bluuebunny/crossref_metadata_2025 huggingface dataset:
The Mycobacterium tuberculosis sRNA F6 Modifies Expression of Essential Chaperonins, GroEL2 and GroES
Authors: Houghton Joanna , Rodgers Angela , Rose Graham , D’Halluin Alexandre , Kipkorir Terry , Barker Declan , Waddell Simon J. , Arnvig Kristine B.
Published: September 2021

Control of gene expression via small regulatory RNAs (sRNAs) is poorly understood in one of the most successful pathogens,
Mycobacterium tuberculosis
. Here, we present an in-depth characterization of the sRNA F6, including its expression in different infection models and the differential gene expression observed upon deletion of the sRNA.
Spontaneous bladder rupture secondary to posterior urethral valves in a boy with Down syndrome
Authors: Garriboli Massimo , Ibrahim Shimaa , Clothier Joanna
Published: September 2021

We describe a case of a 3-year-old boy with Down syndrome who developed a bladder rupture as a consequence of an undiagnosed posterior urethral valve (PUV). He had a history of urinary tract infections and constipation and was acutely admitted in poor condition and underwent laparotomy that revealed peritoneal sepsis secondary to bladder perforation. Bladder was drained using a suprapubic catheter and the condition of the boy gradually improved. Once stable, a cystourethroscopy confirmed the presence of PUV. Video-urodynamic studies performed at the check cystoscopy showed the bladder to be of reduced compliance (end fill pressure at 100 mL fill 30 cmH2O) with raised voiding pressures (76–100 cmH2O) and significant incomplete bladder emptying. Currently, the patient is doing very well, serum creatinine has normalised, he is infection-free and thriving; his bladder is managed with a vesicostomy.
Retrospective cohort study of new-onset atrial fibrillation in acute pulmonary embolism on prognosis
Authors: Liu Dishiwen , Shi Shaobo , Liu Xin , Ye Tianxin , Wang Linglin , Qu Chuan , Yang Bo , Zhao Qingyan
Published: September 2021

Objectives

To investigate the characteristics of new-onset atrial fibrillation (AF) and its impact on prognosis in acute pulmonary embolism (aPE).

Design

A retrospective cohort study

Setting

The study cohort included patients diagnosed with aPE who were admitted to the Renmin Hospital of Wuhan University from January 2017 to January 2019.

Participants

Patients were ≥18 years of age and hospitalised for aPE.

Outcome measures

AF was diagnosed based on an ECG recording or a Holter monitor during hospitalisation. aPE was diagnosed by CT pulmonary angiography. The prescription was determined from the discharge medication list. All-cause mortality was observed after 6-month follow-up. The logistic regression model and Cox proportional hazards model were used to study the risk factor of the new-onset AF and the predictor of all-cause mortality, respectively.

Results

A total of 590 patients with aPE were enrolled, 23 (3.9%) in the new-onset paroxysmal AF group, 31 (5.3%) in the new-onset persistent AF group and 536 (90.8%) in the sinus rhythm (SR) group. The incidence of the new-onset AF was 9.2% (54/590). A significant difference in age, heart rate, cardiac troponin I ultra, amino-terminal pro-brain natriuretic peptide, D-dimer, left atrial diameter, left ventricular ejection fraction, pulmonary infection, venous thromboembolism, congestive heart failure, chronic cor pulmonale and ischaemic heart disease was found among the three groups (p<0.05). Risk factors for the new-onset AF were massive PE, ischaemic heart disease and congestive heart failure. The survival rate of the paroxysmal and persistent AF group was significantly lower than that of the SR group within 6 months (60.9% and 51.6% vs 88.8%, p<0.001). New-onset persistent AF (OR 2.73; 95% CI 1.28 to 5.81; p=0.009) was an independent predictor affecting the 6-month survival in aPE patients.

Conclusions

Massive PE, ischaemic heart disease and congestive heart failure are high-risk factors which were related to new-onset AF in aPE. New-onset persistent AF was an independent predictor for 6-month all-cause mortality in PE patients.
Strategies to enhance recruitment and consent to intensive care studies: a qualitative study with researchers and patient–public involvement contributors
Authors: Paddock Katie , Woolfall Kerry , Frith Lucy , Watkins Megan , Gamble Carrol , Welters Ingeborg , Young Bridget
Published: September 2021

Objective

Clinical trials and studies in intensive care units (ICUs) have complex consent processes and often encounter problems in recruiting patients. By interviewing research team members about the challenges in critical care research, we aimed to identify strategies to enhance recruitment and consent to ICU studies.

Methods

Semistructured interviews with UK-based researchers (N=17) and patient–public involvement (PPI) contributors (N=8) with experience of ICU studies. Analysis of transcripts of audio-recorded interviews drew on thematic approaches.

Results

Seven themes were identified. Participants emphasised the need for substitute decision-making processes in critical care studies, yet some researchers reported that research ethics committees (RECs) were reluctant to approve such processes. Researchers spoke about the potential benefits of research without prior consent (RWPC) for studies with narrow recruitment windows but believed RECs would not approve them. Participants indicated that the activity of PPI contributors was limited in critical care studies, though researchers who had involved PPI contributors more extensively were clear that their input when designing consent processes was important. Researchers and PPI contributors pointed to resource and staffing limitations as barriers to patient recruitment. Researchers varied in whether and how they used professional consultees as substitute decision-makers, in whether they approached families by telephone to discuss research and in whether they disclosed details of research participation to bereaved relatives.

Conclusion

Critical care research could benefit from RECs having expertise in consent processes that are suited to this setting, better staffing at research sites, more extensive PPI and an evidence base on stakeholder perspectives on critical care research processes. Guidance on professional consultee processes, telephoning relatives to discuss research, RWPC and disclosure of research participation to bereaved relatives could help to harmonise practice in these areas and enhance recruitment and consent to critical care studies.
Effect of virtual reality simulation training on the response capability of public health emergency reserve nurses in China: a quasiexperimental study
Authors: Zhang Dandan , Liao Hongwu , Jia Yitong , Yang Wenren , He Pingping , Wang Dongmei , Chen Yongjun , Yang Wei , Zhang Yin-Ping
Published: September 2021

Objective

To develop a virtual reality simulation training programme, and further verify the effect of the programme on improving the response capacity of emergency reserve nurses confronting public health emergencies.

Design

A prospective quasiexperimental design with a control group.

Participants

A total of 120 nurses were recruited and randomly divided into the control group and the intervention group.

Intervention

Participants underwent a 3-month training. The control group received the conventional training of emergency response (eg, theoretical lectures, technical skills and psychological training), while the intervention group underwent the virtual reality simulation training in combination with skills training. The COVID-19 cases were incorporated into the intervention group training, and the psychological training was identical to both groups. At the end of the training, each group conducted emergency drills twice. Before and after the intervention, the two groups were assessed for the knowledge and technical skills regarding responses to fulminate respiratory infectious diseases, as well as the capacity of emergency care. Furthermore, their pandemic preparedness was assessed with a disaster preparedness questionnaire.

Results

After the intervention, the scores of the relevant knowledge, the capacity of emergency care and disaster preparedness in the intervention group significantly increased (p<0.01). The score of technical skills in the control group increased more significantly than that of the intervention group (p<0.01). No significant difference was identified in the scores of postdisaster management in two groups (p>0.05).

Conclusion

The virtual reality simulation training in combination with technical skills training can improve the response capacity of emergency reserve nurses as compared with the conventional training. The findings of the study provide some evidence for the emergency training of reserve nurses in better response to public health emergencies and suggest this methodology is worthy of further research and popularisation.
Sex as a prognostic factor for mortality in critically ill adults with sepsis: a systematic review and meta-analysis
Authors: Antequera Alba , Lopez-Alcalde Jesus , Stallings Elena , Muriel Alfonso , Fernández Félix Borja , del Campo Rosa , Ponce-Alonso Manuel , Fidalgo Pilar , Halperin Ana Veronica , Madrid-Pascual Olaya , Álvarez-Díaz Noelia , Solà Ivan , Gordo Federico , Urrutia Gerard , Zamora Javier
Published: September 2021

Objective

To assess the role of sex as an independent prognostic factor for mortality in patients with sepsis admitted to intensive care units (ICUs).

Design

Systematic review and meta-analysis.

Data sources

MEDLINE, Embase, Web of Science, ClinicalTrials.gov and the WHO Clinical Trials Registry from inception to 17 July 2020.

Study selection

Studies evaluating independent associations between sex and mortality in critically ill adults with sepsis controlling for at least one of five core covariate domains prespecified following a literature search and consensus among experts.

Data extraction and synthesis

Two authors independently extracted and assessed the risk of bias using Quality In Prognosis Studies tool. Meta-analysis was performed by pooling adjusted estimates. The Grades of Recommendations, Assessment, Development and Evaluation approach was used to rate the certainty of evidence.

Results

From 14 304 records, 13 studies (80 520 participants) were included. Meta-analysis did not find sex-based differences in all-cause hospital mortality (OR 1.02, 95% CI 0.79 to 1.32; very low-certainty evidence) and all-cause ICU mortality (OR 1.19, 95% CI 0.79 to 1.78; very low-certainty evidence). However, females presented higher 28-day all-cause mortality (OR 1.18, 95% CI 1.05 to 1.32; very low-certainty evidence) and lower 1-year all-cause mortality (OR 0.83, 95% CI 0.68 to 0.98; low-certainty evidence). There was a moderate risk of bias in the domain adjustment for other prognostic factors in six studies, and the certainty of evidence was further affected by inconsistency and imprecision.

Conclusion

The prognostic independent effect of sex on all-cause hospital mortality, 28-day all-cause mortality and all-cause ICU mortality for critically ill adults with sepsis was uncertain. Female sex may be associated with decreased 1-year all-cause mortality.

PROSPERO registration number

CRD42019145054.
Primary health care physicians’ perspective on COVID-19 pandemic management in Qatar: a web-based survey
Authors: Ismail Mansoura , Joudeh Anwar , Neshnash Marwa , Metwally Nourhan , Seif Mai Hassan , Al Nuaimi Ahmed , Alsaadi Muna Mehdar , Al Abdulla Samya , Selim Nagah Abdel Aziz
Published: September 2021

Objectives

To assess primary care physicians’ satisfaction towards COVID-19 pandemic management in Qatar and to identify the associated factors with their satisfaction.

Design

A cross-sectional web-based survey conducted from 1 June to 30 July 2020.

Setting

All the 27 public primary healthcare centres in Qatar.

Participants

294 primary care physicians working in the publicly run primary healthcare corporation in Qatar.

Primary outcome measures

Overall satisfaction towards COVID-19 management in Qatar and satisfaction towards each aspect of this management including COVID-19 clinical practice guidelines, psychological support, team dynamics, work safety as well as institutional and governmental regulations.

Results

294 primary care physicians participated in the survey with a response rate of 65%. Overall satisfaction of physicians towards COVID-19 19 management at Primary Health Care Corporation was 77%. The highest satisfaction was towards institutional and governmental support while it was the lowest towards the corporation case definition and management of COVID-19 guidelines. Female physicians were less satisfied with psychological support in comparison to males (64.1% and 51% respectively, p=0.049). Overall satisfaction towards case definition and management of COVID-19 guidelines were strongly correlated with their clarity, updating these guidelines in due time and applicability of the guidelines (r=0.759 P<0.001; r=0.701 P<0.001; r=0.698 P<0.001) respectively, while satisfaction towards work safety was strongly correlated with availability and quality of Personal Protective Equipment provided (r=0.83 P<0.001 and r=0.811 P<0.001 respectively).

Conclusion

Most primary care physicians in Qatar who responded to the survey were satisfied with the COVID-19 guidelines developed rapidly in response to this pandemic. Availability and quality of PPE were a particular concern. The clinicians who were less satisfied were younger and female.
Evidence of health system resilience in Myanmar during Cyclone Nargis: a qualitative analysis
Authors: Grimm Pauline Yongeun , Merten Sonja , Wyss Kaspar
Published: September 2021

Objective

The aim of this study is to improve the understanding of the characteristics of health system resilience in Myanmar’s response to Cyclone Nargis and to explore ways to improve resilience at the system level.

Design and setting

This is an explanatory qualitative study exploring the institutional capacity of resilience in Myanmar’s health system. Analysis proceeded using a data-driven thematic analysis closely following the framework method. This process enabled comparisons and contrasts of key emergent themes between the participants, which later generated key results describing the foundational assets, barriers and opportunities for achieving resilience in Myanmar.

Participants

The study comprised of 12 in-depth interviews conducted with representatives from international organisations and non-governmental organisations (NGOs). The inclusion criteria to recruiting the participants were that they had directly been a part of the Cyclone Nargis response at the time. There was a balanced distribution of participants across UN, bilateral and NGOs, and most of them were either Myanmar citizens or expatriates with extensive working experience based in Myanmar.

Results

Key findings elucidate the characteristics of resilience that have been salient or absent in Myanmar’s response to Cyclone Nargis. Strong social capital and motivation propelled by its deep-rooted culture and religion served as Myanmar’s greatest assets that filled major gaps in the system. Meanwhile, its postcolonial and military legacy posed barriers towards investing in building its long-term foundations towards resilience.

Conclusions

This study revealed that resilience in the health system can be built through strategic investments towards building the foundations of resilience to better prepare for future shocks. In the case of Myanmar, social capital and motivation, which surfaced as its foundational assets, can be channelled into opportunities that can help achieve its long-term health goals, accelerating its journey towards resilience in the health system.
Unequal access and use of contraceptives among parenting adolescent girls in sub-Saharan Africa: a cross-sectional analysis of demographic and health surveys
Authors: Ahinkorah Bright Opoku , Obisesan Matthew Tobiloba , Seidu Abdul-Aziz , Ajayi Anthony Idowu
Published: September 2021

Objective

We examined the divergent patterns, prevalence and correlates of contraceptive use among parenting adolescents in sub-Saharan Africa using the Demographic and Health Survey datasets of 17 countries.

Design

We included a weighted sample of 9488 parenting adolescent girls in our analysis. Current contraceptive use was defined as the use of any methods to delay or avoid getting pregnant at the survey time. We reported the prevalence of any contraceptive use for all countries and used multilevel binary logistic regression analysis to examine the individual and contextual factors associated with contraceptive use.

Outcome measures

Contraceptive use.

Results

We found an overall contraceptive prevalence of 27.12% (CI 27.23% to 28.03%) among parenting adolescent girls in sub-Saharan Africa, ranging from 70.0% (CI 61.76% to 77.16%) in South Africa to only 5.10% (CI 3.04% to 8.45%) in Chad. The prevalence of contraceptive use was lowest in West andCentral Africa, with most countries having less than 20% prevalence. Increasing age (adjusted OR (aOR)=1.46, 95% CI 1.28 to 1.65), being married (aOR=1.63, 95% CI 1.43 to 1.87), having a secondary or higher level of education (aOR=2.72, 95% CI 2.25 to 2.3.27), and media exposure (aOR=1.21, 95% CI 1.08 to 1.36), were associated with higher odds of contraceptive use in the pooled data but preference for a higher number of children (more than five children) (aOR=0.61, 95% CI 0.52 to 0.72) was related to lower likelihood of use. Significant heterogeneity was observed in the country-level disaggregated results.

Conclusion

African countries differ widely when it comes to contraceptive use among parenting adolescent girls, with only three countries having a relatively high prevalence of use. The governments of countries in sub-Saharan Africa, particularly those in West and Central Africa, should invest in expanding access to contraceptives for adolescent mothers to prevent repeat pregnancy and improve the overall well-being of parenting adolescent girls.
Neurosurgeons’ experiences of conducting and disseminating clinical research in low-income and middle-income countries: a reflexive thematic analysis
Authors: Whiffin Charlotte Jane , Smith Brandon George , Esene Ignatius N , Karekezi Claire , Bashford Tom , Mukhtar Khan Muhammad , Hutchinson Peter John , Kolias Angelos G , Fontoura Solla Davi Jorge , Paiva Wellingson S , Figaji Anthony
Published: September 2021

Objectives

Low-income and-middle-income countries (LMICs) are increasing investment in research and development, yet there remains a paucity of neurotrauma research published by those in LMICs. The aim of this study was to understand neurosurgeons’ experiences of, aspirations for, and ability to conduct and disseminate clinical research in LMICs.

Design

This was a two-stage inductive qualitative study situated within the naturalistic paradigm. This study committed to an interpretivist way of knowing (epistemology), and considered reality subjective and multiple (ontology). Data collection used online methods and included a web-based survey tool for demographic data, an asynchronous online focus group and follow-up semistructured interviews. Data were analysed using Braun and Clarke’s Reflexive Thematic Analysis supported by NVivo V.12.

Setting

LMICs.

Participants

In April–July 2020, 26 neurosurgeons from 11 LMICs participated in this study (n=24 in the focus groups, n=20 in follow-up interviews).

Results

The analysis gave rise to five themes: The local landscape; creating capacity; reach and impact; collaborative inquiry; growth and sustainability. Each theme contained an inhibitor and stimulus to neurosurgeons conducting and disseminating clinical research, interpreted as ‘the neurosurgical research potential in LMICs’. Mentorship, education, infrastructure, impact and engagement were identified as specific accelerators. Whereas lack of generalisability, absence of dissemination and dissemination without peer review may desensitise the impact of research conducted by neurosurgeons.

Conclusion

The geographical, political and population complexities make research endeavour challenging for neurosurgeons in LMICs. Yet in spite of, and because of, these complexities LMICs provide rich opportunities to advance global neurosurgery. More studies are required to evaluate the specific effects of accelerators of research conducted by neurosurgeons and to understand the effects of desensitisers on high-quality, high-impact clinical research.
Mental health and well-being of older adults living with HIV in sub-Saharan Africa: a systematic review
Authors: Mwangala Patrick Nzivo , Mabrouk Adam , Wagner Ryan , Newton Charles R J C , Abubakar Amina A
Published: September 2021

Objective

In this systematic review, we aimed to summarise the empirical evidence on common mental disorders (CMDs), cognitive impairment, frailty and health-related quality of life (HRQoL) among people living with HIV aged ≥50 years (PLWH50 +) residing in sub-Saharan Africa (SSA). Specifically, we document the prevalence and correlates of these outcomes.

Design, data sources and eligibility criteria

The following online databases were systematically searched: PubMed, CINAHL, PsycINFO, Embase and Scopus up to January 2021. English-language publications on depression, anxiety, cognitive function, frailty and quality of life among PLWH50+ residing in SSA were included.

Data extraction and synthesis

We extracted information, including study characteristics and main findings. These were tabulated, and a narrative synthesis approach was adopted, given the substantial heterogeneity among included studies.

Results

A total of 50 studies from fifteen SSA countries met the inclusion criteria. About two-thirds of these studies emanated from Ethiopia, Uganda and South Africa. Studies regarding depression predominated (n=26), followed by cognitive impairment (n=13). Overall, PLWH50+ exhibited varying prevalence of depression (6%–59%), cognitive impairments (4%–61%) and frailty (3%–15%). The correlates of CMDs, cognitive impairment, frailty and HRQoL were rarely investigated, but those reported were sociodemographic variables, many of which were inconsistent.

Conclusions

This review documented an increasing number of published studies on HIV and ageing from SSA. However, the current evidence on the mental and well-being outcomes in PLWH50+ is inadequate to characterise the public health dimension of these impairments in SSA, because of heterogeneous findings, few well-designed studies and substantial methodological limitations in many of the available studies. Future work should have sufficiently large samples of PLWH50+, engage appropriate comparison groups, harmonise the measurement of these outcomes using a standardised methodology to generate more robust prevalence estimates and confirm predictors.

PROSPERO registration number

CRD42020145791.
Effect of a Mediterranean diet intervention on gastrointestinal function in Parkinson’s disease (the MEDI-PD study): study protocol for a randomised controlled trial
Authors: Rusch Carley , Beke Matthew , Tucciarone Lily , Dixon Katherine , Nieves Carmelo , Mai Volker , Stiep Tamara , Tholanikunnel Tracy , Ramirez-Zamora Adolfo , Hess Christopher W , Langkamp-Henken Bobbi
Published: September 2021

Introduction

Constipation is a common and sometimes debilitating non-motor symptom of Parkinson’s disease (PD) that can result in intestinal inflammation and microbial dysbiosis. The Mediterranean diet, rich in fermentable fibres and anti-inflammatory phenolic compounds, is associated with reduced risk of developing PD and slower progression of parkinsonism. The Mediterranean diet is often recommended for people with PD; however, no studies to date examine this diet as a therapeutic intervention to modulate gastrointestinal (GI) dysfunction.

Methods and analysis

This is a randomised, controlled, parallel study. During a 2-week run-in, participants with PD and constipation symptoms (n=52) will undergo baseline nutritional and neurological assessments and provide a stool sample. Participants will be stratified by sex and Hoehn and Yahr stage and randomised to follow standard of care for constipation (control) or standard of care plus a Mediterranean diet (intervention) for 8 weeks. A study dietitian will provide dietary instruction and weekly follow-up via telephone to both groups to support adherence and monitor adverse events. Questionnaires will assess dietary intake and GI function including stool frequency, form, symptoms and laxative usage. Measurements completed at baseline will be repeated at 4 and 8 weeks of the intervention. The primary outcome is to evaluate the difference between mean change (final–baseline) in Gastrointestinal Symptom Rating Scale (GSRS) constipation syndrome scores for the control versus intervention groups. Secondary outcomes will assess stool frequency and form, weekly GSRS syndrome scores, digestive quality of life, laxative usage, faecal microbial communities and inflammatory markers, anxiety, depression, quality life, body weight and composition, dietary fibre intake and Mediterranean diet adherence.

Ethics and dissemination

The study has received University of Florida Institutional Review Board-01 approval (IRB202001333). Findings will be disseminated via conference presentations, lectures and peer-reviewed publications.

Trial registration number

NCT04683900.
Transition to clinical practice during the COVID-19 pandemic: a qualitative study of young doctors’ experiences in Brazil and Ireland
Authors: Montagna Erik , Donohoe Jessica , Zaia Victor , Duggan Eileen , O'Leary Paula , Waddington John , O'Tuathaigh Colm
Published: September 2021

Objectives

To explore and compare the perspectives of junior doctors in Brazil and Ireland regarding transition and professional socialisation during the COVID-19 pandemic, with the purpose of identifying better ways to support doctors as they assume their new professional role.

Design

27 semistructured interviews. Transcripts were analysed using qualitative thematic analysis. Cruess’ framework of professional socialisation in medicine supported the interpretation of these data.

Setting

Public health hospitals across four Brazilian states (Santa Catarina, São Paulo, Ceará, Paraíba) and County Cork in the South of Ireland.

Participants

Twenty-seven male and female medical junior doctors who had graduated between November 2019 and April 2020.

Results

Fourteen Brazilian and 13 Irish junior doctors were interviewed for this study. Entry to clinical practice during the pandemic had a significant impact on factors influencing the professional socialisation of junior doctors. This impact was reflected across the following six thematic areas: lack of preparedness; disrupted trajectory of role adaptation; fewer opportunities for experiential learning; solidarity and isolation; altered interactions with patients; challenges to health and well-being.

Conclusions

Transition to clinical practice is an important stage in junior doctors’ professional socialisation and identity formation. The COVID-19 pandemic created the opportunity for medical graduates to enter the workforce earlier than usual. Entering the workforce during this period created a lack of confidence among junior doctors concerning the boundaries of their new role and responsibilities, while simultaneously disrupting their social integration. Priorities to mitigate the impact of COVID-19 and future pandemics on this transition are presented.
A fibre-based modelling technique for the seismic analysis of steel–concrete composite shear walls
Authors: Emrani Seyed MohammadReza , Epackachi Siamak , Tehrani Payam , Imanpour Ali
Published: September 2021

Steel–concrete composite shear wall offers a favourable lateral strength and deformation ductility for seismic applications while significantly shortening the project schedule through eliminating the use of formworks and taking advantage of modular construction methodology. This paper presents a fibre-based modelling technique for simulation of the cyclic nonlinear response of composite walls by taking advantage of existing reinforced concrete and steel plate shear wall models. The improved modelling technique for cyclic analysis of composite walls that benefits from the macro models available for steel and concrete shear walls is introduced. The model is validated using experimental test data from 20 wall specimens. A sensitivity analysis is performed to examine the influence of various geometrical and material properties using the proposed modelling technique. A step-by-step modelling recommendation is finally proposed. The results show that the proposed modelling technique can efficiently be used to reproduce the nonlinear cyclic response of composite walls.
Higher-derivative Lorentz-breaking dispersion relations: a thermal description
Authors: Araújo Filho A. A. , Petrov A. Yu.
Published: September 2021

This paper is devoted to study the thermal aspects of a photon gas within the context of Planck-scale-modified dispersion relations. We study the spectrum of radiation and the correction to theStefan–Boltzmannlaw in different cases when the Lorentz symmetry is no longer preserved. Explicitly, we examine two models within the context of CPT-even and CPT-odd sectors respectively. To do so, three distinct scenarios of the Universe are considered: the Cosmic Microwave Background (CMB), the electroweak epoch, and the inflationary era. Moreover, the equations of state in these cases turn out to display a dependence on Lorentz-breaking parameters. Finally, we also provide for both theories the analyses of the Helmholtz free energy, the mean energy, the entropy and the heat capacity.
Two Fibonacci operational matrix pseudo-spectral schemes for nonlinear fractional Klein–Gordon equation
Authors: Youssri Y. H.
Published: September 2021

This paper is devoted to developing spectral solutions for the nonlinear fractional Klein–Gordon equation. The typical collocation method and the tau method are employed for obtaining the desired numerical solutions. In order to do this, a new operational matrix of fractional derivatives of Fibonacci polynomials is established. The idea behind the derivation of this matrix is based on utilizing the connection formula between the Fibonacci and Chebyshev polynomials. The introduced operational matrix is used along with the weighted residual quadrature spectral method and the collocation method to convert the nonlinear fractional Klein–Gordon equation into a system of algebraic equations. By solving the resulting system, we obtain a semi-analytic solution. The convergence and error analysis of the method are discussed. Some numerical results and discussions are presented aiming to illustrate the wide applicability and accuracy of the proposed algorithms.
Boson stars and oscillatons: A review
Authors: Visinelli Luca
Published: September 2021

Compact objects occupy a pivotal role in the exploration of Nature. The interest spans from the role of compact objects in astrophysics to their detection through various methods (gravitational waves interferometry, microlensing, imaging). While the existence of compact objects made of fermions (neutron stars and white dwarfs) has been assessed, a parallel search for localized solitons made of bosons is ongoing, stemming from Wheeler’s original proposal of electromagnetic “geons”. Boson fields can clump up and form compact objects such as boson stars (for complex scalar fields), oscillons and oscillatons (for real scalar fields), or Proca stars (for massive vector fields), which can show up in searches as black hole mimickers, dark matter sources, and a variety of other phenomena. I review some crucial properties of these bosonic systems, including recent progress in the field.
Hearts of Darkness: The inside out probing of black holes
Authors: Carballo-Rubio Raúl , Di Filippo Francesco , Liberati Stefano
Published: September 2021

Classical black holes shield us from the singularities that inevitably appear in general relativity. Singularity regularization being one of the main landmarks for a successful theory of quantum gravity, quantum black holes are not obliged to hide their inner core from the outside world. Notwithstanding the aforesaid, it is often implicitly assumed that quantum gravity effects must remain confined to black hole interiors. In this essay, we argue in the opposite direction, discussing theoretical evidence for the existence of strong correlations between the physics inside and outside nonsingular black holes. We conclude that astronomical tests of the surroundings of black holes can provide invaluable information about their so-far unexplored interiors.
Measuring the Green Infrastructure Resilience in Turkey
Authors: KARABAKAN Berfin , MERT Yelda
Published: September 2021

Cities today face significant difficulties and even risks due to the negative effects of climate change, uncontrolled urbanization, and rapid population growth. Many urban scenarios are being developed to mitigate potential risks and threats. One branch of these scenarios is built upon the concept of sustainability, for which the notion of “resilience” is of utmost importance. It is this notion of resilience that was examined in this study, based on the case of socio-ecological system features of Edremit, Van, Turkey. These features were evaluated in terms of changes that will potentially take place, and the analysis for this was performed using the Green Infrastructure Spatial Planning (GISP) method. In this approach, green infrastructure benefit criteria are mapped in the Geographic Information System (GIS) environment and various conclusions are drawn from the evaluation of these maps. The results of the study show that the green infrastructure systems of Edremit play an important role in providing a certain degree of resilience. It was, therefore, revealed as part of this study that measuring and evaluating the resilience properties of different cities is important. Also, urban policies and spatial strategies should be defined considering local characteristics and values as there is no one-size-fits-all solution in this regard.
Thin-section detrital zircon geochronology mitigates bias in provenance investigations
Authors: Zutterkirch Isabel C. , Kirkland Christopher L. , Barham Milo , Elders Chris
Published: September 2021

Detrital zircon U–Pb geochronology has enabled advances in the understanding of sediment provenance, transportation pathways, and the depositional age of sedimentary packages. However, sample selection and processing can result in biasing of detrital zircon age spectra. This paper presents a novel approach using
in situ
detrital zircon U–Pb measurements on thin-sections to provide greater confidence in maximum depositional ages and provenance interpretations. New U–Pb age data of 310 detrital zircon grains from 16 thin-sections of the Triassic Mungaroo Formation from two wells in the Northern Carnarvon Basin, Australia, are presented. Whilst detrital zircon age modes are consistent with previous work, there are some differences in the relative proportions of age modes, which are partly attributed to a lack of small grains in hand-picked grain mounts. The relative sample bias is quantified via grain size comparison of dated zircon (in thin-sections or hand-picked mounts) relative to all zircons identified in bulk-mounts and thin-sections. The youngest age mode (
c.
320–195 Ma) is consistent with an active margin to the north. The dated zircons reveal a single grain defined maximum depositional age of 197 Ma for the upper part of the Mungaroo Formation, suggesting deposition may have continued into the Early Jurassic.

Supplementary material: Additional figures, tables, datasets and programming scripts are available at
https://doi.org/10.6084/m9.figshare.c.5628911
geoGAT: Graph Model Based on Attention Mechanism for Geographic Text Classification
Authors: Jing Weipeng , Song Xianyang , Di Donglin , Song Houbing
Published: September 2021

In the area of geographic information processing, there are few researches on geographic text classification. However, the application of this task in Chinese is relatively rare. In our work, we intend to implement a method to extract text containing geographical entities from a large number of network texts. The geographic information in these texts is of great practical significance to transportation, urban and rural planning, disaster relief, and other fields. We use the method of graph convolutional neural network with attention mechanism to achieve this function. Graph attention networks (GAT) is an improvement of graph convolutional neural networks (GCN). Compared with GCN, the advantage of GAT is that the attention mechanism is proposed to weight the sum of the characteristics of adjacent vertices. In addition, We construct a Chinese dataset containing geographical classification from multiple datasets of Chinese text classification. The Macro-F Score of the geoGAT we used reached 95% on the new Chinese dataset.
How to Train Your Quadrotor: A Framework for Consistently Smooth and Responsive Flight Control via Reinforcement Learning
Authors: Mysore Siddharth , Mabsout Bassel , Saenko Kate , Mancuso Renato
Published: September 2021

We focus on the problem of reliably training Reinforcement Learning (RL) models (agents) for stable low-level control in embedded systems and test our methods on a high-performance, custom-built quadrotor platform. A common but often under-studied problem in developing RL agents for continuous control is that the control policies developed are not always smooth. This lack of smoothness can be a major problem when learning controllers as it can result in control instability and hardware failure.

Issues of noisy control are further accentuated when training RL agents in simulation due to simulators ultimately being imperfect representations of reality—what is known as the
reality gap
. To combat issues of instability in RL agents, we propose a systematic framework, REinforcement-based transferable Agents through Learning (RE+AL), for designing simulated training environments that preserve the quality of trained agents when transferred to real platforms. RE+AL is an evolution of the Neuroflight infrastructure detailed in technical reports prepared by members of our research group. Neuroflight is a state-of-the-art framework for training RL agents for low-level attitude control. RE+AL improves and completes Neuroflight by solving a number of important limitations that hindered the deployment of Neuroflight to real hardware. We benchmark RE+AL on the NF1 racing quadrotor developed as part of Neuroflight. We demonstrate that RE+AL significantly mitigates the previously observed issues of smoothness in RL agents. Additionally, RE+AL is shown to consistently train agents that are flight capable and with minimal degradation in controller quality upon transfer. RE+AL agents also learn to perform better than a tuned PID controller, with better tracking errors, smoother control, and reduced power consumption. To the best of our knowledge, RE+AL agents are the first RL-based controllers trained in simulation to outperform a well-tuned PID controller on a real-world controls problem that is solvable with classical control.
Research Progress and Challenges on Application-Driven Adversarial Examples: A Survey
Authors: Jiang Wei , He Zhiyuan , Zhan Jinyu , Pan Weijia , Adhikari Deepak
Published: September 2021

Great progress has been made in deep learning over the past few years, which drives the deployment of deep learning–based applications into cyber-physical systems. But the lack of interpretability for deep learning models has led to potential security holes. Recent research has found that deep neural networks are vulnerable to well-designed input examples, called
adversarial examples
. Such examples are often too small to detect, but they completely fool deep learning models. In practice, adversarial attacks pose a serious threat to the success of deep learning. With the continuous development of deep learning applications, adversarial examples for different fields have also received attention. In this article, we summarize the methods of generating adversarial examples in computer vision, speech recognition, and natural language processing and study the applications of adversarial examples. We also explore emerging research and open problems.
Towards an Integrated Vehicle Management System in DriveOS
Authors: Sinha Soham , West Richard
Published: September 2021

Modern automotive systems feature dozens of electronic control units (ECUs) for chassis, body and powertrain functions. These systems are costly and inflexible to upgrade, requiring ever increasing numbers of ECUs to support new features such as advanced driver assistance (ADAS), autonomous technologies, and infotainment. To counter these challenges, we propose DriveOS, a safe, secure, extensible, and timing-predictable system for modern vehicle management in a centralized platform. DriveOS is based on a separation kernel, where timing and safety-critical ECU functions are implemented in a real-time OS (RTOS) alongside non-critical software in Linux or Android. The system enforces the separation, or partitioning, of both software and hardware among different OSes.

DriveOS runs on a relatively low-cost embedded PC-class platform, supporting multiple cores and hardware virtualization capabilities. Instrument cluster, in-vehicle infotainment and advanced driver assistance system services are implemented in a Yocto Linux guest, which communicates with critical real-time services via secure shared memory. The RTOS manages a real-time controller area network (CAN) interface that is inaccessible to Linux services except via well-defined and legitimate communication channels. In this work, we integrate three Qt-based services written for Yocto Linux, running in parallel with a real-time longitudinal controller task and multiple CAN bus concentrators, for vehicular sensor data processing and actuation. We demonstrate the benefits and performance of DriveOS with a hardware-in-the-loop CARLA simulation using a real car dataset.
Structured Proofs for Adversarial Cyber-Physical Systems
Authors: Bohrer Rose , Platzer André
Published: September 2021

Many cyber-physical systems (CPS) are safety-critical, so it is important to formally verify them, e.g. in formal logics that show a model’s correctness specification
always
holds.
Constructive Differential Game Logic
(
CdGL
) is such a logic for (constructive) hybrid games, including hybrid systems. To overcome undecidability, the user first writes a proof, for which we present a proof-checking tool.

We introduce
Kaisar
, the first language and tool for
CdGL
proofs, which until now could only be written by hand with a low-level proof calculus. Kaisar’s
structured proofs
simplify challenging CPS proof tasks, especially by using programming language principles and high-level stateful reasoning. Kaisar exploits
CdGL
’s constructivity and refinement relations to build proofs around models of game strategies. The evaluation reproduces and extends existing case studies on 1D and 2D driving. Proof metrics are compared and reported experiences are discussed for the original studies and their reproductions.
Verified Lustre Normalization with Node Subsampling
Authors: Bourke Timothy , Jeanmaire Paul , Pesin Basile , Pouzet Marc
Published: September 2021

Dataflow languages allow the specification of reactive systems by mutually recursive stream equations, functions, and boolean activation conditions called clocks. Lustre and Scade are dataflow languages for programming embedded systems. Dataflow programs are compiled by a succession of passes. This article focuses on the normalization pass which rewrites programs into the simpler form required for code generation.

Vélus is a compiler from a normalized form of Lustre to CompCert’s Clight language. Its specification in the Coq interactive theorem prover includes an end-to-end correctness proof that the values prescribed by the dataflow semantics of source programs are produced by executions of generated assembly code. We describe how to extend Vélus with a normalization pass and to allow subsampled node inputs and outputs. We propose semantic definitions for the unrestricted language, divide normalization into three steps to facilitate proofs, adapt the clock type system to handle richer node definitions, and extend the end-to-end correctness theorem to incorporate the new features. The proofs require reasoning about the relation between static clock annotations and the presence and absence of values in the dynamic semantics. The generalization of node inputs requires adding a compiler pass to ensure the initialization of variables passed in function calls.
Section 230 and a tragedy of the commons
Authors: Cusumano Michael A.
Published: September 2021

The dilemma of social media platforms.
HOPX+ injury-resistant intestinal stem cells drive epithelial recovery after severe intestinal ischemia
Authors: Stewart Amy Stieler , Schaaf Cecilia Renee , Luff Jennifer A. , Freund John M. , Becker Thomas C. , Tufts Sara R. , Robertson James B. , Gonzalez Liara M.
Published: September 2021

This paper supports that rISCs are resistant to ischemic injury and likely an important source of cellular renewal following near-complete epithelial loss. Furthermore, we have evidence that HOPX controls ISC activity state and may be a critical signaling pathway during ISC-mediated repair. Finally, we use multiple novel methods to evaluate ISCs in a translationally relevant large animal model of severe intestinal injury and provide evidence for the potential role of rISCs as therapeutic targets.
The role of extracellular vesicles in traumatic brain injury-induced acute lung injury
Authors: Zhang Chao-Nan , Li Fan-Jian , Zhao Zi-Long , Zhang Jian-Ning
Published: September 2021

Acute lung injury (ALI), a common complication after traumatic brain injury (TBI), can evolve into acute respiratory distress syndrome (ARDS) and has a mortality rate of 30%–40%. Secondary ALI after TBI exhibits the following typical pathological features: infiltration of neutrophils into the alveolar and interstitial space, alveolar septal thickening, alveolar edema, and hemorrhage. Extracellular vesicles (EVs) were recently identified as key mediators in TBI-induced ALI. Due to their small size and lipid bilayer, they can pass through the disrupted blood-brain barrier (BBB) into the peripheral circulation and deliver their contents, such as genetic material and proteins, to target cells through processes such as fusion, receptor-mediated interactions, and uptake. Acting as messengers, EVs contribute to mediating brain-lung cross talk after TBI. In this review, we aim to summarize the mechanism of EVs in TBI-induced ALI, which may provide new ideas for clinical treatment.
Ganglion cells in larval zebrafish retina integrate inputs from multiple cone types
Authors: Connaughton V. P. , Nelson R.
Published: September 2021

Ganglion cells in larval zebrafish retina have complex spectral responses driven by seven different cone opsin types. UV cone inputs are significant and excitatory to ganglion cells, whereas green and blue cone inputs favor inhibition. Most dramatic are the pentachromatic cells. These responses were identified at 5–6 days after fertilization, reflecting an impressive level of color processing not seen in older fish or mammals.
Transient peripheral vestibular hypofunction measured with vestibular short-latency evoked potentials following noise exposure in rats
Authors: Stewart Courtney E. , Bauer David S. , Altschuler Richard A. , King William Michael
Published: September 2021

This is the first study to show a temporary noise-induced peripheral vestibular hypofunction that recovers following exposure to continuous noise.