bluuebunny/crossref_metadata_2025 huggingface dataset:
Flow Instabilities in Gas-Lift Wells with Water Coning
Authors: Aguilar M. Lozada , Romero E. Poblano , Sarabia I. Gerrero , Fairuzov Y. V.
Published: September 2011

Linear and nonlinear stability analysis of flow instabilities gas-lift wells with water coning was performed in this paper. A new gas-lift stability criterion, which takes into account water coning, was developed. The criterion was used to analyze flow instability in an offshore gas-lift well. The effect of the water-coning performance on the conditions of the onset of instabilities was investigated. The nonlinear analysis showed that one of the most important instability modes in gas-lift wells is associated with two types of density waves: liquid and water holdup waves. Flow instability in gas-lift wells may result in that the maximum instantaneous liquid flow rate may be several times larger the average liquid flow rate for long periods of time (tens of minutes) in one cycle of oscillation. It was shown that water coning has a strong destabilizing effect on the flow in gas lift wells with a large vertical distance between the injection point and perforations. In some cases heading in such wells cannot be eliminated by increasing the wellhead pressure. One of the most important instability modes in gas-lift wells is associated with two types of density waves: liquid and water holdup waves.
Survival of Salmonella typhimurium NRRL E4463 in Sauerkraut during Fermentation
Authors: Karagozlu Nural , Ergönül Bülent
Published: September 2011

In this research, the survival characteristic of Salmonella typhimurium NRRL E4463 in sauerkraut during fermentation was investigated. Salmonella typhimurium strains were inoculated in sauerkraut, and counts were determined on the 0, 1st, 2nd, 4th, 6th and 7th days of the fermentation. It was observed that the initial count of Salmonella typhimurium was 6.61 log cfu/g on the inoculation day, and it declined to <1.0 log cfu/g on the 7th day of the fermentation. During this period, lactic acid bacteria counts of the Salmonella-inoculated sauerkraut were 5.41 log cfu/g and 7.43 log cfu/g on the 0 and 7th day of the fermentation, whereas these values were 1.36 log cfu/g and 6.57 log cfu/g for the control sample, respectively.
A formal framework for dependability and resilience from a software engineering perspective
Authors: Guelfi Nicolas
Published: September 2011

The goal of this article is to provide a rigorous conceptual framework for defining the concepts of dependability and resilience. Since the seventies, the terms dependability and resilience have been used in nearly all the scientific and technological fields related to Information and Communication systems. The introduction and use of these concepts in all these fields makes it difficult to have a common and precise definition. Having such a definition is nevertheless mandatory for the software and systems engineering research community that create development processes, languages and tools to support the engineering of products that would be required to be dependable or resilient. For this, we introduce an abstract and generic terminology defined mathematically to be used when speaking about dependability and resiliency. We also provide some abstract semantic descriptions to these terminological elements. This formal framework is defined from a software engineering perspective, which means that we define its components such that they are useful for the development or improvement of analysis, architectural design, detailed design, implementation, verification and maintenance phases. To this aim, we provide the necessary elements in accordance with a model driven engineering perspective that enable the definition of a new modelling language for dependable and resilient systems.
Key Technologies Research for Impellers Machining Based on NX
Authors: Li Xian Yi , Fu Jian Zhong , Li Ji Qiang
Published: September 2011

Tool path generation, post-processing and verification and simulation of NC program are key technologies which are investigated in this research for manufacturing impellers. Generation of tool path aims at producing the cutting tool path. Post-processing transforms the cutter location file (CLSF file) of the tool path to the NC code which NC machine can recognize. Verification and simulation of NC program aims at proving the accuracy of program, thus the interference and collision can be avoided. When tool path is planned, increasing the machining efficiency during the rough and semi-finish milling process is the main consideration. Increasing machining accuracy is an important consideration for final finish milling.
Application of Digital Speckle Correction Method to Inverted Camber Detection of Prestressed Foundation Beam
Authors: Xu Chen Guang , Wang Zhen Lin
Published: September 2011

Based on the principle of digital speckle correlation method (DSCM), a distance measuring DSCM system has been developed and realized. With the application of the system, the inverted camber of a pre-stressed beam of beam-slab transfer cadre was traced and analyzed in this paper. Compared with other experimental technique such as dial indicator test method, it shows that DSCM is a powerful optical deformation measurement tool with the required precision and on-site inspection ability.
The Distance Attenuation of Acoustic Emission Signals in Turbine Runners
Authors: Wang Xiang Hong , Hu Hong Wei , Shao Yi Min , Fu Jun Qing
Published: September 2011

Initiation of blade cracks in Francis turbine runners endangers the safety operation of power stations, so it is crucial to detect the cracks before emergencies happen. This article is a preliminary study of applying acoustic emission (AE) technique to detecting the large-scale turbine runners. A series of experiments had been carried out on an HLA286a-LJ-800 Francis turbine runner. The attenuation characteristics due to propagation distance were studied. From the tests, it is concluded that AE signals are detectable after propagating at a distance of 6 m. The propagation distance is the major factor of attenuation. As a result, although attenuation is incurred, it is feasible to apply AE technique to monitoring crack signals in runners. However, it depends on the understanding of background noise and extraction of right signals.
A Dynamic Characteristic Analysis of Continuous Welded Rail Track under Different Longitudinal Stress
Authors: Luo Yan Yun , Zhang Hu , Liu Yan
Published: September 2011

The paper presents a dynamic computational model and field test for analyzing the relationship between the rail natural frequencies and the longitudinal temperature stress by means of the finite element method. The essay use the infinite Timoshenko beam as the plane model to simulate continuous welded rail track structure and the rail model by means of the finite element method in order to its unit as a division of space elastomer. The test uses vertical incentive and horizontal incentive to encourage continuous welded rail track structure to get the rail natural frequencies. The measured data and the result of finite element analysis are compared, finds the results are consistent. The paper not only investigates the relationship between the rail’s dynamic characteristics and the longitudinal stress, but also provides a feasible method for test longitudinal stress of continuous welded rail track.
The Analysis and Experiment on Key Technologies of Structural Design of Cap Beams of Highway Bridges
Authors: Xue Xing Wei , Yuan Hong , Li Shan Qing
Published: September 2011

In the paper, two key technologies of cap beams of highway bridges are studied, and the reductions of the bending moment on a pillar top and the lateral loading of live one are calculated and done experimental research. For the reduction problem of the bending moment on a pillar top, we build a three-dimensional entity model by ANSYS, and extract the bending moment of cap beams by the method of using track variable operation in post-treatment. Comparing the results of three-dimensional entity model with that of measurement of cap beams of a bridge in Zhuhai, it reveals that the reduction theory of the bending moment on an intermediate supporting of continuous beams can be applicable. For the lateral loading problem of the live load on cap beams, a new delivery method for the live load on cap beams is proposed. The transferring method is more conform to actual structure.
Study on the Effects of Joints on Tunnel Blasting
Authors: Zhou Neng Juan , Nie Lei , Shen Shi Wei , Zhang Min
Published: September 2011

In the smooth blasting of the tunnel, many studies indicate that the effects of joints on blasting are over than the nature of the rock itself. By analyzing the effects of joints on the strength of blasting rock, the rock surge impedance and the stress propagation, six kinds of effects of joints on blasting rock are summarized. Through the actual blasting engineering, the phenomenon of over-under break which is produced by joints is discussed. Meanwhile, the blasting effectiveness is analyzed.
A Numeric Analyses Method and Application of Loess Collapse Deformation
Authors: Li Rong Jian , Fan Liu Ming , Zheng Wen , Che Gao Feng
Published: September 2011

The collapse settlement of loess foundation is one of issues in engineering which need to be solved. Firstly, a finite element program was developed and the computational function of collapse deformation was implemented based on chord modulus method. Then, the comparison of the measured collapse settlement in a loading plate test and the computational collapse settlement based on the finite element were analyzed. The computational results show that the nonlinear finite element method based on the chord modulus should be recommended to evaluate the collapse deformation, owing to its potential application that it may consider the collapse deformation field of the whole collapsible loess foundation.
Study of Modal Parameter Identification from Ambient Vibration on a Deep Radial Gate
Authors: Cai Yuan Qi , Zhang Ke
Published: September 2011

In the engineering background of the prototype test of a deep radial gate on three gorges dam, two methods are provided for the modal parameter identification of the radial gate, one is applying operation modal analysis (OMA) to a gate which is under flood discharge, the other one is applying experiment modal analysis (EMA) to a inactive gate with some other gates under flood discharge. This paper is based on the feasibility study on the former method. We use the natural excitation technology (NExT) combined with the eigensystem realization algorithm (ERA) to determine the dynamic characteristics of a gate. Displacement data at 7 locations were processed using NExT-ERA to extract the natural frequency and associated damping ratio. The results show the effectiveness of this modal identification methodology and the possibility of implementing it on other hydraulic structure.
Structural Crack Detection Using Hilbert-Huang Transform Method and Wavelet Analysis
Authors: Liu Long , Dong Da Shan
Published: September 2011

Crack detection, Hilbert–Huang transform, Wavelet analysis Abstract. This paper illustrates the feasibility of the Hilbert–Huang transform (HHT) as a signal processing tool for detecting structural cracks. HHT is a promising method to extract the properties of nonlinear signals. However the HHT has some shortcomings, for example some undesirable pseudo-IMFs and multi-component IMF. The crack detection method based on the wavelet analysis and HHT is proposed to analyze response signals: the wavelet analysis is used to decompose the signal into a set of narrow band signals prior to the HHT. Then, a screening process is conducted to remove unrelated IMFs. By comparing the IMFs’ instantaneous amplitudes, the existence of structural crack is detected. Finally, the experiment results of the cantilever beams prove the reliability of this method.
The Design of Simulation Signal Source for Fish Torpedo Testing Based on DSP
Authors: Hao Niu Jun , Hu Cong , Hua Yin Xian , Yu Zhang Jing
Published: September 2011

Simulation signal source is applied to simulate sonar target signals in performance testing and guarantee maintenance of the torpedo. In this paper, the working principle of a simulation signal source for torpedo testing is described. USB bus communication interface and method of hardware designing are discussed in detail, and finally the software design of simulated signal source is analyzed. Experiments show that the simulation signal source can achieve a variety of signal modulation, superimposed, arbitrary waveform signals, meeting the need of the torpedo test.
Research on Photolysis of Steroid Estrogens in Aquatic System
Authors: He Ya Qin , Xu Gang , Tang Liang , Qian Dong Ying , Ren Lai Tang , Hu Gu Yu , Lei Jian Qiu , Wu Ming Hong
Published: September 2011

Estrogens such as estrone (E1), 17β-estradiol (E2) and estriol (E3) which are excreted by humans and animals or synthetic compounds such as 17α-ethinylestradiol (EE2) are a group of biologically active compounds that are synthesized from cholesterol and have a steroid ring in common. Steroid estrogens harm to organisms at very low concentrations with much more endocrine function than other EDCs. Obviously, it is an important issue to explore their degradation mechanisms and effective methods. In the present studies, 17β-estradiol (E2) and 17α-ethinylestradiol (EE2) were used as target compounds, and the photodegradation of them were investigated in aqueous solution using natural sunlight produced using a xenon lamp, or ultraviolet light via a Hg lamp.
Effect of Limestone Powders on Compressive Strength and Setting Time of Portland-Limestone Cement Pastes
Authors: Thongsanitgarn Pailyn , Wongkeo Watcharapong , Sinthupinyo Sakprayut , Chaipanich Arnon
Published: September 2011

In this study limestone powders with different particle sizes of 5, 10 and 20 μm were used to replace a part of Portland cement in different replacement levels to produce Portland-limestone cement pastes. The percentages of limestone replacement are 0, 5, 7.5, 10, 12.5, 15 and 20% by weight. The effect of fineness and the amount of limestone powders on compressive strength and setting time are investigated. It has been established that limestone replacement causes reduce the compressive strength due to the dilution effect, but it can reduce energy consumption and CO2 emission in cement manufacturing. The fineness of limestone powder used has influence on the observed compressive strength values. From the standard consistency results, it seems that limestone has no effect on water requirement compared to Portland cement. Moreover, the increase in level of fine particles would require much water. Both initial and final setting times were decreased with an increase in the amount of limestone. Furthermore, at the same level replacement, the cement pastes using 5 μm of limestone show lower setting time than those using 10 and 20 μm, respectively.
Study on Biological Fixation of High-Concentration CO2 Using Chlorella Pyrenoidosa
Authors: Yang Qi Peng , Wang Xiu Lin , Shi Xiao Yong , Li Ke Qiang , Yue Li Hong
Published: September 2011

CO2 emissions have serious impact on the world economy, especially at high-concentration. Green algae are known to have a tolerance to high CO2 level. In this paper, the rate of CO2 fixation using Chlorella Pyrenoidosa was analyzed in different environments. 1) Chlorella Pyrenoidosa fixed CO2 slowly in air, while this alga could rapidly grow in high-concentration CO2 until CO2 level was beyond 10%. At 25% CO2, the rate of CO2 fixation was lower than that at 10% CO2, but still 1.18 times as higher as in air. 2) At lower initial inoculation density of Chlorella Pyrenoidosa, its growth rate was relatively high but the rate of CO2 fixation was low. When initial inoculation density beyond 0.187×108cells/ml, the average rate of CO2 fixation was ranged from 2.786 gCO2/L·d to 2.847 gCO2/L·d. 3) During the five days, the average rate of CO2 fixation was 3.044 gCO2/L·d in NaNO3 resource. When NH4Cl or NaNO2 is regarded as N resource, the rate of CO2 fixation was almost neglectable.
Desaltation of the Polysaccharide of Nostoc Flagelliforme with Radial Flow Chromatography
Authors: Yue Si Jun , Jia Shi Ru , Dai Yu Jie , Guo Wei , Wang Jing Wen , Xue Feng Feng
Published: September 2011

.The process for the desaltation of the polysaccharide from the mixotrophic liquid culture of Nostoc flagelliforme with radial flow chromatography (RFC) column packed with Sephadex G-100 gel was investigated. The RFC column having 7.7 cm of bed length and 229.6 cm3 of bed volume was used in this study. The effects of some operating factors such as the sampling weight, the flow rate of eluent on the desaltation efficiency were examined. It was found that the separation efficiency increases with the decrease of sampling weight and flow rate of eluent. With 2.4 mg of sampling weight and 0.3 ml/min of flow rate of eluent, the salt content of polysaccharide was lowered from 90.42% to 2.36%. As a conclusion, this technique can be used to get rid of the eluant in the polysaccharide introduced by the ion exchange process.
Design and Fabrication of Planar-Type Micro-Hotplate with Si-Island Gas Sensor
Authors: Zhu Bin , Yin Chen Bo , Zhang Zi Li , Tao Chun Min , Dong Ning Ning
Published: September 2011

A gas sensor with planar-type micro-hotplate (MHP) with Si-island was designed and fabricated in this paper. The sensor was fabricated simply by using only three masks for the lithography process. The temperature distribution across the sensitive film was simulated and analyzed using ANSYS. A uniform temperature distribution was obtained after added Si-island. The SnO2 sensitive film was deposited through sol-gel spin-coating method and showed reasonable gas-sensing properties to hydrogen at 300°C.
Dynamic Modeling and Vibration Control of a Space Flexible Manipulator Using Piezoelectric Actuators and Sensors
Authors: Lou Jun Qiang , Wei Yan Ding
Published: September 2011

This paper concerns the dynamic modeling and vibration control of a space two-link flexible manipulator. Two types of PZT actuators, PZT shear actuator and torsional actuator, are used to suppress the bending-torsional-coupled vibration of the space manipulator. Using extended Hamilton’s principle and the finite element method, equations of motion of the space flexible manipulator with PZT actuators and tip mass are obtained. Based on modal analyze theory, the state space model of the system is then used to design the control system. A linear quadratic regulator (LQR) controller is designed to achieve vibration suppression of the space manipulator system. From the numerical results, we can get that the proposed controller has a suitable and efficient performance suppressing the bending-torsional-coupled vibration of the space two-link flexible manipulator.
Use the Combination Finite Element Method to Solve the Crack Cylinder of the Torsion Problem
Authors: Tang Xin Yan
Published: September 2011

Based on Muskhelishvili’s theoretical expressions of the Saint-Venant’s problem, using the combination of Crack3D code and Ansys software, a new combination finite element method to calculate the Saint-Venant’s torsion problem including crack is proposed. In order to illustrate its application, the numerical examples for a torsion cylinder with crack are given and the numerical results are satisfactory.
2-Dimensional Holospectrum Based Fault Detection of Rotor
Authors: Ming Ting Feng , Zhang Xiao Hai
Published: September 2011

Holospectrum is the spectrum analysis technique which synthesizes the information of the phase, amplitude and frequency. Firstly, the features of the 2-demensional holospectrum were analyzed through the simulating calculation. Secondly, the application of two spectrum correction methods, the phase difference and interpolation method, in the 2-demensional holospectrum technique was discussed respectively. And the result indicates that the former method has better effect for improving the precision of the sine coefficient, the cosine coefficient and the eccentricity. At the end of the paper the 2-demensional holospectrum technique combined with the phase difference method was used to detect three kinds of faults in a multi-functional rotor test rig and the good experimental result was gained.
Investigation of Dynamic Magnetic Fluid Seal Wear Process in Utility Water Environment
Authors: Szydło Zbigniew , Szczech Marcin
Published: September 2011

Serious problems arise when the magnetic fluid seal technology is needed to use in assemblies working in water or other liquid environment. Some efforts have been up to time made to design hybrid, two stage sealing structures with shields or mechanical seals used as protection measures to the magnetic fluid seal. Anyway, earlier or later there is always problem with direct contact between magnetic fluid and the environmental liquid. In the paper are presented results of experiments carried out with one stage rotating magnetic fluid seal operating in an direct contact with utility water. The special test procedures have been elaborated and practically used, with the aim to define main characteristics of magnetic fluid seals and to simplify experiments. These characteristics were: critical pressure,critical motion velocityandworking lifeof the seal. Four grades of commercial, silicon based magnetic fluids of hydrophobic properties were tested in a single stage sealing system. The results of tests are presented in the form of tables and diagrams. It is concluded that hydrophobic commercial magnetic fluids could be efficiently used in rotating shaft seals however within limited and rather low range of motion velocity.
Hydrogen Sensing Properties of Dye-Sensitized TiO2 Nanotube Array
Authors: Huang Liang , Ling Yun Han , Zhuo Yu Qing , Ren Fu Jian
Published: September 2011

A dye-sensitized TiO2 nanotube array (DST) was fabricated by electrochemical anodization in an aqueous organic electrolyte and immersed into ethanol containing N719 dye. The crystal phase and microstructure of the TiO2 nanotube array (TNTA) were characterized by X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). The UV-Vis spectra of the DST were characterized by diffuse reflectance spectra (DRS). The hydrogen sensitivity of the as-prepared sample was tested at room temperature under Xe-lamp (simulated solar light) irradiation. It was found that the sensor was highly sensitive to low concentrations of hydrogen as an application in air quality control.
FT-IR Study on Early-Age Hydration of Alkali-Activated Slag Cement
Authors: Fang Yong Hao , Lu Zheng Long , Wang Zhong Li
Published: September 2011

The hydration process of alkali-activated slag cement, especially at early-age, was studied by FT-IR, compared with that of Portland cement. The results show that during the hydration of alkali activated slag cement, two processes have taken place, the dissolution of Al3+ from the slag and then the recombination of Al3+ ions with the silicate anions. The former associated with the break of the glass network of slag and the later with the re-polymerization of the silicate and aluminosilicate anions. The rate of break of the glass network increases with the dosage of water glass, which completed in 24 h when the dosage of the water glass solution equivalent to Na2O exceeds 6% of the slag powder. It is confirmed by the IR study that Ca(OH)2 is absent in the hardened alkali activated slag cement paste.
Effect of EDM Conditions on Surface Residual Stress of Cr12MoV Steel
Authors: Li Xiao Song , Cai An Hui , Zeng Ji Jie
Published: September 2011

In this paper, surface residual stress in the cold working tool steel (Cr12MoV) by EDM was investigated by X-350 X-ray residual stress analyzer and method of DJP-2 electrolytic polishing instrument to remove layer by layer in the different EDM conditions. The results show that the distribution of surface residual stress generated not only by the peak discharge current and pulse width, but also by pulse interval. The same depth from the surface, residual stress of material after hardening is larger than the residual stress after annealing, With the different combination of tool electrode and work-piece material, the form of the discharge between two electrodes and the proportion of energy put between two electrodes are different, surface residual stress are also different. Different processing liquid for processing, the depth of residual stress generated is much the same, but closer to the surface, the worse the cooling capacity (quench degrees) and surface physical properties of processing fluids, the greater the residual stress. EDM, the generation and control of the surface residual stress depends on the choice such as processing power criteria, work-piece material, electrode materials and processing liquid. Surface residual stress after processing can be used to eliminate high-temperature heat treatment.
The Effect of Square Wave AC Parameters on Weld Forming Performance
Authors: Cheng F.J. , Zhang J.Y. , Wang Dong Po , Wu S.P.
Published: September 2011

The effects of weld current, voltage, frequency and duty cycle on weld forming performance were investigated in SAW (Submerged Arc Welding) with square wave AC mode. The results showed that the penetration increased with the decrease of frequency and increase of duty cycle, but weld width showed the opposite change tendency. Furthermore, some experiments were implemented to analyze the effect of wire extension length and arc voltage on bead appearance. All of these experimental data could provide proper parameters for the lead arc and the trail arc in tandem SAW using square wave AC and also testified square wave AC was preferred over DC and traditional 50Hz AC. The square wave AC power source could be applied widely in tandem SAW.
Balance, Sensorimotor, and Cognitive Performance in Long-Year Expert Senior Ballroom Dancers
Authors: Kattenstroth Jan-Christoph , Kalisch Tobias , Kolankowska Izabela , Dinse Hubert R.
Published: September 2011

Physical fitness is considered a major factor contributing to the maintenance of independent living and everyday competence. In line with this notion, it has been shown that several years of amateur dancing experience can exert beneficial effects not only on balance and posture but also on tactile, motor, and cognitive functions in older people. This raises the question of whether an even more extensive schedule of dancing, including competitive tournaments, would further enhance these positive effects. We therefore assessed posture, balance, and reaction times, as well as motor, tactile, and cognitive performance in older expert ballroom dancers with several years of competitive experience. We found substantially better performance in the expert group than in the controls in terms of expertise-related domains like posture, balance, and reaction times. However, there was no generalization of positive effects to those domains that were found to be improved in amateur dancers, such as tactile and cognitive performance, suggesting that there might be an optimal range of intervention intensity to maintain health and independence throughout the human lifespan.
Anaesthetic Considerations in Paediatric Myasthenia Gravis
Authors: Masters Oliver William , Bagshaw Oliver N.
Published: September 2011

Myasthenia gravis is of particular interest to anaesthetists because of the muscle groups affected, the pharmacology of the neuromuscular junction, and interaction of both the disease and treatment with many anaesthetic drugs. Anaesthetists may encounter children with myasthenia either to facilitate treatment options or to institute mechanical ventilation in the face of a crisis. This paper reviews the literature pertaining to the pathophysiology and applied pharmacology of the disease and explores the relationship between these and the anaesthetic management. In addition to illustrating the tried-and-tested techniques, some newer management options are explored.
A Novel ESRRB Deletion Is a Rare Cause of Autosomal Recessive Nonsyndromic Hearing Impairment among Pakistani Families
Authors: Lee Kwanghyuk , Khan Saadullah , Ansar Muhammad , Santos-Cortez Regie Lyn P. , Ahmad Wasim , Leal Suzanne M.
Published: September 2011

Mutations in the estrogen-related receptor beta (ESRRB) gene is the underlying cause of autosomal recessive nonsyndromic hearing impairment (ARNSHI) due to the DFNB35 locus which maps to 14q24.3. A genome scan of a large consanguineous Pakistani pedigree with ARNSHI established linkage with a maximum multipoint LOD score of 4.2 to the 14q24 region and the region of homozygosity contained the ESRRB gene. Sequencing of the ESRRB gene using DNA samples from hearing-impaired family members uncovered a novel three-nucleotide deletion c.1018_1020delGAG (p.Glu340del). The deletion segregates with hearing impairment in the pedigree and was not observed in 500 control chromosomes. The deletion of glutamic acid residue occurs in the ligand-binding domain of ESRRB protein. It is expected that the deletion affects the ligand-binding activity of the domain in ESRRB, which leads to the ARNSHI.
Molecular Investigation of Pediatric Portuguese Patients with Sensorineural Hearing Loss
Authors: Nogueira Célia , Coutinho Miguel , Pereira Cristina , Tessa Alessandra , Santorelli Filippo M. , Vilarinho Laura
Published: September 2011

The understanding of the molecular genetics in sensorineural hearing loss (SNHL) has advanced rapidly during the last decade, but the molecular etiology of hearing impairment in the Portuguese population has not been investigated thoroughly. To provide appropriate genetic testing and counseling to families, we analyzed the whole mitochondrial genome in 95 unrelated children with SNHL (53 nonsyndromic and 42 syndromic) and searched for variations in two frequent genes, GJB2 and GJB6, in the non-syndromic patients. Mutations in mtDNA were detected in 4.2% of the cases, including a hitherto undescribed change in the mtDNA-tRNATrp gene (namely, m.5558A>G). We also identified mono- or biallelic GJB2 mutations in 20 of 53 non-syndromic cases and also detected two novel mutations (p.P70R and p.R127QfsX84). Our data further reinforce the notion that genetic heterogeneity is paramount in children with SNHL.
In Vitro Enhanced Sensitivity to Cisplatin in D67Y BRCA1 RING Domain Protein
Authors: Atipairin Apichart , Ratanaphan Adisorn
Published: September 2011

BRCA1 is a tumor suppressor protein involved in maintaining genomic integrity through multiple functions in DNA damage repair, transcriptional regulation, cell cycle checkpoint, and protein ubiquitination. The BRCA1-BARD1 RING complex has an E3 ubiquitin ligase function that plays essential roles in response to DNA damage repair. BRCA1-associated cancers have been shown to confer a hypersensitivity to chemotherapeutic agents. Here, we have studied the functional consequence of the in vitro E3 ubiquitin ligase activity and cisplatin sensitivity of the missense mutation D67Y BRCA1 RING domain. The D67Y BRCA1 RING domain protein exhibited the reduced ubiquitination function, and was more susceptible to the drug than the D67E or wild-type BRCA1 RING domain protein. This evidence emphasized the potential of using the BRCA1 dysfunction as an important determinant of chemotherapy responses in breast cancer.
C1 Esterase Inhibitor (Human) for the Treatment of Acute Hereditary Angioedema
Authors: Valle Solange Oliveira Rodrigues , França Alfeu Tavares , Campos Regis A. , Grumach Anete Sevciovic
Published: September 2011

Hereditary angioedema (HAE) is a relatively rare disease characterized by acute episodes of swelling. These swellings can be disfiguring, painful and life-threatening. Since the symptoms occur in different areas and most patients experience a delay in their diagnosis, resulting in unnecessary suffering and dangerous situations. HAE can have a tremendous impact on the quality of life. The major genetic deficiency in this disorder is either an absent or nonfunctional C1INH which regulates the complement, fibrinolitic, kalikrein and plasmin pathways.
Full-Length Metallic Double J Stents: A Review of Resonance® Stents
Authors: Newton Mark R. , Brown James A.
Published: September 2011

Ureteral stricture, regardless of etiology, remains difficult to treat. Mainstays of therapy include polymeric double J stents and percutaneous nephrostomy tubes, each with respective complications. Multiple retrospective studies have now been published using the Resonance metallic double J stent, which is the focus of this review. A literature search was completed utilizing Pub Med. Key words included metallic stent, Resonance stents, and ureteral stricture. All identified papers were included. The stent is generally well tolerated, with infections, hematuria, and voiding symptoms requiring removal in 0% –14% of patients. Stents remained in place for mean of 4 to 9.4 months with the exception of a single study evaluating ureteroenteric strictures, where average duration was 21 days. In most studies a subset of patients kept the stent in situ for > 12 months, indicating that for some, the Resonance stent is a viable option, though predicting which patients will do well remains difficult.
Interfacial Characteristics of Carbon Nanotube-Polyethylene Composites Using Molecular Dynamics Simulations
Authors: Zhang Z. Q. , Ward D. K. , Xue Y. , Zhang H. W. , Horstemeyer M. F.
Published: September 2011

The rate-dependent interfacial behavior between a carbon nanotube (CNT) and a polyethylene (PE) matrix is investigated using molecular dynamics (MD) simulations. Various MD simulations were set up to determine the “size” effects on the interfacial properties, such as the molecular weight, or the length of the polymer, the diameter of the CNT, and the simulation model size. The interfacial rate-dependency was probed by applying various relative sliding velocities between the CNT and the polymer. Two quantities, directly obtained from the MD simulations, described the interfacial properties: the critical interfacial shear stress (CISS) and the steady interfacial shear stress (SISS). The simulations show that the SISS was not sensitive to the simulation size. In addition, the CISS was dependent upon the combined factors of the variation in PE stiffness, induced by simulation size changes and the effect of the fixed boundaries of the simulation models. The CISS increases almost linearly with the relative sliding velocity of CNTs. Also, a linear relationship between the SISS and the CNT-sliding velocity is observed when the SISS drops below a critical value. A clear size scaling is observed as the CISS and SISS decrease with increasing CNT radius and increase with the increasing polymer chain length.
Disparities in the Clinical Encounter: Virginia's African American Children with Special Health Care Needs
Authors: Oswald Donald P. , Bodurtha Joann N. , Willis Janet H. , Gilles Donna L. , Christon Lillian M. , Ogston Paula L. , Tlusty Susan M.
Published: September 2011

This study analyzed Virginia data from the most recent National Survey of Children with Special Health Care Needs. Logistic regression models were run for six Maternal and Child Health Bureau core outcomes and included demographics, child characteristics, health care providers, and health care access variables as predictors. Race/ethnicity disparities were judged to be present if the race/ethnicity variable was a significant predictor in the final model. Examining the components of disparate outcomes, African American children were found to be less likely than their white counterparts to have a usual source for sick and preventive care and to have a personal doctor or nurse. Their parents were less likely to say that doctors spent enough time, listened carefully, were sensitive to values and customs, and made them feel like a partner. These findings emphasize the need to examine health care disparities at a state level in order to guide efforts at remediation.
Maternally inherited partial monosomy 9p (pter → p24.1) and partial trisomy 20p (pter → p12.1) characterized by microarray comparative genomic hybridization
Authors: Freitas Érika L. , Gribble Susan M. , Simioni Milena , Vieira Társis P. , Silva‐Grecco Roseane L. , Balarin Marly A. S. , Prigmore Elena , Krepischi‐Santos Ana C. , Rosenberg Carla , Szuhai Karoly , van Haeringen Arie , Carter Nigel P. , Gil‐da‐Silva‐Lopes Vera Lúcia
Published: September 2011

We report on a 17‐year‐old patient with midline defects, ocular hypertelorism, neuropsychomotor development delay, neonatal macrosomy, and dental anomalies. DNA copy number investigations using a Whole Genome TilePath array consisting, of 30K BAC/PAC clones showed a 6.36 Mb deletion in the 9p24.1–p24.3 region and a 14.83 Mb duplication in the 20p12.1–p13 region, which derived from a maternal balanced t(9;20)(p24.1;p12.1) as shown by FISH studies. Monosomy 9p is a well‐delineated chromosomal syndrome with characteristic clinical features, while chromosome 20p duplication is a rare genetic condition. Only a handful of cases of monosomy 9/trisomy 20 have been previously described. In this report, we compare the phenotype of our patient with those already reported in the literature, and discuss the role of DMRT, DOCK8, FOXD4, VLDLR, RSPO4, AVP, RASSF2, PROKR2, BMP2, MKKS, and JAG1, all genes mapping to the deleted and duplicated regions. © 2011 Wiley Periodicals, Inc.
Synthesis of fluorescent methoxy poly(ethylene glycol)‐b‐Poly(ethyl cyanoacrylate)–2‐(N‐carbazolyl) ethyl methacrylate copolymer via living oxyanion‐initiated polymerization
Authors: Lin Xiaona , Deng Liandong , Dong Anjie
Published: September 2011

The fluorescent amphiphilic block copolymer methoxy poly(ethylene glycol) (mPEG)‐b‐poly(ethyl cyanoacrylate) (PECA)–2‐(N‐carbazolyl) ethyl methacrylate (CzEMA) was synthesized via living oxyanion‐initiated polymerization. mPEG‐b‐PECA–CzEMA was characterized by gel permeation chromatography, 1H‐NMR, and Fourier transform infrared spectroscopy. The results indicate that the polymerization was well controlled with a narrow molecular weight distribution. The mPEG‐b‐PECA–CzEMA nanoparticles prepared by nanoprecipitation techniques showed a narrow size distribution with an average diameter of less than 100 nm. The mPEG‐b‐PECA–CzEMA exhibited a strong carbazole fluorescence. Furthermore, it was found that the fluorescence intensity of mPEG‐b‐PECA–CzEMA was sensitive to a change in solvent. The results indicate that a subtle change in the state of the polymer micellar association may have altered the state of carbazole groups, which was responsible for the fluorescence emission. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Making the case for the humanities in evaluation training
Authors: Smith Deborah A.
Published: September 2011

The author argues that evaluators who are comfortable with the interpretation of competing values—an ability that can be fostered by exposure to the humanities—might be able to contribute significant advances toward finding a better balance of methodologies in an ever‐more‐ambiguous world. This argument is made by describing a humanities‐informed evaluation graduate course. Black‐and‐white worldviews and one‐size‐fits‐all solutions are hard to reconcile in evaluation environments increasingly characterized by multiculturalism, complexity, and uncertainty. The author reflects on the place of value judgments in the graduate education of future evaluators, not as something to avoid, but as an opportunity to improve needed skills. © Wiley Periodicals, Inc., and the American Evaluation Association
Political psychology in evaluation: A theoretical framework
Authors: Perry S. Marshall
Published: September 2011

The author describes how political psychology, an emerging field that explores the intersection of political science and psychology, can help in conducting evaluations. For example, an evaluator might examine the validity of behavioral assumptions of programs, policies, or organizational mechanisms and people's motivations and subjective experiences within these contexts. An evaluator might also explore the normative orientations of programs and policies, for example, how target goals and implementers are politically framed in a positive or negative light. The author describes a framework for political psychology as applied to evaluation, a brief review of relevant literature and discussion of methodology, and an example of an evaluation informed by political psychology. © Wiley Periodicals, Inc., and the American Evaluation Association
En “gendering” evaluation: Feminist evaluation but “I am NOT a feminist!”
Authors: Bheda Divya
Published: September 2011

The author explores the information gained through interviewing 13 feminist evaluators to explore (a) possible reasons why many evaluators—who draw from feminist principles and research—choose not to identify as “feminist” in their evaluation practice and scholarship and (b) the potential gains and losses to not locating themselves as feminist evaluators. © Wiley Periodicals, Inc., and the American Evaluation Association
New evaluators addressing health disparities through community‐based evaluation
Authors: Schlueter Dara F.
Published: September 2011

The author explores challenges in assessing health issues among ethnic and racially diverse populations, especially those related to a lack of long‐standing relationships with community leaders, knowledge about the community and its needs, and sufficient funding to maintain lasting engagement within the communities of interest. One of the overarching goals of Healthy People 2010, to eliminate health disparities in the United States, has awarded much attention to the correlation between race/ethnicity and persistent and increasing health disparities among U.S. populations. Approaches for implementing and evaluating health interventions designed to address these disparities must be community based in order to identify feasible strategies for improving processes and outcomes among populations of interest. © Wiley Periodicals, Inc., and the American Evaluation Association
Sailing through relationships? On discovering the compass for navigating 21st‐century evaluation in the Pacific
Authors: White Paula , Boulton Amohia
Published: September 2011

Aotearoa New Zealand is a small bicultural island nation in the Pacific with a multicultural population, a context that poses unique challenges for new evaluators, as it does for our more experienced counterparts. As emerging evaluators, the key challenge we have faced is navigating relationships, at the interface between program funders and culturally diverse communities, with integrity, and to ensure meaningful, credible, and valid evaluation findings. Drawing on their early experiences, the authors discuss their discoveries on sailing through relationships toward evaluation that is “good.” © Wiley Periodicals, Inc., and the American Evaluation Association
The evolution of understanding: Positioning evaluation within a comprehensive performance management system
Authors: Price Kelci M.
Published: September 2011

Although performance management has become a common organizational practice, in many cases it has not resulted in substantial program improvement or organizational learning. The author discusses two issues related to performance management systems that are of key concern to evaluators: (a) evaluation is often excluded from these systems in favor of monitoring data, and (b) performance management systems tend to focus on the creation of data rather than its use. The author discusses the complementary roles of evaluation and monitoring data, and highlights some ways in which evaluation can help improve performance management systems. © Wiley Periodicals, Inc., and the American Evaluation Association
Utilizing emerging technology in program evaluation
Authors: Galen Matthew , Grodzicki Deborah
Published: September 2011

The force of fast‐paced technological growth and globalization influence today's organizational environments. Successful organizations have become more nimble and responsive to these environmental realities, while simultaneously managing increasingly complex informational needs. The success of program evaluations will depend on evaluators' abilities to leverage future technologies to produce and disseminate knowledge in an accessible and actionable form. The authors propose that the roles and responsibilities of the evaluator will shift as current evaluation approaches are adapted to make effective use of these technological tools. Specifically, the authors discuss evaluators' future roles as collaborators with design‐science practitioners, filterers and translators of information, and customizers of knowledge dissemination. © Wiley Periodicals, Inc., and the American Evaluation Association
Online learning programs: Evaluation's challenging future
Authors: Nord Derek
Published: September 2011

With the vast array of contextual factors, pedagogical approaches, models of implementation, and purposes of education and training related to online learning, educators, learners, and the general public alike are seeking answers regarding utility and effectiveness of online learning. This article identifies and responds to many of the challenges and issues related to the evaluation of online learning that will likely test evaluators in the years and decades to come. The author provides an early conceptualization of a comprehensive evaluation framework to focus evaluation on the many components of online learning rather than a narrow aspect. © Wiley Periodicals, Inc., and the American Evaluation Association
Phosphoinositide 3‐kinase inhibition enables retinoic acid‐induced neurogenesis in monolayer culture of embryonic stem cells
Authors: Kotasová Hana , Veselá Iva , Kučera Jan , Houdek Zbyněk , Procházková Jiřina , Králičková Milena , Pacherník Jiří
Published: September 2011

Retinoic acid (RA) is able to induce the differentiation of embryonic stem cells into neuronal lineages. The mechanism of this effect is unknown but it has been evidenced to be dependent on the formation of floating spheroids called embryoid bodies. Results presented here show that the inhibition of phosphoinositide 3‐kinase signaling pre‐determines mouse embryonic stem cells to RA induced neurogenesis in monolayer culture with no need of embryoid bodies formation. J. Cell. Biochem. 113: 563–570, 2012. © 2011 Wiley Periodicals, Inc.
Perinatal intermittent hypoxia alters γ‐aminobutyric acid: a receptor levels in rat cerebellum
Authors: Pae Eung‐Kwon , Yoon Audrey J. , Ahuja Bhoomika , Lau Gary W. , Nguyen Daniel D. , Kim Yong , Harper Ronald M.
Published: September 2011

Perinatal hypoxia commonly causes brain injury in infants, but the time course and mechanisms underlying the preferential male injury are unclear. Intermittent hypoxia disturbs cerebellar γ‐aminobutyric (GABA)‐A receptor profiles during the perinatal period, possibly responding to transient excitatory processes associated with GABAA receptors. We examined whether hypoxic insults were particularly damaging to the male rodent cerebellum during a specific developmental time window. We evaluated cerebellar injury and GABAA receptor profiles following 5‐h intermittent hypoxia (IH: 20.8% and 10.3% ambient oxygen, switched every 240 s) or room‐air control in groups of male and female rat pups on postnatal d 1–2, wk 1, or wk 3. The cerebella were harvested and compared between groups. The mRNA levels of GABAA receptors α6, normalized to a house‐keeping gene GAPDH, and assessed using real‐time reverse‐transcriptase PCR assays were up‐regulated by IH at wk 1, more extensively in male rats, with sex influencing the regulatory time‐course. In contrast, GABAA α6 receptor protein expression levels, assessed using Western blot assays, reached a nadir at wk 1 in both male and female rats, possibly indicating involvement of a post‐transcriptional mechanism. The extent of cerebellar damage and level of apoptosis, assessed by DNA fragmentation, were greatest in the wk 3 IH‐exposed group. The findings suggest partial protection for female rats against early hypoxic insult in the cerebellum, and that down‐regulation of GABAA receptors, rather than direct neural injury assessed by DNA fragmentation may modify cerebellar function, with potential later motor and other deficits.