2,660 research outputs found

    Scientific, Technical and Economic Committee for Fisheries (STECF) - Development of Protocols for Multi-annual Plan Impact Assessments

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    background to aspects of modelling implied by an Impact Assessment. Experience with stakeholder involvement in the development of Multi-Annual Plans was also discussed. The meeting then developed a report framework to deliver the Commission¿s requirement. This report structure was designed to complement the Framework for Evaluations previously developed and extended under SG-MOS 090-02 in Lisbon in November. To test the suitability of the Framework and to determine how to carry out the necessary supporting work four requests, on Celtic Sea herring, Bay of Biscay sole, Haddock to the west of Scotland and Western Waters Access Regime, were briefly examined for scope and approach. Based on the experience gained from these and the general experience of other plans a generic timetable and Terms of Reference were developed.JRC.DG.G.4-Maritime affair

    Selective Predation on the Seeds of Woody Plants

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    Selective predation on the seeds of woody plants. J. Torrey Bot. Soc. 124: 67-70). 1997.-Seed predation may be an important factor influencing the structure of successional plant communities. We used a cafeteria-style experiment, placed in an old field and an early successional forest, to determine predator preferences for seeds of nine species of woody plants. Intensity of seed predation was equivalent in both sites. Seed predators preferred Acer saccharum, flex vertic illata, and Viburnum dentatum, but this was not related to seed mass. Predation intensity was more variable in the old field than in the forest, possibly related to the higher ground-layer heterogeneity of the old field site. We conclude that predator choice will allow some species to escape seed predation, potentially altering future plant community composition

    Selective Predation on the Seeds of Woody Plants

    Get PDF
    Selective predation on the seeds of woody plants. J. Torrey Bot. Soc. 124: 67-70). 1997.-Seed predation may be an important factor influencing the structure of successional plant communities. We used a cafeteria-style experiment, placed in an old field and an early successional forest, to determine predator preferences for seeds of nine species of woody plants. Intensity of seed predation was equivalent in both sites. Seed predators preferred Acer saccharum, flex vertic illata, and Viburnum dentatum, but this was not related to seed mass. Predation intensity was more variable in the old field than in the forest, possibly related to the higher ground-layer heterogeneity of the old field site. We conclude that predator choice will allow some species to escape seed predation, potentially altering future plant community composition

    ALMANACS: A Simulatability Benchmark for Language Model Explainability

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    How do we measure the efficacy of language model explainability methods? While many explainability methods have been developed, they are typically evaluated on bespoke tasks, preventing an apples-to-apples comparison. To help fill this gap, we present ALMANACS, a language model explainability benchmark. ALMANACS scores explainability methods on simulatability, i.e., how well the explanations improve behavior prediction on new inputs. The ALMANACS scenarios span twelve safety-relevant topics such as ethical reasoning and advanced AI behaviors; they have idiosyncratic premises to invoke model-specific behavior; and they have a train-test distributional shift to encourage faithful explanations. By using another language model to predict behavior based on the explanations, ALMANACS is a fully automated benchmark. We use ALMANACS to evaluate counterfactuals, rationalizations, attention, and Integrated Gradients explanations. Our results are sobering: when averaged across all topics, no explanation method outperforms the explanation-free control. We conclude that despite modest successes in prior work, developing an explanation method that aids simulatability in ALMANACS remains an open challenge.Comment: Code is available at https://github.com/edmundmills/ALMANACS}{https://github.com/edmundmills/ALMANAC

    Polaris: Mass and Multiplicity

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    Polaris, the nearest and brightest classical Cepheid, is a member of at least a triple system. It has a wide (1818'') physical companion, the F-type dwarf Polaris B. Polaris itself is a single-lined spectroscopic binary with an orbital period of 30 years (Kamper, 1996, JRASC, 90, 140). By combining {\it Hipparcos} measurements of the instantaneous proper motion with long-term measurements and the Kamper radial-velocity orbit, Wielen et al. (2000, A&A, 360, 399) have predicted the astrometric orbit of the close companion. Using the {\it Hubble Space Telescope} and the Advanced Camera for Surveys' High-Resolution Channel with an ultraviolet (F220W) filter, we have now directly detected the close companion. Based on the Wielen et al. orbit, the {\it Hipparcos} parallax, and our measurement of the separation (0.1760.176'' ±\pm 0.0020.002''), we find a preliminary mass of 5.0 ±\pm 1.5 M_{\odot} for the Cepheid and 1.38 ±\pm 0.61 M_{\odot} for the close companion. These values will be refined by additional {\it HST} observations scheduled for the next 3 years. We have also obtained a {\it Chandra} ACIS-I image of the Polaris field. Two distant companions C and D are not X-rays sources and hence are not young enough to be physical companions of the Cepheid. There is one additional stellar X-ray source in the field, located 253253'' from Polaris A, which is a possible companion. Further investigation of such a distant companion is valuable to confirm the full extent of the system.Comment: submitted to Conference Proceedings of IAU Symp. 24

    Transtensional Rifting in the Late Proto-Gulf of California Near Bahía Kino, Sonora, México

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    The Gulf of California provides an active rift example to test the role of rift obliquity in continental rupture. Continental rifts require focused strain to rupture and form an ocean basin. Strike-slip faults are ubiquitous in oblique rifts and focused transtensional strain adjacent to these faults may be a catalyst for rupture. To test this hypothesis, I completed structural mapping, fault-kinematic analysis, geochronology, basin analysis, and paleomagnetism of pre- and syn-rift rocks exposed in coastal Sonora, México. Sedimentary basins record ~16 km of west-northwest-directed transtension across the Kino-Chueca Shear Zone. Onset of transtension in the study area is estimated to be ca. 7 Ma and lasted for approximately 1 million years. This represents a significant portion (~28%) of plate boundary deformation over this time interval. Dextral shear was progressively localized within this zone of extensional deformation, and together shear and extension acted to focus lithospheric-scale strain into a narrower zone

    Patterns of Mesenchymal Condensation in a Multiscale, Discrete Stochastic Model

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    Cells of the embryonic vertebrate limb in high-density culture undergo chondrogenic pattern formation, which results in the production of regularly spaced “islands” of cartilage similar to the cartilage primordia of the developing limb skeleton. The first step in this process, in vitro and in vivo, is the generation of “cell condensations,” in which the precartilage cells become more tightly packed at the sites at which cartilage will form. In this paper we describe a discrete, stochastic model for the behavior of limb bud precartilage mesenchymal cells in vitro. The model uses a biologically motivated reaction–diffusion process and cell-matrix adhesion (haptotaxis) as the bases of chondrogenic pattern formation, whereby the biochemically distinct condensing cells, as well as the size, number, and arrangement of the multicellular condensations, are generated in a self-organizing fashion. Improving on an earlier lattice-gas representation of the same process, it is multiscale (i.e., cell and molecular dynamics occur on distinct scales), and the cells are represented as spatially extended objects that can change their shape. The authors calibrate the model using experimental data and study sensitivity to changes in key parameters. The simulations have disclosed two distinct dynamic regimes for pattern self-organization involving transient or stationary inductive patterns of morphogens. The authors discuss these modes of pattern formation in relation to available experimental evidence for the in vitro system, as well as their implications for understanding limb skeletal patterning during embryonic development
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