32 results
8 Detection of Feigned ADHD through an Experimental MMPI-2 ADHD Validity Scale among U.S. Military Veterans
- Christopher T. Burley, Timothy J. Arentsen, Jennifer S. Seeley McGee, Katie M. Califano, Holly R. Winiarski, Marcy C. Adler, Brad L. Roper
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- Journal:
- Journal of the International Neuropsychological Society / Volume 29 / Issue s1 / November 2023
- Published online by Cambridge University Press:
- 21 December 2023, pp. 693-694
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Objective:
The prevalence of ADHD diagnoses more than doubled in VA settings between 2009 and 2016 (Hale et al., 2020). However, attentional difficulties are not exclusive to ADHD and can also be seen in non-neurodevelopmental disorders, including depression, anxiety, substance use, and PTSD (Marshall et al., 2018, Suhr et al., 2008). Further, patients can easily feign symptoms of ADHD with few available instruments for accurate detection (Robinson & Rogers, 2018). Given the significant symptom overlap and rising rates of reported ADHD among Veterans, accurate detection of feigned ADHD is essential.
This study examined the utility of the experimental Dissimulation ADHD scale (Ds-ADHD; Robinson & Rogers, 2018) on the MMPI-2, in detecting feigned ADHD presentation within a mixed sample of Veterans.
Participants and Methods:In this retrospective study, 173 Veterans (Mage = 36.18, SDage = 11.10, Medu = 14.01, SDedu = 2.11, 88% male, 81% White, and 17% Black) were referred for neuropsychological evaluation of ADHD that included the MMPI-2 and up to 10 PVTs. Participants were assigned to a credible group (n=146) if they passed all PVTs or a non-credible group (n=27) if they failed two or more PVTs. Group assignment was also clinically confirmed. The Ds-ADHD was used to differentiate groups who either had credible or non-credible performance on cognitive measures. Consistent with Robinson and Rogers’ study, “true” answers (i.e., erroneous stereotypes) were coded as 1 and “false” answers were coded as 2, creating a 10- to 20-point scale. Lower scores were associated with a higher likelihood of a feigned ADHD presentation.
Results:Preliminary analyses revealed no significant group differences in age, education, race, or gender (ps > .05). An ANOVA indicated a significant difference between groups (F[1, 171] = 10.44, p = .001; Cohen’s d = .68) for Ds-ADHD raw scores; Veterans in the non-credible group reported more “erroneous stereotypes” of ADHD (M raw score = 13.33, SD = 2.20) than those in the credible group (M = 14.82, SD = 2.20). A ROC analysis indicated AUC of .691 (95% CI = .58 to .80). In addition, a cut score of <12 resulted in specificity of 91.8% and sensitivity of 18.5%, whereas a cut score of <13 resulted in specificity of 83.6% and sensitivity of 44.4%.
Conclusions:The Ds-ADHD scale demonstrated significant differences between credible and non-credible respondents in a real-world setting. Previously, this scale has primarily been studied within laboratory settings. Further, results indicate a cut score of <12 could be used in order to achieve adequate specificity (i.e., >90%), which were similar findings to a study examining SVT-based groups (Winiarski et al., 2023). These results differ slightly from prior research by Robinson and Rogers (2018), who indicated a cut score of <13 based on the initial simulation-based study. In similar clinical settings, where there are high rates of psychiatric comorbidity, a cut score of <12 may prove clinically useful. However, this cut-score was associated with low sensitivity within this mixed Veteran sample. Further research should focus on replicating findings within other clinical settings, including ones with larger non-credible samples.
16 Validation of the Pillbox Test in a Veteran Sample: A Replication Study.
- Frances M. Bozsik, Timothy J. Arentsen, Brad L. Roper, Jessica M. Fett, Marcy C. Adler, Jennifer L. Jacobson, Charlotte Bayer
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- Journal:
- Journal of the International Neuropsychological Society / Volume 29 / Issue s1 / November 2023
- Published online by Cambridge University Press:
- 21 December 2023, pp. 699-700
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Objective:
Assessment of medication management, an instrumental activity of daily living (IADL), is particularly important among Veterans, who are prescribed an average of 2540 prescriptions per year (Nguyen et al., 2017). The Pillbox Test (PT) is a brief, performance-based measure that was designed as an ecologically valid measure of executive functioning (EF; Zartman, Hilsabeck, Guarnaccia, & Houtz, 2013), the cognitive domain most predictive of successful medication schedule management (Suchy, Ziemnik, Niermeyer, & Brothers, 2020). However, a validation study by Logue, Marceaux, Balldin, and Hilsabeck (2015) found that EF predicted performance on the PT more so than processing speed (PS), but not the language, attention, visuospatial, and memory domains combined. Thus, this project sought to increase generalizability of the latter study by replicating and extending their investigation utilizing a larger set of neuropsychological tests.
Participants and Methods:Participants included 176 patients in a mixed clinical sample (5.1% female, 43.2% Black/African American, 55.7% white, Mage = 70.7 years, SDage = 9.3, Medu = 12.6 years, SDedu = 2.6) who completed a comprehensive neuropsychological evaluation in a VA medical center. All participants completed the PT where they had five minutes to organize five pill bottles using a seven-day pillbox according to standardized instructions on the labels. Participants also completed some combination of 26 neuropsychological tests (i.e., participants did not complete every test as evaluations were tailored to disparate referral questions). Correlations between completed tests and number of pillbox errors were evaluated. These tests were then combined into the following six domains: language, visuospatial, working memory (WM), psychomotor/PS, memory, and EF. Hierarchical multiple regression was completed using these domains to predict pillbox errors.
Results:Spearman’s correlation coefficients indicated that 25 tests had a weak to moderate relationship with PT total errors (rs = 0.23 -0.51); forward digit span was not significantly related (rs = 0.13). A forced-entry multiple regression was run to predict PT total errors from the six domains. The model accounted for 29% of the variance in PT performance, F(6, 169) = 11.56, p < .001. Of the domains, psychomotor/PS made the greatest contribution, f(169) = 2.73, p = .007, followed by language, f(169) = 2.41, p = .017, and WM, f(169) = 2.15, p = .033. Visuospatial performance and EF did not make significant contributions (ps>.05). Next, two hierarchical multiple regressions were run. Results indicated that EF predicted performance on the PT beyond measures of PS, AR2 = .02, p = .044, but not beyond the combination of all cognitive domains, AR2 = .00, p = .863.
Conclusions:Results of this study partially replicated the findings of Logue et al. (2015). Namely, EF predicted PT performance beyond PS, but not other cognitive domains. However, when all predictors were entered into the same model, visuospatial performance did not significantly contribute to the prediction of pillbox errors. These results suggest that providers may benefit from investigating medication management abilities when deficits in PS, WM, and/or language are identified. Further research is needed to better understand which domains best predict PT failure.
20 Clinical Utility of an Experimental Ds-ADHD Validity Scale in Detection of Feigned ADHD symptoms in a U.S. Military Population
- Holly R Winiarski, Timothy J Arentsen, Marcy C Adler, Christopher T Burley, Katie M Califano, Jennifer S Seeley-McGee, Brad L Roper
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- Journal:
- Journal of the International Neuropsychological Society / Volume 29 / Issue s1 / November 2023
- Published online by Cambridge University Press:
- 21 December 2023, p. 703
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Objective:
Accurate identification of Attention-Deficit/Hyperactivity Disorder (ADHD) is complicated by possible secondary gain, overlap of symptoms with psychiatric disorders, and face validity of measures (Suhr et al., 2011; Shura et al., 2017). To assist with diagnostic clarification, an experimental Dissimulation ADHD scale (Ds-ADHD; Robinson & Rogers, 2018) on the MMPI-2 was found to distinguish credible from non-credible respondents defined by Performance Validity Test (PVT)-based group assignment in Veterans (Burley et al., 2023). However, symptom and performance validity have been understood as unique constructs (Van Dyke et al., 2013), with Symptom Validity Tests (SVTs) more accurately identifying over-reporting of symptoms in ADHD (White et al., 2022). The current study sought to evaluate the effectiveness of the Ds-ADHD scale using an SVT, namely the Infrequency Index of CAARS (CII; Suhr et al., 2011), for group assignment within a mixed sample of Veterans.
Participants and Methods:In this retrospective study, 187 Veterans (Mage = 36.76, SDage = 11.25, Medu = 14.02, SDedu = 2.10, 83% male, 19% black, 78% white) were referred for neuropsychological evaluation of ADHD and administered a battery that included internally consistent MMPI-2 and CAARS profiles. Veterans were assigned to a credible group (n=134) if CII was <21 or a non-credible group (n=53) if CII was >21. The Ds-ADHD scale was calculated for the MMPI-2. Consistent with Robinson and Rogers (2018), “true” answers (i.e., erroneous stereotypes) were coded as 1 and “false” answers were coded as 2, creating a 10- to 20-point scale. Lower scores were associated with a higher likelihood of a feigned ADHD presentation.
Results:Analyses revealed no significant differences in age, education, race, or gender (ps > .05) between credible and non-credible groups. An ANOVA indicated a significant difference between groups (F[1,185] = 24.78, p <.001; Cohen’s d = 0.80) for Ds-ADHD raw scores. Veterans in the non-credible group reported more “erroneous stereotypes” of ADHD (M raw score = 13.23, SD = 2.10) than those in the credible group (M = 14.94, SD = 2.13). A ROC analysis indicated AUC of .72 (95% CI = .64 to .80). In addition, a Ds-ADHD cut score of <12 resulted in specificity of 94.5% and sensitivity of 22.6%, whereas a cut score of <13 resulted in specificity of 85.8% and sensitivity of 50.9%. When analyzing other CII cut scores recommended in the literature, results were essentially similar. Specifically, analyses were repeated when group assignment was defined by cut score of CII<18 and by removing an intermediate group (CII = 18 to 21; n=24).
Conclusions:The Ds-ADHD scale demonstrated significant differences between credible and non-credible respondents in a Veteran population. Results suggest a cut score of <12 had adequate specificity (.95) with low sensitivity (.23). This is consistent with findings using PVTs for group assignment that indicated a cut score of <12 had adequate specificity (.92) with low sensitivity (.19; Burley et al., 2023). Taken together, findings suggest that the Ds-ADHD scale demonstrates utility in the dissociation of credible from non-credible responding. Further research should evaluate the utility of the scale in other clinical populations.
31 The ADHD Dissimulation Scale (Ds- ADHD) on the MMPI-2-RF versus Established MMPI-2-RF Validity Scales
- Katie M Califano, Timothy J Arentsen, Holly R Winiarski, Christopher T Burley, Marcy C Adler, Jennifer S Seeley McGee, Brad L Roper
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- Journal:
- Journal of the International Neuropsychological Society / Volume 29 / Issue s1 / November 2023
- Published online by Cambridge University Press:
- 21 December 2023, pp. 712-713
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Objective:
The MMPI-2-RF contains scales that assess different types of invalid response styles, especially potential symptom over-reporting (e.g., F-r, Fs, Fp-r, FBS-r, RBS). However, these scales are not designed to specifically capture noncredible symptoms reports associated with Attention-Deficit/Hyperactivity Disorder (ADHD). Robinson & Rogers (2018) proposed the experimental Dissimulation ADHD validity scale (Ds-ADHD) on the MMPI-2-RF that was effective in distinguishing credible and non-credible ADHD diagnoses via a simulator-based study. Within the current study, the Ds-ADHD scale was compared to the established MMPI-2-RF validity scales within a mixed sample of U.S. Military Veterans.
Participants and Methods:173 Veterans (Mage = 36.18, SDage = 11.10, Medu = 14.01, SDedu = 2.11, 88% male, 81% White, 17% Black) completed a neuropsychological evaluation which included an internally consistent MMPI-2-RF profile and up to 10 performance validity tests (PVTs) as well as a question about a possible ADHD diagnosis. The credible group was determined if participants passed all PVTs (n=146) and completed at least 2 PVTs. The non-credible group was determined by failing two or more PVTs (n=27). Group assignment was clinically confirmed. The Ds-ADHD scale was calculated according to Robinson & Rogers’ (2018); responses of “true” (i.e., erroneous stereotypes) were coded as 1 and “false” answers were coded 2, creating a 10- to 20-point scale. Thus, lower scores would be associated with a higher likelihood of a feigned ADHD presentation. Other MMPI-2-RF validity scales of interest included F-r, Fs, Fp-r, FBS-r, and RBS.
Results:The established MMPI-2-RF validity scales were significantly correlated with PVT group membership, but correlations were weak to moderately strong (rS ranged from -.43 to -.18; ps < .05). A series of stepwise regression models were completed with the Ds-ADHD scale and one of the MMPI-2-RF validity scales as independent variables, with group membership as the dependent variable. Ds-ADHD) contributed uniquely to each model (CÜ ranged from .03 to .04, ps < .05). The established MMPI-2-RF validity scales effectively classified group membership (AUC values ranged from .57 to .68), and the Ds-ADHD scale had a marginally higher AUC (.69); however, it was not statistically significantly stronger than any of the established scales (ps > .05).
Conclusions:Clinicians interested in identifying potentially simulated ADHD presentations with the MMPI-2-RF may desire to calculate the Ds-ADHD scale, which previously only had support from a simulator-based study. The Ds-ADHD scale significantly contributed to each model, suggesting that it helped explain groups over and above each of the traditional MMPI-2-RF validity scales. However, it only had a marginally stronger ability to classify participants, indicating that there may be diminishing returns for clinicians. Among the traditional validity scales, RBS and F-r best classified groups, and FBS-r was the least effective. This study employed a cross-sectional design in a mixed sample of Veterans undergoing a neuropsychological evaluation. Future research should focus on replicating the findings using a credible sample that was limited to an independently verified diagnosis of ADHD.
84 Using a Combination Score from the Full Rey Complex Figure Test (RCFT) as a Performance Validity Measure (PVT)
- Jessica M. Fett, Timothy J. Arentsen, Brad L. Roper
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- Journal:
- Journal of the International Neuropsychological Society / Volume 29 / Issue s1 / November 2023
- Published online by Cambridge University Press:
- 21 December 2023, pp. 757-758
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Objective:
Some RCFT indices are effective Performance Validity Test (PVTs) during neuropsychological evaluations. A combination score that includes the copy score, true positive recognition, and atypical errors has proven to be especially useful (see Lu et al, 2003). However, this score was derived from administration that deviated from protocols outlined by Meyers & Meyers (1995) in that the Recognition trial was administered after the 3-minute delay instead of the 30-minute delay. The current study examined the utility of the RCFT combination score as a performance validity test (PVT) when completing the recognition trial after the 30-minute delay.
Participants and Methods:This study utilized archival data from 298 Veterans who presented for a clinical neuropsychological evaluation at a southern Veterans Affairs Medical Center. The evaluation included up to nine PVTs and all trials of the RCFT (per Meyers & Meyers, 1995). Patients were considered credible if all PVT performance fell within normal limits. This resulted in 232 patients in the credible group (Mage = 52.9 years, SDage = 15.2, Medu = SDedu = 2.5, 88% male, 71.2% White, 28.3% Black/African American). Patients were considered non-credible if they failed >2 PVTs. This resulted in 66 patients in the non-credible group (Mage = 51.6, SDage = 13.79, Medu = SDedu = 2.4, 92.4% male, 56.1% White, 43.9% Black/African American). Group assignment was also clinically confirmed. Receiver operating characteristic (ROC) curve analyses were conducted to discriminate between credible and non-credible groups utilizing the established RCFT combination score.
Results:RCFT combination scores distinguished groups, with credible participants scoring higher than non-credible participants (F[1, 296]=63.76, p<.001, d=1.11; M = 56.9, SD = 9.3 vs. M = 46.5, SD = 9.5, respectively). A ROC analysis indicated AUC = .800 (95% CI = .73 to .86). When specificity was set at >90%, a cut-score of <46.5 yielded sensitivity at 46.0%. The analogous cut-score from the Lu et al. (2003) study (i.e., <47) was associated with a specificity of 88.7 and sensitivity of 46.0% in the current study.
Conclusions:As the Lu et al. (2003) established the combination score of the RCFT with procedures that deviated from the standardized protocol outlined by Meyers and Meyers (1995), clinicians who opted to adhere to Meyers and Meyers’ full protocol may have concerns about using the combination score as a PVT. The current study established a similar cut-off score to what Lu et al., (2003) reported (i.e., <46.5 vs. <47) while following a different administration procedure of the RCFT. Also, the index was moderately sensitive in the current study (i.e., 45.5%) but less so than what Lu et al. reported when using a cut-score that had >90% specificity (i.e., 75.9% sensitivity). This suggests that the index may be robust to deviations in administration procedures. Difference in sensitivity could be related to difference between samples. As the current sample was derived from a clinical, VA setting, current findings extend the generalizability of the index. Future research would benefit exploring if any subgroups would benefit from adjusted cut-scores to reduce the risk of false positive identification.
Bipolar disorder, cycloid psychosis and schizophrenia: a study using “lifetime” psychopathology ratings, factor analysis and canonical variate analysis
- IF Brockington, A Roper, M Buckley, J Copas, C Andrade, P Wigg, A Farmer, C Kaufman, R Hawley, HY Meltzer
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- European Psychiatry / Volume 6 / Issue 5 / 1991
- Published online by Cambridge University Press:
- 16 April 2020, pp. 223-236
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In an empirical study on the classification of the psychoses, 302 patients were rated using the Longitudinal Psychopathology Schedule. The data were condensed by factor analysis, which yielded 10 factors - mania and schizomania, depression and suicidal activity, and 6 factors concerned with psychotic symptoms (verbal hallucinosis/passivity, delusion formation, defect symptoms, social decline, cycloid symptomatology and a factor loading depressive auditory hallucinations and visual hallucinations). Provisional diagnostic groups were obtained using DSM III. Discriminant function analyses showed that the only clearly distinct diagnostic group was bipolar disorder, and this was true for various definitions. Canonical variate analyses were performed using 3- and 4-criterion groups. These showed that a group corresponding approximately to cycloid psychosis also met criteria for being a distinct group. The most detailed examination pf the data, using 4-criterion groups and serial reclassification, suggested that the psychoses might fall into 5 groups - bipolar disorder, cycloid psychosis, depression, defect states and schizoaffective depression.
A Multi-Frequency Study of the Milky Way-Like Spiral Galaxy NGC 6744
- Miranda Yew, Miroslav D. Filipović, Quentin Roper, Jordan D. Collier, Evan J. Crawford, Thomas H. Jarrett, Nicholas F. H. Tothill, Andrew N. O’Brien, Marko Z. Pavlović, Thomas G. Pannuti, Timothy J. Galvin, Anna D. Kapińska, Michelle E. Cluver, Julie K. Banfield, Eric M. Schlegel, Nigel Maxted, Kevin R. Grieve
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- Journal:
- Publications of the Astronomical Society of Australia / Volume 35 / 2018
- Published online by Cambridge University Press:
- 28 March 2018, e015
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We present a multi-frequency study of the intermediate spiral SAB(r)bc type galaxy NGC 6744, using available data from the Chandra X-Ray telescope, radio continuum data from the Australia Telescope Compact Array and Murchison Widefield Array, and Wide-field Infrared Survey Explorer infrared observations. We identify 117 X-ray sources and 280 radio sources. Of these, we find nine sources in common between the X-ray and radio catalogues, one of which is a faint central black hole with a bolometric radio luminosity similar to the Milky Way’s central black hole. We classify 5 objects as supernova remnant (SNR) candidates, 2 objects as likely SNRs, 17 as H ii regions, 1 source as an AGN; the remaining 255 radio sources are categorised as background objects and one X-ray source is classified as a foreground star. We find the star-formation rate (SFR) of NGC 6744 to be in the range 2.8–4.7 M⊙~yr − 1 signifying the galaxy is still actively forming stars. The specific SFR of NGC 6744 is greater than that of late-type spirals such as the Milky Way, but considerably less that that of a typical starburst galaxy.
Monolayer-enriched production of Au-decorated WS2 Nanosheets via Defect Engineering
- Jeremy R. Dunklin, Paul Lafargue, Thomas M. Higgins, Gregory T. Forcherio, Mourad Benamara, Niall McEvoy, D. Keith Roper, Jonathan N. Coleman, Yana Vaynzof, Claudia Backes
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- Journal:
- MRS Advances / Volume 3 / Issue 41 / 2018
- Published online by Cambridge University Press:
- 06 April 2018, pp. 2435-2440
- Print publication:
- 2018
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Layered transition metal dichalcogenides (TMDs) represent a diverse, emerging source of two-dimensional (2D) nanostructures with broad application in optoelectronics and energy. Chemical functionalization has evolved into a powerful tool to tailor properties of these 2D TMDs; however, functionalization strategies have been largely limited to the metallic 1T-polytype. The work herein illustrates that 2H-semiconducting liquid-exfoliated tungsten disulfide (WS2) undergoes a spontaneous redox reaction with gold (III) chloride (AuCl3). Au nanoparticles (NPs) predominantly nucleate at nanosheet edges with tuneable NP size and density. AuCl3 is preferentially reduced on multi-layer WS2 and resulting large Au aggregates are easily separated from the colloidal dispersion by simple centrifugation. This process may be exploited to enrich the dispersions in laterally large, monolayer nanosheets. It is proposed that thiol groups at edges and defects sides reduce the AuCl3 to Au0 and are in turn oxidized to disulfides. Optical emission, i.e. photoluminescence, of the monolayers remained pristine, while the electrocatalytic activity towards the hydrogen evolution reaction is significantly improved. Taken together, these improvements in functionalization, fabrication, and catalytic activity represent an important advance in the study of these emerging 2D nanostructures.
Integrating CFD and piloted simulation to quantify ship-helicopter operating limits
- D. M. Roper, I. Owen, G. D. Padfield, S. J. Hodge
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- The Aeronautical Journal / Volume 110 / Issue 1109 / July 2006
- Published online by Cambridge University Press:
- 03 February 2016, pp. 419-428
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This paper describes a study which has been concerned with numerical predictions of the airwakes resulting from two simplified ship geometries: the internationally agreed Simple Frigate Shape, SFS1, and its successor, SFS2. Extensive steady-state simulations have been carried out for a wide range of wind conditions using Fluent, a commercially available Computational Fluid Dynamics (CFD) code. The CFD predictions have been partially validated against wind tunnel data produced by the National Research Council of Canada (NRC) and have shown good agreement. The resulting airwake velocity components have been exported from Fluent, interpolated onto suitable grids and attached to the FLIGHTLAB flight-simulation environment as look-up tables; piloted flight trials were then carried out using the Liverpool full-motion simulator. The pilot workload and helicopter control margins resulting from a range of wind-over-deck conditions have been used to develop the Ship-Helicopter Operating Limits (SHOL) for a Lynx-like helicopter and the SFS2. The workload was compared to the pilot’s experiences on a similar aircraft and a Type 23 Frigate and the simulated SHOL compared with SHOLs derived from sea trials. The results are very encouraging and open up further the long awaited prospect of such simulations being used in the future to reduce at-sea trials, and to provide a safe environment for pilot training.
Bone-anchored hearing aids and chronic pain: a long-term complication and a cause for elective implant removal
- D Siau, H Nik, J C Hobson, A J Roper, M P Rothera, K M J Green
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- Journal:
- The Journal of Laryngology & Otology / Volume 126 / Issue 5 / May 2012
- Published online by Cambridge University Press:
- 03 April 2012, pp. 445-449
- Print publication:
- May 2012
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Objectives:
To report a case series of elective removal of bone-anchored hearing aid implants, and reasons for removal.
Design:Retrospective review of a prospectively collected database.
Setting:Two tertiary referral centres in the Manchester area: Manchester Royal Infirmary and Salford Royal University Hospital.
Participants:A series of 499 adults and children who had undergone a total of 602 implant insertions (1984–2008).
Main outcome measures:Implant removal rates, and reasons.
Results:Twenty-seven of the 602 implants (4.5 per cent) required removal. Of these, 12 were due to pain (2.0 per cent), seven to persistent infection (1.2 per cent), three to failure of osseointegration (0.5 per cent), three to trauma (0.5 per cent) and two to other reasons (0.4 per cent).
Conclusion:Chronic implant site pain represents the main reason why implants are removed electively, and affects 2 per cent of all implants. This complication has important medico-legal implications and should be discussed when obtaining informed consent for implantation.
Localisation of convection in mushy layers by weak background flow
- S. M. ROPER, S. H. DAVIS, P. W. VOORHEES
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- Journal of Fluid Mechanics / Volume 675 / 25 May 2011
- Published online by Cambridge University Press:
- 11 May 2011, pp. 518-528
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It is known that freckles form at the sidewalls of directionally solidified materials. We present a weakly nonlinear analysis of the effects of a weak and slowly varying background flow formed by non-axial thermal gradients on convection near onset in a mushy layer. We find that in the two-dimensional case, the onset of mush convection occurs away from the walls. However if three-dimensional disturbances are allowed, the onset occurs near the walls of the container confining the mush. We derive amplitude equations governing this behaviour and simulate their evolution numerically.
Coblation of rhinophyma
- M Timms, A Roper, C Patrick
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- Journal:
- The Journal of Laryngology & Otology / Volume 125 / Issue 7 / July 2011
- Published online by Cambridge University Press:
- 27 April 2011, pp. 724-728
- Print publication:
- July 2011
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Introduction:
Rhinophyma is a disfiguring hypertrophy of the skin of the tip of the nose.
Objective:To assess the new technique of coblation of rhinophyma.
Study design:Case series of six patients.
Results:All patients had a good cosmetic result. Comparison with existing techniques showed advantages due to the lower tissue temperature involved.
Conclusion:Coblation of rhinophyma is an effective treatment with few side effects.
Contributors
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- By Rose Teteki Abbey, K. C. Abraham, David Tuesday Adamo, LeRoy H. Aden, Efrain Agosto, Victor Aguilan, Gillian T. W. Ahlgren, Charanjit Kaur AjitSingh, Dorothy B E A Akoto, Giuseppe Alberigo, Daniel E. Albrecht, Ruth Albrecht, Daniel O. Aleshire, Urs Altermatt, Anand Amaladass, Michael Amaladoss, James N. Amanze, Lesley G. Anderson, Thomas C. Anderson, Victor Anderson, Hope S. Antone, María Pilar Aquino, Paula Arai, Victorio Araya Guillén, S. Wesley Ariarajah, Ellen T. Armour, Brett Gregory Armstrong, Atsuhiro Asano, Naim Stifan Ateek, Mahmoud Ayoub, John Alembillah Azumah, Mercedes L. García Bachmann, Irena Backus, J. Wayne Baker, Mieke Bal, Lewis V. Baldwin, William Barbieri, António Barbosa da Silva, David Basinger, Bolaji Olukemi Bateye, Oswald Bayer, Daniel H. Bays, Rosalie Beck, Nancy Elizabeth Bedford, Guy-Thomas Bedouelle, Chorbishop Seely Beggiani, Wolfgang Behringer, Christopher M. Bellitto, Byard Bennett, Harold V. Bennett, Teresa Berger, Miguel A. Bernad, Henley Bernard, Alan E. Bernstein, Jon L. Berquist, Johannes Beutler, Ana María Bidegain, Matthew P. Binkewicz, Jennifer Bird, Joseph Blenkinsopp, Dmytro Bondarenko, Paulo Bonfatti, Riet en Pim Bons-Storm, Jessica A. Boon, Marcus J. Borg, Mark Bosco, Peter C. Bouteneff, François Bovon, William D. Bowman, Paul S. Boyer, David Brakke, Richard E. Brantley, Marcus Braybrooke, Ian Breward, Ênio José da Costa Brito, Jewel Spears Brooker, Johannes Brosseder, Nicholas Canfield Read Brown, Robert F. Brown, Pamela K. Brubaker, Walter Brueggemann, Bishop Colin O. Buchanan, Stanley M. Burgess, Amy Nelson Burnett, J. Patout Burns, David B. Burrell, David Buttrick, James P. Byrd, Lavinia Byrne, Gerado Caetano, Marcos Caldas, Alkiviadis Calivas, William J. Callahan, Salvatore Calomino, Euan K. Cameron, William S. Campbell, Marcelo Ayres Camurça, Daniel F. Caner, Paul E. Capetz, Carlos F. Cardoza-Orlandi, Patrick W. Carey, Barbara Carvill, Hal Cauthron, Subhadra Mitra Channa, Mark D. Chapman, James H. Charlesworth, Kenneth R. Chase, Chen Zemin, Luciano Chianeque, Philip Chia Phin Yin, Francisca H. Chimhanda, Daniel Chiquete, John T. Chirban, Soobin Choi, Robert Choquette, Mita Choudhury, Gerald Christianson, John Chryssavgis, Sejong Chun, Esther Chung-Kim, Charles M. A. Clark, Elizabeth A. Clark, Sathianathan Clarke, Fred Cloud, John B. Cobb, W. Owen Cole, John A Coleman, John J. Collins, Sylvia Collins-Mayo, Paul K. Conkin, Beth A. Conklin, Sean Connolly, Demetrios J. Constantelos, Michael A. Conway, Paula M. Cooey, Austin Cooper, Michael L. Cooper-White, Pamela Cooper-White, L. William Countryman, Sérgio Coutinho, Pamela Couture, Shannon Craigo-Snell, James L. Crenshaw, David Crowner, Humberto Horacio Cucchetti, Lawrence S. Cunningham, Elizabeth Mason Currier, Emmanuel Cutrone, Mary L. Daniel, David D. Daniels, Robert Darden, Rolf Darge, Isaiah Dau, Jeffry C. Davis, Jane Dawson, Valentin Dedji, John W. de Gruchy, Paul DeHart, Wendy J. Deichmann Edwards, Miguel A. De La Torre, George E. Demacopoulos, Thomas de Mayo, Leah DeVun, Beatriz de Vasconcellos Dias, Dennis C. Dickerson, John M. Dillon, Luis Miguel Donatello, Igor Dorfmann-Lazarev, Susanna Drake, Jonathan A. Draper, N. Dreher Martin, Otto Dreydoppel, Angelyn Dries, A. J. Droge, Francis X. D'Sa, Marilyn Dunn, Nicole Wilkinson Duran, Rifaat Ebied, Mark J. Edwards, William H. Edwards, Leonard H. Ehrlich, Nancy L. Eiesland, Martin Elbel, J. Harold Ellens, Stephen Ellingson, Marvin M. Ellison, Robert Ellsberg, Jean Bethke Elshtain, Eldon Jay Epp, Peter C. Erb, Tassilo Erhardt, Maria Erling, Noel Leo Erskine, Gillian R. Evans, Virginia Fabella, Michael A. Fahey, Edward Farley, Margaret A. Farley, Wendy Farley, Robert Fastiggi, Seena Fazel, Duncan S. Ferguson, Helwar Figueroa, Paul Corby Finney, Kyriaki Karidoyanes FitzGerald, Thomas E. FitzGerald, John R. Fitzmier, Marie Therese Flanagan, Sabina Flanagan, Claude Flipo, Ronald B. Flowers, Carole Fontaine, David Ford, Mary Ford, Stephanie A. Ford, Jim Forest, William Franke, Robert M. Franklin, Ruth Franzén, Edward H. Friedman, Samuel Frouisou, Lorelei F. Fuchs, Jojo M. Fung, Inger Furseth, Richard R. Gaillardetz, Brandon Gallaher, China Galland, Mark Galli, Ismael García, Tharscisse Gatwa, Jean-Marie Gaudeul, Luis María Gavilanes del Castillo, Pavel L. Gavrilyuk, Volney P. Gay, Metropolitan Athanasios Geevargis, Kondothra M. George, Mary Gerhart, Simon Gikandi, Maurice Gilbert, Michael J. Gillgannon, Verónica Giménez Beliveau, Terryl Givens, Beth Glazier-McDonald, Philip Gleason, Menghun Goh, Brian Golding, Bishop Hilario M. Gomez, Michelle A. Gonzalez, Donald K. Gorrell, Roy Gottfried, Tamara Grdzelidze, Joel B. Green, Niels Henrik Gregersen, Cristina Grenholm, Herbert Griffiths, Eric W. Gritsch, Erich S. Gruen, Christoffer H. Grundmann, Paul H. Gundani, Jon P. Gunnemann, Petre Guran, Vidar L. Haanes, Jeremiah M. Hackett, Getatchew Haile, Douglas John Hall, Nicholas Hammond, Daphne Hampson, Jehu J. Hanciles, Barry Hankins, Jennifer Haraguchi, Stanley S. Harakas, Anthony John Harding, Conrad L. Harkins, J. William Harmless, Marjory Harper, Amir Harrak, Joel F. Harrington, Mark W. Harris, Susan Ashbrook Harvey, Van A. Harvey, R. Chris Hassel, Jione Havea, Daniel Hawk, Diana L. Hayes, Leslie Hayes, Priscilla Hayner, S. Mark Heim, Simo Heininen, Richard P. Heitzenrater, Eila Helander, David Hempton, Scott H. Hendrix, Jan-Olav Henriksen, Gina Hens-Piazza, Carter Heyward, Nicholas J. Higham, David Hilliard, Norman A. Hjelm, Peter C. Hodgson, Arthur Holder, M. Jan Holton, Dwight N. Hopkins, Ronnie Po-chia Hsia, Po-Ho Huang, James Hudnut-Beumler, Jennifer S. Hughes, Leonard M. Hummel, Mary E. Hunt, Laennec Hurbon, Mark Hutchinson, Susan E. Hylen, Mary Beth Ingham, H. Larry Ingle, Dale T. Irvin, Jon Isaak, Paul John Isaak, Ada María Isasi-Díaz, Hans Raun Iversen, Margaret C. Jacob, Arthur James, Maria Jansdotter-Samuelsson, David Jasper, Werner G. Jeanrond, Renée Jeffery, David Lyle Jeffrey, Theodore W. Jennings, David H. Jensen, Robin Margaret Jensen, David Jobling, Dale A. Johnson, Elizabeth A. Johnson, Maxwell E. Johnson, Sarah Johnson, Mark D. Johnston, F. Stanley Jones, James William Jones, John R. Jones, Alissa Jones Nelson, Inge Jonsson, Jan Joosten, Elizabeth Judd, Mulambya Peggy Kabonde, Robert Kaggwa, Sylvester Kahakwa, Isaac Kalimi, Ogbu U. Kalu, Eunice Kamaara, Wayne C. Kannaday, Musimbi Kanyoro, Veli-Matti Kärkkäinen, Frank Kaufmann, Léon Nguapitshi Kayongo, Richard Kearney, Alice A. Keefe, Ralph Keen, Catherine Keller, Anthony J. Kelly, Karen Kennelly, Kathi Lynn Kern, Fergus Kerr, Edward Kessler, George Kilcourse, Heup Young Kim, Kim Sung-Hae, Kim Yong-Bock, Kim Yung Suk, Richard King, Thomas M. King, Robert M. Kingdon, Ross Kinsler, Hans G. Kippenberg, Cheryl A. Kirk-Duggan, Clifton Kirkpatrick, Leonid Kishkovsky, Nadieszda Kizenko, Jeffrey Klaiber, Hans-Josef Klauck, Sidney Knight, Samuel Kobia, Robert Kolb, Karla Ann Koll, Heikki Kotila, Donald Kraybill, Philip D. W. Krey, Yves Krumenacker, Jeffrey Kah-Jin Kuan, Simanga R. Kumalo, Peter Kuzmic, Simon Shui-Man Kwan, Kwok Pui-lan, André LaCocque, Stephen E. Lahey, John Tsz Pang Lai, Emiel Lamberts, Armando Lampe, Craig Lampe, Beverly J. Lanzetta, Eve LaPlante, Lizette Larson-Miller, Ariel Bybee Laughton, Leonard Lawlor, Bentley Layton, Robin A. Leaver, Karen Lebacqz, Archie Chi Chung Lee, Marilyn J. Legge, Hervé LeGrand, D. L. LeMahieu, Raymond Lemieux, Bill J. Leonard, Ellen M. Leonard, Outi Leppä, Jean Lesaulnier, Nantawan Boonprasat Lewis, Henrietta Leyser, Alexei Lidov, Bernard Lightman, Paul Chang-Ha Lim, Carter Lindberg, Mark R. Lindsay, James R. Linville, James C. Livingston, Ann Loades, David Loades, Jean-Claude Loba-Mkole, Lo Lung Kwong, Wati Longchar, Eleazar López, David W. Lotz, Andrew Louth, Robin W. Lovin, William Luis, Frank D. Macchia, Diarmaid N. J. MacCulloch, Kirk R. MacGregor, Marjory A. MacLean, Donald MacLeod, Tomas S. Maddela, Inge Mager, Laurenti Magesa, David G. Maillu, Fortunato Mallimaci, Philip Mamalakis, Kä Mana, Ukachukwu Chris Manus, Herbert Robinson Marbury, Reuel Norman Marigza, Jacqueline Mariña, Antti Marjanen, Luiz C. L. Marques, Madipoane Masenya (ngwan'a Mphahlele), Caleb J. D. Maskell, Steve Mason, Thomas Massaro, Fernando Matamoros Ponce, András Máté-Tóth, Odair Pedroso Mateus, Dinis Matsolo, Fumitaka Matsuoka, John D'Arcy May, Yelena Mazour-Matusevich, Theodore Mbazumutima, John S. McClure, Christian McConnell, Lee Martin McDonald, Gary B. McGee, Thomas McGowan, Alister E. McGrath, Richard J. McGregor, John A. McGuckin, Maud Burnett McInerney, Elsie Anne McKee, Mary B. McKinley, James F. McMillan, Ernan McMullin, Kathleen E. McVey, M. Douglas Meeks, Monica Jyotsna Melanchthon, Ilie Melniciuc-Puica, Everett Mendoza, Raymond A. Mentzer, William W. Menzies, Ina Merdjanova, Franziska Metzger, Constant J. Mews, Marvin Meyer, Carol Meyers, Vasile Mihoc, Gunner Bjerg Mikkelsen, Maria Inêz de Castro Millen, Clyde Lee Miller, Bonnie J. Miller-McLemore, Alexander Mirkovic, Paul Misner, Nozomu Miyahira, R. W. L. Moberly, Gerald Moede, Aloo Osotsi Mojola, Sunanda Mongia, Rebeca Montemayor, James Moore, Roger E. Moore, Craig E. Morrison O.Carm, Jeffry H. Morrison, Keith Morrison, Wilson J. Moses, Tefetso Henry Mothibe, Mokgethi Motlhabi, Fulata Moyo, Henry Mugabe, Jesse Ndwiga Kanyua Mugambi, Peggy Mulambya-Kabonde, Robert Bruce Mullin, Pamela Mullins Reaves, Saskia Murk Jansen, Heleen L. Murre-Van den Berg, Augustine Musopole, Isaac M. T. Mwase, Philomena Mwaura, Cecilia Nahnfeldt, Anne Nasimiyu Wasike, Carmiña Navia Velasco, Thulani Ndlazi, Alexander Negrov, James B. Nelson, David G. Newcombe, Carol Newsom, Helen J. Nicholson, George W. E. Nickelsburg, Tatyana Nikolskaya, Damayanthi M. A. Niles, Bertil Nilsson, Nyambura Njoroge, Fidelis Nkomazana, Mary Beth Norton, Christian Nottmeier, Sonene Nyawo, Anthère Nzabatsinda, Edward T. Oakes, Gerald O'Collins, Daniel O'Connell, David W. Odell-Scott, Mercy Amba Oduyoye, Kathleen O'Grady, Oyeronke Olajubu, Thomas O'Loughlin, Dennis T. Olson, J. Steven O'Malley, Cephas N. Omenyo, Muriel Orevillo-Montenegro, César Augusto Ornellas Ramos, Agbonkhianmeghe E. Orobator, Kenan B. Osborne, Carolyn Osiek, Javier Otaola Montagne, Douglas F. Ottati, Anna May Say Pa, Irina Paert, Jerry G. Pankhurst, Aristotle Papanikolaou, Samuele F. Pardini, Stefano Parenti, Peter Paris, Sung Bae Park, Cristián G. Parker, Raquel Pastor, Joseph Pathrapankal, Daniel Patte, W. Brown Patterson, Clive Pearson, Keith F. Pecklers, Nancy Cardoso Pereira, David Horace Perkins, Pheme Perkins, Edward N. Peters, Rebecca Todd Peters, Bishop Yeznik Petrossian, Raymond Pfister, Peter C. Phan, Isabel Apawo Phiri, William S. F. Pickering, Derrick G. Pitard, William Elvis Plata, Zlatko Plese, John Plummer, James Newton Poling, Ronald Popivchak, Andrew Porter, Ute Possekel, James M. Powell, Enos Das Pradhan, Devadasan Premnath, Jaime Adrían Prieto Valladares, Anne Primavesi, Randall Prior, María Alicia Puente Lutteroth, Eduardo Guzmão Quadros, Albert Rabil, Laurent William Ramambason, Apolonio M. Ranche, Vololona Randriamanantena Andriamitandrina, Lawrence R. Rast, Paul L. Redditt, Adele Reinhartz, Rolf Rendtorff, Pål Repstad, James N. Rhodes, John K. Riches, Joerg Rieger, Sharon H. Ringe, Sandra Rios, Tyler Roberts, David M. Robinson, James M. Robinson, Joanne Maguire Robinson, Richard A. H. Robinson, Roy R. Robson, Jack B. Rogers, Maria Roginska, Sidney Rooy, Rev. Garnett Roper, Maria José Fontelas Rosado-Nunes, Andrew C. Ross, Stefan Rossbach, François Rossier, John D. Roth, John K. Roth, Phillip Rothwell, Richard E. Rubenstein, Rosemary Radford Ruether, Markku Ruotsila, John E. Rybolt, Risto Saarinen, John Saillant, Juan Sanchez, Wagner Lopes Sanchez, Hugo N. Santos, Gerhard Sauter, Gloria L. Schaab, Sandra M. Schneiders, Quentin J. Schultze, Fernando F. Segovia, Turid Karlsen Seim, Carsten Selch Jensen, Alan P. F. Sell, Frank C. Senn, Kent Davis Sensenig, Damían Setton, Bal Krishna Sharma, Carolyn J. Sharp, Thomas Sheehan, N. Gerald Shenk, Christian Sheppard, Charles Sherlock, Tabona Shoko, Walter B. Shurden, Marguerite Shuster, B. Mark Sietsema, Batara Sihombing, Neil Silberman, Clodomiro Siller, Samuel Silva-Gotay, Heikki Silvet, John K. Simmons, Hagith Sivan, James C. Skedros, Abraham Smith, Ashley A. Smith, Ted A. Smith, Daud Soesilo, Pia Søltoft, Choan-Seng (C. S.) Song, Kathryn Spink, Bryan Spinks, Eric O. Springsted, Nicolas Standaert, Brian Stanley, Glen H. Stassen, Karel Steenbrink, Stephen J. Stein, Andrea Sterk, Gregory E. Sterling, Columba Stewart, Jacques Stewart, Robert B. Stewart, Cynthia Stokes Brown, Ken Stone, Anne Stott, Elizabeth Stuart, Monya Stubbs, Marjorie Hewitt Suchocki, David Kwang-sun Suh, Scott W. Sunquist, Keith Suter, Douglas Sweeney, Charles H. Talbert, Shawqi N. Talia, Elsa Tamez, Joseph B. Tamney, Jonathan Y. Tan, Yak-Hwee Tan, Kathryn Tanner, Feiya Tao, Elizabeth S. Tapia, Aquiline Tarimo, Claire Taylor, Mark Lewis Taylor, Bishop Abba Samuel Wolde Tekestebirhan, Eugene TeSelle, M. Thomas Thangaraj, David R. Thomas, Andrew Thornley, Scott Thumma, Marcelo Timotheo da Costa, George E. “Tink” Tinker, Ola Tjørhom, Karen Jo Torjesen, Iain R. Torrance, Fernando Torres-Londoño, Archbishop Demetrios [Trakatellis], Marit Trelstad, Christine Trevett, Phyllis Trible, Johannes Tromp, Paul Turner, Robert G. Tuttle, Archbishop Desmond Tutu, Peter Tyler, Anders Tyrberg, Justin Ukpong, Javier Ulloa, Camillus Umoh, Kristi Upson-Saia, Martina Urban, Monica Uribe, Elochukwu Eugene Uzukwu, Richard Vaggione, Gabriel Vahanian, Paul Valliere, T. J. Van Bavel, Steven Vanderputten, Peter Van der Veer, Huub Van de Sandt, Louis Van Tongeren, Luke A. Veronis, Noel Villalba, Ramón Vinke, Tim Vivian, David Voas, Elena Volkova, Katharina von Kellenbach, Elina Vuola, Timothy Wadkins, Elaine M. Wainwright, Randi Jones Walker, Dewey D. Wallace, Jerry Walls, Michael J. Walsh, Philip Walters, Janet Walton, Jonathan L. Walton, Wang Xiaochao, Patricia A. Ward, David Harrington Watt, Herold D. Weiss, Laurence L. Welborn, Sharon D. Welch, Timothy Wengert, Traci C. West, Merold Westphal, David Wetherell, Barbara Wheeler, Carolinne White, Jean-Paul Wiest, Frans Wijsen, Terry L. Wilder, Felix Wilfred, Rebecca Wilkin, Daniel H. Williams, D. Newell Williams, Michael A. Williams, Vincent L. Wimbush, Gabriele Winkler, Anders Winroth, Lauri Emílio Wirth, James A. Wiseman, Ebba Witt-Brattström, Teofil Wojciechowski, John Wolffe, Kenman L. Wong, Wong Wai Ching, Linda Woodhead, Wendy M. Wright, Rose Wu, Keith E. Yandell, Gale A. Yee, Viktor Yelensky, Yeo Khiok-Khng, Gustav K. K. Yeung, Angela Yiu, Amos Yong, Yong Ting Jin, You Bin, Youhanna Nessim Youssef, Eliana Yunes, Robert Michael Zaller, Valarie H. Ziegler, Barbara Brown Zikmund, Joyce Ann Zimmerman, Aurora Zlotnik, Zhuo Xinping
- Edited by Daniel Patte, Vanderbilt University, Tennessee
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- Book:
- The Cambridge Dictionary of Christianity
- Published online:
- 05 August 2012
- Print publication:
- 20 September 2010, pp xi-xliv
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Complications of bone-anchored hearing aid implantation
- J C Hobson, A J Roper, R Andrew, M P Rothera, P Hill, K M Green
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- Journal:
- The Journal of Laryngology & Otology / Volume 124 / Issue 2 / February 2010
- Published online by Cambridge University Press:
- 08 December 2009, pp. 132-136
- Print publication:
- February 2010
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Introduction:
Bone-anchored hearing aid implantations have been performed in Manchester for over 20 years. This study examined a range of variables that can occur during the implantation process, and the effect they may have on successful outcome.
Method:Retrospective study and literature review.
Location:Tertiary referral centre in central Manchester.
Results:Details of 602 bone-anchored hearing aid implantation procedures were retrieved from the departmental database. The overall complication rate was 23.9 per cent. The rate of revision surgery was 12.1 per cent.
Conclusion:This study involved a significantly larger number of patients than any previously reported, similar study. Possible reasons for differences in outcomes, and recommendations for best practice, are discussed.
The thinning of lamellae in surfactant-free foams with non-Newtonian liquid phase
- L. N. BRUSH, S. M. ROPER
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- Journal:
- Journal of Fluid Mechanics / Volume 616 / 10 December 2008
- Published online by Cambridge University Press:
- 10 December 2008, pp. 235-262
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Thinning rates of liquid lamellae in surfactant-free non-Newtonian gas–liquid foams, appropriate for ceramic or polymer melts and also in metals near the melting point, are derived in two dimensions by matched asymptotic analysis valid at small capillary number. The liquid viscosity is modelled (i) as a power-law function of the shear rate and (ii) by the Ellis law. Equations governing gas–liquid interface dynamics and variations in liquid viscosity are derived within the lamellar, transition and plateau border regions of a corner of the liquid surrounding a gas bubble. The results show that the viscosity varies primarily in the very short transition region lying between the lamellar and the Plateau border regions where the shear rates can become very large. In contrast to a foam with Newtonian liquid, the matching condition which determines the rate of lamellar thinning is non-local. In all cases considered, calculated lamellar thinning rates exhibit an initial transient thinning regime, followed by a t−2 power-law thinning regime, similar to the behaviour seen in foams with Newtonian liquid phase. In semi-arid foam, in which the liquid fraction is O(1) in the small capillary number, results explicitly show that for both the power-law and Ellis-law model of viscosity, the thinning of lamella in non-Newtonian and Newtonian foams is governed by the same equation, from which scaling laws can be deduced. This result is consistent with recently published experimental results on forced foam drainage. However, in an arid foam, which has much smaller volume fraction of liquid resulting in an increase in the Plateau border radius of curvature as lamellar thinning progresses, the scaling law depends on the material and the thinning rate is not independent of the liquid viscosity model parameters. Calculations of thinning rates, viscosities, pressures, interface shapes and shear rates in the transition region are presented using data for real liquids from the literature. Although for shear-thinning fluids the power-law viscosity becomes infinite at the boundaries of the internal transition region where the shear rate is zero, the interface shape, the pressure and the internal shear rates calculated by both rheological models are indistinguishable.
6 - Structure and evolution of fern plastid genomes
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- By Paul G. Wolf, Department of Biology, Utah State University, Logan, UT 84322, USA, Jessie M. Roper, Department of Biology, Utah State University, Logan, UT 84322, USA
- Edited by Tom A. Ranker, University of Colorado, Boulder, Christopher H. Haufler, University of Kansas
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- Book:
- Biology and Evolution of Ferns and Lycophytes
- Published online:
- 11 August 2009
- Print publication:
- 19 June 2008, pp 159-174
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Summary
Introduction
The concept of the genome, as the haploid complement of genes of an organism, is far from recent. The term genome is usually attributed to Hans Winkler in 1920 (Ledergerg and McCray, 2001). However, fine scale maps and understanding of the function of genes in the context of the genome did not begin until the 1970s after DNA sequencing techniques were developed. The term genome (and its corresponding genomics) can mean different things to different people (Ledergerg and McCray, 2001) but here we will focus on structural and evolutionary aspects of genomes in ferns. Although genomics is generally reserved for the main (nuclear) component of an organism, that topic is covered in Chapter 7. Instead we narrow the focus here to the chloroplast (i.e., plastid) genome. This small, well-defined genome is found in all green plants. Among land plants the plastid genome is highly conserved in structure and gene content (Palmer, 1985b). Compared to most nuclear genomes studied, plastid genomes contain a high proportion of DNA that codes for proteins and for RNA (ribosomal and transfer). Much of the non-coding regions (between protein-encoding genes) is transcribed and may well have important regulatory functions.
Because the plastid genome contains a high density of genes of well-studied processes, the genome is an excellent model for investigations into the relationship between genome structure and function. This field represents an ideal starting point leading into the much more complex field of the study of nuclear genomes.
An analysis of convection in a mushy layer with a deformable permeable interface
- S. M. ROPER, S. H. DAVIS, P. W. VOORHEES
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- Journal:
- Journal of Fluid Mechanics / Volume 596 / 25 January 2008
- Published online by Cambridge University Press:
- 17 January 2008, pp. 333-352
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We study the dynamics of a mushy layer in directional solidification for the case of a thin near-eutectic mush with a deformable and permeable mush–liquid interface. We examine the onset of convection using linear stability analysis, and the weakly nonlinear growth of liquid inclusions that signal the onset of chimneys. This analysis is compared to past analyses in which the mush–liquid interface is replaced by a rigid impermeable lid. We find qualitative agreement between the two models, but the rigid-lid approximation gives substantially different quantitative behaviour.
In linear theory, the rigid-lid approximation leads to an over-estimate of the critical Rayleigh number and wavenumber of the instability. The condition for the onset of oscillatory instability is also changed by a factor of about 5 in composition number C. In the weakly nonlinear theory, the location of the onset of liquid inclusions is near the undisturbed front for the free-boundary analysis, whereas it lies at the centre of the mushy layer when the rigid-lid approximation is used. For hexagonal patterns, the boundary between regions of parameter space in which up and down hexagons are stable, shifts as a result of coupling between the liquid and mush regions.
Angioedema of the airway: an unusual case
- A J Roper, A Farragher, J J Homer, M Helbert
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- Journal:
- The Journal of Laryngology & Otology / Volume 121 / Issue 8 / August 2007
- Published online by Cambridge University Press:
- 31 May 2007, E11
- Print publication:
- August 2007
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We report a case of angioedema caused by angiotensin-converting enzyme inhibitor and topical lignocaine spray, administered during nasendoscopy.
Angioedema induced by angiotensin-converting enzyme inhibitors is a rare but well known entity. Allergy to topical lignocaine has been acknowledged as a rare phenomenon when used for dental surgery and for skin anaesthesia, but it has not previously been reported after topical administration prior to nasendoscopy. In the reported case, our patient was unfortunate enough to be allergic to both lisinopril and lignocaine. The result was life-threatening airway obstruction, and the continued use of lignocaine spray sustained the laryngeal oedema. We advise that patients are asked about any and every allergy – specifically, any previous problems with dental procedures – before administration of local anaesthetic spray to the upper aerodigestive tract.
Buoyancy-driven crack propagation: the limit of large fracture toughness
- S. M. ROPER, J. R. LISTER
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- Journal:
- Journal of Fluid Mechanics / Volume 580 / 10 June 2007
- Published online by Cambridge University Press:
- 21 May 2007, pp. 359-380
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We study steady vertical propagation of a crack filled with buoyant viscous fluid through an elastic solid with large effective fracture toughness. For a crack fed by a constant flux Q, a non-dimensional fracture toughness K=Kc/(3μQm3/2)1/4 describes the relative magnitudes of resistance to fracture and resistance to viscous flow, where Kc is the dimensional fracture toughness, μ the fluid viscosity and m the elastic modulus. Even in the limit K ≫ 1, the rate of propagation is determined by viscous effects. In this limit the large fracture toughness requires the fluid behind the crack tip to form a large teardrop-shaped head of length O(K2/3) and width O(K4/3), which is fed by a much narrower tail. In the head, buoyancy is balanced by a hydrostatic pressure gradient with the viscous pressure gradient negligible except at the tip; in the tail, buoyancy is balanced by viscosity with elasticity also playing a role in a region within O(K2/3) of the head. A narrow matching region of length O(K−2/5) and width O(K−4/15), termed the neck, connects the head and the tail. Scalings and asymptotic solutions for the three regions are derived and compared with full numerical solutions for K ≤ 3600 by analysing the integro-differential equation that couples lubrication flow in the crack to the elastic pressure gradient. Time-dependent numerical solutions for buoyancy-driven propagation of a constant-volume crack show a quasi-steady head and neck structure with a propagation rate that decreases like t−2/3 due to the dynamics of viscous flow in the draining tail.
The UK National Action Plan on Farm Animal Genetic Resources
- G. Simm, J .A. Woolliams, G. L. H. Alderson, T. Brigstocke, M. Roper, P. Hambling
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- Journal:
- Proceedings of the British Society of Animal Science / Volume 2007 / April 2007
- Published online by Cambridge University Press:
- 23 November 2017, p. 251
- Print publication:
- April 2007
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The UK’s Farm Animal Genetic Resources (FAnGR) – its farm animal breeds, strains and varieties, and the variability within them-are of great economic, social and cultural importance. For these reasons alone it is important that we care for them, but we also have national and international obligations to do so.