bluuebunny/crossref_metadata_2025 huggingface dataset:
Is nutrition in the trauma patient optimally managed?
Authors: Segaran E , Khan M A
Published: November 2020

The fields of civilian and military trauma management have evolved over the years into a multidisciplinary approach, extending beyond immediate lifesaving resuscitation to definitive treatment and rehabilitation. Despite advances in the field of trauma, some aspects of the injured patient’s care, including the provision of adequate nutritional support, continue to represent a significant challenge. This article endeavours to provide an overview of the problems faced in managing nutrition in a trauma patient, and the relevance to the military operational context.
The United States Military Mountain Medicine Course and its relevance to the United Kingdom armed forces
Authors: Mackey J
Published: November 2020

Working in mountainous terrain, often at high altitude, presents a unique set of challenges to military medical personnel both in deployed roles and on adventurous training expeditions. Courses such as the increasingly popular Diploma in Mountain Medicine can provide clinicians with the knowledge and skills required to work in this environment. This article describes the current provision of mountain medicine education in the United Kingdom (UK). It also details the United States Military Mountain Medicine course as an example of military specific mountain medicine training and its relevance to UK armed forces medical personnel.
Ajax Bay
Authors: Jolly R T
Published: November 2020

As a result of fierce aerial attacks on the fleet supporting the landing force on Friday, 21 May 1982, SS CANBERRA was ordered to sail from San Carlos Water. Elements of her medical organisation were hurriedly put ashore into a deserted refrigeration plant at Ajax Bay. Three weeks later they had treated over 650 battle casualties, performed 210 operations under general anaesthetic, and been bombed by Argentinian aircraft. Despite appalling circumstances, their results were a triumphant success. As Officer Commanding Medical Squadron, Commando Logistics Regiment RM, the author was in charge at Ajax Bay throughout the land phase of hostilities.
Upper limb reconstructive transplantation in military recipients
Authors: Fries C A , Stark H L , Tuder D , Iyer S , Gorantla V S , Davis M R , Rickard R F
Published: November 2020

Lessons from conflict have contributed to military medical advances which have significantly improved the survivability of critically injured servicemen and women. However, survival following such severe combat polytrauma is often associated with devastating tissue loss and functional deficits that challenge conventional reconstruction. Despite recent advances, upper extremity prosthetic alternatives lack the fidelity to restore the complex intrinsic and sensory function of the human hand. Upper Limb Reconstructive Transplantation, or Vascularised Composite Allotransplantation (VCA), is currently an experimental procedure offering superior anatomical and functional outcomes compared to prostheses.

Military candidates for VCA usually enjoy high pre-morbid fitness, mental health resilience and support, and relatively rich provision of rehabilitation. However, co-morbidities of polytrauma, such as traumatic brain injury and post-traumatic stress disorder, may have an impact on outcomes.

Since 1998, over 120 upper limb transplants have been performed worldwide. Of these, six have been performed on servicemen and women across three continents. The morbidity and mortality associated with the requirement for lifelong immunosuppression, however, continues to skew the risk-benefit considerations of these promising procedures when compared to prostheses. Thus, although the technical surgical feasibility of upper limb and other VCA such as face, abdominal wall, uterus and penis transplants has been established over the past decade, these procedures remain restricted to recipients fulfilling stringent inclusion criteria.

We review the current state of VCA in military recipients, and summarise ongoing collaborative VCA research conducted by British and American military medical teams.
Hypokalaemic ECG changes secondary to intramuscular adrenaline after a snake bite in Sierra Leone
Authors: Williams A
Published: November 2020

This case report describes a young UK military medic who suffered a snakebite while working in Sierra Leone. He was given intramuscular adrenaline (epinephrine) and was subsequently found to have hypokalaemia, hypoglycaemia and a wide pulse pressure. His ECG showed changes typical of moderate hypokalaemia.
In-situ simulation: a review of Role 2 Afloat team training in HMS QUEEN ELIZABETH during WESTLANT 18
Authors: Bott G , Matthews J J
Published: November 2020

The maiden deployment of HMS QUEEN ELIZABETH (WESTLANT 18) was supported by a Role 2 Afloat (R2A) team. This deployment enabled the first of class fixed wing flying trials for the F35-B Lightning and gave the deployed team the opportunity to establish the R2A capability within the Carrier Strike Group. During the deployment the team engaged in continuous medical education and training. This paper describes the experience of the team utilising in-situ simulation techniques, which had not been used before on a R2A deployment. In particular, a high fidelity in-situ simulation exercise (Ex POSEIDON) was enabled with the support of the US Navy, and the lessons identified from this are described.
Ebola Virus Disease - clinical manifestations, management and future therapies
Authors: O’Brien D , O’Shea M K , Fletcher T E
Published: November 2020

The largest epidemic of Ebola Virus Disease in recorded human history occurred in West Africa in 2014 and resulted in significant morbidity and mortality. The causative pathogen, Ebola virus, is readily transmitted through contact with the body fluids of infected individuals and from the bodies of those who have died from the disease. In its early stages, the illness is characterised by non-specific symptoms that mimic many other endemic infectious diseases in countries with limited healthcare resources. These factors contributed to the rapid spread of the outbreak, which required an international response in which the UK Armed Forces played an important role. This review describes the clinical presentation, lessons learned from managing the West African outbreak, and potential future treatments.
Efficacy of pre-hospital fracture manipulation following ketamine administration: the experience of a single civilian air ambulance trust
Authors: Follows A , James R H , Vassallo J
Published: November 2020

Aims

Limb fractures are common in pre-hospital care and can be associated with significant haemorrhage and neurovascular compromise. The pre-hospital management of these injuries centres around reduction and splinting. The aim of this study was to quantify the effectiveness of pre-hospital reduction of displaced fractures or dislocations and the incidence of the need for further manipulation in the emergency department.

Methods

A three-year retrospective database analysis was conducted for all patients sustaining limb injuries who were attended by a single air ambulance and subsequently conveyed to the regional major trauma centre. Only patients who received ketamine, either as an analgesic or sedative, were included. Pre-hospital clinical records and emergency department (ED) notes were examined to determine outcomes.

Results

Over the study period, 122 patients sustained a limb injury and received ketamine; ED notes were available for 96 (78.7%). Of these, the majority (n=51, 41.8%) received ketamine for analgesia with n=10 (8.2%) receiving it to facilitate manipulation. The principal indication for pre-hospital manipulation was neurovascular compromise (n=7, 70.0%). Of those undergoing manipulation pre-hospital, the majority (n=7, 70.0%) required further manipulation in the ED.

Conclusion

Pre-hospital manipulation by our regional air ambulance is a relatively low frequency event and in those undergoing a manipulation, a high proportion require further intervention in the ED or operative intervention within the acute phase of care.
Medical leadership and management for military clinicians
Authors: Cottey L , Lillington C , Frost E
Published: November 2020

The development of medical leadership and management skills is an essential requirement for the progression of Defence Medical Services personnel in both military and medical training. This review will summarise how military experience can contribute to achieving medical leadership and management competencies and will signpost further opportunities and resources available. While it specifically focuses on doctors, this article has relevance to all Defence Healthcare Professionals.
How do you solve a problem like… missing data? Lessons from the PAin SoluTions In the Emergency Setting (PASTIES) trials
Authors: Smith J E , Creanor S , Rockett M , Ewings P
Published: November 2020

When studies measure the effect of a treatment longitudinally over time, multiple data points are generated, but are sometimes incomplete. This may affect studies in a range of different settings, including studies on military patients. When analysing the data from such a study, one of the challenges is how to deal with missing data points in the final analysis. This article describes the possible different ways of dealing with missing data points in such a context, and outlines some pragmatic methods used for handling missing pain scores in the recent PAin SoluTions In the Emergency Setting (PASTIES) trials.
The use of Unmanned Aerial Vehicles for CASEVAC in the future urban and littoral environments
Authors: McKnight G , Palmer M , Khan M
Published: November 2020

The recent development of Unmanned Aerial Vehicles (UAVs) and their potential use for casualty evacuation (CASEVAC) has exciting implications for the United Kingdom Defence Medical Services (DMS). When compared to existing technology, the unique attributes of small size, increased manoeuvrability and lack of a human pilot would be extremely useful in congested and hazardous settings. There are ethical and practical considerations to be taken into account, but harnessing the full potential of this technology may improve the chances of survival from some battlefield injuries.

UAVs could be of most benefit in a congested and complex battlespace, allowing evacuation of casualties from high risk environments. In addition to CASEVAC, a UAV could be used for critical care transfers, Search and Rescue (SAR) and Humanitarian And Disaster Relief (HADR) operations. Given the vast array of potential applications and a lower risk profile compared with current CASEVAC platforms, the DMS should actively monitor the development of UAV technology and plan ahead for integration within current doctrine.
Effect of bodyweight on VerifyNow Aspirin platelet function test: a retrospective review
Authors: Sandler Melissa , Hoang Cuong , Mak Hannah Y , Levitt Michael R
Published: November 2020

Background

Antiplatelet therapy is used to prevent stent thrombosis in intracranial stents, but the optimal dose of aspirin is unknown. This study sought to determine whether the degree of platelet inhibition with aspirin is affected by bodyweight as observed through a platelet reactivity assay.

Methods

This is a retrospective review of patients who underwent neurovascular stent placement and had a VerifyNow Aspirin assay result. The primary outcome was the correlation between the VerifyNow Aspirin result, bodyweight, and the initial dose of aspirin. Secondary outcomes included the impact of the VerifyNow P2Y12 result and of weight on the incidence of bleeding or a thrombotic event.

Results

Of the 142 included patients, 62.7% weighed ≥70 kg and 88.7% were initiated on aspirin 300–325 mg daily. 83.8% achieved a therapeutic VerifyNow Aspirin result. There was minimal correlation between the VerifyNow Aspirin result, bodyweight, and aspirin dose (R2=0.02). Between patients who weighed <70 kg versus ≥70 kg, there was no difference in the mean aspirin reaction units (ARU) (449 vs 435, p=0.32) or in the incidence of bleeding (28% vs 17.1%, p=0.14) or a thrombotic event (4% vs 5.3%, p=0.59). No patient experienced stent thrombosis and eight patients experienced in-stent stenosis. In a multivariate analysis, only the VerifyNow P2Y12 result predicted the development of either bleeding or a thrombotic event (p<0.01).

Conclusions

Bodyweight did not influence the likelihood of obtaining a therapeutic VerifyNow Aspirin result. The clinical utility of obtaining VerifyNow Aspirin assays for this patient population is unknown.
Effect of exercise on sleep and bi-directional associations with accelerometer-assessed physical activity in men with obesity
Authors: Plekhanova Tatiana , Rowlands Alex V. , Davies Melanie , Edwardson Charlotte L. , Hall Andrew , Yates Thomas
Published: November 2020

This study examined the effect of exercise training on sleep duration and quality and bidirectional day-to-day relationships between physical activity (PA) and sleep. Fourteen inactive men with obesity (age: 49.2 ± 7.9 years, body mass index: 34.9 ± 2.8 kg/m2) completed a baseline visit, 8-week aerobic exercise intervention, and 1-month post-intervention follow-up. PA and sleep were assessed continuously throughout the study duration using wrist-worn accelerometry. Generalised estimating equations were used to examine associations between PA and sleep. Sleep duration increased from 5.2 h at baseline to 6.6 h during the intervention period and 6.5 h at 1-month post-intervention follow-up (p < 0.001). Bi-directional associations showed that higher overall activity volume and moderate-to-vigorous physical activity (MVPA) were associated with earlier sleep onset time (p < 0.05). Later timing of sleep onset was associated with lower overall volume of activity, most active continuous 30 min (M30CONT), and MVPA (p < 0.05). Higher overall activity volume, M30CONT, and MVPA predicted more wake after sleep onset (WASO) (p < 0.001), whereas greater WASO was associated with higher overall volume of activity, M30CONT, and MVPA (p < 0.001). An aerobic exercise intervention increased usual sleep duration. Day-to-day, more PA predicted earlier sleep onset, but worse sleep quality and vice versa.

Novelty: Greater levels of physical activity in the day were associated with an earlier sleep onset time that night, whereas a later timing of sleep onset was associated with lower physical activity the next day in men with obesity. Higher physical activity levels were associated with worse sleep quality, and vice versa.
A Position Weighted Information Based Word Embedding Model for Machine Translation
Authors: Li Zhen , Qu Dan , Li Yanxia , Xie Chaojie , Chen Qi
Published: November 2020

Deep learning technology promotes the development of neural network machine translation (NMT). End-to-End (E2E) has become the mainstream in NMT. It uses word vectors as the initial value of the input layer. The effect of word vector model directly affects the accuracy of E2E-NMT. Researchers have proposed many approaches to learn word representations and have achieved significant results. However, the drawbacks of these methods still limit the performance of E2E-NMT systems. This paper focuses on the word embedding technology and proposes the PW-CBOW word vector model which can present better semantic information. We apply these word vector models on IWSLT14 German-English, WMT14 English-German, WMT14 English-French corporas. The results evaluate the performance of the PW-CBOW model. In the latest E2E-NMT systems, the PW-CBOW word vector model can improve the performance.
A BERT Fine-tuning Model for Targeted Sentiment Analysis of Chinese Online Course Reviews
Authors: Zhang Huibing , Dong Junchao , Min Liang , Bi Peng
Published: November 2020

Accurate analysis of targeted sentiment in online course reviews helps in understanding emotional changes of learners and improving the course quality. In this paper, we propose a fine-tuned bidirectional encoder representation from transformers (BERT) model for targeted sentiment analysis of course reviews. Specifically, it consists of two parts: binding corporate rules — conditional random field (BCR-CRF) target extraction model and a binding corporate rules — double attention (BCR-DA) target sentiment analysis model. Firstly, based on a large-scale Chinese review corpus, intra-domain unsupervised training of a BERT pre-trained model (BCR) is performed. Then, a Conditional Random Field (CRF) layer is introduced to add grammatical constraints to the output sequence of the semantic representation layer in the BCR model. Finally, a BCR-DA model containing double attention layers is constructed to express the sentiment polarity of the course review targets in a classified manner. Experiments are performed on Chinese online course review datasets of China MOOC. The experimental results show that the F1 score of the BCR-CRF model reaches above 92%, and the accuracy of the BCR-DA model reaches above 72%.
Research on Automatic Vulnerability Mining Model Based on Knowledge Graph
Authors: Chen Ze , Zuo Xiaojun , Hou Botao , Dong Na , Chang Jie
Published: November 2020

In the information extraction, information sources can be screened according to the characteristics of the target network at the present stage, and the knowledge graph generated thereby can play a role in assisting the security analysis of the general network or power grid control network, mobile Internet and other special networks. In the method proposed in this paper, knowledge reasoning is mainly based on the attack conditions and attack methods to reason about the success rate and return of the attack. Through the obtained quality information, map construction information extraction and reasoning are performed to realize the correlation analysis of the information, and the information processing results are stored in the graphic structure. When analyzing the alerts generated by IDS, it is necessary to solve the multi-source alarm format generated by various devices produced by different suppliers. The attack diagram constructs the attack mode to guide the defense side to take targeted defense measures, and the attack success rate is used to judge the defense priority of all network nodes. After completing the construction of the graph, the attack graph is generated for the specific network environment under the guidance of the knowledge graph. In the process of attack graph generation, attack method and attack condition of attack instance can be used to guide the match of pre-condition and post-condition, so as to find the attack path. Attack success rate and attack profit attribute can be used to assist subsequent risk analysis. After simulation tests, the timeliness and availability of the system are verified, and this makes a contribution to the grid network management.
Circular motion and the innermost stable circular orbit for spinning particles around a charged Hayward black hole background
Authors: Larrañaga Eduard
Published: November 2020

The circular orbits of a spinning test particle moving around a charged Hayward black hole is investigated by using the Mathisson–Papapetrou–Dixon equations together with the Tulczyjew spin-supplementary condition. By writing the equations of motion, the effective potential for the description of the test particle is obtained to study the properties of the Innermost Stable Circular Orbit (ISCO). The results show that the ISCO radii for spinning particles moving in the charged Hayward background differ from those obtained in the corresponding Schwarzschild or Reissner–Nordstrom spacetimes, depending on the values of the electric charge and the length-scale parameter of the metric. When the spin of the particle and its orbital angular momentum are aligned, an increase in the spin produces a decrease in the ISCO radius, while in the case in which the spin of the particle and its orbital angular momentum are anti-aligned, an increase in the spin results in an increase of the radius of the ISCO.
Numerical Investigation on Mixed Mode (I-II) Fracture Propagation of CCBD Specimens Under Confining Pressure
Authors: Huang Jiuzhou , Li Jianxiong , Pan Xin , Xie Tianzhou , Hua Wen , Dong Shiming
Published: November 2020

A new numerical method, verified by the analytical solution of the weight functions and experimental paths, is developed to evaluate the crack initiation and propagation generally in mixed mode (I-II). This numerical method combining the interaction integral method and the maximum tangential stress (MTS) criterion is based on the finite element method of secondary development. The influence of combined confining pressure and diametric forces on crack propagation trajectories for CCBD specimens are studied. It is indicated that the crack propagation direction independent of the confining pressure keeps the same with the line of original crack as the loading angle is equal to [Formula: see text]. But when the loading angle is greater than [Formula: see text], the curvature of the curve trajectory in the early stage of crack propagation increases with a larger confining pressure. Further, it is found that larger values of the loading angle and relative length will make the effect of confining pressure more significant at the early stage of crack growth.
Optimization of Viscoelastic Metamaterials for Vibration Attenuation Properties
Authors: Ghachi Ratiba F. , Alnahhal Wael I. , Abdeljaber Osama , Renno Jamil , Tahidul Haque A. B. M. , Shim Jongmin , Aref Amjad
Published: November 2020

Metamaterials (MMs) are composites that are artificially engineered to have unconventional mechanical properties that stem from their microstructural geometry rather than from their chemical composition. Several studies have shown the effectiveness of viscoelastic MMs in vibration attenuation due to their inherent vibration dissipation properties and the Bragg scattering effect. This study presents a multiobjective optimization based on genetic algorithms (GA) that aims to find a viscoelastic MM crystal with the highest vibration attenuation in a chosen low-frequency range. A multiobjective optimization allows considering the attenuation due to the MM inertia versus the Bragg scattering effect resulting from the periodicity of the MM. The investigated parameters that influence wave transmission in a one-dimensional (1D) MM crystal included the lattice constant, the number of cells and the layers’ thickness. Experimental testing and finite element analysis were used to support the optimization procedure. An electrodynamic shaker was used to measure the vibration transmission of the three control specimens and the optimal specimen in the frequency range 1–1200[Formula: see text]Hz. The test results demonstrated that the optimized specimen provides better vibration attenuation than the control specimens by both having a band-gap starting at a lower frequency and having less transmission at its passband.
A Simple Truly Self-Starting and L-Stable Integration Algorithm for Structural Dynamics
Authors: Li Jinze , Yu Kaiping
Published: November 2020

This paper proposes a novel composite two sub-step implicit method to effectively solve structural dynamic problems. The main highlight of the new method lies that it is truly self-starting and so avoids computing the initial acceleration vector, but the second-order accurate acceleration output can be still provided. Besides, the new method does not sacrifice other desired numerical characteristics, such as the identical second-order accuracy, unconditional stability (L-stability) and no overshoots. As with the existing Bathe algorithm, the new method also includes a unique algorithmic parameter [Formula: see text] to adjust numerical dissipation imposed in the low-frequency range. Numerical spectral analysis and examples show that the new method with [Formula: see text] is highly recommended solving various dynamical problems.
Numerical Analysis of Shallow Foundations Resting on Granular Columns Embedded in Liquefiable Soil
Authors: Dinesh Natarajan , Banerjee Subhadeep , Rajagopal Karpurapu
Published: November 2020

Shallow footings are the most preferred foundations for buildings due to low cost and ease of construction. However, under seismic loads, these foundations may suffer excessive settlements, particularly when there is a risk of soil liquefaction. This paper explores the effectiveness of granular columns in mitigating the liquefaction-induced ground deformations under shallow foundations, using FLAC2D program. PM4Sand, a critical state-based bounding surface plasticity model is used to simulate the stress–strain response of sand to cyclic loading. The responses of granular columns are also simulated using the same soil model. Validation of the numerical model is presented against the experimental results of mildly sloping ground. The application of granular column groups resulted in maximum reduction of the settlement of footing by 60% when soil densification is included along with drainage and stress redistribution effects. Though excess pore water pressure is relatively low in treated deposit compared to the untreated deposit, its contribution to the reduction in settlement of footing is found to be minimal.
The uncoupled microbial fed-batch fermentation optimization based on state-dependent switched system
Authors: Niu Teng , Zhai Jingang , Yin Hongchao , Feng Enmin , Liu Chongyang
Published: November 2020

In the actual microbial fermentation process, excessive or insufficient substrate can produce inhibitory effects on cells growth. The artificial substrate feeding rules by past experiences have great blindness to keep substrate concentration in a given appropriate range. This paper considers that alkali feed depends on pH value of the solution and glycerol feed depends on glycerol concentration of the solution in the uncoupled microbial fed-batch fermentation process, and establishes a state-dependent switched system in which the flow rates of glycerol and alkali, the number of mode switches, the mode sequence and the switching times are prior unknown. To maximize the yield of target product 1,3-Propanediol (1,3-PD), we formulate a switching optimal control problem with the flow rates of glycerol and alkali, the number of mode switches, the mode sequence and the switching times as decision variables, which is a mixed-integer dynamic programming problem. For solving the mixed-integer dynamic programming problem, the control parametrization technique, the time scaling transformation and the embedded system technology are used to obtain an approximate parameter optimization problem. By using a parallel optimization algorithm, we obtain the optimal control strategies. Under the obtained optimal control strategies, the 1,3-PD yield at the terminal time is increased significantly compared with the previous results.
Improved cycling stability of Ni-rich LiNi0.8Co0.1Mn0.1O2 cathode materials by optimizing Ti doping
Authors: Wang Nengneng , Zhu Yutao , Yao Jinlei , Zhao Meng , Xu Yanhui
Published: November 2020

Nickel-rich LiNi[Formula: see text]Co[Formula: see text]Mn[Formula: see text]O2 (NCM811) oxide is a prospective cathode material of Li-ion batteries owing to its high energy density and affordable price, however, it suffers from the poor cycling performance. The doping for metal cations is considered as an effective way to enhance its cycling stability. In this work, titanium was chosen to partially substitute transition-metal ions, i.e. Ni, Co and Mn, and the Ti content was optimized to improve the electrochemical performance of NCM811. The Ti-doped Li(Ni[Formula: see text]Co[Formula: see text]Mn[Formula: see text]Ti[Formula: see text]O2 powder was prepared using high temperature solid-state synthesis. The layered [Formula: see text]-NaFeO2-type structure of NCM811 survives in the doped samples, and the lattice parameters [Formula: see text] and [Formula: see text] increase linearly with the Ti content. XPS spectra indicate that the Ni ions show a mixing state of +2 and +3, and the portion of Ni[Formula: see text] increases by the Ti doping. The cycling stability is improved evidently by a small amount of Ti doping, i.e. capacity retention of 88.3–96.9% for [Formula: see text] = 0.01–0.03 versus 64.1% for [Formula: see text] = 0 after 100 cycles at 0.1 C. Thus, the sample with [Formula: see text] = 0.01 delivers the high discharge capacity of 180.6 mAh g[Formula: see text] after 100 cycles, much greater than 116.5 mAh g[Formula: see text] of [Formula: see text] = 0. Nevertheless, more Ti doping with [Formula: see text] = 0.04–0.05 deteriorates the electrochemical performance. It illustrates the presence of optimal Ti-doping range in NCM811, which was rationalized as the synergetic effects of bond strength, Li[Formula: see text] diffusion, chemical composition and valence state of cations.
Backward, Hopf bifurcation in a heroin epidemic model with treat age⋆
Authors: Bentout Soufiane , Djilali Salih , Ghanbari Behzad
Published: November 2020

Heroin is considered as damage on the health of the individuals. In this paper, we consider a heroin epidemic model with treat age, where the inner rivalry in between the drug users for a small dose of drugs is investigated. The influence of treatment period for a drug consumer before quitting treatment is investigated, where it is obtained that the considered model can undergo backward bifurcation, which shows the possibility of having two endemic equilibriums, this type of bifurcation is discussed in terms of the basic reproduction number [Formula: see text]. The bifurcation diagram is drown in the case of an age structured model. Also, we show the existence of Hopf bifurcation is shown under suitable conditions on the model parameters. The obtained mathematical results are confirmed numerically.
Multivariate Forecasting of Road Accidents Based on Geographically Separated Data
Authors: Meißner Katherina , Rieck Julia
Published: November 2020

As road accidents are the leading cause of death for young adults all over the world, it is necessary for the police to evaluate the accident circumstances carefully in order to take appropriate prevention measures. The circumstances of an accident vary in their frequency over time and depend on the local conditions at the accident site. An evaluation under geographical and temporal aspects is therefore necessary. On the basis of the time series, we investigate the various accident circumstances, which show interdependencies with each other, and their influence on the number of accidents. Moreover, a multivariate forecasting is used to indicate the future progression of accidents in different geographical regions. Forecast values are determined with a special extension of the ARIMA method. In order to identify geographical regions of interest, we present two different concepts for segmentation of accident data, which allow the adaptation of police measures to local characteristics.
Capturing implied correlation skew from options prices via multiscale stochastic volatility models
Authors: Pellegrino T.
Published: November 2020

The aim of this paper is to derive a second-order asymptotic expansion for the price of European options written on two underlying assets, whose dynamics are described by multiscale stochastic volatility models. In particular, the second-order expansion of option prices can be translated into a corresponding expansion in implied correlation units. The resulting approximation for the implied correlation curve turns out to be quadratic in the log-moneyness, capturing the convexity of the implied correlation skew. Finally, we describe a calibration procedure where the model parameters can be estimated using option prices on individual underlying assets.
Developing a Parental-Friendly Scoring System for Children with Congenital Hand Differences
Authors: Lam Wee Leon , Trew Christopher Arthur James , Wong Lauren , Gall Christopher , Duncan Orla , Teo Isabel
Published: November 2020

Background: Congenital hand differences (CHD) exhibit enormous diversity and heterogeneity. Surgeons and parents often have different concepts of severity, making things difficult during parental consultation. This study aims to align surgeon/parental views on the severity of the child’s CHD using a novel severity classification.

Methods: Parents of affected children were asked to score the severity of their child’s abnormality pre- and post-consultation using a subjective scale (1–4) without any explanation. Furthermore, parents were asked to rate their concerns about the future function and appearance of their child’s hand condition using a similar scale of 1–4. They were then asked to rate the severity of the CHD post-consultation and three months post-operatively following explanation of the 4-point scale, as follows: 1 = treatment possible to normal; 2 = treatment possible to near normal; 3 = treatment possible but always some hand differences; 4 = treatment not possible. The surgeon also independently scored all children using his perception of the scale.

Results: Forty-three children with a range of CHD were recruited into the sample. Linear weighted kappa analyses comparing inter-rater agreement showed no agreement between surgeon and parents during the initial scoring without any explanations. However, with explanations added, agreement rose significantly (kappa = 0.437 post-consultation and kappa = 0.706 three months post-op). No correlation was found between severity with both appearance and function (r = 0.277 and r = −0.184, respectively).

Conclusions: This study demonstrated that the use of a simple scoring system was able to improve parental understanding of the severity and prognosis of CHD. The system demonstrated a good correlation between surgeon and parents. Such a scoring system can be easily utilised in the outpatient department to manage expectations and reduce anxiety.
Follicular Fluid Meiosis-Activating Sterol in Assisted Reproductive Techniques: A Systematic Review and Meta-analysis of Randomized Controlled Trials
Authors: Dang Kien Nguyen , Hashan Mohammad Rashidul , Minh Le Huu Nhat , Khalaf Khalid Muhammad , Ibrahim Hassan Yousif , Dessi Alberto , Azzam Mohamed Abdalla , Loc Tran Thai Huu , Hirayama Kenji , Huy Nguyen Tien
Published: November 2020

Background: Follicular fluid meiosis-activating sterol (FFMAS) is one of several molecular compounds that has been added into in vitro maturation (IVM) technique with contradictory results. Our study aimed to investigate the effects of FFMAS in assisted reproductive technology (ART).

Methods: We searched systematically in PubMed, Web of Science, Scopus, Cochrane Registry of clinical trials, WHO registry of clinical trials, clinicaltrials.gov, Google Scholar until July 2017. Meta-analysis was used to investigate the efficacy and safety outcomes of FFMAS. Following the retrieval of potential articles, two independent reviewers screened and extracted included papers rigorously. Summary odds ratios (ORs) and 95% confidence intervals (CIs) were computed for the individual outcome when data was available. Quality of included studies was assessed using Cochrane collaboration tool.

Results: A total of seven randomized controlled trials involving 1198 participants with 3105 oocytes were explored in this study. Most of the studies were at low risk of bias. Our random effects model meta-analyses in maturation and abnormal embryo rate between FFMAS-exposed oocytes compared with controls revealed no significant differences (summary OR 1.00, 95% CI 0.46–2.16, [Formula: see text] value = 0.99 and summary OR was 1.31, 95% CI 0.84–2.04, [Formula: see text] value = 0.23, respectively). Beside, our study showed a significant increase in uniformly abnormal embryo rate in FFMAS group compared with vehicle control group (summary OR 1.98, 95% CI 1.09–3.61, [Formula: see text] value = 0.03). No significances were noted on meta-analyses of normal embryo rate, uniformly abnormal embryo rate, uniformly normal embryo rate, mosaic embryo rate, abnormal blastomere rate, normal blastomere rate, aneuploidy mosaic embryo rate, and chaotic mosaic embryo rate.

Conclusions: FFMAS showed no efficacy in maturation process in human oocytes and there was some evidence for detrimental effects in comparison to vehicle controls. We discouraged any further trials due to safety concern.
On Private Peering Agreements between Content and Access Providers
Authors: Wang Xin , Ma Richard T. B.
Published: November 2020

Driven by the rapid growth of content traffic and the demand for service quality, Internet content providers (CPs) have started to bypass transit providers and connect with access providers directly via private peering agreements. This peering relationship often raises disputes, e.g., Netflix vs. Comcast, and is not well understood. In this paper, we build a peering contract model and propose the concept of contractual equilibrium, based on which we study the formation and evolution of peering contracts. By using market data, we emulate the strategic peering behavior of providers and shed light on the understanding of private peering agreements. We reveal that the superiority and market dominance of providers primarily determine their peering strategies. We show that 1) superior providers tend to engage in peering more aggressively, and 2) non-dominant CPs' optimal peering strategies are negatively correlated due to market cannibalism, while the dominant CP often behaves oppositely. Our findings help explain phenomena such as why Netflix and Comcast signed the first peering contract, and reason whether private peering contracts will strengthen in future.
Achieving Zero Asymptotic Queueing Delay for Parallel Jobs
Authors: Weng Wentao , Wang Weina
Published: November 2020

Zero queueing delay is highly desirable in large-scale computing systems. Existing work has shown that it can be asymptotically achieved by using the celebrated Power-of-d-choices (pod) policy with a probe overhead $d = ømegałeft(\fracłog N 1-łambda \right)$, and it is impossible when $d = Ołeft(\frac1 1-łambda \right)$, where N is the number of servers and $łambda$ is the load of the system. However, these results are based on the model where each job is an indivisible unit, which does not capture the parallel structure of jobs in today's predominant parallel computing paradigm. This paper thus considers a model where each job consists of a batch of parallel tasks. Under this model, we propose a new notion of zero (asymptotic) queueing delay that requires the job delay under a policy to approach the job delay given by the max of its tasks' service times, i.e., the job delay assuming its tasks entered service right upon arrival. This notion quantifies the effect of queueing on a job level for jobs consisting of multiple tasks, and thus deviates from the conventional zero queueing delay for single-task jobs in the literature. We show that zero queueing delay for parallel jobs can be achieved using the batch-filling policy (a variant of the celebrated \pod\ policy) with a probe overhead $d = ømegałeft(\frac1 (1-łambda)łog k \right)$ in the sub-Halfin-Whitt heavy-traffic regime, where k is the number of tasks in each job and k properly scales with N (the number of servers). This result demonstrates that for parallel jobs, zero queueing delay can be achieved with a smaller probe overhead. We also establish an impossibility result: we show that zero queueing delay cannot be achieved if $d = \expłeft(ołeft(\fracłog N łog k \right) \right)$. Simulation results are provided to demonstrate the consistency between numerical results and theoretical results under reasonable settings, and to investigate gaps in the theoretical analysis.
Achievable Stability in Redundancy Systems
Authors: Raaijmakers Youri , Borst Sem
Published: November 2020

We consider a system with N~parallel servers where incoming jobs are immediately replicated to, say, d~servers. Each of the N servers has its own queue and follows a FCFS discipline. As soon as the first job replica is completed, the remaining replicas are abandoned. We investigate the achievable stability region for a quite general workload model with different job types and heterogeneous servers, reflecting job-server affinity relations which may arise from data locality issues and soft compatibility constraints. Under the assumption that job types are known beforehand we show for New-Better-than-Used (NBU) distributed speed variations that no replication $(d=1)$ gives a strictly larger stability region than replication $(d>1)$. Strikingly, this does not depend on the underlying distribution of the intrinsic job sizes, but observing the job types is essential for this statement to hold. In case of non-observable job types we show that for New-Worse-than-Used (NWU) distributed speed variations full replication ($d=N$) gives a larger stability region than no replication $(d=1)$.
Competitive Algorithms for the Online Multiple Knapsack Problem with Application to Electric Vehicle Charging
Authors: Sun Bo , Zeynali Ali , Li Tongxin , Hajiesmaili Mohammad , Wierman Adam , Tsang Danny H.K.
Published: November 2020

We introduce and study a general version of the fractional online knapsack problem with multiple knapsacks, heterogeneous constraints on which items can be assigned to which knapsack, and rate-limiting constraints on the assignment of items to knapsacks. This problem generalizes variations of the knapsack problem and of the one-way trading problem that have previously been treated separately, and additionally finds application to the real-time control of electric vehicle (EV) charging. We introduce a new algorithm that achieves a competitive ratio within an additive factor of one of the best achievable competitive ratios for the general problem and matches or improves upon the best-known competitive ratio for special cases in the knapsack and one-way trading literatures. Moreover, our analysis provides a novel approach to online algorithm design based on an instance-dependent primal-dual analysis that connects the identification of worst-case instances to the design of algorithms. Finally, we illustrate the proposed algorithm via trace-based experiments of EV charging.
Bregman-style Online Convex Optimization with EnergyHarvesting Constraints
Authors: Asgari Kamiar , Neely Michael J.
Published: November 2020

This paper considers online convex optimization (OCO) problems where decisions are constrained by available energy resources. A key scenario is optimal power control for an energy harvesting device with a finite capacity battery. The goal is to minimize a time-average loss function while keeping the used energy less than what is available. In this setup, the distribution of the randomly arriving harvestable energy (which is assumed to be i.i.d.) is unknown, the current loss function is unknown, and the controller is only informed by the history of past observations. A prior algorithm is known to achieve $O(\sqrtT )$ regret by using a battery with an $O(\sqrtT )$ capacity. This paper develops a new algorithm that maintains this asymptotic trade-off with the number of time steps T while improving dependency on the dimension of the decision vector from $O(\sqrtn )$ to $O(\sqrtłog(n) )$. The proposed algorithm introduces a separation of the decision vector into amplitude and direction components. It uses two distinct types of Bregman divergence, together with energy queue information, to make decisions for each component.
Concentration Dependent Solution Structure and Transport Mechanism in High Voltage LiTFSI–Adiponitrile Electrolytes
Authors: Franko Christopher J. , Yim Chae-Ho , Årén Fabian , Åvall Gustav , Whitfield Pamela S. , Johansson Patrik , Abu-Lebdeh Yaser A. , Goward Gillian R.
Published: November 2020

The physiochemical properties of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) in adiponitrile (ADN) electrolytes were explored as a function of concentration. The phase diagram and ionic conductivity plots show a distinct relationship between the eutectic composition of the electrolyte and the concentration of maximum ionic conductivity in the 25 °C isotherm. We propose a structure-based explanation for the variation of electrolyte ionic conductivity with LiTFSI concentration, where the eutectic concentration is a transitionary region at which the structure changes from solvated contact ion pairs to extended units of [Liz(ADN)xTFSIy]z−y aggregates. It is found through diffusion coefficient measurements using pulsed-field gradient (PFG) NMR that both

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increase with concentration until 2.9 M, where after Li+ becomes the fastest diffusing species, suggesting that ion hopping becomes the dominant transport mechanism for Li+. Variable diffusion-time (Δ) PFG NMR is used to track this evolution of the ion transport mechanism. A differentiation in Li+ transport between the micro and bulk levels that increases with concentration was observed. It is proposed that ion hopping within [Liz(ADN)xTFSIy]z−y aggregates dominates the micro-scale, while the bulk-scale is governed by vehicular transport. Lastly, we demonstrate that LiTFSI in ADN is a suitable electrolyte system for use in Li-O2 cells.
Elucidation of Fluid Streamlining in Multi-Layered Porous Transport Layers for Polymer Electrolyte Water Electrolyzers by Operando Neutron Radiography
Authors: Zlobinski Mateusz , Schuler Tobias , Büchi Felix N , Schmidt Thomas J. , Boillat Pierre
Published: November 2020

Developments of the porous transport layers (PTLs) in recent years resulted in significant performance improvements in polymer electrolyte water electrolyzers (PEWEs). One of the milestones of the material design was the integration of a microporous layer (MPL) on sintered titanium PTLs. Utilizing high-resolution neutron imaging, the water and gas distribution in the multi-layered porous transport media (ML-PTL) was probed at various current densities (up to 4 A cm−2) and pressure conditions up to 8 bar, using a series of four materials, differing in MPL morphology. The water and gas distribution measured is greatly affected by the presence of an MPL. While in the bulk of the PTL, the gas accumulation is increased in the presence of an MPL, in the MPL itself more water is retained. The finer the MPL structure, the higher the liquid saturation. It is observed that the two-phase flow in the MPL has minor influence on the performance of the cell even though the gas accumulation at the CL interface is greatly reduced. The improvements, therefore, appear to be related to the CL and MPL interaction on sub-micron scale and microstructure effect on catalyst area utilization.
Contamination Mechanism of Ceria Particles on the Oxide Surface after the CMP Process
Authors: Han Kwang-Min , Han So-Young , Sahir Samrina , Yerriboina Nagendra Prasad , Kim Tae-Gon , Mahadev Niraj , Park Jin-Goo
Published: November 2020

The contamination behavior of ceria particles (50 and 100 nm) with oxide surfaces at pH 4 and 8 was studied using dipping and polishing conditions. Higher contamination at pH 4 than pH 8 was observed for dipping cases. In contrast, pH 8 conditions produced higher contamination than pH 4 for polishing cases. The difference in the contamination between dipping and polishing could be attributed to electrostatic attraction and chemical bonding. During polishing, weak or no chemical bonding may occur at pH 4, whereas the Ce–O–Si bond may form due to the surface charges of ceria and silica at pH 8. XPS analysis revealed that strong additional peaks related to Ce–O–Si bonding were detected for O 1s spectra at a binding energy of around 532 eV for surfaces polished at pH 8. Similar results were observed for 50 nm as well as 100 nm ceria particles. Based on the results, we concluded that ceria particles would have different adhesion behaviors for dipping and polishing at the same pH value. Also, higher ceria adhesion was observed at higher pH compared to lower pH during the CMP process, which was correlated to strong Ce–O–Si chemical bond formation due to the CMP conditions.