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We investigate theoretically the optical properties of a hybrid optomechanical system embedded with a yttrium iron garnet (YIG) sphere. It is considered that YIG interacts with a single mode of the microcavity through magnetic dipole coupling. To enhance the magnomechanical coupling, the magnon mode is directly driven by a microwave field. The microcavity is driven by the control and probe field. The study of steady-state dynamics of the system shows bistable behavior. Furthermore, optomechanically induced transparency under the influence of a strong control field in the system is explored. In addition, magnomechanically induced transparency (MMIT) due to the presence of nonlinear magnon–phonon interaction is studied. Fano like shape is observed in MMIT. The impact of different system parameters is studied. Our results will provide a theoretical approach to understand opto-magnomechanical systems. These results may be useful in all optical switching devices and optical transistors. [ABSTRACT FROM AUTHOR]

Lipid droplets (LDs) are evolutionarily conserved dynamic organelles that play an important role in cellular physiology. Growing evidence suggests that LD biogenesis occurs at discrete endoplasmic reticulum (ER) subdomains demarcated by the lipodystrophy protein, Seipin, lack of which impairs adipogenesis. However, the mechanisms of how these domains are selected is not completely known. These ER sites undergo ordered assembly of proteins and lipids to initiate LD biogenesis and facilitate establishment of ER-LD contact sites, a prerequisite for proper growth and maturation of droplets. LDs retain both physical and functional association with the ER throughout their lifecycle to facilitate bi-directional communication, such as exchange of proteins and lipids between the two organelles at these ER-LD contact sites. In recent years several molecular tethers have been identified that bridge ER and LDs together including few proteins that are found exclusively at these ER-LD contact interface. Here, we discuss recent advances in understanding the role of factors that ensure functionality of ER-LD contact site machinery for LD homeostasis. [ABSTRACT FROM AUTHOR]

We theoretically investigate optical bistability and entanglement in a hybrid nonlinear system of two coupled cavities via a single-mode waveguide. The left cavity contains an ensemble of N quantum dots (QDs) and a Kerr medium to enhance the nonlinearity as it causes to observe the bistable behaviour of the system. We study the Kerr medium, QD ensemble, and cavity coupling effect on bistability response shown by mean intracavity photons in the left cavity. In addition, we have shown entanglement between different subsystems and found that entanglement can be generated between the two coupled cavity photons, cavity photons, and QD ensembles. Additionally, we investigate the effect of different parameters on entanglement. Our findings show that Kerr nonlinearity and the hopping parameter between the two cavities can effectively control the optical properties of the proposed hybrid system, which can be used to design efficient optical devices and the entangled optical photons have applications such as quantum information transfer. [ABSTRACT FROM AUTHOR]

We investigate the collective dynamics and dynamical phases of the two optical mode non-equilibrium Dicke model. We show that the collective interaction of the ensemble of atoms with all the optical modes of the system is the determining factor for the superradiant phase transition instead of interaction with each individual mode. The critical condition to observe the superradiant phase transition is derived for the multi-mode Dicke model. The mean-field dynamics of the two optical mode Dicke model is analyzed for above an below the superradiant phase. It is found that tuning one of the mode influences the dynamics associated with the second mode. We also analyze the dynamical phase diagram of the two-mode case by studying the time evolution of the collective atomic spin operator Jz(t) in the stable and the unstable regions of the phase diagrams. [ABSTRACT FROM AUTHOR]

Background: The school-based food and nutrition guidelines approach has the potential to combat undernutrition, overnutrition and micronutrient deficiencies among children and adolescents and set the foundation for a healthy adult lifestyle. Aim: To critically compare the Nutrition Friendly School Initiative (NFSI) of the World Health Organization (WHO) with the Food Safety and Standards Authority of India (FSSAI) and the Indian Academy of Pediatrics (IAP) guidelines to gauge the strengths and limitations. Additionally, to summarize the existing studies on implementing school food and nutrition guidelines. Methods: Policy documents of the above guidelines were critically evaluated, and narrative analysis was conducted. An electronic search was conducted for full-text research articles published in the English language between January 2007 to September 2021 in Science Direct, PubMed, Web of Science, and SCOPUS databases. Results: Upon critical comparison of the three guidelines, it was found that the NFSI and FSSAI guidelines shared similarities in many components and the FSSAI guidelines, if implemented adequately, could improve the school food environment and combat the triple malnutrition burden in India. After screening the articles based on the eligibility criteria, 11 studies were included in the preparation of the review. Studies reported partial or inadequate implementation and poor compliance with the guidelines or approach. A few studies identified barriers to guideline implementation. Conclusion: Implementation of school food and nutrition guidelines could improve the nutritional outcomes in children and adolescents. To sustain the effective implementation, adequate resources and preparedness are essential in low-and middle-income countries, including India. [ABSTRACT FROM AUTHOR]