Average Motion Research Articles

Very-large-scale motions in typhoons and one possible original mechanism

Intensity typhoons are extreme wind environments encountered by coast and offshore structures, and vortex of different scales have different action mechanisms on the structure. A mature typhoon can be divided into three main parts, and from inner to outer, they are the eye, the eyewall, and the outer region. The spectrum characteristics may be different for the three parts of a typhoon. While nowadays the wind velocity spectra of typhoons in engineering applications are the same as those for the monsoon. In the current study, we conducted field measurements to analyze the characteristics of the wind velocity spectrum of the eye, eyewall, and outer region of a typhoon. For the outer and eye regions, the characteristic of the wind velocity spectrum is the same as the monsoon. For the eyewall region, a −1 subrange (k−1, k is wavenumber) occurs at the wind velocity spectrum, and the vortex structure size even reaches 32.1δ, which illustrates that very-large-scale motions (VLSMs) exist in this region. This is the first study to investigate VLSMs in a typhoon. Furthermore, we found that the −1 subrange of the wind velocity spectrum has a positive correlation with Reynolds shear stress. The phenomena established in the present study were validated by an established theory that states that flow should satisfy two conditions simultaneously for a −1 subrange: strong resonance between average and turbulent motions and a large wind velocity gradient. It may be that this theory is a possible original mechanism for VLSMs. Finally, we confirmed this mechanism with a flat plate shear flow field-measured test.

Correlating the Radiological Assessment of Patient Motion with the Incidence of Repeat Sequences Documented by Log Files

ObjectiveTo correlate a radiological assessment of MR motion artifacts with the incidence of repeated sequences and delays derived from modality log files (MLFs) and investigate the suitability of log files for quantifying the operational impact of patient motion. Materials and methodsAn experienced, blinded neuroradiologist retrospectively evaluated one full calendar month of sequentially obtained clinical MR exams of the head and/or brain for the presence of motion artifacts using a previously defined clinical grading scale. MLF data were analyzed to extract the occurrence of repeated sequences during the examinations. Statistical analysis included the determination of 95% confidence intervals for repetition ratios, and Welch's t-test to exclude the hypothesis of equal means for different groups of sequences. ResultsA total of 213 examinations were evaluated, comprising 1681 MLF-documented sequences, from which 1580 were archived. Radiological motion assessment scores (0, none to 4, severe) were assigned to each archived sequence. Higher motion scores correlated with a higher MLF-derived repetition probability, reflected by the average motion scores assigned to sequences that would be repeated (group 1, mean=2.5), those that are a repeat (group 2, mean=1.9), and those that are not repeated (group 3, mean=1.1) within an exam. The hypothesis of equal means was rejected with P = 5.9 × 10−5 for groups 1 and 2, P = 9.39 × 10−16 for groups 1 and 3, and P = 1.55 × 10−12 for groups 2 and 3. The repetition probability and associated time loss could be quantified for individual sequence types. The total time loss due to repeat sequence acquisition derived from MLFs was greater than four hours. ConclusionLog file data may help assess patterns of scanner and exam performance and may be useful in identifying pitfalls to diagnostic imaging in a clinical environment, particularly with respect to patient motion.

The Investigation of the Dynamical Evolution of Extrasolar Three-planetary System GJ 3138

This article is devoted to studying the dynamical evolution and orbital stability of compact extrasolar three-planetary system GJ 3138. In this system, all semimajor axes are less than 0.7 au. The modeling of planetary motion is performed using the averaged semi-analytical motion theory of the second order in planetary masses, which the authors construct. Unknown and known with errors orbital elements vary in allowable limits to obtain a set of initial conditions. Each of these initial conditions is applied for the modeling of planetary motion. The assumption about the stability of observed planetary systems allows to eliminate the initial conditions leading to excessive growth of the orbital eccentricities and inclinations and to identify those under which these orbital elements conserve moderate values over the whole modeling interval. Thus, it becomes possible to limit the range of possible values of unknown orbital elements and determine their most probable values in terms of stability.

Identification of a Telecom Wavelength Single Photon Emitter in Silicon.

We identify the exact microscopic structure of the G photoluminescence center in silicon by first-principles calculations with including a self-consistent many-body perturbation method, which is a telecommunication wavelength single photon source. The defect constitutes of C_{s}C_{i} carbon impurities in its C_{s}─Si_{i}─C_{s} configuration in the neutral charge state, where s and i stand for the respective substitutional and interstitial positions in the Si lattice. We reveal that the observed fine structure of its optical signals originates from the athermal rotational reorientation of the defect. We attribute the monoclinic symmetry reported in optically detected magnetic resonance measurements to the reduced tunneling rate at very low temperatures. We discuss the thermally activated motional averaging of the defect properties and the nature of the qubit state.

Toward a Distribution Difference-Based Passive Motion Detection System Using WiFi Signals

Passive motion detection (PMD) systems based on WiFi signals consider the traditional wireless network as a sensing network for detecting human motion. However, most WiFi-based PMD systems may perform poorly when the deployment environment changes (e.g., changes of transceiver or furniture placement). In addition, under the constraints of the limited devices and measurement noise, developing a robust and accurate motion detector is still heavily required. To this end, we propose R-MoDe to revisit the PMD problem from the perspective of the distribution difference of environmental statistics. First, R-MoDe exploits a statistical model based on temporal correlation function (TCF) to characterize the time-varying channel induced by human motion. Based on the statistical model, R-MoDe calculates environmental statistics by TCF and treats the distribution of the statistics under non-motion scenarios as a template profile, independent of the deployment environment and measurement noise. Next, with the limited devices, we regard available subcarriers as virtual sensors and design a clustering-vote-based sensor selection scheme to boost detection performance. Then, R-MoDe adopts the distance between the distribution of environmental statistics and the template profile as a robust detection metric. Finally, we propose a motion detection strategy based on double thresholds and hysteresis tracking to enable accurate and robust detection. R-MoDe is implemented on commodity WiFi devices in practical indoor environments. Experimental results show that R-MoDe can achieve an average motion detection rate of 96.19% and an average true negative rate of 97.04% using only one pair of transceivers, significantly outperforming the state-of-the-art methods.

Four-Dimensional Computed Tomography Scan Analysis of Liver Tumor Motion Treated With Abdominal Compression During Stereotactic Treatment of Liver

To explore the motion and influencing factors of implanted gold markers in guiding liver stereotactic body radiation therapy using abdominal compression.Twenty patients with oligometastatic colorectal cancer or primary hepatocellular carcinoma from January 2016 to December 2019 were included. All patients were treated with stereotactic body radiation therapy (SBRT) under abdominal compression, with 1-3 gold markers implanted within 2cm of the lesion before positioning, meanwhile four-dimensional computed tomography (4DCT) scan used for treatment planning. The respiratory cycle was divided into 0%-90% respiratory phase image based on the respiratory signal, which were reconstructed by the system as well as CBCT validation images before radiation exposure daily. The liver volume was divided into 3 parts: within 2 cm of the main hepatic portal vein, 2-5 cm of the main hepatic portal vein, and 5 cm outside of the main hepatic portal vein, for evaluating the motion of different tumor locations.The average intrafractional motion amplitude (mean ± standard deviation) was 2.63 ± 2.81 mm in the cranial-caudal (CC), 1.35 ± 1.23 mm in the anterior-posterior (AP), and 0.76 ± 0.88 mm in the left-right (LR) direction, respectively. Meanwhile the average interfractional motion amplitude was 3.45 ± 3.06 mm, 2.64 ± 2.60 mm, and 2.23 ± 2.07 mm, respectively. Whether intra- or interfraction, the motion amplitude showed CC > AP > LR direction (P < 0.001). The motion varied at different tumor location, the further away from the main hepatic portal vein, the larger of the intrafractional motion. To cover the 95% population-based confidence interval, internal target volume was suggested to include the expansion of 3.9 mm, 5.2 mm and 7.9 mm in the LR, AP, and CC direction, while 4.3 mm, 4.4 mm, and 6.1 mm within 2 cm of the main hepatic portal vein, 3.5 mm, 7.3 mm, and 9.7 mm outside 5 cm of the main hepatic portal vein, respectively. The expansion varied significantly depending on tumor location, but motion in CC direction showed the largest no matter where the tumor was. Among the 3 parts of liver volume, while the further of tumor away from the main portal vein, the larger expansion in CC direction, and tumor in 5 cm outside of the main portal vein moved more than other inner parts in AP direction.Different tumor locations of liver require external expansion of internal target volume individually.Y. Zhao: None. Y. Tang: None. W. Liu: None. N. Li: None. Y. Song: None. S. Wang: None. Y. Liu: None. H. Fang: None. N. Lu: None. Y. Tang: None. S. Qi: None. Y. Yang: None. B. Chen: None. Y. LI: None. J. Jin: None.

Feasibility of Ablative SBRT Treatment of Pancreas Patients on an MR-Linac

To report on our early experience of treating patients with pancreas ductal adenocarcinoma (PDAC) with ablative SBRT (50 Gy in 5 fractions) on the Elekta Unity MR-Linac.Ten PDAC patients were treated with abdominal compression (AC) and daily online plan adaptation using Adapt-to-Shape (ATS) workflow. AC is the method of choice to reduce breathing motion since automatic breath-hold/gating or other motion management options are not yet available on Unity MR-Linac. Three tumors were located in the head of the pancreas and seven were in the body. Seven patients were considered inoperable per surgeon and six were node positive. Average GTV volume during simulation was 42.5 ± 24.8 cc. Three orthogonal plane cine MRI were acquired to assess AC belt pressure during MR simulation as well as during each treatment fraction to assess stability of AC in minimizing tumor motion. Three sets of 3D T2w MR scans, pre-treatment (MRIpre), verification (MRIver) and post-treatment (MRIpost) MRI, were acquired for online planning. To assess the dosimetric impact of intrafraction organ motion, a post-treatment quality assurance (QA) was performed before the next fraction by propagating pre-treatment plan and structures to both MRIver and MRIpost, editing the contours and recalculating dose. GTV coverage and selected organs-at-risk (OAR) dose constraints (e.g., < 33 Gy to 0.035 cc, < 25 Gy to 2 cc and < 25 Gy to 5cc volume) were evaluated on MRIver and MRIpost.Median total treatment time was 75.5(49-132) minutes. Average contouring, planning, physics QA and beam-on time was 25.1 ± 11.9, 12.2 ± 6.0, 1.9 ± 1.5 and 14.1 ± 3.7 mins respectively. Average AP, LR and SI motion in FB and with compression was 0.3 ± 0.1, 0.6 ± 0.2 and 0.7 ± 0.2 and 0.2 ± 0.1, 0.2 ± 0.1, 0.4 ± 0.1 cm respectively, indicating that compression belt was effective in minimizing patient breathing motion. Average tumor motion in AC belt for all fractions was 0.2 ± 0.1, 0.2 ± 0.1 and 0.4 ± 0.2 cm in AP, LR and SI direction. Median GTV coverage was 78.7% of Rx dose for all fractions. Average GTV Dmax and GTV mean dose for all the fractions was 57.4 ± 0.7 and 51.2 ± 1.6 Gy respectively. Average 0.035 cc, D2cc and D5cc stomach dose was 34.4 ± 5.4, 26.7 ± 2.9 and 24.3 ± 2.1 Gy on MRIver and 35.3 ± 6.2, 27.0 ± 3.3 and 24.6 ± 2.5 Gy on MRIpost. Average 0.035 cc, D2cc and D5cc small bowel dose was 35.1 ± 6.3, 27.1 ± 3.6 and 24.4 ± 2.6 Gy on MRIver and 35.5 ± 6.5, 27.3 ± 3.9 and 24.6 ± 2.5 Gy on MRIpost.MR-guided adaptive RT enables delivery of curative dose to pancreatic tumors by taking into account interfraction motion of gastrointestinal OARs in daily adaptive planning. To manage intrafraction motion in our current clinical workflow, the organ motion is assessed for first two fractions and conservative strategies (e.g., bigger PRV margins or change the directive to keep stomach 0.035 cc dose to < 30 Gy) are employed for later fractions. ATS workflow with AC and the post-treatment QA allow safe delivery of ablative radiation doses for selected cases of PDAC on Unity MR-Linac.N. Tyagi: Honoraria; Elekta. Travel Expenses; Elekta; ISMRM.J. Liang: None. S. Burleson: None. E. Subashi: None. P. Godoy Scripes: None. K.R. Tringale: None. P.B. Romesser: Travel Expenses; Elekta. M. Reyngold: None. C.H. Crane: Honoraria; Elekta. Travel Expenses; Elekta.

(Invited) Single-Electron Manipulation in an Attofarad-Capacitor DRAM

Miniaturization of Si field-effect transistors (FETs) has continuously increased the performance of data processing circuits and expanded semiconductor markets. This trend is expected to accelerate with the advent of the internet-of-things (IoT) society supported by new technologies such as the 5th-generation mobile network and artificial-intelligence systems. In the meantime, since the number of electronic devices will increase with the development of the IoT society, their total energy consumption will increase, which will give rise to serious issues in the near future.Here, aiming for sustainable development of the IoT society, we introduce a single-electron device based on a dynamic random access memory (DRAM) in which a single electron is used as one bit of information. In the DRAM, the motion of a single electron is controlled and then the electron is stored in an attofarad capacitor using a FET in which leakage current is suppressed to the theoretical limit. The charge signal of the electron is amplified by another FET integrated in the DRAM. Miniaturization of the DRAM enables such operation based on single electrons to be performed at room temperature.Such single-electron manipulation in the DRAM makes it function as a multilevel memory. Since the DRAM can manipulate the number of electrons in the capacitor, it can store data information according it. This feature provides the DRAM with a multilevel-memory function, in which each memorized state is represented by one electron. In addition, extremely long retention time is also possible because charge leakage from the capacitor can be suppressed to the theoretical lower limit. These functions are not available in conventional DRAMs.Another application based on the nature of an electron is also demonstrated. Since the motion of a single electron is essentially random, this randomness is used as physical random numbers for data processing based on the spin-glass model. This model promises efficient data processing for image restoration and optimization problems. Using random motion of individual electrons and its average controllability using the FETs, random flipping of spins is emulated by electron motion and the interaction between spins are represented by the average motion of electrons. As a result, we have succeeded in demonstrating data restoration.In these applications, one electron is used as one bit of information. However, the power consumption in electronic devices does not simply decrease if the number of electrons representing one bit is reduced. Thermodynamically, the lower limit of energy consumption is given by kTln2 (k is the Boltzmann constant; T is absolute temperature), which is known as Landauer’s limit. Landauer’s limit provides the fundamental relationship between "Information" and "Energy" and has a strong implication of "Energy" for dealing with "Information". On the other hand, a more substantive idea linking "Information" and "Energy" is Maxwell's demon, which is a thought experiment proposed by James C. Maxwell. Therefore, we believe that in order to achieve the ultimate reduction of power consumption in electronic devices, it is very important to understand Landauer’s limit and Maxwell’s demon and to expand their concepts to devices. For this purpose, we demonstrated power generation in an analogy to Maxwell’s demon. Using the DRAM for single-electron manipulation, random motions of electrons are monitored, and the electrons are guided in a certain direction in which the potential energy is high. Since this demonstration is achieved by using FETs, we can expect not only other demonstrations of proposals for lowering the power consumption of data processing but also applications inspired from such demonstrations in the future.Since the use of nanometer-scale FETs guarantees high stability and controllability, the device can be used as an optimum platform for carrying out demonstrations of some theoretical proposals. Since a small structure is essential for realizing this device and others like it, FETs fabricated with future advanced fabrication technology as well as other small materials such as graphene, carbon nanotubes, and molecules are promising for further progress in this field.

Residual quadrupolar couplings observed in 7 Tesla deuterium MR spectra of skeletal muscle.

PurposeDeuterium metabolic imaging could potentially be used to investigate metabolism in skeletal muscle noninvasively. However, skeletal muscle is a tissue with a high degree of spatial organization. In this study, we investigated the effect of incomplete motional averaging on the naturally abundant deuterated water signal in 7 Tesla deuterium spectra of the lower leg muscles and the dependence on the angle between the muscle fibers and the main magnetic field B0, as determined by DTI.MethodsNatural abundance deuterium MRSI measurements of the right lower leg muscles were performed at 7 Tesla. Three subjects were scanned in a supine position, with the right leg parallel with the B0 field. One subject was scanned twice; during the second scan, the subject was laying on his right side and the right knee was bent such that the angle between the right lower leg and B0 was approximately 45°. DTI was performed in the same subjects in the same positions at 3 Tesla to determine muscle fiber angles.ResultsWe observed splittings in the natural abundance deuterated water signal. The size of the splittings varied between different muscles in the lower leg but were mostly similar among subjects for each muscle. The splittings depended on the orientation of the muscle fibers with respect to the main magnetic field B0.ConclusionPartial molecular alignment in skeletal muscle leads to residual deuteron quadrupolar couplings in deuterated water, the size of which depends on the angle between the muscle fibers and B0.

Optimization and evaluation of motion sequences of an averaged human motion model by using kinematic techniques and new evaluation methods

Abstract Signal processing, pattern recognition as well as modelling and simulation require a large amount of reference data, both for the development of new methods and for their evaluation. Depending on the application, the availability of databases is rather low. In the field of biosignal processing with a focus on the functionalization of furniture for nursing and hospital facilities, a database from a motion capturing system (MoCap), and a method to generate averaged human motion sequences was presented in subsequent works by our research group. Evaluations revealed that the averaged motion sequences partly contain artifacts caused by the averaging and thus are not directly usable. To use the averaged motion sequences e.g., in simulation tasks, this paper presents an extension with kinematic methods to combine averaged motion sequences and to suppress and thus optimize inappropriate motion artifacts by error correction. To check whether the results are usable after the processing steps, four evaluation criteria are proposed. The evaluation of the resulting motion sequences shows that sequences are generated which do not fully correspond to human motion sequences but are well suited for simulation tasks.

Second-order fast–slow dynamics of non-ergodic Hamiltonian systems: Thermodynamic interpretation and simulation

A class of fast–slow Hamiltonian systems with potential Uɛ describing the interaction of non-ergodic fast and slow degrees of freedom is studied. The parameter ɛ indicates the typical timescale ratio of the fast and slow degrees of freedom. It is known that the Hamiltonian system converges for ɛ→0 to a homogenised Hamiltonian system. We study the situation where ɛ is small but positive.First, we rigorously derive the second-order corrections to the homogenised (slow) degrees of freedom. They can be decomposed into explicitly given terms that oscillate rapidly around zero and terms that trace the average motion of the corrections, which are given as the solution to an inhomogeneous linear system of differential equations.Then, we analyse the energy of the fast degrees of freedom expanded to second-order from a thermodynamic point of view. In particular, we define and expand to second-order a temperature, an entropy and external forces and show that they satisfy to leading-order, as well as on average to second-order, thermodynamic energy relations akin to the first and second law of thermodynamics.Finally, we analyse for a specific fast–slow Hamiltonian system the second-order asymptotic expansion of the slow degrees of freedom from a numerical point of view. Their approximation quality for short and long time frames and their total computation time are compared with those of the solution to the original fast–slow Hamiltonian system of similar accuracy.

Design of a dexterous robotic surgical instrument with a novel bending mechanism.

The robot-assisted minimally invasive surgery (RMIS) has developed rapidly in recent years, requiring highly articulated instruments to enable surgeons to perform complicated and precise procedures. A novel wrist-type surgical instrument was proposed for RMIS. The wrist consists of superelastic-wire-driven snake-like joints and universal joints, which could perform two deflections and one distal rotation. The bending mechanism and the kinematics of universal joints were analysed. The forward and inverse kinematics of the wrist were derived. The performances of the instrument were evaluated using a prototype by experiments. The average motion deviation of the wrist's deflection was 0.15±0.08 mm, and the maximum deviation was 0.52 mm. The maximum payload capability was 10 N. The suture task and ex vivo procedure verified the effectiveness of the instrument. The proposed instrument has high dexterity and payload capability, which contributes to improving the quality of the RMIS procedures.

Durotaxis of Passive Nanoparticles on Elastic Membranes.

The transport of macromolecules and nanoscopic particles to a target cellular site is a crucial aspect in many physiological processes. This directional motion is generally controlled via active mechanical and chemical processes. Here we show, by means of molecular dynamics simulations and an analytical theory, that completely passive nanoparticles can exhibit directional motion when embedded in nonuniform mechanical environments. Specifically, we study the motion of a passive nanoparticle adhering to a mechanically nonuniform elastic membrane. We observe a nonmonotonic affinity of the particle to the membrane as a function of the membrane's rigidity, which results in the particle transport. This transport can be both up or down the rigidity gradient, depending on the absolute values of the rigidities that the gradient spans across. We conclude that rigidity gradients can be used to direct average motion of passive macromolecules and nanoparticles on deformable membranes, resulting in the preferential accumulation of the macromolecules in regions of certain mechanical properties.

Membrane Interactions of Latarcins: Antimicrobial Peptides from Spider Venom.

A group of seven peptides from spider venom with diverse sequences constitute the latarcin family. They have been described as membrane-active antibiotics, but their lipid interactions have not yet been addressed. Using circular dichroism and solid-state 15N-NMR, we systematically characterized and compared the conformation and helix alignment of all seven peptides in their membrane-bound state. These structural results could be correlated with activity assays (antimicrobial, hemolysis, fluorescence vesicle leakage). Functional synergy was not observed amongst any of the latarcins. In the presence of lipids, all peptides fold into amphiphilic α-helices as expected, the helices being either surface-bound or tilted in the bilayer. The most tilted peptide, Ltc2a, possesses a novel kind of amphiphilic profile with a coiled-coil-like hydrophobic strip and is the most aggressive of all. It indiscriminately permeabilizes natural membranes (antimicrobial, hemolysis) as well as artificial lipid bilayers through the segregation of anionic lipids and possibly enhanced motional averaging. Ltc1, Ltc3a, Ltc4a, and Ltc5a are efficient and selective in killing bacteria but without causing significant bilayer disturbance. They act rather slowly or may even translocate towards intracellular targets, suggesting more subtle lipid interactions. Ltc6a and Ltc7, finally, do not show much antimicrobial action but can nonetheless perturb model bilayers.

Intrinsic anisotropy parameters of a series of lanthanoid complexes deliver new insights into the structure-magnetism relationship

Intrinsic anisotropy parameters of a series of lanthanoid complexes deliver new insights into the structure-magnetism relationship

Asymptotic behavior of the weak approximation to a class of Gaussian processes

AbstractWe study, under mild conditions, the weak approximation constructed from a standard Poisson process for a class of Gaussian processes, and establish its sample path moderate deviations. The techniques consist of a good asymptotic exponential approximation in moderate deviations, the Besov–Lèvy modulus embedding, and an exponential martingale technique. Moreover, our results are applied to the weak approximations associated with the moving average of Brownian motion, fractional Brownian motion, and an Ornstein–Uhlenbeck process.

Wide-Awake Approach for Flexor Digitorum Superficialis Tendon Transfer Followed by Early Active Mobilization.

Background The standard clinical practice to treat closed ruptures of the flexor digitorum profundus (FDP) tendons includes free tendon grafting; however, it is not suitable when the muscle amplitude of the ruptured FDP is not sufficient. We report outcomes of six patients who underwent flexor digitorum superficialis (FDS) tendon transfer of the ring finger using the wide-awake approach to repair the closed rupture of the FDP tendon of the little finger in zone 3 or 4. Methods The patients were identified by reviewing our institutional billing records from January 2012 to October 2019 for the International Classification of Disease 10 code M66.3 that describes the diagnosis as “spontaneous rupture of flexor tendons.” Results The patients comprised two men and four women with an average age of 72.2 years (standard deviation [SD], 8.4 years). All patients were hospitalized after surgery to undergo early active mobilization. The average total active motion at the final evaluation was 201.8° (range: 85–248°). According to Strickland’s criteria, outcomes were excellent for two, good for three, and poor for one patient. No patients complained about the ring finger. Conclusion These results suggest that FDS tendon transfer is recommended when the muscle amplitude of the ruptured FDP is insufficient. We believe that the wide-awake approach and early active mobilization may contribute to satisfactory outcomes.

Automatic Recognition Method of Letter Images in English Self-Learning Based on Partial Differential Equation Method

According to the current situation of knowledge popularization, students simply rely on the knowledge learned in the classroom that is far from adapting to the development of modern society; so, every student needs to have the consciousness and ability of independent learning. The research of the English self-help learning system based on partial differential equation method comes into being with information network technology as the foundation for survival and development. The existing partial differential equation recognition models based on average curvature motion are all edge-based and need to use the external force defined by the image gradient to attract the zero level set (evolution curve) to move to the target edge and finally stay on the target edge. Therefore, it is difficult to obtain ideal results when extracting fuzzy or discrete boundaries (perceptual boundaries), and it is very sensitive to the selection of initial contour and noise. To solve this problem, this paper proposes a new recognition model of partial differential equations based on mean curvature motion. This overcomes some defects of existing edge models because it is region-based and does not require image gradient as a condition to stop evolution. The proposed model can avoid manual initial curve selection and allow stopping conditions to be set in the algorithm. In addition, in the numerical solution of partial differential equations, the existing model uses upwind difference scheme, and the semi-implicit additive operator separation method is adopted in this paper. Some other layers are added, and some hyperparameters are adjusted when the convolutional neural networks of inception PDEs are constructed by stacking the structure of inception PDEs. In the contrast experiment with the prototype, the software and hardware environment are the same, and the input is exactly the same. For the handwritten English alphabet data set, the variant structure can obtain more than 90% of the training accuracy and verification accuracy, which is better than the experimental accuracy of the prototype. In addition, because the inception PDE structure contains fewer parameters than the prototype, it is more computationally efficient and takes less training time per batch than the prototype.

Effects of bariatric surgery on functional connectivity of the reward and default mode network: A pre-registered analysis.

Obesity imposes serious health risks and involves alterations in resting‐state functional connectivity of brain networks involved in eating behavior. Bariatric surgery is an effective treatment, but its effects on functional connectivity are still under debate. In this pre‐registered study, we aimed to determine the effects of bariatric surgery on major resting‐state brain networks (reward and default mode network) in a longitudinal controlled design. Thirty‐three bariatric surgery patients and 15 obese waiting‐list control patients underwent magnetic resonance imaging at baseline, after 6 and 12 months. We conducted a pre‐registered whole‐brain time‐by‐group interaction analysis, and a time‐by‐group interaction analysis on within‐network connectivity. In exploratory analyses, we investigated the effects of weight loss and head motion. Bariatric surgery compared to waiting did not significantly affect functional connectivity of the reward network and the default mode network (FWE‐corrected p > .05), neither whole‐brain nor within‐network. In exploratory analyses, surgery‐related BMI decrease (FWE‐corrected p = .041) and higher average head motion (FWE‐corrected p = .021) resulted in significantly stronger connectivity of the reward network with medial posterior frontal regions. This pre‐registered well‐controlled study did not support a strong effect of bariatric surgery, compared to waiting, on major resting‐state brain networks after 6 months. Exploratory analyses indicated that head motion might have confounded the effects. Data pooling and more rigorous control of within‐scanner head motion during data acquisition are needed to substantiate effects of bariatric surgery on brain organization.

The Global Fingerprint of Modern Ice‐Mass Loss on 3‐D Crustal Motion

AbstractCrustal motion generated by rapid ice‐mass loss from Earth's glaciers and ice sheets has previously been considered in Global Navigational Satellite System (GNSS) analyses and numerical models across regions of ice retreat. However, the fingerprint of ice‐mass loss is not limited to glaciated areas, but is characterized by a global pattern of 3‐D crustal deformation. We compute “far‐field” vertical and horizontal deformation rates that occurred in response to early 21st century mass flux from the Greenland and Antarctic Ice Sheets, global glaciers and ice caps, and associated ocean loading. We demonstrate that mass changes in the Greenland Ice Sheet and high latitude glacier systems each generated average crustal motion of 0.1–0.4 mm/yr across much of the Northern Hemisphere, with significant year‐to‐year variability in magnitude and direction. Horizontal motions associated with ice‐mass loss exceed vertical rates in many far‐field areas, and both should be considered in future analysis of GNSS measurements.