Macroscopic Regions Research Articles

Thin-film evaporation in microchannels: A combined analytical and computational fluid dynamics approach to assessing meniscus curvature impact

Computational fluid dynamics (CFD) is employed to investigate the effects of variation in bulk meniscus curvature on evaporative heat and mass transfer in microchannels. Evaporation in microchannels presents a classic multiscale problem, encompassing both microscopic and macroscopic length scales in the thin-film and bulk meniscus regions, respectively. Therefore, the liquid-vapor interface or meniscus shape is first determined through thin-film evaporation analysis using numerical approaches found in the literature. However, a new approach for establishing boundary conditions is also proposed, allowing for the representation of varying curvatures within the bulk meniscus region. Then, the obtained meniscus thickness profiles are exported to a two-dimensional CFD framework. The primary advantage of this developed CFD framework lies in its capability to simultaneously analyze evaporative heat and mass transfer from both microscopic and macroscopic regions, a feature that enhances research endeavors concerning micro and miniature heat pipes. The developed model is applied to various rectangular microchannel sizes, ranging from 10 to 100 μm in width, with wall superheats varying from 0.1 to 3.0 K. The aim is to quantify the effects of variations in bulk meniscus curvature on the evaporative characteristics of the extended meniscus (comprising both thin-film and bulk meniscus regions), using the concept of thermal resistance. Consequently, based on the CFD simulation results, multiple regression analysis is employed to formulate the total thermal resistance in terms of independent parameters, namely the microchannel width, wall superheat, and the radius of curvature (Rc). It is observed that the radius of curvature has a marginal impact on the total thermal resistance, allowing its influence to be expressed by a power-law function of (Rc/Rm)0.102, where Rm represents the minimum radius of curvature.

Global disparities in CO2 emissions from mobility sectors of diverse economies: A macroscopic exploration across 188 countries/regions

Reducing CO2 emissions represents a global challenge, and the mobility sectors account for a considerable portion of total emissions, with marked disparities across diverse economies. Viewed from a macroscopic perspective, countries and regions around the world can be categorized in various ways. However, relying on a single or a few indicators often proves inadequate to meet the classification requirements for carbon reduction and sustainable development. In this study, employing machine learning and guided by 10 economic indicators, we classified 188 countries/regions into 6 identifiable clusters. Subsequently, by applying ratio analysis and random forest methodologies, we conducted a matrix-based analysis that elucidates the distinct emission characteristics of each mobility sector. Feature importance analysis revealed that for highly developed economies, the total population's contribution was significant, especially in domestic and international aviation, accounting for 50% and 25% of emissions, respectively. In contrast, for lower-middle-income countries and regions, while the total population still played a pivotal role, its influence was most pronounced in railway transportation, reaching 67%. For rapidly developing economies, domestic aviation emissions reached a peak influence of 61%. These insights emphasize the necessity for strategies tailored to the unique attributes of economic entities.

Genetic and immune determinants of E. coli liver abscess formation.

Systemic infections can yield distinct outcomes in different tissues. In mice, intravenous inoculation of Escherichia coli leads to bacterial replication within liver abscesses, while other organs such as the spleen clear the pathogen. Abscesses are macroscopic necrotic regions that comprise the vast majority of the bacterial burden in the animal, yet little is known about the processes underlying their formation. Here, we characterize E. coli liver abscesses and identify host determinants of abscess susceptibility. Spatial transcriptomics revealed that liver abscesses are associated with heterogenous immune cell clusters comprised of macrophages, neutrophils, dendritic cells, innate lymphoid cells, and T-cells that surround necrotic regions of the liver. Abscess susceptibility is heightened in the C57BL lineage, particularly in C57BL/6N females. Backcross analyses demonstrated that abscess susceptibility is a polygenic trait inherited in a sex-dependent manner without direct linkage to sex chromosomes. As early as 1 d post infection, the magnitude of E. coli replication in the liver distinguishes abscess-susceptible and abscess-resistant strains of mice, suggesting that the immune pathways that regulate abscess formation are induced within hours. We characterized the early hepatic response with single-cell RNA sequencing and found that mice with reduced activation of early inflammatory responses, such as those lacking the LPS receptor TLR4 (Toll-like receptor 4), are resistant to abscess formation. Experiments with barcoded E. coli revealed that TLR4 mediates a tradeoff between abscess formation and bacterial clearance. Together, our findings define hallmarks of E. coli liver abscess formation and suggest that hyperactivation of the hepatic innate immune response drives liver abscess susceptibility.

Quadrupole higher-order topological phases in static mechanical metamaterials

Higher-order topological insulators (HOTIs), an extended concept of traditional first-order topological insulators, are capable of hosting multidimensional topological states and provide an unprecedented platform for robust wave manipulation and energy enhancement. HOTIs have recently been extended to mechanical systems. However, most studies focus primarily on dynamic wave motion and signal transmission. In this paper, we show a realization of quadrupole HOTIs using static Rayleigh deformation modes in three-dimensional layered mechanical metamaterials. The quadrupole topological phase, usually shown in dynamic systems as charge accumulation or energy concentration at corners, is present in the mechanical metamaterial through its patterned static deformation. It is demonstrated analytically that for the topologically protected corner modes, an externally applied corner point load can be fully confined within a localized region for any layer, thereby constructing a deformation isolation device capable of facilitating deformation shielding for a macroscopic bulk region. The obtained results shed light on the exploration of higher-order topological states with a static system and the control of bulk and boundary static deformations in various dimensions.

Neural mass framework for decoding amyloid and Tau impact on neuronal activity under Alzheimer’s Disease

AbstractBackgroundWe introduce a computational brain network model to understand the effect of abnormal microscopical processes into non‐invasive macroscopic neuronal activity observations and cognitive impairment across the Alzheimer’s disease (AD) spectrum. Amyloid‐beta (Aβ) plaques and tau protein aggregates (τ) modulate neuronal firing with the former likely increasing firing (hyperactivity) and the latter inhibiting activity (hypoactivity), especially in the abundant pyramidal populations ‐see (Maestu et al., 2021) for more details. We assume that such interactions scale up to macroscopic regions in humans, specifically influencing resting‐state fMRI signals.MethodMultimodal data, including amyloid ([18F]Florbetapir) and tau ([18F]flortaucipir) PET, baseline resting‐state fMRI, structural and diffusion MRI, and clinical/cognitive indicators were obtained from the Alzheimer’s Disease Neuroimaging Initiative. The imaging modalities were processed to produce values for a parcellation consisting of 66 brain regions. We considered four neural masses interacting within a region. The regional excitatory and inhibitory activities then transform into BOLD signals (Valdes‐Sosa et al., 2009) ‐see Fig. 1A. Pyramidal excitabilities (v0E,k) contain the Aβ‐ and τ‐ parameters of interest, and their combined effect (Fig. 1B), which we estimated by minimizing the spectral distance between simulated signals and observations.ResultThe synergy between disease factors seems to change with disease states and subjects (Fig. 1C). Most of the considered healthy controls (HC) presented relatively low excitability change by Aβ and by τ, albeit having a greater, generally positive or ‘towards hypoactivity’ combined action. Mild cognitive impairment subjects appeared in two sub‐groups, one significantly close to the HC and another with stronger individual effects and smaller joined action. All AD patients presented positive synergistic effects and relatively high independent contributions to pyramidal population firing, as estimated from the data.ConclusionThe obtained significant, subject‐specific influences of pathological factors on neural activity verify the interactions reported by (Busche et al., 2020) in animal models experiments at the mesoscopic scale. There exist causal relationships between the amyloid and tau influence parameters and clinical variables. Further research must be performed to clarify characteristic disease trajectories as effective sub‐typing in early stages could improve therapeutic interventions.

Magnetic reconnection plasmoid model for Sagittarius A* flares

Context. Sagittarius A*, the supermassive black hole at the center of our Galaxy, exhibits episodic near-infrared flares. The recent monitoring of three such events with the GRAVITY instrument has shown that some flares are associated with orbital motions in the close environment of the black hole. The GRAVITY data analysis indicates a super-Keplerian azimuthal velocity, while (sub-) Keplerian velocity is expected for the hot flow surrounding the black hole. Aims. We develop a semi-analytic model of the Sagittarius A* flares based on an ejected large plasmoid, inspired by recent particle-in-cell global simulations of black hole magnetospheres. We model the infrared astrometric and photometric signatures associated with this model. Methods. We considered a spherical macroscopic hot plasma region that we call a large plasmoid. This structure was ejected along a conical orbit in the vicinity of the black hole. This plasmoid was assumed to be formed by successive mergers of smaller plasmoids produced through magnetic reconnection that we did not model. Nonthermal electrons were injected into the plasmoid. We computed the evolution of the electron-distribution function under the influence of synchrotron cooling. We solved the radiative transfer problem associated with this scenario and transported the radiation along null geodesics of the Schwarzschild space time. We also took the quiescent radiation of the accretion flow into account, on top of which the flare evolves. Results. For the first time, we successfully account for the astrometric and flux variations of the GRAVITY data with a flare model that incorporates an explicit modeling of the emission mechanism. The prediction of our model and recent data agree well. In particular, the azimuthal velocity of the plasmoid is set by the magnetic field line to which it belongs, which is anchored in the inner parts of the accretion flow, hence the super-Keplerian motion. The astrometric track is also shifted with respect to the center of mass due to the quiescent radiation, in agreement with the difference measured with the GRAVITY data. Conclusions. These results support the hypothesis that magnetic reconnection in a black hole magnetosphere is a viable model for the infrared flares of Sagittarius A*.

The Formalism of Milky-Way Antimatter-Domains Evolution

If baryosynthesis is strongly nonhomogeneous, macroscopic regions with antibaryon excess can be created in the same process from which the baryonic matter is originated. This exotic possibility can become real, if the hints to the existence of antihelium component in cosmic rays are confirmed in the AMS02 experiment, indicating the existence of primordial antimatter objects in our Galaxy. Possible forms of such objects depend on the parameters of models of baryosynthesis and evolution of antimatter domains. We elaborate the formalism of analysis of evolution of antibaryon domain with the account for baryon-antibaryon annihilation at the domain borders and possible “Swiss cheese” structure of the domain structure. We pay special attention to evolution of various forms of high, very high and ultrahigh density antibaryon domains and deduce equations of their evolution in the expanding Universe. The proposed formalism will provide the creation of evolutionary scenarios, linking the possible forms and properties of antimatter bodies in our Galaxy to the mechanisms of nonhomogeneous baryosynthesis.

Adaptive hierarchical multiscale modeling for concrete trans-scale damage evolution

This work presents an adaptive hierarchical multiscale approach for modeling the trans-scale damage evolution in concrete. The problem domain represented by an adaptive hierarchical multiscale finite element (FE) model is decomposed into two regions, namely the macroscopic elastic region and the multiscale critical region prone to damage. The former is simulated only by macroscopic elements, while the latter is modeled by both macroscopic elements and the coupled-volume mesoscopic FE samples assigned to the integration points belonging to these macroscopic elements. A model update criterion is proposed to adaptively identify the multiscale critical region during the loading process. Innovatively, the coupled-volume meso‑samples are randomly generated on the fly when the macroscopic integration points are first identified to be included in the multiscale critical region. Concrete damage at the macroscale is quantitatively characterized based on its mesoscopic counterpart thanks to the proposed partition-based averaging scheme. The numerical simulations demonstrate that the presented approach can track and quantify concrete trans-scale damage evolution. Importantly, in the simulation of a 480 mm-length dog-bone-shaped specimen, the number of degrees of freedom and computational time are only 8.35 and 17.57% of those of the direct mesoscale simulation, respectively.

CTNI-66. THE PREOPERATIVE BRAIN IRRADIATION IN GLIOBLASTOMA (POBIG) STUDY: A NOVEL TREATMENT PARADIGM TO IMPROVE OUTCOMES?

Abstract OBJECTIVE The Preoperative Brain Irradiation in Glioblastoma (POBIG) study evaluates for the first time the safety, feasibility, and impact of single fraction preoperative radiotherapy in newly diagnosed glioblastoma patients. METHODS Operable patients with a radiological diagnosis of glioblastoma, by consensus of a multidisciplinary tumor board including two dedicated neuro-radiologists, are screened for the study. Anatomical and functional MRI sequences are acquired for further tumor characterization and preoperative radiotherapy planning. Radiotherapy is delivered approximately two weeks after the initial screening. Radiation targets the macroscopic and microscopic tumor region at risk of being left behind during surgery and spares at least 2cc tumor volume being debulked to safeguard unperturbed and clinically relevant tissue examination and molecular profiling. The study dose-escalates (from 8Gy to 14Gy) based on the time-to-event Continual Reassessment Methodology. Subsequently, patients undergo surgical debulking followed by postoperative fractionated radiotherapy 60Gy/30fr with concurrent temozolomide. RESULTS The first POBIG study patient underwent preoperative radiotherapy followed by a subtotal resection of a left posterior fronto-opercular tumor and completed the postoperative chemoradiotherapy. Screening, study consent, MRI imaging and analysis, radiotherapy planning and delivery until surgery can be achieved within three weeks from screening while maintaining adequate and personalized patient communication. There were no surgical or radiotherapy delays or complications. During surgery, we successfully sampled unirradiated and irradiated tumor regions. The radiotherapy field covered the whole remnant tumor, and image-guided obtained tumor samples and imaging analysis showed clear evidence of differential radiation-induced changes. CONCLUSION We successfully initiated a new treatment strategy of preoperative radiotherapy for glioblastoma patients. The first patient completed the treatment, and the study is now open for further recruitment. Paired tumor sampling and advanced imaging analysis showed promising results. The POBIG study offers a unique opportunity for a paradigm shift towards personalized treatment regimens, hopefully leading to better outcomes.

Detecting the Deformation Behavior of Bimodal Ti-6Al-4V Using a Digital Image Correlation Technique.

The evolution of a local strain of the Ti-6Al-4V alloy subjected to tensile loading was investigated in situ by using the digital image correlation technique. The results show that some local strain concentration areas have already appeared in the elastic deformation stage, which then connected and became concentrated in the gauge region when the specimen yielded. The strain compatibility of grains in the macroscopic region is kept constant. The deformation process is further divided into six parts based on the development of the maximum strain gradient, and the strain compatibility of each stage of the alloy is summarized and analyzed. The quasi-in situ experiment reveals that the primary α(αp) grains undertake the main deformation at the micro-scale.

An h-adaptive local discontinuous Galerkin method for second order wave equation: Applications for the underwater explosion shock hydrodynamics

The underwater explosion (UNDEX) phenomenon involves hydrodynamic behaviors with a wide range of spatial scales, from macroscopic cavitation regions to refined areas with fluid-structure interactions around the shock wavefront. Correct description of the refined shock wavefront is important for determining the shock wave position and pressure peak. In this work, the local discontinuous Galerkin (LDG) method for the two-dimensional wave equation, which allows for the local triangular meshes refinement and merging during the shock wave propagation process, is presented to model the UNDEX shock hydrodynamics. This article is an extension of our previous work, where we discretize the UNDEX total wave formulation in the LDG framework and simulate the UNDEX shock wave and cavitation phenomenon. In order to save computational cost (including CPU time and computational storage) and capture the shock wavefront more accurately, the LDG method is extended to be in combination with the mesh adaption technique. The troubled-cell indicator, depending on the local jump of the pressure, is adopted to identify elements which require to be refined or coarsened. Typical numerical examples are tested to assess the capability of the present h-adaptive LDG method for capturing the UNDEX shock wave. The numerical results clearly demonstrate that the mesh adaption technique enables us to dynamically increase the mesh resolution in close proximity to the flow discontinuities with a large pressure jump. The local increase of the mesh resolution results in a substantial increase in the accuracy of the pressure peak. In terms of the computational efficiency, the h-adaptive LDG method can save nearly half of the calculation time in comparison to the non-adaptive LDG method on uniform meshes, whose mesh resolution is the same as that of the maximum level of refinement of the h-adaptive LDG method.

(Invited) Camera-Based Strain Visualization Using Carbon Nanotube Fluorescence

It is well known that each semiconducting species of single-wall carbon nanotube (SWCNT) gives distinct near-infrared fluorescence following excitation with visible light. Fundamental band gap modulation makes the peak emission wavelengths shift predictably when the nanotubes are deformed by axial stretching or compression. This effect forms the basis for a new method of mechanical strain measurement in which nanotubes are dilutely dispersed in thin polymer films applied to surfaces of interest. When the substrate is subsequently strained, load transfer through the film to the nanotubes causes small spectral shifts that are monitored through non-contact spectral measurements. We have demonstrated this method through successful strain mapping on specimens of aluminum, copper, steel, acrylic, polycarbonate, cement, and concrete, using point-by-point scanning. To improve the speed and convenience of SWCNT-based strain mapping, we are adapting the method to camera-based measurements. A macroscopic region of a coated specimen surface is illuminated with an excitation laser and the resulting SWCNT emission is imaged from a stand-off distance of ca. 50 cm by a near-IR sensitive camera. Multiple images are acquired through a tunable spectral filter to span the emission band of interest. The image data are then analyzed by spectrally fitting intensities at each pixel to find the local peak emission wavelength, from which the local strain value is deduced. The set of local strains is converted into a color-coded strain map showing detailed deformations of the specimen. We expect that the introduction of camera-based spectral strain measurement technology will lead to an important industrial application of SWCNTs.

Partial event coincidence analysis for distinguishing direct and indirect coupling in functional network construction

Correctly identifying interaction patterns from multivariate time series presents an important step in functional network construction. In this context, the widespread use of bivariate statistical association measures often results in a false identification of links because strong similarity between two time series can also emerge without the presence of a direct interaction due to intermediate mediators or common drivers. In order to properly distinguish such direct and indirect links for the special case of event-like data, we present here a new generalization of event coincidence analysis to a partial version thereof, which is aimed at excluding possible transitive effects of indirect couplings. Using coupled chaotic systems and stochastic processes on two generic coupling topologies (star and chain configuration), we demonstrate that the proposed methodology allows for the correct identification of indirect interactions. Subsequently, we apply our partial event coincidence analysis to multi-channel EEG recordings to investigate possible differences in coordinated alpha band activity among macroscopic brain regions in resting states with eyes open (EO) and closed (EC) conditions. Specifically, we find that direct connections typically correspond to close spatial neighbors while indirect ones often reflect longer-distance connections mediated via other brain regions. In the EC state, connections in the frontal parts of the brain are enhanced as compared to the EO state, while the opposite applies to the posterior regions. In general, our approach leads to a significant reduction in the number of indirect connections and thereby contributes to a better understanding of the alpha band desynchronization phenomenon in the EO state.

A Reinforcement Learning Based Traffic Control Strategy in a Macroscopic Fundamental Diagram Region

Urban traffic control systems (UTCSs) are deployed to a great number of urban cities despite lacking feedback when adjusting the traffic signals. The development of reinforcement learning (RL) makes it possible to apply feedback to UTCS, and great efforts have been made on RL-based traffic control strategies. However, those studies are regardless of the traffic flow theory of the network and the road users’ perspectives on the performance of traffic. This study proposes a multiagent reinforcement learning (MARL) based traffic control strategy, in which each intersection in a macroscopic fundamental diagram (MFD) region was controlled by one agent using the level of services (LOS) and MFD-based parameters as rewards. The proposed MARL strategy was evaluated by simulation in a 3×3 grid network compared with pretimed, actuated, and MFD-based traffic control strategies. The evaluation results showed that, at different demand levels, the proposed MARL strategy outperforms the other three traffic control strategies in terms of average intersection queue length and average intersection waiting time to a different extent. Results also showed that the proposed MARL dissipated the congestion faster than the other three control strategies. Results of the Friedman test indicated that the differences in performances between the proposed MARL and other strategies were statistically significant regardless of the demand level. The MFD in the testbed network controlled by the proposed MARL was different from that controlled by the pretimed strategy, especially the MFD scatter plot. It provides insights on considering the traffic flow theory of the network when applying MARL to traffic control strategies.

Local geometry of the rough-smooth interface in the two-periodic Aztec diamond

Random tilings of the two-periodic Aztec diamond contain three macroscopic regions: frozen, where the tilings are deterministic; rough, where the correlations between dominoes decay polynomially; smooth, where the correlations between dominoes decay exponentially. In a previous paper, the authors found that a certain averaging of height function differences at the rough-smooth interface converged to the extended Airy kernel point process. In this paper, we augment the local geometrical picture at this interface by introducing well-defined lattice paths which are closely related to the level lines of the height function. We show, after suitable centering and rescaling, that a point process from these paths converge to the extended Airy kernel point process provided that the natural parameter associated to the two-periodic Aztec diamond is small enough.

Quantum (hyper)computation through universal quantum gates in water coherent domains

According to quantum electrodynamics (QED), liquid water is composed by two phases, the first one characterized by a coherent state in which all the molecules oscillate in phase, the other by a non-coherent state in which they are all non-correlated. In the coherent state, the phase-correlated oscillations take place within macroscopic spatial regions called “coherent domains” (CD), admitting a spectrum of excited energy levels and generating, at their borders, an evanescent coherent e.m. field. When two or more excited CDs are sufficiently close to each other, the overlapping between their evanescent fields gives rise to a novel type of interaction due to the mutual exchange of virtual photons by quantum tunnel effect. Furthermore, when such water coherent domains are enclosed with waveguides consisting of suitable materials and design, these effects are stabilized and enhanced, allowing for the realization of an extended network of interacting coherent domains. In this paper, we’ll discuss how to exploit this dynamics to perform quantum computations by setting-up a set of universal quantum gates and calculate their operational time as a function the main parameters of the proposed physical model. We show this model can represent a basic architecture for a novel kind of quantum hyper-computer, characterized by a very high computational speed and able to overcame some of the main issues currently affecting the quantum computational frameworks so far proposed.

Fast and accurate control of gates for quantum hypercomputation based on coherent domains of water

Quantum electrodynamics (QED) predicts that, under suitable conditions for temperature and density, liquid water can be described as a two-phases system composed by a coherent and a non-coherent phase. The first one is characterized by the formation of macroscopic regions, called “;coherent domains” (CDs), in which all the molecules are phase - correlated among them and with a self-trapped electromagnetic field that leaks out from the CDs in the form of an evanescent tail. This feature, along with the possibility for the CDs to have an excited energy spectrum, allow them to interact each other through quantum tunneling of virtual photons. We have already shown how to exploit this dynamics to realize quantum hypercomputation by using a set of universal quantum gates made of interacting water CDs. In this paper we discuss how to accurately and fast control the macroscopic quantum states of such water coherent domains, by using electromagnetic potentials to modify the phase of their wavefunctions. Finally, a possible experimental set-up designed to this aim, based on the electric version of the Aharonov-Bohm effect, is discussed.

Mechanistic Analysis of Micro-Neurocircuits Underlying the Epileptogenic Zone in Focal Cortical Dysplasia Patients.

We aim to explore the microscopic neurophysiology of focal cortical dysplasia (FCD) induced epileptogenesis in specific macroscopic brain regions, therefore mapping a micro-macro neuronal network that potentially indicates the epileptogenic mechanism. Epileptic and relatively non-epileptic temporal neocortex specimens were resected from FCD and mesial temporal lobe epilepsy (mTLE) patients, respectively. Whole-cell patch-clamping was performed on cells from the seizure onset zone (SOZ) and non-SOZ inside the epileptogenic zone (EZ) of FCD patients, as well as the non-epileptic neocortex of mTLE patients. Microscopic data were recorded, including membrane characteristics, spontaneous synaptic activities, and evoked action potentials. Immunohistochemistry was also performed on parvalbumin-positive (PV+) interneurons. We found that SOZ interneurons exhibited abnormal neuronal expression and distribution as well as reduced overall function compared with non-SOZ and mTLE interneurons. The SOZ pyramidal cells experienced higher excitation but lower inhibition than the mTLE controls, whereas the non-SOZ pyramidal cells exhibited intermediate excitability. Action potential properties of both types of neurons also suggested more synchronized neuronal activity inside the EZ, particularly inside the SOZ. Together, our research provides evidence for a potential neurocircuit underlying SOZ epileptogenesis and non-SOZ seizure susceptibility. Further investigation of this microscopic network may promote understanding of the mechanism of FCD-induced epileptogenesis.

Coexistence of local structural heterogeneities and long-range ferroelectricity in Pb-free (1−x)Ba(Zr0.2Ti0.8)O3−x(Ba0.7Ca0.3)TiO3 ceramics

Environmentally benign (1-x)Ba(Ti$_{0.8}$Zr$_{0.2}$)O$_3$-x(Ba$_{0.7}$Ca$_{0.3}$)TiO$_3$ (BZT-BCT) ceramics are promising materials due to their remarkable high piezoresponse [Liu and Ren, Phys. Rev. Lett. \textbf{103}, 257602 (2009)]. In this Letter, by focusing on local and average structure in combination with macroscopic electromechanical and dielectric measurements we demonstrate the structure property relationship in the tetragonal BZT-BCT ceramic. During high-temperature cubic to tetragonal phase transformation, polar nanoregions are manifested through the spontaneous volume ferroelectrostriction at temperatures below $\sim$ 477 K. Temperature-dependent local structural investigations across the Zr K edge extended x-ray absorption fine structure spectroscopy reveal an anomalous collaboration between the ZrO$_{6}$ and TiO$_6$ octahedra. These octahedra compromise their individuality during polarization development. The presence of domains of submicron size embedded inside the macroscopic ferroelectric regions below T$_{m}$, as well as their hierarchical arrangement, is observed by piezo-response force microscopy. Effects of the existence of the structural/polar heterogeneities below T$_{m}$ are observed also when polarizibilities of the poled and the unpoled samples are compared; the poled sample is found to be more susceptible to the electric field. In addition, by using electric field dependent x-ray diffraction studies we also show that this ceramic under field exhibits reduction of tetragonal distortion, which is consistent with earlier reports.

From Picoscale Pathology to Decascale Disease: Image Registration with a Scattering Transform and Varifolds for Manipulating Multiscale Data.

Advances in neuroimaging have yielded extensive variety in the scale and type of data available. Effective integration of such data promises deeper understanding of anatomy and disease-with consequences for both diagnosis and treatment. Often catered to particular datatypes or scales, current computational tools and mathematical frameworks remain inadequate for simultaneously registering these multiple modes of "images" and statistically analyzing the ensuing menagerie of data. Here, we present (1) a registration algorithm using a "scattering transform" to align high and low resolution images and (2) a varifold-based modeling framework to compute 3D spatial statistics of multiscale data. We use our methods to quantify microscopic tau pathology across macroscopic 3D regions of the medial temporal lobe to address a major challenge in the diagnosis of Alzheimer's Disease-the reliance on invasive methods to detect microscopic pathology.