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Planar matrices and arrays of Feynman diagrams

Communications in Theoretical Physics 2024年第3期76卷 15-32页

作者： Freddy Cachazo Alfredo Guevara bruno Umbert Yong Zhang Perimeter Institute for Theoretical Physics WaterlooON N2L 2Y5Canada Department of Physics and Astronomy University of WaterlooWaterlooON N2L 3G1Canada CECs Valdivia y Departamento de Física Universidad de ConcepciónCasilla 160-CConcepciónChile Center for the Fundamental Laws of Nature Society of Fellows and Black Hole InitiativeHarvard UniversityCambridgeMA 02138United States of America Department of Applied Mathematics Western UniversityLondonON N6A 5B7Canada CAS Key Laboratory of Theoretical Physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China School of Physical Sciences University of Chinese Academy of SciencesNo.19A Yuquan RoadBeijing 100049China

Recently,planar collections of Feynman diagrams were proposed by Borges and one of the authors as the natural generalization of Feynman diagrams for the computation of k=3 biadjoint *** collections are one-dimensional arrays of metric trees satisfying an induced planarity and compatibility *** this work,we introduce planar matrices of Feynman diagrams as the objects that compute k=4 biadjoint *** are symmetric matrices of metric trees satisfying compatibility *** introduce two notions of combinatorial bootstrap techniques for finding collections from Feynman diagrams and matrices from *** applications of the first,we find all 693,13612 and 346710 collections for(k,n)=(3,7),(3,8)and(3,9),*** applications of the second kind,we find all90608 and 30659424 planar matrices that compute(k,n)=(4,8)and(4,9)biadjoint amplitudes,*** an example of the evaluation of matrices of Feynman diagrams,we present the complete form of the(4,8)and(4,9)biadjoint *** also start a study of higher-dimensional arrays of Feynman diagrams,including the combinatorial version of the duality between(k,n)and(n-k,n)objects.

关键词： Feynman diagrams biadjoint amplitudes tropical Grassmannian

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Flow characterization and dilution effects of N_2 and CO_2 on premixed CH_4/air flames in a swirl-stabilized combustor

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Chinese Physics B 2014年第3期23卷 382-395页

作者：韩乐蔡国飙王海兴 Renou bruno Boukhalfa Abdelkrim School of Astronautics Beijing University of Aeronautics and Astronautics UMR 6614 CORIA INSA de Rouen Avenue de l’UniversitèBP08 76801 Saint-Etienne du Rouvray France

Numerically-aided experimental studies are conducted on a swirl-stabilized combustor to investigate the dilution effects on flame stability, flame structure, and pollutant emissions of premixed CH4/air flames. Our goal is to provide a systematic assessment on combustion characteristics in diluted regimes for its application to environmentally-friendly approaches such as biogas combustion and exhanst-gas recirculation technology. Two main diluting species, N2 and CO2, are tested at various dilution rates. The results obtained by means of optical diagnostics show that five main flame regimes can be observed for Nz-diluted flames by changing excess air and dilution rate. CO2-diluted flames follow the same pattern evolution except that all the domains are shifted to lower excess air. Both N2 and CO2 dilution affect the lean blow- out （LBO） limits negatively. This behavior can be counter-balanced by reactant preheating which is able to broaden the flammability domain of the diluted flames. Flame reactivity is degraded by increasing dilution rate. Meanwhile, flames are thickened in the presence of both diluting species. NOx emissions are significantly reduced with dilution and proved to be relevant to flame stability diagrams： slight augmentation in NOx emission profiles is related to transitional flame states where instability occurs. Although dilution results in increase in CO emissions at certain levels, optimal dilution rates can still be proposed to achieve an ideal compromise.

关键词： dilution effect premixed combustion swirl flow optical diagnostics

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Perception of Disasters and Land Reclamation in an Informal Settlement on Reclaimed Land:Case of the BASECO Compound,Manila,the Philippines

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International Journal of Disaster Risk Science 2020年第5期11卷 640-654页

作者： Ven Paolo bruno Valenzuela Miguel Esteban Onuki Motoharu Graduate Program in Sustainability Science-Global Leadership Initiative The University of TokyoKashiwaChiba 277-8563Japan Department of Civil and Environmental Engineering Waseda UniversityTokyo 169-8555Japan

Southeast Asia's coastal urban areas continue to grow,with land reclamation fast becoming an important option for megacities to address issues of economic growth and increasing population *** are divided over the advantages and disadvantages of land reclamation,though this process continues unabated,exposing settlements to coastal *** Bataan Shipping and Engineering Company(BASECO)compound is an informal settlement on reclaimed land in Manila,the *** informal coastal settlements view disaster risk and their more pressing socioeconomic needs is crucial to understanding the potentials and repercussions of land *** a topographic survey,a questionnaire survey,and the protective action decision model,this study explored the perception of disasters and land reclamation of informal settlers who are living on reclaimed *** study found that people are aware of disaster risks,but are more concerned with everyday *** are divided on the issue of further land *** on the original non-reclaimed land view it as a coastal defense,while those on reclaimed land fear potential *** this,all locations in the community are concerned with the loss of jobs,economic opportunities,and eviction,rather than potential disasters.

关键词： Coastal hazards Flooding Informal settlements Land reclamation Philippines Risk perception Urbanization

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Long-term Regional Dynamic Sea Level Changes from CMIP6 Projections

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Advances in Atmospheric Sciences 2021年第2期38卷 157-167页

作者： bruno FERRERO Marcos TONELLI Fernanda MARCELLO Ilana WAINER University of São Paulo São Paulo 05508120Brazil

Anthropogenic climate forcing will cause the global mean sea level to rise over the 21st ***,regional sea level is expected to vary across ocean basins,superimposed by the influence of natural internal climate ***,we address the detection of dynamic sea level(DSL)changes by combining the perspectives of a single and a multimodel ensemble approach(the 50-member CanESM5 and a 27-model ensemble,respectively,all retrieved from the CMIP6 archive),under three CMIP6 projected scenarios:SSP1-2.6,SSP3-7.0 and *** ensemble analysis takes into account four key metrics:signal(S),noise(N),S/N ratio,and time of emergence(ToE).The results from both sets of ensembles agree in the fact that regions with higher S/N(associated with smaller uncertainties)also reflect earlier *** DSL signal is projected to emerge in the Southern Ocean,Southeast Pacific,Northwest Atlantic,and the *** common for both sets of ensemble simulations show that while S progressively increases with increased projected emissions,N,in turn,does not vary substantially among the SSPs,suggesting that uncertainty arising from internal climate variability has little dependence on changes in the magnitude of external *** changes are greater and quite similar for the scenarios SSP3-7.0 and SSP5-8.5 and considerably smaller for the SSP1-2.6,highlighting the importance of public policies towards lower emission scenarios and of keeping emissions below a certain threshold.

关键词： dynamic sea level CMIP6 sea level rise signal-to-noise time of emergence

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Abdominal pain related to adulterated opium:An emerging issue in drug addicts

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World Journal of Psychiatry 2020年第5期10卷 95-100页

作者： Maryam Vahabzadeh bruno Megarbane Medical Toxicology Research Center Mashhad University of Medical SciencesMashhadIran Department of Medical and Toxicological Critical Care Lariboisière HospitalParis-Diderot UniversityINSERM UMRS-1144Paris 75010France

Lead may contaminate opium,heroin and illicit opiates and is particularly observed in ***,a natural heavy metal is able to interfere with several organ functions after ingestion or *** poisoning manifestations are non-specific and thus lead poisoning remains difficult to *** the manifestations,abdominal pain is almost the most frequent symptom causing patients to seek medical *** patients with a history of opium addiction presenting with moderate-to-severe abdominal pain,lack of diagnosis of lead toxicity may thus result in time-consuming and unnecessary medical work-ups that can end up in invasive *** paper aims to briefly review abdominal pain as an emergency issue and the leading symptom of lead poisoning that brings most of the patients to healthcare *** published adult cases and case series of opium addicts admitted with abdominal pain due to leadadulterated opium consumption have been reviewed.A trend of increasing numbers of lead poisoning cases has recently emerged among opium addicts in *** to the non-specific manifestations and hazardous effects,psychiatrists and emergency physicians should consider lead poisoning in patients with a past or present history of opium addiction referred for acute abdominal pain,particularly in case of colicky abdominal pain.

关键词： Addiction Opium Lead Poisoning Abdominal pain Toxicity

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Dissipation and amplification management in an electrical model of microtubules: Hybrid behavior network

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Chinese Physics B 2023年第11期32卷 392-400页

作者： Sedric Ndoungalah Guy Roger Deffo Arnaud Djine Serge bruno Yamgoue Department of Physics Faculty of ScienceUniversity of BamendaP.O.Box 39 BamendaCameroon Research Unit of Automation and Applied Computers(UR-AIA) Department of Electrical EngineeringIUT-FV of BandjounUniversity of DschangBP 134BandjounCameroon Department of Physics Higher Teacher Training College BambiliThe University of BamendaP.O.Box 39 BamendaCameroon

The control of dissipation and amplification of solitary waves in an electrical model of a microtubule is *** model consists of a shunt nonlinear resistance–capacitance(J(V)–C(V)) circuit and a series resistance–inductance(R–L) circuit. Through linear dispersion analysis, two features of the network are found, that is, low bandpass and bandpass filter characteristics. The effects of the conductance’s parameter λ on the linear dispersion curve are also analyzed. It appears that an increase of λ induces a decrease(an increase) of the width of the bandpass filter for positive(negative) values of λ. By applying the reductive perturbation method, we derive the equation governing the dynamics of the modulated waves in the system. This equation is the well-known nonlinear Schr?dinger equation extended by a linear term proportional to a hybrid parameter σ, i.e., a dissipation or amplification coefficient. Based on this parameter, we successfully demonstrate the hybrid behavior(dissipation and amplification) of the system. The exact and approximate solitary wave solutions of the obtained equation are derived, and the effects of the coefficient σ on the characteristic parameters of these waves are investigated. Using the analytical solutions found, we show numerically that the waves that are propagated throughout the system can be dissipated, amplified, or remain stable depending on the network parameters. These results are not only in agreement with the analytical predictions, but also with the existing experimental results in the literature.

关键词： microtubule dissipation and amplification hybrid behavior solitary wave solutions

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Investigation of bright and dark solitons in α,β-Fermi Pasta Ulam lattice

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Chinese Physics B 2021年第2期30卷 211-219页

作者： Nkeh Oma Nfor Serge bruno Yamgoué Francois Marie Moukam Kakmeni Department of Physics Higher Teacher Training College BambiliThe University of BamendaP.O.Box 39Bambili-Cameroon Complex Systems and Theoretical Biology Group Laboratory of Research on Advanced Materials and Nonlinear Science(LaRAMaNS)Department of PhysicsFaculty of ScienceUniversity of BueaP.O.Box 63 Buea-Cameroon

We consider the Hamiltonian ofα,β-Fermi Pasta Ulam lattice and explore the Hamilton-Jacobi formalism to obtain the discrete equation of *** using the continuum limit approximations and incorporating some normalized parameters,the extended Korteweg-de Vries equation is obtained,with solutions that elucidate on the Fermi Pasta Ulam *** further derive the nonlinear Schrodinger amplitude equation from the extended Korteweg-de Vries equation,by exploring the reductive perturbative *** dispersion and nonlinear coefficients of this amplitude equation are functions of theαandβparameters,with theβparameter playing a crucial role in the modulational instability analysis of the ***βgreater than or equal to zero,no modulational instability is observed and only dark solitons are identified in the *** forβless than zero,bright solitons are traced in the lattice for some large values of the *** of numerical simulations of both the Korteweg-de Vries and nonlinear Schr¨odinger amplitude equations with periodic boundary conditions clearly show that the bright solitons conserve their amplitude and shape after collisions.

关键词： Fermi Pasta Ulam paradox bright dark

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Cytomegalovirus and ulcerative colitis:Place of antiviraltherapy

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World Journal of Gastroenterology 2016年第6期22卷 2030-2045页

作者： Sylvie Pillet bruno Pozzetto Xavier Roblin Groupe Immunitédes Muqueuses et Agents Pathogènes(GIMAP)-EA3064 Faculty of Medicine of Saint-EtienneUniversity of Lyon69365 Lyon Cedex 7France Laboratory of Infectious Agents and Hygiene University Hospital of Saint-Etienne42025 Saint-Etienne Cedex 2France Department of Gastroenterology University Hospital of Saint-Etienne42025 Saint-Etienne Cedex 2France

The link between cytomegalovirus(CMV) infection and inflammatory bowel diseases remains an important subject of debate. CMV infection is frequent in ulcerative colitis(UC) and has been shown to be potentially harmful. CMV reactivation needs to be diagnosed using methods that include in situ detection of viral markers by immunohistochemistry or by nucleic acid amplification techniques. Determination of the density of infection using quantitative tools(numbers of infected cells or copies of the genome) is particularly important. Although CMV reactivation can be considered as an innocent bystander in active flareups of refractory UC, an increasing number of studies suggest a deleterious role of CMV in this situation. The presence of colonic CMV infection is possibly linked to a decreased response to steroids and other immunosuppressive agents. Some treatments, notably steroids and cyclosporine A, have been shown to favor CMV reactivation, which seems not to be the case for therapies using anti-tumor necrosis factor drugs. According to these findings, in flare-ups of refractory UC, it is now recommended to look for the presence of CMV reactivation by using quantitative tools in colonic biopsies and to treat them with ganciclovir in cases of high viral load or severe disease.

关键词： Human cytomegalovirus Ulcerative colitis Inflammatory bowel disease Ganciclovir Viral load Flare-up Inflammation Intestinal mucosa Quantitativepolymerase chain reaction

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Tracking Co-evolution of Behavior and Relationships with Mobile Phones

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Tsinghua Science and Technology 2012年第2期17卷 136-151页

作者： Wen Dong bruno Lepri Sandy Pentland MIT Media Laboratory Cambridge MA 02142 USA FBK Povo-Trento Italy

The co-evolution of social relationships and individual behavior in time and space has important implications, but is poorly understood because of the difficulty of closely tracking the everyday life of a com- plete community. We offer evidence that relationships and behavior co-evolve in a student dormitory, based on monthly surveys and location tracking through resident cellular phones over a period of nine months. We demonstrate that a Markov jump process could capture the co-evolution in terms of the rates at which resi- dents visit places and friends. Our co-evolution model will be useful in bridging sensor networks data and organizational dynamics theories, simulating different ways to shape behavior and relationships, and turning mobile phone data into data products.

关键词： social computing human dynamics living labs sensor networks organizational dynamics stochastic process multi-agent model

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Treatment of Helicobacter pylori infection in atrophic gastritis

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World Journal of Gastroenterology 2018年第22期24卷 2373-2380页

作者： Edith Lahner Marilia Carabotti bruno Annibale Medical-Surgical Department of Clinical Sciences and Translational Medicine Sant'Andrea Hospital University Sapienza

Helicobacter pylori(Hp) is a major human pathogen causing chronic, progressive gastric mucosal damage and is linked to gastric atrophy and cancer. Hp-positive individuals constitute the major reservoir for transmission of infection. There is no ideal treatment for Hp. Hp infection is not cured by a single antibiotic, and sometimes, a combined treatment with three or more antibiotics is ineffective. Atrophic gastritis(AG) is a chronic disease whose main features are atrophy and/or intestinal metaplasia of the gastric glands, which arise from long-standing Hp infection. AG is reportedly linked to an increased risk for gastric cancer, particularly when extensive intestinal metaplasia is present. Active or past Hp infection may be detected by conventional methods in about two-thirds of AG patients. By immunoblotting of sera against Hp whole-cell protein lysates, a previous exposure to Hp infection is detected in all AG patients. According to guidelines, AG patients with Hp positivity should receive eradication treatment. The goals of treatment are as follows:(1) Cure of infection, resolution of inflammation and normalization of gastric functions;(2) possible reversal of atrophic and metaplastic changes of the gastric mucosa; and(3) prevention of gastric cancer. An ideal antibiotic regimen for Hp should achieve eradication rates of approximately 90%, and complex multidrug regimens are required to reach this goal. Amongst the factors associated with treatment failure are high bacterial load, high gastric acidity, Hp strain, smoking, low compliance, overweight, and increasing antibiotic resistance. AG, when involving the corporal mucosa, is linked to reduced gastric acid secretion. At a non-acidic intra-gastric p H, the efficacy of the common treatment regimens combining proton pump inhibitors with one or more antibiotics may not be the same as that observed in patients with Hp gastritis in an acid-producing stomach. Although the efficacy of these therapeutic regimens has

关键词： Atrophic gastritis Preneoplastic condition Intestinal metaplasia Helicobacter pylori Eradication treatment

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