Non-radiative configurations of a few quantum emitters ensembles: evolutionary optimization approach

In this work, we employ differential evolution algorithm to identify the optimal configurations of small atomic ensembles supporting quantum states with maximal radiative lifetime. We demonstrate that atoms mostly tend to assemble in quasi-regular structures with specific geometry strongly depending on the minimal interatomic distance $r_{min}$. We identified the clear underlying physics that governs the suppression of the radiative losses in particular geometries. However, we reveal that the specific configurations in small ensembles are not easily predictable based on the knowledge established for the arrays of large size. In particular, the states that inherit their properties from bound states in continuum in infinite lattices turn out to be the most subradiant in a wide range of $r_{min}$ values. We also show that for small interatomic distance the chains with modulated interatomic distances exhibit fast exponential decrease of the radiative losses with the size of the ensemble

Global Change Impacts on Indigenous Sustainability in Sakha Republic: A Synthesis of Knowledge

Indigenous understanding of sustainability is embedded in close relations to land and environment, Indigenous Knowledge systems, Indigenous epistemologies and ontologies, and Indigenous languages. However, the sustainability of Indigenous peoples’ livelihoods is significantly affected by various global change drivers. In the Arctic, Indigenous peoples’ livelihoods are impacted by environmental, social, and cultural changes, including climate change, environmental pollution, economic processes, and resource extraction. This paper aims to review and synthesize recent academic and gray literature on the sustainability of Indigenous communities in Sakha Republic, Northeast Siberia, Russia in the face of global change with a particular focus on land- and water-based traditional activities, native language, and the Indigenous Knowledge system

Noise diodes as a source of entropy for hardware random number generators

The purpose of this article is to describe the use of digital noise generators based on semiconductor noise diodes as part of systems for generating key numerical sequences used in cryptographic security methods. The classification of modern methods of cryptographic protection and the algorithms underlying them are considered. It is shown that ensuring high information entropy in systems for generating encryption keys is possible by using generators of truly random number sequences and cryptographically secure generators of pseudo-random number sequences. A number of disadvantages inherent in widely used sources of physical noise are described, namely: low spectral density of broadband noise, limited frequency range, nonlinearity of the noise spectrum, difficulties in technical implementation when using some methods, especially under conditions of extreme temperatures and exposure to special factors. It has been confirmed that the noise properties of semiconductor noise diodes depend on the composition and constancy of the defect-impurity structure, and defect engineering makes it possible to control their electrical parameters. The study of inhomogeneities and defects in noise diodes and the development on this basis of methods for controlling the level of structural defects made it possible to create technologies for their generation and annealing, and to improve a number of electrical and statistical properties of noise diodes

Regional geographies and public health lessons of the COVID-19 pandemic in the Arctic

Objectives: This study examines the COVID-19 pandemic’s spatiotemporal dynamics in 52 sub-regions in eight Arctic states. This study further investigates the potential impact of early vaccination coverage on subsequent COVID-19 outcomes within these regions, potentially revealing public health insights of global significance. Methods: We assessed the outcomes of the COVID-19 pandemic in Arctic sub-regions using three key epidemiological variables: confirmed cases, confirmed deaths, and case fatality ratio (CFR), along with vaccination rates to evaluate the effectiveness of the early vaccination campaign on the later dynamics of COVID-19 outcomes in these regions. Results: From February 2020 to February 2023, the Arctic experienced five distinct waves of COVID-19 infections and fatalities. However, most Arctic regions consistently maintained Case Fatality Ratios (CFRs) below their respective national levels throughout these waves. Further, the regression analysis indicated that the impact of initial vaccination coverage on subsequent cumulative mortality rates and Case Fatality Ratio (CFR) was inverse and statistically significant. A common trend was the delayed onset of the pandemic in the Arctic due to its remoteness. A few regions, including Greenland, Iceland, the Faroe Islands, Northern Canada, Finland, and Norway, experienced isolated spikes in cases at the beginning of the pandemic with minimal or no fatalities. In contrast, Alaska, Northern Sweden, and Russia had generally high death rates, with surges in cases and fatalities. Conclusion: Analyzing COVID-19 data from 52 Arctic subregions shows significant spatial and temporal variations in the pandemic’s severity. Greenland, Iceland, the Faroe Islands, Northern Canada, Finland, and Norway exemplify successful pandemic management models characterized by low cases and deaths. These outcomes can be attributed to successful vaccination campaigns, and proactive public health initiatives along the delayed onset of the pandemic, which reduced the impact of COVID-19, given structural and population vulnerabilities. Thus, the Arctic experience of COVID-19 informs preparedness for future pandemic-like public health emergencies in remote regions and marginalized communities worldwide that share similar contexts