bluuebunny/crossref_metadata_2025 huggingface dataset:
The relationship management function of public affairs officers in Chile: Identifying opportunities and challenges in an emergent market
Authors: Labarca Claudia , Arceneaux Phillip C. , Golan Guy J.
Published: February 2020

Research on the public affairs profession in both South and Latin America is one of the leading limitations today in international public relations research. This study helps to lessen such a gap by offering more realistic insight into the ideologies and pressures that govern public affairs practice in Chile. In‐depth interviews were conducted with 15 experts who are current senior‐level public affairs practitioners in the Chilean capital of Santiago. Results offer three key insights: First, the core function of public affairs in Chile surrounds behaviors of lobbying and governmental relations. Second, leveraging cohesion between organizational private interest and the public interest is a key to leveraging pressure on elected officials and governmental agencies. Lastly, there is significant concern regarding public trust in the lack of transparency in the Chilean public affairs field, facilitated by insufficient governmental regulation. Such research offers practical and grounded insights for public affairs and public relations scholarship.
Appraisal of ε‐Caprolactam and Trimellitic Anhydride Potential as Novel Chain Extenders for Poly(lactic acid)
Authors: Mayouf Imane , Guessoum Melia , Fuensanta Mónica , Martín Martìnez José Miguel
Published: February 2020

The potential of ε‐caprolactam (CAP) and trimellitic anhydride (TMA) compounds as novel chain extenders for poly(lactic acid) (PLA) has been assessed; the amounts of 0.01, 0.025, and 0.05 wt% each additive have been added. The chain extension was evidenced by the increase in PLA/CAP and PLA/TMA viscosities in mixing torque measurements and by infrared spectroscopy. PLA reaction with CAP and TMA has also been confirmed from contact angle and surface free energy studies, which have shown that the increase in TMA amount decreased the hydrophilicity of PLA due to the decreased concentration of terminal surface hydroxyl groups. However, the addition of CAP accentuated the PLA hydrophilicity as indicated by the increase in the polar component of the surface energy. On the other hand, the glass transition temperature of PLA/TMA and PLA/CAP decreased as a result of a local plasticizing effect, which favored the chain mobility and the crystallization of PLA due to the concomitant nucleating effect of the chain extenders moieties too. Furthermore, the higher molecular weight of PLA/CAP and PLA/TMA was responsible for their increased thermal stability and higher impact strength with respect to PLA. POLYM. ENG. SCI., 60:944–955, 2020. © 2020 Society of Plastics Engineers
Dielectric Relaxation Dynamics of Clay‐Containing Low‐Density polyethylene Blends and Nanocomposites
Authors: Eesaee Mostafa , David Eric , Demarquette Nicole R.
Published: February 2020

Series of clay‐containing nanocomposites have been prepared and investigated using frequency‐domain dielectric spectroscopy at different temperatures. Different matrix materials have been used: neat low‐density polyethylene (LDPE) with and without compatibilizer and co‐continuous blends of LDPE with two grades of polystyrene‐b‐poly(ethylene‐co‐butylene)‐b‐polystyrene (SEBS) copolymers. Two major relaxation modes were detected in the dielectric losses of all the nanocomposites and associated with Maxwell–Wagner–Sillars interfacial polarization and dipolar relaxation, respectively. Characteristic relaxation rates, activation energies, dielectric strength, and shape parameters of these relaxation mechanismes were calculated and discussed for the LDPE/clay nanocomposites. The addition of compatibilizer was found to slightly increase the dielectric loss of the nanocomposites while slowing the dynamics due to an improved dispersion. When combined with a high loading of nanofiller (15%), the compatibilizer addition led to low‐frequency dispersion. A new relaxation process was then observed for the nanocomposites with the blend matrix. Several speculations were made as to the origin of this phenomenon, all of which were related to the SEBS phase. POLYM. ENG. SCI., 60:968–978, 2020. © 2020 Society of Plastics Engineers
Evaluating the cost‐effectiveness of the Dyslexia Pilot Project: A multitiered system of supports for early literacy
Authors: Morrison Julie Q. , Hawkins Renee O. , Collins Tai A.
Published: February 2020

The Dyslexia Pilot Project provided funding to school districts to implement a multitiered system of support (MTSS) framework for the prevention, early identification, and early intervention of reading difficulties. This article describes the evaluation of the multiyear Dyslexia Pilot Project for students in kindergarten through Grade 2. The evaluation extended a conceptual model for evaluating the systems effects of an MTSS for reading by including a cost‐effectiveness analysis. The results indicate that mean rates of improvement on Dynamic Indicators for Basic Early Literacy Skills Next curriculum‐based measures for students in participating schools exceeded the expected rates of improvement based on benchmark norms. This reduction in risk precluded the need for more intensive, individualized, and costly interventions and specialized educational services. Implications of the findings and future directions are discussed.
A phase 3 study evaluating the safety and efficacy of a pediatric dose of mometasone furoate with and without formoterol for persistent asthma
Authors: Weinstein Cindy L. J. , Gates Davis , Zhang Xiaoli , Varnell Tracey , Mok Wilson , Vermeulen Jan H. , Amar Niran J. , Jain Neal
Published: February 2020

Objectives

Asthma affects over 6 million children in the United States alone. This study investigated the efficacy and long‐term safety of mometasone furoate‐formoterol (MF/F) and MF monotherapy in children with asthma.

Materials and Methods

This phase 3, multicenter, randomized controlled trial evaluated metered‐dose inhaler twice daily (BID) dosing with MF/F 100/10 µg or MF 100 µg in children, aged 5 to 11 years, with a history of asthma for greater than or equal to 6 months and confirmed bronchodilator reversibility, who were adequately controlled on inhaled corticosteroid/long‐acting beta‐agonist combination therapy for greater than or equal to 4 weeks. After a 2‐week run‐in on MF 100 µg BID, eligible patients received 24 weeks of double‐blind treatment and were followed for safety up to 26 weeks. The primary efficacy endpoint was the change from baseline in AM postdose 60‐minute AUC %predicted FEV1% across 12 weeks of treatment.

Results

A total of 181 participants received at least one dose of MF/F (n = 91) or MF (n = 90). MF/F was superior to MF across the 12‐week evaluation period, with a treatment advantage of 5.21 percentage points (P < .001). Superior onset of action with MF/F over MF was achieved as early as 5 minutes postdose on day 1. Overall, approximately 50% of participants experienced one or more treatment‐emergent adverse events, with fewer occurring in the MF/F group.

Conclusions

In children 5 to 11 years of age with persistent asthma, the addition of F to MF was well tolerated and provided significant, rapid, and sustained improvement in lung function compared with MF alone.
Antibody response against Pseudomonas aeruginosa and its relationship with immune mediators in the upper and lower airways of cystic fibrosis patients
Authors: Mauch Renan M. , Hentschel Julia , Aanaes Kasper , Barucha Anton , Nolasco da Silva Marcos T. , Levy Carlos E. , Høiby Niels , Mainz Jochen G.
Published: February 2020

Background

The upper airways (UAW) are a niche and a reservoir of Pseudomonas aeruginosa strains that cause chronic infection of the lower airways (LAW) in cystic fibrosis (CF). Here, we assessed the role of anti‐P. aeruginosa immunoglobulin A (IgA) and IgG antibodies in upper and lower airway infections in cystic fibrosis patients.

Methods

Nasal lavage fluid and induced sputum samples of 40 CF patients were microbiologically cultured. We searched for correlations between anti‐P. aeruginosa IgA and IgG levels, measured by enzyme‐linked immunosorbent assay (optical density), and unspecific immune mediators in both specimens.

Results

Anti‐P. aeruginosa IgA (median optical density: 0.953 vs 0.298) and IgG (0.120 vs 0.059) were significantly higher in nasal lavage than in sputum, but not significantly different between patients with and without chronic P. aeruginosa infection in UAW. Matrix metallopeptidase‐9 (MMP‐9) in nasal lavage and neutrophil elastase (NE) in sputum were predictors of IgA in nasal lavage and IgA in sputum, respectively. IgA was a predictor of myeloperoxidase (MPO) in nasal lavage. Tissue inhibitor of metalloproteinases‐1 (TIMP‐1) was a predictor of IgG in sputum. IgG, TIMP‐1, and NE in sputum were predictors of IgG in nasal lavage.

Conclusion

The anti‐P. aeruginosa IgA response was more prominent in CF patients' UAW, indicating a lower degree of inflammatory responses. Proteases may play a role in the anti‐P. aeruginosa humoral response in the upper and LAW, and anti‐P. aeruginosa IgG may be involved in the crosstalk between upper and lower airways in cystic fibrosis patients.
Synthesis and Properties of 3,6‐Dinitropyrazolo[4,3‐c]‐pyrazole (DNPP) Derivatives
Authors: Zhang Wenquan , Xia Honglei , Yu Rujing , Zhang Jiaheng , Wang Kangcai , Zhang Qinghua
Published: February 2020

A series of novel fused‐ring pyrazolo[4,3‐c]pyrazole derivatives featuring N‐dinitromethyl and N‐fluorodinitromethyl energetic groups (compounds 3–7) were synthesized using a nine‐step reaction. All these compounds were characterized using multinuclear nuclear magnetic resonance (NMR) spectroscopy, infra‐red (IR) spectroscopy, and elemental analysis. X‐ray diffraction analysis was performed, and the single‐crystal structures of compounds 3, 4, 6, and 7 were obtained. For these newly prepared energetic materials, the thermal stability was determined using differential scanning calorimetry (DSC), while the sensitivities were evaluated using BAM drop hammer and friction test. The calculated heat of formation values and the measured densities were used to determine the detonation parameters, including detonation velocity and pressure, using the EXPLO5 program. Of all the prepared compounds, dipotassium 1,4‐bis(dinitromethyl)‐3,6‐dinitro‐1,4‐dihydropyrazolo[4,3‐c]pyrazole (3) was crystallized as a three‐dimensional energetic metal‐organic framework (MOF) and showed outstanding detonation performances, which even outperformed the traditional primary explosive lead azide. Compound 7 exhibited a high crystal density of 1.939 g cm−3, the high decomposition temperature of 213 °C and desirable impact and friction sensitivities (IS: 12 J; FS: 240 N). These combined properties and performances make these novel fused‐ring energetic compounds suitable candidates for high‐performance energetic materials.
Bacterial secretins: Mechanisms of assembly and membrane targeting
Authors: Silva Yuri Rafael de Oliveira , Contreras‐Martel Carlos , Macheboeuf Pauline , Dessen Andréa
Published: February 2020

Secretion systems are employed by bacteria to transport macromolecules across membranes without compromising their integrities. Processes including virulence, colonization, and motility are highly dependent on the secretion of effector molecules toward the immediate cellular environment, and in some cases, into the host cytoplasm. In Type II and Type III secretion systems, as well as in Type IV pili, homomultimeric complexes known as secretins form large pores in the outer bacterial membrane, and the localization and assembly of such 1 MDa molecules often relies on pilotins or accessory proteins. Significant progress has been made toward understanding details of interactions between secretins and their partner proteins using approaches ranging from bacterial genetics to cryo electron microscopy. This review provides an overview of the mode of action of pilotins and accessory proteins for T2SS, T3SS, and T4PS secretins, highlighting recent near‐atomic resolution cryo‐EM secretin complex structures and underlining the importance of these interactions for secretin functionality.
What men want: Qualitative analysis of what men with prostate cancer (PCa) want to learn regarding genetic referral, counseling, and testing
Authors: Greenberg Samantha , Slager Stacey , Neil Brock O' , Cooney Kathleen , Maughan Benjamin , Stopa Nicole , Venne Vickie , Zickmund Susan , Colonna Sarah
Published: February 2020

Background

Guidelines have changed recently to include genetic counseling (GC) and/or genetic testing (GT) for all men with aggressive prostate cancer (PCa). This study aimed to identify what information men with PCa desire before and from GC.

Methods

Focus groups were conducted with men who have PCa. Audio recordings were analyzed for themes related to GT, the information they desired from health care providers, and implications for family members.

Results

Thirty‐seven men with PCa participated in seven focus groups. Nearly all men felt GT was beneficial and impactful for their family and themselves. Most men were unaware of the risks to female relatives associated with hereditary cancer. Participants discussed that genetics should be incorporated at an appropriate time of their diagnostic journey.

Conclusion

This study showed that men valued GC and GT for personal and familial implications, and often did not associate PCa genetics with risk for female relatives to develop cancer. Consideration should be given to the GC timing in regard to where men are in their treatment process. Providers referring patients can leverage patient motivations and utilize their relationship with the patient to determine the appropriate timing and personalize discussion with the patient regarding GC and GT.
Selected ion flow tube mass spectrometry analyses of isobaric compounds methanol and hydrazine in humid air
Authors: Shestivska Violetta , Kolivoška Viliam , Kubišta Jiří , Smith David , Španěl Patrik
Published: February 2020

Rationale

The volatile compounds generated by the electrochemical reduction of atmospheric carbon dioxide and nitrogen include isobaric methanol (CH3OH) and, potentially, hydrazine (N2H4). To achieve quantification of hydrazine molecules by selected ion flow tube mass spectrometry (SIFT‐MS), its reactions with H3O+, NO+ and O2+ reagent ions must be understood.

Methods

A SIFT study (using a SIFT‐MS instrument) was carried out to obtain rate coefficients and product ions for the reactions of H3O+, NO+ and O2+ reagent ions with N2H4 and CH3OH molecules present in the humid headspace of their aqueous solutions. Using the kinetics data obtained, solution headspace concentrations were determined for both compounds as a function of their liquid‐phase concentrations at 10, 20 and 35°C.

Results

Both compounds react with H3O+ ions via rapid proton transfer to produce CH3OH2+ and H5N2+ ions with the common m/z value of 33. It is revealed that NO+ rapidly transfers charge to N2H4 (rate coefficient k = 2.3 × 10−9 cm3 s−1) but only slowly associates with CH3OH (k2eff = 7.1 × 10−11 cm3 s−1). Thus, selective analysis can be achieved using both H3O+ and NO+ reagent ions. The headspace methanol vapour concentration was found to increase with increasing solution temperature, but that of hydrazine decreased with an associated increase of ammonia (NH3) as measured with O2+ reagent ions.

Conclusions

The isobaric compounds methanol and hydrazine can be separately analysed in real time by SIFT‐MS using H3O+ and NO+ reagent ions, even when they co‐occur in humid air. The evolution of hydrazine from aqueous solutions can be quantitatively monitored together with its decomposition at elevated temperatures.
Endoscopic ultrasound‐guided pleural biopsy in the hands of the pulmonologist
Authors: Bibi Rana , Bodtger Uffe , Nessar Rafi , Jensen Henrik K. , Skovgaard Christiansen Ida , Clementsen Paul F.
Published: February 2020

The use of the endobronchial ultrasound (EBUS) endoscope in the oesophagus, the so‐called EUS‐B procedure, for the diagnosis and staging of thoracic malignancy is quickly gaining ground. Pleural lesions located close to the oesophagus can be inaccessible to transthoracic biopsy and endoscopic procedures can be the only option. We here present two cases demonstrating that EUS‐B‐guided fine needle aspiration (EUS‐B‐FNA) of pleural lesions is possible. The first case demonstrates a EUS‐B‐FNA with malignant mesothelioma of a pleural lesion in a 70‐year‐old patient. In the second case, EUS‐B‐FNA diagnosed a pleural metastasis from adenoid cystic adenocarcinoma in a 75‐year‐old‐patient. In conclusion, we hereby demonstrate that EUS‐B‐FNA from pleural lesions is feasible and appears to be safe.
Evaluating a learning progression for the solar system: Progress along gravity and dynamical properties dimensions
Authors: Plummer Julia D. , Palma Christopher , Rubin KeriAnn , Flarend Alice , Ong Yann Shiou , Ghent Chrysta , Gleason Timothy , McDonald Scott , Botzer Brandon , Furman Tanya
Published: February 2020

We previously proposed a hypothetical learning progression around the disciplinary core idea of the Solar System and its formation as a first step in a research program to begin to fill this gap and address questions of student learning in this domain. In this study, we evaluate the effectiveness of two dimensions within the learning progression, dynamical properties and gravity, in describing change in how student reason in the domain across the course of their 14‐week astronomy unit. A sample of sixth‐grade students (N = 24) were interviewed before and after instruction. We compared changes in how students explained the dynamic properties of planets and the role of gravity in the Solar System to their experiences during instruction. Our findings provide evidence for the usefulness of this learning progression in describing how students' explanations may progress, offer insight into how instruction may support that progress, and highlight the challenges in drawing conclusions on how students' explanations may progress when limitations are identified in instructional experiences. We also discuss the connection between these two construct maps but also point out what appears to be a missing element in our original definition of the learning progression: inertia.
The repair and autophagy mechanisms of hypoxia-regulated bFGF-modified primary embryonic neural stem cells in spinal cord injury
Authors: Zhu Sipin , Chen Min , Deng Liancheng , Zhang Jinjing , Ni Wenfei , Wang Xiangyang , Yao Felix , Li Xiaokun , Xu Huazi , Xu Jiake , Xiao Jian
Published: February 2020

There is no effective strategy for the treatment of spinal cord injury (SCI), a devastating condition characterized by severe hypoxia and ischemic insults. In this study, we investigated the histology and pathophysiology of the SCI milieu in a rat model and found that areas of hypoxia were unevenly interspersed in compressed SCI. With this new knowledge, we generated embryonic neural stem cells (NSCs) expressing basic fibroblast growth factor (bFGF) under the regulation of five hypoxia-responsive elements (5HRE) using a lentiviral vector (LV-5HRE-bFGF-NSCs) to specifically target these hypoxic loci. SCI models treated with bFGF expressed by the LV-5HRE-bFGF-NSCs viral vector demonstrated improved recovery, increased neuronal survival, and inhibited autophagy in spinal cord lesions in the rat model due to the reversal of hypoxic conditions at day 42 after injury. Furthermore, improved functional restoration of SCI with neuron regeneration was achieved in vivo, accompanied by glial scar inhibition and the evidence of axon regeneration across the scar boundary. This is the first study to illustrate the presence of hypoxic clusters throughout the injury site of compressed SCI and the first to show that the transplantation of LV-5HRE-bFGF-NSCs to target this hypoxic microenvironment enhanced the recovery of neurological function after SCI in rats; LV-5HRE-bFGF-NSCs may therefore be a good candidate to evaluate cellular SCI therapy in humans.

Significance statement The present study shows that application of hypoxia-regulated basic fibroblast growth factor modified primary embryonic neural stem cells to specifically target the hypoxic loci resulted in a reversal of the hypoxic microenvironment after spinal cord injury (SCI), concomitant with decreased cellular autophagy, reduced CNS glial scar formation, and improved locomotor function in in vivo studies. The results of the present study increase the current understanding of the pathophysiology of SCI and may be used to combat the ischemic microenvironment that can induce cell death and limit cell transplantation approaches to promote spinal cord regeneration.
Ordinal outcomes: A cumulative probability model with the log link and an assumption of proportionality
Authors: Singh Gurbakhshash , Hilton Fick Gordon
Published: February 2020

We present here a study of ordinal outcomes with a cumulative probability model. In particular, we consider the log link with the assumption of proportionality. The logit link is currently the most widely used link with ordinal outcomes in the health research literature. With the logit link, one obtains regression coefficients that are functions of odds. When the log link is used, one obtains regression coefficients that are functions of probabilities. While odds might be preferred with certain studies that are retrospective, many health researchers may prefer to have direct statements about probabilities. There are two classes of models with the log link analogous to those with the logit link. We will call these two classes the Proportional Probability Model (PPM) and the Log Cumulative Probability Model (LCPM). These models introduce a challenge not seen with the logit link models. The log link models have constraints on the parameter space. We must insist that the maximum likelihood estimate (MLE) satisfy these constraints. We present conditions for the uniqueness of the MLE and we present other features of the MLE. Several examples and several closed form expressions for the MLE are presented. While this paper is primarily about the PPM, our R packagelcpmcontains functions to fit both the PPM and the LCPM.
Facile One‐pot Synthesis of Arylsulfonyl‐4H‐pyrans Catalyzed by Ru Loaded Fluorapatite
Authors: Maddila Surya N , Maddila Suresh , Kerru Nagaraju , Bhaskaruni Sandeep V. H. S. , Jonnalagadda Sreekantha B
Published: February 2020

We report a novel ecofriendly cascade reaction for the synthesis of arylsulfonyl‐4H‐pyran derivatives by a three component fusion reaction of chosen aldehyde, dimedone and phenylsulphonyl acetonitrile at room temperature using ruthenia doped fluorapatite (RuO2/FAp) as recyclable catalyst. Different percentages of RuO2/FAp materials were prepared and characterized by FT‐IR, P‐XRD, BET, SEM‐EDX and TEM analysis. Attractive features of the synthetic approach are operational simplicity, cost‐effectiveness, short reaction time and excellent yields. Easily recoverable and reusable catalyst material without any deceptive loss of catalytic activity up to seven cycles is additional benefit.
Synthesis and Characterization of Host Guest Inclusion Complexation of Cyclic Oligosaccharide with Industrially Potent Dye in Different Phases by Physicochemical Contrivance
Authors: Yasmin Ananya , Barman Biraj Kumar , Roy Niloy , Roy Mahendra Nath
Published: February 2020

The inclusion phenomena of β‐Cyclodextrin and Alizarin complexone was investigated by 1H NMR, 2D ROESY, UV‐Visible Spectroscopy, Fluorescence Spectroscopy, HRMS and SEM study. The change in chemical shift values in 1H NMR study established the possibility of interactions between the corresponding protons of β‐ Cyclodextrin and AC molecule, which was further confirmed by the appearance of cross peaks in 2D ROESY spectrum. The Job plot method gave the host‐guest stoitiometric ratio to be 1 : 1. The association constant and thermodynamic parameters like ΔH0, ΔS0 and ΔG0 were calculated from UV‐Visible spectroscopy. The experimental results showed, the fluorescence intensity of AC enhanced with increasing concentration of β‐ Cyclodextrin. The plot of 1/(F‐F0) against 1/[β‐ Cyclodextrin] gave a straight line indicating 1 : 1 stoichiometric ratio of the inclusion complex formed. In this inclusion process, the ΔG<0 value describes the process to be a spontaneous one.
Freestanding SnS Carbon Composite Nanofiber Material with Excellent Electrochemical Performance as Binder‐Free Negative Electrode for Lithium‐ion Batteries
Authors: Qi Yufeng , Liu Jifei , Dai Jianfeng , Shi Xiangyu , Zhu Xiaojun , Fu Bi , Dong Haiying , Zhao Wengao
Published: February 2020

Metal sulfide demonstrated sluggish ionic transport kinetics due to the low electronic conductively, resulting larger volume expansion and even pulverize electrode during Li+ insertion/deinsertion. In this study, freestanding SnS nanoflower@carbon nanofiber (SnS@CNF) was prepared by the sol‐gel electrospinning of hydrothermal synthesized SnS2 nanoflower and carbonization. When direct used SnS@CNF as a binder‐free negative electrode for LIB, it delivered specific capacity of 564.4 mAh g−1@0.3 C after 450 cycles, and high rate capacities of 595, 465, 354, 267, 200, 129, 74, and 484 mAh g−1 at the current densities of 0.064, 0.1, 0.3, 0.6, 1.0, 1.5, 2.0, and 0.1 mA g−1, respectively. Such excellent electrochemical performance is attributed to the nanostructured conductive CNF network not only can buffer volume expansion and prevents the aggregation of active material, but also improve Li+ migration rates during the discharge (4.47×10−7 cm2 s−1) and charge (2.73×10−6 cm2 s−1) process.
Atomically Dispersed Single Ni Site Catalysts for Nitrogen Reduction toward Electrochemical Ammonia Synthesis Using N2 and H2O
Authors: Mukherjee Shreya , Yang Xiaoxuan , Shan Weitao , Samarakoon Widitha , Karakalos Stavros , Cullen David A. , More Karren , Wang Maoyu , Feng Zhenxing , Wang Guofeng , Wu Gang
Published: February 2020

Ammonia (NH3) electrosynthesis gains significant attention as NH3 is essentially important for fertilizer production and fuel utilization. However, electrochemical nitrogen reduction reaction (NRR) remains a great challenge because of low activity and poor selectivity. Herein, a new class of atomically dispersed Ni site electrocatalyst is reported, which exhibits the optimal NH3 yield of 115 µg cm−2 h−1 at –0.8 V versus reversible hydrogen electrode (RHE) under neutral conditions. High faradic efficiency of 21 ± 1.9% is achieved at ‐0.2 V versus RHE under alkaline conditions, although the ammonia yield is lower. The Ni sites are stabilized with nitrogen, which is verified by advanced X‐ray absorption spectroscopy and electron microscopy. Density functional theory calculations provide insightful understanding on the possible structure of active sites, relevant reaction pathways, and confirm that the Ni‐N3 sites are responsible for the experimentally observed activity and selectivity. Extensive controls strongly suggest that the atomically dispersed NiN3 site‐rich catalyst provides more intrinsically active sites than those in N‐doped carbon, instead of possible environmental contamination. This work further indicates that single‐metal site catalysts with optimal nitrogen coordination is very promising for NRR and indeed improves the scaling relationship of transition metals.
Individual Competence and Committee Decision Making: Experimental Evidence
Authors: McCannon Bryan C. , Walker Paul
Published: February 2020

Committee decision making relies on the competence of its members. The individual's competence is driven by the pre‐meeting efforts. These investments constitute a public good and, consequently, free riding is a concern. We build off of previous theoretical results which point out that as committees grow in size, free riding becomes more severe. However, experimental and empirical research suggests that individuals are willing to make voluntary contributions. This motivation should lead to increased effort when the number who benefit increases. To differentiate between these hypotheses we explore experimentally the effect that changes in group size have on competence investment decisions in a committee setting. Decision problems differ by whether the expansion increases the number of voters on the committee or the number who are affected by the committee's decision. We find evidence supporting the hypothesis that as committees grow in size there is a reduction in effort invested. We find some evidence of an adverse reaction to non‐contributing beneficiaries is observed as well. Heterogeneous responses arise and are explored.
Synergistic Benefits of Cesium‐Doped Aqueous Precursor in Air‐Processed Inverted Perovskite Solar Cells
Authors: Wu Guangcheng , Sun Rui , Hu Linqun , Dong Xuting , Cui Guanglei , Gu Min , Tang Tong B. , Zuo Zewen , Liu Yong
Published: February 2020

Air‐processed perovskite solar cells (PSCs) allay the need for costly fabrication in a controlled atmosphere but currently suffer from disadvantages in power conversion efficiency (PCE) and device stability. Herein, the systematic investigation into CH3NH3PbI3–xClx prepared with an antisolvent‐assisted process in a relative humidity of 40 ± 5% is reported, using cesium‐containing aqueous solutions of various strengths. Diffractometry and microscopy reveal how grain sizes vary among the samples, suggesting an optimum concentration for grain size. Those films are fabricated in air into solar cells, and their electrochemical impedance and current–voltage characteristics under light are measured. The films demonstrating optimum strength achieve PCEs of up to 16.6%, compared with the maximum of 14.4% achieved by untreated films. The air‐processed films also exhibit mitigated hysteresis, with indices decreasing to 0.021. Photoluminescence characterization reveals reduced defect densities in Cs‐doped materials and, together with photoelectron spectroscopy, suggests an upward shift in energy bands. Such changes explain the improvement in photovoltaic performance. Stability tests on unencapsulated cells over 14 days show that those made from the perovskite with optimum Cs‐doping degrade slowest, with their conversion efficiencies falling by <10% every 100 h. Our findings may contribute to the low‐cost commercialization of PSCs.
Model‐based hypothesis testing of uncertain software systems
Authors: Camilli Matteo , Gargantini Angelo , Scandurra Patrizia
Published: February 2020

Nowadays, there exists an increasing demand for reliable software systems able to fulfill their requirements in different operational environments and to cope with uncertainty that can be introduced both at design‐time and at runtime because of the lack of control over third‐party system components and complex interactions among software, hardware infrastructures and physical phenomena. This article addresses the problem of the discrepancy between measured data at runtime and the design‐time formal specification by using aninverse uncertainty quantificationapproach. Namely, we introduce a methodology calledMETRICand its supporting toolchain to quantify and mitigate software system uncertainty during testing by combining (on‐the‐fly)model‐based testingandBayesian inference. Our approach connects probabilistic input/output conformance theory with statistical hypothesis testing in order to assess if the behaviour of the system under test corresponds to its probabilistic formal specification provided in terms of aMarkov decision process. An uncertainty‐aware model‐based test case generation strategy is used as a means to collect evidence from software components affected by sources of uncertainty. Test results serve as input to a Bayesian inference process that updates beliefs on model parameters encoding uncertain quality attributes of the system under test. This article describes our approach from both theoretical and practical perspectives. An extensive empirical evaluation activity has been conducted in order to assess the cost‐effectiveness of our approach. We show that, under same effort constraints, our uncertainty‐aware testing strategy increases the accuracy of the uncertainty quantification process up to 50 times with respect to traditional model‐based testing methods.
Thermochemistry Prediction and Automatic Reaction Mechanism Generation for Oxygenated Sulfur Systems: A Case Study of Dimethyl Sulfide Oxidation
Authors: Gillis Ryan J. , Green William H.
Published: February 2020

Automatic mechanism generation is a powerful approach to understanding complex chemical mechanisms. Here we describe the expansion of an open source mechanism creating software, the Reaction Mechanism Generator or RMG, to oxygenated sulfur systems. This principally involved the expansion of thermochemistry estimation techniques for higher valence oxygenated sulfur molecules. As a demonstration of this new tool, we present an automatically generated mechanism describing the oxidation of dimethyl sulfide. This mechanism is then compared to several experimental studies of dimethyl sulfide oxidation. This case study provides insight into the transformation of sulfur species in the atmosphere, especially the formation pathways of sulfoxides, sulfones, and sulfur dioxide. However, the applications of the newly enhanced mechanism generation tool extend far beyond this single system with obvious use in understanding a variety of atmospheric, petrochemical, and other industrial chemistries.
Random projections: Data perturbation for classification problems
Authors: Cannings Timothy I.
Published: February 2020

Random projections offer an appealing and flexible approach to a wide range of large‐scale statistical problems. They are particularly useful in high‐dimensional settings, where we have many covariates recorded for each observation. In classification problems, there are two general techniques using random projections. The first involves many projections in an ensemble—the idea here is to aggregate the results after applying different random projections, with the aim of achieving superior statistical accuracy. The second class of methods include hashing and sketching techniques, which are straightforward ways to reduce the complexity of a problem, perhaps therefore with a huge computational saving, while approximately preserving the statistical efficiency.

This article is categorized under:

Statistical Learning and Exploratory Methods of the Data Sciences > Clustering and Classification

Statistical and Graphical Methods of Data Analysis > Analysis of High Dimensional Data

Statistical Models > Classification Models
Diet of Ornate Hawk-Eagle (Spizaetus ornatus)
Authors: Teixeira Fagner Daniel , Mesquita Elisa Paraíso , Ferreira Michele Alves , de Araújo Felipe Carvalho
Published: February 2020

The Ornate Hawk-Eagle (Spizaetus ornatus) is a top predator and inhabits mainly preserved forests. It occurs from Mexico to Argentina and throughout Brazil, where it is threatened by extinction. It hunts birds, mammals and reptiles, picking up both on the ground and on the branches in the forest. Here we report data on a pair and one young individual of this species registered in the southeast of Minas Gerais state, eastern portion of the Espinhaço Range, Brazil. In addition, a literature review on the diet of the species was carried out aiming gather data on food habits. The nesting territory, as well as the nest was discovered in semi-deciduous seasonal forest area. We recorded predation of a Lesser Yellow-headed Vulture (Cathartes burrovianus) by the young. After two days of observation, the nest was overthrown, what allowed its screening for other food items discovered after analysis of some feathers and bones. Detailed records of predation ofS. ornatuswere non-existent or inaccurate. Taking together our own field observation and the literature review, we found 121 taxa consumed byS. ornatus. A total of 78 bird species were reported, mainly Galliformes, followed by medium-sized mammals (38 species), well represented by Rodentia and Primates.
Playful waterbird: Australasian Darter (Anhinga novaehollandiae) plays with sticks
Authors: Sazima Ivan
Published: February 2020

Play with objects by birds is recorded usually for nestlings and juveniles. This behaviour is regarded as important for motor development and practice of essential skills, mostly foraging and breeding. Play is recorded for the Anhinga (Anhinga anhinga) in North America. For the remaining three recognised species play with objects seems unreported. Herein I present events of play with objects by a maturing individual of the Australasian Darter (Anhinga novaehollandiae) recorded at the urban area of Sydney, southeastern Australia. In one of the play events, the darter played with a stick it broke from a partly submerged tree it was resting on. In another event, the bird picked a floating pod, tossed it into the air and caught it again. As the Australasian Darter maturing individual possibly was a male, it could be practicing to gather sticks for nest construction, whereas playing with the pod is related to prey handling.
A comparison of bird communities in natural and revegetated grasslands in south Brazil
Authors: Becker Rafael Gustavo , Paise Gabriela , Pizo Marco Aurélio
Published: February 2020

Natural grasslands are declining due to loss, fragmentation and degradation, resulting in the decline of grassland-associated bird species. The Pampas Biome in south Brazil is not exception to this worldwide trend, facing the expansion of croplands and afforestation with exotic tree plantations for cellulose production. To cope with the continuous degradation and loss of grasslands, restoration is an important conservation strategy, but basic information regarding the response of the fauna to restoration practices in southeastern South America grasslands is lacking. Here we compared the structure of bird communities in natural grasslands and revegetated grasslands after mining by planting native and exotic grasses. We sampled birds using 5-min point counts with unlimited radius in three replicates of each habitat (natural and revegetated grasslands; average size 22.2 ± 2.3 ha). We also compared the vegetation density between the two habitat types. The structure of bird communities at natural and revegetated grasslands differed, with natural grasslands presenting higher species richness (42 vs. 35 species) and abundance (1459 vs. 839 records) than revegetated areas, and also a distinct species composition. Ten of the 11 grassland species that were associated to one of the two habitat types occurred more frequently in natural grasslands, which had higher vegetation density than revegetated areas. Even a decade after the beginning of the restoration process, revegetated areas did not resemble natural grasslands in bird species richness, abundance, and composition. These results differed from another study conducted in the Brazilian Pampas in which native plant species were used to actively restore a grassland. Therefore, until we have additional studies addressing the use of exotic grasses for the recovery of bird communities in South America grasslands, we encourage greater representation of native plant species in restoration projects.
Testing Macdonald index as a refined character of chiral algebra
Authors: Watanabe Akimi , Zhu Rui-Dong
Published: February 2020

Abstract

We test in (An−1, Am−1) Argyres-Douglas theories with gcd(n, m) = 1 the proposal of Song’s in [1] that the Macdonald index gives a refined character of the dual chiral algebra. In particular, we extend the analysis to higher rank theories and Macdonald indices with surface operator, via the TQFT picture and Gaiotto-Rastelli-Razamat’s Higgsing method. We establish the prescription for refined characters in higher rank minimal models from the dual (An−1, Am−1) theories in the large m limit, and then provide evidence for Song’s proposal to hold (at least) in some simple modules (including the vacuum module) at finite m. We also discuss some observed mismatch in our approach for surface operators with large vortex number.
Gauge-flavon unification
Authors: Aranda Alfredo , de Anda Francisco J. , King Stephen F.
Published: February 2020

Abstract

In this paper we propose the idea that flavons can emerge from extra dimensional gauge fields, referred to as gauge-flavon unification (GFU) analogous to gauge-Higgs unification (GHU). We assume that there is a gauged family symmetry in extra dimensions and that the flavons are the extra dimensional components of the gauge field. This provides a simple mechanism to align the VEVs of the flavons through a combination of Wilson lines and orbifold symmetry breaking. We present some simple 5d examples of GFU based on SO(3) and SU(4) gauged family symmetry, the latter case yielding SU(3) × U(1) gauged family symmetry in 4d, broken by triplet and antitriplet flavons, with effective couplings to fermions. We also present a general formalism for Wilson lines and orbifolds, in any number of dimensions, including non-commutative aspects Wilson lines, which may be useful for aligning additional flavons as required for realistic models.
Expectation values of coherent states for SU(2) Lattice Gauge Theories
Authors: Liegener Klaus , Zwicknagel Ernst-Albrecht
Published: February 2020

Abstract

This article investigates properties of semiclassical Gauge Field Theory Coherent States for general quantum gauge theories. Useful, e.g., for the canonical formulation of Lattice Gauge Theories these states are labelled by a point in the classical phase space and constructed such that the expectation values of the canonical operators are sharply peaked on said phase space point. For the case of the non-abelian gauge group SU(2), we will explicitly compute the expectation value of general polynomials including the first order quantum corrections. This allows asking more precise questions about the quantum fluctuations of any given semiclassical system.
Anwendungsszenarien und Technologiebewertung von digitalen Werkerassistenzsystemen in der Produktion – Ergebnisse einer Interview-Studie mit Experten aus der Wissenschaft, der Politik und der betrieblichen Praxis
Authors: Blumberg Verena Simone Lore , Kauffeld Simone
Published: February 2020

Die Einführung neuer digitaler Technologien wie digitale Werkerassistenzsysteme (z. B. Datenbrillen und Tablets) im Produktionsbereich führen zu Veränderungen der Arbeitswelt. Bestehende Modelle der Arbeitsgestaltung betrachten Technologien als Antezedenzien für die Arbeitsgestaltung. Die Theorie der sozialen Gestaltung von Technologien nimmt an, dass unterschiedliche Akteure Einfluss auf die Gestaltung und Verbreitung von Technologien im betrieblichen Kontext nehmen. Bisher ist kaum bekannt, welche Erwartungen unterschiedliche Akteure an die Anwendung und Gestaltung digitaler Werkerassistenzsysteme stellen. Ziel dieses Beitrags der Zeitschrift Gruppe. Interaktion. Organisation. (GIO) ist es, die Sichtweisen relevanter Akteure im Technologieentwicklungsprozess zu erfassen und basierende darauf Handlungs- und Gestaltungsempfehlungen für den Einsatz digitaler Werkerassistenzsysteme in der betrieblichen Praxis zu geben. Hierfür wurden 76 halbstrukturierte Interviews mit Wissenschaftlern, politischen Akteuren und betrieblichen Praktikern durchgeführt und inhaltsanalytisch ausgewertet. Als Ergebnis dieser Studie ist ein Kategoriensystem für die Einteilung von Anwendungsmöglichkeiten digitaler Werkerassistenzsysteme in der Produktion entstanden, das einen Ausgangspunkt für betriebliche Entscheidungsprozesse bei der Technologieeinführung darstellen kann. Die identifizierten Chancen und Risiken beim Einsatz von digitalen Werkerassistenzsystemen stellen Ansatzpunkte für die Technologiegestaltung und die Technologieimplementierung im Unternehmen bereit.
Role of the porphyrins and demulsifiers in the aggregation process of asphaltenes at water/oil interfaces under desalting conditions: a molecular dynamics study
Authors: Santos Silva H. , Alfarra A. , Vallverdu G. , Bégué D. , Bouyssiere B. , Baraille I.
Published: February 2020

Breaking water-in-oil emulsions during the refining of crude oils is an important step before any upgrading process is started. Asphaltene molecules are incriminated as playing an important role in this phenomenon. Unraveling the mechanisms behind the affinity between them and water is a key step to understand how to break these emulsions more easily and require lower amounts of demulsifiers. Choosing which demulsifier molecule(s) to use is also primordial, but to do so rationally, one needs to know which are the molecular interactions in place between asphaltenes, porphyrins and water so that demulsifiers are chosen to destabilize a specific physical–chemical interaction. In this paper, we study the interactions arising between asphaltenes and porphyrins and six different molecules potentially displaying a demulsification action in the presence of water/oil interfaces. We demonstrate that the ionic demulsifier molecules present an interesting potential to either interact strongly with water, replacing asphaltenes in this interaction, or to interact with the active sites of asphaltenes, deactivating them and avoiding any asphaltenic interfacial activity. Finally, we also found that although asphaltenes do not migrate spontaneously toward the water/oil interfaces, porphyrins do so rather easily. This indicates that porphyrins do have an important activity at the water/oil interface.
The Biological Structure Model Archive (BSM-Arc): an archive for in silico models and simulations
Authors: Bekker Gert-Jan , Kawabata Takeshi , Kurisu Genji
Published: February 2020

We present the Biological Structure Model Archive (BSM-Arc, https://bsma.pdbj.org), which aims to collect raw data obtained via in silico methods related to structural biology, such as computationally modeled 3D structures and molecular dynamics trajectories. Since BSM-Arc does not enforce a specific data format for the raw data, depositors are free to upload their data without any prior conversion. Besides uploading raw data, BSM-Arc enables depositors to annotate their data with additional explanations and figures. Furthermore, via our WebGL-based molecular viewer Molmil, it is possible to recreate 3D scenes as shown in the corresponding scientific article in an interactive manner. To submit a new entry, depositors require an ORCID ID to login, and to finally publish the data, an accompanying peer-reviewed paper describing the work must be associated with the entry. Submitting their data enables researchers to not only have an external backup but also provide an opportunity to promote their work via an interactive platform and to provide third-party researchers access to their raw data.
Normally Grown Non-dysmorphic Stillbirth Post 38 Weeks Gestation and Reduced Fetal Movements: A Matter of Reserve? A Retrospective Study
Authors: Campbell Jamie , Evans Margaret J.
Published: February 2020

This study investigates the relationship between placental weight relative to birthweight and risk of stillbirth in non-dysmorphic fetuses ≥ 38 weeks gestation with no evidence of intrauterine growth restriction. This is a retrospective study of stillbirths who underwent post-mortem between 1st Jan 2011 and 31st Dec 2018 in South East Scotland (n = 55). The control group (n = 74) was matched for gestation, age of mother and maternal BMI. There was a significant difference (p = 0.0117) in the mean ratio of birth weight to placental weight (BW:PW) between the stillbirth group (8.17) and control group (7.33). Cases of stillbirths where the mother had reported reduced fetal movements (RFM) had a higher BW:PW compared to controls (p = 0.024). Within the RFM stillbirth group, 5/6 (83%) cases showed significant changes of maternal vascular malperfusion (MVM) and/or fetal vascular malperfusion (FVM); whilst within the RFM control group, 5/15 (33%) cases showed significant changes of MVM and/or FVM. There is a significantly higher BW:PW within the stillbirth group than within the control group, both groups show changes of MVM and/or FVM and our supposition is that these changes have a greater impact on placental reserve when the birthweight is high relative to placental weight. Reduced fetal movements may indicate diminished placental reserve. We propose that the ability to predict a high BW:PW within pregnancies where the mothers report RFM may help to prevent late stillbirth in non-IUGR infants.