Classical Level Research Articles

A comparison of the clinical efficacy of GON block at the C2 level and GON block at the classical distal occipital level in the treatment of migraine

PurposeThe aim of this retrospective study was to compare the efficacy and complications of ultrasound-guided block (C2GON) at the level of C2 and block performed from the distal occiput level (DOGON) as the greater occipital nerve progresses superficially to the obliquus capitis inferior muscle in migraine patients. Methods63 patients were included in this retrospective study. For C2GON blockade, 2 units of 4 ml 0.5% bupivacaine were prepared for bilateral administration to 32 patients. For DOGON, two 1.5 ml 0.5% bupivacaine was prepared bilaterally for each patient. The patients were evaluated in terms of pain intensity and frequency, analgesic use, and any side effects before the injection and at the 1st and 3rd months after the last treatment. ResultsWhen we compared C2GON block and DOGON block in our study, we found that both blocks were effective for 3 months. The reduction rates in the C2GON and DOGON groups were 75.3% and 59% in the number of severe attacks, 63.9% and 59.1% in the total analgesic use, 71.1% and 56.25% in the triptan use, 78% and 60% in the number of days with severe headache, 63.4% and 50.3% in the duration of headache. The decrease in the highest VAS score was 48.1% in the group with C2GON, while it was 53% in the group with DOGON. ConclusionsCurrent findings have shown that both C2GON and DOGON blockades are effective in the treatment of migraine for 3 months.

Protection of qubits by nonlinear resonances

We show that quantized superconducting circuits are non-integrable at the classical level of description, adorned by nonlinear resonances amidst stochastic sea. The stable (elliptic) and unstable (hyperbolic) points occur in a way that by choosing the parameters of a system close to elliptic points, the dynamics is stable. Quantum mechanically, any disturbance has to tunnel the separatrix to reach the elliptic point. Thus, nonlinearity of the system provides protection. Based on these fundamental considerations from the Kolmogorov–Arnold–Moser theorem, we propose criteria for protection of qubits from any disturbance.

Effective description of non-equilibrium currents in cold magnetized plasma

The dynamics of cold strongly magnetized plasma -- traditionally the domain of force-free electrodynamics -- has recently been reformulated in terms of symmetries and effective field theory, where the degrees of freedom are the momentum and magnetic flux carried by a fluid of cold strings. In physical applications where the electron mass can be neglected one might expect the presence of extra light charged modes -- electrons in the lowest Landau level -- propagating parallel to the magnetic field lines. We construct an effective description of such electric charges, describing their interaction with plasma degrees of freedom in terms of a new collective mode that can be thought of as a bosonization of the electric charge density along each field line. In this framework QED phenomena such as charged pair production and the axial anomaly are described at the classical level. Formally, our construction corresponds to gauging a particular part of the higher form symmetry associated with magnetic flux conservation. We study some simple applications of our effective theory, showing that the scattering of magnetosonic modes generically creates particles and that the rotating Michel monopole is now surrounded by a cloud of electric charge.

Dualization between supersymmetric self-dual and topologically massive models coupled to matter in four-dimensional superspace

Using the superfield formalism and the master action approach, we prove, both at the classical and quantum levels, the dual equivalence between four-dimensional supersymmetric self-dual and topologically massive models coupled to dynamical matter.

A massively parallel accurate conservative level set algorithm for simulating turbulent atomization on adaptive unstructured grids

This article presents a massively parallel and robust strategy to perform the simulation of turbulent incompressible two-phase flows on unstructured grids in complex geometries. This strategy relies on a combination of a narrow-band accurate conservative level set (ACLS)/ghost-fluid framework with isotropic adaptive mesh refinement. This combination enables to accurately capture interface dynamics and topology, and the small physical scales at the liquid-gas interface are resolved at an affordable cost. The ACLS method, even if not strictly mass-conserving, ensures the exact conservation of a smoothed phase indicator, which minimizes the liquid mass conservation errors. In the accurate conservative level set framework, presented first in Desjardins et al. (2008) [25], the interface is defined as the iso-contour of a hyperbolic tangent function, which is advected by the fluid, and then reshaped using a reinitialization equation. Several forms of this reinitialization exist: the original ACLS form proposed by Desjardins et al. involves numerical estimation of the hyperbolic tangent gradient, which is difficult to compute accurately on unstructured meshes. It is thus susceptible to induce artificial deformation of the interface. A new form has been recently proposed in Chiodi and Desjardins (2017) [29], which takes advantage of a mapping onto a classical distance level set while much better preserving the interface shape. Nevertheless, the implementation of this new form on unstructured grids requires special care. In this work, a robust implementation of this new form on unstructured meshes is proposed and implemented in the YALES2 low-Mach flow solver. In order to compute interface normals and curvature, the signed-distance function is reconstructed in parallel at nodes in the narrow band around the interface using a Geometric-Projection Marker Method (GPMM). This method relies on the triangulation of the level set iso-contour and exact geometric projection to the closest surface elements. Spatial convergence, robustness and efficiency of the overall procedure are firstly demonstrated through classical interface transport test cases and two-phase flow examples. Eventually, to emphasize the significant computational gain using adaptive mesh refinement and the ability to compute complex turbulent flows with large density ratios, two Large-Eddy Simulations (LES) of atomizing liquid jets in air are presented, each one at various resolutions. The first one is a low-pressure water jet in quiescent air from a compound nozzle with full computation of the internal injector flow, while the latter is a high-pressure kerosene jet in crossflow. Both simulations are validated against experiments, demonstrating the potential of the method to access a deep numerical insight into jet instabilities and internal flow dynamics with 3D unstructured meshes.

The Birth of the Universe as a Result of the Change of the Metric Signature

In this paper, I discuss the idea that the birth of our Universe may be a result of a quantum transition from a physical continuum with the Euclidean signature to a Lorentzian spacetime. A similar idea was expressed by Andrei D. Sakharov At the classical level, the idea was studied by George F. R. Ellis and his collaborators, who explored if solutions to the classical Einstein equation exist which admit a change of metric signature. The present paper aims at examining possible realizations of this idea at the level of quantum gravity, in the framework of the Wheeler–DeWitt theory and in the extended phase space approach to quantization of gravity. I intend to answer the questions: to answer the questions: Does the Hartle–Hawking wave function imply such a realization? How can this idea be realized in the extended phase space approach to quantum gravity, where the change of signature is described by imposing special conditions on g00-component of the metric in different regions of the physical continuum? The conclusion is that the idea can be realized from a formal mathematical point of view, but it can hardly help in understanding how spacetime structure and time itself appeared from a timeless continuum.

Holographic RG flow triggered by a classically marginal operator

We study the holographic renormalization group (RG) flow triggered by a classically marginal operator. When a marginal operator deforms a conformal field theory, it does not yield a nontrivial renormalization group flow at the classical level. At the quantum level, however, quantum corrections modify a marginal operator into one of the truly marginal, marginally relevant, and marginally irrelevant operators and can generate a nontrivial RG flow. We investigate the holographic description of a RG flow triggered by a marginal operator with quantum corrections. We look into how the physical quantities of a deformed theory, a coupling constant and the vacuum expectation value, rely on the RG scale. We further discuss the holographic description of the trace anomaly caused by the gluon condensation.

UPAYA MENINGKATKAN KEMAMPUAN MENULIS LAPORAN PENGAMATAN DALAM PELAJARAN BAHASA INDONESIA MELALUI PEMBELAJARAN KONTEKSTUAL BAGI SISWA KELAS V SDN 5 SUKAWARGI

This study aims to determine (1) students' writing skills before using contextual learning models, (2) students' writing abilities after using contextual learning models, (3) student responses in using contextual learning models. This type of research is Classroom Action Research (CAR) with research subjects in class V SDN 5 Sukawargi consisting of 20 students. Based on the results of the study it can be concluded that. (1) students' writing skills before using the contextual learning model, that is, 3 students who complete or with a percentage of 15%. (2) students' writing abilities after using the contextual learning model, namely in the first cycle of students who completed 9 people or with a percentage of 45%. Furthermore, in cycle II, 16 students who passed or a percentage of 80% completed. To be more convincing, 20 students complete the third cycle with a percentage of 100%. This shows that the ability of students in writing observation reports has reached a classical level of 100% completeness learning. (3) student responses using contextual learning models in learning Indonesian are positive. Thus that using contextual learning models can improve students' ability to write observation reports.

PENERAPAN MODEL PEMBELAJARAN KOOPERATIF THINK-PAIR-SHARE TERHADAP KETERAMPILAN BERPIKIR KRITIS DAN HASIL BELAJAR PESERTA DIDIK PADA KONSEP KINGDOM PLANTAE DI SMA NEGERI 5 BANDA ACEH

This study aims to improve the quality of biology learning process through think- Pair-Share (TPS) models, to improve student learning Outcomes, to describe teachers and student learning activities, and to determine the learning completeness level. The population of this study was 324 students of grade X. The sample was 20 students for the experiment class from class I5 and 20 students for the control class. The sample selected was based on a lottery system. The instrument in this study was a test. The data gathered was analyzed with a t-test. The result showed that the implementation of TPS on the Plantae concept can improve student learning outcomes. The learning process activities were well concluded. The dominant activity of teachers was as a facilitator while the dominant activity of students was doing on student worksheets in pairs. At the classical level as learning competency, The experiment class reached 80 % and the control class reached 60 % of a 100.

UPAYA MENINGKATKAN HASIL BELAJAR PESERTA DIDIK DENGAN MENGGUNAKAN MODEL DISCOVERY LEARNING

Jenis penelitian ini adalah Penelitian Tindakan Kelas (PTK). Dengan menggunakan model Discovery Learning pada mata pelajaran tematik tema Praja Muda Karana subtema 4 pembelajaran 1 dan pembelajaran 3 di kelas III SD Negeri 104186 Tanjung Selamat Kecamatan Sunggal Tahun Pembelajaran 2020/2021 dapat meningkatkan hasil belajar siswa. Halini dapat dilihat pada hasil belajar yang diperoleh siswa secara individu yaitu pada prasiklus dengan nilai rata-rata 50.93% pada siklus I meningkat dengan nilai rata-rata 61.13% selanjutnya pada siklus II nilai rata-rata diperoleh sebesar 83.3%. Hal ini menunjukkan bahwa pada siklus I sampai siklus II mengalami peningkatan.Pelaksanaan pembelajaran dengan menggunakan model Discovery Learning pada mata pelajaran tematik tema Praja Muda Karana subtema 4 pembelajaran 1 dan pembelajaran 3 di kelas III SD Negeri 104186 Tanjung Selamat Kecamatan Sunggal Tahun Pembelajaran 2020/2021 dikategorikan sudah baik. Hal ini dapat dilihat dari hasil observasi aktivitas siswa pada siklus I diperoleh sebanyak 55% kategori cukup dan pada siklus II meningkat menjadi 93% kategori sangat baik.

UPAYA MENINGKATKAN HASIL BELAJAR SISWA DENGAN MENGGUNAKAN MODEL PEMBELAJARAN INSIDE OUTSIDE CIRCLE (IOC) PADA SISWA KELAS IV SD

Jenis penelitian yang digunakan adalah penelitian tindakan kelas (PTK). Penelitian ini bertujuan untuk meningkatkan hasil belajar siswa pada tema daerah tempat tinggalku dengan menggunakan pembelajaran Inside Outside Circle (IOC) di kelas IV SD Negeri 044857 Mardingding Kecamatan Mardingding. Hasil penelitian ini menunjukan adanya peningkatan hasil belajar peserta didik. Pada pretes diperoleh bahwa nilai rata-rata 62.95 dan tingkat ketuntasan secara klasikal sebesar 22.22%. Pada siklus I mengalami peningkatan setelah menggunakan model pembelajaran Inside Outside Circle (IOC) dengan nilai rata-rata 71.95 dan tingkat ketuntasan secara klasikal sebesar 40.74%. Dan setelah tindakan yang dilakukan dan diberikan postes siklus II maka diperoleh sebanyak 27siswa yang tuntas hasil belajarnya dan 6 orang siswa yang tidak tuntas dengan nilai rata-rata posttes siklus II meningkat meningkat menjadi 81.97 dan tingkat ketuntasan klasikal mencapai 84.61%. Dari hasil yang diperoleh dan disimpulkan bahwa model Inside Outside Circle (IOC) dapat meningkatkan hasil belajar siswa di kelas IV SD Negeri 044857 Mardingding Tahun Pembelajaran 2020/2021. Berdasarkan hasil penelitian, maka guru disarankan untuk menggunakan model Inside Outside Circle (IOC) karena terbukti dapat meningkatkan hasil belajar siswa.

Online Class Resitation Learning Model During the Covid-19 Pandemic to Increase Outcomes Students Learning in Class Accounting Lessons

This study aims to determine the improvement of student learning outcomes through the online class recitation learning model during the covid-19 pandemic, on the learning process of class X1 students of the Accounting Department at SMK Negeri 1 Tompaso Baru Minahasa, totaling 14 students. The online classroom research method used is in the form of CAR (Classroom Action Research) which refers to classroom action research. In terms of treatment, learning is given that applies an online class recitation learning model.
 From the results of the analysis obtained by researchers on accounting subjects with service company accounting cycle material with the stages: Recording transactions/documents into general journals (General Entries) and posting from general journals to general ledgers (General Ledger), there is an increase in student learning outcomes. This increase can be seen from the percentage of student learning completeness individually and classically. This increase can be seen from the percentage of student learning completeness individually and classically. At the pre-cycle stage or before the implementation of the action, the average value of the class was 63.92 with the percentage of classical learning completeness only 35%. In the first cycle, it reached an average of 71.78 with a classical mastery level of 64.28%. While the learning outcomes in the second cycle reached an average of 77.85 with the classical learning completeness level reaching 92.85%. Likewise with student learning activities at every face-to-face online class. Student activity at the 1st meeting only reached a percentage of 56.25% with high criteria. At the second meeting it reached a percentage of 72.76% with high criteria, and at the third meeting it reached a percentage of 83.92% with very high criteria. Thus, student learning activities and student learning completeness in online classes during the COVID-19 pandemic increase by using the online class recitation learning model. With learning outcomes reaching 92.85% above the minimum learning completeness.

Phase diagram of a distorted kagome antiferromagnet and application to Y-kapellasite

We investigate the magnetism of a previously unexplored distorted spin-1/2 kagome model consisting of three symmetry-inequivalent nearest-neighbor antiferromagnetic Heisenberg couplings J⬡, J, and J^{prime}, and uncover a rich ground state phase diagram even at the classical level. Using analytical arguments and numerical techniques we identify a collinear overrightarrow{Q}=0 magnetic phase, two unusual non-collinear coplanar overrightarrow{Q}=(1/3,1/3) phases and a classical spin liquid phase with a degenerate manifold of non-coplanar ground states, resembling the jammed spin liquid phase found in the context of a bond-disordered kagome antiferromagnet. We further show with density functional theory calculations that the recently synthesized Y-kapellasite Y3Cu9(OH)19Cl8 is a realization of this model and predict its ground state to lie in the region of overrightarrow{Q}=(1/3,1/3) order, which remains stable even after the inclusion of quantum fluctuation effects within variational Monte Carlo and pseudofermion functional renormalization group. The presented model opens a new direction in the study of kagome antiferromagnets.

HCV co-infection is related to acute ischemic severity and outcome

Background and aimHCV infection is associated with increased risk of ischemic cerebral stroke. HCV stroked patients are younger with a lower burden of classical risk factors and higher levels of systemic inflammation. The present study aimed to discover the association between HCV infection functional outcome of stroke.Patients and methodsThe present prospective study included 60 patients with acute ischemic stroke. All patients were subjected to careful history taking and through clinical and neurological examination. Stroke severity at presentation was assessed using National Institute of Health Stroke Scale (NIHSS). Quantitative HCV RNA test was used to diagnose HCV infection. The prognosis of the studied patients was 3 months after treatment using modified Rankin scale (mRS) for neurologic disability.ResultsThe present study was conducted on 60 patients with ischemic stroke. They comprised 13 patients (21.7%) with HCV and 47 patients without. Stroke patients with HCV had significantly higher frequency of carotid artery stenosis, higher NIHSS (17.9 ± 6.9 versus 9.9 ± 5.3, p < 0.001) and higher frequency of severe stroke (46.1% versus 4.3%, p = 0.001) when compared with patients without HCV. Logistic regression analysis identified patients’ sex, NIHSS and HCV as significant predictors of outcome in univariate analysis. However, in multivariate analysis, only NIHSS proved to be significant.ConclusionsThe present study suggests a significant link between chronic HCV infection and ischemic stroke severity and poor outcome. This is probably related to the pathogenic effects of the chronic inflammatory state induced by HCV infection on the cerebral microvasculature.

Suppression of toroidal Alfvén eigenmodes by the electron cyclotron current drive in KSTAR plasmas

Advanced operation scenarios such as high poloidal beta (β P) or high q min are promising concepts to achieve the steady-state high-performance fusion plasmas. However, those scenarios are prone to substantial Alfvénic activity, causing fast-ion transport and losses. Recent experiments with the advanced operation scenario on KSTAR tokamak have shown that the electron cyclotron current drive (ECCD) is able to mitigate and suppress the beam-ion driven toroidal Alfvén eigenmodes (TAEs) for over several tens of global energy confinement time. Co-current directional intermediate off-axis ECCD lowers the central safety factor slightly and tilts the central q-profile shape so that the continuum damping in the core region increases. Besides, the rise of central plasma pressure and increased thermal-ion Landau damping contribute to TAE stabilization. While the TAEs are suppressed, neutron emission rate and total stored energy increase by approximately 45% and 25%, respectively. Fast-ion transport estimated by TRANSP calculations approaches the classical level during the TAE suppression period. Substantial reduction in fast-ion loss and neutron deficit is also observed. Enhancement of fast-ion confinement by suppressing the TAEs leads to an increase of non-inductive current fraction and will benefit the sustainment of the long-pulse high-performance discharges.

On the propagation across the big bounce in an open quantum FLRW cosmology

The propagation of a scalar field in an open FLRW bounce-type quantum spacetime is examined, which arises within the framework of the IKKT matrix theory. In the first part of the paper, we employ general-relativity tools to study null and timelike geodesics at the classical level. This analysis reveals that massless and massive non-interacting particles can travel across the big bounce. We then exploit quantum-field-theory techniques to evaluate the scalar field propagator. In the late-time regime, we find that it resembles the standard Feynman propagator of flat Minkowski space, whereas for early times it governs the propagation across the big bounce and gives rise to a well-defined correlation between two points on opposite sheets of the spacetime.

Scale invariance and dilaton mass

We consider a generic scale invariant scalar quantum field theory and its symmetry breakdown. Based on the dimension counting identity, we give a concise proof that dilaton is exactly massless at the classical level if scale invariance is broken spontaneously. On the other hand, on the basis of the generalized dimension counting identity, we prove that the dilaton becomes massive at the quantum level if scale invariance is explicitly broken by quantum anomaly. It is pointed out that a subtlety occurs when scale invariance is spontaneously broken through a scale invariant regularization method where the renormalization scale is replaced with the dilaton field. In this case, the dilaton remains massless even at the quantum level after spontaneous symmetry breakdown of scale symmetry, but when the massless dilaton couples non-minimally to the Einstein-Hilbert term and is applied for cosmology, it is phenomenologically ruled out by solar system tests unless its coupling to matters is much suppressed compared to the gravitational interaction.

Liouville conformal field theory on even-dimensional spheres

Initiated by Polyakov in his 1981 seminal work, the study of two-dimensional Liouville conformal field theory has drawn considerable attention over the past few decades. Recent progress in the understanding of conformal geometry in dimension higher than two has naturally led to a generalization of the Polyakov formalism to higher dimensions based on conformally invariant operators: Graham–Jenne–Mason–Sparling operators and the Q-curvature. This article is dedicated to providing a rigorous construction of Liouville conformal field theory on even-dimensional spheres. This is done at the classical level in terms of a generalized uniformization problem and at the quantum level, thanks to a probabilistic construction based on log-correlated fields and Gaussian multiplicative chaos. The properties of the objects thus defined are in agreement with the ones expected in the physics literature.

A Stellar Constraint on Eddington-inspired Born–Infeld Gravity from Cataclysmic Variable Binaries

Abstract Eddington-inspired Born–Infeld gravity is an important modification of Einstein’s general relativity, which can give rise to nonsingular cosmologies at the classical level, and avoid the end-stage singularity in a gravitational collapse process. In the Newtonian limit, this theory gives rise to a modified Poisson’s equation, as a consequence of which stellar observables acquire model dependent corrections, compared to the ones computed in the low energy limit of general relativity. This can in turn be used to establish astrophysical constraints on the theory. Here, we obtain such a constraint using observational data from cataclysmic variable binaries. In particular, we consider the tidal disruption limit of the secondary star by a white dwarf primary. The Roche lobe filling condition of this secondary star is used to compute stellar observables in the modified gravity theory in a numerical scheme. These are then contrasted with the values obtained by using available data on these objects, via a Monte Carlo error progression method. This way, we are able to constrain the theory within the 5σ confidence level.

Dynamics, symmetries, anomaly and vortices in a rotating cosmic string background

Non-relativistic conformally invariant systems in a rotating cosmic string (conical) spacetime are analyzed at the classical and quantum levels by means of the gravitoelectromagnetic interpretation of the background. Solutions of the equations of motion are found by employing a local canonical transformation, that leads to their natural interpretation in terms of Riemann surfaces. The cone parameter α and the angular velocity Ω of the background determine the existence of hidden symmetries. Globally defined higher order integrals associated with perihelion of geodesic orbits appear at rational values of α. For the harmonic oscillator system with frequency ω, the integrals responsible for the trajectory closure arise only for rational values of α and |γ| = |Ω/ω|, with |γ| = 1 corresponding to the Landau problem. We face a quantum anomaly problem since the hidden symmetry operators can only be constructed when α is integer. Such operators are non-local in the case of the free particle. For the harmonic oscillator, the symmetry generators are obtained with the help of the conformal bridge transformation. We also study a multi-particle version of the harmonic oscillator system with |γ| = 1 using the mean-field theory and find that the emerging vortex structure respects a singular point of the background.