 and 0.64 respectively）. On the other hand, host bark pH and altitude as well as land use had a significantly strong negative correlation coefficient （-0.80 and -0.61, respectively）. Different epiphytic orchid species interact differently with the given set of environmental factors： for occurrence of Vanda cristata there is no single environmental factor of special influence, while for Rhynehostylis retusa high bark pH and high light availability are important. First two axis of the PCA explained more than 50% of the total variance. Most orchid species occupy a specific, narrow niche in this ecological space. The main causes of anthropogenie influence of orchid population in the Kathmandu Valley are loss of adequate host trees （species and size） and increasing air pollution, resulting in increasing host bark pH.

关键词： Host characteristics Epiphytic orchids Anthropogenic disturbances Canopy ecosystem Ecological niche Himalayas

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Diversity, composition and host-species relationships of epiphytic orchids and ferns in two forests in Nepal

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Journal of Mountain Science 2017年第6期14卷 1065-1075页

作者： yagya P. adhikari Anton FISCHER Hagen S.FISCHER Maan B.ROKAYA Prakash BHATTARAI Axel GRUPPE Geobotany Department of Ecology and Ecosystem Management Technische Universitat Munchen Hans-Carl-von-Carlowitz-Platz 2 85354 Freising Germany Institute of Botany Czech Academy of Sciences Zamek 1 CZ-252 43 Pruhonice Czech Republic Department of Biodiversity Research Global Change Research Institute Czech Academy of Sciences Belidla 4a 60300 Brno Czech Republic Department of Biology University of Bergen Postholes 7803 N-5020 Bergen Norway Zoology - Entomology Department of Animal Science Technische Universitat Munchen Hans-Carl-von-Carlowitz-Platz 85354 Freising Germany

Epiphytic plant species are an important part of biological diversity. It is therefore essential to understand the distribution pattern and the factors influencing such patterns. The present study is aimed at observing the patterns of species richness, abundances and species composition of epiphytic orchids and ferns in two subtropical forests in Nepal. We also studied the relationship of host plants(Schima wallichii and Quercus lanata) and epiphyte species. Data were collected in Naudhara community forest(CF) and the national forest(NF) in Shivapuri Nagarjun National Park. The data were analyzed using univariate and multivariate tests. In total, we recorded 41 species of epiphytes(33 orchid and 8 fern species). Orchid species abundance is significantlyhigher in CF compared to NF. Orchid species richness and abundance increased with increasing southern aspect whereas it decreased with increasing canopy cover, and fern species richness increased with host bark roughness. Orchid abundance was positively correlated with increasing bark p H, stem size, tree age and tree height and negatively correlated with increasing steepness of the area. Likewise, fern abundances were high in places with high canopy cover, trees that were tall and big, but decreased with increasing altitude and southern aspect. The composition of the orchid and fern species was affected by altitude, aspect, canopy cover, DBH, number of forks and forest management types. We showed that the diversity of orchid and fern epiphytes is influenced by host characteristics as well as host types. The most important pre-requisite for a high epiphyte biodiversity is the presence of oldrespectively tall trees, independent of the recent protection status. This means:(i) for protection, *** the frame of the national park declaration, such areas should be used which host such old tall trees;and(ii) also in managed forests and even in intensively used landscapes epiphytes can be protected by letting a certain numb

关键词： Environmental factors Epiphytes Large trees Indicator species Multivariate and univariate analyses Permutations tests

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Disaster Risk Reduction (DRR) Education from Social Disciplinary Theoretical Perspectives

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Open Journal of Earthquake Research 2024年第1期13卷 41-83页

作者： yagya Raj Pant School of Health New Zealand School of Education Auckland New Zealand

Disaster is a social phenomenon. The occurrence and impacts of disasters including the education sector can be studied through a social problem lens. This paper draws meaning and understanding of DRR education using the sociological disciplinary framework in a detailed qualitative case study of three schools as they responded to the devastating Gorakha earthquake in 2015 and other disasters in Nepal. This paper considers the three sub-disciplines of sociology: the sociology of disaster, the sociology of education and the sociology of education governance in a development context. These sub-disciplines are nested together to analyse social, political and historical factors and their relationships which are helpful to identify risks and vulnerabilities in the education sector in Nepal. These are the major areas to explore the disaster context and needs of context-specific education acts (hereafter DRR education) to minimise the potential risks of disasters. The article concludes that the social disciplinary framework is significantly useful to analyse DRR education provisions and implications of education governance to mobilise school in disaster preparedness, response and recovery.

关键词： Sociology of Disaster Social Vulnerability Disaster Governance Education Governance Disaster Risk Reduction (DRR) Education Pluri-Scalar Education Governance

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Preparing Youth for Disasters: The Need for a Contextualised Disaster Risk Reduction Curriculum in Schools

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Open Journal of Earthquake Research 2024年第4期13卷 183-217页

作者： yagya Raj Pant New Zealand School of Education Auckland New Zealand

This study draws from detailed qualitative case studies of three schools that practise disaster risk reduction (DRR) education initiatives in their curriculum in Nepal. Using curriculum mapping and discourse analysis, it aims to elaborate the significance of relevant disaster risk reduction (DRR) content in school curriculum to prepare youths for disaster response and recovery. It elaborates the nature of the current DRR content covered in curricula and textbooks and provides suggestions to address the identified disaster-related issues in the school curriculum. It further elaborates that incorporation of local and contextualised DRR content in school curricula contributes to the establishment of the “culture of resilience” in disaster prone context like Nepal. It concludes that more organised and holistic approach is essential to develop disaster and management knowledge, skills and attitudes to youths.

关键词： Disaster Risk Reduction Curriculum Disaster Prevention Disaster Mitigation Disaster Response Disaster Recovery

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Participation in Disaster Risk Reduction (DRR) Education: Analysing the Practices, Issues and Challenges

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Open Journal of Earthquake Research 2023年第4期12卷 198-222页

作者： yagya Raj Pant New Zealand School of Education Auckland New Zealand

This article draws from detailed qualitative case studies of three schools as they responded to the devastating Gorakha earthquake in 2015 and other disasters in Nepal. Using Arnstein’s [1] ladder of participation, it explores nature and importance of participation to address the local disaster context. Along with Robertson et al.’s [2] pluri-scalar education governance framework, it also discusses the current forms of participation from various stakeholders specifically within the education system. The article analyses the reasons for stakeholders’ participation in DRR initiatives. It also explains the purpose of the participation, challenges of participation in DRR education, and highlights some key messages around what the study’s data says about participation in DRR education. The article concludes with the idea that curriculum participation is a crucial element to mobilise schools for their disaster preparedness, response and recovery journeys.

关键词： DRR Education Education Governance Participation Ownership

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A machine learning driven 3D+1D model for efficient characterization of proton exchange membrane fuel cells

Energy and AI

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Energy and AI 2024年第3期17卷 281-294页

作者： Yuwei Pan Haijun Ruan Billy Wu yagya N.Regmi Huizhi Wang Nigel P.Brandon Department of Earth Science and Engineering Imperial College LondonLondon SW72AZUK Dyson School of Design Engineering Imperial College LondonLondon SW72AZUK Centre for E-Mobility and Clean Growth Coventry UniversityCoventry CV15FBUK Manchester Fuel Cell Innovation Centre Department of Natural SciencesManchester Metropolitan UniversityManchester M15GDUK Department of Mechanical Engineering Imperial College LondonLondon SW72AZUK

The computational demands of 3D continuum models for proton exchange membrane fuel cells remain substantial. One prevalent approach is the hierarchical model combining a 2D/3D flow field with a 1D sub-model for the catalyst layers and membrane. However, existing studies often simplify the 1D domain to a linearized 0D lumped model, potentially resulting in significant errors at high loads. In this study, we present a computationally efficient neural network driven 3D+1D model for proton exchange membrane fuel cells. The 3D sub-model captures transport in the gas channels and gas diffusion layers and is coupled with a 1D electrochemical sub-model for microporous layers, membrane, and catalyst layers. To reduce computational intensity of the full 1D description, a neural network surrogates the 1D electrochemical sub-model for coupling with the 3D domain. Trained by model-generated large synthetic datasets, the neural network achieves root mean square errors of less than 0.2%. The model is validated against experimental results under various relative humidities. It is then employed to investigate the nonlinear distribution of internal states under different operating conditions. With the neural network operating at 0.5% of the computing cost of the 1D sub-model, the hybrid model preserves a detailed and nonlinear representation of the internal fuel cell states while maintaining computational costs comparable to conventional 3D+0D models. The presented hybrid data-driven and physical modeling framework offers high accuracy and computing speed across a broad spectrum of operating conditions, potentially aiding the rapid optimization of both the membrane electrode assembly and the gas channel geometry.

关键词： Proton exchange membrane fuel cell Hierarchical model Neural network Hybrid model

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Metric Based Testability Estimation Model for Object Oriented Design: Quality Perspective

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Journal of Software Engineering and Applications 2015年第4期8卷 234-243页

作者： Mahfuzul Huda yagya Dutt Sharma Arya Mahmoodul Hasan Khan Department of Computer Science & Engineering Invertis University Bareilly India Department of Computer Science and Engineering IET Lucknow India

The quality factor of class diagram is critical because it has significant influence on overall quality of the product, delivered finally. Testability has been recognized as a key factor to software quality. Estimating testability at design stage is a criterion of crucial significance for software designers to make the design more testable. Taking view of this fact, this paper identifies testability factors namely effectiveness and reusability and establishes the correlation among testability, effectiveness and reusability and justifies the correlation with the help of statistical measures. Moreover study developed metric based testability estimation model and developed model has been validated using experimental test. Subsequently, research integrates the empirical validation of the developed model for high level acceptance. Finally a hypothesis test performs by the two standards to test the significance of correlation.

关键词： Testability Testability Model Effectiveness Reusability Testability Factors Design Phase

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Modes of failure with fractional flow reserve guidewires:Insights from the manufacturer and user facility device experience database

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World Journal of Cardiology 2021年第7期13卷 223-229页

作者： Nauman Khalid yagya Pandey Umair Khalid Hassan Kamran Jason P Wermers Lovely Chhabra Mahboob Alam Hani Jneid Waleed Tallat Kayani Department of Interventional Cardiology St.Francis Medical CenterMonroeLA 71201United States Department of Internal Medicine Baylor College of MedicineHoustonTX 77030United States Department of Interventional Cardiology Michael E.DeBakey VA Medical CenterHoustonTX 77030United States Department of Interventional Cardiology Baylor College of MedicineHoustonTX 77030United States Health Sciences University of Maryland Graduate SchoolBaltimoreMD 21201United States

BACKGROUND Fractional flow reserve(FFR)measurement is commonly used in the cardiac catheterization laboratory to assess the functional significance of coronary arterial *** real-world data on complications and modes of failure of FFR guidewires are *** To characterize these outcomes by analyzing the post-marketing surveillance data from the United States Food and Drug Administration Manufacturer and User Facility Device Experience(MAUDE)database for commonly used FFR *** The MAUDE database was queried from January 2010 through April 2020 for 3 FFR guidewires[PressureWireTM X(Abbott),CometTM(Boston Scientific),and VerrataTM(Philips)]by searching for the following events:“Injury”,“malfunction”,“death”,and“other”.This yielded 544 *** excluding incomplete reports,486 reports were *** Guidewire tip fracture was the most commonly reported mode of failure,in 174(35.8%)cases followed by guidewire kinking(n=152,31.3%),communication failure(n=141,29.0%),and shaft fracture(n=67,13.8%).In total,133(27.4%)device failures resulted in patient adverse *** most common adverse event was retained guidewire tip,in 71(53.4%)cases,followed by freshly deployed stent dislodgment(n=26,19.6%)and coronary artery dissection(n=23,17.3%).Seven deaths were *** FFR guidewire failures can occur because of various mechanisms and cause patient adverse *** MAUDE database serves as an important platform for improved collaboration among clinicians,device manufacturers,and regulators to improve device performance and optimize patient *** analysis provides mechanistic insights of FFR guidewire failure and associated adverse events but cannot verify causality or provide a comparison among different guidewires.

关键词： Fractional flow reserve Coronary guidewire Adverse events Modes of failure Food and Drug Administration Manufacturer and user facility device experience

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