bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evolution of disc thickness in simulated high-redshift galaxies
Authors: Meng Xi , Gnedin Oleg Y 
Published: January 2021

ABSTRACT
We study the growth of stellar discs of Milky Way-sized galaxies using a suite of cosmological simulations. We calculate the half-mass axis lengths and axis ratios of stellar populations split by age in galaxies with stellar mass $M_{*}=10^7\!-\!10^{10}\, \mathrm{M}_{\odot }$ at redshifts z &gt; 1.5. We find that in our simulations stars always form in relatively thin discs, and at ages below 100 Myr are contained within half-mass height z1/2 ∼ 0.1 kpc and short-to-long axial ratio z1/2/x1/2 ∼ 0.15. Disc thickness increases with the age of stellar population, reaching median z1/2 ∼ 0.8 kpc and z1/2/x1/2 ∼ 0.6 for stars older than 500 Myr. We trace the same group of stars over the simulation snapshots and show explicitly that their intrinsic shape grows more spheroidal over time. We identify a new mechanism that contributes to the observed disc thickness: rapid changes in the orientation of the galactic plane mix the configuration of young stars. The frequently mentioned ‘upside-down’ formation scenario of galactic discs, which posits that young stars form in already thick discs at high redshift, may be missing this additional mechanism of quick disc inflation. The actual formation of stars within a fairly thin plane is consistent with the correspondingly flat configuration of dense molecular gas that fuels star formation.
Optical and near-infrared observations of the SPT2349-56 proto-cluster core at z = 4.3
Authors: Rotermund K M , Chapman S C , Phadke K A , Hill R , Pass E , Aravena M , Ashby M L N , Babul A , Béthermin M , Canning R , de Breuck C , Dong C , Gonzalez A H , Hayward C C , Jarugula S , Marrone D P , Narayanan D , Reuter C , Scott D , Spilker J S , Vieira J D , Wang G , Weiss A 
Published: January 2021

ABSTRACT
We present Gemini-S and Spitzer-IRAC optical-through-near-IR observations in the field of the SPT2349-56 proto-cluster at z = 4.3. We detect optical/IR counterparts for only 9 of the 14 submillimetre galaxies (SMGs) previously identified by ALMA in the core of SPT2349-56. In addition, we detect four z ∼ 4 Lyman-break galaxies (LBGs) in the 30 arcsec-diameter region surrounding this proto-cluster core. Three of the four LBGs are new systems, while one appears to be a counterpart of one of the nine observed SMGs. We identify a candidate brightest cluster galaxy (BCG) with a stellar mass of $(3.2^{+2.3}_{-1.4})\times 10^{11}$ M⊙. The stellar masses of the eight other SMGs place them on, above, and below the main sequence of star formation at z ≈ 4.5. The cumulative stellar mass for the SPT2349-56 core is at least (12.2 ± 2.8) × 1011 M⊙, a sizeable fraction of the stellar mass in local BCGs, and close to the universal baryon fraction (0.19) relative to the virial mass of the core (1013 M⊙). As all 14 of these SMGs are destined to quickly merge, we conclude that the proto-cluster core has already developed a significant stellar mass at this early stage, comparable to z = 1 BCGs. Importantly, we also find that the SPT2349-56 core structure would be difficult to uncover in optical surveys, with none of the ALMA sources being easily identifiable or constrained through g, r, and i colour selection in deep optical surveys and only a modest overdensity of LBGs over the more extended structure. SPT2349-56 therefore represents a truly dust-obscured phase of a massive cluster core under formation.
The T414G mitochondrial DNA mutation: a biomarker of ageing in human eye
Authors: Gary Anne-Sophie , Dorr Marie M , Rochette Patrick J 
Published: January 2021

Abstract
The mitochondrial mutation T414G (mtDNAT414G) has been shown to accumulate in aged and sun-exposed skin. The human eye is also exposed to solar harmful rays. More precisely, the anterior structures of the eye (cornea, iris) filter UV rays and the posterior portion of the eye (retina) is exposed to visible light. These rays can catalyse mutations in mitochondrial DNA such as the mtDNAT414G, but the latter has never been investigated in the human ocular structures. In this study, we have developed a technique to precisely assess the occurrence of mtDNAT414G. Using this technique, we have quantified mtDNAT414G in different human ocular structures. We found an age-dependent accumulation of mtDNAT414G in the corneal stroma, the cellular layer conferring transparency and rigidity to the human cornea, and in the iris. Since cornea and iris are two anterior ocular structures exposed to solar UV rays, this suggests that the mtDNAT414G mutation is resulting from cumulative solar exposure and this could make the mtDNAT414G a good marker of solar exposure. We have previously shown that the mtDNACD4977 and mtDNA3895 deletions accumulate over time in photo-exposed ocular structures. With the addition of mtDNAT414G mutation, it becomes feasible to combine the levels of these different mtDNA mutations to obtain an accurate assessment of the solar exposure that an individual has accumulated during his/her lifetime.
Genetic damage in lymphocytes of lung cancer patients is correlated to the composition of the respiratory tract microbiome
Authors: Druzhinin V G , Matskova L V , Demenkov P S , Baranova E D , Volobaev V P , Minina V I , Larionov A V , Titov V A , Fucic A 
Published: January 2021

AbstractRecent findings indicate that the microbiome may have significant impact on the development of lung cancer by its effects on inflammation, dysbiosis or genome damage. The aim of this study was to compare the sputum microbiome of lung cancer (LC) patients with the chromosomal aberration (CA) and micronuclei (MN) frequency in peripheral blood lymphocytes. In the study, the taxonomic composition of the sputum microbiome of 66 men with untreated LC were compared with 62 control subjects with respect to CA and MN frequency and centromere fluorescence in situ hybridisation analysis. Results showed a significant increase in CA (4.11 ± 2.48% versus 2.08 ± 1.18%) and MN (1.53 ± 0.67% versus 0.87 ± 0.49%) frequencies, respectively, in LC patients as compared to control subjects. The higher frequency of centromeric positive MN of LC patients was mainly due to aneuploidy. A significant increase in Streptococcus, Bacillus, Gemella and Haemophilus in LC patients was detected, in comparison to the control subjects while 18 bacterial genera were significantly reduced, which indicates a decrease in the beta diversity in the microbiome of LC patients. Although, the CA frequency in LC patients is significantly associated with an increased presence of the genera Bacteroides, Lachnoanaerobaculum, Porphyromonas, Mycoplasma and Fusobacterium in their sputum, and a decrease for the genus Granulicatella after application of false discovery rate correction, significance was not any more present. The decrease of MN frequency of LC patients is significantly associated with an increase in Megasphaera genera and Selenomonas bovis. In conclusion, a significant difference in beta diversity of microbiome between LC and control subjects and association between the sputum microbiome composition and genome damage of LC patients was detected, thus supporting previous studies suggesting an etiological connection between the airway microbiome and LC.
The solution structures of higher-order human telomere G-quadruplex multimers
Authors: Monsen Robert C , Chakravarthy Srinivas , Dean William L , Chaires Jonathan B , Trent John O 
Published: January 2021

AbstractHuman telomeres contain the repeat DNA sequence 5′-d(TTAGGG), with duplex regions that are several kilobases long terminating in a 3′ single-stranded overhang. The structure of the single-stranded overhang is not known with certainty, with disparate models proposed in the literature. We report here the results of an integrated structural biology approach that combines small-angle X-ray scattering, circular dichroism (CD), analytical ultracentrifugation, size-exclusion column chromatography and molecular dynamics simulations that provide the most detailed characterization to date of the structure of the telomeric overhang. We find that the single-stranded sequences 5′-d(TTAGGG)n, with n = 8, 12 and 16, fold into multimeric structures containing the maximal number (2, 3 and 4, respectively) of contiguous G4 units with no long gaps between units. The G4 units are a mixture of hybrid-1 and hybrid-2 conformers. In the multimeric structures, G4 units interact, at least transiently, at the interfaces between units to produce distinctive CD signatures. Global fitting of our hydrodynamic and scattering data to a worm-like chain (WLC) model indicates that these multimeric G4 structures are semi-flexible, with a persistence length of ∼34 Å. Investigations of its flexibility using MD simulations reveal stacking, unstacking, and coiling movements, which yield unique sites for drug targeting.
Lamin B1 acetylation slows the G1 to S cell cycle transition through inhibition of DNA repair
Authors: Murray-Nerger Laura A , Justice Joshua L , Rekapalli Pranav , Hutton Josiah E , Cristea Ileana M 
Published: January 2021

Abstract
The integrity and regulation of the nuclear lamina is essential for nuclear organization and chromatin stability, with its dysregulation being linked to laminopathy diseases and cancer. Although numerous posttranslational modifications have been identified on lamins, few have been ascribed a regulatory function. Here, we establish that lamin B1 (LMNB1) acetylation at K134 is a molecular toggle that controls nuclear periphery stability, cell cycle progression, and DNA repair. LMNB1 acetylation prevents lamina disruption during herpesvirus type 1 (HSV-1) infection, thereby inhibiting virus production. We also demonstrate the broad impact of this site on laminar processes in uninfected cells. LMNB1 acetylation negatively regulates canonical nonhomologous end joining by impairing the recruitment of 53BP1 to damaged DNA. This defect causes a delay in DNA damage resolution and a persistent activation of the G1/S checkpoint. Altogether, we reveal LMNB1 acetylation as a mechanism for controlling DNA repair pathway choice and stabilizing the nuclear periphery.
Spetzler-Martin Grade III Arteriovenous Malformations: A Comparison of Modified and Supplemented Spetzler-Martin Grading Systems
Authors: Frisoli Fabio A , Catapano Joshua S , Farhadi Dara S , Cadigan Megan S , Nguyen Candice L , Labib Mohamed A , Srinivasan Visish M , Lawton Michael T 
Published: January 2021

Abstract

BACKGROUND
The modified Spetzler-Martin (SM) grading system proposes that grade III arteriovenous malformation (AVM) subtypes are associated with variable microsurgical risks, with small AVMs (III−) having lower risk and medium/eloquent AVMs (III+) having higher risk. Adding patient age and AVM bleeding status and compactness to the SM grade produces a score – the supplemented SM (Supp-SM) grade – to more accurately assess preoperative risk.

OBJECTIVE
To compare the predictive power of the modified SM and Supp-SM grades for risk assessment in patients with grade III AVMs.

METHODS
Patients with SM grade III AVMs treated between 2011 and 2018 were retrospectively reviewed. Good outcomes were defined as modified Rankin Scale (mRS) scores ≤ 2 or unchanged/improved mRS scores (pre- vs postsurgery).

RESULTS
Of 102 patients with SM grade III AVMs, 59% had grade III− and 24% had grade III+ AVMs. Supp SM grade 6 and grade 7 AVMs accounted for 44% and 24%, respectively. Overall, 33% of patients worsened but outcomes did not significantly differ by SM III subtype. Neurological outcomes were associated with Supp-SM grade, with proportions of patients with worsening increasing from 0% with Supp-SM grade 4 AVMs to 54% with Supp-SM grade 7 AVMs. Analyses of factors associated with neurological worsening identified age > 60 yr and Supp-SM grade 7 as significant.

CONCLUSION
Supp-SM grades were more predictive of microsurgical outcomes than modified SM grades for grade III AVMs, with a hard cutoff for acceptable surgical risk at Supp-SM grade 6. Supp-SM grading is a better decision-making tool than subtyping with the modified SM scale.
A Citrus Phosphate Starvation Response Factor CsPHL3 Negatively Regulates Carotenoid Metabolism
Authors: Lu Suwen , Ye Junli , Zhu Kaijie , Zhang Yin , Zhang Mengwei , Xu Qiang , Deng Xiuxin 
Published: January 2021

Abstract
Carotenoids provide precursors for the biosynthesis of strigolactones, which are a new class of hormones that are essential in phosphate (Pi) signaling during plant development. Carotenoid metabolism is a finely tuned pathway, but our understanding of the regulation mechanisms is still limited. In this study, we isolated a protein designated as CsPHL3 from citrus. CsPHL3 belonged to the Pi starvation response factor (PHR)-like subclade and was upregulated by low Pi. Acting as a nucleus-localized protein with transactivation activity, CsPHL3 bound directly to activate the promoter of a key metabolic gene, lycopene β-cyclase1 (LCYb1). Transgenic analysis revealed that the CsPHL3-overexpressing tomato plants exhibited abnormal growth, like the plants grew under limited Pi conditions. The transgenic lines showed reduced carotenoid contents and elevated expression of LCYb genes but downregulation of other key carotenogenic genes, including phytoene synthase (PSY). Moreover, CsPHL3 induced anthocyanin biosynthesis and affected Pi signaling in the transgenic plants. We further demonstrated that the expression of PSY was negatively regulated by CsPHL3 and high Pi. It is concluded that CsPHL3 is a Pi starvation response factor that negatively regulates carotenoid metabolism by modulating the expression of carotenogenic genes. Establishment of the CsPHL3-CsLCYb1 network provides new valuable knowledge of the function and underlying mechanism of PHR transcription factors and expands our understanding of the complex regulation mechanisms of carotenoid biosynthesis.
Posttranslational Modifications: Regulation of Nitrogen Utilization and Signaling
Authors: Wang Wei , Li Aifu , Zhang Zhihua , Chu Chengcai 
Published: January 2021

Abstract
Nitrogen is the most important macroelement required for the composition of key molecules, such as nucleic acids, proteins and other organic compounds. As sessile organisms, plants have evolved sophisticated mechanisms to acquire nitrogen for their normal growth and development. Besides the transcriptional and translational regulation of nitrogen uptake, assimilation, remobilization and signal transduction, posttranslational modifications (PTMs) are shown to participate in these processes in plants. In addition to alterations in protein abundance, PTMs may dramatically increase the complexity of the proteome without the concomitant changes in gene transcription and have emerged as an important type of protein regulation in terms of protein function, subcellular localization and protein activity and stability. Herein, we briefly summarize recent advances on the posttranslational regulation of nitrogen uptake, assimilation, remobilization and nitrogen signaling and discuss the underlying mechanisms of PTMs as well as the signal output of such PTMs. Understanding these regulation mechanisms will provide novel insights for improving the nitrogen use efficiency of plants.
Structural insights into the multivalent binding of the Arabidopsis FLOWERING LOCUS T promoter by the CO–NF–Y master transcription factor complex
Authors: Lv Xinchen , Zeng Xiaolin , Hu Hongmiao , Chen Lixian , Zhang Fan , Liu Rui , Liu Yue , Zhou Xuelin , Wang Changshi , Wu Zhe , Kim Chanhong , He Yuehui , Du Jiamu 
Published: January 2021

Abstract
Flowering plants sense various environmental and endogenous signals to trigger the floral transition and start the reproductive growth cycle. CONSTANS (CO) is a master transcription factor in the photoperiod floral pathway that integrates upstream signals and activates the florigen gene FLOWERING LOCUS T (FT). Here, we performed comprehensive structural and biochemical analyses to study the molecular mechanism underlying the regulation of FT by CO in Arabidopsis thaliana. We show that the four previously characterized cis-elements in the FT promoter proximal region, CORE1, CORE2, P1, and P2, are all direct CO binding sites. Structural analysis of CO in complex with NUCLEAR FACTOR-YB/YC (NF–YB/YC) and the CORE2 or CORE1 elements revealed the molecular basis for the specific recognition of the shared TGTG motifs. Biochemical analysis suggested that CO might form a homomultimeric assembly via its N-terminal B-Box domain and simultaneously occupy multiple cis-elements within the FT promoter. We suggest that this multivalent binding gives the CO–NF–Y complex high affinity and specificity for FT promoter binding. Overall, our data provide a detailed molecular model for the regulation of FT by the master transcription factor complex CO–NF–Y during the floral transition.
Changes in dietary fat intake and associations with mental health in a UK public sample during the COVID-19 pandemic
Authors: Wilson Jason J , McMullan Ilona , Blackburn Nicole E , Klempel Natalie , Yakkundi Anita , Armstrong Nicola C , Brolly Colette , Butler Laurie T , Barnett Yvonne , Jacob Louis , Koyanagi Ai , Smith Lee , Tully Mark A 
Published: January 2021

ABSTRACTBackgroundConsumption of unhealthy foods may have changed during the COVID-19 pandemic. This study explored how dietary fat intake was impacted in a sample of the UK public who were social distancing during the COVID-19 pandemic.MethodsData were collected from a UK COVID-19 online survey. Fat intake was measured using the Dietary Instrument for Nutrition Education questionnaire. Anxiety and depressive symptoms were assessed using Becks’ Anxiety and Depression Inventories, while the short-form Warwick-Edinburgh Mental Well-being Scale assessed mental well-being. Differences between individuals who increased versus decreased fat intake were explored using chi-square or independent sample t-tests. Association between fat intake and mental health was explored using adjusted linear regression models.ResultsEight hundred and eighty-seven adults were included. Approximately, 34% recorded medium-to-high levels of fat consumption during social distancing. Around 48% reported decreased fat intake during social distancing compared to usual levels, while 41.3% documented increased fat intake. Fat intake was not significantly associated (P &gt; 0.05) with any measures of mental health.ConclusionsA higher proportion of a sample of UK adults social distancing during the COVID-19 pandemic recorded decreased fat intake when compared to levels prior to social distancing. There appeared to be no associations between fat intake and mental health.
When a Master Dies: Speculation and Asset Float
Authors: Pénasse Julien , Renneboog Luc , Scheinkman José A 
Published: January 2021

Abstract
An artist’s death constitutes a negative shock to his future production; death permanently decreases the artist’s float. We use this shock to test predictions of speculative trading models with short-selling constraints. As predicted in our model, we find that an artist’s premature death leads to a permanent increase in prices and turnover; this effect being larger for more famous artists. We document that premature death increases prices (by 54.7%) and secondary market volume (by 63.2%).
JAK1: Number one in the family; number one in inflammation?
Authors: Spinelli Francesca Romana , Colbert Robert A , Gadina Massimo 
Published: January 2021

AbstractSeveral cytokines involved in inflammatory pathologies signal via the Janus kinase-signal transducer and activator of transcription pathway. Four JAKs are known: JAK1, JAK2, JAK3 and TYK2. The specific activation of JAKs and STATs determines the biological effects of each cytokine. JAK1 is involved in the signalling of ‘γc’ receptor cytokines (IL-2, IL-4, IL-7, IL-9, IL-15 and IL-21), pro-inflammatory cytokines including IL-6, as well as IFN. The critical position of JAK1 downstream of these cytokines suggests that JAK1-selective inhibitors are comparable to non-selective ones, without the unwanted consequences of JAK2- or JAK3-blockade. JAK inhibition has led to a better understanding of the biology of synovial inflammation and bone homeostasis. Moreover, the efficacy of non-selective JAK inhibitors and novel JAK1-selective drugs in RA supports a role for JAK1 in its pathogenesis. JAK1-selective drugs are also showing promise in axial spondyloarthritis, suggesting that they may target additional regulatory pathways that impact cytokines such as TNF and IL-17A, which do not use JAKs. Additionally, evidence now supports a JAK1 predominance in the signalling of IL-6 and oncostatin M, and indirectly, of TNF in synovial fibroblasts, macrophages and endothelial cells. Notably, bone homeostasis is also dependent on cytokines relying on JAK1 signalling to promote receptor activator of NF-κB ligand expression in osteoblasts and T cells, contributing to osteoclastogenesis. Here, the contribution of JAK1 over other kinases is unclear. While beneficial effects of JAK inhibitors on bone erosion are supported by preclinical and clinical data, effects on new bone formation in axial spondyloarthritis requires additional study.
Lifting the Veil on Campus Sexual Assault: Morehouse College, Hegemonic Masculinity, and Revealing Racialized Rape Culture through the Du Boisian Lens
Authors: Grundy Saida 
Published: January 2021

AbstractAs national rates of sexual assault continue to fall, sexual assault rates for colleges and universities remain stagnant. Researchers ask why rates of sexual assault on college campuses differ from rates across the nation. One approach examines the contexts in which college men “do” rape culture. How men are racialized, however, is a critically missing context in understanding the cultures in which gender violence persists. Although race is one of the most pronounced ways that college men see themselves and their interactions, it is overlooked in extant literature. In failing to apply race theories to college men, researchers have missed an opportunity to unveil how their rape cultures operate as racialized rape cultures. Interviews with 32 graduates of Morehouse College, the nation’s only historically Black college for men, reveal that race is a modality through which men make meanings of masculinity, sex, women, competition, and the repercussions of sexual assault in ways that preserve gender violence on campus. Through a Du Boisian lens of double consciousness, this study finds that rape culture is not only how these men do gender, but is also a formative means by which they do race and are racialized throughout their college experience.