bluuebunny/crossref_metadata_2025 huggingface dataset:
Dynamic Contrast Magnetic Resonance Lymphangiography Localizes Lymphatic Leak to the Duodenum in Protein‐Losing Enteropathy
Authors: Brownell Jefferson N. , Biko David M. , Mamula Petar , Krishnamurthy Ganesh , Escobar Fernando , Srinivasan Abhay , Laje Pablo , Piccoli David A. , Pinto Erin , Smith Christopher L. , Dori Yoav
Published: August 2021

Objectives:

Protein‐losing enteropathy (PLE) is a disorder of intestinal lymphatic flow resulting in leakage of protein‐rich lymph into the gut lumen. Our primary aim was to report the imaging findings of dynamic contrast magnetic resonance lymphangiography (DCMRL) in patients with PLE. Our secondary objective was to use these imaging findings to characterize lymphatic phenotypes.

Methods:

Single‐center retrospective cohort study of patients with PLE unrelated to single‐ventricle circulation who underwent DCMRL. We report imaging findings of intranodal (IN), intrahepatic (IH), and intramesenteric (IM) access points for DCMRL.

Results:

Nineteen patients 0.3–58 years of age (median 1.2 years) underwent 29 DCMRL studies. Primary intestinal lymphangiectasia (PIL) was the most common referring diagnosis (42%). Other etiologies included constrictive pericarditis, thoracic insufficiency syndrome, and genetic disorders. IN‐DCMRL demonstrated a normal central lymphatic system in all patients with an intact thoracic duct and localized duodenal leak in one patient (1/19, 5%). IH‐DCMRL detected a duodenal leak in 12 of 17 (71%), and IM‐DCMRL detected duodenal leak in 5 of 6 (83%). Independent of etiology, lymphatic leak was only visualized in the duodenum.

Conclusions:

In patients with PLE, imaging via DCMRL reveals that leak is localized to the duodenum regardless of etiology. Comprehensive imaging evaluation with three access points can provide detailed information about the site of duodenal leak.
Predictors of Attempted Suicide Among Youth Living With Perinatal HIV Infection and Perinatal HIV-Exposed Uninfected Counterparts
Authors: Kreniske Philip , Mellins Claude Ann , Dolezal Curtis , Morrison Corey , Shea Eileen , Fisher Prudence W. , Kluisza Luke , Robbins Reuben N. , Nguyen Nadia , Leu Cheng-Shiun , Wiznia Andrew , Abrams Elaine J.
Published: August 2021

Background:

Suicide is a leading cause of death among adolescents and young adults (AYA). AYA living with perinatally acquired HIV infection (AYALPHIV) are at higher risk of attempted suicide when compared with AYA who were perinatally HIV-exposed but uninfected (AYAPHEU). To inform interventions, we identified risk and protective factors of attempted suicide among AYALPHIV and AYAPHEU.

Setting:

Data were obtained from a longitudinal New York City–based study of AYALPHIV and AYAPHEU (n = 339; enrollment age 9–16 years) interviewed approximately every 12–18 months.

Method:

Our main outcome was suicide attempt at any follow-up. The DISC was used to assess psychiatric disorder diagnoses and attempted suicide and the Child Depression Inventory to assess depressive symptoms. Psychosocial and sociodemographic risk factors were also measured. Analyses used backward stepwise logistic regression modeling.

Results:

At enrollment, 51% was female individuals, 49% Black, 40% Latinx, and 11% both Black and Latinx. Attempted suicide prevalence was significantly higher among AYALPHIV compared with AYAPHEU (27% vs 16%,P= 0.019), with AYALPHIV having 2.21 times the odds of making an attempt [95% confidence interval: (1.18 to 4.12),P= 0.013]. Higher Child Depression Inventory scores were associated with an increased risk of attempted suicide in both groups and the total sample. The presence of DISC-defined behavior disorder increased the risk of attempted suicide in the total sample and the AYALPHIV subgroup. Religiosity was protective of attempted suicide in AYALPHIV.

Conclusions:

AYALPHIV had increased suicide attempts compared with AYAPHEU. Religiosity was protective in AYALPHIV. Highlighting a need for prevention, early mental health challenges were associated with risk.
Computed Tomography–Determined Body Composition Abnormalities Usefully Predict Long-term Mortality in Patients With Liver Cirrhosis
Authors: Cho Young Seo , Lee Ha Young , Jeong Jae Yoon , Lee Jae Gon , Kim Tae Yeob , Nam Seong Woo , Sohn Joo Hyun
Published: August 2021

Objective

We evaluated the prognostic impacts of body composition components measured by computed tomography (CT) in patients with liver cirrhosis.

Methods

A total of 160 cirrhotic patients who underwent CT and hepatic venous pressure gradient measurements were retrospectively enrolled. Cross-sectional areas of skeletal muscle, visceral and subcutaneous fat, and mean CT attenuation of trabecular bone of the fourth lumbar vertebral level (L4HU) were measured.

Results

Multivariate analysis showed model for end-stage liver disease score [hazard ratio (HR), 1.086; 95% confidence interval (CI), 1.020–1.156; P = 0.010], hepatic venous pressure gradient (HR, 1.076; 95% CI, 1.021–1.135; P = 0.006), sarcopenia (HR, 1.890; 95% CI, 1.032–3.462; P = 0.039), and L4HU (HR, 1.960 for L4HU <145 Hounsfield units; 95% CI, 1.094–3.512; P = 0.024) were independently associated with long-term mortality. In patients with decompensated cirrhosis, subcutaneous adipose tissue index was the only independent predictor (HR, 0.984; 95% CI, 0.969–0.999; P = 0.039).

Conclusion

Body composition abnormalities determined by CT are associated with long-term prognosis in cirrhotic patients.
Feasibility of Dual-Energy Computed Tomography Imaging of Gadolinium-Based Contrast Agents and Its Application in Computed Tomography Cystography: An Exploratory Study to Assess an Alternative Option When Iodinated Contrast Agents Are Contraindicated
Authors: Nogel Stephen J. , Ren Liqiang , Yu Lifeng , Takahashi Naoki , Froemming Adam T.
Published: August 2021

Objective

The aim of this study was to compare the contrast enhancement differences between gadolinium-based and iodine-based contrast agents at different single-energy tube potentials and dual-energy–based virtual monochromatic energies. In addition, we describe the application of a gadolinium-based contrast agent in computed tomography (CT) cystography for a patient with contraindications to iodine.

Methods

A phantom study was performed using 3 iodine samples (concentrations: 5, 10, and 15 mgI/mL) and 3 gadolinium samples (concentrations: 3.3, 6.6, and 9.9 mgGd/mL). The prepared phantom was scanned by a dual-energy CT (DECT) at 80, 100, 120, and 140 kV in the single-energy mode and at 100/Sn140 kV in the dual-energy mode. Virtual monoenergetic images (VMIs) at 50 keV were generated from the DECT scan. In addition, a DECT cystogram was performed using a gadolinium-based contrast agent in a patient with contraindications to iodinated contrast.

Results

Strong linear correlations between mean signal of contrast enhancement and mass concentration were found for both iodine and gadolinium samples across all single-energy CT (SECT) and DECT scan conditions. The VMI at 50 keV provided the highest contrast enhancement for both types of contrast samples at each concentration level, and single-energy CT scans at low-energy beams showed higher contrast enhancement than higher beam energies. In addition, the contrast enhancement for pure gadolinium solution was constantly higher than pure iodine solution at an identical mass concentration level. The DECT cystogram was performed with excellent technical success. The urinary bladder was appropriately distended with intravesical contrast measuring 606 Hounsfield units and no evidence of bladder leak or fistula.

Conclusions

Imaging of gadolinium-based contrast agents is improved using a DECT technique, with VMI at 50 keV providing the highest contrast enhancement among our tested parameters. Dual-energy CT cystography using a gadolinium-based agent can be a safe and effective alternative when iodinated agents are contraindicated.
MDP SPECT/CT Demonstration of Baastrup Disease
Authors: Zhang Yu , Liu Huipan , Zhang Wei , Chen Yue
Published: August 2021

We report the MDP SPECT/CT findings of Baastrup disease in the interspinal region of L4 to L5 in a 76-year-old woman with a history of lung cancer. Baastrup disease, also known as “kissing” spine, is characterized by close contact of adjacent spinous processes with resultant enlargement, flattening, and reactive sclerosis of apposing interspinous surfaces. Knowledge regarding the appearance of Baastrup disease on 99mTc-MDP SPECT/CT is important to distinguish it from spinal bone metastasis.
Long-term pulmonary function, thoracic pain, and quality of life in patients with one or more rib fractures
Authors: Prins Jonne T.H. , Van Lieshout Esther M.M. , Overtoom Hidde C.G. , Tekin Yusuf S. , Verhofstad Michael H.J. , Wijffels Mathieu M.E.
Published: August 2021

BACKGROUND

Long-term outcomes after rib fractures and the effect of treatment modality or chest wall injury severity on these outcomes remains uncertain. This retrospective cohort study evaluated the long-term pulmonary function, thoracic pain, and quality of life in patients admitted with rib fractures.

METHODS

Patients admitted with rib fractures between January 1, 2012, and December 1, 2019, were included. Data on long-term outcomes were collected during one follow-up visit. Patients were stratified by chest wall injury severity (one or two rib fractures, ≥3 rib fractures, or a flail chest) and treatment modality (surgical stabilization of rib fractures [SSRF] or nonoperative management). Multivariable analysis was performed to compare outcomes after SSRF with nonoperative treatment in patients with three or more rib fractures.

RESULTS

In total, 300 patients were included. The median follow-up was 39 months (P25–P75, 18–65 months). At follow-up, the corrected forced vital capacity returned to 84.7% (P25–P75, 74.3–93.7) and the forced expiratory volume in 1 second to 86.3% (P25–P75, 75.3–97.0) of the predicted reference values. Quality of life was determined using the Short Form-12 version 2 and EuroQoL-5D-5L. The Short Form-12 version 2 physical and mental component summary were 45 (P25-P75, 38–54) and 53 (P25-P75, 43–60), respectively. The EuroQoL-5D-5L utility score was 0.82 (P25–P75 0.66–0.92) and visual analog scale score 75 (P25–P75 70–85). This indicated a quality of life within normal population ranges. Moderate to severe thoracic pain was reported by 64 (21.3%) patients. Long-term outcomes returned to values within population ranges and were similar across chest wall injury severity and for patients treated with SSRF or nonoperatively.

CONCLUSION

While long-term pulmonary function and quality of life recover to values considered normal, subjective thoracic complaints, such as pain and dyspnea, remain frequently present following rib fractures. No effect of chest wall injury severity or treatment modality on long-term outcomes was demonstrated.

LEVEL OF EVIDENCE

Therapeutic, level III
Sub-spreading events limit the reliable elimination of heterogeneous epidemics
Authors: Parag Kris V.
Published: August 2021

We show that sub-spreading events, i.e. transmission events in which an infection propagates to few or no individuals, can be surprisingly important for defining the lifetime of an infectious disease epidemic and hence its waiting time to elimination or fade-out, measured from the time-point of its last observed case. While limiting super-spreading promotes more effective control when cases are growing, we find that when incidence is waning, curbing sub-spreading is more important for achieving reliable elimination of the epidemic. Controlling super-spreading in this low-transmissibility phase offers diminishing returns over non-selective, population-wide measures. By restricting sub-spreading, we efficiently dampen remaining variations among the reproduction numbers of infectious events, which minimizes the risk of premature and late end-of-epidemic declarations. Because case-ascertainment or reporting rates can be modelled in exactly the same way as control policies, we concurrently show that the under-reporting of sub-spreading events during waning phases will engender overconfident assessments of epidemic elimination. While controlling sub-spreading may not be easily realized, the likely neglecting of these events by surveillance systems could result in unexpectedly risky end-of-epidemic declarations. Super-spreading controls the size of the epidemic peak but sub-spreading mediates the variability of its tail.
Taylor White's ‘paper museum’
Authors: Dickenson Victoria , Garland Jennifer
Published: August 2021

For almost 40 years, the British jurist and Fellow of the Royal Society Taylor White (1701–1772) actively engaged in commissioning artists to paint plants and animals for his ‘paper museum’. White amassed a collection of almost 1000 drawings of birds, mammals, fish, amphibians and reptiles, acquired by McGill University in 1927. His first recorded purchase was a watercolour by George Edwards (1694–1773). He also acquired works from Eleazar Albin (
fl.
 1690–
ca
 1742) and Jacob van Huysum (
ca
 1687–1740), but the majority of the watercolours were painted by two artists, Charles Collins (
ca
 1680–1744) and Peter Paillou (
ca
 1712–1782). In 2018 a research group at McGill University Library received funding from the Social Sciences and Humanities Research Council of Canada for the project ‘Undescrib'd: Taylor White's paper museum’. The project produced a complete catalogue of the White collection, including attribution of all unsigned works, and digitized all paintings and notes. This paper documents the process surrounding the original creation of the collection, reviewing the careers of the artists and White's relationship with them, the value of the commissions and the challenges of painting natural history subjects. It also describes the mechanics of painting, including pigments, papers used and artists' techniques.
Conceptually plausible Bayesian inference in interval timing
Authors: Maaß Sarah C. , de Jong Joost , van Maanen Leendert , van Rijn Hedderik
Published: August 2021

In a world that is uncertain and noisy, perception makes use of optimization procedures that rely on the statistical properties of previous experiences. A well-known example of this phenomenon is the central tendency effect observed in many psychophysical modalities. For example, in interval timing tasks, previous experiences influence the current percept, pulling behavioural responses towards the mean. In Bayesian observer models, these previous experiences are typically modelled by unimodal statistical distributions, referred to as the prior. Here, we critically assess the validity of the assumptions underlying these models and propose a model that allows for more flexible, yet conceptually more plausible, modelling of empirical distributions. By representing previous experiences as a mixture of lognormal distributions, this model can be parametrized to mimic different unimodal distributions and thus extends previous instantiations of Bayesian observer models. We fit the mixture lognormal model to published interval timing data of healthy young adults and a clinical population of aged mild cognitive impairment patients and age-matched controls, and demonstrate that this model better explains behavioural data and provides new insights into the mechanisms that underlie the behaviour of a memory-affected clinical population.
Personality first in emotion: a deep neural network based on electroencephalogram channel attention for cross-subject emotion recognition
Authors: Tian Zhihang , Huang Dongmin , Zhou Sijin , Zhao Zhidan , Jiang Dazhi
Published: August 2021

In recent years, more and more researchers have focused on emotion recognition methods based on electroencephalogram (EEG) signals. However, most studies only consider the spatio-temporal characteristics of EEG and the modelling based on this feature, without considering personality factors, let alone studying the potential correlation between different subjects. Considering the particularity of emotions, different individuals may have different subjective responses to the same physical stimulus. Therefore, emotion recognition methods based on EEG signals should tend to be personalized. This paper models the personalized EEG emotion recognition from the macro and micro levels. At the macro level, we use personality characteristics to classify the individuals’ personalities from the perspective of ‘birds of a feather flock together’. At the micro level, we employ deep learning models to extract the spatio-temporal feature information of EEG. To evaluate the effectiveness of our method, we conduct an EEG emotion recognition experiment on the ASCERTAIN dataset. Our experimental results demonstrate that the recognition accuracy of our proposed method is 72.4% and 75.9% on valence and arousal, respectively, which is 10.2% and 9.1% higher than that of no consideration of personalization.
A superfine glass fibre air filter with rapid response to photocatalytic antibacterial properties under visible light by loading rGO/ZnO
Authors: Luo Yongyi , Zhai Fuqiang , Zhang Yingchun , Chen Zhiqian , Ding Mingde , Qin Dajiang , Yang Jinming , Feng Guang , Li Lu
Published: August 2021

The development of high-performance air filter has become more and more important to public health. However, it has always been very challenging for developing a multifunctional air filter to simultaneously achieve excellent filtration and antibacterial properties. Herein, a versatile air filter was prepared with loading the reduced graphene (rGO) and zinc oxide on the superfine glass fibre (s-GF) with the three-dimensional network structure byin situsol–gel process followed by calcination, which aims to achieve synergistic high-efficiency air filtration and rapid response to photocatalytic antibacterial properties under visible light. The air filter showed a three-dimensional network structure based on a rGO/ZnO/s-GF multilayer and exhibited the highest catalytic performance by achieving a 95% degradation effect on rhodamine B within 2 h and achieving 100% antibacterial inactivation of theEscherichia coliandStaphylococcus aureuswithin 4 h under visible light when the weight ratio of rGO in rGO/ZnO is 1.6%. The air filtration efficiency can also be maintained at 99% after loading ZnO and rGO photocatalytic particles. The spectrum of the photoluminescence (PL), UV-Vis diffuse reflectance spectra (DRS) and electron spin resonance (ESR) indicate that the combination of rGO and ZnO on the s-GF can increase the separation of photogenerated carriers and the specific surface area of the air filter, thereby increasing the photocatalytic response and antibacterial properties of the s-GF air filter under visible light in a short time.
New fossils of Jurassic ophiurid brittle stars (Ophiuroidea; Ophiurida) provide evidence for early clade evolution in the deep sea
Authors: Thuy Ben , Numberger-Thuy Lea D. , Pineda-Enríquez Tania
Published: August 2021

Understanding of the evolutionary history of the ophiuroids, or brittle stars, is hampered by a patchy knowledge of the fossil record. Especially, the stem members of the living clades are poorly known, resulting in blurry concepts of the early clade evolution and imprecise estimates of divergence ages. Here, we describe new ophiuroid fossil from the Lower Jurassic of France, Luxembourg and Austria and introduce the new taxaOphiogojira labadieigen. et sp. nov. from lower Pliensbachian shallow sublittoral deposits,Ophiogojira andreuigen. et sp. nov. from lower Toarcian shallow sublittoral deposits andOphioduplantiera noctilucagen. et sp. nov. from late Sinemurian to lower Pliensbachian bathyal deposits. A Bayesian morphological phylogenetic analysis shows thatOphiogojiraholds a basal position within the order Ophiurida, whereasOphioduplantierahas a more crownward position within the ophiurid family Ophiuridae. The position ofOphioduplantierain the evolutionary tree suggests that family-level divergences within the Ophiurida must have occurred before the late Sinemurian, and that ancient slope environments played an important role in fostering early clade evolution.
Nanoscale zero-valent iron loaded vermiform expanded graphite for the removal of Cr (VI) from aqueous solution
Authors: Cai Xinwei , Qiu Yangshuai , Zhou Yanhong , Jiao Xuan
Published: August 2021

Cr (VI) is indispensable in industrial manufacturing, and its extensive use leads to severe heavy-metal pollution in the water environment around people, posing a great danger to physical health and living environment of multitudinous organisms. Expanded graphite (EG) is considered as a typical material for adsorption, while nanoscale zero-valent iron (nZVI) can be applied to degrade and sedimentate various organic or inorganic pollutants. In this study, a simultaneous collaboration of EG and nZVI is carried out, with the investigation on the influence of different test conditions for adsorption performances. These findings demonstrate that nZVI@EG manifests favourable adsorptive performance on the removal of hexavalent chromium efficiently. nZVI, acting as an electron donor, is supposed to reduce Cr (VI) to Cr (III), turning itself into iron oxide or hydroxide. The whole process is an exothermic reaction, accompanying chemical reduction and physical adsorption. And Cr (III) is fastened on the appearance by deposition of chromium hydroxide or ferrochromium complex precipitation, which greatly reduces the total chromium content in the aqueous solution. Herein, as a new composite adsorbent, nZVI@EG shows promising prospects of practical applications in water contamination and environmental remediation.
All sugars ain't sweet: selection of particular mono-, di- and trisaccharides by western carpenter ants and European fire ants
Authors: Renyard Asim , Gries Regine , Lee Jan , Chalissery Jaime M. , Damin Sebastian , Britton Robert , Gries Gerhard
Published: August 2021

Ants select sustained carbohydrate resources, such as aphid honeydew, based on many factors including sugar type, volume and concentration. We tested the hypotheses (H1–H3) that western carpenter ants,Camponotus modoc,seek honeydew excretions fromCinara splendensaphids based solely on the presence of sugar constituents (H1), prefer sugar solutions containing aphid-specific sugars (H2) and preferentially seek sugar solutions with higher sugar content (H3). We further tested the hypothesis (H4) that workers of bothCa. modocand European fire ants,Myrmica rubra, selectively consume particular mono-, di- and trisaccharides. In choice bioassays with entire ant colonies, sugar constituents in honeydew (but not aphid-specific sugar) as well as sugar concentration affected foraging decisions byCa. modoc. BothCa. modocandM. rubraforagers preferred fructose to other monosaccharides (xylose, glucose) and sucrose to other disaccharides (maltose, melibiose, trehalose). Conversely, when offered a choice between the aphid-specific trisaccharides raffinose and melezitose,Ca. modocandM. rubrafavoured raffinose and melezitose, respectively. Testing the favourite mono-, di- and trisaccharide head-to-head, both ant species favoured sucrose. While both sugar type and sugar concentration are the ultimate cause for consumption by foraging ants, strong recruitment of nest-mates to superior sources is probably the major proximate cause.
Simple, low-cost and accurate data-driven geophysical forecasting with learned kernels
Authors: Hamzi B. , Maulik R. , Owhadi H.
Published: August 2021

Modelling geophysical processes as low-dimensional dynamical systems and regressing their vector field from data is a promising approach for learning emulators of such systems. We show that when the kernel of these emulators is also learned from data (using kernel flows, a variant of cross-validation), then the resulting data-driven models are not only faster than equation-based models but are easier to train than neural networks such as the long short-term memory neural network. In addition, they are also more accurate and predictive than the latter. When trained on geophysical observational data, for example the weekly averaged global sea-surface temperature, considerable gains are also observed by the proposed technique in comparison with classical partial differential equation-based models in terms of forecast computational cost and accuracy. When trained on publicly available re-analysis data for the daily temperature of the North American continent, we see significant improvements over classical baselines such as climatology and persistence-based forecast techniques. Although our experiments concern specific examples, the proposed approach is general, and our results support the viability of kernel methods (with learned kernels) for interpretable and computationally efficient geophysical forecasting for a large diversity of processes.
Fracture modelling of plain concrete using non-local fracture mechanics and a graph-based computational framework
Authors: Thamburaja P. , Sarah K. , Srinivasa A. , Reddy J. N.
Published: August 2021

In this article, we developed a thermodynamically consistent non-local microcracking model for quasi-brittle materials with application to concrete. The model is implemented using a novel graph-based finite element analysis (GraFEA) approach that allows for (i) the probabilistic modeling of the growth and coalescence of microcracks, (ii) the modeling of crack closure using a kinematics-based approach, and (iii) the modeling of rate effects on microcracking. The developed theoretical model and its computational framework is also implemented into the dynamics-based Abaqus/Explicit finite element program through a vectorized user-material subroutine interface. We further demonstrate the procedure for obtaining the parameters (including the non-local intrinsic material length scale, which governs the fracture process) and consequently validate the simulations with independent experimental results.
A new integrable model of long wave–short wave interaction and linear stability spectra
Authors: Caso-Huerta Marcos , Degasperis Antonio , Lombardo Sara , Sommacal Matteo
Published: August 2021

We consider the propagation of short waves which generate waves of much longer (infinite) wavelength. Model equations of such long wave–short wave (LS) resonant interaction, including integrable ones, are well known and have received much attention because of their appearance in various physical contexts, particularly fluid dynamics and plasma physics. Here we introduce a new LS integrable model which generalizes those first proposed by Yajima and Oikawa and by Newell. By means of its associated Lax pair, we carry out the linear stability analysis of its continuous wave solutions by introducing the
stability spectrum
as an algebraic curve in the complex plane. This is done starting from the construction of the eigenfunctions of the linearized LS model equations. The geometrical features of this spectrum are related to the stability/instability properties of the solution under scrutiny. Stability spectra for the plane wave solutions are fully classified in the parameter space together with types of modulational instabilities.
Under-Oil Autonomously Regulated Oxygen Microenvironments: A Goldilocks Principle-Based Approach For Microscale Cell Culture
Authors: Li Chao , Humayun Mouhita , Walker Glenn M. , Park Keon Young , Connors Bryce , Feng Jun , Pellitteri Hahn Molly C. , Scarlett Cameron O. , Li Jiayi , Feng Yanbo , Clark Ryan L. , Hefti Hunter , Schrope Jonathan , Venturelli Ophelia S. , Beebe David J.
Published: August 2021

Oxygen levelsin vivoare autonomously regulated by a supply-demand balance, which can be altered in disease states. However, the oxygen levels ofin vitrocell culture systems, particularly microscale cell culture, are typically dominated by either supply or demand. Further, the oxygen microenvironment in these systems are rarely monitored or reported. Here, we present a method to establish and dynamically monitor autonomously regulated oxygen microenvironments (AROM) using an oil overlay in an open microscale cell culture system. Using this method, the oxygen microenvironment is dynamically regulated via a supply-demand balance of the system. We simulate the kinetics of oxygen diffusion in multiliquid-phase microsystems on COMSOL Multiphysics and experimentally validate the method using a variety of cell types including mammalian, fungal and bacterial cells. Finally, we demonstrate the utility of this method to establish a co-culture between primary intestinal epithelial cells and a highly prevalent human gut speciesBacteroides uniformis.
Robust SARS-CoV-2-specific and heterologous immune responses after natural infection in elderly residents of Long-Term Care Facilities
Authors: Tut Gokhan , Lancaster Tara , Butler Megan S. , Sylla Panagiota , Spalkova Eliska , Bone David , Kaur Nayandeep , Bentley Christopher , Amin Umayr , Jadir Azar T. , Hulme Samuel , Ayodel Morenike , Dowell Alexander C. , Pearce Hayden , Margielewska-Davies Sandra , Verma Kriti , Nicol Samantha , Begum Jusnara , Blakeway D. , Jinks Elizabeth , Tut Elif , Bruton Rachel , Krutikov Maria , Shrotri Madhumita , Giddings Rebecca , Azmi Borscha , Fuller Chris , Irwin-Singer Aidan , Hayward Andrew , Copas Andrew , Shallcross Laura , Moss Paul
Published: August 2021

Long term care facilities (LTCF) provide residential and/or nursing care support for frail and elderly people and many have suffered from a high prevalence of SARS-CoV-2 infection. Although mortality rates have been high in LTCF residents there is little information regarding the features of SARS-CoV-2-specific immunity after infection in this setting or how this may influence immunity to other infections. We studied humoral and cellular immunity against SARS-CoV-2 in 152 LTCF staff and 124 residents over a prospective 4-month period shortly after the first wave of infection and related viral serostatus to heterologous immunity to other respiratory viruses and systemic inflammatory markers. LTCF residents developed high levels of antibodies against spike protein and RBD domain which were stable over 4 months of follow up. Nucleocapsid-specific responses were also elevated in elderly donors but showed waning across all populations. Antibodies showed stable and equivalent levels of functional inhibition against spike-ACE2 binding in all age groups with comparable activity against viral variants of concern. SARS-CoV-2 seropositive donors showed high levels of antibodies to other beta-coronaviruses but serostatus did not impact humoral immunity to influenza or RSV. SARS-CoV-2-specific cellular responses were equivalent across the life course but virus-specific populations showed elevated levels of activation in older donors. LTCF residents who are survivors of SARS-CoV-2 infection thus show robust and stable immunity which does not impact responses to other seasonal viruses. These findings augur well for relative protection of LTCF residents to re-infection. Furthermore, they underlie the potent influence of previous infection on the immune response to Covid-19 vaccine which may prove to be an important determinant of future vaccine strategy.

One sentence summery

Care home residents show waning of nucleocapsid specific antibodies and enhanced expression of activation markers on SARS-CoV-2 specific cells
Adjusting for time of infection or positive test when estimating the risk of a post-infection outcome in an epidemic
Authors: Seaman Shaun R. , Nyberg Tommy , Overton Christopher E. , Pascall David , Presanis Anne M. , De Angelis Daniela
Published: August 2021

When comparing the risk of a post-infection binary outcome, e.g. hospitalisation, for two variants of an infectious pathogen, it is important to adjust for calendar time of infection to avoid the confounding that would occur if the relative incidence of the two variants and the variant-specific risks of the outcome both change over time. Infection time is typically unknown and time of positive test used instead. Likewise, time of positive test may be used instead of infection time when assessing how the risk of the binary outcome changes over calendar time. Here we show that if mean time from infection to positive test is correlated with the outcome, the risk conditional on positive test time depends on whether incidence of infection is increasing or decreasing over calendar time. This complicates interpretation of risk ratios adjusted for positive test time. We also propose a simple sensitivity analysis that indicates how these risk ratios may differ from the risk ratios adjusted for infection time.
A second dramatic rise in seroprevalence rates of SARS-CoV-2 antibodies among adult healthy blood donors in Jordan; have we achieved herd immunity?
Authors: Sughayer Maher A. , Mansour Asem , Nuirat Abeer Al , Souan Lina , Abdel-Razeq Rashid , Siag Mahmoud
Published: August 2021

Objectives

To determine the impact of the second wave of COVID-19 and the vaccination campaign on the seroprevalence rates of SARS-CoV-2 antibodies among healthy blood donors in Jordan.

Methods

Sera from 536 healthy adult blood donors collected in June -2021 were tested using a commercially available quantitative assay for the total antibodies including IgG against the spike (S) protein receptor binding domain (RBD) of the SARS-CoV-2.

Results

399 (74.4%) of the donors tested positive for the antibodies of whom 69 (17.3%) were confirmed to have been previously infected, 245(61.4%) have received at least one dose of the vaccine and 123(30.8%) were neither diagnosed nor vaccinated. The seropositive donors were significantly more likely to have been vaccinated or previously infected.

Conclusion

The crude seroprevalence rate of 74.4% among this group of healthy donors may be encouraging in terms of approaching herd immunity, however with predominance of the delta variant and the uncertainty regarding the required level of herd immunity this goal appears to be far from full achievement in Jordan.
Longitudinal changes in age and race of patients with SARS-CoV-2 in a multi-hospital health system
Authors: Barbash Ian J. , Harrison Lee H. , Jacobs Jana L. , Shah Faraaz Ali , Suber Tomeka L. , Quinn Kevin L. , Marroquin Oscar C. , Gladwin Mark T. , Sackrowitz Rachel E. , Morris Alison
Published: August 2021

Background

The COVID-19 pandemic continues to affect the United States and the world. Media reports have suggested that the wave of the alpha variant in the Spring of 2021 in the US caused more cases among younger patients and racial and ethnic subgroups.

Approach

We analyzed electronic health record data from a multihospital health system to test whether younger patients accounted for more cases and more severe disease, and whether racial disparities are widening. We compared demographics, patient characteristics, and hospitalization variables for patients admitted from November 2020 through January 2021 to those admitted in March and April 2021.

Results

We analyzed data for 37, 502 unique inpatients and outpatients at 21 hospitals from November 1, 2020 to April 30, 2021. Compared to patients from November through January, those with positive tests in March and April were younger and less likely to die. Among patients under age 50, those with positive tests in March and April were three times as likely to be hospitalized and twice as likely to require ICU admission or mechanical ventilation. Individuals identified as Black represented a greater proportion of cases and hospitalizations in March and April as compared to November through January.

Conclusions

We found that relative COVID-19 hospitalization rates for younger individuals and individuals identified as Black were rising over time. These findings have important implications for ongoing public health measures to mitigate the impact of the pandemic.
Cost-effectiveness analysis of Intravascular Temperature Management after cardiac arrest in England
Authors: Yaghoubi Mohsen , Javanbakht Mehdi , Mashayekhi Atefeh , Hemami Mohsen Rezaei , Branagan-Harris Michael , Keeble Thomas R
Published: August 2021

Background

Although there is recognized that Targeted Temperature Management (TTM) can improve neurological outcomes and survival in patients resuscitated from out of hospital cardiac arrest, the cost-effectiveness of multiple methods of TTM is still uncertain.

Objective

This study aimed to evaluate the cost-effectiveness of Intravascular Temperature Management (IVTM) through Thermogard XP in targeted temperature management compared to surface cooling method after cardiac arrest in England.

Methods

We developed a multi-state Markov model that compared intravascular temperature management through Thermogard XP and the surface cooling method through two different devices including Blanketrol III and Arctic Sun 5000, over a short-term and lifetime horizon. Model input parameters were obtained from the literature and local databases. We assumed hypothetical cohort of 1,000 patients who need TTM after cardiac arrest per year in England. The outcomes were costs (in 2019 £) and quality-adjusted life-years (QALYs), discounted at 3.5% annually. Deterministic and probabilistic analyses were undertaken to examine the effect of alternative assumptions and uncertainty in model parameters on the results.

Results

In a simulated cohort of 1,000 patients who need TTM, the Thermogard XP resulted in direct cost savings of £2,339 and £2,925 (per patient) when compared with Blanketrol III and Arctic Sun 5000 respectively, and a gain of 0.98 QALYs over the patient lifetime. Total cost saving considering cohort of 1,000 patients is £2,339,479 and £ 2,925,109 when using IVTM through Thermogard XP compared with Blanketrol III and Arctic Sun 5000 respectively in life-time horizon. Results were robust against alternative assumptions, changes in values of input parameters, and alternative time horizons.

Conclusion

Implementation of intravascular temperature management using Thermogard XP can lead to cost-savings and improvement in patients’ quality of life versus surface cooling methods.
The Impact of COVID-19 Testing on College Campuses*
Authors: Yu Zhuoting , Fujimoto Akane B. , Keskinocak Pinar , Swann Julie L.
Published: August 2021

Background

After moving instruction online for more than a year, many colleges and universities are preparing to reopen and offering fully in-person classes for the Fall 2021 semester. In this paper, we study the impact of weekly testing protocols on college campuses.

Methods

An extended susceptible–infectious–removed (SIR) compartmental model was used to simulate COVID-19 spread on a college campus setting. Seven scenarios were evaluated which considered polymerase chain reaction (PCR) and rapid antigen testing kits available at various levels of supply. The infection attack rate (IAR), the number of infections, and the number of tests utilized by the end of the simulation semester are reported and compared.

Results

Weekly testing significantly reduces the number of infections compared to when testing is not available. The use of PCR tests results in the lowest infection attack rate and the total number of cases; however, using rapid antigen tests with higher coverage is more effective than using PCR tests with lower coverage.

Conclusions

The implementation of COVID-19 testing protocols should be considered and evaluated as using testing allows for identification and isolation of cases which reduces the spread of COVID-19 on college campuses. Even if testing capacity is limited, its partial implementation can be beneficial.
Fitness effects of CTX-M-15-encoding IncF plasmids on their native Escherichia coli ST131 H30Rx hosts
Authors: Palkovicova Jana , Kutilova Iva , DelaFuente Javier , Valcek Adam , Medvecky Matej , Jamborova Ivana , Bitar Ibrahim , Phan Minh Duy , Millan Alvaro San , Dolejska Monika
Published: August 2021

Objectives

The objective of this study was to investigate effects of large CTX-M-15-encoding IncF plasmids on the fitness of their native E. coli ST131 H30Rx hosts in order to understand possible plasmid-host coevolution.

Methods

We selected five E. coli ST131 H30Rx strains of diverse origin, each carrying a multireplicon IncF plasmid encoding the gene blaCTX-M-15. The plasmid was eliminated from each isolate by displacement using an incompatible plasmid vector pMDP5_cureEC958. Whole-genome sequencing (WGS) was performed to obtain complete chromosome and plasmid sequences of wild-type isolates and to detect chromosomal mutations in plasmid-free strains. Competition assays were conducted to determine the relative fitness of plasmid-free clones compared to the corresponding wild-type isolates.

Results

We were able to successfully eliminate the IncF plasmids from all of the wild-type strains using the curing vector pMDP5_cureEC958. The chromosomes of plasmid-free clones contained zero to six point mutations. Plasmid-free strains of three isolates showed no significant difference in relative fitness compared to the corresponding plasmid-free strains. In the two remaining isolates, the plasmids produced a small but significant fitness cost.

Conclusion

We conclude that IncF plasmids produce moderate fitness effects in their E. coli ST131 H30Rx hosts. This fitness compatibility is likely to promote the maintenance of antibiotic resistance in this worrisome E. coli lineage.
In Vivo Multi-Day Calcium Imaging of CA1 Hippocampus in Freely Moving Rats Reveals a High Preponderance of Place Cells with Consistent Place Fields
Authors: Wirtshafter Hannah S , Disterhoft John F
Published: August 2021

Calcium imaging using GCaMP indicators and miniature microscopes has been used to image cellular populations during long timescales and in different task phases, as well as to determine neuronal circuit topology and organization. Because the hippocampus (HPC) is essential for tasks of memory, spatial navigation, and learning, calcium imaging of large populations of HPC neurons can provide new insight on cell changes over time during these tasks. All reported HPC in vivo calcium imaging experiments have been done in mouse. However, rats have many behavioral and physiological experimental advantages over mice. In this paper, we present the first (to our knowledge) in vivo calcium imaging from CA1 hippocampus in freely moving male rats. Using the UCLA Miniscope, we demonstrate that, in rat, hundreds of cells can be visualized and held across weeks. We show that calcium events in these cells are highly correlated with periods of movement, with few calcium events occurring during periods without movement. We additionally show that an extremely large percent of cells recorded during a navigational task are place cells (77.3±5.0%, surpassing the percent seen during mouse calcium imaging), and that these cells enable accurate decoding of animal position and can be held over days with consistent place fields in a consistent spatial map. A detailed protocol is included, and implications of these advancements on in vivo imaging and place field literature are discussed.

Significance statement

In vivo calcium imaging in freely moving animals allows the visualization of cellular activity across days. In this paper, we present the first in vivo Ca2+ recording from CA1 hippocampus in freely moving rats. We demonstrate that hundreds of cells can be visualized and held across weeks, and that calcium activity corresponds to periods of movement. We show that a high percentage (77.3±5.0%) of imaged cells are place cells, and that these place cells enable accurate decoding and can be held stably over days with little change in field location. Because the hippocampus is essential for many tasks involving memory, navigation, and learning, imaging of large populations of HPC neurons can shed new insight on cellular activity changes and organization.
Distinct neural circuits establish the same chemosensory behavior in C. elegans
Authors: Banerjee Navonil , Shih Pei-Yin , Rojas Palato Elisa J. , Sternberg Paul W. , Hallem Elissa A.
Published: August 2021

Animals frequently exhibit the same behavior under different environmental or physiological conditions. To what extent these behaviors are generated by similar vs. distinct mechanisms is unclear. Moreover, the circumstances under which divergent neural mechanisms establish the same behavior, and the molecular signals that regulate the same behavior across conditions, are poorly understood. We show that in C. elegans, distinct neural mechanisms mediate the same chemosensory behavior at two different life stages. Both dauer larvae and starved adults are attracted to carbon dioxide (CO2), but CO2 attraction is mediated by distinct sets of interneurons at the two life stages. Some interneurons mediate CO2 response only in dauers, some show CO2-evoked activity in adults and dauers but contribute to CO2 response only in adults, and some show CO2-evoked activity that opposes CO2 attraction in adults but promotes CO2 attraction in dauers. We also identify a novel role for insulin signaling in establishing life-stage-specific CO2 responses by modulating interneuron activity. Further, we show that a combinatorial code of both shared and life-stage-specific molecular signals regulate CO2 attraction. Our results identify a mechanism by which the same chemosensory behavior can be generated by distinct neural circuits, revealing an unexpected complexity to chemosensory processing.
Targeting interferon-λ signaling promotes recovery from central nervous system autoimmunity
Authors: Manivasagam Sindhu , Williams Jessica L. , Vollmer Lauren L. , Bollman Bryan , Bartleson Juliet M. , Ai Shenjian , Wu Gregory F. , Klein Robyn S.
Published: August 2021

Type III interferons (IFNLs) are newly discovered cytokines, acting at epithelial and other barriers, that exert immunomodulatory functions in addition to their primary roles in antiviral defense. Here we define a role for IFNLs in maintaining autoreactive T cell effector function and limiting recovery in a murine model of multiple sclerosis (MS), experimental autoimmune encephalomyelitis (EAE). Genetic or antibody-based neutralization of the IFNL receptor (IFNLR) resulted in lack of disease maintenance during EAE, with loss of CNS Th1 effector responses and limited axonal injury. Phenotypic effects of IFNLR signaling were traced to increased antigen presenting cell (APC) function, with associated increase in T cell production of IFNγ and GM-CSF. Consistent with this, IFNL levels within lesions of CNS tissues derived from MS patients were elevated compared to MS normal appearing white matter (NAWM). Furthermore, expression of IFNLR was selectively elevated in MS active lesions compared to inactive lesions or NAWM. These findings suggest IFNL signaling as a potential therapeutic target to prevent chronic autoimmune neuroinflammation.