bluuebunny/crossref_metadata_2025 huggingface dataset:
Dam-break on an idealised hill side: Preliminary results of a physical model
Authors: Cordero Silvia , Cagninei Andrea , Poggi Davide
Published: September 2018

The aim of this work is to study the propagation of dam-break waves along a hillslope by mean of a physical model (basically i.e. a 3 x 4 m2 plane set downstream of a reservoir) build up in the Hydraulic Laboratory of the Politecnico di Torino. We want to recreate the water surface, to assess the shape of the flooded area and the arrival time of the wave front. The measurement facility is a high resolution CMOS camera. We measure the water height by linking the intensity of the pixels in the acquired images to the real water depth. Preliminary quantitative results are given for the 0°downstream-slope scenario and qualitative results are presented for the case of downstream inclined plane.
Bedload transport and hydro-abrasive erosion at steep bedrock rivers and hydraulic structures
Authors: Mueller-Hagmann Michelle , Auel Christian , Albayrak Ismail , Boes Robert M.
Published: September 2018

Sediment transport in glacier basins and rivers, and hence reservoir sedimentation tend to increase under the impact of climate change. The raise of bedload transport rates results in an increase of hydro-abrasive erosion leading to bedrock incision in rivers and wear at hydraulic structures. Mechanistic abrasion models are a helpful tool for both river and landscape evolution and hydroabrasion of hydraulic structures. Therefore, knowledge of the physical processes of turbulent flow characteristics, bedload particle motion, and hydroabrasion and their interrelations is needed. Ongoing research at VAW of ETH Zurich aims at improving the required knowledge to address hydroabrasion issues by means of laboratory and prototype experiments in supercritical flows over fixed smooth and transitionally rough beds. A physical model investigation revealed that particle trajectories on fixed planar beds are rather symmetric, flat and long compared to alluvial beds. By applying newly developed particle motion equations, an existing mechanistic abrasion model was adapted and calibrated for concrete and natural rock by means of prototype data. This advances abrasion prediction modelling and contributes to a better understanding of river bed and landscape evolution and to a sustainable design and operation of hydraulic structures facing severe hydro-abrasive erosion.
2D numerical simulation of meander morphology
Authors: Banda Mohd. Sarfaraz , Niewerth Stephan , Aberle Jochen
Published: September 2018

This paper describes the application of the two-dimensional (2D) modelling approach implemented in the open-source code Delft3D for the simulation of morphological development of a natural meandering river. A specific reach of the Dhaleshwari River (Bangladesh) for which field data has been available served as case study. The bed morphology and meander planform adjustment in the study area were simulated over a 10-year period considering a time-varying discharge scenario. The results showed that the 2D model was able to reproduce morphological characteristics such as scour depth, bank erosion and pool-riffle morphology, even though the model showed some deficiencies to reproduce bankfull channel width and transverse bed slopes. Regarding the planimetric evolution, the planform parameters (i.e., meander belt width, meander wavelength and radius of curvature) confirmed that the model results are realistic and are in agreement with results reported in the literature.
IDDES Evaluation of Oscillating Hydraulic Jumps
Authors: Jesudhas Vimaldoss , Murzyn Frédéric , Balachandar Ram
Published: September 2018

This paper presents the results of three-dimensional, unsteady, Improved Delayed Detached Eddy Simulations of an oscillating and a stable hydraulic jump at Froude numbers of 3.8 and 8.5, respectively. The different types of oscillations characterised in a hydraulic jump are analysed by evaluating the instantaneous flow field. The instability caused by the flapping wall-jet type flow in an oscillating jump is distinct compared to the jump-toe fluctuations caused by the spanwise vortices in the shear layer of a stable jump. These flow features are accurately captured by the simulations and are presented with pertinent discussions. The near-bed vortical structures in an oscillating jump is extracted and analysed using the λ2 criterion.
Comparison of velocity and turbulence profiles obtained with a Vectrino Profiler and PIV
Authors: Lacey Jay , Duguay Jason , MacVicar Bruce
Published: September 2018

Laboratory experiments were carried out in a small openchannel hydraulic flume at the Université de Sherbrooke. A PIV and an acoustic Doppler velocity profiler (Vectrino II (VII)) were used to measure high frequency velocities in profiles along the centreline of a small openchannel flume. Two background turbulence levels were tested. Comparisons were made of mean and turbulent statistics obtained with the two measurement techniques. The results show reasonable agreement between mean streamwise and lateral velocities measured with the PIV and VII near the “sweet spot” of the VII. In contrast, mean vertical velocities deviate substantially between the two measurement methods. Turbulence statistics have somewhat similar profile shapes, yet significant bias is observed between the two measurement methods.
Interpolation of water surface profile in unsteady open channel flow using the adjoint method based on 2D shallow water equations
Authors: Watanabe Akihide , Kojima Takashi , Mikami Tetsuaki , Matsunobu Kazuhiko , Suzuta Hiromi , Tomizawa Shinjiro
Published: September 2018

Real-time interpolation of high-water stage data obtained at separate water gauges was investigated to provide visual information for evacuation decision-making by residents near a river. The adjoint method was applied to a set of shallow water equations in a generalized coordinate system in which the hydraulic effect of tree communities is included as semi-permeable blocks. The cost function to be minimized was assumed as the summation of four misfits for water level and discharge from observation and for Manning's roughness (n) and tree community permeability (K) from standard values. The Lagrange multipliers method was adopted to determine the uncertain quantities, upstream discharge and spatial distributions of n and K, for minimizing the total cost under the constraint of the shallow water equations. The method was applied to a flood event observed in 2011 over a 20-km reach of the Tone River, where four water gauges are installed. The computation results successfully explained the time series of river discharge observed at stations located in the river reach, as well as the longitudinal profile of the trace water levels measured at 500-m intervals just after the flood event.
A micromechanical scratch model to investigate wear mechanisms in UD-GFRP composites
Authors: Mzali Slah , Elwasli Fatma , Mkaddem Ali , Mezlini Salah
Published: September 2018

This study suggests a micromechanical approach to scrutinize the glass fiber reinforced polyester (GFRP) composite tribological behavior. A single indenter scratch test (SST) using spherical tip conical indenter was adopted. The 3D finite element (FE) model was developed into ABAQUS/Explicit commercial code. Both material behavior and damage of polyester matrix and glass fiber was modeled using the Johnson Cook behavior law. Nevertheless, the fiber/matrix interface behavior is described using the cohesive zone approach via the cohesive elements. The elementary wear mechanisms owing to the SST were appraised at different attack angle and normal load by the mean of scanning electron microscope (SEM). In this work, the material removal map was built to emphasize the correlation between the tribological parameters, particularly the attack angle and the normal load, and the material removal process. The numerical results emphasized the significant effects of the attack angle and the penetration depth on the transition of the wear mechanisms from ploughing to composite damage. The experimental wear mechanisms and the predicted elementary wear mechanisms seem to be in a good agreement.
On the star forest polytope for trees and cycles
Authors: Aider Meziane , Aoudia Lamia , Baïou Mourad , Mahjoub A. Ridha , Nguyen Viet Hung
Published: September 2018

Let G = (V, E) be an undirected graph where the edges in E have non-negative weights. A star in G is either a single node of G or a subgraph of G where all the edges share one common end-node. A star forest is a collection of vertex-disjoint stars in G. The weight of a star forest is the sum of the weights of its edges. This paper deals with the problem of finding a Maximum Weight Spanning Star Forest (MWSFP) in G. This problem is NP-hard but can be solved in polynomial time when G is a cactus [Nguyen, Discrete Math. Algorithms App. 7 (2015) 1550018]. In this paper, we present a polyhedral investigation of the MWSFP. More precisely, we study the facial structure of the star forest polytope, denoted by SFP(G), which is the convex hull of the incidence vectors of the star forests of G. First, we prove several basic properties of SFP(G) and propose an integer programming formulation for MWSFP. Then, we give a class of facet-defining inequalities, called M-tree inequalities, for SFP(G). We show that for the case when G is a tree, the M-tree and the nonnegativity inequalities give a complete characterization of SFP(G). Finally, based on the description of the dominating set polytope on cycles given by Bouchakour et al. [Eur. J. Combin. 29 (2008) 652–661], we give a complete linear description of SFP(G) when G is a cycle.
Stents und Platzhalter in der endoskopischen endonasalen
Nasennebenhöhlenchirurgie
Authors: Hosemann Werner , Kühnel Thomas , Weber Rainer
Published: September 2018

In der endonasalen endoskopischen Chirurgie kam es im letzten Jahrzehnt zu
Fortschritten durch ein verbessertes Verständnis der Mikroanatomie, den Zugewinn
additiver medikamentöser Therapieoptionen und die Optimierung der
instrumentellen Technik. In den gleichen Kontext kann die Weiterentwicklung und
Beforschung röhrenförmiger oder solider Platzhalter („stents“ oder „spacer“) mit
und ohne simultane Freisetzung von Medikamenten gestellt werden – der
vorliegende Übersichtsbeitrag stellt den aktuellen Stand dieser Entwicklungen
vor.
Der Weg zur richtigen Diagnose
Authors: Hörber Sebastian , Peter Andreas
Published: September 2018

Labormedizinische Bestimmungen spielen eine entscheidende Rolle bei der Diagnose, Therapiekontrolle und Prognoseeinschätzung des Diabetes mellitus. Bestimmt werden können Nüchternplasmaglukose, Gelegenheitsplasmaglukose, 2h-Plasmaglukose und der HbA1c-Wert. Dabei ist es wichtig die Vor- und Nachteile der verschiedenen Methoden zu kennen.
Occult Placenta Accreta: Risk Factors, Adverse Obstetrical Outcomes, and Recurrence in Subsequent Pregnancies
Authors: Mullen Clodagh , Battarbee Ashley , Ernst Linda , Peaceman Alan
Published: September 2018

Objective To assess the risk factors, adverse obstetrical outcomes, and recurrence risk associated with pathologically diagnosed occult placenta accreta.

Study Design This was a retrospective observational study of clinically adherent placentas requiring manual extraction that underwent pathological examination. Cases were defined as those with histological evidence of placenta accreta, and controls were defined as those without accreta. All subsequent pregnancies were evaluated to determine the recurrence risk of occult accreta in future pregnancies.

Results Of 491 women with clinically adherent placentas, 100 (20.1%) with a pathological diagnosis of occult accreta were compared with 391 (79.9%) without occult accreta. In bivariable analysis, risk factors associated with occult accreta included a history of previous cesarean (19 vs. 10.7%; p = 0.03) and prior uterine surgery (35 vs. 19.7%; p = 0.001). Adverse obstetrical outcomes were more common in women with occult accreta including postpartum hemorrhage (59 vs. 31.7%; p < 0.001) and peripartum hysterectomy (21 vs. 0.3%; p < 0.001). In 130 subsequent pregnancies, there was an increased risk of retained placenta (42.9 vs. 19%; p = 0.04) and recurrence of occult accreta (29.6 vs. 6.8%; p = 0.05).

Conclusion Occult accreta is associated with an increased risk of hemorrhagic morbidity and recurrence of morbidly adherent placenta in subsequent pregnancies.
Comparison of Lamb wave focusing performance using wave dispersion-compensated actuation and plano-concave lenses
Authors: Kudela Pawel , Ostachowicz Wieslaw
Published: September 2018

Lamb waves are often used for damage detection in structures. Hot-spot monitoring via wave focusing is considered in this study, which can be achieved by using a plano-concave aspherical lens. Once attached to the plate, the lens modifies the effective plate thickness, and therefore changes the Lamb wave characteristics, such as wavenumber and phase velocity, providing a convenient way of controlling Lamb waves. Another possibility for focusing Lamb waves is to use multiple actuators and design dispersion pre-compensated excitation signals with an embedded time delay. These two approaches can be combined together. We conducted numerical simulations using the time-domain spectral element method based on the 3D elasticity theory and demonstrated that the A0 mode of Lamb waves could be focused on the desired focal point. We compared the efficacies of the plano-concave lens approach, the dispersion pre-compensated focusing approach, and a combination of both approaches, emphasizing the advantages and disadvantages of each method.
Efficient lattice constants and energy bandgaps for condensed systems from a meta-GGA level screened range-separated hybrid functional
Authors: Jana Subrata , Patra Abhilash , Samal Prasanjit
Published: September 2018

A meta-generalized gradient approximation (meta-GGA) level screened hybrid functional is developed for the solid-state electronic structure calculations. Assessment of the proposed functional for the solid-state lattice constants and bandgaps indicates that it is quite efficient in describing those properties. Specifically, the improvement in the bandgap performance of the presently proposed meta-GGA level screened hybrid functional is noticeable. From the construction point of view, the present screened hybrid functional is one step forward to the density functional screened hybrid functional rung by adding extra ingredients in its functional form. The most appealing feature of the present screened functional is that it is constructed upon an accurate semilocal functional by adopting a simple modification on the top of that functional.
An electrostatic method to model the expansion of hypervelocity impact plasma on positively biased surfaces
Authors: Tarantino P. , Goel A. , Corso A. , Lee N. , Close S.
Published: September 2018

Spacecraft are a major component of infrastructure and are essential to modern society. Though launch opportunities are expected to become less expensive and more frequent through commercial launch providers, spacecraft design, manufacturing, and deployment processes are far from routine. In addition, a spacecraft's operational environment is riddled with numerous hazards that may jeopardize its performance, and with a cost to orbit of $10 000 per pound, there is a desire to protect our space assets and mitigate against damage. Meteoroids and orbital debris, which are components of the space environment, are two such threats to space vehicles. While larger objects endanger spacecraft mechanically, collisions are rare; however, bodies with masses smaller than a milligram impact frequently and at speeds up to 72.8 km s−1 if in solar orbit. Shortly after contact, projectile and spacecraft materials vaporize and ionize, resulting in an expanding plasma that may interfere with onboard sensors and equipment. These hypervelocity impacts have potentially been the source of unexplained electronic anomalies through arc discharge and electromagnetic emission mechanisms. To better understand the plasma structure, hypervelocity impact experiments were conducted at the Max Planck Institute for Nuclear Physics in Heidelberg, Germany. Using their Van de Graaff dust accelerator and vacuum chamber, iron dust particles impacted typical spacecraft material targets with surface potentials ranging from –1000 V to +1000 V, representing charging conditions experienced in orbit. During this experiment, a suite of sensors measured impact plasma properties; among these sensors are two distinct arrays of charge collecting plates, termed Faraday plate arrays, positioned to describe the plasma's range and azimuthal distributions. The work discussed here presents a multi-species plasma expansion model and compares its results to those obtained experimentally. The particle model uses a tree structure to reduce computational complexity. The agreement between the simulated output and the sensor measurements provides confidence in the model's ability to replicate the plume accurately. Consequently, the model is used to provide initial plasma temperature and bulk expansion speed estimates, to explore the sensitivity of our measurements to shifts in sensor position, and to identify potentially hazardous regions on spacecraft.
Band structure and absorption properties of (Ga, In)/(P, As, N) symmetric and asymmetric quantum wells and super-lattice structures: Towards lattice-matched III-V/Si tandem
Authors: Kharel K. , Freundlich A.
Published: September 2018

Quaternary dilute nitride compound semiconductors like GaAsyP1−x−yNx and Ga1−zInzP1−xNx are lattice matched with silicon when y = 4.7 * x − 0.1 and z = 2.2 * x − 0.044 and also have direct bandgaps (with N > 0.6%), thus allowing for monolithic integration of III-V optoelectronics with silicon technology as well as III-V/Si tandem junction solar cells. By applying an eight-band k.p strained (tensile or compressive) Hamiltonian and a Band Anti-crossing model (to account for small amounts of nitrogen impurities) to the conduction band, the electronic band structure and the dispersion relation of these alloys can be determined near the center of Brillouin Zone. In this work, by minimizing the total mechanical energy of the stack of alternating layers of GaP1−xNx and GaAs1−xNx, we have evaluated the ratio of thickness of the respective layers for a strain-balanced superlattice GaAs1−xNx/GaP1−xNx structure on silicon. We calculated the confinement energies and the corresponding states of the respective carriers inside a quantum well (with and without resonantly coupled) or in the miniband of a superlattice structure as a function of the nitrogen composition using a transfer matrix approach under the envelope function approximation. Incorporating only a small amount of nitrogen (<5%), the bandgap of these lattice matched structures fulfils the optimum bandgap requirement of (1.65–1.8) eV for III-V/Si tandem solar cells and optoelectronic devices. The optical-absorption coefficient, in both symmetric and asymmetric quantum wells, is then evaluated with respect to nitrogen composition and temperature by using the Fermi-golden rule for both TE and TM polarization of incident light, including the effect of excitons and thermal broadening.
Note: Simultaneous water quality monitoring and degradation of hazardous organic pollutants
Authors: Solanki Vanaraj , Krupanidhi S. B. , Nanda K. K.
Published: September 2018

Here, we report a simple technique that uses mesoporous SnO2 to monitor the water quality and degrade the hazardous organic pollutants simultaneously. The technique generates hydroxyl radicals and a voltage that is hindered by the presence of hazardous organic pollutants. Pollutant as low as 1 ppb concentration level can easily be detected. The developed system not only monitors the water quality but also is capable of degrading hazardous dyes (organic pollutants) through its self-power, not relying on any external stimuli such as light, heat, radiation, and current. A simple digital laboratory multimeter is shown to be useful for the overall study. Overall, the study indicates that spectrophotometer generally used to monitor the dye concentration can be avoided.
Viscosity and self-diffusion of supercooled and stretched water from molecular dynamics simulations
Authors: Montero de Hijes Pablo , Sanz Eduardo , Joly Laurent , Valeriani Chantal , Caupin Frédéric
Published: September 2018

Among the numerous anomalies of water, the acceleration of dynamics under pressure is particularly puzzling. Whereas the diffusivity anomaly observed in experiments has been reproduced in several computer studies, the parallel viscosity anomaly has received less attention. Here we simulate viscosity and the self-diffusion coefficient of the TIP4P/2005 water model over a broad temperature and pressure range. We reproduce the experimental behavior and find additional anomalies at negative pressure. The anomalous effect of pressure on dynamic properties becomes more pronounced upon cooling, reaching two orders of magnitude for viscosity at 220 K. We analyze our results with a dynamic extension of a thermodynamic two-state model, an approach which has proved successful in describing experimental data. Water is regarded as a mixture of interconverting species with contrasting dynamic behaviors, one being strong (Arrhenius) and the other fragile (non-Arrhenius). The dynamic parameters of the two-state models are remarkably close between experiment and simulations. The larger pressure range accessible to simulations suggests a modification of the dynamic two-state model, which in turn also improves the agreement with experimental data. Furthermore, our simulations demonstrate the decoupling between viscosity η and self-diffusion coefficient D as a function of temperature T. The Stokes-Einstein relation, which predicts a constant Dη/T, is violated when T is lowered, in connection with the Widom line defined by an equal fraction of the two interconverting species. These results provide a unifying picture of thermodynamics and dynamics in water and call for experiments at negative pressure.
Identifying complex Fermi resonances in p-difluorobenzene using zero-electron-kinetic-energy (ZEKE) spectroscopy
Authors: Kemp David J. , Gardner Adrian M. , Tuttle William D. , Midgley Jonathan , Reid Katharine L. , Wright Timothy G.
Published: September 2018

The vibrations of the ground state cation (X̃2B2g) of para-difluorobenzene (pDFB) have been investigated using zero-electron-kinetic-energy (ZEKE) spectroscopy. A comprehensive set of ZEKE spectra were recorded via different vibrational levels of the S1 state (<00 + 1300 cm−1). The adiabatic ionization energy for pDFB was measured as 73 869 ± 5 cm−1. Use of different intermediate levels allows different cationic vibrational activity to be obtained via the modification of the Franck-Condon factors for the ionization step, allowing the wavenumbers of different vibrational levels in the cation to be established. In addition, assignment of the vibrational structure in the ZEKE spectra allowed interrogation of the assignments of the S1 ← S0 transition put forward by Knight and Kable [J. Chem. Phys. 89, 7139 (1988)]. Assignment of the vibrational structure has been aided by quantum chemical calculations. In this way, it was possible to assign seventeen of the thirty vibrational modes of the ground state pDFB+ cation. Evidence for complex Fermi resonances in the S1 state, i.e., those that involve more than two vibrations, was established. One of these was investigated using picosecond time-resolved photoelectron spectroscopy. In addition, we discuss the appearance of several symmetry-forbidden bands in the ZEKE spectra, attributing their appearance to a Rydberg state variation of an intrachannel vibronic coupling mechanism.
Tuning the optical properties of InAs QDs by means of digitally-alloyed GaAsSb strain reducing layers
Authors: Salhi A. , Alshaibani S. , Alaskar Y. , Albadri A. , Alyamani A. , Missous M.
Published: September 2018

In this work, we demonstrate the use of a digitally alloyed GaAsSb as a strain reducing layer (SRL) to tune the optical properties of InAs quantum dots grown on GaAs substrates. The GaAsSb digital alloy was made using a short period GaAs/GaSb superlattice. Increasing the Sb-shutter duty cycle (Sb-SDC) from 0 to 0.35 redshifts the emission wavelength from 1220 nm to 1492 nm at 300 K. The wavelength red shift is attributed mainly to the increased Sb content in the GaAsSb SRL as confirmed by high resolution X-ray diffraction. Power dependent photoluminescence showed a type II band alignment for the samples grown with a Sb-SDC of 0.25 and 0.35. Reversing the growth order of GaAs and GaSb layers and maintaining the same Sb-SDC (0.25) drastically alters the optical properties of the QDs. A large wavelength blue shift of 143 nm and a transformation from a type II to type I emission were observed as a result of GaSb intermixing with InAs QDs.
Investigation of the crystal structure and cryogenic magnetic properties of RE2T2Al (RE = Dy, Ho, Er, and Tm; T = Co and Ni) compounds
Authors: Dong Xiaoshi , Feng Jing , Yi Yalin , Li Lingwei
Published: September 2018

The crystal structure, and cryogenic magnetic and magnetocaloric properties in RE2T2Al (RE = Dy, Ho, Er, and Tm; T = Co and Ni) compounds have been investigated. All the compounds belong to an orthorhombic W2B2Co-type structure (Immm space group). A second order paramagnetic to ferromagnetic phase transition exists for RE2Co2Al compounds at TC = 62, 27, 32, and 11.5 K, whereas the compounds of RE2Ni2Al undergo a paramagnetic to antiferromagnetic phase transition with the Néel temperatures (TN) of 19, 12, 12.5, and 6 K for RE = Dy, Ho, Er, and Tm, respectively. Moreover, an additional low temperature magnetic transition occurs for all present RE2T2Al compounds. An obvious hysteresis was observed at a low temperature in the Dy2Co2Al, Ho2Co2Al, and Er2Co2Al compounds. The values of the maximum magnetic entropy change (−ΔSMmax) are 10.4, 11.5, 5.9, 7.7, 6.0, and 16.2 J/kg K for Dy2Co2Al, Ho2Co2Al, Er2Co2Al, Tm2Co2Al, Ho2Ni2Al, and Er2Ni2Al compounds with a field change (ΔH) of 0-5 T, respectively. Moreover, two peaks (or shoulder) in the −ΔSM (T) curves of Ho2Co2Al can be observed, which lead to a wide cooling temperature interval.
Magnetoelectric coupling and the manipulation of magnetic Bloch skyrmions
Authors: Wang Zidong , Ma Zhao , Grimson Malcolm J.
Published: September 2018

Chiral-magnetic/ferroelectric composite systems offer the possibility of electrically inducing magnetic Bloch skyrmions [Wang and Grimson, Phys. Rev. B 94, 014311 (2016)]. They are appealing for potential applications in spintronics due to their self-protection behavior. To realize skyrmion-based spintronic devices, it is essential to control the motions of the skyrmions. In this work, we propose a mechanical technique to manipulate skyrmions collinearly with a mobile external electric field that is imposed on the chiral-magnetic/ferroelectric system. The role of propagation velocity strongly impacts on the quality of magnetic skyrmions.
Linking economic growth pathways and environmental sustainability by understanding development as alternate social–ecological regimes
Authors: Cumming Graeme S. , von Cramon-Taubadel Stephan
Published: September 2018

Significance

Our analysis shows that there are two distinct groups of national economies, roughly equating to developed and less developed countries. The economies of countries in each group are pushed toward two different equilibrium points by differences in the feedbacks between natural resource consumption, population growth, and gross domestic product. Both equilibrium points are unsustainable under population growth. The inertia that is generated by resource dependence means that extensive structural change in the economic system is required to achieve sustainable use of natural resources; it is not possible to “develop to sustainability,” and many developed countries have simply externalized costs. Our results have profound implications for aid programs, human wellbeing, and development goals.
On orthogonal hypergeometric groups of degree five
Authors: Bajpai Jitendra , Singh Sandip
Published: September 2018

A computation shows that there are

77
77

(up to scalar shifts) possible pairs of integer coefficient polynomials of degree five having roots of unity as their roots and satisfying the conditions of Beukers and Heckman, so that the Zariski closures of the associated monodromy groups are either finite or the orthogonal groups of non-degenerate and non-positive quadratic forms. Following the criterion of Beukers and Heckman, it is easy to check that only

4
4

of these pairs correspond to finite monodromy groups, and only

17
17

pairs correspond to monodromy groups, for which the Zariski closure has real rank one.

There are

56
56

pairs remaining, for which the Zariski closures of the associated monodromy groups have real rank two. It follows from Venkataramana that

11
11

of these

56
56

pairs correspond to arithmetic monodromy groups, and the arithmeticity of

2
2

other cases follows from Singh. In this article, we show that

23
23

of the remaining

43
43

rank two cases correspond to arithmetic groups.
The use, quality and effectiveness of pelvic examination in primary care for the detection of gynaecological cancer: a systematic review
Authors: Williams Pauline , Murchie Peter , Cruickshank Maggie E , Bond Christine M , Burton Christopher D
Published: September 2018

Background

Urgent suspected cancer referral guidelines recommend that women with gynaecological cancer symptoms should have a pelvic examination (PE) prior to referral. We do not know to what extent GPs comply, their competency at PE, or if PE shortens the diagnostic interval.

Objectives

We conducted a systematic review of the use, quality and effectiveness of PE in primary care for women with suspected gynaecological cancer.

Method

PRISMA guidelines were followed. Three databases were searched using four terms: PE, primary care, competency and gynaecological cancer. Citation lists of all identified papers were screened independently for eligibility by two reviewers. Data extraction was performed in duplicate and independently. Paper quality was assessed using the relevant Critical Appraisal Skills Programme checklist. Emergent themes and contrasting issues were explored in a narrative ecological synthesis.

Main Findings

Twenty papers met the inclusion criteria. 52% or less of women with suspicious symptoms had a PE. No papers directly explored GPs’ competence at performing PE. Pre-referral PE was associated with reduced diagnostic delay and earlier stage diagnosis. Ecological synthesis demonstrated a complex interplay between patient and practitioner factors and the environment in which examination is performed. Presenting symptoms are commonly misattributed by patients and practitioners resulting in misdiagnosis and lack of PE.

Conclusion

We do not know if pre-referral PE leads to better outcomes for patients. PE is often not performed for women with gynaecological cancer symptoms, and evidence that it may result in earlier stage of diagnosis is weak. More research is needed.
ChIPprimersDB: a public repository of verified qPCR primers for chromatin immunoprecipitation (ChIP)
Authors: Kurtenbach Stefan , Reddy Rohit , Harbour J William
Published: September 2018

Chromatin immunoprecipitation (ChIP) has ushered in a new era of scientific discovery by allowing new insights into DNA-protein interactions. ChIP is used to quantify enriched genomic regions using qPCR, and more recently is combined with next generation sequencing (ChIP-seq) to obtain a genome wide profile of protein binding sites. Nevertheless, ChIP-qPCR remains an integral component of this technology for quality control purposes, before the library preparation and sequencing steps. In addition, ChIP-qPCR remains more time- and cost-effective for many focused projects in which the DNA regions of interest are already known. However, the DNA oligonucleotide primers needed for ChIP-qPCR are more challenging to design than for other qPCR projects. Here, we present the first public repository for ChIP oligonucleotides that have been verified to perform well in ChIP-qPCR experiments. ChIPprimersDB was developed by manual screening of publications to ensure primer quality and provide additional specific information on the ChIP experiments where the primers have been used. In addition to the primer sequences, the database includes information about the antibody, cells and tissues used in the experiment, information on the experimental design, and a direct link to the original publication. The database is linked at https://umiamihealth.org/bascom-palmer-eye-institute/research/laboratory-research/ocular-oncology-laboratory/chip-primers and hosted at https://www.chipprimers.com/.
Phosphorylation of E‐box binding USF‐1 by PI3K/AKT enhances its transcriptional activation of the WBP2 oncogene in breast cancer cells
Authors: Ramos Alisha , Miow Qing Hao , Liang Xu , Lin Qing Song , Putti Thomas Choudary , Pin Lim Yoon
Published: September 2018

WW domain binding protein 2 (WBP2), a transcriptional coactivator, plays a vital role in breast tumori‐ genesis. It positively regulates estrogen receptor, Hippo, and Wnt pathways, which subsequently enhance the transcription of downstream target genes contributing to cancer. Understanding the regulation of the expression and activity of WBP2 oncoprotein has implication in cancer therapy. We have previously reported that WBP2 is regulated at the post‐translational and post‐transcriptional levels. However, its regulation at the transcriptional level is not known. In this study, the minimal promoter region of WBP2 that is critical for its transcription was identified. The E‐box motif in the WBP2 promoter was demonstrated to be essential for its transcription. The E‐box binding protein upstream stimulatory factor 1 (USF‐1) was discovered to be a key transcription factor for WBP2 by yeast one‐hybrid analysis and was validated through reporter and chromatin immunoprecipitation assays and tandem mass spectrometry, which also suggested that USF‐1 acts by regulating a network of genes, in addition to WBP2, associated with cell movement, proliferation, cell‐cycle, and survival cellular processes. USF‐1 is overexpressed in majority of the breast cancer cell lines and tissues tested, and has profound effects on cancer cell proliferation. USF‐1‐mediated transcription of WBP2 was demonstrated to be inducible by insulin, which led to AKT‐mediated phosphorylation of USF‐1 that modulated its ability to bind to the WBP2 promoter and activate its transcription. This study sheds new light onto the regulation of the WBP2 oncogene at the transcriptional level by a novel oncogenic transcription factor, USF‐1. USF‐1 is a potential drug target for treatment of WBP2‐positive breast cancer.—Ramos, A., Miow, Q. H., Liang, X., Lin, Q. S., Putti, T. C., Lim, Y. P. Phosphorylation of E‐box binding USF‐1 by PI3K/AKT enhances its transcriptional activation of the WBP2 oncogene in breast cancer cells. FASEB J. 32, 6982–7001 (2018). www.fasebj.org
What is new in HIES? Recent insights from the interface of primary immune deficiency and atopy
Authors: Ponsford Mark J. , Rae William , Klocperk Adam
Published: September 2018

Purpose of review

Understanding the pathophysiology of monogenic primary immunodeficiency (PID) with atopic presentation has pivotal implications for intervention strategies and potentially wider polygenic atopic-related traits. This review will discuss advances in gene discovery arising from monogenic defects at the interface between PID and atopy, notably the hyper-IgE syndromes.

Recent findings

Key molecular pathways underlying development of primary atopic diseases have recently been proposed. We test this classification through reviewing novel genes reported in the last 2 years and compare insights from pathway-analysis of genome-wide association studies (GWAS) of atopic-related traits.

Growing access to next-generation sequencing (NGS) has resulted in a surge in gene discovery, highlighting the utility and some pitfalls of this approach in clinical practice. The variability of presenting phenotypes reveals important gene-dosage effects. This has important implications for therapeutic strategies such as protein stabilization and modulators of JAK-STAT or TH2-cytokine signalling. We also consider the therapeutic implications raised by CARD11 deficiency, and wider applications of NGS including polygenic risk score in atopy.

Disorders presenting at the interface between PID and allergy are often difficult to diagnose, with serious consequences if missed. Application of NGS has already provided critical insights to pathways enabling targeted therapeutic interventions, and potential wider translation to polygenic disorders.
A Prognostic Index to Identify the Risk of Developing Depression Symptoms Among U.S. Medical Students Derived From a National, Four-Year Longitudinal Study
Authors: Dyrbye Liselotte N. , Wittlin Natalie M. , Hardeman Rachel R. , Yeazel Mark , Herrin Jeph , Dovidio John F. , Burke Sara E. , Cunningham Brooke , Phelan Sean M. , Shanafelt Tait D. , van Ryn Michelle
Published: September 2018

Purpose

To determine baseline individual and school-related factors associated with increased risk of developing depression symptoms by year four (Y4) of medical school, and to develop a prognostic index that stratifies risk of developing depression symptoms (Depression-PI) among medical students.

Method

The authors analyzed data from 3,743 students (79% of 4,732) attending 49 U.S. medical schools who completed baseline (2010) and Y4 (2014) surveys. Surveys included validated scales measuring depression, stress, coping, and social support. The authors collected demographics and school characteristics and conducted multivariate analysis to identify baseline factors independently associated with Y4 depression symptoms. They used these factors to create a prognostic index for developing depression. They randomly divided the data into discovery (n = 2,455) and replication (n = 1,288) datasets and calculated c statistics (c).

Results

The authors identified eight independent prognostic factors for experiencing depression symptoms during training within the discovery dataset: age; race; ethnicity; tuition; and baseline depression symptoms, stress, coping behaviors, and social support. The Depression-PI stratified four risk groups. Compared with the low risk group, those in the intermediate, high, and very high risk groups had an odds ratio of developing depression of, respectively, 1.75, 3.98, and 9.19 (c = 0.71). The replication dataset confirmed the risk groups.

Conclusions

Demographics; tuition; and baseline depression symptoms, stress, coping behaviors, and social support are independently associated with risk of developing depression during training among U.S. medical students. By stratifying students into four risk groups, the Depression-PI may allow for a tiered primary prevention approach.
Developing Professionalism and Professional Identity Through Unproctored, Flexible Testing
Authors: Ross Paula T. , Keeley Meg G. , Mangrulkar Rajesh S. , Karani Reena , Gliatto Peter , Santen Sally A.
Published: September 2018

The medical education community has devoted a great deal of attention to the development of professionalism in trainees within the context of clinical training—particularly regarding trainees’ handling of ethical dilemmas related to clinical care. The community, however, knows comparatively less about the development of professional behavior in medical students during the preclerkship years. In medical schools with flexible testing, students take quizzes or examinations in an unproctored setting at a time of their choosing—as long as it falls within a specified window of time. Unproctored, flexible testing offers students early opportunities to develop appropriate professional behavior. In this Perspective, the authors outline different flexible testing models from three institutions—University of Virginia School of Medicine, University of Michigan Medical School, and Icahn School of Medicine at Mount Sinai—all of which offer various levels of testing flexibility in relation to time and location. The authors’ experiences with these models suggest that preclinical medical students’ early development of professional behavior requires scaffolding by faculty and staff. Scaffolding involves setting clear, specific expectations for students (often through the form of an honor code), as well as active engagement and discussion with learners about the expectations and procedures for self-regulation in the academic environment.
Meta-analysis indicates that add-on devices and new endoscopes reduce colonoscopy adenoma miss rate
Authors: Gkolfakis Paraskevas , Tziatzios Georgios , Facciorusso Antonio , Muscatiello Nicola , Triantafyllou Konstantinos
Published: September 2018

Introduction

A variety of add-on devices and new-generation endoscopes have the potential to detect lesions ‘hidden’ behind colonic folds. We measured the effect of these new modalities on colonoscopy’s lesions miss rates by a meta-analysis of data from individual studies.

Materials and methods

We performed literature searches in Medline and Cochrane Library for back-to-back randomized-controlled trials evaluating colonoscope add-on devices and new endoscopes in terms of lesions miss rates. The effect size on study outcomes is shown as relative risk (95% confidence interval).

Results

We identified nine tandem studies with 1594 patients: seven evaluating add-on devices (one with cap, two with Endocuff, one with Endorings, one with Third-Eye Retroscope, two with G-EYE endoscope) and two evaluating the full-spectrum endoscopy system (FUSE) in comparison with conventional colonoscopy (CC). Overall, adenoma miss rate (AMR) was significantly lower with add-on devices/FUSE [0.33 (0.22–0.50), P<0.00001] compared with CC, the effect being similar among the add-on devices [0.35 (0.22–0.57), P<0.0001] and the FUSE [0.26 (0.15–0.46), P<0.00001] studies, respectively. Advanced AMR and polyp miss rate (PMR) were also significantly lower using add-on devices/FUSE [0.30 (0.21–0.44), P<0.0001 and 0.31 (0.13–0.79), P=0.01, respectively]. Use of add-on devices/FUSE scope was associated with significantly lower AMR and PMR in the proximal colon and it was associated with shortening of the colonoscopy surveillance interval.

Conclusion

Our meta-analysis provides evidence that AMR, advanced AMR, and PMR are significantly lower using add-on to colonoscope devices and the full-spectrum endoscopy systems compared with CC. Heterogeneity among the included studies and the small number of detected advanced adenomas call for cautious interpretation of the results.
Evaluation of a Magnetic Tracking and Electrocardiogram-based Tip Confirmation System for Peripherally Inserted Central Catheters in Pediatric Patients
Authors: Rosche Nina , Stehr Wolfgang
Published: September 2018

The purpose of this study was to investigate whether a magnetic tracking and electrocardiogram-based tip confirmation system (TCS) (Sherlock 3CG Tip Confirmation System; Bard, Covington, GA) permits safe and correct placement of a peripherally inserted central catheter (PICC) in the pediatric population. A total of 144 PICCs were placed using the TCS. After excluding participants for various reasons, 112/121 (92.56%) of PICCs were appropriately placed using the TCS. The TCS confirmed tip location an average of 7 to 18 minutes faster than radiographic imaging. There were no complications associated with the insertion of the PICCs using the TCS.
Losing Health Symbols Because of Nutrition-Related Problems in Advanced Cancer
Authors: Opsomer Sophie , Joossens Sofie , De Wit Claudia , Lauwerier Emelien , Pype Peter
Published: September 2018

Cancer and nutrition-related problems are extremely distressing events and disturb functioning and daily life. It is recognized that the effects of stressors challenging well-being are mediated by the meaning attached to these stressors. As nutrition-related problems are often being experienced within couples, it is also important to gain understanding of a partner’s interpretation of complaints and whether it coincides with that of the patient.

To explore the meaning attached to nutrition-related problems, a qualitative approach was followed. Seven couples, each composed of a patient with cancer and his/her cohabiting life partner, participated. Data were collected through in-depth interviews and analyzed by an interpretative phenomenological approach.

Nutrition-related problems among patients with advanced cancer are mostly perceived as destroying health and leading to loss of physical, psychological, and social health symbols. Because the meaning patients and their partners attach to nutrition-related problems is individual and dynamic, it is necessary to devote special attention to the issues on different occasions.

The study findings can assist nurses and other professional caregivers in providing psychological support for couples confronted with nutrition-related problems in advanced cancer. It is important to take into account the meaning patients and partners attach to these nutrition-related problems.
A Cost Analysis of Carpal Tunnel Release Surgery Performed Wide Awake versus under Sedation
Authors: Alter Todd H. , Warrender William J. , Liss Frederic E. , Ilyas Asif M.
Published: September 2018

Background:

Hand surgery under local anesthesia only has been used more frequently in recent years. The purpose of this study was to compare perioperative time and cost for carpal tunnel release performed under local anesthesia (“wide-awake local anesthesia no tourniquet,” or WALANT) only to carpal tunnel release performed under intravenous sedation.

Methods:

A retrospective comparison of intraoperative (operating room) surgical time and postoperative (postanesthesia care unit) time for consecutive carpal tunnel release procedures performed under both intravenous sedation and wide-awake local anesthesia was undertaken. All operations were performed by the same surgeon using the same mini-open surgical technique. A cost analysis was performed by means of standardized anesthesia billing based on base units, time, and conversion rates.

Results:

There were no significant differences between the two groups in terms of total operative time, 28 minutes in the intravenous sedation group versus 26 minutes in the wide-awake local anesthesia group. Postanesthesia care unit times were significantly longer in the intravenous sedation group (84 minutes) compared to the wide-awake local anesthesia group (7 minutes). Depending on conversion rates used, a total of $139 to $432 was saved in each case performed with wide-awake local anesthesia by not using anesthesia services. In addition, a range of $1320 to $1613 was saved for the full episode of care, including anesthesia costs, operating room time, and postanesthesia care unit time for each patient undergoing wide-awake local anesthesia carpal tunnel release.

Conclusion:

Carpal tunnel release surgery performed with the wide-awake local anesthesia technique offers significant reduction in cost for use of anesthesia and postanesthesia care unit resources.