bluuebunny/crossref_metadata_2025 huggingface dataset:
Rain attenuation in millimeter wave, centimeter wave and visible light ranges
Authors: Kuptsov V D , Ivanov S I , Fedotov A A , Badenko V L
Published: February 2021

The paper presents the results of theoretical simulation of mmWave, cmWave and visible light attenuation in rain based on the Mie scattering theory. Specific rain attenuation has been estimated from the gamma drop size distribution for a spherical drop. Rain attenuation of electromagnetic waves in the visible range, used by video cameras and lidars of «smart» city vehicles, and at the beginning of the millimeter wave range used by radars and positioning systems, have similar values averaging 3-5 dB/km. The attenuation levels of electromagnetic waves in mmWave, cmWave and Visible light ranges must be taken into account when calculating the energy budget of vehicle communications.
Improving cell seeding efficiency through modification of fiber geometry in 3D printed scaffolds
Authors: Mainardi Valerio Luca , Arrigoni Chiara , Bianchi Elena , Talò Giuseppe , Delcogliano Marco , Candrian Christian , Dubini Gabriele , Levi Marinella , Moretti Matteo
Published: February 2021

Cell seeding on 3D scaffolds is a very delicate step in tissue engineering applications, influencing the outcome of the subsequent culture phase, and determining the results of the entire experiment. Thus, it is crucial to maximize its efficiency. To this purpose, a detailed study of the influence of the geometry of the scaffold fibers on dynamic seeding efficiency is presented. 3D printing technology was used to realize polylactic acid porous scaffolds, formed by fibers with a non-circular cross-sectional geometry, named multilobed to highlight the presence of niches and ridges. An oscillating perfusion bioreactor was used to perform bidirectional dynamic seeding of MG63 cells. The fiber shape influences the fluid dynamic parameters of the flow, affecting values of fluid velocity and wall shear stress. The path followed by cells through the scaffold fibers is also affected and results in a larger number of adhered cells in multilobed scaffolds compared to scaffolds with standard pseudo cylindrical fibers. Geometrical and fluid dynamic features can also have an influence on the morphology of adhered cells. The obtained results suggest that the reciprocal influence of geometrical and fluid dynamic features and their combined effect on cell trajectories should be considered to improve the dynamic seeding efficiency when designing scaffold architecture.
Simplified ARCHITECT microfluidic chip through a dual-flip strategy enables stable and versatile tumoroid formation combined with label-free quantitative proteomic analysis
Authors: Feng Danni , Lv Junwei , Abdulla Aynur , Xu Jianwei , Sang Xiao , Wang Liping , Liu Wenjia , Lou Jiatao , Bo Zhao , Ding Xianting
Published: February 2021

Recent years, microfluidic three-dimensional (3D) tumor culture technique has made great progress in tumor microenvironment simulation and drug screening. Meanwhile, as their functionality and complexity increase, it is more difficult for current chip models to selectively collect specific-layer cells from tumoroids for further analysis. Moreover, a simplified and robust method for tumoroid formation with highly consistent size and repeatable 3D morphology is relatively ncessary. Here, we report an ARCHITECT (ARtificial CHIp for Tumor Enables Confocal Topography observation) chip, through a dual-flip strategy to implement straightforward tumoroid establishment. This platform guarantees stable batch-to-batch tumoroids formation and allows high resolution confocal imaging. Moreover, an initial cell density as low as 65 cells per chamber is efficient to deliver a tumoroid. With this ARCHITECT chip, different-layer cells of interest could be collected from tumoroid for label-free quantitative (LFQ) proteomic analysis. For application demonstration, we mainly verified this platform for lung carcinoma (A549) tumoroid construction and proteomic analysis at out layer. Our data indicate that the out-layer cells of A549 tumoroid show extensively distinct proteomic expressions compared to two-dimensional cultured A549 cells. The up-regulated proteins are mainly related to tumorigenicity, proliferation and metastasis. And the differentially expressed proteins are mainly relevant to lipid metabolism pathway which is essential to tumor progression and proliferation. This platform provides a simplified yet robust technique to connect microfluidic tumoroid construction and LFQ proteomic analysis. The simplicity of this technique should open the way to numerous applications such as discovering the innovative targets for cancer treatment, and studying the mophological and proteomic heterogeneity of different-layer cells across the tumoroid.
Experimentally optimizing QKD rates via nonlocal dispersion compensation
Authors: Neumann Sebastian Philipp , Ribezzo Domenico , Bohmann Martin , Ursin Rupert
Published: February 2021

Quantum key distribution (QKD) enables unconditionally secure communication guaranteed by the laws of physics. The last decades have seen tremendous efforts in making this technology feasible under real-life conditions, with implementations bridging ever longer distances and creating ever higher secure key rates. Readily deployed glass fiber connections are a natural choice for distributing the single photons necessary for QKD both in intra- and intercity links. Any fiber-based implementation however experiences chromatic dispersion which deteriorates temporal detection precision. This ultimately limits maximum distance and achievable key rate of such QKD systems. In this work, we address this limitation to both maximum distance and key rate and present an effective and easy-to-implement method to overcome chromatic dispersion effects. By exploiting entangled photons’ frequency correlations, we make use of nonlocal dispersion compensation to improve the photons’ temporal correlations. Our experiment is the first implementation utilizing the inherently quantum-mechanical effect of nonlocal dispersion compensation for QKD in this way. We experimentally show an increase in key rate from 6.1 to 228.3 bits/s over 6.46 km of telecom fiber. Our approach is extendable to arbitrary fiber lengths and dispersion values, resulting in substantially increased key rates and even enabling QKD in the first place where strong dispersion would otherwise frustrate key extraction at all.
Machine learning pipeline for quantum state estimation with incomplete measurements
Authors: Danaci Onur , Lohani Sanjaya , Kirby Brian T , Glasser Ryan T
Published: February 2021

Two-qubit systems typically employ 36 projective measurements for high-fidelity tomographic estimation. The overcomplete nature of the 36 measurements suggests possible robustness of the estimation procedure to missing measurements. In this paper, we explore the resilience of machine-learning-based quantum state estimation techniques to missing measurements by creating a pipeline of stacked machine learning models for imputation, denoising, and state estimation. When applied to simulated noiseless and noisy projective measurement data for both pure and mixed states, we demonstrate quantum state estimation from partial measurement results that outperforms previously developed machine-learning-based methods in reconstruction fidelity and several conventional methods in terms of resource scaling. Notably, our developed model does not require training a separate model for each missing measurement, making it potentially applicable to quantum state estimation of large quantum systems where preprocessing is computationally infeasible due to the exponential scaling of quantum system dimension.
Reproductive state influences the degree of risk tolerance for a seasonally breeding mesopredator
Authors: Marneweck Courtney J , van Schalkwyk O Louis , Marneweck David G , Beverley Grant , Davies-Mostert Harriet T , Parker Daniel M
Published: February 2021

The risk of predation can alter the way animals perceive costs and benefits in their environment, on which foraging decisions are made. To maximize fitness, animals with offspring show the most pronounced alteration in behavior because mothers experience increased nutritional requirements and increased vulnerability to predation. Therefore, the tolerance of risk is shaped, in part, by reproductive state. Like prey species, mesopredators balance a trade-off between food and predation to maximize fitness. However, few studies have acknowledged its importance. We investigated how mesopredators may alter their space use between periods when young are and are not vulnerable. Investigating the fine-scale space use of 19 packs of African wild dogs Lycaon pictus in the Kruger National Park, we found lower risk tolerance of denning packs; they re-visited area less frequently as lion and impala density increased and thus reduced the likelihood of risky encounters by avoiding areas where both risk and reward were high. By contrast, non-denning packs re-visited area less frequently as lion density increased and impala density decreased and thus avoided areas where reward was low, especially if risk was high. These results suggest that wild dogs shift their patterns of space use when the pack is most vulnerable. Ultimately, we found evidence of decreased risk tolerance by denning packs, likely because of increased vulnerability of lactating mothers and immobile pups. More broadly, our findings suggest that risk tolerance is dependent on reproductive state for mesopredators and should be considered as a possible mechanism for other mesopredators as well.
PPIT: an R package for inferring microbial taxonomy from nifH sequences
Authors: Kapili Bennett J , Dekas Anne E
Published: February 2021

Motivation

Linking microbial community members to their ecological functions is a central goal of environmental microbiology. When assigned taxonomy, amplicon sequences of metabolic marker genes can suggest such links, thereby offering an overview of the phylogenetic structure underpinning particular ecosystem functions. However, inferring microbial taxonomy from metabolic marker gene sequences remains a challenge, particularly for the frequently sequenced nitrogen fixation marker gene, nitrogenase reductase (nifH). Horizontal gene transfer in recent nifH evolutionary history can confound taxonomic inferences drawn from the pairwise identity methods used in existing software. Other methods for inferring taxonomy are not standardized and require manual inspection that is difficult to scale.

Results

We present Phylogenetic Placement for Inferring Taxonomy (PPIT), an R package that infers microbial taxonomy from nifH amplicons using both phylogenetic and sequence identity approaches. After users place query sequences on a reference nifH gene tree provided by PPIT (n = 6317 full-length nifH sequences), PPIT searches the phylogenetic neighborhood of each query sequence and attempts to infer microbial taxonomy. An inference is drawn only if references in the phylogenetic neighborhood are: (1) taxonomically consistent and (2) share sufficient pairwise identity with the query, thereby avoiding erroneous inferences due to known horizontal gene transfer events. We find that PPIT returns a higher proportion of correct taxonomic inferences than BLAST-based approaches at the cost of fewer total inferences. We demonstrate PPIT on deep-sea sediment and find that Deltaproteobacteria are the most abundant potential diazotrophs. Using this dataset, we show that emending PPIT inferences based on visual inspection of query sequence placement can achieve taxonomic inferences for nearly all sequences in a query set. We additionally discuss how users can apply PPIT to the analysis of other marker genes.

Availability and implementation

PPIT is freely available to noncommercial users at https://github.com/bkapili/ppit. Installation includes a vignette that demonstrates package use and reproduces the nifH amplicon analysis discussed here. The raw nifH amplicon sequence data have been deposited in the GenBank, EMBL and DDBJ databases under BioProject number PRJEB37167.

Supplementary information

Supplementary data are available at Bioinformatics online.
Management of complex ventral hernias: results of an international survey
Authors: Knaapen L , Buyne O , Slater N , Matthews B , Goor H , Rosman C
Published: February 2021

Background

The surgical treatment of patients with complex ventral hernias is challenging. The aim of this study was to present an international overview of expert opinions on current practice.

Methods

A survey questionnaire was designed to investigate preoperative risk management, surgical approach and mesh choice in patients undergoing complex hernias repair, and treatment strategies for infected meshes. Geographical location of practice, experience and annual volumes of the surgeons were compared.

Results

Of 408 surgeons, 234 (57.4 per cent) were practising in the USA, 116 (28.4 per cent) in Europe, and 58 (14.2 per cent) in other countries. Some 412 of 418 surgeons (98.6 per cent) performed open repair and 322 of 416 (77.4 per cent) performed laparoscopic repair. Most recommended preoperative work-up/lifestyle changes such as smoking cessation (319 of 398, 80.2 per cent) and weight loss (254 of 399, 63.7 per cent), but the consequences of these strategies varied. American surgeons and less experienced surgeons were stricter. Antibiotics were given at least 1 h before surgery by 295 of 414 respondents (71.3 per cent). Synthetic and biological meshes were used equally in contaminated primary hernia repair, whereas for recurrent hernia repair synthetic mesh was used in a clean environment and biological or no mesh in a contaminated environment. American surgeons and surgeons with less experience preferred biological mesh in contaminated environments significantly more often. Percutaneous drainage and antibiotics were the first steps recommended in treating mesh infection. In the presence of sepsis, most surgeons favoured synthetic mesh explantation and further repair with biological mesh.

Conclusion

There remains a paucity of good-quality evidence in dealing with these hernias, leading to variations in management. Patient optimization and issues related to mesh choice and infections require well designed prospective studies.
Tetanus in a rural low-income intensive care unit setting
Authors: Olum Sam , Eyul Jacob , Lukwiya Daniel Ocen , Scolding Neil
Published: February 2021

Tetanus is a potentially severe but preventable infection. In resource-rich settings, vaccination programmes have reduced tetanus to a rare disease, though still carrying an overall mortality of some 13%. However, in low-income settings, tetanus remains common, and is a significant cause of mortality—though major World Health Organisation programmes are successfully targeting neonatal and maternal disease. Data concerning the frequency and outcomes of non-neonatal tetanus in low-income settings are very sparse. We aimed to utilize a unique intensive care unit-based dataset to elicit clinical and demographic features and mortality in a large cohort of tetanus patients admitted over an eleven-year period to a single hospital centre in a rural low-income setting in northern Uganda. A total of 268 patients with tetanus were admitted to the Intensive Care Unit at St Mary’s Hospital, Lacor between 2005 and 2015; the records of 190 were retrievable and had sufficient information to be assessed. 29 were neonates (median age 7 days, IQR 0), 52 children (1–16yrs; median age 11 years, IQR 4.5) and 109 were adults (median age 42 years, IQR 23). There was no seasonal pattern in the frequency of admissions. Of the 190 patients, 69 had endotracheal intubation with intermitent positive pressure ventilation, and 57 patients had central line placement. The overall mortality was 51.5–72.4% in neonatal disease, 25% in children and 57.8% in adults. The requirements for neither central line insertion, nor endotracheal intubation, nor intermittent positive pressure ventilation were independently linked to mortality rates. By contrast with neonatal and childhood disease, there was a marked male preponderance in adult tetanus—94 males and 15 females (gender difference P < 0.001)—and although year-on-year breakdown suggested no obvious upward or downward trend over the span of our study in total numbers of tetanus admissions, a trend towards an increasing incidence of adult tetanus was apparent.These findings confirm that adult tetanus remains a major problem in rural low-income settings, particularly in males, and suggests that more resources should be devoted to vaccination programmes targeting men.
Toward a Theoretical Framework of Relational Maintenance in Computer-Mediated Communication
Authors: Mason Adam J , Carr Caleb T
Published: February 2021

This article addresses the need for theoretical frameworks from which to advance the study of interpersonal relational maintenance in computer-mediated communication (CMC). We suggest one way to satisfy this need is to extend and adapt extant theories of offline relational maintenance to mediated interactions by addressing how CMC is likely integrated to sustain the underlying processes of human interaction in newer channels. Social penetration theory (SPT) is used to illustrate the process proposed. The building blocks of SPT—self-disclosure, reciprocal exchange, and the effect of environmental and situational contexts on interpersonal interactions—are still considered vital in sustaining relationships, even online. By considering how these components are affected by the idiosyncrasies of computer mediation, this work provides a path toward consistent, theoretically-driven research regarding the maintenance of relationships via CMC, and also exemplifies how scholars may forge additional avenues for such research.
Decrease of physical fitness during neoadjuvant chemoradiotherapy predicts the risk of pneumonia after esophagectomy
Authors: Bor P , Kingma B F , Kerst A , Steenhagen E , Ruurda J P , van Hillegersberg R , Valkenet K , Veenhof C
Published: February 2021

Although neoadjuvant chemoradiotherapy (nCRT) is frequently used in esophageal cancer patients undergoing treatment with curative intent, it can negatively impact patients’ physical fitness. A decline in physical fitness during chemoradiotherapy may be an indication of vulnerability. The aim of this study was to evaluate whether changes in physical fitness, weight, and fat-free mass index (FFMI) during nCRT can predict the risk of postoperative pneumonia. A retrospective longitudinal observational cohort study was performed in patients who received curative treatment for esophageal cancer between September 2016 and September 2018 in a high-volume center for esophageal cancer surgery. Physical fitness (handgrip strength, leg extension strength, and exercise capacity), weight, and FFMI were measured before and after chemoradiotherapy. To be included in the data analyses, pre- and post-nCRT data had to be available of at least one of the outcome measures. Logistic regression analyses were performed to evaluate the predictive value of changes in physical fitness, weight, and FFMI during nCRT on postoperative pneumonia, as defined by the Uniform Pneumonia Scale. In total, 91 patients were included in the data analyses. Significant associations were found between the changes in handgrip strength (odds ratio [OR] 0.880, 95% confidence interval [CI]: 0.813–0.952) and exercise capacity (OR 0.939, 95%CI: 0.887–0.993) and the occurrence of postoperative pneumonia. All pneumonias occurred in patients with declines in handgrip strength and exercise capacity after nCRT. A decrease of handgrip strength and exercise capacity during nCRT predicts the risk of pneumonia after esophagectomy for cancer. Measuring physical fitness before and after chemoradiotherapy seems an adequate method to identify patients at risk of postoperative pneumonia.
The 2020 ESC-ACVC quality indicators for the management of acute myocardial infarction applied to the FAST-MI registries
Authors: Schiele François , Gale Chris P , Simon Tabassome , Fox Keith A A , Bueno Hector , Lettino Maddalena , Tubaro Marco , Puymirat Etienne , Ferrières Jean , Ecarnot Fiona , Danchin Nicolas , Meneveau Nicolas
Published: February 2021

Aims

We estimated the 2020 European Society of Cardiology-Acute Cardio Vascular Care (ESC-ACVC) quality indicators (QI) for the management of acute myocardial infarction, from three existing registries to determine the feasibility of assessment, room for improvement, association with outcomes, and suitability for centre benchmarking.

Methods and results

Data were extracted from three French nationwide registries, namely FAST-MI 2005, 2010, and 2015. Feasibility of assessment and room for improvement were estimated by the denominator (patients in whom QI could be measured) and numerator (patients who satisfied the QI, among those eligible). Associations between composite QIs (CQIs) and mortality were assessed by multivariate analysis. Centre benchmarking was based on the centres mean CQI, vs. the national mean. The 2020 QIs were measured in 12 660/13 130 patients from FAST-MI. Measurement feasibility ranged from 15% to 100% with greater potential for implementation with the 2020 QI set. The mean (±SD) value of the opportunity-based CQI was 0.72 ± 0.01 and attainment of the all-or-none CQI 8.5%. Both CQIs were associated with adjusted 1-year mortality. Centre categorization into low, intermediate, and high quality was feasible, and distinguished centres with differing mortality.

Conclusion

Most of the 2020 QI can be measured from existing registries in all domains but not in the patient’s satisfaction domain. This assessment shows potential for implementation. Both CQIs were inversely associated with one-year mortality and centre benchmarking was feasible.
Sex differences in mortality and 90-day readmission rates after transcatheter aortic valve replacement: a nationwide analysis from the USA
Authors: Pajjuru Venkata S , Thandra Abhishek , Guddeti Raviteja R , Walters Ryan W , Jhand Aravdeep , Andukuri Venkata G , Alkhouli Mohamad , Spertus John A , Alla Venkata M
Published: February 2021

Aims

To assess gender differences in in-hospital mortality and 90-day readmission rates among patients undergoing transcatheter aortic valve replacement (TAVR) in the USA.

Methods and results

Hospitalizations for TAVR were retrospectively identified in the National readmissions database (NRD) from 2012 to 2017. Gender based differences in in-hospital mortality and 90-day readmissions were explored using multivariable logistic regression models. During the study period, an estimated 171 361 hospitalizations for TAVR were identified, including 79 722 (46.5%) procedures in women and 91 639 (53.5%) in men. Unadjusted in-hospital mortality and 90-day all-cause readmissions were significantly higher for women compared with men (2.7% vs. 2.3%, P = 0.002; 25.1% vs. 24.1%, P = 0.012, respectively). After adjusting for baseline characteristics, women had 13% greater adjusted odds of in-hospital mortality [adjusted odds ratio (aOR): 1.13, 95% confidence interval (CI): 1.02–1.26, P = 0.017], and 9% greater adjusted odds of 90-day readmission compared with men (aOR: 1.09, 95% CI: 1.05–1.14, P < 0.001). During the study period, there was a steady decrease in-hospital mortality (5.3% in 2012 to 1.6% in 2017; Ptrend < 0.001) and 90-day (29.9% in 2012 to 21.7% in 2017; Ptrend < 0.001) readmission rate in both genders.

Conclusion

In-hospital mortality and readmission rates for TAVR hospitalizations have decreased over time across both genders. Despite these improvements, women undergoing TAVR continue to have a modestly higher in-hospital mortality, and 90-day readmission rates compared with men. Given the expanding indications and use of TAVR, further research is necessary to identify the reasons for this persistent gap and design appropriate interventions.
Atlantic ’45: Gaels, Indians and the Origins of Imperial Reform in the British Atlantic
Authors: Fisher Samuel K
Published: February 2021

This article offers a new explanation of the origins of imperial reform in the eighteenth-century British Atlantic. It does so by arguing that the efforts of Gaelic Jacobites in Ireland and Scotland, along with those of Native diplomats in North America, should be viewed as similar attempts to reshape the British empire by recourse to the French—and that in the period 1745–8 these attempts bore fruit. By comparing the efforts of imperial officials to cope with the Jacobite rising of 1745 and their failures in Indian diplomacy during the same period, the article posits the existence of an ‘Atlantic ’45’, a shared crisis of diversity that prompted calls for imperial reform and shaped the way it played out in Scotland, North America and Ireland. As they struggled to repress the rebellion and win over Indian allies, imperial officials found that they could not gain control of Gaelic and Indian peoples without also gaining more control over their provincial subjects, an insight that lay at the heart of reform thinking for the rest of the century and put the empire on a collision course with provincial subjects’ sense of what it meant to be British. By acknowledging the centrality of diversity and the important contributions of Gaelic and Indian peoples, the article offers a new way of understanding imperial reform and revolution, one that includes a richer and more complex cast and gives more purchase on the different trajectories of Ireland, Scotland, and North America both within and outside empire.
Long-term results of tricuspid annuloplasty with 3-dimensional-shaped rings: effective and durable!
Authors: Carino Davide , Zancanaro Edoardo , Lapenna Elisabetta , Ruggeri Stefania , Denti Paolo , Iaci Giuseppe , Buzzatti Nicola , Calabrese Maria Chiara , Nascimbene Simona , Sala Alessandra , Castiglioni Alessandro , Alfieri Ottavio , De Bonis Michele
Published: February 2021

OBJECTIVES

3-Dimensional (3D)-shaped rings are largely adopted for tricuspid annuloplasty, but evidence about their long-term results is scanty. The goal of this study was to analyse the long-term results of tricuspid annuloplasty with 3D-shaped rings.

MATERIALS AND METHODS

A retrospective review of our prospectively maintained database was carried out to identify all patients who underwent tricuspid valve repair with 3D-shaped rings between January 2011 and December 2014. Kaplan–Meier methods were used to analyse long-term survival. Cumulative incidence function using death as the competitive outcome was used to estimate cardiac death.

RESULTS

A total of 168 patients were identified. The median age was 66 years. Eighty-two patients (49%) were in advanced New York Heart Association functional class III–IV. Atrial fibrillation (AF) was present in 101 (60%); the median ejection fraction was 60%. In 82 (49%) patients, a Medtronic 3D Contour annuloplasty ring was employed; in the remaining 86 (51%) patients, an Edwards MC3 ring was used. Cumulative incidence function of cardiac death, with non-cardiac death as a competing risk, was 1.9 ± 1.1%, 95% confidence interval (CI) (0.51–4.95) at 7 years. The cumulative incidence function of recurrence of tricuspid regurgitation (TR) ≥2+ at 7 years was 14 ± 3.17%, 95% CI (8.49–20.82). Recurrence of TR ≥2+ at 7 years was not significantly different between the Medtronic 3D Contour and the Edwards MC3 rings (P = 0.3). AF was identified as the only independent predictor of recurrence of TR ≥2+.

CONCLUSIONS

3D-shaped rings are effective and durable. TR recurrence was relatively low at 7 years and usually moderate (2+/4+) without a significant difference between the 2 types of rings. The role of AF as a predictor of TR recurrence was confirmed.
Secondary chordal resection with septal myectomy for treatment of symptomatic obstructive hypertrophic cardiomyopathy
Authors: Ram Eilon , Schwammenthal Ehud , Kuperstein Rafael , Jamal Tamer , Nahum Eyal , Sternik Leonid , Raanani Ehud
Published: February 2021

OBJECTIVES

Left ventricular outflow tract obstruction causes symptoms of heart failure in most patients with hypertrophic cardiomyopathy. Resection of the secondary mitral valve (MV) chordae has recently been shown to move the MV apparatus posteriorly, thereby eradicating the outflow gradient. The aim of this study was to evaluate whether secondary chordal resection concomitant to septal myectomy improves outcomes.

METHODS

Between 2005 and 2020, a total of 165 patients underwent septal myectomy without MV repair or replacement in our Medical Center. Secondary MV chordal resection was performed in 60 patients, and their outcomes were compared with those of the remaining 105 patients who did not undergo chordal resection (controls). Mean age was 61 ± 13 and 58 ± 16 years, respectively (P = 0.205).

RESULTS

There were no in-hospital deaths throughout the entire cohort. Of those patients who underwent secondary chordal resection, New York Heart Association functional class decreased from 3 (interquartile range 2–3) preoperatively to 1 (interquartile range 1–2) postoperatively (P < 0.001), and resting outflow gradient decreased from 91 ± 39 mmHg to 13 ± 8 mmHg (86% change, P < 0.001). Compared with controls, patients who underwent secondary chordal resection had a significant lower resting outflow gradient at follow-up (14 ± 7 mmHg vs 21 ± 15 mmHg, P = 0.002). The rate of moderate or more than moderate mitral regurgitation at 5 years was 2% in the secondary chordal resection group and 5% in the controls (hazard ratio 1.05, confidence interval 0.11–10.32; P = 0.965).

CONCLUSIONS

In this observational study, we report that secondary chordal resection concomitant to septal myectomy for left ventricular outflow tract obstruction is safe, relieves heart failure symptoms and reduces left ventricular outflow tract gradient in appropriately selected patients.
Complex transcatheter aortic valve replacement in aortic regurgitation and transcatheter mitral annuloplasty in severe dextrocardia
Authors: Rudziński Piotr Nikodem , Mach Markus , Gross Christoph , Andreas Martin
Published: February 2021

A 70-year-old female with symptomatic severe native aortic regurgitation, acquired dextrocardia, moderate-to-severe secondary mitral regurgitation and prohibitive surgical risk was admitted for transcatheter aortic valve replacement. A balloon-expendable Sapien 3 Ultra valve was implanted successfully. After 6 months, the patient remained symptomatic due to the concomitant moderate-to-severe secondary mitral regurgitation. Transcatheter mitral valve repair using a Carillon Mitral Contour System was performed resulting in a significant reduction of mitral regurgitation and uneventful follow-up. Most importantly, other transcatheter repair techniques would not have been feasible due to the impossible transoesophageal echocardiography guidance. This is the first case of transcatheter aortic valve replacement in a patient with native aortic regurgitation, acquired dextrocardia and severe aortic annulus malrotation using a balloon-expendable valve. Moreover, it is the first transcatheter mitral valve repair procedure using Carillon device performed by a cardiac surgeon.
Does adding an aortic root replacement or sinus repair during arch repair increase postoperative mortality? Evidence from the Canadian Thoracic Aortic Collaborative
Authors: Hage Fadi , Hage Ali , Dagenais Francois , Cartier Andreanne , Ouzounian Maral , Chung Jennifer , El-Hamamsy Ismail , Chauvette Vincent , Peterson Mark D , Lachapelle Kevin , Ridwan Khalid , Boodhwani Munir , Guo Ming , Bozinovski John , Moon Michael C , White Abigail , Yamashita Michael , Lodewyks Carly , Atoui Rony , Payne Darrin , Chu Michael W A ,   the Canadian Thoracic Aortic Collaborative
Published: February 2021

OBJECTIVES

The aim of this study was to examine the effect of the addition of an aortic root replacement or sinus repair on mortality and morbidity during aortic arch repair.

METHODS

A total of 2472 patients underwent proximal or total aortic arch repair with hypothermic circulatory arrest between 2002 and 2018 at 12 centres. Multivariable logistic regressions (MV) and propensity score (PS) with inverse probability of treatment weighting (IPTW) analyses were performed.

RESULTS

A total of 1099 (44.5%) patients had additional aortic root replacement (n = 934) or sinus repair (n = 165). Those with aortic root interventions were younger (61 ± 13 vs 64 ± 13 years, P < 0.001) and had less females (23% vs 35%, P < 0.001), less dissection (31% vs 36%, P = 0.004), less urgent cases (35% vs 39%, P = 0.047), more connective tissue disease (7% vs 3%, P < 0.001) and less total arch replacements (14% vs 22%, P < 0.001). On adjusted analyses, the addition of aortic root procedure was associated with increased mortality [MV: odds ratio (OR) 1.41, 95% confidence interval (CI) 1.03–1.92; PS-IPTW: risk increased by 3.7%, 95% CI 1.2–6.3%, P = 0.004]. Reoperation for bleeding was also increased with the addition of aortic root intervention (MV: OR 1.48, 95% 1.10–1.99; PS-IPTW: risk increased by 3.2%, 95% CI 0.8–5.6%, P = 0.009). The risks of stroke and dialysis-dependent renal failure were similar. When looking only at non-elective cases, the increased risk of mortality was more pronounced (MV: OR 1.60, 95% CI 1.11–2.32, P = 0.013; PS-IPTW: risk increased by 6.8%, 95 CI 1.7–11.8%, P = 0.008, and a number need to harm of 15 patients to cause 1 additional death).

CONCLUSIONS

The addition of aortic root replacement or sinus repair during proximal or total aortic arch repair seems to increase postoperative mortality only in non-elective cases.
Pre-primary teacher talk: L1 use across different activity references
Authors: Aull Bethany
Published: February 2021

Whether and how instructor L1 use may enhance foreign language learning has been a topic of considerable discussion. Although numerous studies note the L1’s recurrence in teacher talk, research has tended either to quantify its overall use throughout whole class sessions or to outline specific functions. Consequently, little is known about teachers’ actual L1-versus-L2 distribution across different classroom activities. This article contemplates teacher references relating to two prominent activities: core references (focusing on target content) and logistical references (classroom management and organisation). Via word count, it contrasts L1 use in the core and logistical references of ten non-native EFL instructors of very young learners. The findings indicate significantly higher L1 quantities in logistical than core references, even in the case of comprehensible high-frequency logistical terms such as sit. This disparity raises questions about the role of activity-differential L1 use, and points to the particular value of logistics for focalized teacher-talk analysis and awareness.
Phylogenetic and metabolic diversity have contrasting effects on the ecological functioning of bacterial communities
Authors: Xenophontos Constantinos , Taubert Martin , Harpole W Stanley , Küsel Kirsten
Published: February 2021

Quantifying the relative contributions of microbial species to ecosystem functioning is challenging, because of the distinct mechanisms associated with microbial phylogenetic and metabolic diversity. We constructed bacterial communities with different diversity traits and employed exoenzyme activities (EEAs) and carbon acquisition potential (CAP) from substrates as proxies of bacterial functioning to test the independent effects of these two aspects of biodiversity. We expected that metabolic diversity, but not phylogenetic diversity would be associated with greater ecological function. Phylogenetically relatedness should intensify species interactions and coexistence, therefore amplifying the influence of metabolic diversity. We examined the effects of each diversity treatment using linear models, while controlling for the other, and found that phylogenetic diversity strongly influenced community functioning, positively and negatively. Metabolic diversity, however, exhibited negative or non-significant relationships with community functioning. When controlling for different substrates, EEAs increased along with phylogenetic diversity but decreased with metabolic diversity. The strength of diversity effects was related to substrate chemistry and the molecular mechanisms associated with each substrate's degradation. EEAs of phylogenetically similar groups were strongly affected by within-genus interactions. These results highlight the unique flexibility of microbial metabolic functions that must be considered in further ecological theory development.
The first sequencedSphaerotilus natansbacteriophage– characterization and potential to control its filamentous bacterium host
Authors: Ferreira Rute , Amado Rui , Padrão Jorge , Ferreira Vânia , Dias Nicolina M , Melo Luís D R , Santos Sílvio B , Nicolau Ana
Published: February 2021

Bacteriophages (phages) are ubiquitous entities present in every conceivable habitat as a result of their bacterial parasitism. Their prevalence and impact in the ecology of bacterial communities and their ability to control pathogens make their characterization essential, particularly of new phages, improving knowledge and potential application. The isolation and characterization of a new lytic phage against Sphaerotilus natans strain DSM 6575, named vB_SnaP-R1 (SnaR1), is here described. Besides being the first sequenced genome of a Sphaerotilus natans infecting phage, 99% of its 41507 bp genome lacks homology with any other sequenced phage, revealing its uniqueness and previous lack of knowledge. Moreover, SnaR1 is the first Podoviridae phage described infecting this bacterium. Sphaerotilus natans is an important filamentous bacterium due to its deleterious effect on wastewater treatment plants (WWTP) and thus, phages may play a role as novel biotechnological tools against filamentous overgrowth in WWTP. The lytic spectrum of SnaR1 was restricted to its host strain, infecting only one out of three S. natans strains and infection assays revealed its ability to reduce bacterial loads. Results suggest SnaR1 as the prototype of a new phage genus and demonstrates its potential as a non-chemical alternative to reduce S. natans DSM 6575 cells.
Root exposure to apple replant disease soil triggers local defense response and rhizoplane microbiome dysbiosis
Authors: Balbín-Suárez Alicia , Jacquiod Samuel , Rohr Annmarie-Deetja , Liu Benye , Flachowsky Henryk , Winkelmann Traud , Beerhues Ludger , Nesme Joseph , J. Sørensen Søren , Vetterlein Doris , Smalla Kornelia
Published: February 2021

A soil column split-root experiment was designed to investigate the ability of apple replant disease (ARD)-causing agents to spread in soil. ‘M26’ apple rootstocks grew into a top layer of Control soil, followed by a barrier-free split-soil layer (Control soil/ARD soil). We observed a severely reduced root growth, concomitant with enhanced gene expression of phytoalexin biosynthetic genes and phytoalexin content in roots from ARD soil, indicating a pronounced local plant defense response. Amplicon sequencing (bacteria, archaea, fungi) revealed local shifts in diversity and composition of microorganisms in the rhizoplane of roots from ARD soil. An enrichment of operational taxonomic units affiliated to potential ARD fungal pathogens (Ilyonectria and Nectria sp.) and bacteria frequently associated with ARD (Streptomyces, Variovorax) was noted. In conclusion, our integrated study supports the idea of ARD being local and not spreading into surrounding soil, as only the roots in ARD soil were affected in terms of growth, phytoalexin biosynthetic gene expression, phytoalexin production and altered microbiome structure. This study further reinforces the microbiological nature of ARD, being likely triggered by a disturbed soil microbiome enriched with low mobility of the ARD-causing agents that induce a strong plant defense and rhizoplane microbiome dysbiosis, concurring with root damage.
Transcriptomic analysis of gonadal development in parasitic and non-parasitic lampreys (Ichthyomyzonspp.), with a comparison of genomic resources in these non-model species
Authors: Ajmani Nisha , Yasmin Tamanna , Docker Margaret F , Good Sara V
Published: February 2021

Lampreys are jawless fishes that diverged ∼550 million years ago from other vertebrates. Sequencing of the somatic and the germline genomes of the sea lamprey (Petromyzon marinus) in 2013 and 2018, respectively, has helped to improve our understanding of the genes and gene networks that control many aspects of lamprey development. However, little is known about the genetic basis of gonadal differentiation in lampreys, partly due to the prolonged period during which their gonads remain sexually indeterminate. We performed RNA-sequencing on gonadal samples from four chestnut lamprey (Ichthyomyzon castaneus) and six northern brook lamprey (I. fossor) to identify differentially expressed genes (DEG’s) and pathways associated with transcriptomic differences in: (1) larvae during early gonadal differentiation versus definitive females (i.e., with oocytes in the slow cytoplasmic growth phase); and (2) females versus definitive males undergoing spermatogonial proliferation. We compared the mapping percentages of these transcriptomes to the two available sea lamprey reference genomes and three annotation files (Ensembl and UCSC for the somatic genome and SIMRbase for the germline genome). We found that mapping the RNA-seq reads to the germline genome gave superior results and, using Trinotate, we provided new putative annotations for 8161 genes in the somatic assembly and 880 genes for the germline assembly. We identified >2000 DEG’s between stages and sexes, as well as biological pathways associated with each. Interestingly, some of the upregulated genes (e.g., DEG’s associated with spermiation) suggest that changes in gene expression can precede morphological changes by several months. In contrast, only 81 DEG’s were evident between the chestnut lamprey (that remains sexually immature during an extended post-metamorphic parasitic feeding phase) and the nonparasitic northern brook lamprey (that undergoes sexual maturation near the end of metamorphosis), but few replicates were available for comparable stages and sexes. This work lays the foundation for identifying and confirming the orthology and the function of genes involved in gonadal development in these and other lamprey species across more developmental stages.
Genetic interactions regulate hypoxia tolerance conferred by activating Notch in excitatory amino acid transporter 1-positive glial cells inDrosophila melanogaster
Authors: Zhou Dan , Stobdan Tsering , Visk DeeAnn , Xue Jin , Haddad Gabriel G
Published: February 2021

Hypoxia is a critical pathological element in many human diseases, including ischemic stroke, myocardial infarction, and solid tumors. Of particular significance and interest of ours are the cellular and molecular mechanisms that underlie susceptibility or tolerance to low O2. Previous studies have demonstrated that Notch signaling pathway regulates hypoxia tolerance in both Drosophila melanogaster and humans. However, the mechanisms mediating Notch-conferred hypoxia tolerance are largely unknown. In this study, we delineate the evolutionarily conserved mechanisms underlying this hypoxia tolerant phenotype. We determined the role of a group of conserved genes that were obtained from a comparative genomic analysis of hypoxia-tolerant D.melanogaster populations and human highlanders living at the high-altitude regions of the world (Tibetans, Ethiopians, and Andeans). We developed a novel dual-UAS/Gal4 system that allows us to activate Notch signaling in the Eaat1-positive glial cells, which remarkably enhances hypoxia tolerance in D.melanogaster, and, simultaneously, knock down a candidate gene in the same set of glial cells. Using this system, we discovered that the interactions between Notch signaling and bnl (fibroblast growth factor), croc (forkhead transcription factor C), or Mkk4 (mitogen-activated protein kinase kinase 4) are important for hypoxia tolerance, at least in part, through regulating neuronal development and survival under hypoxic conditions. Becausethese genetic mechanisms are evolutionarily conserved, this group of genes may serve as novel targets for developing therapeutic strategies and have a strong potential to be translated to humans to treat/prevent hypoxia-related diseases.
A Genetic Screen to Identify Components of the sina Signaling Pathway in Drosophila Eye Development
Authors: Neufeld Thomas P , Tang Amy H , Rubin Gerald M
Published: February 2021

Specification of the R7 photoreceptor cell in the developing Drosophila eye requires the seven in absentia (sina) gene. We demonstrate that ectopic expression of sina in all cells behind the morphogenetic furrow disrupts normal eye development during pupation, resulting in a severely disorganized adult eye. Earlier events of cell fate specification appear unaffected. A genetic screen for dominant enhancers and suppressors of this phenotype identified mutations in a number of genes required for normal eye development, including UbcD1, which encodes a ubiquitin conjugating enzyme; SR3-4a, a gene previously implicated in signaling downstream of Ras1; and a Drosophila homolog of the Sin3A transcriptional repressor.
Age-Specific Properties of Spontaneous Mutations Affecting Mortality in Drosophila melanogaster
Authors: Pletcher Scott D , Houle David , Curtsinger James W
Published: February 2021

An analysis of the effects of spontaneous mutations affecting age-specific mortality was conducted using 29 lines of Drosophila melanogaster that had accumulated spontaneous mutations for 19 generations. Divergence among the lines was used to estimate the mutational variance for weekly mortality rates and the covariance between weekly mortality rates at different ages. Significant mutational variance was observed in both males and females early in life (up to ~30 days of age). Mutational variance was not significantly different from zero for mortality rates at older ages. Mutational correlations between ages separated by 1 or 2 wk were generally positive, but they declined monotonically with increasing separation such that mutational effects on early-age mortality were uncorrelated with effects at later ages. Analyses of individual lines revealed several instances of mutation-induced changes in mortality over a limited range of ages. Significant age-specific effects of mutations were identified in early and middle ages, but surprisingly, mortality rates at older ages were essentially unaffected by the accumulation procedure. Our results provide strong evidence for the existence of a class of polygenic mutations that affect mortality rates on an age-specific basis. The patterns of mutational effects measured here relate directly to recently published estimates of standing genetic variance for mortality in Drosophila, and they support mutation accumulation as a viable mechanism for the evolution of senescence.