bluuebunny/crossref_metadata_2025 huggingface dataset:
Bacterial Vaginosis and Its Association With Incident Trichomonas vaginalis Infections: A Systematic Review and Meta-Analysis
Authors: Seña Arlene C. , Goldstein Linda A. , Ramirez Gilbert , Parish Austin J. , McClelland R. Scott
Published: August 2021

Background

Bacterial vaginosis (BV) has been associated with an increased risk for acquisition of human immunodeficiency virus and sexually transmitted infections. We evaluated the association between BV and incident Trichomonas vaginalis (TV) infection in women.

Methods

MEDLINE and ClinicalTrials.gov were searched for articles published between January 1, 1980, and May 7, 2021. Observational studies in women that evaluated the relationship between having/not having BV and the risk for acquiring TV were included.

Results

Fourteen studies were included in the systematic review; 12 studies were included in meta-analyses involving 18,424 participants. Most studies used Nugent scoring to diagnose BV. For TV diagnosis, 12 studies used wet mount microscopy or culture, and 2 used nucleic acid amplification tests. There was diversity in the measures of association used, so an overall effect size could not be calculated. The majority of studies reported odds ratios, which showed an increased risk of incident TV among women with BV versus without BV (adjusted odds ratio, 1.87; 95% confidence interval, 1.45–2.40; P = 0.007). However, there were heterogeneity and potential confounding factors (eg, age, sexual partners) reported among studies.

Conclusions

This systematic review and meta-analysis provide evidence for a nearly 2-fold higher risk for acquiring TV among women with BV compared with women without BV.
Performance comparison of micro-neutralization assays based on surrogate SARS-CoV-2 and WT SARS-CoV-2 in assessing virus-neutralizing capacity of anti-SARS-CoV-2 antibodies
Authors: Sekirov Inna , Petric Martin , Carruthers Erin , Lawrence David , Pidduck Tamara , Kustra Jesse , Laley Jonathan , Lee Min-Kuang , Chahil Navdeep , Mak Annie , Levett Paul N. , Mendoza Emelissa , Wood Heidi , Drebot Mike , Krajden Mel , Morshed Muhammad
Published: August 2021

We compared neutralization assays using either the wild-type severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus or surrogate neutralization markers, using characterized sera. We found the results of the neutralization assays 75 % concordant overall and 80 % concordant for samples with high antibody levels. This demonstrates that commercial surrogate SARS-CoV-2 assays offer the potential to assess anti-SARS-CoV-2 antibodies’ neutralizing capacity outside CL-3 laboratory containment.
Evaluation of commercial anti-SARS-CoV-2 antibody assays and comparison of standardized titers in vaccinated healthcare workers
Authors: Saker Kahina , Escuret Vanessa , Pitiot Virginie , Massardier-Pilonchéry Amélie , Paul Stéphane , Mokdad Bouchra , Langlois-Jacques Carole , Rabilloud Muriel , Goncalves David , Fabien Nicole , Guibert Nicolas , Fassier Jean-Baptiste , Bal Antonin , Trouillet-Assant Sophie , Trabaud Mary-Anne
Published: August 2021

With the availability of vaccines, commercial assays detecting anti-SARS-CoV-2 antibodies (Ab) evolved towards quantitative assays directed to the spike glycoprotein or its receptor binding domain (RBD). The main objective of the present study was to compare the Ab titers obtained with quantitative commercial binding Ab assays, after 1 dose (convalescent individuals) or 2 doses (naïve individuals) of vaccine, in healthcare workers (HCW).

Antibody titers were measured in 255 sera (from 150 HCW) with 5 quantitative immunoassays (Abbott RBD IgG II quant, bioMérieux RBD IgG, DiaSorin Trimeric spike IgG, Siemens Healthineers RBD IgG, Wantai RBD IgG). One qualitative total antibody anti RBD detection assay (Wantai) was used to detect previous infection before vaccination. The results are presented in binding Ab units (BAU)/mL after application, when possible, of a conversion factor provided by the manufacturers and established from a World Health Organization (WHO) internal standard.

There was a 100% seroconversion with all assays evaluated after two doses of vaccine. With assays allowing BAU/ml correction, Ab titers were correlated (Pearson correlation coefficient, ρ, range: 0.85-0.94). The titer differences varied by a mean of 10.6% between Siemens and bioMérieux assays to 60.9% between Abbott and DiaSorin assays. These results underline the importance of BAU conversion for the comparison of Ab titer obtained with the different quantitative assays. However, significant differences persist, notably, between kits detecting Ab against the different antigens.

A true standardization of the assays would be to include the International Standard in the calibration of each assays to express the results in IU/mL.
High-grade Ovarian Cancer Associated H/ACA snoRNAs Promote Cancer Cell Proliferation and Survival
Authors: Faucher-Giguère Laurence , Roy Audrey , Deschamps-Francoeur Gabrielle , Couture Sonia , Nottingham Ryan M. , Lambowitz Alan M. , Scott Michelle S. , Elela Sherif Abou
Published: August 2021

Small nucleolar RNAs (snoRNAs) are an omnipresent class of non-coding RNAs involved in the modification and processing of ribosomal RNA (rRNA). As snoRNAs are required for ribosome production, the increase of which is a hallmark of cancer development, their expression would be expected to increase in proliferating cancer cells. However, the nature and extent of snoRNAs contribution to the biology of cancer cells remain largely unexplored. In this study, we examined the abundance patterns of snoRNA in high-grade serous ovarian carcinomas (HGSC) and serous borderline tumours (SBT) and identified a subset of snoRNA associated with increased invasiveness. This subgroup of snoRNA accurately discriminates between SBT and HGSC underlining their potential as biomarkers of tumour aggressiveness. Remarkably, knockdown of HGSC-associated H/ACA snoRNAs, but not their host genes, inhibits cell proliferation and induces apoptosis of model ovarian cancer cell lines. Wound healing and cell migration assays confirmed the requirement of these HGSC-associated snoRNA for cell invasion and increased tumour aggressiveness. Together our data indicate that H/ACA snoRNAs promote tumour aggressiveness through the induction of cell proliferation and resistance to apoptosis.
Dual signaling via interferon and DNA damage response elicits entrapment by giant PML nuclear bodies
Authors: Scherer Myriam , Read Clarissa , Neusser Gregor , Kranz Christine , Müller Regina , Full Florian , Wörz Sonja , Reichel Anna , Schilling Eva-Maria , Walther Paul , Stamminger Thomas
Published: August 2021

PML nuclear bodies (PML-NBs) are dynamic interchromosomal macromolecular complexes implicated in epigenetic regulation as well as antiviral defense. During herpesvirus infection, PML-NBs induce epigenetic silencing of viral genomes, however, this defense is antagonized by viral regulatory proteins such as IE1 of human cytomegalovirus (HCMV). Here, we show that PML-NBs undergo a drastic rearrangement into highly enlarged PML cages upon infection with IE1-deficient HCMV. Importantly, our results demonstrate that dual signaling by interferon and DNA damage response is required to elicit giant PML-NBs. DNA labeling revealed that invading HCMV genomes are entrapped inside PML-NBs and remain stably associated with PML cages in a transcriptionally repressed state. Intriguingly, by correlative light and transmission electron microscopy (EM), we observed that PML cages also entrap newly assembled viral capsids demonstrating a second defense layer in cells with incomplete first line response. Further characterization by 3D EM showed that hundreds of viral capsids are tightly packed into several layers of fibrous PML. Overall, our data indicate that giant PML-NBs arise via combined interferon and DNA damage signaling which triggers entrapment of both nucleic acids and proteinaceous components. This represents a multilayered defense strategy to act in a cytoprotective manner and to combat viral infections.
Structural dynamics determine voltage and pH gating in human voltage-gated proton channel
Authors: Han Shuo , Peng Sophia , Vance Joshua , Tran Kimberly , Do Nhu , Gates Decker , Bui Nauy , Gui Zhenhua , Wang Shizhen
Published: August 2021

Voltage-gated ion channels are key players of electrical signaling in cells. As a unique subfamily, voltage-gated proton (Hv) channels are standalone voltage sensors without separate ion conductive pores. They are gated by both voltage and transmembrane proton gradient (i.e ΔpH), serving as acid extruders in most cells. Amongst their many functions, Hv channels are known to regulate the intracellular pH of human spermatozoa and compensate for the charge and pH imbalances caused by NADPH oxidases in phagocytes. Like the canonical voltage sensors, the Hv channel is a bundle of 4 helices (named S1 through S4), with the S4 segment carrying 3 positively charged Arg residues. Extensive structural and electrophysiological studies on voltage-gated ion channels generally agree on an outwards movement of the S4 segment upon activating voltage, but the real time conformational transitions are still unattainable. With purified human voltage-gated proton (hHv1) channel reconstituted in liposomes, we have examined its conformational dynamics at different voltage and pHs using the single molecule fluorescence resonance energy transfer (smFRET). Here we provided the first glimpse of real time conformational trajectories of the hHv1 voltage sensor and showed that both voltage and pH gradient shift the conformational dynamics of the S4 segment to control channel gating. Our results suggested the biological gating is determined by the conformational distributions of the hHv1 voltage sensor, rather than the conformational transitions between the presumptive ‘resting’ and ‘activated’ conformations. We further identified H140 as the key residue sensing extracellular pH and showed that both the intracellular and extracellular pH sensors act on the voltage sensing S4 segment to enrich the resting conformations. Taken together, we proposed a model that explains the mechanisms underlying voltage and pH gating in Hv channels, which may also serve as a general framework to understand the voltage sensing and gating in other voltage-gated ion channels.
Physical localization of 45S rDNA in Cymbopogon and the analysis of differential distribution of rDNA in homologous chromosomes of Cymbopogon winterianus
Authors: Thakur Shivangi , Kumar Upendra , Malik Rashmi , Bisht Darshana , Balyan Priyanka , Mir Reyazul Rouf , Kumar Sundip
Published: August 2021

Cymbopogon, commonly known as lemon grass, is one of the most important aromatic grasses having therapeutic and medicinal values. FISH signals on somatic chromosome spreads off Cymbopogon species indicated the localization of 45S rDNA on the terminal region of short arms of a chromosome pair. A considerable interspecific variation in the intensity of 45S rDNA hybridization signals was observed in the cultivars of Cymbopogon winterianus and Cymbopogon flexuosus. Furthermore, in all the varieties of Cymbopogon winterianus namely Bio-13, Manjari and Medini, a differential distribution of 45S rDNA was observed in a heterologous pair of chromosome 1. The development of Cymbopogon winterianus var. Manjari through gamma radiation may be responsible for breakage of fragile rDNA site from one of the chromosomes of this heterologous chromosome pair. While, in other two varieties of Cymbopogon winterianus (Bio-13 and Medini), this variability may be because of evolutionary speciation due to natural cross among two species of Cymbopogon which was fixed through clonal propagation. However, in both the situations these changes were fixed by vegetative method of propagation which is general mode of reproduction in the case of Cymbopogon winterianus.
Bacterial keratitis: similar bacterial and clinical outcomes in female versus male New Zealand White rabbits infected withSerratia marcescens
Authors: Romanowski Eric G. , Yadav Sanya , Stella Nicholas A. , Yates Kathleen A. , Romanowski John E. , Dhaliwal Deepinder K. , Shanks Robert M. Q.
Published: August 2021

Females and males respond differently to a number of systemic viral infections. Differences between females and males with respect to the severity of keratitis caused by Gram-negative bacteria such asSerratia marcescensare less well established. In this study we injected female and male New Zealand White rabbit corneas with a keratitis isolate ofS. marcescensand evaluated the eyes after 48 hours for a number of clinical and microbiological parameters. No statistical differences in bacterial burden and corneal scores were recorded between female and male rabbits although there was a non-significant trend toward a higher frequency of female rabbits demonstrating hypopyons. This data suggests that for experimental bacterial keratitis studies involving Gram-negative rods, a single sex or mixed group of rabbit is sufficient for evaluating pathology and bacterial burdens. This will reduce the number of animals used for subsequent studies.
AlphaFold2-aware protein-DNA binding site prediction using graph transformer
Authors: Yuan Qianmu , Chen Sheng , Rao Jiahua , Zheng Shuangjia , Zhao Huiying , Yang Yuedong
Published: August 2021

Protein-DNA interactions play crucial roles in the biological systems, and identifying protein-DNA binding sites is the first step for mechanistic understanding of various biological activities (such as transcription and repair) and designing novel drugs. How to accurately identify DNA-binding residues from only protein sequence remains a challenging task. Currently, most existing sequence-based methods only consider contextual features of the sequential neighbors, which are limited to capture spatial information. Based on the recent breakthrough in protein structure prediction by AlphaFold2, we propose an accurate predictor, GraphSite, for identifying DNA-binding residues based on the structural models predicted by AlphaFold2. Here, we convert the binding site prediction problem into a graph node classification task and employ a transformer-based variant model to take the protein structural information into account. By leveraging predicted protein structures and graph transformer, GraphSite substantially improves over the latest sequence-based and structure-based methods. The algorithm is further confirmed on the independent test set of 181 proteins, where GraphSite surpasses the state-of-the-art structure-based method by 16.4% in AUPR and 11.2% in MCC, respectively. We provide the datasets, the predicted structures, and the source codes along with the pre-trained models of GraphSite athttps://github.com/biomed-AI/GraphSite. The GraphSite web server is freely available athttps://biomed.nscc-gz.cn/apps/GraphSite.
Directing an mRNA-LNP vaccine toward lymph nodes improves humoral and cellular immunity against SARS-CoV-2
Authors: Francis David M. , Chen Runqiang , Khorsandzadeh Sahba , Hu Qidong , Lyu Xiaoxuan , Wang Hua , Lim Wan-lin , Sun Haotian , Xie Hui , Shaabani Namir , Ross Russell , Cooley Brian , Ji Henry
Published: August 2021

The exploration and identification of safe and effective vaccines for the SARS-CoV-2 pandemic has captured the world’s attention and remains an ongoing issue in order to protect against emerging variants of concern (VoCs) while generating long lasting immunity. Here, we report the synthesis of a novel messenger ribonucleic acid (mRNA) encoding the spike protein in a lipid nanoparticle formulation (LNP) (STI-7264) that generates robust humoral and cellular immunity following immunization of C57Bl6 mice. In efforts to continually improve immunity, a lymphatic drug delivery device (MuVaxx) was engineered and tested to modulate immune cells at the injection site (epidermis and dermis) and draining lymph node (LN) to elicit adaptive immunity. Using MuVaxx, immune responses were elicited and maintained at a 10-fold dose reduction compared to traditional intramuscular (IM) administration as measured by anti-spike antibodies, cytokine producing CD8 T cells, and neutralizing antibodies against the Washington (Wild Type, WT) and South African (beta) variants. Remarkably, a 4-fold elevated T cell response was observed in MuVaxx administered vaccination as compared to that of IM administered vaccination. Thus, these data support further investigation into STI-7264 and lymphatic mediated delivery using MuVaxx for SARS-CoV-2 and VoCs vaccines.
The white beam station at imaging beamline BL-4, Indus-2
Authors: Agrawal Ashish K. , Singh Balwant , Singhai Payal , Kashyap Yogesh , Shukla Mayank
Published: August 2021

The high flux density of synchrotron white beam offers several advantages in X-ray imaging such as higher resolution and signal-to-noise ratio in 3D/4D micro-tomography, higher frame rate in real-time imaging of transient phenomena, and higher penetration in thick and dense materials especially at higher energies. However, these advantages come with additional challenges to beamline optics, camera and sample due to increased heat load and radiation damage, and to personal safety due to higher radiation dose and ozone gas hazards. In this work, a white beam imaging facility at imaging beamline BL-4, Indus-2, has been developed, while taking care of various instrumental and personal safety challenges. The facility has been tested to achieve 1.5 µm spatial resolution, increased penetration depth up to 900 µm in steel, and high temporal resolutions of ∼10 ms (region of interest 2048 × 2048 pixels) and 70 µs (256 × 2048 pixels). The facility is being used successfully for X-ray imaging, non-destructive testing and dosimetry experiments.
Single-particle cryo-EM: alternative schemes to improve dose efficiency
Authors: Zhang Yue , Lu Peng-Han , Rotunno Enzo , Troiani Filippo , van Schayck J. Paul , Tavabi Amir H. , Dunin-Borkowski Rafal E. , Grillo Vincenzo , Peters Peter J. , Ravelli Raimond B. G.
Published: August 2021

Imaging of biomolecules by ionizing radiation, such as electrons, causes radiation damage which introduces structural and compositional changes of the specimen. The total number of high-energy electrons per surface area that can be used for imaging in cryogenic electron microscopy (cryo-EM) is severely restricted due to radiation damage, resulting in low signal-to-noise ratios (SNR). High resolution details are dampened by the transfer function of the microscope and detector, and are the first to be lost as radiation damage alters the individual molecules which are presumed to be identical during averaging. As a consequence, radiation damage puts a limit on the particle size and sample heterogeneity with which electron microscopy (EM) can deal. Since a transmission EM (TEM) image is formed from the scattering process of the electron by the specimen interaction potential, radiation damage is inevitable. However, we can aim to maximize the information transfer for a given dose and increase the SNR by finding alternatives to the conventional phase-contrast cryo-EM techniques. Here some alternative transmission electron microscopy techniques are reviewed, including phase plate, multi-pass transmission electron microscopy, off-axis holography, ptychography and a quantum sorter. Their prospects for providing more or complementary structural information within the limited lifetime of the sample are discussed.
Circular economy: a conceptual model to measure readiness for manufacturing SMEs
Authors: Thorley John , Garza-Reyes Jose Arturo , Anosike Anthony
Published: August 2021

Purpose

Over the last decade, circular economy (CE) has gathered interest from both industrialists and academics alike. Whilst CE research is widespread in such areas as supply chain and larger organisations, there is limited research into how small to medium enterprises (SMEs) can prepare for adopting CE. There is no comprehensive readiness model for SMEs adopting CE. The purpose of this paper is to explore the literature on change readiness and generate knowledge to fill this gap by developing a conceptual model to measure change readiness for SMEs' adopting CE.

Design/methodology/approach

This study is based on a comprehensive literature review of change readiness models and frameworks. The paper reviews publications from Science Direct, Web of Science, Emerald, Scopus and Google Scholar. The readiness for change models and frameworks from the selected publications are evaluated and synthesised to develop a comprehensive conceptual model for change readiness for SMEs adopting a circular economy.

Findings

A readiness conceptual model is developed by incorporating several factors as precursors to readiness, i.e. individual/collective difference, structural, contextual factors and related barriers. Eleven factors make up the individual/collective difference. Three factors make up the structural and contextual factors.

Practical implications

This paper develops a conceptual model that can aid academics and practitioners in better understanding SMEs readiness to adopt CE.

Originality/value

This paper makes a unique contribution by proposing a comprehensive conceptual model of readiness for SMEs adopting CE.
Does risk matter for executive compensation?
Authors: Aldogan Eklund Mehtap
Published: August 2021

Purpose

The purpose of this study is to examine whether chief executive officer (CEOs) are paid for the systematic and/or unsystematic risks and whether there is any optimum risk premium level in the executive pay.

Design/methodology/approach

Firm and year fixed effect panel data regression was used to estimate the relationship between total CEO compensation and systematic (market) and unsystematic (firm) risks.

Findings

There is no nexus between CEO pay and unsystematic (diversifiable) risk; however, the association between CEO compensation and systematic (undiversifiable) risk is positively significant in line with agency theory. Moreover, it is revealed that this positive relationship has an optimum point (curvilinear).

Research limitations/implications

This paper contributes to the controversial argument in the literature by investigating the situation in the Swiss market. Switzerland is an exemplary country because of its direct democracy (consensus) structure for executive pay. This study is limited by the fact that only total CEO compensation is analyzed.

Practical implications

As a practical implication, it is shown that after the optimal point, the higher compensation does not motivate the CEOs to take higher risks and does not provide the organizations with any additional benefit.

Originality/value

The finding of this study supports agency theory’s risk premium assumption and provides additional evidence to the contradictory results in the literature with a new country setting that has paramount importance in executive compensation phenomena. It is a comparative finding with prior literature also outlines the future research area in the risk and compensation literature.
Mapping “drug places” from below. The lived cities of marginalized drug users
Authors: Germes Mélina , Klaus Luise , Steckhan Svea
Published: August 2021

Purpose

On top of their legal, economic, social and institutional marginalization, marginalized drug users (MDUs) also experience political marginalization: drug policies shape their lives without their political participation. From a scientific as well as a political perspective, the inclusion of their various viewpoints and situated knowledge is a major challenge, and one to which this paper aims to contribute in light of the experiences and imaginaries of MDUs urban spaces in several German cities.

Design/methodology/approach

Following a socio-geographical approach, this paper interrogates how MDUs appropriate and imagine the city, drawing on Lefebvre’sProduction of Spaceand mixing critical cartographic with grounded theory, in the attempt to both understand and reconstruct the world from the situated perspective of MDUs based on their own words, drawings and emotions.

Findings

The narratives and drawings of participants show another cityscape, radically different from the hegemonic discourses and mappings antagonizing MDUs and making their existence a social problem. Space appears as a means of marginalization: there are barely any places that MDUs can legitimately appropriate-least of all so-called “public space.” By contrast, MDUs’ imaginaries of an ideal city would accommodate their existence and address further social justice issues.

Originality/value

The notion of “public places” appears unable to express MDU’s experiences. Instead of focusing on the problem of public spaces, policymakers should tackle the question of placemaking for MDUs beyond the level of solely drug-related places.
From high school to workplace: investigating the effects of soft skills on career engagement through the role of psychological capital in different age groups
Authors: Aryani Farida , Wirawan Hillman , Saman Abdul , Samad Sulaiman , Jufri Muhammad
Published: August 2021

Purpose

This study aims at investigating the indirect effect of soft skills on career engagement through the role of psychological capital (PsyCap) in different age groups. The social cognitive theory (SCT) and job demands-resource model (JD-R) were employed to explain the effect of perceived skill mastery on PsyCap and career engagement.

Design/methodology/approach

The data were collected from 707 high school students, 150 university students and 165 employees using a three-wave data collection technique. This study measured soft skills, PsyCap and career engagement at different age groups (i.e. high school students, university students and employees). The data were analysed using a moderated-mediation technique.

Findings

The results showed that soft skills positively influenced PsyCap and eventually increased career engagement in all age groups. However, the effect was stronger for students (both in high school and university) than employees in the workplaces. Unlike most students, employees related soft skills to performance. Regardless of the effect on performance, students would be more likely than employees to perceive soft skill mastery as a source of efficacy.

Research limitations/implications

First, the education system should direct more attention to developing students' non-cognitive skills. Second, people should understand that their career advancement continues in the workplace context. Organizations can foster employees' soft skills by providing more opportunities to develop new skills.

Originality/value

This study sheds light on the importance of soft skills beyond academic and workplace performance. This study is among the few empirical investigations that reveal career engagement factors across different career development stages.
Measurement and evaluation the impact of perceived healthcare service quality on guest loyalty during COVID-19
Authors: Mohammed Husam Jasim , Mohammed Qasim Ali , Rhima Mustafa Hatwan
Published: August 2021

Purpose

The aim of the study is to investigate the effects of perceived healthcare service quality (human aspects, technical aspects and tangible aspects) on satisfaction and guest loyalty in the hotel industry in the COVID-19 pandemic era.

Design/methodology/approach

A total of 130 guests in the hotel were selected purposively in Iraq. Data from self-administered questionnaires were analyzed through the VB-SEM statistical technique using Smart-PLS software towards testing the hypotheses.

Findings

The findings indicated that perceived service quality influences satisfaction and guest loyalty of guests in the hotel. This study reveals that human aspects, technical aspects and tangible aspects directly positively affect satisfaction and guest loyalty in the hotel industry.

Originality/value

This study highlights that perceived service quality (human aspects, technical aspects and tangible aspects) are vital and practical strategic tools that could be positioned to accelerate guest loyalty in the hotel industry. Furthermore, satisfaction mediates the relationship between human aspects, technical aspects, tangible aspects and guest loyalty.
Stable jump control for the wheel-legged robot based on TMS-DIP model
Authors: Li Xu , Fan Yixiao , Yu Haoyang , Zhou Haitao , Feng Haibo , Fu Yili
Published: August 2021

Purpose

The purpose of this paper is to propose a novel jump control method based on Two Mass Spring Damp Inverted Pendulum (TMS-DIP) model, which makes the third generation of hydraulic driven wheel-legged robot prototype (WLR-3P) achieve stable jumping.

Design/methodology/approach

First, according to the configuration of the WLR, a TMS-DIP model is proposed to simplify the dynamic model of the robot. Then the jumping process is divided into four stages: thrust, ascent, descent and compression, and each stage is modeled and solved independently based on TMS-DIP model. Through WLR-3P kinematics, the trajectory of the upper and lower centroids of the TMS-DIP model can be mapped to the joint space of the robot. The corresponding control strategies are proposed for jumping height, landing buffer, jumping attitude and robotic balance, so as to realize the stable jump control of the WLR.

Findings

The TMS-DIP model proposed in this paper can simplify the WLR dynamic model and provide a simple and effective tool for the jumping trajectory planning of the robot. The proposed approach is suitable for hydraulic WLR jumping control. The performance of the proposed wheel-legged jump method was verified by experiments on WLR-3P.

Originality/value

This work provides an effective model (TMS-DIP) for the jump control of WLR-3P. The results showed that the number of landing shock (twice) and the pitch angle fluctuation range (0.44 rad) of center of mass of the jump control method based on TMS-DIP model are smaller than those based on spring-loaded inverted pendulum model. Therefore, the TMS-DIP model makes the jumping process of WLR more stable and gentler.
Australian market response to COVID-19 as moderated by social media
Authors: Maia Vinicius Mothé , Tommasetti Roberto , Macedo Marcelo Alvaro da Silva
Published: August 2021

Purpose

Emerging as a black swan event that stifled the global economy, COVID-19 is the first social media (SM) pandemic. In an unsocial age due to social distancing, SM relevance is intuitively magnified during a pandemic. This study aims to investigate the direct and moderating impact of Twitter on the Australian stock market during the COVID-19 info-pandemic.

Design/methodology/approach

As a natural experiment, a time-series regression measures the effect of the COVID-19 virus, proxied by the active cases and the marginal impact of SM user attention and sentiment on the Australian stock market.

Findings

Results show that SM user attention and sentiment to COVID-19 related fear topics are significant in explaining market returns and in predicting their volatility. It demonstrates that SM plays a role between COVID-19 and Australian stock market performance by amplifying the pandemic impact.

Originality

The study goes beyond a purely empirical investigation of the catalyst (i.e. the pandemic), thus contributing to current theoretical debates on the impact of SM on investor behaviour.

Practical implications

Policymakers and market participants could benefit from the empirical findings of this research in the case of analogous epidemics.
Refractory serum immunoglobulin M elevation during anti‐interleukin (IL)‐1‐ or IL‐6‐targeted treatment in four patients with Schnitzler syndrome
Authors: Takimoto‐Ito Riko , Kambe Naotomo , Kogame Toshiaki , Otsuka Atsushi , Nomura Takashi , Izawa Kazushi , Tabuchi Yuya , Yoshifuji Hajime , Takeuchi Yohei , Kabashima Kenji
Published: August 2021

Schnitzler syndrome is characterized by chronic urticarial rash, neutrophilic dermal infiltrate, recurrent fever, bone pain, elevated C‐reactive protein, and neutrophilic leukocytosis. The pathophysiology of Schnitzler syndrome is unknown, but it is considered to be an acquired form of an autoinflammatory disease because of the resemblance to clinical phenotypes of cryopyrin‐associated periodic syndrome, in which a gain‐of‐function mutation in NLRP3 causes overexpression of interleukin (IL)‐1β. Schnitzler syndrome is generally accompanied by a monoclonal immunoglobulin (Ig)M gammopathy with a long‐term risk of lymphoproliferation that is possibly associated with an MYD88 mutation. Herein, we present the following four patients with Schnitzler syndrome: a 63‐year‐old woman; a 65‐year‐old man; a 43‐year‐old woman; and a 63‐year‐old woman. Each patient fulfilled the Strasbourg diagnostic criteria, but none of the patients had any mutation in NLRP3 or MYD88 detected in their peripheral blood. Although approved treatment options for Schnitzler syndrome are lacking, our patients were treated with IL‐1‐targeted therapy (anakinra or canakinumab) or anti‐IL‐6 (tocilizumab). The acute inflammatory clinical manifestations improved completely with canakinumab and partially with anakinra and tocilizumab, but the serum IgM levels were gradually increased in all patients, even during treatment. To determine whether treatment with anti‐IL‐1β or IL‐6 prevents conversion to a hematopoietic disorder, further collection of cases and long‐term follow‐up will be needed.
Indecent Disclosures: Anticorruption Reforms and Political Selection
Authors: Szakonyi David
Published: August 2021

Does the passage of anticorruption reforms affect the types of people that want to serve in government? This article evaluates the effects of a common tool to fight corruption—financial disclosures—using data on 25,642 elections in Putin‐era Russia. I argue that financial disclosures function like a personal audit, generating information for journalists and prosecutors to investigate illicit gains earned inside and outside of government. Exploiting staggered elections, I find that requiring financial disclosures leads to roughly 25% fewer incumbents seeking reelection and 10% fewer candidates with suspicious financial histories. Greater media freedom and law enforcement capacity further increase the risk of corruption and tax evasion being uncovered, resulting in even fewer candidacies from those criminally exposed. Increasing transparency changes the incentives for serving in elected office, even in settings where other political motives may be at play.
Testing for Pricing Behavior in the Mortgage Loan Market
Authors: Park Haerang
Published: August 2021

This study examines the pricing behavior of banks in the mortgage loan market. Firstly, the paper compares the loan pricing behavior of banks between two periods, one of which is marked as a more competitive state due to regulatory intervention. Secondly, the paper also test for the stock market reaction to model‐implied collusive profits. Using data from banks in Korea, the paper find that mortgage loan rates are more consistent with cooperative pricing behavior than independent pricing behavior in the period from 2006 to 2012.
Simultaneous feature selection and outlier detection with optimality guarantees
Authors: Insolia Luca , Kenney Ana , Chiaromonte Francesca , Felici Giovanni
Published: August 2021

Biomedical research is increasingly data rich, with studies comprising ever growing numbers of features. The larger a study, the higher the likelihood that a substantial portion of the features may be redundant and/or contain contamination (outlying values). This poses serious challenges, which are exacerbated in cases where the sample sizes are relatively small. Effective and efficient approaches to perform sparse estimation in the presence of outliers are critical for these studies, and have received considerable attention in the last decade. We contribute to this area considering high‐dimensional regressions contaminated by multiplemean‐shift outliersaffecting both the response and the design matrix. We develop a general framework and usemixed‐integer programmingto simultaneously perform feature selection and outlier detection with provably optimal guarantees. We prove theoretical properties for our approach, that is, a necessary and sufficient condition for therobustly strong oracle property, where the number of features can increase exponentially with the sample size; the optimal estimation of parameters; and the breakdown point of the resulting estimates. Moreover, we provide computationally efficient procedures to tune integer constraints and warm‐start the algorithm. We show the superior performance of our proposal compared to existing heuristic methods through simulations and use it to study the relationships between childhood obesity and the human microbiome.
Street vendors in Lima in the time of COVID‐19: Guilty or oppressed?
Authors: Coletto Diego , Jaber Lema , Vanhellemont Linus
Published: August 2021

Key Messages

For many informal workers—including street vendors—staying at home and stopping working during the pandemic cannot be considered feasible options for many reasons.

Analyzing informal street vending activities as a homogeneous phenomenon risks provoking misleading interpretations of street vendors solely as victims or as irresponsible people.

Recognizing there is heterogeneity in street vending helps to illuminate the different social representations, identities, and strategies used by street vendors.
A cultural lens on Yucatec Maya families’ COVID‐19 experiences
Authors: Alcalá Lucía , Gaskins Suzanne , Richland Lindsey E.
Published: August 2021

Health guidance during the COVID‐19 pandemic led families around the world to spend more time isolated together, disrupting leisure activities, schooling, social interactions, and family work (UNICEF, 2021). Using the lens of Yucatec Maya families’ cultural values and practices, semi‐structured interviews were conducted with 18 Yucatec Maya rural women in Mexico (Mage = 32; and for comparison, 13 middle‐class European‐American women (Mage = 41)), with children 6–7 years old, to analyze families’ experiences during the pandemic. Faced with the same isolation as in the United States, our exploratory analysis revealed Maya families experienced external stresses but at the same time were generally comfortable with their children's everyday activities and their social‐emotional well‐being, illuminating consequences of the communities’ cultural theories about development.
Temporal dynamics of free‐living nitrogen fixation in the switchgrass rhizosphere
Authors: Smercina Darian N. , Evans Sarah E. , Friesen Maren L. , Tiemann Lisa K.
Published: August 2021

Free‐living nitrogen fixation (FLNF) represents an important terrestrial N source and is gaining interest for its potential to contribute plant available N to bioenergy cropping systems. Switchgrass, a cellulosic bioenergy crop, may be particularly reliant on FLNF when grown on low N systems, like marginal lands. However, the potential contributions of FLNF to switchgrass as well as the controls on this process are not well understood. In this study, we evaluated drivers of FLNF rates and N‐fixing microbial (diazotrophic) community composition in field‐grown switchgrass systems over two growing seasons with high temporal sampling. We found that climate variables are strong drivers of FLNF rates in switchgrass systems, compared to other environmental and biological factors including soil nutrients and diazotrophic community composition. Increased soil moisture availability generally promoted FLNF rates, but extreme rainfall events were detrimental. These climate‐related responses suggest a potential for loss of FLNF‐derived N contributions under projected climate shifts. We found a significant, but weak correlation between diazotrophic community composition and FLNF rates. We also observed a significant shift in the diazotrophic community composition between 2017 and 2018 and similarly measured a significant difference in FLNF rates between growing seasons. Lastly, we found that seasonal FLNF N contributions, based on measurement with high temporal resolution, has the potential to meet up to 80% of switchgrass N demands suggesting that FLNF measurements extrapolated from fewer time points or locations may underestimate these potential N contributions.
Continuous updating of individual headache forecasting models using Bayesian methods
Authors: Houle Timothy T. , Deng Hao , Tegeler Charles H. , Turner Dana P.
Published: August 2021

Objective

To illustrate the benefits of deploying individual headache forecasting models using continuous updating with Bayesian methods.

Background

The ability to reliably forecast headache attacks within an individual over time would enhance the study of attacks and allow preemptive treatment. However, deploying a suitable forecasting model in a clinical setting will likely involve several unique challenges related to heterogeneity in the predictor weights, limited or sparse data, and the need for a quick “warm‐up.” The use of Bayesian methods offers solutions to each of these specific challenges.

Methods

This was a post hoc analysis of a cohort study of individuals with episodic migraine attacks. Individuals completed daily diaries that allowed the estimation of several forecasting models, each using different types of ancillary information incorporated into formal prior probability distributions. An in silico analysis was conducted that mimicked the deployment of these models in a clinical‐like setting where the parameters of the models were continuously updated and evaluated each day using root mean square error (RMSE).

Results

Individuals (N = 95) were followed for 50 days and contributed 3359 days of nonmissing diary data. During the observation period, there were 1293/3359 (38.5%) days with a headache attack. Self‐reported baseline headache frequency was associated with the corresponding predicted probability of future attacks,r = 0.15–0.39. At Day 25, the correlation between baseline information and predicted attack likelihood wasr = 0.29 (95% CI: 0.09–0.47). Additionally, the use of prior probability distributions for model parameters improved the model fit, especially early in the deployment of the models (e.g., Day 5 RMSE 0.45 vs. 0.43). Models using informative prior probability distributions outperformed the models estimated without this information during the first 42 days of observation, although performance became more similar as more data were collected.

Conclusions

This analysis demonstrates the value of Bayesian methods in using additional available information to improve forecasting model performance, especially early in the deployment of a forecasting model. To obtain the full value of such models or to apply any model in clinical settings, a model with adequate discrimination and calibration will be needed.
High productive machining of C/SiC preceramics
Authors: Grinchuk Pavel S. , Abuhimd Hatem M. , Kiyashko Mikhail V. , Akulich Andrei V. , Stepkin Mikhail O. , Solovei Dmitry V. , Kuznetsova Tatyana A. , Kren Alexander P. , Alshahrani Mohammad S.
Published: August 2021

High productive machining of C/SiC preceramics is investigated in relation to the fabrication of complex‐shaped reaction‐bonded silicon carbide ceramics. Machinability is analyzed at different manufacturing steps of ceramics preparation. Machining after the carbonization step is shown to be the most efficient. Great value of material removal rate of 360 mm3/s is achieved by high productive CNC‐milling of carbonized preceramics at a feed rate of 50 mm/s without any defects upon the processed surfaces, edges, and corners. Diamond tool wears approximately .01% (weight loss per mass of material removed) in the process of green CNC‐milling is two orders lower compared with the milling of sintered ceramics (2.8%). Specifics of surface processing are investigated depending on carbon content in preceramics. The increase of bonding carbon from 8 to 16 vol.% decelerates loose abrasive grinding three times, improves the accuracy of surface leveling, and leads to a change of fracture mechanism. The obtained results can be helpful for the advantageous manufacture of complex‐shaped silicon carbide ceramics.
Viscosity of silica and doped silica melts: evidence for a crossover temperature
Authors: Mauro John C. , Kurkjian Charles R. , Gupta Prabhat K. , Kob Walter
Published: August 2021

Silica is known as the archetypal strong liquid, exhibiting an Arrhenius viscosity curve with a high glass transition temperature and constant activation energy. However, given the ideally isostatic nature of the silica network, the presence of even a small concentration of defects can lead to a significant decrease in both the glass transition temperature and activation energy for viscous flow. To understand the impact of trace level dopants on the viscosity of silica, we measure the viscosity‐temperature curves for seven silica glass samples having different impurities, including four natural and three synthetic samples. Depending on the type of dopant, the glass transition temperature can vary by nearly 300 K. A common crossover is found for all viscosity curves around ~2200–2500 K, which we attribute to a change of the transport mechanism in the melt from being dominated by intrinsic defects at high temperature to dopant‐induced defects at low temperatures.
Government transparency and firm‐level operational efficiency
Authors: Hope Ole‐Kristian , Jiang Shushu , Vyas Dushyantkumar
Published: August 2021

We examine the informational role of governments in the private sector in emerging economies. Using a large sample of private firms, we show that governments’ ability and willingness to collect and disseminate economic information (government transparency) is positively associated with firm‐level operational efficiency and access to external financing. Several cross‐sectional analyses corroborate our main findings. We find that the effect of government transparency is stronger for firms operating in weaker alternative information environments. We also find a reduced effect of government transparency in countries with better‐developed capital markets that facilitate capital allocation and production efficiency. Additional analyses using the World Bank‐supported Open Government Data initiative as a staggered shock to government transparency provide further support to our primary results. Overall, our paper sheds light on the important role played by governments in emerging markets in aggregating and disseminating economic information.
Bowel ischemia as onset of COVID‐19 in otherwise asymptomatic patients with persistently negative swab
Authors: Zamboni Paolo , Bortolotti Daria , Occhionorelli Savino , Traina Luca , Neri Luca Maria , Rizzo Roberta , Gafà Roberta , Passaro Angelina
Published: August 2021

Background

Asymptomatic patients with Severe Acute Respiratory Syndrome Coronavirus 2 (SARS‐CoV‐2) can develop hypercoagulable conditions and acute vascular events. The objective of this study is to determine whether SARS‐CoV‐2 was present in resected specimens from patients with acute bowel ischemia, but asymptomatic for Coronavirus Disease 2019 (COVID‐19) and with persistently real‐time polymerase chain reaction negative pharyngeal swab.

Methods

Three consecutive patients presented severe abdominal symptoms due to extensive ischemia and necrosis of the bowel, with co‐existent thrombosis of abdominal blood vessels. None had the usual manifestations of COVID‐19, and repeated pharyngeal swabs tested negative. They underwent emergency surgery with intestinal resection. Immunohistochemical testing for SARS‐CoV‐2 on resected tissue was performed.

Results

All tested samples were strongly positive for SARS‐CoV‐2.

Conclusions

This is the first case report in which patients with severe intestinal symptoms presented a marked SARS‐CoV‐2 positivity in the resected tissues, without any usual clinical manifestations of COVID‐19. These results suggest that the patients might be infected with SARS‐CoV‐2 presenting acute abdominal distress but without respiratory or constitutional symptoms.