bluuebunny/crossref_metadata_2025_split huggingface dataset:
Relationship of donor variables and graft dimension on biomechanical performance of femoral ring allograft
Authors: Hart Robert A. , Daniels Alan H. , Bahney Timothy , Tesar Jeremy , Sales Jonathan Rafe , Bay Brian 
Published: May 2011

AbstractStructural femoral ring allograft is commonly used in interbody spinal arthrodesis. Fractures of implanted femoral ring allograft have been reported. Data to guide donor screening and tissue processing by allograft tissue banks for factors that affect graft strength are incomplete. Fresh frozen human femora from 34 cadaveric donors were sectioned into ten 20‐mm thick specimens. Bone mineral density (BMD), donor age, and graft dimensions were recorded for each specimen. Three hundred twenty‐seven specimens were tested in quasi‐static axial compression. Linear regression models compared load to failure with BMD, sex‐specific donor age, minimum/maximum cortical wall thickness, and minimum/maximum outer ring diameter. Correlations between minimum and maximum cortical wall thickness and load to failure were significant (r = 0.73, p < 0.001 and r = 0.74, p < 0.001, respectively). BMD showed a weaker negative correlation with load to failure (r = −0.11, p = 0.05). Correlations between load to failure and minimum and maximum outer ring diameter and age (r = 0.06, p = 0.31) were not significant. We found that the minimum and maximum cortical wall thicknesses of femoral ring allograft are strongly correlated with the axial compressive load to failure of the graft. Other tested parameters did not prove to be effective predictors of resistance to axial loading. © 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 29:1840–1845, 2011
Palaeoproductivity evolution in the centre of the western Pacific warm pool during the last 250 ka
Authors: Li Tiegang , Zhao Jingtao , Nan Qingyun , Sun Rongtao , Yu Xinke 
Published: May 2011

AbstractTo reconstruct the palaeoproductivity evolution history of the centre of the western Pacific warm pool (WPWP) over the last 250 ka, multi‐proxies were analysed in sediment core WP7 recovered from the Ontong–Java Plateau. Palaeoproductivity evolution at the centre of the WPWP during the last 250 ka is closely related to glacial–interglacial cycles and the insolation controlled by precession. The glacial higher primary productivity relative to the interglacial conditions could have resulted from both thermocline shoaling associated with persistent El Niňo‐like conditions and the increased influx of dust resulting from intensified winter monsoon together with important changes in the thermocline. The minimum primary productivity values during the last three terminations could be resulted from deglacial thermocline deepening and intensified stratification associated with persistent La Niña‐like conditions, and the concurrent Neogloboquadrina dutertrei δ13C minimum events probably reflect the chemical signatures of Subantarctic Mode Water and Antarctic Intermediate Water. In addition, primary productivity values are also controlled by the thermocline variations resulting from El Niño/La Niña‐Southern Oscillation processes responding to precession forcing, and lead the δ18O by about 4 ka. The 33.1 ka, 19 ka and “half‐precession” periods are prominent in the palaeoproductivity records. Copyright © 2011 John Wiley & Sons, Ltd.
Poorly differentiated adenocarcinoma arising from a cervical bronchial cyst
Authors: Calzada Audrey P. , Wu Winnie , Salvado Amanda R. , Lai Chi K. , Berke Gerald S. 
Published: May 2011

AbstractBronchogenic cysts with malignant change are rarely reported. We describe a case of poorly differentiated adenocarcinoma arising from a cervical bronchial cyst in a patient presenting with a thyroid mass, cervical lymphadenopathy, and initial biopsy suggestive of papillary thyroid carcinoma. The clinical presentation, intraoperative findings, radiographic images, and pathology slides are presented. To our knowledge, this is the first report of a poorly differentiated adenocarcinoma arising from a bronchial cyst in the cervical region.
Bell's palsy during pregnancy: Is it associated with adverse perinatal outcome?
Authors: Katz Ariel , Sergienko Ruslan , Dior Uri , Wiznitzer Arnon , Kaplan Daniel M. , Sheiner Eyal 
Published: May 2011

AbstractObjective:To determine whether an association exists between Bell's palsy during pregnancy and adverse perinatal outcomes.Methods:A retrospective study comparing all singleton pregnancies of patients with and without Bell's palsy was conducted. Multiple logistic regression model was performed to control for confounders.Results:Out of 242,216 deliveries, 0.017% (n = 42) were diagnosed with Bell's palsy during pregnancy. Risk factors for Bell's palsy were chronic hypertension (9.5% vs. 1.5%, P < .001) and maternal obesity (7.1% vs. 0.8%, P < .001). Patients with Bell's palsy during pregnancy had higher rates of severe preeclampsia (9.5% vs. 1.1%, P < .001) and Cesarean deliveries (31.0% vs. 13.3%, P = .001) compared to the comparison group. In contrast, no significant association was documented between Bell's palsy and adverse perinatal outcomes such as low Apgar scores (<7) at 5 minutes (4.8% vs. 3.1%; P = .524) and perinatal mortality (2.4% vs. 1.4%; P = .57). Using multivariable analysis, controlling for confounders such as maternal age, fertility treatments, and ethnicity, Bell's palsy during pregnancy was significantly associated with obesity (odds ratio [OR] = 9.08 95% confidence interval [CI] 2.8–29.46; P < .001), chronic hypertension (OR = 6.69 95% CI 2.38–18.76; P < .001), and severe preeclampsia (OR = 9.46 95% CI 3.37–26.53; P < .001).Conclusions:Chronic hypertension and obesity are independent risk factors for Bell's palsy. Bell's palsy during pregnancy is significantly associated with severe preeclampsia. Nevertheless, no significant association exists between Bell's palsy and adverse perinatal outcomes.
An event of tail strike of an aircraft due to terrain‐induced wind shear at the Hong Kong International Airport
Authors: Chan P. W. 
Published: May 2011

AbstractIn the morning of 5 March 2010, an aircraft experienced tail strike when it departed from the south runway of the Hong Kong International Airport to the west. This paper documents the meteorological conditions in the tail strike event, and discusses the alerting and the forecasting aspects of the event. Based on the analysis of the aircraft manufacturer, the tail strike is believed to arise from significant wind shear (headwind loss) experienced by the aircraft. By analysing the surface and the LIDAR observations, it appears that the significant wind shear is related to disruption of the background southwesterly flow by the complex terrain near the airport. From the surface observations, there is a microscale cyclone at the western part of the south runway. The radial velocity image of the LIDAR also depicts an area of reverse flow in that region against the background southerly flow. The alerting of the wind shear based on the two wind shear alerting algorithms developed by the Hong Kong Observatory is discussed, and it turns out that the anemometer‐based wind shear algorithm could successfully capture this wind shear occurring close to the ground. On the other hand, due to geometrical constraint, the LIDAR does not pick up the headwind loss experienced by the aircraft. The forecasting of this wind shear event is considered by performing high resolution (down to a horizontal resolution of 50 m) using a mesoscale numerical weather prediction model. The simulated headwind profile at the event time is generally consistent with the aircraft data, though the headwind loss in the simulation is smaller than the reality. Together with the forecast wind gusts, it may be possible to alert the aviation weather forecaster at an earlier time about the occurrence of terrain‐induced wind shear over the south runway in this particular event. Copyright © 2011 Royal Meteorological Society
Changes in streamflow regime as indicator of upstream urbanization in a humid tropical river basin
Authors: George Celine , Jayakumar K. V. , James E. J. 
Published: May 2011

AbstractChanges in streamflow in the Meenachil river basin, Kerala, are assessed at two upstream gauging stations located at Palai and Cheripad and one downstream gauging station at Peroor to understand changes in flows due to upstream urbanization. An increase of 14% in the population and 46% in the number of housing units have been observed in the entire study area during the last two decades, indicating increase in urbanization. Time series analysis of 29 years data shows an increasing trend at Peroor at 2.8% per year for total flow and 5.2% for peak flow, which indicates the effect of urban land use. There has been a decreasing trend in the flows at 2% at the upstream gauging stations of the river basin. The frequency of occurrence of flows are observed to be increasing at Peroor due to urbanization which brings down vegetation, enhances the impervious area and contributes to fast draining of stormwater. The decrease in both the flow and its frequency of occurrence at the upstream stations are due to the increase in area under plantation crops and also the soil and water conservation works attempted in the area. Copyright © 2011 Royal Meteorological Society
The statistical pitfalls of the partially randomized preference design in non‐blinded trials of psychological interventions
Authors: Gemmell Isla , Dunn Graham 
Published: May 2011

AbstractIn a partially randomized preference trial (PRPT) patients with no treatment preference are allocated to groups at random, but those who express a preference receive the treatment of their choice. It has been suggested that the design can improve the external and internal validity of trials. We used computer simulation to illustrate the impact that an unmeasured confounder could have on the results and conclusions drawn from a PRPT. We generated 4000 observations (“patients”) that reflected the distribution of the Beck Depression Index (DBI) in trials of depression. Half were randomly assigned to a randomized controlled trial (RCT) design and half were assigned to a PRPT design. In the RCT, “patients” were evenly split between treatment and control groups; whereas in the preference arm, to reflect patient choice, 87.5% of patients were allocated to the experimental treatment and 12.5% to the control. Unadjusted analyses of the PRPT data consistently overestimated the treatment effect and its standard error. This lead to Type I errors when the true treatment effect was small and Type II errors when the confounder effect was large. The PRPT design is not recommended as a method of establishing an unbiased estimate of treatment effect due to the potential influence of unmeasured confounders. Copyright © 2011 John Wiley & Sons, Ltd.
Methods of the Pharmacological Imaging of the Cannabinoid System (PhICS) study: towards understanding the role of the brain endocannabinoid system in human cognition
Authors: van Hell Hendrika H. , Bossong Matthijs G. , Jager Gerry , Kahn René S. , Ramsey Nick F. 
Published: May 2011

AbstractVarious lines of (pre)clinical research indicate that cannabinoid agents carry the potential for therapeutic application to reduce symptoms in several psychiatric disorders. However, direct testing of the involvement of cannabinoid brain systems in psychiatric syndromes is essential for further development. In the Pharmacological Imaging of the Cannabinoid System (PhICS) study, the involvement of the endocannabinoid system in cognitive brain function is assessed by comparing acute effects of the cannabinoid agonist Δ9‐tetrahydrocannabinol (THC) on brain function between healthy controls and groups of psychiatric patients showing cognitive dysfunction. This article describes the objectives and methods of the PhICS study and presents preliminary results of the administration procedure on subjective and neurophysiological parameters. Core elements in the methodology of PhICS are the administration method (THC is administered by inhalation using a vaporizing device) and a comprehensive use of pharmacological magnetic resonance imaging (phMRI) combining several types of MRI scans including functional MRI (fMRI), Arterial Spin Labeling (ASL) to measure brain perfusion, and resting‐state fMRI. Additional methods like neuropsychological testing further specify the exact role of the endocannabinoid system in regulating cognition. Preliminary results presented in this paper indicate robust behavioral and subjective effects of THC. In addition, fMRI paradigms demonstrate activation of expected networks of brain regions in the cognitive domains of interest. The presented administration and assessment protocol provides a basis for further research on the involvement of the endocannabionoid systems in behavior and in psychopathology, which in turn may lead to development of therapeutic opportunities of cannabinoid ligands. Copyright © 2011 John Wiley & Sons, Ltd.
Smoking cessation in primary care – a randomized controlled trial of bupropione, nicotine replacements, CBT and a minimal intervention
Authors: Wittchen Hans‐Ulrich , Hoch Eva , Klotsche Jens , Muehlig Stephan 
Published: May 2011

AbstractBackground/aims: Smoking cessation has been shown to be effective in randomized controlled trials. It is unclear though, whether interventions also work in routine primary care.Methods: In 167 primary care settings we conducted a randomized four‐armed smoking cessation trial to examine the efficacy of a minimal intervention (MI; n = 81), cognitive‐behavioral therapy (CBT; n = 175), bupropion (BUP; n = 108) and nicotine replacements (NRT; n = 103). Overall, 467 current smokers were enrolled. Abstinence rates at the end of treatment (12 weeks) were 32.8% for MI patients, 34.8% for CBT, 35.3% for NRT, and 46.5% for BUP patients (ITT, intention to treat) (no differential effects). Retention rates were highest in the BUP group (59.3%) and lowest in the NRT group (50.5%). Completer findings were: MI, 56.4%; CBT, 64%; BUP, 79.3%; NRT, 69.2% (LOCF, lost to follow‐up). No serious adverse events occurred during or after the medication phase. At 12‐month follow‐up continuous abstinence rates were: BUP, 29.0%; CBT, 20.9%; NRT, 29.6%; MI, 29.6%.Conclusion: Our findings suggest that established smoking cessation treatments are effective when applied by non‐specialist primary care physicians. Our data supports a structured, multimodal treatment structure as core ingredient of successful smoking cessation in primary care. Copyright © 2011 John Wiley & Sons, Ltd.
Multiple imputation by chained equations: what is it and how does it work?
Authors: Azur Melissa J. , Stuart Elizabeth A. , Frangakis Constantine , Leaf Philip J. 
Published: May 2011

AbstractMultivariate imputation by chained equations (MICE) has emerged as a principled method of dealing with missing data. Despite properties that make MICE particularly useful for large imputation procedures and advances in software development that now make it accessible to many researchers, many psychiatric researchers have not been trained in these methods and few practical resources exist to guide researchers in the implementation of this technique. This paper provides an introduction to the MICE method with a focus on practical aspects and challenges in using this method. A brief review of software programs available to implement MICE and then analyze multiply imputed data is also provided. Copyright © 2011 John Wiley & Sons, Ltd.
Missing value imputation in longitudinal measures of alcohol consumption
Authors: Grittner Ulrike , Gmel Gerhard , Ripatti Samuli , Bloomfield Kim , Wicki Matthias 
Published: May 2011

AbstractAttrition in longitudinal studies can lead to biased results. The study is motivated by the unexpected observation that alcohol consumption decreased despite increased availability, which may be due to sample attrition of heavy drinkers. Several imputation methods have been proposed, but rarely compared in longitudinal studies of alcohol consumption. The imputation of consumption level measurements is computationally particularly challenging due to alcohol consumption being a semi‐continuous variable (dichotomous drinking status and continuous volume among drinkers), and the non‐normality of data in the continuous part. Data come from a longitudinal study in Denmark with four waves (2003–2006) and 1771 individuals at baseline. Five techniques for missing data are compared: Last value carried forward (LVCF) was used as a single, and Hotdeck, Heckman modelling, multivariate imputation by chained equations (MICE), and a Bayesian approach as multiple imputation methods. Predictive mean matching was used to account for non‐normality, where instead of imputing regression estimates, “real” observed values from similar cases are imputed. Methods were also compared by means of a simulated dataset. The simulation showed that the Bayesian approach yielded the most unbiased estimates for imputation. The finding of no increase in consumption levels despite a higher availability remained unaltered. Copyright © 2011 John Wiley & Sons, Ltd.
Assessing the performance of the short screening scale for post‐traumatic stress disorder in a large nationally‐representative survey
Authors: Bohnert Kipling M. , Breslau Naomi 
Published: May 2011

AbstractThe performance of the short screening scale for the Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM‐IV) post‐traumatic stress disorder (PTSD), has not been assessed in an independent general population sample, although it has been used in epidemiological as well as clinical research. In this report we evaluate the short screening scale in the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC), a population‐based survey of US household and group quarter residents. DSM‐IV PTSD was assessed via symptom questions in the Alcohol Use Disorder and Associated Disabilities Interview Schedule‐DSM‐IV (AUDADIS‐IV) version. Sensitivity, specificity, positive and negative predictive value, and percent correctly classified were calculated, using the interview‐based diagnosis as the standard. Replicating findings from the initial report, a score of four or more on the short screening scale identifies cases of PTSD with sensitivity of 78%, specificity of 97%, positive predictive value of 75%, and negative predictive value of 98%. The percentage of correctly classified respondents was 96%. The findings support the utility of the seven‐item scale for screening PTSD in clinical and general population samples. Copyright © 2011 John Wiley & Sons, Ltd.
Computerized home video detection for motherese may help to study impaired interaction between infants who become autistic and their parents
Authors: Mahdhaoui Ammar , Chetouani Mohamed , Cassel Raquel S. , Saint‐Georges Catherine , Parlato Erika , Laznik Marie Christine , Apicella Fabio , Muratori Filippo , Maestro Sandra , Cohen David 
Published: May 2011

AbstractAutism is a well‐defined clinical syndrome after the second year of life, but information on autism in the first two years of life is still lacking. The study of home videos has described children with autism during the first year of life as not displaying the rigid pattern typical of later symptoms. Therefore, developmental/environmental factors are claimed in addition to genetic/biological ones to explain the onset of autism during maturation. Here we describe (1) a developmental hypothesis focusing on the possible implication of motherese impoverishment during the course of parent–infant interactions as a possible co‐factor; (2) the methodological approach we used to develop a computerized algorithm to detect motherese in home videos; (3) the best configuration performance of the detector in extracting motherese from home video sequences (accuracy = 82% on speaker‐independent versus 87.5% on speaker‐dependent) that we should use to test this hypothesis. Copyright © 2011 John Wiley & Sons, Ltd.
Contributions of chemical exchange to T1ρ dispersion in a tissue model
Authors: Cobb Jared G. , Xie Jingping , Gore John C. 
Published: May 2011

AbstractVariations in T1ρ with locking‐field strength (T1ρ dispersion) may be used to estimate proton exchange rates. We developed a novel approach utilizing the second derivative of the dispersion curve to measure exchange in a model system of cross‐linked polyacrylamide gels. These gels were varied in relative composition of comonomers, increasing stiffness, and in pH, modifying exchange rates. Magnetic resonance images were recorded with a spin‐locking sequence as described by Sepponen et al. These measurements were fit to a mono‐exponential decay function yielding values for T1ρ at each locking‐field measured. These values were then fit to a model by Chopra et al. for estimating exchange rates. For low stiffness gels, the calculated exchange values increased by a factor of 4 as pH increased, consistent with chemical exchange being the dominant contributor to T1ρ dispersion. Interestingly, calculated chemical exchange rates also increased with stiffness, likely due to modified side‐chain exchange kinetics as the composition varied. This article demonstrates a new method to assess the structural and chemical effects on T1ρ relaxation dispersion with a suitable model. These phenomena may be exploited in an imaging context to emphasize the presence of nuclei of specific exchange rates, rather than chemical shifts. Magn Reson Med, 2011. © 2011 Wiley Periodicals, Inc.
Calibration and validation of TRUST MRI for the estimation of cerebral blood oxygenation
Authors: Lu Hanzhang , Xu Feng , Grgac Ksenija , Liu Peiying , Qin Qin , van Zijl Peter 
Published: May 2011

AbstractRecently, a T2‐Relaxation‐Under‐Spin‐Tagging (TRUST) MRI technique was developed to quantitatively estimate blood oxygen saturation fraction (Y) via the measurement of pure blood T2. This technique has shown promise for normalization of fMRI signals, for the assessment of oxygen metabolism, and in studies of cognitive aging and multiple sclerosis. However, a human validation study has not been conducted. In addition, the calibration curve used to convert blood T2 to Y has not accounted for the effects of hematocrit (Hct). In this study, we first conducted experiments on blood samples under physiologic conditions, and the Carr‐Purcell‐Meiboom‐Gill T2 was determined for a range of Y and Hct values. The data were fitted to a two‐compartment exchange model to allow the characterization of a three‐dimensional plot that can serve to calibrate the in vivo data. Next, in a validation study in humans, we showed that arterial Y estimated using TRUST MRI was 0.837 ± 0.036 (N=7) during the inhalation of 14% O2, which was in excellent agreement with the gold‐standard Y values of 0.840 ± 0.036 based on Pulse‐Oximetry. These data suggest that the availability of this calibration plot should enhance the applicability of T2‐Relaxation‐Under‐Spin‐Tagging MRI for noninvasive assessment of cerebral blood oxygenation. Magn Reson Med, 2011. © 2011 Wiley‐Liss, Inc.