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Stellar Structure Model in the Post-Newtonian Approximation

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Research in Astronomy and Astrophysics 2022年第12期22卷 232-238页

作者： gilberto M.kremer Departamento de Física Universidade Federal do ParanáCuritiba 81531Brazil

In this work the influence of the post-Newtonian corrections to the equations of stellar structure are *** post-Newtonian Lane-Emden equation follows from the corresponding momentum density balance *** a polytropic equation of state the solutions of the Lane-Emden equations in the Newtonian and post-Newtonian theories are determined and the physical quantities for the Sun,the white dwarf Sirius B and neutron stars with masses M■1.4 M_(⊙),1.8 M_(⊙)and 2.0 M_(⊙)are *** is shown that the post-Newtonian corrections to the fields of mass density,pressure and temperature are negligible for the Sun and Sirius B,but for stars with strong fields the differences become *** the neutron stars analyzed here the central pressure and the central temperature which follow from the post-Newtonian Lane-Emden equation are about fifty to sixty percent greater than those of the Newtonian theory and the central mass density is about three to four percent smaller.

关键词： stars:neutron stars:fundamental parameters hydrodynamics

Stellar structure model in hydrostatic equilibrium in the context of f(R)-gravity

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Research in Astronomy and Astrophysics 2017年第12期17卷 31-40页

作者： Raíla Andr gilberto M.kremer Departamento de Fisica Universidade Federal do Parana81531-980 CuritibaBrazil Manipal Centre for Natural Sciences Manipal UniversityManipal 576104India

In this work we present a stellar structure model from the f（R）-gravity point of view capable of describing some classes of stars（white dwarfs, brown dwarfs, neutron stars, red giants and the Sun）. This model is based on f（R）-gravity field equations for f（R） = R ＋ f2R2, hydrostatic equilibrium equation and a polytropic equation of state. We compare the results obtained with those found by Newtonian theory. It has been observed that in these systems, where high curvature regimes emerge,stellar structure equations undergo modifications. Despite the simplicity of this model, the results are satisfactory. The estimated values of pressure, density and temperature of the stars are within those determined by observations. This f（R）-gravity model has proved to be necessary to describe stars with strong fields such as white dwarfs, neutron stars and brown dwarfs, while stars with weaker fields, such as red giants and the Sun, are best described by Newtonian theory.

关键词： cosmology:theory stars:general massive brown dwarfs white dwarfs neutron

Human endogenous retroviruses: ammunition for myeloid cells in neurodegenerative diseases?

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Neural Regeneration Research 2020年第6期15卷 1043-1044页

作者： Joel Gruchot David kremer Patrick Küry Department of Neurology NeuroregenerationMedical FacultyHeinrich-Heine-University

Activation of myeloid cells by human endogenous retroviral entities:While the exact causes of neurological diseases such as multiple sclerosis(MS)or amyotrophic lateral sclerosis(ALS)are still elusive,there is evidence of a new category of pathogenic elements called human endogenous retroviruses(HERVs)which seem to contribute to their evolution and progression by exerting inflammatory and degenerative effects(Kury et al.,2018).HERVs are ancient retroviral elements which account for up to 8%of the human genome and it is known that environmental factors can trigger their(re-)expression(Kury et al.,2018).The resulting production of viral particles and/or proteins,especially from members of the HERV-W and HERV-K family,is strongly correlated with the onset and progression of neurological diseases,such as MS and ALS(Kury et al.,2018).

关键词： endogenous diseases al.

Exclusion of tourist species from assemblages in ecological studies:a methodological approach using spiders

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Ecological Processes 2022年第1期11卷 825-844页

作者： María Florencia Nadal Alda González gilberto Avalos Consejo Nacional de Investigaciones Científicas y Técnicas(CONICET) Buenos AiresArgentina Laboratorio de Biología de los Artrópodos Facultad de Ciencias Exactas y Naturales y AgrimensuraUniversidad Nacional del NordesteAvenida Libertad 54703400 CorrientesArgentina Centro de Estudios Parasitológicos y de Vectores(CEPAVE-UNLP) Boulevard 120 s/n(e/60-64)1900 La PlataArgentina

Background:The exclusion of tourist species from samples is important to avoid bias in community ***,in practice,this is a very difficult *** commonly used methods by researchers,when the habitat of the species is not known,have several shortcomings:first,they exclude not only pseudo-rare species but also genuinely rare species;second,the results obtained with those methods depend on the abundance of the sampling;and third,they follow very subjective *** aims of this study were:(i)to propose a methodology to detect and exclude habitat-tourist species from the database used to carry out analyses in community ecology studies,(ii)to evaluate how the presence of habitat-tourist species affects the richness estimates,and(iii)to assess the effect of including juvenile spiders in the detection of tourist species and the effect of removing them from the richness ***:When the adult+juvenile dataset was considered,twenty-one habitat-tourist species were detected:8 in forest foliage,11 in forest leaf litter,and 2 in *** habitat-tourist species were considered with this dataset,richness overestimation was significant in foliage and in leaf litter,and the final slopes of the richness estimation curves were significantly steeper in leaf *** only the adult dataset was considered,eight habitat-tourist species were detected:3 in forest foliage,4 in forest leaf litter,and just one in *** inclusion of habitat-tourist species in this dataset showed an overestimation of richness,but this was not ***:The proposed methodology contributes to solving the problem of tourist species,which was recognized as one of the great problems in biodiversity *** study showed that common estimators overestimate species richness when habitat-tourist species are included,leading to erroneous ***,this research showed that the inclusion of juveniles(***)could improve the analysis outputs be

关键词： Pseudo-rare species Richness estimation Indicator value Habitat

Autonomous machine learning for early bot detection in the internet of things

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Digital Communications and Networks 2023年第6期9卷 1301-1309页

作者： Alex medeiros Araujo Anderson Bergamini de Neira Michele Nogueira Department of Informatics Federal University of Parana(UFPR)CuritibaBrazil Department of Computer Science Federal University of Minas Gerais(UFMG)Belo HorizonteBrazil

The high costs incurred due to attacks and the increasing number of different devices in the Internet of Things(IoT)highlight the necessity of the early detection of botnets(i.e.,a network of infected devices)to gain an advantage against ***,early botnet detection is challenging because of continuous malware mutations,the adoption of sophisticated obfuscation techniques,and the massive volume of *** literature addresses botnet detection by modeling the behavior of malware spread,the classification of malicious traffic,and the analysis of traffic *** article details ANTE,a system for ANTicipating botnEt signals based on machine learning *** system adapts itself to different scenarios and detects different types of *** autonomously selects the most appropriate Machine Learning(ML)pipeline for each botnet and improves the classification before an attack effectively *** system evaluation follows trace-driven experiments and compares ANTE results to other relevant results from the literature over four representative datasets:ISOT HTTP Botnet,CTU-13,CICDDoS2019,and *** show an average detection accuracy of 99.06%and an average bot detection precision of 100%.

关键词： Network security Bot early detection Autonomous machine learning Network traffic analysis

Role of Helicobacter pylori in gastric mucosa-associated lymphoid tissue lymphomas

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World Journal of Gastroenterology 2014年第3期20卷 684-698页

作者： Marta-Isabel Pereira José Augusto medeiros Clinical Hematology Department Coimbra University Hospital Center Institute of Physiology Faculty of MedicineUniversity of CoimbraAzinhaga de Santa Comba

Mucosa-associated lymphoid tissue (MALT) lymphoma is an indolent extranodal marginal zone B-cell lymphoma, originating in acquired MALT that is induced in mucosal barriers as part of a normal adaptive immune response to a chronic immunoinflammatory stimulus, most notably chronic infection by Helicobacter pylori (H. pylori). This antigenic stimulation initially leads to lymphoid hyperplasia; the acquisition of additional genetic aberrations culminates in the activation of intracellular survival pathways, with disease progression due to proliferation and resistance to apoptosis, and the emergence of a malignant clone. There are descriptions of MALT lymphomas affecting practically every organ and system, with a marked geographic variability partially attributable to the epidemiology of the underlying risk factors; nevertheless, the digestive system (and predominantly the stomach) is the most frequently involved location, reflecting the gastrointestinal tract’s unique characteristics of contact with foreign antigens, high mucosal permeability, large extension and intrinsic lymphoid system. While early-stage gastric MALT lymphoma can frequently regress after the therapeutic reversal of the chronic immune stimulus through antibiotic eradication of H. pylori infection, the presence of immortalizing genetic abnormalities, of advanced disease or of eradication-refractoriness requires a more aggressive approach which is, presently, not consensual. The fact that MALT lymphomas are rare neoplasms, with a worldwide incidence of 1-1.5 cases per 105 population, per year, limits the ease of accrual of representative series of patients for robust clinical trials that could sustain informed evidence-based therapeutic decisions to optimize the quality of patient care.

关键词： Mucosa-associated lymphoid tissue lymphoma Marginal zone lymphoma Helicobacter pylori Gastric lymphoma Eradication therapy Nuclear factor-kappa B pathway

Drug repurposing for neuroregeneration in multiple sclerosis

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Neural Regeneration Research 2018年第8期13卷 1366-1367页

作者： Patrick Kury David kremer Peter Gottle Department of Neurology Medical Faculty Heinrich-Heine-University Dfisseldorf Germany

Multiple sclerosis （MS） is a chronic, inflammatory and neu- rodegenerative disease of the central nervous system （CNS） affecting at least 2.5 million people worldwide. While the relapsing subtypes of MS are well treatable, the disease per se remains incurable and results in progressive disability. Its etiology is complex and far from being understood.

关键词： CNS

The role of isotropic and anisotropic Hubbard corrections for the magnetic ordering and absolute band alignment of hematite α-Fe2O3(0001)surfaces

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Progress in Natural Science:Materials International 2019年第3期29卷 349-355页

作者： Sateesh Bandaru Ivan Scivetti Chi-Yung Yam gilberto Teobaldi School of Chemical and Bioprocess Engineering University College Dublin Beijing Computational Science Research Center Stephenson Institute for Renewable Energy Department of ChemistryThe University of Liverpool Scientific Computing Department Science and Technology Facilities CouncilDaresbury Laboratory

An isotropic (+U) and anisotropic [+(U-J)] corrected Density Functional Theory study for bulk hematite (α-Fe2O3) was carried out,and several competing terminations of its (0001) surface modeled via slabs of increasing thickness from twelve to thirty-six *** spite of small quantitative differences,the use of either U or (U-J)corrections showed not to qualitatively affect the results of the simulations both for bulkα-Fe2O3and the lowestenergyα-Fe2O3(0001) surface studied,regardless of the thickness of the slab *** energy favored antiferromagnetic ordering of bulkα-Fe2O3was preserved in the relaxed slabs,with the largest surface-induced effects limited to the outermost three Fe-layers in the *** O-and Fe-terminations were found to be energetically favored and ***,fully O-or Fe-terminated surfaces were calculated to be energetically disfavored and ***,the role of Fe-or O-termination for the semiconducting or metallic nature as well as absolute band alignment ofα-Fe2O3(0001) surfaces was analyzed and discussed with respect to the challenges in enhancing the activity ofα-Fe2O3samples as photo-electrode for water splitting.

关键词： Hematite α-Fe2O3 Surfaces Photo-electrodes Density functional theory Electronic properties Magnetic properties

Evaluation of integration methods for hybrid simulation of complex structural systems through collapse

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Earthquake Engineering and Engineering Vibration 2017年第4期16卷 745-759页

作者： Maikol Del Carpio R. M.Javad Hashemi gilberto Mosqueda KPFF Consulting Engineers Los AngelesCA 90045USA Faculty of Science Engineering and TechnologySwinburne University of TechnologyMelbourneVIC 3122Australia Department of Structural Engineering University of CaliforniaSan DiegoCA 92093USA

This study examines the performance of integration methods for hybrid simulation of large and complex structural systems in the context of structural collapse due to seismic excitations. The target application is not necessarily for real-time testing, but rather for models that involve large-scale physical sub-structures and highly nonlinear numerical models. Four case studies are presented and discussed. In the first case study, the accuracy of integration schemes including two widely used methods, namely, modified version of the implicit Newmark with fixed-number of iteration （iterative） and the operator-splitting （non-iterative） is examined through pure numerical simulations. The second case study presents the results of 10 hybrid simulations repeated with the two aforementioned integration methods considering various time steps and fixed-number of iterations for the iterative integration method. The physical sub-structure in these tests consists of a single-degree-of-freedom （SDOF） cantilever column with replaceable steel coupons that provides repeatable highly- nonlinear behavior including fracture-type strength and stiffness degradations. In case study three, the implicit Newmark with fixed-number of iterations is applied for hybrid simulations of a 1：2 scale steel moment frame that includes a relatively complex nonlinear numerical substructure. Lastly, a more complex numerical substructure is considered by constructing a nonlinear computational model of a moment frame coupled to a hybrid model ofa 1：2 scale steel gravity frame. The last two case studies are conducted on the same porotype structure and the selection of time steps and fixed number of iterations are closely examined in pre-test simulations. The generated unbalance forces is used as an index to track the equilibrium error and predict the accuracy and stability of the simulations.

关键词： Hybrid simulation collapse integration methods unbalance forces stability and accuracy numerical errors