bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mode‐Locking of All‐Fiber Lasers Operating at Both Anomalous and Normal Dispersion Regimes in the C‐ and L‐Bands Using Thin Film of 2D Perovskite Crystallites
Authors: Hong Seongjin , Lédée Ferdinand , Park Jaedeok , Song Sanggwon , Lee Hyeonwoo , Lee Yong Soo , Kim Byungjoo , Yeom Dong‐Il , Deleporte Emmanuelle , Oh Kyunghwan 
Published: September 2018

AbstractTwo‐dimensional hybrid organic–inorganic perovskites have recently attracted attention in various optoelectronic applications. A novel thin film of 2D perovskite (C6H5C2H4NH3)2PbI4 crystallites is synthesized and its nonlinear optical properties are experimentally investigated within the optical gain of an Erbium‐doped fiber. Utilizing its unique nonlinear optical response, efficient mode‐locking of an all‐fiber Erbium laser is demonstrated at the anomalous dispersion regime in both the C‐ and L‐bands stably generating femtosecond pulse trains, where the thin film of 2D perovskite crystallites function as an in‐line saturable absorber. At this anomalous dispersion regime, self‐started femtosecond pulses are generated whose center wavelength are tuned from 1565.9 nm in C‐band and 1604 nm in L‐band by adjusting the optical gain. Furthermore, by managing the chromatic dispersion of the total fiber laser cavity to reach the normal dispersion regime, a stable dissipative soliton is successfully generated in the C‐band with the spectral bandwidth of 15 nm and pulse duration of 3.2 ps. Detailed material properties of the thin film of 2D perovskite crystallites, their characterization, and fiber laser mode‐locking performance is reported.
A framework for performance characterization of energy‐resolving photon‐counting detectors
Authors: Persson Mats , Rajbhandary Paurakh L. , Pelc Norbert J. 
Published: September 2018

PurposePhoton‐counting, energy‐resolving detectors are subject to intense research interest, and there is a need for a general framework for performance assessment of these detectors. The commonly used linear‐systems theory framework, which measures detector performance in terms of noise‐equivalent quanta (NEQ) and detective quantum efficiency (DQE) is widely used for characterizing conventional x‐ray detectors but does not take energy‐resolving capabilities into account. The purpose of this work is to extend this framework to encompass energy‐resolving photon‐counting detectors and elucidate how the imperfect energy response and other imperfections in real‐world detectors affect imaging performance, both for feature detection and for material quantification tasks.MethodWe generalize NEQ and DQE to matrix‐valued quantities as functions of spatial frequency, and show how these matrices can be calculated from simple Monte Carlo simulations. To demonstrate how the new metrics can be interpreted, we compute them for simplified models of fluorescence and Compton scatter in a photon‐counting detector and for a Monte Carlo model of a CdTe detector with pixels.ResultsOur results show that the ideal‐linear‐observer performance for any detection or material quantification task can be calculated from the proposed generalized NEQ and DQE metrics. We also demonstrate that the proposed NEQ metric is closely related to a generalized version of the Cramér‐Rao lower bound commonly used for assessing material quantification performance. Off‐diagonal elements in the NEQ and DQE matrices are shown to be related to loss of energy information due to imperfect energy resolution. The Monte Carlo model of the CdTe detector predicts a zero‐frequency dose efficiency relative to an ideal detector of 0.86 and 0.65 for detecting water and bone, respectively. When the task instead is to quantify these materials, the corresponding values are 0.34 for water and 0.26 for bone.ConclusionsWe have developed a framework for assessing the performance of photon‐counting energy‐resolving detectors and shown that the matrix‐valued NEQ and DQE metrics contain sufficient information for calculating the dose efficiency for both detection and quantification tasks, the task having any spatial and energy dependence. This framework will be beneficial for the development and optimization of photon‐counting x‐ray detectors.
Theoretical and experimental analysis of photon counting detector CT for proton stopping power prediction
Authors: Taasti Vicki T. , Hansen David C. , Michalak Gregory J. , Deisher Amanda J. , Kruse Jon J. , Muren Ludvig P. , Petersen Jørgen B. B. , McCollough Cynthia H. 
Published: September 2018

PurposePhoton counting detectors (PCDs) are being introduced in advanced x‐ray computed tomography (CT) scanners. From a single PCD‐CT acquisition, multiple images can be reconstructed, each based on only a part of the original x‐ray spectrum. In this study, we investigated whether PCD‐CT can be used to estimate stopping power ratios (SPRs) for proton therapy treatment planning, both by comparing to other SPR methods proposed for single energy CT (SECT) and dual energy CT (DECT) as well as to experimental measurements.MethodsA previously developed DECT‐based SPR estimation method was adapted to PCD‐CT data, by adjusting the estimation equations to allow for more energy spectra. The method was calibrated directly on noisy data to increase the robustness toward image noise. The new PCD SPR estimation method was tested in theoretical calculations as well as in an experimental setup, using both four and two energy bin PCD‐CT images, and through comparison to two other SPR methods proposed for SECT and DECT. These two methods were also evaluated on PCD‐CT images, full spectrum (one‐bin) or two‐bin images, respectively. In a theoretical framework, we evaluated the effect of patient‐specific tissue variations (density and elemental composition) and image noise on the SPR accuracy; the latter effect was assessed by applying three different noise levels (low, medium, and high noise). SPR estimates derived using real PCD‐CT images were compared to experimentally measured SPRs in nine organic tissue samples, including fat, muscle, and bone tissues.ResultsFor the theoretical calculations, the root‐mean‐square error (RMSE) of the SPR estimation was 0.1% for the new PCD method using both two and four energy bins, compared to 0.2% and 0.7% for the DECT‐ and SECT‐based method, respectively. The PCD method was found to be very robust toward CT image noise, with a RMSE of 2.7% when high noise was added to the CT numbers. Introducing tissue variations, the RMSE only increased to 0.5%; even when adding high image noise to the changed tissues, the RMSE stayed within 3.1%. In the experimental measurements, the RMSE over the nine tissue samples was 0.8% when using two energy bins, and 1.0% for the four‐bin images.ConclusionsIn all tested cases, the new PCD method produced similar or better results than the SECT‐ and DECT‐based methods, showing an overall improvement of the SPR accuracy. This study thus demonstrated that PCD‐CT scans will be a qualified candidate for SPR estimations.
Gait pattern changes after six‐minute walk test in persons with multiple sclerosis
Authors: Escudero‐Uribe Shahid , Hochsprung Anja , Izquierdo‐Ayuso Guillermo 
Published: September 2018

AbstractObjectiveTo examine the effect of induced fatigue on spatiotemporal gait parameters in persons with multiple sclerosis (PwMS) by using 6‐min walk test (6MWT).MethodsA cross‐sectional study with a control group (25 healthy persons) was performed. Fifty‐six PwMS (37 female) were divided into three groups according to their level of disability, as measured by the expanded disability status scale (EDSS): mild (n = 23, EDSS = 1.0–3.5), moderate (n = 19, EDSS = 4.0–5.5), and severe (n = 12, EDSS = 6.0–6.5). Spatiotemporal gait parameters were measured by the GAITRite electronic walkway before and after 6MWT performance. In addition, to determine the level of fatigue in PwMS, the participants completed the questionnaire modified fatigue impact scale (MFIS) before performing the 6MWT. Statistical analyses were performed to compare intragroup and intergroup differences.ResultsFatigue level was lower in the mild (37.6 ± 20.5) versus moderate (54.3 ± 17.2) versus severe (53.6 ± 12.9) groups (p < 0.05). Significant differences were found among all the groups in terms of the distance walked during the 6MWT (p = 0.001) and of the spatiotemporal gait parameters: gait velocity (cm/s), cadence (steps/min), and step length (cm) decreased and, on the contrary, step time (sec), stance, and double support time (% gait cycle) increased when EDSS scores were higher (p < 0.05). The percentage of change (%) in the spatiotemporal gait parameters, after 6MWT performance, was statistically significant in the moderate and severe groups: gait velocity (−8.8%, −25.9%) and step length (−6.5%, −13.4%) decreased, whereas step time (3.0%, 15.0%), double support time (8.8%, 19.1%), step time asymmetry (32.1%, 64.0%), and single support asymmetry (60.0%, 74.7%) increased (p < 0.05).ConclusionsGait pattern worsen after performing a walking‐induced fatigue test, such as 6MWT, in moderate–severe PwMS (EDSS ≥ 4.0). Identifying these gait alterations will allow physiotherapists to determine specific therapeutic objectives.
Effects of clothianidin‐treated seed on the arthropod community in a mid‐Atlantic no‐till corn agroecosystem
Authors: Disque Heather H , Hamby Kelly A , Dubey Aditi , Taylor Christopher , Dively Galen P 
Published: September 2018

AbstractBACKGROUNDNearly all corn seed in the US is coated with neonicotinoid insecticides to protect against soil and foliar arthropod pests. Exposure in the soil and the systemic activity in the plant can pose non‐target risks. We assessed the community‐level effects of clothianidin‐treated seed on the diversity and abundance of arthropod communities in a no‐till corn agroecosystem over a single growing season.RESULTSEpigeal and foliage‐dwelling communities were disturbed by the clothianidin seed treatment, with significant negative and positive changes in taxa abundances. Clothianidin reduced the abundance of minute pirate bugs by 66.2%, lady beetles by 44.7%, ants by 43.4%, ground beetle adults and larvae by 31.7%, and rove beetles by 44.1% during the early corn growth stages. Herbivores, particularly thrips, were more negatively affected by clothianidin than other trophic groups. In contrast, some groups, such as collembolans and leafhoppers, exhibited significantly higher abundances in the seed treated plots.CONCLUSIONClothianidin primarily influenced arthropod communities during the 4 weeks following planting, with disruptions to major natural enemy taxa, but communities showed trends toward recovery at the later corn stages. While the insecticide suppressed multiple herbivores, none were economically damaging to corn; thus, the pest suppression benefits of clothianidin observed in this study did not justify the non‐target impacts. © 2018 Society of Chemical Industry
Performance of semiconductor sequencing platform for non‐invasive prenatal genetic screening for fetal aneuploidy: results from a multicenter prospective cohort study in a clinical setting
Authors: El Khattabi L. Allach , Brun S. , Gueguen P. , Chatron N. , Guichoux E. , Schutz S. , Nectoux J. , Sorlin A. , Quere M. , Boudjarane J. , Tsatsaris V. , Mandelbrot L. , Schluth‐Bolard C. , Dupont J. M. , Rooryck C. ,   the H+ Consortium
Published: September 2018

ABSTRACTObjectiveTo validate and evaluate the performance metrics of the high‐throughput semiconductor sequencing platform, Ion Proton®, in non‐invasive prenatal genetic screening (NIPS) for common fetal aneuploidies in a clinical setting.MethodsThis prospective cohort study included 2505 pregnant women from eight academic genetics laboratories (695 high risk for trisomy 21 (risk ≥ 1/250) pregnancies in a validation study, and 1810 such pregnancies, without ultrasound anomalies, in a real‐life NIPS clinical setting). Outcome was available for all cases in the validation cohort and for 521 in the clinical cohort. Cell‐free DNA from plasma samples was sequenced using the Ion Proton sequencer, and sequencing data were analyzed using the open‐access software, WISECONDOR. Performance metrics for detection of trisomies 21, 18 and 13 were calculated based on either fetal karyotype result or clinical data collected at birth. We also evaluated the failure rate and compared three methods of fetal fraction quantification (RASSF1A assay, and DEFRAG and SANEFALCON software).ResultsResults from both cohorts were consistent and their gestational age was not significantly different so their data were combined to increase the sample size for analysis. Sensitivities and specificities, respectively, were as follows: for trisomy 21, 98.3% (95% CI, 93.5–99.7%) and 99.9% (95% CI, 99.4–100%); for trisomy 18, 96.7% (95% CI, 80.9–99.8%) and 100% (95% CI, 99.6–100%); and for trisomy 13, 94.1% (95% CI, 69.2–99.7%) and 100% (95% CI, 99.6–100%). Our failure rate was 1.2% initially and as low as 0.6% after retesting some of the failed samples. Fetal fraction estimation by the RASSF1A assay was consistent with DEFRAG results, and both were adequate for routine diagnosis.ConclusionsWe describe one of the largest studies evaluating Ion Proton‐based NIPS and the first clinical study reporting pregnancy outcome in a large series of patients. This platform is highly efficient in detecting the three most common trisomies. Our protocol is robust and can be implemented easily in any medical genetics laboratory. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.
Attention Speculation and Political Bubbles
Authors: Hendricks Vincent F. , Vestergaard Mads 
Published: September 2018

AbstractWe live in an increasingly mediatized world. Mediatization refers to the tendency of societal institutions to be more and more dependent on the media and adapt themselves to its conventions and to media logic (Hjarvad 2008). In a mediatized society, the media veritably establish the conditions for social interactions and relationships, commerce and marketing, science and debate, and activism and politics. When political activists protest or organize a demonstration in order to send a political message, it is essential to get media coverage. The message must be heard by people and parties other than the activists themselves. There is no point in “Occupying Wall Street” unless documented and disseminated. Mediatization provides social and political actors with a strong incentive to act according to the media’s precepts.
Epilogue: Digital Roads to Totalitarianism
Authors: Hendricks Vincent F. , Vestergaard Mads 
Published: September 2018

AbstractThe digital revolution was meant to emancipate. In the Declaration of the Independence of Cyberspace from 1996, John Berry Barlow declares the new digital reality, Cyberspace, to be an independent new world of freedom and equality without oppression of the old world of nation-states ruled by governments. Barlow compares the digital revolution to the American War of Independence and the pioneers of digitalization to the heroes of the American Revolution: “… those previous lovers of freedom and self-determination who had to reject the authorities of distant, uninformed powers.”
The diagnostic challenge in very‐long chain acyl‐CoA dehydrogenase deficiency (VLCADD)
Authors: Hesse Julia , Braun Carina , Behringer Sidney , Matysiak Uta , Spiekerkoetter Ute , Tucci Sara 
Published: September 2018

AbstractVery long‐chain acyl‐CoA dehydrogenase deficiency (VLCADD) is the most common defect of mitochondrial β‐oxidation of long‐chain fatty acids. However, the unambiguous diagnosis of true VLCADD patients may be challenging, and a high rate of false positive individuals identified by newborn screening undergo confirmation diagnostics. In this study, we show the outcome of enzyme testing in lymphocytes as a confirmatory tool in newborns identified by screening, and the correlation with molecular sequencing of the ACADVL gene. From April 2013 to March 2017, in 403 individuals with characteristic acylcarnitine profiles indicative of VLCADD, palmitoyl‐CoA oxidation was measured followed by molecular genetic analysis in most of the patients with residual activity (RA) <50%. In almost 50% of the samples (209/403) the RA was >50%, one‐third of the individuals (125/403) displayed a RA of 30–50% and 69/403 individuals showed a residual activity of 0–30%. Sequencing of the ACADVL gene revealed that all individuals with activities below 24% were true VLCADD patients, individuals with residual activities between 24 and 27% carried either one or two mutations. Twenty new mutations could be identified and functionally classified based on their effect on enzyme function. Finally, we observed an up‐regulation of MCAD‐activity in many patients. However, this did not correlate with the degree of VLCAD RA. Although the likely clinical phenotype cannot be fully foreseen by genetic and functional tests as it depends on many factors, our data demonstrate the strength of this functional enzyme test in lymphocytes as a quick and reliable method for confirmation diagnostics of VLCADD.
Mamma Mia – A randomized controlled trial of an internet-based intervention for perinatal depression
Authors: Haga Silje Marie , Drozd Filip , Lisøy Carina , Wentzel-Larsen Tore , Slinning Kari 
Published: September 2018

AbstractBackgroundStudies suggest that 10–15% of perinatal women experience depressive symptoms. Due to the risks, problems with detection, and barriers to treatment, effective universal preventive interventions are needed. The aim of this study was to assess the effectiveness of an automated internet intervention (‘Mamma Mia’) on perinatal depressive symptoms. Mamma Mia is tailored specifically to the perinatal phase and targets risk and protective factors for perinatal depressive symptoms.MethodsA total of 1342 pregnant women were randomized to an intervention (‘Mamma Mia’) and control group. Data were collected at gestational week (gw) 21–25, gw37, 6 weeks after birth, and 3 and 6 months after birth. We investigated whether (1) the intervention group displayed lower levels of depressive symptoms compared with the control group, (2) the effect of Mamma Mia changed over time, (3) the effect on depressive symptoms was moderated by baseline depressive symptoms, previous depression, and parity, and (4) this moderation changed by time. Finally, we examined if the prevalence of mothers with possible depression [i.e. Edinburgh Postnatal Depression Scale (EPDS)-score ⩾10] differed between the intervention and control group.ResultsParticipants in the Mamma Mia group displayed less depressive symptoms than participants in the control group during follow-up [F(1) = 7.03, p = 0.008]. There were indications that the effect of Mamma Mia was moderated by EPDS score at baseline. The prevalence of women with EPDS-score ⩾10 was lower in the Mamma Mia group at all follow-up measurements.ConclusionsThe study demonstrated the effects of the automated web-based universal intervention Mamma Mia on perinatal depressive symptoms.
Efficacy of Halauxifen-Methyl on Glyphosate-Resistant Horseweed (Erigeron canadensis)
Authors: McCauley Cara L. , Johnson William G. , Young Bryan G. 
Published: September 2018

AbstractHalauxifen-methyl is a new synthetic auxin herbicide for control of broadleaf weeds, including preplant applications for corn (Zea maysL.) or soybean [Glycine max(L.) Merr.]. The objective of this study was to investigate the efficacy of halauxifen-methyl in comparison to the current auxin standards, 2,4-D and dicamba, on glyphosate-resistant (GR) horseweed (Erigeron canadensisL.) at different plant heights. In field experiments, a foliar application of halauxifen-methyl at the recommended use rate of 5 g ae ha−1resulted in 81% control. Dicamba applied at 280 g ae ha−1provided a comparable level of efficacy of 80%, while 2,4-D at 560 g ae ha−1resulted in 49% control. The addition of glyphosate improved GRE. canadensiscontrol with 2,4-D more than with halauxifen-methyl or dicamba, possibly due to the higher level of control observed with halauxifen-methyl or dicamba alone. Even though applied at 50 to 100 times lower application rates, the efficacy of halauxifen-methyl onE. canadensiswas similar to dicamba and greater than 2,4-D. Thus, halauxifen-methyl should be an effective tool for management of GRE. canadensisbefore planting both conventional and herbicide-resistant soybean varieties, and it precludes the extended preplant application interval required for dicamba in some soybean management systems.
Ionospheric Scintillation Fading Coefficients for the GPS L1, L2, and L5 Frequencies
Authors: de O. Moraes Alison , Vani Bruno C. , Costa Emanoel , Sousasantos Jonas , Abdu Mangalathayil A. , Rodrigues Fabiano , Gladek Yuri C. , de Oliveira César B. A. , Monico João F. Galera 
Published: September 2018

AbstractThe terrestrial ionosphere over low‐latitude regions presents the unique phenomena of the equatorial ionization anomaly (characterized by global maximum in plasma concentration) and plasma‐depleted regions known as equatorial plasma bubbles and associated smaller‐scale plasma irregularities. Transionospheric radio signals such as those from Global Navigation Satellite Systems constellations, traveling across this ambient, may suffer severe scintillation in amplitude and phase due to these plasma structures. Presently, three civilian signals available for GPS users, at L1 (1575.42 MHz), L2C (1227.60 MHz), and L5 (1176.45 MHz) are used to investigate the propagation effects due to these irregularities. The purpose of the present work is to evaluate statistically the distribution of severe fade events for each of these carrier frequencies based on the nonlinear ionospheric propagation effects as represented by the fading coefficients of α‐μ distribution. The results from the analyses of data sets recorded by stations at different geomagnetic latitude locations in Brazil show that regions closer to the equatorial ionization anomaly crest present higher probability of severe fade events. Additionally, the L5 signals, dedicated for safety‐of‐life applications, revealed more unfavorable results when compared to the L1 and L2C frequencies. The results further showed that for 0.8 ≤ S4 ≤ 1.0 the probabilities of fades deeper than −10 dB were between 8.0% and 6.5% depending on the station position. Considering the case of fades deeper than −20 dB, the results reach values near 1%, which is quite concerning. These results show empirically the fading environment that users of the new civilian signals may experience in low‐latitude region. Additionally, the fading coefficients may help in the comprehension of the distribution of amplitude scintillation and its relation with the frequency used, aiding in the future the development of signal processing algorithms capable to mitigate errors for navigation users.
Telluric Field Variations as Drivers of Variations in Cathodic Protection Potential on a Natural Gas Pipeline in New Zealand
Authors: Ingham M. , Rodger C. J. 
Published: September 2018

AbstractA study of variations in cathodic protection potential on a natural gas pipeline in the North Island of New Zealand is reported. Both the measured pipe‐to‐soil potential (PSP) and the current measured through an installed defect in the pipeline coating show strong correlations with variations in measured magnetic and telluric fields. Contrary to predictions from distributed‐source transmission line theory, analysis shows that the closest correlations of PSP and current are with the component of telluric field perpendicular to the pipeline. This orientation is close to perpendicular to major electrical conductivity contrasts associated with both the local coastline and with on‐shore Earth conductivity structure. It is therefore inferred the variations in PSP which drive the variations in defect current are the result of changes in the local Earth potential. While reporting on specific observations from New Zealand, these results should be applicable across a wide range of middle and high‐latitude global locations. Estimates of possible corrosion rates for the pipeline in question suggest that such enhancement of telluric field variations by conductivity structure may pose significant risk to pipelines in the event of defects in the pipeline coating.