Recherche sur la reconnaissance visuelle de mots: De l’apprentissage verbal au traitement parallèle réparti.

Over the past 30 yrs, research on visual word recognition has contributed greatly to the understanding of how information is processed, represented, and accessed in the cognitive system. Today, word recognition continues to serve as a rich domain for modelling and investigating core issues in cognition. In addition, research on word recognition has been used to improve assessment and instruction of reading for children and adults. This article provides a brief overview of some trends and developments in word recognition research over the past few decades. This overview is not meant to be exhaustive (or unbiased); it is intended to give readers from outside the area a feel for why word recognition is such an important domain for cognitive research. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Manganese superoxide dismutase (MnSOD) genetic polymorphisms, dietary antioxidants, and risk of breast cancer

Oxidative stress, resulting from the imbalance between prooxidant and antioxidant states, damages DNA, proteins, cell membranes, and mitochondria and seems to play a role in human breast carcinogenesis. Dietary sources of antioxidants (chemical) and endogenous antioxidants (enzymatic), including the polymorphic manganese superoxide dismutase (MnSOD), can act to reduce the load of oxidative stress. We hypothesized that the valine-to-alanine substitution that seems to alter transport of the enzyme into the mitochondrion, changing its efficacy in fighting oxidative stress, was associated with breast cancer risk and that a diet rich in sources of antioxidants could ameliorate the effects on risk. Data were collected in a case-control study of diet and breast cancer in western New York from 1986 to 1991. Caucasian women with incident, primary, histologically confirmed breast cancer were frequency-matched on age and county of residence to community controls. Blood specimens were collected and processed from a subset of participants in the study (266 cases and 295 controls). Using a RFLP that distinguishes a valine (V) to alanine (A) change in the -9 position in the signal sequence of the protein for MnSOD, we characterized MnSOD genotypes in relation to breast cancer risk. We also evaluated the effect of the polymorphism on risk among low and high consumers of fruits and vegetables. Premenopausal women who were homozygous for the A allele had a 4-fold increase in breast cancer risk in comparison to those with 1 or 2 V alleles (odds ratio, 4.3; 95% confidence interval, 1.7-10.8). Risk was most pronounced among women below the median consumption of fruits and vegetables and of dietary ascorbic acid and alpha-tocopherol, with little increased risk for those with diets rich in these foods. Relationships were weaker among postmenopausal women, although the MnSOD AA genotype was associated with an almost 2-fold increase in risk (odds ratio, 1.8; confidence interval, 0.9-3.6). No appreciable modification of risk by diet was detected for these older women. These data support the hypothesis that MnSOD and oxidative stress play a significant role in breast cancer risk, particularly in premenopausal women. The finding that risk was greatest among women who consumed lower amounts of dietary antioxidants and was minimal among high consumers indicates that a diet rich in sources of antioxidants may minimize the deleterious effects of the MnSOD polymorphism, thereby supporting public health recommendations for the consumption of diets rich in fruits and vegetables as a preventive measure against cancer.     

Contemporary Change and the Housebuilding Industry: Concentration and Standardisation in Production

This paper examines the process of change and concentration within the private-sector housebuilding industry over the past 15 years, and assesses the implications for the production of new housing in terms of standard house types. Changes in the housebuilding industry are analysed utilising secondary data, based upon annual dwelling completions, focusing upon firms producing in excess of 1000 dwelling units per annum. Problems associated both with the adequate classification of firms and of constructing typologies are commented upon. It is concluded that the process of concentration observed in the 1970s has continued at an accelerating pace, and that the housebuilding industry is now dominated by large firms which have a predominantly specialised character to an extent not hitherto observed in post-war Britain. The implications for one aspect of standardisationin production-the utilisation of standard house types-are assessed by means of a national questionnaire of housebuilding firms. Analysis based upon large housebuilding firms confirms a more extensive use of standard house types than hitherto, with consumer flexibility restricted to internal non-structural features rather than external aspects of the dwelling. Provisional reasons for the expansion of standard house types are adduced, and related to the changing structure of the housebuilding industry.     

Na incorporation in Mo and CuInSe2 from production processes

Results of characterization of thin films of Mo deposited by DC magnetron sputtering on soda-lime glass (Mo/SLG) and CuInSe₂ (CIS) on Mo/SLG are presented. The primary objective of the work was to clarify the factors determining the concentration of Na in commercial-grade CIS. Mo films were deposited by three laboratories manufacturing CIS thin film solar cells. Analysis was by secondary ion mass spectrometry, scanning electron microscopy and X-ray diffraction. Changes in Mo deposition parameters in general affected the Na level but there was no obvious link to any single Mo deposition parameter. Oxygen content directly affected the Na level. The Na behavior was not obviously connected to film preferred orientation. Selenization of the Mo layers was also examined. Elemental Se vapor was found to produce significantly less selenization than H₂Se. The amount of selenization was also strongly dependent upon Mo deposition conditions, although a specific source of the change in reaction rate was not found. Na distributions in the CIS deposited on the Mo were not limited by the diffusivity of the Na. The Na concentration in the CIS was increased by annealing the Mo films both with and without intentionally added Na. The Na level in the CIS appears to be set more by the CIS deposition process than by the Na concentration in the Mo so long as the Mo contains sufficient Na to saturate the available sites in the CIS.     

Design,development, construction and operation of a novel metal hydride compressor

Metal Hydride Compressors (MHC) is a promising technology for thermal compression of hydrogen. Besides the absence of a necessity for significant mechanical or electrical energy input, this type of compressor has the advantage that no moving parts are involved. A brief review on the reported experimental set ups of metal hydride compressors is carried out and compared to the metal hydride compressor developed and constructed by HYSTORE Technologies Ltd in Cyprus. The compressor built by HYSTORE consists of 6 stages using AB₂ and AB₅ – type metal hydride alloys. The MHC is operated between 10 C and 80 °C, which is a temperature range that can be supplied by solar thermal collectors. Furthermore, the experimental results showed, that even lower temperatures of 17 C are sufficient thus reducing the demand for cooling capacity. During the operation, the compressor achieved stable compression of hydrogen from 7 bar more than 220 bar. The specific productivity of the compressor achieved values up to 67.2 l_H2 kg^?1 h^?1.     

An in situ method for measuring acid loss from polymer films

This article reports an in situ approach to studying acid loss from polymer (films of the type used in microlithiography. We developed a method which makes use of the dye coumarin 6 (C6) which has absorption characteristics which change dramatically as a result of acid‐induced changes in its prototropic forms. Acid loss from polymer films containing C6 is accompanied by its deprotonation, which is signaled by a change in the absorption of the film. This technique provides kinetic data describing acid loss from polymer films. Acid loss is a function of both acid volatilization from sites at the surface of the film as well as diffusional processes within the film. Under controlled conditions, acid loss obeys first‐order kinetics, and the half‐lives, τ_1/2, of acids in phenolic and acrylate polymer films were determined. We studied the effects of temperature, acid structure, polymer structure, and T_g on the τ_1/2 values obtained. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 1897–1905, 2000     

Advances in PolyNIMMO Composite Gun Propellants

Efforts to develop very high energy tank gun propellants based on traditional double or triple base propellant technology have often failed to deliver the low vulnerability required in Insensitive Munitions. One strand of the United Kingdom's formulation research programme has focused on the alternative technology of composite propellants. A range of composite LOVA propellants based on the energetic binder polyNIMMO in combination with various fillers and plasticisers has been examined. Assessment of their vulnerability in the UK Small Scale Shaped Charge Attack test has shown correlations linked both to the choice of filler and to the volume percentage of filler present. Through a fuller understanding of the factors involved it has been shown to be possible to formulate propellants with an impetus of up to 1300 kJ/kg which still show a low response to shaped charge attack. This and previous studies have also identified the effect of grain geometry and web size on vulnerability. Since these parameters are dictated by ballistic considerations a thorough understanding of the ballistic behaviour of this new class of materials is particularly important. Vulnerability and ballistic considerations are presented and discussed.     

Agricultural by-products as granular activated carbons for adsorbing dissolved metals and organics

Surplus, low value agricultural by-products can be made into granular activated carbons (GACs) which are used in environmental remediation. This study characterized and evaluated GACs, made from these feedstocks, as effective removers of organics and metals from water. The by-products included soft lignocellulosics such as rice straw, soybean hull, sugarcane bagasse, peanut shell, and harder materials such as pecan and walnut shells. The softer materials were combined with a binder, molasses, to produce briquettes and pellets. The precursors were CO₂- or steam-activated, and subsequent treatments included oxidation to enhance metal adsorption. Many of the GACs had acceptable physical GAC attributes, such as durability, for commercial usage. GACs made from pecan and walnut shells adsorbed higher levels of benzene, toluene, methanol, acetonitrile, acetone, and 1,4-dioxane from an aqueous mixture than commercial GACs. Neither CO₂ nor steam activation was particularly advantageous in enhancing metal adsorption. Oxidation using O₂–N₂ gas increased metal adsorption while (NH₄)S₂O₈ solution did not. In a copper solution, oxidized GACs made from soybean hull had three to four times the Cu(II) adsorption capacity of metal-adsorbing, commercial GACs. Oxidized GACs made from soybean hull, sugarcane bagasse, peanut shell, and rice straw adsorbed from a mixture higher amounts of Pb(II), Cu(II), Ni(II), Cd(II) and Zn(II) than any commercial GACs. Commercial GACs adsorbed only Pb(II), Cu(II) and Cd(II). The GACs made from the agricultural by-products have considerable potential for adsorption of organics and metals of environmental concern. © 1998 SCI.     

A rapid determination of the total sugar content and the average inulin chain length in roots of chicory (Cichorium intybusL)

A method is proposed to the chicory breeder for the fast screening of total sugar content and average inulin chain length of lots of chicory roots. The determination of the refractive index of the chicory root juice by refractometer is the first step. This rapid analysis gives a good estimation of the total sugar content (r=0·85; RSD=3·8%). In the next step extracts of chicory roots with a high total sugar content are hydrolysed and analysed by chromatography. The calculated fructose/glucose ratio predicts the average inulin chain length well (r=0·91; RSD=5·3%). The molecular weight distribution of the inulin was analysed by anion exchange HPLC with pulsed amperometric detection. © 1998 SCI