BSP Functional Programming: Examples of a Cost Based Methodology

Abstract. Bulk-Synchronous Parallel ML (BSML) is a functional data-parallel language for the implementation of Bulk-Synchronous Parallel (BSP) algorithms. It makes an estimation of the execution time (cost) possible. This paper presents some general examples of BSML programs and a comparison of their predicted costs with the measured execution time on a parallel machine

New results on rewrite-based satisfiability procedures

Program analysis and verification require decision procedures to reason on theories of data structures. Many problems can be reduced to the satisfiability of sets of ground literals in theory T. If a sound and complete inference system for first-order logic is guaranteed to terminate on T-satisfiability problems, any theorem-proving strategy with that system and a fair search plan is a T-satisfiability procedure. We prove termination of a rewrite-based first-order engine on the theories of records, integer offsets, integer offsets modulo and lists. We give a modularity theorem stating sufficient conditions for termination on a combinations of theories, given termination on each. The above theories, as well as others, satisfy these conditions. We introduce several sets of benchmarks on these theories and their combinations, including both parametric synthetic benchmarks to test scalability, and real-world problems to test performances on huge sets of literals. We compare the rewrite-based theorem prover E with the validity checkers CVC and CVC Lite. Contrary to the folklore that a general-purpose prover cannot compete with reasoners with built-in theories, the experiments are overall favorable to the theorem prover, showing that not only the rewriting approach is elegant and conceptually simple, but has important practical implications.Comment: To appear in the ACM Transactions on Computational Logic, 49 page

Quaternary glacial history of the Mediterranean mountains

Glacial and periglacial landforms are widespread in the mountains of the Mediterranean region. The evidence for glacial and periglacial activity has been studied for over 120 years and it is possible to identify three phases of development in this area of research. First, a pioneer phase characterized by initial descriptive observations of glacial landforms; second, a mapping phase whereby the detailed distribution of glacial landforms and sediments have been depicted on geomorphological maps; and, third, an advanced phase characterized by detailed understanding of the geochronology of glacial sequences using radiometric dating alongside detailed sedimentological and stratigraphical analyses. It is only relatively recently that studies of glaciated mountain terrains in the Mediterranean region have reached an advanced phase and it is now clear from radiometric dating programmes that the Mediterranean mountains have been glaciated during multiple glacial cycles. The most extensive phases of glaciation appear to have occurred during the Middle Pleistocene. This represents a major shift from earlier work whereby many glacial sequences were assumed to have formed during the last cold stage. Glacial and periglacial deposits from multiple Quaternary cold stages constitute a valuable palaeoclimatic record. This is especially so in the Mediterranean mountains, since mountain glaciers in this latitudinal zone would have been particularly sensitive to changes in the global climate system. © 2006 Edward Arnold (Publishers) Ltd

Improving social dialogue: What employers expect from employee representatives

The model of social dialogue in organisations between management and employees is facing unprecedented challenges, and changing rapidly. In this new context of labour relations, experiences and expectations of each other are key drivers for the primary parties within this social dialogue. There has been little systematic research investigating the conditions for constructive social dialogue, particularly when it comes to 'soft factors', such as perceived competences, trust, influence and conflict behaviours. Addressing these issues based on theories of conflict, trust and influence, this article investigates the experiences and expectations of employee representatives (ERs) by human resource (HR) managers, their counterparts in social dialogue. The results of surveys conducted in 11 European countries indicate that, overall, employers found a model of structured dialogue with elected employee representatives useful. Furthermore, competences of ERs, cooperative conflict behaviours, informal relations and trust promoted the influence of ERs on organisational decision making and the quality of these decisions. We discuss implications for different systems of industrial relations

G2 checkpoint abrogation and checkpoint kinase-1 targeting in the treatment of cancer

Rigorous quality control steps, termed checkpoints, tightly regulate progression through the cell cycle. DNA-damaging chemotherapy and radiation activate functional cellular checkpoints. These checkpoints can facilitate DNA repair and promote cell death in unrepaired cells. There are at least three DNA damage checkpoints – at G1/S, S, and G2/M – as well as a mitotic spindle checkpoint. Most cancer cells harbour mutations in tumour suppressors and/or oncogenes, which impair certain cell checkpoints. Inhibiting the remaining cell checkpoints – particularly after exposure of cancer cells to chemotherapy and/or radiation – allows cell death, a strategy now being employed in cancer therapeutics. With our increasing knowledge of cell cycle regulation, many compounds have been developed to inhibit specific checkpoint components, particularly at the G2/M transition. One such target is checkpoint kinase-1 (Chk1). We review here the molecular framework of the cell cycle, the rationale for targeting Chk1, the preclinical concepts related to the development of Chk1 inhibitors, and the efficacy and safety results from Chk1 inhibitors now in phase I/II trials

Copernicus Marine Service ocean state report, issue 4

This is the final version. Available from Taylor & Francis via the DOI in this record. FCT/MCTE

Photochemistry of mineral dust surface as a potential atmospheric renoxification process

Ndour, Marieme Conchon, Pierre D'Anna, Barbara Ka, Oumar George, ChristianThe nitrate formation on dust particles is considered as a sink for atmospheric NOy (such as HNO3). However mineral dust is shown here to be an effective photocatalyst for transformation of nitrate anions into NO and NO2, without involving its photolysis. The photodecomposition of NO3- at the surface of synthetic mineral dust samples of SiO2, TiO2, mixed TiO2-SiO2 and authentic sand doped with 6% NO3- was studied by means of a flow-tube at 298 K with UV-illumination in the 340-420 nm range at relative humidities between 5 and 80%. Both NO and NO2 are observed during irradiation of films composed of either mixed TiO2-SiO2, pure TiO2 and authentic minerals from the Sahara. The relative humidity strongly affects the concentration of NOx released into the gas phase. The photoinduced nitrate conversion into NOx is discussed as being a potential renoxification process of the atmosphere. Citation: Ndour, M., P. Conchon, B. D'Anna, O. Ka, and C. George (2009), Photochemistry of mineral dust surface as a potential atmospheric renoxification process, Geophys. Res. Lett., 36, L05816, doi: 10.1029/2008GL036662

Optimization of a micronekton model with acoustic data

© 2014 International Council for the Exploration of the Sea 2014. All rights reserved. For Permissions, please email: [email protected] the pelagic foodweb, micronekton at the mid-trophic level (MTL) are one of the lesser known components of the ocean ecosystem despite being a major driver of the spatial dynamics of their predators, of which many are exploited species (e.g. tunas). The Spatial Ecosystem and Population Dynamics Model is one modelling approach that includes a representation of the spatial dynamics of several epi- and mesopelagic MTL functional groups. The dynamics of these groups are driven by physical (temperature and currents) and biogeochemical (primary production, euphotic depth) variables. A key issue to address is the parameterization of the energy transfer from the primary production to these functional groups. We present a method using in situ acoustic data to estimate the parameters with a maximum likelihood estimation approach. A series of twin experiments conducted to test the behaviour of the model suggested that in the ideal case, that is, with an environmental forcing perfectly simulated and biomass estimates directly correlated with the acoustic signal, a minimum of 200 observations over several time steps at the resolution of the model is needed to estimate the parameter values with a minimum error. A transect of acoustic backscatter at 38 kHz collected during scientific cruises north of Hawaii allowed a first illustration of the approach with actual data. A discussion followed regarding the various sources of uncertainties associated with the use of acoustic data in micronekton biomass

Quaternary marine and continental sedimentation in the northern Red Sea and Gulf of Suez (Egyptian coast): influences of rift tectonics, climatic changes and sea-level fluctuations

International audienc