bluuebunny/crossref_metadata_2025 huggingface dataset:
Non‐motor symptoms in early Parkinson's disease with different motor subtypes and their associations with quality of life
Authors: Huang X. , Ng S. Y.‐E. , Chia N. S.‐Y. , Setiawan F. , Tay K.‐Y. , Au W.‐L. , Tan E.‐K. , Tan L. C.‐S.
Published: September 2018

Background and purpose

The aim of this study was to examine non‐motor symptoms in different Parkinson's disease (PD) motor subtypes and their associations with quality of life (QoL).

Methods

A total of 132 patients with early PD with comprehensive motor examinations and non‐motor symptom assessments were included. Motor subtypes were classified based on Stebbins’ method. Non‐motor symptoms were assessed by the Non‐Motor Symptom Scale (NMSS) and validated by more comprehensive instruments, including the Pittsburgh Sleep Quality Index (PSQI) and Fatigue Severity Scale (FSS). QoL was measured by the Parkinson's Disease Questionnaire‐8.

Results

We identified 66 patients (50%) with tremor‐dominant (TD) subtype, 47 (35.6%) with postural instability and gait disorder (PIGD) subtype and 19 (14.4%) with Intermediate subtype. By comparing NMSS scores, patients with the PIGD subtype had more severe sleep impairment and fatigue (domain 2 score: 5.64 vs. 2.52, P < 0.001), urinary symptoms (domain 7 score: 6.96 vs. 3.48, P = 0.005) and overall more severe non‐motor symptoms (NMSS total score: 25.89 vs. 17.27, P = 0.031), compared with patients with the TD subtype. Validation using the PSQI and FSS again suggested that patients with the PIGD subtype had independently and significantly more severe sleep impairment (PSQI score: 5.57 vs. 4.29, P = 0.020) and fatigue (FSS score: 34.81 vs. 25.85, P = 0.003) compared with patients with the TD subtype. Several non‐motor symptoms had significant associations with QoL, among which sleep impairment and fatigue (P < 0.0001, partial r2 = 0.273) explained the largest proportion of QoL variability in patients with PD.

Conclusions

Patients with the PIGD subtype had more severe sleep impairment, fatigue and urinary disturbance compared with patients with the TD subtype. Sleep impairment and fatigue were the most important factors affecting QoL independent of motor subtypes. Prompt identification and treatment of these non‐motor symptoms may improve patients’ QoL.
The politics of social spending after the Great Recession: The return of partisan policy making
Authors: Savage Lee
Published: September 2018

Prior research shows that the effect of partisanship on social expenditure declined over time in Organisation for Economic Co‐operation and Development (OECD) countries. In this article, the author argues that the 2007/2008 recession resulted in the reemergence of partisan policy making in social spending. This was a result of mainstream parties needing to respond to the growing challenge from nonmainstream parties as well as demonstrating that they responded to the economic crisis by offering different policy solutions. Using a panel of 23 OECD countries, the author shows that since the Great Recession, partisan effects on social spending are once again significant. These effects are more likely to be observed where the salience of the Left–Right dimension is higher. In accordance with classic theories of economic policy making, left‐wing governments are more likely to increase social spending when unemployment is higher and right‐wing governments restrain social expenditure when the budget deficit is greater.
Experts, Expertise and Drug Policymaking
Authors: MONAGHAN MARK , WINCUP EMMA , WICKER KATE
Published: September 2018

Over the past two decades, policymakers have been encouraged to develop evidence‐based policies in collaboration with experts. Drug policy is unique since it has an established inbuilt mechanism for soliciting expertise via the Advisory Council for the Misuse of Drugs (ACMD). Increasingly alternative mechanisms have been used. Based upon detailed analysis of two case studies of drug policymaking using alternative methods to solicit expertise, we argue that the framing of the policy problem, the mechanisms used to involve experts and the type of evidence actively sought, have continued to marginalise the involvement of the drug user in policymaking.
Managerial Stock Ownership and Debt Diversification
Authors: Jadiyappa Nemiraja , Saikia Namrata , Parikh Bhavik
Published: September 2018

In this study, we examine the impact of managerial behavior on the debt diversification decisions of firms using the agency cost of debt framework. We hypothesize that managers with higher equity ownership should favor debt diversification to avoid efficient monitoring by debt holders and thus, be able to engage in risk‐shifting behavior. Our empirical results provide strong evidence for a positive association between managerial ownership and debt diversification. This relationship is observed to be stronger for smaller firms, which are traditionally more susceptible to the moral hazard problem. Our results remain robust for an alternate measure of debt diversification.
A risk model for the prediction of skin tears in aged care residents: A prospective cohort study
Authors: Rayner Robyn , Carville Keryln , Leslie Gavin , Dhaliwal Satvinder S.
Published: September 2018

The objective of this study was to construct a predictive model to identify aged care residents at risk of future skin tears. Extensive data about individual characteristics, skin characteristics, and skin properties were gathered from 173 participants at baseline and at 6 months. A predictive model, developed using multivariable logistic regression, identified five variables that significantly predicted the risk of skin tear at 6 months. These included: a history of skin tears in the previous 12 months (OR 3.82 [1.64‐8.90], P = 0.002), purpura ≤20 mm in size (OR 3.64 [1.42‐9.35], P = 0.007), a history of falls in the previous 3 months (OR 3.37 [1.54‐7.41], P = 0.002), clinical manifestations of elastosis (OR 3.19 [1.38‐7.38], P = 0.007), and male gender (OR 3.08 [1.22‐7.77], P = 0.017). The predictive model yielded an area under the receiver operating characteristic curve of 0.854 with an 81.7% sensitivity and an 81.4% specificity. This predictive model could inform a simple but promising bedside tool for identifying older individuals at risk of skin tears.
CaO‐MgO‐Al2O3‐SiO2 corrosion behavior of air‐plasma‐sprayed (LaxYb1−x)2Zr2O7
Authors: Wang Min , Lai Xinchun , Guo Sicong , Wang Ziyuan , Pan Wei
Published: September 2018

The CaO‐MgO‐Al2O3‐SiO2 (CMAS) corrosion of thermal barrier coatings (TBCs) is a crucial problem for the lifetime of blades and vanes of jet engine and gas turbine at high operating temperature. Although many new alternative materials for TBCs have been developed in recent years, their application is limited by the CMAS corrosion. On the other hand, the composition difference of CMAS between regions makes solving this problem very difficult. Therefore, in this study, the yearly composition changes of sand‐dust around Beijing area were investigated. The high‐temperature corrosion behavior of air‐plasma‐sprayed 8YSZ and newly developed (LaxYb1−x)2Zr2O7 TBCs by the representative sand‐dust of Beijing was investigated. In comparison, a universally used CaO‐riched composition of simulated silicate deposit was also adopted for the TBCs corrosion test. It is found that the (LaxYb1−x)2Zr2O7 TBCs performs much better anti‐corrosion behavior than that of 8YSZ, both by Beijing sand‐dust and simulated one. Particularly, Yb2Zr2O7 TBCs appear to be the optimum material against silicate deposits attack. The mechanism of silicate deposits corrosion has also been discussed.
Energy efficient spark plasma sintering: Breaking the threshold of large dimension tooling energy consumption
Authors: Manière Charles , Lee Geuntak , McKittrick Joanna , Olevsky Eugene A.
Published: September 2018

An energy efficient spark plasma sintering method enabling the densification of large size samples assisted by very low electric current levels is developed. In this method, the electric current is concentrated in the graphite foils around the sample. High‐energy dissipation is then achieved in this area enabling the heating and full densification of large (alumina) parts (Ø 40 mm) at relatively low currents (800 A). The electrothermal mechanical simulation reveals that the electric current needed to heat the large samples is 70% lower in the energy efficient configuration compared to the traditional configuration. The presence of thermal and densification gradients is also revealed for the larger size samples. Potential solutions for this problem are discussed. The experiments confirm the possibility of full densification (96%‐99%) of large alumina samples. This approach allows using small (and low cost) SPS devices (generally limited to 10‐15 mm samples) for large‐size samples (40‐50 mm). The developed technique enables also an optimized energy consumption by large‐scale SPS systems.
Four compartment method as an efficacious and simplified technique for autologous non‐cultured epidermal cell suspension preparation in vitiligo surgery: A randomized, active‐controlled study
Authors: Mrigpuri S. , Razmi T M. , Sendhil Kumaran M. , Vinay K. , Srivastava N. , Parsad D.
Published: September 2018

Background

Autologous non‐cultured epidermal cell suspension (NCES) is a successful surgical method for repigmentation of stable, refractory vitiligo. The need for laboratory equipment and expertise restricts its use to only a few research centres; hence, there is a requisite to simplify the technique of NCES preparation.

Objectives

To evaluate the efficacy of NCES prepared by four compartment (4C) method compared to the laboratory‐based method (lab‐NCES).

Methods

Anatomically based matched lesions (41 pairs) in 30 stable vitiligo patients were randomized to receive NCES prepared by 4C method or lab‐NCES. Each patient was evaluated at 4, 8, 16 weeks after surgery by a blinded observer with regard to extent of repigmentation, colour match, patient global assessment (PGA) and pattern of repigmentation.

Results

Repigmentation outcome in 4C method as compared to lab‐NCES was as follows: excellent (≥90%) repigmentation: 34% vs. 37%, P = 1.000, good (≥75%) repigmentation: 68% vs. 71%, P = 1.000; colour match: 59% vs. 54%, P = 0.794, patient satisfaction based on PGA score – 23.02 vs. 23.39 (P = 0.210) and major pattern of repigmentation (diffuse) – 76% vs. 71% (P = 0.618).

Limitations

Short follow‐up period of 16 weeks.

Conclusion

Four compartment method is a simple and effective technique for vitiligo surgery in routine clinical practice.
The Impact of Multidimensionality on Extraction of Latent Classes in Mixture Rasch Models
Authors: Jang Yoonsun , Kim Seock‐Ho , Cohen Allan S.
Published: September 2018

This study investigates the effect of multidimensionality on extraction of latent classes in mixture Rasch models. In this study, two‐dimensional data were generated under varying conditions. The two‐dimensional data sets were analyzed with one‐ to five‐class mixture Rasch models. Results of the simulation study indicate the mixture Rasch model tended to extract more latent classes than the number of dimensions simulated, particularly when the multidimensional structure of the data was more complex. In addition, the number of extracted latent classes decreased as the dimensions were more highly correlated regardless of multidimensional structure. An analysis of the empirical multidimensional data also shows that the number of latent classes extracted by the mixture Rasch model is larger than the number of dimensions measured by the test.
A Comparison of Procedures for Estimating Person Reliability Parameters in the Graded Response Model
Authors: LaHuis David M. , Bryant‐Lees Kinsey B. , Hakoyama Shotaro , Barnes Tyler , Wiemann Andrea
Published: September 2018

Person reliability parameters (PRPs) model temporary changes in individuals’ attribute level perceptions when responding to self‐report items (higher levels of PRPs represent less fluctuation). PRPs could be useful in measuring careless responding and traitedness. However, it is unclear how well current procedures for estimating PRPs can recover parameter estimates. This study assesses these procedures in terms of mean error (ME), average absolute difference (AAD), and reliability using simulated data with known values. Several prior distributions for PRPs were compared across a number of conditions. Overall, our results revealed little differences between using the χ or lognormal distributions as priors for estimated PRPs. Both distributions produced estimates with reasonable levels of ME; however, the AAD of the estimates was high. AAD did improve slightly as the number of items increased, suggesting that increasing the number of items would ameliorate this problem. Similarly, a larger number of items were necessary to produce reasonable levels of reliability. Based on our results, several conclusions are drawn and implications for future research are discussed.
Cholangiocarcinoma in Germany: Epidemiologic trends and impact of misclassification
Authors: Walter Dirk , Ferstl Philip , Waidmann Oliver , Trojan Jörg , Hartmann Sylvia , Schnitzbauer Andreas A. , Zeuzem Stefan , Kraywinkel Klaus
Published: September 2018

Background & Aims

Diverging trends of cholangiocarcinoma (CCA) incidence in different countries warrant further subtype‐specific characterization. In this study, we aimed to determine current epidemiologic trends of CCA in Germany and evaluated impact of misclassification of perihilar CCA (pCCA) as intrahepatic CCA (iCCA).

Methods

Subtype‐specific incidence was assessed based on data of approximately 40 million German citizens from 2003 to 2014, and mortality data of entire Germany were assessed from 1998 to 2015.

Results

Reclassification of pCCA to extrahepatic CCA (eCCA) led to an enhancement of an increasing average annual percentage change (AAPC) for iCCA in men (3.8 to 4.8) and women (3.3 to 4.8). Likewise, a stable or slightly decreasing trend in extrahepatic CCA was strengthened in women (AAPC: −0.2 to −0.9) and men (1 to 0.5). pCCA accounted for 13% of biliary tract tumours (iCCA: 46%, distal CCA: 41%). In line with incidence trends, mortality of iCCA in Germany increased for women (AAPC 7.8) and men (6.5), while it was stable for eCCA (women: −0.6, men: 2.1).

Conclusion

Incidence of iCCA in Germany is increasing while it is stable for eCCA. Misclassification of pCCA as iCCA is present, but clearly declining.
Relationship between non‐alcoholic steatohepatitis, PNPLA3 I148M genotype and bone mineral density in adolescents
Authors: Mosca Antonella , Fintini Danilo , Scorletti Elenora , Cappa Marco , Paone Laura , Zicari Anna M. , Nobili Valerio , Byrne Christopher D.
Published: September 2018

Background & Aims

It is uncertain whether non‐alcoholic steatohepatitis (NASH) is a risk factor for low bone mineral density (BMD). Our aim was to investigate: (a) associations between NASH and BMD values and (b) associations between PNPLA3 I148M genotypes and BMD, in children with histologically proven non‐alcoholic fatty liver disease (NAFLD).

Methods

BMD area (g/cm2) was measured using dual‐energy X‐ray absorptiometry (DEXA). NASH was diagnosed by a Steatosis, Activity and Fibrosis (SAF) score and FLIP algorithm. Genotyping for patatin‐like phospholipase domain containing‐3 (PNPLA3) I148M genotype (rs738409) (CC, CG and GG) was undertaken using the TaqMan SNP genotyping allelic discrimination method. Logistic regression was used to test associations [OR (95% CIs)] between low BMD, and both NASH and PNPLA3 I148M genotypes.

Results

Thirty‐four adolescents (mean age 13.8 ± 1.1 years) with histologically confirmed NAFLD were studied. Subjects with NASH (n = 25) had a lower BMD (means (SDs) 0.87 ± 0.06 vs 0.97 ± 0.12, P = 0.005), compared to subjects without NASH. Subjects with PNPLA3 CG+GG genotypes had a lower BMD compared with subjects with PNPLA3‐CC genotype (means (SDs) 0.79 ± 0.20 vs 0.92 ± 0.10, P = 0.009). PNPLA3 CG+GG genotypes were independently associated with NASH [OR (95% CIs 1.78, 1.24, 2.99)], and low BMD was associated with both PNPLA3 CG+GG (OR 3.62 (95% CIs 1.21, 5.53), P = 0.028) and with SAF score (OR 2.76 (95% CIs 1.12, 5.41), P = 0.045).

Conclusions

Taken together the independent associations between: (a) low BMD and PNPLA3 CG+GG genotype; (b) low BMD and NASH; and (c) PNPLA3 CG+GG genotype and NASH, provide support for a causal relationship between NASH and low BMD.
Current conservation status and reproductive biology of the giant tree Rhododendron in China
Authors: Li Shenghui , Sun Weibang , Ma Yongpeng
Published: September 2018

The conservation status and pollination biology of Rhododendron protistum var. giganteum Balf.f. & Forrest, a plant taxon with an extremely small population size, was investigated in western Yunnan from 2014 to 2016. In addition to two previously reported populations, 7 more populations were found in the Gaoligong Mountain National Nature Reserve. Floral traits, including flowering time, floral morphology, petal color reflectance and flower scents, were assessed, and the associated probable pollinator assemblies were recorded. The flowering period of R. protistum var. giganteum was from late January to early March and a single flower can last 14–16 days in its natural habitat. Bombus and two genera of birds, Aethopyga and Dicaeum, were observed to be floral visitors, representing 75% and 25% of total recorded flower visits respectively. Floral scents matched the vegetative parts scent, indicating that scent is unlikely to be of importance in attracting pollinators, but the red flower color suggests ornithophilous pollination. A marked peak in the reflectance spectrum at 436 nm was observed, providing further evidence for bumblebee pollination. Pollination treatments indicated that pollen limitation was not severe in R. protistum var. giganteum. Overall, our preliminary report provides basic information and facilitates further conservation of R. protistum var. giganteum.
A high‐density EEG study of differentiation between two speeds and directions of simulated optic flow in adults and infants
Authors: Vilhelmsen Kenneth , Agyei Seth B. , van der Weel F. R. (Ruud) , van der Meer Audrey L. H.
Published: September 2018

A high‐density EEG study was carried out to investigate cortical activity in response to forward and backward visual motion at two different driving speeds, simulated through optic flow. Participants were prelocomotor infants at the age of 4–5 months and infants with at least 3 weeks of crawling experience at the age of 8–11 months, and adults. Adults displayed shorter N2 latencies in response to forward as opposed to backward visual motion and differentiated significantly between low and high speeds, with shorter latencies for low speeds. Only infants at 8–11 months displayed similar latency differences between motion directions, and exclusively in response to low speed. The developmental differences in latency between infant groups are interpreted in terms of a combination of increased experience with self‐produced locomotion and neurobiological development. Analyses of temporal spectral evolution (TSE, time‐dependent amplitude changes) were also performed to investigate nonphase‐locked changes at lower frequencies in underlying neuronal networks. TSE showed event‐related desynchronization activity in response to visual motion for infants compared to adults. The poorer responses in infants are probably related to immaturity of the dorsal visual stream specialized in the processing of visual motion and could explain the observed problems in infants with differentiating high speeds of up to 50 km/h.
A typology of board design for highly effective monitoring in intergovernmental organizations under the United Nations system
Authors: Federo Ryan , Saz‐Carranza Angel
Published: September 2018

The United Nations (UN) system comprises several intergovernmental organizations (IGOs) that were established to contribute to the functioning of the overall transnational system of delivering global public goods. However, many IGOs under the UN system are criticized for their failure to accomplish their mandates. Research argues that IGO boards serve as a governance mechanism that should be designed in order to effectively perform the monitoring function to ensure fulfillment of IGO mandates. Thus, using an inductive fuzzy set qualitative comparative analysis, this study explores 13 IGO boards under the UN system to identify the board designs that are associated with highly effective monitoring. Our findings reveal a board design typology reflecting the interplay of the level of organizational complexity and the extent of the distribution problem in IGOs. This research contributes to our understanding of IGO governance by underscoring the relationship between board designs and highly effective monitoring to help researchers and practitioners improve IGO performance.
The Effects of Customer Satisfaction on Company Profitability: Evidence From the Property and Casualty Insurance Industry
Authors: Pooser David M. , Browne Mark J.
Published: September 2018

Prior literature presents a positive link between customer satisfaction and firms’ financial outcomes, including greater revenue, profitability, and prices. However, few studies approach the topic of customer satisfaction in the insurance industry. Using a unique data set obtained from J.D. Power, we observe customer satisfaction among U.S. auto insurers and link their customer satisfaction rating to insurer profitability metrics. Our results support the notion that greater customer satisfaction leads to reduced expenses and increased profitability. A potential explanation is that more satisfied customers are more likely to remain with an insurance company and refer others to the insurer, reducing customer acquisition expenses.
Undoing segmentation? Latin American health care policy during the economic boom
Authors: Martínez Franzoni Juliana , Sánchez‐Ancochea Diego
Published: September 2018

For all the agreement regarding the segmented character of Latin America's social policy, few studies define it clearly, let alone suggest exact ways to measure it. This article provides a more precise definition based on a threefold policy output comprising coverage, generosity, and equity. Empirically, the article explores the cross‐national variation in segmentation in health care within Latin America in 2000 and 2013, before and after Latin America's economic boom. The article clusters countries, evaluates which ones improved their relative position during the 2000s, and determines the overall level of segmentation in the region. Findings are twofold. First, we identify three clusters: countries that respectively do particularly well and poorly across policy dimensions in 2000 and 2013, and a smaller set of countries that improved significantly, particularly regarding coverage and generosity. Second, despite cross‐national differences, there are shared regional challenges—the risk of catastrophic expenditure being a case in point. Our analysis demonstrates the need to move beyond coverage as a policy goal and pay more attention to gaps in generosity in every country. We also call for better indicators to measure performance beyond coverage across countries, and more studies that explain the similarities and differences between countries that improved considerably during the 2000s.
Strategic Content: Representations of Epistemic Modality in Biosemantics (and Success Semantics)
Authors: Björnsson Gunnar
Published: September 2018

A central idea in Ruth Millikan's biosemantics is that a representation's content is restricted to conditions required for the normal success of actions that it has as its function to guide. This article raises and responds to a problem for this idea. The problem is that the success requirement seems to block us from saying that epistemic modal judgements represent our epistemic circumstances. For the normal success of actions guided by these judgements seems to depend on what is actually the case, not on whether or to what extent various possibilities were supported by the evidence. In response, I argue, first, that actions guided by epistemic modal judgements have as their function to implement strategies for handling epistemic circumstances, second, that the successful performance of this function requires that aspects of these circumstances obtain, and, third, that biosemantics can thus understand epistemic modal judgements as representing these aspects. The recognition of such strategic contents introduces complications; I further argue that these are benign.
Burden of dengue among febrile patients at the time of chikungunya introduction in Piedecuesta, Colombia
Authors: Carabali Mabel , Lim Jacqueline K. , Palencia Diana C. , Lozano‐Parra Anyela , Gelvez Rosa Margarita , Lee Kang Sung , Florez Janeth P. , Herrera Victor Mauricio , Kaufman Jay S. , Rojas Elsa M. , Villar Luis Angel
Published: September 2018

Objective

To estimate the age‐specific incidence of symptomatic dengue and chikungunya in Colombia.

Method

A passive facility‐based fever surveillance study was conducted among individuals with undifferentiated fever. Confirmatory diagnostics included serological and molecular tests in paired samples, and surveillance's underreporting was assessed using capture–recapture methods.

Results

Of 839 febrile participants 686 completed the study. There were 33.2% (295/839) dengue infections (51% primary infections), and 35.9% (191/532) of negative dengue cases there were chikungunya cases. On average, dengue cases were younger (median = 18 years) than chikungunya cases (median = 25 years). Thrombocytopaenia and abdominal pain were the main dengue predictors, while presence of rash was the main predictor for chikungunya diagnosis. Underreporting of dengue was 31%; the estimated expansion factors indicate an underreporting rate of dengue cases of threefold for all cases and of almost sixfold for inpatients.

Conclusions

These findings highlight the ongoing coexistence of both arboviruses, a distinct clinical profile of each condition in the study area that could be used by clinicians to generate a differential diagnosis, and the presence of underreporting, mostly among hospitalised cases.
Numerical
Simulation of Fluid Flow and Heat Transfer in a Ductile Iron Ladle During Holding and
Teeming
Authors: Gopala Krishna E.
D. , Shamshoddin Shaik , Ande Raghu
Published: September 2018

A 3D transient numerical model of a ductile iron ladle has been developed to predict the fluid flow and temperature drop during the holding and teeming. The volume of fluid (VOF) multiphase model has been employed to track the interface between the liquid metal and the air. The SST k-ω model has been applied to model the turbulence due to natural convection in the ladle. The temperature evaluation in the refractory lining walls during preheating and teeming is shown. Appropriate boundary conditions are applied for natural convection and radiation to surroundings from all the outer steel surfaces as well as from the top glass wool cover. The heat loss due to radiation from the liquid metal surface to the surrounding walls is also considered in the present model by applying an energy sink term to the cells at the interface. The numerical results of the 780 kg ladle have been compared with the measured temperature drop of the metal using an S-type thermocouple for two ladle cycles and the difference between the measured and predicted temperature at the end of two cycles is 3 °C. Decreasing the ladle capacity to 650 kg for pouring the same amount of metal increased the temperature drop by 11 °C due to increase in surface area to melt volume ratio. Also increasing the refractory thickness for 650 kg ladle increased the temperature drop by 4 °C due to the heat accumulation in the ladle during the cyclic transient heat transfer process.
Framework of Reliability-Based Stochastic Mobility Map for Next Generation NATO Reference Mobility Model
Authors: Choi K. K. , Jayakumar Paramsothy , Funk Matthew , Gaul Nicholas , Wasfy Tamer M.
Published: September 2018

A framework for generation of reliability-based stochastic off-road mobility maps is developed to support the next generation NATO reference mobility model (NG-NRMM) using full stochastic knowledge of terrain properties and modern complex terramechanics modeling and simulation capabilities. The framework is for carrying out uncertainty quantification (UQ) and reliability assessment for Speed Made Good and GO/NOGO decisions for the ground vehicle based on the input variability models of the terrain elevation and soil property parameters. To generate the distribution of the slope at given point, realizations of the elevation raster are generated using the normal distribution. For the soil property parameters, such as cohesion, friction, and bulk density, the min and max values obtained from geotechnical databases for each of the soil types are used to generate the normal distribution with a 99% confidence value range. In the framework, the ranges of terramechanics input parameters that will cover the regions of interest are first identified. Within these ranges of input parameters, a dynamic kriging (DKG) surrogate model is obtained for the maximum speed of the nevada automotive test center (NATC) wheeled vehicle platform complex terramechanics model. Finally, inverse reliability analysis using Monte Carlo simulation is carried out to generate the reliability-based stochastic mobility maps for Speed Made Good and GO/NOGO decisions. It is found that the deterministic map of the region of interest has probability of only 25% to achieve the indicated speed.
Identification of Plastic Properties From Conical Indentation Using a Bayesian-Type Statistical Approach
Authors: Zhang Yupeng , Hart Jeffrey D. , Needleman Alan
Published: September 2018

The plastic properties that characterize the uniaxial stress–strain response of a plastically isotropic material are not uniquely related to the indentation force versus indentation depth response. We consider results for three sets of plastic material properties that give rise to essentially identical curves of indentation force versus indentation depth in conical indentation. The corresponding surface profiles after unloading are also calculated. These computed results are regarded as the “experimental” data. A simplified Bayesian-type statistical approach is used to identify the values of flow strength and strain hardening exponent for each of the three sets of material parameters. The effect of fluctuations (“noise”) superposed on the “experimental” data is also considered. We build the database for the Bayesian-type analysis using finite element calculations for a relatively coarse set of parameter values and use interpolation to refine the database. A good estimate of the uniaxial stress–strain response is obtained for each material both in the absence of fluctuations and in the presence of sufficiently small fluctuations. Since the indentation force versus indentation depth response for the three materials is nearly identical, the predicted uniaxial stress–strain response obtained using only surface profile data differs little from what is obtained using both indentation force versus indentation depth and surface profile data. The sensitivity of the representation of the predicted uniaxial stress–strain response to fluctuations increases with increasing strain hardening. We also explore the sensitivity of the predictions to the degree of database refinement.
Improved Internal Model Control-Proportional-Integral- Derivative Fractional-Order Multiloop Controller Design for Non Integer Order Multivariable Systems
Authors: Chekari Tassadit , Mansouri Rachid , Bettayeb Maamar
Published: September 2018

This paper is aimed to propose a multiloop control scheme for fractional order multi-input multi-output (FO-MIMO) systems. It is an extension of the FO-multiloop controller design method developed for integer order multivariable systems to FO-MIMO ones. The interactions among the control loops are considered as disturbances and a two degrees-of-freedom (2DOF) paradigm is used to deal with the process outputs performance and the interactions reduction effect, separately. The proposed controller design method is simple, in relation with the desired closed-loop specifications and a tuning parameter. It presents an interest in controlling complex MIMO systems since fractional order models (FO-models) represent some real processes better than integer order ones and high order systems can be approximated by FO-models. Two examples are considered and compared with other existing methods to evaluate the proposed controller.
Model Predictive Static Programming for Optimal Command Tracking: A Fast Model Predictive Control Paradigm
Authors: Kumar Prem , Anoohya B. Bhavya , Padhi Radhakant
Published: September 2018

Inspired by fast model predictive control (MPC), a new nonlinear optimal command tracking technique is presented in this paper, which is named as “Tracking-oriented Model Predictive Static Programming (T-MPSP).” Like MPC, a model-based prediction-correction approach is adopted. However, the entire problem is converted to a very low-dimensional “static programming” problem from which the control history update is computed in closed-form. Moreover, the necessary sensitivity matrices (which are the backbone of the algorithm) are computed recursively. These two salient features make the computational process highly efficient, thereby making it suitable for implementation in real time. A trajectory tracking problem of a two-wheel differential drive mobile robot is presented to validate and demonstrate the proposed philosophy. The simulation studies are very close to realistic scenario by incorporating disturbance input, parameter uncertainty, feedback sensor noise, time delays, state constraints, and control constraints. The algorithm has been implemented on a real hardware and the experimental validation corroborates the simulation results.
A Calculation Method to Investigate the Effects of Geometric Parameters and Operational Conditions on the Static Characteristics of Aerostatic Spherical Bearings
Authors: Cui Hailong , Xia Huan , Lei Dajiang , Zhang Xinjiang , Jiang Zhengyi
Published: September 2018

In this paper, a calculation method based on matlab partial differential equations (PDE) tool is proposed to investigate the static characteristics of aerostatic spherical bearings. The Reynolds equation of aerostatic spherical bearings is transformed into a standard elliptic equation. The effects of geometric parameters and operational conditions on the film pressure, bearing film force, and stiffness are studied. The axial and radial eccentricities result in different film pressure distributions; the bearing film force and stiffness are significantly influenced by geometric parameters and operational conditions. The relative optimal parameters are confirmed based on the calculation results. A comparison between the numerical and experimental results is also presented. The highest relative error between the numerical results and the experimental data is 11.3%; the calculation results show good agreements with the experimental data, thus verifying the accuracy of the calculation method used in this paper.
Experimental Study on Pressure Losses in Porous Materials
Authors: Fantozzi Giacomo , Kinell Mats , Rabal Carrera Sara , Nilsson Jenny , Kuesters Yves
Published: September 2018

Recent technological advances in the field of additive manufacturing have made possible to manufacture turbine engine components characterized by controlled permeability in desired areas. These have shown great potential in cooling application such as convective cooling and transpiration cooling and may in the future contribute to an increase of the turbine inlet temperature. This study investigates the effects of the pressure ratio, the thickness of the porous material and the hatch distance used during manufacturing on the discharge coefficient. Moreover, two different porous structures were tested and in total 70 test objects were investigated.

Using a scanning electron microscope, it is shown that the porosity and pore radius distribution, which are a result from the used laser power, laser speed and hatch distance during manufacturing, will characterize the pressure losses in the porous sample. Furthermore, the discharge coefficient increases with increasing pressure ratio, while it decreases with increasing thickness to diameter ratio.

The obtained experimental data was used to develop a correlation for the discharge coefficient as a function of the geometrical properties and the pressure ratio.
Quasi-Static Thermal Modelling of Multi-Scale Sliding Contact for Unlubricated Brush Seal Materials
Authors: Xia Qingfeng , Gillespie David , Owen Andrew , Franceschini Gervas
Published: September 2018

Prediction of the contact temperature between two materials in high speed rubbing contact is essential when analysing the wear mechanism and modelling wear rate for unlubricated contact. Conventionally the assumptions used for a pin-on-disc configuration are either a steady heat source at the contact for slow speed rotation or an annular source along the rubbing track at high rotating speeds. In this paper, the rotating heating source is solved using an in-house finite element method (FEM) code. This captures the full geometry and rotating speed of the rubbing bodies. The transient heat transfer problem is modelled in a quasi-static way: eliminating the computational cost of a transient 3D simulation. This reduced-order model is analytically shown to be suitable for contact temperature prediction over a wide range of rotating speeds, anisotropic thermal conductivity, and non-uniform thermal boundary conditions. The model calculates heat partition accurately for a thin rotating disc and short pin combination, which cannot be predicted using existing analytical solutions. The quasi-static numerical model and in-house FEM solver are validated against Ansys Mechanical and experimental measurements using infrared thermography. The numerical result demonstrates that the annular source assumption can significantly under-predict the contact temperature, especially at the rubbing interface. Explicit modelling of a thin disc results in a higher heat partition coefficient compared with the commonplace semi-infinite length assumption on both static and rotating components. Furthermore, the thermal anisotropy for bristle tufts is numerically evaluated, and the tuft-on-disc configuration is compared to the pin-on-disc configuration. Despite the effective thermal conductivity in the bristle tuft being approximately one order of magnitude lower than along the bristle length (treating the bristle as a porous medium), its impact on heat partition and contact temperature is shown to be limited.
Very-Large Eddy Simulations of Disk Heat Transfer in a Rotating Cavity Using Lattice-Boltzmann Method
Authors: Kouwa J. , Iso Y. , Polidoro F. , Gautier S.
Published: September 2018

Convective heat transfer in the cavity between two corotating disks is of great importance for turbomachinery applications. The complex three dimensional and unsteady flow structures induced by the Coriolis forces inside the cavity, and therefore the resulting heat transfer, are challenging to be measured in an experiment or predicted by simulation. In this paper a simplified cavity geometry, characterized experimentally by Long at al., has been chosen. The results obtained with a Very Large Eddy Simulation using Lattice-Boltzmann Method for two operating point with different rotation speeds are compared to the experimental heat transfer coefficients at the wall. The simulation results show the characteristic flow structures and behavior induced by the different regimes. A sensitivity analysis of the results is presented, both for numerical parameters such as grid resolution and for physical parameters, namely the throughflow velocity profile and shroud temperature.
Attributable Cost and Length of Stay Associated with Nosocomial Gram-Negative Bacterial Cultures
Authors: Nelson Richard E. , Stevens Vanessa W. , Jones Makoto , Khader Karim , Schweizer Marin L. , Perencevich Eli N. , Rubin Michael A. , Samore Matthew H.
Published: September 2018

Few studies have estimated the excess inpatient costs due to nosocomial cultures of Gram-negative bacteria (GNB), and those that do are often subject to time-dependent bias. Our objective was to generate estimates of the attributable costs of the underlying infections associated with nosocomial cultures by using a unique inpatient cost data set from the U.S.
Argentilactone Molecular Targets in Paracoccidioides brasiliensis Identified by Chemoproteomics
Authors: Silva Lívia do Carmo , Tauhata Sinji Borges Ferreira , Baeza Lilian Cristiane , de Oliveira Cecília Maria Alves , Kato Lucília , Borges Clayton Luiz , de Almeida Soares Célia Maria , Pereira Maristela
Published: September 2018

Paracoccidioidomycosis (PCM) is the cause of many deaths from systemic mycoses. The etiological agents of PCM belong to the
Paracoccidioides
genus, which is restricted to Latin America.
Impacts of L1 Promoter Variation and L2 Clavulanate Susceptibility on Ticarcillin-Clavulanate Susceptibility of Stenotrophomonas maltophilia
Authors: Huang Hsin-Hui , Chen Peng-Ying , Hu Rouh-Mei , Lin Yi-Tsung , Li Li-Hua , Yang Tsuey-Ching
Published: September 2018

Inducible expression of L1 and L2 β-lactamases is the principal mechanism responsible for β-lactam resistance in
Stenotrophomonas maltophilia
. Ticarcillin-clavulanate (TIM) is one of the few effective β-lactams for
S. maltophilia
treatment.
Modeling Host-Pathogen Interactions in the Context of the Microenvironment: Three-Dimensional Cell Culture Comes of Age
Authors: Barrila Jennifer , Crabbé Aurélie , Yang Jiseon , Franco Karla , Nydam Seth D. , Forsyth Rebecca J. , Davis Richard R. , Gangaraju Sandhya , Ott C. Mark , Coyne Carolyn B. , Bissell Mina J. , Nickerson Cheryl A.
Published: September 2018

Tissues and organs provide the structural and biochemical landscapes upon which microbial pathogens and commensals function to regulate health and disease. While flat two-dimensional (2-D) monolayers composed of a single cell type have provided important insight into understanding host-pathogen interactions and infectious disease mechanisms, these reductionist models lack many essential features present in the native host microenvironment that are known to regulate infection, including three-dimensional (3-D) architecture, multicellular complexity, commensal microbiota, gas exchange and nutrient gradients, and physiologically relevant biomechanical forces (e.g., fluid shear, stretch, compression).
Microcatheter navigation through the clot: does size matter?
Authors: Caroff Jildaz , King Robert M , Arslanian Rose , Marosfoi Miklos , Langan Erin T , Gounis Matthew J , Chueh Ju-Yu
Published: September 2018

Background

Despite high recanalization rates achieved with endovascular treatment of acute ischemic strokes, around 50% of eligible patients will not achieve a good outcome. Parameters that may determine patient outcomes include: time from puncture to recanalization, the collateral status, the anesthesia regimen, blood pressure management, and distal emboli. Characterization of distal emboli generated during mechanical thrombectomy has been performed in previous studies.

Objective

To further investigate the risk of distal embolization associated with microcatheter navigation across the clot.

Methods

A contrast-enhanced clot analog was used in an in vitro model that mimicked a middle cerebral artery occlusion within a complete circle of Willis vascular replica. The clot was crossed with one of the following microcatheters: Pro18, XT-27 or 3MAX. The emboli generated during the procedure were collected and measured.

Results

The use of Pro18 and XT-27 resulted in a significant reduction of visible particles (size ≥500 µm) as compared with the 3MAX catheter (P<0.003). For the size range between 8 and 200 µm, there was a trend for Pro18 to generate fewer particles (−18%) than XT-27 but without statistical significance (P>0.05). In comparison with previously published data, acquired under the same conditions, it was found that the clot crossing maneuver accounts approximately for 12% of the total number of small emboli (<200 µm) induced during a stent retriever-mediated mechanical thrombectomy procedure via a balloon guide catheter.

Conclusions

The clot crossing maneuver has a significant effect on the total number of small particles induced during mechanical thrombectomy. Smaller microcatheter sizes should be favored when possible.
Phase space formulation of density operator for non-Hermitian Hamiltonians and its application in quantum theory of decay
Authors: Praxmeyer Ludmila , Zloshchastiev Konstantin G.
Published: September 2018

The Wigner–Weyl transform and phase space formulation of a density matrix approach are applied to a non-Hermitian model which is quadratic in positions and momenta. We show that in the presence of a quantum environment or reservoir, mean lifetime and decay constants of quantum systems do not necessarily take arbitrary values, but could become functions of energy eigenvalues and have a discrete spectrum. It is demonstrated also that a constraint upon mean lifetime and energy appears, which is used to derive the resonance conditions at which long-lived states occur. The latter indicate that quantum dissipative effects do not always lead to decay but, under certain conditions, can support stability of a system.
Enhancing visible light photocatalytic activity of bismuth vanadate with the loading of zinc oxide
Authors: Liang Mengjun , Chen Lu , Yang Zhiyuan , Zeng Zhen , Yang Shuijin
Published: September 2018

ZnO/Bi4V2O[Formula: see text] nanocomposites were prepared via a facile hydrothermal method by loading different amounts of ZnO onto the surface of Bi4V2O[Formula: see text]. The resulting ZnO/Bi4V2O[Formula: see text] composites showed excellent photocatalytic activity than that of pure ZnO under visible light irradiation. When the ratio of ZnO to Bi4V2O[Formula: see text] was 1:1 (ZB2), the photocatalytic activity was best, which could degrade RhB almost completely within 30[Formula: see text]min. The enhanced photocatalytic activity of ZnO/Bi4V2O[Formula: see text] composites could be mainly ascribed to the efficient charge separation and the increased specific surface area. Based on the experimental and bandgap calculations, a possible photocatalytic mechanism was proposed.
List injective coloring of a class of planar graphs without short cycles
Authors: Bu Yuehua , Huang Chaoyuan
Published: September 2018

An injective [Formula: see text]-coloring of a graph [Formula: see text] is a mapping c: [Formula: see text]([Formula: see text]) [Formula: see text][Formula: see text] such that [Formula: see text] whenever [Formula: see text] have a common neighbor in [Formula: see text]. A list assignment of a graph [Formula: see text] is a mapping [Formula: see text] that assigns a color list [Formula: see text] to each vertex [Formula: see text]. Given a list assignment [Formula: see text] of [Formula: see text], an injective coloring [Formula: see text] of [Formula: see text] is called an injective [Formula: see text]-coloring if [Formula: see text] for every [Formula: see text]. In this paper, we show that if [Formula: see text] is a planar graph with girth [Formula: see text], then [Formula: see text] if [Formula: see text].