20,340 research outputs found
The far right, the mainstream and mainstreaming: towards a heuristic framework
The study of far-right parties and politics is one of the most high-profile research areas in political science and related disciplines. Far-right parties have been the subject of vast amounts of varied scholarship since their turn-of-the-century resurgence. However, as the far right has become a mainstay, with Brexit and the election of Donald Trump in 2016 blurring the boundaries between mainstream and far-right politics, it has become crucial to pay attention to the process of mainstreaming. Beyond a focus on far-right electoral success, studies of mainstreaming, as well as a critical account of the concept and role of the ‘mainstream’, have proved elusive. This article provides a heuristic framework to understand these concepts and the mainstreaming of the far right. Key to our approach is a more holistic analysis, extending beyond traditional approaches which focus mostly on the electoral outcomes of far-right parties, positioning the mainstream as a relatively inert target or bulwark against them. To achieve this, we seek to reframe the focus towards the centrality of discourse both in the process, and as an outcome, of mainstreaming. Only by doing so can we account for the significant role played by the mainstream in this process
A Compound model for the origin of Earth's water
One of the most important subjects of debate in the formation of the solar
system is the origin of Earth's water. Comets have long been considered as the
most likely source of the delivery of water to Earth. However, elemental and
isotopic arguments suggest a very small contribution from these objects. Other
sources have also been proposed, among which, local adsorption of water vapor
onto dust grains in the primordial nebula and delivery through planetesimals
and planetary embryos have become more prominent. However, no sole source of
water provides a satisfactory explanation for Earth's water as a whole. In view
of that, using numerical simulations, we have developed a compound model
incorporating both the principal endogenous and exogenous theories, and
investigating their implications for terrestrial planet formation and
water-delivery. Comets are also considered in the final analysis, as it is
likely that at least some of Earth's water has cometary origin. We analyze our
results comparing two different water distribution models, and complement our
study using D/H ratio, finding possible relative contributions from each
source, focusing on planets formed in the habitable zone. We find that the
compound model play an important role by showing more advantage in the amount
and time of water-delivery in Earth-like planets.Comment: Accepted for publication in The Astrophysical Journa
Remarks on additivity of the Holevo channel capacity and of the entanglement of formation
The purpose of these notes is to discuss the relation between the additivity questions regarding the quantities (Holevo) capacity of a quantum channel T and entanglement of formation of a given bipartite state. In particular, using the Stinespring dilation theorem, we give a formula for the channel capacity involving entanglement of formation. This can be used to show that additivity of the latter for some states can be inferred from the additivity of capacity for certain channels. We demonstrate this connection for a family of group--covariant channels, allowing us to calculate the entanglement cost for many states, including some where a strictly smaller upper bound on the distillable entanglement is known. This is presented in a general framework, extending recent findings of Vidal, Dur and Cirac (e-print quant-ph/0112131). In an appendix we speculate on a general relation of superadditivity of the entanglement of formation, which would imply both the general additivity of this function under tensor products and of the Holevo capacity (with or without linear cost constraints)
Half-Life of O
We have measured the half-life of O, a superallowed decay isotope. The O was produced by the
C(He,n)O reaction using a carbon aerogel target. A
low-energy ion beam of O was mass separated and implanted in a thin
beryllium foil. The beta particles were counted with plastic scintillator
detectors. We find s. This result is
higher than an average value from six earlier experiments, but agrees more
closely with the most recent previous measurement.Comment: 10 pages, 5 figure
On the fidelity of two pure states
The fidelity of two pure states (also known as transition probability) is a
symmetric function of two operators, and well-founded operationally as an event
probability in a certain preparation-test pair. Motivated by the idea that the
fidelity is the continuous quantum extension of the combinatorial equality
function, we enquire whether there exists a symmetric operational way of
obtaining the fidelity. It is shown that this is impossible. Finally, we
discuss the optimal universal approximation by a quantum operation.Comment: LaTeX2e, 8 pages, submitted to J. Phys. A: Math. and Ge
Operational interpretations of quantum discord
Quantum discord quantifies non-classical correlations going beyond the
standard classification of quantum states into entangled and unentangled ones.
Although it has received considerable attention, it still lacks any precise
interpretation in terms of some protocol in which quantum features are
relevant. Here we give quantum discord its first operational meaning in terms
of entanglement consumption in an extended quantum state merging protocol. We
further relate the asymmetry of quantum discord with the performance imbalance
in quantum state merging and dense coding.Comment: v4: 5 pages, 1 fig. Refs added, text improved. Main results
unchanged. See arXiv:1008.4135v2 for a related work. v5: close to the
published versio
Fat transforms ascorbic acid from inhibiting to promoting acid-catalysed N-nitrosation
<b>Background</b>: The major potential site of acid nitrosation is the proximal stomach, an anatomical site prone to
a rising incidence of metaplasia and adenocarcinoma. Nitrite, a pre-carcinogen present in saliva, can be
converted to nitrosating species and N-nitroso compounds by acidification at low gastric pH in the presence
of thiocyanate.
<b>Aims</b>: To assess the effect of lipid and ascorbic acid on the nitrosative chemistry under conditions simulating
the human proximal stomach.
<b>Methods</b>: The nitrosative chemistry was modelled in vitro by measuring the nitrosation of four secondary
amines under conditions simulating the proximal stomach. The N-nitrosamines formed were measured by gas
chromatography–ion-trap tandem mass spectrometry, while nitric oxide and oxygen levels were measured
amperometrically.
<b>Results</b>: In absence of lipid, nitrosative stress was inhibited by ascorbic acid through conversion of nitrosating
species to nitric oxide. Addition of ascorbic acid reduced the amount of N-nitrosodimethylamine formed by
fivefold, N-nitrosomorpholine by .1000-fold, and totally prevented the formation of N-nitrosodiethylamine
and N-nitrosopiperidine. In contrast, when 10% lipid was present, ascorbic acid increased the amount of Nnitrosodimethylamine,
N-nitrosodiethylamine and N-nitrosopiperidine formed by approximately 8-, 60- and
140-fold, respectively, compared with absence of ascorbic acid.
<b>Conclusion</b>: The presence of lipid converts ascorbic acid from inhibiting to promoting acid nitrosation. This
may be explained by nitric oxide, formed by ascorbic acid in the aqueous phase, being able to regenerate
nitrosating species by reacting with oxygen in the lipid phase
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