bluuebunny/crossref_metadata_2025 huggingface dataset:
The most primitive mesosiderite Northwest Africa 1878, subgroup 0
Authors: Kimura M. , Sugiura N. , Yamaguchi A. , Ichimura K.
Published: April 2020

All mesosiderites previously reported were subjected to thermal metamorphism and/or partial melting on the parent body. Therefore, their primordial features have been mostly lost. Here, we report detailed petrological and mineralogical features on a mesosiderite, Northwest Africa (NWA) 1878. This meteorite comprises silicate lithology and aggregates of small spheroidal Fe‐Ni metal grains. Silicate lithology typically shows igneous texture without recrystallization features, and mainly consists of low‐Ca pyroxene and plagioclase. Pyroxenes often show normal zoning. Exsolution lamella of augite is rarely noticed and very thin in width, compared with other mesosiderites. A few magnesian olivine grains are encountered without typical corona texture around them. They are not equilibrated with pyroxene on a large scale. Plagioclase shows a wide compositional range. These results show that NWA 1878 hardly experienced thermal metamorphism, distinguished from mesosiderites of subgroups 1–4. Therefore, we propose that this is classified as subgroup 0 mesosiderite. Nevertheless, NWA 1878 was locally subjected to secondary reactions, such as weak reduction of pyroxene and Fe‐Mg diffusion between olivine and pyroxene, on the parent body.
The impact of age on patient tolerance of mycophenolate following kidney transplantation
Authors: Rennie Trijntje J. W. , Petrie Michaela , Metcalfe Wendy , Walbaum David , Joss Nicola , Barton Ellen , Marson Lorna , Clancy Marc J. , Henderson Lorna , Traynor Jamie P. , Geddes Colin G. , Phelan Paul J.
Published: April 2020

Background

In Scotland, standard maintenance immunosuppression following kidney transplantation consists of mycophenolate (MPA), tacrolimus and prednisolone irrespective of recipient age. We analyzed the tolerability of this immunosuppression regimen and the association with transplant outcomes.

Methods

A national, multicentre retrospective analysis of patients transplanted in 2015 and 2016, comparing graft function, acute rejection, significant infection rates and immunosuppression dosing between patients aged 18 and 59 years (Group 1) and ≥60 years (Group 2).

Results

Of the 490 patients, 26% were aged ≥60 years. Acute rejection (AR) rates at 1 year were 15% and 11% in Groups 1 and 2, respectively. Full‐dose MPA was poorly tolerated with 53% in Group 1 and 77% in Group 2 requiring dose reduction or cessation. Female gender and age ≥60 years were independent predictors for MPA dose changes. One year following MPA dose reduction, AR risk was low (5%) in Group 2, however, those remaining on full dose MPA had a 79% increased rate of serious infections.

Conclusion

The majority of renal transplant recipients aged ≥60 fail to tolerate full‐dose MPA. In this group, MPA dose reduction is associated with low rejection rates, but full‐dose MPA is associated with high infection rates. We suggest that a tailored approach to immunosuppression in elderly recipients incorporating lower doses of MPA may be appropriate.
Urinary exosomes: Potential biomarkers for diabetic nephropathy
Authors: Sinha Nisha , Kumar Vivek , Puri Veena , Nada Ritambhra , Rastogi Ashu , Jha Vivekanand , Puri Sanjeev
Published: April 2020

Diabetic nephropathy is the most common diabetic complication culminating often into end‐stage renal disease. Classically, it is defined by the presence of albuminuria which has limited ability to be detected at early stages but deterioration in kidney function generally precedes albuminuria. This necessitates the development of newer diagnostic assays for diabetic nephropathy to determine the progression of the disease. Kidney associated diseases with non‐albuminuria further complicates a timely diagnosis and thus demands an early biomarker. Urinary exosomes, the nanovesicular entities are released by every epithelial cells of the nephron. Their protein or molecular cargo varies in the diseased state which may provide the pathophysiology of the kidney associated diseases. This drives them to be exploited as non‐invasive biomarker. This review thus integrates the recent findings on the significance of the urinary exosomes as diagnostic biomarker in kidney‐associated diseases, primarily in diabetic nephropathy.
Effects of landscapes and range expansion on population structure and local adaptation
Authors: Zhao Wei , Sun Yan‐Qiang , Pan Jin , Sullivan Alexis R. , Arnold Michael L. , Mao Jian‐Feng , Wang Xiao‐Ru
Published: April 2020

Understanding the origin and distribution of genetic diversity across landscapes is critical for predicting the future of organisms in changing climates. This study investigated how adaptive and demographic forces have shaped diversity and population structure in Pinus densata, a keystone species on Qinghai‐Tibetan Plateau (QTP).

We examined the distribution of genomic diversity across the range of P. densata using exome capture sequencing. We applied spatially explicit tests to dissect the impacts of allele surfing, geographic isolation and environmental gradients on population differentiation and forecasted how this genetic legacy may limit the persistence of P. densata in future climates.

We found that allele surfing from range expansion could explain the distribution of 39% of the c. 48 000 genotyped single nucleotide polymorphisms (SNPs). Uncorrected, these allele frequency clines severely confounded inferences of selection. After controlling for demographic processes, isolation‐by‐environment explained 9.2–19.5% of the genetic structure, with c. 4.0% of loci being affected by selection. Allele surfing and genotype–environment associations resulted in genomic mismatch under projected climate scenarios.

We illustrate that significant local adaptation, when coupled with reduced diversity as a result of demographic history, constrains potential evolutionary response to climate change. The strong signal of genomic vulnerability in P. densata may be representative for other QTP endemics.
China's Charm Defensive: Image Protection by Acquiring Mass Entertainment
Authors: Eliküçük Yıldırım Nilgün , Aslan Mesut
Published: April 2020

Focusing on discussion of China's soft power resources, this article argues that China performs two kinds of soft power strategies in developing and developed countries: offensive and defensive, respectively. While China's charm offensive aims to consolidate her comprehensive power through a development model, aid, investment, traditional culture, foreign policy, and international broadcasting in developing countries, the defensive aspect of China's soft power strategy aims to soften the rise of China with traditional culture by introducing appealing parts of Chinese culture through investments and international broadcasting in Western countries. China applies classical soft power tools in developing countries while she endeavors to protect her image in Western countries defensively. China's alternative defensive approach to soft power is mostly implemented through the acquisition of media outlets, and via the entertainment sector and gaming industry by Chinese‐owned companies. However, even in the defensive and offensive bifurcation, if charm attacks result in failure, China could turn take a defensive stance in developing countries.
Melanocortin‐1 receptor (MC1R) genotypes do not correlate with size in two cohorts of medium‐to‐giant congenital melanocytic nevi
Authors: Calbet‐Llopart Neus , Pascini‐Garrigos Mirella , Tell‐Martí Gemma , Potrony Miriam , Martins da Silva Vanessa , Barreiro Alicia , Puig Susana , Captier Guillaume , James Isabelle , Degardin Nathalie , Carrera Cristina , Malvehy Josep , Etchevers Heather C. , Puig‐Butillé Joan Anton
Published: April 2020

Congenital melanocytic nevi (CMN) are cutaneous malformations whose prevalence is inversely correlated with projected adult size. CMN are caused by somatic mutations, but epidemiological studies suggest that germline genetic factors may influence CMN development. In CMN patients from the U.K., genetic variants in MC1R, such as p.V92M and loss‐of‐function variants, have been previously associated with larger CMN. We analyzed the association of MC1R variants with CMN characteristics in two distinct cohorts of medium‐to‐giant CMN patients from Spain (N = 113) and from France, Norway, Canada, and the United States (N = 53), similar at the clinical and phenotypical level except for the number of nevi per patient. We found that the p.V92M or loss‐of‐function MC1R variants either alone or in combination did not correlate with CMN size, in contrast to the U.K. CMN patients. An additional case–control analysis with 259 unaffected Spanish individuals showed a higher frequency of MC1R compound heterozygous or homozygous variant genotypes in Spanish CMN patients compared to the control population (15.9% vs. 9.3%; p = .075). Altogether, this study suggests that MC1R variants are not associated with CMN size in these non‐UK cohorts. Additional studies are required to define the potential role of MC1R as a risk factor in CMN development.
Propranolol‐resistant infantile hemangioma successfully treated with sirolimus
Authors: Dávila‐Osorio Victoria L. , Iznardo Helena , Roé Esther , Puig Lluis , Baselga Eulalia
Published: April 2020

Infantile hemangiomas are the most common benign vascular tumors in childhood. Propranolol is the first‐line treatment for infantile hemangiomas, but failures may occur. Sirolimus, an mTOR inhibitor, is a promising drug for the treatment of vascular malformations and vascular tumors. We present the case of a child with multiple infantile hemangiomasthat was successfully treated with sirolimus and propranolol after failure of combined propranolol and prednisolone treatment.
Ultraviolet filters in sunscreen products labeled for use in children and for sensitive skin
Authors: Phadungsaksawasdi Pawit , Sirithanabadeekul Punyaphat
Published: April 2020

Background

The active ingredients in sunscreen products are ultraviolet (UV) filters, many of which are known potential allergens. The use of sunscreen in younger children and individuals with sensitive skin requires special attention, since absorption and allergen sensitization are of concern.

Objective

This study aims to evaluate the ultraviolet filters in sunscreen products labeled specifically for “kids” or as “sensitive/hypoallergenic” and compare these to general sunscreen products.

Methods

From December 2017 to March 2018, the ingredient labels on commercially available sunscreen products in Bangkok, Thailand, were analyzed.

Results

Two hundred and forty‐six sunscreen products were examined. Of these, twenty products (8.1%) were marketed for “kids.” Forty‐one products (16.6%) were labeled as “sensitive” or “hypoallergenic.” Ethylhexyl methoxycinnamate (EHMC) and benzophenone‐3 (BP3) were less prevalent in products for children [(P = .004) and (P = .029), respectively]. Eighty‐five percent of sunscreen products labeled for kids contained at least one chemical UV filter. There was no significant difference between BP3, butyl methoxydibenzoylmethane (BMDM), and octocrylene (OCR) in products labeled for sensitive skin compared to products with no specific labels. Moreover, methylene bis‐benzotriazolyl tetramethylbutylphenol (MBBT) was more commonly found in products for sensitive skin than in nonsensitive products (P = .001).

Conclusions

Common allergenic UV filters were found in sunscreens labeled as sensitive and for children. Regulations for displaying these specific labels should be established for improved benefits and safety to allergy‐prone skin.
Cutaneous manifestations of congenital malignant rhabdoid tumor: Unusual papillomatous plaques and other skin presentations
Authors: Luu Minnelly , Halbert Anne , Yan Albert , Rubin Adam , McMahon Patrick , Liang Marilyn , Vadeboncoeur Sophie , Frieden Ilona J. , Maguiness Sheilagh
Published: April 2020

Background/Objectives

Malignant rhabdoid tumors (MRT) are highly aggressive tumors with a predilection for the kidney, central nervous system, and soft tissues that usually affect young children under three years of age. Primary presentation in the skin is rarely reported, and features of the cutaneous manifestations are not well described. We report six cases of metastatic MRT that first manifested with congenital nodules and masses in the skin.

Methods

Retrospective case series.

Results

The cutaneous presentation of MRT may be heterogeneous and can present with solitary or multifocal skin lesions. Congenital polypoidal and papillomatous plaques, including those with histologic features of neurovascular hamartoma, appear to be a unique presentation of MRT in the infant.

Conclusions

Malignant rhabdoid tumor should be considered in the differential diagnosis of unusual skin tumors in neonates and infants.
Pellagra secondary to selective eating in a child with autism
Authors: Zaenglein Andrea , Martin Ashley , Carlson Lisa , Williams Keith E.
Published: April 2020

Once a significant cause of morbidity and mortality, health care providers rarely see primary pellagra in developed countries where fortification of foods with niacin is commonplace and niacin‐rich foods are generally widely available. We report a ten‐year‐old boy with autism spectrum disorder who presented with photosensitive dermatitis which resolved after vitamin supplementation and dietary changes. In this child, the pellagra developed as the result of a long‐term pattern of selective eating. Restricted diets, even to the point of nutrient deficiencies, are well‐documented among children with autism spectrum disorders (ASD).
Using cold plasma to treat warts in children: A case series
Authors: Friedman Peter C. , Fridman Gregory , Fridman Alexander
Published: April 2020

Treatment of warts is especially challenging in the pediatric patient population because of the pain associated with many of available treatments. Cold atmospheric pressure plasma is a novel treatment with expanding clinical uses for a variety of skin conditions. In this case series, we present five pediatric patients who achieved full clearance of warts with cold plasma treatment. While further studies are needed, these results are promising because of the efficacy and entirely painless nature of this treatment modality.
Impact of older age on clinicopathological and prognostic features of colon cancer in postmenopausal women
Authors: Honma Naoko , Matsuda Yoko , Arai Tomio , Kawachi Hiroshi , Akishima‐Fukasawa Yuri , Yamamoto Noriko , Ueno Masashi , Ishikawa Yuichi , Mikami Tetuo
Published: April 2020

To clarify the clinicopathological features of colorectal cancer in older people, systematic studies considering age, sex, and the tumor locus is needed. We focused on colon cancer in postmenopausal women (<70 years, n = 68 vs. ≥70 years, n = 85), and examined the effect of age on clinicopathological features. Rates of medullary carcinoma /mucinous carcinoma were higher and pathological stages at diagnosis were less advanced in patients ≥70 years compared with <70 years. Matching pathological stages, no significant difference in disease‐free interval was observed according to age; however, disease‐specific survival (DSS) was poorer in patients ≥70 years than <70 years, being significantly different in stage IV cases. Regarding post‐metastasis/recurrence (met/rec) cases, chemotherapy and surgery for metastasis were less frequent in those aged ≥70 years than <70 years. Post‐met/rec DSS was poorer in ≥70 years, those with microsatellite instability, and those without surgery for met/rec than in each counterpart; however, post‐met/rec chemotherapy exhibited no effect. Multivariate analyses revealed that an older age and no surgery for metastasis were independent predictors of disease‐specific death. These findings remained after excluding stage IV cases. Older age was a potent risk factor of rapid disease‐specific death after met/rec.
Moderators of the internal consistency of error‐related negativity scores: A meta‐analysis of internal consistency estimates
Authors: Clayson Peter E.
Published: April 2020

To ensure adequate reliability (i.e., internal consistency), it is common in studies using event‐related brain potentials (ERPs) to exclude participants for having too few trials. This practice is particularly relevant for error‐related ERPs, such as error‐related negativity (ERN), where the number of recorded ERN trials is not entirely under the researcher's control. Furthermore, there is a widespread practice of inferring reliability based on published psychometric research, which assumes that internal consistency is a universal property of ERN. The present, preregistered reliability generalization study examined whether there is heterogeneity in internal consistency estimates of ERN scores and whether contextual factors moderate reliability. A total of 189 internal consistency estimates from 68 samples nested within 43 studies (n = 4,499 total participants) were analyzed. There was substantial heterogeneity in ERN score internal consistency, which was partially moderated by the type of paradigm (e.g., Stroop, flanker), the clinical status of the sample, the ocular artifact correction procedure, measurement sensors (single versus cluster), and the approach to scoring and estimating reliability, suggesting that contextual factors impact internal consistency at the individual study level. Age, sex, year of publication, artifact rejection procedure, acquisition system, sample type (undergraduate versus community), and length of mean amplitude window did not significantly moderate reliability. Notably, the overall estimated reliability of ERN scores was below established standards. Recommendations for improving ERN score reliability are provided, but the routine failure of most ERN studies to report internal consistency represents a substantial barrier to understanding the factors that impact reliability.
Evidence‐based practice in child and adolescent mental health services – The challenge of implementing national guidelines for treatment of depression and anxiety
Authors: Westerlund Anna , Ivarsson Anneli , Richter‐Sundberg Linda
Published: April 2020

Background

Mental health problems are one of the most pressing public health concerns of our time. Sweden has seen a sharp increase in mental disorders among children and youth during the last decade. The evidence base for treatment of psychiatric conditions has developed strongly. Clinical practice guidelines aim to compile such evidence and support healthcare professionals in evidence‐based clinical decision‐making. In Sweden, the national guidelines for the treatment of depression and anxiety disorders in children and adolescents were launched in 2010. The aim of this study was two folded, (i) to explore to what extent these guidelines were known and adhered to by health professionals in Child and Adolescent Mental Health Services and (ii) to investigate factors influencing implementation of the guidelines informed by the Consolidated Framework for Implementation Research.

Methods

A qualitative approach was used, and data were collected through interviews with 18 health professionals in Child Mental Health Services in Sweden and a combination of conventional and directed content analyses was used. The Consolidated Framework for Implementation Research guided and structured data collection and analysis.

Results

The guidelines were largely unknown by health professionals in Child Mental Health Services in all the clinics investigated. Adherence to guideline recommendations was reported as very low. Barriers to implementation were found in relation to the characteristics of the intervention, outer setting, inner setting and characteristics of the individuals involved.

Conclusions

The government initiative to develop and disseminate the guidelines seems to have made very little impact on health professionals’ clinical practice. The guidelines were poorly aligned with the health professionals’ knowledge and beliefs about effective mental health services for children and youth with depression and anxiety disorders. Suggestions for future efforts to improve the development and implementation of guidelines in Child Mental Health Services settings are given.
Patterns, quality and appropriateness of surgical referrals in Malawi
Authors: Pittalis Chiara , Brugha Ruairi , Bijlmakers Leon , Mwapasa Gerald , Borgstein Eric , Gajewski Jakub
Published: April 2020

Objectives

Reliable referral systems are essential to the functionality and efficiency of the wider health care system in low‐ and middle‐income countries (LMICs), particularly in surgery as the disease burden is growing while resources remain constrained and unevenly distributed. Yet, this is a critically under‐researched area. This study aimed to provide a comprehensive assessment of surgical referral systems in a LMIC, Malawi, with a view to shedding light on this important aspect of public health and share lessons learned.

Methods

We conducted a prospective analysis of all inter‐hospital referrals received at Queen Elizabeth Central Hospital (QECH) in 2014–2015. A subsample of 255 referrals was assessed by three independent surgical experts against necessity and quality of the transfer to identify any inefficiencies in the referral process.

Results

1317 patients were referred to QECH during the study period (average 53/month), 80% sent by government district hospitals. One in 3 cases were referred unnecessarily, many of which could have been managed locally. In 82% of cases, there was no communication with QECH prior to referral, 41% had incorrect/incomplete diagnosis by the referring clinicians and 39% of referrals were not timely.

Conclusions

Our findings provide the first evidence on the state of the surgical referral system in Malawi and contribute to building the body of knowledge necessary to inform system improvements. Responses should include reducing inappropriate use of specialist care and ensuring better care pathways for surgical patients, especially in rural areas, where access to specialist expertise is not available at present.
An extended root phenotype: the rhizosphere, its formation and impacts on plant fitness
Authors: de la Fuente Cantó Carla , Simonin Marie , King Eoghan , Moulin Lionel , Bennett Malcolm J. , Castrillo Gabriel , Laplaze Laurent
Published: April 2020

Plants forage soil for water and nutrients, whose distribution is patchy and often dynamic. To improve their foraging activities, plants have evolved mechanisms to modify the physicochemical properties and microbial communities of the rhizosphere, i.e. the soil compartment under the influence of the roots. This dynamic interplay in root−soil−microbiome interactions creates emerging properties that impact plant nutrition and health. As a consequence, the rhizosphere can be considered an extended root phenotype, a manifestation of the effects of plant genes on their environment inside and/or outside of the organism. Here, we review current understanding of how plants shape the rhizosphere and the benefits it confers to plant fitness. We discuss future research challenges and how applying their solutions in crops will enable us to harvest the benefits of the extended root phenotype.
Fiscal incentives and local tax competition: Evidence from China
Authors: Liu Yongzheng , Tai Hang , Yang Chenping
Published: April 2020

This paper explores how fiscal incentives affect capital tax decisions by local governments in the Chinese context. We develop a model in which local governments, facing different fiscal incentives, compete for mobile capital over corporate taxes. The key prediction of the model, borne out in data from Chinese cities over the years 2004–13, is that an increase in the local corporate income tax‐sharing ratio, proxying local fiscal incentives, makes city governments’ horizontal tax reactions stronger. Our results contribute to the fiscal federalism literature by providing evidence in support of the argument that fiscal incentives faced by local governments significantly shape their policy choices. Additionally, we provide explicit evidence on local tax competition within provinces in China, which has long been regarded as one of the driving forces of China's rapid economic growth.
Chrysomya bezziana (Diptera: Calliphoridae) infestation in two Malaysian cats treated with oral lotilaner
Authors: Han Hock Siew , Yasmin Lynn
Published: April 2020

The most common fly species associated with screwworm myiasis in Southeast Asia is Chrysomya bezziana (Ch. bezziana), the Old‐World screwworm. Treatment of screwworm myiasis in cats traditionally has comprised subcutaneous injection of ivermectin or oral administration of nitenpyram, combined with aggressive tissue debridement and larval removal under general anaesthesia. Two cats diagnosed with cutaneous myiasis caused by the larvae of Ch. bezziana were treated with lotilaner. In both cats, a single dose of lotilaner at 6–26 mg/kg, killed all larvae within 24 h, negating the need for general anaesthesia. Both cats were simultaneously infested with Lynxacarus radovskyi (L. radovskyi) which also was eradicated with lotilaner. No adverse reactions were observed and both cats recovered without complications.
‘Should I Ignore the Promotion System and Stay or I Should Quit’: An Examination of the Experiences of Teachers with the Promotion Process in the Ghana Education Service
Authors: Kanwetuu Vincent De Paul , Brenyah Joseph Asomaning , Obeng Bernard
Published: April 2020

Promotion is a key determinant of employee advancement on the organizational ladder. However, in the Ghana Education Service, there are several reports of irregularities in the process which make the promotion less of a merit-based mechanism. The purpose of this study, therefore, was to examine teachers’ perception of fairness in the promotion process and how that affects their willingness to stay in the Service and teach effectively. Using a descriptive survey involving both close-ended and open-ended questions, the opinions and experiences of 342 randomly sampled teachers in the Ejisu-Juaben Municipality were examined using correlations and binary logistic regressions as well as thematic analysis. The results show that fairness in the promotion process was a significant contributor to teacher retention and effective teaching. However, the process is tainted with favoritism and partiality. Governments should, therefore, not be interested in incentivization only as a retention strategy but also come out with strategies aimed at ensuring transparency in the promotion process to make it a performance-based mechanism that sieves and preserves best talents.
Reviewer Acknowledgements
Authors: Smith Robert
Published: April 2020

Journal of Education and Training Studies (JETS) would like to acknowledge the following reviewers for their assistance with peer review of manuscripts for this issue. Many authors, regardless of whether JETS publishes their work, appreciate the helpful feedback provided by the reviewers. Their comments and suggestions were of great help to the authors in improving the quality of their papers. Each of the reviewers listed below returned at least one review for this issue.Reviewers for Volume 8, Number 5 Gianpiero Greco, University of Study of Bari, ItalyGuilherme Tucher, Universidade Federal do Rio de Janeiro (UFRJ), BrazilJohn Cowan, Edinburgh Napier University, UKJonathan Chitiyo, University of Pittsburgh Bradford, USAKeyla Ferrari Lopes, UNICAMP, BrazilLeila Youssef, Arab Open University, LebanonMaria Rachel Queiroz, Universidade do Estado da Bahia, BrazilMaurizio Sajeva, Pellervo Economic Research PTT, FinlandMelike Özüdoğru, Manisa Celal Bayar University, TurkeyMeral Seker, Alanya Alaaddin Keykubat University, TurkeyMuhammad Haris Effendi-Hasibuan, Universitas Jambi, IndonesiaRichard H. Martin, Mercer University, USASandro Sehic, Oneida BOCES, USAShu-wen Lin, Sojo University, JapanThada Jantakoon, Rajabhat Maha Sarakham University, ThailandWenjuan Sang, Indiana University, USA Robert SmithEditorial AssistantOn behalf of,The Editorial Board of Journal of Education and Training StudiesRedfame Publishing9450 SW Gemini Dr. #99416Beaverton, OR 97008, USAE-mail 1: jets@redfame.comE-mail 2: jets@redfame.orgURL: http://jets.redfame.com
Dynamic Analysis and Design of an Innovative Sit-to-Stand Gait Trainer
Authors: Yagiela Michael , Johnson Richard W. , Schmitz Anne , Steinbrink Scott , Piovesan Davide
Published: April 2020

This paper illustrates three examples of how to implement dynamic lifting support, including the solution adopted in the Up n’ Free® (Easy-Walking Inc., Maple Glen, PA). The Up n' Free system can lift the user from a seated posture to a standing position through the employment of a four-bar mechanism and gas piston. When the user is standing, the mechanism can provide partial compensation from gravity to help the user regain mobility. The compensation can be provided while standing without taxing the arms and shoulders with the use of crutches. By using this system, users can sit and stand without assistance from another person and can also receive compensation for gravity loads while walking. This group is not involved with the design and commercialization of the Up n' Free product but uses that design as a reference of comparison for two additional actuation solutions, one of which involves a cam acting on a rubber band. The piston in the Up n' Free is positioned between the bottom part of the walker frame and the four-bar mechanism. We propose a more compact configuration where the piston is located within the four-bar mechanism. This work discusses the pros and cons of the two gas spring cylinder configurations. Common problems arising with both configurations are the difficulty of regulating the minimum and maximum force at the seat, as well as the inability to define a force profile for the transition from sitting to standing. Thus, a new actuation system to implement the dynamic lifting support is proposed, where the force profile is modulated using a cam acting on an elastic band. We were able to define a linear profile of the force during the transition from sit-to-stand, thereby avoiding sudden increases in force that are typical of actuation solutions encompassing gas pistons acting on a variable moment arm.
Singular System-Based Approach for Active Vibration Control of Vehicle Seat Suspension
Authors: Li Wenxing , Du Haiping , Feng Zhiguang , Ning Donghong , Li Weihua , Sun Shuaishuai , Tu Lixin , Wei Jumei
Published: April 2020

This paper proposes a singular system-based approach for active vibration control of vehicle seat suspensions, where the drivers' acceleration is augmented into the conventional seat suspension model together with seat suspension deflection and relative velocity as system states to make the suspension model as a singular system. In this novel seat suspension system, all the system states are easy to measure in real-time. A friction observer is applied to estimate the real system friction and an H∞ controller is designed to achieve the optimal ride comfort performance with consideration of the friction compensation, actuator saturation, and time delay issues. The cone complementarity linearization (CCL) algorithm is applied to solve the nonlinear constraints. The experimental results show that good ride comfort performance can be achieved by the proposed controller in both the time and frequency domain compared with the uncontrolled seat suspension.
A Cascaded Optimization Approach for Modeling a Professional Driver's Driving Style
Authors: Anderson Jeffery Ryan , Ayalew Beshah
Published: April 2020

In the context of minimum-time vehicle maneuvering, previous works have shown that different professional drivers drive differently while achieving nearly identical performance. In this paper, a cascaded optimization framework is presented for modeling individual driving styles of professional drivers. Therein, an inner loop model predictive controller (MPC) finds the optimal vehicle inputs that minimize a blended-cost function over each receding horizon. The outer loop of this framework is an optimization computation which finds the optimal weights for each local MPC horizon that best fit data obtained from onboard vehicle measurements of the targeted drivers to the simulation of the maneuver under the cascaded control. This cascaded optimization is exercised for a case study on Sebring International Raceway where two different professional drivers were able to achieve nearly identical lap times while adopting different driving styles. It will be shown that this framework is able to model key differences in style between the two drivers during a particular corner. The models of the individual drivers are then fixed, and another optimization is used to tune tire parameters to suit each driving style and illustrate the utility of the approach.
Thermal Performance of Ammonia in Dual Mixed Refrigerant Cycle of Natural Gas Liquefaction Process
Authors: Soujoudi Ray , Manteufel Randall
Published: April 2020

Mixed refrigerant (MR) system is commonly used for a liquefaction process of liquid natural gas (LNG) plants due to its higher efficiency of heat transfer rate compared to pure refrigerants. The performance of MR system is highly dependent on the variable refrigerant composition, which is challenging to obtain in a practical LNG plant setting. To address this challenge, this study investigates a unique approach to improve the exergy efficiency of liquefaction cycle employing ammonia in the mixture while keeping the MR molar composition constant in dual mixed refrigerant (DMR) cycle. A control strategy is proposed to regulate the MR flowrate through flow control sensors and a series of Joule-Thomason (JT) valves to sustain the desired efficiency of the cycle under various plant’s operation conditions. The robustness and adaptability of two proposed MR compositions were examined under eight cases by varying natural gas (NG) feed pressure and methane concentration. Composite curve plots were utilized as a tool to control the minimum temperature approach (MTA) and to improve exergy efficiency of the cycle. Furthermore, findings revealed that mixtures which included ammonia yielded a reduction in the number of compressors, as well as a reduced the overall amount of compressors rate of shaft work required for the liquefaction cycle. The results emphasize that DMR is most efficient when NG methane concentration is at 75%. Furthermore, the compressor rate of shaft work reduced by 13.3%, while exergy efficiency of the cycle increased by 14.3%, when natural gas methane concentration reduced from 90% to 75%.
Effects of High Fuel Loading and CO2 Dilution on Oxy-Methane Ignition Inside a Shock Tube at High Pressure
Authors: Laich Andrew R. , Baker Jessica , Ninnemann Erik , Sigler Clayton , Naumann Clemens , Braun-Unkhoff Marina , Vasu Subith S.
Published: April 2020

Ignition delay times were measured for methane/O2 mixtures in a high dilution environment of either CO2 or N2 using a shock tube facility. Experiments were performed between 1044 K and 1356 K at pressures near 16 ± 2 atm. Test mixtures had an equivalence ratio of 1.0 with 16.67% CH4, 33.33% O2, and 50% diluent. Ignition delay times were measured using OH* emission and pressure time-histories. Data were compared to the predictions of two literature kinetic mechanisms (ARAMCO MECH 2.0 and GRI Mech 3.0). Most experiments showed inhomogeneous (mild) ignition which was deduced from five time-of-arrival pressure transducers placed along the driven section of the shock tube. Further analysis included determination of blast wave velocities and locations away from the end wall of initial detonations. Blast velocities were 60–80% of CJ-Detonation calculations. A narrow high temperature region within the range was identified as showing homogenous (strong) ignition which showed generally good agreement with model predictions. Model comparisons with mild ignition cases should not be used to further refine kinetic mechanisms, though at these conditions, insight was gained into various ignition behavior. To the best of our knowledge, we present first shock tube data during ignition of high fuel loading CH4/O2 mixtures diluted with CO2 and N2.
Probabilistic Modeling of Horizontal Wave-in-Deck Loads on a Square Concrete Deck
Authors: Shen Zhonghui , Wei Kai , Deng Peng , Zhong Xi , Qin Shunquan
Published: April 2020

The square concrete deck is being used as an elevated transition piece in offshore structure but has a large exposure area to extreme waves. This study focused on the horizontal wave-in-deck loads on the square concrete deck. Wave flume tests were carried out to investigate the wave-in-deck loads on a specimen of a square concrete deck. Horizontal wave-in-deck loads on the specimen with ten different structural orientations were measured under three nonlinear regular wave trains. A novel analytical model of the horizontal wave-in-deck loads on the square thick deck was proposed by including both impact maxima and pulse shape function. The temporal development of the resultant horizontal wave-in-deck loads was studied from the measured forces through data post-processing. The effects of structural orientation, inundation depth, and the correlation between the rise and decay time were considered based on the experimental data. The marginal distributions of the impact maxima and rise time for the horizontal wave-in-deck loads on the square deck were investigated, and the joint probability model of impact maxima and rise time was finally developed using Plackett copula. The research provides a useful stochastic model in assessing the wave-in-deck loads on the square concrete deck.
Human Reliability Analysis of Ship Maneuvers in Harbor Areas
Authors: de Abreu Danilo Taverna Martins Pereira , Maturana Marcos Coelho , López Droguett Enrique Andrés , Martins Marcelo Ramos
Published: April 2020

During a ship life cycle, one of the most critical phases in terms of safety refers to harbor maneuvers, which take place in restricted and congested waters, leading to higher collision and grounding risks in comparison to open sea navigation. In this scenario, a single accident may stop the harbor's traffic as well as incur in patrimonial damage, environmental pollution, human casualties, and reputation losses. In order to support the vessel's captain during the maneuver, local experienced maritime pilots stay on board coordinating the ship navigation while in restricted waters. Aiming to assess the main factors contributing to human errors in pilot-assisted harbor ship maneuvers, this work proposes a Bayesian network model for human reliability analysis (HRA), supported by a prospective human performance model for quantification. The novelty of this work resides into two aspects: (a) incorporation of harbor specific conditions for maritime navigation HRA, including the performance of ship's crew and maritime pilots and (b) the use of a prospective human performance model as an alternative to expert's opinion for quantification purposes. To illustrate the usage of the proposed methodology, this paper presents an analysis of the route keeping task along waterways, starting from the quantification of human error probabilities (HEP) and including the ranking of the main performance shaping factors that contribute to the HEP.
Role of substrate temperature and tellurium flux on the electrical and optical properties of MBE grown GeTe and Sb2Te3 thin films on GaAs (100)
Authors: Podpirka Adrian , Gagnon Jarod , Zgrabik Christine , Pierce Jonathan , Shrekenhamer David
Published: April 2020

Van der Waals layered GeTe/Sb2Te3 chalcogenide superlattices have demonstrated outstanding performance for use in dynamic resistive memories in what is known as interfacial phase change memory devices due to their low power requirement and fast switching. These devices are made from the periodic stacking of nanometer thick crystalline layers of chalcogenide phase change materials. The mechanism for this transition is still debated, though it varies from that of traditional phase change melt-quench transition observed in singular layers of GeTe and Sb2Te3. In order to better understand the mechanism and behavior of this transition, a thorough study on each constituent layer and the parameters for growth via molecular beam epitaxy was performed. In this work, the authors show the effect of tellurium overpressure and substrate temperature on the growth of thin film GeTe and Sb2Te3 on (100) GaAs. The authors demonstrate the significant role during growth that tellurium overpressure plays in the transport properties of both GeTe and Sb2Te3, as well as the negligible impact this has on both the structural and optical properties. The highest mobility recorded was 466 cm2/V s with a p-type bulk carrier concentration of 1.5 × 1019 cm−3 in Sb2Te3. For GeTe, the highest achieved was 55 cm2/V s at a p-type bulk carrier concentration of 8.6 × 1020 cm−3. The authors discuss transport properties, orientation, and crystal structure and the parameters needed to achieve high mobility chalcogenide thin films.
Time-domain impedance boundary condition modeling with the discontinuous Galerkin method for room acoustics simulations
Authors: Wang Huiqing , Hornikx Maarten
Published: April 2020

The time-domain nodal discontinuous Galerkin (TD-DG) method is emerging as a potential wave-based method for three-dimensional (3D) room acoustics modeling, where high-order accuracy in the low frequency range, geometrical flexibility, and accurate modeling of boundary conditions are of critical importance. This paper presents a formulation of broadband time-domain impedance boundary conditions (TDIBCs) of locally-reacting surfaces in the framework of the TD-DG method. The formulation is based on the approximation of the plane-wave reflection coefficient at normal incidence in the frequency domain using a sum of template rational functions, which can be directly transformed to the time-domain. The coupling of the TDIBCs with the discontinuous Galerkin discretization is achieved through the characteristic waves of the upwind flux along the boundary, where a series of first-order auxiliary differential equations is time-integrated in a high-order way. To verify the performance of the formulation, various numerical tests of single reflection scenarios are shown to demonstrate the cost efficiency and memory-efficiency of high-order basis functions, among which a 3D application to an impedance boundary of rigidly backed glass-wool baffle for room acoustic purposes is presented.
Dropping the Amateur: The International Association of Athletics Federations and the Turn Toward Professionalism
Authors: Henning April , Krieger Jörg
Published: April 2020

When the International Association of Amateur Athletics (IAAF) changed its name to International Association of Athletics Federations in 2001, it was more than an acknowledgment of the organization’s acceptance of professional athletes. Rather, this change symbolized a shift in thinking about the nature of athletics, what athletics competitions represented, and the commercialization of the sport that had been decades in the making. This article will consider the IAAF’s pursuit to maintain control over global athletics through its transition from an amateur sport federation to a professional sport governing body. Drawing on official documents and personal archives of IAAF officials, the authors trace the internal views and debates, beginning with the IAAF’s fight to maintain amateurism against collective pushback over issues of athlete pay, to the full acceptance of professionalism. The main focus of this article lies in the transition period in the 1980s and 1990s. The authors show how dropping the amateur from the name reflected not only the new embrace of professional athletes, but also the organizational turn away from amateur athletics. The authors will identify the processes that finally forced the breakdown of amateurism and ushered in a new era of professional athletics.
Cathelicidins Mitigate Staphylococcus aureus Mastitis and Reduce Bacterial Invasion in Murine Mammary Epithelium
Authors: Cavalcante Paloma Araujo , Knight Cameron G. , Tan Yi-Lin , Monteiro Ana Paula Alves , Barkema Herman W. , Cobo Eduardo R.
Published: April 2020

Staphylococcus aureus
, an important cause of mastitis in mammals, is becoming increasingly problematic due to the development of resistance to conventional antibiotics. The ability of
S. aureus
to invade host cells is key to its propensity to evade immune defense and antibiotics. This study focuses on the functions of cathelicidins, small cationic peptides secreted by epithelial cells and leukocytes, in the pathogenesis of
S. aureus
mastitis in mice.
Evaluation of the BioFire FilmArray Pneumonia Panel for Detection of Viral and Bacterial Pathogens in Lower Respiratory Tract Specimens in the Setting of a Tertiary Care Academic Medical Center
Authors: Webber Daniel M. , Wallace Meghan A. , Burnham Carey-Ann D. , Anderson Neil W.
Published: April 2020

Our objective was to evaluate the diagnostic yield and accuracy of the BioFire FilmArray pneumonia panel (BFPP) for identification of pathogens in lower respiratory tract specimens (
n
 = 200) from emergency department (ED) and intensive care unit (ICU) patients at a tertiary care academic medical center. Specimens were collected between January and November 2018, from patients ≥18 years of age, and culture was performed as part of standard-of-care testing.
Redefining the Tonto Group of Grand Canyon and recalibrating the Cambrian time scale
Authors: Karlstrom K.E. , Mohr M.T. , Schmitz M.D. , Sundberg F.A. , Rowland S.M. , Blakey R. , Foster J.R. , Crossey L.J. , Dehler C.M. , Hagadorn J.W.
Published: April 2020

We applied tandem U-Pb dating of detrital zircon (DZ) to redefine the Tonto Group in the Grand Canyon region (Arizona, USA) and to modify the Cambrian time scale. Maximum depositional ages (MDAs) based upon youngest isotope-dilution DZ ages for the Tapeats Sandstone are ≤508.19 ± 0.39 Ma in eastern Grand Canyon, ≤507.68 ± 0.36 Ma in Nevada, and ≤506.64 ± 0.32 Ma in central Arizona. The Sixtymile Formation, locally conformable below the Tapeats Sandstone, has a similar MDA (≤508.6 ± 0.8 Ma) and is here added to the Tonto Group. We combined these precise MDAs with biostratigraphy of trilobite biozones in the Tonto Group. The Tapeats Sandstone is ca. 508–507 Ma; the Bright Angel Formation contains Olenellus, Glossopleura, and Ehmaniella biozones and is ca. 507–502 Ma; and the Muav Formation contains Bolaspidella and Cedaria biozones and is ca. 502–499 Ma. The Frenchman Mountain Dolostone is conformable above the Muav Formation and part of the same transgression; it replaces McKee’s Undifferentiated Dolomite as part of the Tonto Group; it contains the Crepicephalus Biozone and is 498–497 Ma. The Tonto Group thickens east to west, from 250 m to 830 m, due to ∼300 m of westward thickening of carbonates plus ∼300 m of eastward beveling beneath the sub-Devonian disconformity. The trilobite genus Olenellus occurs in western but not eastern Grand Canyon; it has its last appearance datum (LAD) in the Bright Angel Formation ∼45 m above the ≤507.68 Ma horizon. This extinction event is estimated to be ca. 506.5 Ma and is two biozones below the Series 2–Miaolingian Epoch boundary, which we estimate to be ca. 506 Ma. Continued tandem dating of detrital grains in stratigraphic context, combined with trilobite biostratigraphy, offers rich potential to recalibrate the tempo and dynamics of Cambrian Earth systems.