778 research outputs found
Our Moment of Truth: The Social Contract Realized?
Much has changed in the two decades since I (JL) proposed that scientists should re-examine their obligations to society in order to serve society better. Today, more environmental scientists are actively sharing their science broadly, conducting use-inspired science (sensu Stokes) in addition to basic science, engaging with society, and crafting solutions to problems not just diagnosing themāall very welcome and exciting developments. For the most part, however, environmental scientists have taken on these extra duties because they believed it was the right thing to do and despite the considerable impediments that exist within academia. But make no mistake, the culture of academia continues to impede progress. As a result, although the above actions have had demonstrable effect, their collective impact falls far short of what is needed if society is to tackle effectively the disruption underway due to climate change, ocean acidification, biodiversity loss, pandemics, and more. Actions by individuals can take us only so far. To truly help society meet its grand challenges, environmental scientists must now make a quantum leap in engagement with society. It is time for strategic, collective action to change the culture of academia and create the enabling conditions for science to serve society better
New Results from the Solar Maximum Mission/Bent Crystal Spectrometer
The Bent Crystal Spectrometer (BCS) onboard the NASA Solar Maximum Mission was part of the X-ray Polychromator, which observed numerous flares and bright active regions from February to November 1980, when operation was suspended as a result of the failure of the spacecraft fine-pointing system. Observations resumed following the Space Shuttle SMM Repair Mission in April 1984 and continued until November 1989. BCS spectra have been widely used in the past to obtain temperatures, emission measures, and turbulent and bulk flows during flares, as well as element abundances. Instrumental details including calibration factors not previously published are given here, and the in-orbit performance of the BCS is evaluated. Some significant changes during the mission are described, and recommendations for future instrumentation are made. Using improved estimates for the instrument parameters and operational limits, it is now possible to obtain de-convolved calibrated spectra that show finer detail than before, providing the means for improved interpretation of the physics of the emitting plasmas. The results indicate how historical archived data can be re-used to obtain enhanced and new, scientifically valuable results
A Unique Resource for Solar Flare Diagnostic Studies: the SMM Bent Crystal Spectrometer
The {\em Bent Crystal Spectrometer}\/ (BCS) on the NASA {\em Solar Maximum
Mission}\/ spacecraft observed the X-ray spectra of numerous solar flares
during the periods 1980 February to November and 1984~--~1989. The instrument,
the first of its kind to use curved crystal technology, observed the resonance
lines of He-like Ca (\caxix) and Fe (\fexxv) and neighboring satellite lines,
allowing the study of the rapid evolution of flare plasma temperature,
turbulence, mass motions etc. To date there has not been a solar X-ray
spectrometer with comparable spectral and time resolution, while subsequent
solar cycles have delivered far fewer and less intense flares. The BCS data
archive thus offers an unparalleled resource for flare studies. A recent
re-assessment of the BCS calibration and its operations is extended here by
using data during a spacecraft scan in the course of a flare on 1980 November~6
that highlights small deformations in the crystal curvature of the important
channel~1 (viewing lines of \caxix\ and satellites). The results explain
long-standing anomalies in spectral line ratios which have been widely
discussed in the past. We also provide an in-flight estimation of the BCS
collimator field of view which improves the absolute intensity calibration of
the BCS. The BCS channel~1 background is shown to be entirely due to solar
continuum radiation, confirming earlier analyses implying a time-variable flare
abundance of Ca. We suggest that BCS high-resolution \caxix\ and \fexxv\ line
spectra be used as templates for the analysis of X-ray spectra of non-solar
sources.Comment: To be published, Astrophysical Journa
Cultural Influences on African Migrant Pregnant and Postnatal Womenās Dietary Behaviours and Nutrition Support Needs in the UK
UCL Department of Science and Technology Studies submission of evidence to the House of Commons Science and Technology Select Committee inquiry into science communication
Tunable control of the hydrophilicity and wettability of conjugated polymers by a postpolymerization modification approach.
A facile method to prepare hydrophilic polymers by a postpolymerization nucleophillic aromatic substitution reaction of fluoride on an emissive conjugated polymer (CP) backbone is reported. Quantitative functionalization by a series of monofunctionalized ethylene glycol oligomers, from dimer to hexamer, as well as with high molecular weight polyethylene glycol is demonstrated. The length of the ethylene glycol sidechains is shown to have a direct impact on the surface wettability of the polymer, as well as its solubility in polar solvents. However, the energetics and band gap of the CPs remain essentially constant. This method therefore allows an easy way to modulate the wettability and solubility of CP materials for a diverse series of applications
Normative puzzles for local government: Managing the introduction of singleāhanded care in England
A crisis in social care is apparent across the developed world as ageing populations put unprecedented demand on understaffed social care workforces. A recent popular response to this ācare crisisā within the UK involves the āinnovationā of singleāhanded care (SHC). SHC involves a care package with two or more homecare workers being reduced to one worker using advanced equipment and new moving and handling techniques. In this article, we explore how SHC is rendered in 245 documents from 52 local authorities in England. Using Actor Network Theory as an interpretative lens, we suggest documents attempt to satisfy three āduties of careā: to the individual wellbeing of citizens, morally and fiscally to the collective and to innovation. Each appeal to different stakeholder groups necessary for SHC to work, but the combination of duties can pose problems in enabling coherent stories of SHC. Duties can be kept apart in different documents, but at times they must be brought together in certain textual spaces to enact SHC as a coherent enterprise. Here, the potential tensions that emerge are routinely orientated to as (merely) problems of process that can and should be managed in and through a more refined approach to change management
The interview as narrative ethnography : seeking and shaping connections in qualitative research.
Acts of counter-subjectification in qualitative research are always present but are often submerged in accounts that seek to locate the power of subjectification entirely with the researcher. This is particularly so when talking to people about sensitive issues. Based on an interview-based study of infertility and reproductive disruption among British Pakistanis in Northeast England, we explore how we, as researchers, sought and were drawn into various kinds of connections with the study participants; connections that were actively and performatively constructed through time. The three of us that conducted interviews are all female academics with Ph.Ds in anthropology, but thereafter our backgrounds, life stories and experiences diverge in ways that intersected with those of our informants in complex and shifting ways. We describe how these processes shaped the production of narrative accounts and consider some of the associated analytical and ethical implications
Mechanism and function of Vav1 localisation in TCR signalling
The antigen-specific binding of T cells to antigen presenting cells results in recruitment of signalling proteins to microclusters at the cell-cell interface known as the immunological synapse (IS). The Vav1 guanine nucleotide exchange factor plays a critical role in T cell antigen receptor (TCR) signalling, leading to the activation of multiple pathways. We now show that it is recruited to microclusters and to the IS in primary CD4+ and CD8+ T cells. Furthermore, we show that this recruitment depends on the SH2 and C-terminal SH3 (SH3B) domains of Vav1, and on phosphotyrosines 112 and 128 of the SLP76 adaptor protein. Biophysical measurements show that Vav1 binds directly to these residues on SLP76 and that efficient binding depends on the SH2 and SH3B domains of Vav1. Finally, we show that the same two domains are critical for the phosphorylation of Vav1 and its signalling function in TCR-induced calcium flux. We propose that Vav1 is recruited to the IS by binding to SLP76 and that this interaction is critical for the transduction of signals leading to calcium flux
Avoidance as a strategy of (not) coping: qualitative interviews with carers of Huntington's Disease patients
Peer reviewedPublisher PD
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