Macroscopic Description Research Articles

Smoothness Harmonic: A Graph-Based Approach to Reveal Spatiotemporal Patterns of Cortical Dynamics in fMRI Data

Despite fMRI data being interpreted as time-varying graphs in graph analysis, there has been more emphasis on learning sophisticated node embeddings and complex graph structures rather than providing a macroscopic description of cortical dynamics. In this paper, I introduce the notion of smoothness harmonics to capture the slowly varying cortical dynamics in graph-based fMRI data in the form of spatiotemporal smoothness patterns. These smoothness harmonics are rooted in the eigendecomposition of graph Laplacians, which reveal how low-frequency-dominated fMRI signals propagate across the cortex and through time. We showcase their usage in a real fMRI dataset to differentiate the cortical dynamics of children and adults while also demonstrating their empirical merit over the static functional connectomes in inter-subject and between-group classification analyses.

Elucidating the adsorption mechanism of herbicide Diuron onto activated carbons via steric, energetic and thermodynamic investigations

The residues of the species Calophyllum inophyllum and Manihot esculenta were carbonized after impregnation with ZnCl2 to produce two different activated carbons (ACs). These adsorbents were subsequently used in the removal of the toxic herbicide Diuron. Both the produced adsorbents present functional groups characteristic of structures containing lignin and cellulose. These groups are positioned in amorphous and disorganized arrangements. The activation process formed a porous carbon exoskeleton with a surface area of 468 m2 g−1 (AC Calophyllum inophyllum) and 614 m2 g−1 (AC Manihot esculenta), respectively. Adsorption tests of herbicide Diuron are performed at different temperatures, indicating better performances for the adsorbent derived from Manihot esculenta (Qmax = 220 mg/g). A physical model derived from statistical physics, which assumes the formation of two layers of Diuron molecules on the ACs surface is successfully used to analyze the adsorption mechanism. The theoretical analysis of model parameters shows that the number of herbicide molecules captured per adsorption site increases with temperature for both the tested adsorbents, suggesting that an endothermic aggregation process occurs. The calculation of the adsorption energies confirms that Diuron adsorption on the surface of both the adsorbents is based on physical forces. Finally, three thermodynamic parameters are analyzed to attribute a new macroscopic description of the adsorption mechanism.

Distribution of silicification intervals throughout the Barra Velha and Itapema formations: Host rock controls and chronology of silica precipitation (Pre-Salt, Santos Basin, Brazil)

The Barra Velha and Itapema formations, Aptian, Santos Basin, constitute large hydrocarbon reservoirs, mainly in carbonate rocks. These rocks host up to centimeter-thick silica bodies with a variety of textures and geometries along different carbonate facies, suggesting syngenetic, diagenetic, and hydrothermal processes in their formation. The mineralogical and textural changes related to these processes can directly influence the porosity and permeability of the reservoir rocks, turning the study of the silicified intervals important in the exploration and production of these deposits. We present here a systematic macroscopic and microscopic description of the silica bodies and its distribution through the carbonate facies the of Barra Velha and Itapema formations from the Sapinhoá and Búzios fields. Data allow us to identify four geometric types of silica bodies: tabular, irregular, oval and disseminated, which are composed of chalcedony, microcrystalline and macrocrystalline quartz. Tabular, oval, and irregular silica bodies are cross-cutted by mechanical compaction structures such as vertical fractures, boudins and faults. In addition, these bodies include relicts of the host rock lamination, which in turn deflects around them. Thus, silica precipitation must have been penecontemporaneous or in the early stages of diagenesis, before the main mechanical compaction stage. These features were not observed in the disseminated silica type, in the contrary, this type involves and overlaps oval and irregular bodies, indicating that this silica precipitation probably occurred in latter stages in relation to other body types. The genesis of disseminated bodies can then be related to diagenetic or hydrothermal processes during diagenesis. Therefore, the geometry of silica bodies and their spatial distribution are influenced by the host carbonatic petrofabrics and the chronology of silica precipitation within the sedimentary to diagenetic evolution of the sedimentary package. Finally, we present a systematics that can be easily applied to recognize these silica types in other exploration fields of pre-salt interval. The results presented here have great potential to be applied in the research on pre-salt intervals from other Brazilian and African basins since the host carbonate rocks are very similar and favor the development of similar silicification processes and results.

Mathematical justification of a compressible bi-fluid system with different pressure laws: A semi-discrete approach and numerical illustrations

In this paper we obtain a one velocity macroscopic description of a mixture of two viscous compressible fluids by homogenization/averaging. The paper is written in two parts that can be read independently one of the other. In the first part, we propose two numerical schemes respectively for a two-fluid immiscible system, (i.e. two fluids separated by sharp interfaces) and for a bifluid mixture system (diffuse interface description via volume fractions). We present various simulations that suggest that the two systems of equations describe the same mixture at different scales and, as a consequence, that averaged velocity, density and pressure of the first model match with the respective velocity, density and pressure of the second model. In a second part, we show how to mathematically formalize the previous assertion via kinetic equations verified by the Young measures associated to oscillatory solutions of the model describing the finer scale.

Can the Clocks Tick Together Despite the Noise? Stochastic Simulations and Analysis

The suprachiasmatic nucleus (SCN), also known as the circadian master clock, consists of a large population of oscillator neurons. Together, these neurons produce a coherent signal that drives the body’s circadian rhythms. What properties of the cell-to-cell communication allow the synchronization of these neurons, despite a wide range of environmental challenges such as fluctuations in photoperiods? To answer that question, we present a mean-field description of globally coupled neurons modeled as Goodwin oscillators with standard Gaussian noise. Provided that the initial conditions of all neurons are independent and identically distributed, any finite number of neurons becomes independent and has the same probability distribution in the mean-field limit, a phenomenon called propagation of chaos. This probability distribution is a solution to a Vlasov–Fokker–Planck type equation, which can be obtained from the stochastic particle model. We study, using the macroscopic description, how the interaction between external noise and intercellular coupling affects the dynamics of the collective rhythm, and we provide a numerical description of the bifurcations resulting from the noise-induced transitions. Our numerical simulations show a noise-induced rhythm generation at low noise intensities, while the SCN clock is arrhythmic in the high noise setting. Notably, coupling induces resonance-like behavior at low noise intensities, and varying coupling strength can cause period locking and variance dissipation even in the presence of noise.

Lung pathology of natural Babesia rossi infection in dogs.

A proportion of Babesia rossi infections in dogs are classified as complicated and one of the most lethal complications is acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). Most dogs that die succumb within 24 hours of presentation. The pulmonary pathology caused by B. rossi in dogs has not been described. The aim of this study was to provide a thorough macroscopic, histological and immunohistochemical description of the lung changes seen in dogs naturally infected with B. rossi that succumbed to the infection. Death was invariably accompanied by alveolar oedema. Histopathology showed acute interstitial pneumonia characterised by alveolar oedema and haemorrhages, with increased numbers of mononuclear leucocytes in alveolar walls and lumens. Intra-alveolar polymerised fibrin aggregates were observed in just over half the infected cases. Immunohistochemistry showed increased numbers of MAC387- and CD204-reactive monocyte-macrophages in alveolar walls and lumens, and increased CD3-reactive T-lymphocytes in alveolar walls, compared with controls. These histological features overlap to some extent (but far from perfectly) with the histological pattern of lung injury referred to as the exudative stage of diffuse alveolar damage (DAD) as is quite commonly reported in ALI/ARDS.

A Neural Network Approach for Homogenization of Multiscale Problems

We propose a neural network-based approach to the homogenization of multiscale problems. The proposed method uses a derivative-free formulation of a training loss, which incorporates Brownian walkers to find the macroscopic description of a multiscale PDE solution. Compared with other network-based approaches for multiscale problems, the proposed method is free from the design of hand-crafted neural network architecture and the cell problem to calculate the homogenization coefficient. The exploration neighborhood of the Brownian walkers affects the overall learning trajectory. We determine the bounds of micro- and macro-time steps that capture the local heterogeneous and global homogeneous solution behaviors, respectively, through a neural network. The bounds imply that the computational cost of the proposed method is independent of the microscale periodic structure for the standard periodic problems. We validate the efficiency and robustness of the proposed method through a suite of linear and nonlinear multiscale problems with periodic and random field coefficients.

New insight into the morphological characteristics of patella cubiti.

Accessory bones in the elbow region are rare anatomical variations with important clinical significance as they can be misdiagnosed as pathological lesions. Usually, they are asymptomatic and found incidentally during X-ray examination in the context of trauma. Although these bones have been previously described, their development is not fully understood. The present case provides complex macroscopic, X-ray and histological descriptions of a sesamoid bone in the posterior region of the elbow-patella cubiti and the related surrounding structures. Moreover, this report indicates the presence of a well-defined syndesmosis between patella cubiti and the proximal ulna.

Physics-based adaptivity of a spectral method for the Vlasov–Poisson equations based on the asymmetrically-weighted Hermite expansion in velocity space

We propose a spectral method for the 1D-1V Vlasov–Poisson system where the discretization in velocity space is based on asymmetrically-weighted Hermite functions, dynamically adapted via a scaling α and shifting u of the velocity variable. Specifically, at each time instant an adaptivity criterion selects new values of α and u based on the numerical solution of the discrete Vlasov–Poisson system obtained at that time step. Once the new values of the Hermite parameters α and u are fixed, the Hermite expansion is updated and the discrete system is further evolved for the next time step. The procedure is applied iteratively over the desired temporal interval. The key aspects of the adaptive algorithm are: the map between approximation spaces associated with different values of the Hermite parameters that preserves total mass, momentum and energy; and the adaptivity criterion to update α and u based on physics considerations relating the Hermite parameters to the average velocity and temperature of each plasma species. For the discretization of the spatial coordinate, we rely on Fourier functions and use the implicit midpoint rule for time stepping. The resulting numerical method possesses intrinsically the property of fluid-kinetic coupling, where the low-order terms of the expansion are akin to the fluid moments of a macroscopic description of the plasma, while kinetic physics is retained by adding more spectral terms. Moreover, the scheme features conservation of total mass, momentum and energy associated in the discrete, for periodic boundary conditions. A set of numerical experiments confirms that the adaptive method outperforms the non-adaptive one in terms of accuracy and stability of the numerical solution.

Hodophilus pseudoglabripes (Clavariaceae, Agaricales), a new species from Thailand

Hodophilus pseudoglabripes, a new species with a strong earthy odor, was found in forests dominated by Castanopsis (Fagaceae) in northern Thailand. This species is introduced with microscopic and macroscopic descriptions and colour photographs. Phylogenetic affinities were determined based on a combination of internal transcribed spacers (ITS) and large subunit (nrLSU) of the nuclear ribosomal DNA (rDNA). The new species was placed in Hodophilus, within an independent clade comprising the other two species from Asia, H. glabripes and H. indicus. This is the first report of the genus Hodophilus in Thailand. An updated key to all members of the genus Hodophilus is also provided.

Carl Weigert's pioneer definition of heart infarction as myocardial, coagulative necrosis due to obstruction of atherosclerotic coronary arteries in 1880, overshadowed by subsequent, secondary publications in the field.

In 1880, a German Jewish Professor of Pathology, Carl Weigert (1845-1904) first defined heart infarction as myocardial, coagulative necrosis ("Coagulationsnekrose") due to obliteration of atherosclerotic coronary arteries thanks, at least, partially to his great diligence in vascular staining methods. Histochemical techniques made his name eponymic as Weigert's Hematoxylin or Weigert's and Van Gieson's elastic stains are still used in routine practice to visualize, e.g., the framework of vessels. However, his discovery has been overshadowed by far more frequently cited in recent decades, subsequent but secondary, 214-page-long book dated on 1896 and titled "L'infarctus du myocarde et ses conséquences - ruptures, plaques fibreuses, anévrismes du coeur", in which René Marie repeated Carl Weigert's words that dead cardiomyocytes lost their cellular nuclei. Weigert introduced the term "die Infarcte des Herzmuskels", in 1880, in his paper titled "Über die pathologischen Gerinnungsvorgänge", in Virchows Archiv. According to Weigert, occlusions were caused by white thrombi ("weissen Thromben") on the ground of atheromatous changes of the coronary arteries. In following manner, he gave macroscopic description of heart infarction: "If a blood supply is very roughly (German: brüsk), completely cut off in individual parts of the heart muscle, yellowish dry masses are formed that resemble coagulated fibrin". "If examined microscopically, one usually does not find any fibrinous material exudate, but often a delusively normal tissue (sometimes you can even see cross striation of the muscle fibers): but all muscle fibers (...) are anucleate". Paradoxically, coronary thrombosis was also a cause of Carl Weigert's death.

Macroscopic and histological aspects of the pharynx and larynx of the giant anteater (Myrmecophaga tridactyla Linnaeus, 1758).

Giant anteater (Myrmecophaga tridactyla) is an endangered species that resides in much of Latin America, but it has been losing its habitat, especially in the Cerrado biome, where it constantly suffers traumas resulting from fires and roadkill. The anatomical knowledge of structures of the respiratory system is important for a better morphophysiological understanding of the species. Thus, this study aimed to perform the macroscopic and histomorphological description of the pharynx and larynx of the giant anteater. Twelve adult giant anteaters were used, three of them fixed in buffered formalin for further dissection and pharynx and larynx macroscopic analysis of structures. From the other animals, samples of the pharynx and larynx were collected and prepared for histological evaluation under optical microscope. Macroscopically, their pharynx and soft palate are extensive, and the anatomical location of these structures and the larynx differs greatly from that described in other species. The larynx, although more caudal, was similar to that of other animals. Histologically, the epithelium of these regions varied between the pseudostratified ciliated columnar and the non-keratinized stratified squamous epithelium. Laryngeal cartilages were composed of elastic (epiglotti) and hyaline cartilages (arytenoid, cricoid and thyroid cartilage), with an ossification process and glandular clusters around the hyaline cartilage. The distinct anatomical location of the pharynx and larynx of Myrmecophaga tridactyla is the main macroscopic finding of this study, besides the length of the pharynx and soft palate of these animals.

Coal Structure Prediction Based on Type-2 Fuzzy Inference System for Multi-Attribute Fusion: A Case Study in South Hengling Block, Qinshui Basin, China

The accurate prediction of coal structure is important to guide the exploration and development of coal reservoirs. Most prediction models are interpreted for a single sensitive coal seam, and the selection of sensitive parameters is correlated with the coal structure, but they ignore the interactions between different attributes. Part of it introduces the concept of the geological strength index (GSI) of coal rocks in order to achieve a multi-element macroscopic description and quantitative characterization of coal structure; however, the determination of coal structure involves some uncertainties among the properties of coal, such as lithology, gas content and tectonic fracture, due to their complex nature. Fuzzy inference systems provide a knowledge discovery process to handle uncertainty. The study shows that a type-2 fuzzy inference system (T2-FIS) with multi-attribute fusion is used to effectively fuse pre-stack and post-stack seismic inversion reservoir parameters and azimuthal seismic attribute parameters in order to produce more accurate prediction results for the Hengling block in the Shanxi area. The fuzzy set rules generated in this paper can provide a more reliable prediction of coal structure in the GSI system. The proposed system has been tested on various datasets and the results show that it is capable of providing reliable and high-quality coal structure predictions.

Bound states in the continuum induced by the strong coupling within the plasmonic lattices

Bound states in the continuum (BICs), manifesting themselves as the collapse of Fano resonance, are observed in many photonic and plasmonic systems. The BICs have been studied systematically through various methods such as the topological photonics analysis, temporal coupled mode theory, multipole decomposition method, and the cavity quantum electrodynamics (CQED) method. Since CQED can give a macroscopic and intrinsic description of light–matter interaction, it is expected to study BIC that participates in strong coupling. What is more, the relation between coupling strength, the Fano parameter, and the asymmetry property of BICs needs to be clarified. In this paper, we investigated the strong coupling between the cavity mode and Bloch-surface plasmon polariton (Bloch-SPP) mode induced by BICs within the plasmonic lattices of the metal-dielectric-metal (MDM) layer. The properties of strong coupling and BIC were revealed theoretically by the quantum model based on the CQED. The increase in the Fano parameters of BICs was proved to facilitate the coupling strength, which was indicated by the monotonically increasing relation between the Fano parameter and the coupling strength. This work may pave the way for flexible modulation and application of BIC in the fields of high-quality plasmonic nanocavity, low-threshold nano-lasers, and quantum information.

Grain Boundary Plane Measurement Using Transmission Electron Microscopy Automated Crystallographic Orientation Mapping for Atom Probe Tomography Specimens.

Grain boundaries are critical in determining the properties of materials, including mechanical stability, conductivity, and corrosion resistance. The specific properties of materials depend not only on the misorientation of the crystals, the three most commonly characterized parameters, but also on the angle of the grain boundary plane between the two crystals, the final two parameters in the five-parameter macroscopic description of the grain boundary. The method presented here allows for the direct measurement of all five parameters of the grain boundary in a transmission electron microscopy specimen of various morphologies. This is especially applicable to atom probe specimens, where only a single-tilt axis is generally available, allowing the crystallographic description to be matched to the detailed chemical data available in the atom probe tomography. This method provides a platform for efficient grain boundary analysis in unique samples, saving operator time and allowing for ease of acquisition and interpretation in comparison with traditional electron diffraction methods.

Gravitational matter creation, multi-fluid cosmology and kinetic theory

A macroscopic and kinetic relativistic description for a decoupled multi-fluid cosmology endowed with gravitationally induced particle production of all components is proposed. The temperature law for each decoupled particle species is also kinetically derived. The present approach points to the possibility of an exact (semi-classical) quantum-gravitational kinetic treatment by incorporating back reaction effects for an arbitrary set of dominant decoupled components. As an illustration we show that a cosmology driven by creation of cold dark matter and baryons (without dark energy) evolves like Lambda CDM. However, the complete physical emulation is broken when photon creation is added to the mixture thereby pointing to a crucial test in the future. The present analysis also open up a new window to investigate the Supernova-CMB tension on the values of H_0, as well as the S_8 tension since creation of all components changes slightly the CMB results and the expansion history both at early and late times. Finally, it is also argued that cross-correlations between CMB temperature maps and the Sunyaev–Zeldovich effect may provide a crucial and accurate test confronting extended CCDM and Lambda CDM models.

Production Technologies and Provenance of Ceramic Materials from the Earliest Foundry of Pre-Roman Padua, NE Italy

The earliest foundry site of Pre-Roman Padua, in the Veneto region (north-eastern Italy), provided evidence of craft activities and residential areas dated between the end of the 9th and 1st centuries BCE. Common and fine wares were found, most of them belonging to two main ceramic classes: (i) highly dark-colored bodies with silicate inclusions; (ii) carbonate-tempered pots. Macroscopic and petrographic (POM) descriptions and spectroscopy—mineralogical (XRPD) and geochemical (XRF)—analyses were carried out to define the provenance and technological choices (production recipes and firing conditions). The first ceramic class comprised diverse local/regional productions made with a common geo-resource, consisting in quartz-rich illitic clays, for which pit firing conditions generally under 850–900 °C were adopted. The purification of the starting base clays, the tempering of the clayey pastes with silica-rich grains and/or the polishing of surfaces were accomplished for fine wares. The carbonate-tempered pottery probably corresponded to an allochthonous ceramic class that might be used in the trade of specific contents. As such pots were made out of different illitic clays and under different redox conditions, they might correspond to diverse productions. The adoption of precise choices in very specific wares, not belonging to any of these two main ceramic classes, suggests the trade of fine wares in the Veneto during the First Iron Age.

Research on FPGA Functional Reliability based on Petri Net

Engineering reliability ground verification for space FPGA devices is one of the important aspects of space load digital system design. At present, there are three methods: code correctness verification, system functional test, and formal verification. Based on the Petri Net theory, this paper proposes a macroscopic and accurate description of the functional characteristics of FPGA engineering with the functional module as the granularity and the control variable as the core. On this basis, combined with the state-reachability graph theory, functional execution reliability is proposed. This evaluation method evaluates the degree of influence of the core control data error on the execution of the system function in a workflow and provides a new basis for the improvement of the protection method and the evaluation of the protective effect.

Tangential Impedance

The problem of reflection of a plane sound wave from a rigid surface covered with dipole resonators is solved. It is shown that such a surface responds to obliquely incident waves, while the found angular dependence of the reflection coefficient cannot be obtained for surfaces whose properties are described by conventional impedance. Therefore, the concept of tangential impedance is proposed: the ratio of tangential acoustic force on a surface to its normal velocity. It is shown that the tangential impedance can be both isotropic and anisotropic; i.e., the magnitude of the latter depends on the direction of the incident wave. It is proposed to call the corresponding surfaces unpolarized and polarized. In some cases, tangential impedance can be useful for macroscopic description of complex metasurfaces.

Towards predicting shear-banding instabilities in lipid monolayers

Langmuir monolayers are advantageous systems used to investigate how lipid membranes get involved in the physiology of many living structures, such as collapse phenomena in alveolar structures. Much work focuses on characterizing the pressure-bearing capacity of Langmuir films, expressed in the form of isotherm curves. These show that monolayers experience different phases during compression with an according evolution of their mechanical response, incurring into instability events when a critical stress threshold is overcome. Although well-known state equations, which establish an inverse relationship between surface pressure and area change, are able to properly describe monolayer behaviour during liquid expanded phase, the modelling of their nonlinear behaviour in the subsequent condensed region is still an open issue. In this regard, most efforts are addressed to explain out-of-plane collapse by modelling buckling and wrinkling mainly resorting to linearly elastic plate theory. However, some experiments on Langmuir monolayers also show in-plane instability phenomena leading to the formation of the so-called shear bands and, to date, no theoretical description of the onset of shear banding bifurcation in monolayers has been yet provided. For this reason, by adopting a macroscopic description, we here study material stability of the lipid monolayers and exploit an incremental approach to find the conditions that kindle shear bands. In particular, by starting from the widely assumed hypothesis that monolayers behave elastically in the solid-like region, in this work a hyperfoam hyperelastic potential is introduced as a new constitutive strategy to trace back the nonlinear response of monolayer response during densification. In this way, the obtained mechanical properties together with the adopted strain energy are successfully employed to reproduce the onset of shear banding exhibited by some lipid systems under different chemical and thermal conditions.