bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of Local Damage to Reinforced Concrete Panels Subjected to Oblique Impact of Rigid and Soft Missiles
Authors: Nishida Akemi , Nagai Minoru , Tsubota Haruji , Li Yinsheng
Published: October 2018

Many empirical formulas have been proposed for evaluating local damage to reinforced concrete (RC) structures caused by impacts of rigid missiles. Most of these formulas have been derived based on impact tests normal to the target structures. Up to now, few impact tests oblique to the target structures have been carried out. This study has been conducted with the purpose of proposing a new formula for evaluating the local damage caused by oblique impacts based on previous experimental and simulation results.

In this paper, the results of simulation analyses for evaluating the local damage to a RC panel subjected to normal and oblique impacts by rigid and soft missiles, by using the simulation method that was validated using the results of previous impact experiments. Based on the results of these simulation analyses, the effects of the rigidity of the missile as well as the impact angle on the local damage to the target structures are clarified.
Numerical Impact Simulation of Aircraft Into Reinforced Concrete Walls With Different Thickness
Authors: Hirosaka Kazuma , Takazawa Hidekazu , Miyazaki Katsumasa , Tohyama Norihide , Nouji Hiroyuki , Matsumoto Naomi
Published: October 2018

Aircraft impact analysis is needed for a safety assessment of nuclear power plants. One of the contents which should be analysed for aircraft impact is physical damage of a concrete building and this can be estimated by a numerical simulation. In order to conduct aircraft impact analysis, simulation model which validated by some experimental data needs to be established.

In 1990s, impact test using actual F4 Phantom fighter was conducted at Sandia national laboratory in U.S. and a lot of important experimental data were measured. In this paper, the numerical simulation results for this F4 Phantom impact test are introduced. The relationship between the thickness of the shell of the F4 Phantom simulation model and the deceleration of this model is indicated and the differences of the deceleration between simulation and test results are discussed. In addition, the relationship between fracture strain of the shell of the F4 Phantom simulation model and the destruction mode of this model in simulation is indicated and the differences between the destruction mode of the F4 Phantom between simulation and test results are discussed.

In order to evaluate the physical damage area after the aircraft impact, it is necessary to estimate the aircraft velocity after it perforates the outer concrete wall and to calculate the decrease of the kinematic energy of the aircraft by this perforation. In this paper, several aircraft impact simulations with different concrete wall thickness are conducted and the reduction in kinematic energies of an aircraft by a perforation is estimated. Using these simulation results, the necessary numbers of concrete walls until the impacting aircraft stops is discussed.
Ultrasonic Velocities Measurement in Compacted Bentonite-Sand Mixtures for Saturation Level Evaluation
Authors: Kimura Shun , Takahashi Hideharu , Hamdani Ari , Aritomi Masanori , Ozaki Susumu , Kikura Hiroshige
Published: October 2018

Compacted bentonite materials are often considered as a buffer material in the geological radioactive waste disposal. This bentonite is expected to fill up the space between the waste and the surrounding ground by swelling. Therefore, understanding the surrounding ground, i.e., groundwater behavior in bentonite, as a buffer material, is essential in order to evaluate the bentonite buffer performance and guarantee long-term safety. The monitoring system of the water saturation level in compacted bentonite is required because water content in buffer material may influence its elastic properties. In this study, the correlation between water content and elasticity in unsaturated compressed bentonite was experimentally evaluated. The evaluation was done by measuring the sound velocity of both longitudinal wave and transverse wave. As a result, it can be confirmed that ultrasonic velocities could evaluate a degree of saturation and bulk modulus of compacted bentonite.
WATCH Loop Development and Commissioning Tests
Authors: Byers W. A. , Wang G.
Published: October 2018

It is essential to understand how crud build-up leads to elevated cladding temperatures and abnormal cladding corrosion for Boiling Water Reactor (BWR) fuel. With a heated rod test loop configuration, the influence of water chemistry on crud build-up and cladding corrosion behavior can be assessed.

A new test loop named the Westinghouse Annular Thermal Crud Hydraulic (WATCH) Loop, has been designed to grow simulated BWR crud under normal BWR operating conditions. WATCH simulates the bottom meter of a BWR core in terms of temperature, flow, steam quality and heat flux. Test results from this loop can be used to benchmark risk assessment tools, which in turn are used to make predictions and minimize or avoid BWR fuel rod failures, consistent with guidelines from the Institute of Nuclear Power Operations (INPO) and the Electric Power Research Institute (EPRI).

In this paper, the Westinghouse Annular Thermal Crud Hydraulic (WATCH) Loop design and development are introduced. The results of a commissioning test and a run producing zinc-rich deposits are also presented.
The International Experimental Thermal Hydraulic Systems Database (TIETHYS): A New NEA Validation Tool
Authors: Rohatgi Upendra , Dyrda James , Soppera Nicolas
Published: October 2018

Nuclear reactor codes require validation with appropriate data representing the plant for specific scenarios. The thermal-hydraulic data is scattered in different locations and in different formats. Some of the data is in danger of being lost. A relational database is being developed to organize the international thermal hydraulic test data for various reactor concepts and different scenarios. At the reactor system level, that data is organized to include separate effect tests and integral effect tests for specific scenarios and corresponding phenomena. The database relies on the phenomena identification sections of expert developed PIRTs. The database will provide a summary of appropriate data, review of facility information, test description, instrumentation, references for the experimental data and some examples of application of the data for validation. The database has expandable platform and will accommodate different types of reactors and thermal-hydraulic tests. The current database platform includes scenarios for PWR, BWR, VVER, and specific benchmarks for CFD modelling data and is to be expanded to include references for molten salt reactors. There are place holders for high temperature gas cooled reactors, CANDU and liquid metal reactors. This relational database is called The International Experimental Thermal Hydraulic Systems database – TIETHYS and currently resides at Nuclear Energy Agency (NEA) of the OECD and is freely open to public access. Going forward the database will be extended to include additional links and data as they become available. The organizations conducting thermal-hydraulic tests are encouraged to submit their test data for inclusion in database for wider exposure and for preservation. https://www.oecd-nea.org/tiethysweb/
Prediction of surface topography due to finite pixel spacing in focused ion beam milling of circular holes and trenches
Authors: Rumyantsev Alexander V. , Borgardt Nikolay I.
Published: October 2018

Successful implementation of focused ion beam technologies in fabrication of practically important structures, including circular holes and trenches requires evaluating the ion dose delivered to the specimen by the beam and subsequently predicting the formed topography. In this article, the analytical expressions for the ion dose are obtained in polar coordinates using Bessel functions. These expressions can be transformed into relatively straightforward formulas useful in many applications. On the basis of the expressions derived, the surface shape of structures under consideration is analytically described if constant sputtering yield conditions are realized throughout the milling process. For practically relevant structure preparation, when the distance between neighboring beam stops is less than approximately two beam diameters, it was established that the mean depth and the peak-to-valley surface roughness can be evaluated by simple formulas. The outcomes of theoretical findings are confirmed by the comparison with the numerically obtained results and experimental data retrieved from the fabricated circular holes.
Electrically tunable low-density superconductivity in a monolayer topological insulator
Authors: Fatemi Valla , Wu Sanfeng , Cao Yuan , Bretheau Landry , Gibson Quinn D. , Watanabe Kenji , Taniguchi Takashi , Cava Robert J. , Jarillo-Herrero Pablo
Published: October 2018

A monolayer of many talents

Superconductors with a topologically nontrivial band structure have been predicted to exhibit exotic properties. However, such materials are few and far between. Now, two groups show that the monolayer of the material tungsten ditelluride (WTe
2
)—already known to be a two-dimensional topological insulator—can also go superconducting. Fatemi
et al.
and Sajadi
et al.
varied the carrier density in the monolayer by applying a gate voltage and observed a transition from a topological to a superconducting phase. The findings may lead to the fabrication of devices in which local gating enables topological and superconducting phases to exist in the same material.

Science
, this issue p.
926
, p.
922
How Bioinformatic Tools Guide Experiments To Resolve the Chaos of Apparently Unlimited Metabolic Variation
Authors: Cole Jeffrey A.
Published: October 2018

Hexuronic acids, oxidation products of common sugars, are widespread in eukaryotic cells. Galacturonic acid is the main carbohydrate component of pectin found in plant cell walls and glucuronic acid is a component of proteoglycans in animals.
Molecular Typing and Macrolide Resistance Analyses of Treponema pallidum in Heterosexuals and Men Who Have Sex with Men in Japan, 2017
Authors: Kanai Mizue , Arima Yuzo , Nishiki Shingo , Shimuta Ken , Itoda Ichiro , Matsui Tamano , Oishi Kazunori , Ohnishi Makoto , Nakayama Shu-ichi
Published: October 2018

In recent years, syphilis notifications have increased dramatically in Japan. We carried out molecular typing and macrolide resistance analyses of
Treponema pallidum
subsp.
Functional Mapping of Regions Involved in the Negative Imprinting of Virion Particle Infectivity and in Target Cell Protection by Interferon-Induced Transmembrane Protein 3 against HIV-1
Authors: Appourchaux Romain , Delpeuch Mathilde , Zhong Li , Burlaud-Gaillard Julien , Tartour Kevin , Savidis George , Brass Abraham , Etienne Lucie , Roingeard Philippe , Cimarelli Andrea
Published: October 2018

IFITM proteins have been associated with the sequestration of incoming virions in endosomes (target cell protection) and with the production of virion particles that incorporate IFITMs and exhibit decreased infectivity (negative imprinting of virion infectivity). How the latter is regulated and whether these two antiviral properties are related remain unknown. By examining the behavior of a large panel of IFITM3 mutants against HIV-1, we determined that IFITM3 mutants are essentially packaged into virions proportionally to their intracellular levels of expression. However, even in the context of an IFITM-susceptible virus, IFITM3 packaging is not sufficient for the antiviral effects. Most mutations were found to concomitantly affect both antiviral properties of IFITM3, but one CTD mutant exhibited a divergent behavior, possibly highlighting a novel regulatory role for this domain. These findings thus advance our comprehension of how this class of broad antiviral restriction factors acts.
Rare recurrence of apical ballooning (takotsubo) syndrome in an elderly man
Authors: Adigun Rosalyn , Morley Samantha , Prasad Abhiram
Published: October 2018

Apical ballooning syndrome (ABS) is an under recognised clinical entity characterised by acute reversible left ventricular systolic dysfunction that mimics acute myocardial infarction in the absence of obstructive coronary artery disease; typically occurring in the setting of profound stress.1 ABS disproportionately affects older women and recurrences are infrequent. We, hereby, describe a rare phenomenon of recurrent ABS in an elderly male patient, 10 years apart, presenting with the same left ventricular morphological appearance following non-cardiac surgeries. The case illustrates the importance of considering ABS in the differential diagnosis of perioperative acute myocardial infarction in older men undergoing major surgery.
Ultrasonic measurement of optic nerve sheath diameter: a non-invasive surrogate approach for dynamic, real-time evaluation of intracranial pressure
Authors: Chen Li-min , Wang Li-juan , Hu Yang , Jiang Xiao-han , Wang Yu-zhi , Xing Ying-qi
Published: October 2018

The current study aimed to identify whether ultrasonographic measurements of optic nerve sheath diameter (ONSD) could dynamically and sensitively evaluate real-time intracranial pressure (ICP). ONSD measurements were performed approximately 5  min prior to and after a lumbar puncture (LP). A total of 84 patients (mean±SD age, 43.5±14.7 years; 41 (49%) men; 18 patients with elevated ICP) were included in the study. The Spearman correlation coefficients between the two observers were 0.779 and 0.703 in the transverse section and 0.751 and 0.788 in the vertical section for the left and right eyes, respectively. The median (IQR) change in ONSD (ΔONSD) and change in ICP (ΔICP) were 0.11 (0.05–0.21) mm and 30 (20–40) mmH2O, respectively, for all participants. With a reduction in cerebrospinal fluid pressure, 80 subjects (95%) showed an immediate drop in ONSD; the median (IQR) decreased from 4.13 (4.02–4.38) mm to 4.02 (3.90–4.23) mm (p<0.001). Significant correlations were found between ONSD and ICP before LPs (r=0.482, p<0.01) and between ΔONSD and ΔICP (r=0.451, p<0.01). Ultrasonic measurement of ONSD can reflect the relative real-time changes in ICP.
Beyond vision loss: the independent impact of diabetic retinopathy on vision-related quality of life in a Chinese Singaporean population
Authors: Fenwick Eva K , Man Ryan E K , Gan Alfred Tau Liang , Kumari Neelam , Wong Charlene , Aravindhan Amudha , Gupta Preeti , Wang Jie Jin , Mitchell Paul , Wong Tien Yin , Cheng Ching-Yu , Lamoureux Ecosse Luc
Published: October 2018

Background/aims

To assess the independent impact of diabetic retinopathy (DR) on three domains of vision-related quality of life (VRQoL) in a Chinese Singapore population.

Methods

The Singapore Chinese Eye Study (n=3353; 2009–2011) was a population-based, prospective, cross-sectional study conducted at the Singapore Eye Research Institute. The study population included 292 adults with diabetes, with and without DR. DR (better eye) was categorised as presence and absence of any DR; severity of DR (no vision-threatening DR (VTDR); severe non-proliferative DR (NPDR); PDR and/or clinically significant macular oedema and VTDR). Our main outcome was VRQoL which was measured using Rasch-calibrated scores from the ‘Reading’, ‘Mobility’ and ‘Emotional’ domains of the Impact of Vision Impairment questionnaire. The relationship between DR and VRQoL was assessed using multiple linear regression models.

Results

Of the 292 individuals (mean age 61.35 ± 9.66 years; 55.8% male), 201 (68.8%), 49 (16.8%), 20 (6.8%), 22 (7.5%) and 27 (9.2%) had no DR, minimal-mild NPDR, moderate-severe NPDR, PDR and VTDR, respectively. Any DR and VTDR were independently associated with 6% and 12% worse Reading scores and 7% and 18% poorer Emotional well-being, respectively, compared with those without DR. These associations persisted after separate adjustment for visual impairment and presenting visual acuity. No significant difference was found in the Mobility domain between persons with and without DR.

Conclusions

We documented that DR, particularly VTDR, was independently associated with restrictions in Reading and Emotional well-being. Understanding factors underlying the detrimental DR-VRQoL relationship may optimise rehabilitation outcomes for individuals with DR.
Protocol for a randomised controlled trial to study cryoprevention of chemotherapy-induced oral mucositis after autologous stem cell transplantation
Authors: Walladbegi Java , Svanberg Anncarin , Gellerstedt Martin
Published: October 2018

Introduction

A majority of patients who receive myeloablative therapy prior to hematopoetic stem cell transplantation develop oral mucositis (OM). This adverse cytotoxic effect manifests as oral mucosal erythema and ulcerations and frequently necessitates high doses of morphine for pain alleviation. OM may also interfere with food intake and result in parenteral nutrition, weight loss and impaired quality of life. To date, there have been a few studies of evidence-based interventions for prevention of OM. Cooling the oral mucosa using ice chips in conjunction with chemotherapy is known to reduce the severity of OM although clinical application is still limited due to several disadvantages. The primary endpoint of this study is therefore to evaluate the efficacy of an innovative intraoral cooling device (Cooral) compared with ice cooling in reducing the degree of OM, in patients with myeloma or lymphoma.

Method and analysis

A total of 180 patients from four different university hospitals in Sweden will be randomised to ice or Cooral in a proportion of 1:1. The degree of OM will be assessed at eight intraoral locations, in accordance with the Oral Mucositis Assessment Scale and WHO scale. Patients will be registered beginning at admission and will continue until discharge or until day +28. The primary variable is analysed in a multiple linear regression model. The significance level used is 5%.

Ethics and dissemination

The study protocol, questionnaire, diaries and letter of invitation to participants have been reviewed by the local ethical board in Göteborg. The trial results will be published in a peer-reviewed journal and disseminated to participants.

Trial registration number

NCT03203733; Pre-results.

Protocol version

Version 4, 2017-06-05
Caesarean section in Palestine using the Robson Ten Group Classification System: a population-based birth cohort study
Authors: Zimmo Mohammed Walid , Laine Katariina , Hassan Sahar , Bottcher Bettina , Fosse Erik , Ali-Masri Hadil , Zimmo Kaled , Sørum Falk Ragnhild , Lieng Marit , Vikanes Åse
Published: October 2018

Objective

To analyse the current situation of caesarean section in Palestine using the Robson Ten Group Classification System (TGCS).

Design

A population-based birth cohort study.

Setting

Obstetrical departments in three governmental hospitals in Gaza.

Participants

All women (18 908) who gave birth between 1 January 2016 and 30 April 2017.

Methods

The contributions of each group to the study population and to the overall rate of caesarean section were calculated, as well as the rate of caesarean section in each TGCS group. Differences in proportions between study hospitals were assessed by χ2 test.

Main outcome measures

The main outcome was the contributions of each group to the overall caesarean section rate.

Results

The overall rate of caesarean section was 22.9% (4337 of 18 908), ranging from 20.6% in hospital 1 to 24.6% in hospital 3. The largest contributors to the overall caesarean section rate were multiparous women with single cephalic full-term pregnancy who had undergone at least one caesarean section (group 5, 42.6%), women with multiple pregnancies (group 8, 11.6%) and those with single cephalic preterm labour (group 10, 8.1%). Statistically significant differences in caesarean section rates between the study hospitals were observed in group 1 (nulliparous women with single cephalic full-term pregnancy and spontaneous labour), group 4 (multiparous with single cephalic full-term pregnancy with induced labour or prelabour caesarean section), group 5 (multiparous with single cephalic full-term pregnancy with previous caesarean section) and in group 7 (multiparous with breech presentation).

Conclusion

Women in groups 5, 8 and 10 were the largest contributors to the overall caesarean section rate in the study hospitals. Efforts to reduce the differences in obstetrical care between hospitals need to be directed towards increasing the proportion of vaginal births after caesarean section and by reducing primary caesarean section in multiple pregnancies and preterm labour.
Qualitative study to explore the views of general practice staff on the use of point-of-care C reactive protein testing for the management of lower respiratory tract infections in routine general practice in England
Authors: Eley Charlotte Victoria , Sharma Anita , Lecky Donna Marie , Lee Hazel , McNulty Cliodna Ann Miriam
Published: October 2018

Objectives

To explore the knowledge, skills, attitudes and beliefs of general practice staff about C reactive protein (CRP) point-of-care tests (POCTs) in routine general practice and associated barriers and facilitators to implementing it to improve the management of acute cough.

Design

A qualitative methodology including interviews and focus groups using the Com-B framework to understand individuals’ behaviour to implement CRP POCT in routine general practice. Data were analysed inductively and then aligned to the Com-B framework.

Setting

A service evaluation of CRP POCT over a 6-month period was previously conducted in randomly selected GP practices from a high prescribing National Health Service Clinicial Commissioning Groups in England. All 11 intervention practices (eight accepting CRPs; three declining CRPs) and the eight control practices, which were not offered CRP POCT, were also invited to interview. A further randomly selected practice not allocated to intervention or control was also invited to participate.

Participants

Seven of eight accepting CRP, one of three declining CRP and four of nine control practices consented to participate. 12 practices and 26 general practice staff participated; 11 interviews, 3 focus groups and 1 hand-written response.

Results

Participants reported that CRP POCT can increase diagnostic certainty for acute cough, inform appropriate management, manage patient expectations for antibiotics, support patient education and improve appropriate antibiotic prescribing. Reported barriers to implementing CRP POCT included: CRP cost, time, easy access to the POCT machine and effects on clinical workflow. Participants with greater CRP use usually had a dedicated staff member with the machine located in their consultation room.

Conclusions

CRP POCT can help general practice staff improve patient care and education if incorporated into routine care, but this will need enthusiasts with dedicated POCT instruments or smaller, cheaper, more portable machines. In addition, funding will be needed to support test costs and staff time.
Preoperative cigarette smoking and short-term morbidity and mortality after cardiac surgery: a meta-analysis
Authors: Bayfield Nicholas Gregory Ross , Pannekoek Adrian , Tian David Hao
Published: October 2018

Currently, the choice of whether or not to electively operate on current smokers is varied among cardiothoracic surgeons. This meta-analysis aims to determine whether preoperative current versus ex-smoking status is related to short-term postoperative morbidity and mortality in cardiac surgical patients. Systematic literature searches of the PubMed, MEDLINE and Cochrane databases were carried out to identify all studies in cardiac surgery that investigated the relationship between smoking status and postoperative outcomes. Extracted data were analysed by random effects models. Primary outcomes included 30-day or in-hospital all-cause mortality and pulmonary morbidity. Overall, 13 relevant studies were identified, with 34 230 patients in current or ex-smoking subgroups. There was no difference in mortality (p=0.93). Current smokers had significantly higher risk of overall pulmonary complications (OR 1.44; 95% CI 1.27 to 1.64; p<0.001) and postoperative pneumonia (OR 1.62; 95%  CI 1.27 to 2.06; p<0.001) as well as lower risk of postoperative renal complications (OR 0.82; 95%  CI 0.70 to 0.96; p=0.01) compared with ex-smokers. There was a trend towards an increased risk of postoperative MI (OR 1.29; 95%  CI 0.95 to 1.75; p=0.10). No difference in postoperative neurological complications (p=0.15), postoperative sternal surgical site infections (p=0.20) or postoperative length of intensive care unit stay (p=0.86) was seen. Cardiac surgical patients who are current smokers at the time of operation do not have an increased 30-day mortality risk compared with ex-smokers, although they are at significantly increased risk of postoperative pulmonary complications.
Out-of-hospital initiation of hypothermia in ST-segment elevation myocardial infarction: a randomised trial
Authors: Testori Christoph , Beitzke Dietrich , Mangold Andreas , Sterz Fritz , Loewe Christian , Weiser Christoph , Scherz Thomas , Herkner Harald , Lang Irene
Published: October 2018

Objective

To evaluate the effect of prereperfusion hypothermia initiated in the out-of-hospital setting in awake patients with ST-segment elevation myocardial infarction (STEMI) on myocardial salvage measured by cardiac MRI (CMR).

Methods

Hypothermia was initiated within 6 hours of symptom onset by the emergency medical service with surface cooling pads and cold saline, and continued in the cath lab with endovascular cooling (target temperature: ≤35°C at time of reperfusion). Myocardial salvage index (using CMR) was compared in a randomised, controlled, open-label, endpoint blinded trial to a not-cooled group of patients at day 4±2 after the event.

Results

After postrandomisation exclusion of 19 patients a total of 101 patients were included in the intention-to-treat analysis (control group: n=54; hypothermia group: n=47). Target temperature was reached in 38/47 patients (81%) in the intervention group. Study-related interventions resulted in a delay in time from first medical contact to reperfusion of 14 min (control group 89±24 min; hypothermia group 103±21 min; p<0.01). Myocardial salvage index was 0.37 (±0.26) in the control group and 0.43 (±0.27) in the hypothermia group (p=0.27). No differences in cardiac biomarkers or clinical outcomes were found. In a CMR follow-up 6 months after the initial event no significant differences were detected.

Conclusion

Out-of-hospital induced therapeutic hypothermia as an adjunct to primary percutaneous coronary intervention did not improve myocardial salvage in patients with STEMI.

Trial registration number

NCT01777750
Silencing of Astrocyte elevated gene-1 (AEG-1) inhibits proliferation, migration, and invasiveness, and promotes apoptosis in pancreatic cancer cells
Authors: Yang Xing , Song Shaowei
Published: October 2018

To investigate the role of Astrocyte elevated gene-1 (AEG-1) in the development and progress of pancreatic cancer, short hairpin RNA (shRNA) was inserted into the RNA interference vector to knock-down the endogenous AEG-1 in two pancreatic cancer cell lines: AsPC-1 and PANC-1. Our results showed that silencing of AEG-1 suppressed the proliferation, colony formation ability, and cell stemness of AsPC-1 and PANC-1 cells, and inhibited their G1-to-S phase transition. Results from apoptosis assay showed that knock-down of AEG-1 led to cell apoptosis. The expression of anti-apoptotic Bcl-2 was downregulated and that of the pro-apoptotic Bax and cleaved caspase-3 was upregulated in AEG-1-silenced pancreatic cancer cells. Further, the capability of AEG-1-silenced cells to migrate and to invade through the Matrigel-coated membrane was weaker, and the expression of matrix metallopeptidase 2 (MMP-2) and MMP-9 were decreased. Moreover, the AKT–β-catenin signaling pathway was inhibited in the cells with knock-down of AEG-1. In addition, the growth of xenograft tumors formed by AsPC-1 and PANC-1 cells was suppressed by AEG-1 shRNA. In conclusion, our study demonstrates that pancreatic cancer cells require AEG-1 to maintain their survival and metastasis, suggesting AEG-1 as a potential target for the treatment of pancreatic cancers.
DIRECT RECIPROCITY AND SERIAL RECIPROCITY: AN EXPERIMENTAL ANALYSIS
Authors: LI JINGPING
Published: October 2018

In this paper, we experimentally examine the relative strength of direct reciprocity and serial reciprocity. In three between–subject treatments, we solicit individual’s direct reciprocal giving and serial reciprocal giving in incentivized experiments where subjects make single or joint giving decisions. We find that, for both single and joint decisions, direct reciprocal giving and serial reciprocal giving are equivalent in magnitude. Meanwhile, an additional option of giving causes subjects to adjust their allocations between themselves and others, but this increase in total giving is not proportional to the increase in the number of recipients. This study provides new evidence of the complex relationship between direct reciprocity and serial reciprocity.
Excited weak bosons and dark matter
Authors: Fritzsch Harald
Published: October 2018

The weak bosons are bound states. The state with the lowest mass is identified with the boson, which has been discovered at the LHC. The p-wave excitations are studied. Specific properties of the excited bosons are discussed, in particular their decays into weak bosons and photons. The stable fermion, consisting of three fermions, provides the dark matter in our universe.
Exact Solution for Free Vibration and Buckling of Sandwich S-FGM Plates on Pasternak Elastic Foundation with Various Boundary Conditions
Authors: Singh S. J. , Harsha S. P.
Published: October 2018

In the present study, free vibration and buckling characteristics of a sandwich functionally graded material (FGM) plate resting on the Pasternak elastic foundation have been investigated. The formulation is based on non-polynomial higher-order shear deformation theory with inverse hyperbolic shape function. A new modified sigmoid law is presented to compute the effective material properties of sandwich FGM plate. The governing equilibrium equations have been derived using Hamilton’s principle. Non-dimensional frequencies and critical buckling loads are evaluated by considering different boundary conditions based on admissible functions satisfying the desired primary and secondary variables. Comprehensive parametric studies have been performed to analyze the influence of geometric configuration, volume fraction exponent, elastic medium parameter, and non-dimensional load parameter on the non-dimensional frequency and critical buckling load. These parametric studies have been done for various boundary conditions and different configurations of the sandwich plate. The computed results can be used as a benchmark for future comparison of sandwich S-FGM plates.
Determination of Critical and Cancellation Speeds of Euler–Bernoulli Beam Subject to a Continuously Moving Load
Authors: Bashmal Salem
Published: October 2018

Treated herein is an elastic beam that is subjected to a constant load that travels continuously (back and forth) along its span. The dynamic deflection of the beam is investigated analytically so as to predict the critical and cancellation speeds. Closed-form solutions are obtained for the damped system for each load condition and superimposed to determine the total solution of the response. Unlike the classical case of load traveling at constant speed in one direction, multiple resonance peaks are observed for reciprocating load at speeds that are lower than the classical critical speed. It is also observed that resonance may not exist at the classical critical speed for simply supported beams due to the symmetry of the beam. The dynamic deflection is examined for simply supported beams to determine the speeds that cause amplification or cancellation of the free response. The current load condition may have possible application in view of its potential use for vibration suppression, as a moving vibration absorber, or for magnification, in energy harvesting. The results are interpreted in order to understand the variation of dynamic deflection and to estimate the critical speeds for different load conditions.
Deformation Behavior of Fiber-Reinforced Hydrogel Structures
Authors: Zhou Yu , Hu Jianying , Liu Zishun
Published: October 2018

Proposed herein is a new theory for the anisotropic deformation of fiber-reinforced hydrogels. This new model takes into account the real fabrication of the fiber-reinforced hydrogels, in which the hydrogels are polymerized with fibers and polymer solutions. The new free energy function is established by adding the anisotropic free energy component contributed by fibers into the Flory–Rehner model. The proposed model is implemented through a user-defined material subroutine (UMAT) in the finite element software package ABAQUS. In particular, the consistent tangent modulus is derived in detail. Then, several illustrative examples with analytical and numerical results are demonstrated. In order to study deformation behavior of natural materials, we design some simple bilayer structures to mimic the opening of seedpods and the closure of flowers, in which the buckling behavior of fiber-reinforced hydrogels have been demonstrated. We hope that the proposed approach may help to study more complex deformation phenomena in hydrogel structures.
Self-Generation of Optimal Exciting Motions for Identification of a Humanoid Robot
Authors: Bonnet Vincent , Pfeiffer Kai , Fraisse Philippe , Crosnier André , Venture Gentiane
Published: October 2018

Knowledge of the inertial parameters of a humanoid robot is crucial for the development of model-based controllers or realistic simulation and motion planning in dynamic situations. Inertial parameters are usually provided from CAD data and thus are inaccurate especially if the robot is modified over time. Recent results showed that the inertial parameters specific to each robot can be identified using the external ground reaction forces and moments. However, the identification accuracy intrinsically depends on the excitation properties of the recorded motion and of the system’s specific level of measurement artefact/noise. In this paper, a new method for obtaining a system’s specific pseudo-online optimal set of optimal exciting motions (OEM) is proposed. This method is based on a real-time balance controller and on an optimization process to generate OEM while handling mechanical constraints. The method was experimentally validated with an NAO humanoid robot and a laboratory grade force-plate. The method shows a reduction of 1.6 times in average of the RMS difference between measured external ground reaction forces and moments and their estimates from CAD data.
An Efficient Motion Generation Method for Redundant Humanoid Robot Arm Based on the Intrinsic Principles of Human Arm Motion
Authors: Li Meng , Guo Weizhong , Lin Rongfu , Wu Changzheng , Han Liangliang
Published: October 2018

The aim of this paper is trying to propose an efficient method of inverse kinematics and motion generation for redundant humanoid robot arm based on the intrinsic principles of human arm motion. The intrinsic principle analysis takes into account both the skeletal kinematics and muscle strength properties. Firstly, this work analyzed the kinematic redundancy problem of a human arm. By analyzing the biological feature of a human arm, the kinematic redundancy boils down to the uncertainty of elbow position. Secondly, because the muscle’s kinematic and strength properties are critical for simulating biometric motion authentically, the muscle strength property was introduced as the criterion for configuration identification and motion generation. Three types of limb configuration, dog walking, gecko climbing, and human walking limb configuration were analyzed, and two geometrical configuration identification rules were deduced to generate biomimetic motion for humanoid robotic arms. By comparing the proposed method with other five IK methods, the proposed method significantly deduced the computing time. Finally, the configuration identification rules were used to generate motions for a 7-DoF humanoid robotic arm. The results showed that the biological rules can generate biomimetic, smooth arm motions for a redundant humanoid robotic arm.
The Book Review Column
Authors: Green Frederic
Published: October 2018

In this column we review these three books: 1. Compact Data Structures - A Practical Approach, by Gonzalo Navarro. An unusual approach focussing on data structures that use as little space as is theoretically possible, while maintaining practicality. Review by Laszlo Kozma. 2. Power Up: Unlocking the Hidden Mathematics in Video Games, by Matthew Lane. A revealing look at the mathematics, physics, and computer science that underlies (good) video games, with special attention to their potential valuable role in education. Review by S. V. Nagaraj. 3. Probability and Computing: Randomization and Probabilistic Techniques in Algorithms and Data Analysis (Second Edition), by Michael Mitzenmacher and Eli Upfal. The second edition2 of a distinguished text on a rich area that is central to computer and data science. Review by Aravind Srinivasan. Many thanks to these and all reviewers over the years who have graciously volunteered this valuable service to the community! Interested in reviewing? I hope so. Remember the perks: Learning (more?) about a field that interests you, a review on these pages, and a free book! The books listed on the next two pages are available, but the list is not exhaustive: I'm open to suggestions.
Technical Report Column
Authors: Kelley Dean
Published: October 2018

Welcome to the Technical Reports Column. If your institution publishes technical reports that you'd like to have included here, please contact me at the email address above.
Open Problems Column
Authors: Gasarch William
Published: October 2018

This issue's Open Problem Column is by Stephen Fenner, Fred Green, and Steven Homer. It is titled: Fixed-Parameter Extrapolation and Aperiodic Order: Open Problems. It is not on xedparameter tractability. It is on a generalization of the geometric notion of convexity.
Fixed-Parameter Extrapolation and Aperiodic Order
Authors: Fenner Stephen , Green Frederic , Homer Steven
Published: October 2018

For a number of years we have been investigating the geometric and algebraic properties of a family of discrete sets of points in Euclidean space generated by a simple binary operation: pairwise affine combination by a xed parameter, which we call xed-parameter extrapolation. By varying the parameter and the set of initial points, a large variety of point sets emerge. To our surprise, many of these sets display aperiodic order and share properties of so-called \quasicrystals" or \quasilattices." Such sets display some ordered crystal-like properties (e.g., generation by a regular set of local rules, such as a nite set of tiles, and possessing a kind of repetitivity), but are \aperiodic" in the sense that they have no translational symmetry. The most famous of such systems are Penrose's aperiodic tilings of the plane [16]. Mathematically, a widely accepted way of capturing the idea of aperiodic order is via the notion of Meyer sets, which we de ne later. Our goal is to classify the sets generated by xed-parameter extrapolation in terms of a number of these properties, including but not limited to aperiodicity, uniform discreteness, and relative density. We also seek to determine exactly which parameter values lead to which types of sets.
Column
Authors: Hemaspaandra Lane A. , Spakowski Holger
Published: October 2018

Ten years ago, Gla'er, Pavan, Selman, and Zhang [GPSZ08] proved that if P 6= NP, then all NP-complete sets can be simply split into two NP-complete sets. That advance might naturally make one wonder about a quite di erent potential consequence of NP-completeness: Can the union of easy NP sets ever be hard? In particular, can the union of two non-NP-complete NP sets ever be NP-complete? Amazingly, Ladner [Lad75] resolved this more than forty years ago: If P 6= NP, then all NP-complete sets can be simply split into two non-NP-complete NP sets. Indeed, this holds even when one requires the two non-NP-complete NP sets to be disjoint. We present this result as a mini-tutorial. We give a relatively detailed proof of this result, using the same technique and idea Ladner [Lad75] invented and used in proving a rich collection of results that include many that are more general than this result: delayed diagonalization. In particular, the proof presented is based on what one can call team diagonalization (or if one is being playful, perhaps even tag-team diagonalization): Multiple sets are formed separately by delayed diagonalization, yet those diagonalizations are mutually aware and delay some of their actions until their partner(s) have also succeeded in some coordinated action. We relatedly note that, as a consequence of Ladner's result, if P 6= NP, there exist OptP functions f and g whose composition is NP-hard yet neither f nor g is NP-hard.
2018 Knuth Prize is Awarded to Johan Håstad
Authors: Teng Sheng-Hua
Published: October 2018

The 2018 Donald E. Knuth Prize will be awarded to Johan Håstad of KTH Royal Institute of Technology for his long and sustained record of milestone breakthroughs at the foundations of computer science, with huge impact on many areas including optimization, cryptography, parallel computing, and complexity theory. Håstad's multiple seminal works have not only resolved longstanding deepest problems central to circuit lower bounds, pseudorandom generation, and approximability, but also introduced transformative techniques that have fundamentally influenced much of the subsequent work in these areas.
Capitalizing on Insights from Human Genetics to Identify Novel Therapeutic Targets for Coronary Artery Disease
Authors: Young Erica P. , Stitziel Nathan O.
Published: October 2018

Coronary artery disease (CAD) is a major cause of morbidity and mortality. Unfortunately, despite decades of research focused on disease pathogenesis, we still lack a sufficient pharmacopeia for preventing CAD. The failure of many novel cardiovascular drugs to improve clinical outcomes reflects the major substantial challenge of drug development: identifying causal mechanisms that can be therapeutically manipulated to lower disease risk. Identifying genetic variants that are associated with risk of CAD has emerged as a clear path toward improving our understanding of the underlying mechanisms that lead to disease and to the development of new therapies. Here, we review the potential utility and limitations of using human genetics to guide the identification of therapeutic targets for CAD.
Cadherin-11 as a regulator of valve myofibroblast mechanobiology
Authors: Bowler Meghan A. , Bersi Matthew R. , Ryzhova Larisa M. , Jerrell Rachel J. , Parekh Aron , Merryman W. David
Published: October 2018

Cadherin-11 (CDH11) is upregulated in a variety of fibrotic diseases, including arthritis and calcific aortic valve disease. Our recent work has identified CDH11 as a potential therapeutic target and shown that treatment with a CDH11 functional blocking antibody can prevent hallmarks of calcific aortic valve disease in mice. The present study investigated the role of CDH11 in regulating the mechanobiological behavior of valvular interstitial cells believed to cause calcification. Aortic valve interstitial cells were harvested from Cdh11+/+, Cdh11+/−, and Cdh11−/− immortomice. Cells were subjected to inflammatory cytokines transforming growth factor (TGF)-β1 and IL-6 to characterize the molecular mechanisms by which CDH11 regulates their mechanobiological changes. Histology was performed on aortic valves from Cdh11+/+, Cdh11+/−, and Cdh11−/− mice to identify key responses to CDH11 deletion in vivo. We showed that CDH11 influences cell behavior through its regulation of contractility and its ability to bind substrates via focal adhesions. We also show that transforming growth factor-β1 overrides the normal relationship between CDH11 and smooth muscle α-actin to exacerbate the myofibroblast disease phenotype. This phenotypic switch is potentiated through the IL-6 signaling axis and could act as a paracrine mechanism of myofibroblast activation in neighboring aortic valve interstitial cells in a positive feedback loop. These data suggest CDH11 is an important mediator of the myofibroblast phenotype and identify several mechanisms by which it modulates cell behavior.

NEW & NOTEWORTHY Cadherin-11 influences valvular interstitial cell contractility by regulating focal adhesions and inflammatory cytokine secretion. Transforming growth factor-β1 overrides the normal balance between cadherin-11 and smooth muscle α-actin expression to promote a myofibroblast phenotype. Cadherin-11 is necessary for IL-6 and chitinase-3-like protein 1 secretion, and IL-6 promotes contractility. Targeting cadherin-11 could therapeutically influence valvular interstitial cell phenotypes in a multifaceted manner.
BMI1 promotes cardiac fibrosis in ischemia-induced heart failure via the PTEN-PI3K/Akt-mTOR signaling pathway
Authors: Yang Wenbo , Wu Zhijun , Yang Ke , Han Yanxin , Chen Yanjia , Zhao Weilin , Huang Fanyi , Jin Yao , Jin Wei
Published: October 2018

Cardiac fibrosis has been known to play an important role in the etiology of heart failure after myocardial infarction (MI). B lymphoma Mo-MLV insertion region 1 homolog (BMI1), a transcriptional repressor, is important for fibrogenesis in the kidneys. However, the effect of BMI1 on ischemia-induced cardiac fibrosis remains unclear. BMI1 was strongly expressed in the infarct region 1 wk post-MI in mice and was detected by Western blot and histological analyses. Lentivirus-mediated overexpression of BMI1 significantly promoted cardiac fibrosis, worsened cardiac function 4 wk after the intervention in vivo, and enhanced the proliferation and migration capabilities of fibroblasts in vitro , whereas downregulation of BMI1 decreased cardiac fibrosis and prevented cardiac dysfunction in mice 4 wk post-MI in vivo. Furthermore, upregulated BMI1 inhibited phosphatase and tensin homolog (PTEN) expression, enhanced phosphatidylinositol 3-kinase (PI3K) expression, and increased the phosphorylation level of Akt and mammalian target of rapamycin (mTOR) in mice 4 wk after lentiviral infection, which was in accordance with the changes seen in their infarcted myocardial tissues. At the same time, the effects of BMI1 on cardiac fibroblasts were reversed in vitro when these cells were exposed to NVP-BEZ235, a dual-kinase (PI3K/mTOR) inhibitor. In conclusion, BMI1 is associated with cardiac fibrosis and dysfunction after MI by regulating cardiac fibroblast proliferation and migration, and these effects could be partially explained by the regulation of the PTEN-PI3K/Akt-mTOR pathway.

NEW & NOTEWORTHY Ischemia-induced B lymphoma Mo-MLV insertion region 1 homolog (BMI1) significantly promoted cardiac fibrosis and worsened cardiac function in vivo, whereas downregulation of BMI1 decreased cardiac fibrosis and prevented cardiac dysfunction in myocardial infarcted mice. BMI1 also enhanced proliferation and migration capabilities of fibroblasts in vitro; these effects were reversed by NVP-BEZ235. Effects of BMI1 on cardiac fibrosis could be partially explained by regulation of the phosphatase and tensin homolog-phosphatidylinositol 3-kinase/Akt-mammalian target of rapamycin pathway.