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Higgs boson searches at the Tevatron

Frontiers of physics 2013年第3期8卷 270-284页

作者： Gavin j. Davies Imperial College London London SW7 2AZ United Kingdom

This article reviews the Higgs searches at the Tevatron, as presented over the summer of 2012; both standard model （SM） and beyond the standard model （BSM） results are discussed as detailed （arXiv： 1207.0449; Phys. Rev. Lett., 2012, 109： 071804; Phys. Rev. D, 2012, 85： 032005）. We discuss the combination of searches by the CDF and DO Collaborations for the standard model Higgs boson in the mass range 100-200 GeV/c2 produced in the the gg →H, WH, ZH, tfH, and vector boson fusion production modes, and decaying in the H → bb, H → W＋W-, H → ZZ, H →π＋π-, and H →γγ modes. The data, collected at the Fermilab Tevatron collider in p/5 collisions at √s = 1.96 TeV, correspond to integrated luminosities of up to 10 fb^-1. In the absence of signal, we expect to exclude the regions 100 〈 mH 〈 120 GeV/c2 and 139 〈 mH 〈 184 GeV/c2. We exclude, at the 95% C.L., two regions： 100 〈 mH 〈 103 GeV/c2, and 147 〈 mH 〈 180 GeV/c2. We observe a significant excess of events in the mass range between 115 and 140 GeV/c2. The local significance corresponds to 3.0 standard deviations at mH = 120 GeV/ce; the global significance （incorporating the lookelsewhere effect） for such an excess anywhere in the full mass range investigated is approximately 2.5 standard deviations. Furthermore, we separately combine searches for H→ bb-, H → W＋W- and H →γγ. We find that the excess is concentrated in the H →bb channel, appearing in the searches over a broad range of raN; the maximum local significance of 3.3 standard deviations corresponds to a global significance of approximately 3.1 standard deviations. The observed signal strengths in all channels are consistent with the expectation for a standard model Higgs boson at mH = 125 GeV/c2. The production of neutral Higgs bosons in association with b-quarks can be significantly enhanced in various beyond the standard model scenarios, including Supersymmetry. The recent combination of such searches from the two collaborations is discussed.

关键词： Higgs Tevatron

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Laser cut hole matrices in novel armour plate steel for appliqué battlefield vehicle protection

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Defence Technology（防务技术） 2016年第5期12卷 351-359页

作者： Daniel j. THOMAS Engineering Manufacturing Centre College of Engineering Swansea University Swansea UK

During this research, experimental rolled homogeneous armour steel was cast, annealed and laser cut to form an appliqué plate. This Martensitic–Bainitic microstructure steel grade was used to test a novel means of engineering lightweight armour. It was determined that a laser cutting speed of 1200 mm/min produced optimum hole formations with limited distortion. The array of holes acts as a double-edged solution, in that they provide weight saving of 45%, providing a protective advantage and increasing the surface area. Data collected were used to generate laser cut-edge hole proj.ctions in order to identify the optimum cutting speed, edge condition, cost and deformation performance. These parameters resulted in the generation of a surface, with less stress raising features. This can result in a distribution of stress across the wider surface. Provided that appropriate process parameters are used to generate laser cut edges, then the hardness properties of the surface can be controlled. This is due to compressive residual stresses produced in the near edge region as a result of metallurgical transformations. This way the traverse cutting speed parameter can be adj.sted to alter critical surface characteristics and microstructural properties in close proximity to the cut-edge. A relationship was identified between the width of the laser HAZ and the hardness of the cut edge. It is the thickness of the HAZ that is affected by the laser process parameters which can be manipulated with adj.sting the traverse cutting speed.

关键词： Armour steels Defence systems Steel processing Armour engineering

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Large eddy simulation of turbulent diffusion flame combustion using a conserved scalar methodology

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航空动力学报 2007年第7期22卷 1106-1117页

作者： K. Wang Z. Yang j. j. McGuirk Department of Aeronautical and Automotive EngineeringLoughborough University Loughborough Leicestershire LE11 3TU UK

The present paper describes an LES prediction of turbulent diffusion flame combustion in a simplifled axi-symmetric combustor *** calculations are carried out using a well-tested finite volume incompressible LES code which has been modified to handle variable density and reacting *** basic mixture fraction conserved scalar method *** with the chemical state relationships described by fast *** turbulence-chemistry interaction is modelled by a sub-grid PDF method and the PDF is assumed to follow a Beta-function *** LES predictions have been time-averaged over 3.5 flow-through times to generate the mean radial profiles of mixture fraction,product mass fraction,temperature,axial velocity and axial *** agreement of the LES predictions with the experimental data is good for all the above quantities at four different axial positions with largest differences at the first measurement *** LES method also provides information on the unsteady nature of turbulent diffusion *** turbulent reacting flows with large density ratio,it was found necessary to use a relaxation method in order to remove unphysical high-frequency fluctuations and to maintain numerical stability.

关键词：大涡模拟湍流扩散数量方法论弛豫法燃烧理论

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FEARCF a multidimensional free energy method for investigating conformational landscapes and chemical reaction mechanisms

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Science China Chemistry 2011年第12期54卷 1962-1973页

作者： NAIDOO Kevin j. Scientific Computing Research Unit and Department of Chemistry University of Cape Town

The development and implementation of a computational method able to produce free energies in multiple dimensions,descriptively named the free energies from adaptive reaction coordinate forces(FEARCF) method is described in this *** the method can be used to calculate free energies of association,conformation and reactivity here it is shown in the context of chemical reaction landscapes.A reaction free energy surface for the Claisen rearrangement of chorismate to prephenate is used as an illustration of the method's efficient *** simulations are shown to achieve flat histograms for complex multidimensional free energy *** sampling efficiency by which it produces multidimensional free energies is demonstrated on the complex puckering of a pyranose ring,that is described by a three dimensional W(θ1,θ2,θ3) potential of mean force.

关键词： free energy calculations reaction dynamics reaction surfaces multidimensional free energy surfaces

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Mitogen-activated protein kinases mediate the oxidative burst and saponin synthesis induced by chitosan in cell cultures of Panax ginseng

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Science China(Life Sciences) 2004年第4期47卷 303-312页

作者： Steven j. NEILL Centre for Research in Plant Science University of the West of England Bristol Coldharbour Lane Bristol BS16 1QY United Kingdom

Chitosan (CHN) specially induced the activities of 39 kD and 42 kD protein kinases in ginseng cells, which could be suppressed by an inhibitor of mitogen-activated protein kinase (MAPK) pathway, PD98059. The immunoprecipitation (IP) using MAPK antibody or kinase assay in vitro also showed that CHN-induced 42 kD and 39 kD protein kinases belonged to the MAPK family. PD98059 suppressed CHN-induced transcriptions of ginseng squalene synthase and ginseng squalene epoxidase genes (gss and gse), CHN-induced accumulation of β-Amyrin synthase (β-AS) and synthesis of saponin. These results showed that CHN-induced activities of MAPKs were necessary for the CHN-induced saponin synthesis. EGTA and LaCl3 suppressed CHN-induced 39 kD and 42 kD MAPK activities. Ruthenium red (RR) could suppress CHN-induced 39 kD activity. All of them suppressed CHN-induced saponin synthesis. These results indicated that CHN-induced increment of cytosolic calcium was necessary for CHN-induced saponin synthesis. PD98059 also suppressed CHN-induced oxidative burst (including the increment of activity of plasma membrane NADPH oxidase and production of H2O2), but diphenylene iodonium (DPI), dimethylthiourea (DMTU) and 2,5-dihydroxycinnamic acid methyl ester (DHC) could not suppress CHN-induced MAPK activities, which indicated that MAPK was possibly function upstream of CHN-induced oxidative burst. Keywords mitogen-activated protein kinase - chitosan - saponin

关键词： mitogen-activated protein kinase,chitosan,saponin.

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Diabetic retinopathy: recent advances towards understanding neurodegeneration and vision loss

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Science China(Life Sciences) 2015年第6期58卷 541-549页

作者： BARBER Alistair j. Penn State Hershey Eye Center Penn State Hershey College of Medicine Milton S. Hershey Medical Center

Diabetic retinopathy （DR） is one of the most common retinal diseases world-wide. It has a complex pathology that involves the vasculature of the inner retina and breakdown of the blood-retinal barrier. Extensive research has determined that DR is not only a vascular disease but also has a neurodegenerative component and that essentially all types of ceils in the retina are affected, leading to chronic loss of visual function. A great deal of work using animal models of DR has established the loss of neurons and pathology of other cell types, including supporting glial cells. There has also been an increased emphasis on measuring retinal function in the models, as well as further validation and extension of the animal studies by clinical and translational research. This article will attempt to summarize the more recent developments in research towards understanding the complexities of retinal neurodegeneration and functional vision loss in DR.

关键词： retina diabetes neurodegeneration visual function vascular function apoptosis synapse dendrite

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Knowing your enemies： Integrating molecular and ecological methods to assess the impact of arthropod predators on crop pests

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Insect Science 2015年第1期22卷 6-19页

作者： Michael j. Furlong School of Biological Sciences The University of Queensland St Lucia Queensland 4072 Austrafia

The importance of natural enemies as the foundation of integrated pest management （IPM） is widely accepted, but few studies conduct the manipulative field experiments necessary to directly quantify their impact on pest populations in this context. This is particularly true for predators. Studying arthropod predator-prey interactions is inherently difficult： prey items are often completely consumed, individual predator-prey interactions are ephemeral （rendering their detection difficult） and the typically fluid or soft-bodied meals cannot be easily identified visually within predator guts. Serological techniques have long been used in arthropod predator gut-contents analysis, and current enzyme linked immunosorbent assays （ELISA） are highly specific and sensitive. Recently, poly- merase chain reaction （PCR） methods for gut-contents analysis have developed rapidly and they now dominate the diagnostic methods used for gut-contents analysis in field-based research. This work has identified trophic linkages within food webs, determined predator diet breadth and preference, demonstrated the importance of cannibalism and intraguild predation within and between certain taxa, and confirmed the benefits （predator persis- tence） and potential disadvantages （reduced feeding on pest species） of the availability of alternative nonpest prey. Despite considerable efforts to calibrate gut-contents assays, these methods remain qualitative. Available techniques for predator gut-contents analysis can provide rapid, accurate, cost-effective identification of predation events. As such, they perfectly compliment the ecological methods developed to directly assess predator im- pacts on prey populations but which are imperfect at identifying the key predators. These diagnostic methods for gut-contents analysis are underexploited in agricultural research and they are almost never applied in unison with the critical field experiments to measure predator impact. This paper stresses the need fo

关键词： conservation biological control enzyme linked immunosorbent assay (ELISA) gut-contents analysis immunomarking integrated pest management (IPM) polymerase chain reaction (PCR)

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Nuclear Factor-κB:Activation and Regulation during Toll-Like Receptor Signaling

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Cellular & Molecular Immunology 2007年第1期4卷 31-41页

作者： Ruaidhrí j. Carmody Department of Pathology and Laboratory Medicine School of Medicine University of PennsylvaniaPhiladelphia PA 19104 USA 713A Stellar Chance Departmentof Pathology and Laboratory Medicine University of Pennsylvania Schoolof Medicine 422 Curie Blvd.Philadelphia PA 19104 USA

Toll-like receptors （TLRs） recognize distinct microbial components to initiate the innate and adaptive immune responses. TLR activation culminates in the expression of appropriate pro-inflammatory and immunomodulatory factors to meet pathogenic challenges. The transcription factor NF-kB is the master regulator of all TLR-induced responses and its activation is the pivotal event in TLR-mediated activation of the innate immune response. Many of the key molecular events required for TLR-induced NF-r.B activation have been elucidated. However, much remain to be learned about the ability of TLRs to generate pathogen-specific responses using a limited number of transcription factors. This review will focus on our current understanding of NF-kB activation by TLRs and potential mechanisms for achieving a signal-specific response through NF-kB. Cellular ＆ Molecular Immunology. 2007;4（1）：31-41.

关键词： NF-kB toll-like receptor signal transduction innate immunity transcription

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A primitive confuciusornithid bird from China and its implications for early avian flight

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Science China Earth Sciences 2008年第5期51卷 625-639页

作者： Michael j. BENTON Department of Earth Sciences University of Bristol Bristol BS8 1RJ UK

Confuciusornithids, lived from 120–125 million years ago, form a basal bird group and include the oldest birds with horny beaks. Here we describe Eoconfuciusornis zhengi, gen. et sp. nov. from the Early Cretaceous Dabeigou Formatio (131 Ma) in Fengning, Hebei Province, northern China. It represents a new and, more primitive than other known, member of this group and extends the lifespan of this family to 11 Ma, the longest of any known Early Cretaceous avian lineages. Furthermore, Eoconfuciusornis and its relatives present many osteological transformations, such as the size increase of the deltopectoral crest of the humerus and the keel of the sternum, apparently an adaptation toward improved flight in the evolution of the Confuciusornithidae.

关键词： Birds Early Cretaceous confuciusornithids flight

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Selfish genetic elements and the gene＇s-eye view of evolution

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Current Zoology 2016年第6期62卷 659-665页

作者： j. Arvid AGREN Department of Molecular Biology and Genetics Cornell University Ithaca NY 14853-2703 USA

During the last few decades, we have seen an explosion in the influx of details about the biology of selfish genetic elements. Ever since the early days of the field, the gene＇s-eye view of Richard Dawkins, George Williams, and others, has been instrumental to make sense of new empirical observations and to the generation of new hypotheses. However, the close association between selfish genetic elements and the gene＇s-eye view has not been without critics and several other conceptual frameworks have been suggested. In particular, proponents of multilevel selection models have used selfish genetic elements to criticize the gene＇s-eye view. Ln this paper, t first trace the intertwined histories of the study of selfish genetic elements and the gene＇s-eye view and then discuss how their association holds up when compared with other proposed frameworks. Next, using examples from transposable elements and the maj.r transitions, I argue that different models highlight separate aspects of the evolution of selfish genetic elements and that the productive way forward is to maintain a plurality of perspectives. Finally, I discuss how the empirical study of selfish genetic elements has implications for other conceptual issues associated with the gene＇seye view, such as agential thinking, adaptationism, and the role of fitness maximizing models in evolution.

关键词： hierarchy intragenomic conflict levels of selection maj.r transitions multilevel selection Richard Dawkins.

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