bluuebunny/crossref_metadata_2025 huggingface dataset:
Dissociative single and double photoionization of biphenyl (C12H10) by soft X-rays in planetary nebulae
Authors: Quitián-Lara Heidy M , Fantuzzi Felipe , Oliveira Ricardo R , Nascimento Marco A C , Wolff Wania , Boechat-Roberty Heloisa M
Published: October 2020

Biphenyl (C12H10), or phenylbenzene, is an important building block of polycyclic aromatic hydrocarbons (PAHs), whose infrared spectral features are present in a variety of galactic and extragalactic sources. In this work, we use synchrotron radiation coupled with time-of-flight spectrometry to study the photoionization and photodissociation processes of biphenyl upon its interaction with soft X-ray photons at energies around the inner-shell C1s resonance. These results are compared with our previous studies with benzene (C6H6) and naphthalene (C10H8), and discussed in the context of four planetary nebulae featuring PAH infrared emission: BD+30○3639, NGC 7027, NGC 5315, and NGC 40. We show that the mass spectrum of biphenyl before the C1s resonance energy is dominated by single photoionization processes leading to C6H$_{5}^+$, C6H$_{4}\, ^{+\cdot}$, and C12H$_{10}\, ^{+\cdot}$, while after the resonance dissociation following multiple photoionization processes is dominant. The release of neutral C6H6 and C6H$_{5}\, ^\cdot$ species accounts for one of the most relevant dissociation processes starting from the doubly ionized biphenyl, indicating that heterolytic charge separation of the two phenyl rings is also achieved. By using quantum chemical calculations, we show that the biphenylic structure is a high-lying isomer of the singly and doubly ionized C12H10 species, whose minimum energy geometries are related to the acenaphthene molecule, composed of a C2-bridged naphthalene. Furthermore, we estimate the lifetime of biphenyl for 275 and 310 eV in photon-dominated regions of planetary nebulae. We discuss distinct processes that may enhance its lifetime and those of other small-sized PAHs in such astrophysical environments.
Polarimetric and radiative transfer modelling of HD 172555
Authors: Marshall Jonathan P , Cotton Daniel V , Scicluna Peter , Bailey Jeremy , Kedziora-Chudczer Lucyna , Bott Kimberly
Published: October 2020

The debris disc around HD 172555 was recently imaged in near-infrared polarized scattered light by the Very Large Telescope’s Spectro-Polarimetric High-contrast Exoplanet REsearch instrument. Here we present optical aperture polarization measurements of HD 172555 by the HIgh Precision Polarimetric Instrument (HIPPI), and its successor HIPPI-2 on the Anglo-Australian Telescope. We seek to refine constraints on the disc’s constituent dust grains by combining our polarimetric measurements with available infrared and millimetre photometry to model the scattered light and continuum emission from the disc. We model the disc using the 3D radiative transfer code hyperion, assuming the orientation and extent of the disc as obtained from the SPHERE observation. After correction for the interstellar medium contribution, our multiwavelength HIPPI/-2 observations (both magnitude and orientation) are consistent with the recent SPHERE polarization measurement with a fractional polarization p = 62.4  ±  5.2 ppm at 722.3 nm, and a position angle θ = 67°  ±  3°. The multiwavelength polarization can be adequately replicated by compact, spherical dust grains (i.e. from Mie theory) that are around 1.2 μm in size, assuming astronomical silicate composition, or 3.9 μm, assuming a composition derived from radiative transfer modelling of the disc. We were thus able to reproduce both the spatially resolved disc emission and polarization with a single grain composition model and size distribution.
Constraining delay time distribution of binary neutron star mergers from host galaxy properties
Authors: McCarthy Kevin S , Zheng Zheng , Ramirez-Ruiz Enrico
Published: October 2020

Gravitational wave (GW) observatories are discovering binary neutron star mergers (BNSMs), and in at least one event we were able to track it down in multiple wavelengths of light, which allowed us to identify the host galaxy. Using a catalogue of local galaxies with inferred star formation histories and adopting a BNSM delay time distribution (DTD) model, we investigate the dependence of BNSM rate on an array of galaxy properties. Compared to the intrinsic property distribution of galaxies, that of BNSM host galaxies is skewed towards galaxies with redder colour, lower specific star formation rate, higher luminosity, and higher stellar mass, reflecting the tendency of higher BNSM rates in more massive galaxies. We introduce a formalism to efficiently make forecast on using host galaxy properties to constrain DTD models. We find comparable constraints from the dependence of BNSM occurrence distribution on galaxy colour, specific star formation rate, and stellar mass, all better than those from dependence on r-band luminosity. The tightest constraints come from using individual star formation histories of host galaxies, which reduces the uncertainties on DTD parameters by a factor of three or more. Substantially different DTD models can be differentiated with about 10 BNSM detections. To constrain DTD parameters at 10 per cent precision level requires about one hundred detections, achievable with GW observations on a decade time-scale.
Repeating behaviour of FRB 121102: periodicity, waiting times, and energy distribution
Authors: Cruces M , Spitler L G , Scholz P , Lynch R , Seymour A , Hessels J W T , Gouiffés C , Hilmarsson G H , Kramer M , Munjal S
Published: October 2020

Detections from the repeating fast radio burst FRB 121102 are clustered in time, noticeable even in the earliest repeat bursts. Recently, it was argued that the source activity is periodic, suggesting that the clustering reflected a not-yet-identified periodicity. We performed an extensive multiwavelength campaign with the Effelsberg telescope, the Green Bank telescope, and the Arecibo Observatory to shadow the Gran Telescope Canaria (optical), NuSTAR (X-ray) and INTEGRAL (γ-ray). We detected 36 bursts with Effelsberg, one with a pulse width of 39 ms, the widest burst ever detected from FRB 121102. With one burst detected during simultaneous NuSTAR observations, we place a 5σ upper limit of 5 × 1047 erg on the 3–79 keV energy of an X-ray burst counterpart. We tested the periodicity hypothesis using 165 h of Effelsberg observations and find a periodicity of 161 ± 5 d. We predict the source to be active from 2020 July 9 to October 14 and subsequently from 2020 December 17 to 2021 March 24. We compare the wait times between consecutive bursts within a single observation to Weibull and Poisson distributions. We conclude that the strong clustering was indeed a consequence of a periodic activity and show that if the few events with millisecond separation are excluded, the arrival times are Poisson distributed. We model the bursts’ cumulative energy distribution with energies from ∼1038–1039 erg and find that it is well described by a power law with slope of γ = −1.1 ± 0.2. We propose that a single power law might be a poor descriptor of the data over many orders of magnitude.
Secukinumab and ustekinumab treatment in psoriatic arthritis: results of a direct comparison
Authors: Letarouilly Jean-Guillaume , Flachaire Benoît , Labadie Céline , Kyheng Maéva , Cohen Nicolas , Sellam Jérémie , Richette Pascal , Dieude Philippe , Claudepierre Pascal , Fautrel Bruno , Houvenagel Eric , Nguyen Chi Duc , Guyot Marie-Hélène , Segaud Nicolas , Marguerie Laurent , Deprez Xavier , Salmon Jean-Hugues , Baudens Guy , Miceli-Richard Corinne , Gervais Elisabeth , Chary-Valckenaere Isabelle , Lafforgue Pierre , Philippe Peggy , Loeuille Damien , Richez Christophe , Tubach Florence , Pham Thao , Flipo René-Marc
Published: October 2020

Objectives

To evaluate the characteristics of patients (pts) with PsA treated by ustekinumab (UST) or secukinumab (SEK) and to compare real-world persistence of UST and SEK in PsA.

Methods

In this retrospective, national, multicentre cohort study, pts with PsA (CASPAR criteria or diagnosis confirmed by the rheumatologist) initiating UST or SEK with a follow-up ≥6 months were included from January 2011 to April 2019. The persistence between SEK and UST was assessed after considering the potential confounding factors by using pre-specified propensity-score methods. Causes of discontinuation and tolerance were also collected.

Results

A total of 406 pts were included: 245 with UST and 161 with SEK. The persistence rate was lower in the UST group compared with the SEK group [median persistence 9.4 vs 14.7 months; 26.4% vs 38.0% at 2 years; weighted hazard ratio (HR) = 1.42; 95% CI: 1.07, 1.92; P =0.015]. In subgroup analysis, the persistence rate of SEK associated with MTX was significantly higher than that of UST associated with MTX: HR = 2.20; 95% CI: 1.30, 3.51; P =0.001, in contrast to SEK vs UST monotherapy: HR = 1.06; 95% CI: 0.74, 1.53; P =0.75. Discontinuation due to inefficacy was reported in 91.7% (SEK) and 82.4% (UST) of pts. Discontinuation due to an adverse event was reported in 12.2% (SEK) and 7.7% (UST) of pts.

Conclusion

In this first study comparing UST and SEK, the persistence of SEK was higher than that of UST in PsA. In subgroup analysis, this difference was only found in association with MTX.
Nurse Perceptions of Babywearing for Neonates With Neonatal Abstinence Syndrome in the Neonatal Intensive Care Unit
Authors: Williams Lela Rankin , Grisham Lisa M. , Gebler-Wolfe Molly , Kelsch Karen , Bedrick Alan , Bader M. Y.
Published: October 2020

Background:

Infants diagnosed with neonatal abstinence syndrome (NAS) often spend several weeks in a neonatal intensive care unit (NICU) and have difficulty being consoled. Infant carriers may be used to help with irritability, while allowing the adult user to be more mobile, through the practice of babywearing (the facilitated holding of an infant using a soft cloth infant carrier worn on the body).

Purpose:

To examine the experience of babywearing infants diagnosed with NAS while admitted in the NICU from the perspective of the nurses who care for them.

Methods:

Nurses (N = 18; mean age = 35.44 years, SD = 9.45) were recruited and interviewed using a semistructured interview method from a 38-bed NICU in the Southwestern United States.

Results:

A thematic content analyses using an open coding scheme yielded 6 themes that fell into 2 categories: (1) benefits of babywearing infants with NAS in the NICU (Infant Consoling, Adult Multitasking, Caregiver–Infant Trust); and (2) suggestions to maximize babywearing in the NICU (Infection Control, Reoccurring Infant Carrier Education, and Reduced Patient Load).

Implications for Practice:

Many NICUs incorporate kangaroo care (or skin-to-skin contact) as a treatment option; however, NICU staff cannot participate in kangaroo care. Babywearing is a practical alternative for nurses and support staff. Nurses supported the practice of babywearing as a means to improve the well-being of infants with NAS while also allowing for increased efficiency in nursing tasks.

Implications for Research:

More prospective studies are needed that evaluate the carryover effects and long-term impact of babywearing for infants diagnosed with NAS.
Reliability of Low-dose Biplanar Radiography in Assessing Pediatric Torsional Pathology
Authors: Brooks Jaysson T. , Bomar James D. , Jeffords Megan E. , Farnsworth Christine L. , Pennock Andrew T. , Upasani Vidyadhar V.
Published: October 2020

Background:

Low-dose biplanar radiographs (LDBRs) significantly reduce ionizing radiation exposure and may be of use in evaluating lower extremity torsion in children. In this study, we evaluated how well femoral and tibial torsional profiles obtained by LDBR correspond with 3-dimensional (3D) computed tomography (CT) and magnetic resonance axial imaging (MRI) in pediatric patients with suspected rotational abnormalities.

Methods:

Patients who had both LDBR and CT/MRI studies performed for suspected lower extremity rotational deformities were included. Unlike previous publications, this study focused on patients with lower extremity torsional pathology, and bilateral lower extremities of 17 patients were included. CT/MRI torsion was measured using the Reikerås method, after conversion to 3D reconstructions. The LDBRs were deidentified and sent to the software division of EOS imaging, who created 3D reconstructions and evaluated each reconstruction for the torsional quantification of the femurs and tibiae. These imaging modalities were compared using correlation statistics and Bland-Altman analyses.

Results:

The mean age of the cohort was 12.1±1.7 years old. Torsional values of the femur were significantly lower in LDBRs versus 3D CT/MRIs at 17.7±15.1 and 23.3±17.3, respectively (P=0.001). Torsional values of the tibia were similar in LDBRs versus 3D CT/MRIs at 23.6±10.6 and 25.3±11.2, respectively (P=0.503). There was a good intermodality agreement between LDBR and 3D CT/MRI torsional values in the femur (intraclass correlation coefficient=0.807) and tibia (intraclass correlation coefficient=0.768). Bland-Altman analyses showed a fixed bias with a mean difference of −5.6±8.8 degrees between femoral torsion measurements in LDBRs versus 3D CT/MRIs (P=0.001); 15% (5/34) of femurs had a clinically significant measurement discrepancy. Fixed bias for LDBR measurements compared with 3D CT/MRIs for the tibia was not observed (P=0.193), however, 12% (4/34) of tibias had a clinically significant measurement discrepancy.

Conclusion:

Although we found strong correlations between torsional values of the femur and tibia measured from LDBRs and 3D CT/MRIs, torsional values of the femur produced from LDBRs were significantly lower than values obtained from 3D CT/MRIs with some notable outliers.

Level of Evidence:

Level III.
An Autopsy Review: “COVID Toes”
Authors: Yilmaz Mine M. , Szabolcs Matthias J. , Geskin Larisa J. , Niedt George W.
Published: October 2020

“Severe acute respiratory syndrome coronavirus‐2” (SARS‐CoV‐2) infection has variable described dermatologic manifestations. “COVID (coronavirus disease) toes” became a hallmark of the disease in young and largely asymptomatic patients, who may have negative test results for SARS‐CoV‐2. Pernio (chilblains)-like lesions are seen mostly in infected pediatric patients and are purple painful, frequently bilateral, ill‐defined plaques with prominent inflammation on histological examination. In contrast to pernio‐like presentation in children, critically ill adult patients with SARS‐CoV‐2 develop “purple” digits that may be sharply demarcated and may demonstrate asymmetric areas of ischemia. These 2 contrasting entities are sometimes grouped together as “COVID toes” due to some similarities in clinical appearance and presentation. Here, we summarize histopathologic examination from an autopsy, including the cutaneous lesions from the affected and normal contralateral toes and correlate them with systemic findings. In contrast to pernio‐like lesions, the skin of the affected necrotic toes contained thrombi in vessels without prominent inflammation, suggestive of an embolic event. This is further supported by the clinical history of and autopsy findings of popliteal artery thrombus and multiple subsegmental pulmonary emboli. Our findings suggest that critically ill patients with SARS‐CoV‐2 have different pathological processes affecting skin at peripheral sites (ie, fingers, toes, ears, and nose), which may be due to thromboembolic events. The skin is a mirror of the body and skin pathology may shed light into overall pathogenesis of systemic illness and processes.
COVID-19 and Multisystem Inflammatory Syndrome in Latin American Children
Authors: Antúnez-Montes Omar Yassef , Escamilla Maria Isabel , Figueroa-Uribe Augusto Flavio , Arteaga-Menchaca Erick , Lavariega-Saráchaga Manuel , Salcedo-Lozada Perla , Melchior Priscilla , de Oliveira Rodrigo Beréa , Tirado Caballero Juan Carlos , Redondo Hernando Pinzon , Montes Fontalvo Laura Vanessa , Hernandez Roger , Chavez Carolina , Campos Francisco , Uribe Fadia , del Aguila Olguita , Rios Aida Jorge Alberto , Buitrago Andrea Parra , Betancur Londoño Lina Maria , Mendoza Vega León Felipe , Hernández Carolina Almeida , Sali Michela , Higuita Palacio Julian Esteban , Gomez-Vargas Jessica , Yock-Corrales Adriana , Buonsenso Danilo
Published: October 2020

Background:

To date, there are no comprehensive data on pediatric COVID-19 from Latin America. This study aims to assess COVID-19 and Multisystem Inflammatory Syndrome (MIS-C) in Latin American children, to appropriately plan and allocate resources to face the pandemic on a local and international level.

Methods:

Ambispective multicenter cohort study from 5 Latin American countries. Children 18 years of age or younger with microbiologically confirmed SARS-CoV-2 infection or fulfilling MIS-C definition were included.

Findings:

Four hundred nine children were included, with a median age of 3.0 years (interquartile range 0.6–9.0). Of these, 95 (23.2%) were diagnosed with MIS-C. One hundred ninety-one (46.7%) children were admitted to hospital and 52 (12.7%) required admission to a pediatric intensive care unit. Ninety-two (22.5%) patients required oxygen support: 8 (2%) were started on continuous positive airway pressure and 29 (7%) on mechanical ventilation. Thirty-five (8.5%) patients required inotropic support. The following factors were associated with pediatric intensive care unit admission: preexisting medical condition (P < 0.0001), immunodeficiency (P = 0.01), lower respiratory tract infection (P < 0.0001), gastrointestinal symptoms (P = 0.006), radiologic changes suggestive of pneumonia and acute respiratory distress syndrome (P < 0.0001) and low socioeconomic conditions (P = 0.009).

Conclusions:

This study shows a generally more severe form of COVID-19 and a high number of MIS-C in Latin American children, compared with studies from China, Europe and North America, and support current evidence of a more severe disease in Latin/Hispanic children or in people of lower socioeconomic level. The findings highlight an urgent need for more data on COVID-19 in Latin America.
Nurse Leaders' Assumptions and Attitudes Toward Residency Programs for New Graduate Nurses
Authors: Trepanier Sylvain , Yoder-Wise Patricia S. , Church Cory D. , Africa Larissa
Published: October 2020

The Future of Nursing Report from 2010 offered key recommendations for the practice of nursing, including the need for nurse residency programs for all new graduate nurses. Although numerous articles can be found about the programs themselves, finding information about the support of nurse leaders for such programs is more challenging. In the spring of 2019, a small group of invited nurse leaders from across the United States met during a “Think Tank.” The purpose of this gathering was to discuss a policy brief offered by the American Academy of Nursing requiring all new graduate registered nurses to participate in a nurse residency program as part of their transition into practice. To determine nurse leaders' assumptions and attitudes toward nurse residency programs, the think tank planners conducted a national survey. Over 500 members of the American Organization for Nursing Leadership participated in this survey. In this article, the authors offer that nurse leaders are supportive of residency programs for new graduate nurses although some are still struggling with demonstrating the value proposition. In addition, nurse leaders are not in support of a national mandate.
Change in Intraocular Pressure and Ocular Perfusion Pressure Due to Trendelenburg Positioning
Authors: Ristin Lauren , Dougherty Wood Sarah , Sullivan-Mee Michael , Rixon Andrew , Bence Brett , Ballinger Rex
Published: October 2020

SIGNIFICANCE

This study increases foundational knowledge about the dynamic relationships between intraocular pressure (IOP), blood pressure (BP), and mean ocular perfusion pressure (MOPP) in the setting of steep Trendelenburg positioning and may inform medical decision making for patients in which this positioning is planned.

PURPOSE

The purpose of this study was to explore the demographic and clinical factors related to IOP, MOPP, and BP change during Trendelenburg positioning in a large sample of subjects.

METHODS

A single-cohort interventional study was conducted at the American Academy of Optometry 2017 annual meeting. Baseline demographic data were collected by a secure survey tool. IOP and BP were then measured while seated and again after 1 and 2 minutes in a steep Trendelenburg position. Raw and percentage differences for each variable were compared between time points, and regression analyses demonstrated factors related to change in IOP, BP, and MOPP during steep Trendelenburg positioning.

RESULTS

Median IOP increased from 16.3 mmHg (13.3 to 18.3 mmHg) at baseline to 25.0 mmHg (21.7 to 28.7 mmHg) at 1 minute after assuming the Trendelenburg position. More than 95% of individual eyes exhibited an IOP increase of at least 10%, and 45% had an IOP increase of 10 mmHg or greater. Correspondingly, MOPP fell from 50.3 mmHg (43.4 to 55.4 mmHg) at baseline to 36.3 mmHg (31.9 to 43.3 mmHg). Mean ocular perfusion pressure decreased by at least 10 in 90% of eyes. In multivariate regression analysis, factors independently related to percentage IOP increase were increasing weight, less myopic refractive error, lower baseline pulse, and lower baseline IOP (total r
2 = 0.31, P < .001). Conversely, weight was the only variable independently related to percent MOPP change, and this relationship was weak (r
2 = 0.05, P = .008).

CONCLUSIONS

Our results confirm that steep Trendelenburg positioning causes an increase in IOP and a decrease in MOPP in almost all eyes. Considering the identified causative factors will inform clinical education and provide foundational knowledge for future investigations.
Acute Brain Injury in Infant Venoarterial Extracorporeal Membrane Oxygenation: An Autopsy Study*
Authors: Caturegli Giorgio , Cho Sung-Min , White Bartholomew , Chen Liam L.
Published: October 2020

Objectives:

Characterization of the types and timing of acute brain injury in infant autopsy patients after extracorporeal membrane oxygenation.

Design:

Retrospective cohort study.

Setting:

Single tertiary-care center.

Patients:

Infants supported on extracorporeal membrane oxygenation.

Measurements and Main Results:

Clinical and pathologic records were reviewed for infant extracorporeal membrane oxygenation patients who had undergone brain autopsy in a single center between January 2009 and December 2018. Twenty-four patients supported on venoarterial extracorporeal membrane oxygenation had postmortem examination with brain autopsy. Median age at extracorporeal membrane oxygenation initiation was 82 days (interquartile range, 11–263 d), median age at time of death was 20 weeks (interquartile range, 5–44 wk), and median extracorporeal membrane oxygenation support duration was 108 hours (interquartile range, 35–366 hr). The most common acute brain injury found at autopsy was hypoxic-ischemic brain injury (58%) followed by intracranial hemorrhage (29%). The most common types of intracranial hemorrhage were intracerebral (17%), subarachnoid (17%), and subdural (8%). Only five infants (21%) did not have acute brain injury. Correlates of acute brain injury included low preextracorporeal membrane oxygenation oxygen saturation as well as elevated liver enzymes, total bilirubin, and lactate on days 1 and 3 of extracorporeal membrane oxygenation. Gestational age, Apgar scores, birth weight, extracorporeal membrane oxygenation duration, anticoagulation therapy, and renal and hepatic impairments were not associated with acute brain injury.

Conclusions:

Acute brain injury was observed in 79% of autopsies conducted in infants supported on extracorporeal membrane oxygenation. Hypoxic-ischemic brain injury was the most common type of brain injury (58%), and further associations with preextracorporeal membrane oxygenation acute brain injury require additional exploration.
Adult Cranioplasty and Perioperative Patient Safety: Does Plastic Surgery Facility Volume Matter?
Authors: Rochlin Danielle H. , Sheckter Clifford C. , Khosla Rohit K. , Lorenz Hermann Peter
Published: October 2020

Cranioplasty lies at the intersection of neurosurgery and plastic surgery, though little is known about the impact of plastic surgery involvement. The authors hypothesized that adult cranioplasty patients at higher volume plastic surgery facilities would have improved inpatient outcomes. Adult cranioplasty encounters were extracted from the National Inpatient Sample from 2012 to 2014 based on International Classification of Diseases, Ninth Revision (ICD-9) codes. Regression models included the following variables: age, gender, race/ethnicity, Elixhauser Comorbidity Index, payer, hospital size, region, and urban/teaching status. Outcomes included odds of receiving a flap, perioperative patient safety indicators, and mortality. The weighted sample included 49,305 encounters with diagnoses of neoplasm (31.2%), trauma (56.4%), infection (5.2%), a combination of these diagnoses (3.9%), or other diagnoses (3.2%). There were 1375 inpatient mortalities, of which 10 (0.7%) underwent a flap procedure. On multivariable regression, higher volume plastic surgery facilities and all diagnoses except uncertain neoplasm were associated with an increased likelihood of a flap procedure during the admission for cranioplasty, using benign neoplasm as a reference (P < 0.001). Plastic surgery facility volume was not significantly associated with likelihood of a patient safety indicator event. The highest volume plastic surgery quartile was associated with lower likelihood of inpatient mortality (P = 0.008). These findings support plastic surgery involvement in adult cranioplasty and suggest that these patients are best served at high volume plastic surgery facilities.
Ablepharon Macrostomia Syndrome: Rib Cartilage and Fat Grafting for Lower Lid Reconstruction
Authors: Kurnik Nicole M. , Leach Garrison A. , Singh Davinder J. , Mansueto Lisa A.
Published: October 2020

Ablepharon macrostomia syndrome (AMS) is a rare condition with fewer than 20 cases being reported in the literature. Features of AMS include ablepharon, hypertelorism, macrostomia, dysplastic ears, sparse body hair, and ambiguous genitalia. The most significant phenotypic presentation is rudimentary eyelids resulting in exposure keratopathy, corneal abrasions, and potential blindness. Numerous methods including primary full thickness skin grafting, conjunctival sutures followed by full thickness skin grafting, and a combination of skin grafting and local flaps have been described for definitive eyelid reconstruction in these patients. The authors report the first case of autologous rib cartilage grafting and fat grafting for lower eyelid reconstruction in a patient with AMS.
Endoskeletal mineralization in chimaera and a comparative guide to tessellated cartilage in chondrichthyan fishes (sharks, rays and chimaera)
Authors: Seidel Ronald , Blumer Michael , Chaumel Júlia , Amini Shahrouz , Dean Mason N.
Published: October 2020

An accepted uniting character of modern cartilaginous fishes (sharks, rays, chimaera) is the presence of a mineralized, skeletal crust, tiled by numerous minute plates called tesserae. Tesserae have, however, never been demonstrated in modern chimaera and it is debated whether the skeleton mineralizes at all. We show for the first time that tessellated cartilage was not lost in chimaera, as has been previously postulated, and is in many ways similar to that of sharks and rays. Tesserae inChimaera monstrosaare less regular in shape and size in comparison to the general scheme of polygonal tesserae in sharks and rays, yet share several features with them. For example,Chimaeratesserae, like those of elasmobranchs, possess both intertesseral joints (unmineralized regions, where fibrous tissue links adjacent tesserae) and recurring patterns of local mineral density variation (e.g. Liesegang lines, hypermineralized ‘spokes’), reflecting periodic accretion of mineral at tesseral edges as tesserae grow.Chimaera monstrosa's tesserae, however, appear to lack the internal cell networks that characterize tesserae in elasmobranchs, indicating fundamental differences among chondrichthyan groups in how calcification is controlled. By compiling and comparing recent ultrastructure data on tesserae, we also provide a synthesized, up-to-date and comparative glossary on tessellated cartilage, as well as a perspective on the current state of research into the topic, offering benchmark context for future research into modern and extinct vertebrate skeletal tissues.
Should international borders re-open? The impact of travel restrictions on COVID-19 importation risk
Authors: Liebig Jessica , Najeebullah Kamran , Jurdak Raja , Shoghri Ahmad El , Paini Dean
Published: October 2020

Novel coronavirus disease (COVID-19) has spread across the world at an unprecedented pace, reaching over 200 countries and territories in less than three months. In response, many governments denied entry to travellers arriving from various countries affected by the virus. While several industries continue to experience economic losses due to the imposed interventions, it is unclear whether the different travel restrictions were successful in reducing COVID-19 importations. Here we develop a comprehensive framework to model daily COVID-19 importations, considering different travel bans. We quantify the temporal effects of the restrictions and elucidate the relationship between incidence rates in other countries, travel flows and the expected number of importations into the country under investigation. As a cases study, we evaluate the travel bans enforced by the Australian government. We find that international travel bans in Australia lowered COVID-19 importations by 87.68% (83.39 - 91.35) between January and June 2020. The presented framework can further be used to gain insights into how many importations to expect should borders re-open. Authorities may consider the presented information when planning a phased re-opening of international borders.
Identification of a peroxidase inhibitor that enhances kanamycin activity
Authors: Hui Zhen , Liu Shiyi , Cui Ruiqin , Zhou Biao , Hu Chunxia , Zhang Min , Deng Qiuyang , Cheng Shumin , Luo Yutian , Chen Huaisheng , Wu Jinsong , Lu Yuemei , Liu Xueyan , Dai Lingyun , Huang Wei
Published: October 2020

Background

The threat of antimicrobial resistance calls for more efforts in basic science, drug discovery, and clinical development, particularly gram-negative carbapenem-resistant pathogens.

Objectives and methods

Whole-cell–based screening was performed to identify novel antibacterial agents againstAcinetobacter baumanniiATCC19606. Spontaneously resistant mutant selection, whole-genome sequencing, and surface plasmon resonance were used for target identification and confirmation. Checkerboard titration assay was used for drug combination analysis.

Results

A small molecule named 6D1 with the chemical structure of 6-fluorobenzo[d]isothiazol-3(2H)-one was identified and exhibited activity againstA. baumanniiATCC19606 strain (minimal inhibitory concentration, MIC = 1 mg/L). The mutation in the plasmid-derivedohrBgene that encodes a peroxidase was identified in spontaneously resistant mutants. Treatment of the bacteria with 6D1 resulted in increased sensitivity to peroxide such astert-butyl hydroperoxide. The binding of 6D1 and OhrB was confirmed by surface plasmon resonance. Interestingly, the MIC of kanamycin against spontaneously resistant mutants decreased. Finally, we identified the effect of 6D1 on enhancing the antibacterial activity of kanamycin, including New Delhi metallo-β-lactamase (NDM-1)-producing carbapenem-resistantKlebsiella pneumoniae, but not in strains carrying kanamycin resistance genes.

Conclusions

In this study, we identified a peroxidase inhibitor that suppresses the growth ofA. baumanniiand enhances the antibacterial activity of kanamycin. We propose that peroxidase may be potentially used as a target for kanamycin adjuvant development.
Variability in Coronavirus Disease-2019 Case, Death, and Testing Rates in the United States and Worldwide
Authors: Schaefer Ernst J. , Geller Andrew S. , Dulipsingh Latha , Diffenderfer Margaret R. , Wisotzkey Jeffrey , Kleiboeker Steven B.
Published: October 2020

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection has been associated with a worldwide pandemic. We assessed data as of November 25, 2020 from our combined laboratories and as reported for states in the United States (US) and countries for case, death, and testing rates per million to determine causes of rate differences. SARS-CoV-2 naso-pharyngeal (NP) RNA testing in 1,179,912 subjects in 47 states (39 of which with >100 cases) are reported, with a mean 9.3% positive rate, comparable to the 7.0% rate reported nationwide. In 91 previously positive (2-4 weeks) subjects, NP swab testing was twice as likely to be positive (58.6%) as saliva samples (21.5%). We also documented that NP swabs could remain positive for 6 weeks or longer. Our positive rates per state agreed reasonably well with reported national data (r=0.609, P<0.0001). The highest US case rates per million were in the mid-west; the highest death and testing rates were in the northeast. Of 47 countries, the highest case, death, and testing rates per million were mainly in Europe and the Americas, with the lowest rates in Asia. Correlations between case and death rates and case and testing rates were very different between states (0.076 and -0.093, respectively) and countries (0.763 and 0.600, respectively). In conclusion, outpatient saliva testing was not as sensitive as NP testing for detection, and the marked variability in case and death rates was most likely due to differences in public health measures, viral and human genetic differences and age of cases, rather than due to differences in testing rates.
Preliminary evidence for upward elevational range shifts by Eastern Himalayan birds
Authors: Girish Krishna S. , Srinivasan Umesh
Published: October 2020

The ongoing climate crisis is one of the most significant threats to biodiversity globally. As the Earth warms, species have adapted by shifting their geographical ranges either polewards, or in mountainous regions, upslope towards higher elevations, presumably to continue to inhabit a suitable thermal environment. Upslope range shifts are of particular concern in tropical mountain ranges because: (a) tropical species are particularly thermally sensitive, (b) as species move upwards, they can run out of habitable space, leading to local extirpations, and (c) tropical mountains harbour a disproportionately high fraction of the planet’s terrestrial biodiversity – rapid upslope range shifts can therefore result in significant biodiversity losses. We used citizen science data over a 13-year period to evaluate whether 39 eastern Himalayan bird species might be shifting to higher elevations over time, by analyzing changes in the frequency of reporting of these species at birdwatching hotspots. For these species, we find evidence consistent with upslope range shifts, with species with the bulk of their elevational ranges below the hotspot elevation showing increases in their reporting frequency over time, and those with most of their elevational ranges above the hotspot elevation declining in reporting frequency. Our findings are suggestive of rapid responses to climate change by eastern Himalayan birds. We caution that eastern Himalayan bird species might be at special risk from increasing global temperatures because of their heightened thermal sensitivity coupled with particularly high rates of warming in the region. Eastern Himalayan birds are likely to require large tracts of undisturbed natural habitat across entire elevational gradients to be able to track changing temperatures by moving to higher elevations to remain resilient to climate change.

One of the most fundamental responses of species to changing temperatures is to change their geographic ranges, possibly to track the range of temperatures that is ideal for their survival.

With increasing climate warming, this shift could happen by moving towards the poles or in mountainous areas, towards the summit.

Due to the high thermal sensitivity of tropical species and the decrease in space as species move up mountains, the extremely biodiverse bird communities of tropical mountains are particularly vulnerable.

Using citizen science data from birding hotspots along an elevational gradient in the Eastern Himalayas over a 13-year period, we measured the change in reporting frequency of 39 common bird species.

Changes in reporting frequency are generally consistent with the fact that upslope shifts are taking place in the Eastern Himalayas, similar to results for birds from other tropical mountains.
Structural impact on SARS-CoV-2 spike protein by D614G substitution
Authors: Zhang Jun , Cai Yongfei , Xiao Tianshu , Lu Jianming , Peng Hanqin , Sterling Sarah M. , Walsh Richard M. , Rits-Volloch Sophia , Sliz Piotr , Chen Bing
Published: October 2020

Substitution for aspartic acid by glycine at position 614 in the spike (S) protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of the ongoing pandemic, appears to facilitate rapid viral spread. The G614 variant has now replaced the D614-carrying virus as the dominant circulating strain. We report here cryo-EM structures of a full-length S trimer carrying G614, which adopts three distinct prefusion conformations differing primarily by the position of one receptor-binding domain (RBD). A loop disordered in the D614 S trimer wedges between domains within a protomer in the G614 spike. This added interaction appears to prevent premature dissociation of the G614 trimer, effectively increasing the number of functional spikes and enhancing infectivity. The loop transition may also modulate structural rearrangements of S protein required for membrane fusion. These findings extend our understanding of viral entry and suggest an improved immunogen for vaccine development.
Establishment and characterization of fibroblast cultures derived from a female common hippopotamus (Hippopotamus amphibius) skin biopsy
Authors: Wang Tao , Li Zelong , Wei Jinpu , Zheng Dongmin , Wang Chen , Xu Chang , Chen Wu , Wang Bo
Published: October 2020

The population decline in the common hippopotamus (Hippopotamus amphibius) has necessitated the preservation of their genetic resources for species conservation and research. Of all actions, cryopreservation of fibroblast cell cultures derived from animal biopsy is considered a simple but efficient means. Nevertheless, preserving viable cell cultures of the common hippopotamus has not been achieved to our knowledge. To this end, we detailed a method to establish fibroblast cell cultures from a female common hippopotamus fetus in this study. By combining the classic tissue explant direct culture and enzymatic digestion methods, we isolated a great number of cells with typical fibroblastic morphology and high viability. Characterization of the fibroblast cultures was carried out using different techniques. In short, neither bacteria/fungi nor mycoplasma was detectable in the cell cultures throughout the study. The population doubling time was 23.9 h according to the growth curve. Karyotyping based on Giemsa staining showed that cultured cells were diploid with 36 chromosomes in all, one pair of which was sex chromosomes. Mitochondrial cytochrome C oxidase subunit I gene sequence of the cultured cells was 99.26% identical with theHippopotamus amphibiuscomplete mitochondrial DNA sequence registered in GenBank, confirming the cells were derived from a common hippopotamus. Flow cytometry and immunofluorescence staining results revealed that the detected cells were positive for fibroblast markers, S100A4 and Vimentin. In conclusion, we isolated and characterized a new fibroblast cell culture from a common hippopotamus skin sample and the cryopreserved cells could be useful genetic materials for the future research.
Financial development and economic growth in SADC countries: a panel study
Authors: Moyo Clement , Le Roux Pierre
Published: October 2020

Purpose

The impact of financial development on economic growth has received considerable attention since the 2008/2009 global financial crisis. High levels of credit to the private sector were partly to blame for the crisis, and this has re-ignited the debate on whether the growth-enhancing effects of financial development outweigh the retarding effects associated with financial crises. This paper therefore examines the financial development–growth nexus in SADC countries during the period 1990–2015.

Design/methodology/approach

The empirical analysis is conducted using the pooled mean group estimator. Furthermore, financial development indices are created due to the strong correlations between the individual financial development indicators using principal component analysis.

Findings

The results show that financial development, captured by the indices or the individual financial development indicators, has a negative impact on economic growth in the long term.

Research limitations/implications

Due to the unavailability of data, the study only focussed on banking sector development. The researcher would have preferred to incorporate stock market development.

Practical implications

Due to financial vulnerabilities emanating from an inadequate monitoring and supervisory framework, further enhancement of financial development should be undertaken with caution in SADC countries. Therefore, institutional quality should be enhanced in order for SADC countries to benefit from the development of the financial sector.

Originality/value

Most studies investigating the financial development–growth nexus in SADC countries utilise the individual measures of financial development which often produce contradicting results. This study constructs financial development indices to capture the impact of various banking sector development indicators on growth.
Does size of construction firms matter? Impact of project-factors and organization-factors on project performance
Authors: Sekar Gopal , Sambasivan Murali , Viswanathan Kuperan
Published: October 2020

Purpose

The purpose of this study is to analyze and compare the impact of project-factors and organization-factors on five indicators of project performance for small and medium enterprise (SME) and large construction contracting firms that are fully responsible for the successful completion of the projects. The five performance indicators are time, cost, safety, quality and financial.

Design/methodology/approach

A questionnaire survey was conducted to solicit responses from project managers/directors from 342 construction firms in Malaysia. The construction firms included in this study came from various sectors: civil, building and infrastructure; oil and gas; marine and multidiscipline. Hierarchical multiple-regression was used to analyze the data.

Findings

The salient findings are as follows: (1) impacts of project-factors and organization-factors on performance indicators are different for SMEs and large construction firms and (2) relative impact of organization-factors on performance is much higher than the project-factors.

Originality/value

Analyzing the relative impact of project- and organization-factors on the performance of SMEs and large construction firms can significantly enhance the body of knowledge about performance levels and boost best practices in this respect related to construction industry.
How to achieve greater comparability-suggested ways to improve the determination of treatment gap and treatment lag
Authors: Schaub Michael Patrick
Published: October 2020

Purpose

The aim of this paper is to reveal these problems and to derive recommendations for improvement. In the field of alcohol use disorders (AUDs), two common complaints are the large treatment gap that exists because only a small percentage of people with an AUD are in treatment; and the prolonged lag that typically exists between the emergence of problematic symptoms and actual on set of treatment. However, there also are no clear definitions for these terms – “treatment gap” and “treatment lag” – and, therefore, no consensus regarding how to quantify them. For this reason, it is difficult to compare the results of studies assessing either of these measures.

Design/methodology/approach

A non-systematic literature search and logical-analytical investigation was performed of immanent problems related to definitions and measurements aiming to enhance understanding in this area and derive suggestions for improvement.

Findings

The following four fundamental questions were identified: How does one operationalise the need to change substance use behaviours? Which interventions can justifiably be called treatment? Is treatment always necessary? and How regularly do patients need to be in contact with a treatment system to be considered “in treatment”? Potential approaches to answering these questions are discussed and recommendations made for future studies to determine how the treatment gap and treatment lag should be derived.

Originality/value

The derived recommendations should make the calculation of treatment gap and treatment lag more transparent and comparable between studies. They also may serve as checklists for future studies on the treatment gap and lag in the AUD field.
A Monte Carlo evaluation of non-parametric estimators of expected shortfall
Authors: Mehlitz Julia S. , Auer Benjamin R.
Published: October 2020

Purpose

Motivated by the growing importance of the expected shortfall in banking and finance, this study aims to compare the performance of popular non-parametric estimators of the expected shortfall (i.e. different variants of historical, outlier-adjusted and kernel methods) to each other, selected parametric benchmarks and estimates based on the idea of forecast combination.

Design/methodology/approach

Within a multidimensional simulation setup (spanned by different distributional settings, sample sizes and confidence levels), the authors rank the estimators based on classic error measures, as well as an innovative performance profile technique, which the authors adapt from the mathematical programming literature.

Findings

The rich set of results supports academics and practitioners in the search for an answer to the question of which estimators are preferable under which circumstances. This is because no estimator or combination of estimators ranks first in all considered settings.

Originality/value

To the best of their knowledge, the authors are the first to provide a structured simulation-based comparison of non-parametric expected shortfall estimators, study the effects of estimator averaging and apply the mentioned profiling technique in risk management.