bluuebunny/crossref_metadata_2025 huggingface dataset:
Engineering application architecture study on an LCC parallel MTDC transmission system
Authors: Xinyang Liu , Weiyang Yin , Hongjie Jia , Ling Wang
Published: January 2019

Multi‐terminal DC (MTDC) transmission system is one of the effective technical means to perform a wide range connection of energy and load centres, also it has strong competitiveness and is economic efficiency. This study proposes full‐scale studies on engineering application architecture of an MTDC system. Firstly, advantages and weaknesses of several typical types of MTDC are analysed, and based on the LCC parallel MTDC (P‐MTDC) system, which is most applicable among all types, detailed studies are done on main topology, including polarity‐reversal switches to realise power reversion; secondly, P‐MTDC main circuit calculation method is presented, which decoupled the main circuit calculation into two parts: DC network and converter equation calculation, and general admittance matrix of the DC network is deduced in the study; thirdly, a novel constant‐U control strategy is proposed to simplify the control logic and reduce the control system complexity, by means of setting the nearest point of common coupling from the rectifier station as the voltage control reference point. Finally, one practical case study is taken, for example, of a certain three‐terminal DC project in the world, rated DC parameters are calculated, and a simulation model of MTDC system is built on Electro Magnetic Transient in DC System (EMTDC). The validity of the polarity‐reversal control strategy proposed in the study is demonstrated by simulation.
Hyparktikón et substantivum : entre verbe et nom dans la grammaire grecque et latine
Authors: Callipo Manuela
Published: January 2019

Apollonius Dyscole range parmi les hyparktikà rhḗmata les verbes aussi bien copulatifs que d’appellation : son usage reste un unicum dans l’ensemble du corpus grammatical grec tel qu’il nous a été transmis. Le système apollonien peut être expliqué – nous semble-t-il – par sa conception du nom, censé signifier à la fois la substance et la qualité du référent et donc lié à la signification de l’hyparxis / ousía : le fait de nommer un référent en implique l’existence du moins au niveau linguistique. Priscien de son côté, influencé par son arrière-plan platonicien, limite le verbum substantivum (calque de hyparktikòn rhḗma) au seul verbe sum, mais pour la première fois dans l’histoire de la linguistique ancienne transpose l’adjectif substantivum de la classe verbale à la classe nominale : il récupère ainsi d’une certaine manière l’héritage d’Apollonius et en même temps resserre à l’extrême les liens entre le nom et la substance.
Ensemble-based topological entropy calculation (E-tec)
Authors: Roberts Eric , Sindi Suzanne , Smith Spencer A. , Mitchell Kevin A.
Published: January 2019

Topological entropy measures the number of distinguishable orbits in a dynamical system, thereby quantifying the complexity of chaotic dynamics. One approach to computing topological entropy in a two-dimensional space is to analyze the collective motion of an ensemble of system trajectories taking into account how trajectories “braid” around one another. In this spirit, we introduce the Ensemble-based Topological Entropy Calculation, or E-tec, a method to derive a lower-bound on topological entropy of two-dimensional systems by considering the evolution of a “rubber band” (piece-wise linear curve) wrapped around the data points and evolving with their trajectories. The topological entropy is bounded below by the exponential growth rate of this band. We use tools from computational geometry to track the evolution of the rubber band as data points strike and deform it. Because we maintain information about the configuration of trajectories with respect to one another, updating the band configuration is performed locally, which allows E-tec to be more computationally efficient than some competing methods. In this work, we validate and illustrate many features of E-tec on a chaotic lid-driven cavity flow. In particular, we demonstrate convergence of E-tec’s approximation with respect to both the number of trajectories (ensemble size) and the duration of trajectories in time.
Integral partition bounds for fast and effective screening of general one-, two-, and many-electron integrals
Authors: Thompson Travis H. , Ochsenfeld Christian
Published: January 2019

We introduce tight upper bounds for a variety of integrals appearing in electronic structure theories. These include electronic interaction integrals involving any number of electrons and various integral kernels such as the ubiquitous electron repulsion integrals and the three- and four-electron integrals found in explicitly correlated methods. Our bounds are also applicable to the one-electron potential integrals that appear in great number in quantum mechanical (QM), mixed quantum and molecular mechanical (QM/MM), and semi-numerical methods. The bounds are based on a partitioning of the integration space into balls centered around electronic distributions and their complements. Such a partitioning leads directly to equations for rigorous extents, which we solve for shell pair distributions containing shells of Gaussian basis functions of arbitrary angular momentum. The extents are the first general rigorous formulation we are aware of, as previous definitions are based on the inverse distance operator 1/r12 and typically only rigorous for simple spherical Gaussians. We test our bounds for six different integral kernels found throughout quantum chemistry, including exponential, Gaussian, and complementary error function based forms. We compare to previously developed estimates on the basis of significant integral counts and their usage in both explicitly correlated second-order Møller-Plesset theory (MP2-F12) and density functional theory calculations employing screened Hartree-Fock exchange.
Auxetic crystals under stress: Peering into their mechanics using x-rays
Authors: Murray Conal E.
Published: January 2019

The discovery of auxetic behavior (negative Poisson's ratio) within elements and alloys had focused attention on their elastic anisotropy in an effort to understand the range of crystal orientations that manifest this property. A comparison of elastic constant data to atomistic models based on pair-wise, central force models provides key insights into deformation behavior of cubic crystals over a wide range of anisotropy, including, for the first time, those with Zener anisotropy ratios less than 1. A simple criterion is derived which dictates all cases in which a crystal whose atomic ordering obeys cubic symmetry will display auxetic deformation, where the extrema in Poisson's ratio involves (110) orientations. In the field of stress determination through x-ray diffraction, these findings also shed light on strain anisotropy in polycrystalline materials, where the elastic incompatibility between adjacent grains alters their overall deformation. By applying these same atomistic models, we can predict the Voigt/Reuss weighting fractions associated with Kröner limit x-ray elastic constants for cubic materials, a necessary component in quantifying stress using diffraction data. We also establish that greater elastic anisotropy in a constituent crystal leads to a more rigid mechanical response in the corresponding polycrystalline aggregate, with implications for auxetic crystal ensembles.
Nonvolatile voltage controlled molecular spin state switching
Authors: Hao G. , Mosey A. , Jiang X. , Yost A. J. , Sapkota K. R. , Wang G. T. , Zhang X. , Zhang J. , N'Diaye A. T. , Cheng R. , Xu X. , Dowben P. A.
Published: January 2019

Voltage-controlled room temperature isothermal reversible spin crossover switching of [Fe{H2B(pz)2}2(bipy)] thin films is demonstrated. This isothermal switching is evident in thin film bilayer structures where the molecular spin crossover film is adjacent to a molecular ferroelectric. The adjacent molecular ferroelectric, either polyvinylidene fluoride hexafluoropropylene or croconic acid (C5H2O5), appears to lock the spin crossover [Fe{H2B(pz)2}2(bipy)] molecular complex largely in the low or high spin state depending on the direction of ferroelectric polarization. In both a planar two terminal diode structure and a transistor structure, the voltage controlled isothermal reversible spin crossover switching of [Fe{H2B(pz)2}2(bipy)] is accompanied by a resistance change and is seen to be nonvolatile, i.e., retained in the absence of an applied electric field. The result appears general, as the voltage controlled nonvolatile switching can be made to work with two different molecular ferroelectrics: croconic acid and polyvinylidene fluoride hexafluoropropylene.
Bifurcation in the angular velocity of a circular disk propelled by symmetrically distributed camphor pills
Authors: Koyano Yuki , Kitahata Hiroyuki , Gryciuk Marian , Akulich Nadejda , Gorecka Agnieszka , Malecki Maciej , Gorecki Jerzy
Published: January 2019

We studied rotation of a disk propelled by a number of camphor pills symmetrically distributed at its edge. The disk was put on a water surface so that it could rotate around a vertical axis located at the disk center. In such a system, the driving torque originates from surface tension difference resulting from inhomogeneous surface concentration of camphor molecules released from the pills. Here, we investigated the dependence of the stationary angular velocity on the disk radius and on the number of pills. The work extends our previous study on a linear rotor propelled by two camphor pills [Y. Koyano et al., Phys. Rev. E 96, 012609 (2017)]. It was observed that the angular velocity dropped to zero after a critical number of pills was exceeded. Such behavior was confirmed by a numerical model of time evolution of the rotor. The model predicts that, for a fixed friction coefficient, the speed of pills can be accurately represented by a function of the linear number density of pills. We also present bifurcation analysis of the conditions at which the transition between a standing and a rotating disk appears.
Comparing the anomalous Hall effect and the magneto-optical Kerr effect through antiferromagnetic phase transitions in Mn3Sn
Authors: Balk A. L. , Sung N. H. , Thomas S. M. , Rosa P. F. S. , McDonald R. D. , Thompson J. D. , Bauer E. D. , Ronning F. , Crooker S. A.
Published: January 2019

In the non-collinear antiferromagnet Mn3Sn, we compare simultaneous measurements of the anomalous Hall effect (AHE) and the magneto-optical Kerr effect (MOKE) through two magnetic phase transitions: the high-temperature paramagnetic/antiferromagnetic (AF) phase transition at the Néel temperature (TN ≈ 420 K) and a lower-temperature incommensurate magnetic ordering at T1 ≈ 270 K. While both the AHE and MOKE are sensitive to the same underlying symmetries of the AF non-collinear spin order, we find that the transition temperatures measured by these two techniques unexpectedly differ by approximately 10 K. Moreover, the applied magnetic field at which the AF order reverses is significantly larger when measured by MOKE than when measured by AHE. These results point to a difference between the bulk and surface magnetic properties of Mn3Sn.
Spectroscopic identification of the low-lying electronic states of S2 molecule
Authors: Qin Zhengbo , Wang Lin , Cong Ran , Jiao Chengxiang , Zheng Xianfeng , Cui Zhifeng , Tang Zichao
Published: January 2019

As is well-known, the S2 molecule is a ubiquitous intermediate in the combustion, atmosphere, and interstellar space. The six low-lying bound states of S2 have been characterized via photoelectron velocity map imaging and a high-level multi-reference configuration interaction method with the Davidson correction. Spectroscopic constants have been extracted by fitting the potential energy curves extrapolated to the complete basis set limit with a series of Dunning’s correlation-consistent basis sets: aug-cc-pV(Q, 5)Z. The calculated spectroscopic parameters well reproduce the experimental results in this work. On the basis of the theoretical calculations, Franck-Condon simulations are performed to assign six adjacent electronic states, especially for three higher overlapping electronic states (c1Σu−, A′3Δu, and A3Σu+). The dissociation energy De of the S2− is evaluated to be 4.111 (4) eV in this work, in agreement with the theoretical prediction (4.056 eV).
Controlled Stochastic Amplification of a Weak Signal in a Superconducting Quantum Interferometer
Authors: Turutanov O. G. , Lyakhno V. Yu. , Pivovar M. E. , Shnyrkov V. I.
Published: January 2019

In a single-junction niobium superconducting quantum interferometer (RF SQUID loop), a weak low-frequency harmonic signal is amplified when quasi-white Gaussian noise magnetic flux is applied to the loop; such amplification is due to stochastic resonance (SR). We have experimentally shown that if the suboptimal flux noise intensity is insufficient for SR, the mean rate of transitions between the metastable states of the loop, and thus the signal gain, can be controlled by an additional deterministic alternating magnetic flux with frequency being much higher than that of the useful signal to provide the maximal possible gain. The frequency characteristics of a multi-tone composite signal amplification in the cases of controlled stochastic amplification and “pure” SR are compared to each other.
Self-consistent simulation of transport and turbulence in tokamak edge plasma by coupling SOLPS-ITER and BOUT++
Authors: Zhang D. R. , Chen Y. P. , Xu X. Q. , Xia T. Y.
Published: January 2019

The status of coupling the fluid plasma/neutral 2D transport code SOLPS-ITER and the fluid 3D turbulence code BOUT++ is reported. Both codes simulated the same region, which is from several cm inside the magnetic separatrix to the far scrape-off layer (SOL). Compared to the profile evolution time scale, the characteristic time scale of the turbulence is quite short. For the turbulence code BOUT++, the time scale is around 10−6 s. However, for the transport code SOLPS-ITER, the time scale is around 10−3–10−2 s. An iterative scheme is used that each system is evolved on its own characteristic time scale. SOLPS-ITER can provide the background profiles of density, ion, and electron temperature to BOUT++. In turn, BOUT++ can provide the corresponding radial transport coefficients to SOLPS-ITER. The coupling has involved the ion density, ion temperature, and electron temperature. After several steps of iteration, the profiles of density, ion, and electron temperature show fluctuations, and the differences of the changes between two consecutive profiles are getting smaller and smaller. Finally, the self-consistent solutions of turbulence and transport can be obtained.
Besov classes on finite and infinite dimensional spaces
Authors: Kosov E. D.
Published: January 2019

We give an equivalent description of Besov spaces in terms of a new modulus of continuity. Then we use a similar approach to introduce Besov classes on an infinite-dimensional space endowed with a Gaussian measure.

Bibliography: 25 titles.
Topological classification of Liouville foliations for the Kovalevskaya integrable case on the Lie algebra so(4)
Authors: Kibkalo V. A.
Published: January 2019

This paper is concerned with the topology of the Liouville foliation in the analogue of the Kovalevskaya integrable case on the Lie algebra

. The Fomenko-Zieschang invariants (that is, marked molecules) for this foliation are calculated on each nonsingular iso-energy surface. A detailed description of the resulting stratification of the three- dimensional space of parameters of the iso-energy surfaces is given.

Bibliography: 23 titles.
Accelerating changes in ice mass within Greenland, and the ice sheet’s sensitivity to atmospheric forcing
Authors: Bevis Michael , Harig Christopher , Khan Shfaqat A. , Brown Abel , Simons Frederik J. , Willis Michael , Fettweis Xavier , van den Broeke Michiel R. , Madsen Finn Bo , Kendrick Eric , Caccamise Dana J. , van Dam Tonie , Knudsen Per , Nylen Thomas
Published: January 2019

Significance

The recent deglaciation of Greenland is a response to both oceanic and atmospheric forcings. From 2000 to 2010, ice loss was concentrated in the southeast and northwest margins of the ice sheet, in large part due to the increasing discharge of marine-terminating outlet glaciers, emphasizing the importance of oceanic forcing. However, the largest sustained (∼10 years) acceleration detected by Gravity Recovery and Climate Experiment (GRACE) occurred in southwest Greenland, an area largely devoid of such glaciers. The sustained acceleration and the subsequent, abrupt, and even stronger deceleration were mostly driven by changes in air temperature and solar radiation. Continued atmospheric warming will lead to southwest Greenland becoming a major contributor to sea level rise.
A ligand motif enables differential vascular targeting of endothelial junctions between brain and retina
Authors: Tang Fenny H. F. , Staquicini Fernanda I. , Teixeira André A. R. , Michaloski Jussara S. , Namiyama Gislene M. , Taniwaki Noemi N. , Setubal João C. , da Silva Aline M. , Sidman Richard L. , Pasqualini Renata , Arap Wadih , Giordano Ricardo J.
Published: January 2019

Significance

Endothelial barriers are essential components of blood vessels and particularly important in brain and retina, which are protected by barriers so efficient that almost all metabolites have to be actively transported across them. We provide evidence that short peptides containing a motif rich in amino acids with aromatic and positively charged side chains target specifically blood vessels of the brain but not of other tissues. Using electron microscopy, phage could be visualized bound to the endothelial junction of these vessels, demonstrating how these two techniques can be combined to identify a supramolecular phage target in vivo. Surprisingly, this peptide motif does not bind to vessels in the retina, implying a previously unknown molecular difference between these endothelial junctions.
Influence of young adult cognitive ability and additional education on later-life cognition
Authors: Kremen William S. , Beck Asad , Elman Jeremy A. , Gustavson Daniel E. , Reynolds Chandra A. , Tu Xin M. , Sanderson-Cimino Mark E. , Panizzon Matthew S. , Vuoksimaa Eero , Toomey Rosemary , Fennema-Notestine Christine , Hagler Donald J. , Fang Bin , Dale Anders M. , Lyons Michael J. , Franz Carol E.
Published: January 2019

How and when education improves cognitive capacity is an issue of profound societal importance. Education and later-life education-related factors, such as occupational complexity and engagement in cognitive-intellectual activities, are frequently considered indices of cognitive reserve, but whether their effects are truly causal remains unclear. In this study, after accounting for general cognitive ability (GCA) at an average age of 20 y, additional education, occupational complexity, or engagement in cognitive-intellectual activities accounted for little variance in late midlife cognitive functioning in men age 56–66 (
n
= 1009). Age 20 GCA accounted for 40% of variance in the same measure in late midlife and approximately 10% of variance in each of seven cognitive domains. The other factors each accounted for <1% of the variance in cognitive outcomes. The impact of these other factors likely reflects reverse causation—namely, downstream effects of early adult GCA. Supporting that idea, age 20 GCA, but not education, was associated with late midlife cortical surface area (
n
= 367). In our view, the most parsimonious explanation of our results, a meta-analysis of the impact of education, and epidemiologic studies of the Flynn effect is that intellectual capacity gains due to education plateau in late adolescence/early adulthood. Longitudinal studies with multiple cognitive assessments before completion of education would be needed to confirm this speculation. If cognitive gains reach an asymptote by early adulthood, then strengthening cognitive reserve and reducing later-life cognitive decline and dementia risk may really begin with improving educational quality and access in childhood and adolescence.
Dopamine modulates the reward experiences elicited by music
Authors: Ferreri Laura , Mas-Herrero Ernest , Zatorre Robert J. , Ripollés Pablo , Gomez-Andres Alba , Alicart Helena , Olivé Guillem , Marco-Pallarés Josep , Antonijoan Rosa M. , Valle Marta , Riba Jordi , Rodriguez-Fornells Antoni
Published: January 2019

Significance

In everyday life humans regularly seek participation in highly complex and pleasurable experiences such as music listening, singing, or playing, that do not seem to have any specific survival advantage. The question addressed here is to what extent dopaminergic transmission plays a direct role in the reward experience (both motivational and hedonic) induced by music. We report that pharmacological manipulation of dopamine modulates musical responses in both positive and negative directions, thus showing that dopamine causally mediates musical reward experience.
Hagfish from the Cretaceous Tethys Sea and a reconciliation of the morphological–molecular conflict in early vertebrate phylogeny
Authors: Miyashita Tetsuto , Coates Michael I. , Farrar Robert , Larson Peter , Manning Phillip L. , Wogelius Roy A. , Edwards Nicholas P. , Anné Jennifer , Bergmann Uwe , Palmer A. Richard , Currie Philip J.
Published: January 2019

Hagfish depart so much from other fishes anatomically that they were sometimes considered not fully vertebrate. They may represent: (i) an anatomically primitive outgroup of vertebrates (the morphology-based craniate hypothesis); or (ii) an anatomically degenerate vertebrate lineage sister to lampreys (the molecular-based cyclostome hypothesis). This systematic conundrum has become a prominent case of conflict between morphology- and molecular-based phylogenies. To date, the fossil record has offered few insights to this long-branch problem or the evolutionary history of hagfish in general, because unequivocal fossil members of the group are unknown. Here, we report an unequivocal fossil hagfish from the early Late Cretaceous of Lebanon. The soft tissue anatomy includes key attributes of living hagfish: cartilages of barbels, postcranial position of branchial apparatus, and chemical traces of slime glands. This indicates that the suite of characters unique to living hagfish appeared well before Cretaceous times. This new hagfish prompted a reevaluation of morphological characters for interrelationships among jawless vertebrates. By addressing nonindependence of characters, our phylogenetic analyses recovered hagfish and lampreys in a clade of cyclostomes (congruent with the cyclostome hypothesis) using only morphological data. This new phylogeny places the fossil taxon within the hagfish crown group, and resolved other putative fossil cyclostomes to the stem of either hagfish or lamprey crown groups. These results potentially resolve the morphological–molecular conflict at the base of the Vertebrata. Thus, assessment of character nonindependence may help reconcile morphological and molecular inferences for other major discords in animal phylogeny.
Phosphoproteomics of
Arabidopsis
Highly ABA-Induced1 identifies AT-Hook–Like10 phosphorylation required for stress growth regulation
Authors: Wong Min May , Bhaskara Govinal Badiger , Wen Tuan-Nan , Lin Wen-Dar , Nguyen Thao Thi , Chong Geeng Loo , Verslues Paul E.
Published: January 2019

The clade A protein phosphatase 2C Highly ABA-Induced 1 (HAI1) plays an important role in stress signaling, yet little information is available on HAI1-regulated phosphoproteins. Quantitative phosphoproteomics identified phosphopeptides of increased abundance in
hai1-2
in unstressed plants and in plants exposed to low-water potential (drought) stress. The identity and localization of the phosphoproteins as well as enrichment of specific phosphorylation motifs indicated that these phosphorylation sites may be regulated directly by HAI1 or by HAI1-regulated kinases including mitogen-activated protein kinases, sucrose non-fermenting–related kinase 2, or casein kinases. One of the phosphosites putatively regulated by HAI1 was S313/S314 of AT-Hook–Like10 (AHL10), a DNA-binding protein of unclear function. HAI1 could directly dephosphorylate AHL10 in vitro, and the level of
HAI1
expression affected the abundance of phosphorylated AHL10 in vivo. AHL10 S314 phosphorylation was critical for restriction of plant growth under low-water potential stress and for regulation of jasmonic acid and auxin-related gene expression as well as expression of developmental regulators including
Shootmeristemless
. These genes were also misregulated in
hai1-2
. AHL10 S314 phosphorylation was required for AHL10 complexes to form foci within the nucleoplasm, suggesting that S314 phosphorylation may control AHL10 association with the nuclear matrix or with other transcriptional regulators. These data identify a set of HAI1-affected phosphorylation sites, show that HAI1-regulated phosphorylation of AHL10 S314 controls AHL10 function and localization, and indicate that HAI1-AHL10 signaling coordinates growth with stress and defense responses.
Predicting runtimes of bioinformatics tools based on historical data: five years of Galaxy usage
Authors: Tyryshkina Anastasia , Coraor Nate , Nekrutenko Anton
Published: January 2019

Motivation

One of the many technical challenges that arises when scheduling bioinformatics analyses at scale is determining the appropriate amount of memory and processing resources. Both over- and under-allocation leads to an inefficient use of computational infrastructure. Over allocation locks resources that could otherwise be used for other analyses. Under-allocation causes job failure and requires analyses to be repeated with a larger memory or runtime allowance. We address this challenge by using a historical dataset of bioinformatics analyses run on the Galaxy platform to demonstrate the feasibility of an online service for resource requirement estimation.

Results

Here we introduced the Galaxy job run dataset and tested popular machine learning models on the task of resource usage prediction. We include three popular forest models: the extra trees regressor, the gradient boosting regressor and the random forest regressor, and find that random forests perform best in the runtime prediction task. We also present two methods of choosing walltimes for previously unseen jobs. Quantile regression forests are more accurate in their predictions, and grant the ability to improve performance by changing the confidence of the estimates. However, the sizes of the confidence intervals are variable and cannot be absolutely constrained. Random forest classifiers address this problem by providing control over the size of the prediction intervals with an accuracy that is comparable to that of the regressor. We show that estimating the memory requirements of a job is possible using the same methods, which as far as we know, has not been done before. Such estimation can be highly beneficial for accurate resource allocation.

Availability and implementation

Source code available at https://github.com/atyryshkina/algorithm-performance-analysis, implemented in Python.

Supplementary information

Supplementary data are available at Bioinformatics online.
Does an interactive trust-enhanced electronic consent improve patient experiences when asked to share their health records for research? A randomized trial
Authors: Harle Christopher A , Golembiewski Elizabeth H , Rahmanian Kiarash P , Brumback Babette , Krieger Janice L , Goodman Kenneth W , Mainous Arch G , Moseley Ray E
Published: January 2019

Objective

In the context of patient broad consent for future research uses of their identifiable health record data, we compare the effectiveness of interactive trust-enhanced e-consent, interactive-only e-consent, and standard e-consent (no interactivity, no trust enhancement).

Materials and Methods

A randomized trial was conducted involving adult participants making a scheduled primary care visit. Participants were randomized into 1 of the 3 e-consent conditions. Primary outcomes were patient-reported satisfaction with and subjective understanding of the e-consent. Secondary outcomes were objective knowledge, perceived voluntariness, trust in medical researchers, consent decision, and time spent using the application. Outcomes were assessed immediately after use of the e-consent and at 1-week follow-up.

Results

Across all conditions, participants (N = 734) reported moderate-to-high satisfaction with consent (mean 4.3 of 5) and subjective understanding (79.1 of 100). Over 94% agreed to share their health record data. No statistically significant differences in outcomes were observed between conditions. Irrespective of condition, black participants and those with lower education reported lower satisfaction, subjective understanding, knowledge, perceived voluntariness, and trust in medical researchers, as well as spent more time consenting.

Conclusions

A large majority of patients were willing to share their identifiable health records for research, and they reported positive consent experiences. However, incorporating optional additional information and messages designed to enhance trust in the research process did not improve consent experiences. To improve poorer consent experiences of racial and ethnic minority participants and those with lower education, other novel consent technologies and processes may be valuable. (An Interactive Patient-Centered Consent for Research Using Medical Records; NCT03063268)
An opalized oak from Clover Creek, Lincoln County, Idaho c.1895
Authors: Viney Mike , Dietrich Dagmar , Mills Jim
Published: January 2019

According to mineralogical literature, some of the finest opalized wood in the world was discovered in Idaho c.1895, originating in a unique deposit along Clover Creek in Lincoln County (now Gooding County). The American mineral dealer Dr A. E. Foote acquired and processed the bulk of the discovery into specimens that were advertised between 1896 and 1904. Over a period of four years, we have identified sixteen natural history museums in Europe, North America, and Australia in possession of Clover Creek opalized oak today. Many museum acquisitions and the fossil’s taxonomic affinity, Quercinium pliocaenicum, resulted from collective networking between mineral dealers, private collectors and scientists – evidence of a common interest among a diversity of people – contributing the best specimens for museums of natural history.
Depressive Symptoms and Suicidality in Adolescents Using e-Cigarettes and Marijuana: A Secondary Data Analysis From the Youth Risk Behavior Survey
Authors: Chadi Nicholas , Li Guilin , Cerda Natalie , Weitzman Elissa R.
Published: January 2019

Objectives:

E-cigarette use has increased dramatically among adolescents in the past 5 years alongside a steady increase in daily use of marijuana. This period coincides with a historic rise in depression and suicidal ideation among adolescents. In this study, we describe the associations between e-cigarette and marijuana use and depressive symptoms and suicidality in a large nationally representative sample of high school students.

Methods:

We used data from the 2 most recent waves (2015 and 2017) of the Youth Risk Behavior Survey. Our sample (n = 26,821) included only participants with complete information for age, sex, race/ethnicity, and exposure to e-cigarettes and marijuana (89.5% of survey respondents). We performed multivariate logistic regressions to explore the associations between single or dual use of e-cigarette and marijuana and depressive and suicidal symptoms in the past year adjusting for relevant confounders.

Results:

E-cigarette-only use was reported in 9.1% of participants, marijuana-only use in 9.7%, and dual e-cigarette/marijuana use in 10.2%. E-cigarette-only use (vs no use) was associated with increased odds of reporting suicidal ideation (adjusted odds ratio [AOR]:1.23, 95% CI 1.03–1.47) and depressive symptoms (AOR: 1.37, 95% CI 1.19–1.57), which was also observed with marijuana-only use (AOR: 1.25, 95% CI 1.04–1.50 and AOR: 1.49, 95% CI 1.27–1.75) and dual use (AOR: 1.28, 95% CI 1.06–1.54 and AOR: 1.62, 95% CI 1.39–1.88).

Conclusions:

Youth with single and dual e-cigarette and marijuana use had increased odds of reporting depressive symptoms and suicidality compared to youth who denied use. There is a need for effective prevention and intervention strategies to help mitigate adverse mental health outcomes in this population.
Outcomes of Surgical Treatment of Periprosthetic Acetabular Fractures
Authors: Hickerson Lindsay E. , Zbeda Robert M. , Gadinsky Naomi E. , Wellman David S. , Helfet David L.
Published: January 2019

Periprosthetic acetabular fractures sustained following acute trauma after total hip arthroplasty are rare and historically have poor outcomes. This article reviews 5 cases and the treatment algorithm used by a single orthopaedic surgeon specializing in acetabular fracture care with a co-surgeon specializing in arthroplasty. Team-based surgical management with arthroplasty- and fracture-trained surgeon(s) is paramount for optimal outcome. The following approach resulted in satisfactory outcomes without need for revision implants. In fracture patterns with columnar involvement, the columns were restored with plates and screws. In fracture patterns with wall involvement, the acetabular component functioned as a template for wall reconstruction with use of a buttress plate. The acetabular component was revised when deemed loose during stress of the component through the surgical approach used for fracture fixation.
Is Wearable Technology Part of the Future of Orthopedic Health Care?
Authors: Zarowin Joseph , Warnick Eugene , Mangan John , Nicholson Kristen , Goyal Dhruv K.C. , Galetta Matthew S. , Fang Taolin , Schroeder Gregory D. , Kepler Christopher K. , Vaccaro Alexander R.
Published: January 2019

Wearable technology is an exciting industry that has gained exponential traction over the past few years. This technology allows individuals to track personal health and fitness parameters and is becoming more and more precise with modern advancements. As these devices continue to increase in accuracy and gain further utilities in health monitoring, their potential to influence orthopedic care will also grow. Orthopedic surgeons may use this technology to monitor the perioperative course of their patients, who can remotely communicate various parameters related to care without needing to physically be seen by their providers. Wearable devices, while of course promising in the field of medicine, still have limitations that must be overcome before they can widely be adopted into orthopedic care. Our goal is to review current wearables on the market, discuss their potential applications in health care, and postulate their future use in orthopedic care.
Treatment of Periprosthetic Patella Fractures Using a Lag Screw and Neutralization Plate Construct: A Novel Surgical Technique
Authors: Lindemeier Samual C. , Brazier Brett G. , Ruhland Ethan D. , Cochran Jason M.
Published: January 2019

There currently is no optimal technique for open reduction internal fixation of peri-prosthetic patella fractures which is likely due to the infrequent nature of these injuries. In this report, we present a novel fixation method for transverse peri-prosthetic patella fractures that was utilized in 3 knees with resurfaced patellas in 2 patients and has yielded good clinical results.
Readmission Diagnoses After Pediatric Severe Sepsis Hospitalization*
Authors: Carlton Erin F. , Kohne Joseph G. , Shankar-Hari Manu , Prescott Hallie C.
Published: January 2019

Objectives:

Severe sepsis is a significant cause of healthcare use and morbidity among pediatric patients, but little is known about readmission diagnoses. We sought to determine the most common readmission diagnoses after pediatric severe sepsis, the extent to which post-sepsis readmissions may be potentially preventable, and whether patterns of readmission diagnoses differ compared with readmissions after other common acute medical hospitalizations.

Design:

Observational cohort study.

Setting:

National Readmission Database (2013–2014), including all-payer hospitalizations from 22 states.

Patients:

Four-thousand five-hundred twenty-eight pediatric severe sepsis hospitalizations, matched by age, gender, comorbidities, and length of stay to 4,528 pediatric hospitalizations for other common acute medical conditions.

Interventions:

None.

Measurements and Main Results:

We compared rates of 30-day all cause, diagnosis-specific, and potentially preventable hospital readmissions using McNemar’s chi-square tests for paired data. Among 5,841 eligible pediatric severe sepsis hospitalizations with live discharge, 4,528 (77.5%) were matched 1:1 to 4,528 pediatric hospitalizations for other acute medical conditions. Of 4,528 matched sepsis hospitalizations, 851 (18.8% [95% CI, 16.0–18.2]) were rehospitalized within 30 days, compared with 775 (17.1% [95% CI, 17.1–20.0]) of matched hospitalizations for other causes (p = 0.02). The most common readmission diagnoses were chemotherapy, device complications, and sepsis, all of which were several-fold higher after sepsis versus after matched nonsepsis hospitalization. Only 11.5% of readmissions were for ambulatory care sensitive conditions compared with 23% of rehospitalizations after common acute medical conditions.

Conclusions:

More than one in six children surviving severe sepsis were rehospitalized within 30 days, most commonly for maintenance chemotherapy, medical device complications, or recurrent sepsis. Only a small proportion of readmissions were for ambulatory care sensitive conditions.
Antibiotics Versus No Antibiotics for Acute Uncomplicated Diverticulitis: A Systematic Review and Meta-analysis
Authors: Desai Madhav , Fathallah Jihan , Nutalapati Venkat , Saligram Shreyas
Published: January 2019

BACKGROUND:

Antibiotics are routinely used for diverticulitis irrespective of severity. Current practice guidelines favor against the use of antibiotics for acute uncomplicated diverticulitis.

OBJECTIVE:

We performed a systematic review and meta-analysis to examine the role of antibiotic use in an episode of uncomplicated diverticulitis.

DATA SOURCES:

PubMed/Medline, Embase, Scopus, and Cochrane were used.

STUDY SELECTION:

Eligible studies included those with patients with uncomplicated diverticulitis receiving any antibiotics compared with patients not receiving any antibiotics (or observed alone).

MAIN OUTCOME MEASURES:

Pooled odds rate of total complications, treatment failure, recurrent diverticulitis, readmission rate, sigmoid resection, mortality rate, and length of stay were measured.

RESULTS:

Of 1050 citations reviewed, 7 studies were eligible for the analysis. There were total of 2241 patients: 895 received antibiotics (mean age = 59.1 y; 38% men) and 1346 did not receive antibiotics (mean age = 59.4 y; 37% men). Antibiotics were later added in 2.7% patients who initially were observed off antibiotics. Length of hospital stay was not significantly different among either group (no antibiotics = 3.1 d vs antibiotics = 4.5 d; p = 0.20). Pooled rate of recurrent diverticulitis was not significantly different among both groups (pooled OR = 1.27 (95%, CI 0.90–1.79); p = 0.18). Rate of total complications (pooled OR = 1.99 (95% CI, 0.66–6.01); p = 0.22), treatment failure (pooled OR = 0.68 (95% CI, 0.42–1.09); p = 0.11), readmissions (pooled OR = 0.75 (95% CI, 0.44–1.30); p = 0.31). and patients who required sigmoid resection (pooled OR = 3.37 (95% CI, 0.65–17.34); p = 0.15) were not significantly different among patients who received antibiotics and those who did not. Mortality rates were 4 of 1310 (no-antibiotic group) versus 4 of 863 (antibiotic group).

LIMITATIONS:

Only 2 randomized controlled studies were available and there was high heterogeneity in existing data.

CONCLUSIONS:

This meta-analysis of current literature shows that patients with uncomplicated diverticulitis can be monitored off antibiotics.
Revascularization of Free Skin Grafts Overlying Modified Hughes Tarsoconjunctival Flaps Monitored Using Laser-Based Techniques
Authors: Berggren Johanna , Tenland Kajsa , Ansson Cu Dinh , Dahlstrand Ulf , Sheikh Rafi , Hult Jenny , Engelsberg Karl , Lindstedt Sandra , Malmsjö Malin
Published: January 2019

Purpose:

It has recently been shown that the flap pedicle does not supply blood to a tarsoconjunctival graft in the modified Hughes procedure in patients. This raises questions concerning the rate of revascularization of the free skin graft commonly used to reconstruct the anterior lamella. The aim of this study was, thus, to monitor the course of revascularization in free skin grafts overlying modified Hughes tarsoconjunctival flaps, using laser-based techniques.

Methods:

Free skin grafts from the upper eyelid or upper arm in 9 patients were used to cover a tarsoconjunctival flap according to the modified Hughes procedure. Blood perfusion was monitored using laser speckle contrast imaging, and vascular reactivity was studied with laser Doppler velocimetry after heating the tissue to 44°C. Measurements were made at the time of surgery (baseline) and at 1, 3, 8, and 16 weeks postoperatively.

Results:

The gradual increase in perfusion of the free skin grafts during the healing process indicates revascularization. A slight increase in perfusion was seen already after 1 week. Perfusion reached 50% of the baseline after 3 weeks, and complete restoration of perfusion was seen after 8 weeks. The vascular function monitored with heat-induced hyperemia increased in a similar fashion.

Conclusions:

Full-thickness skin grafts revascularize within 3 to 8 weeks, despite overlying a tarsoconjunctival flap, which has recently been reported to be avascular. This provides further evidence that it should be possible to repair large eyelid defects using free full-thickness eyelid grafts.
Gerofit Prehabilitation Pilot Program: Preparing Frail Older Veterans for Surgery
Authors: Dworsky Jill Q. , Castle Steven C. , Lee Cathy C. , Singh Sumit P. , Russell Marcia M.
Published: January 2019

Older Veterans are increasingly undergoing surgery and are at particularly high risk of postoperative morbidity and mortality. Prehabilitation has emerged as a method to improve postoperative outcomes by enhancing the patient's preoperative condition. We present data from our prehabilitation pilot project and plans for expansion and dissemination of a nationwide quality improvement effort. The infrastructure of the existing Veterans Affairs (VA) Gerofit health and exercise program was used to create our pilot. Pilot patients were screened for risk of postoperative functional decline, assessed for baseline physical function, enrolled in a personalized exercise program, and prepared to transition into the hospital for surgery. Patients (n = 9) completed an average of 17.7 prehabilitation sessions. After completing the program, 55.6% improved in ≥2 of the 5 fitness assessments completed. Postoperative outcomes including complications, 30-day mortality, and 30-day readmissions were better than predicted by the National Surgical Quality Improvement Program Surgical Risk Calculator. We have obtained institutional support for implementing similar prehabilitation programs at VA hospitals nationally through our designation as a VA Patient Safety Center for Inquiry. This is the first multi-institutional prehabilitation program for frail, older Veterans and represents an essential step toward optimizing surgical care for this vulnerable population.
Steroids for Acute Vestibular Neuronitis—the Earlier the Treatment, the Better the Outcome?
Authors: Sjögren Julia , Magnusson Måns , Tjernström Fredrik , Karlberg Mikael
Published: January 2019

Objective:

To present findings that suggest steroid treatment within 24 hours of onset of vestibular neuronitis results in better restitution of vestibular function than treatment between 25 and 72 hours.

Patients:

Thirty-three consecutive patients (17 men, 16 women, mean age 57 yr, range 17–85 yr) with acute vestibular neuronitis and treated with steroids within 72 hours after symptom onset. Patients were divided into two groups depending on if they were treated within the first 24 hours or not.

Interventions:

Oral prednisolone 50 mg/d for 5 days with tapering of doses for the next 5 days, or combined with initial intravenous betamethasone 8 mg the first 1 to 2 days if the patient was nauseous.

Main Outcome Measures:

Proportion of patients with normal caloric test result (canal paresis value < 32%) at follow-up after 3 or 12 months.

Results:

All 9 patients (100%) treated within 24 hours from onset of vestibular neuronitis had normal caloric test results at follow-up after 3 months, as compared with 14 of 24 (58%) of the patients treated between 25 and 72 hours (p < 0,05, Fisher's exact test).

Conclusions:

The timing of steroid treatment of vestibular neuronitis may be of importance for subsequent vestibular restitution, and hence, for both time to recovery and late symptoms according to the literature.
Medical Malpractice of Vestibular Schwannoma: A 40-Year Review of the United States Legal Databases
Authors: Birkenbeuel Jack , Vu Kimberly , Lehrich Brandon M. , Abouzari Mehdi , Cheung Dillon , Khosravi Pooya , Sahyouni Ronald , Ziai Kasra , Moshtaghi Omid , Sahyouni Sammy , Djalilian Hamid R.
Published: January 2019

Objectives:

To analyze medical malpractice lawsuit trends pertaining to cases of vestibular schwannomas (VS).

Methods:

Two major computerized legal databases (LexisNexis and WestLaw) were queried and reviewed for evaluation of all the US state and federal court records from civil trials alleging malpractice between 1976 and 2016.

Results:

A total of 32 VS cases were identified. Allegations were divided into four categories: misdiagnosis/delayed diagnosis (47%), postoperative complications (44%), failure of informed consent or information sharing (16%), and other (3%). Postoperative complications included facial nerve paralysis, myocardial infarction, meningitis, and intracranial hemorrhage. Judgment amounts ranged from $300,000 to $2,000,000. The specialist type was specified for 24 of the 32 cases (75%): neurosurgeons (n = 9; 37%), neurotologists (n = 6; 25%), general otolaryngologists (n = 5; 21%), primary care physicians (n = 4; 17%), neurologists (n = 3; 12%), radiologists (n = 3; 12%), anesthesiologists (n = 2; 8%), radiation oncologists (n = 1; 4%), and general surgeon (n = 1; 4%). Of these 24 cases, (n = 9; 37%) two or more physicians were named as defendants in the lawsuit.

Conclusions:

Enhanced physician-patient communication, ensuring proper and adequate patient consent procedures, and proper documentation are good practices that may decrease the likelihood of lawsuits.