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The INTERNODES Method for Non-conforming Discretizations of PDEs

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Communications on Applied Mathematics and Computation 2019年第3期1卷 361-401页

作者： paola Gervasio Alfio Quarteroni DICATAM University degli Studi di BresciaBresciaItaly MOX Department of MathematicsPolitecnico di MilanoMilanItaly Institute of Mathematics Ecole Polytechnique F6d6rale de Lausanne (EPFL)LausanneSwitzerland

INTERNODES is a general purpose method to deal with non-conforming discretizations of partial differential equations on 2D and 3D regions partitioned into two or several disjoint subdomains. It exploits two intergrid interpolation operators, one for transfering the Dirichlet trace across the interfaces, and the other for the Neumann trace. In this paper, in every subdomain the original problem is discretized by either the finite element method (FEM) or the spectral element method (SEM or hp-FEM), using a priori non-matching grids and piecewise polynomials of different degrees. Other discretization methods, however, can be used. INTERNODES can also be applied to heterogeneous or multiphysics problems, that is, problems that feature different differential operators inside adjacent subdomains. For instance, in this paper we apply the INTERNODES method to a Stokes- Darcy coupled problem that models the filtration of fluids in porous media. Our results highlight the flexibility of the method as well as its optimal rate of convergence with respect to the grid size and the polynomial degree.

关键词： Domain decomposition Non-conforming approximation Non-conforming grids Interpolation Finite element method hp-finite element method Spectral element method

Microenvironment promotes cytoskeleton remodeling and adaptive phenotypic transition

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BIOCELL 2022年第6期46卷 1357-1362页

作者： MARIANO BIZZARRI paola PONTECORVI Department of Experimental Medicine Systems Biology GroupSapienza University of RomeRome00163Italy

The cytoskeleton includes three main classes of networked filaments behaving as a coherent and complex structure that confers stability to cell shape while serving as sensor of internal/extracellular *** stimuli interfere with the non-linear dynamics that govern cytoskeleton architecture,namely by fostering symmetry breakings and transitions across different phenotypic *** process induces a wholecoherent adaptive response,involving the reprogramming of biochemical and gene-expression *** characteristics are especially relevant during development,and in those conditions in which a deregulated crosstalk between cells and the stroma is at the core of the pathological ***,studying how the cytoskeleton can be modified–both pharmacologically and/or through microenvironment-dependent changes–has become a major area of interest in cancer and developmental biology.

关键词： Cell scaffolding environmental cues non-equilibrium thermodynamics phenotypic reversion cell fate commitment

Multifaceted Bioinspiration for Improving the Shaft Resistance of Deep Foundations

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Journal of Bionic Engineering 2020年第5期17卷 1059-1074页

作者： Seyed Ali Aleali paola Bandini Craig Michael Newtson Center for Bio-mediated and Bio-inspired Geotechnics Department of Civil EngineeringNew Mexico State UniversityLas CrucesNew Mexico 88003-8001USA

This paper describes the bioinspiration process to derive design concepts for new deep foundation systems that have greater axial capacity per unit volume of pile material compared to conventional deep *** study led to bioinspired ideas that provide greater load capacity by increasing the pile shaft *** bioinspiration approach used problem-solving strategies to define the problem and transfer strategies from biology to geotechnical *** bioinspiration considered the load transfer mechanism of hydroskeletons and the anchorage of the earthworm,razor clam,kelp,and lateral roots of *** biostrategies that were transferred to the engineering domain included a flexible but incompressible core,passive behaviour against external loading,a longitudinally split shell that allows expansion for anchorage,and lateral root-type or setae-type anchoring *** concepts of three bioinspired deep foundation systems were proposed and *** advantage of this approach was illustrated with two examples of the new laterally expansive pile in drained sand under axial *** finite element analysis of these examples showed that the new laterally expansive pile can provide considerably greater load capacity compared to a conventional cylindrical pile due to the increased lateral confining pressure developed along the expanded pile core.

关键词： bioinspiration expansion anchorage deep foundation pile capacity frictional resistance

Synthesis, Properties and Potential Applications of Porous Graphene: A Review

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Nano-Micro Letters 2013年第4期5卷 260-273页

作者： paola Russo Anming Hu Giuseppe Compagnini Department of Mechanical and Mechatronics Engineering University of Waterloo Dipartimento di Scienze Chimiche Università degli Studi di Catania Institute of Laser Technology Beijing University of Technology

Since the discovery of graphene, many efforts have been done to modify the graphene structure for integrating this novel material to nanoelectronics, fuel cells, energy storage devices and in many other applications. This leads to the production of different types of graphene-based materials, which possess properties different from those of pure graphene. Porous graphene is an example of this type of materials. It can be considered as a graphene sheet with some holes/pores within the atomic plane. Due to its spongy structure, porous graphene can have potential applications as membranes for molecular sieving, energy storage components and in nanoelectronics. In this review, we present the recent progress in the synthesis of porous graphene. The properties and the potential applications of this new material are also discussed.

关键词： Graphene Porous graphene Gas separation Energy storage

Gradient descent decomposition of force-field motor primitives optogenetically elicited for motor mapping of the murine lumbosacral spinal cord

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Zoological Research 2023年第3期44卷 604-619页

作者： paola Salmas Vincent C.K Cheung School of Biomedical Sciences and Gerald Choa Neuroscience InstituteThe Chinese University of Hong KongHong Kong SARChina Kunming Institute of Zoology-The Chinese University of Hong Kong(KIZ-CUHK)Joint Laboratory of Bioresources and Molecular Research of Common Diseases Hong Kong SARChina

Generating diverse motor behaviors critical for survival is a challenge that confronts the central nervous system(CNS)of all *** movement execution,the CNS performs complex calculations to control a large number of neuromusculoskeletal *** theory of modular motor control proposes that spinal interneurons are organized in discrete modules that can be linearly combined to generate a variety of behavioral *** modules have been previously represented as stimulus-evoked force fields(FFs)comprising isometric limb-endpoint forces across workspace ***,we ask whether FFs elicited by different stimulations indeed represent the most elementary units of motor control or are themselves the combination of a limited number of even more fundamental motor *** probe for potentially more elementary modules,we optogenetically stimulated the lumbosacral spinal cord of intact and spinalized Thy1-ChR2 transgenic mice(n=21),eliciting FFs from as many single stimulation loci as possible(20-70 loci per mouse)at minimally necessary *** found that the resulting varieties of FFs defied simple categorization with just a few *** used gradient descent to further decompose the FFs into their underlying basic force fields(BFFs),whose linear combination explained FF *** mice,we identified 4-5 BFFs with partially localizable but overlapping representations along the spinal *** BFFs were structured and topographically distributed in such a way that a rostral-to-caudal traveling wave of activity across the lumbosacral spinal cord may generate a swing-to-stance gait *** BFFs may represent more rudimentary submodules that can be flexibly merged to produce a library of motor modules for building different motor behaviors.

关键词： Motor mapping Optogenetics Spinal cord Motor primitives Traveling wave

Evidence of associative blocking during foraging in the social wasp Vespula germanica

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Insect Science 2021年第4期28卷 1103-1108页

作者： Sabrina Moreyra paola D'Adamo Mariana Lozada Laboratorio Ecotono Instituto de Investigaciones en Biodiversidad y Medio Ambiente(INIBIOMA)-CONICET-Universidad Nacional del Comahue(CRUB)BarilocheArgentina

While foraging,Vespula germanica usually return to abundant food *** this relocation behavior,these wasps learn to identify contextual cues associated with food *** analyzed associative blocking in this species,that is,how an association with a conditioned stimulus(CS1)blocks subsequent learning when a novel stimulus(CS2)is added on a second foraging *** groups of wasps(A,B,and C;total 74 individual wasps)were observed while collecting meat during one or two consecutive *** group A,an environmental cue(CS1)was paired with food placed at a specific site,and on the second visit,a second cue(CS2)was added while food remained in the same *** a subsequent testing phase,CS1 was removed and the food source displaced *** then recorded the number of hovers performed over the empty dish(previously baited).Group A wasps appeared to ignore the addition of CS2 on their second visit because they performed fewer hovers over the learned *** group A,the duration of the decision-making process to finally fly toward the baited dish was shorter than when CS1 and CS2 were presented together on their first visit(group B).This is the first study to demonstrate the occurrence of associative blocking in vespids,confirming that a prior foraging experience influences subsequent food relocation in *** findings reveal that first learning episodes block further associations with novel contextual cues,contributing to understanding of complex cognitive processes involved in ***´s foraging behavior.

关键词： associative blocking foraging behavior learning prior experience social wasps

Diagnosis of Physical and Biological Control over Phytoplankton in the Gulf of Maine-Georges Bank Region Using an Adjoint Data Assimilation Approach

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Journal of Ocean University of China 2014年第3期13卷 356-368页

作者： WANG Caixia paola Malanotte-Rizzoli Physical Oceanography Laboratory Ocean University of China Department of Earth Atmospheric and Planetary Sciences Massachusetts Institute of Technology

The linkage between physical and biological processes, particularly the effect of the circulation field on the distribution of phytoplankton, is studied by applying a two-dimensional model and an adjoint data assimilation approach to the Gulf of Maine-Georges Bank region. The model results, comparing well with observation data, reveal seasonal and geographic variations of phytoplankton concentration and verify that the seasonal cycles of phytoplankton are controlled by both biological sources and advection processes which are functions of space and time and counterbalance each other. Although advective flux divergences have greater magnitudes on Georges Bank than in the coastal region of the western Gulf of Maine, advection control over phytoplankton concentration is more significant in the coastal region of the western Gulf of Maine. The model results also suggest that the two separated populations in the coastal regions of the western Gulf of Maine and on Georges Bank are self-sustaining.

关键词： physical circulation biological source adjoint data assimilation

Diagnosis of Physical and Biological Controls on Phytoplankton Distribution in the Sargasso Sea

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Journal of Ocean University of China 2014年第1期13卷 32-44页

作者： WANG Caixia paola Malanotte-Rizzoli Physical Oceanography Laboratory Ocean University of China Department of Earth Atmospheric and Planetary Sciences Massachusetts Institute of Technology

The linkage between physical and biological processes is studied by applying a one-dimensional physical-biological coupled model to the Sargasso Sea. The physical model is the Princeton Ocean Model and the biological model is a five-component system including phytoplankton, zooplankton, nitrate, ammonium, and detritus. The coupling between the physical and biological model is accomplished through vertical mixing which is parameterized by the level 2.5 Mellor and Yamada turbulence closure scheme. The coupled model investigates the annual cycle of ecosystem production and the response to external forcing, such as heat flux, wind stress, and surface salinity, and the relative importance of physical processes in affecting the ecosystem. Sensitivity experiments are also carried out, which provide information on how the model bio-chemical parameters affect the biological system. The computed seasonal cycles compare reasonably well with the observations of the Bermuda Atlantic Time-series Study(BATS). The spring bloom of phytoplankton occurs in March and April, right after the weakening of the winter mixing and before the establishment of the summer stratification. The bloom of zooplankton occurs about two weeks after the bloom of phytoplankton. The sensitivity experiments show that zooplankton is more sensitive to the variations of biochemical parameters than phytoplankton.

关键词： physical-biological coupled model annual cycle external forcing bio-chemical parameter

Endoluminal vacuum-assisted therapy to treat rectal anastomotic leakage:A critical analysis

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World Journal of Gastroenterology 2022年第14期28卷 1394-1404页

作者： Andrea Vignali paola De Nardi Department of Gastrointestinal Surgery IRCCS San Raffaele Scientific InstituteMilano 20132Italy Department of Surgery Vita-Salute UniversityMilano 20132Italy

Endoluminal vacuum-assisted therapy(EVT)has been introduced recently to treat colorectal anastomotic leaks in clinically stable non-peritonitic *** application has been mainly reserved to low colorectal and colo-anal *** main advantage of this new procedure is to ensure continuous drainage of the abscess cavity,to promote and to accelerate the formation of granulation tissue resulting in a reduction of the abscess *** reported results are promising allowing a higher preservation of the anastomosis when compared to conventional treatments that include trans-anastomotic tube placement,percutaneous drainage,endoscopic clipping of the anastomotic defect or stent ***,despite this procedure is gaining acceptance among the surgical community,indications,inclusion criteria and definitions of success are not yet standardized and extremely heterogeneous,making it difficult to reach definitive conclusions and to ascertain which are the real benefits of this new ***,long-term and functional results are poorly *** present review is focused on critically analyzing the theoretical benefits and risks of the procedure,short-and long-term functional results and future direction in the application of EVT.

关键词： Anastomotic leakage Rectal surgery Endoluminal vacuum therapy Endosponge Complications