419 research outputs found
Network formation mechanisms in conjugated microporous polymers
We discuss in detail the mechanism of formation of a highly microporous polymer, CMP-1, formed mainly via Sonogashira–Hagihara coupling. We demonstrate how the microporosity evolves with time, and discuss the importance of alkyne homo-coupling on the microporosity
Searching for z~7.7 Lyman Alpha Emitters in the COSMOS Field with NEWFIRM
The study of Ly-alpha emission in the high-redshift universe is a useful
probe of the epoch of reionization, as the Ly-alpha line should be attenuated
by the intergalactic medium (IGM) at low to moderate neutral hydrogen
fractions. Here we present the results of a deep and wide imaging search for
Ly-alpha emitters in the COSMOS field. We have used two ultra-narrowband
filters (filter width of ~8-9 {\deg}A) on the NEWFIRM camera, installed on the
Mayall 4m telescope at Kitt Peak National Observatory, in order to isolate
Ly-alpha emitters at z = 7.7; such ultra-narrowband imaging searches have
proved to be excellent at detecting Ly-alpha emitters. We found 5-sigma
detections of four candidate Ly-alpha emitters in a survey volume of 2.8 x 10^4
Mpc^3 (total survey area ~760 arcmin^2). Each candidate has a line flux greater
than 8 x 10^-18 erg s^-1 cm^-2. Using these results to construct a luminosity
function and comparing to previously established Ly-alpha luminosity functions
at z = 5.7 and z = 6.5, we find no conclusive evidence for evolution of the
luminosity function between z = 5.7 and z = 7.7. Statistical Monte Carlo
simulations suggest that half of these candidates are real z = 7.7 targets, and
spectroscopic follow-up will be required to verify the redshift of these
candidates. However, our results are consistent with no strong evolution in the
neutral hydrogen fraction of the IGM between z = 5.7 and z = 7.7, even if only
one or two of the z = 7.7 candidates are spectroscopically confirmed.Comment: 29 pages, 5 figures, accepted to ApJ (12/11
A dose ranging trial to optimize the dose of Rifampin in the treatment of tuberculosis
The study was funded by the EDCTP (European & Developing Countries Clinical Trials Partnership), NACCAP (Netherlands-African partnership for Capacity development and Clinical interventions Against Poverty-related diseases) and the Bill & Melinda Gates Foundation.Rationale: Rifampin at a dose of 10 mg/kg was introduced in 1971 based on pharmacokinetic, toxicity and cost considerations. Available data in mice and humans showed that an increase in dose may shorten the duration of tuberculosis treatment. Objectives: To evaluate the safety and tolerability, the pharmacokinetics and the extended early bactericidal activity of increasing doses of rifampin. Methods: Patients with drug-susceptible tuberculosis were enrolled into a control group of 8 patients receiving the standard dose of 10 mg/kg rifampin, followed by consecutive experimental groups with 15 patients each receiving rifampin 20 mg/kg, 25 mg/kg, 30 mg/kg and 35 mg/kg, respectively, for 14 days. In all patients isoniazid, pyrazinamide and ethambutol were added in standard doses for the second 7 days of treatment. Safety, pharmacokinetics of rifampin, and fall in bacterial load were assessed. Measurements and Main Results: Grade 1 and 2 adverse events were equally distributed between the five dose groups; there were 5 grade 3 events of which 1 was a possibly related hepatotoxicity. Areas under the time-concentration curves and peak serum concentrations of rifampin showed a more than proportional increase with dose. The daily fall in bacterial load over 14 days was 0.176, 0.168, 0.167, 0.265, and 0.261 log10CFU/ml sputum in the 10, 20, 25, 30 and 35 mg/kg groups respectively. Conclusions: Two weeks of rifampin up to 35 mg/kg was safe and well tolerated. There was a non-linear increase in exposure to rifampin without an apparent ceiling effect and a greater estimated fall in bacterial load in the higher dosing groups. Clinical trial registration available at www.clinicaltrials.gove, ID NCT01392911.PostprintPeer reviewe
Reclaiming heritage: colourization, culture wars and the politics of nostalgia
This article considers the discursive continuities between a specifically liberal defence of cultural patrimony, evident in the debate over film colourization, and the culture war critique associated with neo-conservatism. It examines how a rhetoric of nostalgia, linked to particular ideas of authenticity,canonicity and tradition,has been mobilized by the right and the left in attempts to stabilize the confguration and perceived transmission of American cultural identity. While different in scale, colourization and multiculturalism were seen to create respective (postmodern) barbarisms against which defenders of culture, heritage and good taste could unite. I argue that in its defence of the ‘classic’ work of art, together with principles of aesthetic distinction and the value of cultural inheritance,the anti-colourization lobby helped enrich and legitimize a discourse of tradition that, at the end of the 1980s, was beginning to reverberate powerfully in the conservative challenge to a ‘crisis’ within higher education and the humanities. This article attempts to complicate the contemporary politics of nostalgia, showing how a defence of cultural patrimony has distinguished major and minor culture wars, engaging left and right quite differently but with similar presuppositions
New insights into North European and North Atlantic surface pressure variability, storminess, and related climatic change since 1830
The authors present initial results of a new pan-European and international storminess since 1800 as interpreted from European and North Atlantic barometric pressure variability (SENABAR) project. This first stage analyzes results of a new daily pressure variability index, dp(abs)24, from long-running meteorological stations in Denmark, the Faroe Islands, Greenland, Iceland, the United Kingdom, and Ireland, some with data from as far back as the 1830s. It is shown that dp(abs)24 is significantly related to wind speed and is therefore a good measure of Atlantic and Northwest European storminess and climatic variations. The authors investigate the temporal and spatial consistency of dp(abs)24, the connection between annual and seasonal dp(abs)24 and the North Atlantic Oscillation Index (NAOI), as well as dp(abs)24 links with historical storm records. The results show periods of relatively high dp(abs)24 and enhanced storminess around 1900 and the early to mid-1990s, and a relatively quiescent period from about 1930 to the early 1960s, in keeping with earlier studies. There is little evidence that the mid- to late nineteenth century was less stormy than the present, and there is no sign of a sustained enhanced storminess signal associated with "global warming." The results mark the first step of a project intending to improve on earlier work by linking barometric pressure data from a wide network of stations with new gridded pressure and reanalysis datasets, GCMs, and the NAOI. This work aims to provide much improved spatial and temporal coverage of changes in European, Atlantic, and global storminess. © 2008 American Meteorological Society
New insights into North European and North Atlantic surface pressure variability, storminess and related climate change since 1830
The authors present initial results of a new pan-European and international storminess since 1800 as interpreted from European and North Atlantic barometric pressure variability (SENABAR) project. This first stage analyzes results of a new daily pressure variability index, dp(abs)24, from long-running meteorological stations in Denmark, the Faroe Islands, Greenland, Iceland, the United Kingdom, and Ireland, some with data from as far back as the 1830s. It is shown that dp(abs)24 is significantly related to wind speed and is therefore a good measure of Atlantic and Northwest European storminess and climatic variations. The authors investigate the temporal and spatial consistency of dp(abs)24, the connection between annual and seasonal dp(abs)24 and the North Atlantic Oscillation Index (NAOI), as well as dp(abs)24 links with historical storm records. The results show periods of relatively high dp(abs)24 and enhanced storminess around 1900 and the early to mid-1990s, and a relatively quiescent period from about 1930 to the early 1960s, in keeping with earlier studies. There is little evidence that the mid- to late nineteenth century was less stormy than the present, and there is no sign of a sustained enhanced storminess signal associated with “global warming.” The results mark the first step of a project intending to improve on earlier work by linking barometric pressure data from a wide network of stations with new gridded pressure and reanalysis datasets, GCMs, and the NAOI. This work aims to provide much improved spatial and temporal coverage of changes in European, Atlantic, and global storminess
The Fourteenth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the extended Baryon Oscillation Spectroscopic Survey and from the second phase of the Apache Point Observatory Galactic Evolution Experiment
The fourth generation of the Sloan Digital Sky Survey (SDSS-IV) has been in
operation since July 2014. This paper describes the second data release from
this phase, and the fourteenth from SDSS overall (making this, Data Release
Fourteen or DR14). This release makes public data taken by SDSS-IV in its first
two years of operation (July 2014-2016). Like all previous SDSS releases, DR14
is cumulative, including the most recent reductions and calibrations of all
data taken by SDSS since the first phase began operations in 2000. New in DR14
is the first public release of data from the extended Baryon Oscillation
Spectroscopic Survey (eBOSS); the first data from the second phase of the
Apache Point Observatory (APO) Galactic Evolution Experiment (APOGEE-2),
including stellar parameter estimates from an innovative data driven machine
learning algorithm known as "The Cannon"; and almost twice as many data cubes
from the Mapping Nearby Galaxies at APO (MaNGA) survey as were in the previous
release (N = 2812 in total). This paper describes the location and format of
the publicly available data from SDSS-IV surveys. We provide references to the
important technical papers describing how these data have been taken (both
targeting and observation details) and processed for scientific use. The SDSS
website (www.sdss.org) has been updated for this release, and provides links to
data downloads, as well as tutorials and examples of data use. SDSS-IV is
planning to continue to collect astronomical data until 2020, and will be
followed by SDSS-V.Comment: SDSS-IV collaboration alphabetical author data release paper. DR14
happened on 31st July 2017. 19 pages, 5 figures. Accepted by ApJS on 28th Nov
2017 (this is the "post-print" and "post-proofs" version; minor corrections
only from v1, and most of errors found in proofs corrected
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