The Sub-Additives: A Proof Theory for Probabilistic Choice extending Linear Logic

Probabilistic choice, where each branch of a choice is weighted according to a probability distribution, is an established approach for modelling processes, quantifying uncertainty in the environment and other sources of randomness. This paper uncovers new insight showing probabilistic choice has a purely logical interpretation as an operator in an extension of linear logic. By forbidding projection and injection, we reveal additive operators between the standard with and plus operators of linear logic. We call these operators the sub-additives. The attention of the reader is drawn to two sub-additive operators: the first being sound with respect to probabilistic choice; while the second arises due to the fact that probabilistic choice cannot be self-dual, hence has a de Morgan dual counterpart. The proof theoretic justification for the sub-additives is a cut elimination result, employing a technique called decomposition. The justification from the perspective of modelling probabilistic concurrent processes is that implication is sound with respect to established notions of probabilistic refinement, and is fully compositional

BRD4 associates with p53 in DNMT3A-mutated leukemia cells and is implicated in apoptosis by the bromodomain inhibitor JQ1

The bromodomain and extra terminal (BET) family protein bromodomain containing protein 4 (BRD4) is an epigenetic regulator recently identified as a therapeutic target for several hematological cancers, notably mixed lineage leukemia-fusion acute myeloid leukemia (MLL-AML). Here, we show that the BRD4 bromodomain inhibitor JQ1 is highly active against the p53-wild-type Ontario Cancer Institute (OCI)-AML3 cell line which carries mutations in nucleophosmin (NPM1) and DNA methyltransferase 3 (DNMT3A) genes commonly associated with poor prognostic disease. We find that JQ1 causes caspase 3/7-mediated apoptosis and DNA damage response in these cells. In combination studies, we show that histone deacetylase (HDAC) inhibitors, the HDM2 inhibitor Nutlin-3, and the anthracycline daunorubicin all enhance the apoptotic response of JQ1. These compounds all induce activation of p53 suggesting that JQ1 might sensitize AML cells to p53-mediated cell death. In further experiments, we show that BRD4 associates with acetylated p53 but that this association is not inhibited by JQ1 indicating that the protein-protein interaction does not involve bromodomain binding of acetylated lysines. Instead, we propose that JQ1 acts to prevent BRD4-mediated recruitment of p53 to chromatin targets following its activation in OCI-AML3 cells resulting in cell cycle arrest and apoptosis in a c-MYC-independent manner. Our data suggest that BET bromodomain inhibition might enhance current chemotherapy strategies in AML, notably in poor-risk DNMT3A/NPM1-mutated disease

Correlated X-ray/Ultraviolet/Optical Variability in NGC 6814

We present results of a 3-month combined X-ray/UV/optical monitoring campaign of the Seyfert 1 galaxy NGC 6814. The object was monitored by Swift from June through August 2012 in the X-ray and UV bands and by the Liverpool Telescope from May through July 2012 in B and V. The light curves are variable and significantly correlated between wavebands. Using cross-correlation analysis, we compute the time lag between the X-ray and lower energy bands. These lags are thought to be associated with the light travel time between the central X-ray emitting region and areas further out on the accretion disc. The computed lags support a thermal reprocessing scenario in which X-ray photons heat the disc and are reprocessed into lower energy photons. Additionally, we fit the lightcurves using CREAM, a Markov Chain Monte Carlo code for a standard disc. The best-fitting standard disc model yields unreasonably high super-Eddington accretion rates. Assuming more reasonable accretion rates would result in significantly under-predicted lags. If the majority of the reprocessing originates in the disc, then this implies the UV/optical emitting regions of the accretion disc are farther out than predicted by the standard thin disc model. Accounting for contributions from broad emission lines reduces the lags in B and V by approximately 25% (less than the uncertainty in the lag measurements), though additional contamination from the Balmer continuum may also contribute to the larger than expected lags. This discrepancy between the predicted and measured interband delays is now becoming common in AGN where wavelength-dependent lags are measured.Comment: 11 pages, 8 figures, accepted for publication in MNRA

Charged Dilaton Black Holes with Unusual Asymptotics

We present a new class of black hole solutions in Einstein-Maxwell-dilaton gravity in $n \ge 4$ dimensions. These solutions have regular horizons and a singularity only at the origin. Their asymptotic behavior is neither asymptotically flat nor (anti-) de Sitter. Similar solutions exist for certain Liouville-type potentials for the dilaton.Comment: 24 pages, harvmac.tex, no figure

Who Dislikes Whom? Affective Polarization between Pairs of Parties in Western Democracies

While dislike of opposing parties, that is, affective polarization, is a defining feature of contemporary politics, research on this topic largely centers on the United States. We introduce an approach that analyzes affective polarization between pairs of parties, bridging the US two-party system and multiparty systems in other democracies. Analyzing survey data from twenty Western democracies since the mid-1990s, first, we show that partisans' dislike of out-parties is linked to elite policy disagreements on economic issues and, increasingly over time, also to cultural issues. Secondly, we argue and empirically demonstrate that governing coalition partners in parliamentary democracies display much warmer feelings toward each other than we would expect based on elite policy (dis)agreements. Third, we show that radical right parties are disliked much more intensely than we would expect based on policy disputes and coalition arrangements. These findings highlight the policy-based and institutional underpinnings of affective polarization

A search for starlight reflected from HD 75289 b

We have used a doppler tomographic analysis to conduct a deep search for the starlight reflected from the planetary companion to HD 75289. In 4 nights on VLT2/UVES in January 2003, we obtained 684 high resolution echelle spectra with a total integration time of 26 hours. We establish an upper limit on the planet's geometric albedo p < 0.12 (to the 99.9% significance level) at the most probable orbital inclination i ~ 60 degrees, assuming a grey albedo, a Venus-like phase function and a planetary radius R_p = 1.6 R_Jup. We are able to rule out some combinations of the predicted planetary radius and atmospheric albedo models with high, reflective cloud decks.Comment: 5 pages, 5 figures, MNRAS accepted 12 Oct 200

Sleep restriction and serving accuracy in performance tennis players, and effects of caffeine

Athletes often lose sleep on the night before a competition. Whilst it is unlikely that sleep loss will impair sports mostly relying on strength and endurance, little is known about potential effects on sports involving psychomotor performance requiring high level cognitive skills necessitating judgement and accuracy, as in tennis, and where caffeine is ‘permitted’’. Two studies were undertaken on the effects of 5h sleep (33%) restriction versus normal sleep, on an objective measure of serving accuracy in semi-professional tennis players. Testing (14:00h-16:00h) for both studies comprised 40 serves into a (1.8m x 1.1m) ‘service box’ diagonally, over the net. Study 2 was identical to that of Study 1, except that there was an extra sleep restriction condition. All conditions involved a sugar free drink given 30 min before testing, but with the drink for one sleep restriction containing 80mg caffeine (double blind). Study 1 comprised 16 men and women, in a within Ss counterbalanced design (normal versus sleep restriction). Study 2 involved 12 different men and women undergoing three conditions in a latin square design. Conditions were as for Study 1, with a replicated sleep restriction. All conditions incorporated a sugar-free drink given 30 min before testing, with one restriction including 80mg caffeine (double blind). Both studies showed significant impairments to serving accuracy following sleep restriction, particularly with women. At this dose, caffeine had no beneficial effect. These results reflect laboratory based, non-sports related findings pointing to detrimental effects of sleep loss on executive function

S-Duality at the Black Hole Threshold in Gravitational Collapse

We study gravitational collapse of the axion/dilaton field in classical low energy string theory, at the threshold for black hole formation. A new critical solution is derived that is spherically symmetric and continuously self-similar. The universal scaling and echoing behavior discovered by Choptuik in gravitational collapse appear in a somewhat different form. In particular, echoing takes the form of SL(2,R) rotations (cf. S-duality). The collapse leaves behind an outgoing pulse of axion/dilaton radiation, with nearly but not exactly flat spacetime within it.Comment: 8 pages of LaTeX, uses style "revtex"; 1 figure, available in archive, or at ftp://ftp.itp.ucsb.edu/figures/nsf-itp-95-15.ep