541 research outputs found
Diplomatic Impact in the Stars? A Review of the Impact of the Artemis Accords on Global Relationships
This essay examines the near-term and possible long-range impacts of the Artemis Accords on our relationships to our allies and whether the accords amount to a significant narrative shift in international space relations. Per the National Aeronautics and Space Administration (NASA), the Accords “describe a shared vision for principles, grounded in the Outer Space Treaty of 1967, to create a safe and transparent environment which facilitates exploration, science, and commercial activities for all of humanity to enjoy.” Many U.S. space allies have already signed, but do these accords truly strengthen our international relationships? Will they create a notable change in how space-faring nations approach contentious space policies in the future? To examine these questions this paper explores and explains the history, purpose, and intent of the Artemis Accords, followed by the international reactions among U.S. allies and adversaries, and an assessment of the current impact of the Accords on existing international space laws and norms
Self-Reported Long COVID in the General Population: Sociodemographic and Health Correlates in a Cross-National Sample.
We aimed to gain knowledge of possible sociodemographic predictors of long COVID and whether long COVID was associated with health outcomes almost two years after the pandemic outbreak. There were 1649 adults who participated in the study by completing a cross-sectional online survey disseminated openly in Norway, the UK, the USA, and Australia between November 2021 and January 2022. Participants were defined as having long COVID based on self-reports that they had been infected by COVID-19 and were experiencing long-lasting COVID symptoms. Logistic regression analyses were used to examine possible sociodemographic predictors, and multivariate analysis of variance was used to examine whether long COVID status was associated with health outcomes. None of the sociodemographic variables was significantly associated with reporting long COVID. Having long COVID was associated with higher levels of psychological distress, fatigue, and perceived stress. The effect of long COVID on health outcomes was greater among men than among women. In conclusion, long COVID appeared across sociodemographic groups. People with long COVID reported worsened health outcomes compared to those who had had COVID-19 but without long-term symptoms. Men experiencing long COVID appear to be particularly vulnerable to experiencing poorer health outcomes; health services may pay extra attention to potentially unnoticed needs for support among men experiencing long COVID
ENERGETIC PARTICLE DIFFUSION IN CRITICALLY BALANCED TURBULENCE
Observations and modeling suggest that the fluctuations in magnetized plasmas exhibit scale-dependent anisotropy, with more energy in the fluctuations perpendicular to the mean magnetic field than in the parallel fluctuations and the anisotropy increasing at smaller scales. The scale dependence of the anisotropy has not been studied in full-orbit simulations of particle transport in turbulent plasmas so far. In this paper, we construct a model of critically balanced turbulence, as suggested by Goldreich & Sridhar, and calculate energetic particle spatial diffusion coefficients using full-orbit simulations. The model uses an enveloped turbulence approach, where each two-dimensional wave mode with wavenumber k ⊥ is packed into envelopes of length L following the critical balance condition, Lk –2/3 ⊥, with the wave mode parameters changing between envelopes. Using full-orbit particle simulations, we find that both the parallel and perpendicular diffusion coefficients increase by a factor of two, compared to previous models with scale-independent anisotropy
Endothelin receptors (version 2019.4) in the IUPHAR/BPS Guide to Pharmacology Database
Endothelin receptors (nomenclature as agreed by the NC-IUPHAR Subcommittee on Endothelin Receptors [24]) are activated by the endogenous 21 amino-acid peptides endothelins 1-3 (endothelin-1, endothelin-2 and endothelin-3)
Healthy Aging and Dietary Patterns
A number of factors contribute to the complex process of aging, which finally define whether someone will or not develop age-associated chronic diseases in late life. These determinants comprise genetic susceptibility as well as various behavioral, environmental, and dietary factors, all of which have been shown to influence specific pathways regulating the aging process and the extension of life, which makes longevity a multidimensional phenomenon. Although a “miraculous elixir” or a “nutrition pill” are not plausible, researchers agree on the notion that nutritional factors have major impact on the risk of age-associated chronic non-communicable diseases and mortality. In recent years nutrition research in relation to health outcomes has considerably changed from focusing exclusively on single nutrients to considering combinations of foods rather than nutrients in isolation. Although research on specific nutrients is scientifically valid providing crucial evidence on the mechanisms by which nutrition impacts health, the recent switch targeting the multifaceted synergistic interplay among nutrients, other dietary constituents, and whole foods, has promoted emerging interest on the actions of total dietary patterns. This narrative review aims to describe some specific dietary patterns with evidence of associations with reduction in the incidence of chronic diseases allowing older adults to live a long-lasting and healthier life, and confirming the powerful impact nutrition can exert on healthy aging. © 2022 by the authors. Licensee MDPI, Basel, Switzerland
Energetic particle transport across the mean magnetic field: before diffusion
Current particle transport models describe the propagation of charged particles across the mean field direction in turbulent plasmas as diffusion. However, recent studies suggest that at short time- scales, such as soon after solar energetic particle (SEP) injection, particles remain on turbulently meandering field lines, which results in non-diffusive initial propagation across the mean magnetic field. In this work, we use a new technique to investigate how the particles are displaced from their original field lines, and quantify the parameters of the transition from field-aligned particle propagation along meandering field lines to particle diffusion across the mean magnetic field. We show that the initial decoupling of the particles from the field lines is slow, and particles remain within a Larmor radius from their initial meandering field lines for tens to hundreds of Larmor periods, for 0.1-10 MeV protons in turbulence conditions typical of the solar wind at 1 AU. Subsequently, particles decouple from their initial field lines and after hundreds to thousands of Larmor periods reach time-asymptotic diffusive behaviour consistent with particle diffusion across the mean field caused by the meandering of the field lines. We show that the typical duration of the pre-diffusive phase, hours to tens of hours for 10 MeV protons in 1 AU solar wind turbulence conditions, is significant for SEP propagation to 1 AU and must be taken into account when modelling SEP propagation in the interplanetary space
Advanced mortar coatings for cultural heritage protection : Durability towards prolonged UV and outdoor exposure
In the present work, two kinds of hybrid polymeric\u2013inorganic coatings containing TiO2 or SiO2 particles and prepared starting from two commercial resins (Alpha\uaeSI30 and Bluesil\uaeBP9710) were developed and applied to two kinds of mortars (an air-hardening calcic lime mortar [ALM] and a natural hydraulic lime mortar [HLM]) to achieve better performances in terms of water repellence and consequently damage resistance. The two pure commercial resins were also applied for comparison purposes. Properties of the coated materials and their performance were studied using different techniques such as contact angle measurements, capillary absorption test, mercury intrusion porosimetry, surface free energy, colorimetric measurements and water vapour permeability tests. Tests were also performed to determine the weathering effects on both the commercial and the hybrid coatings in order to study their durability. Thus, exposures to UV radiation, to UV radiation/condensed water cycles and to a real polluted atmospheric environment have been performed. The effectiveness of the hybrid SiO2 based coating was demonstrated, especially in the case of the HLM mortar
Kolmogorov-Sinai entropy in field line diffusion by anisotropic magnetic turbulence
The Kolmogorov-Sinai (KS) entropy in turbulent diffusion of magnetic field
lines is analyzed on the basis of a numerical simulation model and theoretical
investigations. In the parameter range of strongly anisotropic magnetic
turbulence the KS entropy is shown to deviate considerably from the earlier
predicted scaling relations [Rev. Mod. Phys. {\bf 64}, 961 (1992)]. In
particular, a slowing down logarithmic behavior versus the so-called Kubo
number (, where is the ratio of the rms magnetic fluctuation field to the magnetic field
strength, and and are the correlation lengths in respective
dimensions) is found instead of a power-law dependence. These discrepancies are
explained from general principles of Hamiltonian dynamics. We discuss the
implication of Hamiltonian properties in governing the paradigmatic
"percolation" transport, characterized by , associating it with the
concept of pseudochaos (random non-chaotic dynamics with zero Lyapunov
exponents). Applications of this study pertain to both fusion and astrophysical
plasma and by mathematical analogy to problems outside the plasma physics.
This research article is dedicated to the memory of Professor George M.
ZaslavskyComment: 15 pages, 2 figures. Accepted for publication on Plasma Physics and
Controlled Fusio
Coronary Thrombolysis with Intravenous Streptokinase in the Anesthetized Dog: A Dose-Response Study
ABSTRAC
Solar Magnetic Polarity Effect on Neutron Monitor Count Rates: Comparing Latitude Surveys and Antarctic Stations
The Galactic cosmic ray spectrum manifests pronounced variations over the
11-year sunspot cycle and more subtle variations over the 22-year solar
magnetic cycle. An important tool to study these variations is repeated
latitude surveys with neutron monitors (NMs) onboard icebreakers in conjunction
with land-based references. We revisit 13 annual latitude surveys from 1994 to
2007 using reference data from the Mawson NM instead of McMurdo NM (which
closed in 2017). We then consider two more latitude surveys (2018 and 2019)
with a monitor similar to the 3NM64 in the previous surveys but without lead
rings around the central tube, a so-called ``semi-leaded neutron monitor.'' The
new surveys extend the linear relationship among data taken at different cutoff
rigidity ranges. They also confirm the ``crossover'' measured near solar minima
during epochs of opposite solar magnetic polarity and the absence of a
crossover for epochs having the same solar magnetic polarity.Comment: Accepted for publication in Astrophys.
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