bluuebunny/crossref_metadata_2025 huggingface dataset:
Harmonic suppression analysis of a harmonic filtering distribution transformer with integrated inductors based on field–circuit coupling simulation
Authors: Xu Jiazhu , Gu Xiutian , Liang Chonggan , Bai Ziyi , Kubis Andreas
Published: September 2017

This study analyses and evaluates the feasibility of a harmonic filtering distribution transformer (HFDT) for a harmonic reduction in low‐voltage distribution networks. With this new‐type transformer, power quality of the distribution systems can be improved by preventing the low‐voltage‐side harmonic currents from penetrating the higher voltage side. As the physical size of available space in prefabricated substations is strictly limited, necessary low space occupying filtering techniques are needed. Therefore, an HFDT with integrated filtering inductors (IFIs) capable of being implemented in regular air‐insulated prefabricated substations is proposed. Two sets of passive filters configured by IFIs and external capacitors are employed for harmonic filtering. Two methods for estimating the inductance parameter are provided. One is the dimension‐based method and the other is the reduced‐order inductance matrix method. The relevant harmonic reduction analysis is based on simulations with a field–circuit coupling model, which consists of a three‐dimensional finite‐element electromagnetic model of an HFDT with IFIs and a corresponding electric circuit of a simplified distribution network. These simulations prove that the described HFDT can effectively reduce specific harmonic currents with IFI‐based filters. Finally, the successful suppression of harmonics is demonstrated and discussed based on field‐test measurements.
Design of normalised and simplified FAs in quantum‐dot cellular automata
Authors: Zhang Yongqiang , Xie Guangjun , Sun Mengbo , Lv Hongjun
Published: September 2017

Quantum‐dot cellular automata (QCA), which is a burgeoning technique at nanoscale region to take the important place of complementary metal–oxide–semiconductor technology, has been studied for several years. The recent primary research emphasis is mainly focusing on circuit design, for instance, full adders (FAs) and multiplexers. The authors will present a new five‐input majority gate to construct FAs. Three QCA normalised FAs based on different logical expressions are then selected and designed, denoted as NFA1–NFA3, respectively. To conveniently compare with existing adders, three simplified FAs are also designed, named SFA1–SFA3. Analysis results indicate that SFA3 presents better performance in some extent.
Detailed chemical abundance analysis of the thick disk star cluster Gaia 1
Authors: Koch Andreas , Hansen Terese T. , Kunder Andrea
Published: September 2017

Star clusters, particularly those objects in the disk-bulge-halo interface are as yet poorly charted, despite the fact that they carry important information about the formation and the structure of the Milky Way. Here, we present a detailed chemical abundance study of the recently discovered object Gaia 1. Photometry has previously suggested it as an intermediate-age, moderately metal-rich system, although the exact values for its age and metallicity remained ambiguous in the literature. We measured detailed chemical abundances of 14 elements in four red giant members, from high-resolution (R = 25 000) spectra that firmly establish Gaia 1 as an object associated with the thick disk. The resulting mean Fe abundance is −0.62 ± 0.03(stat.)± 0.10(sys.) dex, which is more metal-poor than indicated by previous spectroscopy from the literature, but it is fully in line with values from isochrone fitting. We find that Gaia 1 is moderately enhanced in the α-elements, which allowed us to consolidate its membership with the thick disk via chemical tagging. The cluster’s Fe-peak and neutron-capture elements are similar to those found across the metal-rich disks, where the latter indicate some level of s-process activity. No significant spread in iron nor in other heavy elements was detected, whereas we find evidence of light-element variations in Na, Mg, and Al. Nonetheless, the traditional Na-O and Mg-Al (anti-)correlations, typically seen in old globular clusters, are not seen in our data. This confirms that Gaia 1 is rather a massive and luminous open cluster than a low-mass globular cluster. Finally, orbital computations of the target stars bolster our chemical findings of Gaia 1’s present-day membership with the thick disk, even though it remains unclear which mechanisms put it in that place.
Tracing the stellar component of low surface brightness Milky Way dwarf galaxies to their outskirts
Authors: Cicuéndez L. , Battaglia G. , Irwin M. , Bermejo-Climent J. R. , McMonigal B. , Bate N. F. , Lewis G. F. , Conn A. R. , de Boer T. J. L. , Gallart C. , Guglielmo M. , Ibata R. , McConnachie A. , Tolstoy E. , Fernando N.
Published: September 2017

Aims.We present results from deep and very spatially extended CTIO/DECamgandrphotometry (reaching out to ~2 mag below the oldest main-sequence turn-off and covering ~20 deg2) around the Sextans dwarf spheroidal galaxy. We aim to use this dataset to study the structural properties of Sextans overall stellar population and its member stars in different evolutionary phases, as well as to search for possible signs of tidal disturbance from the Milky Way, which would indicate departure from dynamical equilibrium.

Methods.We performed the most accurate and quantitative structural analysis to-date of Sextans’ stellar components by applying Bayesian Monte Carlo Markov chain methods to the individual stars’ positions. Surface density maps are built by statistically decontaminating the sample through a matched filter analysis of the colour-magnitude diagram, and then analysed for departures from axisymmetry.

Results.Sextans is found to be significantly less spatially extended and more centrally concentrated than early studies suggested. No statistically significant distortions or signs of tidal disturbances were found down to a surface brightness limit of ~31.8 mag/arcsec2inV-band. We identify an overdensity in the central regions that may correspond to previously reported kinematic substructure(s). In agreement with previous findings, old and metal-poor stars such as Blue Horizontal Branch stars cover a much larger area than stars in other evolutionary phases, and bright Blue Stragglers (BSs) are less spatially extended than faint ones. However, the different spatial distribution of bright and faint BSs appears consistent with the general age and metallicity gradients found in Sextans’ stellar component. This is compatible with Sextans BSs having formed by evolution of binaries and not necessarily due to the presence of a central disrupted globular cluster, as suggested in the literature. We provide structural parameters for the various populations analysed and make publicly available the photometric catalogue of point-sources as well as a catalogue of literature spectroscopic measurements with updated membership probabilities.
Accuracy and Safety of Ventriculostomy Using Two Different Procedures of External Ventricular Drainage: A Single-Center Series
Authors: Wispel Christian , Borger Valeri , Güresir Ági , Vatter Hartmut , Güresir Erdem , Schuss Patrick
Published: September 2017

Background and Study Aims Patients with acute hydrocephalus are treated by either insertion of a conventional external ventricular drain (EVD) or percutaneous needle trephination (PNT) at our institution, depending on the acuteness of intervention and the severity of illness. We compared both procedures regarding accuracy and safety necessitating surgical revision of EVD or PNT.

Methods Between January 2012 and January 2014, 451 ventriculostomies were performed in 301 patients at our institution. All patients underwent routine computed tomography after insertion of the ventricular drain during the treatment course. Patient characteristics, underlying pathology, ventriculostomy modality, radiologic features, catheter tip location, and treatment-related complications were analyzed.

Results A total of 307 of 451 ventriculostomy procedures (68%) were performed as conventional EVD, and 144 (32%) were performed as PNT. Overall, 11% of patients with conventional EVD underwent surgical revision due to lacking accuracy, infection, or hemorrhage; 7% of patients with PNT underwent surgical revision (p = 0.2). However, multivariate analysis revealed that only “hospital stay > 21 days” as an independent variable was significantly associated with surgical revision after ventriculostomy.

Conclusion The present data indicate that PNT has a similar safety profile in emergency situations in critically ill patients who need immediate treatment for acute hydrocephalus when compared with the conventional EVD procedure.
Fetal Thoracoamniotic Shunting in a Case of Congenital Pulmonary Airway Malformations with Hydrops Fetalis
Authors: Nitta Hayase , Taira Yusuke , Kinjo Tadatsugu , Chinen Yukiko , Masamoto Hitoshi , Sanabe Naoya , Goya Hideki , Yoshida Tomohide , Sugibayashi Rika , Sumie Masahiro , Wada Seiji , Sago Haruhiko , Aoki Yoichi
Published: September 2017

Aim We report a case of congenital pulmonary airway malformation (CPAM) with hydrops in which the fetus underwent thoracoamniotic shunting.

Case Report A 40-year-old (G1P1) woman was diagnosed with a macrocystic CPAM. Thoracoamniotic shunting was performed at 19 weeks of gestation but not well drained and was successfully performed again at 23 weeks. However, the CPAM volume ratio, abdominal circumference, and amniotic fluid index started increasing from 28 weeks and hydrops worsened. The insufficient shunting and the fetal cardiac failure had to be considered. At 32 weeks, a male infant with general edema and massive ascites was born weighing 3,362 g (+4.79 SD) with Apgar scores of 2 and 4. The infant was intubated and high-frequency oscillation and nitric oxide therapies were instituted. The resection of CPAM was performed on day 2. Nasal continuous positive airway pressure was instituted on day 16. The infant was discharged and prescribed with home oxygen therapy (HOT) on day 65. The infant was able to leave the HOT at 30 months and is currently 34 months of age in good condition.

Conclusion Fetal thoracoamniotic shunting may be life-saving in CPAM complicated by hydrops and that this treatment might be sufficient to cure the child.
Risk of Expectant Management and Optimal Timing of Delivery in Low-Risk Term Pregnancies: A Population-Based Study
Authors: Nazeer Sarah , Kumar Komal , Warren Morgan , Dai Jing , Sokol Robert , Vilchez Gustavo
Published: September 2017

Objective The benefits of the 39-week rule have been questioned and concerns of increased stillbirth after adoption of this rule have been raised. Whether expectant management risks outweigh the benefits of awaiting 39 weeks has not been studied. We analyze the risks of expectant management at term and the optimal timing for delivery.

Study Design All U.S. nonanomalous singleton term deliveries in 2013 were selected, excluding diabetes/hypertension, and low birth weight. Maternal/neonatal complications and stillbirth/infant death were compared among expectant management versus deliveries at each term gestational age. Logistic regression was used to calculate adjust odds ratios of complications according to delivery plan at each gestational age.

Results From approximately 3 million deliveries, maternal complications during expectant management were lower at early term, and became higher at 39 weeks, relative risk [RR] (95% confidence interval [CI]) = 1.18 (1.16–1.19). Neonatal complications during expectant management were lower during early term, and became higher at ≥39 weeks, RR (95% CI) = 1.09 (1.08–1.09). The risk of perinatal mortality in the expectant management group was lower during early term, and became higher at ≥39 weeks, 18.93 (17.83–20.10) versus 17.37 (16.61–18.16), p = 0.010.

Conclusion Complications during expectant management occurring while awaiting full term do not outweigh the benefits of better outcomes from reaching 39 weeks. However, extending beyond 39 weeks may put these pregnancies at an increased risk.
Übergewicht und Nierenerkrankungen – renale Risiken einer „Epidemie“
Authors: Schiffl Helmut , Lang Susanne
Published: September 2017

Overweight and obesity are widespread in the German population, affecting not only adults but also a significant number of children and adolescents. The risk to develop chronic kidney disease is markedly increased in overweight or adipose children, adolescents and adults.

Overweight and obesity induced risk factors have a direct impact on the development of chronic renal disease (obesity-associated focal segmental glomerulosclerosis). They accelerate the progression of coexistent nephropathies (diabetic or hypertensive nephropathy, primary glomerulonephritides) and are independent risk factors for the development of acute kidney injury in critically ill patients.

Obesity induced nephropathies are basically preventible. Marked weight reduction, normoglycemia and control of hypertension may contribute to an improved glomerular filtration rate and/or reduced proteinuria in early stages of renal damage.

The prevalence of kidney diseases in Germany is 13 % and estimated 80 000 patients need renal replacement therapy. In order to avoid a further rapid increase in numbers, preventive measures should be enforced more rigorously.

It is necessary to raise the awareness of the negative consequences of obesity in the general public, to motivate the public to adopt a healthier lifestyle and to install nephrological surveillance to contain the obesity „epidemic“.
Light absorption enhancement in thin-film GaAs solar cells with flattened light scattering substrates
Authors: Sai Hitoshi , Mizuno Hidenori , Makita Kikuo , Matsubara Koji
Published: September 2017

A flattened light scattering substrate (FLiSS) was investigated for enhancing the light absorption in thin-film GaAs solar cells. The FLiSS investigated in this work was limited to those composed of periodic refractive index distribution, although its concept is not necessarily limited to such a structure. The following guidelines were found via optical simulation: (i) the morphological distribution of refractive indices in a FLiSS plays a key role, and an inverted pyramid-like shape is very efficient in light scattering. (ii) There are an optimum period and a depth in a FLiSS, although efficient light scattering is achievable in a wide parameter space. However, periods less than 0.4 μm result in poor light scattering effect. (iii) The contrast in the refractive indices of the two materials in the FLiSS should be large enough, typically Δn > 1.5. At the same time, parasitic absorption loss in the FLiSS must be minimized. An optimized FLiSS, which satisfies the requirements mentioned above, can increase the absorption in thin GaAs cells more efficiently than a flat reflector, and a high current density of approximately 30 mA/cm2 is potentially achievable with a 1-μm-thick absorber. For experimental verification, a 2D grating FLiSS with InZnO and amorphous Si was developed and applied to thin film GaAs solar cells. As a result, a significant increase in the current density as well as in the spectral response in a long wavelength region was demonstrated, as expected from the optical simulation.
Metal-insulator-metal antennas in the far-infrared range based on highly doped InAsSb
Authors: Omeis F. , Smaali R. , Gonzalez-Posada F. , Cerutti L. , Taliercio T. , Centeno E.
Published: September 2017

Plasmonic behavior in the far-infrared (IR) and terahertz (THz) ranges can facilitate a lot of applications in communication, imaging or sensing, security, and biomedical domains. However, simple scaling laws cannot be applied to design noble metal-based plasmonic systems operating at far-IR or THz frequencies. To overcome this issue, we numerically and experimentally explore the plasmonic properties in the spectral range between 25 and 40 μm (12 and 7.5 THz) of metal-insulator-metal (MIM) antennas made of InAsSb a highly Si-doped semiconductor. We demonstrate that these MIM antennas sustain a gap plasmon mode that is responsible for high light absorption. By tracking this peculiar plasmonic signature for various antennas' widths, we prove that Si-doped InAsSb microstructures realized on large areas by laser lithography and the wet etching process are a low cost, reproducible, and readily CMOS compatible approach.
Parasitic phases at the origin of magnetic moment in BiFeO3 thin films grown by low deposition rate RF sputtering
Authors: Mori Thiago J. A. , Mouls Caroline L. , Morgado Felipe F. , Schio Pedro , Cezar Júlio C.
Published: September 2017

A series of epitaxial BiFeO3 thin films has been grown under high partial pressure in a pure O2 atmosphere, which leads to a low deposition rate. The samples grown under these conditions have presented an evolution of the quality of the epitaxy as the deposition temperature increases, however, spurious β–Bi2O3 and supertetragonal BiFeO3 phases are present in the films grown at higher temperatures. The presence of γ–Fe2O3 is reported in one growing condition, and has been attributed to the origin of hysteretic ferromagnetic behavior. A second kind of magnetism, with higher magnetic moment and anhysteretic behaviour, is attributed to the presence of mixed phases of BiFeO3.
Measurements of heat and humidity fluxes in the wake of offshore wind turbines
Authors: Foreman R. J. , Cañadillas B. , Neumann T. , Emeis S.
Published: September 2017

Eddy-covariance measurements of heat and humidity fluxes at heights of 40 m and 80 m above the sea surface in the wake of the alpha ventus wind farm in the North Sea at the FINO1 platform are presented and compared with fluxes estimated using the bulk method, which is generally applicable offshore outside of wake regions. While a clear difference is not found between bulk-estimated and eddy-covariance-derived fluxes in unstable conditions in the wake of the wind farm, a modified heat flux of between −10 W m−2 and −20 W m−2 with respect to the expected open-sea magnitudes is found within the wake during stable stratification at both measurement heights. These results demonstrate the importance of the realistic inclusion of buoyancy in modeling stable wind-farm wakes for offshore conditions and assessing their effect on the efficiency of downstream wind farms, as well as on the local climate.
A parametric study of the dynamic failure of energetic composites
Authors: Tanasoiu Bogdan , Koslowski Marisol
Published: September 2017

Heating by frictional sliding of cracks is often considered to be one of the most important causes of localized melting and ignition in solid explosives. Furthermore, recent high speed X-ray phase contrast experiments on energetic composites under dynamic compression [Parab et al., Appl. Phys. Lett. 109(13) (2016)] show that most fracture events appear inside the particles. Initial cracks develop in regions where particles are close, and widespread fragmentation is observed in the interior of the particles as the stress waves propagate through the sample. However, most simulations have focused on interface debonding of energetic composites and, in general, do not include fracture of the particles explicitly. A phase field damage approach is used to model the dynamic response of a system of cyclotetramethylene-tetranitramine particles embedded in a Sylgard matrix. The simulations show several damage mechanisms observed in the experiments. The effects of the energy release rate and the initial crack distribution on the energy dissipation due to fracture are studied. The numerical results confirm that initial cracks play an important role in the evolution of damage, energy dissipation and consequently, the formation of hot-spots.
Highly stable amorphous zinc tin oxynitride thin film transistors under positive bias stress
Authors: Niang K. M. , Bayer B. C. , Meyer J. C. , Flewitt A. J.
Published: September 2017

The stability of amorphous zinc tin oxynitride thin film transistors (a-ZTON TFTs) under positive bias stress (PBS) is investigated. Thin films are deposited by remote plasma reactive sputtering and are annealed at 300 °C in air for 1 h, after which films are confirmed to be highly amorphous by transmission electron microscopy. Typical a-ZTON TFTs exhibit a threshold voltage of 2.5 V, a field effect mobility of 3.3 cm2 V−1 s−1, a sub-threshold slope of 0.55 V dec−1, and a switching ratio over 106. Using a thermalization energy analysis, the threshold voltage shift under PBS is analysed. A maximum energy barrier to defect conversion up to 0.91 eV is found, which is significantly greater than that of the ∼0.75 eV energy barrier for amorphous indium gallium zinc oxide and amorphous zinc tin oxide TFTs previously reported. The improved stability of these oxynitride TFTs over amorphous oxide TFTs is explained by the elimination of less stable oxygen vacancies due to the passivation of oxygen vacancies with nitrogen. The higher attempt-to-escape frequency of 108 to 109 s−1 in a-ZTON TFTs compared with 107 s−1 in amorphous oxide semiconductor TFTs, on the other hand, is attributed to the high homogeneity of the amorphous film leading to strong carrier localization in the band tails.
Introduction: creating memorable experiences.
Authors: Ma JianYu Ma JianYu , Gao Jun Gao Jun , Scott N.
Published: September 2017

This introductory chapter focuses on the conceptualization of tourism experiences, and discusses the sub-topics of (i) tourism as experiences, (ii) tourist experience, and (iii) designed tourist experience.
Attentive tourists: the importance of co-creative experiences.
Authors: Campos A. C. , Mendes J. , Valle P. , Scott N.
Published: September 2017

This chapter focuses on co-creative on-site tourist experiences and how these stimulate attention and contribute to increased memorability. The chapter presents a case study of tourist experience and behaviour in the Dolphin Emotions Experience (DEE) at Zoomarine Park, Algarve, Portugal.
Well-being benefits from mindful experiences.
Authors: Chen ILing [Chen I. L. L. ] , Scott N. , Benckendorff P.
Published: September 2017

The study presented in this chapter adopts 'meditative mindfulness' as the theoretical foundation to examine if day-to-day leisure activities involved in travel could lead to well-being benefits. It is revealed that the studied Taiwanese backpackers experienced mindful states during their travels in Australia. These experiences occurred during open-ended backpacking journeys, at a range of different types of sites and in unplanned situations. Two main types of triggers facilitate a meditative mindful state: aesthetic appreciation and atmosphere of tranquility. The experiences led the tourists to gain benefits such as peace, mental relaxation, stress release and somatic relaxation.
Motivational satisfaction and emotional outcomes from experiences.
Authors: Ma JianYu Ma JianYu
Published: September 2017

This chapter reviews previous studies on emotions and their effects on the post-consumption experience, particularly in tourism. Sections discuss: satisfaction and positive emotions; satisfaction as an emotional response; motivational satisfaction and delight; and emotions and behavioural intentions.
Slow food tourism: preferences and behaviours.
Authors: Lee KuanHuei Lee KuanHuei
Published: September 2017

This chapter examines the effect of the decision making process and activity experiences in the destination on slow food travel experiences. This case study uses concepts like motivations, preferences as selective attentions, values and meanings in the context of slow food travel and describes the psychological characteristics of Slow Food members.
Liquid segregation behaviour of a semi-solid squeeze cast A356 aluminium cup-shaped part
Authors: Seiyed Beigi Mir Taher , Niroumand Behzad
Published: September 2017

In this study, the effects of pouring temperature (solid fraction of primary particles) on the structure and liquid segregation behaviour of a cup-shaped semi-solid rheocast processed casting made from the A356 aluminium alloy were investigated. Results showed that the solid fraction of primary particles at the bottom of the castings was greater than in other parts of the castings, and the highest liquid segregation occurred in the mid-height (wall) of the castings. Liquid segregation was increased with an increase in the initial solid fraction of primary particles. The critical solid fraction at pouring for minimum liquid segregation was found to be approximately 25%.

This paper is part of a thematic issue on Light Alloys.
Clonal deletion of T cell repertoires with specific T cell receptor Vβ chains by two endogenous superantigens in NC/Nga mice
Authors: Ohkusu-Tsukada Kozo , Tsukada Teruyo , Takahashi Kimimasa
Published: September 2017

Superantigens (SAgs) are powerful T-cell stimulatory proteins. Because an atopic dermatitis (AD) model NC/Nga mice had two endogenous SAgs, namely minor lymphocyte-stimulating locus-1a  (Mls-1a) and mouse mammary tumor virus (MMTV)(SHN), SAg-responsive T-cells bearing Vβ5.1, Vβ6, Vβ8.1, Vβ8.2, Vβ8.3, Vβ9, and Vβ11 should be endogenously deleted. Here, we discuss that the endogenous SAgs-expression may be involved in AD-sensitivity in NC/Nga mice.
Cargo-selective SNX-BAR proteins mediate retromer trimer independent retrograde transport
Authors: Kvainickas Arunas , Jimenez-Orgaz Ana , Nägele Heike , Hu Zehan , Dengjel Jörn , Steinberg Florian
Published: September 2017

The retromer complex, which recycles the cation-independent mannose 6-phosphate receptor (CI-MPR) from endosomes to the trans-Golgi network (TGN), is thought to consist of a cargo-selective VPS26–VPS29–VPS35 trimer and a membrane-deforming subunit of sorting nexin (SNX)–Bin, Amphyphysin, and Rvs (BAR; SNX-BAR) proteins. In this study, we demonstrate that heterodimers of the SNX-BAR proteins, SNX1, SNX2, SNX5, and SNX6, are the cargo-selective elements that mediate the retrograde transport of CI-MPR from endosomes to the TGN independently of the core retromer trimer. Using quantitative proteomics, we also identify the IGF1R, among more potential cargo, as another SNX5 and SNX6 binding receptor that recycles through SNX-BAR heterodimers, but not via the retromer trimer, in a ligand- and activation-dependent manner. Overall, our data redefine the mechanics of retromer-based sorting and call into question whether retromer indeed functions as a complex of SNX-BAR proteins and the VPS26–VPS29–VPS35 trimer.
Regulation of mitotic spindle assembly factor NuMA by Importin-β
Authors: Chang Chih-Chia , Huang Tzu-Lun , Shimamoto Yuta , Tsai Su-Yi , Hsia Kuo-Chiang
Published: September 2017

Ran–guanosine triphosphatase orchestrates mitotic spindle assembly by modulation of the interaction between Importin-α/-β and spindle assembly factors (SAFs). The inhibition of SAFs performed by importins needs to be done without much sequestration from abundant nuclear localization signal (NLS) –containing proteins. However, the molecular mechanisms that determine NLS-binding selectivity and that inhibit activity of Importin-β–regulated SAFs (e.g., nuclear mitotic apparatus protein [NuMA]) remain undefined. Here, we present a crystal structure of the Importin-α–NuMA C terminus complex showing a novel binding pattern that accounts for selective NLS recognition. We demonstrate that, in the presence of Importin-α, Importin-β inhibits the microtubule-binding function of NuMA. Further, we have identified a high-affinity microtubule-binding region that lies carboxyl-terminal to the NLS, which is sterically masked by Importin-β on being bound by Importin-α. Our study provides mechanistic evidence of how Importin-α/-β regulates the NuMA functioning required for assembly of higher-order microtubule structures, further illuminating how Ran-governed transport factors regulate diverse SAFs and accommodate various cell demands.
Margot Quinlan: Muscling in on oogenesis
Authors: O’Donnell Marie Anne
Published: September 2017

Quinlan investigates how the cytoskeleton polarizes oocytes.
CCmiR: a computational approach for competitive and cooperative microRNA binding prediction
Authors: Ding Jun , Li Xiaoman , Hu Haiyan
Published: September 2017

Motivation

The identification of microRNA (miRNA) target sites is important. In the past decade, dozens of computational methods have been developed to predict miRNA target sites. Despite their existence, rarely does a method consider the well-known competition and cooperation among miRNAs when attempts to discover target sites. To fill this gap, we developed a new approach called CCmiR, which takes the cooperation and competition of multiple miRNAs into account in a statistical model to predict their target sites.

Results

Tested on four different datasets, CCmiR predicted miRNA target sites with a high recall and a reasonable precision, and identified known and new cooperative and competitive miRNAs supported by literature. Compared with three state-of-the-art computational methods, CCmiR had a higher recall and a higher precision.

Availability and implementation

CCmiR is freely available at http://hulab.ucf.edu/research/projects/miRNA/CCmiR.

Supplementary information

Supplementary data are available at Bioinformatics online.
AQUa: an adaptive framework for compression of sequencing quality scores with random access functionality
Authors: Paridaens Tom , Van Wallendael Glenn , De Neve Wesley , Lambert Peter
Published: September 2017

Motivation

The past decade has seen the introduction of new technologies that significantly lowered the cost of genome sequencing. As a result, the amount of genomic data that must be stored and transmitted is increasing exponentially. To mitigate storage and transmission issues, we introduce a framework for lossless compression of quality scores.

Results

This article proposes AQUa, an adaptive framework for lossless compression of quality scores. To compress these quality scores, AQUa makes use of a configurable set of coding tools, extended with a Context-Adaptive Binary Arithmetic Coding scheme. When benchmarking AQUa against generic single-pass compressors, file sizes are reduced by up to 38.49% when comparing with GNU Gzip and by up to 6.48% when comparing with 7-Zip at the Ultra Setting, while still providing support for random access. When comparing AQUa with the purpose-built, single-pass, and state-of-the-art compressor SCALCE, which does not support random access, file sizes are reduced by up to 21.14%. When comparing AQUa with the purpose-built, dual-pass, and state-of-the-art compressor QVZ, which does not support random access, file sizes are larger by 6.42–33.47%. However, for one test file, the file size is 0.38% smaller, illustrating the strength of our single-pass compression framework. This work has been spurred by the current activity on genomic information representation (MPEG-G) within the ISO/IEC SC29/WG11 technical committee.

Availability and implementation

The software is available on Github: https://github.com/tparidae/AQUa.
Linear Recurrences for Cylindrical Networks
Authors: Galashin Pavel , Pylyavskyy Pavlo
Published: September 2017

We prove a general theorem that gives a linear recurrence for tuples of paths in every cylindrical network. This can be seen as a cylindrical analog of the Lindström–Gessel–Viennot theorem. We illustrate the result by applying it to Schur functions, plane partitions, and domino tilings.
Disc origin of broad optical emission lines of the TDE candidate PTF09djl
Authors: Liu F. K. , Zhou Z. Q. , Cao R. , Ho L. C. , Komossa S.
Published: September 2017

An otherwise dormant supermassive black hole (SMBH) in a galactic nucleus flares up when it tidally disrupts a star passing by. Most of the tidal disruption events (TDEs) and candidates discovered in the optical/UV have broad optical emission lines with complex and diverse profiles of puzzling origin. In this Letter, we show that the double-peaked broad H α line of the TDE candidate PTF09djl can be well modelled with a relativistic elliptical accretion disc and the peculiar substructures with one peak at the line rest wavelength and the other redshifted to about 3.5 × 104 km s−1 are mainly due to the orbital motion of the emitting matter within the disc plane of large inclination 88° and pericentre orientation nearly vertical to the observer. The accretion disc has an extreme eccentricity 0.966 and semimajor axis of 340 BH Schwarzschild radii. The viewing angle effects of large disc inclination lead to significant attenuation of He emission lines originally produced at large electron scattering optical depth and to the absence/weakness of He emission lines in the spectra of PTF09djl. Our results suggest that the diversities of line intensity ratios among the line species in optical TDEs are probably due to the differences of disc inclinations.
Establishing Extrapolation Evidence for the MyTIPreport Feedback Application Using a Contemporary Validation Approach
Authors: DeStephano Christopher , Dinh Tri , Seibel Brent , McCullough Deanna , Best Kelly
Published: September 2017

BACKGROUND:

OB/GYN residencies use myTIPreport to improve resident feedback. Validation is viewed as a process with construct validity established from different levels of evidence. In Kane's validity framework, extrapolation focuses on links between assessment outcomes and other measures of performance.

METHODS:

Single-institution, prospective cohort study of OB/GYN residents (n=24). Using the ACGME case log system and myTIPreport application, associations of PGY level, number of previous hysteroscopies (HSC), total vaginal hysterectomies (TVH), and total abdominal hysterectomies (TAH) with myTIPreport ratings of each procedure when performed in the operating room were assessed using Spearman's test correlation. A pilot study of inexpensive, low technology simulation models was initiated to assess extrapolation evidence for myTIPreport in the simulation setting (n=8).

RESULTS:

Associations (P<.01) existed between PGY level and myTIPreport scores in the OR (r=0.612 for HSC, r=0.763 for TAH, r=0.864 for TVH). Associations (P<.01) existed between number of procedures performed and myTIPreport scores in the OR (r=0.587 for HSC, r=0.681 for TAH, r=0.869 for TVH). An association (r=0.852, P=.031) existed between number of TVHs performed in the OR and myTIPreport scores during simulation, but not for TAH (P=.199) nor HSC (P=.154) due to the small sample size.

DISCUSSION:

The association between myTIPreport TVH performance with PGY level and number of TVHs was the strongest, supporting extrapolation evidence. The associations were weaker for TAH and HSC in both the OR and simulation settings secondary to higher ratings for lower PGY levels and fewer cases.
The Impact of a Postpartum Rounding Video Module on Medical Student Learning During the Obstetrics and Gynecology Core Clerkship
Authors: Friedman M. Alexandra , Tarr Lizzie , Has Phinnara , Hampton B. Star
Published: September 2017

BACKGROUND:

The 4C-ID model has been adapted for medical education to help students manage significant cognitive loads while developing strategies for improvement. To date, no 4C-ID intervention exists for the wards or postpartum rounding.

METHODS:

Third-year medical students on the OB-GYN core clerkship who agreed to participate were randomized by clerkship block to receive the 20-minute postpartum rounding video module, or standard education. Knowledge and clinical reasoning were assessed during orientation and clerkship conclusion using a clinical scenario (32 points) and the Diagnostic Thinking Inventory (246 points). Satisfaction was assessed using Likert scale questions (0–5, 5=very satisfied/strongly agree).

RESULTS:

Seventy-eight of 79 eligible students participated. The only significant baseline difference between groups was greater knowledge of physical exam skills in the intervention group (4.8/7, 4.1/7 P=.049). Students in the intervention group demonstrated higher postintervention improvement in knowledge (8.9, 4.5 P=.0011). Both groups increased clinical reasoning, however there was no significant difference between groups pre- or postintervention (160.1, 160.5 P=.92,165.0, 168.8 P=.34). Students in the control group reported a better clerkship experience (3.9, 3.5 P=.04). Students who received the video would recommend the video to their peers (3.7).

DISCUSSION:

A postpartum video based in the 4C-ID model of education increased student knowledge in the 3rd-year medical student OB-GYN core clerkship. Video learning is acceptable to medical students, and can be easily incorporated into specialty rounds at any institution.
Teaching Vaginal Hysterectomy: Low Fidelity Trainer Provides Effective Simulation at Low Cost
Authors: Braun Kelli , Henley Barbara , Ray Chadburn , Stager Robert , Rungruang Bunja
Published: September 2017

BACKGROUND:

Decline in hysterectomies and provider comfort have led to decreased exposure to total vaginal hysterectomy (TVH) during residency training. Commercial simulation products exist but are cost-prohibitive for consistent use in training.

METHODS:

Pilot study of a novel low fidelity TVH trainer. A complete vaginal hysterectomy trainer was modified from previously published models to include vulva (for operating in confined space) and more realistic-feeling materials. Items used included: “pelvic base”- flower pot and board; “vulva”- pink foam cowboy hat; uterine insert (suspended within pelvic base) composed of “uterus”- pool noodle, “uterosacral ligaments”- elastic bands, “round ligament and fallopian tubes”-long balloons, “ovaries”- round balloons, “vessels and ureters”-pipe cleaners, and “peritoneum”- Press'n Seal. Residents rated confidence in performing TVH, pre- and postsimulation with trainer.

RESULTS:

Five reusable pelvic bases ($10/base) and 16 replaceable uterine inserts ($2/insert) were constructed. The trainer functioned well with surgical instruments and suture, although reloading the pelvic base was time consuming. All participating residents (n=14) successfully performed the steps of TVH. Change in mean resident confidence was statistically significant pre- (M=2.08/5) and post- (M=3.17/5) simulation, P=.004.

DISCUSSION:

Our trainer is easily constructed for minimal cost. It can be used in residency training programs to simulate total vaginal hysterectomy and improve resident confidence in performing TVH. We have since updated the base to a flip-top trashcan to facilitate reloading.
Senior Obstetrician Supervision Improves Resident Labor and Delivery Rotation Experience
Authors: Bardos Jonah , Fox Nathan , Loudon Holly , Rekawek Patricia , Brodman Michael , Wagner Brian
Published: September 2017

BACKGROUND:

In December 2012, the Mount Sinai Hospital implemented a program to have senior obstetricians, with experience in forceps-assisted vaginal delivery, supervise residents on labor and delivery during the day hours. The objective of this study was to estimate the effect of this program on resident satisfaction with the Labor and Delivery rotation.

METHODS:

This was a retrospective cohort study from July 2011 to June 2015. We compared resident satisfaction prior to and after December 2012 using Student's t test. Over the course of the study period, residents were routinely surveyed regarding their rotation experience. Each rotation block was 6 weeks for the PGY-1, and 7 weeks for PGY-2 and PGY-4 residents who rotated. Surveys were sent anonymously through an online program. Surveys consisted of eight questions (scaled 1–5) including whether the rotation fostered development of relevant medical knowledge, an improvement in physical examination skills, whether the rotation improved residents’ ability to manage relevant problems and the overall quality of the educational experience.

RESULTS:

Ninety-four percent of the residents completed the rotation evaluations. Comparing responses prior to and after December 2012, resident overall satisfaction for the rotation significantly improved (2.3–4.2, P<.05), with increased reporting of meeting the intended goals and objectives in the senior level residents (2.1–4.7, P<.05). Additionally, PGY-1 residents reported a significant increase in their physical exam skills (2.0–4.1, P<.05) and the ability to formulate a differential diagnosis (2.1–4.0, P<.5). After December 2012, there was a significant increase in forceps deliveries among residents from 0.6% to 2.6% of all deliveries (aOR 8.41, 95% CI 3.1, 23.0).

DISCUSSION:

Implementing a program with senior obstetrician supervision of residents on Labor and Delivery significantly increases the resident satisfaction and overall educational experience. This may be partly due to increased training in operative deliveries. Our data suggest that a small change in resident supervision can have a major impact on resident education.
A Comparative Analysis Using Endoscopic Simulation to Assess Surgical Skill of OB/GYN Residents
Authors: Duarte Jhonathan , Patruno Joseph , Pellini Timothy , Martino Martin , Corsi Taylor , Bonner Shannon
Published: September 2017

BACKGROUND:

Endoscopic skill curriculums using simulation tools have proven to be efficacious in training and in evaluating competency in residents performing endoscopic procedures. OB/GYN residents in a single institution were evaluated using various modalities in the simulation setting. There are few data on the value of endoscopic simulation in assessing efficiency, dexterity, and technical ability and how it compares with actual OR performance of trainees.

METHODS:

This study was a prospective, observational study, assessing skill in simulation exercises in hysteroscopy, laparoscopy, and robotics. Performance results were compared to surgical experience based on residents' OPLOG data, NewInnovation surgical evaluation scores, and endoscopy-specific milestone assessment. The study included all OB/GYN residents from a single training program. Testing was performed in 11 different exercises using simple box trainers and computer simulators for laparoscopy (Symbionix) and robotics (Mimic). Scoring included time, with alteration for errors or dangerous movements, and efficiency based on path of motion.

RESULTS:

When comparing PGY year versus total time, the average total time decreased as PGY level increased for all exercises except for the Symbionix laparoscopic trainer. This trend was also consistent for efficiency and motion metrics. These performance metrics were also better in residents who had completed a larger number of actual operative procedures. Resident performance in the simulated setting, however, did not correlate well with prior surgical evaluations or endoscopic milestone assessments.

DISCUSSION:

Implementation of a multimodal simulation curriculum focused on endoscopic procedures could provide a safe, and objective means than may be used to evaluate endoscopic performance of residents. Performance on simple skill correlates positively with level of training and prior experiential numbers. There was little correlation between resident performance and past resident surgical evaluations used in our institution. Based on these data, we are considering surgical evaluation paradigm that combines both simulation and actual procedural performance metrics.
An 8-Week Mindfulness-Based Stress Reduction Course for Ob/Gyn Residents: A Pilot Study
Authors: Cavanaugh Erin , Rose Marisa
Published: September 2017

BACKGROUND:

Studies have linked improved physician well-being with better patient outcomes. Despite the documentation of growing job dissatisfaction, burnout, and depression among OBGYN residents, few interventions have been studied. Mindfulness-based stress reduction (MBSR) has been shown to significantly improve personal well-being and job satisfaction in primary care specialties, but has not been investigated in obstetrics and gynecology.

METHODS:

An 8-week MBSR course specifically designed for medical professionals was created and led by a certified Mindfulness Teacher. Participants completed a pre- and postintervention survey measuring burnout, anxiety, mindfulness, resilience, stress, and depression by validated scales. McNemar's test was used to assess changes in outcome measures.

RESULTS:

All 21 of the eligible residents participated in four or more of the eight weekly 1-hour lectures. At the 2-month postintervention survey, participants demonstrated statistically significant improvements in stress, anxiety, and focus. Residents showed no statistical improvement in depression or burnout scores.

DISCUSSION:

Our pilot study demonstrated that an 8-week MBSR course was associated with improvements in some but not all measured outcomes of burnout, mindfulness, resilience, stress, and depression. We are currently piloting a reformatted course with shortened but more frequent programs to support and improve the well-being of our residents.
Avoiding Poison Apples in the Land of Tomorrow: Patient Satisfaction With Residents Versus Non-Physician Providers in an Obstetrics and Gynecology Academic Medical Center Practice
Authors: Dade Adrianne , Blanchard Anita , Young Danielle , Kupfer Rachel
Published: September 2017

BACKGROUND:

Non-physician providers (NPPs) [physician assistants (PAs), nurse practitioners (APNs), and certified nurse midwives (CNMs)] may be used to supplement duties traditionally filled by Obstetrics & Gynecology (OB/GYN) residents. NPPs provide high level of care and may help protect resident time without compromising patient satisfaction.

METHODS:

Patients attended to for the majority of their appointments by either NPPs or residents were anonymously surveyed about satisfaction with their health care provider. The survey had 15 questions and was developed in conjunction with a professional survey lab at the University of Chicago. The study was sufficiently powered (80%) to detect equivalency of up to 2.2 points in average scores (out of possible 38) between the NPP and resident group.

RESULTS:

One hundred sixty-nine total patients were surveyed (resident=103, NPP=66). Patients seen by NPPs were younger (P<.001) and more often seen for obstetric or postpartum care (P<.001) compared to patients seen by residents. There was no difference (P=.48) in overall patient satisfaction if seen by an NPP (mean score: 35.21±4.40) or resident (mean score: 34.72±4.08). Small differences were detected in individual questions. A higher proportion of patients reported having all their questions answered by NPPs (100%) than by residents (93.94%) (P=.05) and a slightly higher proportion of patients reported having a “fair amount” or “a lot” confidence in NPPs (98.48%) versus residents (91.26%) (P=.04).

DISCUSSION:

Patients were equally satisfied with NPP and resident providers.