DES14X3taz: A Type I Superluminous Supernova Showing a Luminous, Rapidly Cooling Initial Pre-peak Bump

We present DES14X3taz, a new hydrogen-poor superluminous supernova (SLSN-I) discovered by the Dark Energy Survey (DES) supernova program, with additional photometric data provided by the Survey Using DECam for Superluminous Supernovae. Spectra obtained using Optical System for Imaging and low-Intermediate-Resolution Integrated Spectroscopy on the Gran Telescopio CANARIAS show DES14X3taz is an SLSN-I at z = 0.608. Multi-color photometry reveals a double-peaked light curve: a blue and relatively bright initial peak that fades rapidly prior to the slower rise of the main light curve. Our multi-color photometry allows us, for the first time, to show that the initial peak cools from 22,000 to 8000 K over 15 rest-frame days, and is faster and brighter than any published core-collapse supernova, reaching 30% of the bolometric luminosity of the main peak. No physical 56Ni-powered model can fit this initial peak. We show that a shock-cooling model followed by a magnetar driving the second phase of the light curve can adequately explain the entire light curve of DES14X3taz. Models involving the shock-cooling of extended circumstellar material at a distance of 400  are preferred over the cooling of shock-heated surface layers of a stellar envelope. We compare DES14X3taz to the few double-peaked SLSN-I events in the literature. Although the rise times and characteristics of these initial peaks differ, there exists the tantalizing possibility that they can be explained by one physical interpretation.

A comparison of different pre-lysis methods and extraction kits for recovery of Stretococcus agalacticae (Lancefield group B Streptococcus) DNA from whole blood

Sub-optimal recovery of bacterial DNA from whole blood samples can limit the sensitivity of molecular assays to detect pathogenic bacteria. We compared 3 different pre-lysis protocols (none, mechanical pre-lysis and achromopeptidasepre-lysis) and 5 commercially available DNA extraction platforms for direct detection of Group B Streptococcus (GBS) in spiked whole blood samples, without enrichment culture. DNA was extracted using the QIAamp Blood Mini kit (Qiagen), UCP Pathogen Mini kit (Qiagen), QuickGene DNA Whole Blood kit S (Fuji), Speed Xtract Nucleic Acid Kit 200 (Qiagen) and MagNA Pure Compact Nucleic Acid Isolation Kit I (Roche Diagnostics Corp). Mechanical pre-lysis increased yields of bacterial genomic DNA by 51.3 fold (95% confidence interval; 31.6–85.1, p < 0.001) and pre-lysis with achromopeptidase by 6.1 fold (95% CI; 4.2–8.9, p < 0.001), compared with no pre-lysis. Differences in yield dueto pre-lysis were 2–3 fold larger than differences in yield between extraction methods. Including a pre-lysis step can improve the limits of detection of GBS using PCR or other molecular methods without need for culture.

The VLT-FLAMES Tarantula Survey. XV. VFTS 822: A candidate Herbig B[e] star at low metallicity

We report the discovery of the B[e] star VFTS 822 in the 30 Doradus star-forming region of the Large Magellanic Cloud, classified by optical spectroscopy from the VLT-FLAMES Tarantula Survey and complementary infrared photometry. VFTS 822 is a relatively low-luminosity (log L = 4.04 ± 0.25 Lb>·b>) B8[e] star. In this Letter, we evaluate the evolutionary status of VFTS 822 and discuss its candidacy as a Herbig B[e] star. If the object is indeed in the pre-main sequence phase, it would present an exciting opportunity to spectroscopically measure mass accretion rates at low metallicity, to probe the effect of metallicity on accretion rates. 

Emergence of episodic future though in pre-school aged children

Three experiments examined the development of episodic future thinking: the ability to think ahead about novel future situations (Atance & O’Neill, 2001). Each experiment used three novel tasks, similar to the Blow Football task used by Russell, Alexis, and Clayton (2010). In each, there was a different table top with two sides. Children played a game on one side of a table, and then were asked to choose a tool to play with a similar game on the other side of the table the next day. For example, children used a toy fishing rod to catch magnetic fish on one side of the table; playing the same game from the other side of the table required a different type of fishing rod. At test, children chose between 2 or 3 tools: a) the tool they used today, b) the tool suitable for the other side (correct) and c) a distractor tool which was not suitable for either side. In Experiment 1, 24 four-year-olds selected 1 out of 2 tools for tomorrow. Children selected the correct item above chance level in all tasks (p < 0.001). In Experiment 2, in which children were not allowed to look at the apparatus when choosing, 21 three-year olds selected 1 out of 2 tools for tomorrow. This group also selected the right tool above chance level in all tasks (p < 0.001).The results of Experiments 1 and 2 imply that 3- and 4-year olds might indeed show episodic future foresight. However, they could have also selected the right tool by default. To control for this, a third tool distractor was introduced in Experiment 3. This time, 3-4 year olds did not perform above chance levels, suggesting that there is an alternative explanation as to why they performed so well in the previous two experiments.

Variation in pre-PCR processing of FFPE samples leads to discrepancies in BRAF and EGFR mutation detection: a diagnostic RING trial.

AIMS: Mutation detection accuracy has been described extensively; however, it is surprising that pre-PCR processing of formalin-fixed paraffin-embedded (FFPE) samples has not been systematically assessed in clinical context. We designed a RING trial to (i) investigate pre-PCR variability, (ii) correlate pre-PCR variation with EGFR/BRAF mutation testing accuracy and (iii) investigate causes for observed variation. METHODS: 13 molecular pathology laboratories were recruited. 104 blinded FFPE curls including engineered FFPE curls, cell-negative FFPE curls and control FFPE tissue samples were distributed to participants for pre-PCR processing and mutation detection. Follow-up analysis was performed to assess sample purity, DNA integrity and DNA quantitation. RESULTS: Rate of mutation detection failure was 11.9%. Of these failures, 80% were attributed to pre-PCR error. Significant differences in DNA yields across all samples were seen using analysis of variance (p

National incomes and economic growth in pre-industrial Europe: insights from recent research

Pessimistic Malthusian verdicts on the capacity of pre-industrial European economies to sustain a degree of real economic growth under conditions of population growth are challenged using current reconstructions of urbanisation ratios, the real wage rates of building and agricultural labourers, and GDP per capita estimated by a range of methods. Economic growth is shown to have outpaced population growth and raised GDP per capita to in excess of $1,500 (1990 $ international at PPP) in Italy during its twelfth- and thirteenth-century commercial revolution, Holland during its fifteenth- and sixteenth-century golden age, and England during the seventeenth- and eighteenth-century runup to its industrial revolution. During each of these Smithian growth episodes expanding trade and commerce sustained significant output and employment growth in the manufacturing and service sectors. These positive developments were not necessarily reflected by trends in real wage rates for the latter were powerfully influenced by associated changes in relative factor prices and the per capita supply of labour as workers varied the length of the working year in order to consume either more leisure or more goods. The scale of the divergence between trends in real wage rates and GDP per capita nevertheless varied a great deal between countries for reasons which have yet to be adequately explained.