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Nonlinear wave dispersion in monoatomic chains with lumped and distributed masses:discrete and continuum models

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Applied Mathematics and Mechanics(English Edition) 2024年第4期45卷 633-648页

作者： E.GHAVANLOO s.el-BORGI school of Mechanical Engineering Shiraz UniversityShiraz 71963-16548Iran Mechanical Engineering Program Texas A&M University at QatarDoha 23874Qatar

The main objective of this paper is to investigate the influence of inertia of nonlinear springs on the dispersion behavior of discrete monoatomic chains with lumped and distributed *** developed model can represent the wave propagation problem in a non-homogeneous material consisting of heavy inclusions embedded in a *** inclusions are idealized by lumped masses,and the matrix between adjacent inclusions is modeled by a nonlinear spring with distributed ***,the model is capable of depicting the wave propagation in bi-material bars,wherein the first material is represented by a rigid particle and the second one is represented by a nonlinear spring with distributed *** discrete model of the nonlinear monoatomic chain with lumped and distributed masses is first considered,and a closed-form expression of the dispersion relation is obtained by the second-order Lindstedt-Poincare method(LPM).Next,a continuum model for the nonlinear monoatomic chain is derived directly from its discrete lattice model by a suitable continualization *** subsequent use of the second-order method of multiple scales(MMs)facilitates the derivation of the corresponding nonlinear dispersion relation in a closed *** novelties of the present study consist of(i)considering the inertia of nonlinear springs on the dispersion behavior of the discrete mass-spring chains;(ii)developing the second-order LPM for the wave propagation in the discrete chains;and(iii)deriving a continuum model for the nonlinear monoatomic chains with lumped and distributed ***,a parametric study is conducted to examine the effects of the design parameters and the distributed spring mass on the nonlinear dispersion relations and phase velocities obtained from both the discrete and continuum *** parameters include the ratio of the spring mass to the lumped mass,the nonlinear stiffness coefficient of the spring,and the wave amplitude.

关键词： nonlinear mass-spring chain discrete model continuum model LindstedtPoincare method(LPM) method of multiple scales(MMs) dispersion phase velocity

Grazing Pressure and Plant Functional Types in Puna Highlands,Northwestern Argentina

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Phyton-International Journal of Experimental Botany 2024年第5期93卷 1067-1080页

作者： Quiroga Mendiola mariana Tálamo Andrés IPAF NOA—INTA(National Institute for Agricultural Technology) Posta de HornillosJujuy4622Argentina Facultad de Ciencias Naturales Universidad Nacional de SaltaSalta4400Argentina Instituto de Bio y Geociencias del NOA(IBIGEO) UNSa-CONICET.Laboratorio de Ecología Aplicada a la Conservación(LEAC)Facultad de Ciencias NaturalesUniversidad Nacional de SaltaSalta4400Argentina Maestría en Gestión Ambiental Escuela de NegociosUniversidad Católica de Salta(UCASAL)Salta4400Argentina

The Puna grasslands support grazing systems that produce meat and wool in multi-species herds,especially from llama(Lama glama)and ***,it is yet unknown whether grazing pressure can modify grassland structure and Plant Functional Types diversity and cover in Puna *** analyzed the relationship between grazing pressure and Plant Functional Types by comparing transects located near stockyards(high grazing pressure)and far from them(low pressure)and by evaluating the relationship between the Plant Functional Types cover to a Grazing Pressure Index(GPI).This index incorporates the heterogeneity of traditional pastoral *** two ecological sites(Ciénego and Tolar),we sampled paired transects(near-far).Plots near and far from corrals were similar in all the variables measured except for plots in Tolar,which tend to have higher total cover,possibly due to fecal fertilization near ***,we recorded an increase in total cover and grass cover at higher GPI in Ciénego,while in Tolar we found lower values of total cover and herbaceous dicotyledonous cover at intermediate intensities of *** only negative relationship found was the cover of clonal and non-clonal shrubs,possibly explained by the greater use of these shrubs as firewood near *** summary,our study does not show important changes in Plant Functional Types as a function of grazing pressure in the studied grasslands probably because grazing pressure is diluted or diminished when livestock rotates in different areas and grazing durations ***,the long grazing history with which the Puna has evolved could also contribute to the co-structuration between native vegetation and livestock farming.

关键词： Natural grasslands Puna herbivory ecological perturbation

Plant community on a volcano mountaintop reveals unique high-altitude vegetation in southeastern Brazil

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Journal of Mountain science 2024年第9期21卷 3018-3030页

作者： Igor Musauer KEssOUs Ruy JoséValka alves Nílber gonçalves da sILVA Amilcar Walter sAPORETTI JUNIOR Biodiversity Laboratory Federal Institute of EducationScience and Technology of Southern Minas Gerais(IFSULDEMINAS)Av.Dirce Pereira Rosa300-Jardim Esperança37713-100Poços de CaldasMGBrazil Department of Botany National MuseumFederal University of Rio de JaneiroQuinta da Boa Vista s.n.São Cristóvão20949-040Rio de JaneiroRJBrazil Gothenburg Global Biodiversity Centre Carl Skottsbergs Gata 22BSE 41319GothenburgSweden

Mountains exhibit a high degree of endemism and diversity,however,quantifying their biodiversity can be *** to islands,species isolation in mountainous regions results in comparable patterns of evolution and extinction,rendering their biodiversity unique and highly susceptible to anthropogenic *** topographic relief in mountains plays a crucial role in creating habitat complexity,which in turn contribute to high plant ***,we investigated plant diversity in the volcano mountaintop vegetation on the Poços de Caldas Plateau,a region situated in the ecotone between the Atlantic Forest and Cerrado,characterized by natural radiation and significant anthropogenic *** employed an automated approach through the filtering of georeferenced and non-georeferenced data to obtain a list of plant species in the ***,we statistically investigated the similarity among different high-altitude vegetations belonging to the campos de altitude from the Atlantic Forest and campos rupestres from the *** plateau exhibits high plant diversity,including 1,659 specific and infraspecific taxa,especially belonging to Asteraceae and *** analyses suggest that geographical distance is a strong predictor of dissimilarity and that the Poços de Caldas Plateau is more floristically related to the campos rupestres,despite being associated with campos de *** region possesses a unique set of biodiversity,indicating that it may be a distinct ***,we hypothesize that Pleistocene events likely influenced the conformation of the current floristic composition in the region through species interchange between the Cerrado and Atlantic *** study also highlights the few taxa assessed for conservation status and anthropogenic threats that this habitat is facing.

关键词： Atlantic Forest Biogeography Cerrado Community ecology Grassland

Antecedent Precipitation Index to Estimate soil Moisture and Correlate as a Triggering Process in the Occurrence of Landslides

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International Journal of Geosciences 2024年第1期15卷 70-86页

作者： Marcio Augusto Ernesto De Moraes Walter Manoel mendes Filho Rodolfo Moreda mendes Cassiano Antonio Bortolozo Daniel Metodiev Marcio Roberto Magalhães De Andrade Harideva Marturano Egas tatiana s.s.el gonçalves mendes Luana Albertani Pampuch CEMADEN - National Centre for Monitoring and Early Warnings of Natural Disasters General Coordination of Research and Development S&#227o José dos Campos Brazil Faculty of science and Technology Goias Federal University Aparecida de Goi&#226nia Brazil Institute of science and Technology S&#227o Paulo State University (Unesp) S&#227o José dos Campos Brazil

Landslides are highly dangerous phenomena that occur in different parts of the world and pose significant threats to human populations. Intense rainfall events are the main triggering process for landslides in urbanized slope regions, especially those considered high-risk areas. Various other factors contribute to the process;thus, it is essential to analyze the causes of such incidents in all possible ways. soil moisture plays a critical role in the Earth’s surface-atmosphere interaction systems;hence, measurements and their estimations are crucial for understanding all processes involved in the water balance, especially those related to landslides. soil moisture can be estimated from in-situ measurements using different sensors and techniques, satellite remote sensing, hydrological modeling, and indicators to index moisture conditions. Antecedent soil moisture can significantly impact runoff for the same rainfall event in a watershed. The Antecedent Precipitation Index (API) or “retained rainfall,” along with the antecedent moisture condition from the Natural Resources Conservation service, is generally applied to estimate runoff in watersheds where data is limited or unavailable. This work aims to explore API in estimating soil moisture and establish thresholds based on landslide occurrences. The estimated soil moisture will be compared and calibrated using measurements obtained through multisensor capacitance probes installed in a high-risk area located in the mountainous region of Campos do Jordão municipality, são Paulo, Brazil. The API used in the calculation has been modified, where the recession coefficient depends on air temperature variability as well as the climatological mean temperature, which can be considered as losses in the water balance due to evapotranspiration. Once the API is calibrated, it will be used to extrapolate to the entire watershed and consequently estimate soil moisture. By utilizing recorded mass movements and comparing them with AP

关键词： Landslides Antecedent Precipitation Index soil Moisture Threshold Water Balance

A review on the scale-up of high-shear wet granulation processes and the impact of process parameters

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Particuology 2024年第9期92卷 180-195页

作者： Ana Rita alves Marta Filipe simões sérgio simões João Gomes University of Coimbra CERESDepartment of Chemical EngineeringFaculty of Sciences and TechnologyRua Sílvio Lima3030-790CoimbraPortugal Bluepharma-Indústria Farmacêutica São Martinho do BispoCoimbra3045-016Portugal Faculty of Pharmacy University of CoimbraAzinhaga de Santa Comba3000-548CoimbraPortugal

Wet granulation is one of the most important agglomeration processes,and high-shear granulation(HsG)one of the most employed technologies in the pharmaceutical *** most critical process parameters of HsG are discussed in this *** main concern in scaling up the wet granulation process is the differences between scales,which prevent the particles from having the same experience across all *** scale-up of wet granulation processes is commonly divided into two categories:engineering and attribute-based *** engineering-based scale-up approach is a strategy based on dimensional analysis and an attribute-based supported on the principles of“equifinality”,where process variables are adjusted to obtain equivalent granule *** work presents the effect of different HsG process parameters on the scale-up,as well as the use of process analytical tools(PAT)and modelling *** aim is to review applied scale-up approaches in HsG and discuss benefits and *** is proven why the scale-up for oral solid pharmaceutical products is still considered a hot topic and a very challenging task for development and engineering teams.

关键词： High-shear wetgranulation Parametric-based Attribute-based Physics-based modelling Impeller design scale-up

From prediction to prevention:Machine learning revolutionizes hepatocellular carcinoma recurrence monitoring

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World Journal of Gastroenterology 2024年第7期30卷 631-635页

作者： mariana Michelle Ramírez-Mejía Nahum Méndez-sánchez Plan of Combined studies in Medicine Faculty of MedicineNational Autonomous University of MexicoDistrito Federal 04510Mexico Liver Research Unit Medica Sur Clinic&FoundationDistrito Federal 14050Mexico Faculty of Medicine National Autonomous University of MexicoDistrito Federal 04510Mexico

In this editorial,we comment on the article by Zhang et al entitled Development of a machine learning-based model for predicting the risk of early postoperative recurrence of hepatocellular *** carcinoma(HCC),which is characterized by high incidence and mortality rates,remains a major global health challenge primarily due to the critical issue of postoperative *** recurrence,defined as recurrence that occurs within 2 years posttreatment,is linked to the hidden spread of the primary tumor and significantly impacts patient *** predictive factors,including both patient-and treatment-related factors,have limited predictive ability with respect to HCC *** integration of machine learning algorithms is fueled by the exponential growth of computational power and has revolutionized HCC *** study by Zhang et al demonstrated the use of a groundbreaking preoperative prediction model for early postoperative HCC *** persist,including sample size constraints,issues with handling data,and the need for further validation and *** study emphasizes the need for collaborative efforts,multicenter studies and comparative analyses to validate and refine the *** these challenges and exploring innovative approaches,such as multi-omics integration,will enhance personalized oncology *** study marks a significant stride toward precise,efficient,and personalized oncology practices,thus offering hope for improved patient outcomes in the field of HCC treatment.

关键词： Hepatocellular carcinoma Early recurrence Machine learning XGBoost model Predictive precision medicine Clinical utility Personalized interventions

A discussion about the limitations of the Eurocode’s high-speed load model for railway bridges

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Railway Engineering science 2024年第2期32卷 211-228页

作者： gonçalo ferreira Pedro Montenegro JoséRui Pinto António Abel Henriques Rui Calçada CONsTRUCT-LEsE Faculty of EngineeringUniversity of PortoRua Dr.Roberto Frias4200-465 PortoPortugal CONsTRUCT-LABEsT Faculty of EngineeringUniversity of PortoRua Dr.Roberto Frias4200-465 PortoPortugal

High-speed railway bridges are subjected to normative limitations concerning maximum permissible deck *** the design of these structures,the European norm EN 1991-2 introduces the high-speed load model(HsLM)—a set of point loads intended to include the effects of existing high-speed ***,the evolution of current trains and the recent development of new load models motivate a discussion regarding the limits of validity of the *** this study,a large number of randomly generated load models of articulated,conventional,and regular trains are tested and compared with the envelope of HsLM *** each type of train,two sets of 100,000 load models are considered:one abiding by the limits of the EN 1991-2 and another considering wider *** comparison is achieved using both a bridge-independent metric(train signatures)and dynamic analyses on a case study bridge(the Canelas bridge of the Portuguese Railway Network).For the latter,a methodology to decrease the computational cost of moving loads analysis is *** show that some theoretical load models constructed within the stipulated limits of the norm can lead to effects not covered by the *** is especially noted in conventional trains,where there is a relation with larger distances between centres of adjacent vehicle bogies.

关键词： High-speed load model Dynamic analysis High-speed railways Train signature Railway bridges Deck acceleration

Contribution of glial cells to the neuroprotective effects triggered by repetitive magnetic stimulation:a systematic review

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Neural Regeneration Research 2024年第1期19卷 116-123页

作者： susana A.ferreira Nuno Pinto Inês serrenho Maria Vaz Pato Graça Baltazar Centro de Investigação em Ciências da saúde(CICs-UBI) Universidade da Beira InteriorCovilhãPortugal Faculdade de Ciências da saúde Universidade da Beira InteriorCovilhãPortugal GRUBI-systematic Reviews Group University of Beira InteriorCovilhãPortugal

Repetitive transcranial magnetic stimulation has been increasingly studied in different neurological diseases,and although most studies focus on its effects on neuronal cells,the contribution of nonneuronal cells to the improvement trigge red by repetitive transcranial magnetic stimulation in these diseases has been increasingly *** systematically review the effects of repetitive magnetic stimulation on non-neuronal cells two online *** of science and PubMed were searched fo r the effects of high-frequency-repetitive transcranial magnetic stimulation,low-frequencyrepetitive transcranial magnetic stimulation,intermittent theta-bu rst stimulation,continuous thetaburst stimulation,or repetitive magnetic stimulation on non-neuronal cells in models of disease and in unlesioned animals or cells.A total of 52 studies were *** protocol more frequently used was high-frequency-repetitive magnetic stimulation,and in models of disease,most studies report that high-frequency-repetitive magnetic stimulation led to a decrease in astrocyte and mic roglial reactivity,a decrease in the release of pro-inflammatory cyto kines,and an increase of oligodendrocyte *** trend towards decreased microglial and astrocyte reactivity as well as increased oligodendrocyte proliferation occurred with intermittent theta-burst stimulation and continuous theta-burst *** papers analyzed the low-frequency-repetitive transcranial magnetic stimulation protocol,and the parameters evaluated were restricted to the study of astrocyte reactivity and release of pro-inflammatory cytokines,repo rting the absence of effects on these paramete *** what concerns the use of magnetic stimulation in unlesioned animals or cells,most articles on all four types of stimulation reported a lack of *** is also important to point out that the studies were developed mostly in male rodents,not evaluating possible diffe rential effects of repetitive transcranial magneti

关键词： astrocyte glia high-frequency repetitive magnetic stimulation inflammation low-frequency repetitive magnetic stimulation microglia neurologic disorders oligodendrocyte repetitive magnetic stimulation theta-burst stimulation

Large magnetocaloric effect and magnetic properties of EuRhO3

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Journal of Rare Earths 2024年第9期42卷 1724-1729页

作者： M.Lassri M.sajieddine A.elouafi A.el Hachmi s.el Ouahbi R.Moubah Laboratory of Energy and Materials Engineering (LGEM) University of Sultan Moulay SlimaneFaculty of Science and Technology (FST) Institute of Applied Physics (IAP)-school of Industrial Management (EMINEs) Mohammed Ⅵ Polytechnic University National school of Applied sciences (ENsA) University of Sultan Moulay Slimane Laboratory of Mechanics Production and Industrial Engineering (LMPGI)Higher School of Technology of Casablanca (ESTC)University of Hassan Ⅱ Casablanca Laboratory of Radiation on Matter and Instrumentation (LRMI) Faculty of Science and Technology (FST) SettatHassan Ⅰ University Laboatory of Physics of Advanced Materials and Thermic (LPMAT) Faculty of Science Ain Chock (FSAC)University of Hassan Ⅱ Casablanca

We report on the structural,magnetic,and magnetocaloric properties of *** oxidation states of Eu and Rh ions were studied using X-ray photoelectron spectroscopy（XPs）.It is found that the Eu ions are mainly in the divalent oxidation state while the Rh ions have+4 ***3powders are found to be antiferromagnetic with a second order magnetic transition at Neel temperature（TN=2.9 K）.Analysis of the magnetic susceptibility versus temperature data in terms of the Curie=Weiss law:(χ=C/（T-θW）) for T>TN,yields θW=-3.1 K and effective magne tic moment ■,which is close to the theoretical value ■.The magnetic entropy change(-ΔsM),was determined by em ploying the thermodynam ic Maxwell's *** μ0H=5 T and near TN,■ and relative cooling power（RCP） exhibit large values of 33.7 J/（kg·K） and 238 J/kg,*** large magnitude of-ΔsMand RCP show that the EuRhO3compound could be a potential candidate to be used in cryogenic magnetic refrigeration.

关键词： Cryogenic magnetic refrigeration Magnetic properties Magnetocaloric effect Rare earths X-ray photoelectron spectroscopy