bluuebunny/crossref_metadata_2025 huggingface dataset:
Non-Linear Damping Identification in Nuclear Systems Under External Excitation
Authors: Delannoy Joachim , Amabili Marco , Matthews Brett , Painter Brian , Karazis Kostas
Published: March 2016

In Pressurized Water Reactors (PWR) the fluid-structure interaction between the coolant and fuel assemblies is an important phenomenon that is directly associated to safety and performance issues for the nuclear industry. Fuel assemblies are formed by bundling fuel rods, long slender pressurized tubes containing uranium pellets, with hollow guide and instrumentation tubes using a number of spacer grids for support. In order to correctly simulate the response of a fuel assembly under external excitation, an investigation of the system damping is necessary.

Recent study shows that the damping may grow significantly with the vibration amplitude, increasing the safety factor. In order to address this issue, the present study has developed a tool to identify the vibration characteristics of non-linear mechanical systems from experimental forced vibration data obtained at different excitation levels. In particular, this project focuses on the damping identification. A parameter identification methodology for non-linear systems, based on harmonic balance method, is used to identify the damping governing the motion of such systems.

The tool has been developed by using hardening non-linear responses of two sandwich panel and a metal plate subjected to external harmonic excitation. The method has been validated by comparison with the damping identified by the full non-linear model of the two sandwich panels. In the three cases, an increase of damping with the vibration amplitude is found and discussed.
Unsteady Lift for Impulsively Started Transonic/Supersonic Flow
Authors: Bai Chen-Yuan , Li Juan , Wu Zi-Niu
Published: March 2016

The unsteady lift for incompressible starting flow of a flat plate at high angle of attack involves a repeatable three-phase variation: (a) initial lift drop, (b) a Wagner type lift increase enhanced by leading edge vortex and (c) a lift drop due to a lift-decreasing trailing edge vortex spiral induced by the leading edge vortex convected to the trailing edge. For compressible starting flow at small angle of attack, it is well known that the lift experiences an initial drop due to piston effect and then a Wagner type lift increase enhanced by compressibility. The third phase has not been reported in the past. In this paper we consider subsonic, transonic and supersonic starting flow at high angle of attack. Numerical computation using computational fluid dynamics is used to compute the flow and lift behavior is explained using existing theories. It is found that, when the angle of attack is 20 degrees, we still observe the three-phase lift variation for Mach number below 0.8. The second conclusion is that the lift during the Wagner type increase phase is a decreasing function of the Mach number, in contrast to what we know from piston and indicial function method for small angle of attack. Another important conclusion is, when the Mach number is high enough, say above 0.9, only two-phase variation is observed: (a) initial lift drop and (b) Wagner type lift increase. For supersonic starting flow the Wagner type lift increase is replaced by a linear increase.
New Approaches for Improved Efficiency and Flexibility in Process Chains of Press Hardening
Authors: Landgrebe Dirk , Schönherr Julia , Pierschel Norbert , Polster Stefan , Mosel Andre , Schieck Frank
Published: March 2016

In the last decade, press hardening has become a fully established technology in both science and industry for the production of ultra-high-strength structural components, especially in the automotive industry. Beside the improvement of car performance such as safety and lightweight design, the production process is also one focus of trends in technology development in the field of press hardening.

This paper presents an overview about alternative approaches for optimized process chains of press hardening, also including pre- and post-processing in addition to the actual forming and quenching process. Investigations on direct contact heating technology show new prospects regarding fast and flexible austenitization of blanks at compact device dimensions. By applying high speed impact cutting (HSIC) for trimming of press hardened parts, an alternative technology is available to substitute the slow and energy-intensive laser trimming in today’s press hardening lines. Combined with stroke-to-stroke control based on measuring of process-relevant parameters, a readjustment of the production line is possible in order to produce each part with individual, optimal process parameters to realize zero defect production of property-graded press hardened components with constant high part quality.

Significant research in the field of press hardening was carried out at Fraunhofer Institute for Machine Tools and Forming Technology IWU, in the hot forming model process chain which enables the running of experiments under conditions similar to industrial scales. All practical tests were prepared by design of experiments and assisted by thermo-mechanical FE simulations.
Thermal Error Modeling and Prediction of a Heavy Floor-Type Milling and Boring Machine Tool
Authors: Li Fengchun , Li Tiemin , Wang Haitong
Published: March 2016

Thermal error modeling and prediction of a heavy floor-type milling and boring machine tool was studied in this paper. An FEA model and a thermal network of the machine tool’s ram was established. The influence of boundary conditions on thermal error was studied to find out the boundary conditions that needn’t to be calculated precisely, reducing the time cost of the work. Superposition principle of heat sources was used in the FEA to get the simulation data of thermal error and temperature. A model based on the simulation data was established to predict the thermal error during the work process. An experiment was performed to verify the accuracy of the model. The result shows that the model accuracy is 87%. The method in this paper is expected to be used in engineering application.
Bringing Uniformity in Topic Coverage and Grading Fairness in Multiple Sections of an Engineering Course
Authors: Karimi Amir
Published: March 2016

In large engineering departments, multiple sections of an engineering course are typically offered during a single semester to accommodate student enrollment demands. At times, multiple sections of a single course are taught by the same instructor, but very often, they are taught by different instructors. Having different instructors teaching various sections of the same course provides opportunities for students to select the instructor of their choice. But it also may create unfairness in grades received by all students taking the same course. Since the grading scale can vary significantly among the instructors, the grade distribution in various sections of the same course can also vary significantly. Some students, who pass a course with one instructor, might not be able to pass the same course if the course is taken with another instructor. One way to resolve this problem is for the instructors to coordinate their efforts in the way they are teaching the course and evaluating student knowledge. In fall 2014, and spring 2015 two instructors who were teaching two sections of a senior level engineering course collaborated in providing a uniform coverage of course topics and coordinated their efforts in assessing knowledge of all students enrolled in both sections. They worked together to put similar emphasize on the topics covered in the course. The weight of each exam, homework assignments, and projects counted towards the final exam were agreed upon at the start of the semester. Exam questions were developed and graded by both instructors. The benefits of coordination in teaching and evaluating the student knowledge uniformly are discussed. Lesson learned in this experiment are also included.
Static Strength Design of Small Wind Turbine Blade Using Finite Element Analysis and Testing
Authors: Kale Sandip , Hugar Jagadeesh
Published: March 2016

Today, wind power has become the most accepted renewable energy source and contributing major share in renewable energy market. Large wind turbines are now producing power effectively and delivering satisfactory performance to satisfy researchers, scientists, investors and governments. Large wind turbine technology has achieved respectable position across the globe. In addition to large wind turbine technology, it is observed that small wind technology has started movement toward a satisfactory growth. A considerable growth is forecasted by many experts in coming decades. The small wind turbine technology can be accepted by market if industry will provide small wind turbines with good desirable characteristics. Self starting behavior at a low wind speed, affordable compatible cost, maintenance free wind turbine system, low weight, reliable and satisfactory performance in low wind will always receive significant attraction of people for various applications. Low weight tower-top system and hence supporting structure, light weight and efficient generator, rotor’s ability to efficient wind to mechanical energy conversion and components manufacturing simplicity are also always expected by wind turbine users. This work is one of the attempts to design and develop a blade for small wind turbine in the line of objectives stated. Wind turbine blade is most important element in wind turbine system which converts wind energy in to mechanical energy. In addition to efficient aerodynamic blade design its strength design is also important so that it can withstand against various loads acting on it. Wind turbine blades strength has been analyzed by different researchers by conducting their static and fatigue testing. The objective of present work is to perform static strength test for newly developed blade of 1.5 m length. This newly developed blade consists of two new airfoils. A thick airfoil is used at the root and thin airfoil is used for remaining sections. The different loads acting on the blade are calculated using Blade Element Momentum theory at survival wind speed. It is decided to manufacture this blade using glass fiber reinforced plastic. The properties of material combination used are determined as per ASTM norms. The computational strength analysis is carried out using ANSYS. During this analysis blade is considered as a cantilever beam and equivalent load is applied. The blade is also tested experimentally using strain gauges. From both result analyses, it is found that developed blade is capable to take various loads acting on wind turbine blade at survival wind speed.
Reduction of Chatter Using a Probabilistic Approach
Authors: Endeshaw Haileyesus , Alemayehu Fisseha , Ekwaro-Osire Stephen
Published: March 2016

Industrial robots are widely used in numerous industrial plants usually to perform repetitive, difficult or hazardous tasks such as polishing, grinding, milling, deburring, and welding. However, their relatively low stiffness prohibits the robots from machining of metallic materials accurately. Besides, the resulting vibration causes reduced tool life. One of the main problems with robot machining is chatter. Although many researchers have studied this problem for a while, they were not able to fully eliminate chatter due to the complexity of the problem which arises from many factors including cutting parameters, cutting tool and work-piece material. Several studies have been conducted to predict the occurrence of chatter. However, many of them lack the important element in predicting chatter: the element of uncertainty. It is important to consider uncertainty in predicting chatter since the parameters associated are inherently uncertain. This study implements probabilistic approach to predict chatter considering the uncertainty in machining parameters. The magnitude of cutting force is used to determine whether a chatter has occurred or not. The research question of this study is ‘Can a probabilistic analysis be used to predict chatter occurrence?’ To answer the research question, the following specific aims were developed: (1) develop a framework for predicting chatter occurrence, and (2) perform probabilistic analysis of chatter occurrence. The framework consists of a multibody modeling software (ADAMS), probabilistic analysis software (NESSUS) and MATLAB which is used as an interfacing platform. The probabilistic analysis implemented in the framework provides two important results. Firstly, it determines the probability of occurrence of chatter. Secondly, it provides sensitivity analysis that shows most important parameters which instigate chatter.
A Numerical Study on Mechanical Performance and Hemolysis for Different Types of Centrifugal Blood Pumps
Authors: Chang Minwook , Hur Nahmkeon , Moshfeghi Mohammad , Kang Seongwon , Kim Wonjung , Kang Shin Hyoung
Published: March 2016

Centrifugal blood pumps have to be considered from both mechanical and biomechanical aspects. While, evaluations of mechanical factors, such as performance curve, are straightforward, biomechanical parameters, such as hemolysis indices, are still indistinct. Hence, different mathematical models and computational methods have been employed for the evaluation of hemolysis indices. This article aims to investigate four different types of centrifugal blood pumps from both mechanical and biomechanical aspects. The pumps are cone-type impeller (Type-A), channel-type impeller with shroud (Type-B), open impeller without shroud (Type-C) and shrouded impeller-type (Type-D). The CFD simulations are conducted using standard k-ε turbulence model in multiple reference frame (MRF) method. Various values for rotational speed and flow rate are studied. The streamlines clearly show the effects of impeller geometry on flow patterns. It is also demonstrated that in all of the models, the areas of the recirculation have high value of von Mises stress. In addition, the effect of the volute in the Type-D on the pressure distribution and streamline smoothness is clearly observed. In another part, the modified index of hemolysis (MIH) calculated based on Eulerian approach is investigated for three predefined conditions of extracorporeal membrane oxygenation (ECMO), ventricular assist device (VAD), and full-load. The results reveal that the Type-A and Type-D have the highest and lowest MIH values, respectively in all of the predefined conditions. In addition, all of the pumps generate lower amount of hemolysis when they are operated in VAD condition.
Investigation of the Relation Between Tube Spacing and Tube Sheet Deformation in Heat Exchangers due to the Mechanical Rolling Process: A Numerical Study
Authors: Madsen Søren Bøgelund , Ibsen Claus Hessler , Gervang Bo , Kristensen Anders Schmidt
Published: March 2016

The focus of this paper is a numerical investigation of tubesheet deformation in tube-tubesheet joints used in tube bank heat exchangers. To increase the thermal performance of a cooler the tubes can be moved closer together to increase turbulence and the heat transfer coefficient. Reducing the tube spacing is an alternative to using finned tubes to increase thermal performance. Finned tubes is more susceptible to fouling and therefore the small tube spacing can be an attractive alternative in some cases. From a manufacturing point of view, there are some problems with small tube spacing. When the tube spacing is reduced the deformation of the tube sheet increases. The relation between the tube spacing and tubesheet deformation is of great interest to the thermal designers of heat exchangers since it sets a limit for the tube spacing. The limit depends on how much tube sheet deformation is acceptable in the design. In most cases, the tubes are joined to the tube sheet by an expansive cold forming process. The expansion process that is investigated in this paper is the mechanical rolling expansion process. The tube is plastically deformed by a series of hardened steel rollers that roll across the inner tube surface while being pushed outwards. This results in a residual contact pressure between the tube and tube sheet after relaxation/springback. The expansion process is modeled using finite elements, the model used is a 2D plane-strain model that is capable of capturing the effect of adjacent holes. This approach is new compared to previous research done in the field of mechanical roll expansion where the most commonly used model is an axisymmetric model. It is however not possible to investigate tube sheet deformation versus tube spacing with the axisymmetric model since it doesn’t include the effect of adjacent holes. The material used in the analysis is a typical stainless steel, the material is modeled using a bilinear isotropic hardening model. At some point, the deformation of the tube sheet will exponentially increase with reduced tube spacing. This effect can only be investigated using numerical tools. Too much tube sheet deformation is not desirable since it will cause the tube sheet to permanently change shape and in some cases, adjacent tube-tubesheet joints will be compromised due to the nearby expansion. The results of this paper is the relation between the tube spacing and the amount of tubesheet deformation for a given amount of apparent tube wall reduction. This relation is used to set up limits for the amount of expansion and the minimum tube spacing for the given material combination.
Experimental Study on Screech Suppression of Supersonic Free Jet Through Rectangular Nozzle
Authors: Chen Zhe , Wu Jiu-Hui , Chen Xin , Lei Hao , Ren Adan
Published: March 2016

The paper conducted a series of experimental study on V-shaped grooves influence of supersonic free jet through rectangular nozzles, such as two different screech modes, changing rules of sound pressure level of the screech mode, 3D-dynamic spectrum of sound pressure and schlieren photographs of the flow field. The experimental results show that V-shaped grooves on rectangular nozzle could reduce the acoustic feedback of shock wave from jet flow, so as to eliminate one mode of screech completely). It is also suggest that V-shaped grooves performed differently on rectangular nozzle compared with circular one at high frequency when jet pressure was high. Several fundamental frequency differentials exist in both two rectangular nozzles at the same pressure, whereas fundamental frequency in non V-grooved nozzle is much smoother than the V-grooved one. The nozzle with V-shaped grooves had a significant noise suppression effect below 0.55MPa. An instantaneous spectrum comparison between V-grooved and non V-grooved nozzles in scope of 0.25∼0.40MPa was given. The SPL (Sound Pressure Level) differential increased at beginning, then decreased with the decline of jet pressure in low frequency below 10kHz. Nozzle with V-shaped grooves had a lower SPL. Nevertheless, an entirely different phenomenon was discovered in high frequency above 10kHz. When jet pressure was 0.40MPa, V-grooved rectangular nozzle had a higher SPL, and it approached to SPL of non V-grooved nozzle with decline of jet pressure until below it. Moreover, differentials gradually became obvious due to the mixing effect with different nozzle structure. Noise pressure in V-grooved nozzle dropped rapidly in range of 0.40∼0.80MPa, as well as lower SPL and widely frequency distribution. Impact of V-shaped grooves on schlieren photographs was analyzed. Flow at nozzle exit was strengthened by impact of V-shaped grooves. An obviously density gradient could be found in first shock-cell and length of cell was smaller than the one without grooves. The flow was more stable in other cells but in a weaker intensity. The V-shaped grooves could increase length of jet path as well as decrease expansion of the cells. In general, V-shaped grooves in rectangular nozzle performed differently from circular nozzle, which could suppress and even eliminate jet flow screech. During engineering application, the matching of V-shaped grooves in rectangular nozzle and pressure of jet flow should be taken into consider.
Polymer lenses with antireflection structures prepared using anodic porous alumina molds
Authors: Yanagishita Takashi , Hidaka Takeshi , Suzuki Mari , Masuda Hideki
Published: March 2016

In this study, a nanoimprinting process was used with anodic porous alumina as a mold to fabricate polymer lenses with antireflection structures. The antireflection structures were composed of a tapered pillar array, which served to suppress the reflectance of incident light of visible wavelengths. It was also demonstrated that polymer lenses with a tapered hole array on their surface could be obtained by injection molding using a Ni mold prepared through electroforming by depositing Ni with anodic porous alumina as a template. The polymer lenses with antireflection structures demonstrated in this study should be applicable for various types of functional optical devices, such as cameras, optical microscopes, etc.
Effects of Foot Strike and Step Frequency on Achilles Tendon Stress During Running
Authors: Lyght Michael , Nockerts Matthew , Kernozek Thomas W. , Ragan Robert
Published: March 2016

Achilles tendon (AT) injuries are common in runners. The AT withstands high magnitudes of stress during running which may contribute to injury. Our purpose was to examine the effects of foot strike pattern and step frequency on AT stress and strain during running utilizing muscle forces based on a musculoskeletal model and subject-specific ultrasound-derived AT crosssectional area. Nineteen female runners performed running trials under 6 conditions, including rearfoot strike and forefoot strike patterns at their preferred cadence, +5%, and –5% preferred cadence. Rearfoot strike patterns had less peak AT stress (P < .001), strain (P < .001), and strain rate (P < .001) compared with the forefoot strike pattern. A reduction in peak AT stress and strain were exhibited with a +5% preferred step frequency relative to the preferred condition using a rearfoot (P < .001) and forefoot (P=.005) strike pattern. Strain rate was not different (P > .05) between step frequencies within each foot strike condition. Our results suggest that a rearfoot pattern may reduce AT stress, strain, and strain rate. Increases in step frequency of 5% above preferred frequency, regardless of foot strike pattern, may also lower peak AT stress and strain.
The Influence of Minimalist and Maximalist Footwear on Patellofemoral Kinetics During Running
Authors: Sinclair Jonathan , Richards Jim , Selfe James , Fau-Goodwin James , Shore Hannah
Published: March 2016

The current study aimed to comparatively examine the effects of minimalist, maximalist, and conventional footwear on the loads experienced by the patellofemoral joint during running. Twenty male participants ran over a force platform at 4.0 m×s–1. Lower limb kinematics were collected using an 8-camera motion capture system allowing patellofemoral kinetics to be quantified using a musculoskeletal modeling approach. Differences in patellofemoral kinetic parameters were examined using one-way repeatedmeasures ANOVA. The results showed the peak patellofemoral force and pressure were significantly larger in conventional (4.70 ± 0.91 BW, 13.34 ± 2.43 MPa) and maximalist (4.74 ± 0.88 BW, 13.59 ± 2.63 MPa) compared with minimalist footwear (3.87 ± 1.00 BW, 11.59 ± 2.63 MPa). It was also revealed that patellofemoral force per mile was significantly larger in conventional (246.81 ± 53.21 BW) and maximalist (251.94 ± 59.17 BW) as compared with minimalist (227.77 ± 58.60 BW) footwear. As excessive loading of the patellofemoral joint has been associated with the etiology of patellofemoral pain symptoms, the current investigation indicates that minimalist footwear may be able reduce runners’ susceptibility to patellofemoral disorders.
Associations Between Step Duration Variability and Inertial Measurement Unit Derived Gait Characteristics
Authors: Rantalainen Timo , Hart Nicolas H. , Nimphius Sophia , Wundersitz Daniel W.
Published: March 2016

Inertial measurement units (IMU) provide a convenient tool for gait stability assessment. However, it is unclear how various gait characteristics relate to each other and whether gait characteristics can be obtained from resultant acceleration. Therefore, step duration variability was measured in treadmill walking from 39 young ambulant volunteers (age 24.2 [± 2.5] y; height 1.79 [± 0.09] m; mass 71.6 [± 12.0] kg) using motion capture. Accelerations and gyrations were simultaneously recorded with an IMU. Harmonic ratio, maximum Lyapunov exponents, and multiscale sample entropy (MSE) were calculated. Step duration variability was positively associated with MSE with coarseness levels = 3–6 (r = –.33 to –.42, P ≤ .045). Harmonic ratio and MSE with all coarseness levels were negatively associated (r = –.45 to –.57, P ≤ .004). The MSE with coarseness level = 2 was negatively associated with short-term maximum Lyapunov exponents (r = –.32, P = .047). The agreement between resultant and vertical acceleration derived gait characteristics was excellent (ICC = 0.97–0.99). In conclusion, MSE with varying coarseness levels was associated with the other gait characteristics evaluated in the study. Resultant and vertical acceleration derived results had excellent agreement, which suggests that resultant acceleration is a viable alternative to considering the acceleration dimensions independently.
Kras
rewires metabolic networks
Authors: Prabakaran Sudhakaran
Published: March 2016

A
Kras
mutation rewires metabolic networks in lung cancer cells to increase glucose uptake and reduce oxidative stress damage.
Role of the Cys154Arg Substitution in Ribosomal Protein L3 in Oxazolidinone Resistance in Mycobacterium tuberculosis
Authors: Makafe Gaëlle Guiewi , Cao Yuanyuan , Tan Yaoju , Julius Mugweru , Liu Zhiyong , Wang Changwei , Njire Moses M. , Cai Xingshan , Liu Tianzhou , Wang Bangxing , Pang Wei , Tan Shouyong , Zhang Buchang , Yew Wing Wai , Lamichhane Gyanu , Guo Jintao , Zhang Tianyu
Published: March 2016

We expressed the wild-type
rplC
and mutated
rplC
(Cys154Arg) genes, respectively, in
Mycobacterium tuberculosis
H37Ra and H37Rv in an attempt to delineate the role of
rplC
(Cys154Arg) regarding oxazolidinone resistance. An increase of the MICs of linezolid (LZD) and sutezolid (PNU-100480, PNU) against the recombinant mycobacteria with overexpressed
rplC
mutation (Cys154Arg) was found, suggesting the
rplC
gene is a determinant of bacillary susceptibilities to LZD and PNU.
Factors Associated with Time to Appropriate Treatment in Pertussis Cases in Georgia, 2009 to 2013
Authors: Goodenough Dana , Thomas Ebony , Tuttle Jessica , Bednarczyk Robert A.
Published: March 2016

Pertussis is endemic in the United States, with periodic epidemics that continue to highlight its importance as a public health issue. The clinical presentation of pertussis can vary by age and vaccination status. However, little is known about the factors that affect time to antibiotic treatment of pertussis cases. We analyzed 5 years of data from the Georgia Department of Public Health to understand how factors such as age, symptoms, and vaccination status can alter the clinical picture of pertussis and affect time to treatment. We used multivariable linear regression to assess the impact of each variable on time to antibiotic treatment. There was little consistency across age groups for symptom and demographic predictors of time to antibiotic treatment. Overall, the multivariate linear regression showed that among patients ≤18 years old, none of the variables had an impact on time to antibiotic treatment greater than −0.25 to 1.47 days. Among patients >18 years old, most variables had little impact on time to treatment, though two (paroxysmal cough in >18- to 40-year-olds and hospitalization in individuals over 40) were associated with an additional 5 days in time to treatment from cough onset. This study highlights how the difficulties in pertussis diagnosis, particularly among adults, can affect time to antibiotic treatment; adults may not begin antibiotic treatment until there is an accumulation of symptoms. Health care providers need to recognize the variety of symptoms that pertussis can present with and consider confirmatory testing early.
Crystal Structure of a Complex of Surfactant Protein D (SP-D) and Haemophilus influenzae Lipopolysaccharide Reveals Shielding of Core Structures in SP-D-Resistant Strains
Authors: Clark Howard W. , Mackay Rose-Marie , Deadman Mary E. , Hood Derek W. , Madsen Jens , Moxon E. Richard , Townsend J. Paul , Reid Kenneth B. M. , Ahmed Abdul , Shaw Amy J. , Greenhough Trevor J. , Shrive Annette K.
Published: March 2016

The carbohydrate recognition domains (CRDs) of lung collectin surfactant protein D (SP-D) recognize sugar patterns on the surface of lung pathogens and promote phagocytosis. Using
Haemophilus influenzae
Eagan strains expressing well-characterized lipopolysaccharide (LPS) surface structures of various levels of complexity, we show that bacterial recognition and binding by SP-D is inversely related to LPS chain extent and complexity. The crystal structure of a biologically active recombinant trimeric SP-D CRD complexed with a delipidated Eagan 4A LPS suggests that efficient LPS recognition by SP-D requires multiple binding interactions utilizing the three major ligand-binding determinants in the SP-D binding pocket, with Ca-dependent binding of inner-core heptose accompanied by interaction of anhydro-Kdo (4,7-anhydro-3-deoxy-
d
-manno-oct-2-ulosonic acid) with Arg343 and Asp325. Combined with enzyme-linked immunosorbent assays (ELISAs) and fluorescence-activated cell sorter (FACS) binding analyses, our results show that extended LPS structures previously thought to be targets for collectins are important in shielding the more vulnerable sites in the LPS core, revealing a mechanism by which pathogens with complex LPS extensions efficiently evade a first-line mucosal innate immune defense. The structure also reveals for the first time the dominant form of anhydro-Kdo.
Lu-177 labelled peptide treatment for radioiodine refractory differentiated thyroid carcinoma
Authors: Elboğa Umut , Özkaya Mesut , Sayiner Zeynel A , Çelen Yusuf Zeki
Published: March 2016

Differentiated thyroid carcinoma (DTC) has good prognosis but 5% of the patients already have distant metastasis at the diagnosis. Tumour cells can lose their iodine uptake ability and enter a state of dedifferentiation. Treatment for differentiated thyroid carcinoma that is not suitable for the local surgery and unresponsive to radioactive iodine uptake is not always easy for physicians. We present a case of a 64-year-old man who had total thyroidectomy surgery and central lymph node dissection with diagnosis of multinodular goitre disease. Histopathological evaluation was papillary thyroid cancer with tall cell variant. Treatment using 150 mCi radioiodine was administered to the patient three times but could not effect a cure. We performed Ga-68 labelled DOTATE (synthetic somatostatin analogue peptide). This provided a good outcome. As evident from our case, Lu-177 radionuclide labelled synthetic somatostatin analogue peptides have therapeutic effect on radioiodine refractory DTC, as an alternative treatment modality.
Eosinophilic colitis
Authors: Dionísio de Sousa Isabel José , Bonito Nuno , Pais Ana , Gervásio Helena
Published: March 2016

A 57-year-old man, diagnosed with colon cancer stage III in July/2010, underwent surgery and received adjuvant chemotherapy with FOLFOX 4 (5-fluorouracil; calcium folinate and oxaliplatin), which ended in March/2011 after 12-cycles. It was then decided to maintain periodical surveillance. About 1 year later, the patient developed several episodes of diarrhoea, mainly during the night, and presented persistent peripheral eosinophilia in the blood count (range 585–1300 eosinophils/µL). Colonoscopy was performed, with the histological result showing eosinophilic infiltration of the colon, compatible with eosinophilic colitis. The patient was treated with a short course of budesonide, achieving resolution of symptoms, and has remained asymptomatic.
The effect of provision of pain management advice on patient satisfaction with their pain management: a pilot, randomised, controlled trial (pain advice trial)
Authors: Taylor David McD , Grover Johnson Olivia , Lee Marina , Ding Juen Li , Ashok Aadith
Published: March 2016

Objective

We aimed to provide pain advice (‘The treatment of pain is very important and be sure to tell the staff when you have pain’) as an intervention and evaluate its effect upon patient satisfaction. The purpose of this pilot trial was to ensure the design and methods of a future trial are sound, practicable and feasible.

Method

We undertook a pilot, randomised, controlled, clinical intervention trial in a single ED. The control arm received standard care. The intervention arm received standard care plus pain advice from an independent investigator. All patients and treating ED staff were blinded to patient enrolment. Patient satisfaction with their pain management (six-point ordinal scale) was measured 48 h post-ED discharge, by a blinded researcher. The primary outcome was satisfaction with pain management.

Results

Of the 280 and 275 patients randomised to the control and intervention arms, respectively, 196 and 215 had complete data, respectively. 77.6% (152/196) and 88.8% (191/215) of patients reported being provided with pain advice, respectively (difference 11.3% (95% CI 3.6 to 19.0)). The intervention was associated with absolute and relative increases in patient satisfaction of 6.3% and 14.2%, respectively. 91.3% (179/196) and 76.3% (164/215) of patients who were/were not very satisfied reported having received ‘pain advice’ (difference 15.0% (95% CI 7.6 to 22.5)).

Conclusions

The intervention to provide pain advice resulted in a non-significant increase in patient satisfaction. A larger multicentre trial is feasible and is recommended to further explore the effects of provision of pain advice.

Trial registration number

ACTRN12615000097549.
Faecal biomarker patterns in patients with symptoms of irritable bowel syndrome
Authors: Emmanuel Anton , Landis Darryl , Peucker Mark , Hungin A Pali S
Published: March 2016

Objective

To determine rates of faecal biomarker results capable of suggesting potentially treatable causes of irritable bowel syndrome (IBS) symptomatology in a population of patients with symptoms of IBS who meet Rome III criteria for that condition.

Design

Descriptive, retrospective study in which faecal biomarker results (dichotomised into ‘normal’ and ‘abnormal’ values) were related to data from patient-completed questionnaire data identifying demographics, Rome III criteria for IBS and IBS phenotype (IBS-D, IBS-C, IBS-M and IBS-U).

Setting

Commercial reference laboratory.

Patients

Individuals whose physicians ordered faecal biomarker testing for evaluation of chronic abdominal symptoms consistent with IBS.

Interventions

None.

Main outcome measures

Rates of occurrence of abnormal results on any of seven faecal biomarkers suggesting a treatable cause for IBS symptoms.

Results

Abdominal symptoms meeting Rome III criteria for IBS were present in 3553 records (the population), which were subjected to further analysis. Abnormal biomarker results (the outcomes) occurred in 94% of cases; 73% and 65% of records indicated growth of a bacterial potential pathogen and low growth of beneficial organisms, respectively. Abnormal results for all other faecal biomarkers occurred with frequencies from 5% to 13%. Frequency of abnormal results for elastase, calprotectin, eosinophil protein X, and beneficial organisms rose significantly with age, and differed significantly across IBS phenotypes.

Conclusions

A large proportion of patients manifesting symptoms meeting Rome III IBS diagnostic criteria have faecal biomarker results indicating potential underlying, treatable causes of their symptoms. Faecal biomarker testing is an appropriate means of identifying potentially treatable causes of IBS symptoms.
Resting heart rate predicts incident myocardial infarction, atrial fibrillation, ischaemic stroke and death in the general population: the Tromsø Study
Authors: Sharashova Ekaterina , Wilsgaard Tom , Mathiesen Ellisiv B , Løchen Maja-Lisa , Njølstad Inger , Brenn Tormod
Published: March 2016

Background

Elevated resting heart rate (RHR) increases risk of death overall, but a comprehensive picture of the associations between RHR, cardiovascular morbidity and mortality events has not yet been presented. We aimed to investigate the effect of RHR on the risk of 5 cardiovascular events: incident myocardial infarction (MI), incident atrial fibrillation (AF), incident ischaemic stroke, total death and cardiovascular death in a general population from Norway.

Methods

We followed 24 489 men and women from the Tromsø Study 1994–1995, a population-based cohort study, for 18 years, and analysed the association between RHR and the investigated cardiovascular events. Sex-specific Cox regression with time-dependent covariates was applied with the best-fitting fractional polynomials of RHR.

Results

Among men, an independent positive relationship was observed for MI and AF (adjusted HR for AF per 20 bpm increase=1.14; 95% CI 1.02 to 1.27). In women, the corresponding HR for MI was 1.23 (1.09 to 1.40). A J-shaped association was observed for ischaemic stroke in women when compared with a RHR of 70 bpm (HR for 50 bpm=1.31; 0.90 to 1.90; HR for 100 bpm=1.32; 1.04 to 1.69). Total and cardiovascular death showed a strong positive association with RHR in men. In women, the pattern for total death was similar.

Conclusions

RHR is an independent risk factor for several cardiovascular events. A novel finding is the positive association between RHR and AF in men and the sex difference in association with ischaemic stroke.
Herbivory and advance reproduction influence quaking aspen regeneration response to management in southern Utah, USA
Authors: Britton Justin M. , DeRose R. Justin , Mock Karen E. , Long James N.
Published: March 2016

Recent concern regarding the potential decline of quaking aspen (Populus tremuloides Michx.) forests in the western United States has sparked concern over whether the species can be effectively regenerated. Using a retrospective approach, we quantified the response of regenerating aspen stems to an ordinary set of silvicultural treatments conducted over approximately the past decade in southern Utah, USA. A suite of variables describing stand structure and composition, stand vigor, physiographic factors, herbivore pressure, and treatment types were measured to predict the possible controls, as well as their relative importance, on aspen regeneration. Results suggested that aspen regeneration was most strongly related to browsing pressure, site preparation technique, and the presence of advance reproduction before treatment, which is a novel finding. Secondary predictors included elevation, site index, and overstory conditions, which are generally characteristics of stand vigor. Management recommendations based on our results should recognize the strong primary control that browsing pressure exerts on regeneration. First, the height of advance reproduction is inherently dependent on antecedent herbivory and also indicative of present browsing and should be assessed before treatment. Second, the most effective site preparation techniques, namely broadcast burning and browsing reduction, will directly reduce browsing pressure, assuming ungulate populations are not too large. Any management targeting timely and effective aspen regeneration should incorporate monitoring and (or) controlling browsing pressure, both before and after treatment.
Pair-production in polychromatic light oscillating electric fields
Authors: Song Xinfang , Wang Qiang , Fu Libin
Published: March 2016

Electron–positron pair-production process is observed in polychromatic light oscillating electric fields. A quantum kinetic theory is presented to obtain the pair-production rate and the momentum information. Oscillating structures of the particle yield and the odd–even structure of the momentum–frequency spectrum are depicted. The roles of the phase factor and the frequency multiplication are analyzed. We find the odd–even structures are remained in the triple-frequency field.
An Ultra-Low-Voltage Low-Power Current-Mode True RMS-to-DC Converter
Authors: Kompitaya Pantre , Kaewdang Khanittha
Published: March 2016

A current-mode CMOS true RMS-to-DC (RMS: root-mean-square) converter with very low voltage and low power is proposed in this paper. The design techniques are based on the implicit computation and translinear principle by using CMOS transistors that operate in the weak inversion region. The circuit can operate for two-quadrant input current with wide input dynamic range (0.4–500[Formula: see text]nA) with an error of less than 1%. Furthermore, its features are very low supply voltage (0.8[Formula: see text]V), very low power consumption ([Formula: see text]0.2[Formula: see text]nW) and low circuit complexity that is suitable for integrated circuits (ICs). The proposed circuit is designed using standard 0.18[Formula: see text][Formula: see text]m CMOS technology and the HSPICE simulation results show the high performance of the circuit and confirm the validity of the proposed design technique.
Boosting the Priority of Garbage
Authors: Akram Shoaib , Sartor Jennifer B. , Craeynest Kenzo Van , Heirman Wim , Eeckhout Lieven
Published: March 2016

While hardware is evolving toward heterogeneous multicore architectures, modern software applications are increasingly written in managed languages. Heterogeneity was born of a need to improve energy efficiency; however, we want the performance of our applications not to suffer from limited resources. How best to schedule managed language applications on a mix of big, out-of-order cores and small, in-order cores is an open question, complicated by the host of service threads that perform key tasks such as memory management. These service threads compete with the application for core and memory resources, and garbage collection (GC) must sometimes suspend the application if there is not enough memory available for allocation.

In this article, we explore concurrent garbage collection’s behavior, particularly when it becomes critical, and how to schedule it on a heterogeneous system to optimize application performance. While some applications see no difference in performance when GC threads are run on big versus small cores, others—those with
GC criticality
—see up to an 18% performance improvement. We develop a new, adaptive scheduling algorithm that responds to GC criticality signals from the managed runtime, giving more big-core cycles to the concurrent collector when it is under pressure and in danger of suspending the application. Our experimental results show that our GC-criticality-aware scheduler is robust across a range of heterogeneous architectures with different core counts and frequency scaling and across heap sizes. Our algorithm is performance and energy neutral for GC-uncritical Java applications and significantly speeds up GC-critical applications by 16%, on average, while being 20% more energy efficient for a heterogeneous multicore with three big cores and one small core.
UPDATE
Authors: Wang Yichuan , Liu Xin , Hsu Cheng-Hsin
Published: March 2016

Existing channel-aware scheduling work has mainly focused on scheduling in small timescales, that is, tens to hundreds of seconds. We propose to use long-term user profiles to provide useful statistical information on future network conditions in large timescales. We design scheduling algorithms based on Markov decision theory. We collect and use a large set of real-life traces from the general public. Extensive trace-driven evaluations show that many real mobile users can benefit from our framework. In addition, we compare our framework against state-of-the-art algorithms and observe significant performance differences because the existing algorithms were not designed for the large timescale scenario.
Evaluating the Design of a VLIW Processor for Real-Time Systems
Authors: Starke Renan Augusto , Carminati Andreu , Oliveira Rômulo Silva De
Published: March 2016

Nowadays, many real-time applications are very complex and as the complexity and the requirements of those systems become more demanding, more hardware processing capacity is necessary. Unfortunately, the correct functioning of real-time systems depends not only on the logically correct response but also on the time when it is produced. General-purpose processor design fails to deliver analyzability due to their nondeterministic behavior caused by the use of cache memories, dynamic branch prediction, speculative execution, and out-of-order pipelines. In this article, we investigate the pipeline performance of Very Long Instruction Word (VLIW) architectures for real-time systems with an in-order pipeline considering Worst-Case Execution Time (WCET) performance. Techniques on obtaining the WCET of VLIW machines are also considered and we make a quantification on how important are hardware techniques such as static branch prediction, predication, and pipeline speed of complex operations such as memory access and multiplication for high-performance real-time systems. The memory hierarchy is out of the scope of this article and we used a classic deterministic structure formed by a direct mapped instruction cache and a data scratchpad memory. A VLIW prototype was implemented in VHDL from scratch considering the HP VLIW ST231 ISA. We also show some compiler insights and we use a representative subset of the Mälardalen’s WCET benchmarks for validation and performance quantification.
R-GPU
Authors: Braak Gert-Jan Van Den , Corporaal Henk
Published: March 2016

Over the last decade, Graphics Processing Unit (GPU) architectures have evolved from a fixed-function graphics pipeline to a programmable, energy-efficient compute accelerator for massively parallel applications. The compute power arises from the GPU’s Single Instruction/Multiple Threads architecture: concurrently running many threads and executing them as Single Instruction/Multiple Data--style vectors. However, compute power is still lost due to cycles spent on data movement and control instructions instead of data computations. Even more cycles are lost on pipeline stalls resulting from long latency (memory) operations.

To improve not only performance but also energy efficiency, we introduce R-GPU: a reconfigurable GPU architecture with communicating cores. R-GPU is an addition to a GPU, which can still be used as such, but also has the ability to reorganize the cores of a GPU in a reconfigurable network. In R-GPU data movement and control is implicit in the configuration of the network. Each core executes a fixed instruction, reducing instruction decode count and increasing energy efficiency. On a number of benchmarks we show an average performance improvement of 2.1 × over the same GPU without modifications. We further make a conservative power estimation of R-GPU which shows that power consumption can be reduced by 6%, leading to an energy consumption reduction of 55%, while area only increases by a mere 4%.
The Quantum Anomalous Hall Effect: Theory and Experiment
Authors: Liu Chao-Xing , Zhang Shou-Cheng , Qi Xiao-Liang
Published: March 2016

The quantum anomalous Hall effect is defined as a quantized Hall effect realized in a system without an external magnetic field. The quantum anomalous Hall effect is a novel manifestation of topological structure in many-electron systems and may have potential applications in future electronic devices. In recent years, the quantum anomalous Hall effect was proposed theoretically and realized experimentally. In this review article, we provide a systematic overview of the theoretical and experimental developments in this field.