Customisable Hardware Compilation

Hardware compilers for high-level languages are increasingly recognised to be the key to reducing the productivity gap for advanced circuit development in general, and for reconfigurable designs in particular. This paper explains how customisable frameworks for hardware compilation can enable rapid design exploration, and reusable and extensible hardware optimisation. It describes such a framework, based on a parallel imperative language, which supports multiple levels of design abstraction, transformational development, optimisation by compiler passes, and metalanguage facilities. Our approach has been used in producing designs for applications such as signal and image processing, with different trade-offs in performance and resource usage.     

Characterization of Condensed Tannins Purified From Legume Forages: Chromophore Production,Protein Precipitation,and Inhibitory Effects on Cellulose Digestion

To identify simple screening tools for selecting condensed tannin (CT)-containing forages as candidate sources for further study, CT were isolated from nine legumes, and their molecular weights (MW), chromophore production, capacity to precipitate bovine serum albumin (BSA) and Fraction 1 protein (Rubisco) isolated from alfalfa, and inhibition of filter paper digestion were compared. Sources were as follows: leaves of sericea lespedeza (Lespedeza cuneata Dum.-Cours.), crown vetch (Coronilla varia L.), and sainfoin (Onobrychis viciifolia Scop.); stems of hedysarum (Hedysarum alpinum L.); seeds of alfalfa (Medicago sativa L.); and whole plants of birdsfoot trefoil (Lotus corniculatus var. corniculatus L.) and three varieties of big trefoil (Lotus pedunculatus Cav.), viz., Lotus uliginosus Schkuhr, L. uliginosus var. glabriusculus, and L. uliginosus var. villosus. Molecular weights and sizes (degrees of polymerization) of the CT varied considerably within and among plant species. Average MW ranged from 3036 Da (crown vetch) to 7143 Da (lespedeza). All CT exhibited greater capacity (w/w basis) to bind alfalfa Rubisco than BSA. Relative astringencies (μg CT required to precipitate 1 mg protein) against BSA ranged from 262.5 for CT from lespedeza to 435.5 for CT from L. corniculatus, and against Rubisco, from 49.6 (sainfoin) to 108.2 (alfalfa seed). Including CT at 300 μg/ml in cultures of Fibrobacter succinogenes reduced digestion of cellulose filter paper by 19.8% (sainfoin) to 92.4% (crown vetch) and increased the specific activity of cell-associated endoglucanase. There were no correlations between inhibitory effects of CT on filter paper digestion and (1) chromophore formation during CT assay by butanol–HCl, vanillin–HCl, or H₂SO₄; (2) precipitation of BSA or alfalfa Rubisco; and (3) MW of CT. The most inhibitory CT for cellulose digestion included those with broad and with narrow MW distributions. Sainfoin was the most desirable source of CT, as it had the highest capacity to bind alfalfa protein and was least inhibitory to cellulose digestion by F. succinogenes. This study suggests that these properties are not easily defined via chemical means, and that biological assays using rumen bacteria may help identify those CT with properties of nutritional interest.     

Dual-spatial integration for longitudinal localization of inclusions in turbid media

We introduce a technique called dual-spatial integration (DSI) that is used to isolate and enhance inclusions that differ only by their longitudinal placement within a scattering medium. DSI uses three different source-detector configurations to section a scattering medium into three longitudinal zones. This sectioning permits the extraction of structures close to surfaces and the enhancement of those structures located in the central part of the medium. Both the simulation and the experimental results indicate that DSI has potential interest for applications in biomedical imaging such as optical mammography.     

A revised mono-dimensional particle bed model for fluidized beds

The formulation of the equations of change proposed by Foscolo and Gibilaro in their original mono-dimensional particle bed model (PBM) for the prediction of the fluid-bed stability of Geldart's group A powders has been revisited along with the relevant closure relationships. The buoyancy has been expressed in accordance with its “classical” definition, which regards it as being equal to the weight of the fluidizing fluid displaced by the particle phase. A new constitutive equation has been developed for the drag force; this proves more accurate than the expression used in the original PMB particularly in the intermediate flow regimes comprised between the viscous and inertial ones. The “elastic” force has been estimated by employing a rigorous approach which needs not resort to equilibrium-based relations. The result, enhanced in accuracy and breadth of validity, considers “elastic” force and drag force proportional. The equations of change themselves have been partly revised. The pressure gradient is no longer shared by the two phases in proportion to their volume fractions, but has been accounted for only in the continuous one. Conversely, the “elastic” force has been included, with opposite signs, in the linear momentum equations pertaining to both phases, so that the principle of action and reaction, to which the force is subjected, is fulfilled. The revised model has been validated by performing a fluid-bed stability analysis on a wide range of Geldart's group A powders at different operating temperatures. Predicted values for the minimum bubbling voidage estimated by means of the revised model have been compared with experimental values and with predictions from both the original Foscolo and Gibilaro model and that previously revised by Jean and Fan. The latter has been found to be always in good agreement with the model proposed here, whereas the former has seemed to somewhat underestimate the bed minimum bubbling voidage thus anticipating the transition between homogeneous and bubbling fluidization. All of the models have proved to yield predictions whose validity is strongly dependent on the particular powder in hand and on the operating conditions considered.     

Polyurethane-poly(methyl methacrylate) interpenetrating polymer networks: 1. Early steps and kinetics of network formation; intersystem grafting

Several side-reactions occurring during the early stages of the formation of polyurethane-poly(methyl methacrylate) interpenetrating polymer networks (PUR/PAc IPNs) have been examined. Thus, the PUR catalyst, stannous octoate, is able to initiate the polymerization of the methacrylic monomers, or to accelerate it in the presence of the proper initiator of the system, azo-bisisobutyronitrile. Nevertheless, this effect does not influence the overall reaction process. On the other hand, light has to be excluded in order to obtain transparent IPNs. The kinetics of formation of the individual networks have been investigated in experimental conditions as close as possible to the actual preparation of the corresponding IPNs. Intersystem grafting, if any, is very limited and its influence on the mechanical properties may therefore be neglected.     

Behavioral and neuroanatomical effects of prenatal, postnatal, or combined exposure to ethanol in weanling rats.

Separate and combined effects of prenatal and postnatal exposure to ethanol on activity, emotionality, learning, and hippocampal neuroanatomy were examined in infant rats. Neonatal rats from mothers that were fed either a liquid ethanol (E) or control (C) diet were artificially reared on either 3% ethanol (E) or isocaloric maltose/dextrin (C). Pups in 4 treatment groups (EE, EC, CE, and CC) were compared. Differences in activity and emotionality were slight. Ethanol affected both the partial reinforcement acquisition effect and the partial reinforcement extinction effect. Hippocampal cell density (compared with Group CC) showed a 12% reduction in CA1 pyramidal cells and an 11% reduction in mature granule cells in Groups EC and EE; the CA4 area (compared with Group CC) was significantly larger after postnatal exposure (Groups CE and EE). Significant positive correlations were found between rate of extinction after partial reinforcement (PRF) training and CA1 pyramidal cell density in Groups CC and CE. A significant negative correlation was found between extinction rate after PRF training and CA4 area in Group EE. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Lipid composition of bile in morbid obesity before and after jejunoileal bypass surgery

Bile cholesterol, phospholipids, total bile acids, individual bile acids, and fatty acid compositions of bile neutral lipids and phospholipids were analyzed before, at one month and at six months following jejunoileal bypass surgery in a series of morbidly obese patients. Preoperative mole percentages of cholesterol and lithogenic indices were high, indicating that biles were supersaturated with cholesterol and outside the micellar solubility zone when plotted on triangular coordinates. At the one month post-operative period percentages of cholesterol and lithogenic indices were significantly increased as compared to the pre-operative state. At six months post-operatively these values had decreased to approximately the pre-operative levels. No changes were observed in percentages of lithocholic acid, but deoxycholic acid decreased to markedly low levels at one month and remained low at the six month post-operative interval. Relative proportions of cholic acid increased, and the ratio of cholic to chenodeoxycholic acid was significantly increased at both post-operative intervals. No significant changes were noted in bile neutral lipid or phospholipid fatty acid composition, indicating that no depletion of essential fatty acids had occurred.