Adhesive Joint Evaluation Using Lamb Wave Modes with Appropriate Displacement, Stress, and Energy Distribution Profiles

One of the most elusive yet critical problem in adhesive joints characterization is that of ‘kissing bond’ wherein good contact exists among the adherend and the adhesive, however with no acceptable levels of adhesion. To date, the kissing bond is difficult to be detected reliably by any of the methods including conventional ultrasound and thermal waves. Kissing bond which is a manufacturing defect/anomaly will substantially compromise the load bearing capability of the adhesive joint by initiating adhesive failure (in contrast to cohesive failure wherein the failure occurs within the thickness of the adhesive layer instead of a failure at the interface). Attempts to develop methods of detection of kissing bonds have been unsuccessful to date

Electrophysiological responses to alcohol cues are not associated with Pavlovian-to-instrumental transfer in social drinkers

Published onlineJournal ArticleResearch Support, Non-U.S. Gov'tPavlovian to Instrumental Transfer (PIT) refers to the behavioral phenomenon of increased instrumental responding for a reinforcer when in the presence of Pavlovian conditioned stimuli that were separately paired with that reinforcer. PIT effects may play an important role in substance use disorders, but little is known about the brain mechanisms that underlie these effects in alcohol consumers. We report behavioral and electroencephalographic (EEG) data from a group of social drinkers (n = 31) who performed a PIT task in which they chose between two instrumental responses in pursuit of beer and chocolate reinforcers while their EEG reactivity to beer, chocolate and neutral pictorial cues was recorded. We examined two markers of the motivational salience of the pictures: the P300 and slow wave event-related potentials (ERPs). Results demonstrated a behavioral PIT effect: responding for beer was increased when a beer picture was presented. Analyses of ERP amplitudes demonstrated significantly larger slow potentials evoked by beer cues at various electrode clusters. Contrary to hypotheses, there were no significant correlations between behavioral PIT effects, electrophysiological reactivity to the cues, and individual differences in drinking behaviour. Our findings are the first to demonstrate a PIT effect for beer, accompanied by increased slow potentials in response to beer cues, in social drinkers. The lack of relationship between behavioral and EEG measures, and between these measures and individual differences in drinking behaviour may be attributed to methodological features of the PIT task and to characteristics of our sample.Funded by a research grant from Alcohol Research UK (http://alcoholresearchuk.org/), reference SG 10/11 16

The ad-libitum alcohol 'taste test': secondary analyses of potential confounds and construct validity

RATIONALE: Motivation to drink alcohol can be measured in the laboratory using an ad-libitum 'taste test', in which participants rate the taste of alcoholic drinks whilst their intake is covertly monitored. Little is known about the construct validity of this paradigm. OBJECTIVE: The objective of this study was to investigate variables that may compromise the validity of this paradigm and its construct validity. METHODS: We re-analysed data from 12 studies from our laboratory that incorporated an ad-libitum taste test. We considered time of day and participants' awareness of the purpose of the taste test as potential confounding variables. We examined whether gender, typical alcohol consumption, subjective craving, scores on the Alcohol Use Disorders Identification Test and perceived pleasantness of the drinks predicted ad-libitum consumption (construct validity). RESULTS: We included 762 participants (462 female). Participant awareness and time of day were not related to ad-libitum alcohol consumption. Males drank significantly more alcohol than females (

Currency Unions

A currency union is when several independent sovereign nations share a common currency. This has been a recurring phenomenon in monetary history. In this article I study the theoretical foundations of such unions, and discuss some important currency unions in history, most notably the case of the US. Finally I contrast the design of the EMU with economic theories and historical experiences of currency unions

Metal–silicate partitioning of W and Mo and the role of carbon in controlling their abundances in the bulk silicate earth

The liquid metal–liquid silicate partitioning of molybdenum and tungsten during core formation must be well-constrained in order to understand the evolution of Earth and other planetary bodies, in particular because the Hf–W isotopic system is used to date early planetary evolution. The partition coefficients DMo and DW have been suggested to depend on pressure, temperature, silicate and metal compositions, although previous studies have produced varying and inconsistent models. Additionally, the high cationic charges of W and Mo in silicate melts make their partition coefficients particularly sensitive to oxygen fugacity. We combine 48 new high pressure and temperature experimental results with a comprehensive database of previous experiments to re-examine the systematics of Mo and W partitioning, and produce revised partitioning models from the large combined dataset. W partitioning is particularly sensitive to silicate and metallic melt compositions and becomes more siderophile with increasing temperature. We show that W has a 6+ oxidation state in silicate melts over the full experimental fO2 range of ΔIW −1.5 to −3.5. Mo has a 4+ oxidation state, and its partitioning is less sensitive to silicate melt composition but also depends on metallic melt composition. DMo stays approximately constant with increasing depth in Earth. Both W and Mo become more siderophile with increasing C content of the metal: we therefore performed experiments with varying C concentrations and fit epsilon interaction parameters:  = −7.03 ± 0.30 and  = −7.38 ± 0.57. W and Mo along with C are incorporated into a combined N-body accretion and core–mantle differentiation model, which already includes the major rock-forming elements as well as S, and moderately and highly siderophile elements. In this model, oxidation and volatility gradients extend through the protoplanetary disk so that Earth accretes heterogeneously. These gradients, as well as the metal–silicate equilibration pressure, are fitted using a least squares optimisation so that the model Earth-like planet reproduces the composition of the bulk silicate Earth (BSE) in terms of 17 simulated element concentrations (Mg, Fe, Si, Ni, Co, Nb, Ta, V, Cr, S, Pt, Pd, Ru, Ir, W, Mo, and C). The effects of the interaction of W and Mo with Si, S, O, and C in metal are included. Using this model with six separate terrestrial planet accretion simulations, we show that W and Mo require the early accreting Earth to be sulfur-depleted and carbon-enriched so that W and Mo are efficiently partitioned into Earth’s core and do not accumulate in the mantle. When this is the case, the produced Earth-like planets possess mantle compositions matching the BSE for all simulated elements. However, there are two distinct groups of estimates of the bulk mantle’s C abundance in the literature: low (∼100 ppm) and high (∼800 ppm), and all six models are consistent with the higher estimated carbon abundance. The low BSE C abundance would be achievable when the effects of the segregation of dispersed metal droplets produced in deep magma oceans by the disproportionation of Fe2+ to Fe3+ plus metallic Fe is included

Synchronized dynamics of cortical neurons with time-delay feedback

The dynamics of three mutually coupled cortical neurons with time delays in the coupling are explored numerically and analytically. The neurons are coupled in a line, with the middle neuron sending a somewhat stronger projection to the outer neurons than the feedback it receives, to model for instance the relay of a signal from primary to higher cortical areas. For a given coupling architecture, the delays introduce correlations in the time series at the time-scale of the delay. It was found that the middle neuron leads the outer ones by the delay time, while the outer neurons are synchronized with zero lag times. Synchronization is found to be highly dependent on the synaptic time constant, with faster synapses increasing both the degree of synchronization and the firing rate. Analysis shows that presynaptic input during the interspike interval stabilizes the synchronous state, even for arbitrarily weak coupling, and independent of the initial phase. The finding may be of significance to synchronization of large groups of cells in the cortex that are spatially distanced from each other.Comment: 21 pages, 11 figure

Identifying the motives for and against drinking during pregnancy and motherhood, and factors associated with increased maternal alcohol use

Aim: Maternal drinking (alcohol use during pregnancy/motherhood) is a hidden public health concern which can have significant negative effects on the woman and child. This pilot survey explored several domains that might influence maternal drinking. Subject and methods: Two cross-sectional, online surveys recruited (1) women who were pregnant and (2) mothers who were not pregnant. Surveys captured data on alcohol use and harmful drinking, attitudes on and motives for drinking/not drinking, and perceived barriers to drinking less. Content analysis of free text responses complemented quantitative data. Results: In this convenience sample of 836 pregnant women and 589 mothers, 91% of pregnant women and 28% of mothers reported abstinence. Of those reporting alcohol use, median consumption was 2.3 units/week in pregnant women, and 6.9 units/week in non-pregnant mothers. Of mothers currently drinking, 25.1% reported hazardous or harmful levels. Heavier drinking was associated with numerous motives, including using alcohol as a coping strategy. Child welfare was a key motivating factor for not drinking, as were practical issues of motherhood. The stresses of motherhood were a perceived barrier to reducing drinking, and mothers reported more barriers than pregnant women. Conclusion: Stress reduction motives may be a risk factor for heavier maternal drinking, while motives for not drinking seem to be focused on child welfare and maternal well-being. Stress and a lack of knowledge about how to reduce drinking appear to be barriers for mothers to change their drinking behaviour. These findings can inform the development of effective public health interventions to reduce maternal drinking

The effects of menstrual cycle stage and hormonal contraception on alcohol consumption and craving: A pilot investigation

Background and aims: Although alcohol research often comments on observed sex differences (i.e. patterns of consumption), there is a lack of investigation into the reasons for these differences. For females, the regular hormonal fluctuations across the menstrual cycle are a potential influencing factor for alcohol consumption. In this pilot we aimed to investigate the relationship between menstrual cycle phase (follicular-phase [FP] and luteal-phase [LP]) and status (naturally-cycling [NC] and hormonal-contraception [HC]) on alcohol consumption and craving of casual drinkers, and identify potential influencing factors in this relationship. Methods: Study One: participants (n ​= ​28; 15 HC, 13 NC) were either NC or HC (between subject factor: hormonal status) and attended two lab-based sessions corresponding with their FP and LP (within factor: cycle phase [NC] or time [HC]). Participants completed a mock alcohol taste-test, in addition to pre- and post-consumption measures of craving, anxiety, stress, and mood. Study Two: participants (n ​= ​262; 144 HC, 118 NC) were either NC or HC (between subject factor) and completed an online study assessing menstrual cycle phase, alcohol use, craving, impulsivity, and stress. Results: Study One: A significant effect of cycle phase was found on alcohol craving (p ​= ​.019): craving was higher during the FP compared to the LP for NC participants, with HC participants showing no difference across sessions. There was no effect of phase or status on alcohol consumption, stress, or mood (ps ​> ​.05). Study Two: Regression analyses showed that age, craving, impulsivity and stress were significantly associated with alcohol consumption for NC participants (ps ​< ​.05), however only age and craving were associated with consumption for the HC participants (ps ​< ​.001). Conclusions: Alcohol craving was higher during the follicular, compared to the luteal, phase for the naturally cycling group, and different factors may be associated with drinking behaviour across women who are NC and those using HC. Future alcohol research should consider the menstrual cycle and contraceptive status for females

Alcohol use during pregnancy and motherhood: Attitudes and experiences of pregnant women, mothers, and healthcare professionals

Alcohol is the most used substance by women of childbearing age. Alcohol exposed pregnancies can have serious consequences to the fetus, and the UK has one of the highest rates of drinking during pregnancy. Alcohol use during motherhood is also a public health concern, linked with potential harms to the woman and child. This qualitative study investigated the attitudes and experiences of pregnant/parenting women and healthcare professionals regarding maternal drinking. A semi-structured focus group and interviews were conducted in the North West of England with pregnant women, mothers, and healthcare professionals. Quantitative measures captured demographics, alcohol use, and screened for mental ill-health for pregnant women and mothers. Reflexive thematic analysis was used to analyse narratives. Findings revealed that most participants believed avoiding alcohol during pregnancy is the safest option. However, some pregnant women and mothers stated that there was insufficient evidence to demonstrate the harms of low-level drinking and that abstinence guidelines were patronising. All participants reported that low-level drinking during motherhood was acceptable. Heavy drinking was believed to pose serious harm during pregnancy and motherhood to the baby and mother, in addition to damaging relationships. Strong motives were revealed for choosing and avoiding to drink, such as coping with the difficulties of motherhood and parental responsibilities, respectively. Contradictions were found across quantitative and qualitative self-reports of consumption, reflecting potential underreporting of alcohol use. Additionally, drinking levels were discussed in extremes only (low/heavy) without considering ‘grey area’ drinking. Clear, consistent advice and guidelines are needed to support women in reducing their alcohol use during pregnancy and motherhood. These should include the unique potential risks regarding maternal drinking, and the harm attributable to non-clinically dependent alcohol use. The maternal participants in this study were middle-class, therefore, research is needed to capture the views and experiences of women of all socioeconomic backgrounds