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The Wisconsin Twin Project comprises multiple longitudinal studies that span infancy to early adulthood. We summarize recent papers that show how twin designs with deep phenotyping, including biological measures, can inform questions about phenotypic structure, etiology, comorbidity, heterogeneity, and gene–environment interplay of temperamental constructs and mental and physical health conditions of children and adolescents. The general framework for investigations begins with rich characterization of early temperament and follows with study of experiences and exposures across childhood and adolescence. Many studies incorporate neuroimaging and hormone assays.
In the southern Gulf of Mexico, the spotted eagle ray (Aetobatus narinari) is the second most frequently caught batoid in small-scale fisheries off Campeche. Ecological aspects of this ray are unknown in this region, hampering the understanding of the relationship between its distribution and prey availability in the fishing area. In order to study the feeding habits of this batoid and characterize its potential prey in the study area, stomachs and intestines of 154 specimens (68 females and 86 males) were analysed. The results indicated that A. narinari near Campeche is a specialist and selective predator that feeds mainly on gastropods (92.7% IRI), with no significant differences in the diet found between sexes, size groups, or between stomach and intestine contents. In addition, the results indicated that the most important prey species in the diet were among the most common benthic species in three of the four sampling transects positioned in or adjacent to fishing areas for rays. These most important prey species were Strombus pugilis (53.33% IRI) and Americoliva reticularis (25.6% IRI). Other prey species included Lobatus costatus (5.6% IRI) and Petrochirus diogenes (3.6% IRI). This study suggests that this widely distributed ray species feeds in Campeche's coastal waters and that the study of its potential prey increases the understanding of ecological aspects of the species, which emphasizes the added importance of monitoring fishery impacts on prey species (e.g. the conch fishery off Campeche) to help support integrated assessment and management of fisheries.
Introduction: Patients with chronic diseases are known to benefit from exercise. Such patients often visit the emergency department (ED). There are few studies examining prescribing exercise in the ED. We wished to study if exercise prescription in the ED is feasible and effective. Methods: In this pilot prospective block randomized trial, patients in the control group received routine care, whereas the intervention group received a combined written and verbal prescription for moderate exercise (150 minutes/week). Both groups were followed up by phone at 2 months. The primary outcome was achieving 150 min of exercise per week. Secondary outcomes included change in exercise, and differences in reported median weekly exercise. Comparisons were made by Mann-Whitney and Fishers tests (GraphPad). Results: Follow-up was completed for 22 patients (11 Control; 11 Intervention). Baseline reported median (with IQR) weekly exercise was similar between groups; Control 0(0-0)min; Intervention 0(0-45)min. There was no difference between groups for the primary outcome of 150 min/week at 2 months (Control 3/11; Intervention 4/11, RR 1.33 (95%CI 0.38-4.6;p=1.0). There was a significant increase in median exercise from baseline in both groups, but no difference between the groups (Control 75(10-225)min; Intervention 120(52.5-150)min;NS). 3 control patients actually received exercise prescription as part of routine care. A post-hoc comparison of patients receiving intervention vs. no intervention, revealed an increase in patients meeting the primary target of 150min/week (No intervention 0/8; Intervention 7/14, RR 2.0 (95%CI 1.2-3.4);p=0.023). Conclusion: Recruitment was feasible, however our study was underpowered to quantify an estimated effect size. As a significant proportion of the control group received the intervention (as part of standard care), any potential measurable effect was diluted. The improvement seen in patients receiving intervention and the increase in reported exercise in both groups (possible Hawthorne effect) suggests that exercise prescription for ED patients may be beneficial.
Introduction: The positive health outcomes of exercise have been well-studied, and exercise prescription has been shown to reduce morbidity in several chronic health conditions. However, patient attitudes around the prescription of exercise in the emergency department (ED) have not been explored. The aim of our pilot study is to explore patients’ willingness and perceptions of exercise being discussed and prescribed in the ED. Methods: This study is a survey of patients who had been previously selected for exercise prescription in a pilot study conducted at a tertiary care ED. This intervention group were given a standardized provincial written prescription to perform moderate exercise for 150 minutes per week. Participants answered a discharge questionnaire and were followed up by a telephone interview 2 months later. A structured interview of opinions around exercise prescription was conducted. Questions included a combination of non-closed style interview questions and Likert scale. Patients rated prescription detail, helpfulness and likelihood on a Likert scale from 1-5 (1 being strongly disagree and 5 being strongly agree). Median values (+/-IQRs) are presented, along with dominant themes. Results: 17 people consented to exercise prescription and follow up surveys. 2 were excluded due to hospital admission. 15 participants were enrolled and completed the discharge survey. Two-month follow up survey response rate was 80%. Patients rated the detail given in their prescription as 5 (+/-1). Helpfulness of prescription was rated as 4 (+/-2). Likelihood to continue exercising based on the prescription was rated as 4 (+/-2). 11/12 participants felt that exercise should be discussed in the Emergency Department either routinely or on a case-by-case basis.1 participant felt it should not be discussed at all. Conclusion: Our study demonstrates that most patients are open to exercise being discussed during their Emergency Department visit, and that the prescription format was well-received by study participants.
Current robotic systems have achieved great sophistication in kinematic motion, control, and neural processing. One of the most challenging limitations imposed on modern robotics is the portable power source needed to sustain tether-free operation. Energy storage devices such as batteries and combustion engines may be heavy, require a great deal of space, and invariably have a finite energy capacity. Methods to control such devices may also impose limitations as most robotic systems rely on either tethered or radiative communication. The unavoidable repercussion of these limitations is the ultimate reduction of mobility and operation time to achieve specific tasks. To address these challenges, we apply our quasi-wireless powering methodology to show the operation of two robotic devices over a 1×1 m2 surface. Both power and control signals are transmitted simultaneously, producing seamless storage-free functionality over the entire area with a communication technique that is not line-of-sight or radiation dependent. We demonstrate an average power transfer efficiency of 93% using commercially available toy robots and discuss parameters relating to the power and communication performance.
There is growing concern about an alleged rise in violent behaviour amongst military personnel returning from deployment to Iraq and Afghanistan. The aims of this study were to determine the prevalence of violence in a sample of UK military personnel following homecoming from deployment in Iraq and to examine the impact of deployment-related experiences, such as combat trauma, on violence, and the role of sociodemographics and pre-enlistment antisocial behaviour.
This study used baseline data from a cohort study of a large randomly selected sample of UK Armed Forces personnel in service at the time of the Iraq war (2003). Regular personnel (n=4928) who had been deployed to Iraq were included. Data, collected by questionnaire, included information on deployment experiences, sociodemographic and military characteristics, pre-enlistment antisocial behaviour, post-deployment health outcomes and a self-report measure of physical violence in the weeks following return from deployment.
Prevalence of violence was 12.6%. This was strongly associated with pre-enlistment antisocial behaviour [adjusted odds ratio (aOR) 3.6, 95% confidence interval (CI) 2.9–4.4]. After controlling for pre-enlistment antisocial behaviour, sociodemographics and military factors, violence was still strongly associated with holding a combat role (aOR 2.0, 95% CI 1.6–2.5) and having experienced multiple traumatic events on deployment (aOR for four or more traumatic events 3.7, 95% CI 2.5–5.5). Violence on homecoming was also associated with mental health problems such as post-traumatic stress disorder (aOR 4.8, 95% CI 3.2–7.2) and alcohol misuse (aOR 3.1, 95% CI 2.5–3.9).
Experiences of combat and trauma during deployment were significantly associated with violent behaviour following homecoming in UK military personnel. Post-deployment mental health problems and alcohol misuse are also associated with increased violence.
The third Lecturer to the Faculty of Actuaries is Mr Karel Van Hulle. He is a lawyer by training, and is Head of Unit at the European Commission (Directorate-General ‘Internal Market and Services’), which he joined in 1984, after having served for eight years with the Belgian Banking Commission.
He was subsequently Head of Unit for Accounting Standards, Head of Unit for Financial Reporting and Company Law and Head of Unit for Accounting and Auditing. In that capacity he was closely involved with harmonisation in the fields of accounting, auditing and company law, both at European Union level and internationally, and served as the Commission's observer with the International Accounting Standards Committee. He was Secretary of the High Level Group of Experts on Company Law, which prepared the Commission's 2003 Action Plan on Company Law.
Since November 2004 he has been Head of the Insurance and Pensions Unit. In this function, his main responsibility is the preparation of the new solvency regime for insurance and reinsurance companies (Solvency II).
Previous studies have documented that smoking during pregnancy (SDP) is associated with offspring externalizing problems, even when measured covariates were used to control for possible confounds. However, the association may be because of nonmeasured environmental and genetic factors that increase risk for offspring externalizing problems. The current project used the National Longitudinal Survey of Youth and their children, ages 4–10 years, to explore the relations between SDP and offspring conduct problems (CPs), oppositional defiant problems (ODPs), and attention-deficit/hyperactivity problems (ADHPs) using methodological and statistical controls for confounds. When offspring were compared to their own siblings who differed in their exposure to prenatal nicotine, there was no effect of SDP on offspring CP and ODP. This suggests that SDP does not have a causal effect on offspring CP and ODP. There was a small association between SDP and ADHP, consistent with a causal effect of SDP, but the magnitude of the association was greatly reduced by methodological and statistical controls. Genetically informed analyses suggest that unmeasured environmental variables influencing both SDP and offspring externalizing behaviors account for the previously observed associations. That is, the current analyses imply that important unidentified environmental factors account for the association between SDP and offspring externalizing problems, not teratogenic effects of SDP.
The growth of thick silicon carbide (SiC) epitaxial layers for large-area, high-power devices is described. Horizontal hot-wall epitaxial reactors with a capacity of three, 3-inch wafers have been employed to grow over 350 epitaxial layers greater than 100 μm thick. Using this style reactor, very good doping and thickness uniformity and run-to-run reproducibility have been demonstrated. Through a combination of reactor design and process optimization we have been able to achieve the routine production of thick epitaxial layers with morphological defect densities of around 1 cm−2. The low defect density epitaxial layers in synergy with improved substrates and SiC device processing have resulted in the production of 10 A, 10 kV junction barrier Schottky (JBS) diodes with good yield (61.3%).
The construction of interaction potentials for the Y0.5+0.25xNb0.25xZr0.5–0.5xO1.75 system, on a purely ab-initio basis, is described. These potentials accurately reproduce experimental data on both the structure and the dynamics of these systems; the computer simulations also reproduce the experimental trend of the conductivity, which decreases as x increases, and of the level of static disorder within the O2− sublattice, which increases with x. A detailed analysis of these phenomena shows that the static disorder in Y3NbO7 is caused by the high Nb5+ charge and that in this material the conduction is heterogeneous, i.e. some anions are completely immobile while some others are very mobile. The role of the cation sublattice is explained in detail.
The aim was to determine the prevalence of chronic fatigue syndrome (CFS), chronic fatigue and fibromyalgia in UK military personnel after the Gulf War 1990–1991.
A two-phase cohort study was used. Three randomly selected subsamples identified from a population-based cross-sectional postal survey of over 10 000 current and ex-service UK military personnel (Gulf veterans were those deployed to the Gulf War 1990–1991; non-Gulf veterans were Bosnia peacekeepers 1992–1997 and those on active duty during the Gulf War 1990–1991 but not deployed) were recruited. Their disability status was assessed using the Short Form 36 physical functioning scale; Gulf veterans who reported physical disability (n=111) were compared with non-Gulf (n=133) veterans who reported similar levels of physical disability. Screening for known medical and psychiatric conditions was conducted to exclude medical explanations for disability and symptomatic distress. Standardised criteria for CFS, chronic fatigue and fibromyalgia were used.
Disabled Gulf veterans were more likely to be overweight, have elevated γ-glutamyl transferase levels and screen positive for hypertension. There were no other clinically significant differences in clinical markers for medically explainable conditions. Disabled Gulf veterans were more likely than similarly disabled Bosnia and Era veterans (adjusted odds ratio 7.8, 95% confidence interval 2.5–24.5) to meet the criteria for CFS. Rates for other medically unexplained conditions were not significantly increased.
Symptoms in keeping with CFS account for a significant part of the symptomatic distress in Gulf veterans.
Isothermal sections in the Ni–Al–Ga–N quaternary phase diagram were calculated to provide a greater understanding of interfacial reactions between Ni contacts and AlxGa1−xN. The calculations were performed employing a thermodynamic database of the Ni–Al–Ga–N system that was constructed by combining the six binary systems of the four component system. The model of the Ga–N binary system was created in this work. The models of the Ni–Ga and Ni–Al systems, both of which were taken from the literature, were modified to be compatible with one another. Thermodynamic data and phase boundaries for other binary systems were taken from the literature, as was information on portions of the Al–Ga–N and Ni–Al–Ga phase diagrams. The calculated sections reveal that during reaction between Ni and AlxGa1−xN, Ni is favored to react with the GaN component of the semiconductor alloy, leaving an Al-enriched AlxGa1−xN. These predictions are consistent with a recent analysis of the Ni, Al, and Ga elemental distributions across the interface between a Ni thin film and an Al0.47Ga0.53N epitaxial layer following annealing at 850 °C. Consideration of the thermodynamic driving forces suggests that this may be a general phenomenon existing in other metal–Al–Ga–N systems.
Wartime traumatic events are related to subsequent psychological and physical health, but quantifying the association is problematic. Memory changes over time and is influenced by psychological status.
To use a large, two-stage cohort study of members of the UK armed forces to study changes in recall of both traumatic and ‘toxic’ hazards.
A questionnaire-based follow-up study assessed 2370 UK military personnel, repeating earlier questions about exposure to military hazards.
The κ statistics for reporting of hazards were good for some exposures, but very low for others. Gulf veterans reported more exposures over time (no significant rise in the Bosnia cohort). In the Gulf cohort only, reporting new exposures was associated with worsening health perception, and forgetting previously reported exposures with improved perception. We found no association between physical health, psychological morbidity or post-traumatic stress disorder symptoms and endorsement or non-endorsement of exposures.
Reporting of military hazards after a conflict is not static, and is associated with current self-rated perception of health. Self-report of exposures associated with media publicity needs to be treated with caution.
Background. Peace-keeping duties are associated with unique stresses for military personnel. There have been few reports on the effects of peace-keeping on psychological health.
Method. We used data from a cross-sectional study originally established to examine health effects of service in the Gulf War, which included a control group who had been deployed in Bosnia (N=2049). This group was examined to establish which demographic, occupational, and deployment-related risk factors were associated with psychological distress measured on the General Health Questionnaire (GHQ-12) and stress symptoms akin to a post-traumatic stress reactions.
Results. The main risk factors for stress symptoms in the Bosnia group were – lower rank, being deployed early in the campaign, having more deployment-related exposures, and serving on staff duties. There was no protective effect of previous deployments to the Falklands or Northern Ireland, and time off following deployment was not protective. For GHQ-12 cases, the main risk factors were: female gender, lower rank, increased deployment-related exposures and serving on staff duties.
Conclusions. This study suggests that stress symptoms and GHQ-12 cases, are strongly predicted both by experiences during deployment and demographic factors.
In situ transmission electron microscopy is an established experimental technique that permits direct observation of the dynamics and mechanisms of dislocation motion and deformation behavior. In this article, we detail the development of a novel specimen goniometer that allows real-time observations of the mechanical response of materials to indentation loads. The technology of the scanning tunneling microscope is adopted to allow nanometer-scale positioning of a sharp, conductive diamond tip onto the edge of an electron-transparent sample. This allows application of loads to nanometer-scale material volumes coupled with simultaneous imaging of the material’s response. The emphasis in this report is qualitative and technique oriented, with particular attention given to sample geometry and other technical requirements. Examples of the deformation of aluminum and titanium carbide as well as the fracture of silicon will be presented.
The initial growth of InAs on 11% lattice mismatched GaP substrates by molecular beam epitaxy was investigated. High resolution transmission electron microscopy (HREM) images showed that the InAs grew in the form of three-dimensional islands of dissimilar sizes. Mismatch induced strain relief was effected by the direct introduction of (mostly) edge dislocations at the corners of the islands. An examination of HREM images of several islands revealed that the island aspect ratio decreased with the introduction of misfit dislocations. Strain relaxation in the smaller, relatively dislocation-free islands occurred by elastic deformation of InAs lattice planes, which was more effective far from the constrained island-substrate interface. As a result, these islands grew taller and narrower, with a gradient in the elastic strain energy. However, a higher aspect ratio resulted in a higher surface area – to – volume ratio, and increased the surface energy of the InAs islands. Consequently, there was a driving force for the reduction of the aspect ratio if an alternate avenue for strain relaxation existed. The alternate route was plastic deformation by the introduction of misfit dislocations. As the island grew, the strain at the island corners increased, and beyond a critical value, misfit dislocations were added. These dislocations relieved strain at the heterointerface, and promoted the islands to grow laterally, i.e., the aspect ratio decreased. Islands coalesced, and a continuous layer resulted by a nominal thickness of 3 nm. Thus, the morphology of InAs islands grown on GaP was determined by the balance between elastic and plastic deformation.
An overview is given of the quantum-dot cellular automata (QCA) architecture, along with a summary of experimental demonstrations of QCA devices. QCA is a transistorless computation paradigm that can provide a solution to such challenging issues as device and power density. The basic building blocks of the QCA architecture, such as AND, OR gates and clocked cells have been demonstrated and will be presented here. The quantum dots used in the experiments to date are metal islands that are coupled by capacitors and tunnel junctions, and devices operate only at very low temperatures. For QCA to be used in practical devices, the operating temperature must be raised, and issues such as background charge must be addressed. An introduction will be given to these issues and possible solutions.