bluuebunny/crossref_metadata_2025_split huggingface dataset:
Conditional Transformation Models
Authors: Hothorn Torsten , Kneib Thomas , Bühlmann Peter 
Published: March 2013

SummaryThe ultimate goal of regression analysis is to obtain information about the conditional distribution of a response given a set of explanatory variables. This goal is, however, seldom achieved because most established regression models estimate only the conditional mean as a function of the explanatory variables and assume that higher moments are not affected by the regressors. The underlying reason for such a restriction is the assumption of additivity of signal and noise. We propose to relax this common assumption in the framework of transformation models. The novel class of semiparametric regression models proposed herein allows transformation functions to depend on explanatory variables. These transformation functions are estimated by regularized optimization of scoring rules for probabilistic forecasts, e.g. the continuous ranked probability score. The corresponding estimated conditional distribution functions are consistent. Conditional transformation models are potentially useful for describing possible heteroscedasticity, comparing spatially varying distributions, identifying extreme events, deriving prediction intervals and selecting variables beyond mean regression effects. An empirical investigation based on a heteroscedastic varying-coefficient simulation model demonstrates that semiparametric estimation of conditional distribution functions can be more beneficial than kernel-based non-parametric approaches or parametric generalized additive models for location, scale and shape.
In vitro study of the effect of dog food on the adsorptive capacity of activated charcoal
Authors: Wilson Helen E. , Humm Karen R. 
Published: March 2013

AbstractObjectiveTo evaluate the effect of dog food on the adsorptive capacity of activated charcoal.DesignIn vitro laboratory study.SettingUniversity veterinary teaching hospital.AnimalsNone.InterventionsNone.Materials and MethodsA fixed quantity of acetaminophen (50 mg) was added to a fixed quantity of activated charcoal (1 g), mixed with varying amounts of dog food (2–14 g). The admixture was agitated for 5 minutes, incubated at 38.5°C for 1 hour and then centrifuged for 30 minutes. The concentration of residual, nonadsorbed acetaminophen in the supernatant was quantitatively assayed by reverse phase high‐pressure liquid chromatography with ultraviolet detection. Data were tested by linear regression analysis and statistical significance was set atP< 0.05.Measurements and Main ResultsA statistically significant reduction in the adsorptive capacity of activated charcoal was demonstrated with increasing amounts of dog food (R2= 0.54;P= 0.0018). However, all measurements of residual acetaminophen were less than 100 mg/L, representing a reduction in acetaminophen concentration of more than 98.6%.ConclusionsThe addition of dog food to activated charcoal reduces its total adsorptive capacity for acetaminophen. However, this reduction in adsorptive capacity is unlikely to be clinically significant in the presence of both the formulation of dog food and the ratio of dog food to charcoal used in this study.
Prospective multicentre study of the effect of voluntary plasmapheresis on plasma cholesterol levels in donors
Authors: Rosa‐Bray M. , Wisdom C. , Wada S. , Johnson B. R. , Grifols‐Roura V. , Grifols‐Lucas V. 
Published: March 2013

Background and ObjectivesLDL apheresis is used to treat patients with familial hypercholesterolaemia, and low‐volume plasmapheresis for plasma donation may similarly lower cholesterol levels in some donors. This study was designed to assess the effect of plasmapheresis on total, LDL and HDL cholesterol levels in a plasma donor population.Materials and MethodsThis was a prospective, unblinded longitudinal cohort study in which a blood sample was obtained for analysis before each donation. Data from 663 donors were analysed using a multivariable repeated measures regression model with a general estimating equations approach with changes in cholesterol as the primary outcome measure.ResultsThe model predicted a significant decrease in total and LDL cholesterol for both genders and all baseline cholesterol levels (P < 0·01). The greatest total cholesterol decreases (women, −46·8 mg/dL; men, −32·2 mg/dL) were associated with high baseline levels and 2–4 days between donations. Small but statistically significant increases (P ≤ 0·01) in HDL cholesterol were predicted for donors with low baseline levels.ConclusionsThese results suggest that, in donors with elevated baseline cholesterol levels, total and LDL cholesterol levels may decrease during routine voluntary plasmapheresis.
Paramedic perceptions of the feasibility and practicalities of prehospital clinical trials: a questionnaire survey
Authors: Hargreaves Kate , Goodacre Steve , Mortimer Peter 
Published: March 2013

BackgroundClinical trials are required to strengthen the evidence base for prehospital care. This questionnaire study aimed to explore paramedics’ perceptions of prehospital research and barriers to conducting prehospital clinical trials.MethodsA self-completed questionnaire was developed to explore paramedic perceptions and barriers to undertaking prehospital trials based upon a review of existing research and semistructured qualitative interviews with five paramedics. The questionnaire was distributed by ‘research champions’ to 300 paramedics at randomly selected ambulance stations in Yorkshire.ResultsResponses were received from 96/300 participants (32%). Interest in clinical trials was reported, but barriers were recognised, including perceptions of poor knowledge and limited use of evidence, that conducting research is not a paramedics’ responsibility, limited support for involvement in trials, concerns about the practicalities of randomisation and consent, and time pressures. No association was found between training route and perceived understanding of trials (p=0.263) or feeling that involvement in trials was a professional responsibility (p=0.838). Previous involvement in prehospital research was not associated with opinions on importance of an evidence base (p=0.934) or gaining consent (p=0.329). The number of years respondents had been practicing was not associated with opinions on personal experience versus scientific evidence (p=0.582) or willingness to receive training for clinical trials (p=0.111). However, the low response rate limited the power of the study to detect potential associations.ConclusionsParamedics reported interest and understanding of research, but a number of practical and ethical barriers were recognised that need to be addressed if prehospital clinical trials are to increase.
THE ONSET OF BIFURCATIONS IN THE FORCED DUFFING EQUATION WITH DAMPING
Authors: STEFANESCU ION SABBA 
Published: March 2013

The paper presents a complete description of the periodic solutions of the Duffing equation: [Formula: see text] for large values of the forcing Γ and the damping Δ. It contains a proof that the equation admits of an infinite sequence of bifurcation curves in the Γ - Δ plane, alternately of the saddle-node and odd periodic — simply 2π-periodic type, whose maxima lie at large Γ along the line: [Formula: see text] where C(Γ) has a finite limit as Γ → ∞. The positions of the maxima are interlaced in asymptotically equal intervals of Γ1/3, with a spacing of 1.403 units. For Δ > Δc(Γ), the Duffing equation admits of a unique periodic solution if Γ is high enough. These results are obtained by showing that the half-period Poincaré map offered by the Duffing equation is asymptotically equivalent to a map of a circle into itself, according to: [Formula: see text] where χ is an angular variable and β, Σ depend on Γ, Δ. The numerical constants appearing in the circle map and its corrections are determined in the limit Γ → ∞ by a parameter-free boundary layer equation and its variation.
Burden of Intracranial Steno-Occlusive Lesions on Initial Computed Tomography Angiography Predicts Poor Outcome in Patients With Acute Stroke
Authors: Lau Alexander Y. , Wong Ka-sing Lawrence , Lev Michael , Furie Karen , Smith Wade , Kim Anthony S. 
Published: March 2013

Background and Purpose—
Computed tomography angiography is an accurate noninvasive method to diagnose intracranial steno-occlusive disease (ICAD) at initial presentation for stroke. We aimed to identify features of computed tomography angiography associated with unfavorable outcome.

Methods—
We identified patients with ICAD in the Screening Technology and Outcomes Project in Stroke Study, a prospective imaging-based study of stroke outcomes, in consecutive patients with ischemic stroke or transient ischemic attack (TIA) presenting to 2 academic medical centers. All patients underwent computed tomography angiography, which were graded by 2 neuroradiologists independently. Univariate and multiple logistic regression was used to evaluate predictors of favorable outcome at 6 months, defined as a modified Rankin Scale ≤2.

Results—

Among 539 patients that met study entry criteria, ICAD was identified in 212 patients (39%); 116 patients (22%) had concurrent extraintracranial lesions, and 66 patients (12%) had multiple sites of ICAD. Patients with ICAD had more severe stroke (median National Institutes of Health Stroke Scale, 9 versus 3;
P
<0.001), worse outcomes at 6 months (modified Rankin Scale, 0–2; 57% versus 73%;
P
<0.001), and higher mortality (18% versus 8%;
P
=0.001). In the multivariate model, age (odds ratio [OR], 0.75 per decade; 95% confidence interval [CI], 0.65–0.87), female sex (OR, 0.49; 95% CI, 0.32–0.73), multiple sites of ICAD (OR, 0.53; 95% CI, 0.29–0.97), complete occlusion (OR, 0.42; 95% CI, 0.25–0.72), and concurrent extraintracranial lesions (OR, 0.51; 95% CI, 0.31–0.84) negatively predicted favorable outcome.

Conclusions—
Findings of multiple sites of ICAD from computed tomography angiography, concurrent extraintracranial lesions, and complete occlusion are independent predictors of unfavorable outcome at 6 months.
Early Prediction of Delayed Cerebral Ischemia After Subarachnoid Hemorrhage
Authors: de Rooij Nicolien K. , Greving Jacoba P. , Rinkel Gabriel J.E. , Frijns Catharina J.M. 
Published: March 2013

Background and Purpose—
To develop and validate a risk chart for prediction of delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage based on admission characteristics.

Methods—
For derivation of the risk chart, we studied data from 371 prospectively collected consecutive subarachnoid hemorrhage patients with a confirmed aneurysm admitted between 1999 and 2007. For its validation we similarly studied 255 patients admitted between 2007 and 2009. The predictive value of admission characteristics was tested in logistic regression models with delayed cerebral ischemia–related infarction as primary outcome. Procedure-related infarctions were not included. Performance of the models was tested by discrimination and calibration. On the basis of these models, a risk chart was developed for application in clinical practice.

Results—
The strongest predictors were clinical condition on admission, amount of blood on computed tomography (both cisternal and intraventricular) and age. A model that combined these 4 predictors had an area under the receiver operating characteristic curve of 0.63 (95% confidence interval, 0.57–0.69). This model improved little by including current smoking and hyperglycemia on admission (area under the receiver operating characteristic curve, 0.65; 95% confidence interval, 0.59–0.71). The risk chart predicted risks of delayed cerebral ischemia–related infarction varying from 12% to 61%. Both low risk (<20% risk) and high risk (>40% risk) were predicted in ≈20% of the patients. Validation confirmed that the discriminative ability was adequate (area under the receiver operating characteristic curve, 0.69; 95% confidence interval, 0.61–0.77).

Conclusions—
Absolute risks of delayed cerebral ischemia–related infarction can be reliably estimated by a simple risk chart that includes clinical condition on admission, amount of blood on computed tomography (both cisternal and intraventricular), and age.
A new species of Chasmatopontius (Copepoda, Siphonostomatoida, Dirivultidae) from a hydrothermal vent field in the Tofua Arc, southwestern Pacific Ocean
Authors: Kim Se-Joo , Kim Il-Hoi 
Published: March 2013

A new species of siphonostomatoid copepod is described from a hydrothermal vent in the Tofua Arc of the southwestern Pacific at a depth of 1018 m. Chasmatopontius inflatus sp. nov. (Copepoda, Siphonostomatoida, Dirivultidae) is defined and illustrated from specimens isolated from washings of invertebrates including gastropods, bivalves, and crustaceans collected from a hydrothermal vent field. A brief description of its habitat is presented. This new species can be distinguished from C. thescalus, the only known congener, by the greatly expanded mediodistal seta of the caudal ramus in the female, the three-segmented endopod of the female maxilliped, the smaller female body, not exceeding 0.9 mm in length, and the unique shape of the female genital double-somite.
Southern Ocean Circulation and Eddy Compensation in CMIP5 Models
Authors: Downes Stephanie M. , Hogg Andrew McC. 
Published: March 2013

Abstract
Thirteen state-of-the-art climate models from phase 5 of the Coupled Model Intercomparison Project (CMIP5) are used to evaluate the response of the Antarctic Circumpolar Current (ACC) transport and Southern Ocean meridional overturning circulation to surface wind stress and buoyancy changes. Understanding how these flows—fundamental players in the global distribution of heat, gases, and nutrients—respond to climate change is currently a widely debated issue among oceanographers. Here, the authors analyze the circulation responses of these coarse-resolution coupled models to surface fluxes. Under a future CMIP5 climate pathway where the equivalent atmospheric CO2 reaches 1370 ppm by 2100, the models robustly project reduced Southern Ocean density in the upper 2000 m accompanied by strengthened stratification. Despite an overall increase in overlying wind stress (~20%), the projected ACC transports lie within ±15% of their historical state, and no significant relationship with changes in the magnitude or position of the wind stress is identified. The models indicate that a weakening of ACC transport at the end of the twenty-first century is correlated with a strong increase in the surface heat and freshwater fluxes in the ACC region. In contrast, the surface heat gain across the ACC region and the wind-driven surface transports are significantly correlated with an increased upper and decreased lower Eulerian-mean meridional overturning circulation. The change in the eddy-induced overturning in both the depth and density spaces is quantified, and it is found that the CMIP5 models project partial eddy compensation of the upper and lower overturning cells.
Skill and Global Trend Analysis of Soil Moisture from Reanalyses and Microwave Remote Sensing
Authors: Albergel C. , Dorigo W. , Reichle R. H. , Balsamo G. , de Rosnay P. , Muñoz-Sabater J. , Isaksen L. , de Jeu R. , Wagner W. 
Published: March 2013

Abstract
In situ soil moisture measurements from 2007 to 2010 for 196 stations from five networks across the world (United States, France, Spain, China, and Australia) are used to determine the reliability of three soil moisture products: (i) a revised version of the ECMWF Interim Re-Analysis (ERA-Interim; ERA-Land); (ii) a revised version of the Modern-Era Retrospective Analysis for Research and Applications (MERRA) reanalysis from NASA (MERRA-Land); and (iii) a new, microwave-based multisatellite surface soil moisture dataset (SM-MW). Evaluation of the time series and anomalies from a moving monthly mean shows a good performance of the three products in capturing the annual cycle of surface soil moisture and its short-term variability. On average, correlations (95% confidence interval) are 0.66 (±0.038), 0.69 (±0.038), and 0.60 (±0.061) for ERA-Land, MERRA-Land, and SM-MW. The two reanalysis products also capture the root-zone soil moisture well; on average, correlations are 0.68 (±0.035) and 0.73 (±0.032) for ERA-Land and MERRA-Land, respectively. Global trends analysis for 1988–2010 suggests a decrease of surface soil moisture contents (72% of significant trends are negative, i.e., drying) for ERA-Land and an increase in surface soil moisture (59% of significant trends are positive, i.e., wetting) for MERRA-Land. As the spatial extent and fractions of significant trends in both products differ, the trend reflected in the majority of grid points within different climate classes was investigated and compared to that of SM-MW. The latter is dominated by negative significant trends (73.2%) and is more in line with ERA-Land. For both reanalysis products, trends for the upper layer of soil are confirmed in the root-zone soil moisture (first meter of soil).
Overall bolt stress optimization
Authors: Pedersen Niels L 
Published: March 2013

The state of stress in bolts and nuts with International Organization for Standardization metric thread design is examined and optimized. The assumed failure mode is fatigue, so the applied preload and the load amplitude together with the stress concentrations define the connection strength. Maximum stress in the bolt is found at the fillet under the head, at the thread start, or at the thread root. To minimize the stress concentration, shape optimization is applied. Nut shape optimization also has a positive effect on the maximum stress. The optimization results show that designing a nut, which results in a more evenly distribution of load along the engaged thread, has a limited influence on the maximum stress due to the stress concentration at the first thread root. To further reduce the maximum stress, the transition from bolt shank to the thread must be optimized. Stress reduction of up to 34% is found, still with the standard International Organization for Standardization thread. The design changes suggested in this article also have the positive advantage of reducing the joint stiffness factor. The reduction in the bolt shank directly reduces the bolt stiffness but the design change to the bolt head and the nut has the positive indirect effect of increasing the member stiffness, all leading to a smaller joint stiffness factor.
The protective effects of ω-3 fatty acids on doxorubicin-induced hepatotoxicity and nephrotoxicity in rats
Authors: Tulubas Feti , Gurel Ahmet , Oran Mustafa , Topcu Birol , Caglar Veli , Uygur Emine 
Published: March 2013

This study aims to evaluate the protective effects of ω-3 fatty acids (FAs) on doxorubicin (DOX)-induced hepatotoxicity and nephrotoxicity in rats. A total of 24 adult male Sprague Dawley rats were divided into three groups. Control group was given only saline by intragastric gavage. DOX group received DOX at the dose of 30 mg/kg intraperitoneally on day 28. DOX-ω-3 FA group was given as ω-3 FAs at the dose of 400 mg/kg daily by intragastric gavage for 30 days and received DOX at the dose of 30 mg/kg intraperitoneally on day 28. At the end of the 30-day experimental period, the serum, liver and kidney tissue specimens were taken from the animals by giving a general anesthesia. Glutathione (GSH) and malondialdehyde (MDA) levels in serum and GSH and MDA levels and superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities in liver and kidney tissues were measured spectrophotometrically. In our study, a significant increase in MDA levels was observed in rats when given a dose of DOX and a significant decrease in the levels of GSH, SOD and GSH-Px activities in serum, liver and kidney tissues was determined when compared with control group. In addition, a significant decrease in MDA levels was observed in rats when a dose of ω-3 FAs was given with DOX and a significant increase was determined in the levels of GSH, SOD and GSH-Px activities in serum, liver and kidney tissues, when compared with DOX group. We concluded that ω-3 FA had favorable effects in rat liver and kidney tissues by preventing oxidative damage.
Do Foreign Institutional Investors Reward Transparency and Disclosure
Authors: Ertuna Bengi , Tükel Ali 
Published: March 2013

Corporate governance has emerged as a leading investment criterion for institutional investors with the rise of cross-border portfolio flows, especially for markets with weak investor protection. This study provides firm-level evidence on the relationship between the level of foreign institutional investment and the transparency and disclosure performance of companies listed on the Istanbul Stock Exchange. We develop a self-constructed transparency and disclosure index, consisting of voluntary and mandatory components, and find that only voluntary disclosure is positively associated with foreign institutional investment. We conclude that firms that operate in markets with lower governance standards can indeed attract more institutional investment through better disclosure, beyond what is required by regulations. JEL Classification: G32, G34
Treatment of Myotendinous Achilles Ruptures
Authors: Ahmad Jamal , Repka Michael , Raikin Steven M. 
Published: March 2013

Background: There is scant literature regarding the treatment of myotendinous Achilles ruptures. The purpose of this study was to retrospectively examine clinical outcomes from uniform nonsurgical treatment of these injuries. Methods: Between November 2005 and May 2011, 30 patients presented with an acute, complete myotendinous Achilles rupture. The location of the Achilles injury was confirmed on magnetic resonance imaging (MRI) for all patients. All patients were treated nonsurgically, which involved 3 weeks of non-weight-bearing and then 3 weeks of progressive to full weight-bearing in an Achilles boot. Physical therapy was provided for 4 to 6 weeks after this period of immobilization. 21 patients were male and 9 were female. The patients had a mean age of 40.8 years (range, 24-54). Patients were followed an average of 40.5 months (range, 23-81). Results: Full healing of the Achilles myotendinous junction was achieved clinically in all 30 patients . All patients experienced improved function and less pain at their latest follow-up. Mean Foot and Ankle Ability Measure–Sports (FAAM-Sports) increased from 20.2% at the time of initial presentation to 95.2% at the latest follow-up ( P < .05). Mean Visual Analog Scores (VAS) of pain decreased from 8.2 at the time of initial presentation to 1.3 at latest follow-up ( P < .01). In all, 23 (76.7%), 6 (20%), and 1 (3.3%) patients rated their satisfaction as excellent, good, and fair, respectively. No patients have developed recurrent myotendinous Achilles ruptures to date. Conclusion: Nonsurgical treatment of myotendinous Achilles ruptures results in a high rate of myotendinous healing with improved patient function and pain relief. Level of Evidence: Level IV, retrospective case series.