bluuebunny/crossref_metadata_2025 huggingface dataset:
A NEW APPROACH TO SELECT THE BEST SUBSET OF PREDICTORS IN LINEAR REGRESSION MODELLING: BI-OBJECTIVE MIXED INTEGER LINEAR PROGRAMMING
Authors: CHARKHGARD HADI , ESHRAGH ALI
Published: January 2019

We study the problem of choosing the best subset of$p$features in linear regression, given$n$observations. This problem naturally contains two objective functions including minimizing the amount of bias and minimizing the number of predictors. The existing approaches transform the problem into a single-objective optimization problem. We explain the main weaknesses of existing approaches and, to overcome their drawbacks, we propose a bi-objective mixed integer linear programming approach. A computational study shows the efficacy of the proposed approach.
Sensitivity of EMIC Wave‐Driven Scattering Loss of Ring Current Protons to Wave Normal Angle Distribution
Authors: Cao Xing , Ni Binbin , Summers Danny , Shprits Yuri Y. , Gu Xudong , Fu Song , Lou Yuequn , Zhang Yang , Ma Xin , Zhang Wenxun , Huang He , Yi Juan
Published: January 2019

Electromagnetic ion cyclotron waves have long been recognized to play a crucial role in the dynamic loss of ring current protons. While the field‐aligned propagation approximation of electromagnetic ion cyclotron waves was widely used to quantify the scattering loss of ring current protons, in this study, we find that the wave normal distribution strongly affects the pitch angle scattering efficiency of protons. Increase of peak normal angle or angular width can considerably reduce the scattering rates of ≤10 keV protons. For >10 keV protons, the field‐aligned propagation approximation results in a pronounced underestimate of the scattering of intermediate equatorial pitch angle protons and overestimates the scattering of high equatorial pitch angle protons by orders of magnitude. Our results suggest that the wave normal distribution of electromagnetic ion cyclotron waves plays an important role in the pitch angle evolution and scattering loss of ring current protons and should be incorporated in future global modeling of ring current dynamics.
A Statistical Study of EMIC Waves Associated With and Without Energetic Particle Injection From the Magnetotail
Authors: Jun C.‐W. , Yue C. , Bortnik J. , Lyons L. R. , Nishimura Y. , Kletzing C. , Wygant J. , Spence H.
Published: January 2019

To understand the relationship between generation of electromagnetic ion cyclotron (EMIC) waves and energetic particle injections, we performed a statistical study of EMIC waves associated with and without injections based on the Van Allen Probes (Radiation Belt Storm Probes) and Geostationary Operational Environmental Satellite (GOES; GOES‐13 and GOES‐15) observations. Using 47 months of observations, we identified wave events seen by the Van Allen Probes relative to the plasmapause and to energetic particle injections seen by GOES‐13 and GOES‐15 on the nightside. We separated the events into four categories: EMIC waves with (without) injections inside (outside) the plasmasphere. We found that He+ EMIC waves have higher occurrence rate inside the plasmasphere, while H+ EMIC waves predominantly occur outside the plasmasphere. Meanwhile, the time duration and peak occurrence rate of EMIC waves associated with injections are shorter and limited to a narrower magnetic local time region than those without injections, indicating that these waves have localized source regions. He+ EMIC waves inside the plasmasphere associated with injection are usually accompanied by an increase in H+ flux within energies of 1–50 keV through all magnetic local time regions, while most wave events outside the plasmasphere show less relationship with H+ flux increase. From these observations, we suggest that injected hot ions are the major driver of He+ EMIC waves inside the plasmasphere during active time. Expanding plasmasphere during quiet times can provide broad wave source regions for He+ EMIC waves on the dayside. However, H+ EMIC waves outside the plasmasphere show different characteristics, suggesting that these waves are generated by other processes.
Modeling of Unilateral Rupture Along Very Long Reverse Faults
Authors: Hirano Shiro
Published: January 2019

We evaluate the mechanism for horizontal unilateral rupture frequently observed along very long reverse faults in subduction zones or inland regions using mathematical models and numerical experiments. We consider a situation where the direction of maximum shear stress acting on the fault surface is not parallel to the fault plane. Furthermore, by incorporating the effects of the bimaterial interface and off‐fault inelastic deformation into the model, we demonstrate that acceleration of dynamic rupture in only one direction is possible. The mathematical modeling reveals that the asymmetric rupture is due to the asymmetric off‐fault damage interacting with asymmetric off‐fault stress intensity driven by the above effects. Finally, for three oblique subduction zones, we found that the rupture patterns of 8 of 11 megathrust events were consistent with the mechanism proposed in this study.
Energy Partitioning During Subcritical Mode I Crack Propagation Through a Heterogeneous Interface
Authors: Jestin Camille , Lengliné Olivier , Schmittbuhl Jean
Published: January 2019

The energy budget during the propagation of tensile fractures typically includes two major energy dissipation modes: the fracture energy to create a new interface and the radiated energy. Since seismic hazard is related to the amount of seismic energy released, it is important to evaluate precisely the energy budget during fracture propagation and see in particular if it is constant or not. However, two aspects are typically limiting a precise estimate of the energy budget: first, the measurement of the nonseismic energy release and second, the rock heterogeneity‐like asperities or barriers. We conducted here laboratory experiments, using an analog material (Polymethyl methacrylate (PMMA)), of a stable mode I interfacial crack propagation close to brittle‐creep transition through a heterogeneous interface for different macroscopic rupture velocities to evaluate carefully their energy budget. Both acoustic and optical advances of the crack front were measured simultaneously, providing precise estimates of both types of dissipated energy. We computed the radiation efficiency ηR (ratio of the radiated energy to the available energy for driving the fracture) and observed a nonlinear increase of ηR with the average fracture propagation velocity v over 2 orders of magnitude independently of the initial quenched disorder. The experimental observations are supported by a model based on the fluctuations of the local rupture velocity induced by the crack front pinning on local asperities which leads to ηR ∝ v0.55. We discuss implications for slow shear rupture modes, seismicity rate evolution, and induced seismicity.
Anomalous scaling of flexural phonon damping in nanoresonators with confined fluid
Authors: De Subhadeep , Aluru Narayana R.
Published: January 2019

Various one and two-dimensional (1D and 2D) nanomaterials and their combinations are emerging as next-generation sensors because of their unique opto-electro-mechanical properties accompanied by large surface-to-volume ratio and high quality factor. Though numerous studies have demonstrated an unparalleled sensitivity of these materials as resonant nanomechanical sensors under vacuum isolation, an assessment of their performance in the presence of an interacting medium like fluid environment is scarce. Here, we report the mechanical damping behavior of a 1D single-walled carbon nanotube (SWCNT) resonator operating in the fundamental flexural mode and interacting with a fluid environment, where the fluid is placed either inside or outside of the SWCNT. A scaling study of dissipation shows an anomalous behavior in case of interior fluid where the dissipation is found to be extremely low and scaling inversely with the fluid density. Analyzing the sources of dissipation reveals that (i) the phonon dissipation remains unaltered with fluid density and (ii) the anomalous dissipation scaling in the fluid interior case is solely a characteristic of the fluid response under confinement. Using linear response theory, we construct a fluid damping kernel which characterizes the hydrodynamic force response due to the resonant motion. The damping kernel-based analysis shows that the unexpected behavior stems from time dependence of the hydrodynamic response under nanoconfinement. Our systematic dissipation analysis helps us to infer the origin of the intrinsic dissipation. We also emphasize on the difference in dissipative response of the fluid under nanoconfinement when compared to a fluid exterior case. Our finding highlights a unique feature of confined fluid–structure interaction and evaluates its effect on the performance of high-frequency nanoresonators.
Self-powered smart patch for sweat conductivity monitoring
Authors: Ortega Laura , Llorella Anna , Esquivel Juan Pablo , Sabaté Neus
Published: January 2019

A self-powered skin patch for the measurement of sweat conductivity is presented. The key component of the patch consists of a paper battery that is activated upon absorption of sweat. This body fluid acts as the battery electrolyte, the conductivity of which has a direct impact on the battery-generated output power and voltage. This particular behaviour enables the operation of a very simple and robust conductivity sensor in direct current mode without needing an external power source. The device presented in this paper takes advantage of this new measurement method to develop a sweat patch for screening cystic fibrosis that operates with an extremely simple electronic circuit that minimizes its cost and environmental impact. The patch provides an unambiguous digital result that can be read in an electrochromic display and yields 95% sensitivity and 100% specificity when tested with artificial eccrine perspiration samples.
Metabolic diversity within the globally abundant Marine Group II Euryarchaea offers insight into ecological patterns
Authors: Tully Benjamin J.
Published: January 2019

Despite their discovery over 25 years ago, the Marine Group II Euryarchaea (MGII) remain a difficult group of organisms to study, lacking cultured isolates and genome references. The MGII have been identified in marine samples from around the world, and evidence supports a photoheterotrophic lifestyle combining phototrophy via proteorhodopsins with the remineralization of high molecular weight organic matter. Divided between two clades, the MGII have distinct ecological patterns that are not understood based on the limited number of available genomes. Here, I present a comparative genomic analysis of 250 MGII genomes, providing a comprehensive investigation of these mesophilic archaea. This analysis identifies 17 distinct subclades including nine subclades that previously lacked reference genomes. The metabolic potential and distribution of the MGII genera reveals distinct roles in the environment, identifying algal-saccharide-degrading coastal subclades, protein-degrading oligotrophic surface ocean subclades, and mesopelagic subclades lacking proteorhodopsins, common in all other subclades.
Activity in perceptual classification networks as a basis for human subjective time perception
Authors: Roseboom Warrick , Fountas Zafeirios , Nikiforou Kyriacos , Bhowmik David , Shanahan Murray , Seth Anil K.
Published: January 2019

Despite being a fundamental dimension of experience, how the human brain generates the perception of time remains unknown. Here, we provide a novel explanation for how human time perception might be accomplished, based on non-temporal perceptual classification processes. To demonstrate this proposal, we build an artificial neural system centred on a feed-forward image classification network, functionally similar to human visual processing. In this system, input videos of natural scenes drive changes in network activation, and accumulation of salient changes in activation are used to estimate duration. Estimates produced by this system match human reports made about the same videos, replicating key qualitative biases, including differentiating between scenes of walking around a busy city or sitting in a cafe or office. Our approach provides a working model of duration perception from stimulus to estimation and presents a new direction for examining the foundations of this central aspect of human experience.
Negative longitudinal magnetoresistance in gallium arsenide quantum wells
Authors: Xu Jing , Ma Meng K. , Sultanov Maksim , Xiao Zhi-Li , Wang Yong-Lei , Jin Dafei , Lyu Yang-Yang , Zhang Wei , Pfeiffer Loren N. , West Ken W. , Baldwin Kirk W. , Shayegan Mansour , Kwok Wai-Kwong
Published: January 2019

Negative longitudinal magnetoresistances (NLMRs) have been recently observed in a variety of topological materials and often considered to be associated with Weyl fermions that have a defined chirality. Here we report NLMRs in non-Weyl GaAs quantum wells. In the absence of a magnetic field the quantum wells show a transition from semiconducting-like to metallic behaviour with decreasing temperature. We observe pronounced NLMRs up to 9 Tesla at temperatures above the transition and weak NLMRs in low magnetic fields at temperatures close to the transition and below 5 K. The observed NLMRs show various types of magnetic field behaviour resembling those reported in topological materials. We attribute them to microscopic disorder and use a phenomenological three-resistor model to account for their various features. Our results showcase a contribution of microscopic disorder in the occurrence of unusual phenomena. They may stimulate further work on tuning electronic properties via disorder/defect nano-engineering.
Tip60- and sirtuin 2-regulated MARCKS acetylation and phosphorylation are required for diabetic embryopathy
Authors: Yang Penghua , Xu Cheng , Reece E. Albert , Chen Xi , Zhong Jianxiang , Zhan Min , Stumpo Deborah J. , Blackshear Perry J. , Yang Peixin
Published: January 2019

Failure of neural tube closure results in severe birth defects and can be induced by high glucose levels resulting from maternal diabetes. MARCKS is required for neural tube closure, but the regulation and of its biological activity and function have remained elusive. Here, we show that high maternal glucose induced MARCKS acetylation at lysine 165 by the acetyltransferase Tip60, which is a prerequisite for its phosphorylation, whereas Sirtuin 2 (SIRT2) deacetylated MARCKS. Phosphorylated MARCKS dissociates from organelles, leading to mitochondrial abnormalities and endoplasmic reticulum stress. Phosphorylation dead MARCKS (PD-MARCKS) reversed maternal diabetes-induced cellular organelle stress, apoptosis and delayed neurogenesis in the neuroepithelium and ameliorated neural tube defects. Restoring SIRT2 expression in the developing neuroepithelium exerted identical effects as those of PD-MARCKS. Our studies reveal a new regulatory mechanism for MARCKS acetylation and phosphorylation that disrupts neurulation under diabetic conditions by diminishing the cellular organelle protective effect of MARCKS.
Microbiome networks and change-point analysis reveal key community changes associated with cystic fibrosis pulmonary exacerbations
Authors: Layeghifard Mehdi , Li Hannah , Wang Pauline W. , Donaldson Sylva L. , Coburn Bryan , Clark Shawn T. , Caballero Julio Diaz , Zhang Yu , Tullis D. Elizabeth , Yau Yvonne C. W. , Waters Valerie , Hwang David M. , Guttman David S.
Published: January 2019

Over 90% of cystic fibrosis (CF) patients die due to chronic lung infections leading to respiratory failure. The decline in CF lung function is greatly accelerated by intermittent and progressively severe acute pulmonary exacerbations (PEs). Despite their clinical impact, surprisingly few microbiological signals associated with PEs have been identified. Here we introduce an unsupervised, systems-oriented approach to identify key members of the microbiota. We used two CF sputum microbiome data sets that were longitudinally collected through periods spanning baseline health and PEs. Key taxa were defined based on three strategies: overall relative abundance, prevalence, and co-occurrence network interconnectedness. We measured the association between changes in the abundance of the key taxa and changes in patient clinical status over time via change-point detection, and found that taxa with the highest level of network interconnectedness tracked changes in patient health significantly better than taxa with the highest abundance or prevalence. We also cross-sectionally stratified all samples into the clinical states and identified key taxa associated with each state. We found that network interconnectedness most strongly delineated the taxa among clinical states, and that anaerobic bacteria were over-represented during PEs. Many of these anaerobes are oropharyngeal bacteria that have been previously isolated from the respiratory tract, and/or have been studied for their role in CF. The observed shift in community structure, and the association of anaerobic taxa and PEs lends further support to the growing consensus that anoxic conditions and the subsequent growth of anaerobic microbes are important predictors of PEs.
Multi-loop node line states in ternary MgSrSi-type crystals
Authors: Lian Jinling , Yu Lixian , Liang Qi-Feng , Zhou Jian , Yu Rui , Weng Hongming
Published: January 2019

Node line band-touchings protected by mirror symmetry (named as m-NLs), the product of inversion and time reversal symmetry S = PT (named as s-NLs), or nonsymmorphic symmetry are nontrivial topological objects of topological semimetals in the Brillouin Zone. In this work, we screened a family of MgSrSi-type crystals using first principles calculations, and discovered that more than 70 members are node-line semimetals. A new type of multi-loop structure was found in AsRhTi that a s-NL touches robustly with a m-NL at some “nexus point”, and in the meanwhile a second m-NL crosses with the s-NL to form a Hopf-link. Unlike the previously proposed Hopf-link formed by two s-NLs or two m-NLs, a Hopf-link formed by a s-NL and a m-NL requires a minimal three-band model to characterize its essential electronic structure. The associated topological surface states on different surfaces of AsRhTi crystal were also obtained. Even more complicated and exotic multi-loop structure of NLs were predicted in AsFeNb and PNiNb. Our work may shed light on search for exotic multi-loop node-line semimetals in real materials.
Autophagy–lysosome pathway alterations and alpha-synuclein up-regulation in the subtype of neuronal ceroid lipofuscinosis, CLN5 disease
Authors: Adams Jessie , Feuerborn Melissa , Molina Joshua A. , Wilden Alexa R. , Adhikari Babita , Budden Theodore , Lee Stella Y.
Published: January 2019

Neuronal ceroid lipofuscinoses (NCLs) are a group of inherited neurodegenerative lysosomal storage disorders. CLN5 deficiency causes a subtype of NCL, referred to as CLN5 disease. CLN5 is a soluble lysosomal protein with an unclear function in the cell. Increased levels of the autophagy marker protein LC3-II have been reported in several subtypes of NCLs. In this report, we examine whether autophagy is altered in CLN5 disease. We found that the basal level of LC3-II was elevated in both CLN5 disease patient fibroblasts and CLN5-deficient HeLa cells. Further analysis using tandem fluorescent mRFP-GFP-LC3 showed the autophagy flux was increased. We found the alpha-synuclein (α-syn) gene SNCA was highly up-regulated in CLN5 disease patient fibroblasts. The aggregated form of α-syn is well known for its role in the pathogenicity of Parkinson’s disease. Higher α-syn protein levels confirmed the SNCA up-regulation in both patient cells and CLN5 knockdown HeLa cells. Furthermore, α-syn was localized to the vicinity of lysosomes in CLN5 deficient cells, indicating it may have a lysosome-related function. Intriguingly, knocking down SNCA reversed lysosomal perinuclear clustering caused by CLN5 deficiency. These results suggest α-syn may affect lysosomal clustering in non-neuronal cells, similar to its role in presynaptic vesicles in neurons.
Polymorphisms in MDM2 and TP53 Genes and Risk of Developing Therapy-Related Myeloid Neoplasms
Authors: Cabezas Maria , García-Quevedo Lydia , Alonso Cintia , Manubens Marta , Álvarez Yolanda , Barquinero Joan Francesc , Ramón y Cajal Santiago , Ortega Margarita , Blanco Adoración , Caballín María Rosa , Armengol Gemma
Published: January 2019

One of the most severe complications after successful cancer therapy is the development of therapy-related myeloid neoplasms (t-MN). Constitutional genetic variation is likely to impact on t-MN risk. We aimed to evaluate if polymorphisms in the p53 pathway can be useful for predicting t-MN susceptibility. First, an association study revealed that the Pro variant of theTP53Arg72Pro polymorphism and the G allele of theMDM2SNP309 were associated with t-MN risk. The Arg variant ofTP53is more efficient at inducing apoptosis, whereas the Pro variant is a more potent inductor of cell cycle arrest and DNA repair. As regardsMDM2SNP309, the G allele is associated with attenuation of the p53 apoptotic response. Second, to evaluate the biological effect of theTP53polymorphism, we established Jurkat isogenic cell lines expressing p53Arg or p53Pro. Jurkat p53Arg cells presented higher DNA damage and higher apoptotic potential than p53Pro cells, after treatment with chemotherapy agents. Only p53Pro cells presented t(15;17) translocation and del(5q). We suggest that failure to repair DNA lesions in p53Arg cells would lead them to apoptosis, whereas some p53Pro cells, prone to cell cycle arrest and DNA repair, could undergo misrepair, generating chromosomal abnormalities typical of t-MN.
Downregulation of pectin biosynthesis gene GAUT4 leads to reduced ferulate and lignin-carbohydrate cross-linking in switchgrass
Authors: Li Mi , Yoo Chang Geun , Pu Yunqiao , Biswal Ajaya K. , Tolbert Allison K. , Mohnen Debra , Ragauskas Arthur J.
Published: January 2019

Knockdown (KD) expression of GAlactUronosylTransferase 4 (GAUT4) in switchgrass improves sugar yield and ethanol production from the biomass. The reduced recalcitrance of GAUT4-KD transgenic biomass is associated with reduced cell wall pectic homogalacturonan and rhamnogalacturonan II content and cross-linking, and the associated increases in accessibility of cellulose to enzymatic deconstruction. To further probe the molecular basis for the reduced recalcitrance of GAUT4-KD biomass, potential recalcitrance-related factors including the physicochemical properties of lignin and hemicellulose are investigated. We show that the transgenic switchgrass have a lower abundance of ferulate and lignin-carbohydrate complex cross-linkages, reduced amounts of residual arabinan and xylan in lignin-enriched fractions after enzymatic hydrolysis, and greater coalescence and migration of lignin after hydrothermal pretreatment in comparison to the wild-type switchgrass control. The results reveal the roles of both decreased lignin-polymer and pectin cross-links in the reduction of recalcitrance in PvGAUT4-KD switchgrass.
Representing dynamic biological networks with multi-scale probabilistic models
Authors: Groß Alexander , Kracher Barbara , Kraus Johann M. , Kühlwein Silke D. , Pfister Astrid S. , Wiese Sebastian , Luckert Katrin , Pötz Oliver , Joos Thomas , Van Daele Dries , De Raedt Luc , Kühl Michael , Kestler Hans A.
Published: January 2019

Dynamic models analyzing gene regulation and metabolism face challenges when adapted to modeling signal transduction networks. During signal transduction, molecular reactions and mechanisms occur in different spatial and temporal frames and involve feedbacks. This impedes the straight-forward use of methods based on Boolean networks, Bayesian approaches, and differential equations. We propose a new approach, ProbRules, that combines probabilities and logical rules to represent the dynamics of a system across multiple scales. We demonstrate that ProbRules models can represent various network motifs of biological systems. As an example of a comprehensive model of signal transduction, we provide a Wnt network that shows remarkable robustness under a range of phenotypical and pathological conditions. Its simulation allows the clarification of controversially discussed molecular mechanisms of Wnt signaling by predicting wet-lab measurements. ProbRules provides an avenue in current computational modeling by enabling systems biologists to integrate vast amounts of available data on different scales.
Linking opiate metabolites to heroin through gas chromatography-combustion-isotope ratio mass spectrometry
Authors: Yen Yao-Te , Chen Ting-Yueh , Lai Pin-Jung , Liu Yung-Hsin , Huang Meng-Shun , Chyueh San-Chong , Chang Huan-Tsung
Published: January 2019

A practical gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS) technique was developed for tracing seized heroin through heroin abusers' opiate metabolites.
Halogenation of A-frame μ-carbido complexes: synthesis of μ2-halocarbynes
Authors: Barnett Harrison J. , Hill Anthony F.
Published: January 2019

The new A-frame μ2-carbido complexes [Rh2(μ2-C)X2(μ2-dppm)2] (X = Cl, Br; dppm = Ph2PCH2PPh2) react with PhICl2 or [pyH][Br3] to provide rare examples of μ2-halocarbyne complexes [Rh2(μ-CX)(μ-X)X4(μ-dppm)2] (X = Cl, Br).
Crystal nucleation from solutions of proteins with temperature-independent solubility: a case study of apoferritin
Authors: Dimitrov Ivaylo L.
Published: January 2019

Temperature can alter crystal nucleation kinetics of proteins with temperature-independent solubility, modify the number of nucleation sites and induce polymorphism.
Pressure-varying Langmuir parameters and stepped nitrogen adsorption on alumina and silica
Authors: Brown Trevor C. , Miron David J. , Fellows Christopher M.
Published: January 2019

Nitrogen cross-sectional areas of complete monolayers and multilayers calculated from pressure-varying, Langmuir maximum adsorption capacities for adsorption on macroporous silica.
Spectroscopic evidence for acid–base interaction driven interfacial segregation
Authors: Singla Saranshu , Wilson Michael C. , Dhinojwala Ali
Published: January 2019

Acid–base interactions strongly contribute to the interfacial segregation in polar/non-polar binary liquid mixtures on high-energy-planar solids.
Controllable switching between stable modes in a small network of pulse-coupled chemical oscillators
Authors: Smelov Pavel S. , Proskurkin Ivan S. , Vanag Vladimir K.
Published: January 2019

Switching between stable oscillatory modes in a network of four Belousov–Zhabotinsky oscillators unidirectionally coupled in a ring analysed computationally and experimentally.
A dimer path for CO dissociation on PtSn
Authors: Vandichel Matthias , Grönbeck Henrik
Published: January 2019

Density functional theory calculations are used to investigate CO adsorption, dissociation and SnOX formation on Pt3Sn.
Bridging the gap between laboratory and application in photocatalytic water purification
Authors: Odling Gylen , Robertson Neil
Published: January 2019

Despite a large number of publications in the field, photocatalytic water treatment is still somewhat disconnected from real world application and we highlight recent developments to address this.
Scalable graphene oxide membranes with tunable water channels and stability for ion rejection
Authors: Ghaffar Abdul , Zhang Lina , Zhu Xiaoying , Chen Baoliang
Published: January 2019

Graphene oxide membranes with tunable water channels and stability for ion rejections were fabricated by the blade casting technique and cation intercalation.
Summary of the Faraday Discussion on New memory paradigms: memristive phenomena and neuromorphic applications
Authors: Williams R. Stanley
Published: January 2019

The Faraday Discussion on New memory paradigms: memristive phenomena and neuromorphic systems was held from October 15–17 on the campus of the Rheinisch-Westfälische Technische Hochschule Aachen University, or RWTH Aachen University, under the auspices of the Royal Society of Chemistry.
One-pot synthesis of chiral β-hydroxysulfones from alkynes via aerobic oxysulfonylation and asymmetric reduction in MeOH/H2O
Authors: Cui Peng , Liu Qixing , Wang Juan , Liu Huan , Zhou Haifeng
Published: January 2019

A highly enantioselective synthesis of β-hydroxysulfones from inexpensive and readily available alkynes via a consecutive one-pot reaction in MeOH/H2O under mild conditions is described.
Imaging spectroscopy of Ag plasmas produced by infrared nanosecond laser ablation
Authors: Camacho J. J. , Oujja M. , Sanz M. , Martínez-Hernández A. , Lopez-Quintas I. , de Nalda R. , Castillejo M.
Published: January 2019

Spatially and temporally resolved optical emission spectroscopy has been used to study plasmas formed by 1064 nm pulsed laser ablation of silver targets in a vacuum.
SERS-based droplet microfluidics for high-throughput gradient analysis
Authors: Jeon Jinhyeok , Choi Namhyun , Chen Hao , Moon Joung-Il , Chen Lingxin , Choo Jaebum
Published: January 2019

We report a fully integrated SERS-based microdroplet platform for simultaneous detection of various concentrations of a reagent.
Quinolone-isoniazid hybrids: synthesis and preliminary in vitro cytotoxicity and anti-tuberculosis evaluation
Authors: Beteck Richard M. , Seldon Ronnett , Jordaan Audrey , Warner Digby F. , Hoppe Heinrich C. , Laming Dustin , Legoabe Lesetja J. , Khanye Setshaba D.
Published: January 2019

A new series of quinolone-isoniazid hybrid compounds were designed, synthesised and studied for their potential anti-mycobacterial tuberculosis activity in vitro.
Design, synthesis and biological evaluation of tryptamine salicylic acid derivatives as potential antitumor agents
Authors: Xiong Runde , He Dongxiu , Deng Xiangping , Liu Juan , Lei Xiaoyong , Xie Zhizhong , Cao Xuan , Chen Yanming , Peng Junmei , Tang Guotao
Published: January 2019

According to the combination principle, target compounds were designed, and compound E20 might be a promising anti-tumor agent targeting gastric cancer.
Isolation of naturally occurring novel isoflavonoids: an update
Authors: Al-Maharik Nawaf
Published: January 2019

This review covers the literature concerning the isolation and identification of new naturally occurring isoflavonoids from Leguminosae and non-Leguminous species between 2012–2017.
Understanding the role of AgNO3 concentration and seed morphology in the achievement of tunable shape control in gold nanostars
Authors: Atta Supriya , Beetz Michael , Fabris Laura
Published: January 2019

Gold nanostars are one of the most fascinating anisotropic nanoparticles.
Self-assembly of highly asymmetric, poly(ionic liquid)-rich diblock copolymers and the effects of simple structural modification on phase behaviour
Authors: May Alyssa W. , Shi Zhangxing , Wijayasekara Dilanji B. , Gin Douglas L. , Bailey Travis S.
Published: January 2019

A series of ATRP-synthesized poly(IL) diblock copolymers exhibit morphological phase behavior with shifted phase boundaries and alkyl substituent dependent segregation.
Retracted Article: Exosomal miR-25-3p derived from hypoxia tumor mediates IL-6 secretion and stimulates cell viability and migration in breast cancer
Authors: Li Zhengmin , He Fang , Yang Zhanjia , Cao Xueming , Dai Shuyang , Zou Jie , Xu Poshi , Zhou Zhou
Published: January 2019

Hypoxia is a major hallmark of solid tumors and is associated with malignant phenotypes.
Production of green biofuel by using a goat manure supported Ni–Al hydrotalcite catalysed deoxygenation process
Authors: Zdainal Abidin Shajaratun Nur , Lee Hwei Voon , Juan Joon Ching , Rahman Noorsaadah Abd , Taufiq-Yap Yun Hin
Published: January 2019

Deoxygenation pathway of oleic acid to bio-hydrocarbon involves decarboxylation/decarbonylation of oxygen content from fatty acid structure in the form of carbon dioxide (CO2)/carbon monoxide (CO), respectively, with the presence of goat manure supported Ni–Al hydrotalcite (Gm/Ni–Al) catalyst.
Nickel exchanged supported 12-tungstophosphoric acid: synthesis, characterization and base free one-pot oxidative esterification of aldehyde and alcohol
Authors: Patel Anish , Patel Anjali
Published: January 2019

The synthesis and characterization of a bi-functional catalyst consisting of nickel and supported 12-tungstophosphoric acid are reported as well as its application in one pot oxidative esterification of benzaldehyde and benzyl alcohol to benzoate ester.
Explosives sensing using Ag–Cu alloy nanoparticles synthesized by femtosecond laser ablation and irradiation
Authors: Satya Bharati Moram Sree , Chandu Byram , Rao S. Venugopal
Published: January 2019

Herein we demonstrate the synthesis of Ag–Cu alloy NPs through a consecutive two-step process; laser ablation followed by laser irradiation.
Formal [4 + 1] cycloaddition of in situ generated 1,2-diaza-1,3-dienes with diazo esters: facile approaches to dihydropyrazoles containing a quaternary center
Authors: Chen Bo , Chu Wen-Dao , Liu Quan-Zhong
Published: January 2019

A Cu(ii)/bisoxazoline ligand-promotes the formal [4 + 1] cycloaddition of diazo esters with azoalkenes formed in situ. This provides a protocol for construction of dihydropyrazoles containing a quaternary center with good to excellent yields.
Sintered porous Ti6Al4V scaffolds incorporated with recombinant human bone morphogenetic protein-2 microspheres and thermosensitive hydrogels can enhance bone regeneration
Authors: Li Ji , Li Zhongli , Wang Qi , Shi Yueyi , Li Wei , Fu Yangmu , Jin Gong
Published: January 2019

Porous Ti6Al4V scaffolds incorporated with rhBMP-2 microspheres and CS-TA hydrogel can enhance the bone regeneration.
The dietary flavonoid isoliquiritigenin is a potent cytotoxin for human neuroblastoma cells
Authors: Alshangiti Amnah M. , Togher Katie L. , Hegarty Shane V. , Sullivan Aideen M. , O’Keeffe Gerard W.
Published: January 2019

Neuroblastoma (NB) is the most common extracranial solid tumor of early childhood; it accounts for approximately 8–10% of all childhood cancers and is the most common cancer in children in the first year of life. Patients in the high-risk group have a poor prognosis, with relapses being common and often refractory to drug treatment in those that survive. Moreover, the drug treatment itself can lead to a range of long-term sequelae. Therefore, there is a critical need to identify new therapeutics for NB. Isoliquiritigenin (ISLQ) is a naturally-occurring, dietary chalcone-type flavonoid with a range of biological effects that depend on the cell type and context. ISLQ has potential as an anticancer agent. Here we show that ISLQ has potent cytotoxic effects on SK-N-BE(2) and IMR-32 human NB cells, which carry amplification of the MYCN gene, the main prognostic marker of poor survival in NB. ISLQ was found to increase cellular reactive oxygen species (ROS). The cytotoxic effect of ISLQ was blocked by small molecule inhibitors of oxidative stress-induced cell death, and by the antioxidant N-acetyl-l-cysteine (NAC). Combined treatment of either SK-N-B-E(2) or IMR-32 cells with ISLQ and the anticancer agent cisplatin resulted in loss of cell viability that was greater than that induced by cisplatin alone. This study provides proof-of-principle that ISLQ is a potent cytotoxin for MYCN-amplified human NB cells. This is an important first step in rationalizing the further study of ISLQ as a potential adjunct therapy for high-risk NB.
Development of numerical cognition in children and artificial systems: a review of the current knowledge and proposals for multi‐disciplinary research
Authors: Di Nuovo Alessandro , Jay Tim
Published: January 2019

Numerical cognition is a distinctive component of human intelligence such that the observation of its practice provides a window in high‐level brain function. The modelling of numerical abilities in artificial cognitive systems can help to confirm existing child development hypotheses and define new ones by means of computational simulations. Meanwhile, new research will help to discover innovative principles for the design of artificial agents with advanced reasoning capabilities and clarify the underlying algorithms (e.g. deep learning) that can be highly effective but difficult to understand for humans. This study promotes new investigation by providing a common resource for researchers with different backgrounds, including computer science, robotics, neuroscience, psychology, and education, who are interested in pursuing scientific collaboration on mutually stimulating research on this topic. The study emphasises the fundamental role of embodiment in the initial development of numerical cognition in children. This strong relationship with the body motivates the cognitive developmental robotics (CDR) approach for new research that can (among others) help standardise data collection and provide open databases for benchmarking computational models. Furthermore, the authors discuss the potential application of robots in classrooms and argue that the CDR approach can be extended to assist educators and favour mathematical education.
Segmentation and generalisation for writing skills transfer from humans to robots
Authors: Li Chunxu , Yang Chenguang , Giannetti Cinzia
Published: January 2019

In this study, the authors present an enhanced generalised teaching by demonstration technique for a KUKA iiwa robot. Movements are recorded from a human operator, and then the recorded data are sent to be segmented via MATLAB by using the difference method (DV). The outputted trajectories data are used to model a non‐linear system named dynamic movement primitive (DMP). For the purpose of learning from multiple demonstrations correctly and accurately, the Gaussian mixture model is employed for the evaluation of the DMP in order to modelling multiple trajectories by the teaching of demonstrator. Furthermore, a synthesised trajectory with smaller position errors in 3D space has been successfully generated by the usage of the Gaussian mixture regression algorithm. The proposed approach has been tested and demonstrated by performing a Chinese characters writing task with a KUKA iiwa robot.
HVD code: a class of MDS array codes for tolerating triple disk failures
Authors: Chen Xin , Cai Suihua , Ma Xiao
Published: January 2019

In this study, the authors propose a class of exclusive OR (XOR)‐based maximum distance separable (MDS) array codes, referred to as horizontal–vertical–diagonal (HVD) codes, which can tolerate triple disk failures with optimal update complexity. The HVD code has a similar data/parity layout to the horizontal–vertical (HV) code and has many figures of merits as the HV code. Also, an efficient recovery algorithm is proposed, which can be implemented to accelerate the recovery process of double disk failures by making full use of all kinds of parities in the HVD code. The authors evaluate the encoding/decoding efficiency of the HVD code by comparing the number of XORs and the number of disk reads with other MDS array codes. Results show that the HVD code inherits most of the merits of the HV code and requires less number of disk reads when recovering single disk failure.
Ensemble multi‐objective evolutionary algorithm for gene regulatory network reconstruction based on fuzzy cognitive maps
Authors: Liu Jing , Chi Yaxiong , Liu Zongdong , He Shan
Published: January 2019

Many methods aim to use data, especially data about gene expression based on high throughput genomic methods, to identify complicated regulatory relationships between genes. The authors employ a simple but powerful tool, called fuzzy cognitive maps (FCMs), to accurately reconstruct gene regulatory networks (GRNs). Many automated methods have been carried out for training FCMs from data. These methods focus on simulating the observed time sequence data, but neglect the optimisation of network structure. In fact, the FCM learning problem is multi‐objective which contains network structure information, thus, the authors propose a new algorithm combining ensemble strategy and multi‐objective evolutionary algorithm (MOEA), called EMOEAFCM ‐GRN, to reconstruct GRNs based on FCMs. In EMOEAFCM ‐GRN, the MOEA first learns a series of networks with different structures by analysing historical data simultaneously, which is helpful in finding the target network with distinct optimal local information. Then, the networks which receive small simulation error on the training set are selected from the Pareto front and an efficient ensemble strategy is provided to combine these selected networks to the final network. The experiments on the DREAM4 challenge and synthetic FCMs illustrate that EMOEAFCM ‐GRN is efficient and able to reconstruct GRNs accurately.
Wide-area photometric and astrometric (Gaia DR2) study of the young cluster NGC 6530
Authors: Damiani F. , Prisinzano L. , Micela G. , Sciortino S.
Published: January 2019

Context. NGC 6530 is a young cluster, with a complex morphology and star-formation history. We present a statistical study of its global properties, using a new, large list of candidate members down to masses of 0.2−0.4 M⊙ and Gaia DR2 astrometry.

Aims. We consider a larger sky region compared to previous studies, to investigate the entire cluster until its periphery, including any diffuse population all around the main cluster. We study the distribution of extinction and age across the different regions, and obtain constraints on the star-formation history. We also study the dynamics of cluster members.

Methods. Cluster membership was determined on the basis of literature X-ray data, Hα emission, near-IR and UV excesses from the VPHAS+ and UKIDSS photometric surveys and published near-IR catalogs, and Gaia DR2 astrometry; moreover, we used a method for photometric selection of M-type pre-main-sequence cluster members, which we recently developed and used for other star-formation regions. The list of candidates includes nearly 3700 stars, of which we estimate approximately 2700 to be genuine NGC 6530 members.

Results. Using Gaia parallaxes, the cluster distance is found to be 1325 pc, with errors of 0.5% (statistical) and 8.5% (systematic), in agreement with previous determinations. The cluster morphology and boundaries are established with great confidence, from the agreement between the subsamples of members selected using different criteria. There is no diffuse population of members around the cluster, but there are minor condensations of true members in addition to the two main groups in the cluster core and in the Hourglass nebula. Two such subgroups are spatially associated with the stars 7 Sgr (F2II-III) and HD 164536 (O7.5V). There is a definite pattern of sequential star formation across the cluster, within an age range from less than 0.5 Myr to ∼5 Myr. Extinction is spatially non-uniform, with part of the population still embedded or obscured by thick dust. The precise Gaia proper motion data indicate that the NGC 6530 parent cloud collided with the Galactic plane around 4 Myr ago, and we suggest that event as the trigger of the bulk of star formation in NGC 6530. The internal cluster dynamics is also partially resolved by the Gaia data, indicating expansion of the main cluster population with respect to its center.
Comparison of results on Neff from various Planck likelihoods
Authors: Henrot-Versillé S. , Couchot F. , Garrido X. , Imada H. , Louis T. , Tristram M. , Vanneste S.
Published: January 2019

In this paper, we study the estimation of the effective number of relativistic species from a combination of cosmic microwave background (CMB) and baryon acoustic oscillations (BAO) data. We vary different ingredients of the analysis: the Planck high-ℓ likelihoods, the Boltzmann solvers, and the statistical approaches. The variation of the inferred values gives an indication of an additional systematic uncertainty, which is of the same order of magnitude as the error derived from each individual likelihood. We show that this systematic uncertainty is essentially associated to the assumptions made in the high-ℓ likelihood implementations, in particular for the foreground residuals modellings. We also compare a subset of likelihoods using only the TE power spectra, expected to be less sensitive to foreground residuals.
Origin of the multiwavelength emission of PKS 0502+049
Authors: Sahakyan N.
Published: January 2019

The origin of the multiwavelength emission from PKS 0502+049 neighboring the first cosmic neutrino source TXS 0506+056 is studied using the data observed byFermi-Large Area Telescope andSwiftUltraViolet/Optical Telescope and X-Ray Telescope. This source was in a flaring state in the considered bands before and after the neutrino observations in 2014–2015, characterized by hard emission spectra in the X-ray andγ-ray bands, ≃1.5 − 1.8 and ≤2.0, respectively. During the neutrino observations, theγ-ray spectrum shows a deviation from a simple power-law shape, indicating a spectral cutoff atEc = 8.50 ± 2.06 GeV. The spectral energy distributions of PKS 0502+049 are modeled within a one-zone leptonic scenario assuming that high energyγ-ray emission is produced either by inverse Compton scattering of synchrotron or dusty torus photons by the electron population that produce the radio-to-optical emission. Alternatively, the observedγ-rays are modeled considering inelastic interaction of protons, when the jet interacts with a dense gaseous target. During the neutrino observations, theγ-ray data are best described when the proton energy distribution is ∼E−2.61pand if the protons are effectively accelerated up to 10 PeV, the expected neutrino rate is ∼1.1 events within 110 days. In principle, if theγ-ray emission with a hard photon index observed during the flaring periods extends up to teraelectronvolt energies, the expected rate can be somewhat higher, but such conditions are hardly possible. Within the hadronic interpretation, theγ-ray data can be reproduced only when the accretion rate of PKS 0502+049 is in the super-Eddington regime, as opposed to the leptonic scenario. From the point of view of the necessary energetics, as well as considering that the required parameters are physically reasonable, when the neutrinos were observed the broadband emission from PKS 0502+049 was most likely of a leptonic origin.
Effect of inherent tibial asymmetry on leg length discrepancy measurements after intramedullary nailing of comminuted femoral shaft fractures
Authors: Hudson Ian , Mauch Krystalyn , Schuurman Meg , Padela Muhammad T. , Gheraibeh Petra , Vaidya Rahul
Published: January 2019

Introduction: Locked intramedullary nailing (IMN) is the standard treatment for femoral shaft fractures in adults with high rates of union and relatively low rates of complications. Leg length discrepancy (LLD) after IMN of femoral shaft fractures is common, and is reported in 20–43% of cases. A known surgical challenge when trying to obtain equal leg lengths is comminuted fracture, which results in a loss of bony landmarks that guide reduction. The purpose of this study was to assess the effect of inherent tibial asymmetry on LLD measurements after IMN.

Methods: Postoperative CT scanograms were performed on 79 consecutive patients after locked IMN for comminuted femoral shaft fracture. Leg lengths were determined by measurements taken from the scout view of a CT scanogram. Calculations of discrepancy were made for both femurs, tibias, and total leg length. Assessment was also made on the frequency wherein the tibial discrepancy compounded the femoral discrepancy. In situations where a limb segment was exactly symmetric to the contralateral side, the total leg was not regarded as a having compounded asymmetry.

Results: Notable discrepancies were found in tibial length that significantly departed from the null of symmetry (p < 0.0001). Forty-two patients (53.2%) were found to have a tibial asymmetry of 3 mm or more, and 20 patients (25.3%) were found to exhibit a difference of 6.3 mm or more. Median femoral discrepancy was 5.3 mm and median tibial discrepancy was 3.0 mm. Seven patients were found to be asymmetric in total leg length as a consequence of underlying tibial asymmetry. Conversely, 11 patients benefited from their tibial asymmetry, which compensated for femoral asymmetry after IMN.

Conclusion: Tibial symmetry cannot be assumed. If not accounted for, inherent tibial asymmetry may influence LLD after IMN of femur fractures.