bluuebunny/crossref_metadata_2025 huggingface dataset:
Flutter Control of a Two-dimensional Airfoil based on Adaptive Dynamic Programming
Authors: Jia Su , Sun Jian Qiao , Ding Qian
Published: September 2019

The severe aeroelastic vibrations can lead to structural damage and threaten the flight safety. It is an important topic to develop active controllers for aeroelastic stabilization and flutter suppression. The traditional control methods need the clearly established mathematic model, whereas establishing an accurate airfoil model with structural and aerodynamic nonlinearities is a difficult task. So a novel data-driven optimal design scheme, adaptive dynamic programming (ADP), is proposed in this paper for a nonlinear airfoil system with one trailing-edge control surface. The proposed ADP algorithm iteratively updates the control policy by using the state and input data without knowing the system dynamical model. Calculation shows that the control policy is convergent after several iterations. Finally, the superiority and feasibility of the control method are verified by simulation.
Experimental investigation of harvesting stochastic vibration energy by a piezoelectric inverted beam with pendulum
Authors: Pan J N , Qin W Y
Published: September 2019

We proposed a harvester composed of inverted piezoelectric beam and a pendulum to enhance the efficiency of vibration-based energy harvesting. Corresponding experiments were performed for validation. The amplitude-frequency response obtained in the vicinity of second natural frequency shows the feature of soften-spring type. The region of multiple solutions originated from nonlinearity could be extended when the excitation is increased to a high level. The experiment under stochastic excitation was carried out, and the corresponding responses were obtained. The absence of low frequency component in stochastic excitation was designed in excitation to show the first natural frequency component in response comes from the coupling between modes. The results verify the energy transformation phenomenon between the first two modes.
Dynamics analysis of multi-field coupled piezoelectric energy harvester under random excitation
Authors: Zhang Xuhui , Zuo Meng , Tan Houzhi , Wu Zhonghua , Lai Zhengpeng , Fan Hongwei
Published: September 2019

Automaatic fully mechanized mining face requires highly equipment condition monitoring. Complex environment of coalmine means the difficulty of wiring and power supply of wired monitoring. The multi-field coupled piezoelectric energy harvester (MPEH) could power wireless monitoring nodes by capture vibration energy from mining equipment. This paper makes a complete investigation of the distance effect of magnet, noise spectrum density and damping on the dynamic response characteristics of the MPEH under random excitation. Taking white Gaussian noise as input excitation, a dynamic model of the MPEH with random excitation in multiple fields is established. The probability density function of dynamic response under different system parameters is obtained by FPK equation, and the stationary mean square value and power spectral density function of system response are given by the ignored high order cumulant truncation method. In order to verify the accuracy of analytical results, the Monte Carlo numerical analysis is presented. Results show that the decrease of the magnetic distance will cause the moving of peak power spectrum frequency to low frequency. Reducing system damping ratio, narrowing magnetic distance or increasing excitation spectral density can enhance the probability of large period vibration and increase the average power of the system.
Nonlinear Dynamics and Performance Enhancement of Multi-stable Wideband Energy Harvesting: Theoretical Analysis
Authors: Wang C , Yang X , Lai S K
Published: September 2019

A new multi-stable wideband harvester is proposed to increase the power density of energy harvesting under wide-bandwidth and low-frequency operations. This harvester can possess with an arbitrary multi-stable state by combining the nonlinearities of stopper-engaged cantilevers and magnetic forces. The harvesting efficiency can be enhanced by interwell oscillations and the global amplitude of the harvester is restricted by the cantilever-stopper engagement. An electromechanical coupling model of the proposed harvester is established to describe its dynamic characteristics. To explore the influence of potential well configurations on a multi-stable energy harvesting, the proposed harvester with four typical potential well configurations is considered while its equivalent nonlinear restoring force can be experimentally identified. The dynamic characteristics of these four configurations at different levels of a harmonic excitation will be explored by both numerical and experimental methods. It is expected that a multiple-well potential with non-uniform depths and shallower outer wells is much more suitable for the proposed system when the external excitation exceeds a critical intensity.
Establishment of rubber thermo-viscoelastic constitutive model and analysis of temperature field
Authors: Chu Hongyan , Hong Yingjie , Chen Qi , Wang Rui
Published: September 2019

Rubber has strong nonlinear viscoelastic behavior. Under the periodically changing external forces, it show deformation hysteresis, mechanical loss and heat generation. In this work, a pair of extruding and rotating steel-rubber rollers was researched. Stress relaxation data at different temperatures were obtained through dynamic thermomechanical analysis experiments. A thermo-viscoelastic rubber constitutive model with temperature factor was obtained by combining the generalized Maxwell model where parameters of rubber viscoelastic were fitted with Prony series. Then, the temperature experiment of structure was conducted on the experimental platform. Based on thermo-viscoelastic constitutive model, simulation and analysis of temperature distribution of steel-rubber roller was obtained. The results of experimental data were consistent with simulation results. Further, the rubber constitutive models of pure elasticity, the superposition of elasticity and viscoelasticity with non-temperature factors, the superposition of elasticity and viscoelasticity with temperature factors were simulated respectively. The results show that the third model was more consistent with the actual experimental results, which verifies the accuracy of constitutive model building by this work. Through numerical comparison and analysis, it was proved that viscoelastic hysteretic heat generation is an indispensable source of heat generation in rubber structure movement.
Atomistic simulation of the nanoindentation behavior of graphene/Al multilayered nanocomposites
Authors: Zhu Jia-Qi , Liu Xia , Yang Qing-Sheng
Published: September 2019

In this paper, the mechanical behaviour of graphene/aluminum multilayered nanocomposites (GAMC) was studied by conducting the nanoindentation simulations using molecular dynamics (MD) method. The reinforcement effect of graphene on aluminum was investigated by two different cases: the graphene layers are considered as the reinforcement and the coating materials respectively. The microscopic deformation mechanism is investigated through the study of a hemispherical diamond indenter indenting against the monocrystalline Al and GAMC. For the graphene-coated Al composite (GCA), it is found that graphene coating layers have an effect on the characteristics of dislocation slip in Al matrix and improve the load carrying capacity of the GCA significantly. In addition, graphene-reinforced Al composite (GRA) with different spacing-distance of the graphene layers was investigated. It is concluded that the GRA shows an increasing nanoindentation properties with reducing the thickness of Al layers. Although the present research is based on monocrystalline aluminum, the deformation mechanism here can be applied to other face-centered-cubic (FCC) monocrystalline metals structures.
Anti-buckling design of cylindrical shells by local surface nanocrystallization
Authors: Xu X S , Zhao Z , Lim C W , Wang W , Lian Z B , Zhou Z H
Published: September 2019

A novel surface modification method, namely the surface nanocrystallization technology, is introduced to enhance the anti–buckling performance of the metal cylindrical shells under axial impact loading. The effects of local nanocrystallization layouts are explored by evaluating the critical buckling loads of four local nanocrystallization layouts including the local circumferential stripes (LCS), local axial stripes (LAS), spaced latticed blocks (SLB) and oblique latticed blocks (OLB). Numercial results show that, compared to the untreated cylindrical shells, the critical buckling loads of the local nanocrystallized ones are significantly improved by the local nanocrystallization treatment. The critical buckling loads for the LAS design is improved by 80%. It is concluded that the local nanocrystallization treatment is a very promising method to design and manufacture the metal cylindrical shells with high anti-buckling performance.
Effect of interference-fit percentage and preload on the mechanical behaviour of single-shear lap composite joint
Authors: Zou Peng , Cheng Hui
Published: September 2019

The mechanical behaviour of composite interference-fit structure is affected by both interference-fit percentage and bolt preload. These two factors combine and interact with each other, leading to a complex joint behaviour. In this paper, the effect of interference-fit percentage and bolt preload on load and damage of single-lap bolted joint is studied from both experiment and finite-element model (FEM). Firstly, an interference-fit preload applying experiment was made. Preloads on both nut and bolt head were measured for different percentages and torques, and the torque coefficient was calibrated. A scanning electron microscope (SEM) analysis on the experimental joint was also conducted to research damages around the hole. Then, the relationship between torque and multi-layer preloads and a composite preload FEM based on progressive damage mechanism were built. The multi-layer preloads were obtained and compared with the experimental measured ones, which verified the reliability of the FEM. In addition, the damage mechanism of different percentages and torques were also analysed and discussed with the simulation results.
Modeling of nonlinear dynamic characteristics and experimental study of piezoelectric energy harvesters with a panel type structure
Authors: Jia Jinda , Shan Xiaobiao , Liu Yingxiang , Xie Tao
Published: September 2019

Panel flutter vibration is a typical aeroelastic phenomenon taking place in flying aircrafts as they move at high speed. The vibration has been a hot academic research aspect. The present paper focuses on converting this aerodynamic mechanical vibration into useful electricity by using piezoelectric patches. A mathematical Euler-Bernoulli distributed model of the piezoelectric energy harvesting system is established to investigate nonlinear dynamical behaviour of a piezoelectric cantilever plate. The dynamical responding ability of energy harvesting is numerically calculated. Influences of the length and the thickness of piezoelectric layer, the external resistance and wind velocity on the output performance are emphatically explored. A series of prototypes of piezoelectric energy harvesters with different physical dimensions were designed and manufactured. Wind tunnel experiments were setup and carried out at different wind velocities. The experimental results show that the harvesting power gets enhanced as increasing the wind velocity. The maximum power could be obtained at condition of a reasonable piezoelectric length and width. Maximum power is 2.0 mW at wind speed of 11.0 m/s. This work provides a strong theoretical and experimental basis for the study of aerodynamic energy harvesting from panel aircrafts.
Design and simulation of a novel ancient Chinese bow-type piezoelectric actuator
Authors: Cao Limin , Ma Chicheng , Guo Zonghe , Ma Juncheng
Published: September 2019

Piezoelectric materials are increasingly researched and used because of their ability to convert electrical energy and mechanical energy. Piezoelectric patches are usually applied with other structures to form piezoelectric actuators to expand the capability and use of piezoelectric patches. In this paper, a new piezoelectric actuator based on the ancient Chinese arch structure is proposed. The piezoelectric actuator is mainly composed of a bow device and several piezoelectric plates. Firstly, the electromechanical coupling model of the cantilever beam structure is established based on the finite element method. The action characteristics of the bow-type piezoelectric actuator are studied. Then static analysis of the cantilever beam with the bow-type piezoelectric actuator is applied. The effect of the bow-type piezoelectric actuator on the cantilever beam under different parameters is analysed and compared, including actuation voltages, locations and physical dimensions of the bow-type structure. Especially, the thickness of the device and the span of the bow device are optimized to better capability. The simulation results show that the thickness and the span of the bow-type device in the bow-type piezoelectric actuator affect the action of the piezoelectric actuator on the cantilever beam remarkably. Additionally, the bow-type piezoelectric actuator is easy to install, simple to manufacture, and can be reused. The research in this paper will provide a reference for the active control or energy harvesting of structural vibration.
Modal analysis of the coupled vibration in an aero-turbine compressor blisk considering both aerodynamic and centrifugal load
Authors: Wang H B , Zhang W , Yao M H , Zhang M M
Published: September 2019

To lighten the aircraft engine and improve its propulsion efficiency, many aero engines adopt the blisk structure comprising both the rotor disk and blades. Since the disk becomes thinner, the stiffness of the structure decreased apparently, which causes the occurrence of large amplitude vibration in the blisk. This passage utilizes the finite element analysis (FEA) and computational fluid dynamics (CFD) simulation software to investigate the coupled vibration characteristics between the blades and the disk of the blisk with realistic geometric data, in which the aerodynamic load and centrifugal load are considered. At first, the CFD and finite element models of an aero-turbine compressor blisk are built. Then the pressure load data under some critical rotating speeds from CFD simulation are communicated to FEA software by data interpolating method, and the simulation of modal characteristics of the blisk is conducted in FEA. At last, the natural modal characteristics of the blisk structure are obtained, including the resonance speed Campbell diagram, the natural frequencies and corresponding mode shapes. According to the Campbell diagram, it indicates that the most critical mode is the fourth order mode. It is found that the mode shape of the fourth order in the blisk is the coupling of the disk torsional and blades first bending vibration. It is easy to lead to vibration failure when large amplitude vibration of the fourth mode occurs in the blisk. Also, it could also conclude that the modal characteristics of the coupled vibration in the rotating blisk are very sensitive to the disk stiffness. These results provide basic data for the further research in nonlinear vibration and structure optimization of the blisk, and also a simulating method to investigate coupled vibration between the blades and the disk of the blisk considering both aerodynamic and centrifugal load.
Multi-objective optimal sliding mode control design of active suspension system with MOPSO algorithm
Authors: Gao Kunming , Guo Zonghe , Qin Zhichang , Li Ruixian , Zhang Yuchen
Published: September 2019

In order to improve the ride comfort and driving stability of the vehicle, a design method of sliding mode controller based on multi-objective particle swarm optimization algorithm is proposed for the vehicle active suspension. Based on the model of 1/4 vehicle active suspension system, the sliding mode controller is designed by using sliding mode control method. The stability of the sliding mode surface is verified by using Lyapunov stability theory. The stability conditions of the sliding mode surface are obtained by combining Hurwitz stability criterion. The particle swarm optimization algorithm is used to optimize the multi-objective optimization of the active suspension and the numerical simulation is carried out. The results show that after multi-objective parameter optimization, the ride comfort and driving stability of the vehicle are significantly improved, which provides a theoretical basis for the research of the vehicle active suspension system.
Bifurcation and Chaos of Rotating Inextensional Ring
Authors: Wang Ligang , Wang Jiaoyang , Asokanthan S F
Published: September 2019

In this paper, the nonlinear dynamics of the inextensional ring structure is investigated. Based on the elasticity theory and the assumption of the inextension of ring, a dynamical model of the ring is established considering the elastic support, the external load and the damping. Then, according to the Galerkin method, the nonlinear mode functions of inextensional ring are used to obtain the order differential equations of ring. Finally, the numerical simulation is carried out and the nonlinear behavior, such as double-period bifurcation, quasi-periodic motion and chaos, is discussed. And the effect of the disturbance of the rotating velocity on the nonlinear behavior of ring is investigated.
Quantitative Analysis of Twelve Active Components Combined With Chromatographic Fingerprint for Comprehensive Evaluation of Qinma Prescription by Ultra-Performance Liquid Chromatography Coupled With Diode Array Detection
Authors: Zhang Yi , Ding Yue , Zhang Tong , Jiang Xiaoyi , Yi Yaxiong , Zhang Lijuan , Chen Yi , Li Ting , Kang Ping , Tian Juanjuan
Published: September 2019

A combination method of ultra-performance liquid chromatography (UPLC) coupled with diode array detection has been developed for quality evaluation of Qinma prescription (QMP), based on chromatographic fingerprint technology with the similarity analysis (SA) and the quantitative analysis of 12 components by hierarchical cluster analysis (HCA). The established method has been validated by linearity, precision, repeatability, stability and recovery tests. The UPLC fingerprints with 17 common peaks of 5 QMP samples prepared by different extraction methods including water decoction extraction, water extraction-ethanol precipitation method, ethanol reflux extraction, ethanol extraction-water precipitation method and methanol ultrasonic extraction were obtained, and the SA results indicated that similarity index was greatly influenced by the large peak. The similarity index ranged from 0.816 to 0.999 basing on 17 peaks, which has been decreased to 0.683–0.999 basing on 16 peaks without the large peak of baicalin (BA). The results of simultaneous quantification of 12 components in these 5 QMP samples proved that BA, gallic acid (GA), wogonoside (WOG) and gentiopicroside (GEN) were the major ingredients in QMP with high contents >1.44 (mg/g), indicating that ethanol reflux was the most effective extraction method. Integrating fingerprint analysis, simultaneous determination and HCA, the established method is rapid, sensitive, accurate and readily applicable. All the results indicated that the combination method can control the quality of QMP and its related traditional Chinese medicinal compounds more comprehensively and scientifically.
Thioredoxin-1 maintains mitochondrial function via mechanistic target of rapamycin signalling in the heart
Authors: Oka Shin-Ichi , Chin Adave , Park Ji Yeon , Ikeda Shohei , Mizushima Wataru , Ralda Guersom , Zhai Peiyong , Tong Mingming , Byun Jaemin , Tang Fan , Einaga Yudai , Huang Chun-Yang , Kashihara Toshihide , Zhao Mengyuan , Nah Jihoon , Tian Bin , Hirabayashi Yoko , Yodoi Junji , Sadoshima Junichi
Published: September 2019

Aims

Thioredoxin 1 (Trx1) is an evolutionarily conserved oxidoreductase that cleaves disulphide bonds in oxidized substrate proteins such as mechanistic target of rapamycin (mTOR) and maintains nuclear-encoded mitochondrial gene expression. The cardioprotective effect of Trx1 has been demonstrated via cardiac-specific overexpression of Trx1 and dominant negative Trx1. However, the pathophysiological role of endogenous Trx1 has not been defined with a loss-of-function model. To address this, we have generated cardiac-specific Trx1 knockout (Trx1cKO) mice.

Methods and results

Trx1cKO mice were viable but died with a median survival age of 25.5 days. They developed heart failure, evidenced by contractile dysfunction, hypertrophy, and increased fibrosis and apoptotic cell death. Multiple markers consistently indicated increased oxidative stress and RNA-sequencing revealed downregulation of genes involved in energy production in Trx1cKO mice. Mitochondrial morphological abnormality was evident in these mice. Although heterozygous Trx1cKO mice did not show any significant baseline phenotype, pressure-overload-induced cardiac dysfunction, and downregulation of metabolic genes were exacerbated in these mice. mTOR was more oxidized and phosphorylation of mTOR substrates such as S6K and 4EBP1 was impaired in Trx1cKO mice. In cultured cardiomyocytes, Trx1 knockdown inhibited mitochondrial respiration and metabolic gene promoter activity, suggesting that Trx1 maintains mitochondrial function in a cell autonomous manner. Importantly, mTOR-C1483F, an oxidation-resistant mutation, prevented Trx1 knockdown-induced mTOR oxidation and inhibition and attenuated suppression of metabolic gene promoter activity.

Conclusion

Endogenous Trx1 is essential for maintaining cardiac function and metabolism, partly through mTOR regulation via Cys1483.
Successful MitraClip for severe rheumatic mitral regurgitation: a case report
Authors: Wong Ningyan , Tan Peilin Cheryl Marise , Ding Zee Pin , Yeo Khung Keong
Published: September 2019

Background

Anatomical exclusion criteria for the MitraClip procedure have included rheumatic heart disease (RHD) involving the mitral valve. This was primarily because RHD is typically associated with mitral stenosis (MS).

Case summary

We report the case of an 85-year-old male who had recurrent heart failure admissions from severe rheumatic mitral regurgitation (MR). This was successfully treated with the MitraClip system.

Discussion

Our case demonstrated the possibility of rheumatic MR being treated by the MitraClip system in appropriately selected patients. Careful examination of the mechanism of MR to determine suitability for MitraClip must be done as well as exclusion of significant MS.
Development and Field Testing of a Long-Term Care Decision Aid Website for Older Adults: Engaging Patients and Caregivers in User-Centered Design
Authors: Hoffman Aubri S , Bateman Daniel R , Ganoe Craig , Punjasthitkul Sukdith , Das Amar K , Hoffman Derek B , Housten Ashley J , Peirce Hillary A , Dreyer Larissa , Tang Chen , Bennett Alina , Bartels Stephen J
Published: September 2019

Background and Objectives

Decisions about long-term care and financing can be difficult to comprehend, consider, and communicate. In a previous needs assessment, families in rural areas requested a patient-facing website; however, questions arose about the acceptability of an online tool for older adults. This study engaged older adults and family caregivers in (a) designing and refining an interactive, tailored decision aid website, and (b) field testing its utility, feasibility, and acceptability.

Research Design and Methods

Based on formative work, the research team engaged families in designing and iteratively revising paper drafts, then programmed a tailored website. The field test used the ThinkAloud approach and pre-/postquestionnaires to assess participants’ knowledge, decisional conflict, usage, and acceptability ratings.

Results

Forty-five older adults, family members, and stakeholders codesigned and tested the decision aid, yielding four decision-making steps: Get the Facts, What Matters Most, Consider Your Resources, and Make an Action Plan. User-based design and iterative storyboarding enhanced the content, personal decision-making activities, and user-generated resources. Field-testing participants scored 83.3% correct on knowledge items and reported moderate/low decisional conflict. All (100%) were able to use the website, spent an average of 26.3 min, and provided an average 87.5% acceptability rating.

Discussion and Implications

A decision aid website can educate and support older adults and their family members in beginning a long-term care plan. Codesign and in-depth interviews improved usability, and lessons learned may guide the development of other aging decision aid websites.
Nanotechnology in the Treatment of Inflammatory Bowel Disease
Authors: Giron Fanny , Pastó Anna , Tasciotti Ennio , Abraham Bincy P
Published: September 2019

Nanotechnology is an emerging field where nanometer particles can be used to deliver medications directly to the area of inflammation thus avoiding drug-associated systemic side effects. Here we review conventional and unconventional therapies applied in the treatment of IBD underlying how the use of nanoparticles can improve their safety and efficacy.
Onset of Ulcerative Colitis in a Patient with Nonalcoholic Fatty Liver Disease (NAFLD): Dramatic Effect of Plant-based Diet for NAFLD
Authors: Chiba Mitsuro , Nakane Kunio , Abe Hitoshi , Komatsu Masafumi , Tozawa Haruhiko
Published: September 2019

Nonalcoholic fatty liver disease (NAFLD) develops in ulcerative colitis (UC) and Crohn’s disease. However, there is scarce reporting on the onset of UC in patients with NAFLD.

A 44-year-old man was diagnosed with UC and referred to us in 2019. His height was 166.0 cm, and body weight was 86.3 kg. The waist circumference was 93.7 cm (normal range <85) and triglyceride was 751 mg/dL. These findings, in addition to hypertension, resulted in a diagnosis of metabolic syndrome. HbA1c was normal. Ultrasonography disclosed severe fatty liver. Nonalcoholic fatty liver disease was diagnosed.

He underwent 12 days of educational hospitalization for UC. A lacto-ovo-semi-vegetarian diet (1400 kcal/day), a kind of plant-based diet (PBD), was provided. He lost 4 kg, which was 4.6% of his base body weight. Triglyceride and total cholesterol decreased to the normal ranges. Transaminases and γ-glutamyl transpeptidase also decreased. His body weight decreased further after discharge. Follow-up ultrasonography indicated an improvement in hepatic enlargement. The shear wave velocity decreased from 1.11 to 0.88 m/s. His soft stool became normal stool by 2 months after discharge.

Records of his health checkups revealed the presence of metabolic syndrome and abnormal liver function tests already in 2015. Thus, it was concluded that UC developed in a patient with NAFLD in this case. Plant-based diet has already been shown to be effective in inflammatory bowel disease (IBD). In the present case, NAFLD parameters were dramatically improved by PBD. Whether the improvement was due to weight loss per se or due to weight loss with PBD is to be clarified.
Laryngeal Carcinoma in Patients With Inflammatory Bowel Disease: Clinical Outcomes and Risk Factors
Authors: van de Ven Steffi E M , Derikx Lauranne A A P , Nagtegaal Iris D , van Herpen Carla M , Takes Robert P , Melchers Willem J G , Pierik Marieke , van den Heuvel Tim , Verhoeven Rob H A , Hoentjen Frank , Nissen L H C
Published: September 2019

Background

Inflammatory bowel disease (IBD) patients are at increased risk for developing extra-intestinal malignancies, mainly due to immunosuppressive medication. The risk of developing head and neck cancer in immunosuppressed transplant patients is increased. The relation between IBD patients and laryngeal cancer (LC) remains unclear. We aimed (1) to identify risk factors in IBD patients for LC development and (2) to compare clinical characteristics, outcome, and survival of LC in IBD patients with the general population.

Methods

All IBD patients with LC (1993–2011) were retrospectively identified using the Dutch Pathology Database. We performed 2 case–control studies: (1) to identify risk factors, we compared patients with IBD and LC (cases) with the general IBD population; (2) to analyze LC survival, we compared cases with controls from the general LC population.

Results

We included 55 cases, 1800 IBD controls, and 2018 LC controls. Cases were more frequently male compared with IBD controls (P < 0.001). For ulcerative colitis (UC), cases were older at IBD diagnosis (P < 0.001). Crohn’s disease (CD) cases were more frequently tobacco users (P < 0.001) and more often had stricturing (P = 0.006) and penetrating (P = 0.008) disease. We found no survival difference. Immunosuppressive medication had no impact on survival.

Conclusions

Male sex was a risk factor for LC in IBD patients. Older age at IBD diagnosis was a risk factor for UC to develop LC. Tobacco use and stricturing and penetrating disease were risk factors for LC development in CD patients. Inflammatory bowel disease was not associated with impaired survival of LC. Immunosuppressive medication had no influence on survival.
Effects of maternal supplementation with an injectable trace mineral on subsequent calf performance and inflammatory response1
Authors: Stokes Rebecca S , Volk Mareah J , Ireland Frank , Shike Daniel W
Published: September 2019

Newly weaned, commercial Angus steers [body weight (BW) = 204 ± 19 kg; n = 24; 12 steers from dams administered an injectable trace mineral (MM; Mulimin90) and 12 steers from control (CON) dams] were utilized to determine the effects of maternal supplementation with an injectable trace mineral on the inflammatory response of subsequent steers subjected to a lipopolysaccharide (LPS) challenge at the initiation of a 42-d receiving period. On day −2 steers were weaned, and the following day, shipped 354 km to the Beef Cattle and Sheep Field Laboratory in Urbana, IL. On day 0, steers were administered an intravenous LPS challenge. Body temperature and blood samples were collected from steers prior to LPS administration (0 h) and again at 0.5, 1, 2, 3, 4, 5, and 6 h. Blood samples were analyzed for trace mineral and cortisol at 0 and 2 h and glucose, insulin, LPS-binding protein (LBP), interleukin-1β (IL-1β), interleukin-6 (IL-6), haptoglobin, ceruloplasmin, and fibrinogen at 0, 0.5, 1, 2, 3, 4, 5, and 6 h. Calf BW was collected at trial initiation and subsequently every 14 d. Dry matter intake was collected daily and average daily gain (ADG) and feed efficiency were assessed. Initial plasma Zn tended (P = 0.06) to be greater for MM steers. However, there was no difference (P ≥ 0.31) in trace mineral status or serum cortisol at any other time. Total area under the curve (TAUC) for body temperature was lesser (P > 0.01) for MM steers. Basal LBP concentrations and TAUC for LBP tended (P ≤ 0.10) to be greater for MM steers. Peak concentration of IL-6 tended (P = 0.09) to be reached earlier for CON steers. However, there was no difference (P ≥ 0.11) in glucose, insulin, IL-6, ceruloplasmin, haptoglobin, and fibrinogen concentrations between treatments. Calf performance and feed efficiency did not differ (P ≥ 0.17) between treatments except ADG from day 28 to 42, which was greater (P = 0.03) for CON steers. Maternal supplementation with an injectable trace mineral tended to improve steer plasma Zn status at 0 h and tended to increase basal concentrations of LBP and overall LBP production when steers were administered an LPS challenge. Additionally, MM steers exhibited a more favorable change in body temperature following LPS administration. However, injectable trace mineral supplementation of dams during gestation had minimal to no effect on cytokine and acute-phase protein concentrations, as well as overall calf performance and efficiency during a 42-d receiving period.
Pathways to Implementation: Evidence on How Participation in Environmental Governance Impacts on Environmental Outcomes
Authors: Jager Nicolas W , Newig Jens , Challies Edward , Kochskämper Elisa
Published: September 2019

There is much enthusiasm among scholars and public administrators for participatory and collaborative modes of governance as a means to tackle contemporary environmental problems. Participatory and collaborative approaches are expected to both enhance the environmental standard of the outputs of decision-making processes and improve the implementation of these outputs. In this article, we draw on a database of 305 coded published cases of public environmental decision-making to identify key pathways via which participation fosters effective environmental governance. We develop a conceptual model of the hypothesized relationship between participation, environmental outputs, and implementation, mediated by intermediate (social) outcomes such as social learning or trust building. Testing these assumptions through structural equation modeling and exploratory factor analysis, we find a generally positive effect of participation on the environmental standard of governance outputs, in particular where communication intensity is high and where participants are delegated decision-making power. Moreover, we identify two latent variables—convergence of stakeholder perspectives and stakeholder capacity building—to mediate this relationship. Our findings point to a need for treating complex and multifaceted phenomena such as participation in a nuanced manner, and to pay attention to how particular mechanisms work to foster a range of social outcomes and to secure more environmentally effective outputs and their implementation.
Spontaneous Pneumopericardium in a U.S. Marine: Do not Lose Heart
Authors: Sherrier David , Lizardo Radhames E
Published: September 2019

We report an unusual case of extensive subcutaneous emphysema, pneumomediastinum, and pneumopericardium identified in an otherwise healthy U.S. Marine who was enrolled in the Marine Corps School of Infantry. His training regimen included prolonged periods of yelling and elevation changes during sustained hiking through hilly terrain. The patient presented to the Fast Track with normal vital signs but complained of dyspnea, cough, and subjective fevers. Although he lacked a history of trauma, he was found to have pneumopericardium, pneumomediastinum, and subcutaneous emphysema without pneumothorax. He was admitted to the general surgery service for observation and was ultimately released back to his unit after 24 hours. To our knowledge, pneumopericardium has never been attributed to persistent yelling in the setting of a lower respiratory tract infection and should be considered in the differential of atraumatic chest symptomatology in otherwise healthy military service members.
Driving massive molecular gas flows in central cluster galaxies with AGN feedback
Authors: Russell H R , McNamara B R , Fabian A C , Nulsen P E J , Combes F , Edge A C , Madar M , Olivares V , Salomé P , Vantyghem A N
Published: September 2019

We present an analysis of new and archival ALMA observations of molecular gas in 12 central cluster galaxies. We examine emerging trends in molecular filament morphology and gas velocities to understand their origins. Molecular gas masses in these systems span $10^9 {--}10^{11} {\rm \, M_{\odot }}$, far more than most gas-rich galaxies. ALMA images reveal a distribution of morphologies from filamentary to disc-dominated structures. Circumnuclear discs on kiloparsec scales appear rare. In most systems, half to nearly all of the molecular gas lies in filamentary structures with masses of a few $\times 10^{8{\text{--}}10}{\rm \, M_{\odot }}$ that extend radially several to several tens of kpc. In nearly all cases the molecular gas velocities lie far below stellar velocity dispersions, indicating youth, transience, or both. Filament bulk velocities lie far below the galaxy’s escape and free-fall speeds indicating they are bound and being decelerated. Most extended molecular filaments surround or lie beneath radio bubbles inflated by the central active galactic nuclei (AGNs). Smooth velocity gradients found along the filaments are consistent with gas flowing along streamlines surrounding these bubbles. Evidence suggests most of the molecular clouds formed from low entropy X-ray gas that became thermally unstable and cooled when lifted by the buoyant bubbles. Uplifted gas will stall and fall back to the galaxy in a circulating flow. The distribution in morphologies from filament to disc-dominated sources therefore implies slowly evolving molecular structures driven by the episodic activity of the AGNs.
Identification of asteroids using the Virtual Observatory: the WFCAM Transit Survey
Authors: Cortés-Contreras M , Jiménez-Esteban F M , Mahlke M , Solano E , Ďurech J , Barceló Forteza S , Rodrigo C , Velasco A , Carry B
Published: September 2019

The nature and physical properties of asteroids, in particular those orbiting in the near-Earth space, are of scientific interest and practical importance. Exoplanet surveys can be excellent resources to detect asteroids, both already known and new objects. This is due to their similar observing requirements: large fields of view, long sequences, and short cadence. If the targeted fields are not located far from the ecliptic, many asteroids will cross the field of view occasionally. We present two complementary methodologies to identify asteroids serendipitously observed in large-area astronomical surveys. One methodology focuses on detecting already known asteroids using the Virtual Observatory tool SkyBoT, which predicts their positions and motions in the sky at a specific epoch. The other methodology applies the ssos pipeline, which is able to identify known and new asteroids based on their apparent motion. The application of these methods to the 6.4 deg2 of the sky covered by the Wide-Field CAMera Transit Survey in the J-band is described. We identified 15 661 positions of 1821 different asteroids. Of them, 182 are potential new discoveries. A publicly accessible online, Virtual Observatory compliant catalogue was created. We obtained the shapes and periods for five of our asteroids from their light curves built with additional photometry taken from external archives. We demonstrated that our methodologies are robust and reliable approaches to find, at zero cost of observing time, asteroids observed by chance in astronomical surveys. Our future goal is to apply them to other surveys with adequate temporal coverage.
Dissecting Violence. Autopsy, Medical Expertise and Criminal Justice in Early Modern Flanders
Authors: Dekoster Kevin
Published: September 2019

Drawing on a sample of 875 forensic medical reports produced within the early modern County of Flanders, this contribution aims to analyse and explain some developments in the medico-legal discourse of violent crime. While sixteenth-century post-mortem reports essentially deal with assessing the lethality of wounds, later centuries witnessed a more elaborate approach to violent death, in which attempts were made to establish the relationship between a wound and fatality by reconstructing its pathology. In this way, medical expertise contributed to a more nuanced qualification of violent crime, thoroughly influencing judicial decision-making by bringing new attenuating circumstances into play, while adhering to a cautious empiricist epistemology. This cautiousness also constituted one of the weaknesses of the reports, making their content vulnerable to criticism by judicial officials whose primary concern was to resolve homicide cases.
Cortical hyperarousal in NREM sleep normalizes from pre- to post- REM periods in individuals with frequent nightmares
Authors: Blaskovich Borbála , Reichardt Richárd , Gombos Ferenc , Spoormaker Victor I , Simor Péter
Published: September 2019

Study Objectives

Frequent nightmares have a high prevalence and constitute a risk factor for psychiatric conditions, but their pathophysiology is poorly understood. Our aim was to examine sleep architecture and electroencephalographic markers—with a specific focus on state transitions—related to sleep regulation and hyperarousal in participants with frequent nightmares (NM participants) versus healthy controls.

Methods

Healthy controls and NM participants spent two consecutive nights in the sleep laboratory. Second night spectral power during NREM to REM sleep (pre-REM) and REM to NREM (post-REM) transitions as well as during NREM and REM periods were evaluated for 22 NM participants compared to 22 healthy controls with a similar distribution of age, gender, and dream recall frequency.

Results

We found significant differences between the groups in the pre-REM to post-REM changes in low- and high-frequency domains. NM participants experienced a lower amount of slow-wave sleep and showed increased beta and gamma power during NREM and pre-REM periods. No difference was present during REM and post-REM phases. Furthermore, while increased pre-REM high-frequency power seems to be mainly driven by post-traumatic stress disorder (PTSD) symptom intensity, decreased low-frequency activity occurred regardless of PTSD symptom severity.

Conclusion

Our findings indicate that NM participants had increased high-frequency spectral power during NREM and pre-REM periods, as well as relatively reduced slow frequency and increased fast frequency spectral power across pre-and post-REM periods. This combination of reduced sleep-protective activity and increased hyperarousal suggests an imbalance between sleep regulatory and wake-promoting systems in NM participants.
Assessing cancer center researcher and provider perspectives on patient engagement
Authors: Carolan Kelsi , Charlot Marjory , Gawuga Cyrena , Freeman Elmer , Kim Ji Hyang , Sprague Martinez Linda
Published: September 2019

Participatory research approaches can help ensure research is culturally relevant and aligned with stakeholder priorities, but barriers exist between researchers and community stakeholders, particularly in communities of color. We developed a measurement tool for assessing oncology researcher and provider readiness to undertake patient-engaged research, and piloted this measurement tool among oncology researchers and providers at the hospital's cancer care center. A survey was developed by drawing from existing PCORI assessments as well as creating original questions, in an effort to develop an evidence-based survey tailored to this project. A total of 23 researchers and providers responded to the survey. The majority of respondents indicated that they were moderately or very familiar with the concept of patient-centered outcomes research. Most respondents had little to no experience engaging in participatory research and endorsed several barriers to engaging patients in the research process, including lack of experience and time. A mechanism for preparing and supporting researchers and providers is needed if cancer centers are to implement patient-powered research agendas as recommended by PCORI.
Point Mutations in the β-Tubulin of Phytophthora sojae Confer Resistance to Ethaboxam
Authors: Peng Qin , Wang Zhiwen , Fang Yuan , Wang Weizhen , Cheng Xingkai , Liu Xili
Published: September 2019

Ethaboxam is a β-tubulin inhibitor registered for the control of oomycete pathogens. The current study was established to determine the ethaboxam sensitivity of the plant pathogen Phytophthora sojae and investigate the potential for the emergence of fungicide resistance. The effective concentration for 50% inhibition (EC50) of 112 Phytophthora sojae isolates exhibited a unimodal distribution with a mean EC50 for ethaboxam of 0.033 µg/ml. Establishing this baseline sensitivity provided critical data for monitoring changes in ethaboxam-sensitivity in field populations. The potential for fungicide resistance was investigated using adaptation on ethaboxam-amended V8 agar, which resulted in the isolation of 20 resistant mutants. An assessment of the biological characteristics of the mutants including mycelial growth, sporulation, germination rate and pathogenicity indicated that the resistance risk in Phytophthora sojae was low to medium with no cross-resistance between ethaboxam and cymoxanil, metalaxyl, flumorph, and oxathiapiprolin being detected. However, positive cross-resistance was found between ethaboxam and zoxamide for Q8L and I258V but negative cross-resistance for C165Y. Further investigation revealed that the ethaboxam-resistant mutants had point mutations at amino acids Q8L, C165Y, or I258V of their β-tubulin protein sequences. CRISPR/Cas9-mediated transformation experiments confirmed that the Q8L, C165Y, or I258V mutations could confer ethaboxam resistance in Phytophthora sojae and that the C165Y mutation induces high levels of resistance. Taken together, the results of the study provide essential data for monitoring the emergence of resistance and resistance management strategies for ethaboxam, as well as for improving the design of novel β-tubulin inhibitors for future development.
A MAPP Network Case-control Study of Urological Chronic Pelvic Pain Compared With Nonurological Pain Conditions
Authors: Afari Niloofar , Buchwald Dedra , Clauw Daniel , Hong Barry , Hou Xiaoling , Krieger John N. , Mullins Chris , Stephens-Shields Alisa J. , Gasperi Marianna , Williams David A.
Published: September 2019

Objectives:

Limited research suggests commonalities between urological chronic pelvic pain syndromes (UCPPS) and other nonurological chronic overlapping pain conditions (COPCs) including fibromyalgia, chronic fatigue syndrome, and irritable bowel syndrome. The goal of this case-control study was to examine similarities and differences between UCPPS and these other COPCs.

Materials and Methods:

As part of the Multidisciplinary Approach to the Study of Chronic Pelvic Pain Research (MAPP) Network, we examined 1039 individuals with UCPPS (n=424), nonurological COPCs (n=200), and healthy controls (HCs; n=415). Validated standardized measures were used to assess urological symptoms, nonurological pain symptoms, and psychosocial symptoms and traits.

Results:

Participants with UCPPS had more urological symptoms than nonurological COPCs or HCs (P<0.001); nonurological COPC group also had significantly worse urological symptoms than HCs (P<0.001). Participants with nonurological COPCs reported more widespread pain than those with UCPPS (P<0.001), yet both groups had similarly increased symptoms of anxiety, depression, negative affect, perceived stress, neuroticism, and lower levels of extraversion than HCs (P<0.001). Participants with UCPPS with and without COPCs reported more catastrophizing than those with nonurological COPCs (P<0.001).

Discussion:

Findings are consistent with the hypothesis of common underlying biopsychosocial mechanisms and can guide the comprehensive assessment and treatment of these conditions regardless of the primary site of pain or diagnosis. Heightened catastrophizing in UCPPS should be examined to inform psychosocial interventions and improve patient care.