Goal-Space Planning with Subgoal Models

This paper investigates a new approach to model-based reinforcement learning using background planning: mixing (approximate) dynamic programming updates and model-free updates, similar to the Dyna architecture. Background planning with learned models is often worse than model-free alternatives, such as Double DQN, even though the former uses significantly more memory and computation. The fundamental problem is that learned models can be inaccurate and often generate invalid states, especially when iterated many steps. In this paper, we avoid this limitation by constraining background planning to a set of (abstract) subgoals and learning only local, subgoal-conditioned models. This goal-space planning (GSP) approach is more computationally efficient, naturally incorporates temporal abstraction for faster long-horizon planning and avoids learning the transition dynamics entirely. We show that our GSP algorithm can learn significantly faster than a Double DQN baseline in a variety of situations

Change in pain and its relation to change in activity in osteoarthritis

Objective Trials testing promising interventions in knee osteoarthritis (OA) often fail to show pain reductions. This may be due to change in activity whereby a person’s pain decreases, leading them to increase their activity levels, in turn increasing pain back to baseline levels. Using data from a trial of a beneficial treatment for knee pain, we explored whether activity changes might mask a treatment’s effect on pain, by looking at whether activity levels increased with effective treatment and whether change in activity level related to change in pain. Design During the InRespond trial (ISRCTN55059760) participants wore an accelerometer for 7 days before and during treatments. We assessed change in pain on treatment using scores for overall knee pain and pain in a nominated pain-aggravating activity both in the last week and evaluated change in different types of activity using accelerometer data. Principal components analysis tested whether change in activity and pain outcomes were correlated and created composites combining them. We then tested whether activity, pain or the composites showed a treatment effect, and examined their responsiveness. Results In the 61 participants (mean age 64.5 years, 38% women, mean overall knee pain score 5.08 (0-10)), activity levels mostly decreased during the trial. Principal component analyses suggested that pain and activity did not correlate highly, loading on different components. Treatment that showed significant effects on pain did not show similar effects on either activity (e.g. the active treatment had a slightly greater reduction in total steps taken than the control treatment (difference 1942.6 steps/week, p =.42) nor on composites combining activity and pain. Pain outcomes were the most responsive; static loading (standing) outcomes were the most responsive activity outcome. Conclusion We found no evidence to support the hypothesis that activity levels increase during effective OA treatment and might account for the negligible pain effects of OA treatments

The Limits of Anthropocene Narratives

The rapidly growing transdisciplinary enthusiasm about developing new kinds of Anthropocene stories is based on the shared assumption that the Anthropocene predicament is best made sense of by narrative means. Against this assumption, this article argues that the challenge we are facing today does not merely lie in telling either scientific, socio-political, or entangled Anthropocene narratives to come to terms with our current condition. Instead, the challenge lies in coming to grips with how the stories we can tell in the Anthropocene relate to the radical novelty of the Anthropocene condition about which no stories can be told. What we need to find are meaningful ways to reconcile an inherited commitment to narrativization and the collapse of storytelling as a vehicle of understanding the Anthropocene as our current predicament

Attachment-related mentalization moderates the relationship between psychopathic traits and proactive aggression in adolescence

The lack of affective responsiveness to others' mental states - one of the hallmarks of psychopathy - is thought to give rise to increased interpersonal aggression. Recent models of psychopathy highlight deficits in attachment security that may, in turn, impede the development of relating to others in terms of mental states (mentalization). Here, we aimed to assess whether mentalization linked to attachment relationships may serve as a moderator for the relationship between interpersonal aggression and psychopathic traits in an adolescent community sample. Data from 104 males and females with a mean age of 16.4 years were collected on mentalization capacities using the Reflective Functioning Scale on the Adult Attachment Interview (AAI). Psychopathic traits and aggressive behavior were measured via self-report. Deficits in mentalization were significantly associated with both psychopathic traits and proactive aggression. As predicted, mentalization played a moderating role, such that individuals with increased psychopathic tendencies did not display increased proactive aggression when they had higher mentalizing capacities. Effects of mentalization on reactive aggression were fully accounted for by its shared variance with proactive aggression. Psychopathic traits alone only partially explain aggression in adolescence. Mentalization may serve as a protective factor to prevent the emergence of proactive aggression in spite of psychopathic traits and may provide a crucial target for intervention

Arp 302: Non-starburst Luminous Infrared Galaxies

Arp 302, a luminous infrared source (L_{IR} = 4.2x10^{11} Lsun), consisting of two spiral galaxies (VV340A and VV340B) with nuclear separation of 40'', has the highest CO luminosity known. Observations with the BIMA array at 5'' X 7'' resolution reveal that the CO emission is extended over 23.0 kpc in the edge-on spiral galaxy, VV340A, corresponding to 6.7x10^{10} Msun of H_2. In the companion face-on galaxy, VV340B, the CO emission is extended over ~10.0 kpc, with 1.1x10^{10} Msun of H_2. The large CO extent is in strong contrast to starburst systems, such as Arp 220, in which the CO extent is typically $\le$ 1 kpc. Furthermore, $L_{IR}/M$(H_2) is found to be $\le$ 6.0 Lsun/Msun throughout both galaxies. Thus the high IR luminosity of Arp 302 is apparently not due to starbursts in the nuclear regions, but is due to its unusually large amount of molecular gas forming stars at a rate similar to giant molecular clouds in the Milky Way disk. Arp 302 consists of a pair of very gas-rich spiral galaxies that may be interacting and in a phase before a likely onset of starbursts.Comment: AAS Latex plus two postscript figures. ApJ Letters (accepted

Sub-arcsecond CO(1-0) and CO(2-1) observations of the ultraluminous infrared galaxy IRAS 10190+1322

We present the results of high resolution mapping of the CO(1-0) and CO(2-1) emission of the ultraluminous infrared galaxy (ULIRG) IRAS 10190+1322, with the IRAM interferometer, down to an angular resolution of ~0.3 arcsec. This object is composed of two interacting galaxies with a projected nuclear separation of 6 kpc, and was selected to analyze the physical and dynamical properties of the molecular gas in each galaxy in order to study the conditions that lead a galaxy pair to become ultraluminous in the infrared. With the exception of Arp 220, the closest ULIRG, this is the first time that the CO emission is morphologically and kinematically resolved in the two interacting galaxies of a ULIRG system. In one of the galaxies the molecular gas is highly concentrated, distributed in a circumnuclear disk of 1.7 kpc in size. The molecular gas in the presumably less infrared luminous galaxy is distributed in a more extended disk of 7.4 kpc. The molecular gas mass accounts for ~10% of the dynamical mass in each galaxy. Both objects are rich enough in molecular gas, Mgas ~ 4 10^9 Msun, as to experience an infrared ultraluminous phase.Comment: 4 pages, 3 figures. Accepted for publication in A&A Letters Special Issue for the new extended configuration of the Plateau de Bure Interferomete

The phosphotyrosine-independent interaction of DLC-1 and the SH2 domain of cten regulates focal adhesion localization and growth suppression activity of DLC-1

The tensin family member cten (C-terminal tensin like) is an Src homology 2 (SH2) and phosphotyrosine binding domain–containing focal adhesion molecule that may function as a tumor suppressor. However, the mechanism has not been well established. We report that cten binds to another tumor suppressor, deleted in liver cancer 1 (DLC-1), and the SH2 domain of cten is responsible for the interaction. Unexpectedly, the interaction between DLC-1 and the cten SH2 domain is independent of tyrosine phosphorylation of DLC-1. By site-directed mutagenesis, we have identified several amino acid residues on cten and DLC-1 that are essential for this interaction. Mutations on DLC-1 perturb the interaction with cten and disrupt the focal adhesion localization of DLC-1. Furthermore, these DLC-1 mutants have lost their tumor suppression activities. When these DLC-1 mutants were fused to a focal adhesion targeting sequence, their tumor suppression activities were significantly restored. These results provide a novel mechanism whereby the SH2 domain of cten-mediated focal adhesion localization of DLC-1 plays an essential role in its tumor suppression activity

Strangers in the night: Discovery of a dwarf spheroidal galaxy on its first Local Group infall

We present spectroscopic observations of the AndXII dwarf spheroidal galaxy using DEIMOS/Keck-II, showing it to be moving rapidly through the Local Group (-556 km/s heliocentric velocity, -281 km/s relative to Andromeda from the MW), falling into the Local Group from ~115 kpc beyond Andromeda's nucleus. AndXII therefore represents a dwarf galaxy plausibly falling into the Local Group for the first time, and never having experienced a dense galactic environment. From Green Bank Telescope observations, a limit on the H{I} gas mass of <3000 Msun suggests that AndXII's gas could have been removed prior to experiencing the tides of the Local Group galaxies. Orbit models suggest the dwarf is close to the escape velocity of M31 for published mass models. AndXII is our best direct evidence for the late infall of satellite galaxies, a prediction of cosmological simulations.Comment: 4 pages 5 figures 1 table, accepted in ApJ, july issu

Analysis of H2O Masers in Sharpless 269 using VERA Archival data --- Effect of maser structures on astrometric accuracy

Astrometry using H2O maser sources in star forming regions is expected to be a powerful tool to study the structures and dynamics of our Galaxy. Honma et al. (2007) (hereafter H2007) claimed that the annual parallax of S269 is determined within an error of 0.008 milliarcsec (mas), concluding that S269 is located at 5.3 kpc +- 0.2 kpc from the sun, and R= 13.1 kpc. They claimed that the rotational velocity of S269 is equal to that of the sun within a 3% error. This small error, however, is hardly understood when taking into account the results of other observations and theoretical studies of galactic dynamics. We here reanalyzed the VERA archival data using the self-calibration method (hybrid mapping), and found that clusters of maser features of S269 are distributed in much wider area than that investigated in H2007. We confirmed that, if we make a narrow region image without considering the presence of multiple maser spots, and only the phase calibration is applied, we can reproduce the same maser structures in H2007. The distribution extent of maser spots in the feature differs 0.2 mas from east to west between our results and H2007. Moreover, we found that change of relative positions of maser spots in the cluster reaches 0.1 mas or larger between observational epochs. This suggests that if one simply assumes the time-dependent, widely distributed maser sources as a stable single point source, it could cause errors of up to 0.1 mas in the annual parallax of S269. Taking into account the internal motions of maser spot clusters, the proper motion of S269 cannot be determined precisely. We estimated that the peculiar motion of S269 with respect to a Galactic circular rotation is ~20 km/s. These results imply that the observed kinematics of maser emissions in S269 cannot give a strong constraint on dynamics of the outer part of the Galaxy, in contrast to the claim by H2007.Comment: 33 pages, 11 figures, to be published in New Astronom