WorldWideScience

Sample records for occurrence structural identification

  1. Dibenzylbutyrolactone Lignans - A Review of Their Structural Diversity, Biosynthesis, Occurrence, Identification and Importance.

    Science.gov (United States)

    Solyomváry, Anna; Beni, Szabolcs; Boldizsar, Imre

    2017-01-01

    Dibenzylbutyrolactone lignans represent a unique group of plant secondary metabolites with increasing significance in medicine. This review summarizes their structural characteristics and classification, as well as the biosynthesis starting in the chloroplast, and their supposed biological activity associated with plant defense mechanisms are also discussed. Over 85 natural dibenzylbutyrolactone lignans known to date and their corresponding plant sources are summarized herein for the first time, highlighting a taxon- and organ-specific accumulation of these compounds. The isolation strategies, applied analytical methods and pharmacological activities of dibenzylbutyrolactone lignans are also thoroughly reviewed. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  2. Familial pyrophosphate arthropathy. Occurrence and Crystal Identification.

    Science.gov (United States)

    Bjelle, A

    1981-01-01

    Hereditary pyrophosphate arthropathy has been observed in three Swedish families and in a few other caucasian populations. The inheritance is most probably autosomal dominant with a variable penetrance. The most severe cases have been found in homozygotes among isolates of immigrants in Slovakia and Chile. Studies on genetic and etio-pathogenetic factors in hereditary pyrophosphate arthropathy, and the utilization of new diagnostic techniques for crystal identification, are important approaches towards a further understanding of the disease.

  3. Structural Identification Problem

    Directory of Open Access Journals (Sweden)

    Suvorov Aleksei

    2016-01-01

    Full Text Available The identification problem of the existing structures though the Quasi-Newton and its modification, Trust region algorithms is discussed. For the structural problems, which could be represented by means of the mathematical modelling of the finite element code discussed method is extremely useful. The nonlinear minimization problem of the L2 norm for the structures with linear elastic behaviour is solved by using of the Optimization Toolbox of Matlab. The direct and inverse procedures for the composition of the desired function to minimize are illustrated for the spatial 3D truss structure as well as for the problem of plane finite elements. The truss identification problem is solved with 2 and 3 unknown parameters in order to compare the computational efforts and for the graphical purposes. The particular commands of the Matlab codes are present in this paper.

  4. Selective structural source identification

    Science.gov (United States)

    Totaro, Nicolas

    2018-04-01

    In the field of acoustic source reconstruction, the inverse Patch Transfer Function (iPTF) has been recently proposed and has shown satisfactory results whatever the shape of the vibrating surface and whatever the acoustic environment. These two interesting features are due to the virtual acoustic volume concept underlying the iPTF methods. The aim of the present article is to show how this concept of virtual subsystem can be used in structures to reconstruct the applied force distribution. Some virtual boundary conditions can be applied on a part of the structure, called virtual testing structure, to identify the force distribution applied in that zone regardless of the presence of other sources outside the zone under consideration. In the present article, the applicability of the method is only demonstrated on planar structures. However, the final example show how the method can be applied to a complex shape planar structure with point welded stiffeners even in the tested zone. In that case, if the virtual testing structure includes the stiffeners the identified force distribution only exhibits the positions of external applied forces. If the virtual testing structure does not include the stiffeners, the identified force distribution permits to localize the forces due to the coupling between the structure and the stiffeners through the welded points as well as the ones due to the external forces. This is why this approach is considered here as a selective structural source identification method. It is demonstrated that this approach clearly falls in the same framework as the Force Analysis Technique, the Virtual Fields Method or the 2D spatial Fourier transform. Even if this approach has a lot in common with these latters, it has some interesting particularities like its low sensitivity to measurement noise.

  5. Occurrence of monoethylmercury in the Florida Everglades: Identification and verification

    International Nuclear Information System (INIS)

    Mao Yuxiang; Yin Yongguang; Li Yanbin; Liu Guangliang; Feng Xinbin; Jiang Guibin; Cai Yong

    2010-01-01

    A few studies have reported the occurrence of monoethylmercury (CH 3 CH 2 Hg + ) in the natural environment, but further verification is needed due to the lack of direct evidence and/or uncertainty in analytical procedures. Various analytical techniques were employed to verify the occurrence of CH 3 CH 2 Hg + in soil of the Florida Everglades. The identity of CH 3 CH 2 Hg + in Everglades soil was clarified, for the first time, by GC/MS. The employment of the recently developed aqueous phenylation-purge-and-trap-GC coupled with ICPMS confirmed that the detected CH 3 CH 2 Hg + was not a misidentification of CH 3 SHg + . Stable isotope-tracer experiments further indicated that the detected CH 3 CH 2 Hg + indeed originated from Everglades soil and was not an analytical artifact. All these evidence clearly confirmed the occurrence of CH 3 CH 2 Hg + in Everglades soil, presumably as a consequence of ethylation occurring in this wetland. The prevalence of CH 3 CH 2 Hg + in Everglades soil suggests that ethylation could play an important role in the biogeochemical cycling of Hg. - A combination of various analytical techniques and stable isotope tracer experiments confirms monoethylmercury is present in Everglades soil.

  6. Structural system identification: Structural dynamics model validation

    Energy Technology Data Exchange (ETDEWEB)

    Red-Horse, J.R.

    1997-04-01

    Structural system identification is concerned with the development of systematic procedures and tools for developing predictive analytical models based on a physical structure`s dynamic response characteristics. It is a multidisciplinary process that involves the ability (1) to define high fidelity physics-based analysis models, (2) to acquire accurate test-derived information for physical specimens using diagnostic experiments, (3) to validate the numerical simulation model by reconciling differences that inevitably exist between the analysis model and the experimental data, and (4) to quantify uncertainties in the final system models and subsequent numerical simulations. The goal of this project was to develop structural system identification techniques and software suitable for both research and production applications in code and model validation.

  7. Structure, Biosynthesis, and Occurrence of Bacterial Pyrrolizidine Alkaloids.

    Science.gov (United States)

    Schimming, Olivia; Challinor, Victoria L; Tobias, Nicholas J; Adihou, Hélène; Grün, Peter; Pöschel, Laura; Richter, Christian; Schwalbe, Harald; Bode, Helge B

    2015-10-19

    Pyrrolizidine alkaloids (PAs) are widespread plant natural products with potent toxicity and bioactivity. Herein, the identification of bacterial PAs from entomopathogenic bacteria using differential analysis by 2D NMR spectroscopy (DANS) and mass spectrometry is described. Their biosynthesis was elucidated to involve a non-ribosomal peptide synthetase. The occurrence of these biosynthesis gene clusters in Gram-negative and Gram-positive bacteria indicates an important biological function in bacteria. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. The occurrence and source identification of bisphenol compounds in wastewaters.

    Science.gov (United States)

    Česen, Marjeta; Lenarčič, Kaja; Mislej, Vesna; Levstek, Meta; Kovačič, Ana; Cimrmančič, Bernardka; Uranjek, Nataša; Kosjek, Tina; Heath, David; Dolenc, Marija Sollner; Heath, Ester

    2018-03-01

    This study reports the occurrence of eight bisphenols (BPs): bisphenol AF (BPAF), bisphenol AP (BPAP), bisphenol B (BPB), bisphenol C (BPC), bisphenol E (BPE), bisphenol F (BPF), bisphenol S (BPS) and bisphenol Z (BPZ) in wastewaters (WWs). Sample preparation involved pre-concentration with SPE cartridges (Oasis HLB), followed by derivatization using N-(tert-butyldimethylsilyl)-N-methyltrifluoroacetamide with 1% tert-butyldimethylchlorosilane. Chemical analysis was based on gas chromatography-mass spectrometry. A validated method with limits of detection (LODs) at ngL -1 range was applied to WWs collected at five Slovene wastewater treatment plants (WWTPs) and WW inflows from industrial, commercial and residential sources entering the sewerage systems of two catchments (Domžale-Kamnik (DK) and Ljubljana (LJ)). The presence of all BPs was confirmed in three inflows in DK and two inflows in the LJ catchments. High cumulative concentrations of all BPs were determined in WW from food processing facilities (LJ: 3030ngL -1 and DK: 599ngL -1 ). A high detection frequency was observed in the WW from two textile cleaning companies (6 BPs for LJ and 8 BPs for DK). The analysis of WW from WWTPs revealed that only BPF (36.7ngL -1 ) and BPS (40.6ngL -1 ) were >LODs in the influents, whereas other BPs were detected also in the effluents. BPZ was found in the highest concentration (403ngL -1 at WWTP-DK). WW collected at this WWTP also contained the highest amount of BPE (238ngL -1 ). Although BPs removal could not be directly compared between the WWTPs, with the exception of BPAP and BPB in the case of two smaller WWTPs (6.39%-43.2%) bisphenols were in general highly removed (≥96.2%). Finally, levels of BPC>LOD are reported for first time (WWTP in the DK catchment: 1.01ngL -1 -11.8ngL -1 ; LJ inflow from food processing plant up to 2560ngL -1 ). Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  9. Quantile driven identification of structural derivatives

    OpenAIRE

    Andrew Chesher

    2001-01-01

    Conditions are derived under which there is local nonparametric identification of derivatives of structural equations in nonlinear triangular simultaneous equations systems. The attack on this problem is via conditional quantile functions and exploits local quantile independence conditions. The identification conditions include local analogues of the order and rank conditions familiar in the analysis of linear simultaneous equations models. The objects whose identification is sought are deriv...

  10. Identification and Damage Detection on Structural Systems

    DEFF Research Database (Denmark)

    Brincker, Rune; Kirkegaard, Poul Henning; Andersen, Palle

    1994-01-01

    A short introduction is given to system identification and damage assessment in civil engineering structures. The most commonly used FFT-based techniques for system identification are mentioned, and the Random decrement technique and parametric methods based on ARMA models are introduced. Speed...

  11. Identification of High Potential Bays for HABs Occurrence in Peninsular Malysia Using Palsar Remote Sensing Data

    Science.gov (United States)

    Pour, A. B.; Hashim, M.

    2016-09-01

    Increasing frequency, intensity, and geographic distribution of Harmful algal blooms (HABs) poses a serious threat to the coastal fish/shellfish aquaculture and fisheries in Malaysian bays. Rising in sea level, shoreline erosion, stresses on fisheries, population pressure, interference of land-use and lack of institutional capabilities for integrated management make major challenges. Recent investigations and satellite observations indicate HABs originated from specific coast that have favourable geographic, geomorphic and coastal geology conditions to bring the green macro algae from the coast offshore. Therefore, the identification of high HABs frequented bays using remote sensing and geology investigations in Malaysian waters is required to reduce future challenges in this unique case. This research implemented comprehensive geomorphic and coastal geology investigations combined with remote sensing digital image processing approach to identify Malaysian bays frequented with HABs occurrence in Malaysian waters territory. The landscape and geomorphological features of the Malaysian bays were constructed from the Phased Array type L-band Synthetic Aperture Radar (PALSAR) remote sensing satellite data combined with field observations and surveying. The samples for laboratory analysis were collected from the sediment stations with different distance across shorelines features and watersheds of the Johor Bahru estuary. This research identified that semi-enclosed bays such as Kuala Lumpur and Johor Bahru bays with connection to estuaries have high potential to be frequented with HABs occurrence.

  12. IDENTIFICATION OF HIGH POTENTIAL BAYS FOR HABs OCCURRENCE IN PENINSULAR MALYSIA USING PALSAR REMOTE SENSING DATA

    Directory of Open Access Journals (Sweden)

    A. B. Pour

    2016-09-01

    Full Text Available Increasing frequency, intensity, and geographic distribution of Harmful algal blooms (HABs poses a serious threat to the coastal fish/shellfish aquaculture and fisheries in Malaysian bays. Rising in sea level, shoreline erosion, stresses on fisheries, population pressure, interference of land-use and lack of institutional capabilities for integrated management make major challenges. Recent investigations and satellite observations indicate HABs originated from specific coast that have favourable geographic, geomorphic and coastal geology conditions to bring the green macro algae from the coast offshore. Therefore, the identification of high HABs frequented bays using remote sensing and geology investigations in Malaysian waters is required to reduce future challenges in this unique case. This research implemented comprehensive geomorphic and coastal geology investigations combined with remote sensing digital image processing approach to identify Malaysian bays frequented with HABs occurrence in Malaysian waters territory. The landscape and geomorphological features of the Malaysian bays were constructed from the Phased Array type L-band Synthetic Aperture Radar (PALSAR remote sensing satellite data combined with field observations and surveying. The samples for laboratory analysis were collected from the sediment stations with different distance across shorelines features and watersheds of the Johor Bahru estuary. This research identified that semi-enclosed bays such as Kuala Lumpur and Johor Bahru bays with connection to estuaries have high potential to be frequented with HABs occurrence.

  13. Multiscale global identification of porous structures

    Science.gov (United States)

    Hatłas, Marcin; Beluch, Witold

    2018-01-01

    The paper is devoted to the evolutionary identification of the material constants of porous structures based on measurements conducted on a macro scale. Numerical homogenization with the RVE concept is used to determine the equivalent properties of a macroscopically homogeneous material. Finite element method software is applied to solve the boundary-value problem in both scales. Global optimization methods in form of evolutionary algorithm are employed to solve the identification task. Modal analysis is performed to collect the data necessary for the identification. A numerical example presenting the effectiveness of proposed attitude is attached.

  14. Robust structural identification via polyhedral template matching

    DEFF Research Database (Denmark)

    Larsen, Peter Mahler; Schmidt, Søren; Schiøtz, Jakob

    2016-01-01

    Successful scientific applications of large-scale molecular dynamics often rely on automated methods for identifying the local crystalline structure of condensed phases. Many existing methods for structural identification, such as common neighbour analysis, rely on interatomic distances (or thres...... is made available under a Free and Open Source Software license....

  15. Nonparametric identification of copula structures

    KAUST Repository

    Li, Bo; Genton, Marc G.

    2013-01-01

    We propose a unified framework for testing a variety of assumptions commonly made about the structure of copulas, including symmetry, radial symmetry, joint symmetry, associativity and Archimedeanity, and max-stability. Our test is nonparametric

  16. System identification and structural health monitoring of bridge structures

    OpenAIRE

    Islami, Kleidi

    2013-01-01

    This research study addresses two issues for the identification of structural characteristics of civil infrastructure systems. The first one is related to the problem of dynamic system identification, by means of experimental and operational modal analysis, applied to a large variety of bridge structures. Based on time and frequency domain techniques and mainly with output-only acceleration, velocity or strain data, modal parameters have been estimated for suspension bridges, masonry arch bri...

  17. Modeling and identification in structural dynamics

    OpenAIRE

    Jayakumar, Paramsothy

    1987-01-01

    Analytical modeling of structures subjected to ground motions is an important aspect of fully dynamic earthquake-resistant design. In general, linear models are only sufficient to represent structural responses resulting from earthquake motions of small amplitudes. However, the response of structures during strong ground motions is highly nonlinear and hysteretic. System identification is an effective tool for developing analytical models from experimental data. Testing of full-scale prot...

  18. Nonparametric identification of copula structures

    KAUST Repository

    Li, Bo

    2013-06-01

    We propose a unified framework for testing a variety of assumptions commonly made about the structure of copulas, including symmetry, radial symmetry, joint symmetry, associativity and Archimedeanity, and max-stability. Our test is nonparametric and based on the asymptotic distribution of the empirical copula process.We perform simulation experiments to evaluate our test and conclude that our method is reliable and powerful for assessing common assumptions on the structure of copulas, particularly when the sample size is moderately large. We illustrate our testing approach on two datasets. © 2013 American Statistical Association.

  19. The probability of object-scene co-occurrence influences object identification processes.

    Science.gov (United States)

    Sauvé, Geneviève; Harmand, Mariane; Vanni, Léa; Brodeur, Mathieu B

    2017-07-01

    Contextual information allows the human brain to make predictions about the identity of objects that might be seen and irregularities between an object and its background slow down perception and identification processes. Bar and colleagues modeled the mechanisms underlying this beneficial effect suggesting that the brain stocks information about the statistical regularities of object and scene co-occurrence. Their model suggests that these recurring regularities could be conceptualized along a continuum in which the probability of seeing an object within a given scene can be high (probable condition), moderate (improbable condition) or null (impossible condition). In the present experiment, we propose to disentangle the electrophysiological correlates of these context effects by directly comparing object-scene pairs found along this continuum. We recorded the event-related potentials of 30 healthy participants (18-34 years old) and analyzed their brain activity in three time windows associated with context effects. We observed anterior negativities between 250 and 500 ms after object onset for the improbable and impossible conditions (improbable more negative than impossible) compared to the probable condition as well as a parieto-occipital positivity (improbable more positive than impossible). The brain may use different processing pathways to identify objects depending on whether the probability of co-occurrence with the scene is moderate (rely more on top-down effects) or null (rely more on bottom-up influences). The posterior positivity could index error monitoring aimed to ensure that no false information is integrated into mental representations of the world.

  20. Parameter identification of civil engineering structures

    Science.gov (United States)

    Juang, J. N.; Sun, C. T.

    1980-01-01

    This paper concerns the development of an identification method required in determining structural parameter variations for systems subjected to an extended exposure to the environment. The concept of structural identifiability of a large scale structural system in the absence of damping is presented. Three criteria are established indicating that a large number of system parameters (the coefficient parameters of the differential equations) can be identified by a few actuators and sensors. An eight-bay-fifteen-story frame structure is used as example. A simple model is employed for analyzing the dynamic response of the frame structure.

  1. Identification methods for structural health monitoring

    CERN Document Server

    Papadimitriou, Costas

    2016-01-01

    The papers in this volume provide an introduction to well known and established system identification methods for structural health monitoring and to more advanced, state-of-the-art tools, able to tackle the challenges associated with actual implementation. Starting with an overview on fundamental methods, introductory concepts are provided on the general framework of time and frequency domain, parametric and non-parametric methods, input-output or output only techniques. Cutting edge tools are introduced including, nonlinear system identification methods; Bayesian tools; and advanced modal identification techniques (such as the Kalman and particle filters, the fast Bayesian FFT method). Advanced computational tools for uncertainty quantification are discussed to provide a link between monitoring and structural integrity assessment. In addition, full scale applications and field deployments that illustrate the workings and effectiveness of the introduced monitoring schemes are demonstrated.

  2. Structural Time Domain Identification Toolbox User's Guide

    DEFF Research Database (Denmark)

    Andersen, P.; Kirkegaard, Poul Henning; Brincker, Rune

    This manual describes the Structural Time Domain Identification toolbox for use with MA TLAB. This version of the tool box has been developed using the PC-based MA TLAB version 4.2c, but is compatible with prior versions of MATLAB and UNIX-based versions. The routines of the toolbox are the so...

  3. Ecological traits influence the phylogenetic structure of bird species co-occurrences worldwide

    NARCIS (Netherlands)

    Barnagaud, J.-Y.; Kissling, W.D.; Sandel, B.; Eiserhardt, W.L.; Şekercioğlu, Ç.H.; Enquist, B.J.; Tsirogiannis, C.; Svenning, J.-C.

    2014-01-01

    The extent to which species’ ecological and phylogenetic relatedness shape their co-occurrence patterns at large spatial scales remains poorly understood. By quantifying phylogenetic assemblage structure within geographic ranges of >8000 bird species, we show that global co-occurrence patterns are

  4. Life time forecasting method upon occurrence of stress corrosion cracking of structure and test device therefor

    International Nuclear Information System (INIS)

    Anzai, Hideya; Kida, Toshitaka; Urayama, Yoshinao; Kikuchi, Eiji; Shimanuki, Sei; Kuniya, Jiro; Nakata, Kiyotomo; Izumitani, Masakiyo; Hattori, Shigeo.

    1993-01-01

    A load stress is applied to a metal piece made of a material identical with the constituent material of a structure and having the sensitivity enhanced to a predetermined level, and plurality of such pieces are immersed in a corrosive circumstance in this state. Then, the time from the immersion till the rupture thereof and the number of ruptured pieces of the metal pieces are detected while observing them. The relation with the probability of rupture is plotted on a paper to determine the life time for the occurrence of minimum stress corrosion creacks (SSC) of the metal pieces. Based on the relationship between the previously determined stress and the life time for the occurrence of minimum SSC, the ratio between the life time for the occurrence of minimum SSC relative to estimated stress applied to the structure and the life time for the occurrence of minimum SSC relative to the stress applied to the metal pieces is determined as a first SSC acceleration rate. The ratio between the time of occurrence for minimum SSC and the sensitivity is determined as a second SSC acceleration rate. The first and the second SSC acceleration rates are multiplied to estimate the time for the occurrence of SSC of the structure. Then, the life time for the occurrence of SSC for the equipments and structures can be recognized quantitatively, to prevent ruptures of actual equipments and extend the life time. (N.H.)

  5. Geological Structure, Seismic energy Release and Forecasting of Rockburst Occurrence

    Czech Academy of Sciences Publication Activity Database

    Rudajev, Vladimír; Číž, Radim; Lokajíček, Tomáš; Vilhelm, Jan

    2000-01-01

    Roč. 118, č. 16 (2000), s. 171-173 ISSN 1211-1910. [Czech - Polish - Slovak Symposium on Mining Geophysics /27./. Ramzová, 05.10.1999-07.10.1999] Institutional research plan: CEZ:AV0Z3046908 Keywords : seismoacustic emission * energy -frequency distribution * multichannel statistic extrapolation Subject RIV: DC - Siesmology, Volcanology, Earth Structure

  6. Familial identification: population structure and relationship distinguishability.

    Science.gov (United States)

    Rohlfs, Rori V; Fullerton, Stephanie Malia; Weir, Bruce S

    2012-02-01

    With the expansion of offender/arrestee DNA profile databases, genetic forensic identification has become commonplace in the United States criminal justice system. Implementation of familial searching has been proposed to extend forensic identification to family members of individuals with profiles in offender/arrestee DNA databases. In familial searching, a partial genetic profile match between a database entrant and a crime scene sample is used to implicate genetic relatives of the database entrant as potential sources of the crime scene sample. In addition to concerns regarding civil liberties, familial searching poses unanswered statistical questions. In this study, we define confidence intervals on estimated likelihood ratios for familial identification. Using these confidence intervals, we consider familial searching in a structured population. We show that relatives and unrelated individuals from population samples with lower gene diversity over the loci considered are less distinguishable. We also consider cases where the most appropriate population sample for individuals considered is unknown. We find that as a less appropriate population sample, and thus allele frequency distribution, is assumed, relatives and unrelated individuals become more difficult to distinguish. In addition, we show that relationship distinguishability increases with the number of markers considered, but decreases for more distant genetic familial relationships. All of these results indicate that caution is warranted in the application of familial searching in structured populations, such as in the United States.

  7. Familial identification: population structure and relationship distinguishability.

    Directory of Open Access Journals (Sweden)

    Rori V Rohlfs

    2012-02-01

    Full Text Available With the expansion of offender/arrestee DNA profile databases, genetic forensic identification has become commonplace in the United States criminal justice system. Implementation of familial searching has been proposed to extend forensic identification to family members of individuals with profiles in offender/arrestee DNA databases. In familial searching, a partial genetic profile match between a database entrant and a crime scene sample is used to implicate genetic relatives of the database entrant as potential sources of the crime scene sample. In addition to concerns regarding civil liberties, familial searching poses unanswered statistical questions. In this study, we define confidence intervals on estimated likelihood ratios for familial identification. Using these confidence intervals, we consider familial searching in a structured population. We show that relatives and unrelated individuals from population samples with lower gene diversity over the loci considered are less distinguishable. We also consider cases where the most appropriate population sample for individuals considered is unknown. We find that as a less appropriate population sample, and thus allele frequency distribution, is assumed, relatives and unrelated individuals become more difficult to distinguish. In addition, we show that relationship distinguishability increases with the number of markers considered, but decreases for more distant genetic familial relationships. All of these results indicate that caution is warranted in the application of familial searching in structured populations, such as in the United States.

  8. Meroterpenes from Marine Invertebrates: Structures, Occurrence, and Ecological Implications

    Science.gov (United States)

    Menna, Marialuisa; Imperatore, Concetta; D’Aniello, Filomena; Aiello, Anna

    2013-01-01

    Meroterpenes are widely distributed among marine organisms; they are particularly abundant within brown algae, but other important sources include microorganisms and invertebrates. In the present review the structures and bioactivities of meroterpenes from marine invertebrates, mainly sponges and tunicates, are summarized. More than 300 molecules, often complex and with unique skeletons originating from intra- and inter-molecular cyclizations, and/or rearrangements, are illustrated. The reported syntheses are mentioned. The issue of a potential microbial link to their biosynthesis is also shortly outlined. PMID:23685889

  9. Natural Cr3+-rich ettringite: occurrence, properties, and crystal structure

    Science.gov (United States)

    Seryotkin, Yurii V.; Sokol, Ella V.; Kokh, Svetlana N.; Murashko, Mikhail N.

    2017-08-01

    Cr3+-rich ettringite with Cr3+→Al substitution and Cr/(Cr + Al) ratios up to 0.40-0.50 was found in mineral assemblages of the Ma'aleh Adumim area of Mottled Zone (Judean Desert). The Cr3+-rich compositions were the latest in the thaumasite → ettringite-thaumasite solid solution → ettringite → ettringite-bentorite solid solution series. The mineral-forming solution was enriched in Cr3+ and had a pH buffered by afwillite at 11-12. Chromium was inherited from larnite rocks produced by high-temperature combustion metamorphic alteration of bioproductive calcareous sediments. The Cr/(Cr + Al) ratios are within 0.10-0.15 in most of the analysed crystals. This degree of substitution imparts pink colouration to the crystals, but does not affect their habit (a combination of monohedra and a prism). The habit changes to pyramid faces in coarse and later Cr3+-bearing crystals as Cr/(Cr + Al) ratios increase abruptly to 0.40-0.50. Single-crystal XRD analysis of one Cr-free and two Cr3+-rich samples and their structure determination and refinement indicate that the Cr-rich crystals (with Cr/(Cr + Al) to 0.3) preserve the symmetry and metrics of ettringite. The Ca-O bonding network undergoes differentiation with increase of Cr3+ concentration at octahedral M sites. The compression of Ca2 and expansion of Ca1 polyhedra sub-networks correlates with the degree of Cr3+→Al substitution.

  10. Identification of Non-Linear Structures using Recurrent Neural Networks

    DEFF Research Database (Denmark)

    Kirkegaard, Poul Henning; Nielsen, Søren R. K.; Hansen, H. I.

    Two different partially recurrent neural networks structured as Multi Layer Perceptrons (MLP) are investigated for time domain identification of a non-linear structure.......Two different partially recurrent neural networks structured as Multi Layer Perceptrons (MLP) are investigated for time domain identification of a non-linear structure....

  11. Identification of Non-Linear Structures using Recurrent Neural Networks

    DEFF Research Database (Denmark)

    Kirkegaard, Poul Henning; Nielsen, Søren R. K.; Hansen, H. I.

    1995-01-01

    Two different partially recurrent neural networks structured as Multi Layer Perceptrons (MLP) are investigated for time domain identification of a non-linear structure.......Two different partially recurrent neural networks structured as Multi Layer Perceptrons (MLP) are investigated for time domain identification of a non-linear structure....

  12. Identification and Assessment of Recent Aging-Related Degradation Occurrences in U.S. Nuclear Power Plants

    International Nuclear Information System (INIS)

    Choi, In Kil; Kim, Min Kyu; Choun, Young Sun; Hofmayer, Charles; Braverman, Joseph; Nie, Jinsou

    2008-11-01

    This report describes the research effort performed by BNL for the Year 1 scope of work. This research focused on collecting and reviewing degradation occurrences in US NPPs and identifying important aging characteristics needed for the seismic capability evaluations that will be performed in the subsequent evaluations in the years that follow. The report presents results of the statistical and trending analysis of this data and compares the results to prior aging studies. In addition, this report provides a description of current regulatory requirements, regulatory guidance documents, generic communications, industry standards and guidance, and past research related to aging degradation of SSCs. Finally, this report provides the conclusions reached from this research effort, which includes a summary of the findings from the identification and evaluation effort of degradation occurrences, an assessment of the degradation trending results, and insights into the important aging characteristics that should be considered in the tasks to be performed in the Year 2 through 5 research effort

  13. Identification of clinical and paraclinical findings predictive for headache occurrence during spontaneous subarachnoid hemorrhage.

    Science.gov (United States)

    Ljubisavljevic, Srdjan; Milosevic, Vuk; Stojanov, Aleksandar; Ljubisavljevic, Marina; Dunjic, Olivera; Zivkovic, Miroslava

    2017-07-01

    Headache is recognized as the main but unwarranted symptom of subarachnoid hemorrhage (SAH). There are no enough findings identified as predictive for headache occurrence in SAH. We evaluated the clinical and paraclinical factors predictive for headache occurrence in SAH. We retrospectively analyzed medical records of 431 consecutive non traumatic SAH patients (264 females and 167 males), ages from 19 to 91 years, presenting with headache (70.3%) and without headache (29.7%) during period of 11years. Among all tested parameters, as negative predictors for headache occurrence were recognized: patients' ages (OR 0.97 [95%CI: 0.96-0.99], p=0.025), persistence of coagulation abnormality (OR 0.23 [95%CI: 0.08-0.67], p=0.006), atrial fibrilation (OR 0.23 [95%CI: 0.09-0.59], p=0.002), chronic renal failure (OR 0.26 [95%CI: 0.09-0.76], p=0.014) and more diseases (OR 0.11 [95%CI: 0.04-0.32], p<0.0001), as higher clinical score (OR 0.94 [95%CI: 0.90-0.99], p=0.018) including positive neurological findings (OR 0.34 [95%CI: 0.21-0.55], p<0.001) and loss of consciousness (OR 0.22 [95%CI: 0.12-0.39], p<0.001) at the SAH onset, while the complaint of neck stiffness was identified as its positive predictor (OR 1.93 [95%CI: 1.19-3.10], p=0.007). Although diagnosis based solely on clinical presentation is not reliable and speculative, our findings could provide physicians with evidence to consider SAH not only in conditions of its headache occurrence but also in those with headache absence. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Are there co-occurrence patterns that structure snake communities in Central Brazil?

    Science.gov (United States)

    França, F G R; Araújo, A F B

    2007-02-01

    The main factors that structure Neotropical animal communities have been the subject of discussion in ecology communities. We used a set of null models to investigate the existence of structure in snake communities from the Cerrado in Central Brazil in relation to the co-occurrence of species and guilds concerning specific resources. We used fragments (conservation units) inside the Distrito Federal and neighbor municipalities. In spite of recent human colonization in the region from the end of the 1950s, intense habitat modification and fragmentation has taken place. Sixty three snake species are present in the Distrito Federal. Co-occurrence analysis of species and guilds associated to snake diets and habitats suggested a lack of organization. The homogeneity of habitats in Central Brazil and the minor importance of ecological effects can lead to random arrangement.

  15. Multi-stage identification scheme for detecting damage in structures under ambient excitations

    International Nuclear Information System (INIS)

    Bao, Chunxiao; Li, Zhong-Xian; Hao, Hong

    2013-01-01

    Structural damage identification methods are critical to the successful application of structural health monitoring (SHM) systems to civil engineering structures. The dynamic response of civil engineering structures is usually characterized by high nonlinearity and non-stationarity. Accordingly, an improved Hilbert–Huang transform (HHT) method which is adaptive, output-only and applicable to system identification of in-service structures under ambient excitations is developed in this study. Based on this method, a multi-stage damage detection scheme including the detection of damage occurrence, damage existence, damage location and the estimation of damage severity is developed. In this scheme, the improved HHT method is used to analyse the structural acceleration response, the obtained instantaneous frequency detects the instant of damage occurrence, the instantaneous phase is sensitive to minor damage and provides reliable damage indication, and the damage indicator developed based on statistical analysis of the Hilbert marginal spectrum detects damage locations. Finally, the response sampled at the detected damage location is continuously analysed to estimate the damage severity. Numerical and experimental studies of frame structures under ambient excitations are performed. The results demonstrate that this scheme accomplishes the above damage detection functions within one flow. It is robust, time efficient, simply implemented and applicable to the real-time SHM of in-service structures. (paper)

  16. Identification of Light Damping in Structures

    DEFF Research Database (Denmark)

    Jensen, Jacob Laigaard; Brincker, Rune; Rytter, Anders

    is identification by ARMA models assuming a white noise input. Method 2 is identification by simulation of a free decay response. Experimental data on the free decay response has been obtained directly by measurement as well as by the random decrement technique. Two experimental cases has been considered. The first...

  17. Identification of Light Damping in Structures

    DEFF Research Database (Denmark)

    Jensen, J. L.; Brincker, Rune; Rytter, A.

    1990-01-01

    is identification by ARMA models assuming a white noise input.Method 2 is identification by simulation of a free decay response. Experimental data on the free decay response has been obtained directly by measurement as well as by the random decrement technique. Two experimental cases has been considered. the first...

  18. Detection of stable community structures within gut microbiota co-occurrence networks from different human populations.

    Science.gov (United States)

    Jackson, Matthew A; Bonder, Marc Jan; Kuncheva, Zhana; Zierer, Jonas; Fu, Jingyuan; Kurilshikov, Alexander; Wijmenga, Cisca; Zhernakova, Alexandra; Bell, Jordana T; Spector, Tim D; Steves, Claire J

    2018-01-01

    Microbes in the gut microbiome form sub-communities based on shared niche specialisations and specific interactions between individual taxa. The inter-microbial relationships that define these communities can be inferred from the co-occurrence of taxa across multiple samples. Here, we present an approach to identify comparable communities within different gut microbiota co-occurrence networks, and demonstrate its use by comparing the gut microbiota community structures of three geographically diverse populations. We combine gut microbiota profiles from 2,764 British, 1,023 Dutch, and 639 Israeli individuals, derive co-occurrence networks between their operational taxonomic units, and detect comparable communities within them. Comparing populations we find that community structure is significantly more similar between datasets than expected by chance. Mapping communities across the datasets, we also show that communities can have similar associations to host phenotypes in different populations. This study shows that the community structure within the gut microbiota is stable across populations, and describes a novel approach that facilitates comparative community-centric microbiome analyses.

  19. Identification of suitable areas for the occurrence of Rift Valley fever outbreaks in Spain using a multiple criteria decision framework.

    Science.gov (United States)

    Sánchez-Vizcaíno, Fernando; Martínez-López, Beatriz; Sánchez-Vizcaíno, José Manuel

    2013-07-26

    Rift Valley fever (RVF) is a mosquito-borne viral disease that may produce a considerable impact on the economy in affected countries. In the last decades, the geographic distribution of RVF virus has increased including most of the countries in Africa, Arabia Saudi and Yemen. This situation has raised the concerns regarding its potential introduction in the European Union (EU) countries where the high number of susceptible species and competent vectors may contribute to the spread of the disease and challenge its rapid control. Thus, the identification of the areas and time periods with highest suitability for RVF outbreak occurrence would be useful for improving the early detection and rapid response of the disease into free countries. The objective of this study was to identify suitable areas for the occurrence of RVF outbreaks in Spain using a multiple criteria decision making model based on weighted linear combination of factors in geographical information systems (GIS). To the best of the author's knowledge this is the first comprehensive GIS-based framework that provides risk maps for RVF suitability in an EU country. Spanish zones with the highest suitability for RVF were concentrated in the regions of Extremadura, south-western Castile and Leon, eastern Galicia, Asturias, Cantabria, Basque Country, northern-central and southern region of Andalusia and in the Balearic Islands. October and May were the most suitable months for RVF outbreak occurrence. Methods and results presented here may be useful to target risk-based surveillance strategies and to more cost-effectively control potential RVFV incursions into Spain. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. Occurrence and identification of yeast species in fermented liquid feed for piglets

    DEFF Research Database (Denmark)

    Gori, Klaus; Bjørklund, Marina Kryger; Canibe, Nuria

    2011-01-01

    The major objective of the present study was to investigate the occurrence and identity of yeast species in fermented liquid feed (FLF) used for feeding piglets. In total, 40 different Danish farms were included in the analysis. The preparation and composition of FLF was found to be very...... heterogeneous with high variations in both yeast counts and yeast species composition. The yeast population varied between 6.0 × 10(3) and 4.2 × 10(7) cfug(-1) with an average yeast count of 8.7 × 10(6) ± 1.1 × 10(7) cfug(-1). A total of 766 yeasts were isolated and identified by conventional and/or molecular...... typing techniques. The predominant yeast species in the FLF samples were found to be Candida milleri (58.4%), Kazachstania exigua (17.5%), Candida pararugosa (6.40%) and Kazachstania bulderi (5.09%). No clear separation between isolates of C. milleri and Candida humilis could be obtained based...

  1. Occurrence of Clostridium perfringens contamination in poultry feed ingredients: Isolation, identification and its antibiotic sensitivity pattern

    Directory of Open Access Journals (Sweden)

    Shanmugasundaram Udhayavel

    2017-09-01

    Full Text Available This work has been undertaken to study the occurrence of Clostridium perfringens contamination in the poultry feed ingredients and find out its in-vitro antibiotic sensitivity pattern to various antimicrobial drugs. Two hundred and ninety-eight poultry feed ingredient samples received at Poultry Disease Diagnosis and Surveillance Laboratory, Namakkal, Tamil Nadu in South India were screened for the presence of C. perfringens. The organisms were isolated in Perfringens agar under anaerobic condition and subjected to standard biochemical tests for confirmation. In vitro antibiogram assay has been carried out to determine the sensitivity pattern of the isolates to various antimicrobial drugs. One hundred and one isolates of C. perfringens were obtained from a total of 298 poultry feed ingredient samples. Overall positivity of 33.89% could be made from the poultry feed ingredients. Highest level of C. perfringens contamination was detected in fish meal followed by bone meal, meat and bone meal and dry fish. Antibiogram assay indicated that the organisms are highly sensitive to gentamicin (100%, chlortetracycline (96.67%, gatifloxacin (93.33%, ciprofloxacin (86.67%, ofloxacin (86.67% and lincomycin (86.67%. All the isolates were resistant to penicillin-G. Feed ingredients rich in animal proteins are the major source of C. perfringens contamination.

  2. A review of phenolic compounds in oil-bearing plants: Distribution, identification and occurrence of phenolic compounds.

    Science.gov (United States)

    Alu'datt, Muhammad H; Rababah, Taha; Alhamad, Mohammad N; Al-Mahasneh, Majdi A; Almajwal, Ali; Gammoh, Sana; Ereifej, Khalil; Johargy, Ayman; Alli, Inteaz

    2017-03-01

    Over the last two decades, separation, identification and measurement of the total and individual content of phenolic compounds has been widely investigated. Recently, the presence of a wide range of phenolic compounds in oil-bearing plants has been shown to contribute to their therapeutic properties, including anti-cancer, anti-viral, anti-oxidant, hypoglycemic, hypo-lipidemic, and anti-inflammatory activities. Phenolics in oil-bearing plants are now recognized as important minor food components due to several organoleptic and health properties, and they are used as food or sources of food ingredients. Variations in the content of phenolics in oil-bearing plants have largely been attributed to several factors, including the cultivation, time of harvest and soil types. A number of authors have suggested that the presence phenolics in extracted proteins, carbohydrates and oils may contribute to objectionable off flavors The objective of this study was to review the distribution, identification and occurrence of free and bound phenolic compounds in oil-bearing plants. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. A modular structure to accident identification using neural networks

    International Nuclear Information System (INIS)

    Duque Estrada, Cassius Rodrigo

    2005-01-01

    This work uses the accident identification method based on Artificial Neural Networks (ANN) as basic blocks of a modular structure, allowing the inclusion of new accidents to be identified without modifying the ANN already trained. This structure comprises several modules for accident identification and one module for analysis. Each identification module follows the structure of the basic block. The identification modules are responsible for the recognition of an accident belonging to the specific set of events for which it were trained. The analysis module processes the output from the identification module to determine the system response. In order to test this structure it was proposed a transient identification problem comprising fifty accidents distributed in five identification modules. The results have demonstrated that the accident identification method used as basic block of a modular structure allows the inclusion of new sets of accidents, or variations of a same accident, without modifying the ANN already trained. For this, it is enough to include into the system an specific module for this new set of accidents. (author)

  4. Changes in Cold Surge Occurrence over East Asia in the Future: Role of Thermal Structure

    Directory of Open Access Journals (Sweden)

    Jin-Woo Heo

    2018-06-01

    Full Text Available The occurrence of wintertime cold surges (CSs over East Asia is largely controlled by the surface air temperature (SAT distribution at high latitudes and thermal advection in the lower troposphere. The thermodynamic background state over northeastern Asia is associated with the strength of the East Asian winter monsoon and the variation of Arctic Oscillation. This study assesses the importance of the SAT structure with thermal advection in determining the frequency of CS occurrences over East Asia through the analysis of nine atmosphere–ocean coupled global climate models participating in the Coupled Model Intercomparison Project Phase 5. The historical simulations can reproduce the observed typical characteristics of CS development. On the basis of this model performance, ensemble-averaged future simulations under the representative concentration pathway 8.5 project a reduction in CS frequency by 1.1 yr−1 in the late 21st century (2065–2095 compared to the present-day period (1975–2005. The major reason for less frequent CSs in the future is the weakened cold advection, caused by notable SAT warming over the northern part of East Asia. These results suggest that changes in the meridional SAT structure and the associated changes in thermal advection would play a more substantial role than local warming in determining future changes in the frequency of CS occurrences over East Asia.

  5. Search-based model identification of smart-structure damage

    Science.gov (United States)

    Glass, B. J.; Macalou, A.

    1991-01-01

    This paper describes the use of a combined model and parameter identification approach, based on modal analysis and artificial intelligence (AI) techniques, for identifying damage or flaws in a rotating truss structure incorporating embedded piezoceramic sensors. This smart structure example is representative of a class of structures commonly found in aerospace systems and next generation space structures. Artificial intelligence techniques of classification, heuristic search, and an object-oriented knowledge base are used in an AI-based model identification approach. A finite model space is classified into a search tree, over which a variant of best-first search is used to identify the model whose stored response most closely matches that of the input. Newly-encountered models can be incorporated into the model space. This adaptativeness demonstrates the potential for learning control. Following this output-error model identification, numerical parameter identification is used to further refine the identified model. Given the rotating truss example in this paper, noisy data corresponding to various damage configurations are input to both this approach and a conventional parameter identification method. The combination of the AI-based model identification with parameter identification is shown to lead to smaller parameter corrections than required by the use of parameter identification alone.

  6. Structural Time Domain Identification (STDI) Toolbox for Use with MATLAB

    DEFF Research Database (Denmark)

    Kirkegaard, Poul Henning; Andersen, P.; Brincker, Rune

    1997-01-01

    The Structural Time Domain Identification (STDI) toolbox for use with MATLABTM is developed at Aalborg University, Denmark, based on the system identification research performed during recent years. By now, a reliable set of functions offers a wide spectrum of services for all the important steps...

  7. Structural Time Domain Identification (STDI) Toolbox for Use with MATLAB

    DEFF Research Database (Denmark)

    Kirkegaard, Poul Henning; Andersen, P.; Brincker, Rune

    The Structural Time Domain Identification (STDI) toolbox for use with MATLABTM is developed at Aalborg University, Denmark, based on the system identification research performed during recent years. By now, a reliable set of functions offers a wide spectrum of services for all the important steps...

  8. Monte Carlo filters for identification of nonlinear structural dynamical ...

    Indian Academy of Sciences (India)

    The theory of Kalman filtering provides one of ...... expansion (appendix B contains a reasonably self-contained account of how such expansions ...... Shinozuka M, Ghanem R 1995 Structural system identification II: experimental verification.

  9. Structural Acoustic UXO Detection and Identification in Marine Environments

    Science.gov (United States)

    2016-05-01

    a thick steel wall, is cylindrical, and has an aspect ratio of about 5:1. Further, the interior water can support acoustic waves as does the epoxy...FINAL REPORT Structural Acoustic UXO Detection and Identification in Marine Environments SERDP Project MR-2103 MAY 2016 B. H...NUMBER Structural Acoustic UXO Detection and Identification in Marine Environments- Final report for Follow-on Work- MR-2103 Sb. GRANT NUMBER Sc

  10. Occurrence and structure of extrafloral nectariesin Pterodon pubescens Benth. and Pterodon polygalaeflorus Benth.

    Directory of Open Access Journals (Sweden)

    Paiva Élder Antônio Sousa e

    2001-01-01

    Full Text Available Extrafloral nectaries (EFNs are structurally variable and widely spread among the angiosperms. The occurrence of EFNs in leaves of Pterodon polygalaeflorus Benth. and Pterodon pubescens Benth. (Fabaceae: Papilionoideae were detected in adult specimens, at the time of production of new buds and flowers. The goals of the present study are to register the occurrence of the EFNs in P. pubescens and P. polygalaeflorus, and provide comparative data on the anatomical structures. The EFNs occur in the rachis and are located under the insertion of each petiolule. Each nectary consists of a small elevation whose apical portion is deeply invaginated, resulting in a depression (secretory pole, a common characteristic of both species. Unicellular, nonglandular trichomes occur along the rachis, being less numerous in P. polygalaeflorus while in P. pubescens they cover the EFNs. The secretory tissue consists of parenchyma cells with dense cytoplasm compactly arranged. The nectar reaches the surface of the EFNs by rupturing the thin cuticle which covers the secretory pole, since both species lack stomata or any other interruption at the epidermis. The basic difference between the two species, in relation to the EFNs, is the density of the pubescence, which is always greater in P. pubescens. Structural and dimensional modifications may be observed, even between basal and apical nectaries in the same rachis, so it does not constitute a taxonomical tool.

  11. Probabilistic structural damage identification based on vibration data

    International Nuclear Information System (INIS)

    Hao, H.; Xia, Y.

    2001-01-01

    Vibration-based methods are being rapidly developed and applied to detect structural damage in civil, mechanical and aerospace engineering communities in the last two decades. But uncertainties existing in the structural model and measured vibration data might lead to unreliable results. This paper will present some recent research results to tackle the above mentioned uncertainty problems. By assuming each of the FE model parameters and measured vibration data as a normally distributed random variable, a probabilistic damage detection procedure is developed based on perturbation method and validated by Monte Carlo simulation technique. With this technique, the damage probability of each structural element can be determined. The method developed has been verified by applying it to identify the damages of laboratory tested structures. It was proven that, as compared to the deterministic damage identification method, the present method can not only reduce the possibility of false identification, but also give the identification results in terms of probability. which is deemed more realistic and practical in detecting possible damages in a structure. It has also been found that the modal data included in damage identification analysis have a great influence on the identification results. With a sensitivity study, an optimal measurement set for damage detection is determined. This set includes the optimal measurement locations and the most appropriate modes that should be used in the damage identification analysis. Numerical results indicated that if the optimal set determined in a pre-analysis is used in the damage detection better results will be achieved. (author)

  12. From GenBank to GBIF: Phylogeny-Based Predictive Niche Modeling Tests Accuracy of Taxonomic Identifications in Large Occurrence Data Repositories.

    Science.gov (United States)

    Smith, B Eugene; Johnston, Mark K; Lücking, Robert

    2016-01-01

    Accuracy of taxonomic identifications is crucial to data quality in online repositories of species occurrence data, such as the Global Biodiversity Information Facility (GBIF), which have accumulated several hundred million records over the past 15 years. These data serve as basis for large scale analyses of macroecological and biogeographic patterns and to document environmental changes over time. However, taxonomic identifications are often unreliable, especially for non-vascular plants and fungi including lichens, which may lack critical revisions of voucher specimens. Due to the scale of the problem, restudy of millions of collections is unrealistic and other strategies are needed. Here we propose to use verified, georeferenced occurrence data of a given species to apply predictive niche modeling that can then be used to evaluate unverified occurrences of that species. Selecting the charismatic lichen fungus, Usnea longissima, as a case study, we used georeferenced occurrence records based on sequenced specimens to model its predicted niche. Our results suggest that the target species is largely restricted to a narrow range of boreal and temperate forest in the Northern Hemisphere and that occurrence records in GBIF from tropical regions and the Southern Hemisphere do not represent this taxon, a prediction tested by comparison with taxonomic revisions of Usnea for these regions. As a novel approach, we employed Principal Component Analysis on the environmental grid data used for predictive modeling to visualize potential ecogeographical barriers for the target species; we found that tropical regions conform a strong barrier, explaining why potential niches in the Southern Hemisphere were not colonized by Usnea longissima and instead by morphologically similar species. This approach is an example of how data from two of the most important biodiversity repositories, GenBank and GBIF, can be effectively combined to remotely address the problem of inaccuracy of

  13. Fire modifies the phylogenetic structure of soil bacterial co-occurrence networks.

    Science.gov (United States)

    Pérez-Valera, Eduardo; Goberna, Marta; Faust, Karoline; Raes, Jeroen; García, Carlos; Verdú, Miguel

    2017-01-01

    Fire alters ecosystems by changing the composition and community structure of soil microbes. The phylogenetic structure of a community provides clues about its main assembling mechanisms. While environmental filtering tends to reduce the community phylogenetic diversity by selecting for functionally (and hence phylogenetically) similar species, processes like competitive exclusion by limiting similarity tend to increase it by preventing the coexistence of functionally (and phylogenetically) similar species. We used co-occurrence networks to detect co-presence (bacteria that co-occur) or exclusion (bacteria that do not co-occur) links indicative of the ecological interactions structuring the community. We propose that inspecting the phylogenetic structure of co-presence or exclusion links allows to detect the main processes simultaneously assembling the community. We monitored a soil bacterial community after an experimental fire and found that fire altered its composition, richness and phylogenetic diversity. Both co-presence and exclusion links were more phylogenetically related than expected by chance. We interpret such a phylogenetic clustering in co-presence links as a result of environmental filtering, while that in exclusion links reflects competitive exclusion by limiting similarity. This suggests that environmental filtering and limiting similarity operate simultaneously to assemble soil bacterial communities, widening the traditional view that only environmental filtering structures bacterial communities. © 2016 Society for Applied Microbiology and John Wiley & Sons Ltd.

  14. Identification of Damping from Structural Vibrations

    DEFF Research Database (Denmark)

    Bajric, Anela

    Reliable predictions of the dynamic loads and the lifetime of structures are influenced by the limited accuracy concerning the level of structural damping. The mechanisms of damping cannot be derived analytically from first principles, and in the design of structures the damping is therefore based...... on experience or estimated from measurements. This thesis consists of an extended summary and three papers which focus on enhanced methods for identification of damping from random struc-tural vibrations. The developed methods are validated by stochastic simulations, experimental data and full-scale measurements...... which are representative of the vibrations in small and large-scale structures. The first part of the thesis presents an automated procedure which is suitable for estimation of the natural frequencies and the modal damping ratios from random response of structures. The method can be incorporated within...

  15. Built structure identification in wildland fire decision support

    Science.gov (United States)

    David E. Calkin; Jon D. Rieck; Kevin D. Hyde; Jeffrey D. Kaiden

    2011-01-01

    Recent ex-urban development within the wildland interface has significantly increased the complexity and associated cost of federal wildland fire management in the United States. Rapid identification of built structures relative to probable fire spread can help to reduce that complexity and improve the performance of incident management teams. Approximate structure...

  16. Improved Stochastic Subspace System Identification for Structural Health Monitoring

    Science.gov (United States)

    Chang, Chia-Ming; Loh, Chin-Hsiung

    2015-07-01

    Structural health monitoring acquires structural information through numerous sensor measurements. Vibrational measurement data render the dynamic characteristics of structures to be extracted, in particular of the modal properties such as natural frequencies, damping, and mode shapes. The stochastic subspace system identification has been recognized as a power tool which can present a structure in the modal coordinates. To obtain qualitative identified data, this tool needs to spend computational expense on a large set of measurements. In study, a stochastic system identification framework is proposed to improve the efficiency and quality of the conventional stochastic subspace system identification. This framework includes 1) measured signal processing, 2) efficient space projection, 3) system order selection, and 4) modal property derivation. The measured signal processing employs the singular spectrum analysis algorithm to lower the noise components as well as to present a data set in a reduced dimension. The subspace is subsequently derived from the data set presented in a delayed coordinate. With the proposed order selection criteria, the number of structural modes is determined, resulting in the modal properties. This system identification framework is applied to a real-world bridge for exploring the feasibility in real-time applications. The results show that this improved system identification method significantly decreases computational time, while qualitative modal parameters are still attained.

  17. Identification of protein markers for the occurrence of defrosted material in milk through a MALDI-TOF-MS profiling approach.

    Science.gov (United States)

    Arena, Simona; Salzano, Anna Maria; Scaloni, Andrea

    2016-09-16

    Mozzarella di Bufala Campana is a soft, stretched curd Italian cheese made from fresh buffalo milk that obtained the Protected Designation of Origin (PDO) registration in EU legislation. Seasonality of buffalo milk production, rapid cheese decay and transport of its preserving liquid have relevant practical/economic consequences for mozzarella production; consequently, a progressive diffusion of cheese products realized with frozen curd or frozen milk has recently been observed. In order to meet the demand of the dairy producers and consumers for a reduction of starting material adulterations and for the certification of the raw milk used for cheese manufacturing, we have developed a rapid/robust MALDI-TOF-MS polypeptide profiling procedure that assays material quality through the identification of specific markers of its freshness. Massive analysis of fresh and frozen buffalo milks (stored for different times) was realized to this purpose; a tough statistical evaluation of the resulting data ultimately permitted the typing of milk samples. We identified 28 polypeptide markers of the milk freezing storage, among which 13 and 15 showed down- and over-representation, respectively. Quantitative data were confirmed by an independent analytical approach on selected markers. GLYCAM1-derived phosphopeptides (1-53), β-casein-derived phosphopeptides (1-68), β-casein-derived γ2-, γ3- and γ4-fragments, α-lactalbumin and β-lactoglobulin were components showing the highest significance. The occurrence of the first compounds in buffalo milk is here described for the first time; their formation in the frozen material was ascribed to the activity of plasmin or of unknown bacterial proteases/peptidases stable at low temperatures. In conclusion, data reported here suggest the application of this MALDI-TOF-MS polypeptide profiling platform to other high-quality dairy productions, in which milk freshness has important consequences on final product organoleptic properties. In

  18. Using co-occurrence network structure to extract synonymous gene and protein names from MEDLINE abstracts

    Directory of Open Access Journals (Sweden)

    Spackman K

    2005-04-01

    Full Text Available Abstract Background Text-mining can assist biomedical researchers in reducing information overload by extracting useful knowledge from large collections of text. We developed a novel text-mining method based on analyzing the network structure created by symbol co-occurrences as a way to extend the capabilities of knowledge extraction. The method was applied to the task of automatic gene and protein name synonym extraction. Results Performance was measured on a test set consisting of about 50,000 abstracts from one year of MEDLINE. Synonyms retrieved from curated genomics databases were used as a gold standard. The system obtained a maximum F-score of 22.21% (23.18% precision and 21.36% recall, with high efficiency in the use of seed pairs. Conclusion The method performs comparably with other studied methods, does not rely on sophisticated named-entity recognition, and requires little initial seed knowledge.

  19. Parameter identification for structural dynamics based on interval analysis algorithm

    Science.gov (United States)

    Yang, Chen; Lu, Zixing; Yang, Zhenyu; Liang, Ke

    2018-04-01

    A parameter identification method using interval analysis algorithm for structural dynamics is presented in this paper. The proposed uncertain identification method is investigated by using central difference method and ARMA system. With the help of the fixed memory least square method and matrix inverse lemma, a set-membership identification technology is applied to obtain the best estimation of the identified parameters in a tight and accurate region. To overcome the lack of insufficient statistical description of the uncertain parameters, this paper treats uncertainties as non-probabilistic intervals. As long as we know the bounds of uncertainties, this algorithm can obtain not only the center estimations of parameters, but also the bounds of errors. To improve the efficiency of the proposed method, a time-saving algorithm is presented by recursive formula. At last, to verify the accuracy of the proposed method, two numerical examples are applied and evaluated by three identification criteria respectively.

  20. Seismic characteristics and identification of negative flower structures, positive flower structures, and positive structural inversion

    Energy Technology Data Exchange (ETDEWEB)

    Harding, T.P.

    1985-04-01

    Negative and positive flower structures and positive inverted structures imply specific modes of formation, and their distinctive characteristics make them important criteria for the identification of certain structural styles. A negative flower structure from the Andaman Sea consists of a shallow synform bounded by upward-spreading strands of a wrench fault that have mostly normal separations. Paralleling monoclines and oblique, en echelon normal faults flank the divergent wrench fault. A positive flower structure from the Ardmore basin, Oklahoma, consists of a shallow antiform displaced by the upward diverging strands of a wrench fault that have mostly reverse separations. En echelon folds are present on either side of this convergent wrench fault. Positive structural inversion at the Rambutan oil field, South Sumatra basin, has formed a shallow anticlinorium and has partly uplifted the underlying graben. Deeper fault segments bounding the graben have retained their normal fault profiles, but at shallow levels some of these faults have reverse separations.

  1. Experimental identification of smart material coupling effects in composite structures

    International Nuclear Information System (INIS)

    Chesne, S; Jean-Mistral, C; Gaudiller, L

    2013-01-01

    Smart composite structures have an enormous potential for industrial applications, in terms of mass reduction, high material resistance and flexibility. The correct characterization of these complex structures is essential for active vibration control or structural health monitoring applications. The identification process generally calls for the determination of a generalized electromechanical coupling coefficient. As this process can in practice be difficult to implement, an original approach, presented in this paper, has been developed for the identification of the coupling effects of a smart material used in a composite curved beam. The accuracy of the proposed identification technique is tested by applying active modal control to the beam, using a reduced model based on this identification. The studied structure was as close to reality as possible, and made use of integrated transducers, low-cost sensors, clamped boundary conditions and substantial, complex excitation sources. PVDF (polyvinylidene fluoride) and MFC (macrofiber composite) transducers were integrated into the composite structure, to ensure their protection from environmental damage. The experimental identification described here was based on a curve fitting approach combined with the reduced model. It allowed a reliable, powerful modal control system to be built, controlling two modes of the structure. A linear quadratic Gaussian algorithm was used to determine the modal controller–observer gains. The selected modes were found to have an attenuation as strong as −13 dB in experiments, revealing the effectiveness of this method. In this study a generalized approach is proposed, which can be extended to most complex or composite industrial structures when they are subjected to vibration. (paper)

  2. Evaluation of pathogenic fungi occurrence in traumatogenic structures of freshwater fish

    Directory of Open Access Journals (Sweden)

    Fabio Caetano Oliveira Leme

    2011-04-01

    Full Text Available INTRODUCTION: Fungal infections in human skin, such as sporotrichosis, can occur after fish induced trauma. This work aimed to identify fungi in freshwater fish that are pathogenic to humans. METHODS: Extraction of dental arches from Serrassalmus maculatus (piranha and Hoplias malabaricus (wolf fish, stings from Pimelodus maculatus (mandis catfish, dorsal fin rays from Plagioscion spp. (corvina and Tilapia spp., for culture in Mycosel agar. Some cultures were submitted to DNA extraction for molecular identification by sequencing ITS-5.8S rDNA. RESULTS: Cultures identified most yeast as Candida spp., while sequencing also permitted the identification of Phoma spp. and Yarrowia lipolytica. CONCLUSIONS: While the search for S. schenckii was negative, the presence of fungus of the genera Phoma and Candida revealed the pathogenic potential of this infection route. The genus Phoma is involved in certain forms of phaeohyphomycosis, a subcutaneous mycosis caused by dematiaceous fungi, with reports of infections in human organs and systems. Traumatizing structures of some freshwater fish present pathogenic fungi and this may be an important infection route that must be considered in some regions of Brazil, since there are a large number of a fisherman in constant contact with traumatogenic fish.

  3. State Space identification of Civil Engineering Structures from Output Measurements

    DEFF Research Database (Denmark)

    Kirkegaard, Poul Henning; Andersen, P.

    for identification of civil engineering structures. The SST is compared with the stochastic realization estimator Matrix Block Hankel (MBH) and a prediction error method (PEM). The results show that the investigated techniques give good results in terms of estimated modal parameters and mode shapes. Especially...

  4. State Space identification of Civil Engineering Structures from Output Measurements

    DEFF Research Database (Denmark)

    Kirkegaard, Poul Henning; Andersen, P.

    1997-01-01

    for identification of civil engineering structures. The SST is compared with the stochastic realization estimator Matrix Block Hankel (MBH) and a prediction error method (PEM). The results show that the investigated techniques give good results in terms of estimated modal parameters and mode shapes. Especially...

  5. Direct structural parameter identification by modal test results

    Science.gov (United States)

    Chen, J.-C.; Kuo, C.-P.; Garba, J. A.

    1983-01-01

    A direct identification procedure is proposed to obtain the mass and stiffness matrices based on the test measured eigenvalues and eigenvectors. The method is based on the theory of matrix perturbation in which the correct mass and stiffness matrices are expanded in terms of analytical values plus a modification matrix. The simplicity of the procedure enables real time operation during the structural testing.

  6. Phylogenetic fields through time: temporal dynamics of geographical co-occurrence and phylogenetic structure within species ranges.

    Science.gov (United States)

    Villalobos, Fabricio; Carotenuto, Francesco; Raia, Pasquale; Diniz-Filho, José Alexandre F

    2016-04-05

    Species co-occur with different sets of other species across their geographical distribution, which can be either closely or distantly related. Such co-occurrence patterns and their phylogenetic structure within individual species ranges represent what we call the species phylogenetic fields (PFs). These PFs allow investigation of the role of historical processes--speciation, extinction and dispersal--in shaping species co-occurrence patterns, in both extinct and extant species. Here, we investigate PFs of large mammalian species during the last 3 Myr, and how these correlate with trends in diversification rates. Using the fossil record, we evaluate species' distributional and co-occurrence patterns along with their phylogenetic structure. We apply a novel Bayesian framework on fossil occurrences to estimate diversification rates through time. Our findings highlight the effect of evolutionary processes and past climatic changes on species' distributions and co-occurrences. From the Late Pliocene to the Recent, mammal species seem to have responded in an individualistic manner to climate changes and diversification dynamics, co-occurring with different sets of species from different lineages across their geographical ranges. These findings stress the difficulty of forecasting potential effects of future climate changes on biodiversity. © 2016 The Author(s).

  7. Occurrence and identification of the etiologic agents of plant diseases in cactus (Opuntia ficus-indica Mill. in the semi-arid region of Paraiba

    Directory of Open Access Journals (Sweden)

    Anne Evelyne Franco de Souza

    2010-01-01

    Full Text Available Cactus forage (Opuntia ficus-indica Mill., intensely cultivated in dry regions of northeast Brazil, although well adapted to the harsh semi-arid climate is affected by major problems such as pests and diseases, responsible for significant losses in production. This study aimed to investigate the occurrence and diversity of the etiologic agents of diseases of cactus cultivated in 38 municipalities in the semi-arid region of Paraiba. The analyses were conducted and processed at the Laboratory of Phytopathology of the Centro de Ciências Agrárias da Universidade Federal da Paraíba, in Areia - PB. Starting from sick cladodes isolations, multiplications and identifications of the found microorganisms were made. The identification of the microorganisms was achieved through observations of the macro and micromorphological characteristics of the cultures and tests of Gram and pathogenicity. Great incidence and diversity of microorganisms was verified in the cacti researched, but the highest occurrence was mainly that of fungus. The fungi of widest occurrence were: Scytallidium lignicola, Alternate tenuis, Macrophomina phaseolina, Cladosporium cladosporides, Lasiodiplodia theobromae, Fusarium oxysporum f. sp. opuntiarum, Curvularia lunata, Aspergillus niger, Nigrospora sphaerica, Colletotrichum gloeosporioides, Exserohilum turcicum, Pestalotia pitospora, Rhizopus stolonifer, Rhizoctonia solani and Sphaceloma protearum. A bacterium was also detected that was suspected to belong to the Erwinia sp. strain. Satisfaction of the Postulates of Koch proved the infectious nature of the detected microorganisms. High occurrence of the fungus S. lignicola, an agent of scale rot disease in 100% of the places researched, was observed. This fact is of great concern, since the progression of the disease can cause significant losses in production.

  8. TLM modeling and system identification of optimized antenna structures

    Directory of Open Access Journals (Sweden)

    N. Fichtner

    2008-05-01

    Full Text Available The transmission line matrix (TLM method in conjunction with the genetic algorithm (GA is presented for the bandwidth optimization of a low profile patch antenna. The optimization routine is supplemented by a system identification (SI procedure. By the SI the model parameters of the structure are estimated which is used for a reduction of the total TLM simulation time. The SI utilizes a new stability criterion of the physical poles for the parameter extraction.

  9. Challenges in parameter identification of large structural dynamic systems

    International Nuclear Information System (INIS)

    Koh, C.G.

    2001-01-01

    In theory, it is possible to determine the parameters of a structural or mechanical system by subjecting it to some dynamic excitation and measuring the response. Considerable research has been carried out in this subject area known as the system identification over the past two decades. Nevertheless, the challenges associated with numerical convergence are still formidable when the system is large in terms of the number of degrees of freedom and number of unknowns. While many methods work for small systems, the convergence becomes difficult, if not impossible, for large systems. In this keynote lecture, both classical and non-classical system identification methods for dynamic testing and vibration-based inspection are discussed. For classical methods, the extended Kalman filter (EKF) approach is used. On this basis, a substructural identification method has been developed as a strategy to deal with large structural systems. This is achieved by reducing the problem size, thereby significantly improving the numerical convergence and efficiency. Two versions of this method are presented each with its own merits. A numerical example of frame structure with 20 unknown parameters is illustrated. For non-classical methods, the Genetic Algorithm (GA) is shown to be applicable with relative ease due to its 'forward analysis' nature. The computational time is, however, still enormous for large structural systems due to the combinatorial explosion problem. A model GA method has been developed to address this problem and tested with considerable success on a relatively large system of 50 degrees of freedom, accounting for input and output noise effects. An advantages of this GA-based identification method is that the objective function can be defined in response measured. Numerical studies show that the method is relatively robust, as it does in response measured. Numerical studies show that the method is relatively robust, as it dos not require good initial guess and the

  10. Identification of lightning vulnerability points on complex grounded structures

    OpenAIRE

    Becerra Garcia, Marley; Cooray, Vernon; Hartono, Z.A

    2007-01-01

    The identification of the most vulnerable points on a given structure to be struck by lightning is an important issue on the design of areliable lightning protection system. Traditionally, these lightning strike points are identified using the rolling sphere method, through anempirical correlation with the prospective peak return stroke current. However, field observations in Kuala Lumpur and Singapore haveshown that the points where lightning flashes strike buildings also depend on the heigh...

  11. Identification of multiple modes of axisymmetric or circularly repetitive structures

    International Nuclear Information System (INIS)

    Kopff, P.

    1983-01-01

    The axisymmetric structures, or those composed with circularly repetitive elements, often display multiple modes, which are not easy to separate by modal identification of experimental responses. To be able to solve in situ some problems related to the vibrational behaviour of reactor vessels or other such huge structures, ELECTRICITY DE FRANCE developed a few years ago, experimental capabilities providing heavy harmonic driving forces, and elaborate data acquisition, signal processing and modal identification software, self-contained in an integrated mobile test facility. The modal analysis techniques we have developed with the LABORATOIRE DE MECANIQUE Appliquee of University of BESANCON (FRANCE) were especially suited for identification of multiple or separation of quasi-multiple modes, i.e. very close and strongly coupled resonances. Besides, the curve fitting methods involved, compute the same complex eigen-frequencies for all the vibration pick-ups, for better accuracy of the related eigen-vector components. Moreover, the latest extensions of these algorithms give us the means to deal with non-linear behaviour. The performances of these programs are drawn from some experimental results on axisymmetric or circularly repetitive structure, we tested in our laboratory to validate the computational hypothesis used in models for seismic responses of breeder reactor vessels. (orig.)

  12. Ectopic germinal centre-like structures in minor salivary gland biopsy predict lymphoma occurrence in patients with primary Sjögren syndrome.

    Science.gov (United States)

    Sène, Damien; Ismael, Sophie; Forien, Marine; Charlotte, Frédéric; Kaci, Rachid; Cacoub, Patrice; Abdourahmane, Diallo; Dieudé, Philippe; Lioté, Frédéric

    2018-04-18

    The objective was to determine risk factors of pSS-associated lymphoma in a multicenter cohort of patients, including in analyzed variables the presence of including ectopic germinal centre-like structures in minor salivary gland biopsy (MSGB). 115 pSS-patients were included and their MSGB were retrospectively examined focusing on the presence of ectopic germinal centre-like structures. Epidemiological, clinical, biological, immunological and histological data were collected at pSS diagnosis. Patients with a Non-Hodgkin Lymphoma (NHL) were compared to those without NHL during the follow-up period, using a Cox proportional hazards multiple regression model. NHL was diagnosed in 8 patients (6.96%), and ectopic germinal centre-like structures in 19 patients (16.5%). The presence of ectopic germinal centre-like structures was associated with a 7.8-fold risk of lymphoma occurrence (95%CI = 1.73-34.86; P = 0.0075). Other independent predictors included positive cryoglobulin (HR = 7.10; 95%CI = 1.74-28.92; P = 0.006), male gender (HR = 28.73; 95%CI = 4.46-144.87; P = 0.0004), sensorimotor neuropathy (HR = 35.48; 95%CI = 5.79-217.39; P = 0.0001) and splenomegaly (HR = 19.9; 95%CI = 4.4-90; P = 0.0001). In addition to traditional clinical and biological predictors, the presence of ectopic germinal centre-like structures in MSGB is associated to the risk of lymphoma occurrence in pSS patients. These data reinforce the major role of MSGB in pSS, for the diagnosis and identification a priori of a subgroup of patients with the highest risk of lymphoma. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  13. An online substructure identification method for local structural health monitoring

    International Nuclear Information System (INIS)

    Hou, Jilin; Ou, Jinping; Jankowski, Łukasz

    2013-01-01

    This paper proposes a substructure isolation method, which uses time series of measured local response for online monitoring of substructures. The proposed monitoring process consists of two key steps: construction of the isolated substructure, and its identification. The isolated substructure is an independent virtual structure, which is numerically isolated from the global structure by placing virtual supports on the interface. First, the isolated substructure is constructed by a specific linear combination of time series of its measured local responses. Then, the isolated substructure is identified using its local natural frequencies extracted from the combined responses. The substructure is assumed to be linear; the outside part of the global structure can have any characteristics. The method has no requirements on the initial state of the structure, and so the process can be carried out repetitively for online monitoring. Online isolation and monitoring is illustrated in a numerical example with a frame model, and then verified in a cantilever beam experiment. (paper)

  14. MODAL TRACKING of A Structural Device: A Subspace Identification Approach

    Energy Technology Data Exchange (ETDEWEB)

    Candy, J. V. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Franco, S. N. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Ruggiero, E. L. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Emmons, M. C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Lopez, I. M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Stoops, L. M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-03-20

    Mechanical devices operating in an environment contaminated by noise, uncertainties, and extraneous disturbances lead to low signal-to-noise-ratios creating an extremely challenging processing problem. To detect/classify a device subsystem from noisy data, it is necessary to identify unique signatures or particular features. An obvious feature would be resonant (modal) frequencies emitted during its normal operation. In this report, we discuss a model-based approach to incorporate these physical features into a dynamic structure that can be used for such an identification. The approach we take after pre-processing the raw vibration data and removing any extraneous disturbances is to obtain a representation of the structurally unknown device along with its subsystems that capture these salient features. One approach is to recognize that unique modal frequencies (sinusoidal lines) appear in the estimated power spectrum that are solely characteristic of the device under investigation. Therefore, the objective of this effort is based on constructing a black box model of the device that captures these physical features that can be exploited to “diagnose” whether or not the particular device subsystem (track/detect/classify) is operating normally from noisy vibrational data. Here we discuss the application of a modern system identification approach based on stochastic subspace realization techniques capable of both (1) identifying the underlying black-box structure thereby enabling the extraction of structural modes that can be used for analysis and modal tracking as well as (2) indicators of condition and possible changes from normal operation.

  15. Structural system identification based on variational mode decomposition

    Science.gov (United States)

    Bagheri, Abdollah; Ozbulut, Osman E.; Harris, Devin K.

    2018-03-01

    In this paper, a new structural identification method is proposed to identify the modal properties of engineering structures based on dynamic response decomposition using the variational mode decomposition (VMD). The VMD approach is a decomposition algorithm that has been developed as a means to overcome some of the drawbacks and limitations of the empirical mode decomposition method. The VMD-based modal identification algorithm decomposes the acceleration signal into a series of distinct modal responses and their respective center frequencies, such that when combined their cumulative modal responses reproduce the original acceleration response. The decaying amplitude of the extracted modal responses is then used to identify the modal damping ratios using a linear fitting function on modal response data. Finally, after extracting modal responses from available sensors, the mode shape vector for each of the decomposed modes in the system is identified from all obtained modal response data. To demonstrate the efficiency of the algorithm, a series of numerical, laboratory, and field case studies were evaluated. The laboratory case study utilized the vibration response of a three-story shear frame, whereas the field study leveraged the ambient vibration response of a pedestrian bridge to characterize the modal properties of the structure. The modal properties of the shear frame were computed using analytical approach for a comparison with the experimental modal frequencies. Results from these case studies demonstrated that the proposed method is efficient and accurate in identifying modal data of the structures.

  16. Secondary structural entropy in RNA switch (Riboswitch) identification.

    Science.gov (United States)

    Manzourolajdad, Amirhossein; Arnold, Jonathan

    2015-04-28

    RNA regulatory elements play a significant role in gene regulation. Riboswitches, a widespread group of regulatory RNAs, are vital components of many bacterial genomes. These regulatory elements generally function by forming a ligand-induced alternative fold that controls access to ribosome binding sites or other regulatory sites in RNA. Riboswitch-mediated mechanisms are ubiquitous across bacterial genomes. A typical class of riboswitch has its own unique structural and biological complexity, making de novo riboswitch identification a formidable task. Traditionally, riboswitches have been identified through comparative genomics based on sequence and structural homology. The limitations of structural-homology-based approaches, coupled with the assumption that there is a great diversity of undiscovered riboswitches, suggests the need for alternative methods for riboswitch identification, possibly based on features intrinsic to their structure. As of yet, no such reliable method has been proposed. We used structural entropy of riboswitch sequences as a measure of their secondary structural dynamics. Entropy values of a diverse set of riboswitches were compared to that of their mutants, their dinucleotide shuffles, and their reverse complement sequences under different stochastic context-free grammar folding models. Significance of our results was evaluated by comparison to other approaches, such as the base-pairing entropy and energy landscapes dynamics. Classifiers based on structural entropy optimized via sequence and structural features were devised as riboswitch identifiers and tested on Bacillus subtilis, Escherichia coli, and Synechococcus elongatus as an exploration of structural entropy based approaches. The unusually long untranslated region of the cotH in Bacillus subtilis, as well as upstream regions of certain genes, such as the sucC genes were associated with significant structural entropy values in genome-wide examinations. Various tests show that there

  17. Frequency Response Function Based Damage Identification for Aerospace Structures

    Science.gov (United States)

    Oliver, Joseph Acton

    Structural health monitoring technologies continue to be pursued for aerospace structures in the interests of increased safety and, when combined with health prognosis, efficiency in life-cycle management. The current dissertation develops and validates damage identification technology as a critical component for structural health monitoring of aerospace structures and, in particular, composite unmanned aerial vehicles. The primary innovation is a statistical least-squares damage identification algorithm based in concepts of parameter estimation and model update. The algorithm uses frequency response function based residual force vectors derived from distributed vibration measurements to update a structural finite element model through statistically weighted least-squares minimization producing location and quantification of the damage, estimation uncertainty, and an updated model. Advantages compared to other approaches include robust applicability to systems which are heavily damped, large, and noisy, with a relatively low number of distributed measurement points compared to the number of analytical degrees-of-freedom of an associated analytical structural model (e.g., modal finite element model). Motivation, research objectives, and a dissertation summary are discussed in Chapter 1 followed by a literature review in Chapter 2. Chapter 3 gives background theory and the damage identification algorithm derivation followed by a study of fundamental algorithm behavior on a two degree-of-freedom mass-spring system with generalized damping. Chapter 4 investigates the impact of noise then successfully proves the algorithm against competing methods using an analytical eight degree-of-freedom mass-spring system with non-proportional structural damping. Chapter 5 extends use of the algorithm to finite element models, including solutions for numerical issues, approaches for modeling damping approximately in reduced coordinates, and analytical validation using a composite

  18. Improving substructure identification accuracy of shear structures using virtual control system

    Science.gov (United States)

    Zhang, Dongyu; Yang, Yang; Wang, Tingqiang; Li, Hui

    2018-02-01

    Substructure identification is a powerful tool to identify the parameters of a complex structure. Previously, the authors developed an inductive substructure identification method for shear structures. The identification error analysis showed that the identification accuracy of this method is significantly influenced by the magnitudes of two key structural responses near a certain frequency; if these responses are unfavorable, the method cannot provide accurate estimation results. In this paper, a novel method is proposed to improve the substructure identification accuracy by introducing a virtual control system (VCS) into the structure. A virtual control system is a self-balanced system, which consists of some control devices and a set of self-balanced forces. The self-balanced forces counterbalance the forces that the control devices apply on the structure. The control devices are combined with the structure to form a controlled structure used to replace the original structure in the substructure identification; and the self-balance forces are treated as known external excitations to the controlled structure. By optimally tuning the VCS’s parameters, the dynamic characteristics of the controlled structure can be changed such that the original structural responses become more favorable for the substructure identification and, thus, the identification accuracy is improved. A numerical example of 6-story shear structure is utilized to verify the effectiveness of the VCS based controlled substructure identification method. Finally, shake table tests are conducted on a 3-story structural model to verify the efficacy of the VCS to enhance the identification accuracy of the structural parameters.

  19. The effects of forest structure on occurrence and abundance of three owl species (Aves: Strigidae in the Central Amazon forest

    Directory of Open Access Journals (Sweden)

    Obed G. Barros

    2009-03-01

    Full Text Available We investigated how forest structure affects the occurrence and abundance of three owl species: the crested owl Lophostrix cristata Daudin, 1800, the Amazon pygmy owl Glaucidium hardyi Vielliard, 1990, and the tawny-bellied screech owl Megascops watsonii Cassin, 1849. We surveyed the owls mostly between 07:00 and 11:00 pm from July 2001 to April 2002, in eighteen 8 km transects along trails at the Ducke Reserve, Manaus, Central Amazon, Brazil. We staked out 50 x 50 m plots where the presence and absence of the owls were recorded. We compared some components of the forest structure between plots where owls were present and plots where they were absent. The spatial variation in these components were related to the occurrence and abundance of the owls using models of multiple logistic and multiple linear regressions analysis, respectively. Lophostrix cristata is rare in many other areas of the Amazon forest, but it was the most abundant in our study area. Lophostrix cristata and G. hardyi were more concentrated along the uplands (central plateau, which divide the reserve into two drainage water-basins. Megascops watsonii was distributed mainly in the southeastern part of the reserve. Glaucidium hardyi was more often found in areas with larger canopy openness. In areas with higher abundance of snags, there was significantly higher occurrence of L. cristata and M. watsonii. Megascops watsonii was also more abundant in areas with higher abundance of forest trees and in areas bearing shallower leaf litter on the forest floor. This study is the first to analyze at large spatial scale the effects of forest structure on neotropical forest top predator nocturnal birds. The results indicate that forest structure can affect the occurrence and abundance of owls in the Amazon forest.

  20. Causal gene identification using combinatorial V-structure search.

    Science.gov (United States)

    Cai, Ruichu; Zhang, Zhenjie; Hao, Zhifeng

    2013-07-01

    With the advances of biomedical techniques in the last decade, the costs of human genomic sequencing and genomic activity monitoring are coming down rapidly. To support the huge genome-based business in the near future, researchers are eager to find killer applications based on human genome information. Causal gene identification is one of the most promising applications, which may help the potential patients to estimate the risk of certain genetic diseases and locate the target gene for further genetic therapy. Unfortunately, existing pattern recognition techniques, such as Bayesian networks, cannot be directly applied to find the accurate causal relationship between genes and diseases. This is mainly due to the insufficient number of samples and the extremely high dimensionality of the gene space. In this paper, we present the first practical solution to causal gene identification, utilizing a new combinatorial formulation over V-Structures commonly used in conventional Bayesian networks, by exploring the combinations of significant V-Structures. We prove the NP-hardness of the combinatorial search problem under a general settings on the significance measure on the V-Structures, and present a greedy algorithm to find sub-optimal results. Extensive experiments show that our proposal is both scalable and effective, particularly with interesting findings on the causal genes over real human genome data. Copyright © 2013 Elsevier Ltd. All rights reserved.

  1. Algorithm of Dynamic Model Structural Identification of the Multivariable Plant

    Directory of Open Access Journals (Sweden)

    Л.М. Блохін

    2004-02-01

    Full Text Available  The new algorithm of dynamic model structural identification of the multivariable stabilized plant with observable and unobservable disturbances in the regular operating  modes is offered in this paper. With the help of the offered algorithm it is possible to define the “perturbed” models of dynamics not only of the plant, but also the dynamics characteristics of observable and unobservable casual disturbances taking into account the absence of correlation between themselves and control inputs with the unobservable perturbations.

  2. Interaction between Floods Occurrence and Gender and Age Structure of Population in Belarus

    Science.gov (United States)

    Partasenok, Irina; Kvach, Alena

    2017-04-01

    The high spring snow-melting or rainfall flooding is the most important and actual event in hydrological cycle for the territory of Belarus. It caused an inundation that means exceeding of water level in the river above safe line and water floods to the adjacent territories. Inundations led to significant destruction of adjoining territories, huge financial damage and threat for human being. The frequencies of spring flooding in Belarus is defined by intensity of river network, its morphometric characteristics and hydrometeorological conditions during the season before floods. The aim of the present study is to estimate the spatial distribution of flood inundation frequency and gender and age structure of national population which might be suffer under extreme phenomena on the rivers. We analysed dangerous thresholds in the river water levels and the frequency of floods of various severity within different river basins, quantity of men and women and their ratio, the quantity of people in the age upper 70 years old as a most sensitive to the flood risk group of population and ratio of rural houses to the entire housing resources as a most vulnerable infrastructure in the different regions of the country. During floods the dangerous levels which cause the inundation have been recorded in the 4 largest river basins passes the territory of Belarus. The most frequent inundations (every two years) occur in the south of the country in the Prypyat` river basin, and in the Dnepr river basin (every 4-5 years) on the majority of the rivers. The hypothesis of our study is that quantity of women population is higher in the flood risk regions (we defined 30 regions with highly frequent inundations) and their ratio high with the age. The majority of them live in potential flood dangerous regions. The strong connections between size of the river basin, its potential flood risk and quantity of population in the region was established. The ratio of men and women over country varied

  3. Structure identification in fuzzy inference using reinforcement learning

    Science.gov (United States)

    Berenji, Hamid R.; Khedkar, Pratap

    1993-01-01

    In our previous work on the GARIC architecture, we have shown that the system can start with surface structure of the knowledge base (i.e., the linguistic expression of the rules) and learn the deep structure (i.e., the fuzzy membership functions of the labels used in the rules) by using reinforcement learning. Assuming the surface structure, GARIC refines the fuzzy membership functions used in the consequents of the rules using a gradient descent procedure. This hybrid fuzzy logic and reinforcement learning approach can learn to balance a cart-pole system and to backup a truck to its docking location after a few trials. In this paper, we discuss how to do structure identification using reinforcement learning in fuzzy inference systems. This involves identifying both surface as well as deep structure of the knowledge base. The term set of fuzzy linguistic labels used in describing the values of each control variable must be derived. In this process, splitting a label refers to creating new labels which are more granular than the original label and merging two labels creates a more general label. Splitting and merging of labels directly transform the structure of the action selection network used in GARIC by increasing or decreasing the number of hidden layer nodes.

  4. Seismic damage identification for steel structures using distributed fiber optics.

    Science.gov (United States)

    Hou, Shuang; Cai, C S; Ou, Jinping

    2009-08-01

    A distributed fiber optic monitoring methodology based on optic time domain reflectometry technology is developed for seismic damage identification of steel structures. Epoxy with a strength closely associated to a specified structure damage state is used for bonding zigzagged configured optic fibers on the surfaces of the structure. Sensing the local deformation of the structure, the epoxy modulates the signal change within the optic fiber in response to the damage state of the structure. A monotonic loading test is conducted on a steel specimen installed with the proposed sensing system using selected epoxy that will crack at the designated strain level, which indicates the damage of the steel structure. Then, using the selected epoxy, a varying degree of cyclic loading amplitudes, which is associated with different damage states, is applied on a second specimen. The test results show that the specimen's damage can be identified by the optic sensors, and its maximum local deformation can be recorded by the sensing system; moreover, the damage evolution can also be identified.

  5. First occurrence of thinlip grey mullet, Liza ramada (Risso, 1827 in the Odra River estuary (NW Poland: genetic identification

    Directory of Open Access Journals (Sweden)

    Remigiusz Panicz

    2016-07-01

    Full Text Available The presence of exotic fish species in the Baltic Sea and its tributaries poses a serious threat for native ichthyofauna, mainly due to the spread of new pathogens. As the accurate identification of species is essential for an effective assessment of changes related to the appearance of non-native species in an aquatic environment, in this paper we tested the usefulness of biometrics and molecular markers in identifying a specimen from the Mugilidae family found in the Odra estuary. The results demonstrated that unambiguous identification of the specimen using biometric features was impossible due to high morphological similarities shared by grey mullets. Unambiguous identification was possible only due to molecular markers, e.g. rhodopsin gene, which helped to identify the collected fish specimen as Liza ramada (Risso, 1827, the first specimen of this species found in the Odra River estuary. The presence of an L. ramada specimen in the Odra River – which could signal the expansion of non-native species into wider ranges – may be linked to climate change or human activity.

  6. Sensor placement optimization for structural modal identification of flexible structures using genetic algorithm

    International Nuclear Information System (INIS)

    Jung, B. K.; Cho, J. R.; Jeong, W. B.

    2015-01-01

    The position of vibration sensors influences the modal identification quality of flexible structures for a given number of sensors, and the quality of modal identification is usually estimated in terms of correlation between the natural modes using the modal assurance criterion (MAC). The sensor placement optimization is characterized by the fact that the design variables are not continuous but discrete, implying that the conventional sensitivity-driven optimization methods are not applicable. In this context, this paper presents the application of genetic algorithm to the sensor placement optimization for improving the modal identification quality of flexible structures. A discrete-type optimization problem using genetic algorithm is formulated by defining the sensor positions and the MAC as the design variables and the objective function, respectively. The proposed GA-based evolutionary optimization method is validated through the numerical experiment with a rectangular plate, and its excellence is verified from the comparison with the cases using different modal correlation measures.

  7. Identification of Damaged Spot Welds in a Complicated Joined Structure

    Energy Technology Data Exchange (ETDEWEB)

    Yunus, M A; Rani, M N Abdul; Ouyang, H; Deng, H; James, S, E-mail: h.ouyang@liverpool.ac.uk [Department of Engineering, Harrison Hughes Building, University of Liverpool, Brownlow Hill, Liverpool L69 3GH (United Kingdom)

    2011-07-19

    In automotive engineering, spot welds on assembled structures such as Body in White (BiW) have a significant effect on the vehicles' dynamic characteristics. Understandably, imperfections in the spot welds will cause variations in the dynamic properties such as natural frequencies and mode shapes of the structure. In this paper, a complicated welded structure which is a simplified Natural Gas Vehicle (NGV) platform is investigated. The structure fabricated from thin metal sheets consists of ten components. They are jointed together by a number of scattered spot welds. NASTRAN Solution 200 based on sensitivity analysis is used to identify the most sensitive parameters to natural frequencies. The numerical model of the undamaged structure is initially updated in order to minimise the discrepancies between the measured and numerical data using NASTRAN optimisation code. The initial updated model serves as a benchmark for the subsequent structural damage identification. The numerical data of the benchmark model is then compared with the measured data obtained from the damaged structure. The same updating procedure is applied to the benchmark model in order to bring the numerical data as close as possible to the measured data of the damaged structure. The disparity in certain parameter values from the parameter values used in the benchmark model shows a fault or damage in the location of a particular joint, depending on the severity of this disparity. The challenge in this work is to localise damaged area and quantify the damage of the complicated structure with multiple spot welds in the presence of uncertainty in the location and material properties of the welds.

  8. Identification of Damaged Spot Welds in a Complicated Joined Structure

    International Nuclear Information System (INIS)

    Yunus, M A; Rani, M N Abdul; Ouyang, H; Deng, H; James, S

    2011-01-01

    In automotive engineering, spot welds on assembled structures such as Body in White (BiW) have a significant effect on the vehicles' dynamic characteristics. Understandably, imperfections in the spot welds will cause variations in the dynamic properties such as natural frequencies and mode shapes of the structure. In this paper, a complicated welded structure which is a simplified Natural Gas Vehicle (NGV) platform is investigated. The structure fabricated from thin metal sheets consists of ten components. They are jointed together by a number of scattered spot welds. NASTRAN Solution 200 based on sensitivity analysis is used to identify the most sensitive parameters to natural frequencies. The numerical model of the undamaged structure is initially updated in order to minimise the discrepancies between the measured and numerical data using NASTRAN optimisation code. The initial updated model serves as a benchmark for the subsequent structural damage identification. The numerical data of the benchmark model is then compared with the measured data obtained from the damaged structure. The same updating procedure is applied to the benchmark model in order to bring the numerical data as close as possible to the measured data of the damaged structure. The disparity in certain parameter values from the parameter values used in the benchmark model shows a fault or damage in the location of a particular joint, depending on the severity of this disparity. The challenge in this work is to localise damaged area and quantify the damage of the complicated structure with multiple spot welds in the presence of uncertainty in the location and material properties of the welds.

  9. Statistical techniques for the identification of reactor component structural vibrations

    International Nuclear Information System (INIS)

    Kemeny, L.G.

    1975-01-01

    The identification, on-line and in near real-time, of the vibration frequencies, modes and amplitudes of selected key reactor structural components and the visual monitoring of these phenomena by nuclear power plant operating staff will serve to further the safety and control philosophy of nuclear systems and lead to design optimisation. The School of Nuclear Engineering has developed a data acquisition system for vibration detection and identification. The system is interfaced with the HIFAR research reactor of the Australian Atomic Energy Commission. The reactor serves to simulate noise and vibrational phenomena which might be pertinent in power reactor situations. The data acquisition system consists of a small computer interfaced with a digital correlator and a Fourier transform unit. An incremental tape recorder is utilised as a backing store and as a means of communication with other computers. A small analogue computer and an analogue statistical analyzer can be used in the pre and post computational analysis of signals which are received from neutron and gamma detectors, thermocouples, accelerometers, hydrophones and strain gauges. Investigations carried out to date include a study of the role of local and global pressure fields due to turbulence in coolant flow and pump impeller induced perturbations on (a) control absorbers, (B) fuel element and (c) coolant external circuit and core tank structure component vibrations. (Auth.)

  10. Comparison Study of Subspace Identification Methods Applied to Flexible Structures

    Science.gov (United States)

    Abdelghani, M.; Verhaegen, M.; Van Overschee, P.; De Moor, B.

    1998-09-01

    In the past few years, various time domain methods for identifying dynamic models of mechanical structures from modal experimental data have appeared. Much attention has been given recently to so-called subspace methods for identifying state space models. This paper presents a detailed comparison study of these subspace identification methods: the eigensystem realisation algorithm with observer/Kalman filter Markov parameters computed from input/output data (ERA/OM), the robust version of the numerical algorithm for subspace system identification (N4SID), and a refined version of the past outputs scheme of the multiple-output error state space (MOESP) family of algorithms. The comparison is performed by simulating experimental data using the five mode reduced model of the NASA Mini-Mast structure. The general conclusion is that for the case of white noise excitations as well as coloured noise excitations, the N4SID/MOESP algorithms perform equally well but give better results (improved transfer function estimates, improved estimates of the output) compared to the ERA/OM algorithm. The key computational step in the three algorithms is the approximation of the extended observability matrix of the system to be identified, for N4SID/MOESP, or of the observer for the system to be identified, for the ERA/OM. Furthermore, the three algorithms only require the specification of one dimensioning parameter.

  11. System Identification of Wind Turbines for Structural Health Monitoring

    DEFF Research Database (Denmark)

    Perisic, Nevena

    Structural health monitoring is a multi-disciplinary engineering field that should allow the actual wind turbine maintenance programmes to evolve to the next level, hence increasing safety and reliability and decreasing turbines downtime. The main idea is to have a sensing system on the structure...... cases are considered, two practical problems from the wind industry are studied, i.e. monitoring of the gearbox shaft torque and the tower root bending moments. The second part of the thesis is focused on the influence of friction on the health of the wind turbine and on the nonlinear identification...... that monitors the system responses and notifies the operator when damages or degradations have been detected. However, some of the response signals that contain important information about the health of the wind turbine components cannot be directly measured, or measuring them is highly complex and costly...

  12. Validation of the measurement model concept for error structure identification

    International Nuclear Information System (INIS)

    Shukla, Pavan K.; Orazem, Mark E.; Crisalle, Oscar D.

    2004-01-01

    The development of different forms of measurement models for impedance has allowed examination of key assumptions on which the use of such models to assess error structure are based. The stochastic error structures obtained using the transfer-function and Voigt measurement models were identical, even when non-stationary phenomena caused some of the data to be inconsistent with the Kramers-Kronig relations. The suitability of the measurement model for assessment of consistency with the Kramers-Kronig relations, however, was found to be more sensitive to the confidence interval for the parameter estimates than to the number of parameters in the model. A tighter confidence interval was obtained for Voigt measurement model, which made the Voigt measurement model a more sensitive tool for identification of inconsistencies with the Kramers-Kronig relations

  13. Novel structural flexibility identification in narrow frequency bands

    International Nuclear Information System (INIS)

    Zhang, J; Moon, F L

    2012-01-01

    A ‘Sub-PolyMAX’ method is proposed in this paper not only for estimating modal parameters, but also for identifying structural flexibility by processing the impact test data in narrow frequency bands. The traditional PolyMAX method obtains denominator polynomial coefficients by minimizing the least square (LS) errors of frequency response function (FRF) estimates over the whole frequency range, but FRF peaks in different structural modes may have different levels of magnitude, which leads to the modal parameters identified for the modes with small FRF peaks being inaccurate. In contrast, the proposed Sub-PolyMAX method implements the LS solver in each subspace of the whole frequency range separately; thus the results identified from a narrow frequency band are not affected by FRF data in other frequency bands. In performing structural identification in narrow frequency bands, not in the whole frequency space, the proposed method has the following merits: (1) it produces accurate modal parameters, even for the modes with very small FRF peaks; (2) it significantly reduces computation cost by reducing the number of frequency lines and the model order in each LS implementation; (3) it accurately identifies structural flexibility from impact test data, from which structural deflection under any static load can be predicted. Numerical and laboratory examples are investigated to verify the effectiveness of the proposed method. (paper)

  14. IDENTIFICATION AND OCCURRENCE OF FUSARIUM SPECIES ON SEEDS OF COMMON WETCH, WHITE LUPINE AND SOME WILD LEGUMES

    Directory of Open Access Journals (Sweden)

    Tihomir Miličević

    2013-06-01

    Full Text Available The presence and occurrence of Fusarium species was examined on the seeds of cultivated legumes – common vetch (Vicia sativa, white lupine (Lupinus albus, and wild legumes: bird’s-foot trefoil (Lotus corniculatus, wild alfalfa (Medicago sativa, black locust (Robinia pseudoacacia, honey locust (Gleditsia triacanthos, sweet clover (Melilotus officinalis, bird vetch (Vicia cracca and meadow vetchling (Lathyrus pratensis. Thirteen Fusarium species were identified - F. verticillioides, F. acuminatum, F. avenaceum, F. tricinctum F. oxysporum, F. scirpi, F. semitectum, F. culmorum, F. proliferatum, F. pseudograminearum, F. sporotrichioides, F. sambucinum and F. heterosporum. Species F. verticillioides and F. proliferatum were determined on seeds of the cultivated legumes (common vetch and white lupine. Other 11 Fusarium species were determined on seeds of wild legumes (bird’s-foot trefoil, wild alfalfa, sweet clover and bird vetch among which the most prevalent were species F. avenaceum and F. acuminatum.

  15. STRUCTURAL IDENTIFICATION OF DISTINCT INVERSIONS OF PLANAR KINEMATIC CHAINS

    Directory of Open Access Journals (Sweden)

    Dr. Shubhashis Sanyal

    2011-12-01

    Full Text Available 0 0 1 171 979 International Islamic University 8 2 1148 14.0 Normal 0 false false false EN-US JA X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Times New Roman";} Inversions are various structural possibilities of a kinematic chain. The number of inversions depends on the number of links of a kinematic chain. At the stage of structural synthesis, identification of distinct structural inversions of a particular type of kinematic chain is necessary. Various researchers have proposed methods for identification of distinct inversions. Present method based on Link joint connectivity is proposed to identify the distinct inversions of a planar kinematic chain. Method is tested successfully on single degree and multiple degree of freedom planar kinematic chains. ABSTRAK: Penyonsangan merupakan kebarangkalian pelbagai struktur suatu rangkaian kinematik. Jumlah songsangan bergantung kepada jumlah hubungan suatu rangkaian kinematik. Pada peringkat sintesis struktur, pengenalan songsangan struktur yang berbeza untuk suatu jenis rangkaian kinematik adalah perlu. Ramai penyelidik telah mencadangkan pelbagai kaedah pengenalan songsangan yang berbeza. Kaedah terkini berdasarkan hubungan kesambungan bersama telah dicadangkan untuk mengenalpasti songsangan yang berbeza dalam suatu satah rangkaian kinematik.

  16. Identification of fullerenes in iron-carbon alloys structure.

    Directory of Open Access Journals (Sweden)

    KUZEEV Iskander Rustemovich

    2017-11-01

    Full Text Available Steels of various purposes are used in the construction industry, for example, as the reinforcement material in reinforced concrete structures. In the oil and gas industry, steel structures are used for storage and transportation of explosive toxic media. In this case the catastrophic damages might take place, that points at insufficiently deep knowledge about the processes running in structural materials when load is applied. Recent studies show that many properties of steel are set at the nanoscale level during crystallization from the molten metal and thermal treatment. To detect and identify fullerenes С60 and С70, which are independent nanoscale objects in steel structure, by various methods requires studying of how these objects influence on formation of steel properties. Iron atoms can serve as a catalyst and, interacting with large aromatic structures or fragments of the graphite planes, they form voluminous fullerene-type structures. The inverse phenomenon, i.e. influence of the formed nanoscale objects on structuring of the iron atoms, is also possible, as fullerene size is comparable with the size of the stable nucleus of the iron crystalline phase. The article discusses the issue of mechanisms of fullerenes formation in steels and cast irons. The most complicated issue in the study is the fullerenes identification by spectral methods as the quantity of released molecules is small. In order to increase the sensitivity of the fullerenes IR-spectrometry method, potassium bromide has been proposed to use. Dried and reduced sediment obtained as a result of dissolving iron matrix in steels is mixed with potassium bromide, the mixture becomes bright-orange. This fact points to presence of bromic fullerenes and to presence of fullerenes in the studied specimens. It is shown that the offered specimen preparation algorithm significantly increases sensitivity of the method.

  17. Occurrence and core-envelope structure of 1-4x Earth-size planets around Sun-like stars

    OpenAIRE

    Marcy, Geoffrey W.; Weiss, Lauren M.; Petigura, Erik A.; Isaacson, Howard; Howard, Andrew W.; Buchhave, Lars A.

    2014-01-01

    Small planets, 1-4x the size of Earth, are extremely common around Sun-like stars, and surprisingly so, as they are missing in our solar system. Recent detections have yielded enough information about this class of exoplanets to begin characterizing their occurrence rates, orbits, masses, densities, and internal structures. The Kepler mission finds the smallest planets to be most common, as 26% of Sun-like stars have small, 1-2 R_e planets with orbital periods under 100 days, and 11% have 1-2...

  18. Microplastic particles in sediments of Lagoon of Venice, Italy: First observations on occurrence, spatial patterns and identification

    Science.gov (United States)

    Vianello, A.; Boldrin, A.; Guerriero, P.; Moschino, V.; Rella, R.; Sturaro, A.; Da Ros, L.

    2013-09-01

    In order to improve knowledge of the identification, distribution and abundances of microplastic particles of 1 mm or less (S-MPPs) in the coastal area of the Mediterranean region, a preliminary monitoring survey was carried out in a transitional environment along the north-eastern Italian coasts, the Lagoon of Venice. S-MPPs were evaluated in sediments collected from 10 sites chosen in shallow areas variously affected by natural conditions and anthropogenic influences (i.e., landward stations influenced by freshwater inputs, seaward areas near sea inlets, and sites influenced by the presence of aquaculture farms, industry and city centers). S-MPPs, extracted from bulk sediments by density separation, were counted and identified by Fourier-Transform Infrared Micro-spectroscopy (μFT-IR). The μFT-IR process included automatic surface chemical mapping and references to an infrared library database to identify the compositional spectra of particles. S-MPPs were recovered from all samples - a fact which emphasizes their extensive distribution throughout the Lagoon. Total abundances varied from 2175 to 672 S-MPPs kg-1 d.w., higher concentrations generally being observed in landward sites. Of the ten polymer types identified, the most abundant, accounting for more than 82% of total S-MPPs, were polyethylene and polypropylene. The most frequent size (93% of observed microplastics) was in the range 30-500 μm. Total S-MPP values were significantly correlated with the finer sediment fraction and with the metal pollution index.

  19. Structural damage identification using piezoelectric impedance measurement with sparse inverse analysis

    Science.gov (United States)

    Cao, Pei; Qi, Shuai; Tang, J.

    2018-03-01

    The impedance/admittance measurements of a piezoelectric transducer bonded to or embedded in a host structure can be used as damage indicator. When a credible model of the healthy structure, such as the finite element model, is available, using the impedance/admittance change information as input, it is possible to identify both the location and severity of damage. The inverse analysis, however, may be under-determined as the number of unknowns in high-frequency analysis is usually large while available input information is limited. The fundamental challenge thus is how to find a small set of solutions that cover the true damage scenario. In this research we cast the damage identification problem into a multi-objective optimization framework to tackle this challenge. With damage locations and severities as unknown variables, one of the objective functions is the difference between impedance-based model prediction in the parametric space and the actual measurements. Considering that damage occurrence generally affects only a small number of elements, we choose the sparsity of the unknown variables as another objective function, deliberately, the l 0 norm. Subsequently, a multi-objective Dividing RECTangles (DIRECT) algorithm is developed to facilitate the inverse analysis where the sparsity is further emphasized by sigmoid transformation. As a deterministic technique, this approach yields results that are repeatable and conclusive. In addition, only one algorithmic parameter, the number of function evaluations, is needed. Numerical and experimental case studies demonstrate that the proposed framework is capable of obtaining high-quality damage identification solutions with limited measurement information.

  20. Structure in continuously cored, deep drill holes at Yucca Mountain, Nevada, with notes on calcite occurrence

    International Nuclear Information System (INIS)

    Carr, W.J.

    1992-12-01

    A study of more than 22,000 feet of core from five deep drill holes at Yucca Mountain, Nevada, provided data on the attitude and vertical distribution of faults and fractures, the sense of fault displacement, and the occurrence of calcite. The study was done mainly to look for evidence of fault flattening at depth, but no consistent downward decrease in dip of faults was found, and no increase in strata rotation was evident with increasing depth. In the two drill holes located near prominent faults that dip toward the holes (USW G-3 and G-2), an apparent increase in the frequency of faults occurs below the tuffs and lavas of Calico Hills. Some of this increase occurs in brittle lavas and flow breccias in the lower part of the volcanic section. In the two holes presumed to be relatively removed from the influence of important faults at depth, the vertical distribution of faults is relatively uniform. Calcite occurs mainly in two general zones, voids in welded portions of the Paintbrush Tuff, and in a deeper zone, mostly below 3,500 feet. Calcite is least abundant in USW G-4, which may reflect the fewer faults and fractures encountered in that drill hole

  1. Identification of a key structural element for protein folding within beta-hairpin turns.

    Science.gov (United States)

    Kim, Jaewon; Brych, Stephen R; Lee, Jihun; Logan, Timothy M; Blaber, Michael

    2003-05-09

    Specific residues in a polypeptide may be key contributors to the stability and foldability of the unique native structure. Identification and prediction of such residues is, therefore, an important area of investigation in solving the protein folding problem. Atypical main-chain conformations can help identify strains within a folded protein, and by inference, positions where unique amino acids may have a naturally high frequency of occurrence due to favorable contributions to stability and folding. Non-Gly residues located near the left-handed alpha-helical region (L-alpha) of the Ramachandran plot are a potential indicator of structural strain. Although many investigators have studied mutations at such positions, no consistent energetic or kinetic contributions to stability or folding have been elucidated. Here we report a study of the effects of Gly, Ala and Asn substitutions found within the L-alpha region at a characteristic position in defined beta-hairpin turns within human acidic fibroblast growth factor, and demonstrate consistent effects upon stability and folding kinetics. The thermodynamic and kinetic data are compared to available data for similar mutations in other proteins, with excellent agreement. The results have identified that Gly at the i+3 position within a subset of beta-hairpin turns is a key contributor towards increasing the rate of folding to the native state of the polypeptide while leaving the rate of unfolding largely unchanged.

  2. Occurrence State and Molecular Structure Analysis of Extracellular Proteins with Implications on the Dewaterability of Waste-Activated Sludge.

    Science.gov (United States)

    Wu, Boran; Ni, Bing-Jie; Horvat, Kristine; Song, Liyan; Chai, Xiaoli; Dai, Xiaohu; Mahajan, Devinder

    2017-08-15

    The occurrence state and molecular structure of extracellular proteins were analyzed to reveal the influencing factors on the water-holding capacities of protein-like substances in waste-activated sludge (WAS). The gelation process of extracellular proteins verified that advanced oxidation processes (AOPs) for WAS dewaterability improvement eliminated the water affinity of extracellular proteins and prevented these macromolecules from forming stable colloidal aggregates. Isobaric tags for relative and absolute quantitation proteomics identified that most of the extracellular proteins were originally derived from the intracellular part and the proteins originally located in the extracellular part were mainly membrane-associated. The main mechanism of extracellular protein transformation during AOPs could be represented by the damage of the membrane or related external encapsulating structure and the release of intracellular substances. For the selected representative extracellular proteins, the strong correlation (R 2 > 0.97, p proteins on the interstitial water removal from WAS.

  3. Identification of genomic indels and structural variations using split reads

    Directory of Open Access Journals (Sweden)

    Urban Alexander E

    2011-07-01

    Full Text Available Abstract Background Recent studies have demonstrated the genetic significance of insertions, deletions, and other more complex structural variants (SVs in the human population. With the development of the next-generation sequencing technologies, high-throughput surveys of SVs on the whole-genome level have become possible. Here we present split-read identification, calibrated (SRiC, a sequence-based method for SV detection. Results We start by mapping each read to the reference genome in standard fashion using gapped alignment. Then to identify SVs, we score each of the many initial mappings with an assessment strategy designed to take into account both sequencing and alignment errors (e.g. scoring more highly events gapped in the center of a read. All current SV calling methods have multilevel biases in their identifications due to both experimental and computational limitations (e.g. calling more deletions than insertions. A key aspect of our approach is that we calibrate all our calls against synthetic data sets generated from simulations of high-throughput sequencing (with realistic error models. This allows us to calculate sensitivity and the positive predictive value under different parameter-value scenarios and for different classes of events (e.g. long deletions vs. short insertions. We run our calculations on representative data from the 1000 Genomes Project. Coupling the observed numbers of events on chromosome 1 with the calibrations gleaned from the simulations (for different length events allows us to construct a relatively unbiased estimate for the total number of SVs in the human genome across a wide range of length scales. We estimate in particular that an individual genome contains ~670,000 indels/SVs. Conclusions Compared with the existing read-depth and read-pair approaches for SV identification, our method can pinpoint the exact breakpoints of SV events, reveal the actual sequence content of insertions, and cover the whole

  4. Landslides Zonation Hazard: relation between geological structures and landslides occurrence in hilly tropical regions of Brazil.

    Science.gov (United States)

    Cerri, Rodrigo I; Reis, Fábio A G V; Gramani, Marcelo F; Giordano, Lucilia C; Zaine, José Eduardo

    2017-01-01

    This paper presents a new approach of landslides zonation hazard studies, based on an integrated study of structural data along with geomorphological and external factors, in a hilly regions of Brazil, covered by a tropical humid rain-forest, called Serra do Mar. The Serra do Mar consists of a hilly region along the east coast of Brazil, with high slopes and many geological structures in a gneiss - migmatitic terrain. In contrast to traditional approaches, this method proposes that structural data (foliation, fractures and bedding planes) and its relation with the slope geometry, is important to be consider in the landslide zonation hazard, along with declivity, relative relief, soil and rock properties, land use and vegetation cover and hydrogeological and climate factors. Results show that slopes with high hazard have the same dip direction of geological structures. Landslide zonation hazard using structural data contributes to a better understanding of how these structures, preserved in tropical residual soils, influence on slope stability and generates landslides.

  5. Landslides Zonation Hazard: relation between geological structures and landslides occurrence in hilly tropical regions of Brazil

    Directory of Open Access Journals (Sweden)

    RODRIGO I. CERRI

    2017-08-01

    Full Text Available ABSTRACT This paper presents a new approach of landslides zonation hazard studies, based on an integrated study of structural data along with geomorphological and external factors, in a hilly regions of Brazil, covered by a tropical humid rain-forest, called Serra do Mar. The Serra do Mar consists of a hilly region along the east coast of Brazil, with high slopes and many geological structures in a gneiss - migmatitic terrain. In contrast to traditional approaches, this method proposes that structural data (foliation, fractures and bedding planes and its relation with the slope geometry, is important to be consider in the landslide zonation hazard, along with declivity, relative relief, soil and rock properties, land use and vegetation cover and hydrogeological and climate factors. Results show that slopes with high hazard have the same dip direction of geological structures. Landslide zonation hazard using structural data contributes to a better understanding of how these structures, preserved in tropical residual soils, influence on slope stability and generates landslides.

  6. Occurrence of the structural enterocin A, P, B, L50B genes in enterococci of different origin.

    Science.gov (United States)

    Strompfová, Viola; Lauková, Andrea; Simonová, Monika; Marcináková, Miroslava

    2008-12-10

    Enterococci are well-known producers of antimicrobial peptides--bacteriocins (enterocins) and the number of characterized enterocins has been significantly increased. Recently, enterocins are of great interest for their potential as biopreservatives in food or feed while research on enterocins as alternative antimicrobials in humans and animals is only at the beginning. The present study provides a survey about the occurrence of enterocin structural genes A, P, B, L50B in a target of 427 strains of Enterococcus faecium (368) and Enterococcus faecalis (59) species from different sources (animal isolates, food and feed) performed by PCR method. Based on our results, 234 strains possessed one or more enterocin structural gene(s). The genes of enterocin P and enterocin A were the most frequently detected structural genes among the PCR positive strains (170 and 155 strains, respectively). Different frequency of the enterocin genes occurrence was detected in strains according to their origin; the strains from horses and silage showed the highest frequency of enterocin genes presence. All possible combinations of the tested genes occurred at least twice except the combination of the gene of enterocin B and L50B which possessed neither strain. The gene of enterocin A was exclusively detected among E. faecium strains, while the gene of enterocin P, B, L50B were detected in strains of both species E. faecium and E. faecalis. In conclusion, a high-frequency and variability of enterocin structural genes exists among enterococci of different origin what offers a big possibility to find effective bacteriocin-producing strains for their application in veterinary medicine.

  7. Occurrence of the dayside three-peak density structure in the F2 and the topside ionosphere

    Science.gov (United States)

    Astafyeva, Elvira; Zakharenkova, Irina; Pineau, Yann

    2016-07-01

    In this work, we discuss the occurrence of the dayside three-peak electron density structure in the ionosphere. We first use a set of ground-based and satellite-borne instruments to demonstrate the development of a large-amplitude electron density perturbation at the recovery phase of a moderate storm of 11 October 2008. The perturbation developed in the F2 and low topside ionospheric regions over the American sector; it was concentrated on the north from the equatorial ionization anomaly (EIA) but was clearly separated from it. At the F2 region height, the amplitude of the observed perturbation was comparable or even exceeded that of the EIA. Further analysis of the observational data together with the Coupled Thermosphere Ionosphere Plasmasphere Electrodynamics model simulation results showed that a particular local combination of the thermospheric wind surges provided favorable conditions for the generation of the three-peak EIA structure. We further proceed with a statistical study of occurrence of the three-peak density structure in the ionosphere in general. Based on the analysis of 7 years of the in situ data from CHAMP satellite, we found that such three-peak density structure occurs sufficiently often during geomagnetically quiet time. The third ionization peak develops in the afternoon hours in the summer hemisphere at solstice periods. Based on analysis of several quiet time events, we conclude that during geomagnetically quiet time, the prevailing summer-to-winter thermospheric circulation acts in similar manner as the storm-time enhanced thermospheric winds, playing the decisive role in generation of the third ionization peak in the daytime ionosphere.

  8. Substructure identification for shear structures: cross-power spectral density method

    International Nuclear Information System (INIS)

    Zhang, Dongyu; Johnson, Erik A

    2012-01-01

    In this paper, a substructure identification method for shear structures is proposed. A shear structure is divided into many small substructures; utilizing the dynamic equilibrium of a one-floor substructure, an inductive identification problem is formulated, using the cross-power spectral densities between structural floor accelerations and a reference response, to estimate the parameters of that one story. Repeating this procedure, all story parameters of the shear structure are identified from top to bottom recursively. An identification error analysis is performed for the proposed substructure method, revealing how uncertain factors (e.g. measurement noise) in the identification process affect the identification accuracy. According to the error analysis, a smart reference selection rule is designed to choose the optimal reference response that further enhances the identification accuracy. Moreover, based on the identification error analysis, explicit formulae are developed to calculate the variances of the parameter identification errors. A ten-story shear structure is used to illustrate the effectiveness of the proposed substructure method. The simulation results show that the method, combined with the reference selection rule, can very accurately identify structural parameters despite large measurement noise. Furthermore, the proposed formulae provide good predictions for the variances of the parameter identification errors, which are vital for providing accurate warnings of structural damage. (paper)

  9. Locating and classification of structure-borne sound occurrence using wavelet transformation

    International Nuclear Information System (INIS)

    Winterstein, Martin; Thurnreiter, Martina

    2011-01-01

    For the surveillance of nuclear facilities with respect to detached or loose parts within the pressure boundary structure-borne sound detector systems are used. The impact of loose parts on the wall causes energy transfer to the wall that is measured a so called singular sound event. The run-time differences of sound signals allow a rough locating of the loose part. The authors performed a finite element based simulation of structure-borne sound measurements using real geometries. New knowledge on sound wave propagation, signal analysis and processing, neuronal networks or hidden Markov models were considered. Using the wavelet transformation it is possible to improve the localization of structure-borne sound events.

  10. Identification of Civil Engineering Structures using Multivariate ARMAV and RARMAV Models

    DEFF Research Database (Denmark)

    Kirkegaard, Poul Henning; Andersen, P.; Brincker, Rune

    This paper presents how to make system identification of civil engineering structures using multivariate auto-regressive moving-average vector (ARMAV) models. Further, the ARMAV technique is extended to a recursive technique (RARMAV). The ARMAV model is used to identify measured stationary data....... The results show the usefulness of the approaches for identification of civil engineering structures excited by natural excitation...

  11. pi-Turns: types, systematics and the context of their occurrence in protein structures.

    Science.gov (United States)

    Dasgupta, Bhaskar; Chakrabarti, Pinak

    2008-09-22

    For a proper understanding of protein structure and folding it is important to know if a polypeptide segment adopts a conformation inherent in the sequence or it depends on the context of its flanking secondary structures. Turns of various lengths have been studied and characterized starting from three-residue gamma-turn to six-residue pi-turn. The Schellman motif occurring at the C-terminal end of alpha-helices is a classical example of hydrogen bonded pi-turn involving residues at (i) and (i+5) positions. Hydrogen bonded and non-hydrogen bonded beta- and alpha-turns have been identified previously; likewise, a systematic characterization of pi-turns would provide valuable insight into turn structures. An analysis of protein structures indicates that at least 20% of pi-turns occur independent of the Schellman motif. The two categories of pi-turns, designated as pi-HB and SCH, have been further classified on the basis of backbone conformation and both have AAAa as the major class. They differ in the residue usage at position (i+1), the former having a large preference for Pro that is absent in the latter. As in the case of shorter length beta- and alpha-turns, pi-turns have also been identified not only on the basis of the existence of hydrogen bond, but also using the distance between terminal C alpha-atoms, and this resulted in a comparable number of non-hydrogen-bonded pi-turns (pi-NHB). The presence of shorter beta- and alpha-turns within all categories of pi-turns, the subtle variations in backbone torsion angles along the turn residues, the location of the turns in the context of tertiary structures have been studied. pi-turns have been characterized, first using hydrogen bond and the distance between C alpha atoms of the terminal residues, and then using backbone torsion angles. While the Schellman motif has a structural role in helix termination, many of the pi-HB turns, being located on surface cavities, have functional role and there is also sequence

  12. Identification of Civil Engineering Structures using Vector ARMA Models

    DEFF Research Database (Denmark)

    Andersen, P.

    The dissertation treats the matter of systems identification and modelling of load-bearing constructions using Auto-Regressive Moving Average Vector (ARMAV) models.......The dissertation treats the matter of systems identification and modelling of load-bearing constructions using Auto-Regressive Moving Average Vector (ARMAV) models....

  13. Structure of a fragment of Atlantic Rainforest in regeneration with occurrence of Caesalpinia echinata Lam. (brazil-wood

    Directory of Open Access Journals (Sweden)

    Liliane Baldan Zani

    2012-11-01

    Full Text Available This study aimed to evaluate the phytosociological structure of a remaining fragment of Atlantic Rainforest undergoing regeneration in the town of Aracruz-ES in a forest board with natural occurrence of Caesalpinia echinata Lam. We installed 10 sample units (plots of 10 x 50m, sampling all individuals with DBH≥5cm and <10cm. Altogether, we sampled 500 individuals distributed into 181 species. The richest families were Leguminosae (35, Sapotaceae (18, and Myrtaceae (14. The most important species were Caesalpinia echinata Lam., Eugenia tinguyensis Cambess., and Pterocarpus rohrii Vahl. The Shannon index (H’ was 4.89 and the equability (J’ was 0.94. This area is one of the last remaining fragments with brazil-wood from the state of Espirito Santo and the population of this species is well preserved at the site, it occurs very frequently, emphasizing the importance of preserving small forest fragments to conserve biodiversity.

  14. Development of structural vulnerability curve associated with high magnitude torrent occurrences in Switzerland

    Science.gov (United States)

    Wing-Yuen Chow, Candace; Bründl, Michael; Keiler, Margreth

    2017-04-01

    In mountain regions, high economic losses have increased significantly in the past decades due to severe hazard processes, in spite of notable investments in hazard management. Assessing the vulnerability of built structures to high magnitude torrent events is a part of consequence analysis, where hazard intensity is related to the degree of loss sustained. While vulnerability curves have been developed for different countries, the presented work contributes new data from Swiss-based case studies that address a known gap associated with the consequences of high magnitude events. Data for this stage of the investigation communicates the degree of loss associated with affected structures and has been provided by local authorities dealing with natural hazards (e.g. Amt für Wald des Kantons Bern (KAWA) and cantonal insurance providers). Information used for the empirical quantification of vulnerability to torrent processes is derived from detailed post-event documentation and the loss database and verified with field visits. Building the initial database supports data sharing and the systematic inclusion of additional case studies as they become available. The collection of this new data is fundamental to the development of a local vulnerability curve based on observed sediment deposition heights, a proxy for describing hazard intensity. The result will then be compared to curves derived from Austrian and Italian datasets.

  15. The occurrence of pycnogonids associated with the volcanic structures of Bransfield Strait central basin (Antarctica

    Directory of Open Access Journals (Sweden)

    Tomás Munilla

    2007-12-01

    Full Text Available Fifty-four specimens of pycnogonids belonging to twenty-two species, eight genera and six families were collected with a rocky dredge during the cruise Gebrap-96 in the central basin of Bransfield Strait, from depths between 647 and 1592 m. The richest station in terms of abundance and biomass was DR6 (south of Livingston Island, which was also the shallowest one; at this relatively shallow depth food is more available than in deeper waters. The families Nymphonidae and Colossendeidae had the same number of specimens (21 specimens; 39% abundance each. The most abundant species were Nymphon villosum and N. proximum. Pallenopsis buphthalmus was collected for only the third time. The collections increased the geographical distribution of three species and the depth range of six species. The volcanic structures sampled were inactive during 1996, since none of the specimens showed signs of hydrothermal phenomena. This collection was typically representative of the west Antarctic benthic zone.

  16. Structure, Variation, and Co-occurrence of Soil Microbial Communities in Abandoned Sites of a Rare Earth Elements Mine.

    Science.gov (United States)

    Chao, Yuanqing; Liu, Wenshen; Chen, Yanmei; Chen, Wenhui; Zhao, Lihua; Ding, Qiaobei; Wang, Shizhong; Tang, Ye-Tao; Zhang, Tong; Qiu, Rong-Liang

    2016-11-01

    Mining activity for rare earth elements (REEs) has caused serious environmental pollution, particularly for soil ecosystems. However, the effects of REEs on soil microbiota are still poorly understood. In this study, soils were collected from abandoned sites of a REEs mine, and the structure, diversity, and co-occurrence patterns of soil microbiota were evaluated by Illumina high-throughput sequencing targeting 16S rRNA genes. Although microbiota developed significantly along with the natural restoration, the microbial structure on the site abandoned for 10 years still significantly differed from that on the unmined site. Potential plant growth promoting bacteria (PGPB) were identified by comparing 16S sequences against a self-constructed PGPB database via BLAST, and it was found that siderophore-producing and phosphorus-solubilizing bacteria were more abundant in the studied soils than in reference soils. Canonical correspondence analysis indicated that species richness of plant community was the prime factor affecting microbial structure, followed by limiting nutrients (total carbon and total nitrogen) and REEs content. Further co-occurring network analysis revealed nonrandom assembly patterns of microbiota in the studied soils. These results increase our understanding of microbial variation and assembly pattern during natural restoration in REE contaminated soils.

  17. Test of the beam effect on vacuum arc occurrence in a high-gradient accelerating structure for the CLIC project

    CERN Document Server

    AUTHOR|(CDS)2130409; Gagliardi, Martino

    A new generation of lepton colliders capable of reaching TeV energies is pres- ently under development, and to succeed in this task it is necessary to show that the technology for such a machine is available. The Compact Linear Collider (CLIC) is a possible design option among the future lepton collider projects. It consists of two normal-conducting linacs. Accelerating structures with a gradient of the order of 100 MV/m are necessary to reach the required high energies within a reasonable machine length. One of the strictest require- ments for such accelerating structures is a relatively low occurrence of vacuum arcs. CLIC prototype structures have been tested in the past, but only in absence of beam. In order to proof the feasibility of the high gradient technology for building a functional collider, it is necessary to understand the effect of the beam presence on the vacuum breakdowns. Tests of this type have never been performed previously. The main goal of this work is to provide a first measurement of t...

  18. Direct Linear System Identification Method for Multistory Three-dimensional Building Structure with General Eccentricity

    OpenAIRE

    Shintani, Kenichirou; Yoshitomi, Shinta; Takewaki, Izuru

    2017-01-01

    A method of physical parameter system identification (SI) is proposed here for three-dimensional (3D) building structures with in-plane rigid floors in which the stiffness and damping coefficients of each structural frame in the 3D building structure are identified from the measured floor horizontal accelerations. A batch processing least-squares estimation method for many discrete time domain measured data is proposed for the direct identification of the stiffness and damping coefficients of...

  19. [Structural CNS abnormalities responsible for coincidental occurrence of endocrine disorders, epilepsy and psychoneurologic disorders in children and adolescents].

    Science.gov (United States)

    Starzyk, Jerzy; Kwiatkowski, Stanisław; Kaciński, Marek; Kroczka, Sławomir; Wójcik, Małgorzata

    2010-01-01

    In the population of children and adolescents, epilepsy affects 0.5-1% of individuals; approximately 3% of general population suffer from non-epileptic seizures, while endocrine disorders are several times more frequent. All of the above factors result in a relatively common non-accidental occurrence of endocrine disorders, epilepsy and neuropsychiatric disorders. However, structural central nervous system (CNS) abnormalities that cause both endocrine and neurologic disorders seem to be markedly less common. No reports addressing this problem are available in the literature. 1) Assessment of the frequency of non-coincidental occurrence of epilepsy and endocrine disorders in inpatients and outpatients with structural CSN abnormalities managed in Department Endocrinology. 2) Presentation of diagnostic and therapeutic difficulties in these patients, and 3) An attempt at defining a common etiology of both disorders. A retrospective analysis of the medical records of the patients with coincidence of endocrine disorders and epilepsy and psycho-neurologic disorders (treated in Chair and Department of Children's and Adolescents Neurology, University Children's Hospital of Krakow or in another pediatric neurology center) and with organic CNS abnormalities (treated or followed up as inpatients and outpatient of Department of Pediatric Surgery, Children's University Hospital of Krakow, was performed. The patients were selected from among several thousands of children treated as inpatients and outpatients of the Department. Various forms of symptomatic and idiopathic epilepsy and other psychoneurological disorders (disorders of behavior and emotions, obsession-compulsion syndromes, stereotypias, aggression, compulsive ideas and movements, anorexia or hypothalamic obesity) coincident with one or more endocrine disorders such as precocious or delayed puberty, multihormonal pituitary deficiency, panhypopituitarism and secondary hypothyroidism were detected in 42 patients with

  20. Environmental occurrences

    International Nuclear Information System (INIS)

    Black, D.G.

    1995-01-01

    This section of the 1994 Hanford Site Environmental Report summarizes the onsite and offsite releases of radioactive and regulated materials. The specific agencies notified of the releases depended on the type, amount, and location of the individual occurrences. The more significant of these off-normal environmental occurrences are summarized in this section

  1. Environmental occurrences

    Energy Technology Data Exchange (ETDEWEB)

    Black, D.G.

    1995-06-01

    This section of the 1994 Hanford Site Environmental Report summarizes the onsite and offsite releases of radioactive and regulated materials. The specific agencies notified of the releases depended on the type, amount, and location of the individual occurrences. The more significant of these off-normal environmental occurrences are summarized in this section.

  2. Research on FBG-Based CFRP Structural Damage Identification Using BP Neural Network

    Science.gov (United States)

    Geng, Xiangyi; Lu, Shizeng; Jiang, Mingshun; Sui, Qingmei; Lv, Shanshan; Xiao, Hang; Jia, Yuxi; Jia, Lei

    2018-06-01

    A damage identification system of carbon fiber reinforced plastics (CFRP) structures is investigated using fiber Bragg grating (FBG) sensors and back propagation (BP) neural network. FBG sensors are applied to construct the sensing network to detect the structural dynamic response signals generated by active actuation. The damage identification model is built based on the BP neural network. The dynamic signal characteristics extracted by the Fourier transform are the inputs, and the damage states are the outputs of the model. Besides, damages are simulated by placing lumped masses with different weights instead of inducing real damages, which is confirmed to be feasible by finite element analysis (FEA). At last, the damage identification system is verified on a CFRP plate with 300 mm × 300 mm experimental area, with the accurate identification of varied damage states. The system provides a practical way for CFRP structural damage identification.

  3. Identification of similar regions of protein structures using integrated sequence and structure analysis tools

    Directory of Open Access Journals (Sweden)

    Heiland Randy

    2006-03-01

    Full Text Available Abstract Background Understanding protein function from its structure is a challenging problem. Sequence based approaches for finding homology have broad use for annotation of both structure and function. 3D structural information of protein domains and their interactions provide a complementary view to structure function relationships to sequence information. We have developed a web site http://www.sblest.org/ and an API of web services that enables users to submit protein structures and identify statistically significant neighbors and the underlying structural environments that make that match using a suite of sequence and structure analysis tools. To do this, we have integrated S-BLEST, PSI-BLAST and HMMer based superfamily predictions to give a unique integrated view to prediction of SCOP superfamilies, EC number, and GO term, as well as identification of the protein structural environments that are associated with that prediction. Additionally, we have extended UCSF Chimera and PyMOL to support our web services, so that users can characterize their own proteins of interest. Results Users are able to submit their own queries or use a structure already in the PDB. Currently the databases that a user can query include the popular structural datasets ASTRAL 40 v1.69, ASTRAL 95 v1.69, CLUSTER50, CLUSTER70 and CLUSTER90 and PDBSELECT25. The results can be downloaded directly from the site and include function prediction, analysis of the most conserved environments and automated annotation of query proteins. These results reflect both the hits found with PSI-BLAST, HMMer and with S-BLEST. We have evaluated how well annotation transfer can be performed on SCOP ID's, Gene Ontology (GO ID's and EC Numbers. The method is very efficient and totally automated, generally taking around fifteen minutes for a 400 residue protein. Conclusion With structural genomics initiatives determining structures with little, if any, functional characterization

  4. Optimal Design of Experiments for Parametric Identification of Civil Engineering Structures

    DEFF Research Database (Denmark)

    Kirkegaard, Poul Henning

    Optimal Systems of experiments for parametric identification of civil engineering structures is investigated. Design of experiments for parametric identification of dynamic systems is usually done by minimizing a scalar measure, e.g the determinant, the trace ect., of an estimated parameter...

  5. Structural System Identification with Extended Kalman Filter and Orthogonal Decomposition of Excitation

    Directory of Open Access Journals (Sweden)

    Y. Ding

    2014-01-01

    Full Text Available Both the structural parameter and external excitation have coupling influence on structural response. A new system identification method in time domain is proposed to simultaneously evaluate structural parameter and external excitation. The method can be used for linear and hysteresis nonlinear structural condition assessment based on incomplete structural responses. In this method, the structural excitation is decomposed by orthogonal approximation. With this approximation, the strongly time-variant excitation identification is transformed to gentle time-variant, even constant parameters identification. Then the extended Kalman filter is applied to simultaneously identify state vector including the structural parameters and excitation orthogonal parameters in state space based on incomplete measurements. The proposed method is validated numerically with the simulation of three-story linear and nonlinear structures subject to external force. The external force on the top floor and the structural parameters are simultaneously identified with the proposed system identification method. Results from both simulations indicate that the proposed method is capable of identifing the dynamic load and structural parameters fairly accurately with contaminated incomplete measurement for both of the linear and nonlinear structural systems.

  6. A comprehensive analysis of the Omp85/TpsB protein superfamily structural diversity, taxonomic occurrence, and evolution

    Science.gov (United States)

    Heinz, Eva; Lithgow, Trevor

    2014-01-01

    Members of the Omp85/TpsB protein superfamily are ubiquitously distributed in Gram-negative bacteria, and function in protein translocation (e.g., FhaC) or the assembly of outer membrane proteins (e.g., BamA). Several recent findings are suggestive of a further level of variation in the superfamily, including the identification of the novel membrane protein assembly factor TamA and protein translocase PlpD. To investigate the diversity and the causal evolutionary events, we undertook a comprehensive comparative sequence analysis of the Omp85/TpsB proteins. A total of 10 protein subfamilies were apparent, distinguished in their domain structure and sequence signatures. In addition to the proteins FhaC, BamA, and TamA, for which structural and functional information is available, are families of proteins with so far undescribed domain architectures linked to the Omp85 β-barrel domain. This study brings a classification structure to a dynamic protein superfamily of high interest given its essential function for Gram-negative bacteria as well as its diverse domain architecture, and we discuss several scenarios of putative functions of these so far undescribed proteins. PMID:25101071

  7. Reframing measurement for structural health monitoring: a full-field strategy for structural identification

    Science.gov (United States)

    Dizaji, Mehrdad S.; Harris, Devin K.; Alipour, Mohamad; Ozbulut, Osman E.

    2018-03-01

    Structural health monitoring (SHM) describes a decision-making framework that is fundamentally guided by state change detection of structural systems. This framework typically relies on the use of continuous or semi-continuous monitoring of measured response to quantify this state change in structural system behavior, which is often related to the initiation of some form of damage. Measurement approaches used for traditional SHM are numerous, but most are limited to either describing localized or global phenomena, making it challenging to characterize operational structural systems which exhibit both. In addition to these limitations in sensing, SHM has also suffered from the inherent robustness inherent to most full-scale structural systems, making it challenging to identify local damage. These challenges highlight the opportunity for alternative strategies for SHM, strategies that are able to provide data suitable to translate into rich information. This paper describes preliminary results from a refined structural identification (St-ID) approach using fullfield measurements derived from high-speed 3D Digital Image Correlation (HSDIC) to characterize uncertain parameters (i.e. boundary and constitutive properties) of a laboratory scale structural component. The St-ID approach builds from prior work by supplementing full-field deflection and strain response with vibration response derived from HSDIC. Inclusion of the modal characteristics within a hybrid-genetic algorithm optimization scheme allowed for simultaneous integration of mechanical and modal response, thus enabling a more robust St-ID strategy than could be achieved with traditional sensing techniques. The use of full-field data is shown to provide a more comprehensive representation of the global and local behavior, which in turn increases the robustness of the St-Id framework. This work serves as the foundation for a new paradigm in SHM that emphasizes characterizing structural performance using a

  8. Experiment design for identification of structured linear systems

    NARCIS (Netherlands)

    Potters, M.G.

    2016-01-01

    Experiment Design for system identification involves the design of an optimal input signal with the purpose of accurately estimating unknown parameters in a system. Specifically, in the Least-Costly Experiment Design (LCED) framework, the optimal input signal results from an optimisation problem in

  9. Identification and estimation of non-Gaussian structural vector autoregressions

    DEFF Research Database (Denmark)

    Lanne, Markku; Meitz, Mika; Saikkonen, Pentti

    -Gaussian components is, without any additional restrictions, identified and leads to (essentially) unique impulse responses. We also introduce an identification scheme under which the maximum likelihood estimator of the non-Gaussian SVAR model is consistent and asymptotically normally distributed. As a consequence......, additional economic identifying restrictions can be tested. In an empirical application, we find a negative impact of a contractionary monetary policy shock on financial markets, and clearly reject the commonly employed recursive identifying restrictions....

  10. Identification of fractional-order systems with unknown initial values and structure

    Energy Technology Data Exchange (ETDEWEB)

    Du, Wei, E-mail: duwei0203@gmail.com [Key Laboratory of Advanced Control and Optimization for Chemical Processes, Ministry of Education, East China University of Science and Technology, Shanghai 200237 (China); Miao, Qingying, E-mail: qymiao@sjtu.edu.cn [School of Continuing Education, Shanghai Jiao Tong University, Shanghai 200030 (China); Tong, Le, E-mail: tongle0328@gmail.com [Faculty of Applied Science and Textiles, The Hong Kong Polytechnic University, Hong Kong (China); Tang, Yang [Key Laboratory of Advanced Control and Optimization for Chemical Processes, Ministry of Education, East China University of Science and Technology, Shanghai 200237 (China)

    2017-06-21

    In this paper, the identification problem of fractional-order chaotic systems is proposed and investigated via an evolutionary optimization approach. Different with other studies to date, this research focuses on the identification of fractional-order chaotic systems with not only unknown orders and parameters, but also unknown initial values and structure. A group of fractional-order chaotic systems, i.e., Lorenz, Lü, Chen, Rössler, Arneodo and Volta chaotic systems, are set as the system candidate pool. The identification problem of fractional-order chaotic systems in this research belongs to mixed integer nonlinear optimization in essence. A powerful evolutionary algorithm called composite differential evolution (CoDE) is introduced for the identification problem presented in this paper. Extensive experiments are carried out to show that the fractional-order chaotic systems with unknown initial values and structure can be successfully identified by means of CoDE. - Highlights: • Unknown initial values and structure are introduced in the identification of fractional-order chaotic systems; • Only a series of output is utilized in the identification of fractional-order chaotic systems; • CoDE is used for the identification problem and the results are satisfactory when compared with other DE variants.

  11. Frequency response function-based explicit framework for dynamic identification in human-structure systems

    Science.gov (United States)

    Wei, Xiaojun; Živanović, Stana

    2018-05-01

    The aim of this paper is to propose a novel theoretical framework for dynamic identification in a structure occupied by a single human. The framework enables the prediction of the dynamics of the human-structure system from the known properties of the individual system components, the identification of human body dynamics from the known dynamics of the empty structure and the human-structure system and the identification of the properties of the structure from the known dynamics of the human and the human-structure system. The novelty of the proposed framework is the provision of closed-form solutions in terms of frequency response functions obtained by curve fitting measured data. The advantages of the framework over existing methods are that there is neither need for nonlinear optimisation nor need for spatial/modal models of the empty structure and the human-structure system. In addition, the second-order perturbation method is employed to quantify the effect of uncertainties in human body dynamics on the dynamic identification of the empty structure and the human-structure system. The explicit formulation makes the method computationally efficient and straightforward to use. A series of numerical examples and experiments are provided to illustrate the working of the method.

  12. Beyond habitat structure: Landscape heterogeneity explains the monito del monte (Dromiciops gliroides) occurrence and behavior at habitats dominated by exotic trees.

    Science.gov (United States)

    Salazar, Daniela A; Fontúrbel, Francisco E

    2016-09-01

    Habitat structure determines species occurrence and behavior. However, human activities are altering natural habitat structure, potentially hampering native species due to the loss of nesting cavities, shelter or movement pathways. The South American temperate rainforest is experiencing an accelerated loss and degradation, compromising the persistence of many native species, and particularly of the monito del monte (Dromiciops gliroides Thomas, 1894), an arboreal marsupial that plays a key role as seed disperser. Aiming to compare 2 contrasting habitats (a native forest and a transformed habitat composed of abandoned Eucalyptus plantations and native understory vegetation), we assessed D. gliroides' occurrence using camera traps and measured several structural features (e.g. shrub and bamboo cover, deadwood presence, moss abundance) at 100 camera locations. Complementarily, we used radio telemetry to assess its spatial ecology, aiming to depict a more complete scenario. Moss abundance was the only significant variable explaining D. gliroides occurrence between habitats, and no structural variable explained its occurrence at the transformed habitat. There were no differences in home range, core area or inter-individual overlapping. In the transformed habitats, tracked individuals used native and Eucalyptus-associated vegetation types according to their abundance. Diurnal locations (and, hence, nesting sites) were located exclusively in native vegetation. The landscape heterogeneity resulting from the vicinity of native and Eucalyptus-associated vegetation likely explains D. gliroides occurrence better than the habitat structure itself, as it may be use Eucalyptus-associated vegetation for feeding purposes but depend on native vegetation for nesting. © 2016 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and John Wiley & Sons Australia, Ltd.

  13. On the Structural Context and Identification of Enzyme Catalytic Residues

    Directory of Open Access Journals (Sweden)

    Yu-Tung Chien

    2013-01-01

    Full Text Available Enzymes play important roles in most of the biological processes. Although only a small fraction of residues are directly involved in catalytic reactions, these catalytic residues are the most crucial parts in enzymes. The study of the fundamental and unique features of catalytic residues benefits the understanding of enzyme functions and catalytic mechanisms. In this work, we analyze the structural context of catalytic residues based on theoretical and experimental structure flexibility. The results show that catalytic residues have distinct structural features and context. Their neighboring residues, whether sequence or structure neighbors within specific range, are usually structurally more rigid than those of noncatalytic residues. The structural context feature is combined with support vector machine to identify catalytic residues from enzyme structure. The prediction results are better or comparable to those of recent structure-based prediction methods.

  14. Occurrence and core-envelope structure of 1-4× Earth-size planets around Sun-like stars.

    Science.gov (United States)

    Marcy, Geoffrey W; Weiss, Lauren M; Petigura, Erik A; Isaacson, Howard; Howard, Andrew W; Buchhave, Lars A

    2014-09-02

    Small planets, 1-4× the size of Earth, are extremely common around Sun-like stars, and surprisingly so, as they are missing in our solar system. Recent detections have yielded enough information about this class of exoplanets to begin characterizing their occurrence rates, orbits, masses, densities, and internal structures. The Kepler mission finds the smallest planets to be most common, as 26% of Sun-like stars have small, 1-2 R⊕ planets with orbital periods under 100 d, and 11% have 1-2 R⊕ planets that receive 1-4× the incident stellar flux that warms our Earth. These Earth-size planets are sprinkled uniformly with orbital distance (logarithmically) out to 0.4 the Earth-Sun distance, and probably beyond. Mass measurements for 33 transiting planets of 1-4 R⊕ show that the smallest of them, R planets. Their densities increase with increasing radius, likely caused by gravitational compression. Including solar system planets yields a relation: ρ = 2:32 + 3:19 R=R ⊕ [g cm(-3)]. Larger planets, in the radius range 1.5-4.0 R⊕, have densities that decline with increasing radius, revealing increasing amounts of low-density material (H and He or ices) in an envelope surrounding a rocky core, befitting the appellation ''mini-Neptunes.'' The gas giant planets occur preferentially around stars that are rich in heavy elements, while rocky planets occur around stars having a range of heavy element abundances. Defining habitable zones remains difficult, without benefit of either detections of life elsewhere or an understanding of life's biochemical origins.

  15. Occurrence and core-envelope structure of 1–4× Earth-size planets around Sun-like stars

    Science.gov (United States)

    Marcy, Geoffrey W.; Weiss, Lauren M.; Petigura, Erik A.; Isaacson, Howard; Howard, Andrew W.; Buchhave, Lars A.

    2014-01-01

    Small planets, 1–4× the size of Earth, are extremely common around Sun-like stars, and surprisingly so, as they are missing in our solar system. Recent detections have yielded enough information about this class of exoplanets to begin characterizing their occurrence rates, orbits, masses, densities, and internal structures. The Kepler mission finds the smallest planets to be most common, as 26% of Sun-like stars have small, 1–2 R⊕ planets with orbital periods under 100 d, and 11% have 1–2 R⊕ planets that receive 1–4× the incident stellar flux that warms our Earth. These Earth-size planets are sprinkled uniformly with orbital distance (logarithmically) out to 0.4 the Earth–Sun distance, and probably beyond. Mass measurements for 33 transiting planets of 1–4 R⊕ show that the smallest of them, R planets. Their densities increase with increasing radius, likely caused by gravitational compression. Including solar system planets yields a relation: ρ=2.32+3.19R/R⊕ [g cm−3]. Larger planets, in the radius range 1.5–4.0 R⊕, have densities that decline with increasing radius, revealing increasing amounts of low-density material (H and He or ices) in an envelope surrounding a rocky core, befitting the appellation ‘‘mini-Neptunes.’’ The gas giant planets occur preferentially around stars that are rich in heavy elements, while rocky planets occur around stars having a range of heavy element abundances. Defining habitable zones remains difficult, without benefit of either detections of life elsewhere or an understanding of life’s biochemical origins. PMID:24912169

  16. Identification of Civil Engineering Structures using Vector ARMA Models

    DEFF Research Database (Denmark)

    Andersen, Palle; Brincker, Rune; Kirkegaard, Poul Henning

    1998-01-01

    This paper describes the work which have been carried out in the project B.1: Damage Detection in Structures under Random Loading. The project is a part of the research programme Dynamics of Structures founded by the Danish Technical Research Council. The planned contents of and the requirements ...... Dept. of Building Technology and Structural Engineering, Aalborg University....

  17. Coral species identification and occurrences from sites at Mandano and Wakatobi, Sulawesi, Indonesia and Raiatea, Society Islands, French Polynesia, March-May, 2002 (NODC Accession 0039738)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data are coral species and occurrences data from Pacific reef areas (crest, flat, and slope) collected at sites in Manado, northern Sulawesi, Indonesia (app....

  18. Post-traumatic stress disorder and depression co-occurrence: Structural relations among disorder constructs and trait and symptom dimensions.

    Science.gov (United States)

    Post, Loren M; Feeny, Norah C; Zoellner, Lori A; Connell, Arin M

    2016-12-01

    Post-traumatic stress disorder (PTSD) and major depressive disorder (MDD) in response to trauma co-occur at high rates. A better understanding of the nature of this co-occurrence is critical to developing an accurate conceptualization of the disorders. This study examined structural relations among the PTSD and MDD constructs and trait and symptom dimensions within the framework of the integrative hierarchical model of anxiety and depression. Study participants completed clinician-rated and self-report measures during a pre-treatment assessment. The sample consisted of 200 treatment-seeking individuals with a primary DSM-IV PTSD diagnosis. Structural equation modelling was used to examine the relationship between the constructs. The trait negative affect/neuroticism construct had a direct effect on both PTSD and MDD. The trait positive affect/extraversion construct had a unique, negative direct effect on MDD, and PTSD had a unique, direct effect on the physical concerns symptoms construct. An alternative model with the PTSD and MDD constructs combined into an overall general traumatic stress construct produced a decrement in model fit. These findings provide a clearer understanding of the relationship between co-occurring PTSD and MDD as disorders with shared trait negative affect/neuroticism contributing to the overlap between them and unique trait positive affect/extraversion and physical concerns differentiating them. Therefore, PTSD and MDD in response to trauma may be best represented as two distinct, yet strongly related constructs. In assessing individuals who have been exposed to trauma, practitioners should recognize that co-occurring PTSD and MDD appears to be best represented as two distinct, yet strongly related constructs. Negative affect may be the shared vulnerability directly influencing both PTSD and MDD; however, in the presence of both PTSD and MDD, low positive affect appears to be more specifically related to MDD and fear of physical

  19. Exploiting link structure for web page genre identification

    KAUST Repository

    Zhu, Jia; Xie, Qing; Yu, Shoou I.; Wong, Wai Hung

    2015-01-01

    As the World Wide Web develops at an unprecedented pace, identifying web page genre has recently attracted increasing attention because of its importance in web search. A common approach for identifying genre is to use textual features that can be extracted directly from a web page, that is, On-Page features. The extracted features are subsequently inputted into a machine learning algorithm that will perform classification. However, these approaches may be ineffective when the web page contains limited textual information (e.g., the page is full of images). In this study, we address genre identification of web pages under the aforementioned situation. We propose a framework that uses On-Page features while simultaneously considering information in neighboring pages, that is, the pages that are connected to the original page by backward and forward links. We first introduce a graph-based model called GenreSim, which selects an appropriate set of neighboring pages. We then construct a multiple classifier combination module that utilizes information from the selected neighboring pages and On-Page features to improve performance in genre identification. Experiments are conducted on well-known corpora, and favorable results indicate that our proposed framework is effective, particularly in identifying web pages with limited textual information. © 2015 The Author(s)

  20. Exploiting link structure for web page genre identification

    KAUST Repository

    Zhu, Jia

    2015-07-07

    As the World Wide Web develops at an unprecedented pace, identifying web page genre has recently attracted increasing attention because of its importance in web search. A common approach for identifying genre is to use textual features that can be extracted directly from a web page, that is, On-Page features. The extracted features are subsequently inputted into a machine learning algorithm that will perform classification. However, these approaches may be ineffective when the web page contains limited textual information (e.g., the page is full of images). In this study, we address genre identification of web pages under the aforementioned situation. We propose a framework that uses On-Page features while simultaneously considering information in neighboring pages, that is, the pages that are connected to the original page by backward and forward links. We first introduce a graph-based model called GenreSim, which selects an appropriate set of neighboring pages. We then construct a multiple classifier combination module that utilizes information from the selected neighboring pages and On-Page features to improve performance in genre identification. Experiments are conducted on well-known corpora, and favorable results indicate that our proposed framework is effective, particularly in identifying web pages with limited textual information. © 2015 The Author(s)

  1. Structural Damage Identification in Stiffened Plate Fatigue Specimens Using Piezoelectric Active Sensing

    Science.gov (United States)

    2011-09-01

    isolated AO mode first arrival, recorded at PZT 2, is shown at 3 different fatigue levels. Figure 5. The area under the PSD curve, calculated twice...Structural Damage Identification in Stiffened Plate Fatigue Specimens Using Piezoelectric Active Sensing B. L. GRISSO, G. PARK, L. W. SALVINO...with several challenges including limited performance knowledge of the materials, aluminum sensitization, structural fatigue performance, and

  2. Optimal Design of Experiments for Parametric Identification of Civil Engineering Structures

    OpenAIRE

    Kirkegaard, Poul Henning

    1991-01-01

    Optimal Systems of experiments for parametric identification of civil engineering structures is investigated. Design of experiments for parametric identification of dynamic systems is usually done by minimizing a scalar measure, e.g the determinant, the trace ect., of an estimated parameter covariance matrix, based on prior knowledge. The experimental conditions available for adjustment, considering in this thesis, are input signal, sampling rate, the location of sensors and number of sensors.

  3. Identification of structural domains in proteins by a graph heuristic

    NARCIS (Netherlands)

    Wernisch, Lorenz; Hunting, M.M.G.; Wodak, Shoshana J.

    1999-01-01

    A novel automatic procedure for identifying domains from protein atomic coordinates is presented. The procedure, termed STRUDL (STRUctural Domain Limits), does not take into account information on secondary structures and handles any number of domains made up of contiguous or non-contiguous chain

  4. Structure Identification in High-Resolution Transmission Electron Microscopic Images

    DEFF Research Database (Denmark)

    Vestergaard, Jacob Schack; Kling, Jens; Dahl, Anders Bjorholm

    2014-01-01

    A connection between microscopic structure and macroscopic properties is expected for almost all material systems. High-resolution transmission electron microscopy is a technique offering insight into the atomic structure, but the analysis of large image series can be time consuming. The present ...

  5. Structural Identification and Comparison of Intelligent Mobile Learning Environment

    Science.gov (United States)

    Upadhyay, Nitin; Agarwal, Vishnu Prakash

    2007-01-01

    This paper proposes a methodology using graph theory, matrix algebra and permanent function to compare different architecture (structure) design of intelligent mobile learning environment. The current work deals with the development/selection of optimum architecture (structural) model of iMLE. This can be done using the criterion as discussed in…

  6. Development of Database Assisted Structure Identification (DASI Methods for Nontargeted Metabolomics

    Directory of Open Access Journals (Sweden)

    Lochana C. Menikarachchi

    2016-05-01

    Full Text Available Metabolite structure identification remains a significant challenge in nontargeted metabolomics research. One commonly used strategy relies on searching biochemical databases using exact mass. However, this approach fails when the database does not contain the unknown metabolite (i.e., for unknown-unknowns. For these cases, constrained structure generation with combinatorial structure generators provides a potential option. Here we evaluated structure generation constraints based on the specification of: (1 substructures required (i.e., seed structures; (2 substructures not allowed; and (3 filters to remove incorrect structures. Our approach (database assisted structure identification, DASI used predictive models in MolFind to find candidate structures with chemical and physical properties similar to the unknown. These candidates were then used for seed structure generation using eight different structure generation algorithms. One algorithm was able to generate correct seed structures for 21/39 test compounds. Eleven of these seed structures were large enough to constrain the combinatorial structure generator to fewer than 100,000 structures. In 35/39 cases, at least one algorithm was able to generate a correct seed structure. The DASI method has several limitations and will require further experimental validation and optimization. At present, it seems most useful for identifying the structure of unknown-unknowns with molecular weights <200 Da.

  7. Identification of subsurface structures using electromagnetic data and shape priors

    Energy Technology Data Exchange (ETDEWEB)

    Tveit, Svenn, E-mail: svenn.tveit@uni.no [Uni CIPR, Uni Research, Bergen 5020 (Norway); Department of Mathematics, University of Bergen, Bergen 5020 (Norway); Bakr, Shaaban A., E-mail: shaaban.bakr1@gmail.com [Department of Mathematics, Faculty of Science, Assiut University, Assiut 71516 (Egypt); Uni CIPR, Uni Research, Bergen 5020 (Norway); Lien, Martha, E-mail: martha.lien@octio.com [Uni CIPR, Uni Research, Bergen 5020 (Norway); Octio AS, Bøhmergaten 44, Bergen 5057 (Norway); Mannseth, Trond, E-mail: trond.mannseth@uni.no [Uni CIPR, Uni Research, Bergen 5020 (Norway); Department of Mathematics, University of Bergen, Bergen 5020 (Norway)

    2015-03-01

    We consider the inverse problem of identifying large-scale subsurface structures using the controlled source electromagnetic method. To identify structures in the subsurface where the contrast in electric conductivity can be small, regularization is needed to bias the solution towards preserving structural information. We propose to combine two approaches for regularization of the inverse problem. In the first approach we utilize a model-based, reduced, composite representation of the electric conductivity that is highly flexible, even for a moderate number of degrees of freedom. With a low number of parameters, the inverse problem is efficiently solved using a standard, second-order gradient-based optimization algorithm. Further regularization is obtained using structural prior information, available, e.g., from interpreted seismic data. The reduced conductivity representation is suitable for incorporation of structural prior information. Such prior information cannot, however, be accurately modeled with a gaussian distribution. To alleviate this, we incorporate the structural information using shape priors. The shape prior technique requires the choice of kernel function, which is application dependent. We argue for using the conditionally positive definite kernel which is shown to have computational advantages over the commonly applied gaussian kernel for our problem. Numerical experiments on various test cases show that the methodology is able to identify fairly complex subsurface electric conductivity distributions while preserving structural prior information during the inversion.

  8. Identification of structural relaxation in the dielectric response of water

    DEFF Research Database (Denmark)

    Hansen, Jesper Schmidt; Kisliuk, Alexander; Solokov, Alexei P.

    2016-01-01

    One century ago pioneering dielectric results obtained for water and n-alcohols triggered the advent of molecular rotation diffusion theory considered by Debye to describe the primary dielectric absorption in these liquids. Comparing dielectric, viscoelastic, and light scattering results, we...... unambiguously demonstrate that the structural relaxation appears only as a high-frequency shoulder in the dielectric spectra of water. In contrast, the main dielectric peak is related to a supramolecular structure, analogous to the Debye-like peak observed in monoalcohols....

  9. A Tensor-Based Structural Damage Identification and Severity Assessment

    Science.gov (United States)

    Anaissi, Ali; Makki Alamdari, Mehrisadat; Rakotoarivelo, Thierry; Khoa, Nguyen Lu Dang

    2018-01-01

    Early damage detection is critical for a large set of global ageing infrastructure. Structural Health Monitoring systems provide a sensor-based quantitative and objective approach to continuously monitor these structures, as opposed to traditional engineering visual inspection. Analysing these sensed data is one of the major Structural Health Monitoring (SHM) challenges. This paper presents a novel algorithm to detect and assess damage in structures such as bridges. This method applies tensor analysis for data fusion and feature extraction, and further uses one-class support vector machine on this feature to detect anomalies, i.e., structural damage. To evaluate this approach, we collected acceleration data from a sensor-based SHM system, which we deployed on a real bridge and on a laboratory specimen. The results show that our tensor method outperforms a state-of-the-art approach using the wavelet energy spectrum of the measured data. In the specimen case, our approach succeeded in detecting 92.5% of induced damage cases, as opposed to 61.1% for the wavelet-based approach. While our method was applied to bridges, its algorithm and computation can be used on other structures or sensor-data analysis problems, which involve large series of correlated data from multiple sensors. PMID:29301314

  10. Structural identification and damage diagnosis using self-sensing piezo-impedance transducers

    Science.gov (United States)

    Lim, Yee Yan; Bhalla, Suresh; Kiong Soh, Chee

    2006-08-01

    The use of smart materials, such as lead zirconate titanate (PZT), has accelerated developments in the fields of structural identification and automated structural health monitoring (SHM). One such technique that has made much progress is the electro-mechanical impedance (EMI) technique, which employs self-sensing piezo-impedance transducers. In this technique, a PZT patch is surface bonded to the structure to be monitored and its corresponding electro-mechanical admittance signature is used for damage detection. This paper introduces a new method for identifying structures from the measured admittance signatures in terms of equivalent structural parameters, whereby the identified parameters are used for damage characterization. The new method has been applied to a truss, a beam and a concrete cube, and found to be able to successfully perform structural identification and damage diagnosis. In addition, several advantages have been ascertained in comparison with the conventional, non-parametric statistical methods.

  11. Magnetic resonance imaging identification of muscular and ligamentous structures of the female pelvic floor

    International Nuclear Information System (INIS)

    Bezerra, Maria Rita Lima; Soares, Adriano Fleury F.; Faintuch, Salomao; Goldman, Suzan Menasce; Ajzen, Sergio A.; D'Ippolito, Giuseppe; Szejnfeld, Jacob; Girao, Manoel

    2001-01-01

    The objective was to determine the frequency and to assess the interobserver agreement of identification of muscular and ligamentous pelvic floor structures using magnetic resonance imaging. The method: twenty asymptomatic female volunteers (aged 20-80 years old; mean: 50) were submitted to magnetic resonance imaging (1.5 T) examinations of the pelvis. Turbo spin-echo sequences were employed to obtain T1 and T2 weighted images on axial and sagittal planes. Two independent observers evaluated the scans in order to identify the levator ani (coccygeal, pubococcygeal, iliococcygeal and puborectalis muscles), obturatorius internus and urethral sphincter muscles, and the pubovesical and pubourethral ligaments. The frequency and the interobserver agreement of the identification of the anatomical structures were assessed (kappa statistic - κ). The results: the frequency of identification of the structures ranged from 50 to 100%, and was slightly lower for identification of the ligaments. Interobserver agreement was as follows: levator ani and obturatorius internus muscle (κ=1), pubococcygeal (κ=0.62), iliococcygeal (κ=0.86), puborectalis (κ= 0.27), coccygeal (κ=0) and urethral sphincter muscles (κ=1), pubovesical (κ=0.50) and pubourethral (κ=0.58) ligaments. The conclusion: magnetic resonance imaging of the pelvis allowed precise identification of the main muscular and ligamentous pelvic floor structures in most individuals, whereas interobserver agreement was considered good. (author)

  12. Occurrence and identification of Ancylostomatidae in Maned-wolf ( Chrysocyon brachyurus, Illiger, 1811 from the Triângulo Mineiro area, Minas Gerais, Brazil

    Directory of Open Access Journals (Sweden)

    Maria José Santos Mundim

    1991-06-01

    Full Text Available An experiment involving nine Maned-wolf(Chrysocyon brachyurus, from the Triangulo Mineiro area,Minas Gerais, Brazil, was carried out to check the occurrence of hookworm eggs and their adult forms. Eggs of the referred helminths were identified in 77.77% of the studied animals. Among the adult forms founded in the small intestine, two species were identified: Uncinaria stenocephala (Railliet, 1884 and Ancylostoma caninum (Ercolani, 1859. The authors report of the first occurrence in the U. stenocephala and C.brachyurus Brazil.

  13. Occurrence, diversity and community structure of culturable atrazine degraders in industrial and agricultural soils exposed to the herbicide in Shandong Province, P.R. China

    OpenAIRE

    Bazhanov, Dmitry P.; Li, Chengyun; Li, Hongmei; Li, Jishun; Zhang, Xinjian; Chen, Xiangfeng; Yang, Hetong

    2016-01-01

    Background Soil populations of bacteria rapidly degrading atrazine are critical to the environmental fate of the herbicide. An enrichment bias from the routine isolation procedure prevents studying the diversity of atrazine degraders. In the present work, we analyzed the occurrence, diversity and community structure of soil atrazine-degrading bacteria based on their direct isolation. Methods Atrazine-degrading bacteria were isolated by direct plating on a specially developed SM agar. The atra...

  14. On Early Conflict Identification by Requirements Modeling of Energy System Control Structures

    DEFF Research Database (Denmark)

    Heussen, Kai; Gehrke, Oliver; Niemann, Hans Henrik

    2015-01-01

    issues early. For requirements formulation of control structures, cyber and physical aspects need to be jointly represented to express interdependencies, check for consistency and discover potentially conflicting requirements. Early identification of potential conflicts may prevent larger problems...... at later design stages. However, languages employed for requirements modeling today do not offer the expressiveness necessary to represent control purposes in relation to domain level interactions and therefore miss several types of interdependencies. This paper introduces the idea of control structure...... modeling for early requirements checking using a suitable modeling language, and illustrates how this approach enables the identification of several classes of controller conflict....

  15. Modal identification of composite structures using Eigen realization method

    International Nuclear Information System (INIS)

    Hamidzadeh, H.R.; Afolabi, D.

    1996-01-01

    Experimental modal analysis has proved to be a useful tool to determine the vibration response of complex composite structures. An accurate method for extracting modal parameters of these type of structures are presented. The method used experimental impulse response of the system as input and provides natural frequencies and damping ratios of a dynamic system. The employed theories are Eigen Realization and Impulse Response methods. The adopted method is superior to other available methods in time and frequency domains. The presented method is proven to provide robustness with respect to measured noise

  16. Improvement in Protein Domain Identification Is Reached by Breaking Consensus, with the Agreement of Many Profiles and Domain Co-occurrence.

    Directory of Open Access Journals (Sweden)

    Juliana Bernardes

    2016-07-01

    Full Text Available Traditional protein annotation methods describe known domains with probabilistic models representing consensus among homologous domain sequences. However, when relevant signals become too weak to be identified by a global consensus, attempts for annotation fail. Here we address the fundamental question of domain identification for highly divergent proteins. By using high performance computing, we demonstrate that the limits of state-of-the-art annotation methods can be bypassed. We design a new strategy based on the observation that many structural and functional protein constraints are not globally conserved through all species but might be locally conserved in separate clades. We propose a novel exploitation of the large amount of data available: 1. for each known protein domain, several probabilistic clade-centered models are constructed from a large and differentiated panel of homologous sequences, 2. a decision-making protocol combines outcomes obtained from multiple models, 3. a multi-criteria optimization algorithm finds the most likely protein architecture. The method is evaluated for domain and architecture prediction over several datasets and statistical testing hypotheses. Its performance is compared against HMMScan and HHblits, two widely used search methods based on sequence-profile and profile-profile comparison. Due to their closeness to actual protein sequences, clade-centered models are shown to be more specific and functionally predictive than the broadly used consensus models. Based on them, we improved annotation of Plasmodium falciparum protein sequences on a scale not previously possible. We successfully predict at least one domain for 72% of P. falciparum proteins against 63% achieved previously, corresponding to 30% of improvement over the total number of Pfam domain predictions on the whole genome. The method is applicable to any genome and opens new avenues to tackle evolutionary questions such as the reconstruction of

  17. Nonlinear system identification of smart structures under high impact loads

    Science.gov (United States)

    Sarp Arsava, Kemal; Kim, Yeesock; El-Korchi, Tahar; Park, Hyo Seon

    2013-05-01

    The main purpose of this paper is to develop numerical models for the prediction and analysis of the highly nonlinear behavior of integrated structure control systems subjected to high impact loading. A time-delayed adaptive neuro-fuzzy inference system (TANFIS) is proposed for modeling of the complex nonlinear behavior of smart structures equipped with magnetorheological (MR) dampers under high impact forces. Experimental studies are performed to generate sets of input and output data for training and validation of the TANFIS models. The high impact load and current signals are used as the input disturbance and control signals while the displacement and acceleration responses from the structure-MR damper system are used as the output signals. The benchmark adaptive neuro-fuzzy inference system (ANFIS) is used as a baseline. Comparisons of the trained TANFIS models with experimental results demonstrate that the TANFIS modeling framework is an effective way to capture nonlinear behavior of integrated structure-MR damper systems under high impact loading. In addition, the performance of the TANFIS model is much better than that of ANFIS in both the training and the validation processes.

  18. Flexibility-based structural damage identification using Gauss ...

    Indian Academy of Sciences (India)

    ... structural damages in civil infrastructure, such as high-rise buildings, long-span ... tion is widely used in bridges and buildings today because it is easy and ..... The objective of this paper is to design a mathematical algo- ..... Single damage.

  19. Structural Identification of Lentinus edodes Cellulose Derivative that ...

    African Journals Online (AJOL)

    ... aspartic acid, leucine and alanine. Conclusion: CED was identified as a complex of peptide and polysaccharide structures possessing β- (1, 4)-glucan backbones, and it provides a theoretical basis for developing polysaccharide preparations to control aflatoxin contamination with medical and food science applications.

  20. Identification of material properties of sandwich structure with piezoelectric patches

    Directory of Open Access Journals (Sweden)

    Zemčík R.

    2008-11-01

    Full Text Available The work focuses on light-weight sandwich structures made of carbon-epoxy skins and foam core which have unique bending stiffness compared to conventional materials. The skins are manufactured by vacuum autoclave technology from unidirectional prepregs and the sandwich is then glued together. The resulting material properties of the structure usually differ from those provided by manufacturer or even those obtained from experimental tests on separate materials, which makes computational models unreliable. Therefore, the properties are identified using the combination of experimental analysis of the sandwich with attached piezoelectric transducer and corresponding static and modal finite element analyses. Simple mathematical optimization with repetitive finite element solution is used. The model is then verified by transient analysis when the piezoelectric patch is excited by harmonic signals covering the first two eigen-frequencies and the induced oscillations are measured by laser sensor.

  1. Automated, parallel mass spectrometry imaging and structural identification of lipids

    DEFF Research Database (Denmark)

    Ellis, Shane R.; Paine, Martin R.L.; Eijkel, Gert B.

    2018-01-01

    We report a method that enables automated data-dependent acquisition of lipid tandem mass spectrometry data in parallel with a high-resolution mass spectrometry imaging experiment. The method does not increase the total image acquisition time and is combined with automatic structural assignments....... This lipidome-per-pixel approach automatically identified and validated 104 unique molecular lipids and their spatial locations from rat cerebellar tissue....

  2. Structural Style and Lead Identification, Northern Depobelt, Niger Delta, Nigeria

    International Nuclear Information System (INIS)

    Ola, P. S.; Adekoya, J. A.

    2003-01-01

    By interpreting biofacies data, wire line log and grid of 2D seismic sections in an integrated manner in some portions of the northern depobelt, Niger delta, the sequence stratigraphic framework of the area was established. This enabled the structural style and genetic sequences of the area to be inferred. Results showed that the depobelt could be I subdivided into minibasins that trend in a NW SE direction and are bounded by synthetic faults in the proximal end and shale diapers in the distal end. All the exploration wells in the area of study, which were drilled on structural highs and were very close to the synthetic faults, turned out to be dry whereas the synclinal lows that resulted from local deposition of sands of the first genetic sequences in each of the minibasins could contain hydrocarbon. Such areas of synclinal lows are hereby proposed, as lead in this study. The intervals are untested and occur faraway from existing wells. By projection the geochemical data of well Oben-1 in the area suggest that the intervals fall within the oil generative window. Characteristic seismic reflection termination patterns, which are predominantly down laps and on laps suggest existence of structural closure for hydrocarbon accumulation within the synclinal lows. This study therefore recommends a reappraisal of these leads using a more focused 3D seismic study. The northern delta depobelt is less risky and inexpensive for oil exploration and exploitation compared with the offshore Niger delta that is gaining more prominence

  3. Structural damage identification based on laser ultrasonic propagation imaging technology

    Science.gov (United States)

    Chia, Chen-Ciang; Jang, Si-Gwang; Lee, Jung-Ryul; Yoon, Dong-Jin

    2009-06-01

    An ultrasonic propagation imaging (UPI) system consisted of a Q-switched Nd-YAG pulsed laser and a galvanometer laser mirror scanner was developed. The system which requires neither reference data nor fixed focal length could be used for health monitoring of curved structures. If combined with a fiber acoustic wave PZT (FAWPZT) sensor, it could be used to inspect hot target structures that present formidable challenges to the usage of contact piezoelectric transducers mainly due to the operating temperature limitation of transducers and debonding problem due to the mismatch of coefficient of thermal expansion between the target, transducer and bonding material. The inspection of a stainless steel plate with a curvature radius of about 4 m, having 2mm×1mm open-crack was demonstrated at 150°C using a FAWPZT sensor welded on the plate. Highly-curved surfaces scanning capability and adaptivity of the system for large laser incident angle up to 70° was demonstrated on a stainless steel cylinder with 2mm×1mm open-crack. The imaging results were presented in ultrasonic propagation movie which was a moving wavefield emerged from an installed ultrasonic sensor. Damages were localized by the scattering wavefields. The result images enabled easy detection and interpretation of structural defects as anomalies during ultrasonic wave propagation.

  4. A study on identification of nonlinear structure by experimental modal analysis

    International Nuclear Information System (INIS)

    Sone, Akira; Suzuki, Kohei; Nakamura, Hajime.

    1990-01-01

    In this paper, identification techniques based on the experimental modal analysis for the equivalent modal parameters of nonlinear structures are examined from a practical viewpoint. First, using a simple cantilever model with gap or friction at the supported end, the gain characteristics of transfer function are evaluated through the sinusoidal sweep test and random wave test. Second, the equivalent modal parameters such as natural frequency and damping ratio are estimated by two types of identification techniques: ARMA (autoregressive/moving average) model fitting and curve fitting with iterative calculations. From the comparison of the response of the model obtained by the random excitation test and numerical calculation using the equivalent modal parameters, it has been clarified that the ARMA model fitting can be applied to linearized modal parameter identification for nonlinear structures. (author)

  5. Identification of inks and structural characterization of contemporary artistic prints by laser-induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    Oujja, M.; Vila, A.; Rebollar, E.; Garcia, J.F.; Castillejo, M.

    2005-01-01

    Identification of the inks used in artistic prints and the order in which different ink layers have been applied on a paper substrate are important factors to complement the classical stylistic aspects for the authentication of this type of objects. Laser-induced breakdown spectroscopy (LIBS) is investigated to determine the chemical composition and structural distribution of the constituent materials of model prints made by applying one or two layers of several blue and black inks on an Arches paper substrate. By using suitable laser excitation conditions, identification of the inks was possible by virtue of emissions from key elements present in their composition. Analysis of successive spectra on the same spot allowed the identification of the order in which the inks were applied on the paper. The results show the potential of laser-induced breakdown spectroscopy for the chemical and structural characterization of artistic prints

  6. Arctic boundary layer properties and its influence on cloud occurrence frequency, phase and structure in autumn season

    Science.gov (United States)

    Qiu, S.; Dong, X.; Xi, B.

    2017-12-01

    In this study, autumnal boundary layer characteristics and cloud properties have been investigated using data collected at the Atmospheric Radiation Measurement North Slope of Alaska (ARM NSA) site from January 2002 to December 2008. We found that both cloud and planetary boundary layer (PBL) properties can be well distinguished by surface wind directions. When the ARM NSA site is dominated by a northerly wind during the period September- November, the PBL is at near saturation for all three months; while the maximum RH layer varies from low and thin in September, to higher and thicker in October, and then it becomes close to surface again in November. Both the ceilometer and the MPL derived cloud base heights coincide well with the RH maximum layer in the PBL for all three autumnal months. The frequencies of occurrence of mixed phase clouds in September and October are around 60-80% under a northerly wind, which are about 1.5 times higher than those during a southerly wind. Under northerly wind, the PDFs of PBL temperature and specific humidity are narrow and unimodal, with a peak probability around 0.4-0.5. Under a southerly wind, on the other hand, the PBL is both warmer and wetter than northerly wind profiles, which result in lower RH values (10-15% lower) in September and October; and the PDFs of PBL temperature and specific humidity are more evenly distributed with larger distribution range and lower PDF peak values (<0.3). In September, colder and dryer PBL is more favorable for mixed phase cloud formation, cloud occurrence frequency decreases from 90% to 60% as PBL temperature and specific humidity increase. In October, the frequency of occurrence of mixed phase clouds also decreases from 90% to 50-60% as PBL temperature increases. While in November, it increases first and then decreases with increasing PBL temperature and specific humidity. The frequency of occurrence of mixed phase clouds is linearly correlated to PBL RH values: for all three months, it

  7. Acceptors in cadmium telluride. Identification and electronic structure

    International Nuclear Information System (INIS)

    Molva, E.

    1983-11-01

    It is shown that electronic properties of CdTe are determined by impurities more than by intrinsic defects like vacancies or interstitials in Cd or Te contrary to classical theories. These results are based on annealing, diffusion, implantation and electron irradiation at 4 K. Centers appearing in treated samples are accurately identified by photoluminescence, cathodoluminescence infra-red absorption, electrical measurements and magneto-optic properties. Acceptors identified are Li, Na, Cu, Ag and Au impurities in Cd and N, P and As in Te. Energy levels of all acceptors and fine structure of excitons are determined [fr

  8. Nonlinear system identification of smart structures under high impact loads

    International Nuclear Information System (INIS)

    Sarp Arsava, Kemal; Kim, Yeesock; El-Korchi, Tahar; Park, Hyo Seon

    2013-01-01

    The main purpose of this paper is to develop numerical models for the prediction and analysis of the highly nonlinear behavior of integrated structure control systems subjected to high impact loading. A time-delayed adaptive neuro-fuzzy inference system (TANFIS) is proposed for modeling of the complex nonlinear behavior of smart structures equipped with magnetorheological (MR) dampers under high impact forces. Experimental studies are performed to generate sets of input and output data for training and validation of the TANFIS models. The high impact load and current signals are used as the input disturbance and control signals while the displacement and acceleration responses from the structure–MR damper system are used as the output signals. The benchmark adaptive neuro-fuzzy inference system (ANFIS) is used as a baseline. Comparisons of the trained TANFIS models with experimental results demonstrate that the TANFIS modeling framework is an effective way to capture nonlinear behavior of integrated structure–MR damper systems under high impact loading. In addition, the performance of the TANFIS model is much better than that of ANFIS in both the training and the validation processes. (paper)

  9. Hierarchically structured identification and classification method for vibrational monitoring of reactor components

    International Nuclear Information System (INIS)

    Saedtler, E.

    1981-01-01

    The dissertation discusses: 1. Approximative filter algorithms for identification of systems and hierarchical structures. 2. Adaptive statistical pattern recognition and classification. 3. Parameter selection, extraction, and modelling for an automatic control system. 4. Design of a decision tree and an adaptive diagnostic system. (orig./RW) [de

  10. Vibro-Acoustic modulation based damage identification in a composite skin-stiffener structure

    NARCIS (Netherlands)

    Ooijevaar, T.H.; Loendersloot, Richard; Rogge, M.D.; Akkerman, Remko; Tinga, Tiedo; Le Cam, V.; Mevel, L.; Schoefs, F.

    2014-01-01

    The vibro-acoustic modulation method is applied to a composite skin-stiffener structure to investigate the possibilities to utilise this method for damage identification in terms of detection, localisation and damage quantification. The research comprises a theoretical part and an experimental part.

  11. Vibro-acoustic modulation–based damage identification in a composite skin–stiffener structure

    NARCIS (Netherlands)

    Ooijevaar, T.H.; Rogge, M.D.; Loendersloot, Richard; Warnet, Laurent; Akkerman, Remko; Tinga, Tiedo

    2016-01-01

    Vibro-acoustic modulation–based damage identification relies on the modulation of a high-frequency carrier signal by an intenser low-frequency vibration signal due to damage-induced structural nonlinearities. A time domain analysis of the vibro-acoustic modulation phenomena was presented at multiple

  12. On the Uncertainty of Identification of Civil Engineering Structures using ARMA Models

    DEFF Research Database (Denmark)

    Andersen, P.; Brincker, Rune; Kirkegaard, Poul Henning

    In this paper the uncertainties of modal parameters estimated using ARMA models for identification of civil engineering structures are investigated. How to initialize the predictor part of a Gauss-Newton optimization algorithm is put in focus. A backward-forecasting procedure for initialization...

  13. Identification of Time Varying Civil Engineering Structures using Multivariate Recursive Time Domain Models

    DEFF Research Database (Denmark)

    Andersen, P.; Skjærbæk, P. S.; Kirkegaard, Poul Henning

    with the smoothed quanties which have been obtained from SARCOF. The results show the usefulness of the technique for identification of a time varying civil engineering structure. It is found that all the techniques give reliable estiates of the frequencies of the two lowest modes and the first mode shape. Only...

  14. On the Uncertainty of Identification of Civil Engineering Structures Using ARMA Models

    DEFF Research Database (Denmark)

    Andersen, Palle; Brincker, Rune; Kirkegaard, Poul Henning

    1995-01-01

    In this paper the uncertainties of modal parameters estimated using ARMA models for identification of civil engineering structures are investigated. How to initialize the predictor part of a Gauss-Newton optimization algorithm is put in focus. A backward-forecasting procedure for initialization...

  15. Source Identification in Structural Acoustics with an Inverse Frequency Response Function Technique

    NARCIS (Netherlands)

    Visser, Rene

    2002-01-01

    Inverse source identification based on acoustic measurements is essential for the investigation and understanding of sound fields generated by structural vibrations of various devices and machinery. Acoustic pressure measurements performed on a grid in the nearfield of a surface can be used to

  16. Identification and determination of solitary wave structures in nonlinear wave propagation

    International Nuclear Information System (INIS)

    Newman, W.I.; Campbell, D.K.; Hyman, J.M.

    1991-01-01

    Nonlinear wave phenomena are characterized by the appearance of ''solitary wave coherent structures'' traveling at speeds determined by their amplitudes and morphologies. Assuming that these structures are briefly noninteracting, we propose a method for the identification of the number of independent features and their respective speeds. Using data generated from an exact two-soliton solution to the Korteweg-de-Vries equation, we test the method and discuss its strengths and limitations. 41 refs., 2 figs

  17. Identification of neural structures involved in stuttering using vibrotactile feedback.

    Science.gov (United States)

    Cheadle, Oliver; Sorger, Clarissa; Howell, Peter

    Feedback delivered over auditory and vibratory afferent pathways has different effects on the fluency of people who stutter (PWS). These features were exploited to investigate the neural structures involved in stuttering. The speech signal vibrated locations on the body (vibrotactile feedback, VTF). Eleven PWS read passages under VTF and control (no-VTF) conditions. All combinations of vibration amplitude, synchronous or delayed VTF and vibrator position (hand, sternum or forehead) were presented. Control conditions were performed at the beginning, middle and end of test sessions. Stuttering rate, but not speaking rate, differed between the control and VTF conditions. Notably, speaking rate did not change between when VTF was delayed versus when it was synchronous in contrast with what happens with auditory feedback. This showed that cerebellar mechanisms, which are affected when auditory feedback is delayed, were not implicated in the fluency-enhancing effects of VTF, suggesting that there is a second fluency-enhancing mechanism. Copyright © 2018 Elsevier Inc. All rights reserved.

  18. Damping characteristic identification of non-linear soil-structural system interaction by phase resonance

    International Nuclear Information System (INIS)

    Poterasu, V.F.

    1984-01-01

    It is presented a method and the phase resonance for damping characteristic identification of non-linear soil-structural interaction. The algorithm can be applied in case of any, not necessarily, damping characteristic of the system examined. For the identification, the system is harmonically excited and are considered the super-harmonic amplitudes for odd and even powers of the x. The response of shear beam system for different levels of base excitation and for different locations of the load is considered. (Author) [pt

  19. A model structure for identification of linear models of the UH-60 helicopter in hover and forward flight

    Science.gov (United States)

    1995-08-01

    A linear model structure applicable to identification of the UH-60 flight : dynamics in hover and forward flight without rotor-state data is developed. The : structure of the model is determined through consideration of the important : dynamic modes ...

  20. Identification of Clearance and Contact Stiffness in a Simplified Barrel-Cradle Structure of Artillery System

    Directory of Open Access Journals (Sweden)

    Bing Li

    2015-02-01

    Full Text Available In gun barrel-cradle structure, the presence of clearance usually changes the dynamic response of muzzle and results in shooting dispersion (under continuous firing condition. The parameter estimation of such clearance nonlinear system is the prerequisite for establishing quantitative relation between the clearance and muzzle disturbance. In this paper, the restoring force surface (RFS method and the nonlinear identification through feedback of outputs (NIFO method are first combined for parameter identification in a simplified barrel-cradle structure. With the RFS method, clearance value can be obtained by analyzing the restoring force plot. Then the contact stiffness can be identified by using NIFO method. This identification process is verified in a single-degree-of-freedom (SDOF system with clearance. To adapt to the rigid-flexible coupled beam system with clearances which is simplified from the barrel-cradle structure, a modification for the combined method mentioned above is proposed. The core idea of the modification is reducing the continuous system to multiple-degree-of-freedom (MDOF system to reserve the nonlinear characteristics through modal transformation matrix. The advantage of this transformation is that the linear parts of the MDOF systems are decoupled, which greatly reduces the difficulty of identification. The simulation results have shown the effectiveness of current method.

  1. Structural damage diagnosis based on on-line recursive stochastic subspace identification

    International Nuclear Information System (INIS)

    Loh, Chin-Hsiung; Weng, Jian-Huang; Liu, Yi-Cheng; Lin, Pei-Yang; Huang, Shieh-Kung

    2011-01-01

    This paper presents a recursive stochastic subspace identification (RSSI) technique for on-line and almost real-time structural damage diagnosis using output-only measurements. Through RSSI the time-varying natural frequencies of a system can be identified. To reduce the computation time in conducting LQ decomposition in RSSI, the Givens rotation as well as the matrix operation appending a new data set are derived. The relationship between the size of the Hankel matrix and the data length in each shifting moving window is examined so as to extract the time-varying features of the system without loss of generality and to establish on-line and almost real-time system identification. The result from the RSSI technique can also be applied to structural damage diagnosis. Off-line data-driven stochastic subspace identification was used first to establish the system matrix from the measurements of an undamaged (reference) case. Then the RSSI technique incorporating a Kalman estimator is used to extract the dynamic characteristics of the system through continuous monitoring data. The predicted residual error is defined as a damage feature and through the outlier statistics provides an indicator of damage. Verification of the proposed identification algorithm by using the bridge scouring test data and white noise response data of a reinforced concrete frame structure is conducted

  2. Secure fingerprint identification based on structural and microangiographic optical coherence tomography.

    Science.gov (United States)

    Liu, Xuan; Zaki, Farzana; Wang, Yahui; Huang, Qiongdan; Mei, Xin; Wang, Jiangjun

    2017-03-10

    Optical coherence tomography (OCT) allows noncontact acquisition of fingerprints and hence is a highly promising technology in the field of biometrics. OCT can be used to acquire both structural and microangiographic images of fingerprints. Microangiographic OCT derives its contrast from the blood flow in the vasculature of viable skin tissue, and microangiographic fingerprint imaging is inherently immune to fake fingerprint attack. Therefore, dual-modality (structural and microangiographic) OCT imaging of fingerprints will enable more secure acquisition of biometric data, which has not been investigated before. Our study on fingerprint identification based on structural and microangiographic OCT imaging is, we believe, highly innovative. In this study, we performed OCT imaging study for fingerprint acquisition, and demonstrated the capability of dual-modality OCT imaging for the identification of fake fingerprints.

  3. A structured patient identification model for medication therapy management services in a community pharmacy.

    Science.gov (United States)

    Pagano, Gina M; Groves, Brigid K; Kuhn, Catherine H; Porter, Kyle; Mehta, Bella H

    To describe the development and implementation of a structured patient identification model for medication therapy management (MTM) services within traditional dispensing activities of a community pharmacy to facilitate pharmacist-provided completion of MTM services. A daily clinical opportunity report was developed as a structured model to identify MTM opportunities daily for all MTM-eligible patients expecting to pick up a prescription. Pharmacy staff was trained and the standardized model was implemented at study sites. One hundred nineteen grocery store-based community pharmacies throughout Ohio, West Virginia, and Michigan. A structured patient identification model in a community pharmacy consists of reviewing a clinical opportunity report, identifying interventions for MTM-eligible patients, and possibly collaborating with an interdisciplinary team. This model allows pharmacists to increase MTM cases performed by providing a structured process for identifying MTM-eligible patients and completing MTM services. The development and implementation of a structured patient identification model in the community pharmacy was completed and consists of pharmacists reviewing a clinical opportunity report to identify MTM opportunities and perform clinical interventions for patients. In a 3-month pre- and post-implementation comparison, there was a 49% increase in the number of MTM services provided by pharmacists (P < 0.001). A structured patient identification model in the community pharmacy was associated with an increase in the amount of MTM services provided by pharmacists. This method could be a useful tool at a variety of community pharmacies to solve challenges associated with MTM completion. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  4. Uncertainty calculation for modal parameters used with stochastic subspace identification: an application to a bridge structure

    Science.gov (United States)

    Hsu, Wei-Ting; Loh, Chin-Hsiung; Chao, Shu-Hsien

    2015-03-01

    Stochastic subspace identification method (SSI) has been proven to be an efficient algorithm for the identification of liner-time-invariant system using multivariate measurements. Generally, the estimated modal parameters through SSI may be afflicted with statistical uncertainty, e.g. undefined measurement noises, non-stationary excitation, finite number of data samples etc. Therefore, the identified results are subjected to variance errors. Accordingly, the concept of the stabilization diagram can help users to identify the correct model, i.e. through removing the spurious modes. Modal parameters are estimated at successive model orders where the physical modes of the system are extracted and separated from the spurious modes. Besides, an uncertainty computation scheme was derived for the calculation of uncertainty bounds for modal parameters at some given model order. The uncertainty bounds of damping ratios are particularly interesting, as the estimation of damping ratios are difficult to obtain. In this paper, an automated stochastic subspace identification algorithm is addressed. First, the identification of modal parameters through covariance-driven stochastic subspace identification from the output-only measurements is used for discussion. A systematic way of investigation on the criteria for the stabilization diagram is presented. Secondly, an automated algorithm of post-processing on stabilization diagram is demonstrated. Finally, the computation of uncertainty bounds for each mode with all model order in the stabilization diagram is utilized to determine system natural frequencies and damping ratios. Demonstration of this study on the system identification of a three-span steel bridge under operation condition is presented. It is shown that the proposed new operation procedure for the automated covariance-driven stochastic subspace identification can enhance the robustness and reliability in structural health monitoring.

  5. A review of output-only structural mode identification literature employing blind source separation methods

    Science.gov (United States)

    Sadhu, A.; Narasimhan, S.; Antoni, J.

    2017-09-01

    Output-only modal identification has seen significant activity in recent years, especially in large-scale structures where controlled input force generation is often difficult to achieve. This has led to the development of new system identification methods which do not require controlled input. They often work satisfactorily if they satisfy some general assumptions - not overly restrictive - regarding the stochasticity of the input. Hundreds of papers covering a wide range of applications appear every year related to the extraction of modal properties from output measurement data in more than two dozen mechanical, aerospace and civil engineering journals. In little more than a decade, concepts of blind source separation (BSS) from the field of acoustic signal processing have been adopted by several researchers and shown that they can be attractive tools to undertake output-only modal identification. Originally intended to separate distinct audio sources from a mixture of recordings, mathematical equivalence to problems in linear structural dynamics have since been firmly established. This has enabled many of the developments in the field of BSS to be modified and applied to output-only modal identification problems. This paper reviews over hundred articles related to the application of BSS and their variants to output-only modal identification. The main contribution of the paper is to present a literature review of the papers which have appeared on the subject. While a brief treatment of the basic ideas are presented where relevant, a comprehensive and critical explanation of their contents is not attempted. Specific issues related to output-only modal identification and the relative advantages and limitations of BSS methods both from theoretical and application standpoints are discussed. Gap areas requiring additional work are also summarized and the paper concludes with possible future trends in this area.

  6. Nucleos: a web server for the identification of nucleotide-binding sites in protein structures.

    Science.gov (United States)

    Parca, Luca; Ferré, Fabrizio; Ausiello, Gabriele; Helmer-Citterich, Manuela

    2013-07-01

    Nucleos is a web server for the identification of nucleotide-binding sites in protein structures. Nucleos compares the structure of a query protein against a set of known template 3D binding sites representing nucleotide modules, namely the nucleobase, carbohydrate and phosphate. Structural features, clustering and conservation are used to filter and score the predictions. The predicted nucleotide modules are then joined to build whole nucleotide-binding sites, which are ranked by their score. The server takes as input either the PDB code of the query protein structure or a user-submitted structure in PDB format. The output of Nucleos is composed of ranked lists of predicted nucleotide-binding sites divided by nucleotide type (e.g. ATP-like). For each ranked prediction, Nucleos provides detailed information about the score, the template structure and the structural match for each nucleotide module composing the nucleotide-binding site. The predictions on the query structure and the template-binding sites can be viewed directly on the web through a graphical applet. In 98% of the cases, the modules composing correct predictions belong to proteins with no homology relationship between each other, meaning that the identification of brand-new nucleotide-binding sites is possible using information from non-homologous proteins. Nucleos is available at http://nucleos.bio.uniroma2.it/nucleos/.

  7. Modal Identification of A Tested Steel Frame using Linear ARX Model Structure

    Directory of Open Access Journals (Sweden)

    Yavuz Kaya

    2009-07-01

    Full Text Available This study contains the identification of modal dynamic properties of a 3-story large-scale steel test frame structure through shaking table measurements. Shaking table test is carried out to estimate the modal properties of the test frame such as natural frequencies, damping ratios and mode shapes. Among many different model structures, ARX (Auto Recursive Exogenous model structure is used for modal identification of the frame structure system. The unknown parameters in the obtained ARX model structure are estimated by Least-Square method by minimizing the AIC criteria with the help of a program coded in advanced computing software MATLAB®. The adopted model structure is then tested out in time domain to verify the validity of the model with the selected model parameters. Then the modal characteristics of test frame and the story stiffness are estimated using the white noise shakings. An attempt is done to determine the change of modal characteristics and the story stiffness of test frame according to the velocity, which the test frame structure experienced during the shaking schedule and also during the input shaking of El Centro 1940 NS. Results shows that there is an increase in damping ratio and a decrease in both story stiffness and natural frequency for all modes when the damage forms at cementitious device and the test frame structure itself during the shaking schedule.

  8. Identification of the structure parameters using short-time non-stationary stochastic excitation

    Science.gov (United States)

    Jarczewska, Kamila; Koszela, Piotr; Śniady, PaweŁ; Korzec, Aleksandra

    2011-07-01

    In this paper, we propose an approach to the flexural stiffness or eigenvalue frequency identification of a linear structure using a non-stationary stochastic excitation process. The idea of the proposed approach lies within time domain input-output methods. The proposed method is based on transforming the dynamical problem into a static one by integrating the input and the output signals. The output signal is the structure reaction, i.e. structure displacements due to the short-time, irregular load of random type. The systems with single and multiple degrees of freedom, as well as continuous systems are considered.

  9. Comparative analysis of different weight matrices in subspace system identification for structural health monitoring

    Science.gov (United States)

    Shokravi, H.; Bakhary, NH

    2017-11-01

    Subspace System Identification (SSI) is considered as one of the most reliable tools for identification of system parameters. Performance of a SSI scheme is considerably affected by the structure of the associated identification algorithm. Weight matrix is a variable in SSI that is used to reduce the dimensionality of the state-space equation. Generally one of the weight matrices of Principle Component (PC), Unweighted Principle Component (UPC) and Canonical Variate Analysis (CVA) are used in the structure of a SSI algorithm. An increasing number of studies in the field of structural health monitoring are using SSI for damage identification. However, studies that evaluate the performance of the weight matrices particularly in association with accuracy, noise resistance, and time complexity properties are very limited. In this study, the accuracy, noise-robustness, and time-efficiency of the weight matrices are compared using different qualitative and quantitative metrics. Three evaluation metrics of pole analysis, fit values and elapsed time are used in the assessment process. A numerical model of a mass-spring-dashpot and operational data is used in this research paper. It is observed that the principal components obtained using PC algorithms are more robust against noise uncertainty and give more stable results for the pole distribution. Furthermore, higher estimation accuracy is achieved using UPC algorithm. CVA had the worst performance for pole analysis and time efficiency analysis. The superior performance of the UPC algorithm in the elapsed time is attributed to using unit weight matrices. The obtained results demonstrated that the process of reducing dimensionality in CVA and PC has not enhanced the time efficiency but yield an improved modal identification in PC.

  10. Blind identification of the Millikan Library from earthquake data considering soil–structure interaction

    Science.gov (United States)

    Ghahari, S. F.; Abazarsa, F.; Avci, O.; Çelebi, Mehmet; Taciroglu, E.

    2016-01-01

    The Robert A. Millikan Library is a reinforced concrete building with a basement level and nine stories above the ground. Located on the campus of California Institute of Technology (Caltech) in Pasadena California, it is among the most densely instrumented buildings in the U.S. From the early dates of its construction, it has been the subject of many investigations, especially regarding soil–structure interaction effects. It is well accepted that the structure is significantly interacting with the surrounding soil, which implies that the true foundation input motions cannot be directly recorded during earthquakes because of inertial effects. Based on this limitation, input–output modal identification methods are not applicable to this soil–structure system. On the other hand, conventional output-only methods are typically based on the unknown input signals to be stationary whitenoise, which is not the case for earthquake excitations. Through the use of recently developed blind identification (i.e. output-only) methods, it has become possible to extract such information from only the response signals because of earthquake excitations. In the present study, we employ such a blind identification method to extract the modal properties of the Millikan Library. We present some modes that have not been identified from force vibration tests in several studies to date. Then, to quantify the contribution of soil–structure interaction effects, we first create a detailed Finite Element (FE) model using available information about the superstructure; and subsequently update the soil–foundation system's dynamic stiffnesses at each mode such that the modal properties of the entire soil–structure system agree well with those obtained via output-only modal identification.

  11. The Occurrence of Heamoproteuscolumbae in Pigeons ...

    African Journals Online (AJOL)

    The Occurrence of Heamoproteuscolumbae in Pigeons ( Columbidaelivia ) Based on Microscopy and PCR Based Method Analysis and Identification of New Lineage in the MalAvi Data Base in Kano State, Nigeria.

  12. Structural identification of short/middle span bridges by rapid impact testing: theory and verification

    International Nuclear Information System (INIS)

    Zhang, Jian; Wu, Z S; Zhang, Q Q; Guo, S L; Xu, D W

    2015-01-01

    A structural strain flexibility identification method by processing the multiple-reference impact testing data is proposed. First, a kind of novel long-gauge fiber optic sensor is developed for structural macro-strain monitoring. Second, the multiple-reference impact testing technology is employed, during which both the impacting force and structural strain responses are measured. The impact testing technology has unique merit because it is able to extract exact structural frequency response functions (FRFs), while other test methods, for instance ambient tests, can only output the FRFs with scaled magnitudes. Most importantly, the originality of the article is that a method of identifying the structural strain flexibility characteristic from the impact test data has been proposed, which is useful for structural static strain prediction and capacity evaluation. Examples of a six meter simple supported beam and a multiple-span continuous beam bridge have successfully verified the effectiveness of the proposed method. (paper)

  13. Structural identification of short/middle span bridges by rapid impact testing: theory and verification

    Science.gov (United States)

    Zhang, Jian; Zhang, Q. Q.; Guo, S. L.; Xu, D. W.; Wu, Z. S.

    2015-06-01

    A structural strain flexibility identification method by processing the multiple-reference impact testing data is proposed. First, a kind of novel long-gauge fiber optic sensor is developed for structural macro-strain monitoring. Second, the multiple-reference impact testing technology is employed, during which both the impacting force and structural strain responses are measured. The impact testing technology has unique merit because it is able to extract exact structural frequency response functions (FRFs), while other test methods, for instance ambient tests, can only output the FRFs with scaled magnitudes. Most importantly, the originality of the article is that a method of identifying the structural strain flexibility characteristic from the impact test data has been proposed, which is useful for structural static strain prediction and capacity evaluation. Examples of a six meter simple supported beam and a multiple-span continuous beam bridge have successfully verified the effectiveness of the proposed method.

  14. Sensor-Only System Identification for Structural Health Monitoring of Advanced Aircraft

    Science.gov (United States)

    Kukreja, Sunil L.; Bernstein, Dennis S.

    2012-01-01

    Environmental conditions, cyclic loading, and aging contribute to structural wear and degradation, and thus potentially catastrophic events. The challenge of health monitoring technology is to determine incipient changes accurately and efficiently. This project addresses this challenge by developing health monitoring techniques that depend only on sensor measurements. Since actively controlled excitation is not needed, sensor-to-sensor identification (S2SID) provides an in-flight diagnostic tool that exploits ambient excitation to provide advance warning of significant changes. S2SID can subsequently be followed up by ground testing to localize and quantify structural changes. The conceptual foundation of S2SID is the notion of a pseudo-transfer function, where one sensor is viewed as the pseudo-input and another is viewed as the pseudo-output, is approach is less restrictive than transmissibility identification and operational modal analysis since no assumption is made about the locations of the sensors relative to the excitation.

  15. Identification of Histamine H3 Receptor Ligands Using a New Crystal Structure Fragment-based Method

    DEFF Research Database (Denmark)

    Frandsen, Ida Osborn; Boesgaard, Michael W; Fidom, Kimberley

    2017-01-01

    Virtual screening offers an efficient alternative to high-throughput screening in the identification of pharmacological tools and lead compounds. Virtual screening is typically based on the matching of target structures or ligand pharmacophores to commercial or in-house compound catalogues....... The complete pharmacophore fragment library is freely available through the GPCR database, GPCRdb, allowing the successful application herein to be repeated for most of the 285 class A GPCR targets. The method could also easily be adapted to other protein families....

  16. Identification of damage in composite structures using Gaussian mixture model-processed Lamb waves

    Science.gov (United States)

    Wang, Qiang; Ma, Shuxian; Yue, Dong

    2018-04-01

    Composite materials have comprehensively better properties than traditional materials, and therefore have been more and more widely used, especially because of its higher strength-weight ratio. However, the damage of composite structures is usually varied and complicated. In order to ensure the security of these structures, it is necessary to monitor and distinguish the structural damage in a timely manner. Lamb wave-based structural health monitoring (SHM) has been proved to be effective in online structural damage detection and evaluation; furthermore, the characteristic parameters of the multi-mode Lamb wave varies in response to different types of damage in the composite material. This paper studies the damage identification approach for composite structures using the Lamb wave and the Gaussian mixture model (GMM). The algorithm and principle of the GMM, and the parameter estimation, is introduced. Multi-statistical characteristic parameters of the excited Lamb waves are extracted, and the parameter space with reduced dimensions is adopted by principal component analysis (PCA). The damage identification system using the GMM is then established through training. Experiments on a glass fiber-reinforced epoxy composite laminate plate are conducted to verify the feasibility of the proposed approach in terms of damage classification. The experimental results show that different types of damage can be identified according to the value of the likelihood function of the GMM.

  17. Relationships between structural social capital, knowledge identification capability and external knowledge acquisition

    Directory of Open Access Journals (Sweden)

    Beatriz Ortiz

    2017-07-01

    Full Text Available Purpose - The purpose of this paper is to analyze the mediating effect of the identification of valuable external knowledge on the relationship between the development of inter-organizational ties (structural social capital and the acquisition of external knowledge. Design/methodology/approach - Using a sample of 87 firms from Spanish biotechnology and pharmaceutics industries, the authors have tested the proposed mediation hypothesis by applying the partial least squares technique to a structural equations model. Findings - The study results show that those firms with stronger, more frequent and closer inter-relationships are able to increase the amount of intentionally acquired knowledge, partly due to the greater level of development of their knowledge identification capability. Thus, firms with a higher capability to recognize the value of the knowledge embedded in their inter-organizational networks will be more likely to design better strategies to acquire and integrate such knowledge into their current knowledge bases for either present or future use. Originality/value - This research contributes to knowledge management and social capital literature by means of the study of two key determinants of knowledge acquisition – structural social capital and knowledge identification capability – and the explanation of their relationships of mutual influence. The paper thus tries to fill this literature gap and connects the relational perspective of social capital with the knowledge-based view from a strategic point of view.

  18. Clinical identification of compensatory structures on projective tests: a self psychological approach.

    Science.gov (United States)

    Silverstein, M L

    2001-06-01

    In this article I discuss compensatory structure, a concept from Kohut's (1971, 1977) psychology of the self that is not as familiar as Kohut's other views about the self. Compensatory structures are attempts to repair selfobject failure, usually by strengthening idealization or twinship in the face of mirroring deficits. Compensatory structures, particularly their early indications, can be detected on projective tests for identifying adaptive resources and treatment potential. The clinical identification of compensatory structures on test findings is described using Rorschach and Thematic Apperception Test (Murray, 1943) content. Particular attention is devoted to the 2-part process of demonstrating first, an injury to the self, and second, how attempts to recover from such injuries can be detected on projective tests. Clinical examples are provided, and the differentiation between compensatory structures and defenses and sublimation is discussed.

  19. Structural impacts on the occurrence and effectiveness of transformational leadership : An empirical study at the organizational level of analysis

    NARCIS (Netherlands)

    Walter, Frank; Bruch, Heike

    2010-01-01

    This article empirically investigates the role of organizational structure in the transformational leadership (TFL) process. We examine organizational centralization, formalization, and size as antecedents of an organization's TFL climate, and as moderators of the relationship between TFL climate

  20. New Umami Amides: Structure-Taste Relationship Studies of Cinnamic Acid Derived Amides and the Natural Occurrence of an Intense Umami Amide in Zanthoxylum piperitum.

    Science.gov (United States)

    Frerot, Eric; Neirynck, Nathalie; Cayeux, Isabelle; Yuan, Yoyo Hui-Juan; Yuan, Yong-Ming

    2015-08-19

    A series of aromatic amides were synthesized from various acids and amines selected from naturally occurring structural frameworks. These synthetic amides were evaluated for umami taste in comparison with monosodium glutamate. The effect of the substitution pattern of both the acid and the amine parts on umami taste was investigated. The only intensely umami-tasting amides were those made from 3,4-dimethoxycinnamic acid. The amine part was more tolerant to structural changes. Amides bearing an alkyl- or alkoxy-substituted phenylethylamine residue displayed a clean umami taste as 20 ppm solutions in water. Ultraperformance liquid chromatography coupled with a high quadrupole-Orbitrap mass spectrometer (UPLC/MS) was subsequently used to show the natural occurrence of these amides. (E)-3-(3,4-Dimethoxyphenyl)-N-(4-methoxyphenethyl)acrylamide was shown to occur in the roots and stems of Zanthoxylum piperitum, a plant of the family Rutaceae growing in Korea, Japan, and China.

  1. Occurrences in Capital Structure Flow of Croatian Companies in the Pre-Recession Period (2002 – 2007

    Directory of Open Access Journals (Sweden)

    Stipan Penavin

    2010-12-01

    Full Text Available The objectives of the paper were to analyse the ways of changing the capital structure in Croatian companies in the period 2002-2007 and to examine whether there is a difference in the capital structure with regard to the activity and the regions in Croatia. The capital structure was examined by analysing three financial coefficients: debt ratio, liabilities/capital ratio and indebtedness factor. The research encompassed a representative sample of 1,500 Croatian companies whose structure was observed in the mentioned period. The companies had three activities: manufacturing, services and commerce and were located in three regions: eastern, north-western and the Adriatic region. Variance analysis (ANOVA for repeated measurements was used to analyse longitudinal data. The results show that the most frequent way of capital structure change is the one where the equity remains the same and own capital grows through retained earnings while the capital from outside sources increases as well. Furthermore, there is a difference in capital structure regarding the activity and the regions in Croatia at a certain time. The highest indebtedness was recorded in the commercial business while the lowest was in the service industry. Moreover, the highest indebtedness level is in the eastern region and the lowest in the north-western region.

  2. Whale Shark (Rhincodon typus) Seasonal Occurrence, Abundance and Demographic Structure in the Mid-Equatorial Atlantic Ocean.

    Science.gov (United States)

    Macena, Bruno C L; Hazin, Fábio H V

    2016-01-01

    Whale sharks are generally associated with environmental factors that drive their movements to specific locations where food availability is high. Consequently, foraging is believed to be the main reason for the formation of whale shark aggregations. Feeding aggregations occur mainly in nearshore areas and are composed primarily of immature individuals. Conversely, aggregations of mature adults are rarely observed, and their occurrence is correlated with oceanic environments. Despite an increase in the number of whale shark studies, information on mating and parturition grounds is still lacking. In the present work, we assessed the ecological and behavioural aspects of the whale sharks that visit the archipelago of São Pedro and São Paulo (ASPSP), located ~1,000 km off the coast of Brazil in the equatorial Atlantic Ocean. Forty-nine whale sharks were recorded from February 2005 to May 2014. The estimated mean ± SD size was 8.27 ± 2.52 m (range: 2.5-14.0 m) with no significant differences in size across the year. The maturational stages were classified by size as immature (9.0 m; 46.51%); with almost half of the observed animals being mature specimens. The majority of sightings occurred between February and June. During this period, the ocean current weakens and the waters are enriched by eggs and larvae of fishes and invertebrates that attract marine life to forage. At the same time, evidence of reproductive activity in adult females (i.e. swollen abdomen and bite marks on the pectoral fins), and the potential mating behaviour exhibited by one male, suggest that the ASPSP area might also have a role in whale shark reproduction. Irrespective of its use for feeding or reproduction, this insular habitat serves as a meeting point for both juvenile and adult whale sharks, and may play an important ecological role for the species.

  3. Radar-based quantitative precipitation estimation for the identification of debris flow occurrence over earthquake-affected regions in Sichuan, China

    Science.gov (United States)

    Shi, Zhao; Wei, Fangqiang; Chandrasekar, Venkatachalam

    2018-03-01

    Both Ms 8.0 Wenchuan earthquake on 12 May 2008 and Ms 7.0 Lushan earthquake on 20 April 2013 occurred in the province of Sichuan, China. In the earthquake-affected mountainous area, a large amount of loose material caused a high occurrence of debris flow during the rainy season. In order to evaluate the rainfall intensity-duration (I-D) threshold of the debris flow in the earthquake-affected area, and to fill up the observational gaps caused by the relatively scarce and low-altitude deployment of rain gauges in this area, raw data from two S-band China New Generation Doppler Weather Radar (CINRAD) were captured for six rainfall events that triggered 519 debris flows between 2012 and 2014. Due to the challenges of radar quantitative precipitation estimation (QPE) over mountainous areas, a series of improvement measures are considered: a hybrid scan mode, a vertical reflectivity profile (VPR) correction, a mosaic of reflectivity, a merged rainfall-reflectivity (R - Z) relationship for convective and stratiform rainfall, and rainfall bias adjustment with Kalman filter (KF). For validating rainfall accumulation over complex terrains, the study areas are divided into two kinds of regions by the height threshold of 1.5 km from the ground. Three kinds of radar rainfall estimates are compared with rain gauge measurements. It is observed that the normalized mean bias (NMB) is decreased by 39 % and the fitted linear ratio between radar and rain gauge observation reaches at 0.98. Furthermore, the radar-based I-D threshold derived by the frequentist method is I = 10.1D-0.52 and is underestimated by uncorrected raw radar data. In order to verify the impacts on observations due to spatial variation, I-D thresholds are identified from the nearest rain gauge observations and radar observations at the rain gauge locations. It is found that both kinds of observations have similar I-D thresholds and likewise underestimate I-D thresholds due to undershooting at the core of convective

  4. Damage Identification of a Derrick Steel Structure Based on the HHT Marginal Spectrum Amplitude Curvature Difference

    Directory of Open Access Journals (Sweden)

    Dongying Han

    2017-01-01

    Full Text Available For the damage identification of derrick steel structures, traditional methods often require high-order vibration information of structures to identify damage accurately. However, the high-order vibration information of structures is difficult to acquire. Based on the technology of signal feature extraction, only using the low-order vibration information, taking the right front leg as an example, we analyzed the selection of HHT marginal spectrum amplitude and the calculation process of its curvature in practical application, designed the damage conditions of a derrick steel structure, used the index and intrinsic mode function (IMF instantaneous energy curvature method to perform the damage simulation calculation and comparison, and verified the effect of identifying the damage location in a noisy environment. The results show that the index can accurately determine the location of the damage element and weak damage element and can be used to qualitatively analyze the damage degree of the element; under the impact load, the noise hardly affects the identification of the damage location. Finally, this method was applied to the ZJ70 derrick steel structure laboratory model and compared with the IMF instantaneous energy curvature method. We verified the feasibility of this method in the damage location simulation experiment.

  5. Classifying Sluice Occurrences in Dialogue

    DEFF Research Database (Denmark)

    Baird, Austin; Hamza, Anissa; Hardt, Daniel

    2018-01-01

    perform manual annotation with acceptable inter-coder agreement. We build classifier models with Decision Trees and Naive Bayes, with accuracy of 67%. We deploy a classifier to automatically classify sluice occurrences in OpenSubtitles, resulting in a corpus with 1.7 million occurrences. This will support....... Despite this, the corpus can be of great use in research on sluicing and development of systems, and we are making the corpus freely available on request. Furthermore, we are in the process of improving the accuracy of sluice identification and annotation for the purpose of created a subsequent version...

  6. Parametric and Non-Parametric Vibration-Based Structural Identification Under Earthquake Excitation

    Science.gov (United States)

    Pentaris, Fragkiskos P.; Fouskitakis, George N.

    2014-05-01

    The problem of modal identification in civil structures is of crucial importance, and thus has been receiving increasing attention in recent years. Vibration-based methods are quite promising as they are capable of identifying the structure's global characteristics, they are relatively easy to implement and they tend to be time effective and less expensive than most alternatives [1]. This paper focuses on the off-line structural/modal identification of civil (concrete) structures subjected to low-level earthquake excitations, under which, they remain within their linear operating regime. Earthquakes and their details are recorded and provided by the seismological network of Crete [2], which 'monitors' the broad region of south Hellenic arc, an active seismic region which functions as a natural laboratory for earthquake engineering of this kind. A sufficient number of seismic events are analyzed in order to reveal the modal characteristics of the structures under study, that consist of the two concrete buildings of the School of Applied Sciences, Technological Education Institute of Crete, located in Chania, Crete, Hellas. Both buildings are equipped with high-sensitivity and accuracy seismographs - providing acceleration measurements - established at the basement (structure's foundation) presently considered as the ground's acceleration (excitation) and at all levels (ground floor, 1st floor, 2nd floor and terrace). Further details regarding the instrumentation setup and data acquisition may be found in [3]. The present study invokes stochastic, both non-parametric (frequency-based) and parametric methods for structural/modal identification (natural frequencies and/or damping ratios). Non-parametric methods include Welch-based spectrum and Frequency response Function (FrF) estimation, while parametric methods, include AutoRegressive (AR), AutoRegressive with eXogeneous input (ARX) and Autoregressive Moving-Average with eXogeneous input (ARMAX) models[4, 5

  7. Modeling, estimation and identification methods for static shape determination of flexible structures. [for large space structure design

    Science.gov (United States)

    Rodriguez, G.; Scheid, R. E., Jr.

    1986-01-01

    This paper outlines methods for modeling, identification and estimation for static determination of flexible structures. The shape estimation schemes are based on structural models specified by (possibly interconnected) elliptic partial differential equations. The identification techniques provide approximate knowledge of parameters in elliptic systems. The techniques are based on the method of maximum-likelihood that finds parameter values such that the likelihood functional associated with the system model is maximized. The estimation methods are obtained by means of a function-space approach that seeks to obtain the conditional mean of the state given the data and a white noise characterization of model errors. The solutions are obtained in a batch-processing mode in which all the data is processed simultaneously. After methods for computing the optimal estimates are developed, an analysis of the second-order statistics of the estimates and of the related estimation error is conducted. In addition to outlining the above theoretical results, the paper presents typical flexible structure simulations illustrating performance of the shape determination methods.

  8. Structure and pharmacological actions of phyllocaerulein, a caerulein-like nonapeptide: its occurrence in extracts of the skin of Phyllomedusa sauvagei and related Phyllomedusa species.

    Science.gov (United States)

    Anastasi, A; Bertaccini, G; Cei, J M; De Caro, G; Erspamer, V; Impicciatore, M

    1969-09-01

    1. The South American amphibian Phyllomedusa sauvagei contains in its skin large amounts of a polypeptide closely resembling caerulein in its pharmacological actions. This polypeptide, called phyllocaerulein, was obtained in a pure form, and upon acid hydrolysis, enzymic digestion and end-group determination experiments it proved to be a nonapeptide of the following composition Pyr-Glu-Tyr(SO(3)H)-Thr-Gly-Trp-Met-Asp-Phe-NH(2)It may be seen that caerulein and phyllocaerulein have in common the C-terminal heptapeptide and the N-terminal pyroglutamyl residue.2. Phyllocaerulein is indistinguishable from caerulein even in parallel bioassay. However, the former polypeptide seems to be somewhat more potent than the latter on all the preparations tested.3. In different batches of Phyllomedusa sauvagei skin the phyllocaerulein content ranged between 150 and 600 mug/g of fresh tissue.Phyllocaerulein or similar polypeptides occur also in the skin of several other Phyllomedusa species, among which are Phyll. burmeisteri, Phyll. dachnicolor, Phyll, helenae, Phyll. annae, Phyll. callidryas and Phyll. bicolor.4. The qualitative identification and quantitative estimation of caerulein-like polypeptides in crude skin extracts may be complicated by the concomitant occurrence of other active polypeptides. These, however, are poorly effective on some test preparations which seem to respond selectively to caerulein.5. Like that of caerulein, the biological significance of phyllocaerulein is completely obscure.

  9. Uncertainty Quantification in Experimental Structural Dynamics Identification of Composite Material Structures

    DEFF Research Database (Denmark)

    Luczak, Marcin; Peeters, Bart; Kahsin, Maciej

    2014-01-01

    for uncertainty evaluation in experimentally estimated models. Investigated structures are plates, fuselage panels and helicopter main rotor blades as they represent different complexity levels ranging from coupon, through sub-component up to fully assembled structures made of composite materials. To evaluate......Aerospace and wind energy structures are extensively using components made of composite materials. Since these structures are subjected to dynamic environments with time-varying loading conditions, it is important to model their dynamic behavior and validate these models by means of vibration...

  10. EEMD-MUSIC-Based Analysis for Natural Frequencies Identification of Structures Using Artificial and Natural Excitations

    Directory of Open Access Journals (Sweden)

    David Camarena-Martinez

    2014-01-01

    Full Text Available This paper presents a new EEMD-MUSIC- (ensemble empirical mode decomposition-multiple signal classification- based methodology to identify modal frequencies in structures ranging from free and ambient vibration signals produced by artificial and natural excitations and also considering several factors as nonstationary effects, close modal frequencies, and noisy environments, which are common situations where several techniques reported in literature fail. The EEMD and MUSIC methods are used to decompose the vibration signal into a set of IMFs (intrinsic mode functions and to identify the natural frequencies of a structure, respectively. The effectiveness of the proposed methodology has been validated and tested with synthetic signals and under real operating conditions. The experiments are focused on extracting the natural frequencies of a truss-type scaled structure and of a bridge used for both highway traffic and pedestrians. Results show the proposed methodology as a suitable solution for natural frequencies identification of structures from free and ambient vibration signals.

  11. EEMD-MUSIC-Based Analysis for Natural Frequencies Identification of Structures Using Artificial and Natural Excitations

    Science.gov (United States)

    Amezquita-Sanchez, Juan P.; Romero-Troncoso, Rene J.; Osornio-Rios, Roque A.; Garcia-Perez, Arturo

    2014-01-01

    This paper presents a new EEMD-MUSIC- (ensemble empirical mode decomposition-multiple signal classification-) based methodology to identify modal frequencies in structures ranging from free and ambient vibration signals produced by artificial and natural excitations and also considering several factors as nonstationary effects, close modal frequencies, and noisy environments, which are common situations where several techniques reported in literature fail. The EEMD and MUSIC methods are used to decompose the vibration signal into a set of IMFs (intrinsic mode functions) and to identify the natural frequencies of a structure, respectively. The effectiveness of the proposed methodology has been validated and tested with synthetic signals and under real operating conditions. The experiments are focused on extracting the natural frequencies of a truss-type scaled structure and of a bridge used for both highway traffic and pedestrians. Results show the proposed methodology as a suitable solution for natural frequencies identification of structures from free and ambient vibration signals. PMID:24683346

  12. Identification and Structural Basis of Binding to Host Lung Glycogen by Streptococcal Virulence Factors

    Energy Technology Data Exchange (ETDEWEB)

    Lammerts van Bueren,A.; Higgins, M.; Wang, D.; Burke, R.; Boraston, A.

    2007-01-01

    The ability of pathogenic bacteria to recognize host glycans is often essential to their virulence. Here we report structure-function studies of previously uncharacterized glycogen-binding modules in the surface-anchored pullulanases from Streptococcus pneumoniae (SpuA) and Streptococcus pyogenes (PulA). Multivalent binding to glycogen leads to a strong interaction with alveolar type II cells in mouse lung tissue. X-ray crystal structures of the binding modules reveal a novel fusion of tandem modules into single, bivalent functional domains. In addition to indicating a structural basis for multivalent attachment, the structure of the SpuA modules in complex with carbohydrate provides insight into the molecular basis for glycogen specificity. This report provides the first evidence that intracellular lung glycogen may be a novel target of pathogenic streptococci and thus provides a rationale for the identification of the streptococcal {alpha}-glucan-metabolizing machinery as virulence factors.

  13. OPTIMAL REPRESENTATION OF MER SIGNALS APPLIED TO THE IDENTIFICATION OF BRAIN STRUCTURES DURING DEEP BRAIN STIMULATION

    Directory of Open Access Journals (Sweden)

    Hernán Darío Vargas Cardona

    2015-07-01

    Full Text Available Identification of brain signals from microelectrode recordings (MER is a key procedure during deep brain stimulation (DBS applied in Parkinson’s disease patients. The main purpose of this research work is to identify with high accuracy a brain structure called subthalamic nucleus (STN, since it is the target structure where the DBS achieves the best therapeutic results. To do this, we present an approach for optimal representation of MER signals through method of frames. We obtain coefficients that minimize the Euclidean norm of order two. From optimal coefficients, we extract some features from signals combining the wavelet packet and cosine dictionaries. For a comparison frame with the state of the art, we also process the signals using the discrete wavelet transform (DWT with several mother functions. We validate the proposed methodology in a real data base. We employ simple supervised machine learning algorithms, as the K-Nearest Neighbors classifier (K-NN, a linear Bayesian classifier (LDC and a quadratic Bayesian classifier (QDC. Classification results obtained with the proposed method improves significantly the performance of the DWT. We achieve a positive identification of the STN superior to 97,6%. Identification outcomes achieved by the MOF are highly accurate, as we can potentially get a false positive rate of less than 2% during the DBS.

  14. A Subspace Approach to the Structural Decomposition and Identification of Ankle Joint Dynamic Stiffness.

    Science.gov (United States)

    Jalaleddini, Kian; Tehrani, Ehsan Sobhani; Kearney, Robert E

    2017-06-01

    The purpose of this paper is to present a structural decomposition subspace (SDSS) method for decomposition of the joint torque to intrinsic, reflexive, and voluntary torques and identification of joint dynamic stiffness. First, it formulates a novel state-space representation for the joint dynamic stiffness modeled by a parallel-cascade structure with a concise parameter set that provides a direct link between the state-space representation matrices and the parallel-cascade parameters. Second, it presents a subspace method for the identification of the new state-space model that involves two steps: 1) the decomposition of the intrinsic and reflex pathways and 2) the identification of an impulse response model of the intrinsic pathway and a Hammerstein model of the reflex pathway. Extensive simulation studies demonstrate that SDSS has significant performance advantages over some other methods. Thus, SDSS was more robust under high noise conditions, converging where others failed; it was more accurate, giving estimates with lower bias and random errors. The method also worked well in practice and yielded high-quality estimates of intrinsic and reflex stiffnesses when applied to experimental data at three muscle activation levels. The simulation and experimental results demonstrate that SDSS accurately decomposes the intrinsic and reflex torques and provides accurate estimates of physiologically meaningful parameters. SDSS will be a valuable tool for studying joint stiffness under functionally important conditions. It has important clinical implications for the diagnosis, assessment, objective quantification, and monitoring of neuromuscular diseases that change the muscle tone.

  15. A stochastic global identification framework for aerospace structures operating under varying flight states

    Science.gov (United States)

    Kopsaftopoulos, Fotis; Nardari, Raphael; Li, Yu-Hung; Chang, Fu-Kuo

    2018-01-01

    In this work, a novel data-based stochastic "global" identification framework is introduced for aerospace structures operating under varying flight states and uncertainty. In this context, the term "global" refers to the identification of a model that is capable of representing the structure under any admissible flight state based on data recorded from a sample of these states. The proposed framework is based on stochastic time-series models for representing the structural dynamics and aeroelastic response under multiple flight states, with each state characterized by several variables, such as the airspeed, angle of attack, altitude and temperature, forming a flight state vector. The method's cornerstone lies in the new class of Vector-dependent Functionally Pooled (VFP) models which allow the explicit analytical inclusion of the flight state vector into the model parameters and, hence, system dynamics. This is achieved via the use of functional data pooling techniques for optimally treating - as a single entity - the data records corresponding to the various flight states. In this proof-of-concept study the flight state vector is defined by two variables, namely the airspeed and angle of attack of the vehicle. The experimental evaluation and assessment is based on a prototype bio-inspired self-sensing composite wing that is subjected to a series of wind tunnel experiments under multiple flight states. Distributed micro-sensors in the form of stretchable sensor networks are embedded in the composite layup of the wing in order to provide the sensing capabilities. Experimental data collected from piezoelectric sensors are employed for the identification of a stochastic global VFP model via appropriate parameter estimation and model structure selection methods. The estimated VFP model parameters constitute two-dimensional functions of the flight state vector defined by the airspeed and angle of attack. The identified model is able to successfully represent the wing

  16. Single crystal structure analyses of scheelite-powellite CaW1-xMoxO4 solidsolutions and unique occurrence in Jisyakuyama skarn deposits

    Science.gov (United States)

    Yamashita, K.; Yoshiasa, A.; Miyazaki, H.; Tokuda, M.; Tobase, T.; Isobe, H.; Nishiyama, T.; Sugiyama, K.; Miyawaki, R.

    2017-12-01

    Jisyakuyama skarn deposit, Fukuchi, Fukuoka, Japan, shows a simple occurrenceformed by penetration of hot water into limestone cracks. A unique occurrence of scheelite-powellite CaW1-xMoxO4 minerals is observed in the skarn deposit. Many syntheticexperiments for scheelite-powellite solid solutions have been reported as research onfluorescent materials. In this system it is known that a complete continuous solid solution isformed even at room temperature. In this study, we have carried out the chemical analyses,crystal structural refinements and detail description of occurrence on scheelite-powelliteminerals. We have also attempted synthesis of single crystal of solid solution in a widecomposition range. The chemical compositions were determined by JEOL scanningelectron microscope and EDS, INCA system. We have performed the crystal structurerefinements of the scheelite-powellite CaW1-xMoxO4 solid solutions (x=0.0-1.0) byRIGAKU single-crystal structure analysis system RAPID. The R and S values are around0.0s and 1.03. As the result of structural refinements of natural products and many solidsolutions, we confirm that most large natural single crystals have compositions at bothendmembers, and large solid solution crystals are rare. The lattice constants, interatomicdistances and other crystallographic parameters for the solid solution change uniquely withcomposition and it was confirmed as a continuous solid solution. Single crystals of scheeliteendmember + powellite endmember + solid solution with various compositions form anaggregate in the deposit (Figure 1). Crystal shapes of powellite and scheelite arehypidiomorphic and allotriomorphic, respectively. Many solid solution crystals areaccompanied by scheelite endmember and a compositional gap is observed betweenpowellite and solid-solution crystals. The presence of several penetration solutions withsignificantly different W and Mo contents may be assumed. This research can be expectedto lead to giving restrictive

  17. An approach to large scale identification of non-obvious structural similarities between proteins

    Science.gov (United States)

    Cherkasov, Artem; Jones, Steven JM

    2004-01-01

    Background A new sequence independent bioinformatics approach allowing genome-wide search for proteins with similar three dimensional structures has been developed. By utilizing the numerical output of the sequence threading it establishes putative non-obvious structural similarities between proteins. When applied to the testing set of proteins with known three dimensional structures the developed approach was able to recognize structurally similar proteins with high accuracy. Results The method has been developed to identify pathogenic proteins with low sequence identity and high structural similarity to host analogues. Such protein structure relationships would be hypothesized to arise through convergent evolution or through ancient horizontal gene transfer events, now undetectable using current sequence alignment techniques. The pathogen proteins, which could mimic or interfere with host activities, would represent candidate virulence factors. The developed approach utilizes the numerical outputs from the sequence-structure threading. It identifies the potential structural similarity between a pair of proteins by correlating the threading scores of the corresponding two primary sequences against the library of the standard folds. This approach allowed up to 64% sensitivity and 99.9% specificity in distinguishing protein pairs with high structural similarity. Conclusion Preliminary results obtained by comparison of the genomes of Homo sapiens and several strains of Chlamydia trachomatis have demonstrated the potential usefulness of the method in the identification of bacterial proteins with known or potential roles in virulence. PMID:15147578

  18. An approach to large scale identification of non-obvious structural similarities between proteins

    Directory of Open Access Journals (Sweden)

    Cherkasov Artem

    2004-05-01

    Full Text Available Abstract Background A new sequence independent bioinformatics approach allowing genome-wide search for proteins with similar three dimensional structures has been developed. By utilizing the numerical output of the sequence threading it establishes putative non-obvious structural similarities between proteins. When applied to the testing set of proteins with known three dimensional structures the developed approach was able to recognize structurally similar proteins with high accuracy. Results The method has been developed to identify pathogenic proteins with low sequence identity and high structural similarity to host analogues. Such protein structure relationships would be hypothesized to arise through convergent evolution or through ancient horizontal gene transfer events, now undetectable using current sequence alignment techniques. The pathogen proteins, which could mimic or interfere with host activities, would represent candidate virulence factors. The developed approach utilizes the numerical outputs from the sequence-structure threading. It identifies the potential structural similarity between a pair of proteins by correlating the threading scores of the corresponding two primary sequences against the library of the standard folds. This approach allowed up to 64% sensitivity and 99.9% specificity in distinguishing protein pairs with high structural similarity. Conclusion Preliminary results obtained by comparison of the genomes of Homo sapiens and several strains of Chlamydia trachomatis have demonstrated the potential usefulness of the method in the identification of bacterial proteins with known or potential roles in virulence.

  19. On the Optimal Location of Sensors for Parametric Identification of Linear Structural Systems

    DEFF Research Database (Denmark)

    Kirkegaard, Poul Henning; Brincker, Rune

    A survey of the field of optimal location of sensors for parametric identification of linear structural systems is presented. The survey shows that few papers are devoted to the case of optimal location sensors in which the measurements are modelled by a random field with non-trivial covariance...... function. Most often it is assumed that the results of the measurements are statistically independent variables. In an example the importance of considering the measurements as statistically dependent random variables is shown. The example is concerned with optimal location of sensors for parametric...... identification of modal parameters for a vibrating beam under random loading. The covariance of the modal parameters expected to be obtained is investigated to variations of number and location of sensors. Further, the influence of the noise on the optimal location of the sensors is investigated....

  20. Structure Identification Using the US EPA's CompTox Chemistry Dashboard (CompTox CoP)

    Science.gov (United States)

    Community of practice webinar presentation on the Identification of unknowns in non-targeted analyses (NTA) requires the integration of complementary data types to generate a confident consensus structure.

  1. Structure identification by Mass Spectrometry Non-Targeted Analysis using the US EPA’s CompTox Chemistry Dashboard

    Science.gov (United States)

    Identification of unknowns in mass spectrometry based non-targeted analyses (NTA) requires the integration of complementary pieces of data to arrive at a confident, consensus structure. Researchers use chemical reference databases, spectral matching, fragment prediction tools, r...

  2. Methods of the Detection and Identification of Structural Defects in Saturated Metallic Composite Castings

    Directory of Open Access Journals (Sweden)

    Gawdzińska K.

    2017-09-01

    Full Text Available Diagnostics of composite castings, due to their complex structure, requires that their characteristics are tested by an appropriate description method. Any deviation from the specific characteristic will be regarded as a material defect. The detection of defects in composite castings sometimes is not sufficient and the defects have to be identified. This study classifies defects found in the structures of saturated metallic composite castings and indicates those stages of the process where such defects are likely to be formed. Not only does the author determine the causes of structural defects, describe methods of their detection and identification, but also proposes a schematic procedure to be followed during detection and identification of structural defects of castings made from saturated reinforcement metallic composites. Alloys examination was conducted after technological process, while using destructive (macroscopic tests, light and scanning electron microscopy and non-destructive (ultrasonic and X-ray defectoscopy, tomography, gravimetric method methods. Research presented in this article are part of author’s work on castings quality.

  3. Cross-Correlation-Based Structural System Identification Using Unmanned Aerial Vehicles

    Directory of Open Access Journals (Sweden)

    Hyungchul Yoon

    2017-09-01

    Full Text Available Computer vision techniques have been employed to characterize dynamic properties of structures, as well as to capture structural motion for system identification purposes. All of these methods leverage image-processing techniques using a stationary camera. This requirement makes finding an effective location for camera installation difficult, because civil infrastructure (i.e., bridges, buildings, etc. are often difficult to access, being constructed over rivers, roads, or other obstacles. This paper seeks to use video from Unmanned Aerial Vehicles (UAVs to address this problem. As opposed to the traditional way of using stationary cameras, the use of UAVs brings the issue of the camera itself moving; thus, the displacements of the structure obtained by processing UAV video are relative to the UAV camera. Some efforts have been reported to compensate for the camera motion, but they require certain assumptions that may be difficult to satisfy. This paper proposes a new method for structural system identification using the UAV video directly. Several challenges are addressed, including: (1 estimation of an appropriate scale factor; and (2 compensation for the rolling shutter effect. Experimental validation is carried out to validate the proposed approach. The experimental results demonstrate the efficacy and significant potential of the proposed approach.

  4. Proteome scale identification, classification and structural analysis of iron-binding proteins in bread wheat.

    Science.gov (United States)

    Verma, Shailender Kumar; Sharma, Ankita; Sandhu, Padmani; Choudhary, Neha; Sharma, Shailaja; Acharya, Vishal; Akhter, Yusuf

    2017-05-01

    Bread wheat is one of the major staple foods of worldwide population and iron plays a significant role in growth and development of the plant. In this report, we are presenting the genome wide identification of iron-binding proteins in bread wheat. The wheat genome derived putative proteome was screened for identification of iron-binding sequence motifs. Out of 602 putative iron-binding proteins, 130 were able to produce reliable structural models by homology techniques and further analyzed for the presence of iron-binding structural motifs. The computationally identified proteins appear to bind to ferrous and ferric ions and showed diverse coordination geometries. Glu, His, Asp and Cys amino acid residues were found to be mostly involved in iron binding. We have classified these proteins on the basis of their localization in the different cellular compartments. The identified proteins were further classified into their protein folds, families and functional classes ranging from structure maintenance of cellular components, regulation of gene expression, post translational modification, membrane proteins, enzymes, signaling and storage proteins. This comprehensive report regarding structural iron binding proteome provides useful insights into the diversity of iron binding proteins of wheat plants and further utilized to study their roles in plant growth, development and physiology. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Identification of crystalline structures using Moessbauer parameters and artificial neural network

    International Nuclear Information System (INIS)

    Salles, E.O.T.; Souza Junior, P.A. De; Garg, V.K.

    1995-01-01

    Moessbauer spectroscopy is a useful technique for characterizing the valences, electronic and magnetic states, coordination symmetric and site occupancies of Fe cations. The Moessbauer parameters of Isomer Shift (I.S.) and Quadrupole Splitting (Q.S.) are useful to distinguish paramagnetic ferrous and ferric ions in several substances, while the internal magnetic field provides information on the crystallinity. A correlation is being sought between Moessbauer parameters and several structure properties of some iron-containing minerals using Artificial Neural Networks (ANN). Distinct regions of crystalline structures are defined when any two parameters are plotted, but in several cases superposition of these regions leads to erroneous conclusions. We have tried to eliminate this difficulty by using convenient axes. These axes form n-dimensional vectors as input to our ANN. In recent years ANN has shown to be a powerful technique to solve problems as pattern recognition, optimization, preview ups and downs in stock market, automatic control and identification of a mineral from a Moessbauer spectrum of Moessbauer data bank. Using ANN we have been successful in identification of crystalline structures from plots of Moessbauer spectral parameters of I.S., Q.S., and structure using Moessbauer parameters of I.S., Q.S., and polyhedral volume of a coordination site are presented. (author) 28 refs.; 4 figs.; 2 tabs

  6. The occurrence of dynamic structural disorders in the pharynx and larynx, at rest and during exercise, in horses diagnosed with mild and moderate Equine Asthma (Inflammatory Airway Disease).

    Science.gov (United States)

    Wysocka, B; Kluciński, W

    2018-03-01

    The goal of the present study was to establish the occurrence of structural disorders in the larynx and pharynx during treadmill exercise tests in horses diagnosed with Equine Asthma (EA). Investigation was performed in 29 horses, patients of the Equine Clinic of the Warsaw University of Life Sciences in Poland, admitted with poor exercise performance. Upper and lower airway examinations were performed in all patients revealing both mild to moderate Equine Asthma (13 horses), and no lower airway abnormalities (16 animals). In the group of horses with EA, 11 did not have structural disorders of the pharynx and larynx at rest. During exercise two horses were free of abnormalities, while 11 had structural disorders, eight of them solely in the pharynx, two in the larynx, and one in both the pharynx and larynx. In the non- asthmatic group, 11 horses had no structural disorders during resting endoscopy. Endoscopy performed during exercise revealed disorders of the larynx in 10 horses, of the pharynx in three horses, and in both the larynx and pharynx in the remaining three horses. horses with diagnosed EA frequently have disorders of the pharynx during treadmill exercise tests, while without EA, often have disorders of the larynx. Endoscopy of upper airways during exercise testing is a valuable tool in the diagnosis of poor performance in horses with lower airway inflammatory disease. Copyright© by the Polish Academy of Sciences.

  7. Quantitative identification and analysis of sub-seismic extensional structure system: technique schemes and processes

    International Nuclear Information System (INIS)

    Chenghua, Ou; Chen, Wei; Ma, Zhonggao

    2015-01-01

    Quantitative characterization of complex sub-seismic extensional structure system that essentially controls petroleum exploitation is difficult to implement in seismic profile interpretation. This research, based on a case study in block M of Myanmar, established a set of quantitative treatment schemes and technique processes for the identification of sub-seismic low-displacement (SSLD) extensional faults or fractures upon structural deformation restoration and geometric inversion. Firstly, the master-subsidiary inheritance relations and configuration of the seismic-scale extensional fault systems are determined by analyzing the structural pattern. Besides, three-dimensional (3D) pattern and characteristics of the seismic-scale extensional structure have been illustrated by a 3D structure model built upon seismic sections. Moreover, according to the dilatancy obtained from structural restoration on the basis of inclined shear method, as well as the fracture-flow index, potential SSLD extensional faults or fractures have been quantitatively identified. Application of the technique processes to the sub-seismic low-displacement extensional structures in block M in Myanmar is instructive to quantitatively interpret those SSLD extensional structure systems in practice. (paper)

  8. The Occurrence, Biosynthesis, and Molecular Structure of Proanthocyanidins and Their Effects on Legume Forage Protein Precipitation, Digestion and Absorption in the Ruminant Digestive Tract

    Directory of Open Access Journals (Sweden)

    Arjan Jonker

    2017-05-01

    Full Text Available Forages grown in temperate regions, such as alfalfa (Medicago sativa L. and white clover (Trefolium repens L., typically have a high nutritional value when fed to ruminants. Their high protein content and degradation rate result, however, in poor utilization of protein from the forage resulting in excessive excretion of nitrogen into the environment by the animal. Proanthocyanindins (also known as condensed tannins found in some forage legumes such as birdsfoot trefoil (Lotus corniculatus L., bind to dietary protein and can improve protein utilization in the animal. This review will focus on (1 the occurrence of proanthocyanidins; (2 biosynthesis and structure of proanthocyanidins; (3 effects of proanthocyanidins on protein metabolism; (4 protein precipitating capacity of proanthocyanidins and their effects on true intestinal protein adsorption by ruminants; and (5 effect on animal health, animal performance and environmental emissions.

  9. Lead-Antimony Sulfosalts from Tuscany (Italy. XX. Members of the Jordanite–Geocronite Series from the Pollone Mine, Valdicastello Carducci: Occurrence and Crystal Structures

    Directory of Open Access Journals (Sweden)

    Cristian Biagioni

    2016-02-01

    Full Text Available A crystal-chemical study of historical specimens as well as new ones belonging to the jordanite–geocronite series from the Pollone baryte + pyrite ± (Pb-Zn-Ag ore deposit (Valdicastello Carducci, Apuan Alps, Tuscany, Italy has been performed. These crystals were collected in quartz extension veins embedded in three different occurrences: (i baryte + pyrite orebodies; (ii schist layers interbedded between baryte + pyrite orebodies; and (iii schists at the contact with pyrite-poor baryte orebodies. Electron-microprobe data indicated the occurrence of three distinct groups of compositions within the sample suite. These correspond to As-bearing geocronite, Sb-rich jordanite, and Sb-bearing jordanite, with mean compositions Pb14Sb3.8As2.2S23, Pb14Sb2.9As3.1S23, and Pb14Sb2.6As3.4S23, respectively. Crystals representative of these different compositions have been investigated through single-crystal X-Ray diffraction studies and their crystal structures have been solved to R1 = 0.078, 0.069, and 0.033, respectively. The unit-cell volume decreases passing through As-bearing geocronite (V = 2149.5(3 Å3 to Sb-bearing jordanite (V = 2132.3(3 Å3. The As-to-Sb substitution takes place preferentially at the Sb4 site; through the increasing of the Sb content, Sb can substitute As also at the As6 site. According to the structural study of the ore deposit, formation of jordanite–geocronite is subordinated to a late Alpine deformative D2 stage, which permitted in situ remobilization of preexisting sulfide ore in small quartz extension veins. Such a local recrystallization would explain the variability of the As/(As + Sb ratio of the members of the jordanite series, reflecting the heterogeneity of the orebody.

  10. Combination of geophysical prospecting techniques into areas of high protection value: Identification of shallow volcanic structures

    Science.gov (United States)

    Gómez-Ortiz, David; Montesinos, Fuensanta G.; Martín-Crespo, Tomás; Solla, Mercedes; Arnoso, José; Vélez, Emilio

    2014-10-01

    Timanfaya National Park is a volcanic area located in the southwest of Lanzarote Island (Canary Islands, Spain). Several lava tubes have been found in the lava flows but many others remain unknown. Its location and identification are important to mitigate collapse hazards in this touristic area. We present a new study about the location of recent lava tubes by the analysis and joint interpretation of ground penetrating radar (GPR), microgravity and electromagnetic induction (EMI) data along the same profile over an area not previously surveyed. GPR data display a complex pattern of reflections up to ~ 10 m depth. The strongest hyperbolic reflections can be grouped in four different areas. Visual inspections carried out in the field allow confirming the occurrence of lava tubes at two of them. These reflections have been interpreted as the effect of the roof and bottom interfaces of several lava tubes. The microgravity survey defines a wide gravity low with several over-imposed minor highs and lows. Using the GPR data, a 2.5D gravity model has been obtained revealing four lava tubes. EMI data have been used to obtain an inverted resistivity model that displays four high resistivity areas that closely match the locations of the lava tubes derived from the previous methods. This resistivity model exhibits the lower resolution although reaches a deeper investigation depth (~ 20 m). The comparison of the results has revealed that joint interpretation of GPR, microgravity and EMI methods provides reliable models useful for the detection of unknown shallow lava tubes.

  11. Bayesian nonlinear structural FE model and seismic input identification for damage assessment of civil structures

    Science.gov (United States)

    Astroza, Rodrigo; Ebrahimian, Hamed; Li, Yong; Conte, Joel P.

    2017-09-01

    A methodology is proposed to update mechanics-based nonlinear finite element (FE) models of civil structures subjected to unknown input excitation. The approach allows to jointly estimate unknown time-invariant model parameters of a nonlinear FE model of the structure and the unknown time histories of input excitations using spatially-sparse output response measurements recorded during an earthquake event. The unscented Kalman filter, which circumvents the computation of FE response sensitivities with respect to the unknown model parameters and unknown input excitations by using a deterministic sampling approach, is employed as the estimation tool. The use of measurement data obtained from arrays of heterogeneous sensors, including accelerometers, displacement sensors, and strain gauges is investigated. Based on the estimated FE model parameters and input excitations, the updated nonlinear FE model can be interrogated to detect, localize, classify, and assess damage in the structure. Numerically simulated response data of a three-dimensional 4-story 2-by-1 bay steel frame structure with six unknown model parameters subjected to unknown bi-directional horizontal seismic excitation, and a three-dimensional 5-story 2-by-1 bay reinforced concrete frame structure with nine unknown model parameters subjected to unknown bi-directional horizontal seismic excitation are used to illustrate and validate the proposed methodology. The results of the validation studies show the excellent performance and robustness of the proposed algorithm to jointly estimate unknown FE model parameters and unknown input excitations.

  12. Dynamics of Practical Premixed Flames, Part I: Model Structure and Identification

    Directory of Open Access Journals (Sweden)

    A. Huber

    2009-06-01

    Full Text Available For the analysis of thermoacoustic instabilities it is most important to determine the dynamic flame response to acoustic disturbances. Premixed flames are often modelled as single-input single-output system, where the “output” (the overall rate of heat release responds to a single “input” variable (often the velocity at the exit of the burner nozzle. However, for practical premixed flames, where perturbations of pressure or velocity at the fuel injector will modulate the fuel equivalence ratio, the heat release rate will respond to fluctuations of equivalence ratio as well as nozzle mass flow rate. In this case, a multiple-input, single-output (MISO model structure for the flame is appropriate. Such a model structure is developed in the present paper. Staged fuel injection as well as fuel line impedances can be taken into account, the integration with low-order or finite-element based models for stability analysis is straightforward. In order to determine unit impulse and frequency response functions for such a model structure, an identification scheme based on unsteady CFD calculation with broadband excitation followed by correlation analysis is proposed and validated successfully. Identification of MISO model coefficients is a challenging task, especially in the presence of noise. Therefore criteria are introduced which allow to ascertain a posteriori how well the identified model represents the true system dynamics. Using these criteria, it is investigated how excitation signal type, time series length and signal-to-noise ratio influence the results of the identification process. Consequences for passive design strategies based on multi-stage fuel injection and experimental work on practical premixed flame dynamics are discussed.

  13. Global occurrence of polybrominated diphenyl ethers and their hydroxylated and methoxylated structural analogues in an important animal feed (fishmeal).

    Science.gov (United States)

    Li, Xiaomin; Dong, Shujun; Zhang, Wei; Fan, Xia; Li, Yang; Wang, Ruiguo; Su, Xiaoou

    2018-03-01

    Polybrominated diphenyl ethers (PBDEs) and their hydroxylated (OH) and methoxylated (MeO) structural analogues have been found widely distributed in aquatic ecosystems, and may exhibit potential adverse effects to humans due to their bioaccumulative behavior through food chain. Fishmeal is an important animal feed applied around the world and is generally of marine origin. However, the levels and sources of PBDEs in fishmeal have not been thoroughly evaluated and their structural analogues have not been reported to date. The present study collected ninety-two fishmeal samples from world main fishmeal producing area to determine 27 PBDEs, 10 MeO-PBDEs and 11 OH-PBDEs. The concentrations of Σ 27 PBDEs, Σ 10 MeO-PBDEs and Σ 11 OH-PBDEs were in the ranges of 0.1-1498 (mean: 75.8), 1.14-881 (37.4) and 1.00-47.5 (8.17) ng/g lipid, respectively. PBDEs were found primarily correlated with the historically commercial production, meaning higher production of certain commercial product in a country, higher corresponding PBDE congeners in local fishmeal. A market shift from penta- and octa-formulations toward deca-formulation was observed. BDE209 was identified as a major congener in fishmeal. Both the MeO-PBDEs and the OH-PBDEs were influenced by fishmeal producing areas (p 1 in the northern hemisphere and <1 in the southern hemisphere in the present study, which was consistent with the results obtained from previous published papers. Both MeO-PBDEs and OH-PBDEs were in accordance with the specialties of naturally produced halogenated compounds. Copyright © 2017. Published by Elsevier Ltd.

  14. A Novel Coupled State/Input/Parameter Identification Method for Linear Structural Systems

    Directory of Open Access Journals (Sweden)

    Zhimin Wan

    2018-01-01

    Full Text Available In many engineering applications, unknown states, inputs, and parameters exist in the structures. However, most methods require one or two of these variables to be known in order to identify the other(s. Recently, the authors have proposed a method called EGDF for coupled state/input/parameter identification for nonlinear system in state space. However, the EGDF method based solely on acceleration measurements is found to be unstable, which can cause the drift of the identified inputs and displacements. Although some regularization methods can be adopted for solving the problem, they are not suitable for joint input-state identification in real time. In this paper, a strategy of data fusion of displacement and acceleration measurements is used to avoid the low-frequency drift in the identified inputs and structural displacements for linear structural systems. Two numerical examples about a plane truss and a single-stage isolation system are conducted to verify the effectiveness of the proposed modified EGDF algorithm.

  15. Distributed Piezoelectric Sensor System for Damage Identification in Structures Subjected to Temperature Changes.

    Science.gov (United States)

    Vitola, Jaime; Pozo, Francesc; Tibaduiza, Diego A; Anaya, Maribel

    2017-05-31

    Structural health monitoring (SHM) is a very important area in a wide spectrum of fields and engineering applications. With an SHM system, it is possible to reduce the number of non-necessary inspection tasks, the associated risk and the maintenance cost in a wide range of structures during their lifetime. One of the problems in the detection and classification of damage are the constant changes in the operational and environmental conditions. Small changes of these conditions can be considered by the SHM system as damage even though the structure is healthy. Several applications for monitoring of structures have been developed and reported in the literature, and some of them include temperature compensation techniques. In real applications, however, digital processing technologies have proven their value by: (i) offering a very interesting way to acquire information from the structures under test; (ii) applying methodologies to provide a robust analysis; and (iii) performing a damage identification with a practical useful accuracy. This work shows the implementation of an SHM system based on the use of piezoelectric (PZT) sensors for inspecting a structure subjected to temperature changes. The methodology includes the use of multivariate analysis, sensor data fusion and machine learning approaches. The methodology is tested and evaluated with aluminum and composite structures that are subjected to temperature variations. Results show that damage can be detected and classified in all of the cases in spite of the temperature changes.

  16. Distributed Piezoelectric Sensor System for Damage Identification in Structures Subjected to Temperature Changes

    Directory of Open Access Journals (Sweden)

    Jaime Vitola

    2017-05-01

    Full Text Available Structural health monitoring (SHM is a very important area in a wide spectrum of fields and engineering applications. With an SHM system, it is possible to reduce the number of non-necessary inspection tasks, the associated risk and the maintenance cost in a wide range of structures during their lifetime. One of the problems in the detection and classification of damage are the constant changes in the operational and environmental conditions. Small changes of these conditions can be considered by the SHM system as damage even though the structure is healthy. Several applications for monitoring of structures have been developed and reported in the literature, and some of them include temperature compensation techniques. In real applications, however, digital processing technologies have proven their value by: (i offering a very interesting way to acquire information from the structures under test; (ii applying methodologies to provide a robust analysis; and (iii performing a damage identification with a practical useful accuracy. This work shows the implementation of an SHM system based on the use of piezoelectric (PZT sensors for inspecting a structure subjected to temperature changes. The methodology includes the use of multivariate analysis, sensor data fusion and machine learning approaches. The methodology is tested and evaluated with aluminum and composite structures that are subjected to temperature variations. Results show that damage can be detected and classified in all of the cases in spite of the temperature changes.

  17. An Introduction to Operational Modal Identification of Offshore Wind Turbine Structures

    DEFF Research Database (Denmark)

    Damgaard, Mads

    excitation originating from the rotating rotor and broadband excitation from air turbulence is present, which sets limitations on the applicability of operational modal analysis to wind turbine structures. The technical memorandum contains an introduction to the theory within experimental modal analysis and......The present technical memorandum “An Introduction to Operational Modal Identification of Offshore Wind Turbine Structures” is prepared in connection with an ongoing Ph.D study at Aalborg University. The memorandum is intended for use in the civil engineering field and may serve as an inspiration...

  18. An Optimal Image-Based Method for Identification of Acoustic Emission (AE) Sources in Plate-Like Structures Using a Lead Zirconium Titanate (PZT) Sensor Array

    Science.gov (United States)

    Zhou, Li

    2018-01-01

    This paper proposes an innovative method for identifying the locations of multiple simultaneous acoustic emission (AE) events in plate-like structures from the view of image processing. By using a linear lead zirconium titanate (PZT) sensor array to record the AE wave signals, a reverse-time frequency-wavenumber (f-k) migration is employed to produce images displaying the locations of AE sources by back-propagating the AE waves. Lamb wave theory is included in the f-k migration to consider the dispersive property of the AE waves. Since the exact occurrence time of the AE events is usually unknown when recording the AE wave signals, a heuristic artificial bee colony (ABC) algorithm combined with an optimal criterion using minimum Shannon entropy is used to find the image with the identified AE source locations and occurrence time that mostly approximate the actual ones. Experimental studies on an aluminum plate with AE events simulated by PZT actuators are performed to validate the applicability and effectiveness of the proposed optimal image-based AE source identification method. PMID:29466310

  19. An Optimal Image-Based Method for Identification of Acoustic Emission (AE) Sources in Plate-Like Structures Using a Lead Zirconium Titanate (PZT) Sensor Array.

    Science.gov (United States)

    Yan, Gang; Zhou, Li

    2018-02-21

    This paper proposes an innovative method for identifying the locations of multiple simultaneous acoustic emission (AE) events in plate-like structures from the view of image processing. By using a linear lead zirconium titanate (PZT) sensor array to record the AE wave signals, a reverse-time frequency-wavenumber (f-k) migration is employed to produce images displaying the locations of AE sources by back-propagating the AE waves. Lamb wave theory is included in the f-k migration to consider the dispersive property of the AE waves. Since the exact occurrence time of the AE events is usually unknown when recording the AE wave signals, a heuristic artificial bee colony (ABC) algorithm combined with an optimal criterion using minimum Shannon entropy is used to find the image with the identified AE source locations and occurrence time that mostly approximate the actual ones. Experimental studies on an aluminum plate with AE events simulated by PZT actuators are performed to validate the applicability and effectiveness of the proposed optimal image-based AE source identification method.

  20. Efficient identification of critical residues based only on protein structure by network analysis.

    Directory of Open Access Journals (Sweden)

    Michael P Cusack

    2007-05-01

    Full Text Available Despite the increasing number of published protein structures, and the fact that each protein's function relies on its three-dimensional structure, there is limited access to automatic programs used for the identification of critical residues from the protein structure, compared with those based on protein sequence. Here we present a new algorithm based on network analysis applied exclusively on protein structures to identify critical residues. Our results show that this method identifies critical residues for protein function with high reliability and improves automatic sequence-based approaches and previous network-based approaches. The reliability of the method depends on the conformational diversity screened for the protein of interest. We have designed a web site to give access to this software at http://bis.ifc.unam.mx/jamming/. In summary, a new method is presented that relates critical residues for protein function with the most traversed residues in networks derived from protein structures. A unique feature of the method is the inclusion of the conformational diversity of proteins in the prediction, thus reproducing a basic feature of the structure/function relationship of proteins.

  1. Identification and Structural Characterization of Unidentified Impurity in Bisoprolol Film-Coated Tablets

    Directory of Open Access Journals (Sweden)

    Ivana Mitrevska

    2017-01-01

    Full Text Available The aim of this study is the identification, structural characterization, and qualification of a degradation impurity of bisoprolol labeled as Impurity RRT 0.95. This degradation product is considered as a principal thermal degradation impurity identified in bisoprolol film-coated tablets. The impurity has been observed in the stress thermal degradation study of the drug product. Using HPLC/DAD/ESI-MS method, a tentative structure was assigned and afterwards confirmed by detailed structural characterization using NMR spectroscopy. The structure of the target Impurity RRT 0.95 was elucidated as phosphomonoester of bisoprolol, having relative molecular mass of 406 (positive ionization mode. The structural characterization was followed by qualification of Impurity RRT 0.95 using several different in silico methodologies. From the results obtained, it can be concluded that no new structural alerts have been generated for Impurity RRT 0.95 relative to the parent compound bisoprolol. The current study presents an in-depth analysis of the full characterization and qualification of an unidentified impurity in a drug product with the purpose of properly defining the quality specification of the product.

  2. Experimental verifications of a structural damage identification technique using reduced order finite-element model

    Science.gov (United States)

    Li, Rui; Zhou, Li; Yang, Jann N.

    2010-04-01

    An objective of the structural health monitoring system is to identify the state of the structure and to detect the damage when it occurs. Analysis techniques for the damage identification of structures, based on vibration data measured from sensors, have received considerable attention. Recently, a new damage tracking technique, referred to as the adaptive quadratic sum-square error (AQSSE) technique, has been proposed, and simulation studies demonstrated that the AQSSE technique is quite effective in identifying structural damages. In this paper, the adaptive quadratic sumsquare error (AQSSE) along with the reduced-order finite-element method is proposed to identify the damages of complex structures. Experimental tests were conducted to verify the capability of the proposed damage detection approach. A series of experimental tests were performed using a scaled cantilever beam subject to the white noise and sinusoidal excitations. The capability of the proposed reduced-order finite-element based adaptive quadratic sum-square error (AQSSE) method in detecting the structural damage is demonstrated by the experimental results.

  3. Structural damage identification using damping: a compendium of uses and features

    Science.gov (United States)

    Cao, M. S.; Sha, G. G.; Gao, Y. F.; Ostachowicz, W.

    2017-04-01

    The vibration responses of structures under controlled or ambient excitation can be used to detect structural damage by correlating changes in structural dynamic properties extracted from responses with damage. Typical dynamic properties refer to modal parameters: natural frequencies, mode shapes, and damping. Among these parameters, natural frequencies and mode shapes have been investigated extensively for their use in damage characterization by associating damage with reduction in local stiffness of structures. In contrast, the use of damping as a dynamic property to represent structural damage has not been comprehensively elucidated, primarily due to the complexities of damping measurement and analysis. With advances in measurement technologies and analysis tools, the use of damping to identify damage is becoming a focus of increasing attention in the damage detection community. Recently, a number of studies have demonstrated that damping has greater sensitivity for characterizing damage than natural frequencies and mode shapes in various applications, but damping-based damage identification is still a research direction ‘in progress’ and is not yet well resolved. This situation calls for an overall survey of the state-of-the-art and the state-of-the-practice of using damping to detect structural damage. To this end, this study aims to provide a comprehensive survey of uses and features of applying damping in structural damage detection. First, we present various methods for damping estimation in different domains including the time domain, the frequency domain, and the time-frequency domain. Second, we investigate the features and applications of damping-based damage detection methods on the basis of two predominant infrastructure elements, reinforced concrete structures and fiber-reinforced composites. Third, we clarify the influential factors that can impair the capability of damping to characterize damage. Finally, we recommend future research directions

  4. Prediction of drug-related cardiac adverse effects in humans--A: creation of a database of effects and identification of factors affecting their occurrence.

    Science.gov (United States)

    Matthews, Edwin J; Frid, Anna A

    2010-04-01

    This is the first of two reports that describes the compilation of a database of drug-related cardiac adverse effects (AEs) that was used to construct quantitative structure-activity relationship (QSAR) models to predict these AEs, to identify properties of pharmaceuticals correlated with the AEs, and to identify plausible mechanisms of action (MOAs) causing the AEs. This database of 396,985 cardiac AE reports was linked to 1632 approved drugs and their chemical structures, 1851 clinical indications (CIs), 997 therapeutic targets (TTs), 432 pharmacological MOAs, and 21,180 affinity coefficients (ACs) for the MOA receptors. AEs were obtained from the Food and Drug Administration's (FDA's) Spontaneous Reporting System (SRS) and Adverse Event Reporting System (AERS) and publicly available medical literature. Drug TTs were obtained from Integrity; drug MOAs and ACs were predicted by BioEpisteme. Significant cardiac AEs and patient exposures were estimated based on the proportional reporting ratios (PRRs) for each drug and each AE endpoint as a percentage of the total AEs. Cardiac AE endpoints were bundled based on toxicological mechanism and concordance of drug-related findings. Results revealed that significant cardiac AEs formed 9 clusters affecting Purkinje nerve fibers (arrhythmia, bradycardia, conduction disorder, electrocardiogram, palpitations, QT prolongation, rate rhythm composite, tachycardia, and Torsades de pointes), and 5 clusters affecting the heart muscle (coronary artery disorders, heart failure, myocardial disorders, myocardial infarction, and valve disorders). Based on the observation that each drug had one TT and up to 9 off-target MOAs, cardiac AEs were highly correlated with drugs affecting cardiovascular and cardioneurological functions and certain MOAs (e.g., alpha- and beta-adeno, dopamine, and hydroxytryptomine receptors). Copyright 2010. Published by Elsevier Inc.

  5. ODEion--a software module for structural identification of ordinary differential equations.

    Science.gov (United States)

    Gennemark, Peter; Wedelin, Dag

    2014-02-01

    In the systems biology field, algorithms for structural identification of ordinary differential equations (ODEs) have mainly focused on fixed model spaces like S-systems and/or on methods that require sufficiently good data so that derivatives can be accurately estimated. There is therefore a lack of methods and software that can handle more general models and realistic data. We present ODEion, a software module for structural identification of ODEs. Main characteristic features of the software are: • The model space is defined by arbitrary user-defined functions that can be nonlinear in both variables and parameters, such as for example chemical rate reactions. • ODEion implements computationally efficient algorithms that have been shown to efficiently handle sparse and noisy data. It can run a range of realistic problems that previously required a supercomputer. • ODEion is easy to use and provides SBML output. We describe the mathematical problem, the ODEion system itself, and provide several examples of how the system can be used. Available at: http://www.odeidentification.org.

  6. Structural damage identification in wind turbine blades using piezoelectric active sensing with ultrasonic validation

    Energy Technology Data Exchange (ETDEWEB)

    Claytor, Thomas N [Los Alamos National Laboratory; Ammerman, Curtt N [Los Alamos National Laboratory; Park, Gyu Hae [Los Alamos National Laboratory; Farinholt, Kevin M [Los Alamos National Laboratory; Farrar, Charles R [Los Alamos National Laboratory; Atterbury, Marie K [Los Alamos National Laboratory

    2010-01-01

    This paper gives a brief overview of a new project at LANL in structural damage identification for wind turbines. This project makes use of modeling capabilities and sensing technology to understand realistic blade loading on large turbine blades, with the goal of developing the technology needed to automatically detect early damage. Several structural health monitoring (SHM) techniques using piezoelectric active materials are being investigated for the development of wireless, low power sensors that interrogate sections of the wind turbine blade using Lamb wave propagation data, frequency response functions (FRFs), and time-series analysis methods. The modeling and sensor research will be compared with extensive experimental testing, including wind tunnel experiments, load and fatigue tests, and ultrasonic scans - on small- to mid-scale turbine blades. Furthermore, this study will investigate the effect of local damage on the global response of the blade by monitoring low-frequency response changes.

  7. Identification and comparison of structural factors of innovation capability in ESCO with desirable status

    Directory of Open Access Journals (Sweden)

    Fatemeh Jalali

    2014-12-01

    Full Text Available The present study describes the identification and comparison of structural factors of innovation capability in Esfahan Steel Company (ESCO. Innovation is a crucial factor in growth, success, and survival of organizations. Since the innovation for organizations is not possible without the level of innovation capabilities and the need for steel products and imports of goods from developed countries has greatly increased, this study intends to investigate the factors affecting the subject that may be able to increase the production and reduce the need to import it. Evaluation of the innovation capability factors of ESCO compared with its desired status in industry can help companies develop innovative strategies and also achieve organizational goals. Statistical analysis methods and mean comparison test by examining the structure of the innovation capability in the form of a standard questionnaire was employed. The findings suggest that the innovation capability in the existing situation of ESCO in comparison with the desired situation is significantly different.

  8. Structural damage detection based on stochastic subspace identification and statistical pattern recognition: I. Theory

    Science.gov (United States)

    Ren, W. X.; Lin, Y. Q.; Fang, S. E.

    2011-11-01

    One of the key issues in vibration-based structural health monitoring is to extract the damage-sensitive but environment-insensitive features from sampled dynamic response measurements and to carry out the statistical analysis of these features for structural damage detection. A new damage feature is proposed in this paper by using the system matrices of the forward innovation model based on the covariance-driven stochastic subspace identification of a vibrating system. To overcome the variations of the system matrices, a non-singularity transposition matrix is introduced so that the system matrices are normalized to their standard forms. For reducing the effects of modeling errors, noise and environmental variations on measured structural responses, a statistical pattern recognition paradigm is incorporated into the proposed method. The Mahalanobis and Euclidean distance decision functions of the damage feature vector are adopted by defining a statistics-based damage index. The proposed structural damage detection method is verified against one numerical signal and two numerical beams. It is demonstrated that the proposed statistics-based damage index is sensitive to damage and shows some robustness to the noise and false estimation of the system ranks. The method is capable of locating damage of the beam structures under different types of excitations. The robustness of the proposed damage detection method to the variations in environmental temperature is further validated in a companion paper by a reinforced concrete beam tested in the laboratory and a full-scale arch bridge tested in the field.

  9. Computer-aided structure analysis. Structure identification by infrared and /sup 13/C NMR measurements

    Energy Technology Data Exchange (ETDEWEB)

    Szalontai, G; Simon, Z; Csapo, Z; Farkas, M; Pfeifer, Gy [Nehezvegyipari Kutato Intezet, Veszprem (Hungary)

    1980-01-01

    The results obtained from the computer-aided interpretation of /sup 13/C NMR and IR spectra using the artificial intelligence approach are presented. In its present state the output of the system is a list of functional groups which are resonable candidates for the final structural isomers. The input requires empirical formula, /sup 13/C NMR data (off resonance data also) and IR spectral data. The confirmation of the presence of a functional group is based on comparison of the experimental data with the spectral properties of functional groups stored in a property matrix. If the molecular weight of the compounds studied is less or equal 500, the output contains usually 1.5-2.5 times more groups than really present, in most cases without the loss of the real ones.

  10. Occurrence, diversity and community structure of culturable atrazine degraders in industrial and agricultural soils exposed to the herbicide in Shandong Province, P.R. China.

    Science.gov (United States)

    Bazhanov, Dmitry P; Li, Chengyun; Li, Hongmei; Li, Jishun; Zhang, Xinjian; Chen, Xiangfeng; Yang, Hetong

    2016-11-08

    Soil populations of bacteria rapidly degrading atrazine are critical to the environmental fate of the herbicide. An enrichment bias from the routine isolation procedure prevents studying the diversity of atrazine degraders. In the present work, we analyzed the occurrence, diversity and community structure of soil atrazine-degrading bacteria based on their direct isolation. Atrazine-degrading bacteria were isolated by direct plating on a specially developed SM agar. The atrazine degradation genes trzN and atzABC were detected by multiplex PCR. The diversity of atrazine degraders was characterized by enterobacterial repetitive intergenic consensus-PCR (ERIC-PCR) genotyping followed by 16S rRNA gene phylogenetic analysis. The occurrence of atrazine-degrading bacteria was also assessed by conventional PCR targeting trzN and atzABC in soil DNA. A total of 116 atrazine-degrading isolates were recovered from bulk and rhizosphere soils sampled near an atrazine factory and from geographically distant maize fields. Fifteen genotypes were distinguished among 56 industrial isolates, with 13 of them representing eight phylogenetic groups of the genus Arthrobacter. The remaining two were closely related to Pseudomonas alcaliphila and Gulosibacter molinativorax and constituted major components of the atrazine-degrading community in the most heavily contaminated industrial plantless soil. All isolates from the adjacent sites inhabited by cogon grass or common reed were various Arthrobacter spp. with a strong prevalence of A. aurescens group. Only three genotypes were distinguished among 60 agricultural strains. Genetically similar Arthrobacter ureafaciens bacteria which occurred as minor inhabitants of cogon grass roots in the industrial soil were ubiquitous and predominant atrazine degraders in the maize rhizosphere. The other two genotypes represented two distant Nocardioides spp. that were specific to their geographic origins. Direct plating on SM agar enabled rapid isolation

  11. Vascular Structure Identification in Intraoperative 3D Contrast-Enhanced Ultrasound Data

    Directory of Open Access Journals (Sweden)

    Elisee Ilunga-Mbuyamba

    2016-04-01

    Full Text Available In this paper, a method of vascular structure identification in intraoperative 3D Contrast-Enhanced Ultrasound (CEUS data is presented. Ultrasound imaging is commonly used in brain tumor surgery to investigate in real time the current status of cerebral structures. The use of an ultrasound contrast agent enables to highlight tumor tissue, but also surrounding blood vessels. However, these structures can be used as landmarks to estimate and correct the brain shift. This work proposes an alternative method for extracting small vascular segments close to the tumor as landmark. The patient image dataset involved in brain tumor operations includes preoperative contrast T1MR (cT1MR data and 3D intraoperative contrast enhanced ultrasound data acquired before (3D-iCEUS s t a r t and after (3D-iCEUS e n d tumor resection. Based on rigid registration techniques, a preselected vascular segment in cT1MR is searched in 3D-iCEUS s t a r t and 3D-iCEUS e n d data. The method was validated by using three similarity measures (Normalized Gradient Field, Normalized Mutual Information and Normalized Cross Correlation. Tests were performed on data obtained from ten patients overcoming a brain tumor operation and it succeeded in nine cases. Despite the small size of the vascular structures, the artifacts in the ultrasound images and the brain tissue deformations, blood vessels were successfully identified.

  12. Repetitive Identification of Structural Systems Using a Nonlinear Model Parameter Refinement Approach

    Directory of Open Access Journals (Sweden)

    Jeng-Wen Lin

    2009-01-01

    Full Text Available This paper proposes a statistical confidence interval based nonlinear model parameter refinement approach for the health monitoring of structural systems subjected to seismic excitations. The developed model refinement approach uses the 95% confidence interval of the estimated structural parameters to determine their statistical significance in a least-squares regression setting. When the parameters' confidence interval covers the zero value, it is statistically sustainable to truncate such parameters. The remaining parameters will repetitively undergo such parameter sifting process for model refinement until all the parameters' statistical significance cannot be further improved. This newly developed model refinement approach is implemented for the series models of multivariable polynomial expansions: the linear, the Taylor series, and the power series model, leading to a more accurate identification as well as a more controllable design for system vibration control. Because the statistical regression based model refinement approach is intrinsically used to process a “batch” of data and obtain an ensemble average estimation such as the structural stiffness, the Kalman filter and one of its extended versions is introduced to the refined power series model for structural health monitoring.

  13. Topology optimization of continuum structure with dynamic constraints using mode identification

    International Nuclear Information System (INIS)

    Li, Jianhongyu; Chen, Shenyan; Huang, Hai

    2015-01-01

    For the problems such as mode exchange and localized modes in topology optimization of continuum structure with dynamic constraints, it is difficult to apply the traditional optimization model which considers fixed order mode frequencies as constraints in optimization calculation. A new optimization model is established, in which the dynamical constraints are changed as frequencies of structural principal vibrations. The order of the principal vibrations is recognized through modal identification in the optimization process, and the constraints are updated to make the optimization calculation execute smoothly. Localized mode elimination techniques are introduced to reduce the localized modes induced by the low density elements, which could improve the optimization efficiency. A new optimization process is designed, which achieves the purpose of overcoming mode exchange problem and localized mode problem at the cost of increasing several structural analyses. Optimization system is developed by using Nastran to perform structural analysis and sensitivity analysis and two-level multipoint approximation algorithm as optimizer. Numerical results verified that the presented method is effective and reasonable.

  14. Identification of a novel structure in heparin generated by potassium permanganate oxidation

    Science.gov (United States)

    Beccati, Daniela; Roy, Sucharita; Yu, Fei; Gunay, Nur Sibel; Capila, Ishan; Lech, Miroslaw; Linhardt, Robert J.; Venkataraman, Ganesh

    2012-01-01

    The worldwide heparin contamination crisis in 2008 led health authorities to take fundamental steps to better control heparin manufacture, including implementing appropriate analytical and bio-analytical methods to ensure production and release of high quality heparin sodium product. Consequently, there is an increased interest in the identification and structural elucidation of unusually modified structures that may be present in heparin. Our study focuses on the structural elucidation of species that give rise to a signal observed at 2.10 ppm in the N-acetyl region of the 1H NMR spectrum of some pharmaceutical grade heparin preparations. Structural elucidation experiments were carried out using homonuclear (COSY, TOSCY and NOESY) and heteronuclear (HSQC, HSQC-DEPT, HMQC-COSY, HSQC-TOCSY, and HMBC) 2D NMR spectroscopy on both heparin as well as heparin-like model compounds. Our results identify a novel type of oxidative modification of the heparin chain that results from a specific step in the manufacturing process used to prepare heparin. PMID:25147414

  15. Identification of a Herbal Powder by Deoxyribonucleic Acid Barcoding and Structural Analyses.

    Science.gov (United States)

    Sheth, Bhavisha P; Thaker, Vrinda S

    2015-10-01

    Authentic identification of plants is essential for exploiting their medicinal properties as well as to stop the adulteration and malpractices with the trade of the same. To identify a herbal powder obtained from a herbalist in the local vicinity of Rajkot, Gujarat, using deoxyribonucleic acid (DNA) barcoding and molecular tools. The DNA was extracted from a herbal powder and selected Cassia species, followed by the polymerase chain reaction (PCR) and sequencing of the rbcL barcode locus. Thereafter the sequences were subjected to National Center for Biotechnology Information (NCBI) basic local alignment search tool (BLAST) analysis, followed by the protein three-dimension structure determination of the rbcL protein from the herbal powder and Cassia species namely Cassia fistula, Cassia tora and Cassia javanica (sequences obtained in the present study), Cassia Roxburghii, and Cassia abbreviata (sequences retrieved from Genbank). Further, the multiple and pairwise structural alignment were carried out in order to identify the herbal powder. The nucleotide sequences obtained from the selected species of Cassia were submitted to Genbank (Accession No. JX141397, JX141405, JX141420). The NCBI BLAST analysis of the rbcL protein from the herbal powder showed an equal sequence similarity (with reference to different parameters like E value, maximum identity, total score, query coverage) to C. javanica and C. roxburghii. In order to solve the ambiguities of the BLAST result, a protein structural approach was implemented. The protein homology models obtained in the present study were submitted to the protein model database (PM0079748-PM0079753). The pairwise structural alignment of the herbal powder (as template) and C. javanica and C. roxburghii (as targets individually) revealed a close similarity of the herbal powder with C. javanica. A strategy as used here, incorporating the integrated use of DNA barcoding and protein structural analyses could be adopted, as a novel

  16. A practical guide for the identification of major sulcogyral structures of the human cortex.

    Science.gov (United States)

    Destrieux, Christophe; Terrier, Louis Marie; Andersson, Frédéric; Love, Scott A; Cottier, Jean-Philippe; Duvernoy, Henri; Velut, Stéphane; Janot, Kevin; Zemmoura, Ilyess

    2017-05-01

    The precise sulcogyral localization of cortical lesions is mandatory to improve communication between practitioners and to predict and prevent post-operative deficits. This process, which assumes a good knowledge of the cortex anatomy and a systematic analysis of images, is, nevertheless, sometimes neglected in the neurological and neurosurgical training. This didactic paper proposes a brief overview of the sulcogyral anatomy, using conventional MR-slices, and also reconstructions of the cortical surface after a more or less extended inflation process. This method simplifies the cortical anatomy by removing part of the cortical complexity induced by the folding process, and makes it more understandable. We then reviewed several methods for localizing cortical structures, and proposed a three-step identification: after localizing the lateral, medial or ventro-basal aspect of the hemisphere (step 1), the main interlobar sulci were located to limit the lobes (step 2). Finally, intralobar sulci and gyri were identified (step 3) thanks to the same set of rules. This paper does not propose any new identification method but should be regarded as a set of practical guidelines, useful in daily clinical practice, for detecting the main sulci and gyri of the human cortex.

  17. Review of Radio Frequency Identification and Wireless Technology for Structural Health Monitoring

    International Nuclear Information System (INIS)

    Dhital, Dipesh; Chia, Chen Ciang; Lee, Jung Ryul; Park, Chan Yik

    2010-01-01

    Radio frequency identification(RFID) combined with wireless technology has good potential for structural health monitoring(SHM). We describe several advantages of RFID and wireless technologies for SHM, and review SHM examples with working principles, design and technical details for damage detection, heat exposure monitoring, force/strain sensing, and corrosion detection in concrete, steel, carbon fiber reinforced polymer(CFRP), and other materials. Various sensors combined with wireless communication are also discussed. These methodologies can be readily developed, implemented, and customized. There are some technical difficulties, but solutions are being addressed. Lastly, a surface acoustic wave-based RFID system is presented, and possible future trends of SHM based on RFID and wireless technology are presented

  18. Review of Radio Frequency Identification and Wireless Technology for Structural Health Monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Dhital, Dipesh; Chia, Chen Ciang; Lee, Jung Ryul [Chonbuk National University, Jeonju (Korea, Republic of); Park, Chan Yik [Aeronautical Technology Directorate, Agency for Defense Development, Daejeon (Korea, Republic of)

    2010-06-15

    Radio frequency identification(RFID) combined with wireless technology has good potential for structural health monitoring(SHM). We describe several advantages of RFID and wireless technologies for SHM, and review SHM examples with working principles, design and technical details for damage detection, heat exposure monitoring, force/strain sensing, and corrosion detection in concrete, steel, carbon fiber reinforced polymer(CFRP), and other materials. Various sensors combined with wireless communication are also discussed. These methodologies can be readily developed, implemented, and customized. There are some technical difficulties, but solutions are being addressed. Lastly, a surface acoustic wave-based RFID system is presented, and possible future trends of SHM based on RFID and wireless technology are presented

  19. Identification of PAH Isomeric Structure in Cosmic Dust Analogs: The AROMA Setup

    Energy Technology Data Exchange (ETDEWEB)

    Sabbah, Hassan; Bonnamy, Anthony; Joblin, Christine [Université de Toulouse, UPS-OMP, Institut de Recherche en Astrophysique et Planétologie, 9 avenue du Colonel Roche, 31028 Toulouse Cedex 4 (France); Papanastasiou, Dimitris [Fasmatech Science + Technology, Athens, GR (Greece); Cernicharo, Jose; Martín-Gago, Jose-Angel, E-mail: christine.joblin@irap.omp.eu [Instituto de Ciencia de Materiales de Madrid, Sor Juana Inés de la Cruz, 3, Cantoblanco, E-28049 Madrid (Spain)

    2017-07-01

    We developed a new analytical experimental setup called AROMA (Astrochemistry Research of Organics with Molecular Analyzer) that combines laser desorption/ionization techniques with ion trap mass spectrometry. We report here on the ability of the apparatus to detect aromatic species in complex materials of astrophysical interest and characterize their structures. A limit of detection of 100 femto-grams has been achieved using pure polycyclic aromatic hydrocarbon (PAH) samples, which corresponds to 2 × 10{sup 8} molecules in the case of coronene (C{sub 24}H{sub 12}). We detected the PAH distribution in the Murchison meteorite, which is made of a complex mixture of extraterrestrial organic compounds. In addition, collision induced dissociation experiments were performed on selected species detected in Murchison, which led to the first firm identification of pyrene and its methylated derivatives in this sample.

  20. Rational identification of aggregation hotspots based on secondary structure and amino acid hydrophobicity.

    Science.gov (United States)

    Matsui, Daisuke; Nakano, Shogo; Dadashipour, Mohammad; Asano, Yasuhisa

    2017-08-25

    Insolubility of proteins expressed in the Escherichia coli expression system hinders the progress of both basic and applied research. Insoluble proteins contain residues that decrease their solubility (aggregation hotspots). Mutating these hotspots to optimal amino acids is expected to improve protein solubility. To date, however, the identification of these hotspots has proven difficult. In this study, using a combination of approaches involving directed evolution and primary sequence analysis, we found two rules to help inductively identify hotspots: the α-helix rule, which focuses on the hydrophobicity of amino acids in the α-helix structure, and the hydropathy contradiction rule, which focuses on the difference in hydrophobicity relative to the corresponding amino acid in the consensus protein. By properly applying these two rules, we succeeded in improving the probability that expressed proteins would be soluble. Our methods should facilitate research on various insoluble proteins that were previously difficult to study due to their low solubility.

  1. Identification of AI-2 Quorum Sensing Inhibitors in Vibrio harveyi Through Structure-Based Virtual Screening.

    Science.gov (United States)

    Jiang, Tianyu; Zhu, Peng; Du, Lupei; Li, Minyong

    2018-01-01

    Quorum sensing (QS) is a cell-to-cell communication system that regulates gene expression as a result of the production and perception of signal molecules called autoinducers (AIs). AI-2 is a QS autoinducer produced by both Gram-negative and Gram-positive bacteria, in which it regulates intraspecies and interspecies communication. The identification of QS inhibitors is considered a promising strategy for the development of anti-virulence drugs with reduced selective pressure for resistance. Here we describe a high-throughput virtual screening approach to identify AI-2 quorum sensing inhibitors on the basis of Vibrio harveyi LuxPQ crystal structure. Seven potent inhibitors with IC 50 values in the micromolar range were selected with no effect or low effect on V. harveyi growth rate.

  2. Accuracy of Parent Identification of Stuttering Occurrence

    Science.gov (United States)

    Einarsdottir, Johanna; Ingham, Roger

    2009-01-01

    Background: Clinicians rely on parents to provide information regarding the onset and development of stuttering in their own children. The accuracy and reliability of their judgments of stuttering is therefore important and is not well researched. Aim: To investigate the accuracy of parent judgements of stuttering in their own children's speech…

  3. Occurrence, isolation and DNA identification of Streptococcus ...

    African Journals Online (AJOL)

    ajl yemi

    2011-11-28

    Nov 28, 2011 ... Streptococcus thermophilus involved in Algerian ... among reference, and wild strains of S. thermophilus and for their differentiation from Enterococcus spp. ..... Isolation and characterization of Lactobacillus delbrueckii ssp.

  4. Nonlinear dynamic systems identification using recurrent interval type-2 TSK fuzzy neural network - A novel structure.

    Science.gov (United States)

    El-Nagar, Ahmad M

    2018-01-01

    In this study, a novel structure of a recurrent interval type-2 Takagi-Sugeno-Kang (TSK) fuzzy neural network (FNN) is introduced for nonlinear dynamic and time-varying systems identification. It combines the type-2 fuzzy sets (T2FSs) and a recurrent FNN to avoid the data uncertainties. The fuzzy firing strengths in the proposed structure are returned to the network input as internal variables. The interval type-2 fuzzy sets (IT2FSs) is used to describe the antecedent part for each rule while the consequent part is a TSK-type, which is a linear function of the internal variables and the external inputs with interval weights. All the type-2 fuzzy rules for the proposed RIT2TSKFNN are learned on-line based on structure and parameter learning, which are performed using the type-2 fuzzy clustering. The antecedent and consequent parameters of the proposed RIT2TSKFNN are updated based on the Lyapunov function to achieve network stability. The obtained results indicate that our proposed network has a small root mean square error (RMSE) and a small integral of square error (ISE) with a small number of rules and a small computation time compared with other type-2 FNNs. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  5. RadCon Occurrence Reporting Simplified

    International Nuclear Information System (INIS)

    Denham, D. H.

    1999-01-01

    This narrative and accompanying diagrams provide a simplified summary of the RadCon Occurrence Reporting criteria to allow Environmental Restoration Contractor (ERC) staff to efficiently recognize occurrences and to effectively initiate the implementation of the requirements of U.S. Department of Energy (DOE) Order 232.1A, Occurrence Reporting and Processing of Operations Information, and of the ERC criteria defined in BHI-MA-02, ERC Project Procedures, Procedure 2.6, ''Occurrence Investigation and Reporting.'' These directives promote timely identification, categorization, notification, and reporting to DOE and ERC management of reportable occurrences at DOE-owned or -operated facilities that could (1) affect health and safety of the public, (2) seriously impact the intended purpose of DOE facilities, (3) adversely affect the credibility of DOE, or (4) have a noticeable adverse effect on the environment

  6. Evaluation of Different Methods for Identification of Structural Alerts Using Chemical Ames Mutagenicity Data Set as a Benchmark.

    Science.gov (United States)

    Yang, Hongbin; Li, Jie; Wu, Zengrui; Li, Weihua; Liu, Guixia; Tang, Yun

    2017-06-19

    Identification of structural alerts for toxicity is useful in drug discovery and other fields such as environmental protection. With structural alerts, researchers can quickly identify potential toxic compounds and learn how to modify them. Hence, it is important to determine structural alerts from a large number of compounds quickly and accurately. There are already many methods reported for identification of structural alerts. However, how to evaluate those methods is a problem. In this paper, we tried to evaluate four of the methods for monosubstructure identification with three indices including accuracy rate, coverage rate, and information gain to compare their advantages and disadvantages. The Kazius' Ames mutagenicity data set was used as the benchmark, and the four methods were MoSS (graph-based), SARpy (fragment-based), and two fingerprint-based methods including Bioalerts and the fingerprint (FP) method we previously used. The results showed that Bioalerts and FP could detect key substructures with high accuracy and coverage rates because they allowed unclosed rings and wildcard atom or bond types. However, they also resulted in redundancy so that their predictive performance was not as good as that of SARpy. SARpy was competitive in predictive performance in both training set and external validation set. These results might be helpful for users to select appropriate methods and further development of methods for identification of structural alerts.

  7. Experimental system identification of the dynamics of a vibro-impact beam with a view towards structural health monitoring and damage detection

    Science.gov (United States)

    Chen, Heng; Kurt, Mehmet; Lee, Young S.; McFarland, D. Michael; Bergman, Lawrence A.; Vakakis, Alexander F.

    2014-05-01

    We perform nonlinear system identification (NSI) on the acceleration signals that were experimentally measured at ten, almost evenly spaced positions along a cantilever beam undergoing vibro-impacts between two rigid stops with clearances. Our goal is to characterize the nonlinear dynamics due to vibro-impacts with a view toward structural health monitoring (SHM) and damage detection (DD). The NSI methodology is based on the correspondence between analytical and empirical slow-flow dynamics, with the first step requiring empirical mode decomposition (EMD) analysis of the measured time series leading to sets of intrinsic modal oscillators (IMOs) governing the vibro-impact dynamics at different time scales. By comparing the spatiotemporal variations of the nonlinear modal interactions (and hence the IMOs), we examine how vibro-impacts influence the low- and high-frequency modes in global and local senses. In applications of the NSI results to SHM/DD, we calculate typical measures such as the modal assurance criterion (MAC) and the coordinate modal assurance criterion (COMAC) by extracting information about the mode shape functions from the spatiotemporal IMO solutions. Whereas the MAC provides a global aspect of damage occurrence (i.e., which modes are more affected by induced defects), the COMAC can narrow down the damage locations (i.e., where in the structure defects exist that yield low correlation values in specific modes).

  8. Identification of moving vehicle forces on bridge structures via moving average Tikhonov regularization

    Science.gov (United States)

    Pan, Chu-Dong; Yu, Ling; Liu, Huan-Lin

    2017-08-01

    Traffic-induced moving force identification (MFI) is a typical inverse problem in the field of bridge structural health monitoring. Lots of regularization-based methods have been proposed for MFI. However, the MFI accuracy obtained from the existing methods is low when the moving forces enter into and exit a bridge deck due to low sensitivity of structural responses to the forces at these zones. To overcome this shortcoming, a novel moving average Tikhonov regularization method is proposed for MFI by combining with the moving average concepts. Firstly, the bridge-vehicle interaction moving force is assumed as a discrete finite signal with stable average value (DFS-SAV). Secondly, the reasonable signal feature of DFS-SAV is quantified and introduced for improving the penalty function (∣∣x∣∣2 2) defined in the classical Tikhonov regularization. Then, a feasible two-step strategy is proposed for selecting regularization parameter and balance coefficient defined in the improved penalty function. Finally, both numerical simulations on a simply-supported beam and laboratory experiments on a hollow tube beam are performed for assessing the accuracy and the feasibility of the proposed method. The illustrated results show that the moving forces can be accurately identified with a strong robustness. Some related issues, such as selection of moving window length, effect of different penalty functions, and effect of different car speeds, are discussed as well.

  9. Identification of individual coherent sets associated with flow trajectories using Coherent Structure Coloring

    Science.gov (United States)

    Schlueter-Kuck, Kristy; Dabiri, John

    2017-11-01

    In recent years, there has been a proliferation of techniques that aim to characterize fluid flow kinematics on the basis of Lagrangian trajectories of collections of tracer particles. Most of these techniques depend on presence of tracer particles that are initially closely-spaced, in order to compute local gradients of their trajectories. In many applications, the requirement of close tracer spacing cannot be satisfied, especially when the tracers are naturally occurring and their distribution is dictated by the underlying flow. Moreover, current methods often focus on determination of the boundaries of coherent sets, whereas in practice it is often valuable to identify the complete set of trajectories that are coherent with an individual trajectory of interest. We extend the concept of Coherent Structure Coloring to achieve identification of the coherent set associated with individual Lagrangian trajectories. This algorithm is proven successful in identifying coherent structures of varying complexities in canonical unsteady flows. Importantly, although the method is demonstrated here in the context of fluid flow kinematics, the generality of the approach allows for its potential application to other unsupervised clustering problems in dynamical systems. This work was supported by the Department of Defense (DoD) through the National Defense Science & Engineering Graduate Fellowship (NDSEG) Program.

  10. A simple iterative independent component analysis algorithm for vibration source signal identification of complex structures

    Directory of Open Access Journals (Sweden)

    Dong-Sup Lee

    2015-01-01

    Full Text Available Independent Component Analysis (ICA, one of the blind source separation methods, can be applied for extracting unknown source signals only from received signals. This is accomplished by finding statistical independence of signal mixtures and has been successfully applied to myriad fields such as medical science, image processing, and numerous others. Nevertheless, there are inherent problems that have been reported when using this technique: insta- bility and invalid ordering of separated signals, particularly when using a conventional ICA technique in vibratory source signal identification of complex structures. In this study, a simple iterative algorithm of the conventional ICA has been proposed to mitigate these problems. The proposed method to extract more stable source signals having valid order includes an iterative and reordering process of extracted mixing matrix to reconstruct finally converged source signals, referring to the magnitudes of correlation coefficients between the intermediately separated signals and the signals measured on or nearby sources. In order to review the problems of the conventional ICA technique and to vali- date the proposed method, numerical analyses have been carried out for a virtual response model and a 30 m class submarine model. Moreover, in order to investigate applicability of the proposed method to real problem of complex structure, an experiment has been carried out for a scaled submarine mockup. The results show that the proposed method could resolve the inherent problems of a conventional ICA technique.

  11. Identification of Enzyme Genes Using Chemical Structure Alignments of Substrate-Product Pairs.

    Science.gov (United States)

    Moriya, Yuki; Yamada, Takuji; Okuda, Shujiro; Nakagawa, Zenichi; Kotera, Masaaki; Tokimatsu, Toshiaki; Kanehisa, Minoru; Goto, Susumu

    2016-03-28

    Although there are several databases that contain data on many metabolites and reactions in biochemical pathways, there is still a big gap in the numbers between experimentally identified enzymes and metabolites. It is supposed that many catalytic enzyme genes are still unknown. Although there are previous studies that estimate the number of candidate enzyme genes, these studies required some additional information aside from the structures of metabolites such as gene expression and order in the genome. In this study, we developed a novel method to identify a candidate enzyme gene of a reaction using the chemical structures of the substrate-product pair (reactant pair). The proposed method is based on a search for similar reactant pairs in a reference database and offers ortholog groups that possibly mediate the given reaction. We applied the proposed method to two experimentally validated reactions. As a result, we confirmed that the histidine transaminase was correctly identified. Although our method could not directly identify the asparagine oxo-acid transaminase, we successfully found the paralog gene most similar to the correct enzyme gene. We also applied our method to infer candidate enzyme genes in the mesaconate pathway. The advantage of our method lies in the prediction of possible genes for orphan enzyme reactions where any associated gene sequences are not determined yet. We believe that this approach will facilitate experimental identification of genes for orphan enzymes.

  12. Proportioning whole-genome single-nucleotide-polymorphism diversity for the identification of geographic population structure and genetic ancestry

    NARCIS (Netherlands)

    O. Lao Grueso (Oscar); K. van Duijn (Kate); P. Kersbergen (Paula); P. de Knijff (Peter); M.H. Kayser (Manfred)

    2006-01-01

    textabstractThe identification of geographic population structure and genetic ancestry on the basis of a minimal set of genetic markers is desirable for a wide range of applications in medical and forensic sciences. However, the absence of sharp discontinuities in the neutral genetic diversity among

  13. Proportioning whole-genome single-nucleotide-polymorphism diversity for the identification of geographic population structure and genetic ancestry

    NARCIS (Netherlands)

    O. Lao Grueso (Oscar); K. van Duijn (Kate); P. Kersbergen; P. de Knijff (Peter); M.H. Kayser (Manfred)

    2006-01-01

    textabstractThe identification of geographic population structure and genetic ancestry on the basis of a minimal set of genetic markers is desirable for a wide range of applications in medical and forensic sciences. However, the absence of sharp discontinuities in the neutral

  14. Considerations in the identification of functional RNA structural elements in genomic alignments

    Directory of Open Access Journals (Sweden)

    Blencowe Benjamin J

    2007-01-01

    Full Text Available Abstract Background Accurate identification of novel, functional noncoding (nc RNA features in genome sequence has proven more difficult than for exons. Current algorithms identify and score potential RNA secondary structures on the basis of thermodynamic stability, conservation, and/or covariance in sequence alignments. Neither the algorithms nor the information gained from the individual inputs have been independently assessed. Furthermore, due to issues in modelling background signal, it has been difficult to gauge the precision of these algorithms on a genomic scale, in which even a seemingly small false-positive rate can result in a vast excess of false discoveries. Results We developed a shuffling algorithm, shuffle-pair.pl, that simultaneously preserves dinucleotide frequency, gaps, and local conservation in pairwise sequence alignments. We used shuffle-pair.pl to assess precision and recall of six ncRNA search tools (MSARI, QRNA, ddbRNA, RNAz, Evofold, and several variants of simple thermodynamic stability on a test set of 3046 alignments of known ncRNAs. Relative to mononucleotide shuffling, preservation of dinucleotide content in shuffling the alignments resulted in a drastic increase in estimated false-positive detection rates for ncRNA elements, precluding evaluation of higher order alignments, which cannot not be adequately shuffled maintaining both dinucleotides and alignment structure. On pairwise alignments, none of the covariance-based tools performed markedly better than thermodynamic scoring alone. Although the high false-positive rates call into question the veracity of any individual predicted secondary structural element in our analysis, we nevertheless identified intriguing global trends in human genome alignments. The distribution of ncRNA prediction scores in 75-base windows overlapping UTRs, introns, and intergenic regions analyzed using both thermodynamic stability and EvoFold (which has no thermodynamic component was

  15. Identification of glycan structure alterations on cell membrane proteins in desoxyepothilone B resistant leukemia cells.

    Science.gov (United States)

    Nakano, Miyako; Saldanha, Rohit; Göbel, Anja; Kavallaris, Maria; Packer, Nicolle H

    2011-11-01

    Resistance to tubulin-binding agents used in cancer is often multifactorial and can include changes in drug accumulation and modified expression of tubulin isotypes. Glycans on cell membrane proteins play important roles in many cellular processes such as recognition and apoptosis, and this study investigated whether changes to the glycan structures on cell membrane proteins occur when cells become resistant to drugs. Specifically, we investigated the alteration of glycan structures on the cell membrane proteins of human T-cell acute lymphoblastic leukemia (CEM) cells that were selected for resistance to desoxyepothilone B (CEM/dEpoB). The glycan profile of the cell membrane glycoproteins was obtained by sequential release of N- and O-glycans from cell membrane fraction dotted onto polyvinylidene difluoride membrane with PNGase F and β-elimination respectively. The released glycan alditols were analyzed by liquid chromatography (graphitized carbon)-electrospray ionization tandem MS. The major N-glycan on CEM cell was the core fucosylated α2-6 monosialo-biantennary structure. Resistant CEM/dEpoB cells had a significant decrease of α2-6 linked sialic acid on N-glycans. The lower α2-6 sialylation was caused by a decrease in activity of β-galactoside α2-6 sialyltransferase (ST6Gal), and decreased expression of the mRNA. It is clear that the membrane glycosylation of leukemia cells changes during acquired resistance to dEpoB drugs and that this change occurs globally on all cell membrane glycoproteins. This is the first identification of a specific glycan modification on the surface of drug resistant cells and the mechanism of this downstream effect on microtubule targeting drugs may offer a route to new interventions to overcome drug resistance.

  16. Mambertiite, BiMo"5"+_2_._8_0O_8(OH), a new mineral from Su Seinargiu, Sardinia, Italy: occurrence, crystal structure, and relationships with gelosaite

    International Nuclear Information System (INIS)

    Orlandi, Paolo; Biagioni, Cristian; Pasero, Marco; Merlino, Stefano; Demartin, Francesco; Campostrini, Italo

    2015-01-01

    Mambertiite, BiMo"5"+_2_._8_0O_8(OH), is a new mineral identified in small vugs of quartz veins from Su Seinargiu, Sarroch, Cagliari, Sardinia, Italy. It occurs as pale yellow {001} tabular crystals, up to 1 mm in length and few μm thick, with adamantine lustre. Mambertiite is brittle, with a conchoidal fracture. It is associated with ferrimolybdite, muscovite, quartz, sardignaite, and wulfenite. Electron microprobe data (wt% - mean of 12 spot analyses) are: Mo_2O_5 59.59, Bi_2O_3 36.96, WO_3 2.03, H_2O_c_a_l_c 1.48, sum 100.06. On the basis of 9 O atoms per formula unit, the empirical formula is Bi_0_._9_9(Mo"5"+_2_._7_4W_0_._0_5)_Σ_2_._7_9O_7_._9_7(OH)_1_._0_3. Infrared spectra showed absorption bands consistent with the occurrence of OH- groups. Mambertiite is triclinic, space group P1, with a = 5.854(2), b = 9.050(3), c = 7.637(3) Aa, α = 112.85(1), β = 102.58(1), γ = 90.04(1) , V = 362.3(2) Aa"3, Z = 2. The crystal structure of mambertiite was solved and refined down to R_1 = 0.050 on the basis of 2019 observed [F_o>4σ(F_o)] reflections. It is composed by eight-fold coordinated Bi-centred polyhedra and five independent Mo-centred octahedra. Among the latter, two are completely occupied by molybdenum, whereas the remaining three are only partially occupied. Two kinds of (10 anti 1) layers occur in mambertiite, alternating along [10 anti 1]*: one is composed by Bi-centered polyhedra and the two partially occupied Mo_4 and Mo_5 sites, whereas the other is composed by the zigzag chains, running along c, formed by the fully occupied Mo_1 and Mo_2 sites, and the partially occupied Mo_3 site. Mambertiite is structurally related to gelosaite, BiMo"6"+_2O_7(OH) . H_2O; their relationships can be conveniently described through the OD theory. Mambertiite is the fourth known mineral with Bi and Mo as essential components. Its name honours the Italian mineral collector Marzio Mamberti (b. 1959) for his contribution to the knowledge of the Sardinian mineralogy. The

  17. Identification of multiple distinct Snf2 subfamilies with conserved structural motifs.

    Science.gov (United States)

    Flaus, Andrew; Martin, David M A; Barton, Geoffrey J; Owen-Hughes, Tom

    2006-01-01

    The Snf2 family of helicase-related proteins includes the catalytic subunits of ATP-dependent chromatin remodelling complexes found in all eukaryotes. These act to regulate the structure and dynamic properties of chromatin and so influence a broad range of nuclear processes. We have exploited progress in genome sequencing to assemble a comprehensive catalogue of over 1300 Snf2 family members. Multiple sequence alignment of the helicase-related regions enables 24 distinct subfamilies to be identified, a considerable expansion over earlier surveys. Where information is known, there is a good correlation between biological or biochemical function and these assignments, suggesting Snf2 family motor domains are tuned for specific tasks. Scanning of complete genomes reveals all eukaryotes contain members of multiple subfamilies, whereas they are less common and not ubiquitous in eubacteria or archaea. The large sample of Snf2 proteins enables additional distinguishing conserved sequence blocks within the helicase-like motor to be identified. The establishment of a phylogeny for Snf2 proteins provides an opportunity to make informed assignments of function, and the identification of conserved motifs provides a framework for understanding the mechanisms by which these proteins function.

  18. A Hilbert transform method for parameter identification of time-varying structures with observer techniques

    International Nuclear Information System (INIS)

    Wang, Zuo-Cai; Ren, Wei-Xin; Chen, Gen-Da

    2012-01-01

    This paper presents a recursive Hilbert transform method for the time-varying property identification of large-scale shear-type buildings with limited sensor deployments. An observer technique is introduced to estimate the building responses from limited available measurements. For an n-story shear-type building with l measurements (l ≤ n), the responses of other stories without measurements can be estimated based on the first r mode shapes (r ≤ l) as-built conditions and l measurements. Both the measured responses and evaluated responses and their Hilbert transforms are then used to track any variation of structural parameters of a multi-story building over time. Given floor masses, both the stiffness and damping coefficients of the building are identified one-by-one from the top to the bottom story. When variations of parameters are detected, a new developed branch-and-bound technique can be used to update the first r mode shapes with the identified parameters. A 60-story shear building with abruptly varying stiffness at different floors is simulated as an example. The numerical results indicate that the proposed method can detect variations of the parameters of large-scale shear-type buildings with limited sensor deployments at appropriate locations. (paper)

  19. Antiproliferative terpenoids from almond hulls (Prunus dulcis): identification and structure-activity relationships.

    Science.gov (United States)

    Amico, Vincenzo; Barresi, Vincenza; Condorelli, Daniele; Spatafora, Carmela; Tringali, Corrado

    2006-02-08

    Bioassay-guided fractionation of the EtOAc crude extract from Sicilian almond hulls, a waste material from Prunus dulcis crop, allowed identification of 10 constituents, isolated as pure compounds (1-5, 7, and 10) or unseparable mixtures (5 + 6 and 8 + 9). All compounds were subjected to spectroscopic analysis and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide bioassay on MCF-7 human breast cancer cells. In addition to the main components oleanolic (1), ursolic (2), and betulinic (3) acids, the 2-hydroxy analogues alphitolic (4), corosolic (5), and maslinic (6) acids, as well as the related aldehydes, namely, betulinic (7), oleanolic (8), and ursolic (9), were identified. From a more polar fraction, the beta-sitosterol 3-O-glucoside (10) was also identified. A sample of commercially available betulin (11) was also included in bioassays as further support to a structure-activity relationship study. Betulinic acid showed antiproliferative activity toward MCF-7 cells (GI50 = 0.27 microM), higher than the anticancer drug 5-fluorouracil.

  20. Identification of trabecular excrescences, novel microanatomical structures, present in bone in osteoarthropathies

    Directory of Open Access Journals (Sweden)

    AM Taylor

    2012-04-01

    Full Text Available It is widely held that bone architecture is finely regulated in accordance with homeostatic requirements. Aberrant remodelling (hyperdensification and/or cyst formation in the immediately subchondral region has previously been described in bone underlying cartilage in arthropathies. The present study examined the trabecular architecture of samples of bone, initially in the severe osteoarthropathy of alkaptonuria, but subsequently in osteoarthritis using a combination of light microscopy, 3D scanning electron microscopy and quantitative backscattered electron scanning electron microscopy. We report an extraordinary and previously unrecognised bone phenotype in both disorders, including novel microanatomical structures. The underlying subchondral trabecular bone contained idiosyncratic architecture. Trabecular surfaces had numerous outgrowths that we have termed "trabecular excrescences", of which three distinct types were recognised. The first type arose from incomplete resorption of branching secondary trabeculae arising from the deposition of immature (woven bone in prior marrow space. These were characterised by very deeply scalloped surfaces and rugged edges. The second type had arisen in a similar way but been smoothed over by new bone deposition. The third type, which resembled coarse stucco, probably arises from resting surfaces that had been focally reactivated. These were poorly integrated with the prior trabecular wall. We propose that these distinctive microanatomical structures are indicative of abnormal osteoclast/osteoblast modelling in osteoarthropathies, possibly secondary to altered mechanical loading or other aberrant signalling. Identification of the mechanisms underlying the formation of trabecular excrescences will contribute to a better understanding of the role of aberrant bone remodelling in arthropathies and development of new therapeutic strategies.

  1. Human risk contributions in process industry: Guides for their pre-identification in well-structured activities and for post-incident analysis

    International Nuclear Information System (INIS)

    Pedersen, O.M.

    1985-05-01

    The report should be considered a guide for the treating of human errors: for identifying their possibilities of occurrence when designing well-structured human tasks and for their improvement when they occur in reality. For these purposes a strong coupling between predictive and retrospective analysis is emphasized: In order to control human errors, post-incident analysis of cases with human errors in a given industrial plant should be performed as means of feedback from reality for the verification of results of predictive analysis and also as general means of identifying and improving such human errors which cannot be expected covered by predictive analysis. Primarily, the guide addresses people with a knowledge of the technical plant in question and involved in the safety-oriented design and improvement of human activities and without a particular human factors background. The main report describes the procedures for post-incident analysis and for Work Analysis, which is a search strategy developed for well-defined activities, e.g. test and calibration, and constitutes a formalized procedure for the pre-identification of relevant human errors leading to a lack of task result and/or to immediate effects not covered by the lack of task result itself. Work Analysis and the post-incident analysis procedure are based on a common description system for human malfunctions. This system is explained in appendix and so are its underlying models and way of reasoning. Finally, a word index is provided for supporting the reader. (author)

  2. Identification of shallow volcanic structures in Timanfaya National Park (Lanzarote, Canary Islands) through combined geophysical prospecting techniques

    Science.gov (United States)

    Gomez-Ortiz, David; Montesinos, Fuensanta G.; Martin-Crespo, Tomas; Solla, Mercedes; Arnoso, Jose; Velez, Emilio

    2014-05-01

    The Timanfaya National Park is a volcanic area, which occupies a surface area of about 51 sq. km in the southwest of Lanzarote Island (Canary Archipelago, Spain). The 1730-1736 eruption gave rise to this volcanic landscape with more than 30 volcanic cones formed in different phases of basaltic type eruptions. It was one of the most important volcanic events occurred in the Canary Archipelago over the last 500 years. Several canyons ("jameos") are crossing this landscape in all directions, being created while the surface of the lava cooled off, and broke into pieces, falling down into the several tubes. Its location and identification is important to prevent hazards or to achieve a good exploitation from a visitor viewpoint in a restricted touristic area as the Timanfaya National Park. The use of prospective techniques to investigate the near subsurface structure of the park is very complicated, and only some regional study through gravity, magnetism and seismicity have been undertaken to attempt to model the deeper crustal structure of Lanzarote Island. This work presents a new study about the location of recent lava tubes at the volcanic area of Timanfaya National Park by the analysis and joint interpretation of high-resolution gravity, ground penetrating radar (GPR), and electromagnetic induction (EMI) data obtained over areas which had not been surveyed up to date. The studied lava flows are located at the Calderas Quemadas zone. The processed GPR radargram displays a complex pattern of reflections along the whole profile up to ~9 m depth. The strongest reflections can be grouped in four different areas defined by several hyperbolic reflections. Direct visual inspections carried out in the field allow confirming the occurrence of lava tubes at two of the locations where hyperbolic reflections are defined. Then, the strong reflections observed have been interpreted as the effect of the roof and bottom interfaces of several lava tubes. A microgravity survey along

  3. Parametric output-only identification of time-varying structures using a kernel recursive extended least squares TARMA approach

    Science.gov (United States)

    Ma, Zhi-Sai; Liu, Li; Zhou, Si-Da; Yu, Lei; Naets, Frank; Heylen, Ward; Desmet, Wim

    2018-01-01

    The problem of parametric output-only identification of time-varying structures in a recursive manner is considered. A kernelized time-dependent autoregressive moving average (TARMA) model is proposed by expanding the time-varying model parameters onto the basis set of kernel functions in a reproducing kernel Hilbert space. An exponentially weighted kernel recursive extended least squares TARMA identification scheme is proposed, and a sliding-window technique is subsequently applied to fix the computational complexity for each consecutive update, allowing the method to operate online in time-varying environments. The proposed sliding-window exponentially weighted kernel recursive extended least squares TARMA method is employed for the identification of a laboratory time-varying structure consisting of a simply supported beam and a moving mass sliding on it. The proposed method is comparatively assessed against an existing recursive pseudo-linear regression TARMA method via Monte Carlo experiments and shown to be capable of accurately tracking the time-varying dynamics. Furthermore, the comparisons demonstrate the superior achievable accuracy, lower computational complexity and enhanced online identification capability of the proposed kernel recursive extended least squares TARMA approach.

  4. Decentralized identification of nonlinear structure under strong ground motion using the extended Kalman filter and unscented Kalman filter

    Science.gov (United States)

    Tao, Dongwang; Li, Hui; Ma, Qiang

    2016-04-01

    Complete structure identification of complicate nonlinear system using extend Kalman filter (EKF) or unscented Kalman filter (UKF) may have the problems of divergence, huge computation and low estimation precision due to the large dimension of the extended state space for the system. In this article, a decentralized identification method of hysteretic system based on the joint EKF and UKF is proposed. The complete structure is divided into linear substructures and nonlinear substructures. The substructures are identified from the top to the bottom. For the linear substructure, EKF is used to identify the extended space including the displacements, velocities, stiffness and damping coefficients of the substructures, using the limited absolute accelerations and the identified interface force above the substructure. Similarly, for the nonlinear substructure, UKF is used to identify the extended space including the displacements, velocities, stiffness, damping coefficients and control parameters for the hysteretic Bouc-Wen model and the force at the interface of substructures. Finally a 10-story shear-type structure with multiple inter-story hysteresis is used for numerical simulation and is identified using the decentralized approach, and the identified results are compared with those using only EKF or UKF for the complete structure identification. The results show that the decentralized approach has the advantage of more stability, relative less computation and higher estimation precision.

  5. Unusual occurrence report

    International Nuclear Information System (INIS)

    1981-01-01

    The final report provides information on an occurrence which took place in the HEDL Radioactive Liquid Waste System (RLWS), during which radioactive waste water entered the Retention Process Waste System. The RLWS has been cleared of the obstruction and is in full operation. Investigation of the occurrence and testing of the equipment involved is completed

  6. On the structure of Bayesian network for Indonesian text document paraphrase identification

    Science.gov (United States)

    Prayogo, Ario Harry; Syahrul Mubarok, Mohamad; Adiwijaya

    2018-03-01

    Paraphrase identification is an important process within natural language processing. The idea is to automatically recognize phrases that have different forms but contain same meanings. For examples if we input query “causing fire hazard”, then the computer has to recognize this query that this query has same meaning as “the cause of fire hazard. Paraphrasing is an activity that reveals the meaning of an expression, writing, or speech using different words or forms, especially to achieve greater clarity. In this research we will focus on classifying two Indonesian sentences whether it is a paraphrase to each other or not. There are four steps in this research, first is preprocessing, second is feature extraction, third is classifier building, and the last is performance evaluation. Preprocessing consists of tokenization, non-alphanumerical removal, and stemming. After preprocessing we will conduct feature extraction in order to build new features from given dataset. There are two kinds of features in the research, syntactic features and semantic features. Syntactic features consist of normalized levenshtein distance feature, term-frequency based cosine similarity feature, and LCS (Longest Common Subsequence) feature. Semantic features consist of Wu and Palmer feature and Shortest Path Feature. We use Bayesian Networks as the method of training the classifier. Parameter estimation that we use is called MAP (Maximum A Posteriori). For structure learning of Bayesian Networks DAG (Directed Acyclic Graph), we use BDeu (Bayesian Dirichlet equivalent uniform) scoring function and for finding DAG with the best BDeu score, we use K2 algorithm. In evaluation step we perform cross-validation. The average result that we get from testing the classifier as follows: Precision 75.2%, Recall 76.5%, F1-Measure 75.8% and Accuracy 75.6%.

  7. Damage identification of beam structures using free response shapes obtained by use of a continuously scanning laser Doppler vibrometer system

    Science.gov (United States)

    Xu, Y. F.; Chen, Da-Ming; Zhu, W. D.

    2017-08-01

    Spatially dense operating deflection shapes and mode shapes can be rapidly obtained by use of a continuously scanning laser Doppler vibrometer (CSLDV) system, which sweeps its laser spot over a vibrating structure surface. This paper introduces a new type of vibration shapes called a free response shape (FRS) that can be obtained by use of a CSLDV system, and a new damage identification methodology using FRSs is developed for beam structures. An analytical expression of FRSs of a damped beam structure is derived, and FRSs from the analytical expression compare well with those from a finite element model. In the damage identification methodology, a free-response damage index (FRDI) is proposed, and damage regions can be identified near neighborhoods with consistently high values of FRDIs associated with different modes; an auxiliary FRDI is defined to assist identification of the neighborhoods. A FRDI associated with a mode consists of differences between curvatures of FRSs associated with the mode in a number of half-scan periods of a CSLDV system and those from polynomials that fit the FRSs with properly determined orders. A convergence index is proposed to determine the proper order of a polynomial fit. One advantage of the methodology is that the FRDI does not require any baseline information of an undamaged beam structure, if it is geometrically smooth and made of materials that have no stiffness and mass discontinuities. Another advantage is that FRDIs associated with multiple modes can be obtained using free response of a beam structure measured by a CSLDV system in one scan. The number of half-scan periods for calculation of the FRDI associated with a mode can be determined by use of the short-time Fourier transform. The proposed methodology was numerically and experimentally applied to identify damage in beam structures; effects of the scan frequency of a CSLDV system on qualities of obtained FRSs were experimentally investigated.

  8. Structure identification of an uncertain network coupled with complex-variable chaotic systems via adaptive impulsive control

    International Nuclear Information System (INIS)

    Liu Dan-Feng; Wu Zhao-Yan; Ye Qing-Ling

    2014-01-01

    In this paper, structure identification of an uncertain network coupled with complex-variable chaotic systems is investigated. Both the topological structure and the system parameters can be unknown and need to be identified. Based on impulsive stability theory and the Lyapunov function method, an impulsive control scheme combined with an adaptive strategy is adopted to design effective and universal network estimators. The restriction on the impulsive interval is relaxed by adopting an adaptive strategy. Further, the proposed method can monitor the online switching topology effectively. Several numerical simulations are provided to illustrate the effectiveness of the theoretical results. (general)

  9. Ferenczi's concept of identification with the aggressor: understanding dissociative structure with interacting victim and abuser self-states.

    Science.gov (United States)

    Howell, Elizabeth F

    2014-03-01

    No one has described more passionately than Ferenczi the traumatic induction of dissociative trance with its resulting fragmentation of the personality. Ferenczi introduced the concept and term, identification with the aggressor in his seminal "Confusion of Tongues" paper, in which he described how the abused child becomes transfixed and robbed of his senses. Having been traumatically overwhelmed, the child becomes hypnotically transfixed by the aggressor's wishes and behavior, automatically identifying by mimicry rather than by a purposeful identification with the aggressor's role. To expand upon Ferenczi's observations, identification with the aggressor can be understood as a two-stage process. The first stage is automatic and initiated by trauma, but the second stage is defensive and purposeful. While identification with the aggressor begins as an automatic organismic process, with repeated activation and use, gradually it becomes a defensive process. Broadly, as a dissociative defense, it has two enacted relational parts, the part of the victim and the part of the aggressor. This paper describes the intrapersonal aspects (how aggressor and victim self-states interrelate in the internal world), as well as the interpersonal aspects (how these become enacted in the external). This formulation has relevance to understanding the broad spectrum of the dissociative structure of mind, borderline personality disorder, and dissociative identity disorder.

  10. Identification of the Response of a Controlled Building Structure Subjected to Seismic Load by Using Nonlinear System Models

    Directory of Open Access Journals (Sweden)

    Mosbeh R. Kaloop

    2016-10-01

    Full Text Available The present study investigates the prediction efficiency of nonlinear system-identification models, in assessing the behavior of a coupled structure-passive vibration controller. Two system-identification models, including Nonlinear AutoRegresive with eXogenous inputs (NARX and adaptive neuro-fuzzy inference system (ANFIS, are used to model the behavior of an experimentally scaled three-story building incorporated with a tuned mass damper (TMD subjected to seismic loads. The experimental study is performed to generate the input and output data sets for training and testing the designed models. The parameters of root-mean-squared error, mean absolute error and determination coefficient statistics are used to compare the performance of the aforementioned models. A TMD controller system works efficiently to mitigate the structural vibration. The results revealed that the NARX and ANFIS models could be used to identify the response of a controlled structure. The parameters of both two time-delays of the structure response and the seismic load were proven to be effective tools in identifying the performance of the models. A comparison based on the parametric evaluation of the two methods showed that the NARX model outperforms the ANFIS model in identifying structures response.

  11. Structural and Stratigraphic Controls on Methane Hydrate occurrence and distribution: Gulf of Mexico, Walker Ridge 313 and Green Canyon 955: Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Jaiswal, Priyank [Oklahoma State Univ., Stillwater, OK (United States)

    2017-09-01

    The goal of this project was to determine structural and stratigraphic controls on hydrate occurrence and distribution in Green Canyon (GC) 955 and Walker Ridge (WR) 313 blocks using seismic and well data. Gas hydrate was discovered in these blocks in coarse- and fine-grained sediments during the 2009 Joint Industrial project (JIP) Leg 11 drilling expedition. Although the immediate interest of the exploration community is exclusively hydrate which is present in coarse–grained sediments, factors that control hydrate and free gas distribution in the two blocks and whether coarse and fine-grained hydrate-bearing units are related in any manner, formed the core of this research. The project spanned from 10/01/2012 to 07/31/2016. In the project, in both the leased blocks, the interval spanning the gas hydrate stability zone (GHSZ) was characterized using a joint analysis of sparse Ocean Bottom Seismic (OBS) and dense, surface–towed multichannel seismic (MCS) data. The project team had the luxury of calibrating their results with two well logs. Advance processing methods such as depth migration and full-waveform inversion (FWI) were used for seismic data analysis. Hydrate quantification was achieved through interpretation of the FWI velocity field using appropriate rock physics models at both blocks. The seismic modeling/inversion methodology (common to both GC955 and WR313 blocks) was as follows. First, the MCS data were depth migrated using a P-wave velocity (VP) model constructed using inversion of reflection arrival times of a few (four in both cases) key horizons carefully picked in the OBS data to farthest possible offsets. Then, the resolution of the traveltime VP model was improved to wavelength scale by inverting OBS gathers up to the highest frequency possible (21.75 Hz for GC955 and 17.5 for WR313) using FWI. Finally, the hydrate saturation (or the volume fraction) was estimated at the well location assuming one of the other hydrate morphology (filling the

  12. Recent developments in learning control and system identification for robots and structures

    Science.gov (United States)

    Phan, M.; Juang, J.-N.; Longman, R. W.

    1990-01-01

    This paper reviews recent results in learning control and learning system identification, with particular emphasis on discrete-time formulation, and their relation to adaptive theory. Related continuous-time results are also discussed. Among the topics presented are proportional, derivative, and integral learning controllers, time-domain formulation of discrete learning algorithms. Newly developed techniques are described including the concept of the repetition domain, and the repetition domain formulation of learning control by linear feedback, model reference learning control, indirect learning control with parameter estimation, as well as related basic concepts, recursive and non-recursive methods for learning identification.

  13. 20180318 - Structure identification by Mass Spectrometry Non-Targeted Analysis using the US EPA’s CompTox Chemistry Dashboard (ACS Spring)

    Science.gov (United States)

    Identification of unknowns in mass spectrometry based non-targeted analyses (NTA) requires the integration of complementary pieces of data to arrive at a confident, consensus structure. Researchers use chemical reference databases, spectral matching, fragment prediction tools, r...

  14. Structural and mechanistic investigations on Salmonella typhimurium acetate kinase (AckA: identification of a putative ligand binding pocket at the dimeric interface

    Directory of Open Access Journals (Sweden)

    Chittori Sagar

    2012-10-01

    Full Text Available Abstract Background Bacteria such as Escherichia coli and Salmonella typhimurium can utilize acetate as the sole source of carbon and energy. Acetate kinase (AckA and phosphotransacetylase (Pta, key enzymes of acetate utilization pathway, regulate flux of metabolites in glycolysis, gluconeogenesis, TCA cycle, glyoxylate bypass and fatty acid metabolism. Results Here we report kinetic characterization of S. typhimurium AckA (StAckA and structures of its unliganded (Form-I, 2.70 Å resolution and citrate-bound (Form-II, 1.90 Å resolution forms. The enzyme showed broad substrate specificity with kcat/Km in the order of acetate > propionate > formate. Further, the Km for acetyl-phosphate was significantly lower than for acetate and the enzyme could catalyze the reverse reaction (i.e. ATP synthesis more efficiently. ATP and Mg2+ could be substituted by other nucleoside 5′-triphosphates (GTP, UTP and CTP and divalent cations (Mn2+ and Co2+, respectively. Form-I StAckA represents the first structural report of an unliganded AckA. StAckA protomer consists of two domains with characteristic βββαβαβα topology of ASKHA superfamily of proteins. These domains adopt an intermediate conformation compared to that of open and closed forms of ligand-bound Methanosarcina thermophila AckA (MtAckA. Spectroscopic and structural analyses of StAckA further suggested occurrence of inter-domain motion upon ligand-binding. Unexpectedly, Form-II StAckA structure showed a drastic change in the conformation of residues 230–300 compared to that of Form-I. Further investigation revealed electron density corresponding to a citrate molecule in a pocket located at the dimeric interface of Form-II StAckA. Interestingly, a similar dimeric interface pocket lined with largely conserved residues could be identified in Form-I StAckA as well as in other enzymes homologous to AckA suggesting that ligand binding at this pocket may influence the function of these

  15. A new surface fractal dimension for displacement mode shape-based damage identification of plate-type structures

    Science.gov (United States)

    Shi, Binkai; Qiao, Pizhong

    2018-03-01

    Vibration-based nondestructive testing is an area of growing interest and worthy of exploring new and innovative approaches. The displacement mode shape is often chosen to identify damage due to its local detailed characteristic and less sensitivity to surrounding noise. Requirement for baseline mode shape in most vibration-based damage identification limits application of such a strategy. In this study, a new surface fractal dimension called edge perimeter dimension (EPD) is formulated, from which an EPD-based window dimension locus (EPD-WDL) algorithm for irregularity or damage identification of plate-type structures is established. An analytical notch-type damage model of simply-supported plates is proposed to evaluate notch effect on plate vibration performance; while a sub-domain of notch cases with less effect is selected to investigate robustness of the proposed damage identification algorithm. Then, fundamental aspects of EPD-WDL algorithm in term of notch localization, notch quantification, and noise immunity are assessed. A mathematical solution called isomorphism is implemented to remove false peaks caused by inflexions of mode shapes when applying the EPD-WDL algorithm to higher mode shapes. The effectiveness and practicability of the EPD-WDL algorithm are demonstrated by an experimental procedure on damage identification of an artificially-induced notched aluminum cantilever plate using a measurement system of piezoelectric lead-zirconate (PZT) actuator and scanning laser Doppler vibrometer (SLDV). As demonstrated in both the analytical and experimental evaluations, the new surface fractal dimension technique developed is capable of effectively identifying damage in plate-type structures.

  16. Identification, detection, and validation of vibrating structures: a signal processing approach

    International Nuclear Information System (INIS)

    Candy, J.V.; Lager, D.L.

    1979-01-01

    This report discusses the application of modern signal processing techniques to characterize parameters governing the vibrational response of a structure. Simulated response data is used to explore the feasibility of applying these techniques to various structural problems. On-line estimator/indentifiers are used to estimate structural parameters, validate designed structures, and detect structural failure when used with a detector

  17. An inverse method for the identification of a distributed random excitation acting on a vibrating structure. Theory

    International Nuclear Information System (INIS)

    Granger, S.; Perotin, L.

    1997-01-01

    Maintaining the PWR components under reliable operating conditions requires a complex design to prevent various damaging processes, including fatigue and wear problems due to flow-induced vibration. In many practical situations, it is difficult, if not impossible, to perform direct measurements or calculations of the external forces acting on vibrating structures. Instead, vibrational responses can often be conveniently measured. This paper presents an inverse method for estimating a distributed random excitation from the measurement of the structural response at a number of discrete points. This paper is devoted to the presentation of the theoretical development. The force identification method is based on a modal model for the structure and a spatial orthonormal decomposition of the excitation field. The estimation of the Fourier coefficients of this orthonormal expansion is presented. As this problem turns out to be ill-posed, a regularization process is introduced. The minimization problem associated to this process is then formulated and its solutions is developed. (author)

  18. Comparing Effect of 'Summarizing', 'Question-Answer Relationship', and 'Syntactic Structure Identification' on the Reading Comprehension of Iranian EFL students

    Directory of Open Access Journals (Sweden)

    Fatemeh Hemmati

    2013-01-01

    Full Text Available This study aimed at comparing the effects of 'question-answer relationship strategy', 'summarizing', and 'syntactic structure identification training'on the reading comprehension of Iranian EFL learners. The participants were sixty (34 women and 26 men intermediate students who answered an English reading comprehension test consisting of three reading passages as the pretest. During the treatment, the students in the first group were supposed to summarize the passages. The subjects in the second group familiarized with the syntactic structure identification strategy and the ones in the third group were taught the question-answer relationship strategy. At the end of the treatment, an English reading comprehension test similar to the pretest was administered to the groups as a posttest. The results suggested that there is statistically significant difference between the reading comprehension abilities of the three classes. Furthermore the use of QAR strategy led to better comprehension of reading texts with syntactic structure training and summarizing between which there was no significant difference.

  19. The person in the mirror: using the enfacement illusion to investigate the experiential structure of self-identification.

    Science.gov (United States)

    Tajadura-Jiménez, Ana; Longo, Matthew R; Coleman, Rosie; Tsakiris, Manos

    2012-12-01

    How do we acquire a mental representation of our own face? Recently, synchronous, but not asynchronous, interpersonal multisensory stimulation (IMS) between one's own and another person's face has been used to evoke changes in self-identification (enfacement illusion). We investigated the conscious experience of these changes with principal component analyses (PCA) that revealed that while the conscious experience during synchronous IMS focused on resemblance and similarity with the other's face, during asynchronous IMS it focused on multisensory stimulation. Analyses of the identified common factor structure revealed significant quantitative differences between synchronous and asynchronous IMS on self-identification and perceived similarity with the other's face. Experiment 2 revealed that participants with lower interoceptive sensitivity experienced stronger enfacement illusion. Overall, self-identification and body-ownership rely on similar basic mechanisms of multisensory integration, but the effects of multisensory input on their experience are qualitatively different, possibly underlying the face's unique role as a marker of selfhood. Copyright © 2012 Elsevier Inc. All rights reserved.

  20. The Shock and Vibration Bulletin. Part 3. Machinery Dynamics, System Identification and Structural Analysis

    Science.gov (United States)

    1985-06-01

    purposes. 55 15 525 + 2 225L L53 + L3 ) + 2G3(L 2 + L35L4 + L45)" For the present system identification + 2G(L45 2 + L45L5 + L5 "L 1 technique, the...orbital model is comprised of 257 nodes and 819 dynamic:"DOF’s. k; were compared to ITD results for a wide variety of TD input parameters. Overall, the

  1. A Two-Step Strategy for System Identification of Civil Structures for Structural Health Monitoring Using Wavelet Transform and Genetic Algorithms

    Directory of Open Access Journals (Sweden)

    Carlos Andres Perez-Ramirez

    2017-01-01

    Full Text Available Nowadays, the accurate identification of natural frequencies and damping ratios play an important role in smart civil engineering, since they can be used for seismic design, vibration control, and condition assessment, among others. To achieve it in practical way, it is required to instrument the structure and apply techniques which are able to deal with noise-corrupted and non-linear signals, as they are common features in real-life civil structures. In this article, a two-step strategy is proposed for performing accurate modal parameters identification in an automated manner. In the first step, it is obtained and decomposed the measured signals using the natural excitation technique and the synchrosqueezed wavelet transform, respectively. Then, the second step estimates the modal parameters by solving an optimization problem employing a genetic algorithm-based approach, where the micropopulation concept is used to improve the speed convergence as well as the accuracy of the estimated values. The accuracy and effectiveness of the proposal are tested using both the simulated response of a benchmark structure and the measurements of a real eight-story building. The obtained results show that the proposed strategy can estimate the modal parameters accurately, indicating than the proposal can be considered as an alternative to perform the abovementioned task.

  2. Identification of the c(10×6)-CN/Cu(001) surface structure

    KAUST Repository

    Shuttleworth, I.G.

    2014-01-01

    © 2014 Elsevier B.V. All rights reserved. A systematic survey of all possible c(10 x 6)-CN/Cu(0 0 1) structures has been performed using density functional theory (DFT). A group of four preferred structures is presented with one of the structures identified as optimal. An analysis of the bonding within the optimal structure has shown that a significant localisation of the surface Cu 4s bonds occurs in the saturated system.

  3. Identification of the c(10×6)-CN/Cu(001) surface structure

    KAUST Repository

    Shuttleworth, I.G.

    2014-12-01

    © 2014 Elsevier B.V. All rights reserved. A systematic survey of all possible c(10 x 6)-CN/Cu(0 0 1) structures has been performed using density functional theory (DFT). A group of four preferred structures is presented with one of the structures identified as optimal. An analysis of the bonding within the optimal structure has shown that a significant localisation of the surface Cu 4s bonds occurs in the saturated system.

  4. Structure-sequence based analysis for identification of conserved regions in proteins

    Science.gov (United States)

    Zemla, Adam T; Zhou, Carol E; Lam, Marisa W; Smith, Jason R; Pardes, Elizabeth

    2013-05-28

    Disclosed are computational methods, and associated hardware and software products for scoring conservation in a protein structure based on a computationally identified family or cluster of protein structures. A method of computationally identifying a family or cluster of protein structures in also disclosed herein.

  5. Validity of active fault identification through magnetic anomalous using earthquake mechanism, microgravity and topography structure analysis in Cisolok area

    Science.gov (United States)

    Setyonegoro, Wiko; Kurniawan, Telly; Ahadi, Suaidi; Rohadi, Supriyanto; Hardy, Thomas; Prayogo, Angga S.

    2017-07-01

    Research was conducted to determine the value of the magnetic anomalies to identify anomalous value standard fault, down or up with the type of Meratus trending northeast-southwest Cisolok, Sukabumi. Data collection was performed by setting the measurement grid at intervals of 5 meters distance measurement using a Precision Proton Magnetometer (PPM) -GSM-19T. To identification the active fault using magnetic is needed another parameter. The purpose of this study is to identification active fault using magnetic Anomaly in related with subsurface structure through the validation analysis of earthquake mechanism, microgravity and with Topography Structure in Java Island. Qualitative interpretation is done by analyzing the residual anomaly that has been reduced to the pole while the quantitative interpretation is done by analyzing the pattern of residual anomalies through computation. The results of quantitative interpretation, an anomalous value reduction to the pole magnetic field is at -700 nT to 700 nT while the results of the qualitative interpretation of the modeling of the path AA', BB' and CC' shows the magnetic anomaly at coordinates liquefaction resources with a value of 1028.04, 1416.21, - 1565, -1686.91. The measurement results obtained in Cisolok magnetic anomalies that indicate a high content of alumina (Al) and iron (Fe) which be identified appears through the fault gap towards the northeast through Rajamandala Lembang Fault related to the mechanism in the form of a normal fault with slip rate of 2 mm / year.

  6. The identification and functional annotation of RNA structures conserved in vertebrates

    DEFF Research Database (Denmark)

    Seemann, Ernst Stefan; Mirza, Aashiq Hussain; Hansen, Claus

    2017-01-01

    Structured elements of RNA molecules are essential in, e.g., RNA stabilization, localization and protein interaction, and their conservation across species suggests a common functional role. We computationally screened vertebrate genomes for Conserved RNA Structures (CRSs), leveraging structure...... (RBPs) or (ii) are transcribed in corresponding tissues. Additionally, a CaptureSeq experiment revealed expression of many of our CRS regions in human fetal brain, including 662 novel ones. For selected human and mouse candidate pairs, qRT-PCR and in vitro RNA structure probing supported both shared...... expression and shared structure despite low abundance and low sequence identity. About 30k CRS regions are located near coding or long non-coding RNA genes or within enhancers. Structured (CRS overlapping) enhancer RNAs and extended 3' ends have significantly increased expression levels over their non-structured...

  7. The identification and functional annotation of RNA structures conserved in vertebrates

    DEFF Research Database (Denmark)

    Seemann, Ernst Stefan; Mirza, Aashiq Hussain; Hansen, Claus

    2017-01-01

    Structured elements of RNA molecules are essential in, e.g., RNA stabilization, localization and protein interaction, and their conservation across species suggests a common functional role. We computationally screened vertebrate genomes for Conserved RNA Structures (CRSs), leveraging structure-b......-structured counterparts. Our findings of transcribed uncharacterized regulatory regions that contain CRSs support their RNA-mediated functionality.......Structured elements of RNA molecules are essential in, e.g., RNA stabilization, localization and protein interaction, and their conservation across species suggests a common functional role. We computationally screened vertebrate genomes for Conserved RNA Structures (CRSs), leveraging structure......-based, rather than sequence-based, alignments. After careful correction for sequence identity and GC content, we predict ~516k human genomic regions containing CRSs. We find that a substantial fraction of human-mouse CRS regions (i) co-localize consistently with binding sites of the same RNA binding proteins...

  8. Identification and Structural Characterization of Naturally-Occurring Broad-Spectrum Cyclic Antibiotics Isolated from Paenibacillus

    Science.gov (United States)

    Knolhoff, Ann M.; Zheng, Jie; McFarland, Melinda A.; Luo, Yan; Callahan, John H.; Brown, Eric W.; Croley, Timothy R.

    2015-08-01

    The rise of antimicrobial resistance necessitates the discovery and/or production of novel antibiotics. Isolated strains of Paenibacillus alvei were previously shown to exhibit antimicrobial activity against a number of pathogens, such as E. coli, Salmonella, and methicillin-resistant Staphylococcus aureus (MRSA). The responsible antimicrobial compounds were isolated from these Paenibacillus strains and a combination of low and high resolution mass spectrometry with multiple-stage tandem mass spectrometry was used for identification. A group of closely related cyclic lipopeptides was identified, differing primarily by fatty acid chain length and one of two possible amino acid substitutions. Variation in the fatty acid length resulted in mass differences of 14 Da and yielded groups of related MSn spectra. Despite the inherent complexity of MS/MS spectra of cyclic compounds, straightforward analysis of these spectra was accomplished by determining differences in complementary product ion series between compounds that differ in molecular weight by 14 Da. The primary peptide sequence assignment was confirmed through genome mining; the combination of these analytical tools represents a workflow that can be used for the identification of complex antibiotics. The compounds also share amino acid sequence similarity to a previously identified broad-spectrum antibiotic isolated from Paenibacillus. The presence of such a wide distribution of related compounds produced by the same organism represents a novel class of broad-spectrum antibiotic compounds.

  9. Identification and visualization of the intellectual structure and the main research lines in nanoscience and nanotechnology at the worldwide level

    International Nuclear Information System (INIS)

    Muñoz-Écija, Teresa; Vargas-Quesada, Benjamín; Chinchilla-Rodríguez, Zaida

    2017-01-01

    The aim of this paper is to make manifest the intellectual and cognitive structure of nanoscience and nanotechnology (NST) by means of visualization techniques. To this end, we used data from the Web of Science (WoS), delimiting the data to the category NST during the period of 2000–2013, retrieving a total of 198,275 documents. Through direct author citation of these works, we identified their origins and the seminal papers, and through word co-occurrence extracted from the titles and abstracts, the main lines of research were identified. In view of both structures, we may affirm that NST is a young scientific discipline in constant expansion, needing time to establish its foundations but showing a strongly interdisciplinary character; its development is furthermore dependent upon knowledge from other disciplines, such as physics, chemistry, or material sciences. We believe that this information may be very useful for the NST scientific community, as it reflects a large-scale analysis of the research lines of NST and how research has changed over time in the diverse areas of NST. This study is moreover intended to offer a useful tool for the NST scientific community, revealing at a glance the main research lines and landmark papers. Finally, the methodology used in this study can be replicated in any other field of science to explore its intellectual and cognitive structure.

  10. Identification and visualization of the intellectual structure and the main research lines in nanoscience and nanotechnology at the worldwide level

    Energy Technology Data Exchange (ETDEWEB)

    Muñoz-Écija, Teresa, E-mail: teresamunyozecija@gmail.com; Vargas-Quesada, Benjamín, E-mail: benjamin@ugr.es [University of Granada, Department of Information and Communication, Faculty of Communication and Documentation, SCImago Research Group (Spain); Chinchilla-Rodríguez, Zaida, E-mail: zaida.chinchilla@csic.es [CSIC, Institute of Public Goods and Policies (IPP), SCImago Research Group (Spain)

    2017-02-15

    The aim of this paper is to make manifest the intellectual and cognitive structure of nanoscience and nanotechnology (NST) by means of visualization techniques. To this end, we used data from the Web of Science (WoS), delimiting the data to the category NST during the period of 2000–2013, retrieving a total of 198,275 documents. Through direct author citation of these works, we identified their origins and the seminal papers, and through word co-occurrence extracted from the titles and abstracts, the main lines of research were identified. In view of both structures, we may affirm that NST is a young scientific discipline in constant expansion, needing time to establish its foundations but showing a strongly interdisciplinary character; its development is furthermore dependent upon knowledge from other disciplines, such as physics, chemistry, or material sciences. We believe that this information may be very useful for the NST scientific community, as it reflects a large-scale analysis of the research lines of NST and how research has changed over time in the diverse areas of NST. This study is moreover intended to offer a useful tool for the NST scientific community, revealing at a glance the main research lines and landmark papers. Finally, the methodology used in this study can be replicated in any other field of science to explore its intellectual and cognitive structure.

  11. Identification and Structural Characterization of Novel A-kinase Anchoring Proteins

    NARCIS (Netherlands)

    Burgers, P.P.

    2014-01-01

    The work described in this thesis initially focusses on the discovery of a novel PKA-RI specific AKAP: small membrane AKAP (smAKAP). Afterwards we centre on the structural interaction between smAKAP and PKA-RI to reveal the first PKA-RI specific AKAP bound to PKA-RI crystal structure. Interestingly,

  12. Genome-wide identification of structural variants in genes encoding drug targets

    DEFF Research Database (Denmark)

    Rasmussen, Henrik Berg; Dahmcke, Christina Mackeprang

    2012-01-01

    The objective of the present study was to identify structural variants of drug target-encoding genes on a genome-wide scale. We also aimed at identifying drugs that are potentially amenable for individualization of treatments based on knowledge about structural variation in the genes encoding...

  13. Automatic identification of mobile and rigid substructures in molecular dynamics simulations and fractional structural fluctuation analysis.

    Directory of Open Access Journals (Sweden)

    Leandro Martínez

    Full Text Available The analysis of structural mobility in molecular dynamics plays a key role in data interpretation, particularly in the simulation of biomolecules. The most common mobility measures computed from simulations are the Root Mean Square Deviation (RMSD and Root Mean Square Fluctuations (RMSF of the structures. These are computed after the alignment of atomic coordinates in each trajectory step to a reference structure. This rigid-body alignment is not robust, in the sense that if a small portion of the structure is highly mobile, the RMSD and RMSF increase for all atoms, resulting possibly in poor quantification of the structural fluctuations and, often, to overlooking important fluctuations associated to biological function. The motivation of this work is to provide a robust measure of structural mobility that is practical, and easy to interpret. We propose a Low-Order-Value-Optimization (LOVO strategy for the robust alignment of the least mobile substructures in a simulation. These substructures are automatically identified by the method. The algorithm consists of the iterative superposition of the fraction of structure displaying the smallest displacements. Therefore, the least mobile substructures are identified, providing a clearer picture of the overall structural fluctuations. Examples are given to illustrate the interpretative advantages of this strategy. The software for performing the alignments was named MDLovoFit and it is available as free-software at: http://leandro.iqm.unicamp.br/mdlovofit.

  14. Identification of Damage in IR-Structures from Earthquake Records - Optimal Location of Sensors

    DEFF Research Database (Denmark)

    Nielsen, Søren R.K.; Skjærbæk, P. S.; Cakmak, A. S.

    A method for localization of structural damage is seismically excited RC-structures using measured acceleration response time series is presented. from measured response from some or all storeys, the two lowest smoothed eigenfrequencies and mode shape coordinates are estimated. these estimates ar...

  15. Fast identification of folded human protein domains expressed in E. coli suitable for structural analysis

    Directory of Open Access Journals (Sweden)

    Schlegel Brigitte

    2004-03-01

    Full Text Available Abstract Background High-throughput protein structure analysis of individual protein domains requires analysis of large numbers of expression clones to identify suitable constructs for structure determination. For this purpose, methods need to be implemented for fast and reliable screening of the expressed proteins as early as possible in the overall process from cloning to structure determination. Results 88 different E. coli expression constructs for 17 human protein domains were analysed using high-throughput cloning, purification and folding analysis to obtain candidates suitable for structural analysis. After 96 deep-well microplate expression and automated protein purification, protein domains were directly analysed using 1D 1H-NMR spectroscopy. In addition, analytical hydrophobic interaction chromatography (HIC was used to detect natively folded protein. With these two analytical methods, six constructs (representing two domains were quickly identified as being well folded and suitable for structural analysis. Conclusion The described approach facilitates high-throughput structural analysis. Clones expressing natively folded proteins suitable for NMR structure determination were quickly identified upon small scale expression screening using 1D 1H-NMR and/or analytical HIC. This procedure is especially effective as a fast and inexpensive screen for the 'low hanging fruits' in structural genomics.

  16. Identification of individual coherent sets associated with flow trajectories using coherent structure coloring

    Science.gov (United States)

    Schlueter-Kuck, Kristy L.; Dabiri, John O.

    2017-09-01

    We present a method for identifying the coherent structures associated with individual Lagrangian flow trajectories even where only sparse particle trajectory data are available. The method, based on techniques in spectral graph theory, uses the Coherent Structure Coloring vector and associated eigenvectors to analyze the distance in higher-dimensional eigenspace between a selected reference trajectory and other tracer trajectories in the flow. By analyzing this distance metric in a hierarchical clustering, the coherent structure of which the reference particle is a member can be identified. This algorithm is proven successful in identifying coherent structures of varying complexities in canonical unsteady flows. Additionally, the method is able to assess the relative coherence of the associated structure in comparison to the surrounding flow. Although the method is demonstrated here in the context of fluid flow kinematics, the generality of the approach allows for its potential application to other unsupervised clustering problems in dynamical systems such as neuronal activity, gene expression, or social networks.

  17. An application of impediography to the high sensitivity and high resolution identification of structural damage

    International Nuclear Information System (INIS)

    Zhao, L; Yang, J; Semperlotti, F; Wang, K W

    2015-01-01

    In this study we explore the use of impediographic techniques to perform damage detection in plate-like metal structures. Impediography relies on the piezo-resistive coupling of the host structure to reconstruct high sensitivity and high resolution maps of the internal electrical conductivity. By exploiting localized strain perturbations generated via focused acoustic waves, the piezo-resistive coupling allows extracting a set of linearly independent boundary voltage data that drastically reduces the ill-conditioning of the inverse problem, therefore increasing the performance. The localized perturbation is achieved by leveraging the concept of frequency selective structure (FSS), that is a dynamically tailored structural element enabling the required acoustic focusing via vibration localization. Based on the FSS approach, the impediographic technique is numerically tested to investigate the performance of the combined approach for structural damage detection. The effects of practical implementation issues, such as limited perturbations and limited boundary data, are also explored. (paper)

  18. Source identification in acoustics and structural mechanics using Sierra/SD.

    Energy Technology Data Exchange (ETDEWEB)

    Walsh, Timothy Francis; Aquino, Wilkins [Duke University Durham, NC; Ross, Michael

    2013-03-01

    In this report we derive both time and frequency-domain methods for inverse identification of sources in elastodynamics and acoustics. The inverse/design problem is cast in a PDE-constrained optimization framework with efficient computation of gradients using the adjoint method. The implementation of source inversion in Sierra/SD is described, and results from both time and frequency domain source inversion are compared to actual experimental data for a weapon store used in captive carry on a military aircraft. The inverse methodology is advantageous in that it provides a method for creating ground based acoustic and vibration tests that can reduce the actual number of flight tests, and thus, saving costs and time for the program.

  19. The Dictyostelium discoideum cellulose synthase: Structure/function analysis and identification of interacting proteins

    Energy Technology Data Exchange (ETDEWEB)

    Richard L. Blanton

    2004-02-19

    OAK-B135 The major accomplishments of this project were: (1) the initial characterization of dcsA, the gene for the putative catalytic subunit of cellulose synthase in the cellular slime mold Dictyostelium discoideum; (2) the detection of a developmentally regulated event (unidentified, but perhaps a protein modification or association with a protein partner) that is required for cellulose synthase activity (i.e., the dcsA product is necessary, but not sufficient for cellulose synthesis); (3) the continued exploration of the developmental context of cellulose synthesis and DcsA; (4) the isolation of a GFP-DcsA-expressing strain (work in progress); and (5) the identification of Dictyostelium homologues for plant genes whose products play roles in cellulose biosynthesis. Although our progress was slow and many of our results negative, we did develop a number of promising avenues of investigation that can serve as the foundation for future projects.

  20. The Performance of Structure-Controller Coupled Systems Analysis Using Probabilistic Evaluation and Identification Model Approach

    Directory of Open Access Journals (Sweden)

    Mosbeh R. Kaloop

    2017-01-01

    Full Text Available This study evaluates the performance of passively controlled steel frame building under dynamic loads using time series analysis. A novel application is utilized for the time and frequency domains evaluation to analyze the behavior of controlling systems. In addition, the autoregressive moving average (ARMA neural networks are employed to identify the performance of the controller system. Three passive vibration control devices are utilized in this study, namely, tuned mass damper (TMD, tuned liquid damper (TLD, and tuned liquid column damper (TLCD. The results show that the TMD control system is a more reliable controller than TLD and TLCD systems in terms of vibration mitigation. The probabilistic evaluation and identification model showed that the probability analysis and ARMA neural network model are suitable to evaluate and predict the response of coupled building-controller systems.

  1. Networks of high mutual information define the structural proximity of catalytic sites: implications for catalytic residue identification.

    Directory of Open Access Journals (Sweden)

    Cristina Marino Buslje

    Full Text Available Identification of catalytic residues (CR is essential for the characterization of enzyme function. CR are, in general, conserved and located in the functional site of a protein in order to attain their function. However, many non-catalytic residues are highly conserved and not all CR are conserved throughout a given protein family making identification of CR a challenging task. Here, we put forward the hypothesis that CR carry a particular signature defined by networks of close proximity residues with high mutual information (MI, and that this signature can be applied to distinguish functional from other non-functional conserved residues. Using a data set of 434 Pfam families included in the catalytic site atlas (CSA database, we tested this hypothesis and demonstrated that MI can complement amino acid conservation scores to detect CR. The Kullback-Leibler (KL conservation measurement was shown to significantly outperform both the Shannon entropy and maximal frequency measurements. Residues in the proximity of catalytic sites were shown to be rich in shared MI. A structural proximity MI average score (termed pMI was demonstrated to be a strong predictor for CR, thus confirming the proposed hypothesis. A structural proximity conservation average score (termed pC was also calculated and demonstrated to carry distinct information from pMI. A catalytic likeliness score (Cls, combining the KL, pC and pMI measures, was shown to lead to significantly improved prediction accuracy. At a specificity of 0.90, the Cls method was found to have a sensitivity of 0.816. In summary, we demonstrate that networks of residues with high MI provide a distinct signature on CR and propose that such a signature should be present in other classes of functional residues where the requirement to maintain a particular function places limitations on the diversification of the structural environment along the course of evolution.

  2. Networks of high mutual information define the structural proximity of catalytic sites: implications for catalytic residue identification.

    Science.gov (United States)

    Marino Buslje, Cristina; Teppa, Elin; Di Doménico, Tomas; Delfino, José María; Nielsen, Morten

    2010-11-04

    Identification of catalytic residues (CR) is essential for the characterization of enzyme function. CR are, in general, conserved and located in the functional site of a protein in order to attain their function. However, many non-catalytic residues are highly conserved and not all CR are conserved throughout a given protein family making identification of CR a challenging task. Here, we put forward the hypothesis that CR carry a particular signature defined by networks of close proximity residues with high mutual information (MI), and that this signature can be applied to distinguish functional from other non-functional conserved residues. Using a data set of 434 Pfam families included in the catalytic site atlas (CSA) database, we tested this hypothesis and demonstrated that MI can complement amino acid conservation scores to detect CR. The Kullback-Leibler (KL) conservation measurement was shown to significantly outperform both the Shannon entropy and maximal frequency measurements. Residues in the proximity of catalytic sites were shown to be rich in shared MI. A structural proximity MI average score (termed pMI) was demonstrated to be a strong predictor for CR, thus confirming the proposed hypothesis. A structural proximity conservation average score (termed pC) was also calculated and demonstrated to carry distinct information from pMI. A catalytic likeliness score (Cls), combining the KL, pC and pMI measures, was shown to lead to significantly improved prediction accuracy. At a specificity of 0.90, the Cls method was found to have a sensitivity of 0.816. In summary, we demonstrate that networks of residues with high MI provide a distinct signature on CR and propose that such a signature should be present in other classes of functional residues where the requirement to maintain a particular function places limitations on the diversification of the structural environment along the course of evolution.

  3. Identification, structure, and function of a novel type VI secretion peptidoglycan glycoside hydrolase effector-immunity pair.

    Science.gov (United States)

    Whitney, John C; Chou, Seemay; Russell, Alistair B; Biboy, Jacob; Gardiner, Taylor E; Ferrin, Michael A; Brittnacher, Mitchell; Vollmer, Waldemar; Mougous, Joseph D

    2013-09-13

    Bacteria employ type VI secretion systems (T6SSs) to facilitate interactions with prokaryotic and eukaryotic cells. Despite the widespread identification of T6SSs among Gram-negative bacteria, the number of experimentally validated substrate effector proteins mediating these interactions remains small. Here, employing an informatics approach, we define novel families of T6S peptidoglycan glycoside hydrolase effectors. Consistent with the known intercellular self-intoxication exhibited by the T6S pathway, we observe that each effector gene is located adjacent to a hypothetical open reading frame encoding a putative periplasmically localized immunity determinant. To validate our sequence-based approach, we functionally investigate a representative family member from the soil-dwelling bacterium Pseudomonas protegens. We demonstrate that this protein is secreted in a T6SS-dependent manner and that it confers a fitness advantage in growth competition assays with Pseudomonas putida. In addition, we determined the 1.4 Å x-ray crystal structure of this effector in complex with its cognate immunity protein. The structure reveals the effector shares highest overall structural similarity to a glycoside hydrolase family associated with peptidoglycan N-acetylglucosaminidase activity, suggesting that T6S peptidoglycan glycoside hydrolase effector families may comprise significant enzymatic diversity. Our structural analyses also demonstrate that self-intoxication is prevented by the immunity protein through direct occlusion of the effector active site. This work significantly expands our current understanding of T6S effector diversity.

  4. Identification, Structure, and Function of a Novel Type VI Secretion Peptidoglycan Glycoside Hydrolase Effector-Immunity Pair*

    Science.gov (United States)

    Whitney, John C.; Chou, Seemay; Russell, Alistair B.; Biboy, Jacob; Gardiner, Taylor E.; Ferrin, Michael A.; Brittnacher, Mitchell; Vollmer, Waldemar; Mougous, Joseph D.

    2013-01-01

    Bacteria employ type VI secretion systems (T6SSs) to facilitate interactions with prokaryotic and eukaryotic cells. Despite the widespread identification of T6SSs among Gram-negative bacteria, the number of experimentally validated substrate effector proteins mediating these interactions remains small. Here, employing an informatics approach, we define novel families of T6S peptidoglycan glycoside hydrolase effectors. Consistent with the known intercellular self-intoxication exhibited by the T6S pathway, we observe that each effector gene is located adjacent to a hypothetical open reading frame encoding a putative periplasmically localized immunity determinant. To validate our sequence-based approach, we functionally investigate a representative family member from the soil-dwelling bacterium Pseudomonas protegens. We demonstrate that this protein is secreted in a T6SS-dependent manner and that it confers a fitness advantage in growth competition assays with Pseudomonas putida. In addition, we determined the 1.4 Å x-ray crystal structure of this effector in complex with its cognate immunity protein. The structure reveals the effector shares highest overall structural similarity to a glycoside hydrolase family associated with peptidoglycan N-acetylglucosaminidase activity, suggesting that T6S peptidoglycan glycoside hydrolase effector families may comprise significant enzymatic diversity. Our structural analyses also demonstrate that self-intoxication is prevented by the immunity protein through direct occlusion of the effector active site. This work significantly expands our current understanding of T6S effector diversity. PMID:23878199

  5. Identification of a Buried Late Cenozoic Maar-Diatreme Structure (North Moravia, Czech Republic

    Directory of Open Access Journals (Sweden)

    Šešulka Vojtěch

    2015-01-01

    Full Text Available The maar-diatreme volcanic structure in the vicinity of the village of Lomnice near the town of Bruntál (North Moravia, Czech Republic has been investigated using a set of geophysical methods including ground magnetometry, gravimetry and electrical resistivity tomography. The structure was detected by an aerial magnetic survey in the second half of the 20th century. Since its discovery only limited information about this buried structure has been available. The coherence of the magnetic anomaly of 190 nT and Bouguer anomaly of -4.7 mGal indicates a volcanic origin of the structure. The funnel-shaped maar-diatreme structure is filled with lacustrine clay and colluvium of Car-boniferous greywacke, which forms the country rock. The surface diameter of the structure is about 600 m, the depth is more than 400 m. The spatial association with other volcanic centers in the surroundings of the town of Bruntál infers the relative dating of the Lomnice maar. The phreatic eruption and maar-diatreme formation could be an indirect conse-quence of effusive activity of the nearby Velký Roudný volcano. The Lomnice structure is the first Plio-Pleistocene maar-diatreme ever described in North Moravia and Silesia.

  6. Using support vector machines to improve elemental ion identification in macromolecular crystal structures

    Energy Technology Data Exchange (ETDEWEB)

    Morshed, Nader [University of California, Berkeley, CA 94720 (United States); Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Echols, Nathaniel, E-mail: nechols@lbl.gov [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Adams, Paul D., E-mail: nechols@lbl.gov [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); University of California, Berkeley, CA 94720 (United States)

    2015-05-01

    A method to automatically identify possible elemental ions in X-ray crystal structures has been extended to use support vector machine (SVM) classifiers trained on selected structures in the PDB, with significantly improved sensitivity over manually encoded heuristics. In the process of macromolecular model building, crystallographers must examine electron density for isolated atoms and differentiate sites containing structured solvent molecules from those containing elemental ions. This task requires specific knowledge of metal-binding chemistry and scattering properties and is prone to error. A method has previously been described to identify ions based on manually chosen criteria for a number of elements. Here, the use of support vector machines (SVMs) to automatically classify isolated atoms as either solvent or one of various ions is described. Two data sets of protein crystal structures, one containing manually curated structures deposited with anomalous diffraction data and another with automatically filtered, high-resolution structures, were constructed. On the manually curated data set, an SVM classifier was able to distinguish calcium from manganese, zinc, iron and nickel, as well as all five of these ions from water molecules, with a high degree of accuracy. Additionally, SVMs trained on the automatically curated set of high-resolution structures were able to successfully classify most common elemental ions in an independent validation test set. This method is readily extensible to other elemental ions and can also be used in conjunction with previous methods based on a priori expectations of the chemical environment and X-ray scattering.

  7. Identification of Lygus hesperus by DNA barcoding reveals insignificant levels of genetic structure among distant and habitat diverse populations.

    Directory of Open Access Journals (Sweden)

    Changqing Zhou

    Full Text Available BACKGROUND: The western tarnished plant bug Lygus hesperus is an economically important pest that belongs to a complex of morphologically similar species that makes identification problematic. The present study provides evidence for the use of DNA barcodes from populations of L. hesperus from the western United States of America for accurate identification. METHODOLOGY/PRINCIPAL FINDINGS: This study reports DNA barcodes for 134 individuals of the western tarnished plant bug from alfalfa and strawberry agricultural fields in the western United States of America. Sequence divergence estimates of <3% reveal that morphologically variable individuals presumed to be L. hesperus were accurately identified. Paired estimates of F(st and subsequent estimates of gene flow show that geographically distinct populations of L. hesperus are genetically similar. Therefore, our results support and reinforce the relatively recent (<100 years migration of the western tarnished plant bug into agricultural habitats across the western United States. CONCLUSIONS/SIGNIFICANCE: This study reveals that despite wide host plant usage and phenotypically plastic morphological traits, the commonly recognized western tarnished plant bug belongs to a single species, Lygus hesperus. In addition, no significant genetic structure was found for the geographically diverse populations of western tarnished plant bug used in this study.

  8. Occurrence of high molecular weight lipids (C{sub 80+}) in the trilaminar outer cell walls of some freshwater microalgae. A reappraisal of algaenan structure

    Energy Technology Data Exchange (ETDEWEB)

    Allard, B.; Templier, J. [UMR CNRS, Paris (France). Laboratoire de Chimie Bioorganique et Organique Physique; Rager, M.-N. [UMR CNRS, Paris (France). Service RMN

    2002-07-01

    The purified cell walls of mother cells (CWM) were isolated from three strains of trilaminar sheath (TLS)- and algaenan-containing freshwater microalgae Chlorella emersonii, Tetraedron minimum and Scenedesmus communis. The chemical structures of CWM and algaenans were investigated by means of tetramethylammonium hydroxide (TMAH) hydrolysis and tetramethylammonium hydroxide thermochemolysis. The compounds released were characterised by {sup 1}H and {sup 13}C-NMR, gel permeation chromatography and desorption chemical ionisation mass spectrometry. The results show that the outer cell walls of the microalgae are constituted, at least in part, of linear (poly)esters containing extremely long chain alcohol and acid moieties (up to C{sub 80}) and that algaenans are mainly composed of extremely long chain (di)carboxylic acids up to C{sub 120}. The present results which are in direct contrast to the previous three-dimensional architecture proposed for algaenans, led us to re-interpret the algaenan structure. (Author)

  9. Structure identification and adaptive synchronization of uncertain general complex dynamical networks

    Energy Technology Data Exchange (ETDEWEB)

    Xu Yuhua, E-mail: yuhuaxu2004@163.co [College of Information Science and Technology, Donghua University, Shanghai 201620 (China) and Department of Maths, Yunyang Teacher' s College, Hubei 442000 (China); Zhou Wuneng, E-mail: wnzhou@163.co [College of Information Science and Technology, Donghua University, Shanghai 201620 (China); Fang Jian' an [College of Information Science and Technology, Donghua University, Shanghai 201620 (China); Lu Hongqian [Shandong Institute of Light Industry, Shandong Jinan 250353 (China)

    2009-12-28

    This Letter proposes an approach to identify the topological structure and unknown parameters for uncertain general complex networks simultaneously. By designing effective adaptive controllers, we achieve synchronization between two complex networks. The unknown network topological structure and system parameters of uncertain general complex dynamical networks are identified simultaneously in the process of synchronization. Several useful criteria for synchronization are given. Finally, an illustrative example is presented to demonstrate the application of the theoretical results.

  10. Structure identification and adaptive synchronization of uncertain general complex dynamical networks

    International Nuclear Information System (INIS)

    Xu Yuhua; Zhou Wuneng; Fang Jian'an; Lu Hongqian

    2009-01-01

    This Letter proposes an approach to identify the topological structure and unknown parameters for uncertain general complex networks simultaneously. By designing effective adaptive controllers, we achieve synchronization between two complex networks. The unknown network topological structure and system parameters of uncertain general complex dynamical networks are identified simultaneously in the process of synchronization. Several useful criteria for synchronization are given. Finally, an illustrative example is presented to demonstrate the application of the theoretical results.

  11. The identification and functional annotation of RNA structures conserved in vertebrates.

    Science.gov (United States)

    Seemann, Stefan E; Mirza, Aashiq H; Hansen, Claus; Bang-Berthelsen, Claus H; Garde, Christian; Christensen-Dalsgaard, Mikkel; Torarinsson, Elfar; Yao, Zizhen; Workman, Christopher T; Pociot, Flemming; Nielsen, Henrik; Tommerup, Niels; Ruzzo, Walter L; Gorodkin, Jan

    2017-08-01

    Structured elements of RNA molecules are essential in, e.g., RNA stabilization, localization, and protein interaction, and their conservation across species suggests a common functional role. We computationally screened vertebrate genomes for conserved RNA structures (CRSs), leveraging structure-based, rather than sequence-based, alignments. After careful correction for sequence identity and GC content, we predict ∼516,000 human genomic regions containing CRSs. We find that a substantial fraction of human-mouse CRS regions (1) colocalize consistently with binding sites of the same RNA binding proteins (RBPs) or (2) are transcribed in corresponding tissues. Additionally, a CaptureSeq experiment revealed expression of many of our CRS regions in human fetal brain, including 662 novel ones. For selected human and mouse candidate pairs, qRT-PCR and in vitro RNA structure probing supported both shared expression and shared structure despite low abundance and low sequence identity. About 30,000 CRS regions are located near coding or long noncoding RNA genes or within enhancers. Structured (CRS overlapping) enhancer RNAs and extended 3' ends have significantly increased expression levels over their nonstructured counterparts. Our findings of transcribed uncharacterized regulatory regions that contain CRSs support their RNA-mediated functionality. © 2017 Seemann et al.; Published by Cold Spring Harbor Laboratory Press.

  12. Magnetic resonance imaging identification of muscular and ligamentous structures of the female pelvic floor; Identificacao das estruturas musculo-ligamentares do assoalho pelvico feminino na ressonancia magnetica

    Energy Technology Data Exchange (ETDEWEB)

    Bezerra, Maria Rita Lima; Soares, Adriano Fleury F.; Faintuch, Salomao; Goldman, Suzan Menasce; Ajzen, Sergio A.; D' Ippolito, Giuseppe; Szejnfeld, Jacob [Universidade Federal de Sao Paulo (UNIFESP/EPM), Sao Paulo, SP (Brazil). Dept. de Diagnostico por Imagem]. E-mail: mrcfc@ig.com.br; Girao, Manoel [Universidade Federal de Sao Paulo (UNIFESP/EPM), Sao Paulo, SP (Brazil). Dept. de Ginecologia

    2001-12-01

    The objective was to determine the frequency and to assess the interobserver agreement of identification of muscular and ligamentous pelvic floor structures using magnetic resonance imaging. The method: twenty asymptomatic female volunteers (aged 20-80 years old; mean: 50) were submitted to magnetic resonance imaging (1.5 T) examinations of the pelvis. Turbo spin-echo sequences were employed to obtain T1 and T2 weighted images on axial and sagittal planes. Two independent observers evaluated the scans in order to identify the levator ani (coccygeal, pubococcygeal, iliococcygeal and puborectalis muscles), obturatorius internus and urethral sphincter muscles, and the pubovesical and pubourethral ligaments. The frequency and the interobserver agreement of the identification of the anatomical structures were assessed (kappa statistic - {kappa}). The results: the frequency of identification of the structures ranged from 50 to 100%, and was slightly lower for identification of the ligaments. Interobserver agreement was as follows: levator ani and obturatorius internus muscle ({kappa}=1), pubococcygeal ({kappa}=0.62), iliococcygeal ({kappa}=0.86), puborectalis ({kappa}= 0.27), coccygeal ({kappa}=0) and urethral sphincter muscles ({kappa}=1), pubovesical ({kappa}=0.50) and pubourethral ({kappa}=0.58) ligaments. The conclusion: magnetic resonance imaging of the pelvis allowed precise identification of the main muscular and ligamentous pelvic floor structures in most individuals, whereas interobserver agreement was considered good. (author)

  13. An Experimental Study of Structural Identification of Bridges Using the Kinetic Energy Optimization Technique and the Direct Matrix Updating Method

    Directory of Open Access Journals (Sweden)

    Gwanghee Heo

    2016-01-01

    Full Text Available This paper aims to develop an SI (structural identification technique using the KEOT and the DMUM to decide on optimal location of sensors and to update FE model, respectively, which ultimately contributes to a composition of more effective SHM. Owing to the characteristic structural flexing behavior of cable bridges (e.g., cable-stayed bridges and suspension bridges, which makes them vulnerable to any vibration, systematic and continuous structural health monitoring (SHM is pivotal for them. Since it is necessary to select optimal measurement locations with the fewest possible measurements and also to accurately assess the structural state of a bridge for the development of an effective SHM, an SI technique is as much important to accurately determine the modal parameters of the current structure based on the data optimally obtained. In this study, the kinetic energy optimization technique (KEOT was utilized to determine the optimal measurement locations, while the direct matrix updating method (DMUM was utilized for FE model updating. As a result of experiment, the required number of measurement locations derived from KEOT based on the target mode was reduced by approximately 80% compared to the initial number of measurement locations. Moreover, compared to the eigenvalue of the modal experiment, an improved FE model with a margin of error of less than 1% was derived from DMUM. Thus, the SI technique for cable-stayed bridges proposed in this study, which utilizes both KEOT and DMUM, is proven effective in minimizing the number of sensors while accurately determining the structural dynamic characteristics.

  14. Structure and Identification of Solenin: A Novel Fibrous Protein from Bivalve Solen grandis Ligament

    Directory of Open Access Journals (Sweden)

    Jun Meng

    2014-01-01

    Full Text Available Fibrous proteins, which derived from natural sources, have been acting as templates for the production of new materials for decades, and most of them have been modified to improve mechanical performance. Insight into the structures of fibrous proteins is a key step for fabricating of bioinspired materials. Here, we revealed the microstructure of a novel fibrous protein: solenin from Solen grandis ligament and identified the protein by MALDI-TOF-TOF-MS and LC-MS-MS analyses. We found that the protein fiber has no hierarchical structure and is homologous to keratin type II cytoskeletal 1 and type I cytoskeletal 9-like, containing “SGGG,” “SYGSGGG,” “GS,” and “GSS” repeat sequences. Secondary structure analysis by FTIR shows that solenin is composed of 41.8% β-sheet, 16.2% β-turn, 26.5% α-helix, and 9.8% disordered structure. We believe that the β-sheet structure and those repeat sequences which form “glycine loops” may give solenin excellence elastic and flexible properties to withstand tensile stress caused by repeating opening and closing of the shell valves in vivo. This paper contributes a novel fibrous protein for the protein materials world.

  15. Crystal Structure Analysis and the Identification of Distinctive Functional Regions of the Protein Elicitor Mohrip2.

    Science.gov (United States)

    Liu, Mengjie; Duan, Liangwei; Wang, Meifang; Zeng, Hongmei; Liu, Xinqi; Qiu, Dewen

    2016-01-01

    The protein elicitor MoHrip2, which was extracted from Magnaporthe oryzae as an exocrine protein, triggers the tobacco immune system and enhances blast resistance in rice. However, the detailed mechanisms by which MoHrip2 acts as an elicitor remain unclear. Here, we investigated the structure of MoHrip2 to elucidate its functions based on molecular structure. The three-dimensional structure of MoHrip2 was obtained. Overall, the crystal structure formed a β-barrel structure and showed high similarity to the pathogenesis-related (PR) thaumatin superfamily protein thaumatin-like xylanase inhibitor (TL-XI). To investigate the functional regions responsible for MoHrip2 elicitor activities, the full length and eight truncated proteins were expressed in Escherichia coli and were evaluated for elicitor activity in tobacco. Biological function analysis showed that MoHrip2 triggered the defense system against Botrytis cinerea in tobacco. Moreover, only MoHrip2M14 and other fragments containing the 14 amino acids residues in the middle region of the protein showed the elicitor activity of inducing a hypersensitive response and resistance related pathways, which were similar to that of full-length MoHrip2. These results revealed that the central 14 amino acid residues were essential for anti-pathogenic activity.

  16. Crystal Structure Analysis and the Identification of Distinctive Functional Regions of the Protein Elicitor Mohrip2

    Directory of Open Access Journals (Sweden)

    Mengjie Liu

    2016-07-01

    Full Text Available The protein elicitor MoHrip2, which was extracted from Magnaporthe oryzae as an exocrine protein, triggers the tobacco immune system and enhances blast resistance in rice. However, the detailed mechanisms by which MoHrip2 acts as an elicitor remain unclear. Here, we investigated the structure of MoHrip2 to elucidate its functions based on molecular structure. The 3-dimensional structure of MoHrip2 was obtained. Overall, the crystal structure formed a β-barrel structure and showed high similarity to the pathogenesis-related (PR thaumatin superfamily protein thaumatin-like xylanase inhibitor (TL-XI. To investigate the functional regions responsible for MoHrip2 elicitor activities, the full length and 8 truncated proteins were expressed in Escherichia coli and were evaluated for elicitor activity in tobacco. Biological function analysis showed that MoHrip2 triggered the defense system against Botrytis cinerea in tobacco. Moreover, only MoHrip2M14 and other fragments containing the 14 amino acids residues in the middle region of the protein showed the elicitor activity of inducing a hypersensitive response and resistance related pathways, which were similar to that of full-length MoHrip2. These results revealed that the central 14 amino acid residues were essential for anti-pathogenic activity.

  17. On the possibilities of occurrence of structure controlled unconformity-proximal uranium mineralization in Madhawanpalli - Rayalgandi Sector, Srisailam Sub-Basin, Cuddapah Basin, Andhra Pradesh

    International Nuclear Information System (INIS)

    Parashar, K.K.; Srivastava, S.K.; Mukundhan, A.R.; Ramesh Kumar, K.; Achar, K.K.

    2012-01-01

    The northern margin of Srisailam Sub-basin is well known for its potential to host unconformity proximal uranium mineralization and so far three deposits have been established at Lambapur, Peddagattu and Chitrial. Recent exploration in Madhawanpalli-Rayalgandi sector and follow up sub-surface exploration has indicated uranium mineralization in the granites beneath the cover of Srisailam sediments. The host rock is characterized by intense fracturing, brecciation, cataclasism and alterations like chloritization, illitization and silicification signifying the role of basement structures in uranium mineralization near the unconformity surface. (author)

  18. Variability in secondary structure of 18S ribosomal RNA as topological marker for identification of Paramecium species.

    Science.gov (United States)

    Shakoori, Farah R; Tasneem, Fareeda; Al-Ghanim, K; Mahboob, S; Al-Misned, F; Jahan, Nusrat; Shakoori, Abdul Rauf

    2014-12-01

    Besides cytological and molecular applications, Paramecium is being used in water quality assessment and for determination of saprobic levels. An unambiguous identification of these unicellular eukaryotes is not only essential, but its ecological diversity must also be explored in the local environment. 18SrRNA genes of all the strains of Paramecium species isolated from waste water were amplified, cloned and sequenced. Phylogenetic comparison of the nucleotide sequences of these strains with 23 closely related Paramecium species from GenBank Database enabled identification of Paramecium multimicronucleatum and Paramecium jenningsi. Some isolates did not show significant close association with other Paramecium species, and because of their unique position in the phylogenetic tree, they were considered new to the field. In the present report, these isolates are being designated as Paramecium caudatum pakistanicus. In this article, secondary structure of 18SrRNA has also been analyzed as an additional and perhaps more reliable topological marker for species discrimination and for determining possible phylogenetic relationship between the ciliate species. On the basis of comparison of secondary structure of 18SrRNA of various isolated Paramacium strains, and among Paramecium caudatum pakistanicus, Tetrahymena thermophila, Drosophila melanogaster, and Homo sapiens, it can be deduced that variable regions are more helpful in differentiating the species at interspecific level rather than at intraspecific level. It was concluded that V3 was the least variable region in all the organisms, V2 and V7 were the longest expansion segments of D. melanogaster and there was continuous mutational bias towards G.C base pairing in H. sapiens. © 2014 Wiley Periodicals, Inc.

  19. Identification and calibration of the structural model of historical masonry building damaged during the 2016 Italian earthquakes: The case study of Palazzo del Podestà in Montelupone

    Science.gov (United States)

    Catinari, Federico; Pierdicca, Alessio; Clementi, Francesco; Lenci, Stefano

    2017-11-01

    The results of an ambient-vibration based investigation conducted on the "Palazzo del Podesta" in Montelupone (Italy) is presented. The case study was damaged during the 20I6 Italian earthquakes that stroke the central part of the Italy. The assessment procedure includes full-scale ambient vibration testing, modal identification from ambient vibration responses, finite element modeling and dynamic-based identification of the uncertain structural parameters of the model. A very good match between theoretical and experimental modal parameters was reached and the model updating has been performed identifying some structural parameters.

  20. IDENTIFICATION OF WIND LOAD APPLIED TO THREE-DIMENSIONAL STRUCTURES BY VIRTUE OF ITS SIMULATION IN THE WIND TUNNEL

    Directory of Open Access Journals (Sweden)

    Doroshenko Sergey Aleksandrovich

    2012-10-01

    Full Text Available The authors discuss wind loads applied to a set of two buildings. The wind load is simulated with the help of the wind tunnel. In the Russian Federation, special attention is driven to the aerodynamics of high-rise buildings and structures. According to the Russian norms, identification of aerodynamic coefficients for high-rise buildings, as well as the influence of adjacent buildings and structures, is performed on the basis of models of structures exposed to wind impacts simulated in the wind tunnel. This article deals with the results of the wind tunnel test of buildings. The simulation was carried out with the involvement of a model of two twenty-three storied buildings. The experiment was held in a wind tunnel of the closed type at in the Institute of Mechanics of Moscow State University. Data were compared at the zero speed before and after the experiment. LabView software was used to process the output data. Graphs and tables were developed in the Microsoft Excel package. GoogleSketchUp software was used as a visualization tool. The three-dimensional flow formed in the wind tunnel can't be adequately described by solving the two-dimensional problem. The aerodynamic experiment technique is used to analyze the results for eighteen angles of the wind attack.

  1. Spectroscopic Identification of the Carbyne Hydride Structure of the Dehydrogenation Product of Methane Activation by Osmium Cations.

    Science.gov (United States)

    Armentrout, P B; Kuijpers, Stach E J; Lushchikova, Olga V; Hightower, Randy L; Boles, Georgia C; Bakker, Joost M

    2018-04-09

    The present work explores the structures of species formed by dehydrogenation of methane (CH 4 ) and perdeuterated methane (CD 4 ) by the 5d transition metal cation osmium (Os + ). Using infrared multiple photon dissociation (IRMPD) action spectroscopy and density functional theory (DFT), the structures of the [Os,C,2H] + and [Os,C,2D] + products are explored. This study complements previous work on the related species formed by dehydrogenation of methane by four other 5d transition metal cations (M + = Ta + , W + , Ir + , and Pt + ). Osmium cations are formed in a laser ablation source, react with methane pulsed into a reaction channel downstream, and the resulting products spectroscopically characterized through photofragmentation using the Free-Electron Laser for IntraCavity Experiments (FELICE) in the 300-1800 cm -1 range. Photofragmentation was monitored by the loss of H 2 /D 2 . Comparison of the experimental spectra and DFT calculated spectra leads to identification of the ground state carbyne hydride, HOsCH + ( 2 A') as the species formed, as previously postulated theoretically. Further, a full description of the systematic spectroscopic shifts observed for deuterium labeling of these complexes, some of the smallest systems to be studied using IRMPD action spectroscopy, is achieved. A full rotational contour analysis explains the observed linewidths as well as the observation of doublet structures in several bands, consistent with previous observations for HIrCH + ( 2 A'). Graphical Abstract ᅟ.

  2. Targeting acetylcholinesterase: identification of chemical leads by high throughput screening, structure determination and molecular modeling.

    Directory of Open Access Journals (Sweden)

    Lotta Berg

    Full Text Available Acetylcholinesterase (AChE is an essential enzyme that terminates cholinergic transmission by rapid hydrolysis of the neurotransmitter acetylcholine. Compounds inhibiting this enzyme can be used (inter alia to treat cholinergic deficiencies (e.g. in Alzheimer's disease, but may also act as dangerous toxins (e.g. nerve agents such as sarin. Treatment of nerve agent poisoning involves use of antidotes, small molecules capable of reactivating AChE. We have screened a collection of organic molecules to assess their ability to inhibit the enzymatic activity of AChE, aiming to find lead compounds for further optimization leading to drugs with increased efficacy and/or decreased side effects. 124 inhibitors were discovered, with considerable chemical diversity regarding size, polarity, flexibility and charge distribution. An extensive structure determination campaign resulted in a set of crystal structures of protein-ligand complexes. Overall, the ligands have substantial interactions with the peripheral anionic site of AChE, and the majority form additional interactions with the catalytic site (CAS. Reproduction of the bioactive conformation of six of the ligands using molecular docking simulations required modification of the default parameter settings of the docking software. The results show that docking-assisted structure-based design of AChE inhibitors is challenging and requires crystallographic support to obtain reliable results, at least with currently available software. The complex formed between C5685 and Mus musculus AChE (C5685•mAChE is a representative structure for the general binding mode of the determined structures. The CAS binding part of C5685 could not be structurally determined due to a disordered electron density map and the developed docking protocol was used to predict the binding modes of this part of the molecule. We believe that chemical modifications of our discovered inhibitors, biochemical and biophysical

  3. Automated identification of RNA 3D modules with discriminative power in RNA structural alignments

    DEFF Research Database (Denmark)

    Theis, Corinna; Höner zu Siederdissen, Christian; Hofacker, Ivo L.

    2013-01-01

    Recent progress in predicting RNA structure is moving towards filling the 'gap' in 2D RNA structure prediction where, for example, predicted internal loops often form non-canonical base pairs. This is increasingly recognized with the steady increase of known RNA 3D modules. There is a general...... comparative evidence. Subsequently, the modules, initially represented by a graph, are turned into models for the RMDetect program, which allows to test their discriminative power using real and randomized Rfam alignments. An initial extraction of 22495 3D modules in all PDB files results in 977 internal loop...

  4. Large scale identification and categorization of protein sequences using structured logistic regression

    DEFF Research Database (Denmark)

    Pedersen, Bjørn Panella; Ifrim, Georgiana; Liboriussen, Poul

    2014-01-01

    Abstract Background Structured Logistic Regression (SLR) is a newly developed machine learning tool first proposed in the context of text categorization. Current availability of extensive protein sequence databases calls for an automated method to reliably classify sequences and SLR seems well...... problem. Results Using SLR, we have built classifiers to identify and automatically categorize P-type ATPases into one of 11 pre-defined classes. The SLR-classifiers are compared to a Hidden Markov Model approach and shown to be highly accurate and scalable. Representing the bulk of currently known...... for further biochemical characterization and structural analysis....

  5. Systematic identification of non-coding RNA 2,2,7-trimethylguanosine cap structures in Caenorhabditis elegans

    Directory of Open Access Journals (Sweden)

    Skogerbø Geir

    2007-09-01

    Full Text Available Abstract Background The 2,2,7-trimethylguanosine (TMG cap structure is an important functional characteristic of ncRNAs with critical cellular roles, such as some snRNAs. Here we used immunoprecipitation with both K121 and R1131 anti-TMG antibodies to systematically identify the TMG cap structures for all presently characterized ncRNAs in C. elegans. Results The two anti-TMG antibodies precipitated a similar group of the C. elegans ncRNAs. All snRNAs known to have a TMG cap structure were found in the precipitate, indicating that our identification system was efficient. Other ncRNA families related to splicing, such as SL RNAs and Sm Y RNAs, were also found in the precipitate, as were 7 C/D box snoRNAs. Further analysis showed that the SL RNAs and the Sm Y RNAs shared a very similar Sm binding site element (AAU4–5GGA, which sequence composition differed somewhat from those of other U snRNAs. There were also 16 ncRNAs without an Sm binding site element in the precipitate, suggesting that for these ncRNAs, TMG formation may occur independently of Sm proteins. Conclusion Our results showed that most ncRNAs predicted to be transcribed by RNA polymerase II had a TMG cap, while those predicted to be transcribed by RNA plymerase III or located in introns did not have a TMG cap structure. Compared to ncRNAs without a TMG cap, TMG-capped ncRNAs tended to have higher expression levels. Five functionally non-annotated ncRNAs also have a TMG cap structure, which might be helpful for identifying the cellular roles of these ncRNAs.

  6. [Study on identification of wild Dipsacus asper and cultivated Dipsacus asper at different growth years by organization structure].

    Science.gov (United States)

    Yang, Jun; Peng, Hua-Sheng; Xuan, Yan; Qu, Jie

    2012-12-01

    To study the regular pattern of growing development and the structural changes of the main root of Dipsacus asper; Find the basis for distinguishing between wild and cultivated Dipsacus asper as well as identifying cultivated Dipsacus asper at different growth years. Continuous sectional sampling and histological observation was conducted on the main roots of annual and biennial cultivated Dipsacus asper and on the main roots of bolting and non-bolting plants of wild Dipsacus asper; Histological observation was carried out respectively on the main roots of one to four-year-old cultivated Dipsacus asper. It was discovered for the first time that there was structure of growth rings in the main roots of Dipsacus asper. And the ways in which the vessels of the growth rings were arranged differed between wild and cultivated Dipsacus asper, the vessels of growth rings in wild Dipsacus asper were arranged tangentially while those in cultivated Dipsacus asper were arranged as clusters. Pith existed in the upper part of roots of wild Dipsacus asper,while it was not found in the cultivated ones, and this could be adopted as a preliminary method to distinguish the wild Dipsacus asper from cultivatedone. The structures of growth rings in each main root were in consistency from top to bottom, and the thickening of roots mainly depended on the growth of xylem in the first year. There were particular relations and regular patterns between the structure of main roots of one to four-year-old cultivated Dipsacus asper and the ages of their growth, which could serve as the primary basis for identifying their growth years. Methods to distinguish wild Dipsacus asper from cultivated ones at different ages by organization structure are established, which could provide the basis for identification of the medicinal material of Dipsacus asper.

  7. Identification of the smallest structure capable of evoking opsonophagocytic antibodies against Streptococcus pneumoniae type 14

    NARCIS (Netherlands)

    Safari, D.; Dekker, H.A.T.; Joosten, J.A.; Michalik, D.; de Souza, A.C.; Adamo, R.; Lahmann, M.; Oscarson, S.; Kamerling, J.P.|info:eu-repo/dai/nl/070433941; Snippe, H.

    2008-01-01

    Synthetic overlapping oligosaccharide fragments of Streptococcus pneumoniae serotype 14 capsular polysaccharide (Pn14PS), {6)-[β-D-Galp-(14)-]β-D-GlcpNAc-(13)-β-D-Galp-(14)-β-D-Glcp-(1}n, were conjugated to CRM197 protein and injected into mice to determine the smallest immunogenic structure. The

  8. Application of far-infrared spectroscopy to the structural identification of protein materials.

    Science.gov (United States)

    Han, Yanchen; Ling, Shengjie; Qi, Zeming; Shao, Zhengzhong; Chen, Xin

    2018-05-03

    Although far-infrared (IR) spectroscopy has been shown to be a powerful tool to determine peptide structure and to detect structural transitions in peptides, it has been overlooked in the characterization of proteins. Herein, we used far-IR spectroscopy to monitor the structure of four abundant non-bioactive proteins, namely, soybean protein isolate (SPI), pea protein isolate (PPI) and two types of silk fibroins (SFs), domestic Bombyx mori and wild Antheraea pernyi. The two globular proteins SPI and PPI result in broad and weak far-IR bands (between 50 and 700 cm-1), in agreement with those of some other bioactive globular proteins previously studied (lysozyme, myoglobin, hemoglobin, etc.) that generally only have random amino acid sequences. Interestingly, the two SFs, which are characterized by a structure composed of highly repetitive motifs, show several sharp far-IR characteristic absorption peaks. Moreover, some of these characteristic peaks (such as the peaks at 260 and 428 cm-1 in B. mori, and the peaks at 245 and 448 cm-1 in A. pernyi) are sensitive to conformational changes; hence, they can be directly used to monitor conformational transitions in SFs. Furthermore, since SF absorption bands clearly differ from those of globular proteins and different SFs even show distinct adsorption bands, far-IR spectroscopy can be applied to distinguish and determine the specific SF component within protein blends.

  9. Identification of vortex structures in a cohort of 204 intracranial aneurysms.

    Science.gov (United States)

    Varble, Nicole; Trylesinski, Gabriel; Xiang, Jianping; Snyder, Kenneth; Meng, Hui

    2017-05-01

    An intracranial aneurysm (IA) is a cerebrovascular pathology that can lead to death or disability if ruptured. Abnormal wall shear stress (WSS) has been associated with IA growth and rupture, but little is known about the underlying flow physics related to rupture-prone IAs. Previous studies, based on analysis of a few aneurysms or partial views of three-dimensional vortex structures, suggest that rupture is associated with complex vortical flow inside IAs. To further elucidate the relevance of vortical flow in aneurysm pathophysiology, we studied 204 patient IAs (56 ruptured and 148 unruptured). Using objective quantities to identify three-dimensional vortex structures, we investigated the characteristics associated with aneurysm rupture and if these features correlate with previously proposed WSS and morphological characteristics indicative of IA rupture. Based on the Q -criterion definition of a vortex, we quantified the degree of the aneurysmal region occupied by vortex structures using the volume vortex fraction ( vVF ) and the surface vortex fraction ( sVF ). Computational fluid dynamics simulations showed that the sVF , but not the vVF , discriminated ruptured from unruptured aneurysms. Furthermore, we found that the near-wall vortex structures co-localized with regions of inflow jet breakdown, and significantly correlated to previously proposed haemodynamic and morphologic characteristics of ruptured IAs. © 2017 The Author(s).

  10. Identification of time-varying structural dynamic systems - An artificial intelligence approach

    Science.gov (United States)

    Glass, B. J.; Hanagud, S.

    1992-01-01

    An application of the artificial intelligence-derived methodologies of heuristic search and object-oriented programming to the problem of identifying the form of the model and the associated parameters of a time-varying structural dynamic system is presented in this paper. Possible model variations due to changes in boundary conditions or configurations of a structure are organized into a taxonomy of models, and a variant of best-first search is used to identify the model whose simulated response best matches that of the current physical structure. Simulated model responses are verified experimentally. An output-error approach is used in a discontinuous model space, and an equation-error approach is used in the parameter space. The advantages of the AI methods used, compared with conventional programming techniques for implementing knowledge structuring and inheritance, are discussed. Convergence conditions and example problems have been discussed. In the example problem, both the time-varying model and its new parameters have been identified when changes occur.

  11. System identification of smart structures using a wavelet neuro-fuzzy model

    Science.gov (United States)

    Mitchell, Ryan; Kim, Yeesock; El-Korchi, Tahar

    2012-11-01

    This paper proposes a complex model of smart structures equipped with magnetorheological (MR) dampers. Nonlinear behavior of the structure-MR damper systems is represented by the use of a wavelet-based adaptive neuro-fuzzy inference system (WANFIS). The WANFIS is developed through the integration of wavelet transforms, artificial neural networks, and fuzzy logic theory. To evaluate the effectiveness of the WANFIS model, a three-story building employing an MR damper under a variety of natural hazards is investigated. An artificial earthquake is used for training the input-output mapping of the WANFIS model. The artificial earthquake is generated such that the characteristics of a variety of real recorded earthquakes are included. It is demonstrated that this new WANFIS approach is effective in modeling nonlinear behavior of the structure-MR damper system subjected to a variety of disturbances while resulting in shorter training times in comparison with an adaptive neuro-fuzzy inference system (ANFIS) model. Comparison with high fidelity data proves the viability of the proposed approach in a structural health monitoring setting, and it is validated using known earthquake signals such as El-Centro, Kobe, Northridge, and Hachinohe.

  12. System Identification of Civil Engineering Structures using State Space and ARMAV Models

    DEFF Research Database (Denmark)

    Andersen, P.; Kirkegaard, Poul Henning; Brincker, Rune

    In this paper the relations between an ambient excited structural system, represented by an innovation state space system, and the Auto-Regressive Moving Average Vector (ARMAV) model are considered. It is shown how to obtain a multivariate estimate of the ARMAV model from output measurements, usi...

  13. Identification of structural similarities between putative transmission proteins of Polymyxa and Spongospora transmitted bymoviruses and furoviruses.

    Science.gov (United States)

    Dessens, J T; Meyer, M

    1996-01-01

    Comparison of amino acid sequence and hydropathy profiles shows conserved, structural similarities between the capsid readthrough protein of potato mop top virus (transmitted by Spongospora subterranea) and furovirus and bymovirus proteins implicated in transmission by Polymyxa spp. This suggests that these proteins have a common ancestry and are involved in a common biological process: virus transmission by plasmodiophorid fungi.

  14. STRUCTURE IDENTIFICATION OF A TRIMER STILBENOID COMPOUND FROM STEM BARK Hopea nigra (DIPTEROCARPACEAE

    Directory of Open Access Journals (Sweden)

    Sri Atun

    2010-06-01

    Full Text Available Bioactivity as antihephatotoxic directed fractionation of aceton extract from the stem bark of Hopea nigra (Dipterocarpaceae afforded a stilbenoid trimer, namely vaticanol G (1. The structure of this compound were elucidated based on physical and spectroscopic data (UV, IR, MS, 1H and 13C NMR 1D and 2D. Keywords: Vaticanol G; Hopea nigra; antihepatotoxic; Dipterocarpaceae.

  15. Identification of Prospective Science Teachers' Mathematical-Logical Structures in Reference to Magnetism

    Science.gov (United States)

    Yilmaz, Ismail

    2014-01-01

    This paper is a qualitative case study designed to identify prospective science teachers' mathematical-logical structures on the basis of their knowledge and achievement levels in magnetism. The study also made an attempt to reveal the effects of knowledge-level variables and procedural variables, which were considered to be potential…

  16. Assessing local structure motifs using order parameters for motif recognition, interstitial identification, and diffusion path characterization

    Science.gov (United States)

    Zimmermann, Nils E. R.; Horton, Matthew K.; Jain, Anubhav; Haranczyk, Maciej

    2017-11-01

    Structure-property relationships form the basis of many design rules in materials science, including synthesizability and long-term stability of catalysts, control of electrical and optoelectronic behavior in semiconductors as well as the capacity of and transport properties in cathode materials for rechargeable batteries. The immediate atomic environments (i.e., the first coordination shells) of a few atomic sites are often a key factor in achieving a desired property. Some of the most frequently encountered coordination patterns are tetrahedra, octahedra, body and face-centered cubic as well as hexagonal closed packed-like environments. Here, we showcase the usefulness of local order parameters to identify these basic structural motifs in inorganic solid materials by developing classification criteria. We introduce a systematic testing framework, the Einstein crystal test rig, that probes the response of order parameters to distortions in perfect motifs to validate our approach. Subsequently, we highlight three important application cases. First, we map basic crystal structure information of a large materials database in an intuitive manner by screening the Materials Project (MP) database (61,422 compounds) for element-specific motif distributions. Second, we use the structure-motif recognition capabilities to automatically find interstitials in metals, semiconductor, and insulator materials. Our Interstitialcy Finding Tool (InFiT) facilitates high-throughput screenings of defect properties. Third, the order parameters are reliable and compact quantitative structure descriptors for characterizing diffusion hops of intercalants as our example of magnesium in MnO2-spinel indicates. Finally, the tools developed in our work are readily and freely available as software implementations in the pymatgen library, and we expect them to be further applied to machine-learning approaches for emerging applications in materials science.

  17. Occurrence of Domatia as a systematic character

    NARCIS (Netherlands)

    Steenis, van C.G.G.J.

    1967-01-01

    In our Bulletin no 20, pp. 1272-1273, Dr. M. Jacobs made some notes on the nature and occurrence of domatia. His full paper has now appeared (Proc. Kon. Akad. Wet. A’dam C 69, 1966, 275-316, repr. 1-44) and this means to be a great step forward in the study of these peculiar structures, which are

  18. Pyrrolizidine alkaloids: occurrence, biology, and chemical synthesis.

    Science.gov (United States)

    Robertson, Jeremy; Stevens, Kiri

    2017-01-04

    Covering: 2013 up to the end of 2015This review covers the isolation and structure of new pyrrolizidines; pyrrolizidine biosynthesis; biological activity, including the occurrence of pyrrolizidines as toxic components or contaminants in foods and beverages; and formal and total syntheses of naturally-occurring pyrrolizidine alkaloids and closely related non-natural analogues.

  19. Identification and the primary structure of equine alpha-lactalbumin B and C (Equus caballus, Perissodactyla).

    Science.gov (United States)

    Godovac-Zimmermann, J; Shaw, D; Conti, A; McKenzie, H

    1987-04-01

    The presence of two new alpha-lactalbumins has been demonstrated in the colostrum of a single mare (Equus caballus, Persian Arab). They have been designated equine alpha-lactalbumin B and C, and that isolated previously from the milk of Australian horses (English Thoroughbred) as alpha-lactalbumin A. The primary structures of B/C have been determined by automatic Edman degradation of enzymatic cleavage of the oxidized protein. Cyanogen bromide cleavage of S-carbamoyl-methylated protein provided necessary overlapping peptides. Comparison of the sequences of B and C with that of A indicates 3 and 4 amino-acid exchanges, respectively. The phylogenetic difference of equine alpha-lactalbumin B/C from bovine alpha-lactalbumin B is indicated by 39 and 40 amino-acid exchanges, respectively. The structure-function relationship, calcium binding sites and variants of alpha-lactalbumin are discussed.

  20. An application of Pettifor structure maps for the identification of pseudo-binary quasicrystalline intermetallics

    International Nuclear Information System (INIS)

    Ranganathan, S.; Inoue, A.

    2006-01-01

    Quasicrystal-forming ability is considered from the viewpoint of Pettifor maps, where a single phenomenological coordinate, the Mendeleev number, captures the bonding characteristics of elements in forming intermetallics. By considering the largest sized atom as the most important constituent, it is shown that most known ternary and quaternary quasicrystals can be treated as pseudo-binary intermetallics. This also results in a classification of quasicrystals into four structural classes based on the nature of the bond orbital - s, p, d or f - of the large atom with four associated related crystal structures. A colour scheme is introduced to indicate preferences for two types of sites. We propose a new classification of quasicrystals as centred on Li, Mg, Al, Ga, Ca, Sc, Y, Ti, Zr, Hf and rare earth elements, as they are the largest atoms in the constituent quasicrystals in contrast to the conventional classification based on majority species

  1. An application of Pettifor structure maps for the identification of pseudo-binary quasicrystalline intermetallics

    Energy Technology Data Exchange (ETDEWEB)

    Ranganathan, S. [Department of Metallurgy, Indian Institute of Science, CV Raman Avenue, Bangalore 560012, Karnataka (India) and Institute for Materials Research, Tohoku University, Sendai 9808577 (Japan)]. E-mail: rangu@met.iisc.ernet.in; Inoue, A. [Institute for Materials Research, Tohoku University, Sendai 9808577 (Japan)

    2006-08-15

    Quasicrystal-forming ability is considered from the viewpoint of Pettifor maps, where a single phenomenological coordinate, the Mendeleev number, captures the bonding characteristics of elements in forming intermetallics. By considering the largest sized atom as the most important constituent, it is shown that most known ternary and quaternary quasicrystals can be treated as pseudo-binary intermetallics. This also results in a classification of quasicrystals into four structural classes based on the nature of the bond orbital - s, p, d or f - of the large atom with four associated related crystal structures. A colour scheme is introduced to indicate preferences for two types of sites. We propose a new classification of quasicrystals as centred on Li, Mg, Al, Ga, Ca, Sc, Y, Ti, Zr, Hf and rare earth elements, as they are the largest atoms in the constituent quasicrystals in contrast to the conventional classification based on majority species.

  2. IDENTIFICATION OF MODAL PARAMETERS OF VIBRATING STRUCTURES WITH UNKNOWN ORSTOCHASTIC EXCITATION

    OpenAIRE

    Amaro Baldeón, Roberto; Gardel Kurka, Paulo

    2014-01-01

    The Vector Autoregressive Moving Average (VARMA) Model is used to identify dynamical characteristics of a structural system in the presence of noise. In order to estimate the parameters of the VARMA Model, the Spliid’s fast algorithm is used. To determine the modal parameters the companion matrix is built with the autoregressive part of the VARMA Model. The performance of this method here discussed is presented by means of simulations, using three degrees of freedom mass-dampingstiffness vibr...

  3. Identification of kin structure among Guam rail founders: a comparison of pedigrees and DNA profiles

    Science.gov (United States)

    Haig, Susan M.; Ballou, J.D.; Casna, N.J.

    1994-01-01

    Kin structure among founders can have a significant effect on subsequent population structure. Here we use the correlation between DNA profile similarity and relatedness calculated from pedigrees to test hypotheses regarding kin structure among founders to the captive Guam rail (Rallus owstoni) population. Five different pedigrees were generated under the following hypotheses: (i) founders are unrelated; (ii) founders are unrelated except for same-nest chicks; (iii) founders from the same major site are siblings; (iv) founders from the same local site are siblings; and (v) founders are related as defined by a UPGMA cluster analysis of DNA similarity data. Relatedness values from pedigrees 1, 2 and 5 had the highest correlation with DNA similarity but the correlation between relatedness and similarity were not significantly different among pedigrees. Pedigree 5 resulted in the highest correlation overall when using only relatedness values that changed as a result of different founder hypotheses. Thus, founders were assigned relatedness based on pedigree 5 because it had the highest correlations with DNA similarity, was the most conservative approach, and incorporated all field data. The analyses indicated that estimating relatedness using DNA profiles remains problematic, therefore we compared mean kinship, a measure of genetic importance, with mean DNA profile similarity to determine if genetic importance among individuals could be determined via use of DNA profiles alone. The significant correlation suggests this method may provide more information about population structure than was previously thought. Thus, DNA profiles can provide a reasonable explanation for founder relatedness and mean DNA profile similarity may be helpful in determining relative genetic importance of individuals when detailed pedigrees are absent.

  4. Assessing Local Structure Motifs Using Order Parameters for Motif Recognition, Interstitial Identification, and Diffusion Path Characterization

    Directory of Open Access Journals (Sweden)

    Nils E. R. Zimmermann

    2017-11-01

    Full Text Available Structure–property relationships form the basis of many design rules in materials science, including synthesizability and long-term stability of catalysts, control of electrical and optoelectronic behavior in semiconductors, as well as the capacity of and transport properties in cathode materials for rechargeable batteries. The immediate atomic environments (i.e., the first coordination shells of a few atomic sites are often a key factor in achieving a desired property. Some of the most frequently encountered coordination patterns are tetrahedra, octahedra, body and face-centered cubic as well as hexagonal close packed-like environments. Here, we showcase the usefulness of local order parameters to identify these basic structural motifs in inorganic solid materials by developing classification criteria. We introduce a systematic testing framework, the Einstein crystal test rig, that probes the response of order parameters to distortions in perfect motifs to validate our approach. Subsequently, we highlight three important application cases. First, we map basic crystal structure information of a large materials database in an intuitive manner by screening the Materials Project (MP database (61,422 compounds for element-specific motif distributions. Second, we use the structure-motif recognition capabilities to automatically find interstitials in metals, semiconductor, and insulator materials. Our Interstitialcy Finding Tool (InFiT facilitates high-throughput screenings of defect properties. Third, the order parameters are reliable and compact quantitative structure descriptors for characterizing diffusion hops of intercalants as our example of magnesium in MnO2-spinel indicates. Finally, the tools developed in our work are readily and freely available as software implementations in the pymatgen library, and we expect them to be further applied to machine-learning approaches for emerging applications in materials science.

  5. Identification of eight novel coagulation factor XIII subunit A mutations: implied consequences for structure and function.

    Science.gov (United States)

    Ivaskevicius, Vytautas; Biswas, Arijit; Bevans, Carville; Schroeder, Verena; Kohler, Hans Peter; Rott, Hannelore; Halimeh, Susan; Petrides, Petro E; Lenk, Harald; Krause, Manuele; Miterski, Bruno; Harbrecht, Ursula; Oldenburg, Johannes

    2010-06-01

    Severe hereditary coagulation factor XIII deficiency is a rare homozygous bleeding disorder affecting one person in every two million individuals. In contrast, heterozygous factor XIII deficiency is more common, but usually not associated with severe hemorrhage such as intracranial bleeding or hemarthrosis. In most cases, the disease is caused by F13A gene mutations. Causative mutations associated with the F13B gene are rarer. We analyzed ten index patients and three relatives for factor XIII activity using a photometric assay and sequenced their F13A and F13B genes. Additionally, structural analysis of the wild-type protein structure from a previously reported X-ray crystallographic model identified potential structural and functional effects of the missense mutations. All individuals except one were heterozygous for factor XIIIA mutations (average factor XIII activity 51%), while the remaining homozygous individual was found to have severe factor XIII deficiency (<5% of normal factor XIII activity). Eight of the 12 heterozygous patients exhibited a bleeding tendency upon provocation. The identified missense (Pro289Arg, Arg611His, Asp668Gly) and nonsense (Gly390X, Trp664X) mutations are causative for factor XIII deficiency. A Gly592Ser variant identified in three unrelated index patients, as well as in 200 healthy controls (minor allele frequency 0.005), and two further Tyr167Cys and Arg540Gln variants, represent possible candidates for rare F13A gene polymorphisms since they apparently do not have a significant influence on the structure of the factor XIIIA protein. Future in vitro expression studies of the factor XIII mutations are required to confirm their pathological mechanisms.

  6. Comparing methodologies for structural identification and fatigue life prediction of a highway bridge

    OpenAIRE

    Pai, Sai Ganesh Sarvotham; Nussbaumer, Alain; Smith, Ian F. C.

    2018-01-01

    Accurate measurement-data interpretation leads to increased understanding of structural behavior and enhanced asset-management decision making. In this paper, four data-interpretation methodologies, residual minimization, traditional Bayesian model updating, modified Bayesian model updating (with an L∞-norm-based Gaussian likelihood function), and error-domain model falsification (EDMF), a method that rejects models that have unlikely differences between predictions and measurements, are comp...

  7. Comparing Structural Identification Methodologies for Fatigue Life Prediction of a Highway Bridge

    OpenAIRE

    Pai, Sai G.S.; Nussbaumer, Alain; Smith, Ian F.C.

    2018-01-01

    Accurate measurement-data interpretation leads to increased understanding of structural behavior and enhanced asset-management decision making. In this paper, four data-interpretation methodologies, residual minimization, traditional Bayesian model updating, modified Bayesian model updating (with an L∞-norm-based Gaussian likelihood function), and error-domain model falsification (EDMF), a method that rejects models that have unlikely differences between predictions and measurements, are comp...

  8. Identification and characterization of a novel non-structural protein of bluetongue virus.

    Directory of Open Access Journals (Sweden)

    Maxime Ratinier

    2011-12-01

    Full Text Available Bluetongue virus (BTV is the causative agent of a major disease of livestock (bluetongue. For over two decades, it has been widely accepted that the 10 segments of the dsRNA genome of BTV encode for 7 structural and 3 non-structural proteins. The non-structural proteins (NS1, NS2, NS3/NS3a play different key roles during the viral replication cycle. In this study we show that BTV expresses a fourth non-structural protein (that we designated NS4 encoded by an open reading frame in segment 9 overlapping the open reading frame encoding VP6. NS4 is 77-79 amino acid residues in length and highly conserved among several BTV serotypes/strains. NS4 was expressed early post-infection and localized in the nucleoli of BTV infected cells. By reverse genetics, we showed that NS4 is dispensable for BTV replication in vitro, both in mammalian and insect cells, and does not affect viral virulence in murine models of bluetongue infection. Interestingly, NS4 conferred a replication advantage to BTV-8, but not to BTV-1, in cells in an interferon (IFN-induced antiviral state. However, the BTV-1 NS4 conferred a replication advantage both to a BTV-8 reassortant containing the entire segment 9 of BTV-1 and to a BTV-8 mutant with the NS4 identical to the homologous BTV-1 protein. Collectively, this study suggests that NS4 plays an important role in virus-host interaction and is one of the mechanisms played, at least by BTV-8, to counteract the antiviral response of the host. In addition, the distinct nucleolar localization of NS4, being expressed by a virus that replicates exclusively in the cytoplasm, offers new avenues to investigate the multiple roles played by the nucleolus in the biology of the cell.

  9. Identification of Protein Complexes Using Weighted PageRank-Nibble Algorithm and Core-Attachment Structure.

    Science.gov (United States)

    Peng, Wei; Wang, Jianxin; Zhao, Bihai; Wang, Lusheng

    2015-01-01

    Protein complexes play a significant role in understanding the underlying mechanism of most cellular functions. Recently, many researchers have explored computational methods to identify protein complexes from protein-protein interaction (PPI) networks. One group of researchers focus on detecting local dense subgraphs which correspond to protein complexes by considering local neighbors. The drawback of this kind of approach is that the global information of the networks is ignored. Some methods such as Markov Clustering algorithm (MCL), PageRank-Nibble are proposed to find protein complexes based on random walk technique which can exploit the global structure of networks. However, these methods ignore the inherent core-attachment structure of protein complexes and treat adjacent node equally. In this paper, we design a weighted PageRank-Nibble algorithm which assigns each adjacent node with different probability, and propose a novel method named WPNCA to detect protein complex from PPI networks by using weighted PageRank-Nibble algorithm and core-attachment structure. Firstly, WPNCA partitions the PPI networks into multiple dense clusters by using weighted PageRank-Nibble algorithm. Then the cores of these clusters are detected and the rest of proteins in the clusters will be selected as attachments to form the final predicted protein complexes. The experiments on yeast data show that WPNCA outperforms the existing methods in terms of both accuracy and p-value. The software for WPNCA is available at "http://netlab.csu.edu.cn/bioinfomatics/weipeng/WPNCA/download.html".

  10. Integration of ligand and structure-based virtual screening for identification of leading anabolic steroids.

    Science.gov (United States)

    Alvarez-Ginarte, Yoanna María; Montero-Cabrera, Luis Alberto; García-de la Vega, José Manuel; Bencomo-Martínez, Alberto; Pupo, Amaury; Agramonte-Delgado, Alina; Marrero-Ponce, Yovani; Ruiz-García, José Alberto; Mikosch, Hans

    2013-11-01

    Parallel ligand- and structure-based virtual screenings of 269 steroids with anabolic activity evaluated in vivo were performed. The quantitative structure-activity relationship (QSAR) model expressed by selected descriptors as the octanol-water partition coefficient, the molar volume and the quantum mechanical calculated charge values on atoms C1, C2, C5, C9, C10, C14 and C17 of the steroid skeleton, expresses structural features of anabolic steroids (AS) contributing to the transport and steroid-receptor interaction. On the other hand, computational simulations of a candidate ligand binding to a receptor study (a "docking" procedure) predict the association of these AS with the human androgen receptor (AR). Fourteen compounds were identified as lead; the most potent was the 7α-methylestr-4-en-3, 17-dione. It was concluded that a good anabolic activity requires hydrogen bonding interactions between both Arg752 and Gln711 residues in the cycles A with O3 atom of the steroid and either Asn705 and Thr877 residues in the cycles D of steroid with O17 atom. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Identification of Capacitive MEMS Accelerometer Structure Parameters for Human Body Dynamics Measurements

    Directory of Open Access Journals (Sweden)

    Vincas Benevicius

    2013-08-01

    Full Text Available Due to their small size, low weight, low cost and low energy consumption, MEMS accelerometers have achieved great commercial success in recent decades. The aim of this research work is to identify a MEMS accelerometer structure for human body dynamics measurements. Photogrammetry was used in order to measure possible maximum accelerations of human body parts and the bandwidth of the digital acceleration signal. As the primary structure the capacitive accelerometer configuration is chosen in such a way that sensing part measures on all three axes as it is 3D accelerometer and sensitivity on each axis is equal. Hill climbing optimization was used to find the structure parameters. Proof-mass displacements were simulated for all the acceleration range that was given by the optimization problem constraints. The final model was constructed in Comsol Multiphysics. Eigenfrequencies were calculated and model’s response was found, when vibration stand displacement data was fed into the model as the base excitation law. Model output comparison with experimental data was conducted for all excitation frequencies used during the experiments.

  12. Structures of phlebovirus glycoprotein Gn and identification of a neutralizing antibody epitope.

    Science.gov (United States)

    Wu, Yan; Zhu, Yaohua; Gao, Feng; Jiao, Yongjun; Oladejo, Babayemi O; Chai, Yan; Bi, Yuhai; Lu, Shan; Dong, Mengqiu; Zhang, Chang; Huang, Guangmei; Wong, Gary; Li, Na; Zhang, Yanfang; Li, Yan; Feng, Wen-Hai; Shi, Yi; Liang, Mifang; Zhang, Rongguang; Qi, Jianxun; Gao, George F

    2017-09-05

    Severe fever with thrombocytopenia syndrome virus (SFTSV) and Rift Valley fever virus (RVFV) are two arthropod-borne phleboviruses in the Bunyaviridae family, which cause severe illness in humans and animals. Glycoprotein N (Gn) is one of the envelope proteins on the virus surface and is a major antigenic component. Despite its importance for virus entry and fusion, the molecular features of the phleboviruse Gn were unknown. Here, we present the crystal structures of the Gn head domain from both SFTSV and RVFV, which display a similar compact triangular shape overall, while the three subdomains (domains I, II, and III) making up the Gn head display different arrangements. Ten cysteines in the Gn stem region are conserved among phleboviruses, four of which are responsible for Gn dimerization, as revealed in this study, and they are highly conserved for all members in Bunyaviridae Therefore, we propose an anchoring mode on the viral surface. The complex structure of the SFTSV Gn head and human neutralizing antibody MAb 4-5 reveals that helices α6 in subdomain III is the key component for neutralization. Importantly, the structure indicates that domain III is an ideal region recognized by specific neutralizing antibodies, while domain II is probably recognized by broadly neutralizing antibodies. Collectively, Gn is a desirable vaccine target, and our data provide a molecular basis for the rational design of vaccines against the diseases caused by phleboviruses and a model for bunyavirus Gn embedding on the viral surface.

  13. Identification of the underlying factor structure of the Derriford Appearance Scale 24

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    Timothy P. Moss

    2015-07-01

    Full Text Available Background. The Derriford Appearance Scale24 (DAS24 is a widely used measure of distress and dysfunction in relation to self-consciousness of appearance. It has been used in clinical and research settings, and translated into numerous European and Asian languages. Hitherto, no study has conducted an analysis to determine the underlying factor structure of the scale.Methods. A large (n = 1,265 sample of community and hospital patients with a visible difference were recruited face to face or by post, and completed the DAS24.Results. A two factor solution was generated. An evaluation of the congruence of the factor solutions on each of the the hospital and the community samples using Tucker’s Coefficient of Congruence (rc = .979 and confirmatory factor analysis, which demonstrated a consistent factor structure. A main factor, general self consciousness (GSC, was represented by 18 items. Six items comprised a second factor, sexual and body self-consciousness (SBSC. The SBSC scale demonstrated greater sensitivity and specificity in identifying distress for sexually significant areas of the body.Discussion. The factor structure of the DAS24 facilitates a more nuanced interpretation of scores using this scale. Two conceptually and statistically coherent sub-scales were identified. The SBSC sub-scale offers a means of identifying distress and dysfunction around sexually significant areas of the body not previously possible with this scale.

  14. STRUCTURAL CHARACTERIZATION OF VOLCANIC ASH OF THE NEVADO DEL RUIZ: ZEOLITE PHASE IDENTIFICATION

    Directory of Open Access Journals (Sweden)

    Heiddy P. Quiroz

    2014-08-01

    Full Text Available This paper presents a study of the structural properties obtained from volcanic ash from Nevado del Ruiz located in the Central Range of Andes - Colombia. The volcanic ash samples were subjected to hydration processes and heat treatments in situ during characterization stage material. During the hydration process, which consisted of introducing 2.4875 ± 0.0002g of volcanic ash in 20ml of water for 48 hours, the organic fraction present was removed from the particulate suspension in the aqueous medium. From measurements of X-ray diffraction (XRD, it was observed, that the temperature variations between 323 and 673 K influence the phase formation of zeolite with structures Heulandite -Ca, Stellerita and gmelinite. XRD measurements were performed in vacuum and atmospheric pressure. X'pert Highscore Plus program and simulation Rietveld refinement were used for to obtain the structures of each of the phases. It was found, using the Scherrer equation, that crystallite sizes (Δ (2θ are influenced by changes crystal-chemical caused by hydration, heat treatment and pressure conditions during the characterization. A variation of Δ ( 2θ between 37 and 106.9 nm from XRD measurements was found. It was determined that from 423K in the sample of un-hydrated volcanic ash, the formation of zeolite Stellerita presents with a stable phase up to 673 K.

  15. Identification of candidate structured RNAs in the marine organism 'Candidatus Pelagibacter ubique'

    Directory of Open Access Journals (Sweden)

    Schwalbach Michael S

    2009-06-01

    Full Text Available Abstract Background Metagenomic sequence data are proving to be a vast resource for the discovery of biological components. Yet analysis of this data to identify functional RNAs lags behind efforts to characterize protein diversity. The genome of 'Candidatus Pelagibacter ubique' HTCC 1062 is the closest match for approximately 20% of marine metagenomic sequence reads. It is also small, contains little non-coding DNA, and has strikingly low GC content. Results To aid the discovery of RNA motifs within the marine metagenome we exploited the genomic properties of 'Cand. P. ubique' by targeting our search to long intergenic regions (IGRs with relatively high GC content. Analysis of known RNAs (rRNA, tRNA, riboswitches etc. shows that structured RNAs are significantly enriched in such IGRs. To identify additional candidate structured RNAs, we examined other IGRs with similar characteristics from 'Cand. P. ubique' using comparative genomics approaches in conjunction with marine metagenomic data. Employing this strategy, we discovered four candidate structured RNAs including a new riboswitch class as well as three additional likely cis-regulatory elements that precede genes encoding ribosomal proteins S2 and S12, and the cytoplasmic protein component of the signal recognition particle. We also describe four additional potential RNA motifs with few or no examples occurring outside the metagenomic data. Conclusion This work begins the process of identifying functional RNA motifs present in the metagenomic data and illustrates how existing completed genomes may be used to aid in this task.

  16. Identification of structures, systems, and components important to safety at the potential repository at Yucca Mountain

    International Nuclear Information System (INIS)

    Hartman, D.J.; Miller, D.D.; Klamerus, L.J.

    1991-10-01

    This study recommends which structures, systems, and components of the potential repository at Yucca Mountain are important to safety. The assessment was completed in April 1990 and uses the reference repository configuration in the Site Characterization Plan Conceptual Design Report and follows the methodology required at that time by DOE Procedure AP6.10-Q. Failures of repository items during the preclosure period are evaluated to determine the potential offsite radiation doses and associated probabilities. Items are important to safety if, in the event they fail to perform their intended function, an accident could result which causes a dose commitment greater than 0.5 rem to the whole body or any organ of an individual in an unrestricted area. This study recommends that these repository items include the structures that house spent fuel and high-level waste, the associated filtered ventilation exhaust systems, certain waste- handling equipment, the waste containers, the waste treatment building structure, the underground waste transporters, and other items listed in this report. This work was completed April 1990. 27 refs., 7 figs., 9 tabs

  17. Identification of Large-Scale Structure Fluctuations in IC Engines using POD-Based Conditional Averaging

    Directory of Open Access Journals (Sweden)

    Buhl Stefan

    2016-01-01

    Full Text Available Cycle-to-Cycle Variations (CCV in IC engines is a well-known phenomenon and the definition and quantification is well-established for global quantities such as the mean pressure. On the other hand, the definition of CCV for local quantities, e.g. the velocity or the mixture distribution, is less straightforward. This paper proposes a new method to identify and calculate cyclic variations of the flow field in IC engines emphasizing the different contributions from large-scale energetic (coherent structures, identified by a combination of Proper Orthogonal Decomposition (POD and conditional averaging, and small-scale fluctuations. Suitable subsets required for the conditional averaging are derived from combinations of the the POD coefficients of the second and third mode. Within each subset, the velocity is averaged and these averages are compared to the ensemble-averaged velocity field, which is based on all cycles. The resulting difference of the subset-average and the global-average is identified as a cyclic fluctuation of the coherent structures. Then, within each subset, remaining fluctuations are obtained from the difference between the instantaneous fields and the corresponding subset average. The proposed methodology is tested for two data sets obtained from scale resolving engine simulations. For the first test case, the numerical database consists of 208 independent samples of a simplified engine geometry. For the second case, 120 cycles for the well-established Transparent Combustion Chamber (TCC benchmark engine are considered. For both applications, the suitability of the method to identify the two contributions to CCV is discussed and the results are directly linked to the observed flow field structures.

  18. Identification of antibody glycosylation structures that predict monoclonal antibody Fc-effector function.

    Science.gov (United States)

    Chung, Amy W; Crispin, Max; Pritchard, Laura; Robinson, Hannah; Gorny, Miroslaw K; Yu, Xiaojie; Bailey-Kellogg, Chris; Ackerman, Margaret E; Scanlan, Chris; Zolla-Pazner, Susan; Alter, Galit

    2014-11-13

    To determine monoclonal antibody (mAb) features that predict fragment crystalizable (Fc)-mediated effector functions against HIV. Monoclonal antibodies, derived from Chinese hamster ovary cells or Epstein-Barr virus-immortalized mouse heteromyelomas, with specificity to key regions of the HIV envelope including gp120-V2, gp120-V3 loop, gp120-CD4(+) binding site, and gp41-specific antibodies, were functionally profiled to determine the relative contribution of the variable and constant domain features of the antibodies in driving robust Fc-effector functions. Each mAb was assayed for antibody-binding affinity to gp140(SR162), antibody-dependent cellular cytotoxicity (ADCC), antibody-dependent cellular phagocytosis (ADCP) and for the ability to bind to FcγRIIa, FcγRIIb and FcγRIIIa receptors. Antibody glycan profiles were determined by HPLC. Neither the specificity nor the affinity of the mAbs determined the potency of Fc-effector function. FcγRIIIa binding strongly predicted ADCC and decreased galactose content inversely correlated with ADCP, whereas N-glycolylneuraminic acid-containing structures exhibited enhanced ADCP. Additionally, the bi-antenary glycan arm onto which galactose was added predicted enhanced binding to FcγRIIIa and ADCC activity, independent of the specificity of the mAb. Our studies point to the specific Fc-glycan structures that can selectively promote Fc-effector functions independently of the antibody specificity. Furthermore, we demonstrated antibody glycan structures associated with enhanced ADCP activity, an emerging Fc-effector function that may aid in the control and clearance of HIV infection.

  19. Cloning of the Lentinula edodes B mating-type locus and identification of the genetic structure controlling B mating.

    Science.gov (United States)

    Wu, Lin; van Peer, Arend; Song, Wenhua; Wang, Hong; Chen, Mingjie; Tan, Qi; Song, Chunyan; Zhang, Meiyan; Bao, Dapeng

    2013-12-01

    During the life cycle of heterothallic tetrapolar Agaricomycetes such as Lentinula edodes (Berk.) Pegler, the mating type system, composed of unlinked A and B loci, plays a vital role in controlling sexual development and resulting formation of the fruit body. L. edodes is produced worldwide for consumption and medicinal purposes, and understanding its sexual development is therefore of great importance. A considerable amount of mating type factors has been indicated over the past decades but few genes have actually been identified, and no complete genetic structures of L. edodes B mating-type loci are available. In this study, we cloned the matB regions from two mating compatible L. edodes strains, 939P26 and 939P42. Four pheromone receptors were identified on each new matB region, together with three and four pheromone precursor genes in the respective strains. Gene polymorphism, phylogenetic analysis and distribution of pheromone receptors and pheromone precursors clearly indicate a bipartite matB locus, each sublocus containing a pheromone receptor and one or two pheromone precursors. Detailed sequence comparisons of genetic structures between the matB regions of strains 939P42, 939P26 and a previously reported strain SUP2 further supported this model and allowed identification of the B mating type subloci borders. Mating studies confirmed the control of B mating by the identified pheromone receptors and pheromones in L. edodes. © 2013 Elsevier B.V. All rights reserved.

  20. Identification of structural markers for vitamin B12 and other corrinoid derivatives in solution using FTIR spectroscopy

    International Nuclear Information System (INIS)

    Taraszka, K.S.; Chen, Eefei; Metzger, T.; Chance, M.R.

    1991-01-01

    The identification of structural markers for B 12 /protein interactions is crucial to a complete understanding of vitamin B 12 transport and metabolic reaction mechanisms of B 12 coenzymes. Fourier transform infrared spectroscopy can provide direct measurements of changes in the side chains and corrin ring resulting from B 12 /protein interactions. Using FTIR spectroscopy in various solvent systems, the authors have identified structural markers for corrinoids in the physiological state. They assign the major band (denoted B), which occurs at ca. 1,630 cm -1 in D 2 O and ca. 1675 cm -1 in ethanol, to the amide I C double-bond stretching mode of the propionamide side chains of the corrin ring. The lower frequency of band B in D 2 O versus ethanol is due to the greater hydrogen-bonding properties of D 2 O that stabilize the charged amide resonance form. Since the propionamides are known to be important in protein binding, band B is a suitable marker for monitoring the interaction of these side chains with proteins. They assign bands at ca. 1,575 and 1,545 cm -1 (denoted C and D) as breathing modes of the corrin ring on the basis of the bands' solvent independence and their sensitivity to changes in axial ligation

  1. Temperature Identification in the Structural Elements of Non-Contacting Face Seals by Using Trefftz Functions

    Directory of Open Access Journals (Sweden)

    Anna PAWIŃSKA

    2014-12-01

    Full Text Available Phenomena of the heat transfer in non-contacting face seals was described by partial differential equation of the second order and boundary conditions. In this way, the mathematical model was developed for the sealing rings. The distributions of temperature in the structural elements was obtained by the Trefftz method. It is a simple method of solving direct and inverse problems described by a homogeneous or an inhomogeneous partial differential equation. The main idea of the method is to determine functions satisfying a given differential equation (Trefftz functions and to fit the linear combination of them to the governing boundary conditions.

  2. Isolation and structural identification of a novel minoxidil analogue in an illegal dietary supplement: triaminodil.

    Science.gov (United States)

    Lee, Ji Hyun; Park, Han Na; Park, Hyoung Joon; Kim, Nam Sook; Park, Sung-Kwan; Lee, Jongkook; Baek, Sun Young

    2018-01-01

    A new minoxidil analogue was detected in an illegal dietary supplement advertised as a hair-growth treatment. The analogue was identified using ultra-performance liquid chromatography (UPLC), high-resolution mass spectrometry (LC-HR-MS) and nuclear magnetic resonance (NMR) spectroscopy. The compound was structurally elucidated as a minoxidil analogue in which the piperidinyl group of minoxidil was replaced with a pyrrolidinyl group corresponding to a molecular formula of C 8 H 13 N 5 O. The new analogue has been named triaminodil. As this is the first report of the compound, there are no chemical, toxicology or pharmacological data available.

  3. Identification of Persistent RNA-DNA Hybrid Structures within the Origin of Replication of Human Cytomegalovirus

    OpenAIRE

    Prichard, Mark N.; Jairath, Sanju; Penfold, Mark E. T.; Jeor, Stephen St.; Bohlman, Marlene C.; Pari, Gregory S.

    1998-01-01

    Human cytomegalovirus (HCMV) lytic-phase DNA replication initiates at the cis-acting origin of replication, oriLyt. oriLyt is a structurally complex region containing repeat elements and transcription factor binding sites. We identified two site-specific alkali-labile regions within oriLyt which flank an alkali-resistant DNA segment. These alkali-sensitive regions were the result of the degradation of two RNA species embedded within oriLyt and covalently linked to viral DNA. The virus-associa...

  4. High-order dynamic modeling and parameter identification of structural discontinuities in Timoshenko beams by using reflection coefficients

    Science.gov (United States)

    Fan, Qiang; Huang, Zhenyu; Zhang, Bing; Chen, Dayue

    2013-02-01

    Properties of discontinuities, such as bolt joints and cracks in the waveguide structures, are difficult to evaluate by either analytical or numerical methods due to the complexity and uncertainty of the discontinuities. In this paper, the discontinuity in a Timoshenko beam is modeled with high-order parameters and then these parameters are identified by using reflection coefficients at the discontinuity. The high-order model is composed of several one-order sub-models in series and each sub-model consists of inertia, stiffness and damping components in parallel. The order of the discontinuity model is determined based on the characteristics of the reflection coefficient curve and the accuracy requirement of the dynamic modeling. The model parameters are identified through the least-square fitting iteration method, of which the undetermined model parameters are updated in iteration to fit the dynamic reflection coefficient curve with the wave-based one. By using the spectral super-element method (SSEM), simulation cases, including one-order discontinuities on infinite- and finite-beams and a two-order discontinuity on an infinite beam, were employed to evaluate both the accuracy of the discontinuity model and the effectiveness of the identification method. For practical considerations, effects of measurement noise on the discontinuity parameter identification are investigated by adding different levels of noise to the simulated data. The simulation results were then validated by the corresponding experiments. Both the simulation and experimental results show that (1) the one-order discontinuities can be identified accurately with the maximum errors of 6.8% and 8.7%, respectively; (2) and the high-order discontinuities can be identified with the maximum errors of 15.8% and 16.2%, respectively; and (3) the high-order model can predict the complex discontinuity much more accurately than the one-order discontinuity model.

  5. Profitability Identification of National Banking Through Credit, Capital, Capital Structure, Efficiency, and Risk Level

    Directory of Open Access Journals (Sweden)

    Sugeng Haryanto

    2016-04-01

    Full Text Available This study aims to analyze the influence of credit, bank capital, capital structure, efficiency and risk toward the profitability in banking industry. Bank has an important role in the economy in Indonesia in 2014. The purposive sampling technique was used in this study to filter the samples according to several criteria such as being public at least in 2008, and publicly released the financial statement from 2008-2013. The total sample of 25 banks. Multiple regression technique was used in this study to analyze the data. The results show that credit, bank capital, and capital structure positively influence the profitability. This result supported by the previous research. The other finding shows that efficiency and risk have significantly negative effect on profitability. Bangking has an 80 percent market share in the financing of intermediation function of the entire financial system.Penelitian bertujuan menganalisis pengaruh antara kredit, permodalan bank, struktur modal, efisiensi dan risiko terhadap profitabilitas pada industri perbankan. Bank mempunyai peran penting dalam ekonomi Indonesia 2014. Teknik sampling penelitian ini adalah purposive sampling, dengan kriteria bank bank telah go public sebelum tahun 2008, mempublikasikan laporan keuangan tahun 2008-2013. Jumlah sampel sebanyak 25 bank. Teknik analisis yang digunakan regresi linier berganda. Hasil penelitian menunjukkan bahwa kredit, permodalan bank dan struktur modal berpengaruh terhadap profitabilitas dengan arah positif. Hasil lainnya adalah variabel efisiensi dan risiko berpengaruh signifikan dengan arah negatif terhadap profitabilitas. Perbankan memiliki market share 80 persen dalam sistem keuangan.JEL Classification: G3, G32

  6. Identification of the elementary structural units of the DNA damage response.

    Science.gov (United States)

    Natale, Francesco; Rapp, Alexander; Yu, Wei; Maiser, Andreas; Harz, Hartmann; Scholl, Annina; Grulich, Stephan; Anton, Tobias; Hörl, David; Chen, Wei; Durante, Marco; Taucher-Scholz, Gisela; Leonhardt, Heinrich; Cardoso, M Cristina

    2017-06-12

    Histone H2AX phosphorylation is an early signalling event triggered by DNA double-strand breaks (DSBs). To elucidate the elementary units of phospho-H2AX-labelled chromatin, we integrate super-resolution microscopy of phospho-H2AX during DNA repair in human cells with genome-wide sequencing analyses. Here we identify phospho-H2AX chromatin domains in the nanometre range with median length of ∼75 kb. Correlation analysis with over 60 genomic features shows a time-dependent euchromatin-to-heterochromatin repair trend. After X-ray or CRISPR-Cas9-mediated DSBs, phospho-H2AX-labelled heterochromatin exhibits DNA decondensation while retaining heterochromatic histone marks, indicating that chromatin structural and molecular determinants are uncoupled during repair. The phospho-H2AX nano-domains arrange into higher-order clustered structures of discontinuously phosphorylated chromatin, flanked by CTCF. CTCF knockdown impairs spreading of the phosphorylation throughout the 3D-looped nano-domains. Co-staining of phospho-H2AX with phospho-Ku70 and TUNEL reveals that clusters rather than nano-foci represent single DSBs. Hence, each chromatin loop is a nano-focus, whose clusters correspond to previously known phospho-H2AX foci.

  7. System identification of smart structures using a wavelet neuro-fuzzy model

    International Nuclear Information System (INIS)

    Mitchell, Ryan; Kim, Yeesock; El-Korchi, Tahar

    2012-01-01

    This paper proposes a complex model of smart structures equipped with magnetorheological (MR) dampers. Nonlinear behavior of the structure–MR damper systems is represented by the use of a wavelet-based adaptive neuro-fuzzy inference system (WANFIS). The WANFIS is developed through the integration of wavelet transforms, artificial neural networks, and fuzzy logic theory. To evaluate the effectiveness of the WANFIS model, a three-story building employing an MR damper under a variety of natural hazards is investigated. An artificial earthquake is used for training the input–output mapping of the WANFIS model. The artificial earthquake is generated such that the characteristics of a variety of real recorded earthquakes are included. It is demonstrated that this new WANFIS approach is effective in modeling nonlinear behavior of the structure–MR damper system subjected to a variety of disturbances while resulting in shorter training times in comparison with an adaptive neuro-fuzzy inference system (ANFIS) model. Comparison with high fidelity data proves the viability of the proposed approach in a structural health monitoring setting, and it is validated using known earthquake signals such as El-Centro, Kobe, Northridge, and Hachinohe. (paper)

  8. Coherent structure dynamics and identification during the multistage transitions of polymeric turbulent channel flow

    Science.gov (United States)

    Zhu, Lu; Xi, Li

    2018-04-01

    Drag reduction induced by polymer additives in wall-bounded turbulence has been studied for decades. A small dosage of polymer additives can drastically reduce the energy dissipation in turbulent flows and alter the flow structures at the same time. As the polymer-induced fluid elasticity increases, drag reduction goes through several stages of transition with drastically different flow statistics. While much attention in the area of polymer-turbulence interactions has been focused on the onset and the asymptotic stage of maximum drag reduction, the transition between the two intermediate stages – low-extent drag reduction (LDR) and high-extent drag reduction (HDR) – likely reflects a qualitative change in the underlying vortex dynamics according to our recent study [1]. In particular, we proposed that polymers start to suppress the lift-up and bursting of vortices at HDR, leading to the localization of turbulent structures. To test our hypothesis, a statistically robust conditional sampling algorithm, based on Jenong and Hussain [2]’s work, was adopted in this study. The comparison of conditional eddies between the Newtonian and the highly elastic turbulence shows that (i) the lifting “strength” of vortices is suppressed by polymers as reflected by the decreasing lifting angle of the conditional eddy and (ii) the curvature of vortices is also eliminated as the orientation of the head of the conditional eddy changes. In summary, the results of conditional sampling support our hypothesis of polymer-turbulence interactions during the LDR-HDR transition.

  9. Identification and characterisation of a novel acylpeptide hydrolase from Sulfolobus solfataricus: structural and functional insights.

    Directory of Open Access Journals (Sweden)

    Marta Gogliettino

    Full Text Available A novel acylpeptide hydrolase, named APEH-3(Ss, was isolated from the hypertermophilic archaeon Sulfolobus solfataricus. APEH is a member of the prolyl oligopeptidase family which catalyzes the removal of acetylated amino acid residues from the N terminus of oligopeptides. The purified enzyme shows a homotrimeric structure, unique among the associate partners of the APEH cluster and, in contrast to the archaeal APEHs which show both exo/endo peptidase activities, it appears to be a "true" aminopeptidase as exemplified by its mammalian counterparts, with which it shares a similar substrate specificity. Furthermore, a comparative study on the regulation of apeh gene expression, revealed a significant but divergent alteration in the expression pattern of apeh-3(Ss and apeh(Ss (the gene encoding the previously identified APEH(Ss from S. solfataricus, which is induced in response to various stressful growth conditions. Hence, both APEH enzymes can be defined as stress-regulated proteins which play a complementary role in enabling the survival of S. solfataricus cells under different conditions. These results provide new structural and functional insights into S. solfataricus APEH, offering a possible explanation for the multiplicity of this enzyme in Archaea.

  10. Identification of Transthyretin Fibril Formation Inhibitors Using Structure-Based Virtual Screening.

    Science.gov (United States)

    Ortore, Gabriella; Martinelli, Adriano

    2017-08-22

    Transthyretin (TTR) is the primary carrier for thyroxine (T 4 ) in cerebrospinal fluid and a secondary carrier in blood. TTR is a stable homotetramer, but certain factors, genetic or environmental, could promote its degradation to form amyloid fibrils. A docking study using crystal structures of wild-type TTR was planned; our aim was to design new ligands that are able to inhibit TTR fibril formation. The computational protocol was thought to overcome the multiple binding modes of the ligands induced by the peculiarity of the TTR binding site and by the pseudosymmetry of the site pockets, which generally weaken such structure-based studies. Two docking steps, one that is very fast and a subsequent step that is more accurate, were used to screen the Aldrich Market Select database. Five compounds were selected, and their activity toward inhibiting TTR fibril formation was assessed. Three compounds were observed to be actives, two of which have the same potency as the positive control, and the other was found to be a promising lead compound. These results validate a computational protocol that is able to archive information on the key interactions between database compounds and TTR, which is valuable for supporting further studies. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Genetic analysis and morphological identification of pilus-like structures in members of the genus Bifidobacterium

    LENUS (Irish Health Repository)

    2011-08-30

    Abstract Background Cell surface pili in Gram positive bacteria have been reported to orchestrate the colonization of host tissues, evasion of immunity and the development of biofilms. So far, little if any information is available on the presence of pilus-like structures in human gut commensals like bifidobacteria. Results and discussion In this report, Atomic Force Microscopy (AFM) of various bifidobacterial strains belonging to Bifidobacterium bifidum, Bifidobacterium longum subsp. longum, Bifidobacterium dentium, Bifidobacterium adolescentis and Bifidobacterium animalis subsp. lactis revealed the existence of appendages resembling pilus-like structures. Interestingly, these microorganisms harbour two to six predicted pilus gene clusters in their genome, with each organized in an operon encompassing the major pilin subunit-encoding gene (designated fimA or fimP) together with one or two minor pilin subunit-encoding genes (designated as fimB and\\/or fimQ), and a gene encoding a sortase enzyme (strA). Quantitative Real Time (qRT)-PCR analysis and RT-PCR experiments revealed a polycistronic mRNA, encompassing the fimA\\/P and fimB\\/Q genes, which are differentially expressed upon cultivation of bifidobacteria on various glycans.

  12. Identification of the gate regions in the primary structure of the secretin pIV.

    Science.gov (United States)

    Spagnuolo, Julian; Opalka, Natacha; Wen, Wesley X; Gagic, Dragana; Chabaud, Elodie; Bellini, Pierdomenico; Bennett, Matthew D; Norris, Gillian E; Darst, Seth A; Russel, Marjorie; Rakonjac, Jasna

    2010-04-01

    Secretins are a family of large bacterial outer membrane channels that serve as exit ports for folded proteins, filamentous phage and surface structures. Despite the large size of their substrates, secretins do not compromise the barrier function of the outer membrane, implying a gating mechanism. The region in the primary structure that forms the putative gate has not previously been determined for any secretin. To identify residues involved in gating the pIV secretin of filamentous bacteriophage f1, we used random mutagenesis of the gene followed by positive selection for mutants with compromised barrier function ('leaky' mutants). We identified mutations in 34 residues, 30 of which were clustered into two regions located in the centre of the conserved C-terminal secretin family domain: GATE1 (that spanned 39 residues) and GATE2 (that spanned 14 residues). An internal deletion constructed in the GATE2 region resulted in a severely leaky phenotype. Three of the four remaining mutations are located in the region that encodes the N-terminal, periplasmic portion of pIV and could be involved in triggering gate opening. Two missense mutations in the 24-residue region that separates GATE1 and GATE2 were also constructed. These mutant proteins were unstable, defective in multimerization and non-functional.

  13. Identification and Assessment of Material Models for Age-Related Degradation of Structures and Passive Components in Nuclear Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Nie,J.; Braverman, J.; Hofmayer, C.; Kim, M. K.; Choi, I-K.

    2009-04-27

    When performing seismic safety assessments of nuclear power plants (NPPs), the potential effects of age-related degradation on structures, systems, and components (SSCs) should be considered. To address the issue of aging degradation, the Korea Atomic Energy Research Institute (KAERI) has embarked on a five-year research project to develop a realistic seismic risk evaluation system which will include the consideration of aging of structures and components in NPPs. Three specific areas that are included in the KAERI research project, related to seismic probabilistic risk assessment (PRA), are probabilistic seismic hazard analysis, seismic fragility analysis including the effects of aging, and a plant seismic risk analysis. To support the development of seismic capability evaluation technology for degraded structures and components, KAERI entered into a collaboration agreement with Brookhaven National Laboratory (BNL) in 2007. The collaborative research effort is intended to continue over a five year period with the goal of developing seismic fragility analysis methods that consider the potential effects of age-related degradation of SSCs, and using these results as input to seismic PRAs. In the Year 1 scope of work BNL collected and reviewed degradation occurrences in US NPPs and identified important aging characteristics needed for the seismic capability evaluations that will be performed in the subsequent evaluations in the years that follow. This information is presented in the Annual Report for the Year 1 Task, identified as BNL Report-81741-2008 and also designated as KAERI/RR-2931/2008. The report presents results of the statistical and trending analysis of this data and compares the results to prior aging studies. In addition, the report provides a description of U.S. current regulatory requirements, regulatory guidance documents, generic communications, industry standards and guidance, and past research related to aging degradation of SSCs. This report

  14. Human metabolites of brevetoxin PbTx-2: Identification and confirmation of structure

    Science.gov (United States)

    Guo, Fujiang; An, Tianying; Rein, Kathleen S.

    2010-01-01

    Four metabolites were identified upon incubation of brevetoxin (PbTx-2) with human liver microsomes. Chemical transformation of PbTx-2 confirmed the structures of three known metabolites BTX-B5, PbTx-9 and 41, 43-dihydro-BTX-B5 and a previously unknown metabolite, 41, 43-dihydro-PbTx-2. These metabolites were also observed upon incubation of PbTx-2 with nine human recombinant cytochrome P450s (1A1, 1A2, 2C8, 2C9, 2C19, 2D6, 2E1, 3A4 and 3A5). Cytochrome P450 3A4 produced oxidized metabolites while other CYPs generated the reduced products. PMID:20600229

  15. Structure Identification of Uncertain Complex Networks Based on Anticipatory Projective Synchronization.

    Directory of Open Access Journals (Sweden)

    Liu Heng

    Full Text Available This paper investigates a method to identify uncertain system parameters and unknown topological structure in general complex networks with or without time delay. A complex network, which has uncertain topology and unknown parameters, is designed as a drive network, and a known response complex network with an input controller is designed to identify the drive network. Under the proposed input controller, the drive network and the response network can achieve anticipatory projective synchronization when the system is steady. Lyapunov theorem and Barbǎlat's lemma guarantee the stability of synchronization manifold between two networks. When the synchronization is achieved, the system parameters and topology in response network can be changed to equal with the parameters and topology in drive network. A numerical example is given to show the effectiveness of the proposed method.

  16. Identification of support structure damping of a full scale offshore wind turbine in normal operation

    DEFF Research Database (Denmark)

    Koukoura, Christina; Natarajan, Anand; Vesth, Allan

    2015-01-01

    damping from the decaying time series. The Enhanced Frequency Domain Decomposition (EFDD) method was applied to the wind turbine response under ambient excitation, for estimation of the damping in normal operation. The aero-servo-hydro-elastic tool HAWC2 is validated with offshore foundation load...... maxima of an impulse response caused by a boat impact. The result is used in the verification of the non aerodynamic damping in normal operation for low wind speeds. The auto-correlation function technique for damping estimation of a structure under ambient excitation was validated against the identified...... measurements. The model was tuned to the damping values obtained from the boat impact to match the measured loads. Wind turbulence intensity and wave characteristics used in the simulations are based on site measurements. A flexible soil model is included in the analysis. The importance of the correctly...

  17. Sensitive Phonon-Based Probe for Structure Identification of 1T' MoTe2.

    Science.gov (United States)

    Zhou, Lin; Huang, Shengxi; Tatsumi, Yuki; Wu, Lijun; Guo, Huaihong; Bie, Ya-Qing; Ueno, Keiji; Yang, Teng; Zhu, Yimei; Kong, Jing; Saito, Riichiro; Dresselhaus, Mildred

    2017-06-28

    In this work, by combining transmission electron microscopy and polarized Raman spectroscopy for the 1T' MoTe 2 flakes with different thicknesses, we found that the polarization dependence of Raman intensity is given as a function of excitation laser wavelength, phonon symmetry, and phonon frequency, but has weak dependence on the flake thickness from few-layer to multilayer. In addition, the frequency of Raman peaks and the relative Raman intensity are sensitive to flake thickness, which manifests Raman spectroscopy as an effective probe for thickness of 1T' MoTe 2 . Our work demonstrates that polarized Raman spectroscopy is a powerful and nondestructive method to quickly identify the crystal structure and thickness of 1T' MoTe 2 simultaneously, which opens up opportunities for the in situ probe of anisotropic properties and broad applications of this novel material.

  18. Within-person changes in the structure of emotion: the role of cultural identification and language.

    Science.gov (United States)

    Perunovic, Wei Qi Elaine; Heller, Daniel; Rafaeli, Eshkol

    2007-07-01

    This study explored the within-person dynamic organization of emotion in East-Asian Canadian bicultural individuals as they function in two cultural worlds. Using a diary design, we examined under what conditions their emotional structure resembles that of Westerners or that of East Asians. As predicted, when these bicultural individuals identified with a Western culture or had recently spoken a non-Asian language, their positive and negative affect were inversely associated. When they identified with an Asian culture or interacted in an Asian language, this inverse association disappeared. This study shows that as bicultural individuals identify and communicate with members of one or the other cultural group, they may adopt a culturally congruent phenomenology, including a distinct affective pattern.

  19. Atomic structure calculations and identification of EUV and SXR spectral lines in Sr XXX

    International Nuclear Information System (INIS)

    Goyal, Arun; Khatri, Indu; Aggarwal, Sunny; Singh, A.K.; Mohan, Man

    2015-01-01

    We report an extensive theoretical study of atomic data for Sr XXX in a wide range with L-shell electron excitations to the M-shell. We have calculated energy levels, wave-function compositions and lifetimes for lowest 113 fine structure levels and wavelengths of an extreme Ultraviolet (EUV) and soft X-ray (SXR) transitions. We have employed multi-configuration Dirac Fock method (MCDF) approach within the framework of Dirac–Coulomb Hamiltonian including quantum electrodynamics (QED) and Breit corrections. We have also presented the radiative data for electric and magnetic dipole (E1, M1) and quadrupole (E2, M2) transitions from the ground state. We have made comparisons with available energy levels compiled by NIST and achieve good agreement. But due to inadequate data in the literature, analogous relativistic distorted wave calculations have also been performed using flexible atomic code (FAC) to assess the reliability and accuracy of our results. Additionally, we have provided new atomic data for Sr XXX which is not published elsewhere in the literature and we believe that our results may be beneficial in fusion plasma research and astrophysical investigations and applications. - Highlights: • 113 Lowest levels for Sr XXX are calculated. • Extreme Ultraviolet (EUV) and soft-X ray (SXR) spectral lines are identified. • Wavelengths of EUV and SXR spectral lines are reported. • E1, E2, M1 and M2 transition rates, oscillator strengths and lines strengths for lowest 113 levels are presented. • Lifetimes for lowest 113 fine structure levels are provided

  20. Wall-based identification of coherent structures in wall-bounded turbulence

    Science.gov (United States)

    Sanmiguel Vila, C.; Flores, O.

    2018-04-01

    During the last decades, a number of reduced order models based on coherent structures have been proposed to describe wall-bounded turbulence. Many of these models emphasize the importance of coherent wall-normal velocity eddies (ν-eddies), which drive the generation of the very long streamwise velocity structures observed in the logarithmic and outer region. In order to use these models to improve our ability to control wall-bounded turbulence in realistic applications, these ν-eddies need to be identified from the wall in a non-intrusive way. In this paper, the possibility of using the pressure signal at the wall to identify these ν-eddies is explored, analyzing the cross-correlation between the wall-normal velocity component and the pressure fluctuations at the wall in a DNS of a turbulent channel flow at Reτ = 939. The results show that the cross-correlation has a region of negative correlation upstream, and a region of positive correlation backwards. In the spanwise direction the correlation decays monotonously, except very close to the wall where a change of sign of the correlation coefficient is observed. Moreover, filtering the pressure fluctuations at the wall in space results in an increase of the region where the cross-correlation is strong, both for the positively and the negatively correlated regions. The use of a time filter for the pressure fluctuations at the wall yields different results, displacing the regions of strong correlation without changing much their sizes. The results suggest that space-filtering the pressure at the wall is a feasible way to identify ν-eddies of different sizes, which could be used to trigger turbulent control strategies.

  1. Large scale identification and categorization of protein sequences using structured logistic regression.

    Directory of Open Access Journals (Sweden)

    Bjørn P Pedersen

    Full Text Available BACKGROUND: Structured Logistic Regression (SLR is a newly developed machine learning tool first proposed in the context of text categorization. Current availability of extensive protein sequence databases calls for an automated method to reliably classify sequences and SLR seems well-suited for this task. The classification of P-type ATPases, a large family of ATP-driven membrane pumps transporting essential cations, was selected as a test-case that would generate important biological information as well as provide a proof-of-concept for the application of SLR to a large scale bioinformatics problem. RESULTS: Using SLR, we have built classifiers to identify and automatically categorize P-type ATPases into one of 11 pre-defined classes. The SLR-classifiers are compared to a Hidden Markov Model approach and shown to be highly accurate and scalable. Representing the bulk of currently known sequences, we analysed 9.3 million sequences in the UniProtKB and attempted to classify a large number of P-type ATPases. To examine the distribution of pumps on organisms, we also applied SLR to 1,123 complete genomes from the Entrez genome database. Finally, we analysed the predicted membrane topology of the identified P-type ATPases. CONCLUSIONS: Using the SLR-based classification tool we are able to run a large scale study of P-type ATPases. This study provides proof-of-concept for the application of SLR to a bioinformatics problem and the analysis of P-type ATPases pinpoints new and interesting targets for further biochemical characterization and structural analysis.

  2. Familial occurrence of isolated non-compaction cardiomyopathy

    NARCIS (Netherlands)

    Lorsheyd, Anouk; Cramer, Maarten-Jan M.; Velthuis, Birgitta K.; Vonken, Evert-Jan P.; van der Smagt, Jasper; van Tintelen, Peter; Hauer, Richard N. W.

    2006-01-01

    Background and aims: Isolated left ventricular non-compaction cardiomyopathy (LVNC) may have an autosomal dominant or X-linked recessive inheritance. We focus on the familial occurrence of LVNC after misdiagnosing this disorder in symptomatic patients in two families. After identification of the

  3. Three-dimensional electron diffraction as a complementary technique to powder X-ray diffraction for phase identification and structure solution of powders.

    Science.gov (United States)

    Yun, Yifeng; Zou, Xiaodong; Hovmöller, Sven; Wan, Wei

    2015-03-01

    Phase identification and structure determination are important and widely used techniques in chemistry, physics and materials science. Recently, two methods for automated three-dimensional electron diffraction (ED) data collection, namely automated diffraction tomography (ADT) and rotation electron diffraction (RED), have been developed. Compared with X-ray diffraction (XRD) and two-dimensional zonal ED, three-dimensional ED methods have many advantages in identifying phases and determining unknown structures. Almost complete three-dimensional ED data can be collected using the ADT and RED methods. Since each ED pattern is usually measured off the zone axes by three-dimensional ED methods, dynamic effects are much reduced compared with zonal ED patterns. Data collection is easy and fast, and can start at any arbitrary orientation of the crystal, which facilitates automation. Three-dimensional ED is a powerful technique for structure identification and structure solution from individual nano- or micron-sized particles, while powder X-ray diffraction (PXRD) provides information from all phases present in a sample. ED suffers from dynamic scattering, while PXRD data are kinematic. Three-dimensional ED methods and PXRD are complementary and their combinations are promising for studying multiphase samples and complicated crystal structures. Here, two three-dimensional ED methods, ADT and RED, are described. Examples are given of combinations of three-dimensional ED methods and PXRD for phase identification and structure determination over a large number of different materials, from Ni-Se-O-Cl crystals, zeolites, germanates, metal-organic frameworks and organic compounds to intermetallics with modulated structures. It is shown that three-dimensional ED is now as feasible as X-ray diffraction for phase identification and structure solution, but still needs further development in order to be as accurate as X-ray diffraction. It is expected that three-dimensional ED methods

  4. Three-dimensional electron diffraction as a complementary technique to powder X-ray diffraction for phase identification and structure solution of powders

    Directory of Open Access Journals (Sweden)

    Yifeng Yun

    2015-03-01

    Full Text Available Phase identification and structure determination are important and widely used techniques in chemistry, physics and materials science. Recently, two methods for automated three-dimensional electron diffraction (ED data collection, namely automated diffraction tomography (ADT and rotation electron diffraction (RED, have been developed. Compared with X-ray diffraction (XRD and two-dimensional zonal ED, three-dimensional ED methods have many advantages in identifying phases and determining unknown structures. Almost complete three-dimensional ED data can be collected using the ADT and RED methods. Since each ED pattern is usually measured off the zone axes by three-dimensional ED methods, dynamic effects are much reduced compared with zonal ED patterns. Data collection is easy and fast, and can start at any arbitrary orientation of the crystal, which facilitates automation. Three-dimensional ED is a powerful technique for structure identification and structure solution from individual nano- or micron-sized particles, while powder X-ray diffraction (PXRD provides information from all phases present in a sample. ED suffers from dynamic scattering, while PXRD data are kinematic. Three-dimensional ED methods and PXRD are complementary and their combinations are promising for studying multiphase samples and complicated crystal structures. Here, two three-dimensional ED methods, ADT and RED, are described. Examples are given of combinations of three-dimensional ED methods and PXRD for phase identification and structure determination over a large number of different materials, from Ni–Se–O–Cl crystals, zeolites, germanates, metal–organic frameworks and organic compounds to intermetallics with modulated structures. It is shown that three-dimensional ED is now as feasible as X-ray diffraction for phase identification and structure solution, but still needs further development in order to be as accurate as X-ray diffraction. It is expected that three

  5. Structural elucidation and identification of a new derivative of phenethylamine using quadrupole time-of-flight mass spectrometry.

    Science.gov (United States)

    Sekuła, Karolina; Zuba, Dariusz

    2013-09-30

    In recent years, the phenomenon of uncontrolled distribution of new psychoactive substances that were marketed without prior toxicological studies has been observed. Because many designer drugs are related in chemical structure, the potential for misidentifying them is an important problem. It is therefore essential to develop an analytical procedure for unequivocal elucidation of the structures of these compounds. The issue has been discussed in the context of 25I-NBMD [2-(4-iodo-2,5-dimethoxyphenyl)-N-[(2,3-methylenedioxyphenyl)methyl]ethanamine], a psychoactive substance first discovered on the drug market in 2012. The substance was extracted from blotter papers with methanol. Separation was achieved via liquid chromatography. Analysis was conducted by electrospray ionization quadrupole time-of-flight mass spectrometry (ESI-QTOFMS). Identification of the psychoactive component was supported by electron impact gas chromatography/mass spectrometry (GC/EI-MS). The high accuracy of the LC/ESI-QTOFMS method allowed the molecular mass of the investigated substance (M(exp) = 441.0438 Da; mass error, ∆m = 0.2 ppm) and the formulae of ions formed during fragmentation to be determined. The main ions were recorded at m/z = 135.0440, 290.9876 and 305.9981. Structures of the obtained ions were elucidated in the tandem mass spectrometry (MS/MS) experiments by comparing them to mass spectra of previously detected derivatives of phenethylamine. The performed study indicated the potential for using LC/QTOFMS method to identify new designer drugs. This technique can be used supplementary to standard GC/MS. Prior knowledge of the fragmentation mechanisms of phenethylamines allowed to predict the mass spectra of the novel substance--25I-NBMD. Copyright © 2013 John Wiley & Sons, Ltd.

  6. Diurnal and seasonal occurrence of polar patches

    Directory of Open Access Journals (Sweden)

    A. S. Rodger

    1996-05-01

    Full Text Available Analysis of the diurnal and seasonal variation of polar patches, as identified in two years of HF-radar data from Halley, Antarctica during a period near sunspot maximum, shows that there is a broad maximum in occurrence centred about magnetic noon, not local noon. There are minima in occurrence near midsummer and midwinter, with maxima in occurrence between equinox and winter. There are no significant correlations between the occurrence of polar patches and the corresponding hourly averages of the solar wind and IMF parameters, except that patches usually occur when the interplanetary magnetic field has a southward component. The results can be understood in terms of UT and seasonal differences in the plasma concentration being convected from the dayside ionosphere into the polar cap. In summer and winter the electron concentrations in the polar cap are high and low, respectively, but relatively unstructured. About equinox, a tongue of enhanced ionisation is convected into the polar cap; this tongue is then structured by the effects of the interplanetary magnetic field, but these Halley data cannot be used to separate the various competing mechanisms for patch formation. The observed diurnal and seasonal variation in the occurrence of polar patches are largely consistent with predictions of Sojka et al. (1994 when their results are translated into the southern hemisphere. However, the ionospheric effects of flux transfer events are still considered essential in their formation, a feature not yet included in the Sojka et al. model.

  7. Identification of structural protein-protein interactions of herpes simplex virus type 1.

    Science.gov (United States)

    Lee, Jin H; Vittone, Valerio; Diefenbach, Eve; Cunningham, Anthony L; Diefenbach, Russell J

    2008-09-01

    In this study we have defined protein-protein interactions between the structural proteins of herpes simplex virus type 1 (HSV-1) using a LexA yeast two-hybrid system. The majority of the capsid, tegument and envelope proteins of HSV-1 were screened in a matrix approach. A total of 40 binary interactions were detected including 9 out of 10 previously identified tegument-tegument interactions (Vittone, V., Diefenbach, E., Triffett, D., Douglas, M.W., Cunningham, A.L., and Diefenbach, R.J., 2005. Determination of interactions between tegument proteins of herpes simplex virus type 1. J. Virol. 79, 9566-9571). A total of 12 interactions involving the capsid protein pUL35 (VP26) and 11 interactions involving the tegument protein pUL46 (VP11/12) were identified. The most significant novel interactions detected in this study, which are likely to play a role in viral assembly, include pUL35-pUL37 (capsid-tegument), pUL46-pUL37 (tegument-tegument) and pUL49 (VP22)-pUS9 (tegument-envelope). This information will provide further insights into the pathways of HSV-1 assembly and the identified interactions are potential targets for new antiviral drugs.

  8. Identification of linear B-cell epitopes on goose parvovirus non-structural protein.

    Science.gov (United States)

    Yu, Tian-Fei; Ma, Bo; Wang, Jun-Wei

    2016-10-15

    Goose parvovirus (GPV) infection can cause a highly contagious and lethal disease in goslings and muscovy ducklings which is widespread in all major goose (Anser anser) and Muscovy duck (Cairina moschata) farming countries, leading to a huge economic loss. Humoral immune responses play a major role in GPV immune protection during GPV infection. However, it is still unknown for the localization and immunological characteristics of B-cell epitopes on GPV non-structural protein (NSP). Therefore, in this study, the epitopes on the NSP of GPV were identified by means of overlapping peptides expressed in Escherichia coli in combination with Western blot. The results showed that the antigenic epitopes on the GPV NSP were predominantly localized in the C-terminal (aa 485-627), and especially, the fragment NS (498-532) was strongly positive. These results may facilitate future investigations on the function of NSP of GPV and the development of immunoassays for the diagnosis of GPV infection. Copyright © 2016. Published by Elsevier B.V.

  9. Identification of antigenic domains in the non-structural protein of Muscovy duck parvovirus.

    Science.gov (United States)

    Yu, Tian-Fei; Li, Ming; Yan, Bing; Shao, Shu-Li; Fan, Xing-Dong; Wang, Jia; Wang, Dan-Na

    2016-08-01

    Muscovy duck parvovirus (MDPV) infection is widespread in many Muscovy-duck-farming countries, leading to a huge economic loss. By means of overlapping peptides expressed in Escherichia coli in combination with Western blot, antigenic domains on the non-structural protein (NSP) of MDPV were identified for the first time. On the Western blot, the fragments NS(481-510), NS (501-530), NS (521-550), NS (541-570), NS (561-590), NS (581-610) and NS (601-627) were positive (the numbers in parentheses indicate the location of amino acids), and other fragments were negative. These seven fragments were also reactive in an indirect enzyme-linked immunosorbent assay (i-ELISA). We therefore conclude that a linear antigenic domain of the NSP is located at its C-terminal end (amino acid residues 481-627). These results may facilitate future investigations into the function of NSP of MDPV and the development of immunoassays for the diagnosis of MDPV infection.

  10. Atomic structure calculations and identification of EUV and SXR spectral lines in Sr XXX

    Science.gov (United States)

    Goyal, Arun; Khatri, Indu; Aggarwal, Sunny; Singh, A. K.; Mohan, Man

    2015-08-01

    We report an extensive theoretical study of atomic data for Sr XXX in a wide range with L-shell electron excitations to the M-shell. We have calculated energy levels, wave-function compositions and lifetimes for lowest 113 fine structure levels and wavelengths of an extreme Ultraviolet (EUV) and soft X-ray (SXR) transitions. We have employed multi-configuration Dirac Fock method (MCDF) approach within the framework of Dirac-Coulomb Hamiltonian including quantum electrodynamics (QED) and Breit corrections. We have also presented the radiative data for electric and magnetic dipole (E1, M1) and quadrupole (E2, M2) transitions from the ground state. We have made comparisons with available energy levels compiled by NIST and achieve good agreement. But due to inadequate data in the literature, analogous relativistic distorted wave calculations have also been performed using flexible atomic code (FAC) to assess the reliability and accuracy of our results. Additionally, we have provided new atomic data for Sr XXX which is not published elsewhere in the literature and we believe that our results may be beneficial in fusion plasma research and astrophysical investigations and applications.

  11. Structural identification of novel oligosaccharides produced by Lactobacillus bulgaricus and Lactobacillus plantarum.

    Science.gov (United States)

    Black, Brenna A; Lee, Vivian S Y; Zhao, Yuan Yuan; Hu, Ying; Curtis, Jonathan M; Gänzle, Michael G

    2012-05-16

    β-Galactosidases (β-Gal) of lactic acid bacteria produce oligosaccharides from lactose when suitable acceptor carbohydrates are present. This study aimed to elucidate the structure of oligosaccharides formed by galactosylation of N-acetylglucosamine (GlcNAc) and fucose. Crude cellular extract of Lactobacillus bulgaricus and LacLM of Lactobacillus plantarum were used as sources of β-Gal activity. Disaccharides obtained by galactosylation of GlcNAc were identified as Gal-β-(1→4)-GlcNAc or Gal-β-(1→6)-GlcNAc by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and comparison with external standards. Trisaccharides were identified as Gal-β-(1→6)-Gal-β-(1→[4 or 6])-GlcNAc by LC-MS, analysis of the MS/MS spectra of selected in-source fragment ions, and their relative retention times. LC-MS analysis revealed the presence of five galactosylated fucosides, but their linkage type could not be identified, partly due to the lack of reference compounds. β-Gal of lactic acid bacteria may serve as suitable tools for the chemoenzymatic synthesis of therapeutic oligosaccharides.

  12. Substantial population structure of Plasmodium vivax in Thailand facilitates identification of the sources of residual transmission.

    Directory of Open Access Journals (Sweden)

    Veerayuth Kittichai

    2017-10-01

    Full Text Available Plasmodium vivax transmission in Thailand has been substantially reduced over the past 10 years, yet it remains highly endemic along international borders. Understanding the genetic relationship of residual parasite populations can help track the origins of the parasites that are reintroduced into malaria-free regions within the country.A total of 127 P. vivax isolates were genotyped from two western provinces (Tak and Kanchanaburi and one eastern province (Ubon Ratchathani of Thailand using 10 microsatellite markers. Genetic diversity was high, but recent clonal expansion was detected in all three provinces. Substantial population structure and genetic differentiation of parasites among provinces suggest limited gene flow among these sites. There was no haplotype sharing among the three sites, and a reduced panel of four microsatellite markers was sufficient to assign the parasites to their provincial origins.Significant parasite genetic differentiation between provinces shows successful interruption of parasite spread within Thailand, but high diversity along international borders implies a substantial parasite population size in these regions. The provincial origin of P. vivax cases can be reliably determined by genotyping four microsatellite markers, which should be useful for monitoring parasite reintroduction after malaria elimination.

  13. Substantial population structure of Plasmodium vivax in Thailand facilitates identification of the sources of residual transmission.

    Science.gov (United States)

    Kittichai, Veerayuth; Koepfli, Cristian; Nguitragool, Wang; Sattabongkot, Jetsumon; Cui, Liwang

    2017-10-01

    Plasmodium vivax transmission in Thailand has been substantially reduced over the past 10 years, yet it remains highly endemic along international borders. Understanding the genetic relationship of residual parasite populations can help track the origins of the parasites that are reintroduced into malaria-free regions within the country. A total of 127 P. vivax isolates were genotyped from two western provinces (Tak and Kanchanaburi) and one eastern province (Ubon Ratchathani) of Thailand using 10 microsatellite markers. Genetic diversity was high, but recent clonal expansion was detected in all three provinces. Substantial population structure and genetic differentiation of parasites among provinces suggest limited gene flow among these sites. There was no haplotype sharing among the three sites, and a reduced panel of four microsatellite markers was sufficient to assign the parasites to their provincial origins. Significant parasite genetic differentiation between provinces shows successful interruption of parasite spread within Thailand, but high diversity along international borders implies a substantial parasite population size in these regions. The provincial origin of P. vivax cases can be reliably determined by genotyping four microsatellite markers, which should be useful for monitoring parasite reintroduction after malaria elimination.

  14. Crystal structure and putative substrate identification for the Entamoeba histolytica low molecular weight tyrosine phosphatase.

    Science.gov (United States)

    Linford, Alicia S; Jiang, Nona M; Edwards, Thomas E; Sherman, Nicholas E; Van Voorhis, Wesley C; Stewart, Lance J; Myler, Peter J; Staker, Bart L; Petri, William A

    2014-01-01

    Entamoeba histolytica is a eukaryotic intestinal parasite of humans, and is endemic in developing countries. We have characterized the E. histolytica putative low molecular weight protein tyrosine phosphatase (LMW-PTP). The structure for this amebic tyrosine phosphatase was solved, showing the ligand-induced conformational changes necessary for binding of substrate. In amebae, it was expressed at low but detectable levels as detected by immunoprecipitation followed by immunoblotting. A mutant LMW-PTP protein in which the catalytic cysteine in the active site was replaced with a serine lacked phosphatase activity, and was used to identify a number of trapped putative substrate proteins via mass spectrometry analysis. Seven of these putative substrate protein genes were cloned with an epitope tag and overexpressed in amebae. Five of these seven putative substrate proteins were demonstrated to interact specifically with the mutant LMW-PTP. This is the first biochemical study of a small tyrosine phosphatase in Entamoeba, and sets the stage for understanding its role in amebic biology and pathogenesis. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Ligand and Structure-Based Approaches for the Identification of Peptide Deformylase Inhibitors as Antibacterial Drugs.

    Science.gov (United States)

    Gao, Jian; Liang, Li; Zhu, Yasheng; Qiu, Shengzhi; Wang, Tao; Zhang, Ling

    2016-07-15

    Peptide deformylase (PDF) is a metalloprotease catalyzing the removal of a formyl group from newly synthesized proteins, which makes it an important antibacterial drug target. Given the importance of PDF inhibitors like actinonin in antibacterial drug discovery, several reported potent PDF inhibitors were used to develop pharmacophore models using the Galahad module of Sybyl 7.1 software. Generated pharmacophore models were composed of two donor atom centers, four acceptor atom centers and two hydrophobic groups. Model-1 was screened against the Zinc database and several compounds were retrieved as hits. Compounds with Qfit values of more than 60 were employed to perform a molecular docking study with the receptor Escherichia coli PDF, then compounds with docking score values of more than 6 were used to predict the in silico pharmacokinetic and toxicity risk via OSIRIS property explorer. Two known PDF inhibitors were also used to perform a molecular docking study with E. coli PDF as reference molecules. The results of the molecular docking study were validated by reproducing the crystal structure of actinonin. Molecular docking and in silico pharmacokinetic and toxicity prediction studies suggested that ZINC08740166 has a relatively high docking score of 7.44 and a drug score of 0.78.

  16. Virtual Lead Identification of Farnesyltransferase Inhibitors Based on Ligand and Structure-Based Pharmacophore Techniques

    Directory of Open Access Journals (Sweden)

    Nizar M. Mhaidat

    2013-05-01

    Full Text Available Farnesyltransferase enzyme (FTase is considered an essential enzyme in the Ras signaling pathway associated with cancer. Thus, designing inhibitors for this enzyme might lead to the discovery of compounds with effective anticancer activity. In an attempt to obtain effective FTase inhibitors, pharmacophore hypotheses were generated using structure-based and ligand-based approaches built in Discovery Studio v3.1. Knowing the presence of the zinc feature is essential for inhibitor’s binding to the active site of FTase enzyme; further customization was applied to include this feature in the generated pharmacophore hypotheses. These pharmacophore hypotheses were thoroughly validated using various procedures such as ROC analysis and ligand pharmacophore mapping. The validated pharmacophore hypotheses were used to screen 3D databases to identify possible hits. Those which were both high ranked and showed sufficient ability to bind the zinc feature in active site, were further refined by applying drug-like criteria such as Lipiniski’s “rule of five” and ADMET filters. Finally, the two candidate compounds (ZINC39323901 and ZINC01034774 were allowed to dock using CDOCKER and GOLD in the active site of FTase enzyme to optimize hit selection.

  17. Identification of alterations associated with age in the clustering structure of functional brain networks.

    Science.gov (United States)

    Guzman, Grover E C; Sato, Joao R; Vidal, Maciel C; Fujita, Andre

    2018-01-01

    Initial studies using resting-state functional magnetic resonance imaging on the trajectories of the brain network from childhood to adulthood found evidence of functional integration and segregation over time. The comprehension of how healthy individuals' functional integration and segregation occur is crucial to enhance our understanding of possible deviations that may lead to brain disorders. Recent approaches have focused on the framework wherein the functional brain network is organized into spatially distributed modules that have been associated with specific cognitive functions. Here, we tested the hypothesis that the clustering structure of brain networks evolves during development. To address this hypothesis, we defined a measure of how well a brain region is clustered (network fitness index), and developed a method to evaluate its association with age. Then, we applied this method to a functional magnetic resonance imaging data set composed of 397 males under 31 years of age collected as part of the Autism Brain Imaging Data Exchange Consortium. As results, we identified two brain regions for which the clustering change over time, namely, the left middle temporal gyrus and the left putamen. Since the network fitness index is associated with both integration and segregation, our finding suggests that the identified brain region plays a role in the development of brain systems.

  18. Identification of Mycobacterium tuberculosis BioA inhibitors by using structure-based virtual screening

    Science.gov (United States)

    Singh, Swati; Khare, Garima; Bahal, Ritika Kar; Ghosh, Prahlad C; Tyagi, Anil K

    2018-01-01

    Background 7,8-Diaminopelargonic acid synthase (BioA), an enzyme of biotin biosynthesis pathway, is a well-known promising target for anti-tubercular drug development. Methods In this study, structure-based virtual screening was employed against the active site of BioA to identify new chemical entities for BioA inhibition and top ranking compounds were evaluated for their ability to inhibit BioA enzymatic activity. Results Seven compounds inhibited BioA enzymatic activity by greater than 60% at 100 μg/mL with most potent compounds being A36, A35 and A65, displaying IC50 values of 10.48 μg/mL (28.94 μM), 33.36 μg/mL (88.16 μM) and 39.17 μg/mL (114.42 μM), respectively. Compounds A65 and A35 inhibited Mycobacterium tuberculosis (M. tuberculosis) growth with MIC90 of 20 μg/mL and 80 μg/mL, respectively, whereas compound A36 exhibited relatively weak inhibition of M. tuberculosis growth (83% inhibition at 200 μg/mL). Compound A65 emerged as the most potent compound identified in our study that inhibited BioA enzymatic activity and growth of the pathogen and possessed drug-like properties. Conclusion Our study has identified a few hit molecules against M. tuberculosis BioA that can act as potential candidates for further development of potent anti-tubercular therapeutic agents. PMID:29750019

  19. Identification of Mycobacterium tuberculosis BioA inhibitors by using structure-based virtual screening

    Directory of Open Access Journals (Sweden)

    Singh S

    2018-05-01

    Full Text Available Swati Singh,1 Garima Khare,1 Ritika Kar Bahal,1 Prahlad C Ghosh,1 Anil K Tyagi1,2 1Department of Biochemistry, University of Delhi South Campus, New Delhi, India; 2Guru Gobind Singh Indraprastha University, New Delhi, India Background: 7,8-Diaminopelargonic acid synthase (BioA, an enzyme of biotin biosynthesis pathway, is a well-known promising target for anti-tubercular drug development. Methods: In this study, structure-based virtual screening was employed against the active site of BioA to identify new chemical entities for BioA inhibition and top ranking compounds were evaluated for their ability to inhibit BioA enzymatic activity. Results: Seven compounds inhibited BioA enzymatic activity by greater than 60% at 100 µg/mL with most potent compounds being A36, A35 and A65, displaying IC50 values of 10.48 µg/mL (28.94 µM, 33.36 µg/mL (88.16 µM and 39.17 µg/mL (114.42 µM, respectively. Compounds A65 and A35 inhibited Mycobacterium tuberculosis (M. tuberculosis growth with MIC90 of 20 µg/mL and 80 µg/mL, respectively, whereas compound A36 exhibited relatively weak inhibition of M. tuberculosis growth (83% inhibition at 200 µg/mL. Compound A65 emerged as the most potent compound identified in our study that inhibited BioA enzymatic activity and growth of the pathogen and possessed drug-like properties. Conclusion: Our study has identified a few hit molecules against M. tuberculosis BioA that can act as potential candidates for further development of potent anti-tubercular therapeutic agents. Keywords: Mycobacterium tuberculosis, BioA, virtual screening, drug discovery

  20. Identification of dominant flow structures in rapidly rotating convection of liquid metals using Dynamic Mode Decomposition

    Science.gov (United States)

    Horn, S.; Schmid, P. J.; Aurnou, J. M.

    2016-12-01

    The Earth's metal core acts as a dynamo whose efficiency in generating and maintaining the magnetic field is essentially determined by the rotation rate and the convective motions occurring in its outer liquid part. For the description of the primary physics in the outer core the idealized system of rotating Rayleigh-Bénard convection is often invoked, with the majority of studies considering only working fluids with Prandtl numbers of Pr ≳ 1. However, liquid metals are characterized by distinctly smaller Prandtl numbers which in turn result in an inherently different type of convection. Here, we will present results from direct numerical simulations of rapidly rotating convection in a fluid with Pr ≈ 0.025 in cylindrical containers and Ekman numbers as low as 5 × 10-6. In this system, the Coriolis force is the source of two types of inertial modes, the so-called wall modes, that also exist at moderate Prandtl numbers, and cylinder-filling oscillatory modes, that are a unique feature of small Prandtl number convection. The obtained flow fields were analyzed using the Dynamic Mode Decomposition (DMD). This technique allows to extract and identify the structures that govern the dynamics of the system as well as their corresponding frequencies. We have investigated both the regime where the flow is purely oscillatory and the regime where wall modes and oscillatory modes co-exist. In the purely oscillatory regime, high and low frequency oscillatory modes characterize the flow. When both types of modes are present, the DMD reveals that the wall-attached modes dominate the flow dynamics. They precess with a relatively low frequency in retrograde direction. Nonetheless, also in this case, high frequency oscillations have a significant contribution.

  1. Comparing Structural Identification Methodologies for Fatigue Life Prediction of a Highway Bridge

    Directory of Open Access Journals (Sweden)

    Sai G. S. Pai

    2018-01-01

    Full Text Available Accurate measurement-data interpretation leads to increased understanding of structural behavior and enhanced asset-management decision making. In this paper, four data-interpretation methodologies, residual minimization, traditional Bayesian model updating, modified Bayesian model updating (with an L∞-norm-based Gaussian likelihood function, and error-domain model falsification (EDMF, a method that rejects models that have unlikely differences between predictions and measurements, are compared. In the modified Bayesian model updating methodology, a correction is used in the likelihood function to account for the effect of a finite number of measurements on posterior probability–density functions. The application of these data-interpretation methodologies for condition assessment and fatigue life prediction is illustrated on a highway steel–concrete composite bridge having four spans with a total length of 219 m. A detailed 3D finite-element plate and beam model of the bridge and weigh-in-motion data are used to obtain the time–stress response at a fatigue critical location along the bridge span. The time–stress response, presented as a histogram, is compared to measured strain responses either to update prior knowledge of model parameters using residual minimization and Bayesian methodologies or to obtain candidate model instances using the EDMF methodology. It is concluded that the EDMF and modified Bayesian model updating methodologies provide robust prediction of fatigue life compared with residual minimization and traditional Bayesian model updating in the presence of correlated non-Gaussian uncertainty. EDMF has additional advantages due to ease of understanding and applicability for practicing engineers, thus enabling incremental asset-management decision making over long service lives. Finally, parallel implementations of EDMF using grid sampling have lower computations times than implementations using adaptive sampling.

  2. Identification and Structure-Function Analysis of Subfamily Selective G Protein-Coupled Receptor Kinase Inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Homan, Kristoff T.; Larimore, Kelly M.; Elkins, Jonathan M.; Szklarz, Marta; Knapp, Stefan; Tesmer, John J.G. [Michigan; (Oxford)

    2015-02-13

    Selective inhibitors of individual subfamilies of G protein-coupled receptor kinases (GRKs) would serve as useful chemical probes as well as leads for therapeutic applications ranging from heart failure to Parkinson’s disease. To identify such inhibitors, differential scanning fluorimetry was used to screen a collection of known protein kinase inhibitors that could increase the melting points of the two most ubiquitously expressed GRKs: GRK2 and GRK5. Enzymatic assays on 14 of the most stabilizing hits revealed that three exhibit nanomolar potency of inhibition for individual GRKs, some of which exhibiting orders of magnitude selectivity. Most of the identified compounds can be clustered into two chemical classes: indazole/dihydropyrimidine-containing compounds that are selective for GRK2 and pyrrolopyrimidine-containing compounds that potently inhibit GRK1 and GRK5 but with more modest selectivity. The two most potent inhibitors representing each class, GSK180736A and GSK2163632A, were cocrystallized with GRK2 and GRK1, and their atomic structures were determined to 2.6 and 1.85 Å spacings, respectively. GSK180736A, developed as a Rho-associated, coiled-coil-containing protein kinase inhibitor, binds to GRK2 in a manner analogous to that of paroxetine, whereas GSK2163632A, developed as an insulin-like growth factor 1 receptor inhibitor, occupies a novel region of the GRK active site cleft that could likely be exploited to achieve more selectivity. However, neither compound inhibits GRKs more potently than their initial targets. This data provides the foundation for future efforts to rationally design even more potent and selective GRK inhibitors.

  3. Are there co-occurrence patterns that structure snake communities in Central Brazil? Existem padrões de coocorrência que estruturam comunidades de serpentes no Brasil Central?

    Directory of Open Access Journals (Sweden)

    FGR. França

    2007-02-01

    Full Text Available The main factors that structure Neotropical animal communities have been the subject of discussion in ecology communities. We used a set of null models to investigate the existence of structure in snake communities from the Cerrado in Central Brazil in relation to the co-occurrence of species and guilds concerning specific resources. We used fragments (conservation units inside the Distrito Federal and neighbor municipalities. In spite of recent human colonization in the region from the end of the 1950’s, intense habitat modification and fragmentation has taken place. Sixty three snake species are present in the Distrito Federal. Co-occurrence analysis of species and guilds associated to snake diets and habitats suggested a lack of organization. The homogeneity of habitats in Central Brazil and the minor importance of ecological effects can lead to random arrangement.Os processos que levam à estruturação de comunidades animais neotropicais têm sido sujeito de ampla discussão em ecologia de comunidades. Usou-se um conjunto de modelos nulos para investigar a existência de estrutura em comunidades de serpentes presentes no Cerrado do Brasil Central, em relação à coocorrência de espécies e de guildas relacionadas a recursos específicos. As localidades utilizadas para as análises representam fragmentos de habitats dentro do Distrito Federal e em municípios vizinhos. Apesar da recente colonização humana da região, datada para o final da década de 50, a intensidade da modificação e fragmentação dos habitats no Brasil Central têm sido enorme. Sessenta e três espécies de serpentes estão presentes no Distrito Federal. As análises dos padrões de coocorrência tanto para as espécies quanto para guildas relativas à dieta e ao uso do ambiente sugeriram ausência de organização. A homogeneidade dos ambientes no Brasil Central e a baixa importância de efeitos ecológicos podem levar ao arranjo randômico.

  4. Delineation of structures favourable to groundwater occurrence ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    local geology, bore well data and other available information in order to improve the reliability of interpretation. 1. ... out some preliminary seismic surveys to determine the lateral ... (Earth Planet. Sci.), 113 ... geological feature of the area is the contact between sandstone .... Scientist, National Geophysical Research Institute,.

  5. Structure-based prediction and identification of 4-epimerization activity of phosphate sugars in class II aldolases.

    Science.gov (United States)

    Lee, Seon-Hwa; Hong, Seung-Hye; An, Jung-Ung; Kim, Kyoung-Rok; Kim, Dong-Eun; Kang, Lin-Woo; Oh, Deok-Kun

    2017-05-16

    Sugar 4-epimerization reactions are important for the production of rare sugars and their derivatives, which have various potential industrial applications. For example, the production of tagatose, a functional sweetener, from fructose by sugar 4-epimerization is currently constrained because a fructose 4-epimerase does not exist in nature. We found that class II D-fructose-1,6-bisphosphate aldolase (FbaA) catalyzed the 4-epimerization of D-fructose-6-phosphate (F6P) to D-tagatose-6-phosphate (T6P) based on the prediction via structural comparisons with epimerase and molecular docking and the identification of the condensed products of C3 sugars. In vivo, the 4-epimerization activity of FbaA is normally repressed. This can be explained by our results showing the catalytic efficiency of D-fructose-6-phosphate kinase for F6P phosphorylation was significantly higher than that of FbaA for F6P epimerization. Here, we identified the epimerization reactions and the responsible catalytic residues through observation of the reactions of FbaA and L-rhamnulose-1-phosphate aldolases (RhaD) variants with substituted catalytic residues using different substrates. Moreover, we obtained detailed potential epimerization reaction mechanism of FbaA and a general epimerization mechanism of the class II aldolases L-fuculose-1-phosphate aldolase, RhaD, and FbaA. Thus, class II aldolases can be used as 4-epimerases for the stereo-selective synthesis of valuable carbohydrates.

  6. Structure-selective hot-spot Raman enhancement for direct identification and detection of trace penicilloic acid allergen in penicillin.

    Science.gov (United States)

    Zhang, Liying; Jin, Yang; Mao, Hui; Zheng, Lei; Zhao, Jiawei; Peng, Yan; Du, Shuhu; Zhang, Zhongping

    2014-08-15

    Trace penicilloic acid allergen frequently leads to various fatal immune responses to many patients, but it is still a challenge to directly discriminate and detect its residue in penicillin by a chemosensing way. Here, we report that silver-coated gold nanoparticles (Au@Ag NPs) exhibit a structure-selective hot-spot Raman enhancement capability for direct identification and detection of trace penicilloic acid in penicillin. It has been demonstrated that penicilloic acid can very easily link Au@Ag NPs together by its two carboxyl groups, locating itself spontaneously at the interparticle of Au@Ag NPs to form strong Raman hot-spot. At the critical concentration inducing the nanoparticle aggregation, Raman-enhanced effect of penicilloic acid is ~60,000 folds higher than that of penicillin. In particular, the selective Raman enhancement to the two carboxyl groups makes the peak of carboxyl group at C6 of penicilloic acid appear as a new Raman signal due to the opening of β-lactam ring of penicillin. The surface-enhanced Raman scattering (SERS) nanoparticle sensor reaches a sensitive limit lower than the prescribed 1.0‰ penicilloic acid residue in penicillin. The novel strategy to examine allergen is more rapid, convenient and inexpensive than the conventional separation-based assay methods. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Identification and Characterization of CINPA1 Metabolites Facilitates Structure-Activity Studies of the Constitutive Androstane Receptor

    Science.gov (United States)

    Cherian, Milu T.; Yang, Lei; Chai, Sergio C.; Lin, Wenwei

    2016-01-01

    The constitutive androstane receptor (CAR) regulates the expression of genes involved in drug metabolism and other processes. A specific inhibitor of CAR is critical for modulating constitutive CAR activity. We recently described a specific small-molecule inhibitor of CAR, CINPA1 (ethyl (5-(diethylglycyl)-10,11-dihydro-5H-dibenzo[b,f]azepin-3-yl)carbamate), which is capable of reducing CAR-mediated transcription by changing the coregulator recruitment pattern and reducing CAR occupancy at the promoter regions of its target genes. In this study, we showed that CINPA1 is converted to two main metabolites in human liver microsomes. By using cell-based reporter gene and biochemical coregulator recruitment assays, we showed that although metabolite 1 was very weak in inhibiting CAR function and disrupting CAR-coactivator interaction, metabolite 2 was inactive in this regard. Docking studies using the CAR ligand-binding domain structure showed that although CINPA1 and metabolite 1 can bind in the CAR ligand-binding pocket, metabolite 2 may be incapable of the molecular interactions required for binding. These results indicate that the metabolites of CINPA1 may not interfere with the action of CINPA1. We also used in vitro enzyme assays to identify the cytochrome P450 enzymes responsible for metabolizing CINPA1 in human liver microsomes and showed that CINPA1 was first converted to metabolite 1 by CYP3A4 and then further metabolized by CYP2D6 to metabolite 2. Identification and characterization of the metabolites of CINPA1 enabled structure-activity relationship studies of this family of small molecules and provided information to guide in vivo pharmacological studies. PMID:27519550

  8. Identification and Characterization of CINPA1 Metabolites Facilitates Structure-Activity Studies of the Constitutive Androstane Receptor.

    Science.gov (United States)

    Cherian, Milu T; Yang, Lei; Chai, Sergio C; Lin, Wenwei; Chen, Taosheng

    2016-11-01

    The constitutive androstane receptor (CAR) regulates the expression of genes involved in drug metabolism and other processes. A specific inhibitor of CAR is critical for modulating constitutive CAR activity. We recently described a specific small-molecule inhibitor of CAR, CINPA1 (ethyl (5-(diethylglycyl)-10,11-dihydro-5H-dibenzo[b,f]azepin-3-yl)carbamate), which is capable of reducing CAR-mediated transcription by changing the coregulator recruitment pattern and reducing CAR occupancy at the promoter regions of its target genes. In this study, we showed that CINPA1 is converted to two main metabolites in human liver microsomes. By using cell-based reporter gene and biochemical coregulator recruitment assays, we showed that although metabolite 1 was very weak in inhibiting CAR function and disrupting CAR-coactivator interaction, metabolite 2 was inactive in this regard. Docking studies using the CAR ligand-binding domain structure showed that although CINPA1 and metabolite 1 can bind in the CAR ligand-binding pocket, metabolite 2 may be incapable of the molecular interactions required for binding. These results indicate that the metabolites of CINPA1 may not interfere with the action of CINPA1. We also used in vitro enzyme assays to identify the cytochrome P450 enzymes responsible for metabolizing CINPA1 in human liver microsomes and showed that CINPA1 was first converted to metabolite 1 by CYP3A4 and then further metabolized by CYP2D6 to metabolite 2. Identification and characterization of the metabolites of CINPA1 enabled structure-activity relationship studies of this family of small molecules and provided information to guide in vivo pharmacological studies. Copyright © 2016 by The American Society for Pharmacology and Experimental Therapeutics.

  9. Genome-wide identification and structure-function studies of proteases and protease inhibitors in Cicer arietinum (chickpea).

    Science.gov (United States)

    Sharma, Ranu; Suresh, C G

    2015-01-01

    Proteases are a family of enzymes present in almost all living organisms. In plants they are involved in many biological processes requiring stress response in situations such as water deficiency, pathogen attack, maintaining protein content of the cell, programmed cell death, senescence, reproduction and many more. Similarly, protease inhibitors (PIs) are involved in various important functions like suppression of invasion by pathogenic nematodes, inhibition of spores-germination and mycelium growth of Alternaria alternata and response to wounding and fungal attack. As much as we know, no genome-wide study of proteases together with proteinaceous PIs is reported in any of the sequenced genomes till now. Phylogenetic studies and domain analysis of proteases were carried out to understand the molecular evolution as well as gene and protein features. Structural analysis was carried out to explore the binding mode and affinity of PIs for cognate proteases and prolyl oligopeptidase protease with inhibitor ligand. In the study reported here, a significant number of proteases and PIs were identified in chickpea genome. The gene expression profiles of proteases and PIs in five different plant tissues revealed a differential expression pattern in more than one plant tissue. Molecular dynamics studies revealed the formation of stable complex owing to increased number of protein-ligand and inter and intramolecular protein-protein hydrogen bonds. The genome-wide identification, characterization, evolutionary understanding, gene expression, and structural analysis of proteases and PIs provide a framework for future analysis when defining their roles in stress response and developing a more stress tolerant variety of chickpea. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Identification of AKB-48 and 5F-AKB-48 Metabolites in Authentic Human Urine Samples Using Human Liver Microsomes and Time of Flight Mass Spectrometry

    OpenAIRE

    Vikingsson, Svante; Josefsson, Martin; Green, Henrik

    2015-01-01

    The occurrence of structurally related synthetic cannabinoids makes the identification of unique markers of drug intake particularly challenging. The aim of this study was to identify unique and abundant metabolites of AKB-48 and 5F-AKB-48 for toxicological screening in urine. Investigations of authentic urine samples from forensic cases in combination with human liver microsome (HLM) experiments were used for identification of metabolites. HLM incubations of AKB-48 and 5F-AKB-48 along with 3...

  11. EVALUATING RELATIONSHIP AMONG RELIGIOSITY, SELF-ESTEEM, AND       IDENTIFICATION WITH TURKISH IDENTITY THROUGH STRUCTURAL EQUATION MODEL

    Directory of Open Access Journals (Sweden)

    Fatih ÖZDEMİR

    2013-07-01

    Full Text Available Social identity theory (Tajfel Turner, 1979 is commonly used in socialpsychology field since the late 1970s for explaining the person’s sense of who Iam. It provides a theoretical approach to identification with Turkish identity asnational identity. Conservatism and religiosity aremain values/norms of Turkishculture (Cagaptay, 2006; Imamoglu, 2002; Hofstede,2001, and they influencesocial behaviors of Turkish population. Also, according to social identity theory,identification with a positive social group, and internalizing its norms or valueshave a positive effect on the person’s self-concepts (Tajfel, 1978. Therefore itcan be said, this identification will increase theself-esteem level of groupmember. Moreover, the effects of demographic variables on individual’s socialbehaviors cannot be ignored as political affiliation, ethnic identity, education, age,sex and income. In this study, authors have analyzed relationship among thesevariables in different way, and have tested predictive power of religiosity, andself-esteem on identification with Turkish identity. Study has been performedwith Middle East Technical University students (N=341 and Religious AttitudeScale (Ok, 2011, Self-Esteem Scale (Rosenberg, 1965 and Social Identity Scale(Cinnirella, 1998 are main materials. In order tofigure out the effects ofreligiosity, and self-esteem on identification withTurkish identity, authors havecreated a structural equation model. Firstly, theyhave tested their measurementmodel. Confirmatory factor analysis has yielded good fit of the confirmatorymodel in the data [χ2 (24, N = 341 = 30.23, p=.17, RMSEA = .03, GFI =.98,AGFI = .96, CFI =1, NNFI = .99]. In addition, the structural model has yieldedgood fit of the structural model in the data [χ2 (17, N = 341 = 19.19, p=.32,RMSEA = .02, GFI = .99, AGFI = .97, CFI =1, NNFI =1]. Religiosity, and self-esteem have significantly predicted identificationwith Turkish identity.

  12. Identification of putative estrogen receptor-mediated endocrine disrupting chemicals using QSAR- and structure-based virtual screening approaches

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Liying; Sedykh, Alexander; Tripathi, Ashutosh [Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC (United States); Zhu, Hao [The Rutgers Center for Computational and Integrative Biology, Rutgers University, Camden, NJ (United States); Department of Chemistry, Rutgers University, Camden, NJ (United States); Afantitis, Antreas; Mouchlis, Varnavas D.; Melagraki, Georgia [NovaMechanics Ltd., Nicosia (Cyprus); Rusyn, Ivan, E-mail: iir@unc.edu [Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, NC (United States); Tropsha, Alexander, E-mail: alex_tropsha@unc.edu [Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC (United States)

    2013-10-01

    Identification of endocrine disrupting chemicals is one of the important goals of environmental chemical hazard screening. We report on the development of validated in silico predictors of chemicals likely to cause estrogen receptor (ER)-mediated endocrine disruption to facilitate their prioritization for future screening. A database of relative binding affinity of a large number of ERα and/or ERβ ligands was assembled (546 for ERα and 137 for ERβ). Both single-task learning (STL) and multi-task learning (MTL) continuous quantitative structure–activity relationship (QSAR) models were developed for predicting ligand binding affinity to ERα or ERβ. High predictive accuracy was achieved for ERα binding affinity (MTL R{sup 2} = 0.71, STL R{sup 2} = 0.73). For ERβ binding affinity, MTL models were significantly more predictive (R{sup 2} = 0.53, p < 0.05) than STL models. In addition, docking studies were performed on a set of ER agonists/antagonists (67 agonists and 39 antagonists for ERα, 48 agonists and 32 antagonists for ERβ, supplemented by putative decoys/non-binders) using the following ER structures (in complexes with respective ligands) retrieved from the Protein Data Bank: ERα agonist (PDB ID: 1L2I), ERα antagonist (PDB ID: 3DT3), ERβ agonist (PDB ID: 2NV7), and ERβ antagonist (PDB ID: 1L2J). We found that all four ER conformations discriminated their corresponding ligands from presumed non-binders. Finally, both QSAR models and ER structures were employed in parallel to virtually screen several large libraries of environmental chemicals to derive a ligand- and structure-based prioritized list of putative estrogenic compounds to be used for in vitro and in vivo experimental validation. - Highlights: • This is the largest curated dataset inclusive of ERα and β (the latter is unique). • New methodology that for the first time affords acceptable ERβ models. • A combination of QSAR and docking enables prediction of affinity and function.

  13. Identification of putative estrogen receptor-mediated endocrine disrupting chemicals using QSAR- and structure-based virtual screening approaches

    International Nuclear Information System (INIS)

    Zhang, Liying; Sedykh, Alexander; Tripathi, Ashutosh; Zhu, Hao; Afantitis, Antreas; Mouchlis, Varnavas D.; Melagraki, Georgia; Rusyn, Ivan; Tropsha, Alexander

    2013-01-01

    Identification of endocrine disrupting chemicals is one of the important goals of environmental chemical hazard screening. We report on the development of validated in silico predictors of chemicals likely to cause estrogen receptor (ER)-mediated endocrine disruption to facilitate their prioritization for future screening. A database of relative binding affinity of a large number of ERα and/or ERβ ligands was assembled (546 for ERα and 137 for ERβ). Both single-task learning (STL) and multi-task learning (MTL) continuous quantitative structure–activity relationship (QSAR) models were developed for predicting ligand binding affinity to ERα or ERβ. High predictive accuracy was achieved for ERα binding affinity (MTL R 2 = 0.71, STL R 2 = 0.73). For ERβ binding affinity, MTL models were significantly more predictive (R 2 = 0.53, p < 0.05) than STL models. In addition, docking studies were performed on a set of ER agonists/antagonists (67 agonists and 39 antagonists for ERα, 48 agonists and 32 antagonists for ERβ, supplemented by putative decoys/non-binders) using the following ER structures (in complexes with respective ligands) retrieved from the Protein Data Bank: ERα agonist (PDB ID: 1L2I), ERα antagonist (PDB ID: 3DT3), ERβ agonist (PDB ID: 2NV7), and ERβ antagonist (PDB ID: 1L2J). We found that all four ER conformations discriminated their corresponding ligands from presumed non-binders. Finally, both QSAR models and ER structures were employed in parallel to virtually screen several large libraries of environmental chemicals to derive a ligand- and structure-based prioritized list of putative estrogenic compounds to be used for in vitro and in vivo experimental validation. - Highlights: • This is the largest curated dataset inclusive of ERα and β (the latter is unique). • New methodology that for the first time affords acceptable ERβ models. • A combination of QSAR and docking enables prediction of affinity and function. • The results

  14. Output-only cyclo-stationary linear-parameter time-varying stochastic subspace identification method for rotating machinery and spinning structures

    Science.gov (United States)

    Velazquez, Antonio; Swartz, R. Andrew

    2015-02-01

    Economical maintenance and operation are critical issues for rotating machinery and spinning structures containing blade elements, especially large slender dynamic beams (e.g., wind turbines). Structural health monitoring systems represent promising instruments to assure reliability and good performance from the dynamics of the mechanical systems. However, such devices have not been completely perfected for spinning structures. These sensing technologies are typically informed by both mechanistic models coupled with data-driven identification techniques in the time and/or frequency domain. Frequency response functions are popular but are difficult to realize autonomously for structures of higher order, especially when overlapping frequency content is present. Instead, time-domain techniques have shown to possess powerful advantages from a practical point of view (i.e. low-order computational effort suitable for real-time or embedded algorithms) and also are more suitable to differentiate closely-related modes. Customarily, time-varying effects are often neglected or dismissed to simplify this analysis, but such cannot be the case for sinusoidally loaded structures containing spinning multi-bodies. A more complex scenario is constituted when dealing with both periodic mechanisms responsible for the vibration shaft of the rotor-blade system and the interaction of the supporting substructure. Transformations of the cyclic effects on the vibrational data can be applied to isolate inertial quantities that are different from rotation-generated forces that are typically non-stationary in nature. After applying these transformations, structural identification can be carried out by stationary techniques via data-correlated eigensystem realizations. In this paper, an exploration of a periodic stationary or cyclo-stationary subspace identification technique is presented here for spinning multi-blade systems by means of a modified Eigensystem Realization Algorithm (ERA) via

  15. Identification and design of novel polymer-based mechanical transducers: A nano-structural model for thin film indentation

    Energy Technology Data Exchange (ETDEWEB)

    Villanueva, Joshua; Huang, Qian; Sirbuly, Donald J., E-mail: dsirbuly@ucsd.edu [Department of NanoEngineering, University of California San Diego, La Jolla, California 92093 (United States)

    2014-09-14

    Mechanical characterization is important for understanding small-scale systems and developing devices, particularly at the interface of biology, medicine, and nanotechnology. Yet, monitoring sub-surface forces is challenging with current technologies like atomic force microscopes (AFMs) or optical tweezers due to their probe sizes and sophisticated feedback mechanisms. An alternative transducer design relying on the indentation mechanics of a compressible thin polymer would be an ideal system for more compact and versatile probes, facilitating measurements in situ or in vivo. However, application-specific tuning of a polymer's mechanical properties can be burdensome via experimental optimization. Therefore, efficient transducer design requires a fundamental understanding of how synthetic parameters such as the molecular weight and grafting density influence the bulk material properties that determine the force response. In this work, we apply molecular-level polymer scaling laws to a first order elastic foundation model, relating the conformational state of individual polymer chains to the macroscopic compression of thin film systems. A parameter sweep analysis was conducted to observe predicted model trends under various system conditions and to understand how nano-structural elements influence the material stiffness. We validate the model by comparing predicted force profiles to experimental AFM curves for a real polymer system and show that it has reasonable predictive power for initial estimates of the force response, displaying excellent agreement with experimental force curves. We also present an analysis of the force sensitivity of an example transducer system to demonstrate identification of synthetic protocols based on desired mechanical properties. These results highlight the usefulness of this simple model as an aid for the design of a new class of compact and tunable nanomechanical force transducers.

  16. Identification and design of novel polymer-based mechanical transducers: A nano-structural model for thin film indentation

    International Nuclear Information System (INIS)

    Villanueva, Joshua; Huang, Qian; Sirbuly, Donald J.

    2014-01-01

    Mechanical characterization is important for understanding small-scale systems and developing devices, particularly at the interface of biology, medicine, and nanotechnology. Yet, monitoring sub-surface forces is challenging with current technologies like atomic force microscopes (AFMs) or optical tweezers due to their probe sizes and sophisticated feedback mechanisms. An alternative transducer design relying on the indentation mechanics of a compressible thin polymer would be an ideal system for more compact and versatile probes, facilitating measurements in situ or in vivo. However, application-specific tuning of a polymer's mechanical properties can be burdensome via experimental optimization. Therefore, efficient transducer design requires a fundamental understanding of how synthetic parameters such as the molecular weight and grafting density influence the bulk material properties that determine the force response. In this work, we apply molecular-level polymer scaling laws to a first order elastic foundation model, relating the conformational state of individual polymer chains to the macroscopic compression of thin film systems. A parameter sweep analysis was conducted to observe predicted model trends under various system conditions and to understand how nano-structural elements influence the material stiffness. We validate the model by comparing predicted force profiles to experimental AFM curves for a real polymer system and show that it has reasonable predictive power for initial estimates of the force response, displaying excellent agreement with experimental force curves. We also present an analysis of the force sensitivity of an example transducer system to demonstrate identification of synthetic protocols based on desired mechanical properties. These results highlight the usefulness of this simple model as an aid for the design of a new class of compact and tunable nanomechanical force transducers.

  17. Active Longitude and Coronal Mass Ejection Occurrences

    International Nuclear Information System (INIS)

    Gyenge, N.; Kiss, T. S.; Erdélyi, R.; Singh, T.; Srivastava, A. K.

    2017-01-01

    The spatial inhomogeneity of the distribution of coronal mass ejection (CME) occurrences in the solar atmosphere could provide a tool to estimate the longitudinal position of the most probable CME-capable active regions in the Sun. The anomaly in the longitudinal distribution of active regions themselves is often referred to as active longitude (AL). In order to reveal the connection between the AL and CME spatial occurrences, here we investigate the morphological properties of active regions. The first morphological property studied is the separateness parameter, which is able to characterize the probability of the occurrence of an energetic event, such as a solar flare or CME. The second morphological property is the sunspot tilt angle. The tilt angle of sunspot groups allows us to estimate the helicity of active regions. The increased helicity leads to a more complex buildup of the magnetic structure and also can cause CME eruption. We found that the most complex active regions appear near the AL and that the AL itself is associated with the most tilted active regions. Therefore, the number of CME occurrences is higher within the AL. The origin of the fast CMEs is also found to be associated with this region. We concluded that the source of the most probably CME-capable active regions is at the AL. By applying this method, we can potentially forecast a flare and/or CME source several Carrington rotations in advance. This finding also provides new information for solar dynamo modeling.

  18. Active Longitude and Coronal Mass Ejection Occurrences

    Energy Technology Data Exchange (ETDEWEB)

    Gyenge, N.; Kiss, T. S.; Erdélyi, R. [Solar Physics and Space Plasmas Research Centre (SP2RC), School of Mathematics and Statistics, University of Sheffield Hounsfield Road, Hicks Building, Sheffield S3 7RH (United Kingdom); Singh, T.; Srivastava, A. K., E-mail: n.g.gyenge@sheffield.ac.uk [Department of Physics, Indian Institute of Technology (Banaras Hindu University), Varanasi (India)

    2017-03-20

    The spatial inhomogeneity of the distribution of coronal mass ejection (CME) occurrences in the solar atmosphere could provide a tool to estimate the longitudinal position of the most probable CME-capable active regions in the Sun. The anomaly in the longitudinal distribution of active regions themselves is often referred to as active longitude (AL). In order to reveal the connection between the AL and CME spatial occurrences, here we investigate the morphological properties of active regions. The first morphological property studied is the separateness parameter, which is able to characterize the probability of the occurrence of an energetic event, such as a solar flare or CME. The second morphological property is the sunspot tilt angle. The tilt angle of sunspot groups allows us to estimate the helicity of active regions. The increased helicity leads to a more complex buildup of the magnetic structure and also can cause CME eruption. We found that the most complex active regions appear near the AL and that the AL itself is associated with the most tilted active regions. Therefore, the number of CME occurrences is higher within the AL. The origin of the fast CMEs is also found to be associated with this region. We concluded that the source of the most probably CME-capable active regions is at the AL. By applying this method, we can potentially forecast a flare and/or CME source several Carrington rotations in advance. This finding also provides new information for solar dynamo modeling.

  19. Active Longitude and Coronal Mass Ejection Occurrences

    Science.gov (United States)

    Gyenge, N.; Singh, T.; Kiss, T. S.; Srivastava, A. K.; Erdélyi, R.

    2017-03-01

    The spatial inhomogeneity of the distribution of coronal mass ejection (CME) occurrences in the solar atmosphere could provide a tool to estimate the longitudinal position of the most probable CME-capable active regions in the Sun. The anomaly in the longitudinal distribution of active regions themselves is often referred to as active longitude (AL). In order to reveal the connection between the AL and CME spatial occurrences, here we investigate the morphological properties of active regions. The first morphological property studied is the separateness parameter, which is able to characterize the probability of the occurrence of an energetic event, such as a solar flare or CME. The second morphological property is the sunspot tilt angle. The tilt angle of sunspot groups allows us to estimate the helicity of active regions. The increased helicity leads to a more complex buildup of the magnetic structure and also can cause CME eruption. We found that the most complex active regions appear near the AL and that the AL itself is associated with the most tilted active regions. Therefore, the number of CME occurrences is higher within the AL. The origin of the fast CMEs is also found to be associated with this region. We concluded that the source of the most probably CME-capable active regions is at the AL. By applying this method, we can potentially forecast a flare and/or CME source several Carrington rotations in advance. This finding also provides new information for solar dynamo modeling.

  20. Identification of the Genes Involved in the Biofilm-like Structures on Actinomyces oris K20, a Clinical Isolate from an Apical Lesion

    Science.gov (United States)

    2013-01-01

    bacteria in clinically asymptomatic periapical pathosis. J Endod 1990;16:534–8. 5. Nair PNR. On the causes of persistent apical periodontitis : a review...Identification of the Genes Involved in the Biofilm-like Structures on Actinomyces oris K20, a Clinical Isolate from an Apical Lesion Chiho Mashimo...Actinomyces oris K20. (J Endod 2013;39:44–48) Key Words Actinomyces oris, apical abscess, biofilm, polysac- charide deacetylase, transposon mutagenesis

  1. An application of the geophysical methods and ALS DTM for the identification of the geological structure in the Kraśnik region - Lublin Upland, Poland

    Science.gov (United States)

    Kamiński, Mirosław

    2017-11-01

    The purpose of the study was the assessment of the viability of selected geophysical methods and the Airborne Laser Scanning (ALS) for the identification and interpretation of the geological structure. The studied area is covered with a dense forest. For this reason, the ALS numerical terrain model was applied for the analysis of the topography. Three geophysical methods were used: gravimetric, in the form of a semi-detailed gravimetric photograph, Vertical Electrical Sounding (VES), and Electrical Resistivity Tomography (ERT). The numerical terrain model enabled the identification of Jurassic limestone outcrops and interpretation of the directions of the faults network. The geological interpretation of the digitally processed gravimetric data enabled the determination of the spatial orientation of the synclines and anticlines axes and of the course directions of main faults. Vertical Electrical Sounding carried along the section line perpendicular to the Gościeradów anticline axis enabled the interpretation of the lithology of this structure and identification of its complex tectonic structure. The shallow geophysical surveys using the ERT method enabled the estimation of the thickness of Quaternary formations deposited unconformably on the highly eroded Jurassic limestone outcrop. The lithology of Quaternary, Cretaceous and Jurassic rocks was also interpreted.

  2. An application of the geophysical methods and ALS DTM for the identification of the geological structure in the Kraśnik region – Lublin Upland, Poland

    Directory of Open Access Journals (Sweden)

    Kamiński Mirosław

    2017-01-01

    Full Text Available The purpose of the study was the assessment of the viability of selected geophysical methods and the Airborne Laser Scanning (ALS for the identification and interpretation of the geological structure. The studied area is covered with a dense forest. For this reason, the ALS numerical terrain model was applied for the analysis of the topography. Three geophysical methods were used: gravimetric, in the form of a semi-detailed gravimetric photograph, Vertical Electrical Sounding (VES, and Electrical Resistivity Tomography (ERT. The numerical terrain model enabled the identification of Jurassic limestone outcrops and interpretation of the directions of the faults network. The geological interpretation of the digitally processed gravimetric data enabled the determination of the spatial orientation of the synclines and anticlines axes and of the course directions of main faults. Vertical Electrical Sounding carried along the section line perpendicular to the Gościeradów anticline axis enabled the interpretation of the lithology of this structure and identification of its complex tectonic structure. The shallow geophysical surveys using the ERT method enabled the estimation of the thickness of Quaternary formations deposited unconformably on the highly eroded Jurassic limestone outcrop. The lithology of Quaternary, Cretaceous and Jurassic rocks was also interpreted.

  3. Factor structure and invariance test of the alcohol use disorder identification test (AUDIT): Comparison and further validation in a U.S. and Philippines college student sample.

    Science.gov (United States)

    Tuliao, Antover P; Landoy, Bernice Vania N; McChargue, Dennis E

    2016-01-01

    The Alcohol Use Disorder Identification Test's factor structure varies depending on population and culture. Because of this inconsistency, this article examined the factor structure of the test and conducted a factorial invariance test between a U.S. and a Philippines college sample. Confirmatory factor analyses indicated that a three-factor solution outperforms the one- and two-factor solution in both samples. Factorial invariance analyses further supports the confirmatory findings by showing that factor loadings were generally invariant across groups; however, item intercepts show non-invariance. Country differences between factors show that Filipino consumption factor mean scores were significantly lower than their U.S. counterparts.

  4. Adaptive operational modal identification for slow linear time-varying structures based on frozen-in coefficient method and limited memory recursive principal component analysis

    Science.gov (United States)

    Wang, Cheng; Guan, Wei; Wang, J. Y.; Zhong, Bineng; Lai, Xiongming; Chen, Yewang; Xiang, Liang

    2018-02-01

    To adaptively identify the transient modal parameters for linear weakly damped structures with slow time-varying characteristics under unmeasured stationary random ambient loads, this paper proposes a novel operational modal analysis (OMA) method based on the frozen-in coefficient method and limited memory recursive principal component analysis (LMRPCA). In the modal coordinate, the random vibration response signals of mechanical weakly damped structures can be decomposed into the inner product of modal shapes and modal responses, from which the natural frequencies and damping ratios can be well acquired by single-degree-of-freedom (SDOF) identification approach such as FFT. Hence, for the OMA method based on principal component analysis (PCA), it becomes very crucial to examine the relation between the transformational matrix and the modal shapes matrix, to find the association between the principal components (PCs) matrix and the modal responses matrix, and to turn the operational modal parameter identification problem into PCA of the stationary random vibration response signals of weakly damped mechanical structures. Based on the theory of "time-freezing", the method of frozen-in coefficient, and the assumption of "short time invariant" and "quasistationary", the non-stationary random response signals of the weakly damped and slow linear time-varying structures (LTV) can approximately be seen as the stationary random response time series of weakly damped and linear time invariant structures (LTI) in a short interval. Thus, the adaptive identification of time-varying operational modal parameters is turned into decompositing the PCs of stationary random vibration response signals subsection of weakly damped mechanical structures after choosing an appropriate limited memory window. Finally, a three-degree-of-freedom (DOF) structure with weakly damped and slow time-varying mass is presented to illustrate this method of identification. Results show that the LMRPCA

  5. Identification of the chemical constituents of Chinese medicine Yi-Xin-Shu capsule by molecular feature orientated precursor ion selection and tandem mass spectrometry structure elucidation.

    Science.gov (United States)

    Wang, Hong-ping; Chen, Chang; Liu, Yan; Yang, Hong-Jun; Wu, Hong-Wei; Xiao, Hong-Bin

    2015-11-01

    The incomplete identification of the chemical components of traditional Chinese medicinal formula has been one of the bottlenecks in the modernization of traditional Chinese medicine. Tandem mass spectrometry has been widely used for the identification of chemical substances. Current automatic tandem mass spectrometry acquisition, where precursor ions were selected according to their signal intensity, encounters a drawback in chemical substances identification when samples contain many overlapping signals. Compounds in minor or trace amounts could not be identified because most tandem mass spectrometry information was lost. Herein, a molecular feature orientated precursor ion selection and tandem mass spectrometry structure elucidation method for complex Chinese medicine chemical constituent analysis was developed. The precursor ions were selected according to their two-dimensional characteristics of retention times and mass-to-charge ratio ranges from herbal compounds, so that all precursor ions from herbal compounds were included and more minor chemical constituents in Chinese medicine were identified. Compared to the conventional automatic tandem mass spectrometry setups, the approach is novel and can overcome the drawback for chemical substances identification. As an example, 276 compounds from the Chinese Medicine of Yi-Xin-Shu capsule were identified. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Identification of self-consistent modulons from bacterial microarray expression data with the help of structured regulon gene sets

    KAUST Repository

    Permina, Elizaveta A.

    2013-01-01

    Identification of bacterial modulons from series of gene expression measurements on microarrays is a principal problem, especially relevant for inadequately studied but practically important species. Usage of a priori information on regulatory interactions helps to evaluate parameters for regulatory subnetwork inference. We suggest a procedure for modulon construction where a seed regulon is iteratively updated with genes having expression patterns similar to those for regulon member genes. A set of genes essential for a regulon is used to control modulon updating. Essential genes for a regulon were selected as a subset of regulon genes highly related by different measures to each other. Using Escherichia coli as a model, we studied how modulon identification depends on the data, including the microarray experiments set, the adopted relevance measure and the regulon itself. We have found that results of modulon identification are highly dependent on all parameters studied and thus the resulting modulon varies substantially depending on the identification procedure. Yet, modulons that were identified correctly displayed higher stability during iterations, which allows developing a procedure for reliable modulon identification in the case of less studied species where the known regulatory interactions are sparse. Copyright © 2013 Taylor & Francis.

  7. The Occurrence of Erionite at Yucca Mountain

    International Nuclear Information System (INIS)

    NA

    2004-01-01

    The naturally-occurring zeolite mineral erionite has a fibrous morphology and is a known human carcinogen (inhalation hazard). Erionite has been found typically in very small quantities and restricted occurrences in the course of mineralogic characterization of Yucca Mountain as a host for a high-level nuclear waste repository. The first identification of erionite was made in 1984 on the basis of morphology and chemical composition and later confirmed by X-ray diffraction analysis. It was found in the lower vitrophyre (Tptpv3) of the Topopah Spring Tuff in a borehole sidewall sample. Most erionite occurrences identified at Yucca Mountain are in the Topopah Spring Tuff, within an irregular zone of transition between the lower boundary of devitrified tuff and underlying glassy tuff. This zone is fractured and contains intermingled devitrified and vitric tuff. In 1997, a second host of erionite mineralization was identified in the Exploratory Studies Facility within and adjacent to a high-angle fracture/breccia zone transgressing the boundary between the lowermost devitrified tuff (Tpcplnc) and underlying moderately welded vitric tuff (Tpcpv2) of the Tiva Canyon Tuff. The devitrified-vitric transition zones where erionite is found tend to have complex secondary-mineral assemblages, some of very localized occurrence. Secondary minerals in addition to erionite may include smectite, heulandite-clinoptilolite, chabazite, opal-A, opal-CT, cristobalite, quartz, kenyaite, and moganite. Incipient devitrification within the Topopah Spring Tuff transition zone includes patches that are highly enriched in potassium feldspar relative to the precursor volcanic glass. Geochemical conditions during glass alteration may have led to local evolution of potassium-rich fluids. Thermodynamic modeling of zeolite stability shows that erionite and chabazite stability fields occur only at aqueous K concentrations much higher than in present Yucca Mountain waters. The association of erionite

  8. The Study of the Effect of Syntactic Complexity of Noun and Verb Phrase Structure on the Occurrence of Stuttering in 4-6 Year Pre-School Stuttering Persian Children

    Directory of Open Access Journals (Sweden)

    Abbas Ali Ahangar

    2013-04-01

    Full Text Available Objective: The purpose of the present research was to investigate the effect of syntactic complexity of noun phrase and verb phrase on the occurrence of stuttering in 4-6 year Persian speaking children with stuttering. Materials & Methods: This descriptive-analytic research was done on 15 stuttering children, consisting of 12 boys and 3 girls, 4 to 6 years old monolingual Persian speaking who referred to Javad-Ol-Aemmeh speech therapy clinic in Mashhad city. The sampling approach was simple (available sampling method. To do this research, sampling was carried out in a quiet home of speech therapy where there were just the speech therapist, the parent, the child and the researcher. While speaking, the speech of the children was recorded by an MP3 with Creative brand. Finally, a 30-minute spontaneous speech sample was gathered from each of the given stuttering children. The children produced around 60 utterances during a verbal interaction with the speech therapist, parents (mother or father or the researcher. Then the produced spontaneous speech sample by any of these stuttering children was transcribed on paper. The data were analyzed only as groups and not individually. The data were analyzed using SPSS software and Paired T-test method. Results: The group analyses showed significant differences between fluent and stuttered utterances in terms of syntactic complexity of noun and verb phrase structures. Also, the results confirm that at phrasal level, in noun phrases, based on their three functions as subject, direct object and object of preposition, there is a meaningful relationship between the number of subject (P<0.001 and object of preposition (P=0.050 with the stuttering frequency. In verb phrases, based on the presence of the auxiliary verb, copula verb, and negative prefix, just there is a meaningful relationship between the presence of the auxiliary verb and the stuttering frequency (P=0.010. Conclusion: The research findings indicate

  9. Estruturas secretoras em cipó-d'alho (Mansoa standleyi (Steyerm. A. H. Gentry, Bignoniaceae: ocorrência e morfologia Secretory structures in cipó-d'alho (Mansoa standleyi (Steyerm. A. H. Gentry, Bignoniaceae: occurrence and morphology

    Directory of Open Access Journals (Sweden)

    Raimunda Conceição Vilhena-Potiguara

    2012-09-01

    Full Text Available Espécies de Mansoa são denominadas de "cipó-d'alho", por exalarem odor de alho das partes vegetativas e reprodutivas. Contudo, dados sobre morfologia e distribuição das estruturas secretoras presentes em Mansoa são escassos e ausentes para M. standleyi. O presente trabalho objetivou caracterizar a ocorrência e morfologia das estruturas secretoras do eixo vegetativo aéreo de M. standleyi. Para tanto, amostras da lâmina foliolar e de regiões nodais foram fixadas e submetidas às técnicas histológicas e de microscopia eletrônica de varredura. Testes histoquímicos, com os respectivos controles foram aplicados nas estruturas secretoras em fase secretora. Indivíduos de formigas e moscas, que visitavam a espécie foram amostrados, preservados e identificados por entomólogo. As estruturas secretoras do eixo vegetativo aéreo de M. standleyi estão representadas por tricomas glandulares dos tipos pateliformes e peltados. Todos com desenvolvimento assincrônico e presentes nas regiões nodais e lâmina foliolar, principalmente nas partes mais jovens. Nas regiões nodais, os tricomas formam um complexo secretor e, na lâmina foliolar, estão dispersos. As análises histoquímicas revelaram que os tricomas pateliformes são de fato nectários extraflorais e que os tricomas peltados, apresentam uma fração de alcaloides. Os visitantes das glândulas nodais correspondem a formigas Crematogaster (Formicidae e Ectatomma brunea (Vespoidea, Formicidae e moscas Oxysarcodexia (Sarcophagidae, subfamília Utitidae (Ulidiidae. Mansoa standleyi possui as estruturas secretoras do eixo vegetativo aéreo semelhantes às citadas pela literatura para Bignoniaceae, sendo esta a primeira vez, que um nectário extrafloral é descrito para a espécie.Species of Mansoa are called "cipó-d'alho" because of the smell of garlic that wafts from their vegetative and reproductive parts. Since data on the morphology and occurrence of their secretory structures are

  10. Identification of volatile and semivolatile compounds in chemical ionization GC-MS using a mass-to-structure (MTS) Search Engine with integral isotope pattern ranking.

    Science.gov (United States)

    Liao, Wenta; Draper, William M

    2013-02-21

    The mass-to-structure or MTS Search Engine is an Access 2010 database containing theoretical molecular mass information for 19,438 compounds assembled from common sources such as the Merck Index, pesticide and pharmaceutical compilations, and chemical catalogues. This database, which contains no experimental mass spectral data, was developed as an aid to identification of compounds in atmospheric pressure ionization (API)-LC-MS. This paper describes a powerful upgrade to this database, a fully integrated utility for filtering or ranking candidates based on isotope ratios and patterns. The new MTS Search Engine is applied here to the identification of volatile and semivolatile compounds including pesticides, nitrosoamines and other pollutants. Methane and isobutane chemical ionization (CI) GC-MS spectra were obtained from unit mass resolution mass spectrometers to determine MH(+) masses and isotope ratios. Isotopes were measured accurately with errors of Search Engine and details performance testing with over 50 model compounds.

  11. Identification of structural traits that increase the antimicrobial activity of a chimeric peptide of human β-defensins 2 and 3.

    Science.gov (United States)

    Spudy, Björn; Sönnichsen, Frank D; Waetzig, Georg H; Grötzinger, Joachim; Jung, Sascha

    2012-10-12

    Antimicrobial peptides participate in the first line of defence of many organisms against pathogens. In humans, the family of β-defensins plays a pivotal role in innate immunity. Two human β-defensins, β-defensin-2 and -3 (HBD2 and HBD3), show substantial sequence identity and structural similarity. However, HBD3 kills Staphylococcus (S.) aureus with a 4- to 8-fold higher efficiency compared to HBD2, whereas their activities against Escherichia (E.) coli are very similar. The generation of six HBD2/HBD3-chimeric molecules led to the identification of distinct molecular regions which mediate their divergent killing properties. One of the chimeras (chimera C3) killed both E. coli and S. aureus with an even higher efficacy compared to the wild-type molecules. Due to the broad spectrum of its antimicrobial activity against many human multidrug-resistant pathogens, this HBD2/HBD3-chimeric peptide represents a promising candidate for a new class of antibiotics. In order to investigate the structural basis of its exceptional antimicrobial activity, the peptide's tertiary structure was determined by NMR spectroscopy, which allowed its direct comparison to the published structures of HBD2 and HBD3 and the identification of the activity-increasing molecular features. Copyright © 2012 Elsevier Inc. All rights reserved.

  12. Identification, Characterization, and Three-Dimensional Structure of the Novel Circular Bacteriocin, Enterocin NKR-5-3B, from Enterococcus faecium.

    Science.gov (United States)

    Himeno, Kohei; Rosengren, K Johan; Inoue, Tomoko; Perez, Rodney H; Colgrave, Michelle L; Lee, Han Siean; Chan, Lai Y; Henriques, Sónia Troeira; Fujita, Koji; Ishibashi, Naoki; Zendo, Takeshi; Wilaipun, Pongtep; Nakayama, Jiro; Leelawatcharamas, Vichien; Jikuya, Hiroyuki; Craik, David J; Sonomoto, Kenji

    2015-08-11

    Enterocin NKR-5-3B, one of the multiple bacteriocins produced by Enterococcus faecium NKR-5-3, is a 64-amino acid novel circular bacteriocin that displays broad-spectrum antimicrobial activity. Here we report the identification, characterization, and three-dimensional nuclear magnetic resonance solution structure determination of enterocin NKR-5-3B. Enterocin NKR-5-3B is characterized by four helical segments that enclose a compact hydrophobic core, which together with its circular backbone impart high stability and structural integrity. We also report the corresponding structural gene, enkB, that encodes an 87-amino acid precursor peptide that undergoes a yet to be described enzymatic processing that involves adjacent cleavage and ligation of Leu(24) and Trp(87) to yield the mature (circular) enterocin NKR-5-3B.

  13. Dental Evidence in Forensic Identification – An Overview, Methodology and Present Status

    Science.gov (United States)

    Krishan, Kewal; Kanchan, Tanuj; Garg, Arun K

    2015-01-01

    Forensic odontology is primarily concerned with the use of teeth and oral structures for identification in a legal context. Various forensic odontology techniques help in the identification of the human remains in incidents such as terrorists’ attacks, airplane, train and road accidents, fires, mass murders, and natural disasters such as tsunamis, earth quakes and floods, etc. (Disaster Victim Identification-DVI). Dental structures are the hardest and well protected structures in the body. These structures resist decomposition and high temperatures and are among the last ones to disintegrate after death. The principal basis of the dental identification lies in the fact that no two oral cavities are alike and the teeth are unique to an individual. The dental evidence of the deceased recovered from the scene of crime/occurrence is compared with the ante-mortem records for identification. Dental features such as tooth morphology, variations in shape and size, restorations, pathologies, missing tooth, wear patterns, crowding of the teeth, colour and position of the tooth, rotations and other peculiar dental anomalies give every individual a unique identity. In absence of ante-mortem dental records for comparison, the teeth can help in the determination of age, sex, race/ethnicity, habits, occupations, etc. which can give further clues regarding the identity of the individuals. This piece of writing gives an overview of dental evidence, its use in forensic identification and its limitations. PMID:26312096

  14. Exudate gums: occurrence, production, and applications.

    Science.gov (United States)

    Verbeken, D; Dierckx, S; Dewettinck, K

    2003-11-01

    This paper presents a review of the industrially most relevant exudate gums: gum arabic, gum karya, and gum tragacanth. Exudate gums are obtained as the natural exudates of different tree species and exhibit unique properties in a wide variety of applications. This review covers the chemical structure, occurrence and production of the different gums. It also deals with the size and relative importance of the various players on the world market. Furthermore, it gives an overview of the main application fields of the different gums, both food and non-food.

  15. [Improvement in the species identification of Lactobacillus by using microculture test systems and data on its genome structure].

    Science.gov (United States)

    Likhacheva, A Iu; Sokolova, K Ia; Levanova, G F

    1995-01-01

    18 microanalytical media, used for the construction of a biochemical plate test system permitting the specific identification of bacteria of the genus Lactobacillus, were developed on the basis of data on the metabolic activity of these bacteria and their need of growth factors. As the results of studies made on 78 Lactobacillus strains with the use of traditional microbiological and gene-systematizing methods, the proposed test system was shown to be reliable and specific.

  16. Evaluation of pathogenic fungi occurrence in traumatogenic structures of freshwater fish Avaliação da ocorrência de fungos patogênicos em estruturas traumatogênicas de peixes fluviais

    Directory of Open Access Journals (Sweden)

    Fabio Caetano Oliveira Leme

    2011-04-01

    Full Text Available INTRODUCTION: Fungal infections in human skin, such as sporotrichosis, can occur after fish induced trauma. This work aimed to identify fungi in freshwater fish that are pathogenic to humans. METHODS: Extraction of dental arches from Serrassalmus maculatus (piranha and Hoplias malabaricus (wolf fish, stings from Pimelodus maculatus (mandis catfish, dorsal fin rays from Plagioscion spp. (corvina and Tilapia spp., for culture in Mycosel agar. Some cultures were submitted to DNA extraction for molecular identification by sequencing ITS-5.8S rDNA. RESULTS: Cultures identified most yeast as Candida spp., while sequencing also permitted the identification of Phoma spp. and Yarrowia lipolytica. CONCLUSIONS: While the search for S. schenckii was negative, the presence of fungus of the genera Phoma and Candida revealed the pathogenic potential of this infection route. The genus Phoma is involved in certain forms of phaeohyphomycosis, a subcutaneous mycosis caused by dematiaceous fungi, with reports of infections in human organs and systems. Traumatizing structures of some freshwater fish present pathogenic fungi and this may be an important infection route that must be considered in some regions of Brazil, since there are a large number of a fisherman in constant contact with traumatogenic fish.INTRODUÇÃO: Infecções fúngicas na pele humana (como a esporotricose podem se manifestar após traumatismos por peixes. O objetivo deste trabalho é procurar fungos patogênicos para o homem em peixes fluviais. MÉTODOS: Extração de arcadas dentárias Serrassalmus maculatus (piranha e Hoplias malabaricus (traíra, ferrões de Pimelodus maculatus (mandis, raios da nadadeira dorsal de Plagioscion spp. (corvina e Tilapia spp. para a realização do cultivo em agar Mycosel. Algumas culturas foram submetidas à extração de DNA para a identificação molecular pelo seqüenciamento da região ITS-5.8S do rDNA. RESULTADOS: As culturas mostraram que a maioria das

  17. First natural occurrence of coesite

    Science.gov (United States)

    Chao, E.C.T.; Shoemaker, E.M.; Madsen, B.M.

    1960-01-01

    Coesite, the high-pressure polymorph of SiO2, hitherto known only as a synthetic compound, is identified as an abundant mineral in sheared Coconino sandstone at Meteor Crater, Arizona. This natural occurrence has important bearing on the recognition of meteorite impact craters in quartz-bearing geologic formations.

  18. Human plague occurrences in Africa

    DEFF Research Database (Denmark)

    Neerinckx, Simon; Bertherat, Eric; Leirs, Herwig

    2010-01-01

    Plague remains a public health concern worldwide, but particularly in Africa. Despite the long-standing history of human plague, it is difficult to get a historical and recent overview of the general situation. We searched and screened available information sources on human plague occurrences in ...

  19. Diamond identification

    International Nuclear Information System (INIS)

    Lang, A.R.

    1979-01-01

    Methods of producing sets of records of the internal defects of diamonds as a means of identification of the gems by x-ray topography are described. To obtain the records one can either use (a) monochromatic x-radiation reflected at the Bragg angle from crystallographically equivalent planes of the diamond lattice structure, Bragg reflections from each such plane being recorded from a number of directions of view, or (b) white x-radiation incident upon the diamond in directions having a constant angular relationship to each equivalent axis of symmetry of the diamond lattice structure, Bragg reflections being recorded for each direction of the incident x-radiation. By either method an overall point-to-point three dimensional representation of the diamond is produced. (U.K.)

  20. Identification of the first small-molecule ligand of the neuronal receptor sortilin and structure determination of the receptor–ligand complex

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, Jacob Lauwring, E-mail: jla@mb.au.dk [Aarhus University, Gustav Wieds Vej 10C, 8000 Aarhus C (Denmark); Schrøder, Tenna Juul; Christensen, Søren [H. Lundbeck A/S, Ottiliavej 9, 2500 Valby (Denmark); Strandbygård, Dorthe [Aarhus University, Gustav Wieds Vej 10C, 8000 Aarhus C (Denmark); Pallesen, Lone Tjener [Aarhus University, Ole Worms Allé 3, 8000 Aarhus C (Denmark); García-Alai, Maria Marta [Aarhus University, Gustav Wieds Vej 10C, 8000 Aarhus C (Denmark); Lindberg, Samsa; Langgård, Morten; Eskildsen, Jørgen Calí; David, Laurent; Tagmose, Lena; Simonsen, Klaus Baek; Maltas, Philip James; Rønn, Lars Christian Biilmann; Jong, Inge E. M. de; Malik, Ibrahim John; Egebjerg, Jan; Karlsson, Jens-Jacob [H. Lundbeck A/S, Ottiliavej 9, 2500 Valby (Denmark); Uppalanchi, Srinivas; Sakumudi, Durga Rao; Eradi, Pradheep [GVK BioScience, Plot No. 28 A, IDA Nacharam, Hyderabad 500 076 (India); Watson, Steven P., E-mail: jla@mb.au.dk [H. Lundbeck A/S, Ottiliavej 9, 2500 Valby (Denmark); Thirup, Søren, E-mail: jla@mb.au.dk [Aarhus University, Gustav Wieds Vej 10C, 8000 Aarhus C (Denmark)

    2014-02-01

    The identification of the first small-molecule ligand of the neuronal receptor sortilin and structure determination of the receptor–ligand complex are reported. Sortilin is a type I membrane glycoprotein belonging to the vacuolar protein sorting 10 protein (Vps10p) family of sorting receptors and is most abundantly expressed in the central nervous system. Sortilin has emerged as a key player in the regulation of neuronal viability and has been implicated as a possible therapeutic target in a range of disorders. Here, the identification of AF40431, the first reported small-molecule ligand of sortilin, is reported. Crystals of the sortilin–AF40431 complex were obtained by co-crystallization and the structure of the complex was solved to 2.7 Å resolution. AF40431 is bound in the neurotensin-binding site of sortilin, with the leucine moiety of AF40431 mimicking the binding mode of the C-terminal leucine of neurotensin and the 4-methylumbelliferone moiety of AF40431 forming π-stacking with a phenylalanine.

  1. Identification of the first small-molecule ligand of the neuronal receptor sortilin and structure determination of the receptor–ligand complex

    International Nuclear Information System (INIS)

    Andersen, Jacob Lauwring; Schrøder, Tenna Juul; Christensen, Søren; Strandbygård, Dorthe; Pallesen, Lone Tjener; García-Alai, Maria Marta; Lindberg, Samsa; Langgård, Morten; Eskildsen, Jørgen Calí; David, Laurent; Tagmose, Lena; Simonsen, Klaus Baek; Maltas, Philip James; Rønn, Lars Christian Biilmann; Jong, Inge E. M. de; Malik, Ibrahim John; Egebjerg, Jan; Karlsson, Jens-Jacob; Uppalanchi, Srinivas; Sakumudi, Durga Rao; Eradi, Pradheep; Watson, Steven P.; Thirup, Søren

    2014-01-01

    The identification of the first small-molecule ligand of the neuronal receptor sortilin and structure determination of the receptor–ligand complex are reported. Sortilin is a type I membrane glycoprotein belonging to the vacuolar protein sorting 10 protein (Vps10p) family of sorting receptors and is most abundantly expressed in the central nervous system. Sortilin has emerged as a key player in the regulation of neuronal viability and has been implicated as a possible therapeutic target in a range of disorders. Here, the identification of AF40431, the first reported small-molecule ligand of sortilin, is reported. Crystals of the sortilin–AF40431 complex were obtained by co-crystallization and the structure of the complex was solved to 2.7 Å resolution. AF40431 is bound in the neurotensin-binding site of sortilin, with the leucine moiety of AF40431 mimicking the binding mode of the C-terminal leucine of neurotensin and the 4-methylumbelliferone moiety of AF40431 forming π-stacking with a phenylalanine

  2. Formulating accident occurrence as a survival process.

    Science.gov (United States)

    Chang, H L; Jovanis, P P

    1990-10-01

    A conceptual framework for accident occurrence is developed based on the principle of the driver as an information processor. The framework underlies the development of a modeling approach that is consistent with the definition of exposure to risk as a repeated trial. Survival theory is proposed as a statistical technique that is consistent with the conceptual structure and allows the exploration of a wide range of factors that contribute to highway operating risk. This survival model of accident occurrence is developed at a disaggregate level, allowing safety researchers to broaden the scope of studies which may be limited by the use of traditional aggregate approaches. An application of the approach to motor carrier safety is discussed as are potential applications to a variety of transportation industries. Lastly, a typology of highway safety research methodologies is developed to compare the properties of four safety methodologies: laboratory experiments, on-the-road studies, multidisciplinary accident investigations, and correlational studies. The survival theory formulation has a mathematical structure that is compatible with each safety methodology, so it may facilitate the integration of findings across methodologies.

  3. Identification and accurate quantification of structurally related peptide impurities in synthetic human C-peptide by liquid chromatography-high resolution mass spectrometry.

    Science.gov (United States)

    Li, Ming; Josephs, Ralf D; Daireaux, Adeline; Choteau, Tiphaine; Westwood, Steven; Wielgosz, Robert I; Li, Hongmei

    2018-06-04

    Peptides are an increasingly important group of biomarkers and pharmaceuticals. The accurate purity characterization of peptide calibrators is critical for the development of reference measurement systems for laboratory medicine and quality control of pharmaceuticals. The peptides used for these purposes are increasingly produced through peptide synthesis. Various approaches (for example mass balance, amino acid analysis, qNMR, and nitrogen determination) can be applied to accurately value assign the purity of peptide calibrators. However, all purity assessment approaches require a correction for structurally related peptide impurities in order to avoid biases. Liquid chromatography coupled to high resolution mass spectrometry (LC-hrMS) has become the key technique for the identification and accurate quantification of structurally related peptide impurities in intact peptide calibrator materials. In this study, LC-hrMS-based methods were developed and validated in-house for the identification and quantification of structurally related peptide impurities in a synthetic human C-peptide (hCP) material, which served as a study material for an international comparison looking at the competencies of laboratories to perform peptide purity mass fraction assignments. More than 65 impurities were identified, confirmed, and accurately quantified by using LC-hrMS. The total mass fraction of all structurally related peptide impurities in the hCP study material was estimated to be 83.3 mg/g with an associated expanded uncertainty of 3.0 mg/g (k = 2). The calibration hierarchy concept used for the quantification of individual impurities is described in detail. Graphical abstract ᅟ.

  4. Tandem Mass Spectrometry for Structural Identification of Sesquiterpene Alkaloids from the Stems of Dendrobium nobile Using LC-QToF.

    Science.gov (United States)

    Wang, Yan-Hong; Avula, Bharathi; Abe, Naohito; Wei, Feng; Wang, Mei; Ma, Shuang-Cheng; Ali, Zulfiqar; Elsohly, Mahmoud A; Khan, Ikhlas A

    2016-05-01

    Dendrobium nobile is one of the fundamental herbs in traditional Chinese medicine. Sesquiterpene alkaloids are the main active components in this plant. Due to weak ultraviolet absorption and low content in D. nobile, these sesquiterpene alkaloids have not been extensively studied using chromatographic methods. Herein, tandem mass spectrometry combined with liquid chromatography separation provides a tool for the identification and characterization of the alkaloids from D. nobile. A total of nine sesquiterpene alkaloids were characterized by ultrahigh-performance liquid chromatography tandem mass spectrometry. These alkaloids can be classified into two subgroups that are represented by dendrobine and nobilonine. Tandem mass spectrometric studies revealed the fragmentation pathways of these two subgroup alkaloids that were used for the identification and characterization of other alkaloids in D. nobile. Characterization of these alkaloids using accurate mass and diagnostic fragments provided a reliable methodology for the analysis of D. nobile by ultrahigh-performance liquid chromatography tandem mass spectrometry. The limit of detection was defined as the signal-to-noise ratio equal to 3 : 1. Limits of detection of dendrobine and nobilonine were less than 30 ng/mL. The developed method was applied for the analysis of various Dendrobium species and related dietary supplements. Alkaloids were identified from D. nobile, but not detected from commercial samples including 13 other Dendrobium species and the 7 dietary supplements. Georg Thieme Verlag KG Stuttgart · New York.

  5. Packaging and transportation occurrence reporting

    International Nuclear Information System (INIS)

    Needels, T.S.

    1996-01-01

    The US Department of Energy (DOE) Order 231.1 calls for the maintenance of a database for all unclassified occurrence reports (ORs). ORS provide DOE with notice of incidents and accidents that endanger the public, workers, or DOE facility operations. To fulfill this policy, the DOE Occurrence Reporting and Processing System (ORPS) was established to require DOE facilities to report and process information concerning such events. The Oak Ridge National Laboratory (ORNL) provides DOE with data and analysis of occurrence related to packaging and transportation (P and T) safety. This program produces annual reports, lessons learned bulletins, and information for the packaging and transportation home page on the Internet. The analysis and reports provided can be used as a tool for oversight and a means for DOE sites to be proactive and anticipate problems through shared knowledge and lessons learned. To illustrate, some observable trends based on 3 years of the program are given. In summary, this program shows potential problem areas that need correcting, and possible breakdowns of safety

  6. Positive identification by a skull with multiple epigenetic traits and abnormal structure of the neurocranium, viscerocranium, and the skeleton.

    Science.gov (United States)

    Kuharić, Josip; Kovacic, Natasa; Marusic, Petar; Marusic, Ana; Petrovecki, Vedrana

    2011-05-01

    Wormian bones are small ossicles appearing within the cranial sutures in more than 40% of skulls, most commonly at the lambdoid suture and pterion. During the skeletal analysis of an unidentified male war victim, we observed multiple wormian bones and a patent metopic suture. Additionally, the right elbow was deformed, probably as a consequence of an old trauma. The skull was analyzed by cranial measurements and computerized tomography, revealing the presence of cranial deformities including hyperbrachicrania, localized reduction in hemispheral widths, increased cranial capacity, and sclerosis of the viscerocranium. Besides unique anatomical features and their anthropological value, such skeletal abnormalities also have a forensic value as the evidence to support the final identification of the victim. © 2011 American Academy of Forensic Sciences.

  7. The Expanded FindCore Method for Identification of a Core Atom Set for Assessment of Protein Structure Prediction

    Science.gov (United States)

    Snyder, David A.; Grullon, Jennifer; Huang, Yuanpeng J.; Tejero, Roberto; Montelione, Gaetano T.

    2014-01-01

    Maximizing the scientific impact of NMR-based structure determination requires robust and statistically sound methods for assessing the precision of NMR-derived structures. In particular, a method to define a core atom set for calculating superimpositions and validating structure predictions is critical to the use of NMR-derived structures as targets in the CASP competition. FindCore (D.A. Snyder and G.T. Montelione PROTEINS 2005;59:673–686) is a superimposition independent method for identifying a core atom set, and partitioning that set into domains. However, as FindCore optimizes superimposition by sensitively excluding not-well-defined atoms, the FindCore core may not comprise all atoms suitable for use in certain applications of NMR structures, including the CASP assessment process. Adapting the FindCore approach to assess predicted models against experimental NMR structures in CASP10 required modification of the FindCore method. This paper describes conventions and a standard protocol to calculate an “Expanded FindCore” atom set suitable for validation and application in biological and biophysical contexts. A key application of the Expanded FindCore method is to identify a core set of atoms in the experimental NMR structure for which it makes sense to validate predicted protein structure models. We demonstrate the application of this Expanded FindCore method in characterizing well-defined regions of 18 NMR-derived CASP10 target structures. The Expanded FindCore protocol defines “expanded core atom sets” that match an expert’s intuition of which parts of the structure are sufficiently well-defined to use in assessing CASP model predictions. We also illustrate the impact of this analysis on the CASP GDT assessment scores. PMID:24327305

  8. Inverse problem studies of biochemical systems with structure identification of S-systems by embedding training functions in a genetic algorithm.

    Science.gov (United States)

    Sarode, Ketan Dinkar; Kumar, V Ravi; Kulkarni, B D

    2016-05-01

    An efficient inverse problem approach for parameter estimation, state and structure identification from dynamic data by embedding training functions in a genetic algorithm methodology (ETFGA) is proposed for nonlinear dynamical biosystems using S-system canonical models. Use of multiple shooting and decomposition approach as training functions has been shown for handling of noisy datasets and computational efficiency in studying the inverse problem. The advantages of the methodology are brought out systematically by studying it for three biochemical model systems of interest. By studying a small-scale gene regulatory system described by a S-system model, the first example demonstrates the use of ETFGA for the multifold aims of the inverse problem. The estimation of a large number of parameters with simultaneous state and network identification is shown by training a generalized S-system canonical model with noisy datasets. The results of this study bring out the superior performance of ETFGA on comparison with other metaheuristic approaches. The second example studies the regulation of cAMP oscillations in Dictyostelium cells now assuming limited availability of noisy data. Here, flexibility of the approach to incorporate partial system information in the identification process is shown and its effect on accuracy and predictive ability of the estimated model are studied. The third example studies the phenomenological toy model of the regulation of circadian oscillations in Drosophila that follows rate laws different from S-system power-law. For the limited noisy data, using a priori information about properties of the system, we could estimate an alternate S-system model that showed robust oscillatory behavior with predictive abilities. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Identification of New Natural DNA G-Quadruplex Binders Selected by a Structure-Based Virtual Screening Approach

    Directory of Open Access Journals (Sweden)

    Stefano Alcaro

    2013-09-01

    Full Text Available The G-quadruplex DNA structures are mainly present at the terminal portion of telomeres and can be stabilized by ligands able to recognize them in a specific manner. The recognition process is usually related to the inhibition of the enzyme telomerase indirectly involved and over-expressed in a high percentage of human tumors. There are several ligands, characterized by different chemical structures, already reported in the literature for their ability to bind and stabilize the G-quadruplex structures. Using the structural and biological information available on these structures; we performed a high throughput in silico screening of commercially natural compounds databases by means of a structure-based approach followed by docking experiments against the human telomeric sequence d[AG3(T2AG33]. We identified 12 best hits characterized by different chemical scaffolds and conformational and physicochemical properties. All of them were associated to an improved theoretical binding affinity with respect to that of known selective G-binders. Among these hits there is a chalcone derivative; structurally very similar to the polyphenol butein; known to remarkably inhibit the telomerase activity.

  10. Subsurface structure identification uses derivative analyses of the magnetic data in Candi Umbul-Telomoyo geothermal prospect area

    Science.gov (United States)

    Septyasari, U.; Niasari, S. W.; Maghfira, P. D.

    2018-04-01

    Telomoyo geothermal prospect area is located in Central Java, Indonesia. One of the manifestations around Telomoyo is a warm spring, called Candi Umbul. The hydrothermal fluids from the manifestation could be from the subsurface flowing up through geological structures. The previous research about 2D magnetic modeling in Candi Umbul showed that there was a normal fault with strike/dip N60°E/45° respectively. This research aims to know the distance boundary and the kind of the geological structure in the study area. We also compared the geological structure direction based on the geologic map and the derivative maps. We used derivative analyses of the magnetic data, i.e. First Horizontal Derivative (FHD) which is the rate of change of the horizontal gradient in the horizontal direction. FHD indicates the boundaries of the geological structure. We also used Second Vertical Derivative (SVD) which is the rate of change of the vertical gradient in the vertical direction. SVD can reveal normal fault or thrust fault. The FHD and SVD maps show that the geological structure boundary has the same direction with the north west-south east geological structure. The geological structure boundary is in 486 m of the local distance. Our result confirms that there is a normal fault in the study area.

  11. Identification of an Equivalent Linear Model for a Non-Linear Time-Variant RC-Structure

    DEFF Research Database (Denmark)

    Kirkegaard, Poul Henning; Andersen, P.; Brincker, Rune

    are investigated and compared with ARMAX models used on a running window. The techniques are evaluated using simulated data generated by the non-linear finite element program SARCOF modeling a 10-storey 3-bay concrete structure subjected to amplitude modulated Gaussian white noise filtered through a Kanai......This paper considers estimation of the maximum softening for a RC-structure subjected to earthquake excitation. The so-called Maximum Softening damage indicator relates the global damage state of the RC-structure to the relative decrease of the fundamental eigenfrequency in an equivalent linear...

  12. An Improved Method of Parameter Identification and Damage Detection in Beam Structures under Flexural Vibration Using Wavelet Multi-Resolution Analysis

    Directory of Open Access Journals (Sweden)

    Seyed Alireza Ravanfar

    2015-09-01

    Full Text Available This paper reports on a two-step approach for optimally determining the location and severity of damage in beam structures under flexural vibration. The first step focuses on damage location detection. This is done by defining the damage index called relative wavelet packet entropy (RWPE. The damage severities of the model in terms of loss of stiffness are assessed in the second step using the inverse solution of equations of motion of a structural system in the wavelet domain. For this purpose, the connection coefficient of the scaling function to convert the equations of motion in the time domain into the wavelet domain is applied. Subsequently, the dominant components based on the relative energies of the wavelet packet transform (WPT components of the acceleration responses are defined. To obtain the best estimation of the stiffness parameters of the model, the least squares error minimization is used iteratively over the dominant components. Then, the severity of the damage is evaluated by comparing the stiffness parameters of the identified model before and after the occurrence of damage. The numerical and experimental results demonstrate that the proposed method is robust and effective for the determination of damage location and accurate estimation of the loss in stiffness due to damage.

  13. Compressive power spectrum sensing for vibration-based output-only system identification of structural systems in the presence of noise

    Science.gov (United States)

    Tau Siesakul, Bamrung; Gkoktsi, Kyriaki; Giaralis, Agathoklis

    2015-05-01

    Motivated by the need to reduce monetary and energy consumption costs of wireless sensor networks in undertaking output-only/operational modal analysis of engineering structures, this paper considers a multi-coset analog-toinformation converter for structural system identification from acceleration response signals of white noise excited linear damped structures sampled at sub-Nyquist rates. The underlying natural frequencies, peak gains in the frequency domain, and critical damping ratios of the vibrating structures are estimated directly from the sub-Nyquist measurements and, therefore, the computationally demanding signal reconstruction step is by-passed. This is accomplished by first employing a power spectrum blind sampling (PSBS) technique for multi-band wide sense stationary stochastic processes in conjunction with deterministic non-uniform multi-coset sampling patterns derived from solving a weighted least square optimization problem. Next, modal properties are derived by the standard frequency domain peak picking algorithm. Special attention is focused on assessing the potential of the adopted PSBS technique, which poses no sparsity requirements to the sensed signals, to derive accurate estimates of modal structural system properties from noisy sub- Nyquist measurements. To this aim, sub-Nyquist sampled acceleration response signals corrupted by various levels of additive white noise pertaining to a benchmark space truss structure with closely spaced natural frequencies are obtained within an efficient Monte Carlo simulation-based framework. Accurate estimates of natural frequencies and reasonable estimates of local peak spectral ordinates and critical damping ratios are derived from measurements sampled at about 70% below the Nyquist rate and for SNR as low as 0db demonstrating that the adopted approach enjoys noise immunity.

  14. Colorado quartz: occurrence and discovery

    Science.gov (United States)

    Kile, D.E.; Modreski, P.J.; Kile, D.L.

    1991-01-01

    The many varieties and associations of quartz found throughout the state rank it as one of the premier worldwide localities for that species. This paper briefly outlines the historical importance of the mineral, the mining history and the geological setting before discussing the varieties of quartz present, its crystallography and the geological enviroments in which it is found. The latter include volcanic rocks and near surface igneous rocks; pegmatites; metamorphic and plutonic rocks; hydrothermal veins; skarns and sedimentary deposits. Details of the localities and mode of occurrence of smoky quartz, amethyst, milky quartz, rock crystal, rose quartz, citrine, agate and jasper are then given. -S.J.Stone

  15. Occurrence reporting and processing of operations information

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-07-21

    DOE O 232.1A, Occurrence Reporting and Processing of Operations Information, and 10 CFR 830.350, Occurrence Reporting and Processing of Operations Information (when it becomes effective), along with this manual, set forth occurrence reporting requirements for Department of Energy (DOE) Departmental Elements and contractors responsible for the management and operation of DOE-owned and -leased facilities. These requirements include categorization of occurrences related to safety, security, environment, health, or operations (``Reportable Occurrences``); DOE notification of these occurrences; and the development and submission of documented follow-up reports. This Manual provides detailed information for categorizing and reporting occurrences at DOE facilities. Information gathered by the Occurrence Reporting and processing System is used for analysis of the Department`s performance in environmental protection, safeguards and security, and safety and health of its workers and the public. This information is also used to develop lessons learned and document events that significantly impact DOE operations.

  16. Occurrence reporting and processing of operations information

    International Nuclear Information System (INIS)

    1997-01-01

    DOE O 232.1A, Occurrence Reporting and Processing of Operations Information, and 10 CFR 830.350, Occurrence Reporting and Processing of Operations Information (when it becomes effective), along with this manual, set forth occurrence reporting requirements for Department of Energy (DOE) Departmental Elements and contractors responsible for the management and operation of DOE-owned and -leased facilities. These requirements include categorization of occurrences related to safety, security, environment, health, or operations (''Reportable Occurrences''); DOE notification of these occurrences; and the development and submission of documented follow-up reports. This Manual provides detailed information for categorizing and reporting occurrences at DOE facilities. Information gathered by the Occurrence Reporting and processing System is used for analysis of the Department's performance in environmental protection, safeguards and security, and safety and health of its workers and the public. This information is also used to develop lessons learned and document events that significantly impact DOE operations

  17. Characterization of the linkage disequilibrium structure and identification of tagging-SNPs in five DNA repair genes

    International Nuclear Information System (INIS)

    Allen-Brady, Kristina; Camp, Nicola J

    2005-01-01

    Characterization of the linkage disequilibrium (LD) structure of candidate genes is the basis for an effective association study of complex diseases such as cancer. In this study, we report the LD and haplotype architecture and tagging-single nucleotide polymorphisms (tSNPs) for five DNA repair genes: ATM, MRE11A, XRCC4, NBS1 and RAD50. The genes ATM, MRE11A, and XRCC4 were characterized using a panel of 94 unrelated female subjects (47 breast cancer cases, 47 controls) obtained from high-risk breast cancer families. A similar LD structure and tSNP analysis was performed for NBS1 and RAD50, using publicly available genotyping data. We studied a total of 61 SNPs at an average marker density of 10 kb. Using a matrix decomposition algorithm, based on principal component analysis, we captured >90% of the intragenetic variation for each gene. Our results revealed that three of the five genes did not conform to a haplotype block structure (MRE11A, RAD50 and XRCC4). Instead, the data fit a more flexible LD group paradigm, where SNPs in high LD are not required to be contiguous. Traditional haplotype blocks assume recombination is the only dynamic at work. For ATM, MRE11A and XRCC4 we repeated the analysis in cases and controls separately to determine whether LD structure was consistent across breast cancer cases and controls. No substantial difference in LD structures was found. This study suggests that appropriate SNP selection for an association study involving candidate genes should allow for both mutation and recombination, which shape the population-level genomic structure. Furthermore, LD structure characterization in either breast cancer cases or controls appears to be sufficient for future cancer studies utilizing these genes

  18. MetalS(3), a database-mining tool for the identification of structurally similar metal sites.

    Science.gov (United States)

    Valasatava, Yana; Rosato, Antonio; Cavallaro, Gabriele; Andreini, Claudia

    2014-08-01

    We have developed a database search tool to identify metal sites having structural similarity to a query metal site structure within the MetalPDB database of minimal functional sites (MFSs) contained in metal-binding biological macromolecules. MFSs describe the local environment around the metal(s) independently of the larger context of the macromolecular structure. Such a local environment has a determinant role in tuning the chemical reactivity of the metal, ultimately contributing to the functional properties of the whole system. The database search tool, which we called MetalS(3) (Metal Sites Similarity Search), can be accessed through a Web interface at http://metalweb.cerm.unifi.it/tools/metals3/ . MetalS(3) uses a suitably adapted version of an algorithm that we previously developed to systematically compare the structure of the query metal site with each MFS in MetalPDB. For each MFS, the best superposition is kept. All these superpositions are then ranked according to the MetalS(3) scoring function and are presented to the user in tabular form. The user can interact with the output Web page to visualize the structural alignment or the sequence alignment derived from it. Options to filter the results are available. Test calculations show that the MetalS(3) output correlates well with expectations from protein homology considerations. Furthermore, we describe some usage scenarios that highlight the usefulness of MetalS(3) to obtain mechanistic and functional hints regardless of homology.

  19. BioJava-ModFinder: identification of protein modifications in 3D structures from the Protein Data Bank.

    Science.gov (United States)

    Gao, Jianjiong; Prlic, Andreas; Bi, Chunxiao; Bluhm, Wolfgang F; Dimitropoulos, Dimitris; Xu, Dong; Bourne, Philip E; Rose, Peter W

    2017-07-01

    We developed a new software tool, BioJava-ModFinder, for identifying protein modifications observed in 3D structures archived in the Protein Data Bank (PDB). Information on more than 400 types of protein modifications were collected and curated from annotations in PDB, RESID, and PSI-MOD. We divided these modifications into three categories: modified residues, attachment modifications, and cross-links. We have developed a systematic method to identify these modifications in 3D protein structures. We have integrated this package with the RCSB PDB web application and added protein modification annotations to the sequence diagram and structure display. By scanning all 3D structures in the PDB using BioJava-ModFinder, we identified more than 30 000 structures with protein modifications, which can be searched, browsed, and visualized on the RCSB PDB website. BioJava-ModFinder is available as open source (LGPL license) at ( https://github.com/biojava/biojava/tree/master/biojava-modfinder ). The RCSB PDB can be accessed at http://www.rcsb.org . pwrose@ucsd.edu. © The Author 2017. Published by Oxford University Press.

  20. Shannon Entropy-Based Wavelet Transform Method for Autonomous Coherent Structure Identification in Fluid Flow Field Data

    Directory of Open Access Journals (Sweden)

    Kartik V. Bulusu

    2015-09-01

    Full Text Available The coherent secondary flow structures (i.e., swirling motions in a curved artery model possess a variety of spatio-temporal morphologies and can be encoded over an infinitely-wide range of wavelet scales. Wavelet analysis was applied to the following vorticity fields: (i a numerically-generated system of Oseen-type vortices for which the theoretical solution is known, used for bench marking and evaluation of the technique; and (ii experimental two-dimensional, particle image velocimetry data. The mother wavelet, a two-dimensional Ricker wavelet, can be dilated to infinitely large or infinitesimally small scales. We approached the problem of coherent structure detection by means of continuous wavelet transform (CWT and decomposition (or Shannon entropy. The main conclusion of this study is that the encoding of coherent secondary flow structures can be achieved by an optimal number of binary digits (or bits corresponding to an optimal wavelet scale. The optimal wavelet-scale search was driven by a decomposition entropy-based algorithmic approach and led to a threshold-free coherent structure detection method. The method presented in this paper was successfully utilized in the detection of secondary flow structures in three clinically-relevant blood flow scenarios involving the curved artery model under a carotid artery-inspired, pulsatile inflow condition. These scenarios were: (i a clean curved artery; (ii stent-implanted curved artery; and (iii an idealized Type IV stent fracture within the curved artery.

  1. Identification of the basic structure of a glycolipid from Selenomonas ruminantium as β-glucosaminyl-1,6-glucosamine

    International Nuclear Information System (INIS)

    Kamio, Yoshiyuki; Kim, Kyo-Chang; Takahashi, Hajime

    1972-01-01

    Lipid materials extracted by chloroform-methanol from solvent and acid treated cells of Selenomonas ruminantium grown with valerate - 14 C were analyzed by thin-layer chromatography. At least 12 radioactive lipid materials were present in the extract. The major compound, designated as spot A, carried approximately 70% of radioactivity of this fraction. The spot A compound was purified by column and thin-layer chromatography and its chemical structure was studied. The basic structural unit of this material was tentatively identified as β-glucosaminyl-1, 6-glucosamine with O-acyl and amide linked fatty acids. (author)

  2. Identification of locally available structural material as co-substrate for organic waste composting in Tamil Nadu, India.

    Science.gov (United States)

    Springer, C; Heldt, N

    2016-06-01

    Owing to the lack in structural strength while composting certain kinds of organic wastes, 11 co-substrates were tested that are generally locally available in rural areas of northern Tamil Nadu, India. In addition to the classical composting parameters such as carbon/nitrogen ratio, moisture content, dry matter and organic dry matter, a compression test was conducted to evaluate the structural strength and the suitability as bulking agent for composting processes. Additionally, with respect to the climatic conditions in India, the water holding capacity was also evaluated. © The Author(s) 2016.

  3. Occurrence and bioremediation of anthracene in the environment ...

    African Journals Online (AJOL)

    Occurrence of PAH in the environment has been a concern of many environmentalist for its obstinac, toxicity and harm that it may impose. Anthracene is a common low molecular weight PAH that is often used as a model PAH in bioremediation study due to its structure that is also found in high molecular weight PAH.

  4. Occurrence, biological activity and synthesis of drimane sesquiterpenoids

    NARCIS (Netherlands)

    Jansen, B.J.M.; Groot, de Æ.

    2004-01-01

    In this review the names, structures and occurrence of all new drimanes and rearranged drimanes, which have been published between January 1990 and January 2003 have been collected. Subjects that have been treated are biosynthesis, analysis, biological activities, with special attention to cytotoxic

  5. Identification of plant configurations maximizing radiation capture in relay strip cotton using a functional-structural plant model

    NARCIS (Netherlands)

    Mao, Lili; Zhang, Lizhen; Evers, J.B.; Henke, M.; Werf, van der W.; Liu, Shaodong; Zhang, Siping; Zhao, Xinhua; Wang, Baomin; Li, Zhaohu

    2016-01-01

    One of the key decisions in crop production is the choice of row distance and plant density. The choice of these planting pattern parameters is especially challenging in heterogeneous systems, such as systems containing alternating strips. Here we use functional-structural plant modelling to

  6. Identification of a major non-structural protein in the nuclei of Rift Valley fever virus-infected cells.

    Science.gov (United States)

    Struthers, J K; Swanepoel, R

    1982-06-01

    A non-structural protein of mol. wt. 34 X 10(3) was demonstrated in the nuclei of Rift Valley fever virus-infected Vero cells by SDS-polyacrylamide gel electro-phoresis. The protein appears to correspond to the virus-induced antigen demonstrated by indirect immunofluorescence in intranuclear inclusions.

  7. Identification of Five Structurally Unrelated Quorum-Sensing Inhibitors of Pseudomonas aeruginosa from a Natural-Derivative Database

    DEFF Research Database (Denmark)

    Tan, Sean Yang-Yi; Chua, Song-Lin; Chen, Yicai

    2013-01-01

    QSI candidates. Three-dimensional structures of 3,040 natural compounds and their derivatives were obtained, after which molecular docking was performed using the QS receptor LasR as a target. Based on docking scores and molecular masses, 22 compounds were purchased to determine their efficacies...

  8. Identification of novel malarial cysteine protease inhibitors using structure-based virtual screening of a focused cysteine protease inhibitor library.

    Science.gov (United States)

    Shah, Falgun; Mukherjee, Prasenjit; Gut, Jiri; Legac, Jennifer; Rosenthal, Philip J; Tekwani, Babu L; Avery, Mitchell A

    2011-04-25

    Malaria, in particular that caused by Plasmodium falciparum , is prevalent across the tropics, and its medicinal control is limited by widespread drug resistance. Cysteine proteases of P. falciparum , falcipain-2 (FP-2) and falcipain-3 (FP-3), are major hemoglobinases, validated as potential antimalarial drug targets. Structure-based virtual screening of a focused cysteine protease inhibitor library built with soft rather than hard electrophiles was performed against an X-ray crystal structure of FP-2 using the Glide docking program. An enrichment study was performed to select a suitable scoring function and to retrieve potential candidates against FP-2 from a large chemical database. Biological evaluation of 50 selected compounds identified 21 diverse nonpeptidic inhibitors of FP-2 with a hit rate of 42%. Atomic Fukui indices were used to predict the most electrophilic center and its electrophilicity in the identified hits. Comparison of predicted electrophilicity of electrophiles in identified hits with those in known irreversible inhibitors suggested the soft-nature of electrophiles in the selected target compounds. The present study highlights the importance of focused libraries and enrichment studies in structure-based virtual screening. In addition, few compounds were screened against homologous human cysteine proteases for selectivity analysis. Further evaluation of structure-activity relationships around these nonpeptidic scaffolds could help in the development of selective leads for antimalarial chemotherapy.

  9. Metals and ions in protein structures - from essential to marginal questions in identification of ions in enzymes and receptors

    Czech Academy of Sciences Publication Activity Database

    Dohnálek, Jan

    2013-01-01

    Roč. 20, č. 1 (2013), s. 14-15 ISSN 1211-5894. [Discussions in Structural Molecular Biology /11./. 14.03.2013-16.03.2013, Nové Hrady] R&D Projects: GA ČR GA310/09/1407 Institutional support: RVO:61389013 Keywords : protein * X-ray diffraction * metal Subject RIV: EE - Microbiology, Virology

  10. Identification and structural characterization of serobactins, a suite of lipopeptide siderophores produced by the grass endophyte Herbaspirillum seropedicae.

    Science.gov (United States)

    Rosconi, Federico; Davyt, Danilo; Martínez, Verónica; Martínez, Marcela; Abin-Carriquiry, Juan Andrés; Zane, Hannah; Butler, Alison; de Souza, Emanuel M; Fabiano, Elena

    2013-03-01

    Herbaspirillum seropedicae Z67 is a diazotrophic endophyte able to colonize the interior of many economically relevant crops such as rice, wheat, corn and sorghum. Structures of siderophores produced by bacterial endophytes have not yet been elucidated. The aim of this work was to identify and characterize the siderophores produced by this bacterium. In a screening for mutants unable to produce siderophores we found a mutant that had a transposon insertion in a non-ribosomal peptide synthase (NRPS) gene coding for a putative siderophore biosynthetic enzyme. The chemical structure of the siderophore was predicted using computational genomic tools. The predicted structure was confirmed by chemical analysis. We found that siderophores produced by H. seropedicae Z67 are a suite of amphiphilic lipopeptides, named serobactin A, B and C, which vary by the length of the fatty acid chain. We also demonstrated the biological activity of serobactins as nutritional iron sources for H. seropedicae. These are the first structurally described siderophores produced by endophytic bacteria. © 2012 Society for Applied Microbiology and Blackwell Publishing Ltd.

  11. Identification of Quaternary Structure and Functional Domains of the CI Repressor from Bacteriophage TP901-1

    DEFF Research Database (Denmark)

    Pedersen, Margit; Lo Leggio, Leila; Grossmann, J. Günter

    2008-01-01

    is involved in the interaction with host proteins. By using small-angle X-ray scattering, we show for the first time the overall solution structure of a full-length wild-type bacteriophage repressor at low resolution revealing that the TP901-1 repressor forms a flat oligomer, most probably a trimer of dimers....

  12. Computational identification and phylogenetic analysis of the oil-body structural proteins, oleosin and caleosin, in castor bean and flax.

    Science.gov (United States)

    Hyun, Tae Kyung; Kumar, Dhinesh; Cho, Young-Yeol; Hyun, Hae-Nam; Kim, Ju-Sung

    2013-02-25

    Oil bodies (OBs) are the intracellular particles derived from oilseeds. These OBs store lipids as a carbon resource, and have been exploited for a variety of industrial applications including biofuels. Oleosin and caleosin are the common OB structural proteins which are enabling biotechnological enhancement of oil content and OB-based pharmaceutical formations via stabilizing OBs. Although the draft whole genome sequence information for Ricinus communis L. (castor bean) and Linum usitatissimum L. (flax), important oil seed plants, is available in public database, OB-structural proteins in these plants are poorly indentified. Therefore, in this study, we performed a comprehensive bioinformatic analysis including analysis of the genome sequence, conserved domains and phylogenetic relationships to identify OB structural proteins in castor bean and flax genomes. Using comprehensive analysis, we have identified 6 and 15 OB-structural proteins from castor bean and flax, respectively. A complete overview of this gene family in castor bean and flax is presented, including the gene structures, phylogeny and conserved motifs, resulting in the presence of central hydrophobic regions with proline knot motif, providing an evolutionary proof that this central hydrophobic region had evolved from duplications in the primitive eukaryotes. In addition, expression analysis of L-oleosin and caleosin genes using quantitative real-time PCR demonstrated that seed contained their maximum expression, except that RcCLO-1 expressed maximum in cotyledon. Thus, our comparative genomics analysis of oleosin and caleosin genes and their putatively encoded proteins in two non-model plant species provides insights into the prospective usage of gene resources for improving OB-stability. Copyright © 2012 Elsevier B.V. All rights reserved.

  13. Lead identification and structure-activity relationships of heteroarylpyrazole arylsulfonamides as allosteric CC-chemokine receptor 4 (CCR4) antagonists.

    Science.gov (United States)

    Miah, Afjal H; Copley, Royston C B; O'Flynn, Daniel; Percy, Jonathan M; Procopiou, Panayiotis A

    2014-03-21

    A knowledge-based library of aryl 2,3-dichlorophenylsulfonamides was synthesised and screened as human CCR4 antagonists, in order to identify a suitable hit for the start of a lead-optimisation programme. X-ray diffraction studies were used to identify the pyrazole ring as a moiety that could bring about intramolecular hydrogen bonding with the sulfonamide NH and provide a clip or orthogonal conformation that was believed to be the preferred active conformation. Replacement of the core phenyl ring with a pyridine, and replacement of the 2,3-dichlorobenzenesulfonamide with 5-chlorothiophenesulfonamide provided compound 33 which has excellent physicochemical properties and represents a good starting point for a lead optimisation programme. Electronic structure calculations indicated that the preference for the clip or orthogonal conformation found in the small molecule crystal structures of 7 and 14 was in agreement with the order of potency in the biological assay.

  14. Identification and first insights into the structure and biosynthesis of chitin from the freshwater sponge Spongilla lacustris.

    Science.gov (United States)

    Ehrlich, Hermann; Kaluzhnaya, Oksana V; Brunner, Eike; Tsurkan, Mikhail V; Ereskovsky, Alexander; Ilan, Micha; Tabachnick, Konstantin R; Bazhenov, Vasilii V; Paasch, Silvia; Kammer, Martin; Born, René; Stelling, Allison; Galli, Roberta; Belikov, Sergei; Petrova, Olga V; Sivkov, Victor V; Vyalikh, Denis; Hunoldt, Sebastian; Wörheide, Gert

    2013-09-01

    This work demonstrates that chitin is an important structural component within the skeletal fibers of the freshwater sponge Spongilla lacustris. Using a variety of analytical techniques ((13)C solid state NMR, FT-IR, Raman, NEXAFS, ESI-MS, Morgan-Elson assay and Calcofluor White Staining); we show that this sponge chitin is much closer to α-chitin, known to be present in other animals, than to β-chitin. Genetic analysis confirmed the presence of chitin synthases, which are described for the first time in a sponge. The presence of chitin in both marine (demosponges and hexactinellids) and freshwater sponges indicates that this important structural biopolymer was already present in their common ancestor. Copyright © 2013 Elsevier Inc. All rights reserved.

  15. Charcoal records reveal past occurrences of disturbances in the forests of the Kisangani region, Democratic Republic of the Congo

    Science.gov (United States)

    Tshibamba Mukendi, John; Hubau, Wannes; Ntahobavuka, Honorine; Boyemba Bosela, Faustin; De Cannière, Charles; Beeckman, Hans

    2014-05-01

    Past disturbances have modified local density, structure and floristic composition of Central African rainforests. As such, these perturbations represent a driving force for forest dynamics and they were presumably at the origin of present-day forest mosaics. One of the most prominent disturbances within the forest is fire, leaving behind charcoal as a witness of past forest dynamics. Quantification and identification of ancient charcoal fragments found in soil layers (= pedoanthracology) allows a detailed reconstruction of forest history, including the possible occurrence of past perturbations. The primary objective of this study is to present palaeoenvironmental evidence for the existence of past disturbances in the forests of the Kisangani region (Democratic Republic of the Congo) using a pedoanthracological approach. We quantified and identified charcoal fragments from pedoanthracological excavations in the Yangambi, Yoko, Masako and Kole forest regions. Charcoal sampling was conducted in pit intervals of 10 cm, whereby pottery fragments were also registered and quantified. Floristic identifications were conducted using former protocols based on wood anatomy, which is largely preserved after charcoalification. 14 excavations were conducted and charcoal was found in most pit intervals. Specifically, 52 out of 56 sampled intervals from the Yangambi forest contained charcoal, along with 47 pit intervals from the Yoko forest reserve, 34 pit intervals from the Masako forest and 16 from the Kole forest. Highest specific anthracomasses were recorded in Yoko (167 mg charcoal per kg soil), followed by Yangambi (133 mg/kg), Masako (71,89 mg/kg) and finally Kole (42,4 mg/kg). Charcoal identifications point at a manifest presence of the family of Fabaceae (Caesalpinioideae). This family is characteristic for the tropical humid rainforest. The presence of charcoal fragments from these taxa, associated with pottery sherds on different depths within the profiles, suggests

  16. Prediction of Global Damage and Reliability Based Upon Sequential Identification and Updating of RC Structures Subject to Earthquakes

    DEFF Research Database (Denmark)

    Nielsen, Søren R.K.; Skjærbæk, P. S.; Köylüoglu, H. U.

    The paper deals with the prediction of global damage and future structural reliability with special emphasis on sensitivity, bias and uncertainty of these predictions dependent on the statistically equivalent realizations of the future earthquake. The predictions are based on a modified Clough......-Johnston single-degree-of-freedom (SDOF) oscillator with three parameters which are calibrated to fit the displacement response and the damage development in the past earthquake....

  17. Cluster Analysis of Time-Dependent Crystallographic Data: Direct Identification of Time-Independent Structural Intermediates

    Science.gov (United States)

    Kostov, Konstantin S.; Moffat, Keith

    2011-01-01

    The initial output of a time-resolved macromolecular crystallography experiment is a time-dependent series of difference electron density maps that displays the time-dependent changes in underlying structure as a reaction progresses. The goal is to interpret such data in terms of a small number of crystallographically refinable, time-independent structures, each associated with a reaction intermediate; to establish the pathways and rate coefficients by which these intermediates interconvert; and thereby to elucidate a chemical kinetic mechanism. One strategy toward achieving this goal is to use cluster analysis, a statistical method that groups objects based on their similarity. If the difference electron density at a particular voxel in the time-dependent difference electron density (TDED) maps is sensitive to the presence of one and only one intermediate, then its temporal evolution will exactly parallel the concentration profile of that intermediate with time. The rationale is therefore to cluster voxels with respect to the shapes of their TDEDs, so that each group or cluster of voxels corresponds to one structural intermediate. Clusters of voxels whose T