bluuebunny/crossref_metadata_2025 huggingface dataset:
P118 The 134-year-old problem meets the 1-year-old problem: lessons learned in managing acute appendicitis during the COVID era
Authors: Fernando Sherwin , Sarma Diwakar Ryali
Published: April 2021

Introduction

The Right Iliac Fossa Pain Treatment (RIFT) study highlighted the rate of negative appendicectomies in the UK as one third of all procedures. However, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2/COVID) pandemic has changed surgical practice. New practices in the COVID era have changed the rate of negative appendicectomies.

Methods

A retrospective analysis was conducted of patients admitted with appendicitis from March 2020 to June 2020.

Patient Demographics

58 patients were identified, 43 (74%) were adults and 15 (26%) were children. The median age of the adults was 33 (range 18-80) and the median American Society of Anaesthetists (ASA) grading was 1. The median age of children was 11 (range 4-17) and all were ASA grade 1.

Results

73.8% (31) of adult patients had a Computerised Tomography (CT) scan as part of their workup. 40% of paediatric patients underwent an ultrasound scan of the abdomen whilst the remaining 60% were diagnosed clinically. The open approach was favoured in both cohorts (39.5% and 46.7% respectively). No negative appendicectomies were performed.

Conclusion

COVID19 has changed practice resulting in better outcomes for colorectal units. Further studies (COVID SURG and COVID HAREM) are needed to fully assess the role of imaging in reducing the number of negative appendicectomies.
Starting an aortic valve repair program: is it worthwhile? Aortic valve repair compared to replacement
Authors: Meuris Bart , Vervoort Dominique , De Praetere Herbert , Rex Steffen , Van De Bruaene Alexander , Herijgers Paul , Rega Filip , Verbrugghe Peter
Published: April 2021

OBJECTIVES

Increasing evidence suggests that aortic valve (AV) repair may have better long-term outcomes than AV replacement for aortic insufficiency. However, most literature is limited to centres of excellence and has not sufficiently been replicated in nascent programs. This single-centre experience of a newly established AV repair program aims to compare short-term outcomes of AV sparing versus replacement surgery.

METHODS

A retrospective cohort study of patients who underwent elective surgery for aortic regurgitation or aortic root dilatation at the Leuven University Hospital between 2013 and 2018 was performed. Patients with a critically ill presentation, endocarditis, aortic stenosis or requiring redo surgery were excluded. Patients were assigned to repair versus replacement based on preoperative intention to preserve the AV. Nearest neighbour propensity score matching was performed to compare both groups. Safety (mortality, morbidity), efficiency (cross-clamp and bypass times) and efficacy end points (repair rate, postoperative echocardiography) were compared.

RESULTS

One hundred and seven patients underwent AV surgery (48 repair, 59 replacement), from which 2 groups of 23 matched patients were created. There were 1 death and 2 reoperations after repair and no death and 1 reoperation after replacement. Extracorporeal circulation and aortic cross-clamp time were significantly longer while ventilation and total hospital stay were significantly shorter after AV repair. Echocardiographic follow-up showed comparable aortic regurgitation but lower transvalvular gradients after repair. Freedom from major complications was comparable in both cohorts.

CONCLUSIONS

Early results suggest the feasibility of replicating experienced centres’ perioperative and short-term outcomes in nascent programs.
A comprehensive history of motility and Archaellation in Archaea
Authors: Jarrell Ken F , Albers Sonja-Verena , Machado J Nuno de Sousa
Published: April 2021

Each of the three Domains of life, Eukarya, Bacteria and Archaea, have swimming structures that were all originally called flagella, despite the fact that none were evolutionarily related to either of the other two. Surprisingly, this was true even in the two prokaryotic Domains of Bacteria and Archaea. Beginning in the 1980s, evidence gradually accumulated that convincingly demonstrated that the motility organelle in Archaea was unrelated to that found in Bacteria, but surprisingly shared significant similarities to type IV pili. This information culminated in the proposal, in 2012, that the ‘archaeal flagellum’ be assigned a new name, the archaellum. In this review, we provide a historical overview on archaella and motility research in Archaea, beginning with the first simple observations of motile extreme halophilic archaea a century ago up to state-of-the-art cryo-tomography of the archaellum motor complex and filament observed today. In addition to structural and biochemical data which revealed the archaellum to be a type IV pilus-like structure repurposed as a rotating nanomachine (Beeby et al. 2020), we also review the initial discoveries and subsequent advances using a wide variety of approaches to reveal: complex regulatory events that lead to the assembly of the archaellum filaments (archaellation); the roles of the various archaellum proteins; key post-translational modifications of the archaellum structural subunits; evolutionary relationships; functions of archaella other than motility and the biotechnological potential of this fascinating structure. The progress made in understanding the structure and assembly of the archaellum is highlighted by comparing early models to what is known today.
Enumerating Non-Stable Vector Bundles
Authors: DU Peng
Published: April 2021

In this article, we establish a motivic analog of an enumeration result of James–Thomas [ 28] on non-stable vector bundles in topological setting. Using this, we obtain results on enumeration of projective modules of rank $d$ over a smooth affine $k$-algebra $A$ of dimension $d$, recovering in particular results of Suslin and Bhatwadekar on cancellation of such vector bundles. Admitting a conjecture of Asok and Fasel, we prove cancellation of such vector bundles of rank $d-1$ if the base field $k$ is algebraically closed. We also explore the cancellation properties of symplectic vector bundles.
Population-Based Estimates of SARS-CoV-2 Seroprevalence in Houston, Texas as of September 2020
Authors: Symanski Elaine , Ensor Katherine B , Piedra Pedro A , Sheth Komal , Caton Kelsey , Williams Stephen L , Persse David , Banerjee Deborah , Hopkins Loren
Published: April 2021

Background

In contrast to studies that relied on volunteers or convenience sampling, there are few population-based severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) seroprevalence investigations and most were conducted early in the pandemic. The health department of the fourth largest US city recognized that sound estimates of viral impact were needed to inform decision making.

Methods

Adapting standardized disaster research methodology, in September 2020 the city was divided into high and low strata based on reverse-transcriptase polymerase chain reaction (RT-PCR) positivity rates; census block groups within each stratum were randomly selected with probability proportional to size, followed by random selection of households within each group. Using 2 immunoassays, the proportion of infected individuals was estimated for the city, by positivity rate and sociodemographic and other characteristics. The degree of underascertainment of seroprevalence was estimated based on RT-PCR–positive cases.

Results

Seroprevalence was estimated to be 14% with near 2-fold difference in areas with high (18%) versus low (10%) RT-PCR positivity rates and was 4 times higher compared to case-based surveillance data.

Conclusions

Seroprevalence was higher than previously reported and greater than estimated from RT-PCR data. Results will be used to inform public health decisions about testing, outreach, and vaccine rollout.
Phenotyping Angiotensin-Converting Enzyme in Blood: A Necessary Approach for Precision Medicine
Authors: Samokhodskaya Larisa M , Jain Mark S , Kurilova Olga V , Bobkov Alexander P , Kamalov Armais A , Dudek Steven M , Danilov Sergei M
Published: April 2021

Background

Angiotensin-converting enzyme (ACE) metabolizes a number of important peptides participating in blood pressure regulation and vascular remodeling. Elevated ACE expression in tissues (which is generally reflected by ACE in blood) is associated with increased risk of cardiovascular diseases. Elevated ACE in blood is also a marker for granulomatous diseases.

Methods

We applied our novel approach—ACE phenotyping—to characterize serum ACE in 300 unrelated patients and to establish normal values for ACE levels. ACE phenotyping includes (a) determination of ACE activity with 2 substrates (Z-Phe-His-Leu [ZPHL] and Hip-His-Leu [HHL]), (b) calculation of a ratio for hydrolysis of ZPHL and HHL, and (c) quantification of ACE immunoreactive protein levels and ACE conformation with a set of monoclonal antibodies (mAbs) to ACE.

Results

Only a combination of ACE activity determination with 2 substrates and quantification of the amount of ACE immunoreactive protein with mAbs 1G12 and 9B9 allows for the unequivocal detection of the presence of ACE inhibitors in the blood. After excluding such subjects, we were able to establish normal values of ACE in healthy populations: 50%–150% from control pooled serum. This ACE phenotyping approach in screening format with special attention to outliers can also identify patients with various mutations in ACE and may help to identify the as yet unknown ACE secretase or other mechanistic details of precise regulation of ACE expression.

Conclusions

ACE phenotyping is a promising new approach with potential clinical significance to advance precision medicine screening techniques by establishing different risk groups based on ACE phenotype.
Time budgets of group-housed pigs in relation to social aggression and production
Authors: O′Malley Carly I , Steibel Juan P , Bates Ronald O , Ernst Catherine W , Siegford Janice M
Published: April 2021

Commercial producers house growing pigs by sex and weight to allow for efficient use of resources and provide pigs the welfare benefits of interacting with their conspecifics and more freedom of movement. However, the introduction of unfamiliar pigs can cause increased aggression for 24 to 48 h as pigs establish social relationships. To address this issue, a better understanding of pig behavior is needed. The objectives of this study were to quantify time budgets of pigs following introduction into a new social group and how these changed over time and to investigate how social aggression influences the overall time budgets and production parameters. A total of 257 grow-finish Yorkshire barrows across 20 pens were introduced into new social groups at 10 wk of age (~23 kg) and observed for aggression and time budgets of behavior at four periods: immediately after introduction and 3, 6, and 9 wk later. Pigs were observed for the duration of total aggression and initiated aggression (s) for 9 h after introduction and for 4 h at 3, 6, and 9 wk later. Time budgets were created by scan sampling inactive, movement, ingestion, social, and exploration behaviors every 2 min for 4 h in the afternoon and summarizing the proportion of time each behavior was performed by period. The least square means of each behavior were compared across time points. Pigs spent most of their time inactive. In general, the greatest change in pig behavior was observed between introduction and week 3 (P < 0.003), with gradual changes throughout the study period as pigs became more inactive (week 3 vs. week 6: P = 0.209; week 6 vs. week 9: P = 0.007) and spent less time on other behaviors. Pigs’ nonaggressive behavior and production parameters were compared with aggression using generalized linear mixed models. The time pigs spent on nonaggressive behaviors was negatively related to aggression (P < 0.045) with few exceptions. Initiated aggression after introduction was negatively related to loin muscle area (P = 0.003). These results show how finishing pigs spend their time in commercial facilities and indicate that behavior continues to change for up to 9 wk after introduction into a new social group. Efforts to reduce chronic levels of aggression should focus on promoting nonaggressive behaviors, such as exploration and movement, after the initial fighting that occurs immediately after introduction has waned, and should be implemented for up to 9 wk after introduction into new social groups.
Two new species of fairy shrimps (Anostraca: Branchipodidae, Streptocephalidae) from the Northern Cape Province, Republic of South Africa
Authors: Rogers D Christopher , Meyer-Milne Elizabeth
Published: April 2021

We describe two new species of fairy shrimp from the Northern Cape Province, Republic of South Africa. Both species are from arid inland regions, where little survey work for crustaceans has been conducted. Branchipodopsis transversusn. sp. is separated from congeners by the unique form of the male second antennae, which bear a transverse anterior lobe on the anteromedial projection of the proximal antennomere. Streptocephalus valkyrien. sp. is unique among members of the genus in that its primary diagnostic character is the presence of a pronounced spiniform ‘horn’ on the posterolateral corner of the female’s head. The male antennal appendages are readily diagnosed by the large spines on the ‘palmar; region of the ‘hand.’
Intraoperative assessment of femoral head perfusion during surgical hip dislocation for slipped capital femoral epiphysis
Authors: Michalopoulos Adrian , Spelman Christopher , Balakumar Jitendra , Slattery David
Published: April 2021

Avascular necrosis is the most devastating complication of slipped capital femoral epiphysis, leading to collapse of the femoral head, increased risk of osteoarthritis and the requirement of early total hip arthroplasty. It is believed that intraoperative femoral head perfusion assessment may be an accurate predictor of post-operative avascular necrosis (radiographic collapse). At our institution, femoral head perfusion is assessed intraoperatively during all sub-capital realignment procedures. We hypothesize that our method is accurate in predicting the risk of developing post-operative avascular necrosis. In this retrospective study, we collected data from all patients that had intraoperative blood flow measurements during sub-capital realignment procedures. We correlated this with long-term radiographs looking for radiographic collapse. The intraoperative femoral head perfusion assessments during sub-capital realignment procedures for slipped capital femoral epiphysis at our institution, between January 2015 and March 2020 inclusive were assessed for reliability. In total, 26 of 35 patients had intraoperative femoral head perfusion present. Only 2 (8%) of these patients developed radiographic collapse. In contrast, 7 (78%) of the 9 patients who did not have femoral head perfusion present intraoperatively developed radiographic collapse, indicating that our method may be reliable in predicting a patient’s post-operative risk of developing avascular necrosis.
Field Borders Provide Winter Refuge for Beneficial Predators and Parasitoids: A Case Study on Organic Farms
Authors: Clem C Scott , Harmon-Threatt Alexandra N
Published: April 2021

Semi-natural field borders are frequently used in midwestern U.S. sustainable agriculture. These habitats are meant to help diversify otherwise monocultural landscapes and provision them with ecosystem services, including biological control. Predatory and parasitic arthropods (i.e., potential natural enemies) often flourish in these habitats and may move into crops to help control pests. However, detailed information on the capacity of semi-natural field borders for providing overwintering refuge for these arthropods is poorly understood. In this study, we used soil emergence tents to characterize potential natural enemy communities (i.e., predacious beetles, wasps, spiders, and other arthropods) overwintering in cultivated organic crop fields and adjacent field borders. We found a greater abundance, species richness, and unique community composition of predatory and parasitic arthropods in field borders compared to arable crop fields, which were generally poorly suited as overwintering habitat. Furthermore, potential natural enemies tended to be positively associated with forb cover and negatively associated with grass cover, suggesting that grassy field borders with less forb cover are less well-suited as winter refugia. These results demonstrate that semi-natural habitats like field borders may act as a source for many natural enemies on a year-to-year basis and are important for conserving arthropod diversity in agricultural landscapes.
Forecasting Loan Default in Europe with Machine Learning
Authors: Barbaglia Luca , Manzan Sebastiano , Tosetti Elisa
Published: April 2021

We use a dataset of 12 million residential mortgages to investigate the loan default behavior in several European countries. We model the default occurrence as a function of borrower characteristics, loan-specific variables, and local economic conditions. We compare the performance of a set of machine learning algorithms relative to the logistic regression, finding that they perform significantly better in providing predictions. The most important variables in explaining loan default are the interest rate and the local economic characteristics. The existence of relevant geographical heterogeneity in the variable importance points at the need for regionally tailored risk-assessment policies in Europe.
Delivery of Financial Navigation Services within National Cancer Institute-Designated Cancer Centers
Authors: de Moor Janet S , Mollica Michelle , Sampson Annie , Adjei Brenda , Weaver Sallie J , Geiger Ann M , Kramer Barnett S , Grenen Emily , Miscally Memi , Ciolino Henry P
Published: April 2021

Background

Cancer Centers have a responsibility to help patients manage the costs of their cancer treatment. This article describes the availability of financial navigation services within the National Cancer Institute (NCI)-Designated Cancer Centers.

Methods

Data were obtained from the NCI Survey of Financial Navigation Services and Research, an online survey administered to NCI-Designated Cancer Centers from July to September 2019. Of the 62 eligible Centers, 57 completed all or most of the survey, for a response rate of 90.5%.

Results

Nearly all Cancer Centers reported providing help with applications for pharmaceutical assistance programs and medical discounts (96.5%), health insurance coverage (91.2%), assistance with non-medical costs (96.5%), and help understanding medical bills and out-of-pocket costs (85.9%). Although other services were common, in some cases they were only available to certain patients. These services included direct financial assistance with medical and non-medical costs and referrals to outside organizations for financial assistance. The least common services included medical debt management (63.2%), detailed discussions about the cost of treatment (54.4%), and guidance about legal protections (50.1%). Providing treatment cost transparency to patients was reported as a common challenge: 71.9% of Centers agreed or strongly agreed that it is difficult to determine how much a cancer patient’s treatment will cost and 70.2% of oncologists are reluctant to discuss financial issues with patients.

Conclusions

Cancer Centers provide many financial services and resources. However, there remains a need to build additional capacity to deliver comprehensive financial navigation services and to understand the extent to which patients are referred and helped by these services.
Characterization ofProtothecaCYP51/ERG11 as a possible target for therapeutic drugs
Authors: Watanabe Takahisa , Ishikawa Tomohiro , Sato Hirotaka , Hirose Noriyuki , Nonaka Lisa , Matsumura Kaori , Masubuchi Akira , Nishimura Kazuko , Masuda Michiaki
Published: April 2021

Prototheca spp. are achlorophyllous algae, ubiquitous in nature. An increasing number of human and animal cases of Prototheca infection (protothecosis) are reported, and antifungal azoles, which inhibit sterol 14α-demethylase (CYP51/ERG11) involved in ergosterol biosynthesis, have empirically been used for the treatment of protothecosis. Although Prototheca, like fungi, has ergosterol in the cell membrane, efficacy of the antifungal azoles in the treatment of protothecosis is controversial. For investigating the interaction of azole drugs with Prototheca CYP51/ERG11, the CYP51/ERG11 genomic genes of four strains of P. wickerhamii and one strain each of P. cutis and P. miyajii were isolated and characterized in this study. Compared with the CYP51/ERG11 gene of chlorophyllous Auxenochlorella Protothecoides, it is possible that ProtothecaCYP51/ERG11 gene, whose exon-intron structure appeared to be species-specific, lost introns associated with the loss of photosynthetic activity. Analysis of the deduced amino acid sequences revealed that Prototheca CYP51/ERG11 and fungal CYP51/ERG11 are phylogenetically distant from each other although their overall structures are similar. Our basic in silico studies predicted that antifungal azoles could bind to the catalytic pocket of Prototheca CYP51/ERG11. It was also suggested that amino acid residues away from the catalytic pocket might affect the drug susceptibility. The results of this study may provide useful insights into the phylogenetic taxonomy of Prototheca spp. in relationship to the CYP51/ERG11 structure and development of novel therapeutic drugs for the treatment of protothecosis.

Lay Summary

Cases of infection by microalgae of Prototheca species are increasing. However, effective treatment has not been established yet. In this study, gene and structure of Prototheca’s CYP51/ERG11, an enzyme which might serve as a target for therapeutic drugs, were characterized for the first time.
The first Hubble diagram and cosmological constraints using superluminous supernovae
Authors: Inserra C , Sullivan M , Angus C R , Macaulay E , Nichol R C , Smith M , Frohmaier C , Gutiérrez C P , Vicenzi M , Möller A , Brout D , Brown P J , Davis T M , D’Andrea C B , Galbany L , Kessler R , Kim A G , Pan Y-C , Pursiainen M , Scolnic D , Thomas B P , Wiseman P , Abbott T M C , Annis J , Avila S , Bertin E , Brooks D , Burke D L , Carnero Rosell A , Carrasco Kind M , Carretero J , Castander F J , Cawthon R , Desai S , Diehl H T , Eifler T F , Finley D A , Flaugher B , Fosalba P , Frieman J , Garcia-Bellido J , Gaztanaga E , Gerdes D W , Giannantonio T , Gruen D , Gruendl R A , Gschwend J , Gutierrez G , Hollowood D L , Honscheid K , James D J , Krause E , Kuehn K , Kuropatkin N , Li T S , Lidman C , Lima M , Maia M A G , Marshall J L , Martini P , Menanteau F , Miquel R , Plazas Malagón A A , Romer A K , Roodman A , Sako M , Sanchez E , Scarpine V , Schubnell M , Serrano S , Sevilla-Noarbe I , Soares-Santos M , Sobreira F , Suchyta E , Swanson M E C , Tarle G , Thomas D , Tucker D L , Vikram V , Walker A R , Zhang Y , Asorey J , Calcino J , Carollo D , Glazebrook K , Hinton S R , Hoormann J K , Lewis G F , Sharp R , Swann E , Tucker B E ,   (DES Collaboration)
Published: April 2021

We present the first Hubble diagram of superluminous supernovae (SLSNe) out to a redshift of two, together with constraints on the matter density, ΩM, and the dark energy equation-of-state parameter, w(≡p/ρ). We build a sample of 20 cosmologically useful SLSNe I based on light curve and spectroscopy quality cuts. We confirm the robustness of the peak–decline SLSN I standardization relation with a larger data set and improved fitting techniques than previous works. We then solve the SLSN model based on the above standardization via minimization of the χ2 computed from a covariance matrix that includes statistical and systematic uncertainties. For a spatially flat Λ cold dark matter (ΛCDM) cosmological model, we find $\Omega _{\rm M}=0.38^{+0.24}_{-0.19}$, with an rms of 0.27 mag for the residuals of the distance moduli. For a w0waCDM cosmological model, the addition of SLSNe I to a ‘baseline’ measurement consisting of Planck temperature together with Type Ia supernovae, results in a small improvement in the constraints of w0 and wa of 4 per cent. We present simulations of future surveys with 868 and 492 SLSNe I (depending on the configuration used) and show that such a sample can deliver cosmological constraints in a flat ΛCDM model with the same precision (considering only statistical uncertainties) as current surveys that use Type Ia supernovae, while providing a factor of 2–3 improvement in the precision of the constraints on the time variation of dark energy, w0 and wa. This paper represents the proof of concept for superluminous supernova cosmology, and demonstrates they can provide an independent test of cosmology in the high-redshift (z > 1) universe.
Searching for new solar twins: The Inti survey for the Northern Sky
Authors: Yana Galarza Jhon , López-Valdivia Ricardo , Lorenzo-Oliveira Diego , Reggiani Henrique , Meléndez Jorge , Gamarra-Sánchez Daniel , Flores Matias , Portal-Rivera Jerry , Miquelarena Paula , Ponte Geisa , Schlaufman Kevin C , Vargas Auccalla Teófilo
Published: April 2021

Solar twins are key in different areas of astrophysics, however only just over a hundred were identified and well-studied in the last two decades. In this work, we take advantage of the very precise Gaia (DR2/EDR3), Tycho, and 2MASS photometric systems to create the ${{Inti}}$ survey of new solar twins in the Northern Hemisphere. The spectra of our targets were initially obtained with spectrographs of moderate resolution (ARCES and Goodman spectrographs with R  = 31 500 and 11 930, respectively) to find the best solar twin candidates and then observed at McDonald Observatory with higher resolving power (TS23, R  = 60 000) and signal-to-noise ratio (SNR ∼ 300–500). The stellar parameters were estimated through the differential spectroscopic equilibrium relative to the Sun, which allow us to achieve a high internal precision (σ(Teff)  = 15 K, σ(log g)  = 0.03 dex, σ($\rm {[Fe/H]}$)  = 0.01 dex, and σ(vt)  = 0.03 km s−1). We propose a new class of stars with evolution similar to the Sun: solar proxy, which is useful to perform studies related to the evolution of the Sun, such as its rotational and magnetic evolution. Its definition is based on metallicity (−0.15 dex ≤ $\rm {[Fe/H]}$ ≤  + 0.15 dex) and mass (0.95 M⊙ ≤ M ≤ 1.05 M⊙) constraints, thus assuring that the star follows a similar evolutionary path as the Sun along the main sequence. Based on this new definition, we report 70 newly identified solar proxies, 46 solar analogues, and 13 solar-type stars. In addition, we identified nine close solar twins whose stellar parameters are the most similar to those of the Sun.
White dwarfs with planetary remnants in the era of Gaia – I. Six emission line systems
Authors: Gentile Fusillo N P , Manser C J , Gänsicke Boris T , Toloza O , Koester D , Dennihy E , Brown W R , Farihi J , Hollands M A , Hoskin M J , Izquierdo P , Kinnear T , Marsh T R , Santamaría-Miranda A , Pala A F , Redfield S , Rodríguez-Gil P , Schreiber M R , Veras Dimitri , Wilson D J
Published: April 2021

White dwarfs with emission lines from gaseous debris discs are among the rarest examples of planetary remnant hosts, but at the same time they are key objects for studying the final evolutionary stage of planetary systems. Making use of the large number of white dwarfs identified in Gaia Data Release 2 (DR2), we are conducting a survey of planetary remnants and here we present the first results of our search: six white dwarfs with gaseous debris discs. This first publication focuses on the main observational properties of these objects and highlights their most unique features. Three systems in particular stand out: WD J084602.47+570328.64 displays an exceptionally strong infrared excess that defies the standard model of a geometrically thin, optically thick dusty debris disc; WD J213350.72+242805.93 is the hottest gaseous debris disc host known with $\mbox{$T_{\mathrm{eff}}$}=29\,282$ K; and WD J052914.32–340108.11 in which we identify a record number of 51 emission lines from five elements. These discoveries shed light on the underlying diversity in gaseous debris disc systems and bring the total number of these objects to 21. With these numbers we can now start looking at the properties of these systems as a class of objects rather than on a case-by-case basis.
Fundamental properties of stars from Kepler and Gaia data: parallax offset and revised scaling relations
Authors: Yıldız M , Örtel S
Published: April 2021

Data from the space missions Gaia, Kepler, CoRoT and TESS, make it possible to compare parallax and asteroseismic distances. From the ratio of two densities ρsca/ρπ, we obtain an empirical relation fΔν between the asteroseismic large frequency separation and mean density, which is important for more accurate stellar mass and radius. This expression for main-sequence (MS) and subgiant stars with K-band magnitude is very close to the one obtained from interior MS models by Yıldız, Çelik & Kayhan. We also discuss the effects of effective temperature and parallax offset as the source of the difference between asteroseismic and non-asteroseismic stellar parameters. We have obtained our best results for about 3500 red giants (RGs) by using 2MASS data and model values for fΔν from Sharma et al. Another unknown scaling parameter $f_{\nu _{\rm max}}$ comes from the relationship between the frequency of maximum amplitude and gravity. Using different combinations of $f_{\nu _{\rm max}}$ and the parallax offset, we find that the parallax offset is generally a function of distance. The situation where this slope disappears is accepted as the most reasonable solution. By a very careful comparison of asteroseismic and non-asteroseismic parameters, we obtain very precise values for the parallax offset and $f_{\nu _{\rm max}}$ for RGs of –0.0463 ± 0.0007 mas and 1.003 ± 0.001, respectively. Our results for mass and radius are in perfect agreement with those of APOKASC-2: the mass and radius of ∼3500 RGs are in the range of about 0.8–1.8 M⊙ (96 per cent) and 3.8–38 R⊙, respectively.
Synthetic RGB photometry of bright stars: definition of the standard photometric system and UCM library of spectrophotometric spectra
Authors: Cardiel Nicolás , Zamorano Jaime , Bará Salvador , Sánchez de Miguel Alejandro , Cabello Cristina , Gallego Jesús , García Lucía , González Rafael , Izquierdo Jaime , Pascual Sergio , Robles José , Sánchez Ainhoa , Tapia Carlos
Published: April 2021

Although the use of RGB photometry has exploded in the last decades due to the advent of high-quality and inexpensive digital cameras equipped with Bayer-like colour filter systems, there is surprisingly no catalogue of bright stars that can be used for calibration purposes. Since due to their excessive brightness, accurate enough spectrophotometric measurements of bright stars typically cannot be performed with modern large telescopes, we have employed historical 13-colour medium-narrow-band photometric data, gathered with quite reliable photomultipliers, to fit the spectrum of 1346 bright stars using stellar atmosphere models. This not only constitutes a useful compilation of bright spectrophotometric standards well spread in the celestial sphere, the UCM library of spectrophotometric spectra, but allows the generation of a catalogue of reference RGB magnitudes, with typical random uncertainties ∼0.01 mag. For that purpose, we have defined a new set of spectral sensitivity curves, computed as the median of 28 sets of empirical sensitivity curves from the literature, that can be used to establish a standard RGB photometric system. Conversions between RGB magnitudes computed with any of these sets of empirical RGB curves and those determined with the new standard photometric system are provided. Even though particular RGB measurements from single cameras are not expected to provide extremely accurate photometric data, the repeatability and multiplicity of observations will allow access to a large amount of exploitable data in many astronomical fields, such as the detailed monitoring of light pollution and its impact on the night sky brightness, or the study of meteors, Solar system bodies, variable stars, and transient objects. In addition, the RGB magnitudes presented here make the sky an accessible and free laboratory for the calibration of the cameras themselves.
Accurate 3D fireball trajectory and orbit calculation using the 3D-firetoc automatic Python code
Authors: Peña-Asensio Eloy , Trigo-Rodríguez Josep Maria , Gritsevich Maria , Rimola Albert
Published: April 2021

The disruption of asteroids and comets produces cm-sized meteoroids that end up impacting the Earth’s atmosphere and producing bright fireballs that might have associated shock waves or, in geometrically favourable occasions excavate craters that put them into unexpected hazardous scenarios. The astrometric reduction of meteors and fireballs to infer their atmospheric trajectories and heliocentric orbits involves a complex and tedious process that generally requires many manual tasks. To streamline the process, we present a software package called SPMN 3D Fireball Trajectory and Orbit Calculator (3D-firetoc), an automatic Python code for detection, trajectory reconstruction of meteors, and heliocentric orbit computation from video recordings. The automatic 3D-firetoc package comprises of a user interface and a graphic engine that generates a realistic 3D representation model, which allows users to easily check the geometric consistency of the results and facilitates scientific content production for dissemination. The software automatically detects meteors from digital systems, completes the astrometric measurements, performs photometry, computes the meteor atmospheric trajectory, calculates the velocity curve, and obtains the radiant and the heliocentric orbit, all in all quantifying the error measurements in each step. The software applies corrections such as light aberration, refraction, zenith attraction, diurnal aberration, and atmospheric extinction. It also characterizes the atmospheric flight and consequently determines fireball fates by using the α − β criterion that analyses the ability of a fireball to penetrate deep into the atmosphere and produce meteorites. We demonstrate the performance of the software by analysing two bright fireballs recorded by the Spanish Fireball and Meteorite Network (SPMN).
E. coli RNase I exhibits a strong Ca2+-dependent inherent double-stranded RNase activity
Authors: Grünberg Sebastian , Coxam Baptiste , Chen Tien-Hao , Dai Nan , Saleh Lana , Corrêa Ivan R , Nichols Nicole M , Yigit Erbay
Published: April 2021

Since its initial characterization, Escherichia coli RNase I has been described as a single-strand specific RNA endonuclease that cleaves its substrate in a largely sequence independent manner. Here, we describe a strong calcium (Ca2+)-dependent activity of RNase I on double-stranded RNA (dsRNA), and a Ca2+-dependent novel hybridase activity, digesting the RNA strand in a DNA:RNA hybrid. Surprisingly, Ca2+ does not affect the activity of RNase I on single stranded RNA (ssRNA), suggesting a specific role for Ca2+ in the modulation of RNase I activity. Mutation of a previously overlooked Ca2+ binding site on RNase I resulted in a gain-of-function enzyme that is highly active on dsRNA and could no longer be stimulated by the metal. In summary, our data imply that native RNase I contains a bound Ca2+, allowing it to target both single- and double-stranded RNAs, thus having a broader substrate specificity than originally proposed for this traditional enzyme. In addition, the finding that the dsRNase activity, and not the ssRNase activity, is associated with the Ca2+-dependency of RNase I may be useful as a tool in applied molecular biology.
Liquidity traps in a monetary union
Authors: Kollmann Robert
Published: April 2021

The closed economy macro literature has shown that a liquidity trap can result from the self-fulfilling expectation that future inflation and output will be low. This paper investigates expectations-driven liquidity traps in a two-country New Keynesian model of a monetary union. In the model here, a rise in government purchases in an individual country has a weak effect on GDP in the rest of the union. The results here cast doubt on the view that, in the current era of ultra-low interest rates, a rise in fiscal spending by Euro Area (EA) core countries would significantly boost GDP in the EA periphery.
Clinical Presentation, Management, and Outcomes of Patients With Brain Abscess due to Nocardia Species
Authors: Corsini Campioli Cristina , Castillo Almeida Natalia E , O’Horo John C , Challener Douglas , Go John Raymond , DeSimone Daniel C , Sohail M Rizwan
Published: April 2021

Background

Nocardial brain abscesses are rare, and published literature describing brain abscesses due to Nocardia species is limited to individual case reports or small series. We report one of the largest contemporary retrospective studies describing risk factors, diagnostic evaluation, management, and outcomes of nocardial brain abscess.

Methods

Retrospective review of all adults with brain abscess due to culture-confirmed Nocardia species at our institution between January 1, 2009, and June 30, 2020.

Results

Overall, 24 patients had nocardial brain abscesses during the study period. The median age at presentation was 64 years, and 62.5% were immunocompromised. Pulmonary and cutaneous infections were the most common primary sites of nocardial infection. All 24 patients had magnetic resonance imaging performed, and the frontal lobe was the most commonly involved. The most common organism isolated was Nocardia farcinica, followed by Nocardia wallacei and Nocardia cyriacigeorgica. Thirteen patients were managed with antimicrobial therapy alone, while 11 had both medical and surgical management. In all patients, dual therapy was recommended for the initial 6 weeks of treatment, and 22 patients received at least 1 oral agent as part of their final antibiotic regimen, predominantly trimethoprim-sulfamethoxazole and linezolid. Fourteen patients achieved complete clinical and radiographic resolution of infection.

Conclusions

Nocardia is an important cause of brain abscess in the immunocompromised host. Early diagnostic and therapeutic aspiration may help health care providers confirm the diagnosis, choose an appropriate antimicrobial regimen, and achieve source control.
Vertical changes in abundance, biomass and community structure of pelagic polychaetes down to 1000 m depths at Station K2 in the western subarctic Pacific Ocean covering the four seasons and day–night
Authors: Amei Kanako , Dobashi Ryo , Jimi Naoto , Kitamura Minoru , Yamaguchi Atsushi
Published: April 2021

Pelagic polychaetes are distributed from the sea surface to greater depths of the oceans worldwide, but little information is available regarding their ecology. This study investigated the vertical distribution of abundance, biomass and community structure of pelagic polychaetes at a single station in the western subarctic Pacific based on day–night vertical stratified samples collected from a 0 to 1000 m water column during four seasons covering 1 year. The polychaete abundance and biomass ranged from 0 to 757 ind. 1000 m−3 and 0–6.1 mg WW m−3, respectively. Ten pelagic polychaete species belonging to nine genera and six families were identified. From cluster analysis based on abundance, the polychaete community was divided into five communities. Each community occurred at different depth layers. Two surface groups seen at 0–200 m were dominated by two carnivorous species: Tomopteris septentrionalis and Typhloscolex muelleri. The deepest group, dominated by the particle feeder Pelagobia longicirrata, was seen at 500–1000 m. Two transition groups occurred in the intermediate depths. These vertical distributions of the pelagic polychaete communities were common throughout the season and day. Water mass, food availability and the oxygen minimum layer are put forth as environmental factors that affect the pelagic polychaete community.
Can Craniometry Play a Role in Cluster Headache Diagnosis? A Pilot Exploratory TC-3D Based Study
Authors: Russo Antonio , Silvestro Marcello , Vanore Laura , Capasso Raffaella , Siciliano Mattia , Tessitore Alessandro , Caranci Ferdinando , Tedeschi Gioacchino , Conforti Renata
Published: April 2021

Background

Since the pioneering reports of the so-called leonine face in cluster headache (CH) patients, cranial and facial features of these patients have been poorly investigated with conflicting results. We aimed to investigate whether abnormalities in craniometric measurements could characterize male CH patients and represent reliable and reproducible diagnostic biomarkers able to identify CH patients.

Methods

Brain CT images were recorded between 2018 and 2020 in 24 male patients with CH and in 24 matched healthy controls (HC). Then, craniometric measurements were obtained, and logistic regression and receiver operating characteristic curves analyses were used to identify the craniometric abnormalities able to distinguish CH patients from HC.

Results

Logistic regression analyses showed that frontal bone height and facial width were able to discriminate, one independently from the other, CH patients from HC with an overall accuracy of 77%. The optimal cutoff score in detecting the probable presence of CH was 11.50 cm for frontal bone height and 13.30 cm for facial width.

Discussion

In the present study we found, for the first time by means of brain 3D computed tomography approach, abnormal craniometric measurements in CH patients when compared with HC. The absence of differences in smoke and alcohol intake suggests that the observed craniometric abnormalities may represent a specific feature of CH patients.

Conclusion

The craniometric evaluation by means of brain 3D computed tomography could represent a widespread, noninvasive, and accurate tool to support CH diagnosis to avoid frequent misdiagnosis or delay in the diagnostic process.
Do Corticosteroid Injections for the Treatment of Pain Influence the Efficacy of Adenovirus Vector-Based COVID-19 Vaccines?
Authors: Lee Haewon , Punt Jennifer A , Patel Jaymin , Stojanovic Milan P , Duszynski Belinda , McCormick Zachary L ,   the Spine Intervention Society’s Patient Safety Committee
Published: April 2021

Myth

Corticosteroid injection for the treatment of pain is known to decrease the efficacy of the adenovirus vector-based vaccines for COVID-19.

Fact

There is currently no direct evidence to suggest that a corticosteroid injection before or after the administration of an adenovirus vector-based COVID-19 vaccine decreases the efficacy of the vaccine. However, based on the known timeline of hypothalamic-pituitary-adrenal axis suppression following epidural and intraarticular corticosteroid injections, and the timeline of the reported peak efficacy of the Janssen and AstraZeneca vaccines, physicians should consider timing an elective corticosteroid injection such that it is administered no less than 2 weeks prior to and no less than 2 weeks following a COVID-19 adenovirus vector-based vaccine dose, whenever possible. We emphasize the importance of risk/benefit analysis and shared decision making in determining the timing of corticosteroid injections for pain indications in relation to receipt of a COVID-19 vaccine given that patient-specific factors will vary.
Personal Wealth, Self-Employment, and Business Ownership
Authors: Bellon Aymeric , Cookson J Anthony , Gilje Erik P , Heimer Rawley Z
Published: April 2021

We study the effect of personal wealth on entrepreneurial decisions using data on mineral payments from Texas shale drilling to individuals throughout the United States. Large cash windfalls increase business formation by 0.8 to 2.1 percentage points, but do not affect transitions to self-employment. By contrast, cash windfalls significantly extend self-employment spells, but do not affect the duration of business ownership. Our findings help reconcile contrasting findings in prior work: liquidity constraints have different effects on entrepreneurial activity that may depend on the entrepreneur’s motivations.
Resolution of vascular inflammation in patients with new-onset giant cell arteritis: data from the RIGA study
Authors: Schönau Verena , Roth Jessica , Tascilar Koray , Corte Giulia , Manger Bernhard , Rech Juergen , Schmidt Daniela , Cavallaro Alexander , Uder Michael , Crescentini Filippo , Boiardi Luigi , Casali Massimiliano , Spaggiari Lucia , Galli Elena , Kuwert Torsten , Versari Annibale , Salvarani Carlo , Schett Georg , Muratore Francesco
Published: April 2021

Objectives

Efficacy evaluation of GCA treatment is primarily based on non-specific symptoms and laboratory markers. We aimed to assess the change in vascular inflammation in patients with large vessel (LV)-GCA under different treatments using [18F]FDG PET/CT.

Methods

Observational study on patients with new-onset, active LV-GCA starting treatment with either prednisolone monotherapy (PRED) or combination with MTX or tocilizumab (TOC). All patients underwent baseline and follow-up PET/CT. The aorta and its major branches were assessed using PET vascular activity score (PETVAS) by independent readers. Cumulative glucocorticoid doses and cessation of glucocorticoid treatment were documented in all patients.

Results

We included 88 LV-GCA patients, 27 were treated with PRED, 42 with MTX and 19 with TOC. PETVAS decreased from 18.9–8.0 units at follow-up in the overall population (P <0.001). PETVAS changes were numerically higher in patients receiving MTX (−12.3 units) or TOC (−11.7 units) compared with PRED (−8.7). Mean cumulative prednisolone dosages were 5637, 4418 and 2984 mg in patients treated with PRED, MTX and TOC (P =0.002). Risk ratios for glucocorticoid discontinuation at the time of follow-up PET/CT were 6.77 (95% CI: 1.01, 45.29; P =0.049) and 16.25 (95% CI: 2.60, 101.73; P =0.003) for MTX and TOC users compared with PRED users.

Conclusion

Treatment of LV-GCA inhibits vascular inflammation in the aorta and its major branches. While similar control of vascular inflammation was achieved with PRED, MTX and TOC treatments, TOC showed a strong glucocorticoid sparing effect, supporting the concept of initial combination therapy.
Population Genomics Reveals Molecular Determinants of Specialization to Tomato in the Polyphagous Fungal Pathogen Botrytis cinerea in France
Authors: Mercier Alex , Simon Adeline , Lapalu Nicolas , Giraud Tatiana , Bardin Marc , Walker Anne-Sophie , Viaud Muriel , Gladieux Pierre
Published: April 2021

Many fungal plant pathogens encompass multiple populations specialized on different plant species. Understanding the factors underlying pathogen adaptation to their hosts is a major challenge of evolutionary microbiology, and it should help to prevent the emergence of new specialized pathogens on novel hosts. Previous studies have shown that French populations of the gray mold pathogen Botrytis cinerea parasitizing tomato and grapevine are differentiated from each other, and have higher aggressiveness on their host of origin than on other hosts, indicating some degree of host specialization in this polyphagous pathogen. Here, we aimed at identifying the genomic features underlying the specialization of B. cinerea populations to tomato and grapevine. Based on whole genome sequences of 32 isolates, we confirmed the subdivision of B. cinerea pathogens into two genetic clusters on grapevine and another, single cluster on tomato. Levels of genetic variation in the different clusters were similar, suggesting that the tomato-specific cluster has not recently emerged following a bottleneck. Using genome scans for selective sweeps and divergent selection, tests of positive selection based on polymorphism and divergence at synonymous and nonsynonymous sites, and analyses of presence and absence variation, we identified several candidate genes that represent possible determinants of host specialization in the tomato-associated population. This work deepens our understanding of the genomic changes underlying the specialization of fungal pathogen populations.