3,840 research outputs found

    Hydrogeological investigations in the Pampa of Argentina

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    The author has identified the following significant results. Satellite imagery in combination with ground investigations allows identification and delineation of differences in the conditions of the near surface ground water (depth to ground water, salinity). The degree of precision achieved is greater than that obtainable by conventional ground survey methods alone

    Insect (Arthropoda: Insecta) Composition in the Diet of Ornate Box Turtles (Terrapene ornata ornata) in Two Western Illinois Sand Prairies, with a New State Record for Cyclocephala (Coleoptera: Scarabaeidae)

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    A study of fecal samples collected over a two-year period from juvenile ornate box turtles (Terrapene ornata ornata Agassiz) revealed diets consisting of six orders of insects representing 19 families. Turtles were reared in captivity from eggs harvested from local, wild populations, and released at two remnant prairies. Identifiable insect fragments were found in 94% of samples in 2013 (n=33) and 96% in 2014 (n=25). Frequency of occurrence of insects in turtle feces is similar to results reported in previous studies of midwestern Terrapene species. A comparison of insect composition presented no significant difference between release sites. There is no significant difference in consumed insect species between turtles released into or outside of a fenced enclosure at the same site. Specimens of Cyclocephala longula LeConte collected during this study represent a new state record for Illinois

    Improving the Accuracy of UK Regulatory Cost Estimates

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    UK Government departments are required to undertake a Regulatory Impact Assessment (RIA) when introducing any policy change that places a burden on businesses, charities, the voluntary sector or individuals. Part of this assessment involves the appraisal of the costs (and benefits) associated with complying with all the available options, as well as the wider economic costs. Recent evidence has suggested that the compliance costs, when assessed ex post, tend to be lower than the ex ante assessment made beforehand (see e.g. Harrington et al 1999). Accurate cost estimates are important as errors can lead to under or over regulation. This, in turn, can result in growth and innovation being hindered or, in the case of under regulation, growth being achieved at the expense of the natural resource base (including human health and well being). In order to shed more light on the validity of RIA cost estimates and identify ways of improving their accuracy, Defra decided to commission a study comparing the ex ante and ex post costs of complying with regulatory changes. A total of eight case studies were carried out for this study, covering a range of recent environmental, agricultural and food-related regulations in the UK. Preliminary findings of this study indicate that while ex ante costs are often overestimated, there can also be significant underestimates. Reasons for errors in cost estimation are discussed and strategies for improving their accuracy suggested.Public Economics,

    On Probabilistic Applicative Bisimulation and Call-by-Value λ\lambda-Calculi (Long Version)

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    Probabilistic applicative bisimulation is a recently introduced coinductive methodology for program equivalence in a probabilistic, higher-order, setting. In this paper, the technique is applied to a typed, call-by-value, lambda-calculus. Surprisingly, the obtained relation coincides with context equivalence, contrary to what happens when call-by-name evaluation is considered. Even more surprisingly, full-abstraction only holds in a symmetric setting.Comment: 30 page

    The Green Lab: Experimentation in Software Energy Efficiency

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    Software energy efficiency is a research topic where experimentation is widely adopted. Nevertheless, current studies and research approaches struggle to find generalizable findings that can be used to build a consistent knowledge base for energy efficient software. To this end, we will discuss how to combine the traditional hypothesis-driven (top-down) approach with a bottom-up discovery approach. In this technical briefing, participants will learn the challenges that characterize the research in software energy efficiency. They will experience the complexity in this field and its implications for experimentatio

    Synchronizing Sequencing Software to a Live Drummer

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    Copyright 2013 Massachusetts Institute of Technology. MIT allows authors to archive published versions of their articles after an embargo period. The article is available at

    From cosmic deceleration to acceleration: new constraints from SN Ia and BAO/CMB

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    We use type Ia supernovae (SN Ia) data in combination with recent baryonic acoustic oscillations (BAO) and cosmic microwave background (CMB) observations to constrain a kink-like parametrization of the deceleration parameter (qq). This qq-parametrization can be written in terms of the initial (qiq_i) and present (q0q_0) values of the deceleration parameter, the redshift of the cosmic transition from deceleration to acceleration (ztz_t) and the redshift width of such transition (τ\tau). By assuming a flat space geometry, qi=1/2q_i=1/2 and adopting a likelihood approach to deal with the SN Ia data we obtain, at the 68% confidence level (C.L.), that: zt=0.560.10+0.13z_t=0.56^{+0.13}_{-0.10}, τ=0.470.20+0.16\tau=0.47^{+0.16}_{-0.20} and q0=0.310.11+0.11q_0=-0.31^{+0.11}_{-0.11} when we combine BAO/CMB observations with SN Ia data processed with the MLCS2k2 light-curve fitter. When in this combination we use the SALT2 fitter we get instead, at the same C.L.: zt=0.640.07+0.13z_t=0.64^{+0.13}_{-0.07}, τ=0.360.17+0.11\tau=0.36^{+0.11}_{-0.17} and q0=0.530.13+0.17q_0=-0.53^{+0.17}_{-0.13}. Our results indicate, with a quite general and model independent approach, that MLCS2k2 favors Dvali-Gabadadze-Porrati-like cosmological models, while SALT2 favors Λ\LambdaCDM-like ones. Progress in determining the transition redshift and/or the present value of the deceleration parameter depends crucially on solving the issue of the difference obtained when using these two light-curve fitters.Comment: 25 pages, 9 figure

    The Power of Non-Determinism in Higher-Order Implicit Complexity

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    We investigate the power of non-determinism in purely functional programming languages with higher-order types. Specifically, we consider cons-free programs of varying data orders, equipped with explicit non-deterministic choice. Cons-freeness roughly means that data constructors cannot occur in function bodies and all manipulation of storage space thus has to happen indirectly using the call stack. While cons-free programs have previously been used by several authors to characterise complexity classes, the work on non-deterministic programs has almost exclusively considered programs of data order 0. Previous work has shown that adding explicit non-determinism to cons-free programs taking data of order 0 does not increase expressivity; we prove that this - dramatically - is not the case for higher data orders: adding non-determinism to programs with data order at least 1 allows for a characterisation of the entire class of elementary-time decidable sets. Finally we show how, even with non-deterministic choice, the original hierarchy of characterisations is restored by imposing different restrictions.Comment: pre-edition version of a paper accepted for publication at ESOP'1
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