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Parameter estimation in Manneville–Pomeau processes

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Probability, Uncertainty and Quantitative Risk 2023年第2期8卷 213-234页

作者： Barbara P.olbermann Sílvia R.C.lopes artur o.lopes Faculdade de Matemática-PUCRS 90650-002 Porto AlegreRSBrazil Instituto de Matemática e Estatística-UFRGS 91500-900 Porto AlegreRSBrazil

In this paper,we study a class of stochastic processes{X_(t)}t∈N,where X_(t)=φ■T_(s)^(t)(X_(0))is obtained from the iterations of the transformation T_(s),invariant for an ergodic probabilityμ_(s)on[0,1]and a certain constant by partial functionφ:[0,1]→*** consider here the family of transformations T_(s):[0,1]→[0,1]indexed by a parameters>0,known as the Manneville–Pomeau family of *** autocorrelation function of the resulting process decays hyperbolically(or polynomially)and we obtain efficient methods to estimate the parameter s from a finite time *** a consequence,we also estimate the rate of convergence of the autocorrelation decay of these *** compare different estimation methods based on the periodogram function,the smoothed periodogram function,the variance of the partial sum,and the wavelet *** obtain our results we analyzed the properties of the spectral density function and the associated Fourier series.

关键词： Manneville–Pomeau maps Long and not so long dependence Estimation Autocorrelation decay Spectral density function

Securityoffasthandovermechanisminieee802.1xbased Adhocnetwork

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Securityoffasthandovermechanisminieee802.1xbased Adhocnetwor...

作者： Ivandro o.lopes 华中科技大学

学位级别：硕士

Mobile Ad Hoc Network （MANET） is a collection of wireless mobile nodes, dynamically forming a temporary network, whereas each member of this network can directly communicate to each other without relying on any fixed infrastructure such as access point or base station. Securing MANET is a big challenge, mostly because of the dynamic and cooperative nature of these networks. Handover procedure in secure MANET is a relative time consuming phase. Some solutions have been presented in the literature, and it is identified as a big issue, whether the authentication server must be contacted on every handover, or the handover procedures can be independently handled by the authenticators. We propose and evaluate a novel scheme for re-authentication in 802.1X based ad hoc network for fast handover while maintaining the security level achieved by the 802.1X standard. The proposed mechanism aimed to reduce the total handover procedure time, eliminate the time spent for packet exchanged with authentication server in the EAP phase.

关键词：快速切换机制 Ad Hoc网络无线移动节点认证服务器网络安全

Microglial Dystrophy in the Aged and Alzheimer's Disease Brain Is Associated with Ferritin Immunoreactivity

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神经损伤与功能重建 2008年第4期3卷 253-264页

作者： KRYSLAINE o.lopes D.LARRY SPARKS WoLFGANG J.STREIT Department of Neuroscience University of Florida College of MedicineGainesville Sun Health Research Institute Sun City

小胶质细胞变性对认识衰老相关的神经退变和神经退行性疾病的发病机制非常重要。本研究通过铁蛋白免疫组织化学方法来分析非痴呆和阿茨海默病患者大脑中的小胶质细胞形态特征。作者的主要假设为,铁储存蛋白-铁蛋白的表达提高小胶质细胞... 详细信息

小胶质细胞变性对认识衰老相关的神经退变和神经退行性疾病的发病机制非常重要。本研究通过铁蛋白免疫组织化学方法来分析非痴呆和阿茨海默病患者大脑中的小胶质细胞形态特征。作者的主要假设为,铁储存蛋白-铁蛋白的表达提高小胶质细胞对退化的敏感性,尤其是在老年大脑中,因为衰老的小胶质细胞越来越无力维持铁环境稳定,而游离铁可促进氧化损伤。在24例34-97岁的病例中,小胶质细胞对铁蛋白的免疫反应被发现组成一个较大的HLA-DR抗体标记的小胶质细胞池。在老年尤其是AD大脑中,铁蛋白阳性的大部分小胶质细胞呈现出异常的形态学变化,即营养不良。铁蛋白阳性的营养不良小胶质细胞和AD组织中的老年斑之间并未发现空间相关性。对平均死亡时间(10.94±5.69)h的人脑组织的研究显示,小胶质细胞营养不良的出现不依赖于死亡时间,因而不是组织自溶的产物。这些结果均提示,包含铁储存和新陈代谢的小胶质细胞的变性可能是通过其高暴露于氧化应激。作者推论,铁蛋白免疫组织化学法可能是检测人脑小胶质细胞退行性变的有效方法。

关键词：小胶质细胞变性衰老铁老化

Plant-based pecan nut cake beverage enrichment of phytochemicals and antioxidant properties using multi-stage block freeze concentration

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Food Production, Processing and Nutrition 2022年第1期4卷 433-446页

作者： Laércio Galvão Maciel Gerson lopes Teixeira Department of Food Science and Technology Federal University of Santa Catarina88034-001 FlorianópolisSCBrazil

Pecan nut (Carya illinoinensis) processing to obtain oil generates circa 37% of press cake, which is currently underuti-lized and primarily employed as animal feed. Due to its nutritional- and bioactive-rich composition, pecan nut cake (PNC) can be used as raw material for plant-based beverages, whose properties may be enhanced using a non-ther-mal technology based on block freeze concentration (BFC). The effect of five-stage BFC on total solids content (TSC), pH, color parameters, retention of phytochemicals, and the antioxidant activity (AA) of a pecan nut cake beverage (PNB) was assessed in this work. BFC afforded 98% (w/w) solids retention after three stages and 85% efficiency after four stages. The process also provided a 254% concentration factor in stage 5. In the last step, approximately a 64% increase in TSC and a slight decrease (7.3%) in pH compared to the control PNB was observed. In addition, total phenolic compounds, condensed tannins, total flavonols, and AA were significantly (P oved after the BFC, resulting in a 2.6-10.2- and 1.9-5.8-fold increase in phytochemicals and antioxidants, respectively. on the other hand, BFC caused the darkening of concentrates due to TSC and bioactive compounds retention. The processing strategy evaluated herein indicated a great potential of PNC as a raw material for obtaining high-quality ingredients for the food industry, which may reduce agro-industrial waste production and add value to a coproduct rich in nutrients and biocompounds with potential biological activity.

关键词： Caryaillinoinensis Press cake Waste valorization Plant-based beverage Bioactive compounds Cryoconcentration

Characteristics of Vertical Distributions of Fatty Acids in Surface Sediments of the Yellow Sea and East China Sea

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Journal of ocean University of China 2018年第5期17卷 1123-1134页

作者： lopes Evanildo o. WANG Mengqi CHEN Ying YANG Guipeng DING Haibing College of Chemistry and Chemical Engineering Ocean University of ChinaQingdao 266100China Key Laboratory of Marine Chemistry Theory and Technology Ministry of EducationOcean University of ChinaQingdao 26610Q China China State Shipbuilding Corporation Electronics Technology Co.Ltd. Beijing 100015China Qingdao Collaborative Innovation Center of Marine Science and Technology Ocean University of ChinaQingdao 26610Q China Qingdao National Laboratory of Marine Science and Technology Qingdao 266100China

Fatty acids(FAs) in sediment collected from three different stations in the Yellow Sea and the East China Sea were analyzed for their distributions and to determine evidence of harmful algal blooms in the sediment *** diverse FAs were found in the Yellow Sea(YS) station,whereas in the two stations of the East China Sea(ECS) the FAs were more *** of some FA species in the two ECS stations displayed an occasional surge in their vertical *** highest concentration of FAs was found in the surface layer of station QT3(43.28 μg g^(-1)).Monounsaturated FAs were more susceptible to degradation compared to their saturated counterparts,and changes of 16:0,18:2 and 20:5 accounted for the most variability in total concentrations of FAs as those species made up most of the quantified *** origins of the major fraction of FAs were attributed to autotrophic sources,and bacterial FAs accounted for only a small fraction of the total FAs in the *** availability was a possible regulating factor controlling bacteria abundances in marine sediments in the ECS and the YS.A principal component analysis(PCA) was applied to analyze the FA dataset and to reveal the principal environmental factors that control the composition of FAs in the ***2,which explains 15% of the variance,was estimated to reflect the diagenetic effects on the FA compositional changes in sediments influenced by bacterial degradation.

关键词： fatty acids Yellow Sea East China Sea sediments diagenesis

Chronological Age and Performance in Paralympic Powerlifters: Differences Between Sexes, Competition, and Weight Categories

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Journal of Science in Sport and Exercise 2023年第1期5卷 53-61页

作者： João Paulo.lopes-Silva Dillon Richardson Emerson Franchini Applied Research Group Performance and Health CESMAC University CenterMaceióAlagoasBrazil International Paralympic Committee(IPC) BonnGermany Sport Department School of Physical Education and SportUniversity of Sao PauloSao PauloBrazil

Purpose We quantified the chronological age and performance of Paralympic powerlifters competing at the elite level in the World Championships(WC)and Paralympic Games(PG),and examined the age-related differences between sexes,weight categories,and competition *** This was a retrospective study involving 3107 athletes who took part in the last eight WC and six *** pow-erlifters were divided by sex,chronological age,weight category,and competition *** overall,males were older(33 years)and stronger(lifting 168 kg)than female(32 years and lifting 96 kg,respec-tively)para powerlifters(Powerlifters lifted heavier loads in the PG(174 and 103 kg,respectively)than in WC(163 and 93 kg,respectively)and medallists were younger(31 and 30 years for females and males,respectively)than non-medallists(33 and 32 years for females and males,respectively)(Powerlifters compet-ing in lighter categories were younger when compared to heavier categories(Poad was heavier compared to heavier competitors(Ponclusion our results show that medallists were younger(31 and 30 years)than non-medallists(33 and 32 years)for females and males,respectively.

关键词： Data analysis Para athletes Sports performance Gender

Hyperonic neutron stars: reconciliation between nuclear properties and NICER and LIGo/VIRGo results

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Communications in Theoretical Physics 2022年第1期74卷 57-63页

作者： Luiz L lopes Centro Federal de Educagao Tecnologica de Minas Gerais Campus VIII CEP 37.022-560Varginha-MG-Brasil

Using an extended version of quantum hadrodynamics,I propose a new microscopic equation of state(EoS)that is able to correctly reproduce the main properties of symmetric nuclear matter at the saturation density,as well as produce massive neutron stars and satisfactory results for the radius and the tidal parameter.I show that this EoS can reproduce at least a 2.00 solar mass neutron star,even when hyperons are *** constraints about the radius of a 2.00 M_(⊙) and the minimum mass that enables a direct Urea effect are also checked.

关键词： neutron star nuclear matter tidal deformability DU process hyperons

Are dogs not susceptible to retroviral infections?

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Animal Diseases 2024年第3期4卷 217-223页

作者： Jorge Casseb João Henrique Campos Luciano Rodrigo.lopes Laboratory of Investigation in Dermatology and Immunodefciencies Department of DermatologyUniversity of São Paulo Medical SchoolSão PauloSPBrazil Igen-Institute of Immunogenetics São PauloSPBrazil Bioinformatics and Biomedical Data Science Division Health Informatics DepartmentUniversidade Federal de São Paulo–UNIFESP.Rua Botucatu 862Prédio Leal PradotérreoVila ClementinoCEP 04023-062São PauloSPBrazil

Retroviruses have been proven to cause infections and diseases in a series of mammalian hosts but not in ***,this letter discussed the dog susceptibility to retrovirus infection,encompassing arguments to understand why dogs may have not been infected by retroviruses thus *** potential resistance of retrovirus in dogs enables this provocative short communication to discuss this question,looking at some evolutive *** lineage of canids has shown,throughout its evolutionary history,a smaller accumulation of retroviruses in canid genomes,classifed as endogenous *** this context,the genomes of canids seem to ofer obstacles,which have been evolutionarily conserved,in the face of retroviral infection.

关键词： Retrovirus dogs Endogenous retrovirus

A Differential Evolution Approach for Protein Folding Using a Lattice Model

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Journal of Computer Science & Technology 2007年第6期22卷 904-908页

作者： Heitor Silverio.lopes Reginaldo Bitello Bioinformatics Laboratory Federal University of Technology-ParanáAv.7 de setembro3165 80230-901 CuritibaBrazil

Protein folding is a relevant computational problem in Bioinformatics, for which many heuristic algorithms have been proposed. This work presents a methodology for the application of differential evolution （DE） to the problem of protein folding, using the bi-dimensional hydrophobic-polar model. DE is a relatively recent evolutionary algorithm, and has been used successfully in several engineering optimization problems, usually with continuous variables. We introduce the concept of genotype-phenotype mapping in DE in order to provide a mapping between the real-valued vector and an actual folding. The methodology is detailed and several experiments with benchmarks are done. We compared the results with other similar implementations. The proposed DE has shown to be competitive, statistically consistent and very promising.

关键词： bioinformatics differential evolution evolutionary computation protein folding