bluuebunny/crossref_metadata_2025 huggingface dataset:
A Practical Single‐Channel Algorithm for Land Surface Temperature Retrieval: Application to Landsat Series Data
Authors: Wang Mengmeng , Zhang Zhengjia , Hu Tian , Liu Xiuguo
Published: December 2018

The single‐channel (SC) algorithm has been widely used to retrieve land surface temperature from Landsat series data for its simplicity and requirement of only one thermal infrared channel. The main error sources of the existing SC algorithms are the linearization of the Planck's function and atmospheric correction. This paper proposed a practical SC (PSC) algorithm to retrieve land surface temperature from Landsat series data aiming at avoiding the aforementioned error sources. The sensitivity of the PSC algorithm to the input parameters was analyzed. The performance of the proposed PSC algorithm was compared with the most commonly used SC algorithm (the generalized SC, GSC) using a simulation data set and satellite measurements. Results showed that the PSC algorithm was less sensitive to uncertainties in the input parameters than the GSC algorithm. When validated with the simulation data set, the root‐mean‐square error (RMSE) of the PSC algorithm was 1.23 K, with an improvement by 0.57 K compared with the GSC algorithm. For the validation with 71 clear‐sky Landsat 8 images, the RMSE of the PSC algorithm was 1.77 K when using the measurements from U.S. surface radiation budget network as real values. Compared with the GSC algorithm, the RMSE improvement for the PSC algorithm was 0.47 K. We conclude that the PSC algorithm is more accurate than the GSC algorithm and the sensitivity to input parameters in the PSC algorithm is weaker than in the GSC algorithm.
Mesospheric Temperature During the Extreme Midlatitude Noctilucent Cloud Event on 18/19 July 2016
Authors: Kaifler N. , Kaifler B. , Wilms H. , Rapp M. , Stober G. , Jacobi C.
Published: December 2018

A rare noctilucent cloud (NLC) event was observed at 48.8∘ N, 13.7∘ E above GERman Experimental Seismic System station in southern Germany on 18/19 July 2016 using the Compact Rayleigh Autonomous Lidar. Strong southward winds due to a quasi 2‐day planetary wave allowed for the influx of mesospheric polar air to midlatitudes on this day. The NLC observed by lidar was preceded by strong NLC displays in Cloud Imaging and Particle Size (CIPS) Experiment satellite images above the North Sea and by strong mesospheric summer radar echoes 800 km north of the lidar site and was also observed visually in central Europe. The NLC occurred at low altitude and was bright and thin with strong oscillations in altitude and brightness. Darkness allowed for high‐resolution temperature measurements at NLC altitudes. The ice particles were embedded in the upper part of a cold region with temperatures below 150 K. Significantly higher temperatures were found directly above the cloud with large vertical temperature gradients of 25 K/km at the top boundary. Spectral analysis reveals that NLC particles existed within cold phases of gravity waves within a region of high static stability. In order to study the evolution of NLC brightness in this environment, we drive the microphysical model Community Aerosol and Radiation Model for Atmospheres with lidar temperature soundings. We find that NLC particles can survive and grow in the conditions defining this midlatitude event. We conclude that the ice particles did not nucleate at the site of observation but were meridionally transported and vertically confined to a thin layer due to a large vertical temperature gradient, wind reversal, and low levels of mesospheric turbulence.
The Importance of Capturing Topographic Features for Modeling Groundwater Flow and Transport in Mountainous Watersheds
Authors: Wang Chao , Gomez‐Velez Jesus D. , Wilson John L.
Published: December 2018

Physics‐based distributed hydrological models that include groundwater are widely used to understand and predict physical and biogeochemical processes within watersheds. Typically, due to computational limitations, watershed modelers minimize the number of elements used in domain discretization, smoothing or even ignoring critical topographic features. We use an idealized model to investigate the implications of mesh refinement along streams and ridges for modeling three‐dimensional groundwater flow and transport in mountainous watersheds. For varying degrees of topographic complexity level (TCL), which increases with the level of mesh refinement, and geological heterogeneity, we estimate and compare steady state baseflow discharge, mean age, and concentration of subsurface weathering products. Results show that ignoring lower‐order streams or ridges diminishes flow through local flow paths and biases higher the contribution of intermediate and regional flow paths, and biases baseflow older. The magnitude of the bias increases for systems where permeability rapidly decreases with depth and is dominated by shallow flow paths. Based on a simple geochemical model, the concentration of weathering products is less sensitive to the TCL, partially due to the thermodynamic constraints on chemical reactions. Our idealized model also reproduces the observed emergent scaling relationship between the groundwater contribution to streamflow and drainage area, and finds that this scaling relationship is not sensitive to mesh TCL. The bias effects have important implications for the use of hydrological models in the interpretation of environmental tracer data and the prediction of biogeochemical evolution of stream water in mountainous watersheds.
Velocities, Residence Times, Tracer Breakthroughs in a Vegetated Lysimeter: A Multitracer Experiment
Authors: Benettin Paolo , Queloz Pierre , Bensimon Michaël , McDonnell Jeffrey J. , Rinaldo Andrea
Published: December 2018

Flow velocities, residence times, and tracer breakthroughs at the lysimeter scale are affected by matrix properties and preferential flow. Despite their relevance to transport processes, however, the relative timing of preferential flow, and its link to transit times through the soil block, is still poorly described. Here we present and analyze tracer data from a 2.5 m3 vegetated lysimeter experiment where 18 mm of isotopically labeled water was added as a pulse and then followed with a series of tracer‐free controlled rainfall events for 5 months. A solution of two fluorobenzoid acid tracers was also injected and tracked. Time series of soil water samples at three different depths and bottom drainage samples were collected and analyzed. Unlike past lysimeter experiments, a willow tree grown within the lysimeter exerted strong evapotranspiration fluxes. By comparative analysis of soil water and bottom drainage samples, we show the presence of both translatory and preferential flow features reflecting the interplay of slow vertical percolation and fast recharge through macropores. We found that water ponding and evaporating from the top of the lysimeter after irrigation prompted samples to be highly and irregularly fractionated. Comparative analyses of multitracer breakthroughs (adjusted by removing fractionation effects) showed that fluorobenzoid acid tracers reached the bottom of the lysimeter earlier than the isotopes, likely due to the effect of plant uptake. Our results underscore the essential role of models to interpret tracer behavior and, critically, the importance of future experiments aimed at measuring the ages of the water abstracted by vegetation.
Boron-doped diamond: current progress and challenges in view of electroanalytical applications
Authors: Muzyka Kateryna , Sun Jianrui , Fereja Tadesse Haile , Lan Yixiang , Zhang Wei , Xu Guobao
Published: December 2018

This review examines the current status (from 2016 to December 2018) of the electroanalytical application of boron-doped diamond (BDD), in view of its advantages and challenges for electroanalytical applications.
Position- and region-isomerized derivatives of a V-shaped fluorophore: the unique solution-state dual emission and the unusual force-induced solid-state turn-on emission
Authors: Fu Hong-Yu , Liu Xiao-Jing , Zha Hao , Li Xiao-Xue , Xu Yi , Yang Fan , Xia Min
Published: December 2018

The dual emission in solution and force-induced turn-on emission in solid state are observed on the region and position isomers of a V-shaped fluorophore.
Glucose oxidation performance is improved by the use of a supramolecular self-assembly of glucose oxidase and catalase
Authors: Cui Caixia , Fang Yunming , Chen Biqiang , Tan Tianwei
Published: December 2018

A multi-enzymes complex was assembled successfully via host/guest interactions, and it was used for rapid transformation of glucose.
One‐step leapfrog WCS‐FDTD for drude dispersive models
Authors: Gao Jian‐Yun , Wang Xiang‐Hua , Teixeira Fernando L.
Published: December 2018

A one‐step leapfrog weakly conditionally stable finite‐difference time‐domain method for modelling drude dispersive models is developed. Numerical results show that its stability condition remains invariant with respect to that in lossless media. The new algorithm is applied to efficiently investigate the transmission properties of a graphene sheet and a graphene‐based frequency selective surface.
Lowering mutual coherence between receptive fields in convolutional neural networks
Authors: Amini S. , Ghaemmaghami S.
Published: December 2018

It has been shown that more accurate signal recovery can be achieved with low‐coherence dictionaries in sparse signal processing. In this Letter, the authors extend the low‐coherence attribute to receptive fields in convolutional neural networks. A new constrained formulation to train low‐coherence convolutional neural network is presented and an efficient algorithm is proposed to train the network. The resulting formulation produces a direct link between the receptive fields of a layer through training procedure that can be used to extract more informative representations from the subsequent layers. Simulation results over three benchmark datasets confirm superiority of the proposed low‐coherence convolutional neural network over the unconstrained version.
Outage probability of fixed‐gain amplify‐and‐forward two‐way relays with multiple co‐channel interferers
Authors: Mandpura Anup , Prakriya Shankar , Mallik Ranjan K.
Published: December 2018

In this study, the authors consider a two‐way relaying (TWR) system with source terminals and and a relay terminal . They analyse the performance of a fixed‐gain amplify‐and‐forward‐based TWR system over Rayleigh fading channels with co‐channel interference at all the terminals. Expressions are derived for the outage probability of the system at a medium‐to‐high signal‐to‐interference‐plus‐noise ratio (SINR) range. They also obtain the expression for the value of outage floor and use this to optimise relay location and power allocation. Simulation results demonstrate accuracy of the derived expressions in different SINR ranges.
Compressed channel estimation for FDD massive MIMO systems without prior knowledge of sparse channel model
Authors: Azizipour Mohammad Javad , Mohamed‐Pour Kamal
Published: December 2018

In this study, a new greedy‐based algorithm for sparse channel estimation in frequency‐division duplexing massive multiple‐input multiple‐output (MIMO) systems is introduced. The proposed algorithm is able to acquire the channel with no information about the channel model such as the sparsity order, statistical bound on sparsity support, and special features of the channel. In other words, the authors assume that the massive channel is totally unknown and then exploit the inherent property of correlation between measurements and the sensing matrix to estimate the channel, which is available at the user side. By utilising this property, a halting parameter is defined as the halting threshold instead of known prior information assumed in the conventional greedy algorithms. Furthermore, the lower and upper bounds of the halting parameter are obtained that helps the algorithm to take the suitable values of this parameter and by considering the lower bound as the values of the halting parameter, the algorithm can prevent from missing the original channel bins. Simulation results demonstrate that the proposed algorithm outperforms its counterparts in terms of normalised mean square error while it faces a completely unknown massive MIMO channel.
Pilot decontamination in massive multiuser MIMO systems based on low‐rank matrix approximation
Authors: Hawej Muamer , Shayan Yousef R.
Published: December 2018

In multi‐cell massive multiuser multi‐input multi‐output (MU‐MIMO) systems, the channel estimation performance is degraded by the pilot contamination problem. This effect occurs when non‐orthogonal pilot sequences are reused by other users in the adjacent cells. In this study, two channel estimation methods based on low‐rank matrix approximation technique are proposed to mitigate pilot contamination problem in time division duplex multi‐cell massive MU‐MIMO systems. In the first method, the massive MU‐MIMO channel estimation is formulated as the nuclear norm (NN) optimisation problem and solved by using a novel estimation algorithm proposed in this study. In the second method, the iterative weighted NN (IWNN) is proposed to improve the NN estimation performance. Consequently, the regularisation parameter of both optimisation methods is selected based on the cross‐validation curve method. The simulation results show that both proposed methods outperform the traditional least square method in terms of the normalised mean square error. Moreover, the IWNN estimation method demonstrates substantial improvement over the NN estimation method in the presence of strong pilot contamination problem.
Adaptive convolutional layer selection based on historical retrospect for visual tracking
Authors: Tang Fuhui , Lu Xiankai , Zhang Xiaoyu , Luo Lingkun , Hu Shiqiang , Zhang Huanlong
Published: December 2018

Visual tracking has recently gained a great advance with the use of the convolutional neural network (CNN). Usually, existing CNN‐based trackers exploit the features from a single layer or a certain combination of multiple layers. However, these features only characterise an object from an invariable aspect and cannot adapt to scene variation, which limits the performance of such trackers. To overcome this limitation, the authors study the problem from a new perspective and propose a novel convolutional layer selection method. To obtain robust appearance representation, they investigate the advantages of features extracted from different convolutional layers. To determine the correctness of the tracking prediction and updated model, they design a verification mechanism based on historical retrospect, which can estimate the deviation for each layer by bidirectionally locating the target. Meanwhile, the deviation works as the layer‐wise selection criteria. Extensive evaluations on the OTB‐2013, visual object tracking (VOT)‐2016 and VOT‐2017 benchmarks demonstrate that the proposed tracker performs favourably against several state‐of‐the‐art trackers.
Tubular unified magnetic‐field flux‐switching PMLM for free‐piston energy converter
Authors: Sui Yi , Zheng Ping , Liu Yong , Wang Mingqiao , Yin Zuosheng
Published: December 2018

A tubular flux‐switching permanent‐magnet linear machine (PMLM), which features unified magnetic field between the mover and two stators, is investigated for free‐piston energy converter. The topology evolution, topology, operating principle and design considerations of the machine are thoroughly analysed. With the sinusoidal speed characteristic of free‐piston Stirling engine considered, a tubular unified magnetic‐field flux‐switching PMLM is designed by finite‐element analysis. Several main structural parameters, which include the outer and inner radius of the mover, the mover tooth width, the magnet thickness, the tooth widths of both the outer and inner stators and the widths of both the outer and inner stator yokes are studied to achieve high‐force and mass‐power density. Finally, the proposed machine is compared with two typical flux‐switching PMLMs. The comparison results show that the unified magnetic‐field flux‐switching PMLM is suitable for applications which require high‐power density, light mover structure and fast dynamic.
Automatic segmentation of MR depicted carotid arterial boundary based on local priors and constrained global optimisation
Authors: Zhang Jianhua , Teng Zhongzhao , Guan Qiu , He Junli , Abutaleb Wafa , Patterson Andrew J. , Graves Martin J. , Gillard Jonathan , Chen Shengyong
Published: December 2018

Segmentation of lumen (LB) and outer wall boundaries (OB) of carotid artery in magnetic resonance (MR) images is essential for carotid atherosclerotic disease diagnosis. However, the limited image signal‐to‐noise ratio, flow artefact, and varied lumen and outer wall become significant obstacles for automatic segmentation. A fully automatic framework is proposed for LB and OB segmentation in MR images. First, the lumen is identified by the support vector machine using a special strategy and LB is segmented by the geodesic star‐shape‐constrained graph cut. Then a novel global optimisation is developed to segment OB based on the graph cut, which consists of shape priors and appearance priors. The shape priors are learned from labelled shapes on LB and OB, while the appearance priors are modelled by Gaussian mixture models. A novel shape constraint is also designed as the constraint term. To evaluate author's method, extensive experiments are carried out from 160 MR images belonging to 16 patients. Experimental results demonstrate that the proposed method can yield high accuracy with fully automatic segmentation. Moreover, the advantages of the proposed method have been shown in terms of high flexibility and accuracy without user interactions in comparison with other methods.
Low‐light image enhancement with strong light weakening and bright halo suppressing
Authors: Tang Chaoying , Wang Yeru , Feng Huajun , Xu Zhihai , Li Qi , Chen Yueting
Published: December 2018

Low‐light enhancement methods suffer from the over‐enhancement problem which could induce the loss of the important texture and make images look unnatural. Moreover, some low‐light images contain strong light areas that must be weakened to improve the visual effect. In this study, an enhancement method with strong light weakening and bright halo suppressing is presented. Firstly, the bright channel prior is applied to the inverted image to weaken the strong light both in and around the strong light areas. Then, a dehazing‐type of algorithm with the dark channel prior is employed via superpixel segmentation to enhance the low‐light image. Finally, a revised non‐local denoising method is proposed to further refine the enhanced image. Experimental results showed that the proposed method achieved better visual effects compared with other state‐of‐the‐art methods. Besides, the quantitative evaluation showed that the authors’ method outperforms the other methods both in the aspect of enhancement and denoising.
Control of a STATCOM‐assisted self‐excited induction generator‐based WECS feeding non‐linear three‐phase and single‐phase loads
Authors: Satpathy Aradhya Sambhu , Kastha Debaprasad , Kishore Krishna
Published: December 2018

Self‐excited induction generator (SEIG)‐based wind energy conversion systems (WECS) are very popular for supplying stand‐alone loads at remote sites. The SEIG needs adjustable VAR to regulate its terminal voltage and frequency. Usually, a combination of a static compensator (STATCOM) and a fixed capacitor bank is used to meet this VAR demand. Here, a state feedback‐based control scheme is proposed to achieve independent control of the STATCOM DC‐link voltage and the SEIG terminal voltage. Further, to ensure harmonic‐free voltage at the SEIG terminal while supplying non‐linear three‐phase or single‐phase loads, a harmonic compensation technique is also developed. The wind turbine pitch angle control is utilised to regulate the frequency of the SEIG terminal voltage. The combined action of the proposed voltage control and pitch control strategies ensures that the load voltage and frequency are maintained at their respective rated values with very low harmonic distortion irrespective of variation in the wind speed and load demand. The performance of the proposed controllers (in terms of transient load voltage and frequency deviations and load voltage total harmonic distortion), as verified on a laboratory prototype, are found to be superior to that of similar controllers proposed in the literature.
Modular multilevel converters technology: a comprehensive study on its topologies, modelling, control and applications
Authors: Raju Manchala Naini , Sreedevi J. , P Mandi Rajashekar , Meera K.S.
Published: December 2018

A modular multilevel converter (MMC) is one of the perfect topologies for high power and medium‐/high‐voltage energy conversion systems. The MMC has attractive features such as modularity, voltage and current scalability, transformerless operation, fault blocking capability, reduced filter size, a reduced ripple of the output current, high efficiency, and low expense on redundancy. These features attracted industries over the past few years, notable research has been carried out on MMC topologies, their operation, and control. This study presents a review of MMC topologies and their mathematical models. Furthermore, their control schemes (classical as well as model predictive controls) and modulation techniques are discussed. Finally, MMC applications and their future challenges are highlighted.
Electric field calculation and grading ring design for 750 kV four‐circuits transmission line on the same tower with six cross‐arms
Authors: Huo Feng , Zhang Peng , Yu Yiliang , Liu Qin , Chu Lei , Wang Xuezong
Published: December 2018

The transmission corridors can be effectively saved using 750 kV four‐circuit transmission line on the same tower. In order to reduce the corona level, structure optimisation of fittings plays an important role in the transmission line design. In this study, the electric field distribution of 750 kV transmission line on six cross‐arms tower was calculated based on finite element method, and the influences of pipe diameter, ring diameter and installation position of the grading ring were analysed. The results show that the increase of pipe diameter can reduce the electric field strength of grading ring while the increase of installation position and decrease of ring diameter are important to protect the end fitting of composite insulator. When using grading ring with the pipe diameter of 100 mm, the ring diameter of 700–900 mm and the installation position of 150–250 mm, the electric field strength can be controlled in a reasonable range. These results can provide references for the grading ring design of 750 kV four‐circuit transmission line on the same tower.
Comparison of the passive and active control gust alleviation of a flying‐wing aircraft
Authors: Liu Ying
Published: December 2018

Various gust alleviation technologies including passive and active methods have been investigated. This research is focused on the gust response analysis of the flying‐wing aircraft with a gust alleviation device. Both passive and active approaches are investigated. Longitudinal analysis is involved in the gust response analysis. The model is longitudinally trimmed before gust response analysis. The result shows that efficiency is related to the frequency of deflection motion. The active control approach is more efficient than the passive gust control approach.
An Accurate Automated Local Similarity Factor-Based Neural Tree Approach toward Tissue Segmentation of Newborn Brain MRI
Authors: Jaware Tushar H. , Khanchandani K. B. , Zurani Anita
Published: December 2018

Background Segmentation of brain MR images of neonates is a primary step for assessment of brain evolvement. Advanced segmentation techniques used for adult brain MRI are not companionable for neonates, due to extensive dissimilarities in tissue properties and head structure. Existing segmentation methods for neonates utilizes brain atlases or requires manual elucidation, which results into improper and atlas dependent segmentation.

Objective The primary objective of this work is to develop fully automatic, atlas free, and robust system to segment and classify brain tissues of newborn infants from magnetic resonance images.

Study Design In this study, we propose a fully automatic, atlas-free pipeline based Neural Tree approach for segmentation of newborn brain MRI which utilizes resourceful local resemblance factor such as concerning, connectivity, structure, and relative tissue location. Physical collaboration and uses of an atlas are not required in proposed method and at the same time skirting atlas-associated bias which results in improved segmentation. Proposed technique segments and classify brain tissues both at global and tissue level.

Results We examined our results through visual assessment by neonatologists and quantitative comparisons that show first-rate concurrence with proficient manual segmentations. The implementation results of the proposed technique provided a good overall accuracy of 91.82% for the segmentation of brain tissues as compared with other methods.

Conclusion The pipelined-based neural tree approach along with local similarity factor segments and classify brain tissues. The proposed automated system have higher dice similarity coefficient as well as computational speed.
Distribution of Late-Onset Neonatal Sepsis Pathogens Differs in Inpatient and Outpatient Settings
Authors: Black Celeste G. , Tavares Larissa , Stachel Anna , Ratner Adam J. , Randis Tara M.
Published: December 2018

Objective We sought to examine pathogen distribution and clinical presentation of late-onset sepsis (LOS) at an urban tertiary care center.

Study Design We performed a retrospective review of all culture-confirmed cases of LOS presenting to our institution from 2013 to 2017. Medical records were evaluated for demographic information, sepsis risk factors, encounter location, and clinical outcome.

Results We identified 97 cases of LOS, with a median age at diagnosis of 25 days. The most common pathogens were Escherichia coli (22.7%), Staphylococcus aureus (17.5%), coagulase-negative staphylococci (12.4%), and Enterococcus faecalis (12.4%). Infections due to E. coli predominated in the outpatient setting (44%), whereas S. aureus and Gram-negative organisms other than E. coli were more frequently isolated from inpatients (21 and 24%, respectively). Gram-positive organisms were more common in infants delivered through cesarean section (p = 0.002) and were associated with more complications (p = 0.03). Escherichia coli LOS presented at an earlier age than S. aureus (15 vs. 32 days; p = 0.04). Of the 15 cases of meningitis, 40% did not have a positive blood culture.

Conclusion Pathogen distribution in our population was different from those previously reported, with a higher prevalence of S. aureus. Encounter location and age at presentation varied significantly by pathogen.
Preterm Prelabor Rupture of Membranes: Outcomes with Expectant Management until 34 versus 35 Weeks
Authors: Lynch Tara A. , Olson-Chen Courtney , Colihan Sarah , Meyers Jeffrey , Holloman Conisha , Li Dongmei , Link Heather , Torres Paola , Kim Annie , King Devon J. , Eckman Cari , Varlamov Anna , Dexter Scott , Pressman Eva K. , Soto-Torres Eleazar , Malshe Amol
Published: December 2018

Objective To evaluate outcomes with expectant management of preterm prelabor rupture of membranes (PROM) until 35 weeks versus immediate delivery at ≥34 weeks.

Study Design This was a multicenter retrospective cohort study of singletons with preterm PROM at >20 weeks from 2011 through 2017. Groups were defined as expectant management until 35 weeks versus immediate delivery at ≥34 weeks. Primary outcome was composite neonatal morbidity: need for respiratory support, culture positive neonatal sepsis, or antibiotic administration for >72 hours. Univariate and general estimating equation models were used with p < 0.05 considered significant.

Results A total of 280 mother–infant dyads were included. There was no difference in composite neonatal outcome in pregnancies managed with expectant management compared with immediate delivery (43.4 vs. 37.5%; p = 0.32). Those with expectant management had shorter length of neonatal intensive care unit (NICU) admission but higher rates of neonatal antibiotics for > 72 hours, endometritis, and histological chorioamnionitis. There were no cases of fetal demise, neonatal death, or maternal sepsis, and only three cases of neonatal sepsis.

Conclusion There is no difference in composite neonatal morbidity in pregnancies with preterm PROM managed with expectant management until 35 weeks as compared with immediate delivery at 34 weeks. Expectant management is associated with a decreased length of NICU admission but increased short-term infectious morbidity.
Downregulation of EIF5A2 by miR-221-3p inhibits cell proliferation, promotes cell cycle arrest and apoptosis in medulloblastoma cells
Authors: Yang Yong , Cui Hanjiang , Wang Xian
Published: December 2018

Recently, miR-221-3p expression has been reported to be down-regulated in medulloblastoma (MB), but its functional effects remains unclear. In this study, quantitative real-time PCR (qRT-PCR) revealed significantly decreased miR-221-3p in MB cell lines. Transfection of miR-221-3p mimics reduced, or inhibitor increased cell proliferation in MB cells using MTT assay. Flow cytometry analysis indicated miR-221-3p overexpression promoted, while knockdown alleviated G0/G1 arrest and apoptosis. Luciferase reporter assay confirmed miR-221-3p directly targets the EIF5A2 gene. Moreover, restoration of EIF5A2 in the miR-221-3p-overexpressing DAOY cells significantly alleviated the suppressive effects of miR-221-3p on cell proliferation, cell cycle and apoptosis. Furthermore, miR-221-3p overexpression decreased CDK4, Cyclin D1 and Bcl-2 and increased Bad expression, which was reversed by EIF5A2 overexpression. These results uncovered the tumor suppressive role of miR-221-3p in MB cell proliferation at least in part via targeting EIF5A2, suggesting that miR-221-3p might be a potential candidate target for diagnosis and therapeutics of MB.
Screen time and moderate‐to‐vigorous physical activity changes and displacement in adolescence: A prospective cohort study
Authors: Lizandra Jorge , Devís‐Devís José , Valencia‐Peris Alexandra , Tomás José M. , Peiró‐Velert Carmen
Published: December 2018

Background: This paper determines longitudinal changes in the time Spanish adolescents devote to moderate‐to‐vigorous physical activity (MVPA) and screen media activity (SMA). Moreover, it examines the displacement hypothesis between time spent on SMA and MVPA.

Methods: A cohort of 755 adolescents participated in a prospective cohort study over a three‐year period. Repeated measures ANOVA to highlight interaction effects among all variables and Structural Equation Modeling (SEM) techniques were employed.

Results: Age and gender‐related variations in longitudinal changes in time spent on MVPA and SMA evolved in the inverse direction (decreased on MVPA/increased on SMA) according to the ANOVA. The potential displacement between time spent on SMA and MVPA from Wave I to Wave II was analysed via SEM. The first model, estimated in the overall sample, showed no evidence for the displacement hypothesis. Subsequently, a multigroup sequence of panel models was performed and a partial displacement was observed only in boys. Hence, boys who spent more time on SMA were more likely to devote less time to MVPA three years later.

Conclusion: This study confirms the opposite trend on the time spent on MVPA and SMA over a three‐year period, being clearly higher in SMA. Further SEM analyses reveal a deferred displacement hypothesis between SMA and MVPA only in boys. This partial gendered displacement may be linked to the different uses adolescents make of screen media. The incursion of new technological devices (smartphones or tablets) and their wide range of possibilities for social networking or gaming could explain this displacement
Environmental advertising: the effect of imagery on pro-environmental attitudes and pro-environmental behaviour / Publicidad medioambiental: el efecto de las imágenes sobre las actitudes proambientales y el comportamiento proambiental
Authors: Soutter Alistair R. B. , Boag Simon
Published: December 2018

Conservation psychology is an emerging field, with few studies examining the role of advertising imagery on environmental attitudes and behaviours. This study aimed to expand the knowledge in this field, by examining how different types of imagery affect pro-environmental attitudes and behaviours. Undergraduate psychology students from Macquarie University ( N = 124) were assigned to one of three brochure groups. These brochure groups consisted of a hard copy brochure which contained either positive, negative or no images which participants read at the start of the study. Participants’ pro-environmental attitudes were then assessed using the New Ecological Paradigm, and behaviour through a hypothetical scenario in which respondents were asked to proportion $100 across three charity options or retain the money. It was found that positive imagery increased pro-environmental attitudes, over and above both the control (neutral) and negative images. In contrast, imagery did not affect pro-environmental behaviours. These findings suggest that positive images are most likely to elicit positive change in pro-environmental attitudes. However, these findings suggest that imagery in advertising does not impact pro-environmental behaviours.
Neo-Gnosticism, ideology and the culture wars: the contemplative antidote – perennial tensions: a reply to Jersak
Authors: Dart Ron S.
Published: December 2018

This reply speaks to Brad Jersak's analysis of the left–right culture wars spectrum and his critique of identity politics. He offers an alternative rooted in his studies of George P. Grant and Simone Weil's notion of the primacy of the Good vis-à-vis the triumph of the will that undergirds modernist assumptions. Jersak's thesis is confirmed and would be strengthened by careful attention Eric Voegelin's assessment of Gnosticism in The New Science of Politics. What needs further attention on the way of just peacemaking is the important turn from the vita activa to a sustained vita contemplativa as a way of knowing and being (cf. Merton). Finally, using Hermann Hesse's The Glass Bead Game (1946) reminds us of the inevitable clash between idealists and realists, raising the question of how, in the end, the owl of contemplative wisdom might navigate conflict between doves and hawks.
Major Lessons From Large-Scale Trap Cropping Demonstrations for Pest Reduction in Vegetables
Authors: Majumdar Ayanava , Price Matthew
Published: December 2018

Vegetable production in the Southeast is always at high risk from insect pests. Alternative integrated pest management (IPM) systems have to be effective in small plot as well as at the farming scale. This article explores the recent studies on large-scale trap crops using single or multiple cultivars and innovative layouts for long-term pest reduction. Trap crops must be planned carefully under high pest pressure and drought conditions along with an insecticide use strategy that minimizes external inputs and conserves natural enemies. Through participatory research approach, trap crop systems continue to evolve into practical solutions for the vegetable producers.
Optimal occlusion pattern for minimally invasive staged segmental artery coil embolization in a chronic porcine model
Authors: von Aspern Konstantin , Haunschild Josephina , Simoniuk Urszula , Kaiser Sven , Misfeld Martin , Mohr Friedrich W , Borger Michael A , Etz Christian D
Published: December 2018

OBJECTIVES

Minimally invasive staged segmental artery coil- and plug embolization (MIS2ACE) has been introduced for spinal cord injury prevention prior to open or endovascular thoraco-abdominal aortic aneurysm repair. To date, no optimal pattern has been developed. The aim of this study was to identify the optimal MIS2ACE occlusion pattern.

METHODS

Twenty-five juvenile pigs were randomly assigned to 3 MIS2ACE occlusion patterns (2 stages) and a control group [single-stage segmental artery (SA) occlusion, N = 7]. The first pattern started with occlusion of all lumbar segmental arteries in the first stage and the remaining thoracic arteries in the second stage (regional pattern, N = 6). In group 2, an alternating approach with occlusion of every other SA in the first stage and the remainder in the second stage was used (alternating pattern, N = 6). The third pattern started with occluding the watershed area between thoracic level 12 and lumbar level 2 in the first stage and the remaining arteries in the second stage (watershed pattern, N = 6). Neurological assessment at 6-h intervals and spinal cord tissue perfusion measurements via microspheres at 6 time points were performed. At the end of the experiments, the spinal cord was histopathologically examined.

RESULTS

An average of 6 ± 2 coils were used per SA. In the control group a total of 57% (N = 4) of animals experienced permanent paraplegia, 1 animal (16%) of the alternating and watershed intervention group suffered from permanent paraplegia. Animals from the staged regional pattern did not experience permanent paraplegia. Furthermore, no evidence of significant tissue damage was observed (P < 0.05 vs control). Tissue perfusion of the lumbar spinal cord in the regional pattern group recovered within 3 days after the second stage to 89.2 ± 47 percent-of-baseline (P = 0.393), whereas mean perfusion of the other 2 intervention groups and the control remained significantly lower compared to the baseline (35.7 ± 16%, 30.2 ± 11% and 63.2 ± 19, P < 0.05).

CONCLUSIONS

This study provides evidence that MIS2ACE (minimally invasive staging) may result in less ischaemic spinal cord injury and favourable neurological outcomes compared to complete (1 stage) SA occlusion. A regional-based occlusion pattern (starting with the lumbar segmental arteries) seems to be the best 2-stage approach.
Absence of HBV Reactivation in Patients With Resolved HBV Infection Following DAA Therapy for Hepatitis C: A 1-Year Follow-up Study
Authors: Mücke Marcus M , Mücke Victoria T , Peiffer Kai-Henrik , Sarrazin Christoph , Zeuzem Stefan , Berger Annemarie , Vermehren Johannes
Published: December 2018

Background

Patients with chronic hepatitis C virus (HCV) infection and active or previous hepatitis B virus (HBV) are at risk of HBV reactivation (HBV-R) during direct-acting antiviral (DAA) therapy. Recent reports suggest that HBV-R may even occur several months after completion of DAA therapy. The aim of this study was to assess the risk of HBV-R in patients with resolved HBV after successful DAA therapy during long-term follow-up (FU).

Methods

Among 848 patients treated for chronic HCV, all patients with resolved HBV and long-term FU data were eligible for inclusion. Patients were HBV DNA/hepatitis B surface antigen (HBsAg)–negative at the end of therapy (EOT) and were followed for up to 52 weeks thereafter. Patients underwent regular alanine transaminase (ALT) testing, and additional HBV DNA/HBsAg testing was performed at FU week 12, end of FU, and in case of an ALT increase above the upper limit of normal (>ULN).

Results

A total of 108 patients were followed up for a mean (range) of 41.5 (24–52) weeks after EOT. None of the patients experienced reverse HBsAg seroconversion or reappearance of HBV DNA. One patient received a liver transplantation; 1 patient was diagnosed with de novo hepatocellular carcinoma, and 2 patients died. Eighteen patients (16.7%) had increased ALT levels (grade 0/1). Of those, the majority were male (72.2%) and significantly more patients had cirrhosis (66.7% vs 36.2%, P = .015) or received ribavirin as part of their treatment regimen (86.7% vs 46.8%, P = .041). None of these were associated with HBV-R.

Conclusions

Our results indicate that the risk of HBV-R in patients with resolved HBV treated with DAAs for HCV is low during long-term follow-up.
Impairment of Inhibition of Trigeminal Nociception via Conditioned Pain Modulation in Persons with Migraine Headaches
Authors: Williams Amy E , Miller Megan M , Bartley Emily J , McCabe Klanci M , Kerr Kara L , Rhudy Jamie L
Published: December 2018

Objective

To assess conditioned pain modulation efficiency in persons with and without migraine headaches.

Design

Cross-sectional assessment of experimental pain.

Setting

University campus and surrounding community in a large Midwestern US city.

Subjects

Twenty-three adults with and 32 without a history of migraine headaches participated in the study. Participants were mostly female (N = 40) with an average age of 23 years.

Methods

Four electrocutaneous stimulations of the supraorbital branch of the left trigeminal nerve were delivered at 150% of an individually determined pain threshold. Conditioned pain modulation was assessed by applying a noxious counterstimulus (forearm ischemia) and delivering four more electrocutaneous stimulations. After each stimulation, pain and the nociceptive blink reflex were assessed. Depression and pain catastrophizing were assessed to control for the potential influence of these variables on pain modulation.

Results

Participants with and without migraine headaches had similar baseline pain responsivity, without significant differences in pain report or nociceptive blink reflexes. Pain report was inhibited by conditioned pain modulation in both the migraine and control groups. However, unlike nonmigraine controls, participants with migraines did not exhibit an inhibition of nociceptive blink reflexes during the ischemia task. This pattern persisted after controlling for level of pain catastrophizing and depression.

Conclusions

Migraine sufferers exhibited impaired conditioned pain modulation of the nociceptive blink reflex, suggesting a deficiency in inhibition of trigeminal nociception, which may contribute to the development of migraine headaches.
Infant Outcome After Complete Uterine Rupture
Authors: Al-Zirqi Iqbal , Daltveit Anne Kjersti , Vangen Siri
Published: December 2018

(Abstracted from Am J Obstet Gynecol 2018;219:109.e1–109.e8)

Complete uterine rupture is a relatively rare complication that is associated with a catastrophic outcome for both the mother and offspring. There are few large studies powered to examine both severe maternal and infant outcome after complete ruptures because of this complication's rarity and also because of the use of international diagnostic codes that do not differentiate between the less catastrophic partial rupture and more catastrophic complete uterine rupture.
Individual Patient-reported Activity Levels Before and After Joint Arthroplasty Are Neither Accurate nor Reproducible
Authors: Vaughn Natalie H. , Dunklebarger Mitchell F. , Mason Mark W.
Published: December 2018

Background

Patients often are asked to report walking distances before joint arthroplasty and when discussing their results after surgery, but little evidence demonstrates whether patient responses accurately represent their activity.

Questions/purposes

Are patients accurate in reporting distance walked, when compared with distance measured by an accelerometer, within a 50% margin of error?

Methods

Patients undergoing THA or TKA were recruited over a 16-month period. One hundred twenty-one patients were screened and 66 patients (55%) were enrolled. There were no differences in mean age (p = 0.68), proportion of hips versus knees (p = 0.95), or sex (p = 0.16) between screened and enrolled patients. Each patient wore a FitBitTM Zip accelerometer for 1 week and was blinded to its measurements. The patients reported their perceived walking distance in miles daily. Data were collected preoperatively and 6 to 8 weeks postoperatively. Responses were normalized against the accelerometer distances and Wilcoxon one-tailed signed-rank testing was performed to compare the mean patient error with a 50% margin of error, our primary endpoint.

Results

We found that patients’ self-reported walking distances were not accurate. The mean error of reporting was > 50% both preoperatively (p = 0.002) and postoperatively (p < 0.001). The mean magnitude of error was 69% (SD 58%) preoperatively and 93% (SD 86%) postoperatively and increased with time (p = 0.001).

Conclusions

Patients’ estimates of daily walking distances differed substantially from those patients’ walking distances as recorded by an accelerometer, the accuracy of which has been validated in treadmill tests. Providers should exercise caution when interpreting patient-reported activity levels.

Level of Evidence

Level III, diagnostic study.
Incidence, Risk Factors, Progression, and Treatment of Endovenous Heat-Induced Thrombosis Class 2 or Greater After Endovenous Radiofrequency Ablation
Authors: Sermsathanasawadi Nuttawut , Pitaksantayothin Wacharaphong , Puangpunngam Nattawut , Chinsakchai Khamin , Wongwanit Chumpol , Mutirangura Pramook , Ruangsetakit Chanean
Published: December 2018

BACKGROUND

Endovenous heat-induced thrombosis (EHIT) is a thrombus that extends from an ablated saphenous vein into the common femoral vein after endovenous radiofrequency ablation (RFA).

OBJECTIVE

To investigate the incidence, progression, treatment, and risk factors associated with EHIT-2 or greater after RFA.

MATERIALS AND METHODS

This retrospective study included patients diagnosed with symptomatic superficial venous incompetence that were treated by RFA of the great saphenous vein or anterior accessory saphenous vein during the July 2012 to December 2016 study period. Duplex ultrasound scanning was performed at 1 week, 1 month, 3 months, and every year after RFA to detect EHIT.

RESULTS

A total of 317 legs from 274 patients were included. The incidence of EHIT-2 or greater was 7.0%, including 5.4% EHIT-2, 1.3% EHIT-3, and 0.3% EHIT-4. No symptomatic pulmonary embolism was found. The independent risk factors for EHIT-2 or greater were vein diameter (p = .027) and concomitant sclerotherapy (p = .037).

CONCLUSION

The risk factors found to be independently associated with EHIT-2 or greater were large vein size and concomitant sclerotherapy. Screening for EHIT should be performed in patients with one or both of these risk factors within 1 week after RFA and in patients with postoperative symptoms suggestive of venous thromboembolism.
Comparisons of Submental and Groin Vascularized Lymph Node Flaps Transfer for Breast Cancer-Related Lymphedema
Authors: Ho Olivia A. , Lin Chia-Yu , Pappalardo Marco , Cheng Ming-Huei
Published: December 2018

Background:

The vascularized groin and submental lymph node (VGLN and VSLN) flaps are valuable options in the treatment of lymphedema. This study was to compare outcomes between VGLN and VSLN transfers for breast cancer–related lymphedema.

Methods:

Between January 2008 and December 2016, VGLN and VSLN transfers for upper limb lymphedema were compared including flap characteristics, flap elevation time, complications, and limb circumference changes.

Results:

All flaps survived. Similar vein (2.6 versus 3.2 mm;P= 0.3) and artery diameter (2.1 versus 2.8 mm;P= 0.3) and number of lymph nodes (3 versus 4;P= 0.4) were found between VGLN and VSLN groups, respectively. Circumferential reduction rate was higher in VSLN than VGLN (P= 0.04) group. Vascular complication rate with salvage rate was not statistically different between the 2 groups. Donor-site complication and total complication rates were statistically higher in VGLN than VSLN flaps (7.7% versus 0%,P= 0.004; 46.2% versus 23.3%,P= 0.002). At a mean 39.8 ± 22.4 months, the circumferential reduction rate was statistically higher in VSLN than in the VGLN group (55.5 ± 14.3% versus 48.4 ± 23.9%,P= 0.04). Both flaps were effectively decreased in the episodes of cellulitis.

Conclusions:

Both VGLN and VSLN flaps are valuable surgical options in treating breast cancer–related lymphedema. However, the VSLN flap for breast cancer–related lymphedema is better in providing more significant improvements in limb circumference, a faster flap harvest time, decreased complication rates, and minimal donor-site iatrogenic lymphedema.