Ordering kinetics and steady states of XY-model with ferromagnetic and nematic interaction.

Previous studies on the generalized XY model have concentrated on the equilibrium phase diagram and the equilibrium nature of distinct phases under varying parameter conditions. We direct our attention towards examining the system's evolution towards equilibrium states across different parameter values, specifically by varying the relative strengths of ferromagnetic and nematic interactions. We study the kinetics of the system, using the temporal annihilation of defects at varying temperatures and its impact on the coarsening behavior of the system. For both pure polar and pure nematic systems, we observe temperature-dependent decay of the exponent, leading to a decelerated growth of domains within the system. At parameter values where both ferromagnetic and nematic interactions are simultaneously present, we show a phase diagram highlighting three low-temperature phases-polar, nematic, and coexistence-along- side a high-temperature disordered phase. Our study provides valuable insights into the complex interplay of interactions, offering a comprehensive understanding of the system's behavior during its evolution towards equilibrium.

Otogenic Cerebellar Abscess with Polymicrobial Anaerobic Infection in a Young Female- A Rare Presentation.

Brain abscess is a serious clinical condition caused by a localized collection of pus within the brain tissue. This typically occurs as a result of an infection that originates from a nearby area, such as an ear, sinus, or dental infection, or an infection in the bloodstream. Streptococcus and Staphylococcus species are the most common organisms implicated in brain abscesses. Apart from aerobic growth, cases of mixed infections of both aerobic and anaerobic organisms are also commonly reported in the literature. Herein we report a 23-year-old immunocompetent female with chronic otitis media who presented with cerebellar abscess where the aerobic growth was sterile and anaerobic culture revealed pure growth of dual anaerobes viz… Peptostreptococcus and Bacteroides thetaiotaomicron. This case highlights the importance of prompt diagnosis and management of polymicrobial anaerobic infection in cases of brain abscess.

Current reversal in polar flock at order-disorder interface.

We studied a system of polar self-propelled particles (SPPs) on a thin rectangular channel designed into three regions of order-disorder-order. The division of the three regions is made on the basis of the noise SPPs experience in the respective regions. The noise in the two wide regions is chosen lower than the critical noise of order-disorder transition and noise in the middle region or interface is higher than the critical noise. This makes the geometry of the system analogous to the Josephson junction (JJ) in solid-state physics. Keeping all other parameters fixed, we study the properties of the moving SPPs in the bulk as well as along the interface for different widths of the junction. On increasing interface width, the system shows an order-to-disorder transition from coherent moving SPPs in the whole system to the interrupted current for large interface width. Surprisingly, inside the interface, we observed the current reversal for intermediate widths of the interface. Such current reversal is due to the strong randomness present inside the interface, which makes the wall of the interface reflecting. Hence, our study gives new interesting collective properties of SPPs at the interface which can be useful to design switching devices using active agents.