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Vromans L, Schweitzer RD, Farrell L, Correa-Velez I, Brough M, Murray K, Lenette C. 'Her cry is my cry': resettlement experiences of refugee women at risk recently resettled in Australia. Public Health 2018; 158:149-155. [PMID: 29631727 DOI: 10.1016/j.puhe.2018.03.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Revised: 02/20/2018] [Accepted: 03/07/2018] [Indexed: 11/26/2022]
Abstract
OBJECTIVES Refugee women entering resettlement countries on woman-at-risk visas represent a particularly vulnerable population. While their specific gender-based resettlement will likely differ from the general refugee population, little is known about their experiences of early resettlement, with which to inform resettlement policy and practice. This research aimed to explore lived experiences of recently resettled refugee women at risk in Australia. STUDY DESIGN Qualitative research used focus groups and a framework approach to identify and explicate common themes in participants' experience. METHODS Two focus groups with a purposive sample of African and Afghan refugee women at risk (N = 10), aged 22-53 years, were conducted in South East Queensland, Australia (October 2016), recruited with the assistance of a local resettlement service. Discussions were audiotaped, transcribed, and themes explicated. RESULTS Six superordinate themes emerged: (1) sentiment of gratitude; (2) sense of loneliness and disconnection; (3) feeling incapable; (4) experiencing distress and help-seeking; (5) experiencing financial hardship; and (6) anticipating the future. CONCLUSIONS Findings indicate that resettlement policy, programs, and practice that explicitly target the needs of women-at-risk refugees are warranted, including a longer period of active service provision with specific attention to strategies that address the women's social connection, self-efficacy, emotional well-being, and financial hardships.
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Bhenderu LSS, Murray K, Stepurko N, Wang X, Hyvönen M, D'Arcy S. Comparing the Solution Conformation and Activin‐binding of Follistatin Isoforms. FASEB J 2018. [DOI: 10.1096/fasebj.2018.32.1_supplement.659.5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Shepherd T, Ballal H, Hunt C, Bharat C, Murray K, Kamyab R, Saunders C. P5 Arm morbidity: Is there a difference if completion axillary dissection is undertaken in the same procedure as sentinel node biopsy or as a second operation? Breast 2018. [DOI: 10.1016/j.breast.2018.02.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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Younossi ZM, Stepanova M, Schwarz KB, Wirth S, Rosenthal P, Gonzalez-Peralta R, Murray K, Henry L, Hunt S. Quality of life in adolescents with hepatitis C treated with sofosbuvir and ribavirin. J Viral Hepat 2018; 25:354-362. [PMID: 29193603 DOI: 10.1111/jvh.12830] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Accepted: 10/05/2017] [Indexed: 12/11/2022]
Abstract
Chronic HCV infection has been associated with impairment of HRQL in both adults and paediatric patients. Our aim was to assess the HRQL of HCV-positive children treated with SOF + RBV. The data for this post hoc analysis were collected in a phase 2 open-label multinational study that evaluated safety and efficacy of SOF (400 mg/day) plus RBV (weight-based up to 1400 mg/day) for 12 or 24 weeks in adolescents with chronic HCV (GS-US-334-1112). Patients and their parents/guardians completed the PedsQL-4.0-SF-15 questionnaire at baseline, at the end of treatment and in post-treatment follow-up. We included 50 adolescents with HCV genotype 2 and 3 without cirrhosis (14.8 ± 1.9 years; male: 58%; treatment-naïve: 82%; vertically transmitted HCV: 70%). After treatment, 100% of patients with HCV genotype 2 and 95% with genotype 3 achieved SVR-12. During treatment with SOF + RBV, there were no significant decrements in any of patients' self-reported or parent-proxy-reported PRO scores regardless of treatment duration (all P > .05). After treatment cessation, we recorded a statistically significant improvement in patients' self-reported Social Functioning score by post-treatment week 12: on average, +4.8 points on a 0-100 scale (P = .02). By post-treatment week 24, parent-proxy-reported School Functioning score increased by, on average, +13.0 points (P = .0065). In multivariate analysis, history of abdominal pain and psychiatric disorders were predictive of impaired HRQL in adolescents with HCV (P < .05). Adolescents with HCV do not seem to experience any HRQL decrement during treatment with SOF + RBV and experience some improvement of their HRQL scores after achieving SVR.
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D'Arcy S, Karamitros CS, Stone E, Georgiou G, Murray K. Dynamics of L‐Kynureninase Orthologs during Catalysis. FASEB J 2018. [DOI: 10.1096/fasebj.2018.32.1_supplement.527.13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Pusceddu MM, Murray K, Gareau MG. Targeting the Microbiota, from Irritable Bowel Syndrome to Mood Disorders: Focus on Probiotics and Prebiotics. CURRENT PATHOBIOLOGY REPORTS 2018; 6:1-13. [PMID: 29785336 PMCID: PMC5958897 DOI: 10.1007/s40139-018-0160-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
PURPOSE OF REVIEW The crosstalk between the gut and the brain has revealed a complex communication system responsible for maintaining a proper gastrointestinal homeostasis as well as affect emotional mood and cognitive functions. Recent research has revealed that beneficial manipulation of the microbiota by probiotics and prebiotics represent an emerging and novel strategy for the treatment of a large spectrum of diseases ranging from visceral pain to mood disorders. The review critically evaluates current knowledge of the effects exerted by both probiotics and prebiotics in irritable bowel syndrome (IBS) and mood disorders such as anxiety and depression. RECENT FINDINGS Relevant literature was identified through a search of MEDLINE via PubMed using the following words, "probiotics", "prebiotics", "microbiota", and "gut-brain axis" in combination with "stress", "depression", "IBS", and "anxiety". A number of trials have shown efficacy of probiotics and prebiotics in ameliorating both IBS related symptoms and emotional states. However, limitations have been found especially due to the small number of clinical studies, studies design, patient sample size, and placebo effect. SUMMARY Nonetheless, current finding supports the view that beneficial manipulation of the microbiota through both probiotics and prebiotics intake represents a novel attractive strategy to treat gut-brain axis disorders such as IBS and depression.
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Chacko B, Whitley M, Beckmann U, Murray K, Rowley M. Postoperative Euglycaemic Diabetic Ketoacidosis Associated with Sodium–Glucose Cotransporter-2 Inhibitors (Gliflozins): A Report of Two Cases and Review of the Literature. Anaesth Intensive Care 2018. [DOI: 10.1177/0310057x1804600212] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Sodium–glucose cotransporter-2 inhibitor (SGLT2i)-associated euglycaemic diabetic ketoacidosis (euDKA) is a serious and increasingly recognised complication of treatment with this class of oral hypoglycaemic agents and can present a diagnostic challenge, resulting in delayed recognition, inappropriate treatment and potentially life-threatening acidosis. We present two cases of patients developing SGLT2i-associated euDKA in the early postoperative period. We support ceasing SGLT2i for 72 hours preoperatively and would suggest continuing to withhold the medication until oral intake is restored, and recommend a wider awareness of SGLT2i-associated diabetic ketoacidosis (DKA) amongst patients and their healthcare providers with an emphasis on checking ketone levels irrespective of blood glucose levels in the postoperative setting.
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Murray K, Moyer P, Wu F, Goyette JB, Warriner K. Inactivation of Listeria monocytogenes on and within Apples Destined for Caramel Apple Production by Using Sequential Forced Air Ozone Gas Followed by a Continuous Advanced Oxidative Process Treatment. J Food Prot 2018; 81:357-364. [PMID: 29393682 DOI: 10.4315/0362-028x.jfp-17-306] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
This study evaluated the efficacy of using sequential forced air ozone followed by an advanced oxidative process (AOP) treatment to inactivate Listeria monocytogenes on and within Empire apples. The forced air ozone treatment consisted of a reactor that introduced ozone (6 g/h) into an airstream that flowed through an apple bed (ca. 30 cm in depth). Before treatment, the apples were conditioned at 4°C to ensure that condensate had formed before the apples were transferred to the reactor. The condensate ensured sufficient relative humidity to enhance the antimicrobial action of ozone. Air was passed through the apple bed at 9.3 m/s, and the ozone was introduced after 10 min. The ozone concentration measured after exiting the apple bed reached a steady state of 23 ppm. A 20-min ozone treatment supported a 2.12- to 3.07-log CFU reduction of L. monocytogenes, with no significant effect of apple position within the bed. The AOP-based method was a continuous process whereby hydrogen peroxide was introduced as a vapor into a reactor illuminated by UV-C and ozone-emitting lamps that collectively generated hydroxyl radicals. Operating the AOP reactor with UV-C light (54-mJ cm2 dose), 6% (v/v) hydrogen peroxide, 2 g/h ozone, and a chamber temperature of 48°C resulted in a 3-log CFU reduction of L. monocytogenes on the surface of the apples and internally within the scar tissue. Applying a caramel coating, from a molten solution (at 80°C), resulted in a 0.5-log CFU reduction of L. monocytogenes on the apple surface. In apples treated with the sequential process, L. monocytogenes could only be recovered sporadically by enrichment and did not undergo outgrowth when the caramel apples were stored at 22°C for 19 days. However, growth of L. monocytogenes within the core, but not the surface, was observed from caramel apples prepared from nontreated control fruit.
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Manderson AA, Murray K, Turlach BA. Dynamic Bayesian forecasting of AFL match results using the Skellam distribution. AUST NZ J STAT 2018. [DOI: 10.1111/anzs.12225] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Seidler PM, Boyer DR, Rodriguez JA, Sawaya MR, Cascio D, Murray K, Gonen T, Eisenberg DS. Structure-based inhibitors of tau aggregation. Nat Chem 2018; 10:170-176. [PMID: 29359764 PMCID: PMC5784779 DOI: 10.1038/nchem.2889] [Citation(s) in RCA: 199] [Impact Index Per Article: 33.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Accepted: 10/04/2017] [Indexed: 12/14/2022]
Abstract
Aggregated tau protein is associated with over 20 neurological disorders, which include Alzheimer's disease. Previous work has shown that tau's sequence segments VQIINK and VQIVYK drive its aggregation, but inhibitors based on the structure of the VQIVYK segment only partially inhibit full-length tau aggregation and are ineffective at inhibiting seeding by full-length fibrils. Here we show that the VQIINK segment is the more powerful driver of tau aggregation. Two structures of this segment determined by the cryo-electron microscopy method micro-electron diffraction explain its dominant influence on tau aggregation. Of practical significance, the structures lead to the design of inhibitors that not only inhibit tau aggregation but also inhibit the ability of exogenous full-length tau fibrils to seed intracellular tau in HEK293 biosensor cells into amyloid. We also raise the possibility that the two VQIINK structures represent amyloid polymorphs of tau that may account for a subset of prion-like strains of tau.
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Manderson AA, Cripps E, Murray K, Turlach BA. Monotone polynomials using BUGS and Stan. AUST NZ J STAT 2017. [DOI: 10.1111/anzs.12207] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Keane N, Fragkos K, Patel P, Murray K, Obbard S, Ajibodu S, O’callaghan S, Kwok H, Paulon E, Barragry J, Mehta S, Di Caro S, Rahman F. MON-P096: Biochemical Measurements as a Predictor of Survival in Patients with Incurable Cancers Receiving Home Parenteral Nutrition (HPN). Clin Nutr 2017. [DOI: 10.1016/s0261-5614(17)30987-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Goebel THW, Walter JI, Murray K, Brodsky EE. Comment on "How will induced seismicity in Oklahoma respond to decreased saltwater injection rates?" by C. Langenbruch and M. D. Zoback. SCIENCE ADVANCES 2017; 3:e1700441. [PMID: 28808681 PMCID: PMC5550223 DOI: 10.1126/sciadv.1700441] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Accepted: 07/12/2017] [Indexed: 06/07/2023]
Abstract
The state of Oklahoma has experienced an unprecedented increase in earthquake activity since 2009, likely driven by large-scale wastewater injection operations. Statewide injection rates peaked in early 2015 and steadily decreased thereafter, approximately coinciding with collapsing oil prices and regulatory action. If seismic activity is primarily driven by fluid injection, a noticeable seismogenic response to the decrease in injection rates is expected. Langenbruch and Zoback suggest that "the probability of potentially damaging larger events, should significantly decrease by the end of 2016 and approach historic levels within a few years." We agree that the rate of small earthquakes has decreased toward the second half of 2016. However, their specific predictions about seismic hazard require reexamination. We test the influence of the model parameters of Langenbruch and Zoback based on fits to observed seismicity distributions. The results suggest that a range of realistic aftershock decay rates and b values can lead to an increase in moderate earthquake probabilities from 37 to 80% in 2017 without any further alteration to the model. In addition, the observation that all four M ≥ 5 earthquakes to date occurred when injection rates were below the triggering threshold of Langenbruch and Zoback challenges the applicability of the model for the most societally significant events.
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Borner A, Murray K, Trotter C, Pearson J. Baseline aortic pulse wave velocity is associated with central and peripheral pressor responses during the cold pressor test in healthy subjects. Physiol Rep 2017; 5:5/14/e13357. [PMID: 28733312 PMCID: PMC5532490 DOI: 10.14814/phy2.13357] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Accepted: 06/20/2017] [Indexed: 11/24/2022] Open
Abstract
Cold environmental temperatures increase sympathetic nerve activity and blood pressure, and increase the risk of acute cardiovascular events in aged individuals. The acute risk of cardiovascular events increases with aortic pulse wave velocity as well as elevated central and peripheral pulse pressures. The aim of this study was to examine the independent influence of aortic pulse wave velocity upon central and peripheral pressor responses to sympathetic activation via the cold pressor test (CPT). Twenty‐two healthy subjects (age: 18–73 years) completed a CPT with the left hand immersed in 2–4°C water for 3 min. During the CPT, central (from: 36 ± 7 to: 51 ± 12 mmHg) and peripheral pulse pressure increased (from: 54 ± 7 to: 66 ± 11; both P < 0.05). In all subjects the increase in central pulse pressure during the CPT was independently associated with baseline aortic pulse wave velocity (r2 = 0.221, P = 0.027) but not age (P > 0.05). In a subset of subjects with higher arterial stiffness, the increase in peripheral pulse pressure during the CPT was independently associated with baseline aortic pulse wave velocity (r2 = 0.415, P = 0.032) but not age (P > 0.05). These data indicate that central and peripheral pulse pressure responses during sympathetic activation are positively and independently associated with aortic pulse wave velocity through a wide age range. Decreasing aortic pulse wave velocity in aged individuals with elevated arterial stiffness may help reduce the incidence of acute cardiovascular events upon exposure to cold environmental temperatures.
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Allen T, Murray K, Zambrana-Torrelio C, Morse S, Rondinini C, di Marco M, Olival K, Daszak P. Corrigendum to “Global correlates of emerging zoonoses: Anthropogenic, environmental, and biodiversity risk factors” [Int. J. Infect. Dis. 53 (Supplement) (December 2016) 21]. Int J Infect Dis 2017. [DOI: 10.1016/j.ijid.2017.03.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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Budgeon CA, Murray K, Turlach BA, Baker S, Villemagne VL, Burnham SC. Constructing longitudinal disease progression curves using sparse, short-term individual data with an application to Alzheimer's disease. Stat Med 2017; 36:2720-2734. [PMID: 28444781 DOI: 10.1002/sim.7300] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Revised: 03/01/2017] [Accepted: 03/11/2017] [Indexed: 12/13/2022]
Abstract
In epidemiology, cohort studies utilised to monitor and assess disease status and progression often result in short-term and sparse follow-up data. Thus, gaining an understanding of the full-term disease pathogenesis can be difficult, requiring shorter-term data from many individuals to be collated. We investigate and evaluate methods to construct and quantify the underlying long-term longitudinal trajectories for disease markers using short-term follow-up data, specifically applied to Alzheimer's disease. We generate individuals' follow-up data to investigate approaches to this problem adopting a four-step modelling approach that (i) determines individual slopes and anchor points for their short-term trajectory, (ii) fits polynomials to these slopes and anchor points, (iii) integrates the reciprocated polynomials and (iv) inverts the resulting curve providing an estimate of the underlying longitudinal trajectory. To alleviate the potential problem of roots of polynomials falling into the region over which we integrate, we propose the use of non-negative polynomials in Step 2. We demonstrate that our approach can construct underlying sigmoidal trajectories from individuals' sparse, short-term follow-up data. Furthermore, to determine an optimal methodology, we consider variations to our modelling approach including contrasting linear mixed effects regression to linear regression in Step 1 and investigating different orders of polynomials in Step 2. Cubic order polynomials provided more accurate results, and there were negligible differences between regression methodologies. We use bootstrap confidence intervals to quantify the variability in our estimates of the underlying longitudinal trajectory and apply these methods to data from the Alzheimer's Disease Neuroimaging Initiative to demonstrate their practical use. Copyright © 2017 John Wiley & Sons, Ltd.
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Spaliviero M, Power N, Murray K, Sjoberg D, Benfante N, Bernstein M, Wren J, Russo P, Coleman J. Phase 3 randomized trial of intravenous mannitol versus placebo prior to renal ischemia during partial nephrectomy: Impact on renal functional outcomes. ACTA ACUST UNITED AC 2017. [DOI: 10.1016/s1569-9056(17)30279-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Allen T, Murray K, Zambrana-Torrelio C, Morse S, Rondinini C, Presti VDML, Olival K, Daszak P. Global correlates of emerging zoonoses: Anthropogenic, environmental, and biodiversity risk factors. Int J Infect Dis 2016. [DOI: 10.1016/j.ijid.2016.11.057] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Keane N, Fragkos K, Patel P, Obbard S, Murray K, Guilvezan S, O'Hanlon F, Kok K, Paulon E, Di Caro S, Mehta S, Rahman F. MON-P068: An Updated Audit of Home Parenteral Nutrition (HPN) in Palliative Oncology Patients - A UK Single Centre Case Series with Survival Analysis. Clin Nutr 2016. [DOI: 10.1016/s0261-5614(16)30702-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Mimche S, Ahn D, Kiani M, Elahi H, Murray K, Easley K, Sokoloff A, Ghovanloo M. Tongue implant for assistive technologies: Test of migration, tissue reactivity and impact on tongue function. Arch Oral Biol 2016; 71:1-9. [PMID: 27372202 DOI: 10.1016/j.archoralbio.2016.06.019] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2015] [Revised: 06/14/2016] [Accepted: 06/17/2016] [Indexed: 11/25/2022]
Abstract
OBJECTIVE The Tongue Drive System (TDS) is a new wearable assistive technology (AT), developed to translate voluntary tongue movements to user-defined computer commands by tracking the position of a titanium-encased magnetic tracer (Ti-Mag) implanted into the tongue. TDS application, however, is constrained by limited information on biological consequence and safety of device implantation into the tongue body. Here we implant a stainless-steel pellet in the rat tongue and assay pellet migration, tongue lick function, and tongue histology to test the safety and biocompatibility of unanchored tongue implants. DESIGN Water consumption, weight and lick behavior were measured before and for >24days after implantation of a stainless-steel spherical pellet (0.5mm) into the anterior tongue body of twelve adult male rats. X-rays were obtained weekly to assess pellet migration. Pellet location and tissue reaction to implantation were determined by post-mortem dissection and histology of the anterior tongue. RESULTS By dissection pellets were distributed across the transverse plane of the tongue. Measures of water consumption, weight, and lick behavior were unchanged by implantation except for a decrease in consumption immediately post-implantation in some animals. By X-ray, there was no migration of the implant, a finding supported by pellet encapsulation demonstrated histologically. Measures of lick behavior were minimally impacted by implantation. CONCLUSION A smooth spherical stainless-steel implant in the anterior tongue of the rat does not migrate, is encapsulated and does not substantially impact lick behavior. These findings support the implantation of small tracers in the anterior tongue in humans for operating wearable assistive technologies.
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Guillén-Torres MÁ, Murray K, Yun H, Caverley M, Cretu E, Chrostowski L, Jaeger NAF. Effects of backscattering in high-Q, large-area silicon-on-insulator ring resonators. OPTICS LETTERS 2016; 41:1538-1541. [PMID: 27192281 DOI: 10.1364/ol.41.001538] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We demonstrate large-area silicon-on-insulator ring resonators with Q values of about 2×106 at critical coupling and 3.6×106 for heavily undercoupled conditions. A model has been developed to understand the impact of waveguide backscattering and subcomponent imperfections on the spectral response of our devices. The model predicts the appearance of signals at ports that would not have them under backscattering-free, ideal-power-splitting conditions. The predictions of our model are shown to match the phenomena observed in our measurements.
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Hoad CL, Menys A, Garsed K, Marciani L, Hamy V, Murray K, Costigan C, Atkinson D, Major G, Spiller RC, Taylor SA, Gowland PA. Colon wall motility: comparison of novel quantitative semi-automatic measurements using cine MRI. Neurogastroenterol Motil 2016; 28:327-35. [PMID: 26612075 DOI: 10.1111/nmo.12727] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Accepted: 10/15/2015] [Indexed: 02/08/2023]
Abstract
BACKGROUND Recently, cine magnetic resonance imaging (MRI) has shown promise for visualizing movement of the colonic wall, although assessment of data has been subjective and observer dependent. This study aimed to develop an objective and semi-automatic imaging metric of ascending colonic wall movement, using image registration techniques. METHODS Cine balanced turbo field echo MRI images of ascending colonic motility were acquired over 2 min from 23 healthy volunteers (HVs) at baseline and following two different macrogol stimulus drinks (11 HVs drank 1 L and 12 HVs drank 2 L). Motility metrics derived from large scale geometric and small scale pixel movement parameters following image registration were developed using the post ingestion data and compared to observer grading of wall motion. Inter and intra-observer variability in the highest correlating metric was assessed using Bland-Altman analysis calculated from two separate observations on a subset of data. KEY RESULTS All the metrics tested showed significant correlation with the observer rating scores. Line analysis (LA) produced the highest correlation coefficient of 0.74 (95% CI: 0.55-0.86), p < 0.001 (Spearman Rho). Bland-Altman analysis of the inter- and intra-observer variability for the LA metric, showed almost zero bias and small limits of agreement between observations (-0.039 to 0.052 intra-observer and -0.051 to 0.054 inter-observer, range of measurement 0-0.353). CONCLUSIONS & INFERENCES The LA index of colonic motility derived from cine MRI registered data provides a quick, accurate and non-invasive method to detect wall motion within the ascending colon following a colonic stimulus in the form of a macrogol drink.
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Murray K, Müller S, Turlach BA. Fast and flexible methods for monotone polynomial fitting. J STAT COMPUT SIM 2016. [DOI: 10.1080/00949655.2016.1139582] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Murray K, Zasowski E, Rybak MJ. Vancomycin Exposure Predicts Early Clinical Response in Complicated Skin and Soft Tissue Infections Caused by Methicillin-Resistant Staphylococcus aureus. Open Forum Infect Dis 2015. [DOI: 10.1093/ofid/ofv133.517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Jayatilleka H, Murray K, Guillén-Torres MÁ, Caverley M, Hu R, Jaeger NAF, Chrostowski L, Shekhar S. Wavelength tuning and stabilization of microring-based filters using silicon in-resonator photoconductive heaters. OPTICS EXPRESS 2015; 23:25084-25097. [PMID: 26406708 DOI: 10.1364/oe.23.025084] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We demonstrate that n-doped resistive heaters in silicon waveguides show photoconductive effects with high responsivities. These photoconductive heaters, integrated into microring resonator (MRR)-based filters, were used to automatically tune and stabilize the filter's resonance wavelength to the input laser's wavelength. This is achieved without requiring dedicated defect implantations, additional material depositions, dedicated photodetectors, or optical power tap-outs. Automatic wavelength stabilization of first-order MRR and second-order series-coupled MRR filters is experimentally demonstrated. Open eye diagrams were obtained for data transmission at 12.5 Gb/s while the temperature was varied by 5 °C at a rate of 0.28 °C/s. We theoretically show that series-coupled MRR-based filters of any order can be automatically tuned by using photoconductive heaters to monitor the light intensity in each MRR, and sequentially aligning the resonance of each MRR to the laser's wavelength.
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