Molecular mechanisms in the control of limb regeneration: the role of homeobox genes

The Ca2+ sensitivity of cardiac myofibrillar force production can be decreased by acidosis or inorganic phosphate (P(i)) and increased by caffeine. To investigate whether the source of tissue influences the potency of these agents, we compared the actions of acidosis (change of pH from 7.0 to 6.2), P(i) and caffeine (both 20 mM) on force production of skinned cardiac muscles from adult ventricle, adult atrium and neonate ventricle of the rat. Maximum Ca(2+)-activated force was reduced by all three interventions and the responses of the different muscle types to a given intervention were similar. Acidosis reduced myofibrillar Ca2+ sensitivity by 1.09 and 1.04 pCa units in adult ventricle and atrium, respectively, and P(i) reduced it by 0.19 and 0.22 pCa units. However, each effect was only one-third as great in the neonate ventricle, which showed falls of 0.33 pCa units for acidosis and 0.06 for P(i). In contrast, caffeine raised the Ca2+ sensitivity by the same amount (approximately 0.4 pCa units) in all three muscle types. The differential effect between adult and neonate seen with both acidosis and P(i) suggests some similarity in the mechanisms by which these factors decrease Ca2+ sensitivity. In contrast, the equal effects of caffeine on neonate and adult suggests that caffeine acts by a completely different mechanism. The lower pH- and P(i)-sensitivity of the neonatal ventricle can help to explain why neonatal and adult myocardium exhibit differential force responses to ischaemia (or hypoxia alone).     

Moral Judgment and Crime Drama: An Integrated Theory of Enjoyment

The article proposes a theoretical framework in which moral reasoning about mediated crime and punishment is defined and combined with existing, affect-driven entertainment theory to yield an integrated theory of enjoyment. The authors analyze how crime dramas serve as statements about justice and then address how moral deliberation about the propriety of those statements impacts enjoyment. The authors report research findings to support the analysis of cognitive processing during crime dramas distinct from affective processing. The article also suggests future means by which the integrated theory of enjoyment can be examined.     

Abrasive wear of dental composite resins

Abrasive wear is a major problem in the application of dental composite resins. In this study the friction and wear behaviours of two types of dental composites: one containing relatively coarse filler particles and some microfillers (Estilux) and another containing only microfiller particles (Durafill), have been investigated by using a scratch testing machine. Experimental results show that the coefficients of friction in both composites are essentially constant for applied loads up to 20 N. The wear resistance of Durafill is better than Estilux. Under the same testing conditions, the size, shape and distribution of the filler particles are more important variables than applied load and sliding speed in controlling the wear mechanism. It is shown that for Estilux, plastic ploughing by the diamond indenter is the predominant mechanism. For Durafill, however, the formation and propagation of tensile cracks on the worn surface is the main wear mechanism. The effects of two different indenters, diamond and enamel, on the basic wear mechanisms are also discussed.     

Two-step parameter extraction procedure with formal optimization for physics-based circuit simulator IGBT and p-i-n diode models

A practical and accurate parameter extraction method is presented for the Fourier-based-solution physics-based insulated gate bipolar transistor (IGBT) and power diode models. The goal is to obtain a model accurate enough to allow switching loss prediction under a variety of operating conditions. In the first step of the extraction procedure, only one simple clamped inductive load test is needed for the extraction of the six parameters required for the diode model and of the 12 and 15 parameters required for the nonpunch-through (NPT) and punch-through (PT) IGBT models, respectively. The second part of the extraction procedure is an automated formal optimization step that refines the parameter estimation. Validation with experimental results from various structures of IGBT demonstrates the accuracy of the proposed IGBT and diode models and the robustness of the parameter extraction method.     

Designing the MPC105 PCI bridge/memory controller

The MPC105 peripheral component interconnection bridge/memory controller provides a platform-specification-compliant bridge between Power PC microprocessors and the PCI bus. With it, designers can create systems using peripherals already designed for a variety of standard PC interfaces. This bridge chip also integrates a secondary cache controller and high-performance memory controller that supports DRAM or synchronous DRAM and ROM or flash ROM     

2009 CAV award announcement

The 2009 CAV (Computer-Aided Verification) award was presented to seven individuals who made major advances in creating high-performance Boolean satisfiability solvers. This annual award recognizes a specific fundamental contribution or series of outstanding contributions to the CAV field.     

Dust source identification using MODIS: A comparison of techniques applied to the Lake Eyre Basin, Australia

The impact of mineral aerosol (dust) in the Earth's system depends on particle characteristics which are initially determined by the terrestrial sources from which the sediments are entrained. Remote sensing is an established method for the detection and mapping of dust events, and has recently been used to identify dust source locations with varying degrees of success. This paper compares and evaluates five principal methods, using MODIS Level 1B and MODIS Level 2 aerosol data, to: (a) differentiate dust (mineral aerosol) from non-dust, and (2) determine the extent to which they enable the source of the dust to be discerned. The five MODIS L1B methods used here are: (1) un-processed false colour composite (FCC), (2) brightness temperature difference, (3) Ackerman's (1997: J.Geophys. Res., 102, 17069-17080) procedure, (4) Miller's (2003:Geophys. Res. Lett. 30, 20, art.no.2071) dust enhancement algorithm and (5) Roskovensky and Liou's (2005: Geophys. Res. Lett. 32, L12809) dust differentiation algorithm; the aerosol product is MODIS Deep Blue (Hsu et al., 2004: IEEE Trans. Geosci. Rem. Sensing, 42, 557-569), which is optimised for use over bright surfaces (i.e. deserts). These are applied to four significant dust events from the Lake Eyre Basin, Australia. OMI AI was also examined for each event to provide an independent assessment of dust presence and plume location. All of the techniques were successful in detecting dust when compared to FCCs, but the most effective technique for source determination varied from event to event depending on factors such as cloud cover, dust plume mineralogy and surface reflectance. Significantly, to optimise dust detection using the MODIS L1B approaches, the recommended dust/non-dust thresholds had to be considerably adjusted on an event by event basis. MODIS L2 aerosol data retrievals were also found to vary in quality significantly between events; being affected in particular by cloud masking difficulties. In general, we find that OMI AI and MODIS AQUA L1B and L2 data are complementary; the former are ideal for initial dust detection, the latter can be used to both identify plumes and sources at high spatial resolution. Overall, approaches using brightness temperature difference (BT10-11) are the most consistently reliable technique for dust source identification in the Lake Eyre Basin. One reason for this is that this enclosed basin contains multiple dust sources with contrasting geochemical signatures. In this instance, BTD data are not affected significantly by perturbations in dust mineralogy. However, the other algorithms tested (including MODIS Deep Blue) were all influenced by ground surface reflectance or dust mineralogy; making it impossible to use one single MODIS L1B or L2 data type for all events (or even for a single multiple-plume event). There is, however, considerable potential to exploit this anomaly, and to use dust detection algorithms to obtain information about dust mineralogy.