bluuebunny/crossref_metadata_2025 huggingface dataset:
Force Anticipation and Its Potential Implications on Feedforward and Feedback Human Motor Control
Authors: Kimpara Hideyuki , Mbanisi Kenechukwu C. , Li Zhi , Troy Karen L. , Prokhorov Danil , Gennert Michael A.
Published: March 2020

Objective

To investigate the effects of human force anticipation, we conducted an experimental load-pushing task with diverse combinations of informed and actual loading weights.

Background

Human motor control tends to rely upon the anticipated workload to plan the force to exert, particularly in fast tasks such as pushing objects in less than 1 s. The motion and force responses in such tasks may depend on the anticipated resistive forces, based on a learning process.

Method

Pushing performances of 135 trials were obtained from 9 participants. We varied the workload by changing the masses from 0.2 to 5 kg. To influence anticipation, participants were shown a display of the workload that was either correct or incorrect. We collected the motion and force data, as well as electromyography (EMG) signals from the actively used muscle groups.

Results

Overanticipation produced overshoot performances in more than 80% of trials. Lighter actual workloads were also associated with overshoot. Pushing behaviors with heavier workloads could be classified into feedforward-dominant and feedback-dominant responses based on the timing of force, motion, and EMG responses. In addition, we found that the preceding trial condition affected the performance of the subsequent trial.

Conclusion

Our results show that the first peak of the pushing force increases consistently with anticipatory workload.

Application

This study improves our understanding of human motion control and can be applied to situations such as simulating interactions between drivers and assistive systems in intelligent vehicles.
The stories that make us: Leaders’ origin stories and temporal identity work
Authors: Zheng Wei , Meister Alyson , Caza Brianna Barker
Published: March 2020

The stories we tell about our origins can shape how we think and act – helping us make sense of and communicate who we have “become” over time. To better understand the role that origin stories play in individuals’ work lives, we explore how 92 men and women leaders make sense of “becoming” a leader (origin stories) and “doing” leadership (enactment stories). We find that, despite the uniqueness of their experiences, their narratives converge around four frames, being, engaging, performing, and accepting, through which they understand, articulate, and enact their leader identities. We theorize that these narrative frames serve as sensemaking and identity work devices which allow them to create temporal coherence, validate their leader identity claims, and offer them behavioral scripts. Our findings also unearth key gender differences in the use of these frames, in that men used the performing frame more often and women tended toward the engaging frame. These findings provide novel insights into the ways in which the gendered context of leadership becomes embedded in leaders’ understandings of who they are and what they intend to do in their roles. We discuss the theoretical implications of our findings on scholarly conversations around identity, leadership, and gender.
Continuity and Change in the US–China–Taiwan Relations
Authors: Hsieh John Fuh-sheng
Published: March 2020

The relations between China and Taiwan (cross-Strait relations) have been a thorny issue for all parties concerned. These relations are one of the flashpoints in the world, which may trigger a serious military conflict. They involve not only China and Taiwan but also the United States. The purpose of this paper is to account for the trajectory of this triangular relationship with the help of opinion surveys in Taiwan. It is shown that when the Kuomintang (KMT) gains the governing power in Taiwan, Taiwan is the median voter in the cross-Strait relations game at the international level while as a non-traditional KMT or the Democratic Progressive Party is in power, it is the US that turns out to be the median voter.
Gradual Disappearance of Gender Disparity in Human Capital Accumulation: Evidence from India
Authors: Chaudhury Anjan Ray , Sinha Madhabendra
Published: March 2020

This study examines the existence and persistence of gender disparity in education in rural and urban India. We use the sequential logit model of regression on data sets provided by three rounds of quinquennial employment and unemployment surveys conducted by the National Sample Survey Office (NSSO). The findings of the study reveal that in both rural and urban sectors of India there is gender group disparity, and this disparity is greater in the rural sector than in the urban areas. Furthermore, it is also found that the gender groups’ disparity in education in India has substantially changed during the last two decades across both sectors.
Men’s Hostile Sexism and Biased Perceptions of Partners’ Support: Underestimating Dependability Rather Than Overestimating Challenges to Dominance
Authors: Hammond Matthew D. , Overall Nickola C.
Published: March 2020

Hostile sexism expresses derogation of women’s competence and emphasizes that women will exploit men’s relational dependence. Men who endorse hostile sexism perceive their female partners more negatively, but do these negative perceptions stem from motives for dominance or insecurities about dependence? We tested both perspectives by assessing bias in perceptions of partners’ behaviors that challenge dominance (criticism, instruction, taking over) versus affirm partners are dependable (love, care, availability). Both members of 100 heterosexual couples reported how much they received and enacted these behaviors in (a) a lab-based discussion and (b) six monthly retrospective reports about an ongoing important goal. In both support contexts, men’s hostile sexism was associated with underestimating dependability-relevant support, particularly when partners reported providing low support. This pattern did not emerge for dominance-relevant behaviors. These results indicate that men’s hostile sexism involves insecurities about dependence, producing perceptions that female partners are less dependable than they actually are.
Using Bayesian Nonparametric Item Response Function Estimation to Check Parametric Model Fit
Authors: Wang Wenhao , Kingston Neal
Published: March 2020

Previous studies indicated that the assumption of logistic form of parametric item response functions (IRFs) is violated often enough to be worth checking. Using nonparametric item response theory (IRT) estimation methods with the posterior predictive model checking method can obtain significance probabilities of fit statistics in a Bayesian framework by accounting for the uncertainty of the parameter estimation and can indicate the location and magnitude of misfit for an item. The purpose of this study is to check the performance of the Bayesian nonparametric method to assess the IRF fit of parametric IRT models for mixed-format tests and compare it with the existing bootstrapping nonparametric method under various conditions. The simulation study results show that the Bayesian nonparametric method can detect misfit items with higher power and lower type I error rates when the sample size is large and with lower type I error rates compared with the bootstrapping method for the conditions with nonmonotonic items. In the real-data study, several dichotomous and polytomous misfit items were identified and the location and magnitude of misfit were indicated.
Preserving Organizational Trust During Disruption
Authors: Gustafsson Stefanie , Gillespie Nicole , Searle Rosalind , Hope Hailey Veronica , Dietz Graham
Published: March 2020

How is organizational trust preserved during times of disruption? We address this question, building on the concept of active trust which views trust as an ongoing accomplishment constituted by reflexive actors. Drawing on a multi-case study of four organizations that experienced major disruption in response to the global financial crisis of 2009, we contribute to trust theory in three ways. First, we extend beyond the current focus on trust building and repair by developing conceptual understanding of trust preservation as a distinct phenomenon. Second, we develop a theoretical model that explains how organizational actors accomplish the preservation of employees’ trust in their organization. We identify three trust preservation practices used in the successful case organizations – cognitive bridging, emotional embodying and inclusive enacting – and show that organizational members’ understanding of the established foundations of trust in the organization, and their ability to mobilize these, are critical to the preservation of trust. Third, we position trust preservation as a manifestation and extension of active trust, and show that for trust to be preserved in disruptive contexts, both familiarization and transformation of existing trust practices are required.
‘Are they out to get us?’ Power and the ‘recognition’ of the subject through a ‘lean’ work regime
Authors: Mackenzie Ewan , McGovern Tom , Small Adrian , Hicks Chris , Scurry Tracy
Published: March 2020

Critical studies of ‘lean’ work regimes have tended to focus on the factory shop floor or public and healthcare sectors, despite its recent revival and wider deployment in neoliberal service economies. This paper investigates the politics of the workplace in a United Kingdom automotive dealership group subject to an intervention inspired by lean methods. We develop Foucauldian studies of governmentality by addressing lean as a technology of power deployed to act on the conduct of workers, examining how they debunk, distance themselves from and enact its imperatives. Our findings support critiques of lean work regimes that raise concerns about work intensification and poor worker health. Discourses of professional autonomy allow workers to distance themselves from lean prescriptions, yet they are reaffirmed in their actions. More significantly, we illustrate the exercise of a more encompassing form of power, showing how lean harnesses the inherently exploitable desire for recognition among hitherto marginalised workers, and its role as a form of ‘human capital’. The paper contributes to critical studies of lean by illustrating its subtle, deleterious and persistent effects within the analytical frame of neoliberal governmentality. We also demonstrate how studies of governmentality can be advanced through the analysis of contested social relations on the ground, highlighting the ethico-political potential of Foucauldian work.
A National Survey on Mental Health Professional Development in Juvenile Justice Facilities: Implications for Youth Reentry
Authors: Gagnon Joseph Calvin , Swank Jacqueline M.
Published: March 2020

A national study of clinical directors examined professional development (PD) focused on mental health provided to professionals in juvenile justice facilities for adjudicated youth. A total of 85 clinical directors responded to a mail survey (45% return rate). The survey questions related to (a) topics of staff training and the basis for choosing topics, (b) which professionals participated in each PD topic, (c) training format and frequency of PD, (d) recommended attributes of PD, (e) methods of evaluating PD, and (f) adequacy of PD and how can it be improved. For each topic, PD was typically provided once per year and face to face, rather than online. PD participation rates were commonly in the 30% and 40% ranges for professionals other than clinical directors and counselors, with teachers, correctional officers, administrators, and teaching assistants receiving PD the least. Rarely did PD include recommended attributes of PD, and it was commonly viewed as ineffective. Implications for research and practice related to PD and its relationship to youth reentry from juvenile justice facilities are discussed.
Using loss- and gain-of-function approaches to target amygdala-projecting serotonergic neurons in the dorsal raphe nucleus that enhance anxiety-related and conditioned fear behaviors
Authors: Bernabe Cristian S , Caliman Izabela F , Truitt William A , Molosh Andrei I , Lowry Christopher A , Hay-Schmidt Anders , Shekhar Anantha , Johnson Philip L
Published: March 2020

Background:

The central serotonergic system originating from the dorsal raphe nucleus (DR) plays a critical role in anxiety and trauma-related disorders such as posttraumatic stress disorder. Although many studies have investigated the role of serotonin (5-HT) within pro-fear brain regions such as the amygdala, the majority of these studies have utilized non-selective pharmacological approaches or poorly understood lesioning techniques which limit their interpretation.

Aim:

Here we investigated the role of amygdala-projecting 5-HT neurons in the DR in innate anxiety and conditioned fear behaviors.

Methods:

To achieve this goal, we utilized (1) selective lesion of 5-HT neurons projecting to the amygdala with saporin toxin conjugated to anti-serotonin transporter (SERT) injected into the amygdala, and (2) optogenetic excitation of amygdala-projecting DR cell bodies with a combination of a retrogradely transported canine adenovirus-expressing Cre-recombinase injected into the amygdala and a Cre-dependent-channelrhodopsin injected into the DR.

Results:

While saporin treatment lesioned both local amygdalar 5-HT fibers and neurons in the DR as well as reduced conditioned fear behavior, optical activation of amygdala-projecting DR neurons enhanced anxious behavior and conditioned fear response.

Conclusion:

Collectively, these studies support the hypothesis that amygdala-projecting 5-HT neurons in the DR represent an anxiety and fear-on network.
Hyperpolarized 13C MRI: A novel approach for probing cerebral metabolism in health and neurological disease
Authors: Grist James T , Miller Jack J , Zaccagna Fulvio , McLean Mary A , Riemer Frank , Matys Tomasz , Tyler Damian J , Laustsen Christoffer , Coles Alasdair J , Gallagher Ferdia A
Published: March 2020

Cerebral metabolism is tightly regulated and fundamental for healthy neurological function. There is increasing evidence that alterations in this metabolism may be a precursor and early biomarker of later stage disease processes. Proton magnetic resonance spectroscopy (1H-MRS) is a powerful tool to non-invasively assess tissue metabolites and has many applications for studying the normal and diseased brain. However, the technique has limitations including low spatial and temporal resolution, difficulties in discriminating overlapping peaks, and challenges in assessing metabolic flux rather than steady-state concentrations. Hyperpolarized carbon-13 magnetic resonance imaging is an emerging clinical technique that may overcome some of these spatial and temporal limitations, providing novel insights into neurometabolism in both health and in pathological processes such as glioma, stroke and multiple sclerosis. This review will explore the growing body of pre-clinical data that demonstrates a potential role for the technique in assessing metabolism in the central nervous system. There are now a number of clinical studies being undertaken in this area and this review will present the emerging clinical data as well as the potential future applications of hyperpolarized 13C magnetic resonance imaging in the brain, in both clinical and pre-clinical studies.
CCR2 deficiency in monocytes impairs angiogenesis and functional recovery after ischemic stroke in mice
Authors: Pedragosa Jordi , Miró-Mur Francesc , Otxoa-de-Amezaga Amaia , Justicia Carles , Ruíz-Jaén Francisca , Ponsaerts Peter , Pasparakis Manolis , Planas Anna M
Published: March 2020

Inflammatory Ly6ChiCCR2+ monocytes infiltrate the brain after stroke but their functions are not entirely clear. We report that CCR2+ monocytes and CCR2+ lymphocytes infiltrate the brain after permanent ischemia. To underscore the role of CCR2+ monocytes, we generated mice with selective CCR2 deletion in monocytes. One day post-ischemia, these mice showed less infiltrating monocytes and reduced expression of pro-inflammatory cytokines, markers of alternatively macrophage activation, and angiogenesis. Accordingly, Ly6Chi monocytes sorted from the brain of wild type mice 24 h post-ischemia expressed pro-inflammatory genes, M2 genes, and pro-angiogenic genes. Flow cytometry showed heterogeneous phenotypes within the infiltrating Ly6ChiCCR2+ monocytes, including a subgroup of Arginase-1+ cells. Mice with CCR2-deficient monocytes displayed a delayed inflammatory rebound 15 days post-ischemia that was not found in wild type mice. Furthermore, they showed reduced angiogenesis and worse behavioral performance. Administration of CCR2+/+ bone-marrow monocytes to mice with CCR2-deficient monocytes did not improve the behavioral performance suggesting that immature bone-marrow monocytes lack pro-reparative functions. The results show that CCR2+ monocytes contribute to acute post-ischemic inflammation and participate in functional recovery. The study unravels heterogeneity in the population of CCR2+ monocytes infiltrating the ischemic brain and suggests that pro-reparative monocyte subsets promote functional recovery after ischemic stroke.
Excitatory/inhibitory neuronal metabolic balance in mouse hippocampus upon infusion of [U-13C6]glucose
Authors: Cherix Antoine , Donati Guillaume , Lizarbe Blanca , Lanz Bernard , Poitry-Yamate Carole , Lei Hongxia , Gruetter Rolf
Published: March 2020

Hippocampus plays a critical role in linking brain energetics and behavior typically associated to stress exposure. In this study, we aimed to simultaneously assess excitatory and inhibitory neuronal metabolism in mouse hippocampus in vivo by applying 18FDG-PET and indirect 13C magnetic resonance spectroscopy (1H-[13C]-MRS) at 14.1 T upon infusion of uniformly 13C-labeled glucose ([U-13C6]Glc). Improving the spectral fitting by taking into account variable decoupling efficiencies of [U-13C6]Glc and refining the compartmentalized model by including two γ-aminobutyric acid (GABA) pools permit us to evaluate the relative contributions of glutamatergic and GABAergic metabolism to total hippocampal neuroenergetics. We report that GABAergic activity accounts for ∼13% of total neurotransmission (VNT) and ∼27% of total neuronal TCA cycle (VTCA) in mouse hippocampus suggesting a higher VTCA/VNT ratio for inhibitory neurons compared to excitatory neurons. Finally, our results provide new strategies and tools for bringing forward the developments and applications of 13C-MRS in specific brain regions of small animals.
UK consensus on pre-clinical vascular cognitive impairment functional outcomes assessment: Questionnaire and workshop proceedings
Authors: McFall Aisling , Hietamies Tuuli M , Bernard Ashton , Aimable Margaux , Allan Stuart M , Bath Philip M , Brezzo Gaia , Carare Roxana O , Carswell Hilary V , Clarkson Andrew N , Currie Gillian , Farr Tracy D , Fowler Jill H , Good Mark , Hainsworth Atticus H , Hall Catherine , Horsburgh Karen , Kalaria Rajesh , Kehoe Patrick , Lawrence Catherine , Macleod Malcolm , McColl Barry W , McNeilly Alison , Miller Alyson A , Miners Scott , Mok Vincent , O’Sullivan Michael , Platt Bettina , Sena Emily S , Sharp Matthew , Strangward Patrick , Szymkowiak Stefan , Touyz Rhian M , Trueman Rebecca C , White Claire , McCabe Chris , Work Lorraine M , Quinn Terence J
Published: March 2020

Assessment of outcome in preclinical studies of vascular cognitive impairment (VCI) is heterogenous. Through an ARUK Scottish Network supported questionnaire and workshop (mostly UK-based researchers), we aimed to determine underlying variability and what could be implemented to overcome identified challenges. Twelve UK VCI research centres were identified and invited to complete a questionnaire and attend a one-day workshop. Questionnaire responses demonstrated agreement that outcome assessments in VCI preclinical research vary by group and even those common across groups, may be performed differently. From the workshop, six themes were discussed: issues with preclinical models, reasons for choosing functional assessments, issues in interpretation of functional assessments, describing and reporting functional outcome assessments, sharing resources and expertise, and standardization of outcomes. Eight consensus points emerged demonstrating broadly that the chosen assessment should reflect the deficit being measured, and therefore that one assessment does not suit all models; guidance/standardisation on recording VCI outcome reporting is needed and that uniformity would be aided by a platform to share expertise, material, protocols and procedures thus reducing heterogeneity and so increasing potential for collaboration, comparison and replication. As a result of the workshop, UK wide consensus statements were agreed and future priorities for preclinical research identified.
Application of Mendelian Randomization to Investigate the Association of Body Mass Index with Health Care Costs
Authors: Kurz Christoph F. , Laxy Michael
Published: March 2020

Causal effect estimates for the association of obesity with health care costs can be biased by reversed causation and omitted variables. In this study, we use genetic variants as instrumental variables to overcome these limitations, a method that is often called Mendelian randomization (MR). We describe the assumptions, available methods, and potential pitfalls of using genetic information and how to address them. We estimate the effect of body mass index (BMI) on total health care costs using data from a German observational study and from published large-scale data. In a meta-analysis of several MR approaches, we find that models using genetic instruments identify additional annual costs of €280 for a 1-unit increase in BMI. This is more than 3 times higher than estimates from linear regression without instrumental variables (€75). We found little evidence of a nonlinear relationship between BMI and health care costs. Our results suggest that the use of genetic instruments can be a powerful tool for estimating causal effects in health economic evaluation that might be superior to other types of instruments where there is a strong association with a modifiable risk factor.
Development of a total hip replacement phantom for the assessment of CT-image quality
Authors: Muellensiefen Mara , Tins Bernhard , Kuiper Jan-Herman , Weber Marc-André , Krakowski-Roosen Holger
Published: March 2020

Background

The quality of computed tomography (CT) imaging is important when used to judge the success of joint replacement surgery. Metal artefacts are a known source of error, typically compensated by noise reduction software.

Purpose

To develop a transportable and stable system for the assessment of image quality of bone lesions around orthopedic implants.

Material and Methods

The design and manufacture of a bone-implant-phantom is described, which is based on a calf acetabulum with surrounding pelvic bone structures. Bone lesions of several sizes were created in the acetabulum before implanting the cup of an uncemented hip prosthesis, which was fixed with a stainless-steel bone screw. Plastic strips were placed on a cobalt–chromium stemmed femoral component, simulating typical bone lesions around loosening or infected prostheses, before embedding the stem in material similar to bone and shaped like a femur. The head of the femoral component was then placed in the acetabular cup and CT scans were produced.

Results

It was possible to construct a durable CT hip phantom for quality assurance work. The usability of different materials and the choices made for the phantom are discussed.

Conclusion

It is possible to construct a durable joint implant phantom for quality assurance and scanner hardware and software assessment with limited resources. The phantom was successfully used in the assessment of the hardware and software performance of different CT scanners.
Measurement of creep deformation of ex-service 12% Cr steel using digital image correlation
Authors: van Rooyen Melody , Becker Thorsten Hermann , Westraadt Johan Ewald , Marx Genevéve
Published: March 2020

The effective operation of ageing coal-fired power plants requires routine damage assessment of critical component materials throughout their service history. Traditional post-exposure mechanical testing typically requires large amounts of material for each testing condition. This study introduces an accelerated (high stress and temperature) creep testing technique that employs digital image correlation for strain measurement over a non-uniform temperature field generated by a thermomechanical tester. When applied to different ex-service (exposed to service conditions within a power plant) 12% Cr piping steels, multiple accelerated creep curves at temperatures ranging from 550°C to 600°C are measured from a single specimen for each material condition. Higher creep damage in the steel due to longer service exposure and higher void densities is revealed by shorter rupture times, faster creep rates and tertiary-dominated creep curves when compared to the lower creep damage state. Microstructural study via quantitative electron microscopy confirms the dislocation creep-driven growth of subgrains in the specimen gauge regions relative to the grips. Larger subgrains and a weakening of precipitate distributions for the high damage material were also noted. Digital image correlation–measured strains are in good agreement with traditional techniques of creep testing with standard extensometry. On a comparative basis, the technique is shown to be a plausible form of damage assessment of 12% Cr piping steels with varying levels of service exposure and serve as a suitable mechanical complement to the traditional void replica methodology.
The prevalence of hypnic headache in Iceland
Authors: Eliasson Jon H , Scher Ann I , Buse Dawn C , Tietjen Gretchen , Lipton Richard B , Launer Lenore J , Valdimarsdottir Unnur A , Gudmundsson Larus S
Published: March 2020

Objective

To determine the prevalence of hypnic headache.

Background

The exact prevalence of hypnic headache is unknown since there are no published population-based prevalence studies.

Methods

This study was a pilot for the SAGA cohort study, a population-based study on life stressors and various indices of health. Of 1398 invited adults, 921 (66%) participated; 402 men (average age 45.6 years, SD 13.2) and 519 women (52.6 years, SD 11.1). Subjects answered a headache questionnaire including a screening question for hypnic headache. “Do you have a headache that occurs only during sleep and causes wakening?”. Diagnosis of hypnic headache was made by clinical interview using ICHD-3 criteria.

Results

Among 921 participants, six screened positive for hypnic headache, of those two 0.22% (95% CI 0.06–0.79%) had probable hypnic headache and none had definite hypnic headache.

Conclusion

Confirming that hypnic headache is rare, these data suggest a 0.22% prevalence of probable hypnic headache.
Medication overuse headache in 787 patients admitted for inpatient treatment over a period of 32 years
Authors: Salhofer-Polanyi Sabine , Zebenholzer Karin , Berndl Thomas , Kastrati Kastriot , Raab Sandra , Schweitzer Patricia , Stria Tim , Topic Pavao , Wöber Christian
Published: March 2020

Background

Definitions of medication overuse headache have changed over time.

Objective

To evaluate the clinical characteristics of medication overuse headache patients admitted for inpatient withdrawal therapy over a period of 32 years.

Methods

We included all patients with medication overuse headache treated from 1 January 1984 to 31 December 2015. We obtained all data from the medical reports and defined three periods, P1 (1984–1993), P2 (1994–2003), and P3 (2004–2015). The p-value adjusted for multiple comparisons was set to 0.005.

Results

Within 32 years, a total of 787 patients accounted for 904 admissions for MOH. From P1 to P3, the proportion of patients with preexisting migraine increased from 44.3% to 53.3% (chi2 = 9.0, p = 0.01) and that with preexisting tension-type headache decreased from 47.9% to 34.6% (chi2 = 9.3, p < 0.01). The median time since onset of headache and medication overuse headache decreased from 20 to 15 years ( p < 0.001) and from 3 to 2 years ( p < 0.001). The median cumulative number of single doses decreased from 120 to 90 per month ( p = 0.002). Overuse of triptans, non-opioid analgesics, and opioids increased, whereas overuse of ergotamines decreased over time ( p < 0.001 for all tests). The use of prophylactic medication before admission increased from 8.3% to 29.9% (chi2 = 89.5, p < 0.001).

Conclusion

This retrospective study in a large number of patients with medication overuse headache admitted for inpatient withdrawal therapy over a period of 32 years shows a trend towards changes in the preexisting headache type, a decrease in the time since onset of headache and medication overuse headache, a decrease in the number of drug doses used per month, changes in the type of drugs overused, and an increase in, but still low rate, of prophylactic medication prior to admission.
Smooth-Switching Control-Based Cooperative Adaptive Cruise Control by Considering Dynamic Information Flow Topology
Authors: Zhou Anye , Gong Siyuan , Wang Chaojie , Peeta Srinivas
Published: March 2020

Vehicle-to-vehicle communications can be unreliable because of interference and information congestion, which leads to the dynamic information flow topology (IFT) in a platoon of connected and autonomous vehicles. Some existing studies adaptively switch the controller of cooperative adaptive cruise control (CACC) to optimize string stability when IFT varies. However, the difference of transient response between controllers can induce uncomfortable jerks at switching instances, significantly affecting riding comfort and jeopardizing vehicle powertrain. To improve riding comfort while maintaining string stability, the authors introduce a smooth-switching control-based CACC scheme with IFT optimization (CACC-SOIFT) by implementing a bi-layer optimization model and a Kalman predictor. The first optimization layer balances the probability of communication failure and control performance optimally, generating a robust IFT to reduce controller switching. The second optimization layer adjusts the controller parameters to minimize tracking error and the undesired jerk. Further, a Kalman predictor is applied to predict vehicle acceleration if communication failures occur. It is also used to estimate the states of preceding vehicles to suppress the measurement noise and the acceleration disturbance. The effectiveness of the proposed CACC-SOIFT is validated through numerical experiments based on NGSIM field data. Results indicate that the CACC-SOIFT framework can guarantee string stability and riding comfort in the environment of dynamic IFT.
Application Tool for Two-Variable Cost Allocation for Small Urban, Rural, and Tribal Transit Agencies
Authors: Hansen Todd , Walk Michael , Tan Shuman
Published: March 2020

The paper presents the development and methodology of application tools for use in transit agency cost allocation. Researchers worked with the National Rural Transit Assistance Program to develop the Two-Variable Cost Allocation Calculator applications as a resource for small transit agencies. Reports and guidance on cost allocation were reviewed to identify key considerations for application design, was also informed by previous experience with transit agencies for examples of cost and data considerations with respect to agency size, travel mode, and type of service. The applications use a two-variable methodology of vehicle hours and miles to allocate variable costs for each service, then allocate fixed costs according to the proportions of variable costs. The applications also provide a process to sub-allocate costs for shared-ride demand responsive services using passenger hours and miles data. A common set of data requirements needed to run the applications into groups of service, financial, and operational data was developed. The applications use standard definitions of data elements from the National Transit Database and Federal Transit Administration to streamline the data needed in the application with existing reporting requirements. The applications are designed for ease of use by small transit agencies with limited staff and different levels of training in data collection or financial management. The applications allow small transit agencies to specify aspects of service information to be used in cost allocation while relying on the applications to sort expenses into appropriate cost function categories, calculate costs by service type, and generate summary reports and performance metrics.
Before-and-After Empirical Bayes Evaluation of Citywide Installation of Driver Feedback Signs
Authors: Wu Mingjian , El-Basyouny Karim , Kwon Tae J.
Published: March 2020

Speeding is a leading factor that contributes to approximately one-third of all fatal collisions. Over the past decades, various passive/active countermeasures have been adopted to improve drivers’ compliance to posted speed limits to improve traffic safety. The driver feedback sign (DFS) is considered a low-cost innovative intervention that is being widely used, in growing numbers, in urban cities to provide positive guidance for motorists. Despite their documented effectiveness in reducing speeds, limited literature exists on their impact on reducing collisions. This study addresses this gap by designing a before-and-after study using the empirical Bayes method for a large sample of urban road segments. Safety performance functions and yearly calibration factors are developed to quantify the sole effectiveness of DFS using large-scale spatial data and a set of reference road segments within the city of Edmonton, Alberta, Canada. Likewise, the study followed a detailed economic analysis based on three collision-costing criteria to investigate if DFS was indeed a cost-effective intervention. The results showed significant collision reductions that ranged from 32.5% to 44.9%, with the highest reductions observed for severe speed-related collisions. The results further attested that the benefit–cost ratios, combining severe and property-damage-only collisions, ranged from 8.2 to 20.2 indicating that DFS can be an extremely economical countermeasure. The findings from this study can provide transportation agencies in need of implementing cost-efficient countermeasures with a tool they need to design a long-term strategic deployment plan to ensure the safety of traveling public.
The legacy of reification: Gillian Rose and the value-form theory challenge to Georg Lukács
Authors: Lazarus Michael
Published: March 2020

This article examines the relationship between Marx’s Capital, Georg Lukács and Critical Theory through the prism of value-form theory. Marx’s theorisation of value understands commodities as expressions of the historical form of social relations defined by capital. Products of human labour become values in capitalist production, defined by the abstract quality of undifferentiated quantities of labour-power, exchangeable through the universal character of the market. The social form of this process, Marx identifies as processing a fetish quality, where humans take on the thing-like character of commodities. The impact of this theorisation on Critical Theory has been considerable, beginning with Lukács’ concept of reification. In Part I, I examine the challenge to Lukács’ interpretation of Marx’s Capital made by Gillian Rose. She draws attention to a misidentification of reification in Marx, suggesting a strong conceptual distinction between commodity-fetishism and reification. In their conceptual flattening, Rose contends that Lukács and Critical Theory generalised Marx’s value-form theory, losing its speculative character. I argue that despite Rose’s suggestion remaining unfulfilled, she helps illuminate important tensions between Marx’s value theory and Critical Theory. This comparison allows in Part II for the beginning level of a speculative approach to Marx’s Capital to be advanced.
Health services restructuring in Alberta and the 2009 pandemic influenza—An untimely concurrence
Authors: Musto Richard , MacDonald Judy , Ulrich Anne , Fonseca Kevin
Published: March 2020

In the last 12 years, every Canadian province and territory has undertaken significant health services restructuring, with the pace of change accelerating recently. When the H1N1 Pandemic Influenza (PI) hit Alberta in the spring of 2009, the province had just begun a restructuring of health services of a scale unprecedented in Canada. The new province-wide entity, Alberta Health Services (AHS), was faced with mounting an effective response to a global communicable disease outbreak during a time of great organizational flux. In this retrospective, the authors reflect on challenges and opportunities presented during the AHS PI response related to the coordination of public health, laboratory services, emergency and disaster management, communications, and health services delivery. Lessons learned are shared that may be helpful to other provinces and territories as they continue to evolve their systems, so that they may be better prepared to respond to an untimely event such as a pandemic.
One-pot synthesis of cellulose-based nonwoven web incorporated with chitosan for hemostat applications
Authors: Hemamalini T , Vikash N , Brindha P , Abinaya M , Giri Dev VR
Published: March 2020

Water-soluble chitosan and wood pulp fiber–based nonwovens were produced using wet-laying technology, and their properties were investigated for the potential application for severe hemorrhage. The pores of the wood pulp nonwovens were completely covered as the concentration of chitosan was increased. A phosphate buffer solution uptake of 997% was attained in the nonwoven loaded with chitosan concentration of 1.5 w/v%. The deposition of blood cells was found to increase with an increase in the water-soluble chitosan concentration. The blood-clotting time was found to be 170 s, making the developed nonwoven to promote blood-clotting mechanism by creating mechanical barrier to reduce the blood loss.
Clinical Applications of Ultrasonography in Neurocritically Ill Patients
Authors: Caballero-Lozada Andrés Fabricio , Nanwani Kapil Laxman , Pavón Favio , Zorrilla-Vaca Andrés , Zorrilla-Vaca Carolina
Published: March 2020

Ultrasonography is part of the multimodal monitoring of the neurocritical patient. Through transcranial color Doppler ultrasound, carotid-color Doppler ultrasound, and ocular ultrasound it is possible to diagnose and monitor a multitude of pathological conditions, such as cerebrovascular events, vasospasm, Terson syndrome, carotid atheromatosis, and brain death. Furthermore, these techniques enable the monitoring of the intracranial pressure, the cerebral perfusion pressure, and the midline deviation, which allows us to understand the patient’s neurocritical pathology at their bedside, in a noninvasive way. Although none of these tools have yet been shown to improve patient prognosis, the dissemination of knowledge and management of neurovascular ultrasonography could significantly improve the comprehensive management of neurocritical patients.
Determination of charge carrier transport properties of gellan gum–lithium triflate solid polymer electrolyte from vibrational spectroscopy
Authors: Noor IM
Published: March 2020

Mobility and number density of charge carriers are important parameters that influence the electrolyte conductivity. Therefore, knowing these parameters quantitatively is of great significance. In this work, solid polymer electrolytes have been prepared by solution casting technique using gellan gum complexes with lithium triflate (LiTf). The conductivity of the electrolyte increases from 3.35 × 10−8 S cm−1 (electrolyte with 10 wt% LiTf) to 5.38 × 10−4 S cm−1 (electrolyte with 40 wt% LiTf). The increase in conductivity was attributed to the increase in mobility and number density of charge carriers in the electrolyte from 6.63 × 10−9 cm2 V−1 s−1 to 1.25 × 10−6 cm2 V−1 s−1 and from 4.00 × 1020 cm−3 to 2.68 × 1021 cm−3, respectively. The electrolyte conductivity is seen to decrease as LiTf salts were added more than 40 wt% concentration due to the decrease of charge carrier mobility to 8.58 × 10−7 cm2 V−1 s−1. The variation of conductivity obtained in this work is dominantly influenced by the mobility of charge carriers in the electrolyte as proven from the Fourier transform infrared approach.
Polyvinylpyrrolidone with ammonium iodide and 1-hexyl-3-methylimidazolium iodide ionic liquid-doped solid polymer electrolyte for efficient dye sensitized solar cell
Authors: Singh Diksha , Dhapola Pawan Singh , Singh Vijay , Singh Pramod K
Published: March 2020

Polymer electrolytes were prepared by doping polyvinylpyrrolidone and ammonium iodide ion with an ionic liquid (IL) 1-hexyl-3-methylimidazolium iodide. Polymer electrolytes were prepared by solution cast technique. Ionic conductivity was improved by the addition of IL which is studied using complex impedance spectroscopy by evaluating ionic conductivity. Using maximum electrical conductivity film, laboratory-scale dye-sensitized solar cell has been fabricated which shows stable performance.
Influence of high and low dielectric constant plasticizers on the ion transport properties of PEO: NH4HF2 polymer electrolytes
Authors: Sharma Jitender Paul , Singh Vijay
Published: March 2020

Different composition ratio of polymer electrolytes based on poly(ethylene oxide) (PEO) as host polymer, ammonium bifluoride (NH4HF2) as salt, and propylene carbonate (PC), dimethyl acetamide (DMA), dimethyl chloride (DMC), and diethyl carbonate (DEC) as plasticizers has been prepared by solution casting technique. The influence of high dielectric constant plasticizers (PC and DMA) and low dielectric constant plasticizers (DMC and DEC) on the ion transport properties of PEO-NH4HF2 polymer electrolytes has been studied. The increase in ionic conductivity of polymer electrolytes containing PC and DMA is observed to be more as compared to those electrolytes containing DMC and DEC, which is due to an increase in both the amorphous phase and dielectric constant of PEO. X-ray diffraction study reveals the amorphous nature in case of plasticized polymer electrolyte. In the Fourier transform infrared study, the changes and shifting of the different characteristic peaks confirm the polymer–salt complex formation and the dissociation of ion aggregates present at higher concentration of salt with the addition of PC. Maximum ionic conductivity of 1.40 × 10−4 S cm−1 at room temperature has observed in case of plasticized polymer electrolytes containing optimum concentration of PC so that mechanical stability and flexibility be maintained. The variation of linewidth with temperature has also been studied by 1H and 19F nuclear magnetic resonance (NMR), which confirms that both cations and anions are mobile in these polymer electrolytes. Line narrowing associated with the glass transition temperature ( T g; low mobility region) and melting temperature ( T m; high mobility region) of PEO has also been observed for plasticized polymer electrolytes containing PC having optimum conductivity value. Conductivity versus temperature variation study reveals curved nature of plot in case of plasticized polymer electrolytes containing high dielectric constant plasticizers, which is significant for their amorphous nature. Smooth morphology observed in case of plasticized polymer electrolytes having optimum conductivity value is essential key factor for polymer electrolytes to be suitable for practical applications.
Electrochemical double-layer supercapacitor using poly(methyl methacrylate) solid polymer electrolyte
Authors: Zakariya’u Ibrahim , Gultekin Burak , Singh Vijay , Singh Pramod K
Published: March 2020

The prime objective of the present article is to develop an efficient supercapacitor based on polymer electrolyte doped with salt. Solution cast technique was adopted to develop a solid polymer electrolyte of polymer poly(methyl methacrylate) (PMMA) as host polymer and salt potassium hydroxide (KOH) as a dopant. Incorporation of salt increases the amorphicity and assisted in conductivity enhancement. Moreover, doping of salt increases the overall conductivity of polymer electrolyte film. Electrochemical impedance spectroscopy reveals the enhancement in conductivity (four orders of magnitude) by salt doping. Fourier transform infrared shows the complexation and composite nature of films. Polarized optical microscopy shows the reduction in crystallinity, which is further confirmed by Differential scanning calorimetry. Fabricated electrochemical double-layer supercapacitor using maximum conducting polymer—salt electrolyte and symmetric carbon nanotubes electrodes shows specific capacitance of 21.86 F g−1.
Ion transport studies in PVA:NH4CH3COO gel polymer electrolytes
Authors: Singh CP , Shukla PK , Agrawal SL
Published: March 2020

Ion conducting gel polymer electrolytes (GPEs) are being intensively studied for their potential applications in various electrochemical devices. The poly(vinyl alcohol)-based GPE films containing ammonium acetate (NH4CH3COO) salt have been studied for various concentrations of salt. The gel electrolyte films (GPEs) have been prepared using solution casting technique. Structural characterization carried out using X-ray diffraction reveals an increase in the amorphous nature of the samples on increasing salt concentration up to 70 wt%. The complexation of polymer and salt has been studied by Fourier-transform infrared analysis. Ionic conductivity of the GPEs has been found to increase with salt concentration and reaches an optimum for an intermediate concentration. The room temperature conductivity isotherm exhibits a maximum in conductivity of 2.64 × 10−4 Scm−1 for 65 wt% salt concentration. The temperature dependence of ionic conductivity exhibits a combination of Arrhenius and Vogel–Tamman–Fulcher behavior. Ion transport in the electrolyte system has been explored using dielectric response of the material and the observed variation in conductivity is suitably correlated to the change in charge carrier concentration and mobility of charge carriers.
Digital retrofit: A first step toward the adoption of Industry 4.0 to the manufacturing systems of small and medium-sized enterprises
Authors: García José I , Cano Ruth E , Contreras Juan D
Published: March 2020

In recent years, Industry 4.0 has gained relevance in the manufacturing sector. On one hand, it is expected that this new paradigm will affect the entire value chain and increase the capabilities of the manufacturing system as a whole, in terms of interoperability and communication throughout factories and beyond. On the other hand, considering that small and medium-sized enterprises represent one of the main forces in economic development and employment generation, focus is shifting toward said manufacturing paradigm in order to ensure competitiveness in the market in the nearby future. However, economic factors could stand in the way of this migration. Thus, digital retrofit is seen as a possibility for the integration of Industry 4.0, paving the way for unappealing technologies to large investment opportunities. In this article, a thorough literary review is performed regarding the formal implementation of Industry 4.0 applications. The result is the Asset Administration Shell model. Afterward, a methodology is proposed for the design and implementation of the Asset Administration Shell, leading to a digital retrofit approach for manufacturing resources. Finally, the methodology is applied in a turning station, thereby validating an increase in the communication and interoperability of the station, which can be used to add overall value to the manufacturing system.