bluuebunny/crossref_metadata_2025_split huggingface dataset:
Primary fetal pleural effusion: Characteristics, outcomes, and the role of intervention
Authors: Shamshirsaz Alireza A. , Erfani Hadi , Aalipour Soroush , Shah Sohum C. , Nassr Ahmed A. , Stewart Kelsey A. , Rezaei Atefeh , Sanz Cortes Magdalena , Espinoza Jimmy , Belfort Michael A. 
Published: April 2019

AbstractBackgroundWe aimed to present the natural history and outcomes of fetal primary pleural effusions (PPE).MethodsFetuses with prenatal diagnosis of PPE delivered between January 2011 and June 2018 were included. Fetal PPE were separated into groups: resolved, stable, or progressive. Progressive PPE was diagnosed, using fetal echocardiography, by the new onset of fetal hydrops or impaired cardiac function. Data were reported as median [range] and n (%).ResultsAmong 189 fetuses with antenatal diagnosis of pleural effusion, 30 had a PPE. A total of 26.7% (n = 8), 26.7% (n = 8), and 40.0% (n = 12) were classified as resolved, stable, and progressive, respectively; two were lost to follow‐up. In 14 cases (50%), there were bilateral pleural effusions. Of the 12 cases in the progressive group, four (33.3%) had amnioreduction, six (50.0%) had thoracentesis, and eight (66.7%) had shunt placement performed. There were two fetal deaths, both in the progressive group, one of which received amnioreduction and the other underwent both thoracentesis and shunt placement prior to demise.ConclusionIn more than half of fetuses with prenatal PPE, the effusion remained stable or spontaneously resolved, and the perinatal outcomes were generally favorable. This information will be useful in optimizing the counseling and care of these patients.
Do combined upper airway cultures identify lower airway infections in children with chronic cough?
Authors: Hare Kim M. , Chang Anne B. , Smith‐Vaughan Heidi C. , Bauert Paul A. , Spain Brian , Beissbarth Jemima , Grimwood Keith 
Published: April 2019

AbstractBackgroundObtaining lower airway specimens is important for guiding therapy in chronic lung infection but is difficult in young children unable to expectorate. While culture‐based studies have assessed the diagnostic accuracy of nasopharyngeal or oropharyngeal specimens for identifying lower airway infection, none have used both together. We compared respiratory bacterial pathogens cultured from nasopharyngeal and oropharyngeal swabs with bronchoalveolar lavage (BAL) cultures as the “gold standard” to better inform the diagnosis of lower airway infection in children with chronic wet cough.MethodsNasopharyngeal and oropharyngeal swabs and BAL fluid specimens were collected concurrently from consecutive children undergoing flexible bronchoscopy for chronic cough and cultured for bacterial pathogens.ResultsIn cultures from 309 children (median age, 2.3 years) with chronic endobronchial suppuration, all main pathogens detected (Haemophilus influenzae, Streptococcus pneumoniae, and Moraxella catarrhalis) were more prevalent in nasopharyngeal than oropharyngeal swabs (37%, 34%, and 23% vs 21%, 6.2%, and 3.2%, respectively). Positive and negative predictive values for lower airway infection by any of these three pathogens were 63% (95% confidence interval [95% CI] 55, 70) and 85% (95% CI, 78, 91) for nasopharyngeal swabs, 65% (95% CI, 54, 75), and 66% (95% CI, 59, 72) for oropharyngeal swabs, and 61% (95% CI, 54,68), and 88% (95% CI, 81, 93) for both swabs, respectively.ConclusionsNeither nasopharyngeal nor oropharyngeal swabs, alone or in combination, reliably predicted lower airway infection in children with chronic wet cough. Although upper airway specimens may be useful for bacterial carriage studies and monitoring antimicrobial resistance, their clinical utility in pediatric chronic lung disorders of endobronchial suppuration is limited.
One‐pot synthesis, structure and structure–activity relationship of novel bioactive diphenyl/diethyl (3‐bromo‐1‐(3‐chloropyridin‐2‐yl)‐1H‐pyrazol‐5‐yl)(arylamino)methylphosphonates
Authors: Wang Bao‐Lei , Zhu Hong‐Wei , Li Zheng‐Ming , Zhang Xiao , Yu Shu‐Jing , Ma Yi , Song Hai‐Bin 
Published: April 2019

AbstractBACKGROUNDN‐Pyridylpyrazole derivatives have received continuous attention in agrochemical research during the last decade owing to their remarkable insecticidal or fungicidal potentials. To look for novel heterocyclic agrochemicals for increasing production of agriculture, a series of novel α‐aminophosphonate derivatives containing N‐pyridylpyrazole moiety were synthesized.RESULTSThe structures of the title compounds were confirmed via melting point, IR, 1H NMR, 13C NMR, 31P NMR, HRMS and elemental analysis. The single crystal structure of diethyl (3‐bromo‐1‐(3‐chloropyridin‐2‐yl)‐1H‐pyrazol‐5‐yl)(2,6‐dimethylphenylamino)methylphosphonate (compound 12b) was first reported. Moreover, the bioassays displayed that the title compounds exhibited modest or weak insecticidal activities against oriental armyworm at 200 μg mL−1. The first investigation on the fungicidal potential of chlorantraniliprole showed no significant activities towards the six tested fungi found in this study, however, most of the title compounds displayed apparent in vitro fungicidal activity against some plant fungi, in particular excellent activities towards Physalospora piricola. Compounds 11a and 11b had EC50 values of 18.8 and 17.4 μg mL−1, respectively, which were comparable with that of fungicide control triadimefon (EC50 = 24.7 μg mL−1) against Physalospora piricola. In addition, some compounds exhibited modest in vivo control efficacy at 0.5 mg mL−1 towards Sclerotinia sclerotiorum (11b: 30.1(±1.8)%), Rhizoctonia cerealis (11a: 20.4(±2.1)%; 11b: 30.2(±2.2)%), and Erysiphe graminis (11a: 30.3(±1.8)%; 12d: 40.2(±0.9)%).CONCLUSIONCompounds 11a, 11b and 12d could be promising new lead structures for the development and discovery of novel fungicides towards Physalospora piricola and Erysiphe graminis. The structure‐activity relationship (SAR) analysis provided useful guidance and new understanding for the design of novel pyridylpyrazole‐containing agrochemicals. © 2019 Society of Chemical Industry
Relativistic calculations of AuSi+ and AuSi−
Authors: Barysz Maria , Černušák Ivan , Kellö Vladimir 
Published: April 2019

AbstractTheoretical calculations of the electronic structure of the ground state and a series of excited states of the AuSi+ and AuSi− molecules are presented. The calculations were carried out with the spin‐free relativistic infinite‐order two‐component (IOTC) method and high‐level complete active space self‐consistent field/complete active space perturbation theory correlated methods. The spin‐orbit (SO) coupling was introduced via the restricted active space state interaction method with the use of the atomic mean‐field SO integrals. The work presents the spectroscopic parameters of calculated states and full potential energy curves of the ionic AuSi+ and AuSi− structures for the first time. Electrostatic potential maps projected on the electron density surface illustrate the significant relativistic effects on going from nonrelativistic to scalar relativistic treatments.
Characterization of ethoxylated alcohols in friction reducers using matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry
Authors: York Jamie L. , Magnuson Robert H. , Camdzic Dino , Schug Kevin A. 
Published: April 2019

RationaleMatrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOF‐MS) provides detailed information for the analysis of ethoxylated alcohols and polymers. In this study, five friction reducers used in commercial hydraulic fracturing processes were analyzed in their as‐received form to identify their ethoxylated alcohol content. The friction reducers were then subjected to lab‐simulated downhole conditions. Characterization of friction reducers before and after being subjected to reactive conditions can provide fingerprints associated with produced oilfield waste for source apportionment and information on the stability of these key hydraulic fracturing additives.MethodsFive different industrially used friction reducers were analyzed for their ethoxylated alcohol content using MALDI‐TOF‐MS. Three different matrices were assessed for optimal response: α‐cyano‐4‐hydroxycinnamic acid, 2,5‐dihydroxybenzoic acid, and 2,5‐dihydroxybenzoic acid with 2,2,2‐trifluoroethanol (2,5‐DHB + E). Reaction times, temperatures, and sample matrices (deionized water, produced water inorganic, produced water, and produced water + shale core) were varied to assess changes in molecular weight distribution and polydispersity of the ethoxylated alcohols relative to their as‐received content.ResultsA preference for the 2,5‐DHB + E matrix was observed. The friction reducers were found to contain ethoxylated alcohols with carbon chain lengths of 12 and 14 with degrees of ethoxylation ranging from 6 to 18. Upon being subjected to 100°C for 24 hours, the ethoxylated alcohols tended to polymerize further, returning higher average molecular weights. Less polymerization was seen in more complex matrices, as supported by dispersity calculations.ConclusionsEthoxylated alcohol content was effectively determined in friction reducers using MALDI‐TOF‐MS. Although this is not a new technique to characterize ethoxylated alcohols, it has proven to be a quick and effective way to determine ethoxylated alcohol content in friction reducers in complex oilfield matrices. This technique can be used as a rapid and straightforward way to determine ethoxylated alcohol content in friction reducers and hydraulic fracturing wastewater for fingerprinting.
Frame synchronization for pulsed jammed satellite telecommand links
Authors: Noels Nele , Moeneclaey Marc 
Published: April 2019

SummaryA new issue of the satellite telecommand synchronization and channel coding sublayer protocol includes LDPC‐coded communication link transmission units (CLTUs) that contain a 64‐bit start sequence. The novel data structures allow operation at lower signal‐to‐noise ratios than before and offer improved protection against jamming attacks. This paper considers the corresponding CLTU frame synchronization process. We derive practical algorithms to locate the start sequence in the presence of high noise levels and pulsed jamming. The different algorithms are compared in terms of implementation complexity and performance under various jamming conditions. It is shown that among the considered frame synchronizers, those involving a full search over the entire observation window provide the desired accuracy, ie, they guarantee a frame synchronization error probability that is significantly smaller than the codeword error rate, for codeword error rates near a target value of 10−4. Among these synchronizers, the full‐search hard‐decision–directed correlation‐based algorithm has the lowest complexity.
Entrepreneurial firms grow up: Board undervaluation, board evolution, and firm performance in newly public firms
Authors: Garg Sam , John Li Qiang , Shaw Jason D. 
Published: April 2019

AbstractResearch SummaryAn initial public offering (IPO) ushers in many changes to the organization's boards of directors, including the installation of a formal and comprehensive board leadership structure. This paper shows that higher board undervaluation, that is, the average degree to which directors' qualifications based on normatively accepted criteria for board leadership are not duly reflected in their appointments to the board chair and committee chair positions, is associated with higher director turnover, and with lower qualifications among new directors in the subsequent years. Further, the effect of board undervaluation on firm performance is mediated both by director turnover and new directors' qualifications. But these two mediators operate as opposite forces on performance—director turnover is associated with lower firm performance, but counter‐intuitively lower new‐director‐qualifications are associated with higher firm performance.Managerial SummaryHow should a privately‐held entrepreneurial firm design its board leadership structure at IPO? What are the implications for board evolution and even firm performance? We find that higher board undervaluation, that is, the average degree to which directors' qualifications based on normatively accepted criteria for board leadership are not duly reflected in their appointments to the board chair and committee chair positions, is associated with higher director turnover, and with lower qualifications among new directors in the subsequent years. These two evolutionary paths act in opposite ways on performance—director turnover lowers firm performance, but lower new‐director‐qualifications improve firm performance. This has important implications for boards, investors, and stock exchange guidelines on board leadership structure.
Market reactions to non‐market strategy: Congressional testimony as an indicator of firm political influence
Authors: Ridge Jason W. , Ingram Amy , Abdurakhmonov Mirzokhidjon , Hasija Dinesh 
Published: April 2019

AbstractResearch SummaryWe argue that because influence in the political arena can net benefits for firms, investors will respond favorably to indications of firm political influence. We focus on testimony before Congress because it is one of the most highly sought after and influential points of governmental access. Our findings indicate that firms reap positive abnormal returns surrounding Congressional testimony and that investors respond more favorably to aspects of testimony that indicate additional political influence (i.e., witness status, testimony length, and committee jurisdiction). Further, we find regulatory risk strengthens the effect of witness status and testimony length while Congressional negativity strengthens the effect of witness status. Taken together, our results suggest that investors respond favorably to indications that firms have influence in the political arena.Managerial SummaryOur findings showcase that investors react positively to firm Congressional testimonies and their attributes, such as the status of a firm representative, the length of the testimony, and the committee industry jurisdiction. Further, we also find that investors will respond even more positively to these Congressional testimony attributes when a firm is facing high regulatory risk and when the Congressional representative's tone is negative. In general, our findings suggest that firms may gain market returns through obtaining public access to Congressional committees.
The impact of feature types, classifiers, and data balancing techniques on software vulnerability prediction models
Authors: Kaya Aydin , Keceli Ali Seydi , Catal Cagatay , Tekinerdogan Bedir 
Published: April 2019

AbstractSoftware vulnerabilities form an increasing security risk for software systems, that might be exploited to attack and harm the system. Some of the security vulnerabilities can be detected by static analysis tools and penetration testing, but usually, these suffer from relatively high false positive rates. Software vulnerability prediction (SVP) models can be used to categorize software components into vulnerable and neutral components before the software testing phase and likewise increase the efficiency and effectiveness of the overall verification process. The performance of a vulnerability prediction model is usually affected by the adopted classification algorithm, the adopted features, and data balancing approaches. In this study, we empirically investigate the effect of these factors on the performance of SVP models. Our experiments consist of four data balancing methods, seven classification algorithms, and three feature types. The experimental results show that data balancing methods are effective for highly unbalanced datasets, text‐based features are more useful, and ensemble‐based classifiers provide mostly better results. For smaller datasets, Random Forest algorithm provides the best performance and for the larger datasets, RusboostTree achieves better performance.
Boundary objects and their use in agile systems engineering
Authors: Wohlrab Rebekka , Pelliccione Patrizio , Knauss Eric , Larsson Mats 
Published: April 2019

SummaryAgile methods are increasingly introduced in automotive companies in the attempt to become more efficient and flexible in the system development. The adoption of agile practices influences communication between stakeholders and makes companies rethink the management of artifacts and documentation like requirements, safety compliance documents, and architecture models. Practitioners aim to reduce irrelevant documentation but face a lack of guidance to determine what artifacts are needed and how they should be managed. This paper presents artifacts, challenges, guidelines, and practices for the continuous management of systems engineering artifacts in automotive based on a theoretical and empirical understanding of the topic. In collaboration with 53 practitioners from six automotive companies, we conducted a design‐science study involving interviews, a questionnaire, focus groups, and practical data analysis of a systems engineering tool. The guidelines suggest the distinction between artifacts that are shared among different actors in a company (boundary objects) and those that are used within a team (locally relevant artifacts). We propose an analysis approach to identify boundary objects and three practices to manage systems engineering artifacts in industry.
Association between impedance to blood flow in umbilical arteries and infant survival in twin‐to‐twin transfusion syndrome
Authors: Espinoza A. F. , Belfort M. A. , Shamshirsaz A. A. , Hudson K. M. , Parisi X. , Nassr A. A. , Sanz Cortes M. , Erfani H. , Espinoza J. 
Published: April 2019

ABSTRACTObjectiveTo evaluate infant survival according to the Doppler pattern of impedance to blood flow in the umbilical arteries (UAs) prior to laser surgery, in pregnancies with twin‐to‐twin transfusion syndrome (TTTS).MethodsThis was a retrospective study of women with a monochorionic diamniotic twin pregnancy who underwent laser surgery for TTTS between January 2012 and May 2018 at a single institution. Absolute intertwin difference in UA pulsatility index (DUAPI) was measured within 48 h prior to laser surgery. Twins with intermittent or persistent absent/reversed end‐diastolic flow (EDF) in the UA (UA‐EDF) were analyzed separately. Survival of both or at least one infant at birth and at 30 days postpartum was compared between pregnancies with an intertwin DUAPI of ≥ 0.4 and those with an intertwin DUAPI of < 0.4, as well as between fetuses with intermittent and those with persistent absent/reversed UA‐EDF. Parametric and non‐parametric tests were used for analysis. Regression analysis was performed to determine if intertwin DUAPI and intermittent or persistent absent/reversed UA‐EDF were associated independently with infant survival, while controlling for gestational age at delivery, Quintero stage and other important confounding variables.ResultsOf 231 TTTS pregnancies that underwent laser surgery during the study period, UA Doppler information could be retrieved for 206 and delivery information was available for 184, which comprised the study population. Rates of double‐twin survival at birth were significantly higher in pregnancies with an intertwin DUAPI of < 0.4 than in those with an intertwin DUAPI of ≥ 0.4 (83.9% (78/93) vs 50.0% (12/24); P < 0.001). Double‐infant survival at birth was higher in pregnancies with intermittent compared to those with persistent absent/reversed UA‐EDF (73.0% (27/37) vs 36.7% (11/30); P = 0.003). Regression analysis demonstrated that an intertwin DUAPI of < 0.4 was associated with increased survival of both twins at delivery (P < 0.001) and at 30 days postpartum (P = 0.002), as well as increased survival of at least one twin at delivery (P = 0.009). Similarly, intermittent absent/reversed UA‐EDF was associated with increased survival of both twins at delivery (P = 0.007) and at 30 days after birth (P = 0.015).ConclusionsEvaluation of intertwin differences in UA impedance to blood flow as well as identification
of intermittent or persistent absent or reversed UA‐EDF prior to laser surgery could help in the prediction of double‐infant survival at birth and to 30 days in twin pregnancies with TTTS. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.
Subleading power rapidity divergences and power corrections for qT
Authors: Ebert Markus A. , Moult Ian , Stewart Iain W. , Tackmann Frank J. , Vita Gherardo , Zhu Hua Xing 
Published: April 2019

AbstractA number of important observables exhibit logarithms in their perturbative description that are induced by emissions at widely separated rapidities. These include transverse-momentum (qT) logarithms, logarithms involving heavy-quark or electroweak gauge boson masses, and small-xlogarithms. In this paper, we initiate the study of rapidity logarithms, and the associated rapidity divergences, at subleading order in the power expansion. This is accomplished using the soft collinear effective theory (SCET). We discuss the structure of subleading-power rapidity divergences and how to consistently regulate them. We introduce a new pure rapidity regulator and a corresponding$$ \overline{\mathrm{MS}} $$MS¯-like scheme, which handles rapidity divergences while maintaining the homogeneity of the power expansion. We find that power-law rapidity divergences appear at subleading power, which give rise to derivatives of parton distribution functions. As a concrete example, we consider theqTspectrum for color-singlet production, for which we compute the completeqT2/Q2suppressed power corrections at$$ \mathcal{O}\left({\alpha}_s\right) $$Oαs, including both logarithmic and nonlogarithmic terms. Our results also represent an important first step towards carrying out a resummation of subleading-power rapidity logarithms.
Finite quark-mass effects in Higgs boson production with dijets at large energies
Authors: Andersen Jeppe R. , Cockburn James D. , Heil Marian , Maier Andreas , Smillie Jennifer M. 
Published: April 2019

Abstract

The production of a Higgs boson in association with at least two jets receives contributions both from the fusion of weak vector bosons (VBF) and from QCD processes, especially gluon fusion (GF). The former process is important for measuring the coupling of the Higgs boson to weak bosons, whereas the latter process plays an important role in determining any CP-admixtures in the Higgs sector. In this paper we go beyond the current state-of-the-art for fixed order calculations of the GF process (i.e. one loop H + 2j including full quark mass effects) by including the all-order effects in leading log(ŝ/p

t

2
), together with full quark mass and loop-propagator kinematic effects. We calculate the mass-dependent components and implement the resummation within the framework of High Energy Jets.
The high-energy effects suppress the prediction compared to fixed order at large Δy
12 and m

jj
(and therefore within the usual VBF cuts of widely separated jets), just as found in the limit of m

t
→ ∞. The mass dependence is more significant than at fixed order, because the systematic inclusion of the leading logarithms in ŝ/p

t

2
results in a hardening of the transverse momentum of the Higgs boson, which in turn probes in more detail the loop-structure of the coupling. In particular, the full mass dependence reduces the cross section within VBF cuts by 11% compared to a calculation based just on the infinite top mass limit, but the impact of the bottom quark remains small. This all implies that the gluon-fusion contribution within VBF-cuts is less severe than current estimates suggest.