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Exploring the size of Andean condor foraging groups along an altitudinal and latitudinal gradient in the Tropical Andes: Ecological and conservation implications

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current Zoology 2024年第2期70卷 225-232页

作者： Diego Mendez Felix Hernan Vargas JoséHernan Sarasola Pedro P.Oleaa Departamento de Ecologia Universidad Autonoma de MadridCalle Darwin 228049MadridSpain Museo Nacional de Historia Natural Calle 26 s/nCota CotaLa PazBolivia The Peregrine Fund 5668 West Flying Hawk LaneBoiseID 83709USA Centro para el Estudio y Conservacion de Aves Rapaces en Argentina(CECARA) Universidad Nacional de La PampaAvda Uruguay 1516300 Santa RosaLa PampaArgentina Instituto de las Ciencias Ambientales y de la Tierra de La Pampa(INCITAP-CONICET) Avda.Uruguay 1516300 Santa RosaLa PampaArgentina Centro de Investigacion en Biodiversidad y Cambio Global(CIBC-UAM) Universidad Autonoma de MadridMadridCalle Darwin 228049Madrid Snain

Patterns of variation in the size of vulture foraging groups,and their ecological causes and consequences,remain litle explored despite strong links with the carrion recycling service that this key functional group *** documented the group size-frequency pattern of Andean con-dors Vultur gryphus gathered to feed on 42 equine carcasses experimentally placed in Bolivia,between 2012 and 2019,along an elevation range of 1,300-4,500 m *** on the location(altitude and latitude)of the foraging groups,we examined the relationship between their size and species'population parameters(size and trend),habitat conditions,and livestock carcass availability and *** utilized a high frequency(93%)of carcasses forming groups that ranged from 1 to 80 individuals(mean=25,median=18)and shaped a"lazy-J curve"typical pattern of size-frequency distribution whereby few groups(5,12%)were large(>55 individuals)and most(21,50%)were relatively small(address them,especially amidst the unrestricted impacts of human activities that condition vulture survival globally.

关键词： condor andino fusion-fission dynamics group size scavenger social foraging vultures.

Characterization of the Formation of Branched Short-Chain Fatty Acid：CoAs for Bitter Acid Biosynthesis in Hop Glandular Trichomes

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Molecular Plant 2013年第4期6卷 1301-1317页

作者： Haiyang Xu Fengxia Zhang Baoxiu Liu David V. Huhman Lloyd W. Sumner Richard A. Dixon Guodong Wang State Key Laboratory of Plant Genomics and National Center for Plant Gene Research Institute of Genetics and Developmental Biology Chinese Academy of Sciences Beijing 100101 China University of Chinese Academy of Sciences Beijing 100039 China The Samuel Roberts Noble Foundation Plant Biology 2510 Sam Noble Parkway Ardmore OK 73401 USA current address: Department of Biological Sciences University of North Texas Denton Texas 76203 USA

Bitter acids, known for their use as beer flavoring and for their diverse biological activities, are predominantly formed in hop （Humulus lupulus） glandular trichomes. Branched short-chain acyI-CoAs （e.g. isobutyryI-CoA, isovaleryl- CoA and 2-methylbutyryI-CoA）, derived from the degradation of branched-chain amino acids （BCAAs）, are essential building blocks for the biosynthesis of bitter acids in hops. However, little is known regarding what components are needed to produce and maintain the pool of branched short-chain acyI-CoAs in hop trichomes. Here, we present several lines of evidence that both CoA ligases and thioesterases are likely involved in bitter acid biosynthesis. Recombinant HICCL2 （carboxyl CoA ligase） protein had high specific activity for isovaleric acid as a substrate （Kcat/Km = 4100 s-~ M-l）, whereas recombinant HICCL4 specifically utilized isobutyric acid （Kcat/Km = 1800 s-1 M-1） and 2-methylbutyric acid （Kcat/ Km = 6900 s-1 M-~） as substrates. Both HICCLs, like hop valerophenone synthase （HIVPS）, were expressed strongly in glandular trichomes and localized to the cytoplasm. Co-expression of HICCL2 and HICCL4 with HIVPS in yeast led to significant production of acylphloroglucinols （the direct precursors for bitter acid biosynthesis）, which further confirmed the biochemical function of these two HICCLs in vivo. Functional identification of a thioesterase that catalyzed the reverse reaction of CCLs in mitochondria, together with the comprehensive analysis of genes involved BCAA catabolism, supported the idea that cytosolic CoA ligases are required for linking BCAA degradation and bitter acid biosynthesis in glandular trichomes. The evolution and other possible physiological roles of branched short-chain fatty acid：CoA ligases in planta are also discussed.

关键词： CoA ligase glandular trichomes bitter acid thioesterase evolution Humulus lupulus

The DNA-binding factor Ctcf critically controls gene expression in macrophages

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Cellular & Molecular Immunology 2014年第1期11卷 58-70页

作者： Tatjana Nikolic Dowty Movita Margaretha EH Lambers Claudia Ribeiro de Almeida] Paula Biesta Kim Kreefft Marjolein JW de Bruijn Ingrid Bergen Niels Galjart Andre Boonstra Rudi Hendriks Department of Pulmonary Medicine Erasmus MC Rotterdam The Netherlands Department of Gastroenterology and Hepatology Erasmus MCRotterdam The Netherlands Department of Cell Biology and Genetics Erasmus MC Rotterdam The Netherlands current address: Dr T Nikolic Department of Immunohematology and Blood Transfusion Leiden University Medical Center Leiden The Netherlands DrCR de Almeida Sir William Dunn School of Pathology University of Oxford Oxford UK. Both authors contributed equally

Macrophages play an important role in immunity and homeostasis. Upon pathogen recognition via specific receptors, they rapidly induce inflammatory responses. This process is tightly controlled at the transcriptional level. The DNA binding zinc-finger protein CCCTC-binding factor （Ctcf） is a crucial regulator of long-range chromatin interactions and coordinates specific communication between transcription factors and gene expression processes. In this study, the Ctcf gene was specifically deleted in myeloid cells by making use of the transgenic Cre-LoxP system. Conditional deletion of the Ctcfgene in myeloid cells induced a mild phenotype in vivo. Ctcf-deficient mice exhibited significantly reduced expression of major histocompatibility complex （MHC） class II in the liver. Ctcf-deficient macrophages demonstrated a normal surface phenotype and phagocytosis capacity. Upon Toll-like receptor （TLR） stimulation, they produced normal levels of the pro-inflammatory cytokines IL-12 and IL-6, but manifested a strongly impaired capacity to produce tumor-necrosis factor （TNF） and IL-IO, as well as to express the IL-IO family members IL-19, IL-20 and IL-24. Taken together, our data demonstrate a role of Ctcf that involves fine-tuning of macrophage function.

关键词： Ctcf IL-IO locus macrophage myeloid TLR

Harnessing self-heating effect for ultralow-crosstalk electro-optic Mach–Zehnder switches

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Photonics Research 2023年第10期11卷 1757-1769页

作者： PENG BAO QIXIANG CHENG JINLONG WEI GIUSEPPE TALLI MAXIM KUSCHNEROV RICHARD V.PENTY Centre for Photonic Systems Electrical Engineering DivisionDepartment of EngineeringUniversity of CambridgeCambridge CB30FAUK Huawei Technologies Duesseldolf GmbH European Research Center80992 MunichGemany current address:Peng Cheng Laboratory Shenzhen 518000China

This paper presents a novel approach to counterbalance free-carrier-absorption(FCA) in electro-optic(E-O)Mach–Zehnder interferometer(MZI) cells by harnessing the self-heating effect. We show insights on crosstalk limitations in MZIs with direct carrier-injection and provide a detailed design methodology on a differential phase shifter pair. Leveraging both free-carrier dispersion(FCD) and self-heating effects, our design enables arbitrary phase tuning with balanced FCA loss in the pair of arms, eliminating the need for additional phase corrections and creating ultralow crosstalk MZI elements. This neat design disengages from the commonly used nested structure, thus providing an opportunity of embedding tunable couplers for correcting imperfect splitting ratios given that only two are needed. We show that with the use of tunable directional couplers, a standard±10 nm process variation is tolerated, while achieving a crosstalk ratio below-40 dB. By direct carrier injection in both arms, the proposed device operates at nanosecond scales and can bring about a breakthrough in the scalability of E-O switch fabrics, as well as other silicon integrated circuits that have stringent requirements for crosstalk leakage.

关键词： crosstalk interferometer breakthrough

Cipaferoids A-C, Three Limonoids Represent Two Different Scaffolds from Cipadessa baccifera

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Chinese Journal of Chemistry 2018年第2期36卷 124-128页

作者： Jinhai Yu Bin Zhou Seema Dalal qunfang Liu Maria B. Cassera Jianmin Yue State Key Laboratory of Drug Research Shanghai Institute of Materia Medica Chinese Academy of Sciences 555 Zu Chong Zhi Road Shanghai 201203 China Department of Biochemistry and the Virginia Tech Center for Drug Discovery MC 0308 Virginia Polytechnic Institute and State University BlacksburgVirginia 24061 the United States. Current address: Department of Biochemis-try and Molecular Biology University of Georgia Athens GA 30602 the Unit-ed States

Three limonoids cipaferoids A-C （1-3） representing two different scaffolds were isolated from Cipadessa baccifera. Their structures were completely assigned by spectroscopic data, CD exciton chirality method, and X-ray crystallography. Compounds 2 and 3 exhibited moderate antimalarial activity with IC50 values of 9.3±0.1 and 14.7±4.8 μmol·L^-1, respectively.

关键词： cipaferoids Cipadessa baccifera limonoids structural elucidation antimalarial activity

C:N:P stoichiometry and nutrient limitation of the soil microbial biomass in a grazed grassland site under experimental P limitation or exces

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Ecological Processes 2012年第1期1卷 66-76页

作者： Bryan S Griffiths Annette Spilles Michael Bonkowski Teagasc Environment Research CentreJohnstown CastleWexfordCoWexfordIreland current address:SAC King's BuildingsWest Mains RoadEdinburgh EH93JGUK Mathematisch Naturwissenschaftliche Fakultät der Universität zu Köln Zoologisches Institut Abt.TerrestrischeÖkologieBiowissenschaftliches ZentrumOtto-Fischer-Str.6D-50674KölnGermany

Introduction:The availability of essential nutrients,such as nitrogen(N)and phosphorus(P),can feedback on soil carbon(C)and the soil microbial *** cycles can be supplemented by agricultural fertiliser addition,and we determined whether the stoichiometry and nutrient limitation of the microbial biomass could be affected by an unbalanced nutrient ***:Samples were taken from a long-term trial(in effect since 1968)with annual applications of 0,15 and 30 kg P ha^(−1) with constant N and *** and microbial biomass CNP contents were measured and nutrient limitation assessed by substrate-induced *** regression and discriminant analyses were used to identify the variables explaining nutrient ***:Soil and biomass CNP increased with increasing P fertiliser,and there was a significant,positive,correlation between microbial biomass P and biomass C,apart from at the highest level of P fertilisation when the microbial biomass was over-saturated with *** molar ratios of C:N:P in the microbial biomass remained constant(homeostatic)despite large changes in the soil nutrient *** growth was generally limited by C and N,except in soil with no added P when C and P were the main limiting nutrients.C,N and P,however,did not explain all the growth limitation on the soils with no added ***:Increased soil C and N were probably due to increased net primary *** results confirm that C:N:P ratios within the microbial biomass were constrained(***)under near optimum soil *** with no added P were characterised by strong microbial P limitation and soils under high P by over-saturation of microorganisms with *** changes in biomass C:P can be indicative of nutrient limitation within a site.

关键词： Carbon Nitrogen Nutrient limitation Phosphorus Soil microbial biomass Stoichiometry

An Artemisia WD40-Repeat Gene Regulates Multiple Cellular Functions in Arabidopsis

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Journal of Biosciences and Medicines 2016年第5期4卷 30-36页

作者： Wei Wang Qing Zhang Dianjing Guo State Key Laboratory of Agrobiotechnology and School of Life Sciences The Chinese University of Hong Kong Hong Kong China current address: Department of Biology New York University New York USA

In this study, we isolated a WD40-repeat gene from Artemisia annua glandular trichomes. This gene shows 69.97% sequence similarity to Arabidopsis TTG1 at aminoacid level. Sub-cellular localization study shows that AaWD40 protein diffuses in both cell nucleus and cytosol. The correct nuclear localization of AaWD40 was observed when co-expressed with AabHLH, a putative A. thaliana AtTTG1 homologue cloned from Artemisia annua glandular trichomes. When AaWD40 gene was ectopically over expressed in Arabidopsis transparent testa glabrous1-1 (ttg1-1) mutants of A. thaliana, PAs production in seeds was restored, and the trichomeless phenotypes of mutant were rescued. Real-time PCR analysis results revealed that ETC1, CPC, TTG2 and BAN (the downstream targets of AtTTG1 depend on regulatory complex), which regulate the epidermal differentiation and anthocyanin biosynthesis were differentially expressed as a result of AaWD40 over expression. Furthermore, the CLV1, CLV2, CLV3 and WUS, which are required to maintain the stem-cell niche of Arabidopsis shoot apex, were also modulated by AaWD40 and Arabidopsis TTG1. The transcriptions of AP2/ERF, bHLH, MYB, WRKY and NACs family proteins, which are mostly involved in defense, stress response and development regulation, were remarkably modulated by AaWD40 over expression. We hypothesize that WD40 repeat proteins act as a crucial factor in regulating a wide variety of cellular functions in A. thaliana.

关键词： WD40 Repeat Protein Glandular Trichome Arabidopsis

Potassium Deficiency Influences Soybean Seed Mineral Compositions and Metabolic Profiles across CO<sub>2</sub>

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American Journal of Plant Sciences 2019年第12期10卷 2113-2133页

作者： Shardendu K. Singh Jinyoung Y. Barnaby Vangimalla R. Reddy Richard C. Sicher Adaptive Cropping Systems Laboratory USDA-ARS Beltsville MD USA School of Environmental and Forest Science University of Washington Seattle WA USA current address: AeroFarms Newark NJ USA

Impacts of potassium (K) deficiency and elevated carbon dioxide (eCO2) on seed constituents have rarely been explored in most crops including soybean. A controlled environment experiment was conducted with soybean grown under a sufficient (5.0 mM) and two deficient (0.50 and 0.02 mM) levels of K fertilization at ambient (aCO2) and eCO2 (400 and 800 μmol·mol-1, respectively). Both treatments significantly affected several constituents, with the K deficiency having stronger impacts than eCO2. Out of 49 seed constituents, K deficiency and eCO2 influenced 41 and 16 constituents, respectively. The K deficiency primarily decreased on average 16 constituents including minerals (e.g., K, P, Mg, Mn, Zn, Fe, B), oil, and essential fatty acids (e.g., linoleic and linolenic acids) but enhanced 25 constituents such as protein, amino acids, simple sugars, and stress-responsive metabolites (e.g., sugar alcohols mannitol and myo-inositol and proline). An accumulation of N while decreased C concentration resulted in the lower C:N ratio in the seeds of K-deficient plants. However, protein:oil, C:K, N:P, and N:K ratios were consistently greater under K deficiency. The eCO2 also decreased minerals such as P, S, Zn, B, and essential fatty acids but enhanced the concentration of six constituents including alanine, oleic acid, fructose, and sugar alcohols across K fertilization. In addition, the impact of eCO2 on several amino acids appeared to be dependent on the severity of K deficiency. For instance, eCO2 decreased essential amino acids (e.g., valine, phenylalanine, isoleucine) in the seeds of severely K-deficient plants but not in the other treatments leading to a K × CO2 interaction. Results showed that CO2 enrichment is likely to exacerbate the decline in the concentration of seed minerals such as P, K, S, Zn and B, essential fatty acids, and amino acids under K limited conditions.

关键词： Amino Acids Carbohydrates Glycine max Mineral Elements Oil Essential Fatty Acids

Electrical and optical characteristics of highly transparent MOVPE-grown AlGaN-based tunnel heterojunction LEDs emitting at 232 nm

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Photonics Research 2021年第6期9卷 1117-1123页

作者： FRANK MEHNKE CHRISTIAN KUHN MARTIN GUTTMANN LUCA SULMONI VERENA MONTAG JOHANNES GLAAB TIM WERNICKE MICHAEL KNEISSL Institute of Solid State Physics Technische Universität Berlin10623 BerlinGermany Ferdinand-Braun-Institut Leibniz-Institut für Höchstfrequenztechnik12489 BerlinGermany current address:School of Electrical and Computer Engineering Georgia Institute of TechnologyAtlantaGeorgia 30332USA

We present the growth and electro-optical characteristics of highly transparent AlGaN-based tunnel heterojunction light-emitting diodes(LEDs)emitting at 232 nm entirely grown by metalorganic vapor phase epitaxy(MOVPE).A GaN:Si interlayer was embedded into a highly Mg-and Si-doped Al_(0.87)Ga_(0.13)N tunnel junction to enable polarization field enhanced *** LEDs exhibit an on-wafer integrated emission power of 77μWat 5 mA,which correlates to an external quantum efficiency(EQE)of 0.29%with 45μWemitted through the bottom sapphire substrate and 32μW emitted through the transparent top *** depositing a highly reflective aluminum reflector,a maximum emission power of 1.73 mW was achieved at 100 mA under pulsed mode operation with a maximum EQE of 0.35%as collected through the bottom substrate.

关键词： heterojunction MOVPE AlGaN