The primordial deuterium abundance at z = 2.504 from a high signal-to-noise spectrum of Q1009+2956

The spectrum of the $z_{\rm em} = 2.63$ quasar Q1009+2956 has been observed extensively on the Keck telescope. The Lyman limit absorption system $z_{\rm abs} = 2.504$ was previously used to measure D/H by Burles & Tytler using a spectrum with signal to noise approximately 60 per pixel in the continuum near Ly {\alpha} at $z_{\rm abs} = 2.504$. The larger dataset now available combines to form an exceptionally high signal to noise spectrum, around 147 per pixel. Several heavy element absorption lines are detected in this LLS, providing strong constraints on the kinematic structure. We explore a suite of absorption system models and find that the deuterium feature is likely to be contaminated by weak interloping Ly {\alpha} absorption from a low column density H I cloud, reducing the expected D/H precision. We find D/H = $2.48^{+0.41}_{-0.35}\times10^{-5}$ for this system. Combining this new measurement with others from the literature and applying the method of Least Trimmed Squares to a statistical sample of 15 D/H measurements results in a "reliable" sample of 13 values. This sample yields a primordial deuterium abundance of (D/H)$_{\rm p} = (2.545 \pm 0.025)\times10^{-5}$. The corresponding mean baryonic density of the Universe is $\Omega_{\rm b}h^2 = 0.02174\pm0.00025$. The quasar absorption data is of the same precision as, and marginally inconsistent with, the 2015 CMB Planck (TT+lowP+lensing) measurement, $\Omega_{\rm b}h^2 = 0.02226\pm0.00023$. Further quasar and more precise nuclear data are required to establish whether this is a random fluctuation.Comment: accepted by MNRAS, 18 pages, 12 figures, 6 table

Corals at risk: effectiveness of the removal of a keystone coral-predator Acanthaster planci in a marine park of Malaysia

Mini‐symposium 22: Management and Conservation of Coral Reef EcosystemspostprintThe 2nd Asia Pacific Coral Reef Symposium (APCRS 2010), Phuket, Thailand, 20-24 June 2010

Reparation demands and collective guilt assignment of black South Africans

The present research studied reparation demands of born-free Black South African adolescents as members of a former victimized group from a social psychological perspective. Two cross-sectional studies tested whether identification indirectly predicts reparation demands via assignment of collective guilt to White South Africans; and whether this indirect relation is moderated by cross-group friendship. The results support both hypotheses and show a stronger link between identification with the victimized group and collective guilt assignment in a segregated rather than a desegregated context (Study 1: N = 222) and for participants reporting lower levels of cross-group friendship (Study 2: N = 145). Reparation demands are important for strongly identified members of a victimized group in a postconflict situation. Their mediation by collective guilt assignment, mitigated by cross-group friendship, indicates that one major function is to insure recognition of the victims’ past suffering and to repair the relationship rather than ostracizing the transgressor group or gaining access to resources.info:eu-repo/semantics/acceptedVersio

Rapid Evolution of the Fine-scale Recombination Landscape in Wild House Mouse (Mus musculus) Populations.

Meiotic recombination is an important evolutionary force and an essential meiotic process. In many species, recombination events concentrate into hotspots defined by the site-specific binding of PRMD9. Rapid evolution of Prdm9\u27s zinc finger DNA-binding array leads to remarkably abrupt shifts in the genomic distribution of hotspots between species, but the question of how Prdm9 allelic variation shapes the landscape of recombination between populations remains less well understood. Wild house mice (Mus musculus) harbor exceptional Prdm9 diversity, with \u3e150 alleles identified to date, and pose a particularly powerful system for addressing this open question. We employed a coalescent-based approach to construct broad- and fine-scale sex-averaged recombination maps from contemporary patterns of linkage disequilibrium in nine geographically isolated wild house mouse populations, including multiple populations from each of three subspecies. Comparing maps between wild mouse populations and subspecies reveals several themes. First, we report weak fine- and broad-scale recombination map conservation across subspecies and populations, with genetic divergence offering no clear prediction for recombination map divergence. Second, most hotspots are unique to one population, an outcome consistent with minimal sharing of Prdm9 alleles between surveyed populations. Finally, by contrasting aggregate hotspot activity on the X versus autosomes, we uncover evidence for population-specific differences in the degree and direction of sex dimorphism for recombination. Overall, our findings illuminate the variability of both the broad- and fine-scale recombination landscape in M. musculus and underscore the functional impact of Prdm9 allelic variation in wild mouse populations

The analysis of solar models: Neutrinos and oscillations

Tests of solar neutrino flux and solar oscillation frequencies were used to assess standard stellar structure theory. Standard and non-standard solar models are enumerated and discussed. The field of solar seismology, wherein the solar interior is studied from the measurement of solar oscillations, is introduced

Spinal Progenitor-Laden Bridges Support Earlier Axon Regeneration Following Spinal Cord Injury.

Impact statementSpinal cord injury (SCI) results in loss of tissue innervation below the injury. Spinal progenitors have a greater ability to repair the damage and can be injected into the injury, but their regenerative potential is hampered by their poor survival after transplantation. Biomaterials can create a cell delivery platform and generate a more hospitable microenvironment for the progenitors within the injury. In this work, polymeric bridges are used to deliver embryonic spinal progenitors to the injury, resulting in increased progenitor survival and subsequent regeneration and functional recovery, thus demonstrating the importance of combined therapeutic approaches for SCI

Molecular footprint of drug-selective pressure in a human immunodeficiency virus transmission chain

Known human immunodeficiency virus (HIV) transmission histories are invaluable models for investigating the evolutionary and transmission dynamics of the virus and to assess the accuracy of phylogenetic reconstructions. Here we have characterized an HIV-1 transmission chain consisting of nine infected patients, almost all of whom were treated with antiviral drugs at later stages of infection. Partial pol and env gp41 regions of the HIV genome were directly sequenced from plasma viral RNA for at least one sample from each patient. Phylogenetic analyses in pol using likelihood methods inferred an evolutionary history not fully compatible with the known transmission history. This could be attributed to parallel evolution of drug resistance mutations resulting in the incorrect clustering of multidrug-resistant virus. On the other hand, a fully compatible phylogenetic tree was reconstructed from the env sequences. We were able to identify and quantify the molecular footprint of drug-selective pressure in pol using maximum likelihood inference under different codon substitution models. An increased fixation rate of mutations in the HIV population of the multidrug-resistant patient was demonstrated using molecular clock modeling. We show that molecular evolutionary analyses, guided by a known transmission history, can reveal the presence of confounding factors like natural selection and caution should be taken when accurate descriptions of HIV evolution are required.status: publishe

Just hearing about it makes me feel so humiliated: Emotional and motivational responses to vicarious group-based humiliation

Witnessing a fellow ingroup member being humiliated might be the most common situation in which intergroup humiliation is experienced. Humiliation on a group level is as complex as humiliation on an interpersonal level because of shared appraisals with other emotions. We propose that witnessing a fellow ingroup member being negatively stereotyped by an outgroup member elicits anger and/or shame insofar as it is appraised as vicariously humiliating leading to anger-related approach and shame-related avoidance. Evidence for this proposition was experimentally assessed in three studies using two intergroup contexts: nationality (Study 1: n = 291) and gender (Study 2: n = 429 females and Study 3: n = 353 males). Across these intergroup contexts, the group-devaluing event emphasizing a negative ingroup stereotype evoked anger-related approach and shame-related avoidance indirectly through vicarious humiliation. We conclude that the accompanying emotions and thus resulting motivations determine whether vicarious humiliation results in intergroup conflict.info:eu-repo/semantics/publishedVersio

Leaders’ influence on collective action: An identity leadership perspective

What makes followers act collectively when called upon by their leaders? To answer this question, participants were randomly allocated to leader–follower relationships embedded either in a partisan group or a workgroup context; and the relationship between identity leadership and collective action through ingroup identification (Study 1: N = 293) or both ingroup identification and group-efficacy (Study 2: N = 338) were assessed. Based on the model of identity leadership, we predicted and found that identity leadership was positively related with intentions for collective action when called upon by the leader, both via ingroup identification and belief in group efficacy. As predicted, the social identity process for the effectiveness of identity leadership was more important in partisan groups than in workgroups. The efficacy related process was group context invariant. These results have implications for our understanding of group processes involved in the leadership in collective action.info:eu-repo/semantics/acceptedVersio