36 research outputs found

    HELIUM PHOTODISINTEGRATION AND NUCLEOSYNTHESIS: IMPLICATIONS FOR TOPOLOGICAL DEFECTS, HIGH ENERGY COSMIC RAYS, AND MASSIVE BLACK HOLES

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    We consider the production of 3^3He and 2^2H by 4^4He photodisintegration initiated by non-thermal energy releases during early cosmic epochs. We find that this process cannot be the predominant source of primordial 2^2H since it would result in anomalously high 3^3He/D ratios in conflict with standard chemical evolution assumptions. We apply this fact to constrain topological defect models of highest energy cosmic ray (HECR) production. Such models have been proposed as possible sources of ultrahigh energy particles and gamma-rays with energies above 102010^{20}eV. The constraints on these models derived from 4^4He-photodisintegration are compared to corresponding limits from spectral distortions of the cosmic microwave background radiation (CMBR) and from the observed diffuse gamma-ray background. It is shown that for reasonable primary particle injection spectra superconducting cosmic strings, unlike ordinary strings or annihilating monopoles, cannot produce the HECR flux at the present epoch without violating at least the 4^4He-photodisintegration bound. The constraint from the diffuse gamma-ray background rules out the dominant production of HECR by the decay of Grand Unification particles in models with cosmological evolution assuming standard fragmentation functions. Constraints on massive black hole induced photodisintegration are also discussed.Comment: 20 latex pages, 1 figure added via figures comman

    Social mindfulness and prosociality vary across the globe

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    Humans are social animals, but not everyone will be mindful of others to the same extent. Individual differences have been found, but would social mindfulness also be shaped by one’s location in the world? Expecting cross-national differences to exist, we examined if and how social mindfulness differs across countries. At little to no material cost, social mindfulness typically entails small acts of attention or kindness. Even though fairly common, such low-cost cooperation has received little empirical attention. Measuring social mindfulness across 31 samples from industrialized countries and regions (n = 8,354), we found considerable variation. Among selected country-level variables, greater social mindfulness was most strongly associated with countries’ better general performance on environmental protection. Together, our findings contribute to the literature on prosociality by targeting the kind of everyday cooperation that is more focused on communicating benevolence than on providing material benefits

    Reply to Komatsu et al.: From local social mindfulness to global sustainability efforts?

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    Komatsu et al. (1) argue that Van Doesum et al. (2) may have overlooked the role of GDP in reporting a positive association between social mindfulness (SoMi) and the Environmental Performance Index (EPI) at country level. Although the relationship between EPI and SoMi is relatively weaker for countries with higher GDP, that does not imply that the overall observed relationship is a statistical artifact. Rather, it implies that GDP may be a moderator of the relationship between EPI and SoMi. The observed correlation is a valid result on average across countries, and the actual effect size would, at least to some degree, depend on GDP

    Functional evolution of ADAMTS genes: Evidence from analyses of phylogeny and gene organization

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    BACKGROUND: The ADAMTS (A Disintegrin-like and Metalloprotease with Thrombospondin motifs) proteins are a family of metalloproteases with sequence similarity to the ADAM proteases, that contain the thrombospondin type 1 sequence repeat motifs (TSRs) common to extracellular matrix proteins. ADAMTS proteins have recently gained attention with the discovery of their role in a variety of diseases, including tissue and blood disorders, cancer, osteoarthritis, Alzheimer's and the genetic syndromes Weill-Marchesani syndrome (ADAMTS10), thrombotic thrombocytopenic purpura (ADAMTS13), and Ehlers-Danlos syndrome type VIIC (ADAMTS2) in humans and belted white-spotting mutation in mice (ADAMTS20). RESULTS: Phylogenetic analysis and comparison of the exon/intron organization of vertebrate (Homo, Mus, Fugu), chordate (Ciona) and invertebrate (Drosophila and Caenorhabditis) ADAMTS homologs has elucidated the evolutionary relationships of this important gene family, which comprises 19 members in humans. CONCLUSIONS: The evolutionary history of ADAMTS genes in vertebrate genomes has been marked by rampant gene duplication, including a retrotransposition that gave rise to a distinct ADAMTS subfamily (ADAMTS1, -4, -5, -8, -15) that may have distinct aggrecanase and angiogenesis functions

    Reply to Nielsen et al.: Social mindfulness is associated with countries' environmental performance and individual environmental concern.

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    Nielsen et al. (1) argue that Van Doesum et al. (2) need to consider three points for their interpretation of a positive association between individual-level social mindfulness (SoMi) and environmental performance (EPI) at the country level (3). The association is weaker when 1) it is controlled for GDP and 2) when the data of three countries are removed; also, 3) the data do not address the association between SoMi and individual-level environmental concern. We discuss these points in turn

    Social mindfulness and prosociality vary across the globe

    Get PDF
    Humans are social animals, but not everyone will be mindful of others to the same extent. Individual differences have been found, but would social mindfulness also be shaped by one’s location in the world? Expecting cross-national differences to exist, we examined if and how social mindfulness differs across countries. At little to no material cost, social mindfulness typically entails small acts of attention or kindness. Even though fairly common, such low-cost cooperation has received little empirical attention. Measuring social mindfulness across 31 samples from industrialized countries and regions (n = 8,354), we found considerable variation. Among selected country-level variables, greater social mindfulness was most strongly associated with countries’ better general performance on environmental protection. Together, our findings contribute to the literature on prosociality by targeting the kind of everyday cooperation that is more focused on communicating benevolence than on providing material benefits

    Reply to Nielsen et al. social mindfulness is associated with countries’ environmental performance and individual environmental concern

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