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Spatial distribution of archaeal and bacterial ammonia oxidizers in the littoral buffer zone of a nitrogen-rich lake

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Journal of Environmental Sciences 2012年第5期24卷 790-799页

作者： Huub J. M. Op den camp Department of Microbiology IWWR Radboud University Nijmegen

The spatial distribution and diversity of archaeal and bacterial ammonia oxidizers （AOA and AOB） were evaluated targeting amoA genes in the gradient of a littoral buffer zone which has been identified as a hot spot for N cycling. Here we found high spatial heterogeneity in the nitrification rate and abundance of ammonia oxidizers in the five sampling sites. The bacterial amoA gene was numerically dominant in most of the surface soil but decreased dramatically in deep layers. Higher nitrification potentials were detected in two sites near the land/water interface at 4.4–6.1 μg NO2-N/（g dry weight soil·hr）, while only 1.0–1.7 μg NO2-N/（g dry weight soil·hr） was measured at other sites. The potential nitrification rates were proportional to the amoA gene abundance for AOB, but with no significant correlation with AOA. The NH4＋ concentration was the most determinative parameter for the abundance of AOB and potential nitrification rates in this study. Higher richness in the surface layer was found in the analysis of biodiversity. Phylogenetic analysis revealed that most of the bacterial amoA sequences in surface soil were affiliated with the genus of Nitrosopira while the archaeal sequences were almost equally affiliated with Candidatus ‘Nitrososphaera gargensis’ and Candidatus ‘Nitrosocaldus yellowstonii’. The spatial distribution of AOA and AOB indicated that bacteria may play a more important role in nitrification in the littoral buffer zone of a N-rich lake.

关键词： littoral zone ammonia oxidation archaea bacteria heterogeneity abundance

Novel decoupled framework for reliability-based design optimization of structures using a robust shifting technique

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Frontiers of Structural and Civil Engineering 2019年第4期13卷 800-820页

作者： Mohammad Reza GHASEMI Charles V. camp Babak DIZANGIAN Department of Civil Engineering University of Sistan and Baluchestan Zahedan *** Iran Department of Civil Engineering The University of Memphis Memphis TN 38152 USA Department of Civil Engineering Velayat University Iranshahr *** Iran

In a reliability-based design optimization (RBDO), computation of the failure probability (Pf) at all design points through the process may suitably be avoided at the early stages. Thus, to reduce extensive computations of RBDO, one could decouple the optimization and reliability analysis. The present work proposes a new methodology for such a decoupled approach that separates optimization and reliability analysis into two procedures which significantly improve the computational efficiency of the RBDO. This technique is based on the probabilistic sensitivity approach (PSA) on the shifted probability density function. Stochastic variables are separated into two groups of desired and non-desired variables. The three-phase procedure may be summarized as: Phase 1, apply deterministic design optimization based on mean values of random variables;Phase 2, move designs toward a reliable space using PSA and finding a primary reliable optimum point;Phase 3, applying an intelligent self-adaptive procedure based on cubic B-spline interpolation functions until the targeted failure probability is reached. An improved response surface method is used for computation of failure probability. The proposed RBDO approach could significantly reduce the number of analyses required to less than 10% of conventional methods. The computational efficacy of this approach is demonstrated by solving four benchmark truss design problems published in the structural optimization literature.

关键词： reliability-based design optimization trusses sensitivity analysis shifting technique cubic B-splines response surface method

Response of ants to grazing disturbance at the central Monte Desert of Argentina: community descriptors and functional group scheme

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Journal of Arid Land 2014年第1期6卷 117-127页

作者： Silvia CLAVER Susana L SILNIK Florencia F campóN Entomology Lab IADIZA-CONICET

Livestock ranching is one of the main productive activities in arid regions of the *** produces changes in animal as well as plant communities(***,abundance and species dominance relationships).Ants are good biological indicators due to the environmental fidelity of some of their community *** described the functional structure of the ant community in the central Monte of Mendoza,Argentina,and examined the effect of grazing using richness,diversity and the functional group *** used pitfall traps to sample ants at a reserve with 30-year cattle exclusion and at an adjacent *** of the 27 recorded species showed significant differences in their abundance and two species were absent at the *** richness and diversity did not reflect these differences,functional groups *** Climate Specialists were more abundant at the ranch while Cryptic Species and Generalized Myrmicinae increased at the *** study supports the utility of the functional group scheme to study the effects of grazing disturbance in ant communities of arid regions.

关键词： ants cattle grazing functional groups richness diversity arid zones Monte Desert

Surface Nanopatterning Using the Self-Assembly of Linear Polymers on Surfaces after Solvent Evaporation

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Nanomanufacturing and Metrology 2022年第3期5卷 297-309页

作者： Emmanouil Glynos Alexandros Chremos Philip J.camp Vasileios Koutsos School of Engineering Institute for Materials and ProcessesTheUniversity of EdinburghRobert Stevenson RoadEdinburgh EH93FBUK School of Chemistry The University of EdinburghDavid Brewster RoadEdinburgh EH93FJUK Department of Materials Science and Technology University of Crete71003 HeraklionGreece Section on Quanitative Imaging and Tissue Sciences Eunice Kennedy Shriver National Institute of Child Health and Human DevelopmentNational Institutes of HealthBethesdaMD 20892USA

The morphology of linear polybutadiene physisorbed on freshly cleaved mica from a dilute polymer solution is investigated through atomic force microscopy.A fine-structure study shows that the monolayer morphology in air(after rapid solvent evaporation)depends strongly on the molecular weight(Mw)of the linear polymer,the adsorbed amount,and the conformation adopted by the adsorbed polymer chains under good solvent *** dependence of the observed polymer structure on Mw is most significant for samples with high surface density,where the intermolecular interactions among the adsorbed polymers are *** high surface density,the adsorbed polymers tend to aggregate and minimize unfavorable contacts with air for all of the different Mw samples,leading to an isotropic structural *** structural phenomena with increasing surface density are explained on the basis of the intermolecular interactions of the adsorbed polymers under good solvent conditions,and after the abrupt solvent evaporation corresponding to poor solvent *** experimental observations are further discussed using the results obtained from molecular dynamics simulations of a simple coarse-grained model.

关键词： Surface nanopatterning Self-assembly Nanomanufacturing

Seasonal influence and local factors affecting macroinvertebrate structure in a high-altitude Andean stream

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Journal of Mountain Science 2020年第6期17卷 1374-1386页

作者： SCHEIBLER Erica E FERNáNDEZ campóN Florencia LAGOS SILNIK Susana WELLNITZ Todd Laboratorio de Entomologia IADIZACCT CONICET MendozaAvenida Ruiz Leal s/nParque Gral.San MartinCC 5075500MendozaArgentina Consejo Nacional de Investigaciones Cientificas y Tecnicas(CONICET) Avenida Rivadavia 1917C1033AAJCABAArgentina Facultad de Ciencias Exactas y Naturales Universidad Nacional de CuyoPadre Jorge Contreras 1300M5502JMA MendozaArgentina Biology Department University o f Wisconsin-Eau Claire105 Garfield Avenue54701Eau ClaireWisconsinUSA

Small water bodies are critical for maintaining freshwater biodiversity,but are among the least investigated aquatic *** examined physical and chemical variables at two reaches in Arroyo Tambillos,a small,high-elevation Andean stream,in NW Mendoza province,Argentina,across four seasons to examine how local factors and seasonality affected the structure of the macroinvertebrate *** Arroyo Tambillos community was numerically dominated by ephemeropterans(mainly Massartellopsis irarrazavali)while the dipteran Chironomidae were the most species *** macroinvertebrate abundance was highest in summer,driven mainly by taxa that were secondary in dominance(Austrelmis *** Andesiops peruvianus),while richness did not differ between ***,benthic composition was different in Fall 2013(March)compared to other seasons,largely because of the increased abundance of *** correspondence analysis discriminated Chironomidae species distributions in Fall 2013 by substrate type(i.e.,big and small boulder substrate).By contrast,discharge,velocity,and depth were the variables which most affected the macroinvertebrate abundance and *** to our expectations,most community changes observed occurred in fall instead of ***-kryal stream communities like the one described here have become increasingly important for conserving mountain stream biodiversity as anthropogentic impacts and climate change increasingly impact lower stream ***,monitoring high-altitude streams like the Arroyo Tambillos may be critical for preventing the future loss of unique and sensitive stream biota.

关键词： Ephemeroptera dominance Chironomidae richness Mountain small stream Physical variables Biodiversity Ecosystem

CTGF, intestinal stellate cells and carcinoid fi brogenesis

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World Journal of Gastroenterology 2007年第39期13卷 5208-5216页

作者： M Kidd IM Modlin MD Shapiro RL camp SM Mane W Usinger JR Murren Departments of Surgery Yale University School of Medicine New Haven Connecticut 06520-8062 United States Departments of Pathology Yale University School of Medicine New Haven Connecticut 06520-8062 United States Departments of Affymetrix Resource Keck Biotechnology Resource Laboratory Yale University School of Medicine New Haven Connecticut 06520-8062 United States Fibrogen Inc San Francisco CA United States Departments of Medical Oncology Yale University School of Medicine New Haven Connecticut 06520-8062 United States

AIM： To investigate the role of small intestinal carcinoid tumor-derived fibrotic mediators, TGFβ1 and CTGF, in the mediation of fibrosis via activation of an ＂intestinal＂ stellate cell. METHODS： GI carcinoid tumors were collected for Q RT-PCR analysis of CTGF and TGFβ1. Markers of stellate cell desmoplasia were identified in peritoneal fibrosis by immunohistochemistry and stellate cells cultured from fresh resected fibrotic tissue. CTGF and TGFβ1 were evaluated using quantitative tissue array profiling （AQUA analysis） in a GI carcinoid tissue microarray （TMA） with immunostaining and correlated with clinical and histologically documented fibrosis. Serum CTGF was analyzed using a sandwich ELISA assay. RESULTS： Message levels of both CTGF and TGFβ1 in SI carcinoid tumors were significantly increased （〉 2-fold, P 〈 0.05） versus normal mucosa and gastric （non-fibrotic） carcinoids. Activated stellate cells and markers of stellate cell-mediated fibrosis （vimentin, desmin） were identified in histological fibrosis. An intestinal stellate cell was immunocytochemically and biochemically characterized and its TGFβ1 （10-7M） initiated CTGF transcription response （〉 3-fold, P 〈 0.05） demonstrated. In SI carcinoid tumor patients with documented fibrosis, TMA analysis demonstrated higher CTGF immunostaining （AQUA Score： 92 ± 8, P 〈0.05）, as well as elevated TGFβ1 （90.6 ± 4.4, P 〈 0.05）. Plasma CTGF （normal 12.5 ± 2.6 ng/mL） was increased in SI carcinoid tumor patients （31 ± 10 ng/mL, P 〈 0.05） compared to non-fibrotic GI carcinoids （〈 15 ng/mL） CONCLUSION： SI carcinoid tumor fibrosis is a CTGF/ TGFβl-mediated stellate cell-driven fibrotic response. The delineation of the biology of fibrosis will facilitate diagnosis and enable development of agents to obviate its local and systemic complications.

关键词： Carcinoid Connective tissue growth factor fibrosis Small intestine Stellate cell TGFI

Rhizobium Lipo-chitooligosaccharide Signaling Triggers Accumulation of Cytokinins in Medicago truncatula Roots

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Molecular Plant 2015年第8期8卷 1213-1226页

作者： Arjan van Zeijl Rik H.M. Op den camp Eva E. Deinum Tatsiana Charnikhova Henk Franssen Huub J.M. Op den camp Harro Bouwmeester Wouter Kohlen Ton Bisseling Rene Geurts Department of Plant Sciences Laboratory of Molecular Biology Wageningen University Droevendaalsesteeg 16708 PB Wageningen The Netherlands Department of Systems Biophysics FOM institute AMOLF Science Park 104 1098 XG Amsterdam The Netherlands Department of Plant Sciences Laboratory of Plant Physiology Wageningen University Droevendaalsesteeg 1 6708 PB Wageningen The Netherlands Department of Microbiology IWWR Radboud University Nijmegen Heyendaalseweg 135 6525 AJ Nijmegen The Netherlands College of Science King Saud University Post Office Box 2455 Riyadh 11451 Saudi Arabia

Legume rhizobium symbiosis is initiated upon perception of bacterial secreted lipo-chitooligosaccharides （LCOs）. Perception of these signals by the plant initiates a signaling cascade that leads to nodule formation. Several studies have implicated a function for cytokinin in this process. However, whether cytokinin accu- mulation and subsequent signaling are an integral part of rhizobium LCO signaling remains elusive. Here, we show that cytokinin signaling is required for the majority of transcriptional changes induced by rhizo- bium LCOs. In addition, we demonstrate that several cytokinins accumulate in the root susceptible zone 3 h after rhizobium LCO application, including the biologically most active cytokinins, trans-zeatin and iso- pentenyl adenine. These responses are dependent on calcium- and calmodulin-dependent protein kinase （CCaMK）, a key protein in rhizobial LCO-induced signaling. Analysis of the ethylene-insensitive Mtein21 Mtsickle mutant showed that LCO-induced cytokinin accumulation is negatively regulated by ethylene. Together with transcriptional induction of ethylene biosynthesis genes, it suggests a feedback loop negatively regulating LCO signaling and subsequent cytokinin accumulation. We argue that cytokinin accumulation is a key step in the pathway leading to nodule organogenesis and that this is tightly controlled by feedback loops.

关键词： Medicago truncatula cytokinin ethylene rhizobium lipo-chitooligosaccharides CRE1

Influence of climate fluctuations on Pinus palustris growth and drought resilience

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Forest Ecosystems 2023年第6期10卷 681-689页

作者： Joao campoa Joshua Puhlick CENSE–Center for Environmental and Sustainability Research CHANGE-Global Change and Sustainability InstituteDepartment of Environmental Sciences and EngineeringNOVA School of Science and TechnologyNOVA University LisbonCampus de Caparica2829-516 CaparicaPortugal The Jones Center at Ichauway 3988 Jones Center Drive39870NewtonGAUSA

The longleaf pine(Pinus palustris Mill.)ecosystem is an endangered ecosystem in the southeastern USA,and efforts to restore the species are ***,in recent decades,the region has experienced drastic fluctuations between wet and dry growing season conditions from year to year,and it is not fully understood how these fluctuations have influenced the growth of *** address this topic,we cored *** trees in woodlands of southwest Georgia and used dendrochronology techniques to determine how climate fluctuations have influenced the growth and drought resilience of *** also cored slash pine(Pinus elliottii Engelm.)trees in the same woodlands to compare growth between *** *** growth was less impacted by adverse climate conditions compared to ***,the strength of correlations between *** growth and temperature,precipitation,and Palmer Drought Severity Index(PDSI)changed over *** recent decades,climate conditions during the growing season became more influential on *** growth than the previous year's *** is concerning given that drought severity during the growing season has been *** results also indicate that *** was less resilient to droughts during the 2000s and 2010s than to those of the *** this new climate paradigm,our results suggest that *** might be more susceptible to growth reductions and less resistant to droughts than once *** work highlights the importance of understanding the impact of novel climate conditions on *** and has implications for restoration efforts,such as using silvicultural treatments that reduce tree vulnerability to drought(e.g.,thinning)and promote other climate-adapted species in mixture with ***.

关键词： Longleaf pine Slash pine Pinus elliottii Climate change Dendrochronology Dendroclimatology Forest disturbances

Modelling the potential consequences of adaptive closure management in a penaeid trawl fishery

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Aquaculture and Fisheries 2023年第2期8卷 190-201页

作者： Edward V.camp Daniel D.Johnson Matthew D.Taylor Fisheries and Aquatic Sciences School of ForestFisheriesand Geomatics SciencesUniversity of FloridaGainesville32611FLUSA Port Stephens Fisheries Institute New South Wales Department of Primary IndustriesTaylors Beach RdTaylors BeachNew South Wales2315Australia School of Environmental and Life Sciences University of NewcastleNew South Wales2308Australia

Spatial management of fishing effort can be used to avoid catching undesirable size classes for target species,and improve yield-per-recruit for the exploited *** closure management has been proposed as a means to more effectively utilise spatial management,however these management provisions often lack quantitative evaluation which constrains the information available to inform *** demonstrate the use of a spatially and size structured population dynamics model to evaluate the potential impact of spatial management on a multijurisdictional fishery for a highly migratory species(eastern king prawn,Penaeus[Melicertus]plebejus).Under current conditions in the fishery,the overall effect of closures on harvest was estimated to be comparatively minor,regardless of assumptions about how effort or fisher behavior are affected by spatial *** assumptions about the movement patterns of eastern king prawn had little influence on the impact of closures on overall ***,when effort was increased to historic levels similar to those observed when the closures were implemented,a much greater impact on overall harvest was *** approach taken and simulation outcomes are discussed in the context of spatial management for both eastern king prawn,and penaeid fisheries more broadly.

关键词： Penaeidae Trawl Management strategy evaluation Closures Adaptive management