bluuebunny/crossref_metadata_2025 huggingface dataset:
Stability Analysis of a Whirling Rigid Rotor Supported by FDBs Considering Five Degrees of Freedom of a General Rotor-Bearing System
Authors: Lee M. H. , Lee J. H. , Jang G. H.
Published: August 2014

A rotor supported by fluid dynamic bearings (FDBs) has a whirling motion by centrifugal force due to the mass unbalance or by the flexibility of shaft. This whirling motion also generates periodic time-varying oil-film reaction and dynamic coefficients even in case of the stationary grooved FDBs.

This paper proposes a method to determine the stability of a whirling rotor supported by stationary grooved FDBs considering five degrees of freedom of a general rotor-bearing system. Dynamic coefficients are calculated by using the finite element method and the perturbation method, and they are represented as periodic harmonic functions by considering whirling motion. Because of the periodic time-varying dynamic coefficients, the equations of motion of the rotor supported by FDBs can be represented as a parametrically excited system. The solution of the equations of motion can be assumed as the Fourier series so that the equations of motion can be rewritten as simultaneous algebraic equations with respect to the Fourier coefficients. Hill’s infinite determinant is calculated by using these algebraic equations in order to determine the stability.

The stability of the FDBs decreases with the increase of rotational speed. The stability of the FDBs increases with the increase of whirl radius, because the average and variation of Cxx increase faster than those of Kxx. The proposed method is verified by solving the equations of motion by using the forth Runge-Kutta method to determine the convergence and divergence of whirl radius.
Low SNR Signal Processing for Head Media Contact Detection in HDD
Authors: Daugela Antanas , Tadepalli Srinivas
Published: August 2014

The methodology for processing grossly undersampled HDD position error signal (PES) is proposed to improve the head-disk contact detection process. The proposed method is a combination of compressive sampling (CS) and adaptive discrete wavelet transform (ADWT) techniques. Here, CS is employed to reconstruct the PES information from very few revolutions of data while ADWT is utilized for extracting head-disk interface (HDI) modulation changes during thermal protrusion of the read/write element.
Model Acquisition for Modal Analysis of Flexible Media Based on Stereo Vision
Authors: Chang Yen-Hao , Chang Jen-Yuan (James)
Published: August 2014

To enhance and ensure machine reliability and accuracy, obtaining its mechanical properties in real-time dynamic conditions is of engineering importance. In both roll to roll printing and metal sheet rolling processes, it is well known that any misalignment or orientation arrangement between rollers can significant change stress distribution in the high speed transporting flexible media, leading to quite different dynamic responses in the manufacturing process. In sheet metal manufacturing process, to eliminate residual in the flexible media, it is a common process to place two adjacent rollers at different orientations and location, causing the media to deform largely and even to twist. In this case, common non-contact vibration measurement method using either single point or scanning laser Doppler vibrometry cannot accurately capture the vibratory response from the media due to the significant change in geometry to scatter the reflective laser light. In this paper, instead of adjusting the laser perpendicular to the curved surface of the media at each measurement point to capture modal information through experimental modal analysis, which is achieved by utilizing the excitation and measurement apparatuses to directly discover the modes of the media, a novel non-contact measurement method is proposed by using stereo vision to first acquire the shape of the flexible homogeneous metal sheet through one camera with a fixed focal length from two different views, and then calculate the coordinate by computer vision algorithm. The calculated coordinates and shape information will be input to the commercial FEA software and compute its modal information, namely natural frequencies and mode shapes. Lastly, the results gained by the method proposed will be compared with that acquired directly by the experimental methods.
Operational Shock Response of Ultrathin Hard Disk Drives
Authors: Yu Shengkai , Mou Jianqiang , Hua Wei , Zhou Weidong , Tan Chye Chin
Published: August 2014

Operational shock is one of key challenges for designing the ultrathin mobile hard disk drives (HDDs) due to the reduced thickness of mechanical components and their stiffness. Some simplifications in the conventional methods for operational shock simulation are not valid. In this paper, a method for system level modelling and simulation of operational shock response of HDDs has been proposed by coupling the structural finite element model of the HDD and the air bearing model. The dynamic shock response of the head-disk system in a 5 mm ultrathin HDD design is investigated. The effects of drive base stiffness, disk-ramp contact, disk spinning and disk distortion have been studied. The results reveal that the drive base deformation and ramp contact are critical for the operational shock resistance performance of ultrathin drives.
A New Prediction Model on the Luminance of OLEDs Subjected to Different Reverse Biases for Alleviating Degradation in AMOLED Displays
Authors: Chao Paul C.-P. , Hsu Yen-Ping , Kao Yung-Hua , Lee Kuei-Yu
Published: August 2014

Organic light-emitting diodes (OLEDs) have drawn much attention in areas of displays and varied illumination devices due to multiple advantages, such as high brightness, high efficiency, wide viewing angle, and simple structure. However, the long-time degradation of OLED emission is a serious drawback. This degradation was investigated by past works, which pointed out that the degradation was induced by high-density currents through OLED component under the long-time operation [1][2]. Proposed by a past work [3], different reverse biases was imposed on OLED components in display frames to alleviate the long-time degradation on OLEDs. Most recently, along with the reverse bias, new pixel circuits [4][5] for AMOLED displays are designed to alleviate OLED degradation, thus successfully extending OLED life time. However, since emission luminances in different frame times during AMOLED displaying differs significantly for displaying varied images, the OLED degradation evolves in a highly unpredictable fashion. In this study, based on valid theories, the voltage across the OLED is first used as indicator for OLED degradation. Then the relation between the level of OLED degradation, in terms of OLED’s cross voltage, and the history of imposing reverse biases are precisely modeled. With the model, the degradation of the OLED under reverse bias to extend lifetime can be successfully predicted. Based on this model, engineers can then optimize the applied reverse bias on OLEDs to maximize the OLED lifetime for varied display requirement.
A New Method for Calibrating a Six-DOF Joint Force/Torque Sensor
Authors: Hieu Tran Trong , Chao Paul C.-P. , Wang Yu-Jen , Wang Chun-Chieh
Published: August 2014

One of the main senses that humans use to interact with their environment is the sense of touch and this is currently the major aim of many research projects of robots in varied forms. The measurement of the multi-dimension interactive force between the human hand and interaction device such as hand-controllers, joysticks, limb rehabilitation devices, etc., becomes important components. Encoders are installed in each joint for position-sensing feedbacks while tactile sensors are often installed at the fingertip of a hand to detect contacts [1][2][3][4]. There have been varied sensor structures, one of which is shown in Fig. 1 [5]. The method of structure design used in Song’s research [5] is for a 4-degree-of-freedom (DOF) force/torque sensor. The resulted error is larger than 1%. Although it is better than the error from commercial 6-DOF force/torque sensors, the error of 1% is still unsatisfactory for some applications, especially for precision robots.
Experimental Study of the Resonances of the Slider Modulations by Laser Doppler Vibrometer
Authors: Peng Peng , Ramakrishnan Narayanan , Kumar Vijay , Karr Brian
Published: August 2014

The magnetic spacing of Hard Disk Drives (HDD) needs to be reduced for increasing areal density. It is therefore very challenging to maintain constant fly height at a sub-2nm clearance. Any resonance of the slider or suspension can cause modulations on fly height and thus impacting the writing efficiency. Various research was carried out for the flying stability of the slider [1–4], especially in the off-track direction caused by voice coil motor (VCM) as well as PZT actuation. However, the resonances of the slider modulations in vertical direction have not been well researched. In the study, a method of using heater oscillation to examine the slider resonances has been proposed. The experiments have been performed on two suspension designs and two air bearing designs to demonstrate the effectiveness of this approach. The experimental results showed a shift of resonance frequencies due to a design change of the suspension. The air bearing design also played a role in the heater time constant and thus affecting the magnitude of resonances. Further, larger resonances were observed in a lower clearance setting than passive fly.
Contact Modeling of Traveling Wave Ultrasonic Motors
Authors: Shen Shengnan , Li Hui , Cui Fuhao , Zhang Guoqing , Dai Xiangyu
Published: August 2014

In the pursuit of high areal recording density towards 10 Tb/in2, it is necessary to improve the positioning accuracy of the magnetic head in the hard disk drive head-positioning control system. Ultrasonic motors (USMs) are novel electric motors used for positioning controls. Due to the drive characteristic of USMs, wear and fatigue of friction material at the contact friction interface are inevitable. Contact deformation can cause local damage of USMs. Therefore, obtaining the details of the stress distribution in the friction material due to the inelastic deformation is important. In this work, a contact model of traveling wave ultrasonic motor (TWUSM) is proposed. A three dimensional finite element model with cohesive zone elements embedded between friction material and rotor is then developed. Infinite finite elements are incorporated in this modeling as the boundary condition as the model thickness is typically many orders smaller than the longitudinal dimension. The evolution of deformation in friction material and rotor due to the mechanical surface loading is presented. The possible interfacial delamination process between friction material and rotor is numerically studied. And the friction coefficient effect of the friction material on the delamination propagation is also investigated.
An Experimental Study of the Fretting Wear Coefficient for the Dimple-Gimbal Interface
Authors: Tang Zhengqiang , Talke Frank E.
Published: August 2014

The effect of normal load on fretting wear of the dimple-gimbal interface is investigated. The wear volume, the wear coefficient and the friction-displacement loops are studied as a function of the number of fretting wear cycles. The wear volume of the dimple is calculated from the radius of the wear scar obtained using scanning electron microscopy. The results show that the wear coefficient decreases with an increase in the number of fretting wear cycles.
Design of a Collocated Dual Stage Suspension in a Hard Disk Drive
Authors: Li Longqiu , Morris Karcher , Hogan John , Talke Frank E.
Published: August 2014

The design of a collocated head-based dual stage actuator is investigated using finite element analysis. The effect of gimbal design dimensions on the lateral deflection is evaluated. Comparison of the present dual stage head-based actuator is made with other suspension-based designs and the collocated design proposed by Lengert et al [1].
Robust Hub Design to Prevent Mechanical Contact Between Hub and Sleeve of the FDBs in a 2.5″ HDD With 5mm-Height due to Disc Clamping Force
Authors: Kim B. C. , Jang G. H.
Published: August 2014

In slim 2.5″ HDDs with 5mm or 7mm-height, the mechanical structure has to be simplified and all of the axial dimensions have to be miniaturized. It results in too flexible HDDs which is vulnerable to external force Especially, the rotating hub is so thin and flexible to make contact with stationary sleeve by clamping force.

In this paper, we investigated the mechanical contact between the rotating hub and stationary sleeve of a 2.5″ HDD with 5 mm-height at low rotating speed. And we checked upper thrust surface in hub and sleeve after tearing down the FDBs. Circumferential scratch is observed on the upper thrust surface of sleeve and hub due to mechanical contact. Hub deflection due to disc clamping force was identified as a source of mechanical contact between rotating hub and stationary sleeve. To prevent mechanical contact between them, we proposed a robust design of hub and validated the proposed design theoretically and experimentally.
In-Situ Contact Potential Measurement in Hard Disk Drives Using Head Disk Interface Voltage Control
Authors: Murthy Aravind N. , Pit Remmelt , Flechsig Karl A.
Published: August 2014

There is an inherent contact potential difference between the head and the disk surfaces in hard disk drives (HDD’s). Current HDD’s use thermal fly-height control (TFC) during read/write operations. In this study, we show a method to determine the contact potential for the head disk interface (HDI) using TFC technology. We utilize TFC to measure the flying height of the slider via touchdown power by applying a DC voltage bias to either the head or the disk or both. The DC voltage condition where the TFC clearance is maximized corresponds to the balancing of the HDI contact potential. In other words, the opposite polarity of that DC voltage bias condition is the HDI contact potential. Additionally, we show that the contact potential of HDI can be determined by either applying the DC voltage bias to the head or to the disk.
Comparison of internal dose estimates obtained using organ‐level, voxel S value, and Monte Carlo techniques
Authors: Grimes Joshua , Celler Anna
Published: August 2014

Purpose:

The authors’ objective was to compare internal dose estimates obtained using the Organ Level Dose Assessment with Exponential Modeling (OLINDA/EXM) software, the voxel S value technique, and Monte Carlo simulation. Monte Carlo dose estimates were used as the reference standard to assess the impact of patient‐specific anatomy on the final dose estimate.

Methods:

Six patients injected with99mTc‐hydrazinonicotinamide‐Tyr3‐octreotide were included in this study. A hybrid planar/SPECT imaging protocol was used to estimate 99mTc time‐integrated activity coefficients (TIACs) for kidneys, liver, spleen, and tumors. Additionally, TIACs were predicted for 131I, 177Lu, and 90Y assuming the same biological half‐lives as the 99mTc labeled tracer. The TIACs were used as input for OLINDA/EXM for organ‐level dose calculation and voxel level dosimetry was performed using the voxel S value method and Monte Carlo simulation. Dose estimates for 99mTc, 131I, 177Lu, and 90Y distributions were evaluated by comparing (i) organ‐level S values corresponding to each method, (ii) total tumor and organ doses, (iii) differences in right and left kidney doses, and (iv) voxelized dose distributions calculated by Monte Carlo and the voxel S value technique.

Results:

The S values for all investigated radionuclides used by OLINDA/EXM and the corresponding patient‐specific S values calculated by Monte Carlo agreed within 2.3% on average for self‐irradiation, and differed by as much as 105% for cross‐organ irradiation. Total organ doses calculated by OLINDA/EXM and the voxel S value technique agreed with Monte Carlo results within approximately ±7%. Differences between right and left kidney doses determined by Monte Carlo were as high as 73%. Comparison of the Monte Carlo and voxel S value dose distributions showed that each method produced similar dose volume histograms with a minimum dose covering 90% of the volume (D90) agreeing within ±3%, on average.

Conclusions:

Several aspects of OLINDA/EXM dose calculation were compared with patient‐specific dose estimates obtained using Monte Carlo. Differences in patient anatomy led to large differences in cross‐organ doses. However, total organ doses were still in good agreement since most of the deposited dose is due to self‐irradiation. Comparison of voxelized doses calculated by Monte Carlo and the voxel S value technique showed that the 3D dose distributions produced by the respective methods are nearly identical.
Oxygen Cost of Recreational Horse-Riding in Females
Authors: Beale Louisa , Maxwell Neil S , Gibson Oliver R , Twomey Rosemary , Taylor Becky , Church Andrew
Published: August 2014

Background:

The purpose of this study was to characterize the physiological demands of a riding session comprising different types of recreational horse riding in females.

Methods:

Sixteen female recreational riders (aged 17 to 54 years) completed an incremental cycle ergometer exercise test to determine peak oxygen consumption (VO2peak) and a 45-minute riding session based upon a British Horse Society Stage 2 riding lesson (including walking, trotting, cantering and work without stirrups). Oxygen consumption (VO2), from which metabolic equivalent (MET) and energy expenditure values were derived, was measured throughout.

Results:

The mean VO2 requirement for trotting/cantering (18.4 ± 5.1 ml·kg-1·min-1; 52 ± 12% VO2peak; 5.3 ± 1.1 METs) was similar to walking/trotting (17.4 ± 5.1 ml·kg-1·min-1; 48 ± 13% VO2peak; 5.0 ± 1.5 METs) and significantly higher than for work without stirrups (14.2 ± 2.9 ml·kg-1·min-1; 41 ± 12% VO2peak; 4.2 ± 0.8 METs) (P = .001).

Conclusion:

The oxygen cost of different activities typically performed in a recreational horse riding session meets the criteria for moderate intensity exercise (3-6 METs) in females, and trotting combined with cantering imposes the highest metabolic demand. Regular riding could contribute to the achievement of the public health recommendations for physical activity in this population.
Aerobic Fitness Indices of Children Differed Not by Body Weight Status but by Level of Engagement in Physical Activity
Authors: Jabbour Georges , Henderson Melanie , Tremblay Angelo , Mathieu Marie Eve
Published: August 2014

Objective:

Moderate-to-vigorous physical activity (MVPA) improves aerobic fitness in children, which is usually assessed by maximal oxygen consumption. However, other indices of aerobic fitness have been understudied.

Methods:

To compare net oxygen (VO2net), net energy consumption (Enet), net mechanical efficiency (MEnet), and lipid oxidation rate in active and inactive children across body weight statuses.

Design:

The sample included normal-weight, overweight, and obese children of whom 44 are active (≥30 min of MVPA/d) and 41 are inactive (<30 min of MVPA/d). VO2net, Enet, MEnet and lipid oxidation rate were determined during an incremental maximal cycling test.

Results:

Active obese participants had significantly lower values of VO2net and Enet and higher MEnet than inactive obese participants at all load stages. In addition, active obese participants showed a significantly higher lipid oxidation rate compared with inactive obese and active overweight and normal-weight participants. VO2net, Enet, and MEnet were similar across active children, regardless of body weight status.

Conclusion:

Thirty minutes or more of MVPA per day is associated with a potentiation of aerobic fitness indicators in obese prepubertal children. Moreover, the indices of aerobic fitness of inactive obese children are significantly different from those of active obese and nonobese ones.
Examining the Relationship Between Physical Activity Intensity and Adiposity in Young Women
Authors: Bailey Bruce W. , Borup Pamela , LeCheminant James D. , Tucker Larry A. , Bromley Jacob
Published: August 2014

Background:

The purpose of this study was to assess the relationship between intensity of physical activity (PA) and body composition in 343 young women.

Methods:

Physical activity was objectively measured using accelerometers worn for 7 days in women 17 to 25 years. Body composition was assessed using the BOD POD.

Results:

Young women who spent less than 30 minutes a week performing vigorous PA had significantly higher body fat percentages than women who performed more than 30 minutes of vigorous PA per week (F = 4.54, P = .0113). Young women who spent less than 30 minutes per day in moderate to vigorous PA (MVPA) had significantly higher body fat percentages than those who obtained more than 30 minutes per day of MVPA (F = 7.47, P = .0066). Accumulating more than 90 minutes of MVPA per day was associated with the lowest percent body fat. For every 10 minutes spent in MVPA per day, the odds of having a body fat percentage above 32% decreased by 29% (P = .0002).

Conclusion:

Vigorous PA and MVPA are associated with lower adiposity. Young women should be encouraged to accumulate at least 30 minutes of MVPA per day, however getting more than 90 minutes a day is predictive of even lower levels of adiposity.
Whole-Genome Sequence of a Multidrug-Resistant Mycobacterium tuberculosis Beijing Sequence Type 10 Isolate from an Outbreak in Thailand
Authors: Coker Olabisi O. , Regmi Sanjib M. , Suriyaphol Prapat , Chininmanu Kwanrutai , Prammananan Therdsak , Chaiprasert Angkana
Published: August 2014

Infections with the Beijing family of
Mycobacterium tuberculosis
occur worldwide and are endemic in Asian countries. We present the draft genome sequence of DS6701, a multidrug-resistant
M. tuberculosis
Beijing strain of sequence type 10. The isolate is a representative of strains isolated from a multidrug-resistant tuberculosis outbreak in Thailand.
Draft Genome Sequence of an Atypical Strain of Streptococcus pneumoniae Isolated from a Respiratory Infection
Authors: Choi Sang Chul , Parker Jayme , Richards Vincent P. , Ross Katherine , Jilly Bernard , Chen Jack
Published: August 2014

Next-generation sequencing was used to investigate an unknown clinical respiratory infection. This new strain of
Streptococcus pneumoniae
, ASVL_JC_0001, was isolated from a clinical specimen from a patient with bronchitis and pulmonary inflammation. The draft genome sequence, obtained with an Illumina MiSeq sequencing system, consists of 83 large contigs, a total of 2,092,532 bp long, and has a GC content of 40.3%.
Transforming consumer health informatics through a patient work framework: connecting patients to context
Authors: Valdez Rupa S , Holden Richard J , Novak Laurie L , Veinot Tiffany C
Published: August 2014

Designing patient-centered consumer health informatics (CHI) applications requires understanding and creating alignment with patients’ and their family members’ health-related activities, referred to here as ‘patient work’. A patient work approach to CHI draws on medical social science and human factors engineering models and simultaneously attends to patients, their family members, activities, and context. A patient work approach extends existing approaches to CHI design that are responsive to patients’ biomedical realities and personal skills and behaviors. It focuses on the embeddedness of patients’ health management in larger processes and contexts and prioritizes patients’ perspectives on illness management. Future research is required to advance (1) theories of patient work, (2) methods for assessing patient work, and (3) techniques for translating knowledge of patient work into CHI application design. Advancing a patient work approach within CHI is integral to developing and deploying consumer-facing technologies that are integrated with patients’ everyday lives.
Unsuitability of the epidemiological approach to bicycle transportation injuries and traffic engineering problems
Authors: Kary M
Published: August 2014

Bicyclists and transportation professionals would do better to decline advice drawn from characteristically epidemiological studies. The faults of epidemiology are both accidental (unpreparedness for the task) and essential (unsuitability of the methods). Characteristically epidemiological methods are known to be error-prone, and when applied to bicycle transportation suffer from diversion bias, inappropriately broad-brush categorisations, a focus on undifferentiated risk rather than on danger, a bias towards unsafe behaviour, and an overly narrow perspective. To the extent that there is a role for characteristically epidemiological methods, it should be the same as anywhere else: as a preliminary or adjunct to the scientific method, for which there is no substitute.
What does your neighbourhood say about you? A study of life expectancy in 1.3 million Swiss neighbourhoods
Authors: Moser André , Panczak Radoslaw , Zwahlen Marcel , Clough-Gorr Kerri M , Spoerri Adrian , Stuck Andreas E , Egger Matthias
Published: August 2014

Background

Switzerland had the highest life expectancy at 82.8 years among the Organisation for Economic Co-operation and Development (OECD) countries in 2011. Geographical variation of life expectancy and its relation to the socioeconomic position of neighbourhoods are, however, not well understood.

Methods

We analysed the Swiss National Cohort, which linked the 2000 census with mortality records 2000–2008 to estimate life expectancy across neighbourhoods. A neighbourhood index of socioeconomic position (SEP) based on the median rent, education and occupation of household heads and crowding was calculated for 1.3 million overlapping neighbourhoods of 50 households. We used skew-normal regression models, including the index and additionally marital status, education, nationality, religion and occupation to calculate crude and adjusted estimates of life expectancy at age 30 years.

Results

Based on over 4.5 million individuals and over 400 000 deaths, estimates of life expectancy at age 30 in neighbourhoods ranged from 46.9 to 54.2 years in men and from 53.5 to 57.2 years in women. The correlation between life expectancy and neighbourhood SEP was strong (r=0.95 in men and r=0.94 women, both p values <0.0001). In a comparison of the lowest with the highest percentile of neighbourhood SEP, the crude difference in life expectancy from skew-normal regression was 4.5 years in men and 2.5 years in women. The corresponding adjusted differences were 2.8 and 1.9 years, respectively (all p values <0.0001).

Conclusions

Although life expectancy is high in Switzerland, there is substantial geographical variation and life expectancy is strongly associated with the social standing of neighbourhoods.
A pilot study of angiotensin converting enzyme (ACE) genotype and return of spontaneous circulation following out-of-hospital cardiac arrest
Authors: Lindner Thomas W , Deakin Charles D , Aarsetøy Hildegunn , Rubertsson Sten , Heltne Jon-Kenneth , Søreide Eldar
Published: August 2014

Objective

In the last few years the genetic influence on health and disease outcome has become more apparent. The ACE genotype appears to play a significant role in the pathophysiology of several disease processes. This pilot study aims at showing the feasibility to examine the genetic influence of the ACE genotype on return of spontaneous circulation (ROSC) in out-of-hospital cardiac arrest (OHCA).

Methods

We performed a prospective observational study of all OHCAs of presumed cardiac origin in a well-defined population. We collected prehospital blood samples for the determination of ACE genotype and used this information together with Utstein template parameters in a multivariable analysis to examine the relationship between ROSC and ACE genotype.

Results

We collect blood samples in 156 of 361 patients with OHCA of presumed cardiac origin, 127 samples were analysed (mean age 67 years, 86% male, 79% witnessed OHCA, 80% bystander CPR, 62% had a shockable rhythm, ROSC 77%). Distribution of the ACE gene polymorphisms: insertion polymorphism (II) n=22, 17%, insertion/deletion polymorphism (ID) n=66, 52% and deletion polymorphism (DD) n=39, 31%. We found no significant association between ACE II vs ACE DD/DI and ROSC (OR 1.72; CI 0.52 to 5.73; p=0.38). Other ACE genotype groupings (II/ID vs DD or II vs DD) did not change the overall finding of lack of impact of ACE genotype on ROSC.

Conclusions

This pilot study did not indicate a significant association between ACE gene polymorphism and ROSC. However, it has demonstrated that prehospital genetic studies including blood sampling are feasible and ethically acceptable.
Label propagation algorithm based on edge clustering coefficient for community detection in complex networks
Authors: Zhang Xian-Kun , Tian Xue , Li Ya-Nan , Song Chen
Published: August 2014

The label propagation algorithm (LPA) is a graph-based semi-supervised learning algorithm, which can predict the information of unlabeled nodes by a few of labeled nodes. It is a community detection method in the field of complex networks. This algorithm is easy to implement with low complexity and the effect is remarkable. It is widely applied in various fields. However, the randomness of the label propagation leads to the poor robustness of the algorithm, and the classification result is unstable. This paper proposes a LPA based on edge clustering coefficient. The node in the network selects a neighbor node whose edge clustering coefficient is the highest to update the label of node rather than a random neighbor node, so that we can effectively restrain the random spread of the label. The experimental results show that the LPA based on edge clustering coefficient has made improvement in the stability and accuracy of the algorithm.
Mitochondrial depolarization and electrophysiological changes during ischemia in the rabbit and human heart
Authors: Sulkin Matthew S. , Boukens Bas J. , Tetlow Megan , Gutbrod Sarah R. , Ng Fu Siong , Efimov Igor R.
Published: August 2014

Instability of the inner mitochondrial membrane potential (ΔΨm) has been implicated in electrical dysfunction, including arrhythmogenesis during ischemia-reperfusion. Monitoring ΔΨm has led to conflicting results, where depolarization has been reported as sporadic and as a propagating wave. The present study was designed to resolve the aforementioned difference and determine the unknown relationship between ΔΨm and electrophysiology. We developed a novel imaging modality for simultaneous optical mapping of ΔΨm and transmembrane potential ( Vm). Optical mapping was performed using potentiometric dyes on preparations from 4 mouse hearts, 14 rabbit hearts, and 7 human hearts. Our data showed that during ischemia, ΔΨm depolarization is sporadic and changes asynchronously with electrophysiological changes. Spatially, ΔΨm depolarization was associated with action potential duration shortening but not conduction slowing. Analysis of focal activity indicated that ΔΨm is not different within the myocardium where the focus originates compared with normal ventricular tissue. Overall, our data suggest that during ischemia, mitochondria maintain their function at the expense of sarcolemmal electrophysiology, but ΔΨm depolarization does not have a direct association to ischemia-induced arrhythmias.
NQO1 Suppresses NF-κB–p300 Interaction to Regulate Inflammatory Mediators Associated with Prostate Tumorigenesis
Authors: Thapa Dinesh , Meng Peng , Bedolla Roble G. , Reddick Robert L. , Kumar Addanki P. , Ghosh Rita
Published: August 2014

NADPH reductase NAD(P)H:quinone oxidoreductase 1 (NQO1) is needed to maintain a cellular pool of antioxidants, and this enzyme may contribute to tumorigenesis on the basis of studies in NQO1-deficient mice. In this work, we sought deeper insights into how NQO1 contributes to prostate carcinogenesis, a setting in which oxidative stress and inflammation are established contributors to disease development and progression. In the TRAMP mouse model of prostate cancer, NQO1 was highly expressed in tumor cells. NQO1 silencing in prostate cancer cells increased levels of nuclear IKKα and NF-κB while decreasing the levels of p53, leading to interactions between NF-κB and p300 that reinforce survival signaling. Gene expression analysis revealed upregulation of a set of immune-associated transcripts associated with inflammation and tumorigenesis in cells in which NQO1 was attenuated, with IL8 confirmed functionally in cell culture as one key NQO1-supported cytokine. Notably, NQO1-silenced prostate cancer cells were more resistant to androgen deprivation. Furthermore, NQO1 inhibition increased migration, including under conditions of androgen deprivation. These results reveal a molecular link between NQO1 expression and proinflammatory cytokine signaling in prostate cancer. Furthermore, our results suggest that altering redox homeostasis through NQO1 inhibition might promote androgen-independent cell survival via opposing effects on NF-κB and p53 function. Cancer Res; 74(19); 5644–55. ©2014 AACR.
AXL Inhibition Sensitizes Mesenchymal Cancer Cells to Antimitotic Drugs
Authors: Wilson Catherine , Ye Xiaofen , Pham Thinh , Lin Eva , Chan Sara , McNamara Erin , Neve Richard M. , Belmont Lisa , Koeppen Hartmut , Yauch Robert L. , Ashkenazi Avi , Settleman Jeff
Published: August 2014

Molecularly targeted drug therapies have revolutionized cancer treatment; however, resistance remains a major limitation to their overall efficacy. Epithelial-to-mesenchymal transition (EMT) has been linked to acquired resistance to tyrosine kinase inhibitors (TKI), independent of mutational resistance mechanisms. AXL is a receptor tyrosine kinase associated with EMT that has been implicated in drug resistance and has emerged as a candidate therapeutic target. Across 643 human cancer cell lines that were analyzed, elevated AXL was strongly associated with a mesenchymal phenotype, particularly in triple-negative breast cancer and non–small cell lung cancer. In an unbiased screen of small-molecule inhibitors of cancer-relevant processes, we discovered that AXL inhibition was specifically synergistic with antimitotic agents in killing cancer cells that had undergone EMT and demonstrated associated TKI resistance. However, we did not find that AXL inhibition alone could overcome acquired resistance to EGFR TKIs in the EMT setting, as previously reported. These findings reveal a novel cotreatment strategy for tumors displaying mesenchymal features that otherwise render them treatment refractory. Cancer Res; 74(20); 5878–90. ©2014 AACR.
A Recombinant Modified Vaccinia Ankara Vaccine Encoding Epstein–Barr Virus (EBV) Target Antigens: A Phase I Trial in UK Patients with EBV-Positive Cancer
Authors: Taylor Graham S. , Jia Hui , Harrington Kevin , Lee Lip Wai , Turner James , Ladell Kristin , Price David A. , Tanday Manjit , Matthews Jen , Roberts Claudia , Edwards Ceri , McGuigan Lesley , Hartley Andrew , Wilson Steve , Hui Edwin P. , Chan Anthony T. C. , Rickinson Alan B. , Steven Neil M.
Published: August 2014

Purpose: Epstein–Barr virus (EBV) is associated with several cancers in which the tumor cells express EBV antigens EBNA1 and LMP2. A therapeutic vaccine comprising a recombinant vaccinia virus, MVA-EL, was designed to boost immunity to these tumor antigens. A phase I trial was conducted to demonstrate the safety and immunogenicity of MVA-EL across a range of doses.

Experimental Design: Sixteen patients in the United Kingdom (UK) with EBV-positive nasopharyngeal carcinoma (NPC) received three intradermal vaccinations of MVA-EL at 3-weekly intervals at dose levels between 5 × 107 and 5 × 108 plaque-forming units (pfu). Blood samples were taken at screening, after each vaccine cycle, and during the post-vaccination period. T-cell responses were measured using IFNγ ELISpot assays with overlapping EBNA1/LMP2 peptide mixes or HLA-matched epitope peptides. Polychromatic flow cytometry was used to characterize functionally responsive T-cell populations.

Results: Vaccination was generally well tolerated. Immunity increased after vaccination to at least one antigen in 8 of 14 patients (7/14, EBNA1; 6/14, LMP2), including recognition of epitopes that vary between EBV strains associated with different ethnic groups. Immunophenotypic analysis revealed that vaccination induced differentiation and functional diversification of responsive T-cell populations specific for EBNA1 and LMP2 within the CD4 and CD8 compartments, respectively.

Conclusions: MVA-EL is safe and immunogenic across diverse ethnicities and thus suitable for use in trials against different EBV-positive cancers globally as well as in South-East Asia where NPC is most common. The highest dose (5 × 108 pfu) is recommended for investigation in current phase IB and II trials. Clin Cancer Res; 20(19); 5009–22. ©2014 AACR.
Low Levels of Low-Density Lipoprotein-C Associated With Proprotein Convertase Subtilisin Kexin 9 Inhibition Do Not Increase the Risk of Hemorrhagic Transformation
Authors: Tran-Dinh Alexy , Levoye Angélique , Lambert Gilles , Louedec Liliane , Journé Clément , Meilhac Olivier , Amarenco Pierre
Published: August 2014

Background and Purpose—

Low levels of low-density lipoprotein-cholesterol (LDL-C) are suspected to be associated with a risk of hemorrhagic transformation after ischemic stroke. We assessed the risk of hemorrhagic transformation after cerebral ischemia/reperfusion in mice with low levels of LDL-C resulting from proprotein convertase subtilisin kexin 9 (PCSK9) deficiency.

Methods—

PCSK9
−/−
and PCSK9
+/+
mice were fed with a high-fat/high-cholesterol (21%/0.15%) diet for 1 month. Plasma lipids were measured using colorimetric assays. PCSK9
−/−
and PCSK9
+/+
mice (n=15 per group) were subjected to a 4-hour intraluminal occlusion of the middle cerebral artery followed by 20 hours of reperfusion. Spontaneous hemorrhagic transformation was assessed by quantification of hemoglobin in ischemic tissue. In vitro, a cell model of blood–brain barrier was used to test endothelial barrier integrity in response to decreasing concentrations of LDL-C from 1 to 0.25g/L in ischemia/reperfusion conditions.

Results—

PCSK9
−/−
mice had lower LDL-C, high-density lipoprotein-cholesterol, and total cholesterol levels than PCSK9
+/+
mice before and after 1 month on the high-fat/high-cholesterol diet. Hemoglobin concentration in ischemic cerebral tissue was not different between PCSK9
−/−
and PCSK9
+/+
mice (31.5 [18.9–60.1] and 32.8 [14.7–69.9] ng/mg protein, respectively;
P
=0.81). Infarct volume was also similar in both groups (
P
=0.66). Incubation of human cerebral endothelial cells with decreasing concentrations of LDL-C under ischemia/reperfusion conditions did not alter blood–brain barrier permeability.

Conclusions—

Low levels of LDL-C did not increase the risk of hemorrhagic transformation after cerebral ischemia/reperfusion in mice. Our observations suggest that PCSK9 inhibition, leading to LDL-C lowering, should not increase hemorrhagic complications after acute ischemic stroke.
Additional slipper lobsters of the subfamily Scyllarinae Latreille, 1825 (Crustacea, Achelata, Scyllaridae) from Taiwan
Authors: YANG CHIEN-HUI , LIN CHIA-WEI , CHAN TIN-YAM
Published: August 2014

Five scyllarine lobsters are recorded from Taiwan for the first time. They are Bathyarctus rubens (Alcock & Anderson, 1894), Biarctus sordidus (Stimpson, 1860), Chelarctus aureus (Holthuis, 1963), Crenarctus bicuspidatus (De Man, 1905) and Petrarctus veliger Holthuis, 2002. The distributions of B. rubens, C. aureus and P. veliger are extended northwards to Taiwan. Distinguishing characters of these five species are illustrated and color photographs of all but B. sordidus are provided. Altogether, nine genera and 17 species of scyllarine lobsters are now known from Taiwan.
Lamprologus markerti, a new lamprologine cichlid (Teleostei: Cichlidae) endemic to the lower Congo River in the Democratic Republic of Congo, west-central Africa
Authors: TOUGAS STEPHANIE , STIASSNY MELANIE L.J.
Published: August 2014

A new Lamprologus is described from the lower Congo River (LCR) in the Democratic Republic of Congo. Lamprologus markerti, new species, is readily distinguished from L. tigripictilis and L. werneri, the LCR endemic lamprologines with which it was once taxonomically conflated, in the possession of a reduced number of gill rakers on the first arch (9–11 versus 12–17), a longer head (32.1–34.7% SL versus 29.3–31.9 and 29.1–32.9% SL, respectively), and a longer predorsal length (33.0–35.9% SL versus 29.3–32.7 and 28.5–32.6% SL, respectively). Further, L. markerti lacks a second intestinal loop present in both L. tigripictilis and L. werneri, and has a highly reduced infraorbital series often consisting of a single first infraorbital (lachrymal) element.
Influence of Liquid Water Content and Temperature on the Form and Growth of Branched Planar Snow Crystals in a Cloud
Authors: Takahashi Tsuneya
Published: August 2014

How liquid water content (LWC) and temperature affect the growth of branched planar snow crystals is poorly understood. To address this issue, a vertical supercooled cloud tunnel was used to grow 167 individual snow crystals for 10 min under nearly constant conditions. The LWC varied within 0.07–0.76 g m−3 and average temperature varied from −12.4° to −16.3°C, with the latter varying by at most 0.2°C per run.

The crystal habits are divided mainly by temperature, warm to cold, into nine regions: sector above −12.5°C; then broad branch to −13.0°C; and then stellar, dendrite, and fern to −14.5°C. Then the pattern reverses, with dendrite to −14.8°C, stellar to −15.7°C, broad branch to −16.1°C, and finally sector. From −13.3° to −13.8°C, stellar changes to dendrite with LWC increase as well as with temperature decrease. From −13.8° to −14.5°C, dendrites coexist with ferns below an LWC of 0.25 g m−3, but only ferns exist at higher LWC. At other temperatures, a higher LWC does not produce greater side-branch development. Nevertheless, an increase of LWC produces heavier crystals (particularly crystals larger than 1 mm across), despite the crystal diameters being independent of LWC. Stellars at −14.9°C have the maximum mass and diameter, whereas ferns at about −14.3°C have the maximum basal-plane area and minimum fall speed. The apparent crystal density varies with temperature, with two local minima for stellars near −13.3° and −15.3°C and a local maximum for ferns near −14.2°C.
Improving the Prediction of the Summer Asian–Pacific Oscillation Using the Interannual Increment Approach
Authors: Huang Yanyan , Wang Huijun , Fan Ke
Published: August 2014

The summer Asian–Pacific oscillation (APO) is a dominant teleconnection pattern over the extratropical Northern Hemisphere that links the large-scale atmospheric circulation anomalies over the Asian–North Pacific Ocean sector. In this study, the direct Development of a European Multimodel Ensemble System for Seasonal-to-Interannual Prediction (DEMETER) model outputs from 1960 to 2001, which are limited in predicting the interannual variability of the summer Asian upper-tropospheric temperature and the decadal variations, are applied using the interannual increment approach to improve the predictions of the summer APO. By treating the year-to-year increment as the predictand, the interannual increment scheme is shown to significantly improve the predictive ability for the interannual variability of the summer Asian upper-tropospheric temperature and the decadal variations. The improvements for the interannual and interdecadal summer APO variability predictions in the interannual increment scheme relative to the original scheme are clear and significant. Compared with the DEMETER direct outputs, the statistical model with two predictors of APO and sea surface temperature anomaly over the Atlantic shows a significantly improved ability to predict the interannual variability of the summer rainfall over the middle and lower reaches of the Yangtze River valley (SRYR). This study therefore describes a more efficient approach for predicting the APO and the SRYR.
On the Estimation of Lagrangian Diffusivity: Influence of Nonstationary Mean Flow
Authors: Qian Yu-Kun , Peng Shiqiu , Liang Chang-Xia , Lumpkin Rick
Published: August 2014

Eddy–mean flow decomposition is crucial to the estimation of Lagrangian diffusivity based on drifter data. Previous studies have shown that inhomogeneous mean flow induces shear dispersion that increases the estimated diffusivity with time. In the present study, the influences of nonstationary mean flows on the estimation of Lagrangian diffusivity, especially the asymptotic behavior, are investigated using a first-order stochastic model, with both idealized and satellite-based oceanic mean flows. Results from both experiments show that, in addition to inhomogeneity, nonstationarity of mean flows that contain slowly varying signals, such as a seasonal cycle, also cause large biases in the estimates of diffusivity within a time lag of 2 months if a traditional binning method is used. Therefore, when assessing Lagrangian diffusivity over regions where a seasonal cycle is significant [e.g., the Indian Ocean (IO) dominated by monsoon winds], inhomogeneity and nonstationarity of the mean flow should be simultaneously taken into account in eddy–mean flow decomposition. A temporally and spatially continuous fit through the Gauss–Markov (GM) estimator turns out to be very efficient in isolating the effects of inhomogeneity and nonstationarity of the mean flow, resulting in estimates that are closest to the true diffusivity, especially in regions where strong seasonal cycles exist such as the eastern coast of Somalia and the equatorial IO.
Ethnic Minority Students’ Career Expectations in Prospective Professions: Navigating between Ambitions and Discrimination
Authors: Abrahamsen Bente , Drange Ida
Published: August 2014

This study sheds light on how ethnic minority students in Norway seek to navigate occupational opportunities after graduating from professional bachelor programmes. Students’ career ambitions and career expectations are investigated. The study adopts a comparative approach and includes students of Asian origin and western minority students as well as majority students. The findings show that ethnic minorities have higher career ambitions than majority students, but their career expectations are not correspondingly high. The study identifies ethnicity both as a resource (ethnic capital) and as an obstacle in the pursuit of a professional career. Structural disadvantages such as perceived discrimination seem to curb the utility of ethnic capital in capitalising on occupational opportunities, particularly for managerial positions. Ethnicity as a resource seems to play a role among both Asian and western minority students, and appears particularly strong in the development of career ambitions and in the efforts to pursue educational qualifications.