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The aggregation of gel-filtered human platelets induced by A23187 is very sensitive to inhibition by ethanol. Similarly when platelets preloaded with [3H]5-hydroxytryptamine ([3H]5HT) are studied in a superfusion system under conditions where aggregation is likely (high platelet density, presence of Ca2+) the rate of release of [3H]5HT induced by A23187 is reduced by the presence of ethanol. However when platelet aggregation is less likely (low platelet density, absence of Ca2+) ethanol does not reduce the rate of [3H]5HT efflux induced by A23187 in superfused platelets. In addition, in contrast to the effects of ethanol on platelet aggregation, the transformation of human red cells to echinocytes induced by A23187 is accelerated by the presence of ethanol. Similarly the increased efflux of 3H from superfused rat striatal slices preloaded with [3H]dopamine which is produced by A23187 is potentiated by ethanol. It is concluded that the inhibitory effect of ethanol on the action of A23187 may be confined to platelet aggregation. This may be because the mechanisms of action of either A23187 or ethanol on platelet aggregation differ from those on other cell functions.

Inositol monophosphatase can be modified at two sites by pyrene maleimide. These sites have been identified as Cys141 and Cys218. Stoichiometric addition of pyrene maleimide allows the sole modification of Cys218. The fluorescence of the pyrene moiety on the modified protein can be excited directly or by resonance energy transfer. The fluorescence properties of the pyrene group on Cys218 allows the interaction of ligands with the enzyme to be monitored. This feature has allowed dissociation constants for various metal ions to be determined and allowed the formation of various enzyme/ligand complexes to be observed. These studies have demonstrated that Mg2+ is required to support Pi binding and that Li+ interacts with a post‐catalytic complex which is only formed in the forward reaction.

Using two inbred strains of mice which have similar rates of alcohol metabolism, we asked whether prenatal alcohol exposure would cause greater incidence and severity of defects in the development of two forebrain fiber tracts, the corpus callosum and the anterior commissure, in mice prone to these defects (BALB/c) than in mice not prone to these defects (C57BL/6). Pregnant animals were fed 0.6 kcal/g body weight of a Sustacal-based liquid diet containing 0, 15, 17.5, 20, or 25% ethanol-derived calories from day 7 to fetal assessment on day 18 of gestation. Most of alcohol's greatest effects and the greatest strain differences in alcohol's effects on fetal variables were produced by the 17.5% diet. This dose had inhibitory effects on fetal body, brain, and midsagittal corpus callosum and anterior commissure growth. All these effects, except that on brain weight, were significantly greater in C57s than in BALBs. When the results were compared with prenatal growth curves for normal untreated mice, the effect of alcohol on corpus callosum but not anterior commissure growth was largely explained by its effects on overall development. The 17.5% diet had a greater specific effect on size of the anterior commissure in C57s than BALBs but increased the incidence and severity of its permanent dysmorphology in BALBs more than in C57s. Anterior commissure size and morphology may be sensitive indicators of alcohol's effects on prenatal brain development. Hereditary differences in rate of maternal alcohol metabolism no doubt have important consequences for risks arising from prenatal alcohol exposure. However, this study clearly indicates that inherited factors, other than those that influence rate of alcohol metabolism, are important influences on the overall fetal response and the specific responses of the anterior commissure to prenatal alcohol exposure.

The storage and transport of gases in coal is of tremendous importance in the utilisation of coalbeds, and in particular the recovery of methane. There is also increasing interest in the use of coal mines as sites for carbon dioxide sequestration to alleviate the potentially harmful effects of global warming. This paper demonstrates the use of magnetic resonance imaging to investigate the spatiotemporal dynamics of gas transport in coal. The presence of significant structural heterogeneities in the coal was observed. Dynamical effects displayed a broad range of time constants ranging from minutes to days.

Brain-Machine Interfaces (BMIs) have shown great potential for generating prosthetic control signals. Translating BMIs into the clinic requires fully implantable, wireless systems; however, current solutions have high power requirements which limit their usability. Lowering this power consumption typically limits the system to a single neural modality, or signal type, and thus to a relatively small clinical market. Here, we address both of these issues by investigating the use of signal power in a single narrow frequency band as a decoding feature for extracting information from electrocorticographic (ECoG), electromyographic (EMG), and intracortical neural data. We have designed and tested the Multi-modal Implantable Neural Interface (MINI), a wireless recording system which extracts and transmits signal power in a single, configurable frequency band. In prerecorded datasets, we used the MINI to explore low frequency signal features and any resulting tradeoff between power savings and decoding performance losses. When processing intracortical data, the MINI achieved a power consumption 89.7% less than a more typical system designed to extract action potential waveforms. When processing ECoG and EMG data, the MINI achieved similar power reductions of 62.7% and 78.8%. At the same time, using the single signal feature extracted by the MINI, we were able to decode all three modalities with less than a 9% drop in accuracy relative to using high-bandwidth, modality-specific signal features. We believe this system architecture can be used to produce a viable, cost-effective, clinical BMI.

AbstractDevelopmental studies in animals often violate the assumption of statistical independence of observations due to the hierarchical nature of the data (i.e., pups cluster by litter, correlation of individual observations over time). Mixed effect modeling (MEM) provides a robust analytical approach for addressing problems associated with hierarchical data. This article compares the application of MEM to traditional ANOVA models within the context of a developmental study of prenatal ethanol exposure in mice. The results of the MEM analyses supported the ANOVA results in showing that a large proportion of the variability in both behavioral score and brain weight could be explained by ethanol. The MEM also identified that there were significant interactions between ethanol and litter size in relation to behavioral scores and brain weight. In addition, the longitudinal modeling approach using linear MEM allowed us to model for flexible weight gain over time, as well as to provide precise estimates of these effects, which would be difficult in repeated measures ANOVA. © 2007 Wiley Periodicals, Inc. Dev Psychobiol 49: 664–674, 2007.

Phospholipase C (PLC) activity was measured by the incorporation of [3H]-inositol into lipids and by the breakdown of [3H]-inositol-labelled phosphatidylinositols (PI) and polyphosphatidylinositols (PPI) to [3H]-inositol phosphates; phospholipase A2 (PLA2) activity by the breakdown of [3H]oleic acid-labelled phosphatidylcholine [( 3H]PC) to [3H]oleic acid and the enzymes of phospholipid base exchange (PLBE) by the incorporation of [14C]serine into membrane lipids. The activities of these enzymes in rat brain preparations were all increased by procedures which increase intracellular Ca2+, and were all inhibited to a varying extent by the presence of ethanol, 50 mM, in vitro. In contrast, the activities of PLA2 and PLBE enzymes were markedly increased in preparations from animals which had received ethanol chronically in vivo. Similarly, although the basal activity of PLC was only slightly increased in such preparations, depolarization induced the breakdown of a significantly greater fraction of radiolabelled PI than that which was obtained in control preparations. The results suggest compensatory alterations in the activity of Ca2+-activated enzymes of phospholipid metabolism in brain tissue during the continued presence of ethanol in vivo.

The dynamics of granular materials, particularly radial and axial segregation in horizontal rotating cylinders containing large and small particles, is studied by Magnetic Resonance Imaging (MRI). Stationary three-dimensional (3D) images and real-time two-dimensional (2D) structural images showing radial segregation, band formation, and band merging are reported. Quantitative local particle concentrations are measured in a noninvasive manner from the different magnetic resonance responses of the seeds throughout segregation. Data are acquired with sufficiently high temporal (300 ms for 2D images) and spatial resolutions (0.94 mm cubic voxels), to give insights into the underlying mechanisms of both radial and axial segregation. In particular, the increasing rate of the local particle concentration during radial segregation is quantified. Particle migration is observed in the bulk material of the 75% and 82% full cylinders during both radial and axial segregation, showing that this region beneath the avalanche layer does not behave as a solid body. We also provide direct experimental evidence to support recent numerical simulations of band merging.

The accuracy of poly(U) translation was measured in the post-mitochondrial supernatant from whole brain of 7- and 33-month-old Fischer 344 rats. Measurements were made: under in vitro conditions in which translation fidelity was similar to what is known about the accuracy of translation in vivo; and under stresses of varying Mg2+ concentrations (3-12 mM), pH (6.6-8.4), temperature (26-42 degrees C) and in the presence or absence of 2.4% ethanol. No significant difference could be detected between the responses of old and young extracts, the activities of their Phe- and Leu-tRNA synthetases, and their endogenous amounts of Phe-tRNA and Leu-tRNA, despite the fact that the rats studied corresponded in age (by actuarial criteria) to 90-year-old human beings. The accuracy of poly(U) translation was also studied: in liver and hippocampus extracts from 7- and 33-month-old rats; and in brain extracts from 3- and 29-month-old rats. The results were similar to those obtained in brain extracts from 7-month-old rats. Explanations are provided for the inconsistencies which exist in the literature regarding the effect of aging on the accuracy of protein synthesis. It is shown that the inconsistencies are likely to reflect inadequate methodology in three previous studies rather than biological diversity in the control of translation fidelity in aged animals.