bluuebunny/crossref_metadata_2025_split huggingface dataset:
Plasmon localization by adatoms in gold atomic wires on Si(775)
Authors: Mamiyev Z , Tegenkamp C , Pfnür H 
Published: March 2021

Abstract
Self-organized gold chains on vicinal Si(111) surfaces represent prototype examples of quasi-one-dimensional objects that are stabilized by hybridization with Si surface states. Their plasmons contain important information about the unoccupied bandstructure close to the Fermi level. Using Si(775)–Au as an example, we report here the modifications of the plasmon dispersion by the simple atomic adatom species H and O. Using a combination of low energy electron diffraction and high-resolution electron energy loss spectroscopy, we study the interconnection between plasmonic excitation and the corresponding local surface structure. Both adsorbates do not destroy metallicity, but, similar to Si(553)–Au, atomic hydrogen enhances dimerization of the Au chains, which at small concentrations counteracts the disorder introduced by random adsorption. This effect, most likely caused by electron donation of H to the surface states, is missing in case of adsorbed oxygen, so that only the effect of disorder is observed. For both adsorbates increasing disorder as a function of adsorbate concentration finally results in plasmon localization and opening of a band gap.
Photoluminescence upconversion of 2D materials and applications
Authors: Wang Qixing , Wee Andrew T S 
Published: March 2021

Abstract
Photoluminescence (PL) upconversion is a phenomenon involving light–matter interactions, where the energy of emitted photons is higher than that of the incident photons. PL upconversion is an intriguing process in two-dimensional materials and specifically designed 2D heterostructures, which have potential upconversion applications in optoelectronic devices, bioimaging, and semiconductor cooling. In this review, we focus on the recent advances in photoluminescence upconversion in two-dimensional materials and their heterostructures. We discuss the upconversion mechanisms, applications, and future outlook of upconversion in two-dimensional materials.
Davydov Splitting, Resonance Effect and Phonon Dynamics in Chemical Vapor Deposition Grown Layered MoS2
Authors: Kumar Deepu , Singh Birender , Kumar Rahul , Kumar Mahesh , Kumar Pradeep 
Published: March 2021

Abstract
We present comprehensive temperature dependent Raman measurements for chemical vapor deposition grown horizontally aligned layered MoS2 in a temperature range of 4–330 K under a resonance condition. Our analysis of temperature dependent phonon frequency shift and linewidth suggests a finite role of three and four phonon anharmonic effect. We observe Davydov splitting of the out-of-plane (A
1g
) and in-plane (

E

2
g

1

) modes for both three layer (3L) and few layer (FL) systems. The number of Davydov splitting components are found more in FL compared to 3L MoS2, which suggests that it increases with an increasing number of layers. Further, Davydov splitting is analyzed as a function of temperature. Temperature evaluation of the Raman spectra shows that the Davydov splitting, especially for A
1g
mode, is very strong and well resolved at low temperature. We observe that A
1g
mode shows the splitting at low temperature, while

E

2
g

1

mode is split even at room temperature, which suggests a prominent role of A
1g
mode in the interlayer interaction at low temperature. Further, an almost 60-fold increase in the intensity of the phonon modes at low temperature clearly shows the temperature dependent tuning of the resonance effect.
High conductivity InAlN/GaN multi-channel two-dimensional electron gases
Authors: Sohi P , Carlin J-F , Rossell M D , Erni R , Grandjean N , Matioli E 
Published: March 2021

Abstract
In this study, we propose a novel, high-conductivity multi-channel heterostructure based on lattice-matched InAlN/GaN channels with modulation-doping-induced two-dimensional electron gases (2DEGs). To facilitate device processing, the channel period thickness was minimized while maintaining a high electron mobility in each channel. We demonstrate a 10-channel heterostructure with a period thickness of 14 nm and a total sheet resistance of 82 Ω □−1. By increasing the doping concentration in each channel, much higher carrier densities per channel were achieved, resulting in an ultra-low sheet resistance of 36 Ω □−1. Furthermore, optimizing the heterostructure design enabled high electron mobilities, up to 1530 cm2 V−1 s−1, independent of the number of channels, by secluding the 2DEG from the barrier interfaces in each channel to avoid both strong interface roughness and ionized impurity scattering. This was achieved by modulation-doping of the GaN channel and the insertion of a GaN interlayer between the InAlN barrier and the AlN spacer. This approach offers a new platform for designing high conductivity heterostructures, where the general trade-off between electron mobility and carrier density can be significantly alleviated.
Application of statistical moment method to investigate mechanical properties of yttria-stabilized zirconia
Authors: Thu Lam Le , Van Hung Vu , Thanh Hai Dang , Thi Thanh Huong Le 
Published: March 2021

Abstract
The mechanical properties of yttria-stabilized zirconia (YSZ) crystal under extreme conditions are theoretically investigated using the analytic free energy formulas derived from the statistical moment method. We calculate the elastic moduli and constants under temperature up to 2100 K and pressure up to 20 GPa using Buckingham potential. The dopant concentration, temperature, and pressure dependences of the elastic moduli and constants of YSZ crystal are studied taking into account the anharmonic effects of the lattice vibrations. Our results are in reasonable agreement with previous experiments and simulations. This approach can then be developed extensively to investigate the thermodynamic and mechanical properties of the other ceramic materials used in solid oxide fuel cells.
Asymmetry of the CMB map: local and global anomalies
Authors: Creswell James , Naselsky Pavel 
Published: March 2021

Abstract
We investigate the sources of parity asymmetry in the CMB
temperature maps using a pixel domain approach. We demonstrate that
this anomaly is mainly associated with the presence of two pairs of
high asymmetry regions. The first pair of peaks with Galactic
coordinates (l, b) = (212°, -21°) and (32°,
21°) is associated with the Northern Galactic Spur and the
direction of the dipole modulation of the power spectrum of the CMB
anisotropy. The other pair ((l, b)=(332°, -8°) and
(152°, 8°)) is located within the Galactic plane (the
Galactic Cold Spot and its antipodal partner). Similar asymmetric
peaks, but with smaller amplitudes, belong to the WMAP/Planck Cold
Spot and its partner in the Northern Galactic Spur. These local
anomalies increase the odd-multipole power to a level consistent
with Gaussian simulations. In contrast, the deficit of symmetric
peaks is accompanied by a deficit in the even-multipole power and is
the source of the parity asymmetry of the CMB temperature maps at
the level of about 3 sigma. We also evaluate the influence of the
quadrupole, which is another source of the even-multipole
deficit. If the low quadrupole is an intrinsic feature of the
theoretical model, it will reduce the significance of the parity
asymmetry to around the 2 sigma level. We also investigate the
relationship between the asymmetry of the power spectrum and the
level of the parity asymmetry in the framework of a model with
dipole modulation of a statistically uniform Gaussian signal. We
show that these two anomalies are innately linked to each other.
Influence of laser parameters on superhydrophobicity- A review
Authors: Raja R Samuel Sanjay , Selvakumar P , Babu P Dinesh , Rubasingh B Jacob , Suresh K 
Published: March 2021

Abstract
Superhydrophobicity is also known as lotus effect which makes the water to roll off and bounce when liquid droplets resting on the surface. In nature it is used by plants for self-cleaning purpose and by animals for anti-adhesion skin. The superhydrophobic surface has been mimicked and used in the field of aerospace, textiles, power line, solar cell and so on. In this review we provide the basic theories of wetting, wetting transition models of superhydrophobicity, parameters of laser beam and post processing (heat treatment only) after laser irradiation related to contact angle. Laser parameters play a vital role in producing surface topography. The surface topography may be consists of ripples, dual surface roughness on the laser textured surface. Based on the magnitude of laser parameters the different surface morphology can be obtained. The surface morphology will vary for the different laser system such femto, pico or nano second laser system. The present review aims to report the understanding of laser parameters in order to texture the expected surface structure by controlling the laser parameters.
Actuated bending of a long cantilevered glassy nematic bilayer strip: failure of the beam model
Authors: Lin Y L , He L H 
Published: March 2021

Abstract
Cantilevered long glassy nematic bilayer strips bend in response to light, and thus are attractive for actuation applications. The objective of this work is to examine whether the deformation can be predicted by the one-dimensional beam model as in usual practice. To do so, we consider a bilayer with orthogonal director orientations in the upper and lower layers and analyze its bending in the framework of the classical plate theory. We find that the deflection is much larger than that given by the beam model, because the spontaneous bending in the width direction increases the curvature along the long axis. Therefore, the one-dimensional beam model fails to describe the bending behavior of the cantilevered bilayer strips.
Diagnostic Accuracy Estimates for COVID-19 Real-Time Polymerase Chain Reaction and Lateral Flow Immunoassay Tests With Bayesian Latent-Class Models
Authors: Kostoulas Polychronis , Eusebi Paolo , Hartnack Sonja 
Published: March 2021

Abstract
Our objective was to estimate the diagnostic accuracy of real-time polymerase chain reaction (RT-PCR) and lateral flow immunoassay (LFIA) tests for coronavirus disease 2019 (COVID-19), depending on the time after symptom onset. Based on the cross-classified results of RT-PCR and LFIA, we used Bayesian latent-class models, which do not require a gold standard for the evaluation of diagnostics. Data were extracted from studies that evaluated LFIA (immunoglobulin G (IgG) and/or immunoglobulin M (IgM)) assays using RT-PCR as the reference method. The sensitivity of RT-PCR was 0.68 (95% probability interval (PrI): 0.63, 0.73). IgG/M sensitivity was 0.32 (95% PrI :0.23; 0.41) for the first week and increased steadily. It was 0.75 (95% PrI: 0.67; 0.83) and 0.93 (95% PrI: 0.88; 0.97) for the second and third weeks after symptom onset, respectively. Both tests had a high to absolute specificity, with higher point median estimates for RT-PCR specificity and narrower probability intervals. The specificity of RT-PCR was 0.99 (95% PrI: 0.98; 1.00). and the specificity of IgG/IgM was 0.97 (95% PrI: 0.92, 1.00), 0.98 (95% PrI: 0.95, 1.00) and 0.98 (95% PrI: 0.94, 1.00) for the first, second, and third weeks after symptom onset. The diagnostic accuracy of LFIA varies with time after symptom onset. Bayesian latent-class models provide a valid and efficient alternative for evaluating the rapidly evolving diagnostics for COVID-19, under various clinical settings and different risk profiles.
A comparative analysis of RNA-binding proteins binding models learned from RNAcompete, RNA Bind-n-Seq and eCLIP data
Authors: Tripto Eitamar , Orenstein Yaron 
Published: March 2021

AbstractUnderstanding post-transcriptional gene regulation is a key challenge in today’s biology. The new technologies of RNAcompete and RNA Bind-n-Seq enable the measurement of the binding intensities of one RNA-binding protein (RBP) to numerous synthetic RNA sequences in a single experiment. Recently, Van Nostrand et al. reported the results of RNA Bind-n-Seq experiments measuring binding of 78 human RBPs. Because 31 of these RBPs were also covered by RNAcompete technology, a large-scale comparison between implementations of these two in vitro technologies is now possible. Here, we assessed the similarities and differences between binding models, represented as a list of $k$-mer scores, inferred from RNAcompete and RNA Bind-n-Seq, and also measured how well these models predict in vivo binding. Our results show that RNA Bind-n-Seq- and RNAcompete-derived models agree (Pearson correlation $&gt; 0.5$) for most RBPs (23 out of 31). RNA Bind-n-Seq-derived $k$-mer scores predict RNAcompete binding measurements quite well (average Pearson correlation 0.26), and both technologies produce $k$-mer scores that achieve comparable results in predicting in vivo binding (average AUC 0.7). When inspecting RNA structural preferences inferred from the data of RNA Bind-n-Seq and RNAcompete, we observed high concordance in binding preferences. Through our study, we developed a new $k$-mer score for RNA Bind-n-Seq and extended it to include RNA structural preferences.
Estimation of Secondary Household Attack Rates for Emergent Spike L452R Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Variants Detected by Genomic Surveillance at a Community-Based Testing Site in San Francisco
Authors: Peng James , Liu Jamin , Mann Sabrina A , Mitchell Anthea M , Laurie Matthew T , Sunshine Sara , Pilarowski Genay , Ayscue Patrick , Kistler Amy , Vanaerschot Manu , Li Lucy M , McGeever Aaron , Chow Eric D , Marquez Carina , Nakamura Robert , Rubio Luis , Chamie Gabriel , Jones Diane , Jacobo Jon , Rojas Susana , Rojas Susy , Tulier-Laiwa Valerie , Black Douglas , Martinez Jackie , Naso Jamie , Schwab Joshua , Petersen Maya , Havlir Diane , DeRisi Joseph ,   IDseq Team
Published: March 2021

Abstract

Background
Sequencing of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral genome from patient samples is an important epidemiological tool for monitoring and responding to the pandemic, including the emergence of new mutations in specific communities.

Methods
SARS-CoV-2 genomic sequences were generated from positive samples collected, along with epidemiological metadata, at a walk-up, rapid testing site in the Mission District of San Francisco, California during 22 November to 1 December, 2020, and 10–29 January 2021. Secondary household attack rates and mean sample viral load were estimated and compared across observed variants.

Results
A total of 12 124 tests were performed yielding 1099 positives. From these, 928 high-quality genomes were generated. Certain viral lineages bearing spike mutations, defined in part by L452R, S13I, and W152C, comprised 54.4% of the total sequences from January, compared to 15.7% in November. Household contacts exposed to the “California” or “West Coast” variants (B.1.427 and B.1.429) were at higher risk of infection compared to household contacts exposed to lineages lacking these variants (0.36 vs 0.29, risk ratio [RR] = 1.28; 95% confidence interval [CI]: 1.00–1.64). The reproductive number was estimated to be modestly higher than other lineages spreading in California during the second half of 2020. Viral loads were similar among persons infected with West Coast versus non-West Coast strains, as was the proportion of individuals with symptoms (60.9% vs 64.3%).

Conclusions
The increase in prevalence, relative household attack rates, and reproductive number are consistent with a modest transmissibility increase of the West Coast variants.
Summary: We observed a growing prevalence and modestly elevated attack rate for “West Coast” severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants in a community testing setting in San Francisco during January 2021, suggesting its modestly higher transmissibility.
Isolation and characterization of bacteriophages from the human skin microbiome that infectStaphylococcus epidermidis
Authors: Valente Luca G , Pitton Melissa , Fürholz Monika , Oberhaensli Simone , Bruggmann Rémy , Leib Stephen L , Jakob Stephan M , Resch Grégory , Que Yok-Ai , Cameron David R 
Published: March 2021

ABSTRACTPhage therapy might be a useful approach for the treatment of nosocomial infections; however, only few lytic phages suitable for this application are available for the opportunistic pathogen, Staphylococcus epidermidis. In the current study, we developed an efficient method to isolate bacteriophages present within the human skin microbiome, by using niche-specific S. epidermidis as the host for phage propagation. Staphylococcus epidermidis was identified on the forehead of 92% of human subjects tested. These isolates were then used to propagate phages present in the same skin sample. Plaques were observable on bacterial lawns in 46% of the cases where S. epidermidis was isolated. A total of eight phage genomes were genetically characterized, including the previously described phage 456. A total of six phage sequences were unique, and spanned each of the major staphylococcal phage families; Siphoviridae (n = 3), Podoviridae (n = 1) and Myoviridae (n = 2). One of the myoviruses (vB_SepM_BE06) was identified on the skin of three different humans. Comparative analysis identified novel genes including a putative N-acetylmuramoyl-L-alanine amidase gene. The host-range of each unique phage was characterized using a panel of diverse staphylococcal strains (n = 78). None of the newly isolated phages infected more than 52% of the S. epidermidis strains tested (n = 44), and non-S. epidermidis strains where rarely infected, highlighting the narrow host-range of the phages. One of the phages (vB_SepM_BE04) was capable of killing staphylococcal cells within biofilms formed on polyurethane catheters. Uncovering a richer diversity of available phages will likely improve our understanding of S. epidermidis-phage interactions, which will be important for future therapy.
Insulin Restriction, Emotion Dysregulation, and Depressive Symptoms in Late Adolescents with Diabetes
Authors: Beam Aislinn B , Wiebe Deborah J , Berg Cynthia A 
Published: March 2021

Abstract

Objective
Insulin restriction occurs when an individual takes less insulin than recommended and is a serious concern for those with diabetes. General insulin restriction (IR) and insulin restriction for weight control (IRWC) have not been clearly distinguished in the literature, creating inconsistencies and limited understanding of factors that underlie this behavior. We examined whether these are distinct, and how emotion dysregulation and depressive symptoms relate to both forms of insulin restriction during late adolescence.

Methods
As part of a larger study, late adolescents (ages 17–18) with type 1 diabetes (N = 236) completed measures of depressive symptoms (Center for Epidemiologic Studies—Depression Scale [CES-D]), facets of Difficulties In Emotion Regulation Scale (DERS), diabetes self-management behaviors, insulin restriction, and hemoglobin A1c (HbA1c).

Results
IR and IRWC were not significantly associated with each other. IR was associated with self-management behaviors but not HbA1c, whereas the opposite was true for IRWC. All DERS subscales (M = 10.60–16.73) and CES-D (M = 16.56) were correlated with greater IRWC; CES-D and all but one DERS subscale were correlated with IR. Covariation with CES-D explained associations between DERS and IRWC. CES-D moderated associations with IR, indicating most subscales of the DERS were associated with IR only when CES-D was higher.

Conclusion
Emotion dysregulation and depressive symptoms are important correlates of the dangerous behavior of insulin restriction, but function differently when insulin is restricted specifically for weight control versus nonspecified reasons. Future research to understand these underlying processes will be necessary to develop emotion-based theory and evidence-based interventions for this dangerous behavior.
Examining transfer of rights surplus—Brazilian case
Authors: David Olavo Bentes , Castro de Carvalho Bruno Eustáquio F , Braga Maria Amélia , Isfer Renata Beckert , Esteves Heloísa Borges , Regra Andre 
Published: March 2021

ABSTRACT
At the end of 2019, Brazil realized an enormous offshore premium assets under the ‘Transfer of Rights’ (TOR) regime. It was a key milestone that later set in motion the largest oil bidding round in history, according to the Brazilian authorities. TOR is a regime that deviates from the general rule of holding bids prior to the granting of oil & natural gas E&P rights. No legal dispositive was able to predict the possibility which impose Brazilian government design an innovative portfolio of regulations in order to achieve high productivity and profitability. A new regulatory framework was created to support the decision makers. Transference of Rights Surplus came to lead with surplus volume bidding rounds. Future biddings will take place at another level of institutional maturity to deal with the situation, and takes advantage of the learning and tools already developed. It is expected that the changes being discussed will bring attractiveness to the offer of the areas in the current scenario.
ℋ-Colouring Dichotomy in Proof Complexity
Authors: Gaysin Azza 
Published: March 2021

Abstract
The $\mathcal {H}$-colouring problem for undirected simple graphs is a computational problem from a huge class of the constraint satisfaction problems (CSPs): an $\mathcal {H}$-colouring of a graph $\mathcal {G}$ is just a homomorphism from $\mathcal {G}$ to $\mathcal {H}$ and the problem is to decide for fixed $\mathcal {H}$, given $\mathcal {G}$, if a homomorphism exists or not. The dichotomy theorem for the $\mathcal {H}$-colouring problem was proved by Hell and Nešetřil (1990, J. Comb. Theory Ser. B, 48, 92–110) (an analogous theorem for all CSPs was recently proved by Zhuk (2020, J. ACM, 67, 1–78) and Bulatov (2017, FOCS, 58, 319–330)), and it says that for each $\mathcal {H}$, the problem is either $p$-time decidable or $NP$-complete. Since negations of unsatisfiable instances of CSP can be expressed as propositional tautologies, it seems to be natural to investigate the proof complexity of CSP. We show that the decision algorithm in the $p$-time case of the $\mathcal {H}$-colouring problem can be formalized in a relatively weak theory and that the tautologies expressing the negative instances for such $\mathcal {H}$ have polynomial proofs in propositional proof system $R^*(log)$, a mild extension of resolution. In fact, when the formulas are expressed as unsatisfiable sets of clauses, they have $p$-size resolution proofs. To establish this, we use a well-known connection between theories of bounded arithmetic and propositional proof systems. This upper bound follows also from a different construction in [1]. We complement this result by a lower bound result that holds for many weak proof systems for a special example of $NP$-complete case of the $\mathcal {H}$-colouring problem, using known results about the proof complexity of the pigeonhole principle. The main goal of our work is to start the development of some of the theories beyond the CSP dichotomy theorem in bounded arithmetic. We aim eventually—in a subsequent work—to formalize in such a theory the soundness of Zhuk’s algorithm, extending the upper bound proved here from undirected simple graphs to the general case of directed graphs in some logical calculi.