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Mechanisms of species divergence through visual adaptation and sexual selection:Perspectives from a cichlid model system

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Current Zoology 2010年第3期56卷 285-299页

作者： Martine E.MAAN ole SEEHAUSEN Institute of Ecology & Evolution University of Bern Eawag Centre of Ecology Evolution and Biogeochemistry(CEEB)

The theory of ecological speciation suggests that assortative mating evolves most easily when mating preferences aredirectly linked to ecological traits that are subject to divergent selection. Sensory adaptation can play a major role in this process,because selective mating is often mediated by sexual signals: bright colours, complex song, pheromone blends and so on. Whendivergent sensory adaptation affects the perception of such signals, mating patterns may change as an immediate ***, mating preferences can diverge as a result of indirect effects: assortative mating may be promoted by selectionagainst intermediate phenotypes that are maladapted to their (sensory) environment. For Lake Victoria cichlids, the visual environmentconstitutes an important selective force that is heterogeneous across geographical and water depth gradients. We investigatethe direct and indirect effects of this heterogeneity on the evolution of female preferences for alternative male nuptial colours(red and blue) in the genus Pundamilia. Here, we review the current evidence for divergent sensory drive in this system, extractgeneral principles, and discuss future perspectives [Current Zoology 56 (3): 285-299, 2010].

关键词： Cichlid Sexual selection Species divergence Visual adaptation

Effects of Topography and Land use on Woody Plant Species Composition and Beta Diversity in an Arid Trans-Himalayan Landscape, Nepal

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Journal of Mountain Science 2014年第5期11卷 1112-1122页

作者： Shishir PAUDEL ole R VETAAS Natural Resources Ecology and Management Oklahoma State UniversityStillwater OK 74078 USA Department of Geography University of BergenPost Box 7800 N-5020 Bergen Norway

Distribution patterns of plant species are believed to be impacted by small-scale habitat heterogeneity. However, there have been few comparative studies examining how woody vegetation composition and diversity varies with aspects of different orientations in the Trans-Himalayan region at a local scale. Here, we examined the effects of incoming solar radiation on variation in woody species composition and compared the diversity between the northeast- and southwest-facing slopes in a Trans-Himalayan valley of Nepal. We also examined the implicit interactions between slope orientation and land use in determining the compositional variations between the slopes. We selected two pairs of northeast- and southwest-facing slopes where the first pair has a similar land use and differs in exposure only(Pisang site) while the other pair has clear differences in land use in addition to slope exposure(Braka site). In each site, we sampled 72 plots(36 on each slope) in which the presence and absence of woody species, environmental variables, and disturbance were recorded. Correspondence Analysis(CA) results suggested that the woody species composition significantly varied between northeast- and southwest-facing slopes at both sites, and was significantly correlated with measured environmental variables such as radiation index, altitude, and canopy openness. In the Braka site,mean alpha diversity was significantly higher on southwest-facing slopes. In contrast, beta diversity and gamma diversity were greater on northeast-facing slopes at both sites. Our results suggest that topographic variables(e.g., radiation index) affect species composition between the slopes, likely due to their influence on small scale abiotic environmental variables. However, the effects of land use, such as livestock browsing/grazing may interact with the effects of slope exposure, effectively reducing differences in species composition within slopes but enhancing the differences in beta diversity between

关键词： Correspondence analysis Diversity Environmental gradients Himalaya Land use Topographic aspect Woody vegetation

MicroRNAs in inflammatory bowel disease-pathogenesis,diagnostics and therapeutics

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World Journal of Gastroenterology 2012年第34期18卷 4629-4634页

作者： Mehmet Coskun Jacob Tveiten Bjerrum Jakob Benedict Seidelin ole Haagen nielsen Department of Gastroenterology Medical Section 54 O3University of CopenhagenHerlev HospitalDK-2730 HerlevDenmark Department of Cellular and Molecular Medicine the Panum InstituteUniversity of CopenhagenDK-2200 Copenhagen NDenmark Department of Internal Medicine I University of CopenhagenBispebjerg HospitalDK-2400 Copenhagen NVDenmark

The pathogenesis of inflammatory bowel disease (IBD) is complex and largely unknown. Until recently, research has focused on the study of protein regulators in inflammation to reveal the cellular and molecular networks in the pathogenesis of IBD. However, in the last few years, new and promising insights have been generated from studies describing an association between an altered expression of a specific class of non-coding RNAs, called microRNAs (miRs or miRNAs) and IBD. The short (approximately 22 nucleotides), endogenous, single-stranded RNAs are evolutionary conserved inanimals and plants, and regulate specific target mRNAs at the post-transcriptional level. MiRNAs are involved in several biological processes, including development, cell differentiation, proliferation and apoptosis. Furthermore, it is estimated that miRNAs may be responsible for regulating the expression of nearly one-third of the genes in the human genome. Thus, miRNA deregulation often results in an impaired cellular function, and a disturbance of downstream gene regulation and signaling cascades, suggesting their implication in disease etiology. Despite the identification of more than 1900 mature human miRNAs, very little is known about their biological functions and functional targets. Recent studies have identified dysregulated miRNAs in tissue samples of IBD patients and have demonstrated similar differences in circulating miRNAs in the serum of IBD patients. Thus, there is great promise that miRNAs will aid in the early diagnosis of IBD, and in the development of personalized therapies. Here, we provide a short review of the current state-of-the-art of miRNAs in IBD pathogenesis, diagnostics and therapeutics.

关键词： Biomarker Crohn's disease Diagnostics In-flammatory bowel disease MicroRNA Therapeutics Ulcer-ative colitis

The First-Quantized Theory of Photons

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Chinese Physics Letters 2007年第2期24卷 418-420页

作者：王智勇熊彩东 Keller ole School of Physical Electronics University of Electronic Science and Technology of China Chengdu 610054 Institute of Physics Aalborg Universlty Pontoppldanstrcede 103 DK-9220 Aalborgest Denmark

In near-field optics and optical tunnelling theory, photon wave mechanics, i.e. the first-quantized theory of photons, allows us to address the spatial field localization problem in a flexible manner which links smoothly to classical electromagnetics. We develop photon wave mechanics in a rigorous and unified way, based on which field quantization is obtained in a new way.

关键词： WAVE-FUNCTION LOCALIZATION

Design and development of guide vane cascade for a low speed number Francis turbine

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Journal of Hydrodynamics 2016年第4期28卷 676-689页

作者： Biraj Singh THAPA Chirag TRIVEDI ole Gunnar DAHLHAUG Department of Energy and Process Engineering Norwegian University of Science and Technology

Guide vane cascade of a low speed number Francis turbine is developed for the experimental investigations. The test setup is able to produce similar velocity distributions at the runner inlet as that of a reference prototype turbine. Standard analytical methods are used to design the reference turbine. Periodic walls of flow channel between guide vanes are identified as the starting profile for the boundary of the cascade. Two alternative designs with three guide vanes and two guide vanes, without runner, are studied. A new approach, for the hydraulic design and optimization of the cascade test setup layout, is proposed and investigated in details. CFD based optimization methods are used to define the final layout of the test setup. The optimum design is developed as a test setup and experimental validation is done with PIV methods. The optimized design of cascade with one guide vane between two flow channels is found to produce similar flow conditions to that in the runner inlet of a low speed number Francis turbine.

关键词： guide vanes Francis turbine cascade optimization CFD PIV

Shot-noise limited, supercontinuum-based optical coherence tomography

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Light(Science & Applications) 2021年第7期10卷 1372-1384页

作者： Shreesha Rao D.S. Mikkel Jensen Lars Grüner-nielsen Jesper Toft Olsen Peter Heiduschka Björn Kemper Jürgen Schnekenburger Martin Glud Mette Mogensen Niels Møller Israelsen ole Bang DTU Fotonik Dept.of Photonics EngineeringTechnical University of DenmarkØrsteds Plads2800 Kongens LyngbyDenmark NKT Photonics A/S Blokken 843460 BirkerødDenmark Department of Ophthalmology University of Münster Medical CentreDomagkstr.15D-48149 MünsterGermany Biomedical Technology Center of the Medical Faculty University of MünsterMendelstr.17D-48149 MünsterGermany Department of Dermatology Bisbebjerg HospitalUniversity of CopenhagenBispebjerg Bakke 232400 Copenhagen NVDenmark

We present the first demonstration of shot-noise limited supercontinuum-based spectral domain optical coherence tomography(SD-OCT)with an axial resolution of 5.9μm at a center wavelength of 1370 *** supercontinuumbased SD-OCT systems cannot be operated in the shot-noise limited detection regime because of severe pulse-topulse relative intensity noise of the supercontinuum *** overcome this disadvantage,we have developed a low-noise supercontinuum source based on an all-normal dispersion(ANDi)fiber,pumped by a femtosecond *** noise performance of our 90 MHz ANDi fiber-based supercontinuum source is compared to that of two commercial sources operating at 80 and 320 MHz repetition *** show that the low-noise of the ANDi fiber-based supercontinuum source improves the OCT images significantly in terms of both higher contrast,better sensitivity,and improved *** SD-OCT imaging of skin,retina,and multilayer stacks we conclude that supercontinuumbased SD-OCT can enter the domain of shot-noise limited detection.

关键词： fiber optical pumped

Umamification of food facilitates the green transition

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Soil Ecology Letters 2023年第1期5卷 1-3页

作者： ole G.Mouritsen Department of Food Science Taste forLifeDesign and Consumer BehaviorUniversity of Copenhagen26 RolighedsvejDK-1958 FrederiksbergDenmark

The planet is facing a global climate *** have urgently to be taken to alleviate the consequences by diminishing emission of greenhouse gases,cutting fossil energy consumption,and implementing sustainable uses of the world's *** responsible for more than one third of the stressors on the climate,the global food production systems and our eating behavior must change dramatically(Vermeulen et al.,2012).

关键词： planet consequences gases

Hydraulic energy indices reveal spatial dependence in a subtropical soil under maize crop in Southern Brazil

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Pedosphere 2021年第5期31卷 771-782页

作者： Maria Eliza TUREK Robson Andre ARMINDO ole WENDROTH Graduate Program of Environmental Engineering(PPGEA) Federal University of Paraná(UFPR)Curitiba 81531980(Brazil) Department of Physics(DFI) Federal University of Lavras(UFLA)Mailbox 3037Lavras 37200900(Brazil) Department of Plant&Soil Sciences University of Kentucky(UK)Lexington 40546-0091(USA)

Soil physical quality(SPQ)assessment is an important part in the evaluation of soil use,management,and *** can be assessed using several physical properties,hydraulic indices,and *** from tropical and temperate regions represent different physical behaviors,and the quantification of their physical properties is important to support soil evaluation and *** objective of this study was to evaluate the SPQ in a subtropical field under maize crop cultivation according to its physical properties,hydraulic indices,and functions in an attempt to infer the spatial variability and to determine the behavior of soil physical structure across a spatial *** used soil key physical variables,such as texture,bulk density,total porosity,saturated hydraulic conductivity,and organic carbon content,were measured in a regular grid with a soil sampling density of 30 points per hectare,covering an area of0.5 *** hydraulic conductivity varied strongly between subsamples and in the field,suggesting the heterogeneity of the soil structure regarding water *** physical variables were combined with other indicators,which were based on the soil water retention curve and the pore size distribution(PSD)*** analysis was performed to verify the relationship between the measured and calculated variables,and some strong linear correlations were revealed,such as between aeration energy index and microporosity(r=0.608)and water retention energy index with microporosity(r=0.532)and with bulk density(r=0.541).For most sampled locations,the shape and location parameters of PSD showed results outside of the optimum ranges,whereas the hydraulic energy indices and cumulative hydraulic energy functions presented values that were similar to those found for some tropical soils described in the *** spatial variability of these indices was described using semivariograms and kriged maps,indicating the variability of the SPQ i

关键词： geostatistics integral energy pore size distribution soil physical indicators soil physical quality soil water retention curve

A Hybrid Algorithm of Event-Driven and Time-Driven Methods for Simulations of Granular Flows

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Communications in Computational Physics 2011年第9期10卷 1027-1043页

作者： Jun Huang ole Jørgen Nydal Department of Energy and Process Engineering Norwegian University of Science and TechnologyTrondheimNorway

The classical discrete element approach(DEM)based on Newtonian dynamics can be divided into two major groups,event-driven methods(EDM)and timedriven methods(TDM).Generally speaking,TDM simulations are suited for cases with high volume fractions where there are collisions between multiple *** simulations are suited for cases with low volume fractions from the viewpoint of CPU time.A method combining EDM and TDM called Hybrid Algorithm of event-driven and time-driven methods(HAET)is presented in this *** HAET method employs TDM for the areas with high volume fractions and EDM for the remaining areas with low volume *** can decrease the CPU time for simulating granular flows with strongly non-uniform volume *** addition,a modified EDM algorithm using a constant time as the lower time step limit is ***,an example is presented to demonstrate the hybrid algorithm.

关键词： Time-driven method(TDM) event-driven method(EDM) Hybrid algorithm of eventdriven and time-driven methods(HAET) granular flow