bluuebunny/crossref_metadata_2025 huggingface dataset:
Data-driven planning via imitation learning
Authors: Choudhury Sanjiban , Bhardwaj Mohak , Arora Sankalp , Kapoor Ashish , Ranade Gireeja , Scherer Sebastian , Dey Debadeepta
Published: July 2018

Robot planning is the process of selecting a sequence of actions that optimize for a task=specific objective. For instance, the objective for a navigation task would be to find collision-free paths, whereas the objective for an exploration task would be to map unknown areas. The optimal solutions to such tasks are heavily influenced by the implicit structure in the environment, i.e. the configuration of objects in the world. State-of-the-art planning approaches, however, do not exploit this structure, thereby expending valuable effort searching the action space instead of focusing on potentially good actions. In this paper, we address the problem of enabling planners to adapt their search strategies by inferring such good actions in an efficient manner using only the information uncovered by the search up until that time. We formulate this as a problem of sequential decision making under uncertainty where at a given iteration a planning policy must map the state of the search to a planning action. Unfortunately, the training process for such partial-information-based policies is slow to converge and susceptible to poor local minima. Our key insight is that if we could fully observe the underlying world map, we would easily be able to disambiguate between good and bad actions. We hence present a novel data-driven imitation learning framework to efficiently train planning policies by imitating a clairvoyant oracle: an oracle that at train time has full knowledge about the world map and can compute optimal decisions. We leverage the fact that for planning problems, such oracles can be efficiently computed and derive performance guarantees for the learnt policy. We examine two important domains that rely on partial-information-based policies: informative path planning and search-based motion planning. We validate the approach on a spectrum of environments for both problem domains, including experiments on a real UAV, and show that the learnt policy consistently outperforms state-of-the-art algorithms. Our framework is able to train policies that achieve up to [Formula: see text] more reward than state-of-the art information-gathering heuristics and a [Formula: see text] speedup as compared with A* on search-based planning problems. Our approach paves the way forward for applying data-driven techniques to other such problem domains under the umbrella of robot planning.
Management of an iatrogenic injury to the tibial nerve in a 24-year-old hurdle runner
Authors: Kowalska Joanna , Grabowski Radoslaw , Pigonska Justyna , Domzalski Marcin
Published: July 2018

According to previously published papers, neurovascular injuries seem to be the most unfortunate complications after surgical procedures. In this report, we present our therapeutic approach to iatrogenic injury of the posterior tibial nerve that occurred during ankle arthroscopy in a 24-year-old patient. The outcome of the therapy was a full sensory return and partial motor return (S4 and M3 according to the Medical Research Council Grading System for Nerve Recovery). Our patient was able to resume her typical training. In comparison with available reports, our therapeutic approach enabled earlier functional recovery after nerve injury. While sensory return is beneficial, motor improvement is also important. However, we are conscious of the poor functional outcomes reported by other researchers.
Tetramethylpyrazine protects against high glucose-induced vascular smooth muscle cell injury through inhibiting the phosphorylation of JNK, p38MAPK, and ERK
Authors: Liu Yutao , Li Xu , Jiang Shanling , Ge Quanli
Published: July 2018

Objectives

High glucose-induced alterations in vascular smooth muscle cell behavior have not been fully characterized. We explored the protective mechanism of tetramethylpyrazine (TMP) on rat smooth muscle cell injury induced by high glucose via the mitogen-activated protein kinase (MAPK) signaling pathway.

Methods

Vascular smooth muscle cells (VSMCs) isolated from rat thoracic aortas were divided into control, high glucose (HG), and pre-hatching TMP groups. The effect of different glucose concentrations on cell viability and on the migration activity of VSMC cells was examined using MTT analysis and the wound scratch assay, respectively. Superoxide dismutase (SOD) and malondialdehyde (MDA) levels were measured using enzyme-linked immunoassays. The levels of extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and p38MAPK, and MAPK phosphorylation were assessed by western blotting.

Results

Cell proliferation was remarkably increased by increased glucose concentrations. Compared with the HG group, the migratory ability of VSMC cells was reduced in the presence of TMP. TMP also decreased the MDA content in the supernatant, but significantly increased the SOD activity. Western blotting showed that TMP inhibited the phosphorylation of JNK, p38MAPK, and ERK.

Conclusions

TMP appears to protect against HG-induced VSMC injury through inhibiting reactive oxygen species overproduction, and p38MAPK/JNK/ERK phosphorylation.
Knowledge database assisted gene marker selection for chronic lymphocytic leukemia
Authors: Xiang Xixi , Wang Yu-Ping , Cao Hongbao , Zhang Xi
Published: July 2018

Objective

To investigate whether previously curated chronic lymphocytic leukemia (CLL) risk genes could be leveraged in gene marker selection for the diagnosis and prediction of CLL.

Methods

A CLL genetic database (CLL_042017) was developed through a comprehensive CLL-gene relation data analysis, in which 753 CLL target genes were curated. Expression values for these genes were used for case-control classification of four CLL datasets, with a sparse representation-based variable selection (SRVS) approach employed for feature (gene) selection. Results were compared with outcomes obtained by using analysis of variance (ANOVA)-based gene selection approaches.

Results

For each of the four datasets, SRVS selected a subset of genes from the 753 CLL target genes, resulting in significantly higher classification accuracy, compared with randomly selected genes (100%, 100%, 93.94%, 89.39%). The SRVS method outperformed ANOVA in terms of classification accuracy.

Conclusion

Gene markers selected from the 753 CLL genes could enable significantly greater accuracy in the prediction of CLL. SRVS provides an effective method for gene marker selection.
Male-on-Female Sexual Homicides in Sweden, 1990 to 2013: A Population-Based Controlled Study of Incidents, Victims, and Offenders
Authors: Sturup Joakim , Rodre Sara , Karlberg Daniel , von Vogelsang Eva , Rying Mikael , Caman Shilan
Published: July 2018

To date, systematic studies of sexual homicides from Europe are scarce, in which none have been conducted in Sweden. This study aims to describe male-on-female sexual homicides in Sweden and differentiate from corresponding nonsexual homicides. Unsolved and solved sexual homicide ( n = 33) cases were identified in a database containing all homicides in Sweden between 1990 and 2013 ( N = 2,126), and subsequently data from forensic psychiatric evaluations were collected for convicted offenders. Male-on-female sexual homicides constituted 1.6% of all homicides and the clearance rate was 82%, which is comparable with the 83% overall clearance rate but took longer time to solve. Three factors differentiated sexual from nonsexual homicides: strangulation, younger age of the victim, and the absence of eyewitnesses. In solved cases, distance from the offender’s home to the crime scene was strongly correlated with time to clearance. A majority of the offenders suffered from personality disorders, while other diagnoses were uncommon.
Magneto-mechanical analysis of magnetic gear pole pieces ring from analytical models for wind turbine applications
Authors: Desvaux M , Multon B , Ahmed H Ben , Sire S
Published: July 2018

This article deals with the structural behavior of a multi-bar system which maintains pole pieces in a concentric magnetic gear. Simplified analytic magnetic and mechanical models of the system are proposed in order to be integrated in a multi-criteria global optimization for the sizing of a magnetic gear in wind power applications. For this purpose, the reduction of the computation time is taken into account. The geometry of the support bar subsystem is defined and a Q bar structure is proposed. The magnetic study is based on Maxwell’s equations and subdomain method in order to determine variable radial and tangential magnetic loads. The mechanical study is based on a multibody model with different bars stiffnesses which are determined from a one-dimensional model. Variable radial and tangential magneto-mechanical pole pieces loads (magnetic load and weight) are also considered. An example of a magnetic gear with 172 pole pieces (i.e. 6-MW wind turbine) is proposed to analyze the mechanical behavior and also the computation time.
Transition piece design for an onshore hybrid wind turbine with multiaxial fatigue life estimation
Authors: Farhan Muhammad , Mohammadi Mohammad Reza Shah , Correia José António , Rebelo Carlos
Published: July 2018

Steel tubular structures are somewhat entrenched for the wind turbine towers. Recently, steel hybrid lattice/tubular towers are being investigated as a conceivable answer for taller onshore wind turbines for which convectional steel tubular towers are less competitive. Hybrid lattice/tubular towers require a transition piece which serves as a connection between lattice and tubular part. As the transition piece is supposed to transfer all the dynamic and self-weight loads to the lattice and foundation, these structural elements present unique features and are critical components to design and ought to resist strong cyclic bending moments, shear forces, and axial loads. Well-designed transition pieces with optimized ultimate state and fatigue capacities for manufacturing contribute to the structural soundness, reliability, and practicability of new onshore wind turbines hybrid towers. This research focuses on the investigation of the transition piece for an onshore wind turbine hybrid tower. The 5-MW reference wind turbine and a hybrid lattice/tubular tower were simulated in the servo-hydro aero-elastic analysis tool (by ASHES software) from which the loads and dynamic response of the supporting structure were obtained. Cross-sectional forces at the transition piece elevation were calculated and the connection with the lattice structure is designed. The transition piece was designed by finite element model considering ultimate limit load and fatigue load, using nonlinear analysis and multiaxial fatigue for life-time prediction, respectively. Multiaxial fatigue life was calculated based on Brown–Miller and Smith–Watson–Topper methods. In comparison, Smith–Watson–Topper method comes out to be more conservative. Potential of using high-strength steel S690 was investigated.
Epidemiology of migraine in men: Results from the Chronic Migraine Epidemiology and Outcomes (CaMEO) Study
Authors: Scher Ann I , Wang Shuu-Jiun , Katsarava Zaza , Buse Dawn C , Fanning Kristina M , Adams Aubrey Manack , Lipton Richard B
Published: July 2018

Objective

To assess migraine epidemiology in men by examining gender differences in disease presentation, comorbidities, and prognosis.

Patients and methods

The Chronic Migraine Epidemiology and Outcomes (CaMEO) Study is a longitudinal survey of US adults with migraine identified by web questionnaire. Data were stratified by gender, collected between September 2012–November 2013, and included sociodemographics, headache features, Migraine Disability Assessment, Migraine Symptom Severity Score, Allodynia Symptom Checklist, and comorbidities. Discrete time hazard models addressed 1-year likelihood of transition from episodic to chronic migraine headache frequency.

Results

Of the 16,789 migraine respondents, 4294 were men (25.6%). Compared to women, men were slightly older at onset of their headaches (mean 24.1 vs. 22.3 years) and had fewer headache days/month (4.3 vs. 5.3 days), slightly less severe attacks (Migraine Symptom Severity Score, 21.6 vs. 22.6), reduced frequencies of grade IV Migraine Disability Assessment scores (15.7% vs. 24.1%), allodynia (32.6% vs. 49.7%), chronic migraine (6.5% vs. 9.6%, each p < 0.001), and common comorbidities. Men were less likely to report consulting a doctor for their headaches and receiving a migraine diagnosis if they consulted. Men and women with episodic migraine had similar crude 1-year risk of chronic migraine onset. Controlling for known risk factors (i.e. depression, headache frequency, allodynia), men had greater likelihood of chronic migraine onset at 6, 9, and 12 months (each p < 0.05).

Conclusions

Findings confirmed gender differences. Men with migraine generally have less severe attacks and disability and are less likely to receive a diagnosis than women with migraine. Prognostic factors may be better understood for women than men.
Characteristics Analysis and Modeling of Emissions for Bus with Liquefied Natural Gas Fuel System in Real World Driving
Authors: Pan Yingjiu , Chen Shuyan , Qiao Fengxiang , Zhang Bin , Li Saisai
Published: July 2018

To estimate accurately the emission rates of buses fueled with a liquefied natural gas (LNG) system, a method capturing the emission characteristics of LNG buses is proposed. In previous studies, vehicle specific power (VSP), a good indicator for instantaneous power demand on engines, has been mostly used in analyzing the emission characteristics of traditional vehicles such as passenger cars, diesel buses and heavy-duty trucks, with less effort on new energy buses, especially LNG buses. Based on the characteristic analyses in this study, it does not accurately describe the emission characteristics of LNG buses if the operating condition is classified only according to VSP. In this paper, we identify that the factors significantly affecting emissions are both speed and VSP using correlation analysis. Then a two-dimensional algorithm is proposed to divide operating conditions into several operating bins based on speed and VSP, and the validity of this method is verified by comparing the measured values of emissions between a training dataset and a test dataset. Based on the analysis of emission characteristics in two-dimensional operating bins, a regression model for estimating emission rates of LNG buses is established. The feasibility and accuracy of the model are validated by using a test dataset. The results indicate that all the relative errors between measured values and estimated values are within 16%, and the values of normalized mean square error (NMSE) are close to zero, indicating that the model established based on both speed and VSP can be applied to the estimation of LNG bus emissions.
A New Control Strategy Integrated into the Desired Safety Margin Car-Following Model Considering the Disturbance Level
Authors: Zhang Junjie , Wang Yunpeng , Lu Guangquan
Published: July 2018

A vehicular communication system can provide motion information based on various sensors. Thus, adaptive cruise control (ACC) systems based on a reliable communication system can relieve traffic congestion in a platoon. However, acquiring vehicle information entails uncertainties because the disturbance of traffic environment and vehicular communication systems influences vehicle control performance. In this study, the desired safety margin (DSM) model is employed to investigate the influence of uncertainty on car-following performance, such as starting, emergency braking, and car-following processes. Based on the DSM model, the disturbance level on perceived safety margin is introduced to characterize the uncertainty of vehicle information. The stability criterion of the DSM model with the disturbance level is derived via linear stability theory. Analytical results indicate that a negative value of disturbance level will enlarge the stable region. By contrast, a positive value is conducive for maintaining the consensus state and achieving the high acceleration and deceleration of following vehicles in the starting process. Findings show that disturbance in the vehicular system significantly influences car-following performance. To enhance the smoothness and stability of traffic flow evolution, a new control strategy is proposed in this study. Numerical experiments illustrate the effectiveness of the proposed control strategy in stabilizing traffic flow. This study highlights the need to resolve the stability of sensors and vehicular communication systems, and develop a vehicular controller to help ACC system improve vehicle control performance in the car-following process.
Assistive System to Improve Pedestrians’ Safety and Mobility in a Connected Vehicle Technology Environment
Authors: Khosravi Sara , Beak Byungho , Head K. Larry , Saleem Faisal
Published: July 2018

Conflicts between vehicles and vulnerable road users (VRUs) often result in injuries and fatalities. This paper presents a vehicle-to-infrastructure and Wi-Fi based pedestrian conflict avoidance system to improve VRUs’ safety. Compared with the vision based systems, the proposed system can improve VRUs’ safety in non-line-of-sight situations. In particular, it can be helpful in a situation when drivers are making a right or left turn where there is a crosswalk and visibility conditions are poor. The system, called Smart Walk Assistant (SWA), was implemented as an application on a smartphone and server on a roadside unit. It includes two wireless communication pathways: pedestrian-to-infrastructure (P2I) and pedestrian-to-vehicle (P2V). The first communication pathway enables users to send a pedestrian signal request to the traffic signal controller and receive traffic signal status. The second communication pathway enables pedestrians and vehicles to exchange information including location, speed, and heading that can be used to provide conflict alerts. The SWA system may be especially beneficial to differently abled pedestrians, including blind or visually impaired pedestrians, who would benefit from active support to safely cross streets at signalized intersections. The P2I application was designed, developed, and field demonstrated. The P2V application was designed and developed, and will be field tested in the near future.
Resurrecting the Lost Vehicle Trajectories of Treiterer and Myers with New Insights into a Controversial Hysteresis
Authors: Coifman Benjamin , Li Lizhe , Xiao Wen
Published: July 2018

The 1974 paper by Treiterer and Myers is a seminal work in traffic flow theory. This longevity is in part because of the impressive collection of manually extracted vehicle trajectories. To date, only a few studies have rivaled the scale of the empirical vehicle trajectory data used in Treiterer and Myers. Their data collection used high-speed aerial photography and manual data reduction to follow hundreds of vehicles. In spite of the Herculean collection effort, the trajectory data set was never released and has since been lost. Fortunately, the plots survive and the present work re-extracts the vehicle trajectory data from the time–space diagrams. The discussion places the value of the data in context and then uses the data to put an end to decades of misinterpretation that started with Treiterer himself. The central thesis of Treiterer and Myers generated considerable interest: a hysteresis whereby drivers exhibit different fundamental behavior depending on whether they are entering or exiting a disturbance. There has been extensive debate about the authors’ findings in the literature, but without the original data set any interpretation has required considerable speculation. With the resurrected trajectories, this work reexamines the vehicles underlying the hysteresis and finally quells the speculation. Rather than arising from car following behavior, it turns out that the enigmatic progression arose from a combination of lane change maneuvers and unremarkable transitions into or out of the congested regime. On publication, the re-extracted data from this paper will be released to the research community.
Evaluation of Commercial Truck Parking Detection for Rest Areas
Authors: Sun Wei , Stoop Ethan , Washburn Scott S.
Published: July 2018

Florida’s interstate rest areas are heavily utilized by commercial trucks for overnight parking. Many of these rest areas regularly experience 100% utilization of available commercial truck parking spaces during the evening and early-morning hours. Being able to communicate availability of commercial truck parking space to drivers in advance of arriving at a rest area would reduce unnecessary stops at full rest areas as well as driver anxiety. In order to do this, it is critical to implement a vehicle detection technology to reflect the parking status of the rest area correctly. The objective of this project was to evaluate three different wireless in-pavement vehicle detection technologies as applied to commercial truck parking at interstate rest areas. This paper mainly focuses on the following aspects: (a) accuracy of the vehicle detection in parking spaces, (b) installation, setup, and maintenance of the vehicle detection technology, and (c) truck parking trends at the rest area study site. The final project report includes a more detailed summary of the evaluation. The research team recorded video of the rest areas as the ground-truth data and developed a software tool to compare the video data with the parking sensor data. Two accuracy tests (event accuracy and occupancy accuracy) were conducted to evaluate each sensor’s ability to reflect the status of each parking space correctly. Overall, it was found that all three technologies performed well, with accuracy rates of 95% or better for both tests. This result suggests that, for implementation, pricing, and/or maintenance issues may be more significant factors for the choice of technology.
Predictors of red blood cell transfusion and its association with prognosis in patients undergoing extracorporeal membrane oxygenation
Authors: Lo Pinto Hugo , Allyn Jérôme , Persichini Romain , Bouchet Bruno , Brochier Gilbert , Martinet Olivier , Brulliard Caroline , Valance Dorothée , Delmas Benjamin , Braunberger Eric , Dangers Laurence , Allou Nicolas
Published: July 2018

Purpose:

Few data are available on the potential benefits and risks of red blood cell transfusion in patients undergoing extracorporeal membrane oxygenation. The aim of this study was to identify the determinants and prognosis of red blood cell transfusion in patients undergoing extracorporeal membrane oxygenation, with a special focus on biological parameters during extracorporeal membrane oxygenation treatment.

Methods:

We conducted a single-center retrospective cohort study including all consecutive patients who underwent extracorporeal membrane oxygenation between January 2010 and December 2015.

Results:

The 201 evaluated patients received a median of 0.9 [0.5–1.7] units of red blood cell per day. Significant and clinically relevant variables that best correlated with units of red blood cell transfused per day of extracorporeal membrane oxygenation were lower median daily prothrombin time in percentage (Quick) ( t = –0.016, p < 0.0001), higher median daily free bilirubin level ( t = 0.016, p < 0.0001), and lower pH ( t = –2.434, p < 0.0001). In multivariate analysis, red blood cell transfusion was associated with a significantly higher rate of in-intensive care unit mortality (per red blood cell unit increment; adjusted odds ratio: 1.07, 95% confidence interval: 1.02–1.12, p = 0.005). It was also associated with higher rates of acute renal failure ( p = 0.025), thromboembolic complications ( p = 0.0045), and sepsis ( p = 0.015).

Conclusion:

This study suggests that red blood cell transfusion may be associated with a higher mortality rate and with severe complications. However, we cannot conclude a direct causal relationship, as red blood cell transfusion may be only a marker of poor outcome. We recommend that physicians correct acidosis and hemolysis in patients undergoing extracorporeal membrane oxygenation whenever possible.
Effect of blade curvature on the hemolytic and hydraulic characteristics of a centrifugal blood pump
Authors: Ozturk Caglar , Aka I Basar , Lazoglu Ismail
Published: July 2018

Aims:

Impeller design has a significant impact on the overall performance of a blood pump. In this study, the effect of the blade curvature was investigated by performing in silico and in vitro studies on a recently developed centrifugal blood pump.

Methods:

A computational fluid dynamics study was performed for the flow rates of 3–5 L/min at 2000 r/min. The computational fluid dynamics model was also applied on the US Food and Drug Administration (FDA) benchmark blood pump to validate our computational method. The relative hemolysis index was calculated with the Eulerian hemolysis estimation method for five impellers with the wrap angles ranging from 0° to 240°. Hydraulic experiments were conducted for the validation of computational fluid dynamics results. In addition, the curved-blade impeller (120°) and the straight-blade impeller (0°) were evaluated with in vitro hemolysis tests using human blood.

Results:

The wrap angle of 120° provided the best hydraulic and hemolytic performance. Pump achieved the physiologic operating pressures and flows with 85–115 mmHg at 2.5–5.9 L/min. Compared to the straight-blade impeller, the 120° model reduces the relative hemolysis index and the plasma-free hemoglobin near 72.8% and 56.7%, respectively. Comparison of in silico and in vitro results indicated the similar trend to the blade curvature.

Conclusion:

Introducing a blade curvature enhanced the hydrodynamic and hemolytic performance compared to the straight-blade configuration for the investigated centrifugal blood pump. The findings of this study provide new insights into centrifugal blood pump design by examining the influence of the blade curvature.
A Note on Capitalist Commodification of the Homeless
Authors: Wilson Tamar Diana
Published: July 2018

Under capitalism, the homeless are an oppressed and an exploited class. They are exploited sometimes as part of what Marx identifies as the lower reaches of the surplus labor force, but most usually through their commodification. They are subject to Althusser’s repressive and ideological state apparatuses. The long-term and recurrent homeless are commodified by being a source of both money-making employment and power among the police, the legal system, and psychiatrists and social workers.

JEL Classifications: B51, J68, O18
Assigned Roles as a Structuring Tool in Online Discussion Groups: Comparison of Transactional Distance and Knowledge Sharing Behaviors
Authors: Yilmaz Ramazan , Karaoglan Yilmaz Fatma Gizem
Published: July 2018

The purpose of this study is to determine the effects of structured discussion by giving participants in online discussion groups different roles in transactional distance perception and knowledge sharing behaviors. In the study, a quasi-experimental design was utilized with pretest and posttest control groups. The study was conducted with 111 first-year undergraduate students at a university for 10 weeks. Quantitative and qualitative data collection techniques were used in the study, and the data were obtained from the Transactional Distance Scale, Knowledge Sharing Behavior Scale, and Student Opinion Determination Form. The findings indicate that online discussions carried out by assigning roles to discussion group members (starter, moderator, arguer, source searcher, and summarizer) decreased students’ transactional distance perceptions and improved knowledge sharing behaviors in online discussions. Different suggestions are offered about how to structure online discussions in accordance with the findings of the qualitative data analysis.
Sola scriptura: Personal and Professional Reflections
Authors: Pazmiño Robert W.
Published: July 2018

The 2017 SPCE Conference theme provided the occasion to reflect upon both my life and professional journeys in relation to God’s revelation and the essential role of Scripture honoring the 500th Anniversary of the Protestant Reformation and the legacy of Martin Luther for Christian education in the third millennium.
The Transformative Learning Experiences of Southern California Church-based Small Group Members
Authors: Mikaelian Mariet
Published: July 2018

The main purpose of this research was to explore the ways the members of church-based small groups of various denominations in Southern California have experienced transformative learning, and to identify the factors that contribute to that experience. A qualified research was conducted. Purposeful sampling was used and data were collected through semi-structured interviews. A total of 22 people from six different denominations participated. Ten major themes came up as factors that foster transformative learning: relationships, Bible, God, good examples, problems, ministry, Christian literature, willingness, preaching of the church, and church retreats. Implications are presented at the end.
Visualisation of the insertion of a membrane for the treatment of preterm rupture of fetal membranes using a synthetic model of a pregnant uterus
Authors: Roman Sabiniano , Hillary Christopher , Narice Brenda , Bullock Anthony J , Anumba Dilly OC , MacNeil Sheila
Published: July 2018

Preterm premature rupture of fetal membranes is a leading cause of preterm delivery. Preterm labour can compromise fetal survival, and even if a pregnancy affected by preterm premature rupture of fetal membrane continues, major complications associated with leakage of amniotic fluid and risk of infection can affect the normal development and survival of the baby. There are limited management options for preterm premature rupture of fetal membrane other than delivery of the baby if ascending infection (chorioamnionitis) is suspected. We have previously reported the development and characterisation of an implantable membrane with the aim of using it to occlude the internal os of the cervix, in order to prevent amniotic fluid loss, allow fluid reaccumulation and reduce the risk of chorioamnionitis. For this, an electrospun biocompatible and distensible bilayer membrane was designed with mechanical properties similar to the human amniotic membrane. In this study, we consider the effects of sterilization on the membrane, how to insert the membrane and visualise it using routine clinical methods. To do this, we used e-beam sterilisation and examined the ability of the membrane to adhere to ex vivo human cervical tissues. We also studied its insertion into a custom-synthesised model of a 20-week pregnant uterus and imaged the membrane using ultrasound.

Sterilisation produced minor effects on physical and mechanical properties, but these did not affect the capacity of the membrane to be sutured or to provide a fluid barrier. We demonstrated that fibrin glue can successfully adhere the bilayer membrane to cervical tissues. Finally, we demonstrated that the membrane can be inserted through the cervix as well as visualized in place using ultrasound imaging and an endoscope.

In summary, we suggest this membrane is a candidate for further development in an appropriate animal model, supported by appropriate imaging, to precede possible future human studies if judged to demonstrate satisfactory safety and efficacy profiles.
Intimate Partner Violence Victimization and Perpetration in a Turkish Female Sample: Rejection Sensitivity and Hostility
Authors: Kahya Yasemin
Published: July 2018

Intimate partner violence (IPV) against women is one of the most alarming social problems all over the world. Recently, IPV research focuses on the bidirectional nature of the phenomenon, which underlines that both women and men can equally be victims and perpetrators of IPV, especially in community samples. The cycle of violence theory asserts that child abuse and neglect (CAN) is a vulnerability factor for being both a victim and perpetrator of IPV while developmental mechanisms perspective assesses mediators explaining this association. The purpose of the current study was to investigate whether CAN and each type of CAN (emotional maltreatment, physical abuse and neglect, and sexual abuse) would be associated with victimization of and perpetration by women via the multiple mediator roles of rejection sensitivity and hostility after controlling for co-occurring CAN types. The sample ( N = 288) included Turkish women who were currently married or in a romantic relationship or in one of these statutes in the past year. Participants were recruited via online survey to fill out the related questionnaires. The results of Bootstrap analyses showed that the total CAN scores were associated with being a victim and perpetrator of IPV in the past year. Rejection sensitivity mediated the association between CAN and being a victim of IPV while hostility was a mediator between CAN and perpetration of IPV. Childhood emotional maltreatment (CEM) was the only trauma type which predicted victimization by rejection sensitivity and perpetration by hostility above and beyond the effects of co-occurring trauma types. The present study findings contributed to the growing literature that women exposed to childhood traumas can also be perpetrators of violence that was a demonstrated risk factor for the repeated victimization. Results implied that developmental and process variables should be taken into account rather than a strict gendered analysis of IPV in research and clinical practice.
Exposure to Family and Friend Homicide in a Nationally Representative Sample of Youth
Authors: Turner Heather A. , Finkelhor David , Henly Megan
Published: July 2018

This study examines the lifetime prevalence and distribution of family/friend homicide exposure among children and adolescents age 2 to 17 in the United States, and assesses the impact of family/friend homicide on emotional and behavioral outcomes, while controlling for potential co-occurring factors. Data were collected by telephone about the experiences of youth in 2008, 2011, or 2014, as part of the National Surveys of Children’s Exposure to Violence (NatSCEV). Analyses are based on a pooled sample ( n =11,771) from these three surveys. Approximately 8% of all children and youth ages 2 to 17 were exposed to a family/friend homicide. Older adolescents, Black youth, those living in single parent and nonparent family households, those from lower socioeconomic status households, and youth living in large cities were overrepresented among youth experiencing family or friend homicide. Exposed youth were also substantially more likely to be poly-victims, experience other major adversities, and live in neighborhoods with more community disorder. Exposure to family/friend homicide was significantly related to trauma symptoms. However, when other co-occurring factors were taken into account, only family/friend homicide that occurred within the last 2 years remained significant. With respect to delinquency, only nonfamily homicide exposure remained significant with these other factors controlled. Findings suggest that family/friend homicide represents a powerful marker for a broad level of victimization risk and adversity, demonstrating that family/friend murder is often just one relatively small part of a more complicated life of adversity. Although recent exposure is certainly distressing to youth, it is the wider, co-occurring context of poly-victimization and other types of adversity that appears most impactful in the longer term.
Evaluation of a Worksite-Based Small Group Team Challenge to Increase Physical Activity
Authors: Tullar Jessica M. , Walker Timothy J. , Page Timothy F. , Taylor Wendell C. , Roman Rolando , Amick Benjamin C.
Published: July 2018

Purpose:

To investigate whether participants in a small group team challenge had greater completion rates in an institution-wide step-challenge than other participants.

Design:

A quasi-experimental, posttest-only design with a comparison group was used to evaluate group differences in completion rates.

Setting:

A large university system provided the opportunity to participate in a physical activity challenge.

Participants:

The study was limited to employees who participated in the physical activity challenge.

Intervention:

Two institutions offered participants the chance to compete as smaller groups of teams within their institution. These team-challenge participants (N = 414) were compared to participants from the same institutions that did not sign up for a team and tracked their steps individually (N = 1454).

Measures:

Participants who reported 50 000 steps per week for 5 of the 6 weeks were classified as challenge completers. We also evaluated total step count and controlled for several potential covariates including age, gender, and body mass index.

Analysis:

Logistic regression was used to model the dichotomous outcome of challenge completion.

Results:

Team-challenge participants were more likely to complete the physical activity challenge than other participants. Team-challenge participants had 1922 more steps per day than individual participants. However, at an institution level, overall completion rates were not higher at institutions that offered a team challenge.
A novel method to improve the cold starting ability of a low compression ratio diesel engine through recompression of the charge
Authors: Vivegananth M , Ramesh A
Published: July 2018

Reducing the compression ratio in a diesel engine will result in lower NOx and soot emissions but will lead to problem of starting and combustion instability at cold conditions. In this work, a novel method for improving cold starting ability has been conceptualized and verified through simulations and experiments. In this method, the temperature of the charge is enhanced by ejecting the hot air into the intake manifold at the end of compression stroke. Due to the irreversibility associated with this process, the temperature of the air in the intake manifold increases and this air is again inducted into the cylinder and compressed to further augment the temperature. This cycle is repeated till the temperature at the end of compression is sufficient to autoignite the injected fuel to aid first firing. This methodology was demonstrated on a single cylinder common rail diesel engine with a compression ratio of 14:1, which indicated that the temperature in the intake manifold progressively increased by up to 75 K within 10 crank shaft rotations during cranking. In subsequent experiments with the proposed system, ignition occurred right from the second rotation, whereas there is no combustion occurred in the conventional engine at ambient conditions (28°C). However, at cold condition (10°C), partial combustion was initiated only after 15 recompression rotations and does not produce any positive work output. To mitigate this, the injection schedule was further modified such that the partially burned products were retained in the cylinder without opening the valves and recompressed which autoignited the residual fuel during the subsequent compression stroke. At the end of this compression stroke, the in-cylinder temperature and pressure were high enough and hence the fuel was again injected which resulted in sustained combustion and produced an indicated mean effective pressure (IMEP) of 6 bar that could result in starting even at cold conditions (10°C). Hence, it was demonstrated that the proposed methodology with modified valve timing and injection scheduling has the potential to start the engine at low temperatures particularly with low compression ratios.
Stable headway prediction of vehicle platoon based on the 5-degree-of-freedom vehicle model
Authors: Shi Shuming , Li Ling , Mu Yu , Chen Guanghui
Published: July 2018

Vehicular ad hoc network and cooperative adaptive cruise control system make vehicle platooning with small headway feasible. In the study of the autonomous vehicle platoon system under the vehicular ad hoc network condition, the linear vehicle model is usually used to analyze the minimum space-gap, safety space-gap, and so on. However, the stability of nonlinear vehicle system shows that there are limitations when using the linearized vehicle model to analyze vehicle stability. The linear model cannot reflect the influence of the system nonlinear coupling on the vehicle stability. Therefore, in this paper, we use the validated 5-degree-of-freedom (longitudinal velocity, lateral velocity, yaw rate, front wheel rotational velocity, and rear wheel rotational velocity) nonlinear model to analyze the stable intra-platoon spacing of the autonomous vehicle platoon system under the condition of VANET. In order to study the safety intra-platoon spacing of vehicle platoon running in the complex path, a following controller is designed for vehicle platoon running in the corners. The controller adopts the method of vertical and horizontal decentralized control. The longitudinal control is to realize the expected space-gap of vehicles in vehicle platoon, and the lateral control is to achieve the position and orientation following of the preceding vehicle. Based on the stability verification of the following controller, the following control characteristics of vehicle system are analyzed, and the stable headway required for vehicles in vehicle platoon running in the complex path is predicted by the method of simulation experiment.
Ageing simulation of a hydraulic engine mount: A data-informed finite element approach
Authors: Soltani Payam , Pinna Christophe , Wagg David J , Whear Roly
Published: July 2018

Hydraulic engine mounts are key elements in an automotive vehicle suspension system that typically experience a change of their designed function during their working lifetime due to progressive material ageing, primarily from the elastomeric component. Ageing of the engine mount, resulting from severe and continuous mechanical and thermal loads, can have a detrimental impact on the ride and comfort and long-term customer satisfaction. This paper introduces a new practical methodology for simulating the ageing behaviour of engine mounts resulting from the change in properties of their elastomeric main spring component. To achieve this, a set of dynamic mechanical thermal analysis tests were conducted on elastomeric coupons taken from a set of engine mounts with different service and ageing conditions. These experimental results were used to characterise the change in mechanical response of the elastomer and to build up an empirical elastomer ageing model. Then a finite element model of the main spring was developed that used the elastomer ageing model so that the ageing behaviour of the engine mount could be simulated. The resulting ageing model was verified by using experimental results from a second batch of ex-service engine mounts. The results show an increasing trend of the vertical static stiffness of the engine mounts with distance travelled (or age) up to a certain distance (approximately 95,000 km). The trend is then reversed and a softening effect is observed. Moreover, the results reveal that both the maximum stiffness value and the distance travelled at the peak stiffness decrease as the temperature increases.
Maximizing agility envelopes for reaction wheel spacecraft
Authors: Karpenko Mark , King Jeffery T
Published: July 2018

Spacecraft agility is limited by the maximum torque that reaction wheels can provide. Therefore, a reaction wheel array is typically configured to maximize the inscribed sphere of the reaction wheel torque envelope. Agility is then determined by dividing the spherical torque by the maximum principal inertia. This industry standard approach can severely underestimate the true capability of an attitude control system. An agility envelope considers the reaction wheel torque envelope along with the spacecraft inertia tensor. The agility envelope can therefore be used as a means to quantify the conservatism associated with the standard approach in order to improve slew performance of a conventional attitude control system without the need for larger, more costly hardware or new control algorithms. This paper, presents a simple approach for constructing the agility envelope of a reaction wheel attitude control system. The agility envelope is applied to determine design curves for limits on angular acceleration and rate for maneuver design and for finding the reaction wheel skew angles that maximize agility for a given spacecraft configuration. A surprising result is the observation that maximizing the inscribed sphere of the reaction wheel torque envelope does not, in general, optimize agility.
Cardioprotective effects of insulin on carbon monoxide-induced toxicity in male rats
Authors: Tabrizian K , Shahriari Z , Rezaee R , Jahantigh H , Bagheri G , Tsarouhas K , Docea AO , Tsatsakis A , Hashemzaei M
Published: July 2018

Carbon monoxide (CO) poisoning is a significant cause of death especially in developing countries. The current study investigated cardioprotective effects of insulin in CO-poisoned rats. Male rats were exposed to 3000 ppm CO for 1 h. Insulin (100 and 120 U/kg intraperitoneally) was immediately administered after CO exposure and on the next 4 days, on a daily basis (a total of 5 doses). On day 5, animals were euthanized, and the hearts were harvested for Western blotting and histopathological studies. The electrocardiograms (ECG) were recorded postexposure to CO and after the completion of insulin treatment period. Histopathological evaluations showed reduction of myocardial necrosis in insulin-treated animals compared to controls. BAX/BCL2 ratio, as a proapoptotic index, was significantly reduced in treatment groups ( p < 0.01). The ECG findings showed no differences among groups; also, compared to control animals, myocardial Akt levels were not markedly affected by insulin. The current study showed that insulin significantly reduces myocardial necrotic and apoptotic indices in CO-poisoned rats.
Cardiovascular reflex tests in patients with systemic lupus erythematosus: clinical performance and utility
Authors: Matusik P S , Matusik P T , Stein P K
Published: July 2018

Background

This review summarizes current knowledge about cardiovascular reflex tests (CVRTs) and other selected autonomic nervous system (ANS) assessment tests in systemic lupus erythematosus (SLE) patients and assesses their clinical utility in this group of patients.

Methods

The PubMed database was searched for terms associated with CVRTs and SLE. Only papers available in full text and published in English were considered. Ultimately, 13 were selected and analyzed.

Results

In most of the studies CVRTs results were reported more likely to be abnormal in patients with SLE when compared with controls. The reported prevalence of ANS dysfunction in SLE, diagnosed using CVRTs, ranged from 23.5% to 82.7% of patients, likely because of different definitions of ANS dysfunction, variability in methods of performing CVRTs, and potential confounding factors. In general CVRTs results did not correlate with SLE activity or disease duration, but some CVRTs results correlated with some peptides associated with ANS function, including neuropeptide Y and vasoactive intestinal peptide.

Conclusion

Patients with SLE generally have abnormal or borderline results of CVRTs, which indicate prevalent abnormalities of the ANS in SLE. Performance of CVRTs requires good standardization of test conditions and familiarity with the proper administration and interpretation of these tests.