bluuebunny/crossref_metadata_2025 huggingface dataset:
Imagery and How it Works in Lorca’s Poeta en Nueva York: The Case of ‘1910 (Intermedio)’
Authors: Anderson Andrew A
Published: December 2020

The terms ‘image’ and ‘imagery’ have changed their meanings over time and are employed very inconsistently by commentators. In the early decades of the twentieth century, Marinetti, Pound, Eliot, Reverdy and Breton, among others, weighed in with innovative proposals of their own with respect to what an image was and how it worked. Lorca’s thinking on the subject of metaphor, image and what he called the ‘hecho poético’ evolved too, with analogies to be made between the latter concept and theories of Jean Epstein and Eliot. The variety of critical opinions concerning Poeta en Nueva York mandates careful scrutiny of individual texts, and a stylistic analysis of ‘1910 (Intermedio)’ reveals a mixture of more conventional and more modern imagistic techniques, the most prominent of which align quite closely with Eliot’s notion of the ‘objective correlative’ – in his words ‘a set of objects, a situation, a chain of events which shall be the formula’ of a particular emotion. This finding adds weight to the argument against Surrealism as a dominant factor in the stylistic orientation of many of the poems in the collection.
Should I Do This? Factors Influencing the Decision to Raise Grandchildren Among Custodial Grandparents
Authors: Hayslip Bert , Fruhauf Christine A , Fish Joshua
Published: December 2020

Background and Objectives

Grandparents often step in to raise grandchildren when the middle generation is unavailable or unwilling. Although the consequences of raising grandchildren are well researched, little is known about the factors influencing grandparents’ decisions to raise grandchildren. The objectives of this study were to (a) explore the factors that influence decision-making processes among grandparent caregivers, and (b) investigate the extent to which these factors reflect a multifaceted, dualistic framework.

Research Design and Methods

Data were collected from 108 custodial grandparents who answered an open-ended question about their decision to raise grandchildren.

Results

Content analyses of participants’ answers yielded 15 factorial dimensions defined in terms of their negative/push or positive/pull poles, as it related to their decision to raise grandchildren. Chi-squared tests were used to examine each dimension to the extent to which elicited frequencies were differentially represented for positive versus negative poles. For 12 dimensions, the negative decisional parameters outweighed those that were positive.

Discussion and Implications

Grandparents report both positive and negative parameters when reflecting on their decision to raise grandchildren. These results call for further research to advance the understanding of the decision-making processes that caregiving grandparents make and the role that they may have on their experiences.
Interannual variations of degree 2 from geodetic observations and surface processes
Authors: Rosat S , Gillet N , Boy J-P , Couhert A , Dumberry M
Published: December 2020

Geodetic observations from space continuously record surface deformation and global mass redistribution with an increasing accuracy. In parallel, surficial processes (oceanic, atmospheric, and hydrological loading) are more and more precisely modeled.We propose a confrontation of the geodetic Global Positioning System (GPS) and gravity-field satellite laser ranging (SLR) observations at decadal and interannual time scales, in terms of resolution, correlation and comparison with surficial loading models. We focus on the largest global scale signals of degree 2. At interannual periods, surface deformations retrieved from GPS time-series do not exceed 0.8 mm. Our analysis does not reveal the presence of a dominant signal at a specific period, except perhaps for a signal of approximately 3 yr likely connected to the loading response to El Nio / Southern Oscillations. Contrary to the results of previous studies, we do not find in GPS time-series a clear 6-yr oscillation associated with a degree-2 order-2 pattern. Interannual variations in the degree-2 Stokes coefficients of the gravity field do not exceed 2 × 10−11. We do not detect a dominant gravity signal at one specific period but instead a broad spectrum of frequencies. The comparison between the degree 2 deformations built from GPS time-series with a prediction from SLR derived gravity variations reveals some correlations, though their differences remain important. This highlights the present day limitations of these techniques in their ability to characterize global scale interannual variations. Hydrological loading models show some correlations with both GPS and SLR signals, but we cannot firmly establish that continental hydrology is dominantly responsible for the observed variations. Given the current limits in the resolution of both gravity and surface deformation and in the modelling of surface processes, we conclude that it will be a challenge to retrieve a geodetic signal of sub-decadal period originating in the Earth’s core.
Essentially Derived Varieties in View of New Breeding Technologies – Plant Breeders’ Rights at a Crossroads
Authors: Kock Michael A
Published: December 2020

Plant breeders’ rights (PBR) within the framework of the International Convention for the Protection of New Varieties of Plants (UPOV) are the sui generis intellectual property (IP) system of choice for plant varieties. It achieves a balance between the protection of new varieties and access to protected breeding material for further improvement. The extension of the protection to essentially derived varieties (EDVs) in the UPOV 1991 Convention1 was controversial from the beginning as it creates a tension with the breeders’ exemption. The 2017 UPOV Explanatory Notes on EDVs further fueled the debate as they were seen to limit the EDV extension, while some argue that the EDV scope should extend to all predominantly derived varieties merely on the basis of genetic conformity. With the rise of new breeding technologies (NBTs), legal certainty on the EDV definition is of fundamental importance to avoid a chilling effect on these promising technologies. Not only would a broad EDV definition block critical innovation and restrict the full potential of NBTs to a few multinational companies,2 it would also substantially limit the scope of protection of NBT-derived varieties, as an EDV itself is not entitled to the EDV extension: Valuable NBT-derived varieties would become easy prey for plagiarism. This article shows that the legislative intent of the EDV provision does not limit innovative breeding to conventional crossing and that there is no basis for extending EDV protection to new, innovative varieties which do not retain the essential characteristics of the initial variety (IV) even if there is a high genetic conformity. By analogy with the doctrine of equivalents under the patent system, a derived variety cannot qualify as an EDV if it (i) does not retain all the essential characteristic of the IV and (ii) is ‘non-obvious’ and causes a ‘significant technical progress of considerable economic interest’. The article finally suggests guidelines and processes to overcome the current EDV dilemma.
‘A natural passion?’ The 1810 reflections of a Yorkshire farmer on homosexuality*
Authors: O’Keeffe Eamonn
Published: December 2020

In a newly discovered passage from an 1810 diary, Yorkshire tenant farmer Matthew Tomlinson considers the notion that homosexual desire is a natural, divinely ordained human tendency, discernible from adolescence and undeserving of capital punishment. Although ultimately inconclusive, his reflections offer tantalizing evidence that historical attitudes towards same-sex love in early nineteenth-century British society could be more diverse and sympathetic than previously assumed. This article contextualizes Tomlinson’s comments by considering his broader views on religion and sexuality alongside other contemporary or near-contemporary iterations of the argument that same-sex attraction is innate and blameless.
Association of Anti-TNF Therapy With Increased Risk of Acute Cholangitis in Patients With Primary Sclerosing Cholangitis
Authors: Kulkarni Chiraag , Murag Soumya , Cholankeril George , Fardeen Touran , Mannalithara Ajitha , Lerrigo Robert , Kamal Ahmad , Ahmed Aijaz , Goel Aparna , Sinha Sidhartha R
Published: December 2020

Background

Patients with primary sclerosing cholangitis (PSC) are at increased risk of developing acute cholangitis. The majority of patients with PSC have comorbid inflammatory bowel disease, and many take immunosuppressive medications. The epidemiological risks for the development of acute cholangitis in patients with PSC, including the impact of immunosuppressive therapy, are unknown.

Methods

We conducted a 2-center, retrospective cohort study using data from 228 patients at Stanford University Medical Center and Santa Clara Valley Medical Center (CA), a county health care system. Patient demographics, medications, PSC disease severity, and inflammatory bowel disease status were extracted. Using stepwise variable selection, we included demographic and covariate predictors in the multiple logistic regression model assessing risk factors for cholangitis. Time-to-event analysis was performed to evaluate specific immunosuppressive medications and development of cholangitis.

Results

Thirty-one percent of patients had at least 1 episode of acute cholangitis (n = 72). Anti-tumor necrosis factor (TNF) therapy was associated with increased odds of acute cholangitis (odds ratio, 7.29; 95% confidence interval, 2.63-12.43), but immunomodulator use was protective against acute cholangitis (odds ratio, 0.23; 95% confidence interval, 0.05-0.76). Anti-TNF therapy was associated with decreased time-to-cholangitis, with a median time of 28.4 months; in contrast, only 11.1% of patients who were prescribed immunomodulators developed cholangitis over the same time period (P < 0.001).

Conclusions

Our observations suggest that classes of immunosuppressive medications differentially modify the odds of acute cholangitis. Biologic therapy, ie, anti-TNF therapy, was shown to have significantly higher odds for patients developing acute cholangitis whereas immunomodulator therapy was shown to have a potential protective effect. These findings may help guide physicians in decision-making for determining appropriate immunosuppressive therapy.
Distinguishing Amnestic Mild Cognitive Impairment From HIV-Associated Neurocognitive Disorders
Authors: Sundermann Erin E , Bondi Mark W , Campbell Laura M , Gouaux Ben , Moore Raeanne C , Soontornniyomkij Virawudh , Moore David J
Published: December 2020

Background

Memory impairment occurs in human immunodeficiency virus (HIV)-associated neurocognitive disorders (HAND) and amnestic mild cognitive impairment (aMCI), the precursor to Alzheimer disease (AD). Methods are needed to distinguish aMCI-associated from HAND-associated impairment in people with HIV (PWH). We developed a neuropsychological method of identifying aMCI in PWH and tested this by relating AD neuropathology (β-amyloid, phospho-Tau) to aMCI versus HAND classification.

Methods

Seventy-four HIV-positive cases (aged 50−68 years) from the National NeuroAIDS Tissue Consortium had neurocognitive data within 1 year of death and data on β-amyloid and phospho-Tau pathology in frontal brain tissue. High aMCI risk was defined as impairment (<1.0 SD below normative mean) on 2 of 4 delayed recall or recognition outcomes from a verbal and nonverbal memory test (at least 1 recognition impairment required). Differences in β-amyloid and phospho-Tau by aMCI and HAND classification were examined.

Results

High aMCI risk was more common in HAND (69.0%) versus no HAND (37.5%) group. β-amyloid pathology was 4.75 times more likely in high versus low aMCI risk group. Phospho-Tau pathology did not differ between aMCI groups. Neither neuropathological feature differed by HAND status.

Conclusions

Amnestic mild cognitive impairment criteria that include recognition impairment may help to detect AD-like cognitive/biomarker profiles among PWH.
Influence of feeding thermally peroxidized lipids on growth performance, lipid digestibility, and oxidative status in nursery pigs
Authors: Kerr Brian J , Lindblom Stephanie C , Zhao Junmei , Faris Richard J
Published: December 2020

Three experiments were conducted to evaluate oil source and peroxidation status (experiment 1) or peroxidized soybean oil (SO; experiments 2 and 3) on growth performance, oxidative stress, and digestibility of dietary ether extract (EE). In experiment 1, palm oil (PO), poultry fat (PF), canola oil (CO), and SO were evaluated, while in experiments 2 and 3, only SO was evaluated. Lipids were either an unheated control (CNT) or thermally processed at 90 °C for 72 hr, being added at 10%, 7.5%, or 3% of the diet in experiments 1, 2, and 3, respectively. In experiment 1, 288 pigs (body weight, BW, 6.1 kg) were fed 1 of 8 factorially arranged treatments with the first factor being lipid source (PO, PF, CO, and SO) and the second factor being peroxidation status (CNT or peroxidized). In experiment 2, 216 pigs (BW 5.8 kg) were fed 1 of 6 treatments consisting of 100%, 90%, 80%, 60%, 20%, and 0% CNT SO blended with 0%, 10%, 20%, 40%, 80%, and 100% peroxidized SO, respectively. In experiment 3, 72 pigs (BW 5.8 kg) were fed either CNT or peroxidized SO. Pigs were fed 21 d with feces collected on day 12 or 14 and pigs bled on day 12 blood collection. In experiment 1, an interaction between oil source and peroxidation status was observed for averaged daily gain (ADG) and average daily feed intake (ADFI; P = 0.10) which was due to no impact of feeding pigs peroxidized PO, PF, or SO on ADG or ADFI compared with feeding pigs CNT PO, PF, or SO, respectively; while pigs fed peroxidized CO resulted in reduced ADG and ADFI compared with pigs fed CNT CO. There was no interaction between oil source and peroxidation status, and no lipid source effect on gain to feed ratio (GF; P ≥ 0.84), but pigs fed the peroxidized lipids had a lower GF compared with pigs fed the CNT lipids (P = 0.09). In experiment 2, feeding pigs diets containing increasing levels of peroxidized SO resulted in reduced ADG (quadratic, P = 0.03), ADFI (linear, P = 0.01), and GF (quadratic, P = 0.01). In experiment 3, feeding peroxidized SO at 3% of the diet reduced ADG (P = 0.11) and ADFI (P = 0.13), with no observed change in GF (P = 0.62). Differences in plasma protein carbonyls, glutathione peroxidase, and vitamin E due to feeding peroxidized lipids were inconsistent across the 3 experiments. Digestibility of dietary EE was reduced in pigs fed peroxidized PO or SO (P = 0.01, experiment 1) and peroxidized SO in experiments 2 and 3 (P ≤ 0.02). In conclusion, the peroxidation status of dietary lipids consistently affects growth performance and EE digestibility but has a variable effect on measures of oxidative stress.
The Descriptive Epidemiology and Outcomes of Hospitalized Burn Patients in Southern Turkey: Age-Specific Mortality Patterns
Authors: Gurbuz Kayhan , Demir Mete
Published: December 2020

The current descriptive analysis was designed to document the common epidemiologic characteristics and outcomes of burn injuries, and age-specific mortality patterns covering all age groups admitted for treatment to the Burn Center of Adana City Training and Research Hospital. Medical records were retrospectively analyzed. The patients were stratified into two age groups as pediatric and adults, and then into 10 sub-age groups. Among the 946 patients of the study population, there were 24 mortalities with a mortality rate of 2.5%. Patients within the age range of 70 to 79 years had the highest mortality rate of 33.3%; followed by 60 to 69, 80+, 18 to 29, 10 to 17, and <5 sub-age groups, whose mortality rates were 13.0%, 7.8%, 7.2%, 2.4%, and 0.5%, respectively. In terms of multivariate regression analysis of factors predicting mortality among burn patients in all age groups, fire-flame related burns, age ≥18 years, TBSA burned ≥20% (TBSA ≥20%), the existence of inhalation injury, deep partially/full-thickness burns were found to be significant prognostic factors of mortality. The strongest association was seen in TBSA ≥60% segment (P < .0001), which had 25.9 times more death risk. As expected, a similar trend was detected when the age groups stratified into age groups, and the strongest association was in the 60+ sub-age group (P < .0001), whose had 5.84 times more likely death; followed by 29 to 59 and 18 to 29 sub-age groups, with the odds ratios of 2.12 (95% confidence interval = 1.25–3.61) and 2.08 (95% confidence interval = 1.90–4.05), respectively. Oppose to these findings; the 0 to 17 sub-age group was not found to have a statistically significant effect in predicting mortality.
Navigating the Regulatory Pathways and Requirements for Tissue-Engineered Products in the Treatment of Burns in the United States
Authors: Belsky Kimberly , Smiell Janice
Published: December 2020

In the burn treatment landscape, a variety of skin substitutes, human tissue-sourced products, and other products are being developed based on tissue engineering (ie, the combination of scaffolds, cells, and biologically active molecules into functional tissue with the goal of restoring, maintaining, or improving damaged tissue or whole organs) to provide dermal replacement, prevent infection, or prevent or mitigate scarring. Skin substitutes can have a variety of compositions (cellular vs acellular), origins (human, animal, or synthetically derived), and complexities (dermal or epidermal only vs composite). The regulation of tissue-engineered products in the United States occurs by one of several pathways established by the U.S. Food and Drug Administration, including a Biologics License Application (BLA), a 510(k) (Class I and Class II devices), Premarket Approval (Class III devices), or a human cells, tissues, and cellular and tissue-based products designation. Key differentiators among these regulatory classifications include the amount and type of data required to support a filing. For example, a BLA requires a clinical trial(s) and evaluation of safety and efficacy by the Center for Biologics Evaluation and Research. Applicable approved biological products must also comply with submission of advertising and promotional materials per regulations. This review provides a description of, and associated requirements for, the various regulatory pathways for the approval or clearance of tissue-engineered products. Some of the regulatory challenges for commercialization of such products for the treatment of burns will be explored.
Competitive Harm Crossing Borders: Regulatory Gaps And A Way Forward
Authors: Martyniszyn Marek
Published: December 2020

This article analyses the current regulatory framework governing transnational restrictive business practices. It identifies key gaps that provide room for anticompetitive practices to flourish, causing cross-border transfer of wealth, typically from less affluent states. The economic harm caused by cross-border anticompetitive conduct is significant; international cartels alone caused overcharges exceeding $1.5 trillion in the period 1990–2016. This article offers a series of pragmatic policy recommendations that could narrow existing regulatory gaps. The proposals require no international negotiations and can be implemented domestically. They call for enabling of more assertive and robust extraterritorial enforcement of domestic competition laws and facilitation of positive externalities in that context.
Severe Acute Respiratory Syndrome Coronavirus-2 Pneumonia in a Newborn Treated With Remdesivir and Coronavirus Disease 2019 Convalescent Plasma
Authors: Hopwood Andrew J , Jordan-Villegas Alejandro , Gutierrez Liliana D , Cowart Mallory C , Vega-Montalvo Wilfredo , Cheung Wang Leung , McMahan Michael J , Gomez Michael R , Laham Federico R
Published: December 2020

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is a novel pandemic virus. Mounting evidence supports the possibility of vertical transmission, which at the present time appears to be rare. We report a newborn with vertically acquired SARS-CoV-2 who developed acute respiratory failure and received remdesivir and coronavirus disease 2019 convalescent plasma.
Dosimetric feasibility of computed tomography-based image-guided brachytherapy in locally advanced cervical cancer: a Japanese prospective multi-institutional study
Authors: Otani Yuki , Ohno Tatsuya , Ando Ken , Murata Kazutoshi , Kato Shingo , Noda Shin-ei , Murofushi Keiko , Ushijima Hiroki , Yoshida Daisaku , Okonogi Noriyuki , Isohashi Fumiaki , Wakatsuki Masaru , Nakano Takashi
Published: December 2020

The aim of this study was to assess the feasibility of planning dose–volume histogram (DVH) parameters in computed tomography-based 3D image-guided brachytherapy for locally advanced cervical cancer. In a prospective multi-institutional study, 60 patients with stage IIA2–IVA cervical cancer from eight institutions were treated with external beam radiotherapy using central shielding and intracavitary or hybrid (combined intracavitary/interstitial) brachytherapy (HBT). The dose constraints were set as a cumulative linear quadratic equivalent dose (EQD2) of at least 60 Gy for high-risk clinical target volume (HR-CTV) D90, D2cc ≤ 75 Gy for rectum, D2cc ≤ 90 Gy for bladder and D2cc ≤ 75 Gy for sigmoid. The median HR-CTV D90 was 70.0 Gy (range, 62.8–83.7 Gy) in EQD2. The median D2cc of rectum, bladder and sigmoid was 57.1 Gy (range, 39.8–72.1 Gy), 68.9 Gy (range, 46.5–84.9 Gy) and 57.2 Gy (range, 39.2–71.2 Gy) in EQD2, respectively. In 76 of 233 sessions (33%), 23 patients underwent HBT, and the median number of interstitial needles was 2 (range, 1–5). HBT for a bulky HR-CTV (≥40 cm3) significantly improved the HR-CTV D90 compared with intracavitary brachytherapy alone (P = 0.010). All patients fulfilled the dose constrains for target and at risk organs by undergoing HBT in one-third of sessions. We conclude that the planning DVH parameters used in our protocol are clinically feasible.
Games of influence
Authors: Grandi Umberto , Lorini Emiliano , Novaro Arianna , Perrussel Laurent
Published: December 2020

In this paper, we present two models for reasoning about strategic actions in opinion diffusion. In both models, the agents are endowed with goals expressed compactly in a suitably defined language of linear temporal logic and are connected in an influence network which defines the underlying opinion diffusion process. The agents can act by exerting their influence or retain from it: in one case, we assume an initial state of incomplete information about the agents’ opinions, while in the other, we assume that the agents have complete information. We investigate the interplay between simple network structures (e.g. certain acyclic graphs) and the existence of game-theoretic solution concepts for the unanimity aggregator. We also give bounds for the computational complexity of strategic reasoning in both our models on arbitrary networks.
Rapid Deployment of National Guard Alternative Healthcare Facility With Isolation Unit Capabilities in Response to COVID-19
Authors: Torrey Jacob , Orr Jeremy , Florance Jonathon
Published: December 2020

At the direction of Governor Phil Scott, the Vermont National Guard rapidly erected a 400-bed alternative healthcare facility field hospital to increase the state’s medical capacity early in the COVID-19 pandemic when information was limited and cases were rapidly rising across the country. This case study reviews the preparation and management of the alternative healthcare facility’s first COVID-19-positive patient assigned to the 50-bed COVID-19 isolation ward. Despite austere conditions with rudimentary improvements to a nonstandard facility, the ad hoc team composed entirely of members of the Vermont National Guard successfully oversaw patient care from admission to discharge while maintaining a zero-percent transmission rate to staff. While the local civilian medical infrastructure was never overwhelmed and patient census at the facility remained low, this case study highlights the capability of the National Guard enterprise as a community response to pandemic crises.
Scaling relations of fuzzy dark matter haloes – I. Individual systems in their cosmological environment
Authors: Nori Matteo , Baldi Marco
Published: December 2020

Dark matter models involving a very light bosonic particle, generally known as fuzzy dark matter (FDM), have been recently attracting great interest in the cosmology community, as their wave-like phenomenology would simultaneously explain the long-standing misdetection of a dark matter particle and help easing the small-scale issues related to the standard cold dark matter (CDM) scenario. With this work, we initiate a series of papers aiming at investigating the evolution of FDM structures in a cosmological framework performed with our N-body code ax-gadget, detailing for the first time in the literature how the actual scaling relations between solitonic cores and host haloes properties are significantly affected by the dynamical state, morphology, and merger history of the individual systems. In particular, in this first paper we confirm the ability of ax-gadget to correctly reproduce the typical FDM solitonic core and we employ it to study the non-linear evolution of eight FDM haloes in their cosmological context through the zoom-in simulation approach. We find that the scaling relations identified in previous works for isolated systems are generally modified for haloes evolving in a realistic cosmological environment, and appear to be valid only as a limit for the most relaxed and spherically symmetric systems.
Ly α coupling and heating at cosmic dawn
Authors: Mittal Shikhar , Kulkarni Girish
Published: December 2020

The global 21-cm signal from the cosmic dawn is affected by a variety of heating and cooling processes. We investigate the impact of heating due to Ly α photons on the global 21-cm signal at cosmic dawn using an analytical expression of the spectrum around the Ly α resonance based on the so-called ‘wing approximation’. We derive a new expression for the scattering correction and for the first time give a simple close-form expression for the cooling due to injected Ly α photons. We perform a short parameter study by varying the Ly α background intensity by four orders of magnitude and establish that a strong Ly α background is necessary, although not sufficient, in order to reproduce the recently detected stronger-than-expected 21-cm signal by the Experiment to Detect the Global EoR Signal (EDGES) Collaboration. We show that the magnitude of this Ly α heating is smaller than previously estimated in the literature by two orders of magnitude or more. As a result, even a strong Ly α background is consistent with the EDGES measurement. We also provide a detailed discussion on different expressions of the Ly α heating rate used in the literature.
Inferring the lensing rate of LIGO–Virgo sources from the stochastic gravitational wave background
Authors: Mukherjee Suvodip , Broadhurst Tom , Diego Jose M , Silk Joseph , Smoot George F
Published: December 2020

Strong lensing of gravitational waves (GWs) is more likely for distant sources but predicted event rates are highly uncertain with many astrophysical origins proposed. Here, we open a new avenue to estimate the event rate of strongly lensed systems by exploring the amplitude of the stochastic gravitational wave background (SGWB). This method can provide a direct upper bound on the high-redshift binary coalescing rates, which can be translated into an upper bound on the expected rate of strongly lensed systems. We show that from the ongoing analysis of the Laser Interferometer Gravitational-wave Observatory (LIGO)-Virgo and in the future from the LIGO–Virgo design sensitivity stringent bounds on the lensing event rate can be imposed using the SGWB signal. Combining measurements of loud GW events with an unresolved stochastic background detection will improve estimates of the numbers of lensed events at high redshift. The proposed method is going to play a crucial in understanding the population of lensed and unlensed systems from GW observations.
Probing the star formation origin of gamma-rays from 3FHL J1907.0+0713
Authors: Ergin T , Saha L , Bhattacharjee P , Sano H , Tanaka S J , Majumdar P , Yamazaki R , Fukui Y
Published: December 2020

Star-forming (SF) regions embedded inside giant molecular clouds (GMCs) are potential contributors to Galactic gamma-rays. The gamma-ray source 3FHL J1907.0+0713 is detected with a significance of roughly 13σ in the 0.2–300 GeV energy range after the removal of gamma-ray pulsation periods of PSR J1906+0722 from the Fermi-LAT data set of about 10 yr. The energy spectrum of 3FHL J1907.0+0713 is best-fitted to a power-law model with a spectral index of 2.26 ± 0.05. The CO(J = 1−0) data taken by NANTEN2 revealed that 3FHL J1907.0+0713 is overlapping with a GMC having a peak velocity of about 38 km s−1. The best-fitting location of 3FHL J1907.0+0713 is measured to be approximately 0.13 deg away from the Galactic supernova remnant (SNR) 3C 397 and it overlaps with a star that is associated with a bow-shock nebula. We show that there is no physical connection between 3FHL J1907.0+0713, 3C 397, as well as any positional coincidence with the pulsar. The spectrum of 3FHL J1907.0+0713 is fitting to both hadronic and leptonic gamma-ray emission models and the total luminosity at a distance of 2.6 kpc is calculated to be 1.1 × 1034 erg s−1. We also discuss possible SF origins of gamma-rays from 3FHL J1907.0+0713, where SNRs, massive protostar outflows, stellar winds from runaway stars, colliding wind binaries, and young stellar clusters are considered as candidate sources.
Dust reverberation mapping of Z229–15
Authors: Mandal Amit Kumar , Rakshit Suvendu , Stalin C S , Wylezalek Dominika , Patig Markus Kissler , Sagar Ram , Mathew Blesson , Muneer S , Pal Indrani
Published: December 2020

We report results of the dust reverberation mapping (DRM) on the Seyfert 1 galaxy Z229–15 at z = 0.0273. Quasi-simultaneous photometric observations for a total of 48 epochs were acquired during the period 2017 July to 2018 December in B, V, J, H and Ks bands. The calculated spectral index (α) between B and V bands for each epoch was used to correct for the accretion disc (AD) component present in the infrared light curves. The observed α ranges between −0.99 and 1.03. Using cross-correlation function analysis we found significant time delays between the optical V and the AD corrected J, H and Ks light curves. The lags in the rest frame of the source are $12.52^{+10.00}_{-9.55}$ d (between V and J), $15.63^{+5.05}_{-5.11}$ d (between V and H) and $20.36^{+5.82}_{-5.68}$ d (between V and Ks). Given the large error bars, these lags are consistent with each other. However, considering the lag between V and Ks bands to represent the inner edge of the dust torus, the torus in Z229–15 lies at a distance of 0.017 pc from the central ionizing continuum. This is smaller than that expected from the radius luminosity (R−L) relationship known from DRM. Using a constant α = 0.1 to account for the AD component, as is normally done in DRM, the deduced radius (0.025 pc) lies close to the expected R−L relation. However, usage of constant α in DRM is disfavoured as the α of the ionizing continuum changes with the flux of the source.
The impact of Lyα emission line heating and cooling on the cosmic dawn 21-cm signal
Authors: Meiksin Avery , Madau Piero
Published: December 2020

Allowing for enhanced Lyα photon line emission from Population III dominated stellar systems in the first forming galaxies, we show the 21-cm cosmic dawn signal at 10 < $z$ < 30 may substantially differ from standard scenarios. Energy transfer by Lyα photons emerging from galaxies may heat intergalactic gas if H ii regions within galaxies are recombination bound, or cool the gas faster than by adiabatic expansion if reddened by winds internal to the haloes. In some extreme cases, differential 21-cm antenna temperatures near −500 mK may be achieved at 15 < $z$ < 25, similar to the signature detected by the EDGES 21-cm cosmic dawn experiment.
Is GW190521 the merger of black holes from the first stellar generations?
Authors: Farrell Eoin , Groh Jose H , Hirschi Raphael , Murphy Laura , Kaiser Etienne , Ekström Sylvia , Georgy Cyril , Meynet Georges
Published: December 2020

GW190521 challenges our understanding of the late-stage evolution of massive stars and the effects of the pair instability in particular. We discuss the possibility that stars at low or zero metallicity could retain most of their hydrogen envelope until the pre-supernova stage, avoid the pulsational pair-instability regime, and produce a black hole with a mass in the mass gap by fallback. We present a series of new stellar evolution models at zero and low metallicity computed with the geneva and mesa stellar evolution codes and compare to existing grids of models. Models with a metallicity in the range 0–0.0004 have three properties that favour higher black hole (BH) masses. These are (i) lower mass-loss rates during the post main sequence phase, (ii) a more compact star disfavouring binary interaction, and (iii) possible H–He shell interactions which lower the CO core mass. We conclude that it is possible that GW190521 may be the merger of black holes produced directly by massive stars from the first stellar generations. Our models indicate BH masses up to 70–75 M⊙. Uncertainties related to convective mixing, mass loss, H–He shell interactions, and pair-instability pulsations may increase this limit to ∼85 M⊙.
Shell-crossing in a ΛCDM Universe
Authors: Rampf Cornelius , Hahn Oliver
Published: December 2020

Perturbation theory is an indispensable tool for studying the cosmic large-scale structure, and establishing its limits is therefore of utmost importance. One crucial limitation of perturbation theory is shell-crossing, which is the instance when cold-dark-matter trajectories intersect for the first time. We investigate Lagrangian perturbation theory (LPT) at very high orders in the vicinity of the first shell-crossing for random initial data in a realistic three-dimensional Universe. For this, we have numerically implemented the all-order recursion relations for the matter trajectories, from which the convergence of the LPT series at shell-crossing is established. Convergence studies performed at large orders reveal the nature of the convergence-limiting singularities. These singularities are not the well-known density singularities at shell-crossing but occur at later times when LPT already ceased to provide physically meaningful results.
Determination of Pain Phenotypes in Knee Osteoarthritis Using Latent Profile Analysis
Authors: Kittelson Andrew J , Schmiege Sarah J , Maluf Katrina , George Steven Z , Stevens-Lapsley Jennifer E
Published: December 2020

Objective

To identify clinical phenotypes of knee osteoarthritis (OA) using measures from the following domains: 1) multimorbidity; 2) psychological distress; 3) pain sensitivity; and 4) knee impairment or pathology.

Design

Data were collected from 152 people with knee OA and from 31 pain-free individuals. In participants with knee OA, latent profile analysis (LPA) was applied to the following measures: normalized knee extensor strength, Functional Comorbidity Index (FCI), Pain Catastrophizing Scale (PCS), and local (knee) pressure pain threshold. Comparisons were performed between empirically derived phenotypes from the LPA and healthy older adults on these measures. Comparisons were also made between pheonotypes on pain intensity, functional measures, use of health care, and history of knee injury.

Results

LPA resulted in a four-group solution. Compared with all other groups, group 1 (9% of the study population) had higher FCI scores. Group 2 (63%) had elevated pain sensitivity and quadriceps weakness relative to group 4 and healthy older adults. Group 3 (11%) had higher PCS scores than all other groups. Group 4 (17%) had greater leg strength, except relative to healthy older adults, and reduced pain sensitivity relative to all groups. Groups 1 and 3 demonstrated higher pain and worse function than other groups, and group 4 had higher rates of knee injury.

Conclusion

Four phenotypes of knee OA were identified using psychological factors, comorbidity status, pain sensitivity, and leg strength. Follow-up analyses supported the replicability of this phenotype structure, but future research is needed to determine its usefulness in knee OA care.
Trapped modes in a multi-layer fluid
Authors: Cal F S , Dias G A S , Pereira B M M , Videman J H
Published: December 2020

In this article, we study the existence of solutions for the problem of interaction of linear water waves with an array of three-dimensional fixed structures in a density-stratified multi-layer fluid, where in each layer the density is assumed to be constant. Considering time-harmonic small-amplitude motion, we present recursive formulae for the coefficients of the eigenfunctions of the spectral problem associated with the water-wave problem in the absence of obstacles and for the corresponding dispersion relation. We derive a variational and operator formulation for the problem with obstacles and introduce a sufficient condition for the existence of propagating waves trapped in the vicinity of the array of obstacles. We present several (arrays of) structures supporting trapped waves and discuss the possibility of approximating the continuously stratified fluid by a multi-layer model.
Base of thumb osteoarthritis in UK interface services—a cohort and survey-based study to assess current practice
Authors: Dean Benjamin J F , Kluzek Stefan , Carr Andrew J , Hopewell Sally , Richards Duncan , Riley Nicholas , Cuff Andrew ,   Oxford Base of Thumb Collaborative
Published: December 2020

Objective

Base of thumb OA (BTOA) is a common age-related disease that has a significant negative impact on quality of life, while little is known about the structure and pathways of interface services. Our aim was to assess disease burden, referral pathways, service structure and management pathways in UK interface services.

Methods

A structured questionnaire was carried out with a participating clinician at each centre to detail the local guidelines and management of BTOA. Five patients referred with BTOA were prospectively identified in each of 32 UK interface centres.

Results

Most centres (72%) had a local guideline and a standardized treatment regime consisting of education (100%), joint protection (100%), range of motion exercises (84%), strengthening exercises (88%), splintage (100%) and use of assistive devices (78%). No centre routinely offered a steroid injection at the first appointment and no centre had a specific threshold for offering an injection. Injection delivery was variable. Most patients had not been referred previously (82%). Most patients used analgesia (72%), but a minority of patients had been treated with a splint (46%), therapy (43%) and steroid injection (27%) prior to their latest attendance.

Conclusion

Most BTOA patients newly referred to interface services have been treated with analgesics and have not received comprehensive multimodal intervention. The management of BTOA at interface services is standardized in terms of education, splintage and therapy. However, there is a lack of standardization in terms of both the threshold for, timing of and mode of delivery of injection therapy.
Recent studies on railway-track substructure at TTCI
Authors: Li Dingqing , Wilk Stephen
Published: December 2020

Railway-track substructure is the foundation of the railway-track infrastructure and consists of four major components: ballast, sub-ballast, subgrade and drainage. Safety and performance of the track infrastructure, to a large degree, depends on the performance of the track substructure. Adequate support from the track substructure is the most critical element needed for good track performance. When properly constructed and maintained, the ballasted track is the most cost-effective track structure for railway operations, especially for heavy-haul freight operations. Good track-substructure support is characterized by good drainage and strong resistance of the ballast, sub-ballast and subgrade layers to excessive deformation and failures under repeated dynamic wheel loads. As the track substructure plays such important roles, research concerning track substructure has been broad and extensive around the world, with many universities and research institutes conducting various studies and investigations. This paper provides an overview of the recent research conducted at Transportation Technology Center, Inc. (TTCI), a subsidiary of the Association of American Railroads (AAR), in the following areas: ballast mud pumping and its effects on track performance, remediation of subgrade mud pumping, remediation of ballast pockets, ground-penetrating radar (GPR) for inspecting track substructure, and development of software tools with focus on track-substructure functions and management.
Virtual Interviews at Graduate Medical Education Training Programs: Determining Evidence-Based Best Practices
Authors: Huppert Laura A. , Hsiao Edward C. , Cho Kerry C. , Marquez Carina , Chaudhry Rafia I. , Frank James , Goglin Sarah E. , Hsu Gerald , Kathpalia Priya , Khanna Raman , Kompala Tejaswi , Rao Madhu N. , Bower Bree A. , Trafas Vanessa , Santhosh Lekshmi , Schwartz Brian S. , Babik Jennifer M.
Published: December 2020

The COVID-19 pandemic has had a profound impact on the nation’s health care system, including on graduate medical education (GME) training programs. Traditionally, residency and fellowship training program applications involve in-person interviews conducted on-site, with only a minority of programs offering interviews remotely via a virtual platform. However, in light of the COVID-19 pandemic, it is anticipated that most interviews will be conducted virtually for the 2021 application cycle and possibly beyond. Therefore, GME training programs need to prepare for the transition to virtual interviews using evidence-based practices. At the University of California, San Francisco, a multidisciplinary task force was convened to review existing literature about virtual interviews and determine best practices. This article summarizes these findings, first discussing the advantages and disadvantages of the virtual interview format and then providing evidence-based best practices for GME training programs. Specifically, the authors make the following recommendations: develop a detailed plan for the interview process, consider using standardized interview questions, recognize and respond to potential biases that may be amplified with the virtual interview format, prepare your own trainees for virtual interviews, develop electronic materials and virtual social events to approximate the interview day, and collect data about virtual interviews at your own institution. With adequate preparation, the virtual interview experience can be high yield, positive, and equitable for both applicants and GME training programs.
Preoperative and Postoperative, Three-dimensional Gait Analysis in Surgically Treated Patients With High-grade Spondylolisthesis
Authors: Trivedi Jayesh , Srinivas Shreya , Trivedi Rishi , Davidson Neil , Munigangaiah Sudarshan , Bruce Colin , Bass Alf , Wright David
Published: December 2020

Background:

High-grade spondylolisthesis (HGS) (Myerding grade III-V) in adolescents can lead to a marked alteration of gait pattern and maybe the presenting symptom in these patients. This characteristic gait pattern in patients with HGS has been referred to as the “pelvic waddle.” Modern 3-dimensional (3D) gait analysis serves an important tool to objectively analyze the different components of this characteristic gait preoperatively and postoperatively and is an objective measure of postoperative improvement.

This study demonstrates the use of 3D gait analysis preoperatively and postoperatively in a cohort of 4 consecutive patients with HGS treated surgically at a single tertiary referral center and utilize this to objectively evaluate outcome of surgical treatment in these patients. This has not been reported previously in a cohort of patients.

Methods:

This is a prospective analysis of patients with HGS who underwent surgical intervention for spondylolisthesis at a single institution. Patient demographics, clinical, and radiologic assessment were recorded, and all patients underwent 3D gait analysis before and after surgical intervention. Kinetic, kinematic, and spatial parameters were recorded preoperatively and postoperatively for all patients. This allowed the outcome of change in gait deviation index, before and after surgical treatment, to be evaluated.

Results:

We were able to review complete records of 4 adolescent patients who underwent surgical treatment for HGS. Mean age at surgery was 13.5 years with a minimum follow-up of 2.5 years postoperatively (average 40 mo). Preoperative gait analysis revealed marked posterior pelvic tilt in 2 patients, reduced hip and knee extension in all 4 patients and external foot progression in 3 of the 4 patients. Along with an observed improvement in gait, there was an objective improvement in gait parameters postoperatively in all 4 patients. Gait deviation index score improved significantly from 78.9 to 101.3 (mean).

Conclusions:

Preoperative gait abnormalities exist in HGS and can be objectively analyzed with gait analysis. Surgical intervention may successfully resolve these gait abnormalities and gait analysis is a useful tool to assess the outcome of surgery and quantify an otherwise intangible benefit of surgical intervention.

Level of Evidence:

Level IV—case series.
Predictors of Readmission and Prolonged Length of Stay After Cervical Disc Arthroplasty
Authors: Zeidan Michelle , Goz Vadim , Lakomkin Nikita , Spina Nicholas , Brodke Darrel S. , Spiker William R.
Published: December 2020

Study Design.

Retrospective cohort study.

Objective.

The aim of the study was to assess which factors increase risk of readmission within 30 days of surgery or prolonged length of stay (LOS) (≥2 days) after cervical disc arthroplasty (CDA).

Summary of Background Data.

Several studies have shown noninferiority at mid- and long-term outcomes after cervical disc arthroplasty (CDA) compared to anterior cervical discectomy and fusion ACDF, but few have evaluated short-term outcomes regarding risk of readmission or prolonged LOS after surgery.

Methods.

Demographics, comorbidities, operative details, postoperative complications, and perioperative outcomes were collected for patients undergoing single level CDA in the National Surgical Quality Improvement Program (NSQIP) database. Patients with prolonged LOS, defined as >2 days, and readmission within 30 days following CDA were identified. Univariable and multivariable logistic regression models were used to identify risk factors for prolonged LOS and readmission.

Results.

A total of 3221 patients underwent single level CDA. Average age was 45.6 years (range 19–82) and 53% of patients were male. A total of 472 (14.7%) experienced a prolonged LOS and 36 (1.1%) patients were readmitted within 30 days following surgery. Predictors of readmission were postoperative superficial wound infection (odds ratio [OR] = 73.83, P < 0.001), American Society of Anesthesiologists (ASA) classification (OR = 1.98, P = 0.048), and body mass index (BMI) (OR = 1.06, P = 0.02). Female sex (OR = 1.76, P < 0.001), diabetes (OR = 1.50, P = 0.024), postoperative wound dehiscence (OR = 13.11, P = 0.042), ASA class (OR = 1.43, P < 0.01), and operative time (OR = 1.01, P < 0.001) were significantly associated with prolonged LOS.

Conclusion.

From a nationwide database analysis of 3221 patients, wound complications are predictors of both prolonged LOS and readmission. Patient comorbidities, including diabetes, higher ASA classification, female sex, and higher BMI also increased risk of prolonged LOS or readmission.

Level of Evidence: 3