In the context of a global shift toward the prioritization of individual freedom and human rights, the tension between personal autonomy and social order has become increasingly visible in many societies, including Vietnam. As a rapidly integrating nation in both economic and cultural terms, Vietnam is facing new challenges in reconciling international values of freedom with its traditional societal structures. Rooted in Southeast Asian cultural heritage and shaped by Confucian and collectivist norms, Vietnamese traditional communities place a strong emphasis on hierarchy, communal responsibility, and social harmony. These cultural features have historically ensured order and cohesion but now increasingly intersect—and at times conflict— with emerging notions of individual rights. This paper examines how Vietnam navigates the evolving balance between maintaining its deep-rooted cultural order and adapting to the rising global emphasis on individual freedom in the context of modernization and international integration.
Jets and disk winds arise from materials with excess angular momentum ejected from the accretion disks in forming stars. How these structures are launched and how they impact the gas within the innermost regions of these objects remains poorly understood. MWC349A is a massive star that has a circumstellar disk that rotates in accord with Kepler's Law, with an ionized wind and a high-velocity jet launched from the disk surface. The strongly maser-amplified emission of hydrogen radio recombination lines (RRLs) observed toward this system provides a comprehensive picture of its ionized environment with exquisite detail. In this Letter, we present Atacama Large Millimeter/submillimeter Array observations of the H26 alpha RRL and continuum emission obtained with the highest angular resolution ever used toward this source (beam of similar to 0.'' 02). The maser RRL emission is resolved for the first time and clearly delineates the ionized disk, wind, and jet. We analyzed the RRL data cubes with the 3D non-LTE radiative transfer model MORELI, confirming that the jet is poorly collimated. We found that the jet orientation is closer to the rotation axis of the system than derived from spatially unresolved data. This study confirms that hydrogen RRL masers are powerful probes of the physical structure and kinematics of the innermost ionized material around massive stars.
MWC 349A is one of the rare stars known to have hydrogen radio recombination line (RRL) masers. The bright maser emission makes it possible to study the dynamics of the system at milliarcsecond (mas) precision. We present Atacama Large Millimeter/submillimeter Array observations of the 1.4 and 0.8 mm continuum emission of MWC 349A, as well as the H30 α and H26 α RRLs. Using the most extended array configuration of C43-10 with a maximum baseline of 16.2 km, we spatially resolved the H30 α line and 1.4 mm continuum emission for the first time. In addition to the known H30 α and H26 α maser emission from a Keplerian disk at LSR velocities from −12 to 28 km s −1 and from an ionized wind for velocities between −12 to −40 km s −1 and 28 to 60 km s −1 , we found evidence of a jet along the polar axis at V LSR from −85 to −40 km s −1 and +60 to +100 km s −1 . These masers are found in a linear structure nearly aligned with the polar axis of the disk. If these masers lie close to the polar axis, their velocities could be as high as 575 km s −1 , which cannot be explained solely by a single expanding wind as proposed in Báez-Rubio et al. We suggest that they originate from a high-velocity jet, likely launched by a magnetohydrodynamic wind. The jet appears to rotate in the same direction as the rotation of the disk. A detailed radiative transfer modeling of these emissions will further elucidate the origin of these masers in the wind.
MWC 349A is a massive star with a well-known circumstellar disk rotating following a Keplerian law, and an ionized wind launched from the disk surface. Recent observations with the Atacama Large Millimeter/submillimeter Array (ALMA) carried out toward this system, however, have revealed an additional high-velocity component in the strong, maser emission of hydrogen radio recombination lines (RRLs), suggesting the presence of a high-velocity ionized jet. In this work, we present 3D non-LTE radiative transfer modeling of the emission of the H30 α and H26 α maser lines, and of their associated radio continuum emission, toward MWC 349A. By using the MORELI code, we reproduce the spatial distribution and kinematics of the high-velocity emission of the H30 α and H26 α maser lines with a high-velocity ionized jet expanding at a velocity of ∼250 km s −1 , surrounded by MWC 349A’s wide-angle ionized wind. The bipolar jet, which is launched from MWC 349A’s disk, is poorly collimated and slightly misaligned with respect to the disk rotation axis. Thanks to the unprecedented sensitivity and spatial accuracy provided by ALMA, we also find that the already known, wide-angle ionized wind decelerates as it expands radially from the ionized disk. We briefly discuss the implications of our findings for understanding the formation and evolution of massive stars. Our results show the huge potential of RRL masers as powerful probes of the innermost ionized regions around massive stars and of their high-velocity jets.
The Internet of Medical Things (IoMT) is one the most practical and useful applications of the Internet of Things (IoT), achieved by connecting medical devices and applications to the online healthcare system. IoMT, if fully and properly implemented, in our healthcare systems can save precious lives and can be a boon to healthcare professionals, especially when addressing challenges caused by pandemics such as COVID-19 and other communicable diseases. In an IoMT, machine-to machine connectivity is possible through short-range communication devices such as Bluetooth or long-range communications (using 5G communication). However security and privacy remain a major challenge faced by IoMT developers and stakeholders. Transmission of critical medical information to the cloud computing setup wirelessly without addressing security issues introduces the risk of hacking and data corruption. It is paramount that the potential security issues are identified and appropriate security measures are implemented. This chapter discussed the various security vulnerabilities that have been identified by researchers and also highlights innovative solutions that have been proposed by researchers. Various solutions such as malware detection, usage of multimodal feature-based biometric identification schemes, ontology-based recommendation tool for addressing various IoMT threat scenarios, and blockchain-enabled authentication techniques are some of the approaches that are discussed and summarized in this chapter.
