bluuebunny/crossref_metadata_2025 huggingface dataset:
Documentation in the neonatal unit: The support given to parents and their participation in their baby's care
Authors: Shaw Chloe , Suonpera Emmi , Gallagher Katie , Aladangady Narendra , Stokoe Elizabeth , Marlow Neil
Published: November 2018

Aims

The aim of this study was to explore how often the participation of parents in their infants’ care and professionals’ support for parents was documented in the clinical records and to determine how such participation and support were documented.

Background

Comprehensive documentation can facilitate collaboration between parents and healthcare professionals, supporting family‐centred care, yet little is known about how this is reflected in practice.

Design

A prospective, mixed methods approach was used to analyse the clinical records of newborns.

Methods

The study was carried out in a large tertiary Neonatal Unit in the United Kingdom, from 2013 ‐ 2014. We analysed the clinical records of 24 critically ill newborns using content analysis and thematic analysis, enabling us to determine the frequency of documented support and participation and how support and participation were documented.

Results

We identified four categories of support in the clinical records: “emotional”, “spiritual”, “social” and “practical support”. We also identified instances where parents were encouraged to participate in their infant's care. Frequency differences in the documentation of support between infants facing a redirection of care decision and infants receiving active treatment were found. Two organisational themes were identified: “task focused documentation” and “minimal documentation of parental role”. These were grouped together under the global theme “professional accountability”. The perspectives and experiences of parents were minimally documented throughout.

Conclusion

Documentation of support towards parents and parents’ participation in their infants’ care was limited in terms of frequency and content. Encouraging regular, detailed documentation of these aspects of care may facilitate family‐centred care.
Enriching feedback in audience response systems: Analysis and implications of objective and subjective metrics on students' performance and attitudes
Authors: Papadopoulos Pantelis M. , Natsis Antonis , Obwegeser Nikolaus , Weinberger Armin
Published: November 2018

The aim of the present study (n = 113) was to examine how (objective and subjective) information on peers' preparation, confidence, and past performance can support students in answering correctly in audience response systems (aka clickers). The result analysis shows that in the “challenging” questions, in which answers diverged, students who received additional information about peers' self‐reported preparation and/or confidence outperformed students who were only given the objective percentage with or without past performance feedback. In addition, students expressed a positive attitude towards the activity, commenting its usefulness in better understanding course material and identifying misconceptions.
Fasting triglycerides and glucose index is more suitable for the identification of metabolically unhealthy individuals in the Chinese adult population: A nationwide study
Authors: Yu Xinwen , Wang Li , Zhang Wencheng , Ming Jie , Jia Aihua , Xu Shaoyong , Li Qiaoyue , Ji Qiuhe
Published: November 2018

Aims/Introduction

Metabolic unhealth can be defined by the components of metabolic syndrome, which is closely connected to insulin resistance. We aimed to determine a simple index to identify metabolic unhealth in the Chinese adult population.

Materials and Methods

A total of 30,291 individuals were screened from the China National Diabetes and Metabolic Disorders Study carried out from June 2007 to May 2008. Metabolic unhealth was defined using components of metabolic syndrome, except waist circumference. We compared the three surrogate indices of insulin resistance: the product of fasting triglycerides and glucose (TyG), triglycerides divided by high‐density lipoprotein cholesterol and the metabolic score for insulin resistance for the evaluation of metabolic status.

Results

All indices had high sensitivity and specificity for the identification of metabolic unhealth, especially the TyG index with an area under the curve of 0.863 for men and 0.867 for women. Participants were divided into subgroups for further analysis. The TyG index also showed high diagnostic values, especially for younger individuals and men with normal waist circumference. Sex‐specific cut‐offs for three indices were also used to define metabolic unhealth. The TyG index showed the highest agreement with κ values of 0.603 and 0.605 for men and women between the components of metabolic syndrome and three indices.

Conclusions

We propose that the TyG index, just read in one blood laboratory test report, is simpler and more suitable for the identification of metabolically unhealthy individuals as well as who have high risk of cardiometabolic diseases of the Chinese adult population.
A portable detection method for organophosphorus and carbamates pesticide residues based on multilayer paper chip
Authors: Yang Ning , Wang Pan , Xue Chun‐Yang , Sun Jun , Mao Han‐Ping , Oppong Paul Kwabena
Published: November 2018

Organophosphorus and carbamates pesticide residues detection is one of significance in vegetables and fruits production. However, an effective directly detection method without any auxiliary has not been reported yet. Herein, we proposed a multilayer paper chip, including injection layer, heating layer, conduction layer, fixed enzyme layer, fixed indophenol acetate layer, and color layer, for pesticide residue of organophosphorus and carbamates detection based on the principles of enzyme inhibition reaction and heat generation inside. It's the first time for paper‐based chip to include an inside built‐in heating layer, which can ensure the reaction process with enzyme is always at the optimum temperature. Without any external instrument, we can determine whether the pesticide exceeds the standard according to the reaction color. Besides, we can also make quantitative detection of pesticide with external spectrometer detection system. The overall detection process runs automatically, then relatively accurate test results can be acquired. Under the optimum condition, a good linear correlation for dipterex concentrations over the range from 0.05 to 0.5 mg/L was obtained by quantitative detection, which can reach a detection limit (LOD) of 0.0406 mg/L. Besides, it also showed satisfactory reproducibility, specificity, and stability. Therefore, it is suitable for the instant detection technique.

Practical applications

This article provides a method which is used to detect organophosphorus and carbamates pesticide residues existing in vegetables and fruits production. The detection limit is 0.0406 mg/L and it is lower than national standards. The detection reproducibility is acceptable. This method is energy‐saving and environment friendly. In this article, multilayer paper chip that includes enzyme inhibition reaction, color reaction and exothermic reaction was proposed. The heating layer in multilayer paper chip relies on the principle of chemical heat production and needs only a little water, which is very simple and easy. Under the whole process of detection without manual intervention, the testing result from the paper chip not only can be distinguished by eyes, but also can be detected precisely by simple detection device, which provide a basis for development of portable pesticide detector.
FIB‐SEM imaging properties of Drosophila melanogaster tissues embedded in Lowicryl HM20
Authors: PORRATI F. , GREWE D. , SEYBERT A. , FRANGAKIS A.S. , ELTSOV M.
Published: November 2018

Lowicryl resins enable processing of biological material for electron microscopy at the lowest temperatures compatible with resin embedding. When combined with high‐pressure freezing and freeze‐substitution, Lowicryl embedding supports preservation of fine structural details and fluorescent markers. Here, we analysed the applicability of Lowicryl HM20 embedding for focused ion beam (FIB) scanning electron microscopy (SEM) tomography of Drosophila melanogaster embryonic and larval model systems. We show that the freeze‐substitution with per‐mill concentrations of uranyl acetate provided sufficient contrast and an image quality of SEM imaging in the range of similar samples analysed by transmission electron microscopy (TEM). Preservation of genetically encoded fluorescent proteins allowed correlative localization of regions of interest (ROI) within the embedded tissue block. TEM on sections cut from the block face enabled evaluation of structural preservation to allow ROI ranking and thus targeted, time‐efficient FIB‐SEM tomography data collection. The versatility of Lowicryl embedding opens new perspectives for designing hybrid SEM‐TEM workflows to comprehensively analyse biological structures.

Lay Description

Focused ion beam scanning electron microscopy is becoming a widely used technique for the three‐dimensional analysis of biological samples at fine structural details beyond levels feasible for light microscopy. To withstand the abrasion of material by the ion beam and the imaging by the scanning electron beam, biological samples have to be embedded into resins, most commonly these are very dense epoxy‐based plastics. However, dense resins generate electron scattering which interferes with the signal from the biological specimen. Furthermore, to improve the imaging contrast, epoxy embedding requires chemical treatments with e.g. heavy metals, which deteriorate the ultrastructure of the biological specimen. In this study we explored the applicability of an electron lucent resin, Lowicryl HM 20, for focused ion beam scanning electron microscopy. The Lowicryl embedding workflow operates at milder chemical treatments and lower temperatures, thus preserving the sub‐cellular and sub‐organellar organization, as well as fluorescent markers visible by light microscopy. Here we show that focus ion beam scanning electron microscopy of Lowicryl‐embedded fruit flies tissues provides reliable imaging revealing fine structural details. Our workflow benefited from use of transmission electron microscopy for the quality control of the ultrastructural preservation and fluorescent light microscopy for localization of regions of interest. The versatility of Lowicryl embedding opens up new perspectives for designing hybrid workflows combining fluorescent light, scanning, and transmission electron microscopy techniques to comprehensively analyze biological structures.
Bacterial endocarditis and increased cardiac troponin I levels in a brown howler monkey (Alouatta guariba clamitans) with an interventricular septal defect
Authors: Zafalon‐Silva Bruna , Soares Frederico Aécio Carvalho , Pavarini Saulo Petinatti , Goulart Miúriel de Aquino , Snel Gustavo Geraldo Medina , González Félix Hilário Diaz , Vaz Dayana Bittencourt , Lopes Bruna Correa , Oliveira Moira Ansolch da Silva , Alievi Marcelo Meller
Published: November 2018

A brown howler monkey (Alouatta guariba clamitans) was presented with lethargy, hyporexia, cough and heart murmur. The complementary tests and necropsy revealed pleuropneumonia, bacterial endocarditis and interventricular septal defect. To the best of our knowledge, this is the first report of increased cardiac troponin I levels in this species.
Pre‐ and postnatal development of the otic ganglion in humans
Authors: Bandke Dave , Ebauer Konstantin , Ebauer Alexander , Weis Serge
Published: November 2018

Only a few papers exist dealing with the development and aging of the autonomic nervous system – and even rarer are studies that investigated the otic ganglion. Using a special trepan, we removed and investigated 172 samples from 86 corpses, ranging from 20 weeks of gestational age (GA) to 95 years of age. The aim of the study was to measure different morphometric parameters of the ganglionic neurons in order to study age‐related changes from early development until old age. Fetuses show the highest numerical density of neurons. Then, in the first years of life, a rapid growth of the cytoplasm takes place, which is the main reason for the neuronal growth and the increase of the general size of the otic ganglion at this age. Also, the number of satellite cells increases till puberty. In adults, the parameters are relatively stable over decades and decrease slowly, in contrast to the steep increase in the first years of life. Moreover, neuronal degeneration, storage of pigments, neuro‐axonal dystrophy, and lymphocytic infiltrates increase with age.
Resveratrol glucuronidation in vitro: potential implications of inhibition by probenecid
Authors: Matin Bahar , Sherbini Ahmad A , Alam Novera , Harmatz Jerold S , Greenblatt David J
Published: November 2018

Objectives

Resveratrol is a naturally occurring antioxidant with therapeutic potential in prevention and treatment of neoplastic disease and other human disorders. However, net clearance of resveratrol in humans is very high, mainly due to glucuronide conjugation. This leads to extensive presystemic extraction and low plasma concentrations after oral dosage. The present study evaluated the effect of probenecid, an inhibitor of glucuronide conjugation, on resveratrol metabolism in vitro.

Methods

Biotransformation of resveratrol to its 3-O-glucuronide and 4′-O-glucuronide conjugates was studied in vitro using human liver microsomal preparations. The mechanism and inhibitory potency of probenecid were evaluated based on a mixed competitive-noncompetitive inhibition model.

Key findings

Probenecid inhibition of resveratrol 3-O-glucuronidation was predominantly noncompetitive, with an inhibition constant (Ki) averaging 3.1 mm.

Conclusions

The ratio of in vivo maximum concentration of probenecid [I] during usual clinical use to the in vitro Ki value ([I]/Ki) exceeds the boundary value of 0.1, used by regulatory agencies to identify the possibility of clinical drug interactions. This finding, together with the known property of probenecid as an inhibitor of glucuronide conjugation in humans, suggests that probenecid could serve as a pharmacokinetic boosting agent to enhance systemic exposure to resveratrol in humans.
Probing molecular and isotopic features of meteoritic insoluble organic matter by solid‐state nuclear magnetic resonance spectroscopy with sub‐milligram sample
Authors: Pandey M. K. , Nishiyama Y. , Tekely P.
Published: November 2018

We recorded one‐ and two‐dimensional solid‐state nuclear magnetic resonance spectra of meteoric insoluble organic matter with unprecedented sensitivity and resolution permitting us to reveal unambiguous spectroscopic fingerprints relevant to its molecular and isotopic features. Two‐dimensional 1H‐1H and 1H‐13C correlation experiments have unveiled the spatial proximity between aliphatic and aromatic groups proving a highly branched character of a rigid macromolecular network composed of short aliphatic chains linking together small aromatic units. One‐dimensional 2H and two‐dimensional 1H‐2H correlation spectroscopy delivered evidence of significant reduction in the deuterium enrichment of aromatic species relevant to interstellar processes, proto‐planetary disk chemistry, and to determining the origin of the meteoritic insoluble organic matter. The experimental approach developed in this work opens new perspectives for systematic and nondestructive analysis at the molecular level of meteoritic insoluble organic matter even with a very small amount of sample from some particularly rare chondrites.
Evidence supporting dual‐process theory of medical diagnosis: a functional near‐infrared spectroscopy study
Authors: Rotgans Jerome I , Schmidt Henk G , Rosby Lucy V , Tan Gerald J S , Mamede Silvia , Zwaan Laura , Low‐Beer Naomi
Published: November 2018

Purpose

The objective of this study was to determine the extent to which the dual‐process theory of medical diagnosis enjoys neuroscientific support. To that end, the study explored whether neurological correlates of system‐2 thinking could be located in the brain. It was hypothesised that system‐2 thinking could be observed as the activation of the prefrontal cortex.

Method

An experimental paradigm was applied that consisted of a learning and a test phase. During the learning phase, 22 medical students were trained in diagnosing chest X‐rays. Four of these eight cases were presented repeatedly, to develop a high level of expertise for these cases. During the test phase, all eight cases were presented and the participants’ prefrontal cortex was scanned using functional near‐infrared spectroscopy. Response time and diagnostic accuracy were recorded as behavioural indicators.

Results

The results revealed that participants’ diagnostic accuracy in the test phase was significantly higher for the trained cases as compared with the untrained cases (F[1, 21] = 138.80, p < 0.001, η2 = 0.87). Also, their response time was significantly shorter for these cases (F[1, 21] = 18.12, p < 0.001, η2 = 0.46). Finally, the results revealed that only for the untrained cases, could a significant activation of the anterolateral prefrontal cortex be observed (F[1, 21] = 21.00, p < 0.01, η2 = 0.34).

Conclusion

The fact that only untrained cases triggered higher levels of blood oxygenation in the prefrontal cortex is an indication that system‐2 thinking is a cognitive process distinct from system 1. Implications of these findings for the validity of the dual‐process theory are discussed.
Novel mutations identified in patients with tooth agenesis by whole‐exome sequencing
Authors: Zhao Kai , Lian Meifei , Zou Duohong , Huang Wei , Zhou Wenjie , Shen Yihan , Wang Feng , Wu Yiqun
Published: November 2018

Objectives

To identify potentially pathogenic mutations for tooth agenesis by whole‐exome sequencing.

Subjects and Methods

Ten Chinese families including five families with ectodermal dysplasia (syndromic tooth agenesis) and five families with selective tooth agenesis were included. Whole‐exome sequencing was performed using genomic DNA. Potentially pathogenic mutations were identified after data filtering and screening. The pathogenicity of novel variants was investigated by segregation analysis, in silico analysis, and functional studies.

Results

One novel mutation (c.441_442insACTCT) and three reported mutations (c.252delT, c.463C>T, and c.1013C>T) in EDA were identified in families with ectodermal dysplasia. The novel EDA mutation was co‐segregated with phenotype. A functional study revealed that NF‐κB activation was compromised by the identified mutations. The secretion of active EDA was also compromised detection by western blotting. Novel Wnt10A mutations (c.521T>C and c.653T>G) and EVC2 mutation (c.1472C>T) were identified in families with selective tooth agenesis. The Wnt10A c.521T>C mutation and the EVC2 c.1472C>T mutation were considered as pathogenic for affecting highly conserved amino acids, co‐segregated with phenotype and predicted to be disease‐causing by SIFT and PolyPhen2. Moreover, several reported mutations in PAX9, Wnt10A, and FGFR3 were also detected.

Conclusions

Our study expanded our knowledge on tooth agenesis spectrum by identifying novel variants.
A global review of the ecosystem services provided by bivalve aquaculture
Authors: van der Schatte Olivier Andrew , Jones Laurence , Vay Lewis Le , Christie Michael , Wilson James , Malham Shelagh K.
Published: November 2018

Bivalve shellfish aquaculture provides many benefits to society, beyond their traditional market value. This study collates the evidence available on the provisioning, regulating and cultural ecosystem services provided by the bivalve species commonly used in aquaculture. For the first time, it synthesises this evidence to provide a global assessment of the potential market and non‐market economic value of bivalve aquaculture. Bivalves are filter feeders, filtering water and particulates, creating substrates which provide habitat to act as nursery grounds for other species. Goods from provisioning services include meat, worth an estimated $23.9 billion as well as, pearls, shell and poultry grit, with oyster shell being the most important, with a global potential worth of $5.2 billion. The most important regulating services are nutrient remediation. Cultivated bivalves remove 49,000 tonnes of nitrogen and 6,000 tonnes of phosphorus, worth a potential $1.20 billion. Currently, there is little evidence on the cultural services per year of bivalve aquaculture, but we argue that these cultural values are broad ranging, although difficult to quantify. Our assessment indicates that the global, non‐food bivalve aquaculture services are worth $6.47 billion ($2.95 billion–9.99 billion) per annum. However, this is likely to be an underestimate of the true value of bivalve aquaculture as there are significant gaps in evidence of the value for a number of key services. The analysis presented here can be used to indicate the likely scale of payments for ecosystem services provided by bivalve aquaculture, prior to more detailed assessments.
Chronicling the Risk and Risk Communication by Governmental Officials During the Zika Threat
Authors: Allen Marin Pearson
Published: November 2018

The unique circumstances surrounding Zika, including the fact that it is both mosquito‐borne and sexually transmissible, brought to the fore concerns about optimal ways to communicate risk in an environment characterized by rapidly evolving knowledge. The difficulty in doing so is magnified by the fact that science‐based health messages from governmental agencies must be developed in an evidence‐based, audience‐participative, and collaborative manner. A recent reminder in JAMA asserted the importance of preparing now for future threats. Understanding how the knowledge and messaging about Zika changed across time should help public health officials prepare for such challenges.
Looking for Meaning in All the Wrong Places: Country Music and the Politics of Identity*
Authors: Meier Kenneth J.
Published: November 2018

Objective

This study argues that country music can be viewed in terms of identity politics that seeks to define an American identity.

Methods

A textual analysis of country music songs is used to illustrate the various components of this American identity associated with the U.S. South and West.

Results

Six key dimensions of the country music American identity are identified‐–the goodness of the common man, family values, patriotism, race, religion, and nostalgia. Dissenting views on several themes are also illustrated.

Conclusion

U.S. country music can be viewed as the symbolic politics version of redistributive politics that defines values to be accepted and cherished as well as values to be denigrated and shunned.
Trait discovery and editing in tomato
Authors: Rothan Christophe , Diouf Isidore , Causse Mathilde
Published: November 2018

Tomato (Solanum lycopersicum), which is used for both processing and fresh markets, is a major crop species that is the top ranked vegetable produced over the world. Tomato is also a model species for research in genetics, fruit development and disease resistance. Genetic resources available in public repositories comprise the 12 wild related species and thousands of landraces, modern cultivars and mutants. In addition, high quality genome sequences are available for cultivated tomato and for several wild relatives, hundreds of accessions have been sequenced, and databases gathering sequence data together with genetic and phenotypic data are accessible to the tomato community. Major breeding goals are productivity, resistance to biotic and abiotic stresses, and fruit sensorial and nutritional quality. New traits, including resistance to various biotic and abiotic stresses and root architecture, are increasingly being studied. Several major mutations and quantitative trait loci (QTLs) underlying traits of interest in tomato have been uncovered to date and, thanks to new populations and advances in sequencing technologies, the pace of trait discovery has considerably accelerated. In recent years, clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 gene editing (GE) already proved its remarkable efficiency in tomato for engineering favorable alleles and for creating new genetic diversity by gene disruption, gene replacement, and precise base editing. Here, we provide insight into the major tomato traits and underlying causal genetic variations discovered so far and review the existing genetic resources and most recent strategies for trait discovery in tomato. Furthermore, we explore the opportunities offered by CRISPR/Cas9 and their exploitation for trait editing in tomato.
Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/Cas9‐mediated kif15 mutations accelerate axonal outgrowth during neuronal development and regeneration in zebrafish
Authors: Dong Zhangji , Wu Shuwen , Zhu Chenwen , Wang Xueting , Li Yuanyuan , Chen Xu , Liu Dong , Qiang Liang , Baas Peter W. , Liu Mei
Published: November 2018

KIF15, the vertebrate kinesin‐12, is best known as a mitotic motor protein, but continues to be expressed in neurons. Like KIF11 (the vertebrate kinesin‐5), KIF15 interacts with microtubules in the axon to limit their sliding relative to one another. Unlike KIF11, KIF15 also regulates interactions between microtubules and actin filaments at sites of axonal branch formation and in growth cones. Our original work on these motors was done on cultured rat neurons, but we are now using zebrafish to extend these studies to an in vivo model. We previously studied kif15 in zebrafish by injecting splice‐blocking morpholinos injected into embryos. Consistent with the cell culture work, these studies demonstrated that axons grow faster and longer when KIF15 levels are reduced. In the present study, we applied CRISPR/Cas9‐based knockout technology to create kif15 mutants and labeled neurons with Tg(mnx1:GFP) transgene or transient expression of elavl3:EGFP‐alpha tubulin. We then compared by live imaging the homozygotic, heterozygotic mutants to their wildtype siblings to ascertain the effects of depletion of kif15 during Caudal primary motor neuron and Rohon‐Beard (R‐B) sensory neuron development. The results showed, compared to the kif15 wildtype, the number of branches was reduced while axon outgrowth was accelerated in kif15 homozygotic and heterozygotic mutants. In R‐B sensory neurons, after laser irradiation, injured axons with loss of kif15 displayed significantly greater regenerative velocity. Given these results and the fact that kif15 drugs are currently under development, we posit kif15 as a novel target for therapeutically augmenting regeneration of injured axons.
Arab-Origin Students’ Experiences of Learning Turkish: A Case Study
Authors: Tayşi Esra Karakuş
Published: November 2018

The purpose of this study is to consider the Turkish learning situations of the 16 Arab-origin students learning Turkish at TÖMER subordinate to a state university in the Aegean region from the perspectives of both students and the teachers who teach them Turkish and investigate their language learning experiences from many perspectives. In order to achieve this goal, a qualitative research method was used. Data were collected from the participating students and lecturers through semi-structured interviews. The method of content analysis was used in the data analysis. Based on the findings obtained in the data analysis, it was concluded that the students stated that; they learnt Turkish to study at a university and because they had to live in Turkey; they had the most difficulty in the writing skill; they found the Turkish lessons difficult due to the different language structure and alphabet. On the other hand, the participating lecturers stated that; the students had difficulties in writing; they used Turkish by having conversations with Turkish native speakers and at work; the mistakes they made the most were suffix and spelling mistakes, and in order to solve these problems, they got the students to play concept games, and had lessons in different places outside the classroom by getting the students to do a lot of practice.
Improvement in Film Cooling Effectiveness Using Single and Double Rows of Holes With Adverse Compound Angle Orientations
Authors: Kannan E. , Sivamani Seralathan , Roychowdhury D. G. , Micha Premkumar T. , Hariram V.
Published: November 2018

Three-dimensional Reynolds-averaged Navier–Stokes equations with shear stress transport turbulence model are used to analyze the film cooling effectiveness on a flat plate having single row of film hole involving cylindrical hole (CH) and laidback hole (LBH). The CH and LBH are inclined at 35 deg to the surface with a compound angle (β) orientation ranging from favorable to adverse inclination (i.e., β = 0–180 deg) and examined at high and low blowing ratios (M = 1.25 and 0.60). CH with an adverse compound angle of 135 deg gives the highest area-averaged film cooling effectiveness in comparison with LBH configuration. Also, CH β = 135 deg film hole shows a higher lateral coolant spread. Later, double jet film cooling (DJFC) concept is studied for this CH. In all the cases, the first hole compound angle is fixed as 135 deg, and the second hole angle is varied from 135 deg to 315 deg. At high blowing ratio, the dual jet cylindrical hole (DJCH) with β = 135 deg, 315 deg gives a higher area-averaged film cooling effectiveness by around 66.50% compared to baseline CH β = 0 deg. On comparing all CH, LBH, and DJCH cases, the highest area-averaged film cooling effectiveness is obtained by CH configuration with β = 135 deg. Hence, the CH with its adverse compound angle (β = 135 deg) orientation could be an appropriate film cooling configuration for gas turbine blade cooling.
Early Warning Signs of Imminent Thermoacoustic Oscillations Through Critical Slowing Down
Authors: An Qiang , Steinberg Adam M. , Jella Sandeep , Bourque Gilles , Füri Marc
Published: November 2018

Critical slowing down (CSD) is a phenomenon that is common to many complicated dynamical systems as they approach critical transitions/bifurcations. We demonstrate that pressure signals measured during the onset of thermoacoustic instabilities in a gas turbine engine test exhibit evidence of CSD well before the oscillation amplitude increases. CSD was detected through both the variance and the lag-1 auto-regressive coefficient in a rolling window of the pressure signal. Increasing trends in both metrics were quantified using Kendall's τ, and the robustness and statistical significance of the observed increases were confirmed. Changes in the CSD metrics could be detected several seconds prior to changes in the oscillation amplitude. Hence, real-time calculation of these metrics holds promise as early warning signals of impending thermoacoustic instabilities.
Comparison of Biomechanical Properties and Microstructure of Trabeculae Carneae, Papillary Muscles, and Myocardium in the Human Heart
Authors: Fatemifar Fatemeh , Feldman Marc D. , Oglesby Meagan , Han Hai-Chao
Published: November 2018

Trabeculae carneae account for a significant portion of human ventricular mass, despite being considered embryologic remnants. Recent studies have found trabeculae hypertrophy and fibrosis in hypertrophied left ventricles with various pathological conditions. The objective of this study was to investigate the passive mechanical properties and microstructural characteristics of trabeculae carneae and papillary muscles compared to the myocardium in human hearts. Uniaxial tensile tests were performed on samples of trabeculae carneae and myocardium strips, while biaxial tensile tests were performed on samples of papillary muscles and myocardium sheets. The experimental data were fitted with a Fung-type strain energy function and material coefficients were determined. The secant moduli at given diastolic stress and strain levels were determined and compared among the tissues. Following the mechanical testing, histology examinations were performed to investigate the microstructural characteristics of the tissues. Our results demonstrated that the trabeculae carneae were significantly stiffer (Secant modulus SM2 = 80.06 ± 10.04 KPa) and had higher collagen content (16.10 ± 3.80%) than the myocardium (SM2 = 55.14 ± 20.49 KPa, collagen content = 10.06 ± 4.15%) in the left ventricle. The results of this study improve our understanding of the contribution of trabeculae carneae to left ventricular compliance and will be useful for building accurate computational models of the human heart.
Optimal Distribution of Active Modules in Reconfiguration Planning of Modular Robots
Authors: Yao Meibao , Xiao Xueming , Belke Christoph H. , Cui Hutao , Paik Jamie
Published: November 2018

Reconfigurability in versatile systems of modular robots is achieved by appropriately actuating individual modular units. Optimizing the distribution of active and passive modules in modular architecture can significantly reduce both cost and energy of a reconfiguration task. This paper presents a methodology for planning this distribution in modular robots, resulting in a minimum number of active modules that guarantees the capability to reconfigure. We discuss the optimal distribution problem in layout-based and target-based planning schemes such that modular robots can instantly respond to reconfiguration commands with either an initial planar layout or a target configuration as input. We propose heuristic algorithms as solutions for the different scenarios, which we demonstrate by applying them to Mori, a modular origami robot, in simulation. The results show that our algorithms yield high-quality distribution schemes in reduced time, and are thus viable for real-time applications in modular robotic systems.
Linear Multi-Target Integrated Probabilistic Data Association Filter With Automatic Track Management for Autonomous Vehicles
Authors: Hunde Andinet , Ayalew Beshah
Published: November 2018

Target tracking in public traffic calls for a tracking system with automated track initiation and termination facilities in a randomly evolving driving environment. In addition, the key problem of data association needs to be handled effectively considering the limitations in the computational resources onboard an autonomous car. In this paper, we discuss a multi-target tracking system that addresses target birth/initiation and death/termination processes with automatic track management feature. The tracking system is based on Linear Multi-target Integrated Probabilistic Data Association Filter (LMIPDAF), which is adapted to specifically include algorithms that handle track initiation and termination, clutter density estimation and track management. The performance of the proposed tracking algorithm is compared to other single and multi-target tracking schemes and is shown to have acceptable tracking error. It is further illustrated through multiple traffic simulations that the computational requirement of the tracking algorithm is less than that of optimal multi-target tracking algorithms that explicitly address data association uncertainties.
An Online Model Predictive Control Framework for Robot Driver Speed Control
Authors: Wang Jing , Wang Yan , Filev Dimitar
Published: November 2018

In this paper, we present an online adaptive model predictive control (MPC) method for the robot driver speed control problem. The control structure contains three essential components: a regularized least square method to identify a time varying state space model for the vehicle system; a Kalman Filter (KF) to identify the internal states of the model; and a model predictive controller (MPC) to generate the control input based on properly constructed optimization objective and constraints. We cast the robot driver speed tracking problem as an acceleration tracking problem which we solve as an optimization problem with time varying constraints that are dependent on vehicle speed and acceleration. Simulation results on the FTP city drive cycle shows that the proposed approach has good speed tracking capability with minimal calibration efforts. and the controller is adaptive to variation on vehicle weight without degrading control performance.
Further Results on Finite-Time Distributed Control of Multiagent Systems With Time Transformation
Authors: Arabi Ehsan , Yucelen Tansel , Singler John R.
Published: November 2018

In previous work, a (smooth) finite-time distributed control algorithm with time transformation was introduced for first-order multiagent systems, which guarantees convergence of the single state of agents to a time-varying leader at a-priori given, user-defined time T from any arbitrary initial conditions with bounded local control signals. In this paper, we present an extension of this previous work to second-order multiagent systems. Specifically, utilizing a user-defined finite-time interval of interest t ∈ [0, T), we time transform this class of multiagent systems subject to the considered (smooth) distributed control algorithm to an infinite-time interval s ∈ [0, ∞) with s being the stretched time. Based on a property of this time transformation, this results in finite-time convergence as the regular time t approaches to T from any arbitrary initial conditions with bounded local control and internal signals. Finally, two numerical examples illustrate the efficacy of the proposed algorithm.
Voltage Response for Parametrically Actuated MEMS Cantilever Beam Using Homotopy Analysis Method and Method of Multiple Scales
Authors: Reyes Christopher , Caruntu Dumitru I.
Published: November 2018

The purpose of this paper is to investigate the nonlinear dynamics governing the behavior of electrostatically actuated micro electro mechanical systems (MEMS) cantilever undergoing parametric resonance. The MEMS consists of a cantilever parallel to a ground plate. The beam is actuated via an A/C voltage with excitation frequency near first natural frequency of the cantilever. The model includes damping, electrostatic, and Casimir (or van der Waals) forces. The electrostatic force is modeled to include the fringe effect. The amplitude-voltage response of the parametric resonance and the effects of varying the magnitudes of the fringe, Casimir (or Van der Waals), and damping forces along with varying the detuning parameter are reported. The response is obtained using two different methods, namely the method of multiple scales (MMS), and the homotopy analysis method (HAM). In this study approximations up to a 2nd order HAM are used. HAM is a deformation technique that begins with an initial guess and continuously deforms it to the exact answer. For the 1st Order HAM, a softening effect is reported. The 1st Order HAM matches the MMS results in low amplitude and begins to soften and deviate away from the MMS solution in higher amplitudes. For the 2nd Order HAM deformation the softening effect is slightly more pronounced with a slightly lower prediction of the maximum deflection of the cantilever tip. For the 2nd order deformation solution the stable branch of the amplitude-voltage response obtained by the HAM shifts leftward from the MMS solution with the unstable branches between the two methods continue to agree in low amplitudes and deviate in high amplitudes. As a remark, the higher order HAM solutions are obtained symbolically with the software Mathematica and numerically ran with the software Matlab.
Optimal Eco-Approach Control With Traffic Prediction for Connected Vehicles
Authors: Shao Yunli , Sun Zongxuan
Published: November 2018

This work proposes a unified framework for the eco-approach application that integrates traffic prediction, vehicle optimization, and implementation. The eco-approach application is formulated as either a car-following optimization problem or a single vehicle optimization problem, depending on whether a preceding vehicle exists. The traffic prediction scheme anticipates future traffic conditions and describes the traffic dynamics on the road segment of interest using state variables: traffic flow, density, and speed. With the information enabled by connectivity, the traffic state estimation is updated using an observer. Uncertainties in the traffic prediction are considered using a robust optimization approach. The robust optimization problem is discretized and solved by an efficient nonlinear programming solver. The proposed eco-approach framework is implemented to a single lane single intersection scenario for 12, 8, 4, and 1 connected vehicle scenarios. The fuel benefits vary from 11.0% to 6.7% as the penetration rates of connectivity decrease. The performance is satisfactory compared to the 12.0% fuel benefits with perfection traffic prediction.
Reachability Analysis for Robustness Evaluation of the Sit-to-Stand Movement for Powered Lower Limb Orthoses
Authors: Narvaez-Aroche Octavio , Packard Andrew , Meyer Pierre-Jean , Arcak Murat
Published: November 2018

A sensitivity-based approach for computing over-approximations of reachable sets, in the presence of constant parameter uncertainty and a single initial state, is used to analyze a three-link planar robot modeling a Powered Lower Limb Orthosis and its user. Given the nature of the mappings relating the state and parameters of the system with the input, and output describing the trajectories of its Center of Mass, reachable sets for their respective spaces can be obtained relying on the sensitivities of the nonlinear closed-loop dynamics in the state space. These over-approximations are used to evaluate the worst-case performances of a finite time horizon linear-quadratic regulator for controlling the ascending phase of the Sit-To-Stand movement.
Application of Mixed H2/H∞ Data Driven Control Design to Dual Stage Hard Disk Drives
Authors: Bagherieh Omid , Shah Prateek , Horowitz Roberto
Published: November 2018

A data driven control design approach in the frequency domain is used to design track following feedback controllers for dual-stage hard disk drives using multiple data measurements. The advantage of the data driven approach over model based approach is that, in the former approach the controllers are directly designed from frequency responses of the plant, hence avoiding any model mismatch. The feedback controller is considered to have a Sensitivity Decoupling Structure. The data driven approach utilizes H∞ and H2 norms as the control objectives. The H∞ norm is used to shape the closed loop transfer functions and ensure closed loop stability. The H2 norm is used to constrain and/or minimize the variance of the relevant signals in time domain. The control objectives are posed as a locally convex optimization problem. Two design strategies for the dual-stage hard disk drive are presented.
Modeling and Optimal Control of Micro-CSP and a Building HVAC System to Minimize Electricity Cost
Authors: Reddy Chethan R. , Toub Mohamed , Razmara Meysam , Shahbakhti Mahdi , Robinett Rush D. , Aniba Ghassane
Published: November 2018

This paper presents a model predictive control (MPC) framework to minimize the energy cost associated with the building heating, ventilation, and air-conditioning (HVAC) system integrated with a micro-scale concentrated solar power (MicroCSP) system. To this end, a MicroCSP model is developed and then integrated to the building model of an office building in Michigan Technological University. Then, an MPC framework is designed to optimize MicroCSP electrical and thermal energy flows for HVAC use in the building. The optimal control results show that the designed MPC framework reduces the HVAC energy cost by 37–42% for a sample sunny day by optimally utilizing the solar energy, compared to the HVAC system without MicroCSP with an MPC controller. The cost saving varies from 12% to 47% depending on seasonal weather variations.
Energy Availability Study for a Regenerative Hydraulically Assisted Turbocharger
Authors: Zeng Tao , Men Yifan , Upadhyay Devesh , Zhu Guoming
Published: November 2018

Engine downsizing and down-speeding are essential to meet future US fuel economy mandates. While turbocharging has been a critical enabler for downsizing, transient boost response performance remains a concern even with variable geometry turbochargers. This slow build-up of boost and hence torque is commonly referred to as turbo-lag. Mitigation of turbo-lag has, therefore, remained an important objective of turbocharger performance enhancement research. A regenerative, hydraulically assisted turbocharger is one such enhanced turbocharging system that is able regulate the turbocharger speed independent of the available engine exhaust energy. With external power available on the turbocharger shaft, the engine performance and emissions can be managed during both transient and steady-state operations. The key to fully utilizing the ability of such an assisted turbocharger depends on the energy recovered from turbocharger shaft and/or vehicle driveline. Energy available from the turbocharger shaft is dependent on the engine exhaust gas energy. Energy recovered from the driveline depends on vehicle braking energy. A previously developed high-fidelity 1-D simulation of a diesel engine with a regenerative-hydraulically assisted turbocharger is used to investigate the energy availability for a medium duty diesel engine over standard driving cycles. The study shows that the energy recovery from turbocharger shaft is limited and driveline energy recovery is necessary for achieving fuel economy benefits on the order of 4%.
Optimization of Energy-Efficient Speed Profile for Electrified Vehicles
Authors: Abbas Hadi , Kim Youngki , Siegel Jason B. , Rizzo Denise M.
Published: November 2018

This paper presents a study of energy-efficient operation of vehicles with electrified powertrains leveraging route information, such as road grades, to adjust the speed trajectory. First, Pontryagin’s Maximum Principle (PMP) is applied to derive necessary conditions and to determine the possible operating modes. The analysis shows that only 5 modes are required to achieve minimum energy consumption; full propulsion, cruising, coasting, full regeneration, and full regeneration with conventional braking. The minimum energy consumption problem is reformulated and solved in the distance domain using Dynamic Programming to optimize speed profiles. A case study is shown for a light weight military robot including road grades. For this system, a tradeoff between energy consumption and trip time was found. The optimal cycle uses 20% less energy for the same trip duration, or could reduce the travel time by 14% with the same energy consumption compared to the baseline operation.
Model Predictive Control of a Pumped Two-Phase Cooling System With Microchannel Heat Exchangers
Authors: Angatkina Oyuna , Alleyne Andrew
Published: November 2018

Two-phase cooling systems provide a viable technology for high–heat flux rejection in electronic systems. They provide high cooling capacity and uniform surface temperature. However, a major restriction of their application is the critical heat flux condition (CHF). This work presents model predictive control (MPC) design for CHF avoidance in two-phase pump driven cooling systems. The system under study includes multiple microchannel heat exchangers in series. The MPC controller performance is compared to the performance of a baseline PI controller. Simulation results show that while both controllers are able to maintain the two-phase cooling system below CHF, MPC has significant reduction in power consumption compared to the baseline controller.