187 research outputs found
Forming a Government in a Hung Parliament: the UK's Recognition rules in Comparative Context
This paper considers government formation in a hung parliament, in which more than one potential government is viable. In such situations, constitutional rules and conventions, which are referred to in the academic literature as recognition rules, guide which actors will be asked to form the government (i.e. to act as the formateur) and in what order. The academic literature identifies six possible recognition rules to guide who should be asked to form a government. These are the majority principle, the continuation rule, and the gravitational, plurality, fault and plebiscitary principles. Recognition rules have political consequences. They may influence which parties form the government, and what policies are then implemented. To protect the Monarchy and its political impartiality, the recognition rules need to be clear, democratic and effective. In the past the UK has applied a range of different conventions and principles which are potentially contradictory, and do not all follow an equally democratic logic. This can jeopardise the Monarch's role in the government formation process. An alternative to the use of ex ante recognition rules is a vote in parliament to nominate the new Prime Minister (in the form of a request to the Monarch). This would protect the Monarchy and its political impartiality by separating the political choice of a formateur (made by parliament) from the formal act of appointing the formateur, made by the Monarch. Parliament could choose a formateur by directly voting on the candidates nominated by political parties, as happens in other European countries, and in Scotland and Wales. Rules are also needed to terminate a government formation process which has become gridlocked. The UK could adopt the 28 day time limit which applies in Scotland
A REVIEW OF CHALLENGES IN ASSESSMENT AND FORECASTING OF WIND ENERGY RESOURCES
The main issues related to assessment and forecasting of the wind and wind energy have been reviewed. These include the limitations and advantages of wind forecasting and assessment of the wind power density, especially considering trends of increasing penetration of wind-generated power into the utility grid and storage of wind-generated power. Accurate forecasting of the wind power density over a large range of spatial and temporal scales is a critical
issue for planning and operations of wind farms. A review of various prediction tools, from simple statistical models to highly complex numerical techniques, was performed for this purpose. The influence of wind variability, atmospheric stability, turbulence, and the low-level jets on wind power density are elaborated on in detail. Furthermore, prediction and assessment of future wind energy resources and their economic implications as well as environmental concerns such as birds’ habitats and routes, viewpoint aesthetics, and noise are also discussed in this study. Some climate projection studies indicate minor changes in the wind resources comparable
to differences in global models results while others argue that the wind resources will be reduced due to global warming and they call for harvesting wind energy at the maximum rate as soon as possible
Optical performance of the JWST MIRI flight model: characterization of the point spread function at high-resolution
The Mid Infra Red Instrument (MIRI) is one of the four instruments onboard
the James Webb Space Telescope (JWST), providing imaging, coronagraphy and
spectroscopy over the 5-28 microns band. To verify the optical performance of
the instrument, extensive tests were performed at CEA on the flight model (FM)
of the Mid-InfraRed IMager (MIRIM) at cryogenic temperatures and in the
infrared. This paper reports on the point spread function (PSF) measurements at
5.6 microns, the shortest operating wavelength for imaging. At 5.6 microns the
PSF is not Nyquist-sampled, so we use am original technique that combines a
microscanning measurement strategy with a deconvolution algorithm to obtain an
over-resolved MIRIM PSF. The microscanning consists in a sub-pixel scan of a
point source on the focal plane. A data inversion method is used to reconstruct
PSF images that are over-resolved by a factor of 7 compared to the native
resolution of MIRI. We show that the FWHM of the high-resolution PSFs were
5-10% wider than that obtained with Zemax simulations. The main cause was
identified as an out-of-specification tilt of the M4 mirror. After correction,
two additional test campaigns were carried out, and we show that the shape of
the PSF is conform to expectations. The FWHM of the PSFs are 0.18-0.20 arcsec,
in agreement with simulations. 56.1-59.2% of the total encircled energy
(normalized to a 5 arcsec radius) is contained within the first dark Airy ring,
over the whole field of view. At longer wavelengths (7.7-25.5 microns), this
percentage is 57-68%. MIRIM is thus compliant with the optical quality
requirements. This characterization of the MIRIM PSF, as well as the
deconvolution method presented here, are of particular importance, not only for
the verification of the optical quality and the MIRI calibration, but also for
scientific applications.Comment: 13 pages, submitted to SPIE Proceedings vol. 7731, Space Telescopes
and Instrumentation 2010: Optical, Infrared, and Millimeter Wav
Primary and secondary eclipse spectroscopy with JWST: exploring the exoplanet parameter space
Eclipse exoplanet spectroscopy has yielded detection of H_2O, CH_4, CO_2 and
CO in the atmosphere of hot jupiters and neptunes. About 40 large terrestrial
planets are announced or confirmed, two of which are transiting, and another
deemed habitable. Hence the potential for eclipse spectroscopy of terrestrial
planets with James Webb Space Telescope (JWST) has become an active field of
study. We explore the parameter space (type of stars, planet orbital periods
and types, and instruments/wavelengths) in terms of the signal-to-noise ratio
(S/N) achievable on the detection of spectroscopic features. We use analytic
formula and model data for both the astrophysical scene and the instrument, to
plot S/N contour maps, while indicating how the S/N scales with the fixed
parameters. We systematically compare stellar photon noise-only figures with
ones including detailed instrumental and zodiacal noises. Likelihood of
occurring targets is based both on model and catalog star population of the
solar neighborhood. The 9.6 micron ozone band is detectable (S/N = 3) with
JWST, for a warm super-earth 6.7 pc away, using ~2% of the 5-year nominal
mission time (summing observations, M4V and lighter host star for primary
eclipses, M5V for secondary). If every star up to this mass limit and distance
were to host a habitable planet, there should be statistically ~1 eclipsing
case. Investigation of systematic noises in the co-addition of 5 years worth-,
tens of days separated-, hours-long observations is critical, complemented by
dedicated characterisation of the instruments, currently in integration phase.
The census of nearby transiting habitable planets must be complete before the
beginning of science operations.Comment: Accepted for publication in A&A, 16 pages, 19 figure
Evolution of the Habitable Zone and Search for Life Around Giant Stars Part II: Feasibility with Darwin/TPF
SPECULOOS exoplanet search and its prototype on TRAPPIST
One of the most significant goals of modern science is establishing whether
life exists around other suns. The most direct path towards its achievement is
the detection and atmospheric characterization of terrestrial exoplanets with
potentially habitable surface conditions. The nearest ultracool dwarfs (UCDs),
i.e. very-low-mass stars and brown dwarfs with effective temperatures lower
than 2700 K, represent a unique opportunity to reach this goal within the next
decade. The potential of the transit method for detecting potentially habitable
Earth-sized planets around these objects is drastically increased compared to
Earth-Sun analogs. Furthermore, only a terrestrial planet transiting a nearby
UCD would be amenable for a thorough atmospheric characterization, including
the search for possible biosignatures, with near-future facilities such as the
James Webb Space Telescope. In this chapter, we first describe the physical
properties of UCDs as well as the unique potential they offer for the detection
of potentially habitable Earth-sized planets suitable for atmospheric
characterization. Then, we present the SPECULOOS ground-based transit survey,
that will search for Earth-sized planets transiting the nearest UCDs, as well
as its prototype survey on the TRAPPIST telescopes. We conclude by discussing
the prospects offered by the recent detection by this prototype survey of a
system of seven temperate Earth-sized planets transiting a nearby UCD,
TRAPPIST-1.Comment: Submitted as a chapter in the "Handbook of Exoplanets" (editors: H.
Deeg & J.A. Belmonte; Section Editor: N. Narita). 16 pages, 4 figure
Circumstellar disks and planets. Science cases for next-generation optical/infrared long-baseline interferometers
We present a review of the interplay between the evolution of circumstellar
disks and the formation of planets, both from the perspective of theoretical
models and dedicated observations. Based on this, we identify and discuss
fundamental questions concerning the formation and evolution of circumstellar
disks and planets which can be addressed in the near future with optical and
infrared long-baseline interferometers. Furthermore, the importance of
complementary observations with long-baseline (sub)millimeter interferometers
and high-sensitivity infrared observatories is outlined.Comment: 83 pages; Accepted for publication in "Astronomy and Astrophysics
Review"; The final publication is available at http://www.springerlink.co
Characterization and relative ionization efficiencies of end-functionalized polystyrenes by matrix-assisted laser desorption/ionization mass spectrometry
Single-cell analysis: visualizing pharmaceutical and metabolite uptake in cells with label-free 3D mass spectrometry imaging
Detecting metabolites and parent compound within a cell type is now a priority for pharmaceutical development. In this context, three-dimensional secondary ion mass spectrometry (SIMS) imaging was used to investigate the cellular uptake of the antiarrhythmic agent amiodarone, a phospholipidosis-inducing pharmaceutical compound. The high lateral resolution and 3D imaging capabilities of SIMS combined with the multiplex capabilities of ToF mass spectrometric detection allows for the visualization of pharmaceutical compound and metabolites in single cells. The intact, unlabeled drug compound was successfully detected at therapeutic dosages in macrophages (cell line: NR8383). Chemical information from endogenous biomolecules was used to correlate drug distributions with morphological features. From this spatial analysis, amiodarone was detected throughout the cell with the majority of the compound found in the membrane and subsurface regions and absent in the nuclear regions. Similar results were obtained when the macrophages were doped with amiodarone metabolite, desethylamiodarone. The FWHM lateral resolution measured across an intracellular interface in a high lateral resolution ion images was approximately 550 nm. Overall, this approach provides the basis for studying cellular uptake of pharmaceutical compounds and their metabolites on the single cell level
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