On the puzzling plateau in the specific star formation rate at z=2-7

The observational indications for a constant specific star-formation rate (sSFR) in the redshift range z=2-7 are puzzling in the context of current galaxy-formation models. Despite the tentative nature of the data, their marked conflict with theory motivates a study of the possible implications. The plateau at sSFR ~ 2 Gyr^-1 is hard to reproduce because (a) its level is low compared to the cosmological specific accretion rate at z > 6, (b) it is higher than the latter at z ~ 2, (c) the natural correlation between SFR and stellar mass makes it difficult to manipulate their ratio, and (d) a low SFR at high z makes it hard to produce enough massive galaxies by z ~ 2. Using a flexible semi-analytic model, we explore ad-hoc modifications to the standard physical recipes trying to obey the puzzling observational constraints. Successful models involve non-trivial modifications, such as (a) a suppressed SFR at z > 4 in galaxies of all masses, by enhanced feedback or reduced SFR efficiency, following an initial active phase at z > 7, (b) a delayed gas consumption into stars, allowing the gas that was prohibited from forming stars or ejected at high z to form stars later in more massive galaxies, and (c) enhanced growth of massive galaxies, in terms of either faster assembly or more efficient starbursts in mergers, or by efficient star formation in massive haloes.Comment: 17 pages, 11 figures. MNRAS accepted. References added, small changes to text after referee report. Results and conclusions unchange

The state of the Martian climate

60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes

Phox2b function in the enteric nervous system is conserved in zebrafish and is sox10-dependent

Zebrafish lacking functional sox10 have defects in non-ectomesenchymal neural crest derivatives including the enteric nervous system (ENS) and as such provide an animal model for human Waardenburg Syndrome IV. Here, we characterize zebrafish phox2b as a functionally conserved marker of the developing ENS. We show that morpholino-mediated knockdown of Phox2b generates fish modeling Hirschsprung disease. Using markers, including phox2b, we investigate the ontogeny of the sox10 ENS phenotype. As previously shown for melanophore development, ENS progenitor fate specification fails in these mutant fish. However, in addition, we trace back the sox10 mutant ENS defect to an even earlier time point, finding that most neural crest cells fail to migrate ventrally to the gut primordium. (c) 2005 Elsevier Ireland Ltd. All rights reserved.Medical Research Council [G0300415

Assessing the co-occurrence of intimate partner violence domains across the life-course: relating typologies to mental health

Background: The inter-generational transmission of violence (ITV) hypothesis and polyvictimisation have been studied extensively. The extant evidence suggests that individuals from violent families are at increased risk of subsequent intimate partner violence (IPV) and that a proportion of individuals experience victimisation across multiple rather than single IPV domains. Both ITV and polyvictimisation are shown to increase the risk of psychiatric morbidity, alcohol use, and anger expression. Objective: The current study aimed to 1) ascertain if underlying typologies of victimisation across the life-course and over multiple victimisation domains were present and 2) ascertain if groupings differed on mean scores of posttraumatic stress disorder (PTSD), depression, alcohol use, and anger expression. Method: University students (N=318) were queried in relation to victimisation experiences and psychological well-being. Responses across multiple domains of IPV spanning the life-course were used in a latent profile analysis. ANOVA was subsequently used to determine if profiles differed in their mean scores on PTSD, depression, alcohol use, and anger expression. Results: Three distinct profiles were identified; one of which comprised individuals who experienced “life-course polyvictimisation,” another showing individuals who experienced “witnessing parental victimisation,” and one which experienced “psychological victimisation only.” Life-course polyvictims scored the highest across most assessed measures. Conclusion: Witnessing severe physical aggression and injury in parental relationships as a child has an interesting impact on the ITV into adolescence and adulthood. Life-course polyvictims are shown to experience increased levels of psychiatric morbidity and issues with alcohol misuse and anger expression

Pan-cancer analysis of whole genomes

Cancer is driven by genetic change, and the advent of massively parallel sequencing has enabled systematic documentation of this variation at the whole-genome scale(1-3). Here we report the integrative analysis of 2,658 whole-cancer genomes and their matching normal tissues across 38 tumour types from the Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium of the International Cancer Genome Consortium (ICGC) and The Cancer Genome Atlas (TCGA). We describe the generation of the PCAWG resource, facilitated by international data sharing using compute clouds. On average, cancer genomes contained 4-5 driver mutations when combining coding and non-coding genomic elements; however, in around 5% of cases no drivers were identified, suggesting that cancer driver discovery is not yet complete. Chromothripsis, in which many clustered structural variants arise in a single catastrophic event, is frequently an early event in tumour evolution; in acral melanoma, for example, these events precede most somatic point mutations and affect several cancer-associated genes simultaneously. Cancers with abnormal telomere maintenance often originate from tissues with low replicative activity and show several mechanisms of preventing telomere attrition to critical levels. Common and rare germline variants affect patterns of somatic mutation, including point mutations, structural variants and somatic retrotransposition. A collection of papers from the PCAWG Consortium describes non-coding mutations that drive cancer beyond those in the TERT promoter(4); identifies new signatures of mutational processes that cause base substitutions, small insertions and deletions and structural variation(5,6); analyses timings and patterns of tumour evolution(7); describes the diverse transcriptional consequences of somatic mutation on splicing, expression levels, fusion genes and promoter activity(8,9); and evaluates a range of more-specialized features of cancer genomes(8,10-18).Peer reviewe

Fifty shades of green: How microfoundations of sustainability dynamic capabilities vary across organizational contexts

Because making progress on sustainability‐related challenges will require organizational change for most organizations, understanding sustainability dynamic capabilities is of utmost importance. In this theoretical paper, we aim to identify the microfoundations of such sustainability dynamic capabilities on the one hand but, consistent with recent work in this research stream, we do so in a way that is sensitive to the dynamism of the organizational environment. We propose that the microfoundations of sustainability dynamic capabilities will take different forms in different contexts. We contrast moderately dynamic contexts characterized by frequent yet relatively predictable change with highly dynamic contexts in which changes are rapid and not predictable. Achieving sustainability in these different types of contexts poses different types of challenges, relies on different forms of employee behaviors, and is consequently enabled by different individual‐level characteristics and different organizational practices and processes. Our paper calls for a more serious consideration of context in investigating how employees' behaviors can affect sustainability at the organizational level, and outlines the implications for organizational policy and practice. We explore directions for future interdisciplinary research on sustainability that focuses on individuals and their interactions while also taking the environment within which organizations operate into account

Beijing Time

“Where is the market?” inquires the tourist one dark, chilly morning. “Follow the ghosts,” responds the taxi driver, indicating a shadowy parade of overloaded tricycles. “It’s not called the ghost market for nothing!” And indeed, Beijing is nothing if not haunted. Among the soaring skyscrapers, choking exhaust fumes, nonstop traffic jams, and towering monuments, one discovers old Beijing—newly styled, perhaps, but no less present and powerful than in its ancient incarnation. Beijing Time conducts us into this mysterious world, at once familiar and yet alien to the outsider. The ancient Chinese understood the world as enchanted, its shapes revealing the mythological order of the universe. In the structure and detail of Tian’anmen Square, the authors reveal the city as a whole. In Beijing no pyramids stand as proud remnants of the past; instead, the entire city symbolizes a vibrant civilization. From Tian’anmen Square, we proceed to the neighborhoods for a glimpse of local color—from the granny and the young police officer to the rag picker and the flower vendor. Wandering from the avant-garde art market to the clock towers, from the Monumental Axis to Mao’s Mausoleum, the book allows us to peer into the lives of Beijingers, the rules and rituals that govern their reality, and the mythologies that furnish their dreams. Deeply immersed in the culture, everyday and otherworldly, this anthropological tour, from ancient cosmology to Communist kitsch, allows us to see as never before how the people of Beijing—and China—work and live

Beijing Time

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