bluuebunny/crossref_metadata_2025_split huggingface dataset:
Partial Diploidization of Meiosis in Autotetraploid Arabidopsis thaliana
Authors: Santos J L , Alfaro D , Sanchez-Moran E , Armstrong S J , Franklin F C H , Jones G H 
Published: April 2021

Abstract
Meiosis was analyzed cytogenetically in autotetraploids of Arabidopsis, including both established lines and newly generated autotetraploid plants. Fluorescent in situ hybridization with 5S and 45S rDNA probes was used to identify the different chromosomes at metaphase I of meiosis. Multivalents were observed frequently in all the lines analyzed, but there were significant differences in multivalent frequency not only between the newly generated tetraploids and the established lines but also among the different established lines. The new tetraploids showed high multivalent frequencies, exceeding the theoretical 66.66% predicted by the simple random-end pairing model, in some cases significantly, thus indicating that Arabidopsis autotetraploids have more than two autonomous pairing sites per chromosome, despite their small sizes. The established lines showed fewer multivalents than the new autotetraploids did, but the extent of this reduction was strongly line and chromosome dependent. One line in particular showed a large reduction in multivalents and a concomitant increase in bivalents, while the other lines showed lesser reductions in multivalents. The reduction in multivalents was not uniformly distributed across chromosomes. The smaller chromosomes, especially chromosomes 2 and 4, showed the most marked reductions while the largest chromosome (1) showed virtually no reduction compared to the new tetraploids. It is concluded that the established autotetraploid lines have undergone a partial diploidization of meiosis, but not necessarily genetical diploidization, since their creation. Possible mechanisms for the resulting change in meiotic chromosome behavior are discussed.
Preclinical Testing of Vaccines and Therapeutics for Gonorrhea in Female Mouse Models of Lower and Upper Reproductive Tract Infection
Authors: Connolly Kristie L , Pilligua-Lucas Michelle , Gomez Carolina , Costenoble-Caherty Allison C , Soc Anthony , Underwood Knashka , Macintyre Andrew N , Sempowski Gregory D , Jerse Ann E 
Published: April 2021

Abstract
Murine models of Neisseria gonorrhoeae lower reproductive tract infection are valuable systems for studying N. gonorrhoeae adaptation to the female host and immune responses to infection. These models have also accelerated preclinical testing of candidate therapeutic and prophylactic products against gonorrhea. However, because N. gonorrhoeae infection is restricted to the murine cervicovaginal region, there is a need for an in vivo system for translational work on N. gonorrhoeae pelvic inflammatory disease (PID). Here we discuss the need for well-characterized preclinical upper reproductive tract infection models for developing candidate products against N. gonorrhoeae PID, and report a refinement of the gonorrhea mouse model that supports sustained upper reproductive tract infection. To establish this new model for vaccine testing, we also tested the licensed meningococcal 4CMenB vaccine, which cross-protects against murine N. gonorrhoeae lower reproductive tract infection, for efficacy against N. gonorrhoeae in the endometrium and oviducts following transcervical or vaginal challenge.
Evaluating resampling methods and structured features to improve fall incident report identification by the severity level
Authors: Liu Jiaxing , Wong Zoie S Y , So H Y , Tsui Kwok Leung 
Published: April 2021

Abstract

Objective
This study aims to improve the classification of the fall incident severity level by considering data imbalance issues and structured features through machine learning.

Materials and Methods
We present an incident report classification (IRC) framework to classify the in-hospital fall incident severity level by addressing the imbalanced class problem and incorporating structured attributes. After text preprocessing, bag-of-words features, structured text features, and structured clinical features were extracted from the reports. Next, resampling techniques were incorporated into the training process. Machine learning algorithms were used to build classification models. IRC systems were trained, validated, and tested using a repeated and randomly stratified shuffle-split cross-validation method. Finally, we evaluated the system performance using the F1-measure, precision, and recall over 15 stratified test sets.

Results
The experimental results demonstrated that the classification system setting considering both data imbalance issues and structured features outperformed the other system settings (with a mean macro-averaged F1-measure of 0.733). Considering the structured features and resampling techniques, this classification system setting significantly improved the mean F1-measure for the rare class by 30.88% (P value &lt; .001) and the mean macro-averaged F1-measure by 8.26% from the baseline system setting (P value &lt; .001). In general, the classification system employing the random forest algorithm and random oversampling method outperformed the others.

Conclusions
Structured features provide essential information for categorizing the fall incident severity level. Resampling methods help rebalance the class distribution of the original incident report data, which improves the performance of machine learning models. The IRC framework presented in this study effectively automates the identification of fall incident reports by the severity level.
Neuroblastoma Screening at 1 Year of Age: The Final Results of a Controlled Trial
Authors: Berthold Frank , Spix Claudia , Erttmann Rudolf , Hero Barbara , Michaelis Joerg , Treuner Joern , Ernst Angela , Schilling Freimut H 
Published: April 2021

Abstract

Background
Neuroblastoma screening aims to reduce neuroblastoma-related mortality. A controlled trial showed no reduction in stage 4 disease incidence and preliminary mortality data. This article presents epidemiologic and clinical data 20 years after cessation of the screening program.

Methods
The patients with detected disease in the screening area were compared with the clinically diagnosed patients in the control area and in the prestudy and poststudy cohorts. All statistical tests were 2-sided.

Results
The cumulative incidence for children aged 1 to 6 years in the birth study cohorts (1994-1999) in the screening arm was 13.4 cases per 100 000 births (95% confidence interval [CI] = 12.2 to 14.6) based on 61.2% of screening participants and 38.8% of nonparticipants. Screening participants had a cumulative incidence of 15.7 (95% CI = 14.0 to 17.4) per 100 000 births. The cumulative incidence in the contemporary control cohort was 9.3 (95% CI = 8.2 to 10.3) per 100 000 births, 7.6 (95% CI = 6.8 to 8.4) in the prestudy cohort, and 8.1 (95% CI = 7.4 to 8.9) in the poststudy cohort from 2000 to 2004 (P &lt; .001 each). The increased incidence in the screening cohort was restricted to stages 1 through 3, while stage 4 incidence was not reduced. The cumulative mortality for deaths within 10 years from diagnosis and per 100 000 births remained unchanged. Patients with stage 4 disease detected by screening had better biological characteristics and an improved outcome compared with those stage 4 cases not detected by screening.

Conclusions
Neuroblastoma screening at 1 year of age reduced neither stage 4 incidence nor neuroblastoma mortality and was affected by overdiagnosis, leading to unnecessary treatment. A few screening-detected stage 4 cases represent a biologically interesting subgroup but do not change the recommendation to close the “catecholamine-based neuroblastoma screening book.”
Can improved canopy light transmission ameliorate loss of photosynthetic efficiency in the shade? An investigation of natural variation inSorghum bicolor
Authors: Jaikumar Nikhil S , Stutz Samantha S , Fernandes Samuel B , Leakey Andrew D B , Bernacchi Carl J , Brown Patrick J , Long Stephen P 
Published: April 2021

AbstractPrevious studies have found that maximum quantum yield of CO2 assimilation (Φ CO2,max,app) declines in lower canopies of maize and miscanthus, a maladaptive response to self-shading. These observations were limited to single genotypes, leaving it unclear whether the maladaptive shade response is a general property of this C4 grass tribe, the Andropogoneae. We explored the generality of this maladaptation by testing the hypothesis that erect leaf forms (erectophiles), which allow more light into the lower canopy, suffer less of a decline in photosynthetic efficiency than drooping leaf (planophile) forms. On average, Φ CO2,max,app declined 27% in lower canopy leaves across 35 accessions, but the decline was over twice as great in planophiles than in erectophiles. The loss of photosynthetic efficiency involved a decoupling between electron transport and assimilation. This was not associated with increased bundle sheath leakage, based on 13C measurements. In both planophiles and erectophiles, shaded leaves had greater leaf absorptivity and lower activities of key C4 enzymes than sun leaves. The erectophile form is considered more productive because it allows a more effective distribution of light through the canopy to support photosynthesis. We show that in sorghum, it provides a second benefit, maintenance of higher Φ CO2,max,app to support efficient use of that light resource.
Melatonin promotes Arabidopsis primary root growth in an IAA-dependent manner
Authors: Yang Li , You Jun , Li Jinzhu , Wang Yanping , Chan Zhulong 
Published: April 2021

Abstract
Melatonin has been characterized as a growth regulator in plants. Melatonin shares tryptophan as the precursor with the auxin indole-3-acetic acid (IAA), but the interplay between melatonin and IAA remains controversial. In this study, we aimed to dissect the relationship between melatonin and IAA in regulating Arabidopsis primary root growth. We observed that melatonin concentrations ranging from 10–9 to 10–6 M functioned as IAA mimics to promote primary root growth in Arabidopsis wild type, as well as in pin-formed (pin) single and double mutants. Transcriptome analysis showed that changes in gene expression after melatonin and IAA treatment were moderately correlated. Most of the IAA-regulated genes were co-regulated by melatonin, indicating that melatonin and IAA regulated a similar subset of genes. Melatonin partially rescued primary root growth defects in pin single and double mutant plants. However, melatonin treatment had little effect on primary root growth in the presence of high concentrations of auxin biosynthesis inhibitors, or polar transport inhibitor, and could not rescue the root length defect of the IAA biosynthesis quintuple mutant yucQ. Therefore, we propose that melatonin promotes primary root growth in an IAA-dependent manner.
A PPMAP analysis of the filamentary structures in Ophiuchus L1688 and L1689
Authors: Howard A D P , Whitworth A P , Griffin M J , Marsh K A , Smith M W L 
Published: April 2021

ABSTRACT
We use the Point Process MAPping (PPMAP) algorithm to reanalyse the Herschel and SCUBA-2 observations of the L1688 and L1689 subregions of the Ophiuchus molecular cloud. PPMAP delivers maps with high resolution (here 14 arcsec, corresponding to ${\sim}0.01\, {\rm pc}$ at ${\sim}140\, {\rm pc}$), by using the observations at their native resolutions. PPMAP also delivers more accurate dust optical depths, by distinguishing dust of different types and at different temperatures. The filaments and pre-stellar cores almost all lie in regions with $N_{\rm H_2}\gtrsim 7\times 10^{21}\, {\rm cm}^{-2}$ (corresponding to AV ≳ 7). The dust temperature, T, tends to be correlated with the dust opacity index, β, with low T and low β concentrated in the interiors of filaments. The one exception to this tendency is a section of filament in L1688 that falls – in projection – between the two B stars: S1 and HD147889; here T and β are relatively high, and there is compelling evidence that feedback from these two stars has heated and compressed the filament. Filament fwhms are typically in the range $0.10$ to $0.15\, {\rm pc}$. Most filaments have line-densities in the range $25$ to $65\, {\rm M_{\odot }\, pc^{-1}}$. If their only support is thermal gas pressure, and the gas is at the canonical temperature of $10\, {\rm K}$, the filaments are highly supercritical. However, there is some evidence from ammonia observations that the gas is significantly warmer than this, and we cannot rule out the possibility of additional support from turbulence and/or magnetic fields. On the basis of their spatial distribution, we argue that most of the starless cores are likely to disperse (rather than evolving to become pre-stellar).
The orbit and stellar masses of the archetype colliding-wind binary WR 140
Authors: Thomas Joshua D , Richardson Noel D , Eldridge J J , Schaefer Gail H , Monnier John D , Sana Hugues , Moffat Anthony F J , Williams Peredur , Corcoran Michael F , Stevens Ian R , Weigelt Gerd , Zainol Farrah D , Anugu Narsireddy , Le Bouquin Jean-Baptiste , ten Brummelaar Theo , Campos Fran , Couperus Andrew , Davies Claire L , Ennis Jacob , Eversberg Thomas , Garde Oliver , Gardner Tyler , Fló Joan Guarro , Kraus Stefan , Labdon Aaron , Lanthermann Cyprien , Leadbeater Robin , Lester T , Maki Courtney , McBride Brendan , Ozuyar Dogus , Ribeiro J , Setterholm Benjamin , Stober Berthold , Wood Mackenna , Zurmühl Uwe 
Published: April 2021

ABSTRACT
We present updated orbital elements for the Wolf–Rayet (WR) binary WR 140 (HD 193793; WC7pd + O5.5fc). The new orbital elements were derived using previously published measurements along with 160 new radial velocity measurements across the 2016 periastron passage of WR 140. Additionally, four new measurements of the orbital astrometry were collected with the CHARA Array. With these measurements, we derive stellar masses of $M_{\rm WR} = 10.31\pm 0.45 \, \mathrm{M}_\odot$ and $M_{\rm O} = 29.27\pm 1.14 \, \mathrm{M}_{\odot }$. We also include a discussion of the evolutionary history of this system from the Binary Population and Spectral Synthesis model grid to show that this WR star likely formed primarily through mass-loss in the stellar winds, with only a moderate amount of mass lost or transferred through binary interactions.
Explaining cosmological anisotropy: evidence for causal horizons from CMB data
Authors: Fosalba Pablo , Gaztañaga Enrique 
Published: April 2021

ABSTRACT
The origin of power asymmetry and other measures of statistical anisotropy on the largest scales of the universe, as manifested in cosmic microwave background (CMB) and large-scale structure data, is a long-standing open question in cosmology. In this paper, we analyse the Planck Legacy temperature anisotropy data and find strong evidence for a violation of the Cosmological principle of isotropy, with a probability of being a statistical fluctuation of the order of ∼10−9. The detected anisotropy is related to large-scale directional ΛCDM cosmological parameter variations across the CMB sky, which are sourced by three distinct patches in the maps with circularly averaged sizes between 40° and 70° in radius. We discuss the robustness of our findings to different foreground separation methods and analysis choices, and find consistent results from WMAP data when limiting the analysis to the same scales. We argue that these well-defined regions within the cosmological parameter maps may reflect finite and casually disjoint horizons across the observable universe. In particular, we show that the observed relation between horizon size and mean dark energy density within a given horizon is in good agreement with expectations from a recently proposed model of the universe that explains cosmic acceleration and cosmological parameter tensions between the high- and low-redshift universe from the existence of casual horizons within our universe.
Information content of higher order galaxy correlation functions
Authors: Samushia Lado , Slepian Zachary , Villaescusa-Navarro Francisco 
Published: April 2021

ABSTRACT
The shapes of galaxy N-point correlation functions can be used as standard rulers to constrain the distance–redshift relationship. The cosmological density fields traced by late-time galaxy formation are initially nearly Gaussian, and hence, all the cosmological information can be extracted from their two-point correlation function. Subsequent non-linear evolution under gravity, as well as halo and then galaxy formation, generates higher order correlation functions. Since the mapping of the initial to the final density field is, on large scales, invertible, it is often claimed that the information content of the initial field’s power spectrum is equal to that of all the higher order functions of the final, non-linear field. This claim implies that reconstruction of the initial density field from the non-linear field renders analysis of higher order correlation functions of the latter superfluous. We show that this claim is false when the N-point functions are used as standard rulers. Constraints available from joint analysis of the two and three-point correlation functions can, in some cases, exceed those offered by the initial power spectrum. We provide a mathematical justification for this claim and demonstrate it using a large suite of N-body simulations. In particular, we show that for the z = 0 real-space matter field in the limit of vanishing shot-noise, taking modes up to kmax = 0.2 h Mpc−1, using the bispectrum alone offers a factor of 2 reduction in the variance on the cosmic distance scale relative to that available from the linear power spectrum.
The evolution of the UV luminosity and stellar mass functions of Lyman-α emitters from z ∼ 2 to z ∼ 6
Authors: Santos S , Sobral D , Butterworth J , Paulino-Afonso A , Ribeiro B , da Cunha E , Calhau J , Khostovan A A , Matthee J , Arrabal Haro P 
Published: April 2021

ABSTRACT
We measure the evolution of the rest-frame UV luminosity function (LF) and the stellar mass function (SMF) of Lyman-α (Ly α) emitters (LAEs) from z ∼ 2 to z ∼ 6 by exploring ∼4000 LAEs from the SC4K sample. We find a correlation between Ly α luminosity (LLy α) and rest-frame UV (MUV), with best fit M$_{\rm UV}=-1.6_{-0.3}^{+0.2}\log _{10} (\rm L_{Ly\,\alpha }/erg\, s^{-1})+47_{-11}^{+12}$ and a shallower relation between LLy α and stellar mass (M⋆), with best fit $\log _{10} (\rm M_\star /{\rm M}_\odot)=0.9_{-0.1}^{+0.1}\log _{10} (\rm L_{Ly\,\alpha }/erg\, s^{-1})-28_{-3.8}^{+4.0}$. An increasing LLy α cut predominantly lowers the number density of faint MUV and low M⋆ LAEs. We estimate a proxy for the full UV LFs and SMFs of LAEs with simple assumptions of the faint end slope. For the UV LF, we find a brightening of the characteristic UV luminosity (M$_{\rm UV}^*$) with increasing redshift and a decrease of the characteristic number density (Φ*). For the SMF, we measure a characteristic stellar mass (${\rm M_\star ^*/{\rm M}_\odot }$) increase with increasing redshift, and a Φ* decline. However, if we apply a uniform luminosity cut of $\log _{10} (\rm L_{Ly\,\alpha }/erg\, s^{-1}) \ge 43.0$, we find much milder to no evolution in the UV and SMF of LAEs. The UV luminosity density (ρUV) of the full sample of LAEs shows moderate evolution and the stellar mass density (ρM) decreases, with both being always lower than the total ρUV and ρM of more typical galaxies but slowly approaching them with increasing redshift. Overall, our results indicate that both ρUV and ρM of LAEs slowly approach the measurements of continuum-selected galaxies at z &gt; 6, which suggests a key role of LAEs in the epoch of reionization.
Tangled magnetic field model of QPOs
Authors: Bretz Joseph , van Eysden C A , Link Bennett 
Published: April 2021

ABSTRACT
The highly tangled magnetic field of a magnetar supports shear waves similar to Alfvén waves in an ordered magnetic field. Here, we explore if torsional modes excited in the stellar interior and magnetosphere can explain the quasi-periodic oscillations (QPOs) observed in the tail of the giant flare of SGR 1900+14. We solve the initial value problem for a tangled magnetic field that couples interior shear waves to relativistic Alfvén shear waves in the magnetosphere. Assuming stellar oscillations arise from the sudden release of magnetic energy, we obtain constraints on the energetics and geometry of the process. If the flare energy is deposited initially inside the star, the wave energy propagates relatively slowly to the magnetosphere which is at odds with the observed rise time of the radiative event of ≲ 10 ms. Nor can the flare energy be deposited entirely outside the star, as most of the energy reflects off the stellar surface, giving surface oscillations of insufficient magnitude to produce detectable modulations of magnetospheric currents. Energy deposition in a volume that straddles the stellar surface gives agreement with the observed rise time and excites a range of modes with substantial amplitude at observed QPO frequencies. In general, localized energy deposition excites a broad range of modes that encompasses the observed QPOs, though many more modes are excited than the number of observed QPOs. If the flare energy is deposited axisymmetrically, as is possible for a certain class of MHD instabilities, the number of modes that is excited is considerably reduced.
Dengue virus 2 capsid protein chaperones the strand displacement of 5′-3′ cyclization sequences
Authors: Yong Xin Ee , Palur V Raghuvamsi , Anand Ganesh S , Wohland Thorsten , Sharma Kamal K 
Published: April 2021

AbstractBy virtue of its chaperone activity, the capsid protein of dengue virus strain 2 (DENV2C) promotes nucleic acid structural rearrangements. However, the role of DENV2C during the interaction of RNA elements involved in stabilizing the 5′-3′ panhandle structure of DENV RNA is still unclear. Therefore, we determined how DENV2C affects structural functionality of the capsid-coding region hairpin element (cHP) during annealing and strand displacement of the 9-nt cyclization sequence (5CS) and its complementary 3CS. cHP has two distinct functions: a role in translation start codon selection and a role in RNA synthesis. Our results showed that cHP impedes annealing between 5CS and 3CS. Although DENV2C does not modulate structural functionality of cHP, it accelerates annealing and specifically promotes strand displacement of 3CS during 5′-3′ panhandle formation. Furthermore, DENV2C exerts its chaperone activity by favouring one of the active conformations of cHP. Based on our results, we propose mechanisms for annealing and strand displacement involving cHP. Thus, our results provide mechanistic insights into how DENV2C regulates RNA synthesis by modulating essential RNA elements in the capsid-coding region, that in turn allow for DENV replication.