Letter from the Editor-in-Chief

Welcome to the second volume of Recent Advances in Pathology and Laboratory Medicine! I hope RAPL becomes an essential part of your professional life, a resource that offers you a steady supply of high-quality, peer reviewed papers that are relevant and informative.We are over whelmed with the number of papers we receive at the editorial desk and at the same time grateful to our readers for the feedback and hope that all the work including the articles chosen for this issue, demonstrates our desire to engage more broadly and highlight the advances in the field of medicine

Spin dynamics and frequency dependence of magnetic damping study in soft ferromagnetic FeTaC film with a stripe domain structure

Perpendicular magnetic anisotropy (PMA) and low magnetic damping are the key factors for the free layer magnetization switching by spin transfer torque technique in magnetic tunnel junction devices. The magnetization precessional dynamics in soft ferromagnetic FeTaC thin film with a stripe domain structure was explored in broad band frequency range by employing micro-strip ferromagnetic resonance technique. The polar angular variation of resonance field and linewidth at different frequencies have been analyzed numerically using Landau-Lifshitz-Gilbert equation by taking into account the total free energy density of the film. The numerically estimated parameters Land\'{e} $g$-factor, PMA constant, and effective magnetization are found to be 2.1, 2$\times10^{5}$ erg/cm$^{3}$ and 7145 Oe, respectively. The frequency dependence of Gilbert damping parameter ($\alpha$) is evaluated by considering both intrinsic and extrinsic effects into the total linewidth analysis. The value of $\alpha$ is found to be 0.006 at 10 GHz and it increases with decreasing precessional frequency.Comment: 5 Pages, 6 Figures, Regular Submissio

Half Cycle Pulse Train Induced State Redistribution of Rydberg Atoms

Population transfer between low lying Rydberg states independent of the initial state is realized using a train of half-cycle pulses with pulse durations much less than the classical orbit period. We demonstrate experimentally the transfer of population from initial states around n=50 down to n<40 as well as up to the continuum. The measured population transfer matches well to a model of the process for 1D atoms.Comment: V2: discussion extended, version accepted for publication in Physical Review

Critical behavior at de-pinning of a driven disordered vortex matter in 2H-NbS2

We report unusual jamming in driven ordered vortex flow in 2H-NbS2. Reinitiating movement in these jammed vortices with a higher driving force, and halting it thereafter once again with a reduction in drive, unfolds a critical behavior centered around the de-pinning threshold via divergences in the lifetimes of transient states, validating the predictions of a recent simulation study, which also pointed out a correspondence between plastic de-pinning in vortex matter and the notion of random organization proposed in the context of sheared colloids undergoing diffusive motion.Comment: Phys. Rev. B (in press, 2012). The paper has 14 pages of Text+ Refs. with 4 figures. (Note as some of the figure files are large in size, to enable faster download, the file size has been kept small and the figure resolution are low. The online version of the paper to appear in PRB will contain the higher resolution figures

Sunspot area catalogue revisited: Daily cross-calibrated areas since 1874

Long and consistent sunspot area records are important for understanding the long-term solar activity and variability. Multiple observatories around the globe have regularly recorded sunspot areas, but such individual records only cover restricted periods of time. Furthermore, there are also systematic differences between them, so that these records need to be cross-calibrated before they can be reliably used for further studies. We produce a cross-calibrated and homogeneous record of total daily sunspot areas, both projected and corrected, covering the period between 1874 and 2019. A catalogue of calibrated individual group areas is also generated for the same period. We have compared the data from nine archives: Royal Greenwich Observatory (RGO), Kislovodsk, Pulkovo, Debrecen, Kodaikanal, Solar Optical Observing Network (SOON), Rome, Catania, and Yunnan Observatories, covering the period between 1874 and 2019. Mutual comparisons of the individual records have been employed to produce homogeneous and inter-calibrated records of daily projected and corrected areas. As in earlier studies, the basis of the composite is formed by the data from RGO. After 1976, the only datasets used are those from Kislovodsk, Pulkovo and Debrecen observatories. This choice was made based on the temporal coverage and the quality of the data. In contrast to the SOON data used in previous area composites for the post-RGO period, the properties of the data from Kislovodsk and Pulkovo are very similar to those from the RGO series. They also directly overlap the RGO data in time, which makes their cross-calibration with RGO much more reliable. We have also computed and provide the daily Photometric Sunspot Index (PSI) widely used, e.g., in empirical reconstructions of solar irradiance.Comment: Accepted for publication in Astronomy and Astrophysics. An additional file (animation) is available at https://www.dropbox.com/s/armawopcxt8kmb9/Mandal_2020_butterfly_diagram.zip?dl=