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Comparison of aerosol optical depth of UV-B Monitoring and Research Program （UVMRP）, AERONET and MODIS over continental United states

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Frontiers of Earth Science 2013年第2期7卷 129-140页

作者： Hongzhao TANG Maosi CHEN John DAVIS Wei GAO USDA UV-B Monitoring and Research Program Natural Resource Ecology Laboratory Colorado State University Fort Collins CO 80521 USA Department of Ecosystem Science and Sustainability Colorado State University Fort Collins C-O 80521 USA

The concern about the role of aerosols as to their effect in the Earth-Atmosphere system requires observation at multiple temporal and spatial scales. The Moderate Resolution Imaging Spectroradiameters （MODIS） is the main aerosol optical depth （AOD） monitoring satellite instrument, and its accuracy and uncertainty need to be validated against ground based measurements routinely. The comparison between two ground AOD measurement programs, the United states Department of Agriculture （USDA） Ultmviolet-B Monitoring and Research Program （UVMRP） and the Aerosol Robotic Network （AERONET） program, confirms the consistency between them. The intercomparison between the MODIS AOD, the AERONET AOD, and the UVMRP AOD suggests that the UVMRP AOD measurements are suited to be an alternative ground-based validation source for satellite AOD products. The experiments show that the spatial-temporal dependency between the MODIS AOD and the UVMRP AOD is positive in the sense that the MODIS AOD compare more favorably with the UVMRP AOD as the spatial and temporal intervals are increased. However, the analysis shows that the optimal spatial interval for all time windows is defined by an angular subtense of around 1° to 1.25°, while the optimal time window is around 423 to 483 minutes at most spatial intervals. The spatial-temporal approach around 1.25° ＆ 423 minutes shows better agreement than the prevalent strategy of 0.25° ＆ 60 minutes found in other similar investigations.

关键词： aerosol optical depth (AOD) United states Department of Agriculture (USDA) UV-B Monitoring andResearch Program (UVMRP) Aerosol Robotic Network (AERONET) Moderate Resolution Imaging Spectmradiameters (MODIS) validation spatial-temporal approach

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Moisture and temperature controls on nitrification differ among ammonia oxidizer communities from three alpine soil habitats

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Frontiers of Earth Science 2016年第1期10卷 1-12页

作者： Brooke B. OSBORNE Jill S. BARON Matthew D. WALLENSTEIN Natural Resource Ecology Laboratory Colorado State University Fort Collins CO 80523 USA Present address: Department of Ecology and Evolutionary Biology Brown University Providence RI 02912 USA U.S. Geological Survey fort collins Science Center Fort Collins CO 80526 USA Department of Ecosystem Science and Sustainability Colorado State University Fort Collins CO 80523 USA

Climate change is altering the timing and magnitude of biogeochemical fluxes in many high- elevation ecosystems. The consequent changes in alpine nitrification rates have the potential to influence ecosystem scale responses. In order to better understand how changing temperature and moisture conditions may influence ammonia oxidizers and nitrification activity, we conducted laboratory incubations on soils collected in a colorado watershed from three alpine habitats （glacial outwash, talus, and meadow）. We found that bacteria, not archaea, dominated all ammonia oxidizer communities. Nitrification increased with moisture in all soils and under all temperature treatments. However, temperature was not correlated with nitrification rates in all soils. Site-specific temperature trends suggest the development of generalist ammonia oxidzer communities in soils with greater in situ temperature fluctuations and specialists in soils with more steady temperature regimes. Rapidly increasing tempera- tures and changing soil moisture conditions could explain recent observations of increased nitrate production in some alpine soils.

关键词： ammonia-oxidizing archaea (AOA) ammo-nia-oxidizing bacteria (AOB) global change Loch Valewatershed nitrification thermal adaptation

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Numerical Analysis of PRISM-PY Calculations for Hard-and Soft-Core Generic Polymer Models

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Chinese Journal of Polymer Science 2024年第4期42卷 532-543页

作者： Qiang Wang Department of Chemical and Biological Engineering Colorado State University1370 Campus DeliveryFort CollinsCO80523-1370USA

Generic polymer models capturing the chain connectivity and excluded-volume interactions between polymer segments can be classified, according to whether or not the 3D integral of the latter diverges, into hard- and soft-core models. Taking homogeneous systems of compressible homopolymer melts (or equivalently homopolymer solutions in an implicit, good solvent) in the continuum as an example, we recently compared the correlation effects on the structural and thermodynamic properties of the hard- and soft-core models given by the polymer reference interaction site model (PRISM) theory with the Percus-Yevick (PY) closure (Polymers 2023, 15, 1180). Here we analyzed in detail the numerical errors and behavior of the interchain pair correlation functions (PCFs) given by the PRISM-PY calculations of these models using an efficient numerical approach that we proposed. Our numerical approach has the least number of independent variables to be iteratively solved, analytically treats the discontinuities caused by the non-bonded pair potential (such as that of the hard spheres) and takes only the inverse Fourier transform of the interchain indirect PCF between polymer segments (which is continuous and decays towards 0 with increasing wavenumber much faster than both the interchain direct and total PCFs), and is essential for us to accurately solve the PRISM-PY theory for chain length N as large as 106. To capture the correlation-hole effect, the real-space cut-off in the PRISM calculations should be proportional to the square root of N.

关键词： Generic polymer models Soft potentials Polymer reference interaction site model theory

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Identifying and mitigating dam-induced declines in river health:Three case studies from the western United states

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International Journal of Sediment Research 2012年第3期27卷 271-287页

作者： Ellen WOHL Department of Geosciences Colorado State UniversityFort CollinsColorado 80523-1482 USA Prof.Dr.

River health can be defined as the degree to which riverine energy source,water quality,flow regime, habitat and biota match the natural *** a healthy river,physical process and form remain actively connected and able to mutually adjust,and biological communities have natural levels of diversity and are resilient to environmental *** physical diversity and biodiversity influence river *** diversity is governed by hydrology,hydraulics,and substrate,as reflected in the geometry of the river channel and adjacent floodplain,which create habitat for aquatic and riparian *** is governed by biological processes such as competition and predation,but biodiversity also reflects the diversity,abundance and stability of habitat,as well as connectivity. Connectivity within a river corridor includes longitudinal,lateral,and vertical *** health declines as any of these interacting components is compromised by human *** cumulative effect of dams and other human alterations of rivers has been primarily to directly reduce physical diversity and connectivity,which indirectly reduces *** and maintenance of physical diversity and biodiversity on rivers affected by dams requires quantifying relations between the driver variables of flow and sediment supply,and the response variables of habitat,connectivity,and biological *** relations can take the form of thresholds(e.g., entrainment of streambed sediment) or response curves(e.g.,fish biomass versus extent and duration of floodplain inundation).I use examples from Wyoming,colorado,and Arizona in the western United states to illustrate how to quantify relations between driver and response variables on rivers affected by dams.

关键词： River health Dams River restoration

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Global consistency check of AIRS and IASI total CO2 column concentrations using WDCGG ground-based measurements

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Frontiers of Earth Science 2017年第1期11卷 1-10页

作者： Anyuan DIAO Jiong SHU Ci SONG Wei GAO Key Laboratory of Geographic Information Science (Ministry of Education) School of Geographic Sciences East China Normal University Shanghai 200241 China colorado state university Department of Ecosystem Science and Sustainability Fort Collins Colorado 80523 USA colorado state university Natural Resource Ecology Laboratory Fort Collins Colorado 80523 USA

This article describes a global consistency check of CO2 satellite retrieval products from the Atmospheric Infrared Sounder （AIRS） and Infrared Atmospheric Sounding Interferometer （IASI） using statistical analysis and data from the World Data Centre for Greenhouse Gases （WDCGG）. We use the correlation coefficient （r）, relative difference （RD）, root mean square errors （RMSE）, and mean bias error （MBE） as evaluation indicators for this study. Statistical results show that a linear positive correlation between AIRS/IASI and WDCGG data occurs for most regions around the world. Temporal and spatial variations of these statistical quantities reflect obvious differences between satellite-derived and ground-based data based on geographic position, especially for stations near areas of intense human activities in the Northern Hemisphere. It is noteworthy that there appears to be a very weak correlation between AIRS/IASI data and ten ground- based observation stations in Europe, Asia, and North America. These results indicate that retrieval products from the two satellite-based instruments studied should be used with great caution.

关键词： CO2 consistency check AIRS IASI WDCGG

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Diurnal feeding as a potential mechanism of osmoregulation in aphids

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Insect Science 2021年第2期28卷 521-532页

作者： Vamsi Nalam Travis Isaacs Sarah Moh Jessica Kansman Deborah Finke Tessa Albrecht Punya Nachappa Department of Agricultural Biology Colorado State UniversityFort CollinsColoradoUSA Department of Biology Purdue University Fort WayneFort WayneIndianaUSA Division of Plant Sciences University of MissouriColumbiaMissouriUSA

Diurnal variation in phloem sap composition has a strong infuence on aphid *** sugar-rich phloem sap serves as the sole diet for aphids and a suite of physiological mechanisms and behaviors allowv them to tolerate the high osmotic ***,we tested the hypothesis that night-time feeding by aphids is a behavior that takes advantage of the low sugar diet in the night to compensate for osmotic stress incurred while feeding on high sugar diet during the *** the electrical penetration graph(EPG)*** examined the eiects of diurmal rhythm on feeding behaviors of bird cherry-oat aphid(Rhopalosiphurm padi L.)on wheat.A strong diurmal rhythm in aphids as indicated by the presence of a cyclical pattern of expression in a core clock gene did not impact aphid feeding and similar feeding behaviors were observed during day and *** major difference observed between day and night feeding was that aphids spent significantly longer time in phloem salivation during the night compared to the *** contrast,aphid hydration was reduced at the end of the day-time feeding compared to end of the night-time *** expression analysis of *** osmoregulatory genes indicated that sugar break down and water transport into the aphid gut was reduced at *** data suggest that while diumal variation occurs in phloem sap composition,aphids use night time feeding to overcome the high osmotic stress incurred while feeding on sugar-rich phloem sap during the day.

关键词： bird cherry-oat aphid diurnal cycle electrical penetration graph hydraion osmoregulation phloem

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Evaluation of ambient mass spectrometry tools for assessing inherent postharvest pepper quality

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Horticulture Research 2021年第1期8卷 2252-2259页

作者： Tyler J.Mason Harmonie M.Bettenhausen Jacqueline M.Chaparro Mark E.Uchanski Jessica E.Prenni Department of Horticulture and Landscape Architecture Colorado State UniversityFort CollinsCO 80524USA

Horticulturists are interested in evaluating how cultivar,environment,or production system inputs can affect postharvest *** mass spectrometry approaches enable analysis of minimally processed samples under ambient conditions and offer an attractive high-throughput alternative for assessing quality characteristics in plant ***,we evaluate direct analysis in real time(DART-MS)mass spectrometry and rapid evaporative ionization-mass spectrometry(REIMS)to assess quality characteristics in various pepper(Capsicum annuum L.)***-MS exhibited the ability to discriminate between pod colors and pungency based on chemical fingerprints,while REIMS could distinguish pepper market class(e.g.,bell,lunchbox,and popper).Furthermore,DART-MS analysis resulted in the putative detection of important bioactive compounds in human diet such as vitamin C,p-coumaric acid,and *** results of this study demonstrate the potential for these approaches as accessible and reliable tools for high throughput screening of pepper quality.

关键词： cultivar pepper ambient

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Effects of mountain pine beetle-killed forests on source water contributions to streamflow in headwater streams of the colorado Rocky Mountains

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Frontiers of Earth Science 2017年第3期11卷 496-504页

作者： Christine E. WEHNER John D. STEDNICK Watershed Science Program College of Natural Resources Colorado State University Fort Collins CO 80523-1472 USA

Natural or human-influenced disturbances are important to the health and diversity of forests, which in turn, are important to the water quantity and quality exported from a catchment. However, human-induced disturbances （prescribed fire and harvesting） have been decreasing, and natural disturbances （fires and insects） have been increasing in frequency and severity. One such natural disturbance is the mountain pine beetle （MPB）, （Denclroctonus ponderosae） an endemic species. A recent epidemic resulted in the mortality of millions of hectares of lodgepole pine （Pinus contorta） forests in colorado, USA. Beetle-induced tree mortality brings about changes to the hydrologic cycle, including decreased transpiration and interception with the loss of canopy cover. This study examined the effect of the mountain pine beetle kill on source water contributions to streamflow in snowmelt- dominated headwater catchments using stable isotopes （2H and ~80） as tracers. Study catchments with varying level of beetle-killed forest area （6% to 97%） were sampled for groundwater, surface water, and precipitation. Streams were sampled to assess whether beetle-killed forests have altered source water contributions to streamflow. Ground- water contributions increased with increasing beetle-killed forest area （p = 0.008）. Both rain and snow contributions were negatively correlated with beetle-killed forest area （p = 0.035 and p = 0.011, respectively）. As the beetle-killed forest area increases, so does fractional groundwater contribution to streamflow.

关键词： mountain pine beetle isotope tracers stream-flow generation headwaters

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High-throughput molecular gut content analysis of aphids identifies plants relevant for potato virus Y epidemioiogy

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Insect Science 2024年第5期31卷 1489-1502页

作者： William Jacob Pitt William Rodney Cooper Derek Pouchnik Heather Headrick Punya Nachappa Department of Agricultural Biology Colorado State UniversityFort CollinsColoradoUSA Graduate Degree Program in Ecology Colorado State UniversityFort CollinsColoradoUSA USDA-ARS Temperate Tree Fruit and Vegetable Research Unit WapatoWashingtonUSA Laboratory for Biotechnology and BioanalysisWashington state university PullmanWashingtonUSA Tree Fruit Research and Extension Center Washington State UniversityWenatcheeWashingtonUSA

Aphids are phloem-feeding insects that reduce crop productivity due to feeding and transmission of plant *** aphids disperse across the landscape to colonize new host plants,they will often probe on a wide variety of nonhost plants before settling on a host suitable for feeding and *** is limited understanding of the diversity of plants that aphids probe on within a landscape,and characterizing this diversity can help us better understand host use patterns of ***,we used gut content analysis(GCA)to identify plant genera that were probed by aphid vectors of potato virus Y(PVY).Aphids were trapped weekly near potato fields during the growing seasons of 2020 and 2021 in San Luis Valley in ***-throughput sequencing of plant barcoding genes,trnF and ITS2,from 200 individual alate(i.e.,winged)aphids representing nine vector species of PVY was performed using the PacBio sequencing platform,and sequences were identi-fied to genus using NCBI *** found that 34.7%of aphids probed upon presumed PVY host plants and that two of the most frequently detected plant genera,Solanum and Brassica,represent important crops and weeds within the study *** found that 75%of aphids frequently probed upon PVY nonhosts including many species that are outside of their reported host ***,19%of aphids probed upon more than one plant *** study provides the first evidence from high-throughput molecular GCA of aphids and reveals host use patterns that are relevant for PVY epidemiology.

关键词： aphids epidemiology gut content analysis insect ecology plant-insect in-teractions plant disease

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Stable reinforcement learning with recurrent neural networks

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控制理论与应用（英文版） 2011年第3期9卷 410-420页

作者： James Nate KNIGHT Charles ANDERSON Department of Computer Science Colorado State UniversityFort CollinsCO 80523U.S.A

In this paper,we present a technique for ensuring the stability of a large class of adaptively controlled *** combine IQC models of both the controlled system and the controller with a method of filtering control parameter updates to ensure stable behavior of the controlled system under adaptation of the *** present a specific application to a system that uses recurrent neural networks adapted via reinforcement learning *** work presented extends earlier works on stable reinforcement learning with neural ***,we apply an improved IQC analysis for RNNs with time-varying weights and evaluate the approach on more complex control system.

关键词： Stability analysis Integral quadratic constraint Recurrent neural network Reinforcement learning Linear matrix inequality

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