bluuebunny/crossref_metadata_2025 huggingface dataset:
The implementation of a municipal indoor ice skating helmet policy: effects on helmet use, participation and attitudes
Authors: O'Mahony-Menton Colleen , Willmore Jacqueline , Russell Katherine
Published: May 2015

Relevant local injury epidemiology

In Ottawa, between 2005 and 2009 there was an annual average of 47.2 head injuries due to ice skating in children and youth (1–19 years of age) requiring a visit to the emergency department, with the highest rates among those aged 5–14 years. Between 2002 and 2007, only 6% of children were wearing a helmet during ice skating when the head injury occurred. During indoor public skating sessions, 93% of children (<10 years)—57% aged 10–12 years, 20% aged 13–17 years and 9% adults—wore helmets in the absence of a policy. Support for a helmet policy was high from public health, medical, political and community perspectives.

Best practice

Helmet policies in relation to cycling have demonstrated increases in helmet use and reduction of head injuries without decreasing physical activity. However, no known studies have examined the effect of indoor ice skating helmet policy coupled with education and promotional activities on helmet use, participation and attitudes towards helmet use.

Implementation

An ice skating helmet policy for children (<11 years of age) and those with limited skating experience at indoor rinks during public skating sessions was developed, implemented and evaluated. Supportive activities such as discount coupons, promotional materials, a media launch, social marketing and staff training are described.

Discussion

The helmet policy was associated with increased helmet use for young children and for older children, youth and adults not included in the policy, without decreasing attendance to public skating sessions.
SILK flow diverter for complex intracranial aneurysms: a Canadian registry
Authors: Shankar Jai Jai Shiva , Tampieri Donatella , Iancu Daniela , Cortes Maria , Agid Ronit , Krings Timo , Wong John , Lavoie Pascale , Ghostine Jimmy , Shettar Basavraj , Ritchie Krsita , Weill Alain
Published: May 2015

Introduction

The SILK flow diverter (SFD) is used for the treatment of complex intracranial aneurysms. Small case series have been reported in the literature but few studies with a large number of patients have been published. We present our experience with the SFD for the treatment of intracranial aneurysms in Canada.

Methods

Centers across Canada using SFDs were contacted to fill out a case report form for patients treated with an SFD in their center. Individual centers were responsible for approval from their ethics committee. Image analysis was performed by individual operators. The case report forms were collected and the final analysis was performed.

Results

A total of 92 patients were treated with SFDs in eight centers in Canada between January 2009 and August 2013. The aneurysms were located in the posterior circulation in 16 patients and in the anterior circulation in 76 patients. Most aneurysms (75%) were saccular in shape; 22% were fusiform and 3% were blister aneurysms. The size of the aneurysms varied from 2 to 60 mm with the neck varying from 2 to 60 mm. Perioperative morbidity and mortality were 8.7% and 2.2%, respectively. At the last available follow-up, 83.1% of the aneurysms were either completely or near-completely occluded. The rate of complications was higher for fusiform aneurysms (p<0.001).

Conclusions

The SFD appears to be an important tool for the treatment of complex intracranial aneurysms. Treatment outcomes and complication rates remain a problem, but should be considered in the context of available alternative interventions. Ongoing analysis of flow-diverting stents for radiographic and clinical performance is required.
Flow diversion of large internal carotid artery aneurysms with the surpass device: impressions and technical nuance from the initial North American experience
Authors: Colby Geoffrey P , Lin Li-Mei , Caplan Justin M , Jiang Bowen , Michniewicz Barbara , Huang Judy , Tamargo Rafael J , Coon Alexander L
Published: May 2015

Background

Flow diversion is an important tool for treatment of cerebral aneurysms, particularly large and giant aneurysms. The Surpass flow diverter is a new system under evaluation in the USA.

Objective

To report our initial experience of 20 cases with the Surpass flow diverter to demonstrate its basic properties, the required triaxial delivery platform, and the methodologies used to deploy it during treatment of large internal carotid artery (ICA) aneurysms

Methods

Twenty patients with ICA aneurysms ≥10 mm with ≥4 mm neck treated as part of the Surpass IntraCranial Aneurysm Embolization System Pivotal Trial (the SCENT trial; Stryker) were included. Details of patient demographics, aneurysm characteristics, and technical procedures were collected.

Results

Twenty patients (mean age 63.3±1.3 years; range 51–72) with 20 unruptured aneurysms (mean size 13.4±0.9 mm; range 10–21 mm) were treated. For proximal access, 60% of cases had aortic arch ≥grade II, 55% had significant cervical ICA tortuosity, and 60% had cavernous ICA ≥grade II. The Surpass device was implanted in 19/20 (95%) cases. Of 19 cases, a single device was used in 18 cases (95%) and 2 devices in only 1 case (5%). Balloon angioplasty was performed in 8/19 cases (42%). Complete aneurysm neck coverage and adequate vessel wall apposition was obtained in all 19 cases.

Conclusions

Surpass is a next-generation flow diverter with unique device-specific and delivery-specific features compared with clinically available endoluminal flow diverters. Our initial experience demonstrates a favorable technical profile in treatment of large and giant ICA aneurysms.

Trial registration number

NCT01716117.
Step potential problem and harmonic oscillator problem in the minimum length quantum mechanics
Authors: Park Soyeon , Woo Byeong Hyo , Jung Min , Jang Eun Ji , Chung Won Sang
Published: May 2015

In this paper, we use the quasi-position representation of the minimum length quantum mechanics (MLQM) to study the effects of minimum length uncertainty principle (MLUP) on the quantum mechanical system up to a first-order in β. We introduce the probability density and the probability flux to discuss two problems such as particle in a box and step potential problem. For the step potential, we compute the transmission coefficient and the reflection coefficient and compare them with those of the ordinary quantum mechanics. We also discuss the harmonic oscillator problem in MLQM.
Black hole qubit correspondence from quantum circuits
Authors: Prudêncio Thiago , Cirilo-Lombardo Diego Julio , Silva Edilberto O. , Belich Humberto
Published: May 2015

We consider the black hole qubit correspondence (BHQC) from quantum circuits, taking into account the use of gate operations with base in the formulation of wrapped brane qubits. We interpret these quantum circuits with base on the BHQC classification of entanglement classes and apply in specific examples as the generation of Bell, Greenberger–Horne–Zeilinger (GHZ) states, quantum circuit teleportation and consider the implementation of interchanges in supersymmetry (SUSY), black hole configurations, Freudenthal and rank system constructions. These results are discussed from the superstring viewpoint showing that the importance of the construction of the physical states formed by the entanglement of geometrical entities by cohomological operations automatically allows the preservation of different amounts of SUSY in the compactification process given an alternative to the case when fluxes are introduced in the game: the generalized Calabi–Yau of Hitchin.
Discrete canonical analysis of three-dimensional gravity with cosmological constant
Authors: Berra-Montiel J. , E. Rosales-Quintero J.
Published: May 2015

We discuss the interplay between standard canonical analysis and canonical discretization in three-dimensional gravity with cosmological constant. By using the Hamiltonian analysis, we find that the continuum local symmetries of the theory are given by the on-shell space–time diffeomorphisms, which at the action level, correspond to the Kalb–Ramond transformations. At the time of discretization, although this symmetry is explicitly broken, we prove that the theory still preserves certain gauge freedom generated by a constant curvature relation in terms of holonomies and the Gauss's law in the lattice approach.
Time-average based on scaling law in anomalous diffusions
Authors: Kim Hyun-Joo
Published: May 2015

To solve the obscureness in measurement brought about from the weak ergodicity breaking appeared in anomalous diffusions, we have suggested the time-averaged mean squared displacement (MSD) [Formula: see text] with an integral interval depending linearly on the lag time τ. For the continuous time random walk describing a subdiffusive behavior, we have found that [Formula: see text] like that of the ensemble-averaged MSD, which makes it be possible to measure the proper exponent values through time-average in experiments like a single molecule tracking. Also, we have found that it has originated from the scaling nature of the MSD at an aging time in anomalous diffusion and confirmed them through numerical results of the other microscopic non-Markovian model showing subdiffusions and superdiffusions with the origin of memory enhancement.
First-principles study of hydrogen diffusion in transition metal palladium
Authors: Sarantuya Nasantogtokh , Cui Xin , Wang Zhi Ping
Published: May 2015

By adopting the first-principles total energy calculations based on density functional theory (DFT), the diffuse pattern and path of hydrogen in bulk palladium are investigated by calculating the system energy of hydrogen atom occupying different positions in palladium crystal lattice. The results indicate that the most stable position of hydrogen atom in palladium crystal lattice locates at the octahedral interstice, and the tetrahedral interstice is the second stable site. Hydrogen diffusion along the indirect octahedral–tetrahedral–octahedral (O–T–O) path is energetically most favorable in transition metal palladium, and the activation energy is 0.5245 eV.
Delay-Centric Handover Issues in Voice Transmissions with Multihomed SCTP
Authors: Runcos Rudolfo , Gavriloff Igor , Pedroso Carlos Marcelo , Fernandez Evelio Martin Garcia , Ribeiro Eduardo Parente
Published: May 2015

The Stream Control Transmission Protocol (SCTP) establishes a transport layer framework for multihomed communication where the standard failover mechanism improves the transmission resilience. A delay-centric handover mechanism for SCTP have been proposed to improve the end-to-end delay of real-time multimedia transmissions. In this paper, we explore the coexistence of delay-centric handover and standard SCTP failover to identify whether they work together to select a communication path that preserves voice transmission quality. The study was performed using computer simulations, which allowed us to evaluate users' perceived quality and network stability for several conditions of traffic load and packet loss ratio. Although voice quality is generally improved, conflicting decision about interface selection resulted in performance degradation under certain conditions. The global stability of the delay-centric operation when multiple independent voice transmissions compete for the available bandwidth was also evaluated. Simulations showed that under high link utilization, instabilities due to frequent path switching may lead to lower voice quality.
A Wide-Range Low-Jitter PLL Based on Fast-Response VCO and Simplified Straightforward Methodology of Loop Stabilization in Integer-N PLLs
Authors: Kazeminia Sarang , Hadidi Khayrollah , Khoei Abdollah
Published: May 2015

A straightforward methodology of optimizing ring-oscillator phase-locked loops (PLLs) is organized for integer-N PLLs. Then, a brief 4-step design flow is concluded to implicitly quantize the loop components for optimized loop stability. Theoretical analysis confirms that the ratio of more than 20 is required for loop filter's capacitors to yield at least 65° degrees phase margin. A wide-range voltage controlled oscillator (VCO) is proposed which is continuously controlled through two fast and slow response paths. The fast-response path improves RMS jitter due to decreasing loop delay and the slower one is an adaptive bias tuning loop, utilized to reduce the power consumption at lower operating frequencies. The RMS jitter of around 2 ps and 0.35 ps at 250 MHz and 4 GHz operating frequencies are obtained, respectively, where the 1.8 V supply voltage is subjected to about 60 mV peak-to-peak noise and reference clock suffers from 12 ps peak-to-peak jitter. Power consumption is reduced from 12.6–4 mW at 250 MHz operating frequency when the adaptive bias scheme is applied. Furthermore, simulation results confirm 35% and 50% improvement in RMS and peak-to-peak jitter at 250 MHz operating frequency, respectively, when the ratio of capacitances is increased from 10 to 20 within the loop filter. The proposed PLL can be implemented in 170 μm × 250 μm active area in 0.18 μm CMOS process.
An Empirical Investigation on Wrapper-Based Feature Selection for Predicting Software Quality
Authors: Wang Huanjing , Khoshgoftaar Taghi M. , Napolitano Amri
Published: May 2015

The basic measurements for software quality control and management are the various project and software metrics collected at various states of a software development life cycle. The software metrics may not all be relevant for predicting the fault proneness of software components, modules, or releases. Thus creating the need for the use of feature (software metric) selection. The goal of feature selection is to find a minimum subset of attributes that can characterize the underlying data with results as well as, or even better than the original data when all available features are considered. As an example of inter-disciplinary research (between data science and software engineering), this study is unique in presenting a large comparative study of wrapper-based feature (or attribute) selection techniques for building defect predictors. In this paper, we investigated thirty wrapper-based feature selection methods to remove irrelevant and redundant software metrics used for building defect predictors. In this study, these thirty wrappers vary based on the choice of search method (Best First or Greedy Stepwise), leaner (Naïve Bayes, Support Vector Machine, and Logistic Regression), and performance metric (Overall Accuracy, Area Under ROC (Receiver Operating Characteristic) Curve, Area Under the Precision-Recall Curve, Best Geometric Mean, and Best Arithmetic Mean) used in the defect prediction model evaluation process. The models are trained using the three learners and evaluated using the five performance metrics. The case study is based on software metrics and defect data collected from a real world software project.

The results demonstrate that Best Arithmetic Mean is the best performance metric used within the wrapper. Naïve Bayes performed significantly better than Logistic Regression and Support Vector Machine as a wrapper learner on slightly and less imbalanced datasets. We also recommend Greedy Stepwise as a search method for wrappers. Moreover, comparing to models built with full datasets, the performances of defect prediction models can be improved when metric subsets are selected through a wrapper subset selector.
Investigating Two Approaches for Adding Feature Ranking to Sampled Ensemble Learning for Software Quality Estimation
Authors: Gao Kehan , Khoshgoftaar Taghi M. , Napolitano Amri
Published: May 2015

Defect prediction is very challenging in software development practice. Classification models are useful tools that can help for such prediction. Classification models can classify program modules into quality-based classes, e.g. fault-prone (fp) or not-fault-prone (nfp). This facilitates the allocation of limited project resources. For example, more resources are assigned to program modules that are of poor quality or likely to have a high number of faults based on the classification. However, two main problems, high dimensionality and class imbalance, affect the quality of training datasets and therefore classification models. Feature selection and data sampling are often used to overcome these problems. Feature selection is a process of choosing the most important attributes from the original dataset. Data sampling alters the dataset to change its balance level. Another technique, called boosting (building multiple models, with each model tuned to work better on instances misclassified by previous models), is found to also be effective for resolving the class imbalance problem.

In this study, we investigate an approach for combining feature selection with this ensemble learning (boosting) process. We focus on two different scenarios: feature selection performed prior to the boosting process and feature selection performed inside the boosting process. Ten individual base feature ranking techniques, as well as an ensemble ranker based on the ten, are examined and compared over the two scenarios. We also employ the boosting algorithm to construct classification models without performing feature selection and use the results as the baseline for further comparison. The experimental results demonstrate that feature selection is important and needed prior to the learning process. In addition, the ensemble feature ranking method generally has better or similar performance than the average of the base ranking techniques, and more importantly, the ensemble method exhibits better robustness than most base ranking techniques. As for the two scenarios, the results show that applying feature selection inside boosting performs better than using feature selection prior to boosting.
Quasi-alternating links and Kauffman polynomials
Authors: Teragaito Masakazu
Published: May 2015

We study the relation between the maximum z-degree of Kauffman polynomial and the determinant for a quasi-alternating link. This gives a stronger criterion for deciding whether a non-alternating link is quasi-alternating or not than the known criterion in terms of Q-polynomials. Also, we determine all quasi-alternating links with determinant 5.
Systematic dependence of Grodzins product rule on NpNn
Authors: Kumari Parveen , Mittal H. M.
Published: May 2015

The systematics of the Grodzins product rule (GPR) is studied from the perspective of the valence-proton and neutron product NpNn in the major shell space Z = 50–82, N = 82–126. The variation of nuclear structure from vibrator to deformed rotor is discussed. The Grodzins product shows more dependence on NpNn in the N ≤ 104 region, as it is a region of deformed nuclei. We present here for the first time the dependence of GPR on the NpNn product.
Centrality dependences of soft and hard components of pt distributions of negative pions in 4He+12C collisions at 4.2A GeV/c
Authors: Olimov Khusniddin K. , Iqbal Akhtar , Lutpullaev Sagdulla L. , Hadi Sayyed A. , Glagolev Viktor V. , Yuldashev B. S. , Haseeb Mahnaz Q.
Published: May 2015

The dependences of the shapes of transverse momentum distributions of the negative pions, produced in minimum bias 4 He +12 C collisions at a momentum of 4.2 GeV/c per nucleon, on collision centrality and fitting range of pt were analyzed systematically. To study the change in slopes (temperatures) of the pt spectra of π- with changing collision centrality and fitting pt range, the pt spectra, extracted from the experimental data and quark–gluon string model (QGSM) calculations, were fitted by the one- and two-temperature Hagedorn and Boltzmann functions. Fitting of the experimental pt distributions of π- in both the whole pt and pt = 0.1–1.2 GeV/c intervals required the two-temperature functions for adequate description of spectra, in agreement with the previous findings for different sets of colliding nuclei and various energies. On the whole, the absolute values of the extracted temperatures were lower in case of fitting range pt = 0.1–0.7 GeV/c as compared to the fitting interval pt = 0.1–1.2 GeV/c. The one-temperature functions were sufficient for fitting satisfactorily the experimental pt distributions of the negative pions in range pt = 0.1–0.7 GeV/c. In contrast to the experimental temperatures, the extracted QGSM temperatures were not sensitive to collision centrality and fitting range of pt. The collision centrality dependences of the temperatures of soft (pt = 0.1–0.5 GeV/c) and hard (pt = 0.5–1.2 GeV/c) components of the experimental pt distributions of the negative pions in 4 He +12 C collisions at 4.2A GeV/c were studied separately. The extracted temperatures of both soft and hard components of pt distributions of π- depended on geometry (size) and degree of overlap of colliding nuclei in peripheral, semicentral and central 4 He +12 C collisions. The temperature of soft pt component of the negative pions was consistently larger in semicentral and central 4 He +12 C collisions than that in peripheral interactions. The temperature of hard pt component of π- in 4 He +12 C collisions decreased consistently with an increase in collision centrality. The physical interpretations of the observed centrality dependences of temperature (T) of soft and hard pt components of the negative pions in 4 He +12 C collisions were given.
Three-slit ghost interference and non-local duality
Authors: Siddiqui Mohd Asad
Published: May 2015

A three-slit ghost interference experiment with entangled photons is theoretically analyzed using wave-packet dynamics. A non-local duality relation is derived which connects the path distinguishability of one photon to the interference visibility of the other.
Evaluating Group-Robot Interaction in Crowded Public Spaces: A Week-Long Exploratory Study in the Wild with a Humanoid Robot Guiding Visitors Through a Science Museum
Authors: Díaz-Boladeras Marta , Paillacho Dennys , Angulo Cecilio , Torres Oriol , González-Diéguez Jonathan , Albo-Canals Jordi
Published: May 2015

This paper describes an exploratory study on group interaction with a robot guide in an open large-scale busy environment. For an entire week, a humanoid robot was deployed in the popular Cosmocaixa Science Museum in Barcelona and guided hundreds of people through the museum facilities. The main goal of this experience is to study in the wild the episodes of the robot guiding visitors to a requested destination focusing on the group behavior during displacement. The walking behavior follow-me and the face-to-face communication in a populated environment are analyzed in terms of guide–visitors interaction, grouping patterns and spatial formations. Results from observational data show that the space configurations spontaneously formed by the robot guide and visitors walking together did not always meet the robot communicative and navigational requirements for successful guidance. Therefore, additional verbal and nonverbal prompts must be considered to regulate effectively the walking together and follow-me behaviors. Finally, we discuss lessons learned and recommendations for robot’s spatial behavior in dense crowded scenarios.
COMBINATION THERAPIES OR STANDALONE INTERVENTIONS? INNOVATION OPTIONS FOR PHARMACEUTICAL FIRMS FIGHTING CANCER
Authors: BHARDWAJ GUNJAN , AGRAWAL ANSHIT , TYAGI RUPESH
Published: May 2015

Innovation is key to the pharma model, from an initial discovery to the final development of a marketable drug. Here, we explore the innovation options in the fiercely contested therapeutic area of Oncology. We studied clinical development of drugs targeting PD-1 and PD-L1 pathway. In this interesting contest, companies seem to be focusing on standalone interventions (exploratory innovation) and combination therapy (exploitative innovation) in clinical development. Merck Sharp and Dohme, having a relatively weaker oncology pipeline seems to take exploratory approach of standalone intervention. However for some indications, MSD seems to harness exploitative innovation approach through combination therapies by collaborating with external partners. AstraZeneca in contrast seems to focus on exploitative approach using its strong oncology pipeline for combination therapies. Our work provides a framework to understand exploratory (standalone) and exploitative (combination therapy) innovation approaches and their relationship to capability, scientific networks and market access for a company entering a fiercely contested pharmaceutical market.
LEAN AND GLOBAL TECHNOLOGY START-UPS: LINKING THE TWO RESEARCH STREAMS
Authors: TANEV STOYAN , RASMUSSEN ERIK STAVNSAGER , ZIJDEMANS ERIK , LEMMINGER ROY , SVENDSEN LARS LIMKILDE
Published: May 2015

In this paper, the authors introduce the concept of the lean global start-up (LGS) as a way of emphasising the problems for new technology start-ups when dealing separately with business development, innovation and early internationalisation. The paper has two components — an introductory conceptual part and an empirical part that should be considered as basis for the preliminary validation of the conceptual insights. The research sample includes six firms — three from Canada and three from Denmark. Two different early internationalisation paths have been identified: Lean-to-global (L2G start-ups) and lean-and-global (L&G start-ups). Both types of start-ups were found to have faced significant problems with the complexity, uncertainties and risks of being innovative on a global scale. They have however found ways of addressing these problems by a disciplined knowledge sharing and IP protection strategy and the efficient use of business and supporting and public funding mechanisms. The Danish firms have pivoted around the ways of delivering their value proposition and not around the specific value propositions themselves. The Canadian firms have actively pivoted their value proposition motivated by the degree of innovativeness of their products and the insights from business supporting organisations. The analysis of the results justifies the introduction of the LGS concept and opens the opportunity for future research focusing on the articulation of more practical LGS entrepreneurial frameworks.
Information Asymmetry and Corporate Governance
Authors: Cai Jie , Liu Yixin , Qian Yiming , Yu Miaomiao
Published: May 2015

We examine the impact of a firm’s asymmetric information on its choice of three mechanisms of corporate governance: The intensity of board monitoring, the exposure to market discipline, and CEO pay-for-performance sensitivity. We find that firms facing greater asymmetric information tend to use less intensive board monitoring but rely more on market discipline and CEO incentive alignment. These results are consistent with the monitoring cost hypothesis. In addition, we find that high information-asymmetry firms that have to substantially increase board monitoring intensity after the Sarbanes–Oxley Act suffer poor stock performance. Our evidence therefore suggests that regulators should use caution when imposing uniform corporate governance requirements on all firms.
Limiting spectral distribution of a class of Hankel type random matrices
Authors: Basak Anirban , Bose Arup , Mukherjee Soumendu Sundar
Published: May 2015

We consider an indexed class of real symmetric random matrices which generalize the symmetric Hankel and Reverse Circulant matrices. We show that the limiting spectral distribution of these matrices exists almost surely and the limit is continuous in the index. We also study other properties of the limit and, in particular, explicitly characterize it for a certain subclass of matrices as a mixture of the atomic distribution at zero and the symmetrized Rayleigh distribution.
Matrix models, Toeplitz determinants and recurrence times for powers of random unitary matrices
Authors: Marchal O.
Published: May 2015

The purpose of this paper is to study the eigenvalues [Formula: see text] of Ut where U is a large N×N random unitary matrix and t > 0. In particular we are interested in the typical times t for which all the eigenvalues are simultaneously close to 1 in different ways thus corresponding to recurrence times in the issue of quantum measurements. Our strategy consists in rewriting the problem as a random matrix integral and use loop equations techniques to compute the first-orders of the large N asymptotic. We also connect the problem to the computation of a large Toeplitz determinant whose symbol is the characteristic function of several arc segments of the unit circle. In particular in the case of a single arc segment we recover Widom's formula. Eventually we explain why the first return time is expected to converge toward an exponential distribution when N is large. Numerical simulations are provided along the paper to illustrate the results.
A fluid dynamics perspective on the interpretation of the surface thermal signal of lava flows
Authors: Garel F. , Kaminski É. , Tait S. , Limare A.
Published: May 2015

Effusion rate is a crucial parameter for the prediction of lava-flow advance and should be assessed in near real-time in order to better manage a volcanic crisis. Thermal remote sensing offers the most promising avenue to attain this goal. We present here a ‘dynamic’ thermal proxy based on laboratory experiments and on the physical framework of viscous gravity currents, which can be used to estimate the effusion rate from thermal remote sensing during an eruption. This proxy reproduces the first-order relationship between effusion rate measured in the field and associated powers radiated by basaltic lava flows. Laboratory experiments involving fluids with complex rheology and subject to solidification give additional insights into the dynamics of lava flows. The introduction of a time evolution of the supply rates during the experiments gives rise to a transient adjustment of the surface thermal signal that further compromises the simple proportionality between the thermal flux and the effusion rate. Based on the experimental results, we conclude that a thermal proxy can only yield a minimum and time-averaged estimate of the effusion rate.
θ-Defensin RTD-1 improves insulin action and normalizes plasma glucose and FFA levels in diet-induced obese rats
Authors: Oh Young Taek , Tran Dat , Buchanan Thomas A. , Selsted Michael E. , Youn Jang H.
Published: May 2015

Inflammation is implicated in metabolic abnormalities in obesity and type 2 diabetes. Because θ-defensins have anti-inflammatory activities, we tested whether RTD-1, a θ-defensin, improves metabolic conditions in diet-induced obesity (DIO). DIO was induced by high-fat feeding in obese-prone CD rats from 4 wk of age. Starting at age 10 wk, the DIO rats were treated with saline or RTD-1 for 4 or 8 wk. DIO rats gained more weight than low-fat-fed controls. RTD-1 treatment did not alter body weight or calorie intake in DIO rats. Plasma glucose, FFA, triglyceride (TG), and insulin levels increased in DIO rats; RTD-1 normalized plasma glucose and FFA levels and showed tendencies to lower plasma insulin and TG levels. Hepatic and skeletal muscle TG contents increased in DIO rats; RTD-1 decreased muscle, but not hepatic, TG content. Insulin sensitivity, estimated using homeostasis model assessment of insulin resistance and the glucose clamp technique, decreased in DIO rats, but this change was markedly reversed by RTD-1. RTD-1 had no significant effects on plasma cytokine/chemokine levels or IL-1β and TNF-α expression in liver or adipose tissues. RTD-1 treatment decreased hepatic expression of phospho enolpyruvate carboxykinase and glucose-6-phosphatase, suggesting that the effect of RTD-1 on plasma glucose (or insulin action) might be mediated by its effect to decrease hepatic gluconeogenesis. Thus, RTD-1 ameliorated insulin resistance and normalized plasma glucose and FFA levels in DIO rats, supporting the potential of RTD-1 as a novel therapeutic agent for insulin resistance, metabolic syndrome, or type 2 diabetes.
MALDI-TOF Mass Array Analysis ofNell-1Promoter Methylation Patterns in Human Gastric Cancer
Authors: Gao Changlu , Zhang Qian , Kong Deyang , Wu Di , Su Changlei , Tong Jinxue , Chen Feng , Zhang Qifan
Published: May 2015

Mass spectrometry (MS) enables rapid and sensitive qualitative and quantitative analyses of biomolecules (proteins, peptides, oligosaccharides, lipids, DNA, and RNA), drugs, and metabolites. MS has become an essential tool in modern biomedical research, including the analysis of DNA methylation. DNA methylation has been reported in many cancers, suggesting that it can be utilized as an early biomarker to improve the early diagnosis rate. Using matrix-assisted laser desorption/ionization time-of-flight MS and MassCLEAVE reagent, we comparedNell-1hypermethylation levels among tumor tissues, paracarcinoma tissues, and normal tissues from gastric cancer patients. Almost 80% of the CpG sites in the amplicons produced were covered by the analysis. Our results indicate a significant difference in methylation status between gastric cancer tissue (a higher level) and normal tissue. The same trend was identified in gastric cancer tissue versus paracarcinoma tissue. We also detected lower relative expression ofNell-1by real-time PCR. Furthermore, immunohistochemical analyses revealed thatNell-1staining was less intense in cancer tissue relative to normal tissue and that the tumor cells had spread to the muscle layer. These findings may serve as a guide for the early diagnosis of gastric cancer.
Vitamin A and Retinoids as Mitochondrial Toxicants
Authors: de Oliveira Marcos Roberto
Published: May 2015

Vitamin A and its derivatives, the retinoids, are micronutrient necessary for the human diet in order to maintain several cellular functions from human development to adulthood and also through aging. Furthermore, vitamin A and retinoids are utilized pharmacologically in the treatment of some diseases, as, for instance, dermatological disturbances and some types of cancer. In spite of being an essential micronutrient with clinical application, vitamin A exerts several toxic effects regarding redox environment and mitochondrial function. Moreover, decreased life quality and increased mortality rates among vitamin A supplements users have been reported. However, the exact mechanism by which vitamin A elicits its deleterious effects is not clear yet. In this review, the role of mitochondrial dysfunction in the mechanism of vitamin A-induced toxicity is discussed.
Role of the Ubiquitin-Proteasome Systems in the Biology and Virulence of Protozoan Parasites
Authors: Muñoz Christian , San Francisco Juan , Gutiérrez Bessy , González Jorge
Published: May 2015

In eukaryotic cells, proteasomes perform crucial roles in many cellular pathways by degrading proteins to enforce quality control and regulate many cellular processes such as cell cycle progression, signal transduction, cell death, immune responses, metabolism, protein-quality control, and development. The catalytic heart of these complexes, the 20S proteasome, is highly conserved in bacteria, yeast, and humans. However, until a few years ago, the role of proteasomes in parasite biology was completely unknown. Here, we summarize findings about the role of proteasomes in protozoan parasites biology and virulence. Several reports have confirmed the role of proteasomes in parasite biological processes such as cell differentiation, cell cycle, proliferation, and encystation. Proliferation and cell differentiation are key steps in host colonization. Considering the importance of proteasomes in both processes in many different parasites such asTrypanosoma, Leishmania, Toxoplasma,andEntamoeba, parasite proteasomes might serve as virulence factors. Several pieces of evidence strongly suggest that the ubiquitin-proteasome pathway is also a viable parasitic therapeutic target. Research in recent years has shown that the proteasome is a valid drug target for sleeping sickness and malaria. Then, proteasomes are a key organelle in parasite biology and virulence and appear to be an attractive new chemotherapeutic target.
A PETSc-Based Parallel Implementation of Finite Element Method for Elasticity Problems
Authors: Zhang Jianfei
Published: May 2015

Starting a parallel code from scratch is not a good choice for parallel programming finite element analysis of elasticity problems because we cannot make full use of our existing serial code and the programming work is painful for developers. PETSc provides libraries for various numerical methods that can give us more flexibility in migrating our serial application code to a parallel implementation. We present the approach to parallelize the existing finite element code within the PETSc framework. Our approach permits users to easily implement the formation and solution of linear system arising from finite element discretization of elasticity problem. The main PETSc subroutines are given for the main parallelization step and the corresponding code fragments are listed. Cantilever examples are used to validate the code and test the performance.
Relationship of Soluble RAGE with Insulin Resistance and Beta Cell Function during Development of Type 2 Diabetes Mellitus
Authors: Biswas Subrata Kumar , Mohtarin Sabreena , Mudi Sonchita Rani , Anwar Taznuva , Banu Laila Anjuman , Alam Sheikh Md. Khorshed , Fariduddin Md. , Arslan M. Iqbal
Published: May 2015

This study examined whether circulating levels of soluble receptor for advanced glycation end products (sRAGE) alter in prediabetes and correlate with insulin resistance (IR) and beta cell function in prediabetes and newly diagnosed type 2 diabetes mellitus (T2DM). Subjects without previous history of diabetes were recruited and grouped as control, prediabetes, and newly diagnosed T2DM. The control subjects (n=40) and people with prediabetes (n=52) and diabetes (n=66) were similar in terms of age, sex, BMI, systolic and diastolic BP, and fasting insulin level. HOMA-IR was found significantly higher in people with diabetes than control subjects (p<0.001) and people with prediabetes (p=0.005); and HOMA-%B was found significantly deteriorated in people with diabetes (p<0.001) compared to control subjects and people with prediabetes. However, serum sRAGE levels did not show any significant alteration in people with prediabetes compared to control subjects. Moreover, univariate and multivariate analyses did not identify any significant correlation and statistical association of sRAGE with HOMA-IR and HOMA-%B in people with prediabetes and newly diagnosed T2DM. Our data suggest that serum sRAGE levels do not alter in people with prediabetes compared to control subjects and do not correlate or associate with IR and beta cell function during development of T2DM.
Myeloid‐Derived Suppressor Cells and Therapeutic Strategies in Cancer
Authors: Katoh Hiroshi , Watanabe Masahiko
Published: May 2015

Development of solid cancer depends on escape from host immunosurveillance. Various types of immune cells contribute to tumor‐induced immune suppression, including tumor associated macrophages, regulatory T cells, type 2 NKT cells, and myeloid‐derived suppressor cells (MDSCs). Growing body of evidences shows that MDSCs play pivotal roles among these immunosuppressive cells in multiple steps of cancer progression. MDSCs are immature myeloid cells that arise from myeloid progenitor cells and comprise a heterogeneous immune cell population. MDSCs are characterized by the ability to suppress both adaptive and innate immunities mainly through direct inhibition of the cytotoxic functions of T cells and NK cells. In clinical settings, the number of circulating MDSCs is associated with clinical stages and response to treatment in several cancers. Moreover, MDSCs are reported to contribute to chemoresistant phenotype. Collectively, targeting MDSCs could potentially provide a rationale for novel treatment strategies in cancer. This review summarizes recent understandings of MDSCs in cancer and discusses promissing clinical approaches in cancer patients.
Mass Spectrometry in Pharmacokinetic Studies of a Synthetic Compound for Spinal Cord Injury Treatment
Authors: Sánchez-Sierra María , García-Álvarez Isabel , Fernández-Mayoralas Alfonso , Moreno-Lillo Sandra , Barroso García Gemma , Moral Dardé Verónica , Doncel-Pérez Ernesto
Published: May 2015

The studies of drugs that could constitute a palliative to spinal cord injury (SCI) are a continuous and increasing demand in biomedicine field from developed societies. Recently we described the chemical synthesis and antiglioma activity of synthetic glycosides. A synthetic sulfated glycolipid (here IG20) has shown chemical stability, solubility in polar solvents, and high inhibitory capacity over glioma growth. We have used mass spectrometry (MS) to monitor IG20m/z=550.3in cells and tissues of the central nervous system (CNS) that are involved in SCI recovery. IG20 was detected by MS in serum and homogenates from CNS tissue of rats, though in the latter a previous deproteinization step was required. The pharmacokinetic parameters of serum clearance at 24 h and half-life at 4 h were determined for synthetic glycoside in the adult rat using MS. A local administration of the drug near of spinal lesion site is proposed.
Steroid Anti-Inflammatory Effects Did Not Improve Organ Quality in Brain-Dead Rats
Authors: Rebolledo Rolando A. , Liu Bo , Akhtar Mohammed Z. , Ottens Petra J. , Zhang Jian-ning , Ploeg Rutger J. , Leuvenink Henri G. D.
Published: May 2015

Effect of glucocorticoid administration on improving the outcomes of kidney and liver allografts has not been clearly elucidated. This study investigated the effect of prednisolone administration after onset of brain death (BD) on kidney and liver in a controlled rat model of BD. BD was induced in rats by inflating an epidurally placed balloon catheter. Animals were treated with saline or prednisolone (5, 12.5, or 22.5 mg/kg) one hour after the onset of BD. After 4 hours of BD, experiments were terminated and serum and tissues were collected. Tissue gene and protein expression were measured for markers of inflammation, apoptosis, and cellular stress response markers. Prednisolone caused a reduction of plasma levels of IL-6, while the tissue expression ofIL-6, IL-1β,andMCP-1in both kidney and liver were also reduced. Creatinine plasma levels, complement (C3) expression,HSP-70, HO-1, Bcl2/BAXratio, and PMN influx did not significantly change in kidney nor liver. Plasma AST and LDH levels were increased in the prednisolone treated group. Our results demonstrate prednisolone can has an anti-inflammatory effect mediated through reducing serum circulating cytokines. However, this anti-inflammatory effect does not translate into improved kidney function and indeed was associated with increased liver injury markers.
Some Progress on Parallel Modal and Vibration Analysis Using the JAUMIN Framework
Authors: Fan Xuanhua , Wang Keying , Xiao Shifu , Liu Qingkai , Mo Zeyao
Published: May 2015

In the development of large and complex equipment, a large-scale finite element analysis (FEA) with high efficiency is often strongly required. This paper provides some progress on parallel solution of large-scale modal and vibration FE problems. Some predominant algorithms for modal and vibration analysis are firstly reviewed and studied. Based on the newly developed JAUMIN framework, the corresponding procedures are developed and integrated to form a parallel modal and vibration solution system; the details of parallel implementation are given. Numerical experiments are carried out to evaluate the parallel scalability of our procedures, and the results show that the maximum solution scale attains ninety million degrees of freedom (DOFs) and the maximum parallel CPU processors attain 8192 with favorable computing efficiency.
Self-Reported ADHD Symptoms and Interhemispheric Interaction in Adults: A Dimensional Approach
Authors: Mohamed Saleh M. H. , Börger Norbert A. , Geuze Reint H. , van der Meere Jaap J.
Published: May 2015

The present study applied the dimensional approach to test whether self-reported symptoms of Attention Deficit/Hyperactivity Disorder (ADHD) in adults are associated with the speed of interhemispheric interaction. A sample of first grade students (N=112) completed Conners’ Adult ADHD Rating Scales and letter matching reaction time tasks. In the tasks, participants had to match a single target letter displayed below the fixation cross, either on left or right visual field, with one of two letters displayed above the fixation cross, one letter on each visual field. For each task, identical letters were presented either within the same visual field (within hemisphere condition) or across visual fields (across hemisphere condition). Interhemispheric interaction was indexed as the difference in mean reaction time between within and across hemisphere conditions. Comorbid problems such as depression, anxiety, and stress may affect task performance and are controlled for in this study. Findings indicated that self-reported ADHD symptomology, especially hyperactivity, in the presence of stress was weakly but significantly associated with fast interhemispheric interaction.
Endothelial Injury Associated with Cold or Warm Blood Cardioplegia during Coronary Artery Bypass Graft Surgery
Authors: Kuhn Elmar W. , Choi Yeong-Hoon , Pyun Jung-Min , Neef Klaus , Liakopoulos Oliver J. , Stamm Christof , Wittwer Thorsten , Wahlers Thorsten
Published: May 2015

The aim of this investigation was to analyze the impact of intermittent cold blood cardioplegia (ICC) and intermittent warm blood cardioplegia (IWC) on endothelial injury in patients referred to elective on-pump coronary artery bypass graft (CABG) surgery. Patients undergoing CABG procedures were randomized to either ICC or IWC. Myocardial injury was assessed by CK-MB and cardiac troponin T (cTnT). Endothelial injury was quantified by circulating endothelial cells (CECs), von Willebrand factor (vWF), and soluble thrombomodulin (sTM). Perioperative myocardial injury (PMI) and major adverse cardiac events (MACE) were recorded. Demographic data and preoperative risk profile of included patients (ICC:n=32, IWC:n=36) were comparable. No deaths, PMI, or MACE were observed. Levels of CK-MB and cTnT did not show intergroup differences. Concentrations of CECs peaked at 6 h postoperatively with significantly higher values for IWC-patients at 1 h (ICC: 10.1 ± 3.9/mL; IWC: 18.4 ± 4.1/mL;P=0.012) and 6 h (ICC: 19.3 ± 6.2/mL; IWC: 29.2 ± 6.7/mL;P<0.001). Concentrations of vWF (ICC: 178.4 ± 73.2 U/dL; IWC: 258.2 ± 89.7 U/dL;P<0.001) and sTM (ICC: 3.2 ± 2.1 ng/mL; IWC: 5.2 ± 2.4 ng/mL;P=0.011) were significantly elevated in IWC-group at 1 h postoperatively. This study shows that the use of IWC is associated with a higher extent of endothelial injury compared to ICC without differences in clinical endpoints.
A Study of Transverse Momentum Distributions of Jets Produced inp-p,p-p-,d-Au, Au-Au, and Pb-Pb Collisions at High Energies
Authors: Wei Hua-Rong , Liu Fu-Hu
Published: May 2015

The transverse momentum distributions of jets produced inp-p,p-p-,d-Au, Au-Au, and Pb-Pb collisions at high energies with different selected conditions are analyzed by using a multisource thermal model. The multicomponent (mostly two-component) Erlang distribution used in our description is in good agreement with the experimental data measured by the STAR, D0, CDF II, ALICE, ATLAS, and CMS Collaborations. Related parameters are extracted from the transverse momentum distributions and some information on different interacting systems is obtained. In the two-component Erlang distribution, the first component has usually two or more sources which are contributed by strong scattering interactions between two quarks or more quarks and gluons, while the second component has mostly two sources which are contributed by harder head-on scattering between two quarks.