Incremental planning to control a blackboard-based problem solver

To control problem solving activity, a planner must resolve uncertainty about which specific long-term goals (solutions) to pursue and about which sequences of actions will best achieve those goals. A planner is described that abstracts the problem solving state to recognize possible competing and compatible solutions and to roughly predict the importance and expense of developing these solutions. With this information, the planner plans sequences of problem solving activities that most efficiently resolve its uncertainty about which of the possible solutions to work toward. The planner only details actions for the near future because the results of these actions will influence how (and whether) a plan should be pursued. As problem solving proceeds, the planner adds new details to the plan incrementally, and monitors and repairs the plan to insure it achieves its goals whenever possible. Through experiments, researchers illustrate how these new mechanisms significantly improve problem solving decisions and reduce overall computation. They briefly discuss current research directions, including how these mechanisms can improve a problem solver's real-time response and can enhance cooperation in a distributed problem solving network

Mapping the predicted and potential impacts of metal mining and its mitigation measures in Arctic and boreal regions using environmental and social impact assessments: a systematic map protocol

Abstract : Background: Since the 1960s, environmental impact assessments (EIAs) and recently, social impact assessments (SIAs), have been conducted during the planning stages of large development projects to identify potential adverse effects and propose mitigation measures to ameliorate these impacts. EIAs and SIAs should outline all possible posi- tive and negative effects of a proposed action or development on ecological and social systems, respectively, includ- ing biodiversity, flora and fauna, abiotic components (such as air quality), human health, security and wellbeing. The work outlined herein aims to generate a list of all possible direct and indirect effects of metal mining (including gold, iron, copper, nickel, zinc, silver, molybdenum and lead) along with the impacts of mitigation measures proposed, that are mentioned in EIAs and SIAs in Arctic and boreal regions of the following countries/regions: Canada, Alaska (USA), Greenland, the Faroe Islands, Iceland, Norway, Sweden, Finland and Russia. Methods: We will conduct searches for environmental and social impact assessments in Swedish and English, and until theoretical saturation is reached (i.e. no new action-impact pathways are identified). We will perform searches of specialist websites (e.g. public repositories of environmental and social impact assessments) and Google Scholar. We will also contact relevant stakeholders (that have been identified in the wider 3MK project https://osf.io/cvh3u/) and make a call for additional information. Eligibility screening will be conducted at two levels: title and full text. Meta-data will be extracted from eligible studies including type of mining activity, location of mine, type of impacts, and planned mitigation measures. Findings will be presented narratively, in a searchable relational database and in an evidence altas (a cartographic map). We will produce a framework of different mining impacts and related mitiga- tion measures from practitioners’ knowledge reflected in EIAs and SIAs. This framework will further form the basis of a multiple knowledge base on mining impacts and mitigation measures generated from different knowledges includ- ing scientific, Indigenous, and practitioners’ knowledge

Safety Profile of Upadacitinib up to 3 Years in Psoriatic Arthritis: An Integrated Analysis of Two Pivotal Phase 3 Trials

Introduction: This integrated analysis describes the safety profile of upadacitinib, an oral Janus kinase inhibitor, at 15 and 30 mg once daily for up to 3 years of exposure in patients with active psoriatic arthritis (PsA) who had a prior inadequate response or intolerance to ≥ 1 non-biologic or biologic disease-modifying antirheumatic drug. Methods: Safety data were pooled and analyzed from two randomized, placebo-controlled phase 3 trials. Both trials evaluated upadacitinib 15 mg and 30 mg once daily, and one trial also evaluated adalimumab 40 mg every other week. Treatment-emergent adverse events (TEAEs) and laboratory data were summarized for four groups: pooled placebo, pooled upadacitinib 15 mg, pooled upadacitinib 30 mg, and adalimumab. TEAEs were reported as exposure-adjusted event rates (events per 100 patient-years [E/100 PY]) up to a data cut-off of June 29, 2020. Results: A total of 2257 patients received ≥ 1 dose of upadacitinib 15 mg (N = 907) or 30 mg (N = 921) for 2504.6 PY of exposure or adalimumab (N = 429) for 549.7 PY of exposure. Upper respiratory tract infection, nasopharyngitis, and increased creatine phosphokinase (CPK) were the most common TEAEs with upadacitinib. Rates of malignancies, adjudicated major adverse cardiovascular events (MACEs) and venous thromboembolic events (VTEs), and deaths were similar across treatment groups. Rates of herpes zoster (HZ) and opportunistic infections (OI; excluding tuberculosis, HZ, and oral candidiasis) were higher with upadacitinib versus adalimumab. Serious infection, anemia, and CPK elevations were most frequent with upadacitinib 30 mg. Potentially clinically significant laboratory abnormalities were uncommon. Conclusions: Upadacitinib 15 mg and adalimumab had similar safety profiles with the exception of HZ and OIs, consistent with what was observed in rheumatoid arthritis. Rates of malignancies, MACEs, VTEs, and deaths were comparable among patients receiving upadacitinib and adalimumab. No new safety risks emerged with longer-term exposure to upadacitinib. Trial Registration Numbers: SELECT-PsA 1: NCT03104400; SELECT-PsA 2: NCT03104374

Discovery of Globular Clusters in the Proto-Spiral NGC2915: Implications for Hierarchical Galaxy Evolution

We have discovered three globular clusters beyond the Holmberg radius in Hubble Space Telescope Advanced Camera for Surveys images of the gas-rich dark matter dominated blue compact dwarf galaxy NGC2915. The clusters, all of which start to resolve into stars, have M_{V606} = -8.9 to -9.8 mag, significantly brighter than the peak of the luminosity function of Milky Way globular clusters. Their colors suggest a metallicity [Fe/H] ~ -1.9 dex, typical of metal-poor Galactic globular clusters. The specific frequency of clusters is at a minimum normal, compared to spiral galaxies. However, since only a small portion of the system has been surveyed it is more likely that the luminosity and mass normalized cluster content is higher, like that seen in elliptical galaxies and galaxy clusters. This suggests that NGC2915 resembles a key phase in the early hierarchical assembly of galaxies - the epoch when much of the old stellar population has formed, but little of the stellar disk. Depending on the subsequent interaction history, such systems could go on to build-up larger elliptical galaxies, evolve into normal spirals, or in rare circumstances remain suspended in their development to become systems like NGC2915.Comment: ApJ Letters accepted; 6 pages, 2 figures, 3 table

Advanced Camera for Surveys Observations of Young Star Clusters in the Interacting Galaxy UGC 10214

We present the first Advanced Camera for Surveys (ACS) observations of young star clusters in the colliding/merging galaxy UGC 10214. The observations were made as part of the Early Release Observation (ERO) program for the newly installed ACS during service mission SM3B for the Hubble Space Telescope (HST). Many young star clusters can be identified in the tails of UGC 10214, with ages ranging from ~3 Myr to 10 Myr. The extreme blue V-I (F606W-F814W) colors of the star clusters found in the tail of UGC 10214 can only be explained if strong emission lines are included with a young stellar population. This has been confirmed by our Keck spectroscopy of some of these bright blue stellar knots. The most luminous and largest of these blue knots has an absolute magnitude of M_V = -14.45, with a half-light radius of 161 pc, and if it is a single star cluster, would qualify as a super star cluster (SSC). Alternatively, it could be a superposition of multiple scaled OB associations or clusters. With an estimated age of ~ 4-5 Myr, its derived mass is < 1.3 x 10^6 solar masses. Thus the young stellar knot is unbound and will not evolve into a normal globular cluster. The bright blue clusters and associations are much younger than the dynamical age of the tail, providing strong evidence that star formation occurs in the tail long after it was ejected. UGC 10214 provides a nearby example of processes that contributed to the formation of halos and intra-cluster media in the distant and younger Universe.Comment: 6 pages with embedded figures, ApJ in pres

Internal Color Properties of Resolved Spheroids in the Deep HST/ACS field of UGC 10214

(Abridged) We study the internal color properties of a morphologically selected sample of spheroidal galaxies taken from HST/ACS ERO program of UGC 10214 (``The Tadpole''). By taking advantage of the unprecedented high resolution of the ACS in this very deep dataset we are able to characterize spheroids at sub-arcseconds scales. Using the V_606W and I_814W bands, we construct V-I color maps and extract color gradients for a sample of spheroids at I_814W < 24 mag. We investigate the existence of a population of morphologically classified spheroids which show extreme variation in their internal color properties similar to the ones reported in the HDFs. These are displayed as blue cores and inverse color gradients with respect to those accounted from metallicity variations. Following the same analysis we find a similar fraction of early-type systems (~30%-40%) that show non-homologous internal colors, suggestive of recent star formation activity. We present two statistics to quantify the internal color variation in galaxies and for tracing blue cores, from which we estimate the fraction of non-homogeneous to homogeneous internal colors as a function of redshift up to z<1.2. We find that it can be described as about constant as a function of redshift, with a small increase with redshift for the fraction of spheroids that present strong color dispersions. The implications of a constant fraction at all redshifts suggests the existence of a relatively permanent population of evolving spheroids up to z~1. We discuss the implications of this in the context of spheroidal formation.Comment: Fixed URL for high resolution version. 13 Pages, 10 Figures. Accepted for Publication in ApJ. Sep 1st issue. Higher resolution version and complete table3B at http://acs.pha.jhu.edu/~felipe/e-prints/Tadpol

The Luminosity Function of Early-Type Galaxies at z~0.75

We measure the luminosity function of morphologically selected E/S0 galaxies from $z=0.5$ to $z=1.0$ using deep high resolution Advanced Camera for Surveys imaging data. Our analysis covers an area of 48\Box\arcmin (8$\times$ the area of the HDF-N) and extends 2 magnitudes deeper ($I\sim24$ mag) than was possible in the Deep Groth Strip Survey (DGSS). At $0.5<z<0.75$, we find $M_B^*-5\log h_{0.7}=-21.1\pm0.3$ and $\alpha=-0.53\pm0.2$, and at $0.75<z<1.0$, we find $M_B^*-5\log h_{0.7}=-21.4\pm0.2$. These luminosity functions are similar in both shape and number density to the luminosity function using morphological selection (e.g., DGSS), but are much steeper than the luminosity functions of samples selected using morphological proxies like the color or spectral energy distribution (e.g., CFRS, CADIS, or COMBO-17). The difference is due to the `blue', $(U-V)_0<1.7$, E/S0 galaxies, which make up to $\sim30$ of the sample at all magnitudes and an increasing proportion of faint galaxies. We thereby demonstrate the need for {\it both morphological and structural information} to constrain the evolution of galaxies. We find that the `blue' E/S0 galaxies have the same average sizes and Sersic parameters as the `red', $(U-V)_0>1.7$, E/S0 galaxies at brighter luminosities ($M_B<-20.1$), but are increasingly different at fainter magnitudes where `blue' galaxies are both smaller and have lower Sersic parameters. Fits of the colors to stellar population models suggest that most E/S0 galaxies have short star-formation time scales ($\tau<1$ Gyr), and that galaxies have formed at an increasing rate from $z\sim8$ until $z\sim2$ after which there has been a gradual decline.Comment: 39 pages, 21 figures, accepted in A