oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2020 ( 4 )

2019 ( 403 )

2018 ( 522 )

2017 ( 540 )

Custom range...

Search Results: 1 - 10 of 327126 matches for " Cameron S Palmer "
All listed articles are free for downloading (OA Articles)
Page 1 /327126
Display every page Item
Assessment of the effects and limitations of the 1998 to 2008 Abbreviated Injury Scale map using a large population-based dataset
Cameron S Palmer, Melanie Franklyn
Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine , 2011, DOI: 10.1186/1757-7241-19-1
Abstract: The entire AIS98-coded injury dataset of a large population based trauma registry was retrieved and mapped to AIS08 using the currently available AIS98-AIS08 dictionary map. The percentage of codes which had increased or decreased in severity, or could not be mapped, was examined in conjunction with the effect of these changes to the calculated ISS. The potential for free text information accompanying AIS coding to improve the quality of AIS mapping was explored.A total of 128280 AIS98-coded injuries were evaluated in 32134 patients, 15471 patients of whom were classified as major trauma. Although only 4.5% of dictionary codes decreased in severity from AIS98 to AIS08, this represented almost 13% of injuries in the registry. In 4.9% of patients, no injuries could be mapped. ISS was potentially unreliable in one-third of patients, as they had at least one AIS98 code which could not be mapped. Using AIS08, the number of patients classified as major trauma decreased by between 17.3% and 30.3%. Evaluation of free text descriptions for some injuries demonstrated the potential to improve mapping between AIS versions.Converting AIS98-coded data to AIS08 results in a significant decrease in the number of patients classified as major trauma. Many AIS98 codes are missing from the existing AIS map, and across a trauma population the AIS08 dataset estimates which it produces are of insufficient quality to be used in practice. However, it may be possible to improve AIS98 to AIS08 mapping to the point where it is useful to established registries.Accurately determining the burden of significant injury within a given population is an essential role of a trauma system. Trauma data can be used for a range of applications including monitoring changes in injury epidemiology, trauma management and outcome over time, appropriate direction of funding, and population or outcome comparisons between institutions or regions. In order to monitor trauma systems most effectively, trauma registri
Differences and discrepancies between 2005 and 2008 Abbreviated Injury Scale versions - time to standardise
Kjetil G Ringdal, Morten Hestnes, Cameron S Palmer
Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine , 2012, DOI: 10.1186/1757-7241-20-11
Abstract: In order for trauma registry data to be comparable across institutions and trauma systems, the injury classification systems which underpin them must be comparable and consistent. In most trauma registries, injuries are classified using the Abbreviated Injury Scale (AIS) [1,2]. AIS-derived scores such as the Injury Severity Score (ISS) [3] and New Injury Severity Score [4] are used to quantify the severity of (and compare) multiply injured patients; to select patients for inclusion in registries; and as part of the definitions used to describe major trauma. Consequently, consistency of the AIS codesets used is pivotal to the purpose and validity of trauma registries.The Association for the Advancement of Automotive Medicine (AAAM) has updated and maintained the AIS since the early 1970s. Since its initial publication, the AIS codeset has expanded and evolved over several editions. The current version of the AIS (AIS08) [2] is a 2008 update of the greatly expanded 2005 edition (AIS05) [1]. The changes implemented between AIS05 and AIS08 are known to be comparatively minor [5,6]. However, the effect of these changes on actual datasets has not been assessed.Between the 2005 and 2008 AIS releases, the AAAM released an unknown number of periodic updates. These contained individual AIS dictionary pages on which one or more AIS codes had been updated, with the intent that they could replace earlier versions of the pages in users' AIS05 dictionaries. However, it was not always clear which codes were updated on each page, despite this being crucial for users of electronic versions of the AIS. Also, if users purchased AIS dictionaries during this gradual update process or did not update their dictionaries over time, it is possible that not all AIS05 or AIS08 dictionaries in use contain the same codesets or coding instructions.Consequently, we aimed to identify all of the changes made to the AIS codeset since 2005. We therefore evaluated all of the codeset updates (additions,
Development and validation of a complementary map to enhance the existing 1998 to 2008 Abbreviated Injury Scale map
Cameron S Palmer, Melanie Franklyn, Christine Read-Allsopp, Susan McLellan, Louise E Niggemeyer
Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine , 2011, DOI: 10.1186/1757-7241-19-29
Abstract: Using a modified Delphi process, a panel of expert AIS coders established plausible AIS08 equivalents for the 153 AIS98 codes which currently have no AIS08 map. A series of major trauma patients whose injuries had been double-coded in AIS98 and AIS08 was used to assess the maps; both of the AIS datasets had already been mapped to another AIS version using the AIS dictionary maps. Following application of the completed (enhanced) map with or without free text evaluation, up to six AIS codes were available for each injury. Datasets were assessed for agreement in injury severity measures, and the relative performances of the maps in accurately describing the trauma population were evaluated.The double-coded injuries sustained by 109 patients were used to assess the maps. For data conversion from AIS98, both the enhanced map and the enhanced map with free text description resulted in higher levels of accuracy and agreement with directly coded AIS08 data than the currently available dictionary map. Paired comparisons demonstrated significant differences between direct coding and the dictionary maps, but not with either of the enhanced maps.The newly-developed AIS98 to AIS08 complementary map enabled transformation of the trauma population description given by AIS98 into an AIS08 estimate which was statistically indistinguishable from directly coded AIS08 data. It is recommended that the enhanced map should be adopted for dataset conversion, using free text descriptions if available.In many trauma systems, the Abbreviated Injury Scale (AIS) [1,2] is central to assessing the burden of injury. By assigning a discrete ordinal value to the severity of each injury sustained, the AIS permits documentation of injuries sustained by patients in a form which can readily be used to evaluate epidemiological, engineering, management and outcome aspects of trauma. Using derived scores such as the Injury Severity Score (ISS) [3] and the New Injury Severity Score (NISS) [4], comparisons
The Role of Maternal Stress in Early Pregnancy in the Aetiology of Gastroschisis: An Incident Case Control Study
Stephen R. Palmer, Annette Evans, Hannah Broughton, Simon Huddart, Mark Drayton, Judith Rankin, Elizabeth S. Draper, Alan Cameron, Shantini Paranjothy
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0080103
Abstract: Objective The incidence of gastroschisis, a congenital anomaly where the infant abdominal wall is defective and intestines protrude from the abdominal cavity, is increasing in many countries. The role of maternal stress in some adverse birth outcomes is now well established. We tested the hypothesis that major stressful life events in the first trimester are risk factors for gastroschisis, and social support protective, in a case-control study in the United Kingdom. Methods Gastroschisis cases and three controls per case (matched for maternal age) were identified at routine 18-20 week fetal anomaly ultrasound scan, in 2007-2010. Face to face questionnaire interviews were carried out during the antenatal period (median 24 weeks gestation) asking about serious stressful events and social support in the first trimester. Data were analysed using conditional logistic regression. Results Two or more stressful life events in the first trimester (adjusted OR 4.9; 95% CI 1.2-19.4), and moving address in the first trimester (aOR 4.9; 95% CI 1.7-13.9) were strongly associated with risk of gastroschisis, independent of behavioural risk factors including smoking, alcohol, and poor diet. Perceived availability of social support was not associated with reduced risk of gastroschisis (aOR 0.8; 95% CI 0.2-3.1). Conclusions Stressful maternal life events in the first trimester of pregnancy including change of address were strongly associated with a substantial increase in the risk of gastroschisis, independent of stress related high risk behaviours such as smoking, alcohol consumption and poor diet. This suggests that stress pathways are involved in the aetiology of gastroschisis.
GeneZip: A software package for storage-efficient processing of genotype data
Cameron Palmer,Itsik Pe'er
Quantitative Biology , 2013,
Abstract: Genome wide association studies directly assay 10^6 single nucleotide polymorphisms (SNPs) across a study cohort. Probabilistic estimation of additional sites by genotype imputation can increase this set of variants by 10- to 40-fold. Even with modest sample sizes (10^3-10^4), these resulting imputed datasets, containing 10^10-10^11 double-precision values, are incompatible with simultaneous lossless storage in RAM using standard methods. Existing solutions for this problem require compromises in either genotype accuracy or complexity of permissible statistical methods. Here, we present a C/C++ library that dynamically compresses probabilistic genotype data as they are loaded into memory. This method uses a customization of the DEFLATE (gzip) algorithm, and maintains constant-time access to any SNP. Average compression ratios of more than 9-fold are observed in test data.
Collecting core data in severely injured patients using a consensus trauma template: an international multicentre study
Kjetil Ringdal, Hans Lossius, J Mary Jones, Jens M Lauritsen, Timothy J Coats, Cameron S Palmer, Rolf Lefering, Stefano Di Bartolomeo, David J Dries, Kjetil S?reide, The Utstein Trauma Data Collaborators
Critical Care , 2011, DOI: 10.1186/cc10485
Abstract: Trauma centres from three different continents were invited to submit Utstein Trauma Template core data during a defined period, for up to 50 consecutive trauma patients. Directly admitted patients with a New Injury Severity Score (NISS) equal to or above 16 were included. Main outcome variables were data completeness, data differences and data collection difficulty.Centres from Europe (n = 20), North America (n = 3) and Australia (n = 1) submitted data on 965 patients, of whom 783 were included. Median age was 41 years (interquartile range (IQR) 24 to 60), and 73.1% were male. Median NISS was 27 (IQR 20 to 38), and blunt trauma predominated (91.1%). Of the 36 Utstein variables, 13 (36%) were collected by all participating centres. Eleven (46%) centres applied definitions of the survival outcome variable that were different from those of the template. Seventeen (71%) centres used the recommended version of the Abbreviated Injury Scale (AIS). Three variables (age, gender and AIS) were documented in all patients. Completeness > 80% was achieved for 28 variables, and 20 variables were > 90% complete.The Utstein Template was feasible across international trauma centres for the majority of its data variables, with the exception of certain physiological and time variables. Major differences were found in the definition of survival and in AIS coding. The current results give a clear indication of the attainability of information and may serve as a stepping-stone towards creation of a European trauma registry.Major trauma is a leading cause of death and disability around the world [1], and it accounts for approximately 10% of the world's deaths. Globally, unintentional injuries are ranked as the sixth leading cause of death and the fifth leading cause of moderate and severe disability [2]. The introduction of regionalised trauma systems has the potential to reduce preventable deaths [3], but an improved understanding of the benefits and limitations of different trauma care
The common G-866A polymorphism of the UCP2 gene and survival in diabetic patients following myocardial infarction
Barry R Palmer, Courtney L Devereaux, Sukhbir S Dhamrait, Tessa J Mocatta, Anna P Pilbrow, Chris M Frampton, Lorraine Skelton, Tim G Yandle, Christine C Winterbourn, A Mark Richards, Hugh E Montgomery, Vicky A Cameron
Cardiovascular Diabetology , 2009, DOI: 10.1186/1475-2840-8-31
Abstract: UCP2 G-866A genotypes were determined using a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) protocol. Myeloperoxidase levels were measured in plasma samples taken from 419 cohort patients 24–96 hours after admission.Genotypes were obtained for 901 patients with genotype frequencies AA 15.5%, GA 45.5%, and GG 39.0%. Genotype was not associated with survival in the overall cohort (mortality: AA 15.6%, GA 16.8%, GG 19.4%, p = 0.541). However, amongst diabetics, AA and GA genotype groups had significantly worse survival than GG diabetic patients (p < 0.05) with an attributable risk of 23.3% and 18.7% for those of AA and GA genotype respectively. Multivariate analysis using a Cox proportional hazards model confirmed that the interaction of diabetes with genotype was significantly predictive of survival (p = 0.031). In the cohort's diabetic subgroup AA/GA patients had higher myeloperoxidase levels than their GG counterparts (GA/AA, n = 51, 63.9 ± 5.23; GG, n = 34, 49.1 ± 3.72 ng/ml, p = 0.041). Further analysis showed that this phenomenon was confined to male patients (GA/AA, n = 36, 64.3 ± 6.23; GG, n = 29, 44.9 ± 3.72 ng/ml, p = 0.015).Diabetic patients in this post-myocardial infarction cohort with UCP2 -866 AA/GA genotype have poorer survival and higher myeloperoxidase levels than their GG counterparts.Uncoupling protein 2 (UCP2) is expressed ubiquitously and is believed to dissipate the proton motive force across the inner mitochondrial membrane [1,2]. While UCP1 may play a role in thermogenesis [3], UCP2 may regulate inflammation and apoptosis, and inhibition of the mitochondrial production of reactive oxygen species (ROS) [4]. These functions have important implications for brain and heart disease. experimental inhibition of UCP2 expression increases ROS formation [5,6], a risk factor for atherosclerosis [7]. UCP2 has recently been shown to mediate some of the actions of ghrelin [8], a circulating hormone elevated during fasting and
Evidence for Maternal-Fetal Genotype Incompatibility as a Risk Factor for Schizophrenia
Christina G. S. Palmer
Journal of Biomedicine and Biotechnology , 2010, DOI: 10.1155/2010/576318
Abstract: Prenatal/obstetric complications are implicated in schizophrenia susceptibility. Some complications may arise from maternal-fetal genotype incompatibility, a term used to describe maternal-fetal genotype combinations that produce an adverse prenatal environment. A review of maternal-fetal genotype incompatibility studies suggests that schizophrenia susceptibility is increased by maternal-fetal genotype combinations at the RHD and HLA-B loci. Maternal-fetal genotype combinations at these loci are hypothesized to have an effect on the maternal immune system during pregnancy which can affect fetal neurodevelopment and increase schizophrenia susceptibility. This article reviews maternal-fetal genotype incompatibility studies and schizophrenia and discusses the hypothesized biological role of these ‘‘incompatibility genes’’. It concludes that research is needed to further elucidate the role of RHD and HLA-B maternal-fetal genotype incompatibility in schizophrenia and to identify other genes that produce an adverse prenatal environment through a maternal-fetal genotype incompatibility mechanism. Efforts to develop more sophisticated study designs and data analysis techniques for modeling maternal-fetal genotype incompatibility effects are warranted.
TransCom model simulations of CH4 and related species: linking transport, surface flux and chemical loss with CH4 variability in the troposphere and lower stratosphere
P. K. Patra, S. Houweling, M. Krol, P. Bousquet, D. Belikov, D. Bergmann, H. Bian, P. Cameron-Smith, M. P. Chipperfield, K. Corbin, A. Fortems-Cheiney, A. Fraser, E. Gloor, P. Hess, A. Ito, S. R. Kawa, R. M. Law, Z. Loh, S. Maksyutov, L. Meng, P. I. Palmer, R. G. Prinn, M. Rigby, R. Saito,C. Wilson
Atmospheric Chemistry and Physics (ACP) & Discussions (ACPD) , 2011,
Abstract: A chemistry-transport model (CTM) intercomparison experiment (TransCom-CH4) has been designed to investigate the roles of surface emissions, transport and chemical loss in simulating the global methane distribution. Model simulations were conducted using twelve models and four model variants and results were archived for the period of 1990–2007. All but one model transports were driven by reanalysis products from 3 different meteorological agencies. The transport and removal of CH4 in six different emission scenarios were simulated, with net global emissions of 513 ± 9 and 514 ± 14 Tg CH4 yr 1 for the 1990s and 2000s, respectively. Additionally, sulfur hexafluoride (SF6) was simulated to check the interhemispheric transport, radon (222Rn) to check the subgrid scale transport, and methyl chloroform (CH3CCl3) to check the chemical removal by the tropospheric hydroxyl radical (OH). The results are compared to monthly or annual mean time series of CH4, SF6 and CH3CCl3 measurements from 8 selected background sites, and to satellite observations of CH4 in the upper troposphere and stratosphere. Most models adequately capture the vertical gradients in the stratosphere, the average long-term trends, seasonal cycles, interannual variations (IAVs) and interhemispheric (IH) gradients at the surface sites for SF6, CH3CCl3 and CH4. The vertical gradients of all tracers between the surface and the upper troposphere are consistent within the models, revealing vertical transport differences between models. An average IH exchange time of 1.39 ± 0.18 yr is derived from SF6 time series. Sensitivity simulations suggest that the estimated trends in exchange time, over the period of 1996–2007, are caused by a change of SF6 emissions towards the tropics. Using six sets of emission scenarios, we show that the decadal average CH4 growth rate likely reached equilibrium in the early 2000s due to the flattening of anthropogenic emission growth since the late 1990s. Up to 60% of the IAVs in the observed CH4 concentrations can be explained by accounting for the IAVs in emissions, from biomass burning and wetlands, as well as meteorology in the forward models. The modeled CH4 budget is shown to depend strongly on the troposphere-stratosphere exchange rate and thus on the model's vertical grid structure and circulation in the lower stratosphere. The 15-model median CH4 and CH3CCl3 atmospheric lifetimes are estimated to be 9.99 ± 0.08 and 4.61 ± 0.13 yr, respectively, with little IAV due to transport and temperature.
Off-line algorithm for calculation of vertical tracer transport in the troposphere due to deep convection
D. A. Belikov, S. Maksyutov, M. Krol, A. Fraser, M. Rigby, H. Bian, A. Agusti-Panareda, D. Bergmann, P. Bousquet, P. Cameron-Smith, M. P. Chipperfield, A. Fortems-Cheiney, E. Gloor, K. Haynes, P. Hess, S. Houweling, S. R. Kawa, R. M. Law, Z. Loh, L. Meng, P. I. Palmer, P. K. Patra, R. G. Prinn, R. Saito,C. Wilson
Atmospheric Chemistry and Physics (ACP) & Discussions (ACPD) , 2013,
Abstract: A modified cumulus convection parametrisation scheme is presented. This scheme computes the mass of air transported upward in a cumulus cell using conservation of moisture and a detailed distribution of convective precipitation provided by a reanalysis dataset. The representation of vertical transport within the scheme includes entrainment and detrainment processes in convective updrafts and downdrafts. Output from the proposed parametrisation scheme is employed in the National Institute for Environmental Studies (NIES) global chemical transport model driven by JRA-25/JCDAS reanalysis. The simulated convective precipitation rate and mass fluxes are compared with observations and reanalysis data. A simulation of the short-lived tracer 222Rn is used to further evaluate the performance of the cumulus convection scheme. Simulated distributions of 222Rn are evaluated against observations at the surface and in the free troposphere, and compared with output from models that participated in the TransCom-CH4 Transport Model Intercomparison. From this comparison, we demonstrate that the proposed convective scheme in general is consistent with observed and modeled results.
Page 1 /327126
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.