129 research outputs found
Threshold values for the protection of marine ecosystems from NORM in subsea oil and gas infrastructure
Acknowledgements The authors thank Professor Claus Otto (Curtin University) and Professor Richard Neilson (National Decommissioning Centre, Aberdeen, UK.) for comments and support to the project team; and, Sam Jarvis (National Environment Resources Australia), Professor Peter Macreadie, Dr Rick Tinker, and the industry partners of the National Decommissioning Research Initiative for helpful comments to this project. Funding This research was funded by the Australian Government’s Industry Growth Centre National Energy Resources Australia (NERA) through a National Decommissioning Research Initiative (NDRI) grant to Curtin University. The NDRI project was funded by eight industry partners including Shell Australia, Esso Australia, Chevron Australia, BHP Petroleum, Woodside Energy, Santos Limited, ConocoPhillips Pipeline Australia, and Vermilion Oil and Gas Australia. AH is partly funded by the National Decommissioning Centre, Scotland, and the University of Aberdeen.Peer reviewedPublisher PD
The English National Chlamydia Screening Programme: variations in positivity in 2007/2008.
BACKGROUND: The purpose of this study was to examine variation in positivity within the English National Chlamydia Screening Programme during 2007/2008. METHODS: Data were analyzed using multivariable logistic regression. The outcome measure was positivity. Funnel plots were used to explore variation in positivity according to screening volume. RESULTS: Three hundred and thirty-four thousand nine hundred and two screening tests were done, 29% of which were in men. Overall positivity was 7.6% in men and 9.3% in women. For men, positivity increased rapidly to plateau from ages 19 to 24. For women, rates peaked at 18 years-those aged 21 being at the same risk of chlamydial infection as 16-year-olds. For men and women, positivity was generally higher for those of black or mixed ethnicity compared with whites, whereas Asians were at lower risk. Similarly, risk of infection for men and women varied by screening venue. Multivariable analysis showed that, for men and women positivity varied significantly with age, ethnicity, screening venue attended, whether the young people had had a new sexual partner in the past 3 months, and whether the patient had had 2 or more sexual partners in the past year. Positivity did not vary significantly with implementation phase. CONCLUSIONS: This is the largest description of testing for Chlamydia trachomatis in healthcare and nonhealthcare settings outside Genitourinary Medicine clinics in England and allowed a detailed analysis of positivity by age and ethnic group. Considerable heterogeneity exists and local health service commissioners need to ensure that the implementation of chlamydial screening reflects these differences
Ultra-endurance athletic performance suggests that energetics drive human morphological thermal adaptation
Both extinct and extant hominin populations display morphological features consistent with Bergmann's and Allen's Rules. However, the functional implications of the morphologies described by these ecological laws are poorly understood. We examined this through the lens of endurance running. Previous research concerning endurance running has focused on locomotor energetic economy. We considered a less-studied dimension of functionality, thermoregulation. The performance of male ultra-marathon runners (n = 88) competing in hot and cold environments was analysed with reference to expected thermoregulatory energy costs and the optimal morphologies predicted by Bergmann's and Allen's Rules. Ecogeographical patterning supporting both principles was observed in thermally challenging environments. Finishers of hot-condition events had significantly longer legs than finishers of cold-condition events. Furthermore, hot-condition finishers had significantly longer legs than those failing to complete hot-condition events. A degree of niche-picking was evident; athletes may have tailored their event entry choices in accordance with their previous race experiences. We propose that the interaction between prolonged physical exertion and hot or cold climates may induce powerful selective pressures driving morphological adaptation. The resulting phenotypes reduce thermoregulatory energetic expenditure, allowing diversion of energy to other functional outcomes such as faster running
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Travelling for Umrah:destination attributes, destination image, and post-travel intentions
This paper examines the links between cosmopolitanism, self-identity, and a desire for social interaction perceived destination image and behavioural intentions. A model tested using a sample of 538 Iranian visitors to Mecca for the purpose of Umrah. The result from the structural model suggests that destination attributes influence perceived destination image. Further, such tourists are likely to revisit or recommend Islamic destinations if their experience matches their perceived image of the destination. This implies that, while the religious characteristics of the destination remain important, destination managers cannot disregard the tangential, non-religious attributes of a destination which are crucial in order to satisfy more conventional tourist desires. As such, this study suggests that those managing religious travel destinations should endeavour to foster a welcoming image, where experience, interaction and tolerance are at the forefront of the destination’s offering
Point Source Polarimetry with the Gemini Planet Imager: Sensitivity Characterization with T5.5 Dwarf Companion HD 19467 B
Detecting polarized light from self-luminous exoplanets has the potential to provide key information about rotation, surface gravity, cloud grain size, and cloud coverage. While field brown dwarfs with detected polarized emission are common, no exoplanet or substellar companion has yet been detected in polarized light. With the advent of high contrast imaging spectro-polarimeters such as GPI and SPHERE, such a detection may now be possible with careful treatment of instrumental polarization. In this paper, we present 28 minutes of H-band GPI polarimetric observations of the benchmark T5.5 companion HD 19467 B. We detect no polarization signal from the target, and place an upper limit on the degree of linear polarization of p_(CL99.73%) ⩽ 2.4%. We discuss our results in the context of T dwarf cloud models and photometric variability
Using the Gerchberg-Saxton algorithm to reconstruct non-modulated pyramid wavefront sensor measurements
Adaptive optics (AO) is a technique to improve the resolution of ground-based
telescopes by correcting, in real-time, optical aberrations due to atmospheric
turbulence and the telescope itself. With the rise of Giant Segmented Mirror
Telescopes (GSMT), AO is needed more than ever to reach the full potential of
these future observatories. One of the main performance drivers of an AO system
is the wavefront sensing operation, consisting of measuring the shape of the
above mentioned optical aberrations. Aims. The non-modulated pyramid wavefront
sensor (nPWFS) is a wavefront sensor with high sensitivity, allowing the limits
of AO systems to be pushed. The high sensitivity comes at the expense of its
dynamic range, which makes it a highly non-linear sensor. We propose here a
novel way to invert nPWFS signals by using the principle of reciprocity of
light propagation and the Gerchberg-Saxton (GS) algorithm. We test the
performance of this reconstructor in two steps: the technique is first
implemented in simulations, where some of its basic properties are studied.
Then, the GS reconstructor is tested on the Santa Cruz Extreme Adaptive optics
Laboratory (SEAL) testbed located at the University of California Santa Cruz.
This new way to invert the nPWFS measurements allows us to drastically increase
the dynamic range of the reconstruction for the nPWFS, pushing the dynamics
close to a modulated PWFS. The reconstructor is an iterative algorithm
requiring heavy computational burden, which could be an issue for real-time
purposes in its current implementation. However, this new reconstructor could
still be helpful in the case of many wavefront control operations. This
reconstruction technique has also been successfully tested on the Santa Cruz
Extreme AO Laboratory (SEAL) bench where it is now used as the standard way to
invert nPWFS signal
Comparing helpful and hindering processes in good and poor outcome cases : a qualitative metasynthesis of eight Hermeneutic Single Case Efficacy Design studies
Objective: We tested qualitative metasynthesis of a series of Hermeneutic Single Case Efficacy Design (HSCED) studies as a method for comparing within-session processes that may explain good and poor therapeutic outcome. Method: We selected eight HSCED studies according to change in clients' scores on the Strathclyde Inventory (SI), a brief self-report instrument used to measure outcome in person-centered psychotherapy. Four of the case studies investigated the experience of clients whose pre-post change in SI scores showed improvement by the end of therapy, and the other four focused on clients whose change in SI scores indicated deterioration. We conducted a qualitative metasynthesis, adopting a generic descriptive-interpretive approach to analyze and compare the data generated by the HSCED studies. Results: In contrast to improvers, deteriorators appeared to be less ready to engage in therapeutic work at the beginning of therapy, and found the process more difficult; their therapists were less able to respond to these difficulties in a responsive, empathic manner; deteriorators were less able to cope successfully with changes of therapist and, eventually, gave up on therapy. Conclusion: We found that our qualitative metasynthesis of a series of HSCED studies produced a plausible explanation for the contrasting outcomes that occurred
Constraints on the architecture of the HD 95086 planetary system with the Gemini Planet Imager
We present astrometric monitoring of the young exoplanet HD 95086 b obtained
with the Gemini Planet Imager between 2013 and 2016. A small but significant
position angle change is detected at constant separation; the orbital motion is
confirmed with literature measurements. Efficient Monte Carlo techniques place
preliminary constraints on the orbital parameters of HD 95086 b. With 68%
confidence, a semimajor axis of 61.7^{+20.7}_{-8.4} au and an inclination of
153.0^{+9.7}_{-13.5} deg are favored, with eccentricity less than 0.21. Under
the assumption of a co-planar planet-disk system, the periastron of HD 95086 b
is beyond 51 au with 68% confidence. Therefore HD 95086 b cannot carve the
entire gap inferred from the measured infrared excess in the SED of HD 95086.
We use our sensitivity to additional planets to discuss specific scenarios
presented in the literature to explain the geometry of the debris belts. We
suggest that either two planets on moderately eccentric orbits or three to four
planets with inhomogeneous masses and orbital properties are possible. The
sensitivity to additional planetary companions within the observations
presented in this study can be used to help further constrain future dynamical
simulations of the planet-disk system.Comment: Accepted for publication in ApJ
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