bluuebunny/crossref_metadata_2025 huggingface dataset:
01 The effects of a leaflet-based intervention, ‘hypos can strike twice’, on recurrent hypoglycaemic attendances by ambulance services: a non-randomised stepped wedge study
Authors: Botan Vanessa , Law Graham R , Laparidou Despina , Rowan Elise , Smith Murray D , Ridyard Colin , Brewster Amanda , Spaight Robert , Spurr Keith , Mountain Pauline , Dunmore Sally , James June , Roberts Leon , Khunti Kamlesh , Siriwardena Aloysius Niroshan
Published: August 2021

Background

Hypoglycaemia is a common complication of diabetes therapy needing prompt recognition and treatment. It often results in ambulance attendance incurring health services costs and patient morbidity. Patient education is important for maintaining glycaemic control and preventing recurrent hypoglycaemia. We aimed to investigate the effect of an intervention in which ambulance staff were trained to provide advice supported by a booklet – ‘Hypos can strike twice’- issued following a hypoglycaemic event to prevent future attendances.

Methods

We used a non-randomised stepped wedge-controlled design. The intervention was introduced at different times (steps) in different areas (clusters) of operation of East Midlands Ambulance Service NHS Trust (EMAS). During the first step (T0) no clusters were exposed to the intervention and during the last step (T3) all clusters were exposed. The main outcome was the number of unsuccessful ambulance attendances (i.e. attendances followed by a repeat attendance). Data were analysed using a general linear mixed model (GLMM) and an interrupted-time series analysis (ITSA).

Results

The study included 4825 patients (mean age= 65.42, SD=19.42; 2166 females) experiencing hypoglycaemic events attended by EMAS. GLMM indicated a reduction in the number of unsuccessful attendances in the final step of the intervention when compared to the first (OR: 0.50, 95%CI: 0.33-0.76, p=0.001). ITSA indicated a significant decrease in repeat ambulance attendances for hypoglycaemia – relative to the pre-intervention trend (p=0.008). The hypoglycaemia care bundle (i.e. blood glucose recorded before and after treatment for hypoglycaemia) was delivered in 66% of attendances during the intervention period, demonstrating a significant level of practice change (χ2=30.16, p<0.001).

Conclusions

The ‘Hypos can strike twice’ intervention had a positive effect on reducing numbers of repeat attendances for hypoglycaemia and in achieving the care bundle. The study supports the use of informative booklets by ambulance clinicians to prevent future attendances for recurrent hypoglycaemic events.
02 Leveraging paramedic data to investigate the effect of COVID-19 on community opioid overdoses
Authors: Smith J Chris , Burr Wesley
Published: August 2021

Background

Opioid overdoses in Canada have shown dramatic increases over recent years, despite significant investments in harm reduction. Most community monitoring currently relies on emergency department and coroner data. Our team has previously shown that paramedic data can be a useful addition to the current metrics as paramedics regularly interact with opioid overdose patients. This study examines paramedic data to investigate the changes to community opioid overdoses in the era of COVID-19 to better support our strategic partners in their battle against the opioid crisis.

Methods

The electronic ambulance call report database of Peterborough Paramedics (Ontario, Canada) was examined. De-identified records for patients from 2017-2020 with documented problem codes of ‘Opioid Overdose’ were extracted. Patients receiving paramedic naloxone were also included. The data was cleaned and analysed, and incomplete records were removed. Statistical models including chi-squared tests of goodness-of-fit and post hoc pairwise t-tests were applied to the data. Ethics approval for this study was granted by the Trent University’s Research Ethics Board.

Results

788 opioid overdoses were identified out of 72,737 patients. There were 263 opioid overdoses found in 2020 representing 1.4% patients, a significant increase from 2017-2019 (p value: 0.006). The proportion of patients receiving paramedic naloxone was significantly increased from previous years (p value: 0.005) while bystander naloxone administration was significantly decreased (p value 0.002). Age, gender, and pick-up location types were not significantly different between 2020 and previous years.

Conclusion

Despite reduced overall call volumes in 2020, paramedics observed an increase in opioid overdoses. The increase in paramedic naloxone administration and decrease in bystander naloxone administration may indicate changes in usage practices of community opioid users or an instability in the drug supply. These factors must be considered in future opioid harm reduction strategies and public health COVID-19 containment measures.
PP29 Improving buckle up in EMS study (iBEST)
Authors: Thavaravej Maneeporn , Rojanasarntikul Dhanadol
Published: August 2021

Background

According to NHTSA (National Highway Traffic Safety Administration), data collected from 1992-2011 showed that 84 percent of EMS provider was not restrained while working; increasing the severity of injury when an ambulance crashes or abruptly stop.

Objectives

To increase the awareness of EMS providers focusing on safety belt usage during their work.

Method

The study design is a prospective study including fifteen of physicians, nurses, paramedics, ambulance driver, and nurse aid from King Chulalongkorn Memorial Hospital, whom went on duty from April to October 2020. The collected data includes demographic data, occupation and its safety, reasons for not using seat belt. The data related to seat belt usage collected were then described and analysed by Mixed-effects Poisson Regression method and interpreted as Incident Rate Ratio (IRR) with 95% confidence interval (95% CI) and p-value.

Result

3 out of 15 (20%) did not use seat belt in the period before warning stickers were posted in the ambulance. When compared to 1 month after warning stickers were posted, the number of sample using seatbelt while working/travelling in the ambulance elevated to 11 out of 15 (73.33%) [IRR (95%CI) =3.66 (95% CI: 1.02, 13.13), p = 0.046].While at 3 months and 6 months, 10 out of 15 (66.77%) and 6 out of 15 (40%) still adhere to seat belt use, respectively. There is no statistical significance with the rate of seatbelt usage comparing between one, three, and six months after the warning stickers were posted. The most common reason for not using seatbelt is 1) seat cover covering the seatbelt 2) obstructing work 3) cannot reach equipment.

Conclusion

Warning stickers posted in the ambulance can increase awareness for seatbelt use of King Chulalongkorn Hospital’s EMS personnel while working.
PP35 The acceptability and safety of video triage for ambulance service patients and clinicians during the covid-19 pandemic: a service evaluation
Authors: Bell Fiona , Pilbery Richard , Connell Rob , Fletcher Dean , Leatherland Tracy , Cottrell Linda , Webster Peter
Published: August 2021

Introduction

In response to anticipated challenges with urgent and emergency healthcare delivery during the early part of the COVID-19 pandemic, Yorkshire Ambulance Service NHS Trust (YAS) introduced video call technology to supplement remote triage and ‘hear and treat’ consultations as a pilot project in the Emergency Operations Centre (EOC). We aimed to investigate patient and staff acceptability of video triage, and the safety of the decision-making process.

Methods

This service evaluation utilised a mixture of routine 999 call and bespoke data collection from participating clinicians who logged calls they both attempted and undertook. We sent postal surveys to a group of patients who were recipients of a video triage.

Results

Between 27th March 2020 and 25th August 2020 clinicians documented 1073 video triage calls. A successful video triage call was achieved in 641 (59.7%) of cases. Clinical staff reported that video triage improved clinical assessment and decision making compared to telephone alone, and found the technology accessible for patients. Patients who received a video triage call and responded to the survey (40/201, 19.9%) viewed the technology, the ambulance staff and the care planning favourably.

Callers receiving video triage that ended with a disposition of ‘hear and treat’, had a lower rate of re-contacting the service within 24 hours compared to callers that received clinical support desk telephone triage alone (16/212, 7.5% vs 2508/14349, 17.5% respectively.)

Conclusion

In this single NHS Ambulance Trust evaluation, the use of video triage for low acuity calls appeared to be safe, with low rates of recontact and high levels of patient and clinician satisfaction compared to standard telephone triage. However, video triage is not always appropriate or acceptable to patients and technical issues were not uncommon.
PP40 Pre-hospital and emergency department analgesia for paediatric trauma – a survey of UK trauma centres and ambulance services supports consideration of alternatives such as ketamine
Authors: Fish David , Bell Fiona , O’Connell Clare , Walker Alison , Evans Laura , Ramlakhan Shammi
Published: August 2021

Background

Studies have found that pre-hospital and emergency department (ED) analgesia for children is sub-optimal. In the pre-hospital setting, barriers include limited parenteral routes, education or clinical experience and practice legislation restricting the use of opioids by paramedics. Ketamine is safe and effective with multiple administration routes. It is not bound by the controlled drugs limitations in the pre-hospital setting, and is familiar to pre-hospital and ED practitioners.

Methods

Questionnaires were sent to all UK Ambulance Service Medical Directors and Paediatric Major Trauma Centres to establish current use of parenteral analgesics, and acceptability of alternatives in pre-hospital care such as ketamine. Descriptive analysis was undertaken.

Results

Intranasal opiates were the first line parenteral analgesics in injured children in all EDs. Frequent shortages of IN diamorphine resulted in more variability of second line choices, with 40% opting for another opioid. 96% of EDs would support the use of ketamine by pre-hospital clinicians, although concerns regarding inappropriate (IV) use and use by technician crews were raised. Most ED clinicians were unaware of the limited analgesic choices available to paramedics, with many suggesting alternative opiates as well as ketamine.

All ambulance service directors recognised the need for alternative analgesics being made available. Without legislative changes, inhaled/IN agents or oral opiates were the only current options. All services were supportive of research to explore the use of ketamine by paramedics for injured children.

Conclusions

There is support for the addition of IN ketamine into paramedics’ repertoire of analgesics and recognition of potential benefit. However, there is a lack of experience and evidence around its use, thus warranting research to consider the impact on analgesic timeliness, adequacy and effectiveness. An analgesia ‘system of care’ which integrates pre- and in-hospital practice would be facilitated by the use of medicines effective in managing pain and familiar to practitioners in both settings.
Fluid challenge and balloon occlusion testing in patients with atrial septal defects
Authors: D’Alto Michele , Constantine Andrew , Chessa Massimo , Santoro Giuseppe , Gaio Gianpiero , Giordano Mario , Romeo Emanuele , Argiento Paola , Wacker Julie , D’Aiello Angelo Fabio , Sarubbi Berardo , Russo Maria Giovanna , Naeije Robert , Golino Paolo , Dimopoulos Konstantinos
Published: August 2021

Introduction

Careful, stepwise assessment is required in all patients with atrial septal defect (ASD) to exclude pulmonary vascular or left ventricular (LV) disease. Fluid challenge and balloon occlusion may unmask LV disease and post-capillary pulmonary hypertension, but their role in the evaluation of patients with ‘operable’ ASDs is not well established.

Methods

We conducted a prospective study in three Italian specialist centres between 2018 and 2020. Patients selected for percutaneous ASD closure underwent assessment at baseline and after fluid challenge, balloon occlusion and both.

Results

Fifty patients (46 (38.2, 57.8) years, 72% female) were included. All had a shunt fraction >1.5, pulmonary vascular resistance (PVR) <5 Wood Units (WU) and pulmonary arterial wedge pressure (PAWP) <15 mm Hg. Individuals with a PVR ≥2 WU at baseline (higher PVR group) were older, more symptomatic, with a higher baseline systemic vascular resistance (SVR) than the lower PVR group (all p<0.0001). Individuals with a higher PVR experienced smaller increases in pulmonary blood flow following fluid challenge (0.3 (0.1, 0.5) vs 2.0 (1.5, 2.8) L/min, p<0.0001). Balloon occlusion led to a more marked fall in SVR (p<0.0001) and a larger increase in systemic blood flow (p=0.024) in the higher PVR group. No difference was observed in PAWP following fluid challenge and/or balloon occlusion between groups; four (8%) patients reached a PAWP ≥18 mm Hg following the addition of fluid challenge to balloon occlusion testing.

Conclusions

In adults with ASD without overt LV disease, even small rises in PVR may have significant implications on cardiovascular haemodynamics. Fluid challenge may provide additional information to balloon occlusion in this setting.
Health conditions and the risk of home injury in French adults: results from a prospective study of the MAVIE cohort
Authors: Rojas Castro Madelyn Yiseth , Avalos Marta , Contrand Benjamin , Dupuy Marion , Sztal-Kutas Catherine , Orriols Ludivine , Lagarde Emmanuel
Published: August 2021

Background

Home injury (HI) is a significant cause of mortality and morbidity in adults of all ages. Health conditions significantly impact HI among old adults, but little is known for other adults.

Study design

Prospective cohort study.

Objective

We assessed the associations between health-related factors and HI’s risk in a French study, the MAVIE (Mutualistes pour la recherche contre les Accidents de la VIE courante) cohort.

Methods

Poisson mixed models were fitted using health-related data information (diseases, treatments and disabilities) at baseline and the number of injuries prospectively recorded during the follow-up, adjusting for significant sociodemographics and exposure to a range of home activities. Attributable fractions were estimated based on risk ratio (RR) estimations measured in the fully adjusted models.

Results

A total of 6146 dwelling adults aged 15 or older were followed up for 5.1 years on average. Vertigo or dizziness (RR=2.36, 95% CI 1.06 to 5.01) and sciatica or back pain (RR=1.49, 95% CI 1.08 to 2.05) were independently associated with an increased risk of HI. These two groups of conditions showed the most significant associations among people aged 15–49, whereas musculoskeletal diseases other than rachialgias and arthropathies were the most significant health-related risk factor in people aged 50 and older. Sciatica or back pain represented the highest burden of HIs in overall adults (8%) and among people aged 15–49 (12%).

Conclusion

Our results suggest that adults with musculoskeletal disorders and vertigo or dizziness symptoms have a higher risk of HI, regardless of age.
Evaluating a smartphone application to increase the quantity and improve the quality of supervised practice driving
Authors: Ehsani Johnathon P , Weast Rebecca , Chirles Theresa , Hellinger Andrew , Shields Wendy , Yenokyan Gayane , Igusa Takeru
Published: August 2021

Background

The learner stage of graduated driver licensing (GDL), when teenagers are supervised by an adult driver, represents an opportunity to develop skills that could confer a safety benefit during their years of independent driving. This paper describes the design of a teenage driving study, which aims to evaluate the impact of a smartphone application, the ‘DrivingApp,’ to increase the quantity and improve the quality of supervised practice driving.

Methods

This longitudinal intervention study of teenage drivers and a parent/guardian spans the final 6 months of the learner licence and the first year of independent driving. Participants will be assigned to experimental or control groups using block allocation. Parent–teenage dyads assigned to the intervention arm will receive information about their practice driving via a smartphone application, including miles driven and total drive time. Baseline and monthly surveys will be administered to both experimental and control participants to measure the outcome measures during the learner stage: (1) practice driving amount, (2) consistency and (3) variety. Outcomes during independent driving are (1) self-reported number of attempts at the driving test and (2) number of crashes during the first year of independent driving.

Discussion

Improving the quality of teenagers’ supervised practice driving is an unmet research need. This study will contribute to the evidence about what can be done during the learner period of GDL to maximise teenage drivers’ safety during the first years of independent driving, when crash risk is highest.
Leveraging data science to enhance suicide prevention research: a literature review
Authors: Wulz Avital Rachelle , Law Royal , Wang Jing , Wolkin Amy Funk
Published: August 2021

Objective

The purpose of this research is to identify how data science is applied in suicide prevention literature, describe the current landscape of this literature and highlight areas where data science may be useful for future injury prevention research.

Design

We conducted a literature review of injury prevention and data science in April 2020 and January 2021 in three databases.

Methods

For the included 99 articles, we extracted the following: (1) author(s) and year; (2) title; (3) study approach (4) reason for applying data science method; (5) data science method type; (6) study description; (7) data source and (8) focus on a disproportionately affected population.

Results

Results showed the literature on data science and suicide more than doubled from 2019 to 2020, with articles with individual-level approaches more prevalent than population-level approaches. Most population-level articles applied data science methods to describe (n=10) outcomes, while most individual-level articles identified risk factors (n=27). Machine learning was the most common data science method applied in the studies (n=48). A wide array of data sources was used for suicide research, with most articles (n=45) using social media and web-based behaviour data. Eleven studies demonstrated the value of applying data science to suicide prevention literature for disproportionately affected groups.

Conclusion

Data science techniques proved to be effective tools in describing suicidal thoughts or behaviour, identifying individual risk factors and predicting outcomes. Future research should focus on identifying how data science can be applied in other injury-related topics.
Hypermethylation of CD19 promoter enables antigen-negative escape to CART-19 in vivo and in vitro
Authors: Ledererova Aneta , Dostalova Lenka , Kozlova Veronika , Peschelova Helena , Ladungova Adriana , Culen Martin , Loja Tomas , Verner Jan , Pospisilova Sarka , Smida Michal , Mancikova Veronika
Published: August 2021

Background

Anti-CD19 chimeric antigen receptor T cells (CART-19) frequently induce remissions in hemato-oncological patients with recurred and/or refractory B-cell tumors. However, malignant cells sometimes escape the immunotherapeutic targeting by CD19 gene mutations, alternative splicing or lineage switch, commonly causing lack of CD19 expression on the surface of neoplastic cells. We assumed that, in addition to the known mechanisms, other means could act on CD19 to drive antigen-negative relapse.

Methods

Herein, we studied the mechanism of antigen loss in an in vivo CD19-negative recurrence model of chronic lymphocytic leukemia (CLL) to CART-19, established using NOD-scid IL2Rgnull mice and HG3 cell line. We validated our findings in vitro in immortalized B-cell lines and primary CLL cells.

Results

In our in vivo CLL recurrence model, up to 70% of CART-19-treated mice eventually recurred with CD19-negative disease weeks after initial positive response. We found that the lack of CD19 expression was caused by promoter DNA hypermethylation. Importantly, the expression loss was partially reversible by treatment with a demethylating agent. Moreover, this escape mechanism was common for 3 B-cell immortalized lines as well as primary CLL cells, as assessed by in vitro coculture experiments.

Conclusions

Epigenetically driven antigen escape could represent a novel, yet at least partially reversible, means of CD19 loss to CART-19 in B-cell tumors.
Integrated analysis of a phase 2 study of cemiplimab in advanced cutaneous squamous cell carcinoma: extended follow-up of outcomes and quality of life analysis
Authors: Rischin Danny , Khushalani Nikhil I , Schmults Chrysalyne D , Guminski Alexander , Chang Anne Lynn S , Lewis Karl D , Lim Annette M , Hernandez-Aya Leonel , Hughes Brett G M , Schadendorf Dirk , Hauschild Axel , Thai Alesha A , Stankevich Elizabeth , Booth Jocelyn , Yoo Suk-Young , Li Siyu , Chen Zhen , Okoye Emmanuel , Chen Chieh-I , Mastey Vera , Sasane Medha , Lowy Israel , Fury Matthew G , Migden Michael R
Published: August 2021

Background

To provide pooled longer term data from three groups of a phase 2 study of cemiplimab in patients with advanced cutaneous squamous cell carcinoma (CSCC), and to determine duration of response (DOR) and impact on quality of life (QoL).

Methods

Patients received cemiplimab 3 mg/kg every 2 weeks (group 1, metastatic CSCC [mCSCC], n=59; group 2, locally advanced CSCC, n=78) or cemiplimab 350 mg every 3 weeks (group 3, mCSCC, n=56). Primary endpoint was objective response rate (ORR) per independent central review (ICR). QoL was repeatedly measured at day 1 of each treatment cycle (groups 1 and 2: 8 weeks; group 3: 9 weeks).

Results

Median duration of follow-up was 15.7 months. Overall, ORR per ICR was 46.1% (95% CI: 38.9% to 53.4%). Complete response (CR) rates were 20.3%, 12.8%, and 16.1% for groups 1, 2, and 3, respectively. Median time to CR was 11.2 months. Among patients with partial response or CR, the estimated proportion of patients with ongoing response at 12 months from the first objective response was 87.8% (95% CI: 78.5% to 93.3%), with median DOR not reached. Kaplan-Meier estimated probability of overall survival (OS) was 73.3% (95% CI: 66.1% to 79.2%) at 24 months, with median OS not reached. Global Health Status (GHS)/QoL improvements were observed as early as cycle 2 and were significantly improved and durable until last assessment. Kaplan-Meier estimate of median time to first clinically meaningful improvement for pain was 2.1 (95% CI: 2.0 to 3.7) months and was significantly improved in responders versus non-responders (p<0.0001).

Conclusions

This is the largest (n=193) clinical dataset for a programmed cell death-1 inhibitor against advanced CSCC, confirming the sustained substantial clinical activity of cemiplimab in these patients, including new findings of improved CR rates over time, increasing DOR, and durable pain control and GHS/QoL improvement.

Trial registration number

ClinicalTrials.gov Registry (NCT02760498), https://clinicaltrialsgov/ct2/show/NCT02760498.
Using angiographic parametric imaging-derived radiomics features to predict complications and embolization outcomes of intracranial aneurysms treated by pipeline embolization devices
Authors: Liang Fei , Ma Chao , Zhu Haoyu , Liu Lian , Liang Shikai , Jiang Peng , Zhang Yupeng , Jiang Chuhan
Published: August 2021

Background

Pipeline embolization devices (PEDs) have gained widespread popularity in the treatment of intracranial aneurysms (IAs). However, precise predictors of treatment outcomes are still lacking. This study aimed to use angiographic parametric imaging (API)-derived radiomics features to explore whether biomarkers extracted from immediate postprocedural digital subtraction angiography (DSA) were associated with complications and embolization outcomes of IAs treated with PED without adjunctive coils.

Methods

Radiomic features were extracted from postprocedural DSA by API, and radiomics feature selection and radiomics score calculation were performed by the least absolute shrinkage and selection operator (LASSO) logistic regression. Angiographic findings and clinical characteristics were screened using stepwise multivariable logistic regression analysis to identify significant variables for predicting the complication endpoint. Radiomics feature selection and radiomics risk score (RadRS) calculations were performed by LASSO Cox regression. Univariate and multivariate Cox regression analyses were used to identify significant predictors for the occlusion endpoint.

Results

We screened 281 observations for complications and 235 observations for embolization outcomes from IAs treated in our center using PED between June 2015 and July 2020. Multivariate regression analysis showed association of the radiomics score (p<0.01) and hypertension (p=0.04) with complications. RadRS (p<0.01), symptoms (p<0.01), and age (p=0.03) were predictors of embolization outcomes. Kaplan-Meier analysis revealed that symptomatic patients (p<0.01) and those with off-label IAs (p=0.03) had shorter intervals to complete occlusion.

Conclusions

Biomarkers extracted from immediate postprocedural DSA by API could be potential indicators for assessing treatment outcomes of IAs treated by PED without adjunctive coils.
Effect of region-wide use of prehospital stroke triage scale on management of patients with acute stroke
Authors: Araki Hayato , Uchida Kazutaka , Yoshimura Shinichi , Kurisu Kaoru , Shime Nobuaki , Sakamoto Shigeyuki , Aoki Shiro , Ichinose Nobuhiko , Kajihara Yosuke , Tominaga Atsushi , Naka Hiromitsu , Mizoue Tatsuya , Sumida Masayuki , Hirotsune Nobuyuki , Nomura Eiichi , Matsushige Toshinori , Kanazawa Junichi , Kato Yukio , Kawamoto Yukihiko , Kuroki Kazuhiko , Morimoto Takeshi
Published: August 2021

Background

Prehospital stroke triage scales help with the decision to transport patients with suspected stroke to suitable hospitals.

Objective

To explore the effect of the region-wide use of the Japan Urgent Stroke Triage (JUST) score, which can predict several types of stroke: large vessel occlusion (LVO), intracranial hemorrhage (ICH), subarachnoid hemorrhage (SAH), and cerebral infarction other than LVO (CI).

Methods

We implemented the JUST score and conducted a retrospective and prospective multicenter cohort study at 13 centers in Hiroshima from April 1, 2018, to March 31, 2020. We investigated the success rate of the first request to the hospital, on-scene time, and transport time to hospital. We evaluated the door-to-puncture time, puncture-to-reperfusion time, and 90-day outcome among patients with final diagnoses of LVO.

Results

The cohort included 5141 patients (2735 before and 2406 after JUST score implementation). Before JUST score implementation, 1269 strokes (46.4%) occurred, including 140 LVO (5.1%), 394 ICH (14.4%), 120 SAH (4.4%), and 615 CI (22.5%). The JUST score was used in 1484 (61.7%) of the 2406 patients after implementation, which included 1267 (52.7%) cases of stroke (186 LVO (7.7%), 405 ICH (16.8%), 109 SAH (4.5%), and 567 CI (23.6%)). Success rate of the first request to the hospital significantly increased after JUST score implementation (76.3% vs 79.7%, p=0.004). JUST score implementation significantly shortened the door-to-puncture time (84 vs 73 min, p=0.03), but the prognosis remained unaltered among patients with acute LVO.

Conclusions

Use of prehospital stroke triage scales improved prehospital management and preparation time of intervention among patients with acute stroke.
Sleep duration and sleep efficiency in UK long-distance heavy goods vehicle drivers
Authors: Sherry Aron Peter , Clemes Stacy A , Chen Yu-Ling , Edwardson Charlotte , Gray Laura J , Guest Amber , King James , Rowlands Alex V , Ruettger Katharina , Sayyah Mohsen , Varela-Mato Veronica , Hartescu Iuliana
Published: August 2021

Objectives

To profile sleep duration and sleep efficiency in UK long-distance heavy goods vehicle (HGV) drivers and explore demographic, occupational and lifestyle predictors of sleep.

Methods

Cross-sectional analyses were carried out on 329 HGV drivers (98.5% men) recruited across an international logistics company within the midland’s region, UK. Sleep duration and efficiency were assessed via wrist-worn accelerometry (GENEActiv) over 8 days. Proportions of drivers with short sleep duration (<6 hour/24 hours and <7 hour/24 hours) and inadequate sleep efficiency (<85%) were calculated. Demographic, occupational and lifestyle data were collected via questionnaires and device-based measures. Logistic regression assessed predictors of short sleep duration and inadequate sleep efficiency.

Results

58% of drivers had a mean sleep duration of <6 hour/24 hours, 91% demonstrated <7-hour sleep/24 hours and 72% achieved <85% sleep efficiency. Sleeping <6 hour/24 hours was less likely in morning (OR 0.45, 95% CI 0.21 to 0.94) and afternoon (OR 0.24, CI 0.10 to 0.60) shift workers (vs night) and if never smoked (vs current smokers) (OR 0.45, CI –0.22 to 0.92). The likelihood of sleeping <7 hour/24 hours reduced with age (OR 0.92, CI 0.87 to 0.98). The likelihood of presenting inadequate sleep efficiency reduced with age (OR 0.96, CI 0.93 to 0.99) and overweight body mass index category (vs obese) (OR 0.47, CI 0.27 to 0.82).

Conclusions

The high prevalence of short sleep duration and insufficient sleep quality (efficiency) rate suggest that many HGV drivers have increased risk of excessive daytime sleepiness, road traffic accidents and chronic disease. Future sleep research in UK HGV cohorts is warranted given the road safety and public health implications.
Coverage-dependent magnetic and electronic properties of graphene with Co adatoms
Authors: Gao Min , Hu Jun
Published: August 2021

Decorating two-dimensional (2D) materials with transition-metal adatoms is an effective way to bring about new physical properties that are intriguing for applications in electronics and spintronics devices. Here, we systematically studied the coverage-dependent magnetic and electronic properties of graphene decorated by Co adatoms, based on first-principles calculations. We found that if the Co coverage is larger than 1/3[Formula: see text]ML, the Co atoms will aggregate to form a Co monolayer and then a van der Waals bilayer system between the Co monolayer and graphene forms. When the Co coverage is [Formula: see text][Formula: see text]ML, the Co adatom is spin-polarized with spin moment varying from 1.1 to 1.4[Formula: see text][Formula: see text]. The [Formula: see text] and [Formula: see text] orbitals of Co hybridize significantly with the [Formula: see text] bands of graphene, which generates a series of new bands in the energy range from [Formula: see text][Formula: see text]eV to 1[Formula: see text]eV with respect to the Dirac point of graphene. In most cases, the new bands near the Fermi level lead to topological states characterized by the quantum anomalous Hall effect.
Crowd attraction-driven community evolution on social network
Authors: Nian Fuzhong , Luo Li , Yu Xuelong
Published: August 2021

The evolution analysis of community structure of social network will help us understand the composition of social organizations and the evolution of society better. In order to discover the community structure and the regularity of community evolution in large-scale social networks, this paper analyzes the formation process and influencing factors of communities, and proposes a community evolution analysis method of crowd attraction driven. This method uses the traditional community division method to divide the basic community, and introduces the theory of information propagation into complex network to simulate the information propagation of dynamic social networks. Then defines seed node, the activity of basic community and crowd attraction to research the influence of groups on individuals in social networks. Finally, making basic communities as fixed groups in the network and proposing community detection algorithm based on crowd attraction. Experimental results show that the scheme can effectively detect and identify the community structure in large-scale social networks.
Varying of up-conversion nanoparticles luminescence from the muscle tissue depth during the compression
Authors: Kozintseva Marina , Kochubey Vyacheslav , Konyukhova Julia , Tuchin Valery
Published: August 2021

The current work is focused on the study of optical clearing of skeletal muscles under local compression. The experiments were performed on in vitro bovine skeletal muscle. The time dependence of optical clearing was studied by monitoring the luminescence intensity of NaYF4:Er,Yb upconverting particles located under tissue layers. This study shows the possibility to use upconverting nanoparticles (UCNPs) both for studying the dynamics of the optical clearing of biological tissue under compression and to detect moments of cell wall damage under excessive pressure. The advantage of using UCNPs is the presence of several bands in their luminescence spectra, located both at close wavelengths and far apart.
Dielectric and piezoelectric properties of modified lead-free NaNbO3–KNbO3/PVDF composite ceramics
Authors: Yurasov Y. I. , Tolstunov M. I. , Nazarenko A. V. , Pavelko A. A. , Yudin A. V. , Verbenko I. A. , Reznitchenko L. A.
Published: August 2021

This work presents the results of study of the electrophysical properties of composite polymer ceramics (1[Formula: see text][KNN-LTSN]–[Formula: see text]PVDF at [Formula: see text] = 25 vol.% and [Formula: see text]= 50 vol.% in the temperature range of [Formula: see text] = 20–160[Formula: see text]C and frequency range of [Formula: see text] = 2 × 101–2 × 106 Hz. The concentration dependence of piezomodules of the studied materials has been analyzed as a function of temperature. X-ray measurements have also been carried out. A model of description of revealed dielectric parameters dispersion in the material is presented. The nonclassical modified Havriliak–Negami model written for complex electrical conductivity has been used to describe the temperature–frequency properties. It is shown that the dielectric spectra of the studied composites include three relaxation processes in the temperature ranges of 40–80[Formula: see text]C, 80–120[Formula: see text]C and 120–150 [Formula: see text]C, which were confirmed by the dynamics of changes in the dependences of [Formula: see text], tg[Formula: see text], [Formula: see text], [Formula: see text]([Formula: see text]) and [Formula: see text]([Formula: see text]. All three processes are almost exactly described by this model and well correlated with the studies by other researchers of the composites based on PVDF. The results of this work show that the use of such experimental model is suitable for describing the complex dielectric spectra of any nonlinear dielectrics including composite materials.
Optimal Packet Camouflage Against Traffic Analysis
Authors: Chaddad Louma , Chehab Ali , Elhajj Imad H. , Kayssi Ayman
Published: August 2021

Research has proved that supposedly secure encrypted network traffic is actually threatened by privacy and security violations from many aspects. This is mainly due to flow features leaking evidence about user activity and data content. Currently, adversaries can use statistical traffic analysis to create classifiers for network applications and infer users’ sensitive data. In this article, we propose a system that optimally prevents traffic feature leaks. In our first algorithm, we model the packet length probability distribution of the source app to be protected and that of the target app that the source app will resemble. We define a model that mutates the packet lengths of a source app to those lengths from the target app having similar bin probability. This would confuse a classifier by identifying a mutated source app as the target app. In our second obfuscation algorithm, we present an optimized scheme resulting in a trade-off between privacy and complexity overhead. For this reason, we propose a mathematical model for network obfuscation. We formulate analytically the problem of selecting the target app and the length from the target app to mutate to. Then, we propose an algorithm to solve it dynamically. Extensive evaluation of the proposed models, on real app traffic traces, shows significant obfuscation efficiency with relatively acceptable overhead. We were able to reduce a classification accuracy from 91.1% to 0.22% using the first algorithm, with 11.86% padding overhead. The same classification accuracy was reduced to 1.76% with only 0.73% overhead using the second algorithm.
Towards Better Understanding of User Authorization Query Problem via Multi-variable Complexity Analysis
Authors: Crampton Jason , Gutin Gregory Z. , Majumdar Diptapriyo
Published: August 2021

User authorization queries in the context of role-based access control have attracted considerable interest in the past 15 years. Such queries are used to determine whether it is possible to allocate a set of roles to a user that enables the user to complete a task, in the sense that all the permissions required to complete the task are assigned to the roles in that set. Answering such a query, in general, must take into account a number of factors, including, but not limited to, the roles to which the user is assigned and constraints on the sets of roles that can be activated. Answering such a query is known to be NP-hard. The presence of multiple parameters and the need to find efficient and exact solutions to the problem suggest that a multi-variate approach will enable us to better understand the complexity of the user authorization query problem (UAQ).

In this article, we establish a number of complexity results for UAQ. Specifically, we show the problem remains hard even when quite restrictive conditions are imposed on the structure of the problem. Our fixed-parameter tractable (FPT) results show that we have to use either a parameter with potentially quite large values or quite a restricted version of UAQ. Moreover, our second FPT algorithm is complex and requires sophisticated, state-of-the-art techniques. In short, our results show that it is unlikely that all variants of UAQ that arise in practice can be solved reasonably quickly in general.
An order-aware dataflow model for parallel Unix pipelines
Authors: Handa Shivam , Kallas Konstantinos , Vasilakis Nikos , Rinard Martin C.
Published: August 2021

We present a dataflow model for modelling parallel Unix shell pipelines. To accurately capture the semantics of complex Unix pipelines, the dataflow model is order-aware, i.e., the order in which a node in the dataflow graph consumes inputs from different edges plays a central role in the semantics of the computation and therefore in the resulting parallelization. We use this model to capture the semantics of transformations that exploit data parallelism available in Unix shell computations and prove their correctness. We additionally formalize the translations from the Unix shell to the dataflow model and from the dataflow model back to a parallel shell script. We implement our model and transformations as the compiler and optimization passes of a system parallelizing shell pipelines, and use it to evaluate the speedup achieved on 47 pipelines.
Formal verification of a concurrent bounded queue in a weak memory model
Authors: Mével Glen , Jourdan Jacques-Henri
Published: August 2021

We use Cosmo, a modern concurrent separation logic, to formally specify and verify an implementation of a multiple-producer multiple-consumer concurrent queue in the setting of the Multicore OCaml weak memory model. We view this result as a demonstration and experimental verification of the manner in which Cosmo allows modular and formal reasoning about advanced concurrent data structures. In particular, we show how the joint use of logically atomic triples and of Cosmo's views makes it possible to describe precisely in the specification the interaction between the queue library and the weak memory model.
Of JavaScript AOT compilation performance
Authors: Serrano Manuel
Published: August 2021

The fastest JavaScript production implementations use just-in-time (JIT) compilation and the vast majority of academic publications about implementations of dynamic languages published during the last two decades focus on JIT compilation. This does not imply that static compilers (AoT) cannot be competitive; as comparatively little effort has been spent creating fast AoT JavaScript compilers, a scientific comparison is lacking. This paper presents the design and implementation of an AoT JavaScript compiler, focusing on a performance analysis. The paper reports on two experiments, one based on standard JavaScript benchmark suites and one based on new benchmarks chosen for their diversity of styles, authors, sizes, provenance, and coverage of the language. The first experiment shows an advantage to JIT compilers, which is expected after the decades of effort that these compilers have paid to these very tests. The second shows more balanced results, as the AoT compiler generates programs that reach competitive speeds and that consume significantly less memory. The paper presents and evaluates techniques that we have either invented or adapted from other systems, to improve AoT JavaScript compilation.
Algebras for weighted search
Authors: Kidney Donnacha Oisín , Wu Nicolas
Published: August 2021

Weighted search is an essential component of many fundamental and useful algorithms. Despite this, it is relatively under explored as a computational effect, receiving not nearly as much attention as either depth- or breadth-first search. This paper explores the algebraic underpinning of weighted search, and demonstrates how to implement it as a monad transformer.

The development first explores breadth-first search, which can be expressed as a polynomial over semirings. These polynomials are generalised to the free semimodule monad to capture a wide range of applications, including probability monads, polynomial monads, and monads for weighted search. Finally, a monad transformer based on the free semimodule monad is introduced. Applying optimisations to this type yields an implementation of pairing heaps, which is then used to implement Dijkstra's algorithm and efficient probabilistic sampling. The construction is formalised in Cubical Agda and implemented in Haskell.
Reasoning about effect interaction by fusion
Authors: Yang Zhixuan , Wu Nicolas
Published: August 2021

Effect handlers can be composed by applying them sequentially, each handling some operations and leaving other operations uninterpreted in the syntax tree. However, the semantics of composed handlers can be subtle---it is well known that different orders of composing handlers can lead to drastically different semantics. Determining the correct order of composition is a non-trivial task.

To alleviate this problem, this paper presents a systematic way of deriving sufficient conditions on handlers for their composite to correctly handle combinations, such as the sum and the tensor, of the effect theories separately handled. These conditions are solely characterised by the clauses for relevant operations of the handlers, and are derived by fusing two handlers into one using a form of fold/build fusion and continuation-passing style transformation.

As case studies, the technique is applied to commutative and distributive interaction of handlers to obtain a series of results about the interaction of common handlers: (a) equations respected by each handler are preserved after handler composition; (b) handling mutable state before any handler gives rise to a semantics in which state operations are commutative with any operations from the latter handler; (c) handling the writer effect and mutable state in either order gives rise to a correct handler of the commutative combination of these two theories.
Contextual modal types for algebraic effects and handlers
Authors: Zyuzin Nikita , Nanevski Aleksandar
Published: August 2021

Programming languages with algebraic effects often track the computations’ effects using type-and-effect systems. In this paper, we propose to view an algebraic effect theory of a computation as a variable context; consequently, we propose to track algebraic effects of a computation with
contextual modal types
. We develop ECMTT, a novel calculus which tracks algebraic effects by a contextualized variant of the modal □ (necessity) operator, that it inherits from Contextual Modal Type Theory (CMTT).

Whereas type-and-effect systems add effect annotations on top of a prior programming language, the effect annotations in ECMTT are inherent to the language, as they are managed by programming constructs corresponding to the logical introduction and elimination forms for the □ modality. Thus, the type-and-effect system of ECMTT is actually just a type system.

Our design obtains the properties of local soundness and completeness, and determines the operational semantics solely by β-reduction, as customary in other logic-based calculi. In this view, effect handlers arise naturally as a witness that one context (i.e., algebraic theory) can be reached from another, generalizing explicit substitutions from CMTT.

To the best of our knowledge, ECMTT is the first system to relate algebraic effects to modal types. We also see it as a step towards providing a correspondence in the style of Curry and Howard that may transfer a number of results from the fields of modal logic and modal type theory to that of algebraic effects.
Symbolic and automatic differentiation of languages
Authors: Elliott Conal
Published: August 2021

Formal languages are usually defined in terms of set theory. Choosing type theory instead gives us languages as type-level predicates over strings. Applying a language to a string yields a type whose elements are language membership proofs describing
how
a string parses in the language. The usual building blocks of languages (including union, concatenation, and Kleene closure) have precise and compelling specifications uncomplicated by operational strategies and are easily generalized to a few general domain-transforming and codomain-transforming operations on predicates.

A simple characterization of languages (and indeed functions from lists to any type) captures the essential idea behind language “differentiation” as used for recognizing languages, leading to a collection of lemmas about type-level predicates. These lemmas are the heart of two dual parsing implementations—using (inductive) regular expressions and (coinductive) tries—each containing the same code but in dual arrangements (with representation and primitive operations trading places). The regular expression version corresponds to symbolic differentiation, while the trie version corresponds to automatic differentiation.

The relatively easy-to-prove properties of type-level languages transfer almost effortlessly to the decidable implementations. In particular, despite the inductive and coinductive nature of regular expressions and tries respectively, we need neither inductive nor coinductive/bisimulation arguments to prove algebraic properties.