297 research outputs found
Identification of structural controls in an active lava dome with high resolution DEMs:Volcán de Colima, Mexico
Monitoring the topography of active lava domes is critical for detecting changes that may trigger or influence collapse or explosive activity. Internal dome structure and conditions are more difficult to elucidate, but also play vital roles. Here, we describe the exposure (following an explosion) of significant scarps in the active dome at Volcán de Colima, Mexico, that are interpreted as evidence of brittle failure planes and a complex internal dome morphology. In the first use of automated 3D computer vision reconstruction techniques (structure-from-motion and multi-view stereo, SfM-MVS) on an active volcanic dome, we derive high resolution surface models from oblique and archive photographs taken with a consumer camera. The resulting 3D models were geo-referenced using features identified in a web-sourced orthoimage; no ground-based measurements were required. In December 2010, the dome (2.14×106 m3) had a flat upper surface, reflecting an overall ductile emplacement regime. Between then and May 2011, a period of low explosivity was accompanied by a small volume loss (0.4×105 m3) and arcuate steps appeared in the dome surface, suggesting the presence of localized planes of weakness. The complex array of summit scarps was exposed following a significant explosion in June 2011, and is interpreted to be the surface expression of fault planes in the dome. The 1-m resolution DEMs indicated that the region of greatest volume loss was not coincident with the assumed location of the conduit, and that heterogeneity within the dome may have been important during the June explosion
Supersolidity and superfluidity in two dimensions
This thesis attempts to investigate the phenomenon of supersolidity, where a system exhibits both spontaneously broken translational and U(1) symmetries, in two different two dimensional systems, one fermionic and one bosonic. The fermionic system consists of two parallel GaAs quantum wells that are independently gated. This allows the electron and hole populations of the two layers to be independently varied. Using mean field theory, it will be shown that the zero temperature phase diagram of this system contains a Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) phase, analogous to that predicted to occur in superconductors. This phase has spontaneously broken U(1) and translational symmetries, and can therefore be thought of as a supersolid. This mean field analysis will be complemented by a Ginzburg-Landau approach, which will be used to confirm the results and to calculate the lattice structure of the FFLO order parameter. The bosonic system consists of a thin helium-4 film deposited on graphite. Recent experiments on this system have produced results that suggest the presence of a supersolid phase over a range of helium filling fractions, as well as the lack of a Kosterlitz-Thouless phase transition at
finite temperature. An attempt to explain these results is made by applying mean field and Bogoliubov theories to a toy model at zero temperature.Open Acces
Findings from the University of East Anglia's evaluation of the Ipswich/Suffolk multi-agency strategy on prostitution following the five murders in 2006
This paper provides a summary of the main findings of an evaluation of a new multi-agency Strategy set up to tackle on-street sex-working, after five prostitutes were murdered in the English county town of Ipswich. It focuses on the outcomes of the Strategy’s four objectives, including their cost-effectiveness. It also offers an insight into the lives of the women who were previously involved in street sex-working, the means by which the Strategy helped them to move towards exiting this work, and the ways in which younger people identified as being at risk of entering it might be prevented from doing so
Severely restricting energy intake for 24 h does not affect markers of bone metabolism at rest or in response to re-feeding
Purpose:
Intermittent energy restriction commonly refers to ad libitum energy intake punctuated with 24 h periods of severe energy restriction. This can improve markers of metabolic health but the effects on bone metabolism are unknown. This study assessed how 24 h severe energy restriction and subsequent refeeding affected markers of bone turnover.
Methods:
In a randomised order, 16 lean men and women completed 2, 48 h trials over 3 days. On day 1, participants consumed a 24 h diet providing 100% [EB: 9.27 (1.43) MJ] or 25% [ER: 2.33 (0.34) MJ] of estimated energy requirements. On day 2, participants consumed a standardised breakfast (08:00), followed by an ad libitum lunch (12:00) and dinner (19:30). Participants then fasted overnight, returning on day 3. Plasma concentrations of C-terminal telopeptide of type I collagen (CTX), procollagen type 1 N-terminal propeptide (P1NP) and parathyroid hormone (PTH) were assessed as indices of bone metabolism after an overnight fast on days 1–3, and for 4 h after breakfast on day 2.
Results:
There were no differences between trials in fasting concentrations of CTX, P1NP or PTH on days 1–3 (P [greater than] 0.512). During both trials, consuming breakfast reduced CTX between 1 and 4 h (P [less than] 0.001) and PTH between 1 and 2 h (P [less than] 0.05), but did not affect P1NP (P = 0.773) Postprandial responses for CTX (P = 0.157), P1NP (P = 0.148) and PTH (P = 0.575) were not different between trials. Ad libitum energy intake on day 2 was greater on ER [12.62 (2.46) MJ] than EB [11.91 (2.49) MJ].
Conclusions
Twenty-four hour severe energy restriction does not affect markers of bone metabolism
Bioinspired Hard–Soft Interface Management for Superior Performance in Carbon Fibre Composites
Nature has evolved to create materials of unmatched performance governed by the interfacial interactions between hard and soft surfaces. Typically, in a carbon fibre composite, one polymer and one type of carbon fibre is used throughout a laminate. In this work, we use a carbon fibre surface modification approach to vary the fibre–matrix interface throughout the laminate to tailor the soft–hard interfaces. We demonstrate this effect using reclaimed carbon fibre materials in a thermoset polymer, then extend this concept to a thermoplastic polymer matrix–polypropylene. The thermoset specimens examined in this work consist of 5 carbon fibre plies, featuring 0, 1, 3 or 5 surface-modified layers located at the centre of the composite. The largest improvements in physical properties for these composites (yield strength, ultimate flexural strength, and tensile modulus) were found when only 1 modified layer of carbon fibre was placed directly within the centre of the composite. Subsequent investigations revealed that for a polypropylene matrix, where the surface chemistry is tailored specifically for polypropylene, improvements are also observed when mixed surface chemistries are used. This work shows that surface modification of reclaimed carbon fibres as non-woven mats can provide significant improvements in mechanical properties performance for structural composites when used in strategically advantageous locations throughout the composite
Effect of carbohydrate feeding on the bone metabolic response to running
Bone resorption is increased after running, with no change in bone formation. Feeding during exercise might attenuate this increase, preventing associated problems for bone. This study investigated the immediate and short-term bone metabolic responses to carbohydrate (CHO) feeding during treadmill running. Ten men completed two 7-day trials, once being fed CHO (8% glucose immediately before, every 20 min during, and immediately after exercise at a rate of 0.7 g CHO·kg body mass-1·h-1) and once being fed placebo (PBO). On day 4 of each trial, participants completed a 120-min treadmill run at 70% of maximal oxygen consumption (VO2 max). Blood was taken at baseline (BASE), immediately after exercise (EE), after 60 (R1) and 120 (R2) min of recovery, and on three follow-up days (FU1-FU3). Markers of bone resorption [COOH-terminal telopeptide region of collagen type 1 (β-CTX)] and formation [NH2-terminal propeptides of procollagen type 1 (P1NP)] were measured, along with osteocalcin (OC), parathyroid hormone (PTH), albumin-adjusted calcium (ACa), phosphate, glucagon-like peptide-2 (GLP-2), interleukin-6 (IL-6), insulin, cortisol, leptin, and osteoprotogerin (OPG). Area under the curve was calculated in terms of the immediate (BASE, EE, R1, and R2) and short-term (BASE, FU1, FU2, and FU3) responses to exercise. β-CTX, P1NP, and IL-6 responses to exercise were significantly lower in the immediate postexercise period with CHO feeding compared with PBO (β-CTX: P=0.028; P1NP: P=0.021; IL-6: P=0.036), although there was no difference in the short-term response (β-CTX: P=0.856; P1NP: P=0.721; IL-6: P=0.327). No other variable was significantly affected by CHO feeding during exercise. We conclude that CHO feeding during exercise attenuated the β-CTX and P1NP responses in the hours but not days following exercise, indicating an acute effect of CHO feeding on bone turnover
Highly consistent genetic alterations in childhood adrenocortical tumours detected by comparative genomic hybridization
We have examined 11 cases of childhood adrenocortical tumours for copy number changes using comparative genomic hybridization (CGH). The changes seen are highly consistent between cases, and are independent of tumour type (carcinoma versus adenoma) or the presence of a germline TP53 mutation. The regions of chromosomal gain and loss identified in this study indicate the location of genes that are potentially important in the development and progression of childhood adrenocortical tumours. Finally, the copy number changes identified in childhood tumours are distinctly different to those seen in adult cases (Kjellman et al (1996) Cancer Res56: 4219–4223), and we propose that this indicates that childhood tumours are of embryonal origin. © 1999 Cancer Research Campaig
Attachment and propensity for reporting compassionate opportunities and behavior in everyday life
IntroductionResearchers have identified links between anxious and avoidant attachments and difficulties with self-compassion, giving others compassion, and receiving compassion. However, while compassion requires both awareness of opportunities for compassion and compassionate action, little is known about attachment-related differences in reporting compassionate opportunities. Further, most research relies on retrospective-reports that may not accurately assess compassionate behaviors in everyday life.MethodConsequently, we collected 2,757 experience sampling survey responses from 125 participants (95 women, 27 men, 3 non-binary, Mage = 18.74, SDage = 1.66) to investigate whether attachment anxiety, avoidance, or their interaction were associated with differences in propensity for reporting compassionate opportunities, actions, and emotional responses to opportunities in everyday life across self-compassion, giving compassion, and receiving compassion.ResultsAnxiety was associated with greater likelihood of reporting all types of compassionate opportunities and less positive responses to opportunities to receive compassion. Avoidance was associated with less likelihood of reporting opportunities to give and receive compassion and less positive responses to opportunities to give compassion. Those high in anxiety but simultaneously low in avoidance reported fewer self-compassionate actions, but we identified no further differences in compassionate action.DiscussionThis study highlights the potential role of awareness of compassionate opportunities in attachment-related differences in compassion
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