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Molecular identification and population dynamics of two species of Pemphigus （Homoptera： Pemphidae） on cabbage

Insect Science 2009年第2期16卷 115-124页

作者： Naiqi Chen Tong-Xian Liu Mamoudou Setamou j. victor french Eliezer S. Louzada Department of Entomology Texas AgriLife Research Texas A&M University System Weslaco Citrus Center Texas A&M University- Kingsville Citrus Center Weslaco TX 78596 USA

The poplar petiole gall aphid, Pemphiguspopulitransversus Riley, has been one of the maj.r pests on cruciferous vegetable in the Rio Grande Valley （LRGV） of Texas since the late 1940s. It normally migrates from poplar trees to cruciferous vegetables in the fall, and migrates back to the trees in early spring of the coming year. Some root-feeding aphids were found on cruciferous vegetables in late spring and early summer in 1998 and the following years. Those aphids have been identified as Pemphigus obesinymphae Moran. This discovery completely changed the current knowledge about the root-feeding aphids on cruciferous vegetables in the LRGV. Due to their small size, morphological and feeding similarities between P. populitransversus and P. obesinymphae, their identification and distinction are difficult. In this study, random amplification of polymorphic DNA （RAPD） and amplified fragment length polymorphism （AFLP） were used to distinguish these two species over a period of time when the two species occurred together, or separately, in cabbage fields. The two species occurred on cabbage at different times of the year, and overlapped from October to j.ne. From May to October, both species migrated to their primary hosts. The apterous aphids found on cabbage in winter contained mainly P. obesinymphae, whereas in early spring more apterous P. populitransversus were recovered. The root-feeding aphids would feed on cabbage plants as long as this host was available even during the hot, dry summer in the LRGV, although their populations were generally low. Both RAPD and AFLP techniques were efficient in discriminating the two species that showed obviously genetic variability. These molecular techniques confirmed the existence of the two aphid species in apterous samples collected from the soil in cabbage fields in the LRGV, and the results performed by RAPD were confirmed by AFLP. Furthermore, the results suggest that RAPD technique was a better choice despite its reproducib

关键词： AFLP cabbage identification RAPD root aphid

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The effect of carbon nanotubes and polypropylene fibers on bond of reinforcing bars in strain resilient cementitious composites

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Frontiers of Structural and Civil Engineering 2016年第2期10卷 214-223页

作者： Souzana P. TASTANI Maria S. KONSTA-GDOUTOS, Stavroula j. PANTAZOPOULOU victor BALOPOULOS Department of Civil Engineering Democritus University oJ Thrace Vas. Sofias Street #12 Xanthi 67100 Greece

Stress transfer between reinforcing bars and concrete is engaged through rib translation relative to concrete, and comprises longitudinal bond stresses and radial pressure. The radial pressure is equilibrated by hoop tension undertaken by the concrete cover. Owing to concrete＇s poor tensile properties in terms of strength and deformability, the equilibrium is instantly released upon radial cracking of the cover along the anchorage with commensurate abrupt loss of the bond strength. Any improvement of the matrix tensile properties is expected to favorably affect bond in terms of strength, resilience to pullout slip, residual resistance and controlled *** aim of this paper is to investigate the local bond of steel bars developed in adverse tensile stress conditions in the concrete cover. In the tests, the matrix comprises a novel, strain resilient cementitious composite （SRCC） reinforced with polypropylene fibers （PP） with the synergistic action of carbon nano-tubes （CNT）. Local bond is developed over a short anchorage length occurring in the constant moment region of a four-point bending short beam. Parameters of investigation were the material structure （comprising a basic control mix, reinforced with CNTs and/or PP fibers） and the age of testing. Accompanying tests used to characterize the cementitious material were also conducted. The test results illustrate that all the benefits gained due to the synergy between PP fibers and CNTs in the matrix, namely the maintenance of the multi-cracking effect with time, the increased strength and deformability as well as the highly increased material toughness, were imparted in the recorded bond response. The local bond response curves thus obtained were marked by a resilient appearance exhibiting sustained strength up to large levels of controlled bar-slip; the elasto-plastic bond response envelope was a result of the confining synergistic effect of CNTs and the PP fibers, and it occurred even without bar yielding.

关键词： carbon nanotubes strain resilient cementitious composite polypropylene fibers tensile bending bond

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CD74 in antigen presentation,inflammation,and cancers of the gastrointestinal tract

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World j.urnal of Gastroenterology 2009年第23期15卷 2855-2861页

作者： Ellen j.Beswick victor E Reyes Department of Pediatrics University of Texas Medical Branch Galveston TX 77555 United States Department of Pediatrics and Microbiology and Immunology University of Texas Medical Branch Galveston TX 77555 United States

CD74 is a protein whose initial role in antigen presentation was recognized two decades ago. Recent studies have revealed that it has additional functions as a receptor for macrophage migration inhibitory factor and as a receptor for an important human pathogen, Helicobacter pylori （H pylon）. The role of CD74 as a receptor is important because after binding of migration inhibitory factor or H pylori, NF-κB and Erkl/2 activation occurs, along with the induction of proinflammatory cytokine secretion. This review provides an up-to-date account of the functions of CD74 and how it might be involved in inflammation and cancer within the gastrointestinal tract.

关键词： CD74 Invariant chain Cancer Inflammation Helicobacterpylori Gastrointestinal tract

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Mass-Based Environmental Factor and Energy Assessment of Microwave-Assisted Synthesized Transition Metal Nanostructures

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American j.urnal of Analytical Chemistry 2024年第6期15卷 201-218页

作者： victor j. Law School of Mechanical and Materials Engineering University College Dublin Dublin Ireland

This paper describes mass-based energy phase-space proj.ction of microwave-assisted synthesis of transition metals (zinc oxide, palladium, silver, platinum, and gold) nanostructures. The proj.ction uses process energy budget (measured in kj. on the horizontal axes and process density (measured in kj.−1) on the vertical axes. These two axes allow both mass usage efficiency (Environmental-Factor) and energy efficiency to be evaluated for a range of microwave applicator and metal synthesis. The metrics are allied to the: second, sixth and eleventh principle of the twelve principle of Green Chemistry. This analytical approach to microwave synthesis (widely considered as a useful Green Chemistry energy source) allows a quantified dynamic environmental quotient to be given to renewable plant-based biomass associated with the reduction of the metal precursors. Thus allowing a degree of quantification of claimed “eco-friendly” and “sustainable” synthesis with regard to waste production and energy usage.

关键词： Microwave-Assisted Synthesis Transition Metals Nanostructures Allometry Scaling Power-Law Signature Green Chemistry

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Mass Spectrometric Analyses Reveal a Central Role for Ubiquitylation in Remodeling the Arabidopsis Proteome during Photomorphogenesis

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Molecular Plant 2017年第6期10卷 846-865页

作者： victor Aguilar-Hernandez Do-Young Kim Robert j. Stankey Mark Scalf Lloyd M. Smith Richard D. Vierstra Department of Biology Washington University in St. Louis Campus Box 1137 One Brookings Drive St. Louis MO 63130 USA Department of Genetics 425-G Henry Mall Department of Chemistry 1101 University Avenue University of Wisconsin-Madison Madison WI 53706 USA Advanced Bio Convergence Center Pohang Technopark Gyeong-Buk South Korea 37668

The switch from skotomorphogenesis to photomorphogenesis is a key developmental transition in the life of seed plants. While much of the underpinning proteome remodeling is driven by light-induced changes in gene expression, the proteolytic removal of specific proteins by the ubiquitin-26S proteasome system is also likely paramount. Through mass spectrometric analysis of ubiquitylated proteins affinity-purified from etiolated Arabidopsis seedlings before and after red-light irradiation, we identified a number of influential proteins whose ubiquitylation status is modified during this switch. We observed a substantial enrichment for proteins involved in auxin, abscisic acid, ethylene, and brassinosteroid signaling, peroxisome function, disease resistance, protein phosphorylation and light perception, including the phytochrome （Phy） A and phototropin photoreceptors. Soon after red-light treatment, PhyA becomes the dominant ubiquitylated species, with ubiquitin attachment sites mapped to six lysines. A PhyA mutant protected from ubiquitin addition at these sites is substantially more stable in planta upon photoconversion to Pfr and is hyperactive in driving photomorphogenesis. However, light still stimulates ubiquitylation and degradation of this mutant, implying that other attachment sites and/or proteolytic pathways exist. Collectively, we expand the catalog of ubiquitylation targets in Arabidopsis and show that this post- translational modification is central to the rewiring of plants for photoautotrophic growth.

关键词： Arabidopsis ubiquitin mass spectrometry photomorphogenesis phytochrome degradation

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Immune response to H pylori

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World j.urnal of Gastroenterology 2006年第35期12卷 5593-5598页

作者： Giovanni Suarez victor E Reyes Ellen j.Beswick Department of Pediatrics University of Texas Medical Branch Galveston TX 77555 United States Department of Microbiology and Immunology University of Texas Medical Branch Galveston TX 77555United StatesDepartment of Microbiology and Immunol-ogy University of Texas Medical Branch Galveston TX 77555 United States

The gastric mucosa separates the underlying tissue from the vast array of antigens that traffic through the stomach lumen. While the extreme pH of this environment is essential in aiding the activation of enzymes and food digestion, it also renders the gastric epithelium free from bacterial colonization, with the exception of one important human pathogen, Hpylori. This bacterium has developed mechanisms to survive the harsh environment of the stomach, actively move through the mucosal layer, attach to the epithelium, evade immune responses, and achieve persistent colonization. While a hallmark of this infection is a marked inflammatory response with the infiltration of various immune cells into the infected gastric mucosa, the host immune response is unable to clear the infection and may actually contribute to the associated pathogenesis. Here, we review the host responses involved during infection with Hpylori and how they are influenced by this bacterium.

关键词： H pylori Immune response T cell Dendritic cells

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H pylori and host interactions that influence pathogenesis

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World j.urnal of Gastroenterology 2006年第35期12卷 5599-5605页

作者： Ellen j.Beswick Giovanni Suarez victor E Reyes Departments of Pediatrics Microbiology and Immunology University of Texas Medical Branch Galveston TX 77555 United States

H py/ori is probably the most prevalent human pathogen worldwide. Since it was initially suggested in 1983 by Marshall and Warren to be implicated in gastritis and peptic ulcer disease, H pylori has also been implicated in gastric carcinoma and was classified as a class I carcinogen. In the last two decades, a noteworthy body of research has revealed the multiple processes that this gram negative bacterium activates to cause gastroduodenal disease in humans. Most infections are acquired early in life and may persist for the life of the individual. While infected individuals mount an inflammatory response that becomes chronic, along with a detectable adaptive immune response, these responses are ineffective in clearing the infection. Hpylori has unique features that allow it to reside within the harsh conditions of the gastric environment, and also to evade the host immune response. In this review, we discuss the various virulence factors expressed by this bacterium and how they interact with the host epithelium to influence pathogenesis.

关键词： H pylori Gastric cancer Immune response Vacuolating cytotoxin

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Assessment of k–ε models using tetrahedral grids to describe the turbulent flow field of a PBT impeller and validation through the PIV technique

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Chinese j.urnal of Chemical Engineering 2018年第5期26卷 942-956页

作者： victor X. Mendoza-Escamilla Alej.ndro Alonzo-Garcia Helvio R. Mollinedo Israel Gonzalez-Neria j. Antonio Yanez-Varela Sergio A. Martinez-Delgadillo Depto. Electronica Universidad Autonoma Metropolitana Azcapotzalco Av. San Pablo 180 Azcapotzalco CP 07740 Mexico D.F. Mexico CONACyT-Centro de Ingenierfa y Desarrollo Industrial Av. Piaya Pie de la Cuesta 702 Desarrollo San Pablo 76125 Queretaro Qro. Mexico UPIITA Instituto Politecnico Nacional Av. IPN 2580 G.A. Madero CP 07340 Mexico D.F. Mexico Depto. Ciencias Basicas Universidad Autonoma Metropolitana Azcapotzalco Av. San Pablo 180 Azcapotzalco CP 07740 Mexico D.F Mexico

In turbulence modeling, the RNG and Realizable models have important improvements in the turbulent production and dissipation terms in comparison to the Standard. The selection of the appropriate turbulence model has an impact on the convergence and solution in STRs, and they are used in mixing, multiphase modeling or as starting solution of transient models as DES and LES. Although there are several studies with the pitched blade turbine(PBT) impeller, most of them used the Standard model as representative of all k–ε models, using structured hexahedral grids composed of low number of cells, and in some cases under axial symmetry ***, in this work the assessment of the Standard, RNG and Realizable models to describe the turbulent flow field of this impeller, using the Multiple Reference Frame(MRF) and Sliding Mesh(SM) approaches with tetrahedral domains in dense grids, is presented. This kind of cell elements is especially suitable to reproduce complex geometries. Flow velocities and turbulent parameters were verified experimentally by PIV and torque measurements. The three models were capable of predicting fairly the pumping number, the power number based on torque, and velocities. Although the RNG improved the predictions of the turbulent kinetic energy and dissipation rate, the Realizable model presented better performance for both approaches. All models failed in the prediction of the total dissipation rate, and a dependence of its value on the number of cells for the MRF was found.

关键词： Tetrahedral grids PIV Turbulent flow k-ε models Stirred vessel

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Stereodynamics of O（^3P）＋H2 at Scattering Energies of 0.5, 0.75, and 1.0 eV

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Chinese j.urnal of Chemical Physics 2010年第2期23卷 149-154,I0001页

作者： victor Wei-keh Wu 国立高雄应用科技大学、化学材料工程系高雄80782 胜利者基础研究实验室、比勒费尔德D-33602 德国

Quasiclassical traj.ctory calculation of the title reaction O（^3P）＋H2→OH＋H at three different scattering energies of 0.5, 0.75, and 1.0 eV on the lowest electronic potential energy surface 1^3A＂ has been done. Distribution P（θr） of polar angles between the relative velocityk of the reactant and rotational angular momentum vector j. of the product, distribution P（φr） of the azimuthal as well as dihedral angles correlating k-k＇-j., 3-dimensional distri-bution, and polarization-dependent differential cross sections （PDDCSs）dependent upon the scattering angle of the product molecule OH between the relative velocity k of the reactant and k＇ of the product at different scattering energies of 0.5, 0.75, and 1.0 eV are presented and discussed.

关键词： Quasiclassical traj.ctory calculation Stereodynamics Alignment Rotational angular momentum Polarization-dependent differential cross section O+H2 reaction

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Finite Element Analysis of Residual Stress and Distortion in an Eccentric Ring Induced by Quenching

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材料热处理学报 2004年第05B期25卷 746-751页

作者： LI M. victor Portland State University PO Box 751-ME Portland OR 97207-075J USA

The residual stresses and distortion induced by quenching in an eccentric ring were investigated in this study with finite element method. The ring was made of AISI 52100 steel. A fully coupled 3D temperature-displacement analysis was performed to simulate heat transfer, phase transformations, and mechanical stresses and strains during the heating and subsequent quenching processes. Commercial FEA package ABAQUS/Standard 6.4 was used for the analyses along with user subroutines developed by the authors to model the thermal and mechanical constitutive behavior. The simulation results show that transformation plasticity plays an important role on the residual stress distribution.

关键词：残余应力有限元分析变形偏心环相变塑性

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