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Elevational distribution of butterflies in the Himalayas: a case study from Langtang National Park, Nepal

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Journal of Mountain Science 2017年第7期14卷 1384-1390页

作者： Ranjit PANDEY Kapil K KHADKA Anuj GHIMIRE Puja JHA Umesh PATHAK oklahoma State university Department of Integrative Biology university of arkansas Department of Biological Sciences Tribhuvan university Central Department of Zoology oklahoma State university Tribhuvan university Central Department of Environmental Sciences

Mountain ecosystems are relatively more vulnerable to climate change since human induced climate change is projected to be higher at high altitudes and latitudes. Climate change induced effects related to glacial response and water hazards have been documented in the Himalayas in recent years, yet studies regarding species' response to climate change are largely lacking from the mountains and Himalayas of Nepal. Changes in distribution and latitudinal/altitudinal range shift, which are primary adaptive responses to climate change in many species,are largely unknown due to unavailability of adequate data from the past. In this study, we explored the elevational distribution of butterflies in Langtang Village Development Committee(VDC) of Langtang National park; a park located in the high altitudes of Nepal. We found a decreasing species richness pattern along the elevational gradient considered ***, elevation did not appear to have a significant effect on the altitudinal distribution ofbutterflies at family level. Also, distribution of butterflies in the area was independent of habitat type,at family level. Besides, we employed indicator group analysis(at family level) and noticed that butterfly families Papilionidae, Riodinidae, and Nymphalidae are significantly associated to high, medium and low elevational zone making them indicator butterfly family for those elevational zones, respectively. We expect that this study could serve as a baseline information for future studies regarding climate change effects and range shifts and provide avenues for further exploration of butterflies in the high altitudes of Nepal.

关键词： Butterflies Indicator species Nepal Range shift Climate change Himalayas

Improved optical enhancement using double-width plasmonic gratings with nanogaps

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Photonics Research 2016年第5期4卷 173-180页

作者： Ahmad A.Darweesh Stephen J.Bauman Joseph B.Herzog Microelectronics-Photonics Graduate Program University of Arkansas Department of Physics University of Arkansas

Plasmonic grating structures have been shown effective at increasing near-field optical enhancement. A doublewidth plasmonic grating design is introduced, where each period has two alternating metal widths separated by a nanogap. With this new design, analysis has shown that plasmonic resonances couple between each metal section,resulting in even greater optical enhancement compared with single-width gratings. The geometry that gives the greatest optical enhancement has been determined with a computational model. This work demonstrates that the increased enhancement is due to hybridized modes that couple between the two grating segments.

关键词： Improved optical enhancement using double-width plasmonic gratings with nanogaps nm

Attribution of Fano resonant features to plasmonic particle size, lattice constant, and dielectric wavenumber in square nanoparticle lattices

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Photonics Research 2014年第1期2卷 15-23页

作者： Drew DeJarnette Justin Norman D.Keith Roper Microelectronics and Photonics Graduate Program University of ArkansasFayettevilleArkansas 72701USA Department of Chemical Engineering University of ArkansasFayettevilleArkansas 72701USA

Fano resonances between plasmons and diffracted light offer tunable energies and locales,but attribution of Fano resonance features to geometry and physicochemistry of metal nanostructures and adjacent dielectrics has been confounded by complexity and computational *** work shows predictable modal shifts of Fano resonance in square lattices of plasmonic nanostructures can be attributed directly to changes in medium wavenumber,particle size,and lattice constant that alter plasmon polarizability and diffractive *** 45 to 80 nm radius particles,a window of lattice constants that support Fano resonances is identified in a range from 500 to 900 *** constants that support high intensity resonances are determined by individual particle polarizability and medium *** resonance wavelengths redshift from diffracted photon energies as local refractive index(RI)changes due to coupling with particle polarizability in the *** sensitivities for quadrupole,dipole,and Fano resonances are 150,348,and 541 nm,respectively,per RI *** resonance intensity may be enhanced more than tenfold by selecting nanoparticle sizes and lattice *** quantitative effects of such parametric changes are rapidly and intuitively distinguished using a semi-analytic approach,consisting of an exact expression for particle polarizability,a trigonometric description of diffraction,and a semianalytical coupled dipole approximation.

关键词： lattice particle wave

Role of phenotypic plasticity in morphological differentiation between watersnake populations

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Integrative Zoology 2020年第4期15卷 329-337页

作者： Ian T.CLIFTON Jeremy D.CHAMBERLAIN Matthew E.GIFFORD Department of Biology University of Central ArkansasConwayArkansasUSA Department of Biology Southern Arkansas UniversityMagnoliaArkansasUSA Department of Environmental Sciences University of ToledoToledoOhioUSA

An individual’s morphology is shaped by the environmental pressures it experiences,and the resulting morphological response is the culmination of both genetic factors and environmental(non-genetic)conditions experienced early in its life(*** plasticity).The role that phenotypic plasticity plays in shaping phenotypes is important,but evidence for its influence is often *** exposed female neonate diamond-backed watersnakes(Nerodia rhombifer)from populations experiencing different prey-size regimes to different feeding treatments to test the influence of phenotypic plasticity in shaping trophic *** found that snakes in a large-prey treatment from a population frequently encountering large prey exhibited a higher growth rate in body size than individuals in a small-prey treatment from the same *** pattern was not observed in snakes from a population that regularly encounters small *** also found that regardless of treatment,snakes from the smallprey population were smaller at birth than snakes from the large-prey population and remained so throughout the *** results suggest that the ability to plastically respond to environmental pressures may be population*** results also indicate a genetic predisposition towards larger body sizes in a population where large prey items are more common.

关键词： common garden diamond-backed watersnake local adaptation phenotypic plasticity trophic morphology

Photoredox-catalyzed [4+2] annulation of cyclobutylanilines with alkenes, alkynes, and diynes in continuous flow

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Science China Chemistry 2016年第2期59卷 180-183页

作者： Jiang Wang Theresa H.Nguyen Nan Zheng Department of Chemistry and Biochemistry University of Arkansas

Continuous flow has recently emerged as a powerful enabling technology that greatly improves many reactions' efficiency. Here, we apply the technology to intermolecular [4+2] annulation of cyclobutylanilines with alkenes, alkynes, and diynes by photoredox catalysis. An across-the-board improvement in the annulation's efficiency is noticed. Moreover, a gram-scale annulation is successfully demonstrated in continuous flow using a much lower catalyst loading.

关键词： photocatalysis continuous flow N-cyclobutylanfline [4+2] annulation visible light

Dental microwear of sympatric rodent species sampled across habitats in southern Africa: Implications for environmental influence

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Integrative Zoology 2016年第2期11卷 111-127页

作者： Jenny H.E.BURGMAN Jennifer LEICHLITER Nico L.AVENANT Peter S.UNGAR Environmental Dynamics Program University of ArkansasFayettevilleArkansasUSA Department of Anthropology University of Colorado BoulderBoulderColoradoUSA National Museum and university of the Free State BloemfonteinSouth Africa Department of Anthropology University of ArkansasFayettevilleArkansasUSA

Dental microwear textures have proven to be a valuable tool for reconstructing the diets of a wide assortment of fossil ***,some studies have recently questioned the efficacy of this approach,suggesting that aspects of habitat unrelated to food preference,especially environmental grit load,might have a confounding effect on microwear patterning that obscures the diet *** we evaluate this hypothesis by examining microwear textures of 3 extant sympatric rodent species that vary in diet breadth and are found in a variety of habitat types:Mastomys coucha,Micaelamys namaquensis and Rhabdomys *** sample each of these species from 3 distinct environmental settings in southern Africa that differ in rainfall and vegetative cover:Nama-Karoo shrublands(semi-desert)and Dry Highveld grasslands in the Free State Province of South Africa,and Afromontane(wet)grasslands in the highlands of *** differences between habitat types are evident for some of the species,inconsistency in the pattern suggests that the microwear signal is driven by variation in foods eaten rather than grit-level per *** is clear that,at least for species and habitats sampled in the current study,environmental grit load does not swamp diet-related microwear signatures.

关键词： diet grit tooth wear

Finding vibrations of inclined cable structures by approximately solving governing equations for exterior matrix

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Applied Mathematics and Mechanics(English Edition) 2015年第11期36卷 1383-1402页

作者： W.PAULSEN M.MANNING Department of Mathematics and Statistics Arkansas State University

In this paper, how to compute the eigenfrequencies of the structures composed of a series of inclined cables is shown. The physics of an inclined cable can be complicated, so solving the differential equations even approximately is difficult. However, rather than solving the system of 4 first-order equations governing the dynamics of each cable, the governing equations are instead converted to a set of equations that the exterior matrix satisfies. Therefore, the exterior matrix method （EMM） is used without solving the original governing equations. Even though this produces a system of 6 first-order equations, the simple asymptotic techniques to find the first three terms of the perturbative solution can be used. The solutions can then be assembled to produce a 6 x 6 exterior matrix for a cable section. The matrices for each cable in the structure are multiplied together, along with the exterior matrices for each joint. The roots of the product give us the eigenfrequencies of the system.

关键词： exterior matrix method (EMM) eigenfrequency inclined cable

Holed Nanostructures Formed by Aluminum Droplets on a GaAs Substrate

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Nano Research 2010年第7期3卷 490-495页

作者： Alvason Zhenhua Li Zhiming M.Wang Jiang Wu Gregory J.Salamo Institute of Nanoscale Science and Engineering University of ArkansasFayettevilleArkansas 72701USA

We have studied the morphology evolution of holed nanostructures formed by aluminum droplet epitaxy on a GaAs *** outer rings with concentric inner holed rings were ***,an empirical equation to describe the size distribution of the outer rings in the holed nanostructures has been *** contour line generated by the equation provides physical insights into quantum ring formation by droplets of groupⅢmaterials onⅢ-Ⅴsubstrates.

关键词： Droplet epitaxy aluminum droplets MBE GaAs holed nanostructures

An examination of thematic research,development,and trends in remote sensing applied to conservation agriculture

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International Soil and Water Conservation Research 2024年第1期12卷 77-95页

作者： Zobaer Ahmed Aaron Shew Lawton Nalley Michael Popp V.Steven Green Kristofor Brye Center for Advanced Spatial Technologies University of ArkansasFayettevilleARUSA Environmental Dynamics Program University of ArkansasFayettevilleARUSA Department of Agricultural Economics and Agribusiness University of ArkansasFayettevilleARUSA College of Agriculture Arkansas State UniversityJonesboroARUSA university of arkansas System Division of Agriculture Little RockARUSA Department of Crop Soiland Environmental SciencesUniversity of ArkansasFayettevilleARUSA

Conservation agriculture seeks to reduce environmental degradation through sustainable management of agricultural *** the 1990s,agricultural research has been conducted using remote sensing technologies;however,few previous reviews have been conducted focused on different conservation management *** of the previous literature has focused on the application of remote sensing in agriculture without focusing exclusively on conservation practices,with some only providing a narrative review,others using biophysical remote sensing for quantitative estimates of the bio-geo-chemical-physical properties of soils and crops,and few others focused on single agricultural management *** paper used the preferred reporting items for systematic review(PRISMA)methodology to examine the last 30 years of thematic research,development,and trends associated with remote sensing technologies and methods applied to conservation agriculture research at various spatial and temporal scales.A set of predefined key concepts and keywords were applied in three databases:Scopus,Web of Science,and Google Scholar.A total of 188 articles were compiled for initial examination,where 68 articles were selected for final analysis and grouped into cover crops,crop residue,crop rotation,mulching,and tillage *** on conservation agriculture research using remote sensing have been increasing since 1991 and peaked at 10 publications in *** the 68 articles,94%used a pixel-based,while only 6%used an object-based classification *** to 2005,tillage practices were abundantly studied,then crop residue was a focused theme between 2004 and *** 2012 to 2020,the focus shifted again to cover *** spectral indices were used in 76%of the 68 *** examination offered a summary of the new potential and identifies crucial future research needs and directions that could improve the contribution of remote sensing to the provision of long-term operat

关键词： Remote sensing Conservation agriculture Classification algorithm Spatial resolution Satellite Spectral indices PRISMA