bluuebunny/crossref_metadata_2025_split huggingface dataset:
Investigating solvent effects on the magnetic properties of molybdate ions () with relativistic embedding
Authors: Halbert Loïc , Olejniczak Małgorzata , Vallet Valérie , Severo Pereira Gomes André 
Published: March 2020

AbstractWe investigate the ability of mechanical and electronic density functional theory‐based embedding approaches to describe the solvent effects on nuclear magnetic resonance (NMR) shielding constants of the 95Mo nucleus in the molybdate ion in aqueous solution. From the description obtained from calculations with two‐ and four‐component relativistic Hamiltonians, we find that, for such systems, spin‐orbit coupling effects are clearly important for absolute shielding values, but for relative quantities, a scalar relativistic treatment provides sufficient estimation of the solvent effects. We find that the electronic contributions to the solvent effects are relatively modest yet decisive to provide a more accurate magnetic response of the system when compared to reference supermolecular calculations. We analyze the errors in the embedding calculations by statistical methods, as well as through a real‐space representation of NMR shielding densities, which are shown to provide a clear picture of the physical processes at play.
Mass spectral fragmentation of perfluoroacyl derivatives of half nitrogen mustards for their detection by gas chromatography/mass spectrometry
Authors: Chandra Buddhadeb , Sinha Roy Kanchan , Shaik Mahabul , Waghmare Chandrakant , Palit Meehir 
Published: March 2020

RationaleAnalytical methods for the detection and identification of half nitrogen mustards (halfNMs), i.e., partially hydrolyzed products of nitrogen mustards (pHpNMs), using silyl derivatives are often associated with low sensitivity and selectivity. In order to overcome these limitations, the derivatization of halfNMs was performed using perfluoroacylation.MethodsTwo efficient derivatization techniques using trifluoroacetyl (TFA) and heptafluorobutyryl (HFB) groups were developed for the unambiguous identification of halfNMs. A mass spectral database was generated by performing gas chromatography/electron ionization mass spectrometry (GC/EI‐MS) and gas chromatography/positive chemical ionization mass spectrometry (GC/PCI‐MS). The fragmentation pathways were studied by tandem mass spectrometry (MS/MS) in both EI and PCI mode.ResultsThe EI‐MS spectra of the TFA and HFB derivatives of halfNMs contain intense molecular ions and fragment ions, thus making perfluoroacylation preferable to silylation. In addition, the background‐free chromatogram obtained using these derivatives provides unambiguous identification of these compounds in blind samples. The structures of the fragment ions were postulated, and the sources of significant ions were traced by performing MS/MS precursor ion scans. In the PCI‐MS spectra, along with the protonated molecule, significant peaks due to neutral losses of HF, HCl, CH3Cl and CF3COOH were observed.ConclusionsThis is the first report of the elucidation of the fragmentation pathways of perfluoroacyl derivatives of halfNMs. The complementary GC/PCI‐MS and GC/PCI‐MS/MS data will be helpful in the identification of unknown metabolites in a fast and reliable fashion.
Quantum chemical mass spectrometry: Ab initio study of b2‐ion formation mechanisms for the singly protonated Gln‐His‐Ser tripeptide
Authors: Cautereels Julie , Giribaldi Julien , Enjalbal Christine , Blockhuys Frank 
Published: March 2020

RationaleBoth amide bond protonation triggering peptide fragmentations and the controversial b2‐ion structures have been subjects of intense research. The involvement of histidine (H), with its imidazole side chain that induces specific dissociation patterns involving inter‐side‐chain (ISC) interactions, in b2‐ion formation was investigated, focusing on the QHS model tripeptide.MethodsTo identify the effect of histidine on fragmentations issued from ISC interactions, QHS was selected for a comprehensive analysis of the pathways leading to the three possible b2‐ion structures, using quantum chemical calculations performed at the DFT/B3LYP/6‐311+G* level of theory. Electrospray ionization ion trap mass spectrometry allowed the recording of MS2 and MS3 tandem mass spectra, whereas the Quantum Chemical Mass Spectrometry for Materials Science (QCMS2) method was used to predict fragmentation patterns.ResultsWhereas it is very difficult to differentiate among protonated oxazolone, diketopiperazine, or lactam b2‐ions using MS2 and MS3 mass spectra, the calculations indicated that the QH b2‐ion (detected at m/z 266) is probably a mixture of the lactam and oxazolone structures formed after amide nitrogen protonation, making the formation of diketopiperazine less likely as it requires an additional step for its formation.ConclusionsIn contrast to glycine‐histidine‐containing b2‐ions, known to be issued from the backbone‐imidazole cyclization, we found that interactions between the side chains were not obvious to perceive, neither from a thermodynamics nor from a fragmentation perspective, emphasizing the importance of the whole sequence on the dissociation behavior usually demonstrated from simple glycine‐containing tripeptides.
Emerging trends and new developments in Lancang‐Mekong River: A bibliometric visualization analysis
Authors: Junlin Ren , Ziqian Peng , Xue Pan 
Published: March 2020

AbstractThe purpose of this study is to outline global performance, and to quantitatively evaluate the current research field hot spots, and the future trends about the Lancang‐Mekong River (LMR). Bibliometric methods are used to analyze 3,924 records retrieved from the collection of the Web of Science Core (WoS). The performance of publications, categories, countries, institutes, research hot spots and trends is analyzed in this study by applying CiteSpace and VOSviewer tools. The results revealed that publications about the LMR field have been increasing rapidly since the beginning of the 21st century. The research pertaining to LMR is mainly in the fields of environmental sciences & ecology, water resources, geology, engineering and agriculture. Vietnam, The People's Republic of China, The United States of America, Japan and Thailand get higher rankings in paper output, and Can Tho University, the Chinese Academy of Sciences, Beijing Normal University and the University of Tokyo achieve a high ranking on LMR research. In addition, further studies in research frontiers have revealed that health, security, climate change and international waters will become the new and popular directions and trends in the LMR research.
LUH-GRACE2018: A New Time Series of Monthly Gravity Field Solutions from GRACE
Authors: Koch Igor , Flury Jakob , Naeimi Majid , Shabanloui Akbar 
Published: March 2020

AbstractIn this contribution, we present the LUH-GRACE2018 time series of monthly gravity field solutions covering the period January 2003–March 2016. The solutions are obtained from GRACE K-Band Range Rate (KBRR) measurements as main observations. The monthly solutions are computed using the in-house developed GRACE-SIGMA software. The processing is based on dynamic orbit and gravity field determination using variational equations and consists of two main steps. In the first step, 3-hourly orbital arcs of the two satellites and the state transition and sensitivity matrices are dynamically integrated using a modified Gauss-Jackson integrator. In this step, initial state vectors and 3D accelerometer bias parameters are adjusted using GRACE Level-1B reduced-dynamic positions as observations. In the second step, normal equations are accumulated and the normalized spherical harmonic coefficients up to degree and order 80 are estimated along with arc-wise initial states, accelerometer biases and empirical KBRR parameters. Here KBRR measurements are used as main observations and reduced-dynamic positions are introduced to solve for the low frequency coefficients. In terms of error degree standard deviations as well as Equivalent Water Heights (EWH), our gravity field solutions agree well with RL05 solutions of CSR, GFZ and JPL.
Privacy Implications of Voice and Speech Analysis – Information Disclosure by Inference
Authors: Kröger Jacob Leon , Lutz Otto Hans-Martin , Raschke Philip 
Published: March 2020

Abstract
Internet-connected devices, such as smartphones, smartwatches, and laptops, have become ubiquitous in modern life, reaching ever deeper into our private spheres. Among the sensors most commonly found in such devices are microphones. While various privacy concerns related to microphone-equipped devices have been raised and thoroughly discussed, the threat of unexpected inferences from audio data remains largely overlooked. Drawing from literature of diverse disciplines, this paper presents an overview of sensitive pieces of information that can, with the help of advanced data analysis methods, be derived from human speech and other acoustic elements in recorded audio. In addition to the linguistic content of speech, a speaker’s voice characteristics and manner of expression may implicitly contain a rich array of personal information, including cues to a speaker’s biometric identity, personality, physical traits, geographical origin, emotions, level of intoxication and sleepiness, age, gender, and health condition. Even a person’s socioeconomic status can be reflected in certain speech patterns. The findings compiled in this paper demonstrate that recent advances in voice and speech processing induce a new generation of privacy threats.
Magnetic-Sparseness and Schrödinger Operators on Graphs
Authors: Bonnefont Michel , Golénia Sylvain , Keller Matthias , Liu Shiping , Münch Florentin 
Published: March 2020

Abstract
We study magnetic Schrödinger operators on graphs. We extend the notion of sparseness of graphs by including a magnetic quantity called the frustration index. This notion of magnetic-sparseness turns out to be equivalent to the fact that the form domain is an $$\ell ^{2}$$ℓ2 space. As a consequence, we get criteria of discreteness for the spectrum and eigenvalue asymptotics.
Concave power solutions of the dominative p-Laplace equation
Authors: Høeg Fredrik Arbo 
Published: March 2020

AbstractIn this paper, we study properties of solutions of the Dominative p-Laplace equation with homogeneous Dirichlet boundary conditions in a bounded convex domain $$\Omega $$Ω. For the equation $$-{\mathcal {D}}_p u= 1$$-Dpu=1, we show that $$\sqrt{u}$$u is concave, and for the eigenvalue problem $${\mathcal {D}}_p u + \lambda u=0$$Dpu+λu=0, we show that $$\log {u}$$logu is concave.
Testing the effectiveness of pyrazine defences against spiders
Authors: Burdfield-Steel Emily R. , Schneider Jutta M. , Mappes Johanna , Dobler Susanne 
Published: March 2020

AbstractInsects live in a dangerous world and may fall prey to a wide variety of predators, encompassing multiple taxa. As a result, selection may favour defences that are effective against multiple predator types, or target-specific defences that can reduce predation risk from particular groups of predators. Given the variation in sensory systems and hunting tactics, in particular between vertebrate and invertebrate predators, it is not always clear whether defences, such as chemical defences, that are effective against one group will be so against another. Despite this, the majority of research to date has focused on the role of a single predator species when considering the evolution of defended prey. Here we test the effectiveness of the chemical defences of the wood tiger moth, a species previously shown to have defensive chemicals targeted towards ants, against a common invertebrate predator: spiders. We presented both live moths and artificial prey containing their defensive fluids to female Trichonephila senegalensis and recorded their reactions. We found that neither of the moth’s two defensive fluids were able to repel the spiders, and confirmed that methoxypyrazines, a major component of the defences of both the wood tiger moth and many insect species, are ineffective against web-building spiders. Our results highlight the variability between predator taxa in their susceptibility to chemical defences, which can in part explain the vast variation in these chemicals seen in insects, and the existence of multiple defences in a single species.
Adaptive radiotherapy and the dosimetric impact of inter- and intrafractional motion on the planning target volume for prostate cancer patients
Authors: Böckelmann Felix , Putz Florian , Kallis Karoline , Lettmaier Sebastian , Fietkau Rainer , Bert Christoph 
Published: March 2020

Abstract
Purpose
To investigate the dosimetric influence of daily interfractional (inter) setup errors and intrafractional (intra) target motion on the planning target volume (PTV) and the possibility of an offline adaptive radiotherapy (ART) method to correct larger patient positioning uncertainties in image-guided radiotherapy for prostate cancer (PCa).

Materials and methods
A CTV (clinical target volume)-to-PTV margin ranging from 15 mm in LR (left-right) and SI (superior-inferior) and 5–10 mm in AP (anterior-posterior) direction was applied to all patients. The dosimetric influence of this margin was retrospectively calculated by analysing systematic and random components of inter and intra errors of 31 consecutive intermediate- and high-risk localized PCa patients using daily cone beam computed tomography and kV/kV (kilo-Voltage) imaging. For each patient inter variation was assessed by observing the first 4 treatment days, which led to an offline ART-based treatment plan in case of larger variations.

Results:
Systematic inter uncertainties were larger (1.12 in LR, 2.28 in SI and 1.48 mm in AP) than intra systematic errors (0.44 in LR, 0.69 in SI and 0.80 mm in AP). Same findings for the random error in SI direction with 3.19 (inter) and 2.30 mm (intra), whereas in LR and AP results were alike with 1.89 (inter) and 1.91 mm (intra) and 2.10 (inter) and 2.27 mm (intra), respectively. The calculated margin revealed dimensions of 4–5 mm in LR, 8–9 mm in SI and 6–7 mm in AP direction. Treatment plans which had to be adapted showed smaller variations with 1.12 (LR) and 1.72 mm (SI) for Σ and 4.17 (LR) and 3.75 mm (SI) for σ compared to initial plans with 1.77 and 2.62 mm for Σ and 4.46 and 5.39 mm for σ in LR and SI, respectively.

Conclusion
The currently clinically used margin of 15 mm in LR and SI and 5–10 mm in AP direction includes inter and intra uncertainties. The results show that offline ART is feasible which becomes a necessity with further reductions in PTV margins.
Quasi-experimental evidence for the causal link between fertility and subjective well-being
Authors: Priebe Jan 
Published: March 2020

AbstractThis article presents causal evidence on the impact of fertility on women’s subjective well-being using quasi-experimental variation due to preferences for a mixed sibling sex composition (having at least one child of each sex). Based on a large sample of women from 35 developing countries, I find that having children increases mothers’ life satisfaction and happiness. I further establish that the positive impact of fertility on subjective well-being can be explained by related increases in mothers’ satisfaction with family life, friendship, and treatment by others.
Effective visco-elastic models of tough, doubly cross-linked, single-network polyvinyl alcohol (PVA) hydrogels
Authors: Kari Leif 
Published: March 2020

AbstractAn effective fractional derivative-based visco-elastic model of tough, doubly cross-linked, single-network polyvinyl alcohol (PVA) hydrogels, embodying both chemical and physical cross-links, is developed using a Mittag–Leffler relaxation function of order 1/2 while applying only three material parameters that are physically quantifiable, namely frequency for maximum loss modulus, equilibrium elastic modulus and relaxation intensity. The resulting 3-parameter shear modulus model is possible to additively split into chemical and physical parts; the split being the study focus. Physical explanations of the visco-elastic low-, mid- and high-frequency range properties, and their transitions between the frequency ranges, are given mainly in terms of the permanent chemical cross-links and the distinct adhesion–deadhesion processes of the transient physical cross-links. The latter are running from an associated Rouse mode low-frequency behaviour through a maximum adhesion–deadhesion dissipation and to an elastic, fully active cross-link high-frequency behaviour, while the former are displaying essentially an elastic, fully active cross-link behaviour throughout the frequency range. The developed model covers the full frequency range while matching measurements results remarkably well. Furthermore, the model is refined into a 4-parameter model by additively including an Abel relaxation function of order 1/2 to take into account the superimposed Rouse-type behaviour found in the measurements of the chemical cross-links in addition to their dominating elastic response, with the fourth parameter being a chemical Rouse stress intensity factor. The simple, effective visco-elastic models are suitable in predicting the mechanical properties of tough, doubly cross-linked, single-network PVA hydrogels with application potentials in tissue and noise abatement engineering.
Online dimensional control of rolled steel profiles using projected fringes
Authors: Gåsvik Kjell J. , Robbersmyr Kjell G. , Vadseth Trond 
Published: March 2020

AbstractFringe projection is a versatile method for mapping the topography of surfaces. In this paper, it is used to measure the defects on the head of railroad rails while the rails are moving. Railroad rails are made by hot rolling. The quality of the finished product is generally good, but surface texture will deteriorate with increasing temperature. A method for online inspection therefore is very desirable. In the present experiment, dimensional inspection of the railroad rails was made online while moving at a speed of 1–2 m/s. Therefore, it is important to minimize the registration time. To achieve this, we apply a method of fringe location with sub-pixel accuracy that requires only a single exposure for each registration.
A high-throughput platform for detailed lipidomic analysis of a range of mouse and human tissues
Authors: Furse Samuel , Fernandez-Twinn Denise S. , Jenkins Benjamin , Meek Claire L. , Williams Huw E. L. , Smith Gordon C. S. , Charnock-Jones D. Stephen , Ozanne Susan E. , Koulman Albert 
Published: March 2020

AbstractLipidomics is of increasing interest in studies of biological systems. However, high-throughput data collection and processing remains non-trivial, making assessment of phenotypes difficult. We describe a platform for surveying the lipid fraction for a range of tissues. These techniques are demonstrated on a set of seven different tissues (serum, brain, heart, kidney, adipose, liver, and vastus lateralis muscle) from post-weaning mouse dams that were either obese (> 12 g fat mass) or lean (<5 g fat mass). This showed that the lipid metabolism in some tissues is affected more by obesity than others. Analysis of human serum (healthy non-pregnant women and pregnant women at 28 weeks’ gestation) showed that the abundance of several phospholipids differed between groups. Human placenta from mothers with high and low BMI showed that lean placentae contain less polyunsaturated lipid. This platform offers a way to map lipid metabolism with immediate application in metabolic research and elsewhere.
Universal Gaps for XOR Games from Estimates on Tensor Norm Ratios
Authors: Aubrun Guillaume , Lami Ludovico , Palazuelos Carlos , Szarek Stanisław J. , Winter Andreas 
Published: March 2020

AbstractWe define and study XOR games in the framework of general probabilistic theories, which encompasses all physical models whose predictive power obeys minimal requirements. The bias of an XOR game under local or global strategies is shown to be given by a certain injective or projective tensor norm, respectively. The intrinsic (i.e. model-independent) advantage of global over local strategies is thus connected to a universal functionr(n, m) called ‘projective–injective ratio’. This is defined as the minimal constant$$\rho $$ρsuch that$$\Vert \cdot \Vert _{X\otimes _\pi Y}\leqslant \rho \,\Vert \cdot \Vert _{X\otimes _\varepsilon Y}$$‖·‖X⊗πY⩽ρ‖·‖X⊗εYholds for all Banach spaces of dimensions$$\dim X=n$$dimX=nand$$\dim Y=m$$dimY=m, where$$X\otimes _\pi Y$$X⊗πYand$$X \otimes _\varepsilon Y$$X⊗εYare the projective and injective tensor products. By requiring that$$X=Y$$X=Y, one obtains a symmetrised version of the above ratio, denoted by$$r_s(n)$$rs(n). We prove that$$r(n,m)\geqslant 19/18$$r(n,m)⩾19/18for all$$n,m\geqslant 2$$n,m⩾2, implying that injective and projective tensor products are never isometric. We then study the asymptotic behaviour ofr(n, m) and$$r_s(n)$$rs(n), showing that, up to log factors:$$r_s(n)$$rs(n)is of the order$$\sqrt{n}$$n(which is sharp);r(n, n) is at least of the order$$n^{1/6}$$n1/6; andr(n, m) grows at least as$$\min \{n,m\}^{1/8}$$min{n,m}1/8. These results constitute our main contribution to the theory of tensor norms. In our proof, a crucial role is played by an ‘$$\ell _1/\ell _2/\ell _{\infty }$$ℓ1/ℓ2/ℓ∞trichotomy theorem’ based on ideas by Pisier, Rudelson, Szarek, and Tomczak-Jaegermann. The main operational consequence we draw is that there is a universal gap between local and global strategies in general XOR games, and that this grows as a power of the minimal local dimension. In the quantum case, we are able to determine this gap up to universal constants. As a corollary, we obtain an improved bound on the scaling of the maximal quantum data hiding efficiency against local measurements.
A C*-algebraic Approach to Interacting Quantum Field Theories
Authors: Buchholz Detlev , Fredenhagen Klaus 
Published: March 2020

AbstractA novel C*-algebraic framework is presented for relativistic quantum field theories, fixed by a Lagrangean. It combines the postulates of local quantum physics, encoded in the Haag–Kastler axioms, with insights gained in the perturbative approach to quantum field theory. Key ingredients are an appropriate version of Bogolubov’s relative S-operators and a reformulation of the Schwinger–Dyson equations. These are used to define for any classical relativistic Lagrangean of a scalar field a non-trivial local net of C*-algebras, encoding the resulting interactions at the quantum level. The construction works in any number of space-time dimensions. It reduces the longstanding existence problem of interacting quantum field theories in physical spacetime to the question of whether the C*-algebras so constructed admit suitable states, such as stable ground and equilibrium states. The method is illustrated on the example of a non-interacting field and it is shown how to pass from it within the algebra to interacting theories by relying on a rigorous local version of the interaction picture.