Variation of Entanglement Entropy in Scattering Process

In a scattering process, the final state is determined by an initial state and an S-matrix. We focus on two-particle scattering processes and consider the entanglement between these particles. For two types initial states; i.e., an unentangled state and an entangled one, we calculate perturbatively the change of entanglement entropy from the initial state to the final one. Then we show a few examples in a field theory and in quantum mechanics.Comment: 13 pages; v2: refs. adde

Application of OSCE using a Virtual Assessment Platform

Introduction: This study describes the development and implementation of a virtual objective structured clinical examination (OSCE) at the Harvard School of Dental Medicine (HSDM) as an alternative to in-person OSCEs during the COVID-19 pandemic and evaluates its efficacy and reception by students and faculty.Methods: The virtual OSCE was conducted over Zoom (Zoom Video Communications, Inc. San Jose, CA) with students rotating through each discipline via Breakout Rooms. This study examined all 241 OSCE results from the HSDM classes of 2016-2022, with 170 in-person OSCE results and 71 virtual OSCE results. Descriptive and linear regression analysis were used to report the difference in OSCE experience and scores between virtual and in-person OSCEs.Results: Out of 100, the adjusted average score difference was 0.66 higher in virtual OSCE experience compared to in-person assessment, but it was not statistically significant (95%CI=-0.45, 1.78). A total of 35 students (49%) and 14 faculty responded to a survey regarding their virtual OSCE experience. Most students surveyed agreed that the virtual OSCE was effective (94%), accessible (97%), and should be offered post-pandemic (74%). The majority of faculty were neutral regarding the virtual OSCE as a comparable learning experience (76%) and in its accessibility (71%), and only 14% agreed that virtual OSCE should be offered in the future.Conclusion: The results show that the virtual OSCE can be a reasonable alternative to the in-person OSCE when primarily considering its clinical impact and suggest a viable role for virtual OSCE post-pandemic. Technological proficiency training could improve perceptions regarding future virtual OSCE implementation

Heat transport study of the spin liquid candidate 1T-TaS2

We present the ultra-low-temperature thermal conductivity measurements on single crystals of the prototypical charge-density-wave material 1$T$-TaS$_2$, which was recently argued to be a candidate for quantum spin liquid. Our experiments show that the residual linear term of thermal conductivity at zero field is essentially zero, within the experimental accuracy. Furthermore, the thermal conductivity is found to be insensitive to the magnetic field up to 9 T. These results clearly demonstrate the absence of itinerant magnetic excitations with fermionic statistics in bulk 1$T$-TaS$_2$ and, thus, put a strong constraint on the theories of the ground state of this material.Comment: 5 pages, 3 figure

An Approach to Oobtain a PLC Program from a DEVS Model

Non

Cdk5 Phosphorylates Dopamine D2 Receptor and Attenuates Downstream Signaling

The dopamine D2 receptor (DRD2) is a key receptor that mediates dopamine-associated brain functions such as mood, reward, and emotion. Cyclin-dependent kinase 5 (Cdk5) is a proline-directed serine/threonine kinase whose function has been implicated in the brain reward circuit. In this study, we revealed that the serine 321 residue (S321) in the third intracellular loop of DRD2 (D2i3) is a novel regulatory site of Cdk5. Cdk5-dependent phosphorylation of S321 in the D2i3 was observed in in vitro and cell culture systems. We further observed that the phosphorylation of S321 impaired the agonist-stimulated surface expression of DRD2 and decreased G protein coupling to DRD2. Moreover, the downstream cAMP pathway was affected in the heterologous system and in primary neuronal cultures from p35 knockout embryos likely due to the reduced inhibitory activity of DRD2. These results indicate that Cdk5-mediated phosphorylation of S321 inhibits DRD2 function, providing a novel regulatory mechanism for dopamine signaling.X111111sciescopu

Pressure-induced polarization reversal in multiferroic YMn2O5YMn_2O_5

The low-temperature ferroelectric polarization of multiferroic $YMn_2O_5$ is completely reversed at a critical pressure of 10 kbar and the phase transition from the incommensurate to the commensurate magnetic phase is induced by pressures above 14 kbar. The high-pressure data correlate with thermal expansion measurements indicating a significant lattice strain at the low-temperature transition into the incommensurate phase. The results support the exchange striction model for the ferroelectricity in multiferroic $RMn_2O_5$ compounds and they show the importance of magnetic frustration as well as the spin-lattice coupling

Theory of magnetic field-induced metaelectric critical end point in BiMn2_2O5_5

A recent experiment on the multiferroic BiMn$_2$O$_5$ compound under a strong applied magnetic field revealed a rich phase diagram driven by the coupling of magnetic and charge (dipolar) degrees of freedom. Based on the exchange-striction mechanism, we propose here a theoretical model with the intent to capture the interplay of the spin and dipolar moments in the presence of a magnetic field in BiMn$_2$O$_5$. Experimentally observed behavior of the dielectric constants, magnetic susceptibility, and the polarization is, for the most part, reproduced by our model. The critical behavior observed near the polarization reversal $(P=0)$ point in the phase diagram is interpreted as arising from the proximity to the critical end point.Comment: Theory; relevant experiment uploaded as arXiv:0810.190