Parameter passing in nondeterministic recursive programs

AbstractCall by value and call by name have some subtleties when used in a nondeterministic programming language. A common formalism is used to establish the denotational semantics of recursive programs called by name and called by value. Ashcroft and Hennessy introduced the idea of differentiating between selecting arguments from a set of arguments at the point of invocation and selecting arguments during the run of the procedure. This distinction is shown to be independent of the evaluation according to value or name, giving rise to four possible parameter passing methods, all of which have a suitable least fixed point semantics

Construing and body dissatisfaction in chronic depression: a study of body psychotherapy.

© 2018 Elsevier B.V. All rights reserved.The frequent association of depression with somatic symptoms suggests that body psychotherapy may be an appropriate therapeutic intervention for people with chronic depression. Using a subset of twenty-three participants from a randomized controlled trial that had demonstrated the effectiveness of such an intervention in reducing depressive symptoms, the present study investigated whether it may also impact aspects of construing which have been associated with depression. Patients presenting with chronic depression were randomly allocated to a treatment group or a waiting list group, which received body psychotherapy after a period on a waiting list. Correlations between repertory grid, questionnaire, and visual analogue measures indicated that depression and bodily dissatisfaction were associated with features of the content and structure of construing. There were no significant changes while patients were on the waiting list, but during treatment reduction in depression and bodily dissatisfaction, together with increase in self-esteem and quality of life, were accompanied by an increase in the salience of construing of the bodily self.Peer reviewe

Free upper regular bands

AbstractIn universal domains, the retractions form a fundamental notion of ‘data type’. We define a partial order on the retractions of Scott's domain Pω and completely describe the set of data types which can be generated by an arbitrary chain of such retractions. This set is precisely the free upper regular band over the chain, and is a lattice-ordered semigroup

All Argument Selection May Be Done First ; CU-CS-108-77

There are many presentations of a function in terms of its ‘primitive’ components. These may involve the selection, permutation and duplication of partial results. We show that all argument selection and rearrangement may precede the calculation of the ‘pure’ function, where in no argument rearrangement occurs

The Role of Legal Services in the Antipoverty Program

Large-scale adaptive radiations might explain the runaway success of a minority of extant vertebrate clades. This hypothesis predicts, among other things, rapid rates of morphological evolution during the early history of major groups, as lineages invade disparate ecological niches. However, few studies of adaptive radiation have included deep time data, so the links between extant diversity and major extinct radiations are unclear. The intensively studied Mesozoic dinosaur record provides a model system for such investigation, representing an ecologically diverse group that dominated terrestrial ecosystems for 170 million years. Furthermore, with 10,000 species, extant dinosaurs (birds) are the most speciose living tetrapod clade. We assembled composite trees of 614-622 Mesozoic dinosaurs/birds, and a comprehensive body mass dataset using the scaling relationship of limb bone robustness. Maximum-likelihood modelling and the node height test reveal rapid evolutionary rates and a predominance of rapid shifts among size classes in early (Triassic) dinosaurs. This indicates an early burst niche-filling pattern and contrasts with previous studies that favoured gradualistic rates. Subsequently, rates declined in most lineages, which rarely exploited new ecological niches. However, feathered maniraptoran dinosaurs (including Mesozoic birds) sustained rapid evolution from at least the Middle Jurassic, suggesting that these taxa evaded the effects of niche saturation. This indicates that a long evolutionary history of continuing ecological innovation paved the way for a second great radiation of dinosaurs, in birds. We therefore demonstrate links between the predominantly extinct deep time adaptive radiation of non-avian dinosaurs and the phenomenal diversification of birds, via continuing rapid rates of evolution along the phylogenetic stem lineage. This raises the possibility that the uneven distribution of biodiversity results not just from large-scale extrapolation of the process of adaptive radiation in a few extant clades, but also from the maintenance of evolvability on vast time scales across the history of life, in key lineages

True mid-infrared Pr3+ absorption cross-section in a selenide-chalcogenide host-glass

The mid-infrared (MIR) spans the 3-25 m wavelength range. Rare-earth-ion doped selenide-chalcogenide glasses are being developed for direct-emission MIR fibre lasers. The true Pr3+ absorption cross-section in the 3.5-6 µm wavelength region of a Pr3+-doped (500 ppmw of Pr3+ i.e. 9.47 x 1019 Pr3+ ions cm-3) GeAsGaSe host-glass is presented, after numerically removing the underlying, extrinsic vibrational absorption due to [H-Se-] contamination of the host-glass

True mid-infrared Pr3+ absorption cross-section in a selenide-chalcogenide host-glass

The mid-infrared (MIR) spans the 3-25 m wavelength range. Rare-earth-ion doped selenide-chalcogenide glasses are being developed for direct-emission MIR fibre lasers. The true Pr3+ absorption cross-section in the 3.5-6 µm wavelength region of a Pr3+-doped (500 ppmw of Pr3+ i.e. 9.47 x 1019 Pr3+ ions cm-3) GeAsGaSe host-glass is presented, after numerically removing the underlying, extrinsic vibrational absorption due to [H-Se-] contamination of the host-glass

Promising emission behavior in Pr 3+ /In selenide-chalcogenide-glass small-core step index fiber (SIF)

Selenide-chalcogenide glass, small-core, step-index fiber (SIF), core-doped with Pr3+: 9.51 × 1024 ions m−3 (500 ppmw) is fabricated for the first time with indium to help solubilize Pr3+. Core diameters of 20 or 40 μm are confirmed using scanning electron microscopy and near-field imaging; fibre numerical aperture is ∼0.4. Optical loss is ≥ 4.9 dB m−1 across the 3–9 μm mid-infrared (MIR) spectral range. On pumping at 1.55 μm or 2.013 μm, the SIFs give broad MIR emission across 3.5–6 μm assigned to 3H6 → 3H5 and 3H5 → 3H4. The Pr3+ emission-lifetime at 4.7 μm decreases from bulk-glass (10.1 ± 0.3 ms), to intermediately processed fiber (8.10 ± 0.5 ms) to SIF (7.1 ± 0.5 ms) induced by the processing. On end-pumping SIFs at 2.013 μm, the output pump-power and emission intensity at 4.7 μm became sub-linear and super-linear, respectively, suggesting MIR excited-state saturation is occurring