676 research outputs found
Tonal prisms: iterated quantization in chromatic tonality and Ravel's 'Ondine'
The mathematics of second-order maximal evenness has far-reaching potential for application in music analysis. One of its assets is its foundation in an inherently continuous conception of pitch, a feature it shares with voice-leading geometries. This paper reformulates second-order maximal evenness as iterated quantization in voice-leading spaces, discusses the implications of viewing diatonic triads as second-order maximally even sets for the understanding of nineteenth-century modulatory schemes, and applies a second-order maximally even derivation of acoustic collections in an in-depth analysis of Ravel's ‘Ondine’. In the interaction between these two very different applications, the paper generalizes the concepts and analytical methods associated with iterated quantization and also pursues a broader argument about the mutual dependence of mathematical music theory and music analysis.Accepted manuscrip
Ground-based detection of a vibration-rotation line of HD in Orion
The v =1-0 R(5) line of HD at 2.46um has been detected at the position of
brightest line emission of shocked H2 in the Orion Molecular Cloud. The flux in
this HD line, when compared to that of the previously detected HD 0--0 R(5)
line at 19.43um, suggests that, like the v=1 levels of H2, the v=1 levels of HD
are populated in LTE, despite their much higher rates of spontaneous emission
compared to H2. The higher than expected population of vibrationally excited HD
may be due to chemical coupling of HD to H2 via the reactive collisions HD + H
H2 + D in the shocked gas. The deuterium abundance implied by the
strengths of these lines relative to those of H2 is (5.1 pm 1.9 x 10^-6.Comment: 9 pages, 2 figures, Proceedings of the Conference on "Deuterium in
the Universe," to be published in Planetary and Space Science
A daily, 1 km resolution data set of downscaled Greenland ice sheet surface mass balance (1958–2015)
This study presents a data set of daily, 1 km resolution Greenland ice sheet (GrIS) surface mass balance (SMB) covering the period 1958–2015. Applying corrections for elevation, bare ice albedo and accumulation bias, the high-resolution product is statistically downscaled from the native daily output of the polar regional climate model RACMO2.3 at 11 km. The data set includes all individual SMB components projected to a down-sampled version of the Greenland Ice Mapping Project (GIMP) digital elevation model and ice mask. The 1 km mask better resolves narrow ablation zones, valley glaciers, fjords and disconnected ice caps. Relative to the 11 km product, the more detailed representation of isolated glaciated areas leads to increased precipitation over the southeastern GrIS. In addition, the downscaled product shows a significant increase in runoff owing to better resolved low-lying marginal glaciated regions. The combined corrections for elevation and bare ice albedo markedly improve model agreement with a newly compiled data set of ablation measurements
Hypoxia-induced nitric oxide production and tumour perfusion is inhibited by pegylated arginine deiminase (ADI-PEG20).
The hypoxic tumour microenvironment represents an aggressive, therapy-resistant compartment. As arginine is required for specific hypoxia-induced processes, we hypothesised that arginine-deprivation therapy may be useful in targeting hypoxic cancer cells. We explored the effects of the arginine-degrading agent ADI-PEG20 on hypoxia-inducible factor (HIF) activation, the hypoxia-induced nitric oxide (NO) pathway and proliferation using HCT116 and UMUC3 cells and xenografts. The latter lack argininosuccinate synthetase (ASS1) making them auxotrophic for arginine. In HCT116 cells, ADI-PEG20 inhibited hypoxic-activation of HIF-1α and HIF-2α, leading to decreased inducible-nitric oxide synthase (iNOS), NO-production, and VEGF. Interestingly, combining hypoxia and ADI-PEG20 synergistically inhibited ASS1. ADI-PEG20 inhibited mTORC1 and activated the unfolded protein response providing a mechanism for inhibition of HIF and ASS1. ADI-PEG20 inhibited tumour growth, impaired hypoxia-associated NO-production, and decreased vascular perfusion. Expression of HIF-1α/HIF-2α/iNOS and VEGF were reduced, despite an increased hypoxic tumour fraction. Similar effects were observed in UMUC3 xenografts. In summary, ADI-PEG20 inhibits HIF-activated processes in two tumour models with widely different arginine biology. Thus, ADI-PEG20 may be useful in the clinic to target therapy-resistant hypoxic cells in ASS1-proficient tumours and ASS1-deficient tumours.Thanks to Dr John Bomalaski, (Polaris Pharmaceuticals, Inc) for supplying the ADI-PEG20, to Dr Simon S Hoer for useful discussions and to members of Histopathology/ISH (CRUK Cambridge Institute, UK) for IHC and imaging assistance. This work was supported by the Wellcome Trust and the NIHR Cambridge Biomedical Research Centre Senior Investigator Awards (to P.H.M., supporting N.B.), EU FP7 Metoxia Grant agreement no. 222741 (to P.H.M., supporting G.C.), UCL Cancer Research UK Centre (to M.R.), King’s College London and UCL Comprehensive Cancer Imaging Centre, Cancer Research UK and EPSRC in association with the Medical Research Council (MRC), the DoH (England: to R.B.P.), MRC Cancer Unit Core Funding (to C.F., supporting E.G.).This is the final version of the article. It first appeared from Nature Publishing Group via http://dx.doi.org/10.1038/srep2295
A daily, 1 km resolution data set of downscaled Greenland ice sheet surface mass balance (1958–2015)
This study presents a data set of daily, 1 km resolution Greenland ice sheet (GrIS) surface mass balance (SMB) covering the period 1958–2015. Applying corrections for elevation, bare ice albedo and accumulation bias, the high-resolution product is statistically downscaled from the native daily output of the polar regional climate model RACMO2.3 at 11 km. The data set includes all individual SMB components projected to a down-sampled version of the Greenland Ice Mapping Project (GIMP) digital elevation model and ice mask. The 1 km mask better resolves narrow ablation zones, valley glaciers, fjords and disconnected ice caps. Relative to the 11 km product, the more detailed representation of isolated glaciated areas leads to increased precipitation over the southeastern GrIS. In addition, the downscaled product shows a significant increase in runoff owing to better resolved low-lying marginal glaciated regions. The combined corrections for elevation and bare ice albedo markedly improve model agreement with a newly compiled data set of ablation measurements
The development of a program engagement theory for group offending behavior programs
Offender engagement in group offending behavior programs is poorly understood and under-theorized. In addition, there is no research on facilitators’ engagement. This paper presents the first ever theory to address this gap. A Program Engagement Theory (PET) was derived from a constructivist grounded theory analysis, that accounts for both facilitators’ and offenders’ engagement in group offending behavior programs. Interviews and session observations were used to collect data from 23 program facilitators and 28 offenders (group members). The analysis revealed that group members’ engagement involved shared identities and moving on as a group. In turn, this was dependent on facilitators personalising treatment frameworks and establishing a hook in order to help group members move on. The PET emphasises the importance of considering change during treatment as a process rather than simply a program outcome. Solution-focused programs were more conducive to engagement and the change process than offence-focused programs
Elevation change of the Greenland Ice Sheet due to surface mass balance and firn processes, 1960–2014
© The Author(s), 2015. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in The Cryosphere 9 (2015): 2009-2025, doi:10.5194/tc-9-2009-2015.Observed changes in the surface elevation of the Greenland Ice Sheet are caused by ice dynamics, basal elevation change, basal melt, surface mass balance (SMB) variability, and by compaction of the overlying firn. The last two contributions are quantified here using a firn model that includes compaction, meltwater percolation, and refreezing. The model is forced with surface mass fluxes and temperature from a regional climate model for the period 1960–2014. The model results agree with observations of surface density, density profiles from 62 firn cores, and altimetric observations from regions where ice-dynamical surface height changes are likely small. In areas with strong surface melt, the firn model overestimates density. We find that the firn layer in the high interior is generally thickening slowly (1–5 cm yr−1). In the percolation and ablation areas, firn and SMB processes account for a surface elevation lowering of up to 20–50 cm yr−1. Most of this firn-induced marginal thinning is caused by an increase in melt since the mid-1990s and partly compensated by an increase in the accumulation of fresh snow around most of the ice sheet. The total firn and ice volume change between 1980 and 2014 is estimated at −3295 ± 1030 km3 due to firn and SMB changes, corresponding to an ice-sheet average thinning of 1.96 ± 0.61 m. Most of this volume decrease occurred after 1995. The computed changes in surface elevation can be used to partition altimetrically observed volume change into surface mass balance and ice-dynamically related mass changes.P. Kuipers Munneke received financial
support from the Netherlands Polar Programme (NPP) of the
Netherlands Institute for Scientific Research (NWO). ECMWF at
Reading (UK) is acknowledged for use of the Cray supercomputing
system. The J. E. Box contribution is supported by
Det Frie Forskningsråd grant 4002-00234 and Geocenter Denmark
Spatiotemporal interpolation of elevation changes derived from satellite altimetry for Jakobshavn Isbræ, Greenland
Estimation of ice sheet mass balance from satellite altimetry requires interpolation of point-scale elevation change (dHdt) data over the area of interest. The largest dHdt values occur over narrow, fast-flowing outlet glaciers, where data coverage of current satellite altimetry is poorest. In those areas, straightforward interpolation of data is unlikely to reflect the true patterns of dHdt. Here, four interpolation methods are compared and evaluated over Jakobshavn Isbr, an outlet glacier for which widespread airborne validation data are available from NASAs Airborne Topographic Mapper (ATM). The four methods are ordinary kriging (OK), kriging with external drift (KED), where the spatial pattern of surface velocity is used as a proxy for that of dHdt, and their spatiotemporal equivalents (ST-OK and ST-KED)
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