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Search Results: 1 - 10 of 19046 matches for " Andrew Morgan "
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Temperature diagnostics of the solar atmosphere using SunPy
Andrew Leonard,Huw Morgan
Computer Science , 2014,
Abstract: The solar atmosphere is a hot (about 1MK), magnetised plasma of great interest to physicists. There have been many previous studies of the temperature of the Sun's atmosphere (Plowman2012, Wit2012, Hannah2012, Aschwanden2013, etc.). Almost all of these studies use the SolarSoft software package written in the commercial Interactive Data Language (IDL), which has been the standard language for solar physics. The SunPy project aims to provide an open-source library for solar physics. This work presents (to the authors' knowledge) the first study of its type to use SunPy rather than SolarSoft. This work uses SunPy to process multi-wavelength solar observations made by the Atmospheric Imaging Assembly (AIA) instrument aboard the Solar Dynamics Observatory (SDO) and produce temperature maps of the Sun's atmosphere. The method uses SunPy's utilities for querying databases of solar events, downloading solar image data, storing and processing images as spatially aware Map objects, and tracking solar features as the Sun rotates. An essential consideration in developing this software is computational efficiency due to the large amount of data collected by AIA/SDO, and in anticipating new solar missions which will result in even larger sets of data. An overview of the method and implementation is given, along with tests involving synthetic data and examples of results using real data for various regions in the Sun's atmosphere.
Transit Target Selection Using Reduced Proper Motions
Andrew Gould,Christopher W. Morgan
Physics , 2002, DOI: 10.1086/346131
Abstract: In searches for planetary transits in the field, well over half of the survey stars are typically giants or other stars that are too large to permit straightforward detection of planets. For all-sky searches of bright V<~11 stars, the fraction is ~90%. We show that the great majority of these contaminants can be removed from the sample by analyzing their reduced proper motions (RPMs): giants have much lower RPMs than dwarfs of the same color. We use Hipparcos data to design a RPM selection function that eliminates most evolved stars, while rejecting only 9% of viable transit targets. Our method can be applied using existing or soon-to-be-released all-sky data to stars V<12.5 in the northern hemisphere and V<12 in the south. The method degrades at fainter magnitudes, but does so gracefully. For example, at V=14 it can still be used to eliminate giants redward of V-I~0.95, that is, the blue edge of the red giant clump.
Successful conservative management of a colorenal fistula complicating percutaneous cryoablation of renal tumors: a case report
Morgan Amir IS,Doble Andrew,Davies R Justin
Journal of Medical Case Reports , 2012, DOI: 10.1186/1752-1947-6-365
Abstract: Introduction Colorenal fistula is a rare phenomenon and may complicate percutaneous cryoablation of renal cell carcinoma. Treatment remains controversial. Case presentation A 62-year-old Caucasian man presented with pneumaturia and left flank pain six weeks following ultrasound-guided percutaneous cryoablation of two recurrent lesions in the left kidney 14 years after partial left nephrectomy for a left renal cell carcinoma. A computed tomography scan eight weeks after cryoablation revealed a cryoablated mass with adjacent stranding and adherent descending colon as well as bubbles of gas in the area of stranding, the left collecting system, and the bladder. These features were consistent with a colorenal fistula at the site of previous ablation. Successful resolution of the fistula, both clinical and radiological, was achieved following a complete conservative non-interventional out-patient approach. No ureteric stent or surgical intervention was employed. Conclusions In the absence of severe symptoms or sepsis, complete conservative management of a colorenal fistula complicating percutaneous cryoablation of renal tumors should be considered prior to interventional stenting or resectional surgery.
Self-Healing of Ionomeric Polymers with Carbon Fibers from Medium-Velocity Impact and Resistive Heating
Vishnu Baba Sundaresan,Andrew Morgan,Matt Castellucci
Smart Materials Research , 2013, DOI: 10.1155/2013/271546
Abstract: Self-healing materials science has seen significant advances in the last decade. Recent efforts have demonstrated healing in polymeric materials through chemical reaction, thermal treatment, and ultraviolet irradiation. The existing technology for healing polymeric materials through the aforementioned mechanisms produces an irreversible change in the material and makes it unsuitable for subsequent healing cycles. To overcome these disadvantages, we demonstrate a new composite self-healing material made from an ionomer (Surlyn) and carbon fiber that can sustain damage from medium-velocity impact and heal from the energy of the impact. Furthermore, the carbon fiber embedded in the polymer matrix results in resistive heating of the polymer matrix locally, melts the ionomer matrix around the damage, and heals the material at the damaged location. This paper presents methods to melt-process Surlyn with carbon fiber and demonstrates healing in the material through medium-velocity impact tests, resistive heating, and imaging through electron and optical microscopy. A new metric for quantifying self-healing in the sample, called width-heal ratio, is developed, and we report that the Surlyn-carbon fiber-based material under an optimal rate of heating and at the correct temperature has a width-heal ratio of >0.9, thereby demonstrating complete recovery from the damage. 1. Introduction Damage detection and self-healing are unique properties of biological materials and systems. In such systems, a damage event triggers internal processes that generate the healing response and extend the life of the material. This unique property of biological materials has served as the inspiration for self-healing materials in engineering. In the most common self-healing concepts developed to date, damage events are directly or electronically coupled to the release of the healing agents to heal the damage in the material. The most commonly used healing agents such as chemical binders, heat, and light alter the chemical composition and microstructure of the material to heal the damage and restore strength at the damage site. The capsule-based method developed by White and coworkers [1–4] uses a chemical binder that is released into the matrix of the composite material in the event of a damage. The binder combines with the matrix or hardening agent present in adjacent microcapsule to heal the damage. A variation of the microcapsule-based technique uses vascular networks filled with healing agents to heal structural damage [5–12]. In another variation of this method, hollow glass
Exploring the Evidence Base for Acupuncture in the Treatment of Ménière's Syndrome—A Systematic Review
Andrew F. Long,Mei Xing,Ken Morgan,Alison Brettle
Evidence-Based Complementary and Alternative Medicine , 2011, DOI: 10.1093/ecam/nep047
Abstract: Ménière's syndrome is a long-term, progressive disease that damages the balance and hearing parts of the inner ear. To address the paucity of information on which evidence-based treatment decisions should be made, a systematic review of acupuncture for Ménière's syndrome was undertaken. The method used was a systematic review of English and Chinese literature, from six databases for randomized, non-randomized and observational studies. All studies were critically appraised and a narrative approach to data synthesis was adopted. Twenty-seven studies were included in this review (9 in English and 18 in Chinese languages): three randomized controlled trials, three non-randomized controlled studies and four pre-test, post-test designs. All but one of the studies was conducted in China. The studies covered body acupuncture, ear acupuncture, scalp acupuncture, fluid acupuncture point injection and moxibustion. The studies were of varying quality. The weight of evidence, across all study types, is of beneficial effect from acupuncture, for those in an acute phase or those who have had Ménière's syndrome for a number of years. The review reinforces the importance of searching for studies from English and Chinese literature. The transferability of the findings from China to a Western context needs confirmation. Further research is also needed to clarify questions around the appropriate frequency and number of treatment/courses of acupuncture. The weight of evidence suggests a potential benefit of acupuncture for persons with Ménière's disease, including those in an acute phase and reinforces the importance of searching for published studies in the Chinese language. 1. Introduction Ménière's syndrome is a long-term, progressive disease that damages the balance and hearing parts of the inner ear. It is most common between the ages of 40 and 50 and rare in children and onset after the age of 60. Its incidence is about 1 in 1000, equally distributed between men and women and well documented in Caucasian, African-American and Asian races [1]. The etiology and treatment of Ménière's disease is not fully understood. In a literature-based, clinical review of the diagnosis and treatment of Ménière's disease, Saeed [2] commented that “currently, the treatment of Ménière's disease is empirical. As yet, no treatment has prospectively modified the clinical course of the condition and thereby prevented the progressive hearing loss." Indeed, Thorp et al. [3] in a critical review of studies of medical and surgical approaches queried whether any evidence-based medicine existed
High Macroalgal Cover and Low Coral Recruitment Undermines the Potential Resilience of the World's Southernmost Coral Reef Assemblages
Andrew S. Hoey, Morgan S. Pratchett, Christopher Cvitanovic
PLOS ONE , 2011, DOI: 10.1371/journal.pone.0025824
Abstract: Coral reefs are under increasing pressure from anthropogenic and climate-induced stressors. The ability of reefs to reassemble and regenerate after disturbances (i.e., resilience) is largely dependent on the capacity of herbivores to prevent macroalgal expansion, and the replenishment of coral populations through larval recruitment. Currently there is a paucity of this information for higher latitude, subtropical reefs. To assess the potential resilience of the benthic reef assemblages of Lord Howe Island (31°32′S, 159°04′E), the worlds' southernmost coral reef, we quantified the benthic composition, densities of juvenile corals (as a proxy for coral recruitment), and herbivorous fish communities. Despite some variation among habitats and sites, benthic communities were dominated by live scleractinian corals (mean cover 37.4%) and fleshy macroalgae (20.9%). Live coral cover was higher than in most other subtropical reefs and directly comparable to lower latitude tropical reefs. Juvenile coral densities (0.8 ind.m?2), however, were 5–200 times lower than those reported for tropical reefs. Overall, macroalgal cover was negatively related to the cover of live coral and the density of juvenile corals, but displayed no relationship with herbivorous fish biomass. The biomass of herbivorous fishes was relatively low (204 kg.ha?1), and in marked contrast to tropical reefs was dominated by macroalgal browsing species (84.1%) with relatively few grazing species. Despite their extremely low biomass, grazing fishes were positively related to both the density of juvenile corals and the cover of bare substrata, suggesting that they may enhance the recruitment of corals through the provision of suitable settlement sites. Although Lord Howe Islands' reefs are currently coral-dominated, the high macroalgal cover, coupled with limited coral recruitment and low coral growth rates suggest these reefs may be extremely susceptible to future disturbances.
A survey of medical students to assess their exposure to and knowledge of renal transplantation
Anusha G Edwards, Andrew R Weale, Justin D Morgan
BMC Medical Education , 2004, DOI: 10.1186/1472-6920-4-32
Abstract: A questionnaire was distributed to final year students at a single medical school in the UK to assess their exposure to and knowledge of renal transplantation.Although 46% of responding students had examined a transplant recipient, only 14% had ever witnessed the surgery. Worryingly, 9% of students believed that xenotransplantation commonly occurs in the UK and 35% were unable to name a single drug that a recipient may need to take.This survey demonstrates a lack of exposure to, and knowledge of, the field of renal transplantation. Recommendations to address the problems with the recruitment of surgeons and donation of organs, by targeting medical students are made.With the potential for improved quality of life and increased life expectancy, renal transplantation is the first choice treatment for most patients with end-stage renal failure [1,2]. However, in the UK there is an ever-increasing disparity between the number of patients on the waiting list and those being transplanted [3]. This is predominantly due to a rise in the incidence of renal failure amongst an aging, racially diverse society in conjunction with a shortage of donated organs [4].The field of renal transplantation also suffers from a lack of surgeons. Indeed, it is predicted that by the year 2005 there will a shortage of over twenty consultant renal transplant surgeons [5].Any measures to deal with these problems must include educating and attracting the doctors of tomorrow; medical students [6,7]. However, the General Medical Council's core curriculum model for undergraduate teaching has lead to significant changes in the way that specialist subjects are taught [8]. This survey was conducted to assess the exposure to, and knowledge of, renal transplantation amongst medical students at a single medical school in the United Kingdom.In July 2003 a PRHO job fair was held for final year medical students of Bristol University, which all 140 students within the year attended. An anonymous questionnaire
Protocol for a randomised controlled trial investigating self-help email messages for sub-threshold depression: the Mood Memos study
Amy J Morgan, Anthony F Jorm, Andrew J Mackinnon
Trials , 2011, DOI: 10.1186/1745-6215-12-11
Abstract: The project is a randomised controlled trial of an automated preventive email-intervention aimed at people with sub-threshold depression. Adults aged 18+ with sub-threshold depression (as measured with the Patient Health Questionnaire-9), who are not already receiving professional treatment for depression, are eligible for admission to the study. Internet users will sign up via the study website http://www.moodmemos.com webcite and be randomly allocated to receive emails twice weekly for six weeks containing either self-help coping advice or general information about depression as a control. Outcomes will be assessed at the start, midpoint, and end of the intervention, as well as six months later. Outcomes assessed include symptoms, incidence of major depression, psychological distress, social and occupational functioning, coping strategies, and coping self-efficacy. The primary hypothesis is that the Mood Memo emails containing coping strategies will reduce depression symptoms and be better at preventing major depression than the control emails that contain general information about depression.Promotion of actions an individual can take to prevent physical disease is a technique often used in public health. This study applies this approach to mental health, and explores whether a low-cost, easily disseminated email-based campaign can improve self-help coping behaviour and prevent depression in adults with sub-threshold depression.Australia and New Zealand Clinical Trials Register (ANZCTR): ACTRN12609000925246Evidence suggests that depressive disorders exist on a continuum, rather than as qualitatively distinct syndromes [1]. Depressive symptoms that fall short of diagnostic criteria (variously termed sub-threshold, sub-clinical, sub-syndromal, mild, or minor depression) are prevalent [2], cause significant functional impairment [1,3], have considerable economic costs [4], and increase the risk of developing major depressive disorder [5]. Sub-threshold depression is
Self-Help for Depression via E-mail: A Randomised Controlled Trial of Effects on Depression and Self-Help Behaviour
Amy J. Morgan, Anthony F. Jorm, Andrew J. Mackinnon
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0066537
Abstract: Background Self-help or self-management strategies are commonly used to deal with depression, but not all are thought to be helpful. A previous study found that sub-threshold depression symptoms were improved by an e-mail intervention that encouraged the use of evidence-based self-help strategies. Aim To investigate whether these e-mails were effective for adults with a range of depression symptomatology including major depression. Method The study was a parallel-group randomised controlled trial. Adult participants with any level of depressive symptoms were recruited over the internet from the United Kingdom, Australia, Canada, Ireland, New Zealand and the United States. Participants were randomised to receive a series of e-mails either promoting the use of evidence-based self-help strategies or containing depression information as a control. E-mails were sent automatically twice a week for six weeks. Depression symptoms were assessed with the self-rated Patient Health Questionnaire depression scale (PHQ-9). Results 1736 participants with a wide range of symptom severity were recruited and assigned to active (n = 862) and control (n = 874) groups. However, there was a significant attrition rate, with 66.9% lost to follow-up at post-intervention. Both groups showed large improvements in depression symptoms overall, with no significant difference in improvement at the end of the study (mean difference in improvement 0.35 points, 95% CI: ?0.57 to 1.28, d = 0.11, 95% CI: ?0.06 to 0.27), although there was a small effect at the study mid-point. Results were similar for the sub-group of participants with major depression. The active group showed small to moderate improvements in self-help behaviour (d = 0.40, 95% CI: 0.23 to 0.56). Conclusions These results suggest that the e-mails were able to increase participants’ use of evidence-based self-help, but that this did not improve depression more than an attention control. ClinicalTrials.gov NCT01399502
Spatial Variation in Abundance, Size and Orientation of Juvenile Corals Related to the Biomass of Parrotfishes on the Great Barrier Reef, Australia
Melanie L. Trapon, Morgan S. Pratchett, Andrew S. Hoey
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0057788
Abstract: For species with complex life histories such as scleractinian corals, processes occurring early in life can greatly influence the number of individuals entering the adult population. A plethora of studies have examined settlement patterns of coral larvae, mostly on artificial substrata, and the composition of adult corals across multiple spatial and temporal scales. However, relatively few studies have examined the spatial distribution of small (≤50 mm diameter) sexually immature corals on natural reef substrata. We, therefore, quantified the variation in the abundance, composition and size of juvenile corals (≤50 mm diameter) among 27 sites, nine reefs, and three latitudes spanning over 1000 km on Australia’s Great Barrier Reef. Overall, 2801 juveniles were recorded with a mean density of 6.9 (±0.3 SE) ind.m?2, with Acropora, Pocillopora, and Porites accounting for 84.1% of all juvenile corals surveyed. Size-class structure, orientation on the substrate and taxonomic composition of juvenile corals varied significantly among latitudinal sectors. The abundance of juvenile corals varied both within (6–13 ind.m?2) and among reefs (2.8–11.1 ind.m?2) but was fairly similar among latitudes (6.1–8.2 ind.m?2), despite marked latitudinal variation in larval supply and settlement rates previously found at this scale. Furthermore, the density of juvenile corals was negatively correlated with the biomass of scraping and excavating parrotfishes across all sites, revealing a potentially important role of parrotfishes in determining distribution patterns of juvenile corals on the Great Barrier Reef. While numerous studies have advocated the importance of parrotfishes for clearing space on the substrate to facilitate coral settlement, our results suggest that at high biomass they may have a detrimental effect on juvenile coral assemblages. There is, however, a clear need to directly quantify rates of mortality and growth of juvenile corals to understand the relative importance of these mechanisms in shaping juvenile, and consequently adult, coral assemblages.
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