bluuebunny/crossref_metadata_2025 huggingface dataset:
pH-Responsive self-assembly of cationic surfactants with a star-shaped tetra-carboxylate acid and the solubilization of hydrophobic drugs
Authors: Qi Ruilian , Liu Zhang , Zhou Chengcheng , Han Yuchun , Wang Yilin
Published: October 2017

Construction of a high-efficiency, pH-responsive self-assembly system from star-shaped tetra-carboxylate acid with cationic surfactants, and its solubilization of different hydrophobic drugs.
Enhancing Ear and Hearing Health Access for Children With Technology and Connectivity
Authors: Swanepoel De Wet
Published: October 2017

Purpose

Technology and connectivity advances are demonstrating increasing potential to improve access of service delivery to persons with hearing loss. This article demonstrates use cases from community-based hearing screening and automated diagnosis of ear disease.

Method

This brief report reviews recent evidence for school- and home-based hearing testing in underserved communities using smartphone technologies paired with calibrated headphones. Another area of potential impact facilitated by technology and connectivity is the use of feature extraction algorithms to facilitate automated diagnosis of most common ear conditions from video-otoscopic images.

Results

Smartphone hearing screening using calibrated headphones demonstrated equivalent sensitivity and specificity for school-based hearing screening. Automating test sequences with a forced-choice response paradigm allowed persons with minimal training to offer screening in underserved communities. The automated image analysis and diagnosis system for ear disease demonstrated an overall accuracy of 80.6%, which is up to par and exceeds accuracy rates previously reported for general practitioners and pediatricians.

Conclusion

The emergence of these tools that capitalize on technology and connectivity advances enables affordable and accessible models of service delivery for community-based ear and hearing care.
Decomposition of symmetric matrix–vector product over GF(2m)
Authors: Pan Jeng‐Shyang , Yang Chun‐Sheng , Lee Chiou‐Yng
Published: October 2017

Toeplitz matrix–vector product (TMVP) decomposition is an important approach for designing and implementing subquadratic multiplier. In this Letter, a symmetric matrix (SM), which is the sum of a symmetric TM and Hankel matrix, is proposed. Applying the symmetry property, 2‐way, 3‐way and n‐way splitting methods of SMVP is presented. On the basis of 2‐way splitting method, the recursive formula of SMVP is presented. Using the two cases n = 4 and 8, the SMVP decomposition approach has less space complexity than 2‐way TMVP, TMVP block recombination and symmetric TMVP for even‐type Gaussian normal basis multiplication.
PV inverter reactive power control for chance‐constrained distribution system performance optimisation
Authors: Ibrahim Sarmad , Cramer Aaron , Liu Xiao , Liao Yuan
Published: October 2017

Distributed generation has many potential benefits including use of renewable resources, increased customer participation, and decreased losses. However, as the penetration of distributed renewable energy sources increases, the technical challenges of integrating these resources into the power system increase as well. One such challenge is the rapid variation of voltages along distribution feeders in response to photovoltaic (PV) output fluctuations, and the reactive power capability of PV inverters can be used to address this challenge. A method of achieving optimal expected performance with respect to a figure of merit of interest to the distribution system operator while maintaining appropriate system voltage magnitudes and considering the uncertainty of PV power injections is proposed. The method utilises reactive power injection both to improve system performance and to compensate for variations in active power injection. It requires infrequent communication between the distribution system operator and the PV inverters and bases its decisions on short‐term forecasts, formulating voltage magnitude requirements as chance constraints. The proposed method is validated using the IEEE 123‐node radial distribution test feeder and shown to improve the distribution system performance (with respect to existing methods) and maintain suitable voltages.
Impact of the road network configuration on map‐matching algorithms for FCD in urban environments
Authors: Arregui Harbil , Loyo Estibaliz , Otaegui Oihana , Arbelaitz Olatz
Published: October 2017

Novel ubiquitous traffic sensors such as floating car data (FCD) are getting extended due to the use of 24 h connected smartphones and global positioning systems. Road conditions such as travel speeds in each road link and mobility demand can be monitored by measurements coming from moving vehicles consisting of geolocation and speed information with timestamps. Map‐matching is the process needed to identify the corresponding road link on a digital map and define the position of the geolocated vehicle on this link, overcoming positioning errors. Matching processes in urban environments are more prone to error due to the topology and features of city road networks. In this study, the accuracy of the map‐matching is discussed depending on the road configuration for FCD in urban and interurban scenarios, under sampling frequencies ranging from 5 to 60 s. Concretely, in this analysis, three matching techniques have been evaluated against road density, nominative speed limit, edge length and edge count values in order to quantify the impact of these variables on the matching accuracy.
Solar powered sensorless induction motor drive with improved efficiency for water pumping
Authors: Shukla Saurabh , Singh Bhim
Published: October 2017

This study deals with a speed sensorless induction motor drive (IMD) with efficiency optimisation. This drive is driven by a solar photovoltaic array for water pumping. The elimination of speed sensor increases the robustness and decreases cost of the IMD. The speed estimation is achieved by rotor flux‐oriented control in stationary reference frame. Moreover, the parameters, namely stator resistance adaptation, make the system parameters insensitive. The efficiency of the drive system is enhanced by optimising the excitation current by using a particle swarm optimisation technique. The smooth operation of overall system during starting and steady‐state condition is simulated in MATLAB/Simulink environment and validated on a prototype developed in the laboratory. The efficiency of the system with loss minimisation technique is compared with the conventional IMD. Simulated results comply with the test results and a comprehensive comparison is made to validate the suitability of proposed system.
Set value‐based dynamic model development for non‐linear manoeuvring target tracking problem in the presence of unknown but bounded disturbances
Authors: Alirezapouri Mohammad Ali , Khaloozadeh Hamid , Vali Ahmadreza , Arvan Mohammad Reza
Published: October 2017

The stochastic models developed for the manoeuvring target tracking (MTT) problem do not exhibit good performance owing to the lack of sufficient information about uncertainties. Moreover, each of the MTT models can be used for limited target manoeuvres. An ‘unknown but bounded’ (UBB)‐based non‐linear dynamic model for modelling time‐dependent acceleration and model uncertainties is proposed for addressing the aforementioned problems. In the UBB approach, uncertainties and target manoeuvre are modelled using information about their upper bounds only. The extended set membership filter can be used to estimate the target states and manoeuvre with this new dynamic model. In order to examine the stability of the proposed method, the input to state stability of the estimation error is analysed. Very good performance is achieved by the proposed dynamic model without precise information about the model uncertainties. The proposed MTT algorithm can be used to track both non‐manoeuvring and manoeuvring targets. The theoretical development is verified using simulations and the results are compared with those of other MTT methods. These comparisons demonstrate that the performance of the proposed method is better.
The XXL Survey
Authors: Guglielmo V. , Poggianti B. M. , Vulcani B. , Adami C. , Gastaldello F. , Ettori S. , Fotoupoulou S. , Koulouridis E. , Ramos Ceja M. E. , Giles P. , McGee S. , Altieri B. , Baldry I. , Birkinshaw M. , Bolzonella M. , Bongiorno A. , Brown M. , Chiappetti L. , Driver S. , Elyiv A. , Evrard A. , Garilli B. , Grootes M. , Guennou L. , Hopkins A. , Horellou C. , Iovino A. , Lidman C. , Liske J. , Maurogordato S. , Owers M. , Pacaud F. , Paltani S. , Pierre M. , Plionis M. , Ponman T. , Robotham A. , Sadibekova T. , Scodeggio M. , Sereno M. , Smolčić V. , Tuffs R. , Valtchanov I. , Vignali C. , Willis J.
Published: October 2017

Context. The fraction of galaxies bound in groups in the nearby Universe is high (50% at z ~ 0). Systematic studies of galaxy properties in groups are important in order to improve our understanding of the evolution of galaxies and of the physical phenomena occurring within this environment.

Aims. We have built a complete spectrophotometric sample of galaxies within X-ray detected, optically spectroscopically confirmed groups and clusters (G&C), covering a wide range of halo masses at z ≤ 0.6.

Methods. In the context of the XXL survey, we analyse a sample of 164 G&C in the XXL-North region (XXL-N), at z ≤ 0.6, with a wide range of virial masses (1.24 × 1013 ≤ M500,scal(M⊙) ≤ 6.63 × 1014) and X-ray luminosities ((2.27 × 1041 ≤ L500,scalXXL(erg s−1) ≤ 2.15 × 1044)). The G&C are X-ray selected and spectroscopically confirmed. We describe the membership assignment and the spectroscopic completeness analysis, and compute stellar masses. As a first scientific exploitation of the sample, we study the dependence of the galaxy stellar mass function (GSMF) on global environment.

Results. We present a spectrophotometric characterisation of the G&C and their galaxies. The final sample contains 132 G&C, 22 111 field galaxies and 2225 G&C galaxies with r-band magnitude <20. Of the G&C, 95% have at least three spectroscopic members, and 70% at least ten. The shape of the GSMF seems not to depend on environment (field versus G&C) or X-ray luminosity (used as a proxy for the virial mass of the system). These results are confirmed by the study of the correlation between mean stellar mass of G&C members and L500,scalXXL. We release the spectrophotometric catalogue of galaxies with all the quantities computed in this work.

Conclusions. As a first homogeneous census of galaxies within X-ray spectroscopically confirmed G&C at these redshifts, this sample will allow environmental studies of the evolution of galaxy properties.
“Drowning Brain in a Pool of CSF” — A Rare Complication of Periencephalic Subdural Panhygroma following Removal of a Posterior Fossa Tumor
Authors: Behera Bikash , Deo Ram , Mishra Sanjib , Biswal Jyotirmayee , Das Deepak
Published: October 2017

Posterior fossa tumors are commonly encountered in pediatric age group patients. Most of these tumors present with features of hydrocephalus in the child. Conventionally, these cases are managed by suboccipital craniotomy with decompression of the tumor mass to establish the free flow of cerebrospinal fluid (CSF) across fourth ventricle and aqueduct of Sylvius. Following resection of posterior fossa tumor, appearance of subdural hygroma is a rare phenomenon.

Though few cases of subdural hygroma are reported in literature following foramen magnum decompression in Chiari's malformation, their appearance following posterior fossa tumor resection is alien to medical literature and limited to only two case reports. Here the authors present a patient with periencephalic subdural panhygroma (PSP) following posterior fossa tumor resection who was successfully treated with a ventriculoperitoneal shunt (VPS) to accomplish a symptomatic and radiologic remission.
Leaps in Technology: Advanced MR Imaging after Total Hip Arthroplasty
Authors: Khodarahmi Iman , Nittka Mathias , Fritz Jan
Published: October 2017

The vast majority of the metal-related artifacts in magnetic resonance imaging (MRI) arise from B0 inhomogeneity. These artifacts include failed fat suppression, signal loss, signal pileup, and image distortions. Metal artifact reduction sequence MRI has been used to mitigate these artifacts via optimization of the scan parameters and exploiting new techniques such as fully phase-encoded imaging and multispectral imaging including multi-acquisition variable-resonance image combination and slice encoding for metal artifact correction. Applicability of MRI in the vicinity of metal implants has been revolutionized by these new techniques at the expense of longer acquisition times. To reach clinically viable scan times, these novel techniques have been successfully coupled with various acceleration paradigms such as parallel imaging and compressed sensing.
Inflammatory Conditions of the Hip
Authors: Teh James , Schueller-Weidekamm Claudia
Published: October 2017

Most cases of adult hip pain are related to osteoarthritis, so inflammatory causes are often not considered. This review article describes the different entities of hip inflammation and provides an approach on how to differentiate rheumatologic disorders from degenerative changes, synovial tumors, and infection. Indications for imaging, the correct choice of imaging modality, and scanning protocols are also discussed. The differential diagnosis of inflammatory lesions of the hips is addressed in the context of image interpretation.
Bilateral Traumatic Thalamic Hemorrhage: A Rare Clinical Presentation
Authors: Mandour Cherkaoui , Gazzaz Miloudi , Mostarchid Brahim
Published: October 2017

Bilateral traumatic thalamic hemorrhage is a very rare occurrence, especially after head trauma, and is limited to case reports. The authors present a 27-year-old man, admitted for head trauma causing bilateral thalamic bleeding. Posttraumatic intracerebral bleeding is caused by focal or diffuse axonal injury. Bilateral traumatic thalamic hemorrhage is a rare clinical and radiologic presentation.
Multifokale Elektroretinografie bei Patienten mit Poppers-Makulopathie
Authors: Pahlitzsch Milena , Salchow Daniel , Rossel Mirjam , Bergholz Richard
Published: October 2017

Hintergrund Die Makulopathie ist eine potenzielle Nebenwirkung der inhalativen Amylnitrit- bzw. Poppers-Einnahme. Sie ist gekennzeichnet durch einen plötzlichen, schmerzlosen und i. d. R. bilateralen Visusverlust. Während die funduskopischen Veränderungen dezent sind, zeigen sich im OCT typische Alterationen der subfovealen, äußeren Netzhautschichten. Das genaue Ausmaß der retinalen Funktionsbeeinträchtigung ist bislang unzureichend charakterisiert.

Material/Methoden Wir verglichen die Antwortdichten und Gipfelzeiten von N1 und P1 im multifokalen Elektroretinogramm (mfERG) von 6 Patienten mit Poppers-Makulopathie (12 Augen, medianes Alter 46 Jahre) mit denen einer Kontrollgruppe bestehend aus 6 gesunden Probanden (12 Augen, medianes Alter 45,5 Jahre).

Ergebnisse Sowohl die Antwortdichten als auch die Gipfelzeiten von N1 und P1 waren bei den Patienten mit Poppers-Makulopathie niedriger. Dies galt vor allem für das Zentralpotenzial (Ring 1) und die peripheren Ringe 4 und 5. Ein statistisch signifikanter Unterschied ergab sich aber lediglich für ein Hexagon der N1-Antwortdichte (p = 0,039), nicht aber für die Summenantwort oder die gemittelten Exzentrizitäten (Ring 1 – 5, p > 0,05).

Schlussfolgerung Das multifokale Elektroretinogramm ist bei Patienten mit Poppers-Makulopathie nicht relevant beeinträchtigt, was im Kontrast zur deutlichen Auswirkung auf die Sehschärfe steht. Das multifokale Elektroretinogramm eignet sich im Gegensatz zum OCT nicht zur Diagnosestellung.
Einfluss der Makulareifung auf Ganzfeld- und multifokales ERG bei ehemaligen Extremfrühgeborenen mit und ohne akute Frühgeborenenretinopathie
Authors: Bowl Wadim , Schweinfurth Silke , Holve Kerstin , Stieger Knut , Lorenz Birgit , Andrassi-Darida Monika
Published: October 2017

Einleitung Die Entwicklung und Reifung der Netzhaut ist ein komplexer Prozess, der sich bis in das Kleinkindesalter und darüber hinaus erstrecken kann. Die zentrale Netzhaut frühgeborener Kinder kann durch eine Reifungsstörung betroffen sein, die durch eine abgeflachte, dickere Fovea mit überlagernden Schichten innerer Netzhaut und einem gestörten Verhältnis der äußeren Photorezeptorschicht zu den inneren Netzhautschichten („macular developmental arrest“: MDA) gekennzeichnet ist und zu funktionellen Nachteilen führen kann (Bowl et al. 2016 18). In dieser Studie untersuchten wir ehemalige Extremfrühgeborene mit spontan zurückgebildeter Frühgeborenenretinopathie (ROP) und ohne ROP sowie gleichaltrige Termingeborene elektrophysiologisch und betrachteten die Ergebnisse in Bezug zur Makulareifung.

Methoden Im Rahmen einer umfangreichen prospektiven Kohortenstudie untersuchten wir n = 60 frühgeborene Kinder mit spontan rückgebildeter ROP (srROP, n = 15), ohne ROP (noROP, n = 45) in der Anamnese sowie n = 10 termingeborene altersentsprechende Kinder (Term). Bei jedem Kind wurden zur funktionellen Analyse jeweils ein Ganzfeldelektroretinogramm (ffERG: a- und b-Welle), multifokales ERG (mfERG: P1) nach ISCEV-Standard sowie eine optische Kohärenztomografie (SD-OCT, Spectralis, Heidelberg Engineering, Deutschland) der Fovea zur morphologischen Einordnung durchgeführt.

Ergebnisse Im skotopischen ffERG zeigten Kinder mit srROP und noROP vor allem dann signifikant reduzierte b-Wellen-Antworten, wenn ein MDA im OCT nachweisbar war. Im mfERG war die P1-Komponente des zentralen Hexagons und des 2. konzentrischen Ringes bei Kindern mit MDA signifikant reduziert. Alle anderen Parameter zeigten keinen signifikanten Unterschied zwischen den Gruppen.

Schlussfolgerung Elektrophysiologische Veränderungen finden sich bei ehemaligen extrem frühgeborenen Kindern vor allem bei im SD-OCT nachweisbarer Makulareifungsstörung (MDA), und zwar sowohl bei Kindern ohne akute ROP als auch bei Kindern mit spontan zurückgebildeter ROP: Die reduzierte b-Welle im skotopischen ffERG und die reduzierte P1-Komponente im mfERG deuten auf eine Beteiligung der Bipolarzellen bei MDA hin. Insbesondere die Korrelation von MDA mit Auffälligkeiten im ffERG könnte ein Zeichen dafür sein, dass MDA mit einer globaleren Reifungsstörung der Netzhaut einhergeht und diese bei Extremfrühgeborenen mit und ohne ROP auftreten kann.
Enhanced biexciton emission from single quantum dots encased in N-type semiconductor nanoparticles
Authors: Li Zhijie , Zhang Guofeng , Li Bin , Chen Ruiyun , Qin Chengbing , Gao Yan , Xiao Liantuan , Jia Suotang
Published: October 2017

By encasing single near-infrared emitting CdSeTe/ZnS3ML core/multishell quantum dots (QDs) in N-type semiconductor indium tin oxide (ITO) nanoparticles, an enhanced biexciton emission can be realized. The ITO nanoparticles with a high electron density can increase the dielectric screening of single QDs to reduce the Coulomb interactions between carriers, thus suppressing the nonradiative Auger recombination of biexcitons. It is observed that an average g(2)(0) = 0.57 in the second-order correlation function curves, which indicates the effective creation of biexciton and subsequent two-photon emission from single QDs encased in ITO nanoparticles. The fluorescence quantum yield ratio of the biexciton to single-exciton emission is increased to ∼4.8 times, while the Auger recombination rate reduces by almost an order of magnitude.
Resonant-convergent second-order nonlinear response functions at the levels of Hartree–Fock and Kohn–Sham density functional theory
Authors: Fahleson Tobias , Norman Patrick
Published: October 2017

The second-order nonlinear (or cubic) response function is derived from the Ehrenfest theorem with inclusion made of the finite lifetimes of the excited states, representing the extension of the derivation of the quadratic response function in the same framework [P. Norman et al., J. Chem. Phys. 123, 194103 (2005)]. The resulting damped response functions are physically sound and converging also in near-resonance and resonance regions of the spectrum. Being an accurate approximation for small complex frequencies (defined as the sum of an optical frequency and an imaginary damping parameter), the polynomial expansion of the complex cubic response function in terms of the said frequencies is presented and used to validate the program implementation. In terms of approximate state theory, the computationally tractable expressions of the damped cubic response function are derived and implemented at the levels of Hartree–Fock and Kohn–Sham density functional theory. Numerical examples are provided in terms of studies of the intensity-dependent refractive index of para-nitroaniline and the two-photon absorption cross section of neon. For the latter property, a numerical comparison is made against calculations of the square of two-photon matrix elements that are identified from a residue analysis of the resonance-divergent quadratic response function.
Aggregation of flexible polyelectrolytes: Phase diagram and dynamics
Authors: Tom Anvy Moly , Rajesh R. , Vemparala Satyavani
Published: October 2017

Similarly charged polymers in solution, known as polyelectrolytes, are known to form aggregated structures in the presence of oppositely charged counterions. Understanding the dependence of the equilibrium phases and the dynamics of the process of aggregation on parameters such as backbone flexibility and charge density of such polymers is crucial for insights into various biological processes which involve biological polyelectrolytes such as protein, DNA, etc. Here, we use large-scale coarse-grained molecular dynamics simulations to obtain the phase diagram of the aggregated structures of flexible charged polymers and characterize the morphology of the aggregates as well as the aggregation dynamics, in the presence of trivalent counterions. Three different phases are observed depending on the charge density: no aggregation, a finite bundle phase where multiple small aggregates coexist with a large aggregate and a fully phase separated phase. We show that the flexibility of the polymer backbone causes strong entanglement between charged polymers leading to additional time scales in the aggregation process. Such slowing down of the aggregation dynamics results in the exponent, characterizing the power law decay of the number of aggregates with time, to be dependent on the charge density of the polymers. These results are contrary to those obtained for rigid polyelectrolytes, emphasizing the role of backbone flexibility.
Possible spin gapless semiconductor type behaviour in CoFeMnSi epitaxial thin films
Authors: Kushwaha Varun K. , Rani Jyoti , Tulapurkar Ashwin , Tomy C. V.
Published: October 2017

Spin-gapless semiconductors with their unique band structure have recently attracted much attention due to their interesting transport properties that can be utilized in spintronics applications. We have deposited the thin films of a quaternary spin-gapless semiconductor CoFeMnSi Heusler alloy on MgO (001) substrates using a pulsed laser deposition system. These films show epitaxial growth along the (001) direction and display a uniform and smooth crystalline surface. The magnetic properties reveal that the film is ferromagnetically soft along the in-plane direction and its Curie temperature is well above 400 K. The electrical conductivity of the film is low and exhibits a nearly temperature independent semiconducting behaviour. The estimated temperature coefficient of resistivity for the film is –7 × 10–10 Ω m/K, which is comparable to the values reported for spin-gapless semiconductors.
Calibration-free extraction of constitutive parameters of magnetically coupled anisotropic metamaterials using waveguide measurements
Authors: Hasar U. C. , Buldu G. , Bute M. , Muratoglu A.
Published: October 2017

A calibration-free method for extraction of electromagnetic properties of magnetically coupled anisotropic biaxial metamaterial (MM) slabs from waveguide measurements is proposed. It relies on three measurement steps (thru, empty line, and the same line arbitrarily loaded by the MM slab) to extract electromagnetic properties. It is evaluated against another calibration-dependent method for retrieval of electromagnetic properties of a MM slab constructed by C-shaped resonators. From evaluation analysis, we note that our method, as compared to the calibration-dependent method, not only accurately extracts electromagnetic properties without requiring the use of expensive calibration standards but also is reference-invariant.
Accurate quantification of glass-forming ability by measuring effective volume relaxation of supercooled melt
Authors: Ryu C. W. , Kang D. H. , Jeon S. , Lee G. W. , Park E. S.
Published: October 2017

Herein, we elucidate how to accurately quantify glass-forming ability (GFA) by measuring effective volume relaxation of supercooled melt. We propose a new parameter, denoted as κ, for representing the relaxation, which is calculated by combining temperature-dependent changes of normalized specific volume reflecting relative volume relaxation with the normalized temperature range reflecting the relative position of the C curve in a Time-Temperature-Transformation (TTT) diagram. The interrelationship between the κ parameter and critical cooling rate is elaborated by measuring V-T diagrams and TTT diagrams of Zr55Co26Al19 and Zr46Cu30.14Al8Ag8.36Be7.5 glass-forming alloys and discussed in comparison with representative GFA parameters reported up to date. These results would give us a guideline on how to precisely evaluate GFA by linking volumetric aspect to thermodynamic and kinetic aspects for glass formation and help develop customized glass-forming alloys as well as a highly precise control of glass formation process.
Electrical compensation mechanism in fluorine-doped SnO2
Authors: Kang Youngho , Van de Walle Chris G.
Published: October 2017

We report first-principles results for the electrical compensation mechanism in fluorine-doped SnO2 (SnO2:F), a widely used transparent conductor. We show that interstitial fluorine, which has traditionally been invoked as the source of compensation, has a high formation energy and hence cannot be responsible for compensation. Instead, we attribute compensation to complexes involving two fluorine atoms sharing an oxygen site. Formation of these complexes can explain the puzzling reduction (rather than a simple saturation) in the carrier concentration observed at high F concentrations.
Peptide dimerization-dissociation rates from replica exchange molecular dynamics
Authors: Leahy Cathal T. , Kells Adam , Hummer Gerhard , Buchete Nicolae-Viorel , Rosta Edina
Published: October 2017

We show how accurate rates of formation and dissociation of peptide dimers can be calculated using direct transition counting (DTC) from replica-exchange molecular dynamics (REMD) simulations. First, continuous trajectories corresponding to system replicas evolving at different temperatures are used to assign conformational states. Second, we analyze the entire REMD data to calculate the corresponding rates at each temperature directly from the number of transition counts. Finally, we compare the kinetics extracted directly, using the DTC method, with indirect estimations based on trajectory likelihood maximization using short-time propagators and on decay rates of state autocorrelation functions. For systems with relatively low-dimensional intrinsic conformational dynamics, the DTC method is simple to implement and leads to accurate temperature-dependent rates. We apply the DTC rate-extraction method to all-atom REMD simulations of dimerization of amyloid-forming NNQQ tetrapetides in explicit water. In an assessment of the REMD sampling efficiency with respect to standard MD, we find a gain of more than a factor of two at the lowest temperature.
Internal force corrections with machine learning for quantum mechanics/molecular mechanics simulations
Authors: Wu Jingheng , Shen Lin , Yang Weitao
Published: October 2017

Ab initio quantum mechanics/molecular mechanics (QM/MM) molecular dynamics simulation is a useful tool to calculate thermodynamic properties such as potential of mean force for chemical reactions but intensely time consuming. In this paper, we developed a new method using the internal force correction for low-level semiempirical QM/MM molecular dynamics samplings with a predefined reaction coordinate. As a correction term, the internal force was predicted with a machine learning scheme, which provides a sophisticated force field, and added to the atomic forces on the reaction coordinate related atoms at each integration step. We applied this method to two reactions in aqueous solution and reproduced potentials of mean force at the ab initio QM/MM level. The saving in computational cost is about 2 orders of magnitude. The present work reveals great potentials for machine learning in QM/MM simulations to study complex chemical processes.
Seed viability of early maturing alpine ash (Eucalyptus delegatensis subsp. delegatensis) in the Australian Alps, south-eastern Australia, and its implications for management under changing fire regimes
Authors: Doherty Michael D. , Gill A. Malcolm , Cary Geoffrey J. , Austin Mike P.
Published: October 2017

Eucalyptus delegatensis R.T. Baker subsp. delegatensis is an interval-sensitive, fire-killed eucalypt that dominates large tracts of montane forest in the Australian Alps. Although it has been widely accepted in forest management that E. delegatensis takes 20 years to flower and fruit after stand-replacing fire events, recent observations after high intensity fires in the Australian Alps have shown that early flowering and fruiting is occurring from what can be termed ‘precocious’ individuals in some areas. In some instances, early flowering and fruit set is occurring within 6 years after stand-replacing fire. One historical study in the Australian Capital Territory had noted that such seed was viable, but we found no reported experiments documenting this or detailing the degree of viability. Here we discuss the results of a germination experiment undertaken on seed collected from Namadgi National Park from early-maturing alpine ash trees. Although at the low end of known viability estimates for E. delegatensis, seed from these individuals was nonetheless found to be viable, with a mean of 455 (s.d. = 139) germinants per 10 g of chaff and seed mix. We discuss this result in relation to fire management in the Australian Alps and suggest further research that needs to be undertaken to better document and understand the phenomenon.
Microstructure, mechanical properties and failure behaviour of protrusion friction stir spot welded 2024 aluminium alloy sheets
Authors: Dourandish S. , Mousavizade S. M. , Ezatpour H. R. , Ebrahimi G. R.
Published: October 2017

The current study investigates the mechanical and microstructure properties of 2024 aluminium alloy welded by protrusion friction stir spot welding as a novel method to produce keyhole-free welds. Tool rotation speed and anvil protrusion height are used as effective variables of the process to obtain optimum conditions. Results illustrate that the keyhole-free welds with the joint show superior mechanical properties in protrusion friction stir spot welding compared to conventional friction stir spot welding. Failure mode changes from interfacial mode to circumferential mode by increasing the nugget zone depth and joint length, while the effect of nugget zone is considerable. Finally, welding at a rotation speed of 1600 rev min−1 and a protrusion height of 0.4 mm presents significant mechanical properties with more joint length.
Acquisition of cell migration defines NK cell differentiation from hematopoietic stem cell precursors
Authors: Lee Barclay J. , Mace Emily M.
Published: October 2017

Human natural killer (NK) cells are generated from CD34+ precursors and can be differentiated in vitro by coculture with developmentally supportive stromal cells. We have previously described the acquisition of cell migration as a feature of NK cell terminal maturation in this system. Here we perform continuous long-term imaging and tracking of NK cell progenitors undergoing in vitro differentiation. We demonstrate that NK cell precursors can be tracked over long time periods on the order of weeks by utilizing phase-contrast microscopy and show that these cells acquire increasing motility as they mature. Additionally, we observe that NK cells display a more heterogeneous range of migratory behaviors at later stages of development, with the acquisition of complex modes of migration that are associated with terminal maturation. Together these data demonstrate previously unknown migratory behaviors of innate lymphocytes undergoing lineage differentiation revealed by long-term imaging and analysis workflows.
Weighted mining of massive collections of P-values by convex optimization
Authors: Dobriban Edgar
Published: October 2017

Researchers in data-rich disciplines—think of computational genomics and observational cosmology—often wish to mine large bodies of $P$-values looking for significant effects, while controlling the false discovery rate or family-wise error rate. Increasingly, researchers also wish to prioritize certain hypotheses, for example, those thought to have larger effect sizes, by upweighting, and to impose constraints on the underlying mining, such as monotonicity along a certain sequence. We introduce Princessp, a principled method for performing weighted multiple testing by constrained convex optimization. Our method elegantly allows one to prioritize certain hypotheses through upweighting and to discount others through downweighting, while constraining the underlying weights involved in the mining process. When the $P$-values derive from monotone likelihood ratio families such as the Gaussian means model, the new method allows exact solution of an important optimal weighting problem previously thought to be non-convex and computationally infeasible. Our method scales to massive data set sizes. We illustrate the applications of Princessp on a series of standard genomics data sets and offer comparisons with several previous ‘standard’ methods. Princessp offers both ease of operation and the ability to scale to extremely large problem sizes. The method is available as open-source software from github.com/dobriban/pvalue_weighting_matlab (accessed 11 October 2017).
Soliton Resolution for Corotational Wave Maps on a Wormhole
Authors: Rodriguez Casey
Published: October 2017

In this article, we initiate the study of finite energy equivariant wave maps from the $(1+3)$-dimensional spacetime ${\mathbb R} \times ({\mathbb R} \times {\mathbb S}^2) {\rightarrow} {\mathbb S}^3$ where the metric on ${\mathbb R} \times ({\mathbb R} \times {\mathbb S}^2)$ is given by \begin{align*} {\rm d}s^2 = -{\rm d}t^2 + {\rm d}r^2 + (r^2 + 1) \left ( {\rm d} \theta^2 + \sin^2 \theta {\rm d} \varphi^2 \right)\!, \quad t,r \in {\mathbb R}, (\theta,\varphi) \in {\mathbb S}^2. \end{align*} The constant time slices are each given by the Riemannian manifold ${\mathbb R} \times {\mathbb S}^2$ with metric \begin{align*} {\rm d}s^2 = {\rm d}r^2 + (r^2 + 1) \left ( {\rm d} \theta^2 + \sin^2 \theta{\rm d} \varphi^2 \right)\!. \end{align*} This Riemannian manifold contains two asymptotically Euclidean ends at $r \rightarrow \pm \infty$ that are connected by a spherical throat of area $4 \pi^2$ at $r = 0$. The spacetime ${\mathbb R} \times ({\mathbb R} \times {\mathbb S}^2) {\rightarrow} {\mathbb S}^3$ is a simple example of a wormhole geometry in general relativity. In this work, we will consider 1-equivariant or corotational wave maps. Each corotational wave map can be indexed by its topological degree $n$. For each $n$, there exists a unique energy minimizing corotational harmonic map $Q_{n} : {\mathbb R} \times {\mathbb S}^2 \rightarrow {\mathbb S}^3$ of degree $n$. In this work, we show that modulo a free radiation term, every corotational wave map of degree $n$ converges strongly to $Q_{n}$. This resolves a conjecture made by Bizon and Kahl for the corotational case.
The Perils of Vanguardism
Authors: Gordon Joshua C
Published: October 2017

Over the past 25 years, Sweden has gone from having one of the most generous unemployment benefit systems among the rich democracies to one of the least. This article advances a multi-causal explanation for this unexpected outcome. It shows how the benefit system became a target of successive right-wing governments due to its role in fostering social democratic hegemony. Employer groups, radicalized by the turbulent 1970s more profoundly than elsewhere, sought to undermine the system, and their abandonment of corporatism in the early 1990s limited unions’ capacity to restrain right-wing governments in retrenchment initiatives. Two further developments help to explain the surprising political resilience of the cuts: the emergence of a private (supplementary) insurance regime and a realignment of working-class voters from the Social Democrats to parties of the right, especially the nativist Sweden Democrats, in the context of a liberal refugee/asylum policy.
Detection, Identification, and Molecular Characterization of the 16SrII-D Phytoplasmas Infecting Vegetable and Field Crops in Oman
Authors: Al-Subhi Ali M. , Hogenhout Saskia A. , Al-Yahyai Rashid A. , Al-Sadi Abdullah M.
Published: October 2017

Typical symptoms of phytoplasma infection were observed on 11 important crops in Oman that included alfalfa, sesame, chickpea, eggplant, tomato, spinach, rocket, carrot, squash, field pea, and faba bean. To identify the phytoplasmas in these crops, samples from infected and asymptomatic plants were collected, followed by amplifying and sequencing of the 16S ribosomal RNA, secA, tuf, imp, and SAP11 genes. We found that these sequences share >99% similarity with the peanut witches’ broom subgroup (16SrII-D). Whereas some sequence variation was found in the five genes among 11 phytoplasma isolates of different crops, all sequences grouped into one clade along with those of other phytoplasmas belonging to the 16SrII-D group. Thus, 16SrII-D phytoplasmas infect a diverse range of crops in Oman. Phytoplasmas in this group have not been reported to occur in carrot, spinach, rocket, and field pea previously. Within Oman, this is the first report of the presence of 16SrII-D phytoplasmas in tomato, spinach, rocket, carrot, squash, field pea, and faba bean. Sequences of the five genes enabled for better distinction of the 16SrII-D phytoplasmas that occur in Oman.
Integrating Training in Quality Improvement and Health Equity in Graduate Medical Education: Two Curricula for the Price of One
Authors: Aysola Jaya , Myers Jennifer S.
Published: October 2017

A recent call to address health care disparities has come from the Accreditation Council for Graduate Medical Education’s (ACGME’s) Clinical Learning Environment Review (CLER) program. The CLER program aspires that faculty and residents will identify the disparities among the patient populations they serve and engage in quality improvement (QI) activities designed to address them. In this Perspective, the authors provide a framework for integrating QI and health equity principles in graduate medical education to meet these ACGME expectations. The authors illustrate their four-step framework by describing a faculty development workshop that provides strategies and tools for embedding equity into existing QI educational efforts and using QI methods to address equity challenges. Using examples, the authors outline how medical educators can begin to integrate QI and equity initiatives to address health care disparities and involve their residents/fellows in the process. In addition, the authors emphasize the importance of applying an equity lens to QI interventions and of recognizing that QI initiatives will have different impacts on outcomes depending on the patient population. The authors conclude by discussing the need for institutional leadership to build capacity and training to improve data collection and reporting of quality metrics by demographic variables; provide resources to disseminate lessons learned; support faculty development to teach and mentor trainees through equity-related QI work; and prioritize time in the curriculum for learners to participate in equity improvement activities.
Relationship Between PD-L1 Expression and CD8+ T-cell Immune Responses in Hepatocellular Carcinoma
Authors: Huang Chun-yu , Wang Ying , Luo Guang-yu , Han Feng , Li Yong-qiang , Zhou Zhong-guo , Xu Guo-liang
Published: October 2017

As PD-1/PD-L1 immune checkpoint inhibitors exhibited promising clinical outcomes in various types of solid tumors, PD-1/PD-L1 blockades have been explored for the treatment of hepatocellular carcinoma (HCC). However, the association of PD-L1 with antitumor immunoregulation is not clearly defined in HCC. Here, we evaluated the characteristics of PD-L1 expression, CD8+ T-cell infiltration and their relationship in HCC. A total of 411 resected tumor specimens from HCC patients were immunostained for PD-L1 and CD8. Only 78 (19%) cases showed ≥5% membranous PD-L1 expression on tumor cells, although a significantly positive correlation was found between PD-L1 expression and CD8+ T-cell densities. Moreover, patients with higher tumor PD-L1 expression also showed a higher hepatitis B virus load, which was also related to increased CD8 infiltration. Survival analysis suggested that both tumor and stroma PD-L1 status did not significantly affect overall survival or recurrence-free survival in patients. Although high CD8+ T-cell density was overall associated with better overall survival and recurrence-free survival, its favorable prognostic value was eliminated by high tumor PD-L1 expression. Further flow cytometric and enzyme-linked immunosorbent assay (ELISA) results from the coculture of HCC cell lines with specific CD8+ cytotoxic T lymphocytes (CTLs) demonstrated that CD8+ CTLs remarkably upregulated PD-L1 expression on tumor cell lines by HLA class-I specificity, and the overexpression of tumor PD-L1 impaired interferon-γ secretion by CD8+ CTLs in a negative feedback regulation mechanism. In conclusion, our findings reveal an interaction between PD-L1 expression and CD8+ T-cell immunity in HCC, although PD-L1 is not a prognostic factor for the patients.
Safe Administration of An Anti-PD-1 Antibody to Kidney-transplant Patients: 2 Clinical Cases and Review of the Literature
Authors: Winkler Julia K. , Gutzmer Ralf , Bender Carolin , Lang Nina , Zeier Martin , Enk Alexander H. , Hassel Jessica C.
Published: October 2017

Antiprogrammed cell-death protein 1 (PD-1) antibodies have revolutionized therapy of metastatic melanoma and other tumors, but some subgroups of patients such as immunosuppressed patients after solid-organ transplantation, have regularly been excluded from clinical studies. We report 2 cases of kidney-transplant patients who received an anti-PD-1 antibody to treat metastatic melanoma. Treatment was tolerated well with no relevant adverse events and stable kidney functions, but the melanoma progressed in both patients. Factors potentially affecting risk of allograft rejection and response to treatment, for example, immunosuppressive regimen and therapeutic sequence, are discussed on the basis of current literature. Further studies are necessary to determine the risk of allograft rejection and the therapeutic benefit of anti-PD-1 antibodies for organ-transplanted patients, in particular as these checkpoint inhibitors have become therapeutic standard in a variety of tumors other than melanoma.
Prediction of Descemet Membrane Perforation During Deep Anterior Lamellar Keratoplasty in Patients With Keratoconus With Stromal Scar
Authors: Ozmen Mehmet Cuneyt , Yesilirmak Nilufer , Aydin Bahri , Ceylanoglu Kubra Serbest , Atalay Hatice Tuba , Akata Fikret
Published: October 2017

Objectives:

To report big-bubble deep anterior lamellar keratoplasty (DALK) in patients with keratoconus with corneal stromal scar, and to investigate factors that can influence intraoperative Descemet membrane (DM) perforation.

Methods:

A retrospective study included patients with keratoconus with central stromal scar that underwent DALK using the big-bubble technique. Best spectacle–corrected visual acuity (BSCVA), keratometry, minimum corneal thickness (MCT), stromal scar depth, and endothelial cell density (ECD) were recorded. Receiver operating characteristic (ROC) curves were analyzed to predict an intraoperative perforation related to stromal scar.

Results:

Thirty-eight eyes of 38 patients with keratoconus (mean age: 30.0±9.2 years) were included in this study. Thirty-four eyes had successful DALK; in four eyes, the procedure was converted to penetrating keratoplasty because of DM macroperforations. Successful big-bubble formation was achieved in 24 of 38 (63.2%) eyes, whereas in 10 eyes, manual dissection was used to complete the DALK. Mean preoperative and postoperative second year BSCVA were 1.3 (±0.4) and 0.5 (±0.2) logarithm of the minimum angle of resolution (P<0.001), keratometry values were 65.5±7.4 and 42.8±7.8 diopters (P<0.001), and ECD were 2,740±359 and 2,279±452 cells/mm2 (P<0.001), respectively. Using ROC analysis, the area under curve value to predict DM perforation was found to be 0.792 (scar/MCT ratio, P=0.04) and the best cutoff point for scar depth/MCT ratio was 53%.

Conclusion:

Big-bubble DALK is effective in patients with keratoconus with stromal scars. Scar depth/MCT ratio seems to predict the DM perforation.
Can Economic Model Transparency Improve Provider Interpretation of Cost-effectiveness Analysis? Evaluating Tradeoffs Presented by the Second Panel on Cost-effectiveness in Health and Medicine
Authors: Padula William V. , McQueen Robert Brett , Pronovost Peter J.
Published: October 2017

The Second Panel on Cost-Effectiveness in Health and Medicine convened on December 7, 2016 at the National Academy of Medicine to disseminate their recommendations for conduct, methodological practices, and reporting of cost-effectiveness analyses (CEAs). Following its summary, panel proceedings included lengthy discussions including the field’s struggle to disseminate findings efficiently through peer-reviewed literature to target audiences. With editors of several medical and outcomes research journals in attendance, there was consensus that findings of cost-effectiveness analyses do not effectively reach other researchers or health care providers. The audience members suggested several solutions including providing additional training to clinicians in cost-effectiveness research and requiring that cost-effectiveness models are made publicly available. However, there remains the questions of whether making economic modelers’ work open-access through journals is fair under the defense that these models remain one’s own intellectual property, or whether journals can properly manage the peer-review process specifically for cost-effectiveness analyses. In this article, we elaborate on these issues and provide some suggested solutions that may increase the dissemination and application of cost-effectiveness literature to reach its intended audiences and ultimately benefit the patient. Ultimately, it is our combined view as economic modelers and clinicians that cost-effectiveness results need to reach the clinician to improve the efficiency of medical practice, but that open-access models do not improve clinician access or interpretation of the economics of medicine.