International Microsurgery Club Webinar Series—Bridging the Knowledge Gap during the COVID-19 Pandemic

Purpose The impact of the coronavirus disease 2019 (COVID-19) outbreak shut down most conferences. To minimalize the influence, virtual meetings sprang up subsequently. International Microsurgery Club (IMC), as one of the largest professionals-only online microsurgery education groups worldwide, began to host regular weekend webinars during the pandemic to fill the knowledge gap. This study aims to discuss how webinars have fundamentally changed the way knowledge is delivered and exchanged. Methods From February 29, 2020 to March 14, 2021, 103 IMC webinars were reviewed and analyzed in detail to determine the use, benefit, and effect. A comparison between webinars hosted by the different societies was made as well. A questionnaire survey focusing on attendees' behavior, attitude, and using habit about webinars was also made. Results As for the 103 IMC webinar events, the peak participants were 112.3 people in average. The members requesting to join IMC abruptly increased during the pandemic, and the group activity increased dramatically. From the questionnaire (n = 68), the satisfaction level was high (8.88 ± 1.18/10). The respondents were most satisfied with the good quality of the speakers (73.5%). Not only hosts our webinar series but IMC also serves as the platform that welcomes webinars from other societies to share their information. In September 2020, International Microsurgery Webinar League was established via the significant webinar hosts, with more than 300 recorded webinar talks connected successfully. Conclusion As the knowledge revolution driven by COVID-19 will continue, IMC will keep playing an essential role in exploring new and emerging opportunities to improve knowledge dissemination worldwide beyond the space-time boundary.

Implementation of Boundary Alert system for Fishermen

Fishing is one of the main occupations of the people who live near the coastal areas. In order to satisfy their daily requirements, fishermen need to get more fish. Once fishermen are not satisfied at a certain place, they move to further places to acquire more fish. Sometimes, without their knowledge they cross the border. Due to this, the navy of the other country arrests him and sentence them to prison. This happens because there is no awareness of boundary for the fishermen. In order to create an awareness for the fishermen, we proposed a system. Our proposed systemwill be an alternate source for avoiding such kind of accidents andalert the fishermen about the border area. In addition to that, in our project we implemented automatic turning of the boat in desired direction even when the alarm system fails to alert the fishermen by using RFtechnology. This is done byfixing the receiver in the boat and the transmitter has to be placed before 100 meters from the IMBL (International Marine time Boundary Line). This can be used to avoid crossing the boundary.

Zooarchaeology and Ancient DNA, part 2: new substrates and perspectives

The last decade has seen important technological and methodological advances in the field of palaeogenomics, constantly pushing back the time boundary and broadening our understanding of past human-animal interactions. As well as the development of sequencing technologies, a variety of organic material is being (re)evaluated as potential substrates for DNA analyses. The authors here review a selection of these, including collagenous (leather and parchment), keratinous (hair and feather) and calcified (shell and eggshell) material, and environmental DNA including coprolite. The authors focus on the biological structure of these materials in relation to DNA preservation, highlighting their singularity in comparison to bones and teeth, and inform on some of their direct applications. Finally, the authors consider some of the new perspectives these substrates can bring to our understanding of the past, notably surrounding manufacturing practices and health.

Improved Discrete-Time Boundary Condition for the Thin-Wire FDTD Analysis of Lossy Insulated Cylindrical Antennas Located in Lossy Media

For the thin-wire (TW) finite-difference time-domain (FDTD) analysis of lossy insulated antennas surrounded by lossy media, an improved discrete-time boundary condition (DTBC) at the interface is proposed here. In previous TW-FDTD techniques, the DTBC formulations on the material discontinuity between the lossy insulation and lossy surrounding media were derived from the dielectric constitutive relation under the uniform field approximation (UFA) over each time step. In this paper, to achieve higher accuracy, an improved DTBC is formulated from Maxwell’s equations under the linear field approximation (LFA) and subsequently corrected in the TW-FDTD update equation. By comparing the input impedances of Teflon-insulated cylindrical monopole antennas located in wet soils, we show that the proposed approach provides higher accuracy than previous techniques.

Twisted string theory in anti-de Sitter space

We construct a string theory in three-dimensional anti-de Sitter space-time that is independent of the boundary metric. It is a topologically twisted theory of quantum gravity. We study string theories with an asymptotic N = 2 superconformal symmetry and demonstrate that, when the world sheet coupling to the space-time boundary metric undergoes a U(1) R-symmetry twist, the space-time boundary energy-momentum tensor becomes topological. As a by-product of our analysis, we obtain the world sheet vertex operator that codes the space-time energy-momentum for conformally flat boundary metrics.

Quantum Fisher information in massless scalar field with a boundary

We explore the changes of Quantum Fisher information (QFI) for an uniformly accelerating atom coupling to fluctuating massless scalar field with a perfectly reflecting boundary. We first deduce the master equation that the system obeys. For the unbounded case, the vacuum fluctuation and Unruh thermal bath can rapidly degrade the QFI. However, with a boundary, the degradation, preservation, fluctuation and enhancement of QFI are dependent on the evolution time, boundary and acceleration. In addition, the existing boundary can effectively shield QFI from the influence of the vacuum fluctuation and Unruh thermal effect. Especially, the QFI seems to be unaffected by the vacuum fluctuation and acceleration when the atom is very close to the boundary. The efficient control of the boundary and acceleration can provide the feasible scheme of improving the parameter estimation precision.

Scalar scattering amplitude in the Gaussian wave-packet formalism

We compute an $s$-channel $2\to2$ scalar scattering $\phi\phi\to\Phi\to\phi\phi$ in the Gaussian wave-packet formalism at the tree level. We find that wave-packet effects, including shifts of the pole and the width of the propagator of $\Phi$, persist even when we do not take into account the time boundary effect for $2\to2$ proposed earlier. An interpretation of the result is that a heavy scalar $1\to2$ decay $\Phi\to\phi\phi$, taking into account the production of $\Phi$, does not exhibit the in-state time boundary effect unless we further take into account in-boundary effects for the $2\to2$ scattering. We also show various plane-wave limits.