System Resource Sharing for Synchronous Collaboration

We describe problems associated with accessing data resources external to the application, which we term externalities, in replicated synchronous collaborative applications (e.g., a multiuser text editor). Accessing externalities such as les, databases, network connections, environment variables and the system clock is not as straightforward in replicated collaborative software as in single-user applications and centralized collaborative systems. We describe ad hoc solutions that have been used previously. Our primary objection to the ad hoc solutions is that the developer must program dierent behavior into the dierent replicas of a multi-user application, which increases the cost and complexity of development. We introduce a novel general approach to accessing externalities uniformly in a replicated collaborative system. The approach uses a semi-replicated architecture where the actual externality resides at a single location and is accessed via replicated proxies. The proxies multiplex input to and output from the single instance of the externality. This approach facilitates the creation of replicated synchronous groupware in two ways: (1) developers use the same mechanisms as in traditional single-user applications (2) developers program all replicas to execute the same behavior. We describe a general design for proxied access to read{only, write{only and read{write externalities. We discuss the tradeos of this semi- replicated approach over full, literal replication and the class of applications to which this approach can be successfully applied. We also describe details of a prototype implementation of this approach within a replicated collaboration-transparency system, called Flexible JAMM (Java Applets Made Multi-user)

Molecular Targets of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) within the Zebrafish Ovary: Insights into TCDD-induced Endocrine Disruption and Reproductive Toxicity

TCDD is a reproductive toxicant and endocrine disruptor, yet the mechanisms by which it causes these reproductive alterations are not fully understood. In order to provide additional insight into the molecular mechanisms that underlie TCDD\u27s reproductive toxicity, we assessed TCDD-induced transcriptional changes in the ovary as they relate to previously described impacts on serum estradiol concentrations and altered follicular development in zebrafish. In silico computational approaches were used to correlate candidate regulatory motifs with observed changes in gene expression. Our data suggest that TCDD inhibits follicle maturation via attenuated gonadotropin responsiveness and/or depressed estradiol biosynthesis, and that interference of estrogen-regulated signal transduction may also contribute to TCDD\u27s impacts on follicular development. TCDD may also alter ovarian function by disrupting various signaling pathways such as glucose and lipid metabolism, and regulation of transcription. Furthermore, events downstream from initial TCDD molecular-targets likely contribute to ovarian toxicity following chronic exposure to TCDD. Data presented here provide further insight into the mechanisms by which TCDD disrupts follicular development and reproduction in fish, and can be used to formulate new hypotheses regarding previously documented ovarian toxicity

Insoluble Residue Studies of the Columbus and Delaware Limestones in Ohio

Author Institution: Department of Geology, The Ohio State University, Columbus 10 ; Columbus, Ohio ; Standard Oil Company of Texas, Houston Texas and Lion Oil Company, Denver Colorad

Status report to DOE Nuclear Data Committee

This status report from Lawrence Livermore Laboratory covers work in the areas of nuclear data applications - measurements, nuclear data application - calculations, nuclear data for reactor safety, fission physics, and data evaluation and compilation. Separate abstracts were prepared for seven of the contributions to this report. 7 figures, 3 tables. (RWR

Large-scale Motions in the Perseus Galaxy Cluster

By combining large-scale mosaics of ROSAT PSPC, XMM-Newton, and Suzaku X-ray observations, we present evidence for large-scale motions in the intracluster medium of the nearby, X-ray bright Perseus Cluster. These motions are suggested by several alternating and interleaved X-ray bright, low-temperature, low-entropy arcs located along the east-west axis, at radii ranging from ~10 kpc to over a Mpc. Thermodynamic features qualitatively similar to these have previously been observed in the centers of cool core clusters, and were successfully modeled as a consequence of the gas sloshing/swirling motions induced by minor mergers. Our observations indicate that such sloshing/swirling can extend out to larger radii than previously thought, on scales approaching the virial radius.Comment: 6 pages, 6 figures, accepted for publication in Ap

Direct optimization across computer generated reaction networks balances materials use and feasibility of synthesis plans for molecule libraries

The synthesis of thousands of candidate compounds in drug discovery and development offers opportunities for computer-aided synthesis planning to simplify the synthesis of molecule libraries by leveraging common starting materials and reaction conditions. We develop an optimization-based method to analyze large organic chemical reaction networks and design overlapping synthesis plans for entire molecule libraries so as to minimize the overall number of unique chemical compounds needed as either starting materials or reaction conditions. We consider multiple objectives, including the number of starting materials, the number of catalysts/solvents/reagents, and the likelihood of success of the overall syntheses plan, to select an optimal reaction network to access the target molecules. The library synthesis planning task was formulated as a network flow optimization problem, and we design an efficient decomposition scheme that reduces solution time by a factor of 5 and scales to instance with 48 target molecules and nearly 8000 intermediate reactions within hours. In four case studies of pharmaceutical compounds, the approach reduces the number of starting materials and catalysts/solvents/reagents needed by 32.2 and 66.0% on average and up to 63.2 and 80.0% in the best cases. The code implementation can be found at [https://github.com/Coughy1991/Molecule_library_synthesis](https://github.com/Coughy1991/Molecule_library_synthesis) Supporting information: [https://pubs.acs.org/doi/10.1021/acs.jcim.0c01032?goto=supporting-info](https://pubs.acs.org/doi/10.1021/acs.jcim.0c01032?goto=supporting-info

Fast and slow rotators in the densest environments: a FLAMES/GIRAFFE IFS study of galaxies in Abell 1689 at z=0.183

We present FLAMES/GIRAFFE integral field spectroscopy of 30 galaxies in the massive cluster Abell 1689 at z = 0.183. Conducting an analysis similar to that of ATLAS3D, we extend the baseline of the kinematic morphology-density relation by an order of magnitude in projected density and show that it is possible to use existing instruments to identify slow and fast rotators beyond the local Universe. We find 4.5 +- 1.0 slow rotators with a distribution in magnitude similar to those in the Virgo cluster. The overall slow rotator fraction of our Abell 1689 sample is 0.15 +- 0.03, the same as in Virgo using our selection criteria. This suggests that the fraction of slow rotators in a cluster is not strongly dependent on its density. However, within Abell 1689, we find that the fraction of slow rotators increases towards the centre, as was also found in the Virgo cluster.Comment: Accepted by MNRA

The Influence of Large-Scale Structure on Halo Shapes and Alignments

Alignments of galaxy clusters (the Binggeli effect), as well as of galaxies themselves have long been studied both observationally and theoretically. Here we test the influence of large-scales structures and tidal fields on the shapes and alignments of cluster-size and galaxy-size dark matter halos. We use a high-resolution N-body simulation of a $\Lambda$CDM universe, together with the results of Colberg et al. (2005), who identified filaments connecting pairs of clusters. We find that cluster pairs connected by a filament are strongly aligned with the cluster-cluster axis, whereas unconnected ones are not. For smaller, galaxy-size halos, there also is an alignment signal, but its strength is independent of whether the halo is part of an obvious large-scale structure. Additionally, we find no measureable dependence of galaxy halo shape on membership of a filament. We also quantify the influence of tidal fields and find that these do correlate strongly with alignments of halos. The alignments of most halos are thus caused by tidal fields, with cluster-size halos being strongly aligned through the added mechanism of infall of matter from filaments.Comment: 8 pages, 6 figures, accepted for publication in MNRA

Mark correlations: relating physical properties to spatial distributions

Mark correlations provide a systematic approach to look at objects both distributed in space and bearing intrinsic information, for instance on physical properties. The interplay of the objects' properties (marks) with the spatial clustering is of vivid interest for many applications; are, e.g., galaxies with high luminosities more strongly clustered than dim ones? Do neighbored pores in a sandstone have similar sizes? How does the shape of impact craters on a planet depend on the geological surface properties? In this article, we give an introduction into the appropriate mathematical framework to deal with such questions, i.e. the theory of marked point processes. After having clarified the notion of segregation effects, we define universal test quantities applicable to realizations of a marked point processes. We show their power using concrete data sets in analyzing the luminosity-dependence of the galaxy clustering, the alignment of dark matter halos in gravitational $N$-body simulations, the morphology- and diameter-dependence of the Martian crater distribution and the size correlations of pores in sandstone. In order to understand our data in more detail, we discuss the Boolean depletion model, the random field model and the Cox random field model. The first model describes depletion effects in the distribution of Martian craters and pores in sandstone, whereas the last one accounts at least qualitatively for the observed luminosity-dependence of the galaxy clustering.Comment: 35 pages, 12 figures. to be published in Lecture Notes of Physics, second Wuppertal conference "Spatial statistics and statistical physics

Ionized nebulae surrounding brightest cluster galaxies

We present IFU observations of six emission-line nebulae that surround the central galaxy of cool core clusters. Qualitatively similar nebulae are observed in cool core clusters even when the dynamics and possibly formation and excitation source are different. Evidence for a nearby secondary galaxy disturbing a nebula, as well as AGN and starburst driven outflows are presented as possible formation mechanisms. One nebula has a rotation velocity of the same amplitude as the underlying molecular reservoir, which implies that the excitation or formation of a nebula does not require any disturbance of the molecular reservoir within the central galaxy. Bulk flows and velocity shears of a few hundred km/s are seen across all nebulae. The majority lack any ordered rotation, their configurations are not stable so the nebulae must be constantly reshaping, dispersing and reforming. The dimmer nebulae are co-spatial with dust features whilst the more luminous are not. Significant variation in the ionization state of the gas is seen in all nebulae through the non-uniform [NII]/H_alpha ratio. There is no correlation between the line ratio and H_alpha surface brightness, but regions with excess blue or UV light have lower line ratios. This implies that UV from massive, young stars act in combination with an underlying heating source that produces the observed low-ionization spectra.Comment: 12 pages, accepted for publication in MNRA