Equilibration processes in the Warm-Hot Intergalactic Medium

The Warm-Hot Intergalactic Medium (WHIM) is thought to contribute about 40-50 % to the baryonic budget at the present evolution stage of the universe. The observed large scale structure is likely to be due to gravitational growth of density fluctuations in the post-inflation era. The evolving cosmic web is governed by non-linear gravitational growth of the initially weak density fluctuations in the dark energy dominated cosmology. Non-linear structure formation, accretion and merging processes, star forming and AGN activity produce gas shocks in the WHIM. Shock waves are converting a fraction of the gravitation power to thermal and non-thermal emission of baryonic/leptonic matter. They provide the most likely way to power the luminous matter in the WHIM. The plasma shocks in the WHIM are expected to be collisionless. Collisionless shocks produce a highly non-equilibrium state with anisotropic temperatures and a large differences in ion and electron temperatures. We discuss the ion and electron heating by the collisionless shocks and then review the plasma processes responsible for the Coulomb equilibration and collisional ionisation equilibrium of oxygen ions in the WHIM. MHD-turbulence produced by the strong collisionless shocks could provide a sizeable non-thermal contribution to the observed Doppler parameter of the UV line spectra of the WHIM.Comment: 13 pages, 4 figures, accepted for publication in Space Science Reviews, special issue "Clusters of galaxies: beyond the thermal view", Editor J.S. Kaastra, Chapter 8; work done by an international team at the International Space Science Institute (ISSI), Bern, organised by J.S. Kaastra, A.M. Bykov, S. Schindler & J.A.M. Bleeke

Carbonate-Templated Self-Assembly of an Alkylthiolate-Bridged Cadmium Macrocycle

In the presence of Cd(ClO4)2 and a base, a new mixed N,S-donor alkylthiolate ligand supported both carbonate formation from atmospheric CO2 and the self-assembly of a novel bicapped puckered (CdS)6 molecular wheel. The remarkable stability of the complex was demonstrated by slow intermolecular ligand exchange on the 2J(HH) and J(111/113Cd1H) time scales at elevated temperature. Both CO2 and the base were required to convert amorphous “CdLClO4” precipitated in the absence of air to the carbonate complex. The complex shares structural features with the ζ-carbonic anhydrase class associating cadmium(II) with the biogeochemical cycling of carbon and is the first structurally characterized carbonate complex of any metal involving an alkylthiolate ligand

Clusters of COVID-19 protective and risky behaviors and their associations with pandemic, socio-demographic, and mental health factors in the United States.

Individual behaviors are critical for preventing the spread of coronavirus disease 2019 (COVID-19) infection. Given that both protective and risky behaviors influence risk of infection, it is critical that we understand how such behaviors cluster together and in whom. Using a data-driven approach, we identified clusters of COVID-19-related protective and risky behaviors and examined associations with socio-demographic, pandemic, and mental health factors. Data came from a cross-sectional online U.S. nationwide study of 832 adults with high levels of pre-pandemic trauma. Latent class analysis was performed with ten protective (e.g., washing hands, wearing masks) and eight risky (e.g., attending indoor restaurants, taking a flight) behaviors for COVID-19. Then, we examined distributions of socio-demographic and pandemic factors across behavior classes using ANOVA or Chi-square tests, and associations between mental health factors (depressive, anxiety, posttraumatic stress symptoms) and behavior classes using multinomial logistic regression. We identified four classes, including three classes with relatively low risky but high (28.8%), moderate (33.5%) and minimal (25.5%) protective behaviors and one high risky behaviors class with associated moderate protective behaviors (12.1%). Age, sexual orientation, political preference, and most pandemic factors differed significantly across behavior classes. Anxiety and posttraumatic stress symptoms, but not depression, were higher in the High Risk, but also Highly and Moderately Protective classes, relative to Minimally Protective. Prevention and intervention efforts should examine constellations of protective and risky behaviors to comprehensively understand risk, and consider current anxiety and posttraumatic stress symptoms as potential risk indicators

Posttraumatic stress disorder symptoms associated with protective and risky behaviors for coronavirus disease 2019.

ObjectivePsychiatric disorders increase risk for contracting coronavirus disease 2019 (COVID-19), but we know little about relationships between psychiatric symptoms and COVID-19 risky and protective behaviors. Posttraumatic stress disorder (PTSD) has been associated with increased propensity to engage in risky behaviors, but may also be associated with increased COVID-19 protective behaviors due to increased threat sensitivity and social isolation.MethodWe examined associations of PTSD symptoms with COVID-19-related protective and risky behaviors using data from a cross-sectional online United States study among 845 US adults in August through September 2020. PTSD symptoms (PTSD Checklist-5), sociodemographics, COVID-19-related experiences and vulnerabilities, and past 30-day engagement in 10 protective and eight risky behaviors for COVID-19 were assessed via self-report. We examined associations between PTSD symptoms and COVID-19 protective and risky behaviors with linear regressions, adjusting for covariates.ResultsProbable PTSD and higher PTSD symptom severity were associated with greater engagement in protective behaviors, but also greater engagement in risky behaviors. Associations were only slightly attenuated by adjustment for COVID-19 exposures and perceived likelihood and severity of COVID-19. Associations varied by PTSD clusters: intrusions and arousal were associated with both more protective and more risky behaviors, whereas negative cognitions or mood was associated only with more risky, and avoidance only with more protective, behaviors.ConclusionHigher PTSD symptoms were associated with engagement in more protective but also more risky behaviors for COVID-19. Mental health should be considered in the design of public health campaigns dedicated to limiting infectious disease spread. (PsycInfo Database Record (c) 2022 APA, all rights reserved)

ARBitrator: a software pipeline for on-demand retrieval of auto-curated nifH sequences from GenBank

MotivationStudies of the biochemical functions and activities of uncultivated microorganisms in the environment require analysis of DNA sequences for phylogenetic characterization and for the development of sequence-based assays for the detection of microorganisms. The numbers of sequences for genes that are indicators of environmentally important functions such as nitrogen (N2) fixation have been rapidly growing over the past few decades. Obtaining these sequences from the National Center for Biotechnology Information's GenBank database is problematic because of annotation errors, nomenclature variation and paralogues; moreover, GenBank's structure and tools are not conducive to searching solely by function. For some genes, such as the nifH gene commonly used to assess community potential for N2 fixation, manual collection and curation are becoming intractable because of the large number of sequences in GenBank and the large number of highly similar paralogues. If analysis is to keep pace with sequence discovery, an automated retrieval and curation system is necessary.ResultsARBitrator uses a two-step process composed of a broad collection of potential homologues followed by screening with a best hit strategy to conserved domains. 34 420 nifH sequences were identified in GenBank as of November 20, 2012. The false-positive rate is ∼0.033%. ARBitrator rapidly updates a public nifH sequence database, and we show that it can be adapted for other genes.Availability and implementationJava source and executable code are freely available to non-commercial users at http://pmc.ucsc.edu/∼wwwzehr/research/database/[email protected] informationSUPPLEMENTARY INFORMATION is available at Bioinformatics online