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Nomura H, Hanker L, Fabbro M, Rau J, Kim Y, Arija JA, Friedlander M, Ferrandina G, Vuylsteke P, Colombo N, Malander S, Monk B, Petru E, Calvert P, Herzog T, Barrett C, Jobanputra M, Wang Q, Elser G, Du Bois A. Pazopanib Versus Placebo in Women Without Progression After First-Line Chemotherapy for Advanced Epithelial Ovarian, Fallopian Tube, or Primary Peritoneal Cancer (Aeoc): Second Interim Overall Survival Analysis from the Ago-Ovar16 Trial. Ann Oncol 2014. [DOI: 10.1093/annonc/mdu338.6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Barrett C, van Uum S, Lenders JW. Risks of catecholaminergic crisis following steroid administration in patients with an adrenal mass: a literature review. Exp Clin Endocrinol Diabetes 2014. [DOI: 10.1055/s-0034-1372147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Catenacci VA, Barrett C, Odgen L, Browning R, Schaefer CA, Hill J, Wyatt H. Changes in physical activity and sedentary behavior in a randomized trial of an internet-based versus workbook-based family intervention study. J Phys Act Health 2014; 11:348-58. [PMID: 23364318 PMCID: PMC4570826 DOI: 10.1123/jpah.2012-0043] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
BACKGROUND The America on the Move (AOM) Family Intervention Program has been shown to prevent excess weight gain in overweight children. Providing intervention materials via the internet would have the potential to reach more families but may increase sedentary behavior. The purpose was to evaluate whether delivering the AOM Family Intervention via the internet versus printed workbook would have a similar impact on sedentary behaviors in children. METHODS 131 children (age 8-12) were randomized to receive the AOM Family Intervention via the internet or workbook for 12 weeks. Changes in objectively measured sedentary time and moderate-to vigorous physical activity (MVPA) as well as self-reported screen time were compared between groups. RESULTS There were no significant differences between groups in screen time, sedentary time, or MVPA at the end of the 12 week intervention. Families receiving the intervention via the internet were more likely to remain in the study (98% vs. 82%, P = .016). CONCLUSIONS Using the internet to deliver the lifestyle intervention did not increase sedentary behavior in children. Attrition rates were lower when the program was delivered by internet versus via printed materials. These results provide support for using the internet to deliver healthy lifestyle programs for children.
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Roberts LJ, Lamont EG, Lim I, Sabesan S, Barrett C. Telerheumatology: an idea whose time has come. Intern Med J 2013; 42:1072-8. [PMID: 22931307 DOI: 10.1111/j.1445-5994.2012.02931.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Australia is a vast country with one-third of the population living outside capital cities. Providing specialist rheumatologist services to regional, rural and remote Australians has generally required expensive and time-consuming travel for the patient and/or specialist. As a result, access to specialist care for remote Australians is poor. Rheumatoid arthritis is a common disease, but like many rheumatic diseases, it is complex to treat. Time-dependent joint damage and disability occur unless best evidence care is implemented. The relatively poor access to rheumatologist care allotted to nonmetropolitan Australians therefore represents a significant cause of potentially preventable disability in Australia. Telehealth has the potential to improve access to specialist rheumatologists for patients with rheumatoid arthritis and other rheumatic diseases, thereby decreasing the burden of disability caused by these diseases. Advances in videoconferencing technology, the national broadband rollout and recent Federal government financial incentives have led to a heightened interest in exploring the use of this technology in Australian rheumatology practice. This review summarises the current evidence base, outlines telehealth's strengths and weaknesses in managing rheumatic disease, and discusses the technological, medicolegal and financial aspects of this model of care. A mixed model offering both face-to-face and virtual consultations appears to be the best option, as it can overcome the barriers to accessing care posed by distance while also mitigating the risks of virtual consultation.
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Roberts LJ, LaMont EG, Lim I, Sabesan S, Barrett C. Author reply. Intern Med J 2013; 43:469. [DOI: 10.1111/imj.12099] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2013] [Accepted: 02/05/2013] [Indexed: 11/29/2022]
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Barrett C, Bisset K, Chandan S, Chen J, Chungbaek Y, Eubank S, Evrenosoğlu Y, Lewis B, Lum K, Marathe A, Marathe M, Mortveit H, Parikh N, Phadke A, Reed J, Rivers C, Saha S, Stretz P, Swarup S, Thorp J, Vullikanti A, Xie D. PLANNING AND RESPONSE IN THE AFTERMATH OF A LARGE CRISIS: AN AGENT-BASED INFORMATICS FRAMEWORK *. PROCEEDINGS OF THE ... WINTER SIMULATION CONFERENCE. WINTER SIMULATION CONFERENCE 2013; 2013:1515-1526. [PMID: 25580055 PMCID: PMC4287985 DOI: 10.1109/wsc.2013.6721535] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We present a synthetic information and modeling environment that can allow policy makers to study various counter-factual experiments in the event of a large human-initiated crisis. The specific scenario we consider is a ground detonation caused by an improvised nuclear device in a large urban region. In contrast to earlier work in this area that focuses largely on the prompt effects on human health and injury, we focus on co-evolution of individual and collective behavior and its interaction with the differentially damaged infrastructure. This allows us to study short term secondary and tertiary effects. The present environment is suitable for studying the dynamical outcomes over a two week period after the initial blast. A novel computing and data processing architecture is described; the architecture allows us to represent multiple co-evolving infrastructures and social networks at a highly resolved temporal, spatial, and individual scale. The representation allows us to study the emergent behavior of individuals as well as specific strategies to reduce casualties and injuries that exploit the spatial and temporal nature of the secondary and tertiary effects. A number of important conclusions are obtained using the modeling environment. For example, the studies decisively show that deploying ad hoc communication networks to reach individuals in the affected area is likely to have a significant impact on the overall casualties and injuries.
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Guild S, Stehlin E, Malpas S, Barrett C. Left Ventricular Pressure (LVP) Measurement in Conscious Small Animals via Telemetry. Heart Lung Circ 2012. [DOI: 10.1016/j.hlc.2012.08.035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Pinkham M, Barrett C. Sympathetic Activation after Myocardial Infarction in the Rat: Role of the Arterial Baroreflex, Cardiac Afferent Reflexes and Sex. Heart Lung Circ 2012. [DOI: 10.1016/j.hlc.2012.08.038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Bowes MJ, Ings NL, McCall SJ, Warwick A, Barrett C, Wickham HD, Harman SA, Armstrong LK, Scarlett PM, Roberts C, Lehmann K, Singer AC. Nutrient and light limitation of periphyton in the River Thames: implications for catchment management. THE SCIENCE OF THE TOTAL ENVIRONMENT 2012; 434:201-12. [PMID: 22035560 DOI: 10.1016/j.scitotenv.2011.09.082] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2011] [Revised: 09/01/2011] [Accepted: 09/07/2011] [Indexed: 05/07/2023]
Abstract
Soluble reactive phosphorus (SRP) concentrations in the River Thames, south east England, have significantly decreased from an annual maximum of 2100 μg l(-1) in 1997 to 344 in 2010, primarily due to the introduction of phosphorus (P) removal at sewage treatment works within the catchment. However, despite this improvement in water quality, phytoplankton biomass in the River Thames has greatly increased in recent years, with peak chlorophyll concentrations increasing from 87 μg l(-1) in the period 1997 to 2002, to 328 μg l(-1) in 2009. A series of within-river flume mesocosm experiments were performed to determine the effect of changing nutrient concentrations and light levels on periphyton biomass accrual. Nutrient enrichment experiments showed that phosphorus, nitrogen and silicon were not limiting or co-limiting periphyton growth in the Thames at the time of the experiment (August-September 2010). Decreasing ambient SRP concentration from 225 μg l(-1) to 173 μg l(-1) had no effect on periphyton biomass accrual rate or diatom assemblage. Phosphorus limitation became apparent at 83 μg SRP l(-1), at which point a 25% reduction in periphyton biomass was observed. Diatom assemblage significantly changed when the SRP concentration was reduced to 30 μg l(-1). Such stringent phosphorus targets are costly and difficult to achieve for the River Thames, due to the high population density and intensive agriculture within the Thames basin. Reducing light levels by shading reduced the periphyton accrual rate by 50%. Providing shading along the River Thames by planting riparian tree cover could be an effective measure to reduce the risk of excessive algal growth. If the ecology of the Thames is to reach the WFD's "good ecological status", then both SRP concentration reductions (probably to below 100 μg l(-1)) and increased shading will be required.
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Wight RG, Aneshensel CS, Barrett C, Ko M, Chodosh J, Karlamangla AS. Urban neighbourhood unemployment history and depressive symptoms over time among late middle age and older adults. J Epidemiol Community Health 2012; 67:153-8. [PMID: 22918896 DOI: 10.1136/jech-2012-201537] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
BACKGROUND Little is known about how a neighbourhood's unemployment history may set the stage for depressive symptomatology. This study examines the effects of urban neighbourhood unemployment history on current depressive symptoms and subsequent symptom trajectories among residentially stable late middle age and older adults. Contingent effects between neighbourhood unemployment and individual-level employment status (ie, cross-level interactions) are also assessed. METHODS Individual-level survey data are from four waves (2000, 2002, 2004 and 2006) of the original cohort of the nationally representative US Health and Retirement Study. Neighbourhoods are operationalised with US Census tracts for which historical average proportion unemployed between 1990 and 2000 and change in proportion unemployed between 1990 and 2000 are used to characterise the neighbourhood's unemployment history. Hierarchical linear regressions estimate three-level (time, individual and neighbourhood) growth models. RESULTS Symptoms in 2000 are highest among those residing in neighbourhoods characterised by high historical average unemployment beginning in 1990 and increasing unemployment between 1990 and 2000, net of a wide range of socio-demographic controls including individual-level employment status. These neighbourhood unemployment effects are not contingent upon individual-level employment status in 2000. 6-year trajectories of depressive symptoms decrease over time on average but are not significantly influenced by the neighbourhood's unemployment history. CONCLUSIONS Given the current US recession, future studies that do not consider historical employment conditions may underestimate the mental health impact of urban neighbourhood context. The findings suggest that exposure to neighbourhood unemployment earlier in life may be consequential to mental health later in life.
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Eadsforth T, Grewal I, Barrett C, Pillay R. Management and Outcomes of Intentional Durotomies. J Neurol Surg A Cent Eur Neurosurg 2012. [DOI: 10.1055/s-0032-1316241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Bazzano A, Zeldin A, Schuster E, Barrett C, Lehrer D. Vaccine-related beliefs and practices of parents of children with autism spectrum disorders. AMERICAN JOURNAL ON INTELLECTUAL AND DEVELOPMENTAL DISABILITIES 2012; 117:233-242. [PMID: 22716265 DOI: 10.1352/1944-7558-117.3.233] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Although the assertion of a link between vaccines and autism has been scientifically rejected, the theory continues to be popular and may influence the attitudes of parents of children with autism spectrum disorders. The authors sought to assess how often parents change or discontinue their child's vaccine schedule after autism spectrum disorder diagnosis and whether beliefs about the etiology of autism affect their decision to do so. The authors surveyed 197 (43%) of 460 eligible parents of children under 18 years of age with autism spectrum disorders who were enrolled in a state-funded agency that provides services to those with developmental disabilities in western Los Angeles County. Half of the parents discontinued or changed vaccination practices, and this was associated with a belief that vaccines contributed to autism spectrum disorders, indicating a potential subset of undervaccinated children. Educational tools should be designed to assist physicians when talking to parents of children with autism spectrum disorders about vaccination.
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Dahab R, Barrett C, Pillay R, De Matas M. Anterior thigh compartment syndrome after prone positioning for lumbosacral fixation. EUROPEAN SPINE JOURNAL : OFFICIAL PUBLICATION OF THE EUROPEAN SPINE SOCIETY, THE EUROPEAN SPINAL DEFORMITY SOCIETY, AND THE EUROPEAN SECTION OF THE CERVICAL SPINE RESEARCH SOCIETY 2012; 21 Suppl 4:S554-6. [PMID: 22481550 DOI: 10.1007/s00586-012-2282-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2011] [Revised: 02/23/2012] [Accepted: 03/14/2012] [Indexed: 12/28/2022]
Abstract
We report a case of a patient who developed anterior thigh compartment syndrome after being positioned prone for instrumented lumbar spine surgery. Although rare, clinicians should be aware that compartment syndrome is a possible complication of spinal surgery.
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Eadsforth T, Niven S, Barrett C. The utility of myelography in lumbar canal stenosis. Br J Neurosurg 2012; 26:578-9. [DOI: 10.3109/02688697.2012.664297] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Beinart R, Danik S, Palacios I, Barrett C, Inglessis I, Agnihotri A, Passeri J. Ventricular tachycardia following trans-apical aortic valve replacement. Europace 2011; 14:450-2. [DOI: 10.1093/europace/eur324] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Marathe A, Lewis B, Barrett C, Chen J, Marathe M, Eubank S, Ma Y. Comparing effectiveness of top-down and bottom-up strategies in containing influenza. PLoS One 2011; 6:e25149. [PMID: 21966439 PMCID: PMC3178616 DOI: 10.1371/journal.pone.0025149] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2011] [Accepted: 08/29/2011] [Indexed: 11/22/2022] Open
Abstract
This research compares the performance of bottom-up, self-motivated behavioral interventions with top-down interventions targeted at controlling an “Influenza-like-illness”. Both types of interventions use a variant of the ring strategy. In the first case, when the fraction of a person's direct contacts who are diagnosed exceeds a threshold, that person decides to seek prophylaxis, e.g. vaccine or antivirals; in the second case, we consider two intervention protocols, denoted Block and School: when a fraction of people who are diagnosed in a Census Block (resp., School) exceeds the threshold, prophylax the entire Block (resp., School). Results show that the bottom-up strategy outperforms the top-down strategies under our parameter settings. Even in situations where the Block strategy reduces the overall attack rate well, it incurs a much higher cost. These findings lend credence to the notion that if people used antivirals effectively, making them available quickly on demand to private citizens could be a very effective way to control an outbreak.
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Grimminger PP, Shi M, Barrett C, Lebwohl D, Danenberg KD, Brabender J, Vigen CLP, Danenberg PV, Winder T, Lenz HJ. TS and ERCC-1 mRNA expressions and clinical outcome in patients with metastatic colon cancer in CONFIRM-1 and -2 clinical trials. THE PHARMACOGENOMICS JOURNAL 2011; 12:404-11. [PMID: 21788964 DOI: 10.1038/tpj.2011.29] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
To validate established cutoff levels of thymidylate synthase (TS) and excision repair cross-complementing (ERCC-1) intratumoral mRNA expressions in tumor samples from metastatic colorectal cancer (mCRC) patients treated with PTK787/ZK222584 (PTK/ZK). From 122 samples of patients with mCRC enrolled in CONFIRM-1 (Colorectal Oral Novel Therapy for the Inhibition of Angiogenesis and Retarding of Metastases) or CONFIRM-2, mRNA was isolated of microdissected formalin-fixed paraffin-embedded samples and quantitated using TaqMan-based technology. Existing TS and ERCC-1 cutoff levels were tested for their prognostic value in first-line and second-line therapy. TS expression was associated with overall survival (OS) in first-line, but not second-line therapy. ERCC-1 was associated with OS in patients treated with first-line and second-line FOLFOX4. In first-line FOLFOX4, combination of high TS and/or high ERCC-1 was associated with shorter OS. A correlation was observed between ERCC-1 expression and benefit from PTK/ZK+FOLFOX4 treatment. TS and ERCC-1 expression is associated with clinical outcome in mCRC. Baseline TS and ERCC-1 levels may allow the selection of patients who benefit from FOLFOX4 chemotherapy.
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Coss C, Barrett C, Kim J, Li C, Dalton JT, Veverka KA. Importance of CYP2D6 metabolism in the in vitro antiestrogenic activity of toremifene and tamoxifen. J Clin Oncol 2011. [DOI: 10.1200/jco.2011.29.15_suppl.e13067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Nuciforo P, Burzykowski T, Lambertini C, Gardner H, Liu WH, Lee B, Barzaghi-Rinaudo P, Rheinhardt J, Barrett C, Linnartz R, Dugan M, Hackl W, Eiermann W, Pienkowski T, Crown J, Robert N, Pawlicki M, Martin M, Finn R, Lindsay MA, Slamon D, Press M. Abstract P3-10-24: Fibroblast Growth Factor Receptor 1 Amplification and Overexpression in Breast Cancer Tissue Microarrays Using Chromogenic In Situ Hybridization and Immunohistochemistry. Cancer Res 2010. [DOI: 10.1158/0008-5472.sabcs10-p3-10-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Fibroblast growth factor receptors 1 (FGFR1) belongs to a subfamily of receptor tyrosine kinases (RTKs), which are involved in proliferation and apoptosis. FGFR1 amplification and mRNA overexpression occurs in ∼10% of breast cancers and has been associated with poor outcome. However, studies assessing FGFR1 amplification and protein overexpression in a large collection of breast tumors are lacking. In this prospective, we examined a series of primary breast cancers samples derived from the BCIRG trials assembled into 15 tissue microarrays. FGFR1 gene amplification was studied using chromogenic in situ hybridization (CISH) and evaluated with respect to association with level of protein expression and clinicopathological parameters. FGFR1 gene amplification was significantly associated with high protein levels as determined by immunohistochemistry (P<0.0001, 3294 pts with available matched CISH and IHC records). Overall, the incidence of FGFR1 amplification found was 9.7% (160 out of 1646 pts. with available clinicopathological records) without a statistically significant difference between Her2- (78 out 720 pts., 11%) and Her2+ (82 out of 926 pts., 9%) cancers. In both cohorts, the hormone receptor-positive (ER+/PR+) cancers showed statistically significant higher levels of FGFR1 amplification compared to hormone receptor-negative tumors. In the analysis of the association of FGFR1 and the presence of PIK3CA mutations, the incidence of FGFR1 amplificationwas greatly reduced in mutant vs. wt PI3KCA tumors. In these cohorts, a clear relationship between FGFR1 amplification status and clinical outcome was not detected. Data from this large study confirms recently reported incidences of FGFR1 amplification in breast cancer and shows for the first time an association between FGFR1 gene amplification and protein overexpression. Moreover, the lower incidence of FGFR1 amplification in PIK3CA mutated cancers suggests that these are largely exclusive molecular events that could benefit from different targeted therapies.
Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P3-10-24.
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Eubank S, Barrett C, Beckman R, Bisset K, Durbeck L, Kuhlman C, Lewis B, Marathe A, Marathe M, Stretz P. Detail in network models of epidemiology: are we there yet? JOURNAL OF BIOLOGICAL DYNAMICS 2010; 4:446-55. [PMID: 20953340 PMCID: PMC2953274 DOI: 10.1080/17513751003778687] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Network models of infectious disease epidemiology can potentially provide insight into how to tailor control strategies for specific regions, but only if the network adequately reflects the structure of the region's contact network. Typically, the network is produced by models that incorporate details about human interactions. Each detail added renders the models more complicated and more difficult to calibrate, but also more faithful to the actual contact network structure. We propose a statistical test to determine when sufficient detail has been added to the models and demonstrate its application to the models used to create a synthetic population and contact network for the USA.
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Solth A, Barrett C, Holliman D, Mitchell P. Chiari malformation in female monozygotic twins. Br J Neurosurg 2010; 24:607-8. [PMID: 20649405 DOI: 10.3109/02688697.2010.495173] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
We describe the cases of female monozygotic twins who presented almost synchronously with symptomatic Chiari malformation type I. Both were successfully treated with foramen magnum decompression. We analyse these findings in the context of previously reported cases and discuss the genetic implications.
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Cao J, Gu Y, Fan W, Chen LQ, Ogletree DF, Chen K, Tamura N, Kunz M, Barrett C, Seidel J, Wu J. Extended mapping and exploration of the vanadium dioxide stress-temperature phase diagram. NANO LETTERS 2010; 10:2667-2673. [PMID: 20586406 DOI: 10.1021/nl101457k] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Single-crystal micro- and nanomaterials often exhibit higher yield strength than their bulk counterparts. This enhancement is widely recognized in structural materials but is rarely exploited to probe fundamental physics of electronic materials. Vanadium dioxide exhibits coupled electronic and structural phase transitions that involve different structures existing at different strain states. Full understanding of the driving mechanism of these coupled transitions necessitates concurrent structural and electrical measurements over a wide phase space. Taking advantages of the superior mechanical property of micro/nanocrystals of VO(2), we map and explore its stress-temperature phase diagram over a phase space that is more than an order of magnitude broader than previously attained. New structural and electronic aspects were observed crossing phase boundaries at high-strain states. Our work shows that the actively tuning strain in micro/nanoscale electronic materials provides an effective route to investigate their fundamental properties beyond what can be accessed in their bulk counterpart.
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Rahbar L, Moxley G, Carleton D, Barrett C, Brannen J, Thacker L, Waterhouse EJ, Roberts WN. Correlation of rheumatology subspecialty choice and identifiable strong motivations, including intellectual interest. Arthritis Care Res (Hoboken) 2010; 62:1796-804. [PMID: 20597115 DOI: 10.1002/acr.20284] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2010] [Accepted: 06/24/2010] [Indexed: 11/06/2022]
Abstract
OBJECTIVE To describe motivations correlating with subspecialty choices, particularly rheumatology. METHODS A total of 179 respondents answered queries about various aspects affecting specialty and subspecialty choice with ordinal ratings of importance. Likert scale response data were analyzed to determine independent predictors of being a rheumatology fellow. Multivariate logistic regression analyses were used to develop models predicting rheumatology fellowship. Factor analysis methods to condense the individual responses into fewer underlying variables or factors were employed. RESULTS While every group ranked intellectual interest as more important than all other responses, its score in the rheumatology fellow group was significantly higher than that in the medical student group. A model using 4 composite variables based on prior literature did not fit well. Exploratory factor analysis identified 5 underlying motivations, which were designated as time, money, external constraints, practice content, and academics. All motivations except money were statistically significant, with the rheumatology fellow group attributing greater importance than medical students to time, practice content, and academics, and lesser importance than medical students to external constraints. CONCLUSION Values and motivations leading toward rheumatology subspecialty choice can be traced to identifiable factors. Intellectual interest appears to be split between 2 distinct significant variables: practice content and academics. Time or controllable lifestyle, external constraints, practice content, and academic issues appear to be important influences on the choice of rheumatology fellowship. Such variables appear to reflect underlying values and motivations.
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Barrett C. The Doctor. West J Med 2010. [DOI: 10.1136/bmj.b5660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Barrett C, Bisset K, Leidig J, Marathe A, Marathe MV. An Integrated Modeling Environment to Study the Co-evolution of Networks, Individual Behavior and Epidemics. AI MAG 2010. [DOI: 10.1609/aimag.v31i1.2283] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
We discuss an interaction-based approach to study the coevolution between socio-technical networks, individual behaviors, and contagion processes on these networks. We use epidemics in human population as an example of this phenomenon. The methods consist of developing synthetic yet realistic national-scale networks using a first principles approach. Unlike simple random graph techniques, these methods combine real world data sources with behavioral and social theories to synthesize detailed social contact (proximity) networks. Individual-based models of within-host disease progression and inter-host transmission are then used to model the contagion process. Finally, models of individual behaviors are composed with disease progression models to develop a realistic representation of the complex system in which individual behaviors and the social network adapt to the contagion. These methods are embodied within Simdemics – a general purpose modeling environment to support pandemic planning and response. Simdemics is designed specifically to be scalable to networks with 300 million agents – the underlying algorithms and methods in Simdemics are all high-performance computing oriented methods. New advances in network science, machine learning, high performance computing, data mining and behavioral modeling were necessary to develop Simdemics. Simdemics is combined with two other environments, Simfrastructure and Didactic, to form an integrated cyberenvironment. The integrated cyber-environment provides the end-user flexible and seamless Internet based access to Simdemics. Service-oriented architectures play a critical role in delivering the desired services to the end user. Simdemics, in conjunction with the integrated cyber-environment, has been used in over a dozen user defined case studies. These case studies were done to support specific policy questions that arose in the context of planning the response to pandemics (e.g., H1N1, H5N1) and human initiated bio-terrorism events. These studies played a crucial role in the continual development and improvement of the cyber-environment.
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