bluuebunny/crossref_metadata_2025 huggingface dataset:
Meshless approach based on MLS with additional constraints for large deformation analysis
Authors: El Kadmiri R. , Belaasilia Y. , Timesli A. , Kadiri M. S.
Published: January 2021

In the present work, we are interested to develop a meshless approach, based on the strong form MLS approximation with additional constraints, to solve the nonlinear elastic and elsto-plastic problems for regular and irregular distribution of points. We adopt a plastic behavior law based on the total deformation theory, which is very convenient when the physical nonlinearity is more important than the effect of irreversible process and the loading history. In plasticity, one encounters discontinuities of rigidity where the application of asymptotic developments seems difficult or impossible. To apply the Taylor series expansion, regularization methods have been adapted. The strong form MLS approximation allows us to avoid the inconvenient of the numerical integration, while the asymptotic developments help us to reduce the computation cost observed in the incremental law of plasticity and the iterative methods. For irregular points distribution, we can get an ill-posed least squares problems due to a singular moment matrix of MLS approximation. To avoid this difficulty, we propose a modified MLS approximation by introducing additional constraints which allows to increase the error functional used in the derivation of the shape functions.
An overview of the different methods for optimizing the virtual resources placement in the Cloud Computing
Authors: Ndayikengurukiye Aristide , Ez-Zahout Abderrahmane , Omary Fouzia
Published: January 2021

The emergence of Cloud Computing has driven users of new technologies to adopt it. This is made possible by the used technologies, namely the virtualization, which is the key element in Cloud Computing. The management and orchestration of virtual resources (the virtual machine placement and VNFs) in the Cloud remains a complex task, which, recently, attracted the interest of many researchers. This paper provides an overview of the techniques adopted to optimize the virtual machines placement and the virtual networks functions. Focused on different resources (CPU, memory, bandwidth and storage)applied in a virtualized environment. These techniques always target several approaches including the improvement of the QoS defined in the service level agreements (SLA), the good management of the energy used by physical resources, the allocation of resources and the management tasks in the data center.
Application of empirical analysis to underground mine a study case In morocco
Authors: Ghazdali O. , Tagma T. , Rziki S. , Moustadraf J.
Published: January 2021

The OUMJRANE mine located in the eastern Anti-Atlas in Morocco, is operating underground mining in various sedimentary rocks from sandstones to shales. During operation, several instabilities are recorded in the underground galleries. The present study represents an empirical characterization based on the classification index of the rock mass: RMR (Rock Mass Rating), Q (Tunnel Quality Index) of the stability of the excavation. The input data used for this analysis were based on fracturing surveys, core logging, and laboratory tests. The results of this study show that the rock mass is of low quality.
Big-Parallel-ETL: New ETL for Multidimensional NoSQL Graph Oriented Data
Authors: Soussi Nassima
Published: January 2021

The quantitative explosion of digital data derived from social networks, smart devices, IoT sensors, etc is eventuated by the Big Data concept considered as a very important aspect in the performance improvement of traditional decision-making systems since it reveals serious challenges to be addressed. Therefore, the main purpose of this research paper is the integration of NoSQL Graph-oriented Data into Data Warehouse to deal with Big Data challenges especially with the absence of similar approaches to the best of our knowledge. In this paper, we propose a new approach called Big-Parallel-ETL that aims to adapt the classical ETL process (Extract-Transform-Load) with Big Data technologies to accelerate data handling based on the famous MapReduce concept characterized by its efficient parallel processing feature. Our solution proposes a set of detailed Algorithms based on several rules able to conceive rapidly and efficiently the target multidimensional structure (dimensions and facts) from the NoSQL Graph oriented database.
Congestion Control of Multi-layer Cellular Networks based on Modeling of Transmit Power
Authors: Dai Jiahao , Chen Yongqun , Chen Yucheng , Meng Aodong
Published: January 2021

The explosive growth of network traffic and the limited storage node resources make the existing network architecture bear great pressure, and network congestion appears in work and life from time to time. In order to ensure the timeliness and effectiveness of the network, we propose a congestion control method based on transmission power. Different from previous work, we built a multi-layer cellular network consisting of multiple macro stations, small base stations and mobile terminals. On this basis, we establish a congestion control model based on the mixed queuing model of service window and calculate the input/output rate and congestion. Finally, we use simulation to verify the effectiveness of the congestion model. The network builder can use our model to set the appropriate power of macro stations and small base stations to ensure network stability.
Modeling and Intelligent Identification of Axis Orbit for Rotating Machinery Based on the Convolution Neural Networks
Authors: He Xiaofeng , Liu Xiaofeng , Lu Xiulian , He Lipeng , Ma Yunxiang , Guo Sheng , Yang Tao
Published: January 2021

Based on the high dimensional complex feature recognition capability of convolutional neural networks (CNN), this paper proposes a method for orbit intelligent identification of rotating machinery based on CNN. In this method, the orbit is purified based on the frequency-domain filtering algorithm. Then an algorithm for converting the vibration signal to the orbit matrix is proposed to construct the input matrix of CNN. Finally the classification model of the CNN is established to realize the automatic identification of the orbit of rotating machines. Case studies show that the proposed method has high identification accuracy over 85% on experimental data and good universality over 73% in field data identification.
Avalanche Dynamics of Multi-Information Propagation Modelling
Authors: Wang Jingjing , Xu Yizhan , Tang Ming
Published: January 2021

With the rapid development of social network information technology, some information can spread in a wide range while others are difficult to diffuse and quickly vanish. Previous researches have carried out some empirical analysis and theoretical methods on the information dissemination such as news and rumours, but few of them study multiple information dissemination process based on empirical data. Here, we study the online true and false information diffusion based on a Twitter dataset. We analyse their difference on size, depth, annual generation and annual transmission, and find that the spreading ability of false information is significantly stronger than that of true information. Then, we propose a novel multi-information propagation model, which considers the probability of information generation and transmission. With limited attention of users, different true and false information will compete for attention and ultimately lead to the heterogeneity of information size. Extensive numerical simulations demonstrate that the competition of these two information will transit from insufficient state to sufficient state, which will introduce the criticality of the information dissemination system. Furthermore, we study the impact of information generation and transmission probability to the spreading ability, and find that they can significantly affect the distribution of information size, which is consistent with the empirical results. This work helps to understand the dissemination characteristics of the true and false information on online social networks and would promote further studies on the critical phenomenon of information dissemination.
Detection of Common Foreign Objects on Power Grid Lines Based on Faster R-CNN Algorithm and Data Augmentation Method
Authors: Zu Guangxin , Wu Guoliang , Zhang Chong , He Xing
Published: January 2021

Foreign objects hanging on the electrical equipment are big threats to the safety of the power grid. In this paper, a high-precision object detection model designed for common foreign objects in power grid based on Faster R-CNN algorithm is proposed. The data augmentation methods such as rotation, adjusting brightness and colour saturation, adding Gaussian noise are carried out to expand the data in the training set. The accuracy rate and the recall rate of the model reach 93.09% and 94.33% respectively. The object detection model trained by the training set with data augmentation has achieved better detection results.
Multi-objective Task Scheduling Algorithm Based on Harmony Search for Grid Microservice Optimization
Authors: Xie Yuqing , Wang Yuan , Jiang Ying , Peng Zirong , Wang Yongli
Published: January 2021

In order to solve the multi-objective task scheduling optimization problem of data platform microservice combination, this paper proposes an improved harmony search algorithm MODRHS, which fuses the multi-objective optimization NSGA-II algorithm, and improve its elite selection strategy by a circular elimination method, and strengthens the uniformity of the non-dominated solutions at first layer and improves the algorithm’s Pareto optimization ability. At the same time, it describes the mathematical expression of the Dockers model and service optimization goals of the data platform microservice scheduling. The improved harmony search algorithm is applied to practical problems. The performance test of MODRHS is carried out through standard test functions and real data sets. Compared with other classic multi-objective optimization algorithms, the convergence and diversity of the MODRHS algorithm have been effectively improved.
Algorithm Modeling of Smile Intensity Estimation Using a Spatial Attention Convolutional Neural Network
Authors: Luo Zhenzhen , Sha Zongyu , Jin Chen , Xu Ning
Published: January 2021

Smile intensity estimation is a challenging task as it required subtle feature extraction, self-adapted weighted model and classifier. complexity of the problem domains, and problems on fine-grained image recognition are some of the issues related to intensity estimation. In this study, we designed a self-weighted deep convolutional neural network architecture for smiles intensity estimation using graphics processing unit. In the case of using only CK+ smile images, the accuracy of the model is also higher than that of the latest technology. Our model achieved better accuracy by just using CK+ smile images than state-of-the-art techniques. Visualizations of learned features at various layers and their deconvolutions are also presented for understanding the learning process.
Simulation and Derivative Analysis of Operation Effect of Electricity Spot Market
Authors: Tang Yao , Xiao Yanwei , Wang Gaoqin
Published: January 2021

Under the background of global power market reform, the construction of China’s electricity spot market is a hot spot in China. In order to ensure the safe and stable operation of the power system, it is necessary to carry out detailed simulation before the reform. In this paper, a simulation platform is developed to fit the characteristics of the spot market, and a set of evaluation indexes that can be used to quantify the market operation effect is designed. Based on the data of typical summer and winter load days in an area of East China, the operation of the spot market is simulated. The results show that the index can reasonably evaluate the operation effect of the market in a variety of scenarios.
Research on Interior Design Optimization based on Virtual Reality Technology
Authors: Zhu Zhongcui , Du Yan
Published: January 2021

The professional knowledge structure system of interior design pays attention to the continuous improvement of the comprehensive quality of interior designers. Interior designers should not only master the traditional design skills, but also master the most advanced and cutting-edge new technologies, so as to apply them to the practical projects of interior design. Virtual reality technology based on building digitization is being applied in various types of high-end indoor and outdoor construction projects, which builds a real bridge between designers and users and greatly enriches the interior space art. Research on the application of virtual reality technology in the field of interior design will guide the development of interior design industry better, more scientifically and systematically.
Numerical Analysis and Optimization Application Trend of Deepfake Video Inspection Technology
Authors: Xia Jiyu , Hua Man
Published: January 2021

Science and technology can be a double-edged sword. Novel digital technologies not only allow people to enjoy more digital achievements, but also make it increasingly difficult to distinguish the authenticity of digital information. This review begins with a brief introduction of the deepfake technology, followed by an explanation of the possible hazards of deepfake, and finally, an overview of the detection technology and research status of deepfake.
Chemical and mechanical bases of coating application in vibration technological systems
Authors: Ivanov V V , Popov S I , Dontsov N S , Marchenko Ju V , Ryzhkin N V , Oleynikova Ju A
Published: January 2021

The article presents the study of vibrational chemico-mechanical coatings. The energy model of coating formation in vibration technological systems is proposed. The classification is developed depending on the energy capacity of the system (the nature and intensity of the processes occurring between the base and the coating). The advantages of vibrational chemical-mechanical coatings over traditional coating and the scope of their practical application are shown. Comparative trials of vibrational chemico-mechanical coatings (Vamp) formed using this vibratory equipment and coatings obtained by conventional methods (electroplating, manual application have demonstrated a number of undeniable advantages and quality indicators of vibrational chemico-mechanical coatings.
Playing TAG with Bennu
Authors: Hanna Kerri Donaldson
Published: January 2021

Kerri Donaldson Hanna summarizes what the much-anticipated sampling of asteroid Bennu has already told us about this primitive yet complex body
Stitching together, apart
Authors: Hogan Annie
Published: January 2021

Annie Hogan explains how the RAS Bicentennial Quilt has progressed through lockdown
A greedy approach for mutual exclusivity analysis in cancer study
Authors: Fang Hongyan , Zhang Zeyu , Zhou Yinsheng , Jin Lishuai , Yang Yaning
Published: January 2021

The main challenge in cancer genomics is to distinguish the driver genes from passenger or neutral genes. Cancer genomes exhibit extensive mutational heterogeneity that no two genomes contain exactly the same somatic mutations. Such mutual exclusivity (ME) of mutations has been observed in cancer data and is associated with functional pathways. Analysis of ME patterns may provide useful clues to driver genes or pathways and may suggest novel understandings of cancer progression. In this article, we consider a probabilistic, generative model of ME, and propose a powerful and greedy algorithm to select the mutual exclusivity gene sets. The greedy method includes a pre-selection procedure and a stepwise forward algorithm which can significantly reduce computation time. Power calculations suggest that the new method is efficient and powerful for one ME set or multiple ME sets with overlapping genes. We illustrate this approach by analysis of the whole-exome sequencing data of cancer types from TCGA.
MicroRNA-374b inhibits breast cancer progression through regulating CCND1 and TGFA genes
Authors: Liu Yan , Zhang Ai , Bao Ping-Ping , Lin Li , Wang Yina , Wu Haijian , Shu Xiao-Ou , Liu Aiguo , Cai Qiuyin
Published: January 2021

Emerging evidence indicates that microRNAs (miRNAs) play a critical role in breast cancer development. We recently reported that a higher expression of miR-374b in tumor tissues was associated with a better disease-free survival of triple-negative breast cancer (TNBC). However, the functional significance and molecular mechanisms underlying the role of miR-374b in breast cancer are largely unknown. In this current study, we evaluated the biological functions and potential mechanisms of miR-374b in both TNBC and non-TNBC. We found that miR-374b was significantly downregulated in breast cancer tissues, compared to adjacent tissues. MiR-374b levels were also lower in breast cancer cell lines, as compared to breast epithelial cells. In vitro and in vivo studies demonstrated that miR-374b modulates the malignant behavior of breast cancer cells, such as cell proliferation in 2D and 3D, cell invasion ability, colony-forming ability and tumor growth in mice. By using bioinformatics tools, we predicted that miR-374b plays a role in breast cancer cells through negatively regulating cyclin D1 (CCND1) and transforming growth factor alpha (TGFA). We further confirmed that CCND1 and TGFA contribute to the malignant behavior of breast cancer cells in vitro and in vivo. Our rescue experiments showed that overexpressing CCND1 or TGFA reverses the phenotypes caused by miR-374b overexpression. Taken together, our studies suggest that miR-374b modulates malignant behavior of breast cancer cells by negatively regulating CCND1 and TGFA genes. The newly identified miR-374b-mediated CCND1 and TGFA gene silencing may facilitate a better understanding of the molecular mechanisms of breast cancer progression.
L-Histidinium Chiral Ionic Liquid Functionalized β-Cyclodextrin as Chiral Selector in Capillary Electrophoresis
Authors: Ma Xiaofei , Li Jingtang , Li Xiaoqi , Feng Zijie , Yang Xuan , Liu Jie , Du Yingxiang
Published: January 2021

Nowadays, ionic liquids (ILs) functionalized cyclodextrins (CDs) have drawn increasing attention in chiral separation. Herein, a novel β-CD derivative functionalized by L-histidinium IL, mono-6-deoxy-6-L-histidinium-β-cyclodextrin chloride (L-HMCDCl), was synthesized for the first time and utilized for enantioseparation of nefopam and chlorphenamine in capillary electrophoresis. The L-HMCDCl exhibited superior enantioselectivity compared with native β-CD. The effect of some key parameters such as chiral selector concentration, buffer pH and applied voltage on the enantioseparation was investigated in detail. In the interest of the chiral discrimination mechanism and the enhanced enantioselectivity of L-HMCDCl, molecular modeling with AutoDock was employed to study the interaction, which was in good agreement with experimental results.
The Politics of Power Projection: The Pivot to Asia, Its Failure, and the Future of American Primacy
Authors: Harris Peter , Trubowitz Peter
Published: January 2021

Why did the Obama administration's attempted pivot (or “rebalance”) to Asia fail? In this article, we argue that three interrelated domestic factors are to blame: hyper-partisanship in Washington, DC; the lack of a compelling foreign-policy narrative to make the pivot intelligible and attractive to a broad slice of the political class and domestic public; and the related failure to convince enough Americans that the pivot was necessary to boost their economic fortunes. These domestic stumbling blocks made it impossible for the Obama administration to invest US power assets toward a long-term programmatic endeavor in the Asia-Pacific. In making this argument about the domestic foundations of US power-projection, we improve upon existing explanations of the pivot's undoing that focus on international-level obstacles, problems with the pivot's design and implementation, or the unexpected election of Donald Trump as Obama's successor. We conclude by drawing implications for US power projection beyond the pivot and, indeed, beyond East Asia—suggesting that the US political system has become a weak foundation upon which to build any ambitious foreign-policy superstructure.
A multicenter prospective audit to investigate the current management of patients undergoing anti-reflux surgery in the UK: Audit & Review of Anti-Reflux Operations & Workup
Authors:   The ARROW Study Group, Walker Rob , Wiggins Tom , Blencowe Natalie S , Findlay John M , Wilson Michael , Currie Andrew C , Hornby Steve , Markar Sheraz R , Rahman Saqib , Lloyd Megan , Hollyman Marianne , Jaunoo Shameen
Published: January 2021

Background

There are a variety of surgical and endoscopic interventions available to treat gastroesophageal reflux disease. There is, however, no consensus on which approach is best.

The aim of this national audit is to describe the current variation in the UK clinical practice in relation to anti-reflux surgery (ARS) and to report adherence to available clinical guidelines.

Methods

This national audit will be conducted at centers across the UK using the secure online web platform ALEA. The study will comprise two parts: a registration questionnaire and a prospective multicenter audit of ARS. All participating centers will be required to complete the registration questionnaire comprising details regarding pre-, peri-, and post-operative care pathways and whether or not these are standardized within each center. Following this, a 12-month multicenter prospective audit will be undertaken to capture data including patient demographics, predominant symptoms, preoperative investigations, surgery indication, intraoperative details, and postoperative outcomes within the first 90 days.

Local teams will retain access to their own data to facilitate local quality improvement. The full dataset will be reported at national and international scientific congresses and will contribute to peer-reviewed publications and national quality improvement initiatives.

Conclusions

This study will identify and explore variation in the processes and outcomes following ARS within the UK using a collaborative cohort methodology. The results generated by this audit will facilitate local and national quality improvement initiatives and generate new possibilities for future research in anti-reflux interventions.
Camilo Barcia Trelles on Francisco de Vitoria: At the Crossroads of Carl Schmitt’s Grossraum and James Brown Scott’s ‘Modern International Law’
Authors: Beneyto José María
Published: January 2021

Carl Schmitt’s The Nomos of the Earth in the International Law of the Jus Publicum Europaeum (1950) undertook a re-interpretation of the modern origins of the discipline of international law, placing Vitoria at its pivot, as the Spanish international law professor Camilo Barcia Trelles (1888–1977) had done before. Barcia’s work had a strong influence on some of the seminal pieces on international law and geopolitics that Schmitt wrote in the period from 1941 to 1950. This was the case for Schmitt’s historical mythology of the opposition between sea and earth and its juridical consequence, his doctrine of the Grossraum, which had as its basis Barcia’s account of the Monroe Doctrine, and also of Schmitt’s critique of the ‘discrimination of war’ formalized in the Kellogg–Briand Pact. According to Barcia, the exclusion of European powers from the American continent by the United States as a rising hegemon was transformed – thanks to its domination of the sea – into the global reach of a world police power. Barcia did not agree with Brown Scott’s transformation of international law through American liberal internationalism into ‘modern international law’. While Brown Scott and Schmitt were competing for two opposing vernaculars of the discipline in search for a new definition and to shape it, Barcia was instrumental in the opposed efforts of these two apparently very dissimilar representatives of international law by ushering Vitoria into their service.
‘Belly-Worshippers and Greed-Paunches’: Fatness and the Belly in the Lutheran Reformation
Authors: Fletcher Holly
Published: January 2021

Corpulence is an area of body-history which is receiving increased attention in line with current concerns about rising obesity as well as social movements which champion body positivity and fat acceptance. Historians have challenged the traditional narrative that in past societies being ‘fat’ was simply viewed as a positive sign of wealth and prosperity, showing instead that fatness could be criticized as early as the sixteenth century. Yet the complexities and contradictions present in historical understandings of bodyweight and size often remain overlooked. This article explores such nuances in conceptions of fatness and thinness by examining the various ways in which bodyweight and size held meaning in the specific context of the Lutheran Reformation. Through a consideration of the bodily resurrection, apocalyptic belief and the form of heavenly bodies, it demonstrates how discussions of weight and fatness were embedded in fundamental debates about sin and salvation. Within these discussions, the significance of the belly comes to the fore. For Luther in particular, the belly was a source of nuance, enabling understandings of weight to be flexible and presenting the complexity of differentiating between fat and thin bodies, where ‘fat’ could be deployed as a metaphor regardless of actual physicality. Luther’s own large size has been shown to be linked to his theology as well as to his success as a reformer, and this article takes this position further, using the figure of Luther as a lens through which to view the wider significance of bodyweight and size in the Reformation.
Streamlining data-intensive biology with workflow systems
Authors: Reiter Taylor , Brooks† Phillip T , Irber† Luiz , Joslin† Shannon E K , Reid† Charles M , Scott† Camille , Brown C Titus , Pierce-Ward N Tessa
Published: January 2021

As the scale of biological data generation has increased, the bottleneck of research has shifted from data generation to analysis. Researchers commonly need to build computational workflows that include multiple analytic tools and require incremental development as experimental insights demand tool and parameter modifications. These workflows can produce hundreds to thousands of intermediate files and results that must be integrated for biological insight. Data-centric workflow systems that internally manage computational resources, software, and conditional execution of analysis steps are reshaping the landscape of biological data analysis and empowering researchers to conduct reproducible analyses at scale. Adoption of these tools can facilitate and expedite robust data analysis, but knowledge of these techniques is still lacking. Here, we provide a series of strategies for leveraging workflow systems with structured project, data, and resource management to streamline large-scale biological analysis. We present these practices in the context of high-throughput sequencing data analysis, but the principles are broadly applicable to biologists working beyond this field.
Dolutegravir pharmacokinetics during co-administration with either artemether/lumefantrine or artesunate/amodiaquine
Authors: Kawuma Aida N , Walimbwa Stephen I , Pillai Goonaseelan (Colin) , Khoo Saye , Lamorde Mohammed , Wasmann Roeland E , Denti Paolo
Published: January 2021

Background

In sub-Saharan Africa, artemisinin-containing therapies for malaria treatment are regularly co-administered with ART. Currently, dolutegravir-based regimens are recommended as first-line therapy for HIV across most of Africa.

Objectives

To investigate the population pharmacokinetics of dolutegravir during co-administration with artemether/lumefantrine or artesunate/amodiaquine, two commonly used antimalarial therapies.

Methods

We developed a population pharmacokinetic model of dolutegravir with data from 26 healthy volunteers in two Phase 2 studies with a total of 403 dolutegravir plasma concentrations at steady state. Volunteers received 50 mg of dolutegravir once daily alone or in combination with standard treatment doses of artemether/lumefantrine (80/480 mg) or artesunate/amodiaquine (200/540 mg).

Results

A two-compartment model with first-order elimination and transit compartment absorption best described the concentration–time data of dolutegravir. Typical population estimates for clearance, absorption rate constant, central volume, peripheral volume and mean absorption transit time were 0.713 L/h, 1.68 h−1, 13.2 L, 5.73 L and 1.18 h, respectively. Co-administration of artemether/lumefantrine or artesunate/amodiaquine increased dolutegravir clearance by 10.6% (95% CI 4.09%–34.5%) and 26.4% (95% CI 14.3%–51.4%), respectively. Simulations showed that simulated trough concentrations of dolutegravir alone or in combination with artemether/lumefantrine or artesunate/amodiaquine are maintained above the dolutegravir protein-adjusted IC90 of 0.064 mg/L for more than 99% of the individuals.

Conclusions

Dolutegravir dose adjustments are not necessary for patients who are taking standard 3 day treatment doses of artemether/lumefantrine or artesunate/amodiaquine.
High susceptibility to zoliflodacin and conserved target (GyrB) for zoliflodacin among 1209 consecutive clinicalNeisseria gonorrhoeaeisolates from 25 European countries, 2018
Authors: Unemo Magnus , Ahlstrand Josefine , Sánchez-Busó Leonor , Day Michaela , Aanensen David , Golparian Daniel , Jacobsson Susanne , Cole Michelle J ,   the European Collaborative Group, Torreblanca Raquel Abad , Ásmundsdóttir Lena Rós , Balla Eszter , De Baetselier Irith , Bercot Beatrice , Carannante Anna , Caugant Dominique , Borrego Maria José , Buder Susanne , Cassar Robert , Cole Michelle , Dam Alje van , Eder Claudia , Hoffmann Steen , Hunjak Blazenka , Jeverica Samo , Kirjavainen Vesa , Maikanti-Charalambous Panayiota , Miriagou Vivi , Mlynarczyk-Bonikowska Beata , Pakarna Gatis , Patterson Lynsey , Pavlik Peter , Perrin Monique , Shepherd Jill , Stefanelli Paola , Unemo Magnus , Viktorova Jelena , Zákoucká Hana
Published: January 2021

Objectives

Novel antimicrobials for treatment of gonorrhoea are imperative. The first-in-class spiropyrimidinetrione zoliflodacin is promising and currently in an international Phase 3 randomized controlled clinical trial (RCT) for treatment of uncomplicated gonorrhoea. We evaluated the in vitro activity of and the genetic conservation of the target (GyrB) and other potential zoliflodacin resistance determinants among 1209 consecutive clinical Neisseria gonorrhoeae isolates obtained from 25 EU/European Economic Area (EEA) countries in 2018 and compared the activity of zoliflodacin with that of therapeutic antimicrobials currently used.

Methods

MICs of zoliflodacin, ceftriaxone, cefixime, azithromycin and ciprofloxacin were determined using an agar dilution technique for zoliflodacin or using MIC gradient strip tests or an agar dilution technique for the other antimicrobials. Genome sequences were available for 96.1% of isolates.

Results

Zoliflodacin modal MIC, MIC50, MIC90 and MIC range were 0.125, 0.125, 0.125 and ≤0.004–0.5 mg/L, respectively. The resistance was 49.9%, 6.7%, 1.6% and 0.2% to ciprofloxacin, azithromycin, cefixime and ceftriaxone, respectively. Zoliflodacin did not show any cross-resistance to other tested antimicrobials. GyrB was highly conserved and no zoliflodacin gyrB resistance mutations were found. No fluoroquinolone target GyrA or ParC resistance mutations or mutations causing overexpression of the MtrCDE efflux pump substantially affected the MICs of zoliflodacin.

Conclusions

The in vitro susceptibility to zoliflodacin was high and the zoliflodacin target GyrB was conserved among EU/EEA gonococcal isolates in 2018. This study supports further clinical development of zoliflodacin. However, additional zoliflodacin data regarding particularly the treatment of pharyngeal gonorrhoea, pharmacokinetics/pharmacodynamics and resistance selection, including suppression, would be valuable.
Defining Multimorbidity and Its Impact in Older United States Veterans Newly Treated for Multiple Myeloma
Authors: Fillmore Nathanael R , DuMontier Clark , Yildirim Cenk , La Jennifer , Epstein Mara M , Cheng David , Cirstea Diana , Yellapragada Sarvari , Abel Gregory A , Gaziano J Michael , Do Nhan , Brophy Mary , Kim Dae H , Munshi Nikhil C , Driver Jane A
Published: January 2021

Background

 Traditional count-based measures of comorbidity are unlikely to capture the complexity of multiple chronic conditions (multimorbidity) in older adults with cancer. We aimed to define patterns of multimorbidity and their impact in older United States veterans with multiple myeloma (MM).

Methods

 We measured 66 chronic conditions in 5076 veterans aged 65 years and older newly treated for MM in the national Veterans Affairs health-care system from 2004 to 2017. Latent class analysis was used to identify patterns of multimorbidity among these conditions. These patterns were then assessed for their association with overall survival, our primary outcome. Secondary outcomes included emergency department visits and hospitalizations.

Results

Five patterns of multimorbidity emerged from the latent class analysis, and survival varied across these patterns (log-rank 2-sided P < .001). Older veterans with cardiovascular and metabolic disease (30.9%, hazard ratio [HR] = 1.33, 95% confidence interval [CI] = 1.21 to 1.45), psychiatric and substance use disorders (9.7%, HR = 1.58, 95% CI = 1.39 to 1.79), chronic lung disease (15.9%, HR = 1.69, 95% CI = 1.53 to 1.87), and multisystem impairment (13.8%, HR = 2.25, 95% CI = 2.03 to 2.50) had higher mortality compared with veterans with minimal comorbidity (29.7%, reference). Associations with mortality were maintained after adjustment for sociodemographic variables, measures of disease risk, and the count-based Charlson Comorbidity Index. Multimorbidity patterns were also associated with emergency department visits and hospitalizations.

Conclusions

Our findings demonstrate the need to move beyond count-based measures of comorbidity and consider cancer in the context of multiple chronic conditions.
A new tension in the cosmological model from primordial deuterium?
Authors: Pitrou Cyril , Coc Alain , Uzan Jean-Philippe , Vangioni Elisabeth
Published: January 2021

Recent measurements of the D(p,γ)3He nuclear reaction cross-section and of the neutron lifetime, along with the reevaluation of the cosmological baryon abundance from cosmic microwave background (CMB) analysis, call for an update of abundance predictions for light elements produced during the big-bang nucleosynthesis (BBN). While considered as a pillar of the hot big-bang model in its early days, BBN constraining power mostly rests on deuterium abundance. We point out a new ≃1.8σ tension on the baryonic density, or equivalently on the D/H abundance, between the value inferred on one hand from the analysis of the primordial abundances of light elements and, on the other hand, from the combination of CMB and baryonic oscillation data. This draws the attention on this sector of the theory and gives us the opportunity to reevaluate the status of BBN in the context of precision cosmology. Finally, this paper presents an upgrade of the BBN code primat.
ASKAP observations of multiple rapid scintillators reveal a degrees-long plasma filament
Authors: Wang Yuanming , Tuntsov Artem , Murphy Tara , Lenc Emil , Walker Mark , Bannister Keith , Kaplan David L , Mahony Elizabeth K
Published: January 2021

We present the results from an Australian Square Kilometre Array Pathfinder search for radio variables on timescales of hours. We conducted an untargeted search over a 30 deg2 field, with multiple 10-h observations separated by days to months, at a central frequency of 945 MHz. We discovered six rapid scintillators from 15-min model-subtracted images with sensitivity of $\sim\! 200\, \mu$Jy/beam; two of them are extreme intra-hour variables with modulation indices up to $\sim 40{{\ \rm per\ cent}}$ and timescales as short as tens of minutes. Five of the variables are in a linear arrangement on the sky with angular width ∼1 arcmin and length ∼2 degrees, revealing the existence of a huge plasma filament in front of them. We derived kinematic models of this plasma from the annual modulation of the scintillation rate of our sources, and we estimated its likely physical properties: a distance of ∼4 pc and length of ∼0.1 pc. The characteristics we observe for the scattering screen are incompatible with published suggestions for the origin of intra-hour variability leading us to propose a new picture in which the underlying phenomenon is a cold tidal stream. This is the first time that multiple scintillators have been detected behind the same plasma screen, giving direct insight into the geometry of the scattering medium responsible for enhanced scintillation.
Survey of Gravitationally Lensed Objects in HSC Imaging (SuGOHI) – VII. Discovery and confirmation of three strongly lensed quasars†
Authors: Jaelani Anton T , Rusu Cristian E , Kayo Issha , More Anupreeta , Sonnenfeld Alessandro , Silverman John D , Schramm Malte , Anguita Timo , Inada Naohisa , Kondo Daichi , Schechter Paul L , Lee Khee-Gan , Oguri Masamune , Chan James H H , Wong Kenneth C , Inoue Kaiki T
Published: January 2021

We present spectroscopic confirmation of three new two-image gravitationally lensed quasars, compiled from existing strong lens and X-ray catalogues. Images of HSC J091843.27–022007.5 show a red galaxy with two blue point sources at either side, separated by 2.26 arcsec. This system has a source and a lens redshifts zs = 0.804 and zℓ = 0.459, respectively, as obtained by our follow-up spectroscopic data. CXCO J100201.50+020330.0 shows two point sources separated by 0.85 arcsec on either side of an early-type galaxy. The follow-up spectroscopic data confirm the fainter quasar has the same redshift with the brighter quasar from the Sloan Digital Sky Survey (SDSS) fiber spectrum at zs = 2.016. The deflecting foreground galaxy is a typical early-type galaxy at a redshift of zℓ = 0.439. SDSS J135944.21+012809.8 has two point sources with quasar spectra at the same redshift zs = 1.096, separated by 1.05 arcsec, and fits to the HSC images confirm the presence of a galaxy between these. These discoveries demonstrate the power of the Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP)’s deep imaging and wide sky coverage. Combined with existing X-ray source catalogues and follow-up spectroscopy, the HSC-SSP provides us unique opportunities to find multiple-image quasars lensed by a foreground galaxy.
Precessing magnetars as central engines in short gamma-ray bursts
Authors: Suvorov A G , Kokkotas K D
Published: January 2021

Short gamma-ray bursts that are followed by long-duration X-ray plateaus may be powered by the birth, and hydrodynamic evolution, of magnetars from compact binary coalescence events. If the rotation and magnetic axes of the system are not orthogonal to each other, the star will undergo free precession, leading to fluctuations in the luminosity of the source. In some cases, precession-induced modulations in the spin-down power may be discernible in the X-ray flux of the plateau. In this work, 25 X-ray light curves associated with bursts exhibiting a plateau are fitted to luminosity profiles appropriate for precessing, oblique rotators. Based on the Akaike Information Criterion, 16 $(64{{\ \rm per\ cent}})$ of the magnetars within the sample display either moderate or strong evidence for precession. Additionally, since the precession period of the star is directly tied to its quadrupolar ellipticity, the fits allow for an independent measure of the extent to which the star is deformed by internal stresses. Assuming these deformations arise due to a mixed poloidal–toroidal magnetic field, we find that the distribution of magnetic-energy ratios is bimodal, with data points clustering around energetically equal and toroidally dominated partitions. Implications of this result for gravitational-wave emission and dynamo activity in newborn magnetars are discussed.
Monte Carlo simulations of multiple populations in globular clusters: constraints on the cooling flow versus accretion scenario using million bodies simulations
Authors: Sollima A
Published: January 2021

I simulate the evolution of a stellar system hosting two stellar populations whose initial set-up is defined according to the two main scenarios proposed for the origin of multiple populations in Galactic globular clusters: (i) formation of a second generation from a cooling flow of pristine+polluted gas and (ii) accretion of polluted gas on to the proto-stellar discs of a fraction of low-mass stars. For this purpose, Monte Carlo simulations containing from 105 up to 3 × 106 particles have been run including the effect of stellar evolution, binary interactions, external tidal field, and a detailed modelling of the proto-stellar disc structure. The early accretion of gas on to proto-stellar discs is unable to produce discrete populations and to alter the chemical composition of a significant ($\gt 10{{\ \rm per\ cent}}$) fraction of stars unless a disc lifetime larger (tdisc ∼ 20 Myr) than that predicted by models is assumed. Moreover, in this scenario the mixing time-scale of the two populations is too short to reproduce the observed segregation of the chemically enriched population. On the other hand, simulations run within the cooling flow scenario can evolve after a Hubble time into stellar systems with a first-to-second population mass ratio similar to that observed in globular clusters, provided that an initial filling-factor rh/rJ > 0.15 is adopted. However, in the weak tidal field regime a radial segregation of the second population stronger than what observed in Milky Way globular clusters at large Galactocentric distances is predicted. This discrepancy disappears in simulations following eccentric orbits in a realistic axisymmetric potential.
PSR B0656+14: the unified outlook from the infrared to X-rays
Authors: Zharikov S , Zyuzin D , Shibanov Yu , Kirichenko A , Mennickent R E , Geier S , Cabrera-Lavers A
Published: January 2021

We report detection of PSR B0656+14 with the Gran Telescopio Canarias in narrow optical F657, F754, F802, and F902 and near-infrared JHKs bands. The pulsar detection in the Ks band extends its spectrum to 2.2 $\mu$m and confirms its flux increase towards the infrared. We also present a thorough analysis of the optical spectrum obtained by us with the VLT. For a consistency check, we revised the pulsar near-infrared and narrow-band photometry obtained with the HST. We find no narrow spectral lines in the optical spectrum. We compile available near-infrared-optical-UV and archival 0.3–20 keV X-ray data and perform a self-consistent analysis of the rotation phase-integrated spectrum of the pulsar using unified spectral models. The spectrum is best fitted by the four-component model including two blackbodies, describing the thermal emission from the neutron star surface and its hot polar cap, the broken power law, originating from the pulsar magnetosphere, and an absorption line near ∼0.5 keV detected previously. The fit provides better constraints on the model parameters than using only a single spectral domain. The derived surface temperature is $T_{NS}^{\infty } = 7.9(3)\times 10^5$ K. The intrinsic radius (7.8–9.9 km) of the emitting region is smaller than a typical neutron star radius (13 km) and suggests a non-uniform temperature distribution over the star surface. In contrast, the derived radius of the hot polar cap is about twice as large as the ‘canonical’ one. The spectrum of the non-thermal emission steepens from the optical to X-rays and has a break near 0.1 keV. The X-ray data suggest the presence of another absorption line near 0.3 keV.
Constraints on stellar rotation from the evolution of Sr and Ba in the Galactic halo
Authors: Rizzuti F , Cescutti G , Matteucci F , Chieffi A , Hirschi R , Limongi M , Saro A
Published: January 2021

Recent studies show that the chemical evolution of Sr and Ba in the Galaxy can be explained if different production sites, hosting r- and s-processes, are taken into account. However, the question of unambiguously identifying these sites is still unsolved. Massive stars are shown to play an important role in the production of s-material if rotation is considered. In this work, we study in detail the contribution of rotating massive stars to the production of Sr and Ba, in order to explain their chemical evolution, but also to constrain the rotational behaviour of massive stars. A stochastic chemical evolution model was employed to reproduce the enrichment of the Galactic halo. We developed new methods for model-data comparison which help to objectively compare the stochastic results to the observations. We employed these methods to estimate the value of free parameters which describe the rotation of massive stars, assumed to be dependent on the stellar metallicity. We constrain the parameters using the observations for Sr and Ba. Employing these parameters for rotating massive stars in our stochastic model, we are able to correctly reproduce the chemical evolution of Sr and Ba, but also Y, Zr, and La. The data supports a decrease of both the mean rotational velocities and their dispersion with increasing metallicity. Our results show that a metallicity-dependent rotation is a necessary assumption to explain the s-process in massive stars. Our novel methods of model-data comparison represent a promising tool for future galactic chemical evolution studies.
De Novo Mutation and Rapid Protein (Co-)evolution during Meiotic Adaptation in Arabidopsis arenosa
Authors: Bohutínská Magdalena , Handrick Vinzenz , Yant Levi , Schmickl Roswitha , Kolář Filip , Bomblies Kirsten , Paajanen Pirita
Published: January 2021

A sudden shift in environment or cellular context necessitates rapid adaptation. A dramatic example is genome duplication, which leads to polyploidy. In such situations, the waiting time for new mutations might be prohibitive; theoretical and empirical studies suggest that rapid adaptation will largely rely on standing variation already present in source populations. Here, we investigate the evolution of meiosis proteins in Arabidopsis arenosa, some of which were previously implicated in adaptation to polyploidy, and in a diploid, habitat. A striking and unexplained feature of prior results was the large number of amino acid changes in multiple interacting proteins, especially in the relatively young tetraploid. Here, we investigate whether selection on meiosis genes is found in other lineages, how the polyploid may have accumulated so many differences, and whether derived variants were selected from standing variation. We use a range-wide sample of 145 resequenced genomes of diploid and tetraploid A. arenosa, with new genome assemblies. We confirmed signals of positive selection in the polyploid and diploid lineages they were previously reported in and find additional meiosis genes with evidence of selection. We show that the polyploid lineage stands out both qualitatively and quantitatively. Compared with diploids, meiosis proteins in the polyploid have more amino acid changes and a higher proportion affecting more strongly conserved sites. We find evidence that in tetraploids, positive selection may have commonly acted on de novo mutations. Several tests provide hints that coevolution, and in some cases, multinucleotide mutations, might contribute to rapid accumulation of changes in meiotic proteins.