Dynamics and Radiation of Young Type-Ia Supernova Remnants: Important Physical Processes

We examine and analyze the physical processes that should be taken into account when modeling young type-Ia SNRs, with ages of several hundred years. It is shown, that energy losses in the metal-rich ejecta can be essential for remnants already at this stage of evolution. The influence of electron thermal conduction and the rate of the energy exchange between electrons and ions on the temperature distribution and the X-radiation from such remnants is studied. The data for Tycho SNR from the XMM-Newton X-ray telescope have been employed for the comparison of calculations with observations.Comment: 19 pages, 8 figure

Three pillars of sustainability: in search of conceptual origins

The three-pillar conception of (social, economic and environmental) sustainability, commonly represented by three intersecting circles with overall sustainability at the centre, has become ubiquitous. With a view of identifying the genesis and theoretical foundations of this conception, this paper reviews and discusses relevant historical sustainability literature. From this we find that there is no single point of origin of this three-pillar conception, but rather a gradual emergence from various critiques in the early academic literature of the economic status quo from both social and ecological perspectives on the one hand, and the quest to reconcile economic growth as a solution to social and ecological problems on the part of the United Nations on the other. The popular three circles diagram appears to have been first presented by Barbier (Environ Conserv 14:101, doi: 10.1017/s0376892900011449, 1987), albeit purposed towards developing nations with foci which differ from modern interpretations. The conceptualisation of three pillars seems to predate this, however. Nowhere have we found a theoretically rigorous description of the three pillars. This is thought to be in part due to the nature of the sustainability discourse arising from broadly different schools of thought historically. The absence of such a theoretically solid conception frustrates approaches towards a theoretically rigorous operationalisation of ‘sustainability’

Relationship Between the U.S. Air Force Physical Fitness Assessment and Healthcare Utilization

Escalating health care costs in the military health system are not sustainable long term. Regular physical activity has been shown to improve health and reduce health care costs. Military members serving in the United States Air Force (USAF) are encouraged to maintain physical fitness year-round and undergo mandatory physical fitness assessments (PFAs) annually. The purpose of this quantitative correlational study was to determine the nature of the relationship between the timing of the PFA and health care utilization (HU) by active duty service members assigned to the United Kingdom's USAF military treatment facility. Donabedian's framework and the logic process model were used to design the study. Archived fitness and health care utilization data were obtained on 361 military members. Findings indicated a strong, positive correlation between the timing of the PFA and HU, which was strongest during the PFA month. Monthly HU 6 months prior to PFA was compared using a 1-way repeated measures ANOVA. Findings indicated a significant difference between T-1 (PFA month), T-2 (1 month prior to PFA), and T-5 (5 months prior to PFA). Paired-samples t tests demonstrated a statistically significant increase in HU from T-5 to T-2. Although findings are not generalizable, they signal a need for further study to evaluate HU variability between populations, to identify at-risk groups, and to inform health and fitness policies that affect the readiness and retention of military members. The DNP project may promote interdisciplinary collaboration between health care providers and senior military leadership, innovation in health care delivery, and evidence-based and cost-conscious policies

Regional perspectives

In UNESCO World Water Assessment Programme (WWAP). The United Nations World Water Development Report 2023: partnerships and cooperation for water. Paris, France: UNESC