bluuebunny/crossref_metadata_2025 huggingface dataset:
Effective Discrimination of Acoustic Emission Source Signals for Structural Health Monitoring
Authors: Kaphle Manindra , Tan Andy C.C. , Thambiratnam David P. , Chan Tommy H.T.
Published: July 2012

Acoustic emission (AE) is the phenomenon where stress waves are generated due to rapid release of energy within a material caused by sources such as crack initiation or growth. AE technique involves recording the stress waves by means of sensors and subsequent analysis of the recorded signals to gather information about the nature of the source. Though AE technique is one of the popular non destructive evaluation (NDE) techniques for structural health monitoring of mechanical, aerospace and civil structures; several challenges still exist in successful application of this technique. Presence of spurious noise signals can mask genuine damage-related AE signals; hence a major challenge identified is finding ways to discriminate signals from different sources. Analysis of parameters of recorded AE signals, comparison of amplitudes of AE wave modes and investigation of uniqueness of recorded AE signals have been mentioned as possible criteria for source differentiation. This paper reviews common approaches currently in use for source discrimination, particularly focusing on structural health monitoring of civil engineering structural components such as beams; and further investigates the applications of some of these methods by analyzing AE data from laboratory tests.
Health Monitoring of Buildings during Construction and Service Stages Using Vibration Characteristics
Authors: Moragaspitiya H. N. Praveen , Thambiratnam David P. , Perera Nimal J. , Chan Tommy H. T.
Published: July 2012

Columns and walls in buildings are subjected to a number of load increments during the construction and service stages. The combination of these load increments and poor quality construction can cause defects in these structural components. In addition, defects can also occur due to accidental or deliberate actions by users of the building during construction and service stages. Such defects should be detected early so that remedial measures can be taken to improve life time serviceability and performance of the building. This paper uses micro and macro model upgrading methods during construction and service stages of a building based on the mass and stiffness changes to develop a comprehensive procedure for locating and detecting defects in columns and walls of buildings. Capabilities of the procedure are illustrated through examples.
An Improved Method to Detect Damage Using Modal Strain Energy Based Damage Index
Authors: Wahalthantri B.L. , Thambiratnam D.P. , Chan T.H.T. , Fawzia S.
Published: July 2012

This paper presents two novel concepts to enhance the accuracy of damage detection using the Modal Strain Energy based Damage Index (MSEDI) with the presence of noise in the mode shape data. Firstly, the paper presents a sequential curve fitting technique that reduces the effect of noise on the calculation process of the MSEDI, more effectively than the two commonly used curve fitting techniques; namely, polynomial and Fourier's series. Secondly, a probability based Generalized Damage Localization Index (GDLI) is proposed as a viable improvement to the damage detection process. The study uses a validated ABAQUS finite-element model of a reinforced concrete beam to obtain mode shape data in the undamaged and damaged states. Noise is simulated by adding three levels of random noise (1%, 3%, and 5%) to the mode shape data. Results show that damage detection is enhanced with increased number of modes and samples used with the GDLI.
Location and Severity Identification of Notch-Type Damage in a Two-Storey Steel Framed Structure Utilising Frequency Response Functions and Artificial Neural Network
Authors: Samali Bijan , Dackermann Ulrike , Li Jianchun
Published: July 2012

This paper presents a vibration-based damage identification method that utilises damage fingerprints embedded in frequency response functions (FRFs) to identify location and severity of notch-type damage in a two-storey framed structure. The proposed method utilises artificial neural networks (ANNs) to map changes in FRFs to damage characteristics. To enhance damage fingerprints in FRF data, residual FRFs, which are differences in FRF data between the undamaged and the damaged structures, are used for ANN inputs. By adopting principal component analysis (PCA) techniques, the size of the residual FRF data is reduced in order to obtain suitable patterns for ANN inputs. A hierarchy of neural network ensembles is created to take advantage of individual characteristics of measurements from different locations. The method is applied to laboratory and numerical two-storey framed structures. A number of single notch-type damage scenarios of different locations and severities are investigated. To simulate field-testing conditions, numerically simulated data is polluted with white Gaussian noise of up to 10% noise-to-signal-ratio. The results from both numerical and experimental investigations show the proposed method is effective and robust for detecting notch-type damage in structures.
Determination of Embedment Depth of Timber Poles and Piles Using Wavelet Transform
Authors: Li Jianchun , Subhani Mahbube , Samali Bijan
Published: July 2012

This paper presents an investigation on the wave propagation in timber poles with Wavelet Transform (WT) analysis for identification of the condition and underground depth of embedded timber poles in service. Most of non-destructive testing (NDT) applications for timber poles using wave-based methods consider only single wave mode and no dispersion. However, for wave propagations in timber poles (damaged/undamaged), such simplification may not be correct, especially for broad band excitation using impulse impact. To investigate the problem, a 5m timber pole was investigated numerically and experimentally. A dispersion curve is generated from the numerical results to provide guidance on the velocity and wave mode selection. Continuous wavelet transform (CWT) is applied on the same signal to verify the presence of modes and to process data from experimental testing. The results are presented in both time domain and time-frequency domain for comparison. The results of the investigation showed that, wavelet transform analysis can be a reliable signal processing tool for NDT in terms of condition and embedment length determination.
A General Nonlinear System Identification Method Based upon Time-Varying Trend of Instantaneous Frequencies and Amplitudes
Authors: Yan Guirong , De Stefano Alessandro , Ou Ge
Published: July 2012

Nonlinear phenomena are widely encountered in practical applications. The presence of nonlinearity makes a system exhibit different dynamic behaviours from its linear counterpart. A typical example is that free-vibration frequencies of nonlinear systems are amplitude-dependent, resulting in the variation of free-vibration frequencies with time. Therefore, Fourier spectrum which has been widely used in linear systems cannot completely represent dynamic characteristics of nonlinear systems. On the contrary, the time-varying trend of instantaneous frequencies and vibration amplitudes can completely capture dynamic characteristics of nonlinear systems. In this study, a general system identification method based on curving-fitting the time-varying trend of instantaneous frequencies and amplitudes is proposed for nonlinear systems. Herein Hilbert transform is employed to extract instantaneous frequencies and amplitudes from the measured responses. By taking the relationships between instantaneous vibration characteristics and structural physical parameters as regression models, structural physical parameters can be estimated by a least-squares estimation or an optimization method. The combination of the instantaneous information in time domain and frequency domain leads to high accuracy of identification results. The determination of model structure of nonlinearities is solved by assuming a generalized model which involves as many types of nonlinearities as possible. The proposed method has been demonstrated by numerical simulations.
Damage Identification of Steel Beams Using Local and Global Methods
Authors: Wang Ying , Hao Hong
Published: July 2012

Structural condition monitoring methods can be generally classified as local and global. While the global method needs only a small number of sensors to measure the low-frequency structural vibration properties, the acquired information is often not sufficiently sensitive to minor damages in a structure. Local methods, on the other hand, could be very sensitive to minor damages but their detection range is usually small. To overcome the drawbacks and take advantage of both methods, an integrated condition monitoring system has been recently developed for structural damage detection, which combines guided wave and structural vibration tests. This study aims at finding a viable damage identification method for steel structures by using this system. First, a spectral element modelling method is developed, which can simulate both wave propagation and structural vibration properties. Then the model is used in updating analysis to identify crack damage. Extensive numerical simulations and model updating works are conducted. The experimental and numerical results suggest that simply combining the objective functions cannot provide better structural damage identification. A two-stage damage identification scheme is more suitable for identifying damage in steel beams.
Refinement of Backward Prediction Method for Reliable Artificial Intelligence-Based Bridge Deterioration Modelling
Authors: Lee Jaeho , Guan Hong , Loo Yew-Chaye , Blumenstein Michael
Published: July 2012

A deterioration model is the most critical component of a Bridge Management System (BMS). Artificial Intelligence (AI)-based bridge deterioration model has recently been developed to minimise uncertainties in predicting long-term performance of bridge structural elements. This model contains two components: (1) using Neural Network-based Backward Prediction Model (BPM) to generate unavailable historical condition ratings; and (2) using Time Delay Neural Network (TDNN) to perform long-term performance prediction of bridge structural elements. However new problems have emerged in the process of TDNN prediction. In this study, the BPM-generated condition ratings are used together with the actual overall condition ratings. The incompatibility between the two sets of data produces unreliable prediction outcomes during the TDNN process. This research therefore aims to introduce a new data processing procedure for BPM outcomes, by removing meaningless condition ratings that cause poor training outcomes for long-term prediction using TDNN. Consequently, the outcome of this study can improve accuracy of the current AI-based bridge deterioration model.
Spectral Element Modelling of Wave Propagation with Boundary and Structural Discontinuity Reflections
Authors: Wang Ying , Hao Hong , Zhu Xinqun , Ou Jinping
Published: July 2012

Spectral element method is very efficient in modelling high-frequency stress wave propagation because it works in the frequency domain. It does not need to use very fine meshes in order to capture high frequency wave energy as the time domain methods do, such as finite element method. However, the conventional spectral element method requires a throw-off element to be added to the structural boundaries to act as a conduit for energy to transmit out of the system. This makes the method difficult to model wave reflection at boundaries. To overcome this limitation, imaginary spectral elements are proposed in this study, which are combined with the real structural elements to model wave reflections at structural boundaries. The efficiency and accuracy of this proposed approach is verified by comparing the numerical simulation results with measured results of one dimensional stress wave propagation in a steel bar. The method is also applied to model wave propagation in a steel bar with not only boundary reflection, but also reflections from single and multiple cracks. The reflection and transmission coefficients, which are obtained from the discrete spring model, are adopted to quantify the discontinuities. Experimental tests of wave propagation in a steel bar with one crack of different depths are also carried out. Numerical simulations and experimental results show that the proposed method is effective and reliable in modelling wave propagation in one-dimensional waveguides with reflections from boundary and structural discontinuities. The proposed method can be applied to effectively model stress wave propagation for structural damage detection.
High molecular weight soft segment based polyethylene shape memory polymers
Authors: Ahmad Manzoor , Luo J. , Xu Ben , Purnawali Hendra , King Peter , Chalker Paul , Fu Yongqing , Huang Weimin , Miraftab Moshen
Published: July 2012

Shape memory polyurethanes (SMPUs) are typically synthesized using polyols of low molecular weight, Mw, and high hydroxyl number as it is believed that high density of cross-links in these polyols are essential for high performance shape memory polymers. In this study, polyethylene glycol (PEG-6000) with Mw ~ 6000 g/mol and low hydroxyl number (OH ~ 18 mg K OH/g) as the soft segment and diisocyanate as the hard segment were used to synthesize SMPUs. It revealed that although the PEG-6000 based SMPUs have lower maximum elongation at break (425%) and recovery stress than those of PCL-2000 polyol based SMPUs, they have much better shape recovery ratio (98%) and shape fixity (95%). Furthermore, these SMPUs showed a much shorter actuation time of <10sec for up to 85% shape recovery, much shorter than those low Mw SMPUs, clearly demonstrated their great potential for applications.
Simulative analysis of flow through exhaust manifold for improved volumetric efficiency of multi cylinder petrol engine
Authors: Pravin V. , Umesh K. , Rajagopal K. , Veena P.
Published: July 2012

In internal combustion engines, exhaust system plays a vital role in the improvement of the combustion efficiency. A good conditioned exhaust manifold increase the performance of the engine. The work is focused on reducing the backpressure in the exhaust manifold to increase the combustion efficiency using CFD. Flow through the exhaust manifold is analyzed using CFX with pressure and velocity parameters as boundary condition. The existing manifold is modified and the new design is analyzed. The results of new design are compared with the values of the existing model. Graphs are drawn for the new design and are compared with existing manifold. The decrease in back pressure is shown using contour and vector diagram. By comparing the existing and new design, the increase in efficiency is found.
Mechanical behavior and calculating methods of large diameter prestressed concrete cylinder pipe (PCCP)
Authors: Wang Yuliang , Li Yancang , Bi Yongqing
Published: July 2012

Prestressed Concrete Cylinder Pipe (PCCP) is a kind of high quality composite pipe, whose mechanical behavior is not uniform because of its complicated structure and work condition. The mechanical model is established in PCCP working stage, based on the elastic plane strain theory of axisymmetric multilayer cylinders and the mechanism of the ring-like strands action. Then the design method of prestress is put forward according to the crack control. The stress is analyzed with finite-element analysis in the condition of different hydraulic pressures, and also the method is amended compared with the finite-element analysis. It is indicated that the design method of prestress is reasonable compared with both domestic and international specifications.
Improved Genetic Algorithm and its application in optimization of frame structures
Authors: Zhou Shujing , Yang Beibei
Published: July 2012

To overcome the problems of premature convergence and lower local search ability of the Genetic Algorithm (GA), an improved GA based on the Fish Algorithm was proposed. The new algorithm can speed up the optimal and the cluster behavior of the GA with the ability to overcome the local maximum. Then the improved algorithm was applied to the optimization of the reinforced concrete frame structure. The optimization model was established with the objective of minimizing the cost of beams and columns. The total cost of the structure obtained from the algorithm was compared with that obtained using the fuzzy algorithm and found to be lower. Thus the improved GA is proven to be practical and efficient when used for the optimization of frame structures.
Conversations with the Marketplace: An application of Design Thinking and Sociodrama Action Methods in an Innovation Workshop
Authors: Wyman Gail , Holland Valerie , Yates Simeon
Published: July 2012

This paper describes the use of sociodrama action methods within a design thinking workshop created to support marketing planning for a new product innovation. Participants were a digital sector SME and researchers within a UK university knowledge transfer programme. The paper (1) discusses the theoretical foundations of design thinking and sociodrama; (2) presents a detailed case study of workshop co-development and delivery; and (3) reports the impacts for the client and the university. The authors assert that the discourse of design thinking enhances innovative, collaborative problem solving that improve exploration of possibilities for new product and service development as well as improved organizational business processes. Sociodrama methods assist facilitators by incorporating psychological, linguistic and biological elements to design thinking, leading to superior outcomes than simply from setting up a creative problem solving activity.
Pounding Damage to Buildings and Bridges in the 22 February 2011 Christchurch Earthquake
Authors: Chouw Nawawi , Hao Hong
Published: July 2012

This paper addresses the damage to buildings and bridges resulting from relative movements between adjacent structures observed by the authors from building inspections and in-the-field investigations in Christchurch and surroundings carried out two weeks after the devastating earthquake of 22 February 2011. Relative structural response is often initiated by the different dynamic characteristic of the participating structures. Pounding induced damage might occur when the closing relative response is larger than the gap between adjacent structures. In the Central Business District (CBD) of Christchurch City many adjacent buildings have inadequate gaps between them or in many cases even no gap. Consequently, a large number of buildings, already weakened by the previous main shock of 4 September 2010 and its several thousand aftershocks, suffered further damage due to the strong February aftershock. The reoccurrence of excessive soil liquefaction caused particularly heavy damage to bridge sites along Avon River as the spatially varying ground movements induced large relative movement of the ground surface.
Method to Analyze the Effect of the Shock-Wave Loading on Building Elements
Authors: Chernobryvko Marina V. , Vorobyov Yuriy S. , Kruszka Leopold
Published: July 2012

During designing of some modern industrial and civil buildings it is necessary to consider influence of the intensive impact-wave loadings. The strain rate deformation of building and structural elements takes place both in the elastic and in plastic stage. In such tasks, it is necessary take into account presence of finite deformations as well as dynamic properties of materials. The calculation of above nonlinear task, including dynamic stress-strain states in elements, is carried out by the method of finite differences. Thus, an adaptive net is used on space and temporal to co-ordinates. Accuracy of numerical simulation is verify on every step of calculation, and if necessary change of step is involved.
Design Concept for Local Damage of Concrete Plates Subjected to High Velocity Impact
Authors: Beppu Masuhiro , Miwa Koji , Itoh Masaharu , Katayama Masahide , Morita Takeshi , Suzuki Makoto
Published: July 2012

Local damage of concrete structures, i.e. spalling, scabbing and perforation, would occur when concrete structures are impacted by high velocity projectiles. To propose protective design of concrete structures against high velocity impact, failure mechanism of local damage of concrete plates should be investigated. The authors have studied on failure mechanism of the local damage through impact tests and numerical analyses. This study presents a design concept for the local damage of a concrete plate subjected to high velocity impact. In the design procedure, occurrence of scabbing is judged based on comparison between maximum impact load and scabbing resistant capacity of the concrete plate. Impact load history and penetration depth are calculated using the modified theoretical model, and scabbing resistant capacity is estimated by applying a modified formula for punching shear resistant capacity.
Numerical Modeling of the Impact with Structures of Tsunami Bores Propagating on Dry and Wet Beds Using the SPH Method
Authors: St-Germain Philippe , Nistor Ioan , Townsend Ronald
Published: July 2012

In this paper, the simulation of the impact with structures of tsunami-like bores rapidly advancing on dry and wet beds is performed using a three-dimensional numerical model based on the Smoothed Particle Hydrodynamics (SPH) method. Firstly, to validate the numerical model, physical experiments are simulated and a quantitative comparison between experimental and numerical results is presented. Secondly, numerical results of the propagation of bores on dry and wet beds are compared to the analytical solution of the shallow water equations. Furthermore, the resulting time-histories of the pressures and net force acting on a square column and a vertical wall due to the impact of these bores are compared qualitatively. To better understand the development of the hydrodynamic forces, a detailed analysis of the velocity field and of the water surface elevation is also incorporated. This study is part of a comprehensive interdisciplinary research program whose purpose is to help develop design guidelines for tsunami-prone structures.
Book Reviews
Authors: Domasin Adrienne , Rodriguez Norma L , Newth Tom von Logue , Wayant Chelsea
Published: July 2012

Arnheim for Film and Media Studies, Scott Higgins (ed.), (2011) New York: Routledge, 304pp., ISBN: 9780415801089 (pbk), $37.95, ISBN: 9780415801072 (hbk), $150.00

Directory of World Cinema: Russia, Birgit Beumers (ed.), (2011) UK: Intellect, 332pp., ISBN 978-1-84150-372-1
(pbk), $25.00

Nicholas Ray: An American Journey, Bernard Eisenschitz (trans. Tom Milne), (1st American edn, 2011) Minneapolis: University of Minnesota Press, 624pp., ISBN: 9780816676217 (pbk), $24.95 First published in translation by Faber & Faber, London, 1993; originally
published as Les vies de Nicholas Ray, Christian Bourgois Editeur et Longue Distance, 1990.

Nicholas Ray: The Glorious Failure of an American Director, Patrick McGilligan, (2011) New York: itbooks/ HarperCollins Publishers, 560pp., ISBN: 9780060731373 (hbk), $29.99, 9780062092342
(ebook), $14.99

Amélie, Isabelle Vanderschelden, (2007) Champaign, IL: University of Illinois Press, 114pp., ISBN: 0-252-07470-X (pbk), $21.00
Interactions Between the Kinetochore Complex and the Protein Kinase A Pathway inSaccharomyces cerevisiae
Authors: Ma Lina , Ho Krystina , Piggott Nina , Luo Zongli , Measday Vivien
Published: July 2012

The kinetochore is a large structure composed of multiple protein subcomplexes that connect chromosomes to spindle microtubules to enable accurate chromosome segregation. Significant advances have been made in the identification of kinetochore proteins and elucidation of kinetochore structure; however, comparatively little is known about how cellular signals integrate with kinetochore function. In the budding yeast Saccharomyces cerevisiae, the cyclic AMP protein kinase A signaling pathway promotes cellular growth in response to glucose. In this study, we find that decreasing protein kinase A activity, either by overexpressing negative regulators of the pathway or deleting the upstream effector Ras2, improves the viability of ipl1 and spc24 kinetochore mutants. Ipl1/Aurora B is a highly conserved kinase that corrects attachment of sister kinetochores that have attached to the same spindle pole, whereas Spc24 is a component of the conserved Ndc80 kinetochore complex that attaches directly to microtubules. Unexpectedly, we find that kinetochore mutants have increased phosphorylation levels of protein kinase A substrates, suggesting that the cyclic AMP protein kinase A signaling pathway is stimulated. The increase in protein kinase A activity in kinetochore mutants is not induced by activation of the spindle checkpoint or a metaphase delay because protein kinase A activity remains constant during an unperturbed cell cycle. Finally, we show that lowering protein kinase A activity can rescue the chromosome loss defect of the inner kinetochore ndc10 mutant. Overall, our data suggest that the increased protein kinase A activity in kinetochore mutants is detrimental to cellular growth and chromosome transmission fidelity.
Evolutionary Recovery of a Recombinant Viral Genome
Authors: Springman Rachael , Kapadia-Desai Devanshi S , Molineux Ian J , Bull James J
Published: July 2012

It is well appreciated that the evolutionary divergence of genes and genomes from a common ancestor ultimately leads to incompatibilities if those genomes are hybridized. Far less is known about the ability and nature of compensatory evolution to yield the recovery of function in hybrid genomes. Here the major capsid gene of the bacteriophage T7 (40-kb dsDNA) was replaced with the homologous gene of either T3 or K11, each 22% different at the protein level from the T7 homolog. Initial fitness was moderately impaired for the T3 exchange, but the K11 exchange was not viable without a compensatory change in the T7 scaffolding protein. Subsequent adaptation of the transgenic phages led to nearly complete fitness recoveries. Compensatory changes were few, mostly in the transgene and its main interacting partner, the scaffolding protein gene. The large magnitude of fitness recovery with relatively few mutations suggests that the fitness costs of hybridizations and horizontal gene exchanges between moderately diverged genomes can potentially be short-lived through compensatory evolution.
Genetic Diversity and Population Structure of Chinese Foxtail Millet [Setaria italica(L.) Beauv.] Landraces
Authors: Wang Chunfang , Jia Guanqing , Zhi Hui , Niu Zhengang , Chai Yang , Li Wei , Wang Yongfang , Li Haiquan , Lu Ping , Zhao Baohua , Diao Xianmin
Published: July 2012

As an ancient cereal of great importance for dryland agriculture even today, foxtail millet (Setaria italica) is fast becoming a new plant genomic model crop. A genotypic analysis of 250 foxtail millet landraces, which represent 1% of foxtail millet germplasm kept in the Chinese National Gene Bank (CNGB), was conducted with 77 SSRs covering the foxtail millet genome. A high degree of molecular diversity among the landraces was found, with an average of 20.9 alleles per locus detected. STRUCTURE, neighbor-jointing, and principal components analyses classify the accessions into three clusters (topmost hierarchy) and, ultimately, four conservative subgroups (substructuring within the topmost clusters) in total, which are in good accordance with eco-geographical distribution in China. The highest subpopulation diversity was identified in the accessions of Pop3 from the middle regions of the Yellow River, followed by accessions in Pop1 from the downstream regions of the Yellow River, suggesting that foxtail millet was domesticated in the Yellow River drainage area first and then spread to other parts of the country. Linkage disequilibrium (LD) decay of less than 20 cM of genetic distance in the foxtail millet landrace genome was observed, which suggests that it could be possible to achieve resolution down to the 20 cM level for association mapping.
Comparison of Parallel High-Throughput RNA Sequencing Between Knockout of TDP-43 and Its Overexpression Reveals Primarily Nonreciprocal and Nonoverlapping Gene Expression Changes in the Central Nervous System of Drosophila
Authors: Hazelett Dennis J , Chang Jer-Cherng , Lakeland Daniel L , Morton David B
Published: July 2012

The human Tar-DNA binding protein, TDP-43, is associated with amyotrophic lateral sclerosis (ALS) and other neurodegenerative disorders. TDP-43 contains two conserved RNA-binding motifs and has documented roles in RNA metabolism, including pre-mRNA splicing and repression of transcription. Here, using Drosophila melanogaster as a model, we generated loss-of-function and overexpression genotypes of Tar-DNA binding protein homolog (TBPH) to study their effect on the transcriptome of the central nervous system (CNS). By using massively parallel sequencing methods (RNA-seq) to profile the CNS, we find that loss of TBPH results in widespread gene activation and altered splicing, much of which are reversed by rescue of TBPH expression. Conversely, TBPH overexpression results in decreased gene expression. Although previous studies implicated both absence and mis-expression of TDP-43 in ALS, our data exhibit little overlap in the gene expression between them, suggesting that the bulk of genes affected by TBPH loss-of-function and overexpression are different. In combination with computational approaches to identify likely TBPH targets and orthologs of previously identified vertebrate TDP-43 targets, we provide a comprehensive analysis of enriched gene ontologies. Our data suggest that TDP-43 plays a role in synaptic transmission, synaptic release, and endocytosis. We also uncovered a potential novel regulation of the Wnt and BMP pathways, many of whose targets appear to be conserved.
Hypertension in the Neonate
Authors: Dionne Janis M. , Flynn Joseph T.
Published: July 2012

Advances in our ability to identify, evaluate, and care for premature infants have lead to an increased awareness of hypertension in the NICU. A few recent studies have provided additional information on blood pressure values over the first month after birth and on other intrinsic and extrinsic factors that influence blood pressure in the neonatal period. The cause of hypertension in an affected neonate is usually obvious after a focused evaluation, with thromboembolism, kidney diseases, and chronic lung disease accounting for most cases. Individual clinical judgment must be relied on to decide on the most appropriate approach to treatment, with some infants needing either intravenous or oral antihypertensive medications. Remaining challenges include the lack of large-scale normative data, lack of evidence-based treatment recommendations, and a paucity of information on long-term outcome.
Nephrotoxic Medication Exposure and Acute Kidney Injury in Neonates
Authors: Zappitelli Michael , Selewski David T. , Askenazi David J.
Published: July 2012

Nephrotoxic medication use is common in neonates. In older children, the use of nephrotoxic medication is known to be one of the most common causes of acute kidney injury (AKI) and to be associated with increased morbidity. In critically ill neonates, AKI significantly complicates fluid and electrolyte management and may be an important risk factor for mortality. Better understanding of methods to avoid and detect the presence of nephrotoxicity may lead to more intelligent use of these medications, which could ultimately reduce the incidence of AKI and improve outcomes. In this work, we summarize why neonates are predisposed to drug nephrotoxicity, review the mechanisms and clinical picture of the most common nephrotoxic medications used in neonates (aminoglycosides, vancomycin, amphotericin B, acyclovir, nonsteroidal anti-inflammatory drugs, and radiocontrast agents), and discuss the roles of angiotensin-converting enzyme inhibitors and diuretics in nephrotoxicity. We also suggest ways to avoid and reduce the incidence and complications of neonatal nephrotoxicity.
Acute Kidney Injury in Neonates Requiring ECMO
Authors: Bridges Brian C. , Selewski David T. , Paden Matthew L. , Cooper David S. , Zappitelli Michael , Fleming Geoffrey M. , Askenazi David J.
Published: July 2012

Acute kidney injury (AKI) is common in neonates requiring extracorporeal membrane oxygenation (ECMO). Despite the strong association between AKI and worse outcome in patients requiring ECMO, there is considerable variation in how this morbidity is managed. We will address the pathophysiology and epidemiology of AKI in the neonatal ECMO patient. We will also discuss the indications and technical aspects of providing renal replacement therapy (RRT) for the neonate on ECMO.
USPSTF Perspective on Evidence-Based Preventive Recommendations for Children
Authors: Melnyk Bernadette Mazurek , Grossman David C. , Chou Roger , Mabry-Hernandez Iris , Nicholson Wanda , DeWitt Thomas G. , Cantu Adelita G. , Flores Glenn ,   for the US Preventive Services Task Force
Published: July 2012

The development and use of evidence-based recommendations for preventive care by primary care providers caring for children is an ongoing challenge. This issue is further complicated by the fact that a higher proportion of recommendations by the US Preventive Services Task Force (USPSTF) for pediatric preventive services in comparison with adult services have insufficient evidence to recommend for or against the service. One important root cause for this problem is the relative lack of high quality screening and counseling studies in pediatric primary care settings. The paucity of studies limits the development of additional evidence-based guidelines to enhance best practices for pediatric and adolescent conditions. In this article, we describe the following: (1) evidence-based primary care preventive services as a strategy for addressing important pediatric morbidities, (2) the process of making evidence-based screening recommendations by the USPSTF, (3) the current library of USPSTF recommendations for children and adolescents, and (4) factors influencing the use of USPSTF recommendations and other evidence-based guidelines by clinicians. Strategies to accelerate the implementation of evidence-based services and areas of need for future research to fill key gaps in evidence-based recommendations and guidelines are highlighted.
Regeneration of immature and mature embryos from diverse sets of wheat genotypes using media containing different auxins
Authors: Murín R. , Mészáros K. , Nemeček P. , Kuna R. , Faragó J.
Published: July 2012

The effect of explant type (immature vs. mature embryos) and two auxin types (2,4-dichlorophenoxyacetic acid vs. Dicamba) on the callogenesis and plant regeneration ability of 26 wheat cultivars was studied. In general, the callus induction, plant regeneration and shoot formation frequencies were higher in mature embryo-derived cultures as compared to immature ones on media originally developed for mature wheat embryo cultures. In both culture types, the auxin Dicamba was found to be more efficient, especially when mature embryos were cultured. The separation of means using Duncan’s multiple range test revealed the best in vitro response, in terms of the frequency of callus regeneration, in the cultivar Astella for both immature and mature embryo cultures. This cultivar gave very promising results, suggesting that it could be used in the future for further tissue culture investigations and as a donor material for genetic transformation experiments in wheat. Correlation analyses revealed significant similarities between the evaluated parameters within each group (immature and mature embryo-derived cultures). However, there were no significant correlations between these two groups for most of the parameters. This suggests that the mechanism of plant regeneration in the two in vitro regeneration systems (mature vs. immature embryo culture) may be different enough to hamper the development of an optimal plant regeneration protocol for use in both systems.
Effect of culture media on the growth and morphology of Hungarian Macrophomina phaseolina isolates
Authors: Csöndes I.
Published: July 2012

Macrophomina phaseolina (Tassi) Goidanich can cause serious yield losses in several plant species. Investigations were made on the colony morphology of fifty Macrophomina phaseolina isolates from Hungary, one from Spain and two from Serbia on six different culture media to detect differences between the isolates. The fungus exhibited the most intensive growth on maize-flour agar, followed by the Sabouraud-glucose, maltextract, potato-dextrose, Czapek-Dox and watery agar media. Investigations on the macromorphology of the isolates revealed different extents of aerial mycelia formation and differences in the zonal structure of microsclerotial formation on the individual media. One isolate (Mp 38) turned the Sabouraud-glucose agar medium pale pink. Investigations on the micromorphology of the cultures showed that the isolates also varied with respect to microsclerotial characters (size, shape and production of microsclerotia). The microsclerotia of this fungal pathogen had the greatest diameter (averaging 135.31 μm) on Sabouraud-glucose agar medium. This study was the first in Hungary to prove that Macrophomina phaseolina could be grown on nutrient-deficient watery agar, suggesting that it can tolerate a wide range of ecological circumstances.
Relationship between biotic stress tolerance and protective compounds in wheat genotypes
Authors: Kovács V. , Vida G. , Szalai G. , Janda T. , Pál M.
Published: July 2012

Large numbers of wheat genotypes were grown under field conditions and screened for biotic stress tolerance and certain protective compounds. It was found that both the salicylic acid and polyamine contents of the investigated genotypes varied over a wide range, while the antioxidant enzyme activities showed a similar pattern in the different genotypes. In order to investigate stress-induced changes in salicylic acid and polyamine contents, samples were collected from plants artificially inoculated with leaf rust (Puccinia triticina), on which natural powdery mildew [Blumeria graminis (DC.) Speer f. sp. tritici Em. Marchal] infection also appeared. Biotic stress mostly resulted in elevated levels of total salicylic acid and polyamines in all the genotypes. The activities of various antioxidant enzymes showed similar changes after infection regardless of the genotype. The investigation was aimed at detecting a relationship between the level of stress tolerance and the contents of protective compounds, in particular salicylic acid and polyamines.
High resolution molecular cytogenetic techniques in plants: Pachytene- and fibre-FISH
Authors: Linc G. , Molnár-Láng M.
Published: July 2012

Fluorescencein situhybridization (FISH) is the most versatile and accurate molecular cytogenetic technique for determining euchromatic-heterochromatic boundaries and the locations of repetitive and single-copy DNA sequences and of chromosome-specific BAC clones on chromosomes. The combination of cytogenetic and genetic methods yields a highresolution physical map. FISH allows direct mapping of specific DNA sequences inside the cell (interphase nuclei), along meiotic pachytene chromosomes and isolated chromatin (DNA fibres). The increased sensitivity of the technique and its ability to detect gene locations provide a powerful research tool for genetic and pre-breeding studies. FISH-based physical mapping plays an important role and is increasingly used for studies at the cytological level on the chromatin organization that controls gene expression and regulation. The present minireview describes some of the benefits of alternative FISH-based techniques and their application for studying plant chromosomes and genomes.
Human enterovirus 109 (EV109) in acute paediatric respiratory disease in Hungary
Authors: Pankovics Péter , Boros Ákos , Szabó Hajnalka , Székely Gyöngyi , Gyurkovits Kálmán , Reuter Gábor
Published: July 2012

Human enterovirus 109 (EV109) is a recently identified recombinant enterovirus in family Picornaviridae from acute paediatric respiratory illness in Nicaragua. EV109 have not been reported elsewhere. Our aims were the molecular detection and genetic analysis of EV109 from acute childhood respiratory infections in Hungary. Nasopharyngeal aspirates were collected from children under age of 10 years with acute respiratory infections treated in Department of Pulmonology, Kaposi Mór Teaching Hospital, Mosdós, Hungary. Samples were taken from 15 October to 15 May in two respiratory seasons 2005/2006 and 2006/2007. Samples were tested using EV109 specific VP1 primers by RT-PCR method. One (1.1%) of the 92 nasopharyngeal aspirates was positive for EV109 collected from a 2.5-year-old child in January, 2007. The main symptoms were dropping nose, fever (38.1°C), hard cough and wheezing associated with bronchitis and pneumonia. Based upon the VP1 gene region EV109 (L87/HUN/2007, JN900470) has 93% nucleotide identity and identical recombinant pattern to the prototype EV109. This is the first detection of the novel recombinant enterovirus, EV109, in Hungary (in Europe). This study supports the possibility that EV109 is able to cause acute respiratory infections, in addition, it might be plays a part in lower respiratory disease with hospitalization in children.
Single tube real time PCR for detection of Streptococcus pneumoniae, Mycoplasma pneumoniae, Chlamydophila pneumoniae and Legionella pneumophila from clinical samples of CAP
Authors: Nomanpour Bizhan , Ghodousi Arash , Babaei Toraj , Jafari Siroos , Feizabadi Mohammad
Published: July 2012

We designed a multiplex real time PCR for rapid, sensitive and specific detection ofStreptococcus pneumoniae, Legionella pneumophila, Chlamydophila pneumoniaeandMycoplasma pneumoniae. The study cases consisted of 129 patients with community acquired pneumonia (CAP). Bacteriological techniques were implemented for detection of the cultivable organisms. DNA were extracted from sputa, throat swabs, bronchoalveolar lavages and tracheal aspirates and used as templates in real time PCR. The primers and probes were designed forcbpA (S. pneumoniae),p1adhesin(M. pneumoniae), mip (L. pneumophila)andompA (C. pneumoniae). After optimization of real time PCR for every organism, the experiments were continued in multiplex in a single tube. Of 129 CAP specimens, the positive cultures included 14 (10.85%) forS. pneumoniae, 9 (6.98%) forL. pneumophilaand 3 (2.33%) forM. pneumoniae. Four specimens (3.10%) were positive forC. pneumoniaeby real time PCR. The sensitivity of our real time PCR was 100% for all selected bacteria. The specificity of the test was 98.26%, 98.34%, 100% and 100% forS. pneumoniae, L. pneumophila, M. pneumoniaeandC. pneumoniae, respectively. This is the first report on the use of multiplex real time PCR for detection of CAP patients in the Middle East. The method covers more than 90% of the bacterial pathogens causing CAP.
Survival of Campylobacter jejuni in chicken meat at frozen storage temperatures
Authors: Ivić-Kolevska Snezana , Miljković-Selimović Biljana , Kocić Branislava
Published: July 2012

The aim of this study was to determine the survival of Campylobacter jejuni in chicken meat samples at frozen temperatures and given length of incubation and to determine the impact of aerobic bacteria on the survival of C. jejuni. The chicken meat samples were inoculated with C. jejuni NCTC 11351 suspensions and stored in bags at temperatures of −20°C and −70°C. The mean value of C. jejuni from meat samples decreased from 7.52 log10 CFU/g after 30 minutes of incubation at ambient temperature, to 3.87 log10 CFU/g on the eighth week of incubation at −20°C, and to 3.78 log10 CFU/g at incubation at −70°C after the same incubation period. Both freezing temperatures, −20°C and −70°C, decreased the number of campylobacters. The presence of aerobic mesophilic bacteria did not influence the survival of C. jejuni in chicken meet samples. Keeping poultry meat at freezing temperatures is important for the reduction of C. jejuni, which has a strong influence on the prevention of occurrence of campylobacteriosis in humans.
Screening for phosphate solubilizing bacteria inhabiting the rhizoplane of rice grown in acidic soil in Bangladesh
Authors: Sarkar Animesh , Islam Tofazzal , Biswas Gokul , Alam Shohidul , Hossain Mikail , Talukder Nur
Published: July 2012

The objectives of the research were to isolate phosphate solubilizing bacteria (PSB) from the rhizoplane of rice (Oryza sativa L.) cv. BRRIdhan 29 cultivated in acidic soils of Tangail in Bangladesh and evaluate their performances in phosphate solubilization in both in vitro and in vivo conditions. A total of 10 bacterial strains were isolated and purified by repeated streak culture on nutrient agar medium. Upon screening, five isolates (OS01, OS03, OS07, OS08 and OS10) showed varying levels of phosphate solubilizing activity in agar plate and broth assays. Among them, the strain OS07 (B1) and two previously isolated PSB strains B2 and B3 were selected for evaluation for their performances in rice alone or in combination of TSP (triple super phosphate: P1) and rock phosphate (P2). Plant height and the number of tillers per plant were significantly increased by all PSB isolates when used in combination with TSP but PSB alone did not influence much on plant height and the number of tillers except B1. The levels of mineral nutrients content in rice plant tissues were generally increased by the application of the PSB in combination with TSP, while the performances of B1 isolate was superior in all aspects to B2 and B3 isolates.
Centrally symmetric convex bodies and sections having maximal quermassintegrals
Authors: Makai E. , Martini H.
Published: July 2012

Let d ≧ 2, and let K ⊂ ℝd be a convex body containing the origin 0 in its interior. In a previous paper we have proved the following. The body K is 0-symmetric if and only if the following holds. For each ω ∈ Sd−1, we have that the (d − 1)-volume of the intersection of K and an arbitrary hyperplane, with normal ω, attains its maximum if the hyperplane contains 0. An analogous theorem, for 1-dimensional sections and 1-volumes, has been proved long ago by Hammer (see [2]). In this paper we deal with the ((d − 2)-dimensional) surface area, or with lower dimensional quermassintegrals of these intersections, and prove an analogous, but local theorem, for small C2-perturbations, or C3-perturbations of the Euclidean unit ball, respectively.
On B-injectors of symmetric groups Sn
Authors: Al-Shomrani Mohammad , Al-Ali Bani-Ata Mashhour.
Published: July 2012

The aim of this paper is to describe the B-injectors of the symmetric group Sn by proving the following main theorem, using a shorter proof than that followed in [1] and [3]. In this note the proof is mainly based on the minimal proof concept, and the parts we have used from these two papers are referred to.Main Theorem:Let Ω be a finite set of size n, and let B ≦ SΩbe a B-injector of SΩ. Then

a)

If n ≢ 3 (mod 4) then B is a Sylow 2-subgroup of SΩ.

b)

If n ≡ 3 (mod 4) then B = 〈d〉 × T where d is a 3-cycle and T is a Sylow 2-subgroup of\documentclass{aastex}
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Limsup theorems and a uniform LIL for asymptotically negatively associated random sequences
Authors: Choi Yong-Kab , Hwang Kyo-Shin
Published: July 2012

In this paper we establish some limsup theorems and a generalized uniform law of the iterated logarithm (LIL) for the increments of the partial sums of a strictly stationary and asymptotically negatively associated (ANA) sequence of random variables.