bluuebunny/crossref_metadata_2025_split huggingface dataset:
Defining ecosystem thresholds for human activities and environmental pressures in the California Current
Authors: Samhouri Jameal F. , Andrews Kelly S. , Fay Gavin , Harvey Chris J. , Hazen Elliott L. , Hennessey Shannon M. , Holsman Kirstin , Hunsicker Mary E. , Large Scott I. , Marshall Kristin N. , Stier Adrian C. , Tam Jamie C. , Zador Stephani G. 
Published: June 2017

AbstractThe oceans are changing more rapidly than ever before. Unprecedented climatic variability is interacting with unmistakable long‐term trends, all against a backdrop of intensifying human activities. What remains unclear, however, is how to evaluate whether conditions have changed sufficiently to provoke major responses of species, habitats, and communities. We developed a framework based on multimodel inference to define ecosystem‐based thresholds for human and environmental pressures in the California Current marine ecosystem. To demonstrate how to apply the framework, we explored two decades of data using gradient forest and generalized additive model analyses, screening for nonlinearities and potential threshold responses of ecosystem states (n = 9) across environmental (n = 6) and human (n = 10) pressures. These analyses identified the existence of threshold responses of five ecosystem states to four environmental and two human pressures. Both methods agreed on threshold relationships in two cases: (1) the winter copepod anomaly and habitat modification, and (2) sea lion pup production and the summer mode of the Pacific Decadal Oscillation (PDO). Considered collectively, however, these alternative analytical approaches imply that as many as five of the nine ecosystem states may exhibit threshold changes in response to negative PDO values in the summer (copepods, scavengers, groundfish, and marine mammals). This result is consistent with the idea that the influence of the PDO extends across multiple trophic levels, but extends current knowledge by defining the nonlinear nature of these responses. This research provides a new way to interpret changes in the intensities of human and environmental pressures as they relate to the ecological integrity of the California Current ecosystem. These insights can be used to make more informed assessments of when and under what conditions intervention, preparation, and mitigation may enhance progress toward ecosystem‐based management goals.
Wall modeling via function enrichment within a high‐order DG method for RANS simulations of incompressible flow
Authors: Krank Benjamin , Kronbichler Martin , Wall Wolfgang A. 
Published: June 2017

SummaryWe present a novel approach to wall modeling for the Reynolds‐averaged Navier‐Stokes equations within the discontinuous Galerkin method. Wall functions are not used to prescribe boundary conditions as usual, but they are built into the function space of the numerical method as a local enrichment, in addition to the standard polynomial component. The Galerkin method then automatically finds the optimal solution among all shape functions available. This idea is fully consistent and gives the wall model vast flexibility in separated boundary layers or high adverse pressure gradients. The wall model is implemented in a high‐order discontinuous Galerkin solver for incompressible flow complemented by the Spalart‐Allmaras closure model. As benchmark examples, we present turbulent channel flow starting from Reτ=180 and up to Reτ=100000 as well as flow past periodic hills at Reynolds numbers based on the hill height of ReH=10595 and ReH=19000.
Therapeutic D2/3 receptor occupancies and response with low amisulpride blood concentrations in very late‐onset schizophrenia‐like psychosis (VLOSLP)
Authors: Reeves Suzanne , Eggleston Kate , Cort Elizabeth , McLachlan Emma , Brownings Stuart , Nair Akshay , Greaves Suki , Smith Alan , Dunn Joel , Marsden Paul , Kessler Robert , Taylor David , Bertrand Julie , Howard Robert 
Published: June 2017

ObjectiveAntipsychotic drug sensitivity in very late‐onset schizophrenia‐like psychosis (VLOSLP) is well documented, but poorly understood. This study aimed to investigate blood drug concentration, D2/3 receptor occupancy and outcome in VLOSLP during open amisulpride prescribing, and compare this with Alzheimer's disease (AD).MethodsBlood drug concentration, prolactin, symptoms and extrapyramidal side‐effects (EPS) were serially assessed during dose titration. [18F]fallypride imaging was used to quantify D2/3 receptor occupancy. Average steady‐state amisulpride concentration (Caverage, ng/ml) was estimated by incorporating pharmacokinetic (PK) data into an existing population PK model (25 AD participants, 20 healthy older people).ResultsEight patients (target 20) were recruited (six women; 76 + − 6 years; six treatment compliant; five serially sampled; three with paired imaging data). Mean + − SD symptom reduction was 74 ± 12% (50–100 mg/day; 92.5 + −39.4 ng/ml). Mild EPS emerged at 96 ng/ml (in AD, severe EPS, 50 mg/day, 60 ng/ml). In three participants, imaged during optimal treatment (50 mg/day; 41–70 ng/ml), caudate occupancy was 44–59% (58–74% in AD across a comparable Caverage).ConclusionsDespite the small sample size, our findings are highly relevant as they suggest that, as in AD, 50 mg/day amisulpride is associated with >40% occupancy and clinically relevant responses in VLOSLP. It was not possible to fully characterise concentration–occupancy relationships in VLOSLP, and it is thus unclear whether the greater susceptibility of those with AD to emergent EPS was accounted for by increased central drug access. Further investigation of age‐ and diagnosis‐specific threshold sensitivities is warranted, to guide amisulpride prescribing in older people, and therapeutic drug monitoring studies offer a potentially informative future approach. Copyright © 2017 John Wiley & Sons, Ltd.
Development of thumb endurance curves associated with various exertion levels
Authors: Choi Kyeong‐Hee , Lee Sung‐Yong , Lee Jun‐Hyub , Kong Yong‐Ku 
Published: June 2017

AbstractTasks involving the thumbs of workers are frequently carried out at industrial sites or in laboratories. This study measured thumb endurance time according to relative force levels in males and females. The experiment in this study involved 30 healthy participants (15 males and 15 females). Maximum thumb pressing force (MTPF) was measured and thumb endurance curves were developed using the measured thumb endurance time of participants’ dominant hand according to various force levels (10, 20, 40, 60, 80, and 100% MTPF). On the basis of the results, females demonstrated greater endurance time than males at 20% MTPF, and statistically significant differences according to gender are not shown at MTPF levels of 40% or higher. A rapid increase in endurance time was observed at low force levels. The findings of this study are expected to facilitate the establishment of appropriate working levels for the thumbs of workers in order to optimize work design. In this study, the effects of gender and target force level on thumb endurance time performance were evaluated. The findings of this study could provide valuable information for developing ergonomic guidelines of thumb pressing force tasks for the workers.
The effect of collagen coating on titanium with nanotopography on in vitro osteogenesis
Authors: Costa Daniel G. , Ferraz Emanuela P. , Abuna Rodrigo P. F. , de Oliveira Paulo T. , Morra Marco , Beloti Marcio M. , Rosa Adalberto L. 
Published: June 2017

AbstractSeveral studies have shown the positive effects of Ti either with nanotopography or coated with collagen on osteoblast differentiation. Thus, we hypothesized that the association of nanotopography with collagen may increase the in vitro osteogenesis on Ti surface. Ti discs with nanotopography with or without collagen coating were characterized by scanning electron microscopy and atomic force microscopy. Rat calvaria‐derived osteoblastic cells were cultured on both Ti surfaces for up to 14 days and the following parameters were evaluated: cell proliferation, alkaline phosphatase (ALP) activity, extracellular matrix mineralization, protein expression of bone sialoprotein (BSP) and osteopontin (OPN), and gene expression of collagen type 1a (Coll1a), runt‐related transcription factor 2 (Runx2), osterix (OSX), osteocalcin (OC), Ki67, Survivin, and Bcl2‐associated X protein (BAX). Surface characterization evidenced that collagen coating did not alter the nanotopography. Collagen coating increased cell proliferation, ALP activity, extracellular matrix mineralization, and Coll1a, OSX, OC, and BAX gene expression. Also, OPN and BSP proteins were strongly detected in cultures grown on both Ti surfaces. In conclusion, our results showed that the combination of nanotopography with collagen coating stimulates the early, intermediate, and final events of the in vitro osteogenesis and may be considered a potential approach to promote osseointegration of Ti implants. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2783–2788, 2017.
Hemostatic efficiency of modern topical sealants: Comparative evaluation after liver resection and splenic laceration in a swine model
Authors: Fonouni Hamidreza , Kashfi Arash , Majlesara Ali , Stahlheber Oliver , Konstantinidis Lukas , Gharabaghi Negin , Kraus Thomas W. , Mehrabi Arianeb , Oweira Hani 
Published: June 2017

AbstractParenchymal transection during hepatobiliary surgery can disrupt small vasculature or bile ducts, which could be managed difficultly. Sealants are helpful tools to achieve better hemostasis. The aim of this study is to analyze the hemostatic efficiency of four modern sealants in a porcine model. In this study, 40 landrace pigs were assigned equally to the control (without sealant) and four sealant groups. Standardized liver resection and splenic lesions were performed and left without using sealant (control) or treated with one of the following sealants: TachoSil®, Tissucol Duo®, Coseal®, and FloSeal®. We measured relative and absolute bleeding times (seconds) as well as total blood loss (g) in a maximum observation time of 300 s. Sealants could show a significantly improved hemostasis comparing to the control group. However, hemostasis was heterogeneous among the sealant groups (liver resection: 60%–100%, spleen injury: 70%–100%). The mean blood loss decreased significantly using sealants comparing to control group (liver resection: 6–120 fold, spleen injury: 2.5–36 fold). The hemostatic time in groups that achieved complete hemostasis was different in each sealant group (liver resection: 30–166 s, spleen injury: 60–180 s). We conclude that the hemostatic efficacy of modern sealants is impressive but heterogeneous in liver resection or splenic lesion. To maximize the effectiveness of these tools, the indication of each sealant should be carefully considered in individual settings by the surgeons. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1307–1316, 2018.
Ethnography, Applied Theatre and Stiwanism: Creative Methods in Search of Praxis Amongst Men and Women in Jinja, Uganda
Authors: McQuaid Katie , Plastow Jane 
Published: June 2017

AbstractThis article critically reflects on a long‐term intergenerational project combining ethnographic and social science research methods and Freirean‐inspired applied theatre in a long‐term participatory process working alongside men and women in search of a ‘plenitude of praxis’: strengthening and promoting an urban community's capacity to unite across social barriers in recognising systemic injustices and inequalities and challenging these through community‐led interventions in pursuit of common social justice outcomes. It reflects on the successes, complexities and failures of an approach rooted in African feminism, and in particular stiwanism, in a context of entrenched urban poverty in Jinja Municipality, Uganda. Copyright © 2017 John Wiley & Sons, Ltd.
Influence of Thermo‐Oxidative Ageing of HNBR in Oil Field Applications
Authors: Balasooriya Winoj , Schrittesser Bernd , Karunakaran Santhosh , Schlögl Sandra , Pinter Gerald , Schwarz Thomas , Kadar Zalan 
Published: June 2017

SummaryThe oxidative ageing behavior of carbon black‐ (85 phr) filled hydrogenated nitrile‐butadiene rubber (HNBR) was characterized in this study. HNBR is widely used in many oil and gas field applications for seals, hoses, down‐hole packers etc., due to its intrinsic combination of good heat and excellent oil and chemical resistance, coupled with outstanding physical properties. Hence, to support the material development, it is of prime theoretical and practical importance to characterize the ageing behavior of HNBR. In this work, mechanical properties and dynamic mechanical properties of aged and un‐aged material were examined using tensile, tear and dynamic mechanical analysis tests. Possible micro structural changes and functional groups involved in aging were detected using DQ NMR, Raman spectroscopy and FT‐IR spectroscopy in ATR mode. The results indicated that the ageing process caused the material to deteriorate; tensile strength − strain at break, the strain at tear strength and the damping properties were decreased. Additionally, the stiffness and the glass transition temperature of the material were also raised. According to the literature, residual double bonds in HNBR are involved in forming hydro peroxide and propagating the autocatalytic oxidation process in the presence of oxygen at higher temperature. This process leads to the oxidative degradation resulting in cross‐linking and in chain scissions as the predominant reactions contributing to properties. Furthermore, at ∼100 °C, oxidation through the nitrile group was observed converting the cyano functional group into the imino group; but at higher temperatures, it was negligible. The results suggest that the cross‐linking and the chain scission mechanisms are significant after 72 hours and 168 hours of exposure, respectively, at 150 °C. However, when aged at 170 °C, both cross‐linking and chain scission were even effective after 24 hours of exposure time.
Mixed Mode Fracture Mechanics Behaviour of PMMA
Authors: Lach Ralf , Grellmann Wolfgang 
Published: June 2017

SummaryThe mixed mode brittle fracture (mode I/mode II) of poly(methyl methacrylate) (PMMA) was investigated using single‐edge notched tensile (SENT) specimens by applying a mixed mode special loading device which allows varying the loading angle from 0° (pure mode I) to 90° (pure mode II). The experimental results dealing with mixed mode fracture toughness and initial angle of crack propagation are in good agreement with predictions based on a modified criterion of maximum tangential stress (MTS criterion) where non‐singular stresses (T stresses) are considered. These additional T stresses are the reason why distinct fracture by normal stress with crazing is always macroscopically observed in PMMA under the selected loading conditions including pure external mode II loading. Therefore, the length of the craze zone, i.e. the process zone, has been determined to be about 0.5 mm independent of the loading angle. It has to be pointed out that the fracture surface morphology should be kept in mind more often in future for assessing the mixed mode fracture mechanics parameters.
Simultaneous mapping of metabolites and individual macromolecular components via ultra‐short acquisition delay 1H MRSI in the brain at 7T
Authors: Považan Michal , Strasser Bernhard , Hangel Gilbert , Heckova Eva , Gruber Stephan , Trattnig Siegfried , Bogner Wolfgang 
Published: June 2017

PurposeShort‐echo‐time proton MR spectra at 7T feature nine to 10 distinct macromolecule (MM) resonances that overlap with the signals of metabolites. Typically, a metabolite‐nulled in vivo MM spectrum is included in the quantification`s prior knowledge to provide unbiased metabolite quantification. However, this MM model may fail if MMs are pathologically altered. In addition, information about the individual MM peaks is lost. In this study, we aimed to create an improved MM model by parameterization of the in vivo MM spectrum into individual components, and to use this new model to quantify free induction decay MR spectroscopic imaging (FID‐MRSI) data.MethodsThe measured in vivo MM spectrum was parameterized using advanced method for accurate, robust, and efficient spectral fitting (AMARES) and Hankel‐Lanczos singular value decomposition algorithms from which six different MM models were derived. Soft constraints were applied to avoid over‐parameterization. All MM models were combined with simulated metabolite spectra to form complete basis sets. FID‐MRSI data from 14 healthy volunteers were quantified via LCModel, and the results were compared between all basis sets.ResultsThe MM model using nine individual AMARES‐parameterized MM components with additional soft constraints achieved the most reliable results. Nine MMs and seven metabolites were mapped simultaneously over the whole slice.ConclusionThe proposed MM model may facilitate studies that involve patients with pathologically altered MMs. Magn Reson Med 79:1231–1240, 2018. © 2017 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Non‐Gaussian diffusion imaging with a fractional order calculus model to predict response of gastrointestinal stromal tumor to second‐line sunitinib therapy
Authors: Tang Lei , Sui Yi , Zhong Zheng , Damen Frederick C. , Li Jian , Shen Lin , Sun Yingshi , Zhou Xiaohong Joe 
Published: June 2017

PurposeTo demonstrate the clinical value of a non‐Gaussian diffusion model using fractional order calculus (FROC) for early prediction of the response of gastrointestinal stromal tumor to second‐line sunitinib targeted therapy.MethodsFifteen patients underwent sunitinib treatment after imatinib resistance. Diffusion‐weighted imaging with multiple b‐values was performed before treatment (baseline) and 2 weeks (for early prediction of response) after initiating sunitinib treatment. Conventional MRI images at 12 weeks were used to determine the good and poor responders according to the modified Choi criteria for MRI. Diffusion coefficient D, fractional order parameter β (which correlates to intravoxel tissue heterogeneity), and a microstructural quantity µ were calculated using the FROC model. The FROC parameters and the longest diameter of the lesion, as well as their changes after 2 weeks of treatment, were compared between the good and poor responders. Additionally, the pretreatment FROC parameters were individually combined with the change in D (ΔD) using a logistic regression model to evaluate response to sunitinib treatment with a receiver operating characteristic analysis.ResultsForty‐two good‐responding and 32 poor‐responding lesions were identified. Significant differences were detected in pretreatment β (0.67 versus 0.74, P = 0.011) and ΔD (45.7% versus 12.4%, P = 0.001) between the two groups. The receiver operating characteristic analysis showed that ΔD had a significantly higher predictive power than the tumor size change (area under the curve: 0.725 versus 0.580; 0.95 confidence interval). When ΔD was combined with pretreatment β, the area under the curve improved to 0.843 with a predictive accuracy of 75.7% (56 of 74).ConclusionsThe non‐Gaussian FROC diffusion model showed clinical value in early prediction of gastrointestinal stromal tumor response to second‐line sunitinib targeted therapy. The pretreatment FROC parameter β can increase the predictive accuracy when combined with the change in diffusion coefficient during treatment. Magn Reson Med 79:1399–1406, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
Off‐resonance based assessment of metallic wear debris near total hip arthroplasty
Authors: Koch Kevin M. , Koff Matthew F. , Bauer Thomas W. , Shah Parina H. , Nencka Andrew S. , Sivaram Kaushik S. , Potter Hollis G. 
Published: June 2017

PurposeThe presence of metallic debris near total hip arthroplasty can have a significant impact on longitudinal patient management. Methods for magnetic resonance imaging‐based quantification of metallic debris near painful total hip replacements are described and applied to cohorts of symptomatic and control subject cases.MethodsA combination of metal artifact reduction, off‐resonance mapping, off‐resonance background removal, and spatial clustering methods are utilized to quantify off‐resonance signatures in cases of suspected metallosis. These methods are applied to a cohort of symptomatic hip arthroplasties composed of cobalt‐chromium alloys. Magnetostatic simulations and theoretical principles are used to illuminate the potential sources of the measured off‐resonance effects. Reported metrics from histological tissue assays extracted during surgical revision procedures are also correlated with the proposed magnetic resonance imaging‐based quantification results.ResultsThe presented methods identified quantifiable metallosis signatures in more than 70% of the symptomatic and none of the control cases. Preliminary correlations of the MR data with direct histological evaluation of retrieved tissue samples indicate that the observed off‐resonance effect may be related to tissue necrosis.ConclusionsMagnetostatic simulations, theoretical principles, and preliminary histological trends suggest that disassociated cobalt is the source of the observed off‐resonance signature. Magn Reson Med 79:1628–1637, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
Modelling large plastic deformations of cohesive soils using sequential limit analysis
Authors: Kong D. , Martin C. M. , Byrne B. W. 
Published: June 2017

SummaryThis paper introduces sequential limit analysis (SLA) as a method for modelling large plastic deformations of purely cohesive materials such as undrained clay. The method involves solving a series of consecutive small‐deformation plastic collapse problems using finite element limit analysis, thus ensuring high levels of accuracy, efficiency, and robustness. The techniques needed to develop an SLA implementation for two‐dimensional (plane strain) problems are described in detail, including model geometry updating routines, treatment of rigid bodies, interfaces and boundaries, and periodic remeshing and interpolation of field variables. A simple total stress‐based constitutive model is used to account for strain softening and strain rate effects. Extensive verifications and validations are performed using analytical solutions and physical model test results, comparing both collapse loads and failure mechanisms, to demonstrate the effectiveness of the SLA approach. Additional solution quality checks on the bracketing discrepancy between lower‐bound and upper‐bound limit analysis solutions, and on the incompressibility of the rigid‐plastic material, are also presented.