bluuebunny/crossref_metadata_2025_split huggingface dataset:
Elliptic Curves in Hyper-Kähler Varieties
Authors: Nesterov Denis , Oberdieck Georg 
Published: January 2020

Abstract
We show that the moduli space of elliptic curves of minimal degree in a general Fano variety of lines of a cubic four-fold is a non-singular curve of genus $631$. The curve admits a natural involution with connected quotient. We find that the general Fano contains precisely $3,780$ elliptic curves of minimal degree with fixed (general) $j$-invariant. More generally, we express (modulo a transversality result) the enumerative count of elliptic curves of minimal degree in hyper-Kähler varieties with fixed $j$-invariant in terms of Gromov–Witten invariants. In $K3^{[2]}$-type this leads to explicit formulas of these counts in terms of modular forms.
Rapid detection of plasmid-mediated high-level tigecycline resistance in Escherichia coli and Acinetobacter spp
Authors: Cui Ze-Hua , Ni Wei-Na , Tang Tian , He Bing , Zhong Zi-Xing , Fang Liang-Xing , Chen Liang , Chen Chong , Cui Chao-Yue , Liu Ya-Hong , Liao Xiao-Ping , Sun Jian 
Published: January 2020

Abstract

Objectives
The emergence and spread of plasmid-encoded tet(X3/X4) genes that confer high-level tigecycline and eravacycline resistance in Escherichia coli and Acinetobacter spp. pose serious threats to human and animal health. We developed a rapid and robust assay to detect Tet(X3/X4) in Gram-negative bacteria based on eravacycline degradation by the presence of the Tet(X) enzyme in the test strain.

Methods
This tetracycline inactivation method (TIM) is based on the degradation of eravacycline by the Tet(X3/X4)-producing strain, which results in reduced eravacycline activity against an acid-producing thermophile Bacillus stearothermophilus indicator strain. For Tet(X)-negative strains, eravacycline retains its antimicrobial activity. Coupled with a pH-sensitive dye (bromocresol purple), the reduced colorimetric inhibition zone can be measured to determine the production of Tet(X3/X4). One hundred and eighteen isolates, including 30 tet(X4)-positive E. coli, 30 tet(X3)-positive Acinetobacter spp. and 58 tet(X)-negative E. coli and Acinetobacter spp., were examined to evaluate the performance of this TIM.

Results
The sensitivity and specificity for E. coli carrying tet(X4) was 96.7% and 100%, respectively, and for Acinetobacter spp. carrying tet(X3) both were 100%. The TIM assay can be completed within 6.5 h.

Conclusions
The TIM is a simple, rapid and cost-effective method for the detection of plasmid-mediated high-level tigecycline resistance in E. coli and Acinetobacter spp.
Proposed Plasma Ammonia Reference Intervals in a Reference Group of Hospitalized Term and Preterm Neonates
Authors: Madigan Theresa , Block Darci R , Carey William A , Kaemingk Bethany D , Patel Robin 
Published: January 2020

AbstractBackgroundPlasma ammonia is commonly measured in the diagnostic evaluation of hospitalized newborns, but reference values are not well defined.MethodsWe prospectively enrolled newborns admitted to the level III/IV neonatal intensive care unit and level II intermediate special care nursery from January 2017 to January 2018. Infants with inborn errors of metabolism or liver disease were excluded. Plasma ammonia concentrations were measured once within the first week of life and evaluated by sex, gestational age, timing of the draw, blood collection method, and type of nutrition. Reference intervals were calculated.Results127 neonates were included; one third (34%) were term infants born at ≥37 weeks gestation, and two thirds (66%) were born preterm at &lt;37 weeks gestation. Median plasma ammonia concentrations were 32 μmol/L (range &lt;10 to 86 μmol/L). Median ammonia concentrations were higher among preterm compared to term infants (35 vs. 28 μmol/L, p = 0.0119), and term female compared to term male infants (34 vs. 26 μmol/L, p = 0.0228). There was no difference in median ammonia concentrations between female and male preterm infants, based on gestational age within the preterm group, timing of the blood draw, presence of hyperbilirubinemia, blood collection method, or type of nutritional intake.ConclusionsPlasma ammonia concentrations among newborns are higher than the expected adult concentrations and may vary by gestational age and sex. Blood collection method, type of nutrition, hyperbilirubinemia, and timing of the draw do not impact concentrations. We propose a reference limit of ≤82 μmol/L for newborns less than one week of age.
Chemical Comparison of Ophiopogonis radix and Liriopes radix Based on Quantitative Analysis of Multiple Components by HPLC Coupled with Electrospray Ionization Tandem Triple Quadrupole Mass Spectrometry
Authors: Luo Heng , Ming Liang-Shan , Tong Tian-Tian , Tang Yan , Yang Jun , Shen Li , Cui Hongmei , Yang Andong , Huang Hao 
Published: January 2020

Abstract

Background
Ophiopogonis radix and Liriopes radix are well known for the treatment of dry coughs and phthisis. Liriopes radix is occasionally used as a substitute for Ophiopogonis radix in various prescriptions due to the extremely similar pharmacological activities and clinical efficacies, but they are regarded as two different remedies in the Chinese Pharmacopoeia. Accordingly, the establishment of a reliable analytical approach for the discrimination and quality evaluation of Ophiopogonis and Liriopes is required.

Objective
To establish a simple, accurate, and reliable method that can simultaneously determine multiple components in Ophiopogonis radix and Liriopes radix. To comprehensively compare the chemical compositions of the two herbs and find markers for discrimination and quality assessments.

Method
An HPLC-ESI-triple quadrupole (QQQ)-MS/MS method was developed for simultaneous characterization and quantification of chemical components in the two herbs. The results were further analyzed by PLS discriminant analysis to provide more information about the chemical differences, as well as to evaluate the quality of each sample.

Results
A total of 23 compounds have been characterized and quantified in 31 batches of herbs from different geographical regions, among which liriopesides B, sprengerinin A, ophiopogonin B, and ophiopogonanone E contribute mostly. The contents of homoisoflavonoids were much higher in Ophiopogonis radix than in Liriopes radix, but the levels of steroidal saponins followed a contrary trend.

Conclusions
Simultaneous determination of multiple components by HPLC-QQQ-MS/MS coupled with chemometrics analysis is an acceptable strategy to evaluate and control the quality of Ophiopogonis radix and Liriope radix.

Highlights
Simultaneous determination of 12 steroidal saponins and 11 homoisoflavonoids in both Ophiopogonis radix and Liriope radix by using HPLC-QQQ-MS/MS in positive ion mode, as well as the quality control study.
Parents’ Perspectives on Their Child’s Music Therapy: A Qualitative Study
Authors: Annesley Luke , Curtis-Tyler Katherine , McKeown Eamonn 
Published: January 2020

AbstractThis qualitative study explored parents’ perspectives on their child receiving individual music therapy in a community setting in an NHS service in London, UK. Parents of children aged 6–11 receiving or recently discharged from music therapy took part. Data were collected through semi-structured interviews which were digitally recorded, transcribed, and analyzed following procedures of inductive thematic analysis. Music therapy was generally perceived to provide a nurturing environment for children, and communication with music therapists was mostly experienced as helpful, but with some perceived challenges. Parents perceived positive outcomes of music therapy, including children becoming calmer and engaging more with musical activities at home. Understanding of music therapy was perceived as an evolving process for parents. Some parents described a need for more information prior to music therapy. The findings of this study broadly support the model in the service of working with children aged 6–11 without parents generally present during sessions. However, there were indications that, for some families, a more flexible approach might be beneficial for the child. Participants’ commentaries on perceived outcomes for children indicate potential for intervention studies investigating the impact of music therapy, while broader perceptions of the value of music therapy indicate a need for studies exploring reasons for effectiveness.
Duplication and functional divergence of a calcium sensor in the Brassicaceae
Authors: Monihan Shea M , Magness Courtney A , Ryu Choong-Hwan , McMahon Michelle M , Beilstein Mark A , Schumaker Karen S 
Published: January 2020

AbstractThe presence of varied numbers of CALCINEURIN B-LIKE10 (CBL10) calcium sensor genes in species across the Brassicaceae and the demonstrated role of CBL10 in salt tolerance in Arabidopsis thaliana and Eutrema salsugineum provided a unique opportunity to determine if CBL10 function is modified in different species and linked to salt tolerance. Salinity effects on species growth and cross-species complementation were used to determine the extent of conservation and divergence of CBL10 function in four species representing major lineages within the core Brassicaceae (A. thaliana, E. salsugineum, Schrenkiella parvula, and Sisymbrium irio) as well as the first diverging lineage (Aethionema arabicum). Evolutionary and functional analyses indicate that CBL10 duplicated within expanded lineage II of the Brassicaceae and that, while portions of CBL10 function are conserved across the family, there are species-specific variations in CBL10 function. Paralogous CBL10 genes within a species diverged in expression and function probably contributing to the maintenance of the duplicated gene pairs. Orthologous CBL10 genes diverged in function in a species-specific manner, suggesting that functions arose post-speciation. Multiple CBL10 genes and their functional divergence may have expanded calcium-mediated signaling responses and contributed to the ability of certain members of the Brassicaceae to maintain growth in salt-affected soils.
Antifungal activity of promethazine and chlorpromazine against planktonic cells and biofilms of Cryptococcus neoformans/Cryptococcus gattii complex species
Authors: Brilhante Raimunda Sâmia Nogueira , Gotay Wilker Jose Perez , Pereira Vandbergue Santos , de Oliveira Jonathas Sales , Pereira-Neto Waldemiro Aquino , Castelo-Branco Débora de Souza Collares Maia , Cordeiro Rossana de Aguiar , Sidrim José Júlio Costa , Rocha Marcos Fábio Gadelha 
Published: January 2020

Abstract
Cryptococcus neoformans/Cryptococcus gattii are fungal pathogens that affect the central nervous system, mainly in immunocompromised individuals. Due to the limited pharmacological arsenal available for the treatment of cryptococcosis associated with cases of antifungal resistance of Cryptococcus spp. reported in some studies, the search for new compounds with antifungal potential becomes relevant. Thus, the objective of this study was to evaluate the inhibitory effect of phenothiazines (promethazine and chlorpromazine) on C. neoformans/C. gattii planktonic cells and biofilms. In vitro planktonic susceptibility testing was performed using the broth microdilution assay. The effect of phenothiazines was evaluated against biofilm formation and mature Cryptococcus biofilms. Biofilm morphology and ultrastructure were also evaluated by scanning electron microscopy. Promethazine and chlorpromazine showed antifungal activity against planktonic cells, with minimum inhibitory concentrations of 8–32 μg/ml and 4–16 μg/ml, respectively. As for biofilm formation, phenothiazines reduced biomass by 60% and metabolic activity by 90% at 64 μg/ml; while in mature biofilms, reductions of 85% and 90% in biomass and metabolic activity, respectively, were observed at 1024 μg/ml. Promethazine and chlorpromazine were also able to disrupt and fragment biofilms. In conclusion, promethazine and chlorpromazine have antifungal activity against planktonic cells and biofilms of Cryptococcus spp. These data show the potential of promethazine and chlorpromazine as antibiofilm drugs.
Redshift evolution of the Fundamental Plane relation in the IllustrisTNG simulation
Authors: Lu Shengdong , Xu Dandan , Wang Yunchong , Mao Shude , Ge Junqiang , Springel Volker , Wang Yuan , Vogelsberger Mark , Naiman Jill , Hernquist Lars 
Published: January 2020

ABSTRACT
We investigate the Fundamental Plane (FP) evolution of early-type galaxies in the IllustrisTNG-100 simulation (TNG100) from redshift z = 0 to z = 2. We find that a tight plane relation already exists as early as z = 2. Its scatter stays as low as ∼0.08 dex across this redshift range. Both slope parameters b and c (where R ∝ σbIc with R, σ, and I being the typical size, velocity dispersion, and surface brightness) of the plane evolve mildly since z = 2, roughly consistent with observations. The FP residual $\rm Res$ ($\equiv \, a\, +\, b\log \sigma \, +\, c\log I\, -\, \log R$, where a is the zero-point of the FP) is found to strongly correlate with stellar age, indicating that stellar age can be used as a crucial fourth parameter of the FP. However, we find that 4c + b + 2 = δ, where δ ∼ 0.8 for FPs in TNG, rather than zero as is typically inferred from observations. This implies that a tight power-law relation between the dynamical mass-to-light ratio Mdyn/L and the dynamical mass Mdyn (where Mdyn ≡ 5σ2R/G, with G being the gravitational constant) is not present in the TNG100 simulation. Recovering such a relation requires proper mixing between dark matter and baryons, as well as star formation occurring with correct efficiencies at the right mass scales. This represents a powerful constraint on the numerical models, which has to be satisfied in future hydrodynamical simulations.
Are the carriers of diffuse interstellar bands and extended red emission the same?
Authors: Lai Thomas S-Y , Witt Adolf N , Alvarez Carlos , Cami Jan 
Published: January 2020

ABSTRACT
We report the first spectroscopic observations of a background star seen through the region between the ionization front and the dissociation front of the nebula IC 63. This photodissociation region (PDR) exhibits intense extended red emission (ERE) attributed to fluorescence by large molecules/ions. We detected strong diffuse interstellar bands (DIB) in the stellar spectrum, including an exceptionally strong and broad DIB at λ4428. The detection of strong DIBs in association with ERE could be consistent with the suggestion that the carriers of DIBs and ERE are identical. The likely ERE process is recurrent fluorescence, enabled by inverse internal conversions from highly excited vibrational levels of the ground state to low-lying electronic states with subsequent transitions to ground. This provides a path to rapid radiative cooling for molecules/molecular ions, greatly enhancing their ability to survive in a strongly irradiated environment. The ratio of the equivalent widths (EWs) of DIBs λ5797 and λ5780 in IC 63 is the same as that observed in the low-density interstellar medium with ultraviolet (UV) interstellar radiation fields (ISRF) weaker by at least two orders of magnitude. This falsifies suggestions that the ratio of these two DIBs can serve as a measure of the UV strength of the ISRF. Observations of the nebular spectrum of the PDR of IC 63 at locations immediately adjacent to where DIBs were detected failed to reveal any presence of sharp emission features seen in the spectrum of the Red Rectangle nebula. This casts doubts upon proposals that the carriers of these features are the same as those of DIBs seen at slightly shorter wavelengths.
A SCUBA-2 850 μm survey of heavily reddened quasars at z ∼ 2
Authors: Wethers Clare F , Banerji Manda , Hewett Paul C , Jones Gareth C 
Published: January 2020

ABSTRACT
We present new 850 μm SCUBA-2 observations for a sample of 19 heavily reddened Type-I quasars at redshifts z ∼ 2 with dust extinctions of AV ≃ 2–6 mag. Three of the 19 quasars are detected at &gt;3σ significance corresponding to an 850 μm flux-limit of ≳4.8 mJy. Assuming the 850 μm flux is dominated by dust heating due to star formation, very high star formation rates (SFR) of ∼2500–4500 M⊙ yr−1 in the quasar host galaxies are inferred. Even when considering a large contribution to the 850 μm flux from dust heated by the quasar itself, significant SFRs of ∼600–1500 M⊙ yr−1 are nevertheless inferred for two of the three detected quasars. We stack the remaining 16 heavily reddened quasars and derive an average 3σ upper limit on the SFRs in these quasar host galaxies of &lt;880 M⊙ yr−1. The number counts of sub-mm galaxies in the total survey area (134.3 arcmin2) are consistent with predictions from blank-field surveys. There are, however, individual quasars where we find evidence for an excess of associated sub-mm galaxies. For two quasars, higher spatial resolution and spectroscopic ALMA observations confirm the presence of an excess of sub-mm sources. We compare the 850 μm detection rate of our quasars to both unobscured, ultraviolet luminous quasars as well as the much more obscured population of mid-infrared luminous Hot Dust Obscured Galaxies (HotDOGs). When matched by luminosity and redshift, we find no significant differences in the 850 μm flux densities of these various quasar populations given the current small sample sizes.
Simulations and symmetries
Authors: Modi Chirag , Chen Shi-Fan , White Martin 
Published: January 2020

ABSTRACT
We investigate the range of applicability of a model for the real-space power spectrum based on N-body dynamics and a (quadratic) Lagrangian bias expansion. This combination uses the highly accurate particle displacements that can be efficiently achieved by modern N-body methods with a symmetries-based bias expansion which describes the clustering of any tracer on large scales. We show that at low redshifts, and for moderately biased tracers, the substitution of N-body-determined dynamics improves over an equivalent model using perturbation theory by more than a factor of two in scale, while at high redshifts and for highly biased tracers the gains are more modest. This hybrid approach lends itself well to emulation. By removing the need to identify haloes and subhaloes, and by not requiring any galaxy-formation-related parameters to be included, the emulation task is significantly simplified at the cost of modelling a more limited range in scale.
A multiwavelength study of spiral structure in galaxies. I. General characteristics in the optical
Authors: Savchenko Sergey , Marchuk Alexander , Mosenkov Aleksandr , Grishunin Konstantin 
Published: January 2020

ABSTRACT
Different spiral generation mechanisms are expected to produce different morphological and kinematic features. In this first paper in a series, we carefully study the parameters of spiral structure in 155 face-on spiral galaxies, selected from the Sloan Digital Sky Survey, in the three gri bands. We use a method for deriving a set of parameters of spiral structure, such as the width of the spiral arms, their fraction to the total galaxy luminosity, and their colour, which have not been properly studied before. Our method is based on an analysis of a set of photometric cuts perpendicular to the direction of a spiral arm. Based on the results of our study, we compare the main three classes of spirals: grand design, multi-armed, and flocculent. We conclude that: (i) for the vast majority of galaxies (86 per cent), we observe an increase of their arm width with Galactocentric distance; (ii) more luminous spirals in grand design galaxies exhibit smaller variations of the pitch angle with radius than those in less luminous grand design spirals; (iii) grand design galaxies show less difference between the pitch angles of individual arms than multi-armed galaxies. Apart from these distinctive features, all three spiral classes do not differ significantly by their pitch angle, arm width, width asymmetry, and environment. Wavelength dependence is found only for the arm fraction. Therefore, observationally we find no strong difference (except for the view and number of arms) between grand design, multi-armed, and flocculent spirals in the sample galaxies.
On the injection of relativistic electrons in the jet of 3C 279
Authors: Hu Wen , Yan Dahai , Dai Benzhong , Zeng Wei , Hu Qianglin 
Published: January 2020

ABSTRACTThe acceleration of electrons in 3C 279 is investigated through analysing the injected electron energy distribution (EED) in a time-dependent synchrotron self-Compton+external Compton emission model. In this model, it is assumed that relativistic electrons are continuously injected into the emission region, and the injected EED [$Q_{\rm e}^\prime (\gamma ^\prime)$] follows a single power-law form with low- and high-energy cut-offs $\rm \gamma _{min}^{\prime }$ and $\rm \gamma _{max}^{\prime }$, respectively, and the spectral index n, i.e. $Q_{\rm e}^\prime (\gamma ^\prime)\propto \gamma ^{\prime -n}$. This model is applied to 14 quasi-simultaneous spectral energy distributions of 3C 279. The Markov Chain Monte Carlo (MCMC)-fitting technique is performed to obtain the best-fitting parameters and the uncertainties on the parameters. The results show that the injected EED is well constrained in each state. The value of n is in the range of 2.5–3.8, which is larger than that expected by the classic non-relativistic shock acceleration. However, the large value of n can be explained by the relativistic oblique shock acceleration. The flaring activity seems to be related to an increased acceleration efficiency, reflected in an increased $\gamma ^{\prime }_{\rm min}$ and electron injection power.
Altered expression of DNA damage repair genes in the brain tissue of mice conceived by in vitro fertilization
Authors: Hu Minhao , Lou Yiyun , Liu Shuyuan , Mao Yuchan , Le Fang , Wang Liya , Li Lejun , Wang Qijing , Li Hongping , Lou Hangying , Wang Ning , Jin Fan 
Published: January 2020

Abstract
Our previous study revealed a higher incidence of gene dynamic mutation in newborns conceived by IVF, highlighting that IVF may be disruptive to the DNA stability of IVF offspring. However, the underlying mechanisms remain unclear. The DNA damage repair system plays an essential role in gene dynamic mutation and neurodegenerative disease. To evaluate the long-term impact of IVF on DNA damage repair genes, we established an IVF mouse model and analyzed gene and protein expression levels of MSH2, MSH3, MSH6, MLH1, PMS2, OGG1, APEX1, XPA and RPA1 and also the amount of H2AX phosphorylation of serine 139 which is highly suggestive of DNA double-strand break (γH2AX expression level) in the brain tissue of IVF conceived mice and their DNA methylation status using quantitative real-time PCR, western blotting and pyrosequencing. Furthermore, we assessed the capacity of two specific non-physiological factors in IVF procedures during preimplantation development. The results demonstrated that the expression and methylation levels of some DNA damage repair genes in the brain tissue of IVF mice were significantly changed at 3 weeks, 10 weeks and 1.5 years of age, when compared with the in vivo control group. In support of mouse model findings, oxygen concentration of in vitro culture environment was shown to have the capacity to modulate gene expression and DNA methylation levels of some DNA damage repair genes. In summary, our study indicated that IVF could bring about long-term alterations of gene and protein expression and DNA methylation levels of some DNA damage repair genes in the brain tissue and these alterations might be resulted from the different oxygen concentration of culture environment, providing valuable perspectives to improve the safety and efficiency of IVF at early embryonic stage and also throughout different life stages.