Modelling Long-memory Time Series with Finite or Infinite Variance: a General Approach

We present a class of generalized fractional filters which is stable with respect to series and parallel connection. This class extends the so-called fractional ARUMA and fractional ARMA filters previously introduced by e.g. Goncalves (1987) and Robinson (1994) and recently studied by Giraitis and Leipus (1995) and Viano et al. (1995). Conditions for the existence of the induced stationary S α S and L ² processes are given. We describe the asymptotic dependence structure of these processes via the codifference and the covariance sequences respectively. In the L ² case, we prove the weak convergence of the normalized partial sums.     

A three-dimensional construction of the active site (region 507749) of human neutral endopeptidase (EC.3.4.24.11)

A three-dimensional model of the 507–749 region of neutralendopeptidase-24.11 (NEP; E.C.3.4.24.11) was constructed integratingthe results of secondary structure predictions and sequencehomologies with the bacterial endopeptidase thermolysin. Additionaldata were extracted from the structure of two other metalloproteases,astacin and stromelysin. The resulting model accounts for themain biological properties of NEP and has been used to describethe environment close to the zinc atom defining the catalyticsite. The analysis of several thiol inhibitors, complexed inthe model active site, revealed the presence of a large hydrophobicpocket at the S₁' subsite level. This is supported by the natureof the constitutive amino acids. The computed energies of boundinhibitors correspond with the relative affinities of the stereoisomersof benzofused macrocycle derivatives of thiorphan. The modelcould be used to facilitate the design of new NEP inhibitors,as illustrated in the paper.     

Energy saving potential and strategies for electric lighting in future North European, low energy office buildings: A literature review

This article presents key energy use figures and explores the energy saving potential for electric lighting in office buildings based on a review of relevant literature, with special emphasis on a North European context. The review reveals that theoretical calculations, measurements in full-scale rooms and simulations with validated lighting programs indicate that an energy intensity of around 10 kWh/m² yr is a realistic target for office electric lighting in future low energy office buildings. This target would yield a significant reduction in energy intensity of at least 50% compared to the actual average electricity use for lighting (21 kWh/m² yr in Sweden). Strategies for reducing energy use for electric lighting are presented and discussed, which include: improvements in lamp, ballast and luminaire technology, use of task/ambient lighting, improvement in maintenance and utilization factor, reduction of maintained illuminance levels and total switch-on time, use of manual dimming and switch-off occupancy sensors. Strategies based on daylight harvesting are also presented and the relevant design aspects such as effects of window characteristics, properties of shading devices, reflectance of inner surfaces, ceiling and partition height are discussed.     

Review of Les troubles obsessionels compulsifs: Principes, thérapies, applications (2e édition).

Reviews the book, Les troubles obsessionels compulsifs: Principes, thérapies, applications (2e édition) by Martine Bouvard (2006). This book is addressed to clinicians who wish to apply cognitive-behavioral therapy (CBT) to patients suffering from obsessive-compulsive disorder (OCD). There are ten chapters, each one written by different authors according to their respective fields of expertise. The reviewer praises the editor for compiling a comprehensive guide to CBT treatment for OCD, but did not think there was enough of a difference between the 1st and 2nd editions to warrant a new edition. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Rheological study of crystallization behavior of polylactide and its flax fiber composites

In this work, the isothermal crystallization of compounded polylactide (PLA) and PLA-flax fiber composites was investigated by means of rheometry using small amplitude oscillatory shear (SAOS). The rheological measurements were carried out in parallel plate flow geometry at a crystallization temperature (T _c ) ranging from 110 to 140 °C. In addition, the effect of shear on polylactide crystallization was studied at 140 °C. Rheological behavior in the molten state was employed to predict the initial viscosity in the T _c interval by applying time-temperature superposition, and results were found to be in agreement with experimental values at low crystallization rates. A simple empirical model was also used to determine the crystallization induction time in a wide range of supercooling conditions. The evolution of the complex viscosity under quiescent conditions of the PLA-based flax-fiber composite indicated an enhancement of the rate of crystallization due to the presence of cellulosic fibers, while shear flow effectively accelerated the crystallization of neat PLA. This work shows that rheometry is an accurate technique for analyzing the crystallization behavior of polymers in a temperature range which presents low to very low crystallization rates, which is the case for PLA at T ≥ 130 °C.     

Crystallization of polylactide films: An atomic force microscopy study of the effects of temperature and blending

Surface crystallinity on films of poly(l-lactide), poly(l/d-lactide) and their blends with poly(d-lactide) was studied. The isothermal spherulitic growth rate and its dependence on temperature were studied using tapping mode atomic force microscopy and ex situ isothermal crystallization. Using this technique, it is possible to extend spherulitic growth rate measurements to the region of significantly higher supercooling where nucleation concentration makes the use of in situ hot stage optical microscopy impossible. It was confirmed that while a poly(l/d-lactide) copolymer exhibits the typical “bell” shaped crystallization rate–temperature dependence, poly(l-lactide) exhibits a nonsymmetrical behavior having two crystallization rate maxima at 105 °C and 130 °C. As expected, the spherulitic growth rate of poly(l-lactide) was significantly higher than that of poly(l/d-lactide). The different types of crystalline formations exhibited at the surface of polylactide films are shown and discussed. The crystalline long spacing of poly(l-lactide) was also measured directly using tapping mode AFM and was found to be 19 nm at 165–170 °C. At low supercooling, several different scenarios of individual crystal formation were observed: purely flat-on stacks, purely edge-on stacks and scenarios where edge-on crystals flip to flat-on crystals and vice versa, where flat-on crystals yield edge-on sprouts. The preferred direction of growth of lamellae of both poly(l-lactide) and poly(d-lactide) was found to be counter-clockwise relative to the free surface.Finally, the crystallization kinetics of blends of poly(l-lactide) and poly(l/d-lactide) with poly(d-lactide) were studied. In such blends a triclinic stereocomplex crystalline structure forms between chains of opposite chirality and a pseudo-orthorhombic α-crystal structure forms between chains of like chirality. The presence of the stereocomplex crystals affects both the nucleation and the growth of the α-crystals. In fact depending on the stereocomplex content and the crystallization temperature the α-crystallization can either be enhanced or be inhibited. Interestingly it was found that the presence of the stereocomplex had a much stronger effect on the α-crystallization of poly(l/d-lactide) than on the α-crystallization of poly(l-lactide).     

Impacts d'un programme d'interventions multidimensionnel con?u pour les parents et leur enfant ayant un TDAH sur le stress parental et la relation parent–enfant.

The behaviours that characterize ADHD (Attention-Deficit/Hyperactivity Disorder) often lead to impairments in the parent–child relationship and contribute to increased stress amongst parents of children with the disorder. The main objective of this research is to evaluate the impact of a multimodal intervention program (Multi-Propulsions) on parental stress and on parent–child relationship as perceived by parents. The program combines: (1) a cognitive-behavioural program for ADHD children including physical activities in an adapted gymnasium; (2) a cognitive-behavioural parent training program; (3) joint activities with children and parents under the supervision of professionals. Sample contents 23 families with ADHD children aged between 6 and 12 years old from the ADHD clinic of the Rivière-des-Prairies Hospital in Montreal. Participants were randomly assigned to treatment or waiting group. Results highlight the efficiency of Multi-Propulsions program for diminishing parental stress, particularly stress associated with child's characteristics, and these therapeutic gains were maintained four months after the treatment. Furthermore, the results show an improvement in the quality of parent–child relationship. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Self-compiling compilers: An appraisal of their implementation and portability

Self-compiling compilers are compilers written in the programming language they are made to compile. They constitute a very interesting case of portable programs, and are rapidly gaining in popularity. This paper is an attempt to classify and evaluate the different methods which have been used for writing and transporting such compilers, according to numerous and various criteria. The potential implementor is then given an idea of the important factors to be considered when selecting one of the many implementation methods available. The study is centred around a specific case, the programming language Pascal and its many compilers.