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Fay CD, Corcoran B, Diamond D. Green IoT Event Detection for Carbon-Emission Monitoring in Sensor Networks. Sensors (Basel) 2023; 24:162. [PMID: 38203023 PMCID: PMC10781252 DOI: 10.3390/s24010162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 12/23/2023] [Accepted: 12/26/2023] [Indexed: 01/12/2024]
Abstract
This research addresses the intersection of low-power microcontroller technology and binary classification of events in the context of carbon-emission reduction. The study introduces an innovative approach leveraging microcontrollers for real-time event detection in a homogeneous hardware/firmware manner and faced with limited resources. This showcases their efficiency in processing sensor data and reducing power consumption without the need for extensive training sets. Two case studies focusing on landfill CO2 emissions and home energy usage demonstrate the feasibility and effectiveness of this approach. The findings highlight significant power savings achieved by minimizing data transmission during non-event periods (94.8-99.8%), in addition to presenting a sustainable alternative to traditional resource-intensive AI/ML platforms that comparatively draw and produce 20,000 times the amount of power and carbon emissions, respectively.
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Affiliation(s)
- Cormac D. Fay
- SMART Infrastructure Facility, Engineering and Information Sciences, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Brian Corcoran
- School of Mechanical and Manufacturing Engineering, Faculty of Engineering and Computing, Dublin City University, Glasnevin, D09 V209 Dublin, Ireland;
| | - Dermot Diamond
- Insight Centre for Data Analytics, Dublin City University, Glasnevin, D09 V209 Dublin, Ireland;
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Raissi G, Patel N, Casey R, Corcoran B, Sadeghi H. 152: Weekly patient-family-staff-volunteer during COVID-19. J Cyst Fibros 2021. [PMCID: PMC8518465 DOI: 10.1016/s1569-1993(21)01577-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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3
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Kowal R, Sadeghi H, Porpora K, Corcoran B. 147: Standardizing pulmonary exacerbation assessments in a multi-provider CF center. J Cyst Fibros 2021. [DOI: 10.1016/s1569-1993(21)01572-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Sewell W, Sadeghi D, Raissi G, Corcoran B, Sadeghi H. 113: Addressing food insecurity among patients with CF during the COVID-19 pandemic. J Cyst Fibros 2021. [PMCID: PMC8518442 DOI: 10.1016/s1569-1993(21)01538-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Levart D, Kalogianni E, Corcoran B, Mulholland N, Vivian G. Radiation precautions for inpatient and outpatient 177Lu-DOTATATE peptide receptor radionuclide therapy of neuroendocrine tumours. EJNMMI Phys 2019; 6:7. [PMID: 31025215 PMCID: PMC6484059 DOI: 10.1186/s40658-019-0243-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Accepted: 02/08/2019] [Indexed: 11/19/2022] Open
Abstract
Background 177Lu-DOTATATE peptide receptor radionuclide therapy is administered to patients on an inpatient and outpatient basis for the treatment of well-differentiated, metastatic neuroendocrine tumours. Following administration, these patients present an external radiation hazard due to the gamma emissions of lutetium-177. The purpose of this study was to determine precautions to be observed by 177Lu-DOTATATE patients to restrict the dose received by patients’ family members to less than 5 mSv in 5 years and members of the public to less than 1 mSv per year in line with the current UK legislation. Retrospective data from therapeutic administrations of 177Lu-DOTATATE (Mallinckrodt Pharmaceuticals) and Lutathera® (Advanced Accelerator Applications) were analysed to measure activity retention at discharge. Patient dose rate measurements were assumed to follow the same activity decay curve as that derived from a least squares fit of geometric mean counts in planar whole-body scans performed at four time points post-administration. Combining this with social contact times, the cumulative dose received through contact with the patient was estimated and an iterative process used to determine the length of contact restrictions to ensure the relevant dose constraints are not exceeded. Results On average, 36% of the administered activity was retained at the time of discharge for inpatients receiving 177Lu-DOTATATE (Mallinckrodt). Retentions of 24% and 38% were measured for Lutathera® inpatients and outpatients respectively. Inpatients should restrict day contact and sleep separately from their partner for 15 days and remain off work for 5 days post-therapy. Contact with children for whom the patient is the main carer should be restricted for 16, 13 and 9 days for children below 2, 2–5 and 5–11 years respectively. One additional day is added to outpatient restriction periods, except for children aged 2–5 years which remains 13 days. No private transport restrictions are required. Patients should limit travel by public transport to 1 h on the day of discharge. Conclusion Restrictions are necessary to limit radiation dose to members of patients’ household and the public. Proposed precautions for inpatient and outpatient 177Lu-DOTATATE therapy protocols restrict the dose received to less than the limit imposed by the UK legislation.
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Affiliation(s)
- D Levart
- Department of Nuclear Medicine, King's College Hospital NHS Foundation Trust, Denmark Hill, London, SE5 9RS, UK.
| | - E Kalogianni
- Department of Nuclear Medicine, King's College Hospital NHS Foundation Trust, Denmark Hill, London, SE5 9RS, UK
| | - B Corcoran
- Department of Nuclear Medicine, King's College Hospital NHS Foundation Trust, Denmark Hill, London, SE5 9RS, UK
| | - N Mulholland
- Department of Nuclear Medicine, King's College Hospital NHS Foundation Trust, Denmark Hill, London, SE5 9RS, UK
| | - G Vivian
- Department of Nuclear Medicine, King's College Hospital NHS Foundation Trust, Denmark Hill, London, SE5 9RS, UK
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Migone C, Barrett T, Cotter S, Clarke A, Corcoran B. The Uptake of Human Papillomavirus Vaccine In Irish Schools: The Impact Of Disadvantage. Ir Med J 2017; 110:603. [PMID: 29341515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
HPV vaccine Gardasil© is offered to girls in first year of secondary school in Ireland. We aimed to determine the association between HPV vaccine uptake among girls for academic year 2013/2014, by school and school characteristics: socioeconomic disadvantage and religious ethos. The National Schools Immunisation System (SIS) was searched to determine HPV vaccine uptake in schools for 2013/2014 (prior to recent anti-HPV vaccine publicity). The disadvantaged status and ethos of each school was added to the report. In total 577 schools were identified. Mean vaccine uptake was 83.7%. Disadvantaged schools had a lower mean uptake (%) than other schools (79.4% vs 85.0%, difference 5.58%, 95%CI 2.69-8.21) and were twice as likely to have an uptake of ?50% (OR 2.07, 95% CI 2.76 - 5.18). No difference was found between schools of different ethoses. HPV vaccine uptake is lower in disadvantaged Irish schools. Policies should be developed to ensure a more equitable uptake of HPV vaccine.
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Affiliation(s)
- C Migone
- Department of Public Health, Health Service Executive-East, Dr Steevens' Hospital, Dublin 8, Ireland
| | - T Barrett
- National Immunisation Office, Units 8-9 Manor Street Business Park, Manor Street, Dublin 7, Ireland
| | - S Cotter
- Health Protection Surveillance Centre, 25-27 Middle Gardiner Street, Dublin 1, Ireland
| | - A Clarke
- National Immunisation Office, Units 8-9 Manor Street Business Park, Manor Street, Dublin 7, Ireland
| | - B Corcoran
- National Immunisation Office, Units 8-9 Manor Street Business Park, Manor Street, Dublin 7, Ireland
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Fitzsimons D, Mullan D, Wilson J, Chew E, Conway B, Corcoran B, Gamble J, Hanna L, Mcmullan G, Mcma-Hon M, Mulholland P, Stewart C, Stockdale P. 1375: The palliative care needs of patients with heart failure from the perspective of the patient, carer and clinical team. Eur J Cardiovasc Nurs 2017. [DOI: 10.1177/14745151060050s163] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- D. Fitzsimons
- Belfast City Hospital Trust, Belfast, N Ireland BT9 7AB
- Institute of Nursing Research, University of Ulster
| | - D. Mullan
- Belfast City Hospital Trust, Belfast, N Ireland BT9 7AB
| | - J. Wilson
- Belfast City Hospital Trust, Belfast, N Ireland BT9 7AB
| | - E. Chew
- Belfast City Hospital Trust, Belfast, N Ireland BT9 7AB
| | - B. Conway
- Belfast City Hospital Trust, Belfast, N Ireland BT9 7AB
| | - B. Corcoran
- Belfast City Hospital Trust, Belfast, N Ireland BT9 7AB
| | - J. Gamble
- Belfast City Hospital Trust, Belfast, N Ireland BT9 7AB
| | - L. Hanna
- Belfast City Hospital Trust, Belfast, N Ireland BT9 7AB
| | - G. Mcmullan
- Belfast City Hospital Trust, Belfast, N Ireland BT9 7AB
| | - M. Mcma-Hon
- Belfast City Hospital Trust, Belfast, N Ireland BT9 7AB
| | - P. Mulholland
- Belfast City Hospital Trust, Belfast, N Ireland BT9 7AB
| | - C. Stewart
- Belfast City Hospital Trust, Belfast, N Ireland BT9 7AB
| | - P. Stockdale
- Belfast City Hospital Trust, Belfast, N Ireland BT9 7AB
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Lu CC, Liu MM, Culshaw G, French A, Corcoran B. Comparison of cellular changes in Cavalier King Charles spaniel and mixed breed dogs with myxomatous mitral valve disease. J Vet Cardiol 2016; 18:100-9. [PMID: 26860643 DOI: 10.1016/j.jvc.2015.12.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Revised: 12/08/2015] [Accepted: 12/18/2015] [Indexed: 11/29/2022]
Abstract
INTRODUCTION The aim of this study was to determine if there are differences in cellular changes in Cavalier King Charles spaniel (CKCS) myxomatous mitral valves compared to non-CKCS dogs. ANIMALS Cavalier King Charles spaniels (n = 6) and age-matched mixed breed (n = 6) with severe myxomatous mitral valve disease (MMVD), and normal mixed breed (n = 4) dogs. MATERIALS AND METHODS Immunohistochemistry staining and qualitative and quantitative analysis of mitral valves sections, examining for the presence of CD11c and CD45, vimentin, alpha smooth muscle actin (α-SMA) and embryonic smooth muscle myosin heavy chain (Smemb), von Willebrand factor and CD31 and Ki-67. RESULTS Vimentin positive cell numbers were increased in the MMVD dogs and distributed throughout the valve with greatest density close to the endothelium. There were no significant differences in cell marker expression for the two diseased groups, but cell numbers were significantly increased compared to controls for α-SMA (CKCS only) and Smemb (CKCS and mixed breed: p < 0.05). Alpha smooth muscle actin+ cells were primarily located at the valve edge, with Smemb+ cells similarly located, but also present throughout the valve stroma. A small number of cells close to the valve edge co-expressed α-SMA and Smemb. Endothelial von Willebrand factor expression was identified in all valves, with evidence of disrupted endothelium in the diseased, but was also found in diseased valve stroma. There was no staining for CD11c, CD45 or CD31 in any valve. Ki-67+ cells formed linear clusters at the leaflet tip and were sparsely distributed throughout both myxomatous valve groups. CONCLUSIONS The cellular changes notes with advanced stage MMVD appear similar for CKCS when compared to mixed breed dogs.
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Affiliation(s)
- C-C Lu
- Royal (Dick) School of Veterinary Studies and The Roslin Institute, The University of Edinburgh, Easterbush, Roslin, Mid-Lothian, Scotland, EH25 9RG, UK
| | - M-M Liu
- Royal (Dick) School of Veterinary Studies and The Roslin Institute, The University of Edinburgh, Easterbush, Roslin, Mid-Lothian, Scotland, EH25 9RG, UK
| | - G Culshaw
- Royal (Dick) School of Veterinary Studies and The Roslin Institute, The University of Edinburgh, Easterbush, Roslin, Mid-Lothian, Scotland, EH25 9RG, UK
| | - A French
- School of Veterinary Medicine, The University of Glasgow, Garscube Campus, Bearsden Road, Glasgow, Scotland, G61 1QH, UK
| | - B Corcoran
- Royal (Dick) School of Veterinary Studies and The Roslin Institute, The University of Edinburgh, Easterbush, Roslin, Mid-Lothian, Scotland, EH25 9RG, UK.
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Corcoran B, Linscott LL, Leach JL, Vadivelu S. Application of Normative Occipital Condyle-C1 Interval Measurements to Detect Atlanto-Occipital Injury in Children. AJNR Am J Neuroradiol 2016; 37:958-62. [PMID: 26744446 DOI: 10.3174/ajnr.a4641] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Accepted: 10/31/2015] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Prior studies have found that widening or asymmetry of the occipital condyle-C1 interval on CT is a sensitive and specific marker for atlanto-occipital dislocation. Previously reported abnormal occipital condyle-C1 interval values are not age-specific, possibly leading to false-positive findings in younger children, in whom this joint space is normally larger than that in adults. This study assesses the utility of applying age-specific normative occipital condyle-C1 interval ranges to documented cases of atlanto-occipital injury compared with previously reported abnormal cutoff values. MATERIALS AND METHODS Retrospective review of CT and MR imaging of 14 subjects with atlanto-occipital injury was performed, and occipital condyle-C1 interval measurements were made for each subject. Sensitivities and specificities of proposed occipital condyle-C1 interval cutoffs of 2 and 3 SDs above the mean and previously published occipital condyle-C1 interval cutoffs for atlanto-occipital injury were then calculated on the basis of occipital condyle-C1 interval measurements for each subject. RESULTS An occipital condyle-C1 interval 2 SDs above the age-specific mean has a sensitivity of 50% and specificity of 89%-100%, depending on the age group. An occipital condyle-C1 interval 3 SDs above the age-specific mean has a sensitivity of 50% and a specificity of 95%-100%. A 4.0-mm occipital condyle-C1 interval has a sensitivity of 36% and a specificity of 100% in all age groups. A 2.5-mm occipital condyle-C1 interval has a sensitivity of 93% and a specificity of 18%-100%. CONCLUSIONS Occipital condyle-C1 interval widening cutoffs used to establish atlanto-occipital injury lack both sensitivity and specificity in children and young teenagers. MR imaging is necessary to establish a diagnosis of atlanto-occipital injury in children and young teenagers when the appropriate mechanism of injury is present.
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Affiliation(s)
- B Corcoran
- From the Departments of Radiology (B.C., L.L.L., J.L.L.)
| | - L L Linscott
- From the Departments of Radiology (B.C., L.L.L., J.L.L.)
| | - J L Leach
- From the Departments of Radiology (B.C., L.L.L., J.L.L.)
| | - S Vadivelu
- Neurosurgery (S.V.), Cincinnati Children's Hospital Medical Center, University of Cincinnati School of Medicine, Cincinnati, Ohio
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O'Connor L, Ward M, Bennett D, Mulhall R, O'Lorcain P, Cunney R, McDermott R, Neville E, Heslin J, FitzGerald R, Meyler K, Conlon M, Clarke A, Corcoran B, Fitzpatrick G, O'Connor B, Flanagan P, O'Flanagan D, Cotter S. A prolonged outbreak of invasive meningococcal disease in an extended Irish Traveller family across three Health Service Executive (HSE) areas in Ireland, 2010 to 2013. ACTA ACUST UNITED AC 2015; 20. [PMID: 26062560 DOI: 10.2807/1560-7917.es2015.20.21.21139] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Between March 2010 and November 2013 eight laboratory-confirmed cases of serogroup B, invasive meningococcal disease (IMD) were identified in an extended Irish Traveller family across three Health Service Executive (HSE) areas of Ireland. Cases were aged between 5 and 46 months, and were either a cousin or sibling of another case. All eight cases survived. Chemoprophylaxis was given to relevant nuclear family members and close contacts on each occasion, but failed to prevent further cases. Neisseria meningitidis isolates from six cases were highly related, belonging to the ST-41/44 clonal complex, and shared the porA designation 7–2,4. In November 2013, the outbreak control team recommended that directly observed ciprofloxacin chemoprophylaxis be administered simultaneously to the extended family, and that the four component meningococcal B (4CMenB) vaccine be administered to family members aged 2 months to 23 years inclusive and relevant close contacts of the eighth case. Subsequently these recommendations were implemented at three regional clinics. Additionally pharyngeal swabs (n=112) were collected to assess carriage rates of N. meningitidis in this extended family. Pharyngeal carriage of N. meningitidis was detected in 15 (13%) family members. From the epidemiological investigation and carriage study overcrowding was the most likely risk factor identified in this outbreak. To date, the combination of directly observed ciprofloxacin chemoprophylaxis and use of 4CMenB vaccine have controlled the outbreak with no further cases diagnosed.
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Affiliation(s)
- L O'Connor
- Department of Public Health, HSE East, Dr Steevens Hospital, Dublin, Ireland
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11
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Summers KM, Ogden R, Clements DN, French AT, Gow AG, Powell R, Corcoran B, Mellanby RJ, Schoeman JP. Limited genetic divergence between dog breeds from geographically isolated countries. Vet Rec 2014; 175:562. [PMID: 25331973 PMCID: PMC4283627 DOI: 10.1136/vr.102739] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- K M Summers
- The Roslin Institute and The Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian EH25 9RG, UK
| | - R Ogden
- WildGenes Laboratory, Royal Zoological Society of Scotland, Edinburgh EH12 6TS, UK
| | - D N Clements
- The Roslin Institute and The Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian EH25 9RG, UK
| | - A T French
- Small Animal Hospital, University of Glasgow, Bearsden Road, Glasgow G61 1QH, UK
| | - A G Gow
- The Roslin Institute and The Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian EH25 9RG, UK
| | - R Powell
- Powell Torrance Diagnostic Services, Manor Farm Business Park, Higham Gobion, Hertfordshire SG5 3HR, UK
| | - B Corcoran
- The Roslin Institute and The Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian EH25 9RG, UK
| | - R J Mellanby
- The Roslin Institute and The Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian EH25 9RG, UK
| | - J P Schoeman
- Department of Companion Animal Clinical Studies, Faculty of Veterinary Science, University of Pretoria, Onderstepoort 0110, Republic of South Africa
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O'Lorcain P, Cotter S, O'Flanaqan D, Corcoran B, O'Meara M. Author response. Ir Med J 2014; 107:301. [PMID: 25417399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
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Corcoran B, Malik R, Olsson SLI, Lundström C, Karlsson M, Andrekson PA. Noise beating in hybrid phase-sensitive amplifier systems. Opt Express 2014; 22:5762-5771. [PMID: 24663914 DOI: 10.1364/oe.22.005762] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We investigate the effect of noise loading in a hybrid phase-sensitive amplifier system, analyzing the effect of noise beating between the signal and idler waves coupled in a parametric amplifier. Through analyzing input and output optical signal to noise ratios, we find that system performance of a phase-sensitive amplifier is 3 to 6 dB improved over a phase-insensitive amplifier, depending on the ratio of loaded noise power to that of vacuum fluctuations.
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O'Lorcain P, Cotter S, Hickey L, O'Flanagan D, Corcoran B, O'Meara M. Seasonal influenza vaccine uptake in HSE-funded hospitals and nursing homes during the 2011/2012 influenza season. Ir Med J 2014; 107:74-77. [PMID: 24757889] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Annual seasonal influenza vaccine is recommended for all health care workers (HCWs) in Ireland. For the 2011/2012 influenza season, information was collected on influenza vaccination uptake among HCWs employed in Health Service Executive (HSE)-funded hospitals (primarily acute) and of nursing homes (NHs) and also among NH long-term and short-term respite care residents. Forty-five hospitals (80%) and 120 NHs (75%) provided uptake data. Nationally, influenza vaccine uptake among hospital employed HCWs was estimated to be 18% and 14% among HCWs in NHs; in NHs vaccine uptake among long-term care residents was estimated to 88%. These findings highlight the continued low uptake among HCWs of all categories and demonstrate the need for sustained measures to improve uptake rates.
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Czugala M, Fay C, O'Connor NE, Corcoran B, Benito-Lopez F, Diamond D. Portable integrated microfluidic analytical platform for the monitoring and detection of nitrite. Talanta 2013; 116:997-1004. [DOI: 10.1016/j.talanta.2013.07.058] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Revised: 07/15/2013] [Accepted: 07/24/2013] [Indexed: 11/27/2022]
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16
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Florea L, Fay C, Lahiff E, Phelan T, O'Connor NE, Corcoran B, Diamond D, Benito-Lopez F. Dynamic pH mapping in microfluidic devices by integrating adaptive coatings based on polyaniline with colorimetric imaging techniques. Lab Chip 2013; 13:1079-1085. [PMID: 23358572 DOI: 10.1039/c2lc41065f] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
In this paper we present a microfluidic device that has integrated pH optical sensing capabilities based on polyaniline. The optical properties of polyaniline coatings change in response to the pH of the solution that is flushed inside the microchannel offering the possibility of monitoring pH in continuous flow over a wide pH range throughout the entire channel length. This work also features an innovative detection system for spatial localisation of chemical pH gradients along microfluidic channels through the use of a low cost optical device. Specifically, the use of a microfluidic channel coated with polyaniline is shown to respond colorimetrically to pH and that effect is detected by the detection system, even when pH gradients are induced within the channel. This study explores the capability of detecting this gradient by means of imaging techniques and the mapping of the camera's response to its corresponding pH after a successful calibration process. The provision of an inherently responsive channel means that changes in the pH of a sample moving through the system can be detected dynamically using digital imaging along the entire channel length in real time, without the need to add reagents to the sample. This approach is generic and can be applied to other chemically responsive coatings immobilised on microchannels.
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Affiliation(s)
- Larisa Florea
- CLARITY: Centre for Sensor Web Technologies, National Centre for Sensor Research, Dublin City University, Dublin, Ireland
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17
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Husko C, Vo TD, Corcoran B, Li J, Krauss TF, Eggleton BJ. Ultracompact all-optical XOR logic gate in a slow-light silicon photonic crystal waveguide. Opt Express 2011; 19:20681-20690. [PMID: 21997079 DOI: 10.1364/oe.19.020681] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We demonstrate an ultracompact, chip-based, all-optical exclusive-OR (XOR) logic gate via slow-light enhanced four-wave mixing (FWM) in a silicon photonic crystal waveguide (PhCWG). We achieve error-free operation (<10⁻⁹) for 40 Gbit/s differential phase-shift keying (DPSK) signals with a 2.8 dB power penalty. Slowing the light to vg = c/32 enables a FWM conversion efficiency, η, of -30 dB for a 396 μm device. The nonlinear FWM process is enhanced by 20 dB compared to a relatively fast mode of vg = c/5. The XOR operation requires ≈ 41 mW, corresponding to a switching energy of 1 pJ/bit. We compare the slow-light PhCWG device performance with experimentally demonstrated XOR DPSK logic gates in other platforms and discuss scaling the device operation to higher bit-rates. The ultracompact structure suggests the potential for device integration.
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Affiliation(s)
- C Husko
- Centre for Ultrahigh-bandwidth Devices for Optical Systems (CUDOS), Institute of Photonics and Optical Science (IPOS), School of Physics, University of Sydney, NSW 2006, Australia.
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Fay C, Doherty AR, Beirne S, Collins F, Foley C, Healy J, Kiernan BM, Lee H, Maher D, Orpen D, Phelan T, Qiu Z, Zhang K, Gurrin C, Corcoran B, O’Connor NE, Smeaton AF, Diamond D. Remote real-time monitoring of subsurface landfill gas migration. Sensors (Basel) 2011; 11:6603-28. [PMID: 22163975 PMCID: PMC3231696 DOI: 10.3390/s110706603] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/16/2011] [Revised: 06/15/2011] [Accepted: 06/16/2011] [Indexed: 12/04/2022]
Abstract
The cost of monitoring greenhouse gas emissions from landfill sites is of major concern for regulatory authorities. The current monitoring procedure is recognised as labour intensive, requiring agency inspectors to physically travel to perimeter borehole wells in rough terrain and manually measure gas concentration levels with expensive hand-held instrumentation. In this article we present a cost-effective and efficient system for remotely monitoring landfill subsurface migration of methane and carbon dioxide concentration levels. Based purely on an autonomous sensing architecture, the proposed sensing platform was capable of performing complex analytical measurements in situ and successfully communicating the data remotely to a cloud database. A web tool was developed to present the sensed data to relevant stakeholders. We report our experiences in deploying such an approach in the field over a period of approximately 16 months.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Alan F. Smeaton
- Author to whom correspondence should be addressed; E-Mails: (A.F.S.); (D.D.)
| | - Dermot Diamond
- Author to whom correspondence should be addressed; E-Mails: (A.F.S.); (D.D.)
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Monat C, Ebnali-Heidari M, Grillet C, Corcoran B, Eggleton BJ, White TP, O'Faolain L, Li J, Krauss TF. Four-wave mixing in slow light engineered silicon photonic crystal waveguides. Opt Express 2010; 18:22915-22927. [PMID: 21164630 DOI: 10.1364/oe.18.022915] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We experimentally investigate four-wave mixing (FWM) in short (80 μm) dispersion-engineered slow light silicon photonic crystal waveguides. The pump, probe and idler signals all lie in a 14 nm wide low dispersion region with a near-constant group velocity of c/30. We measure an instantaneous conversion efficiency of up to -9dB between the idler and the continuous-wave probe, with 1W peak pump power and 6 nm pump-probe detuning. This conversion efficiency is found to be considerably higher (>10 × ) than that of a Si nanowire with a group velocity ten times larger. In addition, we estimate the FWM bandwidth to be at least that of the flat band slow light window. These results, supported by numerical simulations, emphasize the importance of engineering the dispersion of PhC waveguides to exploit the slow light enhancement of FWM efficiency, even for short device lengths.
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Affiliation(s)
- C Monat
- Centre for Ultrahigh-bandwidth Devices for Optical Systems, Institute for Photonics and Optical Sciences, School of Physics, University of Sydney, NSW 2006, Australia.
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20
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Corcoran B, Monat C, Pelusi M, Grillet C, White TP, O'Faolain L, Krauss TF, Eggleton BJ, Moss DJ. Optical signal processing on a silicon chip at 640Gb/s using slow-light. Opt Express 2010; 18:7770-7781. [PMID: 20588618 DOI: 10.1364/oe.18.007770] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
We demonstrate optical performance monitoring of in-band optical signal to noise ratio (OSNR) and residual dispersion, at bit rates of 40Gb/s, 160Gb/s and 640Gb/s, using slow-light enhanced optical third harmonic generation (THG) in a compact (80microm) dispersion engineered 2D silicon photonic crystal waveguide. We show that there is no intrinsic degradation in the enhancement of the signal processing at 640Gb/s relative to that at 40Gb/s, and that this device should operate well above 1Tb/s. This work represents a record 16-fold increase in processing speed for a silicon device, and opens the door for slow light to play a key role in ultra-high bandwidth telecommunications systems.
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Affiliation(s)
- B Corcoran
- Institute for Photonics and Optical Sciences (IPOS), Centre for Ultra-high Bandwidth Devices for Optical Systems (CUDOS), School of Physics, University of Sydney, New South Wales 2006 Australia
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21
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Slater C, Cleary J, Lau KT, Snakenborg D, Corcoran B, Kutter JP, Diamond D. Validation of a fully autonomous phosphate analyser based on a microfluidic lab-on-a-chip. Water Sci Technol 2010; 61:1811-1818. [PMID: 20371940 DOI: 10.2166/wst.2010.069] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
This work describes the design of a phosphate analyser that utilises a microfluidic lab-on-a-chip. The analyser contains all the required chemical storage, pumping and electronic components to carry out a complete phosphate assay. The system is self-calibrating and self-cleaning, thus capable of long-term operation. This was proven by a bench top calibration of the analyser using standard solutions and also by comparing the analyser's performance to a commercially available phosphate monitor installed at a waste water treatment plant. The output of the microfluidic lab-on-a-chip analyser was shown to have sensitivity and linear range equivalent to the commercially available monitor and also the ability to operate over an extended period of time.
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Affiliation(s)
- C Slater
- CLARITY: Centre for Sensor Web Technologies, Dublin City University, Dublin, Ireland.
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22
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Ananta E, Birkeland SE, Corcoran B, Fitzgerald G, Hinz S, Klijn A, Mättö J, Mercernier A, Nilsson U, Nyman M, O'Sullivan E, Parche S, Rautonen N, Ross R, Saarela M, Stanton C, Stahl U, Suomalainen T, Vincken JP, Virkajärvi I, Voragen F, Wesenfeld J, Wouters R, Knorr D. Processing effects on the nutritional advancement of probiotics and prebiotics. Microbial Ecology in Health and Disease 2009. [DOI: 10.1080/08910600410032277] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- E. Ananta
- From the Berlin University of Technology (TUBER LMT), Department of Food Biotechnology and Food Process Engineering, Koenigin-Luise-Str. 22, 14195, Berlin, Germany
| | - S.-E. Birkeland
- TINE Norway, TINE Research and development, PO Box 7, Kalbakken, NO-0902, Oslo, Norway
| | - B. Corcoran
- Teagasc Dairy Products Research Centre (Teagasc), Moorepark, Fermoy, Co. Cork, Ireland
| | - G. Fitzgerald
- University College Cork (UCC), National Food Biotechnology Centre, University College, Western Road, Cork, Ireland
| | - S. Hinz
- Wageningen University (WAU), Department of Agrotechnology and Food Sciences, Laboratory of Food Chemistry and Laboratory of Food Microbiology, Bomenweg 2, 6703 HD, Wageningen, The Netherlands
| | - A. Klijn
- Nestle Research Center (NRC), Vers-chez-les-Blanc 1000 Lausanne 26, Switzerland
| | - J. Mättö
- VTT Biotechnology (VTT), PO Box 1500, 02044 VTT, Finland
| | - A. Mercernier
- Nestle Research Center (NRC), Vers-chez-les-Blanc 1000 Lausanne 26, Switzerland
| | - U. Nilsson
- Lund University (ULund), Department of Applied Nutrition and Food Chemistry, Center for Chemistry and Chemical Engineering, Lund University, PO Box 124, 221 00, Lund, Sweden
| | - M. Nyman
- Lund University (ULund), Department of Applied Nutrition and Food Chemistry, Center for Chemistry and Chemical Engineering, Lund University, PO Box 124, 221 00, Lund, Sweden
| | - E. O'Sullivan
- University College Cork (UCC), National Food Biotechnology Centre, University College, Western Road, Cork, Ireland
| | - S. Parche
- Nestle Research Center (NRC), Vers-chez-les-Blanc 1000 Lausanne 26, Switzerland
| | - N. Rautonen
- Danisco Cultor Innovation Kantvik (Danisco), Cultor Technology Center, 02460, Kantvik, Finland
| | - R.P. Ross
- Teagasc Dairy Products Research Centre (Teagasc), Moorepark, Fermoy, Co. Cork, Ireland
- Alimentary Pharmabiotic Centre, Cork, Ireland
| | - M. Saarela
- VTT Biotechnology (VTT), PO Box 1500, 02044 VTT, Finland
| | - C. Stanton
- Teagasc Dairy Products Research Centre (Teagasc), Moorepark, Fermoy, Co. Cork, Ireland
- Alimentary Pharmabiotic Centre, Cork, Ireland
| | - U. Stahl
- Berlin University of Technology (TUBER BT), Department of Microbiology and Genetics, Gustav-Meyer-Allee 25, 13355, Berlin, Germany
| | - T. Suomalainen
- Valio Ltd (Valio), Research and Development Centre, PO Box 30, 00039, VALIO, Finland
| | - J.-P. Vincken
- Wageningen University (WAU), Department of Agrotechnology and Food Sciences, Laboratory of Food Chemistry and Laboratory of Food Microbiology, Bomenweg 2, 6703 HD, Wageningen, The Netherlands
| | - I. Virkajärvi
- VTT Biotechnology (VTT), PO Box 1500, 02044 VTT, Finland
| | - F. Voragen
- Wageningen University (WAU), Department of Agrotechnology and Food Sciences, Laboratory of Food Chemistry and Laboratory of Food Microbiology, Bomenweg 2, 6703 HD, Wageningen, The Netherlands
| | - J. Wesenfeld
- Berlin University of Technology (TUBER BT), Department of Microbiology and Genetics, Gustav-Meyer-Allee 25, 13355, Berlin, Germany
| | - R. Wouters
- Tiense Suikerraffinaderij nv (ORAFTI), Aandorenstraat 1, 3300, Tienen, Belgium
| | - D. Knorr
- From the Berlin University of Technology (TUBER LMT), Department of Food Biotechnology and Food Process Engineering, Koenigin-Luise-Str. 22, 14195, Berlin, Germany
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23
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Meara MO, Morrissey Y, Corcoran B. Customer satisfaction survey with the National Vaccine Cold Chain Delivery Service. Ir Med J 2009; 102:155. [PMID: 19623813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
In 2008 the Health Service Executive (HSE) carried out a survey to assess general practitioners (GPs) satisfaction with the National Vaccine Cold Chain Service. This survey found high levels of satisfaction (> 90%) with the service. Over half of those surveyed had used the vaccine returns service with the majority (89.2%) finding it good or very good.
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Affiliation(s)
- M O Meara
- National Immunisation Office, 8-9 Manor St Business Park, Manor St, Dublin.
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Abstract
A 10-year-old male cairn terrier cross was presented with a history of myxomatous mitral valve disease diagnosed six months previously and with a four-week history of intermittent collapse. On 24 hour electrocardiograph (Holter) analysis, periods of no discernable electrical cardiac activity, which coincided with three collapsing episodes, were identified. Unfortunately, on re-presentation for removal of the Holter monitor, the dog collapsed and died. A post-mortem examination was conducted, and histology of the right and left atrium showed evidence of myocarditis. This is the first reported case, to our knowledge, of collapse because of electrical asystole in a dog with atrial myocarditis.
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Affiliation(s)
- R Woolley
- Department of Veterinary Clinical Studies, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Hospital for Small Animals, Easter Bush, Roslin, Midlothian EH25 9RG, UK
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Fitzsimons D, Mullan D, Wilson JS, Conway B, Corcoran B, Dempster M, Gamble J, Stewart C, Rafferty S, McMahon M, MacMahon J, Mulholland P, Stockdale P, Chew E, Hanna L, Brown J, Ferguson G, Fogarty D. The challenge of patients' unmet palliative care needs in the final stages of chronic illness. Palliat Med 2007; 21:313-22. [PMID: 17656408 DOI: 10.1177/0269216307077711] [Citation(s) in RCA: 182] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND There is consensus in the literature that the end of life care for patients with chronic illness is suboptimal, but research on the specific needs of this population is limited. AIM This study aimed to use a mixed methodology and case study approach to explore the palliative care needs of patients with a non-cancer diagnosis from the perspectives of the patient, their significant other and the clinical team responsible for their care. Patients (n = 18) had a diagnosis of either end-stage heart failure, renal failure or respiratory disease. METHODS The Short Form 36 and Hospital and Anxiety and Depression Questionnaire were completed by all patients. Unstructured interviews were (n = 35) were conducted separately with each patient and then their significant other. These were followed by a focus group discussion (n = 18) with the multiprofessional clinical team. Quantitative data were analysed using simple descriptive statistics and simple descriptive statistics. All qualitative data were taped, transcribed and analysed using Colaizzi's approach to qualitative analysis. FINDINGS Deteriorating health status was the central theme derived from this analysis. It led to decreased independence, social isolation and family burden. These problems were mitigated by the limited resources at the individual's disposal and the availability of support from hospital and community services. Generally resources and support were perceived as lacking. All participants in this study expressed concerns regarding the patients' future and some patients described feelings of depression or acceptance of the inevitability of imminent death. CONCLUSION Patients dying from chronic illness in this study had many concerns and unmet clinical needs. Care teams were frustrated by the lack of resources available to them and admitted they were ill-equipped to provide for the individual's holistic needs. Some clinicians described difficulty in talking openly with the patient and family regarding the palliative nature of their treatment. An earlier and more effective implementation of the palliative care approach is necessary if the needs of patients in the final stages of chronic illness are to be adequately addressed.
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Affiliation(s)
- D Fitzsimons
- Nursing Research and Development, Belfast City Hospital, Belfast, Northern Ireland.
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26
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Ananta E, Birkeland SE, Corcoran B, Fitzgerald G, Hinz S, Klijn A, Mättö J, Mercernier A, Nilsson U, Nyman M, O`Sullivan E, Parche S, Rautonen N, Ross R, Saarela M, Stanton C, Stahl U, Suomalainen T, Vincken JP, Virkajärvi I, Voragen F, Wesenfeld J, Wouters R, Knorr D. Processing Effects on the Nutritional Advancement of Probiotics and Prebiotics. Microbial Ecology in Health & Disease 2004. [DOI: 10.3402/mehd.v16i2-3.7933] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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27
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Höglund K, French A, Dukes-McEwan J, Häggström J, Smith P, Corcoran B, Kvart C. Low intensity heart murmurs in boxer dogs: inter-observer variation and effects of stress testing. J Small Anim Pract 2004; 45:178-85. [PMID: 15116885 DOI: 10.1111/j.1748-5827.2004.tb00221.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Inter-observer variation in the detection and grading of low intensity heart murmurs in boxer dogs was investigated. Six veterinarians with different levels of experience examined 27 boxers by cardiac auscultation. The dogs were auscultated before and after exercise, and the results were compared with phonocardiographic and echocardiographic examinations performed at rest and during two different stress tests. A subvalvular aortic ridge was identified in six dogs on two-dimensional echocardiography. Using dogs with low intensity murmurs or dogs free of heart murmurs, inter-observer agreement was positively correlated to the level of experience at rest (weighted kappa [kappa] 0.14 to 0.75), while the agreement was poor after exercise (weighted kappa 0.01 to 0.36). The presence of a subvalvular aortic ridge was associated with higher aortic flow velocities (P<0.002) and higher auscultatory murmur grading (P<0.001). There was an increase in murmur duration during one kind of stress test (P<0.001) and in aortic flow velocity during the other (P=0.001).
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Affiliation(s)
- K Höglund
- Department of Anatomy and Physiology, Faculty of Veterinary Medicine, Swedish University of Agricultural Sciences, PO Box 7045, 750 07 Uppsala, Sweden
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28
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Abstract
Thirty-five boxers that had been referred to the Royal (Dick) School of Veterinary Studies between 1989 and 1994 with left heart base murmurs and aortic velocities greater than 1.5 m/second on Doppler echocardiography were recalled for clinical examination and Doppler echocardiography between 1995 and 1996. Five dogs (14 per cent) showed an increase in murmur grade on repeat visit. Six dogs (17 per cent) showed an increase in aortic velocity of greater than 20 per cent. Eight dogs (23 per cent) had developed aortic valvular or subvalvular two-dimensional echocardiographic changes that had not been present at the initial visit. Seven dogs (20 per cent) had developed aortic regurgitation, and three dogs (8 per cent) mitral regurgitation.
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Affiliation(s)
- A French
- Department of Veterinary Clinical Studies, Royal School of Veterinary Studies, Hospital for Small Animals, University of Edinburgh, Easter Bush Veterinary Center, Roslin, Midlothian
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29
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Rhind SM, Scudamore CL, Clutton RE, McDiarmid AM, Penny CD, Penny LA, Anderson A, Burnie AG, Camburn MA, Corcoran B, Dukes McEwan J, French A, Griffon D, Hill PB, Kirby BM, Meredith AL, Redrobe SP, Simpson JW, Thoday KL. Staffing at veterinary schools. Vet Rec 1998; 142:406. [PMID: 9586136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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30
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Corcoran B. Canine parvovirus vaccination. Vet Rec 1984; 114:228. [PMID: 6328735 DOI: 10.1136/vr.114.9.228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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31
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Corcoran B, Arthurs Y, Fielding JF. 'Pleuritic' chest pain due to post traumatic intrathoracic infarction of the stomach. Ir J Med Sci 1981; 150:82-3. [PMID: 7228603 DOI: 10.1007/bf02938205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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33
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Aswanikumar S, Corcoran B, Schiffmann E, Day AR, Freer RJ, Showell HJ, Becker EL. Demonstration of a receptor on rabbit neutrophils for chemotactic peptides. Biochem Biophys Res Commun 1977; 74:810-7. [PMID: 836328 DOI: 10.1016/0006-291x(77)90375-8] [Citation(s) in RCA: 259] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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34
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Showell HJ, Freer RJ, Zigmond SH, Schiffmann E, Aswanikumar S, Corcoran B, Becker EL. The structure-activity relations of synthetic peptides as chemotactic factors and inducers of lysosomal secretion for neutrophils. J Exp Med 1976; 143:1154-69. [PMID: 1262785 PMCID: PMC2190180 DOI: 10.1084/jem.143.5.1154] [Citation(s) in RCA: 567] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
24 di-, tri-, and tetrapeptides have been synthesized as a start of a systematic study of the structural requirements for chemotactic activity and lysosomal enzyme-releasing ability in rabbit neutrophils. All but two of them are N-formyl methionyl peptides. Using the method of Zigmond and Hirsch (10), two representative peptides, F-Met-Leu-Phe and F-Met-Met-Met, were shown to stimulate directed, as well as, random locomotion; thus, they were truly chemotactic. The various peptides showed a wide spread in activity. F-Met-Leu-Phe, the most active peptide studied, had an ED50 for induced migration of 7 X 10(-11) M and for lysozyme and beta-glucuronidase release of 2.4 X 10(-10) M and 2.6 X 10(-10) M, respectively; the least active, Met-Leu-Glu was 26 million times less active in these respects. The relation of activity to structure is exceedingly specific, very small changes in structure making large changes in activity. Moreover, this specificity exhibits a definite regularity and pattern; the activity of a given peptide depends not only on its constituent amino acids but on the position of the amino acid in the peptide chain. Most striking in this last regards is the high activity conferred by phenylalanine when it is in the carboxyl terminal position of a tripeptide, whereas, as the second amino acid from the NH2 terminal end whether in a tripeptide or a dipeptide, it contributes no more to the activity than other amino acids with hydrophobic side chains such as leucine or methionine. The high activity and the specificity and nature of the structural requirements strongly suggest that the primary interaction of peptide and neutrophil leading to either chemotaxis or lysosomal enzyme release is a binding of the peptide with a stereospecific receptor on the neutrophil surface. Whether all chemotactic factors act through the same receptor is not known. An essentially exact correlation exists between the concentrations of the various synthetic peptides required to induce migration and their ability to induce release of lysozyme or beta-glucuronidase. This implies that these two neutrophil functions are triggered by teh same primary interaction; possibly, the binding of the peptides to the same putative receptor. A higher concentration of a given peptide is required to stimulate lysosomal enzyme release than a corresponding migratory response. A slightly but significantly higher concentration of peptide is required to induce beta-glucuronidase secretion than lysozyme release.
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