CONSIDERATIONS ON THE ISSUE OF COMBINED INJURIES

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Implementing a Web-based Application for Analysis and Evaluation of Heart Rate Variability Using Serverless Architecture

This article is devoted to the development of a web-based application for analysis and evaluation of Heart Rate Variability (HRV) using serverless architecture. Advancements in information algorithms and computing technologies have been playing an increasingly important role in cardiology, as continuous monitoring of patients’ health can be vital to their well-being.  One physiological parameter that can be easily measured and that can provide indispensable insight into the state of the human body is the HRV.  HRV analysis can assess not only the physiological state of the body but also provide the capability to monitor its dynamics and predict future diseases. As the research in the sphere of cardiology is constantly growing there is a multitude of new ways to assess the physiological state of patients and provide an early indicator to pathological conditions. Therefore, there is a need to bring these advances to a growing number of end-users (health-care professionals and patients) in the shortest possible time. To address this problem, this study proposes the development of a web-based application for analysis and evaluation of HRV by applying linear and nonlinear mathematical methods. The application is created using a serverless architectural approach, which allows for fast development time, as there is no need to manage server infrastructure, and for automatic scaling to dynamically match the number of requests. The developer can instead focus on implementing the logic for the HRV analysis algorithms and deliver new improvements at a faster rate. The proposed web application can be accessed by any device that is connected to the Internet and is optimized to handle both an intermittent and a consistent volume of requests. The algorithms implemented in the web application have been validated by examining two groups of subjects (young adults and older adults) using linear and non-linear models. The obtained results from the two groups can be compared with a set of reference values (only for the linear methods) and an assessment can be made whether each studied parameter is within the normal range or outside it (its value is too high or too low). To aid the assessment for HRV, the results obtained by the linear and nonlinear analysis are presented using a set of both graphs and tables

Novel Field-Induced Phases in HoMnO3 at Low Temperatures

The novel field-induced re-entrant phase in multiferroic hexagonal HoMnO3 is investigated to lower temperatures by dc magnetization, ac susceptibility, and specific heat measurements at various magnetic fields. Two new phases have been unambiguously identified below the Neel transition temperature, TN=76 K, for magnetic fields up to 50 kOe. The existence of an intermediate phase between the P[6]_3[c]m and P[6]_3c[m] magnetic structures (previously predicted from dielectric measurements) was confirmed and the magnetic properties of this phase have been investigated. At low temperatures (T<5 K) a dome shaped phase boundary characterized by a magnetization jump and a narrow heat capacity peak was detected between the magnetic fields of 5 kOe and 18 kOe. The transition across this phase boundary is of first order and the magnetization and entropy jumps obey the magnetic analogue of the Clausius-Clapeyron relation. Four of the five low-temperature phases coexist at a tetracritical point at 2 K and 18 kOe. The complex magnetic phase diagram so derived provides an informative basis for unraveling the underlying driving forces for the occurrence of the various phases and the coupling between the different orders.Comment: 14 pages, 14 figure

Fingerprints of Inelastic Transport at the Surface of the Topological Insulator Bi2Se3: Role of Electron-Phonon Coupling

We report on electric-field and temperature dependent transport measurements in exfoliated thin crystals of Bi$_{2}$Se$_{3}$ topological insulator. At low temperatures ($< 50$ K) and when the chemical potential lies inside the bulk gap, the crystal resistivity is strongly temperature dependent, reflecting inelastic scattering due to the thermal activation of optical phonons. A linear increase of the current with voltage is obtained up to a threshold value at which current saturation takes place. We show that the activated behavior, the voltage threshold and the saturation current can all be quantitatively explained by considering a single optical phonon mode with energy $\hbar \Omega \approx 8$ meV. This phonon mode strongly interacts with the surface states of the material and represents the dominant source of scattering at the surface at high electric fields.Comment: Supplementary Material at: http://journals.aps.org/prl/supplemental/10.1103/PhysRevLett.112.086601/TIPhonon_SM.pd

A Field-Induced Re-Entrant Novel Phase and A Ferroelectric-Magnetic Order Coupling in HoMnO3

A re-entrant novel phase has been observed in the hexagonal ferroelectric HoMnO3 in the presence of magnetic fields, in the temperature ranges defined by the plateau of the dielectric constant anomaly. The dielectric plateau evolves with fields from a narrow sharp dielectric peak at the Mn-spin rotation transition at 32.8 K in zero magnetic field. Such a field-induced dielectric plateau anomaly appears both in the temperature sweep at a constant field and in the field sweep at a constant temperature without detectable hysteresis. This is attributed to the indirect coupling between the ferroelectric and antiferromagnetic orders, arising from an antiferromagnetic domain wall effect, where the magnetic order parameter of the Mn subsystem has to change sign across the ferroelectric domain wall in the compound, that influences the ferroelectric domains via a local magnetostrictive effect

Magnetic frustration in an iron based Cairo pentagonal lattice

The Fe3+ lattice in the Bi2Fe4O9 compound is found to materialize the first analogue of a magnetic pentagonal lattice. Due to its odd number of bonds per elemental brick, this lattice, subject to first neighbor antiferromagnetic interactions, is prone to geometric frustration. The Bi2Fe4O9 magnetic properties have been investigated by macroscopic magnetic measurements and neutron diffraction. The observed non-collinear magnetic arrangement is related to the one stabilized on a perfect tiling as obtained from a mean field analysis with direct space magnetic configurations calculations. The peculiarity of this structure arises from the complex connectivity of the pentagonal lattice, a novel feature compared to the well-known case of triangle-based lattices