Initial state estimation from limited observations of the heat equation in metric graphs

This paper deals with initial state estimation problems of the heat equation in equilateral metric graphs being admitted to have cycles. Particularly, we are concerned with suitable placements of observation points in order to uniquely determine the initial state from observation data. We give a necessary and sufficient condition for suitable placements of observation points, and such suitable placements are determined from transition matrices of metric graphs. From numerical simulations, we confirm effectiveness of a necessary and sufficient condition.

Linear growth of the entanglement entropy for quadratic Hamiltonians and arbitrary initial states

We prove that the entanglement entropy of any pure initial state of a bipartite bosonic quantum system grows linearly in time with respect to the dynamics induced by any unstable quadratic Hamiltonian. The growth rate does not depend on the initial state and is equal to the sum of certain Lyapunov exponents of the corresponding classical dynamics. This paper generalizes the findings of [Bianchi et al., JHEP 2018, 25 (2018)], which proves the same result in the special case of Gaussian initial states. Our proof is based on a recent generalization of the strong subadditivity of the von Neumann entropy for bosonic quantum systems [De Palma et al., arXiv:2105.05627]. This technique allows us to extend our result to generic mixed initial states, with the squashed entanglement providing the right generalization of the entanglement entropy. We discuss several applications of our results to physical systems with (weakly) interacting Hamiltonians and periodically driven quantum systems, including certain quantum field theory models.

Experimental Review of ΛΛ¯ Production

Exclusive hyperon-antihyperon production provides a unique insight for understanding of the intrinsic dynamics when strangeness is involved. In this paper, we review the results of ΛΛ¯ production via different reactions from various experiments, e.g., via p¯p annihilation from the LEAR experiment PS185, via electron-positron annihilation using the energy scan method at the CLEO-c and BESIII experiments and the initial-state-radiation approach utilized at the BaBar experiment. The production cross section of ΛΛ¯ near the threshold is sensitive to QCD based prediction. Experimental high precision data for p¯p→Λ¯Λ close to the threshold region is obtained. The cross section of e+e−→ΛΛ¯ is measured from its production threshold to high energy. A non-zero cross section for e+e−→ΛΛ¯ near threshold is observed at BaBar and BESIII, which is in disagreement with the pQCD prediction. However, more precise data is needed to confirm this observation. Future experiments, utilizing p¯p reaction such as PANDA experiment or electron-positron annihilation such as the BESIII and BelleII experiments, are needed to extend the experimental data and to understand the ΛΛ¯ production.

Ultrafast manipulation of magnetic anisotropy in a uniaxial intermetallic heterostructure TbCo2/FeCo

We study experimentally and theoretically the dynamics of spin relaxation motion excited by a femtosecond pulse in the TbCo2/FeCo multilayer structures with different ratios of TbCo2 to FeCo thicknesses rd = dTbCo2 / dFeCo. The main attribute of the structure is in-plane magnetic anisotropy artificially induced during sputtering under DC magnetic field. The optical pump-probe method revealed strongly damped high-frequency oscillations of the dynamical Kerr rotation angle, followed by its slow relaxation to the initial state. Modeling experimental results using the Landau-Lifshitz-Gilbert (LLG) equation showed that the observed entire dynamics is due to destruction and restoration of magnetic anisotropy rather than to demagnetization. For the pumping fluence of 7 mJ/cm2, the maximal photo-induced disruption of the anisotropy field is about 14% for the sample with rd = 1 and decreases when rd increases. The anisotropy relaxation is a three-stage process: the ultrafast one occurs within several picoseconds, and the slow one occurs on a nanosecond time scale. The Gilbert damping in the multilayers is found one order of magnitude higher than that in the constituent monolayers.

Rhino Orbital Cerebral Mucormycosis in settings of Covid-19 infection: A Case Series of Thirteen Patients

Background Rhino-Orbital-Cerebral Mucormycosis (ROCM) is an important infectious disease encountered in huge number in this recent post-covid 19 era. An alteration in defence immune system during covid-19 illness, in the presence of uncontrolled hyperglycaemia has led to the new epidemic of ROCM especially in developing nations like India. Method This case series of thirteen patients illustrates the various clinical presentation, laboratorical parameters, imaging features and outcome of patients of ROCM admitted in a tertiary care hospital in Northern India. Result In our case series, a total of 13 newly diagnosed cases of Rhino-Orbital-Cerebral Mucormycosis were studied. History of covid-19 illness was observed in 7 cases (53.8%), use of steroid during Covid-19 illness was seen in 5 cases (38.5%), oxygen therapy was given in 4 cases (30.8%). Co-morbid state in the form of diabetes mellitus was present in 12 cases (92.3%) with mean duration 16.69 months with an important finding of 6 cases (46.2%) having new-onset diabetes; hypertension in present in 3 cases (23.1%). Magnetic resonance imaging of paranasal sinuses showed involvement of multiple sinuses in all the 13 cases(100%), including maxillary and ethmoidal sinuses, with frontal in 12 cases (92.3%), sphenoidal in 11 cases (84.6%), symmetric in 9 cases (69.2%), mastoiditis in 4 cases (30.8%), maxillary space involvement in 4 cases (30.8%), palatal involvement in 1 case (7.7%). Multi-speciality approach treatment was given in the liposomal amphotericin B therapy in all the patients along with thorough endo-nasal debridement done in all cases, transcutaneous retrobulbar amphotericin B in 6 cases (46.2%) with exenteration done in 7 patients (53.9%). At 3 months of follow-up, there was substantial clinical improvement in all the cases. Conclusion There should be definite emphasis on high suspicion of mucor clinically for early diagnosis and aggressive management at initial state of diagnosis for better outcome. The need for sustained proper glycemic control during covid 19 era along with judicious use of steroid and public awareness for early symptoms and manifestations of mucor can curb the magnitude of such potentially opportunistic epidemic to a substantial rate. The longer the infection remains undetected, the greater the devastation ROCM can impose, of which blindness is an important hazard.

Diagnosis and Treatment of Local Allergic Rhinitis

Some patients with chronic rhinitis have a positive nasal allergen provocation test (NAPT) without systemic IgE sensitization by skin prick tests or serum allergen-specific IgE (sIgE). This novel concept is called local allergic rhinitis (LAR) and affects children and adults worldwide, but is underdiagnosed. LAR is not just the initial state of allergic rhinitis (AR), it is a unique form of chronic rhinitis that is neither classical AR nor non-AR. Many of the features of AR and LAR are similar, such as a positive NAPT, positive type 2 inflammatory markers, including the nasal discharge of sIgE, and a high incidence of asthma. A differential diagnosis of LAR needs to be considered in patients with symptoms suggestive of AR in the absence of systemic atopy, regardless of age. The diagnostic method for LAR relies on positive responses to single or multiple allergens in NAPT, the sensitivity, specificity, and reproducibility of which are high. The basophil activation test and measurement of IgE in nasal secretions also contribute to the diagnosis of LAR. Treatment for LAR is similar to that for AR and is supported by the efficacy and safety of allergen exposure avoidance, drug therapy, and allergen immunotherapy. This review discusses current knowledge on LAR.

The Effect of Combined Processing on Residual Stresses in the Surface Layer of Power Plant Parts

The purpose of this research was to analyze the change in residual stresses in the surface layer of steel samples taking into account the technological heredity effect on the value and sign of residual stresses. An installation of combined processing was developed. Combined processing consists of sequentially performing electromechanical processing and diamond smoothing. All areas of the samples were studied—after machining (i.e., in the initial state), after electromechanical processing, and after diamond smoothing. The research shows that the sign and value of residual stresses are significantly affected by the combined processing modes. The main parameters of the surface layer are formed at the final stage of the combined processing–diamond smoothing. This paper gives recommendations on the use of combined processing for power plant parts.

Time-like Proton Form Factors with Initial State Radiation Technique

Electromagnetic form factors are fundamental quantities describing the internal structure of hadrons. They can be measured with scattering processes in the space-like region and annihilation processes in the time-like region. The two regions are connected by crossing symmetry. The measurements of the proton electromagnetic form factors in the time-like region using the initial state radiation technique are reviewed. Recent experimental studies have shown that initial state radiation processes at high luminosity electron-positron colliders can be effectively used to probe the electromagnetic structure of hadrons. The BABAR experiment at the B-factory PEP-II in Stanford and the BESIII experiment at BEPCII (an electron positron collider in the τ-charm mass region) in Beijing have measured the time-like form factors of the proton using the initial state radiation process e+e−→pp¯γ. The two kinematical regions where the photon is emitted from the initial state at small and large polar angles have been investigated. In the first case, the photon is in the region not covered by the detector acceptance and is not detected. The Born cross section and the proton effective form factor have been measured over a wide and continuous range of the the momentum transfer squared q2 from the threshold up to 42 (GeV/c)2. The ratio of electric and magnetic form factors of the proton has been also determined. In this report, the theoretical aspect and the experimental studies of the initial state radiation process e+e−→pp¯γ are described. The measurements of the Born cross section and the proton form factors obtained in these analyses near the threshold region and in the relatively large q2 region are examined. The experimental results are compared to the predictions from theory and models. Their impact on our understanding of the nucleon structure is discussed.

Discrete-Time Memristor Model for Enhancing Chaotic Complexity and Application in Secure Communication

The physical implementation of continuoustime memristor makes it widely used in chaotic circuits, whereas discrete-time memristor has not received much attention. In this paper, the backward-Euler method is used to discretize TiO2 memristor model, and the discretized model also meets the three fingerprinter characteristics of the generalized memristor. The short period phenomenon and uneven output distribution of one-dimensional chaotic systems affect their applications in some fields, so it is necessary to improve the dynamic characteristics of one-dimensional chaotic systems. In this paper, a two-dimensional discrete-time memristor model is obtained by linear coupling the proposed TiO2 memristor model and one-dimensional chaotic systems. Since the two-dimensional model has infinite fixed points, the stability of these fixed points depends on the coupling parameters and the initial state of the discrete TiO2 memristor model. Furthermore, the dynamic characteristics of one-dimensional chaotic systems can be enhanced by the proposed method. Finally, we apply the generated chaotic sequence to secure communication.

Modification of Biocorrosion and Cellular Response of Magnesium Alloy WE43 by Multiaxial Deformation

The study shows that multiaxial deformation (MAD) treatment leads to grain refinement in magnesium alloy WE43. Compared to the initial state, the MAD-processed alloy exhibited smoother biocorrosion dynamics in a fetal bovine serum and in a complete cell growth medium. Examination by microCT demonstrated retardation of the decline in the alloy volume and the Hounsfield unit values. An attendant reduction in the rate of accumulation of the biodegradation products in the immersion medium, a less pronounced alkalization, and inhibited sedimentation of biodegradation products on the surface of the alloy were observed after MAD. These effects were accompanied with an increase in the osteogenic mesenchymal stromal cell viability on the alloy surface and in a medium containing their extracts. It is expected that the more orderly dynamics of biodegradation of the WE43 alloy after MAD and the stimulation of cell colonization will effectively promote stable osteosynthesis, making repeat implant extraction surgeries unnecessary.