bluuebunny/crossref_metadata_2025_split huggingface dataset:
Exploiting tail shape biases to discriminate between stable and student t alternatives
Authors: Sun Pengfei , de Vries Casper G. 
Published: May 2018

SummaryThe nonnormal stable laws and Student t distributions are used to model the unconditional distribution of financial asset returns, as both models display heavy tails. The relevance of the two models is subject to debate because empirical estimates of the tail shape conditional on either model give conflicting signals. This stems from opposing bias terms. We exploit the biases to discriminate between the two distributions. A sign estimator for the second‐order scale parameter strengthens our results. Tail estimates based on asset return data match the bias induced by finite‐variance unconditional Student t data and the generalized autoregressive conditional heteroscedasticity process.
Effect of silicon‐doped calcium phosphate bone grafting materials on bone regeneration and osteogenic marker expression after implantation in the ovine scapula
Authors: Knabe Christine , Adel‐Khattab Doaa , Hübner Wolf‐Dietrich , Peters Fabian , Knauf Tom , Peleska Barbara , Barnewitz Dirk , Genzel Antje , Kusserow Roderik , Sterzik Florian , Stiller Michael , Müller‐Mai Christian 
Published: May 2018

AbstractCompared to the currently clinically available bone grafting materials for alveolar ridge augmentation, there is a great demand for bioactive bone substitutes with higher resorbability, which enhance osteogenesis at the same time. This has prompted the development of a silicon‐doped rapidly resorbable calcium alkali orthophosphate (Si‐CAOP) and silicon‐doped β‐tricalcium phosphate (Si‐TCP). This study evaluated the effect of these two particulate graft materials as compared to the currently clinically used β‐TCP on bone formation and osteogenic marker expression after 2 weeks, 1, 3, 6, 12, and 18 months of implantation in critical size defects in the sheep scapula. Immunohistochemical analysis of collagen type I, alkaline phosphatase, and osteocalcin expression was performed on resin embedded sections. The bone and particle area fraction and the bone‐biomaterial contact were determined histomorphometrically. After 2 weeks and 1 month defects grafted with Si‐CAOP displayed a significantly greater bone area fraction, bone‐particle‐contact, osteogenic marker expression and significantly lower particle area fraction than defects grafted with Si‐TCP and TCP. By 3 and 6 months all materials studied mediated excellent defect regeneration with further bone remodeling at 12 and 18 months. Taken together, Si‐CAOP induced the most expeditious bone regeneration of critical size defects in the sheep scapula. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2018. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 594–614, 2019.
Highly efficient hemicellulose utilization for acetoin production by an engineered Bacillus subtilis
Authors: Li Xinli , Huang Can , Yu Xinlei , Liu Shuang , Wang Zhiwen , Tang Ya‐Jie , Chen Tao 
Published: May 2018

AbstractBACKGROUNDHemicellulose is considered one of the most abundant renewable bio‐resources and has been utilized as substrate for the manufacture of numerous bio‐products through microbiological approaches. However, it has rarely been reported that acetoin was produced directly from hemicellulose by microbial fermentation via consolidated bioprocessing (CBP).RESULTSTo achieve efficient xylan utilization, four endo‐1,4‐beta‐xylanase and three β‐xylosidase were co‐overexpressed in Bacillus subtilis. Among the resulting engineered strains, BSL24, harboring xyn10B (from Clostridium stercorarium) and xsa (from Selenomonas ruminantium GA192) expression plasmid pHP13‐E2X4 exhibited the best fermentation performance in xylan degradation with relatively high endo‐1,4‐beta‐xylanase and β‐xylosidase activities, reaching 937.5 and 68 U L−1, respectively. The activities of the two enzymes were further improved by 83.0% and 124.6%, respectively, by using yeast extract as nitrogen source. Moreover, the addition of 0.25% v/w D‐valine can further stimulate the total activity of endo‐1,4‐beta‐xylanase in the cultures. Finally, pHP13‐E2X4 was introduced in an acetoin‐producing strain (168ARSRCPΔacoAΔbdhA), and the resulting strain BSL24AC produced 6.9 g L−1 acetoin from 1 g L−1 xylose and 19 g L−1 xylan in 96 h, with a yield of 0.345 g g−1, corresponding to 72.6% of the theoretical yield. When the xylan concentration was increased to 49 g L−1, BSL24AC produced 15 g L−1 acetoin in 132 h, corresponding to an acetoin yield of 0.300 g g−1 total sugar.CONCLUSIONSBacillus subtilis was engineered to directly utilize hemicellulose by co‐overexpression of different xylan hydrolases. To the best of our knowledge, this is the first study on efficient production of acetoin from hemicellulose via CBP in Bacillus subtilis. © 2018 Society of Chemical Industry
Surfactant effects on wettability of Penicillium frequentans formulations to improve brown rot biocontrol
Authors: Guijarro Belén , Larena Inmaculada , Melgarejo Paloma , De Cal Antonieta 
Published: May 2018

ABSTRACTBACKGROUNDPenicillium frequentans can be used in the management of brown rot caused by Monilinia spp. Competition is the primary mode of biocontrol activity of P. frequentans, which must therefore cover most of fruit surface to avoid pathogen infection. Our objective was to optimize the efficacy of P. frequentans by maximizing fruit surface coverage and retention with the antagonist formulation by surfactant incorporation.RESULTSSixteen surfactants were assessed for the management of brown rot at 3–5 different concentrations. Nine surfactants increased the droplet surface up to 2.5 times compared with water on an inert surface, with or without the presence of P. frequentans in each drop. Eight surfactants increased P. frequentans on the fruit surface, enhancing colony forming units after run off or lateral spray application uptake by 50% compared to the control without surfactants. But only some doses of sodium carboxymethyl cellulose, gelatin, Tween 20, sorbitan alkyl esters, synthetic latex, polyethylene glycol isotridecyl ether, and hydroxypropyl methylcellulose could show the same covered fruit surface after run off or lateral spray application. There were also no phytotoxic side‐effects on five different species of stone fruit.CONCLUSIONSThe efficacy of P. frequentans dry conidia can be enhanced by optimizing the composition of the formulation with surfactants. © 2018 Society of Chemical Industry
3D‐specific absorption rate estimation from high‐intensity focused ultrasound sonications using the Green's function heat kernel
Authors: Freeman Nicholas J. , Odéen Henrik , Parker Dennis L. 
Published: May 2018

PurposeTo evaluate a numerical inverse Green's function method for deriving specific absorption rates (SARs) from high‐intensity focused ultrasound (HIFU) sonications using tissue parameters (thermal conductivity, specific heat capacity, and mass density) and three‐dimensional (3D) magnetic resonance imaging (MRI) temperature measurements.MethodsSAR estimates were evaluated using simulations and MR temperature measurements from HIFU sonications. For simulations, a “true” SAR was calculated using the hybrid angular spectrum method for ultrasound simulations. This “true” SAR was plugged into a Pennes bioheat transfer equation (PBTE) solver to provide simulated temperature maps, which were then used to calculate the SAR estimate using the presented method. Zero mean Gaussian noise, corresponding to temperature precisions between 0.1 and 2.0°C, was added to the temperature maps to simulate a variety of in vivo situations. Experimental MR temperature maps from HIFU sonications in a gelatin phantom monitored with a 3D segmented echo planar imaging MRI pulse sequence were also used. To determine the accuracy of the simulated and phantom data, we reconstructed temperature maps by plugging in the estimated SAR to the PBTE solver. In both simulations and phantom experiments, the presented method was compared to two previously published methods of determining SAR, a linear and an analytical method. The presented numerical method utilized the full 3D data simultaneously, while the two previously published methods work on a slice‐by‐slice basis.ResultsIn the absence of noise, SAR distribution estimates obtained from the simulated heating profiles match closely (within 10%) to the initial true SAR distribution. The resulting temperature distributions also match closely to the corresponding initial temperature distributions (<0.2°C RMSE). In the presence of temperature measurement noise, the SAR distributions have noise amplified by the inverse convolution process, while the resulting temperature distributions still match closely to the initial “true” temperature distributions. In general, temperature RMSE was observed to be approximately 20–30% higher than the level of the added noise. By contrast, the previously published linear method is less sensitive to noise, but significantly underpredicts the SAR. The analytic method is also less sensitive to noise and matches SAR in the central plane, but greatly underpredicts in the longitudinal direction. Similar observations are made from the phantom studies. The described numerical inverse Green's function method is very fast — at least two orders of magnitude faster than the compared methods.ConclusionThe presented numerical inverse Green's function method is computationally fast and generates temperature maps with high accuracy. This is true despite generally overestimating the true SAR and amplifying the input noise.
Technical Note: Interleaved bipolar acquisition and low‐rank reconstruction for water–fat separation in MRI
Authors: Cho JaeJin , Park HyunWook 
Published: May 2018

PurposeTo acquire interleaved bipolar data and reconstruct the full data using low‐rank property for water–fat separation.MethodsBipolar acquisition suffers from issues related to gradient switching, the opposite gradient polarities, and other system imperfections, which prevent accurate water–fat separation. In this study, an interleaved bipolar acquisition scheme and a low‐rank reconstruction method were proposed to reduce issues from the bipolar gradients while achieving a short imaging time. The proposed interleaved bipolar acquisition scheme collects echo‐time signals from both gradient polarities; however, the sequence increases the imaging time. To reduce the imaging time, the signals were subsampled at every dimension of k‐space. The low‐rank property of the bipolar acquisition was defined and exploited to estimate the full data from the acquired subsampled data. To eliminate the bipolar issues, in the proposed method, the water–fat separation was performed separately for each gradient polarity, and the results for the positive and negative gradient polarities were combined after the water–fat separation.ResultsA phantom study and in vivo experiments were conducted on a 3T Siemens Verio system. The results for the proposed method were compared with the results of the fully sampled interleaved bipolar acquisition and the Soliman's method, which was the previous water–fat separation approach for reducing the issues of bipolar gradients and accelerating the interleaved bipolar acquisition. The proposed method provided accurate water and fat images without the issues of bipolar gradients and demonstrated a better performance compared with the results of the previous methods.ConclusionsThe water–fat separation using the bipolar acquisition has several benefits including a short echo‐spacing time. However, it suffers from bipolar‐gradient issues such as strong gradient switching, system imperfection, and eddy current effects. This study demonstrated that accurate water–fat separated images can be obtained using the proposed interleaved bipolar acquisition and low‐rank reconstruction by using the benefits of the bipolar acquisition while reducing the bipolar‐gradient issues with a short imaging time.
Impact of interpatient variability on organ dose estimates according to MIRD schema: Uncertainty and variance‐based sensitivity analysis
Authors: Zvereva Alexandra , Kamp Florian , Schlattl Helmut , Zankl Maria , Parodi Katia 
Published: May 2018

PurposeVariance‐based sensitivity analysis (SA) is described and applied to the radiation dosimetry model proposed by the Committee on Medical Internal Radiation Dose (MIRD) for the organ‐level absorbed dose calculations in nuclear medicine. The uncertainties in the dose coefficients thus calculated are also evaluated.MethodsA Monte Carlo approach was used to compute first‐order and total‐effect SA indices, which rank the input factors according to their influence on the uncertainty in the output organ doses. These methods were applied to the radiopharmaceutical (S)‐4‐(3‐18F‐fluoropropyl)‐L‐glutamic acid (18F‐FSPG) as an example. Since 18F‐FSPG has 11 notable source regions, a 22‐dimensional model was considered here, where 11 input factors are the time‐integrated activity coefficients (TIACs) in the source regions and 11 input factors correspond to the sets of the specific absorbed fractions (SAFs) employed in the dose calculation. The SA was restricted to the foregoing 22 input factors. The distributions of the input factors were built based on TIACs of five individuals to whom the radiopharmaceutical 18F‐FSPG was administered and six anatomical models, representing two reference, two overweight, and two slim individuals. The self‐absorption SAFs were mass‐scaled to correspond to the reference organ masses.ResultsThe estimated relative uncertainties were in the range 10%–30%, with a minimum and a maximum for absorbed dose coefficients for urinary bladder wall and heart wall, respectively. The applied global variance‐based SA enabled us to identify the input factors that have the highest influence on the uncertainty in the organ doses. With the applied mass‐scaling of the self‐absorption SAFs, these factors included the TIACs for absorbed dose coefficients in the source regions and the SAFs from blood as source region for absorbed dose coefficients in highly vascularized target regions. For some combinations of proximal target and source regions, the corresponding cross‐fire SAFs were found to have an impact.ConclusionGlobal variance‐based SA has been for the first time applied to the MIRD schema for internal dose calculation. Our findings suggest that uncertainties in computed organ doses can be substantially reduced by performing an accurate determination of TIACs in the source regions, accompanied by the estimation of individual source region masses along with the usage of an appropriate blood distribution in a patient's body and, in a few cases, the cross‐fire SAFs from proximal source regions.
Prostate DCE‐MRI with correction using an approximated analytical approach
Authors: Zhong Xinran , Martin Thomas , Wu Holden H. , Nayak Krishna S. , Sung Kyunghyun 
Published: May 2018

PurposeTo develop and evaluate a practical

correction method for prostate dynamic contrast‐enhanced (DCE) MRI analysis.TheoryWe proposed a simple analytical

correction method using a Taylor series approximation to the steady‐state spoiled gradient echo signal equation. This approach only requires

maps and uncorrected pharmacokinetic (PK) parameters as input to estimate the corrected PK parameters.MethodsThe proposed method was evaluated using a prostate digital reference object (DRO), and 82 in vivo prostate DCE‐MRI cases. The approximated analytical correction was compared with the ground truth PK parameters in simulation, and compared with the reference numerical correction in in vivo experiments, using percentage error as the metric.ResultsThe prostate DRO results showed that our approximated analytical approach provided residual error less than 0.4% for both Ktrans and ve, compared to the ground truth. This noise‐free residual error was smaller than the noise‐induced error using the reference numerical correction, which had a minimum error of 2.1+4.3% with baseline signal‐to‐noise ratio of 234.5. For the 82 in vivo cases, Ktrans and ve percentage error compared to the reference numerical correction method had a mean of 0.1% (95% central range of [0.0%, 0.2%]) across the prostate volume.ConclusionThe approximated analytical

correction method provides comparable results with less than 0.2% error within 95% central range, compared to reference numerical

correction. The proposed method is a practical solution for

correction in prostate DCE‐MRI because of its simple implementation.
Reliability of the Animated Activity Questionnaire for assessing activity limitations of patients with hip and knee osteoarthritis
Authors: Peter W.F. , de Vet H.C.W. , Terwee C.B. 
Published: May 2018

AbstractObjectiveThe aim of the study was to determine the internal consistency, test–retest reliability and measurement error of the Animated Activity Questionnaire (AAQ) for assessing activity limitations in hip and knee osteoarthritis (HKOA) patients.MethodsA total of 1,177 patients, from six countries (the Netherlands, UK, France, Denmark, Italy and Spain), completed the AAQ, a questionnaire consisting of videos displaying 17 activities with 3–5 levels of performance, from which patients choose the video that best matches their own performance. Unidimensionality was assessed by means of confirmatory factor analysis (CFA), using the following fit indices: the Tucker–Lewis index (TFI) >0.95, comparative fit index (CFI) >0.95, and root mean square error of approximation (RMSEA) <0.06. Cronbach's alpha was computed. In 238 patients who completed the AAQ twice, the intra‐class correlation coefficient (ICC) was calculated for test–retest reliability. The standard error of measurement (SEM) and the smallest detectable change (SDC) were calculated as parameters of measurement error.ResultsThe fit indices for unidimensionality were CFI 0.957, TLI 0.950, and RMSEA 0.144. Cronbach's alpha was 0.95. ICC for test–retest reliability was 0.93 (95% confidence interval 0.91 to 0.95), ranging from 0.85 to 0.98 across countries. SEM and SDC were 4.9 and 13.6, respectively, on a scale from 0 to 100, and ranging from 2.7 to 6.7, and from 7.5 to 18.4, respectively, across countries. The AAQ appeared to measure slightly more precisely in patients with knee problems and patients without prosthesis.ConclusionThe AAQ seemed to be unidimensional, and showed good internal consistency and test–retest reliability. The SDC indicated that changes in scores of at least 14% indicate real improvement in activity limitations.
The associations between anthropometric measurements and left ventricular structure and function: the Echo‐SOL Study
Authors: Ponce S. , Allison M. A. , Swett K. , Cai J. , Desai A. A. , Hurwitz B. E. , Ni A. , Schneiderman N. , Shah S. J. , Spevack D. M. , Talavera G. A. , Rodriguez C. J. 
Published: May 2018

SummaryObjectiveThe objective of this study is to determine associations between anthropometry and echocardiographic measures of cardiac structure and function in Hispanic/Latinos.MethodsA total of 1,824 participants from ECHO‐SOL were included. We evaluated associations between echocardiographic measures of left ventricular structure and function and anthropometric measures using multivariable‐adjusted linear and logistic regression models adjusting for traditional cardiovascular risk factors.ResultsThe mean age was 56 ± 0.17 years, 57% were women. The mean body mass index (BMI) was 30 ± 9.4 kg m−2, waist circumference (WC) was 100 ± 18 cm, and waist‐to‐hip ratio (WHR) was 0.93 ± 0.15. Adjusted analysis showed that 5‐unit increment in BMI and 5‐cm increase in WC was associated with 3.4 ± 0.6 and 1.05 ± 0.05 g m−2.7 (p < 0.05 for both) higher left ventricular (LV) mass index, respectively. Similarly, 0.1‐unit increment in WHR was associated with 2.0 ± 0.16 g m−2.7 higher LV mass index (p < 0.01). WHR was associated with 0.22 ± 0.08% decrease in ejection fraction (p < 0.05). Concomitantly, 5‐unit increment in BMI and WC was associated with increased odds of abnormal LV geometry (odds ratio 1.40 and 1.16, p = 0.03 and <0.01, respectively); 0.1‐unit increment in WHR was associated with increased odds of abnormal LV geometry (odds ratio 1.51, p < 0.01).ConclusionsAmong Hispanic/Latinos, higher anthropometric measures were associated with adverse cardiac structure and function.
Ventilator Bundle Compliance and Risk of Ventilator-Associated Events
Authors: Harris Bryan D. , Thomas Gale A. , Greene Matthew H. , Spires Steven S. , Talbot Thomas R. 
Published: May 2018

OBJECTIVEVentilator bundles encompass practices that reduce the risk of ventilator complications, including ventilator-associated pneumonia. The impact of ventilator bundles on the risk of developing ventilator-associated events (VAEs) is unknown. We sought to determine whether decreased compliance to the ventilator bundle increases the risk for VAE development.DESIGNNested case-control study.SETTINGThis study was conducted at 6 adult intensive care units at an academic tertiary-care center in Tennessee.PATIENTSIn total, 273 patients with VAEs were randomly matched in a 1:4 ratio to controls by mechanical ventilation duration and ICU type.METHODSControls were selected from the primary study population at risk for a VAE after being mechanically ventilated for the same number of days as a specified case. Using conditional logistic regression analysis, overall cumulative compliance, and compliance with individual components of the bundle in the 3 and 7 days prior to VAE development (or the control match day) were examined.RESULTSOverall bundle compliance at 3 days (odds ratio [OR], 1.15; P=.34) and 7 days prior to VAE diagnosis (OR, 0.96; P=.83) were not associated with VAE development. This finding did not change when limiting the outcome to infection-related ventilator-associated complications (IVACs) and after adjusting for age and gender. In the examination of compliance with specific bundle components increased compliance with chlorhexidine oral care was associated with increased risk of VAE development in all analyses.CONCLUSIONSVentilator bundle compliance was not associated with a reduced risk for VAEs. Higher compliance with chlorhexidine oral care was associated with a greater risk for VAE development.Infect Control Hosp Epidemiol 2018;39:637–643
Moral externalization is an implausible mechanism for cooperation, let alone “hypercooperation”
Authors: Johnson Tim 
Published: May 2018

AbstractTo facilitate cooperation, moral externalization requires truthful and meticulous information about others’ moral commitments (Stanford target article, sect. 6). By definition, this information does not exist in the low-information environments where humans display their “hypercooperativeness.” Furthermore, collecting that information – if possible – entails costs that other mechanisms for correlated interaction avoid. Hence, moral externalization is an unlikely mechanism for cooperation, let alone “hypercooperation.”
Do the folk need a meta-ethics?
Authors: Patel Shivam , Machery Edouard 
Published: May 2018

AbstractStanford argues that cooperators achieve and maintain correlated interaction through the objectification of moral norms. We first challenge the moral/non-moral distinction that frames Stanford's discussion. We then argue that to the extent that norms are objectified (and we hold that they are at most objectified in a very thin sense), it is not for the sake of achieving correlated interaction.
Do we really externalize or objectivize moral demands?
Authors: Stich Stephen 
Published: May 2018

AbstractStanford's goal is to explain the uniquely human tendency to externalize or objectify “distinctively moral” demands, norms, and obligations. I maintain that there is no clear phenomenon to explain. Stanford's account of which norms are distinctively moral relies on Turiel's problematic work. Stanford's justification of the claim that we “objectify” moral demands ignores recent studies indicating that often we do not.