bluuebunny/crossref_metadata_2025_split huggingface dataset:
Are subspecies (ofEira barbara) real?
Authors: Schiaffini Mauro Ignacio 
Published: July 2020

AbstractThe subspecies concept is one of the most controversial in Linnean taxonomy. In the past, subspecies were described without a clear conceptual framework, triggering confusion and motivating criticism of the very concept of a subspecies. At present, subspecies are conceived as aggregates of populations that are geographically isolated, are composed of interfertile individuals, and are morphologically diagnosable. The tayra, Eira barbara, was described in 1758 and has had a stable taxonomic history at the species level. However, below the species level, 16 subspecies have been named, with from two to seven subspecies recognized as valid by different authors. None of the subspecies were, however, described within a clear conceptual framework. Using the modern concept of a subspecies, I analyzed subspecies of E. barbara recognized by recent authors. I gathered morphometric data from 155 specimens in mammal collections, georeferenced each specimen, and recorded membership to subspecies assigned by different references and by its location. I gathered climate and geographic data for each location. I analyzed data using Principal Components Analysis (PCA) and analysis of variance (ANOVA). Specimens exhibited sexual dimorphism in size but not in skull shape. I used regression analysis to test for associations between skull shape and size and climate data. Geographic analyses documented that subspecies are not allopatric, violating one of the main properties of the subspecies concept. ANOVA showed significant differences in skull morphology between some pairs of recognized subspecies but not others. However, none of the subspecies segregated in the PCA. Thus, the recognized subspecies could not be diagnosed from morphological data, violating another property of the subspecies concept. Size varied greatly between the sexes using different schemes for recognized subspecies. Climate variables explained between 4% and 6% of size variation for males and females. Skull shape proved not to be geographically variable.
Effect of Aspirin on Cancer Incidence and Mortality in Older Adults
Authors: McNeil John J , Gibbs , *Peter , Orchard Suzanne G , Lockery Jessica E , Bernstein Wendy B , Cao Yin , Ford Leslie , Haydon Andrew , Kirpach Brenda , Macrae Finlay , McLean Catriona , Millar Jeremy , Murray Anne M , Nelson Mark R , Polekhina Galina , Reid Christopher M , Richmond Ellen , Rodríguez Luz Maria , Shah Raj C , Tie Jeanne , Umar Asad , Londen G J van , Ronaldson Kathlyn , Wolfe Rory , Woods Robyn L , Zalcberg John , Chan Andrew T ,   the ASPREE Investigator Group
Published: July 2020

Abstract

Background
ASPirin in Reducing Events in the Elderly, a randomized, double-blind, placebo-controlled trial of daily low-dose aspirin (100 mg) in older adults, showed an increase in all-cause mortality, primarily due to cancer. In contrast, prior randomized controlled trials, mainly involving younger individuals, demonstrated a delayed cancer benefit with aspirin. We now report a detailed analysis of cancer incidence and mortality.

Methods
19 114 Australian and US community-dwelling participants aged 70 years and older (US minorities 65 years and older) without cardiovascular disease, dementia, or physical disability were randomly assigned and followed for a median of 4.7 years. Fatal and nonfatal cancer events, a prespecified secondary endpoint, were adjudicated based on clinical records.

Results
981 cancer events occurred in the aspirin and 952 in the placebo groups. There was no statistically significant difference between groups for all incident cancers (hazard ratio [HR] = 1.04, 95% confidence interval [CI] = 0.95 to 1.14), hematological cancer (HR = 0.98, 95% CI = 0.73 to 1.30), or all solid cancers (HR = 1.05, 95% CI = 0.95 to 1.15), including by specific tumor type. However, aspirin was associated with an increased risk of incident cancer that had metastasized (HR = 1.19, 95% CI = 1.00 to 1.43) or was stage 4 at diagnosis (HR = 1.22, 95% CI = 1.02 to 1.45), and with higher risk of death for cancers that presented at stages 3 (HR = 2.11, 95% CI = 1.03 to 4.33) or 4 (HR = 1.31, 95% CI = 1.04 to 1.64).

Conclusions
In older adults, aspirin treatment had an adverse effect on later stages of cancer evolution. These findings suggest that in older persons, aspirin may accelerate the progression of cancer and, thus, suggest caution with its use in this age group.
Clinical Implications of Body Mass Index in Metastatic Breast Cancer Patients Treated With Abemaciclib and Endocrine Therapy
Authors: Franzoi Maria Alice , Eiger Daniel , Ameye Lieveke , Ponde Noam , Caparica Rafael , De Angelis Claudia , Brandão Mariana , Desmedt Christine , Di Cosimo Serena , Kotecki Nuria , Lambertini Matteo , Awada Ahmad , Piccart Martine , Azambuja Evandro de 
Published: July 2020

Abstract

Background
There are limited data regarding the impact of body mass index (BMI) on outcomes in advanced breast cancer, especially in patients treated with endocrine therapy (ET) + cyclin-dependent kinase 4/6 inhibitors.

Methods
A pooled analysis of individual patient-level data from MONARCH 2 and 3 trials was performed. Patients were classified according to baseline BMI into underweight (&lt;18.5 kg/m2), normal (18.5-24.9 kg/m2), overweight (25-29.9 kg/m2), and obese (≥30 kg/m2) and divided into 2 treatment groups: abemaciclib + ET vs placebo + ET. The primary endpoint was progression-free survival (PFS) according to BMI in each treatment group. Secondary endpoints were response rate, adverse events according to BMI, and loss of weight (≥5% from baseline) during treatment.

Results
This analysis included 1138 patients (757 received abemaciclib + ET and 381 placebo + ET). There was no difference in PFS between BMI categories in either group, although normal-weight patients presented a numerically higher benefit with abemaciclib + ET (Pinteraction = .07). Normal and/or underweight patients presented higher overall response rate in the abemaciclib + ET group compared with overweight and/or obese patients (49.4% vs 41.6%, odds ratio = 0.73, 95% confidence interval = 0.54 to 0.99) as well as higher neutropenia frequency (51.0% vs 40.4%, P = .004). Weight loss was more frequent in the abemaciclib + ET group (odds ratio = 3.23, 95% confidence interval = 2.09 to 5.01).

Conclusions
Adding abemaciclib to ET prolongs PFS regardless of BMI, showing that overweight or obese patients also benefit from this regimen. Our results elicit the possibility of a better effect of abemaciclib in normal and/or underweight patients compared with overweight and/or obese patients. More studies analyzing body composition parameters in patients under treatment with cyclin-dependent kinase 4/6 inhibitors may further clarify this hypothesis.
Dedifferentiated liposarcoma of the scrotum. Case report and literature review
Authors: Salas-Parra Ruben D , Tavares Larissa L , Gupta Ranjan , Silletti Joseph , Shah Ajay 
Published: July 2020

Abstract
Malignant paratesticular and spermatic cord tumors are rare and often misdiagnosed preoperatively due to clinical presentations similar to other benign scrotal mass etiologies. Only a few cases regarding giant, paratesticular liposarcomas (&gt;10 cm) have been reported. We report a unique case of an aggressive giant dedifferentiated liposarcoma of the scrotum with osteosarcoma features in a 70-year-old patient who initially presented with indolent scrotal swelling. A CT scan showed a large, complex, solid and cystic mass (12.0 x 15.5 x 19.0 cm) in the right scrotum. With a concern of a complex hydrocele, the patient was taken to the operating room for a scrotal approach to excise the hydrocele, but the spermatic cord was not traced to any discernible testicle as the entire mass was indurated and multilocular, and was excised. Pathology revealed a dedifferentiated liposarcoma, with MDM2 amplification. The patient’s course was complicated due to metastatic disease.
DNA replication and chromosome positioning throughout the interphase in three-dimensional space of plant nuclei
Authors: Němečková Alžběta , Koláčková Veronika , Vrána Jan , Doležel Jaroslav , Hřibová Eva 
Published: July 2020

AbstractDespite much recent progress, our understanding of the principles of plant genome organization and its dynamics in three-dimensional space of interphase nuclei remains surprisingly limited. Notably, it is not clear how these processes could be affected by the size of a plant’s nuclear genome. In this study, DNA replication timing and interphase chromosome positioning were analyzed in seven Poaceae species that differ in their genome size. To provide a comprehensive picture, a suite of advanced, complementary methods was used: labeling of newly replicated DNA by ethynyl-2'-deoxyuridine, isolation of nuclei at particular cell cycle phases by flow cytometric sorting, three-dimensional immunofluorescence in situ hybridization, and confocal microscopy. Our results revealed conserved dynamics of DNA replication in all species, and a similar replication timing order for telomeres and centromeres, as well as for euchromatin and heterochromatin regions, irrespective of genome size. Moreover, stable chromosome positioning was observed while transitioning through different stages of interphase. These findings expand upon earlier studies in suggesting that a more complex interplay exists between genome size, organization of repetitive DNA sequences along chromosomes, and higher order chromatin structure and its maintenance in interphase, albeit controlled by currently unknown factors.
Eclipse timing variation of GK Vir: evidence of a possible Jupiter-like planet in a circumbinary orbit
Authors: Almeida L A , Pereira E S , Borges G M , Damineli A , Michtchenko T A , Viswanathan G M 
Published: July 2020

ABSTRACT
Eclipse timing variation analysis has become a powerful method to discover planets around binary systems. We applied this technique to investigate the eclipse times of GK Vir. This system is a post-common envelope binary with an orbital period of 8.26 h. Here, we present 10 new eclipse times obtained between 2013 and 2020. We calculated the O−C diagram using a linear ephemeris and verified a clear orbital period variation (OPV) with a cyclic behaviour. We investigated if this variation could be explained by the Applegate mechanism, the apsidal motion, or the light travel time (LTT) effect. We found that the Applegate mechanism would hardly explain the OPV with its current theoretical description. We obtained using different approaches that the apsidal motion is a less likely explanation than the LTT effect. We showed that the LTT effect with one circumbinary body is the most likely cause for the OPV, which was reinforced by the orbital stability of the third body. The LTT best solution provided an orbital period of ∼24 yr for the outer body. Under the assumption of coplanarity between the external body and the inner binary, we obtained a Jupiter-like planet around the GK Vir. In this scenario, the planet has one of the longest orbital periods, with a full observational baseline, discovered so far. However, as the observational baseline of GK Vir is smaller than twice the period found in the O−C diagram, the LTT solution must be taken as preliminary.
Relativistic AGN jets – III. Synthesis of synchrotron emission from double-double radio galaxies
Authors: Walg S , Achterberg A , Markoff S , Keppens R , Porth O 
Published: July 2020

ABSTRACTThe class of double-double radio galaxies (DDRGs) relates to episodic jet outbursts. How various regions and components add to the total intensity in radio images is less well known. In this paper, we synthesize synchrotron images for DDRGs based on special relativistic hydrodynamic simulations, making advanced approximations for the magnetic fields. We study the synchrotron images for three different radial jet profiles; ordered, entangled, or mixed magnetic fields; spectral ageing from synchrotron cooling; the contribution from different jet components; the viewing angle and Doppler (de-)boosting; and the various epochs of the evolution of the DDRG. To link our results to observational data, we adopt to J1835+6204 as a reference source. In all cases, the synthesized synchrotron images show two clear pairs of hotspots, in the inner and outer lobes. The best resemblance is obtained for the piecewise isochoric jet model, for a viewing angle of approximately ϑ ∼ −71°, i.e. inclined with the lower jet towards the observer, with predominantly entangled (≳70 per cent of the magnetic pressure) in turbulent, rather than ordered fields. The effects of spectral ageing become significant when the ratio of observation frequencies and cut-off frequency νobs/ν∞, 0 ≳ 10−3, corresponding to ∼3 × 102 MHz. For viewing angles ϑ ≲ |−30°|, a DDRG morphology can no longer be recognized. The second jets must be injected within ≲ 4 per cent of the lifetime of the first jets for a DDRG structure to emerge, which is relevant for active galactic nuclei feedback constraints.
High molecular gas content and star formation rates in local galaxies that host quasars, outflows, and jets
Authors: Jarvis M E , Harrison C M , Mainieri V , Calistro Rivera G , Jethwa P , Zhang Z-Y , Alexander D M , Circosta C , Costa T , De Breuck C , Kakkad D , Kharb P , Lansbury G B , Thomson A P 
Published: July 2020

ABSTRACT
We use a sample of powerful $z\, \approx \, 0.1$ type 2 quasars (‘obscured’; log [LAGN/erg s$^{-1}]\, \gtrsim \, 45$), which host kpc-scale ionized outflows and jets, to identify possible signatures of AGN feedback on the total molecular gas reservoirs of their host galaxies. Specifically, we present Atacama Pathfinder EXperiment (APEX) observations of the CO(2–1) transition for nine sources and the CO(6–5) for a subset of three. We find that the majority of our sample reside in starburst galaxies (average specific star formation rates – sSFR – of 1.7 Gyr−1), with the seven CO-detected quasars also having large molecular gas reservoirs (average Mgas = 1.3 × 1010 M⊙), even though we had no pre-selection on the star formation or molecular gas properties. Despite the presence of quasars and outflows, we find that the molecular gas fractions (Mgas/M⋆ = 0.1–1.2) and depletion times (Mgas/SFR = 0.16–0.95 Gyr) are consistent with those expected for the overall galaxy population with matched stellar masses and sSFRs. Furthermore, for at least two of the three targets with the required measurements, the CO(6–5)/CO(2–1) emission-line ratios are consistent with star formation dominating the CO excitation over this range of transitions. The targets in our study represent a gas-rich phase of galaxy evolution with simultaneously high levels of star formation and nuclear activity; furthermore, the jets and outflows do not have an immediate appreciable impact on the global molecular gas reservoirs.
Very high redshift quasars and the rapid emergence of super-massive black holes
Authors: Kroupa Pavel , Subr Ladislav , Jerabkova Tereza , Wang Long 
Published: July 2020

Abstract
The observation of quasars at very high redshift such as Pōniuā’ena is a challenge for models of super-massive black hole (SMBH) formation. This work presents a study of SMBH formation via known physical processes in star-burst clusters formed at the onset of the formation of their hosting galaxy. While at the early stages hyper-massive star-burst clusters reach the luminosities of quasars, once their massive stars die, the ensuing gas accretion from the still forming host galaxy compresses its stellar black hole (BH) component to a compact state overcoming heating from the BH–BH binaries such that the cluster collapses, forming a massive SMBH-seed within about a hundred Myr. Within this scenario the SMBH–spheroid correlation emerges near-to-exactly. The highest-redshift quasars may thus be hyper-massive star-burst clusters or young ultra-compact dwarf galaxies (UCDs), being the precursors of the SMBHs that form therein within about 200 Myr of the first stars. For spheroid masses ≲ 109.6 M⊙ a SMBH cannot form and instead only the accumulated nuclear cluster remains. The number evolution of the quasar phases with redshift is calculated and the possible problem of missing quasars at very high redshift is raised. SMBH-bearing UCDs and the formation of spheroids are discussed critically in view of the high redshift observations. A possible tension is found between the high star-formation rates (SFRs) implied by downsizing and the observed SFRs, which may be alleviated within the IGIMF theory and if the downsizing times are somewhat longer.
Heavy elements nucleosynthesis on accreting white dwarfs: building seeds for the p-process
Authors: Battino U , Pignatari M , Travaglio C , Lederer-Woods C , Denissenkov P , Herwig F , Thielemann F , Rauscher T 
Published: July 2020

ABSTRACT
The origin of the proton-rich trans-iron isotopes in the Solar system is still uncertain. Single-degenerate thermonuclear supernovae (SNIa) with n-capture nucleosynthesis seeds assembled in the external layers of the progenitor’s rapidly accreting white dwarf (RAWD) phase may produce these isotopes. We calculate the stellar structure of the accretion phase of five white dwarf (WD) models with initial masses ≥ 0.85 $\, \mathrm{M}_\odot$ using the stellar code mesa The near-surface layers of the 1, 1.26, 1.32 and 1.38 $\, \mathrm{M}_\odot$ models are most representative of the regions in which the bulk of the p nuclei are produced during SNIa explosions, and for these models we also calculate the neutron-capture nucleosynthesis in the external layers. Contrary to previous RAWD models at lower mass, we find that the H-shell flashes are the main site of n-capture nucleosynthesis. We find high neutron densities up to several 1015 cm−3 in the most massive WDs. Through the recurrence of the H-shell flashes these intermediate neutron densities can be sustained effectively for a long time leading to high-neutron exposures with a strong production up to Pb. Both the neutron density and the neutron exposure increase with increasing the mass of the accreting WD. Finally, the SNIa nucleosynthesis is calculated using the obtained abundances as seeds. We obtain solar to supersolar abundances for p-nuclei with A &gt; 96. Our models show that SNIa are a viable p-process production site.
Binary black holes in young star clusters: the impact of metallicity
Authors: Di Carlo Ugo N , Mapelli Michela , Giacobbo Nicola , Spera Mario , Bouffanais Yann , Rastello Sara , Santoliquido Filippo , Pasquato Mario , Ballone Alessandro , Trani Alessandro A , Torniamenti Stefano , Haardt Francesco 
Published: July 2020

ABSTRACT
Young star clusters are the most common birthplace of massive stars and are dynamically active environments. Here, we study the formation of black holes (BHs) and binary black holes (BBHs) in young star clusters, by means of 6000 N-body simulations coupled with binary population synthesis. We probe three different stellar metallicities (Z = 0.02, 0.002, and 0.0002) and two initial-density regimes (density at the half-mass radius ρh ≥ 3.4 × 104 and ≥1.5 × 102 M⊙ pc−3 in dense and loose star clusters, respectively). Metal-poor clusters tend to form more massive BHs than metal-rich ones. We find ∼6, ∼2, and &lt;1 per cent of BHs with mass mBH &gt; 60 M⊙ at Z = 0.0002, 0.002, and 0.02, respectively. In metal-poor clusters, we form intermediate-mass BHs with mass up to ∼320 M⊙. BBH mergers born via dynamical exchanges (exchanged BBHs) can be more massive than BBH mergers formed from binary evolution: the former (latter) reach total mass up to ∼140 M⊙ (∼80 M⊙). The most massive BBH merger in our simulations has primary mass ∼88 M⊙, inside the pair-instability mass gap, and a mass ratio of ∼0.5. Only BBHs born in young star clusters from metal-poor progenitors can match the masses of GW 170729, the most massive event in first and second observing run (O1 and O2), and those of GW 190412, the first unequal-mass merger. We estimate a local BBH merger rate density ∼110 and ∼55 Gpc−3 yr−1, if we assume that all stars form in loose and dense star clusters, respectively.
A new approach to modelling gamma-ray burst afterglows: using Gaussian processes to account for the systematics
Authors: Aksulu M D , Wijers R A M J , van Eerten H J , van der Horst A J 
Published: July 2020

ABSTRACT
The afterglow emission from gamma-ray bursts (GRBs) is a valuable source of information to understand the physics of these energetic explosions. The fireball model has become the standard to describe the evolution of the afterglow emission over time and frequency. Because of recent developments in the theory of afterglows and numerical simulations of relativistic outflows, we are able to model the afterglow emission with realistic dynamics and radiative processes. Although the models agree with observations remarkably well, the afterglow emission still contains additional physics, instrumental systematics, and propagation effects that make the modelling of these events challenging. In this work, we present a new approach to modelling GRB afterglows, using Gaussian processes (GPs) to take into account systematics in the afterglow data. We show that, using this new approach, it is possible to obtain more reliable estimates of the explosion and microphysical parameters of GRBs. We present fit results for five long GRBs and find a preliminary correlation between the isotropic energetics and opening angles of GRBs, which confirms the idea of a common energy reservoir for the kinetic energy of long GRBs.
RNA-tethering assay and eIF4G:eIF4A obligate dimer design uncovers multiple eIF4F functional complexes
Authors: Robert Francis , Cencic Regina , Cai Renying , Schmeing T Martin , Pelletier Jerry 
Published: July 2020

AbstractEukaryotic cellular mRNAs possess a 5′ cap structure (m7GpppN) which plays a critical role in translation initiation mediated by eukaryotic initiation factor (eIF) 4F. The heterotrimeric eIF4F complex possesses several activities imparted by its subunits that include cap recognition (by eIF4E), RNA unwinding (eIF4A), and factor/ribosome recruitment (eIF4G). Mammalian cells have paralogs of all three eIF4F subunits and it remains an open question as to whether these all can participate in the process of ribosome recruitment. To query the activities of the eIF4F subunits in translation initiation, we adopted an RNA-tethering assay in which select subunits are recruited to a specific address on a reporter mRNA template. We find that all eIF4F subunits can participate in the initiation process. Based on eIF4G:eIF4A structural information, we also designed obligate dimer pairs to probe the activity of all combinations of eIF4G and eIF4A paralogs. We demonstrate that both eIF4GI and eIF4GII can associate with either eIF4A1 or eIF4A2 to recruit ribosomes to mRNA templates. In combination with eIF4E and eIF4E3, our results indicate the presence of up to eight eIF4F complexes that can operate in translation initiation.