Time-resolved measurement of single pulse femtosecond laser-induced periodic surface structure formation

Time-resolved diffraction microscopy technique has been used to observe the formation of laser-induced periodic surface structures (LIPSS) from the interaction of a single femtosecond laser pulse (pump) with a nano-scale groove mechanically formed on a single-crystal Cu substrate. The interaction dynamics (0-1200 ps) was captured by diffracting a time-delayed, frequency-doubled pulse from nascent LIPSS formation induced by the pump with an infinity-conjugate microscopy setup. The LIPSS ripples are observed to form sequentially outward from the groove edge, with the first one forming after 50 ps. A 1-D analytical model of electron heating and surface plasmon polariton (SPP) excitation induced by the interaction of incoming laser pulse with the groove edge qualitatively explains the time-evloution of LIPSS formation.Comment: 4 pages, 5 figure

Automated Grain Yield Behavior Classification

A method for classifying grain stress evolution behaviors using unsupervised learning techniques is presented. The method is applied to analyze grain stress histories measured in-situ using high-energy X-ray diffraction microscopy (HEDM) from the aluminum-lithium alloy Al-Li 2099 at the elastic-plastic transition (yield). The unsupervised learning process automatically classified the grain stress histories into four groups: major softening, no work-hardening or softening, moderate work-hardening, and major work-hardening. The orientation and spatial dependence of these four groups are discussed. In addition, the generality of the classification process to other samples is explored

Accommodating quality and service improvement research within existing ethical principles

Funds were provided by a Canadian Institute of Health Research grant (Nominated PI: Monica Taljaard, PJT – 153045). Funds were also generously provided by Charles Weijer, who is funded by a Tier 1 Canadian Research Chair.Peer reviewedPublisher PD

Single crystals of metal solid solutions

The following definitions were sought in the research on single crystals of metal solid solutions: (1) the influence of convection and/or gravity present during crystallization on the substructure of a metal solid solution; (2) the influence of a magnetic field applied during crystallization on the substructure of a metal solid solution; and (3) requirements for a space flight experiment to verify the results. Growth conditions for the selected silver-zinc alloy system are described, along with pertinent technical and experimental details of the project

Random Walks on a Fluctuating Lattice: A Renormalization Group Approach Applied in One Dimension

We study the problem of a random walk on a lattice in which bonds connecting nearest neighbor sites open and close randomly in time, a situation often encountered in fluctuating media. We present a simple renormalization group technique to solve for the effective diffusive behavior at long times. For one-dimensional lattices we obtain better quantitative agreement with simulation data than earlier effective medium results. Our technique works in principle in any dimension, although the amount of computation required rises with dimensionality of the lattice.Comment: PostScript file including 2 figures, total 15 pages, 8 other figures obtainable by mail from D.L. Stei

Corticosterone Regulates Both Naturally Occurring and Cocaine‐Induced Dopamine Signaling by Selectively Decreasing Dopamine Uptake

Stressful and aversive events promote maladaptive reward‐seeking behaviors such as drug addiction by acting, in part, on the mesolimbic dopamine system. Using animal models, data from our laboratory and others show that stress and cocaine can interact to produce a synergistic effect on reward circuitry. This effect is also observed when the stress hormone corticosterone is administered directly into the nucleus accumbens (NAc), indicating that glucocorticoids act locally in dopamine terminal regions to enhance cocaine\u27s effects on dopamine signaling. However, prior studies in behaving animals have not provided mechanistic insight. Using fast‐scan cyclic voltammetry, we examined the effect of systemic corticosterone on spontaneous dopamine release events (transients) in the NAc core and shell in behaving rats. A physiologically relevant systemic injection of corticosterone (2 mg/kg i.p.) induced an increase in dopamine transient amplitude and duration (both voltammetric measures sensitive to decreases in dopamine clearance), but had no effect on the frequency of transient release events. This effect was compounded by cocaine (2.5 mg/kg i.p.). However, a second experiment indicated that the same injection of corticosterone had no detectable effect on the dopaminergic encoding of a palatable natural reward (saccharin). Taken together, these results suggest that corticosterone interferes with naturally occurring dopamine uptake locally, and this effect is a critical determinant of dopamine concentration specifically in situations in which the dopamine transporter is pharmacologically blocked by cocaine

Substantial stores of sedimentary carbon held in mid-latitude fjords

This work was supported by the Natural Environment Research Council [Grant Number: NE/L501852/1].Quantifying marine sedimentary carbon stocks is key to improving our understanding of longterm storage of carbon in the coastal ocean and to further constraining the global carbon cycle. Here we present a methodological approach which combines seismic geophysics and geochemical measurements to quantitatively estimate the total stock of carbon held within marine sediment. Through the application of this methodology to Loch Sunart a fjord on the west coast of Scotland, we have generated the first full sedimentary carbon inventory for a fjordic system. The sediments of Loch Sunart hold 26.9 ± 0.5 Mt of carbon split between 11.5 ± 0.2 Mt and 15.0 ± 0.4 Mt of organic and inorganic carbon respectively. These new quantitative estimates of carbon stored in coastal sediments are significantly higher than previous estimates. Through an area normalised comparison to adjacent Scottish peatland carbon stocks we have determined that these mid–latitude fjords are significantly more effective as carbon stores than their terrestrial counterparts. This initial work supports the concept that fjords are important environments for the burial and long-term storage of carbon and therefore should be considered and treated as unique environments within the global carbon cycle.Publisher PDFPeer reviewe

Sleep Problems and Gambling Disorder: Cross-Sectional Relationships in a Young Cohort

Aims: To investigate the potential association between gambling disorder and symptoms of sleep problems (including insomnia and excessive daytime sleepiness). It was hypothesised that, compared to controls, individuals with gambling disorder would have significantly greater disturbance of sleep, as indicated by increased scores in: (1) sleep items on the Hamilton Anxiety Rating Scale (HAM-A) and Hamilton Rating Scale for Depression (HAM-D); (2) total score on the HAM-A and HAM-D; and (3) the Epworth Sleepiness Scale (ESS). Methods: Secondary analysis of previously published data from 152 young adults, aged 18-29 years. Individuals were stratified into three groups: controls, those at risk of gambling disorder, and those with gambling disorder. One-way ANOVAs with post-hoc tests were conducted to determine whether groups differed significantly in sleep item scores and total scores of the HAM-A and HAM-D, and the ESS. Results: HAM-D scale insomnia item scores were significantly higher in the disorder group, when compared to controls, this being particularly marked for middle and late insomnia. The HAM-A item score indicated significantly worse sleep quality in the disorder group, compared to at risk and control groups. Total HAM-A and HAM-D scores were significantly higher in the disorder group, but ESS scores did not differ significantly. Conclusion: Measures of disruptions in sleep were significantly higher in gambling disorder than controls. Anxiety and depressive symptom severity was also significantly higher in the gambling disorder group. Further research could have implications for identification and treatment of sleep disorders and psychiatric comorbidities in gambling disorder.</p

The role of health kiosks: a scoping review

Background: Health kiosks are publicly accessible computing devices that provide access to services including health information provision, clinical measurement collection, patient self-check-in, telemonitoring and teleconsultation. While the increase in internet access and ownership of smart personal devices could make kiosks redundant, recent reports have predicted that the market will continue to grow. Objectives: We sought to clarify the current and future roles of health kiosks by investigating: (a) the setting, role, and clinical domains in which kiosks are used; (b) whether usability evaluations of health kiosks are being reported and if so, what methods are being utilized; and (c) what the barriers and facilitators are for the deployment of kiosks. Methods: We conducted a scoping review by a bibliographic search of the Google Scholar, PubMed and Web of Science databases for studies and other publications between January 2009 and June 2020. Eligible papers describe the implementation, either as primary studies, systematic reviews, or news and feature articles. Additional reports were obtained by manual searching and through querying key informants. For each article we abstracted settings, purposes, health domains, whether the kiosk was opportunistic or integrated with a clinical pathway, and inclusion of usability testing. We then summarized the data in frequency tables. Results: A total of 141 articles were included, 134 primary studies and seven reviews. 47% of the primary studies described kiosks in secondary care settings, other settings included community (23.9%), primary care (17.9%), and pharmacies (6.0%). The most common roles of health kiosks were providing health information (35.1%), taking clinical measurements (20.9%), screening (12.7%), telehealth (8.2%), and patient registration (6.0%). The five most frequent health domains were multiple conditions (24.6%), Human Immunodeficiency Virus (HIV) (7.5%), hypertension (7.5%), pediatric injuries (5.2%), health and wellbeing (4.5%) and drug monitoring (4.5%). Kiosks were integrated in the clinical pathway in 70.1%, opportunistic kiosks accounted for 23.9% and 6.0% were being used in both. Usability evaluations of the kiosk were reported in 20.1% of the papers. Barriers (use of expensive proprietary software) and enablers (handling on-demand consultations) to deploying health kiosks were identified. Conclusions: Health kiosks still play a vital role in the healthcare system, including collecting clinical measurements and providing access to online health services and information to those with little or no digital literacy skills, and others without personal internet access. We identified research gaps, such as training needs for teleconsultations, and scant reporting on usability evaluation methods

High-Precision Measurement of the 19Ne Half-Life and Implications for Right-Handed Weak Currents

We report a precise determination of the 19Ne half-life to be $T_{1/2} = 17.262 \pm 0.007$ s. This result disagrees with the most recent precision measurements and is important for placing bounds on predicted right-handed interactions that are absent in the current Standard Model. We are able to identify and disentangle two competing systematic effects that influence the accuracy of such measurements. Our findings prompt a reassessment of results from previous high-precision lifetime measurements that used similar equipment and methods.Comment: 5 pages and 5 figures. Paper accepted for publication in Phys. Rev. Let