bluuebunny/crossref_metadata_2025 huggingface dataset:
Staging environmental risk: a methodological cosmopolitanism approach to Chinese media events
Authors: MAO ZHIFEI , QIU JACK LINCHUAN
Published: December 2019

The aim of this study is to enrich Beck's (2016) concept of methodological cosmopolitanism and digital metamorphosis from the perspective of communication researchers using a ‘media event', namely the live broadcasting of history through communication technology (Dayan and Katz 1992) as the research unit. Based on our observation of media events of environmental crises in China, we argue that digital metamorphoses are happening, albeit in a complicated form. These disruptive events that netizens evoke, participate in and resolve make a stronger and longer lasting impact on the social consensus about environmental protections than do pre‐set pseudo‐events. The effects of the digital empowerment of people are, however, case specific and the nation‐state still dominates many media events pertaining to environmental crises.
The hostile environment, Brexit, and ‘reactive‐’ or ‘protective transnationalism’
Authors: REDCLIFT VICTORIA MELANGEDD , RAJINA FATIMA BEGUM
Published: December 2019

The ‘reactive transnationalism hypothesis’ posits a relationship between discrimination and transnational practice. The concept has generally been studied using quantitative methods, but a qualitative approach augments our understanding of two context‐specific dimensions: thenatureof the discrimination involved, and thetypesof transnational behaviour that might be affected. Drawing on in‐depth interviews with Bangladesh‐origin Muslims in London, Luton and Birmingham, in the UK, we demonstrate how anti‐Asian and anti‐Muslim racism have been conflated with intensified anti‐migrant racism in the context of ‘hostile environment’ immigration policies and the EU referendum (Brexit), producing an amplification of racist discourses associated with purging the body politic of its non‐white bodies. The insecurity generated is altering some people's relationships to Bangladesh, incentivizing investment in land and property ‘back home'. While this represents an example of ‘reactive transnationalism', we argue that ‘protective transnationalism’ might be a more appropriate way of describing the processes at work.
Safety and efficacy of turoctocog alfa in the prevention and treatment of bleeds in previously untreated paediatric patients with severe haemophilia A: Results from the guardian 4 multinational clinical trial
Authors: Yaish Hassan , Matsushita Tadashi , Belhani Meriem , Jiménez‐Yuste Víctor , Kavakli Kaan , Korsholm Lars , Matytsina Irina , Philipp Claire , Reichwald Kirsten , Wu Runhui
Published: December 2019

Introduction

Turoctocog alfa is a recombinant, B domain‐truncated factor VIII (FVIII) approved for patients with haemophilia A.

Aim

To evaluate the safety and efficacy of turoctocog alfa in previously untreated patients (PUPs) with severe haemophilia A.

Methods

Guardian 4 was a multicentre, multinational, non‐randomized, open‐label phase 3 trial comprising a main and extension phase. The former concluded once ≥ 50 patients had received treatment for ≥ 50 exposure days (EDs) or developed inhibitors. Patients received turoctocog alfa intravenously for prevention and treatment of bleeds. The primary endpoint was the incidence rate of FVIII inhibitors (≥0.6 Bethesda Units) reported during the first 50 EDs.

Results

Of the 58 patients who completed the main phase, 25 (43.1%) patients developed inhibitors (detected within 6‐24 [mean: 14.2] EDs from treatment start). High‐risk mutations were identified in 60% of patients who developed inhibitors in the main phase and were a significant predictor of inhibitor development (P = .003). Of the 21 patients who started immune tolerance induction therapy, 85.7% completed treatment with a negative inhibitor test (note that data on the last 3 patients completing ITI are based on information collated from sites prior to the final database lock). Haemostatic response (including missing values as failure) was rated as ‘excellent’ or ‘good’ for 86.1% of bleeds occurring during prophylaxis. The estimated mean annualized bleeding rate for patients on prophylaxis was 4.26 bleeds/patient/year (95% CI: 3.34 − 5.44).

Conclusions

Turoctocog alfa was effective at preventing and stopping bleeds and was well tolerated. Inhibitor development was within the expected range for this PUP population.
Toward the fabrication of extruded microstructured bioresorbable phosphate glass optical fibers
Authors: Gallichi‐Nottiani Duccio , Pugliese Diego , Giovanna Boetti Nadia , Milanese Daniel , Janner Davide
Published: December 2019

The steps toward the fabrication of directly extruded microstructured fiber preforms made of a bioresorbable phosphate glass are herein presented, analyzing the features of the process from the glass synthesis to the manufacturing of the fiber. The realization of these fibers leverages on three main pillars: an optically transparent bioresorbable glass, its extrusion into a preform, and the fiber drawing. The glass has been designed and carefully prepared in our laboratory to be dissolvable in a biological fluid while being optically transparent and suitable for both preform extrusion and fiber drawing. To support the production of an optimized die for the preform extrusion, a simplified laminar flow model simulation has been employed. This model is intended as a tool for a fast and reliable way to catch the complex behavior of glass flow during each extrusion and can be regarded as an effective design guide for the dies to fulfill the specific needs for preform fabrication. After die optimization, extrusion of a capillary was realized, and a stacking of extruded tubes was drawn to produce a microstructured optical fiber made of bioresorbable phosphate glass.
Clinical leadership development in Australian healthcare: a systematic review
Authors: Pizzirani Bengianni , O'Donnell Renée , Skouteris Helen , Crump Bernard , Teede Helena
Published: December 2019

Despite clear priority and high costs of leadership capability programmes in healthcare, and significant investments into improving clinical leadership, there remains a prominent gap around evidence of effectiveness or impact on patient outcomes in Australia. We aimed to conduct a systematic review on postgraduate clinical leadership programmes to gather learnings on the processes, theoretical underpinnings, and impact of such programmes for medical and other health professionals. Our search included empirical, peer‐reviewed evaluations of Australian clinical leadership development programmes published between November 2008 and March 2019 and yielded 3284 records. Four studies met criteria. Findings revealed that currently, little value is placed on formal evaluations and peer‐reviewed publication including assessment of individual, organisational or system level impacts of clinical leadership development programmes, with limited evidence available on effective approaches to clinical leadership development in the Australian healthcare system.
Maternal neural reactivity during pregnancy predicts infant temperament
Authors: Brooker Rebecca J. , Kiel Elizabeth J. , MacNamara Annmarie , Nyman Tristin , John‐Henderson Neha A. , Schmidt Louis A. , Van Lieshout Ryan J.
Published: December 2019

Maternal biological systems impact infant temperament as early as the prenatal period, though the mechanisms of this association are unknown. Using a prospective, longitudinal design, we found that maternal (N = 89) amplitudes of the late positive potential (LPP) in response to negative stimuli during the second, but not the third, trimester of pregnancy predicted observed and physiological indices of temperamental reactivity in infants at age 4 months. Maternal LPP was positively associated with observed infant fear and negatively associated with frontal EEG asymmetry and cortisol reactivity in infants at age 4 months. Results identify a putative mechanism, early in pregnancy, for the intergenerational transmission of emotional reactivity from mother to infant.
Effectiveness of adjuvant treatment for morcellated, International Federation of Gynecology and Obstetrics stage I uterine leiomyosarcoma: A Korean multicenter study
Authors: Kim Se Ik , Choi Chel Hun , Kim Kidong , Hong Deok Ho , Park Jeong‐Yeol , Kwon Byung Su , Lee Keun Ho , Hong Dae Gy , Shin So‐Jin , Park Sang‐Il , Kim Yun Hwan , Lee Seung‐Ho , Lee Sanghoon , Hong Jin Hwa , Lee Jung‐Yun , Kim Yong Beom , No Jae Hong , Suh Dong Hoon
Published: December 2019

Aim

To evaluate the effectiveness of adjuvant treatment for morcellated, uterus‐confined leiomyosarcoma in a multicenter setting.

Methods

We identified patients with International Federation of Gynecology and Obstetrics stage I uterine leiomyosarcoma primarily treated with surgery between 2003 and 2016. Among them, patients who underwent one of the following morcellation methods were included: (i) power morcellation; (ii) intracorporeal morcellation using scalpels or electrocautery; and (iii) vaginal morcellation. Patients' survival outcomes were compared according to the implementation of adjuvant treatment.

Results

From 13 institutions, 55 patients were included; 31 for adjuvant treatment group and 24 for surgery only group. The clinicopathological characteristics including the mass size, morcellation methods, extent of surgery, and mitotic count were similar between the groups. In the adjuvant treatment group, 67.7%, 19.4% and 12.9% of patients received chemotherapy, chemoradiation and radiation, respectively. After a median follow‐up of 50.5 months, the adjuvant treatment and surgery only groups showed similar overall survival (5‐year rate, 92.0% vs 90.4%; P = 0.959). No significant difference in progression‐free survival was observed between the two groups (3‐year rate, 46.1% vs 78.2%; P = 0.069). On multivariate analyses, adjuvant treatment did not affect progression‐free survival (adjusted HR, 2.138; 95% CI, 0.550–8.305; P = 0.273). The adjuvant treatment group showed a trend towards more common distant metastasis, compared to the surgery only group (25.8% vs 4.2%; P = 0.062). The incidences of pelvic, retroperitoneal, and abdominal recurrences were not different between the groups.

Conclusion

Despite its frequent use in clinical practice, adjuvant treatment did not improve the survival outcomes of patients with morcellated, International Federation of Gynecology and Obstetrics stage I uterine leiomyosarcoma.
Proportion of abnormal second 50‐g glucose challenge test in gestational diabetes mellitus screening using the two‐step method in high‐risk pregnant women
Authors: Glaharn Pianpun , Chumworathayi Bandit , Kongwattanakul Kiattisak , Sutthasri Nutwara , Wiangyot Phimwimon
Published: December 2019

Aims

To determine the merit of repeating 50‐g glucose challenge test (50‐g GCT) at 24–28 weeks of gestation in high‐risk pregnant women and the prevalence of early‐ and late‐onset gestational diabetes mellitus (GDM).

Methods

This study was conducted in 1447 pregnant women, 344 of them were at risks for GDM undergoing screening by two‐step method at first visit. Data were not completely collected in 47 women leaving only 297 for analyses. Fifty‐six of 297 pregnant women were diagnosed as early‐onset GDM (18.8%) and the other 241 pregnant women were consequently screened at 24–28 weeks of gestation to identify late‐onset GDM. Screening data were retrieved, including risks, laboratory test results, baseline characteristics and diagnostic outcomes. Proportion of abnormal second 50‐g GCT and the prevalence of late‐onset GDM were estimated.

Results

The prevalence of late‐onset GDM was 17.8%. Among groups of normal 50‐g GCT, abnormal 50‐g GCT and abnormal 1 oral glucose tolerance test (OGTT) value at first test, the proportions of abnormal 50‐g GCT at second test were 38.3%, 59.5% and 79.3%, and the prevalence of late‐onset GDM among each group were 18.8%, 8.3% and 41.4%, consecutively. This lead to prevalence of GDM in this high‐risk group of 33.3% and overall among 1447 women was 7.9%.

Conclusion

There were high proportions of abnormal 50‐g GCT at second test in the groups with abnormal 50‐g GCT and abnormal 1 OGTT value at first test (59.5% and 79.3%). Authors suggested doing OGTT without repeating 50‐g GCT in these groups coming at 24–28 weeks of gestation.
Pilot study establishing a nomogram of yolk sac growth during the first trimester of pregnancy
Authors: Detti Laura , Roman Robert A. , Goedecke Patricia J. , Christiansen Mary E. , Peregrin‐Alvarez Irene , Ikwuezunma Gini , Francillon Ludwig
Published: December 2019

Aim

The yolk sac (YS) has been reported as a reliable predictor of adverse pregnancy outcomes, however, it has always been evaluated cross‐sectionally with a single ultrasound per patient. We sought to validate the use of YS dimensions in serial ultrasounds throughout the first 10 weeks of singleton and multiple gestations.

Methods

This was a prospective cohort study where YS diameters were serially obtained with 2D ultrasound in singleton and multiple gestations from 5 to 11 weeks. Nonparametric test were used for comparisons with P < 0.05 indicating significance.

Results

One hundred ninety‐three patients were included, 42 twins (3 monochorionic and 39 dichorionic), 2 triplets (monochorionic twins plus a singleton) and 148 singleton pregnancies (238 total fetuses). There was no difference in YS dimensions in singleton versus multiple pregnancies. Starting at 5 weeks' gestation, the YS increased 0.4 mm (95% CI 0.3–0.5 mm) per week until 10 weeks' gestation. Forty‐five fetuses were lost in the first trimester. The risk of pregnancy loss was higher with a large YS until 8 weeks (P ≤ 0.001), while after 8 weeks it was higher with a small YS (P < 0.005).

Conclusion

We established a nomogram of YS development during the first 10 weeks of pregnancy. The YS reliably detected pregnancies that ended in loss as early as 6 weeks' gestation. The YS was either smaller or larger than in ongoing pregnancies. While all pregnancies with large YS were lost within 10 weeks, those with smaller YS were lost beyond the first 10 weeks.
Transient elastography in DAA era. Relation between post‐SVR LSM and histology
Authors: Martínez‐Campreciós Joan , Bonis Puig Sara , Pons Delgado Mònica , Salcedo Allende María Teresa , Mínguez Rosique Beatriz , Genescà Ferrer Joan
Published: December 2019

The natural history of HCV chronic infection has drastically changed after direct‐acting antiviral treatment. Due to the high sustained virological response (SVR) achieved, noninvasive estimation of liver fibrosis regression has become a major key point. The present study tries to evaluate the relation between liver histology and liver stiffness measurement (LSM) by transient elastography (TE) after SVR.
Pitfalls and requirements in quantifying asymmetric mitotic segregation
Authors: Loeffler Dirk , Schneiter Florin , Schroeder Timm
Published: December 2019

The asymmetric inheritance of NUMB during mitosis determines future daughter cell fates in multiple model organisms. NUMB asymmetric inheritance has also been postulated for hematopoietic stem cell (HSC) divisions but remained controversial until recently. To reconcile conflicting reports, we revisited the evidence for asymmetric inheritance of NUMB during HSC divisions. We demonstrate that previously used strategies to identify dividing cells in fixed samples suffer from multiple systematic errors. Nonmitotic cells in close proximity are frequently mistaken as dividing cells, while mitotic cells are not detected. Furthermore, microtubule depolymerization by either nocodazole or low temperatures prevents the reliable detection of mitosis and introduces mitotic artifacts. Without artificial microtubule depolymerization and by the use of reliable mitotic markers, we find NUMB differences in daughter cells to be reduced and restricted to cells with low NUMB expression and thus low signal over background. This bias fits the expected random distribution of simulated noise data, suggesting that the putative asymmetric inheritance of NUMB in HSCs could be merely technical noise. We conclude that functionally relevant asymmetric inheritance of NUMB and other factors in mitotic HSCs and other cells cannot be conclusively demonstrated using snapshot data and requires alternative approaches, such as continuous quantitative single‐cell analysis.
Patient‐related outcomes in Sjögren syndrome treated with stimulants of salivary secretion: Randomized clinical trial
Authors: da Mata António Duarte Sola Pereira , Amaral João Pedro de Almeida Rato , Thomson William Murray , Barcelos Filipe , Vaz Patto José , Pereira Ruben Miguel Nunes , Marques Duarte Nuno da Silva
Published: December 2019

Objectives

To investigate the impact of gustatory stimulants of salivary secretion (GSSS) on Sjögren's syndrome patients’ self‐perception of xerostomia, oral health‐related quality of life (OHRQoL) and salivary secretion.

Methods

A total of 110 Sjögren's syndrome patients were randomly allocated to be treated with either a malic acid lozenge or a citric acid mouthwash and then crossed over. Before and after the interventions, the Xerostomia Inventory 5 (SXI‐5‐PL) and the Oral Health Impact Profile (OHIP‐14‐PT) questionnaires (both in the Portuguese language) were administered to patients. Unstimulated, mechanical and gustatory‐stimulated salivary flows were determined. Repeated measures and between‐subject analyses were performed. Statistical significance was set at 5%.

Results

After the intervention and within each group, both GSSS elicited a reduction in the SXI‐5‐PL and OHIP‐14‐PT scores and an increase in salivary output, significant in the malic acid lozenge group. The malic acid treatment resulted in a greater effect size and percentage improvement than citric acid mouthwash. The malic acid lozenge also produced a significant greater salivary output than the citric acid rising solution.

Conclusions

In Sjögren's syndrome patients, lozenges containing malic acid increased saliva production and xerostomia relief, resulting in improved quality of life.
Epigallocatechin gallate inhibits leukotoxin release by Aggregatibacter actinomycetemcomitans by promoting association with the bacterial membrane
Authors: Chang En Hyung , Giaquinto Peter , Huang Joanne , Balashova Nataliya V. , Brown Angela C.
Published: December 2019

The oral pathogen, Aggregatibacter actinomycetemcomitans, produces a number of virulence factors, including a leukotoxin (LtxA), which specifically kills human white blood cells, to provide a colonization advantage to the bacterium. Strains of A. actinomycetemcomitans that produce more LtxA have been more closely linked to disease, indicating that this toxin plays a key role in pathogenesis of the bacterium. Disruption of the activity of LtxA thus represents a promising approach to reducing the pathogenicity of the bacterium. Catechins are polyphenolic molecules derived from plants, which have shown potent antibacterial and antitoxin activities. We have previously shown that galloylated catechins are able to prevent LtxA delivery to host cells by altering the toxin's secondary structure and preventing binding to cholesterol on the host cell membrane. Here, we have investigated how one particular galloylated catechin, epigallocatechin gallate (EGCg), affects A. actinomycetemcomitans growth and toxin secretion. Our results demonstrate that EGCg, at micromolar concentrations, inhibits A. actinomycetemcomitans growth, as has been reported for other bacterial species. At subinhibitory concentrations, EGCg promotes LtxA production, but the toxicity of the bacterial supernatant against human immune cells is reduced. The results of our biophysical studies indicate that this seemingly contradictory result is caused by an EGCg‐mediated enhancement of LtxA affinity for the bacterial cell surface. Together, these results demonstrate the potential of EGCg in the treatment of virulent A. actinomycetemcomitans infections.
Inhibition of endosomal trafficking by brefeldin A interferes with long‐distance interaction between chloroplasts and plasma membrane transporters
Authors: Bulychev Alexander A. , Foissner Ilse
Published: December 2019

The huge internodal cells of the characean green algae are a convenient model to study long‐range interactions between organelles via cytoplasmic streaming. It has been shown previously that photometabolites and reactive oxygen species released by illuminated chloroplasts are transmitted to remote shaded regions where they interfere with photosynthetic electron transport and the differential activity of plasma membrane transporters, and recent findings indicated the involvement of organelle trafficking pathways. In the present study, we applied pulse amplitude‐modulated microscopy and pH‐sensitive electrodes to study the effect of brefeldin A (BFA), an inhibitor of vesicle trafficking, on long‐distance interactions in Chara australis internodal cells. These data were compared with BFA‐induced changes in organelle number, size and distribution using fluorescent dyes and confocal laser scanning microscopy. We found that BFA completely and immediately inhibited endocytosis in internodal cells and induced the aggregation of organelles into BFA compartments within 30–120 min of treatment. The comparison with the physiological data suggests that the early response, the arrest of endocytosis, is related to the attenuation of differences in surface pH, whereas the longer lasting formation of BFA compartments is probably responsible for the acceleration of the cyclosis‐mediated interaction between chloroplasts. These data indicate that intracellular turnover of membrane material might be important for the circulation of electric currents between functionally distinct regions in illuminated characean internodes and that translational movement of metabolites is delayed by transient binding of the transported substances to organelles.
Public Sector Governance Reform and the Motivation of Street‐Level Bureaucrats in Developing Countries
Authors: Zarychta Alan , Grillos Tara , Andersson Krister P.
Published: December 2019

This article draws on health sector reform in Honduras to examine the mechanisms through which governance reforms shape the behavior of street‐level bureaucrats. It combines insights from behavioral public administration with original data from lab‐in‐the‐field workshops conducted with more than 200 bureaucrats to assess the relationship between decentralization and motivation. Findings show strong evidence that motivation, measured as self‐sacrifice, is higher among bureaucrats in decentralized municipalities compared with bureaucrats in comparable centrally administered municipalities. Increased motivation is most pronounced in decentralized systems led by nongovernmental organizations compared with those led by municipal governments or associations. Additionally, the evidence suggests that higher motivation is related to changes in the composition of staff rather than socialization or changes among existing staff. Overall, this research helps move beyond indiscriminate calls for decentralization by highlighting the interplay between reform design and bureaucratic behavior, as well as the limitations of governance reforms in motivating more experienced bureaucrats.
A Novel Sampling Strategy for Surveying High Net‐Worth Individuals—A Pretest Application Using the Socio‐Economic Panel
Authors: Schröder Carsten , Bartels Charlotte , Grabka Markus M. , König Johannes , Kroh Martin , Siegers Rainer
Published: December 2019

High‐wealth individuals are typically underrepresented or completely missing in population surveys. The lack of comprehensive national registers on high‐wealth individuals in many countries challenged previous attempts to remedy this under‐representation. In a novel research design, we draw on public data on the shareholding structures of companies as a sampling frame. Our design builds on the empirical regularity that high‐wealth individuals are likely to hold at least part of their assets in the form of shareholdings. Based on data from over 270 million companies worldwide, we select all individuals who are both German residents and registered shareholders of companies. In a pretest, we interviewed 124 households from a gross sample of 2,000 anchor persons. Our analysis shows that values of shareholdings from register data highly correlate with individual ranks in the wealth distribution, that the quality of personal information, particularly the residential address, is sufficiently high for subsequent interviewing, and that the approach can fill a major data and research gap in the study of high‐wealth individuals.
A genetically validated approach for detecting inorganic polyphosphates in plants
Authors: Zhu Jinsheng , Loubéry Sylvain , Broger Larissa , Zhang Youjun , Lorenzo‐Orts Laura , Utz‐Pugin Anne , Fernie Alisdair R. , Young‐Tae Chang , Hothorn Michael
Published: December 2019

Inorganic polyphosphates (polyPs) are linear polymers of orthophosphate units linked by phosphoanhydride bonds. Polyphosphates represent important stores of phosphate and energy, and are abundant in many pro‐ and eukaryotic organisms. In plants, the existence of polyPs has been established using microscopy and biochemical extraction methods that are now known to produce artifacts. Here we use a polyP‐specific dye and a polyP‐binding domain to detect polyPs in plant and algal cells. To develop the staining protocol, we induced polyP granules in Nicotiana benthamiana and Arabidopsis cells by heterologous expression of Escherichia coli polyphosphate kinase 1 (PPK1). Over‐expression of PPK1 but not of a catalytically impaired version of the enzyme leads to severe growth phenotypes, suggesting that ATP‐dependent synthesis and accumulation of polyPs in the plant cytosol is toxic. We next crossed stable PPK1‐expressing Arabidopsis lines with plants expressing the polyP‐binding domain of E. coli exopolyphosphatase (PPX1c), which co‐localized with PPK1‐generated polyP granules. These granules were stained by the polyP‐specific dye JC‐D7 and appeared as electron‐dense structures in transmission electron microscopy sections. Using the polyP staining protocol derived from these experiments, we screened for polyP stores in different organs and tissues of both mono‐ and dicotyledonous plants. While we could not detect polyP granules in higher plants, we could visualize the polyP‐rich acidocalcisomes in the green alga Chlamydomonas reinhardtii.
MECHANICAL PROPERTIES OF BREWERS DRIED GRAIN ASH-HYDRATED LIME IN CONCRETE
Authors: L.Z Tuleun, , A.A. Jimoh, , J. Wasiu,
Published: December 2019

Ordinary Portland cement (OPC), the world most used binder in concrete production is adjudged a non - environmental friendly material due to the CO2 gas that is emitted into the atmosphere during its production process. Also, with the future generation in mind, limestone resource needs to be adequately preserved and managed. Previous studies on the search for alternative binders had centred mostly on the use of Agro - waste pozzolans in concrete, with little emphasis on the use of the pozzolans with additives that may further enhance reaction in concrete. Hence, this paper explores the possibility of using OPC with brewers dried grain ash-hydrated lime (BDGA-HL) in concrete. Prior to testing for initial and final setting time, compressive, flexural and tensile strength; cubes, beams and cylindrical specimens containing BDGA-HL at 5, 10, 15 and 20 % cement replacement were cast (in a ratio of 1:1.5:3.2 and w/c of 0.61) and cured in water for 7, 14, 28, and 56 days. Based on the findings, a decrease in setting time of the paste was noticed when OPC was partially replaced with BDGA-HL. Also observed was an improvement in flexural and tensile strength up to 10 %; while the maximum compressive strength was attained at 15 %. The results obtained for BDGA-HL concrete were higher than that of plain concrete. It was concluded that BDGA-HL has an excellent pozzolanic potentials improving the properties of concrete
Reviewer Acknowledgements
Authors: Smith Robert
Published: December 2019

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 6, Number 5Ali Kızılet, Marmara University, TurkeyAntónio Calha, Polytechnic Institute of Portalegre, PortugalCagla Atmaca, Pamukkale University, TurkeyCarmen Pérez-Sabater, Universitat Poltècnica de València, SpainElena Jerves, University of Cuenca, EcuadorErcan Polat, TurkeyErickzon Astorga, The Metropolitan University of Educational Sciences, ChileFatih Karahüseyinoğlu, Fırat University, TurkeyFatih Yazici, Gaziosmanpaşa University, Turkeyİbrahim Yaşar Kazu, Firat University, TurkeyJon S. Turner, Missouri State University, USAKatya De Giovanni, University of Malta, MaltaLaima Kyburiene, Kaunas University of Applied Sciences, LithuaniaLaura Bruno, The College of New Jersey, USALinda J. Rappel, Yorkville University/University of Calgary, CanadaLisa Marie Portugal, Grand Canyon University, USALorna T. Enerva, Polytechnic University of the Philippines, PhilippinesMassimiliano Barattucci, Ecampus University, ItalyMeral Seker, Alanya Alaaddin Keykubat University, TurkeyMin Gui, Wuhan University, ChinaMurat Kul, TurkeyMustafa Çakır, Marmara Üniversity, TurkeyNicole Celestine, The University of Western Australia, AustraliaOzgur Demirtas, Inonu University, TurkeyPuneet S. Gill, Texas A&M International University, USARichard H. Martin, Mercer University, USASadia Batool, Preston University Islamabad, PakistanSamad Mirza Suzani, Islamic Azad University, IranSandro Sehic, Oneida BOCES, USASelloane Pitikoe, University of Kwazulu-Natal, South AfricaSenem Seda Şahenk Erkan, Marmara University, TurkeySisi Chen, American University of Health Sciences, USAStamatis Papadakis, University of Crete, GreeceTercan Yildirim, Ahi Evran University, TurkeyYalçın Dilekli, Aksaray University, Turkey Robert SmithEditorial AssistantOn behalf of,The Editorial Board of Journal of Education and Training StudiesRedfame Publishing9450 SW Gemini Dr. #99416Beaverton, OR 97008, USAURL: http://jets.redfame.com
A Miniature Robotic-Assisted Tool for Large Area Endomicroscopy Scanning
Authors: Wang Haibo , Kong Derui , Zuo Siyang
Published: December 2019

Recent developments in probe-based optical imaging tools such as confocal endomicroscopy have been demonstrated to be powerful techniques that can provide high-resolution in vivo morphological images at cellular and subcellular levels. Such tools may aid in real-time assessment of cancerous tissue and can also be used for intraoperative surgical guidance. However, it is a challenge to scan over a large area due to the small field-of-view and the difficulties associated with manually manipulating the probe. In this paper, a hand-held miniature scanning device for controlled, large area imaging is proposed. The device can scan target surfaces automatically. A passive linear mechanism is used to maintain good probe–tissue contacts. The results demonstrated that large area mosaics up to 31.4 mm2 can be obtained. The experimental results for ex vivo human thyroid gland tissue have shown the potential of the device for improving the prospects of intraoperative tissue identification and margin assessment.
Synthesis of Planar Compliances With Mechanisms Having Six Compliant Components: Geometric Approach
Authors: Huang Shuguang , Schimmels Joseph M.
Published: December 2019

In this paper, the synthesis of any planar compliance with a six-component compliant mechanism is addressed. The mechanisms studied are either serial mechanisms with six elastic joints or parallel mechanisms with six springs. For each type of mechanism, conditions on the mechanism configurations that must be satisfied to realize a given compliance are developed. The geometric significance of each condition is identified and graphically represented. Geometric construction-based synthesis procedures for both types of mechanism are developed. These procedures allow one to select each elastic component from a restricted space based on its geometry.
Nonlinear Stiffness Analysis of Spring-Loaded Inverted Slider Crank Mechanisms With a Unified Model
Authors: Li Zhongyi , Bai Shaoping , Chen Weihai , Zhang Jianbin
Published: December 2019

A mechanism with lumped-compliance can be constructed by mounting springs at joints of an inverted slider crank mechanism. Different mounting schemes bring change in the stiffness performance. In this paper, a unified stiffness model is developed for a comprehensive analysis of the stiffness performance for mechanisms constructed with different spring mounting schemes. With the model, stiffness behaviors of spring-loaded inverted slider crank mechanisms are analyzed. Influences of each individual spring on the overall performance are characterized. The unified stiffness model allows designing mechanisms for a desired stiffness performance, such as constant-torque mechanism and variable stiffness mechanism, both being illustrated with a design example and experiments.
Gravity Compensation Design of Planar Articulated Robotic Arms Using the Gear-Spring Modules
Authors: Nguyen Vu Linh , Lin Chyi-Yeu , Kuo Chin-Hsing
Published: December 2019

This paper presents a design concept for gravity compensation of planar articulated robotic arms using a series of gear-slider mechanisms with springs. The spring-attached gear-slider mechanism has one degree-of-freedom (DOF) of motion, which can serve as a gear-spring module (GSM) to be installed onto the robot joints for leveraging the gravitational energy of the robot arm. The proposing GSM-based design is featured by its structure compactness, less assemblage effort, ease of modularization, and high performance for gravity compensation of articulated robotic manipulators. As a key part of the design, the stiffness of the spring in the GSM can be determined through either a design optimization or an analytical approximation to perfect balancing. The analyses on several 1-, 2-, and 3-DOF GSM-based robot arms illustrate that the analytical approximation to perfect balancing can reach nearly the same performance as provided through the design optimization. The power loss due to the gear contact is considered when evaluating the gravity compensation performance. A formula for spring stiffness correction is suggested for taking the power loss into account. An experimental study on a one-DOF GSM-based robot arm was performed, which shows that a power reduction rate of 86.5% is attained by the actuation motor when the GSM is installed on the robot arm.
Improved Model for Conical Dielectric Elastomer Actuators With Fewer Electrical Connections
Authors: Medina Hector , Farmer Carson W.
Published: December 2019

Dielectric elastomers (DEs) exhibit remarkable properties that make them stand out among other electroactive polymers. Various types of actuators based on DEs have been used in applications that include artificial muscles, Braille displays, and robotic joints. In particular, conical dielectric elastomer actuators (CDEAs) are very attractive due to their multiple degrees of freedom (DOF) and easiness of construction. In this study, an energy method is used to derive an improved mathematical model for a double-cone dielectric elastomer actuator (DCDEA) capable of predicting horizontal and rotational displacements. To create the model, a new variable is introduced into the equations, the azimuth angle. In addition, a new pattern of electrodes is proposed as a method for achieving five DOF using only half of the electrode connections of traditional DCDEAs. Experimental tests are carried out and used to validate the proposed model. Results show very close agreement. A limiting aspect of the proposed model is that it relies on two experimental correction coefficients. Nonetheless, the model derived provides a means to more accurately implement automatic control to robotic systems that use DCDEAs (work in progress).
Theoretical and Experimental Study and Design Method of Blade Height of a Rotational-Flow Suction Unit in a Wall-Climbing Robot
Authors: Chen Ningning , Shi Kaige , Li Xin
Published: December 2019

A wall-climbing robot that uses a rotational-flow suction unit to be non-contact-absorbed onto walls can climb rough walls and overstep obstacles. In the rotational-flow suction unit, the air driven by the blades rotates at a high speed within a chamber, thereby creating and maintaining a negative pressure distribution. This study is focused on the modeling and design of the blade height. First, a theoretical model of the rotation flow, containing two important parameters (i.e., blade height Hb and clearance h), was established and verified experimentally. Furthermore, the computational fluid dynamics (CFD) method was applied to illustrate the secondary flow relative to the blades, revealing that it gives rise to a nonlinear velocity distribution. It was found that an increase in the blade height greatly improves the F–h characteristics; in addition, the relationship between the power consumption and suction force (E˙−F curve) is mainly determined by the clearance h instead of the blade height Hb. Based on these findings, we propose a design method for determining the suitable blade height. According to the characteristic load curves of the suction units (i.e., the T–ω curves) and the motor characteristics, suitable blades can be selected to match the motor operation (i.e., nominal operating state).
Analysis and Control of an Actuation-Redundant Parallel Mechanism Requiring Synchronization
Authors: Xi Fengfeng (Jeff) , Moosavian Amin , Campos Gabriel H. , Choudhuri Upasana (Sana) , Sun Cong Zhu (John) , Buchkazanian Raffi
Published: December 2019

Presented in this paper is a method for analysis and control of an actuation-redundant parallel mechanism requiring synchronization. The said mechanism is made up of two branches that are connected to drive a common end-effector with only one degree-of-freedom of motion. The two actuators must share the load exerted on the common end-effector during motion. The underlying problem is to synchronize the motion of the two actuators while balancing the forces on them so that the entire mechanism can move smoothly under the applied load on the end-effector. Due to the space limitation, the two branches are geometrically different leading to opposite force profiles for the two actuators. The proposed method combines the mechanism kinematics with force analysis. First, a closed-form solution is derived that relates the actuator strokes to the rotation angle of the end-effector. Second, a velocity relationship is obtained to relate the actuator velocities to the angular velocity of the end-effector. Third, a force relationship is established relating the actuator loads to the external load. Fourth, a control strategy is designed to synchronize the motion of the two actuators while maintaining the force balance between them to avoid the problem of motion mismatching and force fighting that could lead to the failure of the mechanism. A prototype was built and tested with the proposed method, which is also presented in this paper.
Generalized Spiral Spring: A Bioinspired Tunable Stiffness Mechanism for Linear Response With High Resolution
Authors: Qaiser Zeeshan , Johnson Shane
Published: December 2019

Compliant mechanisms are typically designed for varying stiffness from nearly zero to rigid. However, targeted design for fine-tuning within an application's sensitive range of stiffness remains more desirable for practical implementation in accurate loading or positioning systems. To achieve various competing objectives, a “generalized spiral spring” (GSS) is proposed which achieves small size and other objectives by using a reduced number of parameters as provided by the spiral shape description of the components. An analytical model based on virtual work and curved beam theory is developed for accurate prediction of the stiffness. Moreover, finite element (FE) models are also developed for verification of the proposed designs. Multiobjective design optimization (MDO) is conducted to maximize the linearity in the stiffness versus control parameter (CP) response and improve resolution. The proposed analytical model is validated experimentally and computationally. This approach may be used to achieve finesse by accurate positioning with force control for industrial robots and elegant prostheses.
A Novel Style Design of a Permanent-Magnetic Adsorption Mechanism for a Wall-Climbing Robot
Authors: Fan Jizhuang , Xu Tian , Fang Qianqian , Zhao Jie , Zhu Yanhe
Published: December 2019

Magnetic adsorption mechanisms are widely used for wall-climbing robots to manipulate a locomotive on the surface of a magnetic conducting metal. However, the reported magnetic adsorption mechanisms are subject to the problems such as the lack of adsorption capability, the weakness of kinematic performance, and the overwhelming detaching force. To solve the problems, a novel style of a permanent-magnetic adsorption mechanism using an electromagnetic method and internal force compensation principle is detailed in this work. Specifically, a permanent magnet, an electromagnet, and a nonlinear spring are configurated to achieve a reliable adsorption function by using the minimal detaching force. Following that, the results obtained from both the finite element analysis and the experiments carried out by using a prototype demonstrated its effectiveness. It does not only have a rapid and controllable adsorption-detachment capacity in reference to the magnetic conducting surface but also has low power consumption, large adsorption force, and reliable and safe performance.
A Study on the Autoignition Characteristics of Gasoline-Biodiesel Blended Fuel Using a Rapid Compression Expansion Machine
Authors: Jwa Kyeonghun , Lee JinWoo , Lim Ocktaeck
Published: December 2019

In this study, the problem of GCI method at low intake air temperature was solved by using gasoline-biodiesel blended fuel. Autoignition characteristics of gasoline-biodiesel blended fuel was analyzed using a rapid compression expansion machine. Gasoline-biodiesel blended fuel was mixed 20% of biodiesel with gasoline volume and spontaneous ignition characteristics were analyzed according to fuel injection timing and compression ratio. Firstly, this study investigated spontaneous ignition characteristics of gasoline-biodiesel blended fuel according to the injection timing. A compression ratio was fixed at 12, and the injection timing was delayed from −49° CA ATDC to 0° CA ATDC. The ignition delay time of the mixed fuel was decreased and the IMEP was increased as the injection timing was delayed until −10° CA ATDC. However, the ignition delay time and IMEP subtly changed when the injecting was near TDC. To investigate the auto-ignition characteristics of the gasoline-biodiesel blended fuel according to the compression ratio, the experiment tested at 10, 12, 14, and 16. At that time, the injection timing was set to −33° CA ATDC, −20° CA ATDC, −10° CA ATDC, and −0° CA ATDC. The ignition delay tended to be shorter as the injection timing was delayed at all compression ratios but IMEP calculated at CR10, 16 is good at only specific injection periods. At the compression ratios 12 and 14, the most extensive range of IMEP results were obtained.
Mathematical Modeling of Electrical Heater Assisted CO Conversion in an Oxidation Catalyst at Low Loads and Cold Start Conditions
Authors: Nair Sreeharsh , Mohapatra Priyabrata , Mittal Mayank
Published: December 2019

The emission regulations for internal combustion engines are becoming more and more stringent with the aim to reduce the pollutants emitted to the atmosphere. One of the most efficient means to meet upcoming stringent emission regulations is by reducing the pollutants emitted during the warm-up time and at low-load operating conditions by using an oxidation catalyst. In the present work, a 1-D mathematical model of an electrical heater assisted oxidation catalyst has been developed to study the effect of heater on CO conversion at low operating loads and during cold start conditions. The study has been conducted considering different power levels, heating durations (continuous and temporary) and heating volumes, and it promises to be helpful in tackling the problem. The results revealed that heater assistance to the oxidation catalyst improved the light-off performance, and temporary heating was found to be as effective as continuous heating in reducing the CO emission. Moreover, an indication parameter (light-off time reduction per unit power) has been developed, which can be used to optimize the power requirement of the heater.
Diesel Engine Acoustic Diagnostics With Machine Learning During Various Degradation Modes
Authors: Moore Patrick , Prak Dianne Luning , Hamilton Len , Cowart Jim
Published: December 2019

A diesel engine electrical generator set (‘gen-set’) was instrumented with an in-cylinder pressure indicating system as well as an acoustic emission sensor near the engine. Air filter clogging, rocker arm gap and fuel cetane changes were applied during which engine combustion and acoustic data were collected. Fast Fourier Transforms (FFTs) were analyzed on the acoustic data. FFT data were then applied to categorical supervised machine learning neural network analysis with MATLAB based tools. The detection of the various degradation modes was audibly determined with correlation coefficients greater than 99% on test data. Next, an unsupervised machine learning Self Organizing Map (SOM) was produced during normal-baseline operation of the engine.

Application of the degraded mode engine sound data from operation with the various faults were then applied to the normal-baseline SOM. The quantization error of the various degraded engine data showed clear statistical differentiation from the normal operation data map. This unsupervised SOM based approach does not know the engine degradation behavior in advance, yet shows promise as a method to monitor and detect changing engine operation. Companion in-cylinder combustion data shows how changing combustion characteristics result in emitted sound differences.
Combustion and Greenhouse Gas Emissions of a Natural Gas-Diesel Dual Fuel Engine at Low and High Load Conditions
Authors: Guo Hongsheng , Liko Brian , Littlejohns Jennifer
Published: December 2019

The Paris agreement is exerting pressure on industries that generate significant greenhouse gas (GHG) emissions, such as transportation. Electrification can help reduce GHG emissions from light duty vehicles, but it is unfeasible for heavy duty vehicles that are predominately powered by diesel engines. Fuel switching from diesel to low carbon fuels is a more practical way helping reduce GHG emissions from heavy duty vehicles. Natural gas and renewable natural gas are low carbon or renewable fuels that generate much less carbon dioxide (CO2) emissions than diesel during combustion. Natural gas/renewable natural gas – diesel dual fuel combustion is an efficient way to replace diesel by natural gas/renewable natural gas in heavy duty diesel engines.

This paper reports an experimental investigation on combustion and GHG emissions of a heavy duty natural gas – diesel dual fuel engine at different load/speed conditions. The variation in the effect of natural gas fraction on engine performance with changing engine load was compared and analyzed. Nitrous oxide (N2O), nitrogen oxides (NOx), methane (CH4) and CO2 emissions were experimentally investigated and analyzed. The results revealed that the effect of natural gas fraction on engine performance changed with varying engine load and speed condition. N2O emissions from a dual fuel engine changed with increasing natural gas fraction, but the effect of N2O emissions on overall GHG emissions was not significant. However, CH4 emissions contributed significantly to the overall GHG emissions in a dual fuel engine, especially at low load conditions.