bluuebunny/crossref_metadata_2025 huggingface dataset:
Advanced tokamak investigations in full-tungsten ASDEX Upgrade
Authors: Bock A. , Doerk H. , Fischer R. , Rittich D. , Stober J. , Burckhart A. , Fable E. , Geiger B. , Mlynek A. , Reich M. , Zohm H. ,   ASDEX Upgrade Team
Published: May 2018

The appropriate tailoring of the q-profile is the key to accessing Advanced Tokamak (AT) scenarios, which are of great benefit to future all-metal fusion power plants. Such scenarios depend on low collisionality ν* which permits efficient external current drive and high amounts of intrinsic bootstrap current. At constant pressure, lowering of the electron density ne leads to a strong decrease in the collisionality with increasing electron temperature ν* ∼Te−3. Simultaneously, the conditions for low ne also benefit impurity accumulation. This paper reports on how radiative collapses due to central W accumulation were overcome by improved understanding of the changes to recycling and pumping, substantially expanded ECRH capacities for both heating and current drive, and a new solid W divertor capable of withstanding the power loads at low ne. Furthermore, it reports on various improvements to the reliability of the q-profile reconstruction. A candidate steady state scenario for ITER/DEMO (q95 = 5.3, βN = 2.7, fbs > 40%) is presented. The ion temperature profiles are steeper than predicted by TGLF, but nonlinear electromagnetic gyro-kinetic analyses with GENE including fast particle effects matched the experimental heat fluxes. A fully non-inductive scenario at higher q95 = 7.1 for current drive model validation is also discussed. The results show that non-inductive operation is principally compatible with full-metal machines.
Observation of strong Kondo like features and co-tunnelling in superparamagnetic GdCl3 filled 1D nanomagnets
Authors: Ncube S. , Coleman C. , de Sousa A. S. , Nie C. , Lonchambon P. , Flahaut E. , Strydom A. , Bhattacharyya S.
Published: May 2018

Filling of carbon nanotubes has been tailored over years to modify the exceptional properties of the 1-dimensional conductor for magnetic property based applications. Hence, such a system exploits the spin and charge property of the electron, analogous to a quantum conductor coupled to magnetic impurities, which poses an interesting scenario for the study of Kondo physics and related phenomena. We report on the electronic transport properties of MWNTs filled with GdCl3 nanomagnets, which clearly show the co-existence of Kondo correlation and cotunelling within the superparamagnetic limit. The Fermi liquid description of the Kondo effect and the interpolation scheme are fitted to the resistance-temperature dependence yielding the onset of the Kondo scattering temperature and a Kondo temperature for this nanocomposite, respectively. Cotunneling of conduction electrons interfering with a Kondo type interaction has been verified from the exponential decay of the intensity of the fano shaped nonzero bias anomalous conductance peaks, which also show strong resonant features observed only in GdCl3 filled MWNT devices. Hence, these features are explained in terms of magnetic coherence and spin-flip effects along with the competition between the Kondo effect and co-tunneling. This study raises a new possibility of tailoring magnetic interactions for spintronic applications in carbon nanotube systems.
Nonlinear electrical conductivity of ionic liquid modified WS2/EPDM field grading material
Authors: Han Peng , Zha Jun-Wei , Zheng Ming-Sheng , Li Hong-Yan , Wen Yong-Qiang , Dang Zhi-Min
Published: May 2018

In this work, a small amount of ionic liquids (ILs, 1-vinyl-3-ethylimidazolium tetrafluoroborate) was used to modify tungsten disulfide (WS2), and then, the modified WS2 was mixed with ethylene propylene diene monomer (EPDM) to obtain IL-WS2/EPDM composites with different IL contents. The content of WS2 in composites was determined from the result of our previous work. The nonlinear electrical conductivity of composites at 25 °C, 50 °C, and 80 °C was measured and analyzed subsequently. A small amount of ILs has an influence on the nonlinear property of composites, and the inflection point of the ternary composite can be controlled by changing IL contents. The direct current (DC) breakdown strength and thermal conductivity of composites were also measured and researched. Addition of ILs would decrease the breakdown strength of IL-WS2/EPDM composites.
One-dimensional thermal pressure-driven expansion of a pair cloud into an electron-proton plasma
Authors: Dieckmann M. E. , Alejo A. , Sarri G. , Folini D. , Walder R.
Published: May 2018

Recently, a filamentation instability was observed when a laser-generated pair cloud interacted with an ambient plasma. The magnetic field it drove was strong enough to magnetize and accelerate the ambient electrons. It is of interest to determine if and how pair cloud-driven instabilities can accelerate ions in the laboratory or in astrophysical plasma. For this purpose, the expansion of a localized pair cloud with the temperature 400 keV into a cooler ambient electron-proton plasma is studied by means of one-dimensional particle-in-cell simulations. The cloud's expansion triggers the formation of electron phase space holes that accelerate some protons to MeV energies. Forthcoming lasers might provide the energy needed to create a cloud that can accelerate protons.
Extraction of nonlinear waveform in turbulent plasma
Authors: Kin F. , Itoh K. , Fujisawa A. , Kosuga Y. , Sasaki M. , Yamada T. , Inagaki S. , Itoh S.-I. , Kobayashi T. , Nagashima Y. , Kasuya N. , Arakawa H. , Yamasaki K. , Hasamada K.
Published: May 2018

Streamers and their mediator have been known to exist in linear cylindrical plasmas [Yamada et al., Nat. Phys. 4, 721 (2008)]. Conditional averaging is applied to extract the nonlinear characteristics of a mediator, which has been simply treated as a linear wave. This paper reports that a mediator should have higher harmonic components generated by self-couplings, and the envelope of a streamer should be generated with not only fundamental but also higher harmonic components of the mediator. Moreover, both the mediator and the envelope of the streamer have common features with solitary waves, i.e., the height should increase inversely as the square of their localization width.
Atomistic minimal model for estimating profile of electrodeposited nanopatterns
Authors: Asgharpour Hassankiadeh Somayeh , Sadeghi Ali
Published: May 2018

We develop a computationally efficient and methodologically simple approach to realize molecular dynamics simulations of electrodeposition. Our minimal model takes into account the nontrivial electric field due a sharp electrode tip to perform simulations of the controllable coating of a thin layer on a surface with an atomic precision. On the atomic scale a highly site-selective electrodeposition of ions and charged particles by means of the sharp tip of a scanning probe microscope is possible. A better understanding of the microscopic process, obtained mainly from atomistic simulations, helps us to enhance the quality of this nanopatterning technique and to make it applicable in fabrication of nanowires and nanocontacts. In the limit of screened inter-particle interactions, it is feasible to run very fast simulations of the electrodeposition process within the framework of the proposed model and thus to investigate how the shape of the overlayer depends on the tip-sample geometry and dielectric properties, electrolyte viscosity, etc. Our calculation results reveal that the sharpness of the profile of a nano-scale deposited overlayer is dictated by the normal-to-sample surface component of the electric field underneath the tip.
Electron states in the field of charged impurities in two-dimensional Dirac systems (Review Article)
Authors: Gorbar E. V. , Gusynin V. P. , Sobol O. O.
Published: May 2018

We review the theoretical and experimental results connected with the electron states in two-dimensional Dirac systems paying a special attention to the atomic collapse in graphene. Two-electron bound states of a Coulomb impurity are considered too. A rather subtle role of a magnetic field in the supercritical charge problem in graphene is discussed. The electron states in the field of two equally charged impurities are studied and the conditions for supercritical instability to occur are determined. It is shown that the supercriticality of novel type is realized in gapped graphene with two unlikely charged impurities. For sufficiently large charges of impurities, it is found that the wave function of the occupied electron bound state of the highest energy changes its localization from the negatively charged impurity to the positively charged one as the distance between the impurities increases. The specifics of the atomic collapse in bilayer graphene is considered and it is shown that the atomic collapse in this material is not related to the phenomenon of the fall-to-center.
Features of spin dynamics in HgCrCdSe and HgCrSe crystals in the vicinity of phase transitions
Authors: Bekirov B. E. , Ivanchenko I. V. , Popenko N. A.
Published: May 2018

The inhomogeneously broadened EPR lines of the solid solutions Hg1–x–yCrxCdySe and Hg1–xCrxSe are represented in the form of spin packets and their temperature evolution is analyzed upon the transition of the crystals to ferromagnetic ordering. In this case, the spin packets being introduced into the consideration are identified with allowed transitions of the localized electrons and with the delocalized electrons. It is established that a characteristic feature of the subsystem of delocalized electrons is the anomalous behavior of the g-factor in the vicinity of the transition to the ferromagnetic state. The introduced spin subsystems, which characterize the localized and delocalized electronic states, allow for explaining the differences in scenarios of the transition to magnetic ordering of crystals with different cluster structures. Just significantly lower concentration of clusters in the HgCrSe crystal leads to a slowing down of flip-flop processes that explains the longer relaxation times of spin packets in this diluted magnetic semiconductor in comparison with the relaxation times of spin packets in the HgCrCdSe crystal in the ferromagnetic temperature range.
Pollution externalities point to fractal geometry in economics
Authors: Liebendorfer Adam
Published: May 2018

By adapting a standard economic growth model to account for pollution, and linearizing their findings on a logarthimic scale, researchers produced a Barnsley fern for economic steady states.
Gold as a catalyst. Part II. Alkynes in the reactions of carbon – carbon bond formation
Authors: Alyabyev Sergey B. , Beletskaya Irina P.
Published: May 2018

This publication continues the series of reviews devoted to the current state of gold catalysis in organic chemistry. The second review addresses Au-catalyzed reactions of alkynes, giving rise to carbon – carbon bonds. Most of the described reactions are addition reactions involving the triple bond of alkynes. The review covers both intramolecular reactions, including cyclization of various substrates (enynes, diynes, enediynes, etc.) and enyne isomerization without ring formation, and intermolecular reactions, including alkyne reactions with alkenes, other alkynes, heteroaromatic compounds, etc., in particular, tandem reactions. A special part is devoted to dual gold catalysis involving the intermediate formation of binuclear complexes with σ- and π-coordinated metal atoms. The last part of the review deals with the carbon – carbon bond formation reactions in which the alkyne triple bond is retained.

The bibliography includes 369 references.
Register variation in written contact varieties of English
Authors: Kruger Haidee , Rooy Bertus van
Published: May 2018

Previous research suggests there are register differences between native and non-native varieties of English, as well as translated English. This article reports on a multidimensional (MD) analysis of register variation in the published written registers of 16 varieties of English, and tests expectations for register variation in contact varieties evident from existing research. The study finds that the effects ofvarietyandregisterare largely independent of each other, indicating that overall, registers pattern in similar ways across varieties.registeris the strongest factor accounting for variance in the data, butvarietyalso contributes significantly to variation. Non-native varieties before phase four in the Dynamic Model (Schneider 2007) and translations draw more extensively on markers of formality than non-native varieties at phase four and native varieties. Contact varieties display fewer involvement features than native varieties. Persuasive strategies and reported speech are variable across varieties, suggesting local stylistic and cultural differences.
Epicene pronouns in intermediate to advanced EFL writing
Authors: Stormbom Charlotte
Published: May 2018

Since the second wave of feminism, non-sexist language use has become an increasingly important topic. A key issue in English is the choice of epicene pronouns, i.e. pronouns that refer to both sexes. Despite the global nature of English, little research has addressed this topic in EFL contexts. This study examines the use of the epicene pronounshe, he or she, andtheyin two L1 and L2 corpora of student writing. The corpus analyses show that, overall, the L2 English speakers usehesignificantly more than the L1 speakers, whereas the L1 speakers usetheymore. Variation found in the L2 subcorpora seems to be partly related to L1 influence: The writers who usehethe most are speakers of gendered L1s with a traditional practice of masculine generics. The study also shows that both L1 and L2 writers are affected by the antecedent type in their pronoun choice.
Does the passé composé influence L2 learners’ use of English past tenses?
Authors: Deshors Sandra C.
Published: May 2018

This study explores the uses of the present perfect (PP) and simple past (SP) by French learners of English and assesses how those uses differ from those in native English and those of the passé composé (PC) in native French which, semantically, overlaps with PP and SP. Methodologically, the study is based on over 3,000 contextualized occurrences of PP, SP and PC, and includes cluster and collostructional analyses. Overall, relatively native-like form-function mappings in interlanguage emerge from the analyses, suggesting that, semantically, advanced learners have integrated the uses of past tenses and that the influence of the PC is relatively weak. Further, at an upper-intermediate to advanced proficiency level, learners have integrated the fine-grained contextual information characteristic of the use of English past tenses. Ultimately, the study shows how different methodological designs can lead to varying conclusions on the (non-)nativelike usage patterns of PP in interlanguage.
Investigating L1 lay assessments of L2 French pronunciation
Authors: Lappin-Fortin Kerry
Published: May 2018

This study examined how 10 English Canadian students reading a 122-word passage in French were assessed by a diverse group of 40
native speaker lay listeners in France, thus addressing a lacuna in current pronunciation research. Both stimulus factors and
listener effects were investigated. Quantitative and qualitative data revealed strong correlations between perceptions of
accentedness and comprehensibility, and between lay ratings and those made by two experts. Results highlighted the impact phonemic
errors and rate of speech have on rater judgments, while linkings (liaisons) and other prosodic elements seemed to play a minor
role. Recommendations are made for a follow-up study using a larger sample.
Expressing i think that in Polish
Authors: Kokorniak Iwona , Jajko-Siwek Alicja
Published: May 2018

The paper investigates how four Polish mental predicates, signalling the subject’s of conception thinking process and representing the i think that conceptualisation, differ in usage and what motivates the difference. The verbs’ first person singular present tense forms, in an objective way, signal the speaker’s, i.e. the subject’s of conception, thoughts about the (ir)reality stored in their mind, whereas the content of clause complementation subjectively reveals the object of conception, namely the realm of one’s thoughts. A quantitative corpus-driven analysis implemented in the study presents how formal, semantic and extra-linguistic ‘usage features’ of the complementation interact with the verbs. The findings suggest that the i think that conceptualisation shows linguistic variation in Polish dependent on the temporal realm of the situation described in the complementation, the topic of discourse, and the evaluation of the event described.
An investigation of unaccusativity and word order in Mexican Spanish
Authors: Roggia Aaron B.
Published: May 2018

Studies of unaccusativity and word order in Spanish have yielded conflicting results. This study further investigates unaccusativity by testing the ability of the ‘Auxiliary Selection Hierarchy’ (Sorace 2000) to account for word orders with intransitive predicates in Mexican Spanish. The results of an oral production task show significant word order differences between verb categories and locate an unergative/unaccusative cutoff point midway along the hierarchy, situating unaccusativity in Spanish as being similar to Italian but trending in the direction of Dutch or French. Other variables affecting the word order are identified and ranked, including subject heaviness, definiteness, and the location of adverbial phrases. Greater inter-speaker variation at the syntax-discourse interface when compared with the syntax-lexicon interface shows that the Interface Hypothesis has application to native speakers of Spanish. The results of this study are important for current research on unaccusativity and syntactic interfaces.
Clinical sublanguages
Authors: Grön Leonie , Bertels Ann
Published: May 2018

Due to its specific linguistic properties, the language found in clinical records has been characterized as a distinct sublanguage. Even within the clinical domain, though, there are major differences in language use, which has led to more fine-grained distinctions based on medical fields and document types. However, previous work has mostly neglected the influence of term variation. By contrast, we propose to integrate the potential for term variation in the characterization of clinical sublanguages. By analyzing a corpus of clinical records, we show that the different sections of these records vary systematically with regard to their lexical, terminological and semantic composition, as well as their potential for term variation. These properties have implications for automatic term recognition, as they influence the performance of frequency-based term weighting.
High‐frequency resistance training does not promote greater muscular adaptations compared to low frequencies in young untrained men
Authors: Barcelos Cintia , Damas Felipe , Nóbrega Sanmy Rocha , Ugrinowitsch Carlos , Lixandrão Manoel Emílio , Marcelino Eder Dos Santos Lucas , Libardi Cleiton Augusto
Published: May 2018

The aim of the study was to compare the effect of resistance training (RT) frequencies of five times (RT5), thrice‐ (RT3) or twice‐ (RT2) weekly in muscle strength and hypertrophy in young men. Were used a within‐subjects design in which 20 participants had one leg randomly assigned to RT5 and the other to RT3 or to RT2. 1 RM and muscle cross‐sectional area (CSA) were assessed at baseline, after four (W4) and eight (W8) RT weeks. RT5 resulted in greater total training volume (TTV) than RT3 and RT2 (P = .001). 1 RM increased similarly between protocols at W4 (RT5: 55 ± 9 Kg, effect size (ES): 1.18; RT3: 51 ± 11 Kg, ES: 0.80; RT2: 54 ± 7 Kg, ES: 1.13; P < .0001) and W8 (RT5: 62 ± 11 Kg, ES: 1.81; RT3: 57 ± 11 Kg, ES: 1.40; RT2: 60 ± 8 Kg, ES: 1.98; P < .0001) vs. baseline (RT5: 45 ± 9 Kg; RT3: 42 ± 11 Kg; RT2: 46 ± 7 Kg). CSA increased similarly between protocols at W4 (RT5: 24.6 ± 3.9 cm2, ES: 0.54; RT3: 22.0 ± 4.6 cm2, ES: 0.19; RT2: ES: 0.25; 23.8 ± 3.8 cm2; P < .001), and W8 (RT5: 25.3 ± 4.3 cm2; ES: 0.69; RT3: 23.6 ± 4.2 cm2, ES: 0.58; RT2: 25.5 ± 3.7 cm2; ES: 0.70; P < .0001) vs. baseline (RT5: 22.5 ± 3.8 cm2; RT3: 21.2 ± 4.0 cm2; RT2: 22.9 ± 3.8 cm2). Performing RT5, RT3 and RT2 a week result in similar muscle strength increase and hypertrophy, despite higher TTV for RT5.
Enhanced response of global wetland methane emissions to the 2015–2016 El Niño-Southern Oscillation event
Authors: Zhang Zhen , Zimmermann Niklaus E , Calle Leonardo , Hurtt George , Chatterjee Abhishek , Poulter Benjamin
Published: May 2018

Wetlands are thought to be the major contributor to interannual variability in the growth rate of atmospheric methane (CH4) with anomalies driven by the influence of the El Niño-Southern Oscillation (ENSO). Yet it remains unclear whether (i) the increase in total global CH4 emissions during El Niño versus La Niña events is from wetlands and (ii) how large the contribution of wetland CH4 emissions is to the interannual variability of atmospheric CH4. We used a terrestrial ecosystem model that includes permafrost and wetland dynamics to estimate CH4 emissions, forced by three separate meteorological reanalyses and one gridded observational climate dataset, to simulate the spatio-temporal dynamics of wetland CH4 emissions from 1980–2016. The simulations show that while wetland CH4 responds with negative annual anomalies during the El Niño events, the instantaneous growth rate of wetland CH4 emissions exhibits complex phase dynamics. We find that wetland CH4 instantaneous growth rates were declined at the onset of the 2015–2016 El Niño event but then increased to a record-high at later stages of the El Niño event (January through May 2016). We also find evidence for a step increase of CH4 emissions by 7.8±1.6 Tg CH4 yr−1 during 2007–2014 compared to the average of 2000–2006 from simulations using meteorological reanalyses, which is equivalent to a ~3.5 ppb yr−1 rise in CH4 concentrations. The step increase is mainly caused by the expansion of wetland area in the tropics (30°S–30°N) due to an enhancement of tropical precipitation as indicated by the suite of the meteorological reanalyses. Our study highlights the role of wetlands, and the complex temporal phasing with ENSO, in driving the variability and trends of atmospheric CH4 concentrations. In addition, the need to account for uncertainty in meteorological forcings is highlighted in addressing the interannual variability and decadal-scale trends of wetland CH4 fluxes.
Almost sure invariance principle for non-autonomous holomorphic dynamics in ℙ^{𝕜}
Authors: Bayraktar Turgay
Published: May 2018

We prove an almost sure invariance principle, a strong form of approximation by Brownian motion, for non-autonomous holomorphic dynamical systems on complex projective space

P

k

\mathbb {P}^k

for Hölder continuous and DSH observables.
The Rényi divergence enables accurate and precise cluster analysis for localization microscopy
Authors: Staszowska Adela D , Fox-Roberts Patrick , Hirvonen Liisa M , Peddie Christopher J , Collinson Lucy M , Jones Gareth E , Cox Susan
Published: May 2018

Motivation

Clustering analysis is a key technique for quantitatively characterizing structures in localization microscopy images. To build up accurate information about biological structures, it is critical that the quantification is both accurate (close to the ground truth) and precise (has small scatter and is reproducible).

Results

Here, we describe how the Rényi divergence can be used for cluster radius measurements in localization microscopy data. We demonstrate that the Rényi divergence can operate with high levels of background and provides results which are more accurate than Ripley’s functions, Voronoi tesselation or DBSCAN.

Availability and implementation

The data supporting this research and the software described are accessible at the following site: https://dx.doi.org/10.18742/RDM01-316. Correspondence and requests for materials should be addressed to the corresponding author.

Supplementary information

Supplementary data are available at Bioinformatics online.
Improved design and analysis of CRISPR knockout screens
Authors: Chen Chen-Hao , Xiao Tengfei , Xu Han , Jiang Peng , Meyer Clifford A , Li Wei , Brown Myles , Liu X Shirley
Published: May 2018

Motivation

Genome-wide clustered, regularly interspaced, short palindromic repeat (CRISPR)-Cas9 screen has been widely used to interrogate gene functions. However, the rules to design better libraries beg further refinement.

Results

We found single guide RNA (sgRNA) outliers are characterized by higher G-nucleotide counts, especially in regions distal from the PAM motif and are associated with stronger off-target activities. Furthermore, using non-targeting sgRNAs as negative controls lead to strong bias, which can be mitigated by using sgRNAs targeting multiple ‘safe harbor’ regions. Custom-designed screens confirmed our findings and further revealed that 19 nt sgRNAs consistently gave the best signal-to-noise ratio. Collectively, our analysis motivated the design of a new genome-wide CRISPR/Cas9 screen library and uncovered some intriguing properties of the CRISPR-Cas9 system.

Availability and implementation

The MAGeCK workflow is available open source at https://bitbucket.org/liulab/mageck_nest under the MIT license.

Supplementary information

Supplementary data are available at Bioinformatics online.
Risk Factors for Self-Reported Cholera Within HIV-Affected Households in Rural Haiti
Authors: Richterman Aaron , Cheung Hoi Ching , Meiselbach Mark K , Jerome Gregory , Ternier Ralph , Ivers Louise C
Published: May 2018

Background

Cholera continues to be a major cause of morbidity and mortality worldwide and is now endemic in Haiti since first being introduced in 2010. Cholera and HIV have significant geographic overlap globally, but little is known about the clinical features and risk of cholera among HIV-infected people and their households.

Methods

We assessed HIV-affected households originally recruited for a randomized controlled trial of food supplements. We assessed for correlation between household and individual factors and reported history of cholera since 2010 using univariable and multivariable analyses.

Results

There were 352 HIV-infected household members, 32 with reported history of medically attended cholera, and 1968 other household members, 55 with reported history of medically attended cholera. Among HIV-infected individuals in this study, no variables correlated with reported history of cholera in univariable analyses. Among all household members, known HIV infection (adjusted odds ratio [AOR], 3.75; 95% CI, 2.43–5.79; P < .0001), source of income in the household (AOR, 1.82; 95% CI, 1.05–3.15; P = .034), time required to fetch water (AOR, 1.07 per 5-minute increase; 95% CI, 1.01–1.12; P = .015), and severe household food insecurity (AOR, 3.23; 95% CI, 1.25–8.34; P = .016) were correlated with reported history of cholera in a multivariable analysis.

Conclusions

Known HIV infection, source of household income, time required to fetch water, and severe household food insecurity were independently associated with reported history of medically attended cholera in HIV-affected households in rural Haiti. Further research is required to better understand the interactions between HIV and cholera.
Optimizing Pedicle Subtraction Osteotomy Techniques: A New Reduction Plier to Increase Technical Safety and Angular Reduction Efficiency
Authors: Faundez Antonio , Le Huec Jean-Charles , Hansen Lars V , Poh Ling Fong , Gehrchen Martin
Published: May 2018

BACKGROUND

Pedicle subtraction osteotomy (PSO) is a technically demanding surgery. There is room for development of osteotomy reduction instruments like the one we present in this study, to better guide angular correction and closure of the osteotomy line.

OBJECTIVE

To present a new surgical instrument that optimizes PSOs of the thoracolumbar spine.

METHODS

Seventeen consecutive patients have been treated at 3 different European University Hospitals. All underwent a PSO of the lumbar spine to treat major sagittal imbalance. The amount of vertebral angular correction needed was calculated using the full balance integrated (FBI) method. A special plier, which allows to safely control the angular correction, was used intraoperatively. Preoperative and early postoperative global sagittal balance parameters were compared.

RESULTS

The mean preoperative calculated correction angle (FBI) was 33.8°; the mean postoperative correction obtained was 32.1°. Lumbar lordosis was statistically greater than preoperatively (55.8° vs 19.4°, P < .0001). The global sagittal balance was improved, as shown by the increase of the spino-sacral angle from 122° preoperatively to 128° postoperatively (P = .0547). None of the patients had an intraoperative or early postoperative neurologic complication. There were no mechanical intraoperative complications during correction nor at the first postoperative follow-up.

CONCLUSION

The advantages of the instrument are safe, precise, and efficient reduction, by a rotation of the pedicle screws close to the osteotomy line, thus avoiding collapse and lack of correction, complications usually seen with the conventional technique. Further prospective studies are needed to confirm these results.
First photometric analysis of magnetic activity and orbital period variations for the semi-detached binary BU Vulpeculae
Authors: Wang Jingjing , Zhang Bin , Yu Jing , Liu Liang , Tian Xiaoman
Published: May 2018

Four sets of multi-color CCD photometric observations of the close binary BU Vul were carried out for four successive months in 2010. From our observations, there are obvious variations and asymmetry of light curves on the timescale of a month, indicating high-level stellar spot activity on the surface of at least one component. The Wilson–Devinney (2010) program was used to determine the photometric solutions, which suggest that BU Vul is a semi-detached binary with the cool, less massive component filling with the critical Roche lobe. The solutions also reveal that the spots on the primary and the secondary have changed and drifted in 2010 July, August, and September. Based on analysis of the O − C curves of BU Vul, its orbital period shows a cyclic oscillation (T3 = 22.4 yr, A3 = 0.0029 d) superimposed on a secular increase. The continuous increase is possibly a result of mass transfer from the less massive component to the more massive one at a rate of dM/dt = −2.95 × 10−9 M⊙ yr−1. The cyclic variation maybe be caused by the presence of a tertiary companion with extremely low luminosity. Combined with the distortions of the light curve on 2009 November 4, we infer that BU Vul has two additional companions in a quadruple system.
Pediatric Abdominal Emergency Imaging for the Adult-Focused Diagnostic Radiologist
Authors: Majmudar Anand , Teague Clint
Published: May 2018

Clinical symptoms such as nausea, vomiting, and abdominal pain are the common reasons for which pediatric patients visit the emergency department. Because the clinical presentation can be confusing in children, imaging plays a major role in establishing differential diagnoses. The objective of this article is to review pediatric abdominal conditions that the adult-focused diagnostic radiologist may encounter when covering the emergency department. We address the commonly encountered pediatric abdominal and pelvic emergencies, with emphasis on the imaging findings in conditions such as midgut volvulus, intussusception, foreign body ingestion, acute appendicitis, hypertrophic pyloric stenosis, testicular torsion, and ovarian torsion. Treatment and associated complications also have been mentioned, but the main focus remains on imaging.
Flibanserin for hypoactive sexual desire disorder in premenopausal women
Authors: Clements Jennifer N. , Thompson Brittany
Published: May 2018

Flibanserin is a mixed 5-HT1A agonist and 5-HT2A antagonist for treatment of premenopausal women with hypoactive sexual desire disorder. It is the first FDA-approved treatment for this disorder and can improve the number of satisfying sexual events. The drug has been associated with hypotension and syncope.
PAs reduce rounding interruptions in the pediatric intensive care unit
Authors: Hascall Rebecca L. , Perkins R. Serene , Kmiecik Lauren , Gupta Priya R. , Shelak Carolyn F. , Demirel Shaban , Buchholz Mark T.
Published: May 2018

Objective:

We investigated the proportion of encounters that were interrupted during family-centered rounds in the pediatric intensive care unit (PICU) to determine whether the use of a physician assistant (PA) significantly affected the proportion of interrupted encounters.

Methods:

We evaluated 2,657 rounding encounters in our 24-bed regional referral unit. The duration of each rounding encounter and total rounding duration were recorded. The presence or absence of a PA during each rounding encounter, the occurrence of an interruption, and other potential predictors of interruptions were recorded.

Results:

The presence of a PA during PICU rounds was significantly associated (P < .001) with a 35.4% lower likelihood of an interruption.

Conclusions:

Family-centered rounds in the PICU are less likely to be interrupted when a PA is present. PAs help physicians and improve rounding efficiency by safely and effectively handling certain interruptions.
Psychometric Evaluation of the Mock Code Self-Efficacy Scale
Authors: Oetker-Black Sharon L. , Davis Tammie
Published: May 2018

AIM

This study's purpose is to psychometrically evaluate the Mock Code Self-Efficacy Scale. This tool was developed to measure senior baccalaureate nursing students' level of self-efficacy as it pertains to mock codes.

BACKGROUND

Cardiopulmonary resuscitation is an essential component of nursing education.

METHOD

The Mock Code Self-Efficacy Scale was analyzed for item characteristics, face validity, content validity, reliability, and dimensionality in a sample of senior-level nursing students (n = 153) enrolled in a critical care nursing course.

RESULTS

The scale was found to be multidimensional with reliabilities ranging from .75 to .87. Items evidenced a ceiling effect, perhaps due to the instruction given prior to completing the instrument. The instrument evidenced both content and face validity.

CONCLUSION

The instrument now can be used to assess if increased self-efficacy is a mediating variable for students to correctly transfer skills learned in a mock code to the clinical setting.
Hemodynamic Management of Patients During Endovascular Treatment of Acute Ischemic Stroke Under Conscious Sedation: A Retrospective Cohort Study
Authors: Alcaraz Gabriela , Chui Jason , Schaafsma Joanna , Manninen Pirjo , Porta-Sánchez Andreu , Pereira Vitor Mendes , Venkatraghavan Lashmi
Published: May 2018

Background:

Anesthetic modality and hemodynamic management during mechanical thrombectomy (MT) for acute ischemic stroke (AIS) are potential contributors to the success of revascularization. The aims of our study were to review the hemodynamic management by anesthesiologists and clinical outcomes in patients undergoing MT under conscious sedation.

Methods:

Retrospective cohort study of patients with anterior circulation AIS from January 2012 to March 2016. Primary outcome was hemodynamic intervention, defined as administration of vasoactive drugs to maintain systolic blood pressure (BP) between 140 and 180 mm Hg. The secondary outcome was poor hemodynamic control, defined as BP outside target for >15 minutes despite hemodynamic intervention. We performed regression analysis to determine the predictors of hemodynamic intervention and poor hemodynamic control.

Results:

A total of 126 patients were included in this study; 92% (116) receiving conscious sedation and 8% (10) no sedation. Upon arrival to the neuroradiology suite, systolic BP was <140 mm Hg in 30.2% of the patients and >180 mm Hg in 14.3%. Hemodynamic intervention was required in 38.9% of patients; 15.1% for hypotension and 19.8% for hypertension. In the multivariate analysis, systolic BP on hospital admission (odds ratio, 1.02; 95% confidence interval, 1.00-1.04; P=0.019) constituted a predictor for hemodynamic intervention. Poor hemodynamic control occurred in 12.7% of patients, with lower baseline systolic BP being associated with higher risk of intraprocedural hypotension (odds ratio, 0.92; 95% confidence interval, 0.89-0.96; P<0.001). In-hospital mortality was 13.6%.

Conclusions:

Hemodynamic intervention is frequent during MT under conscious sedation. The routine presence of anesthesiologists during MT may be helpful in maintaining hemodynamic stability and allow rapid treatment of emergent complications. An individualized approach with tailored hemodynamic targets is required during management of patients undergoing MT for AIS.
Open Reduction and Internal Fixation for the Treatment of Symptomatic Osteochondritis Dissecans of the Femoral Head in Patients With Sequelae of Legg-Calvé-Perthes Disease
Authors: Lamplot Joseph D. , Schoenecker Perry L. , Pascual-Garrido Cecilia , Nepple Jeffery J. , Clohisy John C.
Published: May 2018

Background:

Osteochondritis dissecans (OCD) is estimated to occur in 2% to 7% of patients with Legg-Calvé-Perthes disease (LCPD). Unstable osteochondral fragments secondary to LCPD may produce mechanical symptoms requiring surgical intervention. Reattachment of the fragment with open reduction and internal fixation (ORIF) may provide good clinical outcomes. The purpose of this study is to report short-term clinical and radiographic results of ORIF for the treatment of symptomatic osteochondral lesions resulting from LCPD.

Methods:

Clinical data including patient demographics and patient-reported outcome scores were collected prospectively. All patients underwent preoperative radiographs and magnetic resonance imaging confirming an unstable OCD fragment as well as postoperative radiographs at regular intervals. Indications for ORIF of the OCD fragment were hip pain and mechanical symptoms with radiographic evidence of LCPD and a magnetic resonance imaging demonstrating an OCD fragment of the femoral head. Osteochondral fragment instability was confirmed intraoperatively. Preoperative and postoperative physical examination findings were documented. All patients failed a course of nonsurgical treatment (activity modification, anti-inflammatories, and physical therapy).

Results:

From a total of 64 consecutive patients treated with hip preservation surgery for LCPD, 7 patients with symptomatic OCD secondary to LCPD were treated with surgical hip dislocation and ORIF of the femoral head osteochondral fragment. OCD size lesion ranged from 200 to 625 mm2. All patients reported marked clinical improvement, with resolution of both pain and mechanical symptoms. Radiographs at final follow-up demonstrated complete osteochondral fragment healing without implant failure. Mean follow-up was 4.6 years (range, 1.1 to 7.4 y). There was a significant postoperative improvement in measured internal rotation in flexion (5.0±5.0 to 16.4±9.8; P=0.02). Modified Harris Hip Score markedly improved from baseline to final follow-up (47.8 to 82.7; ∆34.9; minimal clinically important difference, 11; P=0.002), with all patients meeting minimal clinically important difference for modified Harris Hip Score. There were no complications and no progression of osteoarthritis in all patients at final follow-up.

Conclusions:

We have demonstrated both predictable radiographic healing and marked clinical improvement following ORIF of symptomatic post-Perthes OCD lesions. We advocate ORIF for symptomatic osteochondral lesions as a first-line surgical treatment for these patients due to the advantages of native osteochondral tissue preservation, predictable healing, and marked clinical improvement.

Level of Evidence:

Level IV—case series.
Endplate Defect Is Heritable, Associated With Low Back Pain and Triggers Intervertebral Disc Degeneration
Authors: Munir Sabrina , Freidin Maxim B. , Rade Marinko , Määttä Juhani , Livshits Gregory , Williams Frances M.K.
Published: May 2018

Study Design.

Longitudinal study of spine magnetic resonance imaging (MRI) in a large-scale population-based study.

Objective.

To determine the order of appearance of degenerative change in vertebral bodies and intervertebral discs. We also sought to define the influence of endplate defect on low back pain (LBP) and to determine whether there is a genetic influence on endplate defect.

Summary of Background Data.

Endplate defect is a magnetic resonance imaging trait, found to be associated with intervertebral disc degeneration. There is a lack of understanding regarding the mechanism underlying lumbar disc degeneration (LDD). Recent attention has shifted to vertebral endplate defects and their role in spine degeneration pathology.

Methods.

Individuals from the TwinsUK spine study having longitudinal T2-weighted lumbar MR scans at baseline (n = 996) and a decade later (n = 438) were included. LDD, vertebral endplate defect by calculating a total endplate score, and Modic change (MC) were assessed using standard techniques. Mixed-effects models were used to determine the association between the features of spine pathology, adjusted for covariates. Endplate defect heritability was estimated using variance component analysis.

Results.

Significant association was found between endplate defect, LDD, MRI features of LDD and MC was observed. Endplate defect was associated with severe disabling LBP (P ≤ 0.013) in multivariate analysis. An association between disc degeneration (DD) at baseline and MC at follow-up was shown at upper lumbar levels. Total endplate score was heritable with estimated additive genetic component A = 55.3% (95% CI 43.0–65.4).

Conclusion.

Endplate defect, LDD, and MC are all independent risk factors for episodes of severe and disabling LBP. Longitudinal analysis showed DD is followed by MC. Endplate defect has significant heritability of 55%. However, whether endplate defect triggers DD or these pathological changes occur concurrently could not be conclusively determined.

Level of Evidence: 2
Are Patients Undergoing an Anterior Cervical Discectomy and Fusion Treated Differently at a Physician-owned Hospital?
Authors: Schroeder Gregory D. , Kurd Mark F. , Kepler Christopher K. , Radcliff Kris E. , Maltenfort Mitchell G. , Murphy Hamadi , Rihn Jeffery A. , Anderson D. Greg , Hilibrand Alan S. , Vaccaro Alexander R.
Published: May 2018

Study Design:

Retrospective case-control study.

Background:

Physician-owned specialty hospitals focus on taking care of patients with a select group of conditions. In some instances, they may also create a potential conflict of interest for the surgeon. The effect this has on the surgical algorithm for patients with degenerative cervical spine conditions has not been determined.

Methods:

A retrospective review of all patients who underwent a 1- or 2-level anterior cervical discectomy and fusion between October 2009 and December 2014 at either a physician-owned specialty hospital or an independently owned community hospital were identified. Demographic information, the time course for treatment and the nonoperative treatment regimen were evaluated.

Results:

In total, 115 patients undergoing surgery at a physician-owned specialty hospital and 149 patients undergoing surgery at an independent community hospital were identified. Demographic data between the groups including the presence of 12 medical comorbidities and insurance status was similar between the groups. The only difference that was identified was that patients at the surgeon-owned hospital were marginally younger than patients who had surgery at the independent hospital (49.7 vs. 50.0, P=0.048). No difference in the median number of months from the onset of symptoms to surgery (6.51 vs. 7.53 mo, respectively; P=0.55), from the onset of symptoms to the preoperative visit (6.02 vs. 6.02, P=0.64), or from the initial surgical consultation to surgery (0.99 vs. 1.02, P=0.31) was identified. No difference in the number of patients who underwent formal physical therapy (72.2% vs. 67.1%, P=0.42) or who had a cervical steroid injection (55.6% vs. 50.3%, P=0.25%) was identified between patients who had surgery at a physician-owned or independent hospital; however, patients who underwent surgery at the physician-owned hospital were more likely to have taken oral anti-inflammatories (93.0% vs. 83.9%, P=0.04).

Conclusions:

When comparing hospitals with similar resources, surgeons do not preferentially select younger, healthier patients with higher paying insurance to be treated at the physician-owned hospital. Furthermore, both the time from the onset of symptoms to surgery and the nonoperative treatment regimen were similar between patients treated at the 2 facilities.
Ankle Fractures in Diabetic Patients
Authors: Aminian Arash , Heinen Angela
Published: May 2018

Unstable ankle fractures in patients with complicated diabetes are an orthopedic challenge. Internal fixation, with augmentation, and prolonged immobilization and non–weight-bearing are important for improved patient outcomes. Despite the risks associated with surgical intervention, nonoperative treatment has been associated with significantly increased complications compared with operative treatment in diabetic patients with unstable ankle fractures.

Level of Evidence: Diagnostic Level IV. See Instructions for Authors for a complete description of levels of evidence.
Safe Patient Handling and Mobility
Authors: Lee Corinne , Knight Suzanne W. , Smith Sharon L. , Nagle Dorothy J. , DeVries Lori
Published: May 2018

This article addresses the development, implementation, and evaluation of an education program for safe patient handling and mobility at a large academic medical center. The ultimate goal of the program was to increase safety during patient mobility/transfer and reduce nursing staff injury from lifting/pulling. This comprehensive program was designed on the basis of the principles of prework, application, and support at the point of care. A combination of online learning, demonstration, skill evaluation, and coaching at the point of care was used to achieve the goal. Specific roles and responsibilities were developed to facilitate implementation. It took 17 master trainers, 88 certified trainers, 176 unit-based trainers, and 98 coaches to put 3706 nurses and nursing assistants through the program. Evaluations indicated both an increase in knowledge about safe patient handling and an increased ability to safely mobilize patients. The challenge now is sustainability of safe patient-handling practices and the growth and development of trainers and coaches.
Development of Medical Criteria for Mobilizing a Pediatric Patient in the PICU
Authors: Van Damme Danielle , Flori Heidi , Owens Tonie
Published: May 2018

Physical activity in acute and critical care has been recognized as a successful method of improving patient outcomes. Challenges lie, however, in mobilizing pediatric critically ill patients and establishing consensus among health care providers about the safety and feasibility. The challenge of mobilizing pediatric patients is balancing developmental level, functional ability, and level of acuity; therefore, a mobility guideline was developed for use in the pediatric intensive care unit (PICU). The unique population and challenges in the PICU led to the development of a PICU-specific set of medical criteria within a PICU mobility guideline. The process of determining the medical criteria, using evidence, is discussed along with stratification of the criteria into phases of mobility. We review the criteria and the implications for mobility guidelines and patient outcomes.