Hand Side Research Articles

The East Asian monsoon variability in the Nihewan Basin, northern China, during the Early Pleistocene: A grain size end-member modelling analysis

The Pleistocene sediments of the Nihewan Basin in northern China preserve a detailed terrestrial sediment archive for reconstructing the palaeoenvironment and palaeoclimate changes during early times of hominin occupation in E Asia, following the earliest locations outside of Africa. In this study, we investigate the composite 86.2-m long NH-T section of Dachangliang which was formed with an astronomically tuned age between ca. 1.66 and 0.78 Ma. Parameterized grain size end-member modelling analysis is applied for the first time in the Nihewan Basin to unravel the characteristics of sediment sources, transportation dynamics, and climatic signals in the region. The grain-size distributions of the NH-T sediment samples are attributed to a mixture of four distinct end members (EMs 1-4). EM 1 represents a global atmospheric fine silt component (mode at 7.9 μm) which probably resulted from high-altitude westerly transport from distal sources. EM 2, a medium silt component (mode at 27.6 μm) was probably transported by the low-level westerly winds during the spring from a relatively proximal source in comparison to EM 1. EM 3, a coarse silt component (mode at 59.9 μm), represents short distance suspended materials that were blown out by N or NW winds of the East Asian winter monsoon (EAWM). EM 4 is a fine sand component (mode at 221.1 μm), probably representing fluvial deposits carried by overland flow. Therefore, the temporal fluctuations in the abundances of EMs 1-3 are used to infer the history of the East Asian summer monsoon (EASM) (EM 1), of dust-storm outbreaks during springtime (EM 2), and of the EAWM (EM 3). The NH-T climate record shows an overall increase in EM 3 peaks, accompanied by a decrease in EM 1 minima from ca. 1.45 to 0.82 Ma, indicating a long-term aridification and cooling trend in the Nihewan Basin. At ca. 1.25 Ma, the EM patterns transition from short-frequency to longer fluctuations, apparently coinciding with the onset of the Mid-Pleistocene transition (MPT). Periods of stronger EASM with more frequently warm and wet conditions probably occurred in the basin between ca. 1.66-1.62, 1.52-1.25 and after 0.82 Ma. Intensified EAWM conditions probably prevailed in the basin during the intervening periods from ca. 1.62-1.52 and the MPT 1.25-0.82 Ma. The inferred warmer and wetter conditions likely supported hominin activities in the Nihewan Basin, in contrast to mostly colder and drier conditions. Nevertheless, the higher number of discovered Palaeolithic sites and recorded lithic artifacts from the first half of the MPT apparently reflects the successful adaptability of hominins to the prevailing cold climate. The relatively consistent patterns observed between the variations of a median grain-size stack of the Chinese Loess Plateau (CLP MD) and EM 3, and of the magnetic susceptibility stack of the CLP (CLP MS) and EM 1, indicate the climatic sensitivity of these EMs in response to the long-term glacial/interglacial oscillations previously inferred from the CLP. However, significant differences in the CLP MD and CLP MS on the one hand side and in the trends of the EMs 3 and 1 on the other suggest that regional climate conditions varied between the CLP and the Nihewan Basin. Further research is required to explore such regional climate differences and their possibly underlying factors in the Early Pleistocene.

Integrability conditions for Boussinesq type systems

The symmetry approach to the classification of evolution integrable partial differential equations (see, for example (Mikhailov et al.,1991)) produces an infinite series of functions, defined in terms of the right hand side, that are conserved densities of any equation having infinitely many infinitesimal symmetries. For instance, the function ∂f∂ux has to be a conserved density of any integrable equation of the KdV type ut=uxxx+f(u,ux). This fact imposes very strong conditions on the form of the function f. In this paper we construct similar canonical densities for equations of the Boussinesq type. In order to do that, we write the equations as evolution systems and generalise the formal diagonalisation procedure proposed in Mikhailov et al. (1987) to these systems.

Improving approximation accuracy in Godunov-type smoothed particle hydrodynamics methods

The study examines the origin of errors resulting from the approximation of the right hand sides of the Euler equations using the Godunov type contact method of smoothed particle hydrodynamics (CSPH). The analytical expression for the numerical shear viscosity in CSPH method is obtained. In our recent study the numerical viscosity was determined by comparing the numerical solution of momentum diffusion in the shear flow with theoretical one. In this study we deduce the analytical expression for the numerical viscosity which is found to be similar to numerical one, confirming the obtained results. To reduce numerical diffusion, diffusion limiters are typically applied to expressions for contact values of velocity and pressure, as well as higher-order reconstruction schemes. Based on the performed theoretical analysis, we propose a new method for correcting quantities at interparticle contacts in CSPH method, which can be easily extended to the MUSCL-type (Monotonic Upstream-centered Scheme for Conservation Laws) method. Original CSPH and MUSCL-SPH approaches and ones with aforementioned correction are compared.

Worst-case analysis of restarted primal-dual hybrid gradient on totally unimodular linear programs

We analyze restarted PDHG on totally unimodular linear programs. In particular, we show that restarted PDHG finds an ϵ-optimal solution in O(Hm12.5nnz(A)log⁡(Hm2/ϵ)) matrix-vector multiplies where m1 is the number of constraints, m2 the number of variables, nnz(A) is the number of nonzeros in the constraint matrix, H is the largest absolute coefficient in the right hand side or objective vector, and ϵ is the distance to optimality of the outputted solution.

Ergonomic and sustainable posture for gynecological laparoscopic surgeons determined based on images analyzed using artificial intelligence.

Studies have reported the emergence of work-related musculoskeletal disorders (WMSD) due to surgery. In fact, the usfige of long-shafted instruments has been suspected to induce WMSD in laparoscopic surgery. The present study therefore investigated whether differences in the range of motion of the face and neck, and the shoulder, elbow and hand on the dominant hand side, existed when using short- and long-shafted laparoscopic coagulation shears (LCS) during a gynecological laparoscopic surgery, based on images analyzed using artificial intelligence. After identifying the corresponding body parts in the video, the range of motion was illustrated graphically for each joint coordinate, followed by statistical analysis for changes in the position of each part. The range of motion for the face and neck did not significantly differ, whereas those for the shoulder, elbow and hand became noticeably broader when using the 36-cm long-shafted LCS than when using the 20-cm short-shafted LCS. Overall, the shorter LCS promoted a narrower range of motion compared with the 36-cm LCS, suggesting its potential for reducing the physical strain placed on the surgeon's body during gynecological laparoscopic surgery.

Minimum and early high-energy sonication protocol of MR-guided focused ultrasound thalamotomy for low-skull density ratio patients with essential tremor and Parkinson's disease.

MR-guided focused ultrasound (MRgFUS) thalamotomy is an incisionless neurosurgical treatment for patients with medically refractory essential tremor and tremor-dominant Parkinson's disease. A low skull density ratio (SDR) < 0.40 is a known risk factor for treatment failure. The aim of this study was to identify useful sonication strategies for patients with a low SDR < 0.40 by modifying the standard sonication protocol using maximum high-energy sonication while minimizing the number of sonications. The authors retrospectively analyzed the effects of modified MRgFUS sonication on low-SDR tremor patients. All patients underwent head CT scans to calculate their SDR. The SDR threshold for MRgFUS thalamotomy was 0.35. The patients in the early series underwent the standard sonication protocol targeting the ventral intermediate nucleus contralateral to the treated hand side. The patients with a low SDR < 0.40 in the late series underwent a modified sonication protocol, in which the number of alignment sonications was minimized and high-energy treatment sonication (> 36,000 J) was used. The authors evaluated the lesion volume the following day and tremor improvement and adverse events 3 and 12 months after the procedure. The sonication patterns between low-SDR patients treated using different sonication protocols were examined using Fisher's exact test. ANOVA was used to examine the lesion volume and tremor improvement in high- and low-SDR patients treated using different sonication protocols. Among 41 patients with an SDR < 0.40, 14 underwent standard sonication and 27 underwent modified sonication. Fewer alignment sonications and high-energy treatment sonications were used in the modified sonication group compared with the standard group (p < 0.001). The duration of modified sonication was significantly shorter than that of standard sonication (p < 0.001). The lesion volume and tremor improvement significantly differed among the high- and low-SDR groups with different sonication protocols (p < 0.001). Low-SDR patients treated using modified sonication protocols had comparable lesion volume and tremor improvement to the high-SDR group. The modified sonication protocol did not significantly increase adverse intraprocedural and postprocedural events. Minimizing alignment sonications and applying high-energy sonication in early treatment help to create an optimal lesion volume and control tremor in low-SDR patients.

Complete topological asymptotic expansion for L2 and H1 tracking-type cost functionals in dimension two and three

In this paper, we study the topological asymptotic expansion of a topology optimisation problem that is constrained by the Poisson equation with the design/shape variable entering through the right hand side. Using an averaged adjoint approach, we give explicit formulas for topological derivatives of arbitrary order for both an L2 and H1 tracking-type cost function in both dimension two and three and thereby derive the complete asymptotic expansion. As the asymptotic behaviour of the fundamental solution of the Laplacian differs in dimension two and three, also the derivation of the topological expansion significantly differs in dimension two and three. The complete expansion for the H1 cost functional directly follows from the analysis of the variation of the state equation. However, the proof of the asymptotics of the L2 tracking-type cost functional is significantly more involved and, surprisingly, the asymptotic behaviour of the bi-harmonic equation plays a crucial role in our proof.

Effects of External Pacing Type on the Cross-Education of Motor Skill

Cross-education (CE) is a phenomenon whereby motor training of one limb leads to improved performance in the opposite untrained limb. External pacing of a motor task can enhance CE; however, the influence of different pacing methods is poorly understood. This study explored how motor training with auditory (AP) and visual pacing (VP) impacts CE with a visuomotor force target task. Sixty-one participants performed a unimanual motor task. Participants were randomized into a visual (n = 31) or auditory (n = 30) pacing stimuli condition. The primary outcome was cumulative error scores for each hand, before and after visuomotor training. Pacing type did not yield different magnitudes of CE. However, after adjusting for baseline differences, a significant hand (trained vs. untrained) × practice side (dominant or non-dominant) interaction (p = .013, η p 2 = .106) and a group main effect (p = .036, η p 2 = .165) were observed. Visual pacing resulted in greater improvements in task performance compared to auditory pacing regardless of hand or practice side, while training the dominant limb resulting in a greater interlimb asymmetry regardless of pacing stimulus. These findings have implications for applying pacing strategies during rehabilitation from unilateral injury or neurological impairment.

Metrology for sensor networks: metrological traceability and measurement uncertainties for air quality monitoring

Abstract In situ calibration of sensors delivering SI traceable measurement results still provides an open question to the design and operation of sensor networks. Particularly when addressing low-cost sensors, currently, the use of sensor networks for air quality monitoring is limited by the low or unknown accuracy of measurements that they can achieve, while the data quality of individual sensor networks is mainly derived by algorithms. Standardization bodies like DIN and CEN therefore announced the need for investigations of validation methods on gas phase species and particulate matter on the one hand side, and for the development of fully digitized quality assurance/quality control and calibration techniques for sensor networks on the other (CEN/CENELEC, Opportunity for Standardisation to Contribute to the European Partnership on Metrology EPM under Horizon Europe). This contribution concentrates on the metrological traceability of sensor networks for air quality monitoring to the international system of units (SI) based on FAIRified intra-network communications (M. Wilkinson, et al., “The FAIR guiding principles for scientific data management and stewardship,” Sci. Data, vol. 3, 2016, Art. no. 160018) and including delocalized Optical Gas Standards operated according to the digital TILSAM method (O. Werhahn, et al., The TILSAM Method Adapted into Optical Gas Standards – Complementing Gaseous Reference Materials, PTB Open Access Repository, 2021). Informed by related activities in EURAMET (Partnership project FunSNM, EMNs COO &amp; POLMO, TC-IM 1551) (European Metrology Network Climate and Ocean Observation (COO), European Metrology Network Pollution Monitoring (POLMO), EURAMET Project TC-IM 1551, Project Database) this contribution discusses the importance of measurement uncertainties in the context of sensor networks, comprising different sensor principles and promoting an efficient uptake of state-of-the-art methods. We discuss how the sensor network case can be addressed with sensors individually using the GUM principles (Joint Committee for Guides in Metrology, Guide to the Expression of Uncertainty in Measurement (GUM), JCGM 100: 2008 (E)). For sensor network measurements becoming metrologically traceable to the SI, documented and unbroken chains of calibrations need to be implemented each contributing to the measurement uncertainty. This applies to each individual sensor of the network including the potential gold standard among them, but also to the network’s output viewed as a single entity. The contribution provides first approaches to be tested and validated that are underpinned by fundamental design strategies for sensor networks. It follows on practical applications in real world scenarios aside from model uncertainties discussed in artificial intelligence prospects.

Reconstruct the unknown source on the right hand side of time fractional diffusion equation with Caputo-Hadamard derivative

The Caputo-Hadamard derivative was used to investigate the problem of functional recovery in this study. This problem is ill-posed, we propose a novel Quasi-reversibility for reconstructing the sought function and show that the regularization solution depends on space. After that, the convergence rates are established under a priori and posterior choice rules of regularization parameters, respectively.

Subthalamic DBS does not restore deficits in corticospinal suppression during movement preparation in Parkinson’s disease

ObjectiveParkinson’s disease (PD) patients exhibit changes in mechanisms underlying movement preparation, particularly the suppression of corticospinal excitability – termed “preparatory suppression” – which is thought to facilitate movement execution in healthy individuals. Deep brain stimulation (DBS) of the subthalamic nucleus (STN) being an attractive treatment for advanced PD, we aimed to study the potential contribution of this nucleus to PD-related changes in such corticospinal dynamics. MethodsOn two consecutive days, we applied single-pulse transcranial magnetic stimulation to the primary motor cortex of 20 advanced PD patients treated with bilateral STN-DBS (ON vs. OFF), as well as 20 healthy control subjects. Motor-evoked potentials (MEPs) were elicited at rest or during movement preparation in an instructed-delay choice reaction time task including left- or right-hand responses. Preparatory suppression was assessed by expressing MEPs during movement preparation relative to rest. ResultsPD patients exhibited a deficit in preparatory suppression when it was probed on the responding hand side, particularly when this corresponded to their most-affected hand, regardless of their STN-DBS status. ConclusionsAdvanced PD patients displayed a reduction in preparatory suppression which was not restored by STN-DBS. SignificanceThe current findings confirm that PD patients lack preparatory suppression, as previously reported. Yet, the fact that this deficit was not responsive to STN-DBS calls for future studies on the neural source of this regulatory mechanism during movement preparation.

Regularity of flat free boundaries for two-phase p(x)-Laplacian problems with right hand side

We consider viscosity solutions to two-phase free boundary problems for the p(x)-Laplacian with non-zero right hand side. We prove that flat free boundaries are C1,γ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$C^{1,\\gamma }$$\\end{document}. No assumption on the Lipschitz continuity of solutions is made. These regularity results are the first ones in literature for two-phase free boundary problems for the p(x)-Laplacian and also for two-phase problems for singular/degenerate operators with non-zero right hand side. They are new even when p(x)≡p\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$p(x)\\equiv p$$\\end{document}, i.e., for the p-Laplacian. The fact that our results hold for merely viscosity solutions allows a wide applicability.

Statistical evaluation of effect of anthropometric measurements on adolescent idiopathic scoliosis

Scoliosis is a deformity in which there is sideways curvature to the spine. Curves are often S shaped or C shaped. Most common type is the idiopathic type which occurs in 10-12 years of age and early teens, females are more affected than males while the body is growing fast and the curve is commonly to the right side of the body. It however affect all ages of about 3% of general population. This study was set out to evaluate statistically, the effect of age, gender and anthropometric measurements (such as height, weight and body mass index) to the curve formed using 51 patients from Lagos State University Teaching Hospital, Ikeja. It was discovered from the analysis that the ailment is common among females than males. The result also shows that the curve is most common to right hand side. The test of hypothesis conducted reveals that the anthropometric measurements of height, weight and body mass index though positively correlated with but do not have significant effect on the Adolescent Idiopathic Scoliosis curve.

On Solving a Quadratic Diophantine Equation Involving Odd Powers of 17

Diophantine Equations named after ancient Greek mathematician Diophantus, plays a vital role not only in number theory but also in several branches of science. In this paper, we will solve one of the quadratic Diophantine equations where the right hand side are odd positive integral powers of 17 and provide its complete solutions. The method adopted to solve the given equation is using the concept of polar form of a particular complex number. This concept can be generalized for solving similar equations.

Adaptive mesh based efficient approximations for Darcy scale precipitation–dissolution models in porous media

AbstractIn this work, we consider the Darcy scale precipitation–dissolution reactive transport 1D and 2D models in a porous medium and provide the adaptive mesh based numerical approximations for solving them efficiently. These models consist of a convection‐diffusion‐reaction PDE with reactions being described by an ODE having a nonlinear, discontinuous, possibly multi‐valued right hand side describing precipitate concentration. The bulk concentration in the aqueous phase develops fronts and the precipitate concentration is described by a free and time‐dependent moving boundary. The time adaptive moving mesh strategy, based on equidistribution principle in space and governed by a moving mesh PDE, is utilized and modified in the context of present problem for finite difference set up in 1D and finite element set up in 2D. Moreover, we use a predictor corrector based algorithm to solve the nonlinear precipitation–dissolution models. For equidistribution approach, we choose an adaptive monitor function and smooth it based on a diffusive mechanism. Numerical tests are performed to demonstrate the accuracy and efficiency of the proposed method by examples through finite difference approach for 1D and finite element approach in 2D. The moving mesh refinement accurately resolves the front location of Darcy scale precipitation–dissolution reactive transport model and reduces the computational cost in comparison to numerical simulations using a fixed mesh.

Survey on A Smart Medical System on Drug Analysis using ML Algorithms

Online health communities continue to offer huge variety of medical information useful for medical practitioners, system administrators and patients alike. In this system we collect real time health posts from reputed websites, where patients express their views, including their experiences and side-effects on drugs used by them. We propose to perform Summarization of user posts per drug, and come out with useful conclusions for medical fraternity as well as patient community at a glance. Further, we propose to classify the users based on their ‘emotional state of mind’. Also, we shall perform knowledge discovery from user posts, whereby useful ‘patterns’ about the triad ‘drugs-symptoms-medicine’ is done by Association Rule Mining. Association rule mining is a popular and widely-known machine learning task. It is used to find out interesting relations between variables in large database. Rules generated by association have two disjoint set of items having form LHS (Left Hand Side) =&gt; RHS (Right Hand Side). The rule says that RHS is likely to occur whenever the LHS set occurs.

Stability of solutions of systems of Volterra integral equations

In this paper, we propose new sufficient conditions for stability of solutions of systems of Volterra linear integral equations and systems of linear integro-differential Volterra equations. Solution stability conditions for systems of Volterra linear integral equations are studied with perturbed right hand sides of the equations. These new sufficient conditions are expressed in terms of logarithmic norms of matrices consisting of coefficients of equations and derivatives of their kernels. For Volterra integro-differential equations we also provide sufficient conditions for stability of solutions when the initial conditions are perturbed.

Generalized exponentially bounded integrated semigroups

The subject of this paper is the analysis of sequences of infinitesimal generators and exponentially bounded integrated semigroups which are related to Cauchy problems(1)∂∂tu(t,x)−a(D)u(t,x)=f(t,x),u(0,x)=u0(x),t≥0,x∈Rd, with distributional initial data u0 and distributional right hand sides f through sequences of equations with regularized u0 and f, and a(D) approximated by suitable sequences of (pseudo)differential operators an(D). Mainly, the paper deals with the comparison of sequences of infinitesimal generators and the determination of corresponding sequences of integrated semigroups. For this purpose, we introduce association, the relation of equivalence for infinitesimal generators on one side and the corresponding relations of equivalence of integrated semigroups on another side. The order of involved assumptions on generators essentially characterizes the mutual dependence of sequences of infinitesimal generators and the corresponding sequences of integrated semigroups. Our motivation is presented in Section 3 where we show how Cauchy problem (1) with certain type of singularities is transferred to a sequence of Cauchy problems with classical solutions presented by one time integrated semigroups, and then discuss the solution to (1) in a weak sense (in the sense of distributions) or a very weak sense (when only a sequence of solutions exists without a weak limit). The effects of perturbations of infinitesimal generators to integrated semigroups are the core of the paper.

On the coupling of Hamilton's principle and thermodynamic extremal principles

Extremal principles can generally be divided into two rather distinct classes. There are, on the one hand side, formulations based on the Lagrangian or Hamiltonian mechanics, respectively, dealing with time dependent problems, but essentially resting on conservation of energy and thus being not applicable to dissipative systems in a consistent way. On the other hand, there are formulations based essentially on maximizing the dissipation, working efficiently for the description of dissipative systems, but being not suitable for including inertia effects. Many attempts can be found in the literature to overcome this split into incompatible principles. However, essentially all of them possess an unnatural appearance. In this work, we suggest a solution to this dilemma resting on an additional assumption based on the thermodynamic driving forces involved. Applications to a simple dissipative structure and a material with varying mass demonstrate the capability of the proposed approach.

Simulation of heat transfer in Poiseuille pipe flow via generalized finite difference method with a space stepping algorithm

The aim of this paper is to propose an efficient numerical scheme to deal with heat transfer problems in pipe flow with a large length/diameter ratio. The generalized finite difference method (GFDM) is combined with a space stepping algorithm (SSA) for the solution. The SSA divides the solution domain into a number of overlapping sections in the length direction of the pipe. Due to the large Peclet number, the heat transport process is dominated by advection, which allows an approximate boundary condition to be applied at the downstream cross section. The problem is then solved section by section. Using the uniform distributed points, the solution matrix for each section does not change, and only the right hand side needs to be refreshed for the changing boundary conditions. This leads to a highly efficient scheme for problems with a large pipe length. To show the accuracy of the numerical scheme, a problem with available analytical solution is studied. Then the method is applied to problems of single pipe with different pipe wall temperature and flow Reynolds number, and concentric annular pipe. Numerical results confirm the stability and efficiency of the GFDM-SSA. The method can be applied to many real world transient heat transfer problems in which the pipe is heated or cooled along its length with arbitrary wall temperature for heat exchange and other purposes.